MRI-guided percutaneous biopsies of musculoskeletal lesions, for which other imaging modalities might be inadequate, perform very well for bone lesions, moderate for extra-articular soft-tissue lesions and fair for intra-articular soft-tissue lesions, according to a new study published in the Oct. 1 issue of The Journal of Bone and Joint Surgery.
The researchers were from Johns Hopkins University in Baltimore, Harvard Medical School and Brigham and Women’s Hospital in Boston. In the retrospective case series, 45 consecutive biopsies were performed in an open-field 0.5-Tesla interventional MRI unit with a real-time guidance system. The biopsies were performed at 20 bone sites, 18 extra-articular soft-tissue sites and seven intra-articular soft-tissue sites.
According to the researchers, samples were obtained with fine-needle aspiration, core-needle biopsy, or a combination of these techniques. Diagnostic performance was evaluated on the basis of the diagnostic yield (the proportion of biopsies yielding sufficient material for pathological evaluation) and diagnostic accuracy (sensitivity, specificity, positive predictive value, and negative predictive value).
The diagnostic yield was 91 percent (41 of 45 biopsies yielded sufficient material for a diagnosis) overall, 95 percent (19 of 20) for the bone lesions, 94 percent (17 of 18) for the extra-articular soft-tissue lesions, and 71 percent (five of seven) for the intra-articular soft-tissue lesions.
With regard to the diagnostic accuracy, the sensitivity was 0.86, the specificity was 1.00, the positive predictive value was 1.00, and the negative predictive value was 0.76 in the overall group.
The investigation was performed at Harvard Medical School and Brigham and Women's Hospital in Boston.