ABSTRACT
OBJECTIVE: To date, no prospective comparative study of the diagnostic value of STIR versus T1-weighted (T1w) sequences at both 1.5 T and 3 T has been performed with special focus on the detectability of bone metastases. MATERIALS AND METHODS: 212 oncological patients had a whole-body MRI at 1.5 T and/or at 3 T. The standard protocol comprised STIR and T1w sequences. All patients who showed typical signs of bone metastases were included in the study. Evaluation of the images was performed by the calculation of the number of metastases by three independent readers and by visual assessment on a 4-point scale. RESULTS: 86 patients fulfilled the inclusion criteria. The total number of metastases was significantly higher on T1w than on STIR images at both field strengths (p < 0.05). T1w revealed a sensitivity of 99.72% (3 T) and 100.00% (1.5 T) versus STIR with 70.99 % (3 T) and 79.34 % (1.5 T). In 53% (38/72) of all patients, STIR detected fewer bone metastases in comparison with T1w at 3âT. At 1.5 T, STIR showed inferior results in 37.5 % (18/48) of all patients. Qualitative analysis indicated a significantly better lesion conspicuity, lesion delineation and an improved image quality on T1w compared to STIR imaging at both field strengths (p < 0.05) with similar results for T1w at 1.5 T and 3 T, but inferior results for STIR especially at 3 T. CONCLUSION: The whole-body MRI protocol for the detection of bone metastases could safely be limited to the T1w sequence in adults, especially at 3 T. There is no need for an additional STIR sequence. These initial results will have a major impact on the department's workflow if confirmed by larger studies as they will help reduce examination time and therefore save financial resources. KEY POINTS: In a routine MR protocol, T1w imaging is sufficient for the detection of bone metastases. In case of differential diagnostic problems, other appropriate sequences can be added to the protocol. STIR is inferior to T1w in the detection of metastases, especially at 3 T.
Subject(s)
Bone Neoplasms/diagnosis , Bone Neoplasms/secondary , Image Enhancement , Magnetic Resonance Imaging/methods , Spinal Neoplasms/diagnosis , Spinal Neoplasms/secondary , Whole Body Imaging/methods , Aged , Bone and Bones/pathology , Female , Humans , Male , Middle Aged , Prospective Studies , Sensitivity and Specificity , Spine/pathologyABSTRACT
PURPOSE: The purpose of this study was to compare the diagnostic accuracy of whole-body MRI (WB-MRI) and bone scintigraphy (BS) for the screening of bone metastases for the first time in a large and homogeneous patient collective with breast cancer in a systematic and controlled study. MATERIALS AND METHOD: 213 breast cancer patients were evaluated for bone metastases under randomized, double-blinded and prospective conditions at two hospitals. All participants were examined by WB-MRI and BS over an average period of four days. The examinations were performed separately at two different locations. The WB-MRI protocol included T 1-TSE and STIR sequences. WB-MRI and BS were reviewed independently by experienced radiologists and nuclear medicine specialists in a consensus reading. RESULTS: In 66 % of cases bone metastases were excluded by both procedures, and bone metastases were detected concordantly in 2 % of cases. In 7 % of cases there were discrepant results: in 7 cases BS was false-positive when WB-MRI was negative. In 5 / 7 cases BS was negative when WB-MRI identified bone metastases. In 89 % of cases BS was uncertain when WB-MRI was true-negative. In 17 % of cases WB-MRI showed important (non-) tumor-associated findings. The sensitivity, specificity, positive and negative predictive value and diagnostic accuracy for WB-MRI were 90 %, 94 %, 82 %, 98 % and 99 % and for BS those were 40 %, 81 %, 36 %, 91 % and 93 %. CONCLUSION: It could be demonstrated that WB-MRI is superior to BS for detecting bone metastases in breast cancer patients. These results should be considered for the next version of the S 3 guideline "Diagnosis, Therapy and Follow-Up of Breast Cancer".
