Rapid radiochemical neutron activation analysis for iodine in urine by different separation techniques.

In the present work on radiochemical neutron activation analysis for the determination of iodine in urine samples, the performance of three different radiochemical separation techniques, namely, direct extraction, use of an iodinated ion-exchange resin column and Schöniger combustion, were intercompared and validated. The practical advantages of the iodinated-resin technique make it most suitable for the rapid routine determination of iodine in urine. It was further verified by participation in an international intercomparison run of urine analysis, and used in a pilot study on iodine determination in the urine of 171 Slovenian schoolchildren, where it gave results in good agreement with the catalytic method.

Reproducibility of quantitative hexakis-2-methoxyisobutylisonitrile single photon emission tomography in stable coronary artery disease.

The quantification of myocardial perfusion abnormalities is necessary to allow comparison of repeated studies, especially in the evaluation of the success of medical, interventional or combined treatment in stable coronary artery disease or in evolving myocardial infarction. The purpose of this study was to assess inter-observer reproducibility of tomographic study processing using a semi-automatic quantitative programme. Technetium 99m hexakis-2-methoxyisobutylisonitrile (99mTc-Sestamibi) was chosen for tomographic imaging of repeated rest-stress studies in patients with stable coronary artery disease. The quantification was performed using a modification of the Cedars polar coding and comparison with the normal data base. The perfusion defects were quantified separately for each standard perfusion area [left anterior descending (LAD), right coronary (RCA) and left circumflex (LCX) arteries] and total area of hypoperfused myocardium. The inter-observer variability for 40 tomographic studies was accomplished. The defects were the largest in the LAD perfusion area (average 19.7% of the normalized LAD supply area) with an inter-observer correlation of 0.84 for this region. The greatest variability was found for the LCX region (r = 0.55) and is attributed to a small average perfusion defect (7.1%), only 18 studies having abnormal perfusion in this area. In total, an average 14.3% of the left ventricular myocardium was significantly hypoperfused, and the inter-observer correlation was 0.87. These results show good inter-observer reproducibility using semi-automatic quantitation of perfusion defects. Careful interpretation of smaller defects in the evaluation of treatment results is advised when repeated 99mTc-Sestamibi single photon emission tomography studies are processed by more than one observer.

Detection of electrocardiographically imperceptible ventricular pre-excitation by phase imaging.

The sequence of ventricular contraction was studied by radionuclide phase imaging in 25 patients with Wolff-Parkinson-White syndrome. The studies were performed when no signs of precontraction were present in the electrocardiogram; in these cases pre-excitation was either intermittent or suppressable by injection of ajmaline. In 11 of the 16 patients with free wall accessory pathways, precontraction could be detected in spite of electrocardiographically absent pre-excitation. Discrete precontraction was seen also in 2 of the 9 patients with paraseptal accessory pathways. We conclude that antegrade conduction through the accessory pathway does not need to be completely blocked if signs of pre-excitation are absent on the electrocardiogram, and that phase imaging is, at least in some patients (especially those with free wall accessory pathways), a more sensitive technique for detection of pre-excitation (precontraction) than the electrocardiogram.

Localization of accessory pathways in Wolff-Parkinson-White syndrome by phase imaging.

Phase image analysis of blood pool scintigrams was performed in 6 patients with Wolff-Parkinson-White (WPW) syndrome to determine the relationship of phase changes and abnormalities of atrioventricular conduction. The site of preexcitation was located by invasive endocardial mapping. The phase advance generally correlated with the electrophysiologically determined location of the accessory pathway. Factors which increase or decrease the amount of preexcitation also increased or decreased the advance of mean phase angles. Phase imaging is a useful noninvasive means for tentative location of accessory pathways in WPW syndrome.

[Spenic abscesses]. / Absces vranice.

Abscess of the spleen is an uncommon entity that seems even less common as it still represents a diagnostic problem. The most common cause of splenic abscess is metastatic hematogenous seeding of the diseased spleen especially of the infarcted areas or traumatic hematomas. It can result also from the direct spread of infection from surrounding structures. Many patients with splenic abscess have a rapidly progressive generalized sepsis and even the combination of well-timed surgery and antibiotic therapy is not always curative. Local symptoms may be mild and overlooked and there may be only general symptoms of suppuration present. X-rays investigations often yield valuable information about the location of the abscess. By far the most promising technique is splenic scanning with the use of radioisotopes. Our case of splenic abscess following appendicitis has been described. The course and the diagnosis has been established using liver-spleen scanning. The patient was treated with Obracin and Dalacin and the diseased spleen has been removed. After drainage of the left subphrenic abscess the recovery was uneventful.