-loss of disc space and signal at L4-5 is once more noted and also at L5-S1.
-The marrow signal replacement of L5 appears to cross the midline but is most destructive to the left of the midline where breach of posterior cortex is noted with extension of soft tissue into the central canal and left L5 exit foramina. There is now less marked displacement of the thecal sac is compressed to previous MRI with fat signal now visible in relation to the exiting L5 nerve root.
-The lumbar epidural collection to the left of the midline extends craniocaudally from the superior endplate of L5 to behind the S1 vertebra with change in signal however only minimal displacement of the left S1 nerve root
-The prevertebral and left paravertebral mass that extends into the left psoas is once more noted and appears to have signal change consistent with the presence of necrosis with intermediate low signal within high signal. The paravertebral abnormality extends from the level of L4 to the level of S2 as on previous MRI but appears to be septated with reduced AP diameter.
Conclusion:
lumbar spine collection, anterior, spread along ALL-Tb
Tubercular spondylodiscitis usually begins in the antero-inferior part of the vertebral body. The spread of infection occurs under the anterior longitudinal ligament, a structure that involves adjacent vertebral bodies. The narrowing of the disc space occurs secondarily and is not as pronounced as in pyogenic infections. The relative saving of the intervertebral disc appears to be due to the lack of proteolytic enzymes in Mycobacterium tuberculosis