sodium-pertechnetate-tc-99m and Asthma

99mTc-Technegas (Technegas) scintigraphy, including planar and SPECT images, was reviewed in patients who mainly had pulmonary emphysema. The Technegas images showed different degrees of change, from areas of heterogeneity to hot spots or defects. Comparison of planar and SPECT Technegas images revealed that more detailed findings were shown by SPECT than by planar images in mild cases. In more severe cases, the findings of SPECT and planar images were equivalent. In advanced stages, SPECT images should be excluded in favor of planar images. Technegas SPECT could demonstrate ventilation impairment more easily than 133Xe gas dynamic SPECT. The optical average score of Technegas in whole lung correlated well with forced expiratory volume in one second (FEV1.0) and FEV1.0/forced vital capacity. Technegas could assess ventilation impairment in pulmonary emphysema more easily than CT, especially in the upper lung field. Technegas was useful for the assessment not only of pulmonary emphysema but also of other diseases. For the quantitative evaluation of Technegas, some investigators study three-dimensional fractal analysis or mean voxel values of the lung. These quantitative analyses are useful for classifying clinical stage and comparing cases.

Topics: Asthma; Female; Humans; Lung Diseases, Interstitial; Male; Pulmonary Emphysema; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed, Single-Photon

Topics: Asthma; Bronchitis; Humans; Krypton; Lung; Pulmonary Ventilation; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Xenon Radioisotopes

In this study, the influence of lung function on lung deposition of a radioactively labeled Formotoerol HFA MDI (Forair) was investigated. Eighteen subjects were measured: 6 healthy subjects (FEV(1) = 107% pred), 6 patients with Asthma (FEV(1) = 72% pred), and 6 patients with COPD (FEV(1) = 40% pred). The lung deposition of the radioactive-labeled drug was measured with a gamma camera. The lung deposition relative to the emitted dose was 31% for healthy subjects, 34% for asthmatics, and 35% for COPD patients. These data suggest a comparable lung deposition in the different populations. There was no significant correlation between lung function (FEV(1)) and lung deposition. The extrathoracic deposition was around 50%. The finding were that lung deposition of the inhaled Formoterol did not depend on lung function and the relative high values of lung deposition can be explained by the small particle size (0.8 microm) of the HFA-Formoterol-Formulation and the slow inhalation (30 L/min flow) used in this study. It can be concluded, that with this modern HFA drug formulation, the deposition is high, even in obstructed lungs.

Topics: Administration, Inhalation; Adult; Aerosols; Aged; Asthma; Bronchodilator Agents; Ethanolamines; Female; Forced Expiratory Volume; Formoterol Fumarate; Humans; Lung; Male; Metered Dose Inhalers; Middle Aged; Particle Size; Pulmonary Disease, Chronic Obstructive; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m

Regional expiratory flow limitation (EFL) may occur during tidal breathing without being detected by measurements of flow at the mouth. We tested this hypothesis by using Technegas to reveal sites of EFL. A first study (study 1) was undertaken to determine whether deposition of Technegas during tidal breathing reveals the occurrence of regional EFL in induced bronchoconstriction. Time-activity curves of Technegas inhaled during 12 tidal breaths were measured in four asthmatic subjects at control conditions and after exposure to inhaled methacholine at a dose sufficient to abolish expiratory flow reserve near functional residual capacity. A second study (study 2) was conducted in seven asthmatic subjects at control and after three increasing doses of methacholine to compare the pattern of Technegas deposition in the lung with the occurrence of EFL. The latter was assessed at the mouth by comparing tidal with forced expiratory flow or with the flow generated on application of a negative pressure. Study 1 documented enhanced and spotty deposition of Technegas in the central lung regions with increasing radioactivity during tidal expiration. This is consistent with increased impaction of Technegas on the airway wall downstream from the flow-limiting segment. Study 2 showed that both methods based on analysis of flow at the mouth failed to detect EFL at the time spotty deposition of Technegas occurred. We conclude that regional EFL occurs asynchronously across the lung and that methods based on mouth flow measurements are insensitive to it.

