Imaging of ventilation/perfusion ratio by gated regional spirometry

International Nuclear Information System (INIS)

Touya, J.J.; Jones, J.P.; Price, R.R.; Patton, J.A.; Erickson, J.J.; Rollo, F.D.

1981-01-01

Gated 133 Xe images of patients rebreathing into a closed system can provide images of the distribution of lung volumes, ventilation and specific ventilation. These have been shown to be accurate, precise, and do not require unusually sophisticated equipment or skills. A mathematical transformation is used to correct the images for lung movement, which does not alter the total number of counts in the image. Perfusion images are gated to remove motion blurring but not transformed. Ventilation/perfusion images showing the distribution of V/Q ratio are then generated from the individual ventilation and perfusion images. (author)

Methodology for ventilation/perfusion SPECT

DEFF Research Database (Denmark)

Bajc, Marika; Neilly, Brian; Miniati, Massimo

2010-01-01

Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas ov...

Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

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Dowdle, S.C.; Human, D.G.; Mann, M.D. (Univ. of Cape Town (South Africa))

1990-08-01

Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis.

Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

International Nuclear Information System (INIS)

Dowdle, S.C.; Human, D.G.; Mann, M.D.

1990-01-01

Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis

Ventilation and Perfusion Lung Scintigraphy of Allergen-Induced Airway Responses in Atopic Asthmatic Subjects

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Krishnan Parameswaran

2007-01-01

Full Text Available BACKGROUND: Both ventilation (V and perfusion (Q of the lungs are altered in asthma, but their relationships with allergen-induced airway responses and gas exchange are not well described.

Effect of endobronchial valve therapy on pulmonary perfusion and ventilation distribution.

Directory of Open Access Journals (Sweden)

Carmen Pizarro

Full Text Available Endoscopic lung volume reduction (ELVR is an emerging therapy for emphysematous COPD. However, any resulting changes in lung perfusion and ventilation remain undetermined. Here, we report ELVR-mediated adaptations in lung perfusion and ventilation, as investigated by means of pulmonary scintigraphy.In this observational study, we enrolled 26 patients (64.9 ± 9.4 yrs, 57.7% male with COPD heterogeneous emphysema undergoing ELVR with endobronchial valves (Zephyr, Pulmonx, Inc.. Mean baseline FEV1 and RV were 32.9% and 253.8% predicted, respectively. Lung scintigraphy was conducted prior to ELVR and eight weeks thereafter. Analyses of perfusion and ventilation shifts were performed and complemented by correlation analyses between paired zones.After ELVR, target zone perfusion showed a mean relative reduction of 43.32% (p<0.001, which was associated with a significant decrease in target zone ventilation (p<0.001. Perfusion of the contralateral untreated zone and of the contralateral total lung exhibited significant increases post-ELVR (p = 0.002 and p = 0.005, respectively; both correlated significantly with the corresponding target zone perfusion adaptations. Likewise, changes in target zone ventilation correlated significantly with ventilatory changes in the contralateral untreated zone and the total contralateral lung (Pearson's r: -0.42, p = 0.04 and Pearson's r: -0.42, p = 0.03, respectively. These effects were observed in case of clinical responsiveness to ELVR, as assessed by changes in the six-minute walk test distance.ELVR induces a relevant decrease in perfusion and ventilation of the treated zone with compensatory perfusional and ventilatory redistribution to the contralateral lung, primarily to the non-concordant, contralateral zone.

Pulmonary ventilation and perfusion imaging with dual-energy CT

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Thieme, Sven F. [Klinikum Grosshadern, Department of Clinical Radiology, Ludwig Maximilians University, Muenchen (Germany); Klinikum Grosshadern, Institut fuer Klinische Radiologie, LMU Muenchen, Muenchen (Germany); Hoegl, Sandra; Fisahn, Juergen; Irlbeck, Michael [Klinikum Grosshadern, Department of Anesthesiology, Ludwig Maximilians University, Muenchen (Germany); Nikolaou, Konstantin; Maxien, Daniel; Reiser, Maximilian F.; Becker, Christoph R.; Johnson, Thorsten R.C. [Klinikum Grosshadern, Department of Clinical Radiology, Ludwig Maximilians University, Muenchen (Germany)

2010-12-15

To evaluate the feasibility of dual-energy CT (DECT) ventilation imaging in combination with DE perfusion mapping for a comprehensive assessment of ventilation, perfusion, morphology and structure of the pulmonary parenchyma. Two dual-energy CT acquisitions for xenon-enhanced ventilation and iodine-enhanced perfusion mapping were performed in patients under artificial respiration. Parenchymal xenon and iodine distribution were mapped and correlated with structural or vascular abnormalities. In all datasets, image quality was sufficient for a comprehensive image reading of the pulmonary CTA images, lung window images and pulmonary functional parameter maps and led to expedient results in each patient. With dual-source CT systems, DECT of the lung with iodine or xenon administration is technically feasible and makes it possible to depict the regional iodine or xenon distribution representing the local perfusion and ventilation. (orig.)

Study of regional lung ventilation and perfusion by xenon 133

International Nuclear Information System (INIS)

Lombard, Yves.

1976-01-01

The present work consists of a regional lung exploration after injection of xenon 133, dissolved in physiological serum, followed a few minutes later by that of 99m Tc-labelled serumalbumin microspheres. The aim is three fold: first of all to study perfusion and ventilation by xenon 133, next to compare the results obtained after xenon 133 and 99 m Tc-labelled microsphere injection, lastly to establish the value of the technique and its routine application. This examination has not solved all problems of lung exploration by xenon 133. For example we deliberately kept to intraveinous injection of the gas dissolved in physiological serum, leaving aside the breathing test. Xenon 133 scintigraphy in our opinion will not tend to replace 99m Tc-labelled microsphere scintigraphy, which has irreplaceable morphological qualities, but will serve as an excellent complement. The basic advantage of xenon 133 is the regional ventilation estimate it provides allowing any anomaly of the lung parenchyma to be located immediately or conversely the functional value of the healthy lung to be established with a view to a surgical removal of a diseased zone [fr

The uptake and metabolism of cystamine and taurine by isolated, ventilated and perfused rat and rabbit lungs

International Nuclear Information System (INIS)

Sharma, R.; Kodavanti, U.P.; Smith, L.L.; Mehendale, H.M.

1991-01-01

Cystamine has been reported to be taken up by the lung slices and metabolized to taurine via hypotaurine through enzymatic processes. The objective of these studies was to determine whether intact isolated, ventilated and perfused rat and rabbit lungs also posses similar characteristics. The lungs were isolated from male New Zealand white rabbits and S-D rats and perfused with 20 μM [ 14 C] cystamine (Sp. Act., 16.4 mCi/mmol) for 60 min and 30 min, respectively. Cystamine and its metabolites in lung as well as in perfusate were separated by TLC and quantitated using scintillation spectrometry. Similar experiments were also conducted with 20 μM taurine to investigate its fate in perfused lungs. Significant pulmonary uptake of cystamine and taurine occurred during perfusion. Cystamine was metabolized to [ 14 C] hypotaurine and [ 14 C] taurine. No further metabolism of taurine was evident in rat or rabbit lungs. Inclusion of 1 nM GSH did not significantly alter the ability of lungs to sequester cystamine, but the metabolism of hypotaurine to taurine was decreased. It was evident that cystamine was metabolized to taurine by perfused lungs in the same way as in lung slices

Lung scintigraphy in differential diagnosis of peripheral lung cancer and community-acquired pneumonia

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Krivonogov, Nikolay G., E-mail: kng@cardio-tomsk.ru [Research Institute of Cardiology, Kievskaya Street 111a, Tomsk, 634012 (Russian Federation); Efimova, Nataliya Y., E-mail: efimova@cardio-tomsk.ru; Zavadovsky, Konstantin W.; Lishmanov, Yuri B. [Research Institute of Cardiology, Kievskaya Street 111a, Tomsk, 634012 (Russian Federation); Tomsk Polytechnic University, Lenin Avenue 30, Tomsk, 634050 (Russian Federation)

2016-08-02

Ventilation/perfusion lung scintigraphy was performed in 39 patients with verified diagnosis of community-acquired pneumonia (CAP) and in 14 patients with peripheral lung cancer. Ventilation/perfusion ratio, apical-basal gradients of ventilation (U/L(V)) and lung perfusion (U/L(P)), and alveolar capillary permeability of radionuclide aerosol were determined based on scintigraphy data. The study demonstrated that main signs of CAP were increases in ventilation/perfusion ratio, perfusion and ventilation gradient on a side of the diseased lung, and two-side increase in alveolar capillary permeability rate for radionuclide aerosol. Unlike this, scintigraphic signs of peripheral lung cancer comprise an increase in ventilation/perfusion ratio over 1.0 on a side of the diseased lung with its simultaneous decrease on a contralateral side, normal values of perfusion and ventilation gradients of both lungs, and delayed alveolar capillary clearance in the diseased lung compared with the intact lung.

Lung scintigraphy in differential diagnosis of peripheral lung cancer and community-acquired pneumonia

Science.gov (United States)

Krivonogov, Nikolay G.; Efimova, Nataliya Y.; Zavadovsky, Konstantin W.; Lishmanov, Yuri B.

2016-08-01

Ventilation/perfusion lung scintigraphy was performed in 39 patients with verified diagnosis of community-acquired pneumonia (CAP) and in 14 patients with peripheral lung cancer. Ventilation/perfusion ratio, apical-basal gradients of ventilation (U/L(V)) and lung perfusion (U/L(P)), and alveolar capillary permeability of radionuclide aerosol were determined based on scintigraphy data. The study demonstrated that main signs of CAP were increases in ventilation/perfusion ratio, perfusion and ventilation gradient on a side of the diseased lung, and two-side increase in alveolar capillary permeability rate for radionuclide aerosol. Unlike this, scintigraphic signs of peripheral lung cancer comprise an increase in ventilation/perfusion ratio over 1.0 on a side of the diseased lung with its simultaneous decrease on a contralateral side, normal values of perfusion and ventilation gradients of both lungs, and delayed alveolar capillary clearance in the diseased lung compared with the intact lung.

Assessment of regional lung functional impairment with co-registered respiratory-gated ventilation/perfusion SPET-CT images: initial experiences

International Nuclear Information System (INIS)

Suga, Kazuyoshi; Yasuhiko, Kawakami; Zaki, Mohammed; Yamashita, Tomio; Seto, Aska; Matsumoto, Tsuneo; Matsunaga, Naofumi

2004-01-01

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 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. (orig.)

Reproducibility of Lobar Perfusion and Ventilation Quantification Using SPECT/CT Segmentation Software in Lung Cancer Patients.

Science.gov (United States)

Provost, Karine; Leblond, Antoine; Gauthier-Lemire, Annie; Filion, Édith; Bahig, Houda; Lord, Martin

2017-09-01

Planar perfusion scintigraphy with 99m Tc-labeled macroaggregated albumin is often used for pretherapy quantification of regional lung perfusion in lung cancer patients, particularly those with poor respiratory function. However, subdividing lung parenchyma into rectangular regions of interest, as done on planar images, is a poor reflection of true lobar anatomy. New tridimensional methods using SPECT and SPECT/CT have been introduced, including semiautomatic lung segmentation software. The present study evaluated inter- and intraobserver agreement on quantification using SPECT/CT software and compared the results for regional lung contribution obtained with SPECT/CT and planar scintigraphy. Methods: Thirty lung cancer patients underwent ventilation-perfusion scintigraphy with 99m Tc-macroaggregated albumin and 99m Tc-Technegas. The regional lung contribution to perfusion and ventilation was measured on both planar scintigraphy and SPECT/CT using semiautomatic lung segmentation software by 2 observers. Interobserver and intraobserver agreement for the SPECT/CT software was assessed using the intraclass correlation coefficient, Bland-Altman plots, and absolute differences in measurements. Measurements from planar and tridimensional methods were compared using the paired-sample t test and mean absolute differences. Results: Intraclass correlation coefficients were in the excellent range (above 0.9) for both interobserver and intraobserver agreement using the SPECT/CT software. Bland-Altman analyses showed very narrow limits of agreement. Absolute differences were below 2.0% in 96% of both interobserver and intraobserver measurements. There was a statistically significant difference between planar and SPECT/CT methods ( P software is highly reproducible. This tridimensional method yields statistically significant differences in measurements for right lung lobes when compared with planar scintigraphy. We recommend that SPECT/CT-based quantification be used for all lung

Non-contrast-enhanced perfusion and ventilation assessment of the human lung by means of fourier decomposition in proton MRI.

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Bauman, Grzegorz; Puderbach, Michael; Deimling, Michael; Jellus, Vladimir; Chefd'hotel, Christophe; Dinkel, Julien; Hintze, Christian; Kauczor, Hans-Ulrich; Schad, Lothar R

2009-09-01

Assessment of regional lung perfusion and ventilation has significant clinical value for the diagnosis and follow-up of pulmonary diseases. In this work a new method of non-contrast-enhanced functional lung MRI (not dependent on intravenous or inhalative contrast agents) is proposed. A two-dimensional (2D) true fast imaging with steady precession (TrueFISP) pulse sequence (TR/TE = 1.9 ms/0.8 ms, acquisition time [TA] = 112 ms/image) was implemented on a 1.5T whole-body MR scanner. The imaging protocol comprised sets of 198 lung images acquired with an imaging rate of 3.33 images/s in coronal and sagittal view. No electrocardiogram (ECG) or respiratory triggering was used. A nonrigid image registration algorithm was applied to compensate for respiratory motion. Rapid data acquisition allowed observing intensity changes in corresponding lung areas with respect to the cardiac and respiratory frequencies. After a Fourier analysis along the time domain, two spectral lines corresponding to both frequencies were used to calculate the perfusion- and ventilation-weighted images. The described method was applied in preliminary studies on volunteers and patients showing clinical relevance to obtain non-contrast-enhanced perfusion and ventilation data.

Topographic distribution of pulmonary ventilation and perfusion in the horse

International Nuclear Information System (INIS)

Amis, T.C.; Pascoe, J.R.; Hornof, W.

1984-01-01

The regional distribution of ventilation to perfusion ratios (VA/Q) in the lungs of 8 healthy standing Thoroughbred geldings (4.4 +/- 1.5 years, 465.7 +/- 46.6 kg) was studied, using steady-state inhalation and IV infusion of the radioactive gas krypton-81m. The VA/Q was uniformly distributed within a vertical lung strip centered over the 9th rib on the right side. Ventilation per unit of alveolar volume (V/VA) assessed from the clearance of inhaled radioactive gas in 5 horses increased from 0.49 +/- 0.13 (arbitrary units) in nondependent lung zones to 1.45 +/- 0.16 in dependent lung zones. Seemingly, a vertical gradient of pulmonary ventilation exists in the horse that is matched by a similar gradient of perfusion

Topographic distribution of pulmonary ventilation and perfusion in the horse

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Amis, T.C.; Pascoe, J.R.; Hornof, W.

1984-08-01

The regional distribution of ventilation to perfusion ratios (VA/Q) in the lungs of 8 healthy standing Thoroughbred geldings (4.4 +/- 1.5 years, 465.7 +/- 46.6 kg) was studied, using steady-state inhalation and IV infusion of the radioactive gas krypton-81m. The VA/Q was uniformly distributed within a vertical lung strip centered over the 9th rib on the right side. Ventilation per unit of alveolar volume (V/VA) assessed from the clearance of inhaled radioactive gas in 5 horses increased from 0.49 +/- 0.13 (arbitrary units) in nondependent lung zones to 1.45 +/- 0.16 in dependent lung zones. Seemingly, a vertical gradient of pulmonary ventilation exists in the horse that is matched by a similar gradient of perfusion.

Hypercapnic acidosis modulates inflammation, lung mechanics, and edema in the isolated perfused lung.

Science.gov (United States)

De Smet, Hilde R; Bersten, Andrew D; Barr, Heather A; Doyle, Ian R

2007-12-01

Low tidal volume (V(T)) ventilation strategies may be associated with permissive hypercapnia, which has been shown by ex vivo and in vivo studies to have protective effects. We hypothesized that hypercapnic acidosis may be synergistic with low V(T) ventilation; therefore, we studied the effects of hypercapnia and V(T) on unstimulated and lipopolysaccharide-stimulated isolated perfused lungs. Isolated perfused rat lungs were ventilated for 2 hours with low (7 mL/kg) or moderately high (20 mL/kg) V(T) and 5% or 20% CO(2), with lipopolysaccharide or saline added to the perfusate. Hypercapnia resulted in reduced pulmonary edema, lung stiffness, tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) in the lavage and perfusate. The moderately high V(T) did not cause lung injury but increased lavage IL-6 and perfusate IL-6 as well as TNF-alpha. Pulmonary edema and respiratory mechanics improved, possibly as a result of a stretch-induced increase in surfactant turnover. Lipopolysaccharide did not induce significant lung injury. We conclude that hypercapnia exerts a protective effect by modulating inflammation, lung mechanics, and edema. The moderately high V(T) used in this study stimulated inflammation but paradoxically improved edema and lung mechanics with an associated increase in surfactant release.

Evaluation of pN factors in patients with primary lung cancer by using perfusion, inhalation and ventilation studies

International Nuclear Information System (INIS)

Tamai, Toyosato; Tanabe, Masatada; Satoh, Katashi

1987-01-01

The interpretation of scintigraphic patterns and the role of pathophysiological mechanisms in patients with primary lung cancer were investigated. To determine the relative roles of perfusion, inhalation and ventilation scintigraphy, the relationship between the count ratio of the affected side to the healthy side and the post-surgical histological lymph nodes factors were observed in this study. These scintigraphic count ratio's in patients with primary lung cancer did not reflect the pN factors except in the perfusion study in patients with hilar primary lung cancer. (author)

Ventilation-perfusion scans in neonatal regional pulmonary emphysema complicating ventilatory assistance

International Nuclear Information System (INIS)

Leonidas, J.C.; Moylan, F.M.B.; Kahn, P.C.; Ramenofsky, M.L.

1978-01-01

Two cases of ventilator-related neonatal lobar overexpansion with similar radiographic appearance, but probably different pathogenesis, are presented. In one infant, persistent interstitial lobar emphysema was confirmed by markedly decreased perfusion shown on scintigraphy; this information was of great value in predicting the beneficial effect of lobectomy. In the other case, ventilation and perfusion scans indicated functional value of the emphysematous lobe and correctly suggested conservative management. Radioisotope lung scans may provide valuable information regarding lung function in regional pulmonary emphysema associated with assisted ventilation in neonatal respiratory distress syndrome, and thus determine patient management

MR-based assessment of pulmonary ventilation-perfusion in animal models

International Nuclear Information System (INIS)

Yang Jian; Wan Mingxi; Guo Youmin

2003-01-01

Objective: To show the feasibility and value in the diagnosis of airway obstruction and pulmonary embolism with MR oxygen-enhanced ventilation combined with pulmonary perfusion imaging. Methods: Eight canines were implemented for peripheral pulmonary embolism by intravenous injection of gelfoam granules at pulmonary segmental arterial level, and five of them were formed airway obstruction models by inserting self-made balloon catheter at second-bronchia. The oxygen-enhanced MR ventilation imaging was introduced by subtracting the images of pre- and post- inhaled pure oxygen. The MR pulmonary perfusion imaging was achieved by the first-pass contrast agent method. Moreover, the manifestation of MR ventilation and perfusion imaging was observed and contradistinguished with that of general pathologic anatomy, ventilation-perfusion scintigraphy, and pulmonary angiography. Results: The manifestations of airway obstruction regions in MR ventilation and perfusion imaging were matched, but those of pulmonary embolism regions were dismatched. The defect range of airway obstruction in MR ventilation image was smaller than that in ventilation scintigraphy. The abnormal perfusion regions of pulmonary embolism were divided into defect regions and reduce regions based on the time courses of signal intensity changes. The sensitivity and specificity of diagnosis on pulmonary embolism by MR ventilation combined with perfusion technique were 75.0% and 98.1%. The diagnostic results were in good coherence with ventilation-perfusion scintigraphy and pulmonary angiography (K=0.743, 0.899). Conclusion: The MR oxygen-enhanced ventilation combined with pulmonary perfusion imaging can be used to diagnose the airway and vascular abnormity in lung. This technique resembles the ventilation-perfusion scintigraphy. It can provide quantitative functional information and better spatial and temporal resolution, and possesses the value of clinical application

Automatic delineation of functional lung volumes with 68Ga-ventilation/perfusion PET/CT.

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Le Roux, Pierre-Yves; Siva, Shankar; Callahan, Jason; Claudic, Yannis; Bourhis, David; Steinfort, Daniel P; Hicks, Rodney J; Hofman, Michael S

2017-10-10

Functional volumes computed from 68 Ga-ventilation/perfusion (V/Q) PET/CT, which we have shown to correlate with pulmonary function test parameters (PFTs), have potential diagnostic utility in a variety of clinical applications, including radiotherapy planning. An automatic segmentation method would facilitate delineation of such volumes. The aim of this study was to develop an automated threshold-based approach to delineate functional volumes that best correlates with manual delineation. Thirty lung cancer patients undergoing both V/Q PET/CT and PFTs were analyzed. Images were acquired following inhalation of Galligas and, subsequently, intravenous administration of 68 Ga-macroaggreted-albumin (MAA). Using visually defined manual contours as the reference standard, various cutoff values, expressed as a percentage of the maximal pixel value, were applied. The average volume difference and Dice similarity coefficient (DSC) were calculated, measuring the similarity of the automatic segmentation and the reference standard. Pearson's correlation was also calculated to compare automated volumes with manual volumes, and automated volumes optimized to PFT indices. For ventilation volumes, mean volume difference was lowest (- 0.4%) using a 15%max threshold with Pearson's coefficient of 0.71. Applying this cutoff, median DSC was 0.93 (0.87-0.95). Nevertheless, limits of agreement in volume differences were large (- 31.0 and 30.2%) with differences ranging from - 40.4 to + 33.0%. For perfusion volumes, mean volume difference was lowest and Pearson's coefficient was highest using a 15%max threshold (3.3% and 0.81, respectively). Applying this cutoff, median DSC was 0.93 (0.88-0.93). Nevertheless, limits of agreement were again large (- 21.1 and 27.8%) with volume differences ranging from - 18.6 to + 35.5%. Using the 15%max threshold, moderate correlation was demonstrated with FEV1/FVC (r = 0.48 and r = 0.46 for ventilation and perfusion images, respectively

Idiopathic pulmonary fibrosis. A rare cause of scintigraphic ventilation-perfusion mismatch

International Nuclear Information System (INIS)

Pochis, W.T.; Krasnow, A.Z.; Collier, B.D.; Mewissen, M.W.; Almagro, U.A.; Hellman, R.S.; Isitman, A.T.

1990-01-01

A case of idiopathic pulmonary fibrosis with multiple areas of mismatch on ventilation-perfusion lung imaging in the absence of pulmonary embolism is presented. Idiopathic pulmonary fibrosis is one of the few nonembolic diseases producing a pulmonary ventilation-perfusion mismatch. In this condition, chest radiographs may not detect the full extent of disease, and xenon-133 ventilation imaging may be relatively insensitive to morbid changes in small airways. Thus, when examining patients with idiopathic pulmonary fibrosis, one should be aware that abnormal perfusion imaging patterns without matching ventilation abnormalities are not always due to embolism. In this setting, contrast pulmonary angiography is often needed for accurate differential diagnosis

Idiopathic pulmonary fibrosis. A rare cause of scintigraphic ventilation-perfusion mismatch

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Pochis, W.T.; Krasnow, A.Z.; Collier, B.D.; Mewissen, M.W.; Almagro, U.A.; Hellman, R.S.; Isitman, A.T. (Medical College of Wisconsin, Milwaukee (USA))

1990-05-01

A case of idiopathic pulmonary fibrosis with multiple areas of mismatch on ventilation-perfusion lung imaging in the absence of pulmonary embolism is presented. Idiopathic pulmonary fibrosis is one of the few nonembolic diseases producing a pulmonary ventilation-perfusion mismatch. In this condition, chest radiographs may not detect the full extent of disease, and xenon-133 ventilation imaging may be relatively insensitive to morbid changes in small airways. Thus, when examining patients with idiopathic pulmonary fibrosis, one should be aware that abnormal perfusion imaging patterns without matching ventilation abnormalities are not always due to embolism. In this setting, contrast pulmonary angiography is often needed for accurate differential diagnosis.

Diagnostic significance of lung ventilation study with sup(81m)Kr gas

International Nuclear Information System (INIS)

Narabayashi, Isamu; Ito, Yasuhiko; Ohtsuka, Nobuaki; Muranaka, Akira; Yokobayashi, Tsuneo

1979-01-01

Lung ventilation study was performed on 43 patients by the continuous inhalation of sup(81m)Kr gas from a 81 Rb-sup(81m)Kr generator (Nihon Mediphysics Inc. Hyogo Japan). The patients were measured in a sitting position using a scintillation camera in conjunction with a data processor. In 37 cases, scintigraphic findings were compared with those of sup(99m)Tc-MAA images. We discussed the ventilation/perfusion mismatching cases, especially in those of the pulmonary arterial abnormarity and lung cancer. In some of the discrepancy between ventilation and perfusion, nuclear angiography with sup(99m)Tc-HSA was performed. The following results were obtained by those studies. 1) The distribution of sup(81m)Kr gas within the lung is considered proportional to regional ventilation because of a short half life of sup(81m)Kr (13 seconds). 2) The ventilation image with sup(81m)Kr gas was clearly visualized because of the lower gamma-ray energy and much accumulation of activity. 3) Combined use of ventilation-perfusion scintigraphy and nuclear angiography often gave us new additional informations about the pathophysiological condition of lung. 4) In mismatching cases of lung cancer, perfusion was usually more impaired than ventilation. (author)

Xenon ventilation-perfusion lung scans. The early diagnosis of inhalation injury

International Nuclear Information System (INIS)

Schall, G.L.; McDonald, H.D.; Carr, L.B.; Capozzi, A.

1978-01-01

The use of xenon Xe-133 ventilation-perfusion lung scans for the early diagnosis of inhalation injury was evaluated in 67 patients with acute thermal burns. Study results were interpreted as normal if there was complete pulmonary clearance of the radioactive gas by 150 seconds. Thirty-two scans were normal, 32 abnormal, and three technically inadequate. There were three true false-positive study results and one false-negative study result. Good correlation was found between the scan results and various historical, physical, and laboratory values currently used to evaluate inhalation injury. The scans appeared to be the most sensitive method for the detection of early involvement, often being abnormal several days before the chest roentgenogram. Xenon lung scanning is a safe, easy, accurate, and sensitive method for the early diagnosis of inhalation injury and has important therapeutic and prognostic implications as well

High-resolution pulmonary ventilation and perfusion PET/CT allows for functionally adapted intensity modulated radiotherapy in lung cancer

International Nuclear Information System (INIS)

Siva, Shankar; Thomas, Roshini; Callahan, Jason; Hardcastle, Nicholas; Pham, Daniel; Kron, Tomas; Hicks, Rodney J.; MacManus, Michael P.; Ball, David L.; Hofman, Michael S.

2015-01-01

Background and purpose: To assess the utility of functional lung avoidance using IMRT informed by four-dimensional (4D) ventilation/perfusion (V/Q) PET/CT. Materials and methods: In a prospective clinical trial, patients with non-small cell lung cancer (NSCLC) underwent 4D-V/Q PET/CT scanning before 60 Gy of definitive chemoradiation. Both “highly perfused” (HPLung) and “highly ventilated” (HVLung) lung volumes were delineated using a 70th centile SUV threshold, and a “ventilated lung volume” (VLung) was created using a 50th centile SUV threshold. For each patient four IMRT plans were created, optimised to the anatomical lung, HPLung, HVLung and VLung volumes, respectively. Improvements in functional dose volumetrics when optimising to functional volumes were assessed using mean lung dose (MLD), V5, V10, V20, V30, V40, V50 and V60 parameters. Results: The study cohort consisted of 20 patients with 80 IMRT plans. Plans optimised to HPLung resulted in a significant reduction of functional MLD by a mean of 13.0% (1.7 Gy), p = 0.02. Functional V5, V10 and V20 were improved by 13.2%, 7.3% and 3.8% respectively (p-values < 0.04). There was no significant sparing of dose to functional lung when adapting to VLung or HVLung. Plan quality was highly consistent with a mean PTV D95 and D5 ranging from 60.8 Gy to 61.0 Gy and 63.4 Gy to 64.5 Gy, respectively, and mean conformity and heterogeneity index ranging from 1.11 to 1.17 and 0.94 to 0.95, respectively. Conclusion: IMRT plans adapted to perfused but not ventilated lung on 4D-V/Q PET/CT allowed for reduced dose to functional lung whilst maintaining consistent plan quality

Ventilation and perfusion imaging by electrical impedance tomography: a comparison with radionuclide scanning.

Science.gov (United States)

Kunst, P W; Vonk Noordegraaf, A; Hoekstra, O S; Postmus, P E; de Vries, P M

1998-11-01

Electrical impedance tomography (EIT) is a technique that makes it possible to measure ventilation and pulmonary perfusion in a volume that approximates to a 2D plane. The possibility of using EIT for measuring the left-right division of ventilation and perfusion was compared with that of radionuclide imaging. Following routine ventilation (81mKr) and perfusion scanning (99mTc-MAA), EIT measurements were performed at the third and the sixth intercostal level in 14 patients with lung cancer. A correlation (r = 0.98, p RC) was calculated for estimating the left-right division with EIT. The RC for the ventilation measurements was 94% and 96% for the perfusion measurements. The correlation analysis for reproducibility of the EIT measurements was 0.95 (p < 0.001) for the ventilation and 0.93 (p < 0.001) for the perfusion measurements. In conclusion, EIT can be regarded as a promising technique to estimate the left-right division of pulmonary perfusion and ventilation.

Quantitative lung perfusion evaluation using Fourier decomposition perfusion MRI.

Science.gov (United States)

Kjørstad, Åsmund; Corteville, Dominique M R; Fischer, Andre; Henzler, Thomas; Schmid-Bindert, Gerald; Zöllner, Frank G; Schad, Lothar R

2014-08-01

To quantitatively evaluate lung perfusion using Fourier decomposition perfusion MRI. The Fourier decomposition (FD) method is a noninvasive method for assessing ventilation- and perfusion-related information in the lungs, where the perfusion maps in particular have shown promise for clinical use. However, the perfusion maps are nonquantitative and dimensionless, making follow-ups and direct comparisons between patients difficult. We present an approach to obtain physically meaningful and quantifiable perfusion maps using the FD method. The standard FD perfusion images are quantified by comparing the partially blood-filled pixels in the lung parenchyma with the fully blood-filled pixels in the aorta. The percentage of blood in a pixel is then combined with the temporal information, yielding quantitative blood flow values. The values of 10 healthy volunteers are compared with SEEPAGE measurements which have shown high consistency with dynamic contrast enhanced-MRI. All pulmonary blood flow (PBF) values are within the expected range. The two methods are in good agreement (mean difference = 0.2 mL/min/100 mL, mean absolute difference = 11 mL/min/100 mL, mean PBF-FD = 150 mL/min/100 mL, mean PBF-SEEPAGE = 151 mL/min/100 mL). The Bland-Altman plot shows a good spread of values, indicating no systematic bias between the methods. Quantitative lung perfusion can be obtained using the Fourier Decomposition method combined with a small amount of postprocessing. Copyright © 2013 Wiley Periodicals, Inc.

Regional lung function evaluation with nitrogen-13

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Ahluwalia, B; Brownell, G L; Hales, C; Kazemi, H

1981-10-01

Regional ventilation and perfusion studies are routinely performed with molecular nitrogen-13 (a short-lived positron emitter), a multicrystal positron camera, and a computer. These studies have the advantage of viewing with equal sensitivity all sections of the lung simultaneously. Nitrogen-13 is less soluble than xenon in blood and therefore allows more accurate ventilation imaging. The short half-life of the radiopharmaceutical allows simultaneous ventilation and perfusion scintigraphy of the lung. Unlike other imaging techniques in which the residual radioactivity persists in the lung for hours, nitrogen-13 is rapidly cleared allowing repetitive imaging. Ventilation and perfusion studies are part of the routine preoperative evaluation for lung cancer resection or for bullectomy in patients with chronic obstructive pulmonary disease and for assessment of pulmonary emboli in the presence of chronic obstructive disease.

Value of chest X-ray combined with perfusion scan versus ventilation/perfusion scan in acute pulmonary embolism

NARCIS (Netherlands)

de Groot, M. R.; Turkstra, F.; van Marwijk Kooy, M.; Oostdijk, A. H.; van Beek, E. J.; Büller, H. R.

2000-01-01

The main purpose of ventilation scanning, as adjunct to perfusion lung scintigraphy, in acute pulmonary embolism is to allow for the classification of segmental perfusion defects as mismatched, which is generally accepted as proof for the presence of pulmonary embolism. We examined whether this

Regional ventilation/perfusion mismatch pattern in patient with Swyer James (MacLeod′s syndrome

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Sait Sager

2014-01-01

Full Text Available Swyer James (McLeod′s syndrome (SJMS is an uncommon disease, which occurs as a result of childhood bronchiolitis obliterans. Patients may not be diagnosed until later in their life. A 46-year-old man underwent ventilation/perfusion scintigraphy for acute onset of dyspnea. The scan showed markedly diminished ventilation and perfusion unilaterally on the right middle and inferior lobes. However, mismatched ventilation-perfusion pattern was shown on the upper right lobe, which was consistent with pulmonary embolism. Unilaterally matched ventilation/perfusion defect can see in SJMS in lung scintigraphy; however, when pulmoner embolism may accompany, scintigraphy should be carefully examined.

A Short Period of Ventilation without Perfusion Seems to Reduce Atelectasis without Harming the Lungs during Ex Vivo Lung Perfusion

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Sandra Lindstedt

2013-01-01

Full Text Available To evaluate the lung function of donors after circulatory deaths (DCDs, ex vivo lung perfusion (EVLP has been shown to be a valuable method. We present modified EVLP where lung atelectasis is removed, while the lung perfusion is temporarily shut down. Twelve pigs were randomized into two groups: modified EVLP and conventional EVLP. When the lungs had reached 37°C in the EVLP circuit, lung perfusion was temporarily shut down in the modified EVLP group, and positive end-expiratory pressure (PEEP was increased to 10 cm H2O for 10 minutes. In the conventional EVLP group, PEEP was increased to 10 cm H2O for 10 minutes with unchanged lung perfusion. In the modified EVLP group, the arterial oxygen partial pressure (PaO2 was 18.5 ± 7.0 kPa before and 64.5 ± 6.0 kPa after the maneuver (P<0.001. In the conventional EVLP group, the PaO2 was 16.8 ± 3.1 kPa and 46.8 ± 2.7 kPa after the maneuver (P<0.01; P<0.01. In the modified EVLP group, the pulmonary graft weight was unchanged, while in the conventional EVLP group, the pulmonary graft weight was significantly increased. Modified EVLP with normoventilation of the lungs without ongoing lung perfusion for 10 minutes may eliminate atelectasis almost completely without harming the lungs.

Prediction of postoperative pulmonary function following thoracic operations. Value of ventilation-perfusion scanning

International Nuclear Information System (INIS)

Bria, W.F.; Kanarek, D.J.; Kazemi, H.

1983-01-01

Surgical resection of lung cancer is frequently required in patients with severely impaired lung function resulting from chronic obstructive pulmonary disease. Twenty patients with obstructive lung disease and cancer (mean preoperative forced expiratory volume in 1 second [FEV1] . 1.73 L) were studied preoperatively and postoperatively by spirometry and radionuclide perfusion, single-breath ventilation, and washout techniques to test the ability of these methods to predict preoperatively the partial loss of lung function by the resection. Postoperative FEV1 and forced vital capacity (FVC) were accurately predicted by the formula: postoperative FEV1 (or FVC) . preoperative FEV1 X percent function of regions of lung not to be resected (r . 0.88 and 0.95, respectively). Ventilation and perfusion scans are equally effective in prediction. Washout data add to the sophistication of the method by permitting the qualitative evaluation of ventilation during tidal breathing. Criteria for patients requiring the study are suggested

Ventilation-perfusion-lungscintigraphy using PET and {sup 68}Ga-labeled radiopharmaceuticals; Ventilations-Perfusions-Lungenszintigraphie mit der PET und {sup 68}Ga-markierten Radiopharmaka

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Kotzerke, J. [Technische Univ. Dresden (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Technische Univ. Dresden (Germany). OncoRay - Zentrum fuer Innovationskompetenz Strahlenforschung in der Onkologie; Forschungszentrum Dresden-Rossendorf e.V. (FZR) (Germany). PET-Zentrum; Andreeff, M.; Wunderlich, G.; Zoephel, K. [Technische Univ. Dresden (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Wiggermann, P. [Technische Univ. Dresden (Germany). Inst. und Poliklinik fuer Diagnostische Radiologie

2010-07-01

Aim: Imaging of lung perfusion with positron emission tomography (PET) is already possible with {sup 68}Ga labeled denaturized albumin. The purpose of our study was to produce and test a {sup 68}Ga labeled aerosol (Galligas {sup registered}) for ventilation and {sup 68}Ga labeled albumin particles (microspheres) for perfusion imaging with PET. Patients, methods: Galligas was produced by simmering and burning generator eluted {sup 68}Ga solution (100 MBq/0.1ml) in an ordinary technegas generator. Fifteen patients with suspicion on pulmonary embolism underwent PET/CT (Biograph 16) after inhalation of Galligas and application of {sup 68}Ga labeled microspheres. A low dose CT was acquired for attenuation correction (AC). Images were reconstructed with and without AC. The inhaled activity was calculated compared to the activity injected. Results: Inhaled radioaerosol Galligas demonstrated typical distribution as known from {sup 99m}Tc-labeled technegas with homogeneous distribution in lung without hilar deposits. Attenuation corrected images resulted in artefacts in the lung base. Therefore, non-corrected images were used for making the results. Three out of fifteen patients showed a deficient perfusion whereas ventilation was normal corresponding to pulmonary embolism. Conclusion: Lung scintigraphy with PET is feasible. Galligas is simple to produce (analogously to technegas). {sup 68}Ga labeled microspheres are available. The method is applicable to daily routine and rendered clinically relevant informations. (orig.)

Ventilation/perfusion scintigraphy in children with post-infectious bronchiolitis obliterans: a pilot study.

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Bo-Qia Xie

Full Text Available PURPOSE: Childhood post-infectious bronchiolitis obliterans (BO is an infrequent lung disease leading to narrowing and/or complete obliteration of small airways. Ventilation and perfusion (V/Q scan can provide both regional and global pulmonary information. However, only few retrospective researches investigating post-infectious BO involved V/Q scan, the clinical value of this method is unknown. This preliminary prospective study was aimed to evaluate the correlation of V/Q scan with disease severity, pulmonary function test results, and prognosis in children with post-infectious BO. METHODS: Twenty-five post-infectious BO children (18 boys and 7 girls; mean age, 41 months underwent V/Q scan and pulmonary function tests. Patients were followed after their inclusion. Ventilation index and perfusion index obtained from V/Q scan were used to measure pulmonary abnormalities. Spearman's rank correlation test of ventilation index and perfusion index on disease severity, lung function tests indices, and follow-up results were performed. RESULTS: The median follow-up period was 4.6 years (range, 2.2 to 5.0 years. Ventilation index and perfusion index were both correlated with disease severity (r = 0.72, p<0.01 and r = 0.73, p<0.01, but only ventilation index was related to pulmonary function tests results (all p<0.05. In addition, Spearman test yielded significant correlations between perfusion index and prognosis (r = 0.77, p<0.01, and ventilation index and prognosis (r = 0.63, p = 0.01. CONCLUSIONS: For children with post-infectious BO, the present study preliminarily indicated that the degree of ventilation and perfusion abnormalities evaluated by V/Q scan may be used to assess disease severity, and may be predictive of patient's outcome.

Correlation of 68Ga Ventilation-Perfusion PET/CT with Pulmonary Function Test Indices for Assessing Lung Function.

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Le Roux, Pierre-Yves; Siva, Shankar; Steinfort, Daniel P; Callahan, Jason; Eu, Peter; Irving, Lou B; Hicks, Rodney J; Hofman, Michael S

2015-11-01

Pulmonary function tests (PFTs) are routinely used to assess lung function, but they do not provide information about regional pulmonary dysfunction. We aimed to assess correlation of quantitative ventilation-perfusion (V/Q) PET/CT with PFT indices. Thirty patients underwent V/Q PET/CT and PFT. Respiration-gated images were acquired after inhalation of (68)Ga-carbon nanoparticles and administration of (68)Ga-macroaggregated albumin. Functional volumes were calculated by dividing the volume of normal ventilated and perfused (%NVQ), unmatched and matched defects by the total lung volume. These functional volumes were correlated with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, and diffusing capacity for carbon monoxide (DLCO). All functional volumes were significantly different in patients with chronic obstructive pulmonary disease (P volume of unmatched defects (r = -0.55). Considering %NVQ only, a cutoff value of 90% correctly categorized 28 of 30 patients with or without significant pulmonary function impairment. Our study demonstrates strong correlations between V/Q PET/CT functional volumes and PFT parameters. Because V/Q PET/CT is able to assess regional lung function, these data support the feasibility of its use in radiation therapy and preoperative planning and assessing pulmonary dysfunction in a variety of respiratory diseases. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Lung perfusion and ventilation scintigraphy in pre- and postoperative diagnostics; Lungenperfusions- und Ventilationsszintigraphie in der prae- und postoperativen Diagnostik

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Sandrock, D.; Munz, D.L. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Charite, Medizinische Fakultaet der Humboldt-Univ. zu Berlin (Germany)

1998-03-01

Lung perfusion (Tc-99m labeled albumin particles) and ventilation (Xe-133 gas) are used prior to thoracic surgery in order to evaluate changes in perfusion and ventilation due to the underlying diseases. Furthermore, perfusion scintigraphy allows combined with spirometry the prediction of the postinterventional vital capacity and the forced expiratory volume in 1 s. The correlation coefficient for this procedure compared with values measured postoperatively are in the range of 0.8. The method allows the assessment of operability in terms of postinterventional function. (orig.) [Deutsch] Die Lungenperfusions- (mit Tc-99m-markierten Albuminpartikeln) und die Ventilationsszintigraphie (mit Xe-133 als Gas) werden vor thoraxchirugrischen Eingriffen zur Beurteilung der durch die Grund- oder weitere Erkrankungen bedingte Einschraenkungen von Perfusion und Belueftung eingesetzt. Die Perfusionsszintigraphie erlaubt in Kombination mit der Spirometrie ausserdem die Vorausberechnung der postoperativ zu erwartenden Vitalkapazitaet und des forcierten exspiratorischen Erstsekundenvolumens. Im Vergleich mit den postoperativ gemessenen Volumina liegen die Korrelationskoeffizienten um 0,8. Die Methode ermoeglicht daher eine Beurteilung der Operabilitaet bezueglich der postoperativen Lungenfunktion. (orig.)

Diagnosis of thromboembolic disease: combined ventilation perfusion lung scan and compression ultrasonography

International Nuclear Information System (INIS)

Dadparvar, S.; Woods, K.; Magno, R.M.; Sabatino, J. C.; Patil, S.; Dou, Y.

2002-01-01

The clinical management of pulmonary embolism and deep venous thrombosis of the legs are similar and require prolonged anticoagulation therapy. The standard diagnostic approach in patients suspected of pulmonary embolism is ventilation-perfusion (V/Q) lung scan and compression ultrasonography to detect deep venous thrombosis. This retrospective study analyzed the role of V Q lung scan and compression ultrasonography in detection of thromboembolic disease. One hundred-twenty consecutive patients (65 female, 55 male) age range 18-95 (mean age 60.7) suspected for pulmonary embolism underwent concomitant V/Q lung scan and compression ultrasonography of the lower extremities. The clinical and radiographic correlation was performed. Of patients with non-diagnostic (low or intermediate probability ) lung scans, 15.4 % (14/91) received anticoagulation therapy for pulmonary embolism. This patients had either high pre-clinical suspicion for PE or underwent pulmonary arterio gram. However, there was an additional 7 % (7/91) increase in the number of patients who received anticoagulation therapy based on the results of ultrasound with confidence interval (3 %-16 %). We conclude that V/Q lung scan is a more sensitive examination for thromboembolic disease, and has a high negative predictive value. Ultrasonography of lower extremities demonstrated higher specificity and positive value. Among patients with non-diagnostic lung scan, the detection rate of thromboembolic disease is improved with addition of ultrasound

The relationship between ventilatory lung motion and pulmonary perfusion shown by ventilatory lung motion imaging

International Nuclear Information System (INIS)

Fujii, Tadashige; Tanaka, Masao; Nakatsuka, Tatsuya; Yoshimura, Kazuhiko; Hirose, Yoshiki; Hirayama, Jiro; Kobayashi, Toshio; Handa, Kenjiro

1991-01-01

Using ventilatory lung motion imaging, which was obtained from two perfusion lung scintigrams with 99m Tc-macroaggregated albumin taken in maximal inspiration and maximal expiration, the lung motion (E-I/I) of the each unilateral lung was studied in various cardiopulmonary diseases. The sum of (E-I)/I(+) of the unilateral lung was decreased in the diseased lung for localized pleuropulmonary diseases, including primary lung cancer and pleural thickening, and in both lungs for heart diseases, and diffuse pulmonary diseases including diffuse interstitial pneumonia and diffuse panbronchiolitis. The sum of (E-I)/I(+) of the both lungs, which correlated with vital capacity and PaO 2 , was decreased in diffuse interstitial pneumonia, pulmonary emphysema, diffuse panbronchiolitis, primary lung cancer, pleural diseases and so on. (E-I)/I(+), correlated with pulmonary perfusion (n=49, r=0.51, p 81m Kr or 133 Xe (n=49, r=0.61, p<0.001) than pulmonary perfusion. The ventilatory lung motion imaging, which demonstrates the motion of the intra-pulmonary areas and lung edges, appears useful for estimating pulmonary ventilation of the perfused area as well as pulmonary perfusion. (author)

Studies on pulmonary ventilation-perfusion scintigraphy with Xe-133 in primary lung cancer, 1

International Nuclear Information System (INIS)

Oshibuchi, Masao

1984-01-01

Regional lung ventilation-perfusion scintigraphy by xenon gas was performed on 14 normal cases (normal group) and 86 cases of primary lung cancer (lung cancer group). The patients were measured in a sitting position using a scintillation camera. In normal group, the value of V, Q was higher in the lower lung field than in the upper lung field, the value of MTT was rather delayed in the upper lung field than in the lower lung field, proving to that lung clearance was better in the lower lung field than in the upper lung field. In lung cancer group, VQ match (pattern I, II) was 61 cases (71%) and VQ mismatch (pattern III, IV) was 25 cases (29%). The pattern II (VQ matched defect) accounted for 63% in lung cancer group. In this pattern, the region of disorder of V and Q was corresponded respectively, but disorder grade was not always accorded. The pattern III (normal V and disordered Q) was mainly seen in AH group (hilar type) and D group (lymph node swelling type). The V/Q in lung cancer group was widely distributed to the range of 0 to 5.8. The value of MTT was rather delayed in all cases of lung cancer group than in the normal group, because delayed MTT in focal lesion was markedly affected to whole lung. (author)

Comparison of 4-Dimensional Computed Tomography Ventilation With Nuclear Medicine Ventilation-Perfusion Imaging: A Clinical Validation Study

International Nuclear Information System (INIS)

Vinogradskiy, Yevgeniy; Koo, Phillip J.; Castillo, Richard; Castillo, Edward; Guerrero, Thomas; Gaspar, Laurie E.; Miften, Moyed; Kavanagh, Brian D.

2014-01-01

Purpose: Four-dimensional computed tomography (4DCT) ventilation imaging provides lung function information for lung cancer patients undergoing radiation therapy. Before 4DCT-ventilation can be implemented clinically it needs to be validated against an established imaging modality. The purpose of this work was to compare 4DCT-ventilation to nuclear medicine ventilation, using clinically relevant global metrics and radiologist observations. Methods and Materials: Fifteen lung cancer patients with 16 sets of 4DCT and nuclear medicine ventilation-perfusion (VQ) images were used for the study. The VQ-ventilation images were acquired in planar mode using Tc-99m-labeled diethylenetriamine-pentaacetic acid aerosol inhalation. 4DCT data, spatial registration, and a density-change-based model were used to compute a 4DCT-based ventilation map for each patient. The percent ventilation was calculated in each lung and each lung third for both the 4DCT and VQ-ventilation scans. A nuclear medicine radiologist assessed the VQ and 4DCT scans for the presence of ventilation defects. The VQ and 4DCT-based images were compared using regional percent ventilation and radiologist clinical observations. Results: Individual patient examples demonstrate good qualitative agreement between the 4DCT and VQ-ventilation scans. The correlation coefficients were 0.68 and 0.45, using the percent ventilation in each individual lung and lung third, respectively. Using radiologist-noted presence of ventilation defects and receiver operating characteristic analysis, the sensitivity, specificity, and accuracy of the 4DCT-ventilation were 90%, 64%, and 81%, respectively. Conclusions: The current work compared 4DCT with VQ-based ventilation using clinically relevant global metrics and radiologist observations. We found good agreement between the radiologist's assessment of the 4DCT and VQ-ventilation images as well as the percent ventilation in each lung. The agreement lessened when the data were

Significance of single ventilation/perfusion mismatches in krypton-81m/technetium-99m lung scintigraphy

International Nuclear Information System (INIS)

Rosen, J.M.; Palestro, C.J.; Markowitz, D.; Alderson, P.O.

1986-01-01

The significance of a single area of ventilation/perfusion (V/P) mismatch in lung scans performed on patients suspected of pulmonary embolism (PE) was evaluated. Ten of 20 patients with this scan finding were found to have PE. An intermediate probability of PE was found with segmental (71%) or subsegmental (45%) single V/P mismatches. Seven of 16 patients with a single V/P mismatch and without a matching radiographic opacity had PE. Three of the four patients who had a V/P mismatch and a matching radiographic opacity were found to have PE. Multiview ventilation imaging with 81mKr was found to have advantages for the evaluation of single V/P mismatches. Based on the data available at this time, a single V/P mismatch suggests an intermediate probability of PE

sup(99m)Tc particle perfusion/sup(99m)Tc aerosol ventilation imaging using a subtraction technique in suspected pulmonary embolism

International Nuclear Information System (INIS)

Poeyhoenen, L.; Turjanmaa, V.; Virjo, A.

1985-01-01

It is generally acknowledged that ventilation-perfusion mismatch is diagnostic of pulmonary embolism. Lung ventilation imaging with radioactive gases is a good method for the detection of pulmonary embolism, but it is not in widespread use because of the limited availability of sup(81m)Kr gas and the poor physical properties of 133 Xe. Aerosols have been proposed, instead of gases for use in lung ventilation imaging. As perfusion and ventilation distributions may change very rapidly, the two imaging procedures should be done in rapid succession. The cheapest way to perform the combined perfusion-ventilation (Q/V) imaging is to use sup(99m)Tc-labelled macroaggregates and aerosols. In our method the perfusion imaging was done first, immediately followed by the ventilation imaging with sup(99m)Tc-labelled aerosols. A computer program was used to subtract the contribution of the perfusion from the combined Q/V image so that the pure ventilation image alone was obtained. The method was tested in 41 patients with suspected pulmonary embolism. (orig.)

The matching of ventilation and perfusion in the lung of the Tegu lizard, Tupinambis nigropunctatus.

Science.gov (United States)

Hlastala, M P; Standaert, T A; Pierson, D J; Luchtel, D L

1985-06-01

Ventilation-perfusion (VA/Q) distribution was evaluated in the Tegu lizard, Tupinambis nigropunctatus, using the multiple inert gas elimination technique (MIGET) in order to define the limitations to gas exchange in the large chambered unicameral lung. The lizards (0.52-1.1 kg) were anesthetized with halothane and ventilated. Body temperature was maintained at 35 degrees C. Arterial and sinus venosus PO2 averaged 79.4 +/- 5.9 and 47.3 +/- 6.4 torr while breathing air and 232.1 +/- 31 and 64.8 +/- 11.5 torr while breathing oxygen. VA/Q distributions were broad and right-to-left shunt averaged 21% while breathing air and 27% while breathing oxygen. Gas exchange was significantly impaired due to the presence of both shunt and VA/Q heterogeneity. The walls of the lung enclose a large axial air chamber. Microscopic examination revealed approximately three generations of septa which subdivided the wall into tubular-shaped gas-exchange chambers. Wall thickness averages 2.8 mm at the anterior end of the lung, 2.1 mm in the middle portion of the lung and 1.4 mm at the posterior end. The thickness of the blood-air barrier (epithelial-basal lamina-endothelial cell layer) ranged from 0.35 to 0.90 micron. Although this barrier is slightly thicker than in the mammalian lung (0.1-0.5 micron), it is unlikely to be a source of diffusion limitation in gas exchange at rest.

