Showing papers in "British Journal of Radiology in 1973"
TL;DR: A technique in which X-ray transmission readings are taken through the head at a multitude of angles: from these data, absorption values of the material contained within the head are calculated on a computer and presented as a series of pictures of slices of the cranium.
Abstract: This article describes a technique in which X-ray transmission readings are taken through the head at a multitude of angles: from these data, absorption values of the material contained within the head are calculated on a computer and presented as a series of pictures of slices of the cranium. The system is approximately 100 times more sensitive than conventional X-ray systems to such an extent that variations in soft tissues of nearly similar density can be displayed.
3,420 citations
TL;DR: A new and fundamentally different X-ray method is described, in which the cranium is scanned in successive layers by a narrow beam of X rays, in such a way that the transmission of the X-rays across a particular layer can be measured, and by means of a computer, used to construct a picture of the internal structure.
Abstract: A new and fundamentally different X-ray method is described. The cranium is scanned in successive layers by a narrow beam of X rays, in such a way that the transmission of the X-ray photons across a particular layer can be measured, and by means of a computer, used to construct a picture of the internal structure. Employing a suitably designed scanning gantry, a continuously operating X-ray tube, and a narrow collimated X-ray beam, the transmissions of X-ray photons across a slice of tissue may be measured by a system of crystal detectors in such a way that 28,800 readings are obtained. These form the basis of 28,000 simultaneous equations which are solved by a computer. The solutions are transformed into absorption coefficients and by means of a suitable algorithm related to their correct cells in a matrix of chosen size. The results are stored, computed, and then made available from a magnetic disc to construct a picture on a CRT. The numerical results are available from a print-out. The examin...
737 citations
TL;DR: The purpose of this paper is to introduce a set of tables which are simple to use and general in application, and which help to ensure correct interpretation of the basic NSD concepts.
Abstract: The use of the NSD concept in practical radiotherapy is simplified by the introduction of time, dose, and fractionation (TDF) factors, which are proportional to partial tolerances, but are not dependent upon any specific NSD value. Detailed examples are given of the utilization of TDF factor tables, which are simple to use, general in application, and which help to ensure the correct interpretation of the basic NSD concepts. Computers, slide-rules, or even log tables, are not required. The concept of nominal standard dose (NSD), introduced by Ellis (1967), has achieved widespread acceptance because, in spite of its obvious limitations, it enables radiotherapists to compare and contrast treatment regimes which differ in time, dose, and fractionation patterns. In a recent survey (Orton, 1972), a number of experts, chosen because they had been authors of papers on this subject, were asked to solve a problem involving a comparison of different radiotherapy regimes. The Ellis NSD concept was misused by more than half of the experts who attempted to solve the problem by this method. This resulted in dose errors ranging from +5 to +1 9 per cent with an average of +1 1 per cent. Evidently the practical application of the idea is not entirely understood and some simplification is desirable. The purpose of this paper is to introduce a set of tables which are simple to use and general in application, and which help to ensure correct interpretation of the basic NSD concepts. NOMINAL STANDARD DOSE From a consideration of iso-effect relationships in clinical radiotherapy, Ellis (1967) proposed that the tolerance dose for normal tissues (D rads) could be related to the overall treatment time {T days) and the number of fractions (N), by the expression:
527 citations
TL;DR: The percentage of controls of very large, poorly vascularized tumour masses irradiated with long treatment times compared with shorter treatment times suggests that reoxygenation may be a fa...
Abstract: Optimally, the total radiation dose, over-all treatment time, and fractionation should be individualized for every tumour on the basis of histology, the number of malignant cells, the percentage of anoxic cells, and the kinetics of that particular tumour. The histological variety within the epithelial tumours does not affect radiosensitivity. Dose-response curves obtained clinically are shown for subclinical disease in the lymphatic areas. Correlation is attempted between the volume of cancer and the doses necessary to obtain a high percentage of controls. It is shown that, depending upon the anatomical site and the clinical variety of the cancer, the doses and treatment times may be different. Reoxygenation during treatment has been considered necessary to explain the control of human cancers by irradiation. The percentage of controls of very large, poorly vascularized tumour masses irradiated with long treatment times compared with shorter treatment times suggests that reoxygenation may be a fa...
