From the Departments of *Radiology, and †Preventive Medicine, Northwestern University; ‡Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL; §Department of Radiology, Xijing Hospital, The Fourth Military Medical University, Peking Union Medical College, Xi'an, Shaangxi; ∥Department of Radiology, Anzhen Hospital, Capital Medical University; and ¶Department of Radiology, Peking Union Medical College Hospital, Beijing, China.
Invest Radiol. 2014 Apr;49(4):243-8. doi: 10.1097/RLI.0000000000000024.
The objective of this study was to assess the evolution of T1 contrast (T1c) between cardiovascular tissues, contrast agents, and magnetic field strengths.
This Health Insurance Portability and Accountability Act-compliant study was approved by the institutional review board, and written informed consent was obtained from all participants. Eight healthy volunteers were recruited to undergo 4 consecutive magnetic resonance (MR) scans with the same imaging parameters. Scans 1 and 2 were performed using a 3-T MR scanner, and scans 3 and 4 were performed using a 1.5-T MR scanner. Gadofosveset trisodium (0.03 mmol/kg) was injected for scans 1 and 3, and gadopentetate dimeglumine (Gd-DTPA) (0.1 mmol/kg) was used for scans 2 and 4. Modified Look-Locker inversion recovery T1 maps with a midventricular short-axis view were acquired before contrast and repeated every 5 minutes until 45 minutes after contrast agent administration. T1 contrast tissue (T1(myocardium) - T1(blood)), T1c agent (T1Gd-DTPA - T1(Gadofosveset)), and T1c field (T1(3T) - T1(1.5T)) were calculated and compared using t tests.
The T1c tissue of the 3-T scanner was larger than that of the 1.5-T scanner for both contrast agents. In both the myocardium and the blood pool, the T1c agent of the 1.5-T scanner was larger than that of the 3-T scanner. Gadofosveset trisodium exhibited a larger T1c field and T1c tissue than did Gd-DTPA. The T1c tissue induced by Gd-DTPA diminished faster than that induced by gadofosveset trisodium at both 1.5 and 3 T.
Our study demonstrates the independent effects of timing, contrast agent type, and magnetic field strength on postcontrast T1c under general physiological conditions. The behaviors of T1c can be used to tailor quantitative MR imaging protocols for various clinical purposes.
本研究旨在评估心血管组织、对比剂和磁场强度的 T1 对比（T1c）演变。
这项符合《健康保险流通与责任法案》的研究得到了机构审查委员会的批准，并获得了所有参与者的书面知情同意。招募了 8 名健康志愿者进行 4 次具有相同成像参数的磁共振（MR）扫描。扫描 1 和 2 在 3T MR 扫描仪上进行，扫描 3 和 4 在 1.5T MR 扫描仪上进行。分别在扫描 1 和 3 时注射钆福司赛三钠（0.03mmol/kg），在扫描 2 和 4 时注射钆喷酸葡胺（Gd-DTPA）（0.1mmol/kg）。在注射对比剂前获得中室短轴视图的改良 Look-Locker 反转恢复 T1 图，并在注射对比剂后每隔 5 分钟重复，直到 45 分钟。使用 t 检验比较 T1 组织对比（T1（心肌）-T1（血液））、T1c 对比剂（T1Gd-DTPA-T1（钆福司赛三钠））和 T1c 场（T1（3T）-T1（1.5T））。
两种对比剂的 3T 扫描仪的 T1c 组织大于 1.5T 扫描仪。在心肌和血池中，1.5T 扫描仪的 T1c 对比剂大于 3T 扫描仪。钆福司赛三钠的 T1c 场和 T1c 组织大于 Gd-DTPA。在 1.5 和 3T 时，Gd-DTPA 诱导的 T1c 组织衰减速度快于钆福司赛三钠。
本研究表明，在一般生理条件下，时间、对比剂类型和磁场强度对对比后 T1c 具有独立影响。T1c 的行为可用于针对各种临床目的定制定量磁共振成像协议。
