Sinuses (Dr. Collins) Flashcards
ACR appropriateness criteria for acute (< 4 weeks) uncomplicated rhinosinusitis
No imaging necessary
CT sinus without has a grade of 4
ACR appropriateness criteria for recurrent sinusitis, or preoperative planning
CT sinus without contrast (grade of 9)
ACR appropriateness criteria for acute sinusitis with suspected orbital or intracranial involvement
MRI maxillofacial with contrast
ACR appropriateness criteria for sinonasal obstruction with a suspected mass
MRI maxillofacial with contrast (for diagnosis)
+
CT sinus without contrast (for operative planning)
ACR appropriateness criteria for suspected invasive fungal sinusitis
MRI maxillofacial with contrast
CT sinus without contrast main protocol
0.625 mm slices
1-2 mm reconstructions
3-planes of bone window
3-planes of soft tissue window
What structure separates the anterior and posterior divisions of the ethmoid sinus?
Basal lamella
In what percentage of cases are air-fluid levels seen in clinically apparent acute sinusitis?
25-50% (nonspecific)
Main imaging findings of acute sinusitis (3)
Sinus opacification with air fluid levels
Frothy secretions
Hyperenhancing mucosa
Risk factors for acute sinusitis in ICU patients (2)
Prolonged stay
Indwelling tubes
(May account for 5-10% of sepsis in ICU patients with unknown source)
Most likely diagnosis of a patient with rapid onset headache, altered mental status and seizures, with diffuse subdural diffusion restriction on MRI?
Subdural empyema
Usually will have enhancement and multiple abscesses along the dura
Most common pattern of chronic obstructive sinus disease?
Infundibular
Diagnosis of chronic sinusitis requires the presence of symptoms for how long?
> 12 weeks
Imaging findings often do not correlate with symptom severity
Chronic disease associated with sinonasal polyps
Cystic fibrosis
Chronic disease associated with allergic fungal sinusitis
Asthma
Characteristic MRI finding in a patient with allergic fungal sinusitis
Blooming susceptibility artifact
metal aggregates within inspissated fungal secretions
Most essential part of treating invasive fungal sinusitis
Surgical debridement
Most likely diagnosis in a patient with rapid onset fever, sinus pain and epistaxis in an immunocompromised patient?
Invasive fungal sinusitis (mucor)
Findings on contrast-enhanced MRI in a patient with invasive fungal sinusitis
Non-enhancing mucosa (infarcted tissue)
Most frequent paranasal sinus associated with a mucocele
Frontal sinus (65%)
ethmoid sinus next most common, 25%
What diseases are associated with mucoceles (2)?
Cystic fibrosis
Chronic non-invasive fungal sinusitis
Feature most predictive of post resection recurrence in juvenile nasopharyngeal angiofibroma
Skull base involvement
Most likely diagnosis in a teenage male patient with nasal obstruction, profuse epistaxis and otomastoidosis
Juvenile nasopharyngeal angiofibroma
benign, locally aggressive tumor with significant vascularity
Which nuclear medicine scan can theoretically be used to diagnose an olfactory neuroblastoma?
I123-MIBG
Inverted papilloma is associated with malignant transformation into what?
Squamous cell carcinoma
Cerebriform pattern of enhancement on MRI
Inverted papilloma
Most common sinonasal tumor
Squamous cell carcinoma
perineural tumor spread
What is intrinsically T1 hyperintense (4)?
Methemoglobin
Manganese
Neurohypophysis
Paramagnetic substances
(also think about melanoma)