323 citations
263 citations
TL;DR: The skin reaction on the feet of albino mice has been used to investigate the relative effects of repopulation and repair of sublethal injury at various stages during a course of “daily” 300 rad fractions to show that with increasing time after a priming dose of 1,000 rads, additional dose is needed to produce a given skin reaction.
Abstract: The skin reaction on the feet of albino mice has been used to investigate the relative effects of repopulation and repair of sublethal injury at various stages during a course of “daily” 300 rad fractions. Previous two-dose experiments have shown that with increasing time after a priming dose of 1,000 rads, additional dose is needed to produce a given skin reaction. 500 rads were required after the first 24 hours, whereas only 30 rads per day were needed to counteract the subsequent repopulation. In the present series the average dose increment that was required between 4 or 9 daily fractions was almost 200 rads per interval, and was not attributable to repopulation. Between the 9th and 14th fractions this average dose increment increased because of a contribution from an increased rate of repopulation. After 4 fractions there was no measurable repopulation for two weeks. After 9 fractions approximately 50 rads per day were needed to counteract repopulation. After 14 fractions approximately 130 r...
244 citations
TL;DR: In a small area that was depleted of blood vessels by freezing, vascular proliferation was induced by the application of a stimulus employing uric acid and lithium lactate, and the depleted area becomes increasingly re-vascularized in 12 days, while in the irradiated preparations there is a paucity of vessels, the degree of reduction depending on the dose of radiation.
Abstract: Starting with a subcutaneous air pouch in the rat, a system was developed in which a thin sheet of connecting tissue was partially separated from its surroundings. In a small area that was depleted of blood vessels by freezing, vascular proliferation was induced by the application of a stimulus employing uric acid and lithium lactate. In unirradiated preparations, the depleted area becomes increasingly re-vascularized in 12 days, while in the irradiated preparations there is a paucity of vessels, the degree of reduction depending on the dose of radiation. As a quantitative indication of the “vascular index” the local amount of an intravenously injected tracer was determined. The tracer substance is a fluorescent dye, and quantification was performed by means of a microfluoro-meter. The “vascular index”, as measured by means of microfluorometry, is probably closest to the vascular silhouette. The “survival curve” derived in this way shows a D0 value of about 170 rads, a N value of about 7, and a D...
155 citations
TL;DR: The drug concentration reaching the hypoxic cells under study approximates that required for sensitization of mammalian cells in vitro.
Abstract: Several drugs of high electron affinity have been identified which sensitize cells in vitro (Adams and Cooke, 1969; Adams et al., 1971; Reuvers, Chapman and Borsa, 1972). However, their in vivo use has been limited (Hornsey, Hedges and Bryant, 1968; Denekamp and Michael, 1972) and the interpretation of the results complicated by a lack of relevant toxicological and pharmacological data. It is important to know that the drug concentration reaching the hypoxic cells under study approximates that required for sensitization of mammalian cells in vitro.
111 citations
TL;DR: This observation indicates that even when the histological nature of the tumour may suggest an unfavourable response, a trial of irradiation may be rewarding, and poorly understood factors which influence the outcome, and the sometimes unpredictable biological behaviour of certain tumours should be considered when evaluating such patients for radiation therapy.
Abstract: The preceding presentation is believed to be the first reported case of abscopal effect observed in a patient with papillary adenocarcinoma. This observation indicates that even when the histological nature of the tumour may suggest an unfavourable response, a trial of irradiation may be rewarding. Poorly understood factors which influence the outcome, and the sometimes unpredictable biological behaviour of certain tumours should be considered when evaluating such patients for radiation therapy. To do otherwise could lead one to deny treatment to patients who might have been benefited by this therapeutic modality.
111 citations
TL;DR: Measurements show that the exposure from a series of complete transverse axial scans varies between 1·0 and 2·5 R over the cranium, and estimates indicate that the integral dose from a single complete scan is likely to be less than that from asingle skull X ray.
