Radiographic Features of Tuberculous Osteitis in Greater Trochanter and Ischium

PURPOSE: To evaluate, if possible, the radiographic features of tuberculous osteitis in the greater trochanter and ischium, and to determine the cause of the lesions. MATERIALS AND METHODS: We retrospectively reviewed the plain radiographic findings of 14 ptients with histologically proven tuberculous osteitis involvingthe greater trochanter and ischium. In each case, the following were analyzed : morphology of bone destruction, including cortical erosion; periosteal reaction ; presence or abscence of calcific shadows in adjacent softtissue. On the basis of an analysis of radiographic features and correlation of the anatomy with adjacent structures we attempted to determine causes. RESULTS: Of the 14 cases evaluated, 12 showed varrious degrees of extrinsic erosion on the outer cortical bone of the greater trochanter and ischium ; in two cases, bone destruction was so severe that the radiographic features of advanced perforated osteomyelitis were simulated. Inaddition to findings of bone destruction, in these twelve cases, the presence of sequestrum or calcific shadows was seen in adjacent soft tissue. CONCLUSION: Tuberculous osteitis in the greater trochanter and ischium showed the characteristic findings of chronic extrinsic erosion. On the basis of these findings we can suggest that the selesions result from an extrinsic pathophysiologic cause such as adjacent bursitis.

Differentiation between Tuberculous and Pyogenic Spondylitis: MR Imaging Characteristics of Paraspinal Mass

PURPOSE: To determine the MR imaging findings for the differentiation of tuberculous spondylitis(TS) and pyogenic spondylitis(PS) with emphasis on the shape and MR signal characteristics of paraspinal mass. MATERIALS AND METHODS: We obtained spin-echo T1- and T2-weighted MR images of 63 surgically proved cases of TS and 15 casesof PS. Gadopentetate dimeglumine(Gd)-enhanced T1-weighted MR images in 37 cases of TS and in all 15 cases of PS were also obtained. Paraspinal mass formation, the size, shape and Gd-enhancing pattern of this mass and penetration of paraspinal ligaments by inflammatory tissue were analyzed. RESULTS: Paraspinal mass was found inboth TS(63/63) and PS(9/15). The mean longitudinal dimension of this mass was 4.3 vertebral body heights in TS and1.8 in PS. The margin of the mass was smooth in TS due to subligamentous spread of inflammation, while PS showedan irregular margin and invaded the para-aortic or para-caval space(9/15) due to penetration of inflammatory tissue through the paraspinal ligament. In the lumbar spine, however, TS showed focal penetration of the paraspinal ligament and formed psoas abscesses. After Gd enhancement, TS showed irregular thick or uniformly thinrim enhancement(35/37), suggesting caseation necrosis and cold abscess, while PS showed diffuse enhancement, suggesting abundant granulation tissue. CONCLUSION: MR imaging findings helpful for the differentiation of TS andPS were size, shape and enhancing pattern of paraspinal mass and penetration of paraspinal ligament by inflammatory tissue.