The Role of Radiologic Imaging in the
Orthopedic Impairment Evaluation
During the course of the evaluation of patients who have acute, sub acute, or chronic injuries that limit their occupational capacity or activities of daily living (ADL), a clinician will frequently order diagnostic tests to determine if there is objective evidence of tissue dysfunction. Because injuries to the musculoskeletal system are a frequent cause of impairment, it is important for the clinician working with these patients to understand the efficacy of the diagnostic tests that are available to assess these clinical problems. Radiological imaging studies have been heavily utilized to document objective pathologic changes in the musculoskeletal system, but to use these tests effectively it is necessary to understand their strengths and limitations. The efficacy of these tests is not only affected by the quality of the study but by the expertise of the individual who interprets the examination. The additional data provided by these tests only become useful clinical information when integrated with the patient’s history, physical examination, and other diagnostic tests.
The radiologic studies that are frequently ordered in the evaluation of the musculoskeletal disability include standard plain films, magnetic resonance imaging (MRI), radionuclide studies, ultrasound (US), and computed tomography (CT). This chapter will focus on the application of plain films, MRI, US, and CT have played a major role in the detection of osseous abnormalities in the body, whereas MRI has been particularly useful in the assessment of soft tissue injury (eg, cartilage, muscles, tendons, and ligaments). In addition, MRI is particularly sensitive to detect abnormalities of cancellous bone. The application of US is limited to the assessment of superficial soft tissue structures. A basic understanding of the physics and the technical factors involved in these different modalities is needed in order to facilitate the selection of the appropriate imaging modality for different diagnostic problems.