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Let's start with our first case,

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and this is a patient who had back pain.

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These are the pulse sequences that I mentioned that we

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typically perform as part of our routine

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for evaluation of spinal lesions.

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What you're seeing here is the sagittal T1-weighted

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scan, the sagittal T2-weighted scan, and the STIR image.

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And remember that the STIR image is the one that has

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some application of a suppressor technique for the fat,

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as opposed to the traditional T2-weighted scan,

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and it gives you a wider range for the contrast.

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In this examination,

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we see that there is a mass at the

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L4 level within the thecal sac.

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This is nicely demonstrated on the T2-weighted scan,

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in that we can actually see the edges of the dura here,

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identifying this as an intradural lesion.

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Then we make the distinction that this

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is not within the spinal cord,

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which ends up here at...

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around the L1 level.

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So, therefore, it's intradural but extramedullary.

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We are in the lumbar region.

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We are looking at a cystic lesion in the lumbar region.

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Cystic lesion, lumbar region, intradural extramedullary,

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far and away, we're going to say that this is most likely

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going to be a Schwannoma.

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However, we want to see the post-gadolinium enhanced

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sequences to ensure that it will enhance.

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Almost all Schwannomas will enhance except

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for those that are completely cystic.

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This one does have some solid portions that we would

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expect would demonstrate contrast enhancement.

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The additional sequences that we're going to look at

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will be our T2-weighted axial scan and our sagittal

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post-gadolinium enhanced scan and our axial post-gadolinium

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enhanced scan. As we scroll through the images,

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we come upon the lesion,

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which again is demonstrated to be within the thecal sac,

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showing both cystic, as well as solid portions.

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Note that there are these bright areas on the T2-weighted scan,

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which are usually going to be ascribed to

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cystic portions. And then we have our darker area,

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which is going to be more solid.

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As we scroll through the T1-weighted

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sequences, after gadolinium,

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we see that this lesion does indeed show contrast

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enhancement with a more solid posterior component

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and with the more cystic areas above and below.

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On the axial scans, we see, as we scroll toward the edges

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of the lesion, the more cystic component you see above,

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coming into the more solid component centrally.

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And then as we go further inferiorly,

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we come into the more cystic component.

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So our summary of this case would be a solitary,

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intradural, extramedullary, partially cystic,

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partially solid mass,

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most likely representing a Schwannoma.

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I would probably not include anything else in

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the differential diagnosis for this case.