Spatial correspondence of 4D CT ventilation and SPECT pulmonary perfusion defects in patients with malignant airway stenosis

Science.gov (United States)

Castillo, Richard; Castillo, Edward; McCurdy, Matthew; Gomez, Daniel R.; Block, Alec M.; Bergsma, Derek; Joy, Sarah; Guerrero, Thomas

2012-04-01

To determine the spatial overlap agreement between four-dimensional computed tomography (4D CT) ventilation and single photon emission computed tomography (SPECT) perfusion hypo-functioning pulmonary defect regions in a patient population with malignant airway stenosis. Treatment planning 4D CT images were obtained retrospectively for ten lung cancer patients with radiographically demonstrated airway obstruction due to gross tumor volume. Each patient also received a SPECT perfusion study within one week of the planning 4D CT, and prior to the initiation of treatment. Deformable image registration was used to map corresponding lung tissue elements between the extreme component phase images, from which quantitative three-dimensional (3D) images representing the local pulmonary specific ventilation were constructed. Semi-automated segmentation of the percentile perfusion distribution was performed to identify regional defects distal to the known obstructing lesion. Semi-automated segmentation was similarly performed by multiple observers to delineate corresponding defect regions depicted on 4D CT ventilation. Normalized Dice similarity coefficient (NDSC) indices were determined for each observer between SPECT perfusion and 4D CT ventilation defect regions to assess spatial overlap agreement. Tidal volumes determined from 4D CT ventilation were evaluated versus measurements obtained from lung parenchyma segmentation. Linear regression resulted in a linear fit with slope = 1.01 (R2 = 0.99). Respective values for the average DSC, NDSC1 mm and NDSC2 mm for all cases and multiple observers were 0.78, 0.88 and 0.99, indicating that, on average, spatial overlap agreement between ventilation and perfusion defect regions was comparable to the threshold for agreement within 1-2 mm uncertainty. Corresponding coefficients of variation for all metrics were similarly in the range: 0.10%-19%. This study is the first to quantitatively assess 3D spatial overlap agreement between

Clinical significance of ventilation/perfusion scans in collagen disease patients

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Suzuki, Kenzo; Kobayashi, Takeshi [Tokyo Metropolitan Hiro-o Hospital (Japan); Kamata, Noriko; Inokuma, Shigeko; Terada, Hitoshi; Yokoyama, Yoshiaki; Abe, Katsumi; Mochizuki, Takao

2000-12-01

The purpose of this study was to detect disturbances in pulmonary circulation in collagen disease patients by means of a non-invasive technique. Ventilation/perfusion scans with {sup 133}Xe gas and {sup 99m}Tc-macroaggregated albumin (MAA) were performed in 109 patients with various collagen diseases. Functional images of V, Vol, Q and V/Q ratio were obtained at total lung capacity. Wash-out time was calculated from the wash-out curve. Whole body scans were performed in 65 patients to evaluate intra-pulmonary shunts. Increased V/Q areas were observed in 74 patients (67.9%), suggesting some impairment of pulmonary perfusion. Decreased perfusion, probably due to vasculitis or intravascular microcoagulation, was observed often, even in patients without pulmonary fibrosis. Shunt ratios over 10% were observed in 8 of the 65 patients (12.3%), indicating formation of PA-PV shunts secondary to peripheral vascular impairment. Wash-out time was prolonged in 37 patients (33.9%), shortened in 18 (16.5%), and within the normal range in 54 (49.6%). The prolonged and normal wash-out times in the patients with pulmonary fibrosis may represent obstructive changes in the small airways superimposed on the fibrosis. Ventilation/perfusion scans are a very useful tool for evaluating collagen lung diseases, and they might contribute to treatment decisions for the patients. (author)

Independent lung ventilation in a newborn with asymmetric acute lung injury due to respiratory syncytial virus: a case report

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Di Nardo Matteo

2008-06-01

Full Text Available Abstract Introduction Independent lung ventilation is a form of protective ventilation strategy used in adult asymmetric acute lung injury, where the application of conventional mechanical ventilation can produce ventilator-induced lung injury and ventilation-perfusion mismatch. Only a few experiences have been published on the use of independent lung ventilation in newborn patients. Case presentation We present a case of independent lung ventilation in a 16-day-old infant of 3.5 kg body weight who had an asymmetric lung injury due to respiratory syncytial virus bronchiolitis. We used independent lung ventilation applying conventional protective pressure controlled ventilation to the less-compromised lung, with a respiratory frequency proportional to the age of the patient, and a pressure controlled high-frequency ventilation to the atelectatic lung. This was done because a single tube conventional ventilation protective strategy would have exposed the less-compromised lung to a high mean airways pressure. The target of independent lung ventilation is to provide adequate gas exchange at a safe mean airways pressure level and to expand the atelectatic lung. Independent lung ventilation was accomplished for 24 hours. Daily chest radiograph and gas exchange were used to evaluate the efficacy of independent lung ventilation. Extubation was performed after 48 hours of conventional single-tube mechanical ventilation following independent lung ventilation. Conclusion This case report demonstrates the feasibility of independent lung ventilation with two separate tubes in neonates as a treatment of an asymmetric acute lung injury.

The effects of exogenous surfactant administration on ventilation-induced inflammation in mouse models of lung injury.

Science.gov (United States)

Puntorieri, Valeria; Hiansen, Josh Qua; McCaig, Lynda A; Yao, Li-Juan; Veldhuizen, Ruud A W; Lewis, James F

2013-11-20

Mechanical ventilation (MV) is an essential supportive therapy for acute lung injury (ALI); however it can also contribute to systemic inflammation. Since pulmonary surfactant has anti-inflammatory properties, the aim of the study was to investigate the effect of exogenous surfactant administration on ventilation-induced systemic inflammation. Mice were randomized to receive an intra-tracheal instillation of a natural exogenous surfactant preparation (bLES, 50 mg/kg) or no treatment as a control. MV was then performed using the isolated and perfused mouse lung (IPML) set up. This model allowed for lung perfusion during MV. In experiment 1, mice were exposed to mechanical ventilation only (tidal volume =20 mL/kg, 2 hours). In experiment 2, hydrochloric acid or air was instilled intra-tracheally four hours before applying exogenous surfactant and ventilation (tidal volume =5 mL/kg, 2 hours). For both experiments, exogenous surfactant administration led to increased total and functional surfactant in the treated groups compared to the controls. Exogenous surfactant administration in mice exposed to MV only did not affect peak inspiratory pressure (PIP), lung IL-6 levels and the development of perfusate inflammation compared to non-treated controls. Acid injured mice exposed to conventional MV showed elevated PIP, lung IL-6 and protein levels and greater perfusate inflammation compared to air instilled controls. Instillation of exogenous surfactant did not influence the development of lung injury. Moreover, exogenous surfactant was not effective in reducing the concentration of inflammatory cytokines in the perfusate. The data indicates that exogenous surfactant did not mitigate ventilation-induced systemic inflammation in our models. Future studies will focus on altering surfactant composition to improve its immuno-modulating activity.

A new positive pressure ventilation delivery system: its impact on lung ventilation studies that are technically inadequate or non diagnostic

International Nuclear Information System (INIS)

Bui, C.; Leiper, C.; Lee, K.; Saunders, C.; Dixson, H.; Elison, B.; Bennett, G.; Gibian, T.; Rutland, J.; Tse, V.; Elzein, H.; Babicheva, R.

2000-01-01

Full text: The objective of this study was to evaluate the efficacy and safety of an improved Positive Pressure Ventilation Delivery System (PVDS) in the investigation of Pulmonary Embolism (PE). The major component of PVDS is a commercially available, self-inflating 1.6L Hudson Resuscitator Bag, filled with either oxygen or air (if the patient has CO 2 retention), which is squeezed by the operator to push Technegas from the Technegas Generator Chamber to the patient via the Patient Administration Set synchronously with patient inspiration. 27 spontaneously breathing in-patients (12 males, 15 females, age range 64-89, 21 with chronic airflow limitation), whose conventional lung ventilation images were technically inadequate or non diagnostic, were re-scanned using PVDS within four days after the conventional ventilation study. Randomised blinded visual interpretation of conventional ventilation/perfusion scan vs. PVDS-assisted ventilation/perfusion scan was performed by consensus reading with two experienced observers. In conclusion PVDS was safe and well tolerated. PVDS improved the image quality of the lung ventilation scans in this cohort of patients. This technique has the potential to improve the accuracy of lung scanning in patients with severe lung disease. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

Ventilation/perfusion SPECT/CT in patients with pulmonary emphysema. Evaluation of software-based analysing.

Science.gov (United States)

Schreiter, V; Steffen, I; Huebner, H; Bredow, J; Heimann, U; Kroencke, T J; Poellinger, A; Doellinger, F; Buchert, R; Hamm, B; Brenner, W; Schreiter, N F

2015-01-01

The purpose of this study was to evaluate the reproducibility of a new software based analysing system for ventilation/perfusion single-photon emission computed tomography/computed tomography (V/P SPECT/CT) in patients with pulmonary emphysema and to compare it to the visual interpretation. 19 patients (mean age: 68.1 years) with pulmonary emphysema who underwent V/P SPECT/CT were included. Data were analysed by two independent observers in visual interpretation (VI) and by software based analysis system (SBAS). SBAS PMOD version 3.4 (Technologies Ltd, Zurich, Switzerland) was used to assess counts and volume per lung lobe/per lung and to calculate the count density per lung, lobe ratio of counts and ratio of count density. VI was performed using a visual scale to assess the mean counts per lung lobe. Interobserver variability and association for SBAS and VI were analysed using Spearman's rho correlation coefficient. Interobserver agreement correlated highly in perfusion (rho: 0.982, 0.957, 0.90, 0.979) and ventilation (rho: 0.972, 0.924, 0.941, 0.936) for count/count density per lobe and ratio of counts/count density in SBAS. Interobserver agreement correlated clearly for perfusion (rho: 0.655) and weakly for ventilation (rho: 0.458) in VI. SBAS provides more reproducible measures than VI for the relative tracer uptake in V/P SPECT/CTs in patients with pulmonary emphysema. However, SBAS has to be improved for routine clinical use.

Utilization of the organ care system as ex-vivo lung perfusion after cold storage transportation.

Science.gov (United States)

Mohite, P N; Maunz, O; Popov, A-F; Zych, B; Patil, N P; Simon, A R

2015-11-01

The Organ Care System (OCS) allows perfusion and ventilation of the donor lungs under physiological conditions. Ongoing trials to compare preservation with OCS Lung with standard cold storage do not include donor lungs with suboptimal gas exchange and donor lungs treated with OCS following cold storage transportation. We present a case of a 48-yr-old man who received such lungs after cold storage transportation treated with ex-vivo lung perfusion utilizing OCS. © The Author(s) 2015.

Validation of co-registration of clinical lung ventilation and perfusion SPECT

International Nuclear Information System (INIS)

Marsh, S.H.; O'Keeffe, D.S.; Barnden, L.R.

2010-01-01

Full text: This talk will present results from a recent validation study of coregistration of computed tomography ventilation and perfusion (SPECT V/Q) images. The coregistration algorithm was incorporated in Qonsub, a program to coregister, normalise and subtract the SPECT (V/Q) images. Ventilation and perfusion image data were acquired from 23 patients undergoing a routine clinical SPECT V/Q study. The only change to normal patient management was the placement of three Tc 9 9 m filled fiducial markers adhered to the skin on the patient's torso. To quantify coregistration accuracy, image data were modified (within software) to remove the markers and Qonsub determined a parameter set of six values fully describing the six degree rigid transformation. The accuracy with which the six parameters coregister the images was then quantified by applying the same transformation parameters to the ventilation markers and determining how well they locate to the perfusion marker positions. Results show that for 65% of patients surveyed co-registration accuracy was to within I pixel, 30% were co-registered with an accuracy between 1 and 2 pixels and 5% were co-registered with an accuracy of between 2 and 3 pixels. Because patient placement between scans resulted in a misregistration of at most five pixels, a more rigorous test of the algorithm was required. Ethics approval had not been sought to intentionally misregister patient images, so the algorithm had to be further tested by synthetically misregistering the images. For these images Qonsub generally co-registered with the same accuracy as the original image. (author)

Lung ventilation-perfusion imbalance in pulmonary emphysema: assessment with automated V/Q quotient SPECT.

Science.gov (United States)

Suga, Kazuyoshi; Kawakami, Yasuhiko; Koike, Hiroaki; Iwanaga, Hideyuki; Tokuda, Osamu; Okada, Munemasa; Matsunaga, Naofumi

2010-05-01

Tc-99m-Technegas-MAA single photon emission computed tomography (SPECT)-derived ventilation (V)/perfusion (Q) quotient SPECT was used to assess lung V-Q imbalance in patients with pulmonary emphysema. V/Q quotient SPECT and V/Q profile were automatically built in 38 patients with pulmonary emphysema and 12 controls, and V/Q distribution and V/Q profile parameters were compared. V/Q distribution on V/Q quotient SPECT was correlated with low attenuation areas (LAA) on density-mask computed tomography (CT). Parameters of V/Q profile such as the median, standard deviation (SD), kurtosis and skewness were proposed to objectively evaluate the severity of lung V-Q imbalance. In contrast to uniform V/Q distribution on V/Q quotient SPECT and a sharp peak with symmetrical V/Q distribution on V/Q profile in controls, lung areas showing heterogeneously high or low V/Q and flattened peaks with broadened V/Q distribution were frequently seen in patients with emphysema, including lung areas with only slight LAA. V/Q distribution was also often asymmetric regardless of symmetric LAA. All the proposed parameters of V/Q profile in entire lungs of patients with emphysema showed large variations compared with controls; SD and kurtosis were significantly different from controls (P emphysema. SD and kurtosis of V/Q profile can be adequate parameters to assess the severity of lung V-Q imbalance causing gas-exchange impairment in patients with emphysema.

Radiographic and radionuclide lung perfusion imaging in healthy calves and calves naturally infected with bovine respiratory syncytial virus

International Nuclear Information System (INIS)

Verhoeff, J.; Brom, W.E. van den; Ingh, T.S.G.A.M. van den

1992-01-01

Nine calves between three and 18 weeks old with serologically confirmed natural bovine respiratory syncytial virus infection were examined clinically, radiographically and by radionuclide lung perfusion imaging. The results were compared with those from seven healthy calves. The diseased calves were euthanased and examined pathologically, virologically and bacteriologically. The clinical signs indicated that the disease was in an acute stage. Radiography of the diseased animals revealed cysts, corresponding morphologically with bullous emphysema, and infiltrations roughly corresponding in distribution with atelectatic and, or, pneumonic areas. Radionuclide lung perfusion imaging revealed no perfusion shifts between the left and right lungs and a normal perfusion pattern in five of the nine diseased calves. The abnormalities in the perfusion patterns of three calves were probably caused by anatomical disorders such as cysts and pleural adhesions, but no cause of the abnormality could be found in one calf. These findings suggest that in calves infected with bovine respiratory syncytial virus, the normal perfusion pattern is maintained until anatomical disorders occur. The pathological examination and radiography revealed that the cranioventral lung fields were particularly poorly ventilated. This finding and the normal perfusion pattern indicate that these parts of the lungs are probably the sites where shuntings and perfusion-ventilation mismatchings occur

Oxidative lung injury correlates with one-lung ventilation time during pulmonary lobectomy: a study of exhaled breath condensate and blood.

Science.gov (United States)

García-de-la-Asunción, José; García-del-Olmo, Eva; Perez-Griera, Jaume; Martí, Francisco; Galan, Genaro; Morcillo, Alfonso; Wins, Richard; Guijarro, Ricardo; Arnau, Antonio; Sarriá, Benjamín; García-Raimundo, Miguel; Belda, Javier

2015-09-01

During lung lobectomy, the operated lung is collapsed and hypoperfused; oxygen deprivation is accompanied by reactive hypoxic pulmonary vasoconstriction. After lung lobectomy, ischaemia present in the collapsed state is followed by expansion-reperfusion and lung injury attributed to the production of reactive oxygen species. The primary objective of this study was to investigate the time course of several markers of oxidative stress simultaneously in exhaled breath condensate and blood and to determine the relationship between oxidative stress and one-lung ventilation time in patients undergoing lung lobectomy. This single-centre, observational, prospective study included 28 patients with non-small-cell lung cancer who underwent lung lobectomy. We measured the levels of hydrogen peroxide, 8-iso-PGF2α, nitrites plus nitrates and pH in exhaled breath condensate (n = 25). The levels of 8-iso-PGF2α and nitrites plus nitrates were also measured in blood (n = 28). Blood samples and exhaled breath condensate samples were collected from all patients at five time points: preoperatively; during one-lung ventilation, immediately before resuming two-lung ventilation; immediately after resuming two-lung ventilation; 60 min after resuming two-lung ventilation and 180 min after resuming two-lung ventilation. Both exhaled breath condensate and blood exhibited significant and simultaneous increases in oxidative-stress markers immediately before two-lung ventilation was resumed. However, all these values underwent larger increases immediately after resuming two-lung ventilation. In both exhaled breath condensate and blood, marker levels significantly and directly correlated with the duration of one-lung ventilation immediately before resuming two-lung ventilation and immediately after resuming two-lung ventilation. Although pH significantly decreased in exhaled breath condensate immediately after resuming two-lung ventilation, these pH values were inversely correlated with the

Ventilation-perfusion distribution in normal subjects.

Science.gov (United States)

Beck, Kenneth C; Johnson, Bruce D; Olson, Thomas P; Wilson, Theodore A

2012-09-01

Functional values of LogSD of the ventilation distribution (σ(V)) have been reported previously, but functional values of LogSD of the perfusion distribution (σ(q)) and the coefficient of correlation between ventilation and perfusion (ρ) have not been measured in humans. Here, we report values for σ(V), σ(q), and ρ obtained from wash-in data for three gases, helium and two soluble gases, acetylene and dimethyl ether. Normal subjects inspired gas containing the test gases, and the concentrations of the gases at end-expiration during the first 10 breaths were measured with the subjects at rest and at increasing levels of exercise. The regional distribution of ventilation and perfusion was described by a bivariate log-normal distribution with parameters σ(V), σ(q), and ρ, and these parameters were evaluated by matching the values of expired gas concentrations calculated for this distribution to the measured values. Values of cardiac output and LogSD ventilation/perfusion (Va/Q) were obtained. At rest, σ(q) is high (1.08 ± 0.12). With the onset of ventilation, σ(q) decreases to 0.85 ± 0.09 but remains higher than σ(V) (0.43 ± 0.09) at all exercise levels. Rho increases to 0.87 ± 0.07, and the value of LogSD Va/Q for light and moderate exercise is primarily the result of the difference between the magnitudes of σ(q) and σ(V). With known values for the parameters, the bivariate distribution describes the comprehensive distribution of ventilation and perfusion that underlies the distribution of the Va/Q ratio.

Estimation of Lung Ventilation

Science.gov (United States)

Ding, Kai; Cao, Kunlin; Du, Kaifang; Amelon, Ryan; Christensen, Gary E.; Raghavan, Madhavan; Reinhardt, Joseph M.

Since the primary function of the lung is gas exchange, ventilation can be interpreted as an index of lung function in addition to perfusion. Injury and disease processes can alter lung function on a global and/or a local level. MDCT can be used to acquire multiple static breath-hold CT images of the lung taken at different lung volumes, or with proper respiratory control, 4DCT images of the lung reconstructed at different respiratory phases. Image registration can be applied to this data to estimate a deformation field that transforms the lung from one volume configuration to the other. This deformation field can be analyzed to estimate local lung tissue expansion, calculate voxel-by-voxel intensity change, and make biomechanical measurements. The physiologic significance of the registration-based measures of respiratory function can be established by comparing to more conventional measurements, such as nuclear medicine or contrast wash-in/wash-out studies with CT or MR. An important emerging application of these methods is the detection of pulmonary function change in subjects undergoing radiation therapy (RT) for lung cancer. During RT, treatment is commonly limited to sub-therapeutic doses due to unintended toxicity to normal lung tissue. Measurement of pulmonary function may be useful as a planning tool during RT planning, may be useful for tracking the progression of toxicity to nearby normal tissue during RT, and can be used to evaluate the effectiveness of a treatment post-therapy. This chapter reviews the basic measures to estimate regional ventilation from image registration of CT images, the comparison of them to the existing golden standard and the application in radiation therapy.

Prevention of reperfusion lung injury by lidocaine in isolated rat lung ventilated with higher oxygen levels.

Directory of Open Access Journals (Sweden)

Das K

2003-01-01

Full Text Available BACKGROUND: Lidocaine, an antiarrhythmic drug has been shown to be effective against post-ischaemic reperfusion injury in heart. However, its effect on pulmonary reperfusion injury has not been investigated. AIMS: We investigated the effects of lidocaine on a postischaemic reperfused rat lung model. MATERIALS AND METHODS: Lungs were isolated and perfused at constant flow with Krebs-Henseilet buffer containing 4% bovine serum albumin, and ventilated with 95% oxygen mixed with 5% CO2. Lungs were subjected to ischaemia by stopping perfusion for 60 minutes followed by reperfusion for 10 minutes. Ischaemia was induced in normothermic conditions. RESULTS: Postischaemic reperfusion caused significant (p < 0.0001 higher wet-to-dry lung weight ratio, pulmonary arterial pressure and peak airway pressure compared to control lungs. Lidocaine, at a dose of 5mg/Kg b.w. was found to significantly (p < 0.0001 attenuate the increase in the wet-to-dry lung weight ratio, pulmonary arterial pressure and peak airway pressure observed in post-ischaemic lungs. CONCLUSION: Lidocaine is effective in preventing post-ischaemic reperfusion injury in isolated, perfused rat lung.

MRI methods for pulmonary ventilation and perfusion imaging; Methoden der MRT zur Ventilations- und Perfusionsbildgebung der Lunge

Energy Technology Data Exchange (ETDEWEB)

Sommer, G. [Universitaetsspital Basel, Klinik fuer Radiologie und Nuklearmedizin, Basel (Switzerland); Bauman, G. [Universitaetsspital Basel, Klinik fuer Radiologie und Nuklearmedizin - Radiologische Physik, Basel (Switzerland)

2016-02-15

Separate assessment of respiratory mechanics, gas exchange and pulmonary circulation is essential for the diagnosis and therapy of pulmonary diseases. Due to the global character of the information obtained clinical lung function tests are often not sufficiently specific in the differential diagnosis or have a limited sensitivity in the detection of early pathological changes. The standard procedures of pulmonary imaging are computed tomography (CT) for depiction of the morphology as well as perfusion/ventilation scintigraphy and single photon emission computed tomography (SPECT) for functional assessment. Magnetic resonance imaging (MRI) with hyperpolarized gases, O{sub 2}-enhanced MRI, MRI with fluorinated gases and Fourier decomposition MRI (FD-MRI) are available for assessment of pulmonary ventilation. For assessment of pulmonary perfusion dynamic contrast-enhanced MRI (DCE-MRI), arterial spin labeling (ASL) and FD-MRI can be used. Imaging provides a more precise insight into the pathophysiology of pulmonary function on a regional level. The advantages of MRI are a lack of ionizing radiation, which allows a protective acquisition of dynamic data as well as the high number of available contrasts and therefore accessible lung function parameters. Sufficient clinical data exist only for certain applications of DCE-MRI. For the other techniques, only feasibility studies and case series of different sizes are available. The clinical applicability of hyperpolarized gases is limited for technical reasons. The clinical application of the techniques described, except for DCE-MRI, should be restricted to scientific studies. (orig.) [German] Die separate Beurteilung von Atemmechanik, Gasaustauschprozessen und Lungenzirkulation ist wesentlich fuer die Diagnose und Therapie von Lungenerkrankungen. Klinische Lungenfunktionstests sind aufgrund ihrer zumeist nur globalen Aussage oft nicht hinreichend spezifisch in der Differenzialdiagnostik oder eingeschraenkt sensitiv bei der

Pulmonary embolism: Prospective comparison of spiral CT with ventilation - perfusion scintigraphy

International Nuclear Information System (INIS)

Mayo Jhon R; Remi Jardin, Martine; Muller Mestor I

1999-01-01

The pulmonary thromboembolism (PTE) it is an entity common with great morbidity and mortality that it requires a diagnosis soon and specify. Commonly the ventilation gammagraphy - perfusion has been the used exam of first more frequent line when one suspects the PTE but unfortunately a great quantity of reports is called of intermediate probability, for what requires complementary studies, to confirm or to discard the diagnosis. A prospective study was made with 142 patients that had suspicion of TEP in the hospital of Vancouver (Canada) and in the hospital of Calmette (France), being carried out in all gammagraphy of ventilation-perfusion and helical CT, being only taken to lung angiography to those that not had high clinical suspicion of TEP with gammagraphy or helical CT very suggestive or tuneless, undergoing the results valuation for different observers

[MRI methods for pulmonary ventilation and perfusion imaging].

Science.gov (United States)

Sommer, G; Bauman, G

2016-02-01

Separate assessment of respiratory mechanics, gas exchange and pulmonary circulation is essential for the diagnosis and therapy of pulmonary diseases. Due to the global character of the information obtained clinical lung function tests are often not sufficiently specific in the differential diagnosis or have a limited sensitivity in the detection of early pathological changes. The standard procedures of pulmonary imaging are computed tomography (CT) for depiction of the morphology as well as perfusion/ventilation scintigraphy and single photon emission computed tomography (SPECT) for functional assessment. Magnetic resonance imaging (MRI) with hyperpolarized gases, O2-enhanced MRI, MRI with fluorinated gases and Fourier decomposition MRI (FD-MRI) are available for assessment of pulmonary ventilation. For assessment of pulmonary perfusion dynamic contrast-enhanced MRI (DCE-MRI), arterial spin labeling (ASL) and FD-MRI can be used. Imaging provides a more precise insight into the pathophysiology of pulmonary function on a regional level. The advantages of MRI are a lack of ionizing radiation, which allows a protective acquisition of dynamic data as well as the high number of available contrasts and therefore accessible lung function parameters. Sufficient clinical data exist only for certain applications of DCE-MRI. For the other techniques, only feasibility studies and case series of different sizes are available. The clinical applicability of hyperpolarized gases is limited for technical reasons. The clinical application of the techniques described, except for DCE-MRI, should be restricted to scientific studies.

MRI methods for pulmonary ventilation and perfusion imaging

International Nuclear Information System (INIS)

Sommer, G.; Bauman, G.

2016-01-01

Separate assessment of respiratory mechanics, gas exchange and pulmonary circulation is essential for the diagnosis and therapy of pulmonary diseases. Due to the global character of the information obtained clinical lung function tests are often not sufficiently specific in the differential diagnosis or have a limited sensitivity in the detection of early pathological changes. The standard procedures of pulmonary imaging are computed tomography (CT) for depiction of the morphology as well as perfusion/ventilation scintigraphy and single photon emission computed tomography (SPECT) for functional assessment. Magnetic resonance imaging (MRI) with hyperpolarized gases, O 2 -enhanced MRI, MRI with fluorinated gases and Fourier decomposition MRI (FD-MRI) are available for assessment of pulmonary ventilation. For assessment of pulmonary perfusion dynamic contrast-enhanced MRI (DCE-MRI), arterial spin labeling (ASL) and FD-MRI can be used. Imaging provides a more precise insight into the pathophysiology of pulmonary function on a regional level. The advantages of MRI are a lack of ionizing radiation, which allows a protective acquisition of dynamic data as well as the high number of available contrasts and therefore accessible lung function parameters. Sufficient clinical data exist only for certain applications of DCE-MRI. For the other techniques, only feasibility studies and case series of different sizes are available. The clinical applicability of hyperpolarized gases is limited for technical reasons. The clinical application of the techniques described, except for DCE-MRI, should be restricted to scientific studies. (orig.) [de

Clinical studies on combined ventilation (sup(81m)Kr)/perfusion (sup(99m)Tc-MAA) scintigraphy

International Nuclear Information System (INIS)

Yamamoto, Keiichiro; Miyamae, Tatsuya

1983-01-01

One hundred fifty patients having pulmonary disease underwent pulmonary scintigraphy sequentially with sup(99m)Tc-MAA and sup(81m)Kr gases. Scintigrams of matched defect were obtained from 113 (75.3%) of the 150 patients, considered to be nonspecific universal pattern of a pulmonary disease. Scintigrams of mismatched defect (absent perfusion and homogeneous ventilation) were obtained from 20 patients (13.3%), including 6 with lung carcinoma, 3 with pulmonary embolism, 3 with connective tissue disease, 2 with aortitis syndrome and 6 with other diseases. Scintigrams of mismatch with impaired ventilation and normal perfusion were mainly seen in chronic obstructive lung diseases. Of the 10 patients with bronchial asthma, 5 had scintigrams of improved ventilation after intravenous injection of 250 mg aminophilline, but none of patients with emphysema. The combined scintigraphy has made significant contributions to diagnosis and management of patients with pulmonary disease where the chest X-ray is unhelpful. (author)

Emergency perfusion lung scan of pulmonary embolism

International Nuclear Information System (INIS)

Ueno, Kyoichi; Kabuto, Hiroko; Rikimaru, Shigeho

1984-01-01

Pulmonary embolism (PE) has been reported to be quite rare in Japan, and there have been few clinical studies on the nuclear diagnosis of PE with the exception of several case reports. However, we have experienced 12 acute PE, and 2 chronic PE in 5 years 2 months. In 33 emergency cases who were highly suspected to have PE, we could diagnose 12 cases of PE, and 19 cases of non-PE. However, the remaining 2 cases were equivocal because of underlying chronic lung disease. Using Kr-81m ventilation lung scan, V/Q mismatch was found in all of 10 cases. Usefulness of emergency perfusion lung scan in Japan should be stressed. (author)

Kinetics of reversible-sequestration of leukocytes by the isolated perfused rat lung

Energy Technology Data Exchange (ETDEWEB)

Goliaei, B.

1980-08-01

The kinetics and morphology of sequestration and margination of rat leukocytes were studied using an isolated perfused and ventilated rat lung preparation. Whole rat blood, bone marrow suspension, or leukocyte suspensions, were used to perfuse the isolated rat lung. The lung was also perfused with latex particle suspensions and the passage of particles through the lung capillaries was studied. When a leukocyte suspension was perfused through the lung in the single-pass mode, the rate of sequestration decreased as more cells were perfused. In contrast, latex particles of a size comparable to that of leukocytes were totally stopped by the lung. When the leukocyte suspension was recirculated through the lung, cells were rapidly removed from circulation until a steady state was reached, after which no net removal of cells by the lung occurred. These results indicate that leukocytes are reversibly sequestered from circulation. The sequestered cells marginated and attached to the luminal surface of the endothelium of post-capillary venules and veins. A mathematical model was developed based on the assumption that the attachment and detachment of leukocytes to blood vessel walls follows first-order kinetics. The model correctly predicts the following characteristics of the system: (a) the kinetics of the sequestration of leukocytes by the lung; (b) the existence of a steady state when a suspension of leukocytes is recirculated through the lung; and (c) the independence of the fraction of cells remaining in circulation from the starting concentration for all values of starting concentration. (ERB)

Regional distribution of ventilation-perfusion ratio in patients with interstitial pneumonia using Kr-81m

International Nuclear Information System (INIS)

Sekine, Hiroshi; Kawakami, Kenji; Shimada, Takao

1983-01-01

In order to know the pathophysiological change of interstitial pneumonia, it is important to detect the morphological change of vascular and air way systems in the lung. The study group consisted of 12 patients of interstitial pneumonia including IIP, PSS, RA, sarcoidosis, and hypersensitive pneumonia. The Kr-81m bolus inhalation from 3 different lung volumes were analyzed to detect regional ventilation abnormalities. The regional distribution of ventilation-perfusion ratio (V/Q) in the lung was obtained from the continuous inhalation and infusion Kr-81 m. In 7 patients, regional distribution of V/Q was also measured at rest and during exercise. In advanced stage of interstitial pneumonia, radioactivity in lower lung fields was decreased in bolus inhalation from TLC-400 ml lung volume, and present in lower lung in bolus inhalation from RV level. These findings are representing air way rigidity especially in lower lung fields. However, in early stage or reversible cases, it is difficult to detect the abnormal distribution of radioactivity in lung, in spite of decreased PO 2 . So it seems impossible to screen early stage or reversible cases of interstitial pneumonia by bolus inhalation method alone. At rest for normal subjects in the upright position, the apical zone had a high V/Q, but in the lower parts two third of V/Q distribution was relatively homogeneous. During exercise at 50W, the distribution became more uniform. In most cases of the disease, weak exercise (less than 40W) produced the same uniform V/Q distribution. It should be noted that in the disease not only was perfusion in upper lung fields increased, but that perfusion of lower lung fields was reduced. So late in the cource of extension of the disease, pulmonary vascular bed in the lower lung fields is restricted.(J.P.N.)

Low pulmonary artery flush perfusion pressure combined with high positive end-expiratory pressure reduces oedema formation in isolated porcine lungs

International Nuclear Information System (INIS)

Schumann, Stefan; Schließmann, Stephan J; Wagner, Giskard; Goebel, Ulrich; Priebe, Hans-Joachim; Guttmann, Josef; Kirschbaum, Andreas

2010-01-01

Flush perfusion of the pulmonary artery with organ protection solution is a standard procedure before lung explantation. However, rapid flush perfusion may cause pulmonary oedema which is deleterious in the lung transplantation setting. In this study we tested the hypotheses that high pulmonary perfusion pressure contributes to the development of pulmonary oedema and positive end-expiratory pressure (PEEP) counteracts oedema formation. We expected oedema formation to increase weight and decrease compliance of the lungs on the basis of a decrease in alveolar volume as fluid replaces alveolar air spaces. The pulmonary artery of 28 isolated porcine lungs was perfused with a low-potassium dextrane solution at low (mean 27 mmHg) or high (mean 40 mmHg) pulmonary artery pressure (PAP) during mechanical ventilation at low (4 cmH 2 O) or high (8 cmH 2 O) PEEP, respectively. Following perfusion and storage, relative increases in lung weight were smaller (p < 0.05) during perfusion at low PAP (62 ± 32% and 42 ± 26%, respectively) compared to perfusion at high PAP (133 ± 54% and 87 ± 30%, respectively). Compared to all other PAP–PEEP combinations, increases in lung weight were smallest (44 ± 9% and 27 ± 12%, respectively), nonlinear intratidal lung compliance was largest (46% and 17% respectively, both p < 0.05) and lung histology showed least infiltration of mononuclear cells in the alveolar septa, and least alveolar destruction during the combination of low perfusion pressure and high PEEP. The findings suggest that oedema formation during pulmonary artery flush perfusion in isolated and ventilated lungs can be reduced by choosing low perfusion pressure and high PEEP. PAP–PEEP titration to minimize pulmonary oedema should be based on lung mechanics and PAP monitoring

Ventilation/perfusion SPECT or SPECT/CT for lung function imaging in patients with pulmonary emphysema?

Science.gov (United States)

Froeling, Vera; Heimann, Uwe; Huebner, Ralf-Harto; Kroencke, Thomas J; Maurer, Martin H; Doellinger, Felix; Geisel, Dominik; Hamm, Bernd; Brenner, Winfried; Schreiter, Nils F

2015-07-01

To evaluate the utility of attenuation correction (AC) of V/P SPECT images for patients with pulmonary emphysema. Twenty-one patients (mean age 67.6 years) with pulmonary emphysema who underwent V/P SPECT/CT were included. AC/non-AC V/P SPECT images were compared visually and semiquantitatively. Visual comparison of AC/non-AC images was based on a 5-point likert scale. Semiquantitative comparison assessed absolute counts per lung (aCpLu) and lung lobe (aCpLo) for AC/non-AC images using software-based analysis; percentage counts (PC = (aCpLo/aCpLu) × 100) were calculated. Correlation between AC/non-AC V/P SPECT images was analyzed using Spearman's rho correlation coefficient; differences were tested for significance with the Wilcoxon rank sum test. Visual analysis revealed high conformity for AC and non-AC V/P SPECT images. Semiquantitative analysis of PC in AC/non-AC images had an excellent correlation and showed no significant differences in perfusion (ρ = 0.986) or ventilation (ρ = 0.979, p = 0.809) SPECT/CT images. AC of V/P SPECT images for lung lobe-based function imaging in patients with pulmonary emphysema do not improve visual or semiquantitative image analysis.

Lung ventilation-perfusion imbalance in pulmonary emphysema. Assessment with automated V/Q quotient SPECT

International Nuclear Information System (INIS)

Suga, Kazuyoshi; Kawakami, Yasuhiko; Koike, Hiroaki; Iwanaga, Hideyuki; Tokuda, Osamu; Okada, Munemasa; Matsunaga, Naofumi

2010-01-01

Tc-99m-Technegas-macro-aggregated albumin (MAA) single photon emission computed tomography (SPECT)-derived ventilation (V)/perfusion (Q) quotient SPECT was used to assess lung V-Q imbalance in patients with pulmonary emphysema. V/Q quotient SPECT and V/Q profile were automatically built in 38 patients with pulmonary emphysema and 12 controls, and V/Q distribution and V/Q profile parameters were compared. V/Q distribution on V/Q quotient SPECT was correlated with low attenuation areas (LAA) on density-mask computed tomography (CT). Parameters of V/Q profile such as the median, standard deviation (SD), kurtosis and skewness were proposed to objectively evaluate the severity of lung V-Q imbalance. In contrast to uniform V/Q distribution on V/Q quotient SPECT and a sharp peak with symmetrical V/Q distribution on V/Q profile in controls, lung areas showing heterogeneously high or low V/Q and flattened peaks with broadened V/Q distribution were frequently seen in patients with emphysema, including lung areas with only slight LAA. V/Q distribution was also often asymmetric regardless of symmetric LAA. All the proposed parameters of V/Q profile in entire lungs of patients with emphysema showed large variations compared with controls; SD and kurtosis were significantly different from controls (P<0.0001 and P<0.001, respectively), and a significant correlation was found between SD and A-aDO2 (P<0.0001). V/Q quotient SPECT appears to be more sensitive to detect emphysematous lungs compared with morphologic CT in patients with emphysema. SD and kurtosis of V/Q profile can be adequate parameters to assess the severity of lung V-Q imbalance causing gas-exchange impairment in patients with emphysema. (author)

Alternating versus synchronous ventilation of left and right lungs in piglets

NARCIS (Netherlands)

A. Versprille (Adrian); V. Hrachovina (V.); J.R.C. Jansen (Jos)

1995-01-01

textabstractObjective: We tested whether alternating ventilation (AV) of each lung (i.e. with a phase difference of half a ventilatory cycle) would decrease central venous pressure and so increase cardiac output when compared with simultaneous ventilation (SV) of both lungs. Theory: If, during AV,

Detection of pulmonary embolism with combined ventilation-perfusion SPECT and low-dose CT: head-to-head comparison with multidetector CT angiography

DEFF Research Database (Denmark)

Gutte, Henrik; Mortensen, Jann; Jensen, Claus Verner

2009-01-01

The diagnosis of pulmonary embolism (PE) is usually established by a combination of clinical assessment, D-dimer testing, and imaging with either pulmonary ventilation-perfusion (V/Q) scintigraphy or pulmonary multidetector CT (MDCT) angiography. Both V/Q SPECT and MDCT angiography seem to have...... high diagnostic accuracy. However, only limited data directly comparing these 2 modalities are available. Hybrid gamma-camera/MDCT systems have been introduced and allow simultaneous 3-dimensional lung V/Q SPECT and MDCT angiography, suitable for diagnosing PE. The aim of our study was to compare...

Successful 1:1 proportion ventilation with a unique device for independent lung ventilation using a double-lumen tube without complications in the supine and lateral decubitus positions. A pilot study.

Directory of Open Access Journals (Sweden)

Michał Kowalczyk

Full Text Available Adequate blood oxygenation and ventilation/perfusion matching should be main goal of anaesthetic and intensive care management. At present, one of the methods of improving gas exchange restricted by ventilation/perfusion mismatching is independent ventilation with two ventilators. Recently, however, a unique device has been developed, enabling ventilation of independent lungs in 1:1, 2:1, 3:1, and 5:1 proportions. The main goal of the study was to evaluate the device's utility, precision and impact on pulmonary mechanics. Secondly- to measure the gas distribution in supine and lateral decubitus position.69 patients who underwent elective thoracic surgery were eligible for the study. During general anaesthesia, after double lumen tube intubation, the aforementioned control system was placed between the anaesthetic machine and the patient. In the supine and lateral decubitus (left/right positions, measurements of conventional and independent (1:1 proportion ventilation were performed separately for each lung, including the following: tidal volume, peak pressure and dynamic compliance.Our results show that conventional ventilation using Robertshaw tube in the supine position directs 47% of the tidal volume to the left lung and 53% to the right lung. Furthermore, in the left lateral position, 44% is directed to the dependent lung and 56% to the non-dependent lung. In the right lateral position, 49% is directed to the dependent lung and 51% to the non-dependent lung. The control system positively affected non-dependent and dependent lung ventilation by delivering equal tidal volumes into both lungs with no adverse effects, regardless of patient's position.We report that gas distribution is uneven during conventional ventilation using Robertshaw tube in the supine and lateral decubitus positions. However, this recently released control system enables precise and safe independent ventilation in the supine and the left and right lateral decubitus

Physiologic Evaluation of Ventilation Perfusion Mismatch and Respiratory Mechanics at Different Positive End-expiratory Pressure in Patients Undergoing Protective One-lung Ventilation.

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Spadaro, Savino; Grasso, Salvatore; Karbing, Dan Stieper; Fogagnolo, Alberto; Contoli, Marco; Bollini, Giacomo; Ragazzi, Riccardo; Cinnella, Gilda; Verri, Marco; Cavallesco, Narciso Giorgio; Rees, Stephen Edward; Volta, Carlo Alberto

2018-03-01

Arterial oxygenation is often impaired during one-lung ventilation, due to both pulmonary shunt and atelectasis. The use of low tidal volume (VT) (5 ml/kg predicted body weight) in the context of a lung-protective approach exacerbates atelectasis. This study sought to determine the combined physiologic effects of positive end-expiratory pressure and low VT during one-lung ventilation. Data from 41 patients studied during general anesthesia for thoracic surgery were collected and analyzed. Shunt fraction, high V/Q and respiratory mechanics were measured at positive end-expiratory pressure 0 cm H2O during bilateral lung ventilation and one-lung ventilation and, subsequently, during one-lung ventilation at 5 or 10 cm H2O of positive end-expiratory pressure. Shunt fraction and high V/Q were measured using variation of inspired oxygen fraction and measurement of respiratory gas concentration and arterial blood gas. The level of positive end-expiratory pressure was applied in random order and maintained for 15 min before measurements. During one-lung ventilation, increasing positive end-expiratory pressure from 0 cm H2O to 5 cm H2O and 10 cm H2O resulted in a shunt fraction decrease of 5% (0 to 11) and 11% (5 to 16), respectively (P ventilation, high positive end-expiratory pressure levels improve pulmonary function without increasing high V/Q and reduce driving pressure.

Effects of ventilation strategy on distribution of lung inflammatory cell activity

Science.gov (United States)

2013-01-01

Introduction Leukocyte infiltration is central to the development of acute lung injury, but it is not known how mechanical ventilation strategy alters the distribution or activation of inflammatory cells. We explored how protective (vs. injurious) ventilation alters the magnitude and distribution of lung leukocyte activation following systemic endotoxin administration. Methods Anesthetized sheep received intravenous endotoxin (10 ng/kg/min) followed by 2 h of either injurious or protective mechanical ventilation (n = 6 per group). We used positron emission tomography to obtain images of regional perfusion and shunting with infused 13N[nitrogen]-saline and images of neutrophilic inflammation with 18F-fluorodeoxyglucose (18F-FDG). The Sokoloff model was used to quantify 18F-FDG uptake (Ki), as well as its components: the phosphorylation rate (k3, a surrogate of hexokinase activity) and the distribution volume of 18F-FDG (Fe) as a fraction of lung volume (Ki = Fe × k3). Regional gas fractions (fgas) were assessed by examining transmission scans. Results Before endotoxin administration, protective (vs. injurious) ventilation was associated with a higher ratio of partial pressure of oxygen in arterial blood to fraction of inspired oxygen (PaO2/FiO2) (351 ± 117 vs. 255 ± 74 mmHg; P ventilation, which also increased the shunt fraction in dependent lung. Protective ventilation resulted in less nonaerated lung (20-fold; P protective (vs. injurious) ventilation, especially in dependent lung regions (0.0075 ± 0.0043/min vs. 0.0157 ± 0.0072/min; P ventilation and accounted for most of the between-group difference in Ki. Dependent regions of the protective ventilation group exhibited lower k3 values per neutrophil than those in the injurious ventilation group (P = 0.01). In contrast, Fe was not affected by ventilation strategy (P = 0.52). Lung neutrophil counts were not different between groups, even when regional inflation was accounted for. Conclusions During systemic

Pulmonary ventilation/perfusion scan

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... to stop eating (fast), be on a special diet, or take any medicines before the test. A chest x-ray is usually done before or after a ventilation and perfusion scan. You wear a hospital gown or comfortable clothing that does not have ...

Dual energy CT for the assessment of lung perfusion-Correlation to scintigraphy

International Nuclear Information System (INIS)

Thieme, Sven F.; Becker, Christoph R.; Hacker, Marcus; Nikolaou, Konstantin; Reiser, Maximilian F.; Johnson, Thorsten R.C.

2008-01-01

Purpose of this study was to determine the diagnostic value of dual energy CT in the assessment of pulmonary perfusion with reference to pulmonary perfusion scintigraphy. Thirteen patients received both dual energy CT (DECT) angiography (Somatom Definition, Siemens) and ventilation/perfusion scintigraphy. Median time between scans was 3 days (range, 0-90). DECT perfusion maps were generated based on the spectral properties of iodine. Two blinded observes assessed DECT angiograms, perfusion maps and scintigrams for presence and location of perfusion defects. The results were compared by patient and by segment, and diagnostic accuracy of DECT perfusion imaging was calculated regarding scintigraphy as standard of reference. Diagnostic accuracy per patient showed 75% sensitivity, 80% specificity and a negative predictive value of 66%. Sensitivity per segment amounted to 83% with 99% specificity, with 93% negative predictive value. Peripheral parts of the lungs were not completely covered by the 80 kVp detector in 85% of patients. CTA identified corresponding emboli in 66% of patients with concordant perfusion defects in DECT and scintigraphy. Dual energy CT perfusion imaging is able to display pulmonary perfusion defects with good agreement to scintigraphic findings. DECT can provide a pulmonary CT angiogram, high-resolution morphology of the lung parenchyma and perfusion information in one single exam

Dual energy CT for the assessment of lung perfusion-Correlation to scintigraphy

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Thieme, Sven F.; Becker, Christoph R. [Department of Clinical Radiology, Ludwig-Maximilians-University of Munich (Germany); Hacker, Marcus [Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich (Germany); Nikolaou, Konstantin; Reiser, Maximilian F. [Department of Clinical Radiology, Ludwig-Maximilians-University of Munich (Germany); Johnson, Thorsten R.C. [Department of Clinical Radiology, Ludwig-Maximilians-University of Munich (Germany)], E-mail: thorsten.johnson@med.uni-muenchen.de

2008-12-15

Purpose of this study was to determine the diagnostic value of dual energy CT in the assessment of pulmonary perfusion with reference to pulmonary perfusion scintigraphy. Thirteen patients received both dual energy CT (DECT) angiography (Somatom Definition, Siemens) and ventilation/perfusion scintigraphy. Median time between scans was 3 days (range, 0-90). DECT perfusion maps were generated based on the spectral properties of iodine. Two blinded observes assessed DECT angiograms, perfusion maps and scintigrams for presence and location of perfusion defects. The results were compared by patient and by segment, and diagnostic accuracy of DECT perfusion imaging was calculated regarding scintigraphy as standard of reference. Diagnostic accuracy per patient showed 75% sensitivity, 80% specificity and a negative predictive value of 66%. Sensitivity per segment amounted to 83% with 99% specificity, with 93% negative predictive value. Peripheral parts of the lungs were not completely covered by the 80 kVp detector in 85% of patients. CTA identified corresponding emboli in 66% of patients with concordant perfusion defects in DECT and scintigraphy. Dual energy CT perfusion imaging is able to display pulmonary perfusion defects with good agreement to scintigraphic findings. DECT can provide a pulmonary CT angiogram, high-resolution morphology of the lung parenchyma and perfusion information in one single exam.

Comparison of lung preservation solutions in human lungs using an ex vivo lung perfusion experimental model

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Israel L. Medeiros

2012-09-01

Full Text Available OBJECTIVE: Experimental studies on lung preservation have always been performed using animal models. We present ex vivo lung perfusion as a new model for the study of lung preservation. Using human lungs instead of animal models may bring the results of experimental studies closer to what could be expected in clinical practice. METHOD: Brain-dead donors whose lungs had been declined by transplantation teams were used. The cases were randomized into two groups. In Group 1, Perfadex®was used for pulmonary preservation, and in Group 2, LPDnac, a solution manufactured in Brazil, was used. An ex vivo lung perfusion system was used, and the lungs were ventilated and perfused after 10 hours of cold ischemia. The extent of ischemic-reperfusion injury was measured using functional and histological parameters. RESULTS: After reperfusion, the mean oxygenation capacity was 405.3 mmHg in Group 1 and 406.0 mmHg in Group 2 (p = 0.98. The mean pulmonary vascular resistance values were 697.6 and 378.3 dyn·s·cm-5, respectively (p =0.035. The mean pulmonary compliance was 46.8 cm H20 in Group 1 and 49.3 ml/cm H20 in Group 2 (p =0.816. The mean wet/dry weight ratios were 2.06 and 2.02, respectively (p=0.87. The mean Lung Injury Scores for the biopsy performed after reperfusion were 4.37 and 4.37 in Groups 1 and 2, respectively (p = 1.0, and the apoptotic cell counts were 118.75/mm² and 137.50/mm², respectively (p=0.71. CONCLUSION: The locally produced preservation solution proved to be as good as Perfadex®. The clinical use of LPDnac may reduce costs in our centers. Therefore, it is important to develop new models to study lung preservation.

Pulmonary ventilation and perfusion scintigraphy in patients with bronchial asthma

International Nuclear Information System (INIS)

Ono, Seiji; Hoshi, Hiroaki; Watanabe, Katsushi.

1988-01-01

Pulmonary ventilation and perfusion scan using Xe-133 gas and Tc-99m MAA were performed in 18 patients with bronchial asthma to evaluate the regional pulmonary function. The scintigraphic findings were compared with the results of the auscultation and the conventional pulmonary functioning examination (%FVC, %FEV 1.0 ). Ventilation image showed abnormality in 12 (70.6%) out of the asymptomatic 17 patients and perfusion image showed abnormality in 7 (41.2%) out of 17 patients. These 7 patients with abnormality on perfusion image all showed abnormality on ventilation image. The grade of abnormality in scintigraphic findings was compatible with the values of %FVC and %FEV 1.0 . In conclusion Xe-133 ventilation and Tc-99m MAA perfusion scan were useful procedures to estimate the pulmonary function of patients with bronchial asthma. (author)

99mTc-DTPA aerosol for same-day post-perfusion ventilation imaging: Results of a multicentre study

International Nuclear Information System (INIS)

Koehn, H.; Koenig, B.; Bachmayr, S.; Markt, B.; Eber, O.; Lind, P.; Galvan, G.; Rettenbacher, L.; Holm, C.; Ogris, E.

