Integrating ultrasound technology into teaching gross anatomy: point of order!

U ltrasound (USS) or ultrasonic imaging is now a mature technology having a well-established place in clinical practice and accounting for about one in four of all imaging procedures worldwide (1). More recently, USS has become the latest noninvasive method of morphological study to aid or supplement the teaching of gross human anatomy in some medical school curricula (2 6). Indeed, an expanding use of the technology whether correct or incorrect, or by the trained or untrained has caused the field of radiology to relax its hold on USS (7). USS anatomy is based on its ability to reflect an image of the structures under view which, like any other skill, requires both practice and content-specific knowledge. The popular brightness-mode (B-mode) imaging involves transmitting small pulses of ultrasound echo from a transducer into the body. As the ultrasound waves penetrate body tissues of different acoustic impedances along the path of transmission, some are reflected back to the transducer (echo signals) while others penetrate deeper. The echo signals returned from many sequential pulses are subsequently processed and combined to generate an image. Thus, an ultrasound transducer works both as a speaker (generating sound waves) and a microphone (receiving sound waves) (8). A detailed discussion of the underlying physics and scientific technologies is not warranted here. However, suffice it to say that while USS has much potential to aid in the teaching of medical students, numerous questions arise, including: