Related Experiment Video
Updated: Nov 14, 2025
Ultrasound Imaging of the Thoracic and Abdominal Aorta in Mice to Determine Aneurysm Dimensions
Published on: March 8, 2019
Aortic root measurement on CT: linear dimensions, aortic root area and comparison with echocardiography. A
Kai'En Leong1, Henry Knipe2,3, Simon Binny1,2
1Department of Cardiology, The Royal Melbourne Hospital, Parkville, Australia.
Insights
Computed tomography (CT) and transthoracic echocardiography (TTE) show systematic differences in aortic root measurements. CT short axis measurements are reproducible and correlate well with aortic root area, but the specific CT plane is crucial for accurate comparisons.
Area of Science:
- Cardiovascular Imaging
- Radiology
- Cardiac Anatomy
Background:
- Accurate aortic root measurement is vital for diagnosing and monitoring cardiovascular conditions.
- Transthoracic echocardiography (TTE) is a standard imaging modality, but computed tomography (CT) offers detailed anatomical visualization.
- Discrepancies between CT and TTE measurements can complicate clinical decision-making.
Purpose of the Study:
- To compare various CT aortic root measurement planes against TTE.
- To assess the reproducibility and correlation of CT measurements with aortic root area.
Main Methods:
- Retrospective review of ECG-gated CT and TTE images from 70 patients with tricuspid aortic roots.
- Measurement of nine linear dimensions across three CT planes (coronal, short axis, three-chamber).
- Standard TTE measurements from the parasternal long axis view.
Main Results:
- CT short axis measurements demonstrated excellent reproducibility (ICC 0.96-0.99).
- CT coronal and short axis maximal dimensions were larger than TTE (mean difference 2 mm, p < 0.001).
- CT cusp-to-commissure measurements were smaller than TTE (mean difference 2 mm, p < 0.001).
- All CT short axis measurements correlated well with aortic root area (Pearson's R 0.97 for maximal dimension).
Conclusions:
- Systematic differences exist between CT and TTE aortic root dimensions, varying by CT measurement plane.
- CT short axis measurements are reproducible and correlate well with aortic root area.
- Specifying the CT plane and dimension is essential for consistent interpretation and comparison.
Objective:
We sought to assess the different CT aortic root measurements and determine their relationship to transthoracic echocardiography (TTE).
Methods:
TTE and ECG-gated CT images were reviewed from 70 consecutive patients (mean age 54 ± 18 years; 67% male) with tricuspid aortic roots (trileaflet aortic valves) between Nov 2009 and Dec 2013. Three CT planes (coronal, short axis en face and three-chamber) were used for measurement of nine linear dimensions. TTE aortic root dimension was measured as per guidelines from the parasternal long axis view.
Results:
All CT short axis measurements of the aortic root had excellent reproducibility (intraclass correlation coefficient, ICC 0.96-0.99), while coronal and three-chamber planes had lower reproducibility with ICC 0.90 (95% CI 0.84-0.94) and ICC 0.92 (0.87-0.95) respectively. CT coronal and short axis maximal dimensions were systematically larger than TTE (mean 2 mm larger, p < 0.001), while CT cusp to commissure measurements were systematically smaller (CT RCC-comm mean 2 mm smaller than TTE, p < 0.001). All CT short axis measurements had excellent correlation with aortic root area with CT short axis maximal dimension marginally better than the rest (Pearson's R 0.97).
Conclusion:
Systematic differences exist between CT and TTE dependent on the CT plane of measurement. All CT short axis measurements of the aortic root had excellent reproducibility and correlation with aortic root area with maximal dimension appearing marginally better than the rest. Our findings highlight the importance of specifying the chosen plane of aortic root measurement on CT.
Advances In Knowledge:
Systematic differences in aortic root dimension exist between TTE and the various CT measurement planes. CT coronal and short axis maximal dimensions were systematically larger than TTE, while CT cusp to commissure measurements were smaller. CT readers should indicate the plane of measurement and the specific linear dimension to avoid ambiguity in follow-up and comparison.
Related Concept Videos
01:22Aortic Regurgitation II: Clinical Features and Diagnostic Tests
01:21Aneurysm II: Clinical Manifestations and Diagnostic Studies