摘要
目的探讨我国ＭＲＩ设备的状态检测方法。方法ＭＲＩ设备７台，其中有超低磁场强度电磁型３台，低磁场强度永磁型２台，中、高磁场强度超导型各１台，７台中有二手机１台。状态检测的参数为信噪比、均匀度、线性度、层厚、空间分辨率和低对比度分辨率等６项。用美国体模实验室（ＴｈｅＰｈａｎｔｏｍＬａｂｏｒａｔｏｒｙ）和医学物理学家Ｇｏｏｄｅｎｏｕｇｈ博士研制的Ｍａｇｐｈａｎ体模进行性能参数检测。用随机抽取近２周的头部、胸部、腹部、腰椎的Ｔ１、Ｔ２横断面照片进行临床照片质量评估。照片质量从优到劣分为１、２、３等。结果３台超低磁场电磁型磁共振成像设备的６项参数分别有５项以上不合格，照片质量评估为３等；１台低磁场强度永磁型设备除信噪比不合格外，其余５项参数均合格，照片质量为２等；１台低磁场强度永磁型设备和１台二手中磁场强度超导型设备均有２项参数不合格，其中空间分辨率不合格，照片质量为２等。１台高磁场强度超导型设备６项参数均合格，照片质量为１－等。结论该状态检测方法借鉴了国外的经验，同时又根据实际需要进行补充完善。
Objective To develop the methods of performance testing for magnetic resonance imaging systems in China. Methods 7 units of magnetic resonance imaging systems, including 3 units of ultra low field resistive magnet, 2 unit of low field permanent magnet, one unit of second hand mid field super conductive magnet and one unit of high field super conductive magnet. The measured performance parameters of magnetic resonance imaging system included the signal to noise ratio (SNR), uniformity, linearity, slice thickness, spatial resolution, and low contrast resolution. The Magphan phantom developed by the Phantom Laboratory of USA and medical physicist David Goodenough,Ph.D. was used to measure the performance parameters. The patient images obtained in recent two weeks, included T 1 and T 2 axial images of head, thorax, abdomen and spine arbitrarily taken out for evaluation. The quality of image was assigned into 1,2,3 grades from excellent to poor. Results In the 3 units of ultra low field resistive magnet system, more than 5 performance parameters were below the standard and the quality of image was grade 3. In one unit of low field strength permanent magnet system except SNR, the other 5 parameters fulfilled the standard, and the quality of image was grade 2. In one unit of low field permanent magnet system, and one unit of mid field super conductive magnet system, two parameters including spatial resolution failed to meet the standard, and the quality of image was grade 2. In one unit of high field super conductive magnet system, all the parameters were in accordance with the standard and the quality of image was grade 1. Conclusions The method of performance testing for magnetic resonance imaging systems was developed by making use of existing experiences in foreign countries and adding some new contents as needed in clinical practice. The method provides the performance evaluation of magnetic resonance imaging system.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
1999年第2期131-135,共5页
Chinese Journal of Radiology
关键词
磁共振成像
质量控制
评价研究
Magnetic resonance imaging Quality control Evaluation studies
