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Sample records for isolated perfused segments

  1. Isolated limb perfusion.

    Science.gov (United States)

    Gillespie, Rosalyn; Chantier, Nariane

    1994-12-08

    Growing concern over the rising incidence of malignant melanoma has brought about a need for information on this disorder and the treatment available. Isolated limb perfusion is a relatively new technique used in only a few hospitals. An increased knowledge base will lead to a better understanding of the nursing care required and to a more in-depth care plan.

  2. Secretion of neurotensin from isolated perfused porcine ileum

    DEFF Research Database (Denmark)

    Holst Pedersen, J; Knuthsen, S; Bernabei, M

    1988-01-01

    The secretion and molecular nature of immunoreactive neurotensin (NT) was studied following stimulation of an isolated perfused porcine ileal segment with glucose, triglyceride and intra-arterial infusion of gastrin-releasing peptide (GRP). Secreted peptides were separated using gel chromatography...... in doses from 10(-10) to 10(-8) M stimulated NT release in a dose-related manner. Following gel chromatography only the intact peptide and no smaller or larger molecular size immunoreactive components were observed. The study showed that both luminal and humoral stimuli release NT from the isolated pig...

  3. Reactivity of the isolated perfused rat tail vascular bed

    Directory of Open Access Journals (Sweden)

    A.S. França

    1997-07-01

    Full Text Available Isolated segments of the perfused rat tail artery display a high basal tone when compared to other isolated arteries such as the mesenteric and are suitable for the assay of vasopressor agents. However, the perfusion of this artery in the entire tail has not yet been used for functional studies. The main purpose of the present study was to identify some aspects of the vascular reactivity of the rat tail vascular bed and validate this method to measure vascular reactivity. The tail severed from the body was perfused with Krebs solution containing different Ca2+ concentrations at different flow rates. Rats were anesthetized with sodium pentobarbital (65 mg/kg and heparinized (500 U. The tail artery was dissected near the tail insertion, cannulated and perfused with Krebs solution plus 30 µM EDTA at 36oC and 2.5 ml/min and the procedures were started after equilibration of the perfusion pressure. In the first group a dose-response curve to phenylephrine (PE (0.5, 1, 2 and 5 µg, bolus injection was obtained at different flow rates (1.5, 2.5 and 3.5 ml/min. The mean perfusion pressure increased with flow as well as PE vasopressor responses. In a second group the flow was changed (1.5, 2, 2.5, 3 and 3.5 ml/min at different Ca2+ concentrations (0.62, 1.25, 2.5 and 3.75 mM in the Krebs solution. Increasing Ca2+ concentrations did not alter the flow-pressure relationship. In the third group a similar protocol was performed but the rat tail vascular bed was perfused with Krebs solution containing PE (0.1 µg/ml. There was an enhancement of the effect of PE with increasing external Ca2+ and flow. PE vasopressor responses increased after endothelial damage with air and CHAPS, suggesting an endothelial modulation of the tone of the rat tail vascular bed. These experiments validate the perfusion of the rat tail vascular bed as a method to investigate vascular reactivity

  4. Phosphorus NMR of isolated perfused morris hepatomas

    International Nuclear Information System (INIS)

    Graham, R.A.; Meyer, R.A.; Brown, T.R.; Sauer, L.A.

    1986-01-01

    The authors are developing techniques for the study of perfused solid tumors by NMR. Tissue-isolated solid hepatomas were grown to 1-2 cm diameter as described previously. The arterial supply was isolated and the tumors perfused (0.5 - 1.0 ml/min) in vitro at 25 C with a 15% suspension of red blood cells in Krebs-Henseliet solution. 31 P-NMR spectra were acquired at 162 MHz in a specially-designed NMR probe using a solenoidal coil. Intracellular pH (monitored from the chemical shift of inorganic phosphate) and ATP levels were stable for up to 6 hrs during perfusion. During 30 min of global ischemia, ATP decreased by 75% and pH fell from 7.0 to 6.7. These changes were reversed by 1 hr reperfusion. In addition to ATP and phosphate, the spectra included a large resonance due to phosphomonoesters, as well as peaks consistent with glycerylphosphocholine, glyceryl-phosphoethanolamine, phosphocreatine, NAD, and UDPG. However, the most novel feature of the spectra was the presence of an unidentified peak in the phosphonate region (+ 16.9 ppm). The peak was not present in spectra of muscle, liver, brain, kidney, or fat tissues excised from the same animals. They are presently attempting to identify the compound that gives rise to this peak and to establish its metabolic origin

  5. Prognostic validation of a 17-segment score derived from a 20-segment score for myocardial perfusion SPECT interpretation.

    Science.gov (United States)

    Berman, Daniel S; Abidov, Aiden; Kang, Xingping; Hayes, Sean W; Friedman, John D; Sciammarella, Maria G; Cohen, Ishac; Gerlach, James; Waechter, Parker B; Germano, Guido; Hachamovitch, Rory

    2004-01-01

    Recently, a 17-segment model of the left ventricle has been recommended as an optimally weighted approach for interpreting myocardial perfusion single photon emission computed tomography (SPECT). Methods to convert databases from previous 20- to new 17-segment data and criteria for abnormality for the 17-segment scores are needed. Initially, for derivation of the conversion algorithm, 65 patients were studied (algorithm population) (pilot group, n = 28; validation group, n = 37). Three conversion algorithms were derived: algorithm 1, which used mid, distal, and apical scores; algorithm 2, which used distal and apical scores alone; and algorithm 3, which used maximal scores of the distal septal, lateral, and apical segments in the 20-segment model for 3 corresponding segments of the 17-segment model. The prognosis population comprised 16,020 consecutive patients (mean age, 65 +/- 12 years; 41% women) who had exercise or vasodilator stress technetium 99m sestamibi myocardial perfusion SPECT and were followed up for 2.1 +/- 0.8 years. In this population, 17-segment scores were derived from 20-segment scores by use of algorithm 2, which demonstrated the best agreement with expert 17-segment reading in the algorithm population. The prognostic value of the 20- and 17-segment scores was compared by converting the respective summed scores into percent myocardium abnormal. Conversion algorithm 2 was found to be highly concordant with expert visual analysis by the 17-segment model (r = 0.982; kappa = 0.866) in the algorithm population. In the prognosis population, 456 cardiac deaths occurred during follow-up. When the conversion algorithm was applied, extent and severity of perfusion defects were nearly identical by 20- and derived 17-segment scores. The receiver operating characteristic curve areas by 20- and 17-segment perfusion scores were identical for predicting cardiac death (both 0.77 +/- 0.02, P = not significant). The optimal prognostic cutoff value for either 20

  6. Characterizing potential heart agents with an isolated perfused heart system

    International Nuclear Information System (INIS)

    Pendleton, D.B.; Sands, H.; Gallagher, B.M.; Camin, L.L.

    1984-01-01

    The authors have used an isolated perfused heart system for characterizing potential myocardial perfusion radiopharamaceuticals. Rabbit or guinea pig (GP) hearts are removed and perfused through the aorta with a blood-free buffer. Heart rate and ventricular pressure are monitored as indices of viability. Tc-99m-MAA is 96-100% retained in these hearts, and Tc-99m human serum albumin shows less than 5% extraction. Tl-201 is 30-40% extracted. It is known that in-vivo, Tc-99m(dmpe)/sub 2/Cl/sub 2//sup +/ is taken up by rabbit heart but not by GP or human heart. Analogous results are obtained with the isolated perfused heart model, where the complex is extracted well by the isolated rabbit heart (24%) but not by the GP heart (<5%). Values are unchanged if human, rabbit or GP blood is mixed and co-injected with the complex. Tc-99m)dmpe)/sub 3//sup +/ is also taken up by rabbit but not by GP hearts in-vivo. However, isolated perfused hearts of both species extract this complex well (45-52%). Heart uptake is diminished to <7% if the complex is pre-equilibrated with human blood. GP blood produces a moderate inhibition (in GP hearts only) and rabbit blood has no effect. This suggests that a human or GP blood factor may have a significant effect on heart uptake of this complex. Tc-99m(CN-t-butyl)/sub 6//sup +/ is taken up well by both rabbit and GP hearts in-vivo, and is extracted 100% by both isolated perfused hearts. Heart retention remains high (73-75%) in the presence of human blood

  7. Assessment of the relationship between morphological emphysema phenotype and corresponding pulmonary perfusion pattern on a segmental level

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    Bryant, Mark; Kauczor, Hans-Ulrich [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Member of German Lung Research Center DZL, Translational Lung Research Center TLRC-H, Heidelberg (Germany); Ley, Sebastian [Chirurgische Klinik Dr. Rinecker, Department of Diagnostic and Interventional Radiology, Munich (Germany); Ludwig Maximilians University, Department of Clinical Radiology, Munich (Germany); Eberhardt, Ralf; Herth, Felix [Thoraxklinik University of Heidelberg, Department of Pneumology and Critical Care Medicine, Heidelberg (Germany); Member of German Lung Research Center DZL, Translational Lung Research Center TLRC-H, Heidelberg (Germany); Menezes, Ravi [University of Toronto, Medical Imaging, Toronto (Canada); Sedlaczek, Oliver [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); German Cancer Research Center, Department of Radiology, Heidelberg (Germany); Member of German Lung Research Center DZL, Translational Lung Research Center TLRC-H, Heidelberg (Germany); Ley-Zaporozhan, Julia [University of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Ludwig Maximilians University, Department of Clinical Radiology, Munich (Germany)

    2015-01-15

    Distinct morphological emphysema phenotypes were assessed by CT to show characteristic perfusion defect patterns. Forty-one patients with severe emphysema (GOLD III/IV) underwent three-dimensional high resolution computed tomography (3D-HRCT) and contrast-enhanced magnetic resonance (MR) perfusion. 3D-HRCT data was visually analyzed for emphysema phenotyping and quantification by consensus of three experts in chest-radiology. The predominant phenotype per segment was categorized as normal, centrilobular, panlobular or paraseptal. Segmental lung perfusion was visually analyzed using six patterns of pulmonary perfusion (1-normal; 2-mild homogeneous reduction in perfusion; 3-heterogeneous perfusion without focal defects; 4-heterogeneous perfusion with focal defects; 5-heterogeneous absence of perfusion; 6-homogeneous absence of perfusion), with the extent of the defect given as a percentage. 730 segments were evaluated. CT categorized 566 (78 %) as centrilobular, 159 (22 %) as panlobular and 5 (<1 %) as paraseptal with no normals. Scores with regards to MR perfusion patterns were: 1-0; 2-0; 3-28 (4 %); 4-425 (58 %); 5-169 (23 %); 6-108 (15 %). The predominant perfusion pattern matched as follows: 70 % centrilobular emphysema - heterogeneous perfusion with focal defects (score 4); 42 % panlobular - homogeneous absence of perfusion (score 5); and 43 % panlobular - heterogeneous absence of perfusion (score 6). MR pulmonary perfusion patterns correlate with the CT phenotype at a segmental level in patients with severe emphysema. (orig.)

  8. Assessment of the relationship between morphological emphysema phenotype and corresponding pulmonary perfusion pattern on a segmental level

    International Nuclear Information System (INIS)

    Bryant, Mark; Kauczor, Hans-Ulrich; Ley, Sebastian; Eberhardt, Ralf; Herth, Felix; Menezes, Ravi; Sedlaczek, Oliver; Ley-Zaporozhan, Julia

    2015-01-01

    Distinct morphological emphysema phenotypes were assessed by CT to show characteristic perfusion defect patterns. Forty-one patients with severe emphysema (GOLD III/IV) underwent three-dimensional high resolution computed tomography (3D-HRCT) and contrast-enhanced magnetic resonance (MR) perfusion. 3D-HRCT data was visually analyzed for emphysema phenotyping and quantification by consensus of three experts in chest-radiology. The predominant phenotype per segment was categorized as normal, centrilobular, panlobular or paraseptal. Segmental lung perfusion was visually analyzed using six patterns of pulmonary perfusion (1-normal; 2-mild homogeneous reduction in perfusion; 3-heterogeneous perfusion without focal defects; 4-heterogeneous perfusion with focal defects; 5-heterogeneous absence of perfusion; 6-homogeneous absence of perfusion), with the extent of the defect given as a percentage. 730 segments were evaluated. CT categorized 566 (78 %) as centrilobular, 159 (22 %) as panlobular and 5 (<1 %) as paraseptal with no normals. Scores with regards to MR perfusion patterns were: 1-0; 2-0; 3-28 (4 %); 4-425 (58 %); 5-169 (23 %); 6-108 (15 %). The predominant perfusion pattern matched as follows: 70 % centrilobular emphysema - heterogeneous perfusion with focal defects (score 4); 42 % panlobular - homogeneous absence of perfusion (score 5); and 43 % panlobular - heterogeneous absence of perfusion (score 6). MR pulmonary perfusion patterns correlate with the CT phenotype at a segmental level in patients with severe emphysema. (orig.)

  9. desensitisation and calcium-sensitivity in the isolated perfused rat ...

    African Journals Online (AJOL)

    Dr Olaleye

    -induced desensitisation to noradrenaline were studied in the isolated perfused rat tail artery. Responses to the activators noradrenaline (NA). (3μM) and potassium chloride (KCl) (100mM) were obtained in Ca2+-buffered saline. Activators ...

  10. Isolated limb perfusion electrochemotherapy for the treatment of an ...

    African Journals Online (AJOL)

    After completing staging procedures, the lesion was approached with surgery and intraoperative electrochemotherapy (ECT) administration of bleomycin in isolated limb perfusion. A second session of surgery and ECT was performed one month later, followed by three additional monthly sessions of ECT. During periodic ...

  11. Feasibility study on retinal vascular bypass surgery in isolated arterially perfused caprine eye model

    Science.gov (United States)

    Chen, Y; Wu, W; Zhang, X; Fan, W; Shen, L

    2011-01-01

    Purpose To investigate the feasibility of bypassing occluded segments of retinal venous main vessels in isolated, arterially perfused caprine eyes via the closed-sky vitrectomy approach using keratoprosthesis. Methods Isolated caprine eyes were used in this study. For each eye, the retinal vessel was perfused by Krebs solution via ophthalmic artery, and pars plana vitrectomy was performed using temporary keratoprosthesis. All retinal micro-vascular maneuvers were performed in a closed-sky eyeball. The main retinal vein was blocked by endodiathermy at the site of the vessel's first branching. Two openings, several millimeters apart, were created by vascular punctures in both the main vein and its branch vein wall straddling the induced occluded segment. Catheterization was achieved using a flexible polyimide tube, with each end inserted into the vessel wall opening. A sealed connection between the vessel and the tube was obtained by endodiathermy. Bypass of the occluded retinal vein segment was thus achieved, and the patency of this vascular bypass was confirmed by intravascular staining. Results Puncturing, catheterization, and endodiathermy were viable by closed-sky approach using keratoprosthesis. Bypassing of the occluded retinal main vein segment was accomplished with the combination of these maneuvers. Good results were obtained in 23 of 38 (60%) caprine eyes. Conclusions This study demonstrated that bypassing the occluded segment of retinal main vein can be successfully performed in a closed-sky eyeball model of isolated, arterially perfused caprine eye. This early work indicated that the more advanced retinal vascular bypass surgery in in vivo eye may be feasible in the future. PMID:21921946

  12. Testosterone biotransformation by the isolated perfused canine pancreas

    International Nuclear Information System (INIS)

    Fernandez-del Castillo, C.; Diaz-Sanchez, V.; Varela-Fascinetto, G.; Altamirano, A.; Odor-Morales, A.; Lopez-Medrano, R.M.; Robles-Diaz, G.

    1991-01-01

    There is strong evidence indicating that the pancreas is under the influence of sex steroid hormones, and that it may even participate in their biosynthesis and metabolism. In the present study, [3H]testosterone was perfused into the isolated canine pancreas, and measured in the effluent with several of its metabolites (5 alpha-dihydrotestosterone, androstenedione, and estradiol). Results show that testosterone is readily transformed by the canine pancreas. The main product found in the effluent is androstenedione. The testis and spleen were also perfused with [3H]testosterone and used as controls. In both cases, this hormone appeared mostly unchanged in the effluent as compared to the pancreatic perfusion (p less than 0.0001). From our data, we conclude that the canine pancreas has the capacity to transform sex steroid hormones, and could be considered an extragonadal site of sex steroid biosynthesis

  13. Complete inhibition of creatine kinase in isolated perfused rat hearts

    International Nuclear Information System (INIS)

    Fossel, E.T.; Hoefeler, H.

    1987-01-01

    Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts are able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. 31 P-NMR of the heart was carried out

  14. Testosterone biotransformation by the isolated perfused canine pancreas

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    Fernandez-del Castillo, C.; Diaz-Sanchez, V.; Varela-Fascinetto, G.; Altamirano, A.; Odor-Morales, A.; Lopez-Medrano, R.M.; Robles-Diaz, G. (Instituto Nacional de la Nutricion Salvador Zubiran, Mexico City (Mexico))

    1991-01-01

    There is strong evidence indicating that the pancreas is under the influence of sex steroid hormones, and that it may even participate in their biosynthesis and metabolism. In the present study, (3H)testosterone was perfused into the isolated canine pancreas, and measured in the effluent with several of its metabolites (5 alpha-dihydrotestosterone, androstenedione, and estradiol). Results show that testosterone is readily transformed by the canine pancreas. The main product found in the effluent is androstenedione. The testis and spleen were also perfused with (3H)testosterone and used as controls. In both cases, this hormone appeared mostly unchanged in the effluent as compared to the pancreatic perfusion (p less than 0.0001). From our data, we conclude that the canine pancreas has the capacity to transform sex steroid hormones, and could be considered an extragonadal site of sex steroid biosynthesis.

  15. Phosphorus nuclear magnetic resonance in isolated perfused rat pancreas

    International Nuclear Information System (INIS)

    Matsumoto, Takehisa; Kanno, Tomio; Seo, Yoshiteru; Murakami, Masataka; Watari, Hiroshi

    1988-01-01

    Phosphorus nuclear magnetic resonance spectroscopy was applied to measure phosphorus energy metabolites in isolated perfused rat pancreas. The gland was perfused with a modified Krebs-Henseleit solution at room temperature (25 degree C). 31 P resonances of creatine phosphate (PCr), ATP, ADP, inorganic phosphate (P i ) and phosphomonoesters (PMEs) were observed in all the preparations of pancreas. In different individual preparations, the resonance of PCr varied, but those of ATP were almost the same. The initial levels of PCr and ATP in individual preparations, however, remained almost unchanged during perfusion with the standard solution for 2 h. When the perfusion was stopped, the levels of ATP and PCr decreased, while the levels of PME and P i increased. At that time, the P i resonance shfted to a higher magnetic field, indicating that the tissue pH decreased. On reperfusion, the tissue levels of phosphorus compounds and the tissue pH were restored to their initial resting levels. Continuous infusion of 0.1 μM acetylcholine caused marked and sustained increases in the flow of pancreatic juice and protein output. During the stimulation the tissue levels of phosphorus compounds remained unchanged, while the tissue pH was decreased slightly

  16. Fully automatic registration and segmentation of first-pass myocardial perfusion MR image sequences.

    Science.gov (United States)

    Gupta, Vikas; Hendriks, Emile A; Milles, Julien; van der Geest, Rob J; Jerosch-Herold, Michael; Reiber, Johan H C; Lelieveldt, Boudewijn P F

    2010-11-01

    Derivation of diagnostically relevant parameters from first-pass myocardial perfusion magnetic resonance images involves the tedious and time-consuming manual segmentation of the myocardium in a large number of images. To reduce the manual interaction and expedite the perfusion analysis, we propose an automatic registration and segmentation method for the derivation of perfusion linked parameters. A complete automation was accomplished by first registering misaligned images using a method based on independent component analysis, and then using the registered data to automatically segment the myocardium with active appearance models. We used 18 perfusion studies (100 images per study) for validation in which the automatically obtained (AO) contours were compared with expert drawn contours on the basis of point-to-curve error, Dice index, and relative perfusion upslope in the myocardium. Visual inspection revealed successful segmentation in 15 out of 18 studies. Comparison of the AO contours with expert drawn contours yielded 2.23 ± 0.53 mm and 0.91 ± 0.02 as point-to-curve error and Dice index, respectively. The average difference between manually and automatically obtained relative upslope parameters was found to be statistically insignificant (P = .37). Moreover, the analysis time per slice was reduced from 20 minutes (manual) to 1.5 minutes (automatic). We proposed an automatic method that significantly reduced the time required for analysis of first-pass cardiac magnetic resonance perfusion images. The robustness and accuracy of the proposed method were demonstrated by the high spatial correspondence and statistically insignificant difference in perfusion parameters, when AO contours were compared with expert drawn contours. Copyright © 2010 AUR. Published by Elsevier Inc. All rights reserved.

  17. Segmentation of myocardial perfusion MR sequences with multi-band Active Appearance Models driven by spatial and temporal features

    NARCIS (Netherlands)

    Baka, N.; Milles, J.; Hendriks, E.A.; Suinesiaputra, A.; Jerosh Herold, M.; Reiber, J.H.C.; Lelieveldt, B.P.F.

    2008-01-01

    This work investigates knowledge driven segmentation of cardiac MR perfusion sequences. We build upon previous work on multi-band AAMs to integrate into the segmentation both spatial priors about myocardial shape as well as temporal priors about characteristic perfusion patterns. Different temporal

  18. Validation of a model of left ventricular segmentation for interpretation of SPET myocardial perfusion images

    International Nuclear Information System (INIS)

    Aepfelbacher, F.C.; Johnson, R.B.; Schwartz, J.G.; Danias, P.G.; Chen, L.; Parker, R.A.; Parker, A.J.

    2001-01-01

    Several models of left ventricular segmentation have been developed that assume a standard coronary artery distribution, and are currently used for interpretation of single-photon emission tomography (SPET) myocardial perfusion imaging. This approach has the potential for incorrect assignment of myocardial segments to vascular territories, possibly over- or underestimating the number of vessels with significant coronary artery disease (CAD). We therefore sought to validate a 17-segment model of myocardial perfusion by comparing the predefined coronary territory assignment with the actual angiographically derived coronary distribution. We examined 135 patients who underwent both coronary angiography and stress SPET imaging within 30 days. Individualized coronary distribution was determined by review of the coronary angiograms and used to identify the coronary artery supplying each of the 17 myocardial segments of the model. The actual coronary distribution was used to assess the accuracy of the assumed coronary distribution of the model. The sensitivities and specificities of stress SPET for detection of CAD in individual coronary arteries and the classification regarding perceived number of diseased coronary arteries were also compared between the two coronary distributions (actual and assumed). The assumed coronary distribution corresponded to the actual coronary anatomy in all but one segment (3). The majority of patients (80%) had 14 or more concordant segments. Sensitivities and specificities of stress SPET for detection of CAD in the coronary territories were similar, with the exception of the RCA territory, for which specificity for detection of CAD was better for the angiographically derived coronary artery distribution than for the model. There was 95% agreement between assumed and angiographically derived coronary distributions in classification to single- versus multi-vessel CAD. Reassignment of a single segment (segment 3) from the LCX to the LAD

  19. Validation of a model of left ventricular segmentation for interpretation of SPET myocardial perfusion images

    Energy Technology Data Exchange (ETDEWEB)

    Aepfelbacher, F.C.; Johnson, R.B.; Schwartz, J.G.; Danias, P.G. [Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Chen, L.; Parker, R.A. [Biometrics Center, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Parker, A.J. [Nuclear Medicine Division, Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States)

    2001-11-01

    Several models of left ventricular segmentation have been developed that assume a standard coronary artery distribution, and are currently used for interpretation of single-photon emission tomography (SPET) myocardial perfusion imaging. This approach has the potential for incorrect assignment of myocardial segments to vascular territories, possibly over- or underestimating the number of vessels with significant coronary artery disease (CAD). We therefore sought to validate a 17-segment model of myocardial perfusion by comparing the predefined coronary territory assignment with the actual angiographically derived coronary distribution. We examined 135 patients who underwent both coronary angiography and stress SPET imaging within 30 days. Individualized coronary distribution was determined by review of the coronary angiograms and used to identify the coronary artery supplying each of the 17 myocardial segments of the model. The actual coronary distribution was used to assess the accuracy of the assumed coronary distribution of the model. The sensitivities and specificities of stress SPET for detection of CAD in individual coronary arteries and the classification regarding perceived number of diseased coronary arteries were also compared between the two coronary distributions (actual and assumed). The assumed coronary distribution corresponded to the actual coronary anatomy in all but one segment (3). The majority of patients (80%) had 14 or more concordant segments. Sensitivities and specificities of stress SPET for detection of CAD in the coronary territories were similar, with the exception of the RCA territory, for which specificity for detection of CAD was better for the angiographically derived coronary artery distribution than for the model. There was 95% agreement between assumed and angiographically derived coronary distributions in classification to single- versus multi-vessel CAD. Reassignment of a single segment (segment 3) from the LCX to the LAD

  20. 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

  1. Quantitative hepatic CT perfusion measurement: Comparison of Couinaud's hepatic segments with dual-source 128-slice CT

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    Wang, Xuan [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Xue, Hua-dan, E-mail: bjdanna95@hotmail.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Jin, Zheng-yu, E-mail: jin_zhengyu@163.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Su, Bai-yan; Li, Zhuo; Sun, Hao; Chen, Yu; Liu, Wei [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China)

    2013-02-15

    Purpose: To compare the quantitative liver computed tomography perfusion (CTP) differences among eight hepatic segments. Materials and methods: This retrospective study was based on 72 acquired upper abdomen CTP scans for detecting suspected pancreas tumor. Patients with primary or metastatic liver tumor, any focal liver lesions except simple cyst (<3 cm in diameter), history of liver operation or splenectomy, evidence of liver cirrhosis or invasion of portal vein were excluded. The final analysis included 50 patients (M:F = 21:29, mean age = 43.2 years, 15–76 years). Arterial liver perfusion (ALP), portal-venous perfusion (PVP), total hepatic perfusion (THP = ALP + PVP), and hepatic perfusion index (HPI) of each hepatic segment were calculated and compared by means of one-way analysis of variance (ANOVA) and the Bonferonni correction method. Results: Compared to hepatic segments 5, 6, 7 and 8, segments 2 and 3 showed a tendency of higher ALPs, lower PVPs, and higher HPIs, most of which were statistically significant (p < 0.05). Hepatic segments 1 and 4 had higher mean values of ALP and HPI and lower mean values of PVP than segments 5, 6, 7 and 8 as well, although no significant differences were detected except for ALP and HPI for liver segments 1 and 7 (p = 0.001 and 0.035 respectively), and ALP for liver segments 1 and 5 (p = 0.039). Higher ALP and HPI were showed in hepatic segment 3 compared to segment 4 (p = 0.000 and 0.000 respectively). No significant differences were found for THP among eight segments. Conclusions: Intra-hepatic perfusion differences exist in normal hepatic parenchyma especially between lateral sector (segments 2 and 3) and right lobe (segments 5, 6, 7 and 8). This might have potential clinical significance in liver-perfusion-related protocol design and result analysis.

  2. Polarographic measurement of ascorbate washout in isolated perfused rabbit hearts

    International Nuclear Information System (INIS)

    Arts, T.; Kuikka, J.T.; Reneman, R.S.; Bassingthwaighte, J.B.

    1985-01-01

    To study the myocardial washout of ascorbate, the applicability of polarographic detection of ascorbate ions by a platinum electrode (sensitive area 0.03 mm2) was investigated, in both a calibration setup (sampling flow along the electrode: 100 microliter X s-1) and isolated, retrogradely perfused rabbit hearts. In the calibration setup at pH 7.4, the sensitivity of the electrode was 70 microA/mol. This sensitivity increased moderately with increasing pH (13%/unit pH) and increasing sampling flow rate (14% at an increase from 100 to 150 microliter X s-1). In the isolated hearts, ascorbate infused into the aorta was detected in a right ventricular drain by the electrode as well as by the use of 14 C-labeled ascorbate. Both recorded time courses were similar except for a scaling factor dependent on flow velocity. During continuous infusion the arteriovenous difference of ascorbate was 2 +/- 2% (SD), indicating a relatively low consumption of ascorbate by the isolated heart. The authors conclude that polarographic measurement of ascorbate in the coronary effluent of an isolated rabbit heart can be performed on-line and relatively easily

  3. Release of galanin from isolated perfused porcine adrenal glands

    DEFF Research Database (Denmark)

    Holst, J J; Ehrhart-Bornstein, M; Messell, T

    1991-01-01

    We found a high concentration of galanin in extracts of porcine adrenal glands (114 pmol/g). By immunohistochemistry, galanin was localized to groups of medullary cells previously shown to produce norepinephrine. To study mechanisms for the release of galanin, we developed the following in vitro...... model: isolated perfused porcine adrenals with intact splanchnic nerve supply. When the nerves were electrically stimulated, epinephrine and norepinephrine secretion increased 276- and 291-fold, respectively, and galanin release increased up to 1,300-fold. Acetylcholine at 10(-6) M stimulated galanin...... release, and hexamethonium almost abolished the response to nerve stimulation. Galanin infusions had no effect on epinephrine and norepinephrine secretion in concentrations of 10(-8) and 10(-7) M, but increased both cortisol and aldosterone secretion (P less than 0.05). Splanchnic nerve stimulation...

  4. Isolated thoracic perfusion with chemofiltration for progressive malignant pleural mesothelioma

    Directory of Open Access Journals (Sweden)

    Aigner KR

    2017-06-01

    Full Text Available Karl Reinhard Aigner, Emir Selak, Sabine Gailhofer Department of Surgical Oncology, Medias Klinikum, Burghausen, Germany Introduction: Therapy of malignant pleural mesothelioma and especially the adequate role of surgery in this context remain the subject of controversial discussions. Radical surgery in particular, which is associated with substantial morbidity, failed to translate into a definite survival advantage. We report on interim results of an ongoing Phase II study of regional chemotherapy in terms of isolated thoracic perfusion with chemofiltration (ITP-F.Patients and methods: Twenty-eight patients (25 male, 3 female, mean age 63.4 years with advanced pleural mesothelioma were included in this study. Isolation of the chest was achieved by insertion of a venous and arterial stop-flow balloon catheter via a femoral access. The aorta and inferior vena cava were blocked at the level of the diaphragm and the upper arms were blocked by pneumatic cuffs. Chemotherapy, consisting of 60 mg/m² cisplatin and 15 mg/m² mitoxantrone, was administered directly into the aorta. The isolated circuit was maintained for 15 minutes followed by ~45 minutes of chemofiltration with a hemoprocessor until 5 L of filtrate were reached. The endpoints of the study were overall survival and quality of life (QoL.Results: Out of 28 patients enrolled in the study, 5 had prior surgeries, 10 patients had systemic chemotherapy, and 5 patients additional irradiation. In all patients in restaging, clinical progress was noted. In all, 162 cycles were administered. Due to chemofiltration, toxicity was within tolerable limits, revealing World Health Organization grade I leucopenia and thrombocytopenia in 9 patients and mucositis grade I in 6 patients. The major surgical complication was inguinal lymphatic fistula in 40% of the cases. Gastrointestinal toxicity and/or neurotoxicity were never observed. One-year survival was 49%, 2-year and 3-year survival was 31%, and 5

  5. 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.

  6. The isolated perfused human skin flap model: A missing link in skin penetration studies?

    Science.gov (United States)

    Ternullo, Selenia; de Weerd, Louis; Flaten, Gøril Eide; Holsæter, Ann Mari; Škalko-Basnet, Nataša

    2017-01-01

    Development of effective (trans)dermal drug delivery systems requires reliable skin models to evaluate skin drug penetration. The isolated perfused human skin flap remains metabolically active tissue for up to 6h during in vitro perfusion. We introduce the isolated perfused human skin flap as a close-to-in vivo skin penetration model. To validate the model's ability to evaluate skin drug penetration the solutions of a hydrophilic (calcein) and a lipophilic (rhodamine) fluorescence marker were applied. The skin flaps were perfused with modified Krebs-Henseleit buffer (pH7.4). Infrared technology was used to monitor perfusion and to select a well-perfused skin area for administration of the markers. Flap perfusion and physiological parameters were maintained constant during the 6h experiments and the amount of markers in the perfusate was determined. Calcein was detected in the perfusate, whereas rhodamine was not detectable. Confocal images of skin cross-sections shoved that calcein was uniformly distributed through the skin, whereas rhodamine accumulated in the stratum corneum. For comparison, the penetration of both markers was evaluated on ex vivo human skin, pig skin and cellophane membrane. The proposed perfused flap model enabled us to distinguish between the penetrations of the two markers and could be a promising close-to-in vivo tool in skin penetration studies and optimization of formulations destined for skin administration. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Prevalence and pattern of abnormal myocardial perfusion in patients with isolated coronary artery ectasia: study by 99mTc-sestamibi radionuclide scintigraphy.

    Science.gov (United States)

    Ismail, Ahmed M; Rayan, Mona; Adel, Amr; Demerdash, Salah; Atef, Mohamed; Abdallah, Mohamed; Nammas, Wail

    2014-02-01

    We explored the prevalence and pattern of abnormal myocardial perfusion in patients with isolated coronary artery ectasia (CAE), as demonstrated by (99m)Tc-sestamibi scintigraphy. Prospectively, we enrolled 35 patients with angiographically documented CAE and no significant coronary obstruction, who underwent elective coronary angiography. Patients underwent Stress-rest (99m)Tc-sestamibi scintigraphy within 4 days of coronary angiography. They were divided into 2 groups: group I: with normal perfusion scan; and group II: with reversible perfusion defects. The mean age was 49.6 ± 6.9 years; 34 (97.1 %) were males. Seventy-nine (75.2 %) arteries were affected by CAE. Among 79 arteries affected by CAE, affection was diffuse in 37 (46.8 %). Thirteen (37.1 %) patients had normal perfusion scan (group I), whereas 22 (62.9 %) had reversible perfusion defects (group II). Among 22 patients with reversible perfusion defects, 20 (90.9 %) had mild and 2 (9.1 %) had moderate ischemia. Among 49 myocardial segments with reversible perfusion defects, 22 (44.9 %) were basal, 18 (36.7 %) mid-, and 9 (18.4 %) apical segments. Diffuse CAE was significantly more prevalent in group II versus group I, in all 3 major coronary arteries (p < 0.05 for all). In patients with isolated CAE who underwent elective coronary angiography, reversible perfusion defects demonstrated by (99m)Tc-sestamibi scintigraphy were rather prevalent, mostly mild, more likely to affect the basal and mid-segments of the myocardium, and more frequently associated with diffuse ectasia.

  8. 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

  9. Outcome of Patients With Adenosine-Induced ST Segment Depression and Normal Myocardial Perfusion

    International Nuclear Information System (INIS)

    El-Refaei, S.; Selim, M.

    2011-01-01

    The aim of the present study was to determine the outcome of patients with normal MPS and adenosine-induced ST segment depression. A total of 1867 patients underwent adenosine Tc99m-tetrofosmin MPS in nuclear medicine unit in Saudi German Hospital, Saudi Arabia, between January 2004 and May 2008. Their ECGs were checked for ST segment depression during adenosine infusion. All patients with ≥ 1 mm horizontal or down-sloping ST segment depression or≥ 1.5 mm up-sloping ST segment depression were included in the study. Fifty-six patients met our inclusion criteria, of which 45 (80%) were females. During the follow-up period, a total of 15 of patients ended up doing coronary angiography, either for high clinical suspicion or following a second positive MPS performed 6-18 months after the first study. Seven of them were positive for coronary artery disease and were subsequently treated with revascularization procedure, and 8 returned either normal angiography or non-obstructive coronary artery disease. Male diabetic smoking patients were more prevalent and underwent revascularization. The patients were followed up for a mean of 22.8 ±7.8 months. No cardiac deaths or myocardial infarctions were reported. It could be concluded that adenosine-induced ST segment depression in patients with normal myocardial perfusion was a benign finding and did not increase the very low risk of cardiac events in those patients. However, male smokers and/or diabetics might need further investigation. This suggestion needs further evaluation

  10. Tissue distribution of enrofloxacin after intramammary or simulated systemic administration in isolated perfused sheep udders.

    Science.gov (United States)

    López Cadenas, Cristina; Fernández Martínez, Nélida; Sierra Vega, Matilde; Diez Liébana, Maria J; Gonzalo Orden, Jose M; Sahagún Prieto, Ana M; García Vieitez, Juan J

    2012-11-01

    To determine the tissue distribution of enrofloxacin after intramammary or simulated systemic administration in isolated perfused sheep udders by measuring its concentration at various sample collection sites. 26 udders (obtained following euthanasia) from 26 healthy lactating sheep. For each isolated udder, 1 mammary gland was perfused with warmed, gassed Tyrode solution. Enrofloxacin (1 g of enrofloxacin/5 g of ointment) was administered into the perfused gland via the intramammary route or systemically via the perfusion fluid (equivalent to a dose of 5 mg/kg). Samples of the perfusate were obtained every 30 minutes for 180 minutes; glandular tissue samples were obtained at 2, 4, 6, and 8 cm from the teat base after 180 minutes. The enrofloxacin content of the perfusate and tissue samples was analyzed via high-performance liquid chromatography with UV detection. After intramammary administration, maximun perfusate enrofloxacin concentration was detected at 180 minutes and, at this time, mean tissue enrofloxacin concentration was detected and mean tissue enrofloxacin concentration was 123.80, 54.48, 36.72, and 26.42 μg/g of tissue at 2, 4, 6, and 8 cm from the teat base, respectively. Following systemic administration, perfusate enrofloxacin concentration decreased with time and, at 180 minutes, tissue enrofloxacin concentrations ranged from 40.38 to 35.58 μg/g of tissue. By 180 minutes after administration via the intramammary or systemic route in isolated perfused sheep mammary glands, mean tissue concentration of enrofloxacin was greater than the minimum inhibitory concentration required to inhibit growth of 90% of many common mastitis pathogens in sheep. Use of either route of administration (or in combination) appears suitable for the treatment of acute mastitis in sheep.

  11. The effect of perfusion and irrigation flow rate variations on NaCl efflux from the isolated, perfused head of the marine teleost, Myoxocephalus octodecimspinosus

    International Nuclear Information System (INIS)

    Claiborne, J.B.; Evans, D.H.

    1981-01-01

    In vivo branchial blood pressure and unidirectional efflux values for NaCl were determined in the marine teleost, Myoxocephalus octodecimspinosus. Utilizing an isolated, perfused head preparation, perfused at in vivo pressure levels, NaCl efflux was measured and compared to in vivo values. The effect of variations in perfusion or irrigation rates on the ion efflux across the gills of the isolated head was also studied. The efflux of 22 Na from the isolated, perfused head was found to be similar to in vivo values and dependent on perfusion flow and pressure. In vitro 36 Cl efflux was lower than the efflux from intact animals and was determined to be flow/pressure independent. Irrigation rate changes at all rates tested did not affect the unidirectional efflux of either ion. (Auth.)

  12. Effect of perfusion and irrigation flow rate variations on NaCl efflux from the isolated, perfused head of the marine teleost, Myoxocephalus octodecimspinosus

    Energy Technology Data Exchange (ETDEWEB)

    Claiborne, J.B. (Miami Univ., Coral Gables, FL (USA)); Evans, D.H. (Mt. Desert Island Biological Laboratory, Salsbury Cove, ME, USA)

    1981-06-01

    In vivo branchial blood pressure and unidirectional efflux values for NaCl were determined in the marine teleost, Myoxocephalus octodecimspinosus. Utilizing an isolated, perfused head preparation, perfused at in vivo pressure levels, NaCl efflux was measured and compared to in vivo values. The effect of variations in perfusion or irrigation rates on the ion efflux across the gills of the isolated head was also studied. The efflux of /sup 22/Na from the isolated, perfused head was found to be similar to in vivo values and dependent on perfusion flow and pressure. In vitro /sup 36/Cl efflux was lower than the efflux from intact animals and was determined to be flow/pressure independent. Irrigation rate changes at all rates tested did not affect the unidirectional efflux of either ion.

  13. Hemodynamic segmentation of brain perfusion images with delay and dispersion effects using an expectation-maximization algorithm.

    Directory of Open Access Journals (Sweden)

    Chia-Feng Lu

    Full Text Available Automatic identification of various perfusion compartments from dynamic susceptibility contrast magnetic resonance brain images can assist in clinical diagnosis and treatment of cerebrovascular diseases. The principle of segmentation methods was based on the clustering of bolus transit-time profiles to discern areas of different tissues. However, the cerebrovascular diseases may result in a delayed and dispersed local perfusion and therefore alter the hemodynamic signal profiles. Assessing the accuracy of the segmentation technique under delayed/dispersed circumstance is critical to accurately evaluate the severity of the vascular disease. In this study, we improved the segmentation method of expectation-maximization algorithm by using the results of hierarchical clustering on whitened perfusion data as initial parameters for a mixture of multivariate Gaussians model. In addition, Monte Carlo simulations were conducted to evaluate the performance of proposed method under different levels of delay, dispersion, and noise of signal profiles in tissue segmentation. The proposed method was used to classify brain tissue types using perfusion data from five normal participants, a patient with unilateral stenosis of the internal carotid artery, and a patient with moyamoya disease. Our results showed that the normal, delayed or dispersed hemodynamics can be well differentiated for patients, and therefore the local arterial input function for impaired tissues can be recognized to minimize the error when estimating the cerebral blood flow. Furthermore, the tissue in the risk of infarct and the tissue with or without the complementary blood supply from the communicating arteries can be identified.

  14. Management of isolated nonresectable liver metastases in colorectal cancer patients: a case-control study of isolated hepatic perfusion with melphalan versus systemic chemotherapy

    NARCIS (Netherlands)

    van Iersel, L. B. J.; Koopman, M.; van de Velde, C. J. H.; Mol, L.; van Persijn van Meerten, E. L.; Hartgrink, H. H.; Kuppen, P. J. K.; Vahrmeijer, A. L.; Nortier, J. W. R.; Tollenaar, R. A. E. M.; Punt, C.; Gelderblom, H.

    2010-01-01

    To compare the median overall survival of patients with isolated nonresectable liver metastases in comparable groups of patients treated with either isolated hepatic perfusion (IHP) with melphalan or systemic chemotherapy. Colorectal cancer patients with isolated liver metastases, who underwent IHP,

  15. Repair of segmental bone defect using Totally Vitalized tissue engineered bone graft by a combined perfusion seeding and culture system.

    Directory of Open Access Journals (Sweden)

    Lin Wang

    Full Text Available BACKGROUND: The basic strategy to construct tissue engineered bone graft (TEBG is to combine osteoblastic cells with three dimensional (3D scaffold. Based on this strategy, we proposed the "Totally Vitalized TEBG" (TV-TEBG which was characterized by abundant and homogenously distributed cells with enhanced cell proliferation and differentiation and further investigated its biological performance in repairing segmental bone defect. METHODS: In this study, we constructed the TV-TEBG with the combination of customized flow perfusion seeding/culture system and β-tricalcium phosphate (β-TCP scaffold fabricated by Rapid Prototyping (RP technique. We systemically compared three kinds of TEBG constructed by perfusion seeding and perfusion culture (PSPC method, static seeding and perfusion culture (SSPC method, and static seeding and static culture (SSSC method for their in vitro performance and bone defect healing efficacy with a rabbit model. RESULTS: Our study has demonstrated that TEBG constructed by PSPC method exhibited better biological properties with higher daily D-glucose consumption, increased cell proliferation and differentiation, and better cell distribution, indicating the successful construction of TV-TEBG. After implanted into rabbit radius defects for 12 weeks, PSPC group exerted higher X-ray score close to autograft, much greater mechanical property evidenced by the biomechanical testing and significantly higher new bone formation as shown by histological analysis compared with the other two groups, and eventually obtained favorable healing efficacy of the segmental bone defect that was the closest to autograft transplantation. CONCLUSION: This study demonstrated the feasibility of TV-TEBG construction with combination of perfusion seeding, perfusion culture and RP technique which exerted excellent biological properties. The application of TV-TEBG may become a preferred candidate for segmental bone defect repair in orthopedic and

  16. Calculating regional tissue volume for hyperthermic isolated limb perfusion: Four methods compared.

    Science.gov (United States)

    Cecchin, D; Negri, A; Frigo, A C; Bui, F; Zucchetta, P; Bodanza, V; Gregianin, M; Campana, L G; Rossi, C R; Rastrelli, M

    2016-12-01

    Hyperthermic isolated limb perfusion (HILP) can be performed as an alternative to amputation for soft tissue sarcomas and melanomas of the extremities. Melphalan and tumor necrosis factor-alpha are used at a dosage that depends on the volume of the limb. Regional tissue volume is traditionally measured for the purposes of HILP using water displacement volumetry (WDV). Although this technique is considered the gold standard, it is time-consuming and complicated to implement, especially in obese and elderly patients. The aim of the present study was to compare the different methods described in the literature for calculating regional tissue volume in the HILP setting, and to validate an open source software. We reviewed the charts of 22 patients (11 males and 11 females) who had non-disseminated melanoma with in-transit metastases or sarcoma of the lower limb. We calculated the volume of the limb using four different methods: WDV, tape measurements and segmentation of computed tomography images using Osirix and Oncentra Masterplan softwares. The overall comparison provided a concordance correlation coefficient (CCC) of 0.92 for the calculations of whole limb volume. In particular, when Osirix was compared with Oncentra (validated for volume measures and used in radiotherapy), the concordance was near-perfect for the calculation of the whole limb volume (CCC = 0.99). With methods based on CT the user can choose a reliable plane for segmentation purposes. CT-based methods also provides the opportunity to separate the whole limb volume into defined tissue volumes (cortical bone, fat and water). Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Sulphonylurea drugs reduce hypoxic damage in the isolated perfused rat kidney.

    Science.gov (United States)

    Engbersen, R; Moons, M M; Wouterse, A C; Dijkman, H B; Kramers, C; Smits, P; Russel, F G

    2000-08-01

    Sulphonylurea drugs have been shown to protect against hypoxic damage in isolated proximal tubules of the kidney. In the present study we investigated whether these drugs can protect against hypoxic damage in a whole kidney preparation. Tolbutamide (200 microM) and glibenclamide (10 microM) were applied to the isolated perfused rat kidney prior to changing the gassing from oxygen to nitrogen for 30 min. Hypoxic perfusions resulted in an increased fractional excretion of glucose (FE % glucose 14.3+/-1.5 for hypoxic perfusions vs 4.9+/-1.6 for normoxic perfusions, mean +/- s.e. mean, P<0.05), which could be completely restored by 200 microM tolbutamide (5.7+/-0.4 for tolbutamide vs 14.3+/-1.5 for untreated hypoxic kidneys, P<0.01). Furthermore, tolbutamide reduced the total amount of LDH excreted in the urine (220+/-100 mU for tolbutamide vs. 1220+/-160 mU for untreated hypoxic kidneys, P<0.01). Comparable results were obtained with glibenclamide (10 microM). In agreement with the effect on functional parameters, ultrastructural analysis of proximal tubules showed increased brush border preservation in tolbutamide treated kidneys compared to untreated hypoxic kidneys. We conclude that glibenclamide and tolbutamide are both able to reduce hypoxic damage to proximal tubules in the isolated perfused rat kidney when applied in the appropriate concentrations.

  18. A semi-automated volumetric software for segmentation and perfusion parameter quantification of brain tumors using 320-row multidetector computed tomography: a validation study

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Soo Young; Suh, Sangil; Ryoo, Inseon; Park, Arim; Seol, Hae Young [Korea University Guro Hospital, Department of Radiology, Seoul (Korea, Republic of); Noh, Kyoung Jin [Soonchunhyang University, Department of Electronic Engineering, Asan (Korea, Republic of); Shim, Hackjoon [Toshiba Medical Systems Korea Co., Seoul (Korea, Republic of)

    2017-05-15

    We developed a semi-automated volumetric software, NPerfusion, to segment brain tumors and quantify perfusion parameters on whole-brain CT perfusion (WBCTP) images. The purpose of this study was to assess the feasibility of the software and to validate its performance compared with manual segmentation. Twenty-nine patients with pathologically proven brain tumors who underwent preoperative WBCTP between August 2012 and February 2015 were included. Three perfusion parameters, arterial flow (AF), equivalent blood volume (EBV), and Patlak flow (PF, which is a measure of permeability of capillaries), of brain tumors were generated by a commercial software and then quantified volumetrically by NPerfusion, which also semi-automatically segmented tumor boundaries. The quantification was validated by comparison with that of manual segmentation in terms of the concordance correlation coefficient and Bland-Altman analysis. With NPerfusion, we successfully performed segmentation and quantified whole volumetric perfusion parameters of all 29 brain tumors that showed consistent perfusion trends with previous studies. The validation of the perfusion parameter quantification exhibited almost perfect agreement with manual segmentation, with Lin concordance correlation coefficients (ρ {sub c}) for AF, EBV, and PF of 0.9988, 0.9994, and 0.9976, respectively. On Bland-Altman analysis, most differences between this software and manual segmentation on the commercial software were within the limit of agreement. NPerfusion successfully performs segmentation of brain tumors and calculates perfusion parameters of brain tumors. We validated this semi-automated segmentation software by comparing it with manual segmentation. NPerfusion can be used to calculate volumetric perfusion parameters of brain tumors from WBCTP. (orig.)

  19. A semi-automated volumetric software for segmentation and perfusion parameter quantification of brain tumors using 320-row multidetector computed tomography: a validation study.

    Science.gov (United States)

    Chae, Soo Young; Suh, Sangil; Ryoo, Inseon; Park, Arim; Noh, Kyoung Jin; Shim, Hackjoon; Seol, Hae Young

    2017-05-01

    We developed a semi-automated volumetric software, NPerfusion, to segment brain tumors and quantify perfusion parameters on whole-brain CT perfusion (WBCTP) images. The purpose of this study was to assess the feasibility of the software and to validate its performance compared with manual segmentation. Twenty-nine patients with pathologically proven brain tumors who underwent preoperative WBCTP between August 2012 and February 2015 were included. Three perfusion parameters, arterial flow (AF), equivalent blood volume (EBV), and Patlak flow (PF, which is a measure of permeability of capillaries), of brain tumors were generated by a commercial software and then quantified volumetrically by NPerfusion, which also semi-automatically segmented tumor boundaries. The quantification was validated by comparison with that of manual segmentation in terms of the concordance correlation coefficient and Bland-Altman analysis. With NPerfusion, we successfully performed segmentation and quantified whole volumetric perfusion parameters of all 29 brain tumors that showed consistent perfusion trends with previous studies. The validation of the perfusion parameter quantification exhibited almost perfect agreement with manual segmentation, with Lin concordance correlation coefficients (ρ c ) for AF, EBV, and PF of 0.9988, 0.9994, and 0.9976, respectively. On Bland-Altman analysis, most differences between this software and manual segmentation on the commercial software were within the limit of agreement. NPerfusion successfully performs segmentation of brain tumors and calculates perfusion parameters of brain tumors. We validated this semi-automated segmentation software by comparing it with manual segmentation. NPerfusion can be used to calculate volumetric perfusion parameters of brain tumors from WBCTP.

  20. Toxicity and Kinetics of (3H)Microcystin-LR in Isolated Perfused Rat Livers

    Science.gov (United States)

    1990-03-20

    with a Waters 490 multiwavelength detector, as described by Robinson et al. (1989). A C-18 column (Adsorbosphere HS, 4.6 x 250 mm, 5 Am, Alltech ...1988). The isolated perfused liver has several advantages over other model systems for the study of hepatotoxins. Unlike the in-vitro cell systems

  1. Major amputation for intractable extremity melanoma after failure of isolated limb perfusion

    NARCIS (Netherlands)

    Kapma, M. R.; Vrouenraets, B. C.; Nieweg, O. E.; van Geel, A. N.; Noorda, E. M.; Eggermont, A. M. M.; Kroon, B. B. R.

    2005-01-01

    AIM: The aim of this study was to analyse indications and results of amputation for intractable extremity melanoma after failure of isolated limb perfusion (ILP). METHODS: Between 1978 and 2001, 451 patients with loco-regional advanced extremity melanoma underwent 505 ILPs. Amputation of the

  2. Cell-swelling-induced taurine release from isolated perfused rat liver

    NARCIS (Netherlands)

    Brand, H. S.; Meijer, A. J.; Gustafson, L. A.; Jörning, G. G.; Leegwater, A. C.; Maas, M. A.; Chamuleau, R. A.

    1994-01-01

    Astrocytes and lymphocytes are able to release significant amounts of taurine during periods of hypotonicity to reduce the increase in cell volume. To investigate this mechanism in the liver, we studied the release of free amino acids from isolated perfused rat liver during hypotonicity. The

  3. 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.

  4. 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)

  5. Effects of vasopressin on the isolated perfused human collecting tubule.

    Science.gov (United States)

    Yanagawa, N; Trizna, W; Bar-Khayim, Y; Fine, L G

    1981-05-01

    Cortical collecting tubules (CCT) were dissected from the surviving normal tissue of human kidneys removed at operation for either carcinoma or calculus. These CCT's were perfused in vitro shortly after the nephrectomy was performed. Transtubular potential differences in different tubules varied from +3.2 to -2.0 mV and were reduced towards zero by lowering the temperature or by adding ouabain to the bath. In the absence of vasopressin, tubules were essentially impermeable to water with extremely low net water fluxes even in the presence of a transtubular osmotic gradient. Addition of vasopressin to the bath caused the transtubular osmotic water permeability coefficient to increase to values of 125, 175, and 155 X 10(-4) cm/sec in three tubules thus studied. These results demonstrate close similarities between the human CCT and the more extensively studied rabbit CCT.

  6. Localisation and neural control of the release of calcitonin gene-related peptide (CGRP) from the isolated perfused porcine ileum

    DEFF Research Database (Denmark)

    Rasmussen, T N; Schmidt, P; Poulsen, S S

    2001-01-01

    was abolished by infusion of hexamethonium (3x10(-5) M). Infusion of capsaicin (10(-5) M) caused a significant increase in the release of CGRP-LI to 485+/-82% of basal output (n=5). Our results suggest a dual origin of CGRP innervation of the porcine ileum (intrinsic and extrinsic). The intrinsic CGRP neurons...... extracts, CGRP-LI corresponded entirely to porcine CGRP plus smaller amounts of oxidised CGRP. Using isolated vascularly perfused segments of the ileum, we studied the release of CGRP-LI in response to electrical stimulation of the mixed extrinsic periarterial nerves and to infusion of different...... receive excitatory input by parasympathetic, possibly vagal, preganglionic fibres, via release of acetylcholine acting on nicotinic receptors. The stimulatory effect of capsaicin suggests that CGRP is also released from extrinsic sensory neurons....

  7. NMR study of damage on isolated perfused rat heart exposed to ischemia and hypoxia

    International Nuclear Information System (INIS)

    Luo Xuechun; Yan Yongbin; Zhang Riqing; Fan Lili

    2001-01-01

    Myocardial ischemia is the most common and primary cause of myocardium damage. Numerous conventional techniques and methods have been developed for ischemia and reperfusion studies. However, because of damage to the heart sample, most of these techniques can not be used to continuously monitor the full dynamic course of the myocardial metabolic pathway. The nuclear magnetic resonance (NMR) surface coil technique, which overcomes the limitations of conventional instrumentation, can be used to quantitatively study every stage of the perfused heart (especially after perfusion stoppage) continuously, dynamically, and without damage under normal or designed physiological conditions at the molecular level. In this paper, 31 P-NMR was used to study the effects of ischemia and hypoxia on isolated perfused hearts. The results show that complete hypoxia caused more severe functional damage to the myocardial cells than complete ischemia

  8. New method of isolation and perfusion of rat pancreas for phosphorus nucletic resonance study

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Takehisa; Kanno, Tomio; Murakami, Masataka; Watari, Hiroshi; Seo, Yoshiteru

    1988-02-01

    Phosphorus nuclear magnetic resonance (/sup 31/P-NMR) was applied to measure phosphorus metabolites in the pancreas. Rat pancreatic gland was isolated and perfused with a modified Krebs-Henseleit solution at room temperature (25 deg C). Removal of the duodenum from the pancreas made it possible to record /sup 31/P-NMR spectra only from the pancreatic tissue. /sup 31/P signals of creatine phosphate (PCr), ATP and inorganic phosphate (Pi) were observed in all the glands. In different individual glands, the Signal intensity of PCr varied, but those of ATP were almost the same. The initial levels of all the phosphorus metabolites in individual glands remained almost unchanged during perfusion with the standard solution for 2 hours. When the perfusion was stopped, signal intensity of ATP and PCr decreased while Pi resonance increased and shifted to a higher magnetic field, indicating tissue acidification. On re-perfusion, each resonance and tissue pH were restored to the respective initial resting levels. Continuous stimulation with 0.3 ..mu..M acetylcholine (ACh) or 0.1 nM CCK-8 caused a markedly larger increase in pancreatic exocrine secretion than that observed in the perfused pancreas which was prepared by the previous method. Continuous stimulation with 0.1 ..mu..M ACh caused a marked and sustained increase in pancreatic exocrine secretion. During the stimulation, the resonances of phosphorus energy metabolites and tissue pH remained almost unchanged. These results indicate that the isolated perfused rat pancreas which is prepared by our new method is a useful preparation for analysis of secretion-metabolism coupling in the exocrine pancreas.

  9. Uptake, incorporation and metabolism of (3H)triolein in the isolated perfused rabbit heart

    International Nuclear Information System (INIS)

    Weis, M.T.; Palazzo, A.J.; Williams, J.L. Jr.; Malik, K.U.

    1990-01-01

    The purpose of these experiments was to study the uptake and metabolism of exogenous triglyceride in the isolated perfused rabbit heart. When infused into the rabbit heart, [9,10-3H(N)]triolein was retained and incorporated into a lipid fraction that had the chromatographic mobility of authentic triolein. Incorporation of labeled triolein was not likely to be the result of a lipoprotein lipase-mediated lipolysis/resynthesis cycle, since: (i) The distribution of radioactivity following administration of [3H]oleic acid was markedly different from the distribution of radioactivity following the administration of [3H]triolein; (ii) heparin was administered to the rabbits at the time of sacrifice; and (iii) the hearts were perfused with a protein-free buffer for 20 min prior to the labelling period. When isoproterenol was administered to hearts labelled with [3H]triolein, there was an increased output of total radioactivity, composed of labelled free fatty acids, diacylglycerol and monoacylglycerol. In these same hearts, there was an increased output of glycerol in response to isoproterenol. However, following the administration of bradykinin or angiotensin II, neither the radioactivity nor the glycerol content of the perfusate was changed. These data suggest that [3H]triolein is selectively incorporated into the triglyceride pool of the isolated perfused rabbit heart. Furthermore, this [3H]triolein is available to hormonally-activated lipolytic enzymes

  10. Radiation exposure to surgical staff during hyperthermic isolated limb perfusion with 99m Technetium labeled red blood cells

    DEFF Research Database (Denmark)

    Kristoffersen, Ulrik Sloth; Straalman, Kristina; Schmidt, Grethe

    2009-01-01

    PURPOSE: Hyperthermic isolated limb perfusion (HILP) is an effective method in the treatment of recurrent melanomas and soft tissue sarcomas. To avoid systemic toxicity, leakage from the limb perfusate into the systemic circulation is real-time monitored by administration of a radioactive agent...

  11. EFFECT OF ETHANOL ON HEPATOBILIARY TRANSPORT OF CATIONIC DRUGS - A STUDY IN THE ISOLATED-PERFUSED RAT-LIVER, RAT HEPATOCYTES AND RAT MITOCHONDRIA

    NARCIS (Netherlands)

    STEEN, H; MEIJER, DKF; Merema, M.T.

    The effect of ethanol on the hepatic uptake of various cationic drugs was studied in isolated perfused rat livers, isolated rat hepatocytes and isolated rat liver mitochondria. In isolated rat hepatocytes and in isolated perfused rat livers, the uptake of the model organic cation

  12. Percutaneous Isolated Hepatic Perfusion for the Treatment of Unresectable Liver Malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Burgmans, Mark C., E-mail: m.c.burgmans@lumc.nl [Leiden University Medical Centre, Department of Radiology (Netherlands); Leede, Eleonora M. de, E-mail: e.m.de-leede@lumc.nl [Leiden University Medical Centre, Department of Surgery (Netherlands); Martini, Christian H., E-mail: c.h.martini@lumc.nl [Leiden University Medical Centre, Department of Anesthesiology (Netherlands); Kapiteijn, Ellen, E-mail: h.w.kapiteijn@lumc.nl [Leiden University Medical Centre, Department of Medical Oncology (Netherlands); Vahrmeijer, Alexander L., E-mail: a.l.vahrmeijer@lumc.nl [Leiden University Medical Centre, Department of Surgery (Netherlands); Erkel, Arian R. van, E-mail: a.r.van-erkel@lumc.nl [Leiden University Medical Centre, Department of Radiology (Netherlands)

    2016-06-15

    Liver malignancies are a major burden of disease worldwide. The long-term prognosis for patients with unresectable tumors remains poor, despite advances in systemic chemotherapy, targeted agents, and minimally invasive therapies such as ablation, chemoembolization, and radioembolization. Thus, the demand for new and better treatments for malignant liver tumors remains high. Surgical isolated hepatic perfusion (IHP) has been shown to be effective in patients with various hepatic malignancies, but is complex, associated with high complication rates and not repeatable. Percutaneous isolated liver perfusion (PHP) is a novel minimally invasive, repeatable, and safer alternative to IHP. PHP is rapidly gaining interest and the number of procedures performed in Europe now exceeds 200. This review discusses the indications, technique and patient management of PHP and provides an overview of the available data.

  13. Percutaneous Isolated Hepatic Perfusion for the Treatment of Unresectable Liver Malignancies

    International Nuclear Information System (INIS)

    Burgmans, Mark C.; Leede, Eleonora M. de; Martini, Christian H.; Kapiteijn, Ellen; Vahrmeijer, Alexander L.; Erkel, Arian R. van

    2016-01-01

    Liver malignancies are a major burden of disease worldwide. The long-term prognosis for patients with unresectable tumors remains poor, despite advances in systemic chemotherapy, targeted agents, and minimally invasive therapies such as ablation, chemoembolization, and radioembolization. Thus, the demand for new and better treatments for malignant liver tumors remains high. Surgical isolated hepatic perfusion (IHP) has been shown to be effective in patients with various hepatic malignancies, but is complex, associated with high complication rates and not repeatable. Percutaneous isolated liver perfusion (PHP) is a novel minimally invasive, repeatable, and safer alternative to IHP. PHP is rapidly gaining interest and the number of procedures performed in Europe now exceeds 200. This review discusses the indications, technique and patient management of PHP and provides an overview of the available data.

  14. Metabolism of 1-[14C]nitropyrene in isolated perfused rat livers

    International Nuclear Information System (INIS)

    Bond, J.A.; Medinsky, M.A.; Dutcher, J.S.

    1984-01-01

    1-Nitropyrene (1-NP), a constituent of diesel exhaust, is carcinogenic to rats and is a bacterial and mammalian mutagen. Biliary and fecal excretion of 1-NP metabolites are the major routes of excretion in rats, suggesting that hepatic metabolism plays a dominant role in determining the biological fate of 1-NP. The purpose of this investigation was to quantitate 1-[14C]NP metabolites formed in isolated perfused rat livers and excreted in bile from rats. Perfused rat livers displayed a capacity for oxidation, reduction, acetylation, and conjugation of 1-NP (or its metabolites). Reduction of 1-NP followed by N-acetylation was the major metabolic pathway observed in the perfused livers. Acetylaminopyrene (AAP) was the major metabolite detected, with total quantities (150 nmol) accounting for about 60% of the total 1-[14C]NP dose (258 nmol) added to the perfusate. Considerably smaller quantities of aminopyrene and hydroxynitropyrenes were also detected. Livers perfused with 1-[14C]NP excreted about 36 nmol equivalents of 1-[14C]NP (12% of the total 1-NP dose) in bile after 60 min. Some of the biliary metabolites were tentatively identified as metabolites of the mercapturic acid pathway. The spectrum of biliary metabolites was qualitatively identical to that seen in bile from intact rats. Quantities of 14C covalently bound to hepatic macromolecules from perfused livers were 0.4 nmol 1-NP eq/g liver. The data from this study indicate that the liver may be an important site for metabolism of 1-NP

  15. Monitoring system for isolated limb perfusion based on a portable gamma camera

    International Nuclear Information System (INIS)

    Orero, A.; Muxi, A.; Rubi, S.; Duch, J.; Vidal-Sicart, S.; Pons, F.; Roe, N.; Rull, R.; Pavon, N.; Pavia, J.

    2009-01-01

    Background: The treatment of malignant melanoma or sarcomas on a limb using extremity perfusion with tumour necrosis factor (TNF-α) and melphalan can result in a high degree of systemic toxicity if there is any leakage from the isolated blood territory of the limb into the systemic vascular territory. Leakage is currently controlled by using radiotracers and heavy external probes in a procedure that requires continuous manual calculations. The aim of this work was to develop a light, easily transportable system to monitor limb perfusion leakage by controlling systemic blood pool radioactivity with a portable gamma camera adapted for intraoperative use as an external probe, and to initiate its application in the treatment of MM patients. Methods: A special collimator was built for maximal sensitivity. Software for acquisition and data processing in real time was developed. After testing the adequacy of the system, it was used to monitor limb perfusion leakage in 16 patients with malignant melanoma to be treated with perfusion of TNF-α and melphalan. Results: The field of view of the detector system was 13.8 cm, which is appropriate for the monitoring, since the area to be controlled was the precordial zone. The sensitivity of the system was 257 cps/MBq. When the percentage of leakage reaches 10% the associated absolute error is ±1%. After a mean follow-up period of 12 months, no patients have shown any significant or lasting side-effects. Partial or complete remission of lesions was seen in 9 out of 16 patients (56%) after HILP with TNF-α and melphalan. Conclusion: The detector system together with specially developed software provides a suitable automatic continuous monitoring system of any leakage that may occur during limb perfusion. This technique has been successfully implemented in patients for whom perfusion with TNF-α and melphalan has been indicated. (orig.)

  16. Monitoring system for isolated limb perfusion based on a portable gamma camera

    Energy Technology Data Exchange (ETDEWEB)

    Orero, A.; Muxi, A.; Rubi, S.; Duch, J. [Servei de Medicina Nuclear, Hospital Clinic, Barcelona (Spain); Vidal-Sicart, S.; Pons, F. [Servei de Medicina Nuclear, Hospital Clinic, Barcelona (Spain); Inst. d' Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona (Spain); Red Tematica de Investigacion Cooperativa en Cancer (RTICC), Barcelona (Spain); Roe, N. [Servei de Medicina Nuclear, Hospital Clinic, Barcelona (Spain); CIBER de Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain); Rull, R. [Servei de Cirurgia, Hospital Clinic, Barcelona (Spain); Pavon, N. [Inst. de Fisica Corpuscular, CSIC - UV, Valencia (Spain); Pavia, J. [Servei de Medicina Nuclear, Hospital Clinic, Barcelona (Spain); Inst. d' Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona (Spain); CIBER de Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain)

    2009-07-01

    Background: The treatment of malignant melanoma or sarcomas on a limb using extremity perfusion with tumour necrosis factor (TNF-{alpha}) and melphalan can result in a high degree of systemic toxicity if there is any leakage from the isolated blood territory of the limb into the systemic vascular territory. Leakage is currently controlled by using radiotracers and heavy external probes in a procedure that requires continuous manual calculations. The aim of this work was to develop a light, easily transportable system to monitor limb perfusion leakage by controlling systemic blood pool radioactivity with a portable gamma camera adapted for intraoperative use as an external probe, and to initiate its application in the treatment of MM patients. Methods: A special collimator was built for maximal sensitivity. Software for acquisition and data processing in real time was developed. After testing the adequacy of the system, it was used to monitor limb perfusion leakage in 16 patients with malignant melanoma to be treated with perfusion of TNF-{alpha} and melphalan. Results: The field of view of the detector system was 13.8 cm, which is appropriate for the monitoring, since the area to be controlled was the precordial zone. The sensitivity of the system was 257 cps/MBq. When the percentage of leakage reaches 10% the associated absolute error is {+-}1%. After a mean follow-up period of 12 months, no patients have shown any significant or lasting side-effects. Partial or complete remission of lesions was seen in 9 out of 16 patients (56%) after HILP with TNF-{alpha} and melphalan. Conclusion: The detector system together with specially developed software provides a suitable automatic continuous monitoring system of any leakage that may occur during limb perfusion. This technique has been successfully implemented in patients for whom perfusion with TNF-{alpha} and melphalan has been indicated. (orig.)

