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Objectives: To correlate magnetic resonance imaging (MRI) aspects of the femoral head with histological findings in advanced hip osteoarthritis (OA), with special emphasis on bone marrow edema (BME)., Methods: MRI was performed in patients with advanced hip OA scheduled for hip arthroplasty. Coronal T1-, fat-suppressed T2-, T1 with gadolinium intravenous injection sequences were obtained on a 1.5 T MR-scanner within 1 month before surgery. Coronal MR images corresponding to the ligamentum teres plane were analyzed by two independent readers blinded to histological data. Normal bone marrow, subchondral cyst, subchondral fracture, edema-like, necrosis-like, and necrosis MR patterns were reported on a synthesis scheme. After surgery, the femoral heads specimens were cut through the ligamentum teres plane and histologically analyzed for correlations., Results: Twenty-three femoral heads were analyzed (female 56.5%, mean age 64.5 years). Edema-like MR pattern was correlated with histological (H) edema (Kappa (K): 0.77). Necrosis-like MR pattern was correlated with H fibrosis (K: 0.49) and with H necrosis (K: 0.24). Cyst MR pattern was correlated with H bone cysts (K: 0.58). Necrosis MR pattern corresponded to a mixture of histological lesions. Sensitivity and specificity of MRI varied from 26% to 80% and from 86% to 95% respectively., Conclusion: In advanced hip OA, the so-called "BME" MR lesion corresponds to a combination of edema, fibrosis, and necrosis at histopathology. When the classical "BME" is more specifically separated into edema-like and necrosis-like MR patterns, MR Imaging and histological findings show substantial agreement, with edema-like MR pattern mainly corresponding to histological edema., (Copyright © 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: The purpose was to analyze magnetic resonance imaging (MRI) abnormalities in reflex sympathetic dystrophy syndrome (RSDS) of the foot, with the goal of helping to meet the difficult diagnostic challenges raised by this condition., Methods: Retrospective study of 20 patients with RSDS of the foot, 15 at the warm phase and five at the dystrophic phase., Results: Of the 15 patients at the warm phase, seven had evidence of bone edema (low signal on T1-weighted images and high signal on T2, T2 STIR, and fat saturation images) and five had occult fractures (linear band of low signal on T1 and T2 weighted images with no enhancement after contrast injection). Other abnormalities included soft tissue changes in three patients, joint effusion in five, and synovial hypertrophy in one. Of the five patients at the dystrophic phase, one had a fracture with a joint effusion, one had isolated joint edema, and three had normal MRI findings., Conclusion: Bone marrow edema is inconsistent at the warm phase of RSDS and is never present at the dystrophic phase. Thus, absence of bone edema does not rule out RSDS. Fractures may be visible by MRI in one-third of patients with RSDS and no clinical or plain radiography evidence of fracturing.

Purpose: To assess the value of imaging in the differential diagnosis of erosive intervertebral osteochondrosis (EIVO) versus infectious discitis (ID)., Materials and Methods: Twelve cases of EIVO and 30 cases of ID were reviewed to define the usefull signs for differential diagnosis on plain films, CT, and MR., Results: No single sign is sufficient, but the association of several signs is suggestive of EIVO: discal vacuum phenomenom, well-defined sclerosis and erosions of vertebral endplates, high signal strip surrounding low signal of vertebral endplates on T1-weighted images., Conclusion: Imaging is helpful in difficult differential diagnosis of EIVO versus ID.

Thirty-one cases of stage 1 or 2 osteonecrosis (ON) of the hip in 27 patients were studied with T1-weighted coronal magnetic resonance (MR) imaging. Three quantitative parameters were measured on the contiguous MR sections, corresponding to the 2-cm-wide median portion of the femoral head: the angle filled by ON (alpha), the percentage of weight-bearing femoral cortex involved with ON (WB), and the percentage of femoral head surface involved with ON. The clinical and radiologic courses were assessed after at least 2 years of follow-up (mean, 46 months). Core decompression was performed in 12 cases of ON. Values were strikingly lower in the group with good clinical or radiologic outcome versus poor outcome, with very little overlapping. WB was the more reliable parameter. Outcome of hips treated with versus without core decompression appeared closely related with these MR parameters and not with the treatment procedure. Thus, a quantitative approach to determination of extent and location of the lesion on the initial MR image appears accurate for use in the prediction of long-term outcome of ON. Effectiveness of core decompression should be reevaluated on this basis.

