Identifying the heterogeneity of COPD by V/P SPECT: a new tool for improving the diagnosis of parenchymal defects and grading the severity of small airways disease

V/Q SPECT, using Technegas as the ventilation imaging agent, could diagnose and grade severity of COPD and also estimate preserved lung function in 94 patients. Moreover, V/Q SPECT appears to be a unique tool to reveal the heterogeneity of COPD caused by pulmonary comorbidities such as pulmonary embolism, left heart failure, lung tumor and pneumonia. The characteristics of these comorbidities suggest their significant impact in symptoms, their influence on prognosis and their response to treatment.