Diagnostic performance of the main pulmonary artery-to-ascending aorta diameter ratio for pulmonary hypertension defined by mean pulmonary arterial pressure in children with left-to-right shunt congenital heart disease

Introduction

Pulmonary hypertension (PH) is a severe pediatric hemodynamic syndrome that can progress to right heart failure and death (1). Congenital heart disease (CHD) represents the most prevalent cause (2-4). Left-to-right (L-R) shunt lesions are particularly relevant because long-standing pulmonary overcirculation can contribute to pulmonary vascular remodeling. Right heart catheterization (RHC) remains the reference standard for pressure assessment and hemodynamic classification, although complete assessment also requires variables such as pulmonary vascular resistance and wedge pressure. Its invasive nature limits repeated or broad use in children (5). Imaging findings obtained during clinically indicated examinations may therefore help raise diagnostic confidence if they are interpreted alongside invasive hemodynamic assessment (6).

The main pulmonary artery-to-ascending aorta diameter ratio (MPA/AA) is a readily available computed tomography (CT) marker associated with PH (7-12). In a pediatric cardiac CT study evaluating a broad range of cardiovascular measurements, main pulmonary artery (MPA) diameter and MPA/AA showed the strongest correlations with mean pulmonary arterial pressure (mPAP) (13). Previous pediatric studies have also reported an association between MPA/AA and PH, although their study populations, reference groups, and diagnostic thresholds varied (14-16). In children with L-R shunt CHD, increased pulmonary blood flow may enlarge the pulmonary artery even when mPAP does not meet the definition of PH (17). Reference values from healthy children or heterogeneous disease cohorts may therefore not fit this flow-loaded population.

Therefore, we evaluated the diagnostic performance of CT-derived MPA/AA for mPAP-defined PH in children with L-R shunt CHD, using RHC as the reference standard. We also derived disease-context upper reference limits in children without mPAP-defined PH on RHC. A heterogeneous non-L-R cardiovascular cohort was examined separately to assess model transportability. This work was intended to support interpretation of clinically indicated CT examinations, not to replace RHC or expand CT screening. We present this article in accordance with the STARD reporting checklist (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1-2760/rc).

Methods

Study population

This retrospective study included children who underwent contrast-enhanced CT and diagnostic RHC at the Children’s Hospital of Chongqing Medical University from January 2014 to December 2024. Eligible patients were 3 months to 18 years of age and had a CT-RHC interval of less than 3 months (13,14).

Patients were excluded for any of the following reasons: age younger than 3 months, a CT-RHC interval longer than 3 months, incomplete RHC records, or CT image quality insufficient for vascular measurement. Children were also excluded when anatomical or hemodynamic conditions were unsuitable for MPA/AA interpretation. These conditions included great-vessel, valvular, or pulmonary vascular abnormalities; complex CHD; postoperative altered anatomy/hemodynamics; and other non-target cardiac or mediastinal diseases affecting central vessel anatomy. The screening pathway and major exclusion categories are summarized in Figure 1, and the detailed exclusion subcategories are provided in Table S1. As a retrospective study, we determined the sample size by the number of eligible patients who met the inclusion criteria during the study period.

Figure 1 Flow diagram of patient screening, exclusion, and analytic cohort construction. Of 655 children screened, 424 were excluded according to predefined eligibility, anatomic, hemodynamic-data, and image-quality criteria. Detailed exclusion diagnoses are provided in Table S1. The final analytic cohort included 231 children, including 164 children in the primary left-to-right shunt congenital heart disease cohort for model development and internal validation and 67 children in the non-left-to-right cardiovascular cohort for model transportability assessment. Children without mPAP-defined pulmonary hypertension on right heart catheterization from the overall analytic cohort were used for disease-context upper reference limit estimation. CHD, congenital heart disease; CT, computed tomography; L-R, left-to-right; MPA/AA, main pulmonary artery-to-ascending aorta ratio; mPAP, mean pulmonary arterial pressure; PH, pulmonary hypertension; RHC, right heart catheterization.

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board of Children’s Hospital of Chongqing Medical University (No. 2025120), and individual consent for this retrospective analysis was waived.

