扫频成像傅里叶变换在评价糖尿病大鼠皮质骨中的作用。

Usefulness of Sweep Imaging With Fourier Transform for Evaluation of Cortical Bone in Diabetic Rats.

机构信息

Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.

Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.

出版信息

J Magn Reson Imaging. 2018 Aug;48(2):389-397. doi: 10.1002/jmri.25955. Epub 2018 Jan 23.

DOI:10.1002/jmri.25955

PMID:29360263

Abstract

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 < 0.05). At all timepoints, PDWI-SNR showed no significant differences between groups (P = 0.59, 0.70, and 0.82 at 2, 4, and 8 weeks, respectively). SWIFT-SNR was significantly lower in the diabetes group than in the control group (P < 0.05 at 2 and 4 weeks and P < 0.01 at 8 weeks), and the bone formation rate was significantly lower in the diabetes group than in the control group (P < 0.01 for all).

DATA CONCLUSION

SWIFT can detect cortical bone changes even before a decline in the cortical BMD in a diabetic model.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2018;48:389-397.

摘要

背景

糖尿病会降低骨强度，这可能是由于皮质骨发生了变化。傅立叶变换扫频成像（SWIFT）已被报道可用于皮质骨评估。

目的

使用 SWIFT 评估糖尿病大鼠的皮质骨变化，通过与微计算机断层扫描（μCT）和常规 MRI 的比较评估该技术的实用性，并通过组织形态计量学阐明皮质骨变化的机制。

研究类型

动物队列研究。

动物模型

8 周龄雄性 Wistar/ST 大鼠（N=36）分为糖尿病（链脲佐菌素注射诱导）组和对照组。

磁场强度/序列：7.04T MRI，SWIFT。

评估

每组各有 6 只动物在注射后 2、4 和 8 周时处死。提取胫骨并使用 μCT 和 MRI 进行评估。使用 μCT 测量皮质骨骨密度（BMD）。还进行了质子密度加权成像（PDWI）和 SWIFT。计算每个采集的信噪比（SNR）。使用组织形态计量学评估骨形成率。

统计学检验

使用 Mann-Whitney U 检验比较每个时间点的发现。

结果

仅在 8 周时，糖尿病组的皮质 BMD 明显低于对照组（P<0.05）。在所有时间点，PDWI-SNR 组间均无显著差异（P=0.59、0.70 和 0.82，分别在 2、4 和 8 周时）。SWIFT-SNR 在糖尿病组明显低于对照组（在 2 和 4 周时 P<0.05，在 8 周时 P<0.01），糖尿病组的骨形成率也明显低于对照组（所有 P<0.01）。