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PubMed1988

Measurement of GFR with non-radioisotopic radio contrast agents.

The clearance of creatinine has been shown to overestimate GFR in patients with renal disease and in kidney transplant recipients. Alternate means for measuring GFR involve the use of constant infusion and, frequently, of radioisotopes. We report herein the measurement of GFR with the use of a radiocontrast agent (diatrizoate meglumine) injected subcutaneously with a small amount of epinephrine (0.05 ml of 1:1000). The concentrations of this marker of glomerular filtration in blood and in urine were measured with high-performance liquid chromatography. The results demonstrate that with this method of administration stable blood levels are observed for at least three hours. Furthermore, creatinine clearance overestimated GFR by 50% and by 68% in patients with renal disease and in renal transplant recipients, respectively. This method offers several advantages: 1) the use of commonly available and inexpensive materials; 2) obviates the need for the use of constant infusions; and 3) avoids the use of radioisotopes.

Adult↗

PubMed2001

Use of sonography and radioisotope renography to diagnose hydronephrosis in patients with spinal cord injury.

OBJECTIVE: To study the accuracy of sonography and radioisotope renography in detecting hydronephrosis in patients with spinal cord injury (SCI). DESIGN: Prospective, blinded comparison study. SETTING: Rehabilitation hospital affiliated with a medical college. PARTICIPANTS: One hundred and nine patients with SCI (21 women, 88 men) participated. INTERVENTIONS: Comprehensive urologic examinations including clinical evaluation, laboratory tests, intravenous urography (IVU), sonography, radioisotope renography (renal scan), voiding cystourethrography, and cystometry. The findings at sonography and renal scan were separately compared with the final diagnosis interpreted by IVU and clinical findings. MAIN OUTCOME MEASURES: Effective renal plasma flow, pyelocaliectasis, and positive and negative predictive value. RESULTS: A total of 235 kidneys were analyzed. Sonography correctly excluded the presence of hydronephrosis in 173 of 192 nonobstructed kidneys. Sonograms were interpreted as positive in 41 of 43 kidneys with documented hydronephrosis. Renal scan correctly excluded 161 nonobstructed kidneys. The renal scan detected 39 of 43 kidneys with hydronephrosis. The sensitivity of sonography was.96 with a specificity of.90. Renal scan reached a sensitivity of.91 with a specificity of.84. CONCLUSION: Sonography and renal scan are safe, sensitive, and specific for detecting hydronephrosis. Combined use of both methods appears to be a reliable alternative to IVU in the long-term follow-up for patients with SCI with neurogenic bladder dysfunction.

Adolescent↗

PubMed2001

Radioisotopic imaging allows optimization of adenovirus lung deposition for cystic fibrosis gene therapy.

Cystic fibrosis is a common, heriditary disease resulting from mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Airway transfer of the CFTR gene is a potential strategy to treat or prevent the lung pathology that is the main cause of morbidity and mortality. Among the vectors used for gene therapy, adenoviruses have shown their ability to transfer the CFTR gene to respiratory epithelial cells, using either instillation or nebulization. Our objective was to characterize the lung deposition of aerosolized adenovirus by quantitative radioisotopic imaging, the only noninvasive technique allowing in vivo quantitation of inhaled drugs. We first labeled an adenovirus expressing human CFTR with the gamma-emitting radioisotope, technetium 99m (99mTc), and determined the best labeling conditions to allow preservation of virus bioactivity. We then administered the radioaerosol to baboons, determined lung regional deposition of 99mTc-labeled adenovirus, and compared the expression of CFTR transcripts 3 and 21 days after inhalation. The expression of vector-encoded mRNA ranged from 4 to 22% with respect to the endogenous CFTR mRNA depending on the lung segments. Moreover, we have developed a model using 99mTc-DTPA (diethylenetriamine pentaacetic acid), which can be used, as an alternative to adenovirus, to determine the profile of lung deposition of the vector. This study demonstrates that scintigraphy is a useful technique to achieve optimization of gene administration to the airways.