  17. Compartment analysis of 125I-labelled albumin washout from coronary vessels of isolated perfused hearts

    International Nuclear Information System (INIS)

    Cheng Eap Ng; Seh-Hoon Song

    1978-01-01

    Albumin labelled with 125 I was used as a tracer to investigate the washout kinetics of plasma from the coronary circulation of isolated perfused feline hearts. Compartmentalization with experimental results showed at least two compartments. The model was compared with a three-compartment model found previously for red blood cells. The results indicate that there is a separation of plasma and RBC in the coronary microcirculation. (author)

  18. Chamber-specific effects of hypokalaemia on ventricular arrhythmogenicity in isolated, perfused guinea-pig heart

    DEFF Research Database (Denmark)

    Osadchii, Oleg E; Bentzen, Bo Hjorth; Olesen, Søren-Peter

    2009-01-01

    of hypokalaemic perfusion (2.5 mm K(+) for 30 min) were assessed in isolated guinea-pig heart preparations using simultaneous recordings of volume-conducted electrocardiogram and monophasic action potentials from six ventricular epicardial sites. Effective refractory periods, ventricular fibrillation thresholds...... for re-entrant tachyarrhythmias. Taken together, these findings suggest that proarrhythmic effects of hypokalaemia are mostly attributed to increased LV arrhythmogenicity in the guinea-pig heart....

  19. 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

  20. Correlation between melphalan pharmacokinetics and hepatic toxicity following hyperthermic isolated liver perfusion for unresectable metastatic disease.

    Science.gov (United States)

    Mocellin, Simone; Pilati, Pierluigi; Da Pian, Pierpaolo; Forlin, Marco; Corazzina, Susanna; Rossi, Carlo Riccardo; Innocente, Federico; Ori, Carlo; Casara, Dario; Ujka, Francesca; Nitti, Donato; Lise, Mario

    2007-02-01

    In the present work, we report on the results of our pilot study of hyperthermic isolated hepatic perfusion (IHP) with melphalan alone for patients with unresectable metastatic liver tumors refractory to conventional treatments, with particular regard to the correlation between pharmacokinetic findings and hepatic toxicity. Inclusion criteria were unresectable liver metastases, hepatic parenchyma replacement isolation of the liver and drug distribution volumes of the perfusion circuit were assessed by a radiolabeled albumin-based method. Drug concentrations in perfusate and plasma were measured by means of high-performance liquid chromatography (HPLC). Twenty patients with unresectable liver metastases underwent IHP. No intraoperative mortality occurred. Treatment-related systemic toxicity was minimal and reversible. Three patients (15%) experienced grade 4 hepatic toxicity and died due to liver failure and subsequent multiorgan failure. Other six patients had significant (grade 3-4) but transitory hepatic toxicity. Complete and partial responses were observed in three and nine out of 17 evaluable patients, respectively (overall response rate = 70%). The pharmacokinetics study showed a 3% mean perfusate-to-plasma drug leakage (range 1-6%). Logistic regression analysis showed that drug concentration in the perfusate circuit, but not preoperative tests, significantly and independently correlated with hepatic toxicity (P = 0.028). Following melphalan-based IHP, objective tumor regression could be observed in a remarkable percentage of patients refractory to standard treatments. However, hepatic toxicity and related mortality were significant. Our findings suggest that drug dosage personalization based on the measurement of drug distribution volumes might minimize

  1. Importance of tissue perfusion in ST segment elevation myocardial infarction patients undergoing reperfusion strategies: role of adenosine.

    Science.gov (United States)

    Forman, Mervyn B; Jackson, Edwin K

    2007-11-01

    High risk ST segment elevation myocardial infarction (STEMI) patients undergoing reperfusion therapy continue to exhibit significant morbidity and mortality due in part to myocardial reperfusion injury. Importantly, preclinical studies demonstrate that progressive microcirculatory failure (the "no-reflow" phenomenon) contributes significantly to myocardial reperfusion injury. Diagnostic techniques to measure tissue perfusion have validated this concept in humans, and it is now clear that abnormal tissue perfusion occurs frequently in STEMI patients undergoing reperfusion therapy. Moreover, because tissue perfusion correlates poorly with epicardial blood flow (TIMI flow grade), clinical studies show that tissue perfusion is an independent predictor of early and late mortality in STEMI patients and is associated with infarct size, ventricular function, CHF and ventricular arrhythmias. The mechanisms responsible for abnormal tissue perfusion are multifactorial and include both mechanical obstruction and vasoconstrictor humoral factors. Adenosine, an endogenous nucleoside, maintains microcirculatory flow following reperfusion by activating four well-characterized extracellular receptors. Because activation of adenosine receptors attenuates the mechanical and functional mechanisms leading to the "no reflow" phenomenon and activates other cardioprotective pathways as well, it is not surprising that both experimental and clinical studies show striking myocardial salvage with intravenous infusions of adenosine administered in the peri-reperfusion period. For example, a post hoc analysis of the AMISTAD II trial indicates a significant reduction in 1 and 6-month mortality in STEMI patients undergoing reperfusion therapy who are treated with adenosine within 3 hours of symptoms. In conclusion, adenosine's numerous cardioprotective effects, including attenuation of the "no-reflow" phenomenon, support its use in high risk STEMI undergoing reperfusion.

  2. Initial intramuscular perfusion pressure predicts early skeletal muscle function following isolated tibial fractures

    Directory of Open Access Journals (Sweden)

    Haas Norbert P

    2008-04-01

    Full Text Available Abstract Background The severity of associated soft tissue trauma in complex injuries of the extremities guides fracture treatment and decisively determines patient's prognosis. Trauma-induced microvascular dysfunction and increased tissue pressure is known to trigger secondary soft tissue damage and seems to adversely affect skeletal muscle function. Methods 20 patients with isolated tibial fractures were included. Blood pressure and compartment pressure (anterior and deep posterior compartment were measured continuously up to 24 hours. Corresponding perfusion pressure was calculated. After 4 and 12 weeks isokinetic muscle peak torque and mean power of the ankle joint in dorsal and plantar flexion were measured using a Biodex dynamometer. Results A significant inverse correlation between the anterior perfusion pressure at 24 hours and deficit in dorsiflexion at 4 weeks was found for both, the peak torque (R = -0.83; p Conclusion The functional relationship between the decrease in intramuscular perfusion pressures and muscle performance in the early rehabilitation period indicate a causative and prognostic role of early posttraumatic microcirculatory derangements and skeletal muscle function. Therapeutic concepts aimed at effective muscle recovery, early rehabilitation, and decreased secondary tissue damage, should consider the maintenance of an adequate intramuscular perfusion pressure.

  3. Isolated Right Segmental Hepatic Duct Injury Following Laparoscopic Cholecystectomy

    International Nuclear Information System (INIS)

    Perini, Rafael F.; Uflacker, Renan; Cunningham, John T.; Selby, J. Bayne; Adams, David

    2005-01-01

    Purpose. Laparoscopic cholecystectomy (LC) is the treatment of choice for gallstones. There is an increased incidence of bile duct injuries in LC compared with the open technique. Isolated right segmental hepatic duct injury (IRSHDI) represents a challenge not only for management but also for diagnosis. We present our experience in the management of IRSHDI, with long-term follow-up after treatment by a multidisciplinary approach. Methods. Twelve consecutive patients (9 women, mean age 48 years) were identified as having IRSHDI. Patients' demographics, clinical presentation, management and outcome were collected for analysis. The mean follow-up was 44 months (range 2-90 months). Results. Three patients had the LC immediately converted to open surgery without repair of the biliary injury before referral. Treatments before referral included endoscopic retrograde cholangiopancreatography (ERCP), percutaneous drainage and surgery, isolated or in combination. The median interval from LC to referral was 32 days. Eleven patients presented with biliary leak and biloma, one with obstruction of an isolated right hepatic segment. Post-referral management of the biliary lesion used a combination of ERCP stenting, percutaneous drainage and stent placement and surgery. In 6 of 12 patients ERCP was the first procedure, and in only one case was IRSHDI identified. In 6 patients, percutaneous transhepatic cholangiography (PTC) was performed first and an isolated right hepatic segment was demonstrated in all. The final treatment modality was endoscopic management and/or percutaneous drainage and stenting in 6 patients, and surgery in 6. The mean follow-up was 44 months. No mortality or significant morbidity was observed. Conclusion. Successful management of IRSHDI after LC requires adequate identification of the lesion, and multidisciplinary treatment is necessary. Half of the patients can be treated successfully by nonsurgical procedures

  4. Isolated Liver Perfusion Using Percutaneous Methods:[ql An Experimental Study in the Pig

    International Nuclear Information System (INIS)

    Harnek, Jan; Cwikiel, Wojciech; Bergqvist, Lennart; Persson, Bo; Stridbeck, Hans

    1996-01-01

    Purpose: To develop a method for isolated perfusion of the liver using radiological methods. Methods: Twenty-one pigs, weighing about 20 kg, were divided into three groups. By transjugular and transfemoral approaches two occlusion balloons were placed in the inferior vena cava cranial and caudal, respectively, to the origin of the hepatic veins. One occlusion balloon was placed transfemorally in the common hepatic artery. Another occlusion balloon was inserted in the main branch of the portal vein via the transjugular-transhepatic approach in 11 pigs (groups 1 and 2), and in 10 pigs (group 3) by a percutaneous transhepatic route. After inflation of the balloons, patency of the isolated liver circulation was evaluated by recirculation of 99 Tc m -labelled human albumin during 30 min. Blood tests were obtained after 1, 3, 5, 10, 15, and 30 min to evaluate leakage from the liver to the systemic circulation. Results: Increasing leakage to the systemic circulation from the isolated liver circulation was observed in groups 1 and 2. In the third group the leakage was less than 10%. Conclusion: In an experimental animal model, isolated perfusion of the liver with minor leakage to the systemic circulation may be achieved using radiological methods

  5. Conversion of p-tyrosine to p-tyramine in the isolated perfused rat kidney: Modulation by perfusate concentrations of p-tyrosine

    International Nuclear Information System (INIS)

    Brier, M.E.; Bowsher, R.R.; Henry, D.P.; Mayer, P.R.

    1991-01-01

    The authors used the isolated perfused rat kidney to evaluate the role of renal decarboxylation of p-tyrosine as the source of urinary p-tyramine. Kidneys were perfused with concentrations of p-tyrosine ranging from 0.02 mM to 2.0 mM. p-Tyramine was measured by a sensitive and specific radioenzymatic assay. An increase in the perfusate concentration of p-tyrosine resulted in a significant increase in p-tyramine production that was blocked by the addition of NSD-1015, an inhibitor of aromatic-1-amino decarboxylase (AADC). They conclude p-tyrosine is the precursor for the renal production of p-tyramine, renal AADC catalyzes the formation of urinary p-tyramine, synthesized p-tyramine is predominantly excreted in the urine, and p-tyramine synthesis is modulated by the arterial delivery of p-tyrosine to the kidney

  6. Segmental-dependent membrane permeability along the intestine following oral drug administration: Evaluation of a triple single-pass intestinal perfusion (TSPIP) approach in the rat.

    Science.gov (United States)

    Dahan, Arik; West, Brady T; Amidon, Gordon L

    2009-02-15

    In this paper we evaluate a modified approach to the traditional single-pass intestinal perfusion (SPIP) rat model in investigating segmental-dependent permeability along the intestine following oral drug administration. Whereas in the traditional model one single segment of the intestine is perfused, we have simultaneously perfused three individual segments of each rat intestine: proximal jejunum, mid-small intestine and distal ileum, enabling to obtain tripled data from each rat compared to the traditional model. Three drugs, with different permeabilities, were utilized to evaluate the model: metoprolol, propranolol and cimetidine. Data was evaluated in comparison to the traditional method. Metoprolol and propranolol showed similar P(eff) values in the modified model in all segments. Segmental-dependent permeability was obtained for cimetidine, with lower P(eff) in the distal parts. Similar P(eff) values for all drugs were obtained in the traditional method, illustrating that the modified model is as accurate as the traditional, throughout a wide range of permeability characteristics, whether the permeability is constant or segment-dependent along the intestine. Three-fold higher statistical power to detect segmental-dependency was obtained in the modified approach, as each subject serves as his own control. In conclusion, the Triple SPIP model can reduce the number of animals utilized in segmental-dependent permeability research without compromising the quality of the data obtained.

  7. Isolated hepatic perfusion as a treatment for uveal melanoma liver metastases (the SCANDIUM trial)

    DEFF Research Database (Denmark)

    Olofsson, Roger; Ny, Lars; Eilard, Malin Sternby

    2014-01-01

    for patients with liver metastases is between 6 and 12 months, and no treatment has in randomized trials ever been shown to prolong survival. A previous phase II trial using isolated hepatic perfusion (IHP) has suggested a 14-month increase in overall survival compared with a historic control group consisting...... of the longest surviving patients in Sweden during the same time period (26 versus 12 months). METHODS/DESIGN: This is the protocol for a multicenter phase III trial randomizing patients with isolated liver metastases of uveal melanoma to IHP or best alternative care (BAC). Inclusion criteria include liver....... The planned sample size is 78 patients throughout five years. DISCUSSION: Patients with isolated liver metastases of uveal melanoma origin have a short expected survival and no standard treatment option exists. This is the first randomized clinical trial to evaluate IHP as a treatment option with overall...

  8. Kidney in potassium depletion. II. K+ handling by the isolated perfused rat kidney

    International Nuclear Information System (INIS)

    Hayashi, M.; Katz, A.I.

    1987-01-01

    In a companion paper the authors reported a large increment in Na + -K + -ATPase activity and [ 3 H]ouabain binding the inner stripe of outer medullary collecting tubules from K-depleted rats. To test the hypothesis that the increased number of Na + -K + pumps in these animals may be involved in potassium reabsorption they examined the effect of ouabain on K excretion by isolated, perfused kidneys from rats fed a K-free diet for 3 wk. Kidneys from K-depleted rats retain potassium avidly, both the fractional (FE/sub K/) and absolute K excretion being approximately fivefold lower than in control kidneys. Ouabain (5 mM) increased FE/sub K/ in kidneys from each K-depleted rat; similar results were obtained when kidneys were perfused with low and high potassium concentrations. In contrast, ouabain produced a variable effect in control kidneys, that depended on the perfusate potassium concentration. In K-depleted rats amiloride did not significantly alter K excretion and did not block the ouabain-induced kaliuresis, suggesting that the latter is not due to enhanced secretion secondary to increased distal fluid delivery. These results provide evidence for ouabain-sensitive potassium reabsorption in kidneys of chronically K-depleted rats, and suggest an explanation for the increased Na + -K + -ATPase observed in such animals

  9. Prognostic value of myocardial perfusion SPECT versus exercise electrocardiography in patients with ST-segment depression on resting electrocardiography.

    Science.gov (United States)

    De Lorenzo, Andrea; Hachamovitch, Rory; Kang, Xingping; Gransar, Heidi; Sciammarella, Maria G; Hayes, Sean W; Friedman, John D; Cohen, Ishac; Germano, Guido; Berman, Daniel S

    2005-01-01

    The value of exercise-induced ST-segment depression for the prognostic evaluation of patients with 1 mm of ST depression or greater on the resting electrocardiogram is controversial. Patients who underwent exercise myocardial perfusion single photon emission computed tomography (MPS) and had resting ST depression of 1 mm or greater with a nondiagnostic exercise electrocardiographic response (n = 1122) were followed up for 3.4 +/- 2.3 years. Those with paced rhythm, pre-excitation, left bundle branch block, or myocardial revascularization within the first 60 days after MPS were excluded. Additional exercise-induced ST-segment depression was considered significant if > or = 2 mm MPS was scored semiquantitatively by use of a 20-segment model of the left ventricle; the percentage of myocardium involved with stress defects (% myo) was derived by normalizing to the maximal possible score of 80. Hard events were defined as nonfatal myocardial infarction or cardiac death. A Cox analysis was used to determine independent predictors of hard events among clinical, exercise, and nuclear variables. Hard event rates increased as a function of % myo for either patients with exercise-induced ST depression (1.4%/y for normal MPS vs 4.1%/y for % myo >10%, P 10%, P = .0001). Age, diabetes mellitus, shortness of breath as the presenting symptom, and % myo were independent predictors of hard events. Exercise-induced ST depression was predictive of hard events only when it was 3 mm or greater. The presence and extent of perfusion defects, reflected in the % myo, had incremental prognostic value over clinical variables and also over all degrees of exercise-induced ST depression. Although MPS effectively risk-stratifies patients with resting ST depression of 1 mm or greater, the prognostic value of exercise-induced ST depression is limited in these patients, with a small added risk when severe (> or = 3 mm).

  10. [Dynamics of the amino acid composition of the medium during cultivation of isolated organs by the directed perfusion method].

    Science.gov (United States)

    Barashkov, V A; Gitel'zon, I I; Nefedov, V P; Trubachev, I N

    1975-07-01

    The dynamics of the amino acid composition of the medium under conditions of adequate perfusion of the isolated organs of a dog (sternum, kidney and liver) was studied. It was found that after a 6-hour perfusion of the complex of organs the amount in the perfusion medium of such amino acids as histidine, lysine, alanine, considerably increased, whereas the amount of arginine, serine, aspartic acid, threonine with glutamine, isoleucine, proline, leucine and valine decreased as compared with their initial concentration. The dynamics of the amino acid medium composition during a 4-hour perfusion was studied in experiments with the isolated sternum. The concentration of alanine, lysine and histidine increased in the medium. At the same time there was seen a decrease in the concentration of serine, aspartic acid, isoleucine, tyrosine and phenyl-alanine.

  11. [Cytostatic hyperthermic isolated limb perfusion (HILP) in VFN (General Faculty Hospital in Prague)].

    Science.gov (United States)

    Spacek, M; Mitás, P; Lacina, L; Krajsová, I; Hodková, G; Salmay, M; Spunda, R; Brlicová, L; Lindner, J

    2011-01-01

    Hyperthermic isolated limb perfusion (HILP) is a standardized method of treatment in selected patients with in-transient locoregional recurrence/methastasis of melanoma or, some other soft tissue tumors (incl. sarcoma etc.) Authors present history and current status of this treatment modality in General University Hospital in Prague. During one year period (7/2009-6/2010) 10 patients were indicated for this procedure. We performed 13 procedures (3x redo), 11 in lower extremity and 2 in upper extremity. There was no serious complication in this cohort of patiens. Multidisciplinar approach is indicated in melanoma patients care.

  12. The effect of age on outcomes after isolated limb perfusion for advanced extremity malignancies.

    Science.gov (United States)

    Smith, H G; Wilkinson, M J; Smith, M J F; Strauss, D C; Hayes, A J

    2018-06-22

    Isolated limb perfusion (ILP) is a well-established treatment for patients with advanced extremity malignancies unsuitable for limb-conserving surgery. However, little is known about the outcomes of this treatment in elderly patients. We sought to determine the effects of age on the tolerability and efficacy of ILP for advanced extremity malignancy. Patients undergoing ILP at our institution between January 2005 and January 2018 were identified from a prospectively maintained database. Patients were stratified by pathology (melanoma, soft-tissue sarcoma, other) and age (<75 years and ≥75 years). Outcomes of interest were perioperative morbidity and mortality, locoregional toxicities, response rates and oncological outcomes. During the study period, a total of 189 perfusions were attempted. Successful perfusions were performed in 179 patients, giving a technical success rate of 94.7%. No difference in perfusion success rates, severe locoregional toxicity and perioperative morbidity or mortality was noted between those aged <75 years and ≥75 years. The overall response rate in melanoma was 82.4%, and no difference in response rates or oncological outcomes between age groups was noted in these patients. The overall response rate in soft-tissue sarcoma was 63.5%, with no difference in response rates noted between age groups. However, patients aged <75 years with soft-tissue sarcoma had prolonged local recurrence-free survival compared with older patients (13 versus 6 months), possibly due to the prevalence of chemosensitive subtypes in the younger age group. ILP is an effective treatment for advanced extremity malignancies in the elderly, with comparable response rates and toxicities to younger patients. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  13. Intra-arterial high signals on arterial spin labeling perfusion images predict the occluded internal carotid artery segment

    International Nuclear Information System (INIS)

    Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji; Abe, Takashi; Harada, Masafumi; Yamamoto, Nobuaki; Kaji, Ryuji

    2017-01-01

    Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)

  14. Intra-arterial high signals on arterial spin labeling perfusion images predict the occluded internal carotid artery segment

    Energy Technology Data Exchange (ETDEWEB)

    Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji [Tokushima University Graduate School, Department of Neurosurgery, Tokushima (Japan); Abe, Takashi; Harada, Masafumi [Tokushima University Graduate School, Department of Radiology, Tokushima (Japan); Yamamoto, Nobuaki; Kaji, Ryuji [Tokushima University Graduate School, Department of Clinical Neurosciences, Institute of Biomedical Biosciences, Tokushima (Japan)

    2017-06-15

    Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)

  15. Interrelation of ST-segment depression during bicycle ergometry and extent of myocardial ischaemia by myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Muzzarelli, Stefano; Pfisterer, Matthias Emil; Zellweger, Michael Johannes [University Hospital Basel, Cardiology Department, Basel (Switzerland); Mueller-Brand, Jan [University Hospital Basel, Nuclear Medicine Department, Basel (Switzerland)

    2009-11-15

    The aim of this study was to compare ST-segment depression (STD) during bicycle ergometry and extent of myocardial ischaemia assessed by myocardial perfusion SPECT (MPS) in a large patient cohort. Consecutive patients (n = 955) referred for MPS with bicycle ergometry and interpretable stress ECG were evaluated with respect to ECG and MPS findings of ischaemia. The maximal STD was recorded and exercise ECG was considered ischaemic if STD was horizontal or downsloping ({>=}1 mm). MPS was interpreted using a 20-segment model with a scale of 0 to 4. A summed stress (SSS), summed rest (SRS) and summed difference score (SDS = SSS-SRS, e.g. extent of ischaemia) were derived. Ischaemia was defined as an SDS {>=} 2. An exercise-induced STD was present in 215 patients (22%) and myocardial ischaemia on MPS was present in 366 patients (38%). The extent of ST-segment depression and the number of ECG leads with significant STD were each strongly and significantly associated with increasing severity of ischaemia and the number of coronary territories involved (p < 0.01 for all correlations). These data demonstrate a strong correlation between the extent of STD, number of ischaemic leads and severity of myocardial ischaemia as assessed by MPS during bicycle ergometry. (orig.)

  16. Interrelation of ST-segment depression during bicycle ergometry and extent of myocardial ischaemia by myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Muzzarelli, Stefano; Pfisterer, Matthias Emil; Zellweger, Michael Johannes; Mueller-Brand, Jan

    2009-01-01

    The aim of this study was to compare ST-segment depression (STD) during bicycle ergometry and extent of myocardial ischaemia assessed by myocardial perfusion SPECT (MPS) in a large patient cohort. Consecutive patients (n = 955) referred for MPS with bicycle ergometry and interpretable stress ECG were evaluated with respect to ECG and MPS findings of ischaemia. The maximal STD was recorded and exercise ECG was considered ischaemic if STD was horizontal or downsloping (≥1 mm). MPS was interpreted using a 20-segment model with a scale of 0 to 4. A summed stress (SSS), summed rest (SRS) and summed difference score (SDS = SSS-SRS, e.g. extent of ischaemia) were derived. Ischaemia was defined as an SDS ≥ 2. An exercise-induced STD was present in 215 patients (22%) and myocardial ischaemia on MPS was present in 366 patients (38%). The extent of ST-segment depression and the number of ECG leads with significant STD were each strongly and significantly associated with increasing severity of ischaemia and the number of coronary territories involved (p < 0.01 for all correlations). These data demonstrate a strong correlation between the extent of STD, number of ischaemic leads and severity of myocardial ischaemia as assessed by MPS during bicycle ergometry. (orig.)

  17. A novel clinically relevant segmentation method and corresponding maximal ischemia score to risk-stratify patients undergoing myocardial perfusion scintigraphy.

    Science.gov (United States)

    Nudi, Francesco; Pinto, Annamaria; Procaccini, Enrica; Neri, Giandomenico; Vetere, Maurizio; Tomai, Fabrizio; Gaspardone, Achille; Biondi-Zoccai, Giuseppe; Schillaci, Orazio

    2014-08-01

    Myocardial perfusion scintigraphy (MPS) represents a key prognostic tool, but its predictive yield is far from perfect. We developed a novel clinically relevant segmentation method and a corresponding maximal ischemia score (MIS) in order to risk-stratify patients undergoing MPS. Patients referred for MPS were identified, excluding those with evidence of myocardial necrosis or prior revascularization. A seven-region segmentation approach was adopted for left ventricular myocardium, with a corresponding MIS distinguishing five groups (no, minimal, mild, moderate, or severe ischemia). The association between MIS and clinical events was assessed at 1 year and at long-term follow-up. A total of 8,714 patients were included, with a clinical follow-up of 31 ± 20 months. Unadjusted analyses showed that subjects with a higher MIS were significantly different for several baseline and test data, being older, having lower ejection fraction, and achieving lower workloads (P < .05 for all). Adverse outcomes were also more frequent in patients with higher levels of ischemia, including cardiac death, myocardial infarction (MI), and their composites (P < .05 for all). Differences in adverse events remained significant even after extensive multivariable adjustment (hazard ratio for each MIS increment = 1.57 [1.29-1.90], P < .001 for cardiac death; 1.19 [1.04-1.36], P = .013 for MI; 1.23 [1.09-1.39], P = .001 for cardiac death/MI). Our novel segmentation method and corresponding MIS efficiently yield satisfactory prognostic information.

  18. Propofol attenuates oxidant-induced acute lung injury in an isolated perfused rabbit-lung model.

    Science.gov (United States)

    Yumoto, Masato; Nishida, Osamu; Nakamura, Fujio; Katsuya, Hirotada

    2005-01-01

    Reactive oxygen species have been strongly implicated in the pathogenesis of acute lung injury (ALI). Some animal studies suggest that free radical scavengers inhibit the onset of oxidant-induced ALI. Propofol (2,6-diisopropylphenol) is chemically similar to phenol-based free radical scavengers such as the endogenous antioxidant vitamin E. Both in vivo and in vitro studies have suggested that propofol has antioxidant potential. We hypothesized that propofol may attenuate ALI by acting as a free-radical scavenger. We investigated the effects of propofol on oxidant-induced ALI induced by purine and xanthine oxidase (XO), in isolated perfused rabbit lung, in two series of experiments. In series 1, we examined the relationship between the severity of ALI and the presence of hydrogen peroxide (H2O2). In series 2, we evaluated the effects of propofol on attenuating ALI and the dose dependence of these effects. The lungs were perfused for 90 min, and we evaluated the effects on the severity of ALI by monitoring the pulmonary capillary filtration coefficient (Kfc), pulmonary arterial pressure (Ppa), and the pulmonary capillary hydrostatic pressure (Ppc). In series 1, treatment with catalase (an H2O2 scavenger) prior to the addition of purine and XO resulted in complete prevention of ALI, suggesting that H2O2 may be involved closely in the pathogenesis of ALI. In series 2, pretreatment with propofol at concentrations in excess of 0.5 mM significantly inhibited the increases in the Kfc values, and that in excess of 0.75 mM significantly inhibited the increase in the Ppa values. Propofol attenuates oxidant-induced ALI in an isolated perfused rabbit lung model, probably due to its antioxidant action.

  19. Active Oxygen Metabolites and Thromboxane in Phorbol Myristate Acetate Toxicity to the Isolated, Perfused Rat Lung.

    Science.gov (United States)

    Carpenter, Laurie Jean

    When administered intravenously or intratracheally to rats, rabbits and sheep, phorbol myristate acetate (PMA) produces changes in lung morphology and function are similar to those seen in humans with the adult respiratory distress syndrome (ARDS). Therefore, it is thought that information about the mechanism of ARDS development can be gained from experiments using PMA-treated animals. Currently, the mechanisms by which PMA causes pneumotoxicity are unknown. Results from other studies in rabbits and in isolated, perfused rabbit lungs suggest that PMA-induced lung injury is mediated by active oxygen species from neutrophils (PMN), whereas studies in sheep and rats suggest that PMN are not required for the toxic response. The role of PMN, active oxygen metabolites and thromboxane (TxA_2) in PMA-induced injury to isolated, perfused rat lungs (IPLs) was examined in this thesis. To determine whether PMN were required for PMA to produce toxicity to the IPL, lungs were perfused for 30 min with buffer containing various concentrations of PMA (in the presence or absence of PMN). When concentrations >=q57 ng/ml were added to medium devoid of added PMN, perfusion pressure and lung weight increased. When a concentration of PMA (14-28 ng/ml) that did not by itself cause lungs to accumulate fluid was added to the perfusion medium containing PMN (1 x 10 ^8), perfusion pressure increased, and lungs accumulated fluid. These results indicate that high concentrations of PMA produce lung injury which is independent of PMN, whereas injury induced by lower concentrations is PMN-dependent. To examine whether active oxygen species were involved in mediating lung injury induced by PMA and PMN, lungs were coperfused with the oxygen radical scavengers SOD and/or catalase. Coperfusion with either or both of these enzymes totally protected lungs against injury caused by PMN and PMA. These results suggest that active oxygen species (the hydroxyl radical in particular), mediate lung injury in

  20. Double-Balloon Catheter for Isolated Liver Perfusion: An Experimental Study

    International Nuclear Information System (INIS)

    Cwikiel, Wojciech; Bergqvist, Lennart; Harnek, Jan

    2001-01-01

    Purpose: Further development of a previously described interventional method for isolated liver perfusion (ILP) with a new double-lumen balloon catheter, and evaluation of the side-effects of such isolation.Methods: In six pigs a double-balloon occlusion catheter was placed via the transjugular approach with its tip in the portal vein. One of the balloons was positioned in the inferior vena cava (IVC), cranial to the origin of the hepatic veins and the other balloon in the portal vein. By the transfemoral approach, a single-balloon occlusion catheter was placed in the IVC caudal to the origin of the hepatic veins. A third catheter was placed by the transfemoral route with the occlusion balloon in the proper hepatic artery. After inflation of all balloons 99 Tc m -labelled human serum albumin was recirculated through the liver. The isolation was evaluated by repeated measurement of radioactivity levels in peripheral blood. Laboratory tests of liver and pancreas function, and hemoglobin, were taken before, at the end of, and 3 days after the procedure. Blood gases were tested at the beginning and end of the procedure.Results: One pig died during the procedure due to technical failure and was excluded from the study. In the other pigs leakage from the isolated liver to the systemic circulation increased slowly, up to 9.7% (mean) during 30 min of recirculation of the perfusate through the liver. Laboratory tests were normal in all pigs except insignificant acidosis directly after the procedure and the slight elevation of s-ALAT after 3 days.Conclusions: Only minor leakage from the liver to the systemic circulation was noted during ILP performed with a new, double-balloon catheter. There were no serious side effects

  1. Comparison of two different segmentation methods on planar lung perfusion scan with reference to quantitative value on SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Min Seok; Kang, Yeon Koo; Ha, Seung Gyun [Dept. of Nuclear Medicine, Seoul National University Hospital, Seoul (Korea, Republic of); and others

    2017-06-15

    Until now, there was no single standardized regional segmentation method of planar lung perfusion scan. We compared planar scan based two segmentation methods, which are frequently used in the Society of Nuclear Medicine, with reference to the lung perfusion single photon emission computed tomography (SPECT)/computed tomography (CT) derived values in lung cancer patients. Fifty-five lung cancer patients (male:female, 37:18; age, 67.8 ± 10.7 years) were evaluated. The patients underwent planar scan and SPECT/CT after injection of technetium-99 m macroaggregated albumin (Tc-99 m-MAA). The % uptake and predicted postoperative percentage forced expiratory volume in 1 s (ppoFEV1%) derived from both posterior oblique (PO) and anterior posterior (AP) methods were compared with SPECT/CT derived parameters. Concordance analysis, paired comparison, reproducibility analysis and spearman correlation analysis were conducted. The % uptake derived from PO method showed higher concordance with SPECT/CT derived % uptake in every lobe compared to AP method. Both methods showed significantly different lobar distribution of % uptake compared to SPECT/CT. For the target region, ppoFEV1% measured from PO method showed higher concordance with SPECT/CT, but lower reproducibility compared to AP method. Preliminary data revealed that every method significantly correlated with actual postoperative FEV1%, with SPECT/CT showing the best correlation. The PO method derived values showed better concordance with SPECT/CT compared to the AP method. Both PO and AP methods showed significantly different lobar distribution compared to SPECT/CT. In clinical practice such difference according to different methods and lobes should be considered for more accurate postoperative lung function prediction.

  2. Inhibition of mirtazapine metabolism by Ecstasy (MDMA) in isolated perfused rat liver model.

    Science.gov (United States)

    Jamshidfar, Sanaz; Ardakani, Yalda H; Lavasani, Hoda; Rouini, Mohammadreza

    2017-06-28

    Nowadays MDMA (3,4-methylendioxymethamphetamine), known as ecstasy, is widely abused among the youth because of euphoria induction in acute exposure. However, abusers are predisposed to depression in chronic consumption of this illicit compound. Mirtazapine (MRZ), an antidepressant agent, may be prescribed in MDMA-induced depression. MRZ is extensively metabolized in liver by CYP450 isoenzymes. 8-hydroxymirtazapine (8-OH) is mainly produced by CYP2D6. N-desmethylmirtazapine (NDES) is generated by CYP3A4. MDMA is also metabolized by the mentioned isoenzymes and demonstrates mechanism-based inhibition (MBI) in association with CYP2D6. Several studies revealed that MDMA showed inhibitory effects on CYP3A4. In the present study, our aim was to evaluate the impact of MDMA on the metabolism of MRZ in liver. Therefore, isolated perfused rat liver model was applied as our model of choice in this assessment. The subjects of the study were categorized into two experimental groups. Rats in the control group received MRZ-containing Krebs-Henselit buffer (1 μg/ml). Rats in the treatment group received aqueous solution of 1 mg/ml MDMA (3 mg/kg) intraperitoneally 1 hour before receiving MRZ. Perfusate samples were analyzed by HPLC. Analyses of perfusate samples showed 80% increase in the parent drug concentrations and 50% decrease in the concentrations of both metabolites in our treatment group compared to the control group. In the treatment group compared to the control group, AUC (0-120) of the parent drug demonstrated 50% increase and AUC (0-120) of 8-OH and NDES showed 70% and 60% decrease, respectively. Observed decrease in metabolic ratios were 83% and 79% for 8-OH and NDES in treatment group compared to control group, respectively. Hepatic clearance (CL h ) and intrinsic clearance (Cl int ) showed 20% and 60% decrease in treatment group compared to control group. All findings prove the inhibitory effects of ecstasy on both CYP2D6 and CYP3A4 hepatic isoenzymes. In

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

    Directory of Open Access Journals (Sweden)

    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

  4. 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

  5. Evaluating the morphological changes of intracranial arteries and whole-brain perfusion in undetermined isolated vertigo.

    Science.gov (United States)

    Li, Wenxian; Feng, Youzhen; Lu, Weibiao; Xie, Xie; Xiong, Zhilin; Jing, Zhen; Cai, Xiangran; Huang, Li'an

    2016-11-15

    To determine the morphological changes of intracranial arteries and whole-brain perfusion in undetermined isolated vertigo (UIV) patients using 320-detector row computed tomography (CT). A total of 150 patients who underwent CT angiography (CTA) and CT perfusion (CTP) imaging were divided into UIV group and benign paroxysmal positional vertigo (BPPV) group. Sixty individuals with sex- and age-matched without vertigo and cerebral diseases served as the control. The morphological changes of intracranial arteries, perfusion parameters and vascular risk factors (VRFs) were analyzed, calculated and compared. In UIV patients, hypertension (HT), hyperlipidemia and number of VRFs≥3 occurred more commonly (P<0.0125, respectively). The incidence of vertebral artery dominance (VAD), vertebral artery stenosis (VAS) and basilar artery curvature (BAC) were significantly higher (P<0.0125, respectively). HT was an independent risk predictor of non-VAD (OR: 5.411, 95%CI: 1.401; 20.900, P=0.014). HT and VAD associated with BAC served as risk predictors (OR: 4.081, 95%CI: 1.056;15.775, P=0.041 and OR: 6.284, 95%CI: 1.848; 21.365, P=0.003, respectively). The absolute difference in relative values of CTP parameters from cerebellum and brainstem were significantly different (P<0.05), and hypoperfusion was found in the territories of the non-VAD side and the BAC cohort (P<0.05, respectively). On the basis of multiple VRFs, morphological changes of vertebrobasilar artery (VBA) and the unilateral hypoperfusion of the cerebellum and brainstem, that acts as a herald for IV occurrence, which should be paid cautious attention to UIV patients. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Transport of salicylate in proximal tubule (S2 segment) isolated from rabbit kidney

    International Nuclear Information System (INIS)

    Schild, L.; Roch-Ramel, F.

    1988-01-01

    The secretory and the reabsorptive transport of salicylate was studied in the isolated and perfused rabbit proximal tubule (S 2 segment). Salicylate secretion (J sal b→l ) fulfilled the criteria for a carrier-mediated transport system: J sal b→l was saturable, was reversibly inhibited by probenecid, and occurred against a concentration gradient. The K m and V max for this secretory transport were 80 μM and 3,200 fmol·min -1 ·mm -1 , respectively. At luminal pH of 7.4 and 6.6, salicylate reabsorption (J sal l→b ) was low. J sal l→b was stimulated by increasing the bath Pco 2 or by removing basolateral HCO 3 - ; J sal l→b was inhibited by ethoxyzolamide and by SITS in the bath. The results indicate that salicylate reabsorption depends on H + secretion, consistent with reabsorption by simple nonionic diffusion. When salicylate was present in the lumen only, J sal l→b increased after inhibition of the secretory transport by adding ouabain or probenecid in the bath or by lowering the bath temperature. These results are compatible with luminal recycling of salicylate, and suggest the presence of a mediated secretory transporter located at the luminal membrane

  7. Perfusion-weighted magnetic resonance imaging detects recurrent isolated vertigo caused by cerebral hypoperfusion.

    Science.gov (United States)

    Xu, Xiaowei; Jiang, Li; Luo, Man; Li, Jiaoxing; Li, Weidong; Sheng, Wenli

    2015-06-01

    The etiology of isolated vertigo has been a substantial diagnostic challenge for both neurologists and otolaryngologists. This study was designed to detect recurrent isolated vertigo due to cerebral hypoperfusion using perfusion-weighted magnetic resonance imaging (PWI). We recruited isolated vertigo patients whose clinical condition was suspected to be caused by hypodynamics of the brain; these individuals formed the case group. We generated two additional groups: a negative group composed of vertigo patients whose symptoms were caused by problems associated with the ear and a healthy control group. Each subject underwent PWI, and seven regions of interest (ROIs) were chosen. The relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT) were obtained from each ROI. We further calculated the absolute difference of relative parameter values between two mirrored ROIs. The significant difference in the relative MTT from the mirrored cerebellar ROI (|rMTTleft-right|) of the case group was larger than those from the negative and healthy control groups (p = 0.026 and p = 0.038, respectively). Signal differences in |rrCBVleft-right| and |rrCBFleft-right| were not found among the three groups. In summary, disequilibrium in the rMTT of the bilateral cerebellum in the case group implied that hypoperfusion of the posterior circulation could trigger recurrent isolated vertigo and could be shown efficiently using PWI.

  8. Luminal and basolateral uptake of insulin in isolated perfused, proximal tubules

    International Nuclear Information System (INIS)

    Nielsen, S.; Nielsen, J.T.; Christensen, E.I.

    1987-01-01

    The present study was performed to quantitate compare the luminal and the peritubular uptake of 125 I-insulin in isolated, perfused, proximal tubules from rabbit kidneys. 125 I-insulin was added in physiological concentrations to either the perfusate or the bath fluid for 30 min. The luminal uptake in 30 min averaged 0.76 pg/mm at physiological concentrations and 18.0 pg/mm at high insulin concentrations. About 15-41% of the absorbed insulin was digested and 125 I-insulin at physiological and high concentrations in the bath was 0.136 and 0.318 pg, respectively. The data indicates that insulin is bound/absorbed at the basolateral membranes both by a saturable specific mechanism and a nonspecific, nonsaturable mechanism. The basolateral absorption constituted 15.2 and 1.8% of the total tubular extraction of insulin at physiological and high insulin concentrations, respectively. Electron microscope autoradiography showed that, after luminal as well as basolateral endocytosis, insulin was exclusively accumulated in endocytic vacuoles and lysosomes

  9. Radiation-induced increase in the release of amino acids by isolated, perfused skeletal muscle

    International Nuclear Information System (INIS)

    Schwenen, M.

    1989-01-01

    Local exposure of the hindquarter of the rat to 15Gy of gamma-radiation resulted, 4-6h after irradiation, in increased release of amino acids by the isolated, perfused hindquarter preparation, 70% of which is skeletal muscle. This increase in release involves not only alanine and glutamine, but also those amino acids not metabolized by muscle and, therefore, released in proportion to their occurrence in muscle proteins. Because metabolic parameters and content of energy-rich phosphate compounds in muscle remain unchanged, it is unlikely that general cellular damage is the underlying cause of the radiation-induced increase in amino acid release. The findings strongly favour the hypothesis that increased availability of amino acids results from enhanced protein break-down in skeletal muscle which has its onset shortly after irradiation. This radiation-induced disturbance in protein metabolism might be one of the pathogenetic factors in the aetiology of radiation myopathy. (author)

  10. Perfusion of the isolated rat brain with (/sup 14/C)-. delta. /sup 1/-tetrahydrocannabinol

    Energy Technology Data Exchange (ETDEWEB)

    Martin, B; Agurell, S [Dept. of Pharmacognosy, Faculty of Pharmacy, BMC, Uppsala (Sweden); Krieglstein, J; Rieger, H

    1977-12-01

    There is controversy over whether ..delta../sup 1/-tetrahydrocannabinol (..delta../sup 1/-THC) or its metabolites is responsible for the behavioural and cardiovascular effects of cannabis. It has been shown that, even in the absence of metabolism, ..delta../sup 1/-THC was capable of altering the EEG of isolated perfused rat brain, and must therefore contribute to the psychoactivity of cannabis. TLC studies showed no evidence for brain metabolism of (/sup 14/C)-..delta../sup 1/-THC, and in particular the 7-hydroxylated metabolite (7-OH-..delta../sup 1/-THC) could not be detected. A disproportionate amount of CNS activity in the rat cannot therefore be attributed to 7-OH-..delta../sup 1/-THC on the basis that it is formed at or near its locus of action.

  11. Perfusion of the isolated rat brain with [14C]-Δ1-tetrahydrocannabinol

    International Nuclear Information System (INIS)

    Martin, B.; Agurell, S.; Krieglstein, J.; Rieger, H.

    1977-01-01

    There is controversy over whether Δ 1 -tetrahydrocannabinol (Δ 1 -THC) or its metabolites is responsible for the behavioural and cardiovascular effects of cannabis. It has been shown that, even in the absence of metabolism, Δ 1 -THC was capable of altering the EEG of isolated perfused rat brain, and must therefore contribute to the psychoactivity of cannabis. TLC studies showed no evidence for brain metabolism of [ 14 C]-Δ 1 -THC, and in particular the 7-hydroxylated metabolite (7-OH-Δ 1 -THC) could not be detected. A disproportionate amount of CNS activity in the rat cannot therefore be attributed to 7-OH-Δ 1 -THC on the basis that it is formed at or near its locus of action. (U.K.)

  12. 31P nuclear magnetic resonance surface coil study of ischemic preconditioned isolated perfused rat heart

    International Nuclear Information System (INIS)

    Yan Yongbin; Luo Xuechun; Zhang Riqing; Wang Xiaoyin; Zuo Lin; Liu Wei

    2000-01-01

    ischemic preconditioning (IPC) will protect the heart from the damage caused by a subsequent long ischemia period. 31 P spectra of isolated perfused rat heart measured by the nuclear magnetic resonance (NMR) surface coil technique can be used to continually, dynamically and noninvasively obtain metabolism information. This paper explores the IPC mechanisms by NMR. This study shows that IPC has no effect on enhancing the ATP and PCr levels during reperfusion but makes significantly slows and smooths the changes of intracellular pH and ATP during ischemia periods. The ATP and PCr recovery rate of the IPC group after ischemia is significantly higher than that of the control group. In conclusion, the above results support that IPC can protect the rat heart by reducing damage during the ischemia period

  13. TNFa-based isolated limb perfusion in the rat : development of a model and analysis of efficacy determining factors

    NARCIS (Netherlands)

    E.R. Manusama (Eric)

    1998-01-01

    textabstractIsolated limb perfusion (lLP) with high dose TNFa in combination with IFNr and melphalan in patients with melanoma in transit metastases confined to the limb has recently been reported to result in much higher complete tumor response rates than after the standard therapy of ILP with

  14. Isolated lung perfusion with gemcitabine for the treatment of pulmonary metastases : Experimental study in a rat model

    NARCIS (Netherlands)

    Putte, B.P. van

    2003-01-01

    Isolated lung perfusion is an experimental surgical technique for the treatment of pulmonary metastases in order to improve the current 5-year survival of approximately 40 % after surgical resection of manually palpable metastases. Several drugs have been tested in animals models and five phase I

  15. The impact of short chain fatty acids on GLP-1 and PYY secretion from the isolated perfused rat colon

    DEFF Research Database (Denmark)

    Christiansen, Charlotte Bayer; Gabe, Maria Buur Nordskov; Svendsen, Berit

    2018-01-01

    chain fatty acids (SCFAs) produced by local bacterial fermentation are suggested to activate the colonic free fatty acid receptors FFAR2 (GPR43) and FFAR3 (GPR41), stimulating the colonic L-cells. We used the isolated perfused rat colon as a model of colonic endocrine secretion and studied the effects...

  16. The influence of Poly-Vinyl-Chloride tubing on the isolated perfused rat´s heart.

    NARCIS (Netherlands)

    Meijler, F.L.; Durrer, D.

    1950-01-01

    There are types of poly-vinyl-chloride tubing sold and used for medical and biological purposes which deteriorate heart action in a few minutes. A simple method for testing P.V.C. tubing can be found in the isolated rat's he art perfused according to Langendorff.

  17. HYPERTHERMIC ISOLATED REGIONAL PERFUSION WITH CISPLATIN IN THE LOCAL TREATMENT OF SPONTANEOUS CANINE OSTEOSARCOMA - ASSESSMENT OF SHORT-TERM EFFECTS

    NARCIS (Netherlands)

    VANGINKEL, RJ; HOEKSTRA, HJ; MEUTSTEGE, FJ; OOSTERHUIS, JW; UGES, DRA; KOOPS, HS

    To increase the effect of cisplatin on locoregional osteosarcoma, the short-term effect of hyperthermic isolated regional perfusion (HIRP) with cisplatin (30 mg/L extremity volume) was studied in 28 dogs with spontaneous osteogenic sarcoma, using clinical, radiological, and histological parameters.

  18. Anionic and cationic drug secretion in the isolated perfused rat kidney after neonatal surgical induction of ureteric obstruction.

    NARCIS (Netherlands)

    Gier, R.P.E. de; Feitz, W.F.J.; Masereeuw, R.; Wouterse, A.C.; Smits, D.; Russel, F.G.M.

    2003-01-01

    OBJECTIVE: To study the pathophysiological changes of renal tubular drug transport mechanisms in congenital renal obstruction, by developing a model for perfusing the isolated kidney (IPK) after neonatal surgical induction of partial ureteric obstruction in Hanover Wistar rats. MATERIAL AND METHODS:

  19. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    Energy Technology Data Exchange (ETDEWEB)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K. [Department of Radiological Sciences, Guy' s, King' s and St. Thomas' School of Medicine, London (United Kingdom)

    1999-10-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  20. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    International Nuclear Information System (INIS)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K.

    1999-01-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  1. In vitro culture of functionally active buffalo hepatocytes isolated by using a simplified manual perfusion method.

    Directory of Open Access Journals (Sweden)

    Santanu Panda

    Full Text Available In farm animals, there is no suitable cell line available to understand liver-specific functions. This has limited our understanding of liver function and metabolism in farm animals. Culturing and maintenance of functionally active hepatocytes is difficult, since they survive no more than few days. Establishing primary culture of hepatocytes can help in studying cellular metabolism, drug toxicity, hepatocyte specific gene function and regulation. Here we provide a simple in vitro method for isolation and short-term culture of functionally active buffalo hepatocytes.Buffalo hepatocytes were isolated from caudate lobes by using manual enzymatic perfusion and mechanical disruption of liver tissue. Hepatocyte yield was (5.3 ± 0.66×107 cells per gram of liver tissue with a viability of 82.3 ± 3.5%. Freshly isolated hepatocytes were spherical with well contrasted border. After 24 hours of seeding onto fibroblast feeder layer and different extracellular matrices like dry collagen, matrigel and sandwich collagen coated plates, hepatocytes formed confluent monolayer with frequent clusters. Cultured hepatocytes exhibited typical cuboidal and polygonal shape with restored cellular polarity. Cells expressed hepatocyte-specific marker genes or proteins like albumin, hepatocyte nuclear factor 4α, glucose-6-phosphatase, tyrosine aminotransferase, cytochromes, cytokeratin and α1-antitrypsin. Hepatocytes could be immunostained with anti-cytokeratins, anti-albumin and anti α1-antitrypsin antibodies. Abundant lipid droplets were detected in the cytosol of hepatocytes using oil red stain. In vitro cultured hepatocytes could be grown for five days and maintained for up to nine days on buffalo skin fibroblast feeder layer. Cultured hepatocytes were viable for functional studies.We developed a convenient and cost effective technique for hepatocytes isolation for short-term culture that exhibited morphological and functional characteristics of active hepatocytes

  2. Synergistic antitumor activity of histamine plus melphalan in isolated limb perfusion: preclinical studies.

    Science.gov (United States)

    Brunstein, Flavia; Hoving, Saske; Seynhaeve, Ann L B; van Tiel, Sandra T; Guetens, Gunther; de Bruijn, Ernst A; Eggermont, Alexander M M; ten Hagen, Timo L M

    2004-11-03

    We have previously shown how tumor response of isolated limb perfusion (ILP) with melphalan was improved when tumor necrosis factor alpha (TNF-alpha) was added. Taking into account that other vasoactive drugs could also improve tumor response to ILP, we evaluated histamine (Hi) as an alternative to TNF-alpha. We used a rat ILP model to assess the combined effects of Hi and melphalan (n = 6) on tumor regression, melphalan uptake (n = 6), and tissue histology (n = 2) compared with Hi or melphalan alone. We also evaluated the growth of BN-175 tumor cells as well as apoptosis, necrosis, cell morphology, and paracellular permeability of human umbilical vein endothelial cells (HUVECs) after Hi treatment alone and in combination with melphalan. The antitumor effect of the combination of Hi and melphalan in vivo was synergistic, and Hi-dependent reduction in tumor volume was blocked by H1 and H2 receptor inhibitors. Tumor regression was observed in 66% of the animals treated with Hi and melphalan, compared with 17% after treatment with Hi or melphalan alone. Tumor melphalan uptake increased and vascular integrity in the surrounding tissue was reduced after ILP treatment with Hi and melphalan compared with melphalan alone. In vitro results paralleled in vivo results. BN-175 tumor cells were more sensitive to the cytotoxicity of combined treatment than HUVECs, and Hi treatment increased the permeability of HUVECs. Hi in combination with melphalan in ILP improved response to that of melphalan alone through direct and indirect mechanisms. These results warrant further evaluation in the clinical ILP setting and, importantly, in organ perfusion.

  3. Interpretative intra- and interobserver reproducibility of Stress/Rest 99m Tc-steamboat's myocardial perfusion SPECT using semi quantitative 20-segment model

    International Nuclear Information System (INIS)

    Fazeli, M.; Firoozi, F.

    2002-01-01

    It well established that myocardial perfusion SPECT with 201 T L or 99 mTc-se sta mi bi play an important role diagnosis and risk assessment in patients with known or suspected coronary artery disease. Both quantitative and qualitative methods are available for interpretation of images. The use of a semi quantitative scoring system in which each of 20 segments is scored according to a five-point scheme provides an approach to interpretation that is more systematic and reproducible than simple qualitative evaluation. Only a limited number of studies have dealt with the interpretive observer reproducibility of 99 mTc-steamboat's myocardial perfusion imaging. The aim of this study was to assess the intra-and inter observer variability of semi quantitative SPECT performed with this technique. Among 789 patients that underwent myocardial perfusion SPECT during last year 80 patients finally need to coronary angiography as gold standard. In this group of patients a semi quantitative visual interpretation was carried out using short axis and vertical long-axis myocardial tomograms and a 20-segments model. These segments we reassigned on six evenly spaced regions in the apical, mid-ventricular, and basal short-axis view and two apical segments on the mid-ventricular long-axis slice. Uptake in each segment was graded on a 5-point scale (0=normal, 1=equivocal, 2=moderate, 3=severe, 4=absence of uptake). The steamboat's images was interpreted separately w ice by two observers without knowledge of each other's findings or results of angiography. A SPECT study was judged abnormal if there were two or more segments with a stress score equal or more than 2. We con eluded that semi-quantitative visual analysis is a simple and reproducible method of interpretation

  4. The Hepatoprotective Effects of Corn Silk against Dose-induced Injury of Ecstasy (MDMA Using Isolated Rat Liver Perfusion System

    Directory of Open Access Journals (Sweden)

    Mohammad Karami

    2016-07-01

    Full Text Available Background: Corn silk (CS is widely used in Iranian traditional medicine. The aim of this study was to investigate hepatoprotective activity of CS by Isolated Rat Liver Perfusion System (IRLP. Methods: Hydro-alcoholic extract of corn silk (10, 20, 40, and 100 mg kg-1 was evaluated for its hepatoprotective activity by IRLP. Phenol and flavonoid contents of the extract were determined as gallic acid and quercetin equivalents from a calibration curve, respectively. IRLP system is ideal for studying biochemical alterations of chemicals with minimum neuro-hormonal effects. In this study, the liver was perfused with Kerbs-Henseleit buffer, containing different concentration of hydro-alcoholic extract of corn silk (10, 20, 40, 50,100mg/kg, added to the buffer, and perfused for 2 hours. During the perfusion, many factors, including amino-transferees activities and the level of GSH, were assessed as indicators of liver viability. Consequently, sections of liver tissues were examined for any histopathological changes. Results: Histopathological changes in liver tissues were related to hydro-alcoholic extract of corn silk concentrations in a dose-dependent manner. Also, 50 and 100mg/kg doses caused significant (P<0.05 histopathological changes. Level of GSH in samples perfused with hydro-alcoholic extract increased compared to the control group. Conclusion: Hepatoprotective effect of CS is due to decreased lipid peroxidation, although other mechanisms might also be involved.

  5. Regional MRI Perfusion Measures Predict Motor/Executive Function in Patients with Clinically Isolated Syndrome

    Directory of Open Access Journals (Sweden)

    Efrosini Z. Papadaki

    2014-01-01

    Full Text Available Background. Patients with clinically isolated syndrome (CIS demonstrate brain hemodynamic changes and also suffer from difficulties in processing speed, memory, and executive functions. Objective. To explore whether brain hemodynamic disturbances in CIS patients correlate with executive functions. Methods. Thirty CIS patients and forty-three healthy subjects, matched for age, gender, education level, and FSIQ, were administered tests of visuomotor learning and set shifting ability. Cerebral blood volume (CBV, cerebral blood flow (CBF, and mean transit time (MTT values were estimated in normal-appearing white matter (NAWM and normal-appearing deep gray Matter (NADGM structures, using a perfusion MRI technique. Results. CIS patients showed significantly elevated reaction time (RT on both tasks, while their CBV and MTT values were globally increased, probably due to inflammatory vasodilation. Significantly, positive correlation coefficients were found between error rates on the inhibition condition of the visuomotor learning task and CBV values in occipital, periventricular NAWM and both thalami. On the set shifting condition of the respective task significant, positive associations were found between error rates and CBV values in the semioval center and periventricular NAWM bilaterally. Conclusion. Impaired executive function in CIS patients correlated positively with elevated regional CBV values thought to reflect inflammatory processes.

  6. Effect of ADH on rubidium transport in isolated perfused rat cortical collecting tubules

    International Nuclear Information System (INIS)

    Schafer, J.A.; Troutman, S.L.

    1986-01-01

    Unidirectional fluxes of 86Rb+ were measured as an indicator of potassium transport in isolated rat cortical collecting tubules perfused and bathed at 38 degrees C with isotonic solutions in which Rb+ replaced K+. Under control conditions the lumen-to-bath flux (Jl----b) was significantly less than the bath-to-lumen flux (Jb----l), indicating net Rb+ secretion. Net secretion increased approximately 180% after addition of 100 microU/ml of arginine vasopressin (ADH) to the bathing solution, due to a rapid and reversible increase in Jb----l from 4.6 +/- 0.8 to 9.0 +/- 1.9 pmol X min-1 X mm-1 with no significant change in Jl----b. The ADH effect was completely inhibited by 2 mM luminal Ba2+. The average transepithelial voltage (Ve) was not significantly different from zero in the control period but became lumen negative (-5 to -10 mV) after ADH. With 10(-5) M amiloride in the lumen Ve was lumen positive (+2 to +4 mV) and was unaltered by ADH or Ba2+, yet ADH produced a significant but attentuated increase in Jb----l with no change in Jl----b. The results indicate that ADH augments net K+ secretion either by an increase in the Ba2+-sensitive conductance of the apical membrane or by an increase in the electrochemical potential driving force for net Rb+ secretion through this pathway

  7. Effect of adenosine1-receptor blockade on renin release from rabbit isolated perfused juxtaglomerular apparatus

    DEFF Research Database (Denmark)

    Weihprecht, H; Lorenz, J N; Schnermann, J

    1990-01-01

    Adenosine has been proposed to act within the juxtaglomerular apparatus (JGA) as a mediator of the inhibition of renin secretion produced by a high NaCl concentration at the macula densa. To test this hypothesis, we studied the effects of the adenosine1 (A1)-receptor blocker 8-cyclopentyl-1......,3-dipropylxanthine (CPX) on renin release from single isolated rabbit JGAs with macula densa perfused. The A1-receptor agonist, N6-cyclohexyladenosine (CHA), applied in the bathing solution at 10(-7) M, was found to inhibit renin secretion, an effect that was completely blocked by adding CPX (10(-5) M) to the bath....... Applied to the lumen, 10(-5) M CPX produced a modest stimulation of renin secretion rates suppressed by a high NaCl concentration at the macula densa (P less than 0.05). The effect of changing luminal NaCl concentration on renin secretion rate was examined in the presence of CPX (10(-7) and 10(-5) M...

  8. Biliary excretion of ouabain in isolated perfused rat liver after treatment with microsomal enzyme inducers

    International Nuclear Information System (INIS)

    Nevasaari, K.; Alakare, B.; Kaerki, N.T.

    1976-01-01

    The effect of pretreatment with spironolactone, phenobarbital and 3,4-benzpyrene on biliary excretion of ouabain was studied in isolated perfused rat liver system after a single dose of 3 H-ouabain. Spironolactone pretreatment (100 mg/kg intraperitoneally for 4 days) changed the time course of the excretion, thus accelerating the transport of ouabain into the bile. Phenobarbital pretreatment (75 mg/kg intraperitoneally for 4 days) enhanced bile flow and increased biliary excretion of ouabain only after 15 min. At longer time periods the increase in bile flow diluted the bile level of ouabain there being no difference in the amounts excreted into the bile between the treated and untreated groups. 3,4-benzpyrene pretreatment (20 mg/kg intraperitoneally for 4 days) was without efffect on biliary excretion of ouabain. The results suggest that spironolactone differs from phenobarbital in its enhancing effect on biliary excretion of ouabain, possibly through a specific effect on an unknown hepatic transport mechanism. (author)

  9. Differences in perfusion parameters between upper and lower lumbar vertebral segments with dynamic contrast-enhanced MRI (DCE MRI)

    International Nuclear Information System (INIS)

    Savvopoulou, Vasiliki; Vlahos, Lampros; Moulopoulos, Lia Angela; Maris, Thomas G.

    2008-01-01

    To investigate the influence of age, sex and spinal level on perfusion parameters of normal lumbar bone marrow with dynamic contrast-enhanced MRI (DCE MRI). Sixty-seven subjects referred for evaluation of low back pain or sciatica underwent DCE MRI of the lumbar spine. After subtraction of dynamic images, a region of interest (ROI) was placed on each lumbar vertebral body of all subjects, and time intensity curves were generated. Consequently, perfusion parameters were calculated. Statistical analysis was performed to search for perfusion differences among lumbar vertebrae and in relation to age and sex. Upper (L1, L2) and lower (L3, L4, L5) vertebrae showed significant differences in perfusion parameters (p<0.05). Vertebrae of subjects younger than 50 years showed significantly higher perfusion compared to vertebrae of older ones (p<0.05). Vertebrae of females demonstrated significantly increased perfusion compared to those of males of corresponding age (p<0.05). All perfusion parameters, except for washout (WOUT), showed a mild linear correlation with age. Time to maximum slope (TMSP) and time to peak (TTPK) showed the same correlation with sex (0.22< r<0.32, p<0.05). Our results indicate increased perfusion of the upper compared to the lower lumbar spine, of younger compared to older subjects and of females compared to males. (orig.)

  10. Differences in perfusion parameters between upper and lower lumbar vertebral segments with dynamic contrast-enhanced MRI (DCE MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Savvopoulou, Vasiliki; Vlahos, Lampros; Moulopoulos, Lia Angela [University of Athens, Areteion Hospital, Department of Radiology, Medical School, Athens (Greece); Maris, Thomas G. [University of Crete, Deparment of Medical Physics, Faculty of Medicine, Heraklion (Greece)

    2008-09-15

    To investigate the influence of age, sex and spinal level on perfusion parameters of normal lumbar bone marrow with dynamic contrast-enhanced MRI (DCE MRI). Sixty-seven subjects referred for evaluation of low back pain or sciatica underwent DCE MRI of the lumbar spine. After subtraction of dynamic images, a region of interest (ROI) was placed on each lumbar vertebral body of all subjects, and time intensity curves were generated. Consequently, perfusion parameters were calculated. Statistical analysis was performed to search for perfusion differences among lumbar vertebrae and in relation to age and sex. Upper (L1, L2) and lower (L3, L4, L5) vertebrae showed significant differences in perfusion parameters (p<0.05). Vertebrae of subjects younger than 50 years showed significantly higher perfusion compared to vertebrae of older ones (p<0.05). Vertebrae of females demonstrated significantly increased perfusion compared to those of males of corresponding age (p<0.05). All perfusion parameters, except for washout (WOUT), showed a mild linear correlation with age. Time to maximum slope (TMSP) and time to peak (TTPK) showed the same correlation with sex (0.22perfusion of the upper compared to the lower lumbar spine, of younger compared to older subjects and of females compared to males. (orig.)

  11. Dietary red palm oil supplementation reduces myocardial infarct size in an isolated perfused rat heart model

    Directory of Open Access Journals (Sweden)

    Esterhuyse Adriaan J

    2010-06-01

    Full Text Available Abstract Background and Aims Recent studies have shown that dietary red palm oil (RPO supplementation improves functional recovery following ischaemia/reperfusion in isolated hearts. The main aim of this study was to investigate the effects of dietary RPO supplementation on myocardial infarct size after ischaemia/reperfusion injury. The effects of dietary RPO supplementation on matrix metalloproteinase-2 (MMP2 activation and PKB/Akt phosphorylation were also investigated. Materials and methods Male Wistar rats were divided into three groups and fed a standard rat chow diet (SRC, a SRC supplemented with RPO, or a SRC supplemented with sunflower oil (SFO, for a five week period, respectively. After the feeding period, hearts were excised and perfused on a Langendorff perfusion apparatus. Hearts were subjected to thirty minutes of normothermic global ischaemia and two hours of reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining. Coronary effluent was collected for the first ten minutes of reperfusion in order to measure MMP2 activity by gelatin zymography. Results Dietary RPO-supplementation decreased myocardial infarct size significantly when compared to the SRC-group and the SFO-supplemented group (9.1 ± 1.0% versus 30.2 ± 3.9% and 27.1 ± 2.4% respectively. Both dietary RPO- and SFO-supplementation were able to decrease MMP2 activity when compared to the SRC fed group. PKB/Akt phosphorylation (Thr 308 was found to be significantly higher in the dietary RPO supplemented group when compared to the SFO supplemented group at 10 minutes into reperfusion. There was, however, no significant changes observed in ERK phosphorylation. Conclusions Dietary RPO-supplementation was found to be more effective than SFO-supplementation in reducing myocardial infarct size after ischaemia/reperfusion injury. Both dietary RPO and SFO were able to reduce MMP2 activity, which suggests that MMP2 activity does not play a major role in

  12. Chemosaturation with Percutaneous Hepatic Perfusion for Unresectable Isolated Hepatic Metastases from Sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Deneve, Jeremiah L., E-mail: Jeremiah.Deneve@Moffitt.org [Moffitt Cancer Center, Department of Cutaneous and Sarcoma Oncology (United States); Choi, Junsung [Moffitt Cancer Center, Department of Interventional Radiology (United States); Gonzalez, Ricardo J.; Conley, Anthony P.; Stewart, Steven; Han, Dale [Moffitt Cancer Center, Department of Cutaneous and Sarcoma Oncology (United States); Werner, Philip; Chaudhry, Tariq A. [Moffitt Cancer Center, Department of Anesthesia (United States); Zager, Jonathan S., E-mail: Jonathan.Zager@Moffitt.org [Moffitt Cancer Center, Department of Cutaneous and Sarcoma Oncology (United States)

    2012-12-15

    Purpose: Treatment of patients with unresectable liver metastases is challenging. Regional therapies to the liver have been developed that maximize treatment of the localized disease process without systemic toxic adverse effects. We discuss the procedural aspects of liver chemosaturation with percutaneous hepatic perfusion (CS-PHP). Methods: We present as an illustration of this technique a case report of the treatment of unresectable metastatic leiomyosarcoma of the liver. Results: A randomized phase III trial for unresectable liver metastases from melanoma was recently completed comparing CS-PHP with melphalan vs. best alternative care (BAC). When compared with BAC, CS-PHP was associated with a significant improvement in hepatic progression-free survival (8.0 months CS-PHP vs. 1.6 months BAC, p < 0.0001) and overall progression-free survival (6.7 months CS-PHP vs. 1.6 months BAC, p < 0.0001), respectively. On the basis of these results, and given our experience as one of the treating institutions for this phase III trial, we appealed for compassionate use of CS-PHP in a patient with isolated bilobar unresectable hepatic metastases from leiomyosarcoma. Four target lesions were identified and monitored to assess treatment response. A total of 4 CS-PHP procedures were performed, with a 25 % reduction in size of the largest lesion observed and 16 month hepatic progression-free survival. Toxicity was mild (neutropenia) and manageable on an outpatient basis. Conclusion: CS-PHP offers several advantages for unresectable hepatic sarcoma metastases. CS-PHP is minimally invasive and repeatable, and it has a predictable and manageable systemic toxicity profile. For appropriately selected patients, CS-PHP can delay tumor progression and could potentially improve survival.

  13. Chemosaturation with Percutaneous Hepatic Perfusion for Unresectable Isolated Hepatic Metastases from Sarcoma

    International Nuclear Information System (INIS)

    Deneve, Jeremiah L.; Choi, Junsung; Gonzalez, Ricardo J.; Conley, Anthony P.; Stewart, Steven; Han, Dale; Werner, Philip; Chaudhry, Tariq A.; Zager, Jonathan S.

    2012-01-01

    Purpose: Treatment of patients with unresectable liver metastases is challenging. Regional therapies to the liver have been developed that maximize treatment of the localized disease process without systemic toxic adverse effects. We discuss the procedural aspects of liver chemosaturation with percutaneous hepatic perfusion (CS-PHP). Methods: We present as an illustration of this technique a case report of the treatment of unresectable metastatic leiomyosarcoma of the liver. Results: A randomized phase III trial for unresectable liver metastases from melanoma was recently completed comparing CS-PHP with melphalan vs. best alternative care (BAC). When compared with BAC, CS-PHP was associated with a significant improvement in hepatic progression-free survival (8.0 months CS-PHP vs. 1.6 months BAC, p < 0.0001) and overall progression-free survival (6.7 months CS-PHP vs. 1.6 months BAC, p < 0.0001), respectively. On the basis of these results, and given our experience as one of the treating institutions for this phase III trial, we appealed for compassionate use of CS-PHP in a patient with isolated bilobar unresectable hepatic metastases from leiomyosarcoma. Four target lesions were identified and monitored to assess treatment response. A total of 4 CS-PHP procedures were performed, with a 25 % reduction in size of the largest lesion observed and 16 month hepatic progression-free survival. Toxicity was mild (neutropenia) and manageable on an outpatient basis. Conclusion: CS-PHP offers several advantages for unresectable hepatic sarcoma metastases. CS-PHP is minimally invasive and repeatable, and it has a predictable and manageable systemic toxicity profile. For appropriately selected patients, CS-PHP can delay tumor progression and could potentially improve survival.

