Assessing coronary in-stent restenosis using ultrahigh-resolution photon-counting detector CT: results from a...

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.