Search PubMed⌕ Search

Biomedical subjects

S Treves

Publications and source records attributed to S Treves.

At least 91 records · Page 5Linked to original sources
PubMed1982

Radionuclide angiocardiography in evaluation of patients after repair of transposition of the great arteries.

The ability of first pass radionuclide angiocardiography to detect and quantitate residual intracardiac shunts and systemic venous obstruction after repair of transposition of the great arteries was evaluated in 29 children. Information from radionuclide scans was compared with data obtained during cardiac catheterization. Three children had a residual right to left shunt detected with both methods. There was good agreement between radionuclide and catheterization quantitation of left to right shunt in the nine patients with a residual defect, five of whom had significant shunting. Nineteen patients with signs suggesting superior vena caval obstruction were evaluated with both radionuclide and catheterization methods. In eight, complete obstruction was detected with both techniques; in one additional patient, partial obstruction was found on catheterization only. One of six patients evaluated for possible inferior vena caval obstruction was identified with both techniques. In the group as a whole, information obtained with radionuclide angiography correlated well with cardiac catheterization data in evaluation of residual shunts and obstruction to systemic venous return.

Adolescent↗
PubMed1982

Low radiation iridium 191m radionuclide angiography: detection and quantitation of left-to-right shunts in infants.

Radionuclide angiography using iridium 191m was carried out in 34 premature infants and young children for detection and quantitation of left-to-right shunts. Ir-191m has a physical half-life of 4.96 seconds and can be imaged with conventional gamma scintillation cameras. The whole body radiation absorbed dose from Ir-191m is 3.5 mrad/mCi, which is about 40 times less radiation than with technetium 99m. Other advantages of Ir-191m include high photon flux for improved imaging and the possibility of multiple studies within a short period of time without background. Nine patients had simultaneous measurement of pulmonary-to-systemic flow ratio by Ir-191m angiography and oxymetry during cardiac catheterization; the correlation coefficient was 0.90. Radionuclide angiography with Ir-191m is a method with virtually no risk, rapid, accurate, and reproducible, and is ideally suited for the evaluation of left-to-right shunts in small children.

Angiography↗
PubMed1982

Assessment of mandibular growth by skeletal scintigraphy.

Accurate assessment of facial skeletal growth remains a major problem in craniomaxillofacial surgery. Current methods include 1) comparisons of chronologic age with growth histories of the patient and the family, 2) hand-wrist radiographs compared with a standard, and 3) serial cephalometric radiographs. Uptake of technetium-99m methylene diphosphonate into bone is a reflection of current metabolic activity and blood flow. Therefore, scintigraphy with this radiopharmaceutical might serve as a good method of assessing skeletal growth. Thirty-four patients, ranging in age from 15 months to 22 years, who were undergoing skeletal scintigrams for acute pathologic conditions of the extremities, were used to develop standards of uptake based on age and skeletal maturation. The results indicate that skeletal scintigraphy may be useful in evaluation of mandibular growth.

Adolescent↗
PubMed1982

Radionuclide assessment of the effects of chest physical therapy on ventilation in cystic fibrosis.

This study assesses the use of krypton 81m scintigraphy as a measurement tool in evaluating the effectiveness of bronchial drainage with percussion and vibration on peripheral ventilation in patients with cystic fibrosis. Ten patients with cystic fibrosis participated. Each patient underwent a krypton 81m ventilation study and traditional pulmonary function tests. Forty-five minutes later, these studies were repeated before and after a chest physical therapy treatment. Each patient acted as his own control. All krypton 81m scintiscans were recorded and analyzed visually and numerically using a digital computer to assess distribution of ventilation. Visual analysis of the scintiscans indicated individual variation in treatment response: in some patients ventilation improved with therapy; in others, no change was noted; still others had changes independent of treatment. Numerical data derived from the scintiscans and pulmonary function tests showed no important differences among the three studies of each patient. Airway abnormalities characteristic of cystic fibrosis, progression of the disease, sputum production, or a combination of these factors may account for the individual variation in response to treatment. Krypton 81m scintigraphy is a reliable measure of regional ventilation and should be useful for assessing the efficacy of chest physical therapy because of the consistent, high quality visual data retrieved.

Adolescent↗
PubMed1982

Early scintographic diagnosis of bone stress and fractures in athletic adolescents.

