estimated SNR was caculated for four b values(0,200,400, and 800 s/mm2) as mean SI o f all ROIs divided by standard deviation of black ground noise (measured on a smll ROI outside the signal region).
P 12, 13 - conclusion that more averages should be collected at low b-values because they are "more important" This reasoning is flawed since the lower b-values are necessary to capture the microcirculation perfusion information. The number of averages may be less important since the SNR is higher at low b-values.
Related, the conclusion (on p 13) that the influence of NEX on IVIM is not important is not necessarily correct since it might be important at high b-values, but this wasn't tested.
结论是，应该在较低的b值下收集更多的平均值，因为它们“更重要”。 这种推理是有缺陷的，因为较低的b值是捕获微循环灌注信息所必需的。 平均数可能不太重要，因为SNR在低b值时更高。
相关的，（第13页）NEX对IVIM的影响不重要的结论不一定正确，因为它在高b值时可能很重要，但是没有测试。
Since the IVIM effect is usually small, more images are often acquired at low b values than for diffusion at high b values
由于IVIM效应通常较小，因此通常在低b值下较高b值需要获得的图像
for minimizing the bias due to inconsistent ROI locations, we drew ROI at the same level and in one slice to calculate the IVIM parameters in all subjects.
As shown in Fig 2, the gray matter and white matter boundaries are clearly delineated, on the DW image (b=1000 s/mm2). We noticed that the red area or fast diffusion effect caused by a larger blood vessel (including the cortical vessels) was demonstrated in brain tissue on pseudodiffusion maps at the 500 s/mm2 b-value (Fig 3 a1 and a2). Subsequent adjustments of ROI may be made after the ROI is delineated based on DW and pseudodiffusion maps, to avoid including the larger blood vessels in the ROI. Therefore, we draw the cortical ROI in the GM and avoid cortical vessels as much as possible.
In addition, compared with body organs, the pseudo-diffusion map of the brain tissue is relatively good in quality and has a relatively high signal-to-noise ratio.
We have edited our manuscript extensively and improved the language usage and fluency with the help of "English Edit", including some minor grammar errors.
We have revised the relevant sentences according to your comments.
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