Journal of radiological science and technology (대한방사선기술학회지:방사선기술과학)

Korean Society of Radiological Science (대한방사선과학회)
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Optimal Flip Angle for T2-Weighted Effect in Micro 4.7T MRI SE Sequence

마이크로 4.7T MRI SE Sequence에서 T2강조효과를 위한 최적의 Flip Angle

  • Lee, Sang-Ho (Dept. of Radiological science, Jeonju University)
  • 이상호 (전주대학교 방사선학과)
  • Received : 2019.04.19
  • Accepted : 2019.04.28
  • Published : 2019.04.30
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Abstract

The purpose of this study was to investigate the FA value which can produce the best T2-weighted images by measuring the signal intensity and noise according to the FA value change in the brain image and the abdominal image of the mouse using micro-MRI. Brain imaging and abdominal imaging of BALB / C mice weighing 20g were performed using 4.7T (Bruker BioSpin MRI GmbH) micro-MRI equipment, Turbo RARE-T2 (spin echo-T2) images were scanned at TR 3500 msec and TE 36 msec. The changes of the FA values were $60^{\circ}$, $80^{\circ}$, $100^{\circ}$, $120^{\circ}$, $140^{\circ}$, $160^{\circ}$ and $180^{\circ}$. We measured signal intensity according to FA values of ventricle and thalamus in brain imaging, The signal intensity of kidney and muscle around the kidney was measured in abdominal images. To obtain SNR and CNR, we measured the background signals of two different parts, not the tissue. In the brain (thalamus) image, the signal intensity of FA $100^{\circ}$ was 7,433 and SNR (6.49) was the highest. In the abdominal (kidney) image, the signal intensity was highest at 16,523 when FA was $120^{\circ}$, and the highest SNR was 8.54 when FA was $140^{\circ}$. The CNR value of the brain image was 1.38 at FA $60^{\circ}$ and gradually increased to 8.29 at FA $180^{\circ}$. The CNR value of the muscle adjacent to the kidney gradually increased from 2.36 when the FA value was $60^{\circ}$ and the highest value was 4,57 at the FA value $180^{\circ}$.

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