RHC-based mPAP definition of PH

RHC was used as the reference standard. The disease status was classified exclusively based on mPAP recorded during RHC. According to updated guidelines, children older than 3 months with mPAP >20 mmHg at sea level were classified as having mPAP-defined PH, whereas those with mPAP ≤20 mmHg were classified as non-PH (3,5,12). Complete invasive hemodynamic variables, including pulmonary vascular resistance, pulmonary arterial wedge pressure, and cardiac output, were not consistently available in the retrospective dataset. Accordingly, this study evaluated MPA/AA for identifying mPAP-defined PH rather than for establishing a full hemodynamic diagnosis.

Cohort construction

Eligible patients were grouped according to the underlying cardiovascular diagnosis. The primary analysis cohort included children with L-R shunt CHD, including atrial septal defect (ASD), ventricular septal defect (VSD), patent ductus arteriosus (PDA), and mixed shunt lesions. These conditions share a related hemodynamic background characterized by pulmonary overcirculation (18).

Children with cardiovascular diagnoses outside the L-R shunt spectrum were analyzed separately. This heterogeneous non-L-R cohort included idiopathic pulmonary arterial hypertension, pulmonary vein stenosis, pulmonary arteriovenous malformation, bronchial artery-pulmonary artery fistula, coronary artery fistula draining into the right ventricle, and anomalous left coronary artery from the pulmonary artery.

The analysis was conducted in three components: the overall cohort for baseline description and estimation of disease-context upper reference limits in RHC-negative children; the L-R shunt CHD cohort for model development, threshold derivation, and internal validation; and the non-L-R cardiovascular cohort for model transportability assessment.

Reference population and age stratification

The reference population for estimating upper reference limits consisted of children in the overall cohort who had no mPAP-defined PH on RHC. This reference population does not represent a healthy pediatric cohort, but rather children undergoing clinically indicated catheterization in whom mPAP-defined PH was not present on RHC.

Age groups were defined before analysis as follows: infants (3 months to <2 years), preschool children (2 to <7 years), school-age children (7 to <12 years), and adolescents (12 to 18 years) (2,19,20). These strata reflect pediatric somatic and cardiopulmonary growth. The resulting limits were intended for interpretation within this clinical disease context and not as population screening values.

CT acquisition protocol

All patients underwent chest CT using a 256-slice Brilliance iCT scanner (Philips Medical Systems, Best, the Netherlands). Scanning parameters were optimized based on patient weight in line with the as low as reasonably achievable (ALARA) principle. Tube voltage ranged from 80 to 120 kVp, and tube current was automatically modulated. The volume CT dose index ranged from 0.72–6.13 mGy, and the estimated effective dose ranged from 0.35–3.44 mSv, consistent with pediatric ALARA recommendations (21). Only patients with suspected coronary anomalies underwent prospectively electrocardiogram (ECG)-triggered coronary CT angiography. The acquisition window was selected according to heart rate and the clinical protocol. All other examinations were performed without ECG gating. For non-ECG-gated examinations, bolus tracking was used with the region of interest placed in the ascending aorta (AA), and scanning was triggered when attenuation reached 100–120 Hounsfield units (HUs). A nonionic contrast agent, either iodixanol (270 mg I/mL) or iohexol (300 mg I/mL) (GE Healthcare, Chicago, USA), was administered intravenously with a power injector at 1.5–2.0 mL/kg, with a maximum volume of 100 mL. The contrast bolus was followed by a saline flush, constituting a biphasic injection protocol. Saline volume was adjusted according to patient size. The contrast injection rate ranged from 0.6 to 2.0 mL/s and was selected according to body weight and the caliber and condition of the intravenous access. Breath-hold scanning was performed when possible, and sedation was administered to younger children in accordance with institutional protocol. The axial reconstructions (0.625–1.25 mm) were created with a mediastinal kernel.

