Liu Wangyan, Zhu Yinsu, Tang Lijun, Zhu Xiaomei, Xu Yi, Yang Guanyu
Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
Laboratory of Image Science and Technology, School of Computer Science and Engineering, Southeast University, Nanjing, Jiangsu 210096, P.R. China.
Exp Ther Med. 2016 Aug;12(2):753-758. doi: 10.3892/etm.2016.3414. Epub 2016 Jun 1.
Kidney volume is an important parameter in clinical practice, and accurate assessment of kidney volume is vital. The aim of the present study was to evaluate the effect of various environments, tube voltages, tube currents and slice thicknesses on the accuracy of a novel segmentation software in determining renal volume on computed tomography (CT) images. The volumes of potatoes and porcine kidneys were measured on CT images and compared with the actual volumes, which were determined by a water displacement method. CT scans were performed under various situations, including different environments (air or oil); tube voltages/tube currents (80 kVp/200 mAs, 120 kVp/200 mAs, 120 kVp/100 mAs); and reconstructed slice thicknesses (0.75 or 1.5 mm). Percentage errors (PEs) relative to the reference standards were calculated. In addition, attenuation and image noise under different CT scanning parameters were compared. Student's t-test was also used to analyze the effect of various conditions on image quality and volume measurements. The results indicated that the volumes measured in oil were closer to the actual volumes (P<0.05). Furthermore, attenuation and image noise significantly increased when using a tube voltage of 80 kVp, while the mean PEs between 120 and 80 kVp voltages were not significantly different. The mean PEs were greater when using a tube current of 100 mAs compared with a current of 200 mAs (P<0.05). In addition, the volumes measured on 1.5 mm slice thickness were closer to the actual volumes (P<0.05). In conclusion, different environments, tube currents and slice thicknesses may affect the volume measurements. In the present study, the most accurate volume measurements were obtained at 120 kVp/200 mAs and a slice thickness of 1.5 mm.
肾脏体积是临床实践中的一个重要参数，准确评估肾脏体积至关重要。本研究的目的是评估各种环境、管电压、管电流和层厚对一种新型分割软件在计算机断层扫描（CT）图像上测定肾脏体积准确性的影响。在CT图像上测量土豆和猪肾的体积，并与通过排水法确定的实际体积进行比较。在各种情况下进行CT扫描，包括不同的环境（空气或油）；管电压/管电流（80 kVp/200 mAs、120 kVp/200 mAs、120 kVp/100 mAs）；以及重建层厚（0.75或1.5 mm）。计算相对于参考标准的百分比误差（PEs）。此外，比较了不同CT扫描参数下的衰减和图像噪声。还使用学生t检验分析各种条件对图像质量和体积测量的影响。结果表明，在油中测量的体积更接近实际体积（P<0.05）。此外，使用80 kVp管电压时，衰减和图像噪声显著增加，而120 kVp和80 kVp电压之间的平均PEs无显著差异。与200 mAs电流相比，使用100 mAs管电流时平均PEs更大（P<0.05）。此外，在1.5 mm层厚上测量的体积更接近实际体积（P<0.05）。总之，不同的环境、管电流和层厚可能会影响体积测量。在本研究中，在120 kVp/200 mAs和1.5 mm层厚下获得了最准确的体积测量结果。
