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At least 1,711 records · Page 95Linked to original sources
PubMed1989

[Evaluation of right ventricular systolic and diastolic properties using 81mKr scintigraphy with continuous infusion].

To evaluate right ventricular (RV) systolic and diastolic properties in patients with various heart diseases, RV volume curves obtained from 81mKr scintigraphy with continuous infusion were analyzed. The data were acquired in right anterior oblique position for five minutes, and from RV time activity curve and its first derivative curve, ejection fraction and peak ejection rate as systolic indices, and peak filling rate, time to peak filling and 1/3 mean normalized diastolic filling rate as diastolic indices were calculated. Ejection fraction in patients with dilated cardiomyopathy was lower than that in controls, but there was no difference in systolic indices among controls and patients with the other heart diseases. However, diastolic indices in patients with hypertrophic cardiomyopathy, patients with hypertensive heart disease, patients with dilated cardiomyopathy, patients with inferior myocardial infarction, and some patients with anteroseptal myocardial infarction were lower than those in controls. In conclusion, analysis of RV time activity curve by 81mKr scintigraphy with continuous infusion provides RV systolic and diastolic indices, which may permit evaluation of RV systolic and diastolic properties in various heart diseases.

Female↗
PubMedDate not supplied

The assessment of chronic venous obstructions by non invasive haemodynamic studies and imaging with Kr-81 m venography.

We study the sequelae of venous obstructions (from 15 days to several years after the thrombosis) by non invasive haemodynamic methods: Doppler velocimetry and leg plethysmography. We describe a simple physical model which permits the calculation of the leg outflow resistance from the venous occlusion plethysmography data. A radionuclide imaging of the veins is also recorded by a gammacamera during the perfusion of the limbs with Kr-81 m. This flexible technique appears suitable to analyse persistent ilio-femoro-popliteal obstructions. The results of the Doppler investigation are well related to the phlebograms. The outflow resistance of the leg depends mainly on the duration of the persistent obstruction. Recent obstructions are generally highly resistive but the level of the resistance is becoming close to normal with time (after two years).

Chronic Disease↗
PubMed1985

Distribution of arterial blood flow in human hepatic cancer during chemotherapy--examination by short-lived 81mKr.

Using the characteristics of short-lived radioisotope, 81mKr (half-life = 13 seconds), we studied the distribution of arterial blood flow of human hepatic cancers during intra-hepatic arterial chemotherapy. Sixteen patients with primary and metastatic cancer were catheterized into the hepatic artery during operation. 81mKr solution was continuously infused via the hepatic artery with the patient in the supine, upright, right-side down, and left-side down positions. The frontal and right-side images of the liver were taken with a scinticamera. The tumor/nontumor ratio of the hepatic arterial flow in the supine position was more than one in 14 of 15 patients. The patterns of arterial flow distribution of 81mKr in the four positions were compared. In 11 patients the tumor/nontumor ratio of one of the other positions was significantly higher than that of the supine position. We expect that this quantitative measurement will be a good indicator for evaluation of a drug's accessibility to the tumor in the first pass. Moreover, the choice of the most effective position for intra-arterial infusion chemotherapy by this test will be possible to increase the relative amount of drug reaching the tumor. This technique may be applicable mainly to short-term drug infusion.

Adenocarcinoma↗
PubMedDate not supplied

Cerebral hemodynamics in arteriovenous malformations: evaluation by single-photon emission CT.

Cerebral hemodynamics in six patients with supratentorial arteriovenous malformations (AVMs) were studied by using single-photon emission CT with three types of radioactive isotopes: N-isopropyl-p-[123I] iodoamphetamine, 81mKr, and 99mTc-RBC in order to determine the local cerebral blood flow and blood volume associated with these malformations. The AVMs were shown to have high flow while other areas of the brain, including the contralateral hemisphere, had variable areas of diminished perfusion. There was increased blood volume in the regions of AVMs, and poor but evenly distributed blood volume in the other regions. CO2 reactivity during hypocapnia was preserved throughout the brain except for the region of the AVMs. In large AVMs, the ischemic state surrounding the nidus was considered to be caused mainly by the cerebral steal phenomenon.

Adult↗
PubMed1977

Measurement of liver blood flow in the rat using an 85Krypton clearance technique.

A method for the measurement of liver blood flow (LBF) in rats has been developed by recording the clearance of 85Kr from the liver after injection of a solution of the gas into the portal vein. This technique provides a measure of tissue perfusion at a cellular level. The animal preparation was maintained in a stable haemodynamic and respiratory state for up to 4-3 h by careful fluid and anaesthetic control. Stability of the model was reflected by relative constancy of the LBF measured throughout the experiment in all of the animals studied. The mean LBF determined in six rats was 2-41+/-(s.d.) 0-50 ml/g/min.

Animals↗
PubMed1977

Liver tissue blood flow measured by 85Kr clearance in the anaesthetized rat before and after partial hepatectomy.