  14. Normothermic extracorporeal perfusion of isolated porcine liver after warm ischaemia: a preliminary report.

    Science.gov (United States)

    Bellomo, Rinaldo; Suzuki, Satoshi; Marino, Bruno; Starkey, Graeme K; Chambers, Brenton; Fink, Michael A; Wang, Bao Zhong; Houston, Shane; Eastwood, Glenn; Calzavacca, Paolo; Glassford, Neil; Skene, Alison; Jones, Daryl A; Jones, Robert

    2012-09-01

    Liver transplantation is a major life-saving procedure, and donation after cardiac death (DCD) has increased the pool of potential liver donors. However, DCD livers are at increased risk of primary graft dysfunction and biliary tract ischaemia. Normothermic extracorporeal liver perfusion (NELP) may increase the ability to protect, evaluate and, in future, transplant DCD livers. We conducted proof-of-concept experiments using a DCD model in the pig to assess the short-term (4 hours) feasibility and functional efficacy of NELP. Using extracorporeal membrane oxygenation, parenteral nutrition, separate hepatic artery and portal vein perfusion, and physiological perfusion pressures, we achieved NELP and evidence of function (bile production, paracetamol removal, maintenance of normal ammonia and lactate levels) for 4 hours in pig livers subjected to 15 and 30 minutes of cardiac arrest before explantation. Our experiments justify further investigations of the feasibility and efficacy of human DCD liver preservation by ex-vivo perfusion.

  15. Extended normothermic extracorporeal perfusion of isolated human liver after warm ischaemia: a preliminary report.

    Science.gov (United States)

    Bellomo, Rinaldo; Marino, Bruno; Starkey, Graeme; Fink, Michael; Wang, Bao Zhong; Eastwood, Glenn M; Peck, Leah; Young, Helen; Houston, Shane; Skene, Alison; Opdam, Helen; Jones, Robert

    2014-09-01

    Donation after circulatory death (DCD) livers are at markedly increased risk of primary graft dysfunction and biliary tract ischaemia. Normothermic extracorporeal liver perfusion (NELP) may increase the ability to transplant DCD livers and may allow their use for artificial extracorporeal liver support of patients with fulminant liver failure. We conducted two proof-of-concept experiments using human livers after DCD to assess the feasibility and functional efficacy of NELP over an extended period. We applied extracorporeal membrane oxygenation, parenteral nutrition, separate hepatic artery and portal vein perfusion and physiological perfusion pressures to two livers obtained after DCD. We achieved NELP and evidence of liver function (bile production, paracetamol removal and maintenance of normal lactate levels) in both livers; one for 24 hours and the other for 43 hours. Histological examination showed areas of patchy ischaemia but preserved biliary ducts and canaliculi. Our experiments justify further investigations of the feasibility and efficacy of extended DCD liver preservation by ex-vivo perfusion.

  16. Cavitation enhances coagulated size during pulsed high-intensity focussed ultrasound ablation in an isolated liver perfusion system.

    Science.gov (United States)

    Zhao, Lu-Yan; Liu, Shan; Chen, Zong-Gui; Zou, Jian-Zhong; Wu, Feng

    2016-11-24

    To investigate whether cavitation enhances the degree of coagulation during pulsed high-intensity focussed ultrasound (HIFU) in an isolated liver perfusion system. Isolated liver was treated by pulsed HIFU or continuous-wave HIFU with different portal vein flow rates. The cavitation emission during exposure was recorded, and real-time ultrasound images were used to observe changes in the grey scale. The coagulation size was measured and calculated. HIFU treatment led to complete coagulation necrosis and total cell destruction in the target regions. Compared to exposure at a duty cycle (DC) of 100%, the mean volumes of lesions induced by 6 s exposure at DCs of 50% and 10% were significantly larger (P cavitation activity for the pulsed-HIFU (P > .05). For continuous-wave HIFU exposure, there was a significant decrease in the necrosis volume and cavitation activity for exposure times of 1, 2, 3, 4, and 6 s with increasing portal perfusion rates. Perfusion flow rates negatively influence cavitation activity and coagulation volume. Ablation is significantly enhanced during pulsed HIFU exposure compared with continuous-wave HIFU.

  17. Tissue ablation accelerated by peripheral scanning mode with high-intensity focused ultrasound: a study on isolated porcine liver perfusion.

    Science.gov (United States)

    Bu, Rui; Yin, Li; Yang, Han; Wang, Qi; Wu, Feng; Zou, Jian Zhong

    2013-08-01

    The aims of this study were to investigate the feasibility of accelerated tissue ablation using a peripheral scanning mode with high-intensity focused ultrasound (HIFU) and to explore the effect of flow rate on total energy consumption of the target tissues. Using a model of isolated porcine liver perfusion via the portal vein and hepatic artery, we conducted a scanning protocol along the periphery of the target tissues using linear-scanned HIFU to carefully adjust the varying focal depth, generator power, scanning velocity and line-by-line interval over the entire ablation range. Porcine livers were divided into four ablation groups: group 1, n = 12, with dual-vessel perfusion; group 2, n = 11, with portal vein perfusion alone; group 3, n = 10, with hepatic artery perfusion alone; and group 4, n = 11, control group with no-flow perfusion. The samples were cut open consecutively at a thickness of 3 mm, and the actual ablation ranges were calculated along the periphery of the target tissues after triphenyl tetrazolium chloride staining. Total energy consumption was calculated as the sum of the energy requirements at various focal depths in each group. On the basis of the pre-supposed scanning protocol, the peripheral region of the target tissue formed a complete coagulation necrosis barrier in each group with varying dose combinations, and the volume of the peripheral necrotic area did not differ significantly among the four groups (p > 0.05). Furthermore, total energy consumption in each group significantly decreased with the corresponding decrease in flow rate (p Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  18. Segmentation of isolated MR images: development and comparison of neuronal networks

    International Nuclear Information System (INIS)

    Paredes, R.; Robles, M.; Marti-Bonmati, L.; Masia, L.

    1998-01-01

    Segmentation defines the capacity to differentiate among types of tissues. In MR. it is frequently applied to volumetric determinations. Digital images can be segmented in a number of ways; neuronal networks (NN) can be employed for this purpose. Our objective was to develop algorithms for automatic segmentation using NN and apply them to central nervous system MR images. The segmentation obtained with NN was compared with that resulting from other procedures (region-growing and K means). Each NN consisted of two layers: one based on unsupervised training, which was utilized for image segmentation in sets of K, and a second layer associating each set obtained by the preceding layer with the real set corresponding to the previously segmented objective image. This NN was trained with previously segmented images with supervised regions-growing algorithms and automatic K means. Thus, 4 different segmentation were obtained: region-growing, K means, NN with region-growing and NN with K means. The tissue volumes corresponding to cerebrospinal fluid, gray matter and white matter obtained with the 4 techniques were compared and the most representative segmented image was selected qualitatively by averaging the visual perception of 3 radiologists. The segmentation that best corresponded to the visual perception of the radiologists was that consisting of trained NN with region-growing. In comparison, the other 3 algorithms presented low percentage differences (mean, 3.44%). The mean percentage error for the 3 tissues from these algorithms was lower for region-growing segmentation (2.34%) than for trained NN with K means (3.31%) and for automatic K-means segmentation (4.66%). Thus, NN are reliable in the automation of isolated MR image segmentation. (Author) 12 refs

  19. A fuzzy feature fusion method for auto-segmentation of gliomas with multi-modality diffusion and perfusion magnetic resonance images in radiotherapy.

    Science.gov (United States)

    Guo, Lu; Wang, Ping; Sun, Ranran; Yang, Chengwen; Zhang, Ning; Guo, Yu; Feng, Yuanming

    2018-02-19

    The diffusion and perfusion magnetic resonance (MR) images can provide functional information about tumour and enable more sensitive detection of the tumour extent. We aimed to develop a fuzzy feature fusion method for auto-segmentation of gliomas in radiotherapy planning using multi-parametric functional MR images including apparent diffusion coefficient (ADC), fractional anisotropy (FA) and relative cerebral blood volume (rCBV). For each functional modality, one histogram-based fuzzy model was created to transform image volume into a fuzzy feature space. Based on the fuzzy fusion result of the three fuzzy feature spaces, regions with high possibility belonging to tumour were generated automatically. The auto-segmentations of tumour in structural MR images were added in final auto-segmented gross tumour volume (GTV). For evaluation, one radiation oncologist delineated GTVs for nine patients with all modalities. Comparisons between manually delineated and auto-segmented GTVs showed that, the mean volume difference was 8.69% (±5.62%); the mean Dice's similarity coefficient (DSC) was 0.88 (±0.02); the mean sensitivity and specificity of auto-segmentation was 0.87 (±0.04) and 0.98 (±0.01) respectively. High accuracy and efficiency can be achieved with the new method, which shows potential of utilizing functional multi-parametric MR images for target definition in precision radiation treatment planning for patients with gliomas.

  20. Processing of pulse oximeter signals using adaptive filtering and autocorrelation to isolate perfusion and oxygenation components

    Science.gov (United States)

    Ibey, Bennett; Subramanian, Hariharan; Ericson, Nance; Xu, Weijian; Wilson, Mark; Cote, Gerard L.

    2005-03-01

    A blood perfusion and oxygenation sensor has been developed for in situ monitoring of transplanted organs. In processing in situ data, motion artifacts due to increased perfusion can create invalid oxygenation saturation values. In order to remove the unwanted artifacts from the pulsatile signal, adaptive filtering was employed using a third wavelength source centered at 810nm as a reference signal. The 810 nm source resides approximately at the isosbestic point in the hemoglobin absorption curve where the absorbance of light is nearly equal for oxygenated and deoxygenated hemoglobin. Using an autocorrelation based algorithm oxygenation saturation values can be obtained without the need for large sampling data sets allowing for near real-time processing. This technique has been shown to be more reliable than traditional techniques and proven to adequately improve the measurement of oxygenation values in varying perfusion states.

  1. 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

  2. Post ischemic reperfusion and anoxic perfusion in the isolated heart: alteration in distribution of radionuclides and in protein synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, S S; Oratz, M; Rothschild, M A [Veterans Administration Hospital, New York (USA)

    1980-12-01

    Reperfusion after ischemia and perfusion with total anoxia were studied in the isolated guinea pig heart model, Deprivation of oxygen in both situations resulted in a marked shift of circulation from the left to the right ventricle, with markedly increased spaces of distribution of sup(99m)Tc radionuclides and albumin in the latter. In view of the complexities of measuring protein synthesis during ischemia, continuous anoxic perfusion was used to evaluate this parameter in anoxic induced arrest. There was a profound fall in protein synthesis associated with this arrest, accompanied by a fall in ATP, creatine phosphate, glycogen, potassium, and a rise in lactate production. The fall in protein synthesis was more marked in the left ventricle. The changes in synthesis were almost completely prevented by initiating cardiac arrest with high K/sup +/ (16 meq/l) at the same time as anoxia; energy metabolism remained near normal, and recovery of contractility was nearly complete. The studies demonstrated the differences in vascular distribution between the ventricles after ischemia or with perfusion anoxia, the possible difference in availability of substrate to the two ventricles under these conditions, as well as the difference in protein synthetic response, and further support the protective effect of potassium induced arrest on the hypoxic heart.

  3. Perfusion-induced changes in cardiac contractility depend on capillary perfusion.

    Science.gov (United States)

    Dijkman, M A; Heslinga, J W; Sipkema, P; Westerhof, N

    1998-02-01

    The perfusion-induced increase in cardiac contractility (Gregg phenomenon) is especially found in heart preparations that lack adequate coronary autoregulation and thus protection of changes in capillary pressure. We determined in the isolated perfused papillary muscle of the rat whether cardiac muscle contractility is related to capillary perfusion. Oxygen availability of this muscle is independent of internal perfusion, and perfusion may be varied or even stopped without loss of function. Muscles contracted isometrically at 27 degrees C (n = 7). During the control state stepwise increases in perfusion pressure resulted in all muscles in a significant increase in active tension. Muscle diameter always increased with increased perfusion pressure, but muscle segment length was unaffected. Capillary perfusion was then obstructed by plastic microspheres (15 microns). Flow, at a perfusion pressure of 66.6 +/- 26.2 cmH2O, reduced from 17.6 +/- 5.4 microliters/min in the control state to 3.2 +/- 1.3 microliters/min after microspheres. Active tension developed by the muscle in the unperfused condition before microspheres and after microspheres did not differ significantly (-12.8 +/- 29.4% change). After microspheres similar perfusion pressure steps as in control never resulted in an increase in active tension. Even at the two highest perfusion pressures (89.1 +/- 28.4 and 106.5 +/- 31.7 cmH2O) that were applied a significant decrease in active tension was found. We conclude that the Gregg phenomenon is related to capillary perfusion.

  4. Role of glycolysis in maintenance of the action potential duration and contractile activity in isolated perfused rat heart.

    Science.gov (United States)

    Opie, L H; Tuschmidt, R; Bricknell, O; Girardier, L

    1980-01-01

    1. Changing substrates from glucose to pyruvate in paced isolated rat hearts, perfused by the Langendorff technique at 65 cm H2O with a Krebs-Henseleit bicarbonate buffer, produced effects which are opposite to those of ouabain treatment: negative inotropy, decreased work efficiency, hyperpolarization, increased maximum rate of rise and amplitude of the action potential, increased conduction velocity. 2. All the effects resulting from perfusion with pyruvate can be reversed by adding ouabain at a concentration of 100 microM. 3. The correlation between various tissue metabolises and change in contractile force (delta F), rate of tension development [maximum + (dF/dt)] and rate of relaxation [maximum -(dF/dt)] was studied by multiple linear regression. No significant correlation was found with either glycogen content and tissue lactate or with cAMP and cGMP. A weak negative correlation was found with ATP and phosphocreatine. The strongest correlation was found 76 to 807 nM/g in passing from glucose- to pyruvate-containing perfusion solution. 4. In vitro tests performed with a solution containing high energy phosphates and magnesium at concentrations equal to their calculated values in the cytosol (pH 7.0) showed that a significant negative correlation exists between citrate concentration (range: 1 and 1500 M) and free calcium concentration in the micromole range. 5. It is concluded that the effects of pyruvate (non glucose substrate) perfusion could be mediated by a decrease in cytosolic-free calcium resulting from an increase in intracellular citrate. The observation that all these effects can be reversed by ouabain is taken as a circumstantial evidence of a common mechanism.

  5. Epicardial excitation pattern as observed in the isolated revived and perfused fetal human heart

    NARCIS (Netherlands)

    Durrer, D.; Büller, J.; Graaff, P.; Lo, G.I.; Meijler, F.L.

    1961-01-01

    The resuscitated fetal human heart can be used as an experimental tooI for the investigation of the excitatory process in the human heart. During perfusion the configuration of the epicardial electrocardiograms does not change appreciably. For accurate recording permitting a detailed analysis, the

  6. Vasopressin-induced constriction of the isolated rat occipital artery is segment dependent.

    Science.gov (United States)

    Chelko, Stephen P; Schmiedt, Chad W; Lewis, Tristan H; Lewis, Stephen J; Robertson, Tom P

    2013-01-01

    Circulating factors delivered to the nodose ganglion (NG) by the occipital artery (OA) have been shown to affect vagal afferent activity, and thus the contractile state of the OA may influence blood flow to the NG. OA were isolated and bisected into proximal and distal segments relative to the external carotid artery. Bisection highlighted stark differences between maximal contractile responses and OA sensitivity. Specifically, maximum responses to vasopressin and the V1 receptor agonist were significantly higher in distal than proximal segments. Distal segments were significantly more sensitive to 5-hydroxytryptamine (5-HT) and the 5-HT2 receptor agonist than proximal segments. Angiotensin II (AT)2, V2 and 5-HT(1B/1D) receptor agonists did not elicit vascular responses. Additionally, AT1 receptor agonists elicited mild, yet not significantly different maximal responses between segments. The results of this study are consistent with contractile properties of rat OA being mediated via AT1, V1 and 5-HT2 receptors and dependent upon the OA segment. Furthermore, vasopressin-induced constriction of the OA, regardless of a bolus dose or a first and second concentration-response curve, retained this unique segmental difference. We hypothesize that these segmental differences may be important in the regulation of blood flow through the OA in health and disease. © 2013 S. Karger AG, Basel.

  7. MSCs can be differentially isolated from maternal, middle and fetal segments of the human umbilical cord.

    Science.gov (United States)

    Lim, Jezamine; Razi, Zainul Rashid Mohamad; Law, Jiaxian; Nawi, Azmawati Mohammed; Idrus, Ruszymah Binti Haji; Ng, Min Hwei

    2016-12-01

    Human Wharton's jelly-derived mesenchymal stromal cells (hWJMSCs) are possibly the most suitable allogeneic cell source for stromal cell therapy and tissue engineering applications because of their hypo-immunogenic and non-tumorigenic properties, easy availability and minimal ethical concerns. Furthermore, hWJMSCs possess unique properties of both adult mesenchymal stromal cells and embryonic stromal cells. The human umbilical cord (UC) is approximately 50-60 cm long and the existing studies in the literature have not provided information on which segment of the UC was studied. In this study, hWJMSCs derived from three anatomical segments of the UC are compared. Three segments of the whole UC, each 3 cm in length, were identified anatomically as the maternal, middle and fetal segments. The hWJMSCs from the different segments were analyzed via trypan blue exclusion assay to determine the growth kinetics and cell viability, flow cytometry for immunophenotyping and immunofluorescence and reverse transcriptase polymerase chain reaction (RT-PCR) for expression of stromal cell transcriptional factors. Furthermore, the trilineage differentiation potential (osteogenic, adipogenic and chondrogenic) of these cells was also assessed. hWJMSCs isolated from the maternal and fetal segments displayed greater viability and possessed a significantly higher proliferation rate compared with cells from the middle segment. Immunophenotyping revealed that hWJMSCs derived from all three segments expressed the MSC markers CD105, CD73, CD90, CD44, CD13 and CD29, as well as HLA-ABC and HLA-DR, but were negative for hematopoietic markers CD14, CD34 and CD45. Analysis of the embryonic markers showed that all three segments expressed Nanog and Oct 3/4, but only the maternal and fetal segments expressed SSEA 4 and TRA-160. Cells from all three segments were able to differentiate into chondrogenic, osteogenic and adipogenic lineages with the middle segments showing much lower differentiation

  8. Effects of lysosomal inhibitors on 125I-insulin and 125I-asialofetuin degradation by the isolated, perfused rat liver and isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Ward, W.F.; Moss, A.L.

    1985-01-01

    To further evaluate the role of the lysosomal system in insulin degradation, the authors have compared the effects of inhibitors of lysosomal function on the degradation of 125 I-insulin with 125 I-asialofetuin, a lysosomally targeted molecule, by the intact, perfused rat liver and the isolated rat hepatocyte. The inhibitors employed were chloroquine ( 125 microM), NH 4 Cl (10 mM), and leupeptin (50 micrograms/ml). In the intact, perfused liver the observed inhibition of 125 I-asialofetuin degradation at 30 min was as follows: chloroquine, 38%; NH 4 Cl, 32%; and leupeptin, 86%. Chloroquine also inhibited 125 I-insulin degradation in the intact, perfused liver (29%), but NH 4 Cl and leupeptin had no effect. Using the isolated hepatocyte, the observed values for inhibition of 125I-asialofetuin at 60 min were: chloroquine, 85%; NH 4 Cl, 76%; and leupeptin, 81%. Chloroquine produced a 28% inhibition of 125I-insulin degradation, while NH 4 Cl and leupeptin had no effect. Chloroquine and NH 4 Cl decreased cell-associated radioactivity when isolated hepatocytes were incubated with 125I-asialofetuin (leupeptin had no effect), whereas chloroquine caused a 107% increase in cell-associated radioactivity when 125I-insulin was added to the incubation media (NH 4 Cl and leupeptin had no effect). These results indicate that the effects of chloroquine on insulin degradation are an extralysosomal action and that lysosomes appear not to be involved in the physiologic degradation of the insulin molecule

  9. Radionuclide leakage monitoring during hyperthermic isolated limb perfusion for treatment of local melanoma metastasis in an extremity

    DEFF Research Database (Denmark)

    Paulsen, Ida F; Chakera, Annette Hougaard; Schmidt, Grethe

    2015-01-01

    (99m) Tc-labelled tracer infused into the isolated limb circulation. RESULTS: One hundred and sixteen of 131 procedures were completed. In 13%, a leakage of ≥10% was detected; in 6% (n = 8), the cytotoxic drug was never infused because of constant leakage; in 7% (n = 9), leakage ≥10% was measured......INTRODUCTION: The aim is to describe the importance of leakage monitoring in hyperthermic isolated limb perfusion (ILP). It is generally recommended that leakage should not exceed 10% because of risk of systemic toxicity. MATERIAL AND METHODS: Data retrieved by retrospective analysis of 131...... were observed in 14%. Three of the patients with leakage ≥10% were successfully treated in a repeated procedure. CONCLUSION: Leakage monitoring using a threshold of 10% during ILP saves the patients from systemic toxicity, however, at the expense of early termination or cancellation of ILP treatment...

  10. Biosynthesis of agmatine in isolated mitochondria and perfused rat liver: studies with 15N-labelled arginine

    Science.gov (United States)

    2005-01-01

    An important but unresolved question is whether mammalian mitochondria metabolize arginine to agmatine by the ADC (arginine decarboxylase) reaction. 15N-labelled arginine was used as a precursor to address this question and to determine the flux through the ADC reaction in isolated mitochondria obtained from rat liver. In addition, liver perfusion system was used to examine a possible action of insulin, glucagon or cAMP on a flux through the ADC reaction. In mitochondria and liver perfusion, 15N-labelled agmatine was generated from external 15N-labelled arginine. The production of 15N-labelled agmatine was time- and dose-dependent. The time-course of [U-15N4]agmatine formation from 2 mM [U-15N4]arginine was best fitted to a one-phase exponential curve with a production rate of approx. 29 pmol·min−1·(mg of protein)−1. Experiments with an increasing concentration (0– 40 mM) of [guanidino-15N2]arginine showed a Michaelis constant Km for arginine of 46 mM and a Vmax of 3.7 nmol·min−1·(mg of protein)−1 for flux through the ADC reaction. Experiments with broken mitochondria showed little changes in Vmax or Km values, suggesting that mitochondrial arginine uptake had little effect on the observed Vmax or Km values. Experiments with liver perfusion demonstrated that over 95% of the effluent agmatine was derived from perfusate [guanidino-15N2]arginine regardless of the experimental condition. However, the output of 15N-labelled agmatine (nmol·min−1·g−1) increased by approx. 2-fold (P<0.05) in perfusions with cAMP. The findings of the present study provide compelling evidence that mitochondrial ADC is present in the rat liver, and suggest that cAMP may stimulate flux through this pathway. PMID:15656789

  11. Tumour response after hyperthermic isolated limb perfusion for locally advanced melanoma

    DEFF Research Database (Denmark)

    Paulsen, Ida Felbo; Chakera, A H; Drejøe, Jennifer Berg

    2014-01-01

    AND METHODS: A total of 84 perfusions were performed (53 women, 31 men, median age 63 years) from 1993 to 2010. 95% of the perfusions were administered to the lower limbs and 5% to the upper limbs. The inclusion criteria were recurrent and/or clinically apparent cutaneous/subcutaneous extremity in....... Time from ILP to recurrence was a median of seven months (range 1-37 months) for patients with CR or PR. Survival was longer for patients with CR or PR than for patients showing NC or progression. Several patients had mild or moderate local toxicity reactions, two patients developed severe local...... to improve local disease control in patients with multiple and/or recurrent melanoma confined to an extremity if surgical excision is not possible. FUNDING: not relevant. TRIAL REGISTRATION: not relevant....

  12. Vasopressin-induced constriction of the isolated rat occipital artery is segment-dependent

    Science.gov (United States)

    Chelko, Stephen P.; Schmiedt, Chad W.; Lewis, Tristan H.; Lewis, Stephen J.; Robertson, Tom P.

    2014-01-01

    Background Circulating factors delivered to the nodose ganglion (NG) by the occipital artery (OA) have shown to affect vagal afferent activity, and thus the contractile state of the OA may influence blood flow to the NG. Methods OA were isolated and bisected into proximal and distal segments, relative to the external carotid artery. Results Bisection, highlighted stark differences between maximal contractile responses and OA sensitivity. Specifically, maximum responses to vasopressin and the V1 receptor agonist, were significantly higher in distal than proximal segments. Distal segments were significantly more sensitive to 5-HT and the 5-HT2 receptor agonist than proximal segments. AT2, V2 and 5-HT1B/1D receptor agonists did not elicit vascular responses. Additionally, AT1 receptor agonists elicited mild, yet not significantly different maximal responses between segments. Conclusion The results of this study are consistent with contractile properties of rat OA being mediated via AT1, V1 and 5-HT2 receptors, and are dependent upon the OA segment. Furthermore, vasopressin-induced constriction of the OA, regardless of a bolus dose or a first and second concentration response curve retained this unique segmental difference and therefore we hypothesize this may be a pathophysiological response in the regulation of blood flow through the OA. PMID:24192548

  13. The DD genotype of the angiotensin converting enzyme gene independently associates with CMR-derived abnormal microvascular perfusion in patients with a first anterior ST-segment elevation myocardial infarction treated with thrombolytic agents.

    Science.gov (United States)

    Bodi, Vicente; Sanchis, Juan; Nunez, Julio; Aliño, Salvador F; Herrero, Maria J; Chorro, Francisco J; Mainar, Luis; Lopez-Lereu, Maria P; Monmeneu, Jose V; Oltra, Ricardo; Chaustre, Fabian; Forteza, Maria J; Husser, Oliver; Riegger, Günter A; Llacer, Angel

    2009-12-01

    The role of the angiotensin converting enzyme (ACE) gene on the result of thrombolysis at the microvascular level has not been addressed so far. We analyzed the implications of the insertion/deletion (I/D) polymorphism of the ACE gene on the presence of abnormal cardiovascular magnetic resonance (CMR)-derived microvascular perfusion after ST-segment elevation myocardial infarction (STEMI). We studied 105 patients with a first anterior STEMI treated with thrombolytic agents and an open left anterior descending artery. Microvascular perfusion was assessed using first-pass perfusion CMR at 7+/-1 days. CMR studies were repeated 184+/-11 days after STEMI. The ACE gene insertion/deletion (I/D) polymorphism was determined using polymerase chain reaction amplification. Overall genotype frequencies were II-ID 58% and DD 42%. Abnormal perfusion (> or = 1 segment) was detected in 56% of patients. The DD genotype associated to a higher risk of abnormal microvascular perfusion (68% vs. 47%, p=0.03) and to a larger extent of perfusion deficit (median [percentile 25 - percentile 75]: 4 [0-6] vs. 0 [0-4] segments, p=0.003). Once adjusted for baseline characteristics, the DD genotype independently increased the risk of abnormal microvascular perfusion (odds ratio [95% confidence intervals]: 2.5 [1.02-5.9], p=0.04). Moreover, DD patients displayed a larger infarct size (35+/-17 vs. 27+/-15 g, p=0.01) and a lower ejection fraction at 6 months (48+/-14 vs. 54+/-14%, p=0.03). The DD genotype associates to a higher risk of abnormal microvascular perfusion after STEMI.

  14. Prevalence of first-pass myocardial perfusion defects detected by contrast-enhanced dual-source CT in patients with non-ST segment elevation acute coronary syndromes

    Energy Technology Data Exchange (ETDEWEB)

    Schepis, Tiziano; Achenbach, Stephan; Marwan, Mohamed; Muschiol, Gerd; Ropers, Dieter; Daniel, Werner G.; Pflederer, Tobias [University of Erlangen, Department of Internal Medicine 2 (Cardiology), Erlangen (Germany)

    2010-07-15

    To investigate the prevalence and diagnostic value of first-pass myocardial perfusion defects (PD) visualised by contrast-enhanced multidetector computed tomography (MDCT) in patients admitted for a first acute coronary syndrome (ACS). Thirty-eight patients with non-ST segment elevation myocardial infarction (NSTEMI) or unstable angina (UA) and scheduled for percutaneous coronary intervention underwent dual-source CT immediately before catheterisation. CT images were analysed for the presence of any PD by using a 17-segment model. Results were compared with peak cardiac troponin-I (cTnI) and angiography findings. PD were seen in 21 of the 24 patients with NSTEMI (median peak cTnI level 7.07 ng/mL; range 0.72-37.07 ng/mL) and in 2 of 14 patients with UA. PD corresponded with the territory of the infarct-related artery in 20 out of 22 patients. In a patient-based analysis, sensitivity, specificity, negative and positive predictive values of any PD for predicting NSTEMI were 88%, 86%, 80% and 91%. Per culprit artery, the respective values were 86%, 75%, 80% and 83%. In patients with non-ST segment elevation ACS, first-pass myocardial PD in contrast-enhanced MDCT correlate closely with the presence of myocardial necrosis, as determined by increases in cTnI levels. (orig.)

  15. Myocardial Creatine Levels Do Not Influence Response to Acute Oxidative Stress in Isolated Perfused Heart

    Science.gov (United States)

    Aksentijević, Dunja; Zervou, Sevasti; Faller, Kiterie M. E.; McAndrew, Debra J.; Schneider, Jurgen E.; Neubauer, Stefan; Lygate, Craig A.

    2014-01-01

    Background Multiple studies suggest creatine mediates anti-oxidant activity in addition to its established role in cellular energy metabolism. The functional significance for the heart has yet to be established, but antioxidant activity could contribute to the cardioprotective effect of creatine in ischaemia/reperfusion injury. Objectives To determine whether intracellular creatine levels influence responses to acute reactive oxygen species (ROS) exposure in the intact beating heart. We hypothesised that mice with elevated creatine due to over-expression of the creatine transporter (CrT-OE) would be relatively protected, while mice with creatine-deficiency (GAMT KO) would fare worse. Methods and Results CrT-OE mice were pre-selected for creatine levels 20–100% above wild-type using in vivo 1H–MRS. Hearts were perfused in isovolumic Langendorff mode and cardiac function monitored throughout. After 20 min equilibration, hearts were perfused with either H2O2 0.5 µM (30 min), or the anti-neoplastic drug doxorubicin 15 µM (100 min). Protein carbonylation, creatine kinase isoenzyme activities and phospho-PKCδ expression were quantified in perfused hearts as markers of oxidative damage and apoptotic signalling. Wild-type hearts responded to ROS challenge with a profound decline in contractile function that was ameliorated by co-administration of catalase or dexrazoxane as positive controls. In contrast, the functional deterioration in CrT-OE and GAMT KO hearts was indistinguishable from wild-type controls, as was the extent of oxidative damage and apoptosis. Exogenous creatine supplementation also failed to protect hearts from doxorubicin-induced dysfunction. Conclusions Intracellular creatine levels do not influence the response to acute ROS challenge in the intact beating heart, arguing against creatine exerting (patho-)physiologically relevant anti-oxidant activity. PMID:25272153

  16. Water permeability of acinar cell membranes in the isolated perfused rabbit mandibular salivary gland.

    Science.gov (United States)

    Steward, M C; Seo, Y; Rawlings, J M; Case, R M

    1990-01-01

    1. The diffusive water permeability of epithelial cell membranes in the perfused rabbit mandibular salivary gland was measured at 37 degrees C by a 1H nuclear magnetic resonance relaxation method using an extracellular relaxation reagent, gadolinium diethylenetriaminepentaacetic acid (Gd(DTPA)). 2. In glands perfused with a HEPES-buffered solution containing 10 mmol l-1 Gd(DTPA), the spin-lattice (T1) relaxation of the water protons showed two exponential components. The water compartment responsible for the slower component corresponded in magnitude to 71 +/- 5% of the wet weight of the gland, and was attributed to the exchangeable intracellular water of the acinar cells. 3. The rate constant for water efflux from the cells was estimated to be 4.1 +/- 0.1 s-1 which would be consistent with a diffusive membrane permeability (Pd) of approximately 3 x 10(-3) cm s-1. Stimulation with acetylcholine (10(-6) mol l-1) did not cause any detectable change in membrane water permeability. 4. Since the basolateral membrane probably provides the main pathway for water efflux, the osmotic water permeability of this barrier (expressed per gland) was estimated to be less than 6.2 cm3 s-1. This would be insufficient to account for the generation of a near-isosmotic fluid at the flow rates observed during secretion, and suggests that a substantial fraction of the flow of water occurs via a paracellular route. PMID:1966053

  17. Stress-induced ST-segment deviation in relation to the presence and severity of coronary artery disease in patients with normal myocardial perfusion imaging.

    Science.gov (United States)

    Weinsaft, Jonathan W; Manoushagian, Shant J; Patel, Taral; Shakoor, Aqsa; Kim, Robert J; Mirchandani, Sunil; Lin, Fay; Wong, Franklin J; Szulc, Massimiliano; Okin, Peter M; Kligfield, Paul D; Min, James K

    2009-01-01

    To assess the utility of stress electrocardiography (ECG) for identifying the presence and severity of obstructive coronary artery disease (CAD) defined by coronary computed tomographic angiography (CCTA) among patients with normal nuclear myocardial perfusion imaging (MPI). The study population comprised 119 consecutive patients with normal MPI who also underwent CCTA (interval 3.5+/-3.8 months). Stress ECG was performed at the time of MPI. CCTA and MPI were interpreted using established scoring systems, and CCTA was used to define the presence and extent of CAD, which was quantified by a coronary artery jeopardy score. Within this population, 28 patients (24%) had obstructive CAD identified by CCTA. The most common CAD pattern was single-vessel CAD (61%), although proximal vessel involvement was present in 46% of patients. Patients with CAD were nearly three times more likely to have positive standard test responses (1 mm ST-segment deviation) than patients with patent coronary arteries (36 vs. 13%, P=0.007). In multivariate analysis, a positive ST-segment test response was an independent marker for CAD (odds ratio: 2.02, confidence interval: 1.09-3.78, P=0.03) even after adjustment for a composite of clinical cardiac risk factors (odds ratio: 1.85, confidence interval: 1.05-3.23, P=0.03). Despite uniformly normal MPI, mean coronary jeopardy score was three-fold higher among patients with positive compared to those with negative ST-segment response to exercise or dobutamine stress (1.9+/-2.7 vs. 0.5+/-1.4, P=0.03). Stress-induced ST-segment deviation is an independent marker for obstructive CAD among patients with normal MPI. A positive stress ECG identifies patients with a greater anatomic extent of CAD as quantified by coronary jeopardy score.

  18. Isolated limb perfusion with tumor necrosis factor alpha and melphalan for locally advanced soft tissue sarcoma : Three time periods at risk for amputation

    NARCIS (Netherlands)

    van Ginkel, Robert J.; Thijssens, Katja M. J.; Pras, Elisabeth; van der Graaf, Winette T. A.; Suurmeijer, Albert J. H.; Hoekstra, Harald J.

    Background: The aim of this study was to investigate the long-term limb salvage rate and overall survival after isolated limb perfusion (ILP) with tumor necrosis factor alpha and melphalan for locally advanced soft tissue sarcoma (STS). Methods: From 1991 to 2003, 73 patients (36 men, 37 women,

  19. Isolated limb perfusion with tumor necrosis factor alpha and melphalan for locally advanced soft tissue sarcoma : The value of adjuvant radiotherapy

    NARCIS (Netherlands)

    Thijssens, KMJ; van Ginkel, RJ; Pras, E; Suurmeijer, AJH; Hoekstra, HJ

    Background: The aim was to investigate the value of adjuvant radiotherapy for locally advanced soft tissue sarcoma after hyperthermic isolated limb perfusion (ILP) with tumor necrosis factor alpha and melphalan followed by limb-saving surgery. Methods: From 1991 to 2003, 73 patients (median age, 54

  20. The effect of adrenaline and high Ca2+ on the mechanical performance and oxygen consumption of the isolated perfused trout (Oncorhynchus mykiss) heart

    DEFF Research Database (Denmark)

    Rytter, Dorte; Gesser, Hans

    2007-01-01

    In heart muscle from mammals, catecholamines frequently evoke an oxygen waste and reduce efficiency. It was examined if this also applies to fish in which heart muscle activity is often restricted by oxygen availability. In the isolated perfused heart from rainbow trout, adrenaline (0.5 micro...

  1. Is chronic ST segment elevation a marker of myocardial non viability in patients with Q wave anteroseptal MI? Correlation with myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Padma, S.; Zachariah, M.; Haridas, K.K.

    2004-01-01

    Persistence of ST segment elevation for more than 2-4 weeks in patients with acute antero septal transmural myocardial infarction (ASMI) is considered to be a specific marker of left ventricular aneurysm. Objective: We attempted to assess the face value of this statement by correlating the findings of 99m Tc Sestamibi Myocardial perfusion SPECT (MPSPECT), one of the most specific modalities of myocardial viability assessment with resting 12 lead ECG. METHOD: 240 ASMI patients (192:48 Male: Female pts, age range 36-71 yrs Mean 51±8 yrs) referred for risk stratification to our department between Jan 02 -Jan 04 were retrospectively analysed. The baseline demographic details and LV systolic function parameters were more or less the same for all these patients. The mean LV EF at rest was 40±6 %. All these patients fulfilled the following inclusion criteri 1) Patients with Q Wave ASMt more than 1 month old, 2) ECG at rest showing sinus rhythm, QRS 1.5 mm. Patients with atrial arrhythmias and bundle branch block were excluded. All these patients underwent same day rest stress gated 99m Tc MIBI/ tetrofosmin MPSPECT on a dual head variable angle gamma camera. Patients performed either conventional treadmill stress or taken up for pharmacological stress. LAD territory myocardial segments (i.e. apex, anterior, septal) were evaluated for the presence of reversible ischaemia / viable myocardium. Images were visually interpreted and using a 16 segment myocardial model quantification was also performed. Presence of reversible perfusion defects, uptake of MIBI at rest more than 40 % and myocardial systolic wall thickening (count increase by at least 10% during systole) were considered as markers of viability. Results' Patients were categorized into two groups. ST elevation positive i.e. patients with rest ST elevation > 1.5 mm (137 pts 57%) and ST elevation negative (103 pts 37%) by the rest ECG criteria. In ST positive group, 47/137 pts (34%) showed viability (mean viable

  2. Is chronic st segment elevation a marker of myocardial non viability in patients with Q wave anteroseptal mi? - correlation with myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Padma, S; Zachariah, M.; Haridas, K K

    2004-01-01

    Persistence of ST segment elevation for more than 2-4 weeks in patients with acute antero septal transmural myocardial infarction (ASMI) is considered to be a specific marker of left ventricular aneurysm. Objective: We attempted to assess the face value of this statement by correlating the findings of 99m -Tc Sestamibi Myocardial perfusion SPECT (MPSPECT), one of the most specific modalities of myocardial viability assessment with resting 12 lead ECG. Method: 240 ASMI patients (192:48 Male: Female pts, age range 36-71 yrs Mean 51±8 yrs) referred for risk stratification to our department between Jan 02 -Jan 04 were retrospectively analysed. The baseline demographic details and LV systolic function parameters were more or less the same for all these patients. The mean LV EF at rest was 40±6 %. All these patients fulfilled the following inclusion criteria: 1) Patients with Q Wave ASMI more than l month old, 2) ECG at rest showing sinus rhythm, QRS 1.5 mm. Patients with atrial arrhythmias and bundle branch block were excluded. All these patients underwent same day rest stress gated 99m Tc MIBI/ tetrofosmin MPSPECT on a dual head variable angle gamma camera. Patients performed either conventional treadmill stress or taken up for pharmacological stress. LAD territory myocardial segments (i.e. apex, anterior, septal) were evaluated for the presence of reversible ischaemia/viable myocardium. Images were visually interpreted and using a 16 segment myocardial model quantification was also performed. Presence of reversible perfusion defects, uptake of MIBI at rest more than 40% and myocardial systolic wall thickening (count increase by at least 10% during systole) were considered as markers of viability. Results: Patients were categorized into two groups. ST elevation positive i.e. patients with rest ST elevation > 1.5 mm (137 pts 57%) and ST elevation negative (103 pts 37%) by the rest ECG criteria. In ST positive group, 47/137 pts (34%) showed viability (mean viable

  3. Cytoplasmic binding and disposition kinetics of diclofenac in the isolated perfused rat liver

    Science.gov (United States)

    Weiss, Michael; Kuhlmann, Olaf; Hung, Daniel Y; Roberts, Michael S

    2000-01-01

    The binding kinetics of diclofenac to hepatocellular structures were evaluated in the perfused rat liver using the multiple indicator dilution technique and a stochastic model of organ transit time density.The single-pass, in situ rat liver preparation was perfused with buffer solution (containing 2% albumin) at 30 ml min−1. Diclofenac and [14C]-sucrose (extracellular reference) were injected simultaneously as a bolus dose into the portal vein (six experiments in three rats). An analogous series of experiments was performed with [14C]-diclofenac and [3H]-sucrose.The diclofenac outflow data were analysed using three models of intracellular distribution kinetics, assuming (1) instantaneous distribution and binding (well-mixed model), (2) ‘slow' binding at specific intracellular sites after instantaneous distribution throughout the cytosol (slow binding model), and (3) ‘slowing' of cytoplasmic diffusion due to instantaneous binding (slow diffusion model).The slow binding model provided the best description of the data. The rate constants for cellular influx and sequestration were 0.126±0.026 and 0.013±0.009 s−1, respectively. The estimated ratio of cellular initial distribution volume to extracellular volume of 2.82 indicates an almost instantaneous distribution in the cellular water space, while the corresponding ratio of 5.54 estimated for the apparent tissue distribution volume suggests a relatively high hepatocellular binding. The non-instantaneous intracellular equilibration process was characterized by time constants of the binding and unbinding process of 53.8 and 49.5 s, respectively. The single-pass availability of diclofenac was 86%. The results obtained with [14C]-diclofenac and [3H]-sucrose were not statistically different. PMID:10903973

  4. Region of interest-based versus whole-lung segmentation-based approach for MR lung perfusion quantification in 2-year-old children after congenital diaphragmatic hernia repair

    Energy Technology Data Exchange (ETDEWEB)

    Weis, M.; Sommer, V.; Hagelstein, C.; Schoenberg, S.O.; Neff, K.W. [Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Zoellner, F.G. [Heidelberg University, Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Mannheim (Germany); Zahn, K. [University of Heidelberg, Department of Paediatric Surgery, University Medical Center Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Schaible, T. [Heidelberg University, Department of Paediatrics, University Medical Center Mannheim, Medical Faculty Mannheim, Mannheim (Germany)

    2016-12-15

    With a region of interest (ROI)-based approach 2-year-old children after congenital diaphragmatic hernia (CDH) show reduced MR lung perfusion values on the ipsilateral side compared to the contralateral. This study evaluates whether results can be reproduced by segmentation of whole-lung and whether there are differences between the ROI-based and whole-lung measurements. Using dynamic contrast-enhanced (DCE) MRI, pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) were quantified in 30 children after CDH repair. Quantification results of an ROI-based (six cylindrical ROIs generated of five adjacent slices per lung-side) and a whole-lung segmentation approach were compared. In both approaches PBF and PBV were significantly reduced on the ipsilateral side (p always <0.0001). In ipsilateral lungs, PBF of the ROI-based and the whole-lung segmentation-based approach was equal (p=0.50). In contralateral lungs, the ROI-based approach significantly overestimated PBF in comparison to the whole-lung segmentation approach by approximately 9.5 % (p=0.0013). MR lung perfusion in 2-year-old children after CDH is significantly reduced ipsilaterally. In the contralateral lung, the ROI-based approach significantly overestimates perfusion, which can be explained by exclusion of the most ventral parts of the lung. Therefore whole-lung segmentation should be preferred. (orig.)

  5. Region of interest-based versus whole-lung segmentation-based approach for MR lung perfusion quantification in 2-year-old children after congenital diaphragmatic hernia repair

    International Nuclear Information System (INIS)

    Weis, M.; Sommer, V.; Hagelstein, C.; Schoenberg, S.O.; Neff, K.W.; Zoellner, F.G.; Zahn, K.; Schaible, T.

    2016-01-01

    With a region of interest (ROI)-based approach 2-year-old children after congenital diaphragmatic hernia (CDH) show reduced MR lung perfusion values on the ipsilateral side compared to the contralateral. This study evaluates whether results can be reproduced by segmentation of whole-lung and whether there are differences between the ROI-based and whole-lung measurements. Using dynamic contrast-enhanced (DCE) MRI, pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) were quantified in 30 children after CDH repair. Quantification results of an ROI-based (six cylindrical ROIs generated of five adjacent slices per lung-side) and a whole-lung segmentation approach were compared. In both approaches PBF and PBV were significantly reduced on the ipsilateral side (p always <0.0001). In ipsilateral lungs, PBF of the ROI-based and the whole-lung segmentation-based approach was equal (p=0.50). In contralateral lungs, the ROI-based approach significantly overestimated PBF in comparison to the whole-lung segmentation approach by approximately 9.5 % (p=0.0013). MR lung perfusion in 2-year-old children after CDH is significantly reduced ipsilaterally. In the contralateral lung, the ROI-based approach significantly overestimates perfusion, which can be explained by exclusion of the most ventral parts of the lung. Therefore whole-lung segmentation should be preferred. (orig.)

  6. Inhibitory effect of high [Mg2+] on the vasopressin-stimulated hydroosmotic permeability of the isolated perfused cortical collecting duct

    Directory of Open Access Journals (Sweden)

    Falkenstein D.

    1999-01-01

    Full Text Available High magnesium concentration inhibits the effect of arginine vasopressin (AVP on smooth muscle contraction and platelet aggregation and also influences hepatocyte AVP receptor binding. The aim of this study was to determine the role of magnesium concentration [Mg2+] in AVP-stimulated water transport in the kidney collecting duct. The effect of low and high peritubular [Mg2+] on the AVP-stimulated osmotic water permeability coefficient (Pf was evaluated in the isolated perfused rabbit cortical collecting duct (CCD. Control tubules bathed and perfused with standard Ringer bicarbonate solution containing 1 mM Mg2+ presented a Pf of 223.9 ± 27.2 µm/s. When Mg2+ was not added to the bathing solution, an increase in the AVP-stimulated Pf to 363.1 ± 57.2 µm/s (P<0.05 was observed. An elevation of Mg2+ to 5 mM resulted in a decrease in Pf to 202.9 ± 12.6 µm/s (P<0.05. This decrease in the AVP-stimulated Pf at 5 mM Mg2+ persisted when the CCDs were returned to 1 mM Mg2+, Pf = 130.2 ± 20.3 µm/s, and was not normalized by the addition of 8-[4-chlorophenylthio]-adenosine 3',5'-cyclic monophosphate, a cAMP analogue, to the preparation. These data indicate that magnesium may play a modulatory role in the action of AVP on CCD osmotic water permeability, as observed in other tissues.

  7. Activation of rho is involved in the mechanism of hydrogen-peroxide-induced lung edema in isolated perfused rabbit lung.

    Science.gov (United States)

    Chiba, Y; Ishii, Y; Kitamura, S; Sugiyama, Y

    2001-09-01

    Acute lung injury is attributed primarily to increased vascular permeability caused by reactive oxygen species derived from neutrophils, such as hydrogen peroxide (H2O2). Increased permeability is accompanied by the contraction and cytoskeleton reorganization of endothelial cells, resulting in intercellular gap formation. The Rho family of Ras-like GTPases is implicated in the regulation of the cytoskeleton and cell contraction. We examined the role of Rho in H2O2-induced pulmonary edema with the use of isolated perfused rabbit lungs. To our knowledge, this is the first study to examine the role of Rho in increased vascular permeability induced by H2O2 in perfused lungs. Vascular permeability was evaluated on the basis of the capillary filtration coefficient (Kfc, ml/min/cm H2O/100 g). We found that H2O2 (300 microM) increased lung weight, Kfc, and pulmonary capillary pressure. These effects of H2O2 were abolished by treatment with Y-27632 (50 microM), an inhibitor of the Rho effector p160 ROCK. In contrast, the muscular relaxant papaverine inhibited the H2O2-induced rise in pulmonary capillary pressure, but did not suppress the increases in lung weight and Kfc. These findings indicate that H2O2 causes pulmonary edema by elevating hydrostatic pressure and increasing vascular permeability. Y-27632 inhibited the formation of pulmonary edema by blocking both of these H2O2-induced effects. Our results suggest that Rho-related pathways have a part in the mechanism of H2O2-induced pulmonary edema. Copyright 2001 Academic Press.

  8. Testing the biocompatibility of a glutathione-containing intra-ocular irrigation solution by using an isolated perfused bovine retina organ culture model - an alternative to animal testing.

    Science.gov (United States)

    Januschowski, Kai; Zhour, Ahmad; Lee, Albert; Maddani, Ramin; Mueller, Sebastien; Spitzer, Martin S; Schnichels, Sven; Schultheiss, Maximilian; Doycheva, Deshka; Bartz-Schmidt, Karl-Ulrich; Szurman, Peter

    2012-03-01

    The effects of a glutathione-containing intra-ocular irrigation solution, BSS Plus©, on retinal function and on the survival of ganglion cells in whole-mount retinal explants were studied. Evidence is provided that the perfused ex vivo bovine retina can serve as an alternative to in vivo animal testing. Isolated bovine retinas were prepared and perfused with an oxygen-saturated standard irrigation solution, and an electroretinogram was recorded to assess retinal function. After stable b-waves were detected, the isolated retinas were perfused with BSS Plus for 45 minutes. To investigate the effects of BSS Plus on photoreceptor function, 1mM aspartate was added to the irrigation solution in order to obtain a-waves, and the ERG trace was monitored for 75 minutes. For histological analysis, isolated whole retinal mounts were stored for 24 hours at 4°C, in the dark. The percentages of cell death in the retinal ganglion cell layer and in the outer and inner nuclear layers were estimated by using an ethidium homodimer-1 stain and the TUNEL assay. General swelling of the retina was examined with high-resolution optical coherence tomography. During perfusion with BSS Plus, no significant changes in a-wave and b-wave amplitudes were recorded. Retinas stored for 24 hours in BSS Plus showed a statistically significant smaller percentage (52.6%, standard deviation [SD] = 16.1%) of cell death in the retinal ganglion cell layer compared to the control group (69.6%, SD = 3.9, p = 0.0031). BSS Plus did not seem to affect short-term retinal function, and had a beneficial effect on the survival of retinal ganglion cells. This method for analysing the isolated perfused retina represents a valuable alternative for testing substances for their retinal biocompatibility and toxicity. 2012 FRAME.

  9. Glucose metabolism of isolated perfused rat hemidiaphragms stimulated via the phrenic nerve

    International Nuclear Information System (INIS)

    Bassett, D.J.P.; Bowen-Kelly, E.; Bierkamper, G.

    1986-01-01

    Few investigations using indirect electrical stimulation of diaphragm muscles have measured metabolic pathways involved in energy production. In this study, hemidiaphragm (HD) glucose catabolism was determined while resting and during stimulation with trains of either five (T5) or fifteen (T15) 50 Hz bursts per second. Tissues were perfused and bathed in HEPES buffer pH 7.4 equilibrated with 100% O 2 , and containing 11mM [U- 14 C][5- 3 H] D-glucose. Resting glucose catabolism via the Emden-Meyerhof pathway was indicated by a 3 H 2 O production rate of 1.45 +/- 0.07 μmol/h/HD (+/- S.E.M., n = 3), of which 47% was recovered as 14 C lactate. Following an initial decline in peak isometric tension from 100 g within the first 30 min, T5 and T15 stimulation gave constant tensions of 48 and 22 g during the next 60 min, respectively. These tensions were associated with linear rates of 3 H 2 O production of 2.93 +/- 0.41 and 2.84 +/- 0.25 μmol/h/HD (+/- S.E.M., n = 3). Since T5 and T15 stimulation had no significant effect on lactate formation from either exogenous or endogenous sources, the observed increased glycolytic rate was assumed to be associated with enhanced mitochondrial oxidation of glucose carbons to CO 2 . Increased oxidative catabolism of glucose could therefore be correlated with the increased energy demands of a stimulated diaphragm

  10. Glucose metabolism of isolated perfused rat hemidiaphragms stimulated via the phrenic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Bassett, D.J.P.; Bowen-Kelly, E.; Bierkamper, G.

    1986-03-01

    Few investigations using indirect electrical stimulation of diaphragm muscles have measured metabolic pathways involved in energy production. In this study, hemidiaphragm (HD) glucose catabolism was determined while resting and during stimulation with trains of either five (T5) or fifteen (T15) 50 Hz bursts per second. Tissues were perfused and bathed in HEPES buffer pH 7.4 equilibrated with 100% O/sub 2/, and containing 11mM (U-/sup 14/C)(5-/sup 3/H) D-glucose. Resting glucose catabolism via the Emden-Meyerhof pathway was indicated by a /sup 3/H/sub 2/O production rate of 1.45 +/- 0.07 ..mu..mol/h/HD (+/- S.E.M., n = 3), of which 47% was recovered as /sup 14/C lactate. Following an initial decline in peak isometric tension from 100 g within the first 30 min, T5 and T15 stimulation gave constant tensions of 48 and 22 g during the next 60 min, respectively. These tensions were associated with linear rates of /sup 3/H/sub 2/O production of 2.93 +/- 0.41 and 2.84 +/- 0.25 ..mu..mol/h/HD (+/- S.E.M., n = 3). Since T5 and T15 stimulation had no significant effect on lactate formation from either exogenous or endogenous sources, the observed increased glycolytic rate was assumed to be associated with enhanced mitochondrial oxidation of glucose carbons to CO/sub 2/. Increased oxidative catabolism of glucose could therefore be correlated with the increased energy demands of a stimulated diaphragm.

  11. Transport of plutonium across isolated segments of the intestine of neonatal swine

    International Nuclear Information System (INIS)

    Sullivan, M.F.; Gorham, L.S.

    1980-01-01

    Absorption of 239 Pu was measured in neonatal swine gavaged with either 239 Pu(IV) or 239 Pu(VI) niitrate 1 day after birth. When they were killed, 1 or 3 wk later, retention of the Pu(VI) was about 50% greater than retention of Pu(IV). Studies with isolated intestinal segments indicated no appreciable difference in 238 Pu transport by the duodenum, midgut or terminal ileum, and a substantial decrease in absorption between 2 and 19 days after birth

  12. Hepatic bilirubin uptake in the isolated perfused rat liver is not facilitated by albumin binding

    International Nuclear Information System (INIS)

    Stollman, Y.R.; Gaertner, U.; Theilmann, L.; Ohmi, N.; Wolkoff, A.W.

    1983-01-01

    Bilirubin uptake by the liver has kinetic characteristics which suggest carrier-mediation. Bilirubin is readily bound to albumin. A liver cell surface receptor for albumin has been postulated. The present study was designed to examine directly whether albumin facilitates the hepatic uptake of bilirubin and whether uptake of bilirubin depends on binding to albumin. Rat liver was perfused with a protein-free fluorocarbon medium, and single-pass uptake of 1, 10, or 200 nmol of [ 3 H]bilirubin was determined after injection as an equimolar complex with 125 I-albumin, with 125 I-ligandin, or free with only a [ 14 C]sucrose reference. Uptake of 10 nmol of [ 3 H]bilirubin was 67.5 +/- 3.7% of the dose when injected with 125 I-albumin, 67.4 +/- 6.5% when injected with 125 I-ligandin, and 74.9 +/- 2.4% when injected with [ 14 C]sucrose (P greater than 0.1). At 200 nmol, uptake fell to 46.4 +/- 3.1% ( 125 I-albumin) and 63.3 +/- 3.4% [( 14 C]sucrose) of injected [ 3 H]bilirubin (P less than 0.01), which suggests saturation of the uptake mechanism. When influx was quantitated by the model of Goresky, similar results were obtained. When [ 3 H]bilirubin was injected simultaneously with equimolar 125 I-albumin and a [ 14 C]sucrose reference, there was no delay in 125 I-albumin transit as compared with that of [ 14 C]sucrose. This suggested that the off-rate of albumin from a putative hepatocyte receptor would have to be very rapid, which is unusual for high affinity receptor-ligand interaction. There was no evidence for facilitation of bilirubin uptake by binding to albumin or for interaction of albumin with a liver cell surface receptor. These results suggest that the hepatic bilirubin uptake mechanism is one of high affinity which can extract bilirubin from circulating carriers such as albumin, ligandin, or fluorocarbon

  13. Effect of zinc source and picolinic acid on 65Zn uptake in an in vitro continuous-flow perfusion system for pig and poultry intestinal segments

    International Nuclear Information System (INIS)

    Hill, D.A.; Peo, E.R. Jr.; Lewis, A.J.

    1987-01-01

    Twenty weanling pigs and fourteen 9-wk-old broiler chickens were used in three continuous-flow in vitro perfusion experiments using noneverted intestinal sacs to 1) determine differences in 65 Zn absorption due to location within the intestinal tract, 2) evaluate 65 Zn uptake from ZnCl 2 and Zn-methionine (ZnMet) with or without added picolinic acid (PA) in pig intestinal sacs and 3) evaluate 65 Zn uptake from ZnCl 2 and ZnMet in chicken intestinal sacs. No differences in 65 Zn uptake due to gut segment position were observed in the pigs. A Zn source x PA interaction was observed for 65 Zn uptake into the pig gut tissue and for 65 Zn uptake to the serosal side of the gut sacs. Total 65 Zn absorption in the pig gut sacs from the two Zn sources was not different, but the addition of a 5 M ratio of PA to Zn depressed 65 Zn absorption. No differences were observed in total 65 Zn absorption or 65 Zn uptake in poultry gut sac tissue. There was, however, greater uptake of 65 Zn from ZnCl 2 to the serosal side of the sacs than from ZnMet. The data indicate that 65 Zn from ZnCl 2 and ZnMet is similar in total absorption and that the addition of PA depresses Zn uptake

  14. Isolated limb perfusion electrochemotherapy for the treatment of an advanced squamous cell carcinoma of the hoof in a mare

    Directory of Open Access Journals (Sweden)

    Enrico Pierluigi Spugnini

    2017-06-01

    Full Text Available A twenty-year-old female saddle horse was referred for evaluation of a seven month, non-healing erosive lesion of the right hind hoof with proliferation and bleeding of the underlying soft tissues. This lesion had been twice surgically treated as a canker but rapidly recurred. Histological examination of the second excision revealed a well-differentiated squamous cell carcinoma. At presentation, the horse was mildly depressed, lame and partially non-weight-bearing on the right hind leg, which exhibited a 10 x 10 cm erosive and proliferative lesion remodeling the hoof. After completing staging procedures, the lesion was approached with surgery and intraoperative electrochemotherapy (ECT administration of bleomycin in isolated limb perfusion. A second session of surgery and ECT was performed one month later, followed by three additional monthly sessions of ECT. During periodic recheck, the mare showed continuous improvement. One year after presentation, the mare was in complete remission and her gait markedly improved. ECT was well-tolerated and resulted in improved local control of a tumor in a challenging anatomical district.

  15. Percutaneous Isolated Hepatic Perfusion as a Treatment for Isolated Hepatic Metastases of Uveal Melanoma: Patient Outcome and Safety in a Multi-centre Study

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, Thomas J., E-mail: t.vogl@em.uni-frankfurt.de; Koch, Silvia A., E-mail: silvia.koch@web.de [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology (Germany); Lotz, Gösta, E-mail: goesta.lotz@kgu.de [University Hospital Frankfurt, Department of Anesthesiology, Intensive-Care Medicine and Pain Therapy (Germany); Gebauer, Bernhard, E-mail: bernhard.gebauer@charite.de [Universitätsmedizin Berlin, Department of Diagnostic and Interventional Radiology, Campus Charité Mitte (Germany); Willinek, Winfried, E-mail: w.willinek@bk-trier.de [Brüderkrankenhaus Trier, Department of Diagnostic and Interventional Radiology (Germany); Engelke, Christoph, E-mail: engelke@ekweende.de [Evangelisches Krankenhaus Göttingen-Weende gGmbH, Department of Diagnostic and Interventional Radiology (Germany); Brüning, Roland, E-mail: r.bruening@asklepios.com; Zeile, Martin, E-mail: m.zeile@asklepios.com [Asklepios Klinik Barmbek, Department of Diagnostic and Interventional Radiology (Germany); Wacker, Frank, E-mail: wacker.frank@mh-hannover.de [Medizinische Hochschule Hannover, Department of Diagnostic and Interventional Radiology (Germany); Vogel, Arndt, E-mail: vogel.arndt@mh-hannover.de [Medizinische Hochschule Hannover, Department of Gastroenterology, Hepatology and Endocrinology (Germany); Radeleff, Boris, E-mail: boris.radeleff@med.uni-heidelberg.de [Heidelberg University Hospital, Department of Diagnostic and Interventional Radiology (Germany); Scholtz, Jan-Erik, E-mail: janerikscholtz@gmail.com [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology (Germany)

    2017-06-15

    PurposePercutaneous isolated hepatic perfusion (PIHP) with Melphalan has been developed as a treatment for patients with isolated hepatic metastases of uveal melanoma. We discuss patient outcome and safety in a retrospective multi-centre study.Materials and MethodsBetween 2012 and 2016 18 patients with un-resectable isolated hepatic metastases of uveal melanoma received single or repeated PIHP with Melphalan (n = 35) at seven sites. Progression-free time, overall survival time (OS) and tumour response by means of RECIST 1.1 criteria were evaluated. Peri- and post-procedural adverse events (AE) were registered. Patients’ life quality was assessed using four-point scale questionnaires.ResultsOf 18 patients, initial PIHP treatment resulted in partial response (PR) in eight, stable disease (SD) in seven and progressive disease (PD) in three cases. Nine patients underwent second PIHP with PR in eight cases and PD in one case. Six patients were evaluated after third PIHP with PR in five patients and SD in one patient. Two patients received fourth PIHP with PD in both cases. Median OS was 9.6 months (range 1.6–41.0 months). Median progression-free survival time was 12.4 months (range 0.9–41.0 months) with 1-year survival of 44%. Most common post-procedural AE grade 3 and 4 were temporary leukopenia (n = 11) and thrombocytopenia (n = 8). Patients’ self-assessments showed good ratings for overall health and quality of life with only slight changes after PIHP, and a high degree of satisfaction with PIHP treatment.ConclusionPIHP with Melphalan proved to be a relatively safe, minimal-invasive and repeatable treatment for patients with non-resectable hepatic metastases of uveal melanoma.

  16. Percutaneous Isolated Hepatic Perfusion as a Treatment for Isolated Hepatic Metastases of Uveal Melanoma: Patient Outcome and Safety in a Multi-centre Study

    International Nuclear Information System (INIS)

    Vogl, Thomas J.; Koch, Silvia A.; Lotz, Gösta; Gebauer, Bernhard; Willinek, Winfried; Engelke, Christoph; Brüning, Roland; Zeile, Martin; Wacker, Frank; Vogel, Arndt; Radeleff, Boris; Scholtz, Jan-Erik

    2017-01-01

    PurposePercutaneous isolated hepatic perfusion (PIHP) with Melphalan has been developed as a treatment for patients with isolated hepatic metastases of uveal melanoma. We discuss patient outcome and safety in a retrospective multi-centre study.Materials and MethodsBetween 2012 and 2016 18 patients with un-resectable isolated hepatic metastases of uveal melanoma received single or repeated PIHP with Melphalan (n = 35) at seven sites. Progression-free time, overall survival time (OS) and tumour response by means of RECIST 1.1 criteria were evaluated. Peri- and post-procedural adverse events (AE) were registered. Patients’ life quality was assessed using four-point scale questionnaires.ResultsOf 18 patients, initial PIHP treatment resulted in partial response (PR) in eight, stable disease (SD) in seven and progressive disease (PD) in three cases. Nine patients underwent second PIHP with PR in eight cases and PD in one case. Six patients were evaluated after third PIHP with PR in five patients and SD in one patient. Two patients received fourth PIHP with PD in both cases. Median OS was 9.6 months (range 1.6–41.0 months). Median progression-free survival time was 12.4 months (range 0.9–41.0 months) with 1-year survival of 44%. Most common post-procedural AE grade 3 and 4 were temporary leukopenia (n = 11) and thrombocytopenia (n = 8). Patients’ self-assessments showed good ratings for overall health and quality of life with only slight changes after PIHP, and a high degree of satisfaction with PIHP treatment.ConclusionPIHP with Melphalan proved to be a relatively safe, minimal-invasive and repeatable treatment for patients with non-resectable hepatic metastases of uveal melanoma.

  17. Impaired coronary flow reserve is the most important marker of viable myocardium in the myocardial segment-based analysis of dual-isotope gated myocardial perfusion single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Lee, Won Woo; So, Young; Kim, Ki Bong; Lee, Dong Soo

    2014-01-01

    The aim of this study was to investigate the most robust predictor of myocardial viability among stress/rest reversibility (coronary flow reserve [CFR] impairment), 201 Tl perfusion status at rest, 201 Tl 24 hours redistribution and systolic wall thickening of 99m Tc-methoxyisobutylisonitrile using a dual isotope gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) who were re-vascularized with a coronary artery bypass graft (CABG) surgery. A total of 39 patients with CAD was enrolled (34 men and 5 women), aged between 36 and 72 years (mean 58 ± 8 standard in years) who underwent both pre- and 3 months post-CABG myocardial SPECT. We analyzed 17 myocardial segments per patient. Perfusion status and wall motion were semi-quantitatively evaluated using a 4-point grading system. Viable myocardium was defined as dysfunctional myocardium which showed wall motion improvement after CABG. The left ventricular ejection fraction (LVEF) significantly increased from 37.8 ± 9.0% to 45.5 ± 12.3% (p 201 Tl rest perfusion status (p = 0.024) were significant predictors of wall motion improvement. However, in multiple logistic regression analysis, stress/rest reversibility alone was a significant predictor for post-CABG wall motion improvement (p < 0.001). Stress/rest reversibility (impaired CFR) during dual-isotope gated myocardial perfusion SPECT was the single most important predictor of wall motion improvement after CABG.

  18. Effects of Scirpusin B, a polyphenol in passion fruit seeds, on the coronary circulation of the isolated perfused rat heart

    Directory of Open Access Journals (Sweden)

    Yutaka Matsumoto, Nozomi Gotoh, Shoko Sano, Kenkichi Sugiyama, Tatsuhiko Ito, Yohei Abe, Yumi Katano, Akira Ishihata

    2014-07-01

    Full Text Available Objective: Piceatannol, a polyphenol which is contained in passion fruits seed, is a derivative of resveratrol and is known to have antioxidant, anti-inflammatory and vasorelaxing activities. Passion fruits seed also contains a dimer of Piceatannol, Scirpusin B. The aim of this study was to investigate the effect of Scirpusin B on the coronary circulation of the isolated rat heart. Methods: Hearts were isolated from male Fischer 344 rats (5 – 6 months old, and perfused with modified Krebs-Henseleit solution aerated with 95% O2 and 5% CO2 (37 °C at constant pressure (75 cmH2O by Langendorff’s method. Piceatannol or Scirpusin B (10, 30 and 100 μM was injected as a bolus into the aortic cannula and coronary flow (CF was continuously measured by the electromagnetic flow meter. In some experiments, rat hearts were pretreated with L-NAME (an inhibitor of nitric oxide synthase or Diclofenac (an inhibitor of cyclooxygenase to reveal the possible involvement of nitric oxide (NO and vasodilating prostanoids in the effect of Scirpusin B. Results: Scirpusin B increased CF up to 108.2 % of the initial value, while Piceatannol did not increase CF. In addition; Scirpusin B increased CF concentration-dependently. Pretreatment with L-NAME or Diclofenac significantly attenuated the Scirpusin B-induced coronary vasodilatation. Scirpusin B did not change the heart rate either left ventricular pressure. Conclusion: This study shows that Scirpusin B could increase CF via production of NO and vasodilating prostanoids.

  19. Nuclear magnetic resonance of perfused tissue

    International Nuclear Information System (INIS)

    Harpen, M.D.; Allison, R.C.

    1986-01-01

    The effect of perfusion on the NMR signal observed in NMR imaging is studied in a phantom and in two isolated perfused canine lungs. It is observed that perfusion in tissue has little effect on longitudinal relaxation times. Transverse relaxation rates are observed to correlate linearly with rates of perfusion, in accordance with a model presented. (author)

  20. The Hepatoprotection Provided by Taurine and Glycine against Antineoplastic Drugs Induced Liver Injury in an Ex Vivo Model of Normothermic Recirculating Isolated Perfused Rat Liver

    Directory of Open Access Journals (Sweden)

    Reza Heidari

    2016-03-01

    Full Text Available Taurine (2-aminoethane sulfonic acid is a non-protein amino acid found in high concentration in different tissues. Glycine (Amino acetic acid is the simplest amino acid incorporated in the structure of proteins. Several investigations indicate the hepatoprotective properties of these amino acids. On the other hand, antineoplastic agents-induced serum transaminase elevation and liver injury is a clinical complication. The current investigation was designed to screen the possible hepatoprotective properties of taurine and glycine against antineoplastic drugs-induced hepatic injury in an ex vivo model of isolated perfused rat liver. Rat liver was perfused with different concentration (10 μM, 100 μM and 1000 μM of antineoplastic drugs (Mitoxantrone, Cyclophosphamide, Cisplatin, 5 Fluorouracil, Doxorubicin and Dacarbazine via portal vein. Taurine and glycine were administered to drug-treated livers and liver perfusate samples were collected for biochemical measurements (ALT, LDH, AST, and K+. Markers of oxidative stress (reactive oxygen species formation, lipid peroxidation, total antioxidant capacity and glutathione were also assessed in liver tissue. Antineoplastic drugs caused significant pathological changes in perfusate biochemistry. Furthermore, markers of oxidative stress were significantly elevated in drug treated livers. It was found that taurine (5 and 10 mM and glycine (5 and 10 mM administration significantly mitigated the biomarkers of liver injury and attenuated drug induced oxidative stress. Our data indicate that taurine and glycine supplementation might help as potential therapeutic options to encounter anticancer drugs-induced liver injury.

