Wednesday, 2015/11/25 – Slicing and Dicing and Pretty Colors
One great thing about Kaiser is that they keep all patient data (as far as possible, which is a lot) in their computer system, and it is accessible from all their locations. It’s not perfect, but it is decades ahead of most other healthcare providers. I requested all my diagnostic imagery from all locations, from 7/01 to 11/18, and I got it on 11/23, on two CD’s. It cost me $15.00, but for a technerd like me, it‘s totally cool! It comes with a viewer on the CD, and has GOBS of images, some of them really amazing to look at. I can’t give you the interactive experience of being able to rotate the image in one view, or to select different slices to view, seeing the structures change, but I have exported a few images as examples. Here is a slide show of them:
CT scan for reference
Here is the single-slice CT scan that was done before the PET scan, to show where things like bones and organs and blood vessels were in relation to the tumors.
CT scan with colors for contrast
Enhancing the colors helps identify the structures, but still does not point out the tumors.
PET scan fused with CT scan
A fused image combines the PET scan with the CT scan to show the structures of the area of interest, and also highlights the glucose-hungry tumors.
closeup fused head
The cancer shows up bright yellow because it has gobbled up as much radioactive glucose as it could, and so does my brain, because it also uses only glucose for energy, and a lot of it, too.
MIP VR image
This image set can be rotated with the mouse (in the special viewer, not a web browser) and gives a very clear idea of just where the tumors are.
Sagittal CT slice with text overlays
Each image series has a lot of text information embedded in the DICOM file.
color contrast of CT
The sagittal plane is fascinating, but again, CT does not clearly show the tumor, even when color-enhanced.
fused images, overlaid
Even the fused sagittal PET/CT scan was a bit hard to read, because the tumor was off to one side of my neck. The slices that included the tumor were not down the center, so my nose wasn't in them. I combined two exported slices for this image.
axial plane fused image
The axial slices are the ones most directly related to the actual scanning pattern, and give a clear picture of how the tumors were situated beneath my jaw, very close to my jugular vein, carotid artery, and parotid gland. The linac also rotates in this plane.
Fused Axial closeup
The cluster of cancerous lymph nodes is plainly visible here, and I am hoping that in December it will be conspicuously absent.
Fused image with color contrast
A slice at the same depth (202.39mm down from the top of my head) with normal color enhancement, shows the tumors clearly, but not the nearby structures the planner will need to avoid destroying.
Fused Axial with Bronson colors
The "Bronson" color scheme makes the tumors stand out in stark contrast.
The usual X-ray film image from a CT scan, monochrome, of a slice smack down my middle (coronal plane)
The CT scan image enhanced by using color to increase contrast between densities.
PET scan FUSED with CT scan: less resolution, but the cancer stands out because of its preference for glucose. Our brains also use glucose exclusively, so mine shows up as bright as the cancer in my neck.
The reason the PET scan shows the tumor so clearly (though the actual resolution is less than the CT) is that PET actually shows FUNCTION rather than just physical structure. I was given an infusion of glucose with radioactive Fluorine attached to it. This shows up in the tissues that are the most greedy to use it, like the brain, active muscles, and the cancer. If you missed my other description and details about the PET scan, HERE IS A LINK.
It’s fascinating to manipulate the color scheme, and to scroll up and down through the slices the computer can display.
The imagery is stored in DICOM format, which is specifically adapted to medical use, and a special reader is required to view it, but free readers are available online. SLICER is a feature-rich open-source, multi-platform reader, and MicroDicom is a simple reader for Windows