Imaging efficiency and contrast enhancement in the fast gradient refocusing technique
The gradient recalled (refocused) echo technique produces images in very short scanning time. The signal to noise/unit time of the image is slightly better at small flip angles, provided Tl is estimated carefully. A short TR without dead space at low flip angles allows acquisition of high resolution 3D contiguous volume data within a few minutes. The gradient refocusing technique, however, can produce image artifacts due to uncompensated gradient induced phase shifts. The use of phase encoding gradient reversal removes the artifact, but also introduces signal dependence on transverse magnetization, which results in reduced tissue contrast. In this work the authors demonstrate that by inserting a strong gradient at the end of the pulse sequence in the slice encoding direction, tissue contrast is restored to the original level with the absence of phase artifact.
- Research Organization:
- Los Alamos/UNM Center for Non-Invasive Diagnosis, Univ. of New Mexico School of Medicine, Albuquerque, NM 87131
- OSTI ID:
- 5518990
- Journal Information:
- IEEE Trans. Nucl. Sci.; (United States), Vol. NS-34:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
IMAGE SCANNERS
PERFORMANCE
RESOLUTION
EFFICIENCY
FOCUSING
IMAGE PROCESSING
IMAGE TUBES
MODULATION
NMR IMAGING
PHASE SHIFT
PULSE TECHNIQUES
SIGNAL-TO-NOISE RATIO
TIME RESOLUTION
DIAGNOSTIC TECHNIQUES
PROCESSING
TIMING PROPERTIES
440300* - Miscellaneous Instruments- (-1989)
550601 - Medicine- Unsealed Radionuclides in Diagnostics