Department of Neuroradiology, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
Acad Radiol. 2010 Feb;17(2):188-93. doi: 10.1016/j.acra.2009.08.014. Epub 2009 Nov 11.
The aim of this study was to compare tumor signal and contrast media uptake characteristics on contrast-enhanced T1-weighted sequences at 3 Tesla over 30 minutes after double-dose administration of different contrast agents in an animal model of brain glioma.
Nine rats underwent magnetic resonance imaging (MRI) after stereotactic F98 glioma cell implantation before and repetitively for 30 minutes after injection of gadobutrol, gadopentetate, and gadobenate, respectively. Signal-to-noise ratio (SNR) and tumor contrast-to-noise ratio (CNR) were evaluated and MRI-derived tumor volumes were compared to histology.
Postcontrast tumor SNR and CNR peaked at 4 minutes after contrast application. While contrast-enhancement within the tumor was fading, tumor volume increased by continuous contrast-uptake of peripheral parts between 4 minutes (137 + or - 29 mm(3), 126 + or - 16 mm(3), 141 + or - 24 mm(3)) and 20 minutes (182 + or - 35 mm(3), 164 + or - 32 mm(3), 191 + or - 25 mm(3)), respectively. At 8 and 12 minutes, 84% and 91% of the tumor volume were definable, respectively.
Optimal correlation between MRI-derived tumor volume and histology is achieved by imaging up to 20 minutes after contrast application. At 4 minutes (this delay is mostly used in clinical routine), only 75% of the enhancing tumor volume is assessable. A delay of 8 minutes already reveals 84% of the tumor and seems to be a practical clinical compromise.
本研究旨在对比分析在脑胶质瘤动物模型中，两种剂量对比剂（钆布醇、钆喷酸葡胺、钆贝葡胺）经 3T 磁共振增强扫描后 30 分钟内肿瘤信号和对比剂摄取特征。
9 只大鼠在立体定向 F98 神经胶质瘤细胞种植后进行磁共振成像（MRI），分别在注射后即刻、4 分钟、8 分钟、12 分钟、16 分钟、20 分钟和 30 分钟进行重复扫描。评估信噪比（SNR）和肿瘤对比噪声比（CNR），并将 MRI 测量的肿瘤体积与组织学结果进行比较。
增强后肿瘤 SNR 和 CNR 于 4 分钟时达峰值。肿瘤强化消退时，周围组织的对比剂摄取使肿瘤体积持续增加，分别在 4 分钟（137±29mm3）、126±16mm3）、141±24mm3）和 20 分钟（182±35mm3）、164±32mm3）、191±25mm3）时达到高峰。在 8 分钟和 12 分钟时，分别有 84%和 91%的肿瘤体积可被定义。
在增强后 20 分钟内进行成像，可使 MRI 测量的肿瘤体积与组织学结果达到最佳相关性。在 4 分钟时（这是临床常规中最常用的延迟时间），仅能评估 75%的强化肿瘤体积。8 分钟的延迟时间已能显示 84%的肿瘤，似乎是一个实用的临床折衷。
