超高速CT评价心室容积准确性的研究

Evaluation of the accuracy of ventricular volume measurement by ultrafast CT

目的：（１）评价超高速ＣＴ（ＵＦＣＴ）计算心室容积的准确性；（２）比较长轴和短轴观在计算心室容积的差异。材料与方法：采用ＩｍａｔｒｏｎＣ－１５０超高速ＣＴ扫描系统对１４个人的心脏左室铸型和１５个人的心脏右室铸型进行扫描。以修正的面积－长径（Ｓｉｍｐｓｏｎ）法计算左右心室铸型的容积。心室铸型的实际容积通过铸型排除水的容量来计算。结果：左、右心室的实际容积分别为５５．５７±２８．９１ｍｌ和６４．２３±２４．５１ｍｌ；ＵＦＣＴ长轴观计算的左、右心室的容积分别为６６．５０±３３．０４ｍｌ和７６．４７±２８．７０ｍｌ，ＵＦＣＴ短轴观计算的左、右心室的容积分别为６０．３６±２９．９０ｍｌ和７５．３６±２８．７３ｍｌ。ＵＦＣＴ的计算值均明显大于心室容积的实际值（Ｐ＜０．００１），长轴观和短轴观计算的左心室容积值之间亦有显著差异（Ｐ＜０．００１），但长轴观和短轴观计算的右室容积值之间则无显著差异（Ｐ＝０．３２４）。ＵＦＣＴ计算的心室容积与心室的实际容积间有高度相关性（ｒ均＞０．９９０），长轴观与短轴观计算的左、右心室容积之间亦有高度相关性（ｒ均为０．９９９）。结论：ＵＦＣＴ能够准确计算心室容积，并且长轴观和短轴观在计算心室?

Purpose: (1) To evaluate the accuracy of ventricular volume measured by ultrafast CT (UFCT); and (2) compare the value of ventricular volume derived from long and short axis view. Materials and methods: Fourteen human left ventricular casts and 15 right ventricular casts were scanned by Imatron C 150 scanner along both the long and short axis. The scan protocol was similar to that used in vivo. Eight 7 mm thick slices were obtained from each cast for both long and short axis views. Ventricular volume was determined by the modified Simpson′s rule provided by Imatron Inc. The actual volumes of the ventricular casts were determined by the amount of water displacement by the cast. Results: The actual volumes for left and right ventricles were 55.57±28.91 ml and 64.23±24.51ml, respectively, the left and right ventricular volumes determined by UFCT were 66.50±33.04ml and 76.47±28.70 ml from long axis view, and 60.36±29.90 ml and 75.36±28.73 ml from short axis view, respectively. The measurements by UFCT were significantly greater than the actual volumes of the casts, both for the left and right ventricles ( P <0.001). For the left ventricular volume, the measurements from the long axis view were significantly greater than those from the short axis view ( P <0.001); however, for the right ventricular volume, there were not significant differences between measurements from long and short axis view ( P =0.324). Linear regression analysis showed that there was close correlation between the actual ventricular volumes and the calculated volumes determined by UFCT, for both left and right ventricles, moreover, there was also close correlation between ventricular volumes from long and short axis view for both left