 Welcome. I'd like to take this opportunity to invite you to our 24th annual pre-RS and a MRI course held at the Four Seasons on Delaware in Chicago and Warman's sunny Chicago November 25th through 28th over Thanksgiving. This is primarily a case reading course, and I'd like to share with you a case right now so that you can get a feel for the format of this case, which is now coming up on almost a quarter of a century. Let's get started, shall we? This is a middle-aged male who presents with a mass in the first web space or between the first and second digit in that web space that is getting slightly larger and is a little bit fluctuate in the short axis projection using a fat suppression sequence, which you can tell from the appearance of the fat, which is very black. There is a mass exactly where it was suspected. The mass is mostly hyper-intense, but in the center of it is an area of hypo-intensity, so it's somewhat heterogeneous. The lesion is not just indurated. It's not just amorphous. It is actually mass-like in character. How about the shape of it? I think most of us would agree it's a little bit oval or pear-shaped with two little nipples on each end. How about the location of it, compartment-wise? Well, it's not in the epidermis. It's not in the skin. It's probably not even in the dermis. It's probably more in the subcutous space but not in the muscular space. How about the zone of transition? It's got a very sharp zone of transition with little evidence of surrounding edema, so far all features that we've identified that suggest non-aggressive behavior, particularly the part where the mass does not cross compartmental boundaries. For instance, it doesn't go from the subcutous into the muscle. Let's take a look at the T1 weighted image. Although the patient has moved a little bit, there's a little bit of pulsation, the mass which was not given contrast on this image is a little hyper-intense, suggesting either a high protein content or dilute hemorrhage. The differential diagnosis of such a mass might conjure up a ganglion, although this would be a very unusual place for a ganglion, and a ganglion is a pseudosist, so the T1 signal should be lower. You shouldn't also see these globular areas of lower signal intensity. Common skin lesions, like the benign fibrous histiocytoma, not elliptical, not as well-defined, and also the signal characteristics of this common fibrous tumor, not really fitting this particular case. One lesion that would fit would be a hemangioma. These can contain little bits of clot. They can be round. They're usually a bit more lobulated, a bit more irregular. They frequently look like a bowl of little raisins or small grapes, but there are cavernomers that can have this appearance. Although, they shouldn't really be such a beautiful oval, but most importantly, when we look in the long axis projection, we see that our mass has a tail. Which masses have tails? Well, masses that are attached to or come from other objects. A ganglion pseudosis has a tail. The tail goes to tendons or to a capsule. What about a schwannoma? It has a tail to a nerve. What about an aneurysm or a pseudo-aneurysm? It may have a tail or a communication with an artery or an arterial. And our mass has a communication both distally and proximally with a large superficial vein, making the diagnosis pretty straightforward that of a giant varix, thus explaining the higher T1 signal, the area of low signal inside, a contractile clot, and its overall shape and fluctuent behavior on palpation. Well, that's our case. That is what our course is going to look like in November of this year. I hope to see you at the Four Seasons on Delaware in downtown Chicago, November 25th, for our International Ortho-MR Review. Thanks and have a great day.