I. Kelsey Fry

Pre-operative computed tomography of carcinoma of the rectum

Fifty-two patients with carcinoma of the rectum under-went computed tomography (CT) in the immediate preoperative period. CT was used in order to assess extrarectal tumour spread. The resected specimen was staged by the pathologist who subdivided spread in continuity beyond the bowel wall into slight, moderate or extensive. In 21 out of 23 patients with no or slight extrarectal local spread CT showed normal perirectal fat. Extrarectal spread was demonstrated by CT in eight of the nine patients found to have extensive local spread. This was seen to be circumferential in the only two patients with inoperable tumors. CT identified discrete nodal enlargement in seven of the 18 patients with histologically involved lymph nodes. CT may help the less experienced surgeon, especially when he is not confident of his findings at digital examination. CT allows assessment of high rectal tumours which cannot be examined digitally. It may play a role where a tumour with extensive local spread is clinically suspected and confirmation is needed before preoperative radiotherapy is given.

The appearances on computed tomography after abdomino- perineal resection for carcinoma of the rectum: a comparison between the normal appearances and those of recurrence

Computed tomography is well recognised as a means of showing recurrent tumour in patients who have undergone abdominoperineal resection for carcinoma of the rectum. The appearance of recurrent tumour has to be distinguished from that of normal postoperative fibrous tissue. To define the normal postoperative appearances CT was carried out on 15 patients at various intervals up to 18 months after the operation. All the patients were clinically free of recurrence at the time of the scan and for at least six months afterwards. The appearances were compared with those in 19 patients who had local recurrence at the time of scanning. The normal appearances are outlined, pitfalls in diagnosis are described and points of differentiation between the normal appearance and recurrent tumour are discussed.

Computerised tomographic (CT) abdominal scanning in Hodgkin's disease

Thirty-nine patients with Hodgkins disease (HD) with little or no clinical evidence of abdominal disease were investigated by abdominal CT scanning. The results were compared with those of bipedal lymphography and laparotomy and splenectomy. In the assessment of para-aortic lymph nodes, CT scanning and lymphography were of equal efficacy in determining the presence or absence of disease (87 and 79% respectively). Although CT scan could occasionally demonstrate disease in nodes in areas other than the retroperitoneum, its value was limited by its inability to detect involvement of nodes which were not significantly enlarged. CT assessment of splenic HD was unreliable, focal deposits being detected in only one of the 11 spleens involved. In this selected group of patients, CT scan had little advantage over lymphography in the description of disease extent. However, CT scan would appear to be the investigation of choice in patients with suspected abdominal relapse because of the more frequent presence of disease in sites not seen on lymphography. When treatment decisions are dependent on accurate knowledge of distribution of disease, CT scanning cannot yet effectively replace staging laparotomy and splenectomy as the means of achieving this information.

HIGH-DOSE EXCRETION UROGRAPHY IN OLIGURIC RENAL FAILURE

Abstract High-dose excretion urography was carried out in twenty-one patients with oliguric renal failure. In all patients the presence or absence of extrarenal obstruction was correctly diagnosed radiologically. No adverse reactions or toxic effects were observed.

COMPUTED TOMOGRAPHY IN PATIENTS WITH AN ABDOMINAL MASS: EFFECTIVE AND EFFICIENT?: A Controlled Trial

In 28 of 53 patients with a palpable abdominal mass computed tomography (CT) was used as the initial imaging technique, and conventional imaging was used in the remaining 25 patients. The diagnosis was established more quickly in the CT group, and the period of inpatient investigation was shorter. The cost of imaging investigations was higher for the CT group, but this difference was small when compared with the difference in cost of inpatient stay. CT seems accurate in the investigation of a palpable abdominal mass and particularly useful in excluding a pathological cause. The need for the latter is emphasised by the fact that no lesion could be found in 23 of the 53 patients.

Prevalence of lung nodules on computed tomography of patients without known malignant disease

Abstract The prevalence of lung nodules on computed tomography (CT) of the chest was determined in 100 patients with normal lungs on chest radiography, and no known evidence of malignant disease. No nodule was identified which could not be seen as a calcified lesion on the chest radiograph. This suggests that uncalcified lung nodules demonstrable by CT scanning alone are rare in the general population and that the finding of such a nodule in a patient known to have malignant disease should be regarded as evidence of a metastasis.

The effect of DDAVP on intravenous urography

The possible role of an antidiuretic hormone analogue, DDAVP (1 deamino-8-D-arginine vasopressin), in intravenous urography has been studied. The minimum effective dose of intravenous DDAVP in normal hydrated subjects was shown to be 2 ng/kg. During intravenous urography in fluid restricted subjects, a dose of 1 microgram DDAVP was necessary to reduce significantly the urine flow rate after contrast medium injection. Although the mean pyelographic score after DDAVP was increased, the differences observed were not statistically significant. The possible reasons for this finding are discussed.

Radiological signs of ulcerative colitis and Crohn's disease of the colon

The films of single contrast barium enema examinations of 65 patients with either Crohns disease or ulcerative colitis were studied in order to determine the accuracy of the various radiological signs in differentiating between the 2 conditions. Clearly defined signs relating to the distribution of the disease, the symmetry or asymmetry of the lesion, alterations in the mucosal and haustral pattern and complications were assessed. Only patients in whom the diagnosis was beyond doubt were selected for the survey. All the patients with ulcerative colitis and the majority of those with Crohns disease had colectomies and were therefore severe examples of the disease. Some radiological signs occurred with equal frequency in both groups of patients, while others occurred far more frequently or exclusively in the one condition compared with the other. Discontinuity, asymmetrical involvement and a right sided distribution appear to be characteristic of Crohns disease as do cobblestones, disorganised folds and deep ulcers. Strictures and fistulae occurred exclusively in Crohns disease. The characteristic features of ulcerative colitis were a smooth contour, pseudo-polyps, hazy longitudinal folds and mucosal effacement.

The value of aortography in the diagnosis of phaeochromocytoma

The authors describe four phaeochromocytomas which were not opacified during the course of technically satisfactory aortograms but which appeared highly vascular histologically. The role of aortography is discussed and it is concluded that despite the above findings, it is the radiological examination of first choice. It may have to be supplemented by presacral pneumography or venous sampling. Possible causes for failure of tumour opacification during aortography are discussed.

The use of the right decubitus position in computed tomography of the liver and pancreas

Sixty patients underwent computed tomography (CT) with a 20 s scanner of the upper abdomen in the supine and right decubitus positions. The images of the liver were compared. The scores for the hepatic image were better when the patient was in the right decubitus position. The scores for the image of the pancreatic head were about the same in the two positions but improvement occurred in the right decubitus position in nearly half the patients. Scores for the other parts of the pancreas and for the pancreas as a whole were usually worse when in the right decubitus position although improvement did sometimes occur. Scanning in the right decubitus position has been demonstrated to be of value in reducing artefact shadows in the hepatic image and may on occasions improve the quality of the pancreatic image. Accordingly scanning in the right decubitus position is a useful aid when supine views have given poor results or when the presence of a lesion is equivocal.