Disc and nerve root findings on lumbar MRI with straightened v s flexed hips and knees—pilot study

Objective: To compare disc and nerve root findings, image quality, and pain between supine lumbar MRI positions with straightened v s flexed hips and knees. Methods: In this prospective pilot study, 14 adults with sciatica or suspected lumbar radiculopathy underwent MRI supine with their hips and knees flexed and then straightened. For each position, two experienced radiologists assessed disc contour, location/size of disc herniation, nerve root affection, image quality, image evaluation difficulty, and sagittal angles between the vertebral bodies at each disc level L3-S1. Patients scored pain (0–10) after MRI in each position. We compared MRI assessments and mean pain scores (t-test, log-transformation) between the two positions. Results: We found no clear difference in disc bulges, disc herniation, nerve root affection, image quality, or image evaluation difficulty between MRI with straightened v s flexed knees/hips. Herniation size differed ≤ 0.6 mm between the two positions. Sagittal angles between ne...