Computed Tomographic Findings in Patients With Invasive Fungal Sinusitis

Abstract

Most patients do not have classic CT findings of bone erosion or extrasinus extension in the early course of IFS. We found that severe unilateral thickening of the nasal cavity mucosa was the most consistent finding on CT suggestive of underlying IFS, occurring much more frequently in immunocompromised patients with IFS than without IFS. Even though severe nasal cavity soft tissue thickening is much more common in IFS, this is a nonspecific finding that can be seen, to a lesser degree, in all forms of rhinosinusitis. Therefore, the clinician cannot rely solely on CT imaging and must maintain a high index of suspicion when evaluating immunocompromised patients to establish a prompt diagnosis. Early nasal endoscopy with biopsy and initiation of appropriate therapy are necessary to improve prognosis.

Acute Invasive Fungal Rhinosinusitis: A Comprehensive Update of CT Findings and Design of an Effective Diagnostic Imaging Model

“…8,9 A key attribute of this model is that within our clinical dataset, the involvement of any 2 of the 7 variables predicted AIFR with 100% specificity. The predictive power is also enhanced because 88% of patients with AIFR presented with findings captured by Ն2 variables.…”

“…The predictive power is also enhanced because 88% of patients with AIFR presented with findings captured by Ն2 variables. This model has variables that have been previously ascribed to characteristic imaging findings for AIFR 1,8,10,11 (periantral fat, bone dehiscence, orbital invasion, pterygopalatine fossa), as well as uncommonly described markers for AIFR such as nasolacrimal duct and lacrimal sac involvement. 16,17 The power of the clinical model resides in the aggregate evaluation of all 7 variables because no individual variable had both high PPV and high NPV.…”

“…Bone dehiscence proved to be a specific marker for AIFR (100% specificity) but has low sensitivity (35%), which agrees with previously reported data. 8 Because the fungi tend to spread through vascular channels or along nerves, [18][19][20][21] extension outside of the sinus frequently occurs in the absence of bone destruction. Therefore, bone destruction alone is not a useful exclusionary criterion.…”

“…8 This is noteworthy because of the relatively good prognosis when AIFR is limited to the nasal cavity. 2 Unfortunately, unilateral nasal cavity disease has a low specificity though it is one of the more frequent findings in AIFR (78.6% of patients in our study had unilateral predominant disease).…”

“…9 Our PPV estimates were similar (87% versus 92%). Moreover, our predictive model even produces higher sensitivity, specificity, and NPV than previously reported with CT. 8,9 The NPV is of particular importance in screening studies because low NPV results in erroneously excluding a patient positive for AIFR. Thus, on the basis of our results, CT with application of our predictive model should be considered a primary technique for evaluating AIFR.…”