Sports imaging aided by advanced visualization
The utilization of 3D isotropic MR arthrography sequences with multiplanar reconstruction can provide similar diagnostic capabilities for labral and rotator cuff lesions as conventional MR arthrography--but in a shorter imaging time, according to research published this month in the American Journal of Roentgenology.

“Faster imaging will lead to decreased motion artifacts, increased convenience of the patient, and improved and more accurate diagnosis because of increased resolution,” the authors wrote.

The researchers, from the departments of radiology and orthopedic surgery at Samsung Medical Center in Seoul, Korea, prospectively compared the diagnostic accuracy of 3D isotropic MR arthrography using a gradient-refocused echo (GRE) technique with conventional MR arthrography for the diagnosis of labral and rotator cuff lesions on a 3T MR unit.

An arthroscopically proven anterior labral lesion in a 22-year-old man with recurrent shoulder dislocation. Axial 3D isotropic MR arthrography image shows lesion (arrow), which was interpreted as anterior labral lesion. Image and caption courtesy of the American Roentgen Ray Society.
Between March and June 2006, the team enrolled 36 consecutive patients who were scheduled for shoulder arthroscopic surgery, which was indicated on the basis of clinical findings and MRI findings. They performed both 3D and conventional MR arthrography exams one day before surgery using a Philips Healthcare 3T Gyroscan Intera Achieva with a dedicated receive-only shoulder coil.

The total scanning time for conventional MR arthrography was 16 minutes 40 seconds, on average; the average 3D fast GRE technique total scanning time was 5 minutes 32 seconds, the researchers reported. The 3D image reconstructions were performed using a PACS (GE Healthcare) embedded program that supplied the capability of simultaneous multi-planar reconstruction (MPR).

The MR images were prospectively evaluated by two musculoskeletal radiologists, one with five years of experience in musculoskeletal MRI and one with two years of experience in musculoskeletal MRI, by consensus. They evaluated labral lesions, subscapularis tendon tears and supraspinatus–infraspinatus tendon tears with conventional MR arthrography sequences; two weeks, they later repeated the evaluation with the 3D isotropic MR arthrography sequences. The orthopedic surgeon recorded an evaluation of the presence or absence of lesions or tears after patient surgery.

The researchers reported that they found no statistically significant differences in the diagnostic efficacy of either imaging method for a labral lesion or rotator cuff tear.

“Although no statistically significant difference was seen, the sensitivity and specificity of the 3D isotropic MR sequence for the diagnosis of anterior labral lesions and the specificity for the superior labrum were slightly higher than the sensitivity and specificity of conventional MR arthrography sequences,” they noted.