Adenoviridae↗

PubMed2002

Clinically useful detection criteria for sentinel nodes in patients with breast cancer using a radioisotope technique.

BACKGROUND: The radioisotope technique has been used to identify sentinel nodes in patients with breast cancer. However, quantitative analysis of the radioactivity for detecting the sentinel nodes was not previously examined. In this study, we considered a clinically useful criterion for detecting sentinel nodes by a detailed analysis of 312 sentinel nodes using the radioisotope technique. PATIENTS AND METHODS: Patients with T1-2, N0 breast cancer were eligible for this study. The nodes with the highest radioactivity after injection of technetium-labeled tin colloids were identified as hot nodes. The radioactivities of the hot nodes and the background counts of the axillary basin were examined in order to establish new criteria for detecting the sentinel nodes. RESULTS: Between May 1997 and December 2001, 312 hot nodes were detected in 183 of 186 patients (98.4%). Since the false-negative rate for metastasis in hot nodes was only 2.1% (1/48), they could serve as sentinel nodes to predict the nodal status. However, there was a wide distribution of the hot nodes and the background in terms of absolute counts and a criterion for the sentinel nodes could not be established in terms of the absolute counts. When we adopted the criterion of sentinel nodes with a >/=100 count ratio in relation to the background, only 169 hot nodes (54.3%) met our definition. When the criterion of a >or=10 count ratio was adopted, all hot nodes met our definition and all other nodes remained non-sentinel nodes. CONCLUSION: The criterion for defining sentinel nodes in our method is a node with a >or=10 count ratio with respect to the background. It is recommended that an analysis based on such objective data should be investigated in order to provide surgeons with more accurate and clinically useful criteria for detecting sentinel nodes.

Adult↗

PubMed1986

Visualization of the left hepatic lobe during radioisotopic venography/lung imaging with technetium-99m MAA.

An unusual case of uptake of radioisotope by the liver during radioisotope venography/lung imaging with Tc-99m MAA is presented. Abnormalities in venous circulation of the lower extremities and abdomen, perfusion of the lung, and structure of the liver were detected, and correlated with other studies performed on a single patient. The mechanisms of uptake of Tc-99m MAA by the liver are discussed, with special attention paid to the mechanism believed to be present in this case.

Aged↗

PubMed1986

The role of the radioisotope phallogram in the investigation of vasculogenic impotence.

Patients complaining of impotence were investigated through a multi-disciplinary approach to define the factors involved. Radioisotope phallography was performed on all the patients using 99Tcm-labelled red blood cells (RBCs) and dynamic records of the variation in activity over the penis were obtained. During the course of the study an intravenous injection of a vasodilator (isoxsuprine HCl) was administered. An analysis of the data provided quantitative parameters for measuring the changes in penile blood flow and penile blood volume in response to the vasodilator injection. The results indicate that the radioisotope phallogram is useful both in the diagnosis of vasculogenic impotence and in indicating the method of treatment.

Adult↗

PubMed1990

Neonatal hypothyroidism: comparison of radioisotope and ultrasound imaging in 54 cases.

Fifty-four neonates with congenital hypothyroidism identified by the North East and North West Thames Regional hypothyroid screening programme between January 1985 and December 1987 were investigated with radioisotope (Tc99m) and ultrasound scans of the thyroid before treatment with 1-thyroxine was commenced. Compared with the radioisotope scans, ultrasound identified normally sited thyroid tissue in only 7 out of 10 cases, and ectopic thyroid tissue in only 5 out of 26 cases. Three out of 18 cases with no isotope uptake in the neck appeared to have normally sited tissue on ultrasound scan. We conclude that in our hands ultrasound of the neck is of only limited value in the assessment of young infants with congenital hypothyroidism.

