As a bioengineer and a translational medicine scientist, my career goal is to deploy advanced technologies to solve real clinical needs. I graduated with both BSc and MSc in Biomedical Engineering at the Politecnico di Milano, which provided me an excellent background in medical imaging, signal processing, and computer-aided radiology and surgery. In 2017, I obtained my Ph.D. in Integrative Biomedical Research at the University of Milan. During my Ph.D., I attended a 6-month fellowship at the Imaging and pathology department of the KU Leuven University.
After that, I worked two years as a postdoctoral researcher at the IRCCS Policlinico San Donato and one year at the Politecnico di Milano. Since then, my main research focus has been medical image processing, with a major focus on the application of machine learning techniques for cardiovascular and cerebrovascular imaging applications. Currently, I'm a Postdoctoral Research Fellow at Stanford University School of Medicine as part of the cardiovascular imaging research group. My research project focus on the application of deep learning and deep reinforcement learning to improve the diagnosis and treatment planning in patients with aortic dissection.
Boards, Advisory Committees, Professional Organizations
Editorial Board Member, European Radiology (2021 - Present)
Trainee Editorial Board Member, Radiology: Artificial Intelligence (2020 - Present)
Section Editor - Artificial Intelligence and Machine Learning, European Journal of Radiology (2019 - Present)
Editorial Board Member, European Radiology Experimental (2019 - Present)
Counselor, International Society of Magnetic Resonance in Medicine - Italian Chapter (2018 - Present)
Doctor of Philosophy, Universita Degli Studi Di Milano (2017)
Master of Science, Politecnico Di Milano (2013)
Bachelor of Science, Politecnico Di Milano (2010)
Dominik Fleischmann, Postdoctoral Faculty Sponsor
Current Research and Scholarly Interests
Bridging healthcare open challenges and technological solutions, with focus on diagnostics. My main research focus is the application of deep learning technique in medical imaging for personalized diagnosis and treatment planning in patients with aortic dissection
Emerging methods for the characterization of ischemic heart disease: ultrafast Doppler angiography, micro-CT, photon-counting CT, novel MRI and PET techniques, and artificial intelligence.
European radiology experimental
2021; 5 (1): 12
After an ischemic event, disruptive changes in the healthy myocardium may gradually develop and may ultimately turn into fibrotic scar. While these structural changes have been described by conventional imaging modalities mostly on a macroscopic scale-i.e., late gadolinium enhancement at magnetic resonance imaging (MRI)-in recent years, novel imaging methods have shown the potential to unveil an even more detailed picture of the postischemic myocardial phenomena. These new methods may bring advances in the understanding of ischemic heart disease with potential major changes in the current clinical practice. In this review article, we provide an overview of the emerging methods for the non-invasive characterization of ischemic heart disease, including coronary ultrafast Doppler angiography, photon-counting computed tomography (CT), micro-CT (for preclinical studies), low-field and ultrahigh-field MRI, and 11C-methionine positron emission tomography. In addition, we discuss new opportunities brought by artificial intelligence, while addressing promising future scenarios and the challenges for the application of artificial intelligence in the field of cardiac imaging.
View details for DOI 10.1186/s41747-021-00207-3
View details for PubMedID 33763754
CTA pulmonary artery enlargement in patients with severe aortic stenosis: Prognostic impact after TAVR.
Journal of cardiovascular computed tomography
BACKGROUND: Identifying high-risk patients who will not derive substantial survival benefit from TAVR remains challenging. Pulmonary hypertension is a known predictor of poor outcome in patients undergoing TAVR and correlates strongly with pulmonary artery (PA) enlargement on CTA. We sought to evaluate whether PA enlargement, measured on pre-procedural computed tomography angiography (CTA), is associated with 1-year mortality in patients undergoing TAVR.METHODS: We retrospectively included 402 patients undergoing TAVR between July 2012 and March 2016. Clinical parameters, including Society of Thoracic Surgeons (STS) score and right ventricular systolic pressure (RVSP) estimated by transthoracic echocardiography were reviewed. PA dimensions were measured on pre-procedural CTAs. Association between PA enlargement and 1-year mortality was analyzed. Kaplan-Meier and Cox proportional hazards regression analyses were performed.RESULTS: The median follow-up time was 433 (interquartiles 339-797) days. A total of 56/402 (14%) patients died within 1 year after TAVR. Main PA area (area-MPA) was independently associated with 1-year mortality (hazard ratio per standard deviation equal to 2.04 [95%-confidence interval (CI) 1.48-2.76], p<0.001). Area under the curve (95%-CI) of the clinical multivariable model including STS-score and RVSP increased slightly from 0.67 (0.59-0.75) to 0.72 (0.72-0.89), p=0.346 by adding area-MPA. Although the AUC increased, differences were not significant (p=0.346). Kaplan-Meier analysis showed that mortality was significantly higher in patients with a pre-procedural non-indexed area-MPA of ≥7.40cm2 compared to patients with a smaller area-MPA (mortality 23% vs. 9%; p<0.001).CONCLUSIONS: Enlargement of MPA on pre-procedural CTA is independently associated with 1-year mortality after TAVR.
View details for DOI 10.1016/j.jcct.2021.03.004
View details for PubMedID 33795188
White matter hyperintensities classified according to intensity and spatial location reveal specific associations with cognitive performance.
2021; 30: 102616
White matter hyperintensities (WMHs) on T2-weighted images are radiological signs of cerebral small vessel disease. As their total volume is variably associated with cognition, a new approach that integrates multiple radiological criteria is warranted. Location may matter, as periventricular WMHs have been shown to be associated with cognitive impairments. WMHs that appear as hypointense in T1-weighted images (T1w) may also indicate the most severe component of WMHs. We developed an automatic method that sub-classifies WMHs into four categories (periventricular/deep and T1w-hypointense/nonT1w-hypointense) using MRI data from 684 community-dwelling older adults from the Whitehall II study. To test if location and intensity information can impact cognition, we derived two general linear models using either overall or subdivided volumes. Results showed that periventricular T1w-hypointense WMHs were significantly associated with poorer performance in the trail making A (p=0.011), digit symbol (p=0.028) and digit coding (p=0.009) tests. We found no association between total WMH volume and cognition. These findings suggest that sub-classifying WMHs according to both location and intensity in T1w reveals specific associations with cognitive performance.
View details for DOI 10.1016/j.nicl.2021.102616
View details for PubMedID 33743476
AI applications to medical images: From machine learning to deep learning.
Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)
2021; 83: 9–24
PURPOSE: Artificial intelligence (AI) models are playing an increasing role in biomedical research and healthcare services. This review focuses on challenges points to be clarified about how to develop AI applications as clinical decision support systems in the real-world context.METHODS: A narrative review has been performed including a critical assessment of articles published between 1989 and 2021 that guided challenging sections.RESULTS: We first illustrate the architectural characteristics of machine learning (ML)/radiomics and deep learning (DL) approaches. For ML/radiomics, the phases of feature selection and of training, validation, and testing are described. DL models are presented as multi-layered artificial/convolutional neural networks, allowing us to directly process images. The data curation section includes technical steps such as image labelling, image annotation (with segmentation as a crucial step in radiomics), data harmonization (enabling compensation for differences in imaging protocols that typically generate noise in non-AI imaging studies) and federated learning. Thereafter, we dedicate specific sections to: sample size calculation, considering multiple testing in AI approaches; procedures for data augmentation to work with limited and unbalanced datasets; and the interpretability of AI models (the so-called black box issue). Pros and cons for choosing ML versus DL to implement AI applications to medical imaging are finally presented in a synoptic way.CONCLUSIONS: Biomedicine and healthcare systems are one of the most important fields for AI applications and medical imaging is probably the most suitable and promising domain. Clarification of specific challenging points facilitates the development of such systems and their translation to clinical practice.
View details for DOI 10.1016/j.ejmp.2021.02.006
View details for PubMedID 33662856
White Matter Hyperintensities Quantification in Healthy Adults: A Systematic Review and Meta-Analysis.
Journal of magnetic resonance imaging : JMRI
BACKGROUND: Although white matter hyperintensities (WMH) volumetric assessment is now customary in research studies, inconsistent WMH measures among homogenous populations may prevent the clinical usability of this biomarker.PURPOSE: To determine whether a point estimate and reference standard for WMH volume in the healthy aging population could be determined.STUDY TYPE: Systematic review and meta-analysis.POPULATION: In all, 9716 adult subjects from 38 studies reporting WMH volume were retrieved following a systematic search on EMBASE.FIELD STRENGTH/SEQUENCE: 1.0T, 1.5T, or 3.0T/fluid-attenuated inversion recovery (FLAIR) and/or proton density/T2 -weighted fast spin echo sequences or gradient echo T1 -weighted sequences.ASSESSMENT: After a literature search, sample size, demographics, magnetic field strength, MRI sequences, level of automation in WMH assessment, study population, and WMH volume were extracted.STATISTICAL TESTS: The pooled WMH volume with 95% confidence interval (CI) was calculated using the random-effect model. The I2 statistic was calculated as a measure of heterogeneity across studies. Meta-regression analysis of WMH volume on age was performed.RESULTS: Of the 38 studies analyzed, 17 reported WMH volume as the mean and standard deviation (SD) and were included in the meta-analysis. Mean and SD of age was 66.11±10.92years (percentage of men 50.45%±21.48%). Heterogeneity was very high (I2 = 99%). The pooled WMH volume was 4.70cm3 (95% CI: 3.88-5.53cm3 ). At meta-regression analysis, WMH volume was positively associated with subjects' age (beta = 0.358cm3 per year, P<0.05, R2 = 0.27).DATA CONCLUSION: The lack of standardization in the definition of WMH together with the high technical variability in assessment may explain a large component of the observed heterogeneity. Currently, volumes of WMH in healthy subjects are not comparable between studies and an estimate and reference interval could not be determined.LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1.
