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High Resolution CT Scan (HRCT) with Contrast

I'm going to be having a lung HRCT with Contrast dye on Tuesday. I haven't been told anything about it other than to fast for two hours before and that I needed to have my creatin checked. (it was ok).

So...I was wondering if those who have done it can tell me what to expect and anything they would do differently to prepare and/or during the test, if they had to do it over.

Thanks, beth

9 Replies

Hi Beth,

The only thing I was glad I was warned abour is that it can make you feel like you've wet yourself as you get a weird sensation in your groin and they're right, it does feel like you've done thid but haven't. Weird!!



I had this test a couple of years ago and it was absolutely fine. Like Angelica said, you do get the feeling you are wetting yourself or going to but that is pretty brief. I had to sit around for I think 20 mins after too incase I had a reaction to it and then they can take the cannula out. I found the whole thing quite interesting.


Hmm, I'm puzzled. Not sure I can add to this because I've had a HRCT chest but no contrast - when I looked it up beforehand all the stuff I read suggested that contrast is not normally used for this specific scan! So not really sure when/why they would or wouldn't use contrast.

That means I can't help on the contrast bit but the rest was fine. Apparently sometimes they ask you to flip over so you have some images done while you're on your back and some on front. I was told they would be doing this at the start but then it was just lots of 'breathe in...hold...breathe out' for a bit and then they said I could go. Asked about whether they'd do ones with me on my front since they'd said that to start with, but apparently the consultant had requested a very specific set of images which were all to be taken on my back.

Overall, it was pretty easy and painless though like I said, I didn't have any contrast. It's not claustrophobic at all as the scanner is pretty open and I don't think I needed to do anything special to prepare. Perhaps take your inhaler beforehand? I think they were ok with that and it might make all the breathing in/out a bit easier esp since you're lying on your back.

Hope this helps and good luck!



I had the contrast done to check for a clot if I remember correctly.


Ah right makes more sense then. I had a VQ scan for that - very tedious.


I had the VQ scan too :-)


I'm not quite sure, but I think the contrast is meant to tell apart different reasons for peribronchial thickening seen on a chest x-ray, which can be due to lung tissue or due to blood vessels.


Contrast is usually used with HRCT's if they want to specifically check for Pulmonary Embolisms. I asked my consultant about this, as Im due to have an HRCT in March and am allergic to iodine contrasts (had contrast when I was admitted with renal stones). She reassured me they wouldn't use contrast as they weren't looking for PE's.

Hope that helps,

Lynda :)


Beth, hope the scan was ok and you get the results soon. I haven't heard of fasting for a lung CT scan unless they were planning to look at your abdomen too so can't answer that one - I assume different areas have different scanning protocols.

As Angelica and JF said, the contrast can give you some strange feelings of heat, needing to go the toilet etc. The bloods are part of several safety questions they would have checked alongside allergies, any previous reactions etc I would expect. Contrast is generally used in looking at blood vessels and clots etc and telling the difference between these and adjacent tissues.


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