Congenital Hypothyroidism↗

PubMed1976

Discussion paper: specific paralysis of the antitumor cellular immune response produced by growing tumors studied with a radioisotope footpad assay.

The kinetics of the antitumor cellular immune response of mice with progressively growing syngeneic tumors were determined in vivo using a quantitative radioisotopic footpad assay. A close correlation was found between the size of the tumor and the degree of the cellular immune response. An initial phase of cellular immune stimulation was followed by specific suppression and subsequent immunologic paralysis as the tumor grew larger. This immune paralysis was attributed to increased tumor load since a homogenate of an SV40 transformed fibrosarcoma injected intraperitoneally into tumor-immune mice specifically depressed their cellular immune response. The fraction of the tumor homogenate that brought about this depression was present in the high speed supernatant and pellet of a 3M KCl extract of the tumor. The specificity of the depression was determined in vivo by the radioisotopic footpad assay and in vitro by a 51Cr cytolysis assay. Unwashed spleen cells harvested from mice bearing large tumors were unreactive in a local adoptive footpad assay. However, reactivity could be restored by repeatedly washing the spleen cells.

Animals↗

PubMed1970

Standardized annular assay of dual radioisotopes on a well type sodium iodide crystal.

A procedure is described for the determination of the separate amounts of two gamma-emitting radioisotopes present simultaneously in large liquid volumes using an annular cell placed over a standard well-type crystal of sodium iodide and a reference source of (137)Cs. This sensitive technique is illustrated with particular reference to the double radioisotope urinary excretion test, using orally administered (57)CoB(12) bound to human gastric juice and (58)CoB(12) simultaneously, for the differentiation between patients with intrinsic factor deficiency and other causes of vitamin B(12) malabsorption.

Cesium Isotopes↗

PubMed1997

A comparative study of digoxigenin, 2,4-dinitrophenyl, and alkaline phosphatase as deoxyoligonucleotide labels in non-radioisotopic in situ hybridisation.

AIM: To determine the optimum form of labelling and the most efficient reporter molecule for non-radioisotopic in situ hybridisation (ISH). METHODS: Nine deoxyoligonucleotides complementary to histone mRNA were synthesised and labelled either enzymatically or during solid-phase synthesis with the reporter molecules digoxigenin, 2,4-dinitrophenyl (DNP), or alkaline phosphatase. Pooled deoxyoligonucleotide cocktails were then used in non-radioisotopic ISH detection of histone mRNA in human tonsil. Hybrid detection was by nitroblue tetrazoleum/5-bromo-4-chloro-3-indolyl phosphate colorimetric development. RESULTS: The use of a spacer in 3' enzymatic labelling and when labelling with alkaline phosphatase significantly increased ISH signal. The 3' and 5' labelling of oligonucleotides with triple DNP groups during solid-phase synthesis produced the strongest signal as determined by the highest cell signal intensity and shortest development time. CONCLUSIONS: 3' and 5' solid-phase labelling with triple DNP groups produced the best labelling for non-isotopic ISH using deoxyoligonucleotide cocktails.

2,4-Dinitrophenol↗

PubMed1975

Generalized pulmonary hyperinflation and Fallot's tetralogy in a neonate investigated by pulmonary physiological and radioisotopic methods.

An infant is described who presented a complex cardiopulmonary problem which was evaluated with the help of new physiological techniques. the infant was born at term after an emergency Caesarian section for fetal distress and was found to have meconium aspiration. He remained persistently tachypnoeic and hypoxic despite high ambient oxygen. Chest radiography suggested cystic lesions at the lung bases, and lung function tests confirmed hyperinflation with delayed nitrogen washout. In addition the child had signs of Fallot's tetralogy, and this diagnosis was confirmed by cardiac catheterization. Because of persistent hypoxia and tachypnoea disproportionate to the cardiac condition, the possibility of localized lung disease was considered. Regional lung function tests were carried out in the neonatal period and again at six months of age useing radioisotopic 13N given by both inhalation and injection. These studies showed gross ventilation/perfusion imbalance in the lungs, particularly marked at the bases, but with enough generalized abnormality to preclude the possibility of surgical intervention. The principles of the measurement of lung mechanics in the newborn by whole-body plethysmography, nitrogen washout, and regional radioisotopic spirometry are outlined. The particular value of these techniques in the evaluation of complex disorders is discussed, especially where both cardiac and pulmonary abnormalities are present.