A study of radionuclide bone scintigraphy in adolescents was conducted to evaluate the pattern of stress-related abnormalities and their correlation with both symptoms and roentgenography. In 26 episodes of stress-related abnormal scintigraphy, 12 (46%) had a multifocal pattern of abnormalities. Forty foci were identified by scintigraphy, with 11 (28%) exhibiting abnormal roentgenograms. These multiple abnormalities were frequently unsuspected clinically, and studies limited to symptomatic areas would have failed to detect them. It is recommended that patients with stress-related symptoms be screened utilizing radionuclide bone scintigraphy to facilitate the early detection of abnormalities in bone prior to the development of cortical disruption, thereby preventing increased morbidity and possible disabling sequelae.

Adolescent↗
PubMed1982

Splenic scintigraphy using Tc-99m-labeled heat-denatured red blood cells in pediatric patients: concise communication.

Ten children underwent splenic imaging with heat-denatured red blood cells labeled with technetium-99m (Tc-99m DRBC). The presenting problems included the heterotaxia syndrome, recurrent idiopathic thrombocytopenic purpura following splenectomy, mass in the left posterior hemithorax, and blunt abdominal trauma. In nine patients, the presence or absence of splenic tissue was established. A splenic hematoma was identified in the tenth patient. All patients were initially scanned with Tc-99m sulfur colloid (Tc-99m SC), and were selected for Tc-99m DRBC scintigraphy only after the results of the SC scans failed to establish the clinical problem beyond doubt. The availability of kits containing stannous ions, essential for efficient and stable labeling of red blood cells with Tc-99m and requiring only a small volume of blood, make splenic scintigraphy in children a relatively simple and definitive diagnostic procedure, when identification of splenic tissue is of clinical importance.

Abdominal Injuries↗
PubMed1981

Suctioning of upper airway meconium in newborn infants.

To compare the efficacy of bulb and catheter suctioning of upper airway meconium in neonates, meconium labeled with technetium Tc 99m sulfur colloid was injected into the trachea and oropharynx of anesthetized kittens. Human birth conditions were simulated by an inflated blood pressure cuff around the thorax and abdomen of the animals and by partial degassing of the lungs before introduction of meconium. Distribution of meconium in the upper airway was determined by scintigraph. Catheter suction brought about a 43% decrease in radioactivity while there was only a 1% decrease after bulb suctioning. Meconium may persist in the trachea for more than 20 minutes after introduction, indicating the desirability of continued suctioning efforts in neonates with meconium aspiration syndrome. The relative safety of the two techniques was not assessed.

Airway Obstruction↗
PubMed1981

Quantitative thallium-201 myocardial imaging in assessing right ventricular pressure in patients with congenital heart defects.

Thallium-201 myocardial scintigraphy was performed in patients with congenital heart defects to determine whether, by quantification of right ventricular isotope uptake, one could assess the degree of right ventricular hypertrophy and so predict the level of right ventricular pressure. A total of 24 patients ranging in age from 7 months to 30 years was studied; 18 were studied before corrective surgery and six after operation. All but three had congenital heart defects which had resulted in pressure and/or volume-overload of the right ventricle. At routine cardiac catheterisation, 20 microCi/kg thallium-201 as thallous chloride was injected through the venous catheter and myocardial images were recorded in anterior and left anterior oblique projections; these were subsequently analysed quantitatively and qualitatively. Insignificant right ventricular thallium-201 counts judged as being less than 1 per cent of the injected dose or less than 0.3 of the left ventricular counts were present in six patients all with right ventricular peak systolic pressure less than 30 mmHg. In the remaining 18 patients there was a good correlation between the right ventricular/left ventricular peak systolic pressure ratio and the right ventricular/left ventricular thallium-201 counts ratio. All patients with right ventricular/left ventricular peak systolic pressure less than 0.5 had right ventricular/left ventricular thallium-201 counts less than 0.4. Qualitative evaluation of right ventricular isotope intensity proved helpful mainly in distinguishing the patients with right ventricular pressures at or above systemic levels. Thus quantitative analysis of myocardial imaging with thallium-201 is of use clinically in patients with congenital heart defects, in assessing the severity of pulmonary stenosis or the presence of pulmonary artery hypertension.

Adolescent↗
PubMed1981

Renal growth after transplantation: infant kidney received by adolescent.