  1. A semi-automated measuring system of brain diffusion and perfusion magnetic resonance imaging abnormalities in patients with multiple sclerosis based on the integration of coregistration and tissue segmentation procedures

    International Nuclear Information System (INIS)

    Revenaz, Alfredo; Ruggeri, Massimiliano; Laganà, Marcella; Bergsland, Niels; Groppo, Elisabetta; Rovaris, Marco; Fainardi, Enrico

    2016-01-01

    Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) abnormalities in patients with multiple sclerosis (MS) are currently measured by a complex combination of separate procedures. Therefore, the purpose of this study was to provide a reliable method for reducing analysis complexity and obtaining reproducible results. We implemented a semi-automated measuring system in which different well-known software components for magnetic resonance imaging (MRI) analysis are integrated to obtain reliable measurements of DWI and PWI disturbances in MS. We generated the Diffusion/Perfusion Project (DPP) Suite, in which a series of external software programs are managed and harmonically and hierarchically incorporated by in-house developed Matlab software to perform the following processes: 1) image pre-processing, including imaging data anonymization and conversion from DICOM to Nifti format; 2) co-registration of 2D and 3D non-enhanced and Gd-enhanced T1-weighted images in fluid-attenuated inversion recovery (FLAIR) space; 3) lesion segmentation and classification, in which FLAIR lesions are at first segmented and then categorized according to their presumed evolution; 4) co-registration of segmented FLAIR lesion in T1 space to obtain the FLAIR lesion mask in the T1 space; 5) normal appearing tissue segmentation, in which T1 lesion mask is used to segment basal ganglia/thalami, normal appearing grey matter (NAGM) and normal appearing white matter (NAWM); 6) DWI and PWI map generation; 7) co-registration of basal ganglia/thalami, NAGM, NAWM, DWI and PWI maps in previously segmented FLAIR space; 8) data analysis. All these steps are automatic, except for lesion segmentation and classification. We developed a promising method to limit misclassifications and user errors, providing clinical researchers with a practical and reproducible tool to measure DWI and PWI changes in MS

  2. Protective effect of taurine on the light-induced disruption of isolated frog rod outer segments

    International Nuclear Information System (INIS)

    Pasantes-Morales, H.; Ademe, R.M.; Quesada, O.

    1981-01-01

    Isolated frog rod outer segments (ROS) incubated in a Krebs-bicarbonate medium, and illuminated for 2 h, show a profound alteration in their structure. This is characterized by distention of discs, vesiculation, and a marked swelling. The light-induced ROS disruption requires the presence of bicarbonate and sodium chloride. Replacement of bicarbonate by TRIS or HEPES protects ROS structure. Also, substitution of sodium chloride by sucrose or choline chloride maintains unaltered the ROS structure. Deletion of calcium, magnesium, or phosphate does not modify the effect produced by illumination. An increased accumulation of labeled bicarbonate and tritiated water is observed in illuminated ROS, as compared with controls in the dark. The presence of taurine, GABA, or glycine, at concentrations of 5-25 mM, effectively counteracts the light-induced ROS disruption. Taurine (25 mM) reduces labeled bicarbonate and tritiated water levels to those observed in the dark incubated ROS

  3. Study of therapeutic and histopathologic effects of corn silk\\'s aqueous and metanolic extract against dosage induced by MDMA in isolated rat liver perfusion system

    Directory of Open Access Journals (Sweden)

    Mohammad Karami

    2014-04-01

    Full Text Available Background: Corn silk is obtained from the plant Zea mays L. A traditional herbal medicine is in China. This has been used in many parts of the world to treat edema, kidney infections, gout, kidney stones, kidney diseases and prostate. Reports of the antioxidant effects of this material are available. Although little scientific resources are available to confirm its efficacy. In this study we tried to find out the antioxidant effect and preventing of hepatotoxicity effect of Corn silk with IRLP Isolated Rat Liver Perfusion system. Material and Methods: The aqueous and methanol extracts of dried Corn silk doses (10, 20, 40, 50 and 100 mg/kg was used. Albino Rats weighing 220-180 g were examined after anesthesia by diethyl ether, the abdominal cavity of the animal T-shaped pattern excision in the abdomen and around is opened.Then portal vein connected to the perfusion flow by using small scalp Vienna (No. 23 into the portal vein. After reaching perfusion flow rate to 20 ml per minute, extracts and fraction with above doses were added to perfusion buffer. Fluid outflows from the inferior vena cava, were collected for measurement of glutathione. One sample of the liver was removed for glutathione measurement and one sample was maintained in 10% formalin for histopathological examination. Differences between group means were estimated using oneway ANOVA followed by Duncan’s multiple range test. Results: The results showed that reduced glutathione level increased significantly by aqueous and methanol extract in comparison with controls. Pathology results confirmed that by increasing dose of extracts, severity of tissue damage (hemorrhage, fibrosis, and necrosis is reduced. In samples taken at intervals of 120 minutes, changes in the glutathione of case groups showed significant difference in comparison with the control group (p<0.01. Conclusion: Findings indicated that aqueous and methanolic extracts of corn fiber, reduced hepatic damages of MDMA

  4. Effect of phenobarbital pretreatment on benzene biotransformation in the rat. Pt. 2. 9. 000 g supernatant and isolated perfused liver versus living rat

    Energy Technology Data Exchange (ETDEWEB)

    Gut, I.; Hatle, K.; Zizkova, L.

    1981-03-01

    Factors responsible for different quantitative effect of phenobarbital (PB) pretreatment on benzene metabolism to phenol in vivo and in vitro were studied in male Wistar rats. A more than 4-fold increase of benzene metabolism was observed with 9,000 g supernatant of liver homogenate, 2.8- to 4-fold increase with isolated perfused liver; phenol formation in vivo after oral benzene was increased by PB 2-fold, but only shortly following benzene administration and the enhancement rapidly diminished to 1.15-fold increase in the total excreted phenol. Benzene concentrations in 9,000 g supernatant incubations were 2 mM, those with isolated perfused livers were up to 4 mM, but those in blood in vivo were below 0.3 mM; the effect of PB induction in vivo disappeared along with decreasing benzene and increasing phenol blood concentrations which surpassed benzene 2-3 h after oral benzene administration. The effect of benzene concentration on the manifestation of PB induction is also supported by almost a 2-fold increased phenol formation in PB rats over controls in vivo after repeated administration of benzene. The elimination of radioactive metabolites of orally administered benzene-/sup 14/C, in urine was markedly inhibited by intraperitoneal administration of phenol, but not by pyrocatechol, resorcinol or hydroquinol suggesting that phenol might inhibit benzene metabolism in vivo especially when its concentration exceeds that of benzene.

  5. The VGF-Derived Neuropeptide TLQP-21 Shows No Impact on Hormone Secretion in the Isolated Perfused Rat Pancreas

    DEFF Research Database (Denmark)

    Christiansen, Charlotte Bayer; Svendsen, B; Holst, Jens Juul

    2015-01-01

    investigated the impact of TLQP-21 on insulin, glucagon, and somatostatin secretion in the perfused rat pancreas. We found that administration of 5 and 50 nM TLQP-21 had no impact on pancreatic hormone secretion at 3.5 or 8 mM glucose levels. Increasing TLQP-21 (200 nM) and glucose concentration (3.5 and 16 m...

  6. Induction of chagasic-like arrhythmias in the isolated beating hearts of healthy rats perfused with Trypanosoma cruzi-conditioned medium

    Directory of Open Access Journals (Sweden)

    H. Rodriguez-Angulo

    2013-01-01

    Full Text Available Chagas' myocardiopathy, caused by the intracellular protozoan Trypanosoma cruzi, is characterized by microvascular alterations, heart failure and arrhythmias. Ischemia and arrythmogenesis have been attributed to proteins shed by the parasite, although this has not been fully demonstrated. The aim of the present investigation was to study the effect of substances shed by T. cruzi on ischemia/reperfusion-induced arrhythmias. We performed a triple ischemia-reperfusion (I/R protocol whereby the isolated beating rat hearts were perfused with either Vero-control or Vero T. cruzi-infected conditioned medium during the different stages of ischemia and subsequently reperfused with Tyrode's solution. ECG and heart rate were recorded during the entire experiment. We observed that triple I/R-induced bradycardia was associated with the generation of auricular-ventricular blockade during ischemia and non-sustained nodal and ventricular tachycardia during reperfusion. Interestingly, perfusion with Vero-infected medium produced a delay in the reperfusion-induced recovery of heart rate, increased the frequency of tachycardic events and induced ventricular fibrillation. These results suggest that the presence of parasite-shed substances in conditioned media enhances the arrhythmogenic effects that occur during the I/R protocol.

  7. Effect of phenobarbital on 131I-bromosulfophthalein metabolism of isolated perfused liver of rats with alpha-naphthylisothiocyanate-induced chloestasis

    International Nuclear Information System (INIS)

    Tapalaga, D.; Suciu, A.; Schvartz, M.; Duca, S.

    1979-01-01

    In order to establish whether the increased bromosulfophthalein (BSP) secretion in the bile following phenobarbital administration is the consequence of change in the bile output or of the enzymatic induction, the dynamics of the elimination of 131 I-BSP was studied in animals treated with alpha-naphthylisothiocyanate (ANIT) and pehnobarbital in the conditions of isolated perfused liver. At the same time the levels of the conjugation enzyme of BSP were also determined. It was noted that after phenobarbital the biliary elimination of 131 I-BSP is in correlation with the important increase of the output; in the animals treated with ANIT, on the other hand, the biliary excretion of BSP is minimal. The biliary elimination is directly proportional to the increase of the bile output and reflects the changes found in the perfusate. Our findings allow us to assume that the increased biliary BSP excretion is the consequence of the increase of the bile output and in a smaller extent the result of the stimulation of the BSP, conjugation with glutathion. (author)

  8. Automated segmentation and isolation of touching cell nuclei in cytopathology smear images of pleural effusion using distance transform watershed method

    Science.gov (United States)

    Win, Khin Yadanar; Choomchuay, Somsak; Hamamoto, Kazuhiko

    2017-06-01

    The automated segmentation of cell nuclei is an essential stage in the quantitative image analysis of cell nuclei extracted from smear cytology images of pleural fluid. Cell nuclei can indicate cancer as the characteristics of cell nuclei are associated with cells proliferation and malignancy in term of size, shape and the stained color. Nevertheless, automatic nuclei segmentation has remained challenging due to the artifacts caused by slide preparation, nuclei heterogeneity such as the poor contrast, inconsistent stained color, the cells variation, and cells overlapping. In this paper, we proposed a watershed-based method that is capable to segment the nuclei of the variety of cells from cytology pleural fluid smear images. Firstly, the original image is preprocessed by converting into the grayscale image and enhancing by adjusting and equalizing the intensity using histogram equalization. Next, the cell nuclei are segmented using OTSU thresholding as the binary image. The undesirable artifacts are eliminated using morphological operations. Finally, the distance transform based watershed method is applied to isolate the touching and overlapping cell nuclei. The proposed method is tested with 25 Papanicolaou (Pap) stained pleural fluid images. The accuracy of our proposed method is 92%. The method is relatively simple, and the results are very promising.

  9. Pomegranate Extract Enhances Endothelium-Dependent Coronary Relaxation in Isolated Perfused Hearts from Spontaneously Hypertensive Ovariectomized Rats

    Science.gov (United States)

    Delgado, Nathalie T. B.; Rouver, Wender do N.; Freitas-Lima, Leandro C.; de Paula, Tiago D.-C.; Duarte, Andressa; Silva, Josiane F.; Lemos, Virgínia S.; Santos, Alexandre M. C.; Mauad, Helder; Santos, Roger L.; Moysés, Margareth R.

    2017-01-01

    Decline in estrogen levels promotes endothelial dysfunction and, consequently, the most prevalent cardiovascular diseases in menopausal women. The use of natural therapies such as pomegranate can change these results. Pomegranate [Punica granatum L. (Punicaceae)] is widely used as a phytotherapeutic agent worldwide, including in Brazil. We hypothesized that treatment with pomegranate hydroalcoholic extract (PHE) would improve coronary vascular reactivity and cardiovascular parameters. At the beginning of treatment, spontaneously hypertensive female rats were divided into Sham and ovariectomized (OVX) groups, which received pomegranate extract (PHE) (250 mg/kg) or filtered water (V) for 30 days by gavage. Systolic blood pressure was measured by tail plethysmography. After euthanasia, the heart was removed and coronary vascular reactivity was assessed by Langendorff retrograde perfusion technique. A dose-response curve for bradykinin was performed, followed by L-NAME inhibition. The protein expression of p-eNOS Ser1177, p-eNOS Thr495, total eNOS, p-AKT Ser473, total AKT, SOD-2, and catalase was quantified by Western blotting. The detection of coronary superoxide was performed using the protocol of dihydroethidium (DHE) staining Plasma nitrite measurement was analyzed by Griess method. Systolic blood pressure increased in both Sham-V and OVX-V groups, whereas it was reduced after treatment in Sham-PHE and OVX-PHE groups. The baseline coronary perfusion pressure was reduced in the Sham-PHE group. The relaxation was significantly higher in the treated group, and L-NAME attenuated the relaxation in all groups. The treatment has not changed p-eNOS (Ser1177), total eNOS, p-AKT (Ser473) and total AKT in any groups. However, in Sham and OVX group the treatment reduced the p-eNOS (Thr495) and SOD-2. The ovariectomy promoted an increasing in the superoxide anion levels and the treatment was able to prevent this elevation and reducing oxidative stress. Moreover, the treatment

  10. Renal perfusion scintiscan

    Science.gov (United States)

    ... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

  11. 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)

  12. A Novel WT1 Gene Mutation in a Three-Generation Family with Progressive Isolated Focal Segmental Glomerulosclerosis

    Science.gov (United States)

    Caridi, Gianluca; Malaventura, Cristina; Dagnino, Monica; Leonardi, Emanuela; Artifoni, Lina; Ghiggeri, Gian Marco; Tosatto, Silvio C.E.; Murer, Luisa

    2010-01-01

    Background and objectives: Wilms tumor-suppressor gene-1 (WT1) plays a key role in kidney development and function. WT1 mutations usually occur in exons 8 and 9 and are associated with Denys-Drash, or in intron 9 and are associated with Frasier syndrome. However, overlapping clinical and molecular features have been reported. Few familial cases have been described, with intrafamilial variability. Sporadic cases of WT1 mutations in isolated diffuse mesangial sclerosis or focal segmental glomerulosclerosis have also been reported. Design, setting, participants, & measurements: Molecular analysis of WT1 exons 8 and 9 was carried out in five members on three generations of a family with late-onset isolated proteinuria. The effect of the detected amino acid substitution on WT1 protein's structure was studied by bioinformatics tools. Results: Three family members reached end-stage renal disease in full adulthood. None had genital abnormalities or Wilms tumor. Histologic analysis in two subjects revealed focal segmental glomerulosclerosis. The novel sequence variant c.1208G>A in WT1 exon 9 was identified in all of the affected members of the family. Conclusions: The lack of Wilms tumor or other related phenotypes suggests the expansion of WT1 gene analysis in patients with focal segmental glomerulosclerosis, regardless of age or presence of typical Denys-Drash or Frasier syndrome clinical features. Structural analysis of the mutated protein revealed that the mutation hampers zinc finger-DNA interactions, impairing target gene transcription. This finding opens up new issues about WT1 function in the maintenance of the complex gene network that regulates normal podocyte function. PMID:20150449

  13. Development of an Assay Based on the Effects of PGBx on the Isolated Perfused Rat Heart and Rat Skeletal Muscle.

    Science.gov (United States)

    1980-09-01

    had no effect on discphe- nol induced alterations in spontaneous heart rate, but did appear to prevent the increase in coronary flow caused by...Phosphorylase a i -24 activity was also the same in each of the groups examined (Table 2-4). DISCUSSION The ability of PGBx to prevent 2,4-dinitrophenol-induced...euthyroid and hyperthyroid rats. Eur. J. Pharmac. 19, 12-17. Aronson, C. E. and Serlick, E. R. (1977a) Effects of chlorpromazine on the isolated

  14. Restricted diffusion of DNA segments within the isolated Escherichia coli nucleoid.

    NARCIS (Netherlands)

    Cunha, S.; Woldringh, C.L.; Odijk, T.

    2005-01-01

    To study the dynamics and organization of the DNA within isolated Escherichia coli nucleoids, we track the movement of a specific DNA region. Labeling of such a region is achieved using the Lac-O/Lac-I system. The Lac repressor-GFP fusion protein binds to the DNA section where tandem repeats of the

  15. Vascular, but not luminal, activation of FFAR1 (GPR40) stimulates GLP-1 secretion from isolated perfused rat small intestine

    DEFF Research Database (Denmark)

    Christensen, Louise Wulff; Kuhre, Rune Ehrenreich; Janus, Charlotte

    2015-01-01

    -protein-cou- pled receptor, FFAR1 (previously GPR40), expressed on L cells and activated by long-chain fatty acids (LCFAs) is a potential target. A link between FFAR1 activation and GLP-1 secretion has been demonstrated in cellular models and small-molecule FFAR1 agonists have been developed. In this study, we exam......- ined the effect of FFAR1 activation on GLP-1 secretion using isolated, per- fused small intestines from rats, a physiologically relevant model allowing distinction between direct and indirect effects of FFAR1 activation. The endogenous FFAR1 ligand, linoleic acid (LA), and four synthetic FFAR1 ago...

  16. Going skin deep: A direct comparison of penetration potential of lipid-based nanovesicles on the isolated perfused human skin flap model.

    Science.gov (United States)

    Ternullo, Selenia; de Weerd, Louis; Holsæter, Ann Mari; Flaten, Gøril Eide; Škalko-Basnet, Nataša

    2017-12-01

    Phospholipid-based nanocarriers are attractive drug carriers for improved local skin therapy. In the present study, the recently developed isolated perfused human skin flap (IPHSF) model was used to directly compare the skin penetration enhancing potential of the three commonly used nanocarriers, namely conventional liposomes (CLs), deformable liposomes (DLs) and solid lipid nanoparticles (SLNs). Two fluorescent markers, calcein (hydrophilic) or rhodamine (lipophilic), were incorporated individually in the three nanosystems. The nanocarrier size ranged between 200 and 300nm; the surface charge and entrapment efficiency for both markers were dependent on the lipid composition and the employed surfactant. Both carrier-associated markers could not penetrate the full thickness human skin, confirming their suitability for dermal drug delivery. CLs exhibited higher retention of both markers on the skin surface compared to DLs and SLNs, indicating a depo formation. DLs and SLNs enabled the deeper penetration of the two markers into the skin layers. In vitro and ex vivo skin penetration studies performed on the cellophane membrane and full thickness pig/human skin, respectively, confirmed the findings. In conclusion, efficient dermal drug delivery can be achieved by optimization of a lipid nanocarrier on the suitable skin-mimicking model to assure system's accumulation in the targeted skin layer. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Some processes of energy saving and expenditure occurring during ethanol perfusion in the isolated liver of fed rats; a Nuclear Magnetic Resonance study.

    Directory of Open Access Journals (Sweden)

    Gin Henri

    2004-03-01

    Full Text Available Abstract Background In the isolated liver of fed rats, a 10 mM ethanol perfusion rapidly induced a rapid 25% decrease in the total ATP content, the new steady state resulting from both synthesis and consumption. The in situ rate of mitochondrial ATP synthesis without activation of the respiration was increased by 27%, implying an increased energy demand. An attempt to identify the ethanol-induced ATP-consuming pathways was performed using 31P and 13C Nuclear Magnetic Resonance. Results Ethanol (i transiently increased sn-glycerol-3-phosphate formation whereas glycogenolysis was continuously maintained; (ii decreased the glycolytic ATP supply and (iii diminished the intracellular pH in a dose-dependent manner in a slight extend. Although the cytosolic oxidation of ethanol largely generated H+ (and NADH, intracellular pHi was maintained by (i the large and passive excretion of cellular acetic acid arising from ethanol oxidation (evidenced by exogenous acetate administration, without energetic cost or (ii proton extrusion via the Na+-HCO3- symport (implying the indirect activation of the Na+-K+-ATPase pump and thus an energy use, demonstrated during the addition of their specific inhibitors SITS and ouabaïn, respectively. Conclusion Various cellular mechanisms diminish the cytosolic concentration of H+ and NADH produced by ethanol oxidation, such as (i the large but transient contribution of the dihydroxyacetone phosphate / sn-glycerol-3-phosphate shuttle between cytosol and mitochondria, mainly implicated in the redox state and (ii the major participation of acetic acid in passive proton extrusion out of the cell. These processes are not ATP-consuming and the latter is a cellular way to save some energy. Their starting in conjunction with the increase in mitochondrial ATP synthesis in ethanol-perfused whole liver was however insufficient to alleviate either the inhibition of glycolytic ATP synthesis and/or the implication of Na+-HCO3- symport and

  18. Extracts from the Mongolian traditional medicinal plants Dianthus versicolorFisch. and Lilium pumilum Delile stimulate bile flow in an isolated perfused rat liver model.

    Science.gov (United States)

    Obmann, Astrid; Tsendayush, Damba; Thalhammer, Theresia; Zehl, Martin; Vo, Thanh Phuong Nha; Purevsuren, Sodnomtseren; Natsagdorj, Damdinsuren; Narantuya, Samdan; Kletter, Christa; Glasl, Sabine

    2010-10-05

    Dianthus versicolor (Caryophyllaceae) and Lilium pumilum (Liliaceae) are two medicinal plants used in traditional Mongolian medicine to treat hepatic and gastrointestinal disorders. In this study aqueous (AE) and methanolic (ME) extracts of Dianthus versicolor and Lilium pumilum were investigated for their influence on the bile flow. The aqueous extracts of both plants were tested in absence and presence of 10 μM taurocholic acid at three different concentrations (100, 250, and 500 mg/L). The aqueous extract of Dianthus versicolor was further purified in order to locate the active principles. Two resulting fractions, one enriched in flavonoids and the other in sugars, were investigated for their influence on the bile flow in absence of taurocholic acid at 10, 20, and 40 mg/L. The aqueous extracts of both plants were analysed qualitatively by LC-MS(n) and quantitatively by UV-spectrophotometry. The bile flow experiments were performed in the isolated perfused rat liver. The compounds were identified by LC-DAD-MS(n) and TLC using references. The UV-spectrophotometric analysis was based on the monograph "Passiflorae herba" of the European Pharmacopoeia, and the total flavonoid contents were calculated and expressed as vitexin. AE and ME of both plants increased the bile flow dose-dependently (between 9% and 30%), and no hepatotoxic effect was seen even during longer perfusions. Stimulation of bile secretion was comparable in the presence and in the absence of taurocholic acid. The flavonoid fraction of Dianthus versicolor increased the bile flow by 18% (pDianthus versicolor AE (total flavonoid content 1.78%) revealed the presence of the isovitexin derivative saponarin. In the AE of Lilium pumilum (total flavonoid content 1.04%) the flavonoids rutoside, kaempferol-3-O-rutinoside, and isorhamnetin-3-O-rutinoside were detected. The results show that choleresis under extract application is due to a stimulation of the bile-salt-independent bile flow which might be caused

  19. Expression of multidrug resistance genes MVP, MDR1, and MRP1 determined sequentially before, during, and after hyperthermic isolated limb perfusion of soft tissue sarcoma and melanoma patients.

    Science.gov (United States)

    Stein, Ulrike; Jürchott, Karsten; Schläfke, Matthias; Hohenberger, Peter

    2002-08-01

    Isolated, hyperthermic limb perfusion (ILP) with recombinant human tumor necrosis factor alpha and melphalan is a highly effective treatment for advanced soft tissue sarcoma (STS) and locoregional metastatic malignant melanoma. Multidrug resistance (MDR)-associated genes are known to be inducible by heat and drugs; expression levels of the major vault protein (MVP), MDR1, and MDR-associated protein 1 (MRP1) were determined sequentially before, during, and after ILP of patients. Twenty-one STS or malignant melanoma patients were treated by ILP. Tumor tissue temperatures were recorded continuously and ranged from 33.4 degrees C initially to peak values of 40.4 degrees C during ILP. Serial true-cut biopsy specimens from tumor tissues were routinely microdissected. Expression analyses for MDR genes were performed by real-time reverse transcriptase polymerase chain reaction and immunohistochemistry. In 83% of the patients, MVP expression was induced during hyperthermic ILP. MVP-mRNA inductions often paralleled the increase in temperature during ILP. Increased MVP protein expressions either were observed simultaneously with the MVP-mRNA induction or were delayed until after the induction at the transcriptional level. Inductions of MDR1 and MRP1 were observed in only 13% and 27% of the specimens analyzed. Temperatures and drugs applied preferentially led to an induction of MVP and were not sufficient to induce MDR1 and MRP1 in the majority of tumors. This study is the first to analyze the expression of MDR-associated genes sequentially during ILP of patients and demonstrates that treatment might lead to increased levels of MVP, whereas enhanced levels of MDR1 and MRP1 remain rare events.

  20. The kinetics of {beta}-methyl-substituted labelled fatty acids in ischaemic myocardium: an analysis in man and with a blood-perfused isolated heart model

    Energy Technology Data Exchange (ETDEWEB)

    Marie, P.Y.; Ayalew, A.; Hassan, N.; Olivier, P.; Karcher, G.; Bertrand, A. [Dept. of Nuclear Medicine, UPRES EA, Nancy (France); Menu, P. [Dept. of Hematology and Physiology, University Henri Poincare, Nancy (France); Angioi, M.; Mertes, P.M.; Danchin, N. [Dept. of Cardiology, UPRES EA, Nancy (France); Fagret, D. [Dept. of Nuclear Medicine, Grenoble (France); Pasqualini, R. [CIS Bio International, Gif-sur-Yvette (France)

    1999-05-01

    {beta}-Methyl-substituted free fatty acids (FFAs) have been developed for myocardial single-photon emission tomography (SPET) imaging, but little is known about their kinetics in ischaemic conditions. The aim of this study was to determine the changes in the myocardial kinetics of a {beta}-methyl-branched FFA, [{sup 123}I]16-iodo-3-methyl-hexadecanoic acid (MIHA), under ischaemic conditions. The kinetics of MIHA were analysed: (a) using a blood-perfused isolated heart model subjected to moderate ischaemia (50% flow reduction) and (b) in patients who had an exercise thallium-201 SPET defect corresponding to either necrotic (n = 13) or chronically ischaemic and viable (n = 15) myocardium, and who underwent two consecutive SPET studies after MIHA injection. In animals, the myocardial early retention fraction of MIHA, but not its clearance rate, was dependent on coronary flow, the early retention fraction being higher in ischaemic than in normoxic conditions (0.24{+-}0.10 vs 0.14{+-}0.04, P = 0.004). In the patient SPET studies, the uptake of MIHA calculated in ischaemic and viable areas (G1: 74%{+-}9% of maximal left ventricular value) was different from that calculated in necrotic (G2: 59%{+-}7%, P<0.001) or normal (G3: 88{+-}6%, P<0.001) areas. By contrast, MIHA-clearance calculated between the two consecutive SPET studies was not different in G1, G2 and G3. Unlike in the case of other FFAs, the myocardial clearance of MIHA is not decreased by ischaemia. However, the early retention of MIHA is increased in the case of a moderate reduction in coronary flow, a property which might help in the detection of viability in chronically ischaemic myocardium. (orig.) With 5 figs., 3 tabs., 44 refs.

  1. Randomized multicenter trial of hyperthermic isolated limb perfusion with melphalan alone compared with melphalan plus tumor necrosis factor: American College of Surgeons Oncology Group Trial Z0020.

    Science.gov (United States)

    Cornett, Wendy R; McCall, Linda M; Petersen, Rebecca P; Ross, Merrick I; Briele, Henry A; Noyes, R Dirk; Sussman, Jeffrey J; Kraybill, William G; Kane, John M; Alexander, H Richard; Lee, Jeffrey E; Mansfield, Paul F; Pingpank, James F; Winchester, David J; White, Richard L; Chadaram, Vijaya; Herndon, James E; Fraker, Douglas L; Tyler, Douglas S

    2006-09-01

    To determine in a randomized prospective multi-institutional trial whether the addition of tumor necrosis factor alpha (TNF-alpha) to a melphalan-based hyperthermic isolated limb perfusion (HILP) treatment would improve the complete response rate for locally advanced extremity melanoma. Patients with locally advanced extremity melanoma were randomly assigned to receive melphalan or melphalan plus TNF-alpha during standard HILP. Patient randomization was stratified according to disease/treatment status and regional nodal disease status. The intervention was completed in 124 patients of the 133 enrolled. Grade 4 adverse events were observed in 14 (12%) of 129 patients, with three (4%) of 64 in the melphalan-alone arm and 11 (16%) of 65 in the melphalan-plus-TNF-alpha arm (P = .0436). There were two toxicity-related lower extremity amputations in the melphalan-plus-TNF-alpha arm, and one disease progression-related upper extremity amputation in the melphalan-alone arm. There was no treatment-related mortality in either arm of the study. One hundred sixteen patients were assessable at 3 months postoperatively. Sixty-four percent of patients (36 of 58) in the melphalan-alone arm and 69% of patients (40 of 58) in the melphalan-plus-TNF-alpha arm showed a response to treatment at 3 months, with a complete response rate of 25% (14 of 58 patients) in the melphalan-alone arm and 26% (15 of 58 patients) in the melphalan-plus-TNF-alpha arm (P = .435 and P = .890, respectively). In locally advanced extremity melanoma treated with HILP, the addition of TNF-alpha to melphalan did not demonstrate a significant enhancement of short-term response rates over melphalan alone by the 3-month follow-up, and TNF-alpha plus melphalan was associated with a higher complication rate.

  2. Cirurgia do arco aórtico com perfusão cerebral bilateral pelo isolamento do tronco braquiocefálico e da artéria carótida esquerda Aortic arch surgery with bilateral cerebral perfusion by isolation of brachiocephalic trunk and left carotid artery

    Directory of Open Access Journals (Sweden)

    Valdo José Carreira

    2008-03-01

    Full Text Available OBJETIVO: Estudar os resultados da técnica descrita por Carreira et al. com utilização de perfusão cerebral seletiva bilateral (PCSAB pelo isolamento do tronco braquiocefálico e artéria carótida esquerda. MÉTODOS: Quinze pacientes foram operados consecutivamente entre de junho de 2005 e setembro de 2007. Os dados foram analisados por programa informatizado Epi Info e significância estatística com p0,05. CONCLUSÃO: A técnica de PCSAB é reprodutível e apresenta resultados semelhantes aos da literatura mundial. A excelente evolução neurológica e o fácil controle de sangramentos nas linhas de sutura podem ter contribuído com os resultados obtidos.OBJECTIVE: To evaluate the results of a technique described by Carreira et al. using bilateral antegrade selective cerebral perfusion by isolating the brachiocephalic trunk and the left carotid artery. METHODS: Fifteen patients were operated between June 2005 and September 2007. Data analysis were performed using Epi Info and statistical significance was set at p0.05. CONCLUSION: The technique of bilateral selective cerebral perfusion described by Carreira et al. can be performed by others and presents similar results to the international literature. The excellent neurological outcome and easy bleeding control on surgical sutures lines are the major advantages of this new procedure.

  3. Computerized analysis of brain perfusion parameter images

    International Nuclear Information System (INIS)

    Turowski, B.; Haenggi, D.; Wittsack, H.J.; Beck, A.; Aurich, V.

    2007-01-01

    Purpose: The development of a computerized method which allows a direct quantitative comparison of perfusion parameters. The display should allow a clear direct comparison of brain perfusion parameters in different vascular territories and over the course of time. The analysis is intended to be the basis for further evaluation of cerebral vasospasm after subarachnoid hemorrhage (SAH). The method should permit early diagnosis of cerebral vasospasm. Materials and Methods: The Angiotux 2D-ECCET software was developed with a close cooperation between computer scientists and clinicians. Starting from parameter images of brain perfusion, the cortex was marked, segmented and assigned to definite vascular territories. The underlying values were averages for each segment and were displayed in a graph. If a follow-up was available, the mean values of the perfusion parameters were displayed in relation to time. The method was developed under consideration of CT perfusion values but is applicable for other methods of perfusion imaging. Results: Computerized analysis of brain perfusion parameter images allows an immediate comparison of these parameters and follow-up of mean values in a clear and concise manner. Values are related to definite vascular territories. The tabular output facilitates further statistic evaluations. The computerized analysis is precisely reproducible, i. e., repetitions result in exactly the same output. (orig.)

  4. Increased sinusoidal volume and solute extraction during retrograde liver perfusion

    International Nuclear Information System (INIS)

    Bass, N.M.; Manning, J.A.; Weisiger, R.A.

    1989-01-01

    Retrograde isolated liver perfusion has been used to probe acinar functional heterogeneity, but the hemodynamic effects of backward flow have not been characterized. In this study, extraction of a long-chain fatty acid derivative, 12-N-methyl-7-nitrobenzo-2-oxa-1,3-diazol-amino stearate (12-NBDS), was greater during retrograde than during anterograde perfusion of isolated rat liver. To determine whether hemodynamic differences between anterograde and retrograde perfused livers could account for this finding, the hepatic extracellular space was measured for both directions of flow by means of [ 14 C]sucrose washout during perfusion as well as by direct measurement of [ 14 C]sucrose entrapped during perfusion. A three- to fourfold enlargement of the total hepatic extracellular space was found during retrograde perfusion by both approaches. Examination of perfusion-fixed livers by light microscopy and morphometry revealed that marked distension of the sinusoids occurred during retrograde perfusion and that this accounts for the observed increase in the [ 14 C]sucrose space. These findings support the hypothesis that maximum resistance to perfusate flow in the isolated perfused rat liver is located at the presinusoidal level. In addition, increased transit time of perfusate through the liver and greater sinusoidal surface area resulting from sinusoidal distension may account for the higher extraction of 12-NBDS and possibly other compounds by retrograde perfused liver

  5. Fractures after multimodality treatment of soft tissue sarcomas with isolated limb perfusion and radiation; likely to occur and hard to heal.

    Science.gov (United States)

    Seinen, J M; Jutte, P C; Been, L B; Pras, E; Hoekstra, H J

    2018-04-24

    Treatment associated fractures (TAFs) are known severe side effects after surgery and radiotherapy for soft tissue sarcoma (STS). There is no literature about TAF after multimodality treatment with isolated limb perfusion (ILP) for locally advanced STS. This study aimed to analyze predictive factors, treatment and outcome for TAF after multimodality treatment with ILP. Out of 126 consecutive patients undergoing ILP after 1991 till now, 25 patients were excluded due to no surgery or direct amputation at initial surgery. Therefore, 101 patients were at risk and 12 developed a TAF (12%). The majority of tumors was located at the upper leg and knee (N = 60), and 11 patients developed a TAF (18%) after median 28 (5-237) months. Twenty-five tumors were located at the lower leg, and 1 patient developed a TAF after 12 months (4%). No patients with a tumor at the upper extremities (N = 16) developed a TAF. Ten out of 12 patients with a fracture received adjuvant RT with a dose of 50 Gy, and a median boost dose of 18 (10-20) Gy. Predictive factors were periosteal stripping, age over 65 years at time of treatment and tumor size after ILP ≥10 cm. Multivariate analysis showed periosteal stripping and tumor size after ILP ≥10 cm as significant predictive factors. The majority of the fractures were treated with intramedullary nailing. Only one of 12 patients without radiotherapy reached bone union (8%). The median survival after developing TAF was 18 (1-195) months. The overall risk of TAF after multimodality treatment with ILP was relatively high with 15% at ten years. The incidence of TAF for patients with tumors located at the thigh and knee after resection with periosteal stripping and radiotherapy was even >50%. The treatment of these fractures is challenging due to the high non-union rate, requiring an extensive orthopedic oncological TAF experience. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical

  6. Energy utilization and gluconeogenesis in isolated leech segmental ganglia: Quantitative studies on the control and cellular localization of endogenous glycogen.

    Science.gov (United States)

    Pennington, A J; Pentreath, V W

    1988-01-01

    The isolated segmental ganglia of the horse leech Haemopis sanguisuga were used as a model system to study the utilization and control of glycogen stores within nervous tissue. The glycogen in the ganglia was extracted and assayed fluorimentrically and its cellular localization and turnover studied by autoradiography in conjunction with [(3)H]glucose. We measured the glycogen after various periods of electrical stimulation and after incubation with K(+), Ca(2+), ouabain and glucose. The results for each experimental ganglion were compared to a paired control ganglion and the results analysed by paired t-tests. Electrical stimulation caused sequential changes in glycogen levels: a reduction of up to 67% (5-10 min); followed by an increase of up to 124% (between 15-50 min); followed by a reduction of up to 63% (60-90 min). Values were calculated for glucose utilization (e.g. 0.53 ?mol glucose/gm wet weight/min after 90 min) and estimates derived for glucose consumption per action potential per neuron (e.g. 0.12 fmol at 90 min). Glucose (1.5-10 mM) increased the amount of glycogen (1.5 mM by 30% at 60 min) and attenuated the effects of electrical stimulation. Ouabain (1 mM) blocked the effect of 5 min electrical stimulation. Nine millimolar K(+) increased glycogen by 27% after 10 min and decreased glycogen by 34% after 60 min; 3 mM Ca(2+) had no effect after 10 or 20 min and decreased glycogen by 29% after 60 min. Other concentrations of K(+) and Ca(2+) reduced glycogen after 60 min. Autoradiographic analysis demonstrated that the effects of elevated K(+) were principally within the glial cells. We conclude that (i) the glycogen stores in the glial cells of leech segmental ganglia provide an endogenous energy source which can support sustained neuronal activity, (ii) both electrical stimulation and elevated K(+) can induce gluconeogenesis within the ganglia, (iii) that electrical activation of neurons produces changes in the glycogen in the glial cells which are

  7. Utilization by the isolated perfused rat liver of N-acetyl-D-(1-/sup 14/C)galactosamine and N-brace/sup 3/H)-acetyl-D-galactosamine for the biosynthesis of glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    MacNicoll, A D; Wusteman, F S; Powell, G M; Curtis, C G [University Coll., Cardiff (UK)

    1978-08-15

    The isolated perfused rat liver system has been used to monitor the utilization of N-(/sup 3/H)acetyl-D-galactosamine and N-acetyl-D-(1-/sup 14/C)galactosamine for the biosynthesis of radiolabeled glycoproteins, which are subsequently secreted into the plasma. Both radiolabels appear in a number of different glycoproteins, predominantly as sialic acid and N-acetylglucosamine. The ratio of labelled sialic acid to labelled N-acetylglucosamine varies for different glycoproteins, but the bulk of N-acetyl-D-galactosamine is incorporated without deacetylation.

  8. [Dynamics of the amino acid composition of the medium during cultivation of isolated liver and kidney by the controlled perfusion method].

    Science.gov (United States)

    Barashkov, V A; Gitel'zon, I I; Nefedov, V P; Trubachev, I N

    1975-11-01

    The dynamics of the medium amino acid composition was studied during a 6-hour perfusion of dog kidney and liver by a mixture of autogenic plasma and medium 199 (a ratio of 2 : 3). In comparison to the initial level the amount of histidine during 6-hour cultivation of the kidney was found to increase 2.2 times, that of glutamic acid--1.7 times, and of alanine and lysine--1.6 times. At the same time the amount of arginine, serine and asparagic acid became 3.3 times and of glutamine and threonine--2.5 times lower. With the liver perfusion the level of glutaminic acid became 2.9 times, of alanine--2.3 times, of cystine--2 times and of glycine--1.5 times higher. With the liver perfusion the level of arginine decreased so rapidly that none was found in the medium after a 2-hour perfusion. The described method of amino acid analysis during the cultivation of the organs could serve as means for elaborating and correcting the culture media.

  9. Beneficial effects of hyperosmotic perfusion in the myocardium after ischemia/reperfusion injury in isolated rat hearts Efeitos benéficos da perfusão hiperosmótica no miocárdio após lesão isquemia/reperfusão em corações isolados de ratos

    Directory of Open Access Journals (Sweden)

    Yong Cao

    2013-03-01

    Full Text Available OBJECTIVE: A simple method to reduce the ischemia/reperfusion injury that can accompany cardiac surgery would have great clinical value. This study was to investigate the effect of hyperosmotic perfusion on ischemia/reperfusion injury in isolated perfused rat hearts. METHOD: Forty male Sprague-Dawley rats were randomly divided either to have their isolated hearts perfused with normal osmotic buffer or buffer made hyperosmotic by addition of glucose. Hearts were then subjected to 30 min ischemia followed by 30 min reperfusion. Coronary flow, time to ischemic arrest, reperfusion arrhythmia, and ventricular function were recorded. Creatine phosphokinase leakage into the coronary artery, and myocardial content and activity of superoxide dismutase and catalase were also examined. RESULTS: Rat hearts with hyperosmotic perfusion showed higher coronary flow, a prolonged time to ischemic arrest (10.60 vs. 5.63 min, POBJETIVO: Um método simples para reduzir a lesão de isquemia/reperfusão que pode acompanhar a cirurgia cardíaca teria grande valor clínico. O objetivo deste estudo foi investigar o efeito da perfusão hiperosmótica na isquemia/reperfusão em corações isolados de ratos perfundidos. MÉTODOS: Quarenta ratos machos Sprague-Dawley foram divididos aleatoriamente e tiveram os seus corações isolados perfundidos com tampão osmótico normal ou tampão hiperosmótico com a adição de glucose. Os corações foram então submetidos a 30 minutos de isquemia, seguida de 30 min de reperfusão. O fluxo coronariano, tempo de parada isquêmica, arritmia de reperfusão e da função ventricular foram registrados. Vazamento creatinofosfoquinase na artéria coronária, o miocárdio e atividade de superóxido dismutase e catalase foram também examinados. RESULTADOS: Crações de ratos com perfusão hiperosmótica apresentaram maior fluxo coronariano, tempo prolongado de parada isquêmica (10,60 vs. 5,63 min, P<0,005, menor pontuação de reperfus

  10. 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

  11. 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

  12. Fabrication and perfusion culture of anatomically shaped artificial bone using stereolithography

    International Nuclear Information System (INIS)

    Du, Dajiang; Asaoka, Teruo; Ushida, Takashi; Furukawa, Katsuko S

    2014-01-01

    Because patient bone defects are usually varied and complicated in geometry, it would be preferred to fabricate custom-made artificial bone grafts that are anatomically specific to individual patient defects. Using a rabbit femoral segment as a bone reconstruction model, we successfully produced customized ceramic scaffolds by stereolithography, which not only had an anatomically correct external shape according to computed tomography data but also contained an interconnecting internal network of channels designed for perfusion culture. Rabbit bone marrow stromal cells were isolated and cultured with these scaffolds using a novel oscillatory perfusion system that was stereolithographically fabricated to fit well to the unique scaffold shapes. After five days of three-dimensional culture with oscillatory perfusion, the cells attached and proliferated homogenously in the scaffolds. However, control cells inside the scaffolds cultured under static conditions were dead after prolonged in vitro culture. Cellular DNA content and alkaline phosphatase activities were significantly higher in the perfusion group versus the static group. Therefore, anatomically correct artificial bone can be successfully constructed using stereolithography and oscillatory culture technology, and could be useful for bone engraftment and defect repair. (paper)

  13. Ischemic Segment Detection using the Support Vector Domain Description

    DEFF Research Database (Denmark)

    Hansen, Michael Sass; Ólafsdóttir, Hildur; Sjöstrand, Karl

    2007-01-01

    Myocardial perfusion Magnetic Resonance (MR) imaging has proven to be a powerful method to assess coronary artery diseases. The current work presents a novel approach to the analysis of registered sequences of myocardial perfusion MR images. A previously reported AAM-based segmentation and regist...... segments found by assessment of the three common perfusion parameters; maximum upslope, peak and time-to-peak obtained pixel-wise....

  14. Non-contrast MRI perfusion angiosome in diabetic feet

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jie [Cardiovascular Imaging Lab, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Hastings, Mary K.; Mueller, Michael J. [Washington University School of Medicine, The Program in Physical Therapy, St. Louis, MO (United States); Muccigross, David; Hildebolt, Charles F. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Fan, Zhaoyang [Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Los Angeles, CA (United States); Gao, Fabao [West China Hospital, Sichuan University, Department of Radiology, Chengdu (China); Curci, John [Washington University School of Medicine, The Department of Surgery, St. Louis, MO (United States)

    2015-01-15

    The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

  15. Non-contrast MRI perfusion angiosome in diabetic feet

    International Nuclear Information System (INIS)

    Zheng, Jie; Hastings, Mary K.; Mueller, Michael J.; Muccigross, David; Hildebolt, Charles F.; Fan, Zhaoyang; Gao, Fabao; Curci, John

    2015-01-01

    The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

  16. The effectiveness of a high output/short duration radiofrequency current application technique in segmental pulmonary vein isolation for atrial fibrillation

    DEFF Research Database (Denmark)

    Nilsson, Brian; Chen, Xu; Pehrson, Steen

    2006-01-01

    groups. In the conventional group (Group 1, 45 patients), the power output was limited to 30 W with a target temperature of 50 degrees C and an RF preset duration of 120 s. In the novel group (Group 2, 45 patients), the maximum power output was preset to 45 W, with a target temperature of 55 degrees C......AIMS: Segmental pulmonary vein (PV) isolation by radiofrequency (RF) catheter ablation has become a curative therapy for atrial fibrillation (AF). However, the long procedure time limits the wide application of this procedure. The aim of the current study was to compare a novel ablation technique...... and duration of 20 s. In Group 2, a significant reduction in the PV isolation time (127+/-57 vs. 94+/-33 min, P

  17. The beneficial in vitro effects of lovastatin and chelerythrine on relaxatory response to acetylcholine in the perfused mesentric bed isolated from diabetic rats.

    Science.gov (United States)

    Fatehi-Hassanabad, Zahra; Imen-Shahidi, Mohsen; Fatehi, Mohammad; Farrokhfall, Khadijeh; Parsaeei, Heidar

    2006-03-27

    Diabetes mellitus is associated with an increased risk of cardiovascular disease. Endothelial dysfunction (i.e. decreased endothelium-dependent vasorelaxation) plays a key role in the pathogenesis of diabetic vascular disease. The present study was undertaken to determine whether diabetes induced by streptozotocin alters mesenteric responses to vasodilators and, if so, to study the acute in vitro effects of lovastatin and chelerythrine. Endothelial function was assessed in constantly perfused preparation removed from rats, 12 weeks after treatment with either saline or streptozotocin (45 mg/kg, intraperitoneally). In pre-contracted mesenteric beds (with 100 microM phenylephrine) removed from diabetic rats, the concentration response curve to acetylcholine, but not to sodium nitroprusside, was significantly reduced. Perfusion with lovastatin (10 microM for 20 min) or chelerythrine (1 microM for 20 min) significantly improved the acetylcholine-mediated relaxation in preparations removed from diabetic but not control rats. Pre-incubation of tissue with N(G)-nitro-L-argenine methyl ester hydrochloride (10 microM for 20 min) inhibited the beneficial effect of lovastatin but not chelerythrine. Pre-treatment of tissue with indomethacin (10 microM for 20 min) did not modify the effects of lovastatin or chelerythrine on acetylcholine responses. The present results demonstrate that endothelial dysfunction induced by diabetes (in a resistant vasculature, such as rat mesenteric bed) may be improved by an acute exposure to either lovastatin or chelerythrine. Furthermore, our results suggest that the beneficial effect of lovastatin is mediated via the nitric oxide pathway.

  18. Nifedipine and thallium-201 myocardial perfusion in progressive systemic sclerosis

    International Nuclear Information System (INIS)

    Kahan, A.; Devaux, J.Y.; Amor, B.

    1986-01-01

    Heart disease in patients with progressive systemic sclerosis may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. To determine whether abnormalities of myocardial perfusion in this disorder are potentially reversible, we evaluated the effect of the coronary vasodilator nifedipine on myocardial perfusion assessed by thallium-201 scanning in 20 patients. Thallium-201 single-photon-emission computerized tomography was performed under control conditions and 90 minutes after 20 mg of oral nifedipine. The mean (+/- SD) number of left ventricular segments with perfusion defects decreased from 5.3 +/- 2.0 to 3.3 +/- 2.2 after nifedipine (P = 0.0003). Perfusion abnormalities were quantified by a perfusion score (0 to 2.0) assigned to each left ventricular segment and by a global perfusion score (0 to 18) for the entire left ventricle. The mean perfusion score in segments with resting defects increased from 0.97 +/- 0.24 to 1.26 +/- 0.44 after nifedipine (P less than 0.00001). The mean global perfusion score increased from 11.2 +/- 1.7 to 12.8 +/- 2.4 after nifedipine (P = 0.003). The global perfusion score increased by at least 2.0 in 10 patients and decreased by at least 2.0 in only 1. These observations reveal short-term improvement in thallium-201 myocardial perfusion with nifedipine in patients with progressive systemic sclerosis. The results are consistent with a potentially reversible abnormality of coronary vasomotion in this disorder, but the long-term therapeutic effects of nifedipine remain to be determined

  19. Histamine combined with melphalan in isolated limb perfusion for the treatment of locally advanced soft tissue sarcomas: preclinical studies in rats Histamina combinada ao melfalano na perfusão de membro isolado para o tratamento de sarcomas de partes moles localmente avançado: estudos pré-clínicos em ratos

    Directory of Open Access Journals (Sweden)

    Flavia Brunstein

    2005-08-01

    Full Text Available PURPOSE: To evaluate the potential benefit of histamine combined with melphalan in the isolated limb perfusion (ILP as an alternative to TNF-alfa and melphalan combination, for the treatment of irressectable soft tissue sarcomas of the limbs in Brown Norway (BN rats. METHODS: 20 BN rats had small fragments of syngeneic BN-175 fibosarcoma inserted on the right hind limb. In 7-10 days the tumor reached a median diameter of 12-15 mm and they were randomly divided in four groups (sham, melphalan, histamine and escalating doses of histamine combined to melphalan being submitted to experimental ILP for 30 minutes. Tumors were measured daily with a caliper and the volume was calculated. RESULTS: Response curves showed a significant effect of the combination of histamine 200 mg/mL with melphalan, with 66% overall response, including 33% complete responses (pOBJETIVO: Avaliar o potencial benéfico da histamina combinada ao melfalano, na perfusão de membro isolado (PMI, como alternativa à combinação TNF-alfa mais melfalano, no tratamento de sarcomas de partes moles irressecaveis em extremidades, em ratos de linhagem Brown Norway (BN. MÉTODOS: 20 ratos BN foram submetidos a implantação de fragmentos de fibrosarcoma singênico BN-175 na pata traseira direita. Em cerca de 7-10 dias o tumor atingiu um diâmetro médio de 12-15 mm e foram aleatóriamente divididos em quatro grupos (controle, melfalano, histamina em doses progessivas combinada ao melfalano e histamina sendo submetidos a PMI experimental por 30 minutos. Os tumores foram então medidos diariamente com o uso de paquímetro e o volume tumoral calculado. RESULTADOS: As curvas de resposta mostram um efeito significativo da combinação de Histamina na concentração de 200 mg/mL ao melfalano, com 66% de resposta global incluindo 33% de respostas completas (p < 0.01. Não houve efeitos colaterais sistêmicos e localmente apenas edema leve e transitório nos animais tratados com histamine

  20. Scintigraphic and MR perfusion imaging in preoperative evaluation for lung volume reduction surgery. Pilot study results

    International Nuclear Information System (INIS)

    Johkoh, Takeshi; Mueller, N.L.; Kavanagh, P.V

    2000-01-01

    To compare MR perfusion imaging with perfusion scintigraphy in the evaluation of patients with pulmonary emphysema being considered for lung volume reduction surgery. Six patients with pulmonary emphysema and two normal individuals were evaluated by MR perfusion imaging, perfusion scintigraphy, and selective bilateral pulmonary angiography. MR images were obtained with an enhanced fast gradient recalled echo with three-dimensional Fourier transformation technique (efgre 3D) (6.3/1.3; flip angle, 30 deg C; field of view, 45-48 cm; matrix, 256 x 160). The presence or absence of perfusion defects in each segment was evaluated by two independent observers. Using angiography as the gold standard, the sensitivity, specificity, and accuracy of MR perfusion imaging in detecting focal perfusion abnormalities were 90%, 87%, and 89%, respectively, while those of perfusion scintigraphy were 71%, 76%, and 71%, respectively. The diagnostic accuracy of MR perfusion imaging was significantly higher than that of scintigraphy (p<0.001, McNemar test). There was good agreement between two observers for MR perfusion imaging (kappa statistic, 0.66) and only moderate agreement for perfusion scintigraphy (kappa statistic, 0.51). MR perfusion imaging is superior to perfusion scintigraphy in the evaluation of pulmonary parenchymal perfusion in patients with pulmonary emphysema. (author)

  1. Dual-energy CT perfusion and angiography in chronic thromboembolic pulmonary hypertension: diagnostic accuracy and concordance with radionuclide scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Dournes, Gael; Verdier, Damien; Montaudon, Michel; Laurent, Francois; Lederlin, Mathieu [Hopital Haut-Leveque, CHU Bordeaux, Department of Medical Imaging, Pessac (France); University Bordeaux Segalen, Bordeaux Cedex (France); Bullier, Eric; Riviere, Annalisa [Hopital Haut-Leveque, CHU Bordeaux, Department of Nuclear Medicine, Pessac (France); Dromer, Claire [Hopital Haut-Leveque, CHU Bordeaux, Department of Respiratory Diseases, Pessac (France); Picard, Francois [Hopital Haut-Leveque, CHU Bordeaux, Department of Cardiology, Pessac (France); Billes, Marc-Alain [Hopital Haut-Leveque, CHU Bordeaux, Department of Cardiac Surgery, Pessac (France); Corneloup, Olivier [Hopital Haut-Leveque, CHU Bordeaux, Department of Medical Imaging, Pessac (France)

    2014-01-15

    To evaluate the diagnostic accuracy of dual-energy computed tomography (DECT) perfusion and angiography versus ventilation/perfusion (V/Q) scintigraphy in chronic thromboembolic pulmonary hypertension (CTEPH), and to assess the per-segment concordance rate of DECT and scintigraphy. Forty consecutive patients with proven pulmonary hypertension underwent V/Q scintigraphy and DECT perfusion and angiography. Each imaging technique was assessed for the location of segmental defects. Diagnosis of CTEPH was established when at least one segmental perfusion defect was detected by scintigraphy. Diagnostic accuracy of DECT perfusion and angiography was assessed and compared with scintigraphy. In CTEPH patients, the per-segment concordance between scintigraphy and DECT perfusion/angiography was calculated. Fourteen patients were diagnosed with CTEPH and 26 with other aetiologies. DECT perfusion and angiography correctly identified all CTEPH patients with sensitivity/specificity values of 1/0.92 and 1/0.93, respectively. At a segmental level, DECT perfusion showed moderate agreement (κ = 0.44) with scintigraphy. Agreement between CT angiography and scintigraphy ranged from fair (κ = 0.31) to slight (κ = 0.09) depending on whether completely or partially occlusive patterns were considered, respectively. Both DECT perfusion and angiography show satisfactory performance for the diagnosis of CTEPH. DECT perfusion is more accurate than angiography at identifying the segmental location of abnormalities. (orig.)

  2. Dual-energy CT perfusion and angiography in chronic thromboembolic pulmonary hypertension: diagnostic accuracy and concordance with radionuclide scintigraphy

    International Nuclear Information System (INIS)

    Dournes, Gael; Verdier, Damien; Montaudon, Michel; Laurent, Francois; Lederlin, Mathieu; Bullier, Eric; Riviere, Annalisa; Dromer, Claire; Picard, Francois; Billes, Marc-Alain; Corneloup, Olivier

    2014-01-01

    To evaluate the diagnostic accuracy of dual-energy computed tomography (DECT) perfusion and angiography versus ventilation/perfusion (V/Q) scintigraphy in chronic thromboembolic pulmonary hypertension (CTEPH), and to assess the per-segment concordance rate of DECT and scintigraphy. Forty consecutive patients with proven pulmonary hypertension underwent V/Q scintigraphy and DECT perfusion and angiography. Each imaging technique was assessed for the location of segmental defects. Diagnosis of CTEPH was established when at least one segmental perfusion defect was detected by scintigraphy. Diagnostic accuracy of DECT perfusion and angiography was assessed and compared with scintigraphy. In CTEPH patients, the per-segment concordance between scintigraphy and DECT perfusion/angiography was calculated. Fourteen patients were diagnosed with CTEPH and 26 with other aetiologies. DECT perfusion and angiography correctly identified all CTEPH patients with sensitivity/specificity values of 1/0.92 and 1/0.93, respectively. At a segmental level, DECT perfusion showed moderate agreement (κ = 0.44) with scintigraphy. Agreement between CT angiography and scintigraphy ranged from fair (κ = 0.31) to slight (κ = 0.09) depending on whether completely or partially occlusive patterns were considered, respectively. Both DECT perfusion and angiography show satisfactory performance for the diagnosis of CTEPH. DECT perfusion is more accurate than angiography at identifying the segmental location of abnormalities. (orig.)

  3. Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients.

    Science.gov (United States)

    Le Faivre, Julien; Duhamel, Alain; Khung, Suonita; Faivre, Jean-Baptiste; Lamblin, Nicolas; Remy, Jacques; Remy-Jardin, Martine

    2016-11-01

    To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE). 62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs). The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population). Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging. • Dual-energy computed tomography generates standard diagnostic imaging and lung perfusion analysis. • Depiction of CPE on central arteries relies on standard diagnostic imaging. • Detection of peripheral CPE is improved by perfusion imaging.

  4. Perfusion dyssynchrony analysis

    NARCIS (Netherlands)

    Chiribiri, A.; Villa, A.D.M.; Sammut, E.; Breeuwer, M.; Nagel, E.

    2015-01-01

    AIMS: We sought to describe perfusion dyssynchrony analysis specifically to exploit the high temporal resolution of stress perfusion CMR. This novel approach detects differences in the temporal distribution of the wash-in of contrast agent across the left ventricular wall. METHODS AND RESULTS:

  5. Enhanced magnetic resonance pulmonary perfusion imaging in diagnosing pulmonary embolism: preliminary investigation

    International Nuclear Information System (INIS)

    Huang Xiaoyong; Du Jing; Zhang Zhaoqi; Guo Xi; Yan Zixu; Jiang Hong; Wang Wei

    2005-01-01

    Objective: This study was designed to investigate the sensitivity and specificity of magnetic resonance pulmonary perfusion imaging (MRPP) in diagnosing pulmonary embolism (PE) compared with enhanced magnetic resonance pulmonary angiography (MRPA) and pulmonary radionuclide perfusion imaging. Methods: Fourteen patients were definitely diagnosed as PE, whose ages were from 19 to 71 years old and mean 45.5 ± 19.8 years old. All patients under went MRPA and MRPP and 3 patients were examined again after thrombolytic treatment. Five patients underwent pulmonary radionuclide perfusion imaging. Setting ROI in top, middle, bottom of lung area and abnormal area respectively, we detected signal intensity and time-signal curve to obtain the transformation rate of signal (TROS) during perfusion peak value. Results: In 14 pulmonary embolism patients, MRPA found 62 branches of pulmonary artery obstruction. Fifty-five abnormal pulmonary perfusion zones were found by MRPP, and the above results were very alike. The coincidence was 88.71%. In 14 cases, MRPP could show 25 subsegments lesion below segments. In 5 patients who had both results Of MRPP and ECT at the same time. MRPP shows 33 perfusion defect zones and 37 segments were found by ECT, the sensitivity was 89.19%. After thrombolytic treatment, both the status of the affected pulmonary artery improved markedly and perfusion defect zones reduced obviously in 3 cases by MRPP and MRPA. TROS in normal perfusion zones perfusion defect zones and low perfusion zones had significant difference (t=22.882, P<0.01). Conclusion: Contrast enhanced MR pulmonary perfusion can show both perfusion defect zones and low perfusion zones in pulmonary embolism. Time-signal curve can show the period of maximum no perfusion zones in pulmonary artery embolism zones. And the amplitude of fluctuation is small with miminum TROS. MRPP has significant values especially in showing pulmonary artery embolism in segments and subsegments. Using both MRPP and

  6. Laser doppler perfusion imaging

    International Nuclear Information System (INIS)

    Waardell, K.

    1992-01-01

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 μm. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. 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

  9. Role of adenosine 99MTc sestamibi myocardial perfusion spect in evaluation of symptomatic hypertensives with recent onset left bundle branch block

    International Nuclear Information System (INIS)

    Padma, S.; Sundaram, P.S.; Zachariah, M.; Hariads, K.K.

    2004-01-01

    Objectives: Adenosine pharmacological stress Myocardial Perfusion Imaging (AMPI) is the preferred imaging modality for IHD evaluation in pts with Left Bundle Branch Block (LBBB). Good prognosis has been reported in recent onset LBBB pts with normal MPI. Our aim was to evaluate the utility and analyze the predictive value of SestaMIBI AMPI in symptomatic recent onset LBBB hypertensives for coronary artery disease evaluation. Methods: 29 hypertensive pts, age range 36-72yrs, mean 54+ 6 yrs, M:F- 21:8 with recent onset complete LBBB, under evaluation for typical/atypical angina who had AMPI between Nov 02-Nov 03, were retrospectively analyzed. LBBB was diagnosed ECG wise if there is prolonged QRS complex i.e. 0.125sec or more in sinus/supraventricular rhythm, a QS or rS complex in lead 1, and an R-wave peak time of 0.06sec in leads 1, V5 or V6 with no Q wave in same lead. Pts with prior Myocardial Infarct / revasularisation, pacemaker induced LBBB were excluded. Single day 6 min. Adenosine infusion Stress-rest 99m Tc MIBI gated MPI was performed with a dual head variable angle Gamma Camera at 76-degree angle. Coronary Angiogram (CAG) correlation was available in 24 pts. Results: Myocardial perfusion SPECT images were assessed visually and by a 20-segment model. Location, extent and severity of the LV perfusion defects were evaluated. 6/29 pts (20.7%) had normal stress-rest perfusion in all LV segments.12 (41.4%) had isolated septal fixed defect with normal perfusion in rest of the segments.3 pts (10.3%)showed isolated reversible septal defects while 8(27.6%) had reversible septal defects with reversible defects in other LV segments also. Pts with fixed septal perfusion defect showed moderate to good septal wall thickening in gated SPECT images. While all pts with multiple reversible perfusion defects had angiographically proven coronary artery disease (i.e. 3pts had LAD lesion, 2 had Triple vessel and 3 showed double vessel lesions), 1 out of 3 pts with isolated

  10. Uptake of [3H]PAH and [14C]urate into isolated proximal tubular segments of the pig kidney

    International Nuclear Information System (INIS)

    Schali, C.; Roch-Ramel, F.

    1981-01-01

    Segments of proximal convoluted (PCT) and proximal straight (PST) tubules of minipigs and normal-sized pigs were microdissected (without collagenase treatment) and incubated (30 min, 37 0 C, pH 7.4) in Ringer solution (under O 2 ) containing [ 3 H]PAH (3.10 -5 M) or [ 14 C]urate (9.10 -5 M) and, in inhibitor studies, probenecid, pyrazinoic acid (PZA), urate, or PAH, all at 1 mM. In both strains the uptake of [ 3 H]PAH expressed as mean T/M ratio (cpm per ml tissue water/cpm per ml incubation medium) was significantly higher (P 14 C]urate. In eight minipigs the T/M was 4.9 +/- 0.5 in 24 PCT and 2 +/- 0.2 in 25 PST. In normal-sized pigs the T/M was 3.8 +/- 0.3 in 35 PCT (five pigs) and 1.9 +/- 0.4 in eight PST (two pigs). In inhibitor studies urate significantly depressed the uptake of [ 3 H]PAH, and unlabeled PAH depressed the uptake of [ 14 C]urate. PZA significantly inhibited the uptake of [ 14 C]urate but not that of [ 3 H]PAH, whereas probenecid had a strong inhibitory efect on the uptake of both compounds. These results suggest that [ 14 C]urate and [ 3 H]PAH are transported by a transport system located mainly in the proximal convoluted tubule. These findings are in contrast in the findings are in contrast to the findings obtained in rabbits in which the transport system of PAH and urate is mainly located in the proximal part of the pars recta

  11. Skin perfusion pressure measured by isotope washout in legs with arterial occlusive disease. Evaluation of different tracers, comparison to segmental systolic pressure, angiography and transcutaneous oxygen tension and variations during changes in systemic blood pressure

    DEFF Research Database (Denmark)

    Holstein, P; Trap-Jensen, J; Bagger, H

    1983-01-01

    Hg (range 18-98) (P less than 0.02). The average washout constant for the three different tracers were approximately equal and correlated statistically significant with the SPP; (2) In 59 legs with AOD, segmental SPP was compared to segmental systolic blood pressures on the thigh, calf, ankle and first...... digit (strain gauge technique). The two different methods correlated statistically significant at all four levels, but the systolic blood pressures were higher than the SPP in particular in diabetic legs; (3) Angiograms in 35 legs with AOD showed that the SPP on the ankle was only consistently decreased...

  12. Consideration of Normal Variation of Perfusion Measurements in the Quantitative Analysis of Myocardial Perfusion SPECT: Usefulness in Assessment of Viable Myocardium

    International Nuclear Information System (INIS)

    Paeng, Jin Chul; Lim, Il Han; Kim, Ki Bong; Lee, Dong Soo

    2008-01-01

    Although automatic quantification software of myocardial perfusion SPECT provides highly objective and reproducible quantitative measurements, there is still some limitation in the direct use of quantitative measurements. In this study we derived parameters using normal variation of perfusion measurements, and tried to test the usefulness of these parameters. In order to calculate normal variation of perfusion measurements on myocardial perfusion SPECT, 55 patients (M:F=28:27) of low-likelihood for coronary artery disease were enrolled and 201 Tl rest / 99m Tc-MIBI stress SPECT studies were performed. Using 20-segment model, mean (m) and standard deviation (SD) of perfusion were calculated in each segment. As a myocardial viability assessment group, another 48 patients with known coronary artery disease, who underwent coronary artery bypass graft surgery (CABG) were enrolled. 201 Tl rest / 99m Tc-MIBI stress / 201 Tl 24-hr delayed SPECT was performed before CABG and SPECT was followed up 3 months after CABG. From the preoperative 24-hr delayed SPECT, Q delay (perfusion measurement), Δ delay (Q delay .m) and Z delay ((Q delay .m)/SD) were defined and diagnostic performances of them for myocardial viability were evaluated using area under curve (AUC) on receiver operating characteristic (ROC) curve analysis. Segmental perfusion measurements showed considerable normal variations among segments. In men, the lowest segmental perfusion measurement was 51.8±6.5 and the highest segmental perfusion was 87.0±5.9, and they are 58.7±8.1 and 87.3±6.0, respectively in women. In the viability assessment, Q delay showed AUC of 0.633, while those for Δ delay and Z delay were 0.735 and 0.716, respectively. The AUCs of Δ delay and Z delay were significantly higher than that of Q delay (p=0.001 and 0.018, respectively). The diagnostic performance of Δ delay , which showed highest AUC, was 85% of sensitivity and 53% of specificity at the optimal cutoff of -24.7. On automatic

  13. Pulmonary perfusion ''without ventilation''

    International Nuclear Information System (INIS)

    Chapman, C.N.; Sziklas, J.J.; Spencer, R.P.; Rosenberg, R.J.

    1983-01-01

    An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a ''reversed ventilation/perfusion mismatch.''

  14. Diagnostic performance of dual-energy CT stress myocardial perfusion imaging: direct comparison with cardiovascular MRI.

