Fungal sinusitis - imaging findings

Brief description with key imaging findings allowing differential diagnosis of various forms of fungal sinusits.
From Radiopaedia.org and Diagnostic Imaging: Head and Neck by H. Ric, Harnsberger.

1. Fungal sinusitis Imaging findings Maria Cucos MD

2. forms allergic (AFS) chronic noninvasive (CNFS) chronic invasive (CIFS) acute invasive (AIFS) Maria Cucos MD

3. allergic fungal sinusitis Maria Cucos MD

4. chronic severe noninvasive form immunocompetent , nondiabetic atopic patient, asthma long-standing symptoms of chronic RS facial deformity, diplopia serum eosinophilia , elevated IgE Maria Cucos MD

5. CT with soft tissue and bone window best multiple sinuses , ethmoid > maxillary hyperdense nonenhancing material peripheral mucosa enhances bone expansion +/- erosion Maria Cucos MD

6. DDX expansile sinonasal lesion allergic fungal sinusitis sinonasal poliposis antrochonal polyp mucocele esthesioneuroblastoma Maria Cucos MD

7. Remember symptomatic atopic patient increased density in multiple sinuses with bone expansion use soft tissue window to assess density of secretions Maria Cucos MD

8. chronic noninvasive fungal sinusitis Maria Cucos MD

9. also called mycetoma , fungus ball, aspergilloma immunocompetent non-atopic minimally symptomatic Maria Cucos MD

10. 1 sinus , commonly maxillary with high density mass with Ca++ which may be ovoid or conform to sinus shape a/w chronic osteitis fungus ball is hypo T1, hypo T2 coronal NECT best Maria Cucos MD

11. DDX chronic rhinosinusitis less likely to appear mass like affects > 1 sinus Ca++ more rare allergic fungal sinusitis atopy high density material, low T1, T2 but with bone expansion Maria Cucos MD

12. chronic invasive fungal sinusitis Maria Cucos MD

13. the same as chronic noninvasive fungal sinusitis high density material + chronic osteitis + invasiveness of fungal mass extrasinus extension +/- bone erosion Maria Cucos MD

14. acute invasive fungal sinusitis Maria Cucos MD

15. acute onset in immunosuppressed patient spread occurs via vascular invasion can be fatal Maria Cucos MD

16. dense secretions bone destruction ill-defined spread to soft tissues pterygopalatine fossa , masticator space, infratemporal fossa orbit, intracranial fossa ! infiltration of fat planes can be present w/o bone erosion via vascular channels Maria Cucos MD

17. CECT with soft tissue and bone window soft tissue and muscles may enhance MRI, T1+C FS if suspected orbital and intracranial complications leptomeningitis , epidural abscess, subdural empyema , brain abscess MRA, MRV arterial pseudoaneuryrsm , thrombosis, dissection + brain ischemia cavernous sinus thrombosis ! always look at cavernous sinus, cavernous ICA, and basilar artery with sphenoid sinusitis Maria Cucos MD

18. DDX destructive sinonasal lesion with soft tissue involvement acute invasive fungal sinusitis acute rhinosinusitis chronic invasive fungal sinusitis granulomatosis with polyangiitis (Wegener’s) sinonasal lymphoma sinonasal carcinoma Maria Cucos MD

19. Questions to ask with fungal sinusitis is the patient immunosuppressed ? is the patient atopic ? is the patient symptomatic ? one or more sinuses involved? Maria Cucos MD

20. Maria Cucos MD allergic fungal sinusitis chronic noninvasive fungal sinusitis atopy , asthma chronic symptoms multiple sinuses, ethmoidal + hyperdense material bone expansion +/- erosion noninvasive immunocompetent /mildly immunosuppressed mildly symptomatic one sinus, maxillary + hyperdense material osteosclerosis +/- volume reduction noninvasive chronic invasive fungal sinusitis acute invasive fungal sinusitis diabetic patient chronic symptoms hyperdense material osteosclerosis + bone erosions extra - sinus invasion immunosuppressed , diabetic acute dramatic symptoms hyperdense material less prominent bone erosions, no osteosclerosis extra-sinus invasion

21. Remember context is important consider AIFS in immunosupressed and diabetic patients consider CNFS in immunocompetent patients or only mildly immunosuppressed Maria Cucos MD

22. Remember always look for signs of invasive disease soft tissue infiltration/invasion bone destruction Maria Cucos MD

23. Remember consider AIFS in immunosuppressed patient with maxillary disease + infiltrated periantral fat even if no bone erosion is present Maria Cucos MD