Introducing point-of-care ultrasound through structured multifaceted ultrasound module in the undergraduate medical curriculum at the University of Hong Kong.

Incorporation of point-of-care ultrasound in the undergraduate medical curriculum is of great importance to ensure early exposure and safe use of the modality. We aimed to assess the students' learning experiences following implementing an ultrasound module in the medical curriculum at the University of Hong Kong. Medical students in semester 6 (n = 221) were enrolled in the module in 2018. It consisted of 1 hour of didactic lecture, followed by 3 hours of hands-on session. The students had the opportunity to enroll into a four-week Special Study Module to further practice their skills. The students had access to an e-learning platform to assist in their learning. Outcome measures include task-based performance, quizzes, feedback, and round-table discussion to assess the learning experiences. The module was highly rated by over 90% of students (response rate of 96%). Students practiced on peer subject on upper abdominal scanning. Post-training assessment showed an increment of 16% in their understanding of the modality. Students were motivated to enroll into the Special Study Module, where they were trained and became proficient with Focused Assessment with Sonography with Trauma. More than 86% of the students found the e-learning platform easy to use and assisted the training session. Round-table discussion suggested more simulated clinical cases to be added and expansion of future modules. Ultrasound module was successfully implemented into the undergraduate medical curriculum at the University of Hong Kong through new pedagogical approaches. This integration was highly rated by the medical students with improved awareness and better understanding of point-of-care ultrasound.

Toward a Standardization of Ultrasound Scanners for Dynamic Contrast-Enhanced Ultrasonography: Methodology and Phantoms.

The standardization of ultrasound scanners for dynamic contrast-enhanced ultrasonography (DCE-US) is mandatory for evaluation of clinical multicenter studies. We propose a robust method using a phantom for measuring the variation of the harmonic signal intensity obtained from the area under the time-intensity curve versus various contrast-agent concentrations. The slope of this measured curve is the calibration parameter. We tested our method on two devices from the same manufacturer (AplioXV and Aplio500, Toshiba, Tokyo, Japan) using the same settings as defined for a French multicenter study. The Aplio500's settings were adjusted to match the slopes of the AplioXV, resulting in the following settings on the Aplio500: at 3.5 MHz: MI = 0.15; CG = 35 dB and at 8 MHz: MI = 0.10; CG = 32 dB. This calibration method is very important for future DCE-US multicenter studies.

Study of Intrapatient Variability and Reproducibility of Quantitative Tumor Perfusion Parameters Evaluated With Dynamic Contrast-Enhanced Ultrasonography.

OBJECTIVES: Dynamic contrast-enhanced (DCE) ultrasonography (US) is a functional imaging technique enabling quantitative assessment of solid tumor perfusion in metastatic patients treated with antiangiogenic therapies.The objective of this prospective single-center study was to evaluate in real-life conditions (in routine clinical practice) the intrapatient variability and reproducibility of DCE-US parameters. MATERIALS AND METHODS: Each patient provided written informed consent and had 2 DCE-US examinations (preprandial and postprandial) at baseline, day 15, and 1 month after treatment initiation. Perfusion curves were recorded after Sonovue injections to determine 7 perfusion parameters. Dynamic contrast-enhanced US examinations were analyzed in pairs: preprandial and postprandial. Log transformed values were used to determine the variability of the pairs (within-subject coefficient of variation) and their reproducibility (Spearman correlation coefficient). RESULTS: We included 60 patients (23 colon cancers, 36 kidney cancers, and 1 breast cancer) treated with axitinib (26 patients), sunitinib (27 patients), and other antiangiogenic treatments (7 patients). The 60 patients included 38 men (63%) and 22 women (37%) with a median age of 62 (range, 25-82 years). Thirty patients had hepatic and 30 had extrahepatic target lesions. Data were analyzed for 128 pairs of DCE-US: 45 (baseline), 45 (day 15), and 38 (1 month). Preprandial and postprandial values were not significantly different. For area under the curve and area under the washout, the correlation coefficient between preprandial and postprandial values was 0.89; the associated within-subject coefficients of variation were 61% and 64%, respectively. However, the range of individual variations (postprandial value/preprandial value) was less than 2 logs for a range of parameter values of about 4 logs. Variability was independent of the metastatic site. CONCLUSIONS: This study showed that area under the curve and area under the washout are the 2 most reproducible DCE-US parameters.

Validation of dynamic contrast-enhanced ultrasound in predicting outcomes of antiangiogenic therapy for solid tumors: the French multicenter support for innovative and expensive techniques study.

OBJECTIVES: Dynamic contrast-enhanced ultrasound (DCE-US) has been used in single-center studies to evaluate tumor response to antiangiogenic treatments: the change of area under the perfusion curve (AUC), a criterion linked to blood volume, was consistently correlated with the Response Evaluation Criteria in Solid Tumors response. The main objective here was to do a multicentric validation of the use of DCE-US to evaluate tumor response in different solid tumor types treated by several antiangiogenic agents. A secondary objective was to evaluate the costs of the procedure. MATERIALS AND METHODS: This prospective study included patients from 2007 to 2010 in 19 centers (8 teaching hospitals and 11 comprehensive cancer centers). All patients treated with antiangiogenic therapy were eligible. Dynamic contrast-enhanced ultrasound examinations were performed at baseline as well as on days 7, 15, 30, and 60. For each examination, a perfusion curve was recorded during 3 minutes after injection of a contrast agent. Change from baseline at each time point was estimated for each of 7 fitted criteria. The main end point was freedom from progression (FFP). Criterion/time-point combinations with the strongest correlation with FFP were analyzed further to estimate an optimal cutoff point. RESULTS: A total of 1968 DCE-US examinations in 539 patients were analyzed. The median follow-up was 1.65 years. Variations from baseline were significant at day 30 for several criteria, with AUC having the most significant association with FFP (P = 0.00002). Patients with a greater than 40% decrease in AUC at day 30 had better FFP (P = 0.005) and overall survival (P = 0.05). The mean cost of each DCE-US was 180&OV0556;, which corresponds to $250 using the current exchange rate. CONCLUSIONS: Dynamic contrast-enhanced ultrasound is a new functional imaging technique that provides a validated criterion, namely, the change of AUC from baseline to day 30, which is predictive of tumor progression in a large multicenter cohort. Because of its low cost, it should be considered in the routine evaluation of solid tumors treated with antiangiogenic therapy.