Interactive Transcript
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Dr. Finazzo, this is a 62-year-old woman who had a CT.
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3 00:00:04,880 --> 00:00:07,770 Here's the coronal reformat demonstrating a
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mass in the right kidney with some nodularity
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that enhances inferiorly, a somewhat
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cystic, but not a pure cyst, obviously.
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Uh, mass with nodularity in
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the upper part of the lesion.
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So, why do we do an MRI in this case?
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What are the biomarkers that we're
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looking for to enhance diagnosis?
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Yeah, so in here, uh, already, the fact that
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there's an enhancing component already places
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this at high risk of being a renal cell carcinoma.
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And as we know, renal cell carcinoma cancers
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can invade vein and can have metastatic disease.
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And even though we want to think that CT is good
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to look at METs, the MR really adds a little bit
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better value, especially to look at small mesenteric
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lesions, or lesions that tend to fall into the
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pericardial gutters, and small hepatic lesions.
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But when we're talking about the actual
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lesion itself, we can potentially offer some
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histologic grading by using the diffusion
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weighted images to look for central necrosis.
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If a higher aggressive clear cell RCC is more
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aggressive, it will have diffusion restriction.
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But in this case, we do see that we have a
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complex cystic lesion, uh, in the right kidney,
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which demonstrates strong arterial enhancement
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on the early phase and areas of nodularity.
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Uh, and then when we actually zoom down on this
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image, we can look at the rest of the abdomen
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to look for subtle lesions in the kidney.
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This one we, I already know is a cyst because I've
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already reviewed the case, but it's small renal
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lesions can present that small and
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we're looking for ring-enhancing lesions
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similar to the primary tumor in the liver.
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We look at the renal vein and the portal vein to
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make sure, I'm sorry, the renal vein and the IVC,
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to make sure that we don't have any venous involvement.
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And we really try to scrutinize
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the, uh, retroperitoneum.
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And while I'm on the post-contrast images,
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I do a quick search of the spine to make
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sure we don't have any metastatic lesions.
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And I look at the soft tissues, which is why we
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like to use fat-suppressed, uh, post-contrast
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imaging because renal cell carcinoma lesions will
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light up like a light bulb in the soft tissues.
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Yeah, and they do like the soft tissues, and
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it's also one of the hypervascular metastases.
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And I have been burned on CT, whereas on CT, you know,
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you, you have the cava, and the cava has enhancement.
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So if you put inside that a very
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hypervascular lesion, it's enhancing.
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It blends right in with the contrast in the
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flowing blood, and you can actually miss it.
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Whereas on a non-contrast MRI, you've got fast flow,
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but if you put a solid lesion inside without giving
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any contrast, you're going to see a solid-looking
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round defect that may be adherent to the wall.
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So actually in my experience, renal vein invasion
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and caval invasion is much more easily seen
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on MRI than it is on contrast-enhanced CT.
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One last caveat you've mentioned to me on numerous
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occasions throughout these vignettes, it's the
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Bosniak classification, so that our colleagues
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don't have to fumble through it.
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We will post that at the end of this vignette.
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Alright, P and P out.
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