Science.gov

Sample records for reversed arterial perfusion

  1. Twin Reversed Arterial Perfusion: To Treat or Not?

    PubMed Central

    Verma, Meesha; Goel, Poonam; Punia, RPS

    2017-01-01

    Acardiac twinning or Twin Reverse Arterial Perfusion (TRAP)-sequence is a rare complication of monochorionic twin pregnancy. Whether to start elective or therapeutic treatment in TRAP-sequence is still controversial. In the present case, acardiac twin was not diagnosed till her delivery at 39 weeks. A healthy baby weighing 2.45 kg was delivered along with another amorphous mass (acardiac twin) of about 150 g which was attached to the placenta with a short and separate cord. As outcome of normal twin vary according to the growth of acardiac twin, frequent follow-up of the normal twin is required to look for the features of heart failure. Hence, the diagnosis of acardiac twin is essential in early pregnancy. PMID:28274006

  2. Reversal of diffuse patchy pattern in lung perfusion scan in a case of severe pulmonary arterial hypertension.

    PubMed

    Kodama, Yoshihiko; Abe, Kohtaro; Hosokawa, Kazuya; Ohtani, Kisho; Nagao, Michinobu; Hirooka, Yoshitaka; Sunagawa, Kenji

    2015-01-01

    A diffuse patchy pattern in the perfusion scan of the lung is a hallmark of severe pulmonary arterial hypertension (PAH). However, the mechanisms of this unique pattern remain uncertain. We here present the case of a 19-year-old woman with severe PAH who demonstrated reversal of the diffuse patchy pattern with improvement of pulmonary blood flow within a month after upfront triple combination therapy. Our case is a first report showing reversibility of diffuse patchy pattern by a short-term treatment in severe PAH. These findings suggest the possibility that the mechanisms underlying the diffuse patchy pattern may involve reversible vasoconstriction in addition to remodeling of small pulmonary arteries.

  3. Septal and anterior reverse mismatch of myocardial perfusion and metabolism in patients with coronary artery disease and left bundle branch block.

    PubMed

    Wang, Jian-Guang; Fang, Wei; Yang, Min-Fu; Tian, Yue-Qin; Zhang, Xiao-Li; Shen, Rui; Sun, Xiao-Xin; Guo, Feng; Wang, Dao-Yu; He, Zuo-Xiang

    2015-05-01

    The effects of left bundle branch block (LBBB) on left ventricular myocardial metabolism have not been well investigated. This study evaluated these effects in patients with coronary artery disease (CAD).Sixty-five CAD patients with complete LBBB (mean age, 61.8 ± 9.7 years) and 65 without LBBB (mean age, 59.9 ± 8.4 years) underwent single photon emission computed tomography, positron emission tomography, and contrast coronary angiography. The relationship between myocardial perfusion and metabolism and reverse mismatch score, and that between QRS length and reverse mismatch score and wall motion score were evaluated.The incidence of left ventricular septum and anterior wall reverse mismatching between the two groups was significantly different (P < 0.001 and P = 0.002, respectively). The incidences of normal myocardial perfusion and metabolism in the left ventricular lateral and inferior walls were also significantly different between the two groups (P < 0.001 and P < 0.001, respectively). The incidence of septal reverse mismatching in patients with mild to moderate perfusion was significantly higher among those with LBBB than among those without LBBB (P < 0.001). In CAD patients with LBBB, septal reverse mismatching was significantly more common among those with mild to moderate perfusion than among those with severe perfusion defects (P = 0.002). The correlation between the septal reverse mismatch score and QRS length was significant (P = 0.026).In patients with CAD and LBBB, septal and anterior reverse mismatching of myocardial perfusion and metabolism was frequently present; the septal reverse mismatch score negatively correlated with the QRS interval.

  4. Diagnosis of twin-to-twin transfusion syndrome, selective fetal growth restriction, twin anaemia-polycythaemia sequence, and twin reversed arterial perfusion sequence.

    PubMed

    Sueters, Marieke; Oepkes, Dick

    2014-02-01

    Monochorionic twin pregnancies are well known to be at risk for a variety of severe complications, a true challenge for the maternal-fetal medicine specialist. With current standards of care, monochorionicity should be established in the first trimester. Subsequently, frequent monitoring using the appropriate diagnostic tools, and in-depth knowledge about the pathophysiology of all possible clinical presentations of monochorionic twin abnormalities, should lead to timely recognition, and appropriate management. Virtually all unique diseases found in monochorionic twins are directly related to placental angio-architecture. This, however, cannot be established reliably before birth. The clinician needs to be aware of the definitions and symptoms of twin-to twin transfusion syndrome, selective fetal growth restriction, twin anaemia-polycythaemia sequence, and twin reversed arterial perfusion sequence, to be able to recognise each disease and take the required action. In this chapter, we address current standards on correct and timely diagnoses of severe complications of monochorionic twin pregnancies.

  5. Reversal of focal "misery-perfusion syndrome" by extra-intracranial arterial bypass in hemodynamic cerebral ischemia. A case study with 15O positron emission tomography.

    PubMed

    Baron, J C; Bousser, M G; Rey, A; Guillard, A; Comar, D; Castaigne, P

    1981-01-01

    Tomographic images of cerebral blood flow (CBF) and oxygen extraction fraction (OEF) using the 15O continuous inhalation technique, and positron emission tomography, were obtained from a patient with cerebral ischemia distal to an occluded left internal carotid artery. There was a focal mismatch between CBF and oxygen metabolism in the brain supplied by the middle cerebral artery where CBF was decreased and OEF increased ("misery-perfusion syndrome" as opposed to "luxury-perfusion syndrome"). These abnormalities were most marked in the parieto-occipital watershed area. After left superficial temporal to middle cerebral artery anastomosis, the clinical attacks ceased and a repeat study did not demonstrate the previous CBF and OEF abnormalities. This suggests that this pattern of abnormalities indicates potential viable tissue. The concept of "misery-perfusion" may be of some importance in the pathophysiological mechanisms of hemodynamic cerebral ischemia and serve as a rational basis for revascularization procedures.

  6. Arterial Perfusion Imaging-Defined Subvolume of Intrahepatic Cancer

    PubMed Central

    Wang, Hesheng; Farjam, Reza; Feng, Mary; Hussain, Hero; Ten Haken, Randall K.; Lawrence, Theodore S.; Cao, Yue

    2014-01-01

    Purpose To assess whether an increase in a subvolume of intrahepatic tumor with elevated arterial perfusion during radiation therapy (RT) predicts tumor progression post RT. Methods and Materials Twenty patients with unresectable intrahepatic cancers undergoing RT were enrolled in a prospective IRB-approved study. Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) were performed prior to RT (pre-RT), after delivering ~60% of the planned dose (mid-RT) and one month after completion of RT to quantify hepatic arterial perfusion. The arterial perfusions of the tumors at pre-RT were clustered into low-normal and elevated perfusion by a fuzzy clustering-based method, and the tumor subvolumes with elevated arterial perfusion were extracted from the hepatic arterial perfusion images. The percentage changes in the tumor subvolumes and means of arterial perfusion over the tumors from pre-RT to mid-RT were evaluated for predicting tumor progression post-RT. Results Of the 24 tumors, 6 tumors in 5 patients progressed 5–21 months after RT completion. Neither tumor volumes nor means of tumor arterial perfusion at pre-RT were predictive of treatment outcome. The mean arterial perfusion over the tumors increased significantly at mid-RT in progressive tumors comparing to the responsive ones (p=0.006). From pre-RT to mid-RT, the responsive tumors had a decrease in the tumor subvolumes with elevated arterial perfusion (median: −14%, range: −75% – 65%), while the progressing tumors had an increase of the subvolumes (median: 57%, range: −7% – 165%) (p=0.003). Receiver operating characteristic (ROC) analysis of the percentage change in the subvolume for predicting tumor progression post-RT had an area under the curve (AUC) of 0.90. Conclusion The increase in the subvolume of the intrahepatic tumor with elevated arterial perfusion during RT has the potential to be a predictor for tumor progression post-RT. The tumor subvolume could be a radiation boost candidate

  7. Real-time vascular mechanosensation through ex vivo artery perfusion

    PubMed Central

    2014-01-01

    Background Cell-based perfusion studies have provided great insight into fluid-sensing mechanisms, such as primary cilia in the renal and vascular systems. However, the intrinsic limitations of in vitro cell culture, such as the inability to reflect cellular organization within tissues, has distanced observed paradigms from possible clinical developments. Here we describe a protocol that applies ex vivo artery perfusion and calcium imaging to observe real-time cellular responses to fluid-shear stress. Results Through our ex vivo artery perfusion method, we were able to simulate physiological flow and initiate distinct fluid shear stress mechanosensory responses, as well as induced acetylcholine responses in mouse aortic tissue. The observed calcium profiles confirm results found through previous in vitro cell culture experiments. The overall procedure, including dissection, sample preparation and perfusion, takes around 3 hours to complete. Conclusion Through our unique method, we are able to induce laminar flow within intact mouse aortic tissue and illicit subsequent cellular responses. This method of ex vivo artery perfusion provides the opportunity to bridge the novel findings of in vitro studies with subsequent physiological models of fluid-shear stress mechanosensation in vascular tissues. PMID:24685068

  8. Numerical simulation of blood flow in femoral perfusion: comparison between side-armed femoral artery perfusion and direct femoral artery perfusion.

    PubMed

    Kitamura, Shingo; Shirota, Minori; Fukuda, Wakako; Inamura, Takao; Fukuda, Ikuo

    2016-12-01

    Computational numerical analysis was performed to elucidate the flow dynamics of femoral artery perfusion. Numerical simulation of blood flow was performed from the right femoral artery in an aortic model. An incompressible Navier-Stokes equation and continuity equation were solved using computed flow dynamics software. Three different perfusion models were analyzed: a 4.0-mm cannula (outer diameter 15 French size), a 5.2-mm cannula (18 French size) and an 8-mm prosthetic graft. The cannula was inserted parallel to the femoral artery, while the graft was anastomosed perpendicular to the femoral artery. Shear stress was highest with the 4-mm cannula (172 Pa) followed by the graft (127 Pa) and the 5.2-mm cannula (99 Pa). The cannula exit velocity was high, even when the 5.2-mm cannula was used. Although side-armed perfusion with an 8-mm graft generated a high shear stress area near the point of anastomosis, flow velocity at the external iliac artery was decreased. The jet speed decreased due to the Coanda effect caused by the recirculation behind sudden expansion of diameter, and the flow velocity maintains a constant speed after the reattachment length of the flow. This study showed that iliac artery shear stress was lower with the 5.2-mm cannula than with the 4-mm cannula when used for femoral perfusion. Side-armed graft perfusion generates a high shear stress area around the anastomotic site, but flow velocity in the iliac artery is slower in the graft model than in the 5.2-mm cannula model.

  9. Peripheral Arterial Disease Assessment Wall, Perfusion, and Spectroscopy

    PubMed Central

    Kramer, Christopher M.

    2010-01-01

    Introduction Peripheral arterial disease (PAD) is characterized by lower limb arterial obstruction due to atherosclerosis and is increasingly common. Presently used methods for diagnosis and follow-up as well as for assessment of novel therapies are limited. Materials and Methods Three distinct magnetic resonance examinations were developed. The first was high-resolution black-blood atherosclerotic plaque imaging of the superficial femoral artery using a surface coil and flow saturation. Second, first-pass contrast-enhanced dual-contrast perfusion imaging of the calf muscle was performed at peak exercise using a magnetic resonance (MR)–compatible pedal ergometer. Lastly, 31P MR spectroscopy was also performed at peak exercise to measure phosphocreatine (PCr) recovery kinetics. Results Seventeen patients (age, 63 ± 10 yrs) with mild to moderate PAD were studied with black-blood atherosclerotic plaque imaging. Mean atherosclerotic plaque volume measured was 7.27 ± 3.73 cm3. Eleven patients (age, 61 ± 11 yrs) with mild to moderate symptomatic PAD and 22 normal control subjects were studied with first-pass contrast-enhanced perfusion imaging. Perfusion index was stepwise increased from patients to normal subjects with matched workload to normal subjects at maximal exercise. For PCr recovery kinetics, 20 patients with mild to moderate PAD and 14 controls were studied. The median recovery time constant of PCr was 34.7 seconds in the controls and 91.0 seconds in the PAD patients (P < 0.0001). Conclusions Three distinct MR examinations of different aspects of peripheral arterial disease have been developed and tested and shown to differentiate patients with mild to moderate PAD from normal controls. Taken together, these tests are potential quantitative end points for clinical trials of novel therapies in PAD. PMID:18025990

  10. Effects of BRL 38227, sodium nitroprusside and verapamil on collateral perfusion following acute arterial occlusion in the rabbit isolated ear.

    PubMed Central

    Randall, M. D.; Griffith, T. M.

    1992-01-01

    1. We have used an isolated, buffer-perfused, rabbit ear model of acute arterial occlusion to investigate the effects of the nitrovasodilator sodium nitroprusside, the potassium channel activator BRL 38227 (the active (-)-enantiomer of cromakalim) and the calcium antagonist, verapamil, on collateral perfusion in the absence of pharmacological tone. 2. Verapamil was the most potent vasodilator (EC50 = 72.6 +/- 32.0 nM) of 5-hydroxytryptamine/histamine-induced tone in the rabbit isolated perfused ear. Sodium nitroprusside and BRL 38227 were less potent with respective EC50 values of 488 +/- 75 nM and 296 +/- 40 nM. Following inhibition of endothelium-derived relaxing factor (EDRF) synthesis, the potency of BRL 38227 was significantly (P less than 0.001) increased with an EC50 of 55.6 +/- 5.0 nM. 3. BRL 38227 at 500 nM and 3 microM induced substantial increases in collateral perfusion following arterial ligation in the absence of pharmacological tone compared to control. Furthermore 3 microM BRL 38227 completely reversed the attenuation of collateral perfusion which followed inhibition of EDRF synthesis with 100 microM NG-nitro-L-arginine methyl ester (L-NAME). 4. Sodium nitroprusside (500 nM and 3 microM) induced modest improvements in collateral perfusion in the early stages after arterial occlusion. 5. Verapamil did not influence collateral perfusion at either of the concentrations used (50 nM and 3 microM), even though it was a potent vasodilator. 6. The results of this study indicate that BRL 38227, and to a much lesser extent sodium nitroprusside, selectively improve collateral perfusion following arterial occlusion, even in the presence of effects of EDRF on acute collateralization, while verapamil has no effect.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 PMID:1393264

  11. Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging

    PubMed Central

    Martin, Alastair J.; Alexander, Matthew D.; McCoy, David B.; Cooke, Daniel L.; Lillaney, Prasheel; Moftakhar, Parham; Amans, Matthew R.; Settecase, Fabio; Nicholson, Andrew; Dowd, Christopher F.; Halbach, Van V.; Higashida, Randall T.; McDermott, Michael W.; Saloner, David; Hetts, Steven W.

    2016-01-01

    Background and Purpose To evaluate the ability of IA MR perfusion to characterize meningioma blood supply. Methods Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA) and intravenous (IV) T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA) dural, internal carotid artery (ICA) dural, or pial. MR perfusion data regions of interest (ROIs) were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT). Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling. Results 18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11), ICA dural (n = 4), or pial (n = 3). FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion. PMID:27802268

  12. AUGMENTATION OF LIMB PERFUSION AND REVERSAL OF TISSUE ISCHEMIA PRODUCED BY ULTRASOUND-MEDIATED MICROBUBBLE CAVITATION

    PubMed Central

    Belcik, J. Todd; Mott, Brian H.; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J.; Ammi, Azzdine; Linden, Joel M.; Lindner, Jonathan R.

    2015-01-01

    Background Ultrasound can increase tissue blood flow in part through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation, and sought to characterize the biologic mediators. Methods and Results Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in non-ischemic mice after unilateral 10 min exposure to intermittent ultrasound alone (mechanical index [MI] 0.6 or 1.3) or ultrasound with lipid microbubbles (2×108 I.V.). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (p<0.05) in muscle perfusion regardless of ultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3-fold and 10-fold higher than control for MI 0.6 and 1.3, respectively; p<0.05), as was femoral artery dilation. Inhibition of endothelial nitric oxide synthase (eNOS) attenuated flow augmentation produced by ultrasound and microbubbles by 70% (p<0.01), whereas inhibition of adenosine-A2a receptors and epoxyeicosatrienoic acids had minimal effect. Limb nitric oxide (NO) production and muscle phospho-eNOS increased in a stepwise fashion by ultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40–50% reduction in flow), ultrasound (MI 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control non-ischemic limb. Conclusions Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of eNOS. PMID:25834183

  13. Prevalence and significance of reversible radionuclide ischemic perfusion defects in symptomatic aortic valve disease patients with or without concomitant coronary disease

    SciTech Connect

    Pfisterer, M.; Mueller-Brand, J.; Bruendler, H.; Cueni, T.

    1982-01-01

    To determine the prevalence and significance of exercise-induced localized perfusion defects in symptomatic patients with aortic valve disease, thallium-201 rest and exercise studies were performed in a consecutive series of 29 such patients prior to left heart catheterization with coronary arteriography. Eight patients had repeat studies after aortic valve replacement. Twelve of 17 patients with predominant aortic regurgitation (AR) had distinct LV apical defects during exercise despite normal coronary arteries, while 10 of 12 patients with aortic valve disease and associated coronary artery disease (CAD) had localized perfusion defects in LV areas other than the apex. In patients with AR, reversible apical perfusion defects can occur without CAD; these apical defects are probably a reflection of severe LV volume overload in AR. LV perfusion defects in areas other than the apex are specific for CAD in aortic valve disease, and concomitant CAD may not provoke regional LV perfusion deficits in aortic stenosis patients with severe LV hypertrophy.

  14. Thrombolysis, Complete Recanalization, Diffusion Reversal, and Luxury Perfusion in Hyperacute Stroke.

    PubMed

    Sakamoto, Yuki; Ouchi, Takahiro; Okubo, Seiji; Abe, Arata; Aoki, Junya; Nogami, Akane; Sato, Takahiro; Hokama, Hiroyuki; Ogawa, Yutaro; Suzuki, Shizuka; Mishina, Masahiro; Kimura, Kazumi

    2016-01-01

    A 59-year old man was admitted to our stroke care unit 1.8 hours after onset of cardioembolic stroke. Administration of issue-plasminogen activator achieved complete recanalization, and his lesion on diffusion-weighted imaging (DWI) disappeared and single photon emission computed tomography showed luxury perfusion. DWI reversal and luxury perfusion were sometimes observed in hyperacute stroke patients, especially timely reperfusion was achieved. However, the relationships between DWI reversal and luxury perfusion were not well known. Transient DWI reversal may be associated with luxury perfusion in patients treated with t-PA, via early complete recanalization achieved by thrombolysis.

  15. Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD: a randomised clinical trial

    PubMed Central

    Buggeskov, Katrine B; Sundskard, Martin M; Jonassen, Thomas; Andersen, Lars W; Secher, Niels H; Ravn, Hanne B; Steinbrüchel, Daniel A; Jakobsen, Janus C; Wetterslev, Jørn

    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 patients were randomised to receive pulmonary artery perfusion during CPB with either oxygenated blood (n=30) or histidine-tryptophan-ketoglutarate (HTK) solution (n=29) compared with no pulmonary perfusion (n=31). The coprimary outcomes were the inverse oxygenation index compared at 21 hours after starting CPB and longitudinally in a mixed-effects model (MEM). Secondary outcomes were tracheal intubation time, serious adverse events, mortality, days alive outside the intensive care unit (ICU) and outside the hospital. Results 21 hours after starting CPB patients receiving pulmonary artery perfusion with normothermic oxygenated blood had a higher oxygenation index compared with no pulmonary perfusion (mean difference (MD) 0.94; 95% CI 0.05 to 1.83; p=0.04). The blood group had also a higher oxygenation index both longitudinally (MEM, p=0.009) and at 21 hours (MD 0.99; CI 0.29 to 1.69; p=0.007) compared with the HTK group. The latest result corresponds to a difference in the arterial partial pressure of oxygen of 23 mm Hg with a median fraction of inspired oxygen of 0.32. Yet the blood or HTK groups did not demonstrate a longitudinally higher oxygenation index compared with no pulmonary perfusion (MEM, p=0.57 and 0.17). Similarly, at 21 hours there was no difference in the oxygenation index between the HTK group and those no pulmonary perfusion (MD 0.06; 95% CI −0.73 to 0.86; p=0.87). There were no statistical significant differences between the groups for the secondary outcomes. Discussion Pulmonary artery perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing

  16. Assessment of myocardial perfusion in patients after the arterial switch operation

    SciTech Connect

    Vogel, M.; Smallhorn, J.F.; Gilday, D.; Benson, L.N.; Ash, J.; Williams, W.G.; Freedom, R.M. )

    1991-02-01

    In 21 patients who had undergone the arterial switch operation, the adequacy of myocardial perfusion was evaluated by thallium-201 computed scintigraphy 2.6 +/- 2 (0.3-7) yr after surgery. Fourteen patients had undergone the arterial switch procedure after pulmonary artery banding and seven as a primary repair. Isoproterenol stress increased the heart rate by at least 55%. Tomographic imaging was performed at peak stress and 3 hr later in the reperfusion phase. Nine patients had perfusion defects. The perfusion defects were located at the left ventricular apex in four (with extension to the inferolateral wall in one), left ventricular anterolateral wall in two, ventricular septum in one, left ventricular inferior wall in one, and right ventricular free wall in one. Some of these defects could be due to myocardial damage at the time of surgery, but these results also raise concern about long-term adequacy of myocardial perfusion following the arterial switch procedure.

  17. Impact of hypertension on the accuracy of exercise stress myocardial perfusion imaging for the diagnosis of coronary artery disease

    PubMed Central

    Elhendy, A; van Domburg, R T; Sozzi, F; Poldermans, D; Bax, J; Roelandt, J

    2001-01-01

    AIM—To compare the accuracy of exercise stress myocardial perfusion single photon emission computed tomography (SPECT) imaging for the diagnosis of coronary artery disease in patients with and without hypertension.
METHODS—A symptom limited bicycle exercise stress test in conjunction with 99m technetium sestamibi or tetrofosmin SPECT imaging was performed in 332 patients (mean (SD) age, 57 (10) years; 257 men, 75 women) without previous myocardial infarction who underwent coronary angiography. Of these, 137 (41%) had hypertension. Rest SPECT images were acquired 24 hours after the stress test. An abnormal scan was defined as one with reversible or fixed perfusion defects.
RESULTS—In hypertensive patients, myocardial perfusion abnormalities were detected in 79 of 102 patients with significant coronary artery disease and in nine of 35 patients without. In normotensive patients, myocardial perfusion abnormalities were detected in 104 of 138 patients with significant coronary artery disease and in 16 of 57 patients without. There were no differences between normotensive and hypertensive patients in sensitivity (77% (95% confidence interval (CI) 69% to 86%) v 75% (95% CI 68% to 83%)), specificity (74% (95% CI 60% to 89%) v 72% (95% CI 60% to 84%)), and accuracy (77% (95% CI 70% to 84%) v 74% (95% CI 68% to 80%)) of exercise SPECT for diagnosing coronary artery disease. The accuracy of SPECT was greater than electrocardiography, both in hypertensive patients (p = 0.005) and in normotensive patients (p = 0.0001). For the detection of coronary artery disease in individual vessels, sensitivity was 58% (95% CI 51% to 65%) v 57% (95% CI 51% to 64%), specificity was 86% (95% CI 82% to 90%) v 85% (95% CI 81% to 89%), and accuracy was 74% (95% CI 70% to 78%) v 74% (95% CI 70% to 78%) in patients with and without hypertension (NS).
CONCLUSIONS—In the usual clinical setting, the value of exercise myocardial perfusion scintigraphy for diagnosing

  18. Reversible changes in diffusion- and perfusion-based imaging in cerebral venous sinus thrombosis.

    PubMed

    Lin, Ning; Wong, Andrew K; Lipinski, Lindsay J; Mokin, Maxim; Siddiqui, Adnan H

    2016-02-01

    Diffusion- and perfusion-based imaging studies are regularly used in patients with ischemic stroke. Cerebral venous sinus thrombosis (CVST) is a rare cause of stroke and is primarily treated by systemic anticoagulation. Endovascular intervention can be considered in cases of failed medical therapy, yet the prognostic value of diffusion- and perfusion-based imaging for CVST has not been clearly established. We present a patient with CVST whose abnormal findings on MRI and CT perfusion images were largely reversed after endovascular treatment.

  19. High-frequency Electrocardiogram Analysis in the Ability to Predict Reversible Perfusion Defects during Adenosine Myocardial Perfusion Imaging

    NASA Technical Reports Server (NTRS)

    Tragardh, Elin; Schlegel, Todd T.; Carlsson, Marcus; Pettersson, Jonas; Nilsson, Klas; Pahlm, Olle

    2007-01-01

    Background: A previous study has shown that analysis of high-frequency QRS components (HF-QRS) is highly sensitive and reasonably specific for detecting reversible perfusion defects on myocardial perfusion imaging (MPI) scans during adenosine. The purpose of the present study was to try to reproduce those findings. Methods: 12-lead high-resolution electrocardiogram recordings were obtained from 100 patients before (baseline) and during adenosine Tc-99m-tetrofosmin MPI tests. HF-QRS were analyzed regarding morphology and changes in root mean square (RMS) voltages from before the adenosine infusion to peak infusion. Results: The best area under the curve (AUC) was found in supine patients (AUC=0.736) in a combination of morphology and RMS changes. None of the measurements, however, were statistically better than tossing a coin (AUC=0.5). Conclusion: Analysis of HF-QRS was not significantly better than tossing a coin for determining reversible perfusion defects on MPI scans.

  20. The incidence and etiology of the ventilation/perfusion reverse mismatch defect

    SciTech Connect

    Carvalho, P.; Lavender, J.P. )

    1989-08-01

    Kr-81m ventilation and Tc-99m perfusion images of 392 patients were examined retrospectively for the incidence and etiology of the reverse mismatch defect, which is characterized by a region of lung where the perfusion defect exceeds the ventilation defect. Forty-six patients (11.7%) showed such defects. The most frequent causes were pneumonia (15%), atelactasis (15%), pleural effusions (15%), chronic obstructive airway disease (24%), and bronchial obstruction (31%). The significance of the reverse mismatch defect is discussed.

  1. Hepatic arterial perfusion scintigraphy with Tc-99m-MAA: use of a totally implanted drug delivery system

    SciTech Connect

    Ziessman, H.A.; Thrall, J.H.; Yang, P.J.; Walker, S.C.; Cozzi, E.A.; Niederhuber, J.E.; Gyves, J.W.; Ensminger, W.D.; Tuscan, M.C.

    1984-07-01

    Tc-99m-MAA hepatic arterial perfusion scintigraphy (HAPS) using a totally implanted drug delivery system was employed for hepatic arterial chemotherapy in 147 patients (335 studies). Complete perfusion of the involved liver was seen in 88% of patients initially and remained good on follow-up. A significant decrease in hepatic and/or extrahepatic perfusion associated with a hot spot at the tip of the catheter indicated hepatic arterial thrombosis. Extrahepatic perfusion was seen in 14% of cases, usually in the distribution of the stomach, small bowel, and spleen. Significant symptoms of drug toxicity were seen in 70% of patients with extrahepatic perfusion, compared to 19% of those without it.

  2. Temporary arterial shunts to maintain limb perfusion after arterial injury: an animal study

    NASA Technical Reports Server (NTRS)

    Dawson, D. L.; Putnam, A. T.; Light, J. T.; Ihnat, D. M.; Kissinger, D. P.; Rasmussen, T. E.; Bradley, D. V. Jr

    1999-01-01

    BACKGROUND: Temporary shunt placement can quickly restore perfusion after extremity arterial injury. This study examined the adequacy of limb blood flow with shunt use, non-heparin-bonded shunt patency over prolonged periods, and the safety of this technique. METHODS: Common iliac arteries were divided and 4.0-mm Silastic Sundt shunts placed in 16 anesthetized pigs. Eight (group I) had shunts placed immediately; eight others (group II) were shunted after an hour of limb ischemia and hemorrhagic shock. Physiologic parameters and femoral artery blood flow in both hindlimbs were continuously monitored. Limb lactic acid generation, oxygen utilization, and hematologic and metabolic effects were serially evaluated for 24 hours. RESULTS: Shunts remained patent in 13 of 16 pigs. Shunts thrombosed in two group I animals because of technical errors, but functioned well after thrombectomy and repositioning. Patency could not be maintained in one animal that died from shock. Flow in group I shunted limbs was 57 (+/-11 SD) % of control. For group II animals in shock, shunted limb flow initially averaged 46 +/- 15% of control, but 4 hours after shunt placement, the mean limb blood flow was the same as in group I. Increased oxygen extraction compensated for the lower flow. Lactic acid production was not increased in comparison to control limbs. CONCLUSION: Shunts provided adequate flow in this model of extremity trauma. Correctly placed shunts stayed patent for 24 hours, without anticoagulation, if shunt placement followed resuscitation.

  3. Mapping of cerebral perfusion territories using territorial arterial spin labeling: techniques and clinical application.

    PubMed

    Hartkamp, Nolan S; Petersen, Esben T; De Vis, Jill B; Bokkers, Reinoud P H; Hendrikse, Jeroen

    2013-08-01

    A knowledge of the exact cerebral perfusion territory which is supplied by any artery is of great importance in the understanding and diagnosis of cerebrovascular disease. The development and optimization of territorial arterial spin labeling (T-ASL) MRI techniques in the past two decades have made it possible to visualize and determine the cerebral perfusion territories in individual patients and, more importantly, to do so without contrast agents or otherwise invasive procedures. This review provides an overview of the development of ASL techniques that aim to visualize the general cerebral perfusion territories or the territory of a specific artery of interest. The first efforts of T-ASL with pulsed, continuous and pseudo-continuous techniques are summarized and subsequent clinical studies using T-ASL are highlighted. In the healthy population, the perfusion territories of the brain-feeding arteries are highly variable. This high variability requires special consideration in specific patient groups, such as patients with cerebrovascular disease, stroke, steno-occlusive disease of the large arteries and arteriovenous malformations. In the past, catheter angiography with selective contrast injection was the only available method to visualize the cerebral perfusion territories in vivo. Several T-ASL methods, sometimes referred to as regional perfusion imaging, are now available that can easily be combined with conventional brain MRI examinations to show the relationship between the cerebral perfusion territories, vascular anatomy and brain infarcts or other pathology. Increased availability of T-ASL techniques on clinical MRI scanners will allow radiologists and other clinicians to gain further knowledge of the relationship between vasculature and patient diagnosis and prognosis. Treatment decisions, such as surgical revascularization, may, in the near future, be guided by information provided by T-ASL MRI in close correlation with structural MRI and quantitative

  4. Exercise thallium-201 perfusion scintigraphy in the assessment of coronary artery disease

    SciTech Connect

    Mahmarian, J.J.; Verani, M.S. )

    1991-05-21

    Exercise thallium-201 perfusion scintigraphy has been used extensively over the last decade for the detection and localization of coronary artery disease. Single-photon emission computed tomography (SPECT) is a refinement of presently available techniques, offering improved identification over planar imaging of individual vessel stenosis and quantification of the extent of abnormally perfused myocardium. In this review, the planar and SPECT techniques are discussed in light of the most recently published large patient series, and with regard to the many factors that affect the sensitivity and specificity of perfusion imaging in identifying coronary artery disease. The clinical implications of exercise perfusion scintigraphy and its future applications in cardiology practice are discussed.67 references.

  5. Regional myocardial perfusion at rest and during intracoronary papaverine in patients with coronary artery disease

    SciTech Connect

    Goldman, S.; Henry, R.; Ovitt, T.; Friedman, M.J.; Rosenfeld, A.; Daly, M.

    1983-03-01

    Regional myocardial perfusion was measured in 32 patients with the xenon-133 washout technique at rest and after 5 mg of intracoronary papaverine. Areas of decreased perfusion and/or decreased vasodilation were identified visually from computer-generated functional images. The locations of arteries and stenoses, obtained from identically positioned cineangiograms, were overlaid on the functional images. Perfusion rates for 62 myocardial regions were calculated and correlated with the percentage of stenosis. There was no association between degree of stenosis and perfusion at rest. Regional myocardial perfusion increased after papaverine in regions supplied by coronary arteries without stenoses (0% to 25%), 88.6 +/- 4.7 ml/min/100 gm. This increase was significantly greater (p less than 0.001) than the increase in regions supplied by 51% to 75% stenoses (23.7 +/- 6.3 ml/min/100 gm), or 76% to 99% stenoses (12.9 +/- 6.3 ml/min/100 gm), or 100% stenoses (2.5 +/- 3.8 ml/min/100 gm). Thus there was an inverse relationship between the increase in myocardial perfusion stimulated by papaverine and the degree of coronary artery stenosis measured angiographically. In regions supplied by two stenoses in series, vasodilation produced less of an increase than a single stenosis of a similar degree.

  6. Human cortical perfusion and the arterial pulse: a near-infrared spectroscopy study

    PubMed Central

    Kwan, Hon C; Cheng, Anita; Liu, Ruth; Borrett, Donald S

    2004-01-01

    Background The pulsatile nature of the arterial pulse induces a pulsatile perfusion pattern which can be observed in human cerebral cortex with non-invasive near-infrared spectroscopy. The present study attempts to establish a quantitative relation between these two events, even in situations of very weak signal-to-noise ratio in the cortical perfusion signal. The arterial pulse pattern was extracted from the left middle finger by means of plethesmographic techniques. Changes in cortical perfusion were detected with a continuous-wave reflectance spectrophotometer on the scalp overlying the left prefrontal cortex. Cross-correlation analysis was performed to provide evidence for a causal relation between the arterial pulse and relative changes in cortical total hemoglobin. In addition, the determination of the statistical significance of this relation was established by the use of phase-randomized surrogates. Results The results showed statistically significant cross correlation between the arterial and perfusion signals. Conclusions The approach designed in the present study can be utilized for a quantitative and continuous assessment of the perfusion states of the cerebral cortex in experimental and clinical settings even in situations of extremely low signal-to-noise ratio. PMID:15113424

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

    SciTech Connect

    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.

    1986-11-01

    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.

  8. Evaluation of the post-coronary artery bypass patient by myocardial perfusion scintigraphy and computed tomography

    SciTech Connect

    Engelstad, B.L.; Wagner, S.; Herfkens, R.; Botvinick, E.; Brundage, B.; Lipton, M.

    1983-09-01

    The clinical utility of /sup 201/Tl scintigraphy and of computed tomography for the noninvasive assessment of graft patency and regional myocardial perfusion was evaluated in 24 patients who had undergone aortocoronary bypass surgery. Perfusion defects on /sup 201/Tl scintigraphy (reversible or new, fixed) correlated (100% sensitivity, 78% specificity) with occlusion or stenosis of a graft or significant new native vessel disease. Graft occlusion was accurately demonstrated by dynamic computed tomography (100% sensitivity, 96% specificity) but did not uniformly correlate with regional perfusion. Perfusion defects in the distribution of patent grafts resulted from progressive native vessel disease or graft stenosis without complete occlusion. The absence of exercise-induced perfusion defects in regions of occluded grafts was attributed to suboptimal exercise, collateralization, or noncritical native vessel stenosis. The two studies provide complementary anatomic and physiologic information in the evaluation of the postbypass patient.

  9. Renal perfusion scintiscan

    MedlinePlus

    Renal perfusion scintigraphy; Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion ... supply the kidneys. This is a condition called renal artery stenosis. Significant renal artery stenosis may be ...

  10. The Autophagy Enhancer Spermidine Reverses Arterial Aging

    PubMed Central

    LaRocca, Thomas J.; Gioscia-Ryan, Rachel A.; Hearon, Christopher M.; Seals, Douglas R.

    2013-01-01

    Arterial aging, characterized by stiffening of large elastic arteries and the development of arterial endothelial dysfunction, increases cardiovascular disease (CVD) risk. We tested the hypothesis that spermidine, a nutrient associated with the anti-aging process autophagy, would improve arterial aging. Aortic pulse wave velocity (aPWV), a measure of arterial stiffness, was ~20% greater in old (O, 28 months) compared with young C57BL6 mice (Y, 4 months, P < 0.05). Arterial endothelium-dependent dilation (EDD), a measure of endothelial function, was ~25% lower in O (P < 0.05 vs. Y) due to reduced nitric oxide (NO) bioavailability. These impairments were associated with greater arterial oxidative stress (nitrotyrosine), superoxide production, and protein cross-linking (advanced glycation end-products, AGEs) in O (all P < 0.05). Spermidine supplementation normalized aPWV, restored NO-mediated EDD and reduced nitrotyrosine, superoxide, AGEs and collagen in O. These effects of spermidine were associated with enhanced arterial expression of autophagy markers, and in vitro experiments demonstrated that vascular protection by spermidine was autophagy-dependent. Our results indicate that spermidine exerts a potent anti-aging influence on arteries by increasing NO bioavailability, reducing oxidative stress, modifying structural factors and enhancing autophagy. Spermidine may be a promising nutraceutical treatment for arterial aging and prevention of age-associated CVD. PMID:23612189

  11. Reversible ischemia in severe stress Tc-99m-Sestamibi perfusion defects: Assessment with gated tomographic polar map Fourier amplitude and amplitude/perfusion ratio images and correlation with resting images

    SciTech Connect

    Williams, K.A.; Taillon, L.A.

    1994-05-01

    Reversible ischemia in myocardial segments with severe hypoperfusion ({le}50% of normal activity) on stress Tc-99m-Sestamibi (MIBI) images was assessed with ECG-gated tomographic (GSPECT) indices of myocardial thickening, as reflected by an increase in regional count density during systole. GSPECT bullseye plots were generated for each of 8 frames acquired after stress MIBI injection in 39 patients with coronary artery disease and at least one severe perfusion defect on summed SPECT images. Using first harmonic Fourier amplitude (AMP) and AMP to perfusion ratio (APR) images, regional myocardial systolic thickening was assessed using a 5-segment model, scored 0 to 3, for absent, minimal, mildly reduced or normal thickening. These data were regionally compared with defect reversibility assessed using a separate-day or a preceding same-day resting MIBI injection images, in which these segments were scored from 0 to 3 for absent, minimal, partial or complete defect reversibility. Of 91 severe stress defects, 16 showed absent, 18 minimal, 43 partial, and 14 complete reversibility on resting images. Both AMP and APR scores were in statistically significant agreement (p=.0218 and .0006) with resting image reversibility grades, with 79% (p=.0324) and 86% (p=.0001) agreement on the presence of reversibility on resting imaging, respectively. AMP correctly identified 89% of the reversibility defects on rest images, while the APR identified 99% (p=.0248 vs. AMP). On analysis of segment scores, the AMP slightly underestimated the degree of rest image reversibility (p=.0235), while APR images indicated more reversibility thin did resting images (p=.0092). In conclusion, GSPECT MIBI bullseye Fourier AMP images correlate well with the pattern of reversibility on resting MIBI in severe stress perfusion defects. When indexed for the degree of hypoperfusion, the Fourier images depict a greater degree of defect reversibility than resting MIBI images.

  12. Perfusion of veins at arterial pressure increases the expression of KLF5 and cell cycle genes in smooth muscle cells

    SciTech Connect

    Amirak, Emre; Zakkar, Mustafa; Evans, Paul C.; Kemp, Paul R.

    2010-01-01

    Vascular smooth muscle cell (VSMC) proliferation remains a major cause of veno-arterial graft failure. We hypothesised that exposure of venous SMCs to arterial pressure would increase KLF5 expression and that of cell cycle genes. Porcine jugular veins were perfused at arterial or venous pressure in the absence of growth factors. The KLF5, c-myc, cyclin-D and cyclin-E expression were elevated within 24 h of perfusion at arterial pressure but not at venous pressure. Arterial pressure also reduced the decline in SM-myosin heavy chain expression. These data suggest a role for KLF5 in initiating venous SMCs proliferation in response to arterial pressure.

  13. Radiation-induced pulmonary arterial perfusion defects: modification by D-penicillamine. [Rats; /sup 60/Co

    SciTech Connect

    Ward, W.F.

    1981-04-01

    D-penicillamine, previously shown to have a beneficial effect on radiation-induced pulmonary histopathology, was tested to determine its effect on function in the irradiated lung. Male rats were irradiated with /sup 60/Co gamma rays; half then received 10 mg D-penicillamine per day, and half received no further treatment. One to nine months after irradiation, animals were subjected to lung perfusion scans. Untreated irradiated rats exhibited hyperemia, hypoperfusion, and perfusion defects of the irradiated lung. In penicillamine-treated rats, the appearance of perfusion defects was delayed, the peak incidence and severity of the defects was reduced, and recovery from pulmonary hypoperfusion was accelerated. Thus, using functional criteria, penicillamine appears to improve arterial perfusion and to ameliorate radiation injury in the rat lung.

  14. Functional differences between the arteries perfusing gas exchange and nutritional membranes in the late chicken embryo.

    PubMed

    Mohammed, Riazudin; Cavallaro, Giacomo; Kessels, Carolina G A; Villamor, Eduardo

    2015-10-01

    The chicken extraembryonic arterial system comprises the allantoic arteries, which irrigate the gas exchange organ (the chorioallantoic membrane, CAM) and the yolk sac (YS) artery, which irrigates the nutritional organ (the YS membrane). We compared, using wire myography, the reactivity of allantoic and YS arteries from 19-day chicken embryos (total incubation 21 days). The contractions induced by KCl, the adrenergic agonists norepinephrine (NE, nonselective), phenylephrine (α1), and oxymetazoline (α2), electric field stimulation (EFS), serotonin, U46619 (TP receptor agonist), and endothelin (ET)-1 and the relaxations induced by acetylcholine (ACh), sodium nitroprusside (SNP, NO donor), forskolin (adenylate cyclase activator), and isoproterenol (β-adrenergic agonist) were investigated. Extraembryonic allantoic arteries did not show α-adrenergic-mediated contraction (either elicited by exogenous agonists or EFS) or ACh-induced (endothelium-dependent) relaxation, whereas these responses were present in YS arteries. Interestingly, the intraembryonic segment of the allantoic artery showed EFS- and α-adrenergic-induced contraction and ACh-mediated relaxation. Moreover, glyoxylic acid staining showed the presence of catecholamine-containing nerves in the YS and the intraembryonic allantoic artery, but not in the extraembryonic allantoic artery. Isoproterenol- and forskolin-induced relaxation and ET-1-induced contraction were higher in YS than in allantoic arteries, whereas serotonin- and U46619-induced contraction and SNP-induced relaxation did not significantly differ between the two arteries. In conclusion, our study demonstrates a different pattern of reactivity in the arteries perfusing the gas exchange and the nutritional membranes of the chicken embryo.

  15. Carboxypeptidase B and other kininases of the rat coronary and mesenteric arterial bed perfusates.

    PubMed

    Oliveira, Eduardo B; Souza, Laura L; Sivieri, Disney O; Bispo-da-Silva, Luiz B; Pereira, Hugo J V; Costa-Neto, Claudio M; Sousa, Marcelo V; Salgado, Maria Cristina O

    2007-12-01

    We describe the enzymes that constitute the major bradykinin (BK)-processing pathways in the perfusates of mesenteric arterial bed (MAB) and coronary vessels isolated from Wistar normotensive rats (WNR) and spontaneously hypertensive rats. The contribution of particular proteases to BK degradation was revealed by the combined analysis of fragments generated during incubation of BK with representative perfusate samples and the effect of selective inhibitors on the respective reactions. Marked differences were seen among the perfusates studied; MAB secretes, per minute of perfusion, kininase activity capable of hydrolyzing approximately 300 pmol of BK/min, which is approximately 250-fold larger amount on a per unit time basis than that of its coronary counterpart. BK degradation in the coronary perfusate seems to be mediated by ANG I-converting enzyme, neutral endopeptidase 24.11-like enzyme, and a dl-2-mercaptomethyl-3-guanidinoethylthiopropanoic acid-sensitive basic carboxypeptidase; coronary perfusate of WNR contains an additional BK-degrading enzyme whose specificity resembles that of neurolysin or thimet oligopeptidase. Diversely, a des-Arg(9)-BK-forming enzyme, responsible for nearly all of the kininase activity of MAB perfusates of WNR and spontaneously hypertensive rats, could be purified by a procedure that involved affinity chromatography over potato carboxypeptidase inhibitor-Sepharose column and shown to be structurally identical to rat pancreatic carboxypeptidase B (CPB). Comparable levels of CPB mRNA expression were observed in pancreas, liver, mesentery, and kidney, but very low levels were detected in lung, heart, aorta, and carotid artery. In conclusion, distinct BK-processing pathways operate in the perfusates of rat MAB and coronary bed, with a substantial participation of a des-Arg(9)-BK-forming enzyme identical to pancreatic CPB.

  16. Vascular smooth cell proliferation in perfusion culture of porcine carotid arteries

    SciTech Connect

    Liao, Dan; Lin, Peter H.; Yao Qizhi; Chen Changyi

    2008-08-08

    Objective of this study was to develop a novel in vitro artery culture system to study vascular smooth muscle cell (SMC) proliferation of porcine carotid arteries in response to injury, basic fibroblast growth factor (FGF2), and FGF2 conjugated with cytotoxin saporin (SAP). Perfusion-cultured porcine carotid arteries remained contractile in response to norepinephrine and relaxant to acetylcholine for up to 96 h. SMC proliferation of cultured arteries was detected by bromodeoxyuridine incorporation in both non-injured and balloon-injured arteries. In the inner layer of the vessel wall near the lumen, SMC proliferation were less than 10% in uninjured vessels, 66% in injured vessels, 80% in injured vessels with FGF2 treatment, and 5% in injured vessels with treatment of FGF2-SAP. Thus, the cultured porcine carotid arteries were viable; and the injury stimulated SMC proliferation, which was significantly enhanced by FGF2 and inhibited by FGF2-SAP.

  17. Quantitative Perfusion Analysis of First-Pass Contrast Enhancement Kinetics: Application to MRI of Myocardial Perfusion in Coronary Artery Disease

    PubMed Central

    Shah, Binita; Storey, Pippa; Iqbal, Sohah; Slater, James; Axel, Leon

    2016-01-01

    Purpose Perfusion analysis from first-pass contrast enhancement kinetics requires modeling tissue contrast exchange. This study presents a new approach for numerical implementation of the tissue homogeneity model, incorporating flexible distance steps along the capillary (NTHf). Methods The proposed NTHf model considers contrast exchange in fluid packets flowing along the capillary, incorporating flexible distance steps, thus allowing more efficient and stable calculations of the transit of tracer through the tissue. We prospectively studied 8 patients (62 ± 13 years old) with suspected CAD, who underwent first-pass perfusion CMR imaging at rest and stress prior to angiography. Myocardial blood flow (MBF) and myocardial perfusion reserve index (MPRI) were estimated using both the NTHf and the conventional adiabatic approximation of the TH models. Coronary artery lesions detected at angiography were clinically assigned to one of three categories of stenosis severity (‘insignificant’, ‘mild to moderate’ and ‘severe’) and related to corresponding myocardial territories. Results The mean MBF (ml/g/min) at rest/stress and MPRI were 0.80 ± 0.33/1.25 ± 0.45 and 1.68 ± 0.54 in the insignificant regions, 0.74 ± 0.21/1.09 ± 0.28 and 1.54 ± 0.46 in the mild to moderate regions, and 0.79 ± 0.28/0.63 ± 0.34 and 0.85 ± 0.48 in the severe regions, respectively. The correlation coefficients of MBFs at rest/stress and MPRI between the NTHf and AATH models were r = 0.97/0.93 and r = 0.91, respectively. Conclusions The proposed NTHf model allows efficient quantitative analysis of the transit of tracer through tissue, particularly at higher flow. Results of initial application to MRI of myocardial perfusion in CAD are encouraging. PMID:27583385

  18. Identification of cerebral perfusion using arterial spin labeling in patients with seizures in acute settings

    PubMed Central

    Yoo, Roh-Eul; Yoon, Byung-Woo; Lee, Sang Kun; Lee, Soon-Tae; Kang, Koung Mi; Choi, Seung Hong; Kim, Ji-hoon; Sohn, Chul-Ho; Park, Sun-Won; Han, Moon Hee

    2017-01-01

    This study aimed to explore the utility of arterial spin labeling perfusion-weighted imaging (ASL-PWI) in patients with suspected seizures in acute settings. A total of 164 patients who underwent ASL-PWI for suspected seizures in acute settings (with final diagnoses of seizure [n = 129], poststroke seizure [n = 18], and seizure mimickers [n = 17]), were included in this retrospective study. Perfusion abnormality was analyzed for: (1) pattern, (2) multifocality, and (3) atypical distribution against vascular territories. Perfusion abnormality was detected in 39% (50/129) of the seizure patients, most (94%, 47/50) being the hyperperfusion pattern. Of the patients with perfusion abnormality, multifocality or hemispheric involvement and atypical distribution against vascular territory were revealed in 46% (23/50) and 98% (49/50), respectively. In addition, seizures showed characteristic features including hyperperfusion (with or without non-territorial distribution) on ASL-PWI, thus differentiating them from poststroke seizures or seizure mimickers. In patients in whom seizure focus could be localized on both EEG and ASL-PWI, the concordance rate was 77%. The present study demonstrates that ASL-PWI can provide information regarding cerebral perfusion status in patients with seizures in acute settings and has the potential to be used as a non-invasive imaging tool to identify the cerebral perfusion in patients with seizures. PMID:28291816

  19. Arterial wall perfusion measured with photon counting spectral x-ray CT

    NASA Astrophysics Data System (ADS)

    Jorgensen, Steven M.; Korinek, Mark J.; Vercnocke, Andrew J.; Anderson, Jill L.; Halaweish, Ahmed; Leng, Shuai; McCollough, Cynthia H.; Ritman, Erik L.

    2016-10-01

    Early atherosclerosis changes perfusion of the arterial wall due to localized proliferation of the vasa vasorum. When contrast agent passes through the artery, some enters the vasa vasorum and increases radiopacity of the arterial wall. Technical challenges to detecting changes in vasa vasorum density include the thin arterial wall, partial volume averaging at the arterial lumen/wall interface and calcification within the wall. We used a photon-counting spectral CT scanner to study carotid arteries of anesthetized pigs and micro-CT of these arteries to quantify vasa vasorum density. The left carotid artery wall was injected with autologous blood to stimulate vasa vasorum angiogenesis. The scans were performed at 25-120 keV; the tube-current-time product was 550 mAs. A 60 mL bolus of iodine contrast agent was injected into the femoral vein at 5mL/s. Two seconds post injection, an axial scan was acquired at every 3 s over 60 s (i.e., 20 time points). Each time point acquired 28 contiguous transaxial slices with reconstructed voxels 0.16 x 0.16 x 1 mm3. Regions-of-interest in the outer 2/3 of the arterial wall and in the middle 2/3 of the lumen were drawn and their enhancements plotted versus time. Lumenal CT values peaked several seconds after injection and then returned towards baseline. Arterial wall CT values peaked concurrent to the lumen. The peak arterial wall enhancement in the left carotid arterial wall correlated with increased vasa vasorum density observed in micro-CT images of the isolated arteries.

  20. Arterial Wall Perfusion Measured with Photon Counting Spectral X-ray CT

    PubMed Central

    Jorgensen, Steven M.; Korinek, Mark J.; Vercnocke, Andrew J.; Anderson, Jill L.; Halaweish, Ahmed; Leng, Shuai; McCollough, Cynthia H.; Ritman, Erik L.

    2016-01-01

    Early atherosclerosis changes perfusion of the arterial wall due to localized proliferation of the vasa vasorum. When contrast agent passes through the artery, some enters the vasa vasorum and increases radiopacity of the arterial wall. Technical challenges to detecting changes in vasa vasorum density include the thin arterial wall, partial volume averaging at the arterial lumen/wall interface and calcification within the wall. We used a photon-counting spectral CT scanner to study carotid arteries of anesthetized pigs and micro-CT of these arteries to quantify vasa vasorum density. The left carotid artery wall was injected with autologous blood to stimulate vasa vasorum angiogenesis. The scans were performed at 25–120 keV; the tube-current-time product was 550 mAs. A 60 mL bolus of iodine contrast agent was injected into the femoral vein at 5mL/s. Two seconds post injection, an axial scan was acquired at every 3 s over 60 s (i.e., 20 time points). Each time point acquired 28 contiguous transaxial slices with reconstructed voxels 0.16 × 0.16 × 1 mm3. Regions-of-interest in the outer 2/3 of the arterial wall and in the middle 2/3 of the lumen were drawn and their enhancements plotted versus time. Lumenal CT values peaked several seconds after injection and then returned towards baseline. Arterial wall CT values peaked concurrent to the lumen. The peak arterial wall enhancement in the left carotid arterial wall correlated with increased vasa vasorum density observed in micro-CT images of the isolated arteries. PMID:27807391

  1. Arterial Wall Perfusion Measured with Photon Counting Spectral X-ray CT.

    PubMed

    Jorgensen, Steven M; Korinek, Mark J; Vercnocke, Andrew J; Anderson, Jill L; Halaweish, Ahmed; Leng, Shuai; McCollough, Cynthia H; Ritman, Erik L

    2016-08-28

    Early atherosclerosis changes perfusion of the arterial wall due to localized proliferation of the vasa vasorum. When contrast agent passes through the artery, some enters the vasa vasorum and increases radiopacity of the arterial wall. Technical challenges to detecting changes in vasa vasorum density include the thin arterial wall, partial volume averaging at the arterial lumen/wall interface and calcification within the wall. We used a photon-counting spectral CT scanner to study carotid arteries of anesthetized pigs and micro-CT of these arteries to quantify vasa vasorum density. The left carotid artery wall was injected with autologous blood to stimulate vasa vasorum angiogenesis. The scans were performed at 25-120 keV; the tube-current-time product was 550 mAs. A 60 mL bolus of iodine contrast agent was injected into the femoral vein at 5mL/s. Two seconds post injection, an axial scan was acquired at every 3 s over 60 s (i.e., 20 time points). Each time point acquired 28 contiguous transaxial slices with reconstructed voxels 0.16 × 0.16 × 1 mm(3). Regions-of-interest in the outer 2/3 of the arterial wall and in the middle 2/3 of the lumen were drawn and their enhancements plotted versus time. Lumenal CT values peaked several seconds after injection and then returned towards baseline. Arterial wall CT values peaked concurrent to the lumen. The peak arterial wall enhancement in the left carotid arterial wall correlated with increased vasa vasorum density observed in micro-CT images of the isolated arteries.

  2. Myocardial performance and perfusion during exercise in patients with coronary artery disease caused by Kawasaki disease

    SciTech Connect

    Paridon, S.M.; Ross, R.D.; Kuhns, L.R.; Pinsky, W.W. )

    1990-01-01

    For a study of the natural history of coronary artery lesions after Kawasaki disease and their effect on myocardial blood flow reserve with exercise, five such patients underwent exercise testing on a bicycle. Oxygen consumption, carbon dioxide production, minute ventilation, and electrocardiograms were monitored continuously. Thallium-201 scintigraphy was performed for all patients. One patient stopped exercise before exhaustion of cardiovascular reserve but had no evidence of myocardial perfusion abnormalities. Four patients terminated exercise because of exhaustion of cardiovascular reserve; one had normal cardiovascular reserve and thallium scintiscans, but the remaining patients had diminished cardiovascular reserve. Thallium scintigrams showed myocardial ischemia in two and infarction in one. No patient had exercise-induced electrocardiographic changes. These results indicate that patients with residual coronary artery lesions after Kawasaki disease frequently have reduced cardiovascular reserve during exercise. The addition of thallium scintigraphy and metabolic measurements to exercise testing improved the detection of exercise-induced abnormalities of myocardial perfusion.

  3. External carotid artery angioplasty and stenting to augment cerebral perfusion in the setting of subacute symptomatic ipsilateral internal carotid artery occlusion. Case report.

    PubMed

    Adel, Joseph G; Bendok, Bernard R; Hage, Ziad A; Naidech, Andrew M; Miller, Jeffery W; Batjer, H Hunt

    2007-12-01

    The authors performed external carotid artery (ECA) angioplasty and stenting in a 45-year-old man who had presented with right hemispheric crescendo ischemic symptoms stemming from acute right internal carotid artery occlusion (ICAO). This unique application of ECA angioplasty and stenting augmented cerebral perfusion and improved clinical symptoms. In certain situations, ECA stenting can increase cerebral perfusion in the setting of ICAO and ECA stenosis. The authors are the first to describe this approach in this context.

  4. Radiation injury in rat lung: I. Prostacyclin (PGI/sub 2/) production, arterial perfusion, and ultrastructure

    SciTech Connect

    Ts'ao, C.; Ward, W.F.; Port, C.D.

    1983-11-01

    Pulmonary prostacyclin (PGI/sub 2/) production, arterial perfusion, and ultrastructure were correlated in rats sacrificed from 1 day to 6 months after a single exposure of 25 Gy of gamma rays to the right hemithorax. PGI/sub 2/ production by the irradiated lung decreased to approximately half the normal value 1 day after irradiation (P < 0.05), then increased steadily throughout the study. By 6 months postirradiation, the right lung produced two to three times as much PGI/sub 2/ as did either shielded left lung or sham-irradiated lungs (P < 0.05). Perfusion scans revealed hyperemia of the right lung from 1 to 14 days after irradiation. From its peak at 14 days postirradiation, however, perfusion of the irradiated lung decreased steadily, then reached a plateau from 3 to 6 months at less than half that in the shielded left lung. Electron micrographs of the right lung revealed perivascular edema from 1 to 30 days after irradiation. The right lung then exhibited changes typical of radiation pneumonitis followed by progressive interstitial fibrosis. Platelet aggregates were not observed at any time. Thus, decreased PGI/sub 2/ production is an immediate but transient response of the lung to radiation injury. Then from 2 to 6 months after irradiation, the fibrotic, hypoperfused lung produces increasing amounts of the potent vasodilator and antithrombotic agent, PGI/sub 2/. Pulmonary PGI/sub 2/ production and arterial perfusion are inversely correlated for at least 6 months after hemithoracic irradiation.

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

    SciTech Connect

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

    1981-07-01

    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.

  6. Basilar artery migraine and reversible imaging abnormalities.

    PubMed

    Maytal, J; Libman, R B; Lustrin, E S

    1998-01-01

    We report a case of a basilar artery migraine in a 17-year-old boy with transient CT and MR abnormalities after each of two migraine episodes. A repeat MR study 6 months after the last event showed complete resolution of the lesion. Transient abnormalities on brain images similar to those shown in our case have been reported in patients with migraine and other neurologic conditions and are most likely related to cerebral vasogenic edema.

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

    SciTech Connect

    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)

  8. Avulsive axillary artery injury in reverse total shoulder arthroplasty.

    PubMed

    Wingert, Nathaniel C; Beck, John D; Harter, G Dean

    2014-01-01

    In addition to neurologic injuries such as peripheral nerve palsy, axillary vessel injury should be recognized as a possible complication of reverse total shoulder arthroplasty. Limb lengthening associated with Grammont-type reverse total shoulder arthroplasty places tension across the brachial plexus and axillary vessels and may contribute to observed injuries. The Grammont-type reverse total shoulder arthroplasty prosthesis reverses the shoulder ball and socket, shifts the shoulder center of rotation distal and medial, and lengthens the arm. This alteration of native anatomy converts shearing to compressive glenohumeral joint forces while augmenting and tensioning the deltoid lever arm. Joint stability is enhanced; shoulder elevation is enabled in the rotator cuff–deficient shoulder. Arm lengthening associated with reverse total shoulder arthroplasty places a longitudinal strain on the brachial plexus and axillary vessels. Peripheral nerve palsies and other neurologic complications of reverse total shoulder arthroplasty have been documented. The authors describe a patient with rotator cuff tear arthropathy and a history of radioulnar synostosis who underwent reverse total shoulder arthroplasty complicated by intraoperative injury to the axillary artery and postoperative radial, ulnar, and musculocutaneous nerve palsies. Following a seemingly unremarkable placement of reverse shoulder components, brisk arterial bleeding was encountered while approximating the incised subscapularis tendon in preparation for wound closure. Further exploration revealed an avulsive-type injury of the axillary artery. After an unsuccessful attempt at primary repair, a synthetic arterial bypass graft was placed. Reperfusion of the right upper extremity was achieved and has been maintained to date. Postoperative clinical examination and electromyographic studies confirmed ongoing radial, ulnar, and musculocutaneous neuropathies.

  9. Reproducibility of quantitative planar thallium-201 scintigraphy: quantitative criteria for reversibility of myocardial perfusion defects

    SciTech Connect

    Sigal, S.L.; Soufer, R.; Fetterman, R.C.; Mattera, J.A.; Wackers, F.J. )

    1991-05-01

    Fifty-two paired stress/delayed planar {sup 201}TI studies (27 exercise studies, 25 dipyridamole studies) were processed twice by seven technologists to assess inter- and intraobserver variability. The reproducibility was inversely related to the size of {sup 201}Tl perfusion abnormalities. Intraobserver variability was not different between exercise and dipyridamole studies for lesions of similar size. Based upon intraobserver variability, objective quantitative criteria for reversibility of perfusion abnormalities were defined. These objective criteria were tested prospectively in a separate group of 35 {sup 201}Tl studies and compared with the subjective interpretation of quantitative circumferential profiles. Overall, exact agreement existed in 78% of images (kappa statistic k = 0.66). We conclude that quantification of planar {sup 201}Tl scans is highly reproducible, with acceptable inter- and intraobserver variability. Objective criteria for lesion reversibility correlated well with analysis by experienced observers.

  10. L-Cysteine ethyl ester reverses the deleterious effects of morphine on, arterial blood-gas chemistry in tracheotomized rats.

    PubMed

    Mendoza, James; Passafaro, Rachael; Baby, Santhosh; Young, Alex P; Bates, James N; Gaston, Benjamin; Lewis, Stephen J

    2013-10-01

    This study determined whether the membrane-permeable ventilatory stimulant, L-cysteine ethylester (L-CYSee), reversed the deleterious actions of morphine on arterial blood-gas chemistry in isoflurane-anesthetized rats. Morphine (2 mg/kg, i.v.) elicited sustained decreases in arterial blood pH, pO₂ and sO₂, and increases in pCO₂ (all responses indicative of hypoventilation) and alveolar-arterial gradient (indicative of ventilation-perfusion mismatch). Injections of L-CYSee (100 μmol/kg, i.v.) reversed the effects of morphine in tracheotomized rats but were minimally active in non-tracheotomized rats. L-cysteine or L-serine ethylester (100 μmol/kg, i.v.) were without effect. It is evident that L-CYSee can reverse the negative effects of morphine on arterial blood-gas chemistry and alveolar-arterial gradient but that this positive activity is negated by increases in upper-airway resistance. Since L-cysteine and L-serine ethylester were ineffective, it is evident that cell penetrability and the sulfur moiety of L-CYSee are essential for activity. Due to its ready penetrability into the lungs, chest wall muscle and brain, the effects of L-CYSee on morphine-induced changes in arterial blood-gas chemistry are likely to involve both central and peripheral sites of action.

  11. Coronary artery bypass surgery with heparin-coated perfusion circuits and low-dose heparinization

    PubMed Central

    Mullen, John C.; Bentley, Michael J.; Gelfand, Elliot T.; Koshal, Arvind; Modry, Dennis L.; Guenther, Craig R.; Etches, Wai S.; Stang, Linda J.; Lopushinsky, Steven R.

    2002-01-01

    Objective To evaluate the safety and efficacy of heparin-coated perfusion circuits with low-dose heparinization and centrifugal pumping compared with the standard method during coronary artery bypass grafting. Design Prospective, randomized, single-blind clinical trial. Setting A primary care institution. Patients Ninety patients who underwent first-time elective coronary artery bypass grafting were eligible for the study. After giving informed consent, they were randomly assigned to 1 of 3 groups (30/group). Interventions Perfusion on regular uncoated bypass equipment with a roller pump and full-dose heparinization (300 IU/kg bolus, activated clotting time [ACT] > 400 s) (group 1), on a heparin-coated oxygenator with a centrifugal pump and full-dose heparinization (group 2) and on fully heparin-coated bypass equipment with a centrifugal pump and low-dose heparinization (100 IU/kg bolus, ACT of 180–400 s) (group 3). Standard coronary artery bypass grafting was performed. Outcome measures Postoperative bleeding, transfusion requirements and clinical outcomes. Results There were no complications related to the study protocol. Study groups were similar in terms of postoperative bleeding, transfusion requirements and clinical outcomes. Conclusions Heparin-coated cardiopulmonary bypass with low-dose heparinization and centrifugal pumping is a safe practice but showed no advantages over the use of regular uncoated bypass circuits for coronary bypass surgery. PMID:12067167

  12. Central retinal artery occlusion (reversible in sickle trait with glaucoma.

    PubMed Central

    Radius, R L; Finkelstein, D

    1976-01-01

    We report a case of central retinal artery occlusion in an 18-year-old black woman with sickle-trait haemoglobinopathy and acute glaucoma after hyphaema. The central retinal artery occlusion occurred immediately after treatment of the glaucoma with osmotic agents, raising the possibility that they played a precipitating role. We suggest that osmotic agents be used with extreme caution in sickle patients with glaucoma. The occlusion was treated by anterior chamber paracentesis with eventual return of good vision. The reversibility of retinal and optic nerve function after total ischaemia is discussed. PMID:952815

  13. Evaluation of Coronary Artery Disease Using Myocardial Elastography with Diverging Wave Imaging: Validation against Myocardial Perfusion Imaging and Coronary Angiography.

    PubMed

    Grondin, Julien; Waase, Marc; Gambhir, Alok; Bunting, Ethan; Sayseng, Vincent; Konofagou, Elisa E

    2017-02-28

    Myocardial elastography (ME) is an ultrasound-based technique that can image 2-D myocardial strains. The objectives of this study were to illustrate that 2-D myocardial strains can be imaged with diverging wave imaging and differ, on average, between normal and coronary artery disease (CAD) patients. In this study, 66 patients with symptoms of CAD were imaged with myocardial elastography before a nuclear stress test or an invasive coronary angiography. Radial cumulative strains were estimated in all patients. The end-systolic radial strain in the total cross section of the myocardium was significantly higher in normal patients (17.9 ± 8.7%) than in patients with reversible perfusion defect (6.2 ± 9.3%, p < 0.001) and patients with significant (-0.9 ± 7.4%, p < 0.001) and non-significant (3.7 ± 5.7%, p < 0.01) lesions. End-systolic radial strain in the left anterior descending, left circumflex and right coronary artery territory was found to be significantly higher in normal patients than in CAD patients. These preliminary findings indicate that end-systolic radial strain measured with ME is higher on average in healthy persons than in CAD patients and that ME has the potential to be used for non-invasive, radiation-free early detection of CAD.

  14. Ultrasound-enhanced drug delivery in a perfused ex vivo artery model

    NASA Astrophysics Data System (ADS)

    Hitchcock, Kathryn E.

    Acoustically driven stable cavitation may improve treatments of diseases in which passive penetration of drug into the target tissue is poor. Examples include atherosclerosis, in which the endothelium can prevent penetration of therapeutics into the plaque, and ischemic stroke, in which pathologically low flow of blood impedes the delivery of intravenous drugs to the clot. Understanding the way in which ultrasound cavitation agents nucleate cavitation in flowing blood-mimicking solutions is an important step in optimizing ultrasound-enhanced drug delivery. The use of a perfused, living ex vivo artery model permitted study of this phenomenon while still providing information on arterial bioeffects. Cavitation-enhanced delivery of anti-ICAM-1-targeted echogenic liposomes into and beyond the ex vivo murine aortic endothelium was demonstrated using 1-MHz continuous wave ultrasound. Acoustic cavitation had no apparent effect on the health of the murine arterial tissue. A method of maximizing the energy of stable cavitation through the use of intermittent 120-kHz ultrasound with quiescent periods to allow contrast agent inflow was developed. Using this insonificaiton method, sonothrombolysis was studied in ex vivo porcine carotid arteries using a 120-kHz center frequency and 0.44 MPa peak-to-peak pressure amplitude. Clot mass loss was used as a metric of thrombolytic efficacy. Clots exposed to recombinant tissue plasminogen activator and the ultrasound contrast agent, DefinityRTM in flowing porcine plasma without ultrasound experienced 34% mass loss. When robust stable cavitation was induced via 120-kHz insonation, the mean clot mass loss rose to 83%, which constituted a significant improvement (n = 6, p<0.0001). Without DefinityRTM there was no thrombolytic enhancement by ultrasound exposure alone at the same insonation pressure (n = 6, p<0.0001). Significant loss of endothelium occurred in 64% of the porcine carotid arteries, possibly due to poor oxygen delivery by the

  15. Cerebral perfusion during canine hypothermic cardiopulmonary bypass: effect of arterial carbon dioxide tension.

    PubMed

    Johnston, W E; Vinten-Johansen, J; DeWitt, D S; O'Steen, W K; Stump, D A; Prough, D S

    1991-09-01

    Cerebral blood flow (radioactive microspheres), intracranial pressure (subdural bolt), and retinal histopathology were examined in 20 dogs undergoing 150 minutes of hypothermic (28 degrees C) cardiopulmonary bypass to compare alpha-stat (arterial carbon dioxide tension, 40 +/- 1 mm Hg; n = 10) and pH-stat (arterial carbon dioxide tension, 61 +/- 1 mm Hg; n = 10) techniques of arterial carbon dioxide tension management. Pump flow (80 mL.kg-1.min-1), mean aortic pressure (78 +/- 2 mm Hg), and hemoglobin level (87 +/- 3 g/L [8.7 +/- 0.3 g/dL]) were maintained constant. During bypass, intracranial pressure progressively increased in the alpha-stat group from 6.0 +/- 1.0 to 13.9 +/- 1.8 mm Hg (p less than 0.05) and in the pH-stat group from 7.7 +/- 1.1 to 14.7 +/- 1.4 mm Hg (p less than 0.05), although there was no evidence of loss of intracranial compliance or intracranial edema formation as assessed by brain water content. With cooling, cerebral blood flow decreased by 56% to 62% in the alpha-stat group (p less than 0.05) and by 48% to 56% in the pH-stat group (p less than 0.05). However, 30 minutes after rewarming to 37 degrees C, cerebral blood flow in both groups failed to increase and remained significantly depressed compared with baseline values. Both groups showed similar amounts of ischemic retinal damage, with degeneration of bipolar cells found in the inner nuclear layer in 67% of animals. We conclude that, independent of the arterial carbon dioxide tension management technique, (1) cerebral perfusion decreased comparably during prolonged hypothermic bypass, (2) intracranial pressure increases progressively, (3) ischemic damage to retinal cells occurs despite maintenance of aortic pressure and flow, and (4) a significant reduction in cerebral perfusion persists after rewarming.

  16. Cyclic GMP, sodium nitroprusside and sodium azide reduce aqueous humour formation in the isolated arterially perfused pig eye.

    PubMed

    Shahidullah, Mohammad; Yap, Maurice; To, Chi-Ho

    2005-05-01

    The effect of nitric oxide (NO) on aqueous humour formation (AHF) and intraocular pressure (IOP) was studied using NO donors, sodium azide (AZ) and sodium nitroprusside (SNP). Using the porcine arterially perfused eye preparation, drug effects on AHF and IOP were measured by fluorescein dilution and manometry, respectively. Perfusion pressure of the ocular vasculature was also monitored using digital pressure transducer and pen recorder. L-Arginine (1.0 mM), a precursor of NO, but not D-arginine (1.0 mM), the inactive analogue, produced a significant reduction in AHF (28.5%) and IOP (21.1%). L-NAME (L-nitro-L-arginine) (10-100 microM), an NO synthase inhibitor, had no effect on AHF and IOP. However, L-NAME (100 microM) completely reversed L-arginine's effect. AZ and SNP reduced the AHF and IOP dose-dependently. AZ at 100 nM, 1 and 10 microM reduced AHF by 26.0, 39.7 and 51.7% and IOP by 10.8, 17.3 and 24.0%, respectively. SNP at 1, 10 and 100 microM reduced the AHF by 6.0, 24.2 and 35.4% and IOP by 3.5, 9.5 and 15.5%, respectively. 8-pCPT-cGMP (8-para-chlorophenyl-thioguanosine-3',5'-cyclic guanosine monophosphate, 10 microM), a cGMP analogue, also reduced the AHF (34.9%) and IOP (15.9%). The effects of AZ and SNP on the AHF and IOP were blocked by a soluble guanylate cyclase inhibitor ODQ (10 microM), whereas ODQ alone or combined with 8-pCPT-cGMP had no effect on the AHF and IOP. None of the drugs had any significant effect on ocular vasculature. The reduction of the AHF and IOP in the arterially perfused pig eye by nitrovasodilators is likely to involve the NO-cGMP pathway.

