[Analysis of mediastinal lymphadenopathy in the right paratracheal area and the pretracheal retrocaval space by tomography with a compensating filter--diagnostic significance of mediastinal reflection].

Findings of mediastinal reflection tomography with a compensating filter (Tomo) and its diagnostic significance for mediastinal lymphadenopathy were compared with those of computed tomography (CT) in 140 patients. The nodes were of normal size in 88 patients and enlarged (short transverse diameter on CT greater than or equal to 10 mm) in 52. With Tomo, the following findings had high sensitivity and a high positive predictive value (PPV): Irregularly widened (greater than or equal to 10 mm) right paratracheal stripe (RPS), irregular mediastinal reflection on the plane 1-2 cm in front of the plane of the trachea, bulge in configuration of the superior vena cava (SVC) exclusive of the area near the configuration of shadow thought to be the azygos arch (azygos arch), disappearance of the azygos arch, enlargement of the azygos arch, irregular margin of the upper-lateral portion of the azygos arch and increase in size of the more anterior part of the azygos arch, which is of homogeneous density. A high PPV but low sensitivity were noted for displacement or deformity of the trachea and/or the right main bronchus. High sensitivity but a low PPV were noted for disappearance of RPS and bulge in configuration of the SVC near the azygos arch. When the 7 findings with high sensitivity and a high PPV were combined, sensitivity, specificity and accuracy of Tomo were 84.6%, 96.6%, 92.1%, respectively.