采用磁共振1H成像和31P局部谱学对MCF7人类乳腺癌肿瘤在免疫缺陷小鼠中植入的情况下进行非侵入性监测。肿瘤在雌激素依赖性生长和他莫昔芬引起的缓解期间进行跟踪。在他莫昔芬治疗早期，出现增强的坏死，蔓延到大部分肿瘤体积。随后是修复组织的生长和肿瘤的退化。短期他莫昔芬治疗还改变了磷酸代谢物的含量，在治疗前从0.41 +/- 0.15（n = 14）到治疗后4-7天和9-19天的核苷酸三磷酸与无机磷酸比率为1.10 +/- 0.70（n = 8，P小于0.025）和1.75 +/- 0.66（n = 9，P小于0.0002）。这种变化归因于修复组织的生长。结果提供了关于他莫昔芬响应和作用机制的新信息。

Magnetic resonance 1H-imaging and 31P-localized spectroscopy were utilized to monitor, noninvasively, MCF7 human breast cancer tumors implanted in immunodeficient mice. The tumors were followed during estrogen dependent growth and tamoxifen induced remission. Early after tamoxifen administration enhanced necrosis developed, extending to most of the tumor volume. This was followed by growth of repair tissue along with tumor regression. The short-term tamoxifen treatment also modified the content of the phosphate metabolites, increasing the nucleoside triphosphate to inorganic phosphate ratio from 0.41 +/- 0.15 (n = 14) before treatment to 1.10 +/- 0.70 (n = 8, P less than 0.025) and to 1.75 +/- 0.66 (n = 9, P less than 0.0002) 4-7 days and 9-19 days, respectively, after treatment. This change was attributed to the growth of reparative tissue. The results provide new information regarding the response and the mechanism of action of tamoxifen.