Dose Reduction for Sinus and Temporal Bone Imaging Using Photon-Counting Detector CT With an Additional Tin Filter.

Area of Science:

• Medical Imaging
• Radiology
• Photon-Counting Detector Technology

Background:

• Conventional energy-integrating detector (EID) CT exposes patients to radiation, necessitating dose reduction strategies.
• Photon-counting detector (PCD) CT offers potential for improved image quality and lower radiation doses.
• The use of tin (Sn) filtration in conjunction with PCD-CT is explored for optimizing radiation dose in head imaging.

Purpose of the Study:

• To quantitatively assess radiation dose reduction in sinus and temporal bone examinations using PCD-CT with an additional tin (Sn) filter.
• To compare image quality and diagnostic performance between PCD-CT and conventional EID-CT.
• To evaluate the potential of ultra-high-resolution PCD-CT for enhanced anatomical delineation.

Main Methods:

• Scans were performed on phantoms and cadaver heads using a research PCD-CT scanner (Sn-100 kV) and a commercial EID-CT scanner.
• Patient studies included 30 sinus and 2 temporal bone examinations, comparing low-dose PCD-CT protocols with standard clinical EID-CT.
• Image analysis involved quantitative measurements of contrast, noise, and spatial resolution, alongside subjective assessment of anatomical structure visualization by a neuroradiologist.

Main Results:

• PCD-CT with Sn-100 kV demonstrated significant dose reductions: 56% in phantom studies, 67% for sinus, and 83% for temporal bone examinations compared to EID-CT.
• Low-dose PCD-CT (10 and 8 mGy) showed superior visualization of critical sinus structures compared to clinical EID-CT.
• PCD-CT achieved up to 85% dose reduction in temporal bone imaging with comparable visualization of inner ear structures.

Conclusions:

• Sn-100 kV PCD-CT effectively reduces radiation dose for sinus and temporal bone imaging while preserving image contrast.
• Dose reduction was validated in patient studies, with PCD-CT offering significant benefits.
• The ultra-high resolution capability of PCD-CT enhances anatomical delineation in sinus imaging beyond current clinical standards.