From the Guidelines
In suspected sinusitis, the radiological appearance of paranasal sinuses typically reveals mucosal thickening, air-fluid levels, and complete opacification of the affected sinuses, with CT scans being the gold standard imaging modality, as stated in the most recent study 1. The radiological findings in suspected sinusitis can vary depending on the type of sinusitis.
- Acute sinusitis typically shows air-fluid levels, while
- chronic sinusitis demonstrates mucosal thickening and polypoid changes, as noted in 1. CT scans show these findings with high sensitivity, demonstrating sinus wall thickening, obstruction of the ostiomeatal complex, and potential bone erosion in chronic cases, as seen in 1. MRI may be used to differentiate between inflammatory changes and neoplasms, showing T2 hyperintensity in inflamed sinuses, as mentioned in 1. Plain radiographs, though less commonly used now, may show mucosal thickening and opacification but lack sensitivity compared to CT, as stated in 1. The European Position Paper on Rhinosinusitis and Nasal Polyps 2020 also recommends CT scan as the gold standard in the radiologic evaluation of rhinologic disease, notably CRS, as noted in 1. These imaging findings help confirm the diagnosis of sinusitis when clinical symptoms are present, though it's essential to note that incidental mucosal thickening can occur in asymptomatic individuals, particularly during upper respiratory infections, as mentioned in 1. The use of imaging modalities such as CT and MRI is crucial in diagnosing and managing sinusitis, especially in cases where complications or alternative diagnoses are suspected, as stated in 1.
From the Research
Radiology Appearance of Paranasal Sinuses in Suspected Sinusitis
The radiology appearance of paranasal sinuses in suspected sinusitis can be evaluated using various imaging modalities, including:
- Plain X-ray: used as a screening procedure, but has limited role in management of sinusitis 2
- Computed Tomography (CT): provides good bone detail and soft tissue imaging, and is typically reserved for difficult cases or to define anatomy prior to sinus surgery 3, 4, 2
- Magnetic Resonance Imaging (MRI): used to differentiate soft-tissue structures, such as in cases of suspected fungal infection or neoplasm, and is more accurate than CT in determining diagnosis of intracranial complications 3, 2, 5
- Magnetic Resonance (MR) with Gadolinium (Gd DTPA): improves accuracy of MR imaging and is useful in identifying soft tissues and showing bone changes 3
Imaging Findings
Imaging findings of paranasal sinuses in suspected sinusitis may include:
- Air-fluid levels and complete opacification of a sinus, which are more specific for sinusitis, but only seen in 60% of cases 2
- Mucosal thickening, polyps, and other sinus abnormalities, which can be seen in 40% of symptomatic adults, but require clinical correlation to avoid overdiagnosis of sinusitis 2
- CT findings of patients with intracranial or orbital infection of sinusitis, which include unilateral ethmoiditis and meningitis 5
Choice of Imaging Modality
The choice of imaging modality depends on the clinical presentation and suspected complications of sinusitis. CT remains the standard modality for diagnosing sinusitis, but MRI is frequently necessary, especially for patients with intracranial complications 5. Recent advances in PET/CT imaging have introduced a physiologic aspect to anatomical imaging and hold promise to better stage and restage head and neck tumors 6.