Abstract: Measurements have been made on the computerized transverse axial scanning equipment to estimate the output of the X-ray generator, to investigate the radiation field in the X-ray room and to estimate dose to the patient. Isodose curves are shown for the total radiation field from the machine, for that fraction of the field which is due to tube housing leakage and for the fraction due to scatter from the main beam. Measurements in a simple head phantom, and subsequent calculations, showed that the exposure from a series of complete transverse axial scans varies between 1·0 and 2·5 R over the cranium. Estimates indicate that the integral dose from a single complete scan is likely to be less than that from a single skull X ray. Gonad dose is considerably less than 0·1 mrad for each complete scan.
105 citations
TL;DR: This is a report of osteoporosis and vertebral compression fractures in a 15-year-old boy who had received large doses of heparin for pulmonary venoocclusive disease for a period of approximately one year (Liu and Sackler, 1972).
Abstract: This is a report of osteoporosis and vertebral compression fractures in a 15-year-old boy who had received large doses of heparin for pulmonary venoocclusive disease for a period of approximately one year (Liu and Sackler, 1972). Hyperparathyroidism and other causes of osteoporosis had been excluded clinically and chemically. To our knowledge this is the first recorded case of heparin-induced osteoporosis in the world radiological literature and the first paediatric case of heparin-induced osteoporosis to be found in the English literature. A 15-year-old black male was admitted to the Brooklyn-Cumberland Medical Center for a third time because of recurrent attacks of exertional dyspnoea. His illness could be traced back for about two to three years. He admitted to periodic ingestion of fair amounts of powdered household cleansers. Nothing else in the past history was remarkable. On admission he was found clinically and radiographically to be in pulmonary oedema. During a five-month hospital stay he contin...
TL;DR: Various nitrofuran derivatives have been tested with Chinese hamster cells growing in vitro to determine their toxicity and radiosensitizing effectiveness and high water solubility appears to be an important property for radiosensitizers to be used in animal tumour studies.
Abstract: Various nitrofuran derivatives have been tested with Chinese hamster cells growing in vitro to determine their toxicity and radiosensitizing effectiveness. All nitrofurans tested displayed a greater radiosensitizing potential than p-nitroacetophenone for hypoxic cells at concentrations producing no acute toxicity. The most effective compound tested to date is nifuraldezone which at 250 μm in complete medium gives the same extent of radiosensitization (ER∼2·85) as oxygen in air-saturated medium. Additional nitroheterocyclic compounds in current clinical usage have also been characterized. The chemical and pharmacological properties of the various compounds are discussed in relation to their application in animal tumour studies. High water solubility appears to be an important property for radiosensitizers to be used in animal tumour studies. A positive demonstration of radiosensitization in vivo with nitroheterocyclic drugs will depend upon whether or not a sensitizing concentration of the drugs c...
TL;DR: Localized irradiation of the lungs prior to cell injection was found to increase the number of lung colonies arising from the injection of a given number of tumour cells.
Abstract: Intravenous injection of KHT sarcoma cells into syngeneic C3H mice produces tumour nodules or colonies the number of which is directly proportional to the number of viable cells injected. Localized irradiation of the lungs prior to cell injection was found to increase the number of lung colonies arising from the injection of a given number of tumour cells. This increase was (a) dose-dependent, (b) transitory in nature, and (c) resulted from a reduced clearance of viable tumour cells from the capillaries of the lungs.
TL;DR: The construction and operation of the Aberdeen Section Scanner (ASS) is described, a dual headed device which can perform conventional rectilinear scans and the more recently developed section or tomographic scans.
Abstract: The authors describe the construction and operation of the Aberdeen Section Scanner (ASS) with a few clinical examples. The scanner is a dual headed device which can perform conventional rectilinear scans and the more recently developed section or tomographic scans. A punched paper-tape output from both heads is incorporated in the system so that count and position information may be fed into a PDP 81 computer enabling subsequent image processing and display. The same computer and display unit are optionally “on-line” to a Nuclear Enterprises gamma camera. The link to the ASS means that the advantages of computerized image processing are available for scans carried out with the new rectilinear scanner. Various design features are discussed together with the storage and display facilities. The routine operation of the scanner and the initial clinical results are also described.
