A Preliminary Study on Sinus Fungus Ball with MicroCT and X-Ray Fluorescence Technique

Area of Science:

• Otolaryngology
• Medical Imaging
• Mycology

Background:

• Sinus fungus ball is a common condition that can lead to severe complications.
• Early diagnosis is crucial for effective treatment and preventing invasive disease.
• Current computed tomography (CT) sensitivity for sinus fungus ball is limited (62%), necessitating investigation into influencing factors.

Purpose of the Study:

• To investigate factors influencing the clinical CT sensitivity for diagnosing sinus fungus ball.
• To explore the origin of zinc ions in sinus fungus balls and their potential role in pathogenesis.
• To analyze the elemental composition of fungal balls and their relationship with CT imaging characteristics.

Main Methods:

• Surgical specimens of fungal balls and sinus mucosa were analyzed using microCT with 5μm resolution.
• Heavy metal elements in the specimens were detected using X-ray fluorescence spectrometry.
• Fungal balls from various sinuses, with or without prior endodontic treatment, were included.

Main Results:

• High concentrations of zinc and calcium were detected in fungal ball specimens compared to sinus mucosa.
• MicroCT revealed particles of varying sizes and densities within fungal balls, resembling CT findings but differing in scale.
• The presence of metallic elements correlated with the appearance of micro-calcifications on CT scans.

Conclusions:

• Spatial resolution is a critical factor affecting the sensitivity of clinical CT for sinus fungus ball detection.
• Enhancing CT resolution could significantly improve diagnostic accuracy.
• Endogenous zinc and calcium, in addition to iatrogenic materials, may contribute to fungal ball growth and CT-visible calcifications.