View details for DOI 10.1002/jmri.27479
View details for PubMedID 33345393
Breast arterial calcifications as a biomarker of cardiovascular risk: radiologists' awareness, reporting, and action. A survey among the EUSOBI members.
OBJECTIVES: To investigate the knowledge of radiologists on breast arterial calcifications (BAC) and attitude about BAC reporting, communication to women, and subsequent action.METHODS: An online survey was offered to EUSOBI members, with 17 questions focused on demographics, level of experience, clinical setting, awareness of BAC association with cardiovascular risk, mammographic reporting, modality of BAC assessment, and action habits. Descriptive statistics were used.RESULTS: Among 1084 EUSOBI members, 378 (34.9%) responded to the survey, 361/378 (95.5%) radiologists, 263 females (69.6%), 112 males (29.6%), and 3 (0.8%) who did not specify their gender. Of 378 respondents, 305 (80.7%) declared to be aware of BAC meaning in terms of cardiovascular risk and 234 (61.9%) to routinely include BAC in mammogram reports, when detected. Excluding one inconsistent answer, simple annotation of BAC presence was declared by 151/233 (64.8%), distinction between low versus extensive BAC burden by 59/233 (25.3%), and usage of an ordinal scale by 22/233 (9.5%) and of a cardinal scale by 1/233 (0.4%). Among these 233 radiologists reporting BAC, 106 (45.5%) declared to orally inform the woman and, in case of severe BAC burden, 103 (44.2%) to investigate cardiovascular history, and 92 (39.5%) to refer the woman to a cardiologist.CONCLUSION: Among EUSOBI respondents, over 80% declared to be aware of BAC cardiovascular meaning and over 60% to include BAC in the report. Qualitative BAC assessment predominates. About 40% of respondents who report on BAC, in the case of severe BAC burden, investigate cardiovascular history and/or refer the woman to a cardiologist.KEY POINTS: Of 1084 EUSOBI members, 378 (35%) participated: 81% of respondents are aware of breast arterial calcification (BAC) cardiovascular meaning and 62% include BAC in the mammogram report. Of those reporting BAC, description of presence was declared by 65%, low versus extensive burden distinction by 25%, usage of an ordinal scale by 10%, and of acardinal scale by 0.4%; 46% inform the womanand, in case of severe BAC burden, 44% examine cardiovascular history, and 40% refer her to a cardiologist. European breast radiologists may be ready for large-scale studies to ascertain the role of BAC assessment in the comprehensive framework of female cardiovascular disease prevention.
View details for DOI 10.1007/s00330-020-07136-6
View details for PubMedID 32851451
A quantitative analysis of metal artifact reduction algorithm performance in volume correction with 3 CBCT devices.
Oral surgery, oral medicine, oral pathology and oral radiology
OBJECTIVE: The aim of this study was to quantitatively assess the performance of metal artifact reduction (MAR) algorithms on the volume of metal cylinders, considering the influence of materials, positions, and fields of view (FOVs), by using 3 cone beam computed tomography (CBCT) devices (NewTom VGi evo, Picasso Trio, and ProMax 3-D Max).STUDY DESIGN: Nine phantoms containing cylinders of amalgam, copper-aluminum (CuAl) metal alloy, and titanium, combined in up to 3 positions, were scanned by using 2 different FOVs. MATLAB software was used to evaluate the differences between volumes before and after MAR application, and the possible interference of materials, positions, and FOVs. Wilcoxon's test and the Kruskal-Wallis test were used at a level of significance of 5%.RESULTS: In general, images containing amalgam and CuAl showed a significant difference in volume before and after MAR application. However, no significant difference after MAR was observed (P > .05) relative to positions and FOVs. MAR had an impact on the cylinder volumes only in the NewTom VGi evo and ProMax 3-D Max scanners.CONCLUSIONS: The performance of MAR algorithms in volume correction of metal objects is dependent on the materials and the CBCT unit.
View details for DOI 10.1016/j.oooo.2020.03.049
View details for PubMedID 32439517
Opening the black box of machine learning in radiology: can the proximity of annotated cases be a way?
European radiology experimental
2020; 4 (1): 30
Machine learning (ML) and deep learning (DL) systems, currently employed in medical image analysis, are data-driven models often considered as black boxes. However, improved transparency is needed to translate automated decision-making to clinical practice. To this aim, we propose a strategy to open the black box by presenting to the radiologist the annotated cases (ACs) proximal to the current case (CC), making decision rationale and uncertainty more explicit. The ACs, used for training, validation, and testing in supervised methods and for validation and testing in the unsupervised ones, could be provided as support of the ML/DL tool. If the CC is localised in a classification space and proximal ACs are selected by proper metrics, the latter ones could be shown in their original form of images, enriched with annotation to radiologists, thus allowing immediate interpretation of the CC classification. Moreover, the density of ACs in the CC neighbourhood, their image saliency maps, classification confidence, demographics, and clinical information would be available to radiologists. Thus, encrypted information could be transmitted to radiologists, who will know model output (what) and salient image regions (where) enriched by ACs, providing classification rationale (why). Summarising, if a classifier is data-driven, let us make its interpretation data-driven too.
View details for DOI 10.1186/s41747-020-00159-0
View details for PubMedID 32372200
Image quality of late gadolinium enhancement in cardiac magnetic resonance with different doses of contrast material in patients with chronic myocardial infarction.
European radiology experimental
2020; 4 (1): 21
BACKGROUND: Contrast-enhanced cardiac magnetic resonance (CMR) is pivotal for evaluating chronic myocardial infarction (CMI). Concerns about safety of gadolinium-based contrast agents favour dose reduction. We assessed image quality of scar tissue in CMRs performed with different doses of gadobutrol in CMI patients.METHODS: Informed consent was waived for this Ethics Committee-approved single-centre retrospective study. Consecutive contrast-enhanced CMRs from CMI patients were retrospectively analysed according to the administered gadobutrol dose (group A, 0.10 mmol/kg; group B, 0.15 mmol/kg; group C, 0.20 mmol/kg). We calculated the signal-to-noise ratio for scar tissue (SNRscar) and contrast-to-noise ratio between scar and either remote myocardium (CNRscar-rem) or blood (CNRscar-blood).RESULTS: Of 79 CMRs from 79 patients, 22 belonged to group A, 26 to group B, and 31 to group C. The groups were homogeneous for age, sex, left ventricular morpho-functional parameters, and percentage of scar tissue over whole myocardium (p ≥ 0.300). SNRscar was lower in group A (46.4; 40.3-65.1) than in group B (70.1; 52.2-111.5) (p = 0.013) and group C (72.1; 59.4-100.0) (p = 0.002), CNRscar-rem was lower in group A (62.9; 52.2-87.4) than in group B (96.5; 73.1-152.8) (p = 0.008) and in group C (103.9; 83.9-132.0) (p = 0.001). No other significant differences were found (p ≥ 0.335).CONCLUSIONS: Gadobutrol at 0.10 mmol/kg provides inferior scar image quality of CMI than 0.15 and 0.20 mmol/kg; the last two dosages seem to provide similar LGE. Thus, for CMR of CMI, 0.15 mmol/kg of gadobutrol can be suggested instead of 0.20 mmol/kg, with no hindrance to scar visualisation. Dose reduction would not impact on diagnostic utility of CMR examinations.
View details for DOI 10.1186/s41747-020-00149-2
View details for PubMedID 32242266
Novel imaging biomarkers: epicardial adipose tissue evaluation.
The British journal of radiology
Epicardial adipose tissue (EAT) is a metabolically activated beige adipose tissue, non-homogeneously surrounding the myocardium. Physiologically, EAT regulates toxic fatty acids, protects the coronary arteries against mechanical strain, regulates proinflammatory cytokines, stimulates the production of nitric oxide, reduces oxidative stress, and works as a thermogenic source against hypothermia. Conversely, EAT has pathologic paracrine interactions with the surrounded vessels, and might favour the onset of atrial fibrillation. In addition, initial atherosclerotic lesions can promote inflammation and trigger the EAT production of cytokines increasing vascular inflammation, which, in turn, may help the development of collateral vessels but also of self-stimulating, dysregulated inflammatory process, increasing coronary artery disease severity. Variations in EAT were also linked to metabolic syndrome. Echocardiography first estimated EAT measuring its thickness on the free wall of the right ventricle but does not allow accurate volumetric EAT estimates. Cardiac CT (CCT) and cardiac MR (CMR) allow for three-dimensional EAT estimates, the former showing higher spatial resolution and reproducibility but being limited by radiation exposure and long segmentation times, the latter being radiation-free but limited by lower spatial resolution and reproducibility, higher cost, and difficulties for obese patients. EAT radiodensity at CCT could to be related to underlying metabolic processes. The correlation between EAT and response to certain pharmacological therapies has also been investigated, showing promising results. In the future, semi-automatic or fully automatic techniques, machine/deep-learning methods, if validated, will facilitate research for various EAT measures and may find a place in CCT/CMR reporting.
