Fallah Faezeh, Machann Jürgen, Martirosian Petros, Bamberg Fabian, Schick Fritz, Yang Bin
Institute of Signal Processing and System Theory, University of Stuttgart, Pfaffenwaldring 47, 70569, Stuttgart, Germany.
Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Clinic of Tübingen, Tübingen, Germany.
MAGMA. 2017 Apr;30(2):139-151. doi: 10.1007/s10334-016-0588-6. Epub 2016 Sep 16.
To evaluate and compare conventional T1-weighted 2D turbo spin echo (TSE), T1-weighted 3D volumetric interpolated breath-hold examination (VIBE), and two-point 3D Dixon-VIBE sequences for automatic segmentation of visceral adipose tissue (VAT) volume at 3 Tesla by measuring and compensating for errors arising from intensity nonuniformity (INU) and partial volume effects (PVE).
The body trunks of 28 volunteers with body mass index values ranging from 18 to 41.2 kg/m (30.02 ± 6.63 kg/m) were scanned at 3 Tesla using three imaging techniques. Automatic methods were applied to reduce INU and PVE and to segment VAT. The automatically segmented VAT volumes obtained from all acquisitions were then statistically and objectively evaluated against the manually segmented (reference) VAT volumes.
Comparing the reference volumes with the VAT volumes automatically segmented over the uncorrected images showed that INU led to an average relative volume difference of -59.22 ± 11.59, 2.21 ± 47.04, and -43.05 ± 5.01 % for the TSE, VIBE, and Dixon images, respectively, while PVE led to average differences of -34.85 ± 19.85, -15.13 ± 11.04, and -33.79 ± 20.38 %. After signal correction, differences of -2.72 ± 6.60, 34.02 ± 36.99, and -2.23 ± 7.58 % were obtained between the reference and the automatically segmented volumes. A paired-sample two-tailed t test revealed no significant difference between the reference and automatically segmented VAT volumes of the corrected TSE (p = 0.614) and Dixon (p = 0.969) images, but showed a significant VAT overestimation using the corrected VIBE images.
Under similar imaging conditions and spatial resolution, automatically segmented VAT volumes obtained from the corrected TSE and Dixon images agreed with each other and with the reference volumes. These results demonstrate the efficacy of the signal correction methods and the similar accuracy of TSE and Dixon imaging for automatic volumetry of VAT at 3 Tesla.
通过测量和补偿强度不均匀性（INU）和部分容积效应（PVE）引起的误差，评估和比较传统的T1加权二维快速自旋回波（TSE）、T1加权三维容积内插屏气检查（VIBE）以及两点三维狄克逊-VIBE序列在3特斯拉场强下对内脏脂肪组织（VAT）体积进行自动分割的效果。
使用三种成像技术对28名体重指数值在18至41.2 kg/m（平均30.02±6.63 kg/m）之间的志愿者的身体躯干进行3特斯拉场强扫描。采用自动方法减少INU和PVE并分割VAT。然后，将所有采集获得的自动分割的VAT体积与手动分割（参考）的VAT体积进行统计学和客观评估。
将参考体积与未校正图像上自动分割的VAT体积进行比较，结果显示，对于TSE、VIBE和狄克逊图像，INU分别导致平均相对体积差异为-59.22±11.59%、2.21±47.04%和-43.05±5.01%，而PVE分别导致平均差异为-34.85±19.85%、-15.13±11.04%和-33.79±20.38%。信号校正后，参考体积与自动分割体积之间的差异分别为-2.72±6.60%、34.02±36.99%和-2.23±7.58%。配对样本双尾t检验显示，校正后的TSE（p = 0.614）和狄克逊（p = 0.969）图像的参考VAT体积与自动分割的VAT体积之间无显著差异，但校正后的VIBE图像显示VAT有显著高估。
在相似的成像条件和空间分辨率下，校正后的TSE和狄克逊图像获得的自动分割的VAT体积相互一致且与参考体积一致。这些结果证明了信号校正方法的有效性以及TSE和狄克逊成像在3特斯拉场强下对VAT进行自动容积测量时具有相似的准确性。