    Science.gov (United States)

    Ko, Sung Min; Song, Meong Gun; Chee, Hyun Kun; Hwang, Hweung Kon; Feuchtner, Gudrun Maria; Min, James K

    2014-12-01

    The purpose of this study was to assess the diagnostic performance of stress perfusion dual-energy CT (DECT) and its incremental value when used with coronary CT angiography (CTA) for identifying hemodynamically significant coronary artery disease. One hundred patients with suspected or known coronary artery disease without chronic myocardial infarction detected with coronary CTA underwent stress perfusion DECT, stress cardiovascular perfusion MRI, and invasive coronary angiography (ICA). Stress perfusion DECT and cardiovascular stress perfusion MR images were used for detecting perfusion defects. Coronary CTA and ICA were evaluated in the detection of ≥50% coronary stenosis. The diagnostic performance of coronary CTA for detecting hemo-dynamically significant stenosis was assessed before and after stress perfusion DECT on a per-vessel basis with ICA and cardiovascular stress perfusion MRI as the reference standard. The performance of stress perfusion DECT compared with cardiovascular stress perfusion MRI on a per-vessel basis in the detection of perfusion defects was sensitivity, 89%; specificity, 74%; positive predictive value, 73%; negative predictive value, 90%. Per segment, these values were sensitivity, 76%; specificity, 80%; positive predictive value, 63%; and negative predictive value, 88%. Compared with ICA and cardiovascular stress perfusion MRI per vessel territory the sensitivity, specificity, positive predictive value, and negative predictive value of coronary CTA were 95%, 61%, 61%, and 95%. The values for stress perfusion DECT were 92%, 72%, 68%, and 94%. The values for coronary CTA and stress perfusion DECT were 88%, 79%, 73%, and 91%. The ROC AUC increased from 0.78 to 0.84 (p=0.02) with the use of coronary CTA and stress perfusion DECT compared with coronary CTA alone. Stress perfusion DECT plays a complementary role in enhancing the accuracy of coronary CTA for identifying hemodynamically significant coronary stenosis.

  15. 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.)

  16. Quantitative aspects of myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Vogel, R.A.

    1980-01-01

    Myocardial perfusion measurements have traditionally been performed in a quantitative fashion using application of the Sapirstein, Fick, Kety-Schmidt, or compartmental analysis principles. Although global myocardial blood flow measurements have not proven clinically useful, regional determinations have substantially advanced our understanding of and ability to detect myocardial ischemia. With the introduction of thallium-201, such studies have become widely available, although these have generally undergone qualitative evaluation. Using computer-digitized data, several methods for the quantification of myocardial perfusion images have been introduced. These include orthogonal and polar coordinate systems and anatomically oriented region of interest segmentation. Statistical ranges of normal and time-activity analyses have been applied to these data, resulting in objective and reproducible means of data evaluation

  17. Mouse myocardial first-pass perfusion MR imaging

    NARCIS (Netherlands)

    Coolen, Bram F.; Moonen, Rik P. M.; Paulis, Leonie E. M.; Geelen, Tessa; Nicolay, Klaas; Strijkers, Gustav J.

    2010-01-01

    A first-pass myocardial perfusion sequence for mouse cardiac MRI is presented. A segmented ECG-triggered acquisition combined with parallel imaging acceleration was used to capture the first pass of a Gd-DTPA bolus through the mouse heart with a temporal resolution of 300-400 msec. The method was

  18. Mouse myocardial first-pass perfusion MR imaging

    NARCIS (Netherlands)

    Coolen, B.F.; Moonen, R.P.M.; Paulis, L.E.M.; Geelen, T.; Nicolay, K.; Strijkers, G.J.

    2010-01-01

    A first-pass myocardial perfusion sequence for mouse cardiac MRI is presented. A segmented ECG-triggered acquisition combined with parallel imaging acceleration was used to capture the first pass of a Gd-DTPA bolus through the mouse heart with a temporal resolution of 300–400 msec. The method was

  19. Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients

    Energy Technology Data Exchange (ETDEWEB)

    Le Faivre, Julien; Khung, Suonita; Faivre, Jean-Baptiste; Remy, Jacques; Remy-Jardin, Martine [University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Duhamel, Alain [University of Lille, Department of Biostatistics, Lille (France); Lamblin, Nicolas [University of Lille, Department of Cardiology, Cardiology Hospital, Lille (France)

    2016-11-15

    To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE). 62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs). The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population). Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging. (orig.)

  20. Reverse ventilation--perfusion mismatch

    International Nuclear Information System (INIS)

    Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

    1984-01-01

    Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients

  1. A Review of Liver Perfusion Method in Toxicology Studies

    Directory of Open Access Journals (Sweden)

    M karami

    2014-06-01

    Full Text Available Introduction: The isolated perfused rat liver is an accepted method in toxicology studies. The isolated perfused rat liver (IPRL is a useful experimental system for evaluating hepatic function without the influence of other organ systems, undefined plasma constituents, and neural-hormonal effects. Methods: The untreated male rats (180-220gr body weight were anesthetised with ether and then surgery with proper method. The abdomen was opened through a midline and one transversal incision and the bile duct was cannulated. Heparin sodium solution (0.5 ml; 500 U/ml in 0.9% NaCl was injected via the abdominal vena cava to prevent blood clotting. The liver inferior venacava was cannulated with PE-10 tubing and secured. The portal vein was immediately cannulated with an 23gr catheter which was secured and then liver was perfused in situ by Krebs- Henseleit buffer (pH 7.4; saturated with 95% O2 and 5% CO2; 37°C at a flow rate of 20 ml/min for 3hr. Temperature, perfusion pressure, flow rate and perfusion fluid pH were closely monitored during the perfusion. Results: Transferase enzymes (ALT, AST alterations can be widely used as a measure of biochemical alterations in order to assess liver damage due to use of drugs such as isoniazid (INH and animal and plant toxins. Accumulated material in gallbladder are valuable samples to assess the level of Glutathione (GSH. Sections of perfused liver tissue can also be effectively analyzed for pathological aspects such as necrosis, fibrosis, cellularity. Conclusion: The isolated perfused rat liver (IPRL is a useful and Sutible experimental system for evaluating hepatic function. In this system, the effects of adjacent organs, on the liver is minimized

  2. Hepatic artery perfusion imaging

    International Nuclear Information System (INIS)

    Thrall, J.H.; Gyves, J.W.; Ziessman, H.A.; Ensminger, W.D.

    1985-01-01

    Organ and region-selective intra-arterial chemotherapy have been used for more than two decades to treat malignant neoplasms in the extremities, head and neck region, pelvis, liver, and other areas. Substantial evidence of improved response to regional chemotherapy now exists, but there are stringent requirements for successful application of the regional technique. First, the chemotherapeutic agent employed must have appropriate pharmacokinetic and pharmacodynamic properties. Second, the drug must be reliably delivered to the tumor-bearing area. This typically requires an arteriographic assessment of the vascular supply of the tumor, followed by placement of a therapeutic catheter and confirmation that the ''watershed'' perfusion distribution from the catheter truly encompasses the tumor. Optimal catheter placement also minimizes perfusion of nontarget organs. Radionuclide perfusion imaging with technetium 99m-labeled particles, either microspheres or macroaggregates of albumin, has become the method of choice for making these assessments. Catheter placement itself is considered by many to represent a type of ''therapeutic'' intervention. However, once the catheter is in the hepatic artery the radionuclide perfusion technique can be used to assess adjunctive pharmacologic maneuvers designed to further exploit the regional approach to chemotherapy. This chapter presents the technetium Tc 99m macroaggregated albumin method for assessing catheter placement and the pharmacokinetic rationale for regional chemotherapy, and discusses two promising avenues for further intervention

  3. Extremity perfusion for sarcoma

    NARCIS (Netherlands)

    Hoekstra, Harald Joan

    2008-01-01

    For more than 50 years, the technique of extremity perfusion has been explored in the limb salvage treatment of local, recurrent, and multifocal sarcomas. The "discovery" of tumor necrosis factor-or. in combination with melphalan was a real breakthrough in the treatment of primarily irresectable

  4. Feasibility of high-resolution quantitative perfusion analysis in patients with heart failure.

    Science.gov (United States)

    Sammut, Eva; Zarinabad, Niloufar; Wesolowski, Roman; Morton, Geraint; Chen, Zhong; Sohal, Manav; Carr-White, Gerry; Razavi, Reza; Chiribiri, Amedeo

    2015-02-12

    Cardiac magnetic resonance (CMR) is playing an expanding role in the assessment of patients with heart failure (HF). The assessment of myocardial perfusion status in HF can be challenging due to left ventricular (LV) remodelling and wall thinning, coexistent scar and respiratory artefacts. The aim of this study was to assess the feasibility of quantitative CMR myocardial perfusion analysis in patients with HF. A group of 58 patients with heart failure (HF; left ventricular ejection fraction, LVEF ≤ 50%) and 33 patients with normal LVEF (LVEF >50%), referred for suspected coronary artery disease, were studied. All subjects underwent quantitative first-pass stress perfusion imaging using adenosine according to standard acquisition protocols. The feasibility of quantitative perfusion analysis was then assessed using high-resolution, 3 T kt perfusion and voxel-wise Fermi deconvolution. 30/58 (52%) subjects in the HF group had underlying ischaemic aetiology. Perfusion abnormalities were seen amongst patients with ischaemic HF and patients with normal LV function. No regional perfusion defect was observed in the non-ischaemic HF group. Good agreement was found between visual and quantitative analysis across all groups. Absolute stress perfusion rate, myocardial perfusion reserve (MPR) and endocardial-epicardial MPR ratio identified areas with abnormal perfusion in the ischaemic HF group (p = 0.02; p = 0.04; p = 0.02, respectively). In the Normal LV group, MPR and endocardial-epicardial MPR ratio were able to distinguish between normal and abnormal segments (p = 0.04; p = 0.02 respectively). No significant differences of absolute stress perfusion rate or MPR were observed comparing visually normal segments amongst groups. Our results demonstrate the feasibility of high-resolution voxel-wise perfusion assessment in patients with HF.

  5. Perfusion CT assessment of the colon and rectum: Feasibility of quantification of bowel wall perfusion and vascularization

    International Nuclear Information System (INIS)

    Khan, Sairah; Goh, Vicky; Tam, Emily; Wellsted, David; Halligan, Steve

    2012-01-01

    The aim was to determine the feasibility of vascular quantification of the bowel wall for different anatomical segments of the colorectum. Following institutional ethical approval and informed consent, 39 patients with colorectal cancer underwent perfusion CT. Blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface area product (PS) were assessed for different segments of the colorectum: ascending, transverse, descending colon, sigmoid, or rectum, that were distant from the tumor, and which were proven normal on contemporary colonoscopy, and subsequent imaging and clinical follow up. Mean (SD) for BF, BV, MTT and PS for the different anatomical colorectal segments were obtained and compared using a pooled t-test. Significance was at 5%. Assessment was not possible in 9 of 39 (23%) patients as the bowel wall was ≤5 mm precluding quantitative analysis. Forty-four segments were evaluated in the remaining 30 patients. Mean BF was higher in the proximal than distal colon: 24.0 versus 17.8 mL/min/100 g tissue; p = 0.009; BV, MTT and PS were not significantly different; BV: 3.46 versus 3.15 mL/100 g tissue, p = 0.45; MTT: 15.1 versus 18.3 s; p = 0.10; PS: 6.84 versus 8.97 mL/min/100 tissue, p = 0.13, respectively. In conclusion, assessment of bowel wall perfusion may fail in 23% of patients. The colorectum demonstrates segmental differences in perfusion.

  6. Feasibility and efficacy of external beam radiotherapy after hyperthermic isolated limb perfusion with TNF-α and melphalan for limb-saving treatment in locally advanced extremity soft-tissue sarcoma

    International Nuclear Information System (INIS)

    Olieman, Annette F.T.; Pras, Elisabeth; Ginkel, Robert J. van; Molenaar, Willemina M.; Koops, Heimen Schraffordt; Hoekstra, Harald J.

    1998-01-01

    Purpose: Hyperthermic isolated limb perfusion (HILP) with tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and melphalan is associated with a dramatic antitumor effect in locally advanced extremity soft-tissue sarcomas (STS). The aim of this study was to demonstrate the feasibility and efficacy of adjuvant radiotherapy after HILP with TNF-α, IFN-γ, and melphalan and delayed surgical resection. Methods and Materials: Between 1991 and 1995, 34 patients--16 males and 18 females, median age 50 (range 18-80) years--underwent HILP for locally advanced extremity STS. Resection of the residual tumor mass was performed in most patients after 6-8 weeks. Fifteen patients with histopathological viable tumor after resection received adjuvent 60-70 Gy external beam radiotherapy (EBRT) (44%, HILP + EBRT group). Nineteen patients received HILP without adjuvent EBRT (56%, HILP-only group). Five patients in the HILP-only group had also distant metastases (15%) and received HILP as a palliative treatment. Treatment morbidity, local recurrences, and regional and distant metastases were scored. Results: During a median follow-up of 34 months (range 8-54), limb salvage was achieved in 29 patients (85%): 14 patients after HILP + EBRT and 15 patients after HILP only. None of the patients from the HILP + EBRT group developed local recurrences; however, five patients from the HILP-only did (26%) (p < 0.05). Regional metastases were observed in one patient from the HILP + EBRT group (7%) and in two patients from the HILP-only group who were treated with curative intent (14%). Distant metastases occurred in four patients after HILP + EBRT (27%) and in four patients after HILP only with curative intent (29%). The mean morbidity (subjective, objective, medical management, and analytical evaluation) score in both groups was, respectively, 0.33 for skin and subcutaneous tissue and for muscle and soft tissue, 0.34 (HILP + EBRT group) and 0.33 (HILP-only group). Conclusion: Adjuvent

  7. Prognostic relevance of {sup 18}F-FDG PET uptake in patients with locally advanced, extremity soft tissue sarcomas undergoing neoadjuvant isolated limb perfusion with TNF-α and melphalan

    Energy Technology Data Exchange (ETDEWEB)

    Andreou, Dimosthenis [Muenster University Hospital, Department of General Orthopedics and Tumor Orthopedics, Muenster (Germany); HELIOS Klinikum Berlin-Buch, Department of Orthopedic Oncology, Sarcoma Center Berlin-Brandenburg, Berlin (Germany); Boldt, Henrike [HELIOS Klinikum Berlin-Buch, Department of Nuclear Medicine, Berlin (Germany); Pink, Daniel [HELIOS Klinikum Bad Saarow, Department of Hematology, Oncology and Palliative Care, Sarcoma Center Berlin-Brandenburg, Bad Saarow (Germany); Jobke, Bjoern [HELIOS Klinikum Berlin-Buch, Department of Radiology, Berlin (Germany); Werner, Mathias [HELIOS Klinikum Emil von Behring, Department of Pathology, Sarcoma Center Berlin-Brandenburg, Berlin (Germany); Schuler, Markus [University Hospital Carl Gustav Carus Dresden, Department of Internal Medicine I, Dresden (Germany); Reichardt, Peter [HELIOS Klinikum Berlin-Buch, Department of Interdisciplinary Oncology, Sarcoma Center Berlin-Brandenburg, Berlin (Germany); Tunn, Per-Ulf [HELIOS Klinikum Berlin-Buch, Department of Orthopedic Oncology, Sarcoma Center Berlin-Brandenburg, Berlin (Germany)

    2014-06-15

    The objective of this study was to determine whether {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET) can adequately assess the risk of systemic disease progression in patients with primary, localized, high-grade soft tissue sarcomas of the extremities undergoing neoadjuvant isolated limb perfusion (ILP) with tumour necrosis factor and melphalan. This was a retrospective analysis of the files of 35 patients who underwent a PET or PET/CT scan prior to and after ILP followed by surgical resection with curative intent between 2006 and 2012. SUV{sub max1} was defined as the maximum standardized uptake value (SUV) at diagnosis, SUV{sub max2} as the maximum SUV after ILP and ΔSUV{sub max} as the percentage difference between SUV{sub max1} and SUV{sub max2}. The median follow-up was 40 months for all patients. The median SUV{sub max1} amounted to 7.6, while the median SUV{sub max2} was 4.7. The median ΔSUV{sub max} was -44 %. Overall survival (OS) probability at 2 and 5 years amounted to 78 and 70 %, respectively, while metastasis-free survival (MFS) probability at 2 and 5 years was 67 and 64 %, respectively. Receiver-operating characteristic (ROC) curve analysis showed that both SUV{sub max2} and ΔSUV{sub max} could predict systemic disease progression, while SUV{sub max1} could not adequately identify patients who went on to develop metastatic disease. The optimal cut-off value was 6.9 for SUV{sub max2} and -31 % for ΔSUV{sub max}. Patients with an SUV{sub max2} <6.9 had a 2-year MFS of 80 %, compared to 31 % for patients with an SUV{sub max2} ≥ 6.9 (p < 0.001). Patients with a ΔSUV{sub max} < -31 %, i.e. patients with a higher metabolic response, had an MFS of 76 % at 2 years, compared to 42 % for patients with a ΔSUV{sub max} ≥ -31 % (p = 0.050). SUV{sub max} after ILP for primary, locally advanced, non-metastatic high-grade soft tissue sarcomas of the extremities appears to be significantly correlated with prognosis. Whether patients

  8. Myocardial Perfusion: Characteristics of Distal Intramyocardial Arteriolar Trees.

    Science.gov (United States)

    Zamir, Mair; Vercnocke, Andrew J; Edwards, Phillip K; Anderson, Jill L; Jorgensen, Steven M; Ritman, Erik L

    2015-11-01

    A combination of experimental, theoretical, and imaging methodologies is used to examine the hierarchical structure and function of intramyocardial arteriolar trees in porcine hearts to provide a window onto a region of myocardial microvasculature which has been difficult to fully explore so far. A total of 66 microvascular trees from 6 isolated myocardial specimens were analyzed, with a cumulative number of 2438 arteriolar branches greater than or equal to 40 μm lumen diameter. The distribution of flow rates within each tree was derived from an assumed power law relationship for that tree between the diameter of vessel segments and flow rates that are consistent with that power law and subject to conservation of mass along hierarchical structure of the tree. The results indicate that the power law index increases at levels of arteriolar vasculature closer to the capillary level, consistent with a concomitant decrease in shear stress acting on endothelial tissue. These results resolve a long standing predicament which could not be resolved previously because of lack of data about the 3D, interconnected, arterioles. In the context of myocardial perfusion, the results indicate that the coefficient of variation of flow rate in pre-capillary distal arterioles is high, suggesting that heterogeneity of flow rate in these arterioles is not entirely random but may be due at least in part to active control.

  9. The effect of pregnancy and estradiol-17 beta treatment on the biliary transport maximum of dibromosulfophthalein, and the glucuronide conjugates of 5-phenyl-5-p-hydroxyphenyl[14C]hydantoin and [14C]morphine in the isolated perfused rat liver

    International Nuclear Information System (INIS)

    Auansakul, A.C.; Vore, M.

    1982-01-01

    The biliary transport maximum (Tm) of three organic axions was determined in the isolated perfused livers of untreated female (control), estradiol-17 beta (E2)-treated female (1 mg/kg/day, s.c. for 14 days), and pregnant (19-21 days of gestation) rats. Dibromosulfophthalein (DBSP), 5-phenyl-5-p-hydroxyphenyl[ 14 C]hydantoin (HPPH) and [ 14 C]morphine were infused continuously into the perfusate for a total dose of 41.2, 18, or 40.5 mumol, respectively. The concentration of [ 14 C]HPPH and [ 14 C]morphine declined in the perfusate, whereas the concentrations of [ 14 C]HPPH glucuronide and [ 14 C]morphine glucuronide increased during the 90-min experiment, indicating that the rate of formation of the glucuronide exceeded its rate of excretion in bile. E2 treatment decreased the Tm (nmol/min/g liver) for [ 14 C]HPPH glucuronide and [ 14 C]morphine glucuronide but not for DBSP, whereas pregnancy decreased the Tm for all three organic anions. Pregnancy, and to a lesser extent E2 treatment, increased liver weight. When expressed per whole liver, the Tm was not altered by pregnancy for any of three organic anions. E2 treatment increased the Tm for DBSP, had no effect on the Tm for HPPH glucuronide and decreased the Tm for [ 14 C]morphine glucuronide. These data suggest the presence of multiple carriers for organic anions which are differentially affected by estrogen treatment and pregnancy

  10. Adenosine-stress dynamic real-time myocardial perfusion CT and adenosine-stress first-pass dual-energy myocardial perfusion CT for the assessment of acute chest pain: Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Weininger, Markus [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC (United States); Ramachandra, Ashok [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Fink, Christian [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Rowe, Garrett W.; Costello, Philip [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Henzler, Thomas [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2012-12-15

    Purpose: Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT in a clinical population with acute chest pain. Methods and materials: Myocardial stress perfusion CT was performed on twenty consecutive patients (15 men, 5 women; mean age 65 ± 8 years) who presented with acute chest pain and were clinically referred for stress/rest SPECT and cardiac MRI. Prior to CT each patient was randomly assigned either to Group A or to Group B in a consecutive order (10 patients per group). Group A underwent adenosine-stress dynamic real-time myocardial perfusion CT using a novel “shuttle” mode on a 2nd generation dual-source CT. Group B underwent adenosine-stress first-pass dual-energy myocardial perfusion CT using the same CT scanner in dual-energy mode. Two experienced observers visually analyzed all CT perfusion studies. CT findings were compared with MRI and SPECT. Results: In Group A 149/170 myocardial segments (88%) could be evaluated. Real-time perfusion CT (versus SPECT) had 86% (84%) sensitivity, 98% (92%) specificity, 94% (88%) positive predictive value, and 96% (92%) negative predictive value in comparison with perfusion MRI for the detection of myocardial perfusion defects. In Group B all myocardial segments were available for analysis. Compared with MRI, dual-energy myocardial perfusion CT (versus SPECT) had 93% (94%) sensitivity, 99% (98%) specificity, 92% (88%) positive predictive value, and 96% (94%) negative predictive value for detecting hypoperfused myocardial segments. Conclusion: Our results suggest the clinical feasibility of myocardial perfusion CT imaging in patients with acute chest pain. Compared to MRI and SPECT both, dynamic real-time perfusion CT and first-pass dual-energy perfusion CT showed good agreement for the detection of myocardial perfusion defects.

  11. Adenosine-stress dynamic real-time myocardial perfusion CT and adenosine-stress first-pass dual-energy myocardial perfusion CT for the assessment of acute chest pain: Initial results

    International Nuclear Information System (INIS)

    Weininger, Markus; Schoepf, U. Joseph; Ramachandra, Ashok; Fink, Christian; Rowe, Garrett W.; Costello, Philip; Henzler, Thomas

    2012-01-01

    Purpose: Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT in a clinical population with acute chest pain. Methods and materials: Myocardial stress perfusion CT was performed on twenty consecutive patients (15 men, 5 women; mean age 65 ± 8 years) who presented with acute chest pain and were clinically referred for stress/rest SPECT and cardiac MRI. Prior to CT each patient was randomly assigned either to Group A or to Group B in a consecutive order (10 patients per group). Group A underwent adenosine-stress dynamic real-time myocardial perfusion CT using a novel “shuttle” mode on a 2nd generation dual-source CT. Group B underwent adenosine-stress first-pass dual-energy myocardial perfusion CT using the same CT scanner in dual-energy mode. Two experienced observers visually analyzed all CT perfusion studies. CT findings were compared with MRI and SPECT. Results: In Group A 149/170 myocardial segments (88%) could be evaluated. Real-time perfusion CT (versus SPECT) had 86% (84%) sensitivity, 98% (92%) specificity, 94% (88%) positive predictive value, and 96% (92%) negative predictive value in comparison with perfusion MRI for the detection of myocardial perfusion defects. In Group B all myocardial segments were available for analysis. Compared with MRI, dual-energy myocardial perfusion CT (versus SPECT) had 93% (94%) sensitivity, 99% (98%) specificity, 92% (88%) positive predictive value, and 96% (94%) negative predictive value for detecting hypoperfused myocardial segments. Conclusion: Our results suggest the clinical feasibility of myocardial perfusion CT imaging in patients with acute chest pain. Compared to MRI and SPECT both, dynamic real-time perfusion CT and first-pass dual-energy perfusion CT showed good agreement for the detection of myocardial perfusion defects.

  12. Frequency and severity of myocardial perfusion abnormalities using Tc-99m MIBI SPECT in cardiac syndrome X

    International Nuclear Information System (INIS)

    Saghari, Mohsen; Assadi, Majid; Eftekhari, Mohammad; Yaghoubi, Mohammad; Fard-Esfahani, Armaghan; Malekzadeh, Jan-Mohammad; Sichani, Babak Fallhi; Beiki, Davood; Takavar, Abbas

    2006-01-01

    Cardiac syndrome X is defined by a typical angina pectoris with normal or near normal (stenosis <40%) coronary angiogram with or without electrocardiogram (ECG) change or atypical angina pectoris with normal or near normal coronary angiogram plus a positive none-invasive test (exercise tolerance test or myocardial perfusion scan) with or without ECG change. Studies with myocardial perfusion imaging on this syndrome have indicated some abnormal perfusion scan. We evaluated the role of myocardial perfusion imaging (MPI) and also the severity and extent of perfusion abnormality using Tc-99m MIBI Single Photon Emission Computed Tomography (SPECT) in these patients. The study group consisted of 36 patients with cardiac syndrome X. The semiquantitative perfusion analysis was performed using exercise Tc-99m MIBI SPECT. The MPI results were analyzed by the number, location and severity of perfusion defects. Abnormal perfusion defects were detected in 13 (36.10%) cases, while the remaining 23 (63.90%) had normal cardiac imaging. Five of 13 (38.4%) abnormal studies showed multiple perfusion defects. The defects were localized in the apex in 3, apical segments in 4, midventricular segments in 12 and basal segments in 6 cases. Fourteen (56%) of all abnormal segments revealed mild, 7(28%) moderate and 4 (16%) severe reduction of tracer uptake. No fixed defects were identified. The vessel territories were approximately the same in all subjects. The Exercise treadmill test (ETT) was positive in 25(69%) and negative in 11(30%) patients. There was no consistent pattern as related to the extent of MPI defects or exercise test results. Our study suggests that multiple perfusion abnormalities with different levels of severity are common in cardiac syndrome X, with more than 30 % of these patients having at least one abnormal perfusion segment. Our findings suggest that in these patients microvascular angina is probably more common than is generally believed

  13. The clinical value of pulmonary perfusion imaging complicated with pulmonary embolism in children of nephrotic syndrome

    International Nuclear Information System (INIS)

    Lin Jun; Chen Ning; Miao Weibing; Peng Jiequan; Jiang Zhihong; Wu Jing

    2001-01-01

    To investigate the clinical features of complicated with pulmonary embolism nephrotic syndrome in children. 99m Tc-MAA pulmonary perfusion imaging was performed on 30 nephrotic syndrome in children with elevated plasma D-dimer. Results shown that 14 of 30 patients were found to have pulmonary embolism (46.7%). Pulmonary perfusion imaging showed an involvement of 1 pulmonary segment in 3 cases, 2 segments in 2 cases and over 3 segments in other 9 cases. Among them, there were 7 segments involved in one case. After two weeks of heparin anti-coagulative therapy, most cases showed a recovery. The result of this study suggested that pulmonary embolism is a common complication of nephrotic syndrome. Pulmonary perfusion imaging is simple, effective and accurate method for the diagnosis of pulmonary embolism, and it also can help to assess the value of clinical therapy

  14. PET imaging of cerebral perfusion and oxygen metabolism in stroke

    Energy Technology Data Exchange (ETDEWEB)

    Pointon, O.; Yasaka, M.; Berlangieri, S.U.; Newton, M.R.; Thomas, D.L.; Chan, C.G.; Egan, G.F.; Tochon-Danguy, H.J.; O``Keefe, G.; Donnan, G.A.; McKay, W.J. [Austin Hospital, Melbourne, VIC (Australia). Centre for PET and Depts of Nuclear Medicine and Neurology

    1998-03-01

    Full text: Stroke remains a devastating clinical event with few therapeutic options. In patients with acute stroke, we studied the cerebral perfusion and metabolic patterns with {sup 15}O-CO{sub 2} or H{sub 2}O and {sup 15}O-O{sub 2} positron emission tomography and correlated these findings to the clinical background. Forty three patients underwent 45 studies 0-23 days post-stroke (mean 7 days). Fifteen patients showed luxury perfusion (Group A), 10 had matched low perfusion and metabolism (B) and 3 showed mixed pattern including an area of misery perfusion (C). Seventeen showed no relevant abnormality (D) and there were no examples of isolated misery perfusion. Twelve of the 15 in Group A had either haemorrhagic transformation on CT, re-opening on angiography, or a cardioembolic mechanism. In contrast only 5/10 in Group B, 0/3 in Group C and 2/17 in Group D had these features. Although 7/10 in group B had moderate or large size infarcts on CT the incidence of haemorrhagic transformation was low (2/10) and significant carotid stenoses were more common in those studied (5/8) compared with the other groups. Misery perfusion was not seen beyond five days. Thus, luxury perfusion seems to be related to a cardio-embolic mechanism or reperfusion. Matched low perfusion and metabolism was associated with a low rate of haemorrhagic transformation despite a high incidence of moderate to large size infarcts. Misery perfusion is an early phenomenon in the evolution of ischaemic stroke.

  15. Hydrogen ion changes and contractile behavior in the perfused rat heart

    NARCIS (Netherlands)

    Cingolani, H.E.; Maas, A.H.J.; Zimmerman, A.N.E.; Meijler, F.L.

    1975-01-01

    The effect of acid-base alterations was analyzed using isolated rat hearts perfused at constant coronary perfusion pressure, and stimulated to contract at constant rate. The amount of shortening in the major axis and its derivative were measured to assess myocardial contractility. Both the

  16. Regional glucose utilization in infarcted and remote myocardium: its relation to coronary anatomy and perfusion.

    Science.gov (United States)

    Fragasso, G; Chierchia, S L; Landoni, C; Lucignani, G; Rossetti, E; Sciammarella, M; Vanoli, G E; Fazio, F

    1998-07-01

    We studied the relationship between coronary anatomy, perfusion and metabolism in myocardial segments exhibiting transient and persistent perfusion defects on stress/rest 99Tcm-MIBI single photon emission tomography in 35 patients (31 males, 4 females, mean age 56 +/- 7 years) with a previous myocardial infarction. Quantitative coronary angiography and assessment of myocardial perfusion reserve and glucose metabolism were performed within 1 week of one another. Perfusion was assessed by SPET after the intravenous injection of 740 MBq of 99Tcm-MIBI at rest and after exercise. Regional myocardial glucose metabolism was assessed by position emission tomography at rest (200 MBq of 18F-2-deoxyglucose, FDG) after an overnight fast with no glucose loading. All 35 patients exhibited persistent perfusion defects consistent with the clinically identified infarct site, and 27 (77%) also showed various degrees of within-infarct FDG uptake; 11 patients developed exercise-induced transient perfusion defects within, or in the vicinity of, 15 infarct segments and resting FDG uptake was present in 10 of these segments (67%). Five patients also showed exercise-induced transient perfusion defects in nine segments remote from the site of infarct: resting FDG uptake was present in six of these regions (67%). Finally, nine patients had increased glucose uptake in non-infarcted regions not showing transient perfusion defects upon exercise testing and perfused by coronary arteries with only minor irregularities. Our results confirm the presence of viable tissue in a large proportion of infarct sites. Moreover, FDG uptake can be seen in regions perfused by coronary arteries showing minor irregularities, not necessarily resulting in detectable transient perfusion defects on a MIBI stress scan. Since the clinical significance of such findings is not clear, further studies should be conducted to assess the long-term evolution of perfusion, function and metabolism in non

  17. Perfusion based cell culture chips

    DEFF Research Database (Denmark)

    Heiskanen, Arto; Emnéus, Jenny; Dufva, Martin

    2010-01-01

    Performing cell culture in miniaturized perfusion chambers gives possibilities to experiment with cells under near in vivo like conditions. In contrast to traditional batch cultures, miniaturized perfusion systems provide precise control of medium composition, long term unattended cultures...... and tissue like structuring of the cultures. However, as this chapter illustrates, many issues remain to be identified regarding perfusion cell culture such as design, material choice and how to use these systems before they will be widespread amongst biomedical researchers....

  18. Active Segmentation.

    Science.gov (United States)

    Mishra, Ajay; Aloimonos, Yiannis

    2009-01-01

    The human visual system observes and understands a scene/image by making a series of fixations. Every fixation point lies inside a particular region of arbitrary shape and size in the scene which can either be an object or just a part of it. We define as a basic segmentation problem the task of segmenting that region containing the fixation point. Segmenting the region containing the fixation is equivalent to finding the enclosing contour- a connected set of boundary edge fragments in the edge map of the scene - around the fixation. This enclosing contour should be a depth boundary.We present here a novel algorithm that finds this bounding contour and achieves the segmentation of one object, given the fixation. The proposed segmentation framework combines monocular cues (color/intensity/texture) with stereo and/or motion, in a cue independent manner. The semantic robots of the immediate future will be able to use this algorithm to automatically find objects in any environment. The capability of automatically segmenting objects in their visual field can bring the visual processing to the next level. Our approach is different from current approaches. While existing work attempts to segment the whole scene at once into many areas, we segment only one image region, specifically the one containing the fixation point. Experiments with real imagery collected by our active robot and from the known databases 1 demonstrate the promise of the approach.

  19. Accuracy and feasibility of dynamic contrast-enhanced 3D MR imaging in the assessment of lung perfusion: comparison with Tc-99 MAA perfusion scintigraphy

    International Nuclear Information System (INIS)

    Yilmaz, E.; Akkoclu, A.; Degirmenci, B.; Cooper, R.A.; Sengun, B.; Gulcu, A.; Osma, E.; Ucan, E.S.

    2005-01-01

    AIM: The aim of this study was to correlate findings of perfusion magnetic resonance imaging (MRI) and perfusion scintigraphy in cases where there was a suspicion of abnormal pulmonary vasculature, and to evaluate the usefulness of MRI in the detection of perfusion deficits of the lung. METHODS: In all, 17 patients with suspected abnormality of the pulmonary vasculature underwent dynamic contrast-enhanced MRI. T1-weighted 3D fast-field echo pulse sequences were obtained (TR/TE 3.3/1.58 ms; flip angle 30 deg ; slice thickness 12 to 15 mm). The dynamic study was acquired in the coronal plane following administration of 0.1 mmol/kg gadopentetate dimeglumine. A total of 8 to 10 sections repeated 20 to 25 times at intervals of 1 s were performed. Perfusion lung scintigraphy was carried out a maximum of 48 h before the MR examination in all cases. Two radiologists, who were blinded to the clinical data and results of other imaging methods, reviewed all coronal sections. MR perfusion images were independently assessed in terms of segmental or lobar perfusion defects in the 85 lobes of the 17 individuals, and the findings were compared with the results of scintigraphy. RESULTS: Of the 17 patients, 8 were found to have pulmonary emboli, 2 chronic obstructive pulmonary disease with emphysema, 2 bullous emphysema, 2 Takayasu arteritis and 1 had a hypoplastic pulmonary artery. Pulmonary perfusion was completely normal in 2 cases. In 35 lobes, perfusion defects were detected using both methods, in 4 with MR alone and in 9 only with scintigraphy. There was good agreement between MRI and scintigraphy findings (kappa=0.695). CONCLUSION: Pulmonary perfusion MRI is a new alternative to scintigraphy in the evaluation of pulmonary perfusion for various lung disorders. In addition, this technique allows measurement and quantification of pulmonary perfusion abnormalities

  20. Production of acetone and conversion of acetone to acetate in the perfused rat liver

    International Nuclear Information System (INIS)

    Gavino, V.C.; Somma, J.; Philbert, L.; David, F.; Garneau, M.; Belair, J.; Brunengraber, H.

    1987-01-01

    The utilization of millimolar concentrations of [2- 14 C]acetone and the production of acetone from acetoacetate were studied in perfused livers from 48-h starved rats. We devised a procedure for determining, in a perfused liver system, the first-order rate constant for the decarboxylation of acetoacetate (0.29 +/- 0.09 h-1, S.E., n = 8). After perfusion of livers with [2- 14 C]acetone, labeled acetate was isolated from the perfusion medium and characterized as [1- 14 C]acetate. No radioactivity was found in lactate or 3-hydroxybutyrate. After 90 min of perfusion with [2- 14 C]acetone, the specific activity of acetate was 30 +/- 4% (n = 13) of the initial specific activity of acetone. We conclude that, in perfused livers from 2-day starved rats, acetone metabolism occurs for the most part via free acetate

  1. Gammagraphy of cerebral perfusion

    International Nuclear Information System (INIS)

    Vazquez, Silvia

    2003-01-01

    Important aspects of the gammagraphy of cerebral perfusion and the diverse clinical applications in the neurological diseases are comment in this article. We focus in the usefulness of the photon emission cerebral tomography (SPECT) and its capacity to cross the hemato encephalic barrier through the use of radiopharmacons like 99 mTc-H M-PAO and 99mTc-EDC, thus managing to offer functional data on the captantes neurons of the radiopharmacon. The clinical applications of SPECT are studied; cerebrovascular disease, transient ischemic attacks, dementias, Alzheimer disease, as well as other neurological diseases are referred. (The author)

  2. Myocardial perfusion abnormalities in asymptomatic patients with systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Hosenpud, J.D.; Montanaro, A.; Hart, M.V.; Haines, J.E.; Specht, H.D.; Bennett, R.M.; Kloster, F.E.

    1984-01-01

    Accelerated coronary artery disease and myocardial infarction in young patients with systemic lupus erythematosus is well documented; however, the prevalence of coronary involvement is unknown. Accordingly, 26 patients with systemic lupus were selected irrespective of previous cardiac history to undergo exercise thallium-201 cardiac scintigraphy. Segmental perfusion abnormalities were present in 10 of the 26 studies (38.5 percent). Five patients had reversible defects suggesting ischemia, four patients had persistent defects consistent with scar, and one patient had both reversible and persistent defects in two areas. There was no correlation between positive thallium results and duration of disease, amount of corticosteroid treatment, major organ system involvement or age. Only a history of pericarditis appeared to be associated with positive thallium-201 results (p less than 0.05). It is concluded that segmental myocardial perfusion abnormalities are common in patients with systemic lupus erythematosus. Whether this reflects large-vessel coronary disease or small-vessel abnormalities remains to be determined

  3. Segmentation: Identification of consumer segments

    DEFF Research Database (Denmark)

    Høg, Esben

    2005-01-01

    It is very common to categorise people, especially in the advertising business. Also traditional marketing theory has taken in consumer segments as a favorite topic. Segmentation is closely related to the broader concept of classification. From a historical point of view, classification has its...... origin in other sciences as for example biology, anthropology etc. From an economic point of view, it is called segmentation when specific scientific techniques are used to classify consumers to different characteristic groupings. What is the purpose of segmentation? For example, to be able to obtain...... a basic understanding of grouping people. Advertising agencies may use segmentation totarget advertisements, while food companies may usesegmentation to develop products to various groups of consumers. MAPP has for example investigated the positioning of fish in relation to other food products...

  4. Segmental Vitiligo.

    Science.gov (United States)

    van Geel, Nanja; Speeckaert, Reinhart

    2017-04-01

    Segmental vitiligo is characterized by its early onset, rapid stabilization, and unilateral distribution. Recent evidence suggests that segmental and nonsegmental vitiligo could represent variants of the same disease spectrum. Observational studies with respect to its distribution pattern point to a possible role of cutaneous mosaicism, whereas the original stated dermatomal distribution seems to be a misnomer. Although the exact pathogenic mechanism behind the melanocyte destruction is still unknown, increasing evidence has been published on the autoimmune/inflammatory theory of segmental vitiligo. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Prognostic Value of Normal Perfusion but Impaired Left Ventricular Function in the Diabetic Heart on Quantitative Gated Myocardial Perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hwanjeong; Choi, Sehun; Han, Yeonhee [Research Institute of Chonbuk National Univ. Medical School and Hospitial, Jeonju (Korea, Republic of); Lee, Dong Soo; Lee, Hoyoung; Chung, Junekey [Seoul National Univ., Seoul (Korea, Republic of)

    2013-09-15

    This study aimed at identifying the predictive parameters on quantitative gated myocardial perfusion single-photon emission computed tomography (QG-SPECT) in diabetic patients with normal perfusion but impaired function. Methods Among the 533 consecutive diabetic patients, 379 patients with normal perfusion on rest Tl-201/dipyridamole-stress Tc-{sup 99m} sestamibi Gated SPECT were enrolled. Patients were grouped into those with normal post-stress left ventricular function (Group I) and those with impaired function (EF <50 or impaired regional wall motion, Group II). We investigated cardiac events and cause of death by chart review and telephone interview. Survival analysis and Cox proportional hazard model analysis were performed. Between the Group I and II, cardiac events as well as chest pain symptoms, smoking, diabetic complications were significantly different (P<0.05). On survival analysis, event free survival rate in Group II was significantly lower than in Group I (P=0.016). In univariate Cox proportional hazard analysis on overall cardiac event, Group (II over I), diabetic nephropathy, summed motion score (SMS), summed systolic thickening score (STS), numbers of abnormal segmental wall motion and systolic thickening predicted more cardiac events (P<0.05). Multivariate analysis showed that STS was the only independent predictor cardiac event. The functional parameter, especially summed systolic thickening score on QG-SPECT had prognostic values, despite normal perfusion, in predicting cardiac events in diabetic patients, and QG-SPECT provides clinically useful risk stratification in diabetic patients with normal perfusion.

  6. A new clinical tool for the quantification of myocardial CT perfusion imaging in patients with suspected Ischemic Heart Disease

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Muñoz, A.; Dux-Santoy Hurtado, L.; Rodriguez Palomares, J.L.; Piella Fenoy, G.

    2016-07-01

    In the clinical practice, the evaluation of myocardial perfusion by using Computed Tomography (CT) Imaging is usually performed visually or semi-quantitatively. The scarcity of quantitative perfusion data not always allows a proper diagnose of patients which are suspected of suffering from some diseases, such as Ischemic Heart Disease (IHD). In this work, a clinical tool for the automatic quantification of myocardial perfusion in patients with suspected IHD is proposed. Myocardial perfusion is assessed based on a combined diagnosis protocol (CT/CTP protocol) which involves the acquisition of two contrastenhanced CT images, one obtained at rest and another acquired under pharmacological stress. The clinical tool allows the automatic quantification of perfusion in different myocardial segments defined according to the 16-AHA-segmentation model of the left ventricle, by providing the mean of Hounsfield Units in those regions. Based on this analysis, the clinicians can compare the values at baseline and at hyperemia, and they can better determine hypoperfusion defects in patients with IHD. The validation of the clinical tool was performed by comparing automatic and manual perfusion measurements of 10 patients with suspected IHD who were previously assessed with Single Photon Emission Computed Tomography (SPECT) for perfusion analysis. A strong linear correlation was found between the automatic and manual results. Afterwards, perfusion defects obtained from CT/CTP protocol were compared to perfusion defects from SPECT, to assess the applicability of this clinical tool for the diagnosis of IHD. (Author)

  7. Influence of revascularization on myocardial perfusion, metabolism and function

    International Nuclear Information System (INIS)

    Kropp, Joachim; Krois, Markus; Eichhorn, Bernd; Fehske, Wolfgang; Likungu, James; Kirchhoff, P.G.; Luederitz, Berndt; Biersack, Hans-Juergen; Knapp, F.F. Jr.

    1993-01-01

    Thirty-nine patients with coronary artery disease (CAD) were investigated with sequential SPECT-scintigraphy after administration of 200 MBq of 15-(p-[I-123]iodophenyl)pentadecanoic acid (IPPA) at peak submaximal exercise. Twenty patients underwent coronary angioplasty (PTCA) from which 14 had control coronary arteriography (CA) and left ventricular cineventriculography (LVCV). Nineteen patients underwent bypass graft surgery (ACB) and stress sonography. Semi-quantification of uptake (Up, related to perfusion) and turnover (Tr, linked to metabolism) was obtained by segmental comparison of oblique slices. About 90% of the reperfused myocardial segments in the PTCA-group and 76% in the ACB-group showed an improvement of uptake after therapy (RUp). Out of these, 50% and 66% exhibited increased turnover (RTr) after PTCA or ACB, respectively. The remaining segments had persistingly pathologic RTr indicating a dissociation of improvement of perfusion and metabolism after therapy. Pathologic RTr was highly correlated with regional wall motion abnormalities (RWMA) after therapy in both groups. In the ACB-group improvement in RTr was correlated with improved RWM at rest and stress in 86% and 92%, respectively, whereas no improvement in RTr was correlated with impared function in 100% and 52%, respectively. IPPA-studies show potential to provide information about changes of perfusion and metabolism after reperfusion and IPPA-turnover is a good predictor of the pattern of contractile function. (author)

  8. Brain perfusion: computed tomography applications

    International Nuclear Information System (INIS)

    Miles, K.A.

    2004-01-01

    Within recent years, the broad introduction of fast multi-detector computed tomography (CT) systems and the availability of commercial software for perfusion analysis have made cerebral perfusion imaging with CT a practical technique for the clinical environment. The technique is widely available at low cost, accurate and easy to perform. Perfusion CT is particularly applicable to those clinical circumstances where patients already undergo CT for other reasons, including stroke, head injury, subarachnoid haemorrhage and radiotherapy planning. Future technical developments in multi-slice CT systems may diminish the current limitations of limited spatial coverage and radiation burden. CT perfusion imaging on combined PET-CT systems offers new opportunities to improve the evaluation of patients with cerebral ischaemia or tumours by demonstrating the relationship between cerebral blood flow and metabolism. Yet CT is often not perceived as a technique for imaging cerebral perfusion. This article reviews the use of CT for imaging cerebral perfusion, highlighting its advantages and disadvantages and draws comparisons between perfusion CT and magnetic resonance imaging. (orig.)

  9. Perfusion CT in acute stroke

    International Nuclear Information System (INIS)

    Eckert, Bernd; Roether, Joachim; Fiehler, Jens; Thomalla, Goetz

    2015-01-01

    Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

  10. Placental perfusion - a human alternative

    DEFF Research Database (Denmark)

    Mose, Tina; Knudsen, Lisbeth E

    2006-01-01

    Foetal exposures to environmental and medicinal products have impact on the growth of the foetus (e.g. cigarette smoke) and development of organs (e.g. methylmercury and Thalidomide). Perfusion studies of the human term placenta enable investigation of placental transport of chemical substances...... between the mother and foetus. Dual perfusion of a single cotyledon in the human placenta can contribute to a better understanding of the placental barrier, transport rate and mechanisms of different substances and placental metabolism. The perfusion system has recently been established in Copenhagen...

  11. 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.

  12. Diabetes patients show different time-course of myocardial perfusion improvement after coronary artery bypass grafting

    International Nuclear Information System (INIS)

    Lee, J. J.; Seok, J. W.; Eo, J. S.

    2005-01-01

    Diabetes mellitus is an independent risk factor of cardiovascular disease. Diabetes is known to cause microangiopathy. The microangiopathy is hardly detectable on the coronary angiography. Myocardial perfusion imaging shows the resultant perfusion status which reflects the microangiopathy. For patients who underwent revascularization, the microangiopathy could affect the myocardial perfusion improvement. Diabetes patients probably experience the different myocardial perfusion improvement as compared to the non-diabetes patients although they have similar angiographic findings. The aim of this study is to find out whether there is a time-course difference of perfusion improvement between the diabetes and non diabetes patients who showed patent angiographic findings after coronary artery grafting surgery (CABG). A total of 129 patients who underwent coronary artery bypass grafting surgery were enrolled in this study. Myocardial SPECTs performed at previous, short-term (3 month), and mid-term (1 year) to CABG. One-year follow up angiography was done 411±121 days after surgery. Graft patency was determined according to the FitzGibbon et al. Segments were assigned to vascular territories using a 20 segment model. The segments of excellent patency were included in this study. Time course differences of concerned segments were analyzed using RMANOVA. The number of segments enrolled was 764 of diabetes and 1083 of non-diabetes. At short-term follow up, reversibility score was 2.8±8.1% in diabetes and 0.3±7.5% in non-diabetes. At long-term follow up, reversibility score was 1.8±8.0% in diabetes and 0.1±7.3% in non-diabetes. The time-course of reversibility score was significantly different between the diabetes and non diabetes (p<0.001) Diabetic segments showed high residual reversibility score than non-diabetic segments after CABG although the angiographic finding was patent in both groups. This result is maybe attributable to microangiopathy induced by diabetes

  13. Hepatic perfusion during hepatic artery infusion chemotherapy: Evaluation with perfusion CT and perfusion scintigraphy

    International Nuclear Information System (INIS)

    Miller, D.L.; Carrasquillo, J.A.; Lutz, R.J.; Chang, A.E.

    1989-01-01

    The standard method for the evaluation of hepatic perfusion during hepatic artery infusion (HAI) chemotherapy is planar hepatic artery perfusion scintigraphy (HAPS). Planar HAPS was performed with 2 mCi of [99mTc] macroaggregated albumin infused at 1 ml/min and compared with single photon emission CT (SPECT) HAPS and with a new study, CT performed during the slow injection of contrast material through the HAI catheter (HAI-CT). Thirteen patients underwent 16 HAI-CT studies, 14 planar HAPS studies, and 9 SPECT HAPS studies. In 13 of 14 studies (93%) HAI-CT and planar HAPS were in complete agreement as to the perfusion pattern of intrahepatic metastases and normal liver. In nine studies where all modalities were performed, the findings identified by HAI-CT and planar HAPS agreed in all cases, whereas the results of two SPECT scans disagreed with the other studies. With respect to perfusion of individual metastases, 14 of 14 HAI-CT studies, 12 of 13 planar HAPS studies, and 9 of 9 SPECT HAPS studies correctly demonstrated the perfusion status of individual lesions as indicated by the pattern of changes in tumor size determined on CT obtained before and after the perfusion studies. Hepatic artery infusion CT was superior for delineation of individual metastases, particularly small lesions, and for the evaluation of nonperfused portions of the liver. Planar HAPS detected extrahepatic perfusion in four patients, and this was not detected by HAI-CT. We conclude that HAI-CT and scintigraphy are complementary techniques. Hepatic artery infusion CT has advantages for the evaluation of intrahepatic perfusion, and planar HAPS is superior to HAI-CT for the detection of extrahepatic perfusion

  14. The acropetal effects of indole-3-acetic acid in isolated shoot segments of Acer pseudoplatanus L. II. Possible regulation by a vectorial fieid of auxin waves

    Directory of Open Access Journals (Sweden)

    Jacek A. Adamczyk

    2014-01-01

    Full Text Available The acropetal effects of auxin on elongation of axillary buds and on modulation of the wave-like pattern of basipetal efflux of natural auxin to agar from Acer pseudoplatanus L. shoots were studied. When synthetic IAA was applied to cut surfaces of one of two branches the elongation growth of buds situated on the opposite branch was retarded, suggesting regulation independent of the direct action of the molecules of the applied IAA. Oscillations in basipetal transport of natural auxin along the stem segments were observed corroborating the results of other authors using different tree species. Apical application of synthetic IAA for 1 hour to the lateral branch caused a phase shift of the wave-like pattern of basipetal efflux of natural auxin, when the stem segment above the treated branch was sectioned. The same effect was observed evoked by the laterally growing branch which is interpreted as an effect of natural auxin produced by the actively growing shoot. These modulations could be propagated acropetally at a rate excluding direct action of auxin molecules at the sites of measurement. The results seem to corroborate the hypothesis suggesting that auxin is involved in acropetal regulation of shoot apex growth through its effect upon modulation of the vectorial field which arises when the auxin-waves translocate in cambium.

  15. Mixed segmentation

    DEFF Research Database (Denmark)

    Hansen, Allan Grutt; Bonde, Anders; Aagaard, Morten

    content analysis and audience segmentation in a single-source perspective. The aim is to explain and understand target groups in relation to, on the one hand, emotional response to commercials or other forms of audio-visual communication and, on the other hand, living preferences and personality traits...

  16. Relation between lung perfusion defects and intravascular clots in acute pulmonary thromboembolism: assessment with breath-hold SPECT-CT pulmonary angiography fusion images.

    Science.gov (United States)

    Suga, Kazuyoshi; Yasuhiko, Kawakami; Iwanaga, Hideyuki; Tokuda, Osamu; Matsunaga, Naofumi

    2008-09-01

    The relation between lung perfusion defects and intravascular clots in acute pulmonary thromboembolism (PTE) was comprehensively assessed on deep-inspiratory breath-hold (DIBrH) perfusion SPECT-computed tomographic pulmonary angiography (CTPA) fusion images. Subjects were 34 acute PTE patients, who had successfully performed DIBrH perfusion SPECT using a dual-headed SPECT and a respiratory tracking system. Automated DIBrH SPECT-CTPA fusion images were used to assess the relation between lung perfusion defects and intravascular clots detected by CTPA. DIBrH SPECT visualized 175 lobar/segmental or subsegmental defects in 34 patients, and CTPA visualized 61 intravascular clots at variable locations in 30 (88%) patients, but no clots in four (12%) patients. In 30 patients with clots, the fusion images confirmed that 69 (41%) perfusion defects (20 segmental, 45 subsegmental and 4 lobar defects) of total 166 defects were located in lung territories without clots, although the remaining 97 (58%) defects were located in lung territories with clots. Perfusion defect was absent in lung territories with clots (one lobar branch and three segmental branches) in four (12%) of these patients. In four patients without clots, nine perfusion defects including four segmental ones were present. Because of unexpected dissociation between intravascular clots and lung perfusion defects, the present fusion images will be a useful adjunct to CTPA in the diagnosis of acute PTE.

  17. Hydrostatic determinants of cerebral perfusion

    International Nuclear Information System (INIS)

    Wagner, E.M.; Traystman, R.J.

    1986-01-01

    We examined the cerebral blood flow response to alterations in perfusion pressure mediated through decreases in mean arterial pressure, increases in cerebrospinal fluid (CSF) pressure, and increases in jugular venous (JV) pressure in 42 pentobarbital anesthetized dogs. Each of these three pressures was independently controlled. Cerebral perfusion pressure was defined as mean arterial pressure minus JV or CSF pressure, depending on which was greater. Mean hemispheric blood flow was measured with the radiolabeled microsphere technique. Despite 30-mm Hg reductions in mean arterial pressure or increases in CSF or JV pressure, CBF did not change as long as the perfusion pressure remained greater than approximately 60 mm Hg. However, whenever perfusion pressure was reduced to an average of 48 mm Hg, cerebral blood flow decreased 27% to 33%. These results demonstrate the capacity of the cerebral vascular bed to respond similarly to changes in the perfusion pressure gradient obtained by decreasing mean arterial pressure, increasing JV pressure or increasing CSF pressure, and thereby support the above definition of cerebral perfusion pressure

  18. Discrepancy between microsphere and diffusible tracer estimates of perfusion to ischemic myocardium

    International Nuclear Information System (INIS)

    Yoshida, S.; Akizuki, S.; Gowski, D.; Downey, J.M.

    1985-01-01

    This study critically tests the ability of microspheres to accurately measure perfusion to ischemic myocardium. The left anterior descending coronary artery was cannulated and perfused with arterial blood. The perfusion line was clamped, and a sidearm between the clamp and the cannula was opened to the atmosphere, allowing blood to flow retrograde from the distal segment of the artery. Measurement of regional blood flow during retrograde flow diversion with 15-micron microspheres revealed essentially zero flow to the perfused segment (0.005 ml X min-1 X g-1). Measurements under the same conditions by either 86 Rb uptake or 133 Xe washout revealed that an appreciable perfusion of the tissue persisted during retrograde flow diversion (0.043 and 0.11 ml X min-1 X g-1, respectively, for the 2 methods). Thus, the authors have identified a condition during which microspheres indicate zero flow to the tissue but diffusible tracers can both be washed in and washed out at a brisk rate. They conclude that with simple occlusion there is a hidden component of perfusion to an ischemic zone that cannot be measured by microspheres, causing them to underestimate flow by about 25% in that condition

  19. Simultaneous maximal exercise radionuclide angiography and thallium stress perfusion imaging

    International Nuclear Information System (INIS)

    Narahara, K.A.; Mena, I.; Maublant, J.C.; Brizendine, M.; Criley, J.M.

    1984-01-01

    Gold-195m is a new ultra-short-lived radionuclide that can be used for cardiac studies. Accurate, reproducible ejection fraction and ventricular wall motion studies can be obtained from first-transit angiography using commercially available imaging and image-processing equipment. The short half-life of gold-195m (30.5 seconds) makes simultaneous dual isotope imaging possible and substantially reduces the radiation exposure from the isotope angiography. The feasibility and possible benefits of performing dual radionuclide studies were evaluated during a single exercise stress test in 24 subjects with known coronary artery disease (CAD) and in 20 normal volunteers. High-quality first-transit angiograms were obtained in all subjects. An 83% sensitivity and 95% specificity for detecting CAD with thallium-201 imaging was noted in this investigation, suggesting that its diagnostic accuracy was not altered by simultaneous dual isotone imaging. When segmental left ventricular (LV) wall motion was compared with thallium-201 perfusion imaging, divergent results were noted in 15 of 44 subjects. An analysis of the ejection fraction (EF) results at rest and stress provided additional information that could be useful in assessing the clinical significance of such differences in segmental wall motion and perfusion. Simultaneous dual isotope imaging appears to be appropriate for situations in which both LV perfusion and function require evaluation. The use of gold-195m allows such information to be obtained from a single exercise test and can thereby reduce the cost and time required for noninvasive evaluations of patients for CAD

  20. Patient-specific coronary blood supply territories for quantitative perfusion analysis

    Science.gov (United States)

    Zakkaroff, Constantine; Biglands, John D.; Greenwood, John P.; Plein, Sven; Boyle, Roger D.; Radjenovic, Aleksandra; Magee, Derek R.

    2018-01-01

    Abstract Myocardial perfusion imaging, coupled with quantitative perfusion analysis, provides an important diagnostic tool for the identification of ischaemic heart disease caused by coronary stenoses. The accurate mapping between coronary anatomy and under-perfused areas of the myocardium is important for diagnosis and treatment. However, in the absence of the actual coronary anatomy during the reporting of perfusion images, areas of ischaemia are allocated to a coronary territory based on a population-derived 17-segment (American Heart Association) AHA model of coronary blood supply. This work presents a solution for the fusion of 2D Magnetic Resonance (MR) myocardial perfusion images and 3D MR angiography data with the aim to improve the detection of ischaemic heart disease. The key contribution of this work is a novel method for the mediated spatiotemporal registration of perfusion and angiography data and a novel method for the calculation of patient-specific coronary supply territories. The registration method uses 4D cardiac MR cine series spanning the complete cardiac cycle in order to overcome the under-constrained nature of non-rigid slice-to-volume perfusion-to-angiography registration. This is achieved by separating out the deformable registration problem and solving it through phase-to-phase registration of the cine series. The use of patient-specific blood supply territories in quantitative perfusion analysis (instead of the population-based model of coronary blood supply) has the potential of increasing the accuracy of perfusion analysis. Quantitative perfusion analysis diagnostic accuracy evaluation with patient-specific territories against the AHA model demonstrates the value of the mediated spatiotemporal registration in the context of ischaemic heart disease diagnosis. PMID:29392098

  1. 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

  2. Compartmented pyruvate in perfused working heart

    International Nuclear Information System (INIS)

    Buenger, R.

    1985-01-01

    Pyruvate compartmentation and lactate dehydrogenase (LDH) were studied in isolated perfused working guinea pig hearts. The mean intracellular pyruvate (Pyr) contents increased with perfusate Pyr (0-2 mM) but varied only slightly with glucose (0-10 mM) and additional insulin (0.04-5 U/l), respectively. With 5-10 mM glucose plus 5 U/l insulin, but not with Pyr or lactate (Lac) as substrates, a near equilibrium between the LDH and the glycerol-3-phosphate dehydrogenase seemed to exist. Evidence for an inhibitory effect of Pyr on the activity of the LDH system of the perfused hearts was not obtained. With [U- 14 C]glucose as sole substrate, the specific activity of coronary venous Lac was near half that of precursor glucose. 14 CO 2 production was thus in quantitative agreement with rates of pyruvate oxidation that were determined as glucose uptake minus (Pyr + Lac) release. In contrast, with 0.2 mM [1- 14 C]Pyr plus 5 mM glucose, the ratio of 14 CO 2 production to specific activity of Lac overestimated Pyr oxidation judged from myocardial substrate balances and O 2 uptake, respectively; here, at least three pools of [ 14 C]HCO-3 and [ 14 C]lac, respectively, were kinetically demonstrable during washout of trace amounts of 14 C-labeled Pyr. Evidently, the specific activity of Lac was equivalent to that of mitochondrial oxidized Pyr provided [ 14 C]glucose was the sole or major precursor of cellular pyruvate. However, exogenously applied [1- 14 C]Pyr of high specific activity seemed to induce intracellular formation of both a highly and lowly labeled Pyr; the latter Pyr compartment did not seem in ready equilibrium with the cell physiologically prevailing highly labeled Pyr pool

  3. Prognostic Value of Quantitative Stress Perfusion Cardiac Magnetic Resonance.

    Science.gov (United States)

    Sammut, Eva C; Villa, Adriana D M; Di Giovine, Gabriella; Dancy, Luke; Bosio, Filippo; Gibbs, Thomas; Jeyabraba, Swarna; Schwenke, Susanne; Williams, Steven E; Marber, Michael; Alfakih, Khaled; Ismail, Tevfik F; Razavi, Reza; Chiribiri, Amedeo

    2018-05-01

    This study sought to evaluate the prognostic usefulness of visual and quantitative perfusion cardiac magnetic resonance (CMR) ischemic burden in an unselected group of patients and to assess the validity of consensus-based ischemic burden thresholds extrapolated from nuclear studies. There are limited data on the prognostic value of assessing myocardial ischemic burden by CMR, and there are none using quantitative perfusion analysis. Patients with suspected coronary artery disease referred for adenosine-stress perfusion CMR were included (n = 395; 70% male; age 58 ± 13 years). The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, aborted sudden death, and revascularization after 90 days. Perfusion scans were assessed visually and with quantitative analysis. Cross-validated Cox regression analysis and net reclassification improvement were used to assess the incremental prognostic value of visual or quantitative perfusion analysis over a baseline clinical model, initially as continuous covariates, then using accepted thresholds of ≥2 segments or ≥10% myocardium. After a median 460 days (interquartile range: 190 to 869 days) follow-up, 52 patients reached the primary endpoint. At 2 years, the addition of ischemic burden was found to increase prognostic value over a baseline model of age, sex, and late gadolinium enhancement (baseline model area under the curve [AUC]: 0.75; visual AUC: 0.84; quantitative AUC: 0.85). Dichotomized quantitative ischemic burden performed better than visual assessment (net reclassification improvement 0.043 vs. 0.003 against baseline model). This study was the first to address the prognostic benefit of quantitative analysis of perfusion CMR and to support the use of consensus-based ischemic burden thresholds by perfusion CMR for prognostic evaluation of patients with suspected coronary artery disease. Quantitative analysis provided incremental prognostic value to visual assessment and

  4. Orthodontic Treatment and Maxillary Anterior Segmental Distraction Osteogenesis of a Subject with Williams–Beuren Syndrome and Isolated Cleft Palate: A Long-Term Follow-Up from the Age of 5 to 24 Years

    Science.gov (United States)

    Shirota, Tatsuo; Adel, Mohamed; Takahashi, Masahiro; Haga, Shugo; Nagahama, Ryo; Nakashima, Misato; Furuhata, Mayu; Kamatani, Takaaki; Maki, Koutaro

    2017-01-01

    Williams–Beuren syndrome (WBS) is a rare multisystem disorder caused by a hemizygous deletion of the elastin gene on chromosome 7q11.23. WBS patients have characteristic skeletal features and dental anomalies accompanied by mental retardation, a friendly outgoing personality, and mild to moderate intellectual disability or learning problems. In this case report, we present the combined orthodontic and surgical treatment of a WBS patient with an isolated cleft palate through a long-term follow-up from the age of 5 to 24 years. During the period of active treatment, comprehensive orthodontic treatment combined with maxillary anterior segmental distraction osteogenesis and prosthetic treatment using dental implants were effective in dramatically improving the patient's malocclusion. The patient's mental abilities and the cooperation shown by the patient and her family were crucial for the success of this complex and long-term treatment course. PMID:28744380

  5. Orthodontic Treatment and Maxillary Anterior Segmental Distraction Osteogenesis of a Subject with Williams–Beuren Syndrome and Isolated Cleft Palate: A Long-Term Follow-Up from the Age of 5 to 24 Years

    Directory of Open Access Journals (Sweden)

    Tetsutaro Yamaguchi

    2017-01-01

    Full Text Available Williams–Beuren syndrome (WBS is a rare multisystem disorder caused by a hemizygous deletion of the elastin gene on chromosome 7q11.23. WBS patients have characteristic skeletal features and dental anomalies accompanied by mental retardation, a friendly outgoing personality, and mild to moderate intellectual disability or learning problems. In this case report, we present the combined orthodontic and surgical treatment of a WBS patient with an isolated cleft palate through a long-term follow-up from the age of 5 to 24 years. During the period of active treatment, comprehensive orthodontic treatment combined with maxillary anterior segmental distraction osteogenesis and prosthetic treatment using dental implants were effective in dramatically improving the patient’s malocclusion. The patient’s mental abilities and the cooperation shown by the patient and her family were crucial for the success of this complex and long-term treatment course.

  6. Reversible cold-induced abnormalities in myocardial perfusion and function in systemic sclerosis

    International Nuclear Information System (INIS)

    Alexander, E.L.; Firestein, G.S.; Weiss, J.L.; Heuser, R.R.; Leitl, G.; Wagner, H.N. Jr.; Brinker, J.A.; Ciuffo, A.A.; Becker, L.C.

    1986-01-01

    The effects of peripheral cold exposure on myocardial perfusion and function were studied in 13 patients with scleroderma without clinically evident myocardial disease. Ten patients had at least one transient, cold-induced, myocardial perfusion defect visualized by thallium-201 scintigraphy, and 12 had reversible, cold-induced, segmental left ventricular hypokinesis by two-dimensional echocardiography. The 10 patients with transient perfusion defects all had anatomically corresponding ventricular wall motion abnormalities. No one in either of two control groups (9 normal volunteers and 7 patients with chest pain and normal coronary arteriograms) had cold-induced abnormalities. This study is the first to show the simultaneous occurrence of cold-induced abnormalities in myocardial perfusion and function in patients with scleroderma. The results suggest that cold exposure in such patients may elicit transient reflex coronary vasoconstriction resulting in reversible myocardial ischemia and dysfunction. Chronic recurrent episodes of coronary spasm may lead to focal myocardial fibrosis

  7. Specific perfusion pattern in stress 201Tl myocardial scintigraphy of left main coronary artery disease

    International Nuclear Information System (INIS)

    Wakasugi, Shigetoshi; Shibata, Nobuhiko; Kobayashi, Tohru; Fudemoto, Yoshiyuki; Hasegawa, Yoshihisa; Nakano, Shunichi

    1986-01-01

    The usefulness of stress 201 Tl myocardial scintigraphy for identifying left main coronary artery disease was evaluated with data from 23 patients with 50% or more narrowing of the left main coronary artery and 56 patients with 75% or more narrowing of the major coronary arteries but without left main coronary artery involvement (no left main coronary artery disease). Quantitative evaluation of stress perfusion scintigrams in all five patients with narrowing of the left main coronary artery of 90% or more showed a characteristic perfusion pattern (left main pattern) of extensive homogeneous defect over the whole anterolateral segment and simultaneous defects in all radii of the high anteroseptal and high posterolateral segments. On the other hand, such a perfusion pattern was noted in only 1 of 18 patients with less than 90% stenosis of the left main coronary artery and in only 1 of 56 patients with no left coronary artery disease. (orig.)

  8. Characteristics of myocardial perfusion imaging and coronary artery angiography in patients of NIDDM complicated with AMI

    International Nuclear Information System (INIS)

    Zhao Peiqin; Zhao Jinhua; Qin Mingzhao; Dai HaoJie; Zhang Runwu; Xiao Fen

    2001-01-01

    Objective: To investigate the characteristic changes of myocardial perfusion imaging and coronary artery angiography in patients of acute myocardial infarction (AMI) with underlined type 2 diabetes mellitus. Methods: 25 type 2 diabetes mellitus patients were enrolled for having clinical manifestation of AMI. Ten inpatients with AMI of simple coronary heart disease origin were served as controls. All subjects underwent both myocardial perfusion imagings (resting and nitroglycerine invention) and coronary artery angiography. Results: Compared to controls (40%), type 2 diabetes mellitus + AMI group had higher rate of multivessel disease (60%). For type 2 diabetes mellitus + AMI patients, 129/400 segments (32.25%) showed fixed defect, 25/160 segments (15.62%) in controls. Conclusions: For type 2 diabetes mellitus + AMI group, myocardial perfusion defects are widely distributed and multivessel or severe stenosis is more often presented. Good correlation exists between abnormal segments and angiographic lesions in both the number of segments involved and the severity of the lesions. Radionuclide myocardial perfusion is therefore considered a useful screening test not inferior to angiography, especially for those who are not tolerant enough to undergoing angiography

  9. Patterns of disturbed myocardial perfusion in patients with coronary artery disease. Regional myocardial perfusion in angina pectoris

    International Nuclear Information System (INIS)

    Selwyn, A.P.; Forse, G.; Fox, K.; Jonathan, A.; Steiner, R.