View details for DOI 10.1259/bjr.20190770
View details for PubMedID 31782934
Screening mammography beyond breast cancer: breast arterial calcifications as a sex-specific biomarker of cardiovascular risk
EUROPEAN JOURNAL OF RADIOLOGY
2019; 119: 108636
To highlight the importance of quantitative breast arterial calcifications (BAC) assessment for an effective stratification of cardiovascular (CV) risk in women, for whom current preventive strategies are inadequate. BAC, easily detectable on mammograms, are associated with CV disease and represent a potential imaging biomarker for CV disease prevention in women.We summarized the available evidence on this topic.Age, parity, diabetes, and hyperlipidemia were found to positively correlate with BAC. Women with BAC have a higher CV risk than those without BAC: the relative risk was reported to be 1.4 for transient ischemic attack/stroke, 1.5 for thrombosis, 1.8 for myocardial infarction; the reported hazard ratio was 1.32 for coronary artery disease (CAD), 1.52 for heart failure, 1.29 for CV death, 1.44 for death from CAD. However, BAC do not alarm radiologists; when reported, they are commonly mentioned as "present", not impacting on CV decision-making. Of 18 published studies, 9 reported only presence/absence of BAC, 4 used a semi-quantitative scale, and 5 a continuous scale (with manual, automatic or semiautomatic segmentation). Various appearance, topological complexity, and vessels overlap make BAC quantification difficult to standardize. Nevertheless, machine learning approaches showed promising results in BAC quantification on mammograms.There is a strong rationale for mammography to become a dual test for breast cancer screening and CV disease prevention. However, robust and automated quantification methods are needed for a deeper insight on the association between BAC and CV disease, to stratifying CV risk and define personalized preventive actions.
View details for DOI 10.1016/j.ejrad.2019.08.005
View details for Web of Science ID 000487022000018
View details for PubMedID 31493727
3D Facial morphology in children affected by spinal muscular atrophy type 2 (SMAII).
European journal of orthodontics
OBJECTIVES: The main objective of this study was to assess the three-dimensional facial characteristics of children affected by spinal muscular atrophy (SMA), a severe muscular disorder characterized by hypotonia, areflexia, weakness, and respiratory impairment.MATERIALS/METHODS: Stereophotogrammetric facial scans from 22 SMA type II patients aged 2-7 years were obtained. Data were analysed using both inter-landmark distances and principal component analysis and compared with data collected from matched control subjects.RESULTS: Patients had wider transverse facial diameters, but smaller biocular width. Middle and lower anterior face heights were increased, whereas the mandibular ramus was shorter, with a reduced posterior-to-anterior face height ratio. Facial width-to-length ratio was reduced. In the sagittal plane, mandibular body length, and facial divergence were increased, whereas the gonial angles were decreased. In the horizontal plane, lower facial convexity was greater in patients, whereas mandibular convexity was smaller. Patients had smaller and down-slanted eye fissures, with a larger and more vertically developed nose.LIMITATIONS: This study assessed a relatively small number of patients, due to the rare frequency of SMA type II.CONCLUSIONS/IMPLICATIONS: SMA type II children possess peculiar facial alterations that may be due to the altered muscular activity. As feeding problems may derive also by malocclusion and masticatory muscular alterations, a detailed assessment of the craniofacial individual alterations should be considered in the standards of care of these patients.
View details for DOI 10.1093/ejo/cjz071
View details for PubMedID 31529029
MRI-Derived Biomarkers Related to Sarcopenia: A Systematic Review
JOURNAL OF MAGNETIC RESONANCE IMAGING
2020; 51 (4): 1117–27
MRI allows quantitatively assessing muscle quantity and quality.To summarize the role of MRI as a noninvasive technique for the identification of in vivo surrogate biomarker of sarcopenia.Systematic review.In April 2019, a systematic literature search (Medline/EMBASE) was performed to identify articles on the topic at issue.No field strength or sequence restrictions.After a literature search, study design, aim, sample size, demographics, magnetic field strength, imaged body region, MRI sequences, and imaging biomarker were extracted.Data are presented as frequencies and percentages.From 69 records identified through search query, 18 articles matched the inclusion criteria. All articles were published from 2012 and had a mainly prospective design (14/18, 78%). Sample size ranged from 9 to 284 subjects, for a total of 1706 enrolled subjects. Healthy subjects were enrolled or retrospectively selected in 8/18 (44%) articles, corresponding to 658 (39%) healthy subjects. Magnetic field strength was 1.5 or 3T in 14/18 (78%) studies. The most analyzed body regions were the thigh (7/18, 39%) and the trunk (6/18, 33%). Stratifying studies according to their aim, 13/18 (72%) studies focused on muscle quality and quantity, 3/18 (17%) studies on outcome prediction, and 2/18 articles (11%) addressed both aims. A wide set of MRI biomarkers have been proposed. Muscle cross-sectional area was the most used for muscle quantity estimation, while quantitative biomarkers of muscle fat content or fiber architecture were proposed to assess muscle quality.The proposed biomarkers were assessed using different MRI sequences for different body regions in different subjects/patient cohorts, pointing out a lack of standardization on this topic. Future studies should test and compare the performance of proposed MRI biomarkers for sarcopenia characterization and quantification using a standardized experimental setup.1 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1117-1127.
View details for DOI 10.1002/jmri.26931
View details for Web of Science ID 000486312300001
View details for PubMedID 31515891
Artificial Intelligence for Breast MRI in 2008-2018: A Systematic Mapping Review
AMERICAN JOURNAL OF ROENTGENOLOGY
2019; 212 (2): 280–92
The purpose of this study is to review literature from the past decade on applications of artificial intelligence (AI) to breast MRI.In June 2018, a systematic search of the literature was performed to identify articles on the use of AI in breast MRI. For each article identified, the surname of the first author, year of publication, journal of publication, Web of Science Core Collection journal category, country of affiliation of the first author, study design, dataset, study aim(s), AI methods used, and, when available, diagnostic performance were recorded.Sixty-seven studies, 58 (87%) of which had a retrospective design, were analyzed. When journal categories were considered, 36% of articles were identified as being included in the radiology and imaging journal category. Contrast-enhanced sequences were used for most AI applications (n = 50; 75%) and, on occasion, were combined with other MRI sequences (n = 8; 12%). Four main clinical aims were addressed: breast lesion classification (n = 36; 54%), image processing (n = 14; 21%), prognostic imaging (n = 9; 13%), and response to neoadjuvant therapy (n = 8; 12%). Artificial neural networks, support vector machines, and clustering were the most frequently used algorithms, accounting for 66%. The performance achieved and the most frequently used techniques were then analyzed according to specific clinical aims. Supervised learning algorithms were primarily used for lesion characterization, with the AUC value from ROC analysis ranging from 0.74 to 0.98 (median, 0.87) and with that from prognostic imaging ranging from 0.62 to 0.88 (median, 0.80), whereas unsupervised learning was mainly used for image processing purposes.Interest in the application of advanced AI methods to breast MRI is growing worldwide. Although this growth is encouraging, the current performance of AI applications in breast MRI means that such applications are still far from being incorporated into clinical practice.
View details for DOI 10.2214/AJR.18.20389
View details for Web of Science ID 000461833400014
View details for PubMedID 30601029
Brain vascular changes in adults with congenital heart disease: A systematic review
2019; 23: 101873
Less information is available on brain integrity in adults with congenital heart disease than on brain changes in newborns and children with heart defects. Nevertheless, the number of adults with congenital heart disease is increasing rapidly and it has been shown that adults with congenital heart disease develop dementia almost twice as frequently as adults in the general population. In the context of a rapidly growing congenital heart disease population, neuroradiological-oriented investigations of biomarkers distinctive for vascular damage, brain aging, and possible cognitive impairment is a crucial challenge. We provide an overview of the existing literature on neuroimaging studies in adults with congenital heart disease and discuss methodology issues to further investigate this subject. Overall, we aim to raise awareness of the importance of brain health studies in adults with congenital heart disease given the likely increasing impact on social and healthcare systems.
