The Role of Relative Determination of the Right Lung Volume by the Diaphragm Index in the Diagnosis of Chronic Obstructive Pulmonary Disease

Dorot. Medical Center for Rehabilitation and Geriatrics, Netanya, Israel

*Corresponding Author: Michael D Levin, MD, Ph.D, Dorot. Medical Center for Rehabilitation and Geriatrics, Department of Pediatric Radiology of the 1-st State Hospital, Minsk, Belarus, Dorot. Medical Center for Rehabilitation and Geriatrics, Amnon veTamar, Netanya, Israel, Tel: 972-538281393, Email: [email protected]

Received Date: February 27, 2026

Published Date: March 10, 2026

Citation: Levin MD. (2026). The Role of Relative Determination of the Right Lung Volume by the Diaphragm Index in the Diagnosis of Chronic Obstructive Pulmonary Disease. Mathews J Case Rep. 11(1):218.

Copyrights: Levin MD. © (2026).

ABSTRACT

Introduction: Chronic obstructive pulmonary disease (COPD) is defined as persistent airflow obstruction resulting from chronic bronchitis, emphysema, or both. Traditionally, spirometry had been considered the gold standard for diagnosing COPD. Modern imaging techniques show that determining lung volume makes it possible to more accurately differentiate between obstructive and restrictive causes of pulmonary insufficiency. However, all methods for determining lung volume record true lung volumes using standard values for comparison. The difficulty lies in the fact that these standards vary significantly depending on age, gender, and height. Secondly, complex engineering structures and/or mathematical programs are used to determine lung volume. Method: The relative volume of the right lung was determined on a standard plain radiograph. A horizontal isoline is drawn through the lower edge of the (D-10) thoracic vertebra, where the domes of the diaphragm are attached. The height of the right dome is defined as the vertical line in centimeters between the highest point of the dome and the isoline. It has sign (+) if it is above the isoline, or with a sign (-) if it is below. The depth of the sinus was defined as the vertical line in centimeters between the sinus and the intersection of the isoline with the lateral wall of the chest with signs + or - if it was above or below the isoline. The sum of the height of the diaphragm and the depth of the sinus (diaphragm index - DI) is an integral characteristic of the volume of the right lung. Results: This study included 66 patients aged 50–86 years. 46 of them were admitted to a medical center for rehabilitation and geriatrics with a diagnosis of COPD. In 21 of them (group 1), the lung volume was greater than normal (DI < -5), which confirmed the diagnosis of COPD. In 25 out of 46 patients (group 2), lung volume was not increased. The causes of respiratory failure in these patients included atelectasis, heart failure, and post-pulmonary embolism conditions. Twenty cases (Group 3) included patients with acute respiratory infections or post-aspiration. It was found that acute bronchitis also increases lung volume, but to a lesser extent than COPD. Conclusion: The diaphragm index (DI) is a simple, reliable, and inexpensive radiographic measure of lung volume. It enhances the diagnostic value of chest radiography by differentiating COPD from other causes of respiratory failure.

Keywords: Chronic Obstructive Pulmonary Disease, Spirometry, Computer Tomography, Chest Radiography, Diaphragm Index, Volume Lung.