How to compare CT scans
Posted: Fri Apr 13, 2012 7:51 pm
The ASPS mets can grow very slowly, much slower than most other cancer/sarcoma mets, and the changes might be not registered by even a very experiences radiologists, so the situation will be reported as stable even if it is not. To detect the growth in ASPS, the scan have to be compared with the sufficient interval in between them - a year or even few years. Ivan had detected the growth by himself in the cases when our radiologists stated that the situation is stable because the growth was only 1 mm a year and for the radiologist it is a statistically insignificant consistent with the standard deviation of the device, but when Ivan compared it over 4 years, the growth was 4 mm (roughly from 6 mm to 10 mm) which is already significant to report a growth and start planning what to do about this particular nodule, because 10 mm is the most optimal size for the local ablations.
There is his tip as how to compare the scans that are often done on the different CT scan units. He downloaded a free software to view the scans (http://www.microdicom.com/) in order to be able to compare them more consistently. The problem is that scans from different machines come with different versions of eFilm Lite, which renders the image differently and makes comparison inexact and this software overcomes this limitation.
It allows measuring nodules to fractions of a millimeter. When comparing two scans, it's just random noise. However, when looking at 6 of them over 4 years it's somewhat useful.
There is his tip as how to compare the scans that are often done on the different CT scan units. He downloaded a free software to view the scans (http://www.microdicom.com/) in order to be able to compare them more consistently. The problem is that scans from different machines come with different versions of eFilm Lite, which renders the image differently and makes comparison inexact and this software overcomes this limitation.
It allows measuring nodules to fractions of a millimeter. When comparing two scans, it's just random noise. However, when looking at 6 of them over 4 years it's somewhat useful.