Shoulder arthroscopy remains superior to direct MR arthrography for diagnosis of subtle rotator interval lesions.

PURPOSE: To assess the sensitivity, specificity and accuracy of MR arthrography, as opposed to shoulder arthroscopy, in diagnosing individual rotator interval (RI) structures lesions at different levels of severity. MATERIALS AND METHODS: Seventy-five patients were enrolled in a prospective study. All the patients were diagnosed with full-thickness rotator cuff tendon tears on unenhanced MRI and had complimentary MR arthrography to search for obscure RI lesions. All the patients then underwent shoulder arthroscopy. The arthroscopist was blinded about the MR arthrography results. RESULTS: At arthroscopy, 42 patients (56 %) were found to have RI lesion(s) and represented the study group. The remaining 33 patients represented the control group. The sensitivity, specificity and accuracy of MR arthrography for detecting individual RI lesions varied widely depending on the location and severity of the lesions. MR arthrography showed intermediate sensitivity of 67-80 %, specificity of 83-89 % and accuracy of 89-92 % for diagnosing subtle RI lesions; and perfect (100 %) sensitivity, specificity and accuracy for diagnosing biceps long head tendon dislocation. For the rest of RI lesions, MR arthrography showed high sensitivity, specificity and accuracy. Inter-observer agreement was found to be almost perfect (K = 0.81-1.0). CONCLUSION: Shoulder arthroscopy remains the gold standard for diagnosing subtle RI lesions. Although MR arthrography has proved to be a valuable tool for diagnosing established RI lesions, it is of intermediate sensitivity for diagnosing subtle RI lesions resulting in early insufficiency of the biceps pulley system.

Hippocampus dysfunction may explain symptoms of fibromyalgia syndrome. A study with single-voxel magnetic resonance spectroscopy.

OBJECTIVE: (1) To investigate dysfunction of hippocampus in patients with fibromyalgia syndrome (FM) using proton magnetic resonance spectroscopy (1H-MRS), and to compare these findings with healthy controls. (2) To correlate levels of metabolites obtained with aspects of cognition, depression, and sleep symptoms in the patient group. METHODS: The case-control study was performed in 15 female patients, who met American College of Rheumatology criteria for classification of FM, and 10 healthy age-matched female controls. Patients and controls were receiving no medications known to affect cognitive functioning or central nervous system metabolites before their participation in the study. In all patients and controls, 1H-MRS was used to assess N-acetylaspartate (NAA), choline (Cho), creatine (Cr), and their ratios from both hippocampi. Levels of metabolites and their ratios were determined and the findings compared between the groups. All patients and controls underwent psychological assessment to assess cognitive function, depression, and structured sleep interview with sleep diary; Fibromyalgia Impact Questionnaire (FIQ), number of tender points, and visual analog scale (VAS) for pain were assessed in all patients. RESULTS: NAA levels of right and left hippocampi differed significantly between patients and controls (p < 0.05). Cho levels in the right hippocampus were higher in the patient group than in controls (p = 0.005), while no differences were found with respect to Cr levels in both hippocampi. NAA/Cho and NAA/Cr ratios differed significantly between patients and controls (p <0.05), while the Cho/Cr ratio showed no differences. Significant correlations were found between language score and right Cho and right Cr levels (p = 0.041, p = 0.006, respectively), while no significant correlations were found between metabolites and their ratios with FIQ, VAS for pain, or number of tender points. CONCLUSION: The hippocampus was dysfunctional in patients with FM, as shown by lower NAA levels compared to controls, representing neuronal or axonal metabolic dysfunction. As the hippocampus plays crucial roles in maintenance of cognitive functions, sleep regulation, and pain perception, we suggest that metabolic dysfunction of hippocampus may be implicated in the appearance of these symptoms associated with this puzzling syndrome.