Biomedical subjects

Rutger A J Nievelstein

Publications and source records attributed to Rutger A J Nievelstein.

4 recordsLinked to original sources

PubMed2006

Skeletal muscle ultrasonography: Visual versus quantitative evaluation.

In this study, we compared the sensitivity and specificity of visual versus quantitative evaluation of skeletal muscle ultrasound in children suspected of having a neuromuscular disorder (NMD). Ultrasonography (US) scans of four muscles (biceps brachii, forearm flexors, quadriceps femoris, anterior tibial muscle) were made in 76 children. All images were visually evaluated using the Heckmatt criteria and quantitatively evaluated with computer-assisted grey-scale analysis of muscle echo intensity. Visual evaluation could achieve a sensitivity up to 71%, with a specificity of 92%. With quantification, a sensitivity of 87% accompanied by a specificity of 67% was found, but other diagnostic values could be achieved, depending on the cut-off point. Quantification resulted in a higher interobserver agreement (kappa 0.86) compared with visual evaluation (kappa 0.53). We conclude that quantification of echo intensity is a more objective and accurate method. Because it can achieve higher sensitivities, it is better-suited for the screening task in the diagnostic phase of children with a NMD.

Adolescent↗

PubMed2006

Effect of satiety on brain activation during chocolate tasting in men and women.

BACKGROUND: The brain plays a crucial role in the decision to eat, integrating multiple hormonal and neural signals. A key factor controlling food intake is selective satiety, ie, the phenomenon that the motivation to eat more of a food decreases more than does the motivation to eat foods not eaten. OBJECTIVE: We investigated the effect of satiation with chocolate on the brain activation associated with chocolate taste in men and women. DESIGN: Twelve men and 12 women participated. Subjects fasted overnight and were scanned by use of functional magnetic resonance imaging while tasting chocolate milk, before and after eating chocolate until they were satiated. RESULTS: In men, chocolate satiation was associated with increased taste activation in the ventral striatum, insula, and orbitofrontal and medial orbitofrontal cortex and with decreased taste activation in somatosensory areas. Women showed increased taste activation in the precentral gyrus, superior temporal gyrus, and putamen and decreased taste activation in the hypothalamus and amygdala. Sex differences in the effect of chocolate satiation were found in the hypothalamus, ventral striatum, and medial prefrontal cortex (all P < 0.005). CONCLUSIONS: Our results indicate that men and women differ in their response to satiation and suggest that the regulation of food intake by the brain may vary between the sexes. Therefore, sex differences are a covariate of interest in studies of the brain's responses to food.

Adult↗

PubMed2005

Knee radiography in the diagnosis of skeletal dysplasias.

BACKGROUND: Flattening of the epiphyses of long bones is seen in several skeletal dysplasias and standardized measurements on a radiograph of the knee to detect skeletal dysplasias using this feature have been described. Since then only two other studies in which this method was used have been published, and both included only a small number of children and neither had a control group. In addition, the Dutch National Working Group on Skeletal Dysplasias began to have doubts about the reliability of the method. We therefore decided to re-evaluate its accuracy in a population of children with and without a skeletal dysplasia. OBJECTIVE: To determine the diagnostic value of standardized measurements on conventional AP radiographs of the knee in children with a skeletal dysplasia. SUBJECTS AND METHODS: We measured the distal femoral metaphysis and epiphysis according to the published method on conventional AP radiographs of the knee in 45 healthy children and 52 children with a skeletal dysplasia. We compared graphically the height of the distal femoral epiphysis with its width and with the width of the femoral metaphysis. Receiver operating characteristic (ROC) curves were calculated for each group of children. RESULTS: All graphs showed a considerable overlap between children with a skeletal dysplasia and healthy children. The size of the area under the ROC curves for the different groups was small, varying between 0.567 and 0.653. CONCLUSIONS: This method does not discriminate between children with a skeletal dysplasia and healthy children. We therefore consider it to be of little diagnostic value.

Adolescent↗

PubMed2003

Ultrasound in the management of the position of the femoral head during treatment in a spica cast after reduction of hip dislocation in developmental dysplasia of the hip.

In this prospective study of 18 hips we compared the efficacy of ultrasound with CT in determining the position of the femoral head in a spica cast after closed or open reduction in children with developmental dysplasia of the hip. Ultrasound was performed through the perineal opening of the cast. With a transinguinal approach, the superior ramus of the pubis, the acetabulum, the femoral head and the femoral neck can be depicted in one plane. The CT and ultrasound images were blinded and reviewed by two of the authors. Ultrasound was inconclusive in the first two reductions since the perineal opening was too small to see all the landmarks in one plane. In the following 16 reductions the landmarks were well defined and interpretation of the CT and ultrasound was similar. The perineal opening in the spica cast should be made in such a way that the ultrasound probe can be positioned in the groin so that the landmarks can be shown in one plane.

Casts, Surgical↗