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Biomedical subjects

M J van der Vis-Melsen

Publications and source records attributed to M J van der Vis-Melsen.

11 recordsLinked to original sources
PubMed1993

Dipyridamole thallium-201 scintigraphy for improved detection of left anterior descending coronary artery stenosis in patients with left bundle branch block.

In patients with left bundle branch block (LBBB) undergoing thallium-201 exercise scintigraphy septal perfusion defects are frequently observed irrespective of the presence or absence of coronary artery disease. Consequently, in these patients the specificity for detecting stenoses in the left anterior descending coronary artery (LAD) by thallium-201 scintigraphy is relatively low. It has been hypothesized that pharmacological vasodilation would result in higher specificity than conventional exercise thallium-201 scintigraphy because of a more uniform exploitation of coronary flow reserve. Twenty-five consecutive patients with LBBB underwent dipyridamole thallium-201 imaging and coronary arteriography within 3 months. The prevalence of coronary artery disease was estimated at 48 +/- 19%. Sensitivity for detection of LAD lesions was 100% and specificity was 88%. The positive predictive accuracy and the negative predictive accuracy were 80% and 100% respectively. The 'false positive' septal defects were of the non-reversible type. The appearance of septal perfusion defects was not dependent on changes in heart rate during dipyridamole infusion. This study indicates the value of dipyridamole thallium-201 imaging for non-invasive detection of LAD stenosis in patients with LBBB.

Aged↗
PubMed1992

Urodynamics in enuretic children.

Although the incidence of an organic cause is low and most of the detected genitourinary anomalies are not responsible for enuresis, a simple, noninvasive screening test is preferable in the analysis of children with enuresis. Extension of standard radionuclide renography as a method of screening the upper as well as lower urinary tract function in one session is noninvasive and at least as good as conventional direct urine flow rate recording. This method was carried out in 124 children. In 30%, some abnormality probably related to the enuresis was identified. Upper urinary tract anomalies were identified in 5% of the children, anomalies of the upper and the lower urinary tract in 9.6%, and functional voiding disturbances in 16%.

Adolescent↗
PubMed1989

Scintigraphic assessment of lower urinary tract function in children with and without outflow tract obstruction.

Analysis of lower urinary tract function with an extension of standard renography with 123I-hippurate was carried out in 199 children. Maximum bladder capacity, voiding and residual bladder volumes, average and maximum urine flow rates and urine flow patterns were estimated. The index of urine transport (IUT), representing the relationship between urine flow rate and bladder volume, was introduced as a measure of outflow capability. Of 129 children without evidence of outflow obstruction, 90% had a normal urine flow pattern; in 96% the average IUT was 0.8 or higher and in 87% the maximum IUT was 1.2 or higher. A sawtooth-shaped pattern with both normal and abnormal IUT values was observed in 10% of these children. In 63% of the children with outflow tract obstruction there was a low, flat urine flow pattern together with decreased IUT values. A sawtooth-shaped pattern with varying IUT values was observed in 15%, whereas in 20% the urine flow pattern and IUT values were normal. This extension of standard radionuclide renography as a method of screening lower urinary tract function is recommended. It is at least as good as conventional direct urine flow rate recording, it has the advantage of being non-invasive and it is also part of an established urological investigation.

Adolescent↗
PubMed1988

Urodynamics: a noninvasive screening of lower urinary tract function in children with radioisotopes.

A noninvasive intravenous assessment of lower urinary tract function with 123I-hippurate was carried out in 129 children without suspicion of lower urinary tract outflow pathology. Without increasing the radiation burden standard renography was extended by lower urinary tract function analysis in the same session. The maximum bladder capacity, voiding and residual bladder volumes, average and maximum urine flow rates were calculated and the relation between the urine flow rate and bladder volume expressed as the index of urine transport (IUT). This index seems to be a much more reliable standard than isolated measurements of urine flow rates and bladder volumes in screening lower urinary tract function. Three different urine flow patterns were recognized: a single sharp peak (in 70%) and a biphasic curve (in 20%) were considered to be normal. A sawtooth-shaped pattern, observed in 10% of the children, may be caused by detrusor malfunction. The prolonged time necessary for this more extensive analysis of the lower urinary tract is well compensated by the additional information gained.

Adolescent↗
PubMed1982

Sensitivity of scrotal scintigraphy in the diagnosis of varicocele.

Scrotal scintiangiography was performed in 136 infertile males. Thirty patients (22%) were clinically suspected of varicocele. Scintigraphically, the number of abnormal observations was much higher (52 patients, 38%). Correlation of scintigraphic findings with results of clinical examination, surgical data, and sperm analysis indicated a sensitivity of 86 to 92% for scrotal scintigraphy, whereas the sensitivity for clinical evaluation is only 50%.

Adolescent↗
PubMed1981

Value of the determination of "true' free thyroxine in screening the newborn with possible congenital TBG-deficiency for congenital hypothyroidism.

The results of investigation on a family after a screening programme for congenital hypothyroidism are presented. The newborn child and her father appeared to have a congenital thyroxine binding globulin deficiency. Problem regarding standard thyroid hormone tests are discussed. It was observed that the free T4 index as well as a commercial free T4 determination introduced earlier can give misleading results. The first experience with another more promising free T4 determination is also presented.

Adult↗