Image analysis and reproducibility assessment

CT datasets were obtained from the Picture Archiving and Communication System (PACS) and anonymized before analysis. For each prospectively ECG-triggered examination, measurements were obtained from one diastolic reconstruction, preferentially at 75% of the R-R interval and, when unavailable, at 70%. Two fellowship-trained pediatric radiologists with 14 and 10 years of experience performed the measurements independently. Both readers were blinded to clinical information, catheterization results, and each other’s measurements. The MPA and AA diameters were measured on the same axial contrast-enhanced CT image at the level of the pulmonary artery bifurcation. The MPA diameter was defined as the maximum luminal diameter measured as nearly perpendicular as possible to the local vessel axis. The AA diameter was defined as the maximum luminal diameter on the same axial image, with the measurement direction selected according to the shape of the lumen. The measurements were performed on 1.0–1.25-mm axial reconstructed images using a mediastinal window width of 350–450 HU and level of 40–50 HU. Calipers were placed at the inner margins of the contrast-enhanced lumen, excluding the vessel wall (19,22). Figure 2 shows representative examples of the measurement technique.

Figure 2 Measurement of the main pulmonary artery-to-ascending aorta diameter ratio. Axial contrast-enhanced chest CT images obtained at the level of the pulmonary artery bifurcation show the measurement of the MPA and AA on the same image. (A) A 14.7-year-old adolescent with ventricular septal defect and mPAP-defined PH on RHC shows marked enlargement of the MPA compared to the AA. (B) A 13.9-year-old adolescent without mPAP-defined PH on RHC shows a more proportionate relationship between the two vessels. The MPA was measured at its maximum luminal diameter, as nearly perpendicular as possible to the local vessel axis. The AA was measured at its maximum luminal diameter, with the measurement direction selected according to the shape of the lumen. Calipers were placed at the inner margins of the contrast-enhanced lumen, excluding the vessel wall. AA, ascending aorta; CT, computed tomography; MPA, main pulmonary artery; mPAP, mean pulmonary arterial pressure; PH, pulmonary hypertension; RHC, right heart catheterization.

Interobserver reproducibility was assessed in 30 randomly selected cases using a two-way random effects intraclass correlation coefficient (ICC) model. ICCs were calculated for MPA diameter, AA diameter, and MPA/AA.

Statistical analysis

All analyses were performed using R (version 4.5.1). Continuous variables were assessed for normality using the Shapiro-Wilk test and reported as mean ± standard deviation or median with interquartile range (IQR). Between-group comparisons used the Student’s t-test or Mann-Whitney U test for continuous and Chi-squared or Fisher’s exact tests for categorical variables.

In the primary L-R shunt cohort, the association between MPA/AA and mPAP was assessed using Spearman correlation and multivariable linear regression. The main regression model included MPA/AA, age, and sex. Restricted cubic splines adjusted for age and sex were used to examine nonlinearity. Diagnostic performance was also evaluated in the primary L-R shunt cohort. The logistic model used MPA/AA as the predictor and mPAP-defined PH status as the outcome. For ease of presentation, odds ratios from logistic regression were reported per 0.1 increase in MPA/AA. Discrimination was assessed using receiver operating characteristic (ROC) analysis. The Youden index was used to derive the main balanced cutoff, and a second cutoff was selected under a specificity target of at least 0.95. Internal validation used 1,000 bootstrap resamples to estimate optimism-corrected discrimination and calibration. Decision-curve analysis was used to examine clinical utility across clinically relevant threshold probabilities.

Age-stratified upper reference limits for MPA/AA were estimated in children without mPAP-defined PH on RHC from the overall included cohort using 95th-percentile quantile regression. A restricted cubic spline was used for age, and bootstrap resampling was used to derive the 95% confidence interval (CI). Locally estimated scatterplot smoothing was used only to describe the median age trend. Model transportability was assessed by applying the diagnostic model derived from the primary L-R shunt cohort to the non-L-R cohort.

For the multivariable linear regression relating MPA/AA to mPAP, sensitivity analysis included additional adjustment for L-R shunt subtype. For the diagnostic logistic model used to identify mPAP-defined PH in the primary L-R shunt cohort, we fitted two adjusted models as sensitivity analyses: one adjusted for age alone and the other for age and sex. Secondary analyses also evaluated diagnostic performance within L-R shunt subtypes. Statistical significance was defined as two-sided P<0.05.

