Discrimination between Lumbar Intraspinal Stenosis and Foraminal Stenosis using Diffusion Tensor Imaging Parameters:...

Area of Science:

• Neurosurgery
• Radiology
• Medical Imaging

Background:

• Distinguishing between lumbar intraspinal stenosis (IS) and foraminal stenosis (FS) is crucial for surgical planning.
• Accurate differentiation between IS and FS can be challenging using conventional methods.

Purpose of the Study:

• To evaluate the utility of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values derived from diffusion tensor imaging (DTI).
• To discriminate between lumbar intraspinal stenosis (IS) and foraminal stenosis (FS) by analyzing DTI parameters of affected nerves.

Main Methods:

• A retrospective observational study involving 9 IS cases, 7 FS cases, and 5 healthy controls.
• Regions of interest were defined in the intraspinal zone (Iz), nerve root (N), and extraforaminal zone (Ez).
• FA and ADC values, along with their respective ratios (affected/unaffected side ×100%), were measured and analyzed.

Main Results:

• Significantly lower FA values and FA ratios were observed in the extraforaminal zone (Ez) for FS compared to IS.
• Significantly higher ADC values were found in the intraspinal zone (Iz) for IS compared to FS.
• Receiver operating characteristic analysis indicated that FA values in the Ez demonstrated higher diagnostic accuracy for FS, with a cut-off value of 0.42.

Conclusions:

• Reduced FA values in the extraforaminal zone are indicative of foraminal stenosis.
• Established cut-off values for FA (0.42) and FA ratio (83.9%) offer high accuracy in diagnosing foraminal stenosis.
• DTI parameters show promise as a tool to aid in discriminating between intraspinal stenosis and foraminal stenosis.