title: Screening for bone metastases: whole-body MRI using a 32-channel system versus dual-modality PET-CT.
abstract: The diagnostic accuracy of screening for bone metastases was evaluated using whole-body magnetic resonance imaging (WB-MRI) compared with combined fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) (FDG-PET-CT). In a prospective, blinded study, 30 consecutive patients (18 female, 12 male; 24-76 years) with different oncological diseases and suspected skeletal metastases underwent FDG-PET-CT as well as WB-MRI with the use of parallel imaging (PAT). With a 32-channel scanner, coronal imaging of the entire body and sagittal imaging of the complete spine was performed using T1-weighted and short tau inversion recovery (STIR) sequences in combination. PET-CT was conducted using a low-dose CT for attenuation correction, a PET-emission scan and diagnostic contrast-enhanced CT scan covering the thorax, abdomen and pelvis. Two radiologists read the MRI scans, another radiologist in combination with a nuclear medicine physician read the PET-CT scans, each in consensus. The standard of reference was constituted by radiological follow-up within at least 6 months. In 28 patients, 102 malignant and 25 benign bone lesions were detected and confirmed. WB-MRI showed a sensitivity of 94% (96/102), PET-CT exams achieved 78% (79/102; P<0.001). Specificities were 76% (19/25) for WB-MRI and 80% (20/25) for PET-CT (P>0.05). Diagnostic accuracy was 91% (115/127) and 78% (99/127; P<0.001), respectively. Cut-off size for the detection of malignant bone lesions was 2 mm for WB-MRI and 5 mm for PET-CT. WB-MRI revealed ten additional bone metastases due to the larger field of view. In conclusion, WB-MRI and FDG-PET-CT are robust imaging modalities for a systemic screening for metastatic bone disease. PAT allows WB-MRI bone marrow screening at high spatial resolution and with a diagnostic accuracy superior to PET-CT.
authors.affiliation: Department of Clinical Radiology, University Hospitals Grosshadern, Ludwig-Maximilians-University Munich, Marchioninistr. 15, 81377, München, Germany. gerwin.schmidt@med.uni-muenchen.de
authors.forename: Gerwin P
authors.initials: GP
authors.lastname: Schmidt
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schoenberg
authors.forename: Rupert
authors.initials: R
authors.lastname: Schmid
authors.forename: Robert
authors.initials: R
authors.lastname: Stahl
authors.forename: Reinhold
authors.initials: R
authors.lastname: Tiling
authors.forename: Christoph R
authors.initials: CR
authors.lastname: Becker
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Andrea
authors.initials: A
authors.lastname: Baur-Melnyk
mesh_terms: D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000556:secondary; D003951:Diagnostic Errors; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000175:diagnosis*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging