Diagnostic Value of Whole-Body DWI With Background Body Suppression Plus Calculation of Apparent Diffusion Coefficient at 3 T Versus ¹⁸F-FDG PET/CT for Detection of Bone Metastases.

Abstract

<b>OBJECTIVE.</b> The purpose of this study is to evaluate the diagnostic performance of whole-body (WB) DWI with background body suppression (DWIBS) combined with calculation of the apparent diffusion coefficient (ADC) value at 3 T compared with the diagnostic performance of ¹⁸F-FDG PET/CT for detecting bone metastases in patients with malignant tumors. <b>SUBJECTS AND METHODS.</b> Thirty-nine consecutive patients with suspected bone metastases underwent both WB DWIBS and FDG PET/CT. Imaging findings were independently interpreted using qualitative and quantitative analyses. Pathologic findings or clinical or radiologic follow-up data were used as the diagnostic reference standard. The sensitivity, specificity, overall accuracy, positive predictive value, and negative predictive value of both modalities were calculated. The ADCs of benign lesions and metastases were compared. <b>RESULTS.</b> A total of 213 metastatic bone segments were confirmed among 39 patients. The sensitivity, specificity, overall accuracy, positive predictive value, and negative predictive value were 93.0%, 87.8%, 89.6%, 79.8%, and 96.0%, respectively, for WB DWIBS and 92.5%, 92.0%, 92.1%, 85.7% and 95.9%, respectively, for FDG PET/CT. The specificity of WB DWIBS in detecting bone metastases was significantly lower than that of FDG PET/CT (<i>p</i> < 0.05), whereas the sensitivity, overall accuracy, positive predictive value, and negative predictive value in detecting bone metastases were not significantly different between WB DWIBS and FDG PET/CT (<i>p</i> > 0.05). The ADCs for benign lesions were significantly higher than those for metastases (<i>p</i> < 0.001). In ROC curve analysis, the AUC value was 0.901. A cutoff ADC value of 920.5 × 10^-6 mm²s^-1 distinguished benign lesions from bone metastases with a sensitivity of 92.9% and a specificity of 73.4%. <b>CONCLUSION.</b> WB DWIBS coupled with ADC analysis at 3 T is effective for detecting bone metastases.