sodium-pertechnetate-tc-99m and Lung-Diseases

This paper describes the recent advances in technical and analytical methods in pulmonary ventilation SPECT studies, including a respiratory-gated image acquisition of Technetium-99m (99mTc)-labeled Technegas SPECT, a fusion image between Technegas SPECT and chest CT images created by a fully automatic image registration algorithm, and a three-dimensional (3D). display of xenon-133 (133Xe) gas SPECT data, and new analytical approaches by means of fractal analysis or the coefficient of variations of the pixel counts for Technegas SPECT data. The respiratory-gated image acquisition can partly eliminate problematic effects of the SPECT images obtained during non-breath-hold. The fusion image is available for routine clinical use, and provides complementary information on function and anatomy. The 3D displays of dynamic 133Xe SPECT data are helpful for accurate perception of the anatomic extent and locations of impaired ventilation, and the assessment of the severity of ventilation abnormalities. The new analytical approaches facilitate the objective assessment of the degrees of ventilation abnormalities.

Topics: Adult; Aged; Female; Humans; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Lung; Lung Diseases; Male; Middle Aged; Pulmonary Ventilation; Radiopharmaceuticals; Respiration Disorders; Sodium Pertechnetate Tc 99m; Subtraction Technique; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Xenon Radioisotopes

Lung scintigraphy is primarily used to diagnose pulmonary embolism. Ventilation imaging is often performed using (99m)Tc-DTPA or Technegas, an ultrafine dispersion of (99m)Tc-labeled carbon. Despite the common use of these radioaerosols, they have not been compared in an intraindividual study, and not with ventilation-perfusion (V/P) SPECT. The aim of the present head-to-head study was to systematically investigate differences in ventilation studies performed with (99m)Tc-diethylenetriaminepentaacetate (DTPA) and Technegas.. Sixty-three patients, 28 without and 35 with obstructive lung disease, were examined with V/P SPECT using both (99m)Tc-DTPA and Technegas. V/P SPECT images were randomized and assessed independently by 2 masked physicians according to a predefined scoring system. A paired comparison was performed using the Wilcoxon signed-rank test.. In both obstructive and nonobstructive disease, the overall unevenness of radiotracer deposition and the degree of central deposition were more pronounced in (99m)Tc-DTPA than Technegas studies. Because of better peripheral penetration, the extent of reverse mismatch was less when Technegas was used. Additionally, in obstructive disease, the degree of focal deposition in distal airways was more pronounced with (99m)Tc-DTPA. Mismatched perfusion defects were more frequently found with Technegas in obstructive disease.. This intraindividual comparative study shows that Technegas is the preferred radioaerosol, particularly in obstructive disease.

Topics: Aged; Female; Humans; Image Processing, Computer-Assisted; Lung; Lung Diseases; Lung Diseases, Obstructive; Male; Middle Aged; Pulmonary Disease, Chronic Obstructive; Pulmonary Embolism; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Pentetate; Tomography, Emission-Computed, Single-Photon

In this study, respiratory-gated ventilation and perfusion single-photon emission tomography (SPET) were used to define regional functional impairment and to obtain reliable co-registration with computed tomography (CT) images in various lung diseases. Using a triple-headed SPET unit and a physiological synchroniser, gated perfusion SPET was performed in a total of 78 patients with different pulmonary diseases, including metastatic nodules (n = 15); in 34 of these patients, it was performed in combination with gated technetium-99m Technegas SPET. Projection data were acquired using 60 stops over 120 degrees for each detector. Gated end-inspiration and ungated images were reconstructed from 1/8 data centered at peak inspiration for each regular respiratory cycle and full respiratory cycle data, respectively. Gated images were registered with tidal inspiration CT images using automated three-dimensional (3D) registration software. Registration mismatch was assessed by measuring 3D distance of the centroid of the nine selected round perfusion-defective nodules. Gated SPET images were completed within 29 min, and increased the number of visible ventilation and perfusion defects by 9.7% and 17.2%, respectively, as compared with ungated images; furthermore, lesion-to-normal lung contrast was significantly higher on gated SPET images. In the nine round perfusion-defective nodules, gated images yielded a significantly better SPET-CT match compared with ungated images (4.9 +/- 3.1 mm vs 19.0 +/- 9.1 mm, P<0.001). The co-registered SPET-CT images allowed accurate perception of the location and extent of each ventilation/perfusion defect on the underlying CT anatomy, and characterised the pathophysiology of the various diseases. By reducing respiratory motion effects and enhancing perfusion/ventilation defect clarity, gated SPET can provide reliable co-registered images with CT images to accurately characterise regional functional impairment in various lung diseases.