1993-01-01

A multicentre study was performed in an attempt to evaluate a submicronic technetium-99m diethylene triamine penta-acetic acid aerosol generated by a newly developed delivery system, the aerosol production equipment (APE nebulizer), for same-day post-perfusion ventilation imaging in patients with clinically suspected pulmonary embolism. Quantitative comparison between the DTPA aerosol and krypton gas demonstrated a close correlation with respect to regional pulmonary distribution of activity and peripheral lung penetration (n=14, r=0.94, P 99m Tc-labelled DTPA aerosol is well suited for fast same-day post-perfusion ventilation imaging in patients with clinical suspicion of pulmonary embolism. (orig.)

Prediction of postoperative lung function after pulmonary resection

International Nuclear Information System (INIS)

Yoshikawa, Koichi

1988-01-01

Lung scintigraphy and ordinary lung function test as well as split lung function test by using bronchospirometry was performed in 78 patients with primary lung cancer and clinical significance of ventilation and perfusion scintigraphy was evaluated. Results obtained from this study are as follows. 1) The ratio of right VC to total VC obtained by preoperative bronchospirometry was well correlated to the ratio of right lung count to the total lung count obtained by ventiration and/or perfusion scintigraphy (r = 0.84, r = 0.69). 2) Evaluation of the data obtained from the patients undergoing pneumonectomy indicated that the right and left VC obtained preoperatively by bronchospirometry have their clinical significance only in the form of left to right ratio not in the form their absolure value. 3) As to the reliability of predicting the residual vital capacity after pneumonectomy on the basis of left-to-right of lung scintigraphy, ventilation scintigraphy is more reliable than perfusion scintigraphy. 4) Irrespective of using ventilation scintigraphy or perfusion scintigraphy, Ali's formular showed high reliability in predicting the residual vital capacity as well as FEV 1.0 after lobectomy. 5) Reduction of the perfusion rate in the operated side of the lung is more marked than of the ventilation rate, resulting in a significant elevation of ventilation/perfusion ratio of the operated side of the lung. From the results descrived above, it can be said that lung ventilation and perfusion scintigraphy are very useful method to predict the residual lung function as well as the change of ventilation/perfusion ratio after pulmonary resection. (author)

Regional distribution of ventilation and perfusion in patients with obstructive pulmonary disease and alpha/sub 1/-antitrypsin deficiency

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Mostafa, A B.M.G.; Tulley, N J; Harding, L K; Stockley, R A

1983-08-01

Regional distribution of pulmonary ventilation and perfusion has been determined of 13 patients with chronic obstructive pulmonary disease (COPD). Eight patients had alpha/sub 1/-antitrypsin deficiency (..cap alpha../sub 1/ATD). Ventilation studies were carried out using xenon-133 (/sup 133/Xe) and krypton-81m (sup(81m)Kr) gases. Trapping indices were determined from the wash-out part of the xenon ventilation studies. Results obtained from patients were compared with those of normal controls. Ventilation studies with sup(81m)Kr showed pulmonary changes more clearly than did /sup 133/Xe studies and the trapping of radio-xenon was more extensive in lung bases than in apices whether or not the patients had ..cap alpha../sub 1/ ATD. The distribution of perfusion followed a pattern similar to that of ventilation, but did not differ statistically from that of the normal controls.

Open lung approach vs acute respiratory distress syndrome network ventilation in experimental acute lung injury.

Science.gov (United States)

Spieth, P M; Güldner, A; Carvalho, A R; Kasper, M; Pelosi, P; Uhlig, S; Koch, T; Gama de Abreu, M

2011-09-01

Setting and strategies of mechanical ventilation with positive end-expiratory pressure (PEEP) in acute lung injury (ALI) remains controversial. This study compares the effects between lung-protective mechanical ventilation according to the Acute Respiratory Distress Syndrome Network recommendations (ARDSnet) and the open lung approach (OLA) on pulmonary function and inflammatory response. Eighteen juvenile pigs were anaesthetized, mechanically ventilated, and instrumented. ALI was induced by surfactant washout. Animals were randomly assigned to mechanical ventilation according to the ARDSnet protocol or the OLA (n=9 per group). Gas exchange, haemodynamics, pulmonary blood flow (PBF) distribution, and respiratory mechanics were measured at intervals and the lungs were removed after 6 h of mechanical ventilation for further analysis. PEEP and mean airway pressure were higher in the OLA than in the ARDSnet group [15 cmH(2)O, range 14-18 cmH(2)O, compared with 12 cmH(2)O; 20.5 (sd 2.3) compared with 18 (1.4) cmH(2)O by the end of the experiment, respectively], and OLA was associated with improved oxygenation compared with the ARDSnet group after 6 h. OLA showed more alveolar overdistension, especially in gravitationally non-dependent regions, while the ARDSnet group was associated with more intra-alveolar haemorrhage. Inflammatory mediators and markers of lung parenchymal stress did not differ significantly between groups. The PBF shifted from ventral to dorsal during OLA compared with ARDSnet protocol [-0.02 (-0.09 to -0.01) compared with -0.08 (-0.12 to -0.06), dorsal-ventral gradients after 6 h, respectively]. According to the OLA, mechanical ventilation improved oxygenation and redistributed pulmonary perfusion when compared with the ARDSnet protocol, without differences in lung inflammatory response.

Regional measurement of ventilation and perfusion to detect subtle lung abnormalities in coal miners

International Nuclear Information System (INIS)

Susskind, H.; Liu, J.; Brill, A.B.

1986-01-01

The relationship between regional pulmonary ventilation (V) and perfusion (Q) uniquely determines the amount of gas exchange that occurs in the lungs. Therefore, the pixel-by-pixel distributions of V and Q were measured with continuously inhaled Kr-81m and i.v. injected Tc-99m MAA, respectively, in a group of 71 subjects exposed to coal dust and then compared with those from a control group of 9 healthy volunteers. Each subject sat upright with his back against a large-field-of-view scintillation camera; 500,000 count images were obtained, analyzed by computer, and then displayed in a 64 x 64 matrix. Individual pixel values of V and Q were correlated by a best-fit regression line, whose slope was proportional to the overall V/Q ratio. The slopes of individual groups of nonsmokers, ex-smokers, and smokers (0.83-0.85) were significantly greater (p < 0.02) than the slope of the controls (0.70 +/- 0.07). In addition, the authors found that the skewness of plots of frequency distribution of V/Q and of V and Q vs V/Q for the individual patient groups was statistically different from that of the normals (p < 0.01). Statistical analysis of local and Q values therefore appears to be a potentially useful, non-invasive method to evaluate subtle regional lung impairment

Partial liquid ventilation improves lung function in ventilation-induced lung injury

NARCIS (Netherlands)

G.F. Vazquez de Anda; R.A. Lachmann; S.J.C. Verbrugge (Serge); D.A.M.P.J. Gommers (Diederik); J.J. Haitsma (Jack); B.F. Lachmann (Burkhard)

2001-01-01

textabstractDisturbances in lung function and lung mechanics are present after ventilation with high peak inspiratory pressures (PIP) and low levels of positive end-expiratory pressure (PEEP). Therefore, the authors investigated whether partial liquid ventilation can re-establish

Effect of Electrode Belt and Body Positions on Regional Pulmonary Ventilation- and Perfusion-Related Impedance Changes Measured by Electric Impedance Tomography.

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Elin Ericsson

Full Text Available Ventilator-induced or ventilator-associated lung injury (VILI/VALI is common and there is an increasing demand for a tool that can optimize ventilator settings. Electrical impedance tomography (EIT can detect changes in impedance caused by pulmonary ventilation and perfusion, but the effect of changes in the position of the body and in the placing of the electrode belt on the impedance signal have not to our knowledge been thoroughly evaluated. We therefore studied ventilation-related and perfusion-related changes in impedance during spontaneous breathing in 10 healthy subjects in five different body positions and with the electrode belt placed at three different thoracic positions using a 32-electrode EIT system. We found differences between regions of interest that could be attributed to changes in the position of the body, and differences in impedance amplitudes when the position of the electrode belt was changed. Ventilation-related changes in impedance could therefore be related to changes in the position of both the body and the electrode belt. Perfusion-related changes in impedance were probably related to the interference of major vessels. While these findings give us some insight into the sources of variation in impedance signals as a result of changes in the positions of both the body and the electrode belt, further studies on the origin of the perfusion-related impedance signal are needed to improve EIT further as a tool for the monitoring of pulmonary ventilation and perfusion.

Initial mechanical ventilator settings and lung protective ventilation in the ED.

Science.gov (United States)

Wilcox, Susan R; Richards, Jeremy B; Fisher, Daniel F; Sankoff, Jeffrey; Seigel, Todd A

2016-08-01

Mechanical ventilation with low tidal volumes has been shown to improve outcomes for patients both with and without acute respiratory distress syndrome. This study aims to characterize mechanically ventilated patients in the emergency department (ED), describe the initial ED ventilator settings, and assess for associations between lung protective ventilation strategies in the ED and outcomes. This was a multicenter, prospective, observational study of mechanical ventilation at 3 academic EDs. We defined lung protective ventilation as a tidal volume of less than or equal to 8 mL/kg of predicted body weight and compared outcomes for patients ventilated with lung protective vs non-lung protective ventilation, including inhospital mortality, ventilator days, intensive care unit length of stay, and hospital length of stay. Data from 433 patients were analyzed. Altered mental status without respiratory pathology was the most common reason for intubation, followed by trauma and respiratory failure. Two hundred sixty-one patients (60.3%) received lung protective ventilation, but most patients were ventilated with a low positive end-expiratory pressure, high fraction of inspired oxygen strategy. Patients were ventilated in the ED for a mean of 5 hours and 7 minutes but had few ventilator adjustments. Outcomes were not significantly different between patients receiving lung protective vs non-lung protective ventilation. Nearly 40% of ED patients were ventilated with non-lung protective ventilation as well as with low positive end-expiratory pressure and high fraction of inspired oxygen. Despite a mean ED ventilation time of more than 5 hours, few patients had adjustments made to their ventilators. Copyright © 2016 Elsevier Inc. All rights reserved.

Kombineret ventilations/perfusions-SPECT/CT er bedst til diagnostik af lungeemboli

DEFF Research Database (Denmark)

Gutte Borgwardt, Henrik; Mortensen, Jann; Kristoffersen, Ulrik Sloth

2012-01-01

The diagnosis of pulmonary embolism (PE) is usually established by a combination of clinical assessment, D-dimer test and imaging with either lung scintigraphy or pulmonary multidetector computed tomography angiography (CTA). Which of the two methods to use in PE diagnostic has not been determined...... and very limited data comparing these modalities are available. With the use of hybrid scanners, ventilation/perfusion-single-photon-emission-tomography (V/Q-SPECT) in combination with low-dose CT without contrast enhancement is feasible and should probably be considered first-line imaging in diagnosing PE....

Pulmonary ventilation/perfusion single photon emission tomography – Initial experience of a Nuclear Medicine Department

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J. G. Santos

2016-01-01

Full Text Available Introduction: Lung ventilation/perfusion scintigraphy with planar images (V/QS-planar is very useful for the diagnosis and follow-up of pulmonary thromboembolism (PTE. Acquiring tomographic images (V/QS-SPECT is a recent development with potential to increase the technique's accuracy. The purpose of this work is to evaluate the added benefits of V/QS-SPECT studies as opposed to traditional planar imaging. Patients and methods: We prospectively revised 53 V/QS-planar and V/QS-SPECT exams, performed according to the European Association of Nuclear Medicine guidelines. We evaluated the exams independently, by consensus of two Nuclear Medicine physicians. For both methods, we gave each lung a score expressing the dimension and extension of perfusion defects with normal ventilation. For each lung, we compared the scores with the paired Wilcoxon test, estimating the 95% confidence interval (95CI for the respective difference. Results: We performed V/QS-SPECT exams without technical difficulties. The paired Wilcoxon test estimated the score difference to be −0.75 (95CI of −1.0 to −0.5; p-value = 9.6 × 10−7, expressing a statistically significant difference of about 1 subsegmental defect between both methods, with V/QS-SPECT detecting more defects. Discussion: The results demonstrate that V/QS-SPECT identifies a slightly larger number of perfusion defects than V/QS-planar, suggesting a higher sensitivity of this technique. However, more studies are necessary to evaluate the clinical meaning of this fact. Conclusion: V/QS-SPECT demonstrates a higher capability to identify perfusion defects. This method looks promising, allowing for a greater role of this exam in pulmonary thromboembolism diagnosis and follow-up. Keywords: Pulmonary thromboembolism, Lung, Scintigraphy, Single-photon emission-computed tomography (SPECT

The place of krypton-81m ventilation in the scintigraphic investigation of the lung

International Nuclear Information System (INIS)

Hoefnagel, C.A.; Marcuse, H.R.

1983-01-01

Fairly recently krypton-81m gas became available for diagnostic purposes. Its advantages and ways to use are surveyed especially for the diagnosis of lung emboli and lung diseases. The combination of perfusion and ventilation scintigrams is the best for specifying the diagnosis. Krypton-81m gas improves the specificity and sensitivity of the examination which is non-invasive and carries no burden for the patient. (Auth.)

A new design for high stability pressure-controlled ventilation for small animal lung imaging

International Nuclear Information System (INIS)

Kitchen, M J; Habib, A; Lewis, R A; Fouras, A; Dubsky, S; Wallace, M J; Hooper, S B

2010-01-01

We have developed a custom-designed ventilator to deliver a stable pressure to the lungs of small animals for use in imaging experiments. Our ventilator was designed with independent pressure vessels to separately control the Peak Inspiratory Pressure (PIP) and Positive End Expiratory Pressure (PEEP) to minimise pressure fluctuations during the ventilation process. The ventilator was computer controlled through a LabVIEW interface, enabling experimental manipulations to be performed remotely whilst simultaneously imaging the lungs in situ. Mechanical ventilation was successfully performed on newborn rabbit pups to assess the most effective ventilation strategies for aerating the lungs at birth. Highly stable pressures enabled reliable respiratory gated acquisition of projection radiographs and a stable prolonged (15 minute) breath-hold for high-resolution computed tomography of deceased rabbit pups at different lung volumes.

67Ga lung scan

International Nuclear Information System (INIS)

Niden, A.H.; Mishkin, F.S.; Khurana, M.M.L.; Pick, R.

1977-01-01

Twenty-three patients with clinical signs of pulmonary embolic disease and lung infiltrates were studied to determine the value of gallium citrate 67 Ga lung scan in differentiating embolic from inflammatory lung disease. In 11 patients without angiographically proved embolism, only seven had corresponding ventilation-perfusion defects compatible with inflammatory disease. In seven of these 11 patients, the 67 Ga concentration indicated inflammatory disease. In the 12 patients with angiographically proved embolic disease, six had corresponding ventilation-perfusion defects compatible with inflammatory disease. None had an accumulation of 67 Ga in the area of pulmonary infiltrate. Thus, ventilation-perfusion lung scans are of limited value when lung infiltrates are present. In contrast, the accumulation of 67 Ga in the lung indicates an inflammatory process. Gallium imaging can help select those patients with lung infiltrates who need angiography

Value of the ventilation/perfusion scan in acute pulmonary embolism: Results of the prospective investigation of pulmonary embolism diagnosis (PIOPED)

International Nuclear Information System (INIS)

Anon.

1990-01-01

To determine the sensitivities and specificities of ventilation/perfusion lung scans for acute pulmonary embolism, a random sample of 933 of 1,493 patients was studied prospectively. Nine hundred thirty-one underwent scintigraphy and 755 underwent pulmonary angiography; 251 (33%) of 755 demonstrated pulmonary embolism. Almost all patients with pulmonary embolism had abnormal scans of high, intermediate, or low probability, but so did most without pulmonary embolism. Of 116 patients with high-probability scans and definitive angiograms, 102 (88%) had pulmonary embolism, but only a minority with pulmonary embolism had high-probability scans. Of 322 with intermediate-probability scans and definitive angiograms, 105 (33%) had pulmonary embolism. Follow-up and angiography together suggest pulmonary embolism occurred among 12% of patients with low-probability scans. Clinical assessment combined with the ventilation/perfusion scan established the diagnosis or exclusion of pulmonary embolism only for a minority of patients--those with clear and concordant clinical and ventilation/perfusion scan findings

Assessment of regional lung ventilation by electrical impedance tomography in a patient with unilateral bronchial stenosis and a history of tuberculosis.

Science.gov (United States)

Marinho, Liégina Silveira; Sousa, Nathalia Parente de; Barros, Carlos Augusto Barbosa da Silveira; Matias, Marcelo Silveira; Monteiro, Luana Torres; Beraldo, Marcelo do Amaral; Costa, Eduardo Leite Vieira; Amato, Marcelo Britto Passos; Holanda, Marcelo Alcantara

2013-01-01

Bronchial stenosis can impair regional lung ventilation by causing abnormal, asymmetric airflow limitation. Electrical impedance tomography (EIT) is an imaging technique that allows the assessment of regional lung ventilation and therefore complements the functional assessment of the lungs. We report the case of a patient with left unilateral bronchial stenosis and a history of tuberculosis, in whom regional lung ventilation was assessed by EIT. The EIT results were compared with those obtained by ventilation/perfusion radionuclide imaging. The patient was using nasal continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea syndrome. Therefore, we studied the effects of postural changes and of the use of nasal CPAP. The EIT revealed heterogeneous distribution of regional lung ventilation, the ventilation being higher in the right lung, and this distribution was influenced by postural changes and CPAP use. The EIT assessment of regional lung ventilation produced results similar to those obtained with the radionuclide imaging technique and had the advantage of providing a dynamic evaluation without radiation exposure.

Assessment of regional lung ventilation by electrical impedance tomography in a patient with unilateral bronchial stenosis and a history of tuberculosis

Directory of Open Access Journals (Sweden)

Liégina Silveira Marinho

2013-12-01

Full Text Available Bronchial stenosis can impair regional lung ventilation by causing abnormal, asymmetric airflow limitation. Electrical impedance tomography (EIT is an imaging technique that allows the assessment of regional lung ventilation and therefore complements the functional assessment of the lungs. We report the case of a patient with left unilateral bronchial stenosis and a history of tuberculosis, in whom regional lung ventilation was assessed by EIT. The EIT results were compared with those obtained by ventilation/perfusion radionuclide imaging. The patient was using nasal continuous positive airway pressure (CPAP for the treatment of obstructive sleep apnea syndrome. Therefore, we studied the effects of postural changes and of the use of nasal CPAP. The EIT revealed heterogeneous distribution of regional lung ventilation, the ventilation being higher in the right lung, and this distribution was influenced by postural changes and CPAP use. The EIT assessment of regional lung ventilation produced results similar to those obtained with the radionuclide imaging technique and had the advantage of providing a dynamic evaluation without radiation exposure.

A comparison of the economics of xenon 127, xenon 133 and krypton 81m for routine ventilation imaging of the lungs

International Nuclear Information System (INIS)

Nimmo, M.J.; Merrick, M.V.; Millar, A.M.

1985-01-01

The authors have compared the cost of providing routine lung ventilation scintigraphy using 127 Xe with other radioactive gases in 100 patients. The physical properties of 127 Xe permit a logical imaging sequence where a ventilation study is only carried out if indicated by perfusion scintigraphy which is performed first. With 133 Xe, all patients must be ventilated prospectively, or a preselection carried out based on radiographic appearances at the time of imaging. This results in a greater number of ventilation studies than with 127 Xe. Despite the greater cost per study of 127 Xe, the overall cost of providing a routine diagnostic service with this gas is no more than that of using 133 Xe in selected patients. The cost of ventilating all patients prospectively with 133 Xe is considerably greater than using 127 Xe only when indicated by abnormal perfusion images. If ventilation imaging is to be available at all times, either isotope of xenon costs very much less than 81 Krsup(m). It is concluded that 127 Xe is the radiopharmaceutical of choice for routine lung ventilation scintigraphy. (author)

Effect of one-lung ventilation on end-tidal carbon dioxide during cardiopulmonary resuscitation in a pig model of cardiac arrest.

Science.gov (United States)

Ryu, Dong Hyun; Jung, Yong Hun; Jeung, Kyung Woon; Lee, Byung Kook; Jeong, Young Won; Yun, Jong Geun; Lee, Dong Hun; Lee, Sung Min; Heo, Tag; Min, Yong Il

2018-01-01

Unrecognized endobronchial intubation frequently occurs after emergency intubation. However, no study has evaluated the effect of one-lung ventilation on end-tidal carbon dioxide (ETCO2) during cardiopulmonary resuscitation (CPR). We compared the hemodynamic parameters, blood gases, and ETCO2 during one-lung ventilation with those during conventional two-lung ventilation in a pig model of CPR, to determine the effect of the former on ETCO2. A randomized crossover study was conducted in 12 pigs intubated with double-lumen endobronchial tube to achieve lung separation. During CPR, the animals underwent three 5-min ventilation trials based on a randomized crossover design: left-lung, right-lung, or two-lung ventilation. Arterial blood gases were measured at the end of each ventilation trial. Ventilation was provided using the same tidal volume throughout the ventilation trials. Comparison using generalized linear mixed model revealed no significant group effects with respect to aortic pressure, coronary perfusion pressure, and carotid blood flow; however, significant group effect in terms of ETCO2 was found (P < 0.001). In the post hoc analyses, ETCO2 was lower during the right-lung ventilation than during the two-lung (P = 0.006) or left-lung ventilation (P < 0.001). However, no difference in ETCO2 was detected between the left-lung and two-lung ventilations. The partial pressure of arterial carbon dioxide (PaCO2), partial pressure of arterial oxygen (PaO2), and oxygen saturation (SaO2) differed among the three types of ventilation (P = 0.003, P = 0.001, and P = 0.001, respectively). The post hoc analyses revealed a higher PaCO2, lower PaO2, and lower SaO2 during right-lung ventilation than during two-lung or left-lung ventilation. However, the levels of these blood gases did not differ between the left-lung and two-lung ventilations. In a pig model of CPR, ETCO2 was significantly lower during right-lung ventilation than during two-lung ventilation. However

Assessment of smoking-induced impairment of pulmonary perfusion using three-dimensional SPECT images

Energy Technology Data Exchange (ETDEWEB)

Miyasaka, Takashi [Toho Univ., Tokyo (Japan). School of Medicine

1997-09-01

The effects of smoking on ventilation-perfusion lung scintigrams were investigated. The subjects comprised 40 healthy males (28 smokers and 12 nonsmokers) without a history of cardiopulmonary disease and with normal chest radiographs. After acquisition of planar images of ventilation lung scintigrams with 370 MBq of {sup 133}Xe gas, planar images and SPECT images of pulmonary perfusion flow were obtained using 185 MBq of {sup 99m}Tc-MAA. Planar imaging showed perfusion defects in only 5 smokers. In contrast, 16 subjects were found to have perfusion defects on SPECT images (p<0.05), indicating the usefulness of SPECT images in detecting minor vascular damage of the lung. Although perfusion defects were common in the smokers (p<0.05), their relationship to the BRINKMAN index was uncertain. The perfusion defects found in the smokers were nonsegmental and commonly involved the right upper lobe. Ventilation scans revealed only delayed washout of {sup 133}Xe in 4 smokers, suggesting that smoking-induced abnormal perfusion on SPECT appears earlier than impaired ventilation on scintigrams. (author)

Respiratory lung motion analysis using a nonlinear motion correction technique for respiratory-gated lung perfusion SPECT images

International Nuclear Information System (INIS)

Ue, Hidenori; Haneishi, Hideaki; Iwanaga, Hideyuki; Suga, Kazuyoshi

2007-01-01

This study evaluated the respiratory motion of lungs using a nonlinear motion correction technique for respiratory-gated single photon emission computed tomography (SPECT) images. The motion correction technique corrects the respiratory motion of the lungs nonlinearly between two-phase images obtained by respiratory-gated SPECT. The displacement vectors resulting from respiration can be computed at every location of the lungs. Respiratory lung motion analysis is carried out by calculating the mean value of the body axis component of the displacement vector in each of the 12 small regions into which the lungs were divided. In order to enable inter-patient comparison, the 12 mean values were normalized by the length of the lung region along the direction of the body axis. This method was applied to 25 Technetium (Tc)-99m-macroaggregated albumin (MAA) perfusion SPECT images, and motion analysis results were compared with the diagnostic results. It was confirmed that the respiratory lung motion reflects the ventilation function. A statistically significant difference in the amount of the respiratory lung motion was observed between the obstructive pulmonary diseases and other conditions, based on an unpaired Student's t test (P<0.0001). A difference in the motion between normal lungs and lungs with a ventilation obstruction was detected by the proposed method. This method is effective for evaluating obstructive pulmonary diseases such as pulmonary emphysema and diffuse panbronchiolitis. (author)

Lung-protective ventilation in neonatology

NARCIS (Netherlands)

van Kaam, Anton

2011-01-01

Ventilator-induced lung injury (VILI) is considered an important risk factor in the development of bronchopulmonary dysplasia (BPD) and is primarily caused by overdistension (volutrauma) and repetitive opening and collapse (atelectrauma) of terminal lung units. Lung-protective ventilation should

/sup 67/Ga lung scan

Energy Technology Data Exchange (ETDEWEB)

Niden, A.H.; Mishkin, F.S.; Khurana, M.M.L.; Pick, R.

1977-03-21

Twenty-three patients with clinical signs of pulmonary embolic disease and lung infiltrates were studied to determine the value of gallium citrate /sup 67/Ga lung scan in differentiating embolic from inflammatory lung disease. In 11 patients without angiographically proved embolism, only seven had corresponding ventilation-perfusion defects compatible with inflammatory disease. In seven of these 11 patients, the /sup 67/Ga concentration indicated inflammatory disease. In the 12 patients with angiographically proved embolic disease, six had corresponding ventilation-perfusion defects compatible with inflammatory disease. None had an accumulation of /sup 67/Ga in the area of pulmonary infiltrate. Thus, ventilation-perfusion lung scans are of limited value when lung infiltrates are present. In contrast, the accumulation of /sup 67/Ga in the lung indicates an inflammatory process. Gallium imaging can help select those patients with lung infiltrates who need angiography.

Evaluation of regional pulmonary ventilation by videodensitometry using a new X-ray image processor

International Nuclear Information System (INIS)

Fujii, Tadashige; Kanai, Hisakata; Handa, Kenjiro; Takizawa, Masaomi

1988-01-01

A new video image processing device has been produced in order to assess regional pulmonary ventilation. This device consists of a microcomputer, digital frame memory, digitizer, videomonitor, joystick and videotape recorder. The changing radiographic density of the lungs during deep respiration and forced expiration is recorded by the videotape recorder, which is connected to an image intensifier television system. This device allows the examining physician to place 6 rectangular windows of variable size over any portion of the video image using the joystick, and to measure the brightness level within these windows simultaneously. It is very characteristic that the video-densitometric curve and marks of the windows are superimposed on the frozen final frame of the sampled images. By this procedure, fair videodensigrams were obtained in various respiratory diseases, and reduction of ventilatory amplitude was shown in the hypoventilatory regions. The joint use of video-densitometry and perfusion lung scintigraphy provided helpful information concerning the regional ventilation/perfusion relationship. The videodensitometry of the lung the new X-ray image processor offers routine screening evaluation of regional pulmonary ventilation abnormalities over the entire video image of the lungs without more effort required of the patients. (author)

Study on incidence of pulmonary embolism in patients with cardiac pacemakers using lung perfusion mapping and ventilation scanning

International Nuclear Information System (INIS)

Yamashina, Hideki; Higo, Masanori; Sueda, Takashi

1990-01-01

We investigated pulmonary perfusion mapping and ventilation scanning employing 99mTC-MMA and 81mKr-Gas in patients with DDD and VVI cardiac pacemaker implantation. In 51 cases among 175 patients we observed some defects which matched the results from lung perfusion scanning in the pulmonary segments and sub-segments. These were diagnosed as pulmonary embolism after the possibility of other pulmonary diseases was rejected. The incidence rate of pulmonary embolism in patients with VVI (Ventricular pacing/sensing, inhibited type) pacemakers was 47 out of 138, or 34.1%, especially for those who received a pulmonary scanning examination whithin 6 months after pacemaker implantation. In contrast, those who were examined after 6 months had lower rates as well as chronological factors. The incidence rate of pulmonary embolism in 37 patients with DDD (Double chamber pacing/sensing, double modes of response) pacemakers was 10.8%, considerably lower than that for patients with VVI pacemakers. Therefore, one main factor of pulmonary embolism in patients with pacemakers could be the non-physiological phase of the contractions of both atria and ventricles. Other factors, such as the presence of foreign bodies in the endocardium, aging, and hypertension, could also promote pulmonary embolism. (author)

Lung-protective ventilation in abdominal surgery.

Science.gov (United States)

Futier, Emmanuel; Jaber, Samir

2014-08-01

To provide the most recent and relevant clinical evidence regarding the use of prophylactic lung-protective mechanical ventilation in abdominal surgery. Evidence is accumulating, suggesting an association between intraoperative mechanical ventilation strategy and postoperative pulmonary complications in patients undergoing abdominal surgery. Nonprotective ventilator settings, especially high tidal volume (>10-12 ml/kg), very low level of positive end-expiratory pressure (PEEP, ventilator-associated lung injury in patients with healthy lungs. Stimulated by the previous findings in patients with acute respiratory distress syndrome, the use of lower tidal volume ventilation is becoming increasingly more common in the operating room. However, lowering tidal volume, though important, is only part of the overall multifaceted approach of lung-protective mechanical ventilation. Recent data provide compelling evidence that prophylactic lung-protective mechanical ventilation using lower tidal volume (6-8 ml/kg of predicted body weight), moderate PEEP (6-8 cm H2O), and recruitment maneuvers is associated with improved functional or physiological and clinical postoperative outcome in patients undergoing abdominal surgery. The use of prophylactic lung-protective ventilation can help in improving the postoperative outcome.

Lung ventilation-perfusion scintigraphy in children on long-term parenteral nutrition

Energy Technology Data Exchange (ETDEWEB)

Pifarre, Paloma; Roca, Isabel [Universitat Autonoma de Barcelona, Department of Nuclear Medicine, Hospital de la Vall d' Hebron, Barcelona (Spain); Irastorza, Inaki; Hill, Susan [Great Ormond Street Hospital, Department of Gastroenterology, London (United Kingdom); Simo, Marc [Instituto Universitario Dexeus, Department of Nuclear Medicine, Barcelona (Spain); Biassoni, Lorenzo; Gordon, Isky [Great Ormond Street Hospital, Department of Nuclear Medicine, London (United Kingdom)

2009-06-15

Pulmonary emboli (PE) are one of the major complications associated with total parenteral nutrition (TPN). Ventilation-perfusion scintigraphy (V/Q) remains the most used test for the diagnosis of PE and follow-up of patients on TPN. The aim of our study was to demonstrate the high prevalence of undiagnosed PE in children on TPN. The medical and imaging files of 64 patients on TPN who underwent V/Q examinations covering the period of 1986-2004 were reviewed. Children were aged between 3.18 months and 21.6 years. TPN was started at birth (range 0-15 years). All children had a normal chest radiograph and no symptoms at the time of the V/Q scan. A comparative analysis between the prevalence of PE and risk factors number of days per week with lipophilic content of the TPN, bowel inflammation and thrombophilic factors (protein C and S) was performed. Of the 64 patients, 25 (39%) had an abnormal V/Q scan. A total of 29 PE episodes were diagnosed in all patients. Two children had three episodes of PE. The median age at PE diagnosis was 4.6 years. In 17 patients (68%) diagnosis was achieved on the first V/Q scan performed. PE was bilateral in 56% and unilateral in 44%. PE was the main cause of 2 out 15 recorded deaths. All risk factors were associated with an increase in PE prevalence by statistical analysis. PE is underdiagnosed in children on long-term TPN. Lung V/Q scintigraphy is useful in the diagnosis of PE in children with a low pretest probability. (orig.)

Functional Mechanism of Lung Mosaic CT Attenuation: Assessment with Deep-Inspiration Breath-Hold Perfusion SPECT-CT Fusion Imaging and Non-Breath-Hold Technegas SPECT

International Nuclear Information System (INIS)

Suga, K.; Yasuhiko, K.; Iwanaga, H.; Tokuda, O.; Matsunaga, N.

2009-01-01

Background: 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. Purpose: 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. Material and Methods: 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. Results: 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). Conclusion: Although further validation is

Functional Mechanism of Lung Mosaic CT Attenuation: Assessment with Deep-Inspiration Breath-Hold Perfusion SPECT-CT Fusion Imaging and Non-Breath-Hold Technegas SPECT

Energy Technology Data Exchange (ETDEWEB)

Suga, K.; Yasuhiko, K. (Dept. of Radiology, St. Hill Hospital, Ube, Yamaguchi (Japan)); Iwanaga, H.; Tokuda, O.; Matsunaga, N. (Dept. of Radiology, Yamaguchi Univ. School of Medicine, Ube, Yamaguchi (Japan))

2009-01-15

Background: 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. Purpose: 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. Material and Methods: 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. Results: 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). Conclusion: Although further validation is

Functional mechanism of lung mosaic CT attenuation: assessment with deep-inspiration breath-hold perfusion SPECT-CT fusion imaging and non-breath-hold Technegas SPECT.

Science.gov (United States)

Suga, K; Yasuhiko, K; Iwanaga, H; Tokuda, O; Matsunaga, N

2009-01-01

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

[Lung protective ventilation. Ventilatory modes and ventilator parameters].

Science.gov (United States)

Schädler, Dirk; Weiler, Norbert

2008-06-01

Mechanical ventilation has a considerable potential for injuring the lung tissue. Therefore, attention has to be paid to the proper choice of ventilatory mode and settings to secure lung-protective ventilation whenever possible. Such ventilator strategy should account for low tidal volume ventilation (6 ml/kg PBW), limited plateau pressure (30 to 35 cm H2O) and positive end-expiratory pressure (PEEP). It is unclear whether pressure controlled or volume controlled ventilation with square flow profile is beneficial. The adjustment of inspiration and expiration time should consider the actual breathing mechanics and anticipate the generation of intrinsic PEEP. Ventilatory modes with the possibility of supporting spontaneous breathing should be used as soon as possible.

Lung scintigraphy

International Nuclear Information System (INIS)

Dalenz, Roberto.

1994-01-01

A review of lung scintigraphy, perfusion scintigraphy with SPECT, lung ventilation SPECT, blood pool SPECT. The procedure of lung perfusion studies, radiopharmaceutical, administration and clinical applications, imaging processing .Results encountered and evaluation criteria after Biello and Pioped. Recommendations and general considerations have been studied about relation of this radiopharmaceutical with other pathologies

The predictive value of preoperative perfusion/ventilation scintigraphy, spirometry and x-ray of the lungs on postoperative pulmonary complications. A prospective study

International Nuclear Information System (INIS)

Fogh, J.; Wille-Joergensen, P.; Brynjolf, I.; Thorup, J.; Joergensen, T.; Bording, L.; Kjaergaard, J.

1987-01-01

Prospectively, 125 patients were examined with 99m Tc-perfusion scintigraphy, 89m Kr- or 127 Xe-ventilation scintigraphy and chest radiogram prior to major surgery. Postoperative therapy-demanding pulmonary complications occurred in 18% of the patients. A statistical association could be demonstrated between all the preoperative tests except ventilation scintigraphy and the frequency of complications. However, the predictive values of each of the tests, or even the combined results, were not significantly different from the frequency of complications among all the patients. It is concluded that the predictive values of perfusion-and ventilation scintigraphy, spirometry and radiogram of the chest are too low to be of any practical use. (author)

Prone positioning ventilation for treatment of acute lung injury and acute respiratory distress syndrome.

Science.gov (United States)

Lan, Mei-juan; He, Xiao-di

2009-08-01

Patients who are diagnosed with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) usually have ventilation-perfusion mismatch, severe decrease in lung capacity, and gas exchange abnormalities. Health care workers have implemented various strategies in an attempt to compensate for these pathological alterations. By rotating patients with ALI/ARDS between the supine and prone position, it is possible to achieve a significant improvement in PaO2/FiO2, decrease shunting and therefore improve oxygenation without use of expensive, invasive and experimental procedures. Prone positioning is a safe and effective way to improve ventilation when conventional strategies fail to initiate a patient response. Because a specific cure for ARDS is not available, the goal is to support the patients with therapies that cause the least amount of injury while the lungs have an opportunity to heal. Based on current data, a trial of prone positioning ventilation should be offered to the patients who have ALI/ARDS in the early course of the disease. Published studies exhibit substantial heterogeneity in clinical results, suggesting that an adequately sized study optimizing the duration of proning ventilation strategy is warranted to enable definitive conclusions to be drawn.

A comparative analysis of pulmonary ventilation-perfusion imaging with pulmonary angiography in the diagnosis of pulmonary embolism

International Nuclear Information System (INIS)

Wang Jincheng; Mi Hongzhi; Wang Qian; Zhang Weijun; Lu Biao; Yang Hao; Ding Jian; Lu Yao

2001-01-01

Objective: To assess the value of ventilation-perfusion imaging in the diagnosis of pulmonary embolism (PE). Methods: Thirty consecutive patients with clinically suspected pulmonary embolism were studied, male: female 15:15, mean age was (36.2 +- 13.9) years. The chest radiograms were obtained in all 30 patients. All patients underwent radionuclide ventilation-perfusion imaging and pulmonary angiography. Results: Of the 30 patients, 22 with lobe, multiple segment or multi-subsegment perfusion defects and normal or nearly normal ventilation images were reported as PE. 20 of them were confirmed to be with PE by pulmonary angiography, 2 patients were not confirmed. Eight of 30 patients with multiple perfusion defects, ventilative abnormalities were reported as non-PE and the diagnoses were confirmed by pulmonary angiography. The sensitivity, specificity and accuracy of diagnosis of PE by ventilation-perfusion imaging was 100%, 80.0% and 93.3% respectively. Conclusions: (1) Ventilation-perfusion imaging is one of the most valuable methods in the diagnosis of PE. (2) The results suggest that pulmonary embolism can be diagnosed non-invasively in most patients on the basis of clinical manifestation, chest radiograms and ventilation-perfusion imaging findings. (3) Pulmonary angiography is required while clinical manifestation and ventilation-perfusion imaging findings are discordant with each other

Ventilation-perfusion imaging and pulmonary angiography: changing pattern of use

International Nuclear Information System (INIS)

Teates, C.D.; Bezirdjian, D.R.; Bray, S.T.; Tegtmeyer, C.J.

1981-01-01

The hospital and departmental records of the University of Virginia Medical Center from 1976 to 1980 show an increasing frequency of ventilation studies relative to perfusion studies and a decrease in frequency of ventilation-perfusion diagnosis of pulmonary embolus. Pulmonary angiograms have increased from one per 68 nuclear studies to one per 14. A review of 70 patients with correlating angiography or autopsy shows that 89% of nuclear studies were accurate. We have revised our interpretation criteria and indications for pulmonary angiography

Study of lung perfusion in colagenosis

Energy Technology Data Exchange (ETDEWEB)

Macedo de Carvalho, A C; Calegaro, J U.M. [Fundacao Hospitalar do Distrito Federal, Distrito Federal (Brazil). Unidade de Medicina Nuclear

1982-07-01

The lung involvement in the various types of colagenosis has been widely described in the literature. However, the study of lung perfusion utilizing radionuclides has been only mentioned in a few papers. With the intention of ascertaining the importance of the lung perfusion scanning in colagenosis, ten cases were studied, seven of which were females and three males, with the following pathologies: 4 rheumatoid arthritis, 4 systemic lupus eritematosous, 1 scleroderma and 1 scleroderma plus dermatomyositis. The ages of the patients varied from 20 to 73 years, and the duration of the disease from 1 month to 39 years. The lung scanning showed perfusion defects in 100% of the cases, not related with the type of colagenosis, duration of the disease, sex or age. On the other hand, the X rays study showed alterations in only 2 patients (20% of the cases). The ventilatory and respiratory functions were tested on 7 patients showing alteration (mixed pattern with predominance of the restrictive factor) in only one (14.3%), while the other patients were normal (85.7%). The importance of the lung perfusion scanning study in all patients with collagen vascular diseases is emphasized.

Study of lung perfusion in colagenosis

International Nuclear Information System (INIS)

Macedo de Carvalho, A.C.; Calegaro, J.U.M.

1982-01-01

The lung involvement in the various types of colagenosis has been widely described in the literature. However, the study of lung perfusion utilizing radionuclides has been only mentioned in a few papers. With the intention of ascertaining the importance of the lung perfusion scanning in colagenosis, ten cases were studied, seven of which were females and three males, with the following pathologies: 4 rheumatoid arthritis, 4 systemic lupus eritematosous, 1 scleroderma and 1 scleroderma plus dermatomyositis. The ages of the patients varied from 20 to 73 years, and the duration of the disease from 1 month to 39 years. The lung scanning showed perfusion defects in 100% of the cases, not related with the type of colagenosis, duration of the disease, sex or age. On the other hand, the X rays study showed alterations in only 2 patients (20% of the cases). The ventilatory and respiratory functions were tested on 7 patients showing alteration (mixed pattern with predominance of the restrictive factor) in only one (14.3%), while the other patients were normal (85.7%). The importance of the lung perfusion scanning study in all patients with collagen vascular diseases is emphasized. (author) [es

Lung perfusion scintigraphy by SPECT

International Nuclear Information System (INIS)

Hirayama, Takanobu

1990-01-01

The initial study reports the characteristic performance using lung segmental phantom filled in Tc-99m pertechnetate. To evaluate the segmental defect in lung perfusion scintigraphy, we applied Bull's-eye analysis in addition to planar image set. Bull's-eye analysis especially facilitated the interpretation in both middle and lower lobes. Subsequently, to evolute the clinical application of Bull's-eye analysis, pulmonary scintigraphy was performed on 10 normal subjects and 60 patients with several pulmonary diseases. Of interest, Bull's-eye analysis, however, encouraged the interpretation in both lower lobes. To calculate the extention and severity of perfusion defect, the present study describes Bull's-eye analysis. Quantitative scoring showed higher in patients with lung cancer than those with pulmonary tuberculosis. The present study focus that Bull's-eye analysis can be useful for evaluating perfusion in patients with a couple of pulmonary diseases. (author)

Histochemical alterations in one lung ventilation.

Science.gov (United States)

Yin, Kingsley; Gribbin, Elizabeth; Emanuel, Steven; Orndorff, Rebecca; Walker, Jean; Weese, James; Fallahnejad, Manucher

2007-01-01

One lung ventilation is a commonly performed surgical procedure. Although there have been several reports showing that one-lung ventilation can cause pathophysiological alterations such as pulmonary hypoxic vasoconstriction and intrapulmonary shunting, there have been virtually no reports on the effects of one-lung ventilation on lung histology. Yorkshire pigs (11-17 kg) were anesthetized, a tracheotomy performed and a tracheal tube inserted. The chest was opened and one lung ventilation (OLV), was induced by clamping of the right main bronchus. OLV was continued for 60 min before the clamp was removed and two lung ventilation (TLV) started. TLV was continued for 30 to 60 min. Blood and lung biopsies were taken immediately before OLV, 30 min and 60 min of OLV and after restoration of TLV. Histological analyses revealed that the non-ventilated lung was totally collapsed during OLV. On reventilation, there was clear evidence of vascular congestion and alveolar wall thickening at 30 min after TLV. At 60 min of TLV, there was still vascular congestion. Serum nitrite levels (as an index of nitric oxide production) showed steady decline over the course of the experimental period, reaching a significantly low level on reventilation (compared with baseline levels before OLV). Lung MPO activity (marker of neutrophil sequestration) and serum TNFalpha levels were not raised during the entire experimental period. These results suggest that there was lung vascular injury after OLV, which was associated with reduced levels of nitric oxide production and not associated with an inflammatory response.

Assessment of lung ventilation by MR imaging: current status and future perspectives

International Nuclear Information System (INIS)

Kauczor, Hans-Ulrich; Hanke, Alexander; Beek, Edwin J.R. van

2002-01-01

The aim of this paper is to review the present status of novel MRI techniques as a new important instrument for functional ventilation imaging. The current status and future perspectives in research and clinical applications are summarized. Morphological lung imaging is based on chest radiography and computed tomography, whereas scintigraphy is used for ventilation imaging. During recent years, MRI has emerged as a new means for functional imaging of ventilation. Aerosolized contrast agents and oxygen are used in proton imaging, whereas non-proton imaging relies on fluorine compounds, such as sulfur hexafluoride and perfluorcarbons, or on hyperpolarized noble gases, such as helium-3 or xenon-129. All the gases are administered as inhaled ''contrast agents'' for imaging of the airways and airspaces. In general, straightforward images demonstrate the homogeneity of ventilation in a breath-hold and allow for determination of ventilated lung. The different properties of the different compounds enable the measurement of additional functional parameters. They comprise airspace size, regional oxygen partial pressure, and analysis of ventilation distribution, ventilation/perfusion ratios, and gas exchange, including oxygen uptake. Novel MRI techniques provide the potential for functional imaging of ventilation. The next steps include definition of the value and the potential of the different contrast mechanisms as well as determination of the significance of the functional information with regard to physiological research and patient management in chronic obstructive pulmonary disease and others. (orig.)

Changes in regional and overall lung function after bronchography

International Nuclear Information System (INIS)

Richez, M.; Ravez, P.; Godart, G.; Halloy, J.L.; Robience, Y.

1980-01-01

This investigation compares the effects of unilateral bronchography on classical pulmonary function paramerts (spirometry, CO transfer, flowvolume curve, and arterial blood gases)and radioisotopic measurements by means of 99 sup(m)Tc-labeled microspheres and 81 sup(m)Kr. The regional changes of ventilation and perfusion were quantified by a radioisotopic index, which was established for each zone of interest: explored lung and unexplored lung. The quantitative study of regional perfusion and ventilation reveals significant reduction of ventilation for lung bases, but not for lung apices. The radioisotopic measurements show a reduction of perfusion parallel to the reduction of ventilation. There is no significant correlation between traditional pulmonary function parameters and isotopic indices. Radioisotopy proved a sensitive tool for investigation of unilateral alterations. (orig.) [de

Are lung-protective ventilation strategies worth the effort? | Slinger ...

African Journals Online (AJOL)

Nonphysiological ventilation in healthy lungs induces acute lung injury (ALI). Protective lung ventilation in patients with ALI improves outcome. Protective lung ventilation in noninjured lungs and in the absence of a primary pulmonary insult may initiate ventilation-induced lung injury (VILI), as evidenced by inflammatory ...

Variable tidal volumes improve lung protective ventilation strategies in experimental lung injury.

Science.gov (United States)

Spieth, Peter M; Carvalho, Alysson R; Pelosi, Paolo; Hoehn, Catharina; Meissner, Christoph; Kasper, Michael; Hübler, Matthias; von Neindorff, Matthias; Dassow, Constanze; Barrenschee, Martina; Uhlig, Stefan; Koch, Thea; de Abreu, Marcelo Gama

2009-04-15

Noisy ventilation with variable Vt may improve respiratory function in acute lung injury. To determine the impact of noisy ventilation on respiratory function and its biological effects on lung parenchyma compared with conventional protective mechanical ventilation strategies. In a porcine surfactant depletion model of lung injury, we randomly combined noisy ventilation with the ARDS Network protocol or the open lung approach (n = 9 per group). Respiratory mechanics, gas exchange, and distribution of pulmonary blood flow were measured at intervals over a 6-hour period. Postmortem, lung tissue was analyzed to determine histological damage, mechanical stress, and inflammation. We found that, at comparable minute ventilation, noisy ventilation (1) improved arterial oxygenation and reduced mean inspiratory peak airway pressure and elastance of the respiratory system compared with the ARDS Network protocol and the open lung approach, (2) redistributed pulmonary blood flow to caudal zones compared with the ARDS Network protocol and to peripheral ones compared with the open lung approach, (3) reduced histological damage in comparison to both protective ventilation strategies, and (4) did not increase lung inflammation or mechanical stress. Noisy ventilation with variable Vt and fixed respiratory frequency improves respiratory function and reduces histological damage compared with standard protective ventilation strategies.

Ventilation and perfusion imaging by electrical impedance tomography: a comparison with radionuclide scanning

NARCIS (Netherlands)

Kunst, P. W.; Vonk Noordegraaf, A.; Hoekstra, O. S.; Postmus, P. E.; de Vries, P. M.

1998-01-01

Electrical impedance tomography (EIT) is a technique that makes it possible to measure ventilation and pulmonary perfusion in a volume that approximates to a 2D plane. The possibility of using EIT for measuring the left-right division of ventilation and perfusion was compared with that of

Clinical studies on combined ventilation (sup(81m)Kr)/perfusion (sup(99m)Tc-MAA) scintigraphy. With special reference to the 'mismatch' patterns and their significance

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Yamamoto, Keiichiro; Miyamae, Tatsuya [Saitama Medical School (Japan)

1983-01-01

One hundred fifty patients having pulmonary disease underwent pulmonary scintigraphy sequentially with sup(99m)Tc-MAA and sup(81m)Kr gases. Scintigrams of matched defect were obtained from 113 (75.3%) of the 150 patients, considered to be nonspecific universal pattern of a pulmonary disease. Scintigrams of mismatched defect (absent perfusion and homogeneous ventilation) were obtained from 20 patients (13.3%), including 6 with lung carcinoma, 3 with pulmonary embolism, 3 with connective tissue disease, 2 with aortitis syndrome and 6 with other diseases. Scintigrams of mismatch with impaired ventilation and normal perfusion were mainly seen in chronic obstructive lung diseases. Of the 10 patients with bronchial asthma, 5 had scintigrams of improved ventilation after intravenous injection of 250 mg aminophilline, but none of patients with emphysema. The combined scintigraphy has made significant contributions to diagnosis and management of patients with pulmonary disease where the chest X-ray is unhelpful.

Serial perfusion in native lungs in patients with idiopathic pulmonary fibrosis and other interstitial lung diseases after single lung transplantation.

Science.gov (United States)

Sokai, Akihiko; Handa, Tomohiro; Chen, Fengshi; Tanizawa, Kiminobu; Aoyama, Akihiro; Kubo, Takeshi; Ikezoe, Kohei; Nakatsuka, Yoshinari; Oguma, Tsuyoshi; Hirai, Toyohiro; Nagai, Sonoko; Chin, Kazuo; Date, Hiroshi; Mishima, Michiaki

2016-04-01

Lung perfusions after single lung transplantation (SLT) have not been fully clarified in patients with interstitial lung disease (ILD). The present study aimed to investigate temporal changes in native lung perfusion and their associated clinical factors in patients with ILD who have undergone SLT. Eleven patients were enrolled. Perfusion scintigraphy was serially performed up to 12 months after SLT. Correlations between the post-operative perfusion ratio in the native lung and clinical parameters, including pre-operative perfusion ratio and computed tomography (CT) volumetric parameters, were evaluated. On average, the perfusion ratio of the native lung was maintained at approximately 30% until 12 months after SLT. However, the ratio declined more significantly in idiopathic pulmonary fibrosis (IPF) than in other ILDs (p = 0.014). The perfusion ratio before SLT was significantly correlated with that at three months after SLT (ρ = 0.64, p = 0.048). The temporal change of the perfusion ratio in the native lung did not correlate with those of the CT parameters. The pre-operative perfusion ratio may predict the post-operative perfusion ratio of the native lung shortly after SLT in ILD. Perfusion of the native lung may decline faster in IPF compared with other ILDs. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Correlation of the perfusion scintigram with pulmonary functions in chronic obstructive pulmonary disease

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Uchida, Kou; Ashitaka, Tsuyoshi; Uchibori, Shigeyasu [Toho Univ., Tokyo (Japan). School of Medicine; Takano, Masaaki

1992-11-01

The authors carried out ventilation-perfusion scintigraphy and pulmonary function tests in 21 patients with chronic obstructive pulmonary disease. It was used [sup 99m]Tc-macroaggregate for perfusion scintigram and [sup 133]Xe gas for ventilation scintigram. It was added the radioactivities of rebreathing phase and made lung volume image using a computer. Regions of interest (ROIs) were derived from radioactivities in each image. ROIs on lung volume image included each whole lung and those on perfusion image included the areas which had relatively high radioactivity. The authors counted the area of ROIs on lung volume (L) and perfusion (P) images. Then it was used the ratio of perfusion to lung volume (P/L) as a parameter of pulmonary perfusion. P/L had the significant correlations with the vital capacity, the actual FFV[sub 1.0], arterial oxygen partial pressure, diffusing capacity, RV/TLC and peak flow rate. These results suggested that P/L was a useful parameter of pulmonary perfusion in chronic obstructive pulmonary disease. (author).

