Search PubMedSearch

Biomedical subjects

M Buxton-Thomas

Publications and source records attributed to M Buxton-Thomas.

10 recordsLinked to original sources

Imaging secondary neuroendocrine tumours of the liver: comparison of I123 metaiodobenzylguanidine (MIBG) and In111-labelled octreotide (Octreoscan).

Functional imaging of neuroendocrine tumours with Octreoscan and I123-metaiodobenzylguanidine (MIBG) is important for assessment prior to various therapies and assessing response. The two imaging methods have not been directly compared in hepatic neuroendocrine tumours. Patients (n = 18) were studied with both imaging techniques. The sensitivity of Octreoscan was 94%, and that of MIBG 39%. No previously occult primary sites were detected. Concurrent octreotide therapy did not reduce the sensitivity of Octreoscan. Widespread bone metastases were seen in two post-liver-transplant patients using Octreoscan. Octreoscan is a sensitive means of detecting hepatic neuroendocrine tumours, and the more specific technique. MIBG has poor sensitivity, reducing its clinical utility. Therapy with I131-MIBG is likely to be applicable to relatively few patients.

3-Iodobenzylguanidine

Gamma camera purchasing.

The purchase of a new gamma camera is a major undertaking and represents a long-term commitment for most nuclear medicine departments. The purpose of tendering for gamma cameras is to assess the best match between the requirements of the clinical department and the equipment available and not necessarily to buy the 'best camera' [1-3]. After many years of drawing up tender specifications, this paper tries to outline some of the traps and pitfalls of this potentially perilous, although largely rewarding, exercise.

Gamma Cameras

201Tl scintigraphy in the assessment of patients with multi-vessel coronary disease undergoing angioplasty who have previously had a coronary bypass graft operation.

Percutaneous transluminal coronary angioplasty (PTCA) has an important therapeutic role in the treatment of coronary artery disease. The purpose of this study was to investigate the role of 201Tl scintigraphy in symptomatic patients with multi-vessel coronary artery disease undergoing angioplasty who had previously undergone coronary graft operations. 201Tl imaging was carried out in 12 patients prior to PTCA, 6 weeks and 6 months to 1 year post-PTCA. Prior to PTCA, 201Tl imaging correctly identified the site of the dominant lesion in all patients in correlation with the catheter results. Six weeks post-PTCA, seven cases who had angiographically successful angioplasty showed persistent defects on 201Tl imaging. In five of these cases, follow-up catheter showed that re-stenosis had occurred. Six months to 1 year post-PTCA, 201Tl imaging was found to have good correlation (11 out of 12 patients) with the catheter results. The results suggest that 201Tl imaging is useful in the management of patients with multi-vessel disease undergoing angioplasty.

Aged

The current cost of nuclear medicine.

In the light of the control of expenditure and changes in radiopharmaceutical costs, changes in study protocols, new investigation procedures and inappropriate placing in Korner categories, the BNMS Council set up a working party to derive an agreed set of costings for Nuclear Medicine techniques. Using data from three hospitals with additional information from another nine, we have agreed the 1988 cost of individual nuclear medicine procedures in the UK. These figures include staffing (radiopharmacy, nursing, physics, medical including consultant), radiopharmaceuticals and other consumables, indirect costs (secretarial, administrative, portering), variable overheads (service contracts, stationery) and fixed overheads (rates, lighting, heating, building and engineering). Capital costs, equipment and buildings were not included. Because figures include salary and overhead costs they are difficult to compare with the majority of other previous nuclear medicine costings, apart from Bretland et al., or with data for other imaging modalities. Comparison of these costings with Korner schedules shows marked overlap between the Korner groups. Such groups therefore form a poor method of costing nuclear medicine procedures. We propose alternative groupings.

Costs and Cost Analysis

Abdominal scintigraphy with 99Tcm-labelled red cells in the detection of rebleeding from peptic ulcers.