Topics: Adult; Aged; Aged, 80 and over; Female; Gated Blood-Pool Imaging; Humans; Imaging, Three-Dimensional; Lung Diseases; Male; Middle Aged; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Subtraction Technique; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The functional mechanism of lung mosaic computed tomography attenuation (MCA) in pulmonary vascular disease (PVD) and obstructive airway disease (OAD) has not yet been fully clarified.. To clarify the mechanism of MCA in these diseases by assessing the relationship between regional lung function and CT attenuation change at MCA sites with the use of automated deep-inspiratory breath-hold (DIBrH) perfusion single-photon emission computed tomography (SPECT)-CT fusion images and non-breath-hold Technegas SPECT.. Subjects were 42 PVD patients (31 pulmonary thromboembolism, four primary/two secondary pulmonary hypertension, and five Takayasu arteritis), 12 OAD patients (five acute asthma, four obliterative bronchiolitis, and three bronchiectasis), and 12 normal controls, all of whom had MCA on DIBrH CT. The relationship between regional lung function and CT attenuation change at the lung slices with MCA was assessed using DIBrH perfusion SPECT-CT fusion images and non-breath-hold Technegas SPECT. The severity of perfusion defects with or without MCA was quantified by regions-of-interest analysis.. On DIBrH CT and perfusion SPECT, in contrast to no noticeable CT attenuation abnormality and fairly uniform perfusion in controls, 60 MCA and 274 perfusion defects in PVD patients, and 18 MCA and 61 defects in OAD patients were identified, with a total of 77 ventilation defects on Technegas SPECT in all patients. SPECT-CT correlation showed that, throughout the 78 MCA sites of all patients, lung perfusion was persistently decreased at low CT attenuation and preserved at intervening high CT attenuation, while lung ventilation was poorly correlated with CT attenuation change. The radioactivity ratios of reduced perfusion and the intervening preserved perfusion at the 78 perfusion defects with MCA were significantly lower than those at the remaining 257 defects without MCA (P<0.0001).. Although further validation is required, our results indicate that heterogeneous pulmonary arterial perfusion may be a dominant mechanism of MCA in PVD and OAD.

Topics: Adult; Aged; Case-Control Studies; Female; Humans; Image Interpretation, Computer-Assisted; Inhalation; Lung Diseases; Male; Middle Aged; Radiopharmaceuticals; Respiratory Function Tests; Retrospective Studies; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

To characterize the accuracy of an ultrafine 99m-technetium-labeled carbon dry aerosol for use in assessment of regional ventilation in calves with pulmonary dysfunction.. 7 Belgian White and Blue calves.. The ultrafine aerosol was assessed by comparing deposition (D) images with ventilation (V) images obtained by use of 81 m-krypton (81mKr) gas via D-to-V ratio (D:V) image analysis in calves during spontaneous breathing (SB) and during experimentally induced pulmonary dysfunction (ePD).. Mismatching index (LrTot) calculated on the D:V images revealed a good match (LrTot, 0.96 +/- 0.01) between D and V distribution patterns in calves during SB. Calculation of the ultrafine aerosol penetration index relative to 81mKr (PIRel) revealed preferential distribution of the ultrafine aerosol in lung parenchyma (PIRel, 1.13 +/- 0.11). In ePD, heterogeneity in the D:V distribution was observed (LrTot, 0.78 +/- 0.10) as a result of ultrafine aerosol particles impaction in airways as indicated by PIRel (0.66 +/- 0.16) and a proportion of pixels more radioactive in D images, compared with V images, that was located in the central part of the lung (475 +/- 77% in ePD vs 32.8 +/- 5.7% in SB). However, this central deposition did not prevent visual examination of the entire ventilated lung.. The ultrafine aerosol appears suitable for use in examination of ventilated parts of lungs of cattle, even those with impaired pulmonary function. However, airway impaction of ultrafine aerosol particles impedes the quantification of regional ventilation in cattle with abnormal lung function.