    1981-01-01

    Fifty patients who presented with angina pectoris were studied to examine the disturbances of regional myocardial perfusion during stress. Each patient underwent 16-point precordial mapping of the ECG during an exercise test, and coronary and left ventricular angiography. Regional myocardial perfusion was assessed using an atrial pacing test and a short-lived radionuclide, krypton-81m. Eleven patients had negative exercise tests and uniform increases in myocardial activity of krypton-81m of 98 +/- 18.0% during pacing. Ten patients performed 30,000-43,000 J in positive exercise tests. These patients showed abnormal coronary anatomy and increases in myocardial activity of krypton-81m to remote and jeopardized myocardium at the onset of pacing. However, further pacing produced a decrease in activity in the affected segment of 68.0 +/- 9.0% accompanied by ST-segment depression and angina. Twelve patients achieved 26,000-32,000 J in positive exercise tests and had significant coronary artery disease. Atrial pacing produced increased activity of krypton-81m to remote myocardium. The jeopardized segment at first showed no change and then a decrease in regional activity of krypton-81m (89.0 +/- 17%) accompanied by ST-segment depression and chest pain. Seventeen patients achieved only 7000-22,000 J in positive exercise tests. These patients showed abnormal coronary anatomy and developed decreases in regional activity of krypton-81m to the affected segment of myocardium starting at the onset of atrial pacing and decreasing by 88 +/- 0 7.0% below control. We conclude that different patterns of disturbed myocardial distribution of krypton-81m are present during stress-induced ischemia in patients with coronary artery disease. There was a close temporal relationship between these disturbances and ST-segment depression

  10. Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

    International Nuclear Information System (INIS)

    Gimelli, Alessia; Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia; Marzullo, Paolo

    2016-01-01

    To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic "9"9"mTc-tetrofosmin and "1"2"3I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target. (orig.)

  11. Relationships between cardiac innervation/perfusion imbalance and ventricular arrhythmias: impact on invasive electrophysiological parameters and ablation procedures

    Energy Technology Data Exchange (ETDEWEB)

    Gimelli, Alessia [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Menichetti, Francesca; Soldati, Ezio; Liga, Riccardo; Vannozzi, Andrea; Bongiorni, Maria Grazia [University Hospital of Pisa, Cardio-Thoracic and Vascular Department, Pisa (Italy); Marzullo, Paolo [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); CNR, Institute of Clinical Physiology, Pisa (Italy)

    2016-12-15

    To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic {sup 99m}Tc-tetrofosmin and {sup 123}I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively. Off-line spatial co-registration of CZT perfusion and innervation data with the three-dimensional EAM reconstruction was performed in every patient. CZT revealed the presence of myocardial scar in 55 (20 %) segments. Of the viable myocardial segments, 131 (60 %) presented a preserved adrenergic innervation, while 86 (40 %) showed a significantly depressed innervation (i.e. innervation/perfusion mismatch). On EAM, the invasively measured intra-cavitary voltage was significantly lower in scarred segments than in viable ones (1.7 ± 1.5 mV vs. 4.0 ± 2.2 mV, P < 0.001). Interestingly, among the viable segments, those showing an innervation/perfusion mismatch presented a significantly lower intra-cavitary voltage than those with preserved innervation (1.9 ± 2.5 mV vs. 4.7 ± 2.3 mV, P < 0.001). Intra-cardiac ablation was performed in 63 (23 %) segments. On multivariate analysis, after correction for scar burden, the segments showing an innervation/perfusion mismatch remained the most frequent ablation targets (OR 5.6, 95 % CI 1.5-20.8; P = 0.009). In patients with VA, intra-cavitary electrical abnormalities frequently originate at the level of viable myocardial segments with depressed sympathetic innervation that frequently represents the ultimate ablation target

  12. Characterization of an Isolated Kidney's Vasculature for Use in Bio-Thermal Modeling

    Science.gov (United States)

    Payne, Allison H.; Parker, Dennis L.; Moellmer, Jeff; Roemer, Robert B.; Clifford, Sarah

    2007-05-01

    Accurate bio-thermal modeling requires site-specific modeling of discrete vascular anatomy. Presented herewith are several steps that have been developed to describe the vessel network of isolated canine and bovine kidneys. These perfused, isolated kidneys provide an environment to repeatedly test and improve acquisition methods to visualize the vascular anatomy, as well as providing a method to experimentally validate discrete vasculature thermal models. The organs are preserved using a previously developed methodology that keeps the vasculature intact, allowing for the organ to be perfused. It also allows for the repeated fixation and re-hydration of the same organ, permitting the comparison of various methods and models. The organ extraction, alcohol preservation, and perfusion of the organ are described. The vessel locations were obtained through a high-resolution time-of-flight (TOF) magnetic resonance angiography (MRA) technique. Sequential improvements of both the experimental setup used for this acquisition, as well as MR sequence development are presented. The improvements in MR acquisition and experimental setup improved the number of vessels seen in both the raw data and segmented images by 50%. An automatic vessel centerline extraction algorithm describes both vessel location and genealogy. Centerline descriptions also allows for vessel diameter and flow rate determination, providing valuable input parameters for the discrete vascular thermal model. Characterized vessels networks of both canine and bovine kidneys are presented. While these tools have been developed in an ex vivo environment, all steps can be applied to in vivo applications.

  13. Dynamic CT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

    2016-01-01

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  14. Dynamic CT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

    2016-10-15

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  15. Brookhaven segment interconnect

    International Nuclear Information System (INIS)

    Morse, W.M.; Benenson, G.; Leipuner, L.B.

    1983-01-01

    We have performed a high energy physics experiment using a multisegment Brookhaven FASTBUS system. The system was composed of three crate segments and two cable segments. We discuss the segment interconnect module which permits communication between the various segments

  16. Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension : Insights from a multicenter registry

    NARCIS (Netherlands)

    Vliegenthart, Rozemarijn; De Cecco, Carlo N.; Wichmann, Julian L.; Meinel, Felix G.; Pelgrim, Gert Jan; Tesche, Christian; Ebersberger, Ullrich; Pugliese, Francesca; Bamberg, Fabian; Choe, Yeon Hyeon; Wang, Yining; Schoepf, U. Joseph

    2016-01-01

    Background: To identify patients with early signs of myocardial perfusion reduction, a reference base for perfusion measures is needed. Objective: To analyze perfusion parameters derived from dynamic computed tomography perfusion imaging (CTPI) in patients with suspected coronary artery disease

  17. Automatic assessment of cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Stegmann, Mikkel Bille; Larsson, Henrik B.W.

    2004-01-01

    In this paper, a method based on Active Appearance Models (AAM) is applied for automatic registration of myocardial perfusion MRI. A semi-quantitative perfusion assessment of the registered image sequences is presented. This includes the formation of perfusion maps for three parameters; maximum up...

  18. Handwriting segmentation of unconstrained Oriya text

    Indian Academy of Sciences (India)

    Based on vertical projection profiles and structural features of Oriya characters, text lines are segmented into words. For character segmentation, at first, the isolated and connected (touching) characters in a word are detected. Using structural, topological and water reservoir concept-based features, characters of the word ...

  19. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    ... 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 ...

  20. Myocordial perfusion SPECT with dipyridamole stress test in cardiac syndrome X

    International Nuclear Information System (INIS)

    Czepczynski, R.; Smolarek, I.; Sowinski, J.; Rogacka, D.; Kazmierczak, M.; Wysocki, H.

    2006-01-01

    Cardiac syndrome X defines patients with typical anginal chest pain, a positive exercise ECG stress test and angiographically normal coronary arteries. Aim of this study was to evaluate the role of myocardial perfusion SPECT with dipyridamole stress in the diagnosis of cardiac syndrome X. Patients, methods: 68 patients with syndrome X aged 32 to 60 years were subjected to myocardial imaging using 99m Tc-MIBI according to the two-days protocol: at rest and after dipyridamole infusion. Semiquantitative evaluation of the images was based on the assessment of 99m Tc-MIBI uptake in 17 myocardial segments using a 5-points scale (0 point - normal uptake, 4 points - no uptake). Scores obtained in each segment were summed up, constituting the summed rest score (SRS) and summed stress score (SSS). Results: mean SRS was 7.9 ± 4.8 and mean SSS was 7.2 ± 4.4 (non-significant difference). Individual comparison of SRS and SSS values revealed three patterns of scintigraphic images: (1) in 25 patients (36.8%), a paradoxical improvement of perfusion at stress images was found, (2) in 23 patients (33.8%), the myocardial perfusion deteriorated after dipyridamole, (3) in 20 patients (29.4%), no significant change of the myocordial perfusion between rest and stress images occurred. Conclusions: in cardiac syndrome X, myocardial SPECT with dipyridamole stress shows different patterns of myocardial perfusion that reflects heterogeneity of this pathology. (orig.)

  1. Assessment of residual tissue viability by exercise testing in recent myocardial infarction: comparison of the electrocardiogram and myocardial perfusion scintigraphy.

    Science.gov (United States)

    Margonato, A; Ballarotto, C; Bonetti, F; Cappelletti, A; Sciammarella, M; Cianflone, D; Chierchia, S L

    1992-04-01

    The assessment of residual myocardial viability in infarcted areas is relevant for subsequent management and prognosis but requires expensive technology. To evaluate the possibility that simple, easily obtainable clinical markers may detect the presence of within-infarct viable tissue, the significance of exercise-induced ST elevation occurring in leads exploring the area of a recent Q wave myocardial infarction was assessed. Twenty-five patients with recent (less than 6 months) myocardial infarction were studied. All had angiographically documented coronary artery disease, diagnostic Q waves (n = 24) or negative T waves (n = 25) on the rest 12-lead electrocardiogram and exhibited during exercise greater than or equal to 1.5 mm ST segment elevation (n = 17) or isolated T wave pseudonormalization (n = 8) in the infarct-related leads. ST-T wave changes were reproduced in all patients during thallium-201 exercise myocardial scintigraphy. A fixed perfusion defect was observed in 24 of the 25 patients. A reversible defect was seen in 16 (94%) of 17 patients who exhibited transient ST elevation during exercise but in only 4 (50%) of the 8 patients who had only T wave pseudonormalization. In conclusion, in patients with recent myocardial infarction, analysis of simple ST segment variables obtained during exercise testing may allow a first-line discrimination of those who may potentially benefit from a revascularization procedure.

  2. 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

  3. Myocardial perfusion SPECT in a case of retropulmonary looping of left coronary artery in a baby after arterial switch surgery

    International Nuclear Information System (INIS)

    Padma, Subramanyam; Sundaram, Palaniswamy Shanmuga

    2014-01-01

    Pediatric myocardial perfusion imaging (MPI) is not a routine investigation in an Indian setting due to under referrals and logistic problems. However, MPI is a frequently performed and established modality of investigation in adults for the identification of myocardial ischemia and viability. We report myocardial perfusion scintigraphy in a case of retropulmonary looping of left coronary artery in a baby after arterial switch surgery. Adenosine stress MPI revealed a large infarct involving anterior segment with moderate reversible ischemia of the lateral left ventricular segment. Coronary angiogram later confirmed left main coronary artery ostial occlusion with retrograde collateral supply from dilated right coronary artery

  4. Contralateral thalamic hypoperfusion on brain perfusion SPECT

    International Nuclear Information System (INIS)

    Lee, Seok Mo; Bae, Sang Kyun; Yoo, Kyung Moo; Yum, Ha Yong

    2000-01-01

    Brain perfusion single photon emission computed tomography (SPECT) is useful for the localization of cerebrovascular lesion and sometimes reveals more definite lesion than radiologic imaging modality such as CT or MRI does. The purpose of this study was to evaluate the diagnostic usefulness of brain perfusion SPECT in patients with hemisensory impairment. Thirteen consecutive patients (M:F= 8:5, mean age = 48) who has hemisensory impairment were included. Brain perfusion SPECT was performed after intravenous injection of 1110 MBq of Tc-99m ECD. The images were obtained using a dual-head gamma camera with ultra-high resolution collimator. Semiquantitative analysis was performed after placing multiple ROIs on cerebral cortex, basal ganglia, thalamus and cerebellum. There were 10 patients with left hemisensory impairment and 3 patients with right-sided symptom. Only 2 patients revealed abnormal signal change in the thalamus on MRI. But brain perfusion SPECT showed decreased perfusion in the thalamus in 9 patients. Six patients among 10 patients with left hemisensory impairment revealed decreased perfusion in the contralateral thalamus on brain SPECT. The other 4 patients revealed no abnormality. Two patients among 3 patients with right hemisensory impairment also showed decreased perfusion in the contralateral thalamus on brain SPECT. One patients with right hemisensory impairment showed ipsilateral perfusion decrease. Two patients who had follow-up brain perfusion SEPCT after treatment revealed normalization of perfusion in the thalamus. Brain perfusion SPECT might be a useful tool in diagnosing patients with hemisensory impairment

  5. Magnetic resonance perfusion imaging without contrast media

    International Nuclear Information System (INIS)

    Martirosian, Petros; Graf, Hansjoerg; Schick, Fritz; Boss, Andreas; Schraml, Christina; Schwenzer, Nina F.; Claussen, Claus D.

    2010-01-01

    Principles of magnetic resonance imaging techniques providing perfusion-related contrast weighting without administration of contrast media are reported and analysed systematically. Especially common approaches to arterial spin labelling (ASL) perfusion imaging allowing quantitative assessment of specific perfusion rates are described in detail. The potential of ASL for perfusion imaging was tested in several types of tissue. After a systematic comparison of technical aspects of continuous and pulsed ASL techniques the standard kinetic model and tissue properties of influence to quantitative measurements of perfusion are reported. For the applications demonstrated in this paper a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion preparation approach followed by true fast imaging with steady precession (true FISP) data recording was developed and implemented on whole-body scanners operating at 0.2, 1.5 and 3 T for quantitative perfusion measurement in various types of tissue. ASL imaging provides a non-invasive tool for assessment of tissue perfusion rates in vivo. Images recorded from kidney, lung, brain, salivary gland and thyroid gland provide a spatial resolution of a few millimetres and sufficient signal to noise ratio in perfusion maps after 2-5 min of examination time. Newly developed ASL techniques provide especially high image quality and quantitative perfusion maps in tissues with relatively high perfusion rates (as also present in many tumours). Averaging of acquisitions and image subtraction procedures are mandatory, leading to the necessity of synchronization of data recording to breathing in abdominal and thoracic organs. (orig.)

  6. Perfusion device for liver preservation ex vivo before transplantation: first experimental study

    Directory of Open Access Journals (Sweden)

    O. N. Reznik

    2017-01-01

    Full Text Available Introduction. Successful liver transplantation including from donors with a sudden irreversible cardiac arrest requires the use of modern hardware and technical support to maintain, select and sustain organ viability for the period from harvesting to transplantation to the recipient.Materials and methods. Hardware-software system (HSS developed by the Russian State Scientific Center for Robotics and Technical Cybernetics (RTC was used for testing of normothermic perfusion of donor’s liver ex vivo. The experiment was conducted on the isolated pig liver (Duroc breed in accordance with the ethical principles.Result. During perfusion spontaneous recovery of bile outflow through the cannula installed in the common bile duct (volume of bile released – 240 ml was observed, and the color and uniformity of the perfused liver did not differ from the normal parameters. Biochemical indicators were stabilized at the physiological values after 40 minutes of perfusion procedure.Conclusion. Isolated liver transplant was completely restored after 30 minutes of warm ischemia and was functioning well due to ex vivo perfusion procedure on the new perfusion device. The first case of the new device usage for normothermic liver ex vivo demonstrated hopeful results to be further investigated.

  7. Effect of myocardial perfusion and metabolic interventions on cardiac kinetics of phenylpentadecanoic acid (IPPA) I 123

    Energy Technology Data Exchange (ETDEWEB)

    Reske, S.N.; Schoen, S.; Schmitt, W.; Knopp, R.; Winkler, C.; Machulla, H.J.

    1986-08-01

    The effect of regional myocardial perfusion and flow-independent adrenergic stimulation, as well as lactate-mediated inhibition of cardiac lipolysis, on cardiac IPPA uptake and metabolism was examined in canine hearts (flow studies) and in the isolated perfused Langendorff rat heart (metabolic interventions). In both normal and ischaemic myocardium, local perfusion is a major determinant of cardiac IPPA uptake. In pacing-induced hyperaemia, the strict flow-dependence of cardiac IPPA uptake is not preserved. Adrenergic stimulation raises the rate of oxidation of both palmitic acid /sup 14/C and IPPA. This change is reflected by increased metabolite production released into the perfusate and radioactivity clearance recorded externally. Lactate in high concentrations exerts the opposite effect on cardiac free fatty acid oxidation. IPPA is stored in this condition preferentially in tissue phospholipids and triglycerides.

  8. Effect of myocardial perfusion and metabolic interventions on cardiac kinetics of phenylpentadecanoic acid (IPPA) I 123

    International Nuclear Information System (INIS)

    Reske, S.N.; Schoen, S.; Schmitt, W.; Knopp, R.; Winkler, C.; Machulla, H.J.

    1986-01-01

    The effect of regional myocardial perfusion and flow-independent adrenergic stimulation, as well as lactate-mediated inhibition of cardiac lipolysis, on cardiac IPPA uptake and metabolism was examined in canine hearts (flow studies) and in the isolated perfused Langendorff rat heart (metabolic interventions). In both normal and ischaemic myocardium, local perfusion is a major determinant of cardiac IPPA uptake. In pacing-induced hyperaemia, the strict flow-dependence of cardiac IPPA uptake is not preserved. Adrenergic stimulation raises the rate of oxidation of both palmitic acid 14 C and IPPA. This change is reflected by increased metabolite production released into the perfusate and radioactivity clearance recorded externally. Lactate in high concentrations exerts the opposite effect on cardiac free fatty acid oxidation. IPPA is stored in this condition preferentially in tissue phospholipids and triglycerides. (orig.)

  9. Automatic lung segmentation in the presence of alveolar collapse

    Directory of Open Access Journals (Sweden)

    Noshadi Areg

    2017-09-01

    Full Text Available Lung ventilation and perfusion analyses using chest imaging methods require a correct segmentation of the lung to offer anatomical landmarks for the physiological data. An automatic segmentation approach simplifies and accelerates the analysis. However, the segmentation of the lungs has shown to be difficult if collapsed areas are present that tend to share similar gray values with surrounding non-pulmonary tissue. Our goal was to develop an automatic segmentation algorithm that is able to approximate dorsal lung boundaries even if alveolar collapse is present in the dependent lung areas adjacent to the pleura. Computed tomography data acquired in five supine pigs with injured lungs were used for this purpose. First, healthy lung tissue was segmented using a standard 3D region growing algorithm. Further, the bones in the chest wall surrounding the lungs were segmented to find the contact points of ribs and pleura. Artificial boundaries of the dorsal lung were set by spline interpolation through these contact points. Segmentation masks of the entire lung including the collapsed regions were created by combining the splines with the segmentation masks of the healthy lung tissue through multiple morphological operations. The automatically segmented images were then evaluated by comparing them to manual segmentations and determining the Dice similarity coefficients (DSC as a similarity measure. The developed method was able to accurately segment the lungs including the collapsed regions (DSCs over 0.96.

  10. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

    Immink, R V; Pott, F C; Secher, N H

    2014-01-01

    dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2...... the contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced...... cardiac output brain perfusion becomes jeopardized. Whether, in patients with cardiovascular disease and/or defect, cerebral blood flow cerebral control HV-induced hypocapnia elicits cerebral hypoperfusion, leading to TLOC, remains to be established....

  11. Myocardial perfusion modeling using MRI

    DEFF Research Database (Denmark)

    Larsson, H B; Fritz-Hansen, T; Rostrup, Egill

    1996-01-01

    In the present study, it is shown that it is possible to quantify myocardial perfusion using magnetic resonance imaging in combination with gadolinium diethylenetriaminopentaacetic acid (Gd-DTPA). Previously, a simple model and method for measuring myocardial perfusion using an inversion recovery...... turbo-FLASH (fast low-angle shot) sequence and Gd-DTPA has been presented. Here, an extension of the model is presented taking into account fast and slow water exchange between the compartments, enabling the calculation of the unidirectional influx constant (Ki) for Gd-DTPA, the distribution volume...... of Gd-DTPA (lambda), the vascular blood volume (Vb), and the time delay through the coronary arteries (delta T). The model was evaluated by computer simulation and used on experimental results from seven healthy subjects. The results in the healthy volunteers for a region of interest placed...

  12. Lung perfusion characteristics in pulmonary arterial hypertension (PAH) and peripheral forms of chronic thromboembolic pulmonary hypertension (pCTEPH): Dual-energy CT experience in 31 patients

    Energy Technology Data Exchange (ETDEWEB)

    Giordano, Jessica; Khung, Suonita; Remy, Jacques; Remy-Jardin, Martine [Hospital Calmette (EA 2694), Department of Thoracic Imaging, Lille (France); Duhamel, Alain [University Lille, CHU Lille, Department of Biostatistics, Lille (France); Hossein-Foucher, Claude; Bellevre, Dimitri [University Lille, CHU Lille, Department of Nuclear Medicine, Hospital Salengro, Lille (France); Lamblin, Nicolas [University Lille, CHU Lille, Department of Cardiology, Cardiology Hospital, Lille (France)

    2017-04-15

    To compare lung perfusion in PAH and pCTEPH on dual-energy CT (DECT) examinations. Thirty-one patients with PAH (group 1; n = 19) and pCTEPH (group 2; n = 12) underwent a dual-energy chest CTA with reconstruction of diagnostic and perfusion images. Perfusion alterations were analysed at a segmental level. V/Q scintigraphy was available in 22 patients (group 1: 13/19; group 2: 9/12). CT perfusion was abnormal in 52.6 % of group 1 patients and in 100 % of group 2 patients (p = 0.0051). The patterns of perfusion alteration significantly differed between the two groups (p < 0.0001): (1) in group 1, 96.6 % of segments with abnormal perfusion showed patchy defects; (2) in group 2, the most frequent abnormalities consisted of patchy (58.5 %) and PE-type (37.5 %) defects. Paired comparison of CT perfusion and scintigraphy showed concordant findings in 76.9 % of group 1 (10/13) and 100 % of group 2 (9/9) patients, with a predominant or an exclusive patchy pattern in group 1 and a mixed pattern of abnormalities in group 2. Lung perfusion alterations at DECT are less frequent and more homogeneous in PAH than in pCTEPH, with a high level of concordant findings with V/Q scintigraphy. (orig.)

  13. Dosimetry in myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C. [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2011-07-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  14. Dosimetry in myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C.

    2011-01-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  15. SPECT Analysis of Cardiac Perfusion Changes After Whole-Breast/Chest Wall Radiation Therapy With or Without Active Breathing Coordinator: Results of a Randomized Phase 3 Trial

    Energy Technology Data Exchange (ETDEWEB)

    Zellars, Richard, E-mail: zellari@jhmi.edu [Johns Hopkins Medical Institution, Baltimore, Maryland (United States); Bravo, Paco E. [University of Washington Medical Center, Seattle, Washington (United States); Tryggestad, Erik [Mayo Clinic, Rochester, Minnesota (United States); Hopfer, Kari [Hahnemann University, Philadelphia, Pennsylvania (United States); Myers, Lee; Tahari, Abdel; Asrari, Fariba; Ziessman, Harvey [Johns Hopkins Medical Institution, Baltimore, Maryland (United States); Garrett-Mayer, Elizabeth [Medical University of South Carolina, Charleston, South Carolina (United States)

    2014-03-15

    Purpose: Cardiac muscle perfusion, as determined by single-photon emission computed tomography (SPECT), decreases after breast and/or chest wall (BCW) irradiation. The active breathing coordinator (ABC) enables radiation delivery when the BCW is farther from the heart, thereby decreasing cardiac exposure. We hypothesized that ABC would prevent radiation-induced cardiac toxicity and conducted a randomized controlled trial evaluating myocardial perfusion changes after radiation for left-sided breast cancer with or without ABC. Methods and Materials: Stages I to III left breast cancer patients requiring adjuvant radiation therapy (XRT) were randomized to ABC or No-ABC. Myocardial perfusion was evaluated by SPECT scans (before and 6 months after BCW radiation) using 2 methods: (1) fully automated quantitative polar mapping; and (2) semiquantitative visual assessment. The left ventricle was divided into 20 segments for the polar map and 17 segments for the visual method. Segments were grouped by anatomical rings (apical, mid, basal) or by coronary artery distribution. For the visual method, 2 nuclear medicine physicians, blinded to treatment groups, scored each segment's perfusion. Scores were analyzed with nonparametric tests and linear regression. Results: Between 2006 and 2010, 57 patients were enrolled and 43 were available for analysis. The cohorts were well matched. The apical and left anterior descending coronary artery segments had significant decreases in perfusion on SPECT scans in both ABC and No-ABC cohorts. In unadjusted and adjusted analyses, controlling for pretreatment perfusion score, age, and chemotherapy, ABC was not significantly associated with prevention of perfusion deficits. Conclusions: In this randomized controlled trial, ABC does not appear to prevent radiation-induced cardiac perfusion deficits.

  16. SPECT Analysis of Cardiac Perfusion Changes After Whole-Breast/Chest Wall Radiation Therapy With or Without Active Breathing Coordinator: Results of a Randomized Phase 3 Trial

    International Nuclear Information System (INIS)

    Zellars, Richard; Bravo, Paco E.; Tryggestad, Erik; Hopfer, Kari; Myers, Lee; Tahari, Abdel; Asrari, Fariba; Ziessman, Harvey; Garrett-Mayer, Elizabeth

    2014-01-01

    Purpose: Cardiac muscle perfusion, as determined by single-photon emission computed tomography (SPECT), decreases after breast and/or chest wall (BCW) irradiation. The active breathing coordinator (ABC) enables radiation delivery when the BCW is farther from the heart, thereby decreasing cardiac exposure. We hypothesized that ABC would prevent radiation-induced cardiac toxicity and conducted a randomized controlled trial evaluating myocardial perfusion changes after radiation for left-sided breast cancer with or without ABC. Methods and Materials: Stages I to III left breast cancer patients requiring adjuvant radiation therapy (XRT) were randomized to ABC or No-ABC. Myocardial perfusion was evaluated by SPECT scans (before and 6 months after BCW radiation) using 2 methods: (1) fully automated quantitative polar mapping; and (2) semiquantitative visual assessment. The left ventricle was divided into 20 segments for the polar map and 17 segments for the visual method. Segments were grouped by anatomical rings (apical, mid, basal) or by coronary artery distribution. For the visual method, 2 nuclear medicine physicians, blinded to treatment groups, scored each segment's perfusion. Scores were analyzed with nonparametric tests and linear regression. Results: Between 2006 and 2010, 57 patients were enrolled and 43 were available for analysis. The cohorts were well matched. The apical and left anterior descending coronary artery segments had significant decreases in perfusion on SPECT scans in both ABC and No-ABC cohorts. In unadjusted and adjusted analyses, controlling for pretreatment perfusion score, age, and chemotherapy, ABC was not significantly associated with prevention of perfusion deficits. Conclusions: In this randomized controlled trial, ABC does not appear to prevent radiation-induced cardiac perfusion deficits

  17. Preserved regulation of renal perfusion pressure by small and intermediate conductance K-Ca channels in hypertensive mice with or without renal failure

    DEFF Research Database (Denmark)

    Waeckel, L.; Bertin, F.; Clavreul, N.

    2015-01-01

    -transgenic female mice expressing human angiotensinogen and renin (AR) genes received either control or a high-salt diet associated to a nitric oxide (NO) synthase inhibitor treatment (BLSL and ARSL). Changes in renal perfusion pressure (RPP) were measured in isolated perfused kidneys. BLSL and AR were moderately...

  18. Perfusion abnormalities in congenital and neoplastic pulmonary disease: comparison of MR perfusion and multislice CT imaging

    International Nuclear Information System (INIS)

    Boll, Daniel T.; Lewin, Jonathan S.; Young, Philip; Gilkeson, Robert C.; Siwik, Ernest S.

    2005-01-01

    The aim of this work was to assess magnetic resonance (MR) perfusion patterns of chronic, nonembolic pulmonary diseases of congenital and neoplastic origin and to compare the findings with results obtained with pulmonary, contrast-enhanced multislice computed tomography (CT) imaging to prove that congenital and neoplastic pulmonary conditions require MR imaging over the pulmonary perfusion cycle to successfully and directly detect changes in lung perfusion patterns. Twenty-five patients underwent concurrent CT and MR evaluation of chronic pulmonary diseases of congenital (n=15) or neoplastic (n=10) origin. Analysis of MR perfusion and contrast-enhanced CT datasets was realized by defining pulmonary and vascular regions of interest in corresponding positions. MR perfusion calculated time-to-peak enhancement, maximal enhancement and the area under the perfusion curve. CT datasets provided pulmonary signal-to-noise ratio measurements. Vessel centerlines of bronchial arteries were determined. Underlying perfusion type, such as pulmonary arterial or systemic arterial supply, as well as regions with significant variations in perfusion were determined statistically. Analysis of the pulmonary perfusion pattern detected pulmonary arterial supply in 19 patients; six patients showed systemic arterial supply. In pulmonary arterial perfusion, MR and multislice CT imaging consistently detected the perfusion type and regions with altered perfusion patterns. In bronchial arterial supply, MR perfusion and CT imaging showed significant perfusion differences. Patients with bronchial arterial supply had bronchial arteries ranging from 2.0 to 3.6 mm compared with submillimeter diameters in pulmonary arterial perfusion. Dynamic MR imaging of congenital and neoplastic pulmonary conditions allowed characterization of the pulmonary perfusion type. CT imaging suggested the presence of systemic arterial perfusion by visualizing hypertrophied bronchial arteries. (orig.)

  19. Extraction of Capillary Non-perfusion from Fundus Fluorescein Angiogram

    Science.gov (United States)

    Sivaswamy, Jayanthi; Agarwal, Amit; Chawla, Mayank; Rani, Alka; Das, Taraprasad

    Capillary Non-Perfusion (CNP) is a condition in diabetic retinopathy where blood ceases to flow to certain parts of the retina, potentially leading to blindness. This paper presents a solution for automatically detecting and segmenting CNP regions from fundus fluorescein angiograms (FFAs). CNPs are modelled as valleys, and a novel technique based on extrema pyramid is presented for trough-based valley detection. The obtained valley points are used to segment the desired CNP regions by employing a variance-based region growing scheme. The proposed algorithm has been tested on 40 images and validated against expert-marked ground truth. In this paper, we present results of testing and validation of our algorithm against ground truth and compare the segmentation performance against two others methods.The performance of the proposed algorithm is presented as a receiver operating characteristic (ROC) curve. The area under this curve is 0.842 and the distance of ROC from the ideal point (0,1) is 0.31. The proposed method for CNP segmentation was found to outperform the watershed [1] and heat-flow [2] based methods.

  20. Assmentment of myocardial perfusion by magnetic resonance imaging: on the way to clinical application

    International Nuclear Information System (INIS)

    Fischer, S.E.; Lorenz, C.H.

    1997-01-01

    Magnetic resonance imaging detects the flow of contrast - enhanced blood and even allows the quantitative assessment of myocardial perfusion. The clinical application of this method is being held back by the difficulties in image evaluation and the limitation of standard techniques to the acquisition of a single slice per heart beat cycle. Recent developments in scanner hardware as well as in image acquisition techniques open up the possibility of assessing myocardial perfusion over the entire heart with a spatial resolution in the range of 2 mm. As an example of such a new scanning strategy, a segmented gradient-echo recalled echo planar imaging sequence with preceding saturation is discussed and results in a patient with an infarction are presented. The clinical use of perfusion assessment covering the entire heart for the diagnosis of coronary artery disease is enhanced by the flexibility of magnetic resonance imaging for the assessment of functional cardiac parameters. (orig.) [de

  1. Prognostic value of gated 201Tl myocardial perfusion SPECT imaging in patients with coronary artery disease

    International Nuclear Information System (INIS)

    Li Zicheng; Chen Xiaoming; Xu Hao

    2006-01-01

    Objective: To study the prognostic value of gated 201 Tl myocardial perfusion SPECT imaging in patients with coronary artery disease and assessment of therapy strategy for the individual patient. Methods: Eighty-four patients underwent rest and exercise stress 201 Tl gated myocardial perfusion SPECT imaging and were followed up for (32.92 ± 16.77) months. Images were studied using 17 segments and 1 to 4 scoring. Global summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS=SSS-SRS) were also calculated. Post-stress and rest ejection fraction (EF) were automatically measured. Results: Nine cardiac events occurred (3.90% per year). SSS, SDS, SRS and EF were the independent predictors of cardiac events (P 201 Tl myocardial perfusion SPECT imaging can provide prognostic assessment for the patients with coronary artery disease and guide in selection of therapeutic strategy. Among all of the indices SSS is the best predictors of cardiac events. (authors)

  2. Myocardial perfusion and left ventricular function early after successful PTCA in 1-vessel coronary artery diseases

    International Nuclear Information System (INIS)

    Hoffmeister, H.M.; Kaiser, W.; Hanke, H.; Mueller-Schauenburg, W.; Karsch, K.R.; Seipel, L.

    1994-01-01

    Myocardial perfusion ( 201 Tl-ECT) and contractile function ( 99m Tc-ventriculography) were studied during exercise and rest 3 to 6 days after PTCA in 20 patients (11 with stable and 9 with unstable angina pectoris). All patients had single vessel disease and no previous myocardial infarction. During exercise after PTCA the ejection fraction increased for 3 to 5% and no regional wall motion abnormalities, ST-segment depression or perfusion defects occurred (with exception in one patient with very early restenosis). Therefore, perfusion and wall motion were completely normalized at test and during exercise within days after technically successful PTCA even in patients with previously unstable angina pectoris. Pathological stress test results after this time should thus be attributed to other causes e.g. early restenosis, multivessel disease, false positive tests) and are not due to the specific situation early after PTCA. (orig.) [de

  3. CT arteriography via the right inferior phrenic artery developed parasitic perfusion into the liver

    International Nuclear Information System (INIS)

    Inaba, Yoshitaka; Arai, Yasuaki; Sueyoshi, Satoshi; Yamagami, Takuji; Aramaki, Takeshi; Yamaura, Hidekazu; Matsueda, Kiyoshi; Sasaki, Fumio; Takeuchi, Yoshihito.

    1998-01-01

    The distribution of arterial blood flow via the right inferior phrenic artery (rt-IPA) developing parasitic perfusion into the liver was evaluated by CT arteriography (CTA) in 50 cases with hepatic tumors. In all cases, CTA via rt-IPA showed hyperperfusion area including hepatic tumors in the posterior segment and the caudate lobe of the liver, and adding the left hepatic lobe in cases with hepatic arterial occlusion. In 82% of 33 cases obtained both CTA via rt-IPA and CTA via hepatic artery, the hyperperfusion area on CTA via rt-IPA exactly corresponded to perfusion defect area on CTA via hepatic artery. CTA was much useful for understanding hemodynamics in cases with parasitic perfusion into the liver and it could make transcatheter arterial therapy more effective. (author)

  4. Metabolism of perfused pig intercostal muscles evaluated by 31P-magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Pedersen, Brian Lindegaard; Arendrup, Henrik; Secher, Niels H

    2006-01-01

    This study presents a perfused preparation for evaluation of metabolism in pig intercostal muscle in vitro. Preserved vessels and nerves to an intercostal segment including two adjacent ribs allowed for tissue perfusion and electrical stimulation with measurement of contraction force, oxygen......, as demonstrated in one preliminary experiment. The results demonstrate a stable and functional in vitro preparation of intact perfused intercostal muscles in the pig........ Tonic stimulation of the nerve caused anaerobic energy consumption as PCr and pH decreased, and both variables recovered after the contraction with half-time values of approximately 7 min. Force increased to 0.040 N g(-1) (range, 0.031-0.103 N g(-1)) and it gradually decreased by about 70% during...

  5. CT arteriography via the right inferior phrenic artery developed parasitic perfusion into the liver

    Energy Technology Data Exchange (ETDEWEB)

    Inaba, Yoshitaka; Arai, Yasuaki; Sueyoshi, Satoshi; Yamagami, Takuji; Aramaki, Takeshi; Yamaura, Hidekazu; Matsueda, Kiyoshi; Sasaki, Fumio [Aichi Cancer Center, Nagoya (Japan); Takeuchi, Yoshihito

    1998-02-01

    The distribution of arterial blood flow via the right inferior phrenic artery (rt-IPA) developing parasitic perfusion into the liver was evaluated by CT arteriography (CTA) in 50 cases with hepatic tumors. In all cases, CTA via rt-IPA showed hyperperfusion area including hepatic tumors in the posterior segment and the caudate lobe of the liver, and adding the left hepatic lobe in cases with hepatic arterial occlusion. In 82% of 33 cases obtained both CTA via rt-IPA and CTA via hepatic artery, the hyperperfusion area on CTA via rt-IPA exactly corresponded to perfusion defect area on CTA via hepatic artery. CTA was much useful for understanding hemodynamics in cases with parasitic perfusion into the liver and it could make transcatheter arterial therapy more effective. (author)

  6. Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD

    DEFF Research Database (Denmark)

    Buggeskov, Katrine B; Sundskard, Martin M; Jonassen, Thomas

    2016-01-01

    INTRODUCTION: Absence of pulmonary perfusion during cardiopulmonary bypass (CPB) may be associated with reduced postoperative oxygenation. Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease (COPD) undergoing cardiac surgery. METHODS: 90...... perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing cardiac surgery. Pulmonary artery perfusion with hypothermic HTK solution does not seem to improve postoperative oxygenation. TRIAL REGISTRATION NUMBER...

  7. 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

  8. Percutaneous transluminal angioplasty combining intraarterial drug perfusion for the treatment of chronic lower limb ischemia

    International Nuclear Information System (INIS)

    Liu Yuan; He Chunshui; Liao Huaqiang; Zeng Wei; Zhang Hongwei; Liu Yang; Mu Yan; Liao Huaqiang; Guan Yongsong

    2008-01-01

    Objective: To evaluate the clinical effects of balloon angioplasty in combination with intraarterial perfusion of vasoactive drugs in the treatment of chronic lower limb ischemia. Methods: A total of 21 patients were treated with percutaneous transfemoral or transaxillary approach of balloon dilatation of the occlusive arterial segments, and then followed by perfusion of urokinase, Lipo prostaglandin E 1 and ginkgo leaf injection, respectively, into the responsible arteries via the catheter. Postoperatively, some of the patients with tibioperoneal arteries occlusion were perfused with the same drugs into their diseased arterial segments, one time per day altogether 5-7 times, through the ipsilateral femoral arterial sheath reserved temporarily, and then followed by observation for improvement of ischemia, superficial ulceration and gangrenous change. Results: Of the 21 patients, 20 were successfully treated with percutaneous transluminal balloon dilation and arterial perfusion with a technical successful rate of 95.2% (20/21). Five of the total 20 were additionally treated with the same drugs perfusion 5-7 days through the retained sheath, showing well patency. No serious complications occurred and ischemic symptoms of limbs improved, such as rest pain, claudication and dermo temperature. During 2-7 months follow-up, healing of skin ulcer occurred in 4 patients and breakoff of necrotic digits in 2 with the surface wound healed. Necrotic toes in all patients were dehydrated with stopping of necrosis and without any amputation. Conclusions: Percutaneous transluminal angioplasty combining intraarterial drug perfusion is safe and effective for promoting blood circulation with healing of ulceration and ceasing the development of lesions; with furthermore of maintaining the arterial patency through the retained vascular sheath for sustaining the drug plerfusion. (authors)

  9. Changes in myocardial perfusion due to physical exercise in patients with stable coronary artery disease

    International Nuclear Information System (INIS)

    Kendziorra, Kai; Foerster, Marcus; Sabri, Osama; Kluge, Regine; Walther, Claudia; Moebius-Winkler, Sven; Conradi, Katrin; Schuler, Gerhard; Hambrecht, Rainer

    2005-01-01

    Percutaneous transluminal coronary angioplasty (PTCA) is one of the main therapy options for patients with coronary artery disease (CAD), resulting in an improvement in myocardial perfusion and exercise capacity. Nevertheless, studies have also demonstrated a positive effect of regular exercise training on myocardial perfusion and maximum exercise capacity. The aim of this study was to evaluate changes in myocardial stress perfusion after 1 year of exercise training in comparison with the effects of PTCA in patients with CAD. In 66 male patients with angiographically confirmed significant coronary artery stenosis in one target vessel, myocardial perfusion scintigraphy was performed at baseline and 12 months after randomisation into either a physical exercise group or a PTCA group. Circumferential count rate profiles in 16 wall segments were classified according to their relative count rate and localisation within or outside the area supplied by the stenosed vessel. Ischaemic segments showed a significant improvement in myocardial count rate within the target area after 12 months in both the PTCA and the training group (PTCA group: from 76.8±4.9% to 86.6±10.9%, p=0.03; training group: from 74.0±7.3% to 83.7±10.8%, p<0.01). Outside the target area only the training group showed a significant improvement (from 77.7±4.4% to 91.7±4.8%, p<0.01). Our data indicate a significant improvement in stress myocardial perfusion in the training group after 12 months. The ischaemia is reduced not only in the target region of the leading stenosis but also in other ischaemic myocardial areas. In contrast, after PTCA stress perfusion improves only in the initially ischaemic parts of the target area. (orig.)

  10. Effects of perfusion pressure and insulin on (3H) cytochalasin B (CB) binding to control and diabetic rat hearts

    International Nuclear Information System (INIS)

    Pleta, M.; Chan, T.

    1987-01-01

    Using ( 3 H) CB, they attempted to quantitate the changes in the amount of glucose transporters in the plasma membrane (PM) and intracellular membranes (HSP) prepared from rat hearts perfused with insulin, under low and high pressure. Membranes isolated from non-perfused hearts showed a PM/HSP ratio of (0.593). Hearts perfused with low pressure showed a lower ratio of (0.474). Perfusion with insulin increased the ratio to (1.8), almost a 3-4 fold increase from low perfusion pressure. These data correlate with insulin effects in glucose transport and CB binding in the fat cells. High pressure perfusion increased the PM/HSP ratio by 1-2 fold. ( 3 H) 2-DG transport indicates a comparable increase in glucose uptake with high pressure, but with insulin only a 1.5 fold increase was observed. Initial data obtained from streptozotocin (STZ) injected diabetic rats indicate low CB binding in the PM fraction. Only insulin, but not high perfusion pressure increased PM/HSP ratio in the STZ-diabetic hearts. Their data imply that while both caused apparent translocation of glucose transporters, influences on cardiac glucose metabolism by work load are different. Furthermore, STZ induced diabetes affected only the high perfusion pressure-induced and not the insulin-stimulated change in CB binding

  11. Simultaneous assessment of myocardial perfusion and function during mental stress in patients with chronic coronary artery disease.

    Science.gov (United States)

    Arrighi, James A; Burg, Matthew; Cohen, Ira S; Soufer, Robert

    2003-01-01

    Mental stress (MS) is an important provocateur of myocardial ischemia in many patients with chronic coronary artery disease. The majority of laboratory assessments of ischemia in response to MS have included measurements of either myocardial perfusion or function alone. We performed this study to determine the relationship between alterations in perfusion and ventricular function during MS. Methods and results Twenty-eight patients with reversible perfusion defects on exercise or pharmacologic stress myocardial perfusion imaging (MPI) underwent simultaneous technetium 99m sestamibi single photon emission computed tomography (SPECT) MPI and transthoracic echocardiography at rest and during MS according to a mental arithmetic protocol. In all cases the MS study was performed within 4 weeks of the initial exercise or pharmacologic MPI that demonstrated ischemia. SPECT studies were analyzed visually with the use of a 13-segment model and quantitatively by semiautomated circumferential profile analysis. Echocardiograms were graded on a segmental model for regional wall motion on a 4-point scale. Of 28 patients, 18 (64%) had perfusion defects and/or left ventricular dysfunction develop during MS: 9 (32%) had myocardial perfusion defects develop, 6 (21%) had regional or global left ventricular dysfunction develop, and 3 (11%) had both perfusion defects and left ventricular dysfunction develop. The overall concordance between perfusion and function criteria for ischemia during MS was only 46%. Among 9 patients with MS-induced left ventricular dysfunction, 5 had new regional wall motion abnormalities and 4 had a global decrement in function. In patients with MS-induced ischemia by SPECT, the number of reversible perfusion defects was similar during both MS and exercise/pharmacologic stress (2.8 +/- 2.0 vs 3.5 +/- 1.8, P =.41). Hemodynamic changes during MS were similar whether patients were divided on the basis of perfusion defects or left ventricular dysfunction during MS

  12. Intra-peritoneal administration of interleukin-1 beta induces impaired insulin release from the perfused rat pancreas

    DEFF Research Database (Denmark)

    Wogensen, L; Helqvist, S; Pociot, F

    1990-01-01

    Previous studies have demonstrated a stimulatory effect of interleukin-1 beta (IL-1 beta) on insulin and glucagon release from the perfused rat pancreas, accompanied by selective lysis of 20% of beta-cells as assessed by electronmicroscopy. However, we have not observed an inhibitory action of IL-1...... beta on insulin release from the perfused pancreas as shown for isolated islets. To test whether periodical exposure of the endocrine pancreas to circulating IL-1 beta in vivo affects insulin release from the intact perfused pancreas, rats were treated with daily intraperitoneal injections of 4...

  13. Long-term cigarette smoking is associated with increased myocardial perfusion heterogeneity assessed by positron emission tomography

    International Nuclear Information System (INIS)

    Meeder, J.G.; Blanksma, P.K.; Wall, E.E. van der; Anthonio, R.L.; Willemsen, A.T.M.; Pruim, J.; Vaalburg, W.; Lie, K.I.

    1996-01-01

    The pathophysiology of smoking-related coronary events in patients with normal coronary arteries is incompletely understood. This study was conducted to explore, in subjects without symptoms of cardiovascular disease, the long-term effects of smoking on regional coronary artery vasoactivity, especially during sympathetic stimulation. In ten smoking and ten non-smoking sex- and age-matched healthy volunteers, segmental myocardial perfusion was studied using dynamic parametric nitrogen-13 ammonia positron emission tomography at rest and during sympathetic stimulation evoked by the cold pressor stimulation. Smokers demonstrated a higher myocardial perfusion at rest (116±17 ml/min/100 g vs 96±20 ml/min/100 g, P <0.01) and an impaired myocardial perfusion increase during cold pressor stimulation (1.02±0.15 vs 1.18±0.17, P <0.05). The heterogeneity of perfusion, expressed as coefficient of variation, was significantly different between the smoking and the non-smoking group. The coefficient of variation of segmental myocardial perfusion was higher in smokers at rest (17.5%±4.2% vs 13.5%±1.9%, P <0.05) and during cold pressor stimulation (17.0%±3.2% vs 13.9%±1.8%, P <0.05). We conclude that the long-term effects of smoking in healthy volunteers are associated with (1) increased myocardial perfusion at rest, (2) impaired myocardial perfusion response to cold pressor stimulation, and (3) increased myocardial perfusion heterogeneity both at rest and during cold pressor stimulation. These results may suggest that in healthy subjects the long-term effect of smoking is related to abnormal coronary artery vasoactivity, presumably induced by an interplay of regional endothelial dysfunction and autonomic dysregulation. (orig.). With 1 fig., 1 tab

  14. Long-term cigarette smoking is associated with increased myocardial perfusion heterogeneity assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Meeder, J.G. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Blanksma, P.K. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Wall, E.E. van der [Department of Cardiology, University Hospital, Leiden (Netherlands); Anthonio, R.L. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Willemsen, A.T.M. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Pruim, J. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Vaalburg, W. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Lie, K.I. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands)

    1996-11-01

    The pathophysiology of smoking-related coronary events in patients with normal coronary arteries is incompletely understood. This study was conducted to explore, in subjects without symptoms of cardiovascular disease, the long-term effects of smoking on regional coronary artery vasoactivity, especially during sympathetic stimulation. In ten smoking and ten non-smoking sex- and age-matched healthy volunteers, segmental myocardial perfusion was studied using dynamic parametric nitrogen-13 ammonia positron emission tomography at rest and during sympathetic stimulation evoked by the cold pressor stimulation. Smokers demonstrated a higher myocardial perfusion at rest (116{+-}17 ml/min/100 g vs 96{+-}20 ml/min/100 g, P <0.01) and an impaired myocardial perfusion increase during cold pressor stimulation (1.02{+-}0.15 vs 1.18{+-}0.17, P <0.05). The heterogeneity of perfusion, expressed as coefficient of variation, was significantly different between the smoking and the non-smoking group. The coefficient of variation of segmental myocardial perfusion was higher in smokers at rest (17.5%{+-}4.2% vs 13.5%{+-}1.9%, P <0.05) and during cold pressor stimulation (17.0%{+-}3.2% vs 13.9%{+-}1.8%, P <0.05). We conclude that the long-term effects of smoking in healthy volunteers are associated with (1) increased myocardial perfusion at rest, (2) impaired myocardial perfusion response to cold pressor stimulation, and (3) increased myocardial perfusion heterogeneity both at rest and during cold pressor stimulation. These results may suggest that in healthy subjects the long-term effect of smoking is related to abnormal coronary artery vasoactivity, presumably induced by an interplay of regional endothelial dysfunction and autonomic dysregulation. (orig.). With 1 fig., 1 tab.

  15. Blood perfusion and pH monitoring in organs by laser-induced fluorescence spectroscopy

    Science.gov (United States)

    Vari, Sandor G.; Papazoglou, Theodore G.; Pergadia, Vani R.; Stavridi, Marigo; Snyder, Wendy J.; Papaioannou, Thanassis; Duffy, J. T.; Weiss, Andrew B.; Thomas, Reem; Grundfest, Warren S.

    1994-01-01

    Sensitivity of laser-induced fluorescence spectroscopy (LIFS) in detecting a change in tissue pH, and blood perfusion was determined. Rabbits were anesthetized, paralyzed, and mechanically ventilated. The arterial and venous blood supplies of the kidney were isolated and ligated to alter the perfusion. The femoral artery was cannulated to extract samples for blood gas analysis. A 308-nm XeCl was used as an excitation source. A 600 micrometers core diameter fiber was used for fluorescence acquisition, and the spectra analyzed by an optical multichannel analyzer (EG & G, OMA III). the corresponding intensity ratio R equals INADH / ICOLL was used as an index for respiratory acidosis. Blood perfusion was assessed using the following algorithm: (IELAS minus ICOLL) divided by (INADH minus ICOLL). The intensity ratio linearly decreased with the reduction of blood perfusion. When we totally occluded the artery the ratio decreased tenfold when compared to the ratio of a fully perfused kidney. Results of monitoring blood acidosis by laser-induced fluorescence spectroscopy shows a significant trend between pH and intensity ratio. Since all the slopes were negative, there is an obvious significant correlation between the pH and NADH.COLLAGEN RATIO. Blue-light-induced fluorescence measurements and ratio fluorometry is a sensitive method for monitoring blood perfusion and acidity or alkalinity of an organ.

  16. 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.

  17. The effect of dexmedetomidine on cerebral perfusion and oxygenation in healthy piglets with normal and lowered blood pressure anaesthetized with propofol-remifentanil total intravenous anaesthesia

    DEFF Research Database (Denmark)

    Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Rasmussen, Rune

    2017-01-01

    Background During anaesthesia and surgery, in particular neurosurgery, preservation of cerebral perfusion and oxygenation (CPO) is essential for normal postoperative brain function. The isolated effects on CPO of either individual anaesthetic drugs or entire anaesthetic protocols are of importance...

  18. Michaëlis--Menten kinetics of phenazone elimination in the perfused pig liver

    DEFF Research Database (Denmark)

    Andreasen, B; Tonnesen, K; Rabol, A

    1977-01-01

    The purpose of the present study was to define the elimination kinetics of phenazone (NFN) in the isolated perfused pig liver. In five experiments phenazone was administered as constant infusion to obtain steady-state periods over a wide range of concentrations. The elimination of phenazone follo...

  19. 50 Years of renal physiology from one man and the perfused tubule: Maurice B. Burg.

    Science.gov (United States)

    Hamilton, Kirk L; Moore, Antoni B

    2016-08-01

    Technical advancements in research techniques in science are made in slow increments. Even so, large advances from insight and hard work of an individual with a single technique can have astonishing ramifications. Here, we examine the impact of Dr. Maurice B. Burg and the isolated perfused renal tubule technique and celebrate the 50th anniversary of the publication by Dr. Burg and his colleagues of their landmark paper in the American Journal of Physiology in 1966. In this study, we have taken a scientific visualization approach to study the scientific contributions of Dr. Burg and the isolated perfused tubule preparation as determining research impact by the number of research students, postdoctoral fellows, visiting scientists, and national and international collaborators. Additionally, we have examined the research collaborations (first and second generation scientists), established the migrational visualization of the first generation scientists who worked directly with Dr. Burg, quantified the metrics indices, identified and quantified the network of coauthorship of the first generation scientists with their second generation links, and determined the citations analyses of outputs of Dr. Burg and/or his first generation collaborators as coauthors. We also review the major advances in kidney physiology that have been made with the isolated perfused tubule technique. Finally, we are all waiting for the discoveries that the isolated perfused preparation technique will bring during the next 50 years. Copyright © 2016 the American Physiological Society.

  20. Effects of thyroid state on respiration of perfused rat and guinea pig hearts

    International Nuclear Information System (INIS)

    Read, L.C.; Wallace, P.G.; Berry, M.N.

    1987-01-01

    The effects of thyroid state on the respiration of the isolated heart were investigated using retrograde perfused rat and guinea pig hearts. In both species, hypothyroidism caused a marked depression in circulating thyroid hormone concentrations and in the respiration of the isolated, retrograde perfused heart. Hypothyroidism was caused by injecting animals with Na 131 I. The effects on myocardial respiration could be attributed to changes in the contraction frequency and in the oxygen consumption per beat, with little contribution from basal respiration. Treatment of animals with thyroxine elevated plasma thyroid hormones to a similar extent in rats and guinea pigs. In the latter, thyroxine treatment was associated with substantial increases in the contraction frequency and the oxygen consumption per beat of the isolated heart. In contrast, only small changes were apparent in the retrograde perfused rat heart, observations that were confirmed in rat hearts perfused at near physiological work loads. It was concluded that rat hearts isolated from normal animals function at near maximal thyroid state, in contrast to the guinea pig heart, which requires higher circulating concentrations of thyroid hormones to attain maximal responses

  1. 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.

  2. Increased perfusion pressure enhances the expression of endothelin (ETB) and angiotensin II (AT1, AT2) receptors in rat mesenteric artery smooth muscle cells

    DEFF Research Database (Denmark)

    Lindstedt, Isak; Xu, Cang-Bao; Zhang, Yaping

    2009-01-01

    and luminally perfused in a perfusion chamber. After either exposure to no ("organ culture" (0 mmHg)), normal (85/75 mmHg) or high pressure (160/150 mmHg) at constant flow for 1-17 h, the vessel segments were snap frozen and real-time polymerase chain reaction was performed to quantify the ET- and AT-receptor m...

  3. Inhibition of gluconeogenesis in the perfusing liver of irradiated rats

    International Nuclear Information System (INIS)

    Borovikova, G.V.; Dokshina, G.A.; Ermakova, G.N.; Mashkova, N.Yu.

    1981-01-01

    It was shown on the perfusing liver taken from rats on the 1st and 3d days after irradiation in a dose of 18.06x10 -2 C/kg that insulin (400 μunits/ml) and taurine (40 mg%) exerted an inhibiting action on the rate of gluconeogenesi.s and transamination, catalyzed by alanine aminoferase and aspartate aminoferase, in a soluble fraction of the irradiated rat liver. The gluconeogenic capacity and the reactivity of the isolated organ were shown to decrease on the 3d day after irradiation [ru

  4. Diagnostic value of transesophageal atrial pacing myocardial perfusion imaging in coronary artery disease

    International Nuclear Information System (INIS)

    Jia Yongping; Li Zhiling; Li Yunqian

    1994-01-01

    Transesophageal atrial pacing (TAP) SPECT myocardial perfusion imaging (MPI) with 99m Tc-MIBI was performed in 46 patients with coronary artery disease (CAD) and 15 normal subjects. The results were compared with exercise SPECT MPI. The results showed that the sensitivity and specificity of TAP SPECT to evaluate CAD were 86,96% and 93.33%. TAP SPECT MPI had a significant correlation with exercise SPECT MPI to detect ischemic segment of CAD (r = 0.95)

  5. Retrospective respiratory triggering renal perfusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Attenberger, Ulrike I.; Michaely, Henrik J.; Schoenberg, Stefan O. (Dept. of Clinical Radiology and Nuclear Medicine, Univ. Hospital Mannheim, Univ. of Heidelberg, Mannheim (Germany)), e-mail: ulrike.attenberger@medma.uni-heidelberg.de; Sourbron, Steven P. (Div. of Medical Physics, Univ. of Leeds, Leeds (United Kingdom)); Reiser, Maximilian F. (Dept. of Clinical Radiology, Univ. Hospitals Munich, Grosshadern, Ludwig-Maximilians-Univ., Munich (Germany))

    2010-12-15

    Background: Artifacts of respiratory motion are one of the well-known limitations of dynamic contrast-enhanced MRI (DCE-MRI) of the kidney. Purpose: To propose and evaluate a retrospective triggering approach to minimize the effect of respiratory motion in DCE-MRI of the kidney. Material and Methods: Nine consecutive patients underwent renal perfusion measurements. Data were acquired with a 2D saturation-recovery TurboFLASH sequence. In order to test the dependence of the results on size and location of the manually drawn triggering regions of interest (ROIs), three widely differing triggering regions were defined by one observer. Mean value, standard deviation, and variability of the renal function parameters plasma flow (FP), plasma volume (VP), plasma transit time (TP), tubular flow (FT), tubular volume (VT), and tubular transit time (TT) were calculated on a per-patient basis. Results: The results show that triggered data have adequate temporal resolution to measure blood flow. The overall average values of the function parameters were: 152.77 (FP), 15.18 (VP), 6,73 (TP), 18.50 (FT), 35.36 (VT), and 117.67 (TT). The variability (calculated in % SD from the mean value) for three different respiratory triggering regions defined on a per-patient basis was between 0.81% and 9.87% for FP, 1.45% and 8.19% for VP, 0% and 9.63% for TP, 2.15% and 12.23% for TF, 0.8% and 17.28% for VT, and 1.97% and 12.87% for TT. Conclusion: Triggering reduces the oscillations in the signal curves and produces sharper parametric maps. In contrast to numerically challenging approaches like registration and segmentation it can be applied in clinical routine, but a (semi)-automatic approach to select the triggering ROI is desirable to reduce user dependence.

  6. Quality assessment of a placental perfusion protocol

    DEFF Research Database (Denmark)

    Mathiesen, Line; Mose, Tina; Mørck, Thit Juul

    2010-01-01

    mlh(-1) from the fetal reservoir) when adding 2 (n=7) and 20mg (n=9) FITC-dextran/100ml fetal perfusion media. Success rate of the Copenhagen placental perfusions is provided in this study, including considerations and quality control parameters. Three checkpoints suggested to determine success rate...

  7. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Yong; Lee, Ki Hyeong; Yoon, Byung Woo; Lee, Sang Bok; Jeon, Beom S. [Samsung Medical Center, Seoul (Korea, Republic of); Lee, Kyung Han; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1996-03-15

    Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p<0.05). There was no correlation between the severity of the motor abnormality and any of the regional cerebral perfusion indices (p>0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

  8. Computed Tomography (CT) Perfusion in Abdominal Cancer

    DEFF Research Database (Denmark)

    Hansen, Martin Lundsgaard; Norling, Rikke; Lauridsen, Carsten

    2013-01-01

    Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed...

  9. Clinical application of cerebral dynamic perfusion studies

    International Nuclear Information System (INIS)

    DeLand, F.H.

    1975-01-01

    Radionuclide cerebral perfusion studies are assuming a far greater importance in the detection and differential diagnosis of cerebral lesions. Perfusion studies not only contribute to the differential diagnosis of lesions but in certain cases are the preferred methods by which more accurate clinical interpretations can be made. The characteristic blood flow of arterio-venous malformations readily differentiates this lesion from neoplasms. The decreased perfusion or absent perfusion observed in cerebral infarctions is diagnostic without concurrent evidence from static images. Changes in rates and direction of blood flow contribute fundamental information to the status of stenosis and vascular occlusion and, in addition, offer valuable information on the competency and routes of collateral circulation. The degree of cerebral perfusion after cerebral vascular accidents appears to be directly related to patient recovery, particularly muscular function. Cerebral perfusion adds a new parameter in the diagnosis of subdural haematomas and concussion and in the differentiation of obscuring radioactivity from superficial trauma. Although pictorial displays of perfusion blood flow will offer information in most cerebral vascular problems, the addition of computer analysis better defines temporal relationships of regional blood flow, quantitative changes in flow and the detection of the more subtle increases or decreases in cerebral blood flow. The status of radionuclide cerebral perfusion studies has taken on an importance making it the primary modality for the diagnosis of cerebral lesions. (author)

  10. Flow heterogeneity following global no-flow ischemia in isolated rabbit heart

    International Nuclear Information System (INIS)

    Marshall, Robert C.; Powers-Risius, Patricia; Reutter, Bryan W.; Schustz, Amy M.; Kuo, Chaincy; Huesman, Michelle K.; Huesman, Ronald H.

    2002-01-01

    The purpose of this study was to evaluate flow heterogeneity and impaired reflow during reperfusion following 60 min global no-flow ischemia in the isolated rabbit heart. Radiolabeled microspheres were used to measure relative flow in small left ventricular (LV) segments in five ischemia + reperfused hearts and in five non-ischemic controls. Although variable in the post-ischemic hearts, flow heterogeneity was increased relative to pre-ischemia for the whole LV (0.92 plus or minus 0.41 vs. 0.37 plus or minus 0.07, P < 0.05) as well as the subendocardium (Endo) and subepicardium (Epi) considered separately (endo: 1.28 plus or minus 0.74 vs. 0.30 plus or minus 0.09; epi: 0.69 plus or minus 0.22 vs. 0.38 plus or minus 0.08; P < 0.05 for both comparisons) during early reperfusion. There were also segments with abnormally reduced reflow. The number of segments with abnormally reduced reflow increased as flow heterogeneity increased. Abnormally reduced reflow indicates that regional ischemia can persist despite restoration of normal global flow. In addition, the relationship between regional and global flow is altered and venous outflow is derived from regions with continued perfusion and not the whole LV. These observations emphasize the need to quantify regional reflow during reperfusion following sustained no-flow ischemia in the isolated rabbit heart

  11. Flow heterogeneity following global no-flow ischemia in isolated rabbit heart

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Robert C.; Powers-Risius, Patricia; Reutter, Bryan W.; Schustz, Amy M.; Kuo, Chaincy; Huesman, Michelle K.; Huesman, Ronald H.

    2003-02-01

    The purpose of this study was to evaluate flow heterogeneity and impaired reflow during reperfusion following 60 min global no-flow ischemia in the isolated rabbit heart. Radiolabeled microspheres were used to measure relative flow in small left ventricular (LV) segments in five ischemia + reperfused hearts and in five non-ischemic controls. Although variable in the post-ischemic hearts, flow heterogeneity was increased relative to pre-ischemia for the whole LV (0.92 plus or minus 0.41 vs. 0.37 plus or minus 0.07, P < 0.05) as well as the subendocardium (Endo) and subepicardium (Epi) considered separately (endo: 1.28 plus or minus 0.74 vs. 0.30 plus or minus 0.09; epi: 0.69 plus or minus 0.22 vs. 0.38 plus or minus 0.08; P < 0.05 for both comparisons) during early reperfusion. There were also segments with abnormally reduced reflow. The number of segments with abnormally reduced reflow increased as flow heterogeneity increased. Abnormally reduced reflow indicates that regional ischemia can persist despite restoration of normal global flow. In addition, the relationship between regional and global flow is altered and venous outflow is derived from regions with continued perfusion and not the whole LV. These observations emphasize the need to quantify regional reflow during reperfusion following sustained no-flow ischemia in the isolated rabbit heart.

  12. Prevalence and predictors of an abnormal stress myocardial perfusion study in asymptomatic patients with type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Scholte, Arthur J.H.A.; Schuijf, Joanne D.; Wall, Ernst E. van der; Bax, Jeroen J.; Kharagjitsingh, Antje V.; Dibbets-Schneider, Petra; Stokkel, Marcel P.

    2009-01-01

    The purpose of this study was to evaluate the prevalence of an abnormal stress myocardial perfusion study in a cohort of truly asymptomatic patients with type 2 diabetes mellitus using myocardial perfusion imaging by means of single photon emission computed tomography (SPECT). Secondly, we determined which clinical characteristics may predict an abnormal stress myocardial perfusion study in this population. A total of 120 asymptomatic patients (mean age 53±10 years) with type 2 diabetes mellitus and one or more risk factors for coronary artery disease were prospectively recruited from an outpatient diabetes clinic. All patients underwent myocardial perfusion imaging by means of adenosine 99m Tc sestamibi SPECT. Images were evaluated for the presence of perfusion abnormalities as well as other nonperfusion abnormalities that may indicate extensive ischaemia, including left ventricular dysfunction (defined as a left ventricular ejection fraction <45%), transient ischaemic dilatation and adenosine-induced ST segment depression. Multivariable analysis was performed using a backward selection strategy to identify potential predictors for an abnormal stress myocardial perfusion study. Finally, all patients were followed up for 12 months to determine the occurrence of cardiovascular events: (1) cardiac death, (2) nonfatal myocardial infarction, (3) unstable angina requiring hospitalization, (4) revascularization, or (5) stroke. Of the 120 patients, 40 (33%) had an abnormal stress study, including myocardial perfusion abnormalities in 30 patients (25%). In 10 patients (8%), indicators of extensive (possibly balanced ischaemia) were observed in the absence of abnormal perfusion. The multivariable analysis identified current smoking, duration of diabetes and the cholesterol/high-density lipoprotein (HDL) ratio as independent predictors of an abnormal stress study. During a follow-up period of 12 months six patients (5%) had a cardiovascular event. The current study revealed

  13. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......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 over......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

  14. Brain Perfusion Changes in Intracerebral Hemorrhage

    International Nuclear Information System (INIS)

    Mititelu, R.; Mazilu, C.; Ghita, S.; Rimbu, A.; Marinescu, G.; Codorean, I.; Bajenaru, O.