View details for DOI 10.1016/j.nicl.2019.101873
View details for Web of Science ID 000485804400003
View details for PubMedID 31158693
View details for PubMedCentralID PMC6545412
Longitudinal morphometric analysis of dental arch of childern wan cleft lip and palate: 3D stereophotogrammetry study
ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY ORAL RADIOLOGY
2018; 126 (6): 463–68
This study aimed to perform a longitudinal morphometric analysis of the alterations of the maxillary dental arches in children with cleft lip and palate before and after primary lip and/or palate surgeries using a 3-dimensional stereophotogrammetry system.The sample consisted of dental casts of 60 children with complete unilateral cleft lip (UCL) and complete unilateral cleft lip and palate (UCLP). Dental arches were evaluated before cheiloplasty (T1), after cheiloplasty (T2), and 1 year after palatoplasty (T3). Independent t test and Mann-Whitney U test were used for intergroup comparisons, and paired t test, Wilcoxon's test, and repeated-measures analysis of variance (ANOVA), followed by Tukey's test, were used for intragroup comparisons.At T1, the intercanine and intertuberosity distances in the UCLP group were statistically greater than those in the UCL group. At T2, the maxillary dimensions significantly increased, except for the intertuberosity distance in UCL. Between T1 and T3, the intercanine distance and the anterior length decreased significantly, whereas the intertuberosity distance and the total length of the palate increased significantly.Our results indicated that the primary lip surgery altered the development of dental arches, evidently in children with UCLP. The primary palate surgery interfered in the growth of the anterior palatal region in the UCLP group. Children with UCLP had more restricted development of the maxillary dental arch compared with children with UCL.
View details for DOI 10.1016/j.oooo.2018.08.012
View details for Web of Science ID 000453266800005
View details for PubMedID 30249537
Three-Dimensional Stereophotogrammetric Evaluation of the Efficacy of Autologous Fat Grafting in the Treatment of Parry-Romberg Syndrome
JOURNAL OF CRANIOFACIAL SURGERY
2018; 29 (8): 2124–27
Autologous fat grafting is a surgical procedure used to correct volumetric defects, atrophies, and sclerosis. Three-dimensional (3D) facial photography may enable researchers to quantify the success of surgical procedures through volumetric and surface assessments. Using 3D photography, the authors assessed the results of autologous fat grafting performed in a 15-year-old patient affected by Parry-Romberg syndrome, a rare condition resulting in progressive hemifacial atrophy of skin, subcutaneous tissues and, ultimately, bone. Stereophotogrammetric acquisitions were performed before and 4 months after the surgical intervention. The obtained results were objectively assessed in terms of facial symmetry through calculation of root mean square deviation point-to-point distance between the treated and healthy side, and volume modifications between pre- and postsurgical 3D facial scans. Four months after surgery, 73% of injected adipose tissue was resorbed, whereas facial symmetry increased up to 63%. The proposed method is not invasive and provides quantitative information about the surgical and esthetic outcomes. Clinicians could better plan surgery, and the patients could be more motivated and compliant to the treatment.
View details for DOI 10.1097/SCS.0000000000004664
View details for Web of Science ID 000467707800059
View details for PubMedID 29894458
Artificial intelligence in medical imaging: threat or opportunity? Radiologists again at the forefront of innovation in medicine.
European radiology experimental
2018; 2 (1): 35
One of the most promising areas of health innovation is the application of artificial intelligence (AI), primarily in medical imaging. This article provides basic definitions of terms such as "machine/deep learning" and analyses the integration of AI into radiology. Publications on AI have drastically increased from about 100-150 per year in 2007-2008 to 700-800 per year in 2016-2017. Magnetic resonance imaging and computed tomography collectively account for more than 50% of current articles. Neuroradiology appears in about one-third of the papers, followed by musculoskeletal, cardiovascular, breast, urogenital, lung/thorax, and abdomen, each representing 6-9% of articles. With an irreversible increase in the amount of data and the possibility to use AI to identify findings either detectable or not by the human eye, radiology is now moving from a subjective perceptual skill to a more objective science. Radiologists, who were on the forefront of the digital era in medicine, can guide the introduction of AI into healthcare. Yet, they will not be replaced because radiology includes communication of diagnosis, consideration of patient's values and preferences, medical judgment, quality assurance, education, policy-making, and interventional procedures. The higher efficiency provided by AI will allow radiologists to perform more value-added tasks, becoming more visible to patients and playing a vital role in multidisciplinary clinical teams.
View details for DOI 10.1186/s41747-018-0061-6
View details for PubMedID 30353365
Artificial intelligence as a medical device in radiology: ethical and regulatory issues in Europe and the United States
INSIGHTS INTO IMAGING
2018; 9 (5): 745–53
Worldwide interest in artificial intelligence (AI) applications is growing rapidly. In medicine, devices based on machine/deep learning have proliferated, especially for image analysis, presaging new significant challenges for the utility of AI in healthcare. This inevitably raises numerous legal and ethical questions. In this paper we analyse the state of AI regulation in the context of medical device development, and strategies to make AI applications safe and useful in the future. We analyse the legal framework regulating medical devices and data protection in Europe and in the United States, assessing developments that are currently taking place. The European Union (EU) is reforming these fields with new legislation (General Data Protection Regulation [GDPR], Cybersecurity Directive, Medical Devices Regulation, In Vitro Diagnostic Medical Device Regulation). This reform is gradual, but it has now made its first impact, with the GDPR and the Cybersecurity Directive having taken effect in May, 2018. As regards the United States (U.S.), the regulatory scene is predominantly controlled by the Food and Drug Administration. This paper considers issues of accountability, both legal and ethical. The processes of medical device decision-making are largely unpredictable, therefore holding the creators accountable for it clearly raises concerns. There is a lot that can be done in order to regulate AI applications. If this is done properly and timely, the potentiality of AI based technology, in radiology as well as in other fields, will be invaluable. TEACHING POINTS: • AI applications are medical devices supporting detection/diagnosis, work-flow, cost-effectiveness. • Regulations for safety, privacy protection, and ethical use of sensitive information are needed. • EU and U.S. have different approaches for approving and regulating new medical devices. • EU laws consider cyberattacks, incidents (notification and minimisation), and service continuity. • U.S. laws ask for opt-in data processing and use as well as for clear consumer consent.
View details for DOI 10.1007/s13244-018-0645-y
View details for Web of Science ID 000448802900011
View details for PubMedID 30112675
View details for PubMedCentralID PMC6206380
Does Tetralogy of Fallot affect brain aging? A proof-of-concept study
2018; 13 (8): e0202496
The impact of congenital heart disease on brain aging has not been extensively investigated. We evaluated cerebral microbleeds and white matter hyperintensities on brain magnetic resonance imaging in adult patients with tetralogy of Fallot (ToF). Ten ToF patients (6 women, 4 men; aged 21-58 years; New York Heart Association [NYHA] class 1-2) were prospectively enrolled and underwent a T1-weighted, a T2-weighted dark fluid, and a T2*-weighted scans. Ten age- and sex-matched controls were prospectively recruited and subjected to the same acquisition protocol. Cerebral microbleeds (CMBs) were manually counted while white matter hyperintensities (WMHs) were segmented using ITK-Snap. Wilcoxon signed-rank test, Spearman correlation, and Bland-Altman statistics were used. The median (interquartile range [IQR]) age was 45.0 (30.5-49.5) years in ToF patients and 46.0 (30.5-49.8) years in controls. The median (IQR) of the number of CMBs was 6.0 (4.0-7.8) in ToF patients and 0 (0.0-0.0) in controls (p = 0.002). The WMHs burden was 2,506 (1,557-2,900) mm3 for ToF patients and 2,212 (1,860-2,586) mm3 for controls (p = 0.160). Moreover, a positive significant correlation was found between the WMHs burden and the NYHA class (ρ = 0.80, p = 0.005). Inter-operator concordance rate for the presence/absence of CMBs was 90%; the reproducibility for the WMHs burden was 77%. In conclusion, we found more cerebral microbleeds and a higher WMHs burden in adult ToF patients than in controls. This preliminary comparison supports the hypothesis of an early brain aging in ToF patients. Larger studies are warranted.
View details for DOI 10.1371/journal.pone.0202496
View details for Web of Science ID 000442284500009
View details for PubMedID 30130369
View details for PubMedCentralID PMC6103512
A Quantitative Assessment of Lip Movements in Different Facial Expressions Through 3-Dimensional on 3-Dimensional Superimposition: A Cross-Sectional Study
JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY
2018; 76 (7): 1532–38
The quantitative assessment of facial modifications from mimicry is of relevant interest for the rehabilitation of patients who can no longer produce facial expressions. This study investigated a novel application of 3-dimensional on 3-dimensional superimposition for facial mimicry.This cross-sectional study was based on 10 men 30 to 40 years old who underwent stereophotogrammetry for neutral, happy, sad, and angry expressions. Registration of facial expressions on the neutral expression was performed. Root mean square (RMS) point-to-point distance in the labial area was calculated between each facial expression and the neutral one and was considered the main parameter for assessing facial modifications. In addition, effect size (Cohen d) was calculated to assess the effects of labial movements in relation to facial modifications.All participants were free from possible facial deformities, pathologies, or trauma that could affect facial mimicry. RMS values of facial areas differed significantly among facial expressions (P = .0004 by Friedman test). The widest modifications of the lips were observed in happy expressions (RMS, 4.06 mm; standard deviation [SD], 1.14 mm), with a statistically relevant difference compared with the sad (RMS, 1.42 mm; SD, 1.15 mm) and angry (RMS, 0.76 mm; SD, 0.45 mm) expressions. The effect size of labial versus total face movements was limited for happy and sad expressions and large for the angry expression.This study found that a happy expression provides wider modifications of the lips than the other facial expressions and suggests a novel procedure for assessing regional changes from mimicry.