Results

Analytic cohort and baseline characteristics

The final analytic cohort included 231 children, including 164 in the primary L-R shunt CHD cohort and 67 in the non-L-R cardiovascular cohort (Figure 1). The median CT-RHC interval was 10.0 days (IQR, 6.0–23.5 days). None of the 164 examinations in the primary cohort was ECG-gated. Nine of the 67 examinations in the non-L-R cohort used prospective ECG triggering, including five children with anomalous left coronary artery from the pulmonary artery and four with coronary artery fistula draining into the right ventricle.

mPAP-defined PH was present in 122 of 231 children (52.8%), whereas 109 (47.2%) were classified as non-PH. The median age of the overall cohort was 3.70 years (IQR, 0.90–7.80 years), and the median MPA/AA ratio was 1.34 (IQR, 1.15–1.58). Among the 164 children in the primary L-R shunt CHD cohort, 110 (67.1%) had PH. The baseline characteristics of the overall cohort are summarized in Table 1. A direct baseline comparison between the primary L-R shunt cohort and the non-L-R cardiovascular cohort is provided in Table S2.

Measurement reproducibility, MPA/AA distribution, and invasive hemodynamic association

Interobserver reproducibility was high. ICCs were 0.93 for MPA diameter (95% CI: 0.85–0.96), 0.98 for AA diameter (95% CI: 0.95–0.99), and 0.91 for MPA/AA (95% CI: 0.82–0.96; all P<0.001).

In the primary L-R shunt cohort, MPA/AA was significantly higher in children with mPAP-defined PH than in non-PH children (median 1.56 vs. 1.22; P<0.001). The distributions showed clear separation, although some overlap remained near the diagnostic range (Figure 3).

Figure 3 Distribution of the MPA/AA in children with and without mPAP-defined PH in the left-to-right shunt cohort. Raincloud plot of the distribution of the MPA/AA ratio in children with mPAP-defined PH compared with those without mPAP-defined PH. The plot includes individual data points, a kernel density estimate, and a box-and-whisker representation for each group. MPA/AA, main pulmonary artery-to-ascending aorta ratio; mPAP, mean pulmonary arterial pressure; PH, pulmonary hypertension.

MPA/AA correlated positively with mPAP (Spearman r=0.69, P<0.001). In the multivariable linear regression model adjusted for age and sex, each 1-unit increase in MPA/AA was associated with a 37.85-mmHg increase in mPAP. Further adjustment for shunt subtype produced a similar estimate of 35.96 mmHg. The restricted cubic spline showed an approximately linear association, with modest curvature at higher MPA/AA values (Figure 4).

Figure 4 Association between the MPA/AA and mPAP. Scatter points show individual mPAP values plotted against corresponding MPA/AA ratios. The solid curve indicates the restricted cubic spline fit with 95% confidence interval. The vertical dashed line denotes the MPA/AA cutoff of the optimal Youden index (1.40). MPA/AA, main pulmonary artery-to-ascending aorta ratio; mPAP, mean pulmonary arterial pressure.

Diagnostic performance of MPA/AA ratio for PH in the primary L-R shunt cohort

In the primary L-R shunt cohort, the MPA/AA-based logistic model yielded an area under the curve (AUC) of 0.94 (95% CI: 0.90–0.97). The Youden-optimal cutoff was 1.40, providing a sensitivity of 84.5% and a specificity of 92.6%. When a specificity-oriented rule was applied, the cutoff increased to 1.44, giving a specificity of 96.3% and a sensitivity of 73.6%. The summary diagnostic values are shown in Table 2, and the ROC curve and threshold notes are shown in Figure 5A. In sensitivity analyses, discrimination changed little after adjustment for age alone or for age and sex compared with the univariable model (AUC, 0.94 for both adjusted models; 95% CI: 0.91–0.98). A comparison of the univariable and adjusted logistic models is provided in Table S3.

Figure 5 Discrimination, calibration, and decision-curve analysis of the MPA/AA for identifying mean pulmonary arterial pressure-defined pulmonary hypertension. (A) Receiver-operating characteristic curve shows the diagnostic performance of the MPA/AA in the left-to-right shunt congenital heart disease cohort, with an area under the curve of 0.94. The dashed diagonal is the line of no discrimination. Annotated points indicate key thresholds, including the Youden-optimal cutoff (1.40) and the threshold corresponding to specificity ≥95% (1.44). (B) Calibration plot of the logistic regression model. The diagonal dashed line represents ideal calibration. The apparent calibration curve and the bootstrap-corrected calibration curve derived from 1,000 resamples are shown and demonstrate close agreement across the entire range of predicted probabilities. (C) The decision curve shows the net benefit of using the MPA/AA ratio across a range of threshold probabilities. The blue line represents the model, while the dashed and dotted gray lines depict the default strategies of treating all patients and treating none, respectively. Two annotated points indicate key diagnostic thresholds: the Youden-optimal cutoff (1.40) and the threshold corresponding to specificity ≥95% (1.44). AUC, area under the curve; CI, confidence interval; MPA/AA, main pulmonary artery-to-ascending aorta ratio.

