Study: MRA bests MRI in evaluation of wrist tears
 |
TFCC tears represent a challenging clinical issue, noted Toby O. Smith, MCSP, of University of Anglia in Norwich, U.K., and colleagues. The success of treatment hinges on the accuracy of the diagnosis and ability to define pathology. MRI and MRA have both been suggested as diagnostic options. However, early MRI studies were considered less accurate and more difficult to interpret, according to researchers. MRA is more invasive but may provide additional diagnostic information by providing improved visualization of the morphology and location of the lesion.
Smith and colleagues conducted a meta-analysis to evaluate the diagnostic accuracy of MRI and MRA in the detection of TFCC tears.
The researchers included 21 studies that compared MRI or MRA with arthroscopic or open surgical findings for TFCC injury in the review. The studies included 982 wrists. Researchers examined true-positive, false-positive, false-negative and true-negative values to calculate the sensitivity and specificity in each study.
“The findings of this study suggest that MRA is superior to MRI for the investigation of full-thickness TFCC tears. MRA showed moderate, while MRI demonstrated limited, diagnostic test accuracy for the detection of full-thickness tears,” wrote Smith et al. Both exams were more specific than sensitive.
The researchers pointed out that MR studies provide advantages over CT and conventional arthrography, including its ability to delineate other soft-tissue abnormalities.
However, several unanswered questions remain. Smith and colleagues were unable to determine whether time from imaging to surgery affects the validity of findings. They also acknowledged that image quality of MRI and MRA impacts interpretation of the findings. Furthermore, although multiple MRA techniques were used in the included studies, the researchers were not able to compare their diagnostic accuracy.
Finally, Smith et al wrote that MRA may be comprised by greater costs, invasiveness and the need for contrast material. “Given that the difference in diagnostic test accuracies of the two tests was only marginal, it may be argued that this small difference does not justify the use of the more invasive MRA for all suspected lesions.” Clinicians may not realize an impact on patient outcomes if they switch from MRI to MRA, they continued.
The researchers concluded with a “cautious recommendation” for MRA in cases with questions about the diagnosis and management of patients with ulnar-sided wrist pain.