I’m currently developing a project using open source ImageJ software to measure pulmonary vessel volume and prognosticate outcomes in patients with pulmonary fibrosis. I have been trying to follow the Matsuoka et al. protocol described in the literature (pertinent screenshot attached) however I have run into an issue which I have not been able to solve by myself or with my own resources.
The protocol calls for thresholding measured in HU (e.g. “Set Lower Threshold to -1024, Upper Threshold to -500”). Unfortunately within ImageJ thresholding is not measured in Hounsfield units, and setting negative thresholds are not possible. A similar issue arises when I try “windowing” - the images are supposed to be windowed at -720 HU however again that is not the scale provided by the software for my use.
I’m certain our issue is in my own understanding of how to use ImageJ and the biomedical imaging software. I have seen similar questions posted however have not found useful answers in the past. Any help is much appreciated