Yuh W T, Tali E T, Nguyen H D, Simonson T M, Mayr N A, Fisher D J
Department of Radiology, University of Iowa College of Medicine, Iowa City, USA.
AJNR Am J Neuroradiol. 1995 Feb;16(2):373-80.
To evaluate the effect of MR contrast dose versus delayed imaging time on the detection of metastatic brain lesions based on lesion size.
Contrast MR examinations with gadoteridol were obtained in 45 patients with brain metastases. The patients were divided into two groups: 16 received cumulative standard dose (0.1 mmol/kg) and 29 received cumulative triple dose (0.3 mmol/kg). Both groups were evaluated at two dose levels (lower dose and higher dose) with two separate injections. Each patient received an initial bolus injection of either 0.05 (cumulative standard dose) or 0.1 (cumulative triple dose) mmol/kg of gadoteridol to reach the lower-dose level and underwent imaging immediately and 10 and 20 minutes later. Thirty minutes after injection, an additional bolus injection of 0.05 (cumulative standard dose) or 0.2 (cumulative triple dose) mmol/kg was administered to reach the cumulative higher-dose level (cumulative standard dose, 0.1 mmol/kg; cumulative triple dose, 0.3 mmol). Images were acquired immediately.
There was no difference in the detection rate for lesions larger than 10 mm among T2-weighted, lower-dose immediate and delayed, or immediate higher-dose images in both study groups. Lesions smaller than 10 mm had improved detection with delayed imaging in both study groups; however, the immediate higher-dose studies still had the highest detection rate.
In the evaluation of small central nervous system metastases, either delayed imaging after the injection of standard contrast dose or higher contrast dose may improve their detection, and therefore affect clinical management. Higher contrast dose (cumulative triple dose) studies appear to be more effective than delayed imaging with standard dose.
基于病变大小评估磁共振对比剂剂量与延迟成像时间对脑转移瘤检测的影响。
对45例脑转移瘤患者进行钆特醇增强磁共振检查。患者分为两组：16例接受累积标准剂量（0.1 mmol/kg），29例接受累积三倍剂量（0.3 mmol/kg）。两组均在两个剂量水平（低剂量和高剂量）进行两次单独注射评估。每位患者先静脉注射0.05（累积标准剂量）或0.1（累积三倍剂量）mmol/kg钆特醇达到低剂量水平，然后立即、10分钟和20分钟后进行成像。注射30分钟后，再静脉注射0.05（累积标准剂量）或0.2（累积三倍剂量）mmol/kg达到累积高剂量水平（累积标准剂量0.1 mmol/kg；累积三倍剂量0.3 mmol），并立即采集图像。
在两个研究组中，T2加权像、低剂量即刻和延迟像或高剂量即刻像上，大于10 mm的病变检测率无差异。两个研究组中，小于10 mm的病变延迟成像时检测率提高；然而，高剂量即刻成像研究的检测率仍然最高。
在评估小的中枢神经系统转移瘤时，注射标准对比剂剂量后延迟成像或使用高对比剂剂量均可提高其检测率，从而影响临床管理。高对比剂剂量（累积三倍剂量）研究似乎比标准剂量延迟成像更有效。