Topics: Adult; Asthma; Bronchi; Bronchoconstriction; Bronchoconstrictor Agents; Diagnostic Imaging; Humans; Lung Volume Measurements; Male; Methacholine Chloride; Middle Aged; Peak Expiratory Flow Rate; Respiratory Function Tests; Respiratory Mechanics; Sodium Pertechnetate Tc 99m; Spirometry; Tomography, Emission-Computed, Single-Photon

Pulmonary distribution and lung functions were evaluated during a 4-month inhaled corticosteroid treatment period in 10 steroid-naïve novel asthmatics with normal or slightly reduced lung functions. Patients were given a total daily dose of 1000 microg of beclomethasone dipropionate aerosol twice a day via a pressured metered dose inhaler with a large-volume chamber device (Volumatic, GlaxoSmith Kline, U.K.). Gamma lung scintigraphy and lung function tests were performed before and after 2 months and 4 months. Inhaled 99mTc-labelled beclomethasone dipropionate liposomes were used to assess lung deposition patterns during inhaled steroid therapy. Serum eosinophil cationic protein (ECP) concentration was used as a surrogate marker of asthmatic inflammation. Following beclomethasone treatment, all lung functions were enhanced, but only FVC values showed significant improvement. The FEV1/FVC ratio remained slightly reduced in spite of inhaled corticosteroid therapy. However, the association between changes in improved FVC values and reduced ECP levels proved to be statistically significant. In lung scintigraphy, no evidence of changes in pulmonary deposition patterns were seen during the follow-up period. We conclude that inhaled corticosteroid therapy can lead to improvements in lung functions and surrogate markers of airway inflammation in novel asthma without affecting the peripheral deposition pattern of aerosols.

Topics: Administration, Inhalation; Adult; Asthma; Beclomethasone; Blood Proteins; Eosinophil Granule Proteins; Forced Expiratory Volume; Glucocorticoids; Humans; Lung; Metered Dose Inhalers; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Ribonucleases; Sodium Pertechnetate Tc 99m; Vital Capacity

A distinctive feature of cerebral blood circulation in patients with chronic non-specific lung diseases (CNLD) complicated with chronic pulmonary heart (CPH) is a pronounced disturbance of cerebral venous drainage without a reliable reduction of both cerebral circulation and blood flow in common carotid arteries. Correlation between the degree of venous drainage disturbance and an extent of CNLD was found. Atherosclerotic damage of major arteries of the head in patients with ischemic stroke (IS) and CNLD was less marked. A comparative comprehensive study of the state of cerebral circulation was performed in two groups of patients. Predominance of the disturbance of venous outflow was found in the patients with IS and CNLD. The volumetric blood flow reduction prevailed in a group of patients with IS due to carotid occlusion. There was no significant difference in local cerebral circulation between the two groups. Obviously the disturbance of venous outflow causes the decrease of cerebral blood circulation in patients with CNLD, therefore "venous stroke" is possible in some patients with CNLD. Poor prognosis of IS in patients with CNLD and CPH is registered. It is stated that venous drainage disturbance and volumetric blood flow reduction in common carotids are main factors affecting progress and outcome of IS.

Topics: Aged; Asthma; Brain; Carotid Artery, Common; Cerebrovascular Circulation; Cerebrovascular Disorders; Female; Hemodynamics; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Pulmonary Heart Disease; Radionuclide Imaging; Radiopharmaceuticals; Respiratory Function Tests; Sodium Pertechnetate Tc 99m

Bronchial asthma is a clinical syndrome characterized by the reversibility of airway obstruction. Recently it has been suggested that remodeling of the airway causes irreversible airway obstruction which may be responsible for the patient's symptoms. With this background, the purpose of the present study was to assess patients with corticosteroid-dependent asthma by Tc-99m Technegas scintigraphy (Technegas) in both planar and SPECT images. Twelve patients (7 females and 5 males aged 36-72 years with a median age of 60 years: 4 smokers and 8 non-smokers) with oral corticosteroid-dependent asthma were enrolled in this study. Lung ventilation scanning with Technegas in both planar and SPECT images, high-resolution computed tomography, and pulmonary function tests were performed in all patients. The results of Technegas scanning were graded and correlations with other clinical parameters were evaluated. Significant abnormalities were detected by ventilation scintigraphy with Technegas in patients with corticosteroid-dependent bronchial asthma even during remission. Our data demonstrate that airflow obstruction took place in patients with corticosteroid-dependent asthma even during remission. Technegas scanning appears to be a useful radiopharmaceutical for demonstrating airflow obstruction in patients with bronchial asthma.

