Rapid Identification of Infectious Pathogens in Severe Pneumonia Guided by Bronchoscopic Imaging and Lung CT (IMG-GUIDE-IP)

Clinical Study on Rapid Identification of Infectious Pathogens in Severe Pneumonia Patients Based on Bronchoscopic Imaging and Lung CT Guidance

Severe pneumonia requires rapid and accurate diagnosis for targeted treatment, but single lung CT has limitations in identifying pathogens and distinguishing infectious/non-infectious etiologies. This is a retrospective self-controlled study enrolling patients diagnosed with severe pneumonia at the institution between 2024 and 2025 (recruitment will be extended 6-12 months if fewer than 400 patients are enrolled), all of whom underwent both single lung CT and bronchoscopy-combined CT examinations.

Clinical data will be collected retrospectively, including demographic information, bronchoscopic mucosal findings (e.g., congestion, exudation), lung CT lesion characteristics (e.g., consolidation, ground-glass opacity), and gold standard diagnostic results (pathogenic detection or clinical comprehensive diagnosis). The core objective is to compare the diagnostic precision between single lung CT and bronchoscopy-combined CT, focusing on accuracy, sensitivity, and specificity across three etiological subtypes (bacterial/fungal, viral, non-infectious).

Bronchoscopy complements CT by directly visualizing airway mucosal changes, while CT provides panoramic views of pulmonary lesions. Their combination is hypothesized to improve diagnostic accuracy. The findings aim to optimize diagnostic strategies for severe pneumonia, guiding clinicians to select more effective imaging approaches.

Study Overview

• Status: Not yet recruiting
• Conditions: Severe Pneumonia
• Intervention / Treatment: Diagnostic test: Standalone Lung CT for Severe Pneumonia Diagnosis; Diagnostic test: Bronchoscopic Imaging + Lung CT for Severe Pneumonia diagnosis

• Study Type: Observational
• Enrollment (Estimated): 400

Contacts and Locations

• Study Contact: Name: Hongxiang Li; Phone Number: 86+15804301569; Email: li_hx@jlu.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

The study population includes adult patients (≥18 years old) admitted to the study institution between January 2024 and December 2025, with a confirmed diagnosis of severe pneumonia (per Chinese clinical guidelines for community-acquired or hospital-acquired pneumonia). All included patients must have undergone both standalone lung CT and bronchoscopic imaging (CT-guided) during hospitalization, with complete imaging records. They also need to have completed at least one microbial gold standard test (e.g., pathogen culture, nucleic acid detection) with available reports, and intact electronic medical records (demographics, treatment, prognosis).

Patients are excluded if they have incomplete imaging/microbial data, bronchoscopy for non-diagnostic purposes, duplicate admissions, or are under 18 years old.

Description

Inclusion Criteria:

• Patients admitted to the study institution between January 2024 and December 2025, with a clinical diagnosis of severe pneumonia (consistent with the diagnostic criteria of the Chinese Guidelines for the Diagnosis and Treatment of Community-Acquired Pneumonia.
• Patients who underwent both standalone lung CT examination and bronchoscopic imaging examination during hospitalization; complete imaging reports and bronchoscopy operation records are available.
• Patients who completed at least one type of microbial standard test (as defined in Primary Outcome Measure: e.g., pathogen culture, nucleic acid detection, GM test); complete test reports are available.
• Medical Records: Complete electronic medical records are available, including demographic information (age, gender), clinical symptoms, treatment regimens, and prognosis data (length of hospital stay, in-hospital mortality).

Exclusion Criteria:

• Imaging/Microbial Data Deficiency: Patients with incomplete imaging data (e.g., missing lung CT images, unrecorded bronchoscopic mucosal changes) or unavailable microbial gold standard test results.
• Bronchoscopy Contraindications: Patients who underwent bronchoscopic imaging for non-diagnostic purposes (e.g., foreign body removal, hemostasis) or had bronchoscopy-related complications (e.g., severe hemorrhage, pneumothorax) that affected examination completion.
• Duplicate Enrollment: Patients who were admitted multiple times for severe pneumonia during the study period; only the first admission is included to avoid duplicate data.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Severe Pneumonia Patients with Dual Diagnostic Assessments; This retrospective cohort includes patients diagnosed with severe pneumonia who were admitted to the study institution between 2024 and 2025 (recruitment will be extended 6-12 months if fewer than 400 patients are enrolled). All patients in this cohort underwent two diagnostic procedures (standalone lung CT, and bronchoscopic imaging combined with lung CT) during their clinical management. The cohort is designed for self-controlled comparison: diagnostic accuracy of the two methods for infectious pathogen identification will be analyzed to verify the value of the combined imaging approach.

Diagnostic test: Standalone Lung CT for Severe Pneumonia Diagnosis; Standard chest CT scan (including plain scan and/or enhanced scan as clinically needed) performed to evaluate pulmonary lesion location, scope, and imaging features (e.g., consolidation, ground-glass opacity). The CT findings will be used to preliminarily infer the presence of infectious pathogens and guide initial clinical judgment.; Diagnostic test: Bronchoscopic Imaging + Lung CT for Severe Pneumonia diagnosis; Based on pre-existing lung CT images (to locate lesions), flexible bronchoscopy is performed to directly observe mucosal changes in the tracheobronchial tree (e.g., congestion, edema, exudation). Bronchoscopic imaging features are combined with CT findings to comprehensively judge the type of infectious pathogen (e.g., bacterial vs. viral) and improve diagnostic accuracy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic Accuracy of Two Imaging Methods for Infectious Pathogens in Severe Pneumonia	For each patient in the cohort, the diagnostic results of standalone lung CT and bronchoscopic imaging + lung CT will be compared with the "standard for pathogen diagnosis" (e.g., pathogen culture, nucleic acid detection, serological testing) to calculate two key indicators: 1. Sensitivity: The proportion of patients with positive gold standard results that are correctly identified as positive by the diagnostic method; >2. Specificity: The proportion of patients with negative gold standard results that are correctly identified as negative by the diagnostic method. primary goal is to verify whether the combined imaging method (bronchoscopy + CT) has higher sensitivity and specificity than standalone CT for identifying infectious pathogens (including bacteria, fungi, and viruses).	Data collection will be completed retrospectively within 6 months after the last patient (admitted by 2025) is included; diagnostic accuracy analysis will be finished within 6 months after data collection.

Collaborators and Investigators

• Sponsor: The First Hospital of Jilin University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: December 15, 2025
• First Submitted That Met QC Criteria: December 15, 2025
• First Posted (Actual): December 29, 2025

Study Record Updates

• Last Update Posted (Actual): February 9, 2026
• Last Update Submitted That Met QC Criteria: February 5, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Severe Pneumonia; Retrospective Cohort Study; Lung CT; Infectious Pathogen Identification; Bronchoscopic Imaging
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Respiratory Tract Diseases; Lung Diseases; Pneumonia
• Other Study ID Numbers: IPID-2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

We plan to share de-identified individual participant data (IPD) that includes:

Demographic information (e.g., age, gender); Baseline clinical characteristics (e.g., disease stage, results of relevant laboratory tests); Intervention-associated data (e.g., diagnostic findings from computed tomography (CT) alone and combined with bronchoscopy); Outcome measures (the accuracy of diagnosis for severe pneumonia); Safety data (e.g., documentation of adverse events). To safeguard participant privacy, all shared data will be fully de-identified by removing direct identifiers (e.g., full name, contact details, medical record number).

• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No