Internal validation, calibration, and decision-curve analysis

Bootstrap internal validation (1,000 resamples) showed limited overfitting with the optimism-corrected AUC matching the apparent AUC (0.94). Calibration performance was acceptable (slope =0.98; intercept =0.01), and the Brier score was 0.0995 (Figure 5B). Decision-curve analysis suggested a net benefit for the MPA/AA-based model across clinically relevant threshold probabilities compared with default strategies of treating all or treating none (Figure 5C).

Upper reference limits in RHC-negative children

Age-stratified upper reference limits were derived from the RHC-negative subset of the overall included cohort. As summarized in Table 3, median MPA/AA values gradually declined with age. In the continuous age model, the spline-derived maximum 95th-percentile limit was 1.39, numerically close to but still below the Youden-derived diagnostic threshold of 1.40 (Figure 6). These upper reference limits describe an RHC-negative cardiovascular disease context and should not be used as normal reference values for healthy children.

Figure 6 Age-dependent upper reference limits of the MPA/AA in children without mean pulmonary arterial pressure-defined pulmonary hypertension on right heart catheterization. Scatter points represent MPA/AA measurements across different ages. The solid line shows the age-specific 95th-percentile limits derived using quantile regression, with the shaded band indicating the bootstrap-derived 95% confidence interval. The dashed curve depicts the median trend estimated using locally estimated scatterplot smoothing and is shown for descriptive purposes only. The horizontal dashed line marks the diagnostic threshold of 1.40, determined by the Youden index. CI, confidence interval; LOESS, locally estimated scatterplot smoothing; MPA/AA, main pulmonary artery-to-ascending aorta ratio; URL, upper reference limit.

Model transportability assessment in the non-L-R cardiovascular cohort

Model transportability assessment was performed in the heterogeneous non-L-R cardiovascular cohort (n=67). In this setting, the model retained discrimination but showed weaker calibration, with an AUC of 0.84 (95% CI: 0.71–0.98) and a calibration slope of 0.54. Diagnostic results in the non-L-R cohort are summarized in Table S4, and the ROC curve is displayed in Figure S1. These results should be regarded as an assessment of model performance in a heterogeneous disease group.

L-R shunt CHD subtype analyses

Among L-R shunt subtypes, children with mixed lesions had the highest prevalence of PH (92.7%) and the most elevated MPA/AA (median 1.63; IQR, 1.42–1.79). PDA and VSD showed PH prevalence of 70.3% and 56.2%, with MPA/AA of 1.44 (IQR, 1.30–1.58) and 1.52 (IQR, 1.23–1.72), respectively. In contrast, children with ASD had the lowest PH prevalence (33.3%) and only slightly increased MPA/AA values. Diagnostic performance of the MPA/AA-based logistic model within the four subtypes is presented in Table S5. The MPA/AA distribution within each subtype stratified by PH status is depicted in Figure S2.

Discussion

In this study, CT-derived MPA/AA showed high discrimination for mPAP-defined PH in children with L-R shunt CHD. The primary cohort supported two clinically interpretable thresholds, a balanced Youden-derived cutoff of 1.40 and a more specificity-oriented cutoff of 1.44. Disease-context upper reference limits showed limited age-related variation in RHC-negative children, whereas model application to the heterogeneous non-L-R cohort supported transportability assessment only, not external validation.