Renal growth and function were studied in a sixteen year old recipient of a renal transplant from a 16 month old cadaveric donor. Within one month, as measured by sequential inulin and creatinine clearances, glomerular filtration rate was 40 ml/min, which was more than 6 times the estimated pretransplant clearance. Ultrasound of the transplanted kidney revealed longitudinal growth from 7 cm at transplant to 11.5 cm by 8 weeks post-transplant. Radionuclide renal scintiphotography confirmed rapid functional and dimensional growth. There was no evidence of rejection, obstruction, or other complications during the time the allograft rapidly increased in size. Thus this case demonstrates a remarkable capacity of the human kidney to hypertrophy rapidly.

Adolescent↗
PubMed1980

Radionuclide angiography in congenital heart disease.

Cardiac nuclear imaging (radionuclide angiography, electrocardiographic gated ventriculography and myocardial scintigraphy) provides structural and functional information simultaneously. This method extracts accurate quantitation of cardiovascular hemodynamics and unique information regarding myocardial perfusion. It is a reliable and relatively simple and atraumatic technique because the only discomfort to the patient is a simple intravenous injection. These studies are carried out rapidly in out- or inpatients. Radionuclide angiography is ideal also to assess the effect of exercise, oxygen or drugs on cardiac function. The radiation exposure associated with current nuclear imaging is within the range of common radiographic procedures and many times lower than that of cardiac catheterization. The use of newer radionuclides such as iridium-191m with a physical half-life of 4.96 seconds will result in a dramatic decrease in the radiation exposure to patients undergoing radionuclide angiography. Also, newer and smaller computerized gamma cameras will provide studies of improved spatial resolution and accuracy. The future of pediatric applications of cardiac nuclear imaging is bright.

Cardiac Catheterization↗
PubMed1980

Autoregulation in rats with transplanted supernumerary kidneys.

Autoregulation of mammalian renal function is implicit in the fact that a few hours after removal of one kidney the activity of the intact nephrons in the other kidney suddenly increases, both in glomerular filtration and tubular reabsorption. There follows a slower but easily measured increase in renal mass-compensatory hypertrophy in each residual nephron. That response to a reduction of nephrons has been well studied, but the adaptation of normal renal function to additional nephrons could not be tested until microsurgical techniques made it possible to transplant one or two additional kidneys into normal rats. We report here sequential measurements of the total renal function of rats with three and four kidneys. Our results indicate that autoregulation maintains total renal function at normal levels in spite of a doubling in the number of nephrons and apparent renal mass.

Animals↗
PubMed1980

Pulmonary scintigraphy in pediatrics.

Pulmonary radionuclide studies in children provide reliable information on regional lung perfusion and ventilation. They are easily and safely performed and they do not usually require full patient cooperation. Their clinical indications and applications are not as well defined as and frequently differ from those in pulmonary disorders of the adult patient. Radiation exposures resulting from radionuclide pulmonary examinations are well within acceptable limits set up for a variety of radiologic diagnostic procedures. Our lung scanning experience with a spectrum of congenital and acquired cardiopulmonary diseases is presented and the contribution of the radionuclide methods to the specific problems facing the pediatrician or the surgeon is discussed.

Adolescent↗
PubMed1980

Detection and quantitation of cardiovascular shunts with commonly available radionuclides.

Detection and quantitation of shunts can be done accurately, rapidly, and safely using radionuclide techniques. The most frequent use of radionuclides in the evaluation of shunts is first-pass radionuclide angiography for the detection and quantitation of left-to-right shunts. Thallium-201 myocardial scintigraphy is useful in the evaluation of right ventricular overload secondary to left-to-right shunting. Radionuclide angiography has applications for premature and newborn infants with patent ductus arteriosus and respiratory distress, older children with unexplained heart murmur, and in the postoperative evaluation of patients undergoing cardiovascular surgery.

Heart↗
PubMed1980

The scintigraphic evaluation of hip pain in children.

Thirty-eight patients (28 boys and 10 girls) with hip pain were referred for bone scans. In 7 of 8 with Legg-Calvé-Perthes disease, there was decreased uptake of the radiopharmaceutical in the proximal femoral epiphysis; the other had radiographic evidence of joint destruction and showed increased uptake. Three patients with abnormal scans had normal x-rays with Gaucher's disease, toxic synovitis, and Legg-Calvé-Perthes disease, respectively. One patient with avascular necrosis associated with steroid therapy had increased uptake, possibly due to revascularization. Those with toxic synovitis had either normal bone scans for showed a slight generalized increase around the hip joint. It is speculated that the latter may represent those who later present with Legg-Calvé-Perthes. The bone scan is useful for the early detection of Legg-Calvé-Perthes disease in patients with hip pain.

Adolescent↗