Abstract
It has been reported that the margin of vascular shadows in chest roentgenograms can become ill-defined in some diseases which mainly affected perivascular connective tissues in the interstitial tissues of lung.
In addition to those changes, it can become impossible to identify whether the region of disease in the perivascular or alveolar area if nodular shadows exist in the lung fields.
This investigation was undertaken to investigate these problems by using various kinds of vascular patterns in a lung phantom of their tomographic findings.
The results were as follows;
1) It is possible to identify the vascular structure located in horizontally and tangentially if nodular shadows exist only in small amounts or not at all in the antero-posterior tomogram.
2) However, it is impossible to identify the vessels when they were placed more than 5mm apart from the section plane, due to blurring of the images, even if the vessels were horizontal
3) Tomographic vessel images which run obliquely against the section plane, can only be evaluated when they are tangential to the section plane. Also, author emphasized that the vessel length on tomographic views should be considered.
4) Increasing nodular shadows in the lung field made it more difficult to identify the site of perivascular lesions due to overlapping of these nodules.
