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Biomedical subjects

P Shorvon

Publications and source records attributed to P Shorvon.

9 recordsLinked to original sources
PubMed1992

Multiple-fibre low-power interstitial laser hyperthermia: studies in the normal liver.

Multiple four-fibre low-power interstitial laser hyperthermia was performed in the canine liver to establish the parameters with which large areas of thermal necrosis could be made. Using 1.5 W for 670 s (4020 J in total) and a fibre spacing of 1.5 cm, lesions with dimensions of 3.6 x 3.1 x 2.8 cm were achieved in 75 per cent of those attempted. There was no mortality and a low morbidity rate. These lesions could be visualized in both their development and resolution using ultrasonography. Healing occurred by 1 year. Temperatures in the centre of the heated region were 60 degrees C, which is more than enough to cause thermal cell death. There was good correlation between the temperatures recorded, the sonographic changes seen, and the pathological evidence of necrosis. Multiple-fibre low-power interstitial laser hyperthermia performed with ultrasonic guidance may be of use in the treatment of liver tumours.

Animals↗
PubMed1992

Ultrasound features of low power interstitial laser hyperthermia.

Low power interstitial laser hyperthermia (ILH) is a reliable means of producing in situ thermal necrosis. Ultrasonic studies have been carried out of the changes that occur in canine liver during ILH performed at laparotomy. With a single fibre delivering Nd-YAG laser at 1-1.5 W for 670 s an hyperechoic region developed at the fibre tip measuring 5-6 mm in diameter; around this developed an area of hypoechoic change (up to 500s) giving a total area of changed echogenicity of 14-16 mm. With a multiple fibre system using 4 laser fibres simultaneously the sonographic changes were a summation of the changes seen with a single fibre, the hypoechoic areas overlapping. With this four fibre system the creation of large (3.5 x 2.8 cm) areas of thermal necrosis was possible. There was good correlation between the sonographic and pathological measurements of the region of thermal change. The sonographic studies showed the extension and overlap of regions of thermal necrosis and allowed visualization and accurate measurement of the area undergoing change. The same combined technique has been successfully applied in a small number of clinical cases and may be of use in the treatment of tumours in solid organs.

Animals↗
PubMed1989

Off-period belching due to a reversible disturbance of oesophageal motility in Parkinson's disease and its treatment with apomorphine.

Two L-dopa-treated patients with Parkinson's disease who developed distressing belching during "off" periods are reported. In each case, contrast cine radiography revealed disturbed oesophageal motility which disappeared after injection of the dopamine receptor agonist apomorphine. It is suggested that central dopaminergic abnormalities may be important in the aetiology of "off period belching."

Aged↗
PubMed1988

Prospective comparison of double contrast barium enema plus flexible sigmoidoscopy v colonoscopy in rectal bleeding: barium enema v colonoscopy in rectal bleeding.

Rectal bleeding often heralds serious colonic disease. The literature suggests that colonoscopy is superior to barium enema plus sigmoidoscopy, although no good comparative studies exist. Seventy one patients with overt rectal bleeding had prospectively flexible sigmoidoscopy, double contrast barium enema and colonoscopy completed independently. Against the gold standard, the sensitivity and specificity of colonoscopy were 0.69 and 0.78 respectively for a spectrum of colonic lesions, while for combined flexible sigmoidoscopy and double contrast barium enema these values were 0.80 and 0.56, respectively. When assessing adenoma or carcinoma, colonoscopy was more sensitive at 0.82 v 0.73, while flexible sigmoidoscopy plus double contrast barium enema was superior for detecting diverticular disease. The positive predictive value for colonoscopy was 0.87 against 0.81 for flexible sigmoidoscopy and double contrast barium enema. This study confirms that colonoscopy should be a first line investigation in subjects likely to require biopsy or therapeutic intervention.

Barium Sulfate↗
PubMed1988

Defecography commode.

A mobile wooden commode was designed and built for use in defecography. The commode is made of 1/2-inch-thick plywood with birch veneer and a solid clear pine seat. Water or copper sheets are recommended for radiation filtration. A radiopaque ruler attached to the commode with a spring enables midline measurements. The modifications suggested by the authors have helped with setup and have improved the images acquired.

Humans↗
PubMed1987

A comparison of Golytely and standard preparation for barium enema.

A randomized prospective trial was performed comparing Golytely (with bisacodyl) with our standard two-day catharsis and bowel washout regimen as colon preparation for double-contrast barium enema examinations. Of the 107 patients who participated, 50 received the standard preparation and 57 Golytely. Two radiologists reviewed the enema films without knowledge of which preparation had been used. No significant difference was detected either in the number of failed preparations or in the quality. We conclude that routine use of Golytely is preferable to methods involving catharsis and standard tap water enemas for barium enema examination, on the grounds that it is equally effective, yet more convenient for patients and for the radiology department, and reduces total costs.

Barium Sulfate↗
PubMed1985

Invasive ultrasound imaging.

Ultrasound imaging is an invaluable method of diagnosis in soft tissues. In a single decade, technological progress has converted a technique practised by a few enthusiasts into a high resolution tool accessible to any clinician. The equipment cost is low and the technique does not involve ionizing radiation, is noninvasive, and is comfortable for the patient. What is the justification for the emerging techniques of invasive ultrasound imaging?

Abdomen↗