Small particle size of a solid meal increases gastric emptying and late postprandial glycaemic response in diabetic subjects with gastroparesis.

Our goal was to investigate if food of small particle size increases the gastric emptying rate and lessens the fall in postprandial blood glucose in seven subjects with Type 1 diabetes and gastroparesis. Two solid meals of identical composition but of different particle size, with 5MBq (99m)Tc added to the meals, were ingested in randomized order in seven subjects with Type 1 Diabetes Mellitus and gastroparesis and seven healthy subjects. During 180min blood glucose and insulin concentrations were measured and gastric emptying of the ingested meals was registered by a gamma camera.

Body composition during GH replacement in adults - methodological variations with respect to gender.

Objective: Men with growth hormone deficiency (GHD) may be more sensitive to GH treatment than women in terms of changes in body composition. We have studied whether age, body-mass index (BMI) and the different types of methodology used to assess body composition may explain these differences.

Design: Forty-four men and forty-four women with GHD, closely matched for age and BMI, were studied before and after 6 months of GH replacement.

Determination of potassium in the skeletal muscles by whole-body counting.

Changes in muscular function are related to nutritional status, disease and physical activity. To study these relationships, it is desirable to be able to determine the whole body potassium content, which is characteristic to the muscular tissue. This can be achieved by measurements in a whole-body counter, identifying contributions from the upper and lower parts of the body.

A method to obtain the same levels of CT image noise for patients of various sizes, to minimize radiation dose.

The aim of this study was to develop a method of obtaining the same levels of CT image noise for patients of various sizes to minimize radiation dose. Two CT systems were evaluated regarding noise characteristics using phantoms and dosimetric measurements. Both CT systems performed well at dose levels used in normal clinical imaging, but only one was found to be suitable for low radiation dose applications.

The magnitude of signal errors introduced by ISIS in quantitative 31P MRS.

It is well known that the quality of a quantitative 31P MRS measurement relies largely on the performance of the volume selection method, and that image selected in vivo spectroscopy (ISIS) suffers from contaminating signal caused mostly by T1 smearing. However, these signal errors and their magnitude are seldom addressed in clinical studies. The aim of this study was therefore to investigate the magnitude of signal errors in 31P MRS when using ISIS.

A prospective study of 5 years of GH replacement therapy in GH-deficient adults: sustained effects on body composition, bone mass, and metabolic indices.

GH replacement therapy has proved its efficacy and safety in short-term trials and in a few long-term trials with limited number of subjects. In this 1-center study, including 118 consecutive adults (70 men and 48 women; mean age, 49.3 yr; range, 22-74 yr) with adult-onset GH deficiency, the effects of 5 yr of GH replacement on body composition, bone mass, and metabolic indices were determined.

Point-wise measurements of MRS volume selection performance are insensitive to magnetic susceptibility effects of phantom materials.

The purpose was to analyse magnetic susceptibility effects on accuracy of point-wise measurements of signal profiles in the assessment of MRS volume selection performance. An existing phantom design consisting of a sphere with a movable signal source was used for the investigation. The influence from the phantom on magnetic field homogeneity was measured with phase sensitive 1H imaging and 31P spectroscopy on a 1.

Extended ISIS sequences insensitive to T(1) smearing.

Image selected in vivo spectroscopy (ISIS) is a volume selection method often used for in vivo (31)P MRS, since it is suitable for measurements of substances with short T(2). However, ISIS can suffer from significant signal contributions caused by T(1) smearing from regions outside the VOI. A computer model was developed to simulate this contamination.

Performance of 2D 1H spectroscopic imaging of the brain: some practical considerations regarding the measurement procedure.

This paper deals with some of the practical considerations in the planning and performance of chemical shift imaging (MRSI or CSI) of the brain. It contains some aspects of 1) the imaging procedure (MRI), i.e.

A gamma camera for measurements of internal contamination after a radiological accident.

After a radiological accident with the release of large amounts of radionuclides into the environment, measurements of the external and internal exposure of the public will be urgently required. The aim of this study was to investigate the properties of a gamma camera with regard to measurements of internal contamination. The gamma camera was used as a detector without any imaging function.

Determination of tissue volumes. A comparison between CT and MR imaging.

Purpose: To evaluate MR imaging for tissue volume measurements.

Material And Methods: Imaging was done with a spoiled gradient echo technique using the human lower leg as a simple model and CT as the reference technique. Areas of adipose tissue, muscle plus skin and bone tissue were evaluated in 5 volunteers using signal intervals (MR) and attenuation intervals (CT) defined by histograms.

Signal profile measurements of single- and double-volume acquisitions with image-selected in vivo spectroscopy for 31P magnetic resonance spectroscopy.

The volume-selection performance was studied for single- and double-volume-of-interest (VOI) acquisition with the volume-selection method image-selected in vivo spectroscopy for 31P magnetic resonance spectroscopy. High-resolution signal profiles were measured using a phantom simulating a brain. Inside the phantom there was a small, remotely controlled, movable signal source filled with ortho-phosphoric acid.

Radiation dose reduction in CT: application to tissue area and volume determination.

