Motion related artifacts in spin-echo MR imaging: effects of sequence parameters on image quality at 1.5 Tesla.
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Department of Radiology, Miyazaki Medical College, Japan.
O N
ON
Adjei
H
H
Sugimura
S
S
Tamura
T
T
Shimizu
Y
Y
Kihara
S
S
Kakitsubata
Y
Y
Kakitsubata
K
K
Watanabe
D016477:Artifacts; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods* / Q000592:standards; D009038:Motion; D019047:Phantoms, Imaging