Recent lung imaging studies

International Nuclear Information System (INIS)

Taplin, G.V.; Chopra, S.K.

1976-01-01

Radionuclide lung imaging procedures have been available for 11 years but only the perfusion examination has been used extensively and mainly for the diagnosis of pulmonary embolism (P.E.). Its ability to reveal localized ischemia makes it a valuable test of regional lung function as well as a useful diagnostic aid in P.E. Although it had been recognized for several years that chronic obstructive pulmonary disease (COPD) can cause lung perfusion defects which may simulate pulmonary embolism, relatively little use has been made of either the radioxenon or the radioaerosol inhalation lung imaging procedures until the last few years as a means of distinguishing P.E. from COPD. In this review emphasis is placed on our recent experience with both of these inhalation procedures in comparison with pulmonary function tests and roentgenography for the early detection of COPD in population studies. Equal emphasis is given to simultaneous aerosol ventilation-perfusion (V/P) imaging for a functional diagnosis of P.E. Two new developments in regional lung diffusion imaging, performed after the inhalation of radioactive gases and/or rapidly absorbed radioaerosols are described. The experimental basis for their potential clinical application in pulmonary embolism detection is presented

A porcine ex vivo lung perfusion model with maximal argon exposure to attenuate ischemia-reperfusion injury

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An Martens

2017-01-01

Full Text Available Argon (Ar is a noble gas with known organoprotective effects in rodents and in vitro models. In a previous study we failed to find a postconditioning effect of Ar during ex vivo lung perfusion (EVLP on warm-ischemic injury in a porcine model. In this study, we further investigated a prolonged exposure to Ar to decrease cold ischemia-reperfusion injury after lung transplantation in a porcine model with EVLP assessment. Domestic pigs (n = 6/group were pre-conditioned for 6 hours with 21% O 2 and 79% N 2 (CONTR or 79% Ar (ARG. Subsequently, lungs were cold flushed and stored inflated on ice for 18 hours inflated with the same gas mixtures. Next, lungs were perfused for 4 hours on EVLP (acellular while ventilated with 12% O 2 and 88% N 2 (CONTR group or 88% Ar (ARG group. The perfusate was saturated with the same gas mixture but with the addition of CO 2 to an end-tidal CO 2 of 35-45 mmHg. The saturated perfusate was drained and lungs were perfused with whole blood for an additional 2 hours on EVLP. Evaluation at the end of EVLP did not show significant effects on physiologic parameters by prolonged exposure to Ar. Also wet-to-dry weight ratio did not improve in the ARG group. Although in other organ systems protective effects of Ar have been shown, we did not detect beneficial effects of a high concentration of Ar on cold pulmonary ischemia-reperfusion injury in a porcine lung model after prolonged exposure to Ar in this porcine model with EVLP assessment.

Pulmonary Perfusion and Ventilation During Cardiopulmonary Bypass Are Not Associated with Improved Postoperative Outcomes After Cardiac Surgery

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Yiliam F Rodriguez-Blanco

2016-11-01

Full Text Available ObjectivesClinical trials of either pulmonary perfusion or ventilation during cardiopulmonary bypass are equivocal. We hypothesized that to achieve significant improvement in outcomes both interventions had to be concurrent.DesignRetrospective case-control studySettingsMajor academic tertiary referral medical centerParticipants274 consecutive patients who underwent open heart surgery with cardiopulmonary bypass 2009 - 2013.InterventionsThe outcomes of 86 patients who received pulmonary perfusion and ventilation during cardiopulmonary bypass were retrospectively compared to the control group of 188 patients.Measurements and Main ResultsRespiratory complications rates were similar in both groups (33.7% vs. 33.5%, as were the rates of postoperative pneumonia (4.7% vs. 4.3%, pleural effusions (13.9% vs. 12.2% and re-intubations (9.3% vs. 9.1%. Rates of adverse postoperative cardiac events including ventricular tachycardia (9.3% vs. 8.5% and atrial fibrillation (33.7% vs. 28.2% were equivalent in both groups. Incidence of sepsis (8.1% vs. 5.3%, postoperative stroke (2.3% vs. 2.1%, acute kidney injury (2.3% vs. 3.7% and renal failure (5.8% vs. 3.7% were likewise comparable. Despite similar transfusion requirements, coagulopathy (12.8% vs. 5.3%, p=0.031 and the need for mediastinal re-exploration (17.4% vs. 9.6%, p=0.0633 were observed more frequently in the pulmonary perfusion and ventilation group, but the difference did not reach the statistical significance. ICU and hospital stays, and the ICU readmission rates (7.0% vs. 8.0% were similar in both groups.ConclusionsSimultaneous pulmonary perfusion and ventilation during cardiopulmonary bypass were not associated with improved clinical outcomes.

Lung scintigraphy; Centellograma pulmonar

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Dalenz, Roberto

1994-12-31

A review of lung scintigraphy, perfusion scintigraphy with SPECT, lung ventilation SPECT, blood pool SPECT. The procedure of lung perfusion studies, radiopharmaceutical, administration and clinical applications, imaging processing .Results encountered and evaluation criteria after Biello and Pioped. Recommendations and general considerations have been studied about relation of this radiopharmaceutical with other pathologies.

Lung perfusion and emphysema distribution affect the outcome of endobronchial valve therapy

Directory of Open Access Journals (Sweden)

Thomsen C

2016-06-01

Full Text Available Christian Thomsen,1 Dorothea Theilig,2 Dominik Herzog,1 Alexander Poellinger,2 Felix Doellinger,2 Nils Schreiter,3 Vera Schreiter,2 Dirk Schürmann,1 Bettina Temmesfeld-Wollbrueck,1 Stefan Hippenstiel,1 Norbert Suttorp,1 Ralf-Harto Hubner1 1Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, 2Institute of Radiology, 3Institute of Nuclear Medicine, Charité – Universitätsmedizin Berlin, Berlin, Germany Abstract: The exclusion of collateral ventilation (CV and other factors affect the clinical success of endoscopic lung volume reduction (ELVR. However, despite its benefits, the outcome of ELVR remains difficult to predict. We investigated whether clinical success could be predicted by emphysema distribution assessed by computed tomography scan and baseline perfusion assessed by perfusion scintigraphy. Data from 57 patients with no CV in the target lobe (TL were retrospectively analyzed after ELVR with valves. Pulmonary function tests (PFT, St George’s Respiratory Questionnaire (SGRQ, and 6-minute walk tests (6MWT were performed on patients at baseline. The sample was grouped into high and low levels at the median of TL perfusion, ipsilateral nontarget lobe (INL perfusion, and heterogeneity index (HI. These groups were analyzed for association with changes in outcome parameters from baseline to 3 months follow-up. Compared to baseline, patients showed significant improvements in PFT, SGRQ, and 6MWT (all P≤0.001. TL perfusion was not associated with changes in the outcome. High INL perfusion was significantly associated with increases in 6MWT (P=0.014, and high HI was associated with increases in forced expiratory volume in 1 second (FEV1, (P=0.012. Likewise, there were significant correlations for INL perfusion and improvement of 6MWT (r=0.35, P=0.03 and for HI and improvement in FEV1 (r=0.45, P=0.001. This study reveals new attributes that associate with positive outcomes for patient selection prior to ELVR

Normal anatomy of lung perfusion SPECT scintigraphy

International Nuclear Information System (INIS)

Moskowitz, G.W.; Levy, L.M.

1987-01-01

Ten patients studies for possible pulmonary embolic disease had normal lung perfusion planar and SPECT scintigraphy. A computer program was developed to superimpose the CT scans on corresponding SPECT images. Superimposition of CT scans on corresponding SPECT transaxial cross-sectional images, when available, provides the needed definition and relationships of adjacent organs. SPECT transaxial sections provide clear anatomic definition of perfusion defects without foreground and background lung tissue superimposed. The location, shape, and size of the perfusion defects can be readily assessed by SPECT. An algorithm was developed for the differentiation of abnormal pulmonary perfusion patterns from normal structures on variation

Single-Lung Ventilation with Contralateral Lung Deflation

Science.gov (United States)

Dallan, Luís Alberto O.; Lisboa, Luiz Augusto F.; Platania, Fernando; Oliveira, Sérgio A.; Stolf, Noedir A.

2007-01-01

There are many new alternative methods of minimally invasive myocardial revascularization that can be applied in selected patients who have multivessel coronary artery disease. However, these techniques often require new and expensive equipment. Most multivessel myocardial revascularization is performed via median sternotomy and involves the use of a conventional endotracheal tube. Both lungs are ventilated, and frequently the left pleural cavity is opened. In contrast, single-lung deflation naturally moves the mediastinum within the thorax toward the collapsed lung, without the need to open the pleural cavities. Herein, we describe a simple alternative procedure that facilitates off-pump multivessel coronary artery bypass grafting via complete median sternotomy: single-lung ventilation with contralateral lung deflation. This technique better exposes the more distal right and circumflex coronary artery branches with or without the opening of the pleural cavities. PMID:17622364

Pre- and postoperative ventilation-perfusion scan findings in patients undergoing total hip replacement or knee arthroplasty

International Nuclear Information System (INIS)

Kim, S.M.; Park, C.H.; Intenzo, C.M.

1988-01-01

Venous thrombolembolism is one of the major postoperative complications in patients undergoing total hip replacement (THR) or knee anthroplasty (TKA). The reported incidence of pulmonary embolism in this group is as high as 20%. The purpose of this report was to evaluate the value of preoperative and 7th-day postpoperative ventilation-perfusion (V/Q) lung scans in the management of patients undergoing elective reconstructive surgery of the hips or knees. Routine preoperative and 7th-day postoperative V/Q lung scans were obtained in 34 patients who underwent THR (17 patients) or TKA (17 patients). There were 15 male and 19 female patients, with an age distribution ranging from 56 to 80 years. Chest radiographs were obtained within 1 day of the pre- or postoperative lungs scan. Lung scans were interpreted by two experienced nuclear physicians

Lung ventilation injures areas with discrete alveolar flooding, in a surface tension-dependent fashion.

Science.gov (United States)

Wu, You; Kharge, Angana Banerjee; Perlman, Carrie E

2014-10-01

With proteinaceous-liquid flooding of discrete alveoli, a model of the edema pattern in the acute respiratory distress syndrome, lung inflation over expands aerated alveoli adjacent to flooded alveoli. Theoretical considerations suggest that the overexpansion may be proportional to surface tension, T. Yet recent evidence indicates proteinaceous edema liquid may not elevate T. Thus whether the overexpansion is injurious is not known. Here, working in the isolated, perfused rat lung, we quantify fluorescence movement from the vasculature to the alveolar liquid phase as a measure of overdistension injury to the alveolar-capillary barrier. We label the perfusate with fluorescence; micropuncture a surface alveolus and instill a controlled volume of nonfluorescent liquid to obtain a micropunctured-but-aerated region (control group) or a region with discrete alveolar flooding; image the region at a constant transpulmonary pressure of 5 cmH2O; apply five ventilation cycles with a positive end-expiratory pressure of 0-20 cmH2O and tidal volume of 6 or 12 ml/kg; return the lung to a constant transpulmonary pressure of 5 cmH2O; and image for an additional 10 min. In aerated areas, ventilation is not injurious. With discrete alveolar flooding, all ventilation protocols cause sustained injury. Greater positive end-expiratory pressure or tidal volume increases injury. Furthermore, we determine T and find injury increases with T. Inclusion of either plasma proteins or Survanta in the flooding liquid does not alter T or injury. Inclusion of 2.7-10% albumin and 1% Survanta together, however, lowers T and injury. Contrary to expectation, albumin inclusion in our model facilitates exogenous surfactant activity. Copyright © 2014 the American Physiological Society.

The diagnostic value of ventilation-perfusion scintigraphy combined with plasma D-dimer assay in diagnosis of pulmonary embolism

International Nuclear Information System (INIS)

Wang Qian; Huang Lili; Qin Shuling; Yue Minggang; Wang Yu; Nie Yuxin; Liang Tiejun

2005-01-01

Objective: To investigate the clinical diagnostic value of ventilation-perfusion scintigraphy combined with plasma D-dimer assay in diagnosis of pulmonary embolism (PE). Methods: One hundred and four patients with clinically suspected PE underwent both pulmonary ventilation-perfusion scintigraphy and plasma D-dimer assay. According to the criteria of prospective investigation of the pulmonary embolism diagnosis (PIOPED), ventilation-perfusion scintigraphy was interpreted as normal, very low or low probability of PE, intermediate probability of PE and high probability of PE. High probability was considered as positive; normal and very low or low probability as negative and intermediate probability as non-diagnostic. Plasma D-dimer levels were measured using a quantitative immunoturbidimetric method, and a cut-off value of 500 mg/L was used in the diagnosis of PE. Clinical diagnostic value of ventilation-perfusion scintigraphy, D-dimer assay and combined use of ventilation-perfusion scintigraphy and D-dimer assay for diagnosing PE was evaluated, respectively, comparing with the final clinical diagnosis that was based on the clinical findings. Results: Among the 104 patients, 44 were diagnosed with PE and 60 were excluded. Ventilation-perfusion scintigraphy provided diagnostic interpretations for 86 (82.7%) patients, and non-diagnostic interpretations for 18 (17.3%) patients. For diagnosing PE, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of ventilation-perfusion scintigraphy was 84.1%, 75.0%, 78.8%, 71.2% and 86.5%, respectively, and with D-dimer assay was 93.2%, 60.0%, 74.0%, 63.1% and 92.3%, respectively. If a plasma D-dimer level of < 500 mg/L was taken as a criterion to exclude PE for those intermediate probability of ventilation-perfusion scintigraphy, the diagnostic specificity and accuracy would be raised to 85.0% and 84.6%, respectively. Conclusions: When a non-diagnostic interpretation was occurred on

Influence of perfusion and ventilation scans on therapeutic decision making and outcome in cases of possible embolism

International Nuclear Information System (INIS)

Mercandetti, A.J.; Kipper, M.S.; Moser, K.M.

1985-01-01

The authors examined the influence of perfusion (Q) and ventilation (V) scans on therapeutic decision making and outcome among 229 patients referred for lung scans because embolism was suggested and found that specific V/Q scan patterns strongly influenced postscan decisions regarding initiation, maintenance or cessation of heparin therapy. These therapeutic decisions bore a relationship to outcome (recurrences and death) and disclosed decision-making deficits that need remedy by future investigational and educational efforts. 25 references, 5 tables

Arterio-venous anastomoses in isolated, perfused rat lungs.

Science.gov (United States)

Conhaim, Robert L; Segal, Gilad S; Watson, Kal E

2016-11-01

Several studies have suggested that large-diameter (>25 μm) arterio-venous shunt pathways exist in the lungs of rats, dogs, and humans. We investigated the nature of these pathways by infusing specific-diameter fluorescent latex particles (4, 7, 15, 30, or 50 μm) into isolated, ventilated rat lungs perfused at constant pressure. All lungs received the same mass of latex (5 mg), which resulted in infused particle numbers that ranged from 1.7 × 10 7 4 μm particles to 7.5 × 10 4 50 μm particles. Particles were infused over 2 min. We used a flow cytometer to count particle appearances in venous effluent samples collected every 0.5 min for 12 min from the start of particle infusion. Cumulative percentages of infused particles that appeared in the samples averaged 3.17 ± 2.46% for 4 μm diameter particles, but ranged from 0.01% to 0.17% for larger particles. Appearances of 4 μm particles followed a rapid upslope beginning at 30 sec followed by a more gradual downslope that lasted for up to 12 min. All other particle diameters also began to appear at 30 sec, but followed highly irregular time courses. Infusion of 7 and 15 μm particles caused transient but significant perfusate flow reductions, while infusion of all other diameters caused insignificant reductions in flow. We conclude that small numbers of bypass vessels exist that can accommodate particle diameters of 7-to-50 μm. We further conclude that our 4 μm particle data are consistent with a well-developed network of serial and parallel perfusion pathways at the acinar level. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

[Lung protective ventilation - pathophysiology and diagnostics].

Science.gov (United States)

Uhlig, Stefan; Frerichs, Inéz

2008-06-01

Mechanical ventilation may lead to lung injury depending on the ventilatory settings (e.g. pressure amplitudes, endexpiratory pressures, frequency) and the length of mechanical ventilation. Particularly in the inhomogeneously injured lungs of ARDS patients, alveolar overextension results in volutrauma, cyclic opening and closure of alveolar units in atelectrauma. Particularly important appears to be the fact that these processes may also cause biotrauma, i.e. the ventilator-induced hyperactivation of inflammatory responses in the lung. These side effects are reduced, but not eliminated with the currently recommended ventilation strategy with a tidal volume of 6 ml/kg idealized body weight. It is our hope that in the future optimization of ventilator settings will be facilated by bedside monitoring of novel indices of respiratory mechanics such as the stress index or the Slice technique, and by innovative real-time imaging technologies such as electrical impedance tomography.

Lung radiopharmaceuticals

International Nuclear Information System (INIS)

Gonzalez, B.M.

1994-01-01

Indication or main clinical use of Lung radiopharmaceuticals is presented and clasification of radiopharmaceuticals as ventilation and perfusion studies. Perfusion radiopharmaceuticals, main controls for administration quality acceptance. Clearence after blood administration and main clinical applications. Ventilation radiopharmaceuticals, gases and aerosols, characteristics of a ideal radioaerosol, techniques of good inhalation procedure, clinical applications. Comparison of several radiopharmaceuticals reflering to retention time as 50% administered dose, percent administered dose at 6 hours post inhalation, blood activity at 30 and 60 minutes post inhalation, initial lung absorbed dose, cumulated activity.Kinetic description of two radiopharmaceuticals, 99mTcDTPA and 99mTc-PYP

History of Mechanical Ventilation. From Vesalius to Ventilator-induced Lung Injury.

Science.gov (United States)

Slutsky, Arthur S

2015-05-15

Mechanical ventilation is a life-saving therapy that catalyzed the development of modern intensive care units. The origins of modern mechanical ventilation can be traced back about five centuries to the seminal work of Andreas Vesalius. This article is a short history of mechanical ventilation, tracing its origins over the centuries to the present day. One of the great advances in ventilatory support over the past few decades has been the development of lung-protective ventilatory strategies, based on our understanding of the iatrogenic consequences of mechanical ventilation such as ventilator-induced lung injury. These strategies have markedly improved clinical outcomes in patients with respiratory failure.

Lung inhalation scintigraphy with radioactive aerosols in several pulmonary diseases

International Nuclear Information System (INIS)

Martins, L.R.; Marioni Filho, H.; Romaldini, H.; Uehara, C.; Alonso, G.

1983-01-01

The pulmonary ventilation scintigraphy with 99m Tc diethylene-triamine-pentaacetate (99mTc-DTPA) delivered through a new nebulizer system when analyzed together with the classic lung perfusion scintigraphy with 99mTc-labeled albumin macroaggregates (99mTcMAA) is a very important diagnostic tool in several pulmonary diseases. Several aspects of the lung ventilation-perfusion scintigraphy are studied in 15 people with no lung disease, smokers and nonsmokers. The findings with the lung ventilation-perfusion scintigraphy are also discussed in 34 patients with several pulmonary diseases: lung cancer, chronic obstructive lung disease, policystic pulmonary disease, and pulmonary embolims. The authors concluded that the procedure is a valuable diagnostic tool in several pulmonary diseases, especially because good lung images are obtained, no side effects were detected, the technique is ease and low cost, and it brings new informations, not available with other diagnostic methods. (author)

Effects of isoproterenol on distribution of perfusion in embolized dog lungs

International Nuclear Information System (INIS)

Shepard, J.W. Jr.; Hauer, D.; Sgroi, V.; Moser, K.M.

1979-01-01

In 19 mechanically ventilated, anesthetized dogs, autologous venous thrombi were formed in the inferior vena cava and subsequently released. Serial perfusion lung scintigrams revealed the postembolic distribution of pulmonary blood flow before, during, and after the infusion of isoproterenol at 2.2 μg/min. Isoproterenol failed to restore perfusion to embolically occluded regions. When reperfusion occurred it was attributable to clot resolution. Gas exchange and hemodynamic measurements obtained in seven thromboembolized animals showed no scan evidence of reperfusion during the isoproterenol infusion. After embolization, cardiac output increased from 1.7 to 2.6 liter/min (p 2 from 38.0 to 45.3 mm Hg (p 2 to 50.7 mm Hg, along with a decrease in pulmonary vascular resistance from the postembolic mean of 448 to 246 dynes.sec.cm -5 (p < 0.05). Perfusion defects following acute pulmonary thromboembolization are not altered by the infusion of the potent pulmonary vasodilator, isoproterenol. Infusion of this drug following thromboembolization may have potential therapeutic benefit by reducing pulmonary vascular resistance, increasing cardiac output, and elevating the mixed-venous oxygen tension

Common-path Fourier domain optical coherence tomography of irradiated human skin and ventilated isolated rabbit lungs

Science.gov (United States)

Popp, A.; Wendel, M.; Knels, L.; Knuschke, P.; Mehner, M.; Koch, T.; Boller, D.; Koch, P.; Koch, E.

2005-08-01

A compact common path Fourier domain optical coherence tomography (FD-OCT) system based on a broadband superluminescence diode is used for biomedical imaging. The epidermal thickening of human skin after exposure to ultraviolet radiation is measured to proof the feasibility of FD-OCT for future substitution of invasive biopsies in a long term study on natural UV skin protection. The FD-OCT system is also used for imaging lung parenchyma. FD-OCT images of a formalin fixated lung show the same alveolar structure as scanning electron microscopy images. In the ventilated and blood-free perfused isolated rabbit lung FD-OCT is used for real-time cross-sectional image capture of alveolar mechanics throughout tidal ventilation. The alveolar mechanics changing from alternating recruitment-derecruitment at zero positive end-expiratory pressure (PEEP) to persistent recruitment after applying a PEEP of 5 cm H2O is observed in the OCT images.

Intraoperative mechanical ventilation strategies in patients undergoing one-lung ventilation: a meta-analysis.

Science.gov (United States)

Liu, Zhen; Liu, Xiaowen; Huang, Yuguang; Zhao, Jing

2016-01-01

Postoperative pulmonary complications (PPCs), which are not uncommon in one-lung ventilation, are among the main causes of postoperative death after lung surgery. Intra-operative ventilation strategies can influence the incidence of PPCs. High tidal volume (V T) and increased airway pressure may lead to lung injury, while pressure-controlled ventilation and lung-protective strategies with low V T may have protective effects against lung injury. In this meta-analysis, we aim to investigate the effects of different ventilation strategies, including pressure-controlled ventilation (PCV), volume-controlled ventilation (VCV), protective ventilation (PV) and conventional ventilation (CV), on PPCs in patients undergoing one-lung ventilation. We hypothesize that both PV with low V T and PCV have protective effects against PPCs in one-lung ventilation. A systematic search (PubMed, EMBASE, the Cochrane Library, and Ovid MEDLINE; in May 2015) was performed for randomized trials comparing PCV with VCV or comparing PV with CV in one-lung ventilation. Methodological quality was evaluated using the Cochrane tool for risk. The primary outcome was the incidence of PPCs. The secondary outcomes included the length of hospital stay, intraoperative plateau airway pressure (Pplateau), oxygen index (PaO2/FiO2) and mean arterial pressure (MAP). In this meta-analysis, 11 studies (436 patients) comparing PCV with VCV and 11 studies (657 patients) comparing PV with CV were included. Compared to CV, PV decreased the incidence of PPCs (OR 0.29; 95 % CI 0.15-0.57; P < 0.01) and intraoperative Pplateau (MD -3.75; 95 % CI -5.74 to -1.76; P < 0.01) but had no significant influence on the length of hospital stay or MAP. Compared to VCV, PCV decreased intraoperative Pplateau (MD -1.46; 95 % CI -2.54 to -0.34; P = 0.01) but had no significant influence on PPCs, PaO2/FiO2 or MAP. PV with low V T was associated with the reduced incidence of PPCs compared to CV. However, PCV and VCV had similar

Mathematics of Ventilator-induced Lung Injury.

Science.gov (United States)

Rahaman, Ubaidur

2017-08-01

Ventilator-induced lung injury (VILI) results from mechanical disruption of blood-gas barrier and consequent edema and releases of inflammatory mediators. A transpulmonary pressure (P L ) of 17 cmH 2 O increases baby lung volume to its anatomical limit, predisposing to VILI. Viscoelastic property of lung makes pulmonary mechanics time dependent so that stress (P L ) increases with respiratory rate. Alveolar inhomogeneity in acute respiratory distress syndrome acts as a stress riser, multiplying global stress at regional level experienced by baby lung. Limitation of stress (P L ) rather than strain (tidal volume [V T ]) is the safe strategy of mechanical ventilation to prevent VILI. Driving pressure is the noninvasive surrogate of lung strain, but its relations to P L is dependent on the chest wall compliance. Determinants of lung stress (V T , driving pressure, positive end-expiratory pressure, and inspiratory flow) can be quantified in terms of mechanical power, and a safe threshold can be determined, which can be used in decision-making between safe mechanical ventilation and extracorporeal lung support.

Gill and lung ventilation responses to steady-state aquatic hypoxia and hyperoxia in the bullfrog tadpole.

Science.gov (United States)

West, N H; Burggren, W W

1982-02-01

Gill ventilation frequency (fG), the pressure amplitude (PBC) and stroke volume (VS) of buccal ventilation cycles, the frequency of air breaths (fL), water flow over the gills (VW), gill oxygen uptake (MGO2), oxygen utilization (U), and heart frequency (fH) have been measured in unanaesthetized, air breathing Rana catesbeiana tadpoles (stage XVI-XIX). The animals were unrestrained except for ECG leads or cannulae, and were able to surface voluntarily for air breathing. They were subjected to aquatic normoxia, hyperoxia and three levels of aquatic hypoxia, and their respiratory responses recorded in the steady state. The experiments were performed at 20 +/- 0.5 degrees C. In hyperoxia there was an absence of air breathing, and fG, PBC and VW fell from the normoxic values, while U increased, resulting in no significant change in MGO2. Animals in normoxia showed a very low fL which increased in progressively more hypoxic states. VW increased from the normoxic value in mild hypoxia (PO2 = 96 +/- 2 mm Hg), but fell, associated with a reduction in PBC, in moderate (PO2 = 41 +/- 1 mm Hg) and severe (PO2 = 21 +/- 3 mm Hg) hypoxia in the presence of lung ventilation. Gill MGO2 was not significantly different from the normoxic value in mild hypoxia but fell in moderate hypoxia, while in severe hypoxia oxygen was lost to the ventilating water from the blood perfusing the gills. There was no significant change in fH from the normoxic value in either hypoxia or hyperoxia. These data indicate, that in the bimodally breathing bullfrog tadpole, aquatic PO2 exerts a strong control over both gill and lung ventilation. Furthermore, there is an interaction between gill and lung ventilation such that the onset of a high frequency of lung ventilation in moderate and severe hypoxia promotes a suppression of gill ventilation cycles.

Hot spots on Tc-99m MAA perfusion lung scan

International Nuclear Information System (INIS)

Lim, Seok Tae; Sohn, Myung Hee

2001-01-01

A 61 year-old woman underwent perfusion and inhalation lung scan for the evaluation of pulmonary thromboembolism. Tc-99m MAA perfusion lung scan showed multiple round hot spots in both lung fields. Tc-99m DTPA aerosol inhalation lung scan and chest radiography taken at the same time showed normal findings. A repeated perfusion lung scan taken 24 hours later demonstrated no abnormalities. Hot spots on perfusion lung scan can be caused by microsphere clumping due to faulty injection technique by radioactive embolization from upper extremity thrombophlebitis after injection. Focal hot spots can signify zones of atelectasis, where the hot spots probably represent a failure of hypoxic vasoconstriction. Artifactual hot spots due to microsphere clumping usually appear to be round and in peripheral location, and the lesions due to a loss of hypoxic vasoconstriction usually appear to be hot uptakes having linear borders. Although these artifactual hot spots have been well-known, we rarely encounter them. This report presents a case with artifactual hot spots due to microsphere clumping on Tc-99m MAA perfusion lung scan

Current concepts of protective ventilation during general anaesthesia

NARCIS (Netherlands)

Serpa Neto, Ary; Schultz, Marcus J.; Slutsky, Arthur S.

2015-01-01

Mechanical ventilation with high tidal volumes (VT) has been common practice in operating theatres because this strategy recruits collapsed lung tissue and improves ventilation-perfusion mismatch, thus decreasing the need for high inspired oxygen concentrations. Positive end-expiratory pressure

The lungs

International Nuclear Information System (INIS)

Macey, D.J.; Marshall, R.

1982-01-01

Currently emission tomography of the lungs is only practical for perfusion images with sup(99m)Tc microaggregates and ventilation images with sup(81m)Kr. The following topics are touched on: the rotating gamma camera single photon ECT system, spatial resolution and linearity, resolution in phantom studies, area and volume studies, quantitation studies, with particular reference to the authors' experience of perfusion and ventilation in investigations of pulmonary embolism. (U.K.)

Pulmonary Perfusion Changes as Assessed by Contrast-Enhanced Dual-Energy Computed Tomography after Endoscopic Lung Volume Reduction by Coils.

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Lador, Frédéric; Hachulla, Anne-Lise; Hohn, Olivia; Plojoux, Jérôme; Ronot, Maxime; Montet, Xavier; Soccal, Paola M

2016-01-01

Endoscopic lung volume reduction by coils (LVRC) is a recent treatment approach for severe emphysema. Furthermore, dual-energy computed tomography (DECT) now offers a combined assessment of lung morphology and pulmonary perfusion. The aim of our study was to assess the impact of LVRC on pulmonary perfusion with DECT. Seventeen patients (64.8 ± 6.7 years) underwent LVRC. DECT was performed prior to and after LVRC. For each patient, lung volumes and emphysema quantification were automatically calculated. Then, 6 regions of interest (ROIs) on the iodine perfusion map were drawn in the anterior, mid, and posterior right and left lungs at 4 defined levels. The ROI values were averaged to obtain lung perfusion as assessed by the lung's iodine concentration (CLung, μg·cm-3). The CLung values were normalized using the left atrial iodine concentration (CLA) to take into account differences between successive DECT scans. The 6-min walk distance (6MWD) improved significantly after the procedure (p = 0.0002). No lung volume changes were observed between successive DECT scans for any of the patients (p = 0.32), attesting the same suspended inspiration. After LVRC, the emphysema index was significantly reduced in the treated lung (p = 0.0014). Lung perfusion increased significantly adjacent to the treated areas (CLung/CLA from 3.4 ± 1.7 to 5.6 ± 2.2, p < 0.001) and in the ipsilateral untreated areas (from 4.1 ± 1.4 to 6.6 ± 1.7, p < 0.001), corresponding to a mean 65 and 61% increase in perfusion, respectively. No significant difference was observed in the contralateral upper and lower areas (from 4.4 ± 1.9 to 4.8 ± 2.1, p = 0.273, and from 4.9 ± 2.0 to 5.2 ± 1.7, p = 0.412, respectively). A significant correlation between increased 6MWD and increased perfusion was found (p = 0.0027, R2 = 0.3850). Quantitative analysis based on DECT acquisition revealed that LVRC results in a significant increase in perfusion in the coil-free areas adjacent to the treated ones, as

Can mechanical ventilation strategies reduce chronic lung disease?

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Donn, Steven M; Sinha, Sunil K

2003-12-01

Chronic lung disease (CLD) continues to be a significant complication in newborn infants undergoing mechanical ventilation for respiratory failure. Although the aetiology of CLD is multifactorial, specific factors related to mechanical ventilation, including barotrauma, volutrauma and atelectrauma, have been implicated as important aetiologic mechanisms. This article discusses the ways in which these factors might be manipulated by various mechanical ventilatory strategies to reduce ventilator-induced lung injury. These include continuous positive airway pressure, permissive hypercapnia, patient-triggered ventilation, volume-targeted ventilation, proportional assist ventilation, high-frequency ventilation and real-time monitoring.

Mechanical ventilation using non-injurious ventilation settings causes lung injury in the absence of pre-existing lung injury in healthy mice

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Wolthuis, Esther K; Vlaar, Alexander P J; Choi, Goda; Roelofs, Joris J T H; Juffermans, Nicole P; Schultz, Marcus J

2009-01-01

INTRODUCTION: Mechanical ventilation (MV) may cause ventilator-induced lung injury (VILI). Present models of VILI use exceptionally large tidal volumes, causing gross lung injury and haemodynamic shock. In addition, animals are ventilated for a relative short period of time and only after a

SU-E-J-249: Correlation of Mean Lung Ventilation Value with Ratio of Total Lung Volumes

International Nuclear Information System (INIS)

Yu, N; Qu, H; Xia, P

2014-01-01

Purpose: Lung ventilation function measured from 4D-CT and from breathing correlated CT images is a novel concept to incorporate the lung physiologic function into treatment planning of radiotherapy. The calculated ventilation functions may vary from different breathing patterns, affecting evaluation of the treatment plans. The purpose of this study is to correlate the mean lung ventilation value with the ratio of the total lung volumes obtained from the relevant CTs. Methods: A ventilation map was calculated from the variations of voxel-to-voxel CT densities from two breathing phases from either 4D-CT or breathing correlated CTs. An open source image registration tool of Plastimatch was used to deform the inhale phase images to the exhale phase images. To calculate the ventilation map inside lung, the whole lung was delineated and the tissue outside the lung was masked out. With a software tool developed in house, the 3D ventilation map was then converted in the DICOM format associated with the planning CT images. The ventilation map was analyzed on a clinical workstation. To correlate ventilation map thus calculated with lung volume change, the total lung volume change was compared the mean ventilation from our method. Results: Twenty two patients who underwent stereotactic body irradiation for lung cancer was selected for this retrospective study. For this group of patients, the ratio of lung volumes for the inhale (Vin ) and exhale phase (Vex ) was shown to be linearly related to the mean of the local ventilation (Vent), Vin/Vex=1.+0.49*Vent (R2=0.93, p<0.01). Conclusion: The total lung volume change is highly correlated with the mean of local ventilation. The mean of local ventilation may be useful to assess the patient's lung capacity

Protective lung ventilation in operating room: a systematic review.

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Futier, E; Constantin, J M; Jaber, S

2014-06-01

Postoperative pulmonary and extrapulmonary complications adversely affect clinical outcomes and healthcare utilization, so that prevention has become a measure of the quality of perioperative care. Mechanical ventilation is an essential support therapy to maintain adequate gas exchange during general anesthesia for surgery. Mechanical ventilation using high tidal volume (VT) (between 10 and 15 mL/kg) has been historically encouraged to prevent hypoxemia and atelectasis formation in anesthetized patients undergoing abdominal and thoracic surgery. However, there is accumulating evidence from both experimental and clinical studies that mechanical ventilation, especially the use of high VT and plateau pressure, may potentially aggravate or even initiate lung injury. Ventilator-associated lung injury can result from cyclic alveolar overdistension of non-dependent lung tissue, and repetitive opening and closing of dependent lung tissue resulting in ultrastructural damage at the junction of closed and open alveoli. Lung-protective ventilation, which refers to the use of lower VT and limited plateau pressure to minimize overdistension, and positive end-expiratory pressure to prevent alveolar collapse at end-expiration, was shown to improve outcome in critically ill patients with acute respiratory distress syndrome (ARDS). It has been recently suggested that this approach might also be beneficial in a broader population, especially in critically ill patients without ARDS at the onset of mechanical ventilation. There is, however, little evidence regarding a potential beneficial effect of lung protective ventilation during surgery, especially in patients with healthy lungs. Although surgical patients are frequently exposed to much shorter periods of mechanical ventilation, this is an important gap in knowledge given the number of patients receiving mechanical ventilation in the operating room. This review developed the benefits of lung protective ventilation during surgery

Mechanical ventilation using non-injurious ventilation settings causes lung injury in the absence of pre-existing lung injury in healthy mice

NARCIS (Netherlands)

Wolthuis, Esther K.; Vlaar, Alexander Pj; Choi, Goda; Roelofs, Joris J. T. H.; Juffermans, Nicole P.; Schultz, Marcus J.

2009-01-01

Introduction Mechanical ventilation (MV) may cause ventilator-induced lung injury (VILI). Present models of VILI use exceptionally large tidal volumes, causing gross lung injury and haemodynamic shock. In addition, animals are ventilated for a relative short period of time and only after a 'priming'

[Alveolar ventilation and recruitment under lung protective ventilation].

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Putensen, Christian; Muders, Thomas; Kreyer, Stefan; Wrigge, Hermann

2008-11-01

Goal of mechanical ventilation is to improve gas exchange and reduce work of breathing without contributing to further lung injury. Besides providing adequate EELV and thereby arterial oxygenation PEEP in addition to a reduction in tidal volume is required to prevent cyclic alveolar collapse and tidal recruitment and hence protective mechanical ventilation. Currently, there is no consensus if and if yes at which price alveolar recruitment with high airway pressures should be intended ("open up the lung"), or if it is more important to reduce the mechanical stress and strain to the lungs as much as possible ("keep the lung closed"). Potential of alveolar recruitment differs from patient to patient but also between lung regions. Potential for recruitment depends probably more on regional lung mechanics - especially on lung elastance - than on the underlying disease. Based on available data neither high PEEP nor other methods used for alveolar recruitment could demonstrate a survival benefit in patients with ARDS. These results may support an individualized titration of PEEP or other manoeuvres used for recruitment taking into consideration the regional effects. Bedside imaging techniques allowing titration of PEEP or other manoeuvres to prevent end-expiratory alveolar collapse (tidal recruitment) and inspiratory overinflation may be a promising development.

Perfusion lung scanning: differentiation of primary from thromboembolic pulmonary hypertension

International Nuclear Information System (INIS)

Lisbona, R.; Kreisman, H.; Novales-Diaz, J.; Derbekyan, V.

1985-01-01

Of eight patients with pulmonary arterial hypertension, final diagnosis established by autopsy or angiography, four had primary hypertension and four hypertension from thromboembolism. The perfusion lung scan was distinctly different in the two groups. The lung scan in primary pulmonary hypertension was associated with nonsegmental, patchy defects of perfusion, while in thromboembolic hypertensives it was characterized by segmental and/or lobar defects of perfusion with or without subsegmental defects. The perfusion lung scan is a valuable, noninvasive study in the evaluation of the patient with pulmonary hypertension of undetermined cause and in the exclusion of occult large-vessel pulmonary thromboembolism

Changes in lung volume and ventilation during surfactant treatment in ventilated preterm infants

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Miedema, Martijn; de Jongh, Frans H.; Frerichs, Inez; van Veenendaal, Mariëtte B.; van Kaam, Anton H.

2011-01-01

The immediate and regional effects of exogenous surfactant in open lung high-frequency oscillatory ventilated (HFOV) preterm infants are unknown. To assess regional changes in lung volume, mechanics, and ventilation during and after surfactant administration in HFOV preterm infants with respiratory

Comparison between conventional and protective one-lung ventilation for ventilator-assisted thoracic surgery.

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Ahn, H J; Kim, J A; Yang, M; Shim, W S; Park, K J; Lee, J J

2012-09-01

Recent papers suggest protective ventilation (PV) as a primary ventilation strategy during one-lung ventilation (OLV) to reduce postoperative pulmonary morbidity. However, data regarding the advantage of the PV strategy in patients with normal preoperative pulmonary function are inconsistent, especially in the case of minimally invasive thoracic surgery. Therefore we compared conventional OLV (VT 10 ml/kg, FiO2 1.0, zero PEEP) to protective OLV (VT 6 ml/kg, FiO2 0.5, PEEP 5 cmH2O) in patients with normal preoperative pulmonary function tests undergoing video-assisted thoracic surgery. Oxygenation, respiratory mechanics, plasma interleukin-6 and malondialdehyde levels were measured at baseline, 15 and 60 minutes after OLV and 15 minutes after restoration of two-lung ventilation. PaO2 and PaO2/FiO2 were higher in conventional OLV than in protective OLV (PProtective ventilation did not provide advantages over conventional ventilation for video-assisted thoracic surgery in this group of patients with normal lung function.

Lung protective mechanical ventilation and two year survival in patients with acute lung injury: prospective cohort study.

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Needham, Dale M; Colantuoni, Elizabeth; Mendez-Tellez, Pedro A; Dinglas, Victor D; Sevransky, Jonathan E; Dennison Himmelfarb, Cheryl R; Desai, Sanjay V; Shanholtz, Carl; Brower, Roy G; Pronovost, Peter J

2012-04-05

To evaluate the association of volume limited and pressure limited (lung protective) mechanical ventilation with two year survival in patients with acute lung injury. Prospective cohort study. 13 intensive care units at four hospitals in Baltimore, Maryland, USA. 485 consecutive mechanically ventilated patients with acute lung injury. Two year survival after onset of acute lung injury. 485 patients contributed data for 6240 eligible ventilator settings, as measured twice daily (median of eight eligible ventilator settings per patient; 41% of which adhered to lung protective ventilation). Of these patients, 311 (64%) died within two years. After adjusting for the total duration of ventilation and other relevant covariates, each additional ventilator setting adherent to lung protective ventilation was associated with a 3% decrease in the risk of mortality over two years (hazard ratio 0.97, 95% confidence interval 0.95 to 0.99, P=0.002). Compared with no adherence, the estimated absolute risk reduction in two year mortality for a prototypical patient with 50% adherence to lung protective ventilation was 4.0% (0.8% to 7.2%, P=0.012) and with 100% adherence was 7.8% (1.6% to 14.0%, P=0.011). Lung protective mechanical ventilation was associated with a substantial long term survival benefit for patients with acute lung injury. Greater use of lung protective ventilation in routine clinical practice could reduce long term mortality in patients with acute lung injury. Clinicaltrials.gov NCT00300248.

Prediction of residual lung function after lung surgery, and examination of blood perfusion in the pre- and postoperative lung using three-dimensional SPECT

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Shimatani, Shinji [Toho Univ., Tokyo (Japan). School of Medicine

2001-01-01

In order to predict postoperative pulmonary function after lung surgery, preoperative {sup 99m}Tc-macroaggregated albumin (MAA) lung perfusion scans with single-photon emission computed tomography (SPECT) were performed. Spirometry was also performed before and 4-6 months after surgery in 40 patients. In addition, changes in blood perfusion in the pre- and postoperative lung were examined by postoperative lung perfusion scans in 18 of the 40 patients. We measured the three-dimensional (3-D) imaging volume of the operative and contralateral lungs using the volumes rendering method at blood perfusion thresholds of 20, 50 and 75%, utilizing {sup 99m}Tc-MAA lung perfusion, and predicted pulmonary function by means of the measured volumes. We examined the correlation between predicted and the measured values of postoperative pulmonary function, forced vital capacity (FVC) and forced expiratory volume in one second (FEV{sub 1.0}). The correlation between FEV{sub 1.0} predicted by SPECT (threshold 50%) and measured postoperative lung function resembled that between lung function predicted by the standard planar method and measured FEV{sub 1.0} in the lobectomy group. We then examined the ratios of both pre- and postoperative blood perfusion volumes obtained using 3-D imaging at lung perfusion threshold ranges of 10% each (PV20-29, PV30-39) to pre- and postoperative total perfusion (PV20-100). In the lobectomy group, the postoperative PV20-29/PV20-100 value was significantly higher for the operative side lung than the preoperative PV20-29/PV20-100 value, and the postoperative PV50-59, 60-69, 70-79, 80-89 and 90-100/PV20-100 values were significantly lower than the respective preoperative values. However, in the contralateral lung, the respective pre- and postoperative PV/PV20-100 values were almost identical. These findings suggest that the rate of low blood perfusion increased while the rate of middle to high perfusion decreased in the lobectomy group in the operative

"Open lung ventilation optimizes pulmonary function during lung surgery".

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Downs, John B; Robinson, Lary A; Steighner, Michael L; Thrush, David; Reich, Richard R; Räsänen, Jukka O

2014-12-01

We evaluated an "open lung" ventilation (OV) strategy using low tidal volumes, low respiratory rate, low FiO2, and high continuous positive airway pressure in patients undergoing major lung resections. In this phase I pilot study, twelve consecutive patients were anesthetized using conventional ventilator settings (CV) and then OV strategy during which oxygenation and lung compliance were noted. Subsequently, a lung resection was performed. Data were collected during both modes of ventilation in each patient, with each patient acting as his own control. The postoperative course was monitored for complications. Twelve patients underwent open thoracotomies for seven lobectomies and five segmentectomies. The OV strategy provided consistent one-lung anesthesia and improved static compliance (40 ± 7 versus 25 ± 4 mL/cm H2O, P = 0.002) with airway pressures similar to CV. Postresection oxygenation (SpO2/FiO2) was better during OV (433 ± 11 versus 386 ± 15, P = 0.008). All postoperative chest x-rays were free of atelectasis or infiltrates. No patient required supplemental oxygen at any time postoperatively or on discharge. The mean hospital stay was 4 ± 1 d. There were no complications or mortality. The OV strategy, previously shown to have benefits during mechanical ventilation of patients with respiratory failure, proved safe and effective in lung resection patients. Because postoperative pulmonary complications may be directly attributable to the anesthetic management, adopting an OV strategy that optimizes lung mechanics and gas exchange may help reduce postoperative problems and improve overall surgical results. A randomized trial is planned to ascertain whether this technique will reduce postoperative pulmonary complications. Copyright © 2014 Elsevier Inc. All rights reserved.

Detection of reactive oxygen species in isolated, perfused lungs by electron spin resonance spectroscopy

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Schudt Christian

2005-07-01

Full Text Available Abstract Background The sources and measurement of reactive oxygen species (ROS in intact organs are largely unresolved. This may be related to methodological problems associated with the techniques currently employed for ROS detection. Electron spin resonance (ESR with spin trapping is a specific method for ROS detection, and may address some these technical problems. Methods We have established a protocol for the measurement of intravascular ROS release from isolated buffer-perfused and ventilated rabbit and mouse lungs, combining lung perfusion with the spin probe l-hydroxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine (CPH and ESR spectroscopy. We then employed this technique to characterize hypoxia-dependent ROS release, with specific attention paid to NADPH oxidase-dependent superoxide formation as a possible vasoconstrictor pathway. Results While perfusing lungs with CPH over a range of inspired oxygen concentrations (1–21 %, the rate of CP• formation exhibited an oxygen-dependence, with a minimum at 2.5 % O2. Addition of superoxide dismutase (SOD to the buffer fluid illustrated that a minor proportion of this intravascular ROS leak was attributable to superoxide. Stimulation of the lungs by injection of phorbol-12-myristate-13-acetate (PMA into the pulmonary artery caused a rapid increase in CP• formation, concomitant with pulmonary vasoconstriction. Both the PMA-induced CPH oxidation and the vasoconstrictor response were largely suppressed by SOD. When the PMA challenge was performed at different oxygen concentrations, maximum superoxide liberation and pulmonary vasoconstriction occurred at 5 % O2. Using a NADPH oxidase inhibitor and NADPH-oxidase deficient mice, we illustrated that the PMA-induced superoxide release was attributable to the stimulation of NADPH oxidases. Conclusion The perfusion of isolated lungs with CPH is suitable for detection of intravascular ROS release by ESR spectroscopy. We employed this technique to

Lung radiopharmaceuticals; Radioformacos pulmonares

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Gonzalez, B M [Instituto Nacional de Pediatroa (Mexico)

1994-12-31

Indication or main clinical use of Lung radiopharmaceuticals is presented and clasification of radiopharmaceuticals as ventilation and perfusion studies. Perfusion radiopharmaceuticals, main controls for administration quality acceptance. Clearence after blood administration and main clinical applications. Ventilation radiopharmaceuticals, gases and aerosols, characteristics of a ideal radioaerosol, techniques of good inhalation procedure, clinical applications. Comparison of several radiopharmaceuticals reflering to retention time as 50% administered dose, percent administered dose at 6 hours post inhalation, blood activity at 30 and 60 minutes post inhalation, initial lung absorbed dose, cumulated activity.Kinetic description of two radiopharmaceuticals, 99mTcDTPA and 99mTc-PYP.

Perioperative lung protective ventilation in obese patients.

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Fernandez-Bustamante, Ana; Hashimoto, Soshi; Serpa Neto, Ary; Moine, Pierre; Vidal Melo, Marcos F; Repine, John E

2015-05-06

The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increasing, and facing these challenges is common in the operating rooms and critical care units worldwide. In this review we summarize the existing literature which supports the following recommendations for the perioperative ventilation in obese patients: (1) the use of protective ventilation with low tidal volumes (approximately 8 mL/kg, calculated based on predicted -not actual- body weight) to avoid volutrauma; (2) a focus on lung recruitment by utilizing PEEP (8-15 cmH2O) in addition to recruitment maneuvers during the intraoperative period, as well as incentivized deep breathing and noninvasive ventilation early in the postoperative period, to avoid atelectasis, hypoxemia and atelectrauma; and (3) a judicious oxygen use (ideally less than 0.8) to avoid hypoxemia but also possible reabsorption atelectasis. Obesity poses an additional challenge for achieving adequate protective ventilation during one-lung ventilation, but different lung isolation techniques have been adequately performed in obese patients by experienced providers. Postoperative efforts should be directed to avoid hypoventilation, atelectasis and hypoxemia. Further studies are needed to better define optimum protective ventilation strategies and analyze their impact on the perioperative outcomes of surgical patients with obesity.

Pulmonary O2 transfer during pulsatile and non-pulsatile perfusion.

Science.gov (United States)

Hauge, A; Nicolaysen, G

1980-07-01

The importance of the perfusion pattern for the oxygen transfer has been examined in isolated rabbit lungs perfused with plasma at constant volume inflow. The lungs were ventilated with constant tidal volume and constant end-expiratory pressure. Following a standardized rise in FIO2 the rate of rise in pulmonary venous PO2 (delta PO2/delta t) was measured during alternately pulsatile and non-pulsatile perfusion in normal lungs and in lungs made edematous by elevation of left atrial pressure. In normal lungs there was no difference in delta PO2/delta t when the two modes of perfusion were compared. In edematous lungs delta PO/delta t was statistically higher during pulsatile perfusion, indicating a beneficial effect of flow- and pressure pulsations, e.g. a better distribution of V/Q ratios throughout the lungs. In a separate series of expts. the advancement of a high O2 front through the airways was measured, and the two perfusion patterns compared. Since no difference was found, we suggest that the phenomenon of "cardiogenic gas mixing" in the airways in vivo is a result of a direct action of the heart on the lungs rather than arterial pulsations.

Comparison of lung protective ventilation strategies in a rabbit model of acute lung injury.

