IMAGING OF THE LUNGS USING 3HE MRI - PRELIMINARY CLINICAL-EXPERIENCE IN 18 PATIENTS WITH AND WITHOUT LUNG-DISEASE

The purpose of this study was to describe the 3He MRI findings of norm al pulmonary ventilation in healthy volunteers and to evaluate abnorma lities in patients with different lung diseases, Hyperpolarized 3He ga s (300 ml, 3 x 10(5) Pa, polarized to 35-45% by optical pumping, provi ded in special glass cells) was inhaled by 8 healthy volunteers and 10 patients with different lung diseases. Imaging was performed with a t hree-dimensional fast low-angle shot (FLASH) sequence (TR = 11.8 msec; TE = 5 msec; transmitter amplitude, 5-8 V; corresponding nip angle, < 5 degrees) in a single breath-hold (22-42 seconds). Clinical and radio logic examinations were available for correlation, The studies were pe rformed successfully in eight of eight volunteers and in 8 of 10 patie nts, The lung parenchyma of volunteers with normal ventilatory functio n exhibited rather homogeneous intermediate to high signal, whereas pa tients with chronic obstructive lung disease or bronchiectasis present ed with severe signal inhomogeneities with patchy or wedge-shaped defe cts, The mass effect of bronchogenic carcinoma, chronic empyema, lymph adenopathy, or pleural effusion caused large signal defects, represent ing the lesion and adjacent hypoventilation, the extent of which had n ot been presumed from chest x-ray or CT. 3He MRI is a promising new mo dality for the assessment of pulmonary ventilation and its abnormaliti es. Additional studies are needed to determine its potential clinical role.