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So I will just get started here and I'd like to welcome everybody

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who is signed up to join us today.

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I hope you guys are all healthy and safe and

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I'm very honored to be spending this afternoon with you.

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So I've got five or six cases to share with you today on

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rectal MRI and before we start I'd just like to let everyone know that

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the platform I'm using today is called Radpix and it's been made available

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to me courtesy of the Society of Abdominal Radiology so you may have

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been familiar with it if you've ever attended any of their courses.

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So without further ado let's get started. So this is the first case

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here and I'm going to scroll through the images.

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So this is a 78 year old patient with rectal cancer presenting for

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primary staging. So I'm not going to ask about how to stage this

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case in particular for this one but this is more of a technical

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question. So as you can see there's a mid rectal mass here it

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looks kind of polypoid or semi circumferential arising from the posterior

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wall and I will just show you a couple of other

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sequences here. So here we've got an axial oblique, and we've got another

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axial oblique which I'd like to share with you.

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So now we have the two axial obliques sets of images that we're scrolling

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through side by side and you might be wondering why do we have

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two sets of images and here you can see the tumor which has

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raised rolled edges and an ulcerated center and this is a very common

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appearance of rectal cancer. So if you're not too familiar with reporting

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these cases this is a good tip to just think about when you're

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reporting these rectal MRs just like in the old days with barium enema we

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look for lesions that have raised rolled edges with a core of central

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ulceration which is this little divot here that you see. So that can

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often be helpful to identify a rectal cancer sometimes if the walls are

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thickened in some areas it can be difficult to find the cancer in

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the first place but if you're looking for an ulcer

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that certainly can help you localize a lesion. So maybe we'll just move

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to the first question. So I showed you that we have two sets

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of axial oblique images here and I want you to

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try and spot what the difference is because we did something between these

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two sets of images. So what action do you think has been taken

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between the first and second sets of images that I'm showing you here?

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So we've got four choices there and I will

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keep scrolling through so you guys can have a chance to spot the

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differences. So they're very similar looking except for one modification

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that's been made. All right so the majority of you,

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two thirds, thought that we had given anti parasitic medication and then

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there were a couple people who thought we had modified the axial oblique

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plane. So those are both good thoughts. The correct answer is actually administration

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of anti parasitic medication. So the reason I like to show this case

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is because it really highlights the reason why anti parasitic medication

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is really so helpful in rectal MR imaging.

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There's been a number of consensus statements about protocol for rectal

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MR imaging. One of the go to bodies that I consider is EDSGAR and they've

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come out with statements regarding protocol and anti parasitic medication

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is not a requirement for rectal MR imaging according to these bodies but

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from my personal experience it really helps. So in this case you can

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see that the margin of the tumor at the muscularis propria looks kind

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of blurred on this image but then if you look at the image

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with the buscopan or glucagon whichever you're using you can see that the

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muscularis propria is actually quite well maintained. So

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in this case I think it just gives me a bit more confidence

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to stage the tumor. So I would highly suggest using buscopan if you

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can and I think that it just gives the reader much more confidence.

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So well done there. So I'm going to go back to the sagittal

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image here and this is just anatomy question

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and I think probably Ryan we might not do the poll for this question

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I just wanted to point out a little bit of relevant anatomy here

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so we can probably do that without polling just to save some time.

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So the structure that I was going to ask about is this structure

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annotated by the yellow arrow so it's this here this hypo intense line

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on T2 which extends down to the seminal vesicles

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in this male patient. So this is the anterior peritoneal reflection and

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I just wanted to show this because it's a really nice

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example of that V shaped reflection that comes down and hooks down at

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the base of the prostate or the seminal vesicles and reflects back up.

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So those of you who already do rectal MRI staging will know that

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the peritoneal reflection is an important landmark for surgical planning

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and this lesion here straddles or is mainly above the anterior peritoneal

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reflection. So I just wanted to point that out

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and in males if it's hard to see you can look at the

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base of the prostate or the top of the seminal vesicles just to

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help you localize where you think that reflection is going to be and

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in women it usually tends to be at the lower two thirds of

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the posterior uterus right at the junction of the uterine body and cervix.

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So that's that teaching point here and now I'm just going to move

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on to another case that we'll go through.