Differential Diagnosis of Degenerative Vertebral Endplate Changes and Diskitis in MRI

OBJECTIVE: The purpose of this study was to determine differential findings between Type I degenerative endplate changes and diskitis on MR images. MATERIALS AND METHODS: MR images(T1, T2 weighted or Gradient echo) of L-spine in twelve patients with a Type I degenerative endplate change and nine patients with diskitis were reviewed for the morphologic and signal intensity changes of intervertebral disc, vertebral endplate and vertebral body. RESULTS: involvement of the marrow of one side of intervertebral disk was noted in 33%(4/12) of Type I endplate changes, and 11%(1/9) of diskitis. Decreased signal intensity of intervertebral disc was seen in 92% (11/12) of Type I endplate changes, and 11%(1/9) of diskitis on T2 weighted or Gradient echo image. Loss of intranuclear cleft signal was noted in 17%(2/12) of Type I endplate changes, and 78%(7/9) of diskitis. Even disc space narrowing was seen in all cases of Type I endplate changes, but uneven narrowing was seen in 44%(4/9) of diskitis. Only partial cortical disruption was noted in 42%(5/12) of Type I endplate changes, while partial or total cortical disruption was noted in 89%(8/9) of diskitis. The extent of marrow involvement more than 2/3 was noted in 8%(1/12) of Type I endplate changes, but 56%(5/9) of diskitis. The margin of signal intensity change was well defined in 33%(4/12) of Type I endplate changes, but that of diskitis was ill defined in all cases(9/9). Gadolinium enhancement was homogeneous in all cases(5/5) of Type I endplate changes, and 63%(5/8) of diskiris. CONCLUSION: We conclude that involvement of one side of endplate, decreased signal intensity of intervertebral disc on T2 weighted or gradient echo image, even narrowing of disc space, lesser extent of marrow involvement, well defined margin and homogeneous enhancement pattern are the findings of Type I degenerative endplate changes on MR images.