  17. Reduction in cerebral perfusion after heroin administration: a resting state arterial spin labeling study.

    PubMed

    Denier, Niklaus; Gerber, Hana; Vogel, Marc; Klarhöfer, Markus; Riecher-Rossler, Anita; Wiesbeck, Gerhard A; Lang, Undine E; Borgwardt, Stefan; Walter, Marc

    2013-01-01

    Heroin dependence is a chronic relapsing brain disorder, characterized by the compulsion to seek and use heroin. Heroin itself has a strong potential to produce subjective experiences characterized by intense euphoria, relaxation and release from craving. The neurofunctional foundations of these perceived effects are not well known. In this study, we have used pharmacological magnetic resonance imaging (phMRI) in 15 heroin-dependent patients from a stable heroin-assisted treatment program to observe the steady state effects of heroin (60 min after administration). Patients were scanned in a cross-over and placebo controlled design. They received an injection of their regular dose of heroin or saline (placebo) before or after the scan. As phMRI method, we used a pulsed arterial spin labeling (ASL) sequence based on a flow-sensitive alternating inversion recovery (FAIR) spin labeling scheme combined with a single-shot 3D GRASE (gradient-spin echo) readout on a 3 Tesla scanner. Analysis was performed with Statistical Parametric Mapping (SPM 8), using a general linear model for whole brain comparison between the heroin and placebo conditions. We found that compared to placebo, heroin was associated with reduced perfusion in the left anterior cingulate cortex (ACC), the left medial prefrontal cortex (mPFC) and in the insula (both hemispheres). Analysis of extracted perfusion values indicate strong effect sizes and no gender related differences. Reduced perfusion in these brain areas may indicate self- and emotional regulation effects of heroin in maintenance treatment.

  18. Transient reverse ventilation-perfusion mismatch in acute pulmonary nitrofurantoin reaction.

    PubMed

    Başoğlu, T; Erkan, L; Canbaz, F; Bernay, I; Onen, T; Sahin, M; Furtun, F; Yalin, T

    1997-08-01

    A 67-yr-old woman with a history of myocardial infarct was admitted to emergency for marked dyspnea, nonproductive cough, nausea and fever. The thorax X-ray revealed a bilateral alveolar and interstitial infiltration pattern with basal accentuation. The cardiac examinations were normal. Technegas ventilation and Tc-99m-macroaggregated albumin (MAA) perfusion scans were performed to rule out pulmonary embolism. Bilateral multiple ventilation defects with normal perfusion was observed. The patient had been taking nitrofurantoin for four days for a bladder infection. Hypersensitivity to nitrofurantoin was suspected and the drug was discontinued. An antihistaminic and anxiolytic medication was started. The majority of the clinical symptoms disappeared within 24 hours. The control chest X-rays disclosed a marked improvement. Ventilation and perfusion scans obtained 48 hours after nitrofurantoin withdrawal were normal. The drug-related pulmonary reactions should be taken into account in patients on medication. Reversible ventilation defects can be the only lung-scintigraphic finding encountered in acute pulmonary nitrofurantoin reaction.

  19. Dopaminergic Therapy Modulates Cortical Perfusion in Parkinson Disease With and Without Dementia According to Arterial Spin Labeled Perfusion Magnetic Resonance Imaging.

    PubMed

    Lin, Wei-Che; Chen, Pei-Chin; Huang, Yung-Cheng; Tsai, Nai-Wen; Chen, Hsiu-Ling; Wang, Hung-Chen; Lin, Tsu-Kung; Chou, Kun-Hsien; Chen, Meng-Hsiang; Chen, Yi-Wen; Lu, Cheng-Hsien

    2016-02-01

    Arterial spin labeling (ASL) magnetic resonance imaging analyses allow for the quantification of altered cerebral blood flow, and provide a novel means of examining the impact of dopaminergic treatments. The authors examined the cerebral perfusion differences among 17 Parkinson disease (PD) patients, 17 PD with dementia (PDD) patients, and 17 healthy controls and used ASL-MRI to assess the effects of dopaminergic therapies on perfusion in the patients. The authors demonstrated progressive widespread cortical hypoperfusion in PD and PDD and robust effects for the dopaminergic therapies. Specifically, dopaminergic medications further decreased frontal lobe and cerebellum perfusion in the PD and PDD groups, respectively. These patterns of hypoperfusion could be related to cognitive dysfunctions and disease severity. Furthermore, desensitization to dopaminergic therapies in terms of cortical perfusion was found as the disease progressed, supporting the concept that long-term therapies are associated with the therapeutic window narrowing. The highly sensitive pharmaceutical response of ASL allows clinicians and researchers to easily and effectively quantify the absolute perfusion status, which might prove helpful for therapeutic planning.

  20. miR-223 reverses experimental pulmonary arterial hypertension.

    PubMed

    Meloche, Jolyane; Le Guen, Marie; Potus, François; Vinck, Jérôme; Ranchoux, Benoit; Johnson, Ian; Antigny, Fabrice; Tremblay, Eve; Breuils-Bonnet, Sandra; Perros, Frederic; Provencher, Steeve; Bonnet, Sébastien

    2015-09-15

    Pulmonary arterial hypertension (PAH) is a devastating disease affecting lung vasculature. The pulmonary arteries become occluded due to increased proliferation and suppressed apoptosis of the pulmonary artery smooth muscle cells (PASMCs) within the vascular wall. It was recently shown that DNA damage could trigger this phenotype by upregulating poly(ADP-ribose)polymerase 1 (PARP-1) expression, although the exact mechanism remains unclear. In silico analyses and studies in cancer demonstrated that microRNA miR-223 targets PARP-1. We thus hypothesized that miR-223 downregulation triggers PARP-1 overexpression, as well as the proliferation/apoptosis imbalance observed in PAH. We provide evidence that miR-223 is downregulated in human PAH lungs, distal PAs, and isolated PASMCs. Furthermore, using a gain and loss of function approach, we showed that increased hypoxia-inducible factor 1α, which is observed in PAH, triggers this decrease in miR-223 expression and subsequent overexpression of PARP-1 allowing PAH-PASMC proliferation and resistance to apoptosis. Finally, we demonstrated that restoring the expression of miR-223 in lungs of rats with monocrotaline-induced PAH reversed established PAH and provided beneficial effects on vascular remodeling, pulmonary resistance, right ventricle hypertrophy, and survival. We provide evidence that miR-223 downregulation in PAH plays an important role in numerous pathways implicated in the disease and restoring its expression is able to reverse PAH.

  1. Ascorbate elevates perfusion pressure in the bovine extraocular long posterior ciliary artery: role of endothelium-derived hyperpolarizing factor (EDHF).

    PubMed

    Stirrat, Alison; Nelli, Silvia; McGuckin, Alicia; Ho, Vivian Wing Man; Wilson, William S; Martin, William

    2006-03-18

    Ascorbate blocks agonist-induced, endothelium-derived hyperpolarizing factor (EDHF)-mediated vasodilatation in the bovine perfused ciliary artery and this is associated with a rise in perfusion pressure. We now report the origins of this ascorbate-induced rise in perfusion pressure. In segments of ciliary artery perfused at 2.5 ml/min, the addition of ascorbate (10-150 microM) enhanced U46619-induced perfusion pressure. Ascorbate produced no enhancement in the absence of U46619, suggesting that its effects resulted not from a constrictor action but through removal of a tonic vasodilator influence. Experiments revealed the endothelial source of this vasodilator influence, and EDHF, but not nitric oxide or prostanoids, appeared to be involved. The ascorbate-induced enhancement of vasoconstrictor tone was not seen in a static myograph or in segments perfused at low rates of flow, but was seen at flow rates of 2.5 ml(-1) and above. We conclude that ascorbate augments vasoconstrictor tone through inhibition of flow-induced EDHF activity.

  2. Insulin resistance is associated with lower arterial blood flow and reduced cortical perfusion in cognitively asymptomatic middle-aged adults.

    PubMed

    Hoscheidt, Siobhan M; Kellawan, J Mikhail; Berman, Sara E; Rivera-Rivera, Leonardo A; Krause, Rachel A; Oh, Jennifer M; Beeri, Michal S; Rowley, Howard A; Wieben, Oliver; Carlsson, Cynthia M; Asthana, Sanjay; Johnson, Sterling C; Schrage, William G; Bendlin, Barbara B

    2016-01-01

    Insulin resistance (IR) is associated with poor cerebrovascular health and increased risk for dementia. Little is known about the unique effect of IR on both micro- and macrovascular flow particularly in midlife when interventions against dementia may be most effective. We examined the effect of IR as indexed by the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) on cerebral blood flow in macro- and microvessels utilizing magnetic resonance imaging (MRI) among cognitively asymptomatic middle-aged individuals. We hypothesized that higher HOMA-IR would be associated with reduced flow in macrovessels and lower cortical perfusion. One hundred and twenty cognitively asymptomatic middle-aged adults (57 ± 5 yrs) underwent fasting blood draw, phase contrast-vastly undersampled isotropic projection reconstruction (PC VIPR) MRI, and arterial spin labeling (ASL) perfusion. Higher HOMA-IR was associated with lower arterial blood flow, particularly within the internal carotid arteries (ICAs), and lower cerebral perfusion in several brain regions including frontal and temporal lobe regions. Higher blood flow in bilateral ICAs predicted greater cortical perfusion in individuals with lower HOMA-IR, a relationship not observed among those with higher HOMA-IR. Findings provide novel evidence for an uncoupling of macrovascular blood flow and microvascular perfusion among individuals with higher IR in midlife.

  3. In-vivo quantitative evaluation of perfusion zones and perfusion gradient in the deep inferior epigastric artery perforator flap

    NASA Astrophysics Data System (ADS)

    Saint-Cyr, Michel; Lakhiani, Chrisovalantis; Cheng, Angela; Mangum, Michael; Liang, Jinyang; Teotia, Sumeet; Livingston, Edward H.; Zuzak, Karel J.

    2013-03-01

    The selection of well-vascularized tissue during DIEP flap harvest remains controversial. While several studies have elucidated cross-midline perfusion, further characterization of perfusion to the ipsilateral hemiabdomen is necessary for minimizing rates of fat necrosis or partial fat necrosis in bilateral DIEP flaps. Eighteen patients (29 flaps) underwent DIEP flap harvest using a prospectively designed protocol. Perforators were marked and imaged with a novel system for quantitatively measuring tissue oxygenation, the Digital Light Hyperspectral Imager. Images were then analyzed to determine if perforator selection influenced ipsilateral flap perfusion. Flaps based on a single lateral row perforator (SLRP) were found to have a higher level of hemoglobin oxygenation in Zone I (mean %HbO2 = 76.1) compared to single medial row perforator (SMRP) flaps (%HbO2 = 71.6). Perfusion of Zone III relative to Zone I was similar between SLRP and SMRP flaps (97.4% vs. 97.9%, respectively). These differences were not statistically significant (p>0.05). Perfusion to the lateral edge of the flap was slightly greater for SLRP flaps compared SMRP flaps (92.1% vs. 89.5%, respectively). SMRP flaps had superior perfusion travelling inferiorly compared to SLRP flaps (88.8% vs. 83.9%, respectively). Overall, it was observed that flaps were better perfused in the lateral direction than inferiorly. Significant differences in perfusion gradients directed inferiorly or laterally were observed, and perforator selection influenced perfusion in the most distal or inferior aspects of the flap. This suggests broader clinical implications for flap design that merit further investigation.

  4. Skeletal muscle perfusion and stem cell delivery in muscle disorders using intra-femoral artery canulation in mice.

    PubMed

    Matthias, Nadine; Hunt, Samuel D; Wu, Jianbo; Darabi, Radbod

    2015-11-15

    Muscular dystrophies are among major inherited muscle disorders characterized by progressive muscle damage and fibrosis with no definitive cure. Recently, gene or cell based therapies have been developed to restore the missing gene expression or replace the damaged tissues. In order to test the efficiency of these therapies in mice models of muscular dystrophies, the arterial route of delivery is very advantageous as it provides uniform muscle exposure to the therapeutic agents or cells. Although there are few reports of arterial delivery of the therapeutic agents or cells in mice, there is no in-depth description and evaluation of its efficacy in perfusion of downstream muscles. This study is aimed to develop a practical method for intra-femoral artery perfusion in mice and to evaluate perfusion efficiency using near-infrared-fluorescence (NIRF) imaging as well as histology following stem cell delivery. Our results provide a practical guide to perform this delicate method in mice. By using a sensitive fluorescent dye, different muscle groups of the hindlimb have been evaluated for proper perfusion. As the final step, we have validated the efficiency of arterial cell delivery into muscles using human iPS-derived myogenic cells in an immunodeficient mouse model for Duchenne muscular dystrophy (NSG-mdx(4cv)).

  5. Arterial spin labeling perfusion predicts longitudinal decline in semantic variant primary progressive aphasia.

    PubMed

    Olm, Christopher A; Kandel, Benjamin M; Avants, Brian B; Detre, John A; Gee, James C; Grossman, Murray; McMillan, Corey T

    2016-10-01

    The objective of the study was to evaluate the prognostic value of regional cerebral blood flow (CBF) measured by arterial spin labeled (ASL) perfusion MRI in patients with semantic variant primary progressive aphasia (svPPA). We acquired pseudo-continuous ASL (pCASL) MRI and whole-brain T1-weighted structural MRI in svPPA patients (N = 13) with cerebrospinal fluid biomarkers consistent with frontotemporal lobar degeneration pathology. Follow-up T1-weighted MRI was available in a subset of patients (N = 8). We performed whole-brain comparisons of partial volume-corrected CBF and cortical thickness between svPPA and controls, and compared baseline and follow-up cortical thickness in regions of significant hypoperfusion and hyperperfusion. Patients with svPPA showed partial volume-corrected hypoperfusion relative to controls in left temporal lobe and insula. svPPA patients also had typical cortical thinning in anterior temporal, insula, and inferior frontal regions at baseline. Volume-corrected hypoperfusion was seen in areas of significant cortical thinning such as the left temporal lobe and insula. Additional regions of hypoperfusion corresponded to areas without cortical thinning. We also observed regions of hyperperfusion, some associated with cortical thinning and others without cortical thinning, including right superior temporal, inferior parietal, and orbitofrontal cortices. Regions of hypoperfusion and hyperperfusion near cortical thinning at baseline had significant longitudinal thinning between baseline and follow-up scans, but perfusion changes in distant areas did not show progressive thinning. Our findings suggest ASL MRI may be sensitive to functional changes not readily apparent in structural MRI, and specific changes in perfusion may be prognostic markers of disease progression in a manner consistent with cell-to-cell spreading pathology.

  6. 'Luxury perfusion syndrome' in a patient with reversible ischemic neurological deficits.

    PubMed

    Banzo, J; Morales, F; Abós, M D; Pascual, L F; Prats, E; Teijeiro, J

    1983-01-01

    A 28-year-old man was admitted to the hospital with difficulty in speech and motor weakness of the right arm of sudden onset. Twelve years previously a grade I oligodendroglioma had been removed. The CT scan showed a low density area without enhancement in the left frontal region that appeared to communicate with the left lateral ventricle. An increased flow through the left middle cerebral-artery and a focal avascular area in the left hemisphere was noted during a dynamic study by angioscintigraphy. A radionuclide cerebral control study showed reduced flow through the left middle cerebral artery. The patient was discharged 25 days after admission with the diagnosis of (1) reversible ischemic neurological deficits associated a hyperperfusion and (2) porencephaly.

  7. Myocardial perfusion distribution and coronary arterial pressure and flow signals: clinical relevance in relation to multiscale modeling, a review.

    PubMed

    Nolte, Froukje; Hyde, Eoin R; Rolandi, Cristina; Lee, Jack; van Horssen, Pepijn; Asrress, Kal; van den Wijngaard, Jeroen P H M; Cookson, Andrew N; van de Hoef, Tim; Chabiniok, Radomir; Razavi, Reza; Michler, Christian; Hautvast, Gilion L T F; Piek, Jan J; Breeuwer, Marcel; Siebes, Maria; Nagel, Eike; Smith, Nic P; Spaan, Jos A E

    2013-11-01

    Coronary artery disease, CAD, is associated with both narrowing of the epicardial coronary arteries and microvascular disease, thereby limiting coronary flow and myocardial perfusion. CAD accounts for almost 2 million deaths within the European Union on an annual basis. In this paper, we review the physiological and pathophysiological processes underlying clinical decision making in coronary disease as well as the models for interpretation of the underlying physiological mechanisms. Presently, clinical decision making is based on non-invasive magnetic resonance imaging, MRI, of myocardial perfusion and invasive coronary hemodynamic measurements of coronary pressure and Doppler flow velocity signals obtained during catheterization. Within the euHeart project, several innovations have been developed and applied to improve diagnosis-based understanding of the underlying biophysical processes. Specifically, MRI perfusion data interpretation has been advanced by the gradientogram, a novel graphical representation of the spatiotemporal myocardial perfusion gradient. For hemodynamic data, functional indices of coronary stenosis severity that do not depend on maximal vasodilation are proposed and the Valsalva maneuver for indicating the extravascular resistance component of the coronary circulation has been introduced. Complementary to these advances, model innovation has been directed to the porous elastic model coupled to a one-dimensional model of the epicardial arteries. The importance of model development is related to the integration of information from different modalities, which in isolation often result in conflicting treatment recommendations.

  8. Determination of skeletal muscle perfusion using arterial spin labeling NMRI: validation by comparison with venous occlusion plethysmography.

    PubMed

    Raynaud, J S; Duteil, S; Vaughan, J T; Hennel, F; Wary, C; Leroy-Willig, A; Carlier, P G

    2001-08-01

    T(1)-based determination of perfusion was performed with the high temporal and spatial resolution that monitoring of exercise physiology requires. As no data were available on the validation of this approach in human muscles, T(1)-based NMRI of perfusion was compared to standard strain-gauge venous occlusion plethysmography performed simultaneously within a 4 T magnet. Two different situations were investigated in 21 healthy young volunteers: 1) a 5-min ischemia of the leg, or 2) a 2-3 min ischemic exercise consisting of a plantar flexion on an amagnetic ergometer. Leg perfusion was monitored over 5-15 min of the recovery phase, after the air-cuff arterial occlusion had been released. The interesting features of the sequence were the use of a saturation-recovery module for the introduction of a T(1) modulation and of single-shot spin echo for imaging. Spatial resolution was 1.7 x 2.0 mm and temporal resolution was 2 s. For data analysis, ROIs were traced on different muscles and perfusion was calculated from the differences in muscle signal intensity in successive images. To allow comparison with the global measurement of perfusion by plethysmography, the T(1)-based NMR measurements in exercising muscles were rescaled to the leg cross-section. The perfusion measurements obtained by plethysmography and NMRI were in close agreement with a correlation coefficient between 0.87 and 0.92. This indicates that pulsed arterial techniques provide determination of muscle perfusion not only with superior spatial and temporal resolution but also with exactitude.

  9. Routine Use of Distal Arterial Perfusion in Pediatric Femoral Venoarterial Extracorporeal Membrane Oxygenation.

    PubMed

    Schad, Christine A; Fallon, Brian P; Monteagudo, Julie; Okochi, Shunpei; Cheung, Eva W; Morrissey, Nicholas J; Kadenhe-Chiweshe, Angela V; Aspelund, Gudrun; Stylianos, Steven; Middlesworth, William

    2017-01-01

    Lower-extremity ischemia is a significant complication in children on femoral venoarterial extracorporeal membrane oxygenation (VA ECMO). Our institution currently routinely uses distal perfusion catheters (DPCs) in all femoral arterial cannulations in attempts to reduce ischemia. We performed a single-center, retrospective review of pediatric patients supported with femoral VA ECMO from January 2005 to November 2015. The outcomes of patients with prophylactic DPC placement at cannulation (prophylactic DPC) were compared to a historical group with DPCs placed in response only to clinically evident ischemic changes (reactive DPC). Ischemic complication requiring invasive intervention (fasciotomy or amputation) was the primary outcome. Twenty-nine patients underwent a total of 31 femoral arterial cannulations, 17 with prophylactic DPC and 14 with reactive DPC. Ischemic complications requiring invasive intervention developed in 2 of 17 (12%) prophylactic DPC patients versus 4 of 14 (29%) reactive DPC. In the reactive DPC group, 7 of 14 (50%) had ischemic changes postcannulation, six underwent DPC placement, and three out of six of these patients still required invasive intervention. One of the seven patients had ischemic changes, did not undergo DPC, and required amputation. While a greater percentage of patients in the prophylactic group was cannulated during extracorporeal cardiopulmonary resuscitation (ECPR), statistical significance was not otherwise demonstrated. We demonstrate feasibility of superficial femoral artery (SFA) access in pediatric patients. We note fewer ischemic complications with prophylactic DPC placement, and observe that salvaging a limb with a reactive DPC was only successful 50% of the time. Although there was no statistical difference in the primary outcome between the two groups, limitations and confounding factors include small sample size and a greater percentage of patients in the prophylactic DPC group cannulated with ECPR in progress.

  10. A Perfusion-based Human Cadaveric Model for Management of Carotid Artery Injury during Endoscopic Endonasal Skull Base Surgery

    PubMed Central

    Pham, Martin; Kale, Aydemir; Marquez, Yvette; Winer, Jesse; Lee, Brian; Harris, Brianna; Minnetti, Michael; Carey, Joseph; Giannotta, Steven; Zada, Gabriel

    2014-01-01

    Objective To create and develop a reproducible and realistic training environment to prepare residents and trainees for arterial catastrophes during endoscopic endonasal surgery. Design An artificial blood substitute was perfused at systolic blood pressures in eight fresh human cadavers to mimic intraoperative scenarios. Setting The USC Keck School of Medicine Fresh Tissue Dissection Laboratory was used as the training site. Participants Trainees were USC neurosurgery residents and junior faculty. Main Outcome A 5-point questionnaire was used to assess pre- and posttraining confidence scores. Results High-pressure extravasation at normal arterial blood pressure mimicked real intraoperative internal carotid artery (ICA) injury. Residents developed psychomotor skills required to achieve hemostasis using suction, cottonoids, and muscle grafts. Questionnaire responses from all trainees reported a realistic experience enhanced by the addition of the perfusion model. Conclusions The addition of an arterial perfusion system to fresh tissue cadavers is among the most realistic training models available. This enables the simulation of rare intraoperative scenarios such as ICA injury. Strategies for rapid hemostasis and implementation of techniques including endoscope manipulation, suction, and packing can all be rehearsed via this novel paradigm. PMID:25301092

  11. Partial volume correction of brain perfusion estimates using the inherent signal data of time-resolved arterial spin labeling.

    PubMed

    Ahlgren, André; Wirestam, Ronnie; Petersen, Esben Thade; Ståhlberg, Freddy; Knutsson, Linda

    2014-09-01

    Quantitative perfusion MRI based on arterial spin labeling (ASL) is hampered by partial volume effects (PVEs), arising due to voxel signal cross-contamination between different compartments. To address this issue, several partial volume correction (PVC) methods have been presented. Most previous methods rely on segmentation of a high-resolution T1 -weighted morphological image volume that is coregistered to the low-resolution ASL data, making the result sensitive to errors in the segmentation and coregistration. In this work, we present a methodology for partial volume estimation and correction, using only low-resolution ASL data acquired with the QUASAR sequence. The methodology consists of a T1 -based segmentation method, with no spatial priors, and a modified PVC method based on linear regression. The presented approach thus avoids prior assumptions about the spatial distribution of brain compartments, while also avoiding coregistration between different image volumes. Simulations based on a digital phantom as well as in vivo measurements in 10 volunteers were used to assess the performance of the proposed segmentation approach. The simulation results indicated that QUASAR data can be used for robust partial volume estimation, and this was confirmed by the in vivo experiments. The proposed PVC method yielded probable perfusion maps, comparable to a reference method based on segmentation of a high-resolution morphological scan. Corrected gray matter (GM) perfusion was 47% higher than uncorrected values, suggesting a significant amount of PVEs in the data. Whereas the reference method failed to completely eliminate the dependence of perfusion estimates on the volume fraction, the novel approach produced GM perfusion values independent of GM volume fraction. The intra-subject coefficient of variation of corrected perfusion values was lowest for the proposed PVC method. As shown in this work, low-resolution partial volume estimation in connection with ASL perfusion

  12. Quantitative, dynamic and noninvasive determination of skeletal muscle perfusion in mouse leg by NMR arterial spin-labeled imaging.

    PubMed

    Bertoldi, Didier; Loureiro de Sousa, Paulo; Fromes, Yves; Wary, Claire; Carlier, Pierre G

    2008-11-01

    Because mouse may relatively easily be genetically tailored to develop equivalent of human muscular diseases or to present controlled alterations of mechanisms involved in vasoregulation, it has become the prevalent species to explore such questions. However, the very small size of the animals represents a serious limitation when evaluating the functional consequences of these genetic manipulations. In this context, the recourse to arterial spin labeling (ASL) nuclear magnetic resonance (NMR) methods in which arterial water spins act as an endogenous and freely diffusible tracer of perfusion is tempting but challenging. This article shows that despite the small size of the animal, mouse muscle perfusion may be measured, at rest and in conditions of reactive hyperemia, using saturation inversion recovery sequence, a pulsed ASL variant, combined with NMR imaging. Baseline perfusion values in the mouse leg were 17+/-11 ml.min(-1).100 g(-1) (n=11) and were comparable to microsphere data from the literature. Under ischemia, leg perfusion was 1.2+/-9.3 ml.min(-1).100 g(-1) (n=11). The difference observed between basal and ischemic measurements was statistically different (P=.0001). The temporal pattern of hyperemia in mouse muscle was coherent with previously published measurements in humans and in rats. The mean peak perfusion was 62+/-24 ml.min(-1).100 g(-1) (n=6) occurring 48+/-27 s after the end of occlusion. In conclusion, this study demonstrated the ability of ASL combined to NMR imaging to quantify skeletal muscle perfusion in mice legs, both at rest and dynamically.

  13. Usefulness of the severity and extent of reversible perfusion defects during thallium-dipyridamole imaging for cardiac risk assessment before noncardiac surgery

    SciTech Connect

    Lette, J.; Waters, D.; Lapointe, J.; Gagnon, A.; Picard, M.; Cerino, M.; Kerouac, M. )

    1989-08-01

    Thallium-dipyridamole imaging is a very sensitive test for predicting cardiac events after noncardiac surgery, but it lacks specificity. To improve specificity, a semiquantitative scoring system was developed that combined dipyridamole-induced reversible left ventricular dilatation with scintigraphic indexes for severity and extent of reversible perfusion defects. Using this scoring system, patients were classified into low, intermediate and high risk subgroups. Thallium-dipyridamole imaging was performed in 66 patients before major general and vascular surgery. Thirty-nine patients classified as low risk (30 with normal scans and 9 with fixed defects) underwent surgery uneventfully. Surgery was cancelled in 6 patients with extensive thallium redistribution and coronary angiography was performed because of severe coronary artery disease in 5 and idiopathic dilated cardiomyopathy in 1. In the remaining 21 patients with thallium redistribution, a positive statistical correlation (p = 0.001) between scintigraphic indexes of severity and extent, and cardiac events was noted. Using cutoff values for the scintigraphic indexes, patients with reversible defects could be classified into intermediate and high risk subgroups. Only 1 of 11 patients at intermediate risk developed a complication, whereas 8 of 10 patients at high risk had a postoperative event (7 deaths and 1 myocardial infarction). Thus, using scintigraphic indexes for severity and extent, patients with reversible defects can be stratified into an intermediate risk subgroup that can safely undergo surgery and a high risk subgroup that requires coronary angiography.

  14. Myocardial perfusion as an indicator of graft patency after coronary artery bypass surgery. [Thallium 201

    SciTech Connect

    Kolibash, A.J.; Call, T.D.; Bush, C.A.; Tetalman, M.R.; Lewis, R.P.

    1980-05-01

    Stress and resting myocardial perfusion were assessed in 38 patients who received 96 grafts. Stress perfusion was evaluated with thallium-201 and resting myocardial blood flow distribution with radiolabeled particles. When both stress and rest perfusion were normal, graft patency was 82% (51 of 62 grafts). Graft patency was also high (81%, 13 of 16) in areas where stress perfusion abnormalities resolved or become less apparent at rest. However, when stress perfusion defects remained unchanged at rest, the graf was likely to be occuluded (73%, 11 of 15). Maintenance of normal rest perfusion or improvement of rest perfusion postoperatively was also associated with a high graft patency rate (80%, 35 of 44), whereas the development of new rest perfusion defects postoperatively implied graft occlusion (86%, six of seven).

  15. Comparing model-based and model-free analysis methods for QUASAR arterial spin labeling perfusion quantification.

    PubMed

    Chappell, Michael A; Woolrich, Mark W; Petersen, Esben T; Golay, Xavier; Payne, Stephen J

    2013-05-01

    Amongst the various implementations of arterial spin labeling MRI methods for quantifying cerebral perfusion, the QUASAR method is unique. By using a combination of labeling with and without flow suppression gradients, the QUASAR method offers the separation of macrovascular and tissue signals. This permits local arterial input functions to be defined and "model-free" analysis, using numerical deconvolution, to be used. However, it remains unclear whether arterial spin labeling data are best treated using model-free or model-based analysis. This work provides a critical comparison of these two approaches for QUASAR arterial spin labeling in the healthy brain. An existing two-component (arterial and tissue) model was extended to the mixed flow suppression scheme of QUASAR to provide an optimal model-based analysis. The model-based analysis was extended to incorporate dispersion of the labeled bolus, generally regarded as the major source of discrepancy between the two analysis approaches. Model-free and model-based analyses were compared for perfusion quantification including absolute measurements, uncertainty estimation, and spatial variation in cerebral blood flow estimates. Major sources of discrepancies between model-free and model-based analysis were attributed to the effects of dispersion and the degree to which the two methods can separate macrovascular and tissue signal.

  16. Signal changes on magnetic resonance perfusion images with arterial spin labeling after carotid endarterectomy

    PubMed Central

    Shimogawa, Takafumi; Morioka, Takato; Sayama, Tetsuro; Haga, Sei; Akiyama, Tomoaki; Murao, Kei; Kanazawa, Yuka; Furuta, Yoshihiko; Sakata, Ayumi; Arakawa, Shuji

    2016-01-01

    Background: Cerebral hyperperfusion after carotid endarterectomy (CEA) is defined as an increase in ipsilateral cerebral blood flow (CBF). Practically, however, prompt and precise assessment of cerebral hyperperfusion is difficult because of limitations in the methodology of CBF measurement during the perioperative period. Arterial spin labeling (ASL) is a completely noninvasive and repeatable magnetic resonance perfusion imaging technique that uses magnetically-labelled blood water as an endogenous tracer. To clarify the usefulness of ASL in the management of cerebral hyperperfusion, we investigated signal changes by ASL with a single 1.5-s post-labeling delay on visual inspection. Methods: Thirty-two consecutive patients who underwent CEA were enrolled in this retrospective study. Results: On postoperative day 1, 22 (68.8%) and 4 (12.5%) patients exhibited increased ASL signals bilaterally (Group A) and on the operated side (Group B), respectively. Follow-up ASL showed improvement in these findings. Six (18.8%) patients showed no change (Group C). There was no apparent correlation between ASL signals on postoperative day 1 and the preoperative hemodynamic state, including the cerebrovascular reserve (P = 0.2062). Three (9.4%) patients developed cerebral hyperperfusion syndrome (two in Group A and one in Group B). Coincidence in the localization of increased ASL signals and electroencephalographic abnormalities was noted in these patients. Conclusion: Visual analysis of ASL with a single post-labeling delay overestimates CBF and cannot identify patients at risk of cerebral hyperperfusion syndrome probably because of the strong effect of the shortened arterial transit time immediately after CEA. However, ASL may be used as for screening. PMID:28144479

  17. Acute effects of alcohol on brain perfusion monitored with arterial spin labeling magnetic resonance imaging in young adults.

    PubMed

    Marxen, Michael; Gan, Gabriela; Schwarz, Daniel; Mennigen, Eva; Pilhatsch, Maximilian; Zimmermann, Ulrich S; Guenther, Matthias; Smolka, Michael N

    2014-03-01

    While a number of studies have established that moderate doses of alcohol increase brain perfusion, the time course of such an increase as a function of breath alcohol concentration (BrAC) has not yet been investigated, and studies differ about regional effects. Using arterial spin labeling (ASL) magnetic resonance imaging, we investigated (1) the time course of the perfusion increase during a 15-minute linear increase of BrAC up to 0.6 g/kg followed by a steady exposure of 100 minutes, (2) the regional distribution, (3) a potential gender effect, and (4) the temporal stability of perfusion effects. In 48 young adults who participated in the Dresden longitudinal study on alcohol effects in young adults, we observed (1) a 7% increase of global perfusion as compared with placebo and that perfusion and BrAC are tightly coupled in time, (2) that the increase reaches significance in most regions of the brain, (3) that the effect is stronger in women than in men, and (4) that an acute tolerance effect is not observable on the time scale of 2 hours. Larger studies are needed to investigate the origin and the consequences of the effect, as well as the correlates of inter-subject variations.

  18. Hepatic perfusion abnormalities during treatment with hepatic arterial infusion chemotherapy: Value of CT arteriography using an implantable port system

    SciTech Connect

    Seki, Hiroshi; Kimura, Motomasa; Kamura, Takeshi; Miura, Tsutomu

    1996-05-01

    The purpose of this study was to evaluate CT arteriography (CTA) using an implantable port system in the detection of perfusion abnormalities occurring during hepatic arterial infusion chemotherapy (HAIC). In 51 patients with unresectable primary and metastatic liver tumors, who had implanted port systems for HAIC, CTA examinations through the infusion pump were performed. When perfusion abnormalities were found, selective angiography and/or digital subtraction angiography using the implantable port system were performed to determine the etiology. Forty-nine perfusion abnormalities were detected in 32 patients. Intrahepatic hypoperfusion was found in 24 cases. Of 11 patients in whom correction of the hypoperfusion was attempted, it was successful in 10. Of 13 patients in whom correction was not attempted, 6 patients showed progressive disease in nonperfused areas. Intrahepatic hyperperfusion was found in 14 cases, which showed no subsequent complication. Extrahepatic perfusion was found in 11 cases. We consider CTA to be useful in detecting perfusion abnormalities that may compromise HAIC. 22 refs., 3 figs., 3 tabs.

  19. Electrophysiological Characterization of The Cerebellum in the Arterially Perfused Hindbrain and Upper Body of The Rat

    PubMed Central

    Rawson, John A.; Apps, Richard

    2009-01-01

    In the present study, a non-pulsatile arterially perfused hindbrain and upper body rat preparation is described which is an extension of the brainstem preparation reported by Potts et al., (Brain Res Bull 53(1):59–67), 1. The modified in situ preparation allows study of cerebellar function whilst preserving the integrity of many of its interconnections with the brainstem, upper spinal cord and the peripheral nervous system of the head and forelimbs. Evoked mossy fibre, climbing fibre and parallel fibre field potentials and EMG activity elicited in forelimb biceps muscle by interpositus stimulation provided evidence that both cerebellar inputs and outputs remain operational in this preparation. Similarly, the spontaneous and evoked single unit activity of Purkinje cells, putative Golgi cells, molecular interneurones and cerebellar nuclear neurones was similar to activity patterns reported in vivo. The advantages of the preparation include the ability to record, without the complications of anaesthesia, stabile single unit activity for extended periods (3 h or more), from regions of the rat cerebellum that are difficult to access in vivo. The preparation should therefore be a useful adjunct to in vitro and in vivo studies of neural circuits underlying cerebellar contributions to movement control and motor learning. PMID:20033360

  20. Evaluation of Extrahepatic Perfusion of Anticancer Drugs in the Right Gastric Arterial Region on Fused Images Using Combined CT/SPECT: Is Extrahepatic Perfusion Predictive of Gastric Toxicity?

    SciTech Connect

    Ikeda, Osamu Tamura, Yoshitaka; Nakasone, Yutaka; Shiraishi, Shinya; Kawanaka, Kouichi; Tomiguchi, Seiji; Morishita, Shouji; Takamori, Hiroshi; Chikamoto, Akira; Kanemitsu, Keiichirou; Yamashita, Yasuyuki

    2007-06-15

    Background. Hepatic arterial infusion (HAI) chemotherapy is effective for treating primary and metastatic carcinomas of the liver. Since hepatic arteries also supply the stomach and duodenum, HAI may result in unwanted infusion into the upper gastrointestinal tract and consequent gastric toxicity. Using fused images obtained with a combined SPECT/CT system, we assessed extrahepatic perfusion (EHP) and its correlation with gastrointestinal toxicity in patients receiving HAI. Methods. We studied 41 patients with primary or metastatic carcinoma of the liver who received HAI chemotherapy consisting of 5-fluorouracil and cisplatin. All underwent abdominal SPECT using a {sup 99m}Tc-MAA (185 MBq) instrument and an injection rate of 0.1 ml/min, identical to the chemotherapy infusion rate. Delivery was through an implantable port. We analyzed the distribution of the anticancer agent on fused images and the relationship between EHP of the right gastric arterial region and gastric toxicity. All patients underwent esophagogastroduodenoscopy (EGDS). Results. Of the 41 patients, 11 (27%) manifested enhancement of the duodenal and gastric pyloric region on fused images. EGDS at the time of reservoir placement detected gastric ulcers in 10 of these patients. Conclusion. Fusion imaging with combined SPECT/CT reflects the actual distribution of the infused anticancer agents. The detection of EHP on fused images is predictive of the direct gastric toxicity from anticancer agents in patients undergoing HAI.

  1. Mapping the dynamics of brain perfusion using functional ultrasound in a rat model of transient middle cerebral artery occlusion.

    PubMed

    Brunner, Clément; Isabel, Clothilde; Martin, Abraham; Dussaux, Clara; Savoye, Anne; Emmrich, Julius; Montaldo, Gabriel; Mas, Jean-Louis; Baron, Jean-Claude; Urban, Alan

    2017-01-01

    Following middle cerebral artery occlusion, tissue outcome ranges from normal to infarcted depending on depth and duration of hypoperfusion as well as occurrence and efficiency of reperfusion. However, the precise time course of these changes in relation to tissue and behavioral outcome remains unsettled. To address these issues, a three-dimensional wide field-of-view and real-time quantitative functional imaging technique able to map perfusion in the rodent brain would be desirable. Here, we applied functional ultrasound imaging, a novel approach to map relative cerebral blood volume without contrast agent, in a rat model of brief proximal transient middle cerebral artery occlusion to assess perfusion in penetrating arterioles and venules acutely and over six days thanks to a thinned-skull preparation. Functional ultrasound imaging efficiently mapped the acute changes in relative cerebral blood volume during occlusion and following reperfusion with high spatial resolution (100 µm), notably documenting marked focal decreases during occlusion, and was able to chart the fine dynamics of tissue reperfusion (rate: one frame/5 s) in the individual rat. No behavioral and only mild post-mortem immunofluorescence changes were observed. Our study suggests functional ultrasound is a particularly well-adapted imaging technique to study cerebral perfusion in acute experimental stroke longitudinally from the hyper-acute up to the chronic stage in the same subject.

  2. Waveform patterns and peak reversed velocity in vertebral arteries predict severe subclavian artery stenosis and occlusion.

    PubMed

    Chen, Shun-Ping; Hu, Yuan-Ping

    2015-05-01

    This study investigated the value of analyzing spectral Doppler waveform patterns and measuring the peak reversed velocity (PRV) of the vertebral artery (VA) in predicting proximal severe subclavian artery (SA) stenosis and occlusion. Fifty-one patients with proximal SA stenosis were studied retrospectively. Based on the depth of the mid-systolic notch, the Doppler waveforms of the ipsilateral VA were divided into five subtypes (type I, n = 8; type II, n = 8; type III, n = 6; type IV, n = 13; and type V, n = 16). PRV was also measured. PRV receiver operating characteristic curves were constructed to obtain the best cutoff value for predicting severe SA stenosis or complete SA occlusion. The results indicated that both VA Doppler waveform and PRV were associated with the degree of SA stenosis (p < 0.05). PRV and the Doppler waveform in the VA had similar accuracy in predicting SA occlusion (84.3%, 43/51). PRV was more accurate than VA waveforms in predicting severe SA stenosis (98%, 50/51 vs. 94.1%, 48/51). However, no significant differences between the two methods in predicting severe SA stenosis were observed (p = 0.84). Thus, with severe obstruction of the SA, typical Doppler waveform patterns of the VA could be observed. PRV is a helpful criterion in predicting severe stenosis and occlusion of the SA.

  3. Recommended implementation of arterial spin-labeled perfusion MRI for clinical applications: A consensus of the ISMRM perfusion study group and the European consortium for ASL in dementia.

    PubMed

    Alsop, David C; Detre, John A; Golay, Xavier; Günther, Matthias; Hendrikse, Jeroen; Hernandez-Garcia, Luis; Lu, Hanzhang; MacIntosh, Bradley J; Parkes, Laura M; Smits, Marion; van Osch, Matthias J P; Wang, Danny J J; Wong, Eric C; Zaharchuk, Greg

    2015-01-01

    This review provides a summary statement of recommended implementations of arterial spin labeling (ASL) for clinical applications. It is a consensus of the ISMRM Perfusion Study Group and the European ASL in Dementia consortium, both of whom met to reach this consensus in October 2012 in Amsterdam. Although ASL continues to undergo rapid technical development, we believe that current ASL methods are robust and ready to provide useful clinical information, and that a consensus statement on recommended implementations will help the clinical community to adopt a standardized approach. In this review, we describe the major considerations and trade-offs in implementing an ASL protocol and provide specific recommendations for a standard approach. Our conclusion is that as an optimal default implementation, we recommend pseudo-continuous labeling, background suppression, a segmented three-dimensional readout without vascular crushing gradients, and calculation and presentation of both label/control difference images and cerebral blood flow in absolute units using a simplified model.

  4. Spaceflight-induced alterations in cerebral artery vasoconstrictor, mechanical, and structural properties: implications for elevated cerebral perfusion and intracranial pressure

    PubMed Central

    Taylor, Curtis R.; Hanna, Mina; Behnke, Bradley J.; Stabley, John N.; McCullough, Danielle J.; Davis, Robert T.; Ghosh, Payal; Papadopoulos, Anthony; Muller-Delp, Judy M.; Delp, Michael D.

    2013-01-01

    Evidence indicates that cerebral blood flow is both increased and diminished in astronauts on return to Earth. Data from ground-based animal models simulating the effects of microgravity have shown that decrements in cerebral perfusion are associated with enhanced vasoconstriction and structural remodeling of cerebral arteries. Based on these results, the purpose of this study was to test the hypothesis that 13 d of spaceflight [Space Transportation System (STS)-135 shuttle mission] enhances myogenic vasoconstriction, increases medial wall thickness, and elicits no change in the mechanical properties of mouse cerebral arteries. Basilar and posterior communicating arteries (PCAs) were isolated from 9-wk-old female C57BL/6 mice for in vitro vascular and mechanical testing. Contrary to that hypothesized, myogenic vasoconstrictor responses were lower and vascular distensibility greater in arteries from spaceflight group (SF) mice (n=7) relative to ground-based control group (GC) mice (n=12). Basilar artery maximal diameter was greater in SF mice (SF: 236±9 μm and GC: 215±5 μm) with no difference in medial wall thickness (SF: 12.4±1.6 μm; GC: 12.2±1.2 μm). Stiffness of the PCA, as characterized via nanoindentation, was lower in SF mice (SF: 3.4±0.3 N/m; GC: 5.4±0.8 N/m). Collectively, spaceflight-induced reductions in myogenic vasoconstriction and stiffness and increases in maximal diameter of cerebral arteries signify that elevations in brain blood flow may occur during spaceflight. Such changes in cerebral vascular control of perfusion could contribute to increases in intracranial pressure and an associated impairment of visual acuity in astronauts during spaceflight.—Taylor, C. R., Hanna, M., Behnke, B. J., Stabley, J. N., McCullough, D. J., Davis III, R. T., Ghosh, P., Papadopoulos, A., Muller-Delp, J. M., Delp, M. D. Spaceflight-induced alterations in cerebral artery vasoconstrictor, mechanical, and structural properties: implications for elevated

  5. Accuracy of serial myocardial perfusion scintigraphy with /sup 201/Tl for prediction of graft patency early and late after coronary artery bypass surgery. A controlled prospective study

    SciTech Connect

    Pfisterer, M.; Emmenegger, H.; Schmitt, H.E.; Mueller-Brand, J.; Hasse, J.; Graedel, E.; Laver, M.B.; Burckhardt, D.; Burkart, F.

    1982-11-01

    To assess the accuracy of serial myocardial perfusion scintigraphy with /sup 201/Tl to predict graft patency early and late coronary artery bypass surgery, rest and exercise /sup 201/Tl and coronary arteriography were performed preoperatively and 2 weeks and 1 year after operation. The scintigraphic results were compared with graft patency, symptoms, left ventricular function and physical work capacity in a consecutive series of 55 patients with a total of 154 grafts. Serial /sup 201/Tl had an 80% sensitivity, 88% specificity and 86% overall accuracy in detecting or excluding graft occlusion, which was predicted by reversible ischemia as well as persistent new scar segments. Occluded grafts were correctly localized by /sup 201/Tl scintigraphy in 61%. Postoperative apical /sup 201/Tl defects were frequent (two-thirds of cases), and were the result of intraoperative transapical venting of the left ventricle. After coronary bypass graft surgery, ejection fraction at rest was unchanged. Left ventricular end-diastolic pressure and physical work capacity improved significantly. In the presence of new perfusion defects detected postoperatively, physical work capacity was reduced significantly. New /sup 201/Tl defects in addition to typical or atypical angina provided a high probability of graft occlusion, while in the absence of new /sup 201/Tl defects all grafts were patent in more than 90% of patients, all of whom had no or only atypical chest pain. We conclude that serial /sup 201/Tl imaging after coronary artery bypass surgery is an accurate noninvasive method that can be used routinely to assess graft function, to localize spatially occluded grafts and to identify patients with a high likelihood of graft occlusion who may need invasive studies.

  6. Myocardial perfusion cardiac magnetic resonance for the diagnosis of coronary artery disease: do we need rest images?

    PubMed

    Krittayaphong, Rungroj; Boonyasirinant, Thananya; Saiviroonporn, Pairash; Nakyen, Supaporn; Thanapiboonpol, Prajak; Yindeengam, Ahthit; Udompunturak, Suthipol

    2009-04-01

    Adenosine stress cardiovascular magnetic resonance (CMR) has been reported to be useful for the diagnosis of coronary artery disease (CAD). Most studies use rest and stress perfusion images. The objectives of this study were to determine (Barkhausen et al. in J Magn Reson Imaging 19(6):750-757, 1) the accuracy of visual assessment and myocardial perfusion reserve index (MPRI) in the diagnosis of CAD and (Rieber et al. in Fur Heart J 27(12):1465-1471, 2) the accuracy of analysis based on rest-stress and stress images. We enrolled patients with suspected CAD and referred them for coronary angiography (CAG). All the patients underwent adenosine stress CMR before CAG. Rest and stress perfusion images were analyzed by calculation of MPRI and visual assessment separately. Visual assessment was performed separately by using rest and stress images and by using only stress images. CAG was considered the gold standard. Sensitivity, specificity, and accuracy of both methods were calculated and compared. A total of 66 patients (mean age, 61.3 +/- 11.7 years) were studied. Thirty-eight patients (57.6%) were diagnosed with CAD. The sensitivity and specificity for the diagnosis of CAD (> or =50% stenosis) were 89.5 and 78.6% for MPRI, 76.3 and 75% for stress-rest visual method, and 86.8 and 75% for stress visual method, respectively. CMR perfusion had a relatively lower accuracy in patients with left ventricular systolic dysfunction, high left ventricular mass, or presence of late gadolinium enhancement than in patients without those CMR findings. Visual assessment of stress image of CMR perfusion is accurate and comparable to MPRI for the detection of CAD.

  7. Arterial microanastomoses on the reverse flow of the internal carotid artery reverse flow: an extreme solution in free-flap revascularisation. How we do it.

    PubMed

    Baj, A; Bolzoni, A; Torretta, S; Pignataro, L

    2014-10-01

    Microvascular free tissue transfer in head and neck reconstruction requires suitable recipient vessels, which are frequently compromised by prior surgery, radiotherapy, or size of the tumour. A surgical description of an arterial free flap pedicle anastomosis on the reverse internal carotid arterial flow in a vessel-depleted neck is presented. A 66-year-old male with a relapse of hypopharyngeal squamous cell carcinoma previously treated with both surgical and radiation therapy for carcinoma of the tongue and the larynx was successfully reconstructed using a free forearm flap with reverse internal carotid arterial flow. The involvement of the carotid glomus and prior surgery excluded the other vessels as recipients. The forearm free flap survived without any complications. This procedure can be considered an alternative rescue technique for salvage reconstruction in a vessel-depleted neck.

  8. Acute Effects of Lateral Thigh Foam Rolling on Arterial Tissue Perfusion Determined by Spectral Doppler and Power Doppler Ultrasound.

    PubMed

    Hotfiel, Thilo; Swoboda, Bernd; Krinner, Sebastian; Grim, Casper; Engelhardt, Martin; Uder, Michael; Heiss, Rafael U

    2017-04-01

    Hotfiel, T, Swoboda, B, Krinner, S, Grim, C, Engelhardt, M, Uder, M, and Heiss, R. Acute effects of lateral thigh foam rolling on arterial tissue perfusion determined by spectral Doppler and power Doppler ultrasound. J Strength Cond Res 31(4): 893-900, 2017-Foam rolling has been developed as a popular intervention in training and rehabilitation. However, evidence on its effects on the cellular and physiological level is lacking. The aim of this study was to assess the effect of foam rolling on arterial blood flow of the lateral thigh. Twenty-one healthy participants (age, 25 ± 2 years; height, 177 ± 9 cm; body weight, 74 ± 9 kg) were recruited from the medical and sports faculty. Arterial tissue perfusion was determined by spectral Doppler and power Doppler ultrasound, represented as peak flow (Vmax), time average velocity maximum (TAMx), time average velocity mean (TAMn), and resistive index (RI), and with semiquantitative grading that was assessed by 4 blindfolded investigators. Measurement values were assessed under resting conditions and twice after foam rolling exercises of the lateral thigh (0 and 30 minutes after intervention). The trochanteric region, mid portion, and distal tibial insertion of the lateral thigh were representative for data analysis. Arterial blood flow of the lateral thigh increased significantly after foam rolling exercises compared with baseline (p ≤ 0.05). We detected a relative increase in Vmax of 73.6% (0 minutes) and 52.7% (30 minutes) (p < 0.001), in TAMx of 53.2% (p < 0.001) and 38.3% (p = 0.002), and in TAMn of 84.4% (p < 0.001) and 68.2% (p < 0.001). Semiquantitative power Doppler scores at all portions revealed increased average grading of 1.96 after intervention and 2.04 after 30 minutes compared with 0.75 at baseline. Our results may contribute to the understanding of local physiological reactions to self-myofascial release.

  9. Value of thallium-201 reinjection after delayed SPECT imaging for predicting reversible ischemia after coronary artery bypass grafting

    SciTech Connect

    Ohtani, H.; Tamaki, N.; Yonekura, Y.; Mohiuddin, I.H.; Hirata, K.; Ban, T.; Konishi, J. )

    1990-08-15

    The reinjection of a small dose (40 MBq) of thallium-201 after stress and delayed imaging often shows new redistribution in the regions with persistent defect. To assess whether these segments may represent reversible ischemia, reinjection thallium-201 single-photon emission computed tomography (SPECT) was performed after stress and 3-hour delayed imaging in 24 patients before coronary artery bypass grafting (CABG). The left ventricular myocardium was divided into 5 myocardial segments and regional wall motion was scored on a scale from 0 (normal) to 4 (dyskinesia). Thallium-201 findings were compared with improvement in regional perfusion and wall motion 1 to 2 months after CABG. The reinjection imaging identified new redistribution in 15 of 32 persistent defects (47%) on the 3-hour delayed images. In the study of stress and delayed SPECT imaging, the improvement in perfusion was observed in 34 of 43 segments (79%) exhibiting redistribution and 15 of 32 (47%) segments without redistribution (p less than 0.01). The reinjection SPECT identified new redistribution in 12 of the 15 improved segments that were not detected on the delayed images. Similarly, the improvement in wall motion was observed in 23 of 31 segments (74%) exhibiting redistribution and 14 of 30 segments (47%) without redistribution on the delayed images (p less than 0.05). The reinjection identified new redistribution in 10 of the 14 improved segments that were undetected on the delayed images. The predictive values for improvement in perfusion and wall motion by the reinjection imaging were significantly higher (92 and 89%) than those by the delayed imaging (69 and 62%, respectively, p less than 0.05 each).

  10. Intrinsic chemosensitivity of rostral ventrolateral medullary sympathetic premotor neurons in the in situ arterially perfused preparation of rats.

    PubMed

    Koganezawa, Tadachika; Paton, Julian F R

    2014-11-01

    Brainstem hypoperfusion is a major excitant of sympathetic activity triggering hypertension, but the exact mechanisms involved remain incompletely understood. A major source of excitatory drive to preganglionic sympathetic neurons originates from the ongoing activity of premotor neurons in the rostral ventrolateral medulla (RVLM sympathetic premotor neurons). The chemosensitivity profile of physiologically characterized RVLM sympathetic premotor neurons during hypoxia and hypercapnia remains unclear. We examined whether physiologically characterized RVLM sympathetic premotor neurons can sense brainstem ischaemia intrinsically. We addressed this issue in a unique in situ arterially perfused preparation before and after a complete blockade of fast excitatory and inhibitory synaptic transmission. During hypercapnic hypoxia, respiratory modulation of RVLM sympathetic premotor neurons was lost, but tonic firing of most RVLM sympathetic premotor neurons was elevated. After blockade of fast excitatory and inhibitory synaptic transmission, RVLM sympathetic premotor neurons continued to fire and exhibited an excitatory firing response to hypoxia but not hypercapnia. This study suggests that RVLM sympathetic premotor neurons can sustain high levels of neuronal discharge when oxygen is scarce. The intrinsic ability of RVLM sympathetic premotor neurons to maintain responsivity to brainstem hypoxia is an important mechanism ensuring adequate arterial pressure, essential for maintaining cerebral perfusion in the face of depressed ventilation and/or high cerebral vascular resistance.

  11. Deriving the Intrahepatic Arteriovenous Shunt Rate from CT Images and Biochemical Data Instead of from Arterial Perfusion Scintigraphy in Hepatic Arterial Infusion Chemotherapy

    SciTech Connect

    Ozaki, Toshiro Seki, Hiroshi; Shiina, Makoto

    2009-09-15

    The purpose of the present study was to elucidate a method for predicting the intrahepatic arteriovenous shunt rate from computed tomography (CT) images and biochemical data, instead of from arterial perfusion scintigraphy, because adverse exacerbated systemic effects may be induced in cases where a high shunt rate exists. CT and arterial perfusion scintigraphy were performed in patients with liver metastases from gastric or colorectal cancer. Biochemical data and tumor marker levels of 33 enrolled patients were measured. The results were statistically verified by multiple regression analysis. The total metastatic hepatic tumor volume (V{sub metastasized}), residual hepatic parenchyma volume (V{sub residual}; calculated from CT images), and biochemical data were treated as independent variables; the intrahepatic arteriovenous (IHAV) shunt rate (calculated from scintigraphy) was treated as a dependent variable. The IHAV shunt rate was 15.1 {+-} 11.9%. Based on the correlation matrixes, the best correlation coefficient of 0.84 was established between the IHAV shunt rate and V{sub metastasized} (p < 0.01). In the multiple regression analysis with the IHAV shunt rate as the dependent variable, the coefficient of determination (R{sup 2}) was 0.75, which was significant at the 0.1% level with two significant independent variables (V{sub metastasized} and V{sub residual}). The standardized regression coefficients ({beta}) of V{sub metastasized} and V{sub residual} were significant at the 0.1 and 5% levels, respectively. Based on this result, we can obtain a predicted value of IHAV shunt rate (p < 0.001) using CT images. When a high shunt rate was predicted, beneficial and consistent clinical monitoring can be initiated in, for example, hepatic arterial infusion chemotherapy.

  12. Complementary Prognostic Values of Stress Myocardial Perfusion and Late Gadolinium Enhancement Imaging by Cardiac Magnetic Resonance in Patients with Known or Suspected Coronary Artery Disease

    PubMed Central

    Steel, Kevin; Broderick, Ryan; Gandla, Vijay; Larose, Eric; Resnic, Frederick; Jerosch-Herold, Michael; Brown, Kenneth A.; Kwong, Raymond Y.

    2009-01-01

    BACKGROUND Recent studies have demonstrated the significant prognostic value of stress CMR myocardial perfusion imaging (CMRMPI). Apart from characterizing reversible perfusion defect (RevPD) from flow-limiting coronary stenosis, CMR late enhancement imaging (LGE) is currently the most sensitive method in detecting subendocardial infarction (MI). We therefore tested the hypothesis that, characterization of these 2 processes from coronary artery disease (CAD) by CMR can provide complementary prognostic values. Methods and Results We performed CMRMPI followed by LGE imaging on 254 patients referred with symptoms of myocardial ischemia. At a median follow up of 17 months, 49 cardiac events (MACE) occurred including 12 cardiac deaths, 16 acute myocardial infarction (MI), and 21 cardiac hospitalizations. RevPD and LGE both maintained a > 3-fold association with cardiac death or acute MI (Death/MI) when adjusted to each other and to the effects of patient age and gender (adjusted HR 3.31, P=0.02 and 3.43, P=0.01, respectively). In patients without a history of MI who had negative RevPD, LGE presence was associated with >11-fold hazards increase to Death/MI. Patients with neither RevPD nor LGE had a 98.1% negative annual event rate for Death/MI. For association with MACE, RevPD was the strongest multivariable variable in the best overall model (HR 10.92, P<0.0001). Conclusions CMR imaging provides robust risk-stratification of patients who presents with symptoms of ischemia. Characterization of RevPD and LGE by CMR provides strong and complementary prognostic implication towards cardiac death or acute MI. PMID:19770399

  13. Reversibility of intrapulmonary arteriovenous shunts in liver cirrhosis documented by serial radionuclide perfusion lung scans

    SciTech Connect

    Chen, N.S.; Barnett, C.A.; Farrer, P.A.

    1984-05-01

    Using serial perfusion lung scans, the opening up and closure of right-to-left intrapulmonary arteriovenous shunts has been documented over a period of several weeks in a patient with chronic alcoholic liver disease. The presence of the shunts correlates well with the severity of hypoxemia and the presence of nodular mottling on chest radiographs. The time course of these changes with clinical status suggests lability and the functional nature of these shunts.

  14. Evaluation of patients with coronary artery disease during exercise: the relation between extent of disease and perfusion deficit.

    PubMed

    Hakki, A H; DePace, N; Iskandrian, A S

    1984-01-01

    The purpose of this study was to assess the relation between the extent of coronary artery disease (CAD) and size of exercise-induced myocardial hypoperfusion in 79 patients with angiographically documented CAD. None of the patients had Q-wave myocardial infarction. Fifty patients had one-vessel disease, ten had two-vessel disease, and 19 patients had three-vessel or left main disease. From a scintigraphic functional standpoint, patients were classified into two groups: 28 patients (35%) had large perfusion defects and 51 patients (65%) had small defects. The size of the thallium-201 perfusion defect during exercise was assessed as the perimeter of the defect in each projection expressed as a percentage abnormality of the total left ventricular perimeter in that projection. The average abnormality from the three projections was used in the final analysis. Eleven patients with large defects (39%) had one-vessel disease and 12 patients with small defects (24%) had multivessel disease. Stepwise multivariate discriminate analysis identified the number of diseased vessels (F = 13.9), the change in systolic blood pressure from rest to exercise (F = 10.8), the exercise heart rate (F = 9.1), and exercise electrocardiographic response (F = 7.8) as significant associates of the size of the perfusion defect (predictive accuracy = 70%). We conclude that the size of hypoperfused myocardium during exercise is variable in patients with CAD. Discriminate analysis identified the extent of CAD, exercise heart rate, change in systolic pressure from rest to exercise, and exercise electrocardiographic response as significant associates of the size of the defect.

  15. The attention network changes in breast cancer patients receiving neoadjuvant chemotherapy: Evidence from an arterial spin labeling perfusion study

    PubMed Central

    Chen, Xingui; He, Xiaoxuan; Tao, Longxiang; Cheng, Huaidong; Li, Jingjing; Zhang, Jingjie; Qiu, Bensheng; Yu, Yongqiang; Wang, Kai

    2017-01-01

    To investigate the neural mechanisms underlying attention deficits that are related to neoadjuvant chemotherapy in combination with cerebral perfusion. Thirty one patients with breast cancer who were scheduled to receive neoadjuvant chemotherapy and 34 healthy control subjects were included. The patients completed two assessments of the attention network tasks (ANT), neuropsychological background tests, and the arterial spin labeling scan, which were performed before neoadjuvant chemotherapy and after completing chemotherapy. After neoadjuvant chemotherapy, the patients exhibited reduced performance in the alerting and executive control attention networks but not the orienting network (p < 0.05) and showed significant increases in cerebral blood flow (CBF) in the left posterior cingulate gyrus, left middle occipital gyrus, bilateral precentral gyrus, inferior parietal gyrus, supramarginal gyrus, angular gyrus, precuneus, cuneus, superior occipital gyrus, calcarine cortex, and temporal gyrus (p < 0.01 corrected) when compared with patients before chemotherapy and healthy controls. A significant correlation was found between the decrease performance of ANT and the increase in CBF changes in some brain regions of the patients with breast cancer. The results demonstrated that neoadjuvant chemotherapy influences hemodynamic activity in different brain areas through increasing cerebral perfusion, which reduces the attention abilities in breast cancer patients. PMID:28209975

  16. A pilot study on diagnosis of coronary artery disease using computed tomography first-pass myocardial perfusion imaging at rest

    PubMed Central

    Wang, Qi; Qin, Jing; Gai, Lu-yue; Chen, Yun-dai; Dong, Wei; Guan, Zhi-wei; Wang, Zhi-guo; Sun, Zhi-jun; Tian, Jia-he

    2011-01-01

    Background: Although computed tomography coronary angiography (CTCA) can identify coronary stenosis, little data exists on the ability of multislice computed tomography (MSCT) to detect myocardial perfusion defects at rest. Methods: In 33 patients with diagnosed or suspected coronary artery disease (CAD), CTCA using retrospective electrocardiography (ECG) gating at rest and invasive coronary angiography (ICA) was performed. The 2D myocardial images were reconstructed in diastolic and systolic phases using the same raw data for CTCA. CT values of the myocardium were used as an estimate of myocardial enhancement, which were shown by color mapping. Myocardial ischemia was defined as a pattern of transient endocardial hypo-enhancement at systole and normal enhancement at diastole. The results of ICA were taken as the reference standard. Results: When a diameter reduction of more than 50% in ICA was used as diagnostic criteria of CAD, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CT first-pass myocardial perfusion imaging (MPI) at rest were 0.85, 0.67, 0.92, and 0.50 per patient, respectively, and 0.58, 0.93, 0.85, and 0.76 per vessel, respectively. Conclusions: CT first-pass MPI at rest could detect CAD patients, which could become a practical and convenient way to detect ischemia, consequently offering the ability for MSCT to act as a “one stop shop” for the diagnosis of CAD. PMID:21634042

  17. Sonographic parenchymal and brain perfusion imaging: preliminary results in four patients following decompressive surgery for malignant middle cerebral artery infarct.

    PubMed

    Schlachetzki, F; Hoelscher, T; Dorenbeck, U; Greiffenberg, B; Marienhagen, J; Ullrich, O W; Bogdahn, U

    2001-01-01

    To investigate new methods of diagnostic transcranial sonography for brain parenchymal, vascular and perfusion imaging, we performed 3-D native tissue harmonic transcranial sonography (3D-nthTCS), 3-D transcranial color-coded duplex sonography (3D-TCCS), and "loss-of-correlation" imaging (LOC-TCCS) in four patients following early hemicraniectomy due to space-occupying "malignant" middle cerebral artery infarction (MMCAI). Three-dimensional datasets, utilizing 3D-nthTCS and 3D-TCCS, were created and up to 10 axial 2-D B-mode image planes, similar to CCT, reconstructed in each patient. Three-dimensional reconstructions of the circle of Willis documented one persistent carotid-T occlusion and three recanalizations of the MCA. LOC-TCCS, based on stimulated acoustic emission from an ultrasound (US) contrast agent, demonstrated a perfusion deficit in 2 of 3 patients, with regard to their infarcts. Concluding, 3D-nthTCS, 3D-TCCS and LOC-TCCS are promising tools for bedside monitoring, early prognosis and treatment evaluation for MMCAI in the postoperative period. Further studies should be performed to standardize these new methods and evaluate their applications through the intact calvarina.

  18. The relationship between exercise-induced muscle fatigue, arterial blood flow and muscle perfusion after 56 days local muscle unloading.

    PubMed

    Weber, Tobias; Ducos, Michel; Mulder, Edwin; Beijer, Åsa; Herrera, Frankyn; Zange, Jochen; Degens, Hans; Bloch, Wilhelm; Rittweger, Jörn

    2014-05-01

    In the light of the dynamic nature of habitual plantar flexor activity, we utilized an incremental isokinetic exercise test (IIET) to assess the work-related power deficit (WoRPD) as a measure for exercise-induced muscle fatigue before and after prolonged calf muscle unloading and in relation to arterial blood flow and muscle perfusion. Eleven male subjects (31 ± 6 years) wore the HEPHAISTOS unloading orthosis unilaterally for 56 days. It allows habitual ambulation while greatly reducing plantar flexor activity and torque production. Endpoint measurements encompassed arterial blood flow, measured in the femoral artery using Doppler ultrasound, oxygenation of the soleus muscle assessed by near-infrared spectroscopy, lactate concentrations determined in capillary blood and muscle activity using soleus muscle surface electromyography. Furthermore, soleus muscle biopsies were taken to investigate morphological muscle changes. After the intervention, maximal isokinetic torque was reduced by 23·4 ± 8·2% (P<0·001) and soleus fibre size was reduced by 8·5 ± 13% (P = 0·016). However, WoRPD remained unaffected as indicated by an unchanged loss of relative plantar flexor power between pre- and postexperiments (P = 0·88). Blood flow, tissue oxygenation, lactate concentrations and EMG median frequency kinematics during the exercise test were comparable before and after the intervention, whereas the increase of RMS in response to IIET was less following the intervention (P = 0·03). In conclusion, following submaximal isokinetic muscle work exercise-induced muscle fatigue is unaffected after prolonged local muscle unloading. The observation that arterial blood flow was maintained may underlie the unchanged fatigability.

  19. Liver cancer arterial perfusion modelling and CFD boundary conditions methodology: a case study of the haemodynamics of a patient-specific hepatic artery in literature-based healthy and tumour-bearing liver scenarios.

    PubMed

    Aramburu, Jorge; Antón, Raúl; Rivas, Alejandro; Ramos, Juan Carlos; Sangro, Bruno; Bilbao, José Ignacio

    2016-11-01

    Some of the latest treatments for unresectable liver malignancies (primary or metastatic tumours), which include bland embolisation, chemoembolisation, and radioembolisation, among others, take advantage of the increased arterial blood supply to the tumours to locally attack them. A better understanding of the factors that influence this transport may help improve the therapeutic procedures by taking advantage of flow patterns or by designing catheters and infusion systems that result in the injected beads having increased access to the tumour vasculature. Computational analyses may help understand the haemodynamic patterns and embolic-microsphere transport through the hepatic arteries. In addition, physiological inflow and outflow boundary conditions are essential in order to reliably represent the blood flow through arteries. This study presents a liver cancer arterial perfusion model based on a literature review and derives boundary conditions for tumour-bearing liver-feeding hepatic arteries based on the arterial perfusion characteristics of normal and tumorous liver segment tissue masses and the hepatic artery branching configuration. Literature-based healthy and tumour-bearing realistic scenarios are created and haemodynamically analysed for the same patient-specific hepatic artery. As a result, this study provides boundary conditions for computational fluid dynamics simulations that will allow researchers to numerically study, for example, various intravascular devices used for liver disease intra-arterial treatments with different cancer scenarios. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Tissue-Muscle Perfusion Scintigraphy of the Lower Limbs in a Patient with Type 2 Diabetes Mellitus and Peripheral Arterial Disease

    PubMed Central

    Manevska, Nevena; Gjorceva, Daniela Pop; Ahmeti, Irfan; Todorovska, Lidija; Stojanoski, Sinisa; Kocovska, Marina Zdraveska

    2016-01-01

    The estimation of tissue perfusion as a hemodynamic consequence of peripheral arterial disease (PAD) in diabetic patients is of great importance in the management of these patients.We present a noninvasive, functional method of 99mTc-MIBI (methoxy-isobutyl-isonitrile) tissue-muscle perfusion scintigraphy (TMPS) of the lower limbs, which assesses tissue perfusion in basal conditions (“rest” study) and exercise conditions (“stress” study). Emphasis is given on perfusion reserve (PR) as an important indicator of preservation of microcirculation and its local autoregulatory mechanisms in PAD. We present a case of a 71-year-old male diabetic patient with skin ulcers of the right foot and an ankle-brachial index >1.2 (0.9-1.1). Dynamic phase TMPS of the lower limbs showed decreased and late arterial vascularization of the right calf (RC) with lower percentage of radioactivity in the 1st minute: RC 66%, left calf (LC) 84%. PR was borderline with a value of 57% for LC and decreased for RC (42%). Functional assessment of hemodynamic consequences of PAD is important in evaluating both advanced and early PAD, especially the asymptomatic form. The method used to determine the TMPS of the lower limbs, can differentiate subtle changes in microcirculation and tissue perfusion. PMID:27299288

  1. Predicting Cerebral Hyperperfusion Syndrome Following Superficial Temporal Artery to Middle Cerebral Artery Bypass based on Intraoperative Perfusion-Weighted Magnetic Resonance Imaging.

    PubMed

    Wang, Defeng; Zhu, Fengping; Fung, Ka Ming; Zhu, Wei; Luo, Yishan; Chu, Winnie Chiu Wing; Mok, Vincent Chung Tong; Wu, Jinsong; Shi, Lin; Ahuja, Anil T; Mao, Ying

    2015-09-14

    Moyamoya disease leads to the formation of stenosis in the cerebrovasculature. A superficial temporal artery to middle cerebral artery (STA-MCA) bypass is an effective treatment for the disease, yet it is usually associated with postoperative cerebral hyperperfusion syndrome (CHS). This study aimed to evaluate cerebral hemodynamic changes immediately after surgery and assess whether a semiquantitative analysis of an intraoperative magnetic resonance perfusion-weighted image (PWI) is useful for predicting postoperative CHS. Fourteen patients who underwent the STA-MCA bypass surgery were included in this study. An atlas-based registration method was employed for studying hemodynamics in different cerebral regions. Pre- versus intraoperative and group-wise comparisons were conducted to evaluate the hemodynamic changes. A postoperative increase in relative cerebral blood flow (CBF) at the terminal MCA territory (P = 0.035) and drop in relative mean-time-transit at the central MCA territory (P = 0.012) were observed in all patients. However, a significant raise in the increasing ratio of relative-CBF at the terminal MCA territory was only found in CHS patients (P = 0.023). The cerebrovascular changes of the patients after revascularization treatment were confirmed. Intraoperative PWI might be helpful in predicting the change in relative-CBF at MCA terminal territory which might indicate a risk of CHS.

  2. Sequential thallium-201 myocardial perfusion studies after successful percutaneous transluminal coronary artery angioplasty: delayed resolution of exercise-induced scintigraphic abnormalities

    SciTech Connect

    Manyari, D.E.; Knudtson, M.; Kloiber, R.; Roth, D.

    1988-01-01

    To characterize the sequential changes of myocardial perfusion scintigraphy in patients with coronary artery disease (CAD) after complete revascularization, 43 patients underwent exercise thallium-201 (/sup 201/Tl) myocardial perfusion scintigraphy before and at 9 +/- 5 days, 3.3 +/- 0.6, and 6.8 +/- 1.2 months after percutaneous transluminal coronary angioplasty (PTCA). Only patients with single-vessel CAD, without previous myocardial infarction, and without evidence of restenosis at 6 to 9 months after PTCA were included. Perfusion scans were analyzed blindly with the use of a new quantitative method to define regional myocardial perfusion in the topographic distribution of each coronary artery, which was shown to be reproducible (r = .94 or higher and SEE of 7% or less, between repeated measures by one and two operators). At 4 to 18 days after PTCA, the mean treadmill walking time increased by 123 +/- 42 sec, mean exercise-induced ST segment depression decreased by 0.6 +/- 0.3 mm, group maximal heart rate increased by 20 +/- 9 beats/min, and group systolic blood pressure at peak exercise increased by 24 +/- 10 mm Hg, compared with pre-PTCA values (p less than .001). However, no group differences were noted in these variables between the three post-PTCA stages. Myocardial perfusion in the distribution of the affected (dilated) coronary artery, on the other hand, improved progressively. In the 45 degree left anterior oblique view for instance, myocardial perfusion increased at 9 days after PTCA (from 68 +/- 24% before PTCA to 91 +/- 9%, p less than .001) and at 3.3 months after PTCA (101 +/- 8%, p less than .05 vs 9 days after PTCA), but no further significant changes were seen at 6.8 months after PTCA (102 +/- 8%). Similar changes were noted in the other two views. No relationship between minor complications during PTCA and delayed improvement on the /sup 201/Tl was observed.

  3. Influence of a radiographic contrast media (Iopentol) with different viscosities on capillary perfusion in patients with coronary artery disease.

