Wilhelm T, Bachert P
Abteilung Biophysik und Medizinische Strahlenphysik, Deutsches Krebsforschungszentrum (dkfz), Heidelberg, D-69120, Germany.
J Magn Reson. 2001 Mar;149(1):126-30. doi: 10.1006/jmre.2001.2288.
Localized phosphorus-31 NMR spectra of human calf muscle in vivo were obtained by means of echo-planar spectroscopic imaging (EPSI) with a 1.5-T whole-body scanner. The technique permits the measurement of two-dimensional 31P SI data at a minimum acquisition time of 2.4 s (8x8 voxels, TR=300 ms). With 9.4 min measurement time (TR=1100 ms, 64 averages) and 25x25x40 mm spatial resolution in vivo the 31P NMR signal-to-noise ratio (S/N) of the phosphocreatine (PCr) resonance was about 45; the multiplets of nucleoside 5'-triphosphates were resolved. Spectral quality permits quantitative assessment of the PCr signal in a measurement time that is shorter by a factor of 2 or more than the minimum measurement time feasible with chemical-shift imaging. In a functional EPSI study with a time resolution of 20.5 s on the calf muscle of volunteers, spectra showed a 40% decrease of the PCr signal intensity (at rest: S/N congruent with12) upon exertion of the muscle.
利用1.5-T全身扫描仪，通过回波平面光谱成像（EPSI）获得了人体小腿肌肉的局部磷-31核磁共振谱。该技术允许在最短采集时间2.4秒（8×8体素，TR = 300毫秒）内测量二维31P SI数据。在体内测量时间为9.4分钟（TR = 1100毫秒，64次平均）且空间分辨率为25×25×40毫米的情况下，磷酸肌酸（PCr）共振的31P核磁共振信噪比（S/N）约为45；核苷5'-三磷酸的多重峰得到了分辨。光谱质量允许在比化学位移成像可行的最短测量时间短2倍或更多倍的测量时间内对PCr信号进行定量评估。在一项对志愿者小腿肌肉进行时间分辨率为20.5秒的功能性EPSI研究中，光谱显示肌肉运动时PCr信号强度降低了40%（静息时：S/N约为12）。
