The Usefullness of Subclavian Artery Ultrasound Assessment in Giant Cell Arteritis Evaluation.

OBJECTIVE: Vascular ultrasound has been increasingly used to diagnose giant cell arteritis (GCA). The temporal and axillary arteries are commonly evaluated. However, the usefulness of including the subclavian artery remains unclear. This study investigated whether inclusion of the subclavian artery in addition to the temporal and axillary arteries in the ultrasound evaluation of GCA improves the accuracy of the examination beyond ultrasonography of the temporal and axillary arteries alone. METHODS: We formed a fast-track clinic to use ultrasound to rapidly evaluate patients with suspected GCA. In this cohort study, patients referred for new concern for GCA received a vascular ultrasound for GCA. Subclavian intima-media thickness (IMT) cutoffs of 1.0 and 1.5 mm were retrospectively assessed. RESULTS: Two hundred thirty-seven patients were referred to the fast-track clinic from November 2017 to August 2021. One hundred sixty-eight patients received an ultrasound for concern for new GCA. With a subclavian IMT cutoff of 1.5 mm, inclusion of the subclavian artery did not identify any patients with GCA who were not otherwise found to have positive temporal and/or axillary artery examinations, and at this cutoff, there was 1 false-positive result. A subclavian IMT cutoff of 1.0 mm identified several subjects diagnosed with GCA who had otherwise negative ultrasounds, but most subjects with an isolated subclavian IMT greater than 1.0 mm had false-positive results, and the specificity of this cutoff was poor. CONCLUSION: Inclusion of the subclavian artery in the ultrasound assessment of GCA at 2 different cutoffs rarely contributed to the accurate diagnosis of GCA and increased the rate of false-positive results.

Formative Assessment of Performance in Diagnostic Ultrasound Using Simulation and Quantitative and Objective Metrics.

BACKGROUND: We developed simulator-based tools for assessing provider competence in transthoracic echocardiography (TTE) and vascular duplex scanning. METHODS: Psychomotor (technical) skill in TTE image acquisition was calculated from the deviation angle of an acquired image from the anatomically correct view. We applied this metric for formative assessment to give feedback to learners and evaluate curricula.Psychomotor skill in vascular ultrasound was measured in terms of dexterity and image plane location; cognitive skill was assessed from measurements of blood flow velocity, parameter settings, and diagnosis. The validity of the vascular simulator was assessed from the accuracy with which experts can measure peak systolic blood flow velocity (PSV). RESULTS: In the TTE simulator, the skill metric enabled immediate feedback, formative assessment of curriculum efficacy, and comparison of curriculum outcomes. The vascular duplex ultrasound simulator also provided feedback, and experts' measurements of PSV deviated from actual PSV in the model by <10%. CONCLUSIONS: Skill in acquiring diagnostic ultrasound images of organs and vessels can be measured using simulation in an objective, quantitative, and standardized manner. Current applications are provision of feedback to learners to enable training without direct faculty oversight and formative assessment of curricula. Simulator-based metrics could also be applied for summative assessment.

Simulation for competency assessment in vascular and cardiac ultrasound.

Healthcare providers who use peripheral vascular and cardiac ultrasound require specialized training to develop the technical and interpretive skills necessary to perform accurate diagnostic tests. Assessment of competence is a critical component of training that documents a learner's progress and is a requirement for competency-based medical education (CBME) as well as specialty certification or credentialing. The use of simulation for CBME in diagnostic ultrasound is particularly appealing since it incorporates both the psychomotor and cognitive domains while eliminating dependency on the availability of live patients with a range of pathology. However, successful application of simulation in this setting requires realistic, full-featured simulators and appropriate standardized metrics for competency testing. The principal diagnostic parameter in peripheral vascular ultrasound is measurement of peak systolic velocity (PSV) on Doppler spectral waveforms, and simulation of Doppler flow detection presents unique challenges. The computer-based duplex ultrasound simulator developed at the University of Washington uses computational fluid dynamics modeling and presents real-time color-flow Doppler images and Doppler spectral waveforms along with the corresponding B-mode images. This simulator provides a realistic scanning experience that includes measuring PSV in various arterial segments and applying actual diagnostic criteria. Simulators for echocardiography have been available since the 1990s and are currently more advanced than those for peripheral vascular ultrasound. Echocardiography simulators are now offered for both transesophageal echo and transthoracic echo. These computer-based simulators have 3D graphic displays that provide feedback to the learner and metrics for assessment of technical skill that are based on transducer tracking data. Such metrics provide a motion-based or kinematic analysis of skill in performing cardiac ultrasound. The use of simulation in peripheral vascular and cardiac ultrasound can provide a standardized and readily available method for training and competency assessment.