    PubMed

    Jung, F; Mrowietz, C; Gerk, U; Franke, R P

    2013-01-01

    Radiographic contrast media (RCM) are widely used to visualize blood vessels. Their effects on blood vessels should be minimal so that the object of the measurement - the vessel lumen - is not influenced by the RCM molecules. However, all RCMs exhibit a more or less strong effect on endothelial cells as well as on erythrocytes. These effects are discussed to induce a significant and relevant deceleration of the microcirculation. For some RCMs this could be demonstrated in animal or clinical studies. Therefore, this study investigated the role of the viscosity of a RCM on the mean erythrocyte velocity in nail fold capillaries in patients with coronary artery disease after a bolus injection of the RCM directly into the A. axillaris. Iopentol-350 is a high-viscous Xray contrast medium and induced a short-lasting imbalance of the microcirculation already in vascular regions not affected by atherosclerosis. This effect was - in the early phase after injection - significantly stronger than after application of the low viscous Iopentol-150. In patients with severe coronary artery disease and a myocardial perfusion at its limits, the injection of high-viscous X-ray contrast media could induce massive perturbations in the microcirculation and even ischemia. As a consequence a further impairment of both systolic and diastolic functions may occur.

  4. Spreading dilatation to luminal perfusion of ATP and UTP in rat isolated small mesenteric arteries

    PubMed Central

    Winter, Polly; Dora, Kim A

    2007-01-01

    Levels of ATP achieved within the lumen of vessels suggest a key autacoid role. P2Y receptors on the endothelium may represent the target for ATP, leading to hyperpolarization and associated relaxation of vascular smooth muscle through the endothelium-dependent hyperpolarizing factor (EDHF) pathway. EDHF signals radially from the endothelium to cause dilatation, and appears mechanistically distinct from the axial spread of dilatation, which we showed occurs independently of a change in endothelial cell Ca2+ in rat mesenteric arteries. Here we have investigated the potential of P2Y receptor stimulation to evoke spreading dilatation in rat resistance small arteries under physiological pressure and flow. Triple cannulation of isolated arteries enables focal application of purine and pyrimidine nucleotides to the endothelium, avoiding potential complicating actions of these agents on the smooth muscle. Nucleotides were locally infused through one branch of a bifurcation, causing near maximal local dilatation attributable to EDHF. Dilatation then spread rapidly into the adjacent feed artery and upstream against the direction of luminal flow, sufficient to increase flow into the feed artery. The rate of decay of this spreading dilatation was identical between nucleotides, and matched that to ACh, which acts only on the endothelium. In contrast, focal abluminal application of either ATP or UTP at the downstream end of cannulated arteries evoked constriction, which only in the case of ATP was also associated with modest spread of dilatation. The non-hydrolysable ADP analogue, ADPβS, acting at P2Y1 receptors, caused robust local and spreading dilatation responses whether applied to the luminal or abluminal surface of pressurized arteries. Dilatation to nucleotides was sensitive to inhibition with apamin and TRAM-34, selective blockers of small- and intermediate-conductance Ca2+-activated K+ channels, respectively. These data demonstrate that direct luminal stimulation of P

  5. An arterially perfused nose-olfactory bulb preparation of the rat.

    PubMed

    Pérez de los Cobos Pallarés, Fernando; Stanić, Davor; Farmer, David; Dutschmann, Mathias; Egger, Veronica

    2015-09-01

    A main feature of the mammalian olfactory bulb network is the presence of various rhythmic activities, in particular, gamma, beta, and theta oscillations, with the latter coupled to the respiratory rhythm. Interactions between those oscillations as well as the spatial distribution of network activation are likely to determine olfactory coding. Here, we describe a novel semi-intact perfused nose-olfactory bulb-brain stem preparation in rats with both a preserved olfactory epithelium and brain stem, which could be particularly suitable for the study of oscillatory activity and spatial odor mapping within the olfactory bulb, in particular, in hitherto inaccessible locations. In the perfused olfactory bulb, we observed robust spontaneous oscillations, mostly in the theta range. Odor application resulted in an increase in oscillatory power in higher frequency ranges, stimulus-locked local field potentials, and excitation or inhibition of individual bulbar neurons, similar to odor responses reported from in vivo recordings. Thus our method constitutes the first viable in situ preparation of a mammalian system that uses airborne odor stimuli and preserves these characteristic features of odor processing. This preparation will allow the use of highly invasive experimental procedures and the application of techniques such as patch-clamp recording, high-resolution imaging, and optogenetics within the entire olfactory bulb.

  6. Reversible cerebral vasoconstriction syndrome with multivessel cervical artery dissections and a double aortic arch.

    PubMed

    Nouh, Amre; Ruland, Sean; Schneck, Michael J; Pasquale, David; Biller, José

    2014-02-01

    Reversible cerebral vasoconstriction syndrome (RCVS) has been associated with exposure to vasoactive substances and few reports with cervical arterial dissections (CADs). We evaluated a 32-year-old woman with history of depression, migraines without aura, and cannabis use who presented with a thunderclap headache unresponsive to triptans. She was found to have bilateral occipital infarcts, bilateral extracranial vertebral artery dissections, bilateral internal carotid artery dissecting aneurysms, and extensive distal multifocal segmental narrowing of the anterior and posterior intracranial circulation with a "sausage on a string-like appearance" suggestive of RCVS. Subsequently, she was found to have a distal thrombus of the basilar artery, was anticoagulated, and discharged home with no residual deficits. We highlight the potential association of CADs and RCVS. The association of RCVS and a double aortic arch has not been previously reported.

  7. Selective renal vasodilation and active renal artery perfusion improve renal function in dogs with acute heart failure.

    PubMed

    Suehiro, K; Shimizu, J; Yi, G H; Gu, A; Wang, J; Keren, G; Burkhoff, D

    2001-09-01

    Renal failure is common in heart failure due to renovascular constriction and hypotension. We tested whether selective pharmacological renal artery vasodilation and active renal artery perfusion (ARP) could improve renal function without adverse effects on systemic blood pressure in a canine model of acute heart failure (AHF). AHF was induced by coronary microembolization in 16 adult mongrel dogs. In five dogs, selective intrarenal (IR) papaverine (1, 2, and 4 mg/min) was administered into the left renal artery. In six dogs, ARP was performed in the left renal artery to normalize mean renal arterial pressure followed by administration of IR papaverine (2 mg/min). In five dogs, ARP plus intravenous furosemide was tested. Urine output (UO) and cortical renal blood flow decreased during AHF and were restored by 2 mg/min IR papaverine (UO: baseline 4.2 +/- 0.6, AHF 1.6 +/- 1.3, IR papaverine 5.8 +/- 1.1 ml/15 min; cortical blood flow: baseline 4.3 +/- 0.2, AHF 2.4 +/- 0.6, IR papaverine 4.2 +/- 1.2 ml/min/g) with no significant change in aortic pressure. ARP also increased urine output and cortical renal blood flow (UO: baseline 5.0 +/- 1.1, AHF 0.5 +/- 0.4, ARP 3.8 +/- 3.1 ml/15 min; cortical blood flow: baseline 4.0 +/- 0.5, AHF 2.0 +/- 0.8, ARP 3.52 +/- 1.1 ml/min/g). A combination of these methods in AHF further increased urine output to twice the normal baseline (10.5 +/- 7.5 ml/15 min). Addition of furosemide synergistically increased UO above that achieved with ARP alone (5.5 +/- 2.6 versus 40.3 +/- 24.7 ml/15 min, p = 0.03). In conclusion, ARP and selective renal vasodilation may effectively promote salt and water excretion in the setting of heart failure, particularly when systemic blood pressure is low.

  8. Pulmonary arterial hypertension: an imaging review comparing MR pulmonary angiography and perfusion with multidetector CT angiography.

    PubMed

    Junqueira, F P; Lima, C M A O; Coutinho, A C; Parente, D B; Bittencourt, L K; Bessa, L G P; Domingues, R C; Marchiori, E

    2012-11-01

    Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH.

  9. Pulmonary arterial hypertension: an imaging review comparing MR pulmonary angiography and perfusion with multidetector CT angiography

    PubMed Central

    Junqueira, F P; Lima, C M A O; Coutinho, A C; Parente, D B; Bittencourt, L K; Bessa, L G P; Domingues, R C; Marchiori, E

    2012-01-01

    Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH. PMID:22932061

  10. Resting cerebral blood flow alterations in chronic traumatic brain injury: an arterial spin labeling perfusion FMRI study.

    PubMed

    Kim, Junghoon; Whyte, John; Patel, Sunil; Avants, Brian; Europa, Eduardo; Wang, Jiongjiong; Slattery, John; Gee, James C; Coslett, H Branch; Detre, John A

    2010-08-01

    Non-invasive measurement of resting state cerebral blood flow (CBF) may reflect alterations of brain structure and function after traumatic brain injury (TBI). However, previous imaging studies of resting state brain in chronic TBI have been limited by several factors, including measurement in relative rather than absolute units, use of crude spatial registration methods, exclusion of subjects with substantial focal lesions, and exposure to ionizing radiation, which limits repeated assessments. This study aimed to overcome those obstacles by measuring absolute CBF with an arterial spin labeling perfusion fMRI technique, and using an image preprocessing protocol that is optimized for brains with mixed diffuse and focal injuries characteristic of moderate and severe TBI. Resting state CBF was quantified in 27 individuals with moderate to severe TBI in the chronic stage, and 22 demographically matched healthy controls. In addition to global CBF reductions in the TBI subjects, more prominent regional hypoperfusion was found in the posterior cingulate cortices, the thalami, and multiple locations in the frontal cortices. Diffuse injury, as assessed by tensor-based morphometry, was mainly associated with reduced CBF in the posterior cingulate cortices and the thalami, where the greatest volume losses were detected. Hypoperfusion in superior and middle frontal cortices, in contrast, was associated with focal lesions. These results suggest that structural lesions, both focal and diffuse, are the main contributors to the absolute CBF alterations seen in chronic TBI, and that CBF may serve as a tool to assess functioning neuronal volume. We also speculate that resting reductions in posterior cingulate perfusion may reflect alterations in the default-mode network, and may contribute to the attentional deficits common in TBI.

  11. Comparison of Arterial Spin Labeling and Bolus Perfusion-Weighted Imaging for Detecting Mismatch in Acute Stroke

    PubMed Central

    Zaharchuk, Greg; El Mogy, Ibraheem S.; Fischbein, Nancy J.; Albers, Gregory W.

    2012-01-01

    PURPOSE The perfusion-weighted imaging (PWI) – diffusion-weighted imaging (DWI) mismatch paradigm is widely used in stroke imaging studies. Arterial spin labeling (ASL) is an alternative perfusion method that does not require contrast. This study compares the agreement of ASL-DWI and PWI-DWI mismatch classification in stroke patients. MATERIALS AND METHODS This was a retrospective study drawn from all 1.5T MRI studies performed in 2010 at a single institution. Inclusion criteria were: symptom onset<5 days, DWI lesion>10 ml, acquisition of both PWI and ASL. DWI and PWI-Tmax>6 sec lesion volumes were determined using automated software. Patients were classified into reperfused, matched, or mismatch groups. Two radiologists classified ASL-DWI qualitatively into the same categories, blinded to DWI-PWI. Agreement between both individual readers and methods was assessed. RESULTS 51 studies met the inclusion criteria. Seven cases were excluded (1 due to PWI susceptibility artifact, 2 due to motion, and 4 due to severe ASL borderzone sign), resulting in 44 studies for comparison. Inter-rater agreement for ASL–DWI mismatch status was high (κ =0.92, 95% CI 0.80–1.00). ASL-DWI and PWI-DWI mismatch categories agreed in 25/44 cases (57%). In the 16 of 19 discrepant cases (84%), ASL overestimated the PWI lesion size. In 34/44 cases (77%), they agreed regarding the presence of mismatch versus no mismatch. CONCLUSION Mismatch classification based on ASL and PWI agree frequently but not perfectly. ASL tends to overestimate the PWI-Tmax lesion volume. Improved ASL methodologies and/or higher field strength are necessary before ASL can be recommended for routine use in acute stroke. PMID:22539548

  12. Changes in occipital capillary perfusion pressures during coronary artery bypass graft surgery.

    PubMed

    Steinmetz, J A; Langemo, D K

    1996-01-01

    This study compared tissue interface pressures (TIPs) on the occiput of 25 volunteer patients undergoing coronary artery bypass graft (CABG) surgery. Pressures were measured using the Gaymar pressure gauge and electropneumatic sensor before and after induction of anesthesia, after the patient was placed on the cardiopulmonary bypass pump, every 30 minutes throughout the procedure, immediately after the patient came off the pump, and before the incision was closed. Significant differences were found over time on mean TIPs and mean arterial pressures (MAPs). Pre-induction mean TIP was significantly higher than TIPs recorded on-pump, post-pump, and prior to closure. The highest average MAPs were at pre-induction; these were significantly higher than MAPs recorded at all other times. The TIPs recorded during surgery were high enough to put the patient at risk for circulation impairment and pressure ulcer development. Therefore, we recommend repositioning patients' heads regularly during surgery and assessing skin postoperatively for alopecia and pressure ulcers.

  13. Postischemic hyperperfusion on arterial spin labeled perfusion MRI is linked to hemorrhagic transformation in stroke

    PubMed Central

    Yu, Songlin; Liebeskind, David S; Dua, Sumit; Wilhalme, Holly; Elashoff, David; Qiao, Xin J; Alger, Jeffry R; Sanossian, Nerses; Starkman, Sidney; Ali, Latisha K; Scalzo, Fabien; Lou, Xin; Yoo, Bryan; Saver, Jeffrey L; Salamon, Noriko; Wang, Danny JJ

    2015-01-01

    The purpose of this study was to investigate the relationship between hyperperfusion and hemorrhagic transformation (HT) in acute ischemic stroke (AIS). Pseudo-continuous arterial spin labeling (ASL) with background suppressed 3D GRASE was performed during routine clinical magnetic resonance imaging (MRI) on AIS patients at various time points. Arterial spin labeling cerebral blood flow (CBF) maps were visually inspected for the presence of hyperperfusion. Hemorrhagic transformation was followed during hospitalization and was graded on gradient recalled echo (GRE) scans into hemorrhagic infarction (HI) and parenchymal hematoma (PH). A total of 361 ASL scans were collected from 221 consecutive patients with middle cerebral artery stroke from May 2010 to September 2013. Hyperperfusion was more frequently detected posttreatment (odds ratio (OR)=4.8, 95% confidence interval (CI) 2.5 to 8.9, P<0.001) and with high National Institutes of Health Stroke Scale (NIHSS) scores at admission (P<0.001). There was a significant association between having hyperperfusion at any time point and HT (OR=3.5, 95% CI 2.0 to 6.3, P<0.001). There was a positive relationship between the grade of HT and time–hyperperfusion with the Spearman's rank correlation of 0.44 (P=0.003). Arterial spin labeling hyperperfusion may provide an imaging marker of HT, which may guide the management of AIS patients post tissue-type plasminogen activator (tPA) and/or endovascular treatments. Late hyperperfusion should be given more attention to prevent high-grade HT. PMID:25564233

  14. Pre-procedural combined coronary angiography and stress myocardial perfusion imaging using 320-detector CT in unprotected left main and ostial left anterior descending artery intervention.

    PubMed

    Ko, Brian S; Crossett, Marcus; Seneviratne, Sujith K

    2015-07-01

    Pre-procedural anatomic and functional coronary assessment plays a crucial role in selection of patients suitable for unprotected left main percutaneous coronary intervention. Combined coronary computed tomography angiography and adenosine stress computed tomography myocardial perfusion imaging is a non-invasive technique which may provide this information. This is the first report describing its use to assist patient selection and procedural planning prior to elective left main and ostial left anterior descending artery coronary intervention.

  15. Automated detection of arterial input function in DSC perfusion MRI in a stroke rat model

    NASA Astrophysics Data System (ADS)

    Yeh, M.-Y.; Lee, T.-H.; Yang, S.-T.; Kuo, H.-H.; Chyi, T.-K.; Liu, H.-L.

    2009-05-01

    Quantitative cerebral blood flow (CBF) estimation requires deconvolution of the tissue concentration time curves with an arterial input function (AIF). However, image-based determination of AIF in rodent is challenged due to limited spatial resolution. We evaluated the feasibility of quantitative analysis using automated AIF detection and compared the results with commonly applied semi-quantitative analysis. Permanent occlusion of bilateral or unilateral common carotid artery was used to induce cerebral ischemia in rats. The image using dynamic susceptibility contrast method was performed on a 3-T magnetic resonance scanner with a spin-echo echo-planar-image sequence (TR/TE = 700/80 ms, FOV = 41 mm, matrix = 64, 3 slices, SW = 2 mm), starting from 7 s prior to contrast injection (1.2 ml/kg) at four different time points. For quantitative analysis, CBF was calculated by the AIF which was obtained from 10 voxels with greatest contrast enhancement after deconvolution. For semi-quantitative analysis, relative CBF was estimated by the integral divided by the first moment of the relaxivity time curves. We observed if the AIFs obtained in the three different ROIs (whole brain, hemisphere without lesion and hemisphere with lesion) were similar, the CBF ratios (lesion/normal) between quantitative and semi-quantitative analyses might have a similar trend at different operative time points. If the AIFs were different, the CBF ratios might be different. We concluded that using local maximum one can define proper AIF without knowing the anatomical location of arteries in a stroke rat model.

  16. Additive global cerebral blood flow normalization in arterial spin labeling perfusion imaging.

    PubMed

    Stewart, Stephanie B; Koller, Jonathan M; Campbell, Meghan C; Perlmutter, Joel S; Black, Kevin J

    2015-01-01

    To determine how different methods of normalizing for global cerebral blood flow (gCBF) affect image quality and sensitivity to cortical activation, pulsed arterial spin labeling (pASL) scans obtained during a visual task were normalized by either additive or multiplicative normalization of modal gCBF. Normalization by either method increased the statistical significance of cortical activation by a visual stimulus. However, image quality was superior with additive normalization, whether judged by intensity histograms or by reduced variability within gray and white matter.

  17. Maintenance of superior mesenteric arterial perfusion prevents increased intestinal mucosal permeability in endotoxic pigs

    SciTech Connect

    Fink, M.P.; Kaups, K.L.; Wang, H.L.; Rothschild, H.R. )

    1991-08-01

    Lipopolysaccharide increases intestinal mucosal permeability to hydrophilic compounds such as chromium 51-labeled edetate (51Cr-EDTA). The authors sought to determine whether this phenomenon is partly mediated by lipopolysaccharide-induced mesenteric hypoperfusion. They assessed permeability in an isolated segment of ileum by measuring plasma-to-lumen clearances (C) for two probes, 51Cr-EDTA and urea, and expressing the results as a ratio (CEDTA/CUREA). In control pigs (n = 6) resuscitated with Ringer's lactate (RL), mucosal permeability was unchanged during the 210-minute period of observation. In pigs (n = 7) infused with lipopolysaccharide (50 micrograms/kg) and similarly resuscitated with RL, mesenteric perfusion (Qsma) decreased significantly and permeability increased progressively and significantly. When endotoxic pigs (n = 6) were resuscitated with a regimen (RL plus hetastarch plus dobutamine) that preserved normal Qsma, lipopolysaccharide-induced mucosal hyperpermeability was prevented. Resuscitation of endotoxic pigs (n = 6) with RL plus hetastarch provided intermediate protection against both mesenteric hypoperfusion and increased permeability. These data suggest that diminished Qsma contributes to impaired ileal mucosal barrier function in experimental endotoxicosis.

  18. Flurpiridaz F 18 PET: Phase II Safety and Clinical Comparison with SPECT Myocardial Perfusion Imaging for Detection of Coronary Artery Disease

    PubMed Central

    Berman, Daniel S.; Maddahi, Jamshid; Tamarappoo, B. K.; Czernin, Johannes; Taillefer, Raymond; Udelson, James E.; Gibson, C. Michael; Devine, Marybeth; Lazewatsky, Joel; Bhat, Gajanan; Washburn, Dana

    2015-01-01

    Objectives Phase II trial to assess flurpiridaz F 18 for safety and compare its diagnostic performance for PET myocardial perfusion imaging (MPI) to Tc-99m SPECT-MPI regarding image quality, interpretative certainty, defect magnitude and detection of coronary artery disease (CAD)(≥ 50% stenosis) on invasive coronary angiography (ICA). Background In preclinical and phase I studies, flurpiridaz F 18 has shown characteristics of an essentially ideal MPI tracer. Methods 143 patients from 21 centers underwent rest-stress PET and Tc-99m SPECT-MPI. Eighty-six patients underwent ICA, and 39 had low-likelihood of CAD. Images were scored by 3 independent, blinded readers. Results A higher % of images were rated as excellent/good on PET vs. SPECT on stress (99.2% vs. 88.5%, p<0.01) and rest (96.9% vs. 66.4, p<0.01) images. Diagnostic certainty of interpretation (% cases with definitely abnormal/normal interpretation) was higher for PET vs. SPECT (90.8% vs. 70.9%, p<0.01). In 86 patients who underwent ICA, sensitivity of PET was higher than SPECT [78.8% vs. 61.5%, respectively (p=0.02)]. Specificity was not significantly different (PET:76.5% vs. SPECT:73.5%). Receiver operating characteristic curve area was 0.82±0.05 for PET and 0.70±0.06 for SPECT (p=0.04). Normalcy rate was 89.7% with PET and 97.4% with SPECT (p=NS). In patients with CAD on ICA, the magnitude of reversible defects was greater with PET than SPECT (p=0.008). Extensive safety assessment revealed that flurpiridaz F 18 was safe in this cohort. Conclusions In this Phase 2 trial, PET MPI using flurpiridaz F 18 was safe and superior to SPECT MPI for image quality, interpretative certainty, and overall CAD diagnosis. PMID:23265345

  19. Digital auscultation of the uterine artery: a measure of uteroplacental perfusion.

    PubMed

    Riknagel, Diana; Dinesen, Birthe; Zimmermann, Henrik; Farlie, Richard; Schmidt, Samuel; Toft, Egon; Struijk, Johannes Jan

    2016-07-01

    This observational study investigated digital auscultation for the purpose of assessing the clinical feasibility of monitoring vascular sounds in pregnancy. The study was performed at the Regional Hospital Viborg, Denmark, and included 29 pregnant women, 10 non-pregnant women and 10 male participants. Digital auscultation was performed with an electronic stethoscope bilaterally near the uterine arteries and correlated to the clinical diagnosis of preeclampsia (PE), intrauterine growth restriction (IUGR) or normal pregnancy in the group of pregnant participants. In the group of non-pregnant participants, digital auscultation was performed as control measurements in the same anatomical positions. The auscultations displayed pulse waveforms comprising systolic and diastolic periods in 20 of the 29 pregnant participants. However, in the non-pregnant and male participants, the pulse waveforms were absent. The pulsatile patterns are thus likely to originate from the arteries in relation to the pregnant uterus. In the participants displaying pulse waveforms, the presence of a dicrotic notch appeared with a sensitivity of 89% and a specificity of 100% in the discrimination of normal pregnancies (n  =  11) from pregnancies with PE or IUGR (n  =  9), (p  <  0.001). This preliminary study shows the potential of identifying vascular complications during pregnancy such as preeclampsia and intrauterine growth restriction. The morphology of the derived pulse contour should be investigated and could be further developed to identify pathophysiology.

  20. Improving cerebral blood flow quantification for arterial spin labeled perfusion MRI by removing residual motion artifacts and global signal fluctuations.

    PubMed

    Wang, Ze

    2012-12-01

    Denoising is critical to improving the quality and stability of cerebral blood flow (CBF) quantification in arterial spin labeled (ASL) perfusion magnetic resonance imaging (MRI) due to the intrinsic low signal-to-noise-ratio (SNR) of ASL data. Previous studies have been focused on reducing the spatial or temporal noise using standard filtering techniques, and less attention has been paid to two global nuisance effects, the residual motion artifacts and the global signal fluctuations. Since both nuisances affect the whole brain, removing them in advance should enhance the CBF quantification quality for ASL MRI. The purpose of this paper was to assess this potential benefit. Three methods were proposed to suppress each or both of the two global nuisances. Their performances for CBF quantification were validated using ASL data acquired from 13 subjects. Evaluation results showed that covarying out both global nuisances significantly improved temporal SNR and test-retest stability of CBF measurement. Although the concept of removing both nuisances is not technically novel per se, this paper clearly showed the benefits for ASL CBF quantification. Dissemination of the proposed methods in a free ASL data processing toolbox should be of interest to a broad range of ASL users.

  1. Tomographic thallium-201 myocardial perfusion scintigrams after maximal coronary artery vasodilation with intravenous dipyridamole: comparison of qualitative and quantitative approaches

    SciTech Connect

    Francisco, D.A.; Collins, S.M.; Go, R.T.; Ehrhardt, J.C.; Van Kirk, O.C.; Marcus, M.L.

    1982-08-01

    Eighty-six patients had thallium-201 (/sup 201/Tl) myocardial perfusion scintigrams after intense coronary artery dilation with i.v. dipyridamole. Tomographic and planar /sup 201/Tl scintigrams were obtained in each patient. Tomographic scintigrams were interpreted using quantitative or visual criteria; planar scintigrams were assessed using visual criteria only. When visual criteria were used, interobserver variability was 40% for tomographic scintigrams and 44% for planar scintigrams. In the 24 patients with normal or nonsignificant CAD, quantitative analysis of the tomograms (range approach) indicated that one of 24 (4%) had a positive image (specificity 96%%); in contrast, when visual criteria were used to interpret the tomographic or planar /sup 201/Tl scintigrams, eight of 24 (33%) had positive scintigrams (specificity 67%). In the 51 abnormal patients, the sensitivity of detecting CAD was 46 of 51 (90%) for tomographic scintigrams interpreted quantitatively, 39 of 51 (76%) for tomographic scintigrams interpreted visually and 41 of 51 (80%) for planar scintigrams assessed visually. The tomographic imaging procedure (quantitative interpretation) also demonstrated a high sensitivity (89%) and specificity (100%) in 28 patients (10 normal and 18 CAD), with a clinical diagnosis of unstable angina pectoris. Overall, the predictive accuracy of an abnormal scintigram with quantitative tomographic imaging (98%) was significantly better (p<0.05) than either qualitative planar or pinhole imaging. (JMT)

  2. Arterial Spin Labeling Magnetic Resonance Perfusion for Traumatic Brain Injury: Technical Challenges and Potentials.

    PubMed

    Andre, Jalal B

    2015-10-01

    Traumatic brain injury (TBI), including concussion, is a public health concern, as it affects over 1.7 million persons in the United States per year. Yet, the diagnosis of TBI, particularly mild TBI (mTBI), can be controversial, as neuroimaging findings can be sparse on conventional magnetic resonance and computed tomography examinations, and when present, often poorly correlate with clinical signs and symptoms. Furthermore, the discussion of TBI, concussion, and head impact exposure is immediately complicated by the many differing opinions of what constitutes each, their respective severities, and how the underlying biomechanics of the inciting head impact might alter the distribution, severity, and prognosis of the underlying brain injury. Advanced imaging methodologies hold promise in improving the sensitivity and detectability of associated imaging biomarkers that might better correlate with patient outcome and prognostication, allowing for improved triage and therapeutic guidance in the setting of TBI, particularly in mTBI. This work will examine the defining symptom complex associated with mTBI and explore changes in cerebral blood flow measured by arterial spin labeling, as a potential imaging biomarker for TBI, and briefly correlate these observations with findings identified by single photon emission computed tomography and positron emission tomography imaging.

  3. Pseudo-continuous arterial spin labeling imaging of cerebral blood perfusion asymmetry in drug-naïve patients with first-episode major depression

    PubMed Central

    Chen, Guangdong; Bian, Haiman; Jiang, Deguo; Cui, Mingwei; Ji, Shengzhang; Liu, Mei; Lang, Xu; Zhuo, Chuanjun

    2016-01-01

    Many previous studies have reported that regional cerebral blood flow (rCBF) aberrations may be one of the pathological characteristics of depression and rCBF has demonstrated a certain degree of asymmetry. However, studies investigating the cerebral blood perfusion asymmetry changes of drug-naïve patients experiencing their first episode of major depression using pseudo-continuous arterial spin labeling (pCASL) are rare. Ten drug-naïve patients experiencing their first major depression episode and 15 healthy volunteers were enrolled in the current study. A novel pCASL method was applied to whole brain MRI scans of all of the samples. The Statistics Parameter Mapping and Relative Expression Software Tool software packages were used for the pre-processing and statistical analysis of the two sets of images, and the differences in the cerebral blood perfusion at the whole brain level were compared between the two groups. Compared with the healthy control group, the cerebral perfusion of the depression patients showed an asymmetric pattern. Decreased cerebral blood perfusion regions were primarily located in the left hemisphere, specifically in the left temporal lobe, frontal lobe and cingulate cortex [P<0.05 and cluster size ≥30 with false discovery rate (FDR) correction]. Simultaneously, increased perfusion regions were predominantly located in the right hemisphere, specifically in the right cerebellum, thalamus, frontal lobe and anterior cingulate cortex (P<0.05 and cluster size ≥30, with FDR correction). Thus, pCASL may characterize the alterations in cerebral blood perfusion of patients with depression. PMID:28101340

  4. Total Coronary Atherosclerotic Plaque Burden Assessment by CT Angiography for Detecting Obstructive Coronary Artery Disease Associated with Myocardial Perfusion Abnormalities

    PubMed Central

    Kishi, Satoru; Magalhães, Tiago A.; Cerci, Rodrigo J.; Matheson, Matthew B.; Vavere, Andrea; Tanami, Yutaka; Kitslaar, Pieter H.; George, Richard T.; Brinker, Jeffrey; Miller, Julie M.; Clouse, Melvin E.; Lemos, Pedro A.; Niinuma, Hiroyuki; Reiber, Johan H.C.; Rochitte, Carlos E.; Rybicki, Frank J.; Di Carli, Marcelo F.; Cox, Christopher; Lima, Joao A.C.; Arbab-Zadeh, Armin

    2016-01-01

    Background Total atherosclerotic plaque burden assessment by CT angiography (CTA) is a promising tool for diagnosis and prognosis of coronary artery disease (CAD) but its validation is restricted to small clinical studies. We tested the feasibility of semi-automatically derived coronary atheroma burden assessment for identifying patients with hemodynamically significant CAD in a large cohort of patients with heterogenous characteristics. Methods This study focused on the CTA component of the CORE320 study population. A semi-automated contour detection algorithm quantified total coronary atheroma volume defined as the difference between vessel and lumen volume. Percent atheroma volume (PAV = [total atheroma volume/total vessel volume]×100) was the primary metric for assessment (n=374). The area under the receiver operating characteristic curve (AUC) determined the diagnostic accuracy for identifying patients with hemodynamically significant CAD defined as ≥50% stenosis by quantitative coronary angiography and associated myocardial perfusion abnormality by SPECT. Results Of 374 patients, 139 (37%) had hemodynamically significant CAD. The AUC for PAV was 0.78 (95% confidence interval [CI] 0.73–0.83) compared to 0.84 [0.79–0.88] by standard expert CTA interpretation (p=0.02). Accuracy for both CTA (0.91 [0.87, 0.96]) and PAV (0.86 [0.81–0.91]) increased after excluding patients with history of CAD (p<0.01 for both). Bland-Altman analysis revealed good agreement between two observers ( bias of 280.2 mm3 [161.8, 398.7]). Conclusions A semi-automatically derived index of total coronary atheroma volume yields good accuracy for identifying patients with hemodynamically significant CAD, though marginally inferior to CTA expert reading. These results convey promise for rapid, reliable evaluation of clinically relevant CAD. PMID:26817414

  5. Reproducibility of Kidney Perfusion Measurements With Arterial Spin Labeling at 1.5 Tesla MRI Combined With Semiautomatic Segmentation for Differential Cortical and Medullary Assessment

    PubMed Central

    Hammon, Matthias; Janka, Rolf; Siegl, Christian; Seuss, Hannes; Grosso, Roberto; Martirosian, Petros; Schmieder, Roland E.; Uder, Michael; Kistner, Iris

    2016-01-01

    Abstract Magnetic resonance imaging with arterial spin labeling (ASL) is a noninvasive approach to measure organ perfusion. The purpose of this study was to evaluate the reproducibility of ASL kidney perfusion measurements with semiautomatic segmentation, which allows separate quantification of cortical and medullary perfusion. The right kidneys of 14 healthy volunteers were examined 6 times on 2 occasions (3 times at each occasion). There was a 10-minute pause between each examination and a 14-day interval between the 2 occasions. Cortical, medullary, and whole kidney parenchymal perfusion was determined with customized semiautomatic segmentation software. Coefficient of variances (CVs) and intraclass correlations (ICCs) were calculated. Mean whole, cortical, and medullary kidney perfusion was 307.26 ± 25.65, 337.10 ± 34.83, and 279.61 ± 26.73 mL/min/100 g, respectively. On session 1, mean perfusion for the whole kidney, cortex, and medulla was 307.08 ± 26.91, 336.79 ± 36.54, and 279.60 ± 27.81 mL/min/100 g, respectively, and on session 2, 307.45 ± 24.65, 337.41 ± 33.48, and 279.61 ± 25.94 mL/min/100 g, respectively (P > 0.05; R2 = 0.60/0.59/0.54). For whole, cortical, and medullary kidney perfusion, the total ICC/CV were 0.97/3.43 ± 0.86%, 0.97/4.19 ± 1.33%, and 0.96/4.12 ± 1.36%, respectively. Measurements did not differ significantly and showed a very good correlation (P > 0.05; R2 = 0.75/0.76/0.65). ASL kidney measurements combined with operator-independent semiautomatic segmentation revealed high correlation and low variance of cortical, medullary, and whole kidney perfusion. PMID:26986143

  6. Call-fleming syndrome (reversible cerebral artery vasoconstriction) and aneurysm associated with multiple recreational drug use.

    PubMed

    Drazin, Doniel; Alexander, Michael J

    2013-01-01

    Drug abuse represents a significant health issue. Evidence suggests that recreational drug use has a direct effect on the cerebral vasculature and is of greater concern in those with undiagnosed aneurysms or vascular malformations. The authors report a case of thunderclap headache with a negative head CT and equivocal lumbar puncture after a drug-fueled weekend. The patient underwent diagnostic cerebral angiogram which demonstrated multisegmental, distal areas of focal narrowing of the middle, anterior, posterior, and posterior inferior cerebral artery and an incidental aneurysm. It is often difficult to determine the exact origin of symptoms; thus we were left with a bit of a chicken or the egg debate, trying to decipher which part came first. Either the aneurysm ruptured with associated concomitant vasospasm or it is a case of Call-Fleming syndrome (reversible cerebral artery vasoconstriction) with an incidental aneurysm. The authors proposed their management and rationale of this complex case.

  7. Absent or reversed end diastolic flow velocity in the umbilical artery and necrotising enterocolitis.

    PubMed Central

    Malcolm, G; Ellwood, D; Devonald, K; Beilby, R; Henderson-Smart, D

    1991-01-01

    Absent or reversed end diastolic flow (AREDF) velocities in the umbilical artery were identified in 25 high risk pregnancies. In six pregnancies the fetus was abnormal and all but one of these ended in perinatal death. Of the 19 morphologically normal fetuses, three died in utero and there were four neonatal or infant deaths. The mortality rate was 48% for all pregnancies and 37% for those with morphologically normal fetuses. There was a highly significant increased risk for the development of necrotising enterocolitis in these morphologically normal fetuses with AREDF (53%) compared with controls (6%) who did have umbilical artery end diastolic flow velocities in fetal life. There were no significant differences between the matched pairs for parameters of neonatal outcome chosen to reflect neonatal morbidity. These findings demonstrate the close association between AREDF and necrotising enterocolitis that appears to be independent of other variables such as degree of growth retardation, prematurity, and perinatal asphyxia. PMID:1863128

  8. Brachial Artery Reconstruction in Trauma Using Reversed Arm Vein from the Injured Upper Limb

    PubMed Central

    Harnarayan, Patrick

    2016-01-01

    Background: Brachial artery repair may be technically challenging with a paucity of guidelines. The use arm vein (AV) from the traumatized limb is herein described. Methods: Data were prospectively collected from 2002 to 2016 on brachial artery injury including age, sex, mechanism/site of injury, and repair technique. Categories included AV and non-arm vein (NAV) groups. One-year outcomes were noted. Results: All 31 cases studied were of men with an age range of 16 to 73 years (mean = 28). Injuries included 13 gunshots, 7 stabbings, 6 glass injuries, 2 dislocated elbows, 1 crush, 1 impalement, and 1 avulsion. Site of injuries included the antecubital region in 25, midbrachial in 5, and proximal brachial in 1, with 4 associated fractures. Repair was done using reversed AV from the traumatized limb in 15 cases and NAV in 16. In the AV group, the adjacent basilic vein was used in 9 cases, the adjacent cephalic vein in 3, and the distal (or wrist area) cephalic vein in 3. The limb salvage rates in the AV versus NAV groups were 100% and 94%, respectively (Fisher’s exact t test, P = 1.00), with no major technique-related complications. Conclusions: The outcomes of using reversed AV from the traumatized limb are equivalent to those of other standard techniques such as primary repair, polytetrafluoroethylene, or reversed great saphenous vein, with a 1-year limb salvage rate of 100%. Additionally, advantages include decreased wound complications, better vein graft--artery caliber match, and shorter operating times while maintaining acceptable patency rates. PMID:27826464

  9. Right ventricular reverse remodelling in Idiopathic Pulmonary Arterial Hypertension diagnosed during pregnancy: Is it possible?

    PubMed

    Paciocco, Giuseppe; Lombi, Andrea; Vincenzi, Antonella; Pesci, Alberto; Achilli, Felice

    2017-01-01

    We present a case of a 36-year-old woman who developed a severe form of Idiopathic Pulmonary Arterial Hypertension (IPAH) during pregnancy and after emergency delivery. The management of IPAH during or after pregnancy is complex. Due to the severity of her IPAH, an upfront triple combination therapy, including i.v. epoprostenol, was started. The rapid institution of this treatment regimen allowed a complete right ventricular reverse remodelling after 1 year of therapy, leading to a down-titration until complete suspension of epoprostenol from the treatment regimen.

  10. Multi-Parametric Assessment of Vascular Function in Peripheral Artery Disease: Dynamic Measurement of Skeletal Muscle Perfusion, BOLD Signal, and Venous Oxygen Saturation

    PubMed Central

    Englund, Erin K.; Langham, Michael C.; Ratcliffe, Sarah J.; Fanning, Molly; Wehrli, Felix W.; Mohler, Emile R.; Floyd, Thomas F.

    2015-01-01

    Background Endothelial dysfunction present in patients with peripheral artery disease (PAD) may be better understood by measuring the temporal dynamics of blood flow and oxygen saturation during reactive hyperemia than by conventional static measurements. Methods and Results Perfusion, Intravascular Venous Oxygen saturation, and T2* (PIVOT), a recently developed MRI technique, was used to measure the response to an ischemia-reperfusion paradigm in ninety-six patients with PAD of varying severity, and ten healthy controls. Perfusion, venous oxygen saturation (SvO2), and T2* were each quantified in the calf at two second temporal resolution, yielding a dynamic time course for each variable. Compared to healthy controls, patients had a blunted and delayed hyperemic response. Moreover, patients with lower ankle-brachial index had: 1) a more delayed reactive hyperemia response time, manifesting as an increase in time to peak perfusion in the gastrocnemius, soleus, and peroneus muscles, and in the anterior compartment; 2) an increase in the time to peak T2* measured in the soleus muscle; and 3) a prolongation of the posterior tibial vein SvO2 washout time. Intra- and inter-session repeatability was also assessed. Results indicated that time to peak perfusion and time to peak T2* were the most reliable extracted time course metrics. Conclusions Perfusion, dynamic SvO2, and T2* response times following induced ischemia are highly correlated with PAD disease severity. Combined imaging of peripheral microvascular blood flow and dynamics of oxygen saturation with PIVOT may be a useful tool to investigate the pathophysiology of PAD. PMID:25873722

  11. Difference in the value of arterial and end-tidal carbon dioxide tension according to different surgical positions: Does it reliably reflect ventilation-perfusion mismatch?

    PubMed Central

    Joo, Jin; Kim, Young Hee; Choi, Jong Ho

    2012-01-01

    Background Body posture, as a gravitational factor, has a clear impact on pulmonary ventilation and perfusion. In lung units with mismatched ventilation and perfusion, gas exchange and/or elimination of carbon dioxide can be impaired. In this situation, differences in the value of arterial and end-tidal carbon dioxide tension [Δ(PaCO2 - PETCO2)] are expected to increase. This study was conducted to observe how Δ(PaCO2 - PETCO2) changed according to the 3 different surgical positions, and to determine whether Δ(PaCO2 - PETCO2) is a reliable predictor of ventilation/perfusion mismatch when a patient is in different postural positions. Methods Fifty-nine patients were divided into either the chronic obstructive pulmonary disease (COPD) group (n = 29) or the non-COPD group (n = 30). PaCO2 and PETCO2 were measured during surgery in the supine, prone, and lateral decubitus positions after a 10 minute stabilization period. The Δ(PaCO2 - PETCO2) were calculated and compared among positions. Results The Δ(PaCO2 - PETCO2) decreased slightly in the prone position and increased significantly in the lateral decubitus position compared with the supine position in both groups. These patterns almost corresponded with the degree of ventilation/perfusion mismatch from the results of the radiological studies. The Δ(PaCO2 - PETCO2) in the COPD group was significantly greater than that in the non-COPD group at all surgical positions. Conclusions Lateral decubitus position is associated with marked increase in Δ(PaCO2 - PETCO2), especially in patients with COPD. The Δ(PaCO2 - PETCO2) is a simple and reliable indicator to predict ventilation/perfusion mismatch at different surgical positions in patients with or without COPD. PMID:23060977

  12. Countercurrent transfer of dopamine from venous blood in the cavernous sinus to the arterial blood supplying the brain - the perfused rabbit head as an experimental model.

    PubMed

    Muszak, J; Krzymowski, T; Gilun, P; Stefanczyk-Krzymowska, S

    2014-10-01

    The objective of the current study was to check whether countercurrent transfer of dopamine occurs in the cavernous sinus of the rabbit and whether the rabbit can be used as an animal model to study cavernous sinus function. After exsanguination of the animal, oxygenated and warmed (37°C) Hanseneleit-Krebs buffer with autologous or homologous blood (in a 3:1 or 1:1 ratio) was pumped through both common carotid arteries into the head (60 ml/min; 80-100 mm Hg) and radiolabeled dopamine (3(H)-DA, 10 μCi) was infused into the cavernous sinus through the angular oculi vein. Cerebral blood from the basilar artery was collected from the cannulated vertebral artery during 3(H)-DA infusion and for 10 minutes after completion of infusion. Selected brain tissue samples were collected after completion of the head perfusion. It was demonstrated that dopamine can penetrate from the rabbit's cavernous sinus to the internal carotid artery supplying the brain. Dopamine permeation was greater when the rabbit head was perfused with buffer and blood in a 3:1 ratio than with 1:1 (P<0.01). When the head was perfused with buffer and blood in a 3:1 ratio, significant radioactivity was found in samples collected from the brain basilar artery during and after 3(H)-DA infusion (P<0.001). The radioactivity was identified as 34.13 ± 2.7% unmetabolized 3(H)-DA and 65.9 ± 2.7% its metabolites. Significant radioactivity was also found in some brain tissue samples in both groups (P<0.05). The concentration of free radiolabeled dopamine particles in the dialysate of blood plasma and plasma diluted with buffer did not differ significantly. Because the structures of the cavernous sinus and cavernous fragment of the internal carotid artery of the rabbit are similar to those in humans, it suggests that rabbits can serve as a model for experimental physiological studies of cavernous sinus function and retrograde dopamine transfer in the cavernous sinus should be considered as an important link in

  13. Effect of Ca2+, cyclic GMP, and cyclic AMP added to artificial solution perfusing lingual artery on frog gustatory nerve responses

    PubMed Central

    1982-01-01

    The lingual artery of the bullfrog was perfused with artificial solution and the effects of Ca2+, Ca-channel blockers (MnCl2 and verapamil), cGMP, and cAMP added to the perfusing solution of the gustatory nerve responses were examined. The responses to chemical stimuli of group 1 (CaCl2, NaCl, distilled water, D-galactose, and L- threonine) applied to the tongue surface were greatly decreased by a decrease in Ca2+ concentration in the perfusing solution, suppressed by the Ca-channel blockers, enhanced by cGMP, and suppressed by cAMP. The responses to chemical stimuli of group 2 (quinine hydrochloride, theophylline, ethanol, and HCl) were practically not affected by a decrease in Ca2+ concentration, the Ca-channel blockers, cGMP, and cAMP. The responses to the stimuli of group 1 seem to be induced by Ca influx into a taste cell that is triggered by depolarization and modulated by the cyclic nucleotides in a taste cell. The responses to group 2 seem to be induced without accompanying Ca influx. PMID:6294223

  14. [Acute stent thrombosis and reverse transient left ventricular dilatation after performing a single-photon emission computed tomography myocardial perfusion].

    PubMed

    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.

  15. Evaluation of Intrahepatic Perfusion on Fusion Imaging Using a Combined CT/SPECT System: Influence of Anatomic Variations on Hemodynamic Modification Before Installation of Implantable Port Systems for Hepatic Arterial Infusion Chemotherapy

    SciTech Connect

    Ikeda, Osamu Tamura, Yoshitaka; Nakasone, Yutaka; Shiraishi, Shinya; Kawanaka, Kouichi; Tomiguchi, Seiji; Takamori, Hiroshi; Chikamoto, Akira; Kanemitsu, Keiichirou; Yamashita, Yasuyuki

    2007-06-15

    Background. In some patients with hepatic tumors, anatomic variations in the hepatic arteries may require hemodynamic modification to render effective hepatic arterial infusion chemotherapy delivered via implantable port systems. We used a combined CT/SPECT system to obtain fused images of the intrahepatic perfusion patterns in patients with such anatomic variations and assessed their effects on the treatment response of hepatic tumors. Methods. Using a combined SPECT/CT system, we obtained fused images in 110 patients with malignant liver tumors (n = 75) or liver metastasis from unresectable pancreatic cancer (n = 35). Patients with anatomic hepatic arteries variations underwent hemodynamic modification before the placement of implantable port systems for hepatic arterial infusion chemotherapy. We evaluated their intrahepatic perfusion patterns and the initial treatment response of their liver tumors. The perfusion patterns on the fused images were classified as homogeneous, local hypoperfusion, and/or perfusion defect. Using the WHO criteria of complete response (CR), partial response (PR), no change (NC), and progressive disease (PD), we evaluated the patients' tumor responses after 3 months on multislice helical CT scans. The treatment was regarded as effective in patients who achieved a complete response or partial response. Results. Anatomic hepatic artery variations were present in 15 of the 110 patients (13.6%); 5 manifested replacement of the left hepatic artery (LHA), 8 of the right hepatic artery (RHA), and 1 each had replacement of the RHA and LHA, and replacement of the LHA plus an accessory RHA. In 13 of these 15 patients (87%), occlusion with metallic coils was successful. On fusion imaging, the perfusion patterns were recorded as homogeneous in 6 patients (43%), as hypoperfusion in 7 (50%), and 1 patient had a perfusion defect (7.1%) in the embolized arterial region. Of the 8 patients with RHA replacement, 4 manifested a homogeneous distribution and

  16. Whole-Brain Computed Tomographic Perfusion Imaging in Acute Cerebral Venous Sinus Thrombosis

    PubMed Central

    Mokin, Maxim; Ciambella, Chelsey C.; Masud, Muhammad W.; Levy, Elad I.; Snyder, Kenneth V.; Siddiqui, Adnan H.

    2016-01-01

    Background Acute cerebral venous sinus thrombosis (VST) can be difficult to diagnose because of its diverse clinical presentation. The utility of perfusion imaging for diagnosing VST is not well understood. Summary We retrospectively reviewed cases of acute VST in patients who underwent whole-brain (320-detector-row) computed tomographic (CT) perfusion imaging in combination with craniocervical CT venography. Perfusion maps that were analyzed included cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time, and time to peak. Among the 10 patients with acute VST included in this study, 9 had perfusion abnormalities. All perfusion abnormalities were localized in areas adjacent to the occluded sinus and did not match typical anterior or posterior circulation arterial territories. Bilateral perfusion deficits were seen in 4 cases. In 2 cases, parenchymal hemorrhage was diagnosed on noncontrast CT imaging; in those cases, focal CBV and CBF were reduced. Key Messages Whole-brain CT perfusion imaging with 320-detector-row scanners can further assist in establishing the diagnosis of VST by detecting perfusion abnormalities corresponding to venous and not arterial territories. CT perfusion could assist in the differentiation between focal reversible changes, such as those caused by vasogenic edema, and irreversible changes due to infarction. PMID:27051406

  17. Ultrarapid quantitation of maize proteins by perfusion and monolithic reversed-phase high-performance liquid chromatography.

    PubMed

    Rodríguez-Nogales, J M; del Alamo, M; García, M C; Cifuentes, A; Marina, M L

    2009-04-22

    The main objective of this study was to develop a new methodology alternative to the classical Kjeldahl analysis for determining maize proteins in maize products and seeds. For that purpose, two different chromatographic methodologies using perfusion and monolithic stationary phases, both enabling rapid separations of maize proteins, were investigated. Due to the difficulty to find suitable standards for this type of analysis, three different maize products were initially tested as proteins standards: zein F4000, corn gluten meal, and maize flour. Different figures of merit (i.e., linearity, correlation coefficient, precision, limits of detection and quantitation), as well as the presence of matrix inferences, were investigated. The results obtained for the different chromatographic stationary phases and protein standards were compared in order to select the most suitable analytical conditions. Despite both perfusion and monolithic methodologies resulting, in general, as appropriate for the quantitation of maize proteins, the highest reduction of analysis time and lowest detection and determination limits provided by perfusion methodology enabled to select this one as the method of choice for the quantitation of maize proteins. Regarding the different protein standards studied in this work, in general the best results were obtained using the zein standard. Compared to Kjeldahl methodology, perfusion chromatography yields total protein contents in shorter analysis time while enabling the separation of the different kinds of proteins. Due to the high diversity and complexity of industrial maize products, the proposed chromatographic method could be a very useful tool for their routine analysis.

  18. Reversible Pulmonary Arterial Hypertension Associated with Dasatinib for Chronic Myeloid Leukemia

    PubMed Central

    Hong, Ji Hyung; Lee, Sung-Eun; Choi, Soo Young; Kim, Soo-Hyun; Jang, Eun-Jung; Bang, Ju-Hee; Park, Jin Eok; Jeon, Hye-Rim; Oh, Yun Jeong; Yi, Jeong-Eun; Jung, Hae Ok; Youn, Ho Joong; Kim, Dong-Wook

    2015-01-01

    We describe two cases of pulmonary arterial hypertension (PAH) that occurred under dasatinib treatment and were resolved after dasatinib discontinuation. Two patients with chronic phase chronic myeloid leukemia (CML) were switched to dasatinib therapy because of hematological progress while receiving imatinib. These patients had New York Heart Association (NYHA) functional class II dyspnea with elevated right ventricular systolic pressure (RVSP), which progressed under dasatinib treatment. After dasatinib treatment was discontinued, subjective symptoms were improved to NYHA functional class I and the follow-up transthoracic Doppler echocardiography showed improved RVSP. Treatment with an alternate tyrosine kinase inhibitor was initiated and had been continued without development of dyspnea or elevation of RVSP. This report suggests that dasatinib can cause the reversible PAH, therefore, routine cardiopulmonary evaluation before and during treatment with dasatinib may be needed in CML patients with clinical manifestations. PMID:25648097

  19. Reversible Cerebral Vasoconstriction Syndrome With Involvement of External Carotid Artery Branches

    PubMed Central

    Shaik, S.; Chhetri, S. K.; Roberts, G.; Wuppalapati, S.

    2014-01-01

    A 44-year-old woman presented with recurrent episodes of thunderclap headache. Neurological examination and computed tomography brain imaging were unremarkable. Cerebrospinal fluid findings were consistent with subarachnoid hemorrhage. Computed tomography angiography of the circle of Willis showed multiple areas of segmental vasoconstriction. This finding was confirmed on cerebral catheter angiography, with segmental vasoconstriction involving bilateral internal carotid, posterior cerebral, and external carotid branches. No aneurysm or other vascular abnormality was identified. She received treatment with nimodipine. A selective serotonin reuptake inhibitor, started 4 weeks earlier, was discontinued. Follow-up angiography after 3 months demonstrated complete resolution of the segmental vasoconstriction, confirming the diagnosis of reversible cerebral vasoconstriction syndrome (RCVS). She remained headache free at follow-up. To our knowledge, external carotid artery branch involvement in RCVS has been described only in one previous occasion. PMID:24982719

  20. Plasma proteomic analysis of stable coronary artery disease indicates impairment of reverse cholesterol pathway

    PubMed Central

    Basak, Trayambak; Tanwar, Vinay Singh; Bhardwaj, Gourav; Bhardwaj, Nitin; Ahmad, Shadab; Garg, Gaurav; V, Sreenivas; Karthikeyan, Ganesan; Seth, Sandeep; Sengupta, Shantanu

    2016-01-01

    Coronary artery disease (CAD) is one of the largest causes of death worldwide yet the traditional risk factors, although useful in identifying people at high risk, lack the desired predictive accuracy. Techniques like quantitative plasma proteomics holds immense potential to identify newer markers and this study (conducted in three phases) was aimed to identify differentially expressed proteins in stable CAD patients. In the first (discovery) phase, plasma from CAD cases (angiographically proven) and controls were subjected to iTRAQ based proteomic analysis. Proteins found to be differentially expressed were then validated in the second and third (verification and validation) phases in larger number of (n = 546) samples. After multivariate logistic regression adjusting for confounding factors (age, diet, etc.), four proteins involved in the reverse cholesterol pathway (Apo A1, ApoA4, Apo C1 and albumin) along with diabetes and hypertension were found to be significantly associated with CAD and could account for approximately 88% of the cases as revealed by ROC analysis. The maximum odds ratio was found to be 6.70 for albumin (p < 0.0001), followed by Apo AI (5.07, p < 0.0001), Apo CI (4.03, p = 0.001), and Apo AIV (2.63, p = 0.003). Down-regulation of apolipoproteins and albumin implicates the impairment of reverse cholesterol pathway in CAD. PMID:27350024

  1. Plasma proteomic analysis of stable coronary artery disease indicates impairment of reverse cholesterol pathway.

    PubMed

    Basak, Trayambak; Tanwar, Vinay Singh; Bhardwaj, Gourav; Bhardwaj, Nitin; Ahmad, Shadab; Garg, Gaurav; V, Sreenivas; Karthikeyan, Ganesan; Seth, Sandeep; Sengupta, Shantanu

    2016-06-28

    Coronary artery disease (CAD) is one of the largest causes of death worldwide yet the traditional risk factors, although useful in identifying people at high risk, lack the desired predictive accuracy. Techniques like quantitative plasma proteomics holds immense potential to identify newer markers and this study (conducted in three phases) was aimed to identify differentially expressed proteins in stable CAD patients. In the first (discovery) phase, plasma from CAD cases (angiographically proven) and controls were subjected to iTRAQ based proteomic analysis. Proteins found to be differentially expressed were then validated in the second and third (verification and validation) phases in larger number of (n = 546) samples. After multivariate logistic regression adjusting for confounding factors (age, diet, etc.), four proteins involved in the reverse cholesterol pathway (Apo A1, ApoA4, Apo C1 and albumin) along with diabetes and hypertension were found to be significantly associated with CAD and could account for approximately 88% of the cases as revealed by ROC analysis. The maximum odds ratio was found to be 6.70 for albumin (p < 0.0001), followed by Apo AI (5.07, p < 0.0001), Apo CI (4.03, p = 0.001), and Apo AIV (2.63, p = 0.003). Down-regulation of apolipoproteins and albumin implicates the impairment of reverse cholesterol pathway in CAD.

  2. Reverse flow first dorsal metacarpal artery flap for covering the defect of distal thumb.

    PubMed

    Checcucci, Giuseppe; Galeano, Mariarosaria; Zucchini, Maura; Zampetti, Pier Giuseppe; Ceruso, Massimo

    2014-05-01

    Reconstruction of distal thumb injuries still remains a challenge for hand surgeons. Surgical treatment includes the use of local, regional, and free flaps. The purpose of this report is to present the results of the use of a sensitive reverse flow first dorsal metacarpal artery (FDMA) flap. The skin flap was designed on the radial side of the proximal phalanx of the index finger based on the ulnar and radial branch of the FDMA and a sensory branch of the superficial radial nerve. This neurovascular flap was used in five patients to cover distal soft-tissue thumb defects. All flaps achieved primary healing except for one patient in whom superficial partial necrosis of the flap occurred, and the defect healed by second intention. All patients maintained the thumb original length and were able to return to their previous daily activities. The reverse flow FDMA flap is a reliable option to cover immediate and delayed defects of distal thumb, offering acceptable functional and cosmetic outcomes in respect to sensibility, durability, and skin-match.

  3. Superior diagnostic performance of perfusion-cardiovascular magnetic resonance versus SPECT to detect coronary artery disease: The secondary endpoints of the multicenter multivendor MR-IMPACT II (Magnetic Resonance Imaging for Myocardial Perfusion Assessment in Coronary Artery Disease Trial)

    PubMed Central

    2012-01-01

    Background Perfusion-cardiovascular magnetic resonance (CMR) is generally accepted as an alternative to SPECT to assess myocardial ischemia non-invasively. However its performance vs gated-SPECT and in sub-populations is not fully established. The goal was to compare in a multicenter setting the diagnostic performance of perfusion-CMR and gated-SPECT for the detection of CAD in various populations using conventional x-ray coronary angiography (CXA) as the standard of reference. Methods In 33 centers (in US and Europe) 533 patients, eligible for CXA or SPECT, were enrolled in this multivendor trial. SPECT and CXA were performed within 4 weeks before or after CMR in all patients. Prevalence of CAD in the sample was 49% and 515 patients received MR contrast medium. Drop-out rates for CMR and SPECT were 5.6% and 3.7%, respectively (ns). The study was powered for the primary endpoint of non-inferiority of CMR vs SPECT for both, sensitivity and specificity for the detection of CAD (using a single-threshold reading), the results for the primary endpoint were reported elsewhere. In this article secondary endpoints are presented, i.e. the diagnostic performance of CMR versus SPECT in subpopulations such as multi-vessel disease (MVD), in men, in women, and in patients without prior myocardial infarction (MI). For diagnostic performance assessment the area under the receiver-operator-characteristics-curve (AUC) was calculated. Readers were blinded versus clinical data, CXA, and imaging results. Results The diagnostic performance (= area under ROC = AUC) of CMR was superior to SPECT (p = 0.0004, n = 425) and to gated-SPECT (p = 0.018, n = 253). CMR performed better than SPECT in MVD (p = 0.003 vs all SPECT, p = 0.04 vs gated-SPECT), in men (p = 0.004, n = 313) and in women (p = 0.03, n = 112) as well as in the non-infarct patients (p = 0.005, n = 186 in 1–3 vessel disease and p = 0.015, n = 140 in MVD). Conclusion

  4. Arterial Spin-Labeled Perfusion Combined with Segmentation Techniques to Evaluate Cerebral Blood Flow in White and Gray Matter of Children with Sickle Cell Anemia

    PubMed Central

    Helton, Kathleen J.; Paydar, Amir; Glass, John; Weirich, Eric M.; Hankins, Jane; Li, Chin-Shang; Smeltzer, Matthew P.; Wang, Winfred C.; Ware, Russell E.; Ogg, Robert J.

    2015-01-01

    Background Changes in cerebral perfusion are an important feature of the pathophysiology of sickle cell anemia (SCA); cerebrovascular ischemia occurs frequently and leads to neurocognitive deficits, silent infarcts, and overt stroke. Non-invasive MRI methods to measure cerebral blood flow (CBF) by arterial spin labeling (ASL) afford new opportunities to characterize disease- and therapy-induced changes in cerebral hemodynamics in patients with SCA. Recent studies have documented elevated gray matter (GM) CBF in untreated children with SCA, but no measurements of white matter (WM) CBF have been reported. Procedures Pulsed ASL with automated brain image segmentation-classification techniques were used to determine the CBF in GM, WM, and abnormal white matter (ABWM) of 21 children with SCA, 18 of whom were receiving hydroxyurea therapy. Results GM and WM CBF were highly associated (R2 =.76, p< 0.0001) and the GM to WM CBF ratio was 1.6 (95% confidence interval: 1.43-1.83). Global GM CBF in our treated cohort was 87 ± 24 mL/min/100 g, a value lower than previously reported in untreated patients with SCA. CBF was elevated in normal appearing WM (43 ± 14 mL/min/100 g) but decreased in ABWM (6 ± 12 mL/min/100 g), compared to published normal pediatric controls. Hemispheric asymmetry in CBF was noted in most patients. Conclusions These perfusion measurements suggest that hydroxyurea may normalize GM CBF in children with SCA, but altered perfusion in WM may persist. This novel combined approach for CBF quantification will facilitate prospective studies of cerebral vasculopathy in SCA, particularly regarding the effects of treatments such as hydroxyurea. PMID:18937311

  5. A novel technique for simultaneous whole-body and multi-organ decellularization: umbilical artery catheterization as a perfusion-based method in a sheep foetus model

    PubMed Central

    Kajbafzadeh, Abdol-Mohammad; Khorramirouz, Reza; Akbarzadeh, Aram; Sabetkish, Shabnam; Sabetkish, Nastaran; Saadat, Paria; Tehrani, Mona

    2015-01-01

    The aim of this study was to develop a method to generate multi-organ acellular matrices. Using a foetal sheep model have developed a method of systemic pulsatile perfusion via the umbilical artery which allows for simultaneous multi-organ decellularization. Twenty sheep foetuses were systemically perfused with Triton X-100 and sodium dodecyl sulphate. Following completion of the whole-body decellularization, multiple biopsy samples were taken from different parts of 21 organs to ascertain complete cell component removal in the preserved extracellular matrices. Both the natural and decellularized organs were subjected to several examinations. The samples were obtained from the skin, eye, ear, nose, throat, cardiovascular, respiratory, gastrointestinal, urinary, musculoskeletal, central nervous and peripheral nervous systems. The histological results depicted well-preserved extracellular matrix (ECM) integrity and intact vascular structures, without any evidence of residual cellular materials, in all decellularized bioscaffolds. Scanning electron microscope (SEM) and biochemical properties remained intact, similar to their age-matched native counterparts. Preservation of the collagen structure was evaluated by a hydroxyproline assay. Dense organs such as bone and muscle were also completely decellularized, with a preserved ECM structure. Thus, as shown in this study, several organs and different tissues were decellularized using a perfusion-based method, which has not been previously accomplished. Given the technical challenges that exist for the efficient generation of biological scaffolds, the current results may pave the way for obtaining a variety of decellularized scaffolds from a single donor. In this study, there have been unique responses to the single acellularization protocol in foetuses, which may reflect the homogeneity of tissues and organs in the developing foetal body. PMID:26031202

  6. Endothelium-dependent and BRL 34915-induced vasodilatation in rat isolated perfused mesenteric arteries: role of G-proteins, K+ and calcium channels.

    PubMed Central

    Adeagbo, A. S.; Malik, K. U.

    1990-01-01

    1. In the isolated perfused, noradrenaline (NA)-constricted mesenteric arteries of the rat, acetylcholine (0.003-1 nmol), histamine (0.01-10 nmol) and the calcium ionophore A23187 (0.01-1 nmol), caused endothelium-dependent vasodilatation while the vasodilatation by the K+ channel activator BRL 34915 (0.1-1 nmol) was independent of endothelium. 2. The guanylate cyclase inhibitor, methylene blue at 10 microM did not inhibit the action of any of the vasodilators but at 50 microM reduced the vasodilator effect of acetylcholine (ACh), histamine and A23187. 3. Infusion of ouabain or perfusion with K(+)-free or excess K+ (50 mM) Krebs solution reduced the vasodilator effect of ACh, histamine and A23187, suggesting the action of these agents involves, at least in part, activation of Na+/K(+)-ATPase. The vasodilator effect of BRL 34915 was not affected by ouabain, but abolished during perfusion with Krebs solution containing excess K+ or depleted of K+. 4. Five structurally distinct K+ channel blockers (apamin, crude scorpion venom, procaine, quinidine and tetraethylammonium) attenuated the vasodilator effect of ACh, histamine and A23187. The K+ channel blockers, except apamin and crude scorpion venom, also inhibited the vasodilatation produced by BRL 34915. 5. The vasodilator effect of ACh, histamine or A23187 was not altered in mesenteric vessels of pertussis toxin-treated rats, suggesting that the K+ channels associated with the endothelium-dependent vasodilator effect of these agents are either not coupled to G-proteins or are coupled to G-proteins that are insensitive to pertussis toxin.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2167732

  7. A novel technique for simultaneous whole-body and multi-organ decellularization: umbilical artery catheterization as a perfusion-based method in a sheep foetus model.

    PubMed

    Kajbafzadeh, Abdol-Mohammad; Khorramirouz, Reza; Akbarzadeh, Aram; Sabetkish, Shabnam; Sabetkish, Nastaran; Saadat, Paria; Tehrani, Mona

    2015-04-01

    The aim of this study was to develop a method to generate multi-organ acellular matrices. Using a foetal sheep model have developed a method of systemic pulsatile perfusion via the umbilical artery which allows for simultaneous multi-organ decellularization. Twenty sheep foetuses were systemically perfused with Triton X-100 and sodium dodecyl sulphate. Following completion of the whole-body decellularization, multiple biopsy samples were taken from different parts of 21 organs to ascertain complete cell component removal in the preserved extracellular matrices. Both the natural and decellularized organs were subjected to several examinations. The samples were obtained from the skin, eye, ear, nose, throat, cardiovascular, respiratory, gastrointestinal, urinary, musculoskeletal, central nervous and peripheral nervous systems. The histological results depicted well-preserved extracellular matrix (ECM) integrity and intact vascular structures, without any evidence of residual cellular materials, in all decellularized bioscaffolds. Scanning electron microscope (SEM) and biochemical properties remained intact, similar to their age-matched native counterparts. Preservation of the collagen structure was evaluated by a hydroxyproline assay. Dense organs such as bone and muscle were also completely decellularized, with a preserved ECM structure. Thus, as shown in this study, several organs and different tissues were decellularized using a perfusion-based method, which has not been previously accomplished. Given the technical challenges that exist for the efficient generation of biological scaffolds, the current results may pave the way for obtaining a variety of decellularized scaffolds from a single donor. In this study, there have been unique responses to the single acellularization protocol in foetuses, which may reflect the homogeneity of tissues and organs in the developing foetal body.

  8. Relations among impaired coronary flow reserve, left ventricular hypertrophy and thallium perfusion defects in hypertensive patients without obstructive coronary artery disease

    SciTech Connect

    Houghton, J.L.; Frank, M.J.; Carr, A.A.; von Dohlen, T.W.; Prisant, L.M. )

    1990-01-01

    Invasive Doppler catheter-derived coronary flow reserve, echocardiographic measurements of left ventricular hypertrophy and intravenous dipyridamole-limited stress thallium-201 scintigraphy were compared in 48 patients (40 were hypertensive or diabetic) with clinical ischemic heart disease and no or minor coronary artery disease. Abnormal vasodilator reserve (ratio less than 3:1) occurred in 50% of the study group and markedly abnormal reserve (less than or equal to 2:1) occurred in 27%. Coronary vasodilator reserve was significantly lower (2.2 +/- 0.8 versus 3.5 +/- 1.3, p = 0.003) and indexed left ventricular mass significantly higher (152.6 +/- 42.2 versus 113.6 +/- 24.0 g, p = 0.0007) in patients with a positive (n = 11) versus a negative (n = 32) thallium perfusion scan. Coronary flow reserve was linearly related in coronary basal flow velocity as follows: y = -0.17x + 4.59; r = -0.57; p = 0.00002. The decrement in flow reserve was not linearly related to the degree of left ventricular hypertrophy. Abnormal vasodilator reserve subsets found in hypertensive patients were defined on the basis of basal flow velocity, indexed left ventricular mass and clinical factors. In this series, diabetes did not cause a detectable additional decrement in flow reserve above that found with hypertension alone. These findings demonstrate that thallium perfusion defects are associated with depressed coronary vasodilator reserve in hypertensive patients without obstructive coronary artery disease. Left ventricular hypertrophy by indexed mass criteria is predictive of which hypertensive patients are likely to have thallium defects.

  9. Reversibility of retinal ischemia due to central retinal artery occlusion by hyperbaric oxygen

    PubMed Central

    Hadanny, Amir; Maliar, Amit; Fishlev, Gregory; Bechor, Yair; Bergan, Jacob; Friedman, Mony; Avni, Isaac; Efrati, Shai

    2017-01-01

    Purpose Ischemic retinal damage can be reversed by hyperbaric oxygen therapy (HBOT) as long as irreversible infarction damage has not developed. However, the time window till irreversible damage develops is still unknown. The study aim was to evaluate the effect of HBOT and determine possible markers for irreversible retinal damage. Materials and methods Retrospective analysis of 225 patients treated with HBOT for central retinal artery occlusion (CRAO) in 1999–2015. One hundred and twenty-eight patients fulfilled inclusion/exclusion criteria: age >18 years, symptoms <20 hours, and best-corrected visual acuity (BCVA) <0.5 logMAR. Results Time delay from symptoms to treatment was 7.8±3.8 hours. The BCVA was significantly improved after HBOT, from 2.14±0.50 to 1.61±0.78 (P<0.0001). The proportion of patients with clinically meaningful visual improvement was significantly higher in patients without cherry-red spot (CRS) compared to patients with CRS at presentation (86.0% vs 57.6%, P<0.0001). The percentage of patients with final BCVA better than 1.0 was also significantly higher in patients without CRS vs patients with CRS at presentation (61.0% vs 7.1%, P<0.0001). There was no correlation between CRS and the time from symptoms. HBOT was found to be safe, and only 5.5% of patients had minor, reversible, adverse events. Conclusion HBOT is an effective treatment for non-arteritic CRAO as long as CRS has not formed. The fundus findings, rather than the time delay, should be used as a marker for irreversible damage. PMID:28096655

  10. The Reverse Superficial Sural Artery Flap Revisited for Complex Lower Extremity and Foot Reconstruction

    PubMed Central

    Sugg, Kristoffer B.; Schaub, Timothy A.; Concannon, Matthew J; Cederna, Paul S.

    2015-01-01

    Background: Soft-tissue defects of the distal lower extremity and foot present significant challenges to the reconstructive surgeon. The reverse superficial sural artery flap (RSSAF) is a popular option for many of these difficult wounds. Our initial experience with this flap at multiple institutions resulted in a 50% failure rate, mostly because of critical venous congestion. To overcome this, we have modified our operative technique, which has produced a more reliable flap. Methods: All patients reconstructed with an RSSAF between May 2002 and September 2013 were retrospectively reviewed. In response to a high rate of venous congestion in an early group of patients, we adopted a uniform change in operative technique for a late group of patients. A key modification was an increase in pedicle width to at least 4 cm. Outcomes of interest included postoperative complications and limb salvage rate. Results: Twenty-seven patients were reconstructed with an RSSAF (n = 12 for early group, n = 15 for late group). Salvage rate in the early group was 50% compared with 93% in the late group (P = 0.02). Postoperative complications (75% vs. 67%, P = 0.70) were similar between groups. Venous congestion that required leech therapy was 42% in the early group (n = 5) and 0% in the late group (P = 0.01). Conclusions: Venous congestion greatly impairs the survival of the RSSAF. A pedicle width of at least 4 cm is recommended to maintain venous drainage and preserve flap viability. PMID:26495232

  11. Deleterious Effects of Intra-arterial Administration of Particulate Steroids on Microvascular Perfusion in a Mouse Model.

    PubMed

    Laemmel, Elisabeth; Segal, Nicolas; Mirshahi, Massoud; Azzazene, Dalel; Le Marchand, Sylvie; Wybier, Marc; Vicaut, Eric; Laredo, Jean-Denis

    2016-06-01

    Purpose To determine the in vivo effects of several particulate steroids on microvascular perfusion by using intravital microscopy in a mice model and to investigate the in vitro interactions between these particulate steroids and red blood cells (RBCs). Materials and Methods The study was conducted in agreement with the guidelines of the National Committee of Ethic Reflection on Animal Experimentation. By using intravital microscopy of mouse cremaster muscle, the in vivo effects of several particulate steroids on microvascular perfusion were assessed. Four to five mice were allocated to each of the following treatment groups: saline solution, dexamethasone sodium phosphate, a nonparticulate steroid, and the particulate steroids cortivazol, methylprednisolone, triamcinolone, and prednisolone. By using in vitro blood microcinematography and electron microscopy, the interactions between these steroids and human RBCs were studied. All results were analyzed by using nonparametric tests. Results With prednisolone, methylprednisolone, or triamcinolone, blood flow was rapidly and completely stopped in all the arterioles and venules (median RBC velocity in first-order arterioles, 5 minutes after administration was zero for these three groups) compared with a limited effect in mice treated with saline, dexamethasone, and cortivazol (20.3, 21.3, and 27.5 mm/sec, respectively; P < .003). This effect was associated with a large decrease in the functional capillary density (4.21, 0, and 0 capillaries per millimeter for methylprednisolone, triamcinolone, or prednisolone, respectively, vs 21.0, 21.4, and 19.1 capillaries per millimeter in mice treated with saline, dexamethasone, and cortivazol, respectively; P < .003). This was because of the rapid formation of RBC aggregates. However, no change in microvascular perfusion was associated with administration of cortivazol or dexamethasone. In vitro experiments confirmed the formation of RBC aggregates associated with the

  12. Automatic measurement of contrast bolus distribution in carotid arteries using a C-arm angiography system to support interventional perfusion imaging

    NASA Astrophysics Data System (ADS)

    Fieselmann, Andreas; Ganguly, Arundhuti; Yu, Deuerling-Zheng; Boese, Jan; Hornegger, Joachim; Fahrig, Rebecca

    2011-03-01

    Brain perfusion CT using a C-arm angiography system capable of CT-like imaging could optimize patient treatment during stroke therapy procedures. For this application, an intra-arterial contrast bolus injection at the aortic arch could be used provided that the location of the injection catheter enables uniform distribution of the bolus into the two common carotid arteries (CCA). In this work, we present a novel method to support optimal injection catheter placement by providing additional quantitative information about the distribution of the contrast bolus into the CCAs. Our fully automatic method uses 2-D digital subtraction angiography (DSA) images following a test bolus injection. It segments both CCAs and computes the relative contrast distribution. We have tested the method in DSA data sets from 5 healthy pigs and our method achieved successful segmentation of both CCAs in all data sets. The results showed that the contrast is uniformly distributed (mean relative difference less or equal than 10%) if the injection location is properly chosen.

