Imaging of the pulmonary hilum: a prospective comparative study in patients with lung cancer

Using magnetic resonance imaging (MRI), dynamic computed tomography (CT), and 55 degrees posterior oblique tomography, the authors prospectively evaluated the pulmonary hilum in 35 patients with lung cancer; 19 of these patients had surgical excision of ipsilateral hilar lymph nodes and formed the study group. Their results showed no significant differences between the three imaging methods in overall accuracy of hilar evaluation. Both MRI and dynamic CT were highly sensitive but relatively nonspecific for diagnosing hilar metastasis, whereas oblique tomography had fair sensitivity and specificity. The low specificity of MRI and dynamic CT was due to detection of mildly enlarged (10-16 mm) benign hilar nodes, which were present in five (26%) of 19 patients. The calculated magnetic relaxation times, T1 and T2, were not useful in distinguishing between benign and malignant enlarged hilar nodes. The authors conclude that accurate staging of the pulmonary hilum in patients with lung cancer is not currently possible using MRI, CT, or oblique tomography.