Dual energy X-ray absorptiometry normal reference range use within the UK and the effect of different normal ranges on the assessment of bone density.

The number of different normal ranges used on dual energy X-ray absorptiometry (DEXA) machines in the United Kingdom was determined by means of a postal questionnaire. Both femoral neck and posteroanterior spine L2-L4 regions were considered. It was clear from this survey that a variety of normal ranges were in use for all manufacturers of DEXA systems.

Ventilation and perfusion lung imaging--which nebulizer?

Three commercially available 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA) aerosol delivery nebulizers for lung ventilation imaging were investigated. Two were air-jet systems, 'Optimist' (Medicaid) and 'Microcirrus' (Amersham), and one was an ultrasonic device (Europlus). Altogether, 112 consecutive patients were scanned, 37 using the Optimist, 40 using the Microcirrus and 35 the Europlus.

Effect of a spacer on pulmonary aerosol deposition from a jet nebuliser during mechanical ventilation.

Background: Several factors have been identified which improve nebulised aerosol delivery in vitro. One of these is the addition of a spacer to the ventilator circuit which improves aerosol delivery from a jet nebuliser to a model lung by approximately 30%. The current study was designed to demonstrate whether similar improvements could be demonstrated in vivo.

The effect of varying type and volume of sedimenting agents on leukocyte harvesting and labelling in sickle cell patients.

Leukocyte labelling in patients with sickle cell anaemia has been reported as difficult if not impossible due to the slow erythrocyte sedimentation rate (ESR) in these patients. This study investigated standard sedimentation methods in patients with sickle cell disease (n = 16) and compared the results obtained with those following changes in the amount and type of sedimenting agent used. Labelling with either 111In-oxine or 99Tcm-exametazime was attempted in only five patients.

Effect of splenectomy on HIV-related thrombocytopenia and progression of HIV infection in patients with severe haemophilia.

Between May 1983 and September 1991 eleven patients with severe haemophilia underwent splenectomy for HIV-related thrombocytopenia. The sustained complete remission rate (platelets > 100 x 10(9)/l) was 82% over a mean follow-up period of 54 months. The group was compared with 22 age-matched non-thrombocytopenic HIV seropositive haemophiliacs who had not undergone splenectomy.

Effect on patient management of a weekend 'on-call' nuclear medicine service.

The Nuclear Medicine Department at Kent and Canterbury Hospital operates a limited weekend on-call service staffed on a rota basis by a technician, a nurse and a doctor. Following a review of the service over a 2-year period, a prospective study was carried out to analyse the workload of the on-call service from August 1991 to July 1992. The aim was to assess the impact of the service on patient management and examine the cost implications.

Gastric emptying in patients with chronic renal failure on continuous ambulatory peritoneal dialysis.

Radionuclide gastric emptying studies were carried out on 20 patients with end-stage renal failure (ESRF) undergoing continuous ambulatory peritoneal dialysis (CAPD). Nine of the patients had diabetes mellitus. Eight normal volunteers were also studied to establish normal ranges.

Aerosols for therapy and diagnosis.

Aerosols are defined as any mixture of solid or liquid particles/droplets that are stable as a suspension in air. Aerosols influence the lives of a large majority of the population. A proportion of particulates exacerbate or induce lung disease.

Nuclear medicine and AIDS.

The human immunodeficiency virus (HIV) infection and its associated illnesses in a relatively young population of patients provides an expanding role for nuclear medicine. The disease enforces a review of each department's infection control procedures. It also necessitates a widening of the differential diagnosis in high risk patients.

Delivery of ultrasonic nebulized aerosols to a lung model during mechanical ventilation.

Ultrasonic nebulizers may be particularly suitable for the administration of therapeutic aerosols to patients undergoing mechanical ventilation, but the amount of aerosol that reaches the patients' respiratory tract during ultrasonic nebulization has not been adequately studied. The delivery through an endotracheal tube of nebulized aerosols labeled with 99mTechnetium human serum albumin was therefore measured for five commercially available ultrasonic nebulizers using an in vitro model representing mechanical ventilation of an adult patient. Delivery of aerosol through the endotracheal tube ranged from 3.

Radionuclides and therapy of thyroid cancer.

The majority of thyroid carcinomas are removed surgically. The appropriate surgical technique is still debated. After surgery the amount of residual thyroid or tumour and the presence of local or distant metastases is often in doubt, particularly if it is not detectable clinically.

Therapeutic aerosols in children.

The use and variety of drugs administered to children as inhaled aerosols is increasing, but little is known about how much drug reaches the lung and how it is distributed there in different age groups. In this article the reasons for measuring aerosol deposition in children are discussed and the potential methods for doing this described. Of the methods available, only the use of radiolabelled aerosols gives accurate information on total lung deposition and distribution.

Regional sympathetic innervation of the heart by means of metaiodobenzylguanidine imaging in silent ischemia.

Metaiodobenzylguanidine was used to determine regional cardiac sympathetic innervation and whether it is reduced in silent ischemia. Patients with silent ischemia (group 1, n = 6) and angina (group 2, n = 5) and normal subjects (n = 6) underwent single-photon emission tomography at 4 hours. From base to midventricle, uptake increased in group 1 (p < 0.

Lung deposition of nebulised pentamidine in children.

Background: Nebulised pentamidine is effective for preventing Pneumocystis carinii pneumonia in adults with acquired immunodeficiency syndrome. The nebuliser dose required to produce equivalent lung concentrations of pentamidine in children is unknown. This study was performed to measure pulmonary pentamidine deposition in children and to relate this to age, ventilation pattern, and body size.

Radiation dose rates from adult patients receiving 131I therapy for thyrotoxicosis.

Recommendations for restricting the exposure to radiation of members of the public coming into contact with thyrotoxic patients treated with 131I are currently based on the activity retained by the patient, and not on the doses likely to be received by such individuals. In order to examine whether these current implications of a reduction in this limit to 1 mSv, measurements were made of the dose rates at distances of 0.1, 0.

Pulmonary deposition of a nebulised aerosol during mechanical ventilation.

Background: There is increasing use of therapeutic aerosols in patients undergoing mechanical ventilation. Few studies have measured aerosol delivery to the lungs under these conditions with adequate experimental methods. Hence this study was performed to measure pulmonary aerosol deposition and to determine the reproducibility of the method of measurement during mechanical ventilation.

Cerebral perfusion deficits in divers with neurological decompression illness.

Cerebral perfusion deficits detected by injection of 99Tcm-hexamethylpropyleneamine oxime (HMPAO) and single photon emission tomography is said to correlate well with clinical findings in divers with neurological decompression illness. We studied 12 divers. Six had residual cerebral signs (group 1) and six had no residual cerebral symptoms or signs (group 2).

Disposition of nebulized pentamidine measured using the direct radiolabel 123I-iodopentamidine.

The pulmonary deposition of nebulized pentamidine (300 mg, Respirgard II nebulizer) was measured in seven human immunodeficiency virus (HIV)-positive men using a new radiopharmaceutical, 123I-iodopentamidine. Mean total pulmonary deposition was 15.3 mg or 5.

Quantification of technetium-99m lung radioactivity from planar images.

Six methods of quantifying technetium-99m lung uptake from planar gamma camera images were evaluated. Camera sensitivities, the broad beam attenuation coefficient and build-up factors were derived from suitable phantom measurements. The accuracy of the methods was evaluated by quantifying the lung uptake of 99mTc macroaggregated albumin (MAA) in ten patients and assuming complete trapping by the lung of the known activity of injected MAA particles.