Topics: Aerosols; Animals; Cattle; Cattle Diseases; Image Processing, Computer-Assisted; Krypton Radioisotopes; Lung Diseases; Radionuclide Imaging; Respiratory Function Tests; Sodium Pertechnetate Tc 99m; Statistics, Nonparametric

The exact amount of drug deposited in the respiratory and gastrointestinal tract in children with airway obstruction, when delivered from a metered-dose inhaler (MDI) via a spacer with mask, and its distribution in children with airway obstruction, are unknown.. We studied 15 children, using salbutamol labeled with technetium 99m. Each patient was imaged with a gamma-camera immediately after one puff of labeled salbutamol was administered via a spacer with mask. Drug deposition was then analyzed to measure the distribution of the labeled spray in the oropharynx, the lungs, the stomach, and the spacer with mask (Aerochamber) itself.. Fifteen infants and children (mean age, 21 months (range, 3 months to 5 years); mean weight, 9.3 kg (range, 3.2 to 15 kg)) were studied. Mean aerosol deposition was 1.97% +/- 1.4% in the lungs, 1.28% +/- 0.77% in the oropharynx, and 1.11% +/- 2.4% in the stomach. The remainder was trapped in the spacer. Lung imaging after inhalation from an MDI via a spacer showed widespread deposition of the drug in central and peripheral intrapulmonary airways. In two adult volunteers the deposition after one puff of the same radiolabeled drug, inhaled from an MDI via a spacer with a mouthpiece, was 19% in the lungs and 2% in the stomach.. Infants and toddlers with obstructive lung disease can be reliably and safely treated with inhaled medication administered with an MDI via a spacer with mask. The doses of a drug given from an MDI to infants and toddlers when a spacer with mask is used are not yet well defined but should be higher than the currently recommended doses, perhaps as much as an adult dose.

Topics: Administration, Inhalation; Adrenergic beta-Agonists; Adult; Albuterol; Child, Preschool; Drug Delivery Systems; Female; Humans; Infant; Lung Diseases; Male; Nebulizers and Vaporizers; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Treatment Outcome

99mTc-DTPA aerosol permeates the alveolar membrane by an intercellular pathway. Measurement of the clearance rate of 99mTc-DTPA aerosol is useful for assessing injury of the lung epithelium. Pertechnegas (P-gas) is also used to assess epithelial permeability, but its clearance is too rapid to evaluate lung epithelial permeability. The aims of this study were first to generate 99mTc-DTPA fine aerosol (D-gas), second to characterize D-gas by radiochromatography and an in vivo study in the rat, and third to investigate the clinical significance of D-gas in comparison with 99mTc-DTPA aerosol and P-gas. We generated D-gas in a chamber with an atmosphere of 3% oxygen and 97% argon inside the Technegas Generator. The clearance half-time of D-gas was 19.8 +/- 4.0 min in eight normal non-smoker subjects, 12.0 +/- 2.8 min in four smoker subjects, and 31 +/- 11.2 min in three with idiopathic interstitial pneumonia (IIP). In radiochromatography, the development of D-gas was the same as that of P-gas and different from that of 99mTc-DTPA solution. In the in vivo study using a rat, the distribution of intravenously injected D-gas solution was the same as that of 99mTcO4-, but different from that of 99mTc-DTPA solution. These results suggest that 99mTc-DTPA separates to free 99mTcO4- in the chamber of the Technegas Generator and that D-gas behaves in the same manner as P-gas. In conclusion, D-gas has no clinical significance for the assessment of epithelial permeability.

Topics: Aerosols; Animals; Cell Membrane Permeability; Epithelium; Half-Life; Humans; Lung Diseases; Pulmonary Alveoli; Radionuclide Imaging; Rats; Rats, Wistar; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Pentetate

Exactly how the pulmonary distribution of inhaled radioactive gas and Technegas, or ultra-small aerosol particulates, differs from each other, is still uncertain. The authors compared the distribution of inhaled Kr-81 m gas and Technegas in the lungs at total lung capacity in 13 control subjects with no clinical conditions and 13 patients with various chest diseases. In normal lungs, there was no difference in the distribution ratios in the right and left lungs between inhaled Kr-81m gas and Technegas. However, there was a significant difference in the lungs of patients with pulmonary disease. Technegas tended to deposit more in the lung bases than did Kr-81m gas. Despite these statistical differences, they were visually, or qualitatively, similar. From a practical and clinical standpoint, Technegas seems to be useful as an inhalation agent, unless quantitative analyses are required.