  13. Prognostic value of dobutamine stress myocardial perfusion echocardiography in patients with known or suspected coronary artery disease and normal left ventricular function

    PubMed Central

    Mattoso, Angele A. A.; Tsutsui, Jeane M.; Kowatsch, Ingrid; Cruz, Vitória Y. L.; Sbano, João C. N.; Ribeiro, Henrique B.; Kalil Filho, Roberto; Porter, Thomas R.; Mathias, Wilson

    2017-01-01

    Objective We sought to determine the prognostic value of qualitative and quantitative analysis obtained by real-time myocardial perfusion echocardiography (RTMPE) in patients with known or suspected coronary artery disease (CAD). Background Quantification of myocardial blood flow reserve (MBFR) in patients with CAD using RTMPE has been demonstrated to further improve accuracy over the analysis of wall motion (WM) and qualitative analysis of myocardial perfusion (QMP). Methods From March 2003 to December 2008, we prospectively studied 168 patients with normal left ventricular function (LVF) who underwent dobutamine stress RTMPE. The replenishment velocity reserve (β) and MBFR were derived from RTMPE. Acute coronary events were: cardiac death, myocardial infarction and unstable angina with need for urgent coronary revascularization. Results During a median follow-up of 34 months (5 days to 6.9 years), 17 acute coronary events occurred. Abnormal β reserve in ≥2 coronary territories was the only independent predictor of events hazard ratio (HR) = 21, 95% CI = 4.5–99; p<0.001). Both, abnormal β reserve and MBFR added significant incremental value in predicting events over qualitative analysis of WM and MP (χ2 = 6.6 and χ2 = 24.6, respectively; p = 0.001 and χ2 = 6.6 and χ2 = 15.5, respectively; p = 0.012, respectively). When coronary angiographic data was added to the multivariate analysis model, β reserve remained the only predictor of events with HR of 21.0 (95% CI = 4.5–99); p<0.001. Conclusion Quantitative dobutamine stress RTMPE provides incremental prognostic information over clinical variables, qualitative analysis of WM and MP, and coronary angiography in predicting acute coronary events. PMID:28234978

  14. Rapid detection of the addition of soybean proteins to cheese and other dairy products by reversed-phase perfusion chromatography.

    PubMed

    García, M C; Marina, M L

    2006-04-01

    The undeclared addition of soybean proteins to milk products is forbidden and a method is needed for food control and enforcement. This paper reports the development of a chromatographic method for routine analysis enabling the detection of the addition of soybean proteins to dairy products. A perfusion chromatography column and a linear binary gradient of acetonitrile-water-0.1% (v/v) trifluoroacetic acid at a temperature of 60 degrees C were used. A very simple sample treatment consisting of mixing the sample with a suitable solvent (Milli-Q water or bicarbonate buffer (pH=11)) and centrifuging was used. The method enabled the separation of soybean proteins from milk proteins in less than 4 min (at a flow-rate of 3 ml/min). The method has been successfully applied to the detection of soybean proteins in milk, cheese, yogurt, and enteral formula. The correct quantitation of these vegetable proteins has also been possible in milk adulterated at origin with known sources of soybean proteins. The application of the method to samples adulterated at origin also leads to interesting conclusions as to the effect of the processing conditions used for the preparation of each dairy product on the determination of soybean proteins.

  15. The Reverse-Flow Facial Artery Buccinator Flap for Skull Base Reconstruction: Key Anatomical and Technical Considerations.

    PubMed

    Farzal, Zainab; Lemos-Rodriguez, Ana M; Rawal, Rounak B; Overton, Lewis J; Sreenath, Satyan B; Patel, Mihir R; Zanation, Adam M

    2015-12-01

    Objective To highlight key anatomical and technical considerations for facial artery identification, and harvest and transposition of the facial artery buccinator (FAB) flap to facilitate its future use in anterior skull base reconstruction. Only a few studies have evaluated the reverse-flow FAB flap for skull base defects. Design Eight FAB flaps were raised in four cadaveric heads and divided into thirds; the facial artery's course at the superior and inferior borders of the flap was measured noting in which incisional third of the flap it laid. The flap's reach to the anterior cranial fossa, sella turcica, clival recess, and contralateral cribriform plate were studied. A clinical case and operative video are also presented. Results The facial artery had a near vertical course and stayed with the middle (⅝) or posterior third (⅜) of the flap in the inferior and superior incisions. Seven of eight flaps covered the sellar/planar regions. Only four of eight flaps covered the contralateral cribriform region. Lastly, none reached the middle third of the clivus. Conclusions The FAB flap requires an understanding of the facial artery's course, generally seen in the middle third of the flap, and is an appropriate alternative for sellar/planar and ipsilateral cribriform defects.

  16. Reversibility of High-Grade Atrioventricular Block with Revascularization in Coronary Artery Disease without Infarction: A Literature Review

    PubMed Central

    Cardoso, Rhanderson; Alfonso, Carlos E.; Coffey, James O.

    2016-01-01

    Complete atrioventricular (AV) block is known to be reversible in some cases of acute inferior wall myocardial infarction (MI). The reversibility of high-grade AV block in non-MI coronary artery disease (CAD), however, is rarely described in the literature. Herein we perform a literature review to assess what is known about the reversibility of high-grade AV block after right coronary artery revascularization in CAD patients who present without an acute MI. To illustrate this phenomenon we describe a case of 2 : 1 AV block associated with unstable angina, in which revascularization resulted in immediate and durable restoration of 1 : 1 AV conduction, thereby obviating the need for permanent pacemaker implantation. The literature review suggests two possible explanations: a vagally mediated response or a mechanism dependent on conduction system ischemia. Due to the limited understanding of AV block reversibility following revascularization in non-acute MI presentations, it remains difficult to reliably predict which patients presenting with high-grade AV block in the absence of MI may have the potential to avoid permanent pacemaker implantation via coronary revascularization. We thus offer this review as a potential starting point for the approach to such patients. PMID:26925272

  17. Detection of coronary artery disease using MR imaging with dipyridamole infusion

    SciTech Connect

    Pennell, D.J.; Underwood, S.R.; Longmore, D.B. )

    1990-03-01

    Exercise testing in the magnetic resonance (MR) scanner is difficult because of space restriction and movement artefact, which limit its use in the investigation of patients with suspected coronary artery disease. Pharmacological stress, however, can be used as a substitute for exercise. Therefore, a patient with angina underwent MR ventricular wall motion studies before and after intravenous dipyridamole. Reversible abnormal regional contraction of the myocardium was demonstrated and correlated with a reversible perfusion defect on subsequent thallium myocardial perfusion imaging and a blocked artery at coronary angiography. A clinically useful investigative procedure may be developed.

  18. Quantitative severity of stress thallium-201 myocardial perfusion single-photon emission computed tomography defects in one-vessel coronary artery disease.

    PubMed

    Matzer, L; Kiat, H; Van Train, K; Germano, G; Papanicolaou, M; Silagan, G; Eigler, N; Maddahi, J; Berman, D S

    1993-08-01

    The relation between the quantitative myocardial perfusion defect severity of exercise thallium-201 single-photon emission computed tomography (SPECT) and the quantitative degree of coronary stenosis was examined in 18 patients with 1-vessel disease (> or = 50% diameter stenosis), and abnormal thallium-201 SPECT. A total of 26 vessels were analyzed. Thallium-201 SPECT quantitative defect severity score was derived by summing the number of pixels in a coronary territory in which counts fell below the normal mean and multiplied by the number of SDs by which they fell below the normal mean. The thallium-201 defect severity score was significantly (p < 0.001) related to the maximal percent luminal diameter narrowing (r = 0.93), percent area narrowing (r = 0.89), absolute stenotic area (r = 0.79), and absolute stenotic diameter (r = 0.81). As expected, the strongest relation between thallium-201 defect severity and quantitative angiographic indexes was in the low and high ranges of coronary stenosis, with more variability and lower correlation coefficients (percent diameter: r = 0.75, p < 0.02, percent area stenosis: r = 0.63, p < 0.05) in the middle ranges (50 to 80% diameter stenosis). This observation is likely to be due to the complex flow characteristics across stenotic lesions. The findings suggest that in a select population, thallium-201 defect severity is potentially useful for noninvasive characterization of the functional severity of coronary artery stenosis and may complement coronary angiography in predicting functionally significant stenosis.

  19. The predictive value of chronic kidney disease for assessing cardiovascular events under consideration of pretest probability for coronary artery disease in patients who underwent stress myocardial perfusion imaging.

    PubMed

    Furuhashi, Tatsuhiko; Moroi, Masao; Joki, Nobuhiko; Hase, Hiroki; Masai, Hirofumi; Kunimasa, Taeko; Fukuda, Hiroshi; Sugi, Kaoru

    2013-02-01

    Pretest probability of coronary artery disease (CAD) facilitates diagnosis and risk stratification of CAD. Stress myocardial perfusion imaging (MPI) and chronic kidney disease (CKD) are established major predictors of cardiovascular events. However, the role of CKD to assess pretest probability of CAD has been unclear. This study evaluates the role of CKD to assess the predictive value of cardiovascular events under consideration of pretest probability in patients who underwent stress MPI. Patients with no history of CAD underwent stress MPI (n = 310; male = 166; age = 70; CKD = 111; low/intermediate/high pretest probability = 17/194/99) and were followed for 24 months. Cardiovascular events included cardiac death and nonfatal acute coronary syndrome. Cardiovascular events occurred in 15 of the 310 patients (4.8 %), but not in those with low pretest probability which included 2 CKD patients. In patients with intermediate to high pretest probability (n = 293), multivariate Cox regression analysis identified only CKD [hazard ratio (HR) = 4.88; P = 0.022) and summed stress score of stress MPI (HR = 1.50; P < 0.001) as independent and significant predictors of cardiovascular events. Cardiovascular events were not observed in patients with low pretest probability. In patients with intermediate to high pretest probability, CKD and stress MPI are independent predictors of cardiovascular events considering the pretest probability of CAD in patients with no history of CAD. In assessing pretest probability of CAD, CKD might be an important factor for assessing future cardiovascular prognosis.

  20. Assessment of Heart Rate Recovery with GATED-Myocardial Perfusion Scintigraphy Outcome in Patients with Coronary Artery Disease: A Retrospective Study and Institutional Experience

    PubMed Central

    Tan, Yusuf Ziya; Özdemir, Semra; Altun, Burak; Çelik, Fatmanur

    2016-01-01

    Objective: This study aimed to investigate the effects of assessment with myocardial perfusion scintigraphy (MPS) and heart rate recovery (HRrec) measurements in combination to evaluate the current status of patients with a diagnosis or suspicion of coronary artery disease (CAD). Methods: A total of 350 patients were included in the study. CAD group consisted of 200 patients with stable angina pectoris and a known history of CAD, while the control group consisted of 150 patients with suspicious stress test who had no history of known CAD. In order to calculate the HRrec index, the treadmill exercise test was performed in all patients according to the Bruce protocol. The MPS results were evaluated for the presence or absence of myocardial ischemia and infarction by visual and quantitative (summed stress score and summed difference score) assessments. Results: When the MPS results and HRrec were evaluated together, there was no statistically significant difference in the non-CAD group. But, when GATED-MPS was evaluated alone in the triple-vessel patient group, 27 (36%) patients were found to be normal while evaluated with HRrec, four (5.3%) patients were found to be normal. Conclusion: HRrec measurements obtained during stress MPS is important in patient evaluation. Therefore, evaluation of MPS results and HRrec measurements together may provide a more accurate estimation of possible presence of CAD in patients. PMID:27751974

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

    SciTech Connect

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

    1984-08-01

    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.

  2. Reverse redistribution of thallium-201 detected by SPECT imaging after dipyridamole in angina pectoris

    SciTech Connect

    Popma, J.J.; Smitherman, T.C.; Walker, B.S.; Simon, T.R.; Dehmer, G.J. )

    1990-05-15

    Reverse redistribution refers to a thallium-201 perfusion defect that develops or becomes more evident on delayed imaging compared with the initial image immediately after stress. To determine the diagnostic importance of reverse redistribution after intravenous dipyridamole, thallium-201 single photon emission computed tomography and quantitative coronary arteriography were performed in 90 men with angina pectoris. Of the 250 myocardial segments analyzed, reverse redistribution was present in 17 (7%). Minimal coronary cross-sectional area in proximal vessel segments was less than or equal to 2.0 mm2 more often in regions with transient perfusion abnormalities than in regions with reverse redistribution (66 vs 29%, p less than 0.05). Compared with regions exhibiting transient perfusion abnormalities, regions with reverse redistribution had larger proximal arterial diameters (1.9 +/- 1.1 vs 1.3 +/- 1.1 mm, p less than 0.001) and cross-sectional areas (3.9 +/- 3.1 vs 2.2 +/- 2.6 mm2, p less than 0.001). Coronary artery dimensions and relative stenosis severity did not differ between those regions with normal perfusion and those with reverse redistribution. Reverse redistribution detected by thallium-201 single photon emission computed tomographic imaging after dipyridamole is uncommon, appears to occur as frequently in normal subjects as in patients undergoing coronary arteriography and does not indicate the presence of severe coronary artery disease.

  3. Arterial Spin-Labeling MRI Can Identify the Presence and Intensity of Collateral Perfusion in Patients With Moyamoya Disease

    PubMed Central

    Zaharchuk, Greg; Do, Huy M.; Marks, Michael P.; Rosenberg, Jarrett; Moseley, Michael E.; Steinberg, Gary K.

    2011-01-01

    Background and Purpose Determining the presence and adequacy of collateral blood flow is important in cerebrovascular disease. Therefore, we explored whether a noninvasive imaging modality, arterial spin labeling (ASL) MRI, could be used to detect the presence and intensity of collateral flow using digital subtraction angiography (DSA) and stable xenon CT cerebral blood flow as gold standards for collaterals and cerebral blood flow, respectively. Methods ASL and DSA were obtained within 4 days of each other in 18 patients with Moyamoya disease. Two neurointerventionalists scored DSA images using a collateral grading scale in regions of interest corresponding to ASPECTS methodology. Two neuroradiologists similarly scored ASL images based on the presence of arterial transit artifact. Agreement of ASL and DSA consensus scores was determined, including kappa statistics. In 15 patients, additional quantitative xenon CT cerebral blood flow measurements were performed and compared with collateral grades. Results The agreement between ASL and DSA consensus readings was moderate to strong, with a weighted kappa value of 0.58 (95% confidence interval, 0.52–0.64), but there was better agreement between readers for ASL compared with DSA. Sensitivity and specificity for identifying collaterals with ASL were 0.83 (95% confidence interval, 0.77–0.88) and 0.82 (95% confidence interval, 0.76–0.87), respectively. Xenon CT cerebral blood flow increased with increasing DSA and ASL collateral grade (P<0.05). Conclusions ASL can noninvasively predict the presence and intensity of collateral flow in patients with Moyamoya disease using DSA as a gold standard. Further study of other cerebrovascular diseases, including acute ischemic stroke, is warranted. PMID:21799169

  4. Three-dimensional whole-brain perfusion quantification using pseudo-continuous arterial spin labeling MRI at multiple post-labeling delays: accounting for both arterial transit time and impulse response function.

    PubMed

    Qin, Qin; Huang, Alan J; Hua, Jun; Desmond, John E; Stevens, Robert D; van Zijl, Peter C M

    2014-02-01

    Measurement of the cerebral blood flow (CBF) with whole-brain coverage is challenging in terms of both acquisition and quantitative analysis. In order to fit arterial spin labeling-based perfusion kinetic curves, an empirical three-parameter model which characterizes the effective impulse response function (IRF) is introduced, which allows the determination of CBF, the arterial transit time (ATT) and T(1,eff). The accuracy and precision of the proposed model were compared with those of more complicated models with four or five parameters through Monte Carlo simulations. Pseudo-continuous arterial spin labeling images were acquired on a clinical 3-T scanner in 10 normal volunteers using a three-dimensional multi-shot gradient and spin echo scheme at multiple post-labeling delays to sample the kinetic curves. Voxel-wise fitting was performed using the three-parameter model and other models that contain two, four or five unknown parameters. For the two-parameter model, T(1,eff) values close to tissue and blood were assumed separately. Standard statistical analysis was conducted to compare these fitting models in various brain regions. The fitted results indicated that: (i) the estimated CBF values using the two-parameter model show appreciable dependence on the assumed T(1,eff) values; (ii) the proposed three-parameter model achieves the optimal balance between the goodness of fit and model complexity when compared among the models with explicit IRF fitting; (iii) both the two-parameter model using fixed blood T1 values for T(1,eff) and the three-parameter model provide reasonable fitting results. Using the proposed three-parameter model, the estimated CBF (46 ± 14 mL/100 g/min) and ATT (1.4 ± 0.3 s) values averaged from different brain regions are close to the literature reports; the estimated T(1,eff) values (1.9 ± 0.4 s) are higher than the tissue T1 values, possibly reflecting a contribution from the microvascular arterial blood compartment.

  5. Long-term successful outcome of severe hand ischemia using arterialization with reversal of venous flow: case report.

    PubMed

    Chloros, George D; Li, Zhongyu; Koman, L Andrew

    2008-09-01

    The management of unreconstructible vascular lesions in the hand is a challenge with limited options for treatment. After 22 years of hand ischemia, involving management with reverse interpositional vein grafting, periarterial sympathectomy, and partial finger amputations, a 62-year-old man underwent arterialization of the venous system of the hand for unreconstructible distal vascular lesions as a salvage procedure. At 7-year follow-up, the patient is pain-free with good functional and health-related quality of life outcomes and no further amputations. This procedure may be considered as a salvage alternative to prevent additional amputation in selected patients.

  6. Simultaneous laser Doppler flowmetry and arterial spin labeling MRI for measurement of functional perfusion changes in the cortex.

    PubMed

    He, Jiabao; Devonshire, Ian M; Mayhew, John E W; Papadakis, Nikos G

    2007-02-15

    This study compares laser Doppler flowmetry (LDF) and arterial spin labeling (ASL) for the measurement of functional changes in cerebral blood flow (CBF). The two methods were applied concurrently in a paradigm of electrical whisker stimulation in the anaesthetised rat. Multi-channel LDF was used, with each channel corresponding to different fiber separation (and thus measurement depth). Continuous ASL was applied using separate imaging and labeling coils at 3 T. Careful experimental set up ensured that both techniques recorded from spatially concordant regions of the barrel cortex, where functional responses were maximal. Strong correlations were demonstrated between CBF changes measured by each LDF channel and ASL in terms of maximum response magnitude and response time-course within a 6-s-long temporal resolution imposed by ASL. Quantitatively, the measurements of the most superficial LDF channels agreed strongly with those of ASL, whereas the deeper LDF channels underestimated consistently the ASL measurement. It was thus confirmed that LDF quantifies CBF changes consistently at a superficial level, and for this case the two methods provided concordant measures of functional CBF changes, despite their essentially different physical principles and spatiotemporal characteristics.

  7. Embolisation of the Gastroduodenal Artery is Not Necessary in the Presence of Reversed Flow Before Yttrium-90 Radioembolisation

    SciTech Connect

    Daghir, Ahmed A.; Gungor, Hatice; Haydar, Ali A.; Wasan, Harpreet S.; Tait, Nicholas P.

    2012-08-15

    Introduction: The gastroduodenal artery (GDA) is usually embolised to avoid nontarget dispersal before yttrium-90 (Y{sup 90}) radioembolisation to treat liver metastases. In a minority of patients, there is retrograde flow in the GDA. The purpose of this study was to determine if there is any increased risk from maintaining a patent GDA in patients with reversed flow. Materials and Methods: A retrospective review was performed of all patients undergoing Y{sup 90} radioembolisation at our institution. The incidence of toxicities arising from nontarget radioembolisation by way of the GDA (gastric/duodenal ulceration, gastric/duodenal bleeding, and pancreatitis) and death occurring within 2 months of treatment were compared between the reversed and the antegrade GDA groups. Results: Ninety-two patients underwent preliminary angiography. Reversed GDA flow was found on angiography in 14.1% of cases; the GDA was not embolised in these patients. The GDA was coiled in 55.7% of patients with antegrade GDA flow to prevent inadvertent dispersal of radioembolic material. There was no increased toxicity related to nontarget dispersal by way of the GDA, or increased early mortality, in patients with reversed GDA flow (P > 0.05). Conclusion: In patients with reversed GDA flow, maintenance of a patent GDA before administration of Y{sup 90} radioembolisation does not increase the risk of toxicity from nontarget dispersal. Therapeutic injection, with careful monitoring to identify early vascular stasis, may be safely performed beyond the origin of the patent GDA. A patent GDA with reversed flow provides forward drive for infused particles and may allow alternative access to the hepatic circulation.

  8. Impact of Gender on the Prognostic Value of Coronary Artery Calcium in Symptomatic Patients With Normal Single-Photon Emission Computed Tomography Myocardial Perfusion.

    PubMed

    Engbers, Elsemiek M; Timmer, Jorik R; Ottervanger, Jan Paul; Mouden, Mohamed; Knollema, Siert; Jager, Pieter L

    2016-12-01

    The coronary artery calcium (CAC) score provides independent prognostic value on top of single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). We sought to determine whether the prognostic value of the CAC score in patients with normal SPECT MPI is gender specific. We studied 3,705 consecutive symptomatic patients without a history of coronary artery disease with normal SPECT MPI. All patients underwent concomitant CAC scoring, which was categorized as CAC score 0, 1 to 99, 100 to 399, 400 to 999, or ≥1,000. Major adverse cardiac events were defined as revascularization, nonfatal myocardial infarction, or all-cause mortality. The median CAC score was 9 in women (interquartile range 0 to 113) and 47 in men (interquartile range 1 to 307, p <0.001). The annual event rate was lower in women than in men (1.6% and 2.7%, respectively, p <0.001). When stratified by CAC score, annual event rates were similar (for women and men, respectively: CAC score 0, 0.6% and 0.5%, p = 0.95; CAC score 1 to 99, 0.9% and 1.2%, p = 0.45; CAC score 100 to 399, 2.7% and 3.8%, p = 0.23; CAC score 400 to 999, 3.8% and 5.3%, p = 0.34; CAC score ≥1,000, 8.4% and 8.7%, p = 0.99). The CAC score was an independent predictor of major adverse cardiac events in both genders (CAC score ≥1,000: hazard ratio for women 8.5, 95% confidence interval 4.0 to 18.1; hazard ratio for men 14.8, 95% confidence interval 5.3 to 41.1). In conclusion, risk for events is similar for both genders when stratified by CAC score, wherein a high CAC score carries a high risk for events despite normal SPECT MPI. Our findings do not reveal a gender-specific prognostic value of the CAC score.

  9. SPECT myocardial perfusion imaging as an adjunct to coronary calcium score for the detection of hemodynamically significant coronary artery stenosis

    PubMed Central

    2012-01-01

    Background Coronary artery calcifications (CAC) are markers of coronary atherosclerosis, but do not correlate well with stenosis severity. This study intended to evaluate clinical situations where a combined approach of coronary calcium scoring (CS) and nuclear stress test (SPECT-MPI) is useful for the detection of relevant CAD. Methods Patients with clinical indication for invasive coronary angiography (ICA) were included into our study during 08/2005-09/2008. At first all patients underwent CS procedure as part of the study protocol performed by either using a multidetector computed tomography (CT) scanner or a dual-source CT imager. CAC were automatically defined by dedicated software and the Agatston score was semi-automatically calculated. A stress-rest SPECT-MPI study was performed afterwards and scintigraphic images were evaluated quantitatively. Then all patients underwent ICA. Thereby significant CAD was defined as luminal stenosis ≥75% in quantitative coronary analysis (QCA) in ≥1 epicardial vessel. To compare data lacking Gaussian distribution an unpaired Wilcoxon-Test (Mann–Whitney) was used. Otherwise a Students t-test for unpaired samples was applied. Calculations were considered to be significant at a p-value of <0.05. Results We consecutively included 351 symptomatic patients (mean age: 61.2±12.3 years; range: 18–94 years; male: n=240) with a mean Agatston score of 258.5±512.2 (range: 0–4214). ICA verified exclusion of significant CAD in 66/67 (98.5%) patients without CAC. CAC was detected in remaining 284 patients. In 132/284 patients (46.5%) with CS>0 significant CAD was confirmed by ICA, and excluded in 152/284 (53.5%) patients. Sensitivity for CAD detection by CS alone was calculated as 99.2%, specificity was 30.3%, and negative predictive value was 98.5%. An additional SPECT in patients with CS>0 increased specificity to 80.9% while reducing sensitivity to 87.9%. Diagnostic accuracy was 84.2%. Conclusions In patients without CS=0

  10. The Number of Perforators Included in Reversed Flow Posterior Interosseous Artery Flap: Does It Affect the Incidence of Venous Congestion?

    PubMed Central

    Shaker, Ayman A.; Elbarbary, Amir S.; Sayed, Mohamed A.; Elghareeb, Mohamed A.

    2016-01-01

    Background: The purpose of this study is to decrease the incidence of venous congestion occurring in the reversed flow posterior interosseous artery flap used for coverage of hand defects. Methods: This may be achieved by studying the incidence of venous congestion in flaps including only 1 perforator and comparing the results with others including more than 1 perforator both in small and large sized flaps. Results: This study showed that inclusion of only 1 perforator in the flap decreased the incidence of venous congestion with complete flap loss in flaps to 5%. Also, it decreased the incidence of venous congestion with partial flap loss in flaps to 10%. Conclusions: The small sized reversed flow posterior interosseous artery flap should be less than 40 cm2 and should include only 1 perforator to decrease the incidence of venous congestion with partial and complete loss of the flap. The level of evidence for this study is the type II prospective comparative study. PMID:28293513

  11. Thallium-201 myocardial perfusion imaging in myocarditis

    SciTech Connect

    Tamaki, N.; Yonekura, Y.; Kadota, K.; Kambara, H.; Torizuka, K.

    1985-08-01

    TI-201 myocardial perfusion imaging was performed in six patients with clinically documented myocarditis. Each case manifested electrocardiographic abnormalities with elevation of serum cardiac enzymes and no significant stenosis of the coronary arteries observed on angiogram. Resting TI-201 images were visually assessed by three observers. Focal perfusion defects were observed in three cases (50%), among which two showed multiple perfusion defects. Emission computed tomography using TI-201 clearly delineated multifocal lesions in the first case. On the other hand, no significant perfusion defects were noted in the remaining three cases. Thus, myocarditis should be considered as one of the disease entities that may produce perfusion defects on TI-201 myocardial imaging.

  12. Single Coronary Artery with Aortic Regurgitation

    SciTech Connect

    Katsetos, Manny C. Toce, Dale T.

    2003-11-15

    An isolated single coronary artery can be associated with normal life expectancy; however, patients are at an increased risk of sudden death. A case is reported of a 54-year-old man with several months of chest pressure with activity. On exercise Sestamibi stress testing, the patient developed a hypotensive response with no symptoms and minimal electrocardiographic changes. Nuclear scanning demonstrated reversible septal and lateral perfusion defects consistent with severe ischemia. Coronary angiography revealed a single coronary artery with the right coronary artery arising from the left main. There were high-grade stenotic lesions in the left anterior descending and circumflex arteries with only moderate atherosclerotic disease in the right coronary artery. An aortogram showed 2-3+ aortic regurgitation, with an ejection fraction of 45% on ventriculography. The patient underwent four-vessel revascularization and aortic valve replacement and did well postoperatively.

  13. Harmonic analysis of perfusion pumps.

    PubMed

    Dougherty, F Carroll; Donovan, F M; Townsley, Mary I

    2003-12-01

    The controversy over the use of nonpulsatile versus pulsatile pumps for maintenance of normal organ function during ex vivo perfusion has continued for many years, but resolution has been limited by lack of a congruent mathematical definition of pulsatility. We hypothesized that the waveform frequency and amplitude, as well as the underlying mean distending pressure are all key parameters controlling vascular function. Using discrete Fourier Analysis, our data demonstrate the complexity of the pulmonary arterial pressure waveform in vivo and the failure of commonly available perfusion pumps to mimic in vivo dynamics. In addition, our data show that the key harmonic signatures are intrinsic to the perfusion pumps, are similar for flow and pressure waveforms, and are unchanged by characteristics of the downstream perfusion circuit or perfusate viscosity.

  14. Reversals.

    ERIC Educational Resources Information Center

    National Center on Educational Media and Materials for the Handicapped, Columbus, OH.

    Selected from the National Instructional Materials Information System (NIMIS)--a computer based on-line interactive retrieval system on special education materials--the bibliography covers nine materials for remediating reversals in handicapped students at the early childhood and elementary levels. Entries are presented in order of NIMIS accession…

  15. Myocardial perfusion with rubidium-82. III. Theory relating severity of coronary stenosis to perfusion deficit

    SciTech Connect

    Mullani, N.A.

    1984-11-01

    The relation between the quantitative perfusion deficit, as measured by emission computerized tomography, and the severity of coronary artery stenosis is important for the noninvasive clinical evaluation of coronary artery disease in man. Positron emission tomography allows direct noninvasive measurement of myocardial perfusion and quantification of the size of the perfusion defect. Given this important imformation, a mathematical model has been derived to gauge the severity of a coronary stenosis from quantitative perfusion measurements in the normal and poststenotic regions of the heart. The theoretical basis is presented for relating regional myocardial perfusion and regional perfusion resistance to total, coronary blood flow and resistance at normal resting flow and during maximal coronary vasodilation. The concept of perfusion reserve is presented as a clinical measure of the severity of a stenosis.

  16. Predictive values of diffusion-weighted imaging and perfusion-weighted imaging in evaluating the efficacy of transcatheter arterial chemoembolization for hepatocellular carcinoma

    PubMed Central

    Lin, Min; Tian, Man-Man; Zhang, Wei-Ping; Xu, Li; Jin, Ping

    2016-01-01

    This study explored the predictive values of diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) in evaluating the efficacy of transcatheter arterial chemoembolization (TACE) for patients with hepatocellular carcinoma (HCC). A total of 118 HCC patients treated with TACE were selected from April 2013 to November 2015. T1-weighted imaging (T1WI)/T2-weighted imaging (T2WI), DWI, and PWI were performed on all patients before and after TACE. Efficacy was evaluated according to modified Response Evaluation Criteria in Solid Tumors 1.1. Receiver operating characteristic curve was used to evaluate the diagnostic power of quantitative DWI and PWI parameters in evaluating the efficacy of TACE for HCC patients. Among the 118 HCC patients, there were 17 cases (14.4%) with complete response, 50 cases (42.4%) with partial response, 28 cases (23.7%) with stable disease, and 23 cases (19.5%) with progressive disease. There were 67 patients in the effective group (complete response + partial response) and 51 patients in the ineffective group (stable disease + progressive disease). Before TACE, there were significant differences in maximum tumor diameter (MTD), apparent diffusion coefficient (ADC), slow ADC (Dslow), fast ADC (Dfast), transfer constant of vessel at the maximum level (Ktrans), and rate constant of backflux (Kep) between the effective and ineffective groups (all P<0.05). After TACE, the effective group exhibited lower MTD, Dfast, and Kep and higher ADC and Dslow than the ineffective group (all P<0.05). Tumor regression rate negatively correlated with MTD, Ktrans, Kep, and Dfast but positively correlated with ADC and Dslow. Receiver operating characteristic curve analysis suggested that the area under the curve of ADC, Dslow, Dfast, Ktrans, and Kep were 0.869, 0.833, 0.812, 0.802, and 0.809, respectively. In conclusion, these results suggest that quantitative DWI and PWI parameters might be useful in evaluating the efficacy of TACE in the treatment of

  17. Simultaneous Individually Controlled Upper and Lower Body Perfusion for Valve-Sparing Root and Total Aortic Arch Replacement: A Case Study

    PubMed Central

    Fernandes, Philip; Mayer, Rick; Adams, Corey; Chu, Michael W.A.

    2011-01-01

    Abstract: Optimal perfusion strategies for extensive aortic resection in patients with mega-aortic syndromes include: tailored myocardial preservation, antegrade cerebral perfusion, controlled hypothermia and selective organ perfusion. Typically, the aortic arch resection and elephant trunk procedure are performed under hypothermic circulatory arrest with myocardial and cerebral protection. However, mesenteric and systemic ischemia occur during circulatory arrest and commonly rely upon deep hypothermia alone for metabolic protection. We hypothesized that simultaneously controlled mesenteric and systemic perfusion can attenuate some of the metabolic debt accrued during circulatory arrest, which may help improve perioperative outcomes. The perfusion strategy consisted of delivering a 1 to 3 liter per minute flow at 25°C to the head/upper body via right axillary graft and simultaneous perfusion to the lower body/mesenteric organs of 1 to 3 liters per minute at 30°C via a right femoral arterial graft. We describe our technique of simultaneous mesenteric, systemic, cerebral and myocardial perfusion, and protection utilized for a young male patient with Marfan’s syndrome, while undergoing a valve sparing root replacement, total arch replacement and elephant trunk reconstruction. This perfusion technique allowed us to deliver differential flow rates and temperatures to the upper and lower body (cold head/warm lower body perfusion) to minimize ischemic debt and quickly reverse metabolic derangements. PMID:22416605

  18. The additive value of transient left ventricular dilation using two-day dipyridamole 99mTc-MIBI SPET for screening coronary artery disease in patients with otherwise normal myocardial perfusion: a comparison between diabetic and non-diabetic cases.

    PubMed

    Fallahi, Babak; Beiki, Davood; Fard-Esfahani, Armaghan; Akbarpour, Saeed; Abolhassani, Arash; Kakhki, Vahid Reza Dabbagh; Eftekhari, Mohammad

    2010-01-01

    The prognostic value of transient ischemic dilation (TID) has been previously confirmed; however, its clinical significance for screening coronary artery disease (CAD) with balanced ischemia, as a cause of false negative myocardial perfusion imaging (MPI), is unclear. The goal of this study was to determine the additive diagnostic value of TID ratio for screening CAD in separate subgroups of diabetic and non-diabetics with normal perfusion. Eighty six patients with intermediate probability of CAD who had TID more than one in the presence of otherwise normal MPI using two-day technetium-99m methoxy isobutyl isonitrile ((99m)Tc-MIBI) single photon emission tomography (SPET) and dipyridamole stress (summed stress score<3 and left ventricular cavity<90 mL) were included in a prospective cohort study comprising two subgroups of diabetic and non- diabetic patients. An inclusive work-up with multiple noninvasive tests was performed for all patients from whom 38 cases subsequently underwent coronary angiography and 48 cases were categorized in the group with a very low likelihood (<5%) of CAD on the basis of clinical and paraclinical data over a minimum of 18 months follow up. The TID ratio was calculated using automated software. Gensini score (GS) as an indicator of severity/extent of stenosis and coronary artery index (CAI) as the number of arteries with more than 50% narrowing were calculated based on angiographic findings. Our results showed that only in diabetic patients with three-vessel disease, TID ratio (1.47 ± 0.23) differs significantly from the other groups of CAD. In diabetic patients subgroup, TID ratio correlated strongly with GS (r=0.957, P<0.0001) and CAI (r=0.659, P=0.001), while such correlations were not seen in the non-diabetic patients. On the basis of receiver operating characteristic curve analysis for screening CAD in diabetic patients with normal myocardial perfusion, 100% sensitivity and 77.8% normalcy rate were achieved when TID more than 1

  19. Aortoiliac Artery Reconstruction Using Bilateral Reversed Superficial Femoral Veins for an Infected Abdominal Aortic Aneurysm

    PubMed Central

    Hirai, Hanako; Yasuhara, Kiyomitsu; Hatori, Kyohei; Miki, Takao; Obayashi, Tamiyuki

    2016-01-01

    Surgical treatment of an infected abdominal aortic aneurysm (IAAA) is difficult and the ideal graft material is a subject of debate. A 60-year-old man with untreated diabetes mellitus was referred to our hospital presenting with fever and left lower abdominal pain. The patient was diagnosed with an IAAA by blood culture and computed tomography. We treated the patient surgically for the IAAA using bilateral reversed superficial femoral veins which were shaped into a bifurcated graft. No signs of recurrent infection or aneurysmal dilation were observed for 3 years after the procedure. PMID:27087879

  20. Aortoiliac Artery Reconstruction Using Bilateral Reversed Superficial Femoral Veins for an Infected Abdominal Aortic Aneurysm.

    PubMed

    Ohki, Satoshi; Hirai, Hanako; Yasuhara, Kiyomitsu; Hatori, Kyohei; Miki, Takao; Obayashi, Tamiyuki

    2016-01-01

    Surgical treatment of an infected abdominal aortic aneurysm (IAAA) is difficult and the ideal graft material is a subject of debate. A 60-year-old man with untreated diabetes mellitus was referred to our hospital presenting with fever and left lower abdominal pain. The patient was diagnosed with an IAAA by blood culture and computed tomography. We treated the patient surgically for the IAAA using bilateral reversed superficial femoral veins which were shaped into a bifurcated graft. No signs of recurrent infection or aneurysmal dilation were observed for 3 years after the procedure.

  1. Comparison of Intrahepatic and Pancreatic Perfusion on Fusion Images Using a Combined SPECT/CT System and Assessment of Efficacy of Combined Continuous Arterial Infusion and Systemic Chemotherapy in Advanced Pancreatic Carcinoma

    SciTech Connect

    Ikeda, Osama Tamura, Yoshitaka; Nakasone, Yutaka; Shiraishi, Shinya; Kawanaka, Kouichi; Tomiguchi, Seiji; Yamashita, Yasuyuki; Takamori, Hiroshi; Kanemitsu, Keiichiro; Baba, Hideo

    2007-09-15

    Purpose. The purpose of this study was to compare intrahepatic and pancreatic perfusion on fusion images using a combined single-photon emission computed tomography (SPECT)/CT system and to evaluate the efficacy of combined continuous transcatheter arterial infusion (CTAI) and systemic chemotherapy in the treatment of advanced pancreatic carcinoma. Materials and Methods. CTAI was performed in 33 patients (22 men, 11 women; age range, 35-77 years; mean age, 60 years) with stage IV pancreatic cancer with liver metastasis. The reservoir was transcutaneously implanted with the help of angiography. The systemic administration of gemcitabine was combined with the infusion of 5-fluorouracil via the reservoir. In all patients we obtained fusion images using a combined SPECT/CT system. Pancreatic perfusion on fusion images was classified as perfusion presence or as perfusion absent in the pancreatic cancer. Using WHO criteria we recorded the tumor response after 3 months on multislice helical CT scans. Treatment effects were evaluated based on the pancreatic cancer, liver metastasis, and factors such as intrahepatic and pancreatic perfusion on fusion images. For statistical analysis we used the chi-square test; survival was evaluated by the Kaplan Meier method (log-rank test). Results. On fusion images, pancreatic and intrahepatic perfusion was recorded as hot spot and as homogeneous distribution, respectively, in 18 patients (55%) and as cold spot and heterogeneous distribution, respectively, in 15 (45%). Patients with hot spot in the pancreatic tumor and homogeneous distribution in the liver manifested better treatment results (p < 0.05 and p < 0.01, respectively). Patients with hot spot both in the pancreatic cancer and in the liver survived longer than those with cold spot in the pancreatic cancer and heterogeneous distribution in the liver (median {+-} SD, 16.0 {+-} 3.7 vs. 8.0 {+-} 1.4 months; p < 0.05). Conclusions. We conclude that in patients with advanced

  2. Effect of L-Carnitine Supplementation on Reverse Remodeling in Patients with Ischemic Heart Disease Undergoing Coronary Artery Bypass Grafting: A Randomized, Placebo-Controlled Trial.

    PubMed

    da Silva Guimarães, Sheila; de Souza Cruz, Wanise; da Silva, Licinio; Maciel, Gabrielle; Huguenin, Ana Beatriz; de Carvalho, Monicque; Costa, Bárbara; da Silva, Geisiane; da Costa, Carlos; D'Ippolito, João Alvaro; Colafranceschi, Alexandre; Scalco, Fernanda; Boaventura, Gilson

    2017-03-25

    During cardiac failure, cardiomyocytes have difficulty in using the substrates to produce energy. L-carnitine is a necessary nutrient for the transport of fatty acids that are required for generating energy. Coronary artery graft surgery reduces the plasma levels of L-carnitine and increases the oxidative stress. This study demonstrates the effect of L-carnitine supplementation on the reverse remodeling of patients undergoing coronary artery bypass graft. Patients with ischemic heart failure who underwent coronary graft surgery were randomized to group A - supplemented with L-carnitine or group B controls. Left ventricular ejection fraction, left ventricular systolic and diastolic diameters were assessed preoperatively, 60 and 180 days after surgery. Our study included 28 patients (26 [93.0%] males) with a mean age ± SD of 58.1 ± 10.5 years. The parameters for the evaluation of reverse remodeling did not improve after 60 and 180 days of coronary artery bypass grafting in comparison between groups (p > 0.05). Evaluation within the L-carnitine group showed a 37.1% increase in left ventricle ejection fraction (p = 0.002) and 14.3% (p = 0.006) and 3.3% (p > 0.05) reduction in systolic and diastolic diameters, respectively. L-carnitine supplementation at a dose of 50 mg/kg combined with artery bypass surgery did not demonstrate any additional benefit in reverse remodeling. However, evaluation within the L-carnitine group may indicate a clinical benefit of L-carnitine supplementation.

  3. Pulmonary Interstitial Glycogenosis: A Reversible Underlying Condition Associated With D-Transposition of the Great Arteries and Severe Persistent Pulmonary Hypertension.

    PubMed

    Sanchez-de-Toledo, Joan; González-Peris, Sebastià; Gran, Ferran; Gregoraci, Angela; Ferreres, Joan Carles; Ruiz, Cèsar W; Balcells, Joan; Abella, Raul F

    2015-07-01

    Transposition of the great arteries with intact ventricular septum and persistent pulmonary hypertension (TGA-IVS PPHN) is a rare association with a poor prognosis. We report the case of a term newborn with TGA-IVS PPHN successfully managed with perioperative extracorporeal membrane oxygenation (ECMO) and aggressive pulmonary vasodilation therapy that underwent successful arterial switch procedure. A lung biopsy obtained during the surgical procedure showed pulmonary interstitial glycogenosis, a reversible condition. Concerns over left ventricle deconditioning after ECMO could be minimized with appropriate management and monitoring of the ductus arteriosus and appropriate timing of surgery.

  4. Reversal of Anticoagulation With Dabigatran in an 82-Year-Old Patient With Traumatic Retroperitoneal Arterial Bleeding Using the New Antidote Idarucizumab: A Case Report.

    PubMed

    Hofer, Stefan; Philipsenburg, Christoph; Weigand, Markus A; Brenner, Thorsten

    2016-12-01

    Dabigatran etexilate is a direct oral anticoagulant used for the prevention of stroke in atrial fibrillation. Idarucizumab is a recently approved specific antidote that reverses the effect of dabigatran within minutes. We report the case of an 82-year-old patient with traumatic retroperitoneal arterial bleeding under anticoagulation with dabigatran etexilate. By administration of idarucizumab, we successfully normalized coagulation and saved the patient from an operation. In the course of the disease, a slight reincrease in dabigatran etexilate plasma levels was observed 2 days after the reversal, which could lead to a new onset of bleeding.

  5. Mechanisms of vasoconstrictor responses to KCl in rat isolated perfused tail arteries: interaction with the alpha 2-adrenoceptor agonist UK14304.

    PubMed

    Xiao, X H; Rand, M J

    1991-04-17

    The vasoconstriction in rat tail arteries during exposure to 56 mM KCl for 2-5 min consisted of an initial sharp peak followed by a secondary plateau. Both components were reduced by the alpha 1-adrenoceptor antagonists prazosin and WB4010. In arteries from reserpine-pretreated rats, the plateau was markedly reduced and only slightly further attenuated by prazosin, however the initial peak was not reduced but was now not affected by prazosin. Thus, the response to KCl in arteries from normal rats is partly due to release of noradrenaline, and this occurs to a greater extent in the plateau than in the peak component. Addition of UK14304 during the plateau reduced the vasoconstriction in arteries from normal rats; however, in arteries from reserpine-pretreated rats there was increased vasoconstriction. These effects of UK14304 were abolished by idazoxan and were not affected by prazosin, and can be attributed to prejunctional inhibition of noradrenaline release in arteries from normal rats and postjunctional enhancement of vasoconstriction in arteries from reserpine-pretreated rats.

  6. Evolution of pulmonary perfusion defects demonstrated with contrast-enhanced dynamic MR perfusion imaging.

    PubMed

    Howarth, N R; Beziat, C; Berthezène, Y

    1999-01-01

    Pulmonary perfusion defects can be demonstrated with contrast-enhanced dynamic MR perfusion imaging. We present the case of a patient with a pulmonary artery sarcoma who presented with a post-operative pulmonary embolus and was followed in the post-operative period with dynamic contrast-enhanced MR perfusion imaging. This technique allows rapid imaging of the first passage of contrast material through the lung after bolus injection in a peripheral vein. To our knowledge, this case report is the first to describe the use of this MR technique in showing the evolution of peripheral pulmonary perfusion defects associated with pulmonary emboli.

  7. Evaluation of efficacy of transcatheter arterial chemoembolization combined with computed tomography-guided radiofrequency ablation for hepatocellular carcinoma using magnetic resonance diffusion weighted imaging and computed tomography perfusion imaging

    PubMed Central

    Shao, Guo-Liang; Zheng, Jia-Ping; Guo, Li-Wen; Chen, Yu-Tang; Zeng, Hui; Yao, Zheng

    2017-01-01

    Abstract Background: The purpose of this study is to evaluate the efficacy of transcatheter arterial chemoembolization (TACE) combined with computed tomography-guided radiofrequency ablation (CT-RFA) in the treatment of hepatocellular carcinoma (HCC) using magnetic resonance diffusion weighted imaging (MR-DWI) and CT perfusion imaging (CT-PI). Methods: From January 2008 to January 2014, a total of 522 HCC patients receiving TACE combined with CT-RFA were included in this study. All patients underwent TACE followed by CT-RFA, and 1 day before treatment and 1 month after treatment they received MR-DWI and CT-PI. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the concentration of alpha-fetoprotein (AFP). Tumor response was evaluated using the revised RECIST criteria. One-year follow-up was conducted on all patients. Receiver-operating characteristic (ROC) curve was drawn to evaluate the efficacy of TACE combined with CT-RFA for HCC using MR-DWI and CT-PI. Results: Total effective rate (complete remission [CR] + partial remission [PR]) of TACE combined with CT-RFA for HCC was 82.95%. HCC patients of CR + PR had lower hepatic blood flow (HBF), hepatic blood volume (HBV), permeability surface (PS), hepatic arterial perfusion (HAP), and hepatic perfusion index (HPI) levels than those of SD + PD, but HCC patients of CR + PR had higher mean transit time (MTT) level than those of SD + PD. The patients of PR + CR had higher apparent diffusion coefficient (ADC) values than those of SD + PD. The patients of PR + CR showed lower AFP concentration than those of SD + PD. ROC curve analysis indicated that the area under the curve (AUC) of AFP, HBV, PS, HAP, HPI, and ADC was more than 0.7, but the AUC of HBF, MTT, and PVP were less than 0.7. After treatment, the AFP, HBF, HBV, PS, HAP, and HPI in the HCC patients with recurrence were higher than those in the HCC patients without, but MTT and ADC in the HCC patients with

  8. Anomalous Origin of the Left Common Carotid Artery from the Main Pulmonary Artery: A Rare Association in an Infant with CHARGE Syndrome

    PubMed Central

    Jones, Blaise; Hirsch, Russel

    2016-01-01

    Case Report. Isolated carotid artery originating from the pulmonary trunk is an exceedingly rare anomalous origin of head and neck vessels. We present this finding, along with a persistent embryonic trigeminal artery, in a male infant with multiple cardiac defects and other congenital anomalies associated with CHARGE syndrome. After extensive investigations, cardiac catheterization revealed the anomalous left common carotid artery arising from the cranial aspect of the main pulmonary artery. There was retrograde flow in this vessel, resulting from the lower pulmonary pressure, essentially stealing arterial supply from the left anterior cerebral circulation. The persistent left-sided trigeminal artery provided collateral flow from the posterior circulation to the left internal carotid artery territory, allowing for safe ligation of the anomalous origin of the left common carotid artery, thereby reversing the steal of arterial blood flow into the pulmonary circulation and resulting in a net improvement of cerebral perfusion. Conclusion. The possibility of this vascular anomaly should be considered in all infants with CHARGE syndrome. Surgical repair or ligation should be tailored to the specific patient circumstances, following a careful delineation of all sources of cerebral perfusion. PMID:27974985

  9. Effects of pressure on the shear modulus, mass and thickness of the perfused porcine kidney.

    PubMed

    Helfenstein, C; Gennisson, J-L; Tanter, M; Beillas, P

    2015-01-02

    Eleven fresh ex vivo porcine kidneys were perfused in the artery, vein and ureter with degassed Dulbecco׳s Modified Eagle Medium (DMEM). The effect of perfusion pressure was evaluated using ten different pressures combinations. The shear modulus of the tissues was estimated during perfusion using shear wave elastography. The organ weight change was measured by a digital scale and cameras were used to follow the changes of the dimensions after each pressure combination. The effect of perfusion on the weight and the thickness was non-reversible, whereas the effect on the shear modulus was reversible. Pressure was found to increase the average shear modulus in the cortex by as much as 73%. A pressure of 80 mmHg was needed to observe tissues shear modulus in the same range as in vivo tests (Gcortex=9.1 kPa, Gmedulla=8.5 kPa ex vivo versus Gcortex=9.1 kPa, Gmedulla=8.7 kPa in vivo in Gennisson et al., 2012).

  10. Arterial spin-labeling in routine clinical practice, part 3: hyperperfusion patterns.

    PubMed

    Deibler, A R; Pollock, J M; Kraft, R A; Tan, H; Burdette, J H; Maldjian, J A

    2008-09-01

    Arterial spin-labeled (ASL) perfusion imaging can be implemented successfully into a routine clinical neuroimaging protocol and can accurately demonstrate alterations in brain perfusion. We have observed patterns of focal, regional, and global hyperperfusion in a wide variety of disease processes. The causes of hyperperfusion at clinical ASL have not been previously characterized. Focal lesions such as brain tumors and vascular malformations with increased perfusion can be well depicted by ASL. More global causes of hyperperfusion, including postanoxia vasodilation and hypercapnia, may go undetected on conventional MR images, whereas the regional hyperperfusion, which may occur in reversible encephalopathies and luxury perfusion, has been consistently illustrated on ASL cerebral blood flow maps at our institution.

  11. Retrograde lower body arterial reservoir discharge underlies rapid reversal of ductus arteriosus shunting after early cord clamping at birth in preterm lambs.

    PubMed

    Smolich, Joseph J; Kenna, Kelly R; Mynard, Jonathan P

    2016-02-15

    Arterial reservoir ("windkessel") function, whereby a part of left ventricular (LV) output is stored in elastic arteries during systole and discharged in diastole, is a well-established physiological phenomenon. However, its role in rapid reversal (to left-to-right) and a systolic-to-diastolic shift of shunting across the ductus arteriosus after birth is unknown. To address this question, ductal and aortic isthmus flows were measured with high-fidelity transit-time probes in six anesthetized preterm fetal lambs before and after cord clamping and subsequent early mechanical ventilation and for 30 min postbirth. Descending aortic flow was calculated as the sum of isthmus and ductal flows. Left-to-right ductal flow profiles were related to those of the isthmus and descending aorta, with upper body arterial reservoir discharge indicated by forward diastolic isthmus flow, and retrograde lower body arterial reservoir discharge by negative diastolic descending aortic flow. Left-to-right ductal shunting appeared immediately after cord clamping (P < 0.001), due entirely to newly emergent retrograde lower body reservoir discharge, and rose with ventilation via increased lower body reservoir discharge (P < 0.005), supplemented by upper body reservoir discharge after 45 s (P < 0.025) and LV systolic flow after 3 min (P = 0.025). The contribution of lower body reservoir discharge to left-to-right ductal shunting fell to 55 ± 8% at ≥15 min (P < 0.001) but remained higher (P < 0.002) than LV systolic flow (33 ± 8%) or upper body reservoir discharge (12 ± 5%). These results suggest that retrograde lower body arterial reservoir discharge plays a key role in rapid reversal and a systolic-to-diastolic shift of ductal shunting after cord clamping and early ventilation at birth.

  12. Time course and factors predicting arterial stiffness reversal in patients with aldosterone-producing adenoma after adrenalectomy: prospective study of 102 patients

    PubMed Central

    Liao, Che-Wei; Lin, Lian-Yu; Hung, Chi-Sheng; Lin, Yen-Tin; Chang, Yi-Yao; Wang, Shuo-Meng; Wu, Vin-Cent; Wu, Kwan-Dun; Ho, Yi-Lwun; Satoh, Fumitoshi; Lin, Yen-Hung

    2016-01-01

    Primary aldosteronism not only results in hypertension but also stiffer arteries. The time course and factors predicting the reversal of arterial stiffness after treatment are unclear. We prospectively enrolled 102 patients with aldosterone-producing adenoma (APA) from March 2006 to January 2012. We measured the pulse wave velocity (PWV) between brachial-ankle (baPWV) and heart-ankle (haPWV) before, 6 and 12 months after their adrenalectomy. After treatment, the PWV decreased significantly during the first 6 months (both p < 0.001), but no further reduction in the following 6 months. The determinant factors for baseline baPWV were age, duration of hypertension, and baseline systolic blood pressure (SBP) in multivariate linear regression analysis, similar with baseline haPWV (determinants: age, duration of hypertension, baseline SBP and diastolic blood pressure (DBP)). In multivariate linear regression analysis, the decrease in DBP at 6 months (ΔDBP0-6mo) and baseline baPWV were significantly associated with the decrease in baPWV at 6 months (ΔbaPWV0-6mo). The associated factors of the change in haPWV at 6 months (ΔhaPWV0-6mo) were baseline haPWV, ΔDBP0-6mo and change in log-transformed plasma renin activity. Our result suggested that reversal of arterial stiffness in APA patients occurred early after adrenalectomy and determined by baseline vascular condition, hemodynamic factors, and humoral factors. PMID:26883298

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

    SciTech Connect

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

    1990-08-01

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

  14. Pathophysiology of carotid artery disease and related clinical syndromes.

    PubMed

    De Reuck, J L

    2004-02-01

    The severity of internal carotid artery lesion per se is a poor indicator of the cerebral haemodynamic status of the brain. Positron emission tomography (PET) of the brain allows to study the different pathophysiological changes related to carotid artery disease. Several stages of impairment of cerebral blood flow and metabolism can be shown such as the compensatory phases by the haemodynamic and the metabolic reserve, the transition to reversible (penumbra) and irreversible ischaemia and the phase of luxury perfusion. Distinct PET patterns correlate with certain clinical outcomes. PET studies found evidence for an embolic origin rather than for a low-flow status as most frequent cause of stroke in severe carotid artery disease. Except for deep borderzone infarcts in the centrum semi-ovale, most cortical borderzone infarcts are not due to chronic misery perfusion. Recent silent and recurrent infarcts can be demonstrated with Cobalt-55 PET, which is of importance for the therapeutical decision. The PET studies argue that carotid endarterectomy is successful probably by removing the source of emboli rather than by restoring the cerebral perfusion in severe carotid artery stenosis.

  15. Partial aortic occlusion and cerebral venous steal: venous effects of arterial manipulation in acute stroke.

    PubMed

    Pranevicius, Osvaldas; Pranevicius, Mindaugas; Liebeskind, David S

    2011-05-01

    Acute ischemic stroke therapy emphasizes early arterial clot lysis or removal. Partial aortic occlusion has recently emerged as an alternative hemodynamic approach to augment cerebral perfusion in acute ischemic stroke. The exact mechanism of cerebral flow augmentation with partial aortic occlusion remains unclear and may involve more than simple diversion of arterial blood flow from the lower body to cerebral collateral circulation. The cerebral venous steal hypothesis suggests that even a small increase in tissue pressure in the ischemic area will divert blood flow to surrounding regions with lesser tissue pressures. This may cause no-reflow (absence of flow after restoration of arterial patency) in the ischemic core and "luxury perfusion" in the surrounding regions. Such maldistribution may be reversed with increased venous pressure titrated to avoid changes in intracranial pressure. We propose that partial aortic occlusion enhances perfusion in the brain by offsetting cerebral venous steal. Partial aortic occlusion redistributes blood volume into the upper part of the body, manifested by an increase in central venous pressure. Increased venous pressure recruits the collapsed vascular network and, by eliminating cerebral venous steal, corrects perifocal perfusion maldistribution analogous to positive end-expiratory pressure recruitment of collapsed airways to decrease ventilation/perfusion mismatch in the lungs.

  16. Imaging of myocardial perfusion with magnetic resonance.

    PubMed

    Barkhausen, Jörg; Hunold, Peter; Jochims, Markus; Debatin, Jörg F

    2004-06-01

    Coronary artery disease (CAD) is currently the leading cause of death in developed nations. Reflecting the complexity of cardiac function and morphology, noninvasive diagnosis of CAD represents a major challenge for medical imaging. Although coronary artery stenoses can be depicted with magnetic resonance (MR) and computed tomography (CT) techniques, its functional or hemodynamic impact frequently remains elusive. Therefore, there is growing interest in other, target organ-specific parameters such as myocardial function at stress and first-pass myocardial perfusion imaging to assess myocardial blood flow. This review explores the pathophysiologic background, recent technical developments, and current clinical status of first-pass MR imaging (MRI) of myocardial perfusion.

  17. [Ocular perfusion pressure and its relevance for glaucoma].

    PubMed

    Schmidl, D; Werkmeister, R; Garhöfer, G; Schmetterer, L

    2015-02-01

    Ocular perfusion pressure is defined as the difference between arterial and venous pressure in ocular vessels. In practice, mean arterial pressure is used to substitute for arterial pressure in ocular vessels while intraocular pressure gives an estimate for ocular venous pressure. This results in a value that is easy to calculate and which is of importance since several studies have shown that it is correlated to the prevalence, incidence and progression of primary open angle glaucoma. Today, ocular perfusion pressure is used to estimate individual risks. Since no target value for ocular perfusion pressure can be defined, direct therapeutic intervention is difficult. Still, it has to be kept in mind that lowering intraocular pressure automatically leads to an increase in ocular perfusion pressure. The present article also points out problems and limitations in the concept of ocular perfusion pressure and suggests possible solutions for these problems in the future.

  18. Estimation of the percentage of transgenic Bt maize in maize flour mixtures using perfusion and monolithic reversed-phase high-performance liquid chromatography and chemometric tools.

    PubMed

    Rodríguez-Nogales, J M; Cifuentes, A; García, M C; Marina, M L

    2008-11-15

    The estimation of the percentage of transgenic Bt maize in maize flour mixtures has been achieved in this work by high-performance liquid chromatography using perfusion and monolithic columns and chemometric analysis. Principal component analysis allowed a preliminary study of the data structure. Then, linear discriminant analysis was used to develop decision rules to classify samples in the established categories (percentages of transgenic Bt maize). Finally, linear regression (LR) and multivariate regression models (namely, principal component analysis regression (PCR), partial least squares regression (PLS-1), and multiple linear regression (MLR)) were assayed for the prediction of the percentages of transgenic Bt maize present in a maize flour mixture. Using the relative areas of the protein peaks, MLR provided the best models and was able to predict the percentage of transgenic Bt maize in flour mixtures with an error of ±5.3%, ±2.3%, and ±3.8% in the predictions of Aristis Bt, DKC6575, and PR33P67, respectively.

  19. [Prognostic factors of perinatal short-term outcome in severe placental insufficiency using Doppler sonography to assess end-diastolic absent and reverse blood flow in umbilical arteries].

    PubMed

    Frauenschuh, I; Wirbelauer, J; Karl, S; Girschick, G; Rehn, M; Zollner, U; Frambach, T; Dietl, J; Müller, T

    2015-02-01

    Significant placental insufficiency, indicated by Doppler ultrasound findings of absent or reverse end-diastolic flow velocities (AREDV), is associated with increased morbidity and mortality. Analysis of blood flow in the ductus venosus should assist in early intrauterine recognition of threatened foetuses. 58 high-risk pregnancies with umbilical AREDV were repeatedly examined (n=364). Doppler findings were correlated with neonatal signs of deterioration (ratio of normoblasts to leukocytes, pH, base excess, Apgar score), as well as short-term morbidity [need for intubation, duration of assisted respiration, evidence of respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), necrotising enterocolitis (NEC), intraventricular haemorrhage (IVH grade III+IV)] against the analysis of the blood flow findings (normal or increased pulsitility, absence or reverse end-diastolic flow) in the umbilical arteries (AU), the middle cerebral arteries (ACM) and ductus venosus (DV) relating these to birth weight and the duration of the pregnancy. The median period of observation was 12.8 days, 48% of the foetuses showed an abnormal ductus venosus flow and 26% an absent venous or reverse end-diastolic flow. The median date of delivery was 30 weeks, with a mean birth weight of 816 g. 93% were live births with 12% dying postnatally. Although the criteria for postnatal morbidity (BPD, NEC, IVH III+IV) and mortality did not correlate with changes in arterial and venous Doppler parameters in our group, there was a significant relationship between the normoblast count, known to be a marker of chronic hypoxia. The Apgar 10 minte score, umbilical arterial pH and base excess were correlated with changes in the DV flow curves. Healthy survival started, irrespective of arterial or venous blood flow criteria, from 27+0 weeks of pregnancy. If born between 27.0 and 30+6 weeks, the infants were more likely to be healthy the less the blood flow had been compromised. A birth weight

  20. Implications of normal exercise electrocardiographic results in patients with angiographically documented coronary artery disease. Correlation with left ventricular function and myocardial perfusion.

    PubMed

    Hakki, A H; DePace, N L; Colby, J; Iskandrian, A S

    1983-09-01

    The purpose of this study was to examine the incidence and implications of false-negative exercise electrocardiographic results among 216 consecutive patients with angiographically documented coronary artery disease (50 percent diameter narrowing or greater of one or more vessels). Exercise electrocardiography gave negative (false-negative) results in 23 patients and positive (true-positive) results in 102 patients, and were nondiagnostic in the rest. Exercise thallium-201 imaging was performed in 88 patients. The extent of coronary artery disease was quantitated by a scoring system that takes into consideration the degree and site of narrowing in the major vessels and their branches. The exercise heart rate was higher in patients with false-negative than in patients with true-positive exercise electrocardiographic results (161 +/- 18 versus 133 +/- 24 beats per minute, mean +/- SD; p less than 0.0001). Q-wave infarction was present in two patients (9 percent) with false-negative and 20 patients (20 percent) with true-positive exercise electrocardiographic results (p = NS); left ventricular asynergy at rest was observed in 13 patients (57 percent) with false-negative and in 74 patients (74 percent) with true-positive results (p = NS). Patients with false-negative results had less extensive coronary disease than did patients with true-positive results (score 5.8 +/- 3.6 versus 9.2 +/- 5.0; p = 0.0025). Angina during exercise was less frequent in patients with false-negative results (p less than 0.01). Abnormal exercise thallium-201 images were seen in 15 of 20 patients (75 percent) with false-negative results and in 56 of 68 patients (82 percent) with true-positive results (p = NS). It is concluded that (1) false-negative exercise electrocardiographic results are infrequent (10 percent) among patients with coronary artery disease and are associated with less extensive coronary artery disease; (2) the frequency of Q-wave infarction and left ventricular asynergy is

  1. Reversal of "one kidney" to "two kidney" tipe of Goldblatt hypertension in a patient with bilateral artery stenosis.

    PubMed

    Scherer, B; Uhlich, E; Weber, P C; Heberer, G

    1977-09-15

    A 32-year old hypertensive woman with bilateral renal artery stenosis of more than 50% on both sides was studied. Renal vein renin levels were low (0.3 ng/ml/h on the right side and 0.42 on the left) before surgical correction of the left renal artery. Thereafter, blood pressure was only temporarily reduced. Four months later a repeat angiography demonstrated a widely patent left renal artery and the stenosis on the right side was unchanged. Renal vein renin was 5.12 on the left and 11.2 on the right. Subsequent operation on the right side lead to normalization of blood pressure. Thus, our patient seems to demonstrate in sequence the characteristics of the tow types of experimental renovacular hypertension known as "one kidney hypertension" and "two kidney hypertension". Our findings usggest that the pathomechanisms of these experimental models are operative in man too.

  2. Une complication rare de la grossesse gémellaire monochoriale: la séquence Twin-reversed arterial perfusion (TRAP)

    PubMed Central

    Jayi, Sofia; Laadioui, Meriem; Laabadi, Kamilia; Fdili, Fatima Zohra; Bouguern, Hakima; Chaara, Hikmat; Melhouf, Aabdelilah

    2015-01-01

    La séquence TRAP est une forme majeure et rare du syndrome transfuseur transfusé, caractérisée par l'absence de développement des structures cardiaques avec un spectre de malformations chez le fœtus transfusé qui n'est jamais viable et d'importantes complications touchant le jumeau transfuseur. Nous rapportons le cas d'une multipare admise avec expulsion en cours d'une présentation de siège, puis l'examen a trouvé une présentation irrégulière. Et à l’échographie une image hétérogène sans aire cardiaque ni organes fœtaux individualisables avec une seule masse placentaire sont visible, évoquant en premier un jumeau acardiaque. La voie basse a été acceptée, mais elle a présenté une hypercinésie évoquant un syndrome de prérupture. La césarienne a permis l'extraction d'une masse acardiaque. A travers ce cas, nous insistons sur l'intérêt du diagnostic prénatal de cette entité dans l'adaptation de la prise en charge, l'amélioration du pronostic du jumeau transfuseur ainsi que l’évitement du retard diagnostic et de ces conséquences. PMID:26175836

  3. Perfusion decellularization of whole organs.

    PubMed

    Guyette, Jacques P; Gilpin, Sarah E; Charest, Jonathan M; Tapias, Luis F; Ren, Xi; Ott, Harald C

    2014-01-01

    The native extracellular matrix (ECM) outlines the architecture of organs and tissues. It provides a unique niche of composition and form, which serves as a foundational scaffold that supports organ-specific cell types and enables normal organ function. Here we describe a standard process for pressure-controlled perfusion decellularization of whole organs for generating acellular 3D scaffolds with preserved ECM protein content, architecture and perfusable vascular conduits. By applying antegrade perfusion of detergents and subsequent washes to arterial vasculature at low physiological pressures, successful decellularization of complex organs (i.e., hearts, lungs and kidneys) can be performed. By using appropriate modifications, pressure-controlled perfusion decellularization can be achieved in small-animal experimental models (rat organs, 4-5 d) and scaled to clinically relevant models (porcine and human organs, 12-14 d). Combining the unique structural and biochemical properties of native acellular scaffolds with subsequent recellularization techniques offers a novel platform for organ engineering and regeneration, for experimentation ex vivo and potential clinical application in vivo.

  4. Lung Perfusion Scanning in Hepatic Cirrhosis

    PubMed Central

    Stanley, N. N.; Ackrill, P.; Wood, J.

    1972-01-01

    Abnormal lung perfusion scans using radioactive particles were found in five out of six cases of hepatic cirrhosis with arterial hypoxaemia. None had clinical evidence of cardiopulmonary disease or signs of pulmonary embolism on arteriography. The scan defects are probably caused by a disorder of the pulmonary microvasculature, which may show regional variation in severity. ImagesFIG. 1FIG. 2 PMID:4645896

  5. Perfusion lung scanning: differentiation of primary from thromboembolic pulmonary hypertension

    SciTech Connect

    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.

  6. Role of Perfusion at Rest in the Diagnosis of Myocardial Infarction Using Vasodilator Stress Cardiovascular Magnetic Resonance.

    PubMed

    Patel, Mita B; Mor-Avi, Victor; Kawaji, Keigo; Nathan, Sandeep; Kramer, Christopher M; Lang, Roberto M; Patel, Amit R

    2016-04-01

    In clinical practice, perfusion at rest in vasodilator stress single-photon emission computed tomography is commonly used to confirm myocardial infarction (MI) and ischemia and to rule out artifacts. It is unclear whether perfusion at rest carries similar information in cardiovascular magnetic resonance (CMR). We sought to determine whether chronic MI is associated with abnormal perfusion at rest on CMR. We compared areas of infarct and remote myocardium in 31 patients who underwent vasodilator stress CMR (1.5 T), had MI confirmed by late gadolinium enhancement (LGE scar), and coronary angiography within 6 months. Stress perfusion imaging during gadolinium first pass was followed by reversal with aminophylline (75 to 125 mg), rest perfusion, and LGE imaging. Resting and peak-stress time-intensity curves were used to obtain maximal upslopes (normalized by blood pool upslopes), which were compared between infarcted and remote myocardial regions of interest. At rest, there was no significant difference between the slopes in the regions of interest supplied by arteries with and without stenosis >70% (0.31 ± 0.16 vs 0.26 ± 0.15 1/s), irrespective of LGE scar. However, at peak stress, we found significant differences (0.20 ± 0.11 vs 0.30 ± 0.22 1/s; p <0.05), reflecting the expected stress-induced ischemia. Similarly, at rest, there was no difference between infarcted and remote myocardium (0.27 ± 0.14 vs 0.30 ± 0.17 1/s), irrespective of stenosis, but significant differences were seen during stress (0.21 ± 0.16 vs 0.28 ± 0.18 1/s; p <0.001), reflecting inducible ischemia. In conclusion, abnormalities in myocardial perfusion at rest associated with chronic MI are not reliably detectable on CMR images. Accordingly, unlike single-photon emission computed tomography, normal CMR perfusion at rest should not be used to rule out chronic MI.

  7. Human recombinant erythropoietin alters the flow-dependent vasodilatation of in vitro perfused rat mesenteric arteries with unbalanced endothelial endothelin-1 / nitric oxide ratio.

    PubMed

    Barhoumi, Tlili; Jallat, Isabelle; Berthelot, Alain; Laurant, Pascal

    2011-06-01

    Chronic use of human recombinant erythropoietin (r-HuEPO) is accompanied by serious vascular side effects related to the rise in blood viscosity and shear stress. We investigated the direct effects of r-HuEPO on endothelium and nitric oxide (NO)-dependent vasodilatation induced by shear stress of cannulated and pressurized rat mesenteric resistance arteries. Intravascular flow was increased in the presence or absence of the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME; 10(-4) mol/L). In the presence of r-HuEPO, the flow-dependent vasodilatation was attenuated, while L-NAME completely inhibited it. The association of r-HuEPO and L-NAME caused a vasoconstriction in response to the rise in intravascular flow. Bosentan (10(-5) mol/L), an inhibitor of endothelin-1 (ET-1) receptors, corrected the attenuated vasodilatation observed with r-HuEPO and inhibited the vasoconstriction induced by flow in the presence of r-HuEPO and L-NAME. r-HuEPO and L-NAME exacerbated ET-1 vasoconstriction. At shear stress values of 2 and 14 dyn/cm(2) (1 dyn = 10(-5) N), cultured EA.hy926 endothelial cells incubated with r-HuEPO, L-NAME, or both released greater ET-1 than untreated cells. In conclusion, r-HuEPO diminishes flow-induced vasodilatation. This inhibitory effect seems to implicate ET-1 release. NO withdrawal exacerbates the vascular effects of ET-1 in the presence of r-HuEPO. These findings support the importance of a balanced endothelial ET-1:NO ratio to avoid the vasopressor effects of r-HuEPO.

  8. Effect of cardiac dysrhythmia on cerebral perfusion.

    PubMed

    Sand, B J; Rose, H B; Barker, W F

    1976-07-01

    Extracranial carotid arterial obstructive disease has been the entity most commonly associated with transient cerebrovascular insufficiency. A nonobstructive, frequently overlooked cause of cerebral ischemia is cardiac dysrhythmia. We have explored this by observations of experimental animals and of man. Blood flow and pressure in the carotid arteries of dogs were shown to be decreased by mechnically induced premature ventricular contractions. The significance of the cardiogenic contribution to altered cerebrovascular perfusion was studied by ocular and brachial plethysmography in 210 patients suspected by history of having carotid arterial insufficiency. Of the 210 patients, 62 demonstrated abnormal ocular plethysmographic recordings, and of those, nine had dysrhythmias associated with significant deficits of ocular perfusion. Five patients whose recordings were technically suitable for publication are presented to demonstrate the bizarre ocular plethysmographic recordings seen during the dysrhythmic cycle.

