 All right, so now let's look at some cases talking about the park's classification and how to approach these periano-officials using that so on this case we have starting with our fat saturated T2 series as I always do we see that there's some inflammation in this region throwing the anus and when we look at our non fat saturated T2 weighted series we can see a little bit of brightness here Which isn't fat in that interest think they're playing but clearly it's inflammation because we knew that from the fat saturated series we can also see a bit of edema in that internal sphincter musculature and Importantly we can see the external sphincter coursing anterior to that area of inflammation So we need to follow that down and we follow that down and we follow it down And we see that that external anal sphincter remains intact throughout that region And so well because this fistula never courses through that external sphincter. We believe that this is an inter sphincteric fistula tract Oftentimes you aren't going to see perfectly that the internal sphincter opening But sometimes you can and in this case I think we can suggest that the interval sphincter opening is right here at the kind of anterior position some people like to use the clock face and describing that The location of that potential internal opening to help their surgeons our surgeons at least one or two of them Don't like the clock face because it confuses them. So they prefer just verbal descriptors. So for our case, we would read it as an anterior right-sided Internal opening and then an interesting teric fistula tract tracking in that location inferiorly And exiting the skin right here near the anus itself Again, the last thing I like to use it is the post-contrast imaging and this confirms what we've already seen on those other series and in the post-contrast imaging Additionally, what we can see is the fistula tract But also we can see an area of Kind of inflammation and spread in that interest sphincteric plane and oftentimes we do see that that inflammation can spread a Good to deal within that interest sphincteric plane and a lot of people call that interest sphincteric inflammation or interest sphincteric horse chewing and When we see that explaining the extent to which that interest sphincteric Inflammation exists is helpful just to give the surgeon an idea of how inflamed and severe the fistula is because that may change Whether they do a staged approach to their surgery or how they how they go about doing things Lastly, we notice that there is an area of non enhancement within this fish list tract in this area of inflammation And I like to kind of measure how big that area of non enhancement is Because all fish list tracks may have a tiny bit of area of non enhancement, but if it gets to be over four millimeters I think that's a good cutoff to say that there's an actual abscess here And I think in this case measuring about five millimeters. There is a small interest sphincteric abscess associated with this interesting character sphincteric