RESUMEN
BACKGROUND: Ischemia before the development of dysbaric osteonecrosis (DON) in femoral heads has never been investigated. We assessed whether quantitative magnetic resonance spectroscopy (MRS) and diffusion weighted imaging (DWI) could detect dysbaric changes in divers with hip pain. METHODS: This IRB-approved exploratory study recruited 17 divers [9 with hip pain (Group 1); 8 asymptomatic (Group 2)] with normal findings on radiographs and conventional magnetic resonance imaging scans were age-, gender- and body-mass-index matched to 17 non-divers as controls (Group 1C, 2C). Apparent diffusion coefficients (ADCs) and MRS spectra were obtained from regions/voxels of interest on the femoral heads of all subjects. LCModel was used to determine water content, lipid composition, and the unsaturation index in bone marrow. Mann-Whitney non-parametric test was used to compare results of quantitative MRS and ADCs of ipsilateral femoral heads between divers and controls. RESULTS: MRS of the ipsilateral femoral heads revealed higher water (peak: 4.7 ppm) content, lower total lipid fraction (TLF), and higher unsaturation index (UI) of lipids in Group 1 than in Group 2 (water: P=0.040; UI: P=0.022) and Group 1C (water: P=0.027; TLF: P=0.039; UI: P=0.009). In contrast, femoral head ADCs were comparable between divers and controls. Five out of nine symptomatic divers were contacted for follow-up MRS and DWI studies, and the mean difference in water content in the femoral heads of patients with osteonecrosis was also higher than that in patients with symptom relief (osteonecrosis: 0.077±0.130 vs. symptom relief: 0.003±0.010). CONCLUSIONS: Dysbaric change in the femoral heads of divers with hip pain can be detected using quantitative MRS, which reveals increases in water content and UI of lipids, and a decrease in TLF.
RESUMEN
BACKGROUND: Osseous hemangiomas, especially those located in the manubrium, are rare benign tumors. In a review of the literature, only three case reports of sternal hemangioma were found. A precise diagnosis is difficult because of their nonspecific findings on computed tomography (CT)/magnetic resonance imaging (MRI). CASE SUMMARY: An 88-year-old woman was suffering from a progressively enlarging mass in the manubrium. Chest CT images showed an osteolytic and expansile lesion with cortical destruction. Vascular malformation was suspected after CT-guided biopsy. On the dynamic MRI scans, the mass showed a bright signal on the T2-weighted image, peripheral nodular enhancement on the early-phase images and progressive centripetal fill-in on the delayed-phase images. Cavernous hemangioma was suspected preoperatively based on the MRI features and finally confirmed by histopathologic analysis. CONCLUSION: This uncommon case demonstrates the possible characteristic features of manubrium cavernous hemangioma on dynamic MRI scans; knowledge about these features may prevent patients from developing catastrophic complications, such as rupture or internal hemorrhage, caused by biopsy or surgery.
