MRI of the pulmonary parenchyma.

Up to now the role of lung imaging in routine diagnostic work-up of pulmonary diseases has remained rather limited. However, the well-known technical problems of lung MRI (low spatial resolution, motion artifacts, low signal-to-noise ratio of the lung parenchyma) have been reduced by recent technical advances, thus leading to a significantly improved image quality in MRI of the lungs. Compared to helical CT good results have been demonstrated using a cardiac and respiratory triggered T, weighted turbo spin echo sequence which should be included in every imaging protocol. Recent studies have proven that MRI is comparable or even better than the gold-standard helical CT regarding the staging of bronchogenic cancer and follow-up examinations of pneumonia and lung metastases. For other indications like the assessment of pulmonary nodules and the early diagnosis of pneumonia MRI has shown promising results; however these results need to be confirmed in larger patient groups. In patients with chronic infiltrative lung disease, CT scanning remains the superior imaging modality due to the inferior spatial resolution of MRI. In conclusion MRI is a reliable alternative imaging method to helical CT for many indications; in some cases it may be a promising additional examination method.