Airway Resistance↗

PubMed1983

Work in progress: radioisotopic evaluation of gastroplasty patients.

Radioisotopic gastric emptying studies, using technetium-99m-sulfur-colloid-labeled egg, were performed in 14 patients who had undergone gastroplasty. The radioisotopic method was found to be a good quantitative indicator of the amount of solids that empty from the stomach and a useful tool in the longterm follow-up of gastroplasty patients. It was particularly helpful in evaluating the efficacy of surgery in patients with poor postsurgical weight reduction.

Adult↗

PubMed1979

Hydrocephalus after subarachnoid bleeding. A correlation of clinical findings, the results of radioisotope Cisternography and computer-assisted tomography.

Out of a group of patients suffering from a spontaneous subarachnoid hemorrhage 27 patients were checked by computer-assisted tomography (CAT), 23 patients by radioisotope cisternography, and 21 patients by both diagnostic procedures. The results were correlated with the clinical observations. The flow of the CSF was normal in 7 patients (30.43%), and pathological in 16 patients (69.56%). Of the 27 patients checked by CAT, 23 (85.18%) showed a ventricular dilatation, which in 17 patients (62.96%) was not connected with a corresponding increase of the cisterns of the convexity. The clinical symptoms of hydrocephalus, the degree of impairment of the circulation of the CSF determined by radioisotope cisternography and the ventricular diameter as determined by CAT correlated well.

Adolescent↗

PubMed1985

Non-invasive radioisotopic evaluation of placental blood flow.

The authors have evaluated placental blood flow using a non-invasive radioisotopic approach. The procedure involves the intravenous administration of 113mIn and the technique is a modified version of a previously reported method for a non-diffusive tracer kinetics analysis. The method is presented in detail and its performance is evaluated in 17 normal and 32 pathologic pregnancies (19 intrauterine growth retarded patients; 7 patients with iso-Rh immunization; 5 patients with gestational diabetes, and 1 pregnancy with extensive fetal malformation which was not included in any group). The normal pregnancies showed a flow index of 5.34 +/- 1.64 (1 SD) units compared to the pathological pregnancies value of 2.73 +/- 0.73 (1 SD) units (p less than 0.001). The conclusions drawn are: (1) the method is very well suited to clinical evaluation of placental blood flow; (2) the evaluation of placental blood flow cannot be directly equated with fetal development as it is not its only determinant, and (3) no other independent test to evaluate the radioisotopic study in terms of accuracy exists.

Adult↗

PubMed1975

Radioisotopic bolus technique as a test to detect circulatory deficit associated with cerebral death. 142 studies on 80 patients demonstrating the bedside use of an innocuous IV procedure as an adjunct in the diagnosis of cerebral death.

A portable radioisotopic technique was developed to demonstrate cerebral circulatory deficit, as part of a collaborative study to define and diagnose cerebral death simply and rapidly, in comatose, apneic patients with electrocerebral silence. The method involves an intravenous injection of 2mCi of 99mTcO4, and recording time/activity curves over the cranial cavity and a femoral artery simultaneously, using twin probe radioisotope detector equipment. Eight comatose, apneic patients had 142 studies in conjunction with clinical electroencephalographic and other laboratory evaluations. The results indicate that the absence of a bolus tracing from the head, as contrasted to the usual bolus seen is indicative of significant circulatory deficit to the cerebrum. This test may be used as an adjunct in confirming the diagnosis of cerebral death. A normal bolus tracing should be simultaneously observed over a femoral artery and this is used as a control. The method is safe and simple and offers significant information about the irreversibility of cerebral blood flow. Although further studies are indicated, the method appears to be most promising as a fundamental bedside laboratory test in the diagnosis of cerebral death in conjunction with other clinical and laboratory criteria.

