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11 Cards in this Set
- Front
- Back
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How is a primary neoplasm different from a secondary neoplasm?
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Primary = tumor from the cell of origin (and in that area)
Secondary = metastases |
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In terms of "mass effect", what does a vasogenic edema or tumor do?
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Vasogenic edema will PUSH on things, distorting their shape and/or location.
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In terms of "mass effect", what does gliosis do? While you're at it, what's a gliosis?
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Gliosis is scarring of glial cells.
They tend to PULL on things |
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What's a duret hemorrhage?
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Duret hemorrhages are a bad sign. They result from central tentorial herniations --> bleeding into the brainstem. Check it out (yellow arrow).
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What's this tumor (medulloblastoma) doing in terms of mass effect?
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It's pushing up! The ventricles are all squished and dilated. On an axial section, the ventricles look very enlarged and dilated. This here is a saggital view, but you can see that the ventricles have been pushed up.
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Do tumors have higher or lower cell density? How does this show up on a no-contrast-CT (NCCT)?
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Higher cell density and increased % mitoses.
On NCCT, you will notice a hyperdense area (brigther) |
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Is this a normal or abnormal MR-spectroscopy? How do you know?
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That's a normal one. Notice the 3 peaks:
- Choline - Creatine - NAA |
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For MR-Spectroscopy, what do these peaks represent?
1. Choline 2. Creatine 3. NAA |
1. Choline is a MEMBRANE MARKER (# cells)
2. Creatine is a METABOLISM MARKER 3. NAA is a NEURONAL MARKER (# neurons) |
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This is an abnormal MRS. How do you know (ignore the label)?
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The peaks are going down "stock market crashing".
Choline is higher --> hypercellular NAA is lower --> fewer neuronal |
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In tumors, do you have higher or lower capillary density? What image can show this the best?
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You have increased relative blood volume supplying that area. Can be seen on MR-Perfusion Weighted Imaging.
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Why do tumors have areas of necrosis? How can this be measured by spectroscopy?
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The cells grow so fast they outgrow their blood supplying, leaving a necrotic core.
On spectroscopy, this can be seen with a LACTATE PEAK, which represents anaerobic glycolysis. On a contrast-enhanced MRI (Gd), you will see a rim-enhancement pattern. |
