Measurement of pulmonary perfusion using a digitised ECG-triggered gamma ray absorption technique

AN ECG-triggered multisweep method for the collection of low-energy gamma ray absorption data in normal and cancerous tissue has been developed, resulting in digital perfusion curves with reliable statistics. The small intensity modulation ( approximately equal to 1.2%) due to lung perfusion is detected and separated from the much stronger intensity variations caused by ventilation in a satisfactory way. During this non-invasive test the patient is supine and breathes smoothly.