Revised: February 11, 2011
Accepted: February 15, 2011
Published online: February 18, 2011
Ultrasonography has advantages over other imaging modalities in terms of availability and comfort, safety, and diagnostic potential. Operating costs are low compared with both computed tomography (CT) and magnetic resonance imaging (MRI). The portable equipment is accessible at locations distant from medical centers. Importantly, ultrasonography is performed while patients lie in a comfortable position, without pain or claustrophobia. Ultrasonography is a totally safe noninvasive imaging technique. In contrast to CT and X-rays, it does not emit ionizing radiation. Unlike MRI, it is safe for all patients, including those with cardiac pacemakers and metal implants, without any contraindications. Of the many indications for musculoskeletal ultrasonography, the evaluation of soft tissue pathology is particularly common. In addition, ultrasonography is useful for the detection of fluid collection, and for visualization of cartilage and bone surfaces. Color or power Doppler provides important physiological information, including that relating to the vascular system. The capability of ultrasonography in delineating structures according to their echotextures results in excellent pictorial representation. This imaging principle is based on physical changes in composition, as compared to imaging with MRI, which is based on changes in chemical composition. This article reviews the contribution of sonography to the evaluation of the musculoskeletal system.