View details for DOI 10.1016/j.joms.2017.11.017
View details for Web of Science ID 000436415300027
View details for PubMedID 29245003
Cone beam computed tomography in implant dentistry: recommendations for clinical use
BMC ORAL HEALTH
2018; 18: 88
In implant dentistry, three-dimensional (3D) imaging can be realised by dental cone beam computed tomography (CBCT), offering volumetric data on jaw bones and teeth with relatively low radiation doses and costs. The latter may explain why the market has been steadily growing since the first dental CBCT system appeared two decades ago. More than 85 different CBCT devices are currently available and this exponential growth has created a gap between scientific evidence and existing CBCT machines. Indeed, research for one CBCT machine cannot be automatically applied to other systems.Supported by a narrative review, recommendations for justified and optimized CBCT imaging in oral implant dentistry are provided.The huge range in dose and diagnostic image quality requires further optimization and justification prior to clinical use. Yet, indications in implant dentistry may go beyond diagnostics. In fact, the inherent 3D datasets may further allow surgical planning and transfer to surgery via 3D printing or navigation. Nonetheless, effective radiation doses of distinct dental CBCT machines and protocols may largely vary with equivalent doses ranging between 2 to 200 panoramic radiographs, even for similar indications. Likewise, such variation is also noticed for diagnostic image quality, which reveals a massive variability amongst CBCT technologies and exposure protocols. For anatomical model making, the so-called segmentation accuracy may reach up to 200 μm, but considering wide variations in machine performance, larger inaccuracies may apply. This also holds true for linear measures, with accuracies of 200 μm being feasible, while sometimes fivefold inaccuracy levels may be reached. Diagnostic image quality may also be dramatically hampered by patient factors, such as motion and metal artefacts. Apart from radiodiagnostic possibilities, CBCT may offer a huge therapeutic potential, related to surgical guides and further prosthetic rehabilitation. Those additional opportunities may surely clarify part of the success of using CBCT for presurgical implant planning and its transfer to surgery and prosthetic solutions.Hence, dental CBCT could be justified for presurgical diagnosis, preoperative planning and peroperative transfer for oral implant rehabilitation, whilst striving for optimisation of CBCT based machine-dependent, patient-specific and indication-oriented variables.
View details for DOI 10.1186/s12903-018-0523-5
View details for Web of Science ID 000432724700003
View details for PubMedID 29764458
View details for PubMedCentralID PMC5952365
The face in marfan syndrome: A 3D quantitative approach for a better definition of dysmorphic features
2018; 31 (3): 380–86
Marfan syndrome (MFS) is a rare hereditable disorder of connective tissue caused by mutations in the fibrillin-1 gene FBN1. Timely diagnosis of MFS is essential to prevent life-threatening cardiovascular complications; nevertheless it can be difficult owing to the phenotypic variability of the syndrome. No clear quantitative definition of facial abnormalities associated with MFS is available. The aim of this study was to improve the definition of the facial phenotype associated with MFS and to verify the usefulness of a 3D noninvasive quantitative approach for its early recognition. 3D facial images of 61 Italian subjects with MFS, aged 16-64 years (21 males, 38 ± 15 years; 40 females, 41 ± 13 years) were obtained by stereophotogrammetry. From the coordinates of 17 soft-tissue facial landmarks, linear distances and angles were computed; z score values were calculated to compare patients with healthy reference subjects (400 males, 379 females) matched for sex and age. Student's t test was used for statistical comparisons. All subjects with MFS showed greater facial divergence (P < 0.001; mean z score +1.9) and a lower facial height index (P < 0.001; mean z score -1.9) than reference subjects, both values being influenced by a shorter mandibular ramus (P < 0.001; mean z score -1.9) and a mild but significant increase in facial height (P < 0.001; mean z score +1.2). Palpebral down-slanting was found in 85% of MFS subjects. There were no sex differences. Quantitative abnormalities identified in this study enrich information about the facial dysmorphism in MFS and confirm its usefulness for early recognition of the disease. Clin. Anat. 31:380-386, 2018. © 2017 Wiley Periodicals, Inc.
View details for DOI 10.1002/ca.23034
View details for Web of Science ID 000427113800014
View details for PubMedID 29226593
Fully automated contour detection of the ascending aorta in cardiac 2D phase-contrast MRI
MAGNETIC RESONANCE IMAGING
2018; 47: 77–82
In this study we proposed a fully automated method for localizing and segmenting the ascending aortic lumen with phase-contrast magnetic resonance imaging (PC-MRI).Twenty-five phase-contrast series were randomly selected out of a large population dataset of patients whose cardiac MRI examination, performed from September 2008 to October 2013, was unremarkable. The local Ethical Committee approved this retrospective study. The ascending aorta was automatically identified on each phase of the cardiac cycle using a priori knowledge of aortic geometry. The frame that maximized the area, eccentricity, and solidity parameters was chosen for unsupervised initialization. Aortic segmentation was performed on each frame using active contouring without edges techniques. The entire algorithm was developed using Matlab R2016b. To validate the proposed method, the manual segmentation performed by a highly experienced operator was used. Dice similarity coefficient, Bland-Altman analysis, and Pearson's correlation coefficient were used as performance metrics.Comparing automated and manual segmentation of the aortic lumen on 714 images, Bland-Altman analysis showed a bias of -6.68mm2, a coefficient of repeatability of 91.22mm2, a mean area measurement of 581.40mm2, and a reproducibility of 85%. Automated and manual segmentation were highly correlated (R=0.98). The Dice similarity coefficient versus the manual reference standard was 94.6±2.1% (mean±standard deviation).A fully automated and robust method for identification and segmentation of ascending aorta on PC-MRI was developed. Its application on patients with a variety of pathologic conditions is advisable.
View details for DOI 10.1016/j.mri.2017.11.010
View details for Web of Science ID 000428004500011
View details for PubMedID 29180100
3D-3D facial superimposition between monozygotic twins: A novel morphological approach to the assessment of differences due to environmental factors
2018; 31: 33–37
Distinction of one twin with respect to the other, based on external appearance, is challenging; nevertheless, facial morphology may provide individualizing features that may help distinguish twin siblings. This study aims at exposing an innovative method for the facial assessment in monozygotic twins for personal identification, based on the registration and comparison of 3D models of faces. Ten couples of monozygotic twins aged between 25 and 69 years were acquired twice by a stereophotogrammetric system (VECTRA-3D® M3: Canfield Scientific, Inc., Fairfield, NJ); the 3D reconstruction of each person was then registered and superimposed onto the model belonging to the same person (self-matches), the corresponding sibling (twin-matches) and to unrelated participants from the other couples (miss-matches); RMS (root mean square) point-to-point distances were automatically calculated for all the 220 superimpositions. One-way ANOVA was used to evaluate the differences among miss-matches, twin-matches and self-matches (p < .05). RMS values for self-matches, twin-matches and miss-matches were respectively 1.0 mm (SD: 0.3 mm), 1.9 mm (0.5 mm) and 3.4 mm (0.70 mm). Statistically significant differences were found among the three groups (p < .01). Comparing RMS values in the three groups, mean facial variability in twin siblings was 55.9% of that assessed between unrelated persons and about twice higher than that observed between models belonging to the same individual. The present study proposed an innovative method for the facial assessment of twin siblings, based on 3D surface analysis, which may provide additional information concerning the relation between genes and environment.
View details for DOI 10.1016/j.legalmed.2017.12.011
View details for Web of Science ID 000430526100009
View details for PubMedID 29291466
Breast arterial calcifications on mammography: intra- and inter-observer reproducibility of a semi-automatic quantification tool
2018; 123 (3): 168–73
A strong association between breast arterial calcifications (BAC) and cardiovascular disease has been demonstrated. However, BAC quantification tools are lacking. We evaluated the intra- and inter-observer reproducibility of a semi-automatic tool for BAC quantification on digital mammograms.A multivendor image dataset of 212 mammographic views, 106 cranio-caudal (CC) and 106 medio-lateral oblique (MLO), were retrospectively selected from 53 subjects if BAC were seen in at least one view. Images were segmented twice by two intensively trained residents in Radiodiagnostics with > 6-month experience in mammography using a semi-automatic software. The two observers (O1, O2) independently positioned rectangular ROIs where they recognized BAC on both CC and MLO views, separately. The adaptive thresholding algorithm automatically provided the BAC amount in mm2. Number, size, and position of the ROIs were observer-dependent. Total BAC amount was calculated for each patient. Bland-Altman analysis was used.Total BAC amount was 56.6 (IQR 18.1-91.1) and 41.0 (IQR 18.8-90.9) for O1 and O2, respectively. Intra-observer Bland-Altman analysis showed a bias of 11.9 mm2, a coefficient of repeatability of 32.7 mm2, an average measurement of 72.8 mm2, for a 55% reproducibility; the same data were - 7.0, 61.4, 63.4 mm2, and only 3%, respectively, for the inter-observer analysis.Our semi-automatic tool for BAC quantification showed a poor reproducibility. These results pointed out that the human identification of BAC represents the main source of variability. Further research is needed to translate BAC quantification into clinical practice.