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Rotta, A T; Gunnarsson, B; Fuhrman, B P; Hernan, L J; Steinhorn, D M

2001-11-01

To determine the impact of different protective and nonprotective mechanical ventilation strategies on the degree of pulmonary inflammation, oxidative damage, and hemodynamic stability in a saline lavage model of acute lung injury. A prospective, randomized, controlled, in vivo animal laboratory study. Animal research facility of a health sciences university. Forty-six New Zealand White rabbits. Mature rabbits were instrumented with a tracheostomy and vascular catheters. Lavage-injured rabbits were randomized to receive conventional ventilation with either a) low peak end-expiratory pressure (PEEP; tidal volume of 10 mL/kg, PEEP of 2 cm H2O); b) high PEEP (tidal volume of 10 mL/kg, PEEP of 10 cm H2O); c) low tidal volume with PEEP above Pflex (open lung strategy, tidal volume of 6 mL/kg, PEEP set 2 cm H2O > Pflex); or d) high-frequency oscillatory ventilation. Animals were ventilated for 4 hrs. Lung lavage fluid and tissue samples were obtained immediately after animals were killed. Lung lavage fluid was assayed for measurements of total protein, elastase activity, tumor necrosis factor-alpha, and malondialdehyde. Lung tissue homogenates were assayed for measurements of myeloperoxidase activity and malondialdehyde. The need for inotropic support was recorded. Animals that received a lung protective strategy (open lung or high-frequency oscillatory ventilation) exhibited more favorable oxygenation and lung mechanics compared with the low PEEP and high PEEP groups. Animals ventilated by a lung protective strategy also showed attenuation of inflammation (reduced tracheal fluid protein, tracheal fluid elastase, tracheal fluid tumor necrosis factor-alpha, and pulmonary leukostasis). Animals treated with high-frequency oscillatory ventilation had attenuated oxidative injury to the lung and greater hemodynamic stability compared with the other experimental groups. Both lung protective strategies were associated with improved oxygenation, attenuated inflammation, and

Positive pressure ventilation with the open lung concept optimizes gas exchange and reduces ventilator-induced lung injury in newborn piglets

NARCIS (Netherlands)

van Kaam, Anton H.; de Jaegere, Anne; Haitsma, Jack J.; van Aalderen, Wim M.; Kok, Joke H.; Lachmann, Burkhard

2003-01-01

Previous studies demonstrated that high-frequency oscillatory ventilation using the open lung concept (OLC resulted in superior gas exchange and a reduction in ventilator-induced lung injury (VILI). We hypothesized that these beneficial effects could also be achieved by applying the OLC during

Role of combined perfusion/ventilation scanning in diagnosis of pulmonary embolism

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Moustafa, H; Elhaddad, SH; Wageeh, SH; Samy, A; Abdo, S [Nuclear medicine and radiology department, faculty of medicine and Cairo university, Cairo, (Egypt)

1995-10-01

This study was conducted on 200 patients with suspected pulmonary embolism. Their age ranged 9-74 years with a mean age of 41.9+14.6 years.The commonest symptoms were dyspnea; chest pain and haemoptysis in 67.5%,49.5% and 14.5% respectively, whereas the main signs were tachycardia in 64.5% followed by rales and oedema of lower limbs in 28.5% and 14% respectively. Cardiac diseases were presenting the main risk factors in 47% followed by DVT, surgery, COLD in 24%,10% and 9.5% respectively. perfusion lung scan was normal in 27.5%, whereas low, intermediate and high probability scans were seen in 7%,23.5% and 42% respectively. The addition of ventilation scan, change probability of perfusion defects into 18.5%,19% and 31.5% in low, intermediate and high probability scans respectively. In addition 3.5% of patient diagnosed as non- embolic disease. There was significant correlation with increase number of symptoms and signs in relation to scan probability in both whole group and high probability group. Also, the incidence of pulmonary embolism appear to be additive with increase number of risk factors in the group of high probability scans. 3 figs., 3 tabs.

Role of combined perfusion/ventilation scanning in diagnosis of pulmonary embolism

International Nuclear Information System (INIS)

Moustafa, H.; Elhaddad, SH.; Wageeh, SH.; Samy, A.; Abdo, S.

1995-01-01

This study was conducted on 200 patients with suspected pulmonary embolism. Their age ranged 9-74 years with a mean age of 41.9+14.6 years.The commonest symptoms were dyspnea; chest pain and haemoptysis in 67.5%,49.5% and 14.5% respectively, whereas the main signs were tachycardia in 64.5% followed by rales and oedema of lower limbs in 28.5% and 14% respectively. Cardiac diseases were presenting the main risk factors in 47% followed by DVT, surgery, COLD in 24%,10% and 9.5% respectively. perfusion lung scan was normal in 27.5%, whereas low, intermediate and high probability scans were seen in 7%,23.5% and 42% respectively. The addition of ventilation scan, change probability of perfusion defects into 18.5%,19% and 31.5% in low, intermediate and high probability scans respectively. In addition 3.5% of patient diagnosed as non- embolic disease. There was significant correlation with increase number of symptoms and signs in relation to scan probability in both whole group and high probability group. Also, the incidence of pulmonary embolism appear to be additive with increase number of risk factors in the group of high probability scans. 3 figs., 3 tabs

Automatic lung segmentation in functional SPECT images using active shape models trained on reference lung shapes from CT.

Science.gov (United States)

Cheimariotis, Grigorios-Aris; Al-Mashat, Mariam; Haris, Kostas; Aletras, Anthony H; Jögi, Jonas; Bajc, Marika; Maglaveras, Nicolaos; Heiberg, Einar

2018-02-01

Image segmentation is an essential step in quantifying the extent of reduced or absent lung function. The aim of this study is to develop and validate a new tool for automatic segmentation of lungs in ventilation and perfusion SPECT images and compare automatic and manual SPECT lung segmentations with reference computed tomography (CT) volumes. A total of 77 subjects (69 patients with obstructive lung disease, and 8 subjects without apparent perfusion of ventilation loss) performed low-dose CT followed by ventilation/perfusion (V/P) SPECT examination in a hybrid gamma camera system. In the training phase, lung shapes from the 57 anatomical low-dose CT images were used to construct two active shape models (right lung and left lung) which were then used for image segmentation. The algorithm was validated in 20 patients, comparing its results to reference delineation of corresponding CT images, and by comparing automatic segmentation to manual delineations in SPECT images. The Dice coefficient between automatic SPECT delineations and manual SPECT delineations were 0.83 ± 0.04% for the right and 0.82 ± 0.05% for the left lung. There was statistically significant difference between reference volumes from CT and automatic delineations for the right (R = 0.53, p = 0.02) and left lung (R = 0.69, p automatic quantification of wide range of measurements.

Lung-Protective Ventilation Strategies for Relief from Ventilator-Associated Lung Injury in Patients Undergoing Craniotomy: A Bicenter Randomized, Parallel, and Controlled Trial

Directory of Open Access Journals (Sweden)

Chaoliang Tang

2017-01-01

Full Text Available Current evidence indicates that conventional mechanical ventilation often leads to lung inflammatory response and oxidative stress, while lung-protective ventilation (LPV minimizes the risk of ventilator-associated lung injury (VALI. This study evaluated the effects of LPV on relief of pulmonary injury, inflammatory response, and oxidative stress among patients undergoing craniotomy. Sixty patients undergoing craniotomy received either conventional mechanical (12 mL/kg tidal volume [VT] and 0 cm H2O positive end-expiratory pressure [PEEP]; CV group or protective lung (6 mL/kg VT and 10 cm H2O PEEP; PV group ventilation. Hemodynamic variables, lung function indexes, and inflammatory and oxidative stress markers were assessed. The PV group exhibited greater dynamic lung compliance and lower respiratory index than the CV group during surgery (P0.05. Patients receiving LPV during craniotomy exhibited low perioperative inflammatory response, oxidative stress, and VALI.

Closed-loop mechanical ventilation for lung injury: a novel physiological-feedback mode following the principles of the open lung concept.

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Schwaiberger, David; Pickerodt, Philipp A; Pomprapa, Anake; Tjarks, Onno; Kork, Felix; Boemke, Willehad; Francis, Roland C E; Leonhardt, Steffen; Lachmann, Burkhard

2018-06-01

Adherence to low tidal volume (V T ) ventilation and selected positive end-expiratory pressures are low during mechanical ventilation for treatment of the acute respiratory distress syndrome. Using a pig model of severe lung injury, we tested the feasibility and physiological responses to a novel fully closed-loop mechanical ventilation algorithm based on the "open lung" concept. Lung injury was induced by surfactant washout in pigs (n = 8). Animals were ventilated following the principles of the "open lung approach" (OLA) using a fully closed-loop physiological feedback algorithm for mechanical ventilation. Standard gas exchange, respiratory- and hemodynamic parameters were measured. Electrical impedance tomography was used to quantify regional ventilation distribution during mechanical ventilation. Automatized mechanical ventilation provided strict adherence to low V T -ventilation for 6 h in severely lung injured pigs. Using the "open lung" approach, tidal volume delivery required low lung distending pressures, increased recruitment and ventilation of dorsal lung regions and improved arterial blood oxygenation. Physiological feedback closed-loop mechanical ventilation according to the principles of the open lung concept is feasible and provides low tidal volume ventilation without human intervention. Of importance, the "open lung approach"-ventilation improved gas exchange and reduced lung driving pressures by opening atelectasis and shifting of ventilation to dorsal lung regions.

Barotrauma and microvascular injury in lungs of nonadult rabbits: effect of ventilation pattern.

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Peevy, K J; Hernandez, L A; Moise, A A; Parker, J C

1990-06-01

To study the pulmonary microvascular injury produced by ventilation barotrauma, the isolated perfused lungs of 4 to 6-wk-old New Zealand white rabbits were ventilated by one of the following methods: peak inspiratory pressure (PIP) 23 cm H2O, gas flow rate 1.1 L/min (group 1); PIP 27 cm H2O, gas flow rate 6.9 L/min (group 2); PIP 50 cm H2O, gas flow rate 1.9 L/min (group 3); or PIP 53 cm H2O, gas flow rate 8.3 L/min (group 4). Microvascular permeability was assessed using the capillary filtration coefficient (Kfc) before and 5, 30, and 60 min after a 15-min period of ventilation. Baseline Kfc was not significantly different between groups. A significant increase over the baseline Kfc was noted at 60 min in group 2 and in all postventilation Kfc values in groups 3 and 4 (p less than .05). Group 1 Kfc values did not change significantly after ventilation. At all post-ventilation times, values for Kfc were significantly greater in groups 3 and 4 than in group 1 (p less than .05). Group 4 Kfc values were significantly greater than those in group 2 at 5 and 30 min postventilation. These data indicate that high PIP, and to a lesser extent, high gas flow rates cause microvascular injury in the compliant nonadult lung and suggest that the combination of high PIP and high gas flow rates are the most threatening to microvascular integrity.

Uptake of exogenous spermidine by rat lungs perfused in situ

International Nuclear Information System (INIS)

Rannels, D.E.; Addison, J.L.

1987-01-01

Uptake of the polyamine spermidine (SPD) from the pulmonary circulation was characterized by using ventilated rat lungs perfused in situ with Krebs-Henseleit-bicarbonate buffer containing 4.5% bovine serum albumin, 5.6 mM glucose, and 20 amino acids at plasma levels. [ 14 C]SPD was accumulated by the lungs in a time- and concentration-dependent manner. The pathway of SPD uptake exhibited saturation kinetics with an apparent K/sub m/ in the range of 1 μM and a V/sub max/ of 450-540 pmol/g lung min. SPD uptake was inhibited by the naturally occurring polyamines putrescine and spermine (SPM) and by the inhibitor of polyamine synthesis, methyglyoxal bis(guanylhydrazone) (MGBG). Inhibition of SPD uptake by SPM followed competitive kinetics; although MGBG was also a competitive inhibitor of SPD uptake, MGBG was less effective than SPM. These observations indicate that SPD is taken up from the pulmonary circulation by a carrier-mediated pathway that is inhibited by other natural polyamines and by MGBG and exhibits by other natural polyamines and by MGBG and exhibits substrate affinity in the range of plasma SPD concentrations

Uptake of exogenous spermidine by rat lungs perfused in situ

Energy Technology Data Exchange (ETDEWEB)

Rannels, D.E.; Addison, J.L.

1987-01-01

Uptake of the polyamine spermidine (SPD) from the pulmonary circulation was characterized by using ventilated rat lungs perfused in situ with Krebs-Henseleit-bicarbonate buffer containing 4.5% bovine serum albumin, 5.6 mM glucose, and 20 amino acids at plasma levels. (/sup 14/C)SPD was accumulated by the lungs in a time- and concentration-dependent manner. The pathway of SPD uptake exhibited saturation kinetics with an apparent K/sub m/ in the range of 1 ..mu..M and a V/sub max/ of 450-540 pmol/g lung min. SPD uptake was inhibited by the naturally occurring polyamines putrescine and spermine (SPM) and by the inhibitor of polyamine synthesis, methyglyoxal bis(guanylhydrazone) (MGBG). Inhibition of SPD uptake by SPM followed competitive kinetics; although MGBG was also a competitive inhibitor of SPD uptake, MGBG was less effective than SPM. These observations indicate that SPD is taken up from the pulmonary circulation by a carrier-mediated pathway that is inhibited by other natural polyamines and by MGBG and exhibits by other natural polyamines and by MGBG and exhibits substrate affinity in the range of plasma SPD concentrations.

Lung-protective perioperative mechanical ventilation

NARCIS (Netherlands)

Hemmes, S.N.T.

2015-01-01

Intraoperative ventilation has the potential to cause lung injury and possibly increase risk of pulmonary complications after surgery. Use of large tidal volumes could cause overdistension of lung tissue, which can be aggravated by too high levels of positive end-expiratory pressure (PEEP). Too low

Ventilator induced lung injury (VILI) in acute respiratory distress ...

African Journals Online (AJOL)

The lung protective ventilation strategy- Low tidal volume ventilation has shown some reduction in mortality in patients with ARDS but mortality is still high in patient with severe ARDS secondary to Pneumocystis jiroveci pneumonia (PJP) despite of lung protective ventilation strategy. In patients with Severe ARDS due to PJP ...

Fuzzy modeling of electrical impedance tomography images of the lungs

International Nuclear Information System (INIS)

Tanaka, Harki; Ortega, Neli Regina Siqueira; Galizia, Mauricio Stanzione; Borges, Joao Batista; Amato, Marcelo Britto Passos

2008-01-01

Objectives: Aiming to improve the anatomical resolution of electrical impedance tomography images, we developed a fuzzy model based on electrical impedance tomography's high temporal resolution and on the functional pulmonary signals of perfusion and ventilation. Introduction: Electrical impedance tomography images carry information about both ventilation and perfusion. However, these images are difficult to interpret because of insufficient anatomical resolution, such that it becomes almost impossible to distinguish the heart from the lungs. Methods: Electrical impedance tomography data from an experimental animal model were collected during normal ventilation and apnoea while an injection of hypertonic saline was administered. The fuzzy model was elaborated in three parts: a modeling of the heart, the pulmonary ventilation map and the pulmonary perfusion map. Image segmentation was performed using a threshold method, and a ventilation/perfusion map was generated. Results: Electrical impedance tomography images treated by the fuzzy model were compared with the hypertonic saline injection method and computed tomography scan images, presenting good results. The average accuracy index was 0.80 when comparing the fuzzy modeled lung maps and the computed tomography scan lung mask. The average ROC curve area comparing a saline injection image and a fuzzy modeled pulmonary perfusion image was 0.77. Discussion: The innovative aspects of our work are the use of temporal information for the delineation of the heart structure and the use of two pulmonary functions for lung structure delineation. However, robustness of the method should be tested for the imaging of abnormal lung conditions. Conclusions: These results showed the adequacy of the fuzzy approach in treating the anatomical resolution uncertainties in electrical impedance tomography images. (author)

To Find a Better Dosimetric Parameter in the Predicting of Radiation-Induced Lung Toxicity Individually: Ventilation, Perfusion or CT based.

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Xiao, Lin-Lin; Yang, Guoren; Chen, Jinhu; Wang, Xiaohui; Wu, Qingwei; Huo, Zongwei; Yu, Qingxi; Yu, Jinming; Yuan, Shuanghu

2017-03-15

This study aimed to find a better dosimetric parameter in predicting of radiation-induced lung toxicity (RILT) in patients with non-small cell lung cancer (NSCLC) individually: ventilation(V), perfusion (Q) or computerized tomography (CT) based. V/Q single-photon emission computerized tomography (SPECT) was performed within 1 week prior to radiotherapy (RT). All V/Q imaging data was integrated into RT planning system, generating functional parameters based on V/Q SPECT. Fifty-seven NSCLC patients were enrolled in this prospective study. Fifteen (26.3%) patients underwent grade ≥2 RILT, the remaining forty-two (73.7%) patients didn't. Q-MLD, Q-V20, V-MLD, V-V20 of functional parameters correlated more significantly with the occurrence of RILT compared to V20, MLD of anatomical parameters (r = 0.630; r = 0.644; r = 0.617; r = 0.651 vs. r = 0.424; r = 0.520 p < 0.05, respectively). In patients with chronic obstructive pulmonary diseases (COPD), V functional parameters reflected significant advantage in predicting RILT; while in patients without COPD, Q functional parameters reflected significant advantage. Analogous results were existed in fractimal analysis of global pulmonary function test (PFT). In patients with central-type NSCLC, V parameters were better than Q parameters; while in patients with peripheral-type NSCLC, the results were inverse. Therefore, this study demonstrated that choosing a suitable dosimetric parameter individually can help us predict RILT accurately.

Radioaerosol lung imaging - history and pharmaceuticals

International Nuclear Information System (INIS)

Isawa, Toyoharu

1994-01-01

The first use of a radioactive tracer to study lung function was made by Knipping and others in 1955. They used radioactive 133 Xe (xenon) gas as an inhalation agent in a patient with lung cancer and found that distal to a tumor no radioactivity was detected indicating no ventilation although chest x-rays appeared as if there was active ventilation. Subsequently with advance in technology a number of radioactive gases such as 81m Kr (krypton) and cyclotron produced 15 O 2 (oxygen), 11 C (carbon) and 13 N 2 (nitrogen) became available to assess regional lung function. The advantages of these gases are manifold, but their utility is mostly limited due to high cost. An alternative to the use of radioactive gases to study regional ventilation is the use of particulate radioactive aerosol. Radioaerosol inhalation lung imaging technique was developed in 1965 almost simultaneously by Taplin and others and Pircher and others just 2 years following Taplin's invention of 131 I-MAA for perfusion lung imaging. Their main aim was to use 131 I-human serum albumin (HSA), and 99m Tc-HSA, 131 I-rose bengal, 197 Hg-chlormerodrin and colloidal 198 Au as agents for radioaerosol generation, and Taplin himself preferred 198 Au colloids for serial studies from economical reasons. Already in 1965, however, Taplin said that the best agent would be 99m Tc-HSA. Pircher used 131 I-HSA aerosol. Taplin already noted at that time that the inhaled aerosol was removed from the lungs mainly by ciliary action and that it was not absorbed either from the lungs or the intestine. Anyway it is noteworthy that the idea of radioaerosol inhalation lung imaging was proposed soon after the advent of perfusion lung imaging. Besides 131 I-HSA and colloidal 198 Au, the following agents have been or are currently being used. The superiority of 99m TC over other radioisotopes used in the past is beyond dispute

Quantitative study on lung volume and lung perfusion using SPECT and CT in thoracal tumors

International Nuclear Information System (INIS)

Beyer-Enke, S.A.; Goerich, J.; Strauss, L.G.

1988-01-01

22 patients with space occupying lesions in the thoracal region were investigated by computer tomography and by perfusion scintigraphy using SPECT. In order to evaluate the CT images quantitatively, the lung volume was determined using approximation method and compared with the perfusion in the SPECT study. For this, anatomically equivalent transaxial SPECT slices had been coordinated to the CT slices. Between the determined lung volumes and the activity in the ocrresponding layers, a statistically significant correlation was found. It could be shown that the stronger perfusion, frequently observed at the right side of the healthy lung, may be explained by an higher volume of the right pulmonary lobe. Whereas in benign displacing processes the relation activity to volume was similar to the one of the healthy lung, a strongly reduced perfusion together with inconspicuous lung volumes became apparent with malignant tumors. In addition to the great morphological evidence of CT and SPECT studies, additional informations regarding the dignity of displacing processes may be derived from the quantitative evaluation of both methods. (orig.) [de

Low-flow venovenous CO₂ removal in association with lung protective ventilation strategy in patients who develop severe progressive respiratory acidosis after lung transplantation.

Science.gov (United States)

Ruberto, F; Bergantino, B; Testa, M C; D'Arena, C; Zullino, V; Congi, P; Paglialunga, S G; Diso, D; Venuta, F; Pugliese, F

2013-09-01

Primary graft dysfunction (PGD) might occur after lung transplantation. In some severe cases, conventional therapies like ventilatory support, administration of inhaled nitric oxide (iNO), and intravenous prostacyclins are not sufficient to provide an adequate gas exchange. The aim of our study was to evaluate the use of a lung protective ventilation strategy associated with a low-flow venovenous CO2 removal treatment to reduce ventilator-associated injury in patients that develop severe PGD after lung transplantation. From January 2009 to January 2011, 3 patients developed PGD within 24 hours after lung transplantation. In addition to conventional medical treatment, including hemodynamic support, iNO and prostaglandin E1 (PGE1), we initiated a ventilatory protective strategy associated with low-flow venovenous CO2 removal treatment (LFVVECCO2R). Hemodynamic and respiratory parameters were assessed at baseline as well as after 3, 12, 24, and 48 hours. No adverse events were registered. Despite decreased baseline elevated pulmonary positive pressures, application of a protective ventilation strategy with LFVVECCO2R reduced PaCO2 and pulmonary infiltrates as well as increased pH values and PaO2/FiO2 ratios. Every patient showed simultaneous improvement of clinical and hemodynamic conditions. They were weaned from mechanical ventilation and extubated after 24 hours after the use of the low-flow venovenous CO2 removal device. The use of LFVVECCO2R together with a protective lung ventilation strategy during the perioperative period of lung transplantation may be a valid clinical strategy for patients with PGD and severe respiratory acidosis occured despite adequate mechanical ventilation. Copyright © 2013 Elsevier Inc. All rights reserved.

Lung imaging in pulmonary disease

International Nuclear Information System (INIS)

Taplin, G.V.; Chopra, S.K.

1976-01-01

Although it has been recognized for several years that chronic obstructive pulmonary disease (COPD) can cause lung perfusion defects which may simulate pulmonary embolism, relatively little use has been made of either the radioxenon or the radioaerosol inhalation lung imaging procedures until the last few years as a means of distinguishing pulmonary embolism (P.E.) from COPD is reported. Recent experience is reported with the use of both of these procedures in comparison with pulmonary function tests for the early detection of COPD in population studies and also in P.E. suspects. Equal emphasis is given to simultaneous aerosol ventilation-perfusion (V/P) imaging in the differential diagnosis of P.E. Finally, this paper is concerned with new developments in regional lung diffusion imaging following the inhalation of radioactive gases and rapidly absorbed radioaerosols. Their experimental basis is presented and their potential clinical applications in pulmonary embolism are discussed. As a result of these investigations, a functional (V/P) diagnosis of pulmonary embolism in patients may be possible in the near future with a sequential radioaerosol inhalation procedure alone

Radioaerosol ventilation imaging in ventilator-dependent patients. Technical considerations

International Nuclear Information System (INIS)

Vezina, W.; Chamberlain, M.; Vinitski, S.; King, M.; Nicholson, R.; Morgan, W.K.

1985-01-01

The differentiation of pulmonary embolism (PE) from regional ventilatory abnormalities accompanied by reduced perfusion requires contemporary perfusion and ventilation studies. Distinguishing these conditions in ventilator-dependent patients is aided by administering a Tc-99m aerosol to characterize regional ventilation, and by performing a conventional Tc-99m MAA perfusion study. The technique uses a simple in-house constructed apparatus. Simple photographic techniques suffice, but computer subtraction of perfusion from the combined perfusion-ventilation image renders interpretation easier if aerosol administration follows perfusion imaging. Multiple defects can be examined in a single study. Excluding normal or near-normal perfusion studies, PE was thought to be present in eight of 16 patients after perfusion imaging alone, but in only one of eight after added aerosol imaging. Angiography confirmed the diagnosis in that patient. Of the eight patients who had abnormal perfusion but were thought unlikely to have PE from the perfusion study alone, two had normal ventilation, and subsequently were shown to have PE by angiography. Because angiography was only performed on patients who were thought to have a high probability of PE on sequential perfusion-ventilation imaging, the true incidence of PE may have been higher. Aerosol ventilation imaging is a useful adjunct to perfusion imaging in patients on ventilators. It requires an efficient delivery system, particularly if aerosol administration follows perfusion imaging, as it does in this study

Nicotinamide exacerbates hypoxemia in ventilator-induced lung injury independent of neutrophil infiltration.

Directory of Open Access Journals (Sweden)

Heather D Jones

Full Text Available Ventilator-induced lung injury is a form of acute lung injury that develops in critically ill patients on mechanical ventilation and has a high degree of mortality. Nicotinamide phosphoribosyltransferase is an enzyme that is highly upregulated in ventilator-induced lung injury and exacerbates the injury when given exogenously. Nicotinamide (vitamin B3 directly inhibits downstream pathways activated by Nicotinamide phosphoribosyltransferase and is protective in other models of acute lung injury.We administered nicotinamide i.p. to mice undergoing mechanical ventilation with high tidal volumes to study the effects of nicotinamide on ventilator-induced lung injury. Measures of injury included oxygen saturations and bronchoalveolar lavage neutrophil counts, protein, and cytokine levels. We also measured expression of nicotinamide phosophoribosyltransferase, and its downstream effectors Sirt1 and Cebpa, Cebpb, Cebpe. We assessed the effect of nicotinamide on the production of nitric oxide during ventilator-induced lung injury. We also studied the effects of ventilator-induced lung injury in mice deficient in C/EBPε.Nicotinamide treatment significantly inhibited neutrophil infiltration into the lungs during ventilator-induced lung injury, but did not affect protein leakage or cytokine production. Surprisingly, mice treated with nicotinamide developed significantly worse hypoxemia during mechanical ventilation. This effect was not linked to increases in nitric oxide production or alterations in expression of Nicotinamide phosphoribosyl transferase, Sirt1, or Cebpa and Cebpb. Cebpe mRNA levels were decreased with either nicotinamide treatment or mechanical ventilation, but mice lacking C/EBPε developed the same degree of hypoxemia and ventilator-induced lung injury as wild-type mice.Nicotinamide treatment during VILI inhibits neutrophil infiltration of the lungs consistent with a strong anti-inflammatory effect, but paradoxically also leads to the

Lung perfusion SPECT in predicting postoperative pulmonary function in lung cancer

International Nuclear Information System (INIS)

Hirose, Yoshiaki; Imaeda, Takeyoshi; Doi, Hidetaka; Kokubo, Mitsuharu; Sakai, Satoshi; Hirose, Hajime

1993-01-01

The aim of this prospective study is to evaluate the availability of preoperative perfusion SPECT in predicting postoperative pulmonary function following resection. Twenty-three patients with lung cancer who were candidates for lobectomy were investigated preoperatively with spirometry, x-ray computed tomography and 99m Tc-macroaggregated albumin SPECT. Their postoperative pulmonary functions were predicted with these examinations. The forced vital capacity and the forced expiratory volume in one second were selected as parameters for overall pulmonary function. The postoperative pulmonary function was predicted by the following formula: Predicted postoperative value=observed preoperative value x precent perfusion of the lung not to be resected. The patients were reinvestigated with spirometry at 3 months and 6 months after lobectomy, and the values obtained were statistically compared with the predicted values. Close relationships were found between predicted and observed forced vital capacity (r=0.87, p<0.001), and predicted and observed forced expiratory volume in one second (r=0.90, p<0.001). The accurate prediction of pulmonary function after lobectomy could be achieved by means of lung perfusion SPECT. (author)

Improved visualization of delayed perfusion in lung MRI

International Nuclear Information System (INIS)

Risse, Frank; Eichinger, Monika; Kauczor, Hans-Ulrich; Semmler, Wolfhard; Puderbach, Michael

2011-01-01

Introduction: The investigation of pulmonary perfusion by three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was proposed recently. Subtraction images are generated for clinical evaluation, but temporal information is lost and perfusion defects might therefore be masked in this process. The aim of this study is to demonstrate a simple analysis strategy and classification for 3D-DCE-MRI perfusion datasets in the lung without omitting the temporal information. Materials and methods: Pulmonary perfusion measurements were performed in patients with different lung diseases using a 1.5 T MR-scanner with a time-resolved 3D-GRE pulse sequence. 25 3D-volumes were acquired after iv-injection of 0.1 mmol/kg KG Gadolinium-DTPA. Three parameters were determined for each pixel: (1) peak enhancement S n,max normalized to the arterial input function to detect regions of reduced perfusion; (2) time between arterial peak enhancement in the large pulmonary artery and tissue peak enhancement τ to visualize regions with delayed bolus onset; and (3) ratio R = S n,max /τ was calculated to visualize impaired perfusion, irrespectively of whether related to reduced or delayed perfusion. Results: A manual selection of peak perfusion images is not required. Five different types of perfusion can be found: (1) normal perfusion; (2) delayed non-reduced perfusion; (3) reduced non-delayed perfusion; (4) reduced and delayed perfusion; and (5) no perfusion. Types II and IV could not be seen in subtraction images since the temporal information is necessary for this purpose. Conclusions: The analysis strategy in this study allows for a simple and observer-independent visualization and classification of impaired perfusion in dynamic contrast-enhanced pulmonary perfusion MRI by using the temporal information of the datasets.

Adaptive Support Ventilation May Deliver Unwanted Respiratory Rate-Tidal Volume Combinations in Patients with Acute Lung Injury Ventilated According to an Open Lung Concept

NARCIS (Netherlands)

Dongelmans, Dave A.; Paulus, Frederique; Veelo, Denise P.; Binnekade, Jan M.; Vroom, Margreeth B.; Schultz, Marcus J.

2011-01-01

Background: With adaptive support ventilation, respiratory rate and tidal volume (V(T)) are a function of the Otis least work of breathing formula. We hypothesized that adaptive support ventilation in an open lung ventilator strategy would deliver higher V(T)s to patients with acute lung injury.

[USE OF PROTECTIVE LUNG VENTILATION REGIMEN IN CARDIAC SURGERY PATIENTS.

Science.gov (United States)

Pshenichniy, T A; Akselrod, B A; Titova, I V; Trekova, N A; Khrustaleva, M V

2017-09-01

In cardiac surgery, protective lung ventilation and/or preventive brdnchoscopy (PB) are able to decrease lung injury effects of cardiopulmonary bypass (CPB) and mechanical ventilation. define lung complication risks, evaluate the effect ofprotective lung ventilation (PLV) on lung functioning, and investigate the feasibility ofpreventive PB in higher pulmonary risk (PR) patients. 66 patients participated in prospective randomized research. Allocation was based on PR and intraoperative mechanical ventilation type. PLV includedfollowing parameters: PCK PIP - up to 20 cm H20, Vt - 6 ml/ kg of PBW, PEEP - 5-10 cm H20, IE ratio - 1:1.5-1:1, EtCO2 - 35-42 mm Hg, FiO2 - 45-60%, lung ventilation during CPB, alveolar recruitment. Four groups were formed: A - higher PR plus PLV- B - higher PR plus conventional LV (CLV), C - lower PR plus PLV- D - lower PR plus CLV PIP PEEP dynamic compliance, p/f ratio and intrapulmonary shunt (Qs/Qt) were recorded. Seventeen patients of group A underwent PB. Advanced dynamic compliance, higher p/f ratio and lower Qs/Qt were seen in group A, in comparison with group B (pProtective lung ventilation improves lung biomechanics and oxygenating function in higher risk patients and decreases intrapulmonary shunt fraction in higher and lower risk patients. Addictive preventive bronchoscopy can be successfully used in higher risk patients.

Open-lung protective ventilation with pressure control ventilation, high-frequency oscillation, and intratracheal pulmonary ventilation results in similar gas exchange, hemodynamics, and lung mechanics.

Science.gov (United States)

Sedeek, Khaled A; Takeuchi, Muneyuki; Suchodolski, Klaudiusz; Vargas, Sara O; Shimaoka, Motomu; Schnitzer, Jay J; Kacmarek, Robert M

2003-11-01

Pressure control ventilation (PCV), high-frequency oscillation (HFO), and intratracheal pulmonary ventilation (ITPV) may all be used to provide lung protective ventilation in acute respiratory distress syndrome, but the specific approach that is optimal remains controversial. Saline lavage was used to produce acute respiratory distress syndrome in 21 sheep randomly assigned to receive PCV, HFO, or ITPV as follows: positive end-expiratory pressure (PCV and ITPV) and mean airway pressure (HFO) were set in a pressure-decreasing manner after lung recruitment that achieved a ratio of Pao2/Fio2 > 400 mmHg. Respiratory rates were 30 breaths/min, 120 breaths/min, and 8 Hz, respectively, for PCV, ITPV, and HFO. Eucapnia was targeted with peak carinal pressure of no more than 35 cm H2O. Animals were then ventilated for 4 h. There were no differences among groups in gas exchange, lung mechanics, or hemodynamics. Tidal volume (PCV, 8.9 +/- 2.1 ml/kg; ITPV, 2.7 +/- 0.8 ml/kg; HFO, approximately 2.0 ml/kg) and peak carinal pressure (PCV, 30.6 +/- 2.6 cm H2O; ITPV, 22.3 +/- 4.8 cm H2O; HFO, approximately 24.3 cm H2O) were higher in PCV. Pilot histologic data showed greater interstitial hemorrhage and alveolar septal expansion in PCV than in HFO or ITPV. These data indicate that HFO, ITPV, and PCV when applied with an open-lung protective ventilatory strategy results in the same gas exchange, lung mechanics, and hemodynamic response, but pilot data indicate that lung injury may be greater with PCV.

Volume-Targeted Ventilation in the Neonate: Benchmarking Ventilators on an Active Lung Model.

Science.gov (United States)

Krieger, Tobias J; Wald, Martin

2017-03-01

Mechanically ventilated neonates have been observed to receive substantially different ventilation after switching ventilator models, despite identical ventilator settings. This study aims at establishing the range of output variability among 10 neonatal ventilators under various breathing conditions. Relative benchmarking test of 10 neonatal ventilators on an active neonatal lung model. Neonatal ICU. Ten current neonatal ventilators. Ventilators were set identically to flow-triggered, synchronized, volume-targeted, pressure-controlled, continuous mandatory ventilation and connected to a neonatal lung model. The latter was configured to simulate three patients (500, 1,500, and 3,500 g) in three breathing modes each (passive breathing, constant active breathing, and variable active breathing). Averaged across all weight conditions, the included ventilators delivered between 86% and 110% of the target tidal volume in the passive mode, between 88% and 126% during constant active breathing, and between 86% and 120% under variable active breathing. The largest relative deviation occurred during the 500 g constant active condition, where the highest output machine produced 147% of the tidal volume of the lowest output machine. All machines deviate significantly in volume output and ventilation regulation. These differences depend on ventilation type, respiratory force, and patient behavior, preventing the creation of a simple conversion table between ventilator models. Universal neonatal tidal volume targets for mechanical ventilation cannot be transferred from one ventilator to another without considering necessary adjustments.

Effects of Constant Flow vs. Constant Pressure Perfusion on Fluid Filtration in Severe Hypothermic Isolated Blood-Perfused Rat Lungs.

Science.gov (United States)

Halsøy, Kathrine; Kondratiev, Timofey; Tveita, Torkjel; Bjertnaes, Lars J

2016-01-01

Victims of severe accidental hypothermia are prone to fluid extravasation but rarely develop lung edema. We hypothesize that combined hypothermia-induced increase in pulmonary vascular resistance (PVR) and a concomitant fall in cardiac output protect the lungs against edema development. Our aim was to explore in hypothermic-isolated blood-perfused rat lungs whether perfusion at constant pressure influences fluid filtration differently from perfusion at constant flow. Isolated blood-perfused rat lungs were hanging freely in a weight transducer for measuring weight changes (ΔW). Fluid filtration coefficient (Kfc), was determined by transiently elevating left atrial pressure (Pla) by 5.8 mmHg two times each during normothermia (37°C) and during hypothermia (15°C). The lung preparations were randomized to two groups. One group was perfused with constant flow (Constant flow group) and the other group with constant pulmonary artery pressure (Constant PPA group). Microvascular pressure (Pmv) was determined before and during elevation of Pla (ΔPmv) by means of the double occlusion technique. Kfc was calculated with the formula Kfc = ΔW/ΔPmv/min. All Kfc values were normalized to predicted lung weight (P LW ), which was based on body weight (BW) according to the formula: P LW  = 0.0053 BW - 0.48 and presented as Kfc PLW in mg/min/mmHg/g. At cessation, bronchoalveolar lavage (BAL) fluid/perfusate protein concentration (B/P) ratio was determined photometrically. Data were analyzed with parametric or non-parametric tests as appropriate. p  Kfc PLW and B/P ratio increased significantly by more than 10-fold during hypothermia concerted by visible signs of edema in the trachea. Hemoglobin and hematocrit increased within the Constant flow group and between the groups at cessation of the experiments. In hypothermic rat lungs perfused at constant flow, fluid filtration coefficient per gram P LW and B/P ratio increased more than 10-fold concerted by increased

Ventilation/perfusion SPECT in chronic obstructive pulmonary disease: an evaluation by reference to symptoms, spirometric lung function and emphysema, as assessed with HRCT

Energy Technology Data Exchange (ETDEWEB)

Joegi, Jonas; Bajc, Marika [Lund University, Skaane University Hospital, Department of Clinical Physiology, Institution of Clinical Sciences, Lund (Sweden); Ekberg, Marie [Lund University, Skaane University Hospital, Department of Respiratory Medicine and Allergology, Institution of Clinical Sciences, Lund (Sweden); Jonson, Bjoern [Lund University, Department of Clinical Physiology, Institution of Clinical Sciences, Lund (Sweden); Bozovic, Gracijela [Lund University, Skaane University Hospital, Department of Radiology, Institution of Clinical Sciences, Lund (Sweden)

2011-07-15

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation which is not fully reversible. Despite the heterogeneity of COPD, its diagnosis and staging is currently based solely on forced expiratory volume in 1 s (FEV{sub 1}). FEV{sub 1} does not explain the underlying pathophysiology of airflow limitation. The relationship between FEV{sub 1}, symptoms and emphysema extent is weak. Better diagnostic tools are needed to define COPD. Tomographic lung scintigraphy [ventilation/perfusion single photon emission tomography (V/P SPECT)] visualizes regional V and P. In COPD, relations between V/P SPECT, spirometry, high-resolution computed tomography (HRCT) and symptoms have been insufficiently studied. The aim of this study was to investigate how lung function imaging and obstructive disease grading undertaken using V/P SPECT correlate with symptoms, spirometric lung function and degree of emphysema assessed with HRCT in patients with COPD. Thirty patients with stable COPD were evaluated with the Medical Research Council dyspnoea questionnaire (MRC) and the clinical COPD questionnaire (CCQ). Spirometry was performed. The extent of emphysema was assessed using HRCT. V/P SPECT was used to assess V/P patterns, total reduction in lung function and degree of obstructive disease. The total reduction in lung function and degree of obstructive disease, assessed with V/P SPECT, significantly correlated with emphysema extent (r = 0.66-0.69, p < 0.0001) and spirometric lung function (r = 0.62-0.74, p < 0.0005). The correlation between emphysema extent and spirometric lung function was weaker. No correlation between MRC, CCQ and objective measurements was found. V/P SPECT is sensitive to early changes in COPD. V/P SPECT also has the possibility to identify comorbid disease. V/P SPECT findings show a significant correlation with emphysema extent and spirometric lung function. We therefore recommend that scintigraphic signs of COPD, whenever found, should be

Ventilation/perfusion SPECT in chronic obstructive pulmonary disease: an evaluation by reference to symptoms, spirometric lung function and emphysema, as assessed with HRCT

International Nuclear Information System (INIS)

Joegi, Jonas; Bajc, Marika; Ekberg, Marie; Jonson, Bjoern; Bozovic, Gracijela

2011-01-01

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation which is not fully reversible. Despite the heterogeneity of COPD, its diagnosis and staging is currently based solely on forced expiratory volume in 1 s (FEV 1 ). FEV 1 does not explain the underlying pathophysiology of airflow limitation. The relationship between FEV 1 , symptoms and emphysema extent is weak. Better diagnostic tools are needed to define COPD. Tomographic lung scintigraphy [ventilation/perfusion single photon emission tomography (V/P SPECT)] visualizes regional V and P. In COPD, relations between V/P SPECT, spirometry, high-resolution computed tomography (HRCT) and symptoms have been insufficiently studied. The aim of this study was to investigate how lung function imaging and obstructive disease grading undertaken using V/P SPECT correlate with symptoms, spirometric lung function and degree of emphysema assessed with HRCT in patients with COPD. Thirty patients with stable COPD were evaluated with the Medical Research Council dyspnoea questionnaire (MRC) and the clinical COPD questionnaire (CCQ). Spirometry was performed. The extent of emphysema was assessed using HRCT. V/P SPECT was used to assess V/P patterns, total reduction in lung function and degree of obstructive disease. The total reduction in lung function and degree of obstructive disease, assessed with V/P SPECT, significantly correlated with emphysema extent (r = 0.66-0.69, p < 0.0001) and spirometric lung function (r = 0.62-0.74, p < 0.0005). The correlation between emphysema extent and spirometric lung function was weaker. No correlation between MRC, CCQ and objective measurements was found. V/P SPECT is sensitive to early changes in COPD. V/P SPECT also has the possibility to identify comorbid disease. V/P SPECT findings show a significant correlation with emphysema extent and spirometric lung function. We therefore recommend that scintigraphic signs of COPD, whenever found, should be reported. V

Beware Cold Agglutinins in Organ Donors! Ex Vivo Lung Perfusion From an Uncontrolled Donation After Circulatory-Determination-of-Death Donor With a Cold Agglutinin: A Case Report.

Science.gov (United States)

Venkataraman, A; Blackwell, J W; Funkhouser, W K; Birchard, K R; Beamer, S E; Simmons, W T; Randell, S H; Egan, T M

2017-09-01

We began to recover lungs from uncontrolled donation after circulatory determination of death to assess for transplant suitability by means of ex vivo lung perfusion (EVLP) and computerized tomographic (CT) scan. Our first case had a cold agglutinin with an interesting outcome. A 60-year-old man collapsed at home and was pronounced dead by Emergency Medical Services personnel. Next-of-kin consented to lung retrieval, and the decedent was ventilated and transported. Lungs were flushed with cold Perfadex, removed, and stored cold. The lungs did not flush well. Medical history revealed a recent hemolytic anemia and a known cold agglutinin. Warm nonventilated ischemia time was 51 minutes. O 2 -ventilated ischemia time was 141 minutes. Total cold ischemia time was 6.5 hours. At cannulation for EVLP, established clots were retrieved from both pulmonary arteries. At initiation of EVLP with Steen solution, tiny red aggregates were observed initially. With warming, the aggregates disappeared and the perfusate became red. After 1 hour, EVLP was stopped because of florid pulmonary edema. The lungs were cooled to 20°C; tiny red aggregates formed again in the perfusate. Ex vivo CT scan showed areas of pulmonary edema and a pyramidal right middle lobe opacity. Dissection showed multiple pulmonary emboli-the likely cause of death. However, histology showed agglutinated red blood cells in the microvasculature in pre- and post-EVLP biopsies, which may have contributed to inadequate parenchymal preservation. Organ donors with cold agglutinins may not be suitable owing to the impact of hypothermic preservation. Copyright © 2017 Elsevier Inc. All rights reserved.

Structural and perfusion magnetic resonance imaging of the lung in cystic fibrosis

International Nuclear Information System (INIS)

Amaxopoulou, Christina; Gnannt, Ralph; Kellenberger, Christian J.; Higashigaito, Kai; Jung, Andreas

2018-01-01

Because of its absence of ionising radiation and possibility for obtaining functional information, MRI is promising for assessing lung disease in children who require repetitive imaging for long-term follow-up. To describe MRI findings in children with cystic fibrosis and evaluate semi-quantitative dynamic contrast-enhanced lung perfusion. We retrospectively compared lung MRI in 25 children and young adults with cystic fibrosis (median age 3.7 years) to 12 children (median age 2 years) imaged for other pathologies. MRI at 1.5 T included respiratory-gated sequences and contrast-enhanced lung perfusion imaging. We described and graded any morphologic change. Signal enhancement and time to peak values of perfusion abnormalities were compared to those of normally enhancing lung parenchyma. Frequent findings in patients with cystic fibrosis were bronchial wall thickening (24/25, 96%), areas of consolidation (22/25, 88%), enlarged lymph nodes (20/25, 80%), bronchiectasis (5/25, 20%) and mucus plugging (3/25, 12%). Compared to normally enhancing lung, perfusion defects (21/25, 84%), characterised by decreased enhancement, showed prolonged time to peak. Areas of consolidation showed increased enhancement. While time to peak of procedure-related atelectasis was not significantly different from that of normal lung, disease-related consolidation showed prolonged time to peak (P=0.01). Lung MRI demonstrates structural and perfusion abnormalities in children and young people with cystic fibrosis. Semi-quantitative assessment of dynamic contrast-enhanced perfusion imaging might allow differentiation between procedure-related atelectasis and disease-related consolidation. (orig.)

Structural and perfusion magnetic resonance imaging of the lung in cystic fibrosis

Energy Technology Data Exchange (ETDEWEB)

Amaxopoulou, Christina; Gnannt, Ralph; Kellenberger, Christian J. [University Children' s Hospital Zuerich, Department of Diagnostic Imaging, Zuerich, CH (Switzerland); University Children' s Hospital Zuerich, Children' s Research Center, Zuerich (Switzerland); Higashigaito, Kai [University Hospital Zuerich, Institute of Diagnostic and Interventional Radiology, Zuerich (Switzerland); Jung, Andreas [University Children' s Hospital Zuerich, Children' s Research Center, Zuerich (Switzerland); University Children' s Hospital Zuerich, Division of Pneumology, Zuerich (Switzerland)

2018-02-15

Because of its absence of ionising radiation and possibility for obtaining functional information, MRI is promising for assessing lung disease in children who require repetitive imaging for long-term follow-up. To describe MRI findings in children with cystic fibrosis and evaluate semi-quantitative dynamic contrast-enhanced lung perfusion. We retrospectively compared lung MRI in 25 children and young adults with cystic fibrosis (median age 3.7 years) to 12 children (median age 2 years) imaged for other pathologies. MRI at 1.5 T included respiratory-gated sequences and contrast-enhanced lung perfusion imaging. We described and graded any morphologic change. Signal enhancement and time to peak values of perfusion abnormalities were compared to those of normally enhancing lung parenchyma. Frequent findings in patients with cystic fibrosis were bronchial wall thickening (24/25, 96%), areas of consolidation (22/25, 88%), enlarged lymph nodes (20/25, 80%), bronchiectasis (5/25, 20%) and mucus plugging (3/25, 12%). Compared to normally enhancing lung, perfusion defects (21/25, 84%), characterised by decreased enhancement, showed prolonged time to peak. Areas of consolidation showed increased enhancement. While time to peak of procedure-related atelectasis was not significantly different from that of normal lung, disease-related consolidation showed prolonged time to peak (P=0.01). Lung MRI demonstrates structural and perfusion abnormalities in children and young people with cystic fibrosis. Semi-quantitative assessment of dynamic contrast-enhanced perfusion imaging might allow differentiation between procedure-related atelectasis and disease-related consolidation. (orig.)

Radiospirometry and perfusion scintigraphy in cases of limited pulmonary fibrosis

International Nuclear Information System (INIS)

Tarkowska, A.; Smajkiewicz, L.; Szarewicz-Adamczyk, W.; Zaorska-Rajca, J.; Woytowicz, A.; Patyra, S.

1981-01-01

In 60 cases of limited pulmonary fibrosis radiospirometric investigation was performed using 133 Xe and a four-channel set. Perfusion scintigraphy was done as well after administration of labelled molecules. In all patients abnormalities were found in the results of both isotope methods suggesting presence of disturbances in the regional pulmonary functions. These disturbances included impairment of perfusion as well as ventilation, with evidence of obturation, increased volume of residual air, and decreased vital and total capasity of the lungs. These abnormalities occurred exclusively or most intensively in the areas corresponding to the location of the anatomical change, and in a considerable proportion of cases they were more extensive than the radiological changes. In about 40% of the patients in the contralateral lung diffuse changes of perfusion and ventilation were present, although much less intense, suggesting concomitant chronic obturative disease. The authors think that perfusion scintigraphy and radiospirometry owing to their value as a method of assessing pulmonary function are useful in cases of pulmonary fibrosis for establishing treatment methods and for evaluating disability to work. (author)

Study of regional lung function with xenon 133

International Nuclear Information System (INIS)

Devaux, D.; Wagner, R.; Germain, M.; Chardon, G.

1975-01-01

Exploration of regional lung function includes study of the closed circuit perfusion and ventilation respectively by injection and inhalation of xenon 133. The radiation is measured across the chest using 4 fixed scintillation counters, placed opposite the subject's back, 2 per lung field. Theoretical regional values using 15 normal young subjects are determined. Three cases justified the practical interest of this method. The percentage of variation for the parameters studied was about 10%. The method proved very useful for the clinician to whom it provides a numerical assessment of regional ventilation and perfusion [fr

Ventilation and cardiac related impedance changes in children undergoing corrective open heart surgery

International Nuclear Information System (INIS)

Schibler, Andreas; Pham, Trang M T; Moray, Amol A; Stocker, Christian

2013-01-01

Electrical impedance tomography (EIT) can determine ventilation and perfusion relationship. Most of the data obtained so far originates from experimental settings and in healthy subjects. The aim of this study was to demonstrate that EIT measures the perioperative changes in pulmonary blood flow after repair of a ventricular septum defect in children with haemodynamic relevant septal defects undergoing open heart surgery. In a 19 bed intensive care unit in a tertiary children's hospital ventilation and cardiac related impedance changes were measured using EIT before and after surgery in 18 spontaneously breathing patients. The EIT signals were either filtered for ventilation (ΔZV) or for cardiac (ΔZQ) related impedance changes. Impedance signals were then normalized (normΔZV, normΔZQ) for calculation of the global and regional impedance related ventilation perfusion relationship (normΔZV/normΔZQ). We observed a trend towards increased normΔZV in all lung regions, a significantly decreased normΔZQ in the global and anterior, but not the posterior lung region. The normΔZV/normΔZQ was significantly increased in the global and anterior lung region. Our study qualitatively validates our previously published modified EIT filtration technique in the clinical setting of young children with significant left-to-right shunt undergoing corrective open heart surgery, where perioperative assessment of the ventilation perfusion relation is of high clinical relevance. (paper)

Ventilation and cardiac related impedance changes in children undergoing corrective open heart surgery.

Science.gov (United States)

Schibler, Andreas; Pham, Trang M T; Moray, Amol A; Stocker, Christian

2013-10-01

Electrical impedance tomography (EIT) can determine ventilation and perfusion relationship. Most of the data obtained so far originates from experimental settings and in healthy subjects. The aim of this study was to demonstrate that EIT measures the perioperative changes in pulmonary blood flow after repair of a ventricular septum defect in children with haemodynamic relevant septal defects undergoing open heart surgery. In a 19 bed intensive care unit in a tertiary children's hospital ventilation and cardiac related impedance changes were measured using EIT before and after surgery in 18 spontaneously breathing patients. The EIT signals were either filtered for ventilation (ΔZV) or for cardiac (ΔZQ) related impedance changes. Impedance signals were then normalized (normΔZV, normΔZQ) for calculation of the global and regional impedance related ventilation perfusion relationship (normΔZV/normΔZQ). We observed a trend towards increased normΔZV in all lung regions, a significantly decreased normΔZQ in the global and anterior, but not the posterior lung region. The normΔZV/normΔZQ was significantly increased in the global and anterior lung region. Our study qualitatively validates our previously published modified EIT filtration technique in the clinical setting of young children with significant left-to-right shunt undergoing corrective open heart surgery, where perioperative assessment of the ventilation perfusion relation is of high clinical relevance.

Ex vivo lung perfusion with adenosine A2A receptor agonist allows prolonged cold preservation of lungs donated after cardiac death.

