High-definition computed tomography for coronary artery stent imaging: a phantom study.

Area of Science:

• Medical Imaging
• Cardiovascular CT
• Radiology

Background:

• Accurate imaging of small caliber coronary stents (≤ 3 mm) is crucial for cardiovascular assessment.
• Conventional 64-row standard-definition CT (SDCT) may have limitations in visualizing fine stent details.
• High-definition CT (HDCT) offers potential improvements in image resolution and accuracy.

Purpose of the Study:

• To evaluate the performance of HDCT in imaging small coronary stents (≤ 3 mm).
• To compare HDCT scan modes against conventional SDCT.
• To assess image quality metrics including lumen narrowing and attenuation values.

Main Methods:

• A cardiac phantom with 2.5 mm and 3.0 mm coronary stents was scanned using HDCT and SDCT.
• Scan modes included retrospective ECG-gated helical and prospective ECG-triggered axial acquisitions at 120 kVp and 100 kVp.
• Measurements of inner stent diameter (ISD), in-stent attenuation (AV(in-stent)), and in-vessel attenuation (AV(in-vessel)) were performed, calculating artificial lumen narrowing (ALN) and artificial attenuation increase (AAI).

Main Results:

• HDCT demonstrated statistically lower ALN (30% vs 35%) and AAI (15.7 HU vs 71.4 HU) compared to SDCT, indicating improved accuracy.
• Prospective axial scanning resulted in smaller ALN than retrospective helical scanning on both HDCT and SDCT.
• No significant difference in ALN was observed between 120 kVp and 100 kVp tube voltages on HDCT.

Conclusions:

• HDCT significantly enhances measurement accuracy for imaging small coronary stents compared to SDCT.
• The prospective ECG-triggered axial technique with HDCT is advantageous for evaluating small coronary stents.
• Utilizing 100 kVp with HDCT offers a lower radiation dose option while maintaining diagnostic performance for small caliber stents.