    2006-01-01

    Full text: Purpose: Despite the latest advances in medical treatment and neuro critical care, patients suffering spontaneous intracerebral hemorrhage (SICH) still have a very poor prognosis, with a greater mortality and larger neurological deficits at the survivors than for ischemic stroke. Many authors have shown that there are many mechanisms involved in the pathology of SICH: edema, ischemia, inflammation, apoptosis. All of these factors are affecting brain tissue surrounding hematoma and are responsible of the progressive neurological deterioration; most of these damages are not revealed by anatomical imaging techniques. The aim of our study was to asses the role of brain perfusion SPECT in demonstrating perfusion changes in SICH patients. Method: 17 SICH pts were studied. All pts underwent same day CT and brain SPECT with 99mTcHMPAO, 24h-5d from onset of stroke. Results: 14/17 pts showed a larger perfusion defect than expected after CT. In 2 pts hematoma diameter was comparable on CT and SPECT; 1pt had quasinormal aspect of SPECT study. In pts with larger defects, SPECT revealed a large cold spot with similar size compared with CT, and a surrounding hypo perfused area. 6/17 pts revealed cortical hyper perfusion adjacent to hypo perfused area and corresponding to a normal-appearing brain tissue on CT. In 3 pts we found crossed cerebellar diaskisis.In 2 pts we found cortical hypo perfused area in the contralateral cortex, with normal appearing brain tissue on CT. Conclusions: Brain perfusion SPECT revealed different types of perfusion changes in the brain tissue surrounding hematoma. These areas contain viable brain tissue that may be a target for future ne uroprotective strategies. Further studies are definitely required to demonstrate prognostic significance of these changes, but we can conclude that brain perfusion SPECT can play an important role in SICH, by early demonstrating functional changes responsible of clinical deterioration, thus allowing prompt

  15. TH-CD-206-01: Expectation-Maximization Algorithm-Based Tissue Mixture Quantification for Perfusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Han, H; Xing, L [Stanford University, Palo Alto, CA (United States); Liang, Z [Stony Brook University, Stony Brook, NY (United States); Li, L [City University of New York College of Staten Island, Staten Island, NY (United States)

    2016-06-15

    Purpose: To investigate the feasibility of estimating the tissue mixture perfusions and quantifying cerebral blood flow change in arterial spin labeled (ASL) perfusion MR images. Methods: The proposed perfusion MR image analysis framework consists of 5 steps: (1) Inhomogeneity correction was performed on the T1- and T2-weighted images, which are available for each studied perfusion MR dataset. (2) We used the publicly available FSL toolbox to strip off the non-brain structures from the T1- and T2-weighted MR images. (3) We applied a multi-spectral tissue-mixture segmentation algorithm on both T1- and T2-structural MR images to roughly estimate the fraction of each tissue type - white matter, grey matter and cerebral spinal fluid inside each image voxel. (4) The distributions of the three tissue types or tissue mixture across the structural image array are down-sampled and mapped onto the ASL voxel array via a co-registration operation. (5) The presented 4-dimensional expectation-maximization (4D-EM) algorithm takes the down-sampled three tissue type distributions on perfusion image data to generate the perfusion mean, variance and percentage images for each tissue type of interest. Results: Experimental results on three volunteer datasets demonstrated that the multi-spectral tissue-mixture segmentation algorithm was effective to initialize tissue mixtures from T1- and T2-weighted MR images. Compared with the conventional ASL image processing toolbox, the proposed 4D-EM algorithm not only generated comparable perfusion mean images, but also produced perfusion variance and percentage images, which the ASL toolbox cannot obtain. It is observed that the perfusion contribution percentages may not be the same as the corresponding tissue mixture volume fractions estimated in the structural images. Conclusion: A specific application to brain ASL images showed that the presented perfusion image analysis method is promising for detecting subtle changes in tissue perfusions

  16. TH-CD-206-01: Expectation-Maximization Algorithm-Based Tissue Mixture Quantification for Perfusion MRI

    International Nuclear Information System (INIS)

    Han, H; Xing, L; Liang, Z; Li, L

    2016-01-01

    Purpose: To investigate the feasibility of estimating the tissue mixture perfusions and quantifying cerebral blood flow change in arterial spin labeled (ASL) perfusion MR images. Methods: The proposed perfusion MR image analysis framework consists of 5 steps: (1) Inhomogeneity correction was performed on the T1- and T2-weighted images, which are available for each studied perfusion MR dataset. (2) We used the publicly available FSL toolbox to strip off the non-brain structures from the T1- and T2-weighted MR images. (3) We applied a multi-spectral tissue-mixture segmentation algorithm on both T1- and T2-structural MR images to roughly estimate the fraction of each tissue type - white matter, grey matter and cerebral spinal fluid inside each image voxel. (4) The distributions of the three tissue types or tissue mixture across the structural image array are down-sampled and mapped onto the ASL voxel array via a co-registration operation. (5) The presented 4-dimensional expectation-maximization (4D-EM) algorithm takes the down-sampled three tissue type distributions on perfusion image data to generate the perfusion mean, variance and percentage images for each tissue type of interest. Results: Experimental results on three volunteer datasets demonstrated that the multi-spectral tissue-mixture segmentation algorithm was effective to initialize tissue mixtures from T1- and T2-weighted MR images. Compared with the conventional ASL image processing toolbox, the proposed 4D-EM algorithm not only generated comparable perfusion mean images, but also produced perfusion variance and percentage images, which the ASL toolbox cannot obtain. It is observed that the perfusion contribution percentages may not be the same as the corresponding tissue mixture volume fractions estimated in the structural images. Conclusion: A specific application to brain ASL images showed that the presented perfusion image analysis method is promising for detecting subtle changes in tissue perfusions

  17. Renovascular hypertension due to insufficient collateral flow in segmental artery occulusion

    International Nuclear Information System (INIS)

    Park, Y. H.; Lee, S. Y.; Kim, S. H.; Sohn, H. S.; Chung, S. K.

    2001-01-01

    We report a case in which a 33-year-old woman with renovascular hypertension due to insufficient collateral flow in segmental renal artery occlusion demonstrated abnormality on captopril renal scintigram. Baseline renal scintigram with DTPA showed normal perfusion and excretion in left kidney and captopril renal scintigram with DTPA showed a focal area of decreased perfusion and delayed clearance in lower half of left kidney, suggesting segmental renal artery stenosis. Selective left renal arteriography showed complete obstruction in proximal portion of anterior segmental artery with multiple small collateral vessels from posterior segmental artery and capsular artery and delayed opacification in lower half of left kidney. These findings are suggestive of segmental hypoperfusion due to insufficient collateral blood flow resulting to positive captopril response. Patient's blood pressure have been controlled well with ACE (angiotensin converting enzyme) inhibitor and calcium channel blocker for 2 year. Follow-up baseline renal scintigram with MAG3 showed normal perfusion and excretion in left kidney and captopril renal scintigram with MAG3 showed a focal area of decreased perfusion and delayed clearance in lower lateral portion of left kidney, which was smaller size than that of previous renal scintigram. And captopril renal scintigram with DMSA demonstrated a small area of decreased DMSA uptake on this lesion compared to baseline DMSA scintigram

  18. A comparison of adenosine and arbutamine for myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Anagnostopoulos, C.; Pennell, D.; Francis, J.; Serup-Hansen, K.; Davies, G.; Underwood, R.

    1998-01-01

    We have compared our standard stress protocol (adenosine combined with exercise) with the new stress agent arbutamine, for thallium-201 myocardial perfusion imaging (MPI) in order to assess the comparative value of arbutamine. We studied 23 patients referred for MPI, and each patient had two studies (18 males, median age 66 years, five with previous myocardial infarction). Uptake scores were assigned to each of nine segments, and the extent and severity of defects were measured using a polar plot. Haemodynamic changes were greater with arbutamine (rate-pressure product increase 78% vs 51%, P = 0.003). Symptoms were experienced by 21 patients with arbutamine and 16 with adenosine (P = 0.07). Agreement between the techniques for classification of patients as normal or as having reversible, fixed or mixed defects was good (19 of 23 studies, 83%, κ = 0.76). Agreement for similar classification of segments was also good (82%, κ = 0.71). Segmental agreement for stress scores was good (86%, κ = 0.77). However, mean size of stress defect was larger with adenosine (83±52 pixels vs 65±48 pixels, P<0.05), though severity and reversibility were similar (P = NS). We conclude that arbutamine provides comparable results to those obtained with adenosine and exercise and that the observed differences are not clinically significant. (orig.)

  19. Impact of patient motion on myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Huang Kemin; Feng Yanlin; He Xiaohong; Wen Guanghua; Yu Fengwen; Liu Shusheng; Liu Dejun; Yuan Jianwei; Yang Ming

    2008-01-01

    Objective: It is well known that patient motion may cause artifacts in myocardial SPECT images and affect clinical diagnosis. The aim of the study was to evaluate the effects of motion on quality and semi-quantitative results of myocardial perfusion images. Methods: Six healthy volunteers un- derwent myocardial perfusion SPECT. The raw data in each case was manually shifted 1-6 frames and 1 4 pixels, respectively by using the motion correction software. The shifted raw data were then reconstructed. A semi-quantitative software was used to assess the myocardial perfusion of left ventricle. The quality and semi-quantitative results of the tomographic images reconstructed from the raw data with and without motion were compared and analyzed. SPSS 12.0 was used for data analysis. Results: There was no visible artifact and semi-quantitative difference on the data with 1 frame and (or) 1 pixel shift when compared with the original data without shift. The image artifacts became significantly deteriorated when the number of flame and (or) pixel shift was increased. In general, the image artifact of inferior and posterior wall was related to the upward shift, and that of anterior and infero-posterior wall was related to the downward shift, that of septal, anterior, infero-postefior wall and apex was related to right-ward shift, and the septal and infero-posterior wall was related to the left-ward shift. The differences along the x-axis shift were more prominent than that of the y-axis (t=2.848, P<0.01), and the differences in the downward and rightward shift were more severe than the upward and leftward shift (t=2.941, 6.598; all P<0.01), respectively. Conclusions: Image artifacts became significant when there was motion induced by manual shift of more than one flame and (or) one pixel. Different motion directions were closely related to different segments of left ventricle. (authors)

  20. Calcium-sensitivity of smooth muscle contraction in the isolated ...

    African Journals Online (AJOL)

    sensitivity of smooth muscle contraction were studied in the isolated perfused rat tail artery, employing the activators noradrenaline (NA) (3ìM) sand potassium chloride (KC1) (100mM). Experiments were conduced in Ca2+ - buffered saline.

  1. Ion selectivity of the cation transport system of isolated intact cattle rod outer segments: evidence for a direct communication between the rod plasma membrane and the rod disk membranes.

    Science.gov (United States)

    Schnetkamp, P P

    1980-05-08

    The ion selectivity of cation transport through the plasma membrane of isolated intact cattle rod outer segments (rods) is investigated by means of 45Ca-exchange experiments and light-scattering experiments. These techniques appear to provide complementary information: the 45Ca experiments (45Ca fluxes in rods) describe electroneutral antiport, whereas the light-scattering experiments (shrinkage and swelling of rods upon hypertonic shocks with various electrolytes) reveal electrogenic uniport. Electroneutral symport of ions (salt transport) does not take place without addition of external ionophores and application of salts of weak acids. 1. Intact rods recover from a hypertonic shock in the presence of FCCP when lithium, sodium and potassium acetate are applied, but not when ammonium chloride, calcium and magnesium acetate are used. This indicates that the plasma membrane of isolated intact cattle rods is relatively permeable to net transport of Na+, Li+ and K+, and relatively impermeable to net transport of Cl-, Mg2+ and Ca2+ under conditions that do not give rise to diffusion potentials. 2. Rapid (t1/2 exchange diffusion of internal 45Ca with external Na+, Ca2+, Sr2+ and Ba2+, respectively. 3. All tested cations lower the rate of 45Ca uptake. The latter can be described by a single rate constant indicating a homogeneous rod preparation and a homogeneous endogenous Ca2+ pool. However, only those cations which stimulate 45Ca efflux from preloaded rods lower the final equilibrium of 45Ca uptake. Except for the effects of K+, Rb+ and Cs+ the reduction of the rate of 45Ca uptake by external cations appears to arise from competition for a common site on the plasms membrane. The observed affinities for this site do not correlate with actual transport (as indicated by the ability to stimulate 45Ca efflux). 4. K+ increases the affinity of the exchange diffusion system to Ca2+ from 1 microM to 0.15 microM and changes the relative affinities with respect to Ca2+ for the

  2. Follow-up of pulmonary perfusion recovery after embolism

    International Nuclear Information System (INIS)

    Palla, A.; Donnamaria, V.; Petruzzelli, S.; Giuntini, C.

    1986-01-01

    Blood flow recovery in a group of 69 patients with pulmonary embolism was followed by serial lung scans over a six month period. Each patient underwent perfusion lung scan at diagnosis then 7, 30 and 180 days later; i.v. heparin was systematically administered for one week after diagnosis, followed by oral warfarin for six months. Blood flow impairment was evaluated by assessing the total number of unperfused lung segments (ULS), as calculated on both lateral views at each scan. The number of ULS was significantly reduced at each interval (P<0.001), ranging from 8.4±3.3 at diagnosis to 3.6±2.7 six months later; most of the recovery (79%) occurred within the first month. No patient had complete restoration of pulmonary blood flow during the whole follow-up period. No difference was found between the number of ULS in right lung versus that in left lung at each interval. Recovery of blood flow was heavily affected by coexisting cardiac or pulmonary disease. In fact, those patients with underlying cardiopulmonary disease (49.2% of the total) showed significantly smaller perfusion improvement after six months (P<0.001). Eight patients (6 with and 2 without cardiopulmonary disease) had clinical and scintigraphic evidence of recurrent embolism during the follow-up period

  3. Vasoactive mediators and splanchnic perfusion.

    Science.gov (United States)

    Reilly, P M; Bulkley, G B

    1993-02-01

    To provide an overview of the splanchnic hemodynamic response to circulatory shock. Previous studies performed in our own laboratory, as well as a computer-assisted search of the English language literature (MEDLINE, 1966 to 1991), followed by a selective review of pertinent articles. Studies were selected that demonstrated relevance to the splanchnic hemodynamic response to circulatory shock, either by investigating the pathophysiology or documenting the sequelae. Article selection included clinical studies as well as studies in appropriate animal models. Pertinent data were abstracted from the cited articles. The splanchnic hemodynamic response to circulatory shock is characterized by a selective vasoconstriction of the mesenteric vasculature mediated largely by the renin-angiotensin axis. This vasospasm, while providing a natural selective advantage to the organism in mild-to-moderate shock (preserving relative perfusion of the heart, kidneys, and brain), may, in more severe shock, cause consequent loss of the gut epithelial barrier, or even hemorrhagic gastritis, ischemic colitis, or ischemic hepatitis. From a physiologic standpoint, nonpulsatile cardiopulmonary bypass, a controlled form of circulatory shock, has been found experimentally to significantly increase circulating levels of angiotensin II, the hormone responsible for this selective splanchnic vasoconstriction. While angiotensin II has been viewed primarily as the mediator responsible for the increased total vascular resistance seen during (and after) cardiopulmonary bypass, it may also cause the disproportionate decrease in mesenteric perfusion, as measured in human subjects by intraluminal gastric tonometry and galactose clearance by the liver, as well as the consequent development of the multiple organ failure syndrome seen in 1% to 5% of patients after cardiac surgery.

  4. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    International Nuclear Information System (INIS)

    Lee, Won Yong; Lee, Ki Hyeong; Yoon, Byung Woo; Lee, Sang Bok; Jeon, Beom S.; Lee, Kyung Han; Lee, Myung Chul

    1996-01-01

    Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p 0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

  5. Segmented trapped vortex cavity

    Science.gov (United States)

    Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

    2010-01-01

    An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

  6. Pavement management segment consolidation

    Science.gov (United States)

    1998-01-01

    Dividing roads into "homogeneous" segments has been a major problem for all areas of highway engineering. SDDOT uses Deighton Associates Limited software, dTIMS, to analyze life-cycle costs for various rehabilitation strategies on each segment of roa...

  7. The value of myocardial perfusion imaging in differentiating between idiopathic dilated cardiomyopathy from the ischemic form

    International Nuclear Information System (INIS)

    Fad, A.; Emami, F.; Eftekhari, M.; Saghari, M.; Fallahi, B.; Beiki, D.; Tkavar, A.

    2004-01-01

    Introduction: differentiating between ischemic cardiomyopathy and idiopathic dilated cardiomyopathy is important as coronary revascularization can improve prognosis in the ischemic subgroup. Due to inherent problems of coronary angiography in patients with depressed ejection fraction introducing a noninvasive tool to diagnose those who will benefit from angiography seems to be rewarding. We examined usefulness of myocardial perfusion scan in this group of patients. Materials and methods: study was performed on 64 patients (62 male and 2 female) aged 57.1 ± 6.7 y (mean ± SD) all with dilation of the left ventricular cavity and ejection fraction less than 40 % by echocardiography. Myocardial perfusion scan was performed in stress and rest phases. All the patients had coronary angiography which was used as the gold standard test. On each set of images, heart was arbitrary divided into 17 segments and perfusion abnormality in each segment was scored by a 5 grade scoring system (0-4). Summed stress Score was used as the scan criteria to differentiate dilated ischemic from idiopathic cardiomyopathy. Scores more than 17 were considered ischemic, and less than that, idiopathic. Results were compared with angiography. Results: from total 40 cases of ischemic cardiomyopathy (proved by angiography) 39 were correctly diagnosed by scan and only one case was mis categorized as idiopathic dilated cardiomyopathy . All 24 cases of idiopathic dilated cardiomyopathy were correctly diagnosed by scintigraphy. Sensitivity, specificity, positive predictive value, and negative predictive value of myocardial perfusion imaging for discrimination between ischemic and idiopathic dilated cardiomyopathy were 97.5 %, 100 %, 100 %, and 96 % respectively. Conclusion: Considering excellent accuracy of myocardial perfusion scan with scoring system in discrimination of ischemic dilated cardiomyopathy from idiopathic cardiomyopathy, this noninvasive test could be considered the main diagnostic test

  8. Speaker segmentation and clustering

    OpenAIRE

    Kotti, M; Moschou, V; Kotropoulos, C

    2008-01-01

    07.08.13 KB. Ok to add the accepted version to Spiral, Elsevier says ok whlile mandate not enforced. This survey focuses on two challenging speech processing topics, namely: speaker segmentation and speaker clustering. Speaker segmentation aims at finding speaker change points in an audio stream, whereas speaker clustering aims at grouping speech segments based on speaker characteristics. Model-based, metric-based, and hybrid speaker segmentation algorithms are reviewed. Concerning speaker...

  9. Spinal segmental dysgenesis

    Directory of Open Access Journals (Sweden)

    N Mahomed

    2009-06-01

    Full Text Available Spinal segmental dysgenesis is a rare congenital spinal abnormality , seen in neonates and infants in which a segment of the spine and spinal cord fails to develop normally . The condition is segmental with normal vertebrae above and below the malformation. This condition is commonly associated with various abnormalities that affect the heart, genitourinary, gastrointestinal tract and skeletal system. We report two cases of spinal segmental dysgenesis and the associated abnormalities.

  10. Myocardial perfusion after prolonged submaximal exercise in patients with coronary artery disease

    International Nuclear Information System (INIS)

    Flotats, A.; Mena, E.; Camacho, V.; Tembl, A.; Hernandez, M.A.; Estorch, M.; Carrio, I.; Serra-Grima, R.

    2002-01-01

    Aim: Exercise training in patients with coronary artery disease (CAD) has established benefits. We assessed myocardial perfusion after submaximal but prolonged exercise in patients with CAD, who were enrolled in supervised exercise rehabilitation programs. Material and Methods: Nine patients with CAD enrolled in supervised exercise rehabilitation programs (7 men, 2 women; mean age 54±9 years), 7 with prior AMI and 2 with re-vascularized (CABG) multiple vessel disease, were encouraged to walk/run actively around the perimeter of our Hospital during the annual social sporting event organised in our Institution. Patients were studied by means of perfusion Tc-99m tetrofosmin SPECT imaging after prolonged exercise and at rest (gated SPECT), for two consecutive years. All patients remained symptom free during this interval period. Quantitative analysis was performed dividing polar map images in 13 segments. Tracer activity 9% in the resting image. The analysis was focused on those segments showing perfusion defects. Results: No symptoms other than fatigue were registered during prolonged exercise (range 1-2 hr). There were no significant differences in distance covered (7,462±3,031 m vs. 8,456±2,998 m), heart rate (92±11 bpm vs. 85±13 bpm) and rate-pressure product at the end of exercise (10,804±2,467 vs. 10,403±2,955) or gated SPECT calculated LVEF (44%±19 vs. 46%±20) between the two consecutive annual sporting events. Tracer activity in segments with perfusion defects did not significantly differ between both events. Overall agreement between both examinations regarding patient classification as having scar/ischemia was 77% (kappa=0.49). There was one patient who showed partial reversibility in three segments, consistent with mild anteroapical ischemia, only in the first examination. On the other hand, another patient showed reversibility in one segment (medium septum), only in the second examination, when he covered a distance 1.3 times superior. Conclusions

  11. Regulation of gut hormone secretion. Studies using isolated perfused intestines

    DEFF Research Database (Denmark)

    Svendsen, Berit; Holst, Jens Juul.

    2016-01-01

    hormones is highly increased after gastric bypass operations, which have turned out to be an effective therapy of not only obesity but also type 2 diabetes. These effects are likely to be due, at least in part, to increases in the secretion of these gut hormones (except GIP). Therefore, stimulation...... of the endogenous hormone represents an appealing therapeutic strategy, which has spurred an interest in understanding the regulation of gut hormone secretion and a search for particularly GLP-1 and PYY secretagogues. The secretion of the gut hormones is stimulated by oral intake of nutrients often including...

  12. Dynamic CT of portal hypertensive gastropathy: significance of transient gastric perfusion defect sign

    International Nuclear Information System (INIS)

    Kim, T.U.; Kim, S.; Woo, S.K.; Lee, J.W.; Lee, T.H.; Jeong, Y.J.; Heo, J.

    2008-01-01

    Aim: To evaluate the 'transient gastric perfusion defect' sign as a way of diagnosing portal hypertensive gastropathy (PHG) on multidetector computed tomography (CT). Materials and methods: Ninety-two consecutive patients with cirrhosis underwent three-phase CT and endoscopy. Endoscopy was performed within 3 days of the CT examination. As controls, 92 patients without clinical evidence of chronic liver diseases who underwent CT and endoscopy were enrolled; the findings at endoscopy were used as a reference standard for patients with PHG. Two radiologists who were unaware of the results of the endoscopy retrospectively interpreted the CT images. PHG was diagnosed on dynamic CT if the transient gastric perfusion defect sign was present. The transient gastric perfusion defect was defined as the presence of transient, segmental or subsegmental hypo-attenuating mucosa in the fundus or body of the stomach on hepatic arterial imaging that returned to normal attenuation on portal venous or equilibrium-phase imaging. The frequency of the transient gastric perfusion defect sign was compared between these two groups using Fisher's exact test. The frequency, sensitivity, specificity, positive predictive values, and negative predictive values of the transient gastric perfusion defect sign were also compared between patients with PHG and without PHG in the cirrhosis group. Results: Nine patients of 92 patients with cirrhosis were excluded because of previous procedure or motion artifact; the remaining 83 patients with cirrhosis were evaluated. In the cirrhosis group, 40 (48.1%) of 83 patients showed the transient gastric perfusion defect sign. In the control group, none of the 92 patients showed the transient gastric perfusion defect sign. In the cirrhotic group, the frequency of the transient gastric perfusion defect sign was significantly higher in the patients with PHG (75%, 36/48) than in patients without PHG (11.4%, 4/35). The sensitivity, specificity, positive predictive

  13. Assessment of non-typical worsening of myocardial perfusion in rest in comparison to stress in 99mTc-MIBI SPECT studies. Preliminary report

    International Nuclear Information System (INIS)

    Dabrowski, A.; Szumilak, B.; Wnuk, J.; Konieczna, S.; Teresinska, A.

    2002-01-01

    Worsening of regional rest perfusion in comparison to stress perfusion, observed in a few percentage of myocardial perfusion 99m Tc-MIBI SPECT studies, does not have an easy clinical interpretation. Also, no reports evaluating the relationship between worsening and technical SPECT study conditions are available. The goal of our study is: 1) to assess the reproducibility of this non-typical effect - by repeating the rest study on separate day after new MIBI injection; 2) to assess reproducibility of this effect in rest perfusion images performed at different time points after one MIBI injection; 3) to propose the most probable clinical explanation for this effect. Up to now, 20 patients (100 predicted altogether) with rest perfusion worsening in routine stress-rest 99m Tc-MIBI SPECT perfusion imaging were studied. The group was clinically in homogeneous (7 patients with suspected coronary artery disease (CAD), 4 patients with CAD and no myocardial infarction (MI), 8 patients after MI, and 1 patient with developmental anomaly). Within 14 days, rest study was repeated, with data acquisition performed at 1 h and 3 hrs after MIBI injection. Regional myocardial perfusion was evaluated qualitatively, in 17 segments of the LV and compared among stress and all the three rest (BAD-I, BAD-II, BAD-III) studies. In 175 segments there was perfusion worsening in at least one of the three rest studies. In the highest percentage of these segments (n=53, 30%, ), worsening was present in all rest studies. Among stress defects with perfusion worsening in BAD-I, the highest percentage (55%, ) presented worsening also in BAD-II (performed after separate injection of MIBI, but like in BAD-I also 1 h after injection), significantly lower percentage - persistent defect in BAD-II (25%, ), and some smaller percentage - transient defect in BAD-II (20%, ). In segments with perfusion worsening present in one of the rest studies, our preliminary results show: 1) the highest probability of

  14. Dynamic contrast enhanced MRI for perfusion quantification

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke

    2002-01-01

    Magnetic resonance imaging, during bolus passage of a paramagnetic contrast agent, is used world-wide to obtain parameters that reflect the pathological state of tissue. Abnormal perfusion occurs in diseases such as stoke and tumour. Consequently, perfusion quantication could have signi cant...... clinical value both in diagnosis and treatment of such pathologies. One approach for perfusion quanti cation involves using the contrast mechanism that a ects the transverse relaxation rates of the magnetization, R2 or R 2 , since this provides the most pronounced effect. However, the linearity between...

  15. Automatic Melody Segmentation

    NARCIS (Netherlands)

    Rodríguez López, Marcelo

    2016-01-01

    The work presented in this dissertation investigates music segmentation. In the field of Musicology, segmentation refers to a score analysis technique, whereby notated pieces or passages of these pieces are divided into “units” referred to as sections, periods, phrases, and so on. Segmentation

  16. The functional state of perfused liver tissue in X-ray irradiated rats

    International Nuclear Information System (INIS)

    Borovikova, G.V.; Dokshina, G.A.; Lapteva, T.A.

    1981-01-01

    The results of studying the functional state of perfused liver tissue isolated from rates after irradiation in the 18.06x10 - 2 Kl/kg dose, which has been estimated by transamination process rate catalized alanine-(KF 2.6x1.2, ALT and aspartate by aminotransferases (KF 2.6x1.1, ACT), gluconeogenesis and urea production intensity presented. When comparing the results obtained on the perfused liver deprived of homeostatic body effects it has been found that the liver isolated from the body for the first 24 hours of the radiation sickness development possesses a higher radiation activity which manifests itself in intensification of the processes of gluconeogenesis and transamination with substrate addition. The third 24 hours upon irradiation in the isolated liver the intensity of the gluconeogenesis and transamination processes is attenuated

  17. Functional state of perfused liver tissue in X-ray irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Borovikova, G.V.; Dokshina, G.A.; Lapteva, T.A. (Tomskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Biologii i Biofiziki)

    1981-01-01

    The results of studying the functional state of perfused liver tissue isolated from rats after irradiation in the 18.06x10/sup -2/ Kl/kg dose, which has been estimated by transamination process rate catalized alanine-(KF 2.6x1.2, ALT and aspartate by aminotransferases (KF 2.6x1.1, ACT), gluconeogenesis and urea production intensity presented. When comparing the results obtained on the perfused liver deprived of homeostatic body effects it has been found that the liver isolated from the body for the first 24 hours of the radiation sickness development possesses a higher radiation activity which manifests itself in intensification of the processes of gluconeogenesis and transamination with substrate addition. The third 24 hours upon irradiation in the isolated liver the intensity of the gluconeogenesis and transamination processes is attenuated.

  18. Value of dynamic susceptibility contrast perfusion MRI in the acute phase of transient global amnesia.

    Directory of Open Access Journals (Sweden)

    Alex Förster

    Full Text Available Transient global amnesia (TGA is a transitory, short-lasting neurological disorder characterized by a sudden onset of antero- and retrograde amnesia. Perfusion abnormalities in TGA have been evaluated mainly by use of positron emission tomography (PET or single-photon emission computed tomography (SPECT. In the present study we explore the value of dynamic susceptibility contrast perfusion-weighted MRI (PWI in TGA in the acute phase.From a MRI report database we identified TGA patients who underwent MRI including PWI in the acute phase and compared these to control subjects. Quantitative perfusion maps (cerebral blood flow (CBF and volume (CBV were generated and analyzed by use of Signal Processing In NMR-Software (SPIN. CBF and CBV values in subcortical brain regions were assessed by use of VOI created in FIRST, a model-based segmentation tool in the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB Software Library (FSL.Five TGA patients were included (2 men, 3 women. On PWI, no relevant perfusion alterations were found by visual inspection in TGA patients. Group comparisons for possible differences between TGA patients and control subjects showed significant lower rCBF values bilaterally in the hippocampus, in the left thalamus and globus pallidus as well as bilaterally in the putamen and the left caudate nucleus. Correspondingly, significant lower rCBV values were observed bilaterally in the hippocampus and the putamen as well as in the left caudate nucleus. Group comparisons for possible side differences in rCBF and rCBV values in TGA patients revealed a significant lower rCBV value in the left caudate nucleus.Mere visual inspection of PWI is not sufficient for the assessment of perfusion changes in TGA in the acute phase. Group comparisons with healthy control subjects might be useful to detect subtle perfusion changes on PWI in TGA patients. However, this should be confirmed in larger data sets and serial PWI

  19. Observed Influence of Nitroglycerine on Myocardial Perfusion Scintigraphy in Patients with Multiple Vessel Coronary Artery Disease and Well-Developed Collaterals

    International Nuclear Information System (INIS)

    Rasulova, Nigora; Nazirova, Lyudmila; Akhmedov, Khasan; Akhmedova, Dilyafruz; Djalalov, Farrukh; Seydaliev, Amet; Iskandarov, Farkhod; Kok, T. Y.

    2012-01-01

    The objective of this scientific work was to evaluate the extent and severity of perfusion abnormalities on myocardial perfusion scintigraphy (MPS) at rest and with sublingual nitroglycerine, in relation to the presence and anatomical location of collaterals demonstrated by selective coronary angiography (SCA). Twenty-eight patients with unstable angina underwent selective coronary angiography. Eighteen of them were diagnosed with myocardial infarction (MI) 2–15 days prior to examination. Presence or absence of collaterals was noted, with anatomical depiction of donor and recipient arteries as well as evaluation of degree of collateral flow. As an inclusion criterion, collateral flow had to be grade 2 (partial epicardial filling of the occluded artery) or 3 (complete epicardial filling of the occluded artery) in accordance with the Rentrop collateral flow classification. Flow was noted as follows: Complete antegrade (CA), complete retrograde (CR), partial antegrade (PA), and partial retrograde (PR). Myocardial perfusion scintigraphy using Tc-99m Sestamibi at rest and after sublingual administration of nitroglycerine was performed according to a 2-day protocol. Perfusion abnormalities, which were quantified using the 20-segments model and visual 5-point system (0, normal perfusion; 4, absent perfusion), were analyzed according to donor's and recipient's territories, as well as territories with limited or without collateral flow (PA/PR, grade 0–1 flow). A total of 84 arteries were analyzed, with stenosis in 79 of them. Arteries were divided into three groups: Donors (group I), recipients (group II), and arteries with limited or without collaterals (group III). In group I, there were 28 donor arteries, with mean severity of stenosis 71.3 ± 0.65%. In group II, there were 36 recipient arteries and mean severity of stenosis was 94.8 ± 0.26%. In group III, there were 20 arteries, and all of them had either no or poorly developed collaterals (mean severity

  20. Prevalence of symptomatic and silent stress-induced perfusion defects in diabetic patients with suspected coronary artery disease referred for myocardial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Prior, John O.; Calcagni, Maria-Lucia; Bischof Delaloye, Angelika; Monbaron, David; Ruiz, Juan; Koehli, Melanie

    2005-01-01

    Silent myocardial ischaemia - as evaluated by stress-induced perfusion defects on myocardial perfusion scintigraphy (MPS) in patients without a history of chest pain - is frequent in diabetes and is associated with increased rates of cardiovascular events. Its prevalence has been determined in asymptomatic diabetic patients, but remains largely unknown in diabetic patients with suspected coronary artery disease (CAD) in the clinical setting. In this study we therefore sought (a) to determine the prevalence of symptomatic and silent perfusion defects in diabetic patients with suspected CAD and (b) to characterise the eventual predictors of abnormal perfusion. The patient population comprised 133 consecutive diabetic patients with suspected CAD who had been referred for MPS. Studies were performed with exercise (41%) or pharmacological stress testing (1-day protocol, 99m Tc-sestamibi, 201 Tl or both). We used semi-quantitative analysis (20-segment polar maps) to derive the summed stress score (SSS) and the summed difference score (SDS). Abnormal MPS (SSS≥4) was observed in 49 (37%) patients (SSS=4.9±8.4, SDS=2.4±4.7), reversible perfusion defects (SDS≥2) in 40 (30%) patients [SSS=13.3±10.9; SDS=8.0±5.6; 20% moderate to severe (SDS>4), 7% multivessel] and fixed defects in 21 (16%) patients. Results were comparable between patients with and patients without a history of chest pain. Of 75 patients without a history of chest pain, 23 (31%, 95% CI=21-42%) presented reversible defects (SSS=13.9±11.3; SDS=7.4±1.2), indicative of silent ischaemia. Reversible defects were associated with inducible ST segment depression during MPS stress (odds ratio (OR)=3.2, p<0.01). Fixed defects were associated with erectile dysfunction in males (OR=3.7, p=0.02) and lower aspirin use (OR=0.25, p=0.02). Silent stress-induced perfusion defects occurred in 31% of the patients, a rate similar to that in patients with a history of chest pain. MPS could identify these patients with a

  1. Prevalence of symptomatic and silent stress-induced perfusion defects in diabetic patients with suspected coronary artery disease referred for myocardial perfusion scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Prior, John O.; Calcagni, Maria-Lucia; Bischof Delaloye, Angelika [Centre Hospitalier Universitaire Vaudois (CHUV University Hospital), Division of Nuclear Medicine, Lausanne (Switzerland); Monbaron, David; Ruiz, Juan [Centre Hospitalier Universitaire Vaudois (CHUV University Hospital), Division of Endocrinology, Diabetology and Metabolism, Lausanne (Switzerland); Koehli, Melanie [Centre Hospitalier Universitaire Vaudois (CHUV University Hospital), Division of Nuclear Medicine, Lausanne (Switzerland); Centre Hospitalier Universitaire Vaudois (CHUV University Hospital), Division of Endocrinology, Diabetology and Metabolism, Lausanne (Switzerland)

    2005-01-01

    Silent myocardial ischaemia - as evaluated by stress-induced perfusion defects on myocardial perfusion scintigraphy (MPS) in patients without a history of chest pain - is frequent in diabetes and is associated with increased rates of cardiovascular events. Its prevalence has been determined in asymptomatic diabetic patients, but remains largely unknown in diabetic patients with suspected coronary artery disease (CAD) in the clinical setting. In this study we therefore sought (a) to determine the prevalence of symptomatic and silent perfusion defects in diabetic patients with suspected CAD and (b) to characterise the eventual predictors of abnormal perfusion. The patient population comprised 133 consecutive diabetic patients with suspected CAD who had been referred for MPS. Studies were performed with exercise (41%) or pharmacological stress testing (1-day protocol, {sup 99m}Tc-sestamibi, {sup 201}Tl or both). We used semi-quantitative analysis (20-segment polar maps) to derive the summed stress score (SSS) and the summed difference score (SDS). Abnormal MPS (SSS{>=}4) was observed in 49 (37%) patients (SSS=4.9{+-}8.4, SDS=2.4{+-}4.7), reversible perfusion defects (SDS{>=}2) in 40 (30%) patients [SSS=13.3{+-}10.9; SDS=8.0{+-}5.6; 20% moderate to severe (SDS>4), 7% multivessel] and fixed defects in 21 (16%) patients. Results were comparable between patients with and patients without a history of chest pain. Of 75 patients without a history of chest pain, 23 (31%, 95% CI=21-42%) presented reversible defects (SSS=13.9{+-}11.3; SDS=7.4{+-}1.2), indicative of silent ischaemia. Reversible defects were associated with inducible ST segment depression during MPS stress (odds ratio (OR)=3.2, p<0.01). Fixed defects were associated with erectile dysfunction in males (OR=3.7, p=0.02) and lower aspirin use (OR=0.25, p=0.02). Silent stress-induced perfusion defects occurred in 31% of the patients, a rate similar to that in patients with a history of chest pain. MPS could identify

  2. Myocardial perfusion scintigraphy - possibilities of diagnosing CAD

    International Nuclear Information System (INIS)

    Tsonevska, A.

    1998-01-01

    A reviewing the diagnostic methods used in the intricate process of evaluating CAD patients in a attempt to establish the role played by radionuclide methods in the diagnostic strategy is done. The perfusion cardiotropic radiopharmaceuticals used and the various methods of evaluating myocardial are discussed. Although 210 Tl-chloride is the most widely used myocardial perfusion agent, recently 99m Tc-MIBI is proposed as an alternative because of its advantages. Myocardial perfusion assessment is done by various techniques depending on the specific aim, each of them having its proper advantages and shortcomings. The inference is reached that regardless of the routine practical implementation of myocardial perfusion scintigraphy and comprehensive studies along this line in course, there are problems still not well enough clarified awaiting solution

  3. Regional myocardial perfusion of cardioplegic solutions

    International Nuclear Information System (INIS)

    Eugene, J.; Lyons, K.P.; Ott, R.A.; Gelezunas, V.L.; Chang, C.W.; Kowall, M.G.; Haiduc, N.J.

    1987-01-01

    We compared the regional myocardial perfusion of blood cardioplegic solution (BCP) and crystalloid cardioplegic solution (CCP) in 14 mongrel dogs. Cardiopulmonary bypass was established at 28 degrees C, and a hydraulic occluder was placed around the proximal left anterior descending (LAD) coronary artery. In group 1 (N = 7) collateral coronary arteries were ligated; in group 2 (N = 7) collateral coronary arteries were left in situ. After the aorta was clamped, BCP and CCP were alternately perfused at 200 ml/min. The occluder was inflated to produce moderate, severe, and critical LAD stenosis, and regional perfusion was measured by xenon-133 washout with the Silicon Avalanche Radiation Detector. BCP infusion produced a consistently higher aortic pressure, but CCP flow was better than BCP flow under all conditions, particularly without coronary collaterals. Regional myocardial perfusion of CCP is superior to BCP

  4. MRI of pulmonary perfusion; MRT der Lungenperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany); Risse, F.; Semmler, W. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Medizinische Physik in der Radiologie, Heidelberg (Germany); Schoenberg, S.O.; Reiser, M.F. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Kauczor, H.-U. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany)

    2006-04-15

    Lung perfusion is a crucial prerequisite for effective gas exchange. Quantification of pulmonary perfusion is important for diagnostic considerations and treatment planning in various diseases of the lungs. Besides disorders of pulmonary vessels such as acute pulmonary embolism and pulmonary hypertension, these also include diseases of the respiratory tract and lung tissue as well as pulmonary tumors. This contribution presents the possibilities and technical requirements of MRI for diagnostic work-up of pulmonary perfusion. (orig.) [German] Die Perfusion der Lunge ist eine entscheidende Voraussetzung fuer einen effektiven Gasaustausch. Die Bestimmung der Lungenperfusion ist bei verschiedenen Erkrankungen der Lunge fuer Diagnostik und Therapieplanung bedeutsam. Hierzu zaehlen neben Erkrankungen der Lungengefaesse wie akute Lungenembolie und pulmonale Hypertension ebenso Erkrankungen der Atemwege, des Lungengeruests und Lungentumoren. In diesem Beitrag werden die Moeglichkeiten und technischen Voraussetzungen der MRT zur Diagnostik der Lungenperfusion dargestellt. (orig.)

  5. Vicarious audiovisual learning in perfusion education.

    Science.gov (United States)

    Rath, Thomas E; Holt, David W

    2010-12-01

    Perfusion technology is a mechanical and visual science traditionally taught with didactic instruction combined with clinical experience. It is difficult to provide perfusion students the opportunity to experience difficult clinical situations, set up complex perfusion equipment, or observe corrective measures taken during catastrophic events because of patient safety concerns. Although high fidelity simulators offer exciting opportunities for future perfusion training, we explore the use of a less costly low fidelity form of simulation instruction, vicarious audiovisual learning. Two low fidelity modes of instruction; description with text and a vicarious, first person audiovisual production depicting the same content were compared. Students (n = 37) sampled from five North American perfusion schools were prospectively randomized to one of two online learning modules, text or video.These modules described the setup and operation of the MAQUET ROTAFLOW stand-alone centrifugal console and pump. Using a 10 question multiple-choice test, students were assessed immediately after viewing the module (test #1) and then again 2 weeks later (test #2) to determine cognition and recall of the module content. In addition, students completed a questionnaire assessing the learning preferences of today's perfusion student. Mean test scores from test #1 for video learners (n = 18) were significantly higher (88.89%) than for text learners (n = 19) (74.74%), (p audiovisual learning modules may be an efficacious, low cost means of delivering perfusion training on subjects such as equipment setup and operation. Video learning appears to improve cognition and retention of learned content and may play an important role in how we teach perfusion in the future, as simulation technology becomes more prevalent.

  6. Improved exercise myocardial perfusion during lidoflazine therapy

    International Nuclear Information System (INIS)

    Shapiro, W.; Narahara, K.A.; Park, J.

    1983-01-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a study of 6 patients with severe classic angina pectoris, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise

  7. Measurement of myocardial perfusion using magnetic resonance

    DEFF Research Database (Denmark)

    Fritz-Hansen, T.; Jensen, L.T.; Larsson, H.B.

    2008-01-01

    Cardiac magnetic resonance imaging (MRI) has evolved rapidly. Recent developments have made non-invasive quantitative myocardial perfusion measurements possible. MRI is particularly attractive due to its high spatial resolution and because it does not involve ionising radiation. This paper reviews...... myocardial perfusion imaging with MR contrast agents: methods, validation and experiences from clinical studies. Unresolved issues still restrict the use of these techniques to research although clinical applications are within reach Udgivelsesdato: 2008/12/8...

  8. Ventilation-perfused studies using SPECT

    International Nuclear Information System (INIS)

    Zwijnenburg, A.

    1989-01-01

    A method for the quantitative analysis of ventilation-perfusion SPECT studies is decribed and an effort is made to evaluate its usefullness. The technical details of the emthod are described. In the the transaxial reconstructions of the tomographic studies the contour of the lungs is detected and regional values of lung volume, ventilation, perfusion and ventilation-perfusion ratios are calculated. The method is operator independent. The lung volume calculations from the SPECT studies are validated by comparing them with lung volume measurements using the helium dilution technique. A good correlation (r=0.91) was found between the two volumes. SPECT volume was greater than the volume measured with helium dilution, which was attributed to non-gas-containing structures in the. lungs. The use of ventilation-perfusion ratio SPECT is described to evaluate the effect of ionizing radiation on the lungs in patients treated with mantle field irradiation for Hodgkin's disease. Perfusion changes appear as early as 2 months after the start of irradiation. Ventilation changes appear later and relatively minor. No changes are seen outside the radiation portals. The ventilation-perfusion inequality in pulmonary sarcoidosis is treated. It is suggested that the decrease D LCO in these patients may be partly due to an even distribution of ventilation perfusion ratios. An effort is made to establish the properties of a new tracer used for the assessment of the metabolic function of the pulmonary endothelium. The lung uptake of I-123 IMP mimics the distribution of a perfusion tracer and it is suggested that this tracer may be useful for the early detection of pulmonary vascular damage, even when blood flow is still intact. Some aspects of the use of Kr-81m as a ventilation tracer are discussed as well as the effect of noise on Kr-81m SPECT reconstructions. (author). 146 refs.; 39 figs.; 8 tabs

  9. Variation in Perfusion Strategies for Neonatal and Infant Aortic Arch Repair: Contemporary Practice in the STS Congenital Heart Surgery Database.

    Science.gov (United States)

    Meyer, David B; Jacobs, Jeffrey P; Hill, Kevin; Wallace, Amelia S; Bateson, Brian; Jacobs, Marshall L

    2016-09-01

    Regional cerebral perfusion (RCP) is used as an adjunct or alternative to deep hypothermic circulatory arrest (DHCA) for neonates and infants undergoing aortic arch repair. Clinical studies have not demonstrated clear superiority of either strategy, and multicenter data regarding current use of these strategies are lacking. We sought to describe the variability in contemporary practice patterns for use of these techniques. The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010-2013) was queried to identify neonates and infants whose index operation involved aortic arch repair with cardiopulmonary bypass. Perfusion strategy was classified as isolated DHCA, RCP (with less than or equal to ten minutes of DHCA), or mixed (RCP with more than ten minutes of DHCA). Data were analyzed for the entire cohort and stratified by operation subgroups. Overall, 4,523 patients (105 centers) were identified; median age seven days (interquartile range: 5.0-13.0). The most prevalent perfusion strategy was RCP (43%). Deep hypothermic circulatory arrest and mixed perfusion accounted for 32% and 16% of cases, respectively. In all, 59% of operations involved some period of RCP. Regional cerebral perfusion was the most prevalent perfusion strategy for each operation subgroup. Neither age nor weight was associated with perfusion strategy, but reoperations were less likely to use RCP (31% vs 45%, P RCP and DHCA in the RCP group was longer than the DHCA time in the DHCA group (45 vs 36 minutes, P neonates and infants. In contemporary practice, RCP is the most prevalent perfusion strategy for these procedures. Use of DHCA is also common. Further investigation is warranted to ascertain possible relative merits of the various perfusion techniques. © The Author(s) 2016.

  10. Multiple-indicator dilution technique for characterization of normal and retrograde flow in once-through rat liver perfusions

    International Nuclear Information System (INIS)

    St-Pierre, M.V.; Schwab, A.J.; Goresky, C.A.; Lee, W.F.; Pang, K.S.

    1989-01-01

    The technique of normal and retrograde rat liver perfusion has been widely used to probe zonal differences in drug-metabolizing activities. The validity of this approach mandates the same tissue spaces being accessed by substrates during both normal and retrograde perfusions. Using the multiple-indicator dilution technique, we presently examine the extent to which retrograde perfusion alters the spaces accessible to noneliminated references. A bolus dose of 51Cr-labeled red blood cells, 125I-albumin, 14C-sucrose and 3H2O was injected into the portal (normal) or hepatic (retrograde) vein of rat livers perfused at 10 ml per min per liver. The outflow perfusate was serially collected over 220 sec to characterize the transit times and the distribution spaces of the labels. During retrograde perfusion, red blood cells, albumin and sucrose profiles peaked later and lower than during normal perfusion, whereas the water curves were similar. The transit times of red blood cells, albumin and sucrose were longer (p less than 0.005), whereas those for water did not change. Consequently, retrograde flow resulted in significantly larger sinusoidal blood volumes (45%), albumin Disse space (42%) and sucrose Disse space (25%) than during normal flow, whereas the distribution spaces for total and intracellular water remained unaltered. The distension of the vascular tree was confirmed by electron microscopy, by which occasional isolated foci of widened intercellular recesses and spaces of Disse were observed. Cellular ultrastructure was otherwise unchanged, and there was no difference found between normal and retrograde perfusion for bile flow rates, AST release, perfusion pressure, oxygen consumption and metabolic removal of ethanol, a substrate with flow-limited distribution, which equilibrates rapidly with cell water (hepatic extraction ratios were virtually identical: normal vs. retrograde, 0.50 vs. 0.48 at 6 to 7.4 mM input concentration)

  11. Quantitative perfusion imaging in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Zoellner, F.G.; Gaa, T.; Zimmer, F.; Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M.

    2016-01-01

    Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [de

  12. Insulin degradation products from perfused rat kidney

    International Nuclear Information System (INIS)

    Duckworth, W.C.; Hamel, F.G.; Liepnieks, J.; Peavy, D.; Frank, B.; Rabkin, R.

    1989-01-01

    The kidney is a major site for insulin metabolism, but the enzymes involved and the products generated have not been established. To examine the products, we have perfused rat kidneys with insulin specifically iodinated on either the A14 or the B26 tyrosine. Labeled material from both the perfusate and kidney extract was examined by Sephadex G50 and high-performance liquid chromatography (HPLC). In perfusate from a filtering kidney, 22% of the insulin-sized material was not intact insulin on HPLC. With the nonfiltering kidney, 10.6% was not intact insulin. Labeled material from HPLC was sulfitolyzed and reinjected on HPLC. By use of 125 I-iodo(A14)-insulin, almost all the degradation products contained an intact A-chain. By use of 125 I-iodo(B26)-insulin, several different B-chain-cleaved products were obtained. The material extracted from the perfused kidney was different from perfusate products but similar to intracellular products from hepatocytes, suggesting that cellular metabolism by kidney and liver are similar. The major intracellular product had characteristics consistent with a cleavage between the B16 and B17 amino acids. This product and several of the perfusate products are also produced by insulin protease suggesting that this enzyme is involved in the degradation of insulin by kidney

  13. CT perfusion study of neck lymph nodes

    International Nuclear Information System (INIS)

    Zhong Jin; Liu Jun; Hua Rui; Qiao Hui; Gong Yi

    2011-01-01

    Objective: To study the CT perfusion features of various lymph nodes in the neck. Methods: Dynamic perfusion CT scanning was performed in 83 neck lymph nodes proved by pathology, including tuberculosis lymph nodes, lymphoma and metastatic lymph nodes. The shapes, blood flow modes, and perfusion parameters of these lymph nodes were compared among 3 groups. Statistical analysis of L/T and CT perfusion parameters was performed by one-way ANOVA and LSD test. Results: The values of MTT of tuberculosis lymph nodes, lymphoma and metastatic lymph nodes were (28.13±5.08), (31.08±5.82), and (11.24±5.31) s, respectively. The MTT of metastatic lymph nodes was statistically lower than that of tuberculosis lymph nodes and lymphoma (P -1 · 100 g -1 , respectively. The values of BV were (24.68±2.84), (25.30±3.16), and (25.15± 8.81) ml·100 g -1 respectively. The values of TTP were (40.90±8.85), (40.67±6.45), and (40.98±6.62) s, respectively. There were no significant differences in L/T, BF, BV and TTP among tuberculosis lymph nodes, lymphoma and metastatic lymph nodes (P>0.05). Conclusion: CT perfusion, especially combination functional imaging with perfusion images may be helpful in judging the nature of neck lymph nodes. (authors)

  14. Homocysteine plasma levels in patients suspected coronary artery disease: Relation to myocardial perfusion image

    International Nuclear Information System (INIS)

    Yao, Z.Y.; He, Q.; Qu, W.

    2002-01-01

    Purpose: Although there is considerable epidemiologic evidence for a relationship between plasma homocysteine (Hcy) levels and coronary artery disease (CAD), not all studies, especially prospective ones have shown such a relationship. The purpose of this study was to investigate a possible association between Hcy plasma levels and myocardial perfusion defect by SPECT in patients suspected CAD. Methods and Materials: A cohort of 238 patients suspected CAD (age: 60.65±10.43, male to female: 172: 66) was examined for Hcy, tetrahydrofolic acid (FH4), vitamine B12 and coronary angiography (CAG). Furthermore, 42 patients also underwent 99m Tc-MIBI myocardial perfusion images (MPI) to assess the myocardial perfusion. Results: There were 69 patients with normal CAG and 63, 60, 42 and 4 patients with 1 vessel, two vessel, 3 vessel and left main coronary stenosis. The plasma Hcy of this group was significantly increased, p 0.05. In patients with >=3 segments myocardial perfusion defect, 10 of them had normal Hcy, and 7 with hyperhomocysteinemia, in patients with 0.05). Conclusion: Our data may indicate that hyperhomocysteinemia represents an independent risk factor in patients with high possibility of CAD rather than a mark of myocardial ischemia or coronary stenosis

  15. The effect of captopril on thallium 201 myocardial perfusion in systemic sclerosis

    International Nuclear Information System (INIS)

    Kahan, A.; Devaux, J.Y.; Amor, B.; Menkes, C.J.; Weber, S.; Venot, A.; Strauch, G.

    1990-01-01

    In systemic sclerosis, abnormalities of myocardial perfusion are common and may be caused by a disturbance of the coronary microcirculation. We evaluated the long-term effect of captopril (75 to 150 mg per day) on thallium 201 myocardial perfusion in 12 normotensive patients with systemic sclerosis. Captopril significantly decreased the mean (+/- SD) number of segments with thallium 201 myocardial perfusion defects (6.5 +/- 1.9 at baseline and 4.4 +/- 2.7 after 1 year of treatment with captopril; p less than 0.02) and increased the mean global thallium score (9.6 +/- 1.7 at baseline and 11.4 +/- 2.1 after captopril; p less than 0.05). In a control group of eight normotensive patients with systemic sclerosis who did not receive captopril, no significant modification in thallium results occurred. Side effects with captopril included hypotension (six patients), taste disturbances (one patient), and skin rash (one patient). These side effects subsided when the dosage was reduced. These findings demonstrate that captopril improves thallium 201 myocardial perfusion in patients with systemic sclerosis and may therefore have a beneficial effect on scleroderma myocardial disease

  16. Dynamic CT myocardial perfusion imaging: performance of 3D semi-automated evaluation software

    Energy Technology Data Exchange (ETDEWEB)

    Ebersberger, Ullrich [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); Heart Center Munich-Bogenhausen, Department of Cardiology and Intensive Care Medicine, Munich (Germany); Marcus, Roy P.; Nikolaou, Konstantin; Bamberg, Fabian [University of Munich, Institute of Clinical Radiology, Munich (Germany); Schoepf, U.J.; Gray, J.C.; McQuiston, Andrew D. [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); Lo, Gladys G. [Hong Kong Sanatorium and Hospital, Department of Diagnostic and Interventional Radiology, Hong Kong (China); Wang, Yining [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Department of Radiology, Beijing (China); Blanke, Philipp [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); University Hospital Freiburg, Department of Diagnostic Radiology, Freiburg (Germany); Geyer, Lucas L. [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); University of Munich, Institute of Clinical Radiology, Munich (Germany); Cho, Young Jun [Medical University of South Carolina, Heart and Vascular Center, Charleston, SC (United States); Konyang University College of Medicine, Department of Radiology, Daejeon (Korea, Republic of); Scheuering, Michael; Canstein, Christian [Siemens Healthcare, CT Division, Forchheim (Germany); Hoffmann, Ellen [Heart Center Munich-Bogenhausen, Department of Cardiology and Intensive Care Medicine, Munich (Germany)

    2014-01-15

    To evaluate the performance of three-dimensional semi-automated evaluation software for the assessment of myocardial blood flow (MBF) and blood volume (MBV) at dynamic myocardial perfusion computed tomography (CT). Volume-based software relying on marginal space learning and probabilistic boosting tree-based contour fitting was applied to CT myocardial perfusion imaging data of 37 subjects. In addition, all image data were analysed manually and both approaches were compared with SPECT findings. Study endpoints included time of analysis and conventional measures of diagnostic accuracy. Of 592 analysable segments, 42 showed perfusion defects on SPECT. Average analysis times for the manual and software-based approaches were 49.1 ± 11.2 and 16.5 ± 3.7 min respectively (P < 0.01). There was strong agreement between the two measures of interest (MBF, ICC = 0.91, and MBV, ICC = 0.88, both P < 0.01) and no significant difference in MBF/MBV with respect to diagnostic accuracy between the two approaches for both MBF and MBV for manual versus software-based approach; respectively; all comparisons P > 0.05. Three-dimensional semi-automated evaluation of dynamic myocardial perfusion CT data provides similar measures and diagnostic accuracy to manual evaluation, albeit with substantially reduced analysis times. This capability may aid the integration of this test into clinical workflows. (orig.)

  17. ST-segment elevation induced by ergometric stress during myocardial perfusion test with {sup 99m}Tc-SESTAMIBI; Supradesnivel ST inducido por stress ergométrico durante el estudio de perfusión miocárdica con {sup 99m}Tc-SESTAMIBI

    Energy Technology Data Exchange (ETDEWEB)

    Pastore, F. A.; Fernández, C. C.; Giovaneti, A.; Malvar, M.; Abud, A.C., E-mail: franciscopastore@gmail.com [Hospital Interzonal De Agudos Eva Perón, Provincia de Buenos Aires (Argentina)

    2014-07-01

    ST-segment elevation provoked by the exercise test is a low prevalence response. Two clinical cases in which such behavior arose during the myocardial technetium-99m-Sestamibi SPECT test are described. Physiopathological considerations in correlation with the bibliography linked to the subject are made. (authors) [Spanish] El supradesnivel del segmento ST inducido por el test de ejercicio es una respuesta de baja prevalencia. Se descri¬ben dos casos clínicos, en los cuales, dicho comporta¬miento se presentó durante el estudio de perfusión mio¬cárdica con tecnecio-99m-Sestamibi SPECT. Se realizan consideraciones fisiopatológicas en corre¬lación con los antecedentes bibliográficos vinculados al tema. (autores)

  18. Measurements on a prototype segmented Clover detector

    CERN Document Server

    Shepherd, S L; Cullen, D M; Appelbe, D E; Simpson, J; Gerl, J; Kaspar, M; Kleinböhl, A; Peter, I; Rejmund, M; Schaffner, H; Schlegel, C; France, G D

    1999-01-01

    The performance of a segmented Clover germanium detector has been measured. The segmented Clover detector is a composite germanium detector, consisting of four individual germanium crystals in the configuration of a four-leaf Clover, housed in a single cryostat. Each crystal is electrically segmented on its outer surface into four quadrants, with separate energy read-outs from nine crystal zones. Signals are also taken from the inner contact of each crystal. This effectively produces a detector with 16 active elements. One of the purposes of this segmentation is to improve the overall spectral resolution when detecting gamma radiation emitted following a nuclear reaction, by minimising Doppler broadening caused by the opening angle subtended by each detector element. Results of the tests with sources and in beam will be presented. The improved granularity of the detector also leads to an improved isolated hit probability compared with an unsegmented Clover detector. (author)

  19. Ex vivo perfusion of human spleens maintains clearing and processing functions.

    Science.gov (United States)

    Buffet, Pierre A; Milon, Geneviève; Brousse, Valentine; Correas, Jean-Michel; Dousset, Bertrand; Couvelard, Anne; Kianmanesh, Reza; Farges, Olivier; Sauvanet, Alain; Paye, François; Ungeheuer, Marie-Noëlle; Ottone, Catherine; Khun, Huot; Fiette, Laurence; Guigon, Ghislaine; Huerre, Michel; Mercereau-Puijalon, Odile; David, Peter H

    2006-05-01

    The spleen plays a central role in the pathophysiology of several potentially severe diseases such as inherited red cell membrane disorders, hemolytic anemias, and malaria. Research on these diseases is hampered by ethical constraints that limit human spleen tissue explorations. We identified a surgical situation--left splenopancreatectomy for benign pancreas tumors--allowing spleen retrieval at no risk for patients. Ex vivo perfusion of retrieved intact spleens for 4 to 6 hours maintained a preserved parenchymal structure, vascular flow, and metabolic activity. Function preservation was assessed by testing the ability of isolated-perfused spleens to retain Plasmodium falciparum-infected erythrocytes preexposed to the antimalarial drug artesunate (Art-iRBCs). More than 95% of Art-iRBCs were cleared from the perfusate in 2 hours. At each transit through isolated-perfused spleens, parasite remnants were removed from 0.2% to 0.23% of Art-iRBCs, a proportion consistent with the 0.02% to 1% pitting rate previously established in artesunate-treated patients. Histologic analysis showed that more than 90% of Art-iRBCs were retained and processed in the red pulp, providing the first direct evidence of a zone-dependent parasite clearance by the human spleen. Human-specific physiologic or pathophysiologic mechanisms involving clearing or processing functions of the spleen can now be experimentally explored in a human tissue context.

  20. Color Segmentation of Homogeneous Areas on Colposcopical Images

    Directory of Open Access Journals (Sweden)

    Kosteley Yana

    2016-01-01

    Full Text Available The article provides an analysis of image processing and color segmentation applied to the problem of selection of homogeneous regions in the parameters of the color model. Methods of image processing such as Gaussian filter, median filter, histogram equalization and mathematical morphology are considered. The segmentation algorithm with the parameters of color components is presented, followed by isolation of the resulting connected component of a binary segmentation mask. Analysis of methods performed on images colposcopic research.

  1. A Kalman Filtering Perspective for Multiatlas Segmentation*

    Science.gov (United States)

    Gao, Yi; Zhu, Liangjia; Cates, Joshua; MacLeod, Rob S.; Bouix, Sylvain; Tannenbaum, Allen

    2016-01-01

    In multiatlas segmentation, one typically registers several atlases to the novel image, and their respective segmented label images are transformed and fused to form the final segmentation. In this work, we provide a new dynamical system perspective for multiatlas segmentation, inspired by the following fact: The transformation that aligns the current atlas to the novel image can be not only computed by direct registration but also inferred from the transformation that aligns the previous atlas to the image together with the transformation between the two atlases. This process is similar to the global positioning system on a vehicle, which gets position by inquiring from the satellite and by employing the previous location and velocity—neither answer in isolation being perfect. To solve this problem, a dynamical system scheme is crucial to combine the two pieces of information; for example, a Kalman filtering scheme is used. Accordingly, in this work, a Kalman multiatlas segmentation is proposed to stabilize the global/affine registration step. The contributions of this work are twofold. First, it provides a new dynamical systematic perspective for standard independent multiatlas registrations, and it is solved by Kalman filtering. Second, with very little extra computation, it can be combined with most existing multiatlas segmentation schemes for better registration/segmentation accuracy. PMID:26807162

  2. [Acute stent thrombosis and reverse transient left ventricular dilatation after performing a single-photon emission computed tomography myocardial perfusion].

    Science.gov (United States)

    Miranda, B; Pizzi, M N; Aguadé-Bruix, S; Domingo, E; Candell-Riera, J

    2015-01-01

    A 63-year-old male patient with a history of stent implantation in the left anterior descending three months before. Due to the presentation of vegetative symptoms, he was referred for gated-SPECT myocardial perfusion. During acquisition of the resting images he presented chest pain and ST segment elevation, so that urgent cardiac catheterization was performed, showing stent thrombosis. Rest perfusion imaging showed a defect in anterior and apical perfusion, more severe and extensive than in the stress images, with striking left ventricular dilatation and a fall in the ejection fraction related to the acute ischemia phenomenon. Intense exercise is associated with a transient activation of the coagulation system and hemodynamic changes that might induce thrombosis, especially in recently implanted coronary stents that probably still have not become completely endothelialized. Copyright © 2014 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  3. Diagnostic performance of semi-quantitative and quantitative stress CMR perfusion analysis: a meta-analysis.

    Science.gov (United States)

    van Dijk, R; van Assen, M; Vliegenthart, R; de Bock, G H; van der Harst, P; Oudkerk, M

    2017-11-27

    Stress cardiovascular magnetic resonance (CMR) perfusion imaging is a promising modality for the evaluation of coronary artery disease (CAD) due to high spatial resolution and absence of radiation. Semi-quantitative and quantitative analysis of CMR perfusion are based on signal-intensity curves produced during the first-pass of gadolinium contrast. Multiple semi-quantitative and quantitative parameters have been introduced. Diagnostic performance of these parameters varies extensively among studies and standardized protocols are lacking. This study aims to determine the diagnostic accuracy of semi- quantitative and quantitative CMR perfusion parameters, compared to multiple reference standards. Pubmed, WebOfScience, and Embase were systematically searched using predefined criteria (3272 articles). A check for duplicates was performed (1967 articles). Eligibility and relevance of the articles was determined by two reviewers using pre-defined criteria. The primary data extraction was performed independently by two researchers with the use of a predefined template. Differences in extracted data were resolved by discussion between the two researchers. The quality of the included studies was assessed using the 'Quality Assessment of Diagnostic Accuracy Studies Tool' (QUADAS-2). True positives, false positives, true negatives, and false negatives were subtracted/calculated from the articles. The principal summary measures used to assess diagnostic accuracy were sensitivity, specificity, andarea under the receiver operating curve (AUC). Data was pooled according to analysis territory, reference standard and perfusion parameter. Twenty-two articles were eligible based on the predefined study eligibility criteria. The pooled diagnostic accuracy for segment-, territory- and patient-based analyses showed good diagnostic performance with sensitivity of 0.88, 0.82, and 0.83, specificity of 0.72, 0.83, and 0.76 and AUC of 0.90, 0.84, and 0.87, respectively. In per territory

  4. Regional cortical hyper perfusion on perfusion CT during postical motor deficit: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Hye Jin [Dept. of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2013-08-15

    Postictal neurologic deficit is a well-known complication mimicking the manifestation of a stroke. We present a case of a patient with clinical evidence of Todd's paralysis correlating with reversible postictal parenchymal changes on perfusion CT and magnetic resonance (MR) imaging. In this case, perfusion CT and MR imaging were helpful in the differential diagnosis of stroke-mimicking conditions.

  5. The Groningen hypothermic liver perfusion pump : Functional evaluation of a new machine perfusion system

    NARCIS (Netherlands)

    van der Plaats, A.; Maathuis, M. H. J.; Hart, N. A. 't; Bellekom, A. A.; Hofker, H. S.; van der Houwen, E. B.; Verkerke, G. J.; Leuvenink, H. G. D.; Verdonck, P.; Ploeg, R. J.; Rakhorst, G.

    2006-01-01

    To improve preservation of donor livers, we have developed a portable hypothermic machine perfusion (HMP) system as an alternative for static cold storage. A prototype of the system was built and evaluated on functionality. Evaluation criteria included 24 h of adequate pressure controlled perfusion,

  6. Effects of Steroid Hormones on Sex Differences in Cerebral Perfusion.

    Directory of Open Access Journals (Sweden)

    Carmen Ghisleni

    Full Text Available Sex differences in the brain appear to play an important role in the prevalence and progression of various neuropsychiatric disorders, but to date little is known about the cerebral mechanisms underlying these differences. One widely reported finding is that women demonstrate higher cerebral perfusion than men, but the underlying cause of this difference in perfusion is not known. This study investigated the putative role of steroid hormones such as oestradiol, testosterone, and dehydroepiandrosterone sulphate (DHEAS as underlying factors influencing cerebral perfusion. We acquired arterial spin labelling perfusion images of 36 healthy adult subjects (16 men, 20 women. Analyses on average whole brain perfusion levels included a multiple regression analysis to test for the relative impact of each hormone on the global perfusion. Additionally, voxel-based analyses were performed to investigate the sex difference in regional perfusion as well as the correlations between local perfusion and serum oestradiol, testosterone, and DHEAS concentrations. Our results replicated the known sex difference in perfusion, with women showing significantly higher global and regional perfusion. For the global perfusion, DHEAS was the only significant predictor amongst the steroid hormones, showing a strong negative correlation with cerebral perfusion. The voxel-based analyses revealed modest sex-dependent correlations between local perfusion and testosterone, in addition to a strong modulatory effect of DHEAS in cortical, subcortical, and cerebellar regions. We conclude that DHEAS in particular may play an important role as an underlying factor driving the difference in cerebral perfusion between men and women.

  7. Perfusion MRI in CNS disease: current concepts

    International Nuclear Information System (INIS)

    Essig, M.; Giesel, F.; Le-Huu, M.; Stieltjes, B.; Tengg, H. von; Weber, M.-A.

    2004-01-01

    Today there are several indications for cerebral perfusion MRI. The major indications routinely used in increasing numbers of imaging centers include cerebrovascular disease, tumor imaging and recently psychiatric disorders. Perfusion MRI is based on the injection of a gadolinium chelate and the rapid acquisition of images as the bolus of contrast agent passes through the blood vessels in the brain. The contrast agent causes a signal change; this signal change over time can be analysed to measure cerebral hemodynamics. The quality of brain perfusion studies is very dependent on the contrast agent used: a robust and strong signal decrease with a compact bolus is needed. MultiHance (gadobenate dimeglumine, Gd-BOPTA) is the first of a new class of paramagnetic MR contrast agents with a weak affinity for serum proteins. Due to the interaction of Gd-BOPTA with serum albumin, MultiHance presents with significantly higher T1- and T2-relaxivities enabling a sharper bolus profile. This article reviews the indications of perfusion MRI and the performance of MultiHance in MR perfusion of different diseases. Previous studies using perfusion MRI for a variety of purposes required the use of double dose of contrast agent to achieve a sufficiently large signal drop to enable the acquisition of a clear input function and the calculation of perfusion rCBV and rCBF maps of adequate quality. Recent studies with Multi-Hance suggest that only a single dose of this agent is needed to cause a signal drop of about 30% which is sufficient to allow the calculation of high quality rCBV and rCBF maps. (orig.)

  8. 31P-NMR studies on perfused mouse liver

    International Nuclear Information System (INIS)

    McLaughlin, A.C.; Takeda, H.; Chance, B.

    1978-01-01

    From a metabolic viewpoint, the most important organ in the body is the liver. In contrast to more specialized organs such as heart and kidney which perform only one major function, the liver performs a number of major metabolic functions. Two of the most important functions are the catabolism and storage of foodstuffs (in the form of glycogen) and the control of most of the constituents of the blood (in particular, the blood glucose level). Most of these functions are localized within a single type of cell. One way that the liver is able to regulate these diverse reactions is by the control of the ATP level in the cell. Encouraged by the recent success of many groups in using 31 P-NMR to provide a continuous and non-destructive monitor of ATP levels in isolated cells, skeletal muscle, and perfused organs such as heart and kidney, 31 P-NMR was used to investigate ATP levels in perfused liver of mice

  9. A Fully Automated Penumbra Segmentation Tool

    DEFF Research Database (Denmark)

    Nagenthiraja, Kartheeban; Ribe, Lars Riisgaard; Hougaard, Kristina Dupont

    2012-01-01

    Introduction: Perfusion- and diffusion weighted MRI (PWI/DWI) is widely used to select patients who are likely to benefit from recanalization therapy. The visual identification of PWI-DWI-mismatch tissue depends strongly on the observer, prompting a need for software, which estimates potentially...... salavageable tissue, quickly and accurately. We present a fully Automated Penumbra Segmentation (APS) algorithm using PWI and DWI images. We compare automatically generated PWI-DWI mismatch mask to mask outlined manually by experts, in 168 patients. Method: The algorithm initially identifies PWI lesions......) at 600∙10-6 mm2/sec. Due to the nature of thresholding, the ADC mask overestimates the DWI lesion volume and consequently we initialized level-set algorithm on DWI image with ADC mask as prior knowledge. Combining the PWI and inverted DWI mask then yield the PWI-DWI mismatch mask. Four expert raters...