An 88-year-old woman complained of pain in the medial part of her knee for 5 weeks. Plain radiography was normal. Clinical and scintigraphic findings were suggestive of spontaneous osteonecrosis of the medial femoral condyle. Magnetic resonance imaging showed a stress fracture of the medial femoral condyle. In 3 weeks pain had disappeared, confirming this diagnosis.

Spinal MRI was performed in 9 multiple myeloma and 2 solitary plasmacytoma, using sagittal, T 1-weighted (TR: 350-550 ms/TE: 15-26 ms) and T 2-weighted (TR: 2,000-2,500 ms/TE: 60-120 ms) sequences, with additional gadolinium injection in 3 cases. MRI features were the following: 1) round, patchy lesions with low T 1 signal highlighted by gadolinium and bright T 2 signal were present in 10 of the 11 patients: all osteolytic lesions seen on plain X-rays corresponded to such lesions and biopsy performed in 4 cases showed massive marrow replacement by plasma cells. 2) overall marrow signal was dramatically decreased in 3 patients (2 of whom had a high tumoral mass). 3) extra-dural compression was present in 4 cases. 4) 25 vertebral compression fractures (10 of whom with a "benign" appearance) and focal fat deposition were seen. 5) postradiation treatment examination seemed predictive of the outcome in the 2 solitary plasmacytomas. MRI proved to be more sensitive than plain X-rays or bone scintigraphy. Number and size of focal tumor-like lesions did not correlate with the low marrow signal appearance. Both correlated poorly with overall tumoral mass but diffuse abnormalities were associated with rapidly fatal outcome in three cases. These features might reflect qualitative rather than quantitative patterns of the disease (nodular or diffuse macroscopic marrow replacement). These findings are in agreement with those of the few previous studies. MRI is valuable for spinal cord damage assessment. It appears less accurate in benign versus malignant vertebral compression fracture determination than it does in bone metastasis. Its prognostic value is still questionable.

Magnetic resonance imaging (MRI) was performed in 60 patients with vertebral compression fractures caused by either bone metastasis (BM) or osteoporosis (OP). In the BM group (20 patients, 62 BM with 22 compression fractures), the signal was decreased on T1-weighted images in all cases and was usually increased on T2 sequences, in the whole vertebral body or in patchy areas. The vertebral body showed a diffuse posterior bulging in 85% of patients; malignant infiltration often involved pedicles, posterior arch or soft tissues. In the OP group (40 patients, 160 vertebral fractures): a significant recession of one of the corners of the vertebral body, different from metastatic bulging, was observed in 37% of patients; the spinal cord signal depended on the stage: during the first 4 months, the signal was low on T1 and high on T2 sequences, with a characteristic band disposition, which may involve most of the vertebral body even in mild fractures; the modifications extended to the pedicles in 5 cases; after 6 months, the signal was normal. MRI specificity was 92% between malignant versus benign compression fractures. MRI had a better sensitivity than bone scan for depicting vertebral BM. In OP, MRI signal modifications disappeared several months before increased uptake of technetium. This study emphasizes the value of MRI for the diagnosis of osteoporotic versus metastatic vertebral compression fractures when morphological and chronological parameters are added to the signal intensity analysis.

Results are reported of the use of new imaging methods, CT scan and magnetic resonance imaging, in 12 patients with algodystrophy of femoral head. During the early stages a CT scan can detect partial demineralizations, observed on MR images in sagittal sections. When the disease is installed the CT scan images show global demineralization, but the MR images with coupled T1-T2 study appear to be more pathognomonic (hyposignal extended in T1 with hypersignal in T2, associated with a more marked subchondral hyposignal in T1 as in T2) particularly in relation to the osteonecrosis of femoral head.