Topics: Administration, Inhalation; Adult; Female; Graphite; Humans; Krypton Radioisotopes; Lung; Lung Diseases; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Tissue Distribution; Total Lung Capacity

99mTc-technegas (99mTc-gas), which consists of fine particles, is produced in carbon crucibles burned at 2500 degrees C. On this study, the particle size of 99mTc-gas was measured and the pulmonary distribution of 99mTc-gas was assessed in 28 patients with various pulmonary diseases. Most particles were 5-30 nm in diameter as determined by electron microscopy. In a clinical study, about 37 MBq of 99mTc-gas was inhaled three times during deep breathing in a sitting position. In a comparative study with radioactive inert gases (133Xe, 81mKr), 99mTc-gas showed a similar distribution to the inert gas in most patients, although some with obstructive disease showed hot spots in the lung fields. In patients with severe obstructive change, marked deposits of 99mTc-gas was noted in the central airways, but 99mTc-gas penetrated to the peripheral lung field. This result suggests that 99mTc-gas can be used to evaluate ventilatory function even in patients with chronic obstructive pulmonary diseases.

Topics: Gases; Humans; Krypton Radioisotopes; Lung; Lung Diseases; Particle Size; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Xenon Radioisotopes

Krypton-81m gas, by virtue of its imaging characteristics, is often considered the "gold standard" for ventilation scintigraphy but its use is restricted by its high cost and limited availability. The new radiopharmaceutical 99Tcm-Technegas, a suspension of ultrafine technetium-99m labelled carbon particles, produces high-quality images of ventilation and has the advantage of continuous availability. As part of our evaluation of Technegas the two were compared in 40 patients with a variety of established respiratory diseases. Disparities were seen in five patients in five diagnostic groups and may be a consequence of the differing physical properties of the two agents and the different inhalation techniques used. In addition two interesting features were noted on the Technegas images. (1) Hot spots were seen in 50% of patients, particularly in those with a degree of airways obstruction; (2) preferential basal deposition of activity was seen in 30%, particularly in patients with idiopathic pulmonary fibrosis. Both features were significantly associated with parameters of pulmonary function indicating obstructive lung disease in the former case and restrictive lung disease in the latter.

Topics: Adult; Aged; Female; Forced Expiratory Volume; Functional Residual Capacity; Humans; Krypton Radioisotopes; Lung; Lung Diseases; Male; Middle Aged; Radionuclide Imaging; Respiration; Sodium Pertechnetate Tc 99m; Total Lung Capacity; Vital Capacity

Topics: Australia; Evaluation Studies as Topic; Humans; Lung Diseases; Lung Diseases, Obstructive; Pulmonary Embolism; Radionuclide Imaging; Respiratory Function Tests; Sodium Pertechnetate Tc 99m; Surveys and Questionnaires

The benefits of inhaled therapy in ventilated neonates are recognized, but the reliability of drug delivery in nebulizer-ventilator circuits is uncertain. We quantified the effect of changing variables. Twenty-three freshly killed rabbits (1.15-1.9 kg) were ventilated via a tracheostomy by a pressure-limited, time-cycled ventilator (Neovent). A radioaerosol of 99Tcm pertechnetate from an Ultravent nebulizer (Mallinkrodt) was fed into the proximal ventilator tubing. Two 3-minute nebulizations at "standard settings" were followed by 2 at altered pressure, frequency, gas flow, I:E ratio, or position of the nebulizer in the circuit. Each nebulization was followed by a 3-minute gamma camera image and total deposited radioactivity was measured in excised lungs and trachea. Images demonstrated good peripheral aerosol deposition. At standard settings, lung deposition averaged 2.8% of the aerosol released. This was decreased markedly by reducing tidal volume (ventilator pressures) and residence time of aerosol (I:E ratio). Reduced gas flow decreased deposition slightly, presumably by increased particle size and marginally reduced tidal volume. Deposition did not change with increased frequency; increased minute ventilation was offset by decreased residence time of the aerosol. We conclude that the Ultravent nebulizer can be used to nebulize drugs in a standard neonatal circuit, although the dose delivered is small. Tidal volume and aerosol residence time are important determinants of aerosol delivery.