The changes in liver haemodynamics following partial hepatectomy (PH) were studied using an 85Kr clearance technique to measure perfusion in the livers of rats before and after both PH and sham operations. Post-operative measurements were made for 8 h following operation and also at 21 and 35 h, when uptake of tritiated thymidine into DNA is maximal in regenerating rat liver. Sham operation did not influence hepatic perfusion, arterial pressure or portal pressure. PH induced an early increase in perfusion of 293% in spite of a decrease in arterial blood pressure during the initial 4 h. The increase in perfusion lasted at least 8 h, had returned to normal values by 35 h, and was not explained solely by an observed elevation of portal pressure of 50% which returned to normal 5 h postoperatively. The total volume flow to the liver remnant after PH, however, was essentially the same as the flow to the liver before operation.

Animals↗
PubMed1986

Quantitative comparison of regional distributions of inhaled Tc-99m DTPA aerosol and Kr-81m gas in coal miners' lungs.

Regional distributions of deposited Tc-99m diethylenetriamine pentaacetate aerosol (DPTA) and of Kr-81m were compared in the upright lungs of 22 coal miners with nonembolic pulmonary disease. Pixel-by-pixel distributions of Kr-81m and DPTA corrected for lung volume, as well as DTPA/Kr-81m ratios, were determined by computer analysis in each lung and plotted against lung position. DTPA was preferentially deposited in the basal regions of 36/44 lungs. In the same lungs, Kr-81m was preferentially distributed in the apical regions of 18 lungs, bilaterally in six subjects. Similar DTPA and Kr-81m regional distributions throughout both lungs were obtained in only 11 (50%) subjects. No significant correlations were found between regional particle deposition and pulmonary function measurements. The effects of gravity-related lung pressure gradients and ventilation-related particle residence time on the deposition of DTPA may limit its usefulness when quantitative information is required to evaluate subtle changes in ventilation in nonembolic pulmonary patients and for basic studies of ventilation and perfusion.

Administration, Inhalation↗
PubMed1986

Regional distribution of ventilation assessed by Kr-81m scintigraphy employing temporal Fourier transform.

Temporal Fourier analysis was applied to Kr-81m ventilation scintigraphy to determine the amplitude (AMP1) and phase (PHA1) of the first harmonic of a single composite respiratory cycle and to compare regional patterns in subjects with obstructive pulmonary disease (COPD) and nonobstructed subjects. Six nonobstructed subjects, three subjects with small airway disease, six subjects with COPD, and one subject with restrictive disease were investigated. The mean value of the functional PHA1 image (PHA1m) correlated negatively with 1-second forced expiratory volume (FEV1) (r = -0.801, P less than .001), with %FEV1/FVC (r = -0.636, P less than .01) and maximum midexpiratory flow rate (FEF25-75%) (r = -0.723, P less than .002), and correlated positively with residual volume (r = 0.640, P less than .01). PHA1m values for the six subjects with COPD were significantly higher (t = 2.359, P less than .05) than for the ten nonobstructed subjects. Display of phase and amplitude functional images permits a visual evaluation of the regional distribution of ventilation to be made. Regional abnormalities of air flow were detected in obstructed subjects, and the presence of airway obstruction could be predicted. Dynamic ventilation imaging, therefore, appears to be a potentially useful noninvasive technique to assess lung impairment on a localized level.

Adult↗
PubMed1987

[Regional cerebral blood flow images of single photon emission computed tomography by N-isopropyl-p-[I-123] iodoamphetamine in patients with brain tumor].

Regional cerebral blood flow (r-CBF) was studied by single photon emission computed tomography (SPECT) using N-isopropyl-p-[I-123] iodoamphetamine (IMP) in order to evaluate CBF in patients with brain tumor. Total 27 studies were carried out in 20 patient, including 8 patients with meningioma, 3 with glioblastoma multiforme, 2 with oligoastrocytoma, and 7 with other intracranial tumors. All CBF images by IMP-SPECT were obtained by using a rotating gamma camera with dual heads. In the serial scans, each scan was started at 20 minutes, 2 hours and 6 hours after intravenous injection of I-123 IMP (3 mCi). The all IMP-SPECT images were compared with cerebral angiogram, X-ray CT (plain and/or enhancement), and images of Kr-81 m SPECT and Tc-99 m SPECT. In 5 patients (4 patients with meningioma and 1 with glioblastoma multiforme) this comparative study was performed before and after surgery to evaluate the r-CBF changes surrounding tumor. The abnormal lesion on X-ray-CT was identified as hot area on CBF image by IMP-SPECT in two cases with meningioma, and in 14 cases the lesion showed cold area. Totally 80% of cases showed abnormal findings on CBF images by IMP-SPECT. The cases which showed no abnormal findings on IMP-SPECT images included 1 case with meningioma which located in frontal base, 2 with small intracranial brain tumor which was smaller than 2 cm in diameter, and 1 with pituitary adenoma. On the IMP-SPECT images scanned 2 hours after injection, hot area, which was identified in two cases with meningioma on the images 20 minutes after injection, was changed into cold area.(ABSTRACT TRUNCATED AT 250 WORDS)

Amphetamines↗