  9. Arterial stiffness: pathophysiology and clinical impact.

    PubMed

    London, Gérard M; Marchais, Sylvain J; Guerin, Alain P; Pannier, Bruno

    2004-01-01

    The ill effects of hypertension are usually attributed to a reduction in the caliber or the number of arterioles, resulting in an increase in total peripheral resistance (TPR). This definition does not take into account the fact that BP is a cyclic phenomenon with systolic and diastolic BP being the limits of these oscillations. The appropriate term to define the arterial factor(s) opposing LV ejection is aortic input impedance which depends on TPR, arterial distensibility (D), and wave reflections (WR). D defines the capacitive properties of arterial stiffness, whose role is to dampen pressure and flow oscillations and to transform pulsatile flow and pressure in arteries into a steady flow and pressure in peripheral tissues. Stiffness is the reciprocal value of D. These parameters are BP dependent, and arteries become stiffer at high pressure. In to D which provides information about the of artery as a hollow structure, the elastic incremental modulus (Einc) characterizes the properties of the arterial wall biomaterials, independently of vessel geometry. As an alternative, arterial D can be evaluated by measuring the pulse wave velocity (PWV) which increases with the stiffening of arteries. Arterial stiffening increases left ventricular (LV) afterload and alters the coronary perfusion. With increased PWV, the WR impacts on the aorta during systole, increasing systolic pressures and myocardial oxygen consumption, and decreasing diastolic BP and coronary flow. The arterial stiffness is altered primarily in association with increased collagen content and alterations of extracellular matrix (arteriosclerosis) as classically observed during aging or in arterial hypertension. The arterial stiffening estimated by changes in aortic PWV and intensity of WR are independent predictors of survival in end stage renal disease (ESRD) and general population. Improvement of arterial stiffening could be obtained by antihypertensive treatmen as observed with the calcium

  10. Vasodilator myocardial perfusion imaging: demonstration of local electrophysiological changes of ischaemia

    PubMed Central

    John, Roy M; Taggart, Peter I; Sutton, Peter M; Costa, Durval C; Ell, Peter J; Swanton, Howard

    1992-01-01

    Objective—To examine the incidence and severity of myocardial ischaemia provoked in the course of perfusion scintigraphy by coronary vasodilators using endocardial recordings of steady state monophasic action potentials as an independent marker of early localised myocardial ischaemia. Patients—31 men undergoing routine cardiac catheterisation for investigation of chest pain were studied. Setting—A tertiary cardiac referral centre. Design—Single site monophasic action potentials were recorded from the left or right ventricle or both (50 recording sites) during intravenous infusion of dipyridamole (0·015 mg/kg/min) for four minutes. Heart rate was held constant with atrial pacing at 20% above the patient's resting rate. Technetium-99m hexakis-2-methoxy-2-methylpropyl-isonitrile (MIBI) was administered four minutes after dipyridamole, and single photon emission tomographic imaging was performed an hour later. Rest images were obtained the next day (two day, two dose protocol). Recordings were divided into three groups based on the scintigraphic perfusion characteristics and coronary anatomical data for the action potential recording site: group 1—recordings from areas with a normal perfusion pattern (n = 30), group 2—recordings from areas with a perfusion defect and subtended by significantly narrowed coronary arteries without obvious angiographic collateral supply (n = 10), and group 3—recordings from areas with a perfusion defect and subtended by occluded arteries with angiographically evident collaterals from adjacent vessels (n = 10). Results—There were changes in the duration of the monophasic action potential indicative of ischaemia—that is, shortening of duration of steady state action potential—in 18 of the 20 recordings from areas of abnormal perfusion. Peak changes were apparent eight minutes from the start of the dipyridamole infusion. Mean (SEM) values for duration of the action potential between control and peak effect at eight

  11. Resting thallium-201 myocardial perfusion patterns in patients with severe left ventricular dysfunction: differences between patients with primary cardiomyopathy, chronic coronary artery disease, or acute myocardial infarction

    SciTech Connect

    Iskandrian, A.S.; Hakki, A.H.; Kane, S.

    1986-04-01

    This study examined the value of resting thallium-201 imaging in differentiating patients with primary cardiomyopathy from those with ischemic cardiomyopathy. There were 15 patients with primary cardiomyopathy (group I); 20 with chronic CAD (group II); and 25 with acute Q wave myocardial infarction (group III). All patients had LVEF less than or equal to 35%. The thallium score was less than 50 (maximum 60) in one patient (7%) in group I, in 17 patients (85%) in group II, and in 25 patients (100%) in group III (p less than 0.0001, I vs II and III). The number of normal segments was 11.4 +/- 4.9 in group I, 6.9 +/- 2.9 in group II, and 7.0 +/- 2.2 in group III (p less than 0.0001, I vs II, III). Reversible defects were present in three patients in group II, three in group III, and none in group I. Abnormal right ventricular thallium uptake was observed in 27% of patients in group I, 25% in group II, and 40% in group III (p = NS). Abnormal lung thallium uptake was observed in 33% in group I, 20% in group II, and 20% in group III (p = NS). Thus, rest thallium imaging is useful in separating patients with primary cardiomyopathy from those with ischemic cardiomyopathy.

  12. Noninvasive diagnostic test choices for the evaluation of coronary artery disease in women: a multivariate comparison of cardiac fluoroscopy, exercise electrocardiography and exercise thallium myocardial perfusion scintigraphy

    SciTech Connect

    Hung, J.; Chaitman, B.R.; Lam, J.; Lesperance, J.; Dupras, G.; Fines, P.; Bourassa, M.G.

    1984-07-01

    Several diagnostic noninvasive tests to detect coronary and multivessel coronary disease are available for women. However, all are imperfect and it is not yet clear whether one particular test provides substantially more information than others. The aim of this study was to evaluate clinical findings, exercise electrocardiography, exercise thallium myocardial scintigraphy and cardiac fluoroscopy in 92 symptomatic women without previous infarction and determine which tests were most useful in determining the presence of coronary disease and its severity. Univariate analysis revealed two clinical, eight exercise electrocardiographic, seven myocardial scintigraphic and seven fluoroscopic variables predictive of coronary or multivessel disease with 70% or greater stenosis. The multivariate discriminant function analysis selected a reversible thallium defect, coronary calcification and character of chest pain syndrome as the variables most predictive of presence or absence of coronary disease. The ranked order of variables most predictive of multivessel disease were cardiac fluoroscopy score, thallium score and extent of ST segment depression in 14 electrocardiographic leads. Each provided statistically significant information to the model. The estimate of predictive accuracy was 89% for coronary disease and 97% for multivessel coronary disease. The results suggest that cardiac fluoroscopy or thallium scintigraphy provide significantly more diagnostic information than exercise electrocardiography in women over a wide range of clinical patient subsets.

  13. Reversible Akinetic Mutism after Aneurysmal Subarachnoid Haemorrhage in the Territory of the Anterior Cerebral Artery without Permanent Ischaemic Damage to Anterior Cingulate Gyri

    PubMed Central

    Sibille, François-Xavier; Duprez, Thierry; van Pesch, Vincent; Giglioli, Simone

    2016-01-01

    We report on two cases of transient akinetic mutism after massive subarachnoid haemorrhage due to the rupture of an intracranial aneurysm of the anterior cerebral artery (ACA). In the two cases, vasospasm could not be demonstrated by imaging studies throughout the clinical course. Both patients shared common radiological features: a hydrocephalus due to haemorrhagic contamination of the ventricular system and a mass effect of a subpial hematoma on the borders of the corpus callosum. Patients were also investigated using auditory event-related evoked potentials at acute stage. In contrast to previous observations of akinetic mutism, P300 wave could not be recorded. Both patients had good recovery and we hypothesized that this unexpectedly favourable outcome was due to the absence of permanent structural damage to the ACA territory, with only transient dysfunction due to a reversible mass effect on cingulate gyri. PMID:27418987

  14. Procedure for Decellularization of Rat Livers in an Oscillating-pressure Perfusion Device.

    PubMed

    Hillebrandt, Karl; Polenz, Dietrich; Butter, Antje; Tang, Peter; Reutzel-Selke, Anja; Andreou, Andreas; Napierala, Hendrik; Raschzok, Nathanael; Pratschke, Johann; Sauer, Igor M; Struecker, Benjamin

    2015-08-10

    Decellularization and recellularization of parenchymal organs may enable the generation of functional organs in vitro, and several protocols for rodent liver decellularization have already been published. We aimed to improve the decellularization process by construction of a proprietary perfusion device enabling selective perfusion via the portal vein and/or the hepatic artery. Furthermore, we sought to perform perfusion under oscillating surrounding pressure conditions to improve the homogeneity of decellularization. The homogeneity of perfusion decellularization has been an underestimated factor to date. During decellularization, areas within the organ that are poorly perfused may still contain cells, whereas the extracellular matrix (ECM) in well-perfused areas may already be affected by alkaline detergents. Oscillating pressure changes can mimic the intraabdominal pressure changes that occur during respiration to optimize microperfusion inside the liver. In the study presented here, decellularized rat liver matrices were analyzed by histological staining, DNA content analysis and corrosion casting. Perfusion via the hepatic artery showed more homogenous results than portal venous perfusion did. The application of oscillating pressure conditions improved the effectiveness of perfusion decellularization. Livers perfused via the hepatic artery and under oscillating pressure conditions showed the best results. The presented techniques for liver harvesting, cannulation and perfusion using our proprietary device enable sophisticated perfusion set-ups to improve decellularization and recellularization experiments in rat livers.

  15. Liraglutide prevents and reverses monocrotaline-induced pulmonary arterial hypertension by suppressing ET-1 and enhancing eNOS/sGC/PKG pathways

    PubMed Central

    Lee, Mei-Yueh; Tsai, Kun-Bow; Hsu, Jong-Hau; Shin, Shyi-Jang; Wu, Jiunn-Ren; Yeh, Jwu-Lai

    2016-01-01

    Liraglutide, a glucagon-like peptide-1 receptor (GLP-1R) agonist, is widely used to treat diabetes. However, its effect on pulmonary arterial hypertension (PAH) is unknown. In this study, we investigated its effects on rats with monocrotaline (MCT)-induced PAH and mechanisms on rat pulmonary artery smooth muscle cells (PASMCs). Liraglutide was investigated for both prevention and treatment of MCT-induced PAH. The hemodynamic and body weight changes, right heart hypertrophy, lung morphology, immune-reactivity of endothelial nitric oxide synthase (eNOS), endothelin-1 and cyclic guanosine monophosphate (cGMP) levels, protein expressions of eNOS, soluble guanylyl cyclase (sGCα), protein kinase G (PKG) and Rho kinase (ROCK) II pathway were measured in both in vivo and in vitro. Cell migration and cell cycle were also determined. Liraglutide both prevented and reversed MCT-induced PAH, right ventricle hypertrophy and pulmonary vascular wall remodeling. Protein expression of ROCK II was increased while eNOS, sGC and PKG were decreased. Pretreatment with liraglutide inhibited platelet-derived growth factor (PDGF)-BB stimulated PASMCs migration, which were associated with cell-cycle arrest at G0/G1 phase. Liraglutide may have both preventive and therapeutic effects on MCT-induced PAH, through the eNOS/sGC/PKG and Rho kinase pathways. Thus, liraglutide may have a therapeutic role in pulmonary vascular remodelling. PMID:27581840

  16. Sesamin attenuates behavioral, biochemical and histological alterations induced by reversible middle cerebral artery occlusion in the rats.

    PubMed

    Khan, Mohd Moshahid; Ishrat, Tauheed; Ahmad, Ajmal; Hoda, Md Nasrul; Khan, M Badruzzaman; Khuwaja, Gulrana; Srivastava, Pallavi; Raza, Syed Shadab; Islam, Fakhrul; Ahmad, Saif

    2010-01-05

    Restoration of blood flow to an ischemic brain region is associated with generation of reactive oxygen species (ROS) with consequent reperfusion injury. ROS cause lipid peroxidation, protein oxidation, and DNA damage, all of which are deleterious to cells. So diminishing the production of free radicals and scavenging them may be a successful therapeutic strategy for the protection of brain tissue in cerebral stroke. The present study investigated the neuroprotective effect of sesamin (Sn) to reduce brain injury after middle cerebral artery occlusion (MCAO). The middle cerebral artery (MCA) of adult male Wistar rat was occluded for 2h and reperfused for 22h. Sesamin is the most abundant lignan in sesame seed oil is a potent antioxidant. Sesamin (30 mg/kg) was given orally twice, 30 min before the onset of ischemia and 12h after reperfusion. The initial investigations revealed that sesamin reduced the neurological deficits in terms of behavior and reduced the level of thiobarbituric acid reactive species (TBARS), and protein carbonyl (PC) in the different areas of the brain when compared with the MCAO group. A significantly depleted level of glutathione and its dependent enzymes (glutathione peroxidase [GPx] and glutathione reductase [GR]) in MCAO group were protected significantly in MCAO group treated with sesamin. The present study suggests that sesamin may be able to attenuate the ischemic cell death and plays a crucial role as a neuroprotectant in regulating levels of reactive oxygen species in the rat brain. Thus, sesamin may be a potential compound in stroke therapy.

  17. Vapor resistant arteries

    NASA Technical Reports Server (NTRS)

    Shaubach, Robert M. (Inventor); Dussinger, Peter M. (Inventor); Buchko, Matthew T. (Inventor)

    1989-01-01

    A vapor block resistant liquid artery structure for heat pipes. A solid tube artery with openings is encased in the sintered material of a heat pipe wick. The openings are limited to that side of the artery which is most remote from the heat source. The liquid in the artery can thus exit the artery through the openings and wet the sintered sheath, but vapor generated at the heat source is unlikely to move around the solid wall of the artery and reverse its direction in order to penetrate the artery through the openings. An alternate embodiment uses finer pore size wick material to resist vapor entry.

  18. CAD of myocardial perfusion

    NASA Astrophysics Data System (ADS)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

    Our purpose is in the automated evaluation of the physiological relevance of lesions in coronary angiograms. We aim to extract as much as possible quantitative information about the physiological condition of the heart from standard angiographic image sequences. Coronary angiography is still the gold standard for evaluating and diagnosing coronary abnormalities as it is able to locate precisely the coronary artery lesions. The dimensions of the stenosis can be assessed nowadays successfully with image processing based Quantitative Coronary Angiography (QCA) techniques. Our purpose is to assess the clinical relevance of the pertinent stenosis. We therefore analyze the myocardial perfusion as revealed in standard angiographic image sequences. In a Region-of-Interest (ROI) on the angiogram (without an overlaying major blood vessel) the contrast is measured as a function of time (the so-called time-density curve). The required hyperemic state of exercise is induced artificially by the injection of a vasodilator drug e.g. papaverine. In order to minimize motion artifacts we select based on the recorded ECG signal end-diastolic images in both a basal and a hyperemic run in the same projection to position the ROI. We present the development of the algorithms together with results of a small study of 20 patients which have been catheterized following the standard protocol.

  19. The Groningen hypothermic liver perfusion pump: functional evaluation of a new machine perfusion system.

    PubMed

    van der Plaats, A; Maathuis, M H J; 'T Hart, N A; 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

    2006-12-01

    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, sufficient oxygenation, a maintained 0-4 degrees C temperature and sterile conditions. Porcine livers were perfused with pump pressures that were set at 4 mmHg (continuous, portal vein) and 30/20 mmHg, at 60 BPM (pulsatile, hepatic artery). Control livers were preserved using the clinical golden standard: static cold storage. In the HMP group, pressure, flow and temperature were continuously monitored for 24 h. At time-points t = 0, 2, 4, 8, 12, and 24 h samples of University of Wisconsin machine preservation solution were taken for measurement of partial oxygen pressure (pO(2)) and lacto-dehydrogenase. Biopsies in every lobe were taken for histology and electron microscopy; samples of ice, preservation solution, liver surface, and bile were taken and cultured to determine sterility. Results showed that temperature was maintained at 0-4 degrees C; perfusion pressure was maintained at 4 mmHg and 30/20 mmHg for portal vein and hepatic artery, respectively. Flow was approximately 350 and 80 ml/min, respectively, but decreased in the portal vein, probably due to edema formation. Arterial pO(2) was kept at 100 kPa. Histology showed complete perfusion of the liver with no major damage to hepatocytes, bile ducts, and non-parenchymal cells compared to control livers. The machine perfusion system complied to the design criteria and will have to demonstrate the superiority of machine perfusion over cold storage in transplant experiments.

  20. LOW DOSE NITRITE ENHANCES PERFUSION AFTER FLUID RESUSCITATION FROM HEMORRHAGIC SHOCK

    PubMed Central

    Cabrales, Pedro

    2010-01-01

    This study determines the systemic and microvascular hemodynamic consequences of administering a low dose sodium nitrite after fluid resuscitation from hemorrhagic shock. Hemodynamic responses to hemorrhagic shock and resuscitation were studied in the hamster window chamber model. Moderated hemorrhage was induced by arterial controlled bleeding of 50% of the blood volume (BV) and the hypovolemic state was maintained for one hour. Volume restitution was performed by infusion of 25% of BV using Hextend® (6% Hetastarch 670 kDa in lactated electrolyte solution) 10 min after fluid resuscitation 100μl of specific concentrations of sodium nitrite were infused. The experimental groups were named based on the nitrite concentration used, namely: 0 μM, 10 μM and 50 μM. Systemic parameters, microvascular hemodynamics and capillary perfusion (functional capillary density, FCD) were followed during entire protocol. Exogenous 10 μM nitrite maintained systemic and microhemodynamic conditions post fluid resuscitation from hemorrhagic shock, compared to 50 μM or no nitrite. A moderated increase in plasma nitrite during the early phase of resuscitation reversed arteriolar vasoconstriction and increased capillary perfusion and venous return, improving central cardiac function. Nitrite effects on resistance vessels, directly influenced intravascular pressure redistribution, sustained blood flow, and prevented tissue ischemia. In conclusion, increasing nitrite plasma bioavailability after fluid resuscitation from hemorrhagic shock can be a potential therapy to enhance microvascular perfusion and to improve overall outcome. PMID:19804938

  1. Vasoconstrictors alter oxygen, lactate, and glycerol metabolism in the perfused hindlimb of a rat kangaroo.

    PubMed

    Ye, J M; Edwards, S J; Rose, R W; Rattigan, S; Clark, M G; Colquhoun, E Q

    1995-05-01

    The Tasmanian bettong (Bettongia gaimardi) is a small marsupial rat kangaroo without detectable brown adipose tissue (BAT). The hindlimb was perfused with constant flow at 25 degrees C after cannulation under anesthesia of the femoral artery and vein to one hindlimb. Norepinephrine (NE, 25 nM-2.5 microM) and vasopressin (VP, 10 nM-0.1 microM) each increased perfusion pressure, oxygen consumption (VO2), and lactate and glycerol efflux of the perfused hindlimb. NE-mediated increases in VO2 and the efflux of lactate and glycerol were unaffected by propranolol (10 microM) but were completely blocked by the further addition of phentolamine (10 microM). In contrast, serotonin (5-HT; 0.1-2.5 microM) inhibited VO2 and inhibited lactate efflux. The changes induced by NE, VP, and 5-HT were all rapidly reversed by nitroprusside. These results suggest that resting thermogenesis in bettong hindlimb can be differentially controlled by the vasculature, which may also contribute to the induced VO2. This vascular control of skeletal muscle VO2 appears widespread in homeotherm evolution.

  2. Value of rest-stress myocardial positron tomography using nitrogen-13 ammonia for the preoperative prediction of reversible asynergy

    SciTech Connect

    Tamaki, N.; Yonekura, Y.; Yamashita, K.; Senda, M.; Saji, H.; Konishi, Y.; Hirata, K.; Ban, T.; Konishi, J. )

    1989-08-01

    To determine the predictive value of stress (13N)ammonia positron emission tomography (PET) for reversible ischemia, 31 patients with coronary artery disease underwent rest-stress (13N)ammonia PET before and after coronary artery bypass surgery. The circumferential profile analysis was applied to determine the presence of transient defect (TD) and persistent defect (PD) preoperatively, and the fate of perfusion abnormality and asynergy after the surgery was assessed. Preoperative PET demonstrated 100 segments with perfusion abnormalities, including 69 TD and 31 PD. Fifty-six of the 69 TD (81%) improved in regional perfusion, while only four of 31 PD (13%) improved in perfusion postoperatively (p less than 0.001). Of 75 segments showing regional asynergy on contrast or radionuclide ventriculography preoperatively, 34 of 48 segments with TD (71%) improved in asynergy, while only five of 27 segments with PD (19%) improved in asynergy postoperatively (p less than 0.001). Stress-delayed 201TI tomography was performed in 22 of them. The predictive values for improvement in perfusion (77%) and asynergy (65%) were similar as those by (13N)ammonia PET (81% and 71%, respectively). However, the predictive values for no improvement in perfusion and asynergy by 201TI tended to be low (66% and 58%, respectively), as compared to those in 13N ammonia PET (87%; p less than 0.05 and 81%; p = 0.09, respectively). We conclude that an accurate prediction of reversible ischemia and asynergy can be achieved with rest-stress (13N)ammonia PET. Particularly, it can identify irreversible areas more accurately than the commonly performed stress-delayed 201TI imaging.

  3. Hepatic perfusion abnormalities during CT angiography: Detection and interpretation

    SciTech Connect

    Freeny, P.C.; Marks, W.M.

    1986-06-01

    Twenty-seven perfusion abnormalities were detected in 17 of 50 patients who underwent computed tomographic angiography (CTA) of the liver. All but one of the perfusion abnormalities occurred in patients with primary or metastatic liver tumors. Perfusion abnormalities were lobar in nine cases, segmental in 11, and subsegmental in seven; 14 were hypoperfusion and 13 were hyperperfusion abnormalities. The causes for the abnormalities included nonperfusion of a replaced hepatic artery (n = 11), cirrhosis and nodular regeneration (n = 3), altered hepatic hemodynamics (e.g., siphoning, laminar flow) caused by tumor (n = 7), contrast media washout from a nonperfused vessel (n = 1), compression of adjacent hepatic parenchyma (n = 1), and unknown (n = 4). Differentiation of perfusion abnormalities from tumor usually can be made by comparing the morphology of the known tumor with the suspected perfusion abnormality, changes of each on delayed CTA scans, and review of initial angiograms and other imaging studies.

  4. Impedance plethysmography: a new method for continuous muscle perfusion monitoring.

    PubMed

    Concannon, M J; Stewart, D H; Welsh, C F; Puckett, C L

    1991-08-01

    Vigilant postoperative monitoring of the buried muscle flap is critical after free transfer because early diagnosis of vascular insufficiency is essential to allow prompt correction. We have identified a monitoring method utilizing needle electrodes and impedance plethysmography that gives a beat-to-beat representation of muscular perfusion. In 25 New Zealand White rabbits the gastrocnemius muscle was isolated on its vascular pedicle, and two intramuscular needle electrodes were placed. The instantaneous impedance changes of the muscle (corresponding to the pulsatile volume changes of perfusion) were measured and recorded. Using this representation of perfusion, an independent judge was able to correctly diagnose muscular ischemia 100 percent of the time (n = 25). Further, the judge was able to correctly distinguish the ischemia as arterial (n = 10) or venous (n = 10) in origin 100 percent of the time. Additionally, we monitored muscle perfusion transcutaneously in five free muscle flaps and demonstrated a reliable impedance signal that correlated with perfusion.

  5. Diagnostic Performance of Dual-Energy CT Stress Myocardial Perfusion Imaging: Direct Comparison With Cardiovascular MRI

    PubMed Central

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

    2014-01-01

    OBJECTIVE 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. SUBJECTS AND METHODS 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 hemodynamically significant stenosis was assessed before and after stress perfusion DECT on a pervessel basis with ICA and cardiovascular stress perfusion MRI as the reference standard. RESULTS 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. CONCLUSION Stress perfusion DECT plays a complementary role in enhancing the accuracy of coronary CTA for identifying hemodynamically

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

    PubMed Central

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

    2016-01-01

    Abstract: Open aortic arch replacement is a complex and challenging procedure, especially in post dissection aneurysms and in redo procedures after previous surgery of the ascending aorta or aortic root. We report our experience with the simultaneous selective perfusion of heart, brain, and remaining body to ensure optimal perfusion and to minimize perfusion-related risks during these procedures. We used a specially configured heart–lung machine with a centrifugal pump as arterial pump and an additional roller pump for the selective cerebral perfusion. Initial arterial cannulation is achieved via femoral artery or right axillary artery. After lower body circulatory arrest and selective antegrade cerebral perfusion for the distal arch anastomosis, we started selective lower body perfusion simultaneously to the selective antegrade cerebral perfusion and heart perfusion. Eighteen patients were successfully treated with this perfusion strategy from October 2012 to November 2015. No complications related to the heart–lung machine and the cannulation occurred during the procedures. Mean cardiopulmonary bypass time was 239 ± 33 minutes, the simultaneous selective perfusion of brain, heart, and remaining body lasted 55 ± 23 minutes. One patient suffered temporary neurological deficit that resolved completely during intensive care unit stay. No patient experienced a permanent neurological deficit or end-organ dysfunction. These high-risk procedures require a concept with a special setup of the heart–lung machine. Our perfusion strategy for aortic arch replacement ensures a selective perfusion of heart, brain, and lower body during this complex procedure and we observed excellent outcomes in this small series. This perfusion strategy is also applicable for redo procedures. PMID:27729705

  7. Management of Liver Cancer Argon-helium Knife Therapy with Functional Computer Tomography Perfusion Imaging.

    PubMed

    Wang, Hongbo; Shu, Shengjie; Li, Jinping; Jiang, Huijie

    2016-02-01

    The objective of this study was to observe the change in blood perfusion of liver cancer following argon-helium knife treatment with functional computer tomography perfusion imaging. Twenty-seven patients with primary liver cancer treated with argon-helium knife and were included in this study. Plain computer tomography (CT) and computer tomography perfusion (CTP) imaging were conducted in all patients before and after treatment. Perfusion parameters including blood flows, blood volume, hepatic artery perfusion fraction, hepatic artery perfusion, and hepatic portal venous perfusion were used for evaluating therapeutic effect. All parameters in liver cancer were significantly decreased after argon-helium knife treatment (p < 0.05 to all). Significant decrease in hepatic artery perfusion was also observed in pericancerous liver tissue, but other parameters kept constant. CT perfusion imaging is able to detect decrease in blood perfusion of liver cancer post-argon-helium knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy.

  8. Thallium-201 scintigraphy perfusion defect with dipyridamole in a patient with a myocardial bridge

    SciTech Connect

    Bennett, J.M.; Blomerus, P.

    1988-04-01

    A patient with myocardial bridging and a thallium-201 scintigraphy perfusion defect after the administration of intravenous dipyridamole is presented. The same patient had a normal perfusion study on exercise stress testing. The effects of coronary vasodilators and dipyridamole on coronary artery flow patterns in patients with myocardial bridging are discussed. We suggest that coronary vasodilators may induce perfusion defects in patients with myocardial bridging and should be avoided in such patients.

  9. Assessment of foot perfusion in patients with a diabetic foot ulcer.

    PubMed

    Forsythe, Rachael O; Hinchliffe, Robert J

    2016-01-01

    Assessment of foot perfusion is a vital step in the management of patients with diabetic foot ulceration, in order to understand the risk of amputation and likelihood of wound healing. Underlying peripheral artery disease is a common finding in patients with foot ulceration and is associated with poor outcomes. Assessment of foot perfusion should therefore focus on identifying the presence of peripheral artery disease and to subsequently estimate the effect this may have on wound healing. Assessment of perfusion can be difficult because of the often complex, diffuse and distal nature of peripheral artery disease in patients with diabetes, as well as poor collateralisation and heavy vascular calcification. Conventional methods of assessing tissue perfusion in the peripheral circulation may be unreliable in patients with diabetes, and it may therefore be difficult to determine the extent to which poor perfusion contributes to foot ulceration. Anatomical data obtained on cross-sectional imaging is important but must be combined with measurements of tissue perfusion (such as transcutaneous oxygen tension) in order to understand the global and regional perfusion deficit present in a patient with diabetic foot ulceration. Ankle-brachial pressure index is routinely used to screen for peripheral artery disease, but its use in patients with diabetes is limited in the presence of neuropathy and medial arterial calcification. Toe pressure index may be more useful because of the relative sparing of pedal arteries from medial calcification but may not always be possible in patients with ulceration. Fluorescence angiography is a non-invasive technique that can provide rapid quantitative information about regional tissue perfusion; capillaroscopy, iontophoresis and hyperspectral imaging may also be useful in assessing physiological perfusion but are not widely available. There may be a future role for specialized perfusion imaging of these patients, including magnetic resonance

  10. Using Perfusion fMRI to Measure Continuous Changes in Neural Activity with Learning

    ERIC Educational Resources Information Center

    Olson, Ingrid R.; Rao, Hengyi; Moore, Katherine Sledge; Wang, Jiongjiong; Detre, John A.; Aguirre, Geoffrey K.

    2006-01-01

    In this study, we examine the suitability of a relatively new imaging technique, "arterial spin labeled perfusion imaging," for the study of continuous, gradual changes in neural activity. Unlike BOLD imaging, the perfusion signal is stable over long time-scales, allowing for accurate assessment of continuous performance. In addition, perfusion…

  11. Clinical value and severity of myocardial perfusion defects in asymptomatic diabetic patients with negative or weakly positive exercise treadmill test

    PubMed Central

    Zakavi, Seyed Rasoul; Taherpour, Mehdi; Moossavi, Zohreh; Sadeghi, Ramin; Kakhki, Vahidreza Dabbagh; Rokni, Haleh

    2013-01-01

    Objective: Although coronary artery disease (CAD) is the leading cause of death in type 2 diabetic patients, it is frequently asymptomatic. Myocardial perfusion imaging (MPI) is reported to show ischemia in a significant number of asymptomatic diabetic patients. We studied the prevalence and severity of myocardial perfusion defects in asymptomatic diabetic patients and its clinical impact. Methods and patients: One hundred thirty consecutive asymptomatic patients, aged 35-65 years with type 2 diabetes mellitus and with no history of CAD and no cardiac symptoms were recruited in the study. Echocardiography, electrocardiography (ECG), routine laboratory tests and exercise treadmill test (ETT) were performed and patients with weakly positive or negative ETT underwent Dipyridamole MPI. Patients with positive ETT were referred to coronary angiography. Patients were followed for at least 17 months (mean 21.7 months) and any cardiac event was recorded. Results: We studied 81 female and 49 male patients with mean age of 51.8 years. Negative, weakly positive and positive ETT result was noted in 74.3%, 15% and 10.7% respectively. 75% of patients with positive ETT had coronary artery disease in angiography. Gated myocardial perfusion SPECT was done in 106 patients. MPI showed reversible defect in 26.9% of the patients with a mean summed stress score of 3.3±1.8. Follow up completed in 112 patients and only one patient with abnormal MPI underwent coronary angiography followed by PTCA. No cardiac death, MI, UA or hospital admission occurred among our patients during follow up (17-26 months). Mean stress end diastolic volume (EDV) was significantly higher in patients with reversible defect compared to patients without reversible defect based on MPI findings (62.0±31.6 Vs 48.5±18.4 ml, P=0.04). Blood glucose and HbA1c were significantly higher in patients with ischemia compared to patients without ischemia (P<0.05). Meanwhile the ratio of TG to HDL was 6.06±3.2 in ischemic

  12. Abdominal perfusion computed tomography.

    PubMed

    Ogul, Hayri; Bayraktutan, Ummugulsum; Kizrak, Yesim; Pirimoglu, Berhan; Yuceler, Zeynep; Sagsoz, M Erdem; Yilmaz, Omer; Aydinli, Bulent; Ozturk, Gurkan; Kantarci, Mecit

    2013-02-01

    The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis.

  13. Abdominal Perfusion Computed Tomography

    PubMed Central

    Ogul, Hayri; Bayraktutan, Ummugulsum; Kizrak, Yesim; Pirimoglu, Berhan; Yuceler, Zeynep; Sagsoz, M. Erdem; Yilmaz, Omer; Aydinli, Bulent; Ozturk, Gurkan; Kantarci, Mecit

    2013-01-01

    The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis. PMID:25610249

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

    SciTech Connect

    Kahan, A.; Devaux, J.Y.; Amor, B.; Menkes, C.J.; Weber, S.; Nitenberg, A.; Venot, A.; Guerin, F.; Degeorges, M.; Roucayrol, J.C.

    1986-05-29

    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.

  15. Myocardial perfusion defect on thallium-201 imaging in patients with chronic obstructive pulmonary disease

    SciTech Connect

    Mehrotra, P.P.; Weaver, Y.J.; Higginbotham, E.A.

    1983-08-01

    Six patients with angina pectoris had reversible perfusion defects on stress and redistribution thallium imaging. Three patients had a positive electrocardiographic response to exercise. No significant coronary artery lesions were seen on coronary arteriography in any of the six patients. All had mild to moderate hypoxemia at rest and physiologic evidence of chronic obstructive pulmonary disease as defined by the decrease in the ratio of forced expiratory volume at 1 second to forced vital capacity (FEV1/FVC X 100) or decrease in the forced midexpiratory flow rate (FEF25-75), or both. None had clinical findings suggestive of any of the reported causes of positive thallium scans in patients with normal coronary arteriograms. Cellular dysfunction produced by hypoxemia affecting the uptake of thallium seems to be the most likely mechanism of this abnormality.

  16. [Myocardial perfusion imaging by digital subtraction angiography].

    PubMed

    Kadowaki, H; Ishikawa, K; Ogai, T; Katori, R

    1986-03-01

    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; at the R wave of the electrocardiogram, 100 msec before the R wave, and 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 density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Coupling between resting cerebral perfusion and EEG.

    PubMed

    O'Gorman, R L; Poil, S-S; Brandeis, D; Klaver, P; Bollmann, S; Ghisleni, C; Lüchinger, R; Martin, E; Shankaranarayanan, A; Alsop, D C; Michels, L

    2013-07-01

    While several studies have investigated interactions between the electroencephalography (EEG) and functional magnetic resonance imaging BOLD signal fluctuations, less is known about the associations between EEG oscillations and baseline brain haemodynamics, and few studies have examined the link between EEG power outside the alpha band and baseline perfusion. Here we compare whole-brain arterial spin labelling perfusion MRI and EEG in a group of healthy adults (n = 16, ten females, median age: 27 years, range 21-48) during an eyes closed rest condition. Correlations emerged between perfusion and global average EEG power in low (delta: 2-4 Hz and theta: 4-7 Hz), middle (alpha: 8-13 Hz), and high (beta: 13-30 Hz and gamma: 30-45 Hz) frequency bands in both cortical and sub-cortical regions. The correlations were predominately positive in middle and high-frequency bands, and negative in delta. In addition, central alpha frequency positively correlated with perfusion in a network of brain regions associated with the modulation of attention and preparedness for external input, and central theta frequency correlated negatively with a widespread network of cortical regions. These results indicate that the coupling between average EEG power/frequency and local cerebral blood flow varies in a frequency specific manner. Our results are consistent with longstanding concepts that decreasing EEG frequencies which in general map onto decreasing levels of activation.

  18. A reappraisal of retrograde cerebral perfusion

    PubMed Central

    2013-01-01

    Brain protection during aortic arch surgery by perfusing cold oxygenated blood into the superior vena cava was first reported by Lemole et al. In 1990 Ueda and associates first described the routine use of continuous retrograde cerebral perfusion (RCP) in thoracic aortic surgery for the purpose of cerebral protection during the interval of obligatory interruption of anterograde cerebral flow. The beneficial effects of RCP may be its ability to sustain brain hypothermia during hypothermic circulatory arrest (HCA) and removal of embolic material from the arterial circulation of the brain. RCP can offer effective brain protection during HCA for about 40 to 60 minutes. Animal experiments revealed that RCP provided inadequate cerebral perfusion and that neurological recovery was improved with selective antegrade cerebral perfusion (ACP), however, both RCP and ACP provide comparable clinical outcomes regarding both the mortality and stroke rates by risk-adjusted and case-matched comparative study. RCP still remains a valuable adjunct for brain protection during aortic arch repair in particular pathologies and patients. PMID:23977600

  19. Bed-side assessment of cerebral perfusion in stroke patients based on optical monitoring of a dye bolus by time-resolved diffuse reflectance.

    PubMed

    Liebert, A; Wabnitz, H; Steinbrink, J; Möller, M; Macdonald, R; Rinneberg, H; Villringer, A; Obrig, H

    2005-01-15

    We present a minimally invasive optical method, that is, multi-channel time-domain diffuse near-infrared reflectometry of the head to assess cerebral blood perfusion that is applicable at the bed-side and repetitively at short intervals. Following intravenous injection of an ICG bolus, its transit through intra- and extracerebral tissue is monitored based on changes in moments of distributions of times of flight of photons, recorded with a 4-channel instrument simultaneously on both hemispheres. In healthy volunteers, we found that variance of distributions of times of flight of photons is well suited to assess latency and initial slope of the increase in absorption of intracerebral tissue due to the bolus. We successfully applied our method in two patients demonstrating a reversible cerebral perfusion deficit in an ischemic stroke patient who was treated by thrombolysis and in another patient with a permanent impaired unilateral perfusion due to ipsilateral internal carotid artery occlusion. In either case, we observed a difference in bolus transit time between the hemispheres. In the stroke patient, this difference resolved when re-evaluated 1 day after thrombolysis. The study demonstrates the necessity of a technique with sub-nanosecond time resolution to allow for depth discrimination if clinical perfusion monitoring of cerebrovascular diseases is addressed by optical methods.

  20. In vivo nuclear magnetic resonance imaging of myocardial perfusion using the paramagnetic contrast agent manganese gluconate.

    PubMed

    Schaefer, S; Lange, R A; Kulkarni, P V; Katz, J; Parkey, R W; Willerson, J T; Peshock, R M

    1989-08-01

    Previous nuclear magnetic resonance (NMR) imaging studies have indicated that coronary occlusion does not produce sufficient changes in standard tissue relaxation times to allow the detection of acute ischemia. To identify acute myocardial perfusion abnormalities, the use of the paramagnetic agent manganese gluconate combined with calcium gluconate (MnGlu/CaGlu) was investigated in canine models of acute coronary artery occlusion. In vitro studies showed that MnGlu/CaGlu was a more efficient relaxing agent than gadolinium-DTPA (relaxivity of 7.8 versus 5.1 s-1 mM-1) and demonstrated affinity for normal myocardium. The distribution of MnGlu/CaGlu as measured by manganese-54 tracer studies was proportional to myocardial blood flow in both normal and ischemic tissue. Hearts excised from dogs after coronary artery occlusion and administration of 0.035 mM/kg MnGlu/CaGlu were imaged ex vivo using a relatively spin-lattice relaxation time (T1)-weighted gradient reversal technique (repetition time [TR] 50 ms and echo time [TE] 9 ms). These images showed increased signal intensity in the normally perfused myocardium with a mean signal intensity ratio of hypoperfused to normal myocardium of 0.55 +/- 0.12 (mean +/- SD). In vivo images obtained in nine dogs after coronary artery occlusion and administration of the same dose of MnGlu/CaGlu demonstrated the region of hypoperfused myocardium in six dogs with a signal intensity ratio of hypoperfused to normal myocardium of 0.64 +/- 0.23 (p less than 0.05 versus control). When a higher dose of 0.1 mM/kg MnGlu/CaGlu was utilized and in vivo imaging was performed using a relatively spin-spin relaxation time (T2)-weighted (TR gated, TE 60 ms) spin-echo sequence in six dogs, the signal intensity of normal myocardium was decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Endovascular Treatment of a Coronary Artery Bypass Graft to Pulmonary Artery Fistula with Coil Embolization

    SciTech Connect

    Nielson, Jeffery L. Kang, Preet S.

    2006-04-15

    Fistula formation between a coronary artery bypass graft (CABG)and the pulmonary arterial circulation represents a rare cause of recurrent angina in patients following bypass grafting. Therapy has traditionally involved surgical ligation by open thoracotomy. We describe a case of left internal mammary artery-left upper lobe pulmonary artery fistula presenting as early recurrent angina following CABG. The fistula was embolized using platinum coils, resulting in symptomatic relief and improvement in myocardial perfusion on cardiac perfusion scintigraphy. Coil embolization should be considered a therapeutic option in patients with coronary-pulmonary steal syndrome.

  2. Visualization of myocardial perfusion derived from coronary anatomy.

    PubMed

    Termeer, Maurice; Oliván Bescós, Javier; Breeuwer, Marcel; Vilanova, Anna; Gerritsen, Frans; Gröller, M Eduard; Nagel, Eike

    2008-01-01

    Visually assessing the effect of the coronary artery anatomy on the perfusion of the heart muscle in patients with coronary artery disease remains a challenging task. We explore the feasibility of visualizing this effect on perfusion using a numerical approach. We perform a computational simulation of the way blood is perfused throughout the myocardium purely based on information from a three-dimensional anatomical tomographic scan. The results are subsequently visualized using both three-dimensional visualizations and bull's eye plots, partially inspired by approaches currently common in medical practice. Our approach results in a comprehensive visualization of the coronary anatomy that compares well to visualizations commonly used for other scanning technologies. We demonstrate techniques giving detailed insight in blood supply, coronary territories and feeding coronary arteries of a selected region. We demonstrate the advantages of our approach through visualizations that show information which commonly cannot be directly observed in scanning data, such as a separate visualization of the supply from each coronary artery. We thus show that the results of a computational simulation can be effectively visualized and facilitate visually correlating these results to for example perfusion data.

  3. Relationships between high oxygen extraction fraction in the acute stage and final infarction in reversible middle cerebral artery occlusion: an investigation in anesthetized baboons with positron emission tomography.

    PubMed

    Young, A R; Sette, G; Touzani, O; Rioux, P; Derlon, J M; MacKenzie, E T; Baron, J C

    1996-11-01

    Studies in humans suggest that regions that show maximal increases in brain oxygen extraction fraction (OEF) in the hours following an ischemic episode are those most vulnerable for infarction and are often, although not always, associated with the final site of infarction. To clarify this issue, we followed the hemodynamic and metabolic characteristics of regions with an initially maximally increased OEF and compared them with the ultimately infarcted region in an experimental stroke model. Positron emission tomography (PET) was used to obtain functional images of the brain prior to and following reversible unilateral middle cerebral artery occlusion (MCAO) in 11 anesthetized baboons. To model early reperfusion, the clips were removed 6 h after occlusion. Successive measurements of regional CBF (rCBF), regional CMRO2 (rCMRO2), regional cerebral blood volume, and regional OEF (rOEF) were performed during the acute (up to 2 days) and chronic (> 15 days) stage. Late magnetic resonance imaging (MRI) scans (co-registered with PET) were obtained to identify infarction. Reversible MCAO produced an MRI-measurable infarction in 6 of 11 baboons; the others had no evidence of ischemic damage. Histological analysis confirmed the results of the MRI investigation but failed to show any evidence of cortical ischemic damage. The lesion was restricted to the head of the caudate nucleus, internal capsule, and putamen. The infarct volume obtained was 0.58 +/- 0.31 cm3. The infarcts were situated in the deep MCA territory, while the area of initially maximally increased OEF was within the cortical mantle. The mean absolute rCBF value in the infarct region of interest (ROI) was not significantly lower than in the highest-OEF ROI until 1-2 days post-MCAO. Cerebral metabolism in the deep MCA territory was always significantly lower than that of the cortical mantle; decreases in CMRO2 in the former region were evident as early as 1 h post-MCAO. In the cortical mantle, the rOEF was

  4. Intracranial Arteries - Anatomy and Collaterals.

    PubMed

    Liebeskind, David S; Caplan, Louis R

    2016-01-01

    Anatomy, physiology, and pathophysiology are inextricably linked in patients with intracranial atherosclerosis. Knowledge of abnormal or pathological conditions such as intracranial atherosclerosis stems from detailed recognition of the normal pattern of vascular anatomy. The vascular anatomy of the intracranial arteries, both at the level of the vessel wall and as a larger structure or conduit, is a reflection of physiology over time, from in utero stages through adult life. The unique characteristics of arteries at the base of the brain may help our understanding of atherosclerotic lesions that tend to afflict specific arterial segments. Although much of the knowledge regarding intracranial arteries originates from pathology and angiography series over several centuries, evolving noninvasive techniques have rapidly expanded our perspective. As each imaging modality provides a depiction that combines anatomy and flow physiology, it is important to interpret each image with a solid understanding of typical arterial anatomy and corresponding collateral routes. Compensatory collateral perfusion and downstream flow status have recently emerged as pivotal variables in the clinical management of patients with atherosclerosis. Ongoing studies that illustrate the anatomy and pathophysiology of these proximal arterial segments across modalities will help refine our knowledge of the interplay between vascular anatomy and cerebral blood flow. Future studies may help elucidate pivotal arterial factors far beyond the degree of stenosis, examining downstream influences on cerebral perfusion, artery-to-artery thromboembolic potential, amenability to endovascular therapies and stent conformation, and the propensity for restenosis due to biophysical factors.

  5. Procedure for Human Saphenous Veins Ex Vivo Perfusion and External Reinforcement

    PubMed Central

    Berard, Xavier; Alonso, Florian; Haefliger, Jacques-Antoine

    2014-01-01

    The mainstay of contemporary therapies for extensive occlusive arterial disease is venous bypass graft. However, its durability is threatened by intimal hyperplasia (IH) that eventually leads to vessel occlusion and graft failure. Mechanical forces, particularly low shear stress and high wall tension, are thought to initiate and to sustain these cellular and molecular changes, but their exact contribution remains to be unraveled. To selectively evaluate the role of pressure and shear stress on the biology of IH, an ex vivo perfusion system (EVPS) was created to perfuse segments of human saphenous veins under arterial regimen (high shear stress and high pressure). Further technical innovations allowed the simultaneous perfusion of two segments from the same vein, one reinforced with an external mesh. Veins were harvested using a no-touch technique and immediately transferred to the laboratory for assembly in the EVPS. One segment of the freshly isolated vein was not perfused (control, day 0). The two others segments were perfused for up to 7 days, one being completely sheltered with a 4 mm (diameter) external mesh. The pressure, flow velocity, and pulse rate were continuously monitored and adjusted to mimic the hemodynamic conditions prevailing in the femoral artery. Upon completion of the perfusion, veins were dismounted and used for histological and molecular analysis. Under ex vivo conditions, high pressure perfusion (arterial, mean = 100 mm Hg) is sufficient to generate IH and remodeling of human veins. These alterations are reduced in the presence of an external polyester mesh. PMID:25350681

  6. Quantitative myocardial perfusion SPECT.

    PubMed

    Tsui, B M; Frey, E C; LaCroix, K J; Lalush, D S; McCartney, W H; King, M A; Gullberg, G T

    1998-01-01

    In recent years, there has been much interest in the clinical application of attenuation compensation to myocardial perfusion single photon emission computed tomography (SPECT) with the promise that accurate quantitative images can be obtained to improve clinical diagnoses. The different attenuation compensation methods that are available create confusion and some misconceptions. Also, attenuation-compensated images reveal other image-degrading effects including collimator-detector blurring and scatter that are not apparent in uncompensated images. This article presents basic concepts of the major factors that degrade the quality and quantitative accuracy of myocardial perfusion SPECT images, and includes a discussion of the various image reconstruction and compensation methods and misconceptions and pitfalls in implementation. The differences between the various compensation methods and their performance are demonstrated. Particular emphasis is directed to an approach that promises to provide quantitative myocardial perfusion SPECT images by accurately compensating for the 3-dimensional (3-D) attenuation, collimator-detector response, and scatter effects. With advances in the computer hardware and optimized implementation techniques, quantitatively accurate and high-quality myocardial perfusion SPECT images can be obtained in clinically acceptable processing time. Examples from simulation, phantom, and patient studies are used to demonstrate the various aspects of the investigation. We conclude that quantitative myocardial perfusion SPECT, which holds great promise to improve clinical diagnosis, is an achievable goal in the near future.

  7. Myocardial perfusion imaging with thallium-201: correlation with coronary arteriography and electrocardiography

    PubMed Central

    Sternberg, Leonard; Wald, Robert W.; Feiglin, David H.I.; Morch, John E.

    1978-01-01

    Myocardial perfusion imaging with thallium-201 and electrocardiography with the subject at rest and undergoing submaximal treadmill exercise were performed in 19 men and 3 women. Selective coronary arteriography and left ventriculography showed that 7 had normal coronary arteries and 15 had coronary artery disease. The 11 persons with electrocardiographic evidence of an old myocardial infarct (q waves) had a perfusion defect at rest in the area of the infarct and a segmental abnormality of wall motion apparent on the left ventriculogram corresponding to the perfusion defect. Myocardial perfusion imaging and electrocardiography were equally sensitive in detecting coronary artery disease in exercising individuals: perfusion defects were noted in 7 of the 15 persons with coronary artery disease, and diagnostic ST-segment depression was present in 8 of the 15. Combination of the results of the two tests with exercise permitted the identification of 11 of the 15 persons and improved the sensitivity. Combination of the results of rest and exercise imaging and electrocardiography permitted the identification of 94% of the patients with coronary artery disease. Myocardial perfusion imaging with 201TI in the subject at rest is a sensitive indicator of previous myocardial infarction. Imaging after the subject has exercised is a useful adjunct to conventional exercise electrocardiography, especially in those whose exercise electrocardiogram is non-interpretable. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5 PMID:630487

  8. Proton and fluorine NMR imaging for the assessment of myocardial perfusion

    SciTech Connect

    Horner, B.S.D.

    1985-01-01

    A high field, small bore NMR spectrometer was converted to an imaging system for the detection of fluorine and protons in phantoms and small biological samples. The modified spectrometer system was used to image various phantoms for the assessment of imaging performance. After assessment of the imaging system performance, a water soluble fluorinated compound of relatively low toxicity was investigated for use as an imaging agent for the detection of myocardial perfusion. New Zealand white rabbits were used as the model. Hearts were rapidly extracted and hung via the aorta to a perfusion apparatus which was capable of prolonging heart function throughout the course of the experiment. Perfusion with a standard nutrient solution was followed either by perfusion with a solution to which the fluorinated compound had been added or by ligation of the left coronary artery with subsequent perfusion with the fluorinated compound in perfusate solution. The hearts were then sectioned and imaged. The ligation of the left coronary artery produced a region of impaired perfusion in the left ventricular wall and parts of the septum. The regions of reduced perfusion appeared in the F-19 NMR images as areas of reduced intensity. Proton images of the tissue sections were also obtained for comparison. It was found that infarcted regions may be best visualized by combining the fluorine and proton images. Infarct damage was verified by Gentian violet stain. Relaxation times of fluorine and protons were measured both in perfused tissue and in various concentration solutions.

  9. Ex vivo lung perfusion.

    PubMed

    Reeb, Jeremie; Cypel, Marcelo

    2016-03-01

    Lung transplantation is an established life-saving therapy for patients with end-stage lung disease. Unfortunately, greater success in lung transplantation is hindered by a shortage of lung donors and the relatively poor early-, mid-, and long-term outcomes associated with severe primary graft dysfunction. Ex vivo lung perfusion has emerged as a modern preservation technique that allows for a more accurate lung assessment and improvement in lung quality. This review outlines the: (i) rationale behind the method; (ii) techniques and protocols; (iii) Toronto ex vivo lung perfusion method; (iv) devices available; and (v) clinical experience worldwide. We also highlight the potential of ex vivo lung perfusion in leading a new era of lung preservation.

  10. [Portable peristaltic perfusion pumps].

    PubMed

    Magallón Pedrera, I; Soto Torres, I

    1999-11-01

    Portable peristaltic perfusion pumps allow one to administer pharmaceuticals in hospitals as well as in primary health care centers and furthermore these pumps present multiple advantages for patients and their families since they make it possible to carry out treatment in a patient's home while at the same time lowering the costs involved. The authors analyze the most out standing aspects of portable peristaltic perfusion pumps along with their characteristics, installation, programming, and how to turn them on; in addition, the authors list the maintenance care which these pumps require.

  11. Inert gas analysis of ventilation-perfusion matching during hemodialysis.

    PubMed Central

    Ralph, D D; Ott, S M; Sherrard, D J; Hlastala, M P

    1984-01-01

    The mechanism of hypoxemia during hemodialysis was investigated by the multiple inert gas elimination technique in anesthetized, paralyzed, mechanically ventilated dogs. Profound leukopenia occurred in the first hour of a 2-h hemodialysis with a cuprophan membrane and dialysate that contained acetate. Arterial partial pressure of O2 and CO2 and oxygen consumption remained unchanged during dialysis. Pulmonary carbon dioxide elimination and lung respiratory exchange ratio decreased with the initiation of dialysis, remained depressed throughout the duration of dialysis, and returned to predialysis levels after the cessation of dialysis. Cardiac output diminished during dialysis but did not return to base-line levels after dialysis. Multiple indices calculated from inert gas analysis revealed no ventilation-perfusion mismatching during dialysis. The shunt and perfusion to regions of low alveolar ventilation-to-perfusion ratio (VA/Q) were unchanged during dialysis. There was no change in the mean or standard deviation of the profile of the percentage of total perfusion to regions of the lung that had VA/Q near 1.0; nor was there any increase in the directly calculated arterial-alveolar partial pressure differences for the inert gases during dialysis. Dead space became mildly elevated during dialysis. These results show that during dialysis with controlled ventilation there is no ventilation-perfusion mismatching that leads to hypoxemia. During spontaneous ventilation any hypoxemia must occur due to hypoventilation secondary to the CO2 exchange by the dialyzer and subsequent reduction in pulmonary CO2 exchange. PMID:6715542

  12. Marvels, Mysteries, and Misconceptions of Vascular Compensation to Peripheral Artery Occlusion

    PubMed Central

    ZIEGLER, MATTHEW A.; DISTASI, MATTHEW R.; BILLS, RANDALL G.; MILLER, STEVEN J.; ALLOOSH, MOUHAMAD; MURPHY, MICHAEL P.; AKINGBA, A. GEORGE; STUREK, MICHAEL; DALSING, MICHAEL C.; UNTHANK, JOSEPH L.

    2010-01-01

    Peripheral arterial disease is a major health problem and there is a significant need to develop therapies to prevent its progression to claudication and critical limb ischemia. Promising results in rodent models of arterial occlusion have generally failed to predict clinical success and led to questions of their relevance. While sub-optimal models may have contributed to the lack of progress, we suggest that advancement has also been hindered by misconceptions of the human capacity for compensation and the specific vessels which are of primary importance. We present and summarize new and existing data from humans, Ossabaw miniature pigs, and rodents which provide compelling evidence that natural compensation to occlusion of a major artery (i) may completely restore perfusion, (ii) occurs in specific pre-existing small arteries, rather than the distal vasculature, via mechanisms involving flow-mediated dilation and remodeling (iii) is impaired by cardiovascular risk factors which suppress the flow-mediated mechanisms and (iv) can be restored by reversal of endothelial dysfunction. We propose that restoration of the capacity for flow-mediated dilation and remodeling in small arteries represents a largely unexplored potential therapeutic opportunity to enhance compensation for major arterial occlusion and prevent the progression to critical limb ischemia in the peripheral circulation. PMID:20141596

  13. A patient-specific visualization tool for comprehensive analysis of coronary CTA and perfusion MRI data

    NASA Astrophysics Data System (ADS)

    Kirisli, H. A.; Gupta, V.; Kirschbaum, S.; Neefjes, L.; van Geuns, R. J.; Mollet, N.; Lelieveldt, B. P. F.; Reiber, J. H. C.; van Walsum, T.; Niessen, W. J.

    2011-03-01

    Cardiac magnetic resonance perfusion imaging (CMR) and computed tomography angiography (CTA) are widely used to assess heart disease. CMR is used to measure the global and regional myocardial function and to evaluate the presence of ischemia; CTA is used for diagnosing coronary artery disease, such as coronary stenoses. Nowadays, the hemodynamic significance of coronary artery stenoses is determined subjectively by combining information on myocardial function with assumptions on coronary artery territories. As the anatomy of coronary arteries varies greatly between individuals, we developed a patient-specific tool for relating CTA and perfusion CMR data. The anatomical and functional information extracted from CTA and CMR data are combined into a single frame of reference. Our graphical user interface provides various options for visualization. In addition to the standard perfusion Bull's Eye Plot (BEP), it is possible to overlay a 2D projection of the coronary tree on the BEP, to add a 3D coronary tree model and to add a 3D heart model. The perfusion BEP, the 3D-models and the CTA data are also interactively linked. Using the CMR and CTA data of 14 patients, our tool directly established a spatial correspondence between diseased coronary artery segments and myocardial regions with abnormal perfusion. The location of coronary stenoses and perfusion abnormalities were visualized jointly in 3D, thereby facilitating the study of the relationship between the anatomic causes of a blocked artery and the physiological effects on the myocardial perfusion. This tool is expected to improve diagnosis and therapy planning of early-stage coronary artery disease.

  14. Adenosine thallium 201 myocardial perfusion scintigraphy

    SciTech Connect

    Verani, M.S. )

    1991-07-01

    Pharmacologic coronary vasodilation as an adjunct to myocardial perfusion imaging has become increasingly important in the evaluation of patients with coronary artery disease, in view of the large number of patients who cannot perform an adequate exercise test or in whom contraindications render exercise inappropriate. Adenosine is a very potent coronary vasodilator and when combined with thallium 201 scintigraphy produces images of high quality, with the added advantages of a very short half-life (less than 10 seconds) and the ability to adjust the dose during the infusion, which may enhance safety and curtail the duration of side effects. The reported sensitivity and specificity of adenosine thallium 201 scintigraphy for the detection of coronary artery disease are high and at least comparable with imaging after exercise or dipyridamole administration. 23 refs.

  15. Transport of calcium across the dually perfused placenta of the rat.

    PubMed Central

    Stulc, J; Stulcová, B; Svihovec, J

    1990-01-01

    1. A rat placenta was dually perfused in situ with modified Krebs fluid. Perfusion was carried out through the femoral artery on the maternal side and through the umbilical artery on the fetal side. 2. Transfer of 45Ca2+ and [3H]L-glucose across the placenta was measured in the maternal-fetal direction. The transcellular component of the maternal-fetal transport of Ca2+, Jmf,tc, was estimated from transfer rates of the two tracers and from Ca2+ concentration in maternal perfusate, [Ca2+]m. 3. At [Ca2+]m of 1.1 mM (physiological concentration of Ca2+ in plasma) Jmf,tc was 92.4 +/- 13.7 nmol min-1 (mean +/- S.D.), which is about 90% of the transport expected in an intact placenta. The permeability-surface area product (PS) of the placenta to [3H]L-glucose was 13.8 +/- 3.9 microliters min-1, about 4 times higher than that expected in intact placenta. 4. Transport of 45Ca2+ changed rapidly when [Ca2+]m was varied. Kinetic constants of the transcellular transport of Ca2+ are the Michaelis constant, Km, = 0.45 mM and the maximum rate of transport, Vmax, = 116 nmol min-1. It follows from this that at physiological levels of Ca2+, transport of Ca2+ to the fetus is relatively independent of changes in [Ca2+]m. 5. Strontium and barium (SrCl2 and BaCl2, 1 mM) decreased Jmf,tc; the response was prompt and reversible. Magnesium (2 mM) had no effect. Maternal-fetal transport of 85Sr2+ and 133Ba2+ was decreased rapidly and reversibly by elevating [Ca2+]m from 0.35 to 2 mM. These observations suggest that Sr2+ and Ba2+ are transported across the placenta by the Ca2+ transport system. This means that the transport is not substrate specific. 6. Cadmium (1 mM-CdCl2) decreased Jmf,tc irreversibly with some latency. The slowness of the response suggests a non-competitive inhibition. Cadmium (0.02 mM-CdCl2) was without effect on Jmf,tc. 7. A Ca2+ channel blocker, nifedipine (10 microM), administered to the maternal side had no effect on Jmf,tc. PMID:2324986

  16. Gastric air contrast: useful adjunct to hepatic artery scintigraphy

    SciTech Connect

    Wahl, R.L.; Ziessman, H.A.; Juni, J.; Lahti, D.

    1984-08-01

    The utility of scintigraphic views obtained after administration of sodium bicarbonate-citric acid-simethicone crystals (E-Z-GAS) for the determination of gastric extrahepatic perfusion was evaluated in 20 technetium-99m macroaggregated albumin hepatic arterial perfusion studies performed in 19 patients. These crystals produce carbon dioxide gas, distend the stomach, and allow better delineation of gastric activity (extrahepatic perfusion to the stomach). Conversely, a lack of change in activity in the left upper quadrant after the effervescent crystals have been ingested suggests no gastric activity (and no extrahepatic perfusion to the stomach). These air-contrast views added useful information in 16 of 20 studies. Air contrast views of the stomach can be extremely helpful in verifying or excluding the diagnosis of gastric extrahepatic perfusion on technetium-99m macroaggregated albumin hepatic arterial perfusion studies.

  17. Nifedipine improves blood flow and oxygen supply, but not steady-state oxygenation of tumours in perfusion pressure-controlled isolated limb perfusion.

    PubMed

    Thews, O; Hummel, M; Kelleher, D K; Lecher, B; Vaupel, P

    2002-12-02

    Isolated limb perfusion allows the direct application of therapeutic agents to a tumour-bearing extremity. The present study investigated whether the dihydropyridine-type Ca(2+)-channel blocker nifedipine could improve blood flow and oxygenation status of experimental tumours during isolated limb perfusion. Perfusion was performed by cannulation of the femoral artery and vein in rats bearing DS-sarcoma on the hind foot dorsum. Perfusion rate was adjusted to maintain a perfusion pressure of 100-140 mmHg throughout the experiment. Following equilibration, nifedipine was continuously infused for 30 min (8.3 microg min(-1) kg(-1) BW). During constant-pressure isolated limb perfusion, nifedipine can significantly increase perfusion rate (+100%) and RBC flux (+60%) through experimental leg tumours. "Steal phenomena" in favour of the surrounding normal tissue and oedema formation were not observed. Despite the increased oxygen availability (+63%) seen upon application of this calcium channel blocker, nifedipine does not result in a substantial reduction of tumour hypoxia, most probably due to an increase in O(2) uptake with rising O(2) supply to the tumour-bearing hind limb. Nifedipine application during isolated limb perfusion can enhance tumour microcirculation and may therefore promote the delivery (pharmacokinetics) of anti-cancer drugs to the tumour and by this improve the efficacy of pressure-controlled isolated limb perfusion.

  18. Ex vivo normothermic machine perfusion and viability testing of discarded human donor livers.

    PubMed

    op den Dries, S; Karimian, N; Sutton, M E; Westerkamp, A C; Nijsten, M W N; Gouw, A S H; Wiersema-Buist, J; Lisman, T; Leuvenink, H G D; Porte, R J

    2013-05-01

    In contrast to traditional static cold preservation of donor livers, normothermic machine perfusion may reduce preservation injury, improve graft viability and potentially allows ex vivo assessment of graft viability before transplantation. We have studied the feasibility of normothermic machine perfusion in four discarded human donor livers. Normothermic machine perfusion consisted of pressure and temperature controlled pulsatile perfusion of the hepatic artery and continuous portal perfusion for 6 h. Two hollow fiber membrane oxygenators provided oxygenation of the perfusion fluid. Biochemical markers in the perfusion fluid reflected minimal hepatic injury and improving function. Lactate levels decreased to normal values, reflecting active metabolism by the liver (mean lactate 10.0 ± 2.3 mmol/L at 30 min to 2.3 ± 1.2 mmol/L at 6 h). Bile production was observed throughout the 6 h perfusion period (mean rate 8.16 ± 0.65 g/h after the first hour). Histological examination before and after 6 h of perfusion showed well-preserved liver morphology without signs of additional hepatocellular ischemia, biliary injury or sinusoidal damage. In conclusion, this study shows that normothermic machine perfusion of human donor livers is technically feasible. It allows assessment of graft viability before transplantation, which opens new avenues for organ selection, therapeutic interventions and preconditioning.

  19. Assessment of the ability of myocardial contrast echocardiography with harmonic power Doppler imaging to identify perfusion abnormalities in patients with Kawasaki disease at rest and during dipyridamole stress.

    PubMed

    Ishii, M; Himeno, W; Sawa, M; Iemura, M; Furui, J; Muta, H; Sugahara, Y; Egami, K; Akagi, T; Ishibashi, M; Kato, H

    2002-01-01

    The aim of our study was to assess the ability of myocardial contrast echocardiography (MCE) with harmonic power Doppler imaging (HPDI) to identify perfusion abnormalities in patients with Kawasaki disease at rest and during pharmacological stress imaging with dipyridamole. Results were compared with those of 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) imaging as the clinical reference standard. MCE with HPDI was performed on 20 patients with a history of Kawasaki disease. Images were obtained at baseline and during dipyridamole infusion (0.56 mg x kg(-1)) in the apical two- and four-chamber views. Myocardial opacification suitable for the analysis was obtained in all patients. Nine patients with stenotic lesions had a reversible defect after dipyridamole infusion detected by both MCE with HPDI and SPECT, and 3 patients with a history of myocardial infarction had a partially or completely irreversible defect detected by both methods. Three patients with coronary aneurysm without stenotic lesion, 4 patients with regressed coronary aneurysm, and 2 patients with normal coronary artery in acute phase also had normal perfusion at rest and after pharmacological stress by both methods. A 96% concordance (kappa = 0.87) was obtained when comparing the respective segmental perfusion scores using the two methods at baseline, and an 86% concordance (kappa = 0.81) was obtained at postdipyridamole infusion. After combining baseline and postdipyridamole images, each segment was labeled as having normal perfusion, irreversible defects, or reversible defects. Using these classifications, concordance for the two methods was 92% (kappa = 0.87). MCE with HPDI is a safe and feasible method by which to detect asymptomatic ischemia due to severe stenotic lesion, and it may be an important addition to the modalities used to identify patients at risk for myocardial infarction as a complication of Kawasaki disease.

  20. Spinal-cord syndrome due to non-compressive Paget's disease of bone: a spinal-artery steal phenomenon reversible with calcitonin.

    PubMed

    Herzberg, L; Bayliss, E

    1980-07-05

    A 76-year-old man had progressive low back pain, leg weakness, and sensory loss. Radiology showed changes consistent with wide-spread Paget's disease, but no cord compression or involvement of nerve roots was detected by myelography or computerised axial tomography. His symptoms were relieved within 12 days of starting 100 MRC units of subcutaneous salmon calcitonin and recurred when calcitonin was discontinued for 5 days. The improvement continued on calcitonin treatment for 1 year, with falls in serum alkaline phosphatase and urinary hydroxyproline excretion. It is suggested that calcitonin treatment, in reducing the abnormally high metabolic activity of the diseased bone, and hence its vascular perfusion, allows more blood to reach the spinal cord.

  1. Coronary Arteries

    MedlinePlus

    ... and animations for grades K-6. The Coronary Arteries Coronary Circulation The heart muscle, like every other ... into two main coronary blood vessels (also called arteries). These coronary arteries branch off into smaller arteries, ...

  2. Computed tomography perfusion imaging in spectacular shrinking deficit.

    PubMed

    Lee, Vivien H; John, Sayona; Mohammad, Yousef; Prabhakaran, Shyam

    2012-02-01

    Spectacular shrinking deficit (SSD) is characterized by abrupt onset of a major hemispheric stroke syndrome, followed by dramatic and rapid improvement. We retrospectively identified patients with SSD diagnosed at our institution between December 1, 2007, and June 30, 2009. We reviewed computed tomography perfusion (CTP) imaging to determine perfusion defect as a measure of initial ischemic penumbra, and magnetic resonance imaging diffusion-weighted imaging (DWI) to determine the final infarct core. Among the 472 consecutive ischemic stroke patients, 126 (27%) presented with major hemispheric ischemic stroke syndrome, defined as National Institutes of Health Stroke Scale score (NIHSS) ≥8 in the territory of the middle cerebral artery (MCA) or internal carotid artery (ICA). Out of these patients, we identified 8 SSD patients with available CTP data. In these 8 patients, the mean time to dramatic recovery was 3.4 hours (range, 0.75-7 hours), and the mean time from onset to CTP was 12.7 hours (range, 3-30 hours). All 8 patients had perfusion abnormalities in portions of the MCA territory (partial MCA territory in 5 patients and complete MCA territory in 3 patients). The mean time from onset to MRI DWI was 15.5 hours (range, 7.9-34 hours). Restricted diffusion was present in all patients in the corresponding MCA distribution. Vascular imaging revealed MCA occlusion in 2 patients. Cervical vascular imaging revealed carotid occlusion in 2 patients and high-grade carotid stenosis in 2 patients. The stroke mechanisms were cardioembolism in 2 patients, large artery in 4 patients, and unknown in 2 patients. Four patients had repeat CTP imaging available that demonstrated eventual resolution of the perfusion defect. SSD is associated with a "shrinking" clinical syndrome and a "shrinking" perfusion pattern on CTP that lags behind clinical recovery. CTP imaging corroborates that a larger territory is at risk in SSD and contributes to better understanding of SSD.

  3. Modelling Brain Temperature and Perfusion for Cerebral Cooling

    NASA Astrophysics Data System (ADS)

    Blowers, Stephen; Valluri, Prashant; Marshall, Ian; Andrews, Peter; Harris, Bridget; Thrippleton, Michael

    2015-11-01

    Brain temperature relies heavily on two aspects: i) blood perfusion and porous heat transport through tissue and ii) blood flow and heat transfer through embedded arterial and venous vasculature. Moreover brain temperature cannot be measured directly unless highly invasive surgical procedures are used. A 3D two-phase fluid-porous model for mapping flow and temperature in brain is presented with arterial and venous vessels extracted from MRI scans. Heat generation through metabolism is also included. The model is robust and reveals flow and temperature maps in unprecedented 3D detail. However, the Karmen-Kozeny parameters of the porous (tissue) phase need to be optimised for expected perfusion profiles. In order to optimise the K-K parameters a reduced order two-phase model is developed where 1D vessels are created with a tree generation algorithm embedded inside a 3D porous domain. Results reveal that blood perfusion is a strong function of the porosity distribution in the tissue. We present a qualitative comparison between the simulated perfusion maps and those obtained clinically. We also present results studying the effect of scalp cooling on core brain temperature and preliminary results agree with those observed clinically.

  4. Dynamic CT head phantom for perfusion and angiography studies

    NASA Astrophysics Data System (ADS)

    Russell, K.; Blazeski, A.; Dannecker, K.; Lee, Q. Y.; Holscher, C.; Donahue, C.; van Kampen, W.

    2010-03-01

    Contrast imaging is a compelling enhancement for the portable, flat panel-based brain CT scanner currently under development at Xoran. Due to the relative low temporal resolution of flat panel detectors, enabling tomographic imaging on such platform requires optimizing the imaging and injection protocols. A dynamic CT head phantom was designed to facilitate this task. The Dynamic Perfusion and Angiography Model (PAM), mimics tissue attenuation in CT images, provides physiological timing for angiography and perfusion studies, and moves fluid with properties similar to those of blood. The design consists of an arterial system, which contains bifurcating vessels that feed into perfusion chambers, mimicking blood flow through capillaries and smaller vessels, and a venous system, which is symmetrical to the arterial side and drains the perfusion chambers. The variation of geometry and flow rate in the phantom provides the physiological total time that fluid spends in the head, and the difference in material densities correlates to CT numbers for biological tissues. This paper discusses the design of Dynamic PAM and shows experimental results demonstrating its ability to realistically simulate blood flow. Results of dynamic imaging studies of the phantom are also presented.

  5. FM19G11 reverses endothelial dysfunction in rat and human arteries through stimulation of the PI3K/Akt/eNOS pathway, independently of mTOR/HIF-1α activation

    PubMed Central

    El Assar, M; Sánchez-Puelles, J M; Royo, I; López-Hernández, E; Sánchez-Ferrer, A; Aceña, J L; Rodríguez-Mañas, L; Angulo, J

    2015-01-01

    Background and Purpose FM19G11 up-regulates mammalian target of rapamycin (mTOR)/hypoxia inducible factor-1α (HIF-1α) and PI3K/Akt pathways, which are involved in endothelial function. We evaluated the effects of FM19G11 on defective endothelial vasodilatation in arteries from rats and humans and investigated the mechanisms involved. Experimental Approach Effects of chronic in vivo administration of FM19G11 on aortic endothelial vasodilatation were evaluated together with ex vivo treatment in aortic and mesenteric arteries from control and insulin-resistant rats (IRR). Its effects on vasodilator responses of penile arteries (HPRAs) and corpus cavernosum (HCC) from men with vasculogenic erectile dysfunction (ED) (model of human endothelial dysfunction) were also evaluated. Vascular expression of phosphorylated-endothelial NOS (p-eNOS), phosphorylated-Akt (p-Akt) and HIF-1α was determined by immunodetection and cGMP by elisa. Key Results Chronic administration of FM19G11 reversed the impaired endothelial vasodilatation in IRR. Ex vivo treatment with FM19G11 also significantly improved endothelium-dependent vasodilatation in aorta and mesenteric arteries from IRR. These effects were accompanied by the restoration of p-eNOS and cGMP levels in IRR aorta and were prevented by either NOS or PI3K inhibition. p-Akt and p-eNOS contents were increased by FM19G11 in aortic endothelium of IRR. FM19G11-induced restoration of endothelial vasodilatation was unaffected by mTOR/HIF-1α inhibitors. FM19G11 also restored endothelial vasodilatation in HPRA and HCC from ED patients. Conclusions and Implications Stimulation of the PI3K/Akt/eNOS pathway by FM19G11 alleviates impaired NO-mediated endothelial vasodilatation in rat and human arteries independently of mTOR/HIF-1α activation. This pharmacological strategy could be beneficial for managing pathological conditions associated with endothelial dysfunction, such as ED. PMID:25363469

  6. A panel data set on harvest and perfusion decellularization of porcine rectus abdominis

    PubMed Central

    Zhang, Jian; Cheng, Wen Yue; Hu, Zhi Qian; Turner, Neill J.; Zhang, Li; Wang, Qiang; Badylak, Stephen F.

