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Computerised tomography produces an excellent image of the liver. The author discusses the relevant technical factors such as the use of window levels and window widths, tissue attenuation values and filtering. The importance of the applied anatomy and the use of contrast agents are discussed and then the findings on computed tomography in clinical practice are presented. The lesions that can be visualised include cysts, abscesses, primary tumours, metastases, fatty liver, subphrenic abscess, dilated bile ducts and cholelithiasis as well as surrounding ascites. These appearances are described and illustrated.

Thirty-three cases with malignant disease due mainly to lymphoma and testicular tumours were evaluated by computerised tomography (CT) scanning on the EMI general purpose scanner. In many cases there were either more lymph nodes demonstrated than on lymphography or more disease shown in bone or the thorax than was suspected. CT scanning is particularly valuable in showing mesenteric, retrosternal, axillary and para-aortic lymph node enlargement. Bone, liver and pulmonary metastases were shown when not demonstrated by other methods as well as showing the extent of recurrence of malignant disease. In testicular tumours metastatic spread to paravertebral soft tissues behind the diaphragm was clearly demonstrated. This cannot be seen on lymphography. CT scanning appears to be the most accurate method to date of showing the extent of malignant disease, particularly in cases of lymphoma and testicular tumours.

Clinical and biochemical information together with good spatial resolution by CT offers final assessment of certain adrenal masses even when their size is 1-2 cm. Moderate sized tumours, i.e. up to 8 cm in size are amenable to accurate definition by CT. In some situations it is the final diagnostic modality of adrenal tumours. Tumour recurrence or deposition in the adrenal area is accurately followed by performing sequential scans. Extension and dissemination of neoplasms beyond the confines of the suprarenal can now be defined more readily by CT. Lipid and blood content of adrenal tumours gives low density areas which can mistakenly be assessed as 'cystic' lesions. Large tumours in the area frequently require additional clinical, biochemical and radiological investigation before diagnostic solution is achieved.

A combined radiological and autopsy study of pulmonary oedema enables recognition of oedema lines other than Kerley 'A', 'B' and C lines. These have been designated 'D' lines. At least three varieties have been noted: (i) thick, long often angular lines seen mainly anteriorly overlying the heart shadow on the lateral film. These may also appear as horizontal or vertical band shadows, on the frontal view. (ii) Short and straight lines, occurring basally and often slightly thicker at the pleural surface, which on autopsy lung radiographs are associated with puckering of the pleura. They have also been recognised on lateral films where they resemble the pleural end of a fissure but have been seen in positions where fissures do not mormally occur, or in addition to the normal fissure. (iii) A subpleural reticular pattern surrounding spaces 1-2 cm in diameter. This has been noted only on autopsy-inflated lungs and not detected on in vivo chest radiographs. The long 'D' lines or D(i) lines occur in areas where 'B' lines are inconspicuous or absent and vice versa. Whereas 'B' lines are most prominent in areas of macroscopic alveolar pulmonary oedema, D(i) lines occur where macroscopic alveolar pulmonary oedema is often inconspicuous. The recognition that lines other than 'A', B and 'C' occur in case of pulmonary oedema greatly assists in the interpretation and diagnosis of the shadows on chest radiographs associated with pulmonary oedema.

Attention is drawn to the signs of asbestosis on computed axial tomography and comparison made with findings in conventional radiology in 36 patients. CT was found to be significantly more sensitive in the detection of both pleural and parenchymal disease apart from thickened fissures. A possible sign of early mesothelioma is mentioned and an encasing variety of pleural thickening described. Perfusion changes which may represent a 'pre-radiological' interstitial fibrosis are discussed.