Radiology Forums

BZMAN · Joined: 02 Oct 2007 Posts: 7 Location: ILLINOIS

Im sure everyone has done a PE chest and done everything right , but then they get suboptimal pulmonary vessel filling.
We use an 18G , with 100 ml of Visipaque 320 chased by 30 cc of saline. We set the roi on the pulmonary bifurcation with a 4 sec delay using a Seimens 16. The scanner started when it was at 130 HU. During the scan it got up to only 150HU. This seems to happen occasionally on bigger guys. The contrast was still injecting when the scan got down past the pulmonarys. Does anyone inject faster than 4 ml/sec? I also had him not take a deep breathe because 1 place i worked at said that the large intake of oxygen would delute the contrast. Is it just some people are not gonna give you a great study? Sometimes on our regular chest scans @ 2.5 ml/sec with a 10 delay off an roi on the descending gives a great pulmonary filling. Any input appreciated.............BILL

papa · Posted: Wed Oct 17, 2007 1:48 pm Post subject:

you're using the seimens bolous prep, i assume?

i used to work on the 4 slice seimens. the deep breath thing is true, i've had radiologists tell me the same thing. i work on the GE 64 now, and i don't really use the smart preps (bolus prep) that much unless the patient has a nice long medical history (a-fib, cardiac issues, diabetes, etc.) i've been doing 100cc Optiray 350, 3.5 to 5.0 cc/sec, with a 30 sec delay, and they've come out fairly good.

with the newer faster scanners, try to time the contrast so that the contrast is flowing fast enough (at least 3.5 to 4.0 cc/sec), and that you start scanning exactly when (or even a couple seconds after) the contrast stops and starts the saline. this should put the contrast in the pulmonaries and periferal arteries of the chest without phasing into the venous phase.

hope this helps

papa
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ScrmnWoody · Joined: 22 Aug 2007 Posts: 40 Location: Bellingham, WA

We inject at 4mL/sec, as well. For PE studies (or any other CTA) we use no less than a 20g Angiocath. We trigger off the pulmonary trunk at 180HU. But, we're using Optiray 320 or 350 with a saline chaser. We use Toshiba's "Sure Start" bolus tracking program and it seems to work very well.

A couple things we've noticed:

If the Sure Start scout slice doesn't ask the patient to take a breath in and hold it, then neither should the Sure Start fluoro. Otherwise, the ROI can sometimes trigger off the wrong anatomy and you end up with an early or late scan. We also shrink our ROI diameter down as small as possible.

On occasion, we will use Visipaque. But, we've never gotten quite the same images with it. But, we'll use it on patients that we're a litten concerned about the renal history or function.

My guess is that a big guy with Visipaque on board isn't going to give you the same "bright" contrast filling that you are used to. We can't even seem to get it on average sized patients using Visipaque. I know some people swear by Visipaque. But, this has been our experience with it.
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BZMAN · Joined: 02 Oct 2007 Posts: 7 Location: ILLINOIS

Yes, we use siemens smart bolus prep. Ive tried to tell people lately when they hold their breath, not to bear down (valsalva), because Ive read that it can cause interruption of the injection. The Drs here want to use Visipaque for all angiography studies. Other places ive worked only use it on higher risk patients. Noy sure if that is a factor or not. Thanks for all responses..............Bill