Role of whole-body diffusion-weighted MRI in detecting bone metastasis
Riccardo Del Vescovo1, Giulia Frauenfelder, Francesco Giurazza
1Department of Radiology, Campus Bio-Medico University of Rome, Rome, Italy, r.delvescovo@unicampus.it.
Purpose:
The aim of this study was to compare the results of whole-body diffusion-weighted magnetic resonance (DW-MR) imaging with staging based on computed tomography (CT) and nuclear scintigraphy using Tc99m results as the standard of reference.
Methods And Materials:
Seventeen patients with known malignant tumours were included in the study. The thorax and the abdomen were imaged using breath-hold diffusion-weighted imaging and T1-weighted imaging sequences in the coronal plane. Location and size of osseous metastases were documented by two experienced radiologists. Whole-body DW-MR imaging findings were compared with results obtained at skeletal scintigraphy and CT bone survey.
Results:
The mean examination time for whole-body DW-MR imaging was 25.5 min. All bone metastases regardless of the size were identified with whole-body DW-MR imaging; MR imaging depicted more bone metastases than CT. Skeletal scintigraphy depicted osseous metastases in 13 patients (with greater sensitivity to the lower limb), whereas whole-body DW-MR imaging revealed osseous metastases in 13 patients (with greater sensitivity to the spine). DW-MR did not show good results for detection of rib cage metastases. The additional osseous metastases seen with MR imaging were confirmed at follow-up examinations and some had a change in therapy. MR identified 22% more metastatic lesions when compared to bone scintigraphy and 119% when compared to CT. Bone scintigraphy identified 80% more metastatic lesions when compared to CT. On a per-patient basis, whole-body DW-MR imaging revealed sensitivity and specificity values of 100%.
Conclusion:
Whole-body DW-MR imaging was more sensitive in the detection of osseous metastases than were skeletal scintigraphy and CT bone survey.
