Magnetic resonance imaging guided biopsy of musculoskeletal lesions.

BACKGROUND: Minimally invasive interventional biopsy procedures have the advantages of accurate localization, small incisions, and rapid recovery. The purpose of this study was to clinically test and evaluate the efficacy of the magnetic resonance imaging (MRI)-guidance techniques for obtaining musculoskeletal biopsies using the appropriate imaging modalities and instruments.

METHODS: We used MRI-compatible biopsy needles from the Invivo Bone Biopsy Set (Daum, Germany), and a 1.5-T closed-magnet MRI scanner was used to perform the MRI-guided biopsy. The pulse sequences included fast spin echo T1- and T2-weighted imaging and gradient echo imaging. The inclusion criteria included the presence of bone or soft tissue masses, infectious disease, and other nonspecific lesions that required tissue confirmation. Lesions that could not be visualized by computed tomography (CT) or other imaging modalities were preferred.

RESULTS: From January 2005 through December 2009, 23 patients (12 males and 11 females, aged 11-82 years) underwent musculoskeletal MRI-guided biopsy. The biopsy locations were as follow: spine (n = 12), tibia (n = 3), pelvis (n = 1), femur (n = 2), scapula (n = 1), humerus (n = 1), ulna (n = 1), scapula (n = 1), and soft tissue mass of the shoulder (n = 1). The final diagnoses included bone metastasis (n = 7), spinal osteomyelitis and discitis (n = 5), osteonecrosis after chemotherapy (n = 4), bone marrow change or benign lesion without malignancy (n = 3), insufficiency fracture (n = 1), long bone osteomyelitis (n = 1), soft tissue metastasis (n = 1), and perineural ganglion cyst (n = 1). In 10 of the 23 cases, the lesions were barely visualized or invisible on CT guidance. Pathologic analysis and laboratory culturing revealed that the lesions were successfully accessed by MRI-guided biopsy in 100% (23/23) of cases. No obvious complications developed during or after the procedures.

CONCLUSION: Biopsy under MRI guidance is especially valuable for the localization of bone marrow lesions, viable tumors (after chemotherapy or radiation), and lesions that cannot be visualized using CT. It is both accurate and safe, is a good alternative biopsy method, and may be a good adjunctive technique for the localization of bone lesions for radiofrequency ablation or other interventional procedures.