TL;DR: This report deals with an iatrogenic renal arteriovenous fistula that was accompanied by massive haematuria, and was successfully treated by catheter embolization of the feeding artery.
Abstract: Percutaneous renal biopsy is now accepted as a useful tool for the investigation of diffuse renal disease. A possible resultant mishap is the formation of an arteriovenous fistula, a complication that is usually asymptomatic and self-limiting (Bennet and Wiener, 1965). This report deals with an iatrogenic renal arteriovenous fistula that was accompanied by massive haematuria, and was successfully treated by catheter embolization of the feeding artery. A 50-year-old woman had presented two years previously with fever, skin rash, pleural effusion, arthritis, hepatosplenomegaly, and an abnormal urinary sediment. Investigation failed to confirm the diagnosis of collagen disease; however, the patient partially improved on Prednisone and Chloroquine. Her blood pressure was always normal (110/70).
TL;DR: The appearance of tuberculosis of the gastro-intestinal tract radiologically depends on the presence of ulceration, fibrosis, enlarged lymph nodes, or caseous lesions with abscess formation.
Abstract: The radiological appearances of tuberculosis of the gastro-intestinal tract are presented. One hundred and seventeen cases were seen at the Groote Schuur Hospital over the period 1962–71. In only 44 cases was there evidence of pulmonary tuberculosis. The series included three cases of oesophageal, two of gastric, three of pyloroduodenal, and ten of mesenteric lymph-node tuberculosis, 17 cases of malabsorption or protein losing enteropathy, three of small bowel strictures, 11 ileocaecal lesions, 10 colonic tubercle and 58 of tuberculous peritonitis. The appearance of tuberculosis of the gastro-intestinal tract radiologically depends on the presence of ulceration, fibrosis, enlarged lymph nodes, or caseous lesions with abscess formation. The differentation of tuberculosis from neoplasms or Crohn's disease is discussed and the difficulty and limitations of radiology in this condition is stressed.
TL;DR: The spectrum of X-ray findings in 20 cases of Wegener's granulomatosis have been described, and pulmonary findings are most frequent and range from the rather typical cavitating nodule to the uncommon presentation of lobar consolidation and hilar mass.
Abstract: The spectrum of X-ray findings in 20 cases of Wegener's granulomatosis have been described. The pulmonary findings are most frequent and range from the rather typical cavitating nodule to the uncommon presentation of lobar consolidation and hilar mass. Improvement of lesions in one area, while the lesions in other areas of lung progress is a strong radiological diagnostic clue to this disease. When pulmonary findings coexist with mucosal changes involving the nasopharynx or mastoids, the possibility of Wegener's granulomatosis should be considered. Concomitant kidney disease, when present, makes the probability of Wegener's granulomatosis even greater.
TL;DR: Abnormal arterio-venous communications in the intracranial dura mater may be discovered at angiography performed in the investigation of patients with unrelated disorders, and the importance of recognizing the vascular anomaly is discussed.
Abstract: Abnormal arterio-venous communications in the intracranial dura mater may be discovered at angiography performed in the investigation of patients with unrelated disorders. Five such cases are described. The clinical features in these patients were not directly related to the presence of the dural shunt. The importance of recognizing the vascular anomaly is discussed.
TL;DR: It is indicated that even after 3,000 rads low dose-rate irradiation, the tumours still contain surviving well-oxygenated cells, suggesting that reoxygenation occurs during the irra...
Abstract: The effect on a transplantable mouse tumour (KHT sarcoma) of irradiation at three different continuous low dose-rates (41 rads/hour, 175 rads/hour and 800 rads/hour) and one fractionated radiation regime (470 rad fractions every three hours) has been investigated. The response of the tumours has been measured by determining dose-survival curves for the cells of the tumour using a lung colony assay method. In all cases, the survival curves were found to be the same and quite similar to the one obtained for single acute doses (100 rads/minute). These findings have been further investigated by giving acute irradiation (aerobic or anoxic) immediately following a dose of continuous irradiation. The results of these experiments has indicated that even after 3,000 rads low dose-rate irradiation, the tumours still contain surviving well-oxygenated cells. This finding suggests that the most likely explanation for the results obtained at the different dose-rates is that reoxygenation occurs during the irra...
