MR Imaging of the Ankle and Hindfoot

Magnetic Resonance Imaging (MRI) is the diagnostic modality of choice for evaluation of traumatic ligamentous and tendinous injuries of the ankle and hindfoot. MRI is also valuable in the detection of occult bony trauma, osteochondral injuries, avascular necrosis, osteomyelitis, and a variety of other osseous conditions. This unit presents basic protocols for T1‐ and T2‐weighted sequences and short tau inversion recovery (STIR) imaging. Additional imaging following intravenous gadolinium is indicated in selected cases.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145347/1/cpmia2501.pd

Correlation between Rotator Cuff Tears and Systemic Atherosclerotic Disease

The purpose of this study was to investigate the association of aortic arch calcification, a surrogate marker of atherosclerosis, with rotator cuff tendinosis and tears given the hypothesis that decreased tendon vascularity is a contributing factor in the etiology of tendon degeneration. A retrospective review was performed to identify patients ages 50 to 90 years who had a shoulder MRI and a chest radiograph performed within 6 months of each other. Chest radiographs and shoulder MRIs from 120 patients were reviewed by two sets of observers blinded to the others' conclusions. Rotator cuff disease was classified as tendinosis, partial thickness tear, and full thickness tear. The presence or absence of aortic arch calcification was graded and compared with the MRI appearance of the rotator cuff. The tendon tear grading was positively correlated with patient age. However, the tendon tear grading on MRI was not significantly correlated with the aorta calcification scores on chest radiographs. Furthermore, there was no significant correlation between aorta calcification severity and tendon tear grading. In conclusion, rotator cuff tears did not significantly correlate with aortic calcification severity. This suggests that tendon ischemia may not be associated with the degree of macrovascular disease

MR Imaging of the glenohumeral ligaments

The glenohumeral ligaments, particularly the inferior one, are the major passive stabilizers of the joint, and the labrum functions as a site of ligamentous attachment. The strong union between the collagen fibers of the glenohumeral ligaments and the glenoid labrum is more resistant to injury than the union between the glenoid rim and the labmm. Labral tears associated with glenohumeral instability are therefore usually secondary to avulsion rather than impaction. This article reviews the normal MR imaging anatomy, variants and pitfalls of the glenohumeral ligaments, and the basic biomechanics of the glenohumeral ligaments. Examples of injuries involving these structures are provided

ACR Appropriateness Criteria(R) Stress (Fatigue/Insufficiency) Fracture, Including Sacrum, Excluding Other Vertebrae

Stress fractures, including both fatigue and insufficiency types, are frequently encountered in clinical practice as a source of pain in both athletes and patients with predisposing conditions. Radiography is the imaging modality of choice for baseline diagnosis. MRI has greatly improved our ability to diagnose radiographically occult stress fractures. Tc-99m bone scan and CT may also be useful as diagnostic tools. Although fatigue and insufficiency fractures can be self-limited and go onto healing even without diagnosis, there is usually value in initiating prompt therapeutic measures as incomplete stress fractures have the potential of progressing to completion and requiring more invasive treatment or delay in return to activity. This is particularly important in the setting of stress fractures of the femoral neck. Accuracy in the identification of these injuries is also relevant because the differential diagnosis includes entities that would otherwise be treated significantly different (ie, osteoid osteoma, osteomyelitis, and metastasis). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment