CT result question

[DavesMom]

Hi all,

Got my CT scan results back and apparently my ascending aorta has gone from 4.5 cm last year to 4.3 this year. Yay!!! I'm not complaining about the decrease, believe me, but this puzzles me. Are aneurysms known to decrease in size? Or could it just be chalked up to a difference in the tech who did the scan and the radiologist who read it?

Any info would be appreciated.

Cheers,
Michelle

 

[Duff Man]

I seriously doubt it shrank. The measurement was probably taken from a different machine, from a different angle or plane, and/or a different location of the aorta by a different person. Even if it's the same person and machine, he or she could place the little measuring indicator slightly different this time than they did last time. There's also motion to consider. Your heart and the stuff around it is constantly moving just a little bit.

If you request a copy of the scans on cd you'll be able to see what I'm talking about.

 

[Andrew'sMom]

Michelle,
Interesting post. I am curious to see the replies. This year when Andrew had his exam we had a new tech after having the same one for the last 5 years. This one was super fast, zoomed through the echo at lightening speed ... and we got the verdict that things are relatively stable.... it makes me a little nervous! The old tech always took her time, and seemed to work very carefully. I am waiting for Andrew's echo report to compare numbers from last year, and have been wondering what I will do if, like in your case, I find numbers going in the wrong direction!

 

[DavesMom]

Thanks for the replies. Duffman - I kind of figured the difference was due to the things you mentioned. This is only my second CT scan so I wasn't sure if it could vary. Still, the good news is that the doctor says it's stable. I'm going to get a copy of the report next week and may ask for a CD.

Andrew's Mom - I know EXACTLY what you mean. I've had techs in the past take time and care with my echo and then I had one this year who was done in about two minutes - and there were a lot less measurements listed on the report than last year's. It does make you wonder if something could be overlooked.

As I said, the good news is that it's stable but of course I'm left to wonder which of the CT numbers is right.

Cheers,
Michelle

 

[Braveheart]

Routine CT maximal diameter measurement of AAAs can have substantial interobserver variability. Standardized measurement protocols can decrease, but not eliminate, this measurement variability. Thus apparent size changes based on CT measurements may represent measurement artifact rather than actual aneurysm growth or shrinkage, particularly when a standardized system is not used.

http://www.journals.elsevierhealth.com/periodicals/ymva/article/PIIS0741521403017919/abstract

Apparently, there are many variables in the reading and interpretation of a CT scan.

 

[DavesMom]

Thanks for the link, Braveheart. Interesting reading, but it's still a bit frustrating. I can understand a bit of a variation but 2 cm seems a lot to me.

Take care.

Cheers,
Michelle