{
  "abstract": "Introduction and Objectives Main pulmonary artery diameter (MPA) and MPA to aorta diameter ratio (MPA:Ao) on CTPA are recognised imaging biomarkers of pulmonary hypertension (PH). Manual two-dimensional (2D) measurements may not capture true MPA in three-dimensional (3D) space; they are also prone to inter-observer error and are not reliably reported in clinical practice. 1 We developed and evaluated an automated CTPA analysis pipeline for 3D MPA and MPA:Ao extraction to predict PH at right heart catheterisation (RHC) versus manual 2D measurements. Hypothetical clinical impact was assessed in a cohort with chronic thrombo-embolic pulmonary disease (CTEPD) and low echocardiographic probability of PH.2 Methods Retrospective study in 284 consecutive CTPAs within 6 months of diagnostic RHC (age 63±14 years, 39% male (111/284)).The pipeline was trained (n=95, 37372 slices) and validated (n=24, 9696 slices) using manually labelled segmentations. Optimal thresholds for PH at gold-standard RHC for 2D and 3D measurements were derived (n=70, 27613 slices) and tested (n=95, 35232 slices).Theoretical clinical impact was assessed in a consecutive CTEPD cohort (n=50, age 58±17, 56% male (28/50)). We evaluated reclassification of PH risk pre-RHC using 3D measurements.Results Automated 3D measurements were feasible in 98% (278/284) and correlated with manual 2D measurements (R 2=0.82).Automated 3D MPA:Ao correctly identified significantly more patients with PH in the test cohort (90% (55/61) vs. 71% (43/61) X2=16.5, p<0.05).In the CTEPD cohort, MPA:Ao was recorded in only 12% (6/50) of contemporaneous routine clinical reports. 62% (31/50) had PH at RHC. 3D MPA:Ao correctly predicted PH in 77% (24/31) with a specificity of 53% (see figure 1).Abstract P282 Figure 1Sankey Diagram demonstrating re-classification of pulmonary hypertension risk pre-right heart catheterisation using automated 3D measurements on CTPA in a cohort of patients with chronic thrombo-embolic pulmonary disease and low probability of pulmonary hypertension on echocardiography by ESC/ERS guidelinesConclusions Automated 3D measurements from CTPA are feasible, more reproducible than routine clinical practice and 3D MPA:Ao has the best diagnostic performance. In a low probability echocardiography cohort, automated 3D measurements identified additional cases of PH in theoretical pre-RHC risk stratification.References Foley, et al. Automated calculation of the right ventricle to left ventricle ratio on CT for the risk stratification of patients with acute pulmonary embolism. Eur Radiol. 2021 Aug;31(8):6013–20.Humbert, et al. 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. European Respiratory Journal.",
  "authors": [
    {
      "affiliations": [
        "Royal United Hospitals Bath, Bath, UK",
        "University of Bath, Bath, UK"
      ],
      "name": "J Rossdale"
    },
    {
      "affiliations": [
        "University of Bath, Bath, UK"
      ],
      "name": "A Mir"
    },
    {
      "affiliations": [
        "Royal United Hospitals Bath, Bath, UK"
      ],
      "name": "P Charters"
    },
    {
      "affiliations": [
        "Royal United Hospitals Bath, Bath, UK"
      ],
      "name": "H Wong"
    },
    {
      "affiliations": [
        "Royal United Hospitals Bath, Bath, UK"
      ],
      "name": "J Page"
    },
    {
      "affiliations": [
        "Royal United Hospitals Bath, Bath, UK"
      ],
      "name": "R Mackenzie Ross"
    },
    {
      "affiliations": [
        "Royal United Hospitals Bath, Bath, UK",
        "University of Bath, Bath, UK"
      ],
      "name": "J Suntharalingam"
    },
    {
      "affiliations": [
        "University of Bath, Bath, UK"
      ],
      "name": "A Cookson"
    },
    {
      "affiliations": [
        "University of Bath, Bath, UK"
      ],
      "name": "J Clark"
    },
    {
      "affiliations": [
        "Royal United Hospitals Bath, Bath, UK",
        "University of Bath, Bath, UK"
      ],
      "name": "JCL Rodrigues"
    }
  ],
  "title": "P282 Automated three-dimensional measurements of maximum pulmonary artery diameter and ratio with aorta on CT pulmonary angiogram are predictive of pulmonary hypertension in patients with low probability echocardiography",
  "uid": "d562d745-d94e-53ea-bb81-99b3ec6c1958"
}