Science.gov (United States)

Wagner, Cynthia E; Pope, Nicolas H; Charles, Eric J; Huerter, Mary E; Sharma, Ashish K; Salmon, Morgan D; Carter, Benjamin T; Stoler, Mark H; Lau, Christine L; Laubach, Victor E; Kron, Irving L

2016-02-01

Ex vivo lung perfusion has been successful in the assessment of marginal donor lungs, including donation after cardiac death (DCD) donor lungs. Ex vivo lung perfusion also represents a unique platform for targeted drug delivery. We sought to determine whether ischemia-reperfusion injury would be decreased after transplantation of DCD donor lungs subjected to prolonged cold preservation and treated with an adenosine A2A receptor agonist during ex vivo lung perfusion. Porcine DCD donor lungs were preserved at 4°C for 12 hours and underwent ex vivo lung perfusion for 4 hours. Left lungs were then transplanted and reperfused for 4 hours. Three groups (n = 4/group) were randomized according to treatment with the adenosine A2A receptor agonist ATL-1223 or the dimethyl sulfoxide vehicle: Infusion of dimethyl sulfoxide during ex vivo lung perfusion and reperfusion (DMSO), infusion of ATL-1223 during ex vivo lung perfusion and dimethyl sulfoxide during reperfusion (ATL-E), and infusion of ATL-1223 during ex vivo lung perfusion and reperfusion (ATL-E/R). Final Pao2/Fio2 ratios (arterial oxygen partial pressure/fraction of inspired oxygen) were determined from samples obtained from the left superior and inferior pulmonary veins. Final Pao2/Fio2 ratios in the ATL-E/R group (430.1 ± 26.4 mm Hg) were similar to final Pao2/Fio2 ratios in the ATL-E group (413.6 ± 18.8 mm Hg), but both treated groups had significantly higher final Pao2/Fio2 ratios compared with the dimethyl sulfoxide group (84.8 ± 17.7 mm Hg). Low oxygenation gradients during ex vivo lung perfusion did not preclude superior oxygenation capacity during reperfusion. After prolonged cold preservation, treatment of DCD donor lungs with an adenosine A2A receptor agonist during ex vivo lung perfusion enabled Pao2/Fio2 ratios greater than 400 mm Hg after transplantation in a preclinical porcine model. Pulmonary function during ex vivo lung perfusion was not predictive of outcomes after transplantation. Copyright �

Role of ventilation scintigraphy in diagnosis of acute pulmonary embolism: an evaluation using artificial neural networks

International Nuclear Information System (INIS)

Evander, Eva; Holst, Holger; Jaerund, Andreas; Wollmer, Per; Edenbrandt, Lars; Ohlsson, Mattias; Aastroem, Karl

2003-01-01

The purpose of this study was to assess the value of the ventilation study in the diagnosis of acute pulmonary embolism using a new automated method. Either perfusion scintigrams alone or two different combinations of ventilation/perfusion scintigrams were used as the only source of information regarding pulmonary embolism. A completely automated method based on computerised image processing and artificial neural networks was used for the interpretation. Three artificial neural networks were trained for the diagnosis of pulmonary embolism. Each network was trained with 18 automatically obtained features. Three different sets of features originating from three sets of scintigrams were used. One network was trained using features obtained from each set of perfusion scintigrams, including six projections. The second network was trained using features from each set of (joint) ventilation and perfusion studies in six projections. A third network was trained using features from the perfusion study in six projections combined with a single ventilation image from the posterior view. A total of 1,087 scintigrams from patients with suspected pulmonary embolism were used for network training. The test group consisted of 102 patients who had undergone both scintigraphy and pulmonary angiography. Performances in the test group were measured as area under the receiver operation characteristic curve. The performance of the neural network in interpreting perfusion scintigrams alone was 0.79 (95% confidence limits 0.71-0.86). When one ventilation image (posterior view) was added to the perfusion study, the performance was 0.84 (0.77-0.90). This increase was statistically significant (P=0.022). The performance increased to 0.87 (0.81-0.93) when all perfusion and ventilation images were used, and the increase in performance from 0.79 to 0.87 was also statistically significant (P=0.016). The automated method presented here for the interpretation of lung scintigrams shows a significant

MRI of the lung

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Kauczor, Hans-Ulrich (ed.) [University Clinic Heidelberg (Germany). Diagnostic and Interventional Radiology

2009-07-01

For a long time, only chest X-ray and CT were used to image lung structure, while nuclear medicine was employed to assess lung function. During the past decade significant developments have been achieved in the field of magnetic resonance imaging (MRI), enabling MRI to enter the clinical arena of chest imaging. Standard protocols can now be implemented on up-to-date scanners, allowing MRI to be used as a first-line imaging modality for various lung diseases, including cystic fibrosis, pulmonary hypertension and even lung cancer. The diagnostic benefits stem from the ability of MRI to visualize changes in lung structure while simultaneously imaging different aspects of lung function, such as perfusion, respiratory motion, ventilation and gas exchange. On this basis, novel quantitative surrogates for lung function can be obtained. This book provides a comprehensive overview of how to use MRI for imaging of lung disease. Special emphasis is placed on benign diseases requiring regular monitoring, given that it is patients with these diseases who derive the greatest benefit from the avoidance of ionizing radiation. (orig.)

Correlation of semiquantitative analysis of the distribution of pulmonary perfusion with pulmonary function in chronic obstructive pulmonary disease

International Nuclear Information System (INIS)

Uchida, Kou; Nakayama, Hiroyuki; Yamagami, Ikue; Takahashi, Hideki; Takano, Masaaki.

1997-01-01

We carried out ventilation-perfusion scintigraphy and pulmonary function tests in 56 patients with chronic obstructive pulmonary disease (COPD) and 19 healthy volunteers. We used 99m Tc-macroaggregated albumin for the perfusion scintigraphy and 133 Xe gas for the ventilation scintigraphy. The lung volume image was created by computerized summation of the radioactivity in the rebreathing phase. Regions of interest (ROIs) were set automatically on lung volume image, which included each whole lung, and on perfusion image, including areas with relatively high radioactivity, with cut-off levels of 50%, 70%, and 90%. The number of pixels in each ROI was used as an index of lung volume (L) or perfusion (P). Perfusion per unit of lung volume (P/L) was also used as an index of perfusion. P70 and P70/L showed the better correlations than the other parameters, including significant correlations with vital capacity, FEV 1.0 , peak flow rate, RV/TLC, diffusing capacity and arterial oxygen partial pressure. The significant difference in P70 and P70/L between patients with hypoxemia and those without hypoxemia suggested that P70 and P70/L are useful indicators of the severity of COPD. We conclude that semiquantified values of pulmonary perfusion scintigraphy are significantly correlated with pulmonary function and the severity of COPD. (author)

Decreased Lung Perfusion After Breast/Chest Wall Irradiation: Quantitative Results From a Prospective Clinical Trial

Energy Technology Data Exchange (ETDEWEB)

Liss, Adam L., E-mail: adamliss68@gmail.com [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Marsh, Robin B. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Kapadia, Nirav S. [Department of Radiation Oncology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire (United States); McShan, Daniel L. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Rogers, Virginia E. [Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Balter, James M.; Moran, Jean M.; Brock, Kristy K.; Schipper, Matt J.; Jagsi, Reshma [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Griffith, Kent A. [Biostatistics Unit, University of Michigan, Ann Arbor, Michigan (United States); Flaherty, Kevin R. [Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States); Frey, Kirk A. [Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Pierce, Lori J. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

2017-02-01

Purpose: To quantify lung perfusion changes after breast/chest wall radiation therapy (RT) using pre- and post-RT single photon emission computed tomography/computed tomography (SPECT/CT) attenuation-corrected perfusion scans; and correlate decreased perfusion with adjuvant RT dose for breast cancer in a prospective clinical trial. Methods and Materials: As part of an institutional review board–approved trial studying the impact of RT technique on lung function in node-positive breast cancer, patients received breast/chest wall and regional nodal irradiation including superior internal mammary node RT to 50 to 52.2 Gy with a boost to the tumor bed/mastectomy scar. All patients underwent quantitative SPECT/CT lung perfusion scanning before RT and 1 year after RT. The SPECT/CT scans were co-registered, and the ratio of decreased perfusion after RT relative to the pre-RT perfusion scan was calculated to allow for direct comparison of SPECT/CT perfusion changes with delivered RT dose. The average ratio of decreased perfusion was calculated in 10-Gy dose increments from 0 to 60 Gy. Results: Fifty patients had complete lung SPECT/CT perfusion data available. No patient developed symptoms consistent with pulmonary toxicity. Nearly all patients demonstrated decreased perfusion in the left lung according to voxel-based analyses. The average ratio of lung perfusion deficits increased for each 10-Gy increment in radiation dose to the lung, with the largest changes in regions of lung that received 50 to 60 Gy (ratio 0.72 [95% confidence interval 0.64-0.79], P<.001) compared with the 0- to 10-Gy region. For each increase in 10 Gy to the left lung, the lung perfusion ratio decreased by 0.06 (P<.001). Conclusions: In the assessment of 50 patients with node-positive breast cancer treated with RT in a prospective clinical trial, decreased lung perfusion by SPECT/CT was demonstrated. Our study allowed for quantification of lung perfusion defects in a prospective cohort of

Ventilation practices in subarachnoid hemorrhage: a cohort study exploring the use of lung protective ventilation.

Science.gov (United States)

Marhong, Jonathan D; Ferguson, Niall D; Singh, Jeffrey M

2014-10-01

Acute respiratory distress syndrome (ARDS) is common following aneurysmal subarachnoid hemorrhage (SAH), but the influence of mechanical ventilator settings on its development is unclear. We sought to determine adherence to lung protective thresholds in ventilated patients with SAH and describe the association between ventilator settings and subsequent development of ARDS. We conducted a retrospective cohort study of consecutive patients receiving mechanical ventilation within 72 h of SAH at a single academic center. Ventilator settings and blood gas data were collected twice daily for the first 7 days of ventilation along with ICU and hospital outcomes. Lung protective ventilation was defined as follows: tidal volume ≤8 mL/kg of predicted body weight, positive end-expiratory pressure (PEEP) ≥5 cm H(2)O, and peak or plateau pressure ≤30 cm H(2)O. The development of ARDS was ascertained retrospectively by PaO(2)/FiO(2) ≤300 with new bilateral lung opacities on chest X-ray within one day of hypoxemia. We identified 62 patients who underwent early mechanical ventilation following SAH. PS and Continuous Positive Airway Pressure were common ventilator modes with a median tidal volume of 7.8 mL/kg [interquartile range 6.8-8.8], median peak pressure of 14 cm H(2)O [IQR 12-17], and median PEEP of 5 cm H(2)O [IQR 5-6]. Adherence to tidal volumes ≤8 mL/kg was seen in 64 % of all observations and peak pressures protective criteria were seen in 58 % of all observations. Thirty-one patients (50 %) were determined to have ARDS. ARDS patients were more frequently ventilated with a peak pressure >30 cm H(2)O (11.3 % of ARDS ventilation days vs. 0 % of non-ARDS ventilation days; p mechanical ventilation frequently breathe spontaneously, generating tidal volumes above usual protective thresholds regardless of meeting ARDS criteria. In patients with SAH, the presence of an additional ARDS risk factor should prompt close screening for the development of ARDS and

Protective mechanical ventilation does not exacerbate lung function impairment or lung inflammation following influenza A infection.

Science.gov (United States)

Zosky, Graeme R; Cannizzaro, Vincenzo; Hantos, Zoltan; Sly, Peter D

2009-11-01

The degree to which mechanical ventilation induces ventilator-associated lung injury is dependent on the initial acute lung injury (ALI). Viral-induced ALI is poorly studied, and this study aimed to determine whether ALI induced by a clinically relevant infection is exacerbated by protective mechanical ventilation. Adult female BALB/c mice were inoculated with 10(4.5) plaque-forming units of influenza A/Mem/1/71 in 50 microl of medium or medium alone. This study used a protective ventilation strategy, whereby mice were anesthetized, tracheostomized, and mechanically ventilated for 2 h. Lung mechanics were measured periodically throughout the ventilation period using a modification of the forced oscillation technique to obtain measures of airway resistance and coefficients of tissue damping and tissue elastance. Thoracic gas volume was measured and used to obtain specific airway resistance, tissue damping, and tissue elastance. At the end of the ventilation period, a bronchoalveolar lavage sample was collected to measure inflammatory cells, macrophage inflammatory protein-2, IL-6, TNF-alpha, and protein leak. Influenza infection caused significant increases in inflammatory cells, protein leak, and deterioration in lung mechanics that were not exacerbated by mechanical ventilation, in contrast to previous studies using bacterial and mouse-specific viral infection. This study highlighted the importance of type and severity of lung injury in determining outcome following mechanical ventilation.

Modelo experimental de perfusão pulmonar ex vivo em ratos: avaliação de desempenho de pulmões submetidos à administração de prostaciclina inalada versus parenteral An experimental rat model of ex vivo lung perfusion for the assessment of lungs after prostacyclin administration: inhaled versus parenteral routes

Directory of Open Access Journals (Sweden)

Paulo Francisco Guerreiro Cardoso

2011-10-01

Full Text Available OBJETIVO: Apresentar um modelo experimental de administração de prostaglandina I2 (PGI2 por via inalatória vs. parenteral e avaliar o desempenho funcional dos pulmões em um sistema de perfusão pulmonar ex vivo. MÉTODOS: Quarenta ratos Wistar foram anestesiados, ventilados, submetidos a laparotomia com ressecção do esterno e anticoagulados. O tronco da artéria pulmonar foi canulado. Todos os animais foram submetidos a ventilação mecânica. Os animais foram randomizados em quatro grupos (10 ratos/grupo: salina nebulizada (SN; salina parenteral (SP; PGI2 nebulizada (PGI2N; e PGI2 parenteral (PGI2P. A dose de PGI2 nos grupos PGI2N e PGI2P foi de 20 e 10 µg/kg, respectivamente. Os blocos cardiopulmonares foram submetidos in situ a perfusão anterógrada com solução de baixo potássio e dextrana a 4ºC via artéria pulmonar, extraídos em bloco e armazenados a 4ºC por 6 h. Os blocos foram ventilados e perfundidos em um sistema ex vivo por 50 min, sendo obtidas medidas de mecânica ventilatória, hemodinâmica e trocas gasosas. RESULTADOS: Houve redução da pressão arterial pulmonar média após a nebulização em todos os grupos (p OBJECTIVE:To present a model of prostaglandin I2 (PGI2 administration (inhaled vs. parenteral and to assess the functional performance of the lungs in an ex vivo lung perfusion system. METHODS: Forty Wistar rats were anesthetized and placed on mechanical ventilation followed by median sterno-laparotomy and anticoagulation. The main pulmonary artery was cannulated. All animals were maintained on mechanical ventilation and were randomized into four groups (10 rats/group: inhaled saline (IS; parenteral saline (PS; inhaled PGI2 (IPGI2; and parenteral PGI2 (PPGI2. The dose of PGI2 used in the IPGI2 and PPGI2 groups was 20 and 10 µg/kg, respectively. The heart-lung blocks were submitted to antegrade perfusion with a low potassium and dextran solution via the pulmonary artery, followed by en bloc extraction and

Usefulness of pulmonary scintigraphy in primary lung cancer patients treated by radiotherapy

International Nuclear Information System (INIS)

Mitomo, Osamu

1994-01-01

To assess the pulmonary function of lung cancer patients treated by radiotherapy, we tried qualitative and semiquantitative analysis of pulmonary scintigrams using 133 Xe and 99m Tc-MAA. Individual scores for ventilation, perfusion and the ventilation-perfusion ratio of tumor-bearing lungs were calculated on the basis of healthy control cases in order to analyze whether, and to what degree, the tumor-bearing lung was functionally impaired. The score was proportional to the severity of impairment, and when the ventilation and perfusion of tumor-bearing lungs had a score of one or greater than one, the tumor-bearing lung was functionally defined as an 'impaired lung'. Impaired lungs were demonstrated in 68% of tumor-bearing lungs. Hilar and left hilar-type cancers, clinically more advanced cancers, patients whose tumors were confirmed by bronchofiberscopy, small-cell and epidermoid cancers, etc., had higher rates of impairment and more severe impairment. Many patients with impaired lungs had a worse prognosis, but patients in whom scintigraphy showed improvement after radiotherapy had a better prognosis. It can be concluded that pulmonary scintigraphy scoring is capable of semiquantitatively indicating the degree of pulmonary impairment and is useful in deciding on a radiotherapeutic plan and predicting the outcome in pre- and post-radiotherapy lung cancer patients. (author)

Lung-protective mechanical ventilation does not protect against acute kidney injury in patients without lung injury at onset of mechanical ventilation

NARCIS (Netherlands)

Cortjens, Bart; Royakkers, Annick A. N. M.; Determann, Rogier M.; van Suijlen, Jeroen D. E.; Kamphuis, Stephan S.; Foppen, Jannetje; de Boer, Anita; Wieland, Cathrien W.; Spronk, Peter E.; Schultz, Marcus J.; Bouman, Catherine S. C.

2012-01-01

Introduction: Preclinical and clinical studies suggest that mechanical ventilation contributes to the development of acute kidney injury (AKI), particularly in the setting of lung-injurious ventilator strategies. Objective: To determine whether ventilator settings in critically ill patients without

Effect of PEEP and inhaled nitric oxide on pulmonary gas exchange during gaseous and partial liquid ventilation with small volumes of perfluorocarbon.

Science.gov (United States)

Max, M; Kuhlen, R; Falter, F; Reyle-Hahn, M; Dembinski, R; Rossaint, R

2000-04-01

Partial liquid ventilation, positive end-expiratory pressure (PEEP) and inhaled nitric oxide (NO) can improve ventilation/perfusion mismatch in acute lung injury (ALI). The aim of the present study was to compare gas exchange and hemodynamics in experimental ALI during gaseous and partial liquid ventilation at two different levels of PEEP, with and without the inhalation of nitric oxide. Seven pigs (24+/-2 kg BW) were surfactant-depleted by repeated lung lavage with saline. Gas exchange and hemodynamic parameters were assessed in all animals during gaseous and subsequent partial liquid ventilation at two levels of PEEP (5 and 15 cmH2O) and intermittent inhalation of 10 ppm NO. Arterial oxygenation increased significantly with a simultaneous decrease in cardiac output when PEEP 15 cmH2O was applied during gaseous and partial liquid ventilation. All other hemodynamic parameters revealed no relevant changes. Inhalation of NO and instillation of perfluorocarbon had no additive effects on pulmonary gas exchange when compared to PEEP 15 cmH2O alone. In experimental lung injury, improvements in gas exchange are most distinct during mechanical ventilation with PEEP 15 cmH2O without significantly impairing hemodynamics. Partial liquid ventilation and inhaled NO did not cause an additive increase of PaO2.

Patients with uninjured lungs may also benefit from lung-protective ventilator settings [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Roger Alencar

2017-11-01

Full Text Available Although mechanical ventilation is a life-saving strategy in critically ill patients and an indispensable tool in patients under general anesthesia for surgery, it also acts as a double-edged sword. Indeed, ventilation is increasingly recognized as a potentially dangerous intrusion that has the potential to harm lungs, in a condition known as ‘ventilator-induced lung injury’ (VILI. So-called ‘lung-protective’ ventilator settings aiming at prevention of VILI have been shown to improve outcomes in patients with acute respiratory distress syndrome (ARDS, and, over the last few years, there has been increasing interest in possible benefit of lung-protective ventilation in patients under ventilation for reasons other than ARDS. Patients without ARDS could benefit from tidal volume reduction during mechanical ventilation. However, it is uncertain whether higher levels of positive end-expiratory pressure could benefit these patients as well. Finally, recent evidence suggests that patients without ARDS should receive low driving pressures during ventilation.

Numerical simulation of volume-controlled mechanical ventilated respiratory system with 2 different lungs.

Science.gov (United States)

Shi, Yan; Zhang, Bolun; Cai, Maolin; Zhang, Xiaohua Douglas

2017-09-01

Mechanical ventilation is a key therapy for patients who cannot breathe adequately by themselves, and dynamics of mechanical ventilation system is of great significance for life support of patients. Recently, models of mechanical ventilated respiratory system with 1 lung are used to simulate the respiratory system of patients. However, humans have 2 lungs. When the respiratory characteristics of 2 lungs are different, a single-lung model cannot reflect real respiratory system. In this paper, to illustrate dynamic characteristics of mechanical ventilated respiratory system with 2 different lungs, we propose a mathematical model of mechanical ventilated respiratory system with 2 different lungs and conduct experiments to verify the model. Furthermore, we study the dynamics of mechanical ventilated respiratory system with 2 different lungs. This research study can be used for improving the efficiency and safety of volume-controlled mechanical ventilation system. Copyright © 2016 John Wiley & Sons, Ltd.

Lung inhalation scintigraphy with radioactive aerosols in several pulmonary diseases. Cintigrafia de ventialacao pulmonar por aerosol em diversas patologias pulmonares

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Martins, L R; Marioni Filho, H [Instituto Dante Pazzanese de Cardiologia, Sao Paulo, SP (Brazil); Romaldini, H; Uehara, C; Alonso, G [Escola Paulista de Medicina, Sao Paulo, SP (Brazil)

1983-01-01

The pulmonary ventilation scintigraphy with 99m Tc diethylene-triamine-pentaacetate (99mTc-DTPA) delivered through a new nebulizer system when analyzed together with the classic lung perfusion scintigraphy with 99mTc-labeled albumin macroaggregates (99mTcMAA) is a very important diagnostic tool in several pulmonary diseases. Several aspects of the lung ventilation-perfusion scintigraphy are studied in 15 people with no lung disease, smokers and nonsmokers. The findings with the lung ventilation-perfusion scintigraphy are also discussed in 34 patients with several pulmonary diseases: lung cancer, chronic obstructive lung disease, policystic pulmonary disease, and pulmonary embolims. The authors concluded that the procedure is a valuable diagnostic tool in several pulmonary diseases, especially because good lung images are obtained, no side effects were detected, the technique is ease and low cost, and it brings new informations, not available with other diagnostic methods. (author).

Histogram based analysis of lung perfusion of children after congenital diaphragmatic hernia repair.

Science.gov (United States)

Kassner, Nora; Weis, Meike; Zahn, Katrin; Schaible, Thomas; Schoenberg, Stefan O; Schad, Lothar R; Zöllner, Frank G

2018-05-01

To investigate a histogram based approach to characterize the distribution of perfusion in the whole left and right lung by descriptive statistics and to show how histograms could be used to visually explore perfusion defects in two year old children after Congenital Diaphragmatic Hernia (CDH) repair. 28 children (age of 24.2±1.7months; all left sided hernia; 9 after extracorporeal membrane oxygenation therapy) underwent quantitative DCE-MRI of the lung. Segmentations of left and right lung were manually drawn to mask the calculated pulmonary blood flow maps and then to derive histograms for each lung side. Individual and group wise analysis of histograms of left and right lung was performed. Ipsilateral and contralateral lung show significant difference in shape and descriptive statistics derived from the histogram (Wilcoxon signed-rank test, phistogram derived parameters. Histogram analysis can be a valuable tool to characterize and visualize whole lung perfusion of children after CDH repair. It allows for several possibilities to analyze the data, either describing the perfusion differences between the right and left lung but also to explore and visualize localized perfusion patterns in the 3D lung volume. Subgroup analysis will be possible given sufficient sample sizes. Copyright © 2017 Elsevier Inc. All rights reserved.

Adaptive support ventilation may deliver unwanted respiratory rate-tidal volume combinations in patients with acute lung injury ventilated according to an open lung concept.

Science.gov (United States)

Dongelmans, Dave A; Paulus, Frederique; Veelo, Denise P; Binnekade, Jan M; Vroom, Margreeth B; Schultz, Marcus J

2011-05-01

With adaptive support ventilation, respiratory rate and tidal volume (V(T)) are a function of the Otis least work of breathing formula. We hypothesized that adaptive support ventilation in an open lung ventilator strategy would deliver higher V(T)s to patients with acute lung injury. Patients with acute lung injury were ventilated according to a local guideline advising the use of lower V(T) (6-8 ml/kg predicted body weight), high concentrations of positive end-expiratory pressure, and recruitment maneuvers. Ventilation parameters were recorded when the ventilator was switched to adaptive support ventilation, and after recruitment maneuvers. If V(T) increased more than 8 ml/kg predicted body weight, airway pressure was limited to correct for the rise of V(T). Ten patients with a mean (±SD) Pao(2)/Fio(2) of 171 ± 86 mmHg were included. After a switch from pressure-controlled ventilation to adaptive support ventilation, respiratory rate declined (from 31 ± 5 to 21 ± 6 breaths/min; difference = 10 breaths/min, 95% CI 3-17 breaths/min, P = 0.008) and V(T) increased (from 6.5 ± 0.8 to 9.0 ± 1.6 ml/kg predicted body weight; difference = 2.5 ml, 95% CI 0.4-4.6 ml/kg predicted body weight, P = 0.02). Pressure limitation corrected for the rise of V(T), but minute ventilation declined, forcing the user to switch back to pressure-controlled ventilation. Adaptive support ventilation, compared with pressure-controlled ventilation in an open lung strategy setting, delivers a lower respiratory rate-higher V(T) combination. Pressure limitation does correct for the rise of V(T), but leads to a decline in minute ventilation.

Perioperative lung protective ventilation in obese patients

NARCIS (Netherlands)

Fernandez-Bustamante, Ana; Hashimoto, Soshi; Serpa Neto, Ary; Moine, Pierre; Vidal Melo, Marcos F.; Repine, John E.

2015-01-01

The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent

Correlation between alveolar ventilation and electrical properties of lung parenchyma.

Science.gov (United States)

Roth, Christian J; Ehrl, Andreas; Becher, Tobias; Frerichs, Inéz; Schittny, Johannes C; Weiler, Norbert; Wall, Wolfgang A

2015-06-01

One key problem in modern medical imaging is linking measured data and actual physiological quantities. In this article we derive such a link between the electrical bioimpedance of lung parenchyma, which can be measured by electrical impedance tomography (EIT), and the magnitude of regional ventilation, a key to understanding lung mechanics and developing novel protective ventilation strategies. Two rat-derived three-dimensional alveolar microstructures obtained from synchrotron-based x-ray tomography are each exposed to a constant potential difference for different states of ventilation in a finite element simulation. While the alveolar wall volume remains constant during stretch, the enclosed air volume varies, similar to the lung volume during ventilation. The enclosed air, serving as insulator in the alveolar ensemble, determines the resulting current and accordingly local tissue bioimpedance. From this we can derive a relationship between lung tissue bioimpedance and regional alveolar ventilation. The derived relationship shows a linear dependence between air content and tissue impedance and matches clinical data determined from a ventilated patient at the bedside.

SU-E-J-87: Ventilation Weighting Effect On Mean Doses of Both Side Lungs for Patients with Advanced Stage Lung Cancer

International Nuclear Information System (INIS)

Qu, H; Xia, P; Yu, N

2015-01-01

Purpose: To study ventilation weighting effect on radiation doses to both side lungs for patients with advanced stage lung cancer. Methods: Fourteen patients with advanced stage lung cancer were included in this retrospective study. Proprietary software was developed to calculate the lung ventilation map based on 4DCT images acquired for radiation therapy. Two phases of inhale (0%) and exhale (50%) were used for the lung ventilation calculations. For each patient, the CT images were resampled to the same dose calculation resolution of 3mmx3mmx3mm. The ventilation distribution was then normalized by the mean value of the ventilation. The ventilation weighted dose was calculated by applying linearly weighted ventilation to the dose of each pixel. The lung contours were automatically delineated from patient CT image with lung window, excluding the tumor and high density tissues. For contralateral and ipsilateral lungs, the mean lung doses from the original plan and ventilation weighted mean lung doses were compared using two tail t-Test. Results: The average of mean dose was 6.1 ±3.8Gy for the contralateral lungs, and 26.2 ± 14.0Gy for the ipsilateral lungs. The average of ventilation weighted dose was 6.3± 3.8Gy for the contralateral lungs and 24.6 ± 13.1Gy for the ipsilateral lungs. The statistics analysis shows the significance of the mean dose increase (p<0.015) for the contralateral lungs and decrease (p<0.005) for the ipsilateral lungs. Conclusion: Ventilation weighted doses were greater than the un-weighted doses for contralateral lungs and smaller for ipsilateral lungs. This Result may be helpful to understand the radiation dosimetric effect on the lung function and provide planning guidance for patients with advance stage lung cancer

Positioning effects on lung ventilation in older normal subjects: a technegas study

International Nuclear Information System (INIS)

Krieg, S.; McCarren, B.; Alison, J.; Cowell, S.F.; Leiper, C.; Bankstown-Lidcombe Hospital, Sydney, NSW; El Zein, H.

2002-01-01

Full text: While the effects of positioning on the distribution of ventilation in the lungs of younger subjects has been relatively well investigated, this is not so in the older age group. Known age-associated changes in the respiratory system are proposed to alter the distribution of ventilation in the lungs of older people. The aim of the present study was therefore to determine the effects of positioning on the distribution of ventilation in the lungs of older normal subjects. The distribution of ventilation in upright sitting and right side lying was measured in ten subjects using Technegas lung ventilation during tidal breathing. In the upright sitting position ventilation was preferentially distributed to the middle and basal regions (dependent regions). Right side lying ventilation was preferentially distributed to the right lung (dependent region). These results suggest that preferential distribution of ventilation to the dependent lung regions in older subjects is mainly due to the gravity-dependent gradient in pleural pressure. It is proposed that this distribution may partly result from loss of elasticity in the lungs with ageing. Predominantly, the distribution of ventilation in the lungs of older normal subjects in our study is similar to that previously described in younger subjects (Amis et al., 1984, Kaneko et al, 1966, Milic-Emili et al, 1966. This suggests that a similar pleural pressure gradient may exist in the lungs of older and younger subjects. This is an important implication as the majority of patients that physiotherapists treat with cardiopulmonary dysfunction are in the older age group. Further research is required to determine the effects of positioning on the distribution of ventilation in older patients with cardiopulmonary dysfunction to enable direct clinical implications to be made. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

Protective ventilation of preterm lambs exposed to acute chorioamnionitis does not reduce ventilation-induced lung or brain injury.

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Barton, Samantha K; Moss, Timothy J M; Hooper, Stuart B; Crossley, Kelly J; Gill, Andrew W; Kluckow, Martin; Zahra, Valerie; Wong, Flora Y; Pichler, Gerhard; Galinsky, Robert; Miller, Suzanne L; Tolcos, Mary; Polglase, Graeme R

2014-01-01

The onset of mechanical ventilation is a critical time for the initiation of cerebral white matter (WM) injury in preterm neonates, particularly if they are inadvertently exposed to high tidal volumes (VT) in the delivery room. Protective ventilation strategies at birth reduce ventilation-induced lung and brain inflammation and injury, however its efficacy in a compromised newborn is not known. Chorioamnionitis is a common antecedent of preterm birth, and increases the risk and severity of WM injury. We investigated the effects of high VT ventilation, after chorioamnionitis, on preterm lung and WM inflammation and injury, and whether a protective ventilation strategy could mitigate the response. Pregnant ewes (n = 18) received intra-amniotic lipopolysaccharide (LPS) 2 days before delivery, instrumentation and ventilation at 127±1 days gestation. Lambs were either immediately euthanased and used as unventilated controls (LPSUVC; n = 6), or were ventilated using an injurious high VT strategy (LPSINJ; n = 5) or a protective ventilation strategy (LPSPROT; n = 7) for a total of 90 min. Mean arterial pressure, heart rate and cerebral haemodynamics and oxygenation were measured continuously. Lungs and brains underwent molecular and histological assessment of inflammation and injury. LPSINJ lambs had poorer oxygenation than LPSPROT lambs. Ventilation requirements and cardiopulmonary and systemic haemodynamics were not different between ventilation strategies. Compared to unventilated lambs, LPSINJ and LPSPROT lambs had increases in pro-inflammatory cytokine expression within the lungs and brain, and increased astrogliosis (pVentilation after acute chorioamnionitis, irrespective of strategy used, increases haemodynamic instability and lung and cerebral inflammation and injury. Mechanical ventilation is a potential contributor to WM injury in infants exposed to chorioamnionitis.

Simultaneous measurement of pO2 and perfusion in the rabbit kidney in vivo.

Science.gov (United States)

O'Connor, Paul M; Anderson, Warwick P; Kett, Michelle M; Evans, Roger G

2007-01-01

Recently, a combined probe has been developed capable of simultaneous measurement of local tissue pO2 (fluorescence oximetry) and microvascular perfusion (laser Doppler flux) within the same local region. The aim of the current study was to test the utility of these combined probes to measure pO2 and perfusion in the kidney. Studies were performed in anesthetized, artificially ventilated rabbits (n=7). Baseline measurements of renal medullary perfusion and pO2 obtained using combined probes (537 +/- 110 units & 28.7 +/- 6.l mmHg, respectively) were indistinguishable from those obtained using independent probes (435 +/- 102 units & 26.9 +/- 6.4 mmHg). Baseline measurements of renal cortical pO2 were also similar between combined (9.7 +/- 1.6 mmHg) and independent probes (9.5 +/- 2.3 mmHg). Baseline levels of cortical perfusion however, were significantly greater when measured using independent probes (1130 +/- 114 units) compared to combined probes (622 +/- 59 units; P pO2 resulting from graded stimulation of the renal nerves were not significantly different when measured using combined probes to those obtained using independent probes. We conclude that combined probes are equally suitable to independent probes for tissue pO2 and microvascular perfusion measurement in the kidney. Our results raise some concerns regarding the accuracy of these OxyLite fluorescence probes for pO2 measurement in the kidney, particularly within the renal cortex.

Quantitative Xe-133 perfusion and exhalation scintigraphy of lungs in children with asthma

International Nuclear Information System (INIS)

Lederer, A.G.; Sternthal, H.M.; Nicoletti, R.; Fuger, G.F.

1990-01-01

In children with asthma, the authors quantified the extent of the obstructive lung disease by calculating a time to peak (TTP) and mean transit time (MTT) image. In this paper compare the results to common pulmonary function tests. The authors studied 17 children twice: first, after the initial intravenous therapy after an asthmatic attach and, second, before discharge from the hospital. After intravenous injection of 185-370 MBq of Xe-133, a dynamic computer acquisition was performed, and a TTP and MTT image were calculated. The authors were able to estimate the extent, intensity (qualified by the MTT), and location of the ventilation disorder as well as the changes of perfusion (expressed by the TTP) in sever disease

Ventilation studies of the lung with krypton-81m

International Nuclear Information System (INIS)

Klopper, J.F.; Baard, W.P.; Van Heerden, P.D.R.

1981-01-01

During a 2-year study period it was found that krypton-81m was useful in clinical practice. During this period 1563 technetium-99m perfusion studies and 807 krypton-81m ventilation studies were performed. A distinct advantage of krypton-81m was the ease with which multiple views could be obtained. These views could be directly compared with those of preceding perfusion studies. However, interruptions in the regular supply of rubidium-81/krypton-81m generators affected 17,1% of perfusion studies and xenon-127 should be a suitable substitute for these periods

Sevoflurane posttreatment prevents oxidative and inflammatory injury in ventilator-induced lung injury.

Directory of Open Access Journals (Sweden)

Julie Wagner

Full Text Available Mechanical ventilation is a life-saving clinical treatment but it can induce or aggravate lung injury. New therapeutic strategies, aimed at reducing the negative effects of mechanical ventilation such as excessive production of reactive oxygen species, release of pro-inflammatory cytokines, and transmigration as well as activation of neutrophil cells, are needed to improve the clinical outcome of ventilated patients. Though the inhaled anesthetic sevoflurane is known to exert organ-protective effects, little is known about the potential of sevoflurane therapy in ventilator-induced lung injury. This study focused on the effects of delayed sevoflurane application in mechanically ventilated C57BL/6N mice. Lung function, lung injury, oxidative stress, and inflammatory parameters were analyzed and compared between non-ventilated and ventilated groups with or without sevoflurane anesthesia. Mechanical ventilation led to a substantial induction of lung injury, reactive oxygen species production, pro-inflammatory cytokine release, and neutrophil influx. In contrast, sevoflurane posttreatment time dependently reduced histological signs of lung injury. Most interestingly, increased production of reactive oxygen species was clearly inhibited in all sevoflurane posttreatment groups. Likewise, the release of the pro-inflammatory cytokines interleukin-1β and MIP-1β and neutrophil transmigration were completely prevented by sevoflurane independent of the onset of sevoflurane administration. In conclusion, sevoflurane posttreatment time dependently limits lung injury, and oxidative and pro-inflammatory responses are clearly prevented by sevoflurane irrespective of the onset of posttreatment. These findings underline the therapeutic potential of sevoflurane treatment in ventilator-induced lung injury.

Lung scan abnormalities in asthma and their correlation with lung function

International Nuclear Information System (INIS)

Vernon, P.; Burton, G.H.; Seed, W.A.; Charing Cross Hospital, London

1986-01-01

We have used asthma as a model of airways disease to test how well an automated, quantitative method of analysis of lung scans correlates with physiological measurements of disturbed lung function and gas exchange. We studies 25 asthmatics (age 16-73) of widely differing severity (forced expiratory volume in 1-s FEV 1 22%-123% of predicted value), who had airways tests, arterial blood gas analysis, and krypton-technetium lung scans within a short time of each other. In all patients with airways obstruction and in some with normal function during remission, scans showed the typical appearances of multiple defects of ventilation and perfusion. The severity of ventilation defects was assessed from the posterior view of the krypton scan compared to an age- and sex-matched normal range to yield an underventilation score. This correlated closely with the severity of airways obstruction as measured by forced expiratory manouevres. Ventilation and perfusion defects were usually imperfectly matched; the severity of this was computed using a subtraction method applied to the counts on the posterior krypton and technetium scans. The degree of mismatch was inversely related to the arterial partial pressure of oxygen (r=-0.86). The results suggest that computer scan analysis can provide usual functional information about the lung in airways disease. (orig.)

Role of radio-aerosol and perfusion lung imaging in early detection of chronic obstructive lung disease

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Garg, A; Pande, J N; Guleria, J S; Gopinath, P G

1983-04-01

The efficacy of radio-aerosol and perfusion lung imaging in the early detection of chronic obstructive lung disease was evaluated in 38 subjects. The subjects included 5 non-smokers, 21 smokers with minimal or no respiratory symptoms and 12 patients with chronic obstructive lung disease. Each subject consented to a respiratory questionaire, detailed physical examination, chest X-ray examinations, detailed pulmonary function tests and sup(99m)Tc-radioaerosol-inhalation lung imaging. Perfusion lung imaging with sup(99m)Tc-labelled macroaggregated albumin was performed in 22 subjects. A significant correlation (P<0.001) was observed between the degree of abnormalities on radio-aerosol imaging and pulmonary function tests (PFTs) including forced expiratory volume in 1 s, maximum midexpiratory flow rate and mean transit time analysis. Abnormal radio-aerosol patterns and deranged PFTs were observed in 21 subjects each. Of 21 subjects with abnormal radioaerosol pattern 8 had normal PFTs. Of 21 subjects with abnormal PFTs 8 had normal aerosol images. Aerosol lung images and PFTs were abnormal more frequently than perfusion lung images. The results suggest that radio-aerosol lung imaging is as sensitive an indicator as PFTs for early detection of chronic obstructive lung disease and can be usefully combined with PFTs for early detection of alteration in pulmonary physiology in smokers.

Clinical study of regional ventilation and perfusion of pulmonary disease by ventilatory steady state measurement with Xe-133

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Nishi, Fumiaki

1984-12-01

Ventilatory steady state measurement with Xe-133 were performed to evaluate regional ventilation (V radical) and perfusion (Q radical) in 60 cases of primary lung cancer and 39 cases of pulmonary diseases-chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, sarcoidosis, mitral stenosis with pulmonary hypertension (PH), pulmonary alveolar proteinosis, bronchial adenoma and pulmonary embolism. Of 60 cases of lung cancer, 11 cases showed V radicalQ radical mismatch (18%). Even in the V radicalQ radical matched defect cases, a different grade of disorder was seen in V radical and Q radical and the grade of Q radical was severer than the grade of V radical. Of 38 cases irradiated by Linac X-ray, 3 cases whose V radical, Q radical were disordered a little before irradiation recovered completely to normal range after irradiadiation. Of 38 cases subjected to radiation therapy, radiation injury of lung was recognized in 22 cases. In the cases of recovered V radical, Q radical after irradiation, radiation injury of lung occurred, and then V radical, Q radical disordered and returned to pre-irradiation value. In the cases that recovered little in V radical, Q radical, radiation injury of lung occurred, and then V radical, Q radical could not return to pre-irradiation value. In 39 cases of pulmonary diseases, 7 cases of sarcoidosis showed normal V radical and Q radical value. 13 cases of COPD was available to evaluate the regional pulmonary function in MTT (Mean Transit Time). V radical, Q radical were slightly disordered and MTT proloned slightly in 10 cases of diffuse pulmonary fibrosis where a marked fibrosis lesion was remarkable. Six cases of PH showed significant correlation between the left ventricular mean pressure and the perfusion ratio of upper and lower lung field. (J.P.N.).

Clinical study of regional ventilation and perfusion of pulmonary disease by ventilatory steady state measurement with Xe-133

International Nuclear Information System (INIS)

Nishi, Fumiaki

1984-01-01

Ventilatory steady state measurement with Xe-133 were performed to evaluate regional ventilation (V radical) and perfusion (Q radical) in 60 cases of primary lung cancer and 39 cases of pulmonary diseases-chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, sarcoidosis, mitral stenosis with pulmonary hypertension (PH), pulmonary alveolar proteinosis, bronchial adenoma and pulmonary embolism. Of 60 cases of lung cancer, 11 cases showed V radicalQ radical mismatch (18%). Even in the V radicalQ radical matched defect cases, a different grade of disorder was seen in V radical and Q radical and the grade of Q radical was severer than the grade of V radical. Of 38 cases irradiated by Linac X-ray, 3 cases whose V radical, Q radical were disordered a little before irradiation recovered completely to normal range after irradiadiation. Of 38 cases who performed the radiation therapy, radiation injury of lung was recognized in 22 cases. In the cases of recovered V radical, Q radical after irradiation, radiation injury of lung occurred, and then V radical, Q radical disordered and returned to pre-irradiation value. In the cases that recovered little in V radical, Q radical, radiation injury of lung occurred, and then V radical, Q radical could not return to pre-irradiation value. In 39 cases of pulmonary diseases, 7 cases of sarcoidosis showed normal V radical and Q radical value. 13 cases of COPD was available to evaluate the regional pulmonary function in MTT (Mean Transit Time). V radical, Q radical were slightly disordered and MTT proloned slightly in 10 cases of diffuse pulmonary fibrosis where a marked fibrosis lesion was remarkable. Six cases of PH showed significant correlation between the left ventricular mean pressure and the perfusion ratio of upper and lower lung field. (J.P.N.)

Clinical evaluation of lung rest/stress perfusion scintigraphy in patients with severe emphysema

International Nuclear Information System (INIS)

Hadjikostova, Hr.

1998-01-01

Volume lung reduction surgery (LVRS) improves lung function and physical tolerance for selected patients with severe pulmonary emphysema by making conditions for developing of the vital parenchyma so far compressed by the emphysema blisters. The aim of this study was to establish the comparative functional information obtained from REST/STRESS lung perfusion tomoscintigraphies for identification of non functional lung tissue. Eleven patients (8 males and 3 females at age 41-60) were examined by two lung perfusions SPECT scintigraphies after intravenous application of 222 MBq 99m Tc-MAA: 1. after 30 min. lying rest and 2. 48 hours later after 6 min. walk test. Comparing the two scintigraphies the following changes in perfusion performance have been established at STRESS examination: increased at six patients (significant at three and slight also at three) and decreased at two. There was no difference between REST and STRESS examinations at 3 patients. Comparative REST/STRESS lung perfusion scintigraphy is important method for screening severe pulmonary patients for LVRS. (author)

Lung-protective mechanical ventilation does not protect against acute kidney injury in patients without lung injury at onset of mechanical ventilation.

Science.gov (United States)

Cortjens, Bart; Royakkers, Annick A N M; Determann, Rogier M; van Suijlen, Jeroen D E; Kamphuis, Stephan S; Foppen, Jannetje; de Boer, Anita; Wieland, Cathrien W; Spronk, Peter E; Schultz, Marcus J; Bouman, Catherine S C

2012-06-01

Preclinical and clinical studies suggest that mechanical ventilation contributes to the development of acute kidney injury (AKI), particularly in the setting of lung-injurious ventilator strategies. To determine whether ventilator settings in critically ill patients without acute lung injury (ALI) at onset of mechanical ventilation affect the development of AKI. Secondary analysis of a randomized controlled trial (N = 150), comparing conventional tidal volume (V(T), 10 mL/kg) with low tidal volume (V(T), 6 mL/kg) mechanical ventilation in critically ill patients without ALI at randomization. During the first 5 days of mechanical ventilation, the RIFLE class was determined daily, whereas neutrophil gelatinase-associated lipocalin and cystatin C levels were measured in plasma collected on days 0, 2, and 4. Eighty-six patients had no AKI at inclusion, and 18 patients (21%) subsequently developed AKI, but without significant difference between ventilation strategies. (Cumulative hazard, 0.26 vs 0.23; P = .88.) The courses of neutrophil gelatinase-associated lipocalin and cystatin C plasma levels did not differ significantly between randomization groups. In the present study in critically patients without ALI at onset of mechanical ventilation, lower tidal volume ventilation did not reduce the development or worsening of AKI compared with conventional tidal volume ventilation. Copyright © 2012 Elsevier Inc. All rights reserved.

Effects of lung protective mechanical ventilation associated with permissive respiratory acidosis on regional extra-pulmonary blood flow in experimental ARDS.

Science.gov (United States)

Hering, Rudolf; Kreyer, Stefan; Putensen, Christian

2017-10-27

Lung protective mechanical ventilation with limited peak inspiratory pressure has been shown to affect cardiac output in patients with ARDS. However, little is known about the impact of lung protective mechanical ventilation on regional perfusion, especially when associated with moderate permissive respiratory acidosis. We hypothesized that lung protective mechanical ventilation with limited peak inspiratory pressure and moderate respiratory acidosis results in an increased cardiac output but unequal distribution of blood flow to the different organs of pigs with oleic-acid induced ARDS. Twelve pigs were enrolled, 3 died during instrumentation and induction of lung injury. Thus, 9 animals received pressure controlled mechanical ventilation with a PEEP of 5 cmH 2 O and limited peak inspiratory pressure (17 ± 4 cmH 2 O) versus increased peak inspiratory pressure (23 ± 6 cmH 2 O) in a crossover-randomized design and were analyzed. The sequence of limited versus increased peak inspiratory pressure was randomized using sealed envelopes. Systemic and regional hemodynamics were determined by double indicator dilution technique and colored microspheres, respectively. The paired student t-test and the Wilcoxon test were used to compare normally and not normally distributed data, respectively. Mechanical ventilation with limited inspiratory pressure resulted in moderate hypercapnia and respiratory acidosis (PaCO 2 71 ± 12 vs. 46 ± 9 mmHg, and pH 7.27 ± 0.05 vs. 7.38 ± 0.04, p respiratory acidosis was associated with an increase in cardiac output. However, the better systemic blood flow was not uniformly directed to the different organs. This observation may be of clinical interest in patients, e.g. with cardiac, renal and cerebral pathologies.

Selective Heart, Brain and Body Perfusion in Open Aortic Arch Replacement.

Science.gov (United States)

Maier, Sven; Kari, Fabian; Rylski, Bartosz; Siepe, Matthias; Benk, Christoph; Beyersdorf, Friedhelm

2016-09-01

Open aortic arch replacement is a complex and challenging procedure, especially in post dissection aneurysms and in redo procedures after previous surgery of the ascending aorta or aortic root. We report our experience with the simultaneous selective perfusion of heart, brain, and remaining body to ensure optimal perfusion and to minimize perfusion-related risks during these procedures. We used a specially configured heart-lung machine with a centrifugal pump as arterial pump and an additional roller pump for the selective cerebral perfusion. Initial arterial cannulation is achieved via femoral artery or right axillary artery. After lower body circulatory arrest and selective antegrade cerebral perfusion for the distal arch anastomosis, we started selective lower body perfusion simultaneously to the selective antegrade cerebral perfusion and heart perfusion. Eighteen patients were successfully treated with this perfusion strategy from October 2012 to November 2015. No complications related to the heart-lung machine and the cannulation occurred during the procedures. Mean cardiopulmonary bypass time was 239 ± 33 minutes, the simultaneous selective perfusion of brain, heart, and remaining body lasted 55 ± 23 minutes. One patient suffered temporary neurological deficit that resolved completely during intensive care unit stay. No patient experienced a permanent neurological deficit or end-organ dysfunction. These high-risk procedures require a concept with a special setup of the heart-lung machine. Our perfusion strategy for aortic arch replacement ensures a selective perfusion of heart, brain, and lower body during this complex procedure and we observed excellent outcomes in this small series. This perfusion strategy is also applicable for redo procedures.

Dynamic Chest Image Analysis: Model-Based Perfusion Analysis in Dynamic Pulmonary Imaging

Directory of Open Access Journals (Sweden)

Kiuru Aaro

2003-01-01

Full Text Available The "Dynamic Chest Image Analysis" project aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the dynamic pulmonary imaging technique. We have proposed and evaluated a multiresolutional method with an explicit ventilation model for ventilation analysis. This paper presents a new model-based method for pulmonary perfusion analysis. According to perfusion properties, we first devise a novel mathematical function to form a perfusion model. A simple yet accurate approach is further introduced to extract cardiac systolic and diastolic phases from the heart, so that this cardiac information may be utilized to accelerate the perfusion analysis and improve its sensitivity in detecting pulmonary perfusion abnormalities. This makes perfusion analysis not only fast but also robust in computation; consequently, perfusion analysis becomes computationally feasible without using contrast media. Our clinical case studies with 52 patients show that this technique is effective for pulmonary embolism even without using contrast media, demonstrating consistent correlations with computed tomography (CT and nuclear medicine (NM studies. This fluoroscopical examination takes only about 2 seconds for perfusion study with only low radiation dose to patient, involving no preparation, no radioactive isotopes, and no contrast media.

Intra-operative protective mechanical ventilation in lung transplantation: a randomised, controlled trial.

Science.gov (United States)

Verbeek, G L; Myles, P S; Westall, G P; Lin, E; Hastings, S L; Marasco, S F; Jaffar, J; Meehan, A C

2017-08-01

Primary graft dysfunction occurs in up to 25% of patients after lung transplantation. Contributing factors include ventilator-induced lung injury, cardiopulmonary bypass, ischaemia-reperfusion injury and excessive fluid administration. We evaluated the feasibility, safety and efficacy of an open-lung protective ventilation strategy aimed at reducing ventilator-induced lung injury. We enrolled adult patients scheduled to undergo bilateral sequential lung transplantation, and randomly assigned them to either a control group (volume-controlled ventilation with 5 cmH 2 O, positive end-expiratory pressure, low tidal volumes (two-lung ventilation 6 ml.kg -1 , one-lung ventilation 4 ml.kg -1 )) or an alveolar recruitment group (regular step-wise positive end-expiratory pressure-based alveolar recruitment manoeuvres, pressure-controlled ventilation set at 16 cmH 2 O with 10 cmH 2 O positive end-expiratory pressure). Ventilation strategies were commenced from reperfusion of the first lung allograft and continued for the duration of surgery. Regular PaO 2 /F I O 2 ratios were calculated and venous blood samples collected for inflammatory marker evaluation during the procedure and for the first 24 h of intensive care stay. The primary end-point was the PaO 2 /F I O 2 ratio at 24 h after first lung reperfusion. Thirty adult patients were studied. The primary outcome was not different between groups (mean (SD) PaO 2 /F I O 2 ratio control group 340 (111) vs. alveolar recruitment group 404 (153); adjusted p = 0.26). Patients in the control group had poorer mean (SD) PaO 2 /F I O 2 ratios at the end of the surgical procedure and a longer median (IQR [range]) time to tracheal extubation compared with the alveolar recruitment group (308 (144) vs. 402 (154) (p = 0.03) and 18 (10-27 [5-468]) h vs. 15 (11-36 [5-115]) h (p = 0.01), respectively). An open-lung protective ventilation strategy during surgery for lung transplantation is feasible, safe and achieves favourable

High bias gas flows increase lung injury in the ventilated preterm lamb.

Directory of Open Access Journals (Sweden)

Katinka P Bach

Full Text Available BACKGROUND: Mechanical ventilation of preterm babies increases survival but can also cause ventilator-induced lung injury (VILI, leading to the development of bronchopulmonary dysplasia (BPD. It is not known whether shear stress injury from gases flowing into the preterm lung during ventilation contributes to VILI. METHODS: Preterm lambs of 131 days' gestation (term = 147 d were ventilated for 2 hours with a bias gas flow of 8 L/min (n = 13, 18 L/min (n = 12 or 28 L/min (n = 14. Physiological parameters were measured continuously and lung injury was assessed by measuring mRNA expression of early injury response genes and by histological analysis. Control lung tissue was collected from unventilated age-matched fetuses. Data were analysed by ANOVA with a Tukey post-hoc test when appropriate. RESULTS: High bias gas flows resulted in higher ventilator pressures, shorter inflation times and decreased ventilator efficiency. The rate of rise of inspiratory gas flow was greatest, and pulmonary mRNA levels of the injury markers, EGR1 and CTGF, were highest in lambs ventilated with bias gas flows of 18 L/min. High bias gas flows resulted in increased cellular proliferation and abnormal deposition of elastin, collagen and myofibroblasts in the lung. CONCLUSIONS: High ventilator bias gas flows resulted in increased lung injury, with up-regulation of acute early response genes and increased histological lung injury. Bias gas flows may, therefore, contribute to VILI and BPD.

