Akio Ogura1, Daisuke Koyama2, Norio Hayashi1, Isamu Hatano3, Kohki Osakabe4, Natsumi Yamaguchi5. 1. 1 Graduate School, Gunma Prefectural College of Health Sciences, 323-1, Kamioki-machi, Maebashi, Gunma, Japan. 2. 2 Department of Radiology, National Hospital Organization Matsumoto Medical Center, Matsumoto, Japan. 3. 3 Department of Radiology, Jichi Medical University Hospital, Tochigi-ken, Japan. 4. 4 Department of Radiology, Gunma Saiseikai Maebashi Hopital, Gunma, Japan. 5. 5 Department of Radiology, Tokyo Metropolitan Tama Medical Center, Tokyo, Japan.
Abstract
OBJECTIVE: The purpose of this study was to investigate the optimal b values required for the generation of computed high-b-value DW images. SUBJECTS AND METHODS: Brain DWI was performed for eight subjects using 16 b values, ranging from 0 s/mm(2) to 5000 s/mm(2). The fractional value as the turning point between the fast and slow components was determined using a diffusion decay curve. Image contrast in the white matter, gray matter, thalamus, putamen, and lateral ventricle was compared between the acquired high-b-value images and the computed high-b-value images derived from various b value images. In addition, the signal-to-noise ratio of each computed image and acquired image was measured and compared. RESULTS: The fractional values obtained from the diffusion decay curve were between 1200 and 1800 s/mm(2). Image contrast in all regions was nearly equivalent between the acquired and computed high-b-value images when b values higher than the fractional value were used, whereas image contrast was significantly different between the two sets of images when b values lower than the fractional value were used (p < 0.05). The computed images derived from low-b-value images showed a higher signal-to-noise ratio, compared with the acquired images. CONCLUSION: Optimal b values should be considered when acquiring images for the derivation of computed DW images.
OBJECTIVE: The purpose of this study was to investigate the optimal b values required for the generation of computed high-b-value DW images. SUBJECTS AND METHODS: Brain DWI was performed for eight subjects using 16 b values, ranging from 0 s/mm(2) to 5000 s/mm(2). The fractional value as the turning point between the fast and slow components was determined using a diffusion decay curve. Image contrast in the white matter, gray matter, thalamus, putamen, and lateral ventricle was compared between the acquired high-b-value images and the computed high-b-value images derived from various b value images. In addition, the signal-to-noise ratio of each computed image and acquired image was measured and compared. RESULTS: The fractional values obtained from the diffusion decay curve were between 1200 and 1800 s/mm(2). Image contrast in all regions was nearly equivalent between the acquired and computed high-b-value images when b values higher than the fractional value were used, whereas image contrast was significantly different between the two sets of images when b values lower than the fractional value were used (p < 0.05). The computed images derived from low-b-value images showed a higher signal-to-noise ratio, compared with the acquired images. CONCLUSION: Optimal b values should be considered when acquiring images for the derivation of computed DW images.
Entities:
Keywords:
biexponential decay; computed DWI; image contrast; optimal b value; signal-to-noise ratio
Authors: Yin Xi; Alexander Liu; Franklin Olumba; Parker Lawson; Daniel N Costa; Qing Yuan; Gaurav Khatri; Takeshi Yokoo; Ivan Pedrosa; Robert E Lenkinski Journal: Quant Imaging Med Surg Date: 2018-07