Academic Appointments

  • Clinical Instructor, Radiology


All Publications

  • What is the added sensitivity of non-lateral cervical spine radiographs in the evaluation of acute cervical spine trauma? Emergency radiology Haas, B. M., Hahn, L. D., Oliva, I. 2018


    PURPOSE: Plain radiography of the cervical spine is used as a screening test for trauma patients. We evaluated the diagnostic yield of performing anteroposterior (AP), odontoid, and oblique views in addition to the lateral view in the current era when radiographs are performed only on low-risk patients.METHODS: All imaging reports from cervical spine radiography studies on patients aged 18years and older in the emergency room of a major academic medical center between November 22, 2003, and January 17, 2012, were retrospectively reviewed. For the clinical workflow employed at the time of study acquisition, radiologists prospectively reviewed the lateral projection and subsequently reviewed the entirety of the images obtained. Exam reports and, when necessary, images were reviewed to determine which patients had fractures and on which projection the fractures were identified.RESULTS: Six fractures were detected in 7218 exams. Three of these fractures were identified on the lateral radiograph, and three of these fractures were visualized on the additional projections (two on oblique and one on odontoid views). The yield of the additional projections is one fracture per 9713 radiographic projections (90% confidence interval of one fracture per 1245-47,946 examinations). For two of the patients with fractures identified on the lateral projection, an additional fracture was seen when CT was then performed.CONCLUSIONS: Performing additional radiographs of the cervical spine including AP, odontoid, and bilateral oblique projections in trauma patients with low pretest probability of fracture augments the diagnostic yield of lateral radiographs. Considering the potential for devastating neurological outcomes from missed cervical fractures, addition of AP, odontoid, and oblique projections continues to detect fractures at a low rate.

    View details for PubMedID 30386948

  • Cross-sectional imaging of thoracic traumatic aortic injury. VASA. Zeitschrift fur Gefasskrankheiten Hahn, L. D., Prabhakar, A. M., Zucker, E. J. 2018: 1?12


    Aortic injury remains a major contributor to morbidity and mortality from acute thoracic trauma. While such injuries were once nearly uniformly fatal, the advent of cross-sectional imaging in recent years has facilitated rapid diagnosis and triage, greatly improving outcomes. In fact, cross-sectional imaging is now the diagnostic test of choice for traumatic aortic injury (TAI), specifically computed tomography angiography (CTA) in the acute setting and CTA or magnetic resonance angiography (MRA) in follow-up. In this review, we present an up-to-date discussion of acute traumatic thoracic aortic injury with a focus on optimal and emerging CT/MR techniques, imaging findings of TAI, and potential pitfalls.

    View details for PubMedID 30264668

  • Improving Quality of Dynamic Airway Computed Tomography Using an Expiratory Airflow Indicator Device. Journal of thoracic imaging Hahn, L. D., Sung, A. W., Shafiq, M., Guo, H. H. 2018


    Dynamic computed tomography (CT) of the airways is increasingly used to evaluate patients with suspected expiratory central airway collapse, but current protocols are susceptible to inadequate exhalation caused by variable patient compliance with breathing instructions during the expiratory phase. We developed and tested a low-cost single-use expiratory airflow indicator device that was designed to improve study quality by providing a visual indicator to both patient and operator when adequate expiratory flow was attained.A total of 56 patients undergoing dynamic airway CT were evaluated, 35 of whom were scanned before introduction of the indicator device (control group), with the rest comprising the intervention group. Lung volumes and tracheal cross-sectional areas on inspiratory/expiratory phases were computed using automated lung segmentation and quantitative software analysis. Inadequate exhalation was defined as absolute volume change of <500?mL during the expiratory phase.Fewer patients in the intervention group demonstrated inadequate exhalation. The average change in volume was higher in the intervention group (P=0.004), whereas the average minimum tracheal cross-sectional area was lower (P=0.01).The described expiratory airflow indicator device can be used to ensure adequate exhalation during the expiratory phase of dynamic airway CT. A higher frequency of adequate exhalation may improve reliability and sensitivity of dynamic airway CT for diagnosis of expiratory central airway collapse.

    View details for PubMedID 29470258

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