    2016-01-01

    In this dataset, we particularly depicted the harvest and perfusion decellularization of porcine rectus abdominis (RA), accompanied with displaying of the retained vascular trees within the perfusion-decellularized skeletal muscle matrix (pM-ECM) using vascular corrosion casting. In addition, several important tips for successful pM-ECM preparation were emphasized, which including using anatomically isolated skeletal muscle as tissue source with all main feeding and draining vessels perfused, preserving the internal microcirculation availability, aseptic technique and pyrogen free in all steps, sequential perfusion via artery or vein, and longtime washing after decellularization. The data are supplemental to our original research article describing detailed associations of pM-ECM as a clinically relevant scale, three-dimensional scaffold with a vascular network template for tissue-specific regeneration, “Perfusion-decellularized skeletal muscle as a three-dimensional scaffold with a vascular network template” Zhang et al. (2016) [1]. PMID:27158653

  7. Continuous monitoring of cortical perfusion by laser Doppler flowmetry in ventilated patients with head injury.

    PubMed Central

    Kirkpatrick, P J; Smielewski, P; Czosnyka, M; Pickard, J D

    1994-01-01

    A method for monitoring cortical perfusion by laser Doppler flowmetry (LDF) in the neurointensive care unit is described. Out of 22 patients with head injuries, reliable and long term recordings were obtained in 16. Laser Doppler flowmetry registered changes in cortical microcirculatory flow in response to spontaneous waves of raised intracranial pressure, and to therapeutic manoeuvres that altered the cerebral perfusion pressure. Comparisons of variations in flux signal with cerebral perfusion pressure provided an indication of the autoregulatory state of the cortical microcirculation, and analysis of raw LDF data demonstrated an autoregulatory breakpoint of cerebral perfusion pressure of 58 mm Hg, below which cortical perfusion failed. Although middle cerebral artery flow velocities were generally tightly coupled with LDF signal changes, episodes of uncoupling were seen. The potential uses and limitations of LDF in the neurointensive care setting are discussed. Images PMID:7964816

  8. Magnetic resonance cardiac perfusion imaging-a clinical perspective.

    PubMed

    Hunold, Peter; Schlosser, Thomas; Barkhausen, Jörg

    2006-08-01

    Coronary artery disease (CAD) with its clinical appearance of stable or unstable angina and acute myocardial infarction is the leading cause of death in developed countries. In view of increasing costs and the rising number of CAD patients, there has been a major interest in reliable non-invasive imaging techniques to identify CAD in an early (i.e. asymptomatic) stage. Since myocardial perfusion deficits appear very early in the "ischemic cascade", a major breakthrough would be the non-invasive quantification of myocardial perfusion before functional impairment might be detected. Therefore, there is growing interest in other, target-organ-specific parameters, such as relative and absolute myocardial perfusion imaging. Magnetic resonance (MR) imaging has been proven to offer attractive concepts in this respect. However, some important difficulties have not been resolved so far, which still causes uncertainty and prevents the broad application of MR perfusion imaging in a clinical setting. This review explores recent technical developments in MR hardware, software and contrast agents, as well as their impact on the current and future clinical status of MR imaging of first-pass myocardial perfusion imaging.

  9. Ultrasound perfusion analysis combining bolus-tracking and burst-replenishment.

    PubMed

    Jirik, Radovan; Nylund, Kim; Gilja, Odd H; Mezl, Martin; Harabis, Vratislav; Kolar, Radim; Standara, Michal; Taxt, Torfinn

    2013-02-01

    A new signal model and processing method for quantitative ultrasound perfusion analysis is presented, called bolus-and-burst. The method has the potential to provide absolute values of blood flow, blood volume, and mean transit time. Furthermore, it provides an estimate of the local arterial input function which characterizes the arterial tree, allowing accurate estimation of the bolus arrival time. The method combines two approaches to ultrasound perfusion analysis: bolus-tracking and burst-replenishment. A pharmacokinetic model based on the concept of arterial input functions and tissue residue functions is used to model both the bolus and replenishment parts of the recording. The pharmacokinetic model is fitted to the data using blind deconvolution. A preliminary assessment of the new perfusion-analysis method is presented on clinical recordings.

  10. Noninvasive Imaging in Coronary Artery Disease

    PubMed Central

    Heo, Ran; Nakazato, Ryo; Kalra, Dan; Min, James K.

    2014-01-01

    Noninvasive cardiac imaging is widely used to evaluate the presence of coronary artery disease. Recently, with improvements in imaging technology, noninvasive imaging has also been used for evaluation of the presence, severity, and prognosis of coronary artery disease. Coronary CT angiography and MRI of coronary arteries provide an anatomical assessment of coronary stenosis, whereas the hemodynamic significance of a coronary artery stenosis can be assessed by stress myocardial perfusion imaging, such as SPECT/PET and stress MRI. For appropriate use of multiple imaging modalities, the strengths and limitations of each modality are discussed in this review. PMID:25234083

  11. Lost unilateral capillary perfusion during nonpulsatile pulmonary circulation: successful recovery by oral sildenafil.

    PubMed

    Celik, Levent; Papakostas, Konstantin; Lentschig, Markus; Hraska, Victor; Nürnberg, Jan-Hendrik

    2012-02-01

    Good status of pulmonary perfusion is essential for a successful outcome after the Fontan procedure. Increased pulmonary pressure and vascular resistance, small size of the pulmonary arteries, and significant branch stenoses reflect some of the main problems causing failing Fontan circulation. Here we report a child who underwent a staged Fontan procedure with subsequent subtotal loss of the left-sided pulmonary perfusion, although branch stenosis was successfully treated by stent implantation. Oral sildenafil caused restoration of the capillary vascular bed, improved left-sided lung perfusion, and resulted in significant clinical benefit.

  12. Evaluating acellular versus cellular perfusate composition during prolonged ex vivo lung perfusion after initial cold ischaemia for 24 hours.

    PubMed

    Becker, Simon; Steinmeyer, Jasmin; Avsar, Murat; Höffler, Klaus; Salman, Jawad; Haverich, Axel; Warnecke, Gregor; Ochs, Matthias; Schnapper, Anke

    2016-01-01

    Normothermic ex vivo lung perfusion (EVLP) has developed as a powerful technique to evaluate particularly marginal donor lungs prior to transplantation. In this study, acellular and cellular perfusate compositions were compared in an identical experimental setting as no consensus has been reached on a preferred technique yet. Porcine lungs underwent EVLP for 12 h on the basis of an acellular or a cellular perfusate composition after 24 h of cold ischaemia as defined organ stress. During perfusion, haemodynamic and respiratory parameters were monitored. After EVLP, the lung condition was assessed by light and transmission electron microscopy. Aerodynamic parameters did not show significant differences between groups and remained within the in vivo range during EVLP. Mean oxygenation indices were 491 ± 39 in the acellular group and 513 ± 53 in the cellular group. Groups only differed significantly in terms of higher pulmonary artery pressure and vascular resistance in the cellular group. Lung histology and ultrastructure were largely well preserved after prolonged EVLP and showed only minor structural alterations which were similarly present in both groups. Prolonged acellular and cellular EVLP for 12 h are both feasible with lungs prechallenged by ischaemic organ stress. Physiological and ultrastructural analysis showed no superiority of either acellular or cellular perfusate composition.

  13. Reversible cortical blindness: posterior reversible encephalopathy syndrome.

    PubMed

    Bandyopadhyay, Sabyasachi; Mondal, Kanchan Kumar; Das, Somnath; Gupta, Anindya; Biswas, Jaya; Bhattacharyya, Subir Kumar; Biswas, Gautam

    2010-11-01

    Cortical blindness is defined as visual failure with preserved pupillary reflexes in structurally intact eyes due to bilateral lesions affecting occipital cortex. Bilateral oedema and infarction of the posterior and middle cerebral arterial territory, trauma, glioma and meningioma of the occipital cortex are the main causes of cortical blindness. Posterior reversible encephalopathy syndrome (PRES) refers to the reversible subtype of cortical blindness and is usually associated with hypertension, diabetes, immunosuppression, puerperium with or without eclampsia. Here, 3 cases of PRES with complete or partial visual recovery following treatment in 6-month follow-up are reported.

  14. Dipyridamole perfusion scintigraphy: The experience with its application in one hundred seventy patients with known or suspected unstable angina

    SciTech Connect

    Zhu, Y.Y.; Chung, W.S.; Botvinick, E.H.; Dae, M.W.; Lim, A.D.; Ports, T.A.; Danforth, J.W.; Wolfe, C.L.; Goldschlager, N.; Chatterjee, K. )

    1991-01-01

    We evaluated the safety, accuracy, and potential clinical utility of intravenous dipyridamole perfusion scintigraphy with thallium-201 in 170 patients, 78 with suspected and 92 with known unstable angina. All had coronary angiography. Noncardiac side effects (26%), induced chest discomfort (44%), and ST segment changes (12%) were similar in the two groups. No significant arrhythmias occurred. Two patients had prolonged chest pain, both with extensive reversible image abnormalities and associated creatinine kinase-MB release. Both had elective bypass surgery. Twenty-eight patients had normal coronary arteries, and 35 had single-vessel disease. Scintigraphic per patient sensitivity and specificity were 91% and 79% with a per vessel sensitivity of 74% and a per vessel specificity of 78% without between-group differences. During a brief follow-up period, 62 patients with image abnormalities had coronary revascularization, and there were seven deaths without intergroup differences. In a similar patient group that did not have angiography, scintigraphic defects were less frequent and less extensive, revascularization was not performed, and subsequent deaths occurred less often. Dipyridamole perfusion scintigraphy is an accurate alternative to exercise testing in the evaluation of patients with unstable angina pectoris. Although not without risk, the method appears relatively safe and should be considered as a guide to diagnosis, and probably to prognosis and management.

  15. Anatomical consideration of reverse-flow island flap transfers from the midpalm for finger reconstruction.

    PubMed

    Omokawa, S; Tanaka, Y; Ryu, J; Clovis, N

    2001-12-01

    Primary soft-tissue coverage for large palmar defects of the fingers is a difficult problem for cases in which homodigital or heterodigital flaps cannot be used. The aim of this study was to explore the vascular and neural anatomy of the midpalmar area to assess the possibility of reverse island flaps from this area. In 24 cadaver hands perfused with a silicone compound, the arterial pattern of the superficial palmar arch and common palmar digital artery was examined. The cutaneous perforating arteries and nerve branches supplying the midpalmar area were dissected, and the number, location, and arterial diameter of these branches were measured. In six other specimens, the common palmar digital artery was injected to determine the skin territory supplied by the artery. The superficial palmar arch contained the three common palmar digital arteries and its terminal branch coursed along the radial margin of the index metacarpus. This terminal branch had three to six cutaneous perforators (diameter range, 0.1 to 0.5 mm) and supplied the radial aspect of the midpalmar area located over the ulnar half of the adductor pollicis muscles. The midpalmar area was divided into two regions-the proximal and distal-according to the vascular distributions. The proximal region contained dense aponeurosis and thin subcutaneous tissue, and the cutaneous perforators were rather sparse (between three and nine) and had a small diameter (0.1 to 0.3 mm). The distal region, which had loose aponeurosis and abundant subcutaneous tissue, had a rich vascular supply from the common and proper digital artery. Perforating arteries of this region coursed frequently in an oblique fashion and the number of perforators (between eight and 15) and their arterial diameters (diameter range, 0.1 to 0.5 mm) were higher than those of the proximal region. The area of skin perfused by the common palmar digital artery was 5 x 3 cm at the distal midpalmar region. There were three to five cutaneous nerve branches

  16. Delayed redistribution in thallium 201 SPECT myocardial perfusion studies

    SciTech Connect

    Ziessman, H.A.; Keyes, J.W. Jr.; Fox, L.M.; Green, C.E.; Fox, S.M. )

    1989-11-01

    Stress {sup 201}Tl myocardial perfusion studies are useful in differentiating viable, reversibly ischemic from infarcted myocardium. A perfusion defect that shows redistribution 2 to 4 h after {sup 201}Tl injection is diagnostic of ischemia, while a fixed defect suggests infarction. However, occasional patients with a fixed defect at 4 h have redistribution at 24 h. This study evaluates the frequency and significance of this delayed redistribution with SPECT {sup 201}Tl. Patients with either no or incomplete redistribution at 4 h had repeat imaging 18 to 48 h later. Delayed redistribution was seen in 8/26 (31 percent). Four had incomplete and four had no redistribution at 4 h. Delayed redistribution with SPECT {sup 201}Tl is more common than generally appreciated, and we recommend delayed images in patients with fixed perfusion defects or incomplete redistribution at 4-h imaging, particularly in patients with previous infarctions for whom a revascularization procedure is being considered.

  17. Arterial insufficiency

    MedlinePlus

    ... the most common causes of arterial insufficiency is atherosclerosis or "hardening of the arteries." Fatty material (called ... Images Arteries of the brain Developmental process of atherosclerosis References Hansson GK, Hamsten A. Atherosclerosis, thrombosis, and ...

  18. Evaluation of Perfusion Quantification Methods with Ultrasound Contrast Agents in a Machine-Perfused Pig Liver.

    PubMed

    Averkiou, M; Keravnou, C P; Izamis, M L; Leen, E

    2016-05-03

    Purpose: To evaluate dynamic contrast-enhanced ultrasound (DCEUS) as a tool for measuring blood flow in the macro- and microcirculation of an ex-vivo machine-perfused pig liver and to confirm the ability of DCEUS to accurately detect induced flow rate changes so that it could then be used clinically for monitoring flow changes in liver tumors. Materials and Methods: Bolus injections of contrast agents in the hepatic artery (HA) and portal vein (PV) were administered to 3 machine-perfused pig livers. Flow changes were induced by the pump of the machine perfusion system. The induced flow rates were of clinical relevance (150 - 400 ml/min for HA and 400 - 1400 ml/min for PV). Quantification parameters from time-intensity curves [rise time (RT), mean transit time (MTT), area under the curve (AUC) and peak intensity (PI)] were extracted in order to evaluate whether the induced flow changes were reflected in these parameters. Results: A linear relationship between the image intensity and the microbubble concentration was confirmed first, while time parameters (RT and MMT) were found to be independent of concentration. The induced flow changes which propagated from the larger vessels to the parenchyma were reflected in the quantification parameters. Specifically, RT, MTT and AUC correlated with flow rate changes. Conclusion Machine-perfused pig liver is an excellent test bed for DCEUS quantification approaches for the study of the hepatic vascular networks. DCEUS quantification parameters (RT, MTT, and AUC) can measure relative flow changes of about 20 % and above in the liver vasculature. DCEUS quantification is a promising tool for real-time monitoring of the vascular network of tumors.

  19. The pediatric template of brain perfusion

    PubMed Central

    Avants, Brian B; Duda, Jeffrey T; Kilroy, Emily; Krasileva, Kate; Jann, Kay; Kandel, Benjamin T; Tustison, Nicholas J; Yan, Lirong; Jog, Mayank; Smith, Robert; Wang, Yi; Dapretto, Mirella; Wang, Danny J J

    2015-01-01

    Magnetic resonance imaging (MRI) captures the dynamics of brain development with multiple modalities that quantify both structure and function. These measurements may yield valuable insights into the neural patterns that mark healthy maturation or that identify early risk for psychiatric disorder. The Pediatric Template of Brain Perfusion (PTBP) is a free and public neuroimaging resource that will help accelerate the understanding of childhood brain development as seen through the lens of multiple modality neuroimaging and in relation to cognitive and environmental factors. The PTBP uses cross-sectional and longitudinal MRI to quantify cortex, white matter, resting state functional connectivity and brain perfusion, as measured by Arterial Spin Labeling (ASL), in 120 children 7–18 years of age. We describe the PTBP and show, as a demonstration of validity, that global summary measurements capture the trajectories that demarcate critical turning points in brain maturation. This novel resource will allow a more detailed understanding of the network-level, structural and functional landmarks that are obtained during normal adolescent brain development. PMID:25977810

  20. The pediatric template of brain perfusion.

    PubMed

    Avants, Brian B; Duda, Jeffrey T; Kilroy, Emily; Krasileva, Kate; Jann, Kay; Kandel, Benjamin T; Tustison, Nicholas J; Yan, Lirong; Jog, Mayank; Smith, Robert; Wang, Yi; Dapretto, Mirella; Wang, Danny J J

    2015-01-01

    Magnetic resonance imaging (MRI) captures the dynamics of brain development with multiple modalities that quantify both structure and function. These measurements may yield valuable insights into the neural patterns that mark healthy maturation or that identify early risk for psychiatric disorder. The Pediatric Template of Brain Perfusion (PTBP) is a free and public neuroimaging resource that will help accelerate the understanding of childhood brain development as seen through the lens of multiple modality neuroimaging and in relation to cognitive and environmental factors. The PTBP uses cross-sectional and longitudinal MRI to quantify cortex, white matter, resting state functional connectivity and brain perfusion, as measured by Arterial Spin Labeling (ASL), in 120 children 7-18 years of age. We describe the PTBP and show, as a demonstration of validity, that global summary measurements capture the trajectories that demarcate critical turning points in brain maturation. This novel resource will allow a more detailed understanding of the network-level, structural and functional landmarks that are obtained during normal adolescent brain development.

  1. Accuracy and precision of pseudo-continuous arterial spin labeling perfusion during baseline and hypercapnia: a head-to-head comparison with ¹⁵O H₂O positron emission tomography.

    PubMed

    Heijtel, D F R; Mutsaerts, H J M M; Bakker, E; Schober, P; Stevens, M F; Petersen, E T; van Berckel, B N M; Majoie, C B L M; Booij, J; van Osch, M J P; Vanbavel, E; Boellaard, R; Lammertsma, A A; Nederveen, A J

    2014-05-15

    Measurements of the cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) provide useful information about cerebrovascular condition and regional metabolism. Pseudo-continuous arterial spin labeling (pCASL) is a promising non-invasive MRI technique to quantitatively measure the CBF, whereas additional hypercapnic pCASL measurements are currently showing great promise to quantitatively assess the CVR. However, the introduction of pCASL at a larger scale awaits further evaluation of the exact accuracy and precision compared to the gold standard. (15)O H₂O positron emission tomography (PET) is currently regarded as the most accurate and precise method to quantitatively measure both CBF and CVR, though it is one of the more invasive methods as well. In this study we therefore assessed the accuracy and precision of quantitative pCASL-based CBF and CVR measurements by performing a head-to-head comparison with (15)O H₂O PET, based on quantitative CBF measurements during baseline and hypercapnia. We demonstrate that pCASL CBF imaging is accurate during both baseline and hypercapnia with respect to (15)O H₂O PET with a comparable precision. These results pave the way for quantitative usage of pCASL MRI in both clinical and research settings.

  2. The adverse effects of reduced cerebral perfusion on cognition and brain structure in older adults with cardiovascular disease

    PubMed Central

    Alosco, Michael L; Gunstad, John; Jerskey, Beth A; Xu, Xiaomeng; Clark, Uraina S; Hassenstab, Jason; Cote, Denise M; Walsh, Edward G; Labbe, Donald R; Hoge, Richard; Cohen, Ronald A; Sweet, Lawrence H

    2013-01-01

    Background It is well established that aging and vascular processes interact to disrupt cerebral hemodynamics in older adults. However, the independent effects of cerebral perfusion on neurocognitive function among older adults remain poorly understood. We examined the associations among cerebral perfusion, cognitive function, and brain structure in older adults with varying degrees of vascular disease using perfusion magnetic resonance imaging (MRI) arterial spin labeling (ASL). Materials and methods 52 older adults underwent neuroimaging and were administered the Mini Mental State Examination (MMSE), the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and measures of attention/executive function. ASL and T1-weighted MRI were used to quantify total brain perfusion, total brain volume (TBV), and cortical thickness. Results Regression analyses showed reduced total brain perfusion was associated with poorer performance on the MMSE, RBANS total index, immediate and delayed memory composites, and Trail Making Test B. Reduced frontal lobe perfusion was associated with worse executive and memory function. A similar pattern emerged between temporal lobe perfusion and immediate memory. Regression analyses revealed that decreased total brain perfusion was associated with smaller TBV and mean cortical thickness. Regional effects of reduced total cerebral perfusion were found on temporal and parietal lobe volumes and frontal and temporal cortical thickness. Discussion Reduced cerebral perfusion is independently associated with poorer cognition, smaller TBV, and reduced cortical thickness in older adults. Conclusion Prospective studies are needed to clarify patterns of cognitive decline and brain atrophy associated with cerebral hypoperfusion. PMID:24363966

  3. Ex vivo lung perfusion

    PubMed Central

    Machuca, Tiago N.

    2014-01-01

    Lung transplantation (LTx) is an established treatment option for eligible patients with end-stage lung disease. Nevertheless, the imbalance between suitable donor lungs available and the increasing number of patients considered for LTx reflects in considerable waitlist mortality. Among potential alternatives to address this issue, ex vivo lung perfusion (EVLP) has emerged as a modern preservation technique that allows for more accurate lung assessment and also improvement of lung function. Its application in high-risk donor lungs has been successful and resulted in safe expansion of the donor pool. This article will: (I) review the technical details of EVLP; (II) the rationale behind the method; (III) report the worldwide clinical experience with the EVLP, including the Toronto technique and others; (IV) finally, discuss the growing literature on EVLP application for donation after cardiac death (DCD) lungs. PMID:25132972

  4. Atrial pacing and thallium 201 scintigraphy: combined use for diagnosis of coronary artery disease

    SciTech Connect

    Stratmann, H.G.; Mark, A.L.; Walter, K.E.; Fletcher, J.W.; Williams, G.A.

    1987-11-01

    To evaluate the presence of coronary artery disease (CAD), atrial pacing and thallium 201 scintigraphy were performed in 36 patients with stable angina pectoris who were unable to perform an adequate exercise stress test. All patients underwent cardiac catheterization. Nine patients had previously undergone coronary artery bypass surgery. Significant CAD (one or more lesions greater than or equal to 50%) was present in 33 patients. Atrial pacing produced ischemic ST segment depression (greater than or equal to 1 mm) in 18 (55%) patients with CAD, and angina in 20 patients (61%). As the number of vessels with CAD increased, there was no significant change in the sensitivities of pacing-induced angina or ST segment depression for detecting CAD. In the 3 patients without CAD, ST segment depression occurred in 1 patient and angina in none. Thallium 201 scintigraphy demonstrated perfusion defects in 27 (82%) patients with CAD, with fixed defects seen in 13 studies (39%) and reversible defects in 15 (45%). In the 3 patients without CAD, no perfusion defects were seen. The thallium 201 scan successfully predicted the presence of CAD in patients with single-vessel disease but usually underestimated the number of vessels involved in patients with multivessel disease. Combined sensitivity of pacing-induced ST segment depression and an abnormal thallium 201 scan finding for detecting CAD was 91%. The authors conclude that combined atrial pacing and thallium 201 scintigraphy is a useful test for detecting CAD in patients unable to perform an adequate exercise stress test.

  5. Assessment of the intrapulmonary ventilation-perfusion distribution after the Fontan procedure for complex cardiac anomalies: Relation to pulmonary hemodynamics

    SciTech Connect

    Matsushita, T.; Matsuda, H.; Ogawa, M.; Ohno, K.; Sano, T.; Nakano, S.; Shimazaki, Y.; Nakahara, K.; Arisawa, J.; Kozuka, T. )

    1990-03-15

    In 12 patients who underwent the Fontan procedure for complex cardiac anomalies, lung scanning with xenon-133 was performed to assess the intrapulmonary ventilation-perfusion distribution, and comparison was made with a control group. All data were then analyzed in relation to either pre- or postoperative pulmonary hemodynamic data. In ventilation scans, the intrapulmonary distribution in the right lung was almost normal. In perfusion scans, an abnormal increased upper to lower lobe perfusion ratio greater than the normal value found in the control group was noted in seven patients (58.3%). There was a significant correlation (p less than 0.02) between the upper to lower lobe perfusion ratio and postoperative pulmonary vascular resistance. Furthermore, this perfusion ratio correlated inversely with the preoperative (p less than 0.005) and postoperative (p less than 0.02) right pulmonary artery area index, defined as the ratio of cross-sectional area to the normal value. Of five patients with less than 90% arterial oxygen saturation, four showed an abnormal distribution of pulmonary blood flow greater than the normal perfusion ratio. No patient had evidence of a pulmonary arteriovenous fistula by the echocardiographic contrast study. These results suggest that abnormal distribution of pulmonary blood flow to the upper lung segment may develop in patients after the Fontan procedure, and that insufficient size of the pulmonary artery before operation and the consequent postoperative elevation of pulmonary vascular resistance may be responsible for this perfusion abnormality.

  6. Cerebral-Body Perfusion Model

    DTIC Science & Technology

    1990-07-01

    compared to the 0.5g curve) fall in flow. Fig. 9b, showing the 5g case, strongly suggests a possible, so-called, " luxury perfusion ", in which natural...as the luxury perfusion situation which bypasses the flow with the nutrients it carries (through newly opened collaterals) and result in a "blackout...89-0054 CEREBRAL-BODY PERFUSION MODEL S. Sorek’, J. Bear2, and M., Feinsod3 in Collaboration with K. Allen4, L. Bunt5 and S. Ben-IHaiM6 July 1990

  7. A method to quantify and visualize femoral head intraosseous arteries by micro-CT.

    PubMed

    Qiu, Xing; Shi, Xiaotian; Ouyang, Jun; Xu, Dachuan; Zhao, Dewei

    2016-08-01

    We describe a technique for perfusing a barium sulphate suspension into the intraosseous artery. Following the perfusion of abarium sulphate suspension into 14 fresh lower limbs of Chinese cadavers, micro-CT scanning was applied to digitize, quantify and visualize the intraosseous arteries in the human femoral heads. Then, the femoral heads were removed and subjected to micro-CT scanning. The data were imported into the amira and mimics programs to reconstruct and quantify the intraosseous arteries. The femoral head intraosseous artery lengths, areas, volumes, and femoral head bone volumes were quantified. The artery densities and artery ratios were calculated and analysed with independent-samples t-tests. The intraosseous vasculature volume renderings were displayed as screenshots and videos made with amira. Many intraosseous artery study technologies were compared. The barium sulphate suspension was milky white in colour. The perfusion of the barium sulphate suspension followed by micro-CT scanning provided a good representation of the intraosseous artery. The femoral head intraosseous artery lengths, areas and volumes, and the femoral head bone volumes were displayed as the X¯±S . No differences were observed between the left and right femoral head intraosseous arteries in terms of the artery densities or artery ratios. The volume renderings and 3-D orthogonal projections displayed the overall distributions of the intraosseous arteries. The videos clearly demonstrated the entry sites of the nutrition-carrying arteries, their courses and branches, and the intraosseous arterial anastomoses. Our technique is the simplest and least time-consuming method of producing accurate vascular three-dimensional reconstructions. The perfusion of a barium sulphate suspension into intraosseous arteries combined with micro-CT scanning can deliver high-resolution 3-D digitized data and images of intraosseous arteries. This technique does not require bone decalcification or bone

  8. Anomalous Origin of the Left Coronary Artery From the Pulmonary Artery

    PubMed Central

    Gangadharan, Venkat; Sivagnanam, Kamesh; Murtaza, Ghulam; Ponders, Michael; Teixeira, Otto; Paul, Timir

    2017-01-01

    A 36-year-old woman was seen with complaints of exertional chest pain and shortness of breath. Her medical history included atrial fibrillation and diabetes. Physical examination was unremarkable except for an irregular cardiac rhythm. Myocardial perfusion imaging revealed the presence of a large area of infarction involving the entire anterior and apical walls and part of the anteroseptal wall with minimal periinfarct ischemia. Computed tomography coronary angiogram revealed an anomalous left main coronary artery arising from the main pulmonary artery. Right and left heart catheterizations demonstrated moderate pulmonary hypertension with a slight step-up in oxygen saturation between the right ventricle and main pulmonary artery. Coronary angiography showed a large tortuous right coronary artery with collaterals to the left anterior descending artery that drained into the main pulmonary artery. She was referred for surgery. This case demonstrates a rare coronary artery anomaly in an adult where survival is dependent on collateral circulation. PMID:28210637

  9. Viability of the vascularly perfused, recirculating rat intestine and intestine-liver preparations

    SciTech Connect

    Hirayama, H.; Xu, X.; Pang, K.S. )

    1989-08-01

    Function and stability of vascularly perfused, recirculating in situ rat intestine (I) and intestine-liver (IL) preparations were evaluated in fasted and nonfasted rats because these techniques may be readily applied in drug metabolism studies. The rat intestine was perfused with blood medium (7.5 ml/min) via the superior mesenteric artery, with the venous outflow draining into the portal vein, which, together with hepatic arterial flow (2.5 ml/min), constituted the total blood flow (10 ml/min) to the liver. Maintenance of intestinal membrane integrity was observed. Rapid ({sup 14}C)glucose absorption against a concentration gradient and a lack of ({sup 3}H)-polyethylene glycol 4000 (PEG 4000, less than 4%) and Evans blue absorption by the recirculating I and IL preparations resulted after bolus injections of these markers into the pyloric end of the duodenum. Other indexes that revealed stable intestinal and liver functions were the following: preservation of reservoir perfusate volume, constancy in perfusion pressure, bile flow, and hemoglobin concentrations, evidence of intestinal glucose utilization and liver glucose production, and a lack of significant leakage of serum glutamic oxalic transaminase. The intestine and liver consumed oxygen at relatively constant rates, but the consumption rates for the fasted tissues (I or L) were significantly higher than those for nonfasted tissues. These results indicate that the vascularly perfused I and IL preparations were maintained in a viable and stable state for a 2-h perfusion period.

  10. Blue laser light increases perfusion of a skin flap via release of nitric oxide from hemoglobin.

    PubMed

    Mittermayr, Rainer; Osipov, Anatoly; Piskernik, Christina; Haindl, Susanne; Dungel, Peter; Weber, Carina; Vladimirov, Yuri A; Redl, Heinz; Kozlov, Andrey V

    2007-01-01

    It has recently been shown that nitrosyl complexes of hemoglobin (NO-Hb) are sensitive to low-level blue laser irradiation, suggesting that laser irradiation can facilitate the release of biologically active nitric oxide (NO), which can affect tissue perfusion. The aim of this study was to evaluate the therapeutic value of blue laser irradiation for local tissue perfusion after surgical intervention. Blood was withdrawn from a rat, exposed to NO and infused back to the same rat or used for in vitro experiments. In vitro, an increase of NO-Hb levels (electron paramagnetic resonance spectroscopy) up to 15 microM in rat blood did not result in the release of detectable amounts of NO (NO selective electrode). Blue laser irradiation of NO-Hb in blood caused decomposition of NO-Hb complexes and release of free NO. Systemic infusion of NO-Hb in rats affected neither systemic circulation (mean arterial pressure) nor local tissue perfusion (Doppler blood flow imaging system). In contrast, a clear enhancement of local tissue perfusion was observed in epigastric flap when elevated NO-Hb levels in blood were combined with local He-Cd laser irradiation focused on the left epigastric artery. The enhancement of regional tissue perfusion was not accompanied by any detectable changes in systemic circulation. This study demonstrates that blue laser irradiation improves local tissue perfusion in a controlled manner stimulating NO release from NO-Hb complexes.

  11. Myocardial perfusion scintigraphy: the evidence

    PubMed Central

    Anagnostopoulos, C.; Cerqueira, M.; Ell, P. J.; Flint, E. J.; Harbinson, M.; Kelion, A. D.; Al-Mohammad, A.; Prvulovich, E. M.; Shaw, L. J.; Tweddel, A. C.

    2003-01-01

    This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by

  12. Pulmonary ventilation/perfusion scan

    MedlinePlus

    ... JavaScript. A pulmonary ventilation/perfusion scan involves two nuclear scan tests to measure breathing (ventilation) and circulation ( ... In: Mettler FA, Guiberteau MJ, eds. Essentials of Nuclear Medicine Imaging . 6th ed. Philadelphia, PA: Elsevier Saunders; ...

  13. Modeling of nanotherapeutics delivery based on tumor perfusion

    NASA Astrophysics Data System (ADS)

    van de Ven, Anne L.; Abdollahi, Behnaz; Martinez, Carlos J.; Burey, Lacey A.; Landis, Melissa D.; Chang, Jenny C.; Ferrari, Mauro; Frieboes, Hermann B.

    2013-05-01

    Heterogeneities in the perfusion of solid tumors prevent optimal delivery of nanotherapeutics. Clinical imaging protocols for obtaining patient-specific data have proven difficult to implement. It is challenging to determine which perfusion features hold greater prognostic value and to relate measurements to vessel structure and function. With the advent of systemically administered nanotherapeutics whose delivery is dependent on overcoming diffusive and convective barriers to transport, such knowledge is increasingly important. We describe a framework for the automated evaluation of vascular perfusion curves measured at the single vessel level. Primary tumor fragments, collected from triple-negative breast cancer patients and grown as xenografts in mice, were injected with fluorescence contrast and monitored using intravital microscopy. The time to arterial peak and venous delay, two features whose probability distributions were measured directly from time-series curves, were analyzed using a fuzzy c-mean supervised classifier in order to rank individual tumors according to their perfusion characteristics. The resulting rankings correlated inversely with experimental nanoparticle accumulation measurements, enabling the modeling of nanotherapeutics delivery without requiring any underlying assumptions about tissue structure or function, or heterogeneities contained therein. With additional calibration, these methodologies may enable the investigation of nanotherapeutics delivery strategies in a variety of tumor models.

  14. Hypothermic Machine Perfusion Preservation of the DCD Kidney: Machine Effects.

    PubMed

    Lindell, Susanne L; Muir, Heather; Brassil, John; Mangino, Martin J

    2013-01-01

    Purpose. Kidneys from DCD donors represent a significant pool, but preservation problems exist. The study objective was to test the importance of machine type for hypothermic preservation of DCD kidneys. Methods. Adult Beagle dog kidneys underwent 45 minutes of warm in situ ischemia followed by hypothermic perfusion for 24 hours (Belzer-MPS Solution) on either an ORS LifePort or a Waters RM3 using standard perfusion protocols. Kidneys were then autotransplanted, and renal function was assessed over 7 days following contralateral nephrectomy. Results. Renal vascular resistance was not different between the two pumps. After 24 hours, the oxygen partial pressure and oxygen delivery in the LifePort perfusate were significantly lower than those in the RM3 but not low enough to change lactate production. TheLifePort ran significantly colder than RM3 (2° versus 5°C). The arterial pressure waveform of the RM3 was qualitatively different from the waveform of the LifePort. Preservation injury after transplantation was not different between the devices. When the LifePort was changed to nonpulsatile flow, kidneys displayed significantly greater preservation injury compared to RM3. Conclusions. Both LifePort and RM3 can be used for hypothermic machine perfusion preservation of DCD kidneys with equal outcomes as long as the duty cycle remains pulsatile.

  15. A study on cerebral hemodynamic analysis of moyamoya disease by using perfusion MRI

    NASA Astrophysics Data System (ADS)

    Dong, Kyung-Rae; Goo, Eun-Hoe; Lee, Jae-Seung; Chung, Woon-Kwan

    2013-10-01

    This study examined the clinical applications of perfusion magnetic resonance imaging (MRI) in patients with moyamoya disease (MMD). Twenty-two patients with moyamoya disease (9 men and 13 women) with a mean age of 9.3 years (range: 4-22 years) were enrolled in this study. Perfusion MRI was performed by scanning the patients7.5 cm upward from the base of the cerebellum before their being process for post-treatment. The scan led to the acquisition of the following four map images: the cerebral blood volume (CBV), the cerebral blood flow (CBF), the mean transit time (MTT) for the contrast medium, and the time to peak (TTP) for the contrast medium. The lesions were assessed using the CBV, the CBF, the MTT and the TTP maps of perfusion MRI; the MTT and the TTP were measured in the lesion areas, as well as in the normal and the symmetric areas. Perfusion defects were recognizable in all four perfusion MRI maps, and the MTT and the TTP showed a conspicuous delay in the parts where perfusion defects were recognized. The MTT and the TTP images of perfusion MRI reflected a significant correlation between the degrees of stenosis and occlusion in the posterior cerebral artery (PCA), as well as the development of collateral vessels. The four perfusion MRI maps could be used to predict the degrees of stenosis and occlusion in the posterior circulation, as well as the development of the collateral vessels, which enabled a hemodynamic evaluation of the parts with perfusion defects. Overall, perfusion MRI is useful for the diagnosis and the treatment of moyamoya disease and can be applied to clinical practice.

  16. A simple physiologic pulsatile perfusion system for the study of intact vascular tissue.

    PubMed

    Conklin, B S; Surowiec, S M; Lin, P H; Chen, C

    2000-07-01

    Perfusion vascular culture models may provide a useful link between cell culture models and animal culture models by allowing a high level of control over important parameters while maintaining physiologic structure. The purpose of this study was to develop and test a new vascular culture system for pulsatile perfusion culture of intact vascular tissue. The system generates a pulsatile component of flow by means of a cam-driven syringe and a peristaltic pump and compliance chamber. Cams were designed, constructed and tested to simulate canine femoral and common carotid artery flows. The mean pressure was adjusted between 60 and 200 mmHg without significantly affecting flow rate, flow waveform, or the pressure waveform. Porcine common carotid artery segments were cultured in this pulsatile perfusion system. The viability of vascular segments was tested after various culture times with a functional assay that demonstrated both smooth muscle cell and endothelial cell response to vasomotor challenge.

  17. Decreased Cerebral Blood Flow in Chronic Pediatric Mild TBI: An MRI Perfusion Study

    PubMed Central

    Wang, Yang; West, John D.; Bailey, Jessica N.; Westfall, Daniel R.; Xiao, Hui; Arnold, Todd W.; Kersey, Patrick A.; Saykin, Andrew J.; McDonald, Brenna C.

    2015-01-01

    We evaluated cerebral blood flow (CBF) in chronic pediatric mild traumatic brain injury (mTBI) using arterial spin labeling (ASL) magnetic resonance imaging perfusion. mTBI patients showed lower CBF than controls in bilateral frontotemporal regions, with no between-group cognitive differences. Findings suggest ASL may be useful to assess functional abnormalities in pediatric mTBI. PMID:25649779

  18. Localized Spatio-Temporal Constraints for Accelerated CMR Perfusion

    PubMed Central

    Akçakaya, Mehmet; Basha, Tamer A.; Pflugi, Silvio; Foppa, Murilo; Kissinger, Kraig V.; Hauser, Thomas H.; Nezafat, Reza

    2013-01-01

    Purpose To develop and evaluate an image reconstruction technique for cardiac MRI (CMR)perfusion that utilizes localized spatio-temporal constraints. Methods CMR perfusion plays an important role in detecting myocardial ischemia in patients with coronary artery disease. Breath-hold k-t based image acceleration techniques are typically used in CMR perfusion for superior spatial/temporal resolution, and improved coverage. In this study, we propose a novel compressed sensing based image reconstruction technique for CMR perfusion, with applicability to free-breathing examinations. This technique uses local spatio-temporal constraints by regularizing image patches across a small number of dynamics. The technique is compared to conventional dynamic-by-dynamic reconstruction, and sparsity regularization using a temporal principal-component (pc) basis, as well as zerofilled data in multi-slice 2D and 3D CMR perfusion. Qualitative image scores are used (1=poor, 4=excellent) to evaluate the technique in 3D perfusion in 10 patients and 5 healthy subjects. On 4 healthy subjects, the proposed technique was also compared to a breath-hold multi-slice 2D acquisition with parallel imaging in terms of signal intensity curves. Results The proposed technique results in images that are superior in terms of spatial and temporal blurring compared to the other techniques, even in free-breathing datasets. The image scores indicate a significant improvement compared to other techniques in 3D perfusion (2.8±0.5 vs. 2.3±0.5 for x-pc regularization, 1.7±0.5 for dynamic-by-dynamic, 1.1±0.2 for zerofilled). Signal intensity curves indicate similar dynamics of uptake between the proposed method with a 3D acquisition and the breath-hold multi-slice 2D acquisition with parallel imaging. Conclusion The proposed reconstruction utilizes sparsity regularization based on localized information in both spatial and temporal domains for highly-accelerated CMR perfusion with potential utility in free

  19. Ventilation-perfusion matching during exercise

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.

    1992-01-01

    In normal subjects, exercise widens the alveolar-arterial PO2 difference (P[A-a]O2) despite a more uniform topographic distribution of ventilation-perfusion (VA/Q) ratios. While part of the increase in P(A-a)O2 (especially during heavy exercise) is due to diffusion limitation, a considerable amount is caused by an increase in VA/Q mismatch as detected by the multiple inert gas elimination technique. Why this occurs is unknown, but circumstantial evidence suggests it may be related to interstitial pulmonary edema rather than to factors dependent on ventilation, airway gas mixing, airway muscle tone, or pulmonary vascular tone. In patients with lung disease, the gas exchange consequences of exercise are variable. Thus, arterial PO2 may increase, remain the same, or fall. In general, patients with advanced chronic obstructive pulmonary disease (COPD) or interstitial fibrosis who exercise show a fall in PO2. This is usually not due to worsening VA/Q relationships but mostly to the well-known fall in mixed venous PO2, which itself results from a relatively smaller increase in cardiac output than VO2. However, in interstitial fibrosis (but not COPD), there is good evidence that a part of the fall in PO2 on exercise is caused by alveolar-capillary diffusion limitation of O2 transport; in COPD (but not interstitial fibrosis), a frequent additional contributing factor to the hypoxemia of exercise is an inadequate ventilatory response, such that minute ventilation does not rise as much as does CO2 production or O2 uptake, causing arterial PCO2 to increase and PO2 to fall.

  20. Parkinson's disease-related perfusion and glucose metabolic brain patterns identified with PCASL-MRI and FDG-PET imaging

    PubMed Central

    Teune, Laura K.; Renken, Remco J.; de Jong, Bauke M.; Willemsen, Antoon T.; van Osch, Matthias J.; Roerdink, Jos B.T.M.; Dierckx, Rudi A.; Leenders, Klaus L.

    2014-01-01

    Introduction Under normal conditions, the spatial distribution of resting cerebral blood flow and cerebral metabolic rate of glucose are closely related. A relatively new magnetic resonance (MR) technique, pseudo-continuous arterial spin labeling (PCASL), can be used to measure regional brain perfusion. We identified a Parkinson's disease (PD)-related perfusion and metabolic covariance pattern in the same patients using PCASL and FDG-PET imaging and assessed (dis)similarities in the disease-related pattern between perfusion and metabolism in PD patients. Methods Nineteen PD patients and seventeen healthy controls underwent [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging. Of 14 PD patients and all healthy controls PCASL-MRI could be obtained. Data were analyzed using scaled subprofile model/principal component analysis (SSM/PCA). Results Unique Parkinson's disease-related perfusion and metabolic covariance patterns were identified using PCASL and FDG-PET in the same patients. The PD-related metabolic covariance brain pattern is in high accordance with previously reports. Also our disease-related perfusion pattern is comparable to the earlier described perfusion pattern. The most marked difference between our perfusion and metabolic patterns is the larger perfusion decrease in cortical regions including the insula. Conclusion We identified PD-related perfusion and metabolic brain patterns using PCASL and FDG-PET in the same patients which were comparable with results of existing research. In this respect, PCASL appears to be a promising addition in the early diagnosis of individual parkinsonian patients. PMID:25068113

  1. Cerebral perfusion alterations in epileptic patients during peri-ictal and post-ictal phase: PASL vs DSC-MRI.

    PubMed

    Pizzini, Francesca B; Farace, Paolo; Manganotti, Paolo; Zoccatelli, Giada; Bongiovanni, Luigi G; Golay, Xavier; Beltramello, Alberto; Osculati, Antonio; Bertini, Giuseppe; Fabene, Paolo F

    2013-07-01

    Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment.

  2. Canine Autoanticoagulation during Extracorporeal Perfusion.

    DTIC Science & Technology

    1979-12-19

    eviscerated as .o’: atr midline laparatomy, the celiac , superior and inerior ee ..: re ligated and divided between ligatures and the following x-azr C...extreme care taken to prevent loss of blood. In half of the experiments, the hepatic artery was maintained. patent by sectioning the celiac artery distal...to the origin of the hepatic artery; in the other half, the celiac artery was divided near its origin at the aorta, thus preventing flow via the

  3. Hypoxic vasodilatation in isolated, perfused guinea-pig heart: an analysis of the underlying mechanisms.

    PubMed Central

    von Beckerath, N; Cyrys, S; Dischner, A; Daut, J

    1991-01-01

    1. The mechanisms underlying hypoxic dilatation of coronary arteries were studied in isolated guinea-pig hearts perfused with physiological salt solution at 37 degrees C. The hearts were perfused at a constant rate of 3-10 ml min-1; coronary perfusion pressure (CPP) and isovolumetric left ventricular pressure (LVP) were measured with piezoresistive transducers. 2. Addition of the K+ channel opener cromakalim (500 nM) to the perfusate caused a maximal vasodilatation in beating hearts, i.e. a decrease in CPP of about 50%. Switching from normal perfusate (partial pressure of O2 (PO2), 650-700 mmHg) to hypoxic perfusate (PO2, 9-10 mmHg) caused a similar vasodilatation. Both of these effects were prevented by 2 microM-glibenclamide, a blocker of ATP-sensitive potassium channels. Hypoxic vasodilatation was accompanied by a marked decrease in LVP, which was reduced by 56 +/- 22% (mean +/- S.D.) in the presence of glibenclamide. 3. In hearts arrested by increasing the K+ concentration of the perfusate to 15 mM, the addition of the adenosine-uptake inhibitor dipyridamole evoked a maximal vasodilatation and this was inhibited by 76 +/- 7% in the presence of glibenclamide. 4. The adenosine antagonist 8-phenyltheophylline (8-PT; 5 microM) inhibited the vasodilatation induced by dipyridamole by 88 +/- 10%. In contrast, hypoxic vasodilatation was unaffected by 5 microM 8-PT. This suggests that hypoxic dilatation of coronary arteries is not mediated by release of adenosine from cardiomyocytes. 5. In order to test whether release of endothelium-derived relaxing factor (EDRF) contributed to hypoxic vasodilatation we blocked EDRF synthesis with N omega-nitro-L-arginine (NNA). When applied at a perfusion rate of 10 ml min-1 to arrested hearts, 10 microM-NNA increased CPP by 35% and prolonged the delay between application of hypoxic solution and half-maximal vasodilatation from 52 +/- 9 to 129 +/- 29 s. 6. Under control conditions the relation between perfusion rate and the CPP

  4. PET imaging of cerebral perfusion and oxygen consumption in acute ischemic stroke: Relation to outcome

    SciTech Connect

    Marchal, G.; Serrati, C.; Rioux, P.; Petit-Taboue, M.C.; Viader, F.; Sayette, V. de la; Doze, F. le; Lonchon, P; Derlon, J.M.; Orgogozo, J.M.; Baron, J.C.

    1993-04-10

    The authors used positron emission tomography (PET) to assess the relation between combined imaging of cerebral blood flow and oxygen consumption 5-18 h after first middle cerebral artery (MCA) stroke and neurological outcome at 2 months. All 18 patients could be classified into three visually defined PET patterns of perfusion and oxygen consumption changes. Pattern 1 suggested extensive irreversible damage and was consistently associated with poor outcome. Pattern 2 suggested continuing ischemia and was associated with variable outcome. Pattern 3 with hyperperfusion and little or no metabolic alteration, was associated with excellent recovery, which suggests that early reperfusion is beneficial. This relation between PET and outcome was highly significant. The results suggest that within 5-18 h of stroke onset, PET is a good predictor of outcome in patterns 1 and 3, for which therapy seems limited. The absence of predictive value for pattern 2 suggests that it is due to a reversible ischemic state that is possibly amenable to therapy. These findings may have important implications for acute MCA stroke management and for patients' selection for therapeutic trials.

  5. Scaling of cerebral blood perfusion in primates and marsupials.

    PubMed

    Seymour, Roger S; Angove, Sophie E; Snelling, Edward P; Cassey, Phillip

    2015-08-01

    The evolution of primates involved increasing body size, brain size and presumably cognitive ability. Cognition is related to neural activity, metabolic rate and rate of blood flow to the cerebral cortex. These parameters are difficult to quantify in living animals. This study shows that it is possible to determine the rate of cortical brain perfusion from the size of the internal carotid artery foramina in skulls of certain mammals, including haplorrhine primates and diprotodont marsupials. We quantify combined blood flow rate in both internal carotid arteries as a proxy of brain metabolism in 34 species of haplorrhine primates (0.116-145 kg body mass) and compare it to the same analysis for 19 species of diprotodont marsupials (0.014-46 kg). Brain volume is related to body mass by essentially the same exponent of 0.70 in both groups. Flow rate increases with haplorrhine brain volume to the 0.95 power, which is significantly higher than the exponent (0.75) expected for most organs according to 'Kleiber's Law'. By comparison, the exponent is 0.73 in marsupials. Thus, the brain perfusion rate increases with body size and brain size much faster in primates than in marsupials. The trajectory of cerebral perfusion in primates is set by the phylogenetically older groups (New and Old World monkeys, lesser apes) and the phylogenetically younger groups (great apes, including humans) fall near the line, with the highest perfusion. This may be associated with disproportionate increases in cortical surface area and mental capacity in the highly social, larger primates.

  6. Resting cardiointegram: correlation with stress thallium perfusion studies

    SciTech Connect

    Gould, L.A.; Betzu, R.; Judge, D.; Lee, J.; Taddeo, M.; Yang, D.

    1988-04-01

    The cardiointegram is a noninvasive technique for the analysis of the electrical signals of the heart obtained by a transformation of the voltage versus time format by a series of integrations. The stress thallium perfusion study is a widely used test for the detection of coronary artery disease. In order to evaluate the correlation between the resting cardiointegram and the stress thallium 201 perfusion study, 20 patients with normal resting electrocardiograms underwent stress thallium tests and resting cardiointegrams. The cardiointegram was determined on two resting complexes of leads I, II, V4, V5, and V6 and called abnormal if five of ten complexes deviated outside a normalized template. There was concordance of the cardiointegram and the thallium study in 16 of 20 patients (80%). The sensitivity for the detection of coronary artery disease was 71%, and the specificity was 80%. The overall accuracy was 74%. Thus in patients with normal electrocardiograms, the cardiointegram is a useful noninvasive test for the detection of coronary artery disease.

  7. The Effect of Hemodynamic Remodeling on the Survival of Arterialized Venous Flaps

    PubMed Central

    Yan, Hede; Kolkin, Jon; Zhao, Bin; Li, Zhefeng; Jiang, Shichao; Wang, Wei; Xia, Zhen; Fan, Cunyi

    2013-01-01

    Objective To evaluate the effect of hemodynamic remodeling on the survival status of the arterialized venous flaps (AVFs) and investigate the mechanism of this procedure. Materials and Methods Two 7 x 9 cm skin flaps in each rabbit (n=36) were designed symmetrically in the abdomen. The thoracoepigastric pedicle and one femoral artery were used as vascular sources. Four groups were included: Composite skin grafts group and arterial perfusion group were designed in one rabbit; AVF group and hemodynamic remodeling group by ligation of the thoracoepigastric vein in the middle were outlined in another rabbit. Flap viability, status of vascular perfusion and microvasculature, levels of epidermal metabolite and water content in each group were assessed. Results Highly congested veins and simple trunk veins were found using angiography in the AVF group; while a fairly uniform staining and plenty of small vessels were observed in the hemodynamic remodeling group. The metabolite levels of the remodeling group are comparable with those in the arterial perfusion group. There was no statistically significant difference in the percentage of flap survival between the arterial perfusion group and hemodynamic remodeling group; however, significant difference was seen between the AVF group and the hemodynamic remodeling group. Conclusions Under the integrated perfusion mode, the AVFs are in an over-perfusion and non-physiological hemodynamic state, resulting in unreliability and unpredictability in flap survival; under the separated perfusion mode produced by remodeling, a physiological-like circulation will be created and therefore, better flap survival can be expected. PMID:24265782

  8. Arterial Catheterization

    MedlinePlus

    ... The arterial catheter allows accurate, second-to-second measurement of the blood pressure; repeated meas- urement is ... pressure must be lowered gradually in steps, and measurements with an arterial catheter help guide the treatment. ■ ...

  9. Reversal of abnormal cardiac parameters following mitral valve replacement for severe mitral stenosis in relation to pulmonary artery pressure: A retrospective study of noninvasive parameters – Early and late pattern

    PubMed Central

    Parvathy, Usha T.; Rajan, Rajesh; Faybushevich, Alexander Georgevich

    2016-01-01

    Background and objectives Although the regression of pulmonary hypertension (PH) in mitral stenosis (MS) has been studied over varying periods postintervention, corresponding studies on the cardiac chamber alterations after surgery are very limited. We sought to determine the degree of reversal of these and the clinical status in connection with that of pulmonary artery pressures (PAPs) in the early and late postoperative periods. Methods The preoperative, early, and 1-year postoperative data – functional class (FC), cardiothoracic ratio (CTR) in chest X-ray (CXR), and echocardiographically left atrium (LA), right atrium (RA), right ventricle (RV), left ventricle (LV), and pulmonary artery (PA) dimensions, PAP, tricuspid regurgitation (TR) – of 50 patients who had mitral valve replacement (MVR) for MS with PH were retrospectively analyzed for correlations with PAP (Pearson’s), and their change (t-test), in relation to that in PAP. PH group-based [Group (Gp)-I PAP ≤60 mmHg, Gp-II PAP >60 mmHg] analysis highlighted the differences. Results All parameters significantly correlated with the baseline PAP (p < 0.05), except LA (r = 0.081, p = 0.577). Postoperatively, there was significant reduction in all parameters (p < 0.001) and increase in LV (p < 0.003). The PAP regression was 39.42%; with the decrease in CTR, LA, and RA related to it, the early changes being significant (p < 0.01). The RV and PA showed lesser reduction (8.61% and 9.42%), late reduction being more conspicuous. The changes were greater and significant in Gp-II (especially PAP, RV, and PA). At 1 year, PAP normalized in only 19 (38%). Residual PH and chamber enlargement prevailed more in Gp-II. Conclusions This study emphasizes the importance of the baseline PAP in MS to which was proportionate the functional disability and the cardiac chamber alterations (except LA). Their postoperative improvement accompanying the PAP regression differed in degree and time frame

  10. Comprehensive cardiac assessment with multislice computed tomography: evaluation of left ventricular function and perfusion in addition to coronary anatomy in patients with previous myocardial infarction

    PubMed Central

    Henneman, M M; Schuijf, J D; Jukema, J W; Lamb, H J; de Roos, A; Dibbets, P; Stokkel, M P; van der Wall, E E; Bax, J J

    2006-01-01

    Objective To evaluate a comprehensive multislice computed tomography (MSCT) protocol in patients with previous infarction, including assessment of coronary artery stenoses, left ventricular (LV) function and perfusion. Patients and methods 16‐slice MSCT was performed in 21 patients with previous infarction; from the MSCT data, coronary artery stenoses, (regional and global) LV function and perfusion were assessed. Invasive coronary angiography and gated single‐photon emission computed tomography (SPECT) served as the reference standards for coronary artery stenoses and LV function/perfusion, respectively. Results 236 of 241 (98%) coronary artery segments were interpretable on MSCT. The sensitivity and specificity for detection of stenoses were 91% and 97%. Pearson's correlation showed excellent agreement for assessment of LV ejection fraction between MSCT and SPECT (49 (13)% v 53 (12)%, respectively, r  =  0.85). Agreement for assessment of regional wall motion was excellent (92%, κ  =  0.77). In 68 of 73 (93%) segments, MSCT correctly identified a perfusion defect as compared with SPECT, whereas the absence of perfusion defects was correctly detected in 277 of 284 (98%) segments. Conclusions MSCT permits accurate, non‐invasive assessment of coronary artery stenoses, LV function and perfusion in patients with previous infarction. All parameters can be assessed from a single dataset. PMID:16740917

  11. [Ageing of the arterial wall].

    PubMed

    Hanon, O

    2006-11-01

    Several mechanisms are implicated in the arterial wall changes due to ageing: ageing, hypertension and atherosclerosis. Although the changes related to ageing (arteriosclerosis) have many factors in common with those induced by hypertension, they differ from those caused by atherosclerosis although commonly associated. Arteriosclerosis causes a diffuse increase of the rigidity of the large arteries by disease of the media, the main clinical manifestation of which is the increase in pulsed pressure. This arterial "hyperpulsability" contributes to a defect in coupling between the heart and the blood vessels which results in an increase in the pulsatile load of the left ventricle and to left ventricular hypertrophy and decreased coronary perfusion. Atherosclerosis seems more of a localised scarring phenomenon of the arterial wall which is exposed to a series of chronic aggressions characterised by deposits of lipids in the intima and whose main complication is thrombosis. Although these two processes may be associated, or interact one with the other, they are clearly different in nature. Therefore, atherosclerosis is a localised disease resulting in a decrease in arterial lumen, quite different from arteriosclerosis which is a diffuse, physiological condition which leads to an increase in the arterial lumen.

  12. Continuous Intra-Arterial Nimodipine for the Treatment of Cerebral Vasospasm

    SciTech Connect

    Mayer, Thomas E.; Dichgans, Martin; Straube, Andreas; Birnbaum, Tobias; Mueller-Schunk, Stephanie; Hamann, Gerhard F.; Schulte-Altedorneburg, Gernot

    2008-11-15

    Two patients with refractory symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) were treated by continuous intra-arterial nimodipine infusion via a catheter placed in the internal carotid artery or vertebral artery for 3 and 12 days, respectively. Recovery of the neurological deficits, normalization of MR perfusion, a decrease in the elevated mean flow velocity measured by transcranial duplex sonography, and angiographic recanalization were observed. Continuous intra-arterial nimodipine might be a treatment option in severe refractory vasospasm following SAH.

  13. [Clinical applications of arterial spin labeling technique in brain diseases].

    PubMed

    Wang, Li; Zheng, Gang; Zhao, Tiezhu; Guo, Chao; Li, Lin; Lu, Guangming

    2013-02-01

    Arterial spin labeling (ASL) technique is a kind of perfusion functional magnetic resonance imaging method that is based on endogenous contrast, and it can measure cerebral blood flow (CBF) noninvasively. The ASL technique has advantages of noninvasiveness, simplicity and relatively lower costs so that it is more suitable for longitudinal studies compared with previous perfusion methods, such as positron emission tomography (PET), single photon emission computed tomography (SPECT), CT and the contrast agent based magnetic resonance perfusion imaging. This paper mainly discusses the current clinical applications of ASL in brain diseases as cerebrovascular diseases, brain tumors, Alzheimer's disease and epilepsy, etc.

  14. Viable neurons with luxury perfusion in hydrocephalus.

    PubMed

    Wong, C Y; Luciano, M G; MacIntyre, W J; Brunken, R C; Hahn, J F; Go, R T

    1997-09-01

    A woman with hydrocephalus due to aqueductal stenosis had functional imaging of cerebral perfusion and metabolism to demonstrate the effects of endoscopic third ventriculostomy--a new form of internal surgical shunting. Technetium-99m-ECD SPECT and 18F-FDG PET showed regional luxury perfusion at the left frontal region. Three months after a successful third ventriculostomy, a repeated imaging of cerebral perfusion and metabolism showed resolution of luxury perfusion and global improvement of both perfusion and metabolism. This concurred with postoperative clinical improvement. The paired imaging of cerebral perfusion and metabolism provides more information than just imaging perfusion or metabolism. Thus, the detection of perfusion and metabolism mismatch may open a new window of opportunity for surgical intervention.

  15. Exercise-induced coronary arterial spasm: angiographic demonstration, documentation of ischemia by myocardial scintigraphy and results of pharmacologic intervention.

    PubMed

    Fuller, C M; Raizner, A E; Chahine, R A; Nahormek, P; Ishimori, T; Verani, M; Nitishin, A; Mokotoff, D; Luchi, R J

    1980-09-01

    Exercise-induced coronary arterial spasm is an infrequently recognized phemonemon whose mechanism and management are not well established. In two patients with reproducible exercise-induced S-T segment elevation and angina pectoris thallium-201 scintigraphy showed areas of reversible anteroapical hypoperfusion, and gated radionuclide ventriculography revealed anteroapical hypokinesia with a decrease in left ventricular ejection fraction at peak exercise. During coronary arteriography supine exercise provoked occlusive spasm of the left anterior descending coronary artery, which at rest had only minimal plaques. Consequently, treadmill testing was performed with five different pharmacologically provoked interventions: direct vasodilatation (nitrates), alpha adrenergic blockade (phenmoxybenzamine), beta adrenergic blockade (propranolol), calcium flux blockade (verapamil), and prostaglandin inhibition (indomethacin). Exercise-induced coronary arterial spasm, manifested as S-T segment elevation and angina, was prevented by nitrates, but was not eliminated by short-term oral administration of an alpha or beta blocking agent, a calcium antagonist or a prostaglandin inhibitor. Further, beta adrenergic blockade appeared to be detrimental. Thus, this study demonstrates (1) that coronary arterial spasm may be the underlying mechanism of at least some cases of exertional angina associated with transient perfusion deficits and left ventricular dysfunction, and (2) that it may be prevented by oral nitrates.

  16. Perforator-to-perforator musculocutaneous anterolateral thigh flap for reconstruction of a lumbosacral defect using the lumbar artery perforator as recipient vessel.

    PubMed

    Mureau, Marc A M; Hofer, Stefan O P

    2008-05-01

    Reconstruction of large-sized lumbosacral or sacral defects often is not possible using local or regional flaps, making the use of free flaps necessary. However, the difficulty of any microsurgical procedure in this region is complicated by the need to search for potential recipient vessels to revascularize the flap. In the present case, a free musculocutaneous anterolateral thigh flap to cover a large-sized and deep lumbosacral defect was used. Arterial anastomosis was performed, connecting the cutaneous anterolateral thigh (ALT) perforator to the perforator of the second lumbar artery. In this fashion, the arterial circulation through the flap was flowing reversely through the muscle. The concomitant vein of the descending branch of the lateral circumflex femoral artery was hooked up to the thoracodorsal vein using a long interposition vein graft because the perforator of the second lumbar vein was too small. Postoperative healing was uneventful. In conclusion, a successful reconstruction of a lumbar defect has shown that local perforators in the lumbar area may be accessible for easier perforator-to-perforator anastomoses and that the muscular part of the musculocutaneous ALT flap can survive on retrograde arterial perfusion from a perforator of the skin island.

  17. Polydimethylsiloxane embedded mouse aorta ex vivo perfusion model: proof-of-concept study focusing on atherosclerosis

    NASA Astrophysics Data System (ADS)

    Wang, Xueya; Wolf, Marc P.; Keel, Rahel Bänziger; Lehner, Roman; Hunziker, Patrick R.

    2012-07-01

    Existing mouse artery ex vivo perfusion models have utilized arteries such as carotid, uterine, and mesenteric arteries, but not the aorta. However, the aorta is the principal vessel analyzed for atherosclerosis studies in vivo. We have devised a mouse aorta ex vivo perfusion model that can bridge this gap. Aortas from apoE(-/-) mice are embedded in a transparent, gas-permeable, and elastic polymer matrix [polydimethylsiloxane (PDMS)] and artificially perfused with cell culture medium under cell culture conditions. After 24 h of artificial ex vivo perfusion, no evidence of cellular apoptosis is detected. Utilizing a standard confocal microscope, it is possible to image specific receptor targeting of cells in atherosclerotic plaques during 24 h. Imaging motion artifacts are minimal due to the polymer matrix embedding. Re-embedding of the aorta enables tissue sectioning and immuno-histochemical analysis. The ex vivo data are validated by comparison with in vivo experiments. This model can save animal lives via production of multiple endpoints in a single experiment, is easy to apply, and enables straightforward comparability with pre-existing atherosclerosis in vivo data. It is suited to investigate atherosclerotic disease in particular and vascular biology in general.

  18. The effect of perfusion flow on oxidative metabolism during cardiopulmonary bypass.

    PubMed

    Baraka, A

    1993-06-01

    The influence of perfusion flow rate on whole-body oxygen consumption (VO2), central venous hemoglobin oxygen saturation (SVO2), and central venous arterial oxygen tension (PVO2) during hypothermic hemodilutional nonpulsatile cardiopulmonary bypass was investigated in 20 patients undergoing coronary artery bypass grafting. In 10 patients, the perfusion flow was 2.4 L.min-1 x m-2 (Group I), whereas a flow of 1.2 L.min-1 x m-2 was used in the other 10 patients (Group II). When the body temperature was 29.7 +/- 1.2 degrees C (Group I) and 29.6 +/- 0.8 degrees C (Group II), mixed venous and arterial blood were sampled simultaneously, and whole-body oxygen consumption was calculated. Data collected during hypothermia were compared with the corresponding values achieved after rewarming to 37 degrees C. In both groups, the whole-body oxygen consumption during hypothermia was lower by about 45% than the VO2 after rewarming. However, SVO2 during the low perfusion flow was not significantly different from SVO2 after rewarming, whereas the temperature-corrected PVO2 was significantly lower. In contrast, the high-perfusion flow provided luxury perfusion as evident by the high SVO2, and maintained the temperature-corrected PVO2 within the normothermic range. Thus, maintenance of the normothermic perfusion flow rate during moderate hypothermic hemodilutional cardiopulmonary bypass may provide a safety margin that may compensate for unexpected increase of oxygen consumption or decrease of oxygen delivery.

  19. Significance of inferior wall ischemia in non-dominant right coronary artery anatomy

    PubMed Central

    Malik, Ali Osama; Abela, Oliver; Devabhaktuni, Subodh; Malik, Arhama Aftab; Allenback, Gayle; Ahsan, Chowdhury H; Malhotra, Sanjay; Diep, Jimmy

    2017-01-01

    AIM To investigate the relationship of inferior wall ischemia on myocardial perfusion imaging in patients with non-dominant right coronary artery anatomy. METHODS This was a retrospective observational analysis of consecutive patients who presented to the emergency department with primary complaint of chest pain. Only patients who underwent single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) were included. Patients who showed a reversible defect on SPECT MPI and had coronary angiography during the same hospitalization was analyzed. Patients with prior history of coronary artery disease (CAD) including history of percutaneous coronary intervention and coronary artery bypass graft surgerys were excluded. True positive and false positive results were identified on the basis of hemodynamically significant CAD on coronary angiography, in the same territory as identified on SPECT MPI. Coronary artery dominance was determined on coronary angiography. Patients were divided into group 1 and group 2. Group 1 included patients with non-dominant right coronary artery (RCA) (left dominant and codominant). Group 2 included patients with dominant RCA anatomy. Demographics, baseline characteristics and positive predictive value (PPV) were analyzed for the two groups. RESULTS The mean age of the study cohort was 57.6 years. Sixty-one point seven percent of the patients were males. The prevalence of self-reported diabetes mellitus, hypertension and dyslipidemia was 36%, 71.9% and 53.9% respectively. A comparison of baseline characteristics between the two groups showed that patients with a non-dominant RCA were more likely to be men. For inferior wall ischemia on SPECT MPI, patients in study group 2 had a significantly higher PPV, 32/42 (76.1%), compared to patients in group 1, in which only 3 out of the 29 patients (10.3%) had true positive results (P value < 0.001 Z test). The difference remained statistically significant even when only patients

  20. Natural course of treated pulmonary embolism. Evaluation by perfusion lung scintigraphy, gas exchange, and chest roentgenogram.

    PubMed

    Prediletto, R; Paoletti, P; Fornai, E; Perissinotto, A; Petruzzelli, S; Formichi, B; Ruschi, S; Palla, A; Giannella-Neto, A; Giuntini, C

    1990-03-01

    Perfusion lung scintigrams, pulmonary gas exchange data, and chest roentgenograms were obtained in 33 patients during acute embolism and over the following six months in order to assess their clinical usefulness in monitoring the effect of therapy. To this purpose, the measurement of pulmonary gas exchange and the presence of chest x-ray findings were compared with perfusion lung scintigraphic abnormalities both at diagnosis and after 7, 30, and 180 days during treatment. More than 50 percent of the pulmonary arterial tree was obstructed at diagnosis, and a large part of perfusion recovery was complete within the first month. All of the gas exchange parameters were abnormal at diagnosis, and the rate of their improvement was related to that of perfusion recovery. Interestingly, PaO2st (ie, PaO2 corrected for hyperventilation) and VE tended to return to normal during the first month as a consequence of the progressive recovery of perfusion, whereas oxygen and carbon dioxide gradients and physiologic dead space showed the persistence of some abnormalities six months after diagnosis. Significant correlations were observed between the number of ULSs evaluated on the perfusion lung scintigram (and considered an index of the severity of pulmonary embolization) and all of the gas exchange parameters at diagnosis (correlation coefficients averaged from 0.41 to 0.73) and after 7 and 30 days. The enlargement of the right descending pulmonary artery and particularly the "sausage" sign and the Westermark sign were significantly associated with a higher degree of gas exchange impairment and with a more severe embolization. In conclusion, this study demonstrates that perfusion lung scintigraphy has a primary role in monitoring the recovery of patients with pulmonary embolism under treatment. Moreover, the chest roentgenogram may help in this purpose. A second major result is that the simple measurement of some gas exchange parameters may allow the assessment of functional

  1. 320-row CT renal perfusion imaging in patients with aortic dissection: A preliminary study

    PubMed Central

    Liu, Dongting; Liu, Jiayi; Wen, Zhaoying; Li, Yu; Sun, Zhonghua; Xu, Qin; Fan, Zhanming

    2017-01-01

    Objective To investigate the clinical value of renal perfusion imaging in patients with aortic dissection (AD) using 320-row computed tomography (CT), and to determine the relationship between renal CT perfusion imaging and various factors of aortic dissection. Methods Forty-three patients with AD who underwent 320-row CT renal perfusion before operation were prospectively enrolled in this study. Diagnosis of AD was confirmed by transthoracic echocardiography. Blood flow (BF) of bilateral renal perfusion was measured and analyzed. CT perfusion imaging signs of AD in relation to the type of AD, number of entry tears and the false lumen thrombus were observed and compared. Results The BF values of patients with type A AD were significantly lower than those of patients with type B AD (P = 0.004). No significant difference was found in the BF between different numbers of intimal tears (P = 0.288), but BF values were significantly higher in cases with a false lumen without thrombus and renal arteries arising from the true lumen than in those with thrombus (P = 0.036). The BF values measured between the true lumen, false lumen and overriding groups were different (P = 0.02), with the true lumen group having the highest. Also, the difference in BF values between true lumen and false lumen groups was statistically significant (P = 0.016), while no statistical significance was found in the other two groups (P > 0.05). The larger the size of intimal entry tears, the greater the BF values (P = 0.044). Conclusions This study shows a direct correlation between renal CT perfusion changes and AD, with the size, number of intimal tears, different types of AD, different renal artery origins and false lumen thrombosis, significantly affecting the perfusion values. PMID:28182709

  2. Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials

    NASA Astrophysics Data System (ADS)

    Jeronimo, Mark David

    Soft material tubes are critical in the vasculature of mammalian tissues, forming networks of blood vessels and airways. Homogeneous and heterogeneous hydrogel tubes were extruded in a one-step process using a three layer microfluidic device. Co-axial cylindrical flow of crosslinking solutions and an alginate matrix is generated by a radial arrangement of microfluidic channels at the device's vertical extrusion outlet. The flow is confined and begins a sol-gel transition immediately as it extrudes at velocities upwards of 4 mm/s. This approach allows for predictive control over the dimensions of the rapidly formed tubular structures for outer diameters from 600 microm to 3 mm. A second microfluidic device hosts tube segments for controlled perfusion and pressurization using a reversible vacuum seal. On-chip tube deflection is observed and modeled as a measure of material compliance and circumferential elasticity. I anticipate applications of these devices for perfusion cell culture of cell-laden hydrogel tubes.

  3. Exercise thallium-201 myocardial imaging in left main coronary artery disease: sensitive but not specific

    SciTech Connect

    Rehn, T.; Griffith, L.S.; Achuff, S.C.; Bailey, I.K.; Bulkley, B.H.; Burow, R.; Pitt, B.; Becker, L.C.

    1981-08-01

    To determine the usefulness of thallium-201 scintigraphy for identifying left main coronary artery disease, the results of scintigraphy at rest and during exercise were compared in 24 patients with 50 percent or greater narrowing of the left main coronary artery and 80 patients with 50 percent or greater narrowing of one or more of the major coronary arteries but without left main coronary involvement. By segmental analysis of the scintigrams, perfusion defects were assigned to the left anterior descending, left circumflex or right coronary artery, singly or in combination, and the pattern of simultaneous left anterior descending and circumflex arterial defects was used to identify left main coronary artery disease. Of the 24 patients with left main coronary artery disease, 22 (92 percent) had abnormal exercise scintigrams. Despite this high sensitivity, the pattern of perfusion defects was not specific; the ''left main pattern'' was found in 3 patients (13 percent) with left main coronary artery disease but also in 3 (33 percent) of 9 patients with combined left anterior descending and left circumflex arterial disease, 4 (19 percent) of 21 patients with three vessel disease and 3 (6 percent) of 50 patients with one or two vessel disease but excluding the group with left anterior descending plus left circumflex arterial disease. The pattern of perfusion defects in the patients with left main coronary artery disease was determined by the location and severity of narrowings in the coronary arteries downstream from the left main arterial lesion. Concomitant lesions in other arteries were found in all patients with left main coronary disease (one vessel in 1 patient, two vessels in 7 patients and three vessels in 16). For this reason, it is unlikely that even with improvements in radiopharmaceutical agents and imaging techniques, myocardial perfusion scintigraphy will be sufficiently specific for definitive identification of left main coronary artery disease.

