Accuracy of computed tomography and magnetic resonance imaging in staging bronchogenic carcinoma

Sixty-three patients with non-small cell bronchogenic carcinoma were prospectively and independently assessed by computed tomography (CT) and magnetic resonance imaging (MRI) before surgery. Images were interpreted by four radiologists who had no knowledge of other imaging studies, except chest x-ray, and were blinded to surgical findings. The data were compared with pathologic and histologic findings. The accuracies of CT and MRI in determining tumor classification and assessing mediastinal and hilar lymph node metastases were compared. Sensitivity of CT in determining T factor was 78%, and specificity was 96%. The values for MRI were 84% and 96%, respectively. There was no significant difference between CT and MRI in staging tumors. MRI is more accurate than CT in diagnosing mediastinal invasion in staging superior sulcus tumors and complex tumors. There was no significant difference between the accuracies of CT and MRI in detecting mediastinal node metastases; the sensitivities were 82% and 90%, respectively, and specificities were 88% and 93%, respectively.     

Magnetic resonance imaging and67ga scan versus computed tomography in the staging and in the monitoring of mediastinal malignant lymphoma: a prospective pilot study

Purpose: To assess the potential value of magnetic resonance imaging (MRI) combined with⁶⁷Ga single-photon emission computed tomography (SPECT) versus computed tomography (CT) in the staging and in the monitoring of mediastinal malignant lymphoma. Materials and methods: Twenty-three patients, referred to our institute for the evaluation of lymphoma, underwent CT,⁶⁷Ga scan, and MRI between April 1993 and February 1996 at sequential intervals. The tests studied (MRI,^67Ga, and CT) were performed according to the following schedule: 1) before start of therapy; 2) after four courses of chemotherapy; and 3) 2, 6, 12, and 18 months after the end of treatment. Results: All patients studied at the time of diagnosis had abnormal gallium accumulation in the mediastinum as well as pathologic CT and pathologic signal intensity at MRI. Six months after the end of treatment full consistency was found between the results of MRI and SPECT, whereas during treatment and 2 months after the end of therapy MRI and⁶⁷Ga scan were not in agreement in nine patients. In the 23 patients in follow-up, in CT there were nine false-positive and three false-negative findings; in SPECT three false negatives; in MRI one false positive and one false negative. Conclusion: MRI can give morphologic information similar to CT, even superior due to multiplanarity and with major precision in the distinction between fibrosis and active disease. MRI is thus an alternative to CT. The association with SPECT allows a great diagnostic accuracy in the positive and negative predictive value.