Combined diagnostic imaging of mediastinal lymphadenopathy in lung cancer

The identification and characterization of lymphadenopathies is one of the fascinating challenges of modern diagnostic imaging. At present, the real problem is the distinction between normal and pathologic signs. For twenty years, the differentiation was based on the dimensional criterion, namely a short axis < 1 cm, however it was shown to be inadequate. After an overview of the anatomy, ATS classification, the role of N factor in lung cancer (60% of N0 patients survive at 5 years) while only 20% of N2 patients survive), the new signs evidenced on CT are analyzed and interpreted. With thin section, late phase CT, a retrospective study and a perspective study were carried out on densitometric changes in lymph nodes correlated with histology findings. The role of intranodal hypodensity, peripheral rim and adipose tissue was stressed. The results of these studies were concordant with histology findings and confirmed the better accuracy in staging and the impact on survival of extranodal spread detected, based on radiologic criteria.