{
  "abstract": "Introduction Interstitial lung disease (ILD) is a leading cause of death in systemic sclerosis (SSc), especially when extensive ILD is identified through visual scoring of computed tomography (CT). Automated post-processing analysis software can compute ILD extent through lung texture analysis (LTA) of CT images. However, a definition of ILD presence and extensive disease using this technology are lacking. We aimed to identify and validate optimal thresholds of ILD extent quantified through LTA to detect the presence of SSc-ILD and of extensive involvement.Material and Methods SSc patients visiting the Rheumatology Departments of University Hospital Zurich and the Careggi University Hospital Florence were included. Technically suitable images were analyzed through LTA™ (Imbio), quantifying the percentage of lung volume occupied by ILD, as sum of ground glass, reticulation and honeycombing. Two blinded radiologists independently reviewed the CT scans to identify ILD and extensive disease, the latter defined as >20% of lung parenchyma involved, with disagreements resolved by consensus or third reviewer. Patients were randomly split 2:1 into derivation and validation cohorts. Receiver operating characteristic (ROC) curves with area under the curve (AUC) were computed to identify the optimal ILD extent threshold for detecting ILD and extensive disease, using the visual evaluation as the reference standard. Cox regression analysis was performed to determine the impact of ILD and extensive disease by LTA™ on mortality, adjusted for confounders (age, sex, diffuse skin subset, pulmonary hypertension).Results A total of 664/1118 (58%) SSc patients were eligible for the study. Visual analysis identified ILD in 313 (47%) cases, of whom 103 (33%) extensive ILD. In the derivation cohort (433 patients, 206 ILD, 38% extensive), ROC analysis identified the optimal ILD extent threshold for ILD detection at 1% (AUC 0.83), and at 7% for extensive ILD (AUC 0.84). In the validation cohort (231 patients, 104 ILD, 25% extensive), these thresholds achieved 78% sensitivity/71% specificity for ILD presence, and 81% sensitivity/70% specificity for extensive ILD. Over a median 5 years follow-up, 84 (13%) patients died (37 in the ILD group). Adjusted for confounders, both ILD presence and extensive ILD independently predicted mortality, with comparable results by visual and LTA™ assessments.Conclusions Cutoffs for total ILD by LTA™ to detect ILD presence and identify extensive cases were derived and validated, both predicting a negative prognosis, comparably to visual evaluation. Our results lay the foundation for expanding the use of post-processing analysis in SSc-ILD towards automated diagnosis and stratification.",
  "authors": [
    {
      "affiliations": [
        "Department of Radiological Sciences, Oncology and Pathology, Sapienza University, Policlinico Umberto I, Rome, Italy"
      ],
      "name": "Nicholas Landini"
    },
    {
      "affiliations": [
        "Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University Zurich, Zurich, Switzerland"
      ],
      "name": "Lisa Jungblut"
    },
    {
      "affiliations": [
        "Advanced Radiology Center, Department of Diagnostic Imaging and Oncological Radiotherapy, Fondazione Policlinico Gemelli, Rome, Italy"
      ],
      "name": "Cecilia Strappa"
    },
    {
      "affiliations": [
        "Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University Zurich, Zurich, Switzerland"
      ],
      "name": "Christian Bluethgen"
    },
    {
      "affiliations": [
        "Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland"
      ],
      "name": "Rucsandra Dobrota"
    },
    {
      "affiliations": [
        "Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland"
      ],
      "name": "Muriel Elhai"
    },
    {
      "affiliations": [
        "Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland"
      ],
      "name": "Carina Mihai"
    },
    {
      "affiliations": [
        "Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland"
      ],
      "name": "Sinziana Muraru"
    },
    {
      "affiliations": [
        "Rheumatology Unit, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena an, Modena, Italy"
      ],
      "name": "Martina Orlandi"
    },
    {
      "affiliations": [
        "Division of Radiology, Fondazione Toscana Gabriele Monasterio, Pisa, Italy"
      ],
      "name": "Mariaelena Occhipinti"
    },
    {
      "affiliations": [
        "Department of Health Science, University of Florence, Florence, Italy"
      ],
      "name": "Khadija El Aoufy"
    },
    {
      "affiliations": [
        "Department of Experimental and Clinical Medicine, University of Florence, Division of Rheumatology Scleroderma Unit, AOU, Florence, Italy"
      ],
      "name": "Gemma Lepri"
    },
    {
      "affiliations": [
        "Department of Radiological Sciences, Oncology and Pathology, Sapienza University, Policlinico Umberto I, Rome, Italy"
      ],
      "name": "Valeria Panebianco"
    },
    {
      "affiliations": [
        "Advanced Radiology Center, Department of Diagnostic Imaging and Oncological Radiotherapy, Fondazione Policlinico Gemelli, Rome, Italy"
      ],
      "name": "Anna Rita Larici"
    },
    {
      "affiliations": [
        "Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland",
        "Department of Rheumatology, Oslo University Hospital, Oslo, Norway"
      ],
      "name": "Anna Maria Hoffmann-Vold"
    },
    {
      "affiliations": [
        "Department of Experimental and Clinical Biomedical Sciences, Radiodiagnostic Unit n. 2, University of Florence - Azienda, Florence, Italy"
      ],
      "name": "Cosimo Nardi"
    },
    {
      "affiliations": [
        "Department of Experimental and Clinical Medicine, University of Florence, Division of Rheumatology Scleroderma Unit, AOU, Florence, Italy"
      ],
      "name": "Serena Guiducci"
    },
    {
      "affiliations": [
        "Department of Experimental and Clinical Medicine, University of Florence, Division of Rheumatology Scleroderma Unit, AOU, Florence, Italy"
      ],
      "name": "Silvia Bellando-Randone"
    },
    {
      "affiliations": [
        "Unit of Immunology, Rheumatology, Allergy and Rare diseases (UNIRAR), Inflammation, fibrosis and ageing initiative (INFL, Milan, Italy"
      ],
      "name": "Marco Matucci-Cerinic"
    },
    {
      "affiliations": [
        "Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University Zurich, Zurich, Switzerland"
      ],
      "name": "Thomas Frauenfelder"
    },
    {
      "affiliations": [
        "Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland"
      ],
      "name": "Oliver Distler"
    },
    {
      "affiliations": [
        "Department of Rheumatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland",
        "Department of Experimental and Clinical Medicine, University of Florence, Division of Rheumatology Scleroderma Unit, AOU, Florence, Italy"
      ],
      "name": "Cosimo Bruni"
    }
  ],
  "title": "P.118 Detecting interstitial lung disease and identifying extended disease on chest computed tomography in patients with systemic sclerosis: cut-offs for lung texture analysis and its prognostic implication",
  "uid": "9661c1ff-f376-52aa-82a9-11e24a0b2151"
}