View details for DOI 10.1007/s11547-017-0827-6
View details for Web of Science ID 000424785100002
View details for PubMedID 29086382
Volumetric assessment of sphenoid sinuses through segmentation on CT scan
SURGICAL AND RADIOLOGIC ANATOMY
2018; 40 (2): 193–98
Computed tomography represents the gold standard for the assessment of morphological characteristics of sphenoid sinuses, whose anatomy has acquired a novel interest because of the recent introduction of transsphenoidal surgery and robot-assisted procedures. One of the most relevant parameters for planning surgical intervention is the volume of sphenoid sinuses, and with time few population studies have been published. However, at present, no data are available concerning the relation between volume and anatomical variants of sphenoid sinuses.We retrospectively evaluated head CT-scans of 100 patients (age range 25-99 years; mean age males 45.0; mean age females 50.5 years) to calculate the volume of sphenoid sinuses through automatic segmentation. Possible statistically significant differences according to sex and variants of pneumatization, and type of sinus were assessed, respectively, through Student's t test and one-way ANOVA test (p < 0.05).Average volume of sphenoid sinuses in males was 10.005 ± 5.101 cm3, in females 7.920 ± 3.176 cm3. Differences according to sex were statistically significant (p < 0.05). Patients with pneumatization of pterygoid processes, dorsum sellae and anterior clinoid processes had a significantly higher volume than unaffected subjects. Moreover, differences of volume according to the type of sphenoid sinus were statistically significant (p < 0.05).Results show that volume of sphenoid sinuses strongly depend upon the type of sinus and possible pneumatization variants. Moreover, the important of ethnic variability is confirmed.
View details for DOI 10.1007/s00276-017-1949-1
View details for Web of Science ID 000426552000009
View details for PubMedID 29270712
Strain of ascending aorta on cardiac magnetic resonance in 1027 patients: Relation with age, gender, and cardiovascular disease
EUROPEAN JOURNAL OF RADIOLOGY
2018; 99: 34–39
To evaluate ascending aortic strain (AAS) with cardiac magnetic resonance (CMR) in a large consecutive series of patients with different types of cardiovascular disease (CVD).Two-dimensional phase-contrast gradient-echo sequences of the ascending aorta were retrospectively reviewed in 1027 patients (726 males, 301 females). Aortic lumen area was segmented using a semi-automatic approach to calculate AAS values. Subgroup analysis was performed for patients with normal CMR, tetralogy of Fallot (ToF), and ischemic heart disease (IHD). Multivariate and post-hoc analyses were performed to evaluate the effect of age, gender, and CVD on AAS values. Shapiro-Wilk, three- and two-way ANOVA, Mann-Whitney U, and Spearman correlation statistics were used.Multivariate analysis showed significant differences in AAS among decades of age (p<0.001), genders (p=0.006) and CVD subgroups (p<0.001) without interaction among these factors. A gender-related difference (higher AAS in females) was significant in ToF (p=0.008), while an AAS reduction during aging was observed in all CVD subgroups. Post-hoc analysis showed a significantly lower AAS in ToF and IHD patients compared to subjects with normal CMR (p<0.001).Differences in age, gender, and CVD independently affect AAS. The lower AAS observed in ToF fosters its assessment during follow-up in adulthood. Future studies on causes and clinical implications of a higher AAS in females affected by ToF are warranted.
View details for DOI 10.1016/j.ejrad.2017.12.002
View details for Web of Science ID 000423344100005
View details for PubMedID 29362149
Correlation between voxel-wise enhancement parameters on DCE-MRI and pathological prognostic factors in invasive breast cancers
2018; 123 (2): 91–97
To investigate the correlation between enhancement parameters on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and pathologic prognostic factors in invasive breast cancers (BCs).A total of 25 invasive BCs were included: 22 invasive ductal, 2 invasive lobular and 1 invasive mucinous. The tumor volume was segmented using a semi-automatic software (Olea Sphere). The following voxel-wise enhancement parameters were extracted: (1) time to peak enhancement; (2) signal intensity at peak (SIP); (3) peak enhancement percentage (PEP); (4) post-initial enhancement percentage (PIEP). The following pathological prognostic factors were considered for potential correlation: tumor (pT) and nodal (pN) stage, grading, perivascular/perineural invasion, estrogen/progesterone receptor status, Ki-67 proliferation, and HER2 expression. Spearman and Pearson correlation coefficients were calculated according with type of variable and data distribution.Tumor volume was 2.8 ± 2.0 cm3 (mean ± standard deviation [SD]). Mean SIP correlated with pT (ρ = 0.424, p = 0.035); mean PEP correlated with HER2 overexpression (ϕ = 0.471, p = 0.017) and pT (ρ = 0.449, p = 0.024). The percentage of voxels with fast PEP directly correlated with pT (ρ = 0.482, p = 0.015) and pN (ρ = 0.446, p = 0.026), while the percentage of voxels with slow PEP inversely correlated with pT (ρ = -0.421, p = 0.039) and pN (ρ = -0.481, p = 0.015). Segmentation time was 14.6 ± 1.3 min (mean ± SD).In invasive BCs, DCE-MRI voxel-wise enhancement parameters correlated with HER2, pT, and pN.
View details for DOI 10.1007/s11547-017-0809-8
View details for Web of Science ID 000423029600002
View details for PubMedID 28948442
Three-dimensional mandibular motion in skeletal Class III patients
CRANIO-THE JOURNAL OF CRANIOMANDIBULAR & SLEEP PRACTICE
2018; 36 (2): 113–20
The aim of the study was to analyze the characteristics and changes in mandibular condylar motion in patients with skeletal Class III malocclusion.Using a 3D motion analyzer, mandibular movements were recorded in 9 patients with skeletal Class III malocclusion and 22 control subjects with Angle Class I jaw relationships.Class III patients had a similar interincisor point displacement but a significantly reduced displacement of both condyles on the sagittal and frontal planes, with smaller translation paths than control subjects (right -9.4 mm; left -4.8 mm). The overall condylar rotation component was larger in Class III patients (right +8.8%; left +7.3%). The largest inter-group significant differences were observed in the first 10% of mouth opening, in which Class III patients had a larger rotating component than control subjects (+20%, p < 0.01).Condylar motion was reduced in skeletal Class III patients, in particular in the translational path.
View details for DOI 10.1080/08869634.2017.1299830
View details for Web of Science ID 000437378300008
View details for PubMedID 28303737
Quantitative evaluation of metal artifacts using different CBCT devices, high-density materials and field of views
CLINICAL ORAL IMPLANTS RESEARCH
2017; 28 (12): 1509–14
To objectively compare the influence of different cone-beam computed tomography (CBCT) devices, high-density materials and field of views (FOVs) on metal artifact expression.For this in vitro study, three customized acrylic resin phantoms containing high-density materials cylinders: titanium, copper-aluminum alloy and amalgam were scanned on three CBCT devices using high-resolution protocols, same voxel size (0.2 mm) and different FOVs. After fully automatic segmentation and image registration, the same region of interest was defined for the small and medium FOVs. The difference between the segmented and the real volume of the metal cylinders was assessed. Moreover for each segmented slice, the area difference between the segmented and the real axial section was determined. The artifacts on the background were measured as normalizing standard deviation of voxel values in the vicinity of the cylinder, in three different distances.Considerable differences were observed in volume measurements for all CBCTs devices and materials for both FOV sizes (up to 67%). The slice per slice area analysis indicated higher artifacts at the edges of the metal cylinder. Within the materials, amalgam and titanium had, respectively, the worst and best artifact expression in all the CBCT devices. Standard deviation values varied differently between the three distances in each device.Our in vitro study showed that different CBCT devices, high-density materials and FOV should be considered while evaluating CBCT images. More carefully, diagnosis conclusions should be drawn in images containing amalgam and copper-aluminum alloy.
View details for DOI 10.1111/clr.13019
View details for Web of Science ID 000416853000005
View details for PubMedID 28432698
Validation of a novel imaging approach using multi-slice CT and cone-beam CT to follow-up on condylar remodeling after bimaxillary surgery
INTERNATIONAL JOURNAL OF ORAL SCIENCE
2017; 9 (3): 139–44
The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography (MSCT) and postoperative cone-beam computed tomography (CBCT) images. Second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients (11 female and 9 male) who underwent bimaxillary surgery were semi-automatically extracted from MSCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant (P<0.05) mean bone volume decrease of 26.4%±11.4% (502.9 mm3±268.1 mm3). No significant effects of side, sex or age were found. Good to excellent (ICC>0.6) intra- and inter-observer reliability was observed for both MSCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel (0.4 mm) for MSCT (0.3 mm±0.2 mm) and CBCT (0.4 mm±0.3 mm), thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.
