Department of Radiology and Biomedical Imaging, University of California, San Francisco, California.
Department of Clinical Pharmacy, University of California, San Francisco, California.
Magn Reson Med. 2018 Nov;80(5):2062-2072. doi: 10.1002/mrm.27179. Epub 2018 Mar 25.
The purpose of this study was to develop a new 3D dynamic carbon-13 compressed sensing echoplanar spectroscopic imaging (EPSI) MR sequence and test it in phantoms, animal models, and then in prostate cancer patients to image the metabolic conversion of hyperpolarized [1- C]pyruvate to [1- C]lactate with whole gland coverage at high spatial and temporal resolution.
A 3D dynamic compressed sensing (CS)-EPSI sequence with spectral-spatial excitation was designed to meet the required spatial coverage, time and spatial resolution, and RF limitations of the 3T MR scanner for its clinical translation for prostate cancer patient imaging. After phantom testing, animal studies were performed in rats and transgenic mice with prostate cancers. For patient studies, a GE SPINlab polarizer (GE Healthcare, Waukesha, WI) was used to produce hyperpolarized sterile GMP [1- C]pyruvate. 3D dynamic C CS-EPSI data were acquired starting 5 s after injection throughout the gland with a spatial resolution of 0.5 cm , 18 time frames, 2-s temporal resolution, and 36 s total acquisition time.
Through preclinical testing, the 3D CS-EPSI sequence developed in this project was shown to provide the desired spectral, temporal, and spatial 5D HP C MR data. In human studies, the 3D dynamic HP CS-EPSI approach provided first-ever simultaneously volumetric and dynamic images of the LDH-catalyzed conversion of [1- C]pyruvate to [1- C]lactate in a biopsy-proven prostate cancer patient with full gland coverage.
The results demonstrate the feasibility to characterize prostate cancer metabolism in animals, and now patients using this new 3D dynamic HP MR technique to measure k , the kinetic rate constant of [1- C]pyruvate to [1- C]lactate conversion.
本研究旨在开发一种新的三维动态碳-13 压缩感知磁共振波谱成像（EPSI）MR 序列，并在体模、动物模型中进行测试，然后在前列腺癌患者中进行测试，以高时空分辨率对整个腺体进行覆盖，对超极化[1-C]丙酮酸向[1-C]乳酸的代谢转化进行成像。
设计了一种三维动态压缩感知（CS）-EPSI 序列，具有谱-空间激发功能，以满足临床转化为前列腺癌患者成像所需的空间覆盖、时间和空间分辨率以及 3T MR 扫描仪的射频限制。在进行体模测试后，在患有前列腺癌的大鼠和转基因小鼠中进行了动物研究。对于患者研究，使用 GE SPINlab 极化器（GE Healthcare，威斯康星州沃基肖）产生超极化无菌 GMP[1-C]丙酮酸。在注射后 5 秒开始，通过整个腺体采集三维动态 C CS-EPSI 数据，空间分辨率为 0.5cm，18 个时间帧，2 秒时间分辨率，总采集时间为 36 秒。
通过临床前测试，本项目中开发的三维 CS-EPSI 序列能够提供所需的光谱、时间和空间 5D HP C MR 数据。在人体研究中，三维动态 HP CS-EPSI 方法首次提供了在活检证实的前列腺癌患者中，LDH 催化的[1-C]丙酮酸向[1-C]乳酸转化的容积和动态图像，实现了整个腺体的全覆盖。
结果表明，使用这种新的三维动态 HP MR 技术来测量 k，即[1-C]丙酮酸向[1-C]乳酸转化的动力学速率常数，在动物和现在的患者中对前列腺癌代谢进行特征描述是可行的。
