Low-dose CT of the abdomen: Initial experience on a novel photon-counting detector CT and comparison with energy-integrating detector CT

Purpose: To analyze the quantitative and qualitative image quality of low-dose CT scans of the abdomen on a novel photon-counting detector CT (PCD-CT) in comparison with a traditional energy-integrating detector CT (EID-CT). Methods: Consecutive patients with clinically indicated low-dose CT were scanned on a PCD-CT and compared with a BMI-matched EID-CT-cohort scanned during the same timeframe. Radiation dose, image noise, and signalto-noise ratio (SNR) were measured for each patient. Furthermore, image quality and conspicuity of abdominal structures (adrenal glands, mesenteric vessels, ureters, and renal pelvis) were assessed on 5-point Likert-scales (1 = very poor quality/not detectable; 5 = excellent quality/differentiability). Results: Twenty patients (mean age 46.2 [range: 19-77]; 13 men) were included. Image noise was significantly lower (24.9 +/- 3.3 vs. 31.4 +/- 5.6 SD HU, p < 0.001) and SNR significantly higher (2.1 +/- 0.3 vs. 1.5 +/- 0.4; p < 0.001) on the PCD-CT. Subjective image quality was substantially higher (4.0 +/- 0.3 vs. 3.1 +/- 0.6; p < 0.001) and conspicuity better for the renal pelvis, ureters, and mesenteric vessels on the PCD-CT. There was no significant difference in the conspicuity of the adrenal glands. With increasing BMI (1st-4th BMI quartile), noise increased, and SNR decreased more strongly on the EID-CT than on the PCD-CT (Delta Noise: 39% vs. 2%, Delta SNR: -33% vs. -7% for EID-CT vs. PCD-CT, respectively) while radiation dose increased comparably (70 vs. 59%). Conclusions: Low-dose CT scans of the abdomen performed on a novel PCD-CT exhibit reduced noise, higher SNR, increased subjective image quality, and superior conspicuity of abdominal fine structures compared to scans in comparable patients on an EID-CT.

Automated summary

This study compared the quantitative and qualitative image quality of a novel PCD-CT and a traditional EID-CT in low-dose CT scans of the abdomen. The results showed that the PCD-CT had lower image noise, higher SNR, improved subjective image quality, and better conspicuity of abdominal fine structures compared to the EID-CT.