  10. [An automatic system controlled by microcontroller for carotid sinus perfusion].

    Science.gov (United States)

    Yi, X L; Wang, M Y; Fan, Z Z; He, R R

    2001-08-01

    To establish a new method for controlling automatically the carotid perfusion pressure. A cheap practical automatic perfusion unit based on AT89C2051 micro controller was designed. The unit, LDB-M perfusion pump and the carotid sinus of an animal constituted an automatic perfusion system. This system was able to provide ramp and stepwise updown perfusion pattern and has been used in the research of baroreflex. It can insure the precision and reproducibility of perfusion pressure curve, and improve the technical level in corresponding medical field.

  11. Myocardial perfusion imaging with dual energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); De Cecco, Carlo N. [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncology and Pathology, University of Rome “Sapienza”, Rome (Italy); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Spandorfer, Adam; Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States)

    2016-10-15

    Highlights: • Stress dual-energy sCTMPI offers the possibility to directly detect the presence of myocardial perfusion defects. • Stress dual-energy sCTMPI allows differentiating between reversible and fixed myocardial perfusion defects. • The combination of coronary CT angiography and dual-energy sCTMPI can improve the ability of CT to detect hemodynamically relevant coronary artery disease. - Abstract: Dual-energy CT (DECT) enables simultaneous use of two different tube voltages, thus different x-ray absorption characteristics are acquired in the same anatomic location with two different X-ray spectra. The various DECT techniques allow material decomposition and mapping of the iodine distribution within the myocardium. Static dual-energy myocardial perfusion imaging (sCTMPI) using pharmacological stress agents demonstrate myocardial ischemia by single snapshot images of myocardial iodine distribution. sCTMPI gives incremental values to coronary artery stenosis detected on coronary CT angiography (CCTA) by showing consequent reversible or fixed myocardial perfusion defects. The comprehensive acquisition of CCTA and sCTMPI offers extensive morphological and functional evaluation of coronary artery disease. Recent studies have revealed that dual-energy sCTMPI shows promising diagnostic accuracy for the detection of hemodynamically significant coronary artery disease compared to single-photon emission computed tomography, invasive coronary angiography, and cardiac MRI. The aim of this review is to present currently available DECT techniques for static myocardial perfusion imaging and recent clinical applications and ongoing investigations.

  12. Myocardial perfusion assessment by dual-energy computed tomography in patients with intermediate to high likelihood of coronary artery disease

    International Nuclear Information System (INIS)

    De Zam, M.C.; Capunay, C.; Rodriguez Granillo, G.A.; Deviggiano, A.; Campisi, R.; Munain, M. López de; Vallejos, J.; Carrascosa, P.M.

    2015-01-01

    Objectives. We sought to explore the feasibility and diagnostic performance of dual-energy computed tomography (DECT) for the evaluation of myocardial perfusion in patients with intermediate to high likelihood of coronary artery disease (CAD), and to assess the impact of beam hardening artifacts (HAE). Methods. The present prospective study involved patients with known or suspected CAD referred for myocardial perfusion imaging by single-photon emission computed tomography (SPECT). Twenty patients were included in the study protocol, and scanned using DECT imaging (n = 20). The same pharmacological stress was used for DECT and SPECT scans. Results. A total of 680 left ventricular segments were evaluated by DECT and SPECT. The contrast to noise ratio was 8.8±2.9. The diagnostic performance of DECT was very good in identifying perfusion defects [area under ROC curve (AUC) of DECT 0.90 (0.86-0.94)] compared with SPECT, and remained unaffected when including only segments affected by beam hardening artifacts (BHA) [AUC= DECT 0.90 (0.84-0.96)]. Conclusions. In this pilot investigation, myocardial perfusion assessment by DECT imaging in patients with intermediate to high likelihood of CAD was feasible and remained unaffected by the presence of BHA. (authors) [es

  13. Lung scans with significant perfusion defects limited to matching pleural effusions have a low probability of pulmonary embolism

    International Nuclear Information System (INIS)

    Datz, F.L.; Bedont, R.A.; Taylor, A.

    1985-01-01

    Patients with a pleural effusion on chest x-ray often undergo a lung scan to exclude pulmonary embolism (PE). According to other studies, when the scan shows a perfusion defect equal in size to a radiographic abnormality on chest x-ray, the scan should be classified as indeterminate or intermediate probability for PE. However, since those studies dealt primarily with alveolar infiltrates rather than pleural effusions, the authors undertook a retrospective study to determine the probability of PE in patients with pleural effusion and a matching perfusion defect. The authors reviewed 451 scans and x-rays of patients studied for suspected PE. Of those, 53 had moderate or large perfusion defects secondary to pleural effusion without other significant (>25% of a segment) effusion without other significant (>25% of a segment) defects on the scan. Final diagnosis was confirmed by pulmonary angiography (16), thoracentesis (40), venography (11), other radiographic and laboratory studies, and clinical course. Of the 53 patients, only 2 patients had venous thrombotic disease. One patient had PE on pulmonary angiography, the other patient had thrombophlebitis on venography. The remainder of the patients had effusions due to congestive heart failure (12), malignancy (12), infection (7), trauma (7), collegen vascular disease (7), sympathetic effusion (3) and unknown etiology (3). The authors conclude that lung scans with significant perfusion defects limited to matching pleural effusions on chest x-ray have a low probability for PE

  14. Standardized perfusion value of the esophageal carcinoma and its correlation with quantitative CT perfusion parameter values

    Energy Technology Data Exchange (ETDEWEB)

    Djuric-Stefanovic, A., E-mail: avstefan@eunet.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Saranovic, Dj., E-mail: crvzve4@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Sobic-Saranovic, D., E-mail: dsobic2@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia); Masulovic, D., E-mail: draganmasulovic@yahoo.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Artiko, V., E-mail: veraart@beotel.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia)

    2015-03-15

    Purpose: Standardized perfusion value (SPV) is a universal indicator of tissue perfusion, normalized to the whole-body perfusion, which was proposed to simplify, unify and allow the interchangeability among the perfusion measurements and comparison between the tumor perfusion and metabolism. The aims of our study were to assess the standardized perfusion value (SPV) of the esophageal carcinoma, and its correlation with quantitative CT perfusion measurements: blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) of the same tumor volume samples, which were obtained by deconvolution-based CT perfusion analysis. Methods: Forty CT perfusion studies of the esophageal cancer were analyzed, using the commercial deconvolution-based CT perfusion software (Perfusion 3.0, GE Healthcare). The SPV of the esophageal tumor and neighboring skeletal muscle were correlated with the corresponding mean tumor and muscle quantitative CT perfusion parameter values, using Spearman's rank correlation coefficient (r{sub S}). Results: Median SPV of the esophageal carcinoma (7.1; range: 2.8–13.4) significantly differed from the SPV of the skeletal muscle (median: 1.0; range: 0.4–2.4), (Z = −5.511, p < 0.001). The cut-off value of the SPV of 2.5 enabled discrimination of esophageal cancer from the skeletal muscle with sensitivity and specificity of 100%. SPV of the esophageal carcinoma significantly correlated with corresponding tumor BF (r{sub S} = 0.484, p = 0.002), BV (r{sub S} = 0.637, p < 0.001) and PS (r{sub S} = 0.432, p = 0.005), and SPV of the skeletal muscle significantly correlated with corresponding muscle BF (r{sub S} = 0.573, p < 0.001), BV (r{sub S} = 0.849, p < 0.001) and PS (r{sub S} = 0.761, p < 0.001). Conclusions: We presented a database of the SPV for the esophageal cancer and proved that SPV of the esophageal neoplasm significantly differs from the SPV of the skeletal muscle, which represented a sample of healthy

  15. Segmentation, advertising and prices

    NARCIS (Netherlands)

    Galeotti, Andrea; Moraga González, José

    This paper explores the implications of market segmentation on firm competitiveness. In contrast to earlier work, here market segmentation is minimal in the sense that it is based on consumer attributes that are completely unrelated to tastes. We show that when the market is comprised by two

  16. Sipunculans and segmentation

    DEFF Research Database (Denmark)

    Wanninger, Andreas; Kristof, Alen; Brinkmann, Nora

    2009-01-01

    mechanisms may act on the level of gene expression, cell proliferation, tissue differentiation and organ system formation in individual segments. Accordingly, in some polychaete annelids the first three pairs of segmental peripheral neurons arise synchronously, while the metameric commissures of the ventral...

  17. Cyclooxygenase-2-dependent bronchoconstriction in perfused rat lungs exposed to endotoxin.

    OpenAIRE

    Uhlig, S.; Nüsing, R.; von Bethmann, A.; Featherstone, R. L.; Klein, T.; Brasch, F.; Müller, K. M.; Ullrich, V.; Wendel, A.

    1996-01-01

    BACKGROUND: Lipopolysaccharides (LPS), widely used to study the mechanisms of gram-negative sepsis, increase airway resistance by constriction of terminal bronchioles. The role of the cyclooxygenase (COX) isoenzymes and their prostanoid metabolites in this process was studied. MATERIALS AND METHODS: Pulmonary resistance, the release of thromboxane (TX) and the expression of COX-2 mRNA were measured in isolated blood-free perfused rat lungs exposed to LPS. RESULTS: LPS induced the release of T...

  18. The Myocardial Perfusion Scintigraphy in Predicting Risk for Coronary Artery Disease in Patients with Anxiety and Depression Symptoms

    Directory of Open Access Journals (Sweden)

    Billur Çalışkan

    2016-06-01

    Full Text Available INTRODUCTION: An association between psychological factors and cardiovascular disease, has long been suspected. However it is not clear whether chest pain is caused by emotional distress or whether coronary spasms are caused by the onset of coronary artery disease (CAD. We aimed to predict the risk for CAD in patients referred to myocardial perfusion imaging (MPI with chest pain using depression, stress, and anxiety symptoms. METHODS: The emotional status of all patients was evaluated using the Hospital Anxiety and Depression Scale (HADS-A and HADS-D, the State and Trait Anxiety Inventory (STAI-1 and STAI-2, the Perceived Stress Scale (PSS, and the Anxiety Sensitivity Index-3 (ASI. Myocardial perfusion was measured using a 17-segment model and 5-point scoring system (0: normal perfusion; 4: no perfusion. RESULTS: MPI revealed reversible perfusion defects in 24 of 141 patients and no perfusion defects in 117 patients. The STAI-2 and HADS-A and HADS-D scores were significantly higher in patients with myocardial ischemia than in those without (STAI-2: 50.8 ± 7.5 vs. 46.3 ± 7.1, respectively; p = 0.008; HADS-A: 9.5 ± 3.9 vs. 7.8 ± 3.4, respectively; p = 0.033; HADS-D: 8.7 ± 3.0 vs. 7.3 ± 3.0, respectively; p = 0.05. Unadjusted correlation analysis showed that there was statistically significant correlation between reversible perfusion defects and anxiety scores (r=0.186, p= 0.029. DISCUSSION AND CONCLUSION: The patients with symptoms of depression and high-trait anxiety may be at higher risk of myocardial ischemia than patients without such symptoms. Thus, the emotional status of patients should be taken into consideration during clinical evaluation for CAD.

  19. The myocardial perfusion imaging of bone marrow mesenchymal stem cell transplantation treated acute myocardial infarction in pig

    International Nuclear Information System (INIS)

    He Miao; Hou Xiancun; Li Yaomei; Zhou Peng; Qi Chunmei; Wu Weihuan; Li Li

    2006-01-01

    Objective: To evaluate the clinical value of bone marrow mesenchymal stem cell transplantation on acute myocardial infarction in pig with myocardial perfusion imaging. Methods: Acute myocardial infarction models were established by 21 minitype Chinese pigs and were divided into two groups. After 10 days, experimental group (n=11) was transplanted with bone marrow mesenchymal stem cell at the infarct areas, and the control group (n=10) with incubation solution. Before and eight weeks after transplantation, both groups were examined by 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging and with semi-quantitative analysis. Besides, echocardiogram and immunohistochemistry were also performed. Results: There was significant difference of total myocardial perfusion abnormal segments (46 vs 26), infarct areas [(34±12)% vs (21±10)%] and myocardial ischemia score [(20.0±4.3) vs (12.1±3.6)] between two groups (P<0.05). Also, there were accordant results with echocardiogram and immunohistochemistry findings. Conclusions: Bone marrow mesenchymal stem cell transplantation may improve blood perfusion and viability of the ischemic areas: Myocardial perfusion imaging can accurately observe the survival of bone marrow mesenchymal stem cell transplanted at the infarct areas. (authors)

  20. Lung perfusion analysis with dual energy CT in patients with suspected pulmonary embolism—Influence of window settings on the diagnosis of underlying pathologies of perfusion defects

    International Nuclear Information System (INIS)

    Bauer, Ralf W.; Kerl, J. Matthias; Weber, Eva; Weisser, Philipp; Korkusuz, Huedayi; Lehnert, Thomas; Jacobi, Volkmar; Vogl, Thomas J.

    2011-01-01

    Purpose: On lung perfusion analysis with dual energy CT (DECT) in patients with suspected pulmonary embolism (PE) commonly three patterns of perfusion defects (PD) are observed: wedge-shaped, circumscribed but not wedge-shaped, and patchy. We investigated the influence of different window settings on the identification of the underlying pathologies for these types of PD. Materials and methods: 3724 segments in 196 consecutive patients who underwent pulmonary DECT angiography for clinically suspected acute PE were analyzed. Iodine distribution in the lung parenchyma was calculated from the dual energy data and displayed as color map in axial, sagittal and coronal view. Afterwards, lung and angiography window were applied separately and assessed for pulmonary embolism and pathologies of the lung parenchyma. Results: 1420 segments in 141 patients showed PD, of which 276 were wedge-shaped, 287 circumscribed and 857 patchy. Circumscribed PD were associated in 99% with interstitial or alveolar fluid collections and in 1% with located bullae. Patchy PD were associated in 65% with emphysematous or fibrotic changes, in 38% with diffuse infiltrations or interstitial fluid collections and in 0.2% with PE. The underlying pathologies for wedge-shaped PD were in 78% PE, in 3% tumors compressing pulmonary arteries, in another 3% located bullae and in further 3% infiltrations. 13% (n = 15) of the segments in this group did not show vascular or parenchymal pathologies, but in 80% (n = 10) of these cases patients had PE in another segment. Totally n = 6 of wedge-shaped PD in 5 patients remained with unclear direct cause. Conclusion: Whereas patchy and circumscribed PD are almost exclusively associated with pathologies of the lung parenchyma, wedge-shaped PD are mostly associated with PE. For a small number of wedge-shaped PD the underlying cause cannot be detected with DECT. Very small peripherally situated micro-emboli may be discussed as a reason. However, prospective trials are

  1. Dynamic perfusion patterns in temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Dupont, Patrick; Paesschen, Wim van; Zaknun, John J.; Maes, Alex; Tepmongkol, Supatporn; Locharernkul, Chaichon; Vasquez, Silvia; Carpintiero, Silvina; Bal, C.S.; Dondi, Maurizio

    2009-01-01

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  2. Dynamic perfusion patterns in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, Patrick; Paesschen, Wim van [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); Zaknun, John J. [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); University Hospital of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Maes, Alex [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); AZ Groeninge, Nuclear Medicine, Kortrijk (Belgium); Tepmongkol, Supatporn; Locharernkul, Chaichon [Chulalongkorn University, Nuclear Medicine and Neurology, Bangkok (Thailand); Vasquez, Silvia; Carpintiero, Silvina [Fleni Instituto de Investigaciones Neurologicas, Nuclear Medicine, Buenos Aires (Argentina); Bal, C.S. [All India Institute of Medical Sciences, Nuclear Medicine, New Delhi (India); Dondi, Maurizio [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); Ospedale Maggiore, Nuclear Medicine, Bologna (Italy)

    2009-05-15

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  3. Cardiac tissue engineering using perfusion bioreactor systems

    Science.gov (United States)

    Radisic, Milica; Marsano, Anna; Maidhof, Robert; Wang, Yadong; Vunjak-Novakovic, Gordana

    2009-01-01

    This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is ‘biomimetic’ in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2–4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and high-fidelity models for biological research. PMID:18388955

  4. Intestinal permeability of forskolin by in situ single pass perfusion in rats.

    Science.gov (United States)

    Liu, Zhen-Jun; Jiang, Dong-bo; Tian, Lu-Lu; Yin, Jia-Jun; Huang, Jian-Ming; Weng, Wei-Yu

    2012-05-01

    The intestinal permeability of forskolin was investigated using a single pass intestinal perfusion (SPIP) technique in rats. SPIP was performed in different intestinal segments (duodenum, jejunum, ileum, and colon) with three concentrations of forskolin (11.90, 29.75, and 59.90 µg/mL). The investigations of adsorption and stability were performed to ensure that the disappearance of forskolin from the perfusate was due to intestinal absorption. The results of the SPIP study indicated that forskolin could be absorbed in all segments of the intestine. The effective permeability (P (eff)) of forskolin was in the range of drugs with high intestinal permeability. The P (eff) was highest in the duodenum as compared to other intestinal segments. The decreases of P (eff) in the duodenum and ileum at the highest forskolin concentration suggested a saturable transport process. The addition of verapamil, a P-glycoprotein inhibitor, significantly enhanced the permeability of forskolin across the rat jejunum. The absorbed fraction of dissolved forskolin after oral administration in humans was estimated to be 100 % calculated from rat P (eff). In conclusion, dissolved forskolin can be absorbed readily in the intestine. The low aqueous solubility of forskolin might be a crucial factor for its poor oral bioavailability. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Ex Vivo Machine Perfusion in CTA with a Novel Oxygen Carrier System to Enhance Graft Preservation and Immunologic Outcomes

    Science.gov (United States)

    2015-10-01

    within 5 different segments of the VRAM grafts (e.g. skin, subcutaneous adipose tissue, muscle, microvasculature and large hilar vessels). This modified...Large vessels ( hilar structures of the VRAM graft) 5. Nerve tissue * p < 0.05 vs machine perfusion # p < 0.05 vs Baseline (BL) n=4 each...induced myelin damage Distribution Unlimited Page 27 d. axonal vacuolization e. axotomy 5. Large hilar vessels a. intraluminal thrombi b. loss of

  6. Comparative analysis of radionuclide inhalation and perfusion lung imaging with X ray pulmonary angiography for the diagnosis of pulmonary embolism

    International Nuclear Information System (INIS)

    Zhang Yanyan; Chen Man; Shao Maogang; Zhang Songlin; Mao Jieming; Guo Jingxuan

    1993-01-01

    The result of radionuclide lung imaging was compared in 18 patients of pulmonary embolism (PE) and 2 normal persons. The discovered perfusion defects correlated well with the location of angiographic obstruction. The positive angiographic and radionuclide finding was in 141 and 104 emboli arteries respectively. The sensitivity of total emboli pulmonary segments of lung imaging was 73.8%, the specificity was 82.7 and the accuracy was 79%. The techniques correlated quite well (r = 0.83, P<0.001)

  7. Optimization of perfusion studies using Atropine

    International Nuclear Information System (INIS)

    Alvarado, A.N.; Valle, V.M.; Montoya, M.J.; Eskenazi, E.S.; Montiel, M.L.; Cueto, C.C.

    2002-01-01

    The studies of myocardial perfusion require an adequate stress; exercise or pharmacological. Every day, more pharmacological studies are performed, specially in some group of patients (women, AMI, etc). There some drugs that are used for this purpose, as adenosine and dobutamine. However, their cost and the lack of availability and infrastructure in our country do not allow there routinely use. We performed dipyridamol as a pharmacological stress, however in some patients there is a doubt regarding if the pharmacological effect was adequate. Atropine is a drug that is frequently used for different purpose and it is well know its tachycardic response. We present and alternative technique, using dipyridamol-atropine as a protocol of stress perfusion study. Our goal was to correlate the standard dipyridamol -thallium perfusion study and the dipyridamol -atropine-perfusion in patients with chronic coronary disease. We evaluated 6 patients (5 males) with stable angina and chronic coronary disease. A standard dipyridamol-thallium study was performed in all of them. Dipyridamole was administered intravenously at a rate of 0.14 mg/kg/min over 6 min for a total of 0.84 mg/kg body weight. Blood pressure, heart rate, EKG and symptoms were monitored before, during and after the pharmacological infusion. Two minutes after the infusion was completed, the radiotracer was injected intravenously. In the next 6 months, without any modification of the clinical situation (symptoms and therapy) a new dipyridamol study was performed, using 1 mg of atropine after the administration of dipyridamol. There were no differences in the collateral effects and we observed and average increase of 30% in the heart rate in relation with the study using dipyridamol alone. The addition of atropine to the standard dipyridamol perfusion study is safe, cheaper and improved the detection of perfusion defects in patients with coronary artery disease

  8. Cerebral perfusion imaging in HIV positive patients

    International Nuclear Information System (INIS)

    Kundley, Kshama; Chowdhury, D.; Lele, V.R.; Lele, R.D.

    1998-01-01

    Full text: Twelve human immunodeficiency virus (HIV) positive patients were studied by SPECT cerebral perfusion imaging 1 hour post injection of 15 mCi of 99m Tc-ECD under ideal conditions with a triple head gamma camera (Prism 3000 X P LEUHR), fanbeam collimators followed by Folstein Mini Mental Status Examination (FMMSE) and AIDS dementia complex (ADC) staging on the same day. All 12 patients were male, in the age range of 23-45 y (mean 31 y). The infected status was diagnosed by ELISA (10 patients) or Western blot (5 patients). The interval between diagnosis and imaging ranged from 1 month - 35 months (mean 15.3 months). Two patients were alcoholic and 2 were smokers. None of them had CNS disorder clinically. ADC staging and FMMSE could be performed in 4 patients. Two patients were normal (stage 0) and 2 were subclinical (stage 0.5) on ADC staging. FMMSE revealed normal or near normal status (mean score 35; maximum score 36). Cerebral perfusion images were interpreted simultaneously by 3 observers blind towards history and examination using semi-quantitative and quantitative methods by consensus. It revealed multiple areas of hypoperfusion, viz. temporal (11 patients (91 %), parietal 10 patients (83%), frontal 9 patients (75%, pre and post central gyrus 7 patients (58%), occipital 6 patients (50%) cingulate gyrus and cerebellum 5 patients (41%) and thalamic in 2 patients (16%). Hyper perfusion in caudate nuclei was noted in 10 patients (83%). The study reveals presence of multiple perfusion abnormalities on cerebral perfusion imaging in HIV positive patients who have normal/near normal mental status suggesting precedence of perfusion abnormality over clinically apparent mental deficit

  9. Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

    International Nuclear Information System (INIS)

    Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae

    2005-01-01

    Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 ± 8.5%, range:3 ∼ 35%) and mild to moderate severity (-71 ± 42.7%, range:-217 ∼ -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome

  10. Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae [Donga University College of Medicine, Busan (Korea, Republic of)

    2005-02-15

    Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 {+-} 8.5%, range:3 {approx} 35%) and mild to moderate severity (-71 {+-} 42.7%, range:-217 {approx} -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome.

  11. Prognostic Usefulness of Low Ischemic Risk SPECT in non-ST Segment Elevation Acute Coronary Syndromes

    International Nuclear Information System (INIS)

    Castillo Costa, Yanina; Mauro, Victor; Perez, Roberto; Charask, Adrian; Fairman, Enrique; Gomez Santamaria, Hector; Goral, Jorge; Barrero, Carlos

    2009-01-01

    Background: Myocardial perfusion imaging tests are used for the clinical assessment of patients hospitalized with non-ST segment elevation acute coronary syndromes (NSTACS) who have favorable in-hospital outcomes with medical therapy. However, the prognostic relevance of a .low ischemic risk. (LR) single photon emission computed tomography (SPECT) in patients with NSTACS managed with a conservative approach is uncertain, as most of the information derives from patients with chronic coronary artery disease. Objectives: 1) To analyze the outcomes of patients with NSTACS and LR SPECT at discharge, 2) to compare the results of a normal SPECT with transient perfusion defects (TPDs), permanent perfusion defects (PPDs) or combined defects (CDs), and 3) to determine the additional value of SPECT to classic risk variables. Material and Methods: Patients admitted to the CCU with a NSTACS were included. Follow-up was continued during 12 months. Definitions: Clinical risk based on TIMI risk score. LR SPECT (under exercise or pharmacological stress): TPDs ≤ 3/17 segments, PPDs ≤ 3/17 segments, CPDs: TPDs + PPDs and normal: absence of defects. Clinical events (CEs): death/infarction or rehospitalization due to angina. Results: A total of 137 patients were included (median age 59 years, 60% were men). A low TIMI risk score was present in 54% of patients and 46% presented a moderate risk. CE: 5.8%. The incidence of clinical events related to perfusion defects was as follows: normal: 2.1%, TPD: 4.5%, PPD: 5.9% and CPD: 25% (p [es

  12. The speech signal segmentation algorithm using pitch synchronous analysis

    Directory of Open Access Journals (Sweden)

    Amirgaliyev Yedilkhan

    2017-03-01

    Full Text Available Parameterization of the speech signal using the algorithms of analysis synchronized with the pitch frequency is discussed. Speech parameterization is performed by the average number of zero transitions function and the signal energy function. Parameterization results are used to segment the speech signal and to isolate the segments with stable spectral characteristics. Segmentation results can be used to generate a digital voice pattern of a person or be applied in the automatic speech recognition. Stages needed for continuous speech segmentation are described.

  13. Deficit in figure-ground segmentation following closed head injury.

    Science.gov (United States)

    Baylis, G C; Baylis, L L

    1997-08-01

    Patient CB showed a severe impairment in figure-ground segmentation following a closed head injury. Unlike normal subjects, CB was unable to parse smaller and brighter parts of stimuli as figure. Moreover, she did not show the normal effect that symmetrical regions are seen as figure, although she was able to make overt judgments of symmetry. Since she was able to attend normally to isolated objects, CB demonstrates a dissociation between figure ground segmentation and subsequent processes of attention. Despite her severe impairment in figure-ground segmentation, CB showed normal 'parallel' single feature visual search. This suggests that figure-ground segmentation is dissociable from 'preattentive' processes such as visual search.

  14. Meta-Analysis of Stress Myocardial Perfusion Imaging

    Science.gov (United States)

    2017-06-06

    Coronary Disease; Echocardiography; Fractional Flow Reserve, Myocardial; Hemodynamics; Humans; Magnetic Resonance Imaging; Myocardial Perfusion Imaging; Perfusion; Predictive Value of Tests; Single Photon Emission Computed Tomography; Positron Emission Tomography; Multidetector Computed Tomography; Echocardiography, Stress; Coronary Angiography

  15. ECG-manifest and ECG-silent dipyridamole technetium-99m sestamibi SPET perfusion defects in patients with ischaemic heart disease

    International Nuclear Information System (INIS)

    Galli, M.; Marcassa, C.; Bosimini, E.; Zoccarato, O.; Comazzi, F.; Giannuzzi, P.

    1997-01-01

    To investigate the relationship between ECG changes and perfusion abnormalities, body surface maps were recorded during dipyridamole infusion in 55 subjects (11 normals and 44 patients with ischaemic heart disease) undergoing dipyridamole technetium-99m sestamibi single-photon emission tomography (SPET). All had a normal resting ECG. The extent and severity of the sestamibi defect were quantified. New negative areas in the isointegral maps and rest-dipyridamole map differences >2 SD from normal limits were considered abnormal. After dipyridamole in normals, neither perfusion defects nor ≥1 mm ST segment depression on 12-lead ECG nor new negative areas in isointegral maps occurred. In patients, dipyridamole induced new perfusion defects in 35 (80%) but ST segment depression in only 18 (41%, P<0.001). Of the 35 patients with perfusion defects, 17 (49%, group 1) showed ST segment depression, while the other 18 (51%, group 2) did not. Abnormal body surface maps were found in 100% of group 1 and 88% of group 2 patients (NS). In group 1, the provoked hypoperfusion was of greater extent (P=0.007) and severity (P=0.01) and the onset of map abnormalities was significantly earlier (P<0.001) than in group 2; time to map abnormalities was also significantly shorter than time to ST segment depression (P=0.01). In the 35 patients with complete scintigraphic, body map and angiographic data, the severity of reversible perfusion defect proved to be the strongest correlate of ST segment depression upon logistic regression analysis. Thus, sestamibi SPET abnormalities after dipyridamole are almost always associated with electrical changes on body surface maps, suggesting myocardial ischaemia as their cause. The much less common 12-lead ECG changes are slower to appear and reflect a more severe hypoperfusion. (orig./MG). With 5 figs., 4 tabs

  16. Incremental value of myocardial perfusion over coronary angiography by spectral computed tomography in patients with intermediate to high likelihood of coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Carrascosa, Patricia M., E-mail: investigacion@diagnosticomaipu.com.ar; Deviggiano, Alejandro; Capunay, Carlos; Campisi, Roxana; López Munain, Marina de; Vallejos, Javier; Tajer, Carlos; Rodriguez-Granillo, Gaston A.

    2015-04-15

    Highlights: •We evaluated myocardial perfusion by dual energy computed tomography (DECT). •We included patients with intermediate to high likelihood of coronary artery disease. •Stress myocardial perfusion by DECT had a reliable accuracy for the detection of ischemia. •Stress myocardial perfusion with DECT showed an incremental value over anatomical evaluation. •DECT imaging was associated to a significant reduction in radiation dose compared to SPECT. -- Abstract: Purpose: We sought to explore the diagnostic performance of dual energy computed tomography (DECT) for the evaluation of myocardial perfusion in patients with intermediate to high likelihood of coronary artery disease (CAD). Materials and methods: Consecutive patients with known or suspected CAD referred for myocardial perfusion imaging by single-photon emission computed tomography (SPECT) constituted the study population and were scanned using a DECT scanner equipped with gemstone detectors for spectral imaging, and a SPECT. The same pharmacological stress was used for both scans. Results: Twenty-five patients were prospectively included in the study protocol. The mean age was 63.4 ± 10.6 years. The total mean effective radiation dose was 7.5 ± 1.2 mSv with DECT and 8.2 ± 1.7 mSv with SPECT (p = 0.007). A total of 425 left ventricular segments were evaluated by DECT, showing a reliable accuracy for the detection of reversible perfusion defects [area under ROC curve (AUC) 0.84 (0.80–0.87)]. Furthermore, adding stress myocardial perfusion provided a significant incremental value over anatomical evaluation alone by computed tomography coronary angiography [AUC 0.70 (0.65–0.74), p = 0.003]. Conclusions: In this pilot investigation, stress myocardial perfusion by DECT demonstrated a significant incremental value over anatomical evaluation alone by CTCA for the detection of reversible perfusion defects.

  17. SU-C-201-04: Quantification of Perfusion Heterogeneity Based On Texture Analysis for Fully Automatic Detection of Ischemic Deficits From Myocardial Perfusion Imaging

    International Nuclear Information System (INIS)

    Fang, Y; Huang, H; Su, T

    2015-01-01

    Purpose: Texture-based quantification of image heterogeneity has been a popular topic for imaging studies in recent years. As previous studies mainly focus on oncological applications, we report our recent efforts of applying such techniques on cardiac perfusion imaging. A fully automated procedure has been developed to perform texture analysis for measuring the image heterogeneity. Clinical data were used to evaluate the preliminary performance of such methods. Methods: Myocardial perfusion images of Thallium-201 scans were collected from 293 patients with suspected coronary artery disease. Each subject underwent a Tl-201 scan and a percutaneous coronary intervention (PCI) within three months. The PCI Result was used as the gold standard of coronary ischemia of more than 70% stenosis. Each Tl-201 scan was spatially normalized to an image template for fully automatic segmentation of the LV. The segmented voxel intensities were then carried into the texture analysis with our open-source software Chang Gung Image Texture Analysis toolbox (CGITA). To evaluate the clinical performance of the image heterogeneity for detecting the coronary stenosis, receiver operating characteristic (ROC) analysis was used to compute the overall accuracy, sensitivity and specificity as well as the area under curve (AUC). Those indices were compared to those obtained from the commercially available semi-automatic software QPS. Results: With the fully automatic procedure to quantify heterogeneity from Tl-201 scans, we were able to achieve a good discrimination with good accuracy (74%), sensitivity (73%), specificity (77%) and AUC of 0.82. Such performance is similar to those obtained from the semi-automatic QPS software that gives a sensitivity of 71% and specificity of 77%. Conclusion: Based on fully automatic procedures of data processing, our preliminary data indicate that the image heterogeneity of myocardial perfusion imaging can provide useful information for automatic determination

  18. 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.

  19. Pancreas and cyst segmentation

    Science.gov (United States)

    Dmitriev, Konstantin; Gutenko, Ievgeniia; Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Accurate segmentation of abdominal organs from medical images is an essential part of surgical planning and computer-aided disease diagnosis. Many existing algorithms are specialized for the segmentation of healthy organs. Cystic pancreas segmentation is especially challenging due to its low contrast boundaries, variability in shape, location and the stage of the pancreatic cancer. We present a semi-automatic segmentation algorithm for pancreata with cysts. In contrast to existing automatic segmentation approaches for healthy pancreas segmentation which are amenable to atlas/statistical shape approaches, a pancreas with cysts can have even higher variability with respect to the shape of the pancreas due to the size and shape of the cyst(s). Hence, fine results are better attained with semi-automatic steerable approaches. We use a novel combination of random walker and region growing approaches to delineate the boundaries of the pancreas and cysts with respective best Dice coefficients of 85.1% and 86.7%, and respective best volumetric overlap errors of 26.0% and 23.5%. Results show that the proposed algorithm for pancreas and pancreatic cyst segmentation is accurate and stable.

  20. Validation and absolute quantification of MR perfusion compared with CT perfusion in patients with unilateral cerebral arterial stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Fang-Ying, E-mail: fychiou@hotmail.com [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); Kao, Yi-Hsuan, E-mail: yhkao@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); Teng, Michael Mu Huo, E-mail: mhteng@gmail.com [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); School of Medicine, National Yang-Ming University, Taipei City, Taiwan (China); Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan (China); Chung, Hsiao-Wen, E-mail: chung@cc.ee.ntu.edu.tw [Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Chang, Feng-Chi, E-mail: fcchang374@gmail.com [School of Medicine, National Yang-Ming University, Taipei City, Taiwan (China); Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan (China); Cho, I-Chieh, E-mail: jessie8030@yahoo.com.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); Chen, Wen-Chun, E-mail: sky7408695@hotmail.com [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China)

    2012-12-15

    Objective: The aim of the study was to assess absolute quantification of dynamic susceptibility contrast-enhanced magnetic resonance perfusion (MRP) comparing with computed tomography perfusion (CTP) in patients with unilateral stenosis. Materials and methods: We retrospectively post-processed MRP in 20 patients with unilateral occlusion or stenosis of >79% at the internal carotid artery or the middle cerebral artery (MCA). Absolute quantification of MRP was performed after applying the following techniques: cerebrospinal fluid removal, vessel removal, and automatic segmentation of brain to calculate the scaling factors to convert relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values to absolute values. For comparison between MRP and CTP, we manually deposited regions of interest in bilateral MCA territories at the level containing the body of the lateral ventricle. Results: The correlation between MRP and CTP was best for mean transit time (MTT) (r = 0.83), followed by cerebral blood flow (CBF) (r = 0.52) and cerebral blood volume (CBV) (r = 0.43). There was no significant difference between CTP and MRP for CBV, CBF, and MTT on the lesion side, the contralateral side, the lesion-contralateral differences, or the lesion-to-contralateral ratios (P > 0.05). The mean differences between MRP and CTP were as follows: CBV −0.57 mL/100 g, CBF 2.50 mL/100 g/min, and MTT −0.90 s. Conclusion: Absolute quantification of MRP is possible. Using the proposed method, measured values of MRP and CTP had acceptable linear correlation and quantitative agreement.

  1. Validation and absolute quantification of MR perfusion compared with CT perfusion in patients with unilateral cerebral arterial stenosis

    International Nuclear Information System (INIS)

    Chiu, Fang-Ying; Kao, Yi-Hsuan; Teng, Michael Mu Huo; Chung, Hsiao-Wen; Chang, Feng-Chi; Cho, I-Chieh; Chen, Wen-Chun

    2012-01-01

    Objective: The aim of the study was to assess absolute quantification of dynamic susceptibility contrast-enhanced magnetic resonance perfusion (MRP) comparing with computed tomography perfusion (CTP) in patients with unilateral stenosis. Materials and methods: We retrospectively post-processed MRP in 20 patients with unilateral occlusion or stenosis of >79% at the internal carotid artery or the middle cerebral artery (MCA). Absolute quantification of MRP was performed after applying the following techniques: cerebrospinal fluid removal, vessel removal, and automatic segmentation of brain to calculate the scaling factors to convert relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values to absolute values. For comparison between MRP and CTP, we manually deposited regions of interest in bilateral MCA territories at the level containing the body of the lateral ventricle. Results: The correlation between MRP and CTP was best for mean transit time (MTT) (r = 0.83), followed by cerebral blood flow (CBF) (r = 0.52) and cerebral blood volume (CBV) (r = 0.43). There was no significant difference between CTP and MRP for CBV, CBF, and MTT on the lesion side, the contralateral side, the lesion-contralateral differences, or the lesion-to-contralateral ratios (P > 0.05). The mean differences between MRP and CTP were as follows: CBV −0.57 mL/100 g, CBF 2.50 mL/100 g/min, and MTT −0.90 s. Conclusion: Absolute quantification of MRP is possible. Using the proposed method, measured values of MRP and CTP had acceptable linear correlation and quantitative agreement.

  2. Protective effect of active perfusion in porcine models of acute myocardial ischemia

    Science.gov (United States)

    Feng, Zanxiang; Mao, Zhifu; Dong, Shengjun; Liu, Baohui

    2016-01-01

    Mortality rates associated with off-pump coronary artery bypass (CAB) are relatively high, as the majority of patients requiring CAB are at a high risk for cardiac events. The present study aimed to establish porcine models of acute myocardial ischemia, and evaluate the protective role of shunt and active perfusion. A total of 30 pigs were randomly assigned to five groups, as follows: i) Sham (control); ii) A1 (shunt; stenosis rate, 55%); iii) A2 (shunt; stenosis rate, 75%); iv) B1 (active perfusion; stenosis rate, 55%); and v) B2 (active perfusion; stenosis rate, 75%) groups. Aortic pressure (P0), left anterior descending coronary pressure (P1), and coronary effective perfusion pressure (P1/P0) were measured. The expression levels of tumor necrosis factor-α (TNF-α), cardiac troponin (cTnI), creatine kinase-myocardial band (CK-MB), interleukin (IL)-6, IL-10, B-cell lymphoma 2 (Bcl-2), and caspase-3 were detected using enzyme-linked immunosorbent assay or western blotting. The myocardial apoptosis rate was determined using the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Ischemia models with stenosis rates of 55 and 75% were successfully constructed following suturing of the descending artery. Compared with the control, the 55 and 75% stenosis groups demonstrated significantly decreased P1/P0, increased expression levels of TNF-α, cTnI, CK-MB, IL-6, IL-10 and caspase-3, an increased rate of myocardial apoptosis, and a decreased expression level of anti-apoptotic protein, Bcl-2. At 30 min following successful establishment of the model (ST segment elevation to 1 mm), group B demonstrated significantly increased P1/P0, decreased expression levels of TNF-α, cTnI, CK-MB, IL-6, IL-10 and caspase-3, a decreased rate of myocardial apoptosis, and an increased expression level of anti-apoptotic protein, Bcl-2. Furthermore, the current study indicated that active perfusion was more efficacious in maintaining myocardial perfusion and alleviating

  3. Reduced myocardial perfusion reserve in myocardium having coronary artery aneurysm of Kawasaki disease

    International Nuclear Information System (INIS)

    Yoon, S. N.; Lee, D. S.; Choi, J. Y.; Kil, H. R.; Jeong, Z. K.; Lee, M. C.; Ko, C. S.

    1997-01-01

    Kawasaki disease is a systemic vasculitis involving the coronary arteries at early childhood and cause coronary artery aneurysms and thrombotic occlusions. These coronary artery aneurysms were usually transformed later into stenotic or obstructive lesions, however, the majority of these aneurysms, even the giant ones, are known to be associated with normal epicardial coronary flow. Flow reserve is difficult to assess in aneurysmal arteries with echo or angiography. We performed this study to question if there are abnormalities in flow reserve in myocardial tissue with normal epicardial arterial flow on angiography in patients with Kawasaki disease, dipyridamole stress and rest Tc-99m-sestamibi SPECT were performed in 37 patients (28 boys, 9 girls, mean age 6.6 years). We compared SPECT findings with coronary angiography (CAG) findings in 21 patients who did both studies after finding abnormality on echocardiaography. On CAG, aneurysms were found in 26 arteries of 16 patients, i.e., 10 left main arteries, 6 left anterior descending arteries (LAD), 2 left circumflex arteries (LCX), and 8 right coronary arteries (RCA). Localized and segmental stenotic lesions were found in 11 arteries in 9 patients (LAD: 4, LCX: 1, RCA: 6). Eight of the 10 patients with aneurysms had no obvious stenosis. On stress-rest SPECT, 16(43%) out of 37 patients showed normal perfusion and the other 21(57%) showed reversible or persistent decrease. Among 11 stenotic artery territories, 3(27%) showed persistent and/or reversible perfusion defects. The other 8 were normal. Among 26 aneurysmal artery territories, 12 artery territories showe perfusion decrease. Three of the 5 patients with normal CAG showed persistent and/or transient perfusion defects. Among 14 artery territories with perfusion decrease in the 16 patients, 3(21%) could be localized to vascular territory having stenosis of supplying coronary arteries, 12(86%) were related to the coronary artery aneurysms. Two were not related to

  4. Segmentation of consumer's markets and evaluation of market's segments

    OpenAIRE

    ŠVECOVÁ, Iveta

    2013-01-01

    The goal of this bachelor thesis was to explain a possibly segmentation of consumer´s markets for a chosen company, and to present a suitable goods offer, so it would be suitable to the needs of selected segments. The work is divided into theoretical and practical part. First part describes marketing, segmentation, segmentation of consumer's markets, consumer's market, market's segments a other terms. Second part describes an evaluation of questionnaire survey, discovering of market's segment...

  5. Automatic Detection of Myocardial Boundaries in MR Cardio Perfusion Images

    NARCIS (Netherlands)

    Spreeuwers, Luuk; Breeuwer, Marcel

    2001-01-01

    Cardiovascular diseases often result in reduced blood perfusion of the myocardium (MC). Recent advances in MR allow fast recordingof contrast enhanced myocardial perfusion scans. For perfusion analysis the myocardial boundaries must be traced. Currently this is done manually. In this paper a method

  6. Sphingosine-1-Phosphate Evokes Unique Segment-Specific Vasoconstriction of the Renal Microvasculature

    Science.gov (United States)

    Singletary, Sean T.; Cook, Anthony K.; Hobbs, Janet L.; Pollock, Jennifer S.; Inscho, Edward W.

    2014-01-01

    Sphingosine-1-phosphate (S1P), a bioactive sphingolipid metabolite, has been implicated in regulating vascular tone and participating in chronic and acute kidney injury. However, little is known about the role of S1P in the renal microcirculation. Here, we directly assessed the vasoresponsiveness of preglomerular and postglomerular microvascular segments to exogenous S1P using the in vitro blood-perfused juxtamedullary nephron preparation. Superfusion of S1P (0.001–10 μM) evoked concentration-dependent vasoconstriction in preglomerular microvessels, predominantly afferent arterioles. After administration of 10 μM S1P, the diameter of afferent arterioles decreased to 35%±5% of the control diameter, whereas the diameters of interlobular and arcuate arteries declined to 50%±12% and 68%±6% of the control diameter, respectively. Notably, efferent arterioles did not respond to S1P. The S1P receptor agonists FTY720 and FTY720-phosphate and the specific S1P1 receptor agonist SEW2871 each evoked modest afferent arteriolar vasoconstriction. Conversely, S1P2 receptor inhibition with JTE-013 significantly attenuated S1P-mediated afferent arteriolar vasoconstriction. Moreover, blockade of L-type voltage-dependent calcium channels with diltiazem or nifedipine attenuated S1P-mediated vasoconstriction. Intravenous injection of S1P in anesthetized rats reduced renal blood flow dose dependently. Western blotting and immunofluorescence revealed S1P1 and S1P2 receptor expression in isolated preglomerular microvessels and microvascular smooth muscle cells. These data demonstrate that S1P evokes segmentally distinct preglomerular vasoconstriction via activation of S1P1 and/or S1P2 receptors, partially via L-type voltage-dependent calcium channels. Accordingly, S1P may have a novel function in regulating afferent arteriolar resistance under physiologic conditions. PMID:24578134

  7. Myocardial perfusion scintigraphy in the detection of silent ischemia in asymptomatic diabetic patients

    Energy Technology Data Exchange (ETDEWEB)

    Oki, Glaucia Celeste Rossatto [Clinica Diagnoson and Hospital Aristides Maltez, Salvador, BA (Brazil). Servicos de Medicina Nuclear; Pavin, Elizabeth Joao; Parisi, Maria Candida R. [Universidade Estadual de Campinas (Unicamp), Campinas, SP (Brazil). Department of Internal Medicine. Service of Endocrinology; Coelho, Otavio Rizzi; Almeida, Raitany C. [Universidade Estadual de Campinas (Unicamp), Campinas, SP (Brazil). Department of Internal Medicine. Service of Cardiology; Etchebehere, Elba Cristina Sa de Camargo; Ramos, Celso Dario, E-mail: cdramos@unicamp.br [Universidade Estadual de Campinas (Unicamp), Campinas, SP (Brazil). Department of Radiology. Service of Nuclear Medicine; Camargo, Edwaldo Eduardo [Hospital Sirio-Libanes, Campinas, SP (Brazil). Service of Nuclear Medicine

    2013-01-15

    Objective: This study was aimed to evaluate myocardial perfusion in asymptomatic patients with type 1 (DM1) and type 2 diabetes mellitus (DM2) without previous diagnoses of coronary artery disease (CAD) or cerebral infarction. Materials and Methods: Fifty-nine consecutive asymptomatic patients (16 DM1, 43 DM2) underwent myocardial perfusion scintigraphy with {sup 99m}Tc-sestamibi (MPS). They were evaluated for body mass index, metabolic control of DM, type of therapy, systemic arterial hypertension, dyslipidemia, nephropathy, retinopathy, peripheral neuropathy, smoking, and familial history of CAD. Results: MPS was abnormal in 15 patients (25.4%): 12 (20.3%) with perfusion abnormalities, and 3 with isolated left ventricular dysfunction. The strongest predictors for abnormal myocardial perfusion were: age 60 years and above (p = 0.017; odds ratio [OR] = 6.0), peripheral neuropathy (p = 0.028; OR = 6.1), nephropathy (p = 0.031; OR = 5.6), and stress ECG positive for ischemia (p = 0.049; OR = 4.08). Conclusion: Silent myocardial ischemia occurs in more than one in five asymptomatic diabetic patients. The strongest predictors of ischemia in this study were: patient age, peripheral neuropathy, nephropathy, retinopathy and a stress ECG positive for ischemia. (author)

  8. Myocardial perfusion scintigraphy in the detection of silent ischemia in asymptomatic diabetic patients

    International Nuclear Information System (INIS)

    Oki, Glaucia Celeste Rossatto; Pavin, Elizabeth Joao; Parisi, Maria Candida R.; Coelho, Otavio Rizzi; Almeida, Raitany C.; Etchebehere, Elba Cristina Sa de Camargo; Ramos, Celso Dario; Camargo, Edwaldo Eduardo

    2013-01-01

    Objective: This study was aimed to evaluate myocardial perfusion in asymptomatic patients with type 1 (DM1) and type 2 diabetes mellitus (DM2) without previous diagnoses of coronary artery disease (CAD) or cerebral infarction. Materials and Methods: Fifty-nine consecutive asymptomatic patients (16 DM1, 43 DM2) underwent myocardial perfusion scintigraphy with 99m Tc-sestamibi (MPS). They were evaluated for body mass index, metabolic control of DM, type of therapy, systemic arterial hypertension, dyslipidemia, nephropathy, retinopathy, peripheral neuropathy, smoking, and familial history of CAD. Results: MPS was abnormal in 15 patients (25.4%): 12 (20.3%) with perfusion abnormalities, and 3 with isolated left ventricular dysfunction. The strongest predictors for abnormal myocardial perfusion were: age 60 years and above (p = 0.017; odds ratio [OR] = 6.0), peripheral neuropathy (p = 0.028; OR = 6.1), nephropathy (p = 0.031; OR = 5.6), and stress ECG positive for ischemia (p = 0.049; OR = 4.08). Conclusion: Silent myocardial ischemia occurs in more than one in five asymptomatic diabetic patients. The strongest predictors of ischemia in this study were: patient age, peripheral neuropathy, nephropathy, retinopathy and a stress ECG positive for ischemia. (author)

  9. Diagnostic value of myocardial perfusion SPECT in the prediction of restenosis after coronary artery bypass graft surgery

    International Nuclear Information System (INIS)

    Paeng, J. C.; Lee, D. S.; Kang, W. J.; Kim, K. B.; Chung, J. K.; Lee, M. C.

    2002-01-01

    Myocardial SPECT has been reported to be sensitive in the detection of restenosis after revascularization. However, the diagnostic value is not well established in bypass graft surgery (CABG), due to significant influences of characteristics of graft vessels and the time interval between CABG and the SPECT. In this study, we evaluated the diagnostic value of myocardial SPECT for the restenosis after CABG. A total of 160 patients with coronary artery disease (M:F=118:42, 60±8 yr) who had undergone CABG were included. Rest T1-201/ dipyridamole stress Tc-99m-MIBI SPECT was performed 3 months (103±16 days) after CABG. Segmental perfusion was quantified using a 20-segment model, and segments of reversible perfusion defect (REV) were defined. Follow-up coronary angiography was performed 1 year (397±104 days) after CABG. The segments of REV were compared between arterial and venous graft groups. And the diagnostic power of 3-month SPECT was evaluated for the prediction of restenosis. On the 3-month SPECT, 620 segments showed REV. The segments of REV were 37% of artery-grafted segments and 36% of vein-grafted segments (p=n.s.). On 1-year coronary angiography, 113 graft vessels (28%) showed restenosis. The overall sensitivity and specificity of REV on 3-month SPECT for the prediction of restenosis were 46% and 67%, respectively, but 52% and 68%, in artery-graft group. REV detected on 3-month SPECT has a predictive value, especially, high specificity for the prediction of restenosis after CABG, which was more definite in artery-graft group

  10. Low-dose dobutamine stress gated SPET for identification of viable myocardium: comparison with stress-rest perfusion SPET and PET

    International Nuclear Information System (INIS)

    Yoshinaga, Keiichiro; Tamaki, Nagara; Katoh, Chietsugu; Kuge, Yuji; Noriyasu, Kazuyuki; Yamada, Satoshi; Ito, Yoshinori; Kohya, Tetsuro; Kitabatake, Akira; Kawai, Yuko

    2002-01-01

    The detection of viable myocardium is important for the prediction of functional recovery after revascularisation. However, a fixed perfusion defect often includes viable myocardium, and perfusion imaging then underestimates myocardial viability. We previously reported that low-dose dobutamine stress gated single-photon emission tomography (SPET) provides similar findings to dobutamine stress echocardiography in the assessment of myocardial viability. The present study investigated whether low-dose dobutamine stress gated SPET is of additional value as compared with stress-rest technetium-99m tetrofosmin SPET for the detection of myocardial viability. Standard stress-rest perfusion SPET, low-dose dobutamine stress gated SPET and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) were studied in 23 patients (mean age 67±7.6 years) with previous myocardial infarction. Twenty-one of them were successfully studied with each technique. FDG PET viability (FDG uptake ≥50%) was employed as the gold standard. One-day stress-rest 99m Tc-tetrofosmin myocardial SPET was performed. After the resting study, gated SPET was acquired following infusion of 7.5 μg kg -1 min -1 of dobutamine. Left ventricular wall motion in 16 segments was assessed by cine mode display using a four-point scale. Myocardial viability was considered present when there was improvement by one point. Of a total of 336 segments analysed, 53 had persistent defects on stress-rest perfusion SPET. FDG viability was seen in 16 of 17 dobutamine-responsive segments, but in only 11 of 36 dobutamine non-responsive segments (P<0.01). Thus, in the segments with persistent defects, viability findings on low-dose dobutamine stress gated SPET were concordant with those on FDG PET in 77% of segments (kappa value =0.55). For the detection of FDG-viable myocardium, the combination of stress-rest perfusion SPET and low-dose dobutamine stress gated SPET achieved a better sensitivity than stress

  11. Directly measuring spinal cord blood flow and spinal cord perfusion pressure via the collateral network: correlations with changes in systemic blood pressure.

    Science.gov (United States)

    Kise, Yuya; Kuniyoshi, Yukio; Inafuku, Hitoshi; Nagano, Takaaki; Hirayasu, Tsuneo; Yamashiro, Satoshi

    2015-01-01

    During thoracoabdominal surgery in which segmental arteries are sacrificed over a large area, blood supply routes from collateral networks have received attention as a means of avoiding spinal cord injury. The aim of this study was to investigate spinal cord blood supply through a collateral network by directly measuring spinal cord blood flow and spinal cord perfusion pressure experimentally. In beagle dogs (n = 8), the thoracoabdominal aorta and segmental arteries L1-L7 were exposed, and a temporary bypass was created for distal perfusion. Next, a laser blood flow meter was placed on the spinal dura mater in the L5 region to measure the spinal cord blood flow. The following were measured simultaneously when the direct blood supply from segmental arteries L2-L7 to the spinal cord was stopped: mean systemic blood pressure, spinal cord perfusion pressure (blood pressure within the aortic clamp site), and spinal cord blood flow supplied via the collateral network. These variables were then investigated for evidence of correlations. Positive correlations were observed between mean systemic blood pressure and spinal cord blood flow during interruption of segmental artery flow both with (r = 0.844, P flow with and without distal perfusion (r = 0.803, P network from outside the interrupted segmental arteries, and high systemic blood pressure (∼1.33-fold higher) was needed to obtain the preclamping spinal cord blood flow, whereas 1.68-fold higher systemic blood pressure was needed when distal perfusion was halted. Spinal cord blood flow is positively correlated with mean systemic blood pressure and spinal cord perfusion pressure under spinal cord ischemia caused by clamping a wide range of segmental arteries. In open and endovascular thoracic and thoracoabdominal surgery, elevating mean systemic blood pressure is a simple and effective means of increasing spinal cord blood flow, and measuring spinal cord perfusion pressure seems to be useful for monitoring

  12. 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

  13. 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...

  14. 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.

  15. Acid perfusion test in gastroesophageal reflux disease

    Energy Technology Data Exchange (ETDEWEB)

    Kaul, B.; Petersen, H.; Grette, K.; Myrvold, H.E.

    1986-01-01

    An acid perfusion test, isotope scanning, endoscopy, and esophageal biopsy were performed in 101 patients with symptoms strongly suggestive of gastroesophageal reflux (GER) disease. A positive acid perfusion test within 30 min (APT) and within 5 min (TAPT) was found in 70.2% and 37.6% of the patients, respectively. A positive APT was found significantly more often in patients with than without endoscopic esophagitis, whereas a positive TAPT was found significantly more often in patients with severe symptoms than in patients with moderate symptoms, and in a significantly higher proportion of patients with than without GER by scintigraphy. Neither the APT nor the TAPT showed any dependency on the presence of histologic esophagitis. Most (97%) patients with a negative acid perfusion test, in addition to typical symptoms, also presented with scintigraphic, endoscopic, or histologic evidence of GER disease. Although it shows that the acid perfusion test, particularly when early positive, may serve as a weak predictor of the severity of GER disease, the present study gives little support to the test's clinical usefulness.

  16. Nuclear cardiology: Myocardial perfusion and function

    International Nuclear Information System (INIS)

    Seldin, D.W.

    1991-01-01

    Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than originally thought, and various strategies have been proposed to clarify the meaning of persistent defects. Pharmacologic intervention with dipyridamole and adenosine has become available as an alternative to exercise, and comparisons with exercise imaging and catheterization results have been described. Thallium itself is no longer the sole single-photon perfusion radiopharmaceutical; two new technetium agents are now widely available. In addition to perfusion studies, advances in the study of ventricular function have been made, including reports of studies performed in conjunction with technetium perfusion studies, new insights into cardiac physiology, and the prognostic and case-management information that function studies provide. Finally, work has continued with monoclonal antibodies for the identification of areas of myocyte necrosis. 41 references

  17. Perfusion Quantification Using Gaussian Process Deconvolution

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke; Have, Anna Szynkowiak; Rasmussen, Carl Edward

    2002-01-01

    The quantification of perfusion using dynamic susceptibility contrast MRI (DSC-MRI) requires deconvolution to obtain the residual impulse response function (IRF). In this work, a method using the Gaussian process for deconvolution (GPD) is proposed. The fact that the IRF is smooth is incorporated...

  18. Segmental tuberculosis verrucosa cutis

    Directory of Open Access Journals (Sweden)

    Hanumanthappa H

    1994-01-01

    Full Text Available A case of segmental Tuberculosis Verrucosa Cutis is reported in 10 year old boy. The condition was resembling the ascending lymphangitic type of sporotrichosis. The lesions cleared on treatment with INH 150 mg daily for 6 months.

  19. Chromosome condensation and segmentation

    International Nuclear Information System (INIS)

    Viegas-Pequignot, E.M.

    1981-01-01

    Some aspects of chromosome condensation in mammalians -humans especially- were studied by means of cytogenetic techniques of chromosome banding. Two further approaches were adopted: a study of normal condensation as early as prophase, and an analysis of chromosome segmentation induced by physical (temperature and γ-rays) or chemical agents (base analogues, antibiotics, ...) in order to show out the factors liable to affect condensation. Here 'segmentation' means an abnormal chromosome condensation appearing systematically and being reproducible. The study of normal condensation was made possible by the development of a technique based on cell synchronization by thymidine and giving prophasic and prometaphasic cells. Besides, the possibility of inducing R-banding segmentations on these cells by BrdU (5-bromodeoxyuridine) allowed a much finer analysis of karyotypes. Another technique was developed using 5-ACR (5-azacytidine), it allowed to induce a segmentation similar to the one obtained using BrdU and identify heterochromatic areas rich in G-C bases pairs [fr

  20. International EUREKA: Initialization Segment

    International Nuclear Information System (INIS)

    1982-02-01

    The Initialization Segment creates the starting description of the uranium market. The starting description includes the international boundaries of trade, the geologic provinces, resources, reserves, production, uranium demand forecasts, and existing market transactions. The Initialization Segment is designed to accept information of various degrees of detail, depending on what is known about each region. It must transform this information into a specific data structure required by the Market Segment of the model, filling in gaps in the information through a predetermined sequence of defaults and built in assumptions. A principal function of the Initialization Segment is to create diagnostic messages indicating any inconsistencies in data and explaining which assumptions were used to organize the data base. This permits the user to manipulate the data base until such time the user is satisfied that all the assumptions used are reasonable and that any inconsistencies are resolved in a satisfactory manner

  1. Volume perfusion CT imaging of cerebral vasospasm: diagnostic performance of different perfusion maps

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Afat, Saif; Nikoubashman, Omid; Mueller, Marguerite; Wiesmann, Martin; Brockmann, Carolin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Schubert, Gerrit Alexander [RWTH Aachen University, Department of Neurosurgery, Aachen (Germany); Bier, Georg [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Brockmann, Marc A. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University Hospital Mainz, Department of Neuroradiology, Mainz (Germany)

    2016-08-15

    In this study, we aimed to evaluate the diagnostic performance of different volume perfusion CT (VPCT) maps regarding the detection of cerebral vasospasm compared to angiographic findings. Forty-one datasets of 26 patients (57.5 ± 10.8 years, 18 F) with subarachnoid hemorrhage and suspected cerebral vasospasm, who underwent VPCT and angiography within 6 h, were included. Two neuroradiologists independently evaluated the presence and severity of vasospasm on perfusion maps on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting <50 %, 2 - vasospasm affecting >50 % of vascular territory). A third neuroradiologist independently assessed angiography for the presence and severity of vasospasm on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting < 50 %, 2 - vasospasm affecting > 50 % of vessel diameter). Perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to drain (TTD) were evaluated regarding diagnostic accuracy for cerebral vasospasm with angiography as reference standard. Correlation analysis of vasospasm severity on perfusion maps and angiographic images was performed. Furthermore, inter-reader agreement was assessed regarding findings on perfusion maps. Diagnostic accuracy for TTD and MTT was significantly higher than for all other perfusion maps (TTD, AUC = 0.832; MTT, AUC = 0.791; p < 0.001). TTD revealed higher sensitivity than MTT (p = 0.007). The severity of vasospasm on TTD maps showed significantly higher correlation levels with angiography than all other perfusion maps (p ≤ 0.048). Inter-reader agreement was (almost) perfect for all perfusion maps (kappa ≥ 0.927). The results of this study indicate that TTD maps have the highest sensitivity for the detection of cerebral vasospasm and highest correlation with angiography regarding the severity of vasospasm. (orig.)

  2. Detectable perfusion changes in MAG3 studies

    International Nuclear Information System (INIS)

    Shuter, B.; Bernar, A.; Roach, P.

    1998-01-01

    Full text: The use of 120 MBq 99m Tc-MAG 3 instead of 600 MBq 99m Tc-DTPA in renal imaging has degraded the images obtained during the perfusion phase. An increase of the minimum detectable change (MDC) in blood flow (BF) would also be expected. In transplant patients, renal BF is an important factor in patient management and the MDC should be small to allow early detection of reduced perfusion. We determined the mean and coefficient of variation (CoV: standard deviation/mean) of three renal perfusion indices as a function of counts in the time-activity curves (TACs). Transplant patients were given a dose of about 300 MBq of 99m Tc-MAG3 and images acquired at 8 fps for 60s. TACs made up from 8, 4, 2 or I images per second allowed calculation of renal perfusion indices as if doses of 300, 150, 75 and 38 MBq had been administered. Perfusion indices based on area under the TACs up to the arterial peak (API), the maximum slopes of the TACs (SPI) and the maximum slope of renal TAC and height of arterial TAC (BPI) were calculated by our routine renal software package. As the administered dose decreased, the CoV rose for all indices, least for BPI and most for API. BPI CoV increased from ∼10% at 300 MBq to 20% at 75 MBq, but API CoV rose from 6% to 46%. Mean BPI was stable over the dose range, but mean API showed a systematic increase of about 50% over the 300 MBq result. We conclude that at 120 MBq the MDC (expressed as 2*CoV) in BF is 30-60%, whereas at 600 MBq it may be as low as 10%, allowing earlier confident detection of a change in BF. The BPI was the preferred perfusion index as its mean value changed little and it had the least CoV at lower activities. The data also imply that relative kidney perfusion in the one individual will be much less accurate with 120 MBq of MAG 3

  3. Angular Magnetoresistance of Nanowires with Alternating Cobalt and Nickel Segments

    KAUST Repository

    Mohammed, Hanan

    2017-06-22

    Magnetization reversal in segmented Co/Ni nanowires with varying number of segments was studied using angular Magnetoresistance (MR) measurements on isolated nanowires. The MR measurements offer an insight into the pinning of domain walls within the nanowires. Angular MR measurements were performed on nanowires with two and multiple segments by varying the angle between the applied magnetic field and nanowire (−90° ≤θ≤90°). The angular MR measurements reveal that at lower values of θ the switching fields are nearly identical for the multisegmented and two-segmented nanowires, whereas at higher values of θ, a decrease in the switching field is observed in the case of two segmented nanowires. The two segmented nanowires generally exhibit a single domain wall pinning event, whereas an increased number of pinning events are characteristic of the multisegmented nanowires at higher values of θ. In-situ magnetic force microscopy substantiates reversal by domain wall nucleation and propagation in multisegmented nanowires.

  4. Angular Magnetoresistance of Nanowires with Alternating Cobalt and Nickel Segments

    KAUST Repository

    Mohammed, Hanan; Corte-Leon, H.; Ivanov, Yurii P.; Moreno, J. A.; Kazakova, O.; Kosel, Jü rgen

    2017-01-01

    Magnetization reversal in segmented Co/Ni nanowires with varying number of segments was studied using angular Magnetoresistance (MR) measurements on isolated nanowires. The MR measurements offer an insight into the pinning of domain walls within the nanowires. Angular MR measurements were performed on nanowires with two and multiple segments by varying the angle between the applied magnetic field and nanowire (−90° ≤θ≤90°). The angular MR measurements reveal that at lower values of θ the switching fields are nearly identical for the multisegmented and two-segmented nanowires, whereas at higher values of θ, a decrease in the switching field is observed in the case of two segmented nanowires. The two segmented nanowires generally exhibit a single domain wall pinning event, whereas an increased number of pinning events are characteristic of the multisegmented nanowires at higher values of θ. In-situ magnetic force microscopy substantiates reversal by domain wall nucleation and propagation in multisegmented nanowires.

  5. Perfusion vector - a new method to quantify myocardial perfusion scintigraphy images: a simulation study with validation in patients

    DEFF Research Database (Denmark)

    Minarik, David; Senneby, Martin; Wollmer, Per

    2015-01-01

    Background The interpretation of myocardial perfusion scintigraphy (MPS) largely relies on visual assessment by the physician of the localization and extent of a perfusion defect. The aim of this study was to introduce the concept of the perfusion vector as a new objective quantitative method...

  6. Fluence map segmentation

    International Nuclear Information System (INIS)

    Rosenwald, J.-C.

    2008-01-01

    The lecture addressed the following topics: 'Interpreting' the fluence map; The sequencer; Reasons for difference between desired and actual fluence map; Principle of 'Step and Shoot' segmentation; Large number of solutions for given fluence map; Optimizing 'step and shoot' segmentation; The interdigitation constraint; Main algorithms; Conclusions on segmentation algorithms (static mode); Optimizing intensity levels and monitor units; Sliding window sequencing; Synchronization to avoid the tongue-and-groove effect; Accounting for physical characteristics of MLC; Importance of corrections for leaf transmission and offset; Accounting for MLC mechanical constraints; The 'complexity' factor; Incorporating the sequencing into optimization algorithm; Data transfer to the treatment machine; Interface between R and V and accelerator; and Conclusions on fluence map segmentation (Segmentation is part of the overall inverse planning procedure; 'Step and Shoot' and 'Dynamic' options are available for most TPS (depending on accelerator model; The segmentation phase tends to come into the optimization loop; The physical characteristics of the MLC have a large influence on final dose distribution; The IMRT plans (MU and relative dose distribution) must be carefully validated). (P.A.)

  7. Gamifying Video Object Segmentation.

    Science.gov (United States)

    Spampinato, Concetto; Palazzo, Simone; Giordano, Daniela

    2017-10-01

    Video object segmentation can be considered as one of the most challenging computer vision problems. Indeed, so far, no existing solution is able to effectively deal with the peculiarities of real-world videos, especially in cases of articulated motion and object occlusions; limitations that appear more evident when we compare the performance of automated methods with the human one. However, manually segmenting objects in videos is largely impractical as it requires a lot of time and concentration. To address this problem, in this paper we propose an interactive video object segmentation method, which exploits, on one hand, the capability of humans to identify correctly objects in visual scenes, and on the other hand, the collective human brainpower to solve challenging and large-scale tasks. In particular, our method relies on a game with a purpose to collect human inputs on object locations, followed by an accurate segmentation phase achieved by optimizing an energy function encoding spatial and temporal constraints between object regions as well as human-provided location priors. Performance analysis carried out on complex video benchmarks, and exploiting data provided by over 60 users, demonstrated that our method shows a better trade-off between annotation times and segmentation accuracy than interactive video annotation and automated video object segmentation approaches.

  8. Strategic market segmentation

    Directory of Open Access Journals (Sweden)

    Maričić Branko R.

    2015-01-01

    Full Text Available Strategic planning of marketing activities is the basis of business success in modern business environment. Customers are not homogenous in their preferences and expectations. Formulating an adequate marketing strategy, focused on realization of company's strategic objectives, requires segmented approach to the market that appreciates differences in expectations and preferences of customers. One of significant activities in strategic planning of marketing activities is market segmentation. Strategic planning imposes a need to plan marketing activities according to strategically important segments on the long term basis. At the same time, there is a need to revise and adapt marketing activities on the short term basis. There are number of criteria based on which market segmentation is performed. The paper will consider effectiveness and efficiency of different market segmentation criteria based on empirical research of customer expectations and preferences. The analysis will include traditional criteria and criteria based on behavioral model. The research implications will be analyzed from the perspective of selection of the most adequate market segmentation criteria in strategic planning of marketing activities.

  9. Myocardial perfusion imaging by digital subtraction angiography

    International Nuclear Information System (INIS)

    Kadowaki, Hiroyuki; Ishikawa, Kinji; Ogai, Toshihiro; Katori, Ryo

    1986-01-01

    Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; 1) at the R wave of the electrocardiogram, 2) 100 msec before the R wave, and 3) 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the