measuring hounsefield units on a CT

Posted by Matthijs E. on Feb 08, 2014; 3:30pm
URL: http://imagej.273.s1.nabble.com/measuring-hounsefield-units-on-a-CT-tp5006460.html

Hi there,

Im new to ImageJ and already I am at a loss of what to do next.

I am a 4th year medical student and i am about to begin with a newly developed research method. My research is about whether abdominal visceral fat does have a prognostic factor regarding the outcome of patients who received colorectal cancer surgery. Compared to the standard BMI-indedx it is believed that a visceral fat index has a better prediction than the BMI on the outcome of the operation. Think about shorter OR-time, decreased blood loss, fewer post-operative complications, fewer anastomotic leakage etc.

The way I will achieve this is by using ImageJ and pre-operative CT's of the pt (transverse plane of the abdomen). For each patient I use one coupe at 3 different levels (e.g. umbilical, spina iliaca and xiphoid) the total amount of the measured visceral fat, based upon the 3 coupes, will give me an index.

Now my problem is as follows. My professor is a busy men, obviously. He told me I should get to know the program, find a way to use ImageJ and then come back to him. Easier said than done. Hence, I seek the help of you.

The idea is, that based upon the Hounsefield Units, I can differentiate between muscle, fat, visceral fat and other tissues. Previous studies have shown that I should look at a HU range of - 130HU and -90HU in order to find visceral fat. The total amount of visceral fat will eventually give me the index I need.

According to my professor this could be easily done with ImageJ, yet he did not know how. That was my task to find out.

Does anyone know how to achieve this? I found some tutorials but I am not sure whether this is what I need. ImageJ has literally an endless amount of options and plugins. (tutorial: http://www.unige.ch/medecine/bioimaging/tricks/imagejtutorials/Quantification.pdf)

This might sound a little vague, hopefully somebody understands what I mean!

Thanks in advance,

Matthijs