Purpose: To study the potential for radiation dose reduction in computed tomographic (CT) determination of adipose and muscle tissue area and volume, which is an application in which lower spatial resolution or higher image noise can be accepted.

Materials And Methods: Measurements in vivo (in a healthy man aged 52 years; weight, 80 kg) and in phantoms were performed with two standard clinical CT scanners. Tissue areas were determined, and measurement uncertainties were analyzed.

Drug absorption from nifedipine hydrophilic matrix extended-release (ER) tablet-comparison with an osmotic pump tablet and effect of food.

The aim of the present study was to compare the bioavailability of nifedipine when administered as a hydrophilic matrix tablet (ER) and a push-pull osmotic pump tablet (XL) administrated after fasting, and to evaluate the effect of food for the hydrophilic matrix tablet. For this purpose, three separate studies were performed on healthy volunteers (n = 58) including gammascintigraphic monitoring of tablet erosion and localisation in the gastrointestinal tract for ER in one study. Both ER and XL provided almost constant drug delivery over 24 h, after administration under fasting conditions, and bioequivalence was obtained according to 90% confidence intervals of the difference between formulations within 80-125% for Cmax and AUC.

In vitro and in vivo erosion of two different hydrophilic gel matrix tablets.

The aim of the present work was to establish in vivo predictive in vitro tests for the tablet erosion of two different compositions (A and B) of hydrophilic matrix tablets based on hydroxypropyl methylcellulose. The tablet erosion was studied in a modified USP II apparatus at different agitation intensities and ionic strengths according to 2(2) factorial design. The in vivo tablet erosion was studied in 8 healthy human volunteers by gamma scintigraphy after administration of the tablets together with breakfast.

Dose reduction for body composition measurements with CT.

The purpose was to obtain reliable measures of fat and muscle tissue areas with CT at a reduced radiation dose level. Repeated CT-scans with four different levels of reduced radiation dose were perfomed on a water phantom and a volunteer at the L4-L5 level. Dose measurements were performed in a phantom and free in air.

A comparison of different methods to measure body composition in patients.

A comparison of different methods to measure body composition in growth hormone deficient patients is presented. The technical limitations of the available methods are discussed. The techniques used to measure body composition and fat free mass has been by total body water, total body potassium, dual energy X-ray absorptiometry, bioelectrical impedance and total body nitrogen.

Treatment of superficial basal cell carcinomas using topically applied delta-aminolaevulinic acid and a filtered xenon lamp.

Objective: To evaluate the treatment of superficial basal cell carcinomas (SBCC) using photodynamic therapy with topically applied delta-aminolaevulinic acid (ALA) and a filtered short arc xenon lamp as a light source.

Method: An oil-in-water emulsion containing 20% ALA was applied topically to the lesion sites which were then occluded for 3 h. Irradiation was performed in a single session of 10 min using 125 or 166 mW/cm2 in the wavelength range (620-670 nm, giving a radiation dose of 75 or 100 J/cm2, respectively.

Changes in permeability of sheep's lungs by oleic acid are dose dependent.

Objective: To evaluate a two-isotope technique to detect graded changes in pulmonary microvascular permeability.

Design: Open experimental study.

Setting: University hospital, Sweden.

Gastrointestinal transit of amoxicillin modified-release tablets and a placebo tablet including pharmacokinetic assessments of amoxicillin.

Background: We have investigated the gastrointestinal transit time of, the influence of food intake on, the disintegration of, and the pharmacokinetics of amoxicillin in a modified-release form.

Methods: Radiolabelled modified-release tablets of amoxicillin and placebo tablets were administered, in an open three-way, randomized, crossover design, as single doses during omeprazole treatment, to six male healthy subjects during fasting and non-fasting conditions. Radioscintigraphic images and plasma samples were obtained.

Signal profile measurements for evaluation of the volume-selection performance of ISIS.

High-resolution signal profiles obtained with a test phantom were used in this study to evaluate the volume-selection performance of an implementation of ISIS (Image Selected In vivo Spectroscopy). The phantom simulated the brain with regard to volume and loading of coil. A remotely controlled, movable signal source inside the phantom was filled with orthophosphoric acid.

Evaluation of volume selection methods in in vivo MRS. Design of a new test phantom.

In vivo MR spectroscopy (MRS) requires some kind of volume selection method to be able to measure the signal from a selected part of the body. To be able to interpret the spectra correctly, the quality of the volume selection must be investigated for each new MRS application using phantom measurements. A new phantom, especially suitable for precision measurements of the volume selection performance, is presented.

Errors in determination of total body protein by in vivo neutron activation of nitrogen due to non-uniform neutron fluence inside the patient.

Total body protein can be estimated by in vivo neutron activation of nitrogen. The method is based on capture of thermal neutrons in a 14N(n,g )15N reaction. Sources of error associated with this method, such as background subtraction, variations in detection efficiency, etc, are analysed.

Hormones, body composition and cardiovascular risk.

Some 20 compartments of the body may be measured by CT and organ areas determined in 28 CT scans. Advantages of CT are described. While there have been extensive studies of hormones in pre- and postnatal growth, apart from evidence from disease, the role of hormones in adults has been less known.