Ultrasound is increasingly being used for the initial evaluation of soft-tissue masses of the extremities. Certain clinical and imaging findings allow diagnosis of selected soft-tissue masses; however, most imaging findings are nonspecific, and further evaluation is necessary. The many potential pitfalls can lead to adverse patient outcomes.

MRI is an important tool in assisting clinicians to make a correct diagnosis for the patient who presents with hip pain. Although quadratus femoris muscle tear is an uncommon injury, radiologists should be aware of this entity to assist with making a diagnosis that is usually unsuspected clinically.