Black turbinate sign (nasal cavity)
The black turbinate sign refers to the non-enhancement of nasal turbinates in a patient with acute invasive fungal rhinosinusitis.
Angioinvasive fungal infection (e.g. mucormycosis or aspergillosis) involves the nasal mucosa and causes infarction of the surrounding tissue. The infarcted tissue is non-enhancing on contrast-enhanced MRI and may show diffusion restriction. In comparison, non-infarcted inflamed mucosa shows contrast enhancement.
This sign is important for the early detection of invasive fungal rhinosinusitis . However, the sign is not entirely specific as it has been observed in immunocompetent individuals with essentially no chance of invasive fungal rhinosinusitis . Thus, correlation with clinical history is important for accurate interpretation. Features of benign black turbinates include progressive enhancement on delayed sequences, preserved thin peripheral mucosal enhancement, and thin internal septations .
See also
