Dr. Leena Sulaibeekh, Dr. Mary AI-Teraif, Dr. Rajesh Jayakumar, Dr. Mohammed Ali Zayed, Dr. Chetan Narayana, and Dr. Mohammed Faizal
Mohammed Bin Khalifa Bin Salman Al Khalifa Specialist Cardiac Centre (MKCC), Bahrain
June 3, 2026
lntroduction
Cardiovascular care and imaging requirements have undergone a significant transformation in recent years. Advanced diagnostic imaging must rise to meet the increasing complexity of patient needs, ensuring precise, tailored diagnostics and improved clinical outcomes. The introduction of dual-source photoncounting CT systems has marked a revolutionary step in cardiac imaging. These systems utilize native temporal resolution and sub-second scanning, enabled by their unparalleled rotational speed and high-pitch capabilities.
This state-of-the-art technology delivers exceptional image clarity, even in the most challenging clinical scenarios, and has opened new avenues for cardiac imaging.
In this article, we aim to highlight the impact of this technology by presenting 10 cases performed du ring the early days of the photon-counting detector (PCD) system implementation in our department. These cases underscore the potential of PCD systems to enhance diagnostic accuracy and optimize patient care.
Ultra-High-Resolution Cardiac CT lmaging with Photon-Counting CT Technology
The advent of Ultra-High-Resolution (UHR) photon-counting CT (PCD-CT) technology is revolutionizing cardiac imaging, providing unmatched clarity and enhanced diagnostic capabilities. With the ability to deliver images at 0.2 mm and 0.4 mm slice thickness, UHR PCD-CT enables visualization of minute anatomical details of the heart and vessels that were previously undetectable. This groundbreaking advancement is setting a new benchmark in cardiovascular diagnostics, paving the way for more precise and tailored patient care. In this article, we discuss the early experiences and findings from the initial days of PCD-CT implementation in our department.
Advantages in Highly Calcified Vessels
One of the key challenges in cardiac imaging has been the accurate evaluation of heavily calcified vessels. Calcifications often obscure the visualization of vascular structures and impede precise disease quantification, leading to diagnostic uncertainty. UHR PCD-CT overcomes this limitation by delivering exceptional spatial resolution and significantly reducing blooming artifacts. This advanced technology enables accurate assessment of coronary stenosis, even in cases with severe calcification, allowing clinicians to distinguish between calcified plaque and true vessel lumen. By improving diagnostic confidence and facilitating more precise treatment planning, UHR PCD-CT represents a major advancement in the management of patients with complex coronary artery disease.
Enhanced Stent Evaluation
Stent assessment is another area where UHR PCD-CT demonstrates significant advantages. lts advanced resolution capabilities overcome the limitations of conventional CT in visualizing stent struts and accurately detecting in-stent restenosis. This enhanced imaging quality ensures more reliable follow-up evaluations, enabling clinicians to make better-informed decisions for patients with prior stent placement, ultimately improving patient outcomes.
Pre- and Post-Cardiac Prosthesis Evaluation
Ultra-High-Resolution UHR PCD-CT has proven invaluable for both pre- and post-procedural evaluation of cardiac prostheses. lts ability to capture intricate anatomical details facilitates meticulous planning of interventions, ensures the accurate placement of prosthetic devices, and enables thorough monitoring of their performance post-implantation. This advanced imaging technology significantly enhances procedural outcomes and long-term patient care.
lmproved Coronary Stenosis Quantification Accuracy
Compared to conventional energy-integrating detector (EID) CT systems, Ultra-UHR PCD-CT offers a significant improvement in the quantification of coronary stenosis, particularly in plaques with calcified components. This enhanced capability leads to more accurate disease assessment and allows clinicians to develop more targeted and effective treatment plans.
High Diagnostic Accuracy in CAD Detection
UHR PCD-CT Angiography has demonstrated exceptional diagnostic accuracy in detecting coronary artery disease (CAD), even in high-risk populations. lts ability to assess patients with severe coronary calcification or prior stent placement makes it an indispensable tool in modern cardiology, enhancing both diagnostic precision and treatment planning.
