4DX for the Diagnosis of Constrictive Bronchiolitis

Not Applicable

Completed

• Conditions: Constrictive Bronchiolitis
• Interventions: Diagnostic Test: X-ray velocimetry analyzed by 4Dx XV Ventilation Analysis

• Registration Number: NCT04489758
• Lead Sponsor: Vanderbilt University Medical Center

Brief Summary

Constrictive bronchiolitis is an uncommon lung disease that has been described in Veterans of conflicts in Iraq and Afghanistan. Although these Veterans have evidence of constrictive bronchiolitis on lung biopsies, non-invasive tests such as pulmonary function tests (PFTs) are often normal. This study will determine whether analysis of fluoroscopy images using the 4Dx XV Ventilation Analysis software developed by 4D Medical will be able to detect constrictive bronchiolitis in Veterans better than PFTs.

Detailed Description

Constrictive (or obliterative) bronchiolitis is a rare pulmonary disease characterized by subepithelial inflammatory and fibrotic narrowing of the bronchioles on histologic analysis, which often presents with nonspecific symptoms such as progressive dyspnea on exertion and nonproductive cough over weeks to months. Constrictive bronchiolitis may be triggered by autoimmune disease, chronic allograft rejection in lung transplant recipients, graft versus host disease in stem cell transplant recipients, viral illness, or inhaled toxins. Although pulmonary function tests (PFTs) may be helpful for the diagnosis of constrictive bronchiolitis, a study performed by King and colleagues in 2009 found that many Veterans with biopsy-proven constrictive bronchiolitis had normal PFTs. Thus, for these patients, more sensitive methods of noninvasive testing are needed.

4Dx XV Ventilation Analysis is a new imaging analysis algorithm which utilizes standard fluoroscopy to quantify ventilation with sufficient fidelity to identify regional differences. Fluoroscopic images of a single tidal breath are obtained at 5 distinct angles (direct AP, +/- 36 degrees, and +/- 72 degrees). Readouts from the 4Dx XV Ventilation Analysis include absolute value of total lung ventilation, heterogeneity of lung ventilation, a frequency distribution of lung ventilation as a line plot, and a regional map of lung ventilation. In addition, an expiratory time constant (time to exhale 63% of the tidal volume), heterogeneity of the expiratory time constant, frequency distribution of expiratory time constant as a line plot, and a regional map of expiratory time constant are also calculated. Pilot studies performed by 4D Medical show data generated by the 4Dx XV Ventilation Analysis software applied to fluoroscopy is reproducible in individuals with normal lung function and the heterogeneity index increases in individuals undergoing radiation therapy.

The investigators hypothesize that the 4Dx XV Ventilation Analysis program, when applied to standard fluoroscopic images, is more sensitive for the diagnosis of constrictive bronchiolitis than PFTs in Veterans with constrictive bronchiolitis. Specific metrics that will be evaluated with the software include ventilation heterogeneity and expiratory phase constants, among other metrics. Endpoints will be compared during tidal breathing and a full exhalation to residual volume from functional residual capacity.

Basic Information
|
Recruitment & Eligibility
|
Study & Design
|
Trial Locations

Study Timeline

• Study First Submitted: 2020-07-23
• Study First Submitted QC: 2020-07-23
• Study First Posted: 2020-07-28
• Study Start: 2021-06-25
• Primary Completion: 2022-05-27
• Study Completion: 2022-05-27
• Status Verified: 2022-08
• Last Update Submitted: 2022-08-29
• Last Update Posted: 2022-08-30

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 18

Inclusion Criteria

Not provided

Read More

Exclusion Criteria

Not provided

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Constrictive Bronchiolitis	X-ray velocimetry analyzed by 4Dx XV Ventilation Analysis	Veterans with surgical lung biopsy-proven constrictive bronchiolitis
Controls	X-ray velocimetry analyzed by 4Dx XV Ventilation Analysis	Control patients with minimal smoking history and no chronic lung disease or respiratory symptoms

Primary Outcome Measures

Name	Time	Method
X-ray velocimetry results	1 month	Heterogeneity of ventilation as detected by X-ray velocimetry

Trial Locations

Locations (1)

Vanderbilt University Medical Center; 🇺🇸 Nashville, Tennessee, United States