View details for DOI 10.1038/ijos.2017.22
View details for Web of Science ID 000412053800003
View details for PubMedID 28708129
View details for PubMedCentralID PMC5709543
The face of Glut1-DS patients: A 3D Craniofacial Morphometric Analysis
2017; 30 (5): 644–52
Glut1 deficiency syndrome (Glut1-DS) is a neurological and metabolic disorder caused by impaired transport of glucose across the blood brain barrier (BBB). Mutations on the SCL2A1 gene encoding the glucose transporter protein in the BBB cause the syndrome, which encompasses epilepsy, movement disorders, and mental delay. Such variability of symptoms presents an obstacle to early diagnosis. The patients seem to share some craniofacial features, and identification and quantification of these could help in prompt diagnosis and clinical management. We performed a three-dimensional morphometric analysis of the faces of 11 female Glut1-DS patients using a stereophotogrammetric system. Data were analyzed using both inter-landmark distances and Principal Component Analysis. Compared with data collected from age-, sex-, and ethnicity-matched control subjects, common and homogenous facial features were identified among patients, which were mainly located in the mandible and the eyes. Glut1-DS patients had a more anterior chin; their mandibular body was longer but the rami were shorter, with a reduced gonial angle; they had smaller and down-slanted eyes with a reduced intercanthal distance. This study highlights the importance of morphometric analysis for defining the facial anatomical characteristics of the syndrome better, potentially helping clinicians to diagnose Glut1-DS. Improved knowledge of the facial anatomy of these patients can provide insights into their facial and cerebral embryological development, perhaps further clarifying the molecular basis of the syndrome. Clin. Anat. 30:644-652, 2017. © 2017 Wiley Periodicals, Inc.
View details for DOI 10.1002/ca.22890
View details for Web of Science ID 000403349700021
View details for PubMedID 28459125
Stereophotogrammetric Evaluation of Labial Symmetry After Surgical Treatment of a Lymphatic Malformation
JOURNAL OF CRANIOFACIAL SURGERY
2017; 28 (4): E355–E358
Lymphatic malformations (LMs) are rare, nonmalignant masses, frequently involving the head and neck, potentially causing impairment to the surrounding anatomical structures. Major LMs frequently cause facial disfigurement with obvious consequences on self-esteem and social functioning. The attempt to restore symmetry is thus one of the main goals of treatment. In this study, the authors present a not-invasive method to objectively quantify the symmetry of the labial area before and after surgical treatment of a LM, affecting a 16-year-old woman. This was done with sequential three-dimensional stereophotogrammetric imaging and morphometric measurements. The method showed a high reproducibility and supplied quantitative indicators of the local degree of symmetry, helping clinicians in its objective assessment, and facilitating treatment planning and evaluation. A quantitative appraisal of the results can additionally improve patient adherence to a usually multistage therapy.
View details for DOI 10.1097/SCS.0000000000003601
View details for Web of Science ID 000402750600016
View details for PubMedID 28230604
As Low Dose as Sufficient Quality: Optimization of Cone-beam Computed Tomographic Scanning Protocol for Tooth Autotransplantation Planning and Follow-up in Children
JOURNAL OF ENDODONTICS
2017; 43 (2): 210–17
Tooth autotransplantation (TAT) offers a viable biological approach to tooth replacement in children. To enhance the outcome predictability of the TAT procedure, a cone-beam computed tomographic (CBCT)-based surgical planning and transfer technique has been developed. The aim of this study was to optimize the CBCT scanning protocol to achieve a dose as low as possible and to maintain sufficient image quality.A sectional head phantom (SK150; The Phantom Laboratory, Salem, NY) was scanned using 18 exposure protocols in 3 different CBCT machines: 3D Accuitomo 170 (Morita, Kyoto, Japan), ProMax 3D MAX (Planmeca, Helsinki, Finland), and NewTom VGI EVO (QR Verona, Verona, Italy). The effective dose (ED) was calculated using Monte Carlo simulation and pediatric voxel phantoms (5- and 8-year-old males and a 12-year-old female). Image quality was assessed by comparing segmented teeth volumes, evaluation of the visibility of the lamina dura, and morphologic surface analysis of 3-dimensional models. A general linear mixed model was fit to combine image quality parameters and radiation effective dose for each protocol in order to rank and compare the protocols examined in the study.The ED for the preoperative scan can be reduced to the range of 74.6-157.9 μSv, with ProMax with ultra-low-dose high-definition reconstruction (Planmeca) 100 × 90 scoring the highest. The ED for the postoperative scan can be reduced to the range of 24.2-41.5 μSv with ProMax with ultra-low-dose normal-dose reconstruction 50 × 55 and NewTom 50 × 50 with the standard mode scoring the highest.A considerable reduction in the pediatric ED can be achieved while maintaining sufficient image quality for tooth autotransplantation planning and follow-up using the dose optimization protocols.
View details for DOI 10.1016/j.joen.2016.10.022
View details for Web of Science ID 000394484400007
View details for PubMedID 28027823
Multi-segmental movements as a function of experience in karate
JOURNAL OF SPORTS SCIENCES
2017; 35 (15): 1515–22
Karate is a martial art that partly depends on subjective scoring of complex movements. Principal component analysis (PCA)-based methods can identify the fundamental synergies (principal movements) of motor system, providing a quantitative global analysis of technique. In this study, we aimed at describing the fundamental multi-joint synergies of a karate performance, under the hypothesis that the latter are skilldependent; estimate karateka's experience level, expressed as years of practice. A motion capture system recorded traditional karate techniques of 10 professional and amateur karateka. At any time point, the 3D-coordinates of body markers produced posture vectors that were normalised, concatenated from all karateka and submitted to a first PCA. Five principal movements described both gross movement synergies and individual differences. A second PCA followed by linear regression estimated the years of practice using principal movements (eigenpostures and weighting curves) and centre of mass kinematics (error: 3.71 years; R2 = 0.91, P ≪ 0.001). Principal movements and eigenpostures varied among different karateka and as functions of experience. This approach provides a framework to develop visual tools for the analysis of motor synergies in karate, allowing to detect the multi-joint motor patterns that should be restored after an injury, or to be specifically trained to increase performance.
View details for DOI 10.1080/02640414.2016.1223332
View details for Web of Science ID 000400988300006
View details for PubMedID 27560105
Facial thirds-based evaluation of facial asymmetry using stereophotogrammetric devices: Application to facial palsy subjects
JOURNAL OF CRANIO-MAXILLOFACIAL SURGERY
2017; 45 (1): 76–81
Many conditions can compromise facial symmetry, resulting in an impairment of the affected person from both esthetic and functional points of view. For these reasons, a detailed, focused, and objective evaluation of facial asymmetry is needed, both for surgical planning and for treatment evaluation. In this study, we present a new quantitative method to assess symmetry in different facial thirds, objectively defined on the territories of distribution of trigeminal branches. A total of 70 subjects (40 healthy controls and 30 patients with unilateral facial palsy) participated. A stereophotogrammetric system and the level of asymmetry of the subjects' hemi-facial thirds was evaluated, comparing the root mean square of the distances (RMSD) between their original and mirrored facial surfaces. Results show a high average reproducibility of area selection (98.8%) and significant differences in RMSD values between controls and patients (p = 0.000) for all of the facial thirds. No significant differences were found on different thirds among controls (p > 0.05), whereas significant differences were found for the upper, middle, and lower thirds of patients (p = 0.000). The presented method provides an accurate, reproducible, and local facial symmetry analysis that can be used for different conditions, especially when only part of the face is asymmetric.
View details for DOI 10.1016/j.jcms.2016.11.003
View details for Web of Science ID 000392686800012
View details for PubMedID 27939040
Facial Evaluation in Holoprosencephaly
JOURNAL OF CRANIOFACIAL SURGERY
2017; 28 (1): E22–E28
Holoprosencephaly (HPE) is a malformation of the brain, occurring during the first weeks of pregnancy, that may be associated with several craniofacial alterations and different pathological conditions.The authors describe a 2-year-old girl with lobar HPE, epilepsy, but with a roughly normal face. Despite the macroscopic, clinical appearance, a facial morphometric analysis, performed through a stereophotogrammetric system, showed features that diverge from reference subjects and that are considered typical of HPE.This study highlights how a digital anthropometric facial assessment through stereophotogrammetry can be a useful and noninvasive instrument to investigate the facial features of HPE, especially in the presence of an apparently normal facial aspect. Additionally, it can provide the bases for future insights about the relationship between embryological facial and cerebral development, the time of the occurred defect and, in the end, enrich basic scientific knowledge.
View details for DOI 10.1097/SCS.0000000000003171
View details for Web of Science ID 000392299200086
View details for PubMedID 27875510
Computer-aided cephalometric landmark annotation for CBCT data
INTERNATIONAL JOURNAL OF COMPUTER ASSISTED RADIOLOGY AND SURGERY
2017; 12 (1): 113–21
Nowadays, with the increased diffusion of Cone Beam Computerized Tomography (CBCT) scanners in dental and maxillo-facial practice, 3D cephalometric analysis is emerging. Maxillofacial surgeons and dentists make wide use of cephalometric analysis in diagnosis, surgery and treatment planning. Accuracy and repeatability of the manual approach, the most common approach in clinical practice, are limited by intra- and inter-subject variability in landmark identification. So, we propose a computer-aided landmark annotation approach that estimates the three-dimensional (3D) positions of 21 selected landmarks.The procedure involves an adaptive cluster-based segmentation of bone tissues followed by an intensity-based registration of an annotated reference volume onto a patient Cone Beam CT (CBCT) head volume. The outcomes of the annotation process are presented to the clinician as a 3D surface of the patient skull with the estimate landmark displayed on it. Moreover, each landmark is centered into a spherical confidence region that can help the clinician in a subsequent manual refinement of the annotation. The algorithm was validated onto 18 CBCT images.Automatic segmentation shows a high accuracy level with no significant difference between automatically and manually determined threshold values. The overall median value of the localization error was equal to 1.99 mm with an interquartile range (IQR) of 1.22-2.89 mm.The obtained results are promising, segmentation was proved to be very robust and the achieved accuracy level in landmark annotation was acceptable for most of landmarks and comparable with other available methods.
