Hi Yizhou,
I don’t use this forum frequently anymore these days; somebody highlighted your question directly to me just now. As the work indeed states and cites:
As detailed in Aerts et al. (2019), we overcame this by gradually reducing the FOD amplitude threshold close to and even more so within the tumor, based on its prior segmentation obtained registering the T1-weighted image to the diffusion data, further spatially smoothed using a Gaussian kernel with a standard deviation of 3 mm to introduce a smooth boundary extending slightly beyond – as well as within – the edges of the tumor.
For scientific reference, that’s this source (Aerts et al., 2019): Evaluating the performance of 3-tissue constrained spherical deconvolution pipelines for within-tumor tractography. (https://doi.org/10.1101/629873)
@Hannelore_Aerts and myself developed this solution. Hannelore left active research upon finishing her PhD, so we didn’t get round to get this fully out at the time. The same observations will make it into another published work though; no worries.
In any case, I can directly help you with the approach if you wish. It requires some careful QA in the process. From a first look at your screenshots and the description you provide, it should be suitable in your specific setting. Just drop me an email if you’re interested.
Cheers,
Thijs