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Updated: Mar 20, 2026
Imaging In-Stent Restenosis: An Inexpensive, Reliable, and Rapid Preclinical Model
Published on: September 14, 2009
Assessing coronary in-stent restenosis using ultrahigh-resolution photon-counting detector CT: results from a
Bálint Szilveszter1, Muhammad Taha Hagar2, Péter Kulyassa1
1Semmelweis University Heart and Vascular Center, Városmajor Street 68., 1122 Budapest, Hungary.
Insights
Ultrahigh-resolution (UHR) photon-counting detector (PCD)-CT significantly improves the detection of coronary in-stent restenosis (ISR), including non-obstructive and small-caliber stents. This advanced CT technology offers superior diagnostic accuracy compared to standard-resolution imaging.
Area of Science:
- Cardiovascular Imaging
- Medical Physics
- Radiology
Background:
- Coronary in-stent restenosis (ISR) is a significant complication after percutaneous coronary intervention.
- Accurate detection of both obstructive and non-obstructive ISR is crucial for patient management.
- Current CT angiography (CCTA) methods may have limitations in visualizing subtle ISR, especially in small stents.
Purpose of the Study:
- To evaluate the diagnostic accuracy of ultrahigh-resolution (UHR) photon-counting detector (PCD)-CT for detecting coronary ISR.
- To compare UHR PCD-CT performance against invasive coronary angiography (ICA) as the reference standard.
- To assess the utility of UHR PCD-CT in identifying both obstructive and non-obstructive ISR, particularly in small-caliber stents.
Main Methods:
- Retrospective analysis of consecutive patients undergoing CCTA with dual-source PCD-CT.
- UHR scans were reconstructed at 0.2 mm and 0.4 mm slice thickness.
- Diagnostic accuracy for ISR was validated against ICA, with a sub-analysis for stents < 3 mm.
Main Results:
- UHR PCD-CT (0.2 mm) demonstrated higher sensitivity, specificity, and accuracy for detecting non-obstructive ISR compared to standard-resolution (0.4 mm).
- Obstructive ISR detection also showed improved specificity and accuracy with UHR PCD-CT.
- The proportion of evaluable stents increased from 91.5% (0.4 mm) to 99.1% (0.2 mm) with UHR.
- UHR achieved higher accuracy in small-caliber stents (<3 mm) for both non-obstructive and obstructive ISR.
Conclusions:
- UHR PCD-CT offers excellent diagnostic accuracy for detecting coronary ISR.
- This technology significantly improves ISR detection, including non-obstructive and small-caliber stent ISR, compared to standard-resolution reconstructions.
- UHR PCD-CT represents a valuable advancement in non-invasive assessment of coronary stent patency.
Introduction:
To assess the diagnostic accuracy of ultrahigh-resolution (UHR) photon-counting detector (PCD)-CT for detecting obstructive and non-obstructive coronary in-stent restenosis (ISR), using invasive coronary angiography (ICA) as the reference.
Methods:
Consecutive patients with coronary stents who underwent clinically indicated coronary CT angiography (CCTA) on a dual-source PCD-CT were retrospectively identified from two academic centers. All UHR scans were reconstructed at 0.2 mm and 0.4 mm slice thickness, the latter served as an energy-integrating detector CT-like proxy. Series were assessed for the presence of non-obstructive (<50%) and obstructive (≥50%) ISR, with diagnostic accuracy validated against ICA in the overall cohort and in a sub-analysis of stents < 3 mm in diameter.
Results:
Fifty patients (16.0% women; 70.9 ± 10.8 years) with 106 coronary stents were included. ICA identified 17 non-obstructive and 27 obstructive ISR. Non-obstructive ISR was detected in 10 stents on 0.2 mm UHR and 14 on 0.4 mm EID-like standard-resolution reconstructions.Obstructive ISR was described in 26 (0.2 mm) vs. 32 (0.4 mm) stents, respectively. The proportion of evaluable stents increased from 91.5% based on 0.4 mm to 99.1% with 0.2 mm UHR. Compared with standard-resolution images, 0.2-mm UHR improved non-obstructive ISR sensitivity (90.5%vs82.9%), specificity (100.0%vs78.5%), and accuracy (96.2%vs80.2%); and in obstructive ISR, specificity (98.7%vs82.3%), positive predictive value (96.3%vs64.1%), and accuracy (98.1%vs84.9%). Thin-slice UHR achieved higher accuracy in small-caliber stents (<3mm), for both non-obstructive (94.1vs73.5%) and obstructive ISR (94.1%vs79.4%).
Conclusion:
UHR PCD-CT demonstrated excellent diagnostic accuracy and significant improvements in ISR detection compared to the quasi-standard reconstructions, including non-obstructive and small-caliber stent ISR.
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