At L5-S1, there is a very minimal bulge. There is some disk space narrowing. No significant neural foraminal or spinal canal disease is noted.
At L4-5, there is significant degenerative hypertrophy of the facets. Each of the synovial joint is filled with fluid and is hypertrophied. In addition, there is ligamentum flavum hypertrophy. More significantly is an area of soft tissue and probable degenerative cyst anterior to the right facet, which narrows the right recess and significantly narrows the right neural foramen and could easily affect the right crossing nerve root. The left neural foramen is also narrowed by this disease. It is most likely that this bilateral degenerative change of the facet joints and the accompanying probable cyst anterior, on the right, is accounting for the right radicular symptoms. Because there is a very small amount of isointense material seen near the area of the presumed facet cyst, it may be worthwhile to either follow this up in the future with a repeat MRI, perhaps with contrast and fat saturation, to make sure this area does not enhance, although felt unlikely to represent metastasis. This small area is not definitely all related to the degenerative process but may involve some granulation tissue due to chronic irritation or perhaps other disease.
At L3-4, there is a very mild left recess disk bulge. It produces only minimal narrowing of the inferior neural foramen. No spinal canal encroachment is noted. The right neural foramen is not significantly affected.
At L2-3, again, there is a very mild bulge to the left, and again, the right neural foramen appears widely patent.
IMPRESSION:
1. At L4-5, we see bilateral neural foraminal narrowing but particularly on the right. This is due to the presence of a very mild disk bulge but more importantly due to significant facet hypertrophy and synovial fluid irritation within the facet joint itself and suggesting a small degenerative cyst directly of the synovium on the right. This produces posterior compression in the right recess area in addition to the mild disk bulge and would definitely affect the right crossing nerve root.
2. In the area that is believed most likely to represent a small degenerative cyst, presenting anterior to the right facet at L4-5, is a small area of isointense signal to bone. This is also isointense to soft tissue. Most likely, this is an area of bony granulation or degenerative change related to the facet degenerative change. However, as it is not of either high fluid signal or of definite cortical bone, I would recommend that this area be followed either by MRI or other modality in the future. This L4-5 level does present with a relative trilateral stenosis due to the disk and predominantly the facet degenerative changes just described. A mild element of ligamentum hypertrophy is also present.
3. There is mild left-sided narrowing of the inferior aspect of the neural foramen by bulges of the disk to the left at both L3-4 and L2-3. This is not felt significant in nature.
4. No definite metastases are seen to the vertebral bodies on this exam.
