MRI of the nasal cavity, the paranasal sinuses and orbits in Wegener's granulomatosis

Abstract

The purpose of this study was to evaluate diagnostic MRI criteria in Wegener's granulomatosis of the nasal cavity, the paranasal sinuses and orbits. Between March 1991 and January 1996, 62 patients with biopsy-proven Wegener's granulomatosis were studied with T1- and T2-weighted spin-echo (SE) sequences. In 32 patients coronal postcontrast T1-weighted images were obtained. Mucosal thickening of the nasal cavity and paranasal sinuses was demonstrated as high-intensity lesions on T2-weighted SE sequences in 57 patients (92%). Of this group, inflammatory granulomatous tissue was found on biopsy in 30 patients (48%) in the nasal cavity and in 4 patients (6%) in the paranasal sinuses. In 23 patients (37%) biopsy revealed unspecific inflammatory changes without evidence of granulomatous tissue. In 14 patients (23%) granulomas were depicted as low-signal intensity lesions on T1- and T2-weighted SE sequences in the paranasal sinuses and orbits. In 5 patients (8%) osseous destruction was found. After gadolinium injection, 12 of 14 granulomas showed inhomogeneous signal enhancement. In two granulomas no enhancement was found. The MRI technique is helpful in the diagnosis of patients with Wegener's granulomatosis. In the initial inflammatory process of Wegener's granulomatosis, it is not possible to differentiate between mucosal inflammation and granulomatous tissue in MRI. In the later stage of granulomatous transformation, granulomas can be depicted as low-signal-intensity lesions. Therefore, Wegener's granulomatosis should be included in the differential diagnosis of patients with low-signal-intensity lesions on T1- and T2-weighted SE sequences of the nasal cavity, paranasal sinuses and orbits.

Manifestações otorrinolaringológicas nas doenças reumáticas auto-imunes

“…Granulomas podem ser detectados como lesões de baixo sinal em T1 e T2 em ressonância nuclear magnética (RNM) da cavidade nasal ou seios paranasais. O envolvimento intraorbitário da GW é usualmente acompanhado de doença do seio paranasal e um hiposinal em T2 na RNM é útil no diagnóstico (20,21) . Obstrução do ducto nasolacrimal e um aumento das glân-dulas lacrimais também pode ocorrer.…”

Localised Wegener’s Granulomatosis in Otolaryngology: A Review of Six Cases

“…In early lesions, it is not possible to differentiate between mucosal inflammation and granulomatous tissue. However, in later stages granulomas can be seen as low signal intensity lesions on the scan [29]. A CT scan may be helpful in cases of bony destruction and intracranial extension of nasal lesions.…”

Imaging Features of Granulomatosis with Polyangiitis (Wegener’s)

“…Therefore, a CT scan is performed without contrast agent, using a bone filter, with axial, coronal, and sagittal reformatting. However, MRI is indicated when invasion of granuloma through the orbit or the pterygopalatine fossa is suspected clinically or on CT images (Courcoutsakis et al 1997;Muhle et al 1997;Provenzale et al 1996).…”