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Updated: Jun 10, 2026
Four-Dimensional Computed Tomography-Guided Valve Sizing for Transcatheter Pulmonary Valve Replacement
Published on: January 20, 2022
Four-dimensional computed tomography: a method of assessing right ventricular outflow tract and pulmonary artery
Silvia Schievano1, Claudio Capelli, Carol Young
1Cardiovascular Unit, UCL Institute of Child Health & Great Ormond Street Hospital for Children, Great Ormond Street, London, WC1N 3JH, UK. s.schievano@ich.ucl.ac.uk
Insights
Four-dimensional CT (4DCT) reveals significant 3D RVOT/PA deformations and errors in 2D assessments, crucial for developing new pulmonary valve interventions.
Area of Science:
- Cardiovascular Imaging
- Medical Physics
- Congenital Heart Disease Research
Background:
- Right ventricular outflow tract (RVOT) and pulmonary artery (PA) morphology and dynamics are critical after congenital heart disease repair.
- Conventional 2D assessments may not fully capture complex 3D cardiac motion.
Purpose of the Study:
- To characterize 3D deformations of the RVOT/PAs throughout the cardiac cycle.
- To quantify the errors associated with conventional 2D assessments compared to 3D analysis.
Main Methods:
- Retrospective analysis of 12 patients using contrast-enhanced, ECG-gated cardiovascular CT.
- Creation of four-dimensional CT (4DCT) datasets from 10 cardiac phases.
- Measurement of RVOT/PA deformation in space and time using static and dynamic section planes.
Main Results:
- 4DCT successfully characterized in vivo 3D RVOT/PA changes during the cardiac cycle.
- Significant variability in RVOT/PA morphology and dynamics was observed, particularly post-surgical repair.
- Substantial differences (up to 150%) in cross-sectional area measurements were found between static and dynamic planes due to 3D displacements.
Conclusions:
- 4DCT imaging highlights significant RVOT/PA dynamic variability and potential for measurement errors with 2D methods.
- Accurate 3D analysis is essential for reliable deformation measurements.
- Findings support the development of percutaneous pulmonary valve interventions.
Objective:
To characterise 3D deformations of the right ventricular outflow tract (RVOT)/pulmonary arteries (PAs) during the cardiac cycle and estimate the errors of conventional 2D assessments.
Methods:
Contrast-enhanced, ECG-gated cardiovascular computed tomography (CT) findings were retrospectively analysed from 12 patients. The acquisition of 3D images over 10 phases of the cardiac cycle created a four-dimensional CT (4DCT) dataset. The datasets were reconstructed and deformation measured at various levels of the RVOT/PAs in both space and time. Section planes were either static or dynamic relative to the motion of the structures.
Results:
4DCT enabled measurement and characterisation of in vivo 3D changes of patients' RVOT/PA during the cardiac cycle. The studied patient population showed a wide range of RVOT/PA morphologies, sizes and dynamics that develop late after surgical repair of congenital heart disease. There were also significant differences in the measured cross-sectional areas of the structures between static and dynamic section planes (up to 150%, p<0.05) secondary to large 3D displacements and rotations.
Conclusions:
4DCT imaging data suggest high variability in RVOT/PA dynamics and significant errors in deformation measurements if 3D analysis is not carried out. These findings play an important role for the development of novel percutaneous approaches to pulmonary valve intervention.
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