The higher MPA/AA observed in children with PH should be understood in the context of L-R shunt physiology. In these patients, increased pulmonary blood flow may enlarge the proximal pulmonary artery even when pulmonary pressure does not increase (17). Therefore, the non-PH group cannot be considered a physiologically normal reference group. Despite this flow-loaded background, children with mPAP-defined PH on RHC still showed higher MPA/AA values. This suggests that the ratio captures arterial enlargement beyond expected flow-mediated dilatation, likely reflecting the additional effects of pressure overload, reduced pulmonary arterial compliance, and pulmonary vascular remodeling. This interpretation is consistent with current understanding of pediatric PH and CHD-associated PH (2,3,5,18). Previous pediatric CT studies also found higher MPA/AA values in children with PH than in controls, although their control populations and disease compositions differed from ours (14,15). Such differences are important because thresholds derived from healthy children or mixed pediatric cohorts may not apply directly to children with L-R shunt lesions. In this context, the balanced cutoff of 1.40 may be more appropriate as the primary interpretive threshold. A false-negative CT finding could delay further hemodynamic evaluation, whereas a false-positive finding would prompt additional clinical assessment followed by RHC confirmation if clinically indicated.

The association between MPA/AA and mPAP remained after adjustment for age, sex, and L-R shunt subtype. Adjustment for age and sex also had little effect on diagnostic discrimination. Together with its high interobserver reproducibility, these findings support the use of MPA/AA as a practical marker on standard axial CT images. However, this anatomic ratio does not reflect vascular compliance, three-dimensional remodeling, regional stiffness, or pressure-area behavior. Area-based, volumetric, and multiparametric CT approaches may provide complementary information (7,23), but their evaluation requires standardized measurement, reproducibility assessment, appropriate handling of correlated predictors, and separate model validation. Consequently, MPA/AA should be regarded as a complementary diagnostic imaging marker, rather than a quantitative surrogate for invasive pressures.

The upper reference limits analysis was designed to provide reference information for children undergoing cardiovascular evaluation, rather than normative values for healthy children. This distinction is important because the reference subset consisted of children without mPAP-defined PH on RHC, many of whom still had cardiovascular disease and flow-related pulmonary arterial enlargement. Consistent with this background, the overall non-PH median MPA/AA in our cohort was 1.16, slightly higher than the approximately 1.09 reported in healthy pediatric populations by Compton et al. (19). The age-stratified 95th-percentile limits ranged from 1.33 to 1.39, and the spline-derived maximum limit was 1.39, just below the diagnostic cutoff of 1.40. This numerical proximity suggests internal consistency between the reference-limit analysis and the diagnostic-threshold analysis, but the two values are not interchangeable and should not be viewed as mutual validation.

Model transportability assessment in the non-L-R cardiovascular cohort showed preserved discrimination but weaker calibration. This pattern is understandable because the non-L-R cardiovascular cohort included heterogeneous cardiovascular conditions with different mechanisms of pulmonary vascular enlargement and pressure loading. The result suggests that MPA/AA may retain some diagnostic value outside the L-R shunt setting, but risk estimates and thresholds derived from the primary cohort should not be assumed to transfer directly to other pediatric PH phenotypes. In children with L-R shunt CHD, it may provide an objective anatomical clue when echocardiographic pressure estimation is technically limited or discordant with clinical suspicion (12,18,24). Its role should remain adjunctive, and assessment should consider symptoms, echocardiographic findings, lesion type, and catheterization data when available.

There are some limitations that should be noted. First, this single-center retrospective design may limit generalizability. Moreover, baseline data were not systematically available for excluded candidates, precluding a formal comparison between included and excluded patients. Second, because only mPAP was consistently available in the retrospective RHC records, this study addressed mPAP-defined PH rather than full hemodynamic classification. Third, the thresholds were derived and internally validated in children with L-R shunt CHD and require independent external validation. Fourth, cardiac-phase effects could not be evaluated because the primary cohort underwent non-ECG-gated CT and paired measurements across cardiac phases were unavailable. Sedation or anesthesia status, medication type, and respiratory phase were not systematically documented and may have contributed to measurement variability. Fifth, this study focused on MPA/AA and did not evaluate area-based, body-size-indexed, or multiparametric CT measures. Their incremental value requires prospective investigation with standardized measurement and independent validation. Finally, although age-stratified analysis suggested only modest variation in MPA/AA across age groups in RHC-negative children, the reported threshold should be regarded as study-specific rather than age-specific.

