Silicon-based Photon Counting Computed Tomography for Advanced Cardiac Imaging

NCT07411196 | Not Yet Recruiting

• 1 other identifier: SILIC-HEART
• Study Type: interventional
• Target: 1,000
• Locations: 0 countries
• Sites: N/A

Brief Summary

Computed tomography (CT) is a key imaging modality, with rapidly increasing use in cardiovascular diagnostics. Coronary CT angiography (CCTA) provides high-resolution, non-invasive assessment of coronary anatomy and is now recommended as a first-line test for suspected coronary artery disease (CAD) due to its excellent sensitivity, allowing for the firm exclusion of the disease. CCTA, accompanied by coronary artery calcium (CAC) scanning have become, therefore, recommended as the first-line diagnostic modalities in a majority of patients with suspected CAD. It is thanks to the steady efforts to improve this modality's diagnostic performance further and reduce patients' exposure to radiation and contrast agents that have contributed to the successful implementation of this modality in routine clinical practice. However, further progress with conventional energy-integrating detector (EID) CT is limited by detector physics, as EIDs measure only total deposited x-ray energy. By contrast, photon-counting CT (PCCT) introduces semiconductor detectors that register individual photons and their energies, enabling higher spatial resolution, improved contrast-to-noise, and intrinsic spectral imaging. Early PCCT systems have shown better visualization of small coronary structures and reduced blooming, though limitations such as degraded energy resolution at high speeds and cross-talk still restrict full spectral performance. Radiation dose reductions are possible but have not yet been consistently achieved compared with optimized EID-CCTA, which is critical if PCCT is to be used for risk stratification or screening. There remains a need to better exploit PCCT's spectral capabilities for plaque and stent evaluation while maintaining acceptable radiation and contrast exposure. By 2026, second-generation silicon-based scanners (Si-PCCT) are approaching, offering potential improvements over first-generation cadmium-telluride systems. The present study aims to evaluate the diagnostic performance of such devices and exploit their technical advantages to lower radiation dose.

Conditions

Coronary Artery Disease

Keywords

coronary artery disease; photon-counting computed tomography; coronary computed tomography angiography

Outcome Measures

Primary Outcomes (1)

• Image quality of standard and low-dose Si-PCCT CCTA acquisition protocols versus the standard-of-care EID-CT CCTA protocol.

  Proportion of patients with ≥95% interpretable coronary segments achieved with standard and low-dose Si-PCCT protocols vs. the reference protocols.

  Same day as enrollment

Study Arms (1)

Patients underdoing clinically indicated coronary CT angiography

OTHER

All participants will undergo both clinically indicated coronary CT on a conventional CT scanner plus additional coronary CT on the photon-counting CT scanner

Device: Photon-counting computed tomography

Interventions

Photon-counting computed tomography DEVICE

Device is a novel second generation photon-counting CT device with silicon-based detectors

Patients underdoing clinically indicated coronary CT angiography

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Referred for clinically indicated cardiac CT
• Age ≥18 years
• Informed Consent signed by the subject

You may not qualify if:

• Known allergy to iodinated contrast
• Pregnancy
• Impaired renal function (eGFR\<30ml/min/1.73m2)
• Any other common contraindication for routine cardiac CT or any other reason leading to the inability to successfully and completely perform routine cardiac CT with and without contrast-enhancement

Sponsors & Collaborators

• Ronny R Buechel, MD: lead

MeSH Terms

Conditions

Coronary Artery Disease

Condition Hierarchy (Ancestors)

Coronary Disease; Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Vascular Diseases

Central Study Contacts

Ronny R Buechel, MD

CONTACT

+41442551059; ronny.buechel@usz.ch

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Deputy Director of the Department of Nuclear Medicine

Model Details: Photon-counting computed tomography device with silicon-based detectors

Study Record Dates

• First Submitted: February 3, 2026
• First Posted: February 13, 2026
• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): January 31, 2029
• Study Completion (Estimated): January 31, 2029
• Last Updated: February 13, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share