HRCT studies of lung anatomy

An accurate definition of lung anatomy is the first, necessary step to obtain an accurate and early diagnosis of diffuse and focal lung disease with HRCT. Secondary lobules are visible with conventional CT and HRCT as polygonal portions of lung parenchyma, surrounded by thin and incomplete septa and centred by a dense dot; acini are sometimes visible as rounded structures with a central dot. Morphological definition of these structures in normal subjects will greatly help in characterizing early signs of parenchymal disease.