Quantifying normal lung in pulmonary fibrosis: CT analysis and correlation with %DLCO

Area of Science:

• Radiology
• Pulmonary Medicine
• Quantitative Imaging

Background:

• Chest CT scans are standard for monitoring pulmonary fibrosis progression.
• A lack of standardized quantitative assessment hinders accurate disease severity reporting.
• Developing a grading system can enhance radiologist-clinician communication.

Purpose of the Study:

• To develop and validate a quantitative scoring system for assessing usual interstitial pneumonitis (UIP) severity on HRCT scans.
• To evaluate the correlation between the proposed CT scoring system and pulmonary function tests.

Main Methods:

• Retrospective analysis of 96 patients with UIP on HRCT scans.
• A radiologic scoring system assessed the percentage of normal lung per lobe (0-20 scale).
• Spearman correlation analyzed the relationship between CT score and percent diffusing capacity of the lungs for carbon monoxide (DLCO).

Main Results:

• The CT scoring system ranged from 4 to 18 (average 10.9).
• Percent DLCO ranged from 17% to 88% (average 44.5%).
• A significant positive correlation (r=0.622, P < 0.001) was found between CT score and percent DLCO.

Conclusions:

• The developed scoring system provides a quantitative measure of normal lung on chest CT for UIP patients.
• This quantitative measure significantly correlates with percent DLCO, indicating its utility in assessing disease severity.
• The system shows promise for enhancing the information provided by radiologists to clinicians.