Which imaging modality is best for "screening" in immune mediated disease?

RE: Which imaging modality is best for "screening" in immune mediated disease?

Sara Ramsey — Tue, 25 Feb 2020 20:00:29 GMT

Thank you for the replies, the question of size is interesting and makes sense and I'm re-assured that there isn't always a "right" answer.

It's interesting that time and logistics are factors - even in referral practices. Our CT scanner is in a different building from the other imaging equipment and this does sometimes have to be factored in and patients have two sedations for example.

The case I'm thinking about is a 6 month old poodle with polyarthritis. I stupidly didn't xray his chest when he was anaesthised for joint x-rays and taps...lesson learnt.

I suppose that in a dog of his age I would hopefully be looking for an inflammatory rather than neoplastic cause. I am awaiting tick panel, his urine culture was negative

Roger: have you seen GI lymphoma as a cause of immune mediated disease in patients with no signs of GI disease ?

RE: Which imaging modality is best for "screening" in immune mediated disease?

Andrew Kent — Tue, 25 Feb 2020 12:20:34 GMT

Hi Sara,

This often comes down to size (as well as cost, time and logistics).

For larger dogs (from memory over 25kg) the sensitivity of ultrasound for abdominal disease starts to reduce so would favour CT.

For small dogs they are likely equivalent so decided by other factors.

For cats abdomens ultrasound is superior to CT so would favour that approach (although we see less cats for this purpose).

In case it makes a difference - we CT under sedation which may reduce your costs a bit?

Andy

RE: Which imaging modality is best for "screening" in immune mediated disease?

Andreia Dias — Mon, 24 Feb 2020 21:58:35 GMT

We do number 2 (only work with cats).

RE: Which imaging modality is best for "screening" in immune mediated disease?

Roger Wilkinson — Mon, 24 Feb 2020 20:45:02 GMT

Sonographer opinion.... I haven't quite got the energy to trawl the literature but my impression purely from personal experience is that neoplastic triggers for I-M disease not frequent in practice and the commonest is GI lymphoma...which you'd probably choose US to screen for.

Plus if it's potential IMP then it's useful to ultrasound scan the joints to choose which ones to tap and also need to screen chest and abdo for septic/inflammatory conditions which are also potential triggers. I read a human rheumatology article the other day in which they described using ultrasound as a routine tool for a quick look at a bunch of joints in each patient.

Plus it's so much less hassle