CT Angio

Can anyone tell me if a CT Angio is the same thing as a CT 64, 128, 256 Heart Scan ?  And are those heart scans as good as some claim or not?  Thank you for any input.

[ed34]

An angiogram is a very good way to look inside the arteries, but is invasive of course and does give some risk. I too am confused about the details of arteries shown on ct 64 etc because I asked my cardiologist earlier this month if we could do one, she said "they are not very useful because they don't show the smaller arteries very well". I'm not about to argue with her, she is very qualified indeed.

[LindaTX]

Thanks, ed, I hope you are doing well.  Ive heard conflicting viewpoints from different doctors on the newer scanners.  Some say there's all the difference in the world between the 64-slice and the 256 but one Dr told me it's just a faster machine....plus they are hard to locate.  There is also a 320 I believe somewhere, Toshiba Aguillon 1 or something like that.  I know that West Valley Imaging in Las Vegas has a 256 model and they rave about it.  So a CT heart scan is where they inject the contrast into the arm vein and the 64-slice is the same thing?  I did have a 64-slice scan 3 yrs ago but I must admit I don't remember getting the contrast.  I do know even the 64 seemed to show quite a lot.  So the newer models would have to be an improvement I would think.  I need to get one but my Dr said to get a CT angio, not an invasive procedure like a regular angiogram.

[kenkeith]

QUOTE: "Can anyone tell me if a CT Angio is the same thing as a CT 64, 128, 256 Heart Scan ?  And are those heart scans as good as some claim or not?  Thank you for any input".

......A CT angio injects a medium into the blood stream to view the perfusion as does a cath angio or mri angio.  Just a CT scan can be for other conditions related to the lungs, descendig aotra, other organs,etc.  I have read the last generation of CT (256 slices) is so clear with 3D that is almost identical to viewing without any instruments.

"The CT 256 slice provides a quantum leap in imaging and is now being used to diagnose heart disease. This advanced scanner achieves whole imaging of the heart within a short time span using low dose radiation, providing much more visual detail about the heart's function and structures...."  Especially helpful for a fast dx in ER.

[ed34]

Here's what confuses me about such scans, perhaps someone can enlighten me :)

If you take thousands of slices of the heart, from whatever angle, I assume you can move through those slices one by one on playback. Just like you can with an MRI. Now, an artery lumen isn't going to be in one slice, it will be across many, going backwards and forwards as the artery turns and becomes more distant or closer. You probably get 1 or 2% of the artery at a time in any given slice, so how can you evaluate the lumen quality with any accuracy? You would be zooming in and out of the slices all day trying to follow the artery, let alone examine it.
I have read they can give a calcium score but as we all know this data is nonsense. It only measures calcified plaque in the arteries, not the soft plaque which hasn't hardened yet. It has been estimated that most black americans have a higher percentage of soft plaque and this is totally missed on the calcium screening.
Obviously with an angiogram you can see the arteries instantly, and the branches. This is a live image basically so I can't see the benefit of the newer scanners over this for CAD?

[kenkeith]

QUOTE: "I have read they can give a calcium score but as we all know this data is nonsense. It only measures calcified plaque in the arteries, not the soft plaque which hasn't hardened yet. It has been estimated that most black americans have a higher percentage of soft plaque and this is totally missed on the calcium screening".

Do you have reiable source that states calcium score is nonsense or is that your conclusions just nonsense based on your understanding?  Soft plaque between the layers of a coronary vessel is what enumerates the calcium score!!  Don't let the word "calcium" score confuse you. It is true soft plaque describes atherosclerosis without calcium deposits, but score is a measurement of soft plaque (non-calcified) within the layers of the coronary vessels and hard plaque resides within the lumen.

The other part of your question doesn't make much sense, or stated another way I don't understand the reasoning that it can't detect HARD plaque, etc.. Dection of soft plaque, yes, and that is one purpose of the CT scan and the utility is to develop a score based on soft plaque and then prognosticate a risk for rupture and a major heart event.  To learn of one's calcium score is not very useful information other than confirm what a good doctor would already know just based on a high lipid level.  It is not very comforting to learn there is a 20% risk of a major heart event within a year...the result of my test.

[ed34]

"Do you have reiable source that states calcium score is nonsense or is that your conclusions just nonsense based on your understanding?  Soft plaque between the layers of a coronary vessel is what enumerates the calcium score!!"

You have it the wrong way around. Calcium is what makes plaque hard. Calcium scanning detects calcium in hard plaque that has calcified. Soft plaque is simply foam cells that are dead macrophages along with fat.

examples....
http://www.ctcardiac.com/cardiacct_calcium_scoring.html
http://health.med.umich.edu/healthcontent.cfm?xyzpdqabc=0&id=6&action=detail&AEProductID=hw_knowledgebase&AEArticleID=ux1083
http://my.clevelandclinic.org/heart/services/tests/radiograph/cascan.aspx

I could list literally hundreds of examples.

