Congenital anomalies of the lungs in adults: MR diagnosis.

Over an 18-month period, 11 adults with congenital pulmonary anomalies within the sequestration spectrum, identified either surgically or radiographically by CT and/or angiography, were evaluated with MR. These included seven patients with bronchogenic cysts, two with intralobar pulmonary sequestrations, one with scimitar syndrome, and one with bronchial atresia. In each case, MR showed at least some findings indicative of the correct diagnosis. MR proved especially effective in the detection of abnormal fluid collections (nine cases) and the identification of anomalous vessels (three cases). Fluid collections were easily identified in all cases, including four cases with high-density collections on CT (two with bronchogenic cysts and two with intralobar pulmonary sequestration), especially when single-level, multiecho T2-weighted sequences were obtained. Calculated T2 values ranged from 78 to 439 msec (average, 223 +/- 123 msec). Although T2 values were statistically significant for differentiating fluid from muscle (p = .0012) and fat (p = .0046), they were not sufficiently specific to allow precise fluid characterization. Significant limitations were also apparent, such as an inability to detect alterations in the parenchymal architecture of the lungs (three cases) or intrapulmonary vascularity (one case). Despite this, we conclude that MR may be of considerable value in the assessment of congenital pulmonary anomalies and in select cases obviate more invasive diagnostic procedures.