Lung MRI as a possible alternative to CT scan for patients with primary immune deficiencies and increased radiosensitivity.

Abstract

Patients with common variable immunodeficiency (CVID) suffer from respiratory infections leading over time to permanent lung damage. Increased radiosensitivity has been described, and clinicians should consider a risk-benefit assessment when ordering a CT scan, in that the exact level of "safe" radiation exposure is unknown. Twenty-one patients with CVID were evaluated with chest CT scan, MRI, and pulmonary function tests on the same day. MRI protocol included a T2-weighted rotating blade-like k-space covering sequence (time repetition, 2,000; echo train = 27; field of view, 400 mm; flip angle, 150; slice thickness, 5 mm) on axial and coronal planes. The bronchial and parenchymal abnormalities were compared with those identified by CT scan applying a modified Bhalla scoring system to assess bronchiectasis, bronchial wall thickening, number of bronchial generations involved, mucous plugging, consolidations, emphysema, bullae, and nodules. CT scan and MRI findings were comparable for moderate to severe degrees of bronchial and parenchymal alterations. A low concordance was found between MRI and CT scan for lower scores of bronchial abnormalities. CT scan allowed a better identification of peripheral airways abnormalities. Lung alterations in patients with higher radiation sensitivity, such as patients with CVID, might be evaluated by MRI, a radiation-free technique alternative to CT scan.