Adult↗

PubMed1978

Evaluation of left ventricular function (ejection fraction and segmental wall motion) by single pass radioisotope angiography.

Changes in ejection fraction (EF) and segmental wall motion (SWM) have been shown to be sensitive indicators of left ventricular (LV) function. This information is only obtainable by contrast angiography or gated blood pool scans. Gated studies assume a fixed geometry for the LV for EF determinations, are lengthy and limited primarily to the LAO projection. We correlated contrast and Tc-99m pertechnetate angiograms by singl pass radioisotope angiography (immediately preceding the contrast study) in 12 patients. EF was calculated from the LV time/activity curve and values ranged from .21 to .72. Angiographic correlation yielded r = 0.97. Regional LV wall motion was evaluated by dividing a summated cardiac cycle into 16 frames and dynamically and sequentially displaying these frames. Regional wall motion evaluation of four LV quadrants correlated well with angiography (r = 0.97). For quantitation these images were divided into four anterior and four inferior segments and the areas of respective segments were compared and expressed as a shortening fraction. SWM compared favorably with angiographic determinations (r ranged from 0.70 to 0.99). Thus, single pass radioisotopic determinations of EF and SWM in the RAO projection correlated well with the angiographic values and provide essential quantitative information of LV function otherwise unobtainable at the bedside.

Adult↗

PubMed1996

Early detection of lung involvement in lysinuric protein intolerance: role of high-resolution computed tomography and radioisotopic methods.

Pulmonary disease of unknown etiology is a potentially fatal complication in patients with lysinuric protein intolerance (LPI), an autosomal recessive disorder caused by the defective transport of cationic amino acids. Lung involvement was investigated in nine Italian LPI patients through pulmonary function tests and lung imaging studies consisting of conventional chest radiography, high-resolution computed tomography (HRCT), and perfusion and ventilation scintigraphy. One 10-yr-old patient died of severe respiratory insufficiency from alveolar proteinosis. All of the remaining patients were asymptomatic at the time of the study, although HRCT scans revealed signs of lung involvement defined by the presence of acinar nodules, inter- and/or intralobular thickening of the interstitial septa, and subpleural cysts in five of the patients. Radioisotope studies showed an uneven distribution of perfusion and ventilation, and confirmed the presence of segmental and/or diffuse pulmonary functional defects. No abnormalities of pulmonary function were evident, and answers to a questionnaire excluded primary coexisting lung disease. In patients with LPI, including those without clinical and functional impairment, HRCT and radioisotopic studies appear to be the most sensitive methods for the early diagnosis of lung disease and correct assessment of its progression.

Adult↗

PubMed1991

The interchangeability of radioisotope and X-ray based measurements of bone mineral density.

Lumbar spine and femoral neck bone mineral density (BMD) were measured with a Novo radioisotope based dual photon densitometer and with a Lunar X-ray densitometer in 94 subjects attending a Metabolic Bone Disease Clinic. There was a strong correlation between results obtained from each machine for the same skeletal site. The correlation coefficients for the spine and femoral neck were 0.97 and 0.88, respectively. The differences between results from each machine were normally distributed with a mean bias of 37.5% for the spine and 27.8% for the femur, which arise principally from differences in machine calibration. In each case the BMD was greater when measured by X-ray absorptiometry. The range for the bias was approximately 25-50% for the spine and 10-45% for the femoral neck. The results from these two machines are not interchangeable. When subjects who are participating in long term studies using a radioisotope densitometer are transferred to an X-ray densitometer, an individual conversion factor must be measured at each site for each subject.

Absorptiometry, Photon↗