Brodoefel Harald, Reimann Anja, Klumpp Bernhard, Fenchel Michael, Ohmer Martin, Miller Stephan, Schroeder Stephen, Claussen Claus, Scheule Albertus, Kopp Andreas F
Department of Diagnostic Radiology, Eberhard-Karls-University, Tübingen, Germany.
J Comput Assist Tomogr. 2007 Mar-Apr;31(2):290-8. doi: 10.1097/01.rct.0000237806.57757.e6.
To assess myocardial viability in acute and subacute infarcts using different multislice spiral computed tomography contrast protocols with magnetic resonance imaging (MRI) correlation.
Seven pigs were studied with 64-multislice spiral computed tomography and MRI (1.5 T) at a median of 1 and 21 days after temporary occlusion of the second diagonal branch. Computed tomography was performed at 3, 5, 10, and 15 minutes after injection of contrast medium. Contrast agent was applied either as a bolus (protocol 1; n = 7 for the first; n = 5 for the second scan) or as a bolus plus 30 mL of subsequent 0.1 mL/s low-flow (protocol 2; n = 7 for the first; n = 6 for the second scan). Finally, histological sections were obtained. Volumes of infarcted myocardium were assessed as the percentage of the left ventricle. Computed tomography attenuation values were obtained, and image quality was assessed.
When compared with protocol 1, protocol 2 provided greater Hounsfield unit attenuation difference between viable and nonviable myocardium at 5, 10, and 15 minutes (P = 0.19; 0.003; 0.0006) and an additional significant contrast between nonviable myocardium and ventricular blood at 3 and 5 minutes (P < 0.001). Image quality was rated significantly higher with the use of protocol 2 at 5, 10, and 15 minutes (P < or = 0.027) and for all time points use of protocol 2 resulted in improved correlation of acute and subacute infarct size with MRI.
Good correlation of infarct zones with MRI was achieved for both acute and subacute infarcts. With the use of a bolus/low-flow protocol, image quality was substantially improved by means of a higher tissue contrast.
采用不同的多层螺旋计算机断层扫描对比剂方案并与磁共振成像（MRI）进行对比，评估急性和亚急性梗死心肌的存活情况。
对7头猪在临时阻断第二对角支后第1天和第21天的中位数时间，进行64层螺旋计算机断层扫描和MRI（1.5T）检查。在注射对比剂后3、5、10和15分钟进行计算机断层扫描。对比剂采用团注（方案1；首次扫描n = 7；第二次扫描n = 5）或团注加随后30 mL的0.1 mL/s低流量注射（方案2；首次扫描n = 7；第二次扫描n = 6）。最后，获取组织学切片。梗死心肌体积以左心室的百分比进行评估。获取计算机断层扫描衰减值，并评估图像质量。
与方案1相比，方案2在5、10和15分钟时，存活心肌和无存活心肌之间的亨氏单位衰减差异更大（P = 0.19；0.003；0.0006），并且在3和5分钟时无存活心肌与心室血之间有额外的显著对比（P < 0.001）。在5、10和15分钟时，使用方案2的图像质量评分显著更高（P ≤ 0.027），并且在所有时间点，使用方案2均改善了急性和亚急性梗死大小与MRI的相关性。
急性和亚急性梗死灶与MRI均具有良好的相关性。采用团注/低流量方案，通过更高的组织对比度可显著提高图像质量。