[ed34]

This will be interesting for you...

http://www.medindia.net/news/CT-Calcium-Scoring-Could-Fail-African-Americans-At-Risk-Of-Heart-Problems-77455-1.htm

[kenkeith]

I was/am surprised after all this time you didn't know the substance mass of soft plaque. Sorry I don't agree with you.  Again, calcium is associated with hard plaque in the lumen of the vessel. Soft plaque has the highest risk for a heart attack and has not calcified. Maybe a better description for calcium score would be non-calcified score.  I have read that as a description, and apparently the "non" has been dropped for the procedure. Hard plaque (calcified) can be identified and rated as well.

My point and I agree, " Heart Center of the Rockies in Fort Collins, said that when hard plaque is present in the coronary arteries, soft plaque is there as well. On the flip side, if the cardiovascular CT shows no hard plaque, soft plaque could still be present; however, the risk of imminent cardiac events should generally be low"....,. So why a test for a calcium score has been my position!?

If you wish to call soft plaque "foam" I have no objections:)  I have stated many times a CT scan for a calcium score is not beneficial and gave reasons as with the above example, but I am able to distinquish between soft plaque and hard plaque and what the risks are and the significance.

If you wish you can summarize and list sources, but  I have been reading on the subject, taken the test, had my calcium score enumerated, etc. Thanks for your comments.

[LindaTX]

My calcium score is 16....is that good or bad?

[kenkeith]

I'll trade with you!  My score is  RCA (872.2), LM (79.0), LAD (215) CX (40.6)  Total 1207.1...My RCA had 98% blockage 7 years ago and was stented, the LAD is totally blocked and the CX is 70% blocked and not stented.

[ed34]

Now you have totally confused me. I originally said...

"I have read they can give a calcium score but as we all know this data is nonsense. It only measures calcified plaque in the arteries, not the soft plaque which hasn't hardened yet"

Your responded with ...
"but score is a measurement of soft plaque (non-calcified) within the layers of the coronary vessels and hard plaque resides within the lumen."
You imply both hard and soft here. Then you come back with...
"I was/am surprised after all this time you didn't know the substance mass of soft plaque. Sorry I don't agree with you.  Again, calcium is associated with hard plaque in the lumen of the vessel"
You say you don't agree with me, but you are agreeing, it's the score of just the hard plaque in the lumen.
???????????

[kenkeith]

Q: You say you don't agree with me, but you are agreeing, it's the score of just the hard plaque in the lumen.

....I don't see the wording to be confusing! It is NOT if ever just the hard plaque in the lumen that is scored for any prognosis....it is the soft plaque that is scored (at least in my ct scan) and the issue of interest regarding a high or low probability of RISK is its represenatation....hard plaque represents a low risk of heart attack and to include that metric would be combining lumen hard plaque to the higher risk soft plaque and that would certainly contaminate the prognoses of soft plaque (doesn't even make sense);  that distinction has been made a number of times and should not confuse you if you integrate information. However, it is my understanding hard plaque can be included in a ct scan, but then a distinction should be made and another subject.

I found a good representation of the issue in my computer research file on the subject and I am providing a link to a single picturial.  It illustrates a linear continum of a vessel that begins with a lesion and its progress is followed with a time span of 4 decades.  Anywhere on that continum a score can be enumerated and the the rupture score is about 500 (my memory) or above and a prediction of a heart event within a year is about 20%.  

http://en.wikipedia.org/wiki/File:Endo_dysfunction_Athero.PNG.

[ed34]

But the diagram you give only mentions calcification from the fourth decade, in the fibroatheroma stage. This site states calcification doesn't creep in until the type V stage...

http://wiki.medpedia.com/Atherosclerosis

[kenkeith]

The point I was trying to get across has been made. To answer your parameter question is due to the fact there are no uniiform variances of soft plaque or anything else on an individual basis.  That is why there are ranges. Consider labs have different parameters for testing:  some labs state 50 to 70%, other labs 55 to 75% for ejection fraction, different critical heart wall sizes, etc., etc.  Its the etiology of soft plaque maifestion via CT scan and possible rupture prognosis.

[ed34]

So there would have to be billions of ranges, one for each individual on the planet lol. This scanning procedure cannot differentiate between quantities of high soft/hard plaque, it can only detect hard plaque which is my whole point. It someone has a very high level of soft plaque, the starting of atherosclerosis, the score will look great. This patient loaded with soft plaque will be signed off as healthy and unlikely to have any heart events. This has happened lots of times and continues to happen, especially with people other than whites. So, I fail to see how any ranges can possibly help at all with this situation. There is no way to tell from this method just how much soft plaque is under the hard plaque either. There could be a huge amount under pressure, or hardly any at all. It's meaningless and pointless and a complete waste of time and money in my opinion.