Lotfi Hacein-Bey

All Publications

• Cultural bias in large language models' ability to follow neuroradiology guidelines. European radiology Bazerbachi, N., Bentegeac, R., Pistilli, G., Kim, S., Amouyel, P., Pruvo, J., Hacein-Bey, L., Hamroun, A., Kuchcinski, G., Le Guellec, B. 2026

  Abstract

  OBJECTIVES: Large language models (LLMs) are increasingly explored as decision-support tools in medical imaging. However, their ability to align with country-specific guidelines, which often diverge, remains uncertain. We set out to evaluate the geographic neutrality of three state-of-the-art LLMs-GPT-o3, Mistral Large, and DeepSeek R1-and a biomedical LLM (MedGemma 1.5 4B), when applied to neuroradiology scenarios with conflicting U.S. and non-U.S.RECOMMENDATIONS:MATERIALS AND METHODS: Vignettes derived from contradictory international guidelines were presented to each model under two conditions: an implicit setting, where no guideline was specified and vignettes were provided in English and French; and an explicit setting, where prompts directed models to follow a named guideline. Performance was reviewed against the target guideline, and mitigation strategies were tested.RESULTS: Thirty clinical vignettes presenting conflicting guidelines were evaluated by GPT-o3, Mistral Large, and DeepSeek R1. In the implicit setting, all models favored U.S. guidelines, with GPT-o3, Mistral, and DeepSeek aligning with them in 27 of 30 scenarios (90.0%; 95% CI, 74.4-96.5). In the explicit setting, adherence declined sharply for non-U.S. recommendations for all models. Providing the complete guideline text was the most effective mitigation strategy, restoring accuracies above 90% across all models.CONCLUSION: Across languages and model origins, LLMs exhibited a systematic bias toward U.S. neuroradiology guidelines, even when explicitly instructed otherwise. This U.S.-centrism likely reflects training data imbalances and raises concerns for safe global deployment. Strategies for local contextualization, such as guideline integration at deployment, are necessary to ensure context-appropriate clinical decision support.KEY POINTS: Question Do large language models display geographical neutrality in neuroradiology decision support? Findings Even models developed in France and China systematically preferred United States guidelines, aligning with them in most implicit scenarios while failing to follow explicit guidelines from other sources. Clinical relevance This systematic United States-centric bias poses clinical and legal risks for global deployment. Safe implementation requires specific localization strategies, such as providing full guideline texts, to ensure recommendations align with local practice standards.

  View details for DOI 10.1007/s00330-026-12634-0

  View details for PubMedID 42189215

• MRI-Guided Focused Ultrasound: Establishing an Effective Innovative Paradigm to Treat Complex Neurologic Conditions. AJR. American journal of roentgenology Hacein-Bey, L. 2026

  View details for DOI 10.2214/AJR.26.35070

  View details for PubMedID 42018779

• Deep learning-based image reconstruction best contributes to image quality enhancement under close expert supervision. Diagnostic and interventional imaging Hacein-Bey, L. 2026

  View details for DOI 10.1016/j.diii.2025.12.006

  View details for PubMedID 41486036

• Actionable strategies to minimize diagnostic errors in radiology. The neuroradiology journal Ivanovic, V., Hacein-Bey, L., Chang, Y. M., Rawson, J. V. 2025: 19714009251395719

  Abstract

  Medical errors are a significant cause of morbidity and mortality. Literature on common mechanisms to reduce radiological error are reviewed including shifting from general to subspecialized care, improving expertise, instituting shift volume and shift length limits, minimizing non-interpretive tasks, participating in focused educational and multidisciplinary conferences, and increasing practice size. Implementation of shift volume limits and full sub-specialization has the potential to significantly reduce radiologist error rates.

  View details for DOI 10.1177/19714009251395719

  View details for PubMedID 41197112

  View details for PubMedCentralID PMC12592099

• Choroid plexus enlargement in idiopathic normal pressure hydrocephalus and concept proposal for noninvasive volume-reductive therapies. Brain research Dhawan, S. S., Hacein-Bey, L., Massoud, T. F. 2025: 149593

  Abstract

  Aberrant CSF dynamics in idiopathic normal pressure hydrocephalus (iNPH) are associated with excessive CSF volume and impaired resorption. Yet, the role of choroid plexus (CP) size in development and progression of iNPH remains unknown. Moreover, newer noninvasive CP-targeted volume-reductive treatments for iNPH might benefit selected vulnerable patients to avoid problematic long-term ventricular shunting. However, there are no studies to date that describe CP size in iNPH patients.We retrospectively studied brain 3T MRIs for 50 iNPH patients and 50 age and sex-matched healthy controls (HCs). We delineated areas and volumes of lateral ventricular CPs, then statistically compared both cohorts, with significance set at p < 0.05.In iNPH patients, CP volume (1.58-fold) alone, CP volume normalized to total intracranial volume (1.75-fold), and CP areas at four different locations and their combined values (1.24-fold) were highly significantly larger (p < 0.000) in iNPH patients.The novel finding of CP enlargement in iNPH should guide and support future investigations into potentially interrelated pathogenetic mechanisms. It also benefits considerations of new noninvasive targeted therapies (such as MR-guided high intensity focused ultrasound, and radiosurgery) to partially ablate CP and reduce its CSF secretion as a conceivable alternative to conventional ventricular shunting.