Topics: Animals; Bronchopulmonary Dysplasia; Disease Models, Animal; Humans; Infant, Newborn; Lung; Lung Compliance; Lung Diseases; Nebulizers and Vaporizers; Plethysmography; Rabbits; Radionuclide Imaging; Respiration, Artificial; Sodium Pertechnetate Tc 99m; Tidal Volume

Topics: Acquired Immunodeficiency Syndrome; Aerosols; Graphite; Humans; Lung; Lung Diseases; Opportunistic Infections; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Structure-Activity Relationship; Ventilation-Perfusion Ratio

Technegas, an aerosol generator recently devised in Australia, produces aerosol particulates called 'technegas' which have characteristics of both an aerosol and a gas. The majority of the particulate is below 200 nm in size as measured by electron microscopy. Four normal subjects and 31 patients with various lung diseases were studied by imaging the lungs following inhalation of technegas. The penetration of inhaled technegas to the lung periphery was excellent; the average alveolar deposition ratio (ALDR) was 85%. Comparative studies with lung images obtained either with an ultrasonic nebulizer or jet nebulizers also confirmed better penetration of inhaled technegas to the lung periphery. There was no significant statistical difference in the ALDRs between normals and patients. Aerosol studies were comparable to perfusion counterparts, and evaluation of regional ventilatory status was greatly facilitated. Because of the large ALDR and the low airway deposition ratio (ADR), actual imaging could be done not only immediately after aerosol inhalation but also some time later without losing too much radioactivity from the lungs. One disadvantage was that technegas immediately after generation was anoxic.

Topics: Administration, Inhalation; Adult; Female; Humans; Lung Diseases; Lung Neoplasms; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Technegas generator using 99mTc-pertechnetate was tested on 4 normal subjects and 31 patients with various chest diseases including bronchogenic carcinoma, pneumonia, pulmonary tuberculosis, sarcoidosis, and so on. Technegas was inhaled from the RV to the TLC levels through the mouth with the nose clipped followed by breath-holding. Three deep breaths were enough to deposit 37-55.5 MBq (1 to 1.5 mCi) of technegas in the lungs. The average alveolar deposition ratio (ALDR) was 85% and penetration of inhaled technegas to the lung periphery was excellent. "Hot spots" or excessive radioactive deposition were also seen when there was airway obstruction. The former indicated the characteristic as gas and the latter, that as aerosol particles. Because of the large ALDR's the timing for imaging lungs after inhalation of technegas most likely indicated the intrapulmonary sites of effective ventilation, because respective inhalation and perfusion lung images resembled each other very much. The disadvantage of technegas was that it was anoxic right after generation.

Topics: Administration, Inhalation; Adult; Aerosols; Aged; Aged, 80 and over; Female; Humans; Lung; Lung Diseases; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

The aim of this study is to evaluate the safety and clinical usefulness of lung scintigraphy using 99mTc-technegas produced by the evaporation of pertechnetate elution at 2500 degrees C. Lung images were recorded by the gamma camera-computer system after a few deep inspirations of 99mTc-technegas. One healthy volunteer and 32 patients including 10 with lung cancer, 8 with chronic obstructive lung disease, 5 with pulmonary embolism, 2 with interstitial pneumonia, 2 with bronchiectasis and 12 with other various disease were studied. Delayed images were taken at more than 1 hour later in one healthy and 13 patients to investigate the interval changes of the intrapulmonary distribution of 99mTc-technegas. Obvious differences of radioactive distribution between early and delayed image were observed in only 2/14 cases. Penetration index (P.I.) averaged 0.81 +/- 0.11 for early images and 0.85 +/- 0.12 for delayed image. There was no significant difference between P.I. for early and delayed images. More than 97 MBq of 99mTc-macroaggregated albumin (99mTc-MAA) were required to obtain the adequate perfusion images after the acquisition of lung images with about 37 MBq of 99mTc-technegas. Bronchial deposits of 99mTc-technegas were shown in 12/33 cases and pathological defects in 26/32 patients (81.3%). Twenty three of 33 cases also had a perfusion scintigraphy with 99mTc-MAA. Ventilation perfusion mismatches were presented in 5/5 patients with pulmonary embolism and 1/10 patients with lung cancer. The safety was confirmed in all cases and clinical usefulness in 30/32 patients (94%). In conclusion, the safety and clinical usefulness of lung scintigraphy with 99mTc-technegas were proven in this study.

