High-resolution photon-counting detector computed tomography (PCD CT UHR) provides significantly enhanced characterization and quantification of coronary plaque in comparison to energy-integrating detector (EID) CT, according to new research.
For the prospective study, recently published in Radiology, researchers reviewed data from 48 participants (164 total plaques) who had coronary CT angiography (CCTA) in order to assess difference between ultra-high spatial resolution PCD CT and EID CT.
The study authors found that significantly lower total plaque volume on PCD CT UHR (723.5 mm3) in comparison to EID CT (1084.7 mm3). Researchers also noted over a 49 percent reduction in fibrotic plaque volume with PCD CT UHR (325.4 mm3) in contrast to EID CT (627.7 mm3).
“Compared with energy-integrating detector CT, ultrahigh-spatial-resolution (UHR) photon-counting detector (PCD) CT reduces coronary plaque volume by approximately one-third, with the most pronounced differences in fibrotic components,” wrote lead study author Milan Vecsey-Nagy, M.D., who is affiliated with the Department of Radiology and Radiological Science at the Medical University of South Carolina in Charleston, S.C., and colleagues.
The researchers also pointed out significant differences in intra-reader and inter-reader agreements for PCD CT UHR and EID CT with respect to low-attenuation plaque (LAP) volume.
Intra-reader agreement for LAP volume with PCD CT UHR was 22 percent higher than that for EID CT (84 percent interclass correlation coefficient (ICC) of 84 percent vs. 62 percent). The study authors found a 45 percent difference in inter-reader agreement for LAP volume between PCD CT UHR (ICC of 92 percent) vs. EID CT (ICC of 47 percent).
Three Key Takeaways
1. Enhanced coronary plaque characterization. Ultra-high-resolution photon-counting detector (PCD) CT provides significantly improved quantification of coronary plaque compared to conventional energy-integrating detector (EID) CT, with an approximate one-third reduction in total plaque volume.
2. Superior assessment of fibrotic and low-attenuation plaques. PCD CT UHR demonstrated a more pronounced reduction in fibrotic plaque volume (49 percent lower than EID CT) and exhibited higher intra-reader (22 percent improvement) and inter-reader (45 percent improvement) agreement in measuring low-attenuation plaque (LAP) volume, suggesting enhanced reproducibility and reliability for cardiovascular risk assessment.
3. Potential for more precise longitudinal monitoring. Due to its strong agreement in repeated measurements and between different readers, PCD CT UHR may provide a more robust and repeatable method for tracking subtle changes in cardiovascular disease, making it a valuable tool for long-term patient monitoring.
“Our results showed strong agreement for LAP volume between repeated measurements and readers for PCD CT, indicating that UHR could provide a repeatable and robust method of quantifying cardiovascular risk, with important implications for longitudinal studies that require precise measurements to detect subtle changes,” said Vecsey-Nagy and colleagues.
While noting comparable assessments of calcified plaque volume with PCD CT UHR and EIDCT, the researchers noted that subsequent analysis of 42 predominantly calcified plaques revealed lower calcification volumes with PCD CT UHR (194.2 mm3 vs. 218.2 mm3).
(Editor’s note: For related content, see “Can Quantum Iterative Reconstruction Reinvent Photon-Counting CT Technology?,” “Siemens Healthineers Debuts New Photon-Counting CT Systems at RSNA” and “Photon-Counting CTA for Patients with PAD: What the Research Reveals About Assessment for Stenotic Lesions.”)
In regard to study limitations, the authors noted a small, predominantly White cohort with a high burden of coronary disease, which may have exaggerated differences between PCD CT and EID CT. The researchers conceded that low numbers of non-calcified lesions and a low extent of LAP volume are additional factors that may have impacted the study results.
