Teaching medical students ultrasound to measure liver size: comparison with experienced clinicians using physical examination alone.

Background: Ultrasound is increasingly recognized as a valuable addition to medical school curriculum. Purpose: In this study, we tested the ability of rising second year students to learn and conduct an ultrasound examination of vertical liver span at the point of care. Methods: Six patients from a GI clinic volunteered to have their liver size measured. Ten students were trained to measure vertical liver span with ultrasound. Four physicians were recruited to measure liver span with standard methods. Student and physician measurements were compared to each other and to a reference ultrasound measurement for accuracy and variability. Results: Compared to the reference, students overestimated liver size an average of 1.5 cm. Physicians underestimated liver size an average of 6.7 cm. Variance in student measurements for each patient was 10% to 17% and among physicians 20% to 50%. Conclusion: With limited instruction and clinical experience medical students can obtain liver size measurements with ultrasound that are more accurate and have less variability than those by physicians using physical examination. Given the ease with which students can learn to use ultrasound and the teaching and clinical value of ultrasound, ultrasound should be considered as a standard of medical education in the future.