The purpose of this study was to describe the 3He MRI findings of normal pulmonary ventilation in healthy volunteers and to evaluate abnormalities in patients with different lung diseases. Hyperpolarized 3He gas (300 ml, 3 x 10(5) Pa, polarized to 35-45% by optical pumping, provided in special glass cells) was inhaled by 8 healthy volunteers and 10 patients with different lung diseases. Imaging was performed with a three-dimensional fast low-angle shot (FLASH) sequence (TR = 11.8 msec; TE = 5 msec; transmitter amplitude, 5-8 V; corresponding flip angle, < 5 degrees) in a single breath-hold (22-42 seconds). Clinical and radiological examinations were available for correlation. The studies were performed successfully in eight of eight volunteers and in 8 of 10 patients. The lung parenchyma of volunteers with normal ventilatory function exhibited rather homogeneous intermediate to high signal, whereas patients with chronic obstructive lung disease or bronchiectasis presented with severe signal inhomogeneities with patchy or wedge-shaped defects. The mass effect of bronchogenic carcinoma, chronic empyema, lymphadenopathy, or pleural effusion caused large signal defects, representing the lesion and adjacent hypoventilation, the extent of which had not been presumed from chest x-ray or CT. 3He MRI is a promising new modality for the assessment of pulmonary ventilation and its abnormalities. Additional studies are needed to determine its potential clinical role.

Adult↗

PubMedDate not supplied

[Pulmonary sequelae of long-term ventilation of very low birth weight premature infants. Results of a follow-up study of 6-to-9-year-old children].

Fifty six children with a birth weight of less than 1500 g and gestational age less than 34 weeks were studied at a mean age of 7.7 years. All had required mechanical ventilation, 36 suffered from hyaline membrane disease, 17 from atelectasis and three from pneumonia. Of these patients 37 developed broncho-pulmonary dysplasia (BPD). The study included skin prick test, measurement of ciliary beat frequency, chest X-ray, whole-body plethysmography and histamine challenge. Eight patients suffered from recurrent pulmonary infections up to the age of 4 years. Eleven children had a positive skin prick test. Three suffered from allergic asthma and six from hay-fever. The family history of atopy in these premature infants was no different from that of the general population. Ciliary beat frequency was normal in all cases (frequency: 11.8 +/- 1.8 Hz). In 34 patients X-rays showed minimal changes (peribronchial thickening n = 6, mild emphysema n = 28). Pulmonary function was normal except for an increase of thoracic gas volume which was correlated to grade of BPD according to Northway. There was a significant correlation between oxygen-score and radiological stage of BPD (r = 0.7). Histamine challenge showed hyperresponsiveness in 53% of the children. Eight patients showed a threshold similar of mild asthma (less than 1000 micrograms histamine per ml). The degree of airway hyperreactivity was correlated to the grade of BPD (r = 0.7; p less than 0.01) and the oxygen-score (r = -0.63; p less than 0.05). The oxygen-score may be considered a predictor of hyperresponsiveness and pulmonary outcome in later childhood.

Bronchial Hyperreactivity↗