New imaging tehnique improves COPD diagnosis and treatment

New imaging tehnique improves COPD diagnosis and treatment

A team of researchers from the University of Michigan Medical School have developed a new imaging technique that improves diagnosis of COPD. The new technique, called parametric response mapping, or PRM, uses CT scans of patients with COPD and allows to distinguish different types of lung damage. Co-author Meilan Han, M.D. MS, a pulmonologist and COPDGene UM investigator, said that PRM is a step forward that allows the sub-classification of patients with COPD. In addition, he added that better understanding of the patient’s characteristics allows more targeted therapies.

COPD Diagnosis And Treatment

COPD is a chronic respiratory disease characterized by chronic bronchitis and emphysema occurring due to lung tissue damage. In other words, COPD refers to narrowed airways which means that gas exchanges do not occur as it should. Patients with COPD often suffer from dyspnea. Of course, the symptoms vary depending on the type of COPD: in those with chronic bronchitis (blue boaters),  the main symptom is cough while in those with emphysema (pink puffers),  the main symptom is dyspnea. These symptoms are due, on the one hand, to the fact that  the bronchi are filled with mucus(cough) and, on the other hand, due to destruction of septa between alveoli (dyspnea). COPD can be kept under control with drugs: bronchodilators (beta2 adrenergic receptor agonists) such as salbutamol, corticosteroids (budesonide), anticholinergic (ipratropium), theophylline etc.

COPD is most commonly associated with smoking, but there are also other factors involved, such as exposure to pollutants, etc. It must be said that COPD  is diagnosed using spirometry tests . But spirometry has several limitations because it can not distinguish between different types of lung damage that patient has. In addition, spirometry results are highly dependent on patient cooperation. Spirometry requires the patient to blow several times through a device called spirometer. Therefore, the results can sometimes be underestimated.

Diagnostic imaging methods such as CT scans, help locate the emphysema and excludes other lung diseases. PRM was originally developed to assess the response to treatment of brain tumors but researchers thought to extend the application of this technique to the lungs. Now with PRM, patients with COPD may benefit from a more precise diagnosis that carefully examines the small airways. Researchers can create a three-dimensional map of the patient’s lung tissue. This  three-dimensional map tissue reflect the extension of impaired lung tissue: red means very low lung capacity to give off the air of small airways, yellow means low capacity and green means healthy tissue. Lead author Craig Gabana, assistant professor of radiology, said that PRM is useful in evaluating COPD progression and response to treatment.