Photon-Counting CT Study Examines Impact of Scan Mode on Radiation Dosing for CCTA in Patients with Non-Acute Chest Pain

For patients with non-acute chest pain and suspected coronary artery disease (CAD), emerging research suggests that scan mode selection with photon-counting computed tomography (PCCT) may significantly reduce radiation exposure for those undergoing coronary CT angiography (CCTA).

For the study, presented at the Society of Cardiovascular Computed Tomography (SCCT) conference, researchers reviewed CCTA data for 1,000 patients (mean age of 60.3) with non-acute chest pain who were suspected of having CAD. The study authors noted that 83 percent of the cohort had a heart rate of < 65 beats/minute with a mean heart rate of 58 beats/minute.

For 164 patients in the cohort, CCTA images were in obtained with the flash mode on a dual-source PCCT system (Naeotom Alpha, Siemens Healthineers) at a dose length product (DLP) of 135 mGy*cm. The sequential scan mode was utilized for 561 patients at a DLP of 161 mGy*cm and 276 patients had spiral scan mode acquisition at a DLP of 407 mGy*cm, according to the researchers.

For patients with non-acute chest pain who undergo coronary computed tomography angiography (CCTA), research presented at the Society of Cardiovascular Computed Tomography (SCCT) conference suggests that utilizing dual-source photon-counting CT “provides a very high rate of unimpaired diagnostic image quality at low radiation exposure.” (Image courtesy of Adobe Stock.)

At a mean DLP of 225 mGy*cm, the study authors found a 99.7 percent rate of full evaluability for coronary artery assessment across all scan mode acquisitions with PCCT.

“Coronary CT angiography with a dual source photon counting system provides a very high rate of unimpaired diagnostic image quality at low radiation exposure. Radiation exposure is significantly dependent on the chosen data acquisition mode,” noted lead study author Tara Zuhair Kassem, M.D., who is affiliated with University Hospital Erlangen in Erlangen, Germany, and colleagues.

The researchers added that heart rate was a statistically significant prognostic factor in predicting radiation exposure in the cohort.

“Through its influence on acquisition parameters, heart rate is the most important predictor of radiation exposure,” emphasized Kassem and colleagues.

(Editor’s note: For related content, see “Study: Photon-Counting CT Reduces Radiation Dosing by More than 40 Percent in Kids with Congenital Heart Disease,” “Photon-Counting Computed Tomography: Eleven Takeaways from a New Literature Review” and “New Analysis Forecasts Substantial Cost Savings with the Use of Photon Counting CT for CCTA.”)

Reference

1. Kassem TZ, Marwan M, Jung S, Achenbach S. CTA in on-acute chest pain predictors of radiation exposure and image quality in coronary CT angiography on dual source photon counting system. Presented at the Society of Cardiovascular Computed Tomography (SCCT) conference, July 17-20, 2025, Montreal, Canada. Available at: https://scct.org/page/SCCT2025abstractpdfs_ . Accessed July 18, 2025.