Photon-Counting Detector CT Angiography Versus Digital Subtraction Angiography in Patients with Peripheral Arterial...

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Peripheral arterial occlusive disease (PAOD) significantly impacts patient mobility and quality of life.
• Accurate imaging is crucial for diagnosing and managing PAOD, guiding treatment decisions.
• Photon-counting detector CT angiography (PCD-CTA) offers potential advancements in vascular imaging.

Purpose of the Study:

• To compare the diagnostic confidence of PCD-CTA using different vascular reformatting kernels against digital subtraction angiography (DSA) in patients with PAOD.
• To evaluate the impact of various kernels on image quality metrics and diagnostic performance in lower extremity CTA.
• To determine the optimal kernel for assessing stenosis and calcifications in PAOD.

Main Methods:

• Retrospective analysis of 45 lower extremity PCD-CTA examinations in 39 patients with PAOD.
• Post-processing of CTA data using three vascular kernels (Bv36, Bv48, Bv56).
• Objective (attenuation, noise, CNR, SNR) and subjective (calcium blooming, sharpness, noise) image quality assessments by three radiologists.
• Comparison of diagnostic performance and concordance with DSA as the reference standard.

Main Results:

• Luminal attenuation was consistent across kernels; however, sharper kernels increased image noise while decreasing SNR and CNR.
• The sharp Bv56 kernel subjectively reduced calcium blooming and improved vessel sharpness.
• Sensitivity for stenosis quantification was comparable across kernels, but specificity increased with sharper kernels, particularly in severely calcified tibial vessels.
• Diagnostic confidence was highest with the Bv56 kernel, showing improved concordance with DSA.

Conclusions:

• Sharp convolution kernels in lower leg PCD-CTA enhance diagnostic confidence.
• Improved vessel delineation and reduced calcium blooming with sharper kernels outweigh increased image noise.
• PCD-CTA with appropriate kernel selection, specifically Bv56, provides reliable assessment for PAOD, comparable to DSA.