Topics: Adolescent; Adult; Aged; Child; Female; Humans; Lung Diseases; Lung Neoplasms; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Biological characteristics and clinical utilization of 99mTc-technegas were evaluated in three normal volunteers and 10 patients with various pulmonary diseases. 99mTc-pertechnetate (296 MBq (8 mCi] was injected in the crusible of 99mTc-technegas generator, and about 37 MBq (1 mCi) of 99mTc-technegas was inhaled in the lung by three times of deep inspiration. Blood activity was appeared immediately after inhalation of 99mTc-technegas and it was 0.2% of the inhaled dose/liter of blood after 2 hours. Urine activity was also increased after inhalation and cumulative dose was 4.96% of the inhaled dose after 24 hours. The tracer dose to distribution to the lung was about 95% of the total dose in whole body. Biological half time of 99mTc-technegas in the lung was 135 hours and pulmonary image was stable even after 24 hours. Radiation dose to the lung was 0.004 Gy/37 MBq (1 mCi). In patients with pulmonary disease, distribution of 99mTc-technegas was similar to that of 81mKr gas, although defect on 99mTc-technegas image was larger in severe obstructive disease. 99mTc-technegas study was superior over 133Xe gas study to identify the areas of ventilation abnormality more clearly, although quantitative evaluation was difficult in 99mTc-technegas study. On comparative study with 99mTc-aerosol, 99mTc-technegas distributed in more peripheral sites and both methods were cooperative for evaluation of ventilatory disturbance. These results suggest that 99mTc-technegas inhalation study is safe and useful method for ventilation study.

Topics: Administration, Inhalation; Adult; Aged; Half-Life; Humans; Lung; Lung Diseases; Male; Middle Aged; Radionuclide Imaging; Respiratory Function Tests; Sodium Pertechnetate Tc 99m

Evaporation of 99mTc-pertechnetate at about 2500 degrees C on a carbon surface generates an ultrafine aerosol of labelled carbon clusters. Its particle size of about 2-5 nm enables the aerosol to behave similarly to a gas regarding the ability of penetration. After inhalation, the radioactive particles adhere to the walls of the respiratory bronchioli and alveoli. The high concentration of the radioactivity in the argon carrier gas makes it possible to record a scintigram after a single deep breath. We studied four healthy volunteers and 79 patients including 34 with a tentative diagnosis of pulmonary embolism, 20 with bronchus carcinoma, and 15 with various other lung diseases. Ten of these patients were infants, the youngest being nine months old. All patients also had a perfusion scintigraphy.

Topics: Administration, Inhalation; Adult; Aerosols; Aged; Bronchitis; Carcinoma, Bronchogenic; Female; Humans; Infant; Lung Diseases; Lung Neoplasms; Male; Middle Aged; Pulmonary Embolism; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Topics: Humans; Lung; Lung Diseases; Methods; Models, Structural; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium

Right ventricular ejection fraction (RVEF) was determine in 26 patients using the first pass radionuclide angiocardiography with 133Xe and 99Tcm as tracers. A good correlation (r = 0.88) was found. Duplicate determinations in 13 patients with 133Xe showed good reproducibility, the absolute value for the standard error of a single determination being 2.6% and the coefficient of variation 5.7%. In a reference group of 17 individuals RVEF was 49 +/- 5% (range 42-61%). It is concluded that 133Xe can be used for RVEF determinations. Due to the rapid elimination and the low radiation dose 133Xe is preferable when repeated determinations of RVEF are desired.

Topics: Adult; Cardiac Output; Heart; Heart Diseases; Heart Ventricles; Humans; Lung Diseases; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium; Xenon Radioisotopes