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Hello everyone, Dr. Sidney Levy here.

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3 00:00:03,920 --> 00:00:07,490 I would like to discuss, uh, the imaging

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features of hypopharyngeal squamous cell

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malignancy, and in particular I'd like

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to focus on piriform sinus first up.

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So MRI is often not the first test that will

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be performed for assessment of these lesions

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and it's common to have a CT in the first

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instance, so I will take a moment just to go

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over a protocol for CT, which may be helpful.

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Uh, it is worth, uh, performing an initial

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acquisition in quiet respiration, around

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90 seconds delay after contrast injection

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in order to optimize mucosal enhancement.

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The other feature which can be helpful is a Valsalva

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maneuver, or phonation, performed as a second pass.

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And the purpose of this is to distend the

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piriform sinuses, which can otherwise be

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more difficult to appreciate if collapsed.

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When we do move on to MR, there are some

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general features of these malignancies.

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They tend to be T1 low to intermediate, and T2

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intermediate to high, with a heterogeneous morphology.

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In this case, I have an axial T2 weighted

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sequence without fat suppression or contrast.

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I then have an axial T2 weighted sequence

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with fat suppression, no contrast.

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And on the right, I have a post contrast

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T1 coronal projection with fat suppression.

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These tumors tend to show T1

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low to intermediate signal.

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T2 intermediate to high signal with a heterogeneous

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morphology and mild to moderate enhancement.

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But usually less than the normal enhancement

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of hypopharyngeal or laryngeal mucosa.

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In this case, this tumor is relatively

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hypo-enhancing in its center.

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They may be irregular, infiltrative, or ulcerative.

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They may fill the piriform sinus

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or be circumferential to it.

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This lesion is an ulcerative lesion, which is partially

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filling the sinus, but is really more circumferential

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in relation to the contours of the piriform sinus.

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Whenever we have lesions like this, we must

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make an assessment of involvement or absence of

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involvement of adjacent laryngeal cartilages.

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So in this case, I'd like to draw some

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structures for you to help make that assessment.

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This is the thyroid cartilage here.

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These are the arytenoid cartilages and the

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top of the cricoid cartilage just next to it.

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So now that we've identified those structures,

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we need to make an assessment as to whether

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the tumor is invading those structures.

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The features that we look for are

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most specifically cartilage erosion,

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which is not present in this study.

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We also have a look for abnormal marrow

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enhancement or marrow edema on T2 weighted imaging,

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neither of which are present in this study.

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If there is the suggestion of cartilage involvement, we

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need to make a comment as to whether it has penetrated

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both the inner and outer margins of the cartilage.

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Once we've decided that, we also need to look

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posteriorly and make an assessment of whether

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there is prevertebral invasion or not.

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And for this, we do need to

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look at the sagittal projection.

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Now, in this case, the sagittal

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The projection is only a T1.

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So we will also need to look at the axial projection.

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We are now at the level of the tumor in the axial

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projection with the sagittal to cross-reference.

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Let me draw the tumor once again.

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The structures which we need to look

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for are the retropharyngeal space or

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fat stripe and the prevertebral muscles.

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Now the prevertebral muscles are situated here.

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The prepharyngeal fat stripe is situated,

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whilst this tumor is closely adjacent to the

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retropharyngeal space, it is not seen to clearly

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involve or efface the retropharyngeal space.

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And it does not extend directly

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into prevertebral musculature.

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In our next vignette, we will discuss the patterns

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of nodal drainage and spread of these tumors.