Thursday, December 02, 2010

RSNA 2010: Two SPECT/CT's

The one piece of equipment I would really like to have is a SPECT/CT scanner.  For some reason, our hospital doesn't want to part with the $1 Million or so that one would cost, but I'm hoping that the claim of having an extra CT in the house will help my case.  We'll see.  Maybe I'll just buy the darn thing myself and park it in a trailer...

My criteria for the scanner remain fairly simple:  I need an excellent SPECT camera integrated to an excellent, DIAGNOSTIC quality CT.  That's it.  Until recently, only the Siemens Symbia T series fit the bill, but as I have reported earlier, GE finally listened to me and put a proper CT, the BrightSpeed 16, in the package, creating the Discovery NM/CT 670.  The 670 comes in only one main flavor, with the 16 slice CT, while the Symbia can be had with 2, 6, or 16 slice versions.  Beyond that, the hardware differences between the two are relatively minor.  The GE has semiautomatic collimator change, while the Siemens will do this all by itself.  There are various automatic protocols for scanning and QC, and even center of rotation correction.  Both have 70cm apertures and both can handle 500 pound bar-be-cue addicts as we tend to have back home.  The Symbia has been around for a few years, and it is mated to the older Emotion CT platform.  Although this is still being sold, the upgrade paths for Emotion are not as robust as those for the newer BrightSpeed, and some of the newer software toys are not going to be available.  CARE, one of the dose-reduction initiatives will go Emotional, if you will, but SAFIRE, the iterative-reconstruction software, won't.  I didn't get dose figures, but I'll have to assume we won't clear that 2.4 mSv threshold.  I could be wrong. 

GE touts the new version 3 of the Xceleris computer for acquisition, processing, and viewing, although the viewer is rather busy and doesn't do some stuff that the AW workstation does do such as edge/threshold detection of a lesion.  There is, however, rigid registration of an old to a new study, and red contour lines are superimposed to confirm the match.  It is possible to superimpose two molecular imaging studies (PET or SPECT) over one CT with a triple color map.  There is some new cardiac software, which allows CT acquisition for just the rest or a stress nuclear perfusion which will then apply it to the stress or rest images respectively.  "Cardiac Morphing" gives a more accurate "splash" display, which can show the various slices of a perfusion study corrected for time.  In other words, I can see all the slices as they would appear in end diastole or end systole, which gives a bit different view than the conventional summated slices. 

Siemens is still showing the eSoft software I've been using with my Biograph PET/CT.  There is now a remote client,, which (finally!) allows viewing on any computer.  I did not see anything about how syngo.via might be used for processing or viewing the Symbia images.

Images.  Here's where I'm going to get myself in trouble.  I've just gone through an ACR accreditation at one of our places, and one of the older cameras didn't do well with bone SPECT.  Thus, I wanted to see how each of these new toys would do in that space.  I have to say both produced rather similar images.  And they were not great.  Now, when you superimpose the blobs over the CT acquired contemporaneously, they don't look so bad.  But viewing a bone SPECT on each workstation from the sample data that is always present at a trade show was, well, disappointing.  The vertebral bodies were muddled, and not clearly demarcated.  Disc spaces were faintly seen, if at all.  One team tried to refilter the data, but to no avail. 

Since I don't have funding at the moment, I have the luxury of sitting back and watching for improvement.  To be scrupulously fair, I'll probably have to see both of these battleships out in the field, with live data rather than the canned-RSNA images.  Now that I've dissed both machines, I'll bet the next bone SPECT on display will be incredible.  I'm hoping to see clearly, without having to use much imagination, some sharper images.  But then we are talking about Unclear Medicine, aren't we? 

More to come from sunny, but extremely cold and windy Chicago.

No comments :