Ultra-high Resolution Photon Counting Detector Computed Tomography Imaging for Quantitative Lung Assessment: An...

Area of Science:

• Medical Imaging
• Radiology
• Quantitative Imaging

Background:

• Quantitative lung imaging is crucial for disease monitoring and intervention response.
• Photon counting detector-computed tomography (PCD-CT) offers enhanced resolution and reduced artifacts compared to conventional CT.
• Systematic evaluation of PCD-CT's ultra-high resolution for quantitative lung imaging is needed.

Purpose of the Study:

• To evaluate two ultra-high resolution acquisition modes and four reconstruction kernels for optimal quantitative chest imaging.
• To assess measurement stability across different scan modes and kernels at reduced radiation doses.

Main Methods:

• A chest phantom was scanned using PCD-CT with two ultra-high resolution modes (UHRQ+, UHRQSn) and four reconstruction kernels at three radiation doses.
• Quantitative measures including density, airway dimensions, CNR, SNR, and MTF were analyzed.
• Measurement stability was assessed by comparing values at high versus low radiation doses.

Main Results:

• UHRQ+ mode yielded higher CNR, SNR, and MTF values.
• Accurate air measurements across all doses were achieved with UHRQ+ and Qr40 reconstruction.
• Quantitative density measurements were stable (<2% change) with reduced radiation dose.
• Airway measurements were larger with UHRQ+; Br64 reconstruction maintained consistency at low doses (<5% change).

Conclusions:

• UHRQ+ mode is recommended for quantitative lung assessment with PCD-CT.
• Qr40 kernel is optimal for density assessment, and Br64 for airway assessment at ultra-high resolution.
• Quantitative analysis is feasible at 3 mGy with high consistency across tested kernels.