Stanford University, BS 2010
Brown University, MD 2015
Scripps Transitional Year, Intern
University of California San Diego, Residency

Clinical Focus

  • Diagnostic Radiology

Academic Appointments

  • Clinical Assistant Professor, Radiology

Professional Education

  • Internship: Scripps Mercy Hospital San Diego (2016) CA
  • Board Certification: American Board of Radiology, Diagnostic Radiology (2021)
  • Fellowship: Stanford University Body Imaging Fellowship (2021) CA
  • Residency: UCSD Radiology Residency (2020) CA
  • Medical Education: Brown University School of Medicine (2015) RI

All Publications

  • Predictive value and prevalence of refractive edge shadow in diagnosis of ovarian dermoids. Abdominal radiology (New York) Shen, L., Tse, J. R., Negrete, L. M., Lo, E., Yoon, L., Kamaya, A. 2022


    To evaluate the diagnostic performance of refractive edge shadow in evaluation of ovarian dermoids compared to other benign adnexal masses.Ultrasound images of 139 patients with 154 dermoids, endometriomas, and hemorrhagic cysts were retrospectively reviewed by 3 radiologists blinded to final diagnosis. Ultrasound and clinical features were compared to pathology or follow-up ultrasound results as reference standard. Inter-reader agreements with free-marginal kappa and diagnostic performance were evaluated. The former was compared using Fisher's exact test or Mann-Whitney test with p < 0.05 to determine statistical significance.The study sample consisted of 154 lesions: 50 dermoids, 50 endometriomas, and 54 hemorrhagic cysts. Refractive edge shadow, homogeneous echogenic appearance, tip of the iceberg sign, mural echogenic nodule, echogenic shadowing focus, and dot-dash sign all were statistically significant across all readers for the diagnosis of dermoid. Prevalence of each feature in dermoids compared to other entities were as follows: refractive edge shadow (70% vs 8%; p < 0.001), homogeneously echogenic appearance (34% vs 2%; p < 0.001), tip of the iceberg sign (16% vs 1%; p < 0.001), mural echogenic nodule (38% vs 2%; p < 0.001), echogenic shadowing focus (13% vs 1%; p < 0.001), and dot-dash sign (44% vs 1%; p < 0.001). Refractive edge shadow had the highest sensitivity, negative predictive value, and accuracy among all ultrasound features associated with dermoids (70%, 86%, and 85%, respectively).Refractive edge shadow is a promising ultrasound feature for diagnosis of dermoids, with the highest diagnostic accuracy and prevalence compared to other previously described features associated with dermoids.

    View details for DOI 10.1007/s00261-022-03666-3

    View details for PubMedID 36098759

  • Clinical and ultrasound features of dermoid-associated adnexal torsion. Abdominal radiology (New York) Shen, L., Tse, J. R., Negrete, L. M., Flory, M. N., Yoon, L., Kamaya, A. 2022


    To determine the clinical and ultrasound features of dermoid-associated adnexal torsion.Forty-four patients with at least one dermoid and ultrasound ≤ 30 days of surgery were retrospectively reviewed by three radiologists. Ultrasound and clinical findings were compared to intra-operative findings using Fisher's exact test or Mann-Whitney test with p < 0.05 to determine statistical significance.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.Correct. No edit RESULTS: Twenty patients had torsion, while 24 patients did not. Patients with dermoid-associated torsion were more likely to present to emergency department (ED) (100% vs 13%; p < 0.001) and have acute unilateral pelvic pain (100% vs 42%; p < 0.001). On ultrasound, patients with torsion had larger dermoids (median largest dimension 9.0 cm (IQR 7.7-11.1) vs 6.0 cm (IQR 4.4-7.5); p < 0.001), displaced dermoid anterior or superior to the uterus (59% vs 21%; p = 0.016), and ipsilateral adnexal fluid (41% vs 4%; p = 0.003). Displaced dermoid and ipsilateral adnexal fluid had substantial (kappa = 0.72) and moderate inter-rater agreement (kappa = 0.49), respectively. The combination of ED presentation and each statistically significant ultrasound feature (dermoid size ≥ 5.0 cm, displaced dermoid, and ipsilateral adnexal fluid) yielded high specificity and positive predictive value (ranging from 93-100% to 92-100%, respectively). The combination of ED presentation and dermoid size ≥ 5.0 cm yielded the highest sensitivity, negative predicative value, and accuracy (100%, 100%, and 96%, respectively).Please check and confirm whether the edit made to the article title is in order.Looks great. No edits. Thank you!Although the diagnosis of adnexal torsion in the presence of an ovarian dermoid is traditionally challenging, the combination of ED presentation and ultrasound features increase diagnostic confidence of dermoid-associated adnexal torsion.

    View details for DOI 10.1007/s00261-022-03601-6

    View details for PubMedID 35809127

  • Jumping to conclusions: Misdiagnosing radiation induced sarcoma as recurrent breast cancer. Clinical imaging Chughtai, K., Negrete, L., Vitzthum, L. K. 2022; 84: 110-112


    Radiation therapy (RT) induced chondrosarcoma is a rare but important potential complication seen in cancer patients treated with radiation. Although uncommon, these patients tend to have a poor prognosis, so early detection and complete resection are the crucial steps towards survival. We present the case of an 81-year-old breast cancer patient who was treated with RT to the left chest wall. Eight years later, she presented with a growing left chest wall mass, initially thought to represent local breast cancer recurrence. Imaging demonstrated a well-defined mass arising from the left pectoralis major muscle. The mass was excised, and pathology demonstrated chondrosarcoma. We discuss the clinical and radiologic aspects of RT-induced sarcomas with attention to the very rare chondrosarcoma. The aim of this report is to provide a succinct but relevant summary of the diagnostic considerations for RT-induced sarcoma supported by information about epidemiology, clinical diagnostic criteria, and radiation biology to expedite patient workup and ultimately improve patient outcomes.

    View details for DOI 10.1016/j.clinimag.2022.01.014

    View details for PubMedID 35176572

  • Progression Versus Radiation Treatment Changes After Stereotactic Ablative Radiation Therapy of a Liver Metastasis PRACTICAL RADIATION ONCOLOGY No, H. J., Negrete, L. M., Pollom, E. L., Wakelee, H. A., Chang, D. T., Vitzthum, L. K. 2022; 12 (1): 1-2
  • Inflammatory pseudotumor-like follicular dendritic cell tumor of the spleen: a case report and approach to differential diagnosis. Radiology case reports Nguyen, A., Negrete, L. M., Bulterys, P. L., Shen, L. 2021; 16 (11): 3213-3216


    We present a case of an inflammatory pseudotumor-like follicular dendritic cell tumor of the spleen. The patient is a 44-year-old woman, without significant underlying history, who presented with nonspecific abdominal pain for a few months. Both a contrast enhanced computed tomography and magnetic resonance imaging revealed a new 2.5 cm enhancing splenic lesion, which demonstrated hypermetabolic activity on subsequent positron emission tomography and computed tomography scan. Since the lesion was new compared to more remote imaging and hypermetabolic, a splenectomy was performed. Pathology confirmed the diagnosis and demonstrated positivity for Epstein-Barr Virus .

    View details for DOI 10.1016/j.radcr.2021.07.078

    View details for PubMedID 34484521