Simultaneous determination of left ventricular perfusion and function

International Nuclear Information System (INIS)

Gremillet, E.; Champailler, A.; Esquerre, J.P.; Ouhayoun, E.; Coca, F.; Furber, A.; Le Jeune, J.J.

1997-01-01

Myocardial perfusion scintigraphy is a very useful tool for the diagnosis and prognosis of coronary artery disease. The evaluation of left ventricular function during stress testing in also very useful to determine the prognosis of coronary artery disease. This chapter highlights three different imaging methods to assess left ventricular function and myocardial perfusion/ The first one consists of sequential dual isotope myocardial SPECT with ECG-gating. The second concerns magnetic resonance imaging and the third explores first pass exercise ventriculography and myocardial perfusion scintigraphy simultaneously evaluated by means of 99m Tc-sestamibi. (authors)

High-resolution imaging of pulmonary ventilation and perfusion with 68Ga-VQ respiratory gated (4-D) PET/CT

International Nuclear Information System (INIS)

Callahan, Jason; Hofman, Michael S.; Siva, Shankar; Kron, Tomas; Schneider, Michal E.; Binns, David; Eu, Peter; Hicks, Rodney J.

2014-01-01

Our group has previously reported on the use of 68 Ga-ventilation/perfusion (VQ) PET/CT scanning for the diagnosis of pulmonary embolism. We describe here the acquisition methodology for 68 Ga-VQ respiratory gated (4-D) PET/CT and the effects of respiratory motion on image coregistration in VQ scanning. A prospective study was performed in 15 patients with non-small-cell lung cancer. 4-D PET and 4-D CT images were acquired using an infrared marker on the patient's abdomen as a surrogate for breathing motion following inhalation of Galligas and intravenous administration of 68 Ga-macroaggregated albumin. Images were reconstructed with phase-matched attenuation correction. The lungs were contoured on CT and PET VQ images during free-breathing (FB) and at maximum inspiration (Insp) and expiration (Exp). The similarity between PET and CT volumes was measured using the Dice coefficient (DC) comparing the following groups; (1) FB-PET/CT, (2) InspPET/InspCT, (3) ExpPET/Exp CT, and (4) FB-PET/AveCT. A repeated measures one-way ANOVA with multiple comparison Tukey tests were performed to evaluate any difference between the groups. Diaphragmatic motion in the superior-inferior direction on the 4-D CT scan was also measured. 4-D VQ scanning was successful in all patients without additional acquisition time compared to the nongated technique. The highest volume overlap was between ExpPET and ExpCT and between FB-PET and AveCT with a DC of 0.82 and 0.80 for ventilation and perfusion, respectively. This was significantly better than the DC comparing the other groups (0.78-0.79, p 68 Ga-VQ 4-D PET/CT is feasible and the blurring caused by respiratory motion is well corrected with 4-D acquisition, which principally reduces artefact at the lung bases. The images with the highest spatial overlap were the combined expiration phase or FB PET and average CT. With higher resolution than SPECT/CT, the PET/CT technique has a broad range of potential clinical applications including

Data-driven classification of ventilated lung tissues using electrical impedance tomography

International Nuclear Information System (INIS)

Gómez-Laberge, Camille; Hogan, Matthew J; Elke, Gunnar; Weiler, Norbert; Frerichs, Inéz; Adler, Andy

2011-01-01

Current methods for identifying ventilated lung regions utilizing electrical impedance tomography images rely on dividing the image into arbitrary regions of interest (ROI), manually delineating ROI, or forming ROI with pixels whose signal properties surpass an arbitrary threshold. In this paper, we propose a novel application of a data-driven classification method to identify ventilated lung ROI based on forming k clusters from pixels with correlated signals. A standard first-order model for lung mechanics is then applied to determine which ROI correspond to ventilated lung tissue. We applied the method in an experimental study of 16 mechanically ventilated swine in the supine position, which underwent changes in positive end-expiratory pressure (PEEP) and fraction of inspired oxygen (F I O 2 ). In each stage of the experimental protocol, the method performed best with k = 4 and consistently identified 3 lung tissue ROI and 1 boundary tissue ROI in 15 of the 16 subjects. When testing for changes from baseline in lung position, tidal volume, and respiratory system compliance, we found that PEEP displaced the ventilated lung region dorsally by 2 cm, decreased tidal volume by 1.3%, and increased the respiratory system compliance time constant by 0.3 s. F I O 2 decreased tidal volume by 0.7%. All effects were tested at p < 0.05 with n = 16. These findings suggest that the proposed ROI detection method is robust and sensitive to ventilation dynamics in the experimental setting

Postural lung recruitment assessed by lung ultrasound in mechanically ventilated children.

Science.gov (United States)

Tusman, Gerardo; Acosta, Cecilia M; Böhm, Stephan H; Waldmann, Andreas D; Ferrando, Carlos; Marquez, Manuel Perez; Sipmann, Fernando Suarez

2017-10-13

Atelectasis is a common finding in mechanically ventilated children with healthy lungs. This lung collapse cannot be overcome using standard levels of positive end-expiratory pressure (PEEP) and thus for only individualized lung recruitment maneuvers lead to satisfactory therapeutic results. In this short communication, we demonstrate by lung ultrasound images (LUS) the effect of a postural recruitment maneuver (P-RM, i.e., a ventilatory strategy aimed at reaerating atelectasis by changing body position under constant ventilation). Data was collected in the operating room of the Hospital Privado de Comunidad, Mar del Plata, Argentina. Three anesthetized children undergoing mechanical ventilation at constant settings were sequentially subjected to the following two maneuvers: (1) PEEP trial in the supine position PEEP was increased to 10 cmH 2 O for 3 min and then decreased to back to baseline. (2) P-RM patient position was changed from supine to the left and then to the right lateral position for 90 s each before returning to supine. The total P-RM procedure took approximately 3 min. LUS in the supine position showed similar atelectasis before and after the PEEP trial. Contrarily, atelectasis disappeared in the non-dependent lung when patients were placed in the lateral positions. Both lungs remained atelectasis free even after returning to the supine position. We provide LUS images that illustrate the concept and effects of postural recruitment in children. This maneuver has the advantage of achieving recruitment effects without the need to elevate airways pressures.

Comparison of actual tidal volume in neonatal lung model volume control ventilation using three ventilators.

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Toyama, H; Endo, Y; Ejima, Y; Matsubara, M; Kurosawa, S

2011-07-01

In neonates, small changes in tidal volumes (V(T)) may lead to complications. Previous studies have shown a significant difference between ventilator-measured tidal volume and tidal volume delivered (actual V(T)). We evaluated the accuracy of three different ventilators to deliver small V(T) during volume-controlled ventilation. We tested Servo 300, 840 ventilator and Evita 4 Neoflow ventilators with lung models simulating normal and injured neonatal lung compliance models. Gas volume delivered from the ventilator into the test circuit (V(TV)) and actual V(T) to the test lung were measured using Ventrak respiration monitors at set V(T) (30 ml). The gas volume increase of the breathing circuit was then calculated. Tidal volumes of the SV300 and PB840 in both lung models were similar to the set V(T) and the actual tidal volumes in the injured model (20.7 ml and 19.8 ml, respectively) were significantly less than that in the normal model (27.4 ml and 23.4 ml). PB840 with circuit compliance compensation could not improve the actual V(T). V(TV) of the EV4N in the normal and the injured models (37.8 ml and 46.6 ml) were markedly increased compared with set V(T), and actual V(T) were similar to set V(T) in the normal and injured model (30.2 ml and 31.9 ml, respectively). EV4N measuring V(T) close to the lung could match actual V(T) to almost the same value as the set V(T) however the gas volume of the breathing circuit was increased. If an accurate value for the patient's actual V(T) is needed, this V(T) must be measured by a sensor located between the Y-piece and the tracheal tube.

The effect of irradiation on lung function and perfusion in patients with lung cancer

International Nuclear Information System (INIS)

Abratt, Raymond P.; Willcox, Paul A.

1995-01-01

Purpose: To prospectively study the changes in lung function in patients with lung carcinoma treated with relatively high doses of irradiation. Methods and Materials: Lung function was assessed prior to and at 6 and 12 months following radiation therapy by a clinical dyspnea score, formal pulmonary function tests (lung volume spirometry and diffusion capacity) as well as an ipsilateral hemithorax lung perfusion scan. Changes in dyspnea score were evaluated by the chi-square and the Fishers exact test. Changes in formal lung function tests were compared with the t-test for dependent data and correlations with the t-test for independent data. Fifty-one patients were entered into the study. There were 42 evaluable patients at 6 months after irradiation and 22 evaluable patients at 12 months after irradiation. Results: A worsening of dyspnea score from 1 to 2, which is clinically acceptable, occurred in 50% or more of patients. However, a dyspnea score of 3, which is a serious complication, developed in only 5% of patients. The diffusion capacity (DLCO) decreased by 14% at 6 months and 12% at 12 months) (p < 0.0001). The forced vital capacity and total lung capacity decreased between 6% and 8% at 6 month and 12 months, which was statistically significant. The forced expiratory volume in 1 s decreased between 2 and 3% at 6 month and 12 months, which was not statistically significant. The ipsilateral hemithorax perfusion decreased by 17 and 20% at 6 and 12 months (p < 0.0001). There was no correlation between the initial hemithorax perfusion, or its decrease at follow up and the decrease in DLCO. Conclusion: Lung irradiation results in some loss of lung function in patients with lung cancer with a projected survival of 6 months or more. The pretreatment DLCO assessment should be useful in predicting clinical tolerance to irradiation

Perfusion lung scintigraphy in primary pulmonary hypertension

International Nuclear Information System (INIS)

Ogawa, Y.; Hayashida, K.; Uehara, T.; Shimonagata, T.; Nishimura, T.; Osaka Univ., Suita

1993-01-01

15 cases of primary pulmonary hypertension were classified into two groups by patterns of perfusion lung scintigraphy. Perfusion scintigrams showed multiple, small, ill-defined defects (mottled + ve) pattern in eight cases, and the remaining seven cases had a normal (mottled - ve) pattern. The mean pulmonary arterial pressure in patients with a mottled pattern (54 ± 10 mmHg) was higher than in those with a normal pattern (42 ± 9 mmHg, p < 0.05). There were no significant differences between the two groups in right ventricular ejection fraction, partial pressures of oxygen in the arterial blood or alveolo-arterial oxygen difference. All the patients with a mottled pattern died within 2 years following the lung scintigraphy. There was a significant difference in the survival curves between the two groups. (author)

Radionuclide ventilation-perfusion studies in pediatric respiratory diseases: 157 measurements of the distribution of ventilation and perfusion in 130 children

International Nuclear Information System (INIS)

Guillet, J.; Basse-Cathalinat, B.; Christophe, E.; Saudubray, F.

1983-01-01

Radionuclide investigations provide regional quantitative and kinetic data with a very low exposure. Results are dissonant with roentgenographic findings in 52% of cases and enhance diagnostic and prognostic accuracy. Although it provides poor quality images. The use of 133 Xe is preferable for ventilation studies to ensure correct evaluation of washout and trapping. According to the patient's age and position, 50% washout times vary from 5.6 to 8.7 seconds in the upper segments and from 5.6 to 8.5 seconds in the lower segments. Distribution of blood flow can be studied after intravenous injection of either sup(99m)Tc labelled microspheres of human albumin or 133 Xe saline solution. The former provides better quality images with studies of all incidences but may be contraindicated in cases of severe pulmonary hypertension or major right-to-left shunts. The latter allows a better sequential study. Radionuclide ventilation-perfusion studies are one of the major advances in pediatric pneumology in recent years [fr

Spatial distribution of sequential ventilation during mechanical ventilation of the uninjured lung: an argument for cyclical airway collapse and expansion

Directory of Open Access Journals (Sweden)

Altemeier William A

2010-05-01

Full Text Available Abstract Background Ventilator-induced lung injury (VILI is a recognized complication of mechanical ventilation. Although the specific mechanism by which mechanical ventilation causes lung injury remains an active area of study, the application of positive end expiratory pressure (PEEP reduces its severity. We have previously reported that VILI is spatially heterogeneous with the most severe injury in the dorsal-caudal lung. This regional injury heterogeneity was abolished by the application of PEEP = 8 cm H2O. We hypothesized that the spatial distribution of lung injury correlates with areas in which cyclical airway collapse and recruitment occurs. Methods To test this hypothesis, rabbits were mechanically ventilated in the supine posture, and regional ventilation distribution was measured under four conditions: tidal volumes (VT of 6 and 12 ml/kg with PEEP levels of 0 and 8 cm H2O. Results We found that relative ventilation was sequentially redistributed towards dorsal-caudal lung with increasing tidal volume. This sequential ventilation redistribution was abolished with the addition of PEEP. Conclusions These results suggest that cyclical airway collapse and recruitment is regionally heterogeneous and spatially correlated with areas most susceptible to VILI.

Changes in perfusion scintigraphy in the first days of heparin therapy in patients with acute pulmonary embolism

NARCIS (Netherlands)

de Groot, M. R.; Oostdijk, A. H.; Engelage, A. H.; van Marwijk Kooy, M.; Büller, H. R.

2000-01-01

Patients with suspected pulmonary embolism often receive heparin therapy for hours to days before ventilation/perfusion scintigraphy is completed. We assessed to what extent the lung scan classification and pulmonary vascular perfusion changed over a period of 2-4 days of full anticoagulant therapy.

Accuracy and Utility of Deformable Image Registration in 68Ga 4D PET/CT Assessment of Pulmonary Perfusion Changes During and After Lung Radiation Therapy

International Nuclear Information System (INIS)

Hardcastle, Nicholas; Hofman, Michael S.; Hicks, Rodney J.; Callahan, Jason; Kron, Tomas; MacManus, Michael P.; Ball, David L.; Jackson, Price; Siva, Shankar

2015-01-01

Purpose: Measuring changes in lung perfusion resulting from radiation therapy dose requires registration of the functional imaging to the radiation therapy treatment planning scan. This study investigates registration accuracy and utility for positron emission tomography (PET)/computed tomography (CT) perfusion imaging in radiation therapy for non–small cell lung cancer. Methods: 68 Ga 4-dimensional PET/CT ventilation-perfusion imaging was performed before, during, and after radiation therapy for 5 patients. Rigid registration and deformable image registration (DIR) using B-splines and Demons algorithms was performed with the CT data to obtain a deformation map between the functional images and planning CT. Contour propagation accuracy and correspondence of anatomic features were used to assess registration accuracy. Wilcoxon signed-rank test was used to determine statistical significance. Changes in lung perfusion resulting from radiation therapy dose were calculated for each registration method for each patient and averaged over all patients. Results: With B-splines/Demons DIR, median distance to agreement between lung contours reduced modestly by 0.9/1.1 mm, 1.3/1.6 mm, and 1.3/1.6 mm for pretreatment, midtreatment, and posttreatment (P<.01 for all), and median Dice score between lung contours improved by 0.04/0.04, 0.05/0.05, and 0.05/0.05 for pretreatment, midtreatment, and posttreatment (P<.001 for all). Distance between anatomic features reduced with DIR by median 2.5 mm and 2.8 for pretreatment and midtreatment time points, respectively (P=.001) and 1.4 mm for posttreatment (P>.2). Poorer posttreatment results were likely caused by posttreatment pneumonitis and tumor regression. Up to 80% standardized uptake value loss in perfusion scans was observed. There was limited change in the loss in lung perfusion between registration methods; however, Demons resulted in larger interpatient variation compared with rigid and B-splines registration. Conclusions

Radioaerosol Inhalation Lung Scan in Pulmonary Emphysema

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Jeon, Jeong Soo; Park, Yong Ha; Kyo, Chung Soo; Bahk, Yong Whee [Catholic University College of Medicine, Seoul (Korea, Republic of)

1990-07-15

Perfusion and ventilation imagings of the lung are well established procedure for diagnosing pulmonary embolism, differentiation it from chronic obstructive lung disease, and making an early detection of chronic obstructive lung disease. To evaluate the usefulness of radioaerosol inhalation imaging (RII) in chronic obstructive lung disease, especially pulmonary emphysema, we analyzed RIIs of five normal adult non-smokers, five asymptomatic smokers (age 25-42 years with the mean 36), and 21 patients with pulmonary emphysema (age 59-78 years with the mean 67). Scintigrams were obtained with radioaerosol produced by a BARC nebuliser with 15 mCi of {sup 99m}Tc-phytate. Scanning was performed in the anterior, posterior, and lateral projections after five to 10-minute inhalation of the radioaerosol on sitting position. The scans were analyzed and correlated with the results of pulmonary function studies and chest radiographs. Also lung perfusion scan with {sup 99m}Tc-MAA was performed in 12 patients. In five patients, we performed follow-up scans for the evaluation of the effects of a bronchodilator. Based on the X-ray findings and clinical symptoms, pulmonary emphysema was classified into four types: centrilobular (3 patients), panlobular (4 patients), intermediate (10 patients), and combined (4 patients). RII findings were patternized according to the type, extent, and intensity of the aerosol deposition in the central bronchial and bronchopulmonary system and lung parenchyma. 10 controls, normal five non-smokers and three asymptomatic smokers revealed homogeneous parenchymal deposition in the entire lung fields without central bronchial deposition. The remaining two of asymptomatic smokers revealed mild central airway deposition. The great majority of the patients showed either central (9/21) or combined type (10/21) of bronchopulmonary deposition and the remaining two patients peripheral bronchopulmonary deposition. Parenchymal aerosol deposition in pulmonary

Radioaerosol Inhalation Lung Scan in Pulmonary Emphysema

International Nuclear Information System (INIS)

Jeon, Jeong Soo; Park, Yong Ha; Chung Soo Kyo; Bahk, Yong Whee

1990-01-01

Perfusion and ventilation imagings of the lung are well established procedure for diagnosing pulmonary embolism, differentiation it from chronic obstructive lung disease, and making an early detection of chronic obstructive lung disease. To evaluate the usefulness of radioaerosol inhalation imaging (RII) in chronic obstructive lung disease, especially pulmonary emphysema, we analyzed RIIs of five normal adult non-smokers, five asymptomatic smokers (age 25-42 years with the mean 36), and 21 patients with pulmonary emphysema (age 59-78 years with the mean 67). Scintigrams were obtained with radioaerosol produced by a BARC nebuliser with 15 mCi of 99m Tc-phytate. Scanning was performed in the anterior, posterior, and lateral projections after five to 10-minute inhalation of the radioaerosol on sitting position. The scans were analyzed and correlated with the results of pulmonary function studies and chest radiographs. Also lung perfusion scan with 99m Tc-MAA was performed in 12 patients. In five patients, we performed follow-up scans for the evaluation of the effects of a bronchodilator. Based on the X-ray findings and clinical symptoms, pulmonary emphysema was classified into four types: centrilobular (3 patients), panlobular (4 patients), intermediate (10 patients), and combined (4 patients). RII findings were patternized according to the type, extent, and intensity of the aerosol deposition in the central bronchial and bronchopulmonary system and lung parenchyma. 10 controls, normal five non-smokers and three asymptomatic smokers revealed homogeneous parenchymal deposition in the entire lung fields without central bronchial deposition. The remaining two of asymptomatic smokers revealed mild central airway deposition. The great majority of the patients showed either central (9/21) or combined type (10/21) of bronchopulmonary deposition and the remaining two patients peripheral bronchopulmonary deposition. Parenchymal aerosol deposition in pulmonary emphysema was

TLR2 deficiency aggravates lung injury caused by mechanical ventilation

NARCIS (Netherlands)

Kuipers, Maria Theresa; Jongsma, Geartsje; Hegeman, Maria A; Tuip-de Boer, Anita M; Wolthuis, Esther K; Choi, Goda; Bresser, Paul; van der Poll, Tom; Schultz, Marcus J; Wieland, Catharina W

Innate immunity pathways are found to play an important role in ventilator-induced lung injury. We analyzed pulmonary expression of Toll-like receptor 2 (TLR2) in humans and mice and determined the role of TLR2 in the pathogenesis of ventilator-induced lung injury in mice. Toll-like receptor 2 gene

Perfusion lung scintigraphy in primary pulmonary hypertension

International Nuclear Information System (INIS)

Ogawa, Yoji; Nishimura, Tsunehiko; Kumita, Shin-ichirou; Hayashida, Kohei; Uehara, Toshiisa; Shimonagata, Tsuyoshi; Ohno, Akira

1991-01-01

Fifteen cases with primary pulmonary hypertension (PPH) were classified into two groups by using the perfusion lung scan pattern. Eight cases had multiple, small, ill-defined defects (mottled pattern), and remaining seven cases had no mottled pattern. These two groups were compared with mean pulmonary arterial pressure (mean PAP), right ventricular ejection fraction (RVEF), blood gas at room air (PaO 2 ), and alveolar-arterial O 2 difference (A-aDo 2 ). The cases with mottled pattern showed a significant increase in mean PAP. There were no significant differences in RVEF, PaO 2 , and A-aDo 2 , between the groups. The survival rate of the patients with mottled pattern was significantly lower than that without mottled pattern (p<0.05). We concluded that perfusion lung scan is very useful for evaluation of the prognosis in primary pulmonary hypertension. (author)

Contrast-enhanced 3D MRI of lung perfusion in children with cystic fibrosis - initial results

International Nuclear Information System (INIS)

Eichinger, Monika; Puderbach, Michael; Zuna, Ivan; Kauczor, Hans-Ulrich; Fink, Christian; Gahr, Julie; Mueller, Frank-Michael; Ley, Sebastian; Plathow, Christian; Tuengerthal, Siegfried

2006-01-01

This paper is a feasibility study of magnetic resonance imaging (MRI) of lung perfusion in children with cystic fibrosis (CF) using contrast-enhanced 3D MRI. Correlation assessment of perfusion changes with structural abnormalities. Eleven CF patients (9 f, 2 m; median age 16 years) were examined at 1.5 T. Morphology: HASTE coronal, transversal (TR/TE/α/ST: 600 ms/28 ms/180 /6 mm), breath-hold 18 s. Perfusion: Time-resolved 3D GRE pulse sequence (FLASH, TE/TR/α: 0.8/1.9 ms/40 ), parallel imaging (GRAPPA, PAT 2). Twenty-five data sets were acquired after intravenous injection of 0.1 mmol/kg body weight of gadodiamide, 3-5 ml/s. A total of 198 lung segments were analyzed by two radiologists in consensus and scored for morphological and perfusion changes. Statistical analysis was performed by Mantel-Haenszel chi-square test. Results showed that perfusion defects were observed in all patients and present in 80% of upper, and 39% of lower lobes. Normal lung parenchyma showed homogeneous perfusion (86%, P<0.0001). Severe morphological changes led to perfusion defects (97%, P<0.0001). Segments with moderate morphological changes showed normal (53%) or impaired perfusion (47%). In conclusion, pulmonary perfusion is easy to judge in segments with normal parenchyma or severe changes. In moderately damaged segments, MRI of lung perfusion may help to better assess actual functional impairment. Contrast-enhanced 3D MRI of lung perfusion has the potential for early vascular functional assessment and therapy control in CF patients. (orig.)

Low tidal volume and high positive end-expiratory pressure mechanical ventilation results in increased inflammation and ventilator-associated lung injury in normal lungs.

Science.gov (United States)

Hong, Caron M; Xu, Da-Zhong; Lu, Qi; Cheng, Yunhui; Pisarenko, Vadim; Doucet, Danielle; Brown, Margaret; Aisner, Seena; Zhang, Chunxiang; Deitch, Edwin A; Delphin, Ellise

2010-06-01

Protective mechanical ventilation with low tidal volume (Vt) and low plateau pressure reduces mortality and decreases the length of mechanical ventilation in patients with acute respiratory distress syndrome. Mechanical ventilation that will protect normal lungs during major surgical procedures of long duration may improve postoperative outcomes. We performed an animal study comparing 3 ventilation strategies used in the operating room in normal lungs. We compared the effects on pulmonary mechanics, inflammatory mediators, and lung tissue injury. Female pigs were randomized into 3 groups. Group H-Vt/3 (n = 6) was ventilated with a Vt of 15 mL/kg predicted body weight (PBW)/positive end-expiratory pressure (PEEP) of 3 cm H(2)O, group L-Vt/3 (n = 6) with a Vt of 6 mL/kg PBW/PEEP of 3 cm H(2)O, and group L-Vt/10 (n = 6) with a Vt of 6 mL/kg PBW/PEEP of 10 cm H(2)O, for 8 hours. Hemodynamics, airway mechanics, arterial blood gases, and inflammatory markers were monitored. Bronchoalveolar lavage (BAL) was analyzed for inflammatory markers and protein concentration. The right lower lobe was assayed for mRNA of specific cytokines. The right lower lobe and right upper lobe were evaluated histologically. In contrast to groups H-Vt/3 and L-Vt/3, group L-Vt/10 exhibited a 6-fold increase in inflammatory mediators in BAL (P ventilation with high PEEP resulted in increased production of inflammatory markers. Low PEEP resulted in lower levels of inflammatory markers. High Vt/low PEEP resulted in less histologic lung injury.

Increasing the inspiratory time and I:E ratio during mechanical ventilation aggravates ventilator-induced lung injury in mice.

Science.gov (United States)

Müller-Redetzky, Holger C; Felten, Matthias; Hellwig, Katharina; Wienhold, Sandra-Maria; Naujoks, Jan; Opitz, Bastian; Kershaw, Olivia; Gruber, Achim D; Suttorp, Norbert; Witzenrath, Martin

2015-01-28

Lung-protective ventilation reduced acute respiratory distress syndrome (ARDS) mortality. To minimize ventilator-induced lung injury (VILI), tidal volume is limited, high plateau pressures are avoided, and positive end-expiratory pressure (PEEP) is applied. However, the impact of specific ventilatory patterns on VILI is not well defined. Increasing inspiratory time and thereby the inspiratory/expiratory ratio (I:E ratio) may improve oxygenation, but may also be harmful as the absolute stress and strain over time increase. We thus hypothesized that increasing inspiratory time and I:E ratio aggravates VILI. VILI was induced in mice by high tidal-volume ventilation (HVT 34 ml/kg). Low tidal-volume ventilation (LVT 9 ml/kg) was used in control groups. PEEP was set to 2 cm H2O, FiO2 was 0.5 in all groups. HVT and LVT mice were ventilated with either I:E of 1:2 (LVT 1:2, HVT 1:2) or 1:1 (LVT 1:1, HVT 1:1) for 4 hours or until an alternative end point, defined as mean arterial blood pressure below 40 mm Hg. Dynamic hyperinflation due to the increased I:E ratio was excluded in a separate group of animals. Survival, lung compliance, oxygenation, pulmonary permeability, markers of pulmonary and systemic inflammation (leukocyte differentiation in lung and blood, analyses of pulmonary interleukin-6, interleukin-1β, keratinocyte-derived chemokine, monocyte chemoattractant protein-1), and histopathologic pulmonary changes were analyzed. LVT 1:2 or LVT 1:1 did not result in VILI, and all individuals survived the ventilation period. HVT 1:2 decreased lung compliance, increased pulmonary neutrophils and cytokine expression, and evoked marked histologic signs of lung injury. All animals survived. HVT 1:1 caused further significant worsening of oxygenation, compliance and increased pulmonary proinflammatory cytokine expression, and pulmonary and blood neutrophils. In the HVT 1:1 group, significant mortality during mechanical ventilation was observed. According to the "baby lung

Clinical assessment of mean washout time and lung functional image by ventilatory steady state measurement with /sup 133/Xe

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Kimura, K; Hasegawa, T; Watanabe, H; Hasegawa, S; Oshima, M [Tsukuba Univ., Sakura, Ibaraki (Japan)

1981-04-01

Ventilatory steady state measurement with /sup 133/Xe, using Ventil-Con (Radx) and a large area scintillation camera (Searle, LFOV) combined with a mini-computer system (Shimadzu, Scintipac 230) was employed to evaluate regional pulmonary function of 94 patients with chronic obstructive lung disease (COLD), fibrosis, carcinoma and other lung diseases. In the patients with COLD, mean washout times (anti t) were markedly prolonged in whole lung fields (anti m 130 +- 33 sec.) and ventilation indices (V*/V) (*: radical) and perfusion indices (Q*/V) (*: radical) were reduced in regional zones, especially in bilateral lower lung zones. For the patients with lung fibrosis, anti t values were short and the distribution of ventilation indices were uniform, and in contrast perfusion indices were reduced in the lower lung fields. In the area most affected by carcinoma, lung volumes (V) were reduced in parallel with the regional ventilation (V*) (*: radical) and perfusion (Q*) (*: radical). As the tumor approached the hilum, the relative ventilation and perfusion of cancerous side decreased remarkably in patients with obstructive findings on bronchoscopy. The mean washout times (anti t) for /sup 133/Xe, calculated by a modified height over area method without background subtraction, were significantly longer than indicated by the data yielded by the least squares curve fitting of initial washout curve after background subtraction. Although the accuracy of these data was limited, it appeared that the prolonged anti t is a good parameter of regional ventilatory disturbance because significant correlations were found between the whole lung anti t in patients with lung diseases and their FEV 1.0% r = -0.66, RV/TLC r = 0.64, % TLC r = 0.43, PaCO/sub 2/ r = 0.41, PaO/sub 2/ r = -0.35.

Pressure dynamic characteristics of pressure controlled ventilation system of a lung simulator.

Science.gov (United States)

Shi, Yan; Ren, Shuai; Cai, Maolin; Xu, Weiqing; Deng, Qiyou

2014-01-01

Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems.

A comparison of conventional surfactant treatment and partial liquid ventilation on the lung volume of injured ventilated small lungs

International Nuclear Information System (INIS)

Proquitté, Hans; Hartenstein, Sebastian; Wauer, Roland R; Schmalisch, Gerd; Koelsch, Uwe; Rüdiger, Mario

2013-01-01

As an alternative to surfactant therapy (ST), partial liquid ventilation (PLV) with perfluorocarbons (PFC) has been considered as a treatment for acute lung injury (ALI) in newborns. The instilled PFC is much heavier than the instilled surfactant and the aim of this study was to investigate whether PLV, compared to ST, increases the end-expiratory volume of the lung (V L ). Fifteen newborn piglets (age <12 h, mean weight 678 g) underwent saline lung lavage to achieve a surfactant depletion. Thereafter animals were randomized to PLV (n = 8), receiving PFC PF5080 (3M, Germany) at 30 mL kg −1 , and ST (n = 7) receiving 120 mg Curosurf®. Blood gases, hemodynamics and static compliance were measured initially (baseline), immediately after ALI, and after 240 min mechanical ventilation with either technique. Subsequently all piglets were killed; the lungs were removed in toto and frozen in liquid N 2 . After freeze-drying the lungs were cut into lung cubes (LCs) with edge lengths of 0.7 cm, to calculate V L . All LCs were weighed and the density of the dried lung tissue was calculated. No statistically significant differences between treatment groups PLV and ST (means ± SD) were noted in body weight (676 ± 16 g versus 679 ± 17 g; P = 0.974) or lung dry weight (1.64 ± 0.29 g versus 1.79 ± 0.48 g; P = 0.48). Oxygenation index and ventilatory efficacy index did not differ significantly between both groups at any time. V L (34.28 ± 6.13 mL versus 26.22 ± 8.1 mL; P < 0.05) and the density of the dried lung tissue (48.07 ± 5.02 mg mL −1 versus 69.07 ± 5.30 mg mL −1 ; P < 0.001), however, differed significantly between the PLV and ST groups. A 4 h PLV treatment of injured ventilated small lungs increased V L by 30% and decreased lung density by 31% compared to ST treatment, indicating greater lung distension after PLV compared to ST. (paper)

Graft downsizing during ex vivo lung perfusion: case report and technical notes.

Science.gov (United States)

Nosotti, M; Rosso, L; Mendogni, P; Tosi, D; Palleschi, A; Righi, I; Froio, S; Valenza, F; Santambrogio, L

2014-09-01

Among patients with respiratory insufficiency awaiting lung transplantation, small adult patients have a lower opportunity of receiving size-matched pulmonary grafts, because of the shortage of donors, particularly those of small size. Reducing the size of an oversized graft is one of the methods to increase the donor pool; similarly, ex vivo lung perfusion is an emerging technique aimed toward the same purpose. We describe how we combined the 2 techniques (lobar transplantation plus contralateral nonanatomic graft reduction during ex vivo lung perfusion) to overcome graft shortage in a clinical case. For the 1st time, this case report demonstrates that surgical manipulation during ex vivo lung perfusion does not affect the functional improvement in a lung previously judged to be not suitable for transplantation. The 6-month follow-up results are similar to those of standard bilateral lung transplantation. Copyright © 2014 Elsevier Inc. All rights reserved.

Metabolic acidosis may be as protective as hypercapnic acidosis in an ex-vivo model of severe ventilator-induced lung injury: a pilot study.

Science.gov (United States)

Kapetanakis, Theodoros; Siempos, Ilias I; Metaxas, Eugenios I; Kopterides, Petros; Agrogiannis, George; Patsouris, Efstratios; Lazaris, Andreas C; Stravodimos, Konstantinos G; Roussos, Charis; Armaganidis, Apostolos

2011-04-13

There is mounting experimental evidence that hypercapnic acidosis protects against lung injury. However, it is unclear if acidosis per se rather than hypercapnia is responsible for this beneficial effect. Therefore, we sought to evaluate the effects of hypercapnic (respiratory) versus normocapnic (metabolic) acidosis in an ex vivo model of ventilator-induced lung injury (VILI). Sixty New Zealand white rabbit ventilated and perfused heart-lung preparations were used. Six study groups were evaluated. Respiratory acidosis (RA), metabolic acidosis (MA) and normocapnic-normoxic (Control - C) groups were randomized into high and low peak inspiratory pressures, respectively. Each preparation was ventilated for 1 hour according to a standardized ventilation protocol. Lung injury was evaluated by means of pulmonary edema formation (weight gain), changes in ultrafiltration coefficient, mean pulmonary artery pressure changes as well as histological alterations. HPC group gained significantly greater weight than HPMA, HPRA and all three LP groups (P = 0.024), while no difference was observed between HPMA and HPRA groups regarding weight gain. Neither group differ on ultrafiltration coefficient. HPMA group experienced greater increase in the mean pulmonary artery pressure at 20 min (P = 0.0276) and 40 min (P = 0.0012) compared with all other groups. Histology scores were significantly greater in HP vs. LP groups (p < 0.001). In our experimental VILI model both metabolic acidosis and hypercapnic acidosis attenuated VILI-induced pulmonary edema implying a mechanism other than possible synergistic effects of acidosis with CO2 for VILI attenuation.

The distribution of lung damage in children with cystic fibrosis and its relationship to colonisation with Pseudomonas aeroginosa

International Nuclear Information System (INIS)

Evans, I.; Hambleton, G.; Mann, N.; Brown, J.

1987-01-01

Ventilation-perfusion lung scans were performed with 81m Kr inhalation and 99m Tc-albumin injection in 33 children with cystic fibrosis. It was found that both ventilation and perfusion scans yielded more information than radiographs of the chest in assessing lung damage. Using a scoring system, it was demonstrated by statistical methods that in the worst affected patients the disease was worse in the upper zones of the lungs, where changes were not detectable on chest radiographs. Pseudomonas was present in the sputum of these patients. (orig.)

Accuracy and Utility of Deformable Image Registration in {sup 68}Ga 4D PET/CT Assessment of Pulmonary Perfusion Changes During and After Lung Radiation Therapy

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Hardcastle, Nicholas, E-mail: nick.hardcastle@gmail.com [Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne (Australia); Centre for Medical Radiation Physics, University of Wollongong, Wollongong (Australia); Hofman, Michael S. [Molecular Imaging, Centre for Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne (Australia); Hicks, Rodney J. [Molecular Imaging, Centre for Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne (Australia); Department of Medicine, University of Melbourne, Melbourne (Australia); Callahan, Jason [Molecular Imaging, Centre for Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne (Australia); Kron, Tomas [Department of Medical Imaging and Radiation Sciences, Monash University, Clayton (Australia); The Sir Peter MacCallum Department of Oncology, Melbourne University, Victoria (Australia); MacManus, Michael P.; Ball, David L. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne (Australia); The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne (Australia); Jackson, Price [Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne (Australia); Siva, Shankar [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne (Australia)

2015-09-01

Purpose: Measuring changes in lung perfusion resulting from radiation therapy dose requires registration of the functional imaging to the radiation therapy treatment planning scan. This study investigates registration accuracy and utility for positron emission tomography (PET)/computed tomography (CT) perfusion imaging in radiation therapy for non–small cell lung cancer. Methods: {sup 68}Ga 4-dimensional PET/CT ventilation-perfusion imaging was performed before, during, and after radiation therapy for 5 patients. Rigid registration and deformable image registration (DIR) using B-splines and Demons algorithms was performed with the CT data to obtain a deformation map between the functional images and planning CT. Contour propagation accuracy and correspondence of anatomic features were used to assess registration accuracy. Wilcoxon signed-rank test was used to determine statistical significance. Changes in lung perfusion resulting from radiation therapy dose were calculated for each registration method for each patient and averaged over all patients. Results: With B-splines/Demons DIR, median distance to agreement between lung contours reduced modestly by 0.9/1.1 mm, 1.3/1.6 mm, and 1.3/1.6 mm for pretreatment, midtreatment, and posttreatment (P<.01 for all), and median Dice score between lung contours improved by 0.04/0.04, 0.05/0.05, and 0.05/0.05 for pretreatment, midtreatment, and posttreatment (P<.001 for all). Distance between anatomic features reduced with DIR by median 2.5 mm and 2.8 for pretreatment and midtreatment time points, respectively (P=.001) and 1.4 mm for posttreatment (P>.2). Poorer posttreatment results were likely caused by posttreatment pneumonitis and tumor regression. Up to 80% standardized uptake value loss in perfusion scans was observed. There was limited change in the loss in lung perfusion between registration methods; however, Demons resulted in larger interpatient variation compared with rigid and B-splines registration

Lung perfusion scintigraphy in the diagnosis of peripheral pulmonary stenosis in patients after repair of Fallot tetralogy

International Nuclear Information System (INIS)

Sabiniewicz, R.; Chojnicki, M.; Alszewicz-Baranowska, J.; Erecinski, J.; Romanowicz, G.; Lass, P.; Bandurski, T.

2002-01-01

The frequency of peripheral pulmonary artery stenosis in patients after surgical repair of tetralogy of Fallot (TOF) ranges from 20 to 40%. This can be either primary or secondary to the surgical intervention. The influence of resulting lung perfusion alterations on the life quality of patients is difficult to predict. The aim of this study was to compare the utility of the diagnostic procedures in this group of patients, with particular focus on lung perfusion scintigraphy. This study comprised 104 patients who underwent repair of TOF at ages from 5 months to 25 years. The patients have been followed up for from 4.2 to 25 years. On the basis of chest X-ray peripheral pulmonary artery stenosis was suspected in 11 patients, in 12 on the basis of echocardiography examination. Lung perfusion scintigraphy has been performed on 87 patients. The disturbances in lung perfusion (mostly in the left lung) were show by means of lung perfusion scintigraphy in 43 (49%) of patients. In 27 of them heart catheterisation has been performed. Angiography revealed stenosis of the lung artery branch in 15/43 (34.9%) patients with abnormal perfusion lung scan and in 4/44 (9%) in patients with normal perfusion lung scan. Intervention procedures were carried out on 10 patients. Lung perfusion scintigraphy may prove a valuable, non-invasive screening tool in the assessment of patients after TOF repair, although both false-negative and false positive results may happen. Therefore, it should play an auxiliary role together with other diagnostic modalities. (author)

Measurement of lung volume by lung perfusion scanning using SPECT and prediction of postoperative respiratory function

International Nuclear Information System (INIS)

Andou, Akio; Shimizu, Nobuyosi; Maruyama, Shuichiro

1992-01-01

Measurement of lung volume by lung perfusion scanning using single photon emission computed tomography (SPECT) and its usefulness for the prediction of respiratory function after lung resection were investigated. The lung volumes calculated in 5 patients by SPECT (threshold level 20%) using 99m Tc-macroaggregated albumin (MAA), related very closely to the actually measured lung volumes. This results prompted us to calculate the total lung volume and the volume of the lobe to be resected in 18 patients with lung cancer by SPECT. Based on the data obtained, postoperative respiratory function was predicted. The predicted values of forced vital capacity (FVC), forced expiratory volume (FEV 1.0 ), and maximum vital volume (MVV) showed closer correlations with the actually measured postoperative values (FVC, FEV 1.0 , MVV : r=0.944, r=0.917, r=0.795 respectively), than the values predicted by the ordinary lung perfusion scanning. This method facilitates more detailed evaluation of local lung function on a lobe-by-lobe basis, and can be applied clinically to predict postoperative respiratory function. (author)

SU-E-J-86: Lobar Lung Function Quantification by PET Galligas and CT Ventilation Imaging in Lung Cancer Patients

International Nuclear Information System (INIS)

Eslick, E; Kipritidis, J; Keall, P; Bailey, D; Bailey, E

2014-01-01

Purpose: The purpose of this study was to quantify the lobar lung function using the novel PET Galligas ([68Ga]-carbon nanoparticle) ventilation imaging and the investigational CT ventilation imaging in lung cancer patients pre-treatment. Methods: We present results on our first three lung cancer patients (2 male, mean age 78 years) as part of an ongoing ethics approved study. For each patient a PET Galligas ventilation (PET-V) image and a pair of breath hold CT images (end-exhale and end-inhale tidal volumes) were acquired using a Siemens Biograph PET CT. CT-ventilation (CT-V) images were created from the pair of CT images using deformable image registration (DIR) algorithms and the Hounsfield Unit (HU) ventilation metric. A comparison of ventilation quantification from each modality was done on the lobar level and the voxel level. A Bland-Altman plot was used to assess the difference in mean percentage contribution of each lobe to the total lung function between the two modalities. For each patient, a voxel-wise Spearmans correlation was calculated for the whole lungs between the two modalities. Results: The Bland-Altman plot demonstrated strong agreement between PET-V and CT-V for assessment of lobar function (r=0.99, p<0.001; range mean difference: −5.5 to 3.0). The correlation between PET-V and CT-V at the voxel level was moderate(r=0.60, p<0.001). Conclusion: This preliminary study on the three patients data sets demonstrated strong agreement between PET and CT ventilation imaging for the assessment of pre-treatment lung function at the lobar level. Agreement was only moderate at the level of voxel correlations. These results indicate that CT ventilation imaging has potential for assessing pre-treatment lobar lung function in lung cancer patients

Concentration of (+/-)-propranolol in isolated, perfused lungs of rat.

Science.gov (United States)

Dollery, C T; Junod, A F

1976-01-01

1 The metabolism and the accumulation of (+/-)-propranolol have been studied in isolated lungs of the rat, perfused with an artificial medium. 2 Little or no metabolism took place during the perfusion periods (up to 10 minutes). 3 Accumulation was observed with high tissue/medium ratios for substrate concentrations of 0.2 muM to 1 mM; there was evidence for saturability, but no real plateau could be seen. The presence of two binding sites with different affinities was established. 4 Cold greatly inhibited the accumulation process at low substrate concentrations, but had no effect at 1 mM propranolol. 5 Inhibition of accumulation was measured in the presence of imipramine, desmethylimipramine, nortryptiline, chlorpromazine and of Na+-free medium. Cocaine, 5-hydroxytryptamine and noradrenaline had no effect. Lidocaine enhanced the accumulation process. Release of previously bound propranolol was accelerated in the presence of propranolol and imipramine, unaffected by a Na+-free medium and decreased by cold and by lidocaine. 6 Experiments on lung tissue slices yielded qualitatively similar results to those obtained with perfused lungs. Ouabain and KCN had no or little effect on propranolol accumulation. PMID:1276542

Information for the diagnosis of broncho-pulmonary diseases obtained by the combined use of perfusion lung scintigraphy and selective bronchial arteriography

International Nuclear Information System (INIS)

Wouamba Foning, Michel.

1976-01-01

Our study is limited to perfusion lung scintigraphy and deals with the following in turn: - radioisotopes and their conditioning, - detection and recording equipment, - results and limits of the method. The tracers used here were radioiodine-labelled human albumin macro-aggregates and more especially technetium-labelled microspheres. Scintigraphy, which visualizes or charts the local distribution of radioactive indicators, is carried out with two kinds of apparatus, scanners and scintillation cameras. The information acquired may be accurately analysed at the same time owing to modern data processing systems. The interpretation of radiotracer lung transit curves made by several authors is not very useful for our work, consequently we have kept to the analysis of images obtained by the Anger camera or similar instruments. The Anger scintillation camera seems to be well suited to isotopic lung exploration providing morphological and functional data simultaneously. Perfusion lung scintigraphy, which reflects the quality of lung circulation at the capillary level, appears to be a valuable asset in the diagnostic approach to certain chest X-ray images. The technique is fast, painless, neat, harmless and almost never contra-indicated. However like other techniques it cannot solve every problem on its own. Under these conditions, we must admit, on weighing up the results of this study, that perfusion lung scintigraphy had to be followed in most cases by selective bronchial arteriography [fr

Pressure Dynamic Characteristics of Pressure Controlled Ventilation System of a Lung Simulator

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Yan Shi

2014-01-01

Full Text Available Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems.

Pressure Dynamic Characteristics of Pressure Controlled Ventilation System of a Lung Simulator

Science.gov (United States)

Shi, Yan; Ren, Shuai; Cai, Maolin; Xu, Weiqing; Deng, Qiyou

2014-01-01

Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems. PMID:25197318

Low tidal volume ventilation ameliorates left ventricular dysfunction in mechanically ventilated rats following LPS-induced lung injury.

Science.gov (United States)

Cherpanath, Thomas G V; Smeding, Lonneke; Hirsch, Alexander; Lagrand, Wim K; Schultz, Marcus J; Groeneveld, A B Johan

2015-10-07

High tidal volume ventilation has shown to cause ventilator-induced lung injury (VILI), possibly contributing to concomitant extrapulmonary organ dysfunction. The present study examined whether left ventricular (LV) function is dependent on tidal volume size and whether this effect is augmented during lipopolysaccharide(LPS)-induced lung injury. Twenty male Wistar rats were sedated, paralyzed and then randomized in four groups receiving mechanical ventilation with tidal volumes of 6 ml/kg or 19 ml/kg with or without intrapulmonary administration of LPS. A conductance catheter was placed in the left ventricle to generate pressure-volume loops, which were also obtained within a few seconds of vena cava occlusion to obtain relatively load-independent LV systolic and diastolic function parameters. The end-systolic elastance / effective arterial elastance (Ees/Ea) ratio was used as the primary parameter of LV systolic function with the end-diastolic elastance (Eed) as primary LV diastolic function. Ees/Ea decreased over time in rats receiving LPS (p = 0.045) and high tidal volume ventilation (p = 0.007), with a lower Ees/Ea in the rats with high tidal volume ventilation plus LPS compared to the other groups (p tidal volume ventilation without LPS (p = 0.223). A significant interaction (p tidal ventilation and LPS for Ees/Ea and Eed, and all rats receiving high tidal volume ventilation plus LPS died before the end of the experiment. Low tidal volume ventilation ameliorated LV systolic and diastolic dysfunction while preventing death following LPS-induced lung injury in mechanically ventilated rats. Our data advocates the use of low tidal volumes, not only to avoid VILI, but to avert ventilator-induced myocardial dysfunction as well.

Preserving Functional Lung Using Perfusion Imaging and Intensity-Modulated Radiation Therapy for Advanced-Stage Non-Small Cell Lung Cancer

International Nuclear Information System (INIS)

Shioyama, Yoshiyuki; Jang, Si Young; Liu, H. Helen; Guerrero, Thomas; Wang, Xuanmin; Gayed, Isis W.; Erwin, William D.; Liao, Zhongxing; Chang, Joe Y.; Jeter, Melenda; Yaremko, Brian P.; Borghero, Yerko O.; Cox, James D.; Komaki, Ritsuko; Mohan, Radhe

2007-01-01

Purpose: To assess quantitatively the impact of incorporating functional lung imaging into intensity-modulated radiation therapy planning for locally advanced non-small cell lung cancer (NSCLC). Methods and Materials: Sixteen patients with advanced-stage NSCLC who underwent radiotherapy were included in this study. Before radiotherapy, each patient underwent lung perfusion imaging with single-photon-emission computed tomography and X-ray computed tomography (SPECT-CT). The SPECT-CT was registered with simulation CT and was used to segment the 50- and 90-percentile hyperperfusion lung (F50 lung and F90 lung). Two IMRT plans were designed and compared in each patient: an anatomic plan using simulation CT alone and a functional plan using SPECT-CT in addition to the simulation CT. Dosimetric parameters of the two types of plans were compared in terms of tumor coverage and avoidance of normal tissues. Results: In incorporating perfusion information in IMRT planning, the median reductions in the mean doses to the F50 and F90 lung in the functional plan were 2.2 and 4.2 Gy, respectively, compared with those in the anatomic plans. The median reductions in the percentage of volume irradiated with >5 Gy, >10 Gy, and >20 Gy in the functional plans were 7.1%, 6.0%, and 5.1%, respectively, for F50 lung, and 11.7%, 12.0%, and 6.8%, respectively, for F90 lung. A greater degree of sparing of the functional lung was achieved for patients with large perfusion defects compared with those with relatively uniform perfusion distribution. Conclusion: Function-guided IMRT planning appears to be effective in preserving functional lung in locally advanced-stage NSCLC patients

Perioperative lung protective ventilation in obese patients

OpenAIRE

Fernandez-Bustamante, Ana; Hashimoto, Soshi; Serpa Neto, Ary; Moine, Pierre; Vidal Melo, Marcos F; Repine, John E

2015-01-01

The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increa...

Predicting the lung compliance of mechanically ventilated patients via statistical modeling

International Nuclear Information System (INIS)

Ganzert, Steven; Kramer, Stefan; Guttmann, Josef

2012-01-01

To avoid ventilator associated lung injury (VALI) during mechanical ventilation, the ventilator is adjusted with reference to the volume distensibility or ‘compliance’ of the lung. For lung-protective ventilation, the lung should be inflated at its maximum compliance, i.e. when during inspiration a maximal intrapulmonary volume change is achieved by a minimal change of pressure. To accomplish this, one of the main parameters is the adjusted positive end-expiratory pressure (PEEP). As changing the ventilator settings usually produces an effect on patient's lung mechanics with a considerable time delay, the prediction of the compliance change associated with a planned change of PEEP could assist the physician at the bedside. This study introduces a machine learning approach to predict the nonlinear lung compliance for the individual patient by Gaussian processes, a probabilistic modeling technique. Experiments are based on time series data obtained from patients suffering from acute respiratory distress syndrome (ARDS). With a high hit ratio of up to 93%, the learned models could predict whether an increase/decrease of PEEP would lead to an increase/decrease of the compliance. However, the prediction of the complete pressure–volume relation for an individual patient has to be improved. We conclude that the approach is well suitable for the given problem domain but that an individualized feature selection should be applied for a precise prediction of individual pressure–volume curves. (paper)

TU-A-12A-02: Novel Lung Ventilation Imaging with Single Energy CT After Single Inhalation of Xenon: Comparison with SPECT Ventilation Images

Energy Technology Data Exchange (ETDEWEB)

Negahdar, M [Stanford University School of Medicine, Stanford, CA (United States); Yamamoto, T [UC Davis School of Medicine, Sacramento, CA (United States); Shultz, D; Gable, L; Shan, X; Mittra, E; Loo, B; Maxim, P [Stanford University, Stanford, CA (United States); Diehn, M [Stanford University, Palo Alto, CA (United States)

2014-06-15

Purpose: We propose a novel lung functional imaging method to determine the spatial distribution of xenon (Xe) gas in a single inhalation as a measure of regional ventilation. We compare Xe-CT ventilation to single-photon emission CT (SPECT) ventilation, which is the current clinical reference. Regional lung ventilation information may be useful for the diagnosis and monitoring of pulmonary diseases such as COPD, radiotherapy planning, and assessing the progression of toxicity after radiation therapy. Methods: In an IRB-approved clinical study, Xe-CT and SPECT ventilation scans were acquired for three patients including one patient with severe emphysema and two lung cancer patients treated with radiotherapy. For Xe- CT, we acquired two breath-hold single energy CT images of the entire lung with inspiration of 100% O2 and a mixture of 70% Xe and 30% O2, respectively. A video biofeedback system was used to achieve reproducible breath-holds. We used deformable image registration to align the breathhold images with each other to accurately subtract them, producing a map of the distribution of Xe as a surrogate of lung ventilation. We divided each lung into twelve parts and correlated the Hounsfield unit (HU) enhancement at each part with the SPECT ventilation count of the corresponding part of the lung. Results: The mean of the Pearson linear correlation coefficient values between the Xe-CT and ventilation SPECT count for all three patients were 0.62 (p<0.01). The Xe-CT image had a higher resolution than SPECT, and did not show central airway deposition artifacts that were present in the SPECT image. Conclusion: We developed a rapid, safe, clinically practical, and potentially widely accessible method for regional lung functional imaging. We demonstrated strong correlations between the Xe-CT ventilation image and SPECT ventilation image as the clinical reference. This ongoing study will investigate more patients to confirm this finding.

