ABSTRACT
The aim of this work was to compare the advantages and the limitations of several data processing techniques for the assessment of esophageal transit. The following qualitative methods were evaluated: scintigraphic image, cine-display, regional time-activity curve, and condensed image. The quantitative methods evaluated were the pixel to pixel presentation of parameters of the time-activity curves such as time of arrival, time to maximum, and several downslope parameters, mean transit time, mean time, and a new transit parameter based on the radioactive decay. The study allowed us to conclude that for the detection and the quantitation of esophageal transit the method of choice was the combined use of the condensed image and the pixel to pixel mean time image. The parametric image using the transit parameter calculated from decay was shown as a valuable alternative if an ultra-short half-life radionuclide was used as the tracer.
Subject(s)
Esophagus/physiology , Esophagus/diagnostic imaging , Humans , Krypton , Methods , Peristalsis , Radioisotopes , Radionuclide ImagingABSTRACT
An international project was set up to study the clinical usefulness of intrarenal transit times derived from the renogram by deconvolution. A common data sheet, to collect clinical, biochemical, radiological and isotopic information, was completed by the centres. Five hundred and ninety-one patients were studied and the results analysed. The mean transit time (MTT) in normal kidneys was found to be 3.6 +/- 1.1 min. If the MTT is greater than 7.6 min, a kidney is likely to be obstructed. In vesico-ureteric reflux, the transit times are prolonged, but they are normal in infection, hypertension, parenchymal disease and minimally irradiated kidneys. In transplantation, when the kidney is normal, the transit times are shorter than in the natural kidney; in acute rejection, transit time are prolonged.
Subject(s)
Kidney Diseases/diagnosis , Radioisotope Renography/methods , Adult , Child , Constriction, Pathologic , Graft Rejection , Humans , Hypertension, Renal/diagnosis , Kidney/metabolism , Kidney Transplantation , Models, Biological , Time Factors , Urinary Tract Infections/diagnosis , Vesico-Ureteral Reflux/diagnosisABSTRACT
A new technique for measuring glomerular filtration in each kidney has been developed using a scintillation camera and the 99mTc-DTPA complex. The technique has been applied to 101 children with various uropathies. Correlations with the total and separate creatinine clearance, the HgCl2 uptake test, and the maximal urinary concentration have been good. The reproducibility of the method has been satisfactory in a small number of patients. The test is particularly adapted to children because of its simplicity, reduced trauma, short duration (20 minutes) and low-radiation dose. In contrast to some other radioisotope techniques, it can be carried out in infants.
Subject(s)
Glomerular Filtration Rate , Kidney Glomerulus/diagnostic imaging , Technetium , Adolescent , Child , Child, Preschool , Creatinine , Humans , Infant , Kidney Concentrating Ability , Methods , Radionuclide Imaging , UrographySubject(s)
Kidney Diseases/diagnostic imaging , Aged , Child, Preschool , Diagnostic Errors , Female , Humans , Injections, Intravenous , Male , Models, Biological , Radionuclide ImagingABSTRACT
A new radioisotopic method of determining the separate glomerular clearance of the kidneys is described. After injection of 99mTc-DTPA, the data from a scintillation camera are recorded by computer. The renal curves are corrected for extrarenal activity and the plasma curve is obtained from a precordial curve. At each instant the slope of the renal curve divided by the corresponding plasma concentration gives the separate clearance value, in the period extending from 80 to 180 s after injection of the tracer. The error and correction factors introduced are discussed. Normal values are established on 25 patients and correspond to inulin clearance values. Left kidney: 60 ml/min (SD=13). Right kidney: 57 ml/min (SD=12). The method is simple for the patient, takes only 20 min, is not dangerous, is particularly applicable to young children and can be repeated frequently in the same patient.
Subject(s)
Kidney Function Tests/methods , Kidney/diagnostic imaging , Pentetic Acid , Technetium , Adolescent , Adult , Child , Child, Preschool , Glomerular Filtration Rate , Humans , Infant , Radionuclide Imaging , Technology, RadiologicABSTRACT
Thallium-201 scintigraphy of the exercised myocardium was performed in 70 male patients admitted for coronary arteriography and left-ventricular angiography. Left ventricular scintigrams were collected in left lateral, left anterior oblique (65 degrees, 45 degrees, and 25 degrees), and anterior views, and the images were divided into eight segments: apical, anteroseptal, anterior, antero-lateral, posterolateral, posterior, inferior, and posteroseptal. A correlative study between segmental hypoperfusion on scintigram and coronary-artery stenosis visualized by contrast artriorgraphy allowed selection of specific segments for each main coronary artery. Hypoactivity in the apical and posterior segments did not appear reliable. Using selected segments, we were able to identify LAD disease in 84%, LCx disease in 49%, and RCA disease in 79% of documented significant stenosis, with specificity of 95%, 89%, and 88%, respectively. Coronary-artery disease could be detected in 95% of patients having more than 50% coronary-artery stenosis, with 93% specificity. In most cases, patients with two-vessels disease and three-vessel disease could not be distinguished from each other. Multiple-vessel disease suggested by segmental analysis of myocardial scinitgrams after exercise was confirmed artriographically in 88% of the patients, but 52% with scintigrams suggesting signle-vessel disease had, in fact, multiple-vessel disease.
