MRI Orbits, Face, and Neck MRI is not useful as the first-line study for routine sinus imaging because of the lack of bony detail. In addition, inspissated secretions may demonstrate a signal void that mimics air on T2-weighted sequences [39]. However, one study examined 89 adult patients imaged with both CT and MRI within a 3-month period for evaluation of pituitary disease and showed significant correlation between CT and MRI based Lund-Mackay staging scores of sinus disease; T1- and T2-weighted sequences were utilized for MRI scoring [40]. The utilization of IV contrast was not specified, and the Lund-Mackay scores were not correlated with patient symptoms in this study. In select cases, evaluation with MRI without and with IV contrast may be helpful to differentiate fluid secretions from inflamed mucosa and exclude an underlying obstructing mass [24]. Radiography Paranasal Sinuses Detection of mucosal thickening is limited on radiography because of overlapping osseous structures [41]. CT has largely replaced radiography given its superior depiction of sinonasal anatomy and pathology and the need for greater anatomic detail for functional endoscopic sinus surgery planning [2,41]. SPECT or SPECT/CT Paranasal Sinuses In a pilot study of 24 patients with CRS, a positive SPECT correlated with more extensive disease on CT and poor subjective response to medical treatment [42]. However, the use of SPECT remains limited in the evaluation of CRS, and this technique is generally not used in clinical practice. Variant 4: Acute sinusitis with rapid progression or suspected invasive fungal sinusitis. Initial imaging. Acute invasive fungal sinusitis is a fungal infection of the paranasal sinuses with a rapid time course of <4 weeks [4] and a high mortality rate of 50% to 80% [5,6].
Sinonasal Disease. MRI Orbits, Face, and Neck MRI is not useful as the first-line study for routine sinus imaging because of the lack of bony detail. In addition, inspissated secretions may demonstrate a signal void that mimics air on T2-weighted sequences [39]. However, one study examined 89 adult patients imaged with both CT and MRI within a 3-month period for evaluation of pituitary disease and showed significant correlation between CT and MRI based Lund-Mackay staging scores of sinus disease; T1- and T2-weighted sequences were utilized for MRI scoring [40]. The utilization of IV contrast was not specified, and the Lund-Mackay scores were not correlated with patient symptoms in this study. In select cases, evaluation with MRI without and with IV contrast may be helpful to differentiate fluid secretions from inflamed mucosa and exclude an underlying obstructing mass [24]. Radiography Paranasal Sinuses Detection of mucosal thickening is limited on radiography because of overlapping osseous structures [41]. CT has largely replaced radiography given its superior depiction of sinonasal anatomy and pathology and the need for greater anatomic detail for functional endoscopic sinus surgery planning [2,41]. SPECT or SPECT/CT Paranasal Sinuses In a pilot study of 24 patients with CRS, a positive SPECT correlated with more extensive disease on CT and poor subjective response to medical treatment [42]. However, the use of SPECT remains limited in the evaluation of CRS, and this technique is generally not used in clinical practice. Variant 4: Acute sinusitis with rapid progression or suspected invasive fungal sinusitis. Initial imaging. Acute invasive fungal sinusitis is a fungal infection of the paranasal sinuses with a rapid time course of <4 weeks [4] and a high mortality rate of 50% to 80% [5,6].