TL;DR: It was found that pre-treatment with vitamin E increased the LD50 of mice from 565 ±38 rads (95 per cent confidence) to 630 ± 29 rads, and measurement of fractional survival for cells of murine squamous carcinoma irradiated in vivo in mice breathing air indicated that the percentage of anoxic cells in the tumours was raised.
Abstract: The effect of vitamin E in reducing the permeability and increasing the resistance of capillaries might be expected to reduce the blood flow and hence the oxygenation of tissues. The question arises whether pretreatment of mice with vitamin E is associated with a reduced effect of irradiation on the cells of tissues. It was found that pre-treatment with vitamin E increased the LD50 (30) of mice from 565 ±38 rads (95 per cent confidence) to 630 ± 29 rads. Measurement of fractional survival for cells of murine squamous carcinoma irradiated in vivo in mice breathing air indicated that the percentage of anoxic cells in the tumours was raised from 13 per cent in untreated mice to about 35 per cent in mice pretreated with the vitamin.
TL;DR: A new classification of the right aortic arch patterns, based on the site of interruption of the left arch, has been proposed.
Abstract: Three patients with right aortic arch and mirror-image branching of the major arteries are presented. In contrast to those reported in the literature, none had associated cardiac defects and all of them had severe symptoms resulting from vascular ring, which required surgical treatment. A new classification of the right aortic arch patterns, based on the site of interruption of the left arch,has been proposed.
TL;DR: Evidence is presented which indicates that measurements of cell survival in vitro following irradiation in vivo may lead to inaccurate estimates of the “effective” hypoxic fraction in a tumour.
Abstract: A tumour is described for which it is possible to measure the survival of the tumour cells in vitro following irradiation in vivo. Using this tumour, the relationship between cell survival and alterations in tumour growth after irradiation, and the effect of oxygen on this relationship have been studied. The oxygen enhancement ratio for cell killing was 2·5, and for tumour growth delay was 3·0. This difference in the OER's could not be accounted for in terms of differences in post-irradiation proliferation by cells that were either oxic or hypoxic at the time of irradiation. Evidence is presented which indicates that measurements of cell survival in vitro following irradiations in vivo may lead to inaccurate estimates of the “effective” hypoxic fraction in a tumour. The results suggest that there may be qualitative differences between the types of damage expressed in situ and in vitro, and that techniques which involve the removal of cells from their normal environment may lead to incorrect estim...
TL;DR: The radiological findings in 100 cases of proved pulmonary paragonimiasis as seen in Nigeria are reviewed and common shadows are either well defined patches of cavitation, ill-defined “cotton wool” lesions, “streaky” shadows or “bubble” cavities.
Abstract: The radiological findings in 100 cases of proved pulmonary paragonimiasis as seen in Nigeria are reviewed. In order of frequency the common shadows are either well defined patches of cavitation, ill-defined “cotton wool” lesions, “streaky” shadows or “bubble” cavities. The midzones are most commonly affected but any part of the lung may be marked. The shadows are generally of low density and may be difficult to distinguish from the early lesions of pulmonary tuberculosis.
TL;DR: Evidence of bone-marrow expansion was present in all age groups and bone infarction was shown to become increasingly common with age.
Abstract: An analysis of the radiological appearances in a skeletal survey of 61 patients in Jamaica with homozygous sickle cell disease is presented. Evidence of bone-marrow expansion was present in all age groups. Bone infarction was shown to become increasingly common with age. Bone infarction was commonest in the femoral and humeral heads.
TL;DR: Because of the comprehensive diagnostic information provided by the use of these gluconate complexes, they appear to be particularly valuable for renal scintigraphy and permit this technique to be performed on a wide variety of renal disorders.