Topics: Adrenal Cortex Hormones; Adult; Aged; Asthma; Bronchi; Female; Humans; Lung; Male; Middle Aged; Radiopharmaceuticals; Smoking; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed, Single-Photon; Ventilation-Perfusion Ratio

The absence of a maximal dose-response plateau as well as gas trapping and increases in closing capacity (CC) suggest that increased airway closure is an important mechanical abnormality of asthmatic airways. We compared the extent and distribution of airway closure in 13 normal and in 23 asthmatic subjects. Airway closure (LVclosed) was measured with single-photon emission computed tomography (SPECT) and an inhaled Technegas bolus as the percentage of lung volume without Technegas (LVtrans), and with CC, using nitrogen washout. LVclosed was compared in the apical, middle and lower zones, each being of equal vertical height. Values of mean LVclosed +/- 95% confidence interval (CI) were similar in normal (30 +/- 6.0% LVtrans) and asthmatic subjects (30 +/- 7.8% LVtrans). In normal subjects, LVclosed correlated with both age (r = 0.89, p < 0. 01) and CC (r = 0.86, p < 0.01), was more extensive in the lower zone (58 +/- 18.8% LVtrans, p < 0.01) than in the middle and upper zones (17 +/- 8.7% and 26 +/- 8.2 LVtrans, respectively), and increased with age in both the middle and lower zones (r = 0.94 and r = 0.90, respectively, p < 0.01). In asthmatic subjects, LVclosed did not correlate with age; was greatest in the lower zone, intermediate in the middle zone, and lowest in the apical zone (59 +/- 13.2%, 22 +/- 5.8%, and 12 +/- 4.4% LVtrans, respectively, p < 0. 01); and correlated weakly with age in the middle zone only (r = 0. 46, p < 0.05). We conclude that there is a predictable pattern of airway closure in normal subjects and that it is primarily influenced by pulmonary elastic recoil. This pattern is lost in asthmatic subjects. This may be explained by an increased range of closing pressures and a patchy distribution of airway closure, probably secondary to allergic inflammation.

Topics: Administration, Inhalation; Adult; Age Factors; Analysis of Variance; Asthma; Closing Volume; Confidence Intervals; Elasticity; Female; Forecasting; Graphite; Humans; Lung; Lung Compliance; Lung Volume Measurements; Male; Nitrogen; Pressure; Radiopharmaceuticals; Respiratory Hypersensitivity; Respiratory Mechanics; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed, Single-Photon

The scintigraphic detection of small nocturnal aspirations of radio-labelled gastric contents is difficult in the presence of high remaining activity in the abdomen, causing a non-uniform background activity. This problem was examined in phantom experiments and a technique for interpolative background correction was further developed. The accuracy of this technique was found to be influenced by the distance between the lung and the abdominal source of activity, and the minimum detectable 'aspirated' activity was determined as 0.1 MBq at a distance of 15 cm and 1 MBq at 5 cm. The interpolative technique for background correction was evaluated on healthy volunteers and laryngectomized patients, examined 10 h after intragastric instillation of 200 MBq of 99Tcm-pertechnetate. After background subtraction, their calculated pulmonary mean net count value was comparable to that registered before the radioactive tracer was administered. No localized accumulation of activity was found in any of these controls. The technique was then applied clinically to 55 patients with chronic respiratory disorders and symptoms of gastroesophageal reflux. Aspiration was detected in 11 patients (20%). Five aspirators had asthma, two a chronic cough of unknown origin, two recurrent pulmonary infections, and one chronic bronchitis and chronic laryngitis respectively. Aspiration was detected among patients with and without demonstrated pathological gastroesophageal reflux.

Topics: Adult; Aged; Asthma; Chronic Disease; Female; Gastroesophageal Reflux; Humans; Hydrogen-Ion Concentration; Intubation, Gastrointestinal; Laryngectomy; Lung; Male; Middle Aged; Pneumonia, Aspiration; Radionuclide Imaging; Respiratory Tract Diseases; Sodium Pertechnetate Tc 99m

Topics: Adult; Aged; Asthma; Esophageal Diseases; Esophagus; Female; Humans; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium