Clinical Impact of Cardiac Photon-Counting Detector CT

Comprehensive Characterization of Coronary Atherosclerotic Disease Using Photon-counting Detector Dual-source CT and Its Impact on Patient Management

The purpose of this research trial is to determine whether images taken using a Photon Counting Detector CT scanner (PCD-CT) provide clinically important information about the severity of suspected coronary artery disease and perfusion defects compared to traditional Energy Integrating Detector CT (EID-CT) and nuclear medicine cardiac stress tests.

Study Overview

• Status: Completed
• Conditions: Coronary Artery Disease
• Intervention / Treatment: Diagnostic test: Photon-counting detector computed tomography (PCD-CT)

Detailed Description

This study will focus on demonstrating the benefits of PCD-CT for clinical indications and findings where the improved spatial and temporal resolution, decreased quantum and electronic noise, improved spectral imaging capabilities, and increased iodine signal are expected to benefit the diagnosis and characterization of CAD and myocardial perfusion defects.

• Study Type: Interventional
• Enrollment (Actual): 276
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 99 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients referred for coronary artery cardiac CT imaging or nuclear medicine or MRI cardiac perfusion within the Department of Radiology or Cardiology.
• Patients who are able and willing to sign the informed consent will be enrolled
• Negative pregnancy test if subject is of child-bearing age (females of child-bearing potential will be screened for pregnancy using a urine pregnancy test, which will be administered by the unit study coordinator at no cost to the patient).

Exclusion Criteria:

• Patients unable to provide written informed consent
• Pregnancy
• eGFR ≤ 30
• History of prior moderate or severe contrast reaction includes: unresponsiveness, severe respiratory distress, convulsions, arrhythmia, cardiopulmonary distress, progressive angioedema, laryngeal edema, dyspnea, bronchospasm, symptomatic tachycardia, symptomatic bradycardia, hypotension, hypertensive crisis.
• Any history of required premedication prior to iodinated contrast administration.
• Patients that consent to participation but do not undergo their clinically-indicated, contrast-enhanced CT, or nuclear medicine or MR perfusion scanning for any reason (e.g., bad IV, infiltration, reaction, change in indication).
• Patients experiencing atrial fibrillation, premature ventricular contractions or other heart rhythm abnormalities
• Hospitalized patients or patients under care in the Emergency Department

Specific exclusion criteria only for participation in the cardiac stress test arm of this study (requiring administration of Regadenoson):

• Anything by mouth within three hours of the examination
• Known hypersensitivity to Regadenoson, Adenosine, or Dipyridamole.
• Active ongoing wheezing or poorly controlled asthma or COPD (hospitalized within last month or receiving treatment for flair within last month).
• Second (type I or II) or third degree atrioventricular (AV) block or sinus node dysfunction unless patient has functioning artificial pacemaker.
• Ingested greater than 4 oz. of caffeine within the last 12 hours.
• Currently experiencing unstable coronary syndrome.
• Uncontrollable seizures within the last 3 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Clinical Coronary CTA Cohort; Subjects scheduled for a clinically indicated coronary CT angiogram will receive a research contrast-enhanced coronary CT angiogram using photon-counting detector CT.	Diagnostic test: Photon-counting detector computed tomography (PCD-CT); Cardiac CT imaging will be performed using a newly developed CT scanner that uses photon-counting detectors and the results compared to those from conventional CT, MRI, or nuclear medicine imaging systems
Experimental: Clinical Nuclear Medicine or MRI Cardiac Stress Test Cohort; Subjects scheduled for a clinically indicated nuclear medicine or MRI cardiac stress test will receive a research contrast-enhanced coronary CT angiogram using photon-counting detector CT at rest and after administration of a cardiac stress agent.	Diagnostic test: Photon-counting detector computed tomography (PCD-CT); Cardiac CT imaging will be performed using a newly developed CT scanner that uses photon-counting detectors and the results compared to those from conventional CT, MRI, or nuclear medicine imaging systems

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Arm 1: Change in Clinical Coronary Artery Disease Status Measured in Photon-counting Detector CT Relative to Clinical CT as Measured by Percent Area Stenosis	Percent area stenosis (PAS) measures coronary artery stenosis (blockage) and is defined as the vessel's cross-sectional area in the region of highest stenosis (i.e., most closed) divided by the healthy vessel's cross-sectional area. PAS can range from 0% to 100% with higher percentages indicating worse stenosis. In arm 1, PAS was measured at the site of worst stenosis in each coronary vessel or patient using validated commercial software. For each stenosis, PAS was measured at the same location in the photon-counting detector CT (PCD-CT) angiography scan and in the clinical CT angiography scan (EID-CT). These values were subtracted to get a change in PAS between the clinical EID-CT scan and the PCD-CT scan for each stenosis. Change in PAS impacts patient management. During recruitment, the PCD-CT scanner had a multi-energy ultra-high resolution update allowing a new scan mode that collected x-ray energy data. This mode was used for all patients recruited after the update.	Through completion of CT exam, approximately 1 hour
Arm 2: Reader Sensitivity and Specificity to Myocardial Perfusion Defects Imaged by Photon-counting Detector CT at Rest	Sensitivity was calculated as the number of patients correctly identified by the reader as having perfusion defects on photon-counting detector (PCD) CT divided by the total number of patients with perfusion defects. Specificity was calculated as the number of patients correctly identified by the reader as not having perfusion defects on PCD-CT divided by the total number of patients without perfusion defects. Sensitivity and specificity can range between 0 and 100%. All analyzed images were taken when the patient was at rest.	Through completion of CT exam, approximately 1 hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Arm 1: Number of Participants With Decrease in Coronary Artery Disease-Reporting and Data System (CADRADS) Score	Coronary Artery Disease-Reporting and Data System (CADRADS) score is a value assigned to each patient based on the patient's highest percent diameter stenosis (PDS) with higher scores indicating worse stenosis. PDS is defined as the diameter of the stenosed (blocked) coronary vessel divided by the diameter of the healthy vessel. A CADRADs score of 0-5 is assigned to the following PDS values, respectively: 0%, 1-24%, 25-49%, 50-70%, 70-99%, and 100%. A CADRAD score was calculated for each patient in both EID-CT and PCD-CT scans based on the respective PDS for the same lesion. The number of patients whose CADRADS decreased in PCD-CT relative to EID-CT (e.g. 2 on PCD-CT, 3 on EID-CT) is reported below. Change in CADRADS impacts patient management. During recruitment, the PCD-CT scanner had a multi-energy ultra-high resolution update allowing a new scan mode that collected x-ray energy data. This mode was used for all patients recruited after the update.	Through completion of CT exam, approximately 1 hour
Arm 2: Reader Sensitivity and Specificity to Myocardial Perfusion Defects Imaged by Photon-counting CT During Cardiac Stress	Sensitivity was calculated as the number of patients correctly identified by the reader as having perfusion defects on photon-counting detector CT (PCD-CT) divided by the total number of patients with perfusion defects. Specificity was calculated as the number of patients correctly identified by the reader as not having perfusion defects on PCD-CT divided by the total number of patients without perfusion defects. Sensitivity and specificity can range between 0 and 100%. All analyzed images were taken after the patient was administered a pharmacological cardiac stress agent to increase heart rate.	Through completion of CT exam, approximately 1 hour

Collaborators and Investigators

• Sponsor: Mayo Clinic
• Collaborators: National Institute for Biomedical Imaging and Bioengineering (NIBIB)
• Investigators: Principal Investigator: Cynthia McCollough, PhD, Mayo Clinic

Publications and helpful links

Helpful Links

• Mayo Clinic Clinical Trials

Study record dates

Study Major Dates

• Study Start (Actual): August 24, 2022
• Primary Completion (Actual): February 19, 2026
• Study Completion (Actual): March 19, 2026

Study Registration Dates

• First Submitted: January 14, 2022
• First Submitted That Met QC Criteria: February 4, 2022
• First Posted (Actual): February 15, 2022

Study Record Updates

• Last Update Posted (Actual): June 12, 2026
• Last Update Submitted That Met QC Criteria: June 10, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Cardiac CT; Photon Counting CT; Coronary CT Angiography; Cardiac Stress Imaging
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Heart Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Coronary Disease; Myocardial Ischemia; Coronary Artery Disease
• Other Study ID Numbers: 21-004933; R01EB028590 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No