TY - CHAP M1 - Book, Section TI - Knee MRI A1 - Tehranzadeh, Arash David A2 - Tehranzadeh, Jamshid PY - 2016 T2 - Basic Musculoskeletal Imaging AB - Magnetic resonance imaging (MRI) interpretation of the knee is often a daunting challenge to the student or physician in training. After all, an entire year of fellowship training is dedicated to musculoskeletal imaging. To overcome this challenge, it is imperative for both the medical student and resident in training to achieve a fundamental understanding of the structural and functional anatomy of the knee. Thus, the initial goal of this chapter is to review the complex anatomic relevant components of the knee. After establishing this anatomic knowledge base, a second goal of this chapter is to provide a systematic approach for interpretation of MRI as it applies to the clinical presentation of internal derangement of the knee. The term “Internal Derangement” is used to cover a group of disorders that affect the normal functioning ligaments, tendons, or cartilage (including the meniscus) of the knee articulation. From a technical standpoint, this is ideally performed with a high field strength 1.5 Tesla or 3 T MRI scanner. Three conventional MRI planes that are utilized to evaluate the knee include sagittal (oblique), coronal, and transaxial planes. While a detailed explanation of MRI protocols and MR physics is beyond the scope of this text, fast spin echo (FSE) MRI is most commonly utilized for MRI of the knee. Specifically, in the coronal and sagittal planes, T1, T2, and intermediate-weighted proton density FSE sequences are often utilized. Fat saturation is employed on some of the fluid-weighted sequences to better detect the presence of edema in the soft tissues or bone marrow. A spin echo or gradient echo sequence is often acquired in the transaxial plane. MRI of the knee may be performed without contrast. Alternatively, utilization of gadolinium contrast agent may be utilized and with regard to internal derangement; this is particularly useful in evaluating the postoperative knee. Administration of gadolinium for an MR arthrogram may be employed. This may be performed with either a direct or indirect technique. With the direct MR arthrogram, a 1:200 dilution of gadolinium in approximately 30 mL of sterile saline is percutaneously injected into the knee joint using a 22-gauge needle. The indirect MR arthrogram is performed after an intravenous injection of gadolinium contrast followed by exercise allowing leakage of contrast agent from the synovium into the joint space and then subsequent MR image acquisition.1 SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessphysiotherapy.mhmedical.com/content.aspx?aid=1127377496 ER -