Gd-DTPA-enhanced 3D MR imaging of cervical degenerative disk disease: initial experience

To assess whether a single enhanced T1-weighted gradient echo volume sequence, with the appropriate reformatted images, could be equivalent to a more conventional 2D set of MR sequences for the evaluation of cervical extradural degenerative disk disease (bony canal and foraminal stenosis; disk herniation).

Sixty-one patients evaluated for extradural degenerative disease by MR were imaged with a "standard" MR examination (Sagittal T1-weighted spin echo, axial low flip angle gradient echo), were then given 0.1 mmol/kg Gd-DTPA intravenously, and reimaged with either a 3D FLASH (fast low angle shot), TR 40/TE 7/1 excitation), 40 degree flip angle, acquired as 64, 2-mm sagittal partitions, or a 3D turbo FLASH (MP RAGE-magnetization prepared rapid acquisition gradient echo) (10/4/1), 10 degree flip angle acquired as 128, 2-mm coronal partitions. The volume sequences were reconstructed in the axial plane, and right and left 45 degree oblique coronal planes. The two sets of examinations (standard vs volume) were prospectively interpreted by two neuroradiologists for quality of examination, and location, type, and severity of extradural degenerative disease in a random, blinded, independent fashion.

There was no significant difference between the standard examination and the 3D MP RAGE for central extradural disease. The 3D FLASH examination was significantly worse than the standard examination in identification of central extradural disease, with an average of 21 herniations not identified, or underestimated in size. Neither the 3D FLASH, nor the 3D MP RAGE examinations showed any significant improvement compared to the routine 2D examination for the location and severity of foraminal disease.

If extradural degenerative disk disease is being evaluated, then a single enhanced 3D T1-weighted imaging sequence taking 6 minutes can be equivalent to a routine set of mixed 2D spin echo and low flip angle gradient echo sequences.