Pyogenic Spondylitis: MR Imaging Findings

ABSTRACT

PURPOSE: To prevent permanent neurologic deficit and/or spinal deformity in pyogenic spondylitis earlydiagnosis and prompt treatment are essential. The purpose of this study is to determine the MR imaging findings ofpyogenic spondylitis. MATERIALS AND METHODS: In 31 patients with pathologically or clinically proven pyogenicspondylitis, MR images(31, T1-weighted ; 30, T2-weighted ; 31, Gd-enhanced T1-weighted) were retrospectivelyanalyzed. Analysis focused on the signal intensity and enhancement pattern of involved vertebral bodies andintervertebral discs, as well as paravertebral soft tissue abnormality. RESULTS: A total of 77 vertebral bodies(mean, 2.5 per patient) were involved. Signal intensity was low in 58 of 77 T1-weighted images, high in 63 of 75T2-weighted images and in 72 of 77 contrast-enhanced T1-weighted images, enhancement was diffuse. A total of 47intervertebral discs were involved. Signal intensity was low or intermediate in all 47 T1-weighted images, andhigh or intermediate in 38/46 T2-weighted images ; in 24 of 38 contrast-enhanced T1-weighted images, signalintensity was peripheral, and in 14, enhancement was diffuse. Twenty-six patients showed diffusely enhancedparavertebral soft tissue abnormality and in 14, the largest diameter was less than 1cm. CONCLUSION: With regardto vertebral bodies, MR imaging findings of pyogenic spondylitis are low signal intensity on T1-weighted images,and high or intermediate signal intensity on T2-weighted images, together with diffuse enhancement. Forintervertebral discs, signal intensity was low on T1-weighted images, high on T2-weighted images, and peripheralor diffuse enhancement was seen. Diffusely enhanced small paravertebral soft tissue abnormality was also present.