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Biomedical subjects

H W Gray

Publications and source records attributed to H W Gray.

At least 37 records · Page 2Linked to original sources
PubMed1995

Indium-111 leucocyte scintigraphy and ultrasound scanning in the detection of intra-abdominal abscesses in patients without localizing signs.

The clinical records of 45 patients with suspected intra-abdominal sepsis but without localizing abdominal signs were retrospectively reviewed. All had undergone both indium-111 leucocyte scintigraphy and real time ultrasound. Twenty-two of the 45 patients were subsequently shown to have intra-abdominal abscesses. Twenty-one patients were identified correctly by indium-111 scintigraphy (sensitivity 95%) and 10 by ultrasound (US: sensitivity 45%). There were two false positive scintiscans (specificity 91%) but no false positive US scans (specificity 100%). There was no correlation between the peripheral white cell count and the presence of absence of an abscess or the likelihood of obtaining a positive scintiscan result. Because of the excellent specificity ultrasound scanning should remain the initial investigations in this group of critically ill patients with indium-111 scintigraphy being used to clarify the US findings or in US negative patients.

Abdominal Abscess↗
PubMed1993

Radionuclide migration through the genital tract in infertile women with endometriosis.

The migration of radionuclide through the genital tract was observed, comparing 20 patients with endometriosis and infertility with a control group of 23 infertile patients who had a normal pelvis. All patients had patent tubes at laparoscopy and chromopertubation, performed in both groups for the investigation of infertility and to diagnose the presence and extent of endometriosis. A radionuclide tubal test, using human albumin microspheres labelled with 99m-technetium (99mTc) was subsequently undertaken to observe the extent of genital tract migration of radionuclide to uterus, Fallopian tube and peritoneal cavity. The results show that radionuclide migration to the peritoneal cavity was impaired in patients with endometriosis, compared with the control group (30 versus 83%, respectively; P < 0.001). There was no relationship between migration and the severity of endometriosis. We conclude that impaired tubal function may be a cause of infertility in some patients with endometriosis.

Adult↗
PubMed1993

Lung scan reports: interpretation by clinicians.

A questionnaire was sent to 217 consultant physicians in Scotland who were likely to encounter pulmonary embolism (PE) in their daily practice. Replies were received from 194 (89%). Only 34% of physicians understood that a normal lung scan made PE highly unlikely, while 65% considered a low probability scan equivalent to an uncertain diagnosis. This pattern of interpretation of lung scan reports was confirmed by a question on post-test management. After a normal lung scan report, 31% of physicians were uncertain about the diagnosis and this uncertainty increased to 37% for a low probability scan report. This survey has shown misunderstanding by a significant number of physicians of the risk of PE indicated by normal and low probability lung scan reports. It underlines the need for individuals reporting the test to provide informed guidance for clinical staff following ventilation/perfusion (V/Q) imaging. It may point in addition to a need for a more easily understood style of reporting of lung scans.

Humans↗
PubMed1993

Lung scan reporting language: what does it mean?

The aim of this study was to analyse the understanding of the verbal probability language used for communicating lung scan findings. A questionnaire providing a series of expressions of probability in lung scan reporting was sent to 211 consultant nuclear medicine providers in the UK. Respondents were asked to estimate the probability of pulmonary embolism (PE) communicated by each reporting expression on a visual linear probability scale. Analysis of 135 replies revealed a wide variation in the interpretation of the probability language. We suggest that different training, the nature of the probability scale itself and the difficulties of expressing a verbal report on a numerical scale are major reasons for this finding. We conclude that use of verbal probability language complicates the communication of PE risk and that likelihood ratios provide a logical alternative.

Communication↗
PubMed1992

Vertebral metastases and an equivocal bone scan: value of magnetic resonance imaging.