Conclusions

In children with L-R shunt CHD, CT-derived MPA/AA showed high discrimination for identifying mPAP-defined PH. The disease-context upper reference limits derived from RHC-negative children may help understand pulmonary arterial enlargement in this flow-loaded population. MPA/AA may serve as a practical adjunctive marker on clinically indicated CT but cannot replace RHC.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STARD reporting checklist. Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1-2760/rc

Data Sharing Statement: Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1-2760/dss

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1-2760/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board of Children’s Hospital of Chongqing Medical University (No. 2025120), and individual consent for this retrospective analysis was waived.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Kuang M, Chen Y, Xing Y, Du M, Feng H, Yang Q, Wen D, Li X, Yang K, Lin Z, Lai N, Jiang Q, Liu S, Zhou D, Hong W, Fu X, Lu W, Zhao T, Wang J, Chen Y. Echocardiographic evaluation of right heart failure which might be associated with DNA damage response in SU5416-hypoxia induced pulmonary hypertension rat model. Respir Res 2023;24:202. [Crossref] [PubMed]
2. Mukherjee D, Konduri GG. Pediatric Pulmonary Hypertension: Definitions, Mechanisms, Diagnosis, and Treatment. Compr Physiol 2021;11:2135-90. [Crossref] [PubMed]
3. Rosenzweig EB, Abman SH, Adatia I, Beghetti M, Bonnet D, Haworth S, Ivy DD, Berger RMF. Paediatric pulmonary arterial hypertension: updates on definition, classification, diagnostics and management. Eur Respir J 2019;53:1801916. [Crossref] [PubMed]
4. Brida M, Nashat H, Gatzoulis MA. Pulmonary arterial hypertension: closing the gap in congenital heart disease. Curr Opin Pulm Med 2020;26:422-8. [Crossref] [PubMed]
5. Hansmann G, Koestenberger M, Alastalo TP, Apitz C, Austin ED, Bonnet D, et al. 2019 updated consensus statement on the diagnosis and treatment of pediatric pulmonary hypertension: The European Pediatric Pulmonary Vascular Disease Network (EPPVDN), endorsed by AEPC, ESPR and ISHLT. J Heart Lung Transplant 2019;38:879-901. [Crossref] [PubMed]
6. Ivy D, Rosenzweig EB, Abman SH, Beghetti M, Bonnet D, Douwes JM, Manes A, Berger RMF. Embracing the challenges of neonatal and paediatric pulmonary hypertension. Eur Respir J 2024;64:2401345. [Crossref] [PubMed]
7. Truong QA, Bhatia HS, Szymonifka J, Zhou Q, Lavender Z, Waxman AB, Semigran MJ, Malhotra R. A four-tier classification system of pulmonary artery metrics on computed tomography for the diagnosis and prognosis of pulmonary hypertension. J Cardiovasc Comput Tomogr 2018;12:60-6. [Crossref] [PubMed]
8. Chen R, Liao H, Deng Z, He Z, Zheng Z, Lu J, Jiang M, Wu X, Guo W, Huang Z, Chen H, Hong C, Zhong N. Efficacy of computed tomography in diagnosing pulmonary hypertension: A systematic review and meta-analysis. Front Cardiovasc Med 2022;9:966257. [Crossref] [PubMed]
9. Narendra Kumar K, Singh NG, Nagaraja PS, Patil TA, Manjunath N. Transesophageal Echocardiographic Assessment of Pulmonary Artery-to-Ascending Aorta Ratio for the Detection of Pulmonary Hypertension in Cardiac Surgical Patients. J Cardiothorac Vasc Anesth 2017;31:1702-6. [Crossref] [PubMed]
10. Ratanawatkul P, Oh A, Richards JC, Swigris JJ. Performance of pulmonary artery dimensions measured on high-resolution computed tomography scan for identifying pulmonary hypertension. ERJ Open Res 2020;6:00232-2019. [Crossref] [PubMed]
