Background: Bone, soft-tissue, and articular lesions are often well
visualized by magnetic resonance imaging. Our goal was to evaluate the
diagnostic performance of magnetic resonance imaging-guided biopsies of
selected musculoskeletal lesions.
Methods: In this retrospective case series, forty-five consecutive
biopsies were performed in an open mid-field 0.5-T interventional magnetic
resonance imaging unit with a real-time guidance system. The biopsies were
performed at twenty bone, eighteen extra-articular soft-tissue, and seven
intra-articular soft-tissue sites. The main reasons for using magnetic
resonance imaging guidance were the need to improve lesion conspicuity
compared with that provided by other imaging modalities, the need for
site-specific targeting within the lesion, and the need for real-time
guidance. Samples were obtained with fine-needle aspiration, core-needle
biopsy, or a combination of these techniques. An independent reference
standard was used to confirm the final diagnosis. 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). Complications were identified as well.
Results: The diagnostic yield was 91% (forty-one of forty-five
biopsies yielded sufficient material for a diagnosis) overall, 95% (nineteen
of twenty) for the bone lesions, 94% (seventeen of eighteen) for the
extra-articular soft-tissue lesions, and 71% (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 respective values were 0.92, 1.00, 1.00, and 0.86 for the bone
lesions; 0.77, 1.00, 1.00, and 0.57 for the extra-articular soft-tissue
lesions; and 1.00, 1.00, 1.00, and 1.00 for the intra-articular soft-tissue
lesions. There was one complication: exacerbation of neuropathic pain related
to a biopsy of a peripheral nerve sheath tumor.
Conclusions: Magnetic resonance imaging-guided percutaneous biopsies
of musculoskeletal lesions for which other imaging modalities might be
inadequate have a good diagnostic performance overall. The performance can be
very good for bone lesions, moderate for extra-articular soft-tissue lesions,
and fair for intra-articular soft-tissue lesions.
Level of Evidence: Diagnostic Level II. See Instructions
to Authors for a complete description of levels of evidence.