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

1. Rhinosinusitis: acute, chronic,
and complications
Imaging findings

2. Acute rhinosinusitis

3. key imaging findings
foam on the water – bubbly secretions
air-fluid levels – provided no recent nasal lavage, no NG tube
+ mucosal thickening – enhances; central secretions do not
+ normal sinus lumen size
no expansion, unlike mucocele
no reduced volume, unlike chronic RS

4. coronal CT bone window best
patient prone
neck extended to keep mobile secretions away from
osteomeatal complex (OMC)

5. coronal CT bone window – look for a cause of the RS
obstructive secretions or obstructive mass
at the OMC – mass may show increased density
compared to trapped fluid and will enhance on CECT
anatomic variations as cause of RS

6. MRI + C
not routinely
orbital and intracranial complications
DDX fungal disease vs. other inflammatory disease
DDX inflammatory disease vs. neoplasm

7. Acute RS complications

8. periorbital – more common in children
preseptal cellulitis , abscess
subperiostal postseptal abscess
optic neuritis

9. intracranial
meningitis
epidural abscess
subdural empyema – frontal, ethmoidal sinusitis
cerebritis, brain abscess – frontal sinusitis
cavernous sinus thrombosis

10. superficial – more common in chronic RS
osteomyelitis
subgaleal abscess (Pott puffy tumor) – frontal sinusitis

11. subperiostal postseptal abscess
secondary to ethmoiditis
in medial extraconal space, near medial rectus muscle
swelling of medial rectus
dehiscence of lamina papyracea
peripheral enhancement + central low density
enhancement may be solid
surrounding fat infiltration

12. cavernous sinus thrombosis
enlarged cavernous sinus with convex lateral margin
with heterogeneous enh
enlarged or thrombosed superior ophthalmic vein
compare size and shape with contralateral sinus
extraocular muscles enlarged from venous congestion
cavernous carotid narrowed

13. CE CT best for subperiostal postseptal abscess
CE MRI best for intracranial complications

14. Chronic rhinosinusitis

15. key imaging findings
chronic osteitis
thickened sclerotic sinus wall with reduced sinus lumen
concavity of sinus walls preserved
+ secretions of variable density, may be dense, calcified
+ mucosal thickening, with possible enhancement

16. coronal CT best
prone with neck extended
coronal plane perpendicular to palate
MRI
secretions show variable signal intensity
may be high T1 and low T2, mimicking air on T2
 best seen on T1

17. Remember
nonenhanced CT bone window best for
rhinosinusitis without suspected complication
CE MRI recommended only if suspected orbital
or intracranial complication

18. Remember
look at density of secretions, if dense
think of chronic or fungal sinusitis
! look for bone erosions to make sure
you’re not missing subtle malignant lesion

19. Remember
always look for complications of acute
and chronic sinusitis

20. Remember
look for orbital subperiostal abscess
in children with acute ethmoidal sinusitis

21. Remember
look at cavernous sinus and ICA
with sphenoidal sinusitis