  4. [Dissecting aneurysms at the bases of the brachiocephalic artery and the left common carotid artery due to localized dissection of the aortic arch; report of a case].

    PubMed

    Higashi, Shigeki; Yoshida, Y; Mitsuoka, H

    2007-07-01

    A 43-year-old male lost consciousness immediately after archery practice, and was brought to our hospital by ambulance. Angiography showed dissecting aneurysms at the bases of the brachiocephalic artery and the left common carotid artery, causing compression of these arteries. Under cardiopulmonary bypass with selective cerebral perfusion, the blood supply to these arteries was restored with a bifurcated graft. Surgical specimen showed localized dissection of the aortic arch at the bifurcation to the brachiocephalic artery and the left common carotid artery, with the formation of dissecting aneurysms at the bases of both arteries. The aneurysms were filled with thrombi. In addition to these dissecting aneurysms, there were arterial dissections involving the brachiocephalic artery and the bilateral common carotid arteries. Histopathological examination of the vessel wall showed no evidence of atherosclerosis or vasculitis, and no abnormalities in the arrangement of elastic fibers.

  5. Acute arterial occlusion - kidney

    MedlinePlus

    Acute renal arterial thrombosis; Renal artery embolism; Acute renal artery occlusion; Embolism - renal artery ... kidneys need a good blood supply. The main artery to the kidney is called the renal artery. ...

  6. Perfusion Angiography of the Foot in Patients with Critical Limb Ischemia: Description of the Technique

    SciTech Connect

    Jens, Sjoerd Marquering, Henk A.; Koelemay, Mark J. W.; Reekers, Jim A.

    2015-02-15

    ObjectiveTo study the feasibility of 2D perfusion imaging in critical limb ischemia (CLI).Methods/ResultsPerfusion angiography is a new technology which was tested in 18 patients with CLI of the foot. A standardized protocol was used with a catheter placed at the mid-part of the popliteal artery, and a total of 9 cc of non-ionic iodinated contrast material was injected at a rate of 3 cc/sec. The technology is based on early cardiology research where iodinated contrast agents were used for imaging of cardiac perfusion. During the first pass of the contrast, there is a significant diffusion of the contrast agents into the interstitial space, particularly for non-ionic and low-molecular-weight compounds.DiscussionThe original angiography data can be used to make a time–density curve, which represents the actual perfusion of the foot in time. Angiographic perfusion imaging is a post-processing modality for which no extra contrast or radiation is needed. With this technique, it is possible to get more information about the perfusion status and microcirculation of the foot. This is a step toward functional imaging in CLI patients.

  7. PERFUSION FOR MYOCARDIAL REVASCULARIZATION WITHOUT AN ARTIFICIAL OXYGENATOR (New Method to Reduce Surgical Morbidity)

    PubMed Central

    De Moraes, Domingos Junqueira; Abilio, Fued Michel; Cunha, Marcos; Feitosa, Lionicio A.; Aragão, Esmeraldino; Cysne, Eumenes; Vieira, Roberto; Glavam, Haroldo C. C.; Zaniolo, Waldomiro; Netto, Mario Salles; Villela, Ronaldo De A.; Labrunie, Pierre

    1979-01-01

    Thirteen patients were submitted to direct myocardial revascularization (saphenous vein graft) without the use of an artificial oxygenator. The perfusion was done by a left ventricle-to-aorta bypass and autogenous oxygenation. Most patients had three grafts implanted plus endarterectomy of the distal right coronary artery. There was one hospital death that was apparently not related to the method used. Perfusion time ranged from 45 minutes to 4 hours. Body temperature during perfusion was kept between 25 and 30° C. Perfusion flow was maintained between 25 to 50 ml per kg of body weight per minute. Ischemic, hypothermic cardiac arrest was employed. We demonstrated for the first time that perfusion for this kind of heart surgery could be done with no artificial oxygenators and, apparently, is safer for the patients. There were no bleeding problems even in perfusions as long as 4 hours. There was no respiratory dysfunction, and artificial respiration was used for only 6 to 12 hours. The patients awoke at the end of surgery with no signs or symptoms of central nervous system damage, and vasopressor drugs were rarely used after surgery. Although the experience is very small, it suggests that many postoperative problems, especially those related to bleeding and respiratory dysfunction may be reduced or eliminated by this new method. PMID:15216319

  8. Perfusion Magnetic Resonance Imaging: A Comprehensive Update on Principles and Techniques

    PubMed Central

    Li, Ka-Loh; Ostergaard, Leif; Calamante, Fernando

    2014-01-01

    Perfusion is a fundamental biological function that refers to the delivery of oxygen and nutrients to tissue by means of blood flow. Perfusion MRI is sensitive to microvasculature and has been applied in a wide variety of clinical applications, including the classification of tumors, identification of stroke regions, and characterization of other diseases. Perfusion MRI techniques are classified with or without using an exogenous contrast agent. Bolus methods, with injections of a contrast agent, provide better sensitivity with higher spatial resolution, and are therefore more widely used in clinical applications. However, arterial spin-labeling methods provide a unique opportunity to measure cerebral blood flow without requiring an exogenous contrast agent and have better accuracy for quantification. Importantly, MRI-based perfusion measurements are minimally invasive overall, and do not use any radiation and radioisotopes. In this review, we describe the principles and techniques of perfusion MRI. This review summarizes comprehensive updated knowledge on the physical principles and techniques of perfusion MRI. PMID:25246817

  9. Myocardial perfusion echocardiography and coronary microvascular dysfunction

    PubMed Central

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-01-01

    Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking. PMID:26730291

  10. New Trends in Radionuclide Myocardial Perfusion Imaging

    PubMed Central

    Hung, Guang-Uei; Wang, Yuh-Feng; Su, Hung-Yi; Hsieh, Te-Chun; Ko, Chi-Lun; Yen, Ruoh-Fang

    2016-01-01

    Radionuclide myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) has been widely used clinically as one of the major functional imaging modalities for patients with coronary artery disease (CAD) for decades. Ample evidence has supported the use of MPI as a useful and important tool in the diagnosis, risk stratification and treatment planning for CAD. Although popular in the United States, MPI has become the most frequently used imaging modality among all nuclear medicine tests in Taiwan. However, it should be acknowledged that MPI SPECT does have its limitations. These include false-positive results due to certain artifacts, false-negative due to balanced ischemia, complexity and adverse reaction arising from current pharmacological stressors, time consuming nature of the imaging procedure, no blood flow quantitation and relatively high radiation exposure. The purpose of this article was to review the recent trends in nuclear cardiology, including the utilization of positron emission tomography (PET) for MPI, new stressor, new SPECT camera with higher resolution and higher sensitivity, dynamic SPECT protocol for blood flow quantitation, new software of phase analysis for evaluation of LV dyssynchrony, and measures utilized for reducing radiation exposure of MPI. PMID:27122946

  11. Molecular and Cellular Basis of Microvascular Perfusion Deficits Induced by Clostridium perfringens and Clostridium septicum

    PubMed Central

    Hickey, Michael J.; Kwan, Rain Y. Q.; Awad, Milena M.; Kennedy, Catherine L.; Young, Lauren F.; Hall, Pam; Cordner, Leanne M.; Lyras, Dena; Emmins, John J.; Rood, Julian I.

    2008-01-01

    Reduced tissue perfusion leading to tissue ischemia is a central component of the pathogenesis of myonecrosis caused by Clostridium perfringens. The C. perfringens α-toxin has been shown capable of inducing these changes, but its potential synergy with perfringolysin O (θ-toxin) is less well understood. Similarly, Clostridium septicum is a highly virulent causative agent of spontaneous gas gangrene, but its effect on the microcirculation has not been examined. Therefore, the aim of this study was to use intravital microscopy to examine the effects of C. perfringens and C. septicum on the functional microcirculation, coupled with the use of isogenic toxin mutants to elucidate the role of particular toxins in the resultant microvascular perfusion deficits. This study represents the first time this integrated approach has been used in the analysis of the pathological response to clostridial toxins. Culture supernatants from wild-type C. perfringens induced extensive cell death within 30 min, as assessed by in vivo uptake of propidium iodide. Furthermore, significant reductions in capillary perfusion were observed within 60 min. Depletion of either platelets or neutrophils reduced the alteration in perfusion, consistent with a role for these blood-borne cells in obstructing perfusion. In addition, mutation of either the α-toxin or perfringolysin O structural genes attenuated the reduction in perfusion, a process that was reversed by genetic complementation. C. septicum also induced a marked reduction in perfusion, with the degree of microvascular compromise correlating with the level of the C. septicum α-toxin. Together, these data indicate that as a result of its ability to produce α-toxin and perfringolysin O, C. perfringens rapidly induces irreversible cellular injury and a marked reduction in microvascular perfusion. Since C. septicum induces a similar reduction in microvascular perfusion, it is postulated that this function is central to the pathogenesis of

  12. Does machine perfusion decrease ischemia reperfusion injury?

    PubMed

    Bon, D; Delpech, P-O; Chatauret, N; Hauet, T; Badet, L; Barrou, B

    2014-06-01

    In 1990's, use of machine perfusion for organ preservation has been abandoned because of improvement of preservation solutions, efficient without perfusion, easy to use and cheaper. Since the last 15 years, a renewed interest for machine perfusion emerged based on studies performed on preclinical model and seems to make consensus in case of expanded criteria donors or deceased after cardiac death donations. We present relevant studies highlighted the efficiency of preservation with hypothermic machine perfusion compared to static cold storage. Machines for organ preservation being in constant evolution, we also summarized recent developments included direct oxygenation of the perfusat. Machine perfusion technology also enables organ reconditioning during the last hours of preservation through a short period of perfusion on hypothermia, subnormothermia or normothermia. We present significant or low advantages for machine perfusion against ischemia reperfusion injuries regarding at least one primary parameter: risk of DFG, organ function or graft survival.

  13. Effect of combined VEGF165/ SDF-1 gene therapy on vascular remodeling and blood perfusion in cerebral ischemia.

    PubMed

    Hu, Guo-Jie; Feng, Yu-Gong; Lu, Wen-Peng; Li, Huan-Ting; Xie, Hong-Wei; Li, Shi-Fang

    2016-12-16

    OBJECTIVE Therapeutic neovascularization is a promising strategy for treating patients after an ischemic stroke; however, single-factor therapy has limitations. Stromal cell-derived factor 1 (SDF-1) and vascular endothelial growth factor (VEGF) proteins synergistically promote angiogenesis. In this study, the authors assessed the effect of combined gene therapy with VEGF165 and SDF-1 in a rat model of cerebral infarction. METHODS An adenoviral vector expressing VEGF165 and SDF-1 connected via an internal ribosome entry site was constructed (Ad- VEGF165-SDF-1). A rat model of middle cerebral artery occlusion (MCAO) was established; either Ad- VEGF165-SDF-1 or control adenovirus Ad- LacZ was stereotactically microinjected into the lateral ventricle of 80 rats 24 hours after MCAO. Coexpression and distribution of VEGF165 and SDF-1 were examined by reverse-transcription polymerase chain reaction, Western blotting, and immunofluorescence. The neurological severity score of each rat was measured on Days 3, 7, 14, 21, and 28 after MCAO. Angiogenesis and vascular remodeling were evaluated via bromodeoxyuridine and CD34 immunofluorescence labeling. Relative cerebral infarction volumes were determined by T2-weighted MRI and triphenyltetrazolium chloride staining. Cerebral blood flow, relative cerebral blood volume, and relative mean transmit time were assessed using perfusion-weighted MRI. RESULTS The Ad- VEGF165-SDF-1 vector mediated coexpression of VEGF165 and SDF-1 in multiple sites around the ischemic core, including the cortex, corpus striatum, and hippocampal granular layer. Coexpression of VEGF165 and SDF-1 improved neural function, reduced cerebral infarction volume, increased microvascular density and promoted angiogenesis in the ischemic penumbra, and improved cerebral blood flow and perfusion. CONCLUSIONS Combined VEGF165 and SDF-1 gene therapy represents a potential strategy for improving vascular remodeling and recovery of neural function after cerebral

  14. Myocardial perfusion abnormalities in patients with hypertrophic cardiomyopathy: assessment with thallium-201 emission computed tomography

    SciTech Connect

    O'Gara, P.T.; Bonow, R.O.; Maron, B.J.; Damske, B.A.; Van Lingen, A.; Bacharach, S.L.; Larson, S.M.; Epstein, S.E.

    1987-12-01

    Myocardial ischemia may play a critical role in the symptomatic presentation and natural history of hypertrophic cardiomyopathy (HCM). To assess the relative prevalence and functional significance of myocardial perfusion abnormalities in patients comprising the broad clinical spectrum of HCM, we studied 72 patients (ages 12 to 69 years, mean 40) using thallium-201 emission computed tomography. Imaging was performed immediately after maximal exercise and again after a 3 hr delay. Regional perfusion defects were identified in 41 of the 72 patients (57%). Fixed or only partially reversible defects were evident in 17 patients, 14 of whom (82%) had left ventricular ejection fractions of less than 50% at rest. Twenty-four patients demonstrated perfusion defects during exercise that completely reversed at rest; all had normal or hyperdynamic left ventricular systolic function (ejection fraction greater than or equal to 50%). Perfusion abnormalities were present in all regions of the left ventricle. However, the fixed defects were observed predominantly in segments of the left ventricular wall that were of normal or only mildly increased (15 to 20 mm) thickness; in contrast, a substantial proportion (41%) of the completely reversible defects occurred in areas of moderate-to-marked wall thickness (greater than or equal to 20 mm, p less than .001). Neither a history of chest pain nor its provocation with treadmill exercise was predictive of an abnormal thallium study, since regional perfusion defects were present in 10 of 18 (56%) completely asymptomatic patients, compared with 31 of 54 (58%) symptomatic patients. These data indicate that myocardial perfusion abnormalities occur commonly among patients with HCM. Fixed or only partially reversible defects suggestive of myocardial scar and/or severe ischemia occur primarily in patients with impaired systolic performance.

  15. Verapamil prevents silent myocardial perfusion abnormalities during exercise in asymptomatic patients with hypertrophic cardiomyopathy

    SciTech Connect

    Udelson, J.E.; Bonow, R.O.; O'Gara, P.T.; Maron, B.J.; Van Lingen, A.; Bacharach, S.L.; Epstein, S.E.

    1989-05-01

    Recent studies indicate that reversible 201Tl perfusion defects, compatible with silent myocardial ischemia, commonly develop during exercise in asymptomatic or mildly symptomatic patients with hypertrophic cardiomyopathy (HCM). To determine whether this represents a dynamic process that may be modified favorably by medical therapy, we studied 29 asymptomatic or minimally symptomatic patients with HCM, aged 12-55 years (mean, 28), with exercise 201Tl emission computed tomography under control conditions and again after 1 week of oral verapamil (mean dosage, 453 mg/day). Treadmill time increased slightly during verapamil (21.0 +/- 3.6 to 21.9 +/- 2.7 minutes, p less than 0.005), but peak heart rate-blood pressure product was unchanged (26.3 +/- 6.0 X 10(3)) compared with 25.0 +/- 6.4 X 10(3). Two midventricular short-axis images per study were divided into five regions each, and each of these 10 regions was then analyzed on a 0-2 scale by three observers blinded with regard to the patients' therapy. Average regional scores of 1.5 or less were considered to represent perfusion defects, and a change in regional score of 0.5 or more was considered to constitute a significant change. During control studies, 15 patients (52%) developed perfusion defects with exercise (average, 3.7 regions per patient). In 14 of these patients, all perfusion defects completely reversed after 3 hours of rest; one patient had fixed defects. After administration of verapamil, exercise perfusion scores improved in 10 of the 14 patients (71%) with reversible defects; there was overall improvement in 34 of 50 (68%) regions with initially reversible perfusion defects.

  16. Effect of isolated proximal coronary stenotic lesions on distal myocardial perfusion during exercise

    SciTech Connect

    Nichols, A.B.; Buczek, J.A.; Schwann, T.A.; Esser, P.D.; Blood, D.K.

    1988-07-01

    This study tested the hypothesis that the absolute dimension of a coronary stenotic lesion is a more important determinant of its hemodynamic effect on regional myocardial perfusion during exercise than is relative percent stenosis. In 31 patients with an isolated lesion of the left anterior descending coronary artery, regional myocardial perfusion was determined from thallium-201 scans recorded in the left anterior oblique projection after symptom-limited treadmill exercise. Thallium-201 uptake in the distribution of the left anterior descending coronary artery was expressed as a ratio of thallium-201 uptake in the left circumflex artery distribution. Percent area stenosis, minimal cross-sectional area and mean diameter of each stenotic lesion were measured by computer-assisted cinevideodensitometric analysis of projected coronary arteriograms digitized in a 512 X 512 pixel matrix with 256 gray levels. Thallium-201 uptake in the left anterior descending coronary artery distribution, expressed as a ratio, correlated poorly (r = 0.65) with relative percent stenosis, but correlated significantly (r = 0.83; p less than 0.05) with absolute lesion area. For all 16 patients with reduced regional perfusion in the left anterior descending coronary artery distribution during exercise, lesion cross-sectional area was less than 1.8 mm2 (mean 0.9 +/- 0.6); for 13 of the 15 patients with normal distal perfusion, the area of the stenotic lesion was greater than 1.8 mm2 (mean 2.7 +/- 0.7; p less than 0.001). Percent coronary stenosis failed to predict flow-limiting lesions.

  17. Criteria for viability assessment of discarded human donor livers during ex vivo normothermic machine perfusion.

    PubMed

    Sutton, Michael E; op den Dries, Sanna; Karimian, Negin; Weeder, Pepijn D; de Boer, Marieke T; Wiersema-Buist, Janneke; Gouw, Annette S H; Leuvenink, Henri G D; Lisman, Ton; Porte, Robert J

    2014-01-01

    Although normothermic machine perfusion of donor livers may allow assessment of graft viability prior to transplantation, there are currently no data on what would be a good parameter of graft viability. To determine whether bile production is a suitable biomarker that can be used to discriminate viable from non-viable livers we have studied functional performance as well as biochemical and histological evidence of hepatobiliary injury during ex vivo normothermic machine perfusion of human donor livers. After a median duration of cold storage of 6.5 h, twelve extended criteria human donor livers that were declined for transplantation were ex vivo perfused for 6 h at 37 °C with an oxygenated solution based on red blood cells and plasma, using pressure controlled pulsatile perfusion of the hepatic artery and continuous portal perfusion. During perfusion, two patterns of bile flow were identified: (1) steadily increasing bile production, resulting in a cumulative output of ≥ 30 g after 6 h (high bile output group), and (2) a cumulative bile production <20 g in 6 h (low bile output group). Concentrations of transaminases and potassium in the perfusion fluid were significantly higher in the low bile output group, compared to the high bile output group. Biliary concentrations of bilirubin and bicarbonate were respectively 4 times and 2 times higher in the high bile output group. Livers in the low bile output group displayed more signs of hepatic necrosis and venous congestion, compared to the high bile output group. In conclusion, bile production could be an easily assessable biomarker of hepatic viability during ex vivo machine perfusion of human donor livers. It could potentially be used to identify extended criteria livers that are suitable for transplantation. These ex vivo findings need to be confirmed in a transplant experiment or a clinical trial.

  18. Association of frontal gray matter volume and cerebral perfusion in heroin addiction: a multimodal neuroimaging study.

    PubMed

    Denier, Niklaus; Schmidt, André; Gerber, Hana; Schmid, Otto; Riecher-Rössler, Anita; Wiesbeck, Gerhard A; Huber, Christian G; Lang, Undine E; Radue, Ernst-Wilhelm; Walter, Marc; Borgwardt, Stefan

    2013-01-01

    Structure and function are closely related in the healthy human brain. In patients with chronic heroin exposure, brain imaging studies have identified long-lasting changes in gray matter (GM) volume. More recently, we showed that acute application of heroin in dependent patients results in hypoperfusion of fronto-temporal areas compared with the placebo condition. However, the relationship between structural and cerebral blood flow (CBF) changes in heroin addiction has not yet been investigated. Moreover, it is not known whether there is any interaction between the chronic structural changes and the short and long-term effects on perfusion caused by heroin. Using a double-blind, within-subject design, heroin or placebo (saline) was administered to 14 heroin-dependent patients from a stable heroin-assisted treatment program, in order to observe acute short-term effects. Arterial spin labeling (ASL) was used to calculate perfusion quantification maps in both treatment conditions, while Voxel-Based Morphometry (VBM) was conducted to calculate regional GM density. VBM and ASL data were used to calculate homologous correlation fields by Biological Parametric Mapping (BPM) and a whole-brain Pearson r correlation. We correlated each perfusion condition (heroin and placebo) separately with a VBM sample that was identical for the two treatment conditions. It was assumed that heroin-associated perfusion is manifested in short-term effects, while placebo-associated perfusion is more related to long-term effects. In order to restrict our analyses to fronto-temporal regions, we used an explicit mask for our analyses. Correlation analyses revealed a significant positive correlation in frontal areas between GM and both perfusion conditions (heroin and placebo). Heroin-associated perfusion was also negatively correlated with GM in the inferior temporal gyrus on both hemispheres. These findings indicate that, in heroin-dependent patients, low GM volume is positively associated with

  19. [Diagnosing venous and venous/arterial ulcers].

    PubMed

    Perceau, Géraldine

    2012-01-01

    A venous ulcer can be diagnosed on the basis of elements arising from the questioning and the clinical examination of the patient. A venous Doppler ultrasound can specify the type of reverse flow (superficial and/or deep). Measuring the ankle brachial pressure index helps to eliminate or confirm any arterial involvement. Depending on the systolic pressure index, the ulcer will be considered as purely venous, mixed (arterial-venous) or predominantly arterial.

  20. Brachioradial arteries with anastomotic arteries connecting to brachial arteries bilaterally.

    PubMed

    Hong, Tong; Qiuhong, Dan; Haipeng, Cai

    2010-01-01

    We present a patient with a failed radial coronary angioplasty as a result of bilateral brachioradial arteries, the radial arteries anomalously originating from the axillary arteries. We review the literature concerning abnormal origins of the radial artery and propose the left ulnar artery as optimal access of choice in cases with a right brachioradial artery of relatively small size in its proximal part.

  1. Diastolic time fraction as a determinant of subendocardial perfusion.

    PubMed

    Fokkema, Dirk S; VanTeeffelen, Jurgen W G E; Dekker, Simone; Vergroesen, Isabelle; Reitsma, Johannes B; Spaan, Jos A E

    2005-05-01

    Diastolic time fraction (DTF) has been recognized as an important determinant for subendocardial perfusion, but microsphere studies in which DTF was the independent variable are practically absent. In 21 anesthetized goats, the left coronary main stem was artificially perfused at controlled pressure. DTF was varied by pacing the heart, vagus stimulation, or administration of dobutamine. Regional coronary flow was measured with fluorescent microspheres under full adenosine dilation. Perfusion pressure (P(c)) was defined as mean coronary arterial pressure minus minimal left ventricular pressure. Regional flow conductances (flow/P(c)) were as follows: for the subendocardium, C(endo) = -0.103 + 0.197 DTF + 0.00074 P(c) (P < 0.001); for the midmyocardium, conductance = -0.048 + 0.126 DTF + 0.00049 P(c) (P < 0.001); and for the subepicardium, C(epi) was not significant. C(endo)-DTF relations demonstrated a finite value for DTF at which flow is zero, implying that, at physiological pressures, systolic subendocardial flow limitation extends into diastole. The DTF corresponding to an equal conductance in subendocardium and subepicardium (DTF1) was inversely related to P(c): DTF1 = 0.78 - 0.003 P(c) (P < 0.01). When heart rate and P(c) were held constant and dobutamine was administered (5 goats), contractility doubled and DTF increased by 39%, resulting in an increase of C(endo) of 40%. It is concluded that 1) DTF is a determinant of subendocardial perfusion, 2) systolic compression exerts a flow-limiting effect into diastole, and 3) corresponding to clinical findings on inducible ischemia we predict that, under hyperemic conditions, C(endo) < C(epi) if P(c) is lower than approximately 75% of a normal aortic pressure and heart rate >80 beats/min.

  2. Is correction necessary when clinically determining quantitative cerebral perfusion parameters from multi-slice dynamic susceptibility contrast MR studies?

    PubMed

    Salluzzi, M; Frayne, R; Smith, M R

    2006-01-21

    Several groups have modified the standard singular value decomposition (SVD) algorithm to produce delay-insensitive cerebral blood flow (CBF) estimates from dynamic susceptibility contrast (DSC) perfusion studies. However, new dependences of CBF estimates on bolus arrival times and slice position in multi-slice studies have been recently recognized. These conflicting findings can be reconciled by accounting for several experimental and algorithmic factors. Using simulation and clinical studies, the non-simultaneous measurement of arterial and tissue concentration curves (relative slice position) in a multi-slice study is shown to affect time-related perfusion parameters, e.g. arterial-tissue-delay measurements. However, the current clinical impact of relative slice position on amplitude-related perfusion parameters, e.g. CBF, can be expected to be small unless any of the following conditions are present individually or in combination: (a) high concentration curve signal-to-noise ratios, (b) small tissue mean transit times, (c) narrow arterial input functions or (d) low temporal resolution of the DSC image sequence. Recent improvements in magnetic resonance (MR) technology can easily be expected to lead to scenarios where these effects become increasingly important sources of inaccuracy for all perfusion parameter estimates. We show that using Fourier interpolated (high temporal resolution) residue functions reduces the systematic error of the perfusion parameters obtained from multi-slice studies.

  3. In vitro model of platelet aggregation in stenotic arteries

    SciTech Connect

    Morley, D.; Santamore, W.P.

    1988-07-01

    Clinical and experimental evidence suggest a strong relationship between arterial stenosis, platelet aggregation, and subsequent thrombus formation. To facilitate the study of platelet accumulation in stenotic arteries, we developed an in vitro preparation. Arterial segments were perfused with whole citrated blood. A stenosis was created by applying an external plastic constrictor to the artery. Platelet accumulation within the stenosis was assessed by scanning electron microscopy and by radioactive counts from Indium-111 labeled platelets. Utilizing this preparation, 30 carotid arterial segments from 10 mongrel dogs were perfused at 100 mmHg for 15 min. In 10 arteries without a stenosis, scanning electron microscopy and radioactive counts demonstrated little platelet accumulation. In contrast, extensive platelet aggregation was observed in 10 arteries with stenoses. Moreover, in 10 stenotic arteries exposed to the thromboxane mimetic, U46619 (Upjohn Diagnostic Group), scanning electron microscopy and radioactive counts demonstrated a significant increase in platelet deposition. Conversely, we demonstrated a dimunition of platelet accumulation in stenosed arterial segments exposed to the prostacyclin analogue platelet inhibitor, Iloprost. The in vitro preparation allows precise control of hemodynamic variables and makes it possible to perform multiple tests on segments of the same vessel from the same animal.

  4. Arterial cannulation can hasten the onset of symmetrical peripheral gangrene

    PubMed Central

    Srinivasan, Nataraj M.; Chaudhuri, Souvik

    2011-01-01

    Symmetrical peripheral gangrene (SPG) is a devastating complication seen in critical care settings due to several contributory factors like low perfusion, high dose of vasopressors, disseminated intravascular coagulation, etc. Arterial cannulation is commonly done in critical patients for monitoring. We report a case of patient who developed early features of SPG which recovered in one hand, although it progressed in the hand which had the arterial cannula. PMID:25885311

  5. Quantification of myocardial perfusion based on signal intensity of flow sensitized MRI

    NASA Astrophysics Data System (ADS)

    Abeykoon, Sumeda B.

    The quantitative assessment of perfusion is important for early recognition of a variety of heart diseases, determination of disease severity and their cure. In conventional approach of measuring cardiac perfusion by arterial spin labeling, the relative difference in the apparent T1 relaxation times in response to selective and non-selective inversion of blood entering the region of interest is related to perfusion via a two-compartment tissue model. But accurate determination of T1 in small animal hearts is difficult and prone to errors due to long scan times. The purpose of this study is to develop a fast, robust and simple method to quantitatively assess myocardial perfusion using arterial spin labeling. The proposed method is based on signal intensities (SI) of inversion recovery slice-select, non-select and steady-state images. Especially in this method data are acquired at a single inversion time and at short repetition times. This study began by investigating the accuracy of assessment of perfusion using a two compartment system. First, determination of perfusion by T1 and SI were implemented to a simple, two-compartment phantom model. Mathematical model developed for full spin exchange models (in-vivo experiments) by solving a modified Bloch equation was modified to develop mathematical models (T1 and SI) for a phantom (zero spin exchange). The phantom result at different flow rates shows remarkable evidence of accuracy of the two-compartment model and SI, T1 methods: the SI method has less propagation error and less scan time. Next, twelve healthy C57BL/6 mice were scanned for quantitative perfusion assessment and three of them were repeatedly scanned at three different time points for a reproducibility test. The myocardial perfusion of healthy mice obtained by the SI-method, 5.7+/-1.6 ml/g/min, was similar (p=0.38) to that obtained by the conventional T1 method, 5.6+/- 2.3 ml/g/min. The reproducibility of the SI method shows acceptable results: the

  6. The variable extent of jeopardized myocardium in patients with single vessel coronary artery disease: Quantification by thallium-201 single photon emission computed tomography

    SciTech Connect

    Mahmarian, J.J.; Pratt, C.M.; Boyce, T.M.; Verani, M.S. )

    1991-02-01

    To assess the extent of jeopardized myocardium in patients with single vessel coronary artery disease of variable severity and location, quantitative exercise thallium-201 single photon emission computed tomography was performed in 158 consecutive patients with angiographically proved single vessel coronary artery disease. The extent of abnormal left ventricular perfusion was quantified from computer-generated polar maps of three-dimensional myocardial radioactivity. Patients with only a moderate (51% to 69%) stenosis tended to have a small perfusion defect irrespective of the coronary artery involved. Whereas a perfusion defect measuring greater than or equal to 10% of the left ventricle was found in 78% of patients with no prior infarction and severe (greater than or equal to 70%) stenosis, this was observed in only 24% of patients with moderate stenosis. Perfusion defect size increased with increasing severity of stenosis for the entire group without infarction and for those with left anterior descending, right and circumflex coronary artery stenosis. However, the correlation between stenosis severity and perfusion defect size was at best only modest (r = 0.38, p = 0.0001). The left anterior descending artery was shown to be the most important of the three coronary arteries for providing left ventricular perfusion. Proximal stenosis of this artery produced a perfusion defect approximately twice as large as that found in patients with a proximal right or circumflex artery stenosis. However, marked heterogeneity in perfusion defect size existed among all three vessels despite comparable stenosis severity. This was most apparent for the left anterior descending coronary artery, where mid vessel stenosis commonly produced a perfusion defect similar in size to that found in proximally stenosed vessels.

  7. Early Support of Intracranial Perfusion

    DTIC Science & Technology

    2013-10-01

    automated real-time vital signs monitoring data” was funded by USAF (MSA); UM PI: Deborah Stein  The project, titled “Noninvasive intracranial pressure ...scoring of cerebral perfusion pressure and intracranial pressure provides a Brain Trauma Index that predicts outcome in patients with severe TBI... intracranial pressure dose index: Dynamic 3-D scoring in the assessment of Traumatic Brain Injury Proceedings of American Association for the Surgery of

  8. Anomalous origin of the right coronary artery from the pulmonary artery: an autopsied sudden death case with severe atherosclerotic disease of the left coronary artery.

    PubMed

    Nagai, T; Mukai, T; Takahashi, S; Takada, A; Saito, K; Harada, K; Mori, S; Abe, N

    2014-03-01

    Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare anomaly. It may contribute to myocardial ischemia or sudden death, although the lesion is usually asymptomatic. We report a sudden death case of a 58-year-old man with ARCAPA coexisting with severe atherosclerotic coronary artery disease. He had been healthy until he complained of chest pain, several days before death, despite the discovery of heart murmur in childhood and suspicion of valvular heart disease. The autopsy revealed not only typical findings of the right coronary anomaly with well-developed collateral circulations but also severe atherosclerotic lesions of the left coronary artery, and ischemic change of the myocardium in the left and right coronary arterial perfusion territory. In addition to the "coronary steal" phenomenon primarily caused by ARCAPA, the reduced flow of both coronary arteries and further increase of "coronary steal" due to atherosclerotic obstructive coronary disease might have contributed to the patient's death.

  9. Arterial calcifications

    PubMed Central

    Rennenberg, Roger J M W; Schurgers, Leon J; Kroon, Abraham A; Stehouwer, Coen D A

    2010-01-01

    Abstract Arterial calcifications as found with various imaging techniques, like plain X-ray, computed tomography or ultrasound are associated with increased cardiovascular risk. The prevalence of arterial calcification increases with age and is stimulated by several common cardiovascular risk factors. In this review, the clinical importance of arterial calcification and the currently known proteins involved are discussed. Arterial calcification is the result of a complex interplay between stimulating (bone morphogenetic protein type 2 [BMP-2], RANKL) and inhibitory (matrix Gla protein, BMP-7, osteoprotegerin, fetuin-A, osteopontin) proteins. Vascular calcification is especially prevalent and related to adverse outcome in patients with renal insufficiency and diabetes mellitus. We address the special circumstances and mechanisms in these patient groups. Treatment and prevention of arterial calcification is possible by the use of specific drugs. However, it remains to be proven that reduction of vascular calcification in itself leads to a reduced cardiovascular risk. PMID:20716128

  10. Intestinal perfusion monitoring using photoplethysmography

    NASA Astrophysics Data System (ADS)

    Akl, Tony J.; Wilson, Mark A.; Ericson, M. Nance; Coté, Gerard L.

    2013-08-01

    In abdominal trauma patients, monitoring intestinal perfusion and oxygen consumption is essential during the resuscitation period. Photoplethysmography is an optical technique potentially capable of monitoring these changes in real time to provide the medical staff with a timely and quantitative measure of the adequacy of resuscitation. The challenges for using optical techniques in monitoring hemodynamics in intestinal tissue are discussed, and the solutions to these challenges are presented using a combination of Monte Carlo modeling and theoretical analysis of light propagation in tissue. In particular, it is shown that by using visible wavelengths (i.e., 470 and 525 nm), the perfusion signal is enhanced and the background contribution is decreased compared with using traditional near-infrared wavelengths leading to an order of magnitude enhancement in the signal-to-background ratio. It was further shown that, using the visible wavelengths, similar sensitivity to oxygenation changes could be obtained (over 50% compared with that of near-infrared wavelengths). This is mainly due to the increased contrast between tissue and blood in that spectral region and the confinement of the photons to the thickness of the small intestine. Moreover, the modeling results show that the source to detector separation should be limited to roughly 6 mm while using traditional near-infrared light, with a few centimeters source to detector separation leads to poor signal-to-background ratio. Finally, a visible wavelength system is tested in an in vivo porcine study, and the possibility of monitoring intestinal perfusion changes is showed.

  11. Correlation of oxygenation and perfusion sensitive MRI with invasive micro probe measurements in healthy mice brain.

    PubMed

    Sedlacik, Jan; Reitz, Matthias; Bolar, Divya S; Adalsteinsson, Elfar; Schmidt, Nils O; Fiehler, Jens

    2015-03-01

    The non-invasive assessment of (patho-)physiological parameters such as, perfusion and oxygenation, is of great importance for the characterization of pathologies e.g., tumors, which may be helpful to better predict treatment response and potential outcome. To better understand the influence of physiological parameters on the investigated oxygenation and perfusion sensitive MRI methods, MRI measurements were correlated with subsequent invasive micro probe measurements during free breathing conditions of air, air+10% CO2 and 100% O2 in healthy mice brain. MRI parameters were the irreversible (R2), reversible (R2') and effective (R2*) transverse relaxation rates, venous blood oxygenation level assessed by quantitative blood oxygenation level dependent (qBOLD) method and cerebral blood flow (CBF) assessed by arterial spin labeling (ASL) using a 7 T small animal MRI scanner. One to two days after MRI, tissue perfusion and pO2 were measured by Laser-Doppler flowmetry and fluorescence quenching micro probes, respectively. The tissue pO2 values were converted to blood oxygen saturation by using the Hill equation. The animals were anesthetized by intra peritoneal injection of ketamine-xylazine-acepromazine (10-2-0.3 mg/ml · kg). Results for normal/hypercapnia/hyperoxia conditions were: R2[s(∧)-1] = 20.7/20.4/20.1, R2*[s(∧)-1] = 31.6/29.6/25.9, R2'[s-(∧)1] = 10.9/9.2/5.7, qBOLD venous blood oxygenation level = 0.43/0.51/0.56, CBF[ml · min(∧)-1 · 100 g(∧)-1] = 70.6/105.5/81.8, Laser-Doppler flowmetry[a.u.] = 89.2/120.2/90.6 and pO2[mmHg] = 6.3/32.3/46.7. All parameters were statistically significantly different with P < 0.001 between all breathing conditions. All MRI and the corresponding micro probe measurements were also statistically significantly (P ≤ 0.03) correlated with each other. However, converting the tissue pO2 to blood oxygen saturation = 0.02/0.34/0.63, showed only very limited agreement with the qBOLD venous blood oxygenation level. We found

  12. Combination Therapy of Transcatheter Arterial Chemoembolization and Arterial Administration of Antiangiogenesis on VX2 Liver Tumor

    SciTech Connect

    Deng Gang; Zhao DenglLing; Li Guangchao; Yu Hui; Teng Gaojun

    2011-08-15

    Purpose: This study was designed to evaluate the antitumorigenic efficiency of Endostar (an antiangiogenic agent) arterially administrated combined with transcatheter arterial chemoembolization (TACE) on liver tumor, and validation of perfusion CT for quantitative measurements of the results.Experimental DesignThirty rabbits bearing VX2 liver tumors were randomly and equally distributed into three groups. One of the following treatment protocols was performed in each group: 1) group 1 was treated with TACE and simultaneously arterially administrated Endostar; 2) group 2 with TACE alone, and 3) a control group that had saline injected through hepatic artery. Routine CT scan was performed before treatment, and perfusion CT imaging was performed 2 weeks after treatment. Immunohistochemical biomarkers of microvascular density (MVD) and the expression of vascular endothelial growth factor (VEGF) were measured for assessments of angiogenesis. Results: We observed a statistically significant reduction from the control in the volume, growth rate, and size of the tumor 2 weeks after treatment with both TACE plus Endostar and with TACE alone (P < 0.01). Although there was no statistically significant difference in tumor size between the group with TACE plus Endostar and the group with TACE alone (P > 0.05), MVD and VEGF were significantly less expressed in the TACE plus Endostar group than both groups with TACE alone and the control group (P < 0.01). Blood flow (BF), blood volume (BV), and permeability-surface area products (PS) in the group with TACE plus Endostar on perfusion CT were significantly higher than other two groups (P < 0.05), which were positively correlated with the MVD and VEGF values (P < 0.05). Conclusions: TACE with arterial administration of Endostar simultaneously significantly inhibited the angiogenesis biomarkers associated with TACE in a rabbit model bearing VX2 liver tumor, which indicates that the combined treatment protocol may have potential

  13. Selective cerebro-myocardial perfusion in complex congenital aortic arch pathology: a novel technique.

    PubMed

    De Rita, Fabrizio; Lucchese, Gianluca; Barozzi, Luca; Menon, Tiziano; Faggian, Giuseppe; Mazzucco, Alessandro; Luciani, Giovanni Battista

    2011-11-01

    Simultaneous cerebro-myocardial perfusion has been described in neonatal and infant arch surgery, suggesting a reduction in cardiac morbidity. Here reported is a novel technique for selective cerebral perfusion combined with controlled and independent myocardial perfusion during surgery for complex or recurrent aortic arch lesions. From April 2008 to April 2011, 10 patients with arch pathology underwent surgery (two hypoplastic left heart syndrome [HLHS], four recurrent arch obstruction, two aortic arch hypoplasia + ventricular septal defect [VSD], one single ventricle + transposition of the great arteries + arch hypoplasia, one interrupted aortic arch type B + VSD). Median age was 63 days (6 days-36 years) and median weight 4.0 kg (1.6-52). Via midline sternotomy, an arterial cannula (6 or 8 Fr for infants) was directly inserted into the innominate artery or through a polytetrafluoroethylene (PTFE) graft (for neonates <2.0 kg). A cardioplegia delivery system was inserted into the aortic root. Under moderate hypothermia, ascending and descending aorta were cross-clamped, and "beating heart and brain" aortic arch repair was performed. Arch repair was composed of patch augmentation in five, end-to-side anastomosis in three, and replacement in two patients. Average cardiopulmonary bypass time was 163 ± 68 min (71-310). In two patients only (one HLHS, one complex single ventricle), a period of cardiac arrest was required to complete intracardiac repair. In such cases, antegrade blood cardioplegia was delivered directly via the same catheter used for selective myocardial perfusion. Average time of splanchnic ischemia during cerebro-myocardial perfusion was 39 ± 18 min (17-69). Weaning from cardiopulmonary bypass was achieved without inotropic support in three and with low dose in seven patients. One patient required veno-arterial extracorporeal membrane oxygenation. Four patients, body weight <3.0 kg, needed delayed sternal closure. No neurologic dysfunction was noted

  14. Pressure- and flow-controlled media perfusion differently modify vascular mechanics in lung decellularization.

    PubMed

    da Palma, Renata K; Campillo, Noelia; Uriarte, Juan J; Oliveira, Luis V F; Navajas, Daniel; Farré, Ramon

    2015-09-01

    Organ biofabrication is a potential future alternative for obtaining viable organs for transplantation. Achieving intact scaffolds to be recellularized is a key step in lung bioengineering. Perfusion of decellularizing media through the pulmonary artery has shown to be effective. How vascular perfusion pressure and flow vary throughout lung decellularization, which is not well known, is important for optimizing the process (minimizing time) while ensuring scaffold integrity (no barotrauma). This work was aimed at characterizing the pressure/flow relationship at the pulmonary vasculature and at how effective vascular resistance depends on pressure- and flow-controlled variables when applying different methods of media perfusion for lung decellularization. Lungs from 43 healthy mice (C57BL/6; 7-8 weeks old) were investigated. After excision and tracheal cannulation, lungs were inflated at 10 cmH2O airway pressure and subjected to conventional decellularization with a solution of 1% sodium dodecyl sulfate (SDS). Pressure (PPA) and flow (V'PA) at the pulmonary artery were continuously measured. Decellularization media was perfused through the pulmonary artery: (a) at constant PPA=20 cmH2O or (b) at constant V'PA=0.5 and 0.2 ml/min. Effective vascular resistance was computed as Rv=PPA/V'PA. Rv (in cmH2O/(ml/min)); mean±SE) considerably varied throughout lung decellularization, particularly for pressure-controlled perfusion (from 29.1±3.0 in baseline to a maximum of 664.1±164.3 (p<0.05), as compared with flow-controlled perfusion (from 49.9±3.3 and 79.5±5.1 in baseline to a maximum of 114.4±13.9 and 211.7±70.5 (p<0.05, both), for V'PA of 0.5 and 0.2 ml/min respectively. Most of the media infused to the pulmonary artery throughout decellularization circulated to the airways compartment across the alveolar-capillary membrane. This study shows that monitoring perfusion mechanics throughout decellularization provides information relevant for optimizing the process

  15. Pressure Myography to Study the Function and Structure of Isolated Small Arteries.

    PubMed

    Schjørring, Olav L; Carlsson, Rune; Simonsen, Ulf

    2015-01-01

    Small arteries play an important role in regulation of peripheral resistance and organ perfusion. Here we describe a series of methods allowing measurements in pressurized segments of small arteries from the systemic and coronary circulation of mice as well as other species. The pressure myography techniques described include measurements of wall structure, wall stress, strain, and myogenic tone. The pressurized perfused small arteries also allow evaluation of responses to increases in pressure, flow, and drugs, where the main readout is changes in vascular diameter.

  16. Inner ear drug delivery via a reciprocating perfusion system in the guinea pig

    PubMed Central

    Chen, Zhiqiang; Kujawa, Sharon G.; McKenna, Michael J.; Fiering, Jason O.; Mescher, Mark J.; Borenstein, Jeffrey T.; Leary Swan, Erin E.; Sewell, William F.

    2007-01-01

    Rapid progress in understanding the molecular mechanisms associated with cochlear and auditory nerve degenerative processes offers hope for the development of gene-transfer and molecular approaches to treat these diseases in patients. For therapies based on these discoveries to become clinically useful, it will be necessary to develop safe and reliable mechanisms for the delivery of drugs into the inner ear, bypassing the blood–labyrinthine barrier. Toward the goal of developing an inner ear perfusion device for human use, a reciprocating microfluidic system that allows perfusion of drugs into the cochlear perilymph through a single inlet hole in scala tympani of the basal turn was developed. The performance of a prototype, extracorporeal reciprocating perfusion system in guinea pigs is described. Analysis of the cochlear distribution of compounds after perfusion took advantage of the place-dependent generation of responses to tones along the length of the cochlea. Perfusion with a control artificial perilymph solution had no effect. Two drugs with well-characterized effects on cochlear physiology, salicylate (5 mM) and DNQX (6,7-Dinitroquinoxaline-2,3-dione; 100 and 300 μM), reversibly altered responses. The magnitude of drug effect decreased with distance from the perfusion pipette for up to 10 mm, and increased with dose and length of application. PMID:16274830

  17. The mesenterially perfused rat small intestine: A versatile approach for pharmacological testings.

    PubMed

    Schreiber, Dominik; Klotz, Markus; Laures, Kerstin; Clasohm, Jasmin; Bischof, Michael; Schäfer, Karl-Herbert

    2014-05-01

    Pharmaceutical compounds enter the body via several major natural gateways; i.e. the lung, the skin and the gastrointestinal tract. Drug application during surgical operations can lead to severe impairment of gastrointestinal motility, which can contribute to a paralytic ileus. Here we investigated an ex vivo perfused small intestine model that allows us to ascertain the influence of pharmaceuticals upon the gut. Corresponding segments from the proximal jejunum of adult rats were used. Their mesenteric arteries and veins were cannulated and the jejunal segment excised. The individual segments were placed in a custom designed perfusion chamber and perfusion performed through the intestinal lumen as well as the mesenteric superior artery. Three test drugs, which are commonly used in anesthesiology; i.e. pentobarbital, propofol and ketamine were administered via the blood vessels. Their effects upon gastrointestinal motility patterns were evaluated by optical measurements. Longitudinal and pendular movements were distinguishable and separately analyzed. Pharmacological effects of the individual substances could be investigated. Propofol (50-200 μg/ml) was found to decrease intestinal motility, especially longitudinal movements in a dose dependent manner. Pentobarbital decreased intestinal motility only at high concentrations, above 2.5 mg/ml. A dose of 2.5 mg/ml lead to an increase in longitudinal- and pendular movements in comparison to control, while ketamine (2.5-10 mg/ml) did not alter intestinal motility at all. Histological examination of the perfused segments revealed only minor changes in tissue morphology after perfusion. The perfusion approach shown here allows for the identification of compounds which interfere with gut motility in a highly sophisticated way. It is suitable for characterization of drug and dose specific changes in motility patterns and can be used in drug development and preclinical studies.

  18. Myocardial perfusion scintigraphy and coronary disease risk factors in systemic lupus erythematosus

    PubMed Central

    Sella, E; Sato, E; Leite, W; Filho, J; Barbieri, A

    2003-01-01

    Objective: To evaluate the prevalence of myocardial perfusion abnormalities and the possible association between myocardial perfusion defects and traditional coronary artery disease (CAD) risk factors as well as systemic lupus erythematosus (SLE) related risk factors. Patients and methods: Female patients with SLE, disease duration >5 years, age 18–55 years, who had used steroids for at least one year were enrolled. Traditional CAD risk factors evaluated were arterial hypertension, diabetes mellitus, dyslipidaemia, postmenopausal status, smoking, obesity, and premature family CAD profile. Myocardial perfusion scintigraphy was evaluated by single photon emission computed tomography with technetium 99m-sestamibi at rest and after dipyridamole induced stress. Results: Eight two female patients with SLE without angina pectoris with mean (SD) age 37 (10) years, disease duration 127 (57) months, SLE Disease Activity Index (SLEDAI) score 6 (5), and SLICC/ACR-DI score 2 (2) were evaluated. Myocardial perfusion abnormalities were found in 23 patients (28%). The mean (SD) number of CAD risk factors was 2.2 (1.6). There was a significant positive correlation between age and number of CAD risk factors. Lower high density lipoprotein (HDL) cholesterol level showed a significant association with abnormal scintigraphy. Logistic regression analysis showed that lower HDL cholesterol level and diabetes mellitus were associated with myocardial perfusion abnormalities. Current vasculitis was also associated with abnormal scintigraphy. Conclusions: Lower HDL cholesterol level and diabetes mellitus have a significant influence on abnormal myocardial perfusion results found in asymptomatic patients with SLE. Current vasculitis was associated with abnormal myocardial scintigraphy. These data suggest that abnormal myocardial scintigraphy may be related to subclinical atherosclerosis. PMID:14583569

  19. Pyrazinoate transport in the isolated perfused rabbit proximal tubule.

    PubMed

    Besseghir, K; Roch-Ramel, F

    1986-12-01

    The bidirectional tubular transport of pyrazinoate (PZA) was studied in the isolated perfused proximal S2 segment of rabbit kidney. PZA reabsorption was a mechanism of large capacity, temperature-dependent and requiring a normal Na+/K+-ATPase activity. PZA reabsorption was reversibly decreased when lactate was added to the perfusate, indicating that it might occur through the sodium-lactate cotransport. The addition of PAH to the bath had a slight stimulatory effect on PZA reabsorption, suggesting a component of anion exchange in the overall PZA reabsorption. However, SITS added to either the perfusate or the bathing medium induced a non-significant decrease in PZA reabsorption, confirming the minor part of an anion exchange mechanism in this reabsorptive process. PZA reabsorption was not affected by the establishment of a bath-to-lumen H+ gradient, and was only moderately decreased after carbonic anhydrase inhibition by ethoxyzolamide, in opposition to what is known for the reabsorbed anion salicylate. The secretory transport of PZA was saturable and also dependent on a normal Na+/K+-ATPase activity. It is concluded that PZA is bidirectionally transported by facilitated mechanisms in the rabbit proximal S2 segment, one major reabsorptive mechanism appearing to be a sodium-anion cotransport, which might be the sodium-lactate reabsorbing mechanism.

  20. [Interest in myocardial scintigraphy following the arterial switch procedure for transposition of the great vessels].

    PubMed

    Acar, P; Maunoury, C; Bonnet, D; Sébahoun, S; Bonhoeffer, P; Hallaj, I; Aggoun, Y; Iserin, F; Sidi, D; Kachaner, J

    2001-05-01

    Coronary artery obstruction is the main late complication of the so-called arterial switch operation designed to repair transpositions of the great arteries in newborn infants by switching the great vessels and transferring the coronary ostia onto the posterior vessel. Our aim was to study the links between myocardial perfusion and coronary artery anatomy after the arterial switch operation. Forty-five patients (5.863 years) underwent a 201Tl myocardial SPECT and a selective coronary artery angiography. The latter was normal in 20 children: 13 had also a normal myocardial scan but 7 had myocardial perfusion defects including 2 with angina who had a very low coronary reserve at positron emission tomography. Twenty-five patients had severe coronary artery lesions: 5 with a normal myocardial scan and 20 with perfusion defects. Twelve out of these 20 underwent surgical revascularization and the SPECT images went back to normal in all within 6 months after surgery. Specificity and sensitivity of myocardial SPECT in detecting coronary artery lesions were 78% and 69% whereas positive and negative predictive values were 74 and 73%. We conclude that myocardial SPECT imaging is not the right way to detect late post arterial switch coronary artery lesions. It is helpful in decision making as to submit these children to surgical revascularization and in assessing its postoperative effectiveness.

  1. Investigation of source-detector separation optimization for an implantable perfusion and oxygenation sensor for liver blood vessels

    SciTech Connect

    Baba, Justin S; Akl, Tony; Cote, Gerard L.; Wilson, Mark A.; Ericson, Milton Nance

    2011-01-01

    An implanted system is being developed to monitor transplanted liver health during the critical 7-10 day period posttransplantation. The unit will monitor organ perfusion and oxygen consumption using optically-based probes placed on both the inflow and outflow blood vessels, and on the liver parenchymal surface. Sensing probes are based on a 3- wavelength LED source and a photodiode detector. Sample diffuse reflectance is measured at 735, 805, and 940 nm. To ascertain optimal source-to-photodetector spacing for perfusion measurement in blood vessels, an ex vivo study was conducted. In this work, a dye mixture simulating 80% blood oxygen saturation was developed and perfused through excised porcine arteries while collecting data for various preset probe source-to-photodetector spacings. The results from this study demonstrate a decrease in the optical signal with decreasing LED drive current and a reduction in perfusion index signal with increasing probe spacing. They also reveal a 2- to 4-mm optimal range for blood vessel perfusion probe source-to-photodetector spacing that allows for sufficient perfusion signal modulation depth with maximized signal to noise ratio (SNR). These findings are currently being applied to guide electronic configuration and probe placement for in vivo liver perfusion porcine model studies.

  2. Peripheral Artery Disease

    MedlinePlus

    ... Physician Resources Professions Site Index A-Z Peripheral Artery Disease (PAD) Peripheral artery disease (PAD) refers to ... is peripheral artery disease treated? What is peripheral artery disease (PAD)? Peripheral artery disease, or PAD, refers ...

  3. Mesenteric artery ischemia

    MedlinePlus

    ... bowel - mesenteric; Dead gut - mesenteric; Atherosclerosis - mesenteric artery; Hardening of the arteries - mesenteric artery ... the aorta, the main artery from the heart. Hardening of the arteries occurs when fat, cholesterol, and ...

  4. Ultrasound perfusion signal processing for tumor detection

    NASA Astrophysics Data System (ADS)

    Kim, MinWoo; Abbey, Craig K.; Insana, Michael F.

    2016-04-01

    Enhanced blood perfusion in a tissue mass is an indication of neo-vascularity and a sign of a potential malignancy. Ultrasonic pulsed-Doppler imaging is a preferred modality for noninvasive monitoring of blood flow. However, the weak blood echoes and disorganized slow flow make it difficult to detect perfusion using standard methods without the expense and risk of contrast enhancement. Our research measures the efficiency of conventional power-Doppler (PD) methods at discriminating flow states by comparing measurement performance to that of an ideal discriminator. ROC analysis applied to the experimental results shows that power Doppler methods are just 30-50 % efficient at perfusion flows less than 1ml/min, suggesting an opportunity to improve perfusion assessment through signal processing. A new perfusion estimator is proposed by extending the statistical discriminator approach. We show that 2-D perfusion color imaging may be enhanced using this approach.

  5. Traumatic Brachial Artery Injuries

    PubMed Central

    Ergunes, Kazim; Yilik, Levent; Ozsoyler, Ibrahim; Kestelli, Mert; Ozbek, Cengiz; Gurbuz, Ali

    2006-01-01

    We performed this retrospective study to analyze our strategies for managing and surgically treating brachial artery injuries. Fifty-seven patients with a total of 58 traumatic brachial artery injuries underwent surgery at our institution, from August 1996 through November 2004. Fifty-four patients were male and 3 were female (age range, 7 to 75 years; mean, 29.4 years). Forty-four of the patients had penetrating injuries (18 had stab wounds; 16, window glass injuries; and 10, industrial accidents), 10 had blunt trauma injuries (traffic accidents), and 3 had gunshot injuries. Fourteen patients (24.6%) had peripheral nerve injury. All patients underwent Doppler ultrasonographic examination. The repair of the 58 arterial injuries involved end-to-end anastomosis for 32 injuries (55.2%), reverse saphenous vein graft interpositional grafts for 18 (31%), and primary repair for 8 (13.8%). Venous continuity was achieved in 11 (84.6%) of 13 patients who had major venous injuries. Nine of the 57 patients (15.8%) required primary fasciotomy. Follow-up showed that 5 of the 14 patients with peripheral nerve injury had apparent disabilities due to nerve injury. One patient underwent amputation. There were no deaths. We believe that good results can be achieved in patients with brachial artery injuries by use of careful physical examination, Doppler ultrasonography, and restoration of viability with vascular repair and dbridement of nonviable tissues. Traumatic neurologic injury frequently leads to disability of the extremities. PMID:16572866

  6. Wiener filtering improves quantification of regional myocardial perfusion with thallium-201 SPECT

    SciTech Connect

    Links, J.M.; Jeremy, R.W.; Dyer, S.M.; Frank, T.L.; Becker, L.C. )

    1990-07-01

    Quantitation of myocardial perfusion with thallium-201 (201Tl) SPECT is limited by finite resolution and image noise. This study examined whether Wiener filtering could improve quantitation of the severity of myocardial perfusion deficits. In 19 anesthetized dogs, adjustable stenoses were placed on the left anterior descending (LAD, n = 12) or circumflex (LCx, n = 7) arteries. Thallium-201 SPECT images were acquired during maximal coronary vasodilation with dipyridamole, and simultaneous measurements of myocardial blood flow were made with microspheres. The relationship between SPECT and microsphere flow deficits in the LAD region was significantly better (p less than 0.05) with Wiener filtering (Y = 0.90X + 0.03, r = 0.78) than with conventional Hanning filtering (Y = 0.66X + 0.34, r = 0.61). Similarly, in the LCx region the relationship between SPECT and microsphere perfusion deficits was better (p less than 0.01) with the Wiener filter (Y = 0.91X + 0.07, r = 0.66) than with the Hanning filter (Y = 0.36X + 0.50, r = 0.40). Wiener filtering improves quantitation of the severity of regional myocardial perfusion deficits, allowing better assessment of the functional significance of coronary artery stenoses.

  7. /sup 201/Tl scintigraphy after surgical repair of hemodynamically significant primary coronary artery anomalies

    SciTech Connect

    Rajfer, S.I.; Oetgen, W.J.; Weeks, K.D. Jr.; Kaminski, R.J.; Rocchini, A.P.

    1982-06-01

    Nine patients with hemodynamically significant congenital coronary artery anomalies underwent surgical repair at our institution during the period 1960 to 1979. Four received diagnoses of anomalous left coronary artery arising from the pulmonary artery, while five patients had coronary artery fistulae. Stress /sup 201/Tl scintigraphy was performed on these patients 0.5 to 18 years after surgical correction as a means of assessing the adequacy of myocardial perfusion. No perfusion defects were visualized on any of the thallium studies. The surgical procedure used did not appear to influence the results of /sup 201/Tl stress imaging. Thus, these nine patients with surgically corrected primary coronary artery anomalies had no evidence of ischemia as assessed by stress thallium scintigraphy. Serial preoperative and postoperative thallium studies are now indicated to determine the role of this procedure in the management of hemodynamically significant congenital coronary artery anomalies.

  8. Thermally-mediated ultrasound-induced contraction of equine muscular arteries in vitro and an investigation of the associated cellular mechanisms.

    PubMed

    Martin, Eleanor M; Duck, Francis A; Winlove, C Peter

    2012-01-01

    We have previously shown that MHz frequency ultrasound causes contraction of the carotid artery in vitro. We now extend this investigation to equine mesenteric arteries and investigate the cellular mechanisms. In vitro exposure of the large lateral cecal mesenteric artery to 4-min periods of 3.2 MHz continuous wave ultrasound at acoustic powers up to 145 mW induced reversible repeatable contraction. The magnitude of the response was linearly dependent on acoustic power and, at 145 mW, the mean increase in wall stress was 0.020 ± 0.017 mN/mm(2) (n = 34). These results are consistent with our previous study and the effect was hypothesised to be thermally mediated. A 2°C temperature rise produced an increase in intracellular calcium, measured by Fluo-4 fluorescence. Inhibition of the inward-rectifier potassium ion channel with BaCl(2) (4 μM) increased the response to ultrasound by 55% ± 49%, indicating a similar electrophysiologic basis to the response to mild hyperthermia. In small mesenteric arteries (0.5-1.0 mm diameter) mounted in a perfusion myograph, neither ultrasound exposure nor heating produced measureable vasoconstriction or a rise in intracellular calcium and we conclude that temperature-sensitive channels are absent or inactive in these small vessels. It, therefore, appears that response of blood vessels to ultrasound depends not only on the thermal properties of the vessels and surrounding tissues but also on the electrophysiology of the smooth muscle cells.

  9. Transient left ventricular cavitary dilation during dipyridamole-thallium imaging as an indicator of severe coronary artery disease

    SciTech Connect

    Lette, J.; Lapointe, J.; Waters, D.; Cerino, M.; Picard, M.; Gagnon, A. )

    1990-11-15

    Transient left ventricular (LV) cavitary dilation during dipyridamole-thallium imaging was reported in 45 of 510 (9%) consecutive patients referred for dipyridamole-thallium imaging. Clinical and hemodynamic effects observed during dipyridamole infusion were not predictive of transient cavitary dilation on the thallium images. Coronary angiography was performed in 32 of the 45 patients: 75% had either left main, 3-vessel or high-risk 2-vessel coronary artery disease. Although 25 of 45 patients (56%) with transient cavitary dilation were either asymptomatic or had only grade 1/4 effort angina, 16 of 25 patients (64%) not referred for coronary revascularization sustained a cardiac event during a mean follow-up of 12 months. Most events were cardiac deaths (75%) and 87% of events occurred within 4 months of the test. Noncardiac surgery was performed in 187 of the 510 patients. The postoperative cardiac event rate was 2% in the 101 patients with normal scans or fixed defects, 19% in 75 patients with reversible perfusion defects and 58% in 12 patients with reversible cavitary dilation (p less than 0.0001). Thus, transient LV dilation during dipyridamole-thallium imaging is a marker of severe underlying coronary artery disease, denotes a poor prognosis and predicts a high risk of postoperative cardiac complications in patients who undergo noncardiac surgery.

  10. Induced Human Decidual NK-Like Cells Improve Utero-Placental Perfusion in Mice

    PubMed Central

    Pernicone, Elizabeth; Korkes, Henri A.; Burke, Suzanne D.; Rajakumar, Augustine; Thadhani, Ravi I.; Roberts, Drucilla J.; Bhasin, Manoj; Karumanchi, S. Ananth

    2016-01-01

    Decidual NK (dNK) cells, a distinct type of NK cell, are thought to regulate uterine spiral artery remodeling, a process that allows for increased blood delivery to the fetal-placental unit. Impairment of uterine spiral artery remodeling is associated with decreased placental perfusion, increased uterine artery resistance, and obstetric complications such as preeclampsia and intrauterine growth restriction. Ex vivo manipulation of human peripheral blood NK (pNK) cells by a combination of hypoxia, TGFß-1 and 5-aza-2’-deoxycytidine yields cells with phenotypic and in vitro functional similarities to dNK cells, called idNK cells. Here, gene expression profiling shows that CD56Bright idNK cells derived ex vivo from human pNK cells, and to a lesser extent CD56Dim idNK cells, are enriched in the gene expression signature that distinguishes dNK cells from pNK cells. When injected into immunocompromised pregnant mice with elevated uterine artery resistance, idNK cells homed to the uterus and reduced the uterine artery resistance index, suggesting improved placental perfusion. PMID:27736914

  11. Positron emission tomography detects tissue metabolic activity in myocardial segments with persistent thallium perfusion defects

    SciTech Connect

    Brunken, R.; Schwaiger, M.; Grover-McKay, M.; Phelps, M.E.; Tillisch, J.; Schelbert, H.R.

    1987-09-01

    Positron emission tomography with /sup 13/N-ammonia and /sup 18/F-2-deoxyglucose was used to assess myocardial perfusion and glucose utilization in 51 myocardial segments with a stress thallium defect in 12 patients. Myocardial infarction was defined by a concordant reduction in segmental perfusion and glucose utilization, and myocardial ischemia was identified by preservation of glucose utilization in segments with rest hypoperfusion. Of the 51 segments studied, 36 had a fixed thallium defect, 11 had a partially reversible defect and 4 had a completely reversible defect. Only 15 (42%) of the 36 segments with a fixed defect and 4 (36%) of the 11 segments with a partially reversible defect exhibited myocardial infarction on study with positron tomography. In contrast, residual myocardial glucose utilization was identified in the majority of segments with a fixed (58%) or a partially reversible (64%) thallium defect. All of the segments with a completely reversible defect appeared normal on positron tomography. Apparent improvement in the thallium defect on delayed images did not distinguish segments with ischemia from infarction. Thus, positron emission tomography reveals evidence of persistent tissue metabolism in the majority of segments with a fixed or partially resolving stress thallium defect, implying that markers of perfusion alone may underestimate the extent of viable tissue in hypoperfused myocardial segments.

  12. Visualization of pressure-dependent luxury perfusion in a patient with subacute cerebral infarction.

    PubMed

    Cho, I H; Hayashida, K; Kume, N; Shimotsu, Y; Miyashita, K

    1998-08-01

    Luxury perfusion characterized by depressed metabolism compared with CBF might be changed by decreasing cerebral perfusion pressure during the sitting position. A 77-yr-old man with subacute cerebral infarction was studied with brain X-ray computed tomography (CT), raise-up test with 99mTc-d,1-hexamethylpropyleneamine oxime (HMPAO) brain single photon emission tomography (SPECT) and positron emission tomography (PET). Brain X-ray CT revealed a low-density area in the left middle cerebral artery (MCA) anterior area. Raise-up 99mTc-HMPAO brain SPECT revealed decreased uptake in the left MCA anterior area in the sitting position and subsequent supine 99mTc-HMPAO brain SPECT revealed hot accumulation there. PET study in the supine position demonstrated some differences between CBF and the cerebral metabolic rate for oxygen in the left MCA anterior area, indicating luxury perfusion. CBF in the area of luxury perfusion might be decreased during the sitting or standing position and increased during the supine position by dysautoregulation of the cerebral vessels in the luxury perfusion during the subacute infarct.

  13. Comparison of Regional Brain Perfusion Levels in Chronically Smoking and Non-Smoking Adults

    PubMed Central

    Durazzo, Timothy C.; Meyerhoff, Dieter J.; Murray, Donna E.

    2015-01-01

    Chronic cigarette smoking is associated with numerous abnormalities in brain neurobiology, but few studies specifically investigated the chronic effects of smoking (compared to the acute effects of smoking, nicotine administration, or nicotine withdrawal) on cerebral perfusion (i.e., blood flow). Predominately middle-aged male (47 ± 11 years of age) smokers (n = 34) and non-smokers (n = 27) were compared on regional cortical perfusion measured by continuous arterial spin labeling magnetic resonance studies at 4 Tesla. Smokers showed significantly lower perfusion than non-smokers in the bilateral medial and lateral orbitofrontal cortices, bilateral inferior parietal lobules, bilateral superior temporal gyri, left posterior cingulate, right isthmus of cingulate, and right supramarginal gyrus. Greater lifetime duration of smoking (adjusted for age) was related to lower perfusion in multiple brain regions. The results indicated smokers showed significant perfusion deficits in anterior cortical regions implicated in the development, progression, and maintenance of all addictive disorders. Smokers concurrently demonstrated reduced blood flow in posterior brain regions that show morphological and metabolic aberrations as well as elevated beta amyloid deposition demonstrated by those with early stage Alzheimer disease. The findings provide additional novel evidence of the adverse effects of cigarette smoking on the human brain. PMID:26193290

  14. Ventilation/perfusion lung scan in pulmonary veno-occlusive disease.

    PubMed

    Seferian, Andrei; Helal, Badia; Jaïs, Xavier; Girerd, Barbara; Price, Laura C; Günther, Sven; Savale, Laurent; Dorfmüller, Peter; Parent, Florence; Sitbon, Olivier; Humbert, Marc; Simonneau, Gérald; Montani, David

    2012-07-01

    Pulmonary veno-occlusive disease (PVOD), a rare form of pulmonary arterial hypertension (PAH), requires histological proof for definitive diagnosis; however, lung biopsy is not recommended in PAH. Recent conjoint European Respiratory Society/European Society of Cardiology guidelines suggest that nonmatched perfusion defects on ventilation/perfusion (V'/Q') lung scanning in PAH patients may suggest PVOD. The aim of our study was to evaluate V'/Q' lung scans in a large cohort of PVOD and idiopathic or heritable PAH patients. V'/Q' lung scans from 70 patients with idiopathic or heritable PAH and 56 patients with confirmed or highly probable PVOD were reviewed in a double-blind manner. The vast majority of V'/Q' lung scans were normal or without significant abnormalities in both groups. No differences in ventilation or perfusion lung scans were observed between PAH and PVOD patients (all p>0.05). Furthermore, no differences were observed between confirmed (n=31) or highly probable PVOD (n=25). Nonmatched perfusion defects were found in seven (10%) idiopathic PAH patients and four (7.1%) PVOD patients (p>0.05). Nonmatched perfusion defects were rarely seen in a large cohort of idiopathic or heritable PAH and PVOD patients. Future recommendations should be amended according to these results suggesting that V'/Q' lung scanning is not useful in discriminating PVOD from idiopathic PAH.

  15. Characterization of renal parenchymal perfusion during experimental infrarenal aortic clamping and declamping with enhanced thermodiffusion electrodes.

    PubMed

    Kraus, T; Mehrabi, A; Angelescu, M; Golling, M; Allenberg, J R; Klar, E

    2001-07-01

    Despite multiple previous experimental and clinical investigations, it has not been fully clarified until now whether infrarenal aortic cross-clamping (IRAC) induces a significant disturbance of renal parenchymal perfusion. Most renal cortical flow data collected thus far have been heterogenous because of inherent limitations of available measurement technology. The enhanced thermal diffusion (TD) electrode is a newly developed and previously validated prototype device that allows continuous quantification of parenchymal kidney perfusion after local probe implantation. We monitored renal perfusion during experimental IRAC with TD for the first time, thereby also evaluating the potential applicability of the method in clinical aortic surgery. IRAC (20 min) followed by sudden declamping was performed in pigs under general anesthesia (n = 14). Renal cortical blood flow (RCBF) was continuously quantified by TD, total aortic flow (TABF) and renal artery flow (RABF) were measured by ultrasonic flow probes, and parameters of systemic circulation were determined by Swan-Ganz catheter. Our results showed that kidney perfusion can be continuously quantified using TD electrodes during experimental aortic surgery in a porcine model. IRAC does not lead to a significant impairment of RCBF in young pigs as measured by TD. Renal perfusion appears to be predominantly pressure driven. Consequently, abrubt aortic declamping can bring about prolonged renal ischemia. Transfer of the TD method to RCBF monitoring during clinical aortic surgery appears to be feasible and should be investigated in selected cases.

  16. Cortical perfusion index: A predictor of acute rejection in transplanted kidneys

    SciTech Connect

    Atkins, H.L.; Oster, Z.H.; Anaise, D.; Wein, S.; Waltzer, W.; Gonder, A.; Cooch, E.; Rapaport, F.T.

    1985-05-01

    The presently available non-invasive methods for the diagnosis of acute rejection crisis (ARC) of renal transplants are not satisfactory. However, the need for such a test is of paramount clinical importance. A prospective study of 74 post-transplantation events in renal allograft recipients was performed. Clinical, surgical exploration and biopsy data were correlated with TC-99m DTPA scintigraphy using the following indices: Global perfusion index (GPI), cortical perfusion index (CPI), medullary perfusion index (MPI), the peak-to-plateau ratio (P/P), iliac artery peak to renal peak time (delta-P) and washout half-time (T1/2). Of the 74 events, 24 were proven to be due to acute rejection crisis (ARC), 13 were of ureteral obstruction, 18 various nephropathies and 19 in stable renal transplant function. The P/P, delta-P and T1/2 were not good predictors of ARC; the sensitivity was 79%, 79% and 80% respectively. The sensitivity of the GPI was 58% and the specificity was 87%. The cortical perfusion index rated better: specificity=84% and sensitivity=87%. However, the best indicator of ARC seemed to be the percent increase in cortical perfusion index over previous values obtained during stable graft function. Thus the sensitivity was found to be 91% and specificity was 96%. The difference between global and cortical perfusion indices reflects shunting of blood for cortex to medulla. This study suggest that the cortical perfusion index (CPI) and the percent increase in CPI can be used to non-invasively diagnose acute renal allograft rejection.

  17. Risk assessment by myocardial perfusion imaging for coronary revascularization, medical therapy, and noncardiac surgery.