Methods: Scan Technique
Patients were scanned using the NAEOTOM Alpha® CT scanner. This advanced imaging platform features a state-of-the-art Al-powered cardiac imaging package. The illustrated cases were performed with UHR PCD-CT protocols that facilitate slice thicknesses of 0.2 mm and 0.4 mm with the possibility of high-sharp kernel reconstructions. Protocols were adapted according to the patient's heart rate and included:
- Adaptive Perspective Acquisition (CorAdSeq)
- Adaptive Retrospective Acquisition
- Prospective ECG-Triggered Sequences (0.2 mm and 0.4 mm)
These protocols, combined with Al-driven algorithms and dualsource CT (DSCT) technology, ensure optimal image quality with the lowest achievable radiation dose. The automatic exposure control for kV and mAs further minimizes patient-specific dose requirements, enhancing both safety and efficiency.
Ultra-High-Resolution imaging using PCD technology
UHR reconstruction is a key advantage of the PCD detector. Due to the small pixel size mentioned earlier, current PCD-CT scanners achieve superior in-plane and longitudinal spatial resolution compared to conventional clinical energy-integrating detector (EID) CT systems, with resolutions as fine as 150 µm. This enhanced resolution facilitates the evaluation of in-stents and the imaging of heavily calcified vessel lumen structures.
Clinical Case Studies
Multi-ln-Stent Evaluation - Proximal and Distal
Figure 1. Coronary CT Imaging of the Left Anterior Descending (LAD) Artery and Branches for In-Stent Patency Evaluation Using an Ultra-High-Resolution Photon-Counting CT Protocol: Coronary CT imaging of the left anterior descending (LAD) artery and its branches for in-stent patency evaluation was performed using a photon-counting CT (Ultra-High-Resolution protocol. Reconstructions included consecutive slice thicknesses with tailored kernel applications: 0.2 mm with an ultra-sharp kernel, 0.4 mm with a sharp kernel, and 0.6 mm with a soft kernel. Optimized windowing further enhanced the visualization of the stent lumen and adjacent structures, highlighting the protocol’s advanced diagnostic capabilities.
Figure 2. Coronary CT Imaging for In-Stent Patency Evaluation: Coronary CT imaging using an Ultra-High-Resolution (UHR) photon-counting CT protocol with adaptive sequence acquisition offers significant dose reduction while ensuring excellent image clarity. Images were reconstructed at 0.2 mm, 0.4 mm, and 0.6 mm slice thicknesses. Key technical details include protocol CTDIvol of 5.43 mGy, 192 mAs exposure, and 90 kVp tube voltage. A contrast protocol of 60 mL was administered at a flow rate of 6 mL/s. Multi-kernel reconstructions enhanced the evaluation of in-stent patency, with Spider views and ciné VRT images of stents in the left anterior descending artery (LAD), LAD to obtuse marginal branch 1 (OM1), and right coronary artery (RCA). These high-resolution images allowed confident assessment without artifacts or diagnostic ambiguity.
Figure 3. Coronary CT Imaging of the Left Anterior Descending (LAD) Artery and Branches for In-Stent Patency Evaluation Using an Ultra-High-Resolution Photon-Counting CT Protocol: Coronary CT imaging of the left anterior descending (LAD) artery and its branches for in-stent patency evaluation was performed using a photon-counting CT (Ultra-High-Resolution protocol. Reconstructions included consecutive slice thicknesses with tailored kernel applications: 0.2 mm with an ultra-sharp kernel, 0.4 mm with a sharp kernel, and 0.6 mm with a soft kernel. Optimized windowing further enhanced the visualization of the stent lumen and adjacent structures, highlighting the protocol’s advanced diagnostic capabilities.
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LAD - UHR 0.2mm | LAD - UHR 0.2 mm | RCA - UHR 0.2mm |
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CINI VRT Spider view with sharp kernel | RCA - UHR 0.2 mm | RCA - UHR 0.2 mm |
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RCA - VRT | LAD - second stent VRT | |
Images: Courtesy of Mohammed Bin Khalifa Bin Salman Al Khalifa Specialist Cardiac Centre (MKCC), Bahrain
