Medical Physics Unit, Azienda USL - IRCCS, Reggio Emilia, Italy.
Medical Physics Unit, Ospedale San Giovanni Calibita Fatebenefratelli, Roma, Italy.
Phys Med. 2018 Oct;54:49-55. doi: 10.1016/j.ejmp.2018.08.013. Epub 2018 Sep 28.
The aim of this study was to propose and validate across various clinical scanner systems a straightforward multiparametric quality assurance procedure for proton magnetic resonance spectroscopy (MRS).
Eighteen clinical 1.5 T and 3 T scanner systems for MRS, from 16 centres and 3 different manufacturers, were enrolled in the study. A standard spherical water phantom was employed by all centres. The acquisition protocol included 3 sets of single (isotropic) voxel (size 20 mm) PRESS acquisitions with unsuppressed water signal and acquisition voxel position at isocenter as well as off-center, repeated 4/5 times within approximately 2 months. Water peak linewidth (LW) and area under the water peak (AP) were estimated.
LW values [mean (standard deviation)] were 1.4 (1.0) Hz and 0.8 (0.3) Hz for 3 T and 1.5 T scanners, respectively. The mean (standard deviation) (across all scanners) coefficient of variation of LW and AP for different spatial positions of acquisition voxel were 43% (20%) and 11% (11%), respectively. The mean (standard deviation) phantom Tvalues were 1145 (50) ms and 1010 (95) ms for 1.5 T and 3 T scanners, respectively. The mean (standard deviation) (across all scanners) coefficients of variation for repeated measurements of LW, AP and T were 25% (20%), 10% (14%) and 5% (2%), respectively.
We proposed a straightforward multiparametric and not time consuming quality control protocol for MRS, which can be included in routine and periodic quality assurance procedures. The protocol has been validated and proven to be feasible in a multicentre comparison study of a fairly large number of clinical 1.5 T and 3 T scanner systems.
本研究旨在针对质子磁共振波谱(MRS)提出并验证一种适用于各种临床扫描仪系统的简单多参数质量保证程序。
本研究共纳入了来自 16 个中心和 3 个不同制造商的 18 台临床 1.5T 和 3T 磁共振波谱扫描仪系统。所有中心均采用标准球形水模体。采集方案包括 3 组具有未抑制水信号的单(各向同性)体素(大小 20mm)PRESS 采集,采集体素位置位于等中心以及偏心位置,在大约 2 个月内重复 4/5 次。测量水峰线宽(LW)和水峰下面积(AP)。
3T 和 1.5T 扫描仪的 LW 值[平均值(标准差)]分别为 1.4(1.0)Hz 和 0.8(0.3)Hz。LW 和 AP 在不同采集体素空间位置的变异系数(across all scanners)平均值(标准差)分别为 43%(20%)和 11%(11%)。1.5T 和 3T 扫描仪的水模 T 值[平均值(标准差)]分别为 1145(50)ms 和 1010(95)ms。LW、AP 和 T 的重复测量的变异系数平均值(across all scanners)分别为 25%(20%)、10%(14%)和 5%(2%)。
我们提出了一种简单的多参数且不耗时的 MRS 质量控制方案,可以纳入常规和定期质量保证程序。该方案已经在一项涉及相当数量的临床 1.5T 和 3T 扫描仪系统的多中心比较研究中得到验证和证明是可行的。