Adjei O N, Sugimura H, Tamura S, Shimizu T, Kihara Y, Kakitsubata S, Kakitsubata Y, Watanabe K
Department of Radiology, Miyazaki Medical College, Japan.
Radiat Med. 1996 Jul-Aug;14(4):179-83.
The purpose of this study was to evaluate the effects of selected parameters in a conventional spin-echo MRI sequence on image quality in a phantom undergoing periodic motion.
Images of a composite oil/copper sulfate phantom moving in a 1.5 Tesla magnet were acquired. The CuSO4 ghost signal-to-noise ratio (SNR) and distances between corresponding points on the phantom image and adjacent ghosts were evaluated.
Increasing time to repeat (TR) and number of acquisitions (NAq) improved image quality. Ghost SNR was near unity at TR = 500 msec and at NAq around 4. Increasing TR and NAq resulted in increased distance between images. The effects of field of view (FOV) and matrix size on image quality were relatively less significant.
Increasing NAq appeared to have a comparatively greater effect on ghost SNR and image quality under our experimental conditions. However, the effect of increasing NAq on image quality appeared to be definite since a saturation point was reached after a particular NAq. Increasing NAq above this point resulted in a relatively smaller improvement in image quality.
本研究的目的是评估传统自旋回波MRI序列中选定参数对周期性运动模型图像质量的影响。
采集在1.5特斯拉磁体中移动的复合油/硫酸铜模型的图像。评估了硫酸铜伪影的信噪比（SNR）以及模型图像上对应点与相邻伪影之间的距离。
增加重复时间（TR）和采集次数（NAq）可提高图像质量。在TR = 500毫秒且NAq约为4时，伪影SNR接近1。增加TR和NAq会导致图像之间的距离增加。视野（FOV）和矩阵大小对图像质量的影响相对较小。
在我们的实验条件下，增加NAq似乎对伪影SNR和图像质量有相对更大的影响。然而，增加NAq对图像质量的影响似乎是有限的，因为在特定的NAq之后会达到饱和点。超过这一点增加NAq会导致图像质量的改善相对较小。
