Imaging Features Distinguishing Maxillary Hemosinus From Chronic Desiccated Secretions
Noncontrast paranasal sinus CT is the first-line test for differentiating high-attenuation sinonasal content. Hemosinus is typically characterized by blood-product density that is often higher and more “clotted/blood-like” than chronic desiccated secretions. [1], [2]
Computed Tomography Attenuation Patterns
- Hemosinus (blood products) should raise suspicion when intrasinus content demonstrates marked hyperattenuation consistent with clotted blood. (pdfs.semanticscholar.org)
- Chronic desiccated secretions (inspissated mucus) are typically lower-attenuation than acute blood and often fall into a lower chronic viscosity range on CT (radiodensity examples reported for sinus secretions). (radlines.org)
- CT attenuation can overlap between these entities. The most useful CT discrimination is made by combining attenuation with other sign patterns rather than HU alone. (radlines.org)
Computed Tomography Distribution and Compartment Behavior
- Hemosinus is expected to behave like intraluminal blood accumulation and may show layering and/or air–fluid level behavior when a mixture of fluid components is present. (pdfs.semanticscholar.org)
- Chronic desiccated secretions are expected to be viscous, non-purulent chronic material that tends to produce persistent high attenuation without a typical acute blood layering pattern. (ajnr.org)
Magnetic Resonance Susceptibility Behavior
- Blood products demonstrate susceptibility effects on susceptibility-sensitive MRI sequences, which can produce a blooming artifact pattern. (pmc.ncbi.nlm.nih.gov)
- Desiccated secretions generally do not show the same degree of susceptibility blooming as blood products. This distinction is a practical use of susceptibility-weighted imaging logic for differentiating paramagnetic blood degradation products from other high-signal/increased-density contents. (pmc.ncbi.nlm.nih.gov)
Contrast Enhancement Characteristics
- Desiccated secretions are typically evaluated on CT primarily as attenuation content rather than a vascular enhancing lesion. (ajnr.org)
- Blood products may be supported by susceptibility behavior and CT clotted-blood attenuation patterns rather than relying on enhancement patterns alone. (pdfs.semanticscholar.org)
Practical Imaging Algorithm
- Step 1: Perform noncontrast CT and evaluate HU/attenuation of the maxillary sinus content. (radlines.org)
- Step 2: If CT shows uncertainty or if clinical urgency exists for hemorrhage, add susceptibility-sensitive MRI (SWI/SWAN or equivalent) to assess for blooming consistent with blood products. (pmc.ncbi.nlm.nih.gov)
- Step 3: Combine CT attenuation plus susceptibility findings with expected sinus content behavior over time. (radlines.org)
Common Sources of Diagnostic Confusion
- Fungal concretions can also produce marked hyperattenuation on CT and can confound reliance on CT density alone. (pmc.ncbi.nlm.nih.gov)
- Susceptibility-based MRI can help separate blood-product susceptibility from calcification-like or other mineralization-related contents, because susceptibility can differ by tissue class. (pubmed.ncbi.nlm.nih.gov)
Key Distinguishing Signs
- Favor hemosinus when CT attenuation is consistent with clotted blood range and when susceptibility-weighted MRI shows blood-product blooming. (pdfs.semanticscholar.org)
- Favor chronic desiccated secretions when CT attenuation matches the chronic inspissated-viscosity range and when susceptibility blooming is not prominent relative to blood-product expectations. (radlines.org)