Komoroski R A, Newton J E, Cardwell D, Sprigg J, Pearce J, Karson C N
Department of Radiology, University of Arkansas for Medical Sciences, Little Rock 72205.
Magn Reson Med. 1994 Feb;31(2):204-11. doi: 10.1002/mrm.1910310214.
Fluorine-19 NMR spectroscopy was used to monitor the anti-depressant drug fluoxetine (and its metabolite norfluoxetine) in vivo in human brain. A quadrature birdcage head coil, developed for operation at 60.1 MHz, yielded a signal from the head 2 to 4 times stronger than for surface coils. It was used to measure the in vivo 19F spin-lattice relaxation time (T1) of fluoxetine for five patients by the inversion-recovery technique. The individual T1s varied from 149 to 386 ms, which was attributed in part to interindividual differences based on the reproducibility of a phantom T1. The individual T1 correlated weakly with approximate brain concentration. A lower limit of 3 to 4 ms was found for the spin-spin relaxation time from line width measurements. Low resolution 4-dimensional spectroscopic imaging confirmed that the single in vivo 19F resonance for fluoxetine arose primarily from brain. The spectrum of a cerebral hemisphere (in formalin) obtained at autopsy from a patient on 40 mg/day of fluoxetine for 19 weeks was comparable with that seen for patients in vivo. The in vivo signal arose about equally from fluoxetine and the active metabolite norfluoxetine, as demonstrated by the in vitro 19F NMR spectrum of the lipophilic extract of a small section of brain. In vitro quantitation of frozen samples from three brain regions yielded combined fluoxetine/norfluoxetine concentrations of 12.3 to 18.6 micrograms/ml, which is higher than typically determined in vivo, and suggests that the fluorinated drugs may not be 100% visible in vivo.
氟-19核磁共振光谱法被用于在人脑活体中监测抗抑郁药物氟西汀（及其代谢物去甲氟西汀）。一个为在60.1兆赫兹运行而研发的正交鸟笼式头部线圈，产生的来自头部的信号比表面线圈强2至4倍。它被用于通过反转恢复技术测量5名患者体内氟西汀的19F自旋晶格弛豫时间（T1）。个体T1值在149至386毫秒之间变化，部分归因于基于体模T1可重复性的个体间差异。个体T1与大致脑浓度的相关性较弱。通过线宽测量发现自旋-自旋弛豫时间的下限为3至4毫秒。低分辨率四维光谱成像证实，氟西汀在体内的单一19F共振主要源于大脑。从一名服用40毫克/天氟西汀19周的患者尸检获得的（用福尔马林固定的）大脑半球光谱与体内患者所见光谱相当。如一小段脑的亲脂提取物的体外19F核磁共振光谱所示，体内信号大约同等程度地来自氟西汀和活性代谢物去甲氟西汀。对来自三个脑区的冷冻样品进行体外定量分析，得出氟西汀/去甲氟西汀的组合浓度为12.3至18.6微克/毫升，这高于通常在体内测定的浓度，表明氟化药物在体内可能并非100%可见。
