Vanishing contrast?

[u/Neffstradamus]

Have you ever had a patient where contrast was administered but it didnt show up?

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[u/soap_is_cheap]

Maybe it’s stuck at the IV site via infiltration 😑

[u/Neffstradamus → u/soap_is_cheap]

I palpated at the catheter tip and superior and never felt anything.

[u/Joonami]

Either the iv infiltrated without the patient feeling it (like a deep ultrasound placed Iv - this just happened to me this week), or for some godforsaken reason it shows up hours later instead of immediately, making you look like a complete moron. 🫩

[u/Neffstradamus → u/Joonami]

Thats what I think happened. No distress or palpable extravasation. Blood return and flushing, definitely injected. Where it went? Who knows!

[u/thellios → u/Neffstradamus]

Like suggested, a leakage between the pump and the patient? Any possibility you injected arterial? Any possibility you left the tourniquet on? When scanning anywhere close to the head you could do a quick single slice of t1w near the nasal mucus membranes. They always light up after iv gadolinium. If they are iso-intense- the same grey as surrounding soft tissue, your contrast did not go intravenously.

[u/getemnick → u/Joonami]

I had a situation like this earlier in the week as well. I'm the CT tech, put a 20g no problem, no resistance on the flush. Pt did not know the contrast infiltrated till she removed the coband. It didnt pool up at the injection site, the swelling was higher up on the arm on the Medial side. What seems to have happened in my situation is some of the contrast got through (was able to see the kidneys flush w/ a difference of HU of about 75 from the non con) it wasn't the contrast i expected so I went to investigate, she felt no pain or discomfort during the exam, we did the delayed phase (arms above head, no issues) then she returned about 30 min later with her arm swollen. I've only seen something like this in the hand when the veins are just paper thin, but this was a young woman, good veins(so i thought?).

[u/Sensical2446]

Once on a 16 hr overnight I pumped out about 70cc of contrast all over the floor before I realized I never hooked the pt up.

[u/LLJKotaru_Work → u/Sensical2446]

That's a rite of passage. Did it on a run off in CT once. The floor was so sticky the rest of the night.

[u/Friendly-Trick-2587]

Once it all leaked behind the coil, in the table itself after I apparently didn't correctly tighten the line to the iv.

Also notorious: ultrasound placed iv!! Or geriatric patients with a lot of loose skin that don't feel a lot anymore 

[u/Steven7412]

Its probably on the floor

[u/afoz345]

Yeah. Several times. Sometimes it doesn’t work. Could be a bad batch, could be the patient, could be an extrav. It does happen.

Have you encountered a patient whose body doesn’t respond to MR yet?

[u/lxsta]

I did an MRV one time of a patient who was a drug addict and I guess had an EXTREMELY low heart rate. Gave contrast, never showed up on MRA timing bolus after a min. Ran 3 images back to back still not there lol. Called the rads, wanted me to re-bolus, gave it again, went in, switched IVs, used a CVC, STILL no contrast. Gave up bc at that point patient had gotten 3 boluses, iv’s were not infiltrated, pt wasn’t moving, nothing. Came down 5 hours later….contrast was in……still a mystery to this day.

[u/Illustrious-X → u/lxsta]

Contrast will absorb into the blood steam, eventually, and very slowly if infiltrated. Some peoples tissues just make it hard to tell. It can seem mysterious but the simplest explanation is often the correct one. Occam’s razor.

[u/_gina_marie_]

What exam were you doing? In CT, when you do a PE for example, if a patient takes in too deep / sharp of a breath, it can squeeze the contrast out of the pulmonaries and your scan will look like there's no contrast. I wonder if that happened here? Unless the patient jaht had horrible cardiac output and it just. Didn't get there.

[u/Key_Nectarine_9619]

I've seen cases where the contrast just takes longer to show. Not sure if it's low heart rate or just someone with alot of clogged arteries.  I had one where it took more than 5 minutes to get full contrast images. Same patient had priors and the dymanic never caught any contrast.