To assess the value of magnetic resonance imaging (MRI) in the investigation of patients with suspected but nonproven vertebral metastases 45 consecutive patients referred in a 6 month period with known primary malignancy and back pain in whom an isotope bone scan was reported as equivocal were studied. All patients had abnormal isotope uptake localized to the spine. Twelve patients were shown to have bony metastases on plain X-ray. In the remainder, where X-rays showed normal or benign appearance, MRI of the spine was offered. Twenty-four patients underwent MRI examination which showed vertebral metastases in 11 cases. Magnetic resonance imaging is shown to be a useful, noninvasive, complementary investigation for evaluation of patients known to have malignant disease and suspected of having vertebral metastases on bone scintigraphy.

Back Pain↗
PubMed1991

Investigation of tubal infertility by radionuclide migration.

Investigation of the tubal factor in infertility is limited to an assessment of anatomical structure and tubal patency. No test of ascendant tubal function is currently available. The migration of radionuclide (99mTc-labelled human albumin microspheres) through the genital tract in 96 infertile women was compared with pelvic findings at laparoscopy and chromopertubation. The radionuclide test correlated with laparoscopy in the diagnosis of patency or blockage in 83 cases (86%). In nine patients, where 'blockage' was diagnosed on the radionuclide test but patency found at laparoscopy, a higher prevalence of pelvic abnormality was found, compared to the 78 patients where both tests demonstrated patency (P less than 0.02). The radionuclide test may facilitate detection of diseased but patent tubes and, as an adjunct to laparoscopy and chromopertubation, may provide useful information about tubal function.

Endometriosis↗
PubMed1991

Augmentation of parathyroid 201Tl/99Tcm scanning by infusion of trisodium edetate.

A significant number of patients with primary hyperparathyroidism have negative preoperative 201Tl/99Tcm subtraction localization scans. In this study an attempt was made to improve scan localization by creating a period of relative hypocalcaemia and increased parathyroid hormone (PTH) secretion before scanning. Six patients with primary hyperparathyroidism were studied (mean serum calcium 2.80 mmol l-1; range 2.70-2.95). All had had a negative standard 201Tl/99Tcm scan carried out within the 6 months prior to this study. Patients were commenced on an intravenous infusion of the calcium chelating agent trisodium edetate at a dose of 24 mg kg-1 h-1 given in 500 ml 0.9% saline over 90 min. Immediately thereafter a 201Tl/99Tcm scan was carried out in the usual way. Three patients showed areas of discordant thallium uptake consistent with the presence of a parathyroid adenoma. Two of these patients had surgery and an adenoma was found at the site corresponding to the scan appearances. It would appear that creating relative hypocalcaemia and increasing PTH secretion may allow increased thallium uptake, possibly secondary to the increased cellular metabolic activity, and thus creating a positive scan.

Adenoma↗
PubMed1991

Intact parathyroid hormone concentration and cyclic AMP metabolism in thyroid disease.

In 35 thyrotoxic patients and 35 patients receiving thyroxine replacement therapy mean serum intact parathyroid hormone concentrations were lower than in euthyroid normal volunteer controls. In 20 hypothyroid patients intact PTH was increased relative to euthyroid controls. Mean serum adjusted calcium was increased in thyrotoxic patients relative to euthyroid controls and in 8 toxic patients with elevated serum adjusted calcium (greater than 2.60 mmol/l) intact PTH was below the assay detection limit (less than 0.5 pmol/l). Indices of PTH activity were consistent with intact PTH measurements in thyrotoxic patients with nephrogenous cyclic adenosine monophosphate lower, tubular maximum reabsorption of phosphate higher, and urinary calcium creatinine ratio higher than controls. In hypothyroid patients these indices of PTH activity suggest relative end organ resistance to PTH with nephrogenous cyclic adenosine monophosphate similar, tubular maximum reabsorption of phosphate similar, and calcium creatinine ratio lower than in controls. In treated hypothyroid patients nephrogenous cyclic adenosine monophosphate was higher, tubular maximum reabsorption of phosphate similar, and calcium creatinine ratio higher than in controls. These results are compatible with the hypothesis that thyroid status modifies the renal responses to PTH (1-84).

