 Okay, this is a 62, 63-something year old man, elevated PSA, incidentally found, over 40 at a health fair, and he's got an abnormal physical examination and an abnormal MRI. On the far left is his ADC map. The ADC map not only demonstrates areas of low intensity, but these low intensity areas have to correlate with something, and they do, areas of confluent, mass-like, teach you hypointensity. They also have to correlate for it to be a pi-rats 4 or 5 with a hyperintensity on diffusion-weighted imaging, for if you see low-single intensity areas like this, but the DWI, the diffusion-weighted image, is negative, then it's no longer a pi-rats 4 or 5 diffusion-weighted designation. Let's go over to the DWI with a B value of 1600, and remember, we like our B values to be 1400 or greater to do the job of showing hyperintensity in the prostate. Simply going over a thousand is not sufficient. We've said that diffusion restriction occurs because of viscosity, dysmoplasia, cell packing, and even cell membrane death with influx of fluid into the cell itself, restriction of water motion. All those things can happen and produce diffusion restriction. That's why you get it in abscesses. That's why you get it in epidermoids. That's why you get it in brain infarctions. In the right side of the gland, there is very good correlation between hyperintensity and also much broader area of hyperintensity in the right gland compared with the left gland. It's a low-resolution image, I do understand that, but it's got very good correlation with the ADC map. It also, you'll have to trust me or go back to some other vignettes, has very good correlation with the T2 spin echo image, but I wouldn't do that to you. I'm not going to ask you to go just completely on blind trust. I'm going to show you the DCE MRI. Let's start all the way at the apex of the prostate. We're near the base of the penis. Let's work our way from apex to base. Here we are, toodle in along. We've got diffusion on the right, on the viewer's right. We've got ADC map on the viewer's left. Watch the bouncing ball as we work our way up. Keep your eye on the prostate gland, which is going to show up in here. Let's keep going, shall we? We're working our way up. Actually, I think I was back a little far. There's the rectum. There's the urethra. Let's keep going, shall we? Now, we're live, and now we're getting into the urethra. You know what? Right away, we start to see a little bit of asymmetry. You're saying to yourself, really? Is that enough to be bothersome? Not by itself, but when you affix it to the rest of the findings, yeah, I think so. Keep going. Let's go to the next slice. The next slice, just to get you in the groove, is the mask before the contrast has gotten there. How fast do we want the contrast to be evaluated? Ideally, about every six or seven seconds per frame. That should be your temporal resolution in the ideal setting. What am I willing to accept? 20. 20 seconds per frame. In the breast, what am I willing to accept? Two to three minutes. A lot longer. What's ideal in the breast? 50 to 60 seconds. The breast DC MRI is not the same as the prostate DC MRI for temporal resolution. You've got to have faster temporal resolution in the prostate, which means more coil elements, more parallel imaging. Here's our mask. Now we're at six or seven seconds, and yeah, it's positive. That's a little thicker and a little brighter than the other side. You may not believe it, but keep watching. Now we're going to watch it get a little more fuzzy and a little bit thicker. Yeah? Now we're on to our next slice. Back to our next mask. Let's go to our next mask. Little thicker on the right than left. Let's skip over to the next slice. Little thicker on the right, and the next slice. Little thicker on the right, and we haven't really stumbled into anything that we could hang our hat on yet in the diffusion and ADC map. Let's skip to the mid portion of the gland. Let's go up a bit just for time. Let's go to this location here, mask, six or seven seconds. Oh, yeah, our ADC map's positive now, because we've got the volume to see it, and our diffusion weighted image, it's positive now. Our lentiform lesion goes all the way from the anterior gland to the posterior gland. It abuts the capsule for greater than 1.5 centimeters, and it does so on all the sequences. It's a pirad's five all the way around the horn. Let's go up near the base, higher up near the base of the prostate, closer to the base of the bladder. So there's a mask, there's our positive ADC map, there's our positive DWI image with the B value of 1600, and let's see what happens immediately, and without warning, our right gland is certainly a lot different and a lot brighter than our left gland. Our right gland has these little fingers that are infiltrating through the capsule. Our right gland has an area of abutment of the capsule that is greater than 1.5 centimeters. It's a pirad's five. Let's go up a lot higher now, really high, almost to the base. Let's go to the mask and to the seven second image. Look at that. That's where the most aggressive portion of the tumor is. That's where the ADC map is the darkest. That's where the diffusion-weighted image is the brightest. That's where the intensity is the brightest. That's where the infiltration through the capsule is the brightest and the most different from the rest of the gland. This is a DCE MRI positivity. It's a diffusion-weighted and ADC map pirad's five. Just to top it off, let me put up a B zero, some intermediate B value, let's say 800 to 1,000, and then on the far right is 1,600. Let's look at the difference between the three. We're at the same location. Let's just take something with a low B value and a high B value. Let's ignore the one in the middle. Let's just do two and you'll get the feel for what happens. Yes, our prostate utricular cyst is bright with the B value that is zero because it's a T2-weighted image. There's no diffusion gradients turned on. We don't have any hyperintensity on the right because it's a T2-weighted image, although abate a low resolution T2-weighted image. Now on the right, there is a difference between the two sides. I'll blow it up so you can see it. And no, that's not the utricular cyst. That is real diffusion restriction. That is real diffusion restriction. Let's keep looking. That is real diffusion restriction. B zero, can't see it, B1,600, you can see it. And it will get progressively brighter as the B values go up from zero to 1,600. Let's go down to the area you looked at before. Utricular cyst, utricular cyst goes away on the B1,600. It's got fluid in it, but that fluid is sloshing around. That fluid is moving. So it's not diffusion restricted, but the whole right side of the gland is. You can only see it, B1,600, not B0. Well, that concludes our discussion of Pyrad's designation assessment. In our next session coming up, we're going to talk about the shapes and signal intensities. As we gestalt our way through the prostate gland, we'll look at linear signals, round signals, charcoal signals, lentiform signals, and their shapes. And correlate them very nicely with prostate. And hopefully, your experience and breast tomorrow will help you. Thanks.