Objectives Continuous efforts are made to reduce contrast media, improving patient safety, reducing environmental risks, and addressing recurring supply shortages. The aim of this study was to evaluate contrast agent-reduced CT protocols for transcatheter aortic valve reconstruction (TAVR) planning in photon counting detector CT (PCDCT). Materials and methods 162 BMI-matched examinations with standard dose contrast media (SCD; 80 mL; Iohexol 300 mg/mL; 81 examinations) and reduced contrast media dose (RCD; 50 mL; 81 examinations) for TAVR planning on a PCDCT were included in this retrospective monocentric study. Virtual monoenergetic reconstructions (VMI) at 70 keV, 60 keV and 50 keV of contrast agent-reduced examinations were compared with polyenergetic images. Quantitatively, regions-of-interest (ROIs) were placed in the abdominal aorta, iliac bifurcation, femoral artery, left ventricle and trapezius muscles. Signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. Qualitatively, diagnostic quality and contrast were assessed on a visual grading scale of 1 (non-diagnostic) – 5 (excellent) and contrast agent dose was estimated. Results Averaged, SNR and CNR decreased by 8.71% and 16.78%, respectively, on PCDCT with reduced contrast dose (RCD vs. SCD; both p < 0.001). VMI50keV increased SNR by 44.10% (p < 0.001) and CNR by 52.73% (p < 0.001) compared with SCD. In the ascending aorta, SNR increased from 19.80 ± 6.24 (SCD) to 35.78 ± 13.20 (RCDVMI50keV) and CNR from 18.84 ± 7.78 to 29.77 ± 16.70. Median contrast intensity was 5 for SCD, 4 for RCDCR, and 5 for RCDVMI50keV. Conclusion The diagnostic efficacy of TAVR planning assessment using PCDCT with minimized contrast agent dosing is preserved, presenting a practical approach to conserve contrast media. Key Points <Emphasis Type="BoldItalic">Question</Emphasis> The aim of the study was to implement a PCDCT-adapted contrast media dose protocol to reduce contrast agent volume at sufficient diagnostic quality. <Emphasis Type="BoldItalic">Findings</Emphasis> PCDCT enables substantial contrast dose reduction for TAVR planning with maintained diagnostic image quality. Low-keV virtual monoenergetic image reconstructions compensate for the reduced iodine concentration. <Emphasis Type="BoldItalic">Clinical relevance</Emphasis> The study demonstrates the potential of contrast media reduction of PCD-CT in clinical routine. This can benefit patients with renal impairment, for example, and reduce the negative effects of iodinated contrast media on the environment. Graphical Abstract

Photon counting detector CT contrast agent-reduced transcatheter aortic valve reconstruction planning: a comparative study

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2026年5月6日

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Yannik C. Layer,
Alexander Isaak,
Narine Mesropyan,
Patrick A. Kupczyk,
Dmitrij Kravchenko,
Marilia Voigt,
Tatjana Dell,
Julian A. Luetkens,
Daniel Kuetting

摘要

Objectives

Continuous efforts are made to reduce contrast media, improving patient safety, reducing environmental risks, and addressing recurring supply shortages. The aim of this study was to evaluate contrast agent-reduced CT protocols for transcatheter aortic valve reconstruction (TAVR) planning in photon counting detector CT (PCDCT).

Materials and methods

162 BMI-matched examinations with standard dose contrast media (SCD; 80 mL; Iohexol 300 mg/mL; 81 examinations) and reduced contrast media dose (RCD; 50 mL; 81 examinations) for TAVR planning on a PCDCT were included in this retrospective monocentric study. Virtual monoenergetic reconstructions (VMI) at 70 keV, 60 keV and 50 keV of contrast agent-reduced examinations were compared with polyenergetic images. Quantitatively, regions-of-interest (ROIs) were placed in the abdominal aorta, iliac bifurcation, femoral artery, left ventricle and trapezius muscles. Signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. Qualitatively, diagnostic quality and contrast were assessed on a visual grading scale of 1 (non-diagnostic) – 5 (excellent) and contrast agent dose was estimated.

Results

Averaged, SNR and CNR decreased by 8.71% and 16.78%, respectively, on PCDCT with reduced contrast dose (RCD vs. SCD; both p < 0.001). VMI50keV increased SNR by 44.10% (p < 0.001) and CNR by 52.73% (p < 0.001) compared with SCD. In the ascending aorta, SNR increased from 19.80 ± 6.24 (SCD) to 35.78 ± 13.20 (RCD_VMI50keV) and CNR from 18.84 ± 7.78 to 29.77 ± 16.70. Median contrast intensity was 5 for SCD, 4 for RCD_CR, and 5 for RCD_VMI50keV.

Conclusion

The diagnostic efficacy of TAVR planning assessment using PCDCT with minimized contrast agent dosing is preserved, presenting a practical approach to conserve contrast media.

Key Points

Question The aim of the study was to implement a PCDCT-adapted contrast media dose protocol to reduce contrast agent volume at sufficient diagnostic quality.

Findings PCDCT enables substantial contrast dose reduction for TAVR planning with maintained diagnostic image quality. Low-keV virtual monoenergetic image reconstructions compensate for the reduced iodine concentration.

Clinical relevance The study demonstrates the potential of contrast media reduction of PCD-CT in clinical routine. This can benefit patients with renal impairment, for example, and reduce the negative effects of iodinated contrast media on the environment.

Graphical Abstract