Isotropic high-spatial-resolution 3D data for assessment of pars defects
- Traditional thin cut multi-detector CT (1-2 mm) enables multi-planar reformats and is excellent for detection of pars defects
- However in young patients, MRI could be considered first
- Generally, the acceptable slice thickness is should be no larger than 3 slip 1 mm. Using this slice thickness, the facets can be seen. Note the L5 pars interarticularis (arrow on superior facet).
- Due to the slight obliquity & size of the facets and slice thickness, the facets can sometimes be challenging to evaluate if the cortices are so close.
- A 3D sequence with isotropic thin voxels can be extremely helpful. Here is a coronal T2 non fat sat CUBE sequence acquired with overlapping 1.2 mm thickness skip 0.5 mm. Note the intact L3 pars (inferior facet of L3 show here).
- Scroll through the sequence to appreciate the incredible in-plane resolution.