Adolescent↗
PubMed1990

Indium 111 leucocyte scintigraphy in abdominal sepsis. Do the results affect management?

We have studied the clinical utility of indium 111 autologous leucocyte scintigraphy retrospectively in 45 patients presenting with suspected intra-abdominal sepsis. The sensitivity was 95% (21/22) and the specificity was 91% (21/23). Some 34 of the studies (17 positive and 17 negative) were considered helpful in furthering patient management (76%) and 8, unhelpful (18%). In 3, the study results were misleading and led to inappropriate treatment. Indium 111 scintigraphy, whether positive or negative, provides information in patients with suspected intra-abdominal sepsis upon which therapeutic decisions can be based.

Abdomen↗
PubMed1990

Lung scanning for pulmonary embolism: clinical and pulmonary angiographic correlations.

A group of 78 patients with suspected pulmonary embolism was studied by both ventilation perfusion lung scanning and pulmonary angiography. Symptoms and clinical signs were analysed using Bayesian techniques to produce pre-test odds for pulmonary embolism in individual patients. While, as a group, those with embolism could be discriminated from those without on this basis, major overlap existed between the groups, invalidating the use of this approach for individual patients. Strict diagnostic criteria for interpretation of lung scans were accurate using pulmonary angiography as the 'gold standard', but at the expense of a significant number of patients (38 per cent) in the indeterminate (non-diagnostic) group. In the 48 patients in whom the test yielded a diagnostic result, there was a sensitivity of 100 per cent (15/15) and a specificity of 97 per cent (32/33). In the series as a whole, the likelihood of lung scanning correctly diagnosing pulmonary embolism was 55 per cent (15/27) and of correctly excluding embolism, 63 per cent (32/51). By the use of strict criteria for interpretation of lung scanning, reliable information can be obtained on the presence or absence of pulmonary embolism in a large proportion of patients suspected of having the condition. Such information is more discriminating than clinical signs and symptoms.

Adult↗
PubMed1990

Ophthalmopathy in early thyrotoxicosis--relationship to thyroid receptor antibodies and effects of treatment.

A prospective study of 25 newly diagnosed thyrotoxic patients was undertaken to determine the incidence and severity of ophthalmopathy in the early stages of the disease. A quantitative analysis of the ocular muscle changes was made using B scan ultrasonography, and the effects of treatment for the thyroid disease on the course of the eye changes was assessed. Although the majority (75%) of patients showed only mild clinical signs of ophthalmopathy (Werner Class 3 or less), 92% had ultrasonographic evidence of ocular muscle enlargement. Clinical involvement of the extraocular muscles was seen in 12% of the cases. There was an inverse correlation between the serum level of thyroid stimulating hormone receptor antibody (TR Ab) and the size of the extraocular muscles. Recovery of the euthyroid state with treatment was accompanied by a decrease in orbital infiltration in some cases, both clinically (reduced amplitude of intraocular pressure rise on elevation of the globe) and by ultrasonography, but the improvement was not statistically significant.

Adolescent↗
PubMed1990

Gallbladder emptying following cholecystokinin and fatty meal in normal subjects.

A quantitative study of gallbladder emptying using 99mTc-HIDA as a bile tracer was performed with either CCK or a fatty meal as gallbladder stimulant. Its aims were to establish; (1) the reproducibility of CCK- and fatty-meal-induced gallbladder contraction, and (2) temporal patterns of gallbladder emptying following a physiological meal. Nineteen healthy, fasted volunteers were selected for 3-minute CCK administration (IV Boots Pancreozymin 2CHR units/kg) or a 40 g fatty meal. Each underwent repeat scans not less than 14 days after the first. Quantitative activity/time curves were drawn with computer analysis establishing gallbladder ejection fractions (GBEF) for each stimulus. Our results demonstrated: (1) poor reproducibility of CCK-induced gallbladder contraction precluding its diagnostic use, (2) improved but still variable meal-induced gallbladder contraction, and (3) evidence for a neurocephalic emptying response with a fatty meal stimulus.

Adult↗