Abstract: 99Tcm labelled gluconate complexes have been prepared by two methods involving either tin-reduction or electrolysis of the radionuclide in the presence of calcium gluconate. In experimental animals, both types of complex were shown to be highly specific for renal tissue and to be non-toxic. Their suitability for renal scintigraphy was demonstrated in scintillation camera studies in 148 patients. A lyophilized version of the stannous gluconate preparation was found to be equally suitable. Detailed investigation of the biological fate of these complexes in both animals and humans showed that a single study could provide information regarding renal function, patency of excretory pathways and renal morphology. This was confirmed by scintigraphic examinations in a wide variety of renal disorders. Because of the comprehensive diagnostic information provided by the use of these gluconate complexes, they appear to be particularly valuable for renal scintigraphy and permit this technique to be performed o...
TL;DR: The cellular immunity of 64 patients with an histologically proved carcinoma of the lung was investigated using the technique of lymphocyte transformation to phytohaemagglutinin (PHA), and transformation was depressed by radiotherapy.
Abstract: The cellular immunity of 64 patients with an histologically proved carcinoma of the lung was investigated using the technique of lymphocyte transformation to phytohaemagglutinin (PHA). The patients were treated by radical radiotherapy and were tested before treatment, at the end of treatment, and at intervals during follow-up. The average respone of the patients before treatment was lower than that of the controls. Transformation was depressed by radiotherapy. The lymphocyte transformation response before treatment was not related to survival of the patient after treatment, but there is a suggestion that the degree of depression during radiotherapy is related to survival.
TL;DR: Two patients with pseudomembranous colitis showed appearances on barium enema examination which closely resembled acute, universal ulcerative colitis, and both cases had serrations of the colonic margin from rectum to caecum which are caused by the pseudOMembranes which stud an otherwise normal mucosa.
Abstract: Two patients with pseudomembranous colitis showed appearances on barium enema examination which closely resembled acute, universal ulcerative colitis. Both cases had serrations of the colonic margin from rectum to caecum. These serrations are caused by the pseudomembranes which stud an otherwise normal mucosa. The disease may be suspected if known predisposing conditions exist. Both our patients has prior treatment with oral clindamycin. Sigmoidoscopy and rectal biopsy offer modalities for ready diagnosis.
TL;DR: It is suggested that posterior pharyngeal wall lesions are best treated by radiotherapy initially and that further evaluation is needed for post-cricoid lesions.
Abstract: The results of a comparison of 51 patients treated by combined therapy using a high-dose policy and 98 by primary radiotherapy are discussed. Pre-operative radiotherapy in pyriform sinus lesions gives a crude three-year survival of 39 per cent and five-year of 36 per cent as compared with 23 per cent and 16 per cent when radiotherapy is given alone. Similar differences are apparent when analysed by stage. Pre-operative radiotherapy is the treatment of choice for all pyriform sinus growths which do not have fixed or bilateral regional lymph nodes. It is suggested that posterior pharyngeal wall lesions are best treated by radiotherapy initially and that further evaluation is needed for post-cricoid lesions. The morbidity rate of surgery following pre-operative radiotherapy has not been increased. The local recurrence rate is reduced after pre-operative radiotherapy and histopathological evidence is presented to support this. The interval to the first recurrence is also significantly longer after pr...
TL;DR: Two patients with chronic rheumatoid arthritis are presented in whom translucent mass lesions were noted in the synovial cavities of the elbow and the subdeltoid bursa respectively, and these were sufficiently distinct to justify the term lipomata.
Abstract: Two patients with chronic rheumatoid arthritis are presented in whom translucent mass lesions were noted in the synovial cavities of the elbow and the subdeltoid bursa respectively. On the plain films the lesions in both cases were clearly defined and smooth in outline with radiological characteristics of fat or lipid material. In one case arthrography of the shoulder was carried out and the contrast medium clearly outlined a mass with a smooth border, which appeared fixed to the lateral wall of the subdeltoid bursa. Histological verification of this mass showed two pedunculated lesions composed of mature fat and covered by synovium. These were sufficiently distinct to justify the term lipomata.