  View details for DOI 10.1016/j.brainres.2025.149593

  View details for PubMedID 40157411

• Dural Puncture Complications. Neuroimaging clinics of North America Geisbush, T. R., Matys, T., Massoud, T. F., Hacein-Bey, L. 2025; 35 (1): 53-76

  Abstract

  Dural puncture, commonly referred to as lumbar puncture (LP), carries the risk of rare but serious complications including post-dural puncture headache, hemorrhage, herniation, and infection. These complications can lead to suboptimal patient outcomes including significant morbidity and mortality in some instances. This review comprehensively examines potential LP complications, including their incidence, pathophysiology, risk factors, clinical presentations, imaging findings, preventative measures, and treatment strategies. Familiarity with these complications will equip clinicians to effectively manage these complications through prompt recognition, timely diagnosis, and implementation of appropriate preventative measures.

  View details for DOI 10.1016/j.nic.2024.08.015

  View details for PubMedID 39521527

• Root of the Neck and Extracranial Vessel Anatomy. Neuroimaging clinics of North America Raslan, O., Massoud, T. F., Hacein-Bey, L. 2022; 32 (4): 851-873

  Abstract

  The root of the neck is the junctional anatomic structure between the thoracic inlet, the axilla, and the lower neck. The detailed radiological anatomy of this critical area is discussed in this review.

  View details for DOI 10.1016/j.nic.2022.07.023

  View details for PubMedID 36244727

• Anatomy of Intracranial Veins. Neuroimaging clinics of North America Kubo, M., Kuwayama, N., Massoud, T. F., Hacein-Bey, L. 2022; 32 (3): 637-661

  Abstract

  The cerebral venous system is complex and sophisticated and serves various major functions toward maintaining brain homeostasis. Cerebral veins contain about 70% of cerebral blood volume, have thin walls, are valveless, and cross seamlessly white matter, ependymal, cisternal, arachnoid, and dural boundaries to eventually drain cerebral blood either into dural sinuses or deep cerebral veins. Although numerous variations in the cerebral venous anatomic arrangement may be encountered, the overall configuration is relatively predictable and landmarks relatively well defined. A reasonable understanding of cerebral vascular embryology is helpful to appreciate normal anatomy and variations that have clinical relevance. Increasing interest in transvascular therapy, particularly transvenous endovascular intervention provides justification for practitioners in the neurosciences to acquire at least a basic understanding of the cerebral venous system.

  View details for DOI 10.1016/j.nic.2022.05.002

  View details for PubMedID 35843667

• Neuro-Interventional Management of Acute Ischemic Stroke. Neuroimaging clinics of North America Hacein-Bey, L. n., Heit, J. J., Konstas, A. A. 2018; 28 (4): 625–38

  Abstract

  Restoration of cerebral blood flow is the most important step in preventing irreversible damage to hypoperfused brain cells after ischemic stroke from large-vessel occlusion. For those patients who do not respond to (or are not eligible for) intravenous thrombolysis, endovascular therapy has become standard of care. A shift is currently taking place from rigid time windows for intervention (time is brain) to physiology-driven paradigms that rely heavily on neuroimaging. At this time, one can reasonably anticipate that more patients will be treated, and that outcomes will keep improving. This article discusses in detail recent advances in endovascular stroke therapy.

  View details for DOI 10.1016/j.nic.2018.06.011

  View details for PubMedID 30322598

• Contemporary Imaging of Cerebral Arteriovenous Malformations. AJR. American journal of roentgenology Tranvinh, E., Heit, J. J., Hacein-Bey, L., Provenzale, J., Wintermark, M. 2017: 1-11

  Abstract

  Brain arteriovenous malformation (AVM) rupture results in substantial morbidity and mortality. The goal of AVM treatment is eradication of the AVM, but the risk of treatment must be weighed against the risk of future hemorrhage.Imaging plays a vital role by providing the information necessary for AVM management. Here, we discuss the background, natural history, clinical presentation, and imaging of AVMs. In addition, we explain advances in techniques for imaging AVMs.

  View details for DOI 10.2214/AJR.16.17306

  View details for PubMedID 28267351