Soares J C, Boada F, Spencer S, Mallinger A G, Dippold C S, Wells K F, Frank E, Keshavan M S, Gershon S, Kupfer D J
Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
Biol Psychiatry. 2001 Mar 1;49(5):437-43. doi: 10.1016/s0006-3223(00)00985-9.
This study was conducted to investigate the feasibility of human brain (7)Li MRS investigations at a high magnetic field (3 T), and to further explore the relationship between brain and serum lithium measures in lithium-treated bipolar patients.
Eight bipolar disorder type I patients (5 males, 3 females; mean age +/- SD = 33 +/- 9 years) were studied. A 3-T scanner, using a dual-tuned ((1)H and (7)Li) echoplanar imaging (EPI) compatible radiofrequency (RF) birdcage coil was used. (7)Li magnetic resonance spectroscopy (MRS) signal was acquired at the frequency of 49.64 MHz using an imaging selective in vivo spectroscopy (ISIS) sequence (TR = 15 sec, 128 averages), and quantitation was obtained in reference to an external standard.
The mean +/- SD oral lithium dose was 1265 +/- 442 mg/day, and the mean +/- SD 12-hour serum level was 0.69 +/- 0.19 mEq/L. The measured brain lithium concentrations varied from 0.23 to 0.55 mEq/L (mean +/- SD = 0.35 +/- 0.11 mEq/L). The brain-serum ratios varied from 0.30 to 0.80 (mean +/- SD = 0.52 +/- 0.16). Subjects on single daily doses of lithium at bedtime (n = 5) had higher brain-serum lithium ratios compared with those on twice-a-day schedules (n = 3) (0.61 +/- 0.12 and 0.37 +/- 0.07, respectively; Mann--Whitney U test, Z = -2.24, p =.03).
This study demonstrated for the first time the feasibility of (7)Li MRS human studies at 3 T. Future studies should examine a possible role for this methodology in investigations of lithium refractoriness and prediction of treatment outcome in bipolar patients.
本研究旨在探讨在高磁场（3T）下进行人脑锂磁共振波谱（MRS）研究的可行性，并进一步探究锂治疗双相情感障碍患者时脑内锂含量与血清锂含量之间的关系。
对8例I型双相情感障碍患者（5例男性，3例女性；平均年龄±标准差 = 33±9岁）进行研究。使用一台3T扫描仪，配备一个双调谐（氢和锂）回波平面成像（EPI）兼容的射频（RF）鸟笼式线圈。采用成像选择活体波谱（ISIS）序列（重复时间 = 15秒，128次平均采集）在49.64MHz频率下采集锂磁共振波谱（MRS）信号，并参照外标进行定量分析。
口服锂盐的平均剂量±标准差为1265±442mg/天，12小时血清锂平均水平±标准差为0.69±0.19mEq/L。测得的脑内锂浓度在0.23至0.55mEq/L之间（平均±标准差 = 0.35±0.11mEq/L）。脑 - 血清比值在0.30至0.80之间（平均±标准差 = 0.52±0.16）。每日睡前单次服用锂盐的受试者（n = 5）与每日服用两次锂盐的受试者（n = 3）相比，脑 - 血清锂比值更高（分别为0.61±0.12和0.37±0.07；曼 - 惠特尼U检验，Z = -2.24，p = 0.03）。
本研究首次证明了在3T磁场下进行锂磁共振波谱人体研究的可行性。未来的研究应探讨该方法在双相情感障碍患者锂抵抗研究及治疗结果预测中的潜在作用。