    PubMed

    Papaioannou, Georgios I; Heller, Gary V

    2003-01-01

    Stress myocardial perfusion imaging (MPI) has become an important tool in risk stratification of patients with known coronary artery disease. A normal myocardial perfusion scan has a high negative predictive value and is associated with low annual mortality rate (< 1%). Patients with extensive ischemia (> 20% of the left ventricle), defects in more than 1 coronary vascular territory, transient or persistent left ventricular cavity dilation, and ejection fraction less than 45% have a high annual mortality rate (> 3%). Those patients should undergo coronary revascularization whenever feasible, as the cardiac event rate increases in proportion to the magnitude of the jeopardized myocardium. Stress MPI can be used to demonstrate ischemia in patients with symptoms early after coronary artery bypass surgery (< 5 years) or in those without symptoms late (>/= 5 years) after coronary artery bypass surgery. With respect to patients who underwent percutaneous interventions, stress MPI can help detect in-stent restenosis early after the intervention (3-6 months) or assess the progression of native coronary disease afterward. Since preliminary data suggest that a reduction in the perfusion defect size may translate to a reduction of coronary events, stress MPI can help assess the efficacy of medical management of coronary disease. Finally, stress MPI is indicated for perioperative cardiac risk stratification for noncardiac surgery in patients with intermediate risk predictors (mild angina, prior myocardial infarction or heart failure symptoms, diabetes mellitus, renal insufficiency) and poor functional capacity or in those who undergo high-risk surgery with significant implications in further preoperative management.

  18. Perfusion imaging with non-contrast ultrasound

    NASA Astrophysics Data System (ADS)

    Tierney, Jaime E.; Dumont, Douglas M.; Byram, Brett C.

    2016-04-01

    A Doppler ultrasound clutter filter that enables estimation of low velocity blood flow could considerably improve ultrasound as a tool for clinical diagnosis and monitoring, including for the evaluation of vascular diseases and tumor perfusion. Conventional Doppler ultrasound is currently used for visualizing and estimating blood flow. However, conventional Doppler is limited by frame rate and tissue clutter caused by involuntary movement of the patient or sonographer. Spectral broadening of the clutter due to tissue motion limits ultrasound's ability to detect blood flow less than about 5mm/s at an 8MHz center frequency. We propose a clutter filtering technique that may increase the sensitivity of Doppler measurements to at least as low as 0.41mm/s. The proposed filter uses an adaptive demodulation scheme that decreases the bandwidth of the clutter. To test the performance of the adaptive demodulation method at removing sonographer hand motion, six volunteer subjects acquired data from a basic quality assurance phantom. Additionally, to test initial in vivo feasibility, an arterial occlusion reactive hyperemia study was performed to assess the efficiency of the proposed filter at preserving signals from blood velocities 2mm/s or greater. The hand motion study resulted in initial average bandwidths of 577Hz (28.5mm/s), which were decreased to 7.28Hz (0.36mm/s) at -60 dB at 3cm using our approach. The in vivo power Doppler study resulted in 15.2dB and 0.15dB dynamic ranges between the lowest and highest blood flow time points for the proposed filter and conventional 50Hz high pass filter, respectively.

  19. Intracranial CT angiography obtained from a cerebral CT perfusion examination

    SciTech Connect

    Gratama van Andel, H. A. F.; Venema, H. W.; Majoie, C. B.; Den Heeten, G. J.; Grimbergen, C. A.; Streekstra, G. J.

    2009-04-15

    CT perfusion (CTP) examinations of the brain are performed increasingly for the evaluation of cerebral blood flow in patients with stroke and vasospasm after subarachnoid hemorrhage. Of the same patient often also a CT angiography (CTA) examination is performed. This study investigates the possibility to obtain CTA images from the CTP examination, thereby possibly obviating the CTA examination. This would save the patient exposure to radiation, contrast, and time. Each CTP frame is a CTA image with a varying amount of contrast enhancement and with high noise. To improve the contrast-to-noise ratio (CNR) we combined all 3D images into one 3D image after registration to correct for patient motion between time frames. Image combination consists of weighted averaging in which the weighting factor of each frame is proportional to the arterial contrast. It can be shown that the arterial CNR is maximized in this procedure. An additional advantage of the use of the time series of CTP images is that automatic differentiation between arteries and veins is possible. This feature was used to mask veins in the resulting 3D images to enhance visibility of arteries in maximum intensity projection (MIP) images. With a Philips Brilliance 64 CT scanner (64x0.625 mm) CTP examinations of eight patients were performed on 80 mm of brain using the toggling table technique. The CTP examination consisted of a time series of 15 3D images (2x64x0.625 mm; 80 kV; 150 mAs each) with an interval of 4 s. The authors measured the CNR in images obtained with weighted averaging, images obtained with plain averaging, and images with maximal arterial enhancement. The authors also compared CNR and quality of the images with that of regular CTA examinations and examined the effectiveness of automatic vein masking in MIP images. The CNR of the weighted averaged images is, on the average, 1.73 times the CNR of an image at maximal arterial enhancement in the CTP series, where the use of plain averaging

  20. TU-G-204-01: BEST IN PHYSICS (IMAGING): Dynamic CT Myocardial Perfusion Measurement and Its Comparison to Fractional Flow Reserve

    SciTech Connect

    Ziemer, B; Hubbard, L; Groves, E; Sadeghi, B; Javan, H; Lipinski, J; Molloi, S

    2015-06-15

    Purpose: To evaluate a first pass analysis (FPA) technique for CT perfusion measurement in a swine animal and its validation using fractional flow reserve (FFR) as a reference standard. Methods: Swine were placed under anesthesia and relevant physiologic parameters were continuously recorded. Intra-coronary adenosine was administered to induce maximum hyperemia. A pressure wire was advanced distal to the first diagonal branch of the left anterior descending (LAD) artery for FFR measurements and a balloon dilation catheter was inserted over the pressure wire into the proximal LAD to create varying levels of stenosis. Images were acquired with a 320-row wide volume CT scanner. Three main coronary perfusion beds were delineated in the myocardium using arteries extracted from CT angiography images using a minimum energy hypothesis. The integrated density in the perfusion bed was used to calculate perfusion using the FPA technique. The perfusion in the LAD bed over a range of stenosis severity was measured. The measured fractional perfusion was compared to FFR and linear regression was performed. Results: The measured fractional perfusion using the FPA technique (P-FPA) and FFR were related as P-FPA = 1.06FFR – 0.06 (r{sup 2} = 0.86). The perfusion measurements were calculated with only three to five total CT volume scans, which drastically reduces the radiation dose as compared with the existing techniques requiring 15–20 volume scans. Conclusion: The measured perfusion using the first pass analysis technique showed good correlation with FFR measurements as a reference standard. The technique for perfusion measurement can potentially make a substantial reduction in radiation dose as compared with the existing techniques.

  1. Myocardial perfusion imaging study of CO(2)-induced panic attack.

    PubMed

    Soares-Filho, Gastão L F; Machado, Sergio; Arias-Carrión, Oscar; Santulli, Gaetano; Mesquita, Claudio T; Cosci, Fiammetta; Silva, Adriana C; Nardi, Antonio E

    2014-01-15

    Chest pain is often seen alongside with panic attacks. Moreover, panic disorder has been suggested as a risk factor for cardiovascular disease and even a trigger for acute coronary syndrome. Patients with coronary artery disease may have myocardial ischemia in response to mental stress, in which panic attack is a strong component, by an increase in coronary vasomotor tone or sympathetic hyperactivity setting off an increase in myocardial oxygen consumption. Indeed, coronary artery spasm was presumed to be present in cases of cardiac ischemia linked to panic disorder. These findings correlating panic disorder with coronary artery disease lead us to raise questions about the favorable prognosis of chest pain in panic attack. To investigate whether myocardial ischemia is the genesis of chest pain in panic attacks, we developed a myocardial perfusion study through research by myocardial scintigraphy in patients with panic attacks induced in the laboratory by inhalation of 35% carbon dioxide. In conclusion, from the data obtained, some hypotheses are discussed from the viewpoint of endothelial dysfunction and microvascular disease present in mental stress response.

  2. Reversible Sterilization

    ERIC Educational Resources Information Center

    Largey, Gale

    1977-01-01

    Notes that difficult questions arise concerning the use of sterilization for alleged eugenic and euthenic purposes. Thus, how reversible sterilization will be used with relation to the poor, mentally ill, mentally retarded, criminals, and minors, is questioned. (Author/AM)

  3. Reversible Cardiomyopathies

    PubMed Central

    Patel, Harsh; Madanieh, Raef; Kosmas, Constantine E; Vatti, Satya K; Vittorio, Timothy J

    2015-01-01

    Cardiomyopathies (CMs) have many etiological factors that can result in severe structural and functional dysregulation. Fortunately, there are several potentially reversible CMs that are known to improve when the root etiological factor is addressed. In this article, we discuss several of these reversible CMs, including tachycardia-induced, peripartum, inflammatory, hyperthyroidism, Takotsubo, and chronic illness–induced CMs. Our discussion also includes a review on their respective pathophysiology, as well as possible management solutions. PMID:26052233

  4. Isolated total lung perfusion as a means to deliver organ-specific chemotherapy: long-term studies in animals

    SciTech Connect

    Johnston, M.R.; Christensen, C.W.; Minchin, R.F.; Rickaby, D.A.; Linehan, J.H.; Schuller, H.M.; Boyd, M.R.; Dawson, C.A.

    1985-07-01

    The objectives of this study were to develop a surgical procedure that would allow for bilateral isolated lung perfusion in vivo as a means of delivering organ-specific chemotherapy and to evaluate the influence of the procedure on certain pulmonary physiologic parameters. The sterile surgical procedure that was carried out in dogs involved the setting up of two separate perfusion circuits. Once standard systemic cardiopulmonary bypass was established, a second circuit was devised to perfuse the lungs by placing an inflow cannula into the main pulmonary artery and collecting venous effluent in the left atrium. Cross-contamination between perfusion circuits was determined in acute studies with labeled plasma protein or red blood cells and was found to be in an acceptable range if the aorta was cross-clamped and the heart arrested. Only about 0.4 ml/min of pulmonary perfusate leaked into the systemic circulation, indicating that systemic toxicity should not be a major concern when chemotherapy agents are added to the pulmonary perfusate. Chronic studies demonstrated that hemodynamic parameters, lung water, pulmonary endothelial serotonin extraction, and histologic findings all showed minimal changes after 50 minutes of isolated lung perfusion. Five days after perfusion, lung dynamic compliance and peak serotonin extraction showed significant decreases. However, all of the measured parameters had returned toward baseline levels by the end of the 8-week postoperative study period. The procedure offers significant advantages over the previously described single lung perfusion and may provide a method of delivering immediate high-concentration adjuvant chemotherapy to coincide with resection of primary or metastatic lung tumors.

  5. TU-G-204-03: Dynamic CT Myocardial Perfusion Measurement Using First Pass Analysis and Maximum Slope Models

    SciTech Connect

    Hubbard, L; Ziemer, B; Sadeghi, B; Javan, H; Lipinski, J; Molloi, S

    2015-06-15

    Purpose: To evaluate the accuracy of dynamic CT myocardial perfusion measurement using first pass analysis (FPA) and maximum slope models. Methods: A swine animal model was prepared by percutaneous advancement of an angioplasty balloon into the proximal left anterior descending (LAD) coronary artery to induce varying degrees of stenosis. Maximal hyperaemia was achieved in the LAD with an intracoronary adenosine drip (240 µg/min). Serial microsphere and contrast (370 mg/mL iodine, 30 mL, 5mL/s) injections were made over a range of induced stenoses, and dynamic imaging was performed using a 320-row CT scanner at 100 kVp and 200 mA. The FPA CT perfusion technique was used to make vessel-specific myocardial perfusion measurements. CT perfusion measurements using the FPA and maximum slope models were validated using colored microspheres as the reference gold standard. Results: Perfusion measurements using the FPA technique (P-FPA) showed good correlation with minimal offset when compared to perfusion measurements using microspheres (P- Micro) as the reference standard (P -FPA = 0.96 P-Micro + 0.05, R{sup 2} = 0.97, RMSE = 0.19 mL/min/g). In contrast, the maximum slope model technique (P-MS) was shown to underestimate perfusion when compared to microsphere perfusion measurements (P-MS = 0.42 P -Micro −0.48, R{sup 2} = 0.94, RMSE = 3.3 mL/min/g). Conclusion: The results indicate the potential for significant improvements in accuracy of dynamic CT myocardial perfusion measurement using the first pass analysis technique as compared with the standard maximum slope model.

  6. Pulmonary artery sarcoma masquerading as chronic pulmonary thromboembolism.

    PubMed

    Coskun, Ugur; Sinan, Umit Yasar; Calpar, Ilknur; Yildizeli, Bedrettin; Yanartas, Mehmet; Filinte, Deniz; Kucukoglu, Mehmet Serdar

    2014-10-01

    We describe the case of a 60-year-old woman who presented with pulmonary artery sarcoma, a very rare tumor of the cardiovascular system. Her tumor was initially misdiagnosed as chronic pulmonary thromboembolism, and she underwent pulmonary endarterectomy. Early diagnosis of primary pulmonary artery sarcoma is crucial. That alternative should always be considered before settling on a diagnosis of pulmonary embolism. Suspicion should be aroused by the failure of anticoagulant treatment to alleviate pulmonary perfusion abnormalities and systemic symptoms. Surgical resection of the tumor-preferably by pulmonary endarterectomy, followed by reconstruction as needed-is currently the most promising treatment for pulmonary artery sarcoma.

  7. Pulmonary Artery Sarcoma Masquerading as Chronic Pulmonary Thromboembolism

    PubMed Central

    Coskun, Ugur; Calpar, Ilknur; Yildizeli, Bedrettin; Yanartas, Mehmet; Filinte, Deniz; Kucukoglu, Mehmet Serdar

    2014-01-01

    We describe the case of a 60-year-old woman who presented with pulmonary artery sarcoma, a very rare tumor of the cardiovascular system. Her tumor was initially misdiagnosed as chronic pulmonary thromboembolism, and she underwent pulmonary endarterectomy. Early diagnosis of primary pulmonary artery sarcoma is crucial. That alternative should always be considered before settling on a diagnosis of pulmonary embolism. Suspicion should be aroused by the failure of anticoagulant treatment to alleviate pulmonary perfusion abnormalities and systemic symptoms. Surgical resection of the tumor—preferably by pulmonary endarterectomy, followed by reconstruction as needed—is currently the most promising treatment for pulmonary artery sarcoma. PMID:25425987

  8. Technetium myocardial perfusion agents: an introduction

    SciTech Connect

    English, R.J.; Kozlowski, J.; Tumeh, S.S.; Holman, B.L.

    1987-09-01

    This is the third in a series of four Continuing Education articles on developing radiopharmaceuticals. After reading this article, the reader should be able to: 1) understand the basic concepts of myocardial perfusion imaging; and 2) discuss the advantages of the technetium myocardial perfusion complexes over thallium-201.

  9. Luxury perfusion following anterior ischemic optic neuropathy.

    PubMed

    Friedland, S; Winterkorn, J M; Burde, R M

    1996-09-01

    We present five patients who developed luxury perfusion following anterior ischemic optic neuropathy in whom fluorescein angiography was misinterpreted as "capillary hemangioma" or neovascularization of the disc. In each case, the segment of disc hyperemia corresponded to a spared region of visual field. Luxury perfusion represents a reparative autoregulatory reaction to ischemia.

  10. Long term perfusion system supporting adipogenesis

    PubMed Central

    Abbott, Rosalyn D.; Raja, Waseem K.; Wang, Rebecca Y.; Stinson, Jordan A.; Glettig, Dean L.; Burke, Kelly A.; Kaplan, David L.

    2015-01-01

    Adipose tissue engineered models are needed to enhance our understanding of disease mechanisms and for soft tissue regenerative strategies. Perfusion systems generate more physiologically relevant and sustainable adipose tissue models, however adipocytes have unique properties that make culturing them in a perfusion environment challenging. In this paper we describe the methods involved in the development of two perfusion culture systems (2D and 3D) to test their applicability for long term in vitro adipogenic cultures. It was hypothesized that a silk protein biomaterial scaffold would provide a 3D framework, in combination with perfusion flow, to generate a more physiologically relevant sustainable adipose tissue engineered model than 2D cell culture. Consistent with other studies evaluating 2D and 3D culture systems for adipogenesis we found that both systems successfully model adipogensis, however 3D culture systems were more robust, providing the mechanical structure required to contain the large, fragile adipocytes that were lost in 2D perfused culture systems. 3D perfusion also stimulated greater lipogenesis and lipolysis and resulted in decreased secretion of LDH compared to 2D perfusion. Regardless of culture configuration (2D or 3D) greater glycerol was secreted with the increased nutritional supply provided by perfusion of fresh media. These results are promising for adipose tissue engineering applications including long term cultures for studying disease mechanisms and regenerative approaches, where both acute (days to weeks) and chronic (weeks to months) cultivation are critical for useful insight. PMID:25843606

  11. Retrograde coronary sinus versus aortic root perfusion with cold cardioplegia: randomized study of levels of cardiac enzymes in 40 patients

    SciTech Connect

    Guiraudon, G.M.; Campbell, C.S.; McLellan, D.G.; Kostuk, W.J.; Purves, P.D.; MacDonald, J.L.; Cleland, A.G.; Tadros, N.B.

    1986-11-01

    Myocardial injury was assessed with the use of enzyme indexes in 40 patients randomly assigned to one of two groups undergoing coronary artery bypass surgery. Twenty patients received cold cardioplegia delivered by retrograde coronary sinus perfusion and 20 received cardioplegic solution by anterograde aortic root perfusion. Creatine kinase isoenzyme MB and lactate dehydrogenese isoenzyme 1 and isoenzyme 2 assays were carried out on blood samples obtained from the coronary sinus before aortic cross-clamping and 0, 5, and 30 min after aortic unclamping. Levels of these enzymes were also obtained from venous blood samples before aortic cross-clamping and 3, 8, 14, and 20 hr after aortic unclamping and 2, 3, 4, and 5 days after surgery. Preoperative and postoperative hemodynamic measurements (Swan-Ganz catheter) and radionuclide wall motion studies were also obtained for comparison. There was no overall significant difference between the two groups postoperatively in terms of enzyme indexes, hemodynamic measurements, or results of wall motion studies. We conclude that retrograde coronary sinus perfusion is an alternative to aortic root perfusion in delivering cold cardioplegia. More studies are required to determine which subgroup of patients with coronary artery disease may benefit from retrograde coronary perfusion.

  12. Effect of clinical and RBC hemorheological parameters on myocardial perfusion in patients with type 2 diabetes mellitus.

    PubMed

    Cho, Minhee; Shin, Sehyun; Kwon, Hyuck Moon; Chung, Hyemoon; Lee, Byoung Kwon

    2014-01-01

    Myocardial ischemia may be present even when there is no significant stenosis of the epicardial coronary artery, or after coronary angioplasty for significant coronary artery disease. This phenomenon is related to disturbance of the coronary microcirculation or vasomotor tone. The aim of this study was to determine the influence of clinical and RBC hemorheological factors, such as RBC deformability and aggregation, on myocardial perfusion in patients with type 2 diabetes mellitus (DM) when compared to patients without DM, presenting with stable angina or acute coronary syndrome. Myocardial perfusion was graded using the myocardial blush grade (MBG) which describes the relative "blush" or intensity of the radio-opacity of myocardial tissue observed after an epicardial coronary injection of contrast medium during coronary angiography. MBG was counted before any medical or mechanical intervention, and in the myocardial territory without anatomical flow limitation (<50% of luminal narrowing on coronary angiogram), in order to remove the direct influence of anatomical stenosis. Myocardial perfusion in this region was associated with diabetes, renal function, LV diastolic function, inflammatory biomarkers such as hs-CRP, fibrinogen and ESR, but not with the clinical presentation. Among the hemorheological parameters, reduced myocardial perfusion was linked to increased RBC aggregation, but not to variation in RBC deformability. In conclusion, myocardial perfusion was affected by diabetes, left ventricular diastolic function, and inflammatory activity indicated by clinical parameters, and by the hemorheological factor RBC aggregation.

  13. [Compromized myocardial perfusion in arrhythmias (author's transl)].

    PubMed

    Simon, H; Neumann, G; Felix, R; Hedde, H; Schaede, A; Thurn, P; Winkler, C

    1977-09-15

    In 7 patients with arrhythmias of various origin the myocardial scintigram displayed either a diffuse or circumscript defect of the perfusion. The coronary arteriogram was normal in all patients. The localized defect of the perfusion in 2 patients was in the region of the upper part of the interventricular septum. Both had a left bundle brunch block. A correlation between the perfusion defect and the electrophysiological abnormality seems probable. The perfusion defect in one of the patients is most probably caused by a previous myocarditis followed by fibrous changes. In the other 6 patients the cause for the perfusion defect is not obvious. A history of myocarditis is missing. The presence of "small vessel disease" in those patients has however to be considered. Our results point to the relation between an abnormality of the microcirculation and arrhythmias in younger patients.

  14. Permanent cortical blindness after bronchial artery embolization.

    PubMed

    van Doorn, Colette S; De Boo, Diederick W; Weersink, Els J M; van Delden, Otto M; Reekers, Jim A; van Lienden, Krijn P

    2013-12-01

    A 35-year-old female with a known medical history of cystic fibrosis was admitted to our institution for massive hemoptysis. CTA depicted a hypertrophied bronchial artery to the right upper lobe and showed signs of recent bleeding at that location. Bronchial artery embolization (BAE) was performed with gelfoam slurry, because pronounced shunting to the pulmonary artery was present. Immediately after BAE, the patient developed bilateral cortical blindness. Control angiography showed an initially not opacified anastomosis between the embolized bronchial artery and the right subclavian artery, near to the origin of the right vertebral artery. Cessation of outflow in the bronchial circulation reversed the flow through the anastomosis and allowed for spill of embolization material into the posterior circulation. Unfortunately the cortical blindness presented was permanent.

  15. Permanent Cortical Blindness After Bronchial Artery Embolization

    SciTech Connect

    Doorn, Colette S. van De Boo, Diederick W.; Weersink, Els J. M.; Delden, Otto M. van Reekers, Jim A. Lienden, Krijn P. van

    2013-12-15

    A 35-year-old female with a known medical history of cystic fibrosis was admitted to our institution for massive hemoptysis. CTA depicted a hypertrophied bronchial artery to the right upper lobe and showed signs of recent bleeding at that location. Bronchial artery embolization (BAE) was performed with gelfoam slurry, because pronounced shunting to the pulmonary artery was present. Immediately after BAE, the patient developed bilateral cortical blindness. Control angiography showed an initially not opacified anastomosis between the embolized bronchial artery and the right subclavian artery, near to the origin of the right vertebral artery. Cessation of outflow in the bronchial circulation reversed the flow through the anastomosis and allowed for spill of embolization material into the posterior circulation. Unfortunately the cortical blindness presented was permanent.

  16. Stability of radiomic features in CT perfusion maps.

    PubMed

    Bogowicz, M; Riesterer, O; Bundschuh, R A; Veit-Haibach, P; Hüllner, M; Studer, G; Stieb, S; Glatz, S; Pruschy, M; Guckenberger, M; Tanadini-Lang, S

    2016-12-21

    This study aimed to identify a set of stable radiomic parameters in CT perfusion (CTP) maps with respect to CTP calculation factors and image discretization, as an input for future prognostic models for local tumor response to chemo-radiotherapy. Pre-treatment CTP images of eleven patients with oropharyngeal carcinoma and eleven patients with non-small cell lung cancer (NSCLC) were analyzed. 315 radiomic parameters were studied per perfusion map (blood volume, blood flow and mean transit time). Radiomics robustness was investigated regarding the potentially standardizable (image discretization method, Hounsfield unit (HU) threshold, voxel size and temporal resolution) and non-standardizable (artery contouring and noise threshold) perfusion calculation factors using the intraclass correlation (ICC). To gain added value for our model radiomic parameters correlated with tumor volume, a well-known predictive factor for local tumor response to chemo-radiotherapy, were excluded from the analysis. The remaining stable radiomic parameters were grouped according to inter-parameter Spearman correlations and for each group the parameter with the highest ICC was included in the final set. The acceptance level was 0.9 and 0.7 for the ICC and correlation, respectively. The image discretization method using fixed number of bins or fixed intervals gave a similar number of stable radiomic parameters (around 40%). The potentially standardizable factors introduced more variability into radiomic parameters than the non-standardizable ones with 56-98% and 43-58% instability rates, respectively. The highest variability was observed for voxel size (instability rate  >97% for both patient cohorts). Without standardization of CTP calculation factors none of the studied radiomic parameters were stable. After standardization with respect to non-standardizable factors ten radiomic parameters were stable for both patient cohorts after correction for inter-parameter correlations. Voxel size

  17. Stability of radiomic features in CT perfusion maps

    NASA Astrophysics Data System (ADS)

    Bogowicz, M.; Riesterer, O.; Bundschuh, R. A.; Veit-Haibach, P.; Hüllner, M.; Studer, G.; Stieb, S.; Glatz, S.; Pruschy, M.; Guckenberger, M.; Tanadini-Lang, S.

    2016-12-01

    This study aimed to identify a set of stable radiomic parameters in CT perfusion (CTP) maps with respect to CTP calculation factors and image discretization, as an input for future prognostic models for local tumor response to chemo-radiotherapy. Pre-treatment CTP images of eleven patients with oropharyngeal carcinoma and eleven patients with non-small cell lung cancer (NSCLC) were analyzed. 315 radiomic parameters were studied per perfusion map (blood volume, blood flow and mean transit time). Radiomics robustness was investigated regarding the potentially standardizable (image discretization method, Hounsfield unit (HU) threshold, voxel size and temporal resolution) and non-standardizable (artery contouring and noise threshold) perfusion calculation factors using the intraclass correlation (ICC). To gain added value for our model radiomic parameters correlated with tumor volume, a well-known predictive factor for local tumor response to chemo-radiotherapy, were excluded from the analysis. The remaining stable radiomic parameters were grouped according to inter-parameter Spearman correlations and for each group the parameter with the highest ICC was included in the final set. The acceptance level was 0.9 and 0.7 for the ICC and correlation, respectively. The image discretization method using fixed number of bins or fixed intervals gave a similar number of stable radiomic parameters (around 40%). The potentially standardizable factors introduced more variability into radiomic parameters than the non-standardizable ones with 56-98% and 43-58% instability rates, respectively. The highest variability was observed for voxel size (instability rate  >97% for both patient cohorts). Without standardization of CTP calculation factors none of the studied radiomic parameters were stable. After standardization with respect to non-standardizable factors ten radiomic parameters were stable for both patient cohorts after correction for inter-parameter correlations. Voxel size

  18. Recent developments and future prospects of SPECT myocardial perfusion imaging.

    PubMed

    Zaman, Maseeh Uz; Hashmi, Ibrahim; Fatima, Nosheen

    2010-10-01

    Myocardial perfusion SPECT imaging is the most commonly performed functional imaging for assessment of coronary artery disease. High diagnostic accuracy and incremental prognostic value are the major benefits while suboptimal spatial resolution and significant radiation exposure are the main limitations. Its ability to detect hemodynamic significance of lesions seen on multidetector CT angiogram (MDCTA) has paved the path for a successful marriage between anatomical and functional imaging modalities in the form of hybrid SPECT/MDCTA system. In recent years, there have been enormous efforts by industry and academia to develop new SPECT imaging systems with better sensitivity, resolution, compact design and new reconstruction algorithms with ability to improve image quality and resolution. Furthermore, expected arrival of Tc-99m-labeled deoxyglucose in next few years would further strengthen the role of SPECT in imaging hibernating myocardium. In view of these developments, it seems that SPECT would enjoy its pivotal role in spite of major threat to be replaced by fluorine-18-labeled positron emission tomography perfusion and glucose metabolism imaging agents.

  19. Myocardial Perfusion SPECT Imaging in Patients after Percutaneous Coronary Intervention.

    PubMed

    Georgoulias, Panagiotis; Valotassiou, Varvara; Tsougos, Ioannis; Demakopoulos, Nikolaos

    2010-05-01

    Coronary artery disease (CAD) is the most prevalent form of cardiovascular disease affecting about 13 million Americans, while more than one million percutaneous transluminal intervention (PCI) procedures are performed annually in the USA. The relative high occurrence of restenosis, despite stent implementation, seems to be the primary limitation of PCI. Over the last decades, single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), has proven an invaluable tool for the diagnosis of CAD and patients' risk stratification, providing useful information regarding the decision about revascularization and is well suited to assess patients after intervention. Information gained from post-intervention MPI is crucial to differentiate patients with angina from those with exo-cardiac chest pain syndromes, to assess peri-intervention myocardial damage, to predict-detect restenosis after PCI, to detect CAD progression in non-revascularized vessels, to evaluate the effects of intervention if required for occupational reasons and to evaluate patients' long-term prognosis. On the other hand, chest pain and exercise electrocardiography are largely unhelpful in identifying patients at risk after PCI.Although there are enough published data demonstrating the value of myocardial perfusion SPECT imaging in patients after PCI, there is still debate on whether or not these tests should be performed routinely.

  20. Thallium-201 perfusion imaging with atrial pacing or dipyridamole stress testing for evaluation of cardiac risk prior to nonvascular surgery

    SciTech Connect

    Stratmann, H.G.; Mark, A.L.; Williams, G.A. )

    1990-09-01

    Preoperative assessment of cardiac risk using thallium-201 scintigraphy and atrial pacing (n = 42) or dipyridamole stress testing (n = 35) was performed in 77 patients (mean age 65 +/- 7 years), who subsequently underwent elective nonvascular surgery. All patients were at low cardiac risk by clinical criteria; none could perform exercise stress testing due to physical limitations. ST depression consistent with ischemia occurred in 11 patients during atrial pacing and in 1 patient during dipyridamole stress testing (p less than 0.01). Nine patients had reversible perfusion defects with atrial pacing, and 10 patients with dipyridamole stress testing; fixed defects were present in 15 and 8 patients, respectively. Only one patient (fixed perfusion defect with atrial pacing, left main disease on coronary angiography) underwent preoperative coronary revascularization. Two patients subsequently had postoperative cardiac events. One patient (reversible perfusion defect with dipyridamole stress testing) experienced sudden death after a nonvascular procedure, while a second patient (normal thallium images with dipyridamole testing) had a nonfatal myocardial infarction. In patients having atrial pacing or dipyridamole stress testing, thallium-201 scans that are normal or show only a fixed perfusion defect confirm a low risk of cardiac complications following nonvascular surgery. The presence of a reversible perfusion defect does not preclude a postoperative course free of cardiac complications in patients at low cardiac risk by clinical criteria.

  1. Combined measurement of perfusion, venous oxygen saturation, and skeletal muscle T2* during reactive hyperemia in the leg

    PubMed Central

    2013-01-01

    Background The function of the peripheral microvascular may be interrogated by measuring perfusion, tissue oxygen concentration, or venous oxygen saturation (SvO2) recovery dynamics following induced ischemia. The purpose of this work is to develop and evaluate a magnetic resonance (MR) technique for simultaneous measurement of perfusion, SvO2, and skeletal muscle T2*. Methods Perfusion, Intravascular Venous Oxygen saturation, and T2* (PIVOT) is comprised of interleaved pulsed arterial spin labeling (PASL) and multi-echo gradient-recalled echo (GRE) sequences. During the PASL post-labeling delay, images are acquired with a multi-echo GRE to quantify SvO2 and T2* at a downstream slice location. Thus time-courses of perfusion, SvO2, and T2* are quantified simultaneously within a single scan. The new sequence was compared to separately measured PASL or multi-echo GRE data during reactive hyperemia in five young healthy subjects. To explore the impairment present in peripheral artery disease patients, five patients were evaluated with PIVOT. Results Comparison of PIVOT-derived data to the standard techniques shows that there was no significant bias in any of the time-course-derived metrics. Preliminary data show that PAD patients exhibited alterations in perfusion, SvO2, and T2* time-courses compared to young healthy subjects. Conclusion Simultaneous quantification of perfusion, SvO2, and T2* is possible with PIVOT. Kinetics of perfusion, SvO2, and T2* during reactive hyperemia may help to provide insight into the function of the peripheral microvasculature in patients with PAD. PMID:23958293

  2. Augmented myocardial perfusion reserve after coronary angioplasty quantified by positron emission tomography with H2(15)O

    SciTech Connect

    Walsh, M.N.; Geltman, E.M.; Steele, R.L.; Kenzora, J.L.; Ludbrook, P.A.; Sobel, B.E.; Bergmann, S.R. )

    1990-01-01

    Effects of coronary angioplasty on myocardial flow reserve have been difficult to characterize noninvasively because conventional imaging techniques cannot quantitate blood flow in absolute terms. The effects of coronary angioplasty on myocardial perfusion and perfusion reserve were delineated with positron emission tomography and oxygen-15-labeled water (H2(15)O) in 13 patients before and after single vessel angioplasty. In 11 patients, angioplasty was successful (minimal cross-sectional area increased from 0.60 +/- 0.59 to 3.45 +/- 1.09 mm2, p less than 0.001). In these patients, regional H2(15)O radioactivity (the ratio of nutritional perfusion in regions distal to the stenosis compared with regions supplied by angiographically normal arteries) at rest before angioplasty was 55 +/- 22% of peak myocardial radioactivity and did not increase significantly afterward (70 +/- 16%, p = NS). However, after administration of intravenous dipyridamole, hyperemic perfusion in regions distal to a stenosis averaged only 39 +/- 18% of peak myocardial counts before angioplasty, but increased to 66 +/- 22% after angioplasty (p less than 0.02). Perfusion reserve in the two patients in whom angioplasty was angiographically unsuccessful showed no change. Quantitative estimates of perfusion in absolute rather than relative terms were obtained with positron emission tomographic data from seven of the patients with successful angioplasty. At rest, perfusion in regions distal to a stenosis was not different from the values in regions supplied by normal coronary arteries (1.54 +/- 0.54 compared with 1.46 +/- 0.38 ml/g per min, p = NS).

  3. Long-term measurement of renal cortical and medullary tissue oxygenation and perfusion in unanesthetized sheep.

    PubMed

    Calzavacca, Paolo; Evans, Roger G; Bailey, Michael; Lankadeva, Yugeesh R; Bellomo, Rinaldo; May, Clive N

    2015-05-15

    The role of renal cortical and medullary hypoxia in the development of acute kidney injury is controversial, partly due to a lack of techniques for the long-term measurement of intrarenal oxygenation and perfusion in conscious animals. We have, therefore, developed a methodology to chronically implant combination probes to chronically measure renal cortical and medullary tissue perfusion and oxygen tension (tPO2) in conscious sheep and evaluated their responsiveness and reliability. A transit-time flow probe and a vascular occluder were surgically implanted on the left renal artery. At the same operation, dual fiber-optic probes, comprising a fluorescence optode to measure tPO2 and a laser-Doppler probe to assess tissue perfusion, were inserted into the renal cortex and medulla. In recovered conscious sheep (n = 8) breathing room air, mean 24-h cortical and medullary tPO2 were similar (31.4 ± 0.6 and 29.7 ± 0.7 mmHg, respectively). In the renal cortex and medulla, a 20% reduction in renal blood flow (RBF) decreased perfusion (14.6 ± 8.6 and 41.2 ± 8.5%, respectively) and oxygenation (48.1 ± 8.5 and 72.4 ± 8.5%, respectively), with greater decreases during a 50% reduction in RBF. At autopsy, minimal fibrosis was observed around the probes. In summary, we have developed a technique to chronically implant fiber-optic probes in the renal cortex and medulla for recording tissue perfusion and oxygenation over many days. In normal resting conscious sheep, cortical and medullary tPO2 were similar. The responses to and recovery from renal artery occlusion, together with the consistent measurements over a 24-h period, demonstrate the responsiveness and stability of the probes.

  4. Isolated heart perfusion according to Langendorff---still viable in the new millennium.

    PubMed

    Skrzypiec-Spring, Monika; Grotthus, Bartosz; Szelag, Adam; Schulz, Richard

    2007-01-01

    The isolated perfused mammalian heart preparation was established in 1897 by Oscar Langendorff. The method was developed on the basis of the isolated perfused frog heart established by Elias Cyon at the Carl Ludwig Institute of Physiology in Leipzig, Germany in 1866. Observations made using both methods at the end of the 19th and at the beginning of the 20th century led to important discoveries, forming the basis for our understanding of heart physiology. This included the role of temperature, oxygen and calcium ions for heart contractile function, the origin of cardiac electrical activity in the atrium, the negative chronotropic effect of vagus stimulation and the chemical transmission of impulses in the vagus nerve by acetylcholine. Langendorff himself demonstrated that the heart receives its nutrients and oxygen from blood via the coronary arteries and that cardiac mechanical function is reflected by changes in the coronary circulation. The method underwent many modifications but its general principle remains the same today. Blood, or more commonly crystalloid perfusates, are delivered into the heart through a cannula inserted in the ascending aorta, either at constant pressure or constant flow. Retrograde flow in the aorta closes the leaflets of the aortic valve and as a consequence, the entire perfusate enters the coronary arteries via the ostia at the aortic root. After passing through the coronary circulation the perfusate drains into the right atrium via the coronary sinus. The simplicity of the isolated mammalian heart preparation, the broad spectrum of measurements which can be done using this method, its high reproducibility and relatively low cost make it a very useful tool in modern cardiovascular and pharmacological research, in spite of a few shortcomings. In the last decade the method has brought many important advances in many areas including ischemia-reperfusion injury, cell-based therapy and donor heart preservation for transplant.

  5. Comparative studies on the toxicity of mercury, cadmium, and copper toward the isolated perfused rat liver.

    PubMed

    Strubelt, O; Kremer, J; Tilse, A; Keogh, J; Pentz, R; Younes, M

    1996-02-23

    The toxic effects of cadmium, mercury, and copper were compared over the over range 0.01, 0.03, and 0.1 mM using the isolated perfused rat liver preparation. All metals caused similar changes in various parameters used to describe general toxicity. Thus reductions in oxygen consumption, perfusion flow, and biliary secretion were found, while lactate dehydrogenase release into the perfusate, as well as liver weight, increased also in a dose-dependent fashion. Each metal caused similar magnitudes of changes and exerted similar potency. Measurement of other parameters indicating more specific injury revealed a number of differences. Although all metals reduced hepatic ATP concentration, mercury and cadmium were more potent than copper in this respect. Cadmium was the most potent at decreasing reduced glutathione levels. Mercury was most effective at increasing tissue calcium content, while copper was less so, and cadmium ineffective. Only copper significantly increased tissue malondialdehyde (MDA) content, while all metals increased its release into perfusate. Furthermore, whereas cadmium seemed the most potent metal in increasing MDA release, it was least efficacious, while copper was the most. Antioxidants such as superoxide dismutase, catalase, and Trolox C only reduced cadmium's influence on MDA in perfusate; however, they did not affect cadmium's ability to alter most other parameters of vitality. Albumin reversed the toxic effects of copper and mercury, but not cadmium. While metal-induced reductions in perfusion flow accounted for some of the toxic effects of the metals investigated, the results as a whole supported the suggestion that all metals exerted toxicity at the mitochondria, since ATP levels were reduced in a manner that could not be reproduced by perfusion flow reduction alone. Lipid peroxidation appears to play little role in determining toxicity induced by any of these metals. Furthermore, albumin may play an important physiological role in

  6. Electrical communication in branching arterial networks.

    PubMed

    Tran, Cam Ha T; Vigmond, Edward J; Goldman, Daniel; Plane, France; Welsh, Donald G

    2012-09-15

    Electrical communication and its role in blood flow regulation are built on an examination of charge movement in single, isolated vessels. How this process behaves in broader arterial networks remains unclear. This study examined the nature of electrical communication in arterial structures where vessel length and branching were varied. Analysis began with the deployment of an existing computational model expanded to form a variable range of vessel structures. Initial simulations revealed that focal endothelial stimulation generated electrical responses that conducted robustly along short unbranched vessels and to a lesser degree lengthened arteries or branching structures retaining a single branch point. These predictions matched functional observations from hamster mesenteric arteries and support the idea that an increased number of vascular cells attenuate conduction by augmenting electrical load. Expanding the virtual network to 31 branches revealed that electrical responses increasingly ascended from fifth- to first-order arteries when the number of stimulated distal vessels rose. This property enabled the vascular network to grade vasodilation and network perfusion as revealed through blood flow modeling. An elevation in endothelial-endothelial coupling resistance, akin to those in sepsis models, compromised this ascension of vasomotor/perfusion responses. A comparable change was not observed when the endothelium was focally disrupted to mimic disease states including atherosclerosis. In closing, this study highlights that vessel length and branching play a role in setting the conduction of electrical phenomenon along resistance arteries and within networks. It also emphasizes that modest changes in endothelial function can, under certain scenarios, impinge on network responsiveness and blood flow control.

  7. The use of thermography in early detection of tissue perfusion disorders in rats

    PubMed Central

    Łokaj, Marek; Falkowski, Aleksander; Prowans, Piotr

    2014-01-01

    Introduction Tissue perfusion disorders can be present in various diseases and progress in the form of arterial ischemia or venous stasis with accompanying local changes in temperature. Aim To use of thermography in the diagnostics of early periods of tissue perfusion disorders before the clinical symptoms occur. Material and methods Thirty-two male rats were used. After anesthesia the skin on lower limbs was shaved and femoral vessels of both sides were exposed. In 10 rats the left femoral artery was ligated, in 12 rats the left femoral vein was ligated and in the 10 remaining rats both left femoral vessels were ligated. Thermography of the limbs was performed before the vessels were ligated and after a period of 24 h. The pictures were taken every 5 s during 3 min. Before the measurement, the tissues were cooled down for 20 s with a 5°C water compress. The rate of temperature return to the limbs was evaluated. Results Statistically significant differences were observed after the 24-hour period on the thigh after the ligation of the vein, and on the shank and the foot after ligation of the artery. After the ligature of both vessels, statistically significant differences occurred immediately after their ligature within the thigh and shank and after 24 h on the foot. Conclusions The results show that cameras with an accuracy of 0.05°C can be used to detect tissue perfusion disorders. The special diagnostic value is the ability to detect perfusion disorders before clinical symptoms occur. PMID:25337154

  8. Effects of dipeptides administered to a perfused area of the skin in Angora goats.

    PubMed

    Pierzynowski, S G; Puchala, R; Sahlu, T

    1997-11-01

    The effect of dipeptide infusion on mohair growth of Angora goats was investigated using a skin perfusion technique. Six Angora wethers (average BW 32 +/- 2 kg) were implanted bilaterally with silicon catheters into the superficial branches of the deep circumflex iliac artery and to the deep circumflex iliac vein. For the first 14 d of the experiment, animals received infusions into the deep circumflex iliac arteries of either a mixture of Met-Leu and Lys-Leu (one side) or saline (other side). Infusion rates of amino acids were .72 mg/h Met-Leu and .72 mg/h Lys-Leu. The area of skin supplied by the deep circumflex iliac artery was approximately 300 cm2. An area of 150 cm2 within the perfused region was used to determine mohair growth. Two weeks after the cessation of infusions, perfused areas were shorn, and greasy and clean mohair production, staple length, and diameter were determined. Greasy and clean mohair production from the perfused region were increased by dipeptide infusion compared to the side infused with saline (1.91 vs 1.66 g, P < .05 and 1.56 vs 1.31 g, P < .04, respectively). No significant changes were observed in mohair diameter; however, staple length tended to increase as a result of dipeptide infusion (18.0 vs 16.1, P < .1). Decreased concentrations of Met, Cys, Lys, Phe, Val, Ileu, Leu, and Arg were observed in the venous blood taken from the deep circumflex iliac vein on the side infused with the amino acid mixture compared with blood taken from the saline side (P < .05). There were no treatment differences in triiodothyronine, thyroxine, or insulin concentrations in venous blood taken from the deep circumflex iliac vein. Direct skin infusion with dipeptide may have resulted in mobilization of amino acids for increased protein synthesis, or the infused dipeptides may have acted as growth promoters stimulating skin amino acid uptake and protein synthesis.

  9. Motion correction for improving the accuracy of dual-energy myocardial perfusion CT imaging

    NASA Astrophysics Data System (ADS)

    Pack, Jed D.; Yin, Zhye; Xiong, Guanglei; Mittal, Priya; Dunham, Simon; Elmore, Kimberly; Edic, Peter M.; Min, James K.

    2016-03-01

    Coronary Artery Disease (CAD) is the leading cause of death globally [1]. Modern cardiac computed tomography angiography (CCTA) is highly effective at identifying and assessing coronary blockages associated with CAD. The diagnostic value of this anatomical information can be substantially increased in combination with a non-invasive, low-dose, correlative, quantitative measure of blood supply to the myocardium. While CT perfusion has shown promise of providing such indications of ischemia, artifacts due to motion, beam hardening, and other factors confound clinical findings and can limit quantitative accuracy. In this paper, we investigate the impact of applying a novel motion correction algorithm to correct for motion in the myocardium. This motion compensation algorithm (originally designed to correct for the motion of the coronary arteries in order to improve CCTA images) has been shown to provide substantial improvements in both overall image quality and diagnostic accuracy of CCTA. We have adapted this technique for application beyond the coronary arteries and present an assessment of its impact on image quality and quantitative accuracy within the context of dual-energy CT perfusion imaging. We conclude that motion correction is a promising technique that can help foster the routine clinical use of dual-energy CT perfusion. When combined, the anatomical information of CCTA and the hemodynamic information from dual-energy CT perfusion should facilitate better clinical decisions about which patients would benefit from treatments such as stent placement, drug therapy, or surgery and help other patients avoid the risks and costs associated with unnecessary, invasive, diagnostic coronary angiography procedures.

  10. Permissive hypotension does not reduce regional organ perfusion compared to normotensive resuscitation: animal study with fluorescent microspheres

    PubMed Central

    2012-01-01

    Introduction The objective of this study was to investigate regional organ perfusion acutely following uncontrolled hemorrhage in an animal model that simulates a penetrating vascular injury and accounts for prehospital times in urban trauma. We set forth to determine if hypotensive resuscitation (permissive hypotension) would result in equivalent organ perfusion compared to normotensive resuscitation. Methods Twenty four (n=24) male rats randomized to 4 groups: Sham, No Fluid (NF), Permissive Hypotension (PH) (60% of baseline mean arterial pressure - MAP), Normotensive Resuscitation (NBP). Uncontrolled hemorrhage caused by a standardised injury to the abdominal aorta; MAP was monitored continuously and lactated Ringer’s was infused. Fluorimeter readings of regional blood flow of the brain, heart, lung, kidney, liver, and bowel were obtained at baseline and 85 minutes after hemorrhage, as well as, cardiac output, lactic acid, and laboratory tests; intra-abdominal blood loss was assessed. Analysis of variance was used for comparison. Results Intra-abdominal blood loss was higher in NBP group, as well as, lower hematocrit and hemoglobin levels. No statistical differences in perfusion of any organ between PH and NBP groups. No statistical difference in cardiac output between PH and NBP groups, as well as, in lactic acid levels between PH and NBP. NF group had significantly higher lactic acidosis and had significantly lower organ perfusion. Conclusions Hypotensive resuscitation causes less intra-abdominal bleeding than normotensive resuscitation and concurrently maintains equivalent organ perfusion. No fluid resuscitation reduces intra-abdominal bleeding but also significantly reduces organ perfusion. PMID:23531188

  11. A comparative analysis of the dependences of the hemodynamic parameters on changes in ROI's position in perfusion CT scans

    NASA Astrophysics Data System (ADS)

    Choi, Yong-Seok; Cho, Jae-Hwan; Namgung, Jang-Sun; Kim, Hyo-Jin; Yoon, Dae-Young; Lee, Han-Joo

    2013-05-01

    This study performed a comparative analysis of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and mean time-to-peak (TTP) obtained by changing the region of interest's (ROI) anatomical positions, during CT brain perfusion. We acquired axial source images of perfusion CT from 20 patients undergoing CT perfusion exams due to brain trauma. Subsequently, the CBV, CBF, MTT, and TTP values were calculated through data-processing of the perfusion CT images. The color scales for the CBV, CBF, MTT, and TTP maps were obtained using the image data. Anterior cerebral artery (ACA) was taken as the standard ROI for the calculations of the perfusion values. Differences in the hemodynamic average values were compared in a quantitative analysis by placing ROI and the dividing axial images into proximal, middle, and distal segments anatomically. By performing the qualitative analysis using a blind test, we observed changes in the sensory characteristics by using the color scales of the CBV, CBF, and MTT maps in the proximal, middle, and distal segments. According to the qualitative analysis, no differences were found in CBV, CBF, MTT, and TTP values of the proximal, middle, and distal segments and no changes were detected in the color scales of the the CBV, CBF, MTT, and TTP maps in the proximal, middle, and distal segments. We anticipate that the results of the study will useful in assessing brain trauma patients using by perfusion imaging.

  12. Fluid absorption in isolated perfused colonic crypts.

    PubMed Central

    Singh, S K; Binder, H J; Boron, W F; Geibel, J P

    1995-01-01

    A spatial segregation of ion transport processes between crypt and surface epithelial cells is well-accepted and integrated into physiological and pathophysiological paradigms of small and large intestinal function: Absorptive processes are believed to be located in surface (and villous) cells, whereas secretory processes are believed to be present in crypt cells. Validation of this model requires direct determination of fluid movement in intestinal crypts. This study describes the adaptation of techniques from renal tubule microperfusion to hand-dissect and perfuse single, isolated crypts from rat distal colon to measure directly fluid movement. Morphologic analyses of the isolated crypt preparation revealed no extraepithelial cellular elements derived from the lamina propria, including myofibroblasts. In the basal state, crypts exhibited net fluid absorption (mean net fluid movement = 0.34 +/- 0.01 nl.mm-1.min-1), which was Na+ and partially HCO3- dependent. Addition of 1 mM dibutyryl-cyclic AMP, 60 nM vasoactive intestinal peptide, or 0.1 mM acetylcholine to the bath (serosal) solution reversibly induced net fluid secretion (net fluid movement approximately -0.35 +/- 0.01 nl.mm-1.min-1). These observations permit speculation that absorption is a constitutive transport function in crypt cells and that secretion by crypt cells is regulated by one or more neurohumoral agonists that are released in situ from lamina propria cells. The functional, intact polarized crypt described here that both absorbs and secretes will permit future studies that dissect the mechanisms that govern fluid and electrolyte movement in the colonic crypt. Images PMID:7593625

  13. Coronary Artery Bypass Grafting

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Coronary Artery Bypass Grafting? Coronary artery bypass grafting (CABG) is ... bypass multiple coronary arteries during one surgery. Coronary Artery Bypass Grafting Figure A shows the location of ...

  14. Perfusion estimation using contrast enhanced three-dimensional subharmonic ultrasound imaging: an in vivo study

    PubMed Central

    Sridharan, Anush; Eisenbrey, John R.; Liu, Ji-Bin; Machado, Priscilla; Halldorsdottir, Valgerdur G.; Dave, Jaydev K.; Zhao, Hongjia; He, Yu; Park, Suhyun; Dianis, Scott; Wallace, Kirk; Thomenius, Kai E.; Forsberg, Flemming

    2013-01-01

    Objectives The ability to estimate tissue perfusion (in mL/min/g) in vivo using contrast-enhanced three-dimensional (3D) harmonic and subharmonic ultrasound imaging was investigated. Materials and Methods A Logiq 9 scanner (GE Healthcare, Milwaukee, WI) equipped with a 4D10L probe was modified to perform 3D harmonic imaging (HI; ftransmit = 5 MHz and freceive = 10 MHz) and subharmonic imaging (SHI; ftransmit= 5.8 MHz and freceive= 2.9 MHz). In vivo imaging was performed in the lower pole of both kidneys in five open-abdomen canines after injection of the ultrasound contrast agent (UCA) Definity (Lantheus Medical Imaging, N Billerica, MA). The canines received a 5 μL/kg bolus injection of Definity for HI and a 20 μL/kg bolus for SHI in triplicate for each kidney. Ultrasound data acquisition was started just prior to injection of UCA (in order to capture the wash-in) and continued until washout. A microvascular staining technique based on stable (non-radioactive) isotope-labeled microspheres (Biophysics Assay Laboratory Inc, Worcester, MA) was used to quantify the degree of perfusion in each kidney (the reference standard). Ligating a surgically exposed branch of the renal arteries induced lower perfusion rates. This was followed by additional contrast-enhanced imaging and microsphere injections to measure post-ligation perfusion. Slice data were extracted from the 3D ultrasound volumes and used to generate time-intensity curves off-line in the regions corresponding to the tissue samples used for microvascular staining. The mid-line plane was also selected from the 3D volume (as a quasi-2D image) and compared to the 3D imaging modes. Perfusion was estimated from the initial slope of the fractional blood volume uptake (for both HI and SHI) and compared to the reference standard using linear regression analysis. Results Both 3D HI and SHI were able to provide visualization of flow and, thus, perfusion in the kidneys. However, SHI provided near complete tissue

  15. The Mouse Isolated Perfused Kidney Technique.

    PubMed

    Czogalla, Jan; Schweda, Frank; Loffing, Johannes

    2016-11-17

    The mouse isolated perfused kidney (MIPK) is a technique for keeping a mouse kidney under ex vivo conditions perfused and functional for 1 hr. This is a prerequisite for studying the physiology of the isolated organ and for many innovative applications that may be possible in the future, including perfusion decellularization for kidney bioengineering or the administration of anti-rejection or genome-editing drugs in high doses to prime the kidney for transplantation. During the time of the perfusion, the kidney can be manipulated, renal function can be assessed, and various pharmaceuticals administered. After the procedure, the kidney can be transplanted or processed for molecular biology, biochemical analysis, or microscopy. This paper describes the perfusate and the surgical technique needed for the ex vivo perfusion of mouse kidneys. Details of the perfusion apparatus are given and data are presented showing the viability of the kidney's preparation: renal blood flow, vascular resistance, and urine data as functional, transmission electron micrographs of different nephron segments as morphological readouts, and western blots of transport proteins of different nephron segments as molecular readout.

  16. Arterial embolism

    MedlinePlus

    ... for embolization (especially to the brain) is mitral stenosis . Endocarditis (infection of the inside of the heart) can also cause arterial emboli. A common source for an embolus is from areas of hardening (atherosclerosis) in the aorta and other large blood vessels. These clots can ...

  17. Pulmonary artery intimal sarcoma: the role of ¹⁸F-fluorodeoxyglucose positron emission tomography in monitoring response to treatment.

    PubMed

    Ote, Enrique Leonardo P; Oriuchi, Noboru; Miyashita, Go; Paudyal, Bishnuhari; Ishikita, Tomohiro; Arisaka, Yukiko; Higuchi, Tetsuya; Hirato, Junko; Endo, Keigo

    2011-05-01

    We report the case of 58-year-old man with pulmonary artery intimal sarcoma. He initially presented with cough, right-sided chest pain, and shortness of breath. Although the diagnosis of pulmonary embolism had been considered, chest radiograph and pulmonary perfusion scintigraphy showed a mass in the right hilum and no perfusion in the right lung. (18)F-fluorodeoxyglucose positron emission computed tomography (FDGPET) showed increased FDG uptake in the mass obstructing the right pulmonary artery. Fine-needle biopsy revealed a pathological diagnosis of pulmonary artery intimal sarcoma. The patient was successfully treated with radiotherapy and adjuvant chemotherapy. FDG-PET was used for monitoring the response to therapy.

  18. Reversible Computing

    DTIC Science & Technology

    1980-02-01

    will have been introduced. 9. Reversible celular autemata We shall assume the reader to have some familiarity with the concept of cel- lular...10003 Mr. Kin B. Thcmpson 1 copy Technical Director Information Systems Divisia.i Naval Research Laboratory (OP-91T) Technical Information Division

  19. REVERSE OSMOSIS,

    DTIC Science & Technology

    acetate membranes. Mechanisms of the process and porous cellulose acetate membrane technology are briefly reviewed. Based on a general capillary...The reverse osmosis process is discussed with particular reference to systems involving aqueous solutions and Loeb-Sourirajan-type porous cellulose

  20. Cilio-retinal arterial circulation in central retinal vein occlusion.

    PubMed Central

    McLeod, D

    1975-01-01

    The hypothesis that an occlusion of the central retinal artery is an essential prerequisite for haemorrhage formation after central retinal vein obstruction has been investigated by examining the fundus changes in patients with a cilio-retinal arterial circulation; the findings are at variance with the 'combined occlusion hypothesis'. Comparisons were made between the pathological features in two retinal capillary beds with independent sources of arterial supply--namely, the central retinal and cilio-retinal arteries--but with an obstructed venous drainage channel common to both--namely, the central retinal vein. The importance of intraluminal pressure changes (as distinct from perfusion changes) in the causation of haemorrhages and oedema after venous occlusion is stressed, and the role of arterial disease in the pathogenesis of venous occlusions is distinguished from its role in determining the sequelae of such occlusions. Images PMID:1203235

  1. Functional recovery of hibernating myocardium after coronary bypass surgery: Does it coincide with improvement in perfusion

    SciTech Connect

    Takeishi, Y.; Tono-oka, I.; Kubota, I.; Ikeda, K.; Masakane, I.; Chiba, J.; Abe, S.; Tsuiki, K.; Komatani, A.; Yamaguchi, I. )

    1991-09-01

    To determine the relationship between functional recovery and improvement in perfusion after coronary artery bypass graft surgery (CABG), 49 patients were studied. Radionuclide angiography was performed before, 1 month after, and 6 to 12 months after CABG to evaluate regional wall motion. Exercise thallium-201 myocardial perfusion imaging was done before and 1 month after CABG to assess regional perfusion. Preoperative asynergy was observed in 108 segments, and 74 of them showed an improvement in wall motion 1 month after CABG (segment A). Sixty-six of these segments (89%) were associated with an improvement in perfusion. Eight segments that had not improved 1 month after CABG demonstrated a delayed recovery of wall motion 6 to 12 months after CABG (segment B). However, seven of eight segments (88%) already showed an improvement in perfusion 1 month after CABG. A total of 82 segments exhibited functional recovery after CABG and were considered hibernating segments. In the preoperative study segment B more frequently had areas of akinesis or dyskinesis than segment A (75% vs 34%, p less than 0.05). The mean percent thallium-201 uptake in segment B was lower than that in segment A (74% {plus minus} 9% vs 83% {plus minus} 8%, p less than 0.05). Functional recovery of hibernating myocardium usually coincided with an improvement in perfusion. However, delayed functional recovery after reperfusion was observed in some instances. Severe asynergy and severe thallium-201 defects were more frequently observed in these segments with delayed recovery. Hibernating myocardium might remain stunned during those recovery periods.

  2. Ischaemia-related cell damage in extracorporeal preserved tissue - new findings with a novel perfusion model.

    PubMed

    Taeger, Christian D; Müller-Seubert, Wibke; Horch, Raymund E; Präbst, Konstantin; Münch, Frank; Geppert, Carol I; Birkholz, Torsten; Dragu, Adrian

    2014-05-01

    Tissue undergoing free transfer in transplant or reconstructive surgery always is at high risk of ischaemia-related cell damage. This study aims at assessing different procedures using an extracorporeal perfusion and oxygenation system to investigate the expression of hypoxia inducible factor (HIF)-1-α as marker for hypoxia and of the pro-apoptotic protein Caspase-3 in skeletal muscle to elucidate potential improvements in tissue conservation. Twenty-four porcine rectus abdominis muscles were assigned to five different groups and examined after they had been extracorporeally preserved for 60 min. time. Group I was left untreated (control), group II was perfused with a cardioplegic solution, group III was flushed with 10 ml of a cardioplegic solution and then left untreated. Group IV and V were perfused and oxygenated with either an isotone crystalloid solution or a cardioplegic solution. Among others, immunohistochemistry (Caspase-3 and HIF-1-α) of muscle samples was performed. Furthermore, oxygen partial pressure in the perfusate at the arterial and venous branch was measured. Expression of Caspase-3 after 60 min. was reduced in all groups compared to the control group. Furthermore, all groups (except group III) expressed less HIF-1-α than the control group. Oxygenation leads to higher oxygen levels at the venous branch compared to groups without oxygenation. Using an extracorporeal perfusion and oxygenation system cell damage could be reduced as indicated by stabilized expressions of Caspase-3 and HIF-1-α for 60 min. of tissue preservation. Complete depletion of oxygen at the venous branch can be prevented by oxygenation of the perfusate with ambient air.

  3. Reproducibility and variability of very low dose hepatic perfusion CT in metastatic liver disease

    PubMed Central

    Topcuoğlu, Osman Melih; Karçaaltıncaba, Muşturay; Akata, Deniz; Özmen, Mustafa Nasuh

    2016-01-01

    PURPOSE We aimed to determine the intra- and interobserver agreement on the software analysis of very low dose hepatic perfusion CT (pCT). METHODS A total of 53 pCT examinations were obtained from 21 patients (16 men, 5 women; mean age, 60.4 years) with proven liver metastasis from various primary cancers. The pCT examinations were analyzed by two readers independently and perfusion parameters were noted for whole liver, whole metastasis, metastasis wall, and normal-looking liver (liver tissue without metastasis) in regions of interest (ROIs). Readers repeated the analysis after an interval of one month. Intra- and interobserver agreements were assessed with intraclass correlation coefficients (ICC) and Bland-Altman statistics. RESULTS The mean ICCs of all ROIs between readers were 0.91, 0.93, 0.86, 0.45, 0.53, and 0.66 for blood flow (BF), blood volume (BV), permeability, arterial liver perfusion (ALP), portal venous perfusion (PVP) and hepatic perfusion index (HPI), respectively. The mean ICCs of all ROIs between readings were 0.86, 0.91, 0.81, 0.53, 0.56, and 0.71 for BF, BV, permeability, ALP, PVP, and HPI, respectively. There was greater agreement on the parameters measured for the whole metastasis than on the parameters measured for the metastasis wall. The effective dose of all perfusion CT studies was 2.9 mSv. CONCLUSION There is greater intra- and interobserver agreement for BF and BV than for permeability, ALP, PVP, and HPI at very low dose hepatic pCT. Permeability, ALP, PVP, and HPI parameters cannot be used in clinical practice for hepatic pCT with an effective dose of 2.9 mSv. PMID:27759566

  4. Cerebral Perfusion and Gray Matter Changes Associated With Chemotherapy-Induced Peripheral Neuropathy

    PubMed Central

    Nudelman, Kelly N.H.; McDonald, Brenna C.; Wang, Yang; Smith, Dori J.; West, John D.; O'Neill, Darren P.; Zanville, Noah R.; Champion, Victoria L.; Schneider, Bryan P.

    2016-01-01

    Purpose To investigate the longitudinal relationship between chemotherapy-induced peripheral neuropathy (CIPN) symptoms (sx) and brain perfusion changes in patients with breast cancer. Interaction of CIPN-sx perfusion effects with known chemotherapy-associated gray matter density decrease was also assessed to elucidate the relationship between CIPN and previously reported cancer treatment–related brain structural changes. Methods Patients with breast cancer treated with (n = 24) or without (n = 23) chemotherapy underwent clinical examination and brain magnetic resonance imaging at the following three time points: before treatment (baseline), 1 month after treatment completion, and 1 year after the 1-month assessment. CIPN-sx were evaluated with the self-reported Functional Assessment of Cancer Therapy/Gynecologic Oncology Group–Neurotoxicity four-item sensory-specific scale. Perfusion and gray matter density were assessed using voxel-based pulsed arterial spin labeling and morphometric analyses and tested for association with CIPN-sx in the patients who received chemotherapy. Results Patients who received chemotherapy reported significantly increased CIPN-sx from baseline to 1 month, with partial recovery by 1 year (P < .001). CIPN-sx increase from baseline to 1 month was significantly greater for patients who received chemotherapy compared with those who did not (P = .001). At 1 month, neuroimaging showed that for the group that received chemotherapy, CIPN-sx were positively associated with cerebral perfusion in the right superior frontal gyrus and cingulate gyrus, regions associated with pain processing (P < .001). Longitudinal magnetic resonance imaging analysis in the group receiving chemotherapy indicated that CIPN-sx and associated perfusion changes from baseline to 1 month were also positively correlated with gray matter density change (P < .005). Conclusion Peripheral neuropathy symptoms after systemic chemotherapy for breast cancer are associated with

  5. In-vivo regional myocardial perfusion measurements in a porcine model by ECG-gated multislice computed tomography

    NASA Astrophysics Data System (ADS)

    Stantz, Keith M.; Liang, Yun; Meyer, Cristopher A.; Teague, Shawn; Stecker, Michael; Hutchins, Gary; McLennan, Gordon; Persohn, Scott

    2003-05-01

    Purpose: To evaluate whether functional multi-slice computed tomography (MSCT) can identify regional areas of normally perfused and ischemic myocardium in a porcine model. Material and Methods: Three out bred pigs, two of which had ameroids surgically implanted to constrict flow within the LAD and LCx coronary arteries, were injected with 25 mL of iopromide (Isovue) at a rate of 5 mL/second via the femoral or jugular vein. Sixty axial scans along the short axis of the heart was acquired on a 16-slice CT scanner (Philips MX8000-IDT) triggered at end-diastole of the cardiac cycle and acquiring an image within 270 msec. A second series of scans were taken after an intravenous injection of a vasodilator, 150 μg/kg/min of adenosine. ROIs were drawn around the myocardial tissue and the resulting time-density curves were used to extract perfusion values. Results: Determination of the myocardial perfusion and fractional blood volume implementing three different perfusion models. A 5-point averaging or 'smoothing' algorithm was employed to effectively filter the data due to its noisy nature. The (preliminary) average perfusion and fractional blood volume values over selected axial slices for the pig without an artificially induced stenosis were measured to be 84 +/- 22 mL/min/100g-tissue and 0.17 +/- 0.04 mL/g-tissue, the former is consistent with PET scan and EBCT results. The pig with a stenosis in the left LAD coronary artery showed a reduced global perfusion value -- 45 mL/min/100g-tissue. Correlations in regional perfusion values relative to the stenosis were weak. During the infusion of adenosine, averaged perfusion values for the three subjects increased by 46 (+/-45) percent, comparable to increases measured with PET. Conclusion: Quantifying global perfusion values using MDCT appear encouraging. Future work will focus resolving the systematic effects from noise due to signal fluctuation from the porcine tachyardia (80-93 BPM) and provide a more robust measurement

  6. Ventilation-perfusion imaging in pulmonary papillomatosis

    SciTech Connect

    Espinola, D.; Rupani, H.; Camargo, E.E.; Wagner, H.N. Jr.

    1981-11-01

    Three children with laryngeal papillomas involving the lungs had serial ventilation-perfusion scintigrams to assess results of therapy designed to reduce the bronchial involvement. Different imaging patterns were observed depending on size, number, and location of lesions. In early parenchymal involvement a ventilation-perfusion mismatch was seen. The initial and follow-up studies correlated well with clinical and radiographic findings. This noninvasive procedure is helpful in evaluating ventilatory and perfusion impairment in these patients as well as their response to treatment.

  7. Cochlear perfusion with a viscous fluid.

    PubMed

    Wang, Yi; Olson, Elizabeth S

    2016-07-01

    The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawn from basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner's membrane (RM), while in cochleae perfused with 0.125% and 0.25% HA RM was torn. Thus, the CAP threshold elevation was likely due to the broken RM, likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and

  8. [Results of emergency coronary artery bypass surgery after failed coronary angioplasty].

    PubMed

    Imazeki, T; Yokoyama, M; Murai, N; Kurimoto, Y; Sakurada, M; Simizu, Y

    1995-06-01

    In the past 7 years, 9 emergent or urgent coronary artery bypass operations after failed percutaneous transluminal angioplasty (PTCA) were performed among 947 (PTCA). Since the introduction of coronary perfusion catheter system for the support of coronary perfusion during PTCA we could reduce the number of emergent cases and these patients could be operated on semi-emergently and securely without endangering co-medical staffs in a hurry. It is also unnecessary to be on standby all the time when the PTCA is being undertaken. Two acute myocardial infarction cases died in the early phase of this study (operative mortality 22%) and none after the introduction of coronary perfusion system during PTCA.

  9. Regadenoson-stress myocardial CT perfusion and single-photon emission CT: rationale, design, and acquisition methods of a prospective, multicenter, multivendor comparison.

    PubMed

    Cury, Ricardo C; Kitt, Therese M; Feaheny, Kathleen; Akin, Jamie; George, Richard T

    2014-01-01

    Pharmacologic stress myocardial CT perfusion (CTP) has been reported to be a viable imaging modality for detection of myocardial ischemia compared with single-photon emission CT (SPECT) in several single-center studies. However, regadenoson-stress CTP has not previously been compared with SPECT in a multicenter, multivendor study. The rationale and design of a phase 2, randomized, cross-over study of regadenoson-stress myocardial perfusion imaging by CTP compared with SPECT are described herein. The study will be conducted at approximately 25 sites by using 6 different CT scanner models, including 64-, 128-, 256-, and 320-slice systems. Subjects with known/suspected coronary artery disease will be randomly assigned to 1 of 2 imaging procedure sequences; rest and regadenoson-stress SPECT on day 1, then regadenoson-stress CTP and rest CTP/coronary CT angiography (same acquisition) on day 2; or regadenoson-stress CTP and rest CTP/CT angiography on day 1, then rest and regadenoson-stress SPECT on day 2. The prespecified primary analysis examines the agreement rate between CTP and SPECT for detecting or excluding ischemia (≥2 or 0-1 reversible defects, respectively), as assessed by 3 independent blinded readers for each modality. Non-inferiority will be indicated if the lower boundary of the 95% CI for the agreement rate is within 0.15 of 0.78 (the observed agreement rate in the regadenoson pivotal trials). The protocol described herein will support the first evaluation of regadenoson-stress CTP by using multiple scanner types compared with SPECT.

  10. Color-Coded Digital Subtraction Angiography in the Management of a Rare Case of Middle Cerebral Artery Pure Arterial Malformation

    PubMed Central

    Feliciano, Caleb E; Pamias-Portalatin, Eva; Mendoza-Torres, Jorge; Effio, Euclides; Moran, Yadira; Rodriguez-Mercado, Rafael

    2014-01-01

    Summary The advent of flow dynamics and the recent availability of perfusion analysis software have provided new diagnostic tools and management possibilities for cerebrovascular patients. To this end, we provide an example of the use of color-coded angiography and its application in a rare case of a patient with a pure middle cerebral artery (MCA) malformation. A 42-year-old male chronic smoker was evaluated in the emergency room due to sudden onset of severe headache, nausea, vomiting and left-sided weakness. Head computed tomography revealed a right basal ganglia hemorrhage. Cerebral digital subtraction angiography (DSA) showed a right middle cerebral artery malformation consisting of convoluted and ectatic collateral vessels supplying the distal middle cerebral artery territory-M1 proximally occluded. An associated medial lenticulostriate artery aneurysm was found. Brain single-photon emission computed tomography with and without acetazolamide failed to show problems in vascular reserve that would indicate the need for flow augmentation. Twelve months after discharge, the patient recovered from the left-sided weakness and did not present any similar events. A follow-up DSA and perfusion study using color-coded perfusion analysis showed perforator aneurysm resolution and adequate, albeit delayed perfusion in the involved vascular territory. We propose a combined congenital and acquired mechanism involving M1 occlusion with secondary dysplastic changes in collateral supply to the distal MCA territory. Angiographic and cerebral perfusion work-up was used to exclude the need for flow augmentation. Nevertheless, the natural course of this lesion remains unclear and long-term follow-up is warranted. PMID:25496681

  11. Relation between perfusion defects on stress technetium-99m sestamibi SPECT scintigraphy and the location of a subsequent acute myocardial infarction.

    PubMed

    Miller, G L; Herman, S D; Heller, G V; Kalla, S; Levin, W A; Stillwell, K M; Travin, M I

    1996-07-01

    Although the presence of perfusion defects on stress myocardial perfusion imaging has been shown to correlate with future cardiac events, including acute myocardial infarction (AMI), it is unknown whether the location of the AMI can be predicted. Therefore, for 25 patients who had an AMI following a stress technetium-99m sestamibi single-photon emission computed tomographic (SPECT) imaging study and whose infarct location could be determined, the territory of infarction was correlated with the location of previous myocardial perfusion defects. A SPECT perfusion defect had been present in 24 patients (96%). The AMI occurred in territories that showed a reversible defect in 14 patients (56%), whereas 3 infarctions (12%) were in territories that revealed a fixed defect, and 8 infarctions (32%) were in territories that had not shown a defect on prior SPECT imaging. Whereas the incidence of infarction in territories with a reversible defect was highest at 14 of 26 (54%), the incidence of infarction in territories with a fixed defect was 3 of 7 (43%), and in territories with no defect was 8 of 42 (19%) (p = 0.011). Neither the time interval between SPECT imaging and infarction, nor the perfusion defect severity, was related to the correlation between perfusion defect and infarct location. Thus, although AMI occurs most often at the site of previous perfusion defects, reversible or fixed, a substantial percentage occur in territories without a perfusion defect. These findings suggest that abnormalities on SPECT perfusion imaging, although they serve as markers of significant coronary disease and increase the likelihood of infarction, do not always predict the exact location of infarction.

  12. Anomalous Origins of Coronary Arteries From the Pulmonary Artery: A Comprehensive Review of Literature and Surgical Options.

    PubMed

    Karimi, Mohsen; Kirshbom, Paul M

    2015-10-01

    Anomalous origins of coronary arteries from the pulmonary artery are rare malformations in which the coronary arteries originate from pulmonary artery sinuses or branches. The consequences are variable although, in most cases, these anomalies lead to severe coronary hypoperfusion and ventricular dysfunction. Surgical correction is indicated once the diagnosis is established due to high early mortality associated with the disease. In nearly all cases, the anomalous artery can be excised from its pulmonary origin, mobilized, and reimplanted directly into the ascending aorta using different surgical techniques. In rare circumstances, technical modifications must be used to restore a normal dual coronary perfusion. The emphasis of this article is to provide a collective review of surgical options published in the literature.

  13. Coronary artery occlusion after arterial switch operation in an asymptomatic 15-year-old boy

    PubMed Central

    Saini, Ashish P; Cyran, Stephen