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So beginning with normal anatomy of the

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appendix, the easiest way to find it

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is that it arises posterior and medial

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from the cecum, approximately one to two

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centimeters below the terminal ileum.

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If you have three-millimeter slices on

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your CAT scan, that averages out to about

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three or six scrolls, and it should come

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out the same size as the terminal ileum.

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So in this CAT scan right here, the

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TI is coming out right around here.

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Oftentimes you can identify

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that by the fatty valve,

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which occurs right here.

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It's similar to the mesenteric fat nearby.

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So if you scroll down a few clicks from there,

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the appendix should normally come off the same

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level, the same side, usually posterior medial

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as in this case, and it'll be a smaller, thin,

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blind-ending tube, as you see right here.

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Sometimes you can't find it on the axial,

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and the coronal can be helpful as well.

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Again, here's your TI, here's your fatty

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valve, right here, entering the cecum.

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Scroll back and forth until you find a

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blind-ending tube, usually has a few gas

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in it, and that's the normal appendix.

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The appendix itself is usually less

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than six millimeters in diameter, but

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what's important too is the morphology.

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It should have a few foci of gas

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in it and a relatively thin wall.

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They can be up to eight centimeters in length

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on average, but that can be pretty variable and

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there are reports of it up to 30 centimeters.

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In different cases, the appendix can move.

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It can be mobile in between scans.

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In any particular patient and in

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different places in different patients.

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It can be located in the pelvis in the

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right lower quadrant, as in this case.

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It can be retrocecal, retrocolic, and

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it can be intra or extraperitoneal.

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One of the rare locations of the appendix is

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shown in this patient who's post-surgical.

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As you follow the cecum down,

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you can see that there's

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a right inguinal hernia.

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In this case, it contains the cecum,

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and you can see some smaller loops of bowel.

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So there's a terminal ileum in here as well.

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And if both of those structures are located

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in the right inguinal canal, then the appendix

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must be as well, and here you can see a small

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tube with a little foci of air, much smaller

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than you'd expect the terminal ileum to be.

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You can actually see it enter and conjoin

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here with the cecum on that slice right there.

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So this is a special place for the appendix.

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It's called an Amyand appendix,

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which is where the appendix itself

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is within an angle of hernia.

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Of course, they can get inflamed,

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you can get an acute appendicitis

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in an inguinal hernia, but in this case,

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it's just kind of hanging out there in a

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normal variant of a location right here.

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So colon, cecum, appendix down

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here, terminal ileum up here.