11. Kaemmerer H, Diller GP, Dähnert I, Achenbach S, Eichstaedt CA, Eicken A, et al. Pulmonary hypertension in adults with congenital heart defects (ACHDs)-in light of the 2022 ESC PAH guidelines-part I: definition, epidemiology, classification, diagnostics, genetics, risk stratification and follow-up, gender aspects. Cardiovasc Diagn Ther 2024;14:935-48. [Crossref] [PubMed]
12. Humbert M, Kovacs G, Hoeper MM, Badagliacca R, Berger RMF, Brida M, et al. 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. Eur Respir J 2023;61:2200879. [Crossref] [PubMed]
13. Chen SJ, Huang JH, Lee WJ, Lin MT, Chen YS, Wang JK. Diagnosis of Pulmonary Arterial Hypertension in Children by Using Cardiac Computed Tomography. Korean J Radiol 2019;20:976-84. [Crossref] [PubMed]
14. Berteloot L, Proisy M, Jais JP, Lévy M, Boddaert N, Bonnet D, Raimondi F. Idiopathic, heritable and veno-occlusive pulmonary arterial hypertension in childhood: computed tomography angiography features in the initial assessment of the disease. Pediatr Radiol 2019;49:575-85. [Crossref] [PubMed]
15. Caro-Domínguez P, Compton G, Humpl T, Manson DE. Pulmonary arterial hypertension in children: diagnosis using ratio of main pulmonary artery to ascending aorta diameter as determined by multi-detector computed tomography. Pediatr Radiol 2016;46:1378-83. [Crossref] [PubMed]
16. Saetung M, Kritsaneepaiboon S, Jarutach J. Main pulmonary artery-to-descending aorta ratio in computed tomography: cut-off value to diagnose pulmonary hypertension in children. Pol J Radiol 2021;86:e87-92. [Crossref] [PubMed]
17. Kaldararova M, Bobocka K, Kantorova A, Drangova E, Polakova Mistinova J, Klauco F, Hlavata T, Reptova A, Valkovicova T, Simkova I. Pulmonary Artery Dilatation Due to Pressure or Volume Overload in Congenital Heart Disease. J Clin Med 2024;13:1567. [Crossref] [PubMed]
18. Jone PN, Ivy DD, Hauck A, Karamlou T, Truong U, Coleman RD, Sandoval JP, Del Cerro Marín MJ, Eghtesady P, Tillman K, Krishnan US. Pulmonary Hypertension in Congenital Heart Disease: A Scientific Statement From the American Heart Association. Circ Heart Fail 2023;16:e00080. [Crossref] [PubMed]
19. Compton GL, Florence J, MacDonald C, Yoo SJ, Humpl T, Manson D. Main Pulmonary Artery-to-Ascending Aorta Diameter Ratio in Healthy Children on MDCT. AJR Am J Roentgenol 2015;205:1322-5. [Crossref] [PubMed]
20. McGoon MD, Benza RL, Escribano-Subias P, Jiang X, Miller DP, Peacock AJ, Pepke-Zaba J, Pulido T, Rich S, Rosenkranz S, Suissa S, Humbert M. Pulmonary arterial hypertension: epidemiology and registries. J Am Coll Cardiol 2013;62:D51-9. [Crossref] [PubMed]
21. Baldassarre LA, Mendes LA, Blankstein R, Hahn RT, Patel AR, Russell R, et al. 2025 ACC/AHA/ASE/ASNC/SCCT/SCMR Advanced Training Statement on Advanced Cardiovascular Imaging: A Report of the ACC Competency Management Committee. J Cardiovasc Magn Reson 2025;27:101977. [Crossref] [PubMed]
22. Mahammedi A, Oshmyansky A, Hassoun PM, Thiemann DR, Siegelman SS. Pulmonary artery measurements in pulmonary hypertension: the role of computed tomography. J Thorac Imaging 2013;28:96-103. [Crossref] [PubMed]
23. Melzig C, Wörz S, Egenlauf B, Partovi S, Rohr K, Grünig E, Kauczor HU, Heussel CP, Rengier F. Combined automated 3D volumetry by pulmonary CT angiography and echocardiography for detection of pulmonary hypertension. Eur Radiol 2019;29:6059-68. [Crossref] [PubMed]
24. Aluja Jaramillo F, Gutierrez FR, Díaz Telli FG, Yevenes Aravena S, Javidan-Nejad C, Bhalla S. Approach to Pulmonary Hypertension: From CT to Clinical Diagnosis. Radiographics 2018;38:357-73. [Crossref] [PubMed]