The technique of 99Tcm-labelled red cell scintigraphy as a means of detecting rebleeding was investigated in 33 patients with bleeding peptic ulcers. Scintigrams were performed twice during the 24 h period succeeding diagnostic endoscopy. There was scintigraphic evidence of rebleeding in 23 patients but this was clinically manifest in 14 patients only. Thirteen of the 14 patients with clinical rebleeding had positive scintigrams while only in one patient with clinical rebleeding was the scintigram negative (P less than 0.05). These results show that rebleeding is common and often clinically inapparent during the first 24 h following gastroscopy but that in the absence of scintigraphic rebleeding serious clinical rebleeding is unlikely to occur.

Adult

Intrahepatic bile duct dilatation shown by computed tomography--predilection for the left lobe?

Dilated biliary duct radicles were most obvious within the left lobe of the liver in 30 out of 42 patients with obstructive jaundice in whom intrahepatic duct dilatation was satisfactorily demonstrated by computed tomography. In 19 of these 30 patients the level of obstruction was at the lower end of the common bile duct. Recognition of this finding may prevent the erroneous diagnosis of intrahepatic or multiple obstructing lesions.

Cholestasis, Intrahepatic

Cryptogenic fibrosing alveolitis: pattern of disease in the lung.

The distribution of disease has been studied in 10 patients with histologically confirmed cryptogenic fibrosing alveolitis by means of computed tomography of the lungs, gallium 67 uptake scintigraphy, and ventilation and perfusion scintigraphy. The findings of computed tomography and scintigraphy showed no correlation with the UICC/Cincinnati grades of the plain chest radiographs, even when these were supplemented with information from lateral and oblique chest films. Computed tomography showed subpleural shadowing in every patient except one who had responded well to corticosteroid treatment. Subpleural shadowing was commoner in the inferior and posterior parts of the lung lobes and was commonest in the posterior lower subpleural areas. The central lung showed three types of change--firstly, a dense shadowing, which was sometimes associated with much increased gallium uptake; secondly, dilated smaller airways with small bullae, suggesting airway disease; and, thirdly, gross bullous change.

Humans

Adult idiopathic pulmonary haemosiderosis: a comparison of lung function changes and the distribution of pulmonary disease in patients with and without coeliac disease.

Seven patients with idiopathic pulmonary haemosiderosis were investigated with chest radiographs, pulmonary function tests, computed axial tomograms, and isotope ventilation and perfusion scans. Three of the patients had coeliac disease (CD) and a fourth an abnormal small bowel mucosa under the dissecting microscope which was normal histologically. Five patients showed airflow limitation with a low transfer coefficient. Three of these had air trapping, two of whom had hyperinflation of the lungs, and the third a total lung capacity at the upper limit of normal. Two patients showed a central distribution of radiographic opacities, and the other five had changes throughout the lung fields. The presence or absence of CD showed no relationship to these findings.

Adult

Clearance of inhaled 99mTc DTPA from regions of the lung recently affected by pulmonary embolus.

Pulmonary emboli lead to regional limitation of pulmonary artery perfusion, often without affecting distribution of ventilation. We have studied the effect of this regional reduction of pulmonary artery perfusion on the integrity of epithelium of alveoli (and possibly bronchioli). Integrity of alveolar epithelium was assessed by measuring regional rates of clearance from lung to blood of an inhaled aerosol of a small molecular weight solute, 99mTc DTPA (technetium-99m diethylene-triamine-pentaacetate). Ten patients with pulmonary emboli were studied, where the diagnosis was made from 'mismatching' seen on ventilation (V) and perfusion (Q) lung scintigraphy. Rates of clearance of DTPA in regions with normal V/Q ratios were compared with embolized regions with high V/Q ratios. Clearance rates were increased in embolized regions (V/Q ratio greater than 1): 2.59 +/- (SD) 0.89% X min-1, compared with normal regions (V/Q ratio less than 1): mean 1.39 +/- 0.60% X min-1 (p less than 0.01). In repeat studies in nine patients (one died), after intervals between 2 and 12 weeks, the V/Q ratio of previously embolized regions decreased towards unity in all nine patients, suggesting resolution. The differences in clearance rates for DTPA between normal and embolized regions decreased in association with this return towards normal of V/Q ratios. We surmise that reduction in pulmonary artery perfusion which occurs in pulmonary embolic disease alters the integrity of the alveolar (and possibly bronchiolar) epithelium. This effect is largely reversible, recovering with return of pulmonary artery perfusion.

Aerosols