Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Magn Reson Med. 2010 Jun;63(6):1442-7. doi: 10.1002/mrm.22382.
A new (17)O-labeled blood contrast agent was injected intravenously in control dogs. Electrocardiogram (ECG)-triggered myocardial T(1)rho imaging was performed to obtain spin-locking T(1)rho-weighted myocardial signals for the detection of resultant metabolite H(2) (17)O water in the heart. Bolus and slow injection methods of various doses of the (17)O-labeled and (16)O-labeled agents were carried out in order to evaluate the sensitivity of this method and determine the optimal injection method. Bolus injection provided approximately 1% signal reduction, whereas slow injection with larger amount of agent yielded 11.9 +/- 0.6% signal reduction. Myocardial oxygen consumption rate was determined by a technique to quantify cerebral oxygenation consumption rate previously developed in (17)O brain studies. With either injection method, myocardial oxygen consumption rate at rest was 5.0 - 5.6 micromol/g/min. Therefore, it appears feasible to detect metabolically generated H(2) (17)O water in vivo in the heart, using the (17)O-labeled blood tracer. Myocardial oxygen consumption rate can then be quantified in vivo, which may open new doors for the assessment of myocardial metabolism.
静脉注射一种新型的 (17)O 标记血对比剂，对正常狗进行心电门控心肌 T(1)rho 成像，以获得自旋锁定 T(1)rho 加权心肌信号，检测心脏中代谢产生的 H(2) (17)O 水。为了评估该方法的灵敏度并确定最佳注射方法，进行了各种剂量的 (17)O 标记和 (16)O 标记剂的推注和缓慢注射。推注可使信号降低约 1%，而缓慢注射较大剂量的药物可使信号降低 11.9 +/- 0.6%。心肌耗氧量通过以前在 (17)O 脑研究中开发的定量脑氧耗量的技术来确定。两种注射方法均显示，休息时心肌耗氧量为 5.0-5.6 微摩尔/克/分钟。因此，使用 (17)O 标记的血示踪剂，似乎可以在体内检测到心脏中代谢产生的 H(2) (17)O 水。然后可以在体内定量心肌耗氧量，这可能为评估心肌代谢开辟新的途径。
