Clark Daniel James, Smith Alex K, Dortch Richard D, Knopp Michael V, Smith Seth A
Department of Radiology, The Ohio State University, Columbus, Ohio, USA.
Wright Center of Innovation, The Ohio State University, Columbus, Ohio, USA.
Magn Reson Med. 2016 Sep;76(3):826-37. doi: 10.1002/mrm.25987. Epub 2015 Sep 28.
To develop a chemical exchange saturation transfer (CEST) scheme sensitive to hydroxyl protons at 3 T. Clinical imaging of hydroxyl moieties can have an impact on osteoarthritis, neuropsychiatric disorders, and cancer.
By varying saturation amplitude linearly with frequency offset, the direct water saturation component of the Z-spectrum is flattened and can be subtracted to produce a magnetization transfer ratio difference spectrum (MTRdiff ) that isolates solute resonances. Variable saturation power allows for near optimization of hydroxyl and amine/amide moieties in one Z-spectrum.
Phantom studies were used to test vCEST performance in two environments: (1) aqueous single-solute (glycogen, glucose); (2) aqueous multiple solute (glycogen with bovine serum albumin). In vivo vCEST imaging of glycosaminoglycan content in patellar-femoral cartilage was performed in a subject with history of cartilage transplant.
In solutions with overlapping resonances, vCEST resolves separate hydroxyl and amine/amide peaks. CEST hydroxyl signal in cartilage is negligible, but with vCEST, hydroxyl signal ranged from 2 to 5% ppm and showed distinct contrast between lesions and normal appearing cartilage.
Introduced a variable saturation amplitude CEST (vCEST) scheme to improve sensitivity to exchangeable hydroxyl moieties at 3 T resulting in detection of hydroxyl in the presence of multiple solutes with overlapping resonances. Magn Reson Med 76:826-837, 2016. © 2015 Wiley Periodicals, Inc.
开发一种对3T场强下羟基质子敏感的化学交换饱和转移（CEST）方案。羟基部分的临床成像可能对骨关节炎、神经精神疾病和癌症产生影响。
通过使饱和幅度随频率偏移线性变化，Z谱的直接水饱和成分被平坦化，并且可以被减去以产生分离溶质共振的磁化转移率差异谱（MTRdiff）。可变饱和功率允许在一个Z谱中对羟基和胺/酰胺部分进行近乎优化。
使用体模研究在两种环境中测试可变翻转角CEST（vCEST）性能：（1）水性单溶质（糖原、葡萄糖）；（2）水性多溶质（糖原与牛血清白蛋白）。在一名有软骨移植病史的受试者中对髌股关节软骨中的糖胺聚糖含量进行了体内vCEST成像。
在具有重叠共振的溶液中，vCEST分辨出单独的羟基和胺/酰胺峰。软骨中的CEST羟基信号可忽略不计，但使用vCEST时，羟基信号范围为2至5% ppm，并且在病变与正常外观软骨之间显示出明显的对比度。
引入了可变饱和幅度CEST（vCEST）方案，以提高对3T场强下可交换羟基质子的敏感性，从而在存在具有重叠共振的多种溶质的情况下检测到羟基。《磁共振医学》76:826 - 837, 2016。© 2015威利期刊公司。
