Lumbar Spine Bone MRI: A Radiation-Free Approach Utilizing CT-Like Imaging for Diagnosing Pars Defects in the Adolescent Spine.

BACKGROUND AND PURPOSE: This is a retrospective cohort study to assess the quality of a synthetic bone MRI protocol by using the spoiled GRE (SPGRE) sequence and determine its usability in detecting pars defects in adolescent patients for orthopedic surgeons and radiologists.

MATERIALS AND

METHODS

This retrospective study included 30 adolescent patients with lumbar spondylolysis and low back pain. Patients underwent a clinical lumbar spine MRI at 3T that included a 3D SPGRE sequence; 5 patients also underwent a CT for comparison. An orthopedic spine surgeon and an attending radiologist analyzed inverted SGPR and CT images, assessing the presence of a lumbar pars defect and image quality using a 5-point Likert scale. The interreader agreement was calculated.

RESULTS

Thirty patients were identified with pars defects seen in all patients on the SPGRE MRI. Image quality scores on a 5-point Likert scale measured an overall average of 4.53 ± 0.60, corresponding to good to perfect image quality, with a substantial interrater agreement with a Gwet AC2 of 0.79 [0.71, 0.88], without significant difference between the orthopedic surgeon and the radiologist (orthopedic surgeon's score 4.50 ± 0.63, radiologist's score 4.53 ± 0.57; P = .91).

CONCLUSIONS

A synthetic bone MRI protocol using SPGRE is a viable, nonionizing alternative to CT for visualizing pars defects in adolescent patients, providing sufficient image quality for radiologists and orthopedic surgeons.