Evaluating benign and malignant musculoskeletal lesions with technetium-99m-MIBI scintigraphy and MR imaging

The purpose of this study was to assess the diagnostic potential of 99mTc-MIBI and dynamic MRI in musculoskeletal lesions. Thirty-six patients with various bone and soft tissue pathologies (18 malignant and 18 benign lesions) were studied with 99mTc-MIBI and dynamic MR imaging. Radionuclide angiography with 600 MBq of 99mTc-MIBI was performed and followed with single photon emission computed tomography (SPECT) followed 20 min later. The MIBI-uptake ratio was determined from SPECT, and the MIBI-perfusion index was determined from radionuclide angiography. Dynamic MRI was performed in 26 patients (11 malignant and 15 benign lesions). The MRI-maximum slope index, localization of the maximum slope region, and time-signal intensity curves were assessed. Relationships among these parameters, obtained by 99mTc-MIBI and MRI, and histopathology were studied. The average MIBI-uptake ratio was 4.80±4.43 in malignant masses and 1.83±2.48 in benign lesions (p<0.05). The average MIBI-perfusion index was 18.86±21.48 in malignant masses and 2.54±2.77 in benign lesions (p<0.05). For dynamic MRI, differentiation between benign and malignant lesions was possible with a sensitivity of 100%, a specificity of 80.0%, an accuracy of 88.0% based on the maximum slope region, and a sensitivity of 63.6%, a specificity of 86.7%, accuracy of 76.9% based on the time-signal intensity curve. This study determined that 99mTc-MIBI could be effectively used to differentiate between benign and malignant lesions. (author)