OSTEOPOROTIC INSUFFICIENCY FRACTURES OF T HE SACRUM - MR-IMAGING FINDINGS

Purpose: Evaluation of the morphologic appearance of sacral osteoporot ic insufficiency fractures in MRI. Patients and method: 6 patients (5 female and one male, 54-80 years) with osteoporotic insufficiency frac tures of the sacrum were examined with CT and MRI. Plain and contrast- enhanced T-1- and T-2-weighted spin-echo images were acquired, three p atients were studied with T-1-weighted gradient-echo-sequences with fa t suppression. Results: Fracture-lines and sclerotic areas of the mass ae laterales were visible in 5 of 6 CT examinations, one patient showe d no abnormalities of the sacrum on the initially performed CT scans. All patients had a diffuse bone marrow oedema of the fractured massae laterales with a decreased signal on the T-1-weighted spin-echo images and an increased signal on the T-1-weighted gradient-echo images with fat suppression and in the T-2-weighted SE-sequences. Gadopentate dim eglumine enhanced MRI images showed a remarkable diffuse configurated high signal of the whole sacrum in bilateral fractures (H-pattern). An additional soft tissue mass could be excluded in each case, Conclusio n: Gadopentate dimeglumine enhanced MRI of sacral insufficiency fractu res allows early diagnosis and helps to exclude intraosseous tumour fo rmation.