Department of Radiology, Kyorin University Faculty of Medicine, 6-20-2, Shinkawa, Mitaka, Tokyo 181-8611, Japan.
Magn Reson Med Sci. 2013;12(2):87-93. doi: 10.2463/mrms.2012-0069. Epub 2013 May 10.
Time-resolved contrast-enhanced magnetic resonance (MR) angiography (TCMRA) and perfusion MR imaging (PWI) have been used to assess the hemodynamics of brain tumors. We assessed the feasibility and value of consecutive performance of these techniques to evaluate suspected brain metastasis following supplementary injection of gadolinium-based contrast medium.
In 69 patients with suspected brain metastasis, we obtained precontrast MR images followed by TCMRA and postcontrast T1-weighted images after administration of 0.1 mmol/kg gadoteridol. When findings were negative or equivocal, we injected an additional 0.1-mmol/kg dose of gadoteridol and obtained PWI and second postcontrast T1-weighted images. We used a 3-point scale to grade perfusion maps and TCMRA and assessed whether these techniques added information to conventional MR imaging in the differential diagnosis. We also evaluated whether the second contrast injection improved the conspicuity and/or number of enhancing lesions and used a 4-point scoring system to quantitatively analyze diagnostic yield of TCMRA and PWI.
We could assess tumor hemodynamics on PWI maps and TCMRA images in all 69 patients. In 14 cases (20%), PWI and/or TCMRA added information to conventional MR findings. After second injection of contrast medium, lesion conspicuity improved in 58 of the 69 cases (84%), and the number of detected lesions increased in 11 of 31 cases diagnosed with metastatic disease (36%). Quantitative analysis revealed TCMRA and PWI provided significant additional diagnostic information (Kruskal-Wallis test, P<0.0001).
Consecutive acquisition of TCMRA and PWI using supplementary contrast injection can facilitate differential diagnosis of suspected brain metastasis and improve the number and conspicuity of detected lesions.
时间分辨对比增强磁共振（MR）血管造影（TCMRA）和灌注 MR 成像（PWI）已用于评估脑肿瘤的血液动力学。我们评估了在补充钆基造影剂注射后连续进行这些技术以评估疑似脑转移的可行性和价值。
在 69 例疑似脑转移患者中，我们获得了预对比 MR 图像，然后在给予 0.1mmol/kg 钆特醇后进行 TCMRA 和对比后 T1 加权图像。当结果为阴性或不确定时，我们注射了另外 0.1mmol/kg 的钆特醇剂量，并获得了 PWI 和第二次对比后 T1 加权图像。我们使用 3 分制评分来分级灌注图和 TCMRA，并评估这些技术在鉴别诊断中是否增加了常规 MR 成像的信息。我们还评估了第二次对比注射是否提高了增强病变的显影度和/或数量，并使用 4 分制评分系统对 TCMRA 和 PWI 的诊断收益进行定量分析。
我们能够在所有 69 例患者的 PWI 图和 TCMRA 图像上评估肿瘤血液动力学。在 14 例（20%）中，PWI 和/或 TCMRA 增加了常规 MR 发现的信息。在第二次注射对比剂后，69 例中的 58 例（84%）病变显影度改善，31 例诊断为转移性疾病的患者中 11 例（36%）检测到的病变数量增加。定量分析显示 TCMRA 和 PWI 提供了显著的额外诊断信息（Kruskal-Wallis 检验，P<0.0001）。
使用补充对比剂连续采集 TCMRA 和 PWI 可以促进疑似脑转移的鉴别诊断，并提高检测到的病变的数量和显影度。
