松井 弘樹, 小池 弘人, 本岡 正彦, 藤田 晴康, 鈴木 忠, 横山 知行

Hiroki MATSUI, Hiroto KOIKE, Masahiko MOTOOKA, Haruyasu FUJITA, Tadashi SUZUKI, Tomoyuki YOKOYAMA

群馬大学医学部保健学科

Department of Health Sciences, Gunma University School of Medicine

キーワード : echocardiography, accuracy, reproducibility, training, curriculum

In echocardiography, the sonographer’s skill in acquiring images greatly influences the accuracy and reliability of the results. Yet, no standard training protocol for acquiring images has been established. Frequency, length of training, and methods of instruction, for example, have not been determined in the curriculum. To create a training protocol for mastering the basic skills of echocardiography, we examined the effects of training on beginners. Ten students from the Department of Health Sciences, Gunma University School of Medicine received 30 sessions of training in echocardiography over 12 weeks under the guidance of a professional ultrasonographer. Students measured the aortic dimension, left atrial dimension, interventricular septal thickness, left ventricular posterior wall thickness, left ventricular end-diastolic dimension, left ventricular end-systolic dimension, mitral valve area, left ventricular end-diastolic area, and left ventricular end-systolic area in each session. All students performed echocardiography on the same subjects during the training. The effectiveness of the training was evaluated for accuracy and reproducibility after the end of the program. Measurements that the ultrasonographer recorded for each subject were defined as standard points (A). These standard points and the measurements by students did not correlate during the first 15 training sessions, but seven of the nine items were significantly associated after the 30th training session. Thus, accuracy was increased by this program. To estimate reproducibility, we compared the dispersion of measurements recorded during each training session. For seven of nine items, the dispersion decreased significantly between the start and the end of the training. Moreover, when the dispersion that the ultrasonographer obtained in one subject was defined as a standard point (B), six of the nine items of dispersion were equal to the standard point (B) after the training. These data indicated improved reproducibility after the program. We next examined the dispersion of measurements for each student by analysis of variance. Dispersion of measurements decreased after 30 training sessions, but increased when the subjects were changed. At least 30 training sessions conducted by skillful sonographers were effective in teaching beginners to acquire useful echocardiographic images. We also discovered that the subjects should be changed during the training.