Search

BACKGROUND Diabetes decreases bone strength, possibly because of cortical bone changes. Sweep imaging with Fourier transform (SWIFT) has been reported to be useful for cortical bone evaluation. PURPOSE To evaluate cortical bone changes in diabetic rats using SWIFT, assess the usefulness of this technique through comparisons with microcomputed tomography (μCT) and conventional MRI, and clarify the mechanism underlying cortical bone changes using histomorphometry STUDY TYPE: Animal cohort. ANIMAL MODEL 8-week-old male Wistar/ST rats (N = 36) were divided into diabetes (induced by streptozotocin injection) and control groups. FIELD STRENGTH/SEQUENCE 7.04T MRI, SWIFT. ASSESSMENT Six animals from each group were sacrificed at 2, 4, and 8 weeks after injection. Tibial bones were extracted and evaluated using μCT and MRI. The cortical bone mineral density (BMD) was measured using μCT. Proton density-weighted imaging (PDWI) and SWIFT were also performed. The signal-to-noise ratio (SNR) was calculated for each acquisition. The bone formation rate was evaluated using histomorphometry. STATISTICAL TESTS Findings at each timepoint were compared using Mann-Whitney U-tests. RESULTS Cortical BMD was significantly lower in the diabetes group than in the control group only at 8 weeks (P

Purpose To evaluate the cortical bone signal-to-noise ratio (SNR) in ovariectomized (OVX) rats during the early postoperative period as a method to measure bone quality using the sweep imaging with Fourier transform (SWIFT) technique. Materials and Methods Twelve-week-old female Sprague–Dawley rats (n = 64) were divided into sham and OVX groups. Preoperative tetracycline was immediately administered subcutaneously to distinguish new cortical bone area, and tibial samples were collected at 2, 4, 8, and 12 weeks postoperatively. Magnetic resonance imaging (MRI) was performed using proton density-weighted imaging (PDWI) and SWIFT to obtain cross-sectional images of the tibial diaphysis. The cortical bone SNR was calculated. Bone histomorphometry was performed. Results Histomorphometry findings showed that the new bone area was significantly greater at 8 and 12 weeks postoperatively in the OVX group (P < 0.05) while the porosity area decreased gradually in both groups (P < 0.001). The difference of SNR receiving PDWI did not reach statistical significance (P = 0.057). The SWIFT technique showed that the SNR was significantly higher at 8 and 12 weeks postoperatively in the OVX group (P < 0.05) and was correlated with the new bone area (R2 = 0.430). Conclusion The SWIFT findings suggest that the SWIFT technique may depict early changes in cortical bone quality. J. Magn. Reson. Imaging 2015;42:128–135. © 2014 Wiley Periodicals, Inc.