Disler D G, Marr D S, Rosenthal D I
Department of Radiology, Massachusetts General Hospital, Boston.
Invest Radiol. 1994 Aug;29(8):739-45. doi: 10.1097/00004424-199408000-00002.
Using an independent three-dimensional workstation, the accuracy of volume measurements of phantoms was assessed using three-dimensional reconstruction of two-dimensional computed tomography (CT) and magnetic resonance (MR) images.
Round, cylindrical, and irregularly shaped high-contrast phantoms of known volume were imaged in a water bath. The effect of object contrast on volume estimation was tested using phantoms of known volume diluted serially with a contrast agent. The effect of changing field of view and slice thickness was assessed. A clinical application was performed, in which nine shoulders were injected with a known quantity of contrast material, to test the accuracy of the technique in vivo.
A strong paired correlation (r = .99) between estimated and true volumes was obtained for high-contrast phantoms ranging from 17 to 128 mL. The weighted average absolute error was 1.42 mL (MR) and 3.50 mL (CT). Accuracy of the serially diluted 27-mL phantoms was essentially unaffected by contrast differences greater than 133 units (MR) and 102 units (CT). The weighted average absolute error was 1.33 mL (MR) and 1.56 mL (CT). Changing field of view had no effect on accuracy, but increasing the slice thickness resulted in over-estimation of volume. The mean error for the clinical application was 4.4% (range: 1.7%-8.3%).
Under certain circumstances, three-dimensional reconstructive volume estimation can be a convenient and accurate method for volume determination.
使用独立的三维工作站，通过二维计算机断层扫描（CT）和磁共振（MR）图像的三维重建来评估体模体积测量的准确性。
将已知体积的圆形、圆柱形和不规则形状的高对比度体模置于水浴中成像。使用用造影剂连续稀释的已知体积体模测试物体对比度对体积估计的影响。评估改变视野和切片厚度的影响。进行了一项临床应用，向九个肩部注射已知量的造影剂，以测试该技术在体内的准确性。
对于体积范围为17至128 mL的高对比度体模，估计体积与真实体积之间获得了强配对相关性（r = 0.99）。加权平均绝对误差为1.42 mL（MR）和3.50 mL（CT）。连续稀释的27 mL体模的准确性基本上不受大于133单位（MR）和102单位（CT）的对比度差异影响。加权平均绝对误差为1.33 mL（MR）和1.56 mL（CT）。改变视野对准确性没有影响，但增加切片厚度会导致体积高估。临床应用的平均误差为4.4%（范围：1.7% - 8.3%）。
在某些情况下，三维重建体积估计可以是一种方便且准确的体积测定方法。