TU-A-12A-02: Novel Lung Ventilation Imaging with Single Energy CT After Single Inhalation of Xenon: Comparison with SPECT Ventilation Images

International Nuclear Information System (INIS)

Negahdar, M; Yamamoto, T; Shultz, D; Gable, L; Shan, X; Mittra, E; Loo, B; Maxim, P; Diehn, M

2014-01-01

Purpose: We propose a novel lung functional imaging method to determine the spatial distribution of xenon (Xe) gas in a single inhalation as a measure of regional ventilation. We compare Xe-CT ventilation to single-photon emission CT (SPECT) ventilation, which is the current clinical reference. Regional lung ventilation information may be useful for the diagnosis and monitoring of pulmonary diseases such as COPD, radiotherapy planning, and assessing the progression of toxicity after radiation therapy. Methods: In an IRB-approved clinical study, Xe-CT and SPECT ventilation scans were acquired for three patients including one patient with severe emphysema and two lung cancer patients treated with radiotherapy. For Xe- CT, we acquired two breath-hold single energy CT images of the entire lung with inspiration of 100% O2 and a mixture of 70% Xe and 30% O2, respectively. A video biofeedback system was used to achieve reproducible breath-holds. We used deformable image registration to align the breathhold images with each other to accurately subtract them, producing a map of the distribution of Xe as a surrogate of lung ventilation. We divided each lung into twelve parts and correlated the Hounsfield unit (HU) enhancement at each part with the SPECT ventilation count of the corresponding part of the lung. Results: The mean of the Pearson linear correlation coefficient values between the Xe-CT and ventilation SPECT count for all three patients were 0.62 (p<0.01). The Xe-CT image had a higher resolution than SPECT, and did not show central airway deposition artifacts that were present in the SPECT image. Conclusion: We developed a rapid, safe, clinically practical, and potentially widely accessible method for regional lung functional imaging. We demonstrated strong correlations between the Xe-CT ventilation image and SPECT ventilation image as the clinical reference. This ongoing study will investigate more patients to confirm this finding

Effects of smoking on lung uptake of 201Tl during exercise myocardial perfusion imaging

International Nuclear Information System (INIS)

Ouyang Wei; He Guorong; Liu Jinhua

2004-01-01

Objective: To investigate the influence of smoking on lung uptake of 201 Tl during myocardial perfusion imaging. Methods: Ninety-two healthy subjects, with normal 201 Tl myocardial perfusion imaging findings but no evidence of left ventricular hypertrophy and pulmonary disease, were divided into three groups, smoker, nonsmoker and quitted smoker groups. Exercise/delay 201 Tl myocardial perfusion imaging was performed on all subjects included. Lung/heart ratio was defined on the anterior planar image obtained during exercise tomography. Results: Both the lung/heart ratios during exercise in smoker (0.40 ± 0.07, F=10.635, P 201 Tl lung/heart ratios in smokers are higher than in nonsmokers and this must be kept in mind when 201 Tl lung/heart ratios are used clinically, even in quitted smokers

Use of sup(81m)Kr gas for the measurement of absolute regional lung ventilation

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Nosil, J; Bajzer, Z; Spaventi, S [Mladen Stojanovic Clinical Hospital, Zagreb (Yugoslavia). Dept. of Nuclear Medicine and Oncology; Institut Rudjer Boskovic, Zagreb (Yugoslavia))

1977-02-01

In this paper a new method of using sup(81m)Kr for the measurement of specific absolute regional lung ventilation is described. Experimental data suitable for the calculation of quantitative regional ventilation are provided using an adequate respiratory system for sup(81m)Kr dosage and a scintillation gamma camera interfaced to a digital computer. A simple mathematical lung model for the inhalation of sup(81m)Kr is used to determine the specific ventilation and the parameters proportional to the ventilation for the whole lung and different lung regions in patients and in healthy subjects. The lung count rate for a given region correlated well with the ventilation of that region. Clinical examples are given and discussed.

Unilateral empyema impacts the assessment of regional lung ventilation by electrical impedance tomography

International Nuclear Information System (INIS)

Bläser, D; Becher, T; Schädler, D; Elke, G; Weiler, N; Frerichs, I; Pulletz, S

2014-01-01

Several studies have shown the ability of electrical impedance tomography (EIT) to assess regional ventilation distribution in human lungs. Fluid accumulation in the pleural space as in empyema, typically occurring on one chest side, may influence the distribution of ventilation and the corresponding EIT findings. The aim of our study was to examine this effect on the assessment of regional ventilation by EIT. Six patients suffering from unilateral empyema and intubated with a double-lumen endotracheal tube were studied. EIT data were acquired during volume-controlled ventilation with bilateral (tidal volume (V T ): 800 ml) and unilateral ventilation (V T : 400 ml) of the right and left lungs. Mean tidal amplitudes of the EIT signal were calculated in all image pixels. The sums of these values, expressed as relative impedance change (rel. ΔZ), were then determined in whole images and functionally defined regions-of-interest (ROI). The sums of rel. ΔZ calculated during the two cases of one-lung ventilation either on the affected or unaffected side were significantly smaller than during bilateral ventilation. However, in contrast to previous findings in patients with no pleural pathology, very low values of rel. ΔZ were found when the lung on the affected side was ventilated. ROI-based analysis rendered higher values than the whole-image analysis in this case, nonetheless, the values were significantly smaller than when the unaffected side was ventilated in spite of identical V T . In conclusion, our results indicate that the presence of empyema may affect the quantitative evaluation of regional lung ventilation by EIT. (paper)

Transfer factor, lung volumes, resistance and ventilation distribution in healthy adults.

Science.gov (United States)

Verbanck, Sylvia; Van Muylem, Alain; Schuermans, Daniel; Bautmans, Ivan; Thompson, Bruce; Vincken, Walter

2016-01-01

Monitoring of chronic lung disease requires reference values of lung function indices, including putative markers of small airway function, spanning a wide age range.We measured spirometry, transfer factor of the lung for carbon monoxide (TLCO), static lung volume, resistance and ventilation distribution in a healthy population, studying at least 20 subjects per sex and per decade between the ages of 20 and 80 years.With respect to the Global Lung Function Initiative reference data, our subjects had average z-scores for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC of -0.12, 0.04 and -0.32, respectively. Reference equations were obtained which could account for a potential dependence of index variability on age and height. This was done for (but not limited to) indices that are pertinent to asthma and chronic obstructive pulmonary disease studies: forced expired volume in 6 s, forced expiratory flow, TLCO, specific airway conductance, residual volume (RV)/total lung capacity (TLC), and ventilation heterogeneity in acinar and conductive lung zones.Deterioration in acinar ventilation heterogeneity and lung clearance index with age were more marked beyond 60 years, and conductive ventilation heterogeneity showed the greatest increase in variability with age. The most clinically relevant deviation from published reference values concerned RV/TLC values, which were considerably smaller than American Thoracic Society/European Respiratory Society-endorsed reference values. Copyright ©ERS 2016.

A multiscale MDCT image-based breathing lung model with time-varying regional ventilation

Science.gov (United States)

Yin, Youbing; Choi, Jiwoong; Hoffman, Eric A.; Tawhai, Merryn H.; Lin, Ching-Long

2012-01-01

A novel algorithm is presented that links local structural variables (regional ventilation and deforming central airways) to global function (total lung volume) in the lung over three imaged lung volumes, to derive a breathing lung model for computational fluid dynamics simulation. The algorithm constitutes the core of an integrative, image-based computational framework for subject-specific simulation of the breathing lung. For the first time, the algorithm is applied to three multi-detector row computed tomography (MDCT) volumetric lung images of the same individual. A key technique in linking global and local variables over multiple images is an in-house mass-preserving image registration method. Throughout breathing cycles, cubic interpolation is employed to ensure C1 continuity in constructing time-varying regional ventilation at the whole lung level, flow rate fractions exiting the terminal airways, and airway deformation. The imaged exit airway flow rate fractions are derived from regional ventilation with the aid of a three-dimensional (3D) and one-dimensional (1D) coupled airway tree that connects the airways to the alveolar tissue. An in-house parallel large-eddy simulation (LES) technique is adopted to capture turbulent-transitional-laminar flows in both normal and deep breathing conditions. The results obtained by the proposed algorithm when using three lung volume images are compared with those using only one or two volume images. The three-volume-based lung model produces physiologically-consistent time-varying pressure and ventilation distribution. The one-volume-based lung model under-predicts pressure drop and yields un-physiological lobar ventilation. The two-volume-based model can account for airway deformation and non-uniform regional ventilation to some extent, but does not capture the non-linear features of the lung. PMID:23794749

A multiscale MDCT image-based breathing lung model with time-varying regional ventilation

Energy Technology Data Exchange (ETDEWEB)

Yin, Youbing, E-mail: youbing-yin@uiowa.edu [Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242 (United States); IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Department of Radiology, The University of Iowa, Iowa City, IA 52242 (United States); Choi, Jiwoong, E-mail: jiwoong-choi@uiowa.edu [Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242 (United States); IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Hoffman, Eric A., E-mail: eric-hoffman@uiowa.edu [Department of Radiology, The University of Iowa, Iowa City, IA 52242 (United States); Department of Biomedical Engineering, The University of Iowa, Iowa City, IA 52242 (United States); Department of Internal Medicine, The University of Iowa, Iowa City, IA 52242 (United States); Tawhai, Merryn H., E-mail: m.tawhai@auckland.ac.nz [Auckland Bioengineering Institute, The University of Auckland, Auckland (New Zealand); Lin, Ching-Long, E-mail: ching-long-lin@uiowa.edu [Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242 (United States); IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242 (United States)

2013-07-01

A novel algorithm is presented that links local structural variables (regional ventilation and deforming central airways) to global function (total lung volume) in the lung over three imaged lung volumes, to derive a breathing lung model for computational fluid dynamics simulation. The algorithm constitutes the core of an integrative, image-based computational framework for subject-specific simulation of the breathing lung. For the first time, the algorithm is applied to three multi-detector row computed tomography (MDCT) volumetric lung images of the same individual. A key technique in linking global and local variables over multiple images is an in-house mass-preserving image registration method. Throughout breathing cycles, cubic interpolation is employed to ensure C{sub 1} continuity in constructing time-varying regional ventilation at the whole lung level, flow rate fractions exiting the terminal airways, and airway deformation. The imaged exit airway flow rate fractions are derived from regional ventilation with the aid of a three-dimensional (3D) and one-dimensional (1D) coupled airway tree that connects the airways to the alveolar tissue. An in-house parallel large-eddy simulation (LES) technique is adopted to capture turbulent-transitional-laminar flows in both normal and deep breathing conditions. The results obtained by the proposed algorithm when using three lung volume images are compared with those using only one or two volume images. The three-volume-based lung model produces physiologically-consistent time-varying pressure and ventilation distribution. The one-volume-based lung model under-predicts pressure drop and yields un-physiological lobar ventilation. The two-volume-based model can account for airway deformation and non-uniform regional ventilation to some extent, but does not capture the non-linear features of the lung.

Metabolic acidosis may be as protective as hypercapnic acidosis in an ex-vivo model of severe ventilator-induced lung injury: a pilot study

Directory of Open Access Journals (Sweden)

Patsouris Efstratios

2011-04-01

Full Text Available Abstract Background There is mounting experimental evidence that hypercapnic acidosis protects against lung injury. However, it is unclear if acidosis per se rather than hypercapnia is responsible for this beneficial effect. Therefore, we sought to evaluate the effects of hypercapnic (respiratory versus normocapnic (metabolic acidosis in an ex vivo model of ventilator-induced lung injury (VILI. Methods Sixty New Zealand white rabbit ventilated and perfused heart-lung preparations were used. Six study groups were evaluated. Respiratory acidosis (RA, metabolic acidosis (MA and normocapnic-normoxic (Control - C groups were randomized into high and low peak inspiratory pressures, respectively. Each preparation was ventilated for 1 hour according to a standardized ventilation protocol. Lung injury was evaluated by means of pulmonary edema formation (weight gain, changes in ultrafiltration coefficient, mean pulmonary artery pressure changes as well as histological alterations. Results HPC group gained significantly greater weight than HPMA, HPRA and all three LP groups (P = 0.024, while no difference was observed between HPMA and HPRA groups regarding weight gain. Neither group differ on ultrafiltration coefficient. HPMA group experienced greater increase in the mean pulmonary artery pressure at 20 min (P = 0.0276 and 40 min (P = 0.0012 compared with all other groups. Histology scores were significantly greater in HP vs. LP groups (p Conclusions In our experimental VILI model both metabolic acidosis and hypercapnic acidosis attenuated VILI-induced pulmonary edema implying a mechanism other than possible synergistic effects of acidosis with CO2 for VILI attenuation.

Mechanical ventilation drives pneumococcal pneumonia into lung injury and sepsis in mice: protection by adrenomedullin.

Science.gov (United States)

Müller-Redetzky, Holger C; Will, Daniel; Hellwig, Katharina; Kummer, Wolfgang; Tschernig, Thomas; Pfeil, Uwe; Paddenberg, Renate; Menger, Michael D; Kershaw, Olivia; Gruber, Achim D; Weissmann, Norbert; Hippenstiel, Stefan; Suttorp, Norbert; Witzenrath, Martin

2014-04-14

Ventilator-induced lung injury (VILI) contributes to morbidity and mortality in acute respiratory distress syndrome (ARDS). Particularly pre-injured lungs are susceptible to VILI despite protective ventilation. In a previous study, the endogenous peptide adrenomedullin (AM) protected murine lungs from VILI. We hypothesized that mechanical ventilation (MV) contributes to lung injury and sepsis in pneumonia, and that AM may reduce lung injury and multiple organ failure in ventilated mice with pneumococcal pneumonia. We analyzed in mice the impact of MV in established pneumonia on lung injury, inflammation, bacterial burden, hemodynamics and extrapulmonary organ injury, and assessed the therapeutic potential of AM by starting treatment at intubation. In pneumococcal pneumonia, MV increased lung permeability, and worsened lung mechanics and oxygenation failure. MV dramatically increased lung and blood cytokines but not lung leukocyte counts in pneumonia. MV induced systemic leukocytopenia and liver, gut and kidney injury in mice with pneumonia. Lung and blood bacterial burden was not affected by MV pneumonia and MV increased lung AM expression, whereas receptor activity modifying protein (RAMP) 1-3 expression was increased in pneumonia and reduced by MV. Infusion of AM protected against MV-induced lung injury (66% reduction of pulmonary permeability p protect against development of lung injury, sepsis and extrapulmonary organ injury in mechanically ventilated individuals with severe pneumonia.

Correlation between alveolar ventilation and electrical properties of lung parenchyma

OpenAIRE

Roth, J. C., Ehrl, A., Becher, T., Frerichs, I., Schittny, J., Weller, N., Wall W. A.

2016-01-01

One key problem in modern medical imaging is linking measured data and actual physiological quantities. In this article we derive such a link between the electrical bioimpedance of lung parenchyma, which can be measured by electrical impedance tomography (EIT), and the magnitude of regional ventilation, a key towards understanding lung mechanics and developing novel protective ventilation strategies. Two rat-derived three-dimensional alveolar microstructures obtained from synchrotron-ba...

Pulmonary ventilation in children digital subtraction study

International Nuclear Information System (INIS)

Schmit, P.; Faure, C.; Sardet, A.; Bacques, O.

1985-01-01

Digital technique such as used in digital angiography can be used to study areas which lucency varies with time. A TID technique (time interval difference) has been used to study the lucency variation of the lung in children. This method has been used in 130 children with a mean age of 2 years and 8 months. In 85 children, the TID was normal: 5 false negative studies were found in this group. In the other 47 cases, the anomaly of the TID was due to a perfusion or a ventilation anomaly or both. No false positive are found. In 13 patients, comparison between the TID findings and the perfusion and ventilation nuclear scan was possible. In 9 patients, the correlation was excellent, the TID giving more some informations about the pulmonary mixic [fr

[Lung perfusion studies after percutaneous closure of patent ductus arteriosus using the Amplatzer Duct Occluder in children].

Science.gov (United States)

Parra-Bravo, José Rafael; Apolonio-Martínez, Adriana; Estrada-Loza, María de Jesús; Beirana-Palencia, Luisa Gracia; Ramírez-Portillo, César Iván

2015-01-01

The closure of patent ductus arteriosus with multiple devices has been associated with a reduction in lung perfusion. We evaluated the pulmonary perfusion after percutaneous closure of patent ductus arteriosus with the Amplatzer Duct Occluder device using perfusion lung scan. Thirty patients underwent successful percutaneous patent ductus arteriosus occlusions using the Amplatzer Duct Occluder device were included in this study. Lung perfusion scans were preformed 6 months after the procedure. Peak flow velocities and protrusion of the device were analyzed by Doppler echocardiography. A left lung perfusionductus arteriosus and the minimum and maximum diameter/length of the ductus arteriosus ratio were statistically significant in patients with abnormalities of lung perfusion. It was observed protrusion the device in 6 patients with a higher maximum flow rate in the left pulmonary artery. The left lung perfusion may be compromised after percutaneous closure of patent ductus arteriosus with the Amplatzer Duct Occluder. The increased flow velocity in the origin of the left pulmonary artery can be a poor indicator of reduction in pulmonary perfusion and can occur in the absence of protrusion of the device. Copyright © 2014 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Hypoxic pulmonary vasoconstriction in reptiles: a comparative study of four species with different lung structures and pulmonary blood pressures.

Science.gov (United States)

Skovgaard, Nini; Abe, Augusto S; Andrade, Denis V; Wang, Tobias

2005-11-01

Low O2 levels in the lungs of birds and mammals cause constriction of the pulmonary vasculature that elevates resistance to pulmonary blood flow and increases pulmonary blood pressure. This hypoxic pulmonary vasoconstriction (HPV) diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to more well-ventilated parts and is considered important for the local matching of ventilation to blood perfusion. In the present study, the effects of acute hypoxia on pulmonary and systemic blood flows and pressures were measured in four species of anesthetized reptiles with diverse lung structures and heart morphologies: varanid lizards (Varanus exanthematicus), caimans (Caiman latirostris), rattlesnakes (Crotalus durissus), and tegu lizards (Tupinambis merianae). As previously shown in turtles, hypoxia causes a reversible constriction of the pulmonary vasculature in varanids and caimans, decreasing pulmonary vascular conductance by 37 and 31%, respectively. These three species possess complex multicameral lungs, and it is likely that HPV would aid to secure ventilation-perfusion homogeneity. There was no HPV in rattlesnakes, which have structurally simple lungs where local ventilation-perfusion inhomogeneities are less likely to occur. However, tegu lizards, which also have simple unicameral lungs, did exhibit HPV, decreasing pulmonary vascular conductance by 32%, albeit at a lower threshold than varanids and caimans (6.2 kPa oxygen in inspired air vs. 8.2 and 13.9 kPa, respectively). Although these observations suggest that HPV is more pronounced in species with complex lungs and functionally divided hearts, it is also clear that other components are involved.

Effect of re-expansion after short-period lung collapse on pulmonary capillary permeability and pro-inflammatory cytokine gene expression in isolated rabbit lungs.

Science.gov (United States)

Funakoshi, T; Ishibe, Y; Okazaki, N; Miura, K; Liu, R; Nagai, S; Minami, Y

2004-04-01

Re-expansion pulmonary oedema is a rare complication caused by rapid re-expansion of a chronically collapsed lung. Several cases of pulmonary oedema associated with one-lung ventilation (OLV) have been reported recently. Elevated levels of pro-inflammatory cytokines in pulmonary oedema fluid are suggested to play important roles in its development. Activation of cytokines after re-expansion of collapsed lung during OLV has not been thoroughly investigated. Here we investigated the effects of re-expansion of the collapsed lung on pulmonary oedema formation and pro-inflammatory cytokine expression. Lungs isolated from female white Japanese rabbits were perfused and divided into a basal (BAS) group (n=7, baseline measurement alone), a control (CONT) group (n=9, ventilated without lung collapse for 120 min) and an atelectasis (ATEL) group (n=9, lung collapsed for 55 min followed by re-expansion and ventilation for 65 min). Pulmonary vascular resistance (PVR) and the coefficient of filtration (Kfc) were measured at baseline and 60 and 120 min. At the end of perfusion, bronchoalveolar lavage fluid/plasma protein ratio (B/P), wet/dry lung weight ratio (W/D) and mRNA expressions of tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta and myeloperoxidase (MPO) were determined. TNF-alpha and IL-1beta mRNA were significantly up-regulated in lungs of the ATEL group compared with BAS and CONT, though no significant differences were noted in PVR, Kfc, B/P and W/D within and between groups. MPO increased at 120 min in CONT and ATEL groups. Pro-inflammatory cytokines were up-regulated upon re-expansion and ventilation after short-period lung collapse, though no changes were noted in pulmonary capillary permeability.

High-resolution imaging of pulmonary ventilation and perfusion with {sup 68}Ga-VQ respiratory gated (4-D) PET/CT

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Callahan, Jason [Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Hofman, Michael S. [The University of Melbourne, Department of Medicine, Peter MacCallum Cancer Centre, Centre for Molecular Imaging, East Melbourne, VIC (Australia); Siva, Shankar [The University of Melbourne, Peter MacCallum Cancer Centre, Department of Radiation Oncology, East Melbourne, VIC (Australia); The University of Melbourne, Sir Peter MacCallum Department of Oncology, East Melbourne, VIC (Australia); Kron, Tomas [The University of Melbourne, Sir Peter MacCallum Department of Oncology, East Melbourne, VIC (Australia); The University of Melbourne, Peter MacCallum Cancer Centre, Department of Physical Sciences, East Melbourne, VIC (Australia); Schneider, Michal E. [Monash University, Department of Medical Imaging and Radiation Science, Clayton, VIC (Australia); Binns, David; Eu, Peter [Peter MacCallum Cancer Centre, Centre for Cancer Imaging, East Melbourne, VIC (Australia); Hicks, Rodney J. [The University of Melbourne, Sir Peter MacCallum Department of Oncology, Peter MacCallum Cancer Centre, Centre for Molecular Imaging, East Melbourne, VIC (Australia)

2014-02-15

Our group has previously reported on the use of {sup 68}Ga-ventilation/perfusion (VQ) PET/CT scanning for the diagnosis of pulmonary embolism. We describe here the acquisition methodology for {sup 68}Ga-VQ respiratory gated (4-D) PET/CT and the effects of respiratory motion on image coregistration in VQ scanning. A prospective study was performed in 15 patients with non-small-cell lung cancer. 4-D PET and 4-D CT images were acquired using an infrared marker on the patient's abdomen as a surrogate for breathing motion following inhalation of Galligas and intravenous administration of {sup 68}Ga-macroaggregated albumin. Images were reconstructed with phase-matched attenuation correction. The lungs were contoured on CT and PET VQ images during free-breathing (FB) and at maximum inspiration (Insp) and expiration (Exp). The similarity between PET and CT volumes was measured using the Dice coefficient (DC) comparing the following groups; (1) FB-PET/CT, (2) InspPET/InspCT, (3) ExpPET/Exp CT, and (4) FB-PET/AveCT. A repeated measures one-way ANOVA with multiple comparison Tukey tests were performed to evaluate any difference between the groups. Diaphragmatic motion in the superior-inferior direction on the 4-D CT scan was also measured. 4-D VQ scanning was successful in all patients without additional acquisition time compared to the nongated technique. The highest volume overlap was between ExpPET and ExpCT and between FB-PET and AveCT with a DC of 0.82 and 0.80 for ventilation and perfusion, respectively. This was significantly better than the DC comparing the other groups (0.78-0.79, p < 0.05). These values agreed with a visual inspection of the images with improved image coregistration around the lung bases. The diaphragmatic motion during the 4-D CT scan was highly variable with a range of 0.4-3.4 cm (SD 0.81 cm) in the right lung and 0-2.8 cm (SD 0.83 cm) in the left lung. Right-sided diaphragmatic nerve palsy was observed in 3 of 15 patients. {sup 68}Ga-VQ 4-D

Lung perfusion scintigraphy in congenital heart disease

International Nuclear Information System (INIS)

Sugimura, Hiroshi; Nagamachi, Shigeki; Hoshi, Hiroaki; Jinnouchi, Seishi; Oonishi, Takashi; Futami, Shigemi; Watanabe, Katsushi

1990-01-01

Lung perfusion scintigrams were reviewed retrospectively in 28 patients with congenital heart disease, whose ages ranged from the first year to 16 years with an average age of 5 years and 6 months. Seventy four MBq (2 mCi), 111 MBq (2 mCi), and 185 MBq (5 mCi) of Tc-99m macroaggregated albumin were iv injected in the age groups of 0-3, 4-11, and more than 11 years, respectively. Five minutes later, images were obtained in six projections. Abnormal findings on lung perfusion scintigrams were observed in 13 patients (46%). Of these patients, 8 (29%) had a partially decreased blood flow and 5 (17%) had a decreased blood flow in the unilateral lung. No significant difference in the occurrence of abnormal findings was observed among the age groups, although they tended to occur in younger patients. Sex, underlying conditions, and hemodynamics were also independent of scintigraphically abnormal findings. Even when classifying the patients as having either cyanotic or non-cyanotic heart disease, no significant difference in hemodynamics was observed between the group of abnormal findings and the group of normal findings. Pulmonary arteriography available in all patients failed to reveal abnormal findings, with the exception of pulmonary artery stenosis in 2 patients that corresponded to a decreased blood flow in the unilateral lung. Pulmonary artery stenosis seemed to be responsible for abnormal pulmonary blood flow, although other causes remained uncertain. (N.K.)

Comparison of /sup 133/Xe washout curves after bolus inhalation, perfusion, and equilibration

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Devos, P; Demedts, M; Vandecruys, A; Cosemans, J; De Roo, M

1978-01-01

In 6 healthy subjects and 13 patients with chronic obstructive lung disease, /sup 133/Xe washout curves after bolus inhalation, perfusion and equilibration were compared, using a gamma camera and computerized data handling. In healthy subjects the washout after equilibration was significantly slower than after the two other procedures. As this phenomenon occurred at the basal zones, it was attributed to the presence of airway closure in some units. In patients, the three washouts were significantly different from each other. This indicated the existence of intraregional inhomogeneity in ventilation, perfusion and ventilation-perfusion ratio. Our conclusion is that comparison of these different washout methods yields valuable information not only on absolute values of pulmonary function but also on the intraregional distribution, which cannot be obtained by other examinations.

One lung ventilation strategies for infants and children undergoing video assisted thoracoscopic surgery

Directory of Open Access Journals (Sweden)

Teddy Suratos Fabila

2013-01-01

Full Text Available The advantages of video assisted thoracoscopic surgery (VATS in children have led to its increased usage over the years. VATS, however, requires an efficient technique for one lung ventilation. Today, there is an increasing interest in developing the technique for lung isolation to meet the anatomic and physiologic variations in infants and children. This article aims to provide an updated and comprehensive review on one-lung ventilation strategies for infants and children undergoing VATS. Search of terms such as ′One lung ventilation for infants and children′, ′Video assisted thoracoscopic surgery for infants and children′, and ′Physiologic changes during one lung ventilation for infants and children′ were used. The search mechanics and engines for this review included the following: Kandang Kerbau Hospital (KKH eLibrary, PubMed, Ovid Medline, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews. During the search the author focused on significant current and pilot randomized control trials, case reports, review articles, and editorials. Critical decision making on what device to use based on the age, weight, and pathology of the patient; and how to use it for lung isolation are discussed in this article. Furthermore, additional information regarding the advantages, limitations, techniques of insertion and maintenance of each device for one lung ventilation in infants and children were the highlights in this article.

Critical evaluation of emergency stockpile ventilators in an in vitro model of pediatric lung injury.

Science.gov (United States)

Custer, Jason W; Watson, Christopher M; Dwyer, Joe; Kaczka, David W; Simon, Brett A; Easley, R Blaine

2011-11-01

Modern health care systems may be inadequately prepared for mass casualty respiratory failure requiring mechanical ventilation. Current health policy has focused on the "stockpiling" of emergency ventilators, though little is known about the performance of these ventilators under conditions of respiratory failure in adults and children. In this study, we seek to compare emergency ventilator performance characteristics using a test lung simulating pediatric lung injury. Evaluation of ventilator performance using a test lung. Laboratory. None. Six transport/emergency ventilators capable of adult/child application were chosen on the basis of manufacturer specifications, Autovent 3000, Eagle Univent 754, EPV 100, LP-10, LTV 1200, and Parapac 200D. Manufacturer specifications for each ventilator were reviewed and compared with known standards for alarms and functionality for surge capacity ventilators. The delivered tidal volume, gas flow characteristics, and airway pressure waveforms were evaluated in vitro using a mechanical test lung to model pediatric lung injury and integrated software. Test lung and flow meter recordings were analyzed over a range of ventilator settings. Of the six ventilators assessed, only two had the minimum recommended alarm capability. Four of the six ventilators tested were capable of being set to deliver a tidal volume of less than 200 mL. The delivered tidal volume for all ventilators was within 8% of the nominal setting at a positive end expiratory pressure of zero but was reduced significantly with the addition of positive end expiratory pressure (range, ±10% to 30%; p ventilators tested performed comparably at higher set tidal volumes; however, only three of the ventilators tested delivered a tidal volume across the range of ventilator settings that was comparable to that of a standard intensive care unit ventilator. Multiple ventilators are available for the provision of ventilation to children with respiratory failure in a mass

Continuous use of an adaptive lung ventilation controller in critically ...

African Journals Online (AJOL)

1995-05-05

May 5, 1995 ... Adaptive lung ventilation (ALV) refers to closed-loop mechanical ventilation designed to work ... optimise the controller performance, the volume controller .... PawEE), vital capacity IYC), an index of airway resistance relative to ...

Perfusion study in the pulmonary hilar region by SPECT

International Nuclear Information System (INIS)

Satoh, Katashi; Tanabe, Masatada; Kawase, Yoshiro

1990-01-01

Alveoli in the hilar region comprise the peripheral area containing daughter branches from subsegmental or one more divisional peripheral bronchi. Pulmonary perfusion in hilar region was examined by SPECT (single photon emission CT) in ten normal volunteers. ROI (region of interest) in the axial images were set in the hilar region, the upper, middle and lower lung fields with 10.8 mm thickness. Counts/one pixel (C/P) were calculated in these ROI. There was a tendency of C/P increase from upper to lower lung field. And there were no significant differences in C/P increase between hilar region and other axial fields. In the chronic obstructive pulmonary diseases, however, ventilation studies in the previous reports using Xe dynamic CT or PET (positron emission tomography) showed differences between outer region and hilar region. This method will be expected to evaluate the pulmonary perfusion not only in the whole lung but in different lung areas, including the hilar region in the chronic obstructive pulmonary diseases. (author)

Spontaneous breathing during lung-protective ventilation in an experimental acute lung injury model: high transpulmonary pressure associated with strong spontaneous breathing effort may worsen lung injury.

Science.gov (United States)

Yoshida, Takeshi; Uchiyama, Akinori; Matsuura, Nariaki; Mashimo, Takashi; Fujino, Yuji

2012-05-01

We investigated whether potentially injurious transpulmonary pressure could be generated by strong spontaneous breathing and exacerbate lung injury even when plateau pressure is limited to ventilation, each combined with weak or strong spontaneous breathing effort. Inspiratory pressure for low tidal volume ventilation was set at 10 cm H2O and tidal volume at 6 mL/kg. For moderate tidal volume ventilation, the values were 20 cm H2O and 7-9 mL/kg. The groups were: low tidal volume ventilation+spontaneous breathingweak, low tidal volume ventilation+spontaneous breathingstrong, moderate tidal volume ventilation+spontaneous breathingweak, and moderate tidal volume ventilation+spontaneous breathingstrong. Each group had the same settings for positive end-expiratory pressure of 8 cm H2O. Respiratory variables were measured every 60 mins. Distribution of lung aeration and alveolar collapse were histologically evaluated. Low tidal volume ventilation+spontaneous breathingstrong showed the most favorable oxygenation and compliance of respiratory system, and the best lung aeration. By contrast, in moderate tidal volume ventilation+spontaneous breathingstrong, the greatest atelectasis with numerous neutrophils was observed. While we applied settings to maintain plateau pressure at ventilation+spontaneous breathingstrong, transpulmonary pressure rose >33 cm H2O. Both minute ventilation and respiratory rate were higher in the strong spontaneous breathing groups. Even when plateau pressure is limited to mechanical ventilation, transpulmonary pressure and tidal volume should be strictly controlled to prevent further lung injury.

APRV Mode in Ventilator Induced Lung Injury (VILI

Directory of Open Access Journals (Sweden)

Ata Mahmoodpoor

2014-01-01

Full Text Available Ventilator-Induced Lung Injury (VILI, being a significant iatrogenic complication in the ICU patients, is associated with high morbidity and mortality. Numerous approaches, protocols and ventilation modes have been introduced and examined to decrease the incidence of VILI in the ICU patients. Airway pressure release ventilation (APRV, firstly introduced by Stock and Downs in 1987, applies higher Continuous Positive Airway Pressure (CPAP levels in prolonged periods (P and T high in order to preserve satisfactory lung volume and consequently alveolar recruitment. This mode benefits a time-cycled release phase to a lower set of pressure for a short period of time (P and T low i.e. release time (1,2. While some advantages have been introduced for APRV such as efficiently recruited alveoli over time, more homogeneous ventilation, less volutrauma, probable stabilization of patent alveoli and reduction in atelectrauma, protective effects of APRV on lung damage only seem to be substantial if spontaneous breathing responds to more than 30% of total minute ventilation (3. APRV in ARDS patients should be administered cautiously; T low<0.6 seconds, for recruiting collapsed alveoli; however overstretching of alveoli especially during P high should not be neglected and appropriate sedation considered. The proposed advantages for APRV give the impression of being outstanding; however, APRV, as a non-physiologic inverse ratio mode of ventilation, might result in inflammation mainly due to impaired patient-ventilator interaction explaining the negative or minimally desirable effects of APRV on inflammation (4. Consequently, continuous infusion of neuromuscular blocking drugs during ARDS has been reported to reduce mortality (5. There are insufficient confirming data on the superiority of APRV above other ventilatory methods in regard to oxygenation, hemodynamics, regional blood flow, patient comfort and length of mechanical ventilation. Based on current findings

Variability in usual care mechanical ventilation for pediatric acute lung injury: the potential benefit of a lung protective computer protocol.

Science.gov (United States)

Khemani, Robinder G; Sward, Katherine; Morris, Alan; Dean, J Michael; Newth, Christopher J L

2011-11-01

Although pediatric intensivists claim to embrace lung protective ventilation for acute lung injury (ALI), ventilator management is variable. We describe ventilator changes clinicians made for children with hypoxemic respiratory failure, and evaluate the potential acceptability of a pediatric ventilation protocol. This was a retrospective cohort study performed in a tertiary care pediatric intensive care unit (PICU). The study period was from January 2000 to July 2007. We included mechanically ventilated children with PaO(2)/FiO(2) (P/F) ratio less than 300. We assessed variability in ventilator management by evaluating actual changes to ventilator settings after an arterial blood gas (ABG). We evaluated the potential acceptability of a pediatric mechanical ventilation protocol we adapted from National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI) Acute Respiratory Distress Syndrome (ARDS) Network protocols by comparing actual practice changes in ventilator settings to changes that would have been recommended by the protocol. A total of 2,719 ABGs from 402 patients were associated with 6,017 ventilator settings. Clinicians infrequently decreased FiO(2), even when the PaO(2) was high (>68 mmHg). The protocol would have recommended more positive end expiratory pressure (PEEP) than was used in actual practice 42% of the time in the mid PaO(2) range (55-68 mmHg) and 67% of the time in the low PaO(2) range (ventilator rate (VR) when the protocol would have recommended a change, even when the pH was greater than 7.45 with PIP at least 35 cmH(2)O. There may be lost opportunities to minimize potentially injurious ventilator settings for children with ALI. A reproducible pediatric mechanical ventilation protocol could prompt clinicians to make ventilator changes that are consistent with lung protective ventilation.

Heliox allows for lower minute volume ventilation in an animal model of ventilator-induced lung injury.

Directory of Open Access Journals (Sweden)

Charlotte J Beurskens

Full Text Available BACKGROUND: Helium is a noble gas with a low density, allowing for lower driving pressures and increased carbon dioxide (CO2 diffusion. Since application of protective ventilation can be limited by the development of hypoxemia or acidosis, we hypothesized that therefore heliox facilitates ventilation in an animal model of ventilator-induced lung injury. METHODS: Sprague-Dawley rats (N=8 per group were mechanically ventilated with heliox (50% oxygen; 50% helium. Controls received a standard gas mixture (50% oxygen; 50% air. VILI was induced by application of tidal volumes of 15 mL kg(-1; lung protective ventilated animals were ventilated with 6 mL kg(-1. Respiratory parameters were monitored with a pneumotach system. Respiratory rate was adjusted to maintain arterial pCO2 within 4.5-5.5 kPa, according to hourly drawn arterial blood gases. After 4 hours, bronchoalveolar lavage fluid (BALF was obtained. Data are mean (SD. RESULTS: VILI resulted in an increase in BALF protein compared to low tidal ventilation (629 (324 vs. 290 (181 μg mL(-1; p<0.05 and IL-6 levels (640 (8.7 vs. 206 (8.7 pg mL(-1; p<0.05, whereas cell counts did not differ between groups after this short course of mechanical ventilation. Ventilation with heliox resulted in a decrease in mean respiratory minute volume ventilation compared to control (123 ± 0.6 vs. 146 ± 8.9 mL min(-1, P<0.001, due to a decrease in respiratory rate (22 (0.4 vs. 25 (2.1 breaths per minute; p<0.05, while pCO2 levels and tidal volumes remained unchanged, according to protocol. There was no effect of heliox on inspiratory pressure, while compliance was reduced. In this mild lung injury model, heliox did not exert anti-inflammatory effects. CONCLUSIONS: Heliox allowed for a reduction in respiratory rate and respiratory minute volume during VILI, while maintaining normal acid-base balance. Use of heliox may be a useful approach when protective tidal volume ventilation is limited by the development of

Radiation-Induced Reductions in Regional Lung Perfusion: 0.1-12 Year Data From a Prospective Clinical Study

International Nuclear Information System (INIS)

Zhang Junan; Ma Jinli; Zhou Sumin; Hubbs, Jessica L.; Wong, Terence Z.; Folz, Rodney J.; Evans, Elizabeth S.; Jaszczak, Ronald J.; Clough, Robert; Marks, Lawrence B.

2010-01-01

Purpose: To assess the time and regional dependence of radiation therapy (RT)-induced reductions in regional lung perfusion 0.1-12 years post-RT, as measured by single photon emission computed tomography (SPECT) lung perfusion. Materials/Methods: Between 1991 and 2005, 123 evaluable patients receiving RT for tumors in/around the thorax underwent SPECT lung perfusion scans before and serially post-RT (0.1-12 years). Registration of pre- and post-RT SPECT images with the treatment planning computed tomography, and hence the three-dimensional RT dose distribution, allowed changes in regional SPECT-defined perfusion to be related to regional RT dose. Post-RT follow-up scans were evaluated at multiple time points to determine the time course of RT-induced regional perfusion changes. Population dose response curves (DRC) for all patients at different time points, different regions, and subvolumes (e.g., whole lungs, cranial/caudal, ipsilateral/contralateral) were generated by combining data from multiple patients at similar follow-up times. Each DRC was fit to a linear model, and differences statistically analyzed. Results: In the overall groups, dose-dependent reductions in perfusion were seen at each time post-RT. The slope of the DRC increased over time up to 18 months post-RT, and plateaued thereafter. Regional differences in DRCs were only observed between the ipsilateral and contralateral lungs, and appeared due to tumor-associated changes in regional perfusion. Conclusions: Thoracic RT causes dose-dependent reductions in regional lung perfusion that progress up to ∼18 months post-RT and persists thereafter. Tumor shrinkage appears to confound the observed dose-response relations. There appears to be similar dose response for healthy parts of the lungs at different locations.

Regional study of ventilation with inhaled xenon 133 in children

International Nuclear Information System (INIS)

Gaultier, C.; Mensch, B.; Gerbeaux, J.

1975-01-01

A regional exploration of pulmonary ventilation in a population of 104 infants and children by a study of distribution and washout of xenon 133 inhaled with rebreathing is carried out. The results are expressed by photographs (gamma-camera) and time-activity curves. The indications for regional exploration were oriented by the existence on the straight X-ray film of a localised ventilation disorder (a hyperlucent area or an opacity). This study permitted physiopathological analysis and guided endobronchial examinations. The functional results obtained, complete and explain other methods of exploration of lung function by spirography, ventilatory mechanics, transthoracic electrical measurements and study of lung perfusion with technetium 99m [fr

[Lung-brain interaction in the mechanically ventilated patient].

Science.gov (United States)

López-Aguilar, J; Fernández-Gonzalo, M S; Turon, M; Quílez, M E; Gómez-Simón, V; Jódar, M M; Blanch, L

2013-10-01

Patients with acute lung injury or acute respiratory distress syndrome (ARDS) admitted to the ICU present neuropsychological alterations, which in most cases extend beyond the acute phase and have an important adverse effect upon quality of life. The aim of this review is to deepen in the analysis of the complex interaction between lung and brain in critically ill patients subjected to mechanical ventilation. This update first describes the neuropsychological alterations occurring both during the acute phase of ICU stay and at discharge, followed by an analysis of lung-brain interactions during mechanical ventilation, and finally explores the etiology and mechanisms leading to the neurological disorders observed in these patients. The management of critical patients requires an integral approach focused on minimizing the deleterious effects over the short, middle or long term. Copyright © 2012 Elsevier España, S.L. y SEMICYUC. All rights reserved.

Framework for radiation pneumonitis risk stratification based on anatomic and perfused lung dosimetry

Energy Technology Data Exchange (ETDEWEB)

Dhami, Gurleen; Zeng, Jing; Patel, Shilpen A.; Rengan, Ramesh [University of Washington School of Medicine, Department of Radiation Oncology, Seattle, WA (United States); Vesselle, Hubert J.; Kinahan, Paul E.; Miyaoka, Robert S. [University of Washington School of Medicine, Department of Radiology, Seattle, WA (United States); Bowen, Stephen R. [University of Washington School of Medicine, Department of Radiation Oncology, Seattle, WA (United States); University of Washington School of Medicine, Department of Radiology, Seattle, WA (United States)

2017-05-15

To design and apply a framework for predicting symptomatic radiation pneumonitis in patients undergoing thoracic radiation, using both pretreatment anatomic and perfused lung dose-volume parameters. Radiation treatment planning CT scans were coregistered with pretreatment [{sup 99m}Tc]MAA perfusion SPECT/CT scans of 20 patients who underwent definitive thoracic radiation. Clinical radiation pneumonitis was defined as grade ≥ 2 (CTCAE v4 grading system). Anatomic lung dose-volume parameters were collected from the treatment planning scans. Perfusion dose-volume parameters were calculated from pretreatment SPECT/CT scans. Equivalent doses in 2 Gy per fraction were calculated in the lung to account for differences in treatment regimens and spatial variations in lung dose (EQD2{sub lung}). Anatomic lung dosimetric parameters (MLD) and functional lung dosimetric parameters (pMLD{sub 70%}) were identified as candidate predictors of grade ≥ 2 radiation pneumonitis (AUC > 0.93, p < 0.01). Pairing of an anatomic and functional dosimetric parameter (e.g., MLD and pMLD{sub 70%}) may further improve prediction accuracy. Not all individuals with high anatomic lung dose (MLD > 13.6 GyEQD2{sub lung}, 19.3 Gy for patients receiving 60 Gy in 30 fractions) developed radiation pneumonitis, but all individuals who also had high mean dose to perfused lung (pMLD{sub 70%} > 13.3 GyEQD2) developed radiation pneumonitis. The preliminary application of this framework revealed differences between anatomic and perfused lung dosimetry in this limited patient cohort. The addition of perfused lung parameters may help risk stratify patients for radiation pneumonitis, especially in treatment plans with high anatomic mean lung dose. Further investigations are warranted. (orig.) [German] Erstellung und Anwendung eines Rahmenwerks zur Vorhersage symptomatischer Strahlenpneumonitis bei Patienten mit einer Thorax-Bestrahlung anhand anatomischer und perfundierter Lungendosis-Volumen-Parameter in der

Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation.

Science.gov (United States)

Beurskens, Charlotte J; Brevoord, Daniel; Lagrand, Wim K; van den Bergh, Walter M; Vroom, Margreeth B; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P

2014-01-01

Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arrest and mechanically ventilated for 3 hours with heliox (50% helium; 50% oxygen). A fixed protective ventilation protocol (6 mL/kg) was used, with prospective observation for changes in lung mechanics and gas exchange. Statistics was by Bonferroni post-hoc correction with statistical significance set at P ventilation, respiratory rate decreased (25 ± 4 versus 23 ± 5 breaths min(-1), P = 0.010). Minute volume ventilation showed a trend to decrease compared to baseline (11.1 ± 1.9 versus 9.9 ± 2.1 L min(-1), P = 0.026), while reducing PaCO2 levels (5.0 ± 0.6 versus 4.5 ± 0.6 kPa, P = 0.011) and peak pressures (21.1 ± 3.3 versus 19.8 ± 3.2 cm H2O, P = 0.024). Conclusions. Heliox improved CO2 elimination while allowing reduced minute volume ventilation in adult patients during protective mechanical ventilation.

Unusual ventilation perfusion scintigram in a case of immunologic pulmonary edema clinically simulating pulmonary embolism

International Nuclear Information System (INIS)

Campeau, R.J.; Faust, J.M.; Ahmad, S.

1987-01-01

A case of immunologic pulmonary edema secondary to hydrochlorothiazide allergy developed in a 55-year-old woman that clinically simulated pulmonary embolism. The patient had abnormal washin images with normal washout images on an Xe-133 ventilation study. On the perfusion study, large bilateral central and posterior perfusion defects were present that showed an unusual mirror image pattern on the lateral and posterior oblique views. Resolution of radiographic and scintigraphic abnormalities occurred over a 3-day period in conjunction with corticosteroid therapy

Re-expansion pulmonary oedema - differential lung ventilation comes to the rescue

Directory of Open Access Journals (Sweden)

Shreepathi K Achar

2014-01-01

Full Text Available Re-expansion pulmonary oedema (REPE is a rare complication following re-inflation of a chronically collapsed lung, which is often fatal. We present a case of a 22-year-old male who presented to the hospital with severe respiratory distress and a history of blunt abdominal trauma 3 months back. He was diagnosed to have left sided diaphragmatic hernia with a mediastinal shift to the right, and was posted for emergency repair of the same. After surgical decompression of the left hemi-thorax and reduction of the abdominal contents, re-expansion of the left lung was achieved, following which patient developed REPE. A left sided double lumen tube was then inserted to prevent flooding and cross contamination of the right lung and ventilation of both lungs was maintained intraoperatively. Post-operatively, REPE was successfully managed by differential lung ventilation with a lung salvage strategy to the left lung and a lung protective strategy to the right lung.

Lung split function test and pneumonectomy. A lower limit for operability

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Tønnesen, K H; Dige-Petersen, H; Lund, J O

1978-01-01

Regional 133Xe ventilation/perfusion studies were used to predict residual lung function after pulmonary resections. The accuracy of the method was good as checked by postoperative spirometry in 11 patients. In 25 patients with impaired lung function and pulmonary cancer, who were consecutively...

Injurious mechanical ventilation in the normal lung causes a progressive pathologic change in dynamic alveolar mechanics

OpenAIRE

Pavone, Lucio A; Albert, Scott; Carney, David; Gatto, Louis A; Halter, Jeffrey M; Nieman, Gary F

2007-01-01

Introduction Acute respiratory distress syndrome causes a heterogeneous lung injury, and without protective mechanical ventilation a secondary ventilator-induced lung injury can occur. To ventilate noncompliant lung regions, high inflation pressures are required to 'pop open' the injured alveoli. The temporal impact, however, of these elevated pressures on normal alveolar mechanics (that is, the dynamic change in alveolar size and shape during ventilation) is unknown. In the present study we ...

First Danish experience with ex vivo lung perfusion of donor lungs before transplantation

DEFF Research Database (Denmark)

Henriksen, Ian Sune Iversen; Møller-Sørensen, Hasse; Møller, Christian Holdfold

2014-01-01

INTRODUCTION: The number of lung transplantations is limited by a general lack of donor organs. Ex vivo lung perfusion (EVLP) is a novel method to optimise and evaluate marginal donor lungs prior to transplantation. We describe our experiences with EVLP in Denmark during the first year after its...... introduction. MATERIAL AND METHODS: The study was conducted by prospective registration of donor offers and lung transplantations in Denmark from 1 May 2012 to 30 April 2013. Donor lungs without any contraindications were transplanted in the traditional manner. Taken for EVLP were donor lungs that were...... otherwise considered transplantable, but failed to meet the usual criteria due to possible contusions or because they were from donors with sepsis or unable to pass the oxygenation test. RESULTS: In the study period, seven of 33 Danish lung transplantations were made possible due to EVLP. One patient died...

Relative Tissue Factor Deficiency Attenuates Ventilator-Induced Coagulopathy but Does Not Protect against Ventilator-Induced Lung Injury in Mice

Directory of Open Access Journals (Sweden)

Esther K. Wolthuis

2012-01-01

Full Text Available Preventing tissue-factor-(TF- mediated systemic coagulopathy improves outcome in models of sepsis. Preventing TF-mediated pulmonary coagulopathy could attenuate ventilator-induced lung injury (VILI. We investigated the effect of relative TF deficiency on pulmonary coagulopathy and inflammation in a murine model of VILI. Heterozygous TF knockout (TF+/− mice and their wild-type (TF+/+ littermates were sedated (controls or sedated, tracheotomized, and mechanically ventilated with either low or high tidal volumes for 5 hours. Mechanical ventilation resulted in pulmonary coagulopathy and inflammation, with more injury after mechanical ventilation with higher tidal volumes. Compared with TF+/+ mice, TF+/− mice demonstrated significantly lower pulmonary thrombin-antithrombin complex levels in both ventilation groups. There were, however, no differences in lung wet-to-dry ratio, BALF total protein levels, neutrophil influx, and lung histopathology scores between TF+/− and TF+/+ mice. Notably, pulmonary levels of cytokines were significantly higher in TF+/− as compared to TF+/+ mice. Systemic levels of cytokines were not altered by the relative absence of TF. TF deficiency is associated with decreased pulmonary coagulation independent of the ventilation strategy. However, relative TF deficiency does not reduce VILI and actually results in higher pulmonary levels of inflammatory mediators.