View details for DOI 10.1007/s11548-016-1453-9
View details for Web of Science ID 000392144300011
View details for PubMedID 27358080
Validation of a technique for integration of a digital dental model into stereophotogrammetric images of the face using cone-beam computed tomographic data
BRITISH JOURNAL OF ORAL & MAXILLOFACIAL SURGERY
2016; 54 (5): 584–86
We wanted to find and validate a new way to visualise patients' faces and their dental arches non-invasively. The stereophotogrammetric images of the faces and the digitised dental casts of seven healthy subjects were analysed. Point-based and surface-based recording techniques matched the facial image with those of the mandibular and maxillary dental arches in their relative positions. The cone-beam computed tomographic (CT) images of the same subjects were analysed retrospectively. Twenty-eight dentofacial distances were obtained on cone-beam CT images and on the recorded facial and dental surfaces. The median (IQR) distances of more than 96% of the measurements did not differ significantly.
View details for DOI 10.1016/j.bjoms.2016.01.019
View details for Web of Science ID 000377303500023
View details for PubMedID 26852270
The nasal septum deviation index (NSDI) based on CBCT data
2016; 45 (2): 20150327
To assess whether three-dimensional morphometric parameters could be useful in nasal septal deviation (NSD) diagnosis and, secondarily, whether CBCT could be considered an adequate imaging technique for the proposed task.We analysed images of 46 subjects who underwent CBCT for reasons not related to this study. Two experienced operators divided all the images into healthy and NSD subjects. Subsequently, the images were segmented using ITK Snap in order to obtain the three-dimensional model of the nasal airways and compute four morphological parameters: septal deviation angle (SDA), percentage of volume difference between right and left side of the nasal airways, nasal airway total volume and a new synthetic septal deviation index (SDI). Principal component analysis (PCA) was used to unveil relationships between each variable and the global nasal airway variability.Differences between the groups were found in SDA (p < 0.001), in volume percentage difference (p < 0.05) and in SDI (p < 0.001). PCA showed high correlation between the SDI and the first principal component (0.97, p < 0.001).Among the analysed parameters, SDI seemed to be the most suitable for the quantitative assessment of NSD, and CBCT allowed accurate assessment of airway morphology.
View details for DOI 10.1259/dmfr.20150327
View details for Web of Science ID 000370397400007
View details for PubMedID 26783044
View details for PubMedCentralID PMC5083957
Age-related and sex-related changes in the normal soft tissue profile of native Northern Sudanese subjects: a cross-sectional study
BRITISH JOURNAL OF ORAL & MAXILLOFACIAL SURGERY
2016; 54 (2): 192–97
Information about age-related and sex-related normative measurements of the nasolabial region in native Northern Sudanese subjects is scanty. We have therefore used a hand-held laser scanner to measure nasolabial angles and distances, and collected the 3-dimensional coordinates of seven landmarks on the facial soft tissues from 654 healthy native Northern Sudanese subjects (327 male and 327 female, aged 4-30 years). From these we calculated five angles and two linear distances and took the mean (SD) for age and sex, and compared them using factorial analysis of variance. All measurements analysed were significantly modified by age in both sexes (p < 0.01) except for the distance from the lower lip to Ricketts' E-line. Sex had a significant effect on the mentolabial and maxillary prominence angles and both distances (p < 0.005). Nasal convexity and the interlabial angle became more obtuse with growth, while the nasolabial and mentolabial angles reduced progressively with female subjects having significantly more obtuse mentolabial angles (p < 0.001). The maxillary prominence angle progressively decreased during childhood, and increased after adolescence, with larger values in male subjects. The upper and lower lip distances from Ricketts' E-line were also significantly larger in male subjects (p < 0.003), but the difference reduced with age. Overall, there were several differences when we compared our data with published data for African and white subjects, which points to the need for ethnic-specific data. Measurements collected in the current study could be used for the quantitative description of facial morphology in native Northern Sudanese children, adolescents, and young adults.
View details for DOI 10.1016/j.bjoms.2015.11.015
View details for Web of Science ID 000369692800019
View details for PubMedID 26689636
Implant-Supported Immediately Loaded Full-Arch Rehabilitations: Comparison of Resin and Zirconia Clinical Outcomes in a 5-Year Retrospective Follow-Up Study
2016; 25 (1): 74–82
We analyzed complications and failures of final full-arch implant-supported rehabilitations, comparing resin and zirconia prosthesis materials. Prostheses were retrospectively followed up for 5 years.One hundred twenty-five patients who received one or two four to six implant-supported immediately loaded full-arch rehabilitations in resin (166 prostheses) or zirconia (48 prostheses) were analyzed.One hundred thirteen patients (53 men, 60 women), with 214 full-arch prostheses (105 maxillary, 109 mandibular), were analyzed. During the follow-up interval, the prosthesis annual complication rate was 6.6%, free complications survival was 75.5% (60 months). Age, number of implants, and prosthesis material did not influence complication risk. Men had a higher risk of complications than women. Prosthesis annual failure rate was 4.6%, free survival was 85.5% (60 months). Age, number of implants, and prosthesis material did not influence failure risk. Men and maxillary arch prostheses had a higher risk of failures than women and mandibular arch prostheses.Implant-supported, immediately loaded full-arch rehabilitations supporting resin or zirconia based prostheses were clinically successful in a 5-year follow-up. Prosthesis material did not influence complication risk.
View details for DOI 10.1097/ID.0000000000000368
View details for Web of Science ID 000377141700010
View details for PubMedID 26655096
- A Quantitative Analysis of Lip Aesthetics: The Influence of Gender and Aging (vol 39, pg 771, 2015) AESTHETIC PLASTIC SURGERY 2015; 39 (5): 777
A Quantitative Analysis of Lip Aesthetics: The Influence of Gender and Aging
AESTHETIC PLASTIC SURGERY
2015; 39 (5): 771–76
The quantitative analysis of sexual dimorphism of facial structures may valuably support reconstructive and feminization surgery, thanks to the estimation of metrical thresholds useful for distinguishing male and female traits. This study aims at verifying the metrical characteristics of female and male lips, to provide indications for aesthetic surgery.Thirty healthy Caucasian volunteers (20 men and 20 women) were divided into two groups according to age: 21-34 years and 45-65 years. Arches and the cutaneous (external) and mucosal (internal) labial surfaces were reproduced by stone models, and digitised using a computerised electromechanical instrument. Area, volume and thickness were measured separately for the upper and lower lips, and compared between sexes and ages by Student's t test, and multinomial logistic regression.All lip measurements were larger in males than in females; upper lip thickness best divided males from females, adopting a 9.5-mm threshold (percentage of correct diagnosis: 85 %). Young subjects always showed higher measurements than old subjects; lower lip thickness provided the highest percentage of correct age diagnosis (85 %, adopting a 13.8-mm threshold).This study provides novel thresholds that may contribute to the assessment of adequate reconstruction of lips in aesthetic surgery.This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
View details for DOI 10.1007/s00266-015-0495-7
View details for Web of Science ID 000360861800017
View details for PubMedID 25948067
The Labial Aging Process: A Surface Analysis-Based Three-Dimensional Evaluation
AESTHETIC PLASTIC SURGERY
2014; 38 (1): 236–41
With increasing age, the smile becomes elongated and less appealing. Currently, several methods are proposed for analysis of lip morphology including lateral cephalograms, profile and frontal photographs, video images, and three-dimensional systems. Despite several descriptions of morphologic and histologic age-related changes in the literature, no scientific well-supported model of the labial aging process is reported.For this study, 33 healthy volunteers were selected and divided into two groups according to age: a youthful group (ages 21-34 years) and an aged group (ages 45-65 years). Their dental and labial stone casts were obtained, digitized, and virtually reproduced using a computerized electromechanical digitizer and applying nonuniform rational B-spline geometry. To obtain a synthetic parameter describing local surface deformation, average curvature and curvature variability indexes were computed and compared.No significant age- or sex-related differences in the average curvature were detected. In contrast, the curvature variability was significantly greater in the young than in the aged subjects.The labial arch surface remains macroscopically constant between the third and the sixth decades of life, but with local modifications that influence the standard deviation of its curvature. A high standard deviation described the protruding labial appearance of the young subjects, whereas a reduced one described the flat lips of the aged subjects.This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
View details for DOI 10.1007/s00266-013-0227-9
View details for Web of Science ID 000331984400040
View details for PubMedID 24142116