Biomedical subjects
Publications and source records attributed to S R Ell.
Survival of patients with surgically treated malignancy may be adversely affected by blood transfusion. Immune suppression due to transfusion has been implicated but remains unproven. We conducted a study of 240 patients with squamous cell carcinoma of the larynx undergoing laryngectomy to assess the effect of per-operative blood transfusion on survival.
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Bones are the largest group of foreign bodies found in the air and food passages. Fishbones which lodge in the tonsil can be easily seen and removed relatively easily. Those lodging in the pyriform fossa are well localized by the patient and can usually be seen on mirror examination. It would be useful to know which types of fishbones are radio-opaque and therefore likely to be shown by radiographs when mirror examination is difficult or fails to reveal a foreign body. Therefore a study was undertaken to ascertain the radio-opacity of the bones of ten different species of fish eaten in the British Isles.
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Indirect signs such as clover-leaf deformity, pseudodiverticulum formation, eccentric location of pyloric channel, and flattening of the fornix are of considerable value in the radiologic detection of an ulcer crater. We have found another indirect sign, base line tenting (BLT) to be very useful in the detection and diagnosis of duodenal ulcer disease. This is characterized by interruption of the base line of the bulb, with 2 associated perpendicular lines extending from the base and converging to a point in the duodenal bulb. After we observed this sign in various patients with peptic ulcer disease, a prospective investigation was performed involving 62 patients with duodenal ulcer disease over a period of 2 years. We found the BLT sign in 52 (83.8%). To date, no false-positive incidence has been identified. We concluded that BLT is a most valuable sign in the radiologic identification of duodenal ulcer disease.
The purpose of this study was to assess the potential for rapid acquisition computed axial tomography (Imatron C-100) to quantify regional myocardial perfusion. Myocardial and left ventricular cavity contrast clearance curves were constructed after injecting nonionic contrast (1 ml/kg over 2 to 3 seconds) into the inferior vena cava of six anesthetized, closed chest dogs (n = 14). Independent myocardial perfusion measurements were obtained by coincident injection of radiolabeled microspheres into the left atrium during control, intermediate and maximal myocardial vasodilation with adenosine (0.5 to 1.0 mg/kg per min, intravenously, respectively). At each flow state, 40 serial short-axis scans of the left ventricle were taken near end-diastole at the midpapillary muscle level. Contrast clearance curves were generated and analyzed from the left ventricular cavity and posterior papillary muscle regions after excluding contrast recirculation and minimizing partial volume effects. The area under the curve (gamma variate function) was determined for a region of interest placed within the left ventricular cavity. Characteristics of contrast clearance data from the posterior papillary muscle region that were evaluated included the peak myocardial opacification, area under the contrast clearance curve and a contrast clearance time defined by the full width/half maximal extent of the clearance curve. Myocardial perfusion (microspheres) ranged from 35 to 450 ml/100 g per min (mean 167 +/- 125). Two flow algorithms derived from characteristics of the contrast clearance curves showed a good correlation with regional myocardial flow determined by microspheres: the ratio of the peak myocardial opacification from baseline to the area under the left ventricular cavity curve (r = 0.7, p less than 0.001, SEE = 44.4 ml/min), and the ratio of the left ventricular cavity to posterior papillary muscle curve areas divided by the full width/half maximal contrast transit time in the region of the posterior papillary muscle (r = 0.82, p less than 0.001, SEE = 52.2 ml/100 g per min). The form of these two flow algorithms was derived from classical indicator dilution theory. In conclusion, indices derived from these data correlated well with regional myocardial perfusion in the posterior papillary muscle region of the dog as assessed by microspheres. This approach offers promise for the quantitation of regional myocardial perfusion and myocardial flow reserve in patients.
A case of pulmonary alveolar microlithiasis is presented which has been investigated using X-ray energy spectroscopy and microscopic infrared spectroscopy. These methods gave precise details of the chemical composition of the microliths seen in this unusual disease. The pathogenesis of this disorder is discussed in the light of these findings.
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The influence of clinical history upon detection has been frequently studied. In a unique investigation, detection of diverse abnormalities commonly encountered in practice was tested, and the influence of clinical history was conceptualized as suggesting a tentative diagnosis. Categorical prompts that were correct for specific abnormalities resulted in detection superior to that with unprompted reading. Prompts that were plausible but incorrect for abnormal and normal cases led to very few false-positive responses, and subsequent reports of specific abnormalities were as accurate as in unprompted reading. It is concluded that appropriate clinical history results in improved perceptual performance rather than simply improved decision-making.
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Cine CT, with its very rapid imaging capabilities, was used to evaluate eight adult patients suspected of nonfixed upper airway obstruction. A method was developed for such imaging, which provides 10 images at each of 12 contiguous levels, extending from the soft palate through the extrathoracic trachea. These give a dynamic view of the airway during at least one full respiratory cycle and take about 6 sec to obtain. Results were compared with similar studies in 10 normal volunteers. Seven of the patients showed intermittent obstruction on cine CT, while the eighth was judged normal. All results agreed with subsequent further investigations or confirmed clinical diagnoses. The pathology demonstrated included chondromalacia, laryngeal spasm, and polychondritis. Four patients were evaluated for sleep apnea. All showed dynamic abnormalities of the airway, although they were studied awake and asymptomatic, during normal quiet respiration. All were subsequently shown to have severe sleep apnea. We conclude that cine CT has the potential to provide information quickly and noninvasively on upper airway dynamics and has certain definite advantages over conventional studies.
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Calcification of soft tissue frequently occurs in patients undergoing hemodialysis for chronic renal failure and involves the arteries, eyes, periarticular regions, lungs, heart, abdominal viscera, subcutaneous tissues, and skin. In this report, two such patients are described who presented with apparent pulmonary nodules on their chest roentgenograms obtained on admission. By the use of tomograms and apical lordotic views, both proved to have extrapulmonary calcific deposits in the subcutaneous tissues overlying the upper pulmonary zones. The tendency for these collections to undergo progression, regression, or pseudocavitation is illustrated. Definitive radiographic localization of lesions projecting over the pulmonary fields in patients undergoing hemodialysis is emphasized because of the significantly increased incidence of infection (including tuberculosis), septic embolism, and carcinoma.
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