[Imaging quality and dosage in ENT--what do we really need?]

Area of Science:

• Radiology
• Medical Imaging
• Radiation Oncology

Background:

• Computed tomography (CT) is standard for preoperative imaging of the nose, paranasal sinuses, and temporal bone.
• Reducing radiation dosage is crucial for patient safety and necessitates research into maintaining imaging quality.
• This study focuses on anatomical checklists and imaging quality analysis of the anterior and lateral skull base.

Purpose of the Study:

• To evaluate the impact of varying radiation dosages on the imaging quality of the nose, paranasal sinuses, and temporal bone using cone beam CT.
• To determine optimal radiation dose ranges for achieving excellent imaging quality in these anatomical regions.
• To establish the feasibility of dose reduction in skull base imaging.

Main Methods:

• Over 400 cone beam CT examinations were performed on three human heads with adjusted X-ray tube settings.
• Thirty-one anatomical parameters were assessed for image quality (Excellent, well, poor, not evaluable).
• A summation score was calculated for each examination to quantify overall imaging quality.

Main Results:

• Excellent imaging quality was consistently observed at high radiation dosages for both paranasal sinuses and temporal bone.
• A reduction in imaging quality was noted at lower dosages.
• Optimal dose ranges were identified: 2.0–3.0 mGy for paranasal sinuses and 3.0–4.0 mGy for temporal bone.
• Significant dose reduction of 70-80% compared to current highest settings is achievable, with approximately 50% reduction compared to standard protocols.

Conclusions:

• Radiation dose reduction is feasible in CT imaging of the nose, paranasal sinuses, and temporal bone.
• Defining necessary imaging quality from a clinical perspective allows for significant dose reduction.
• This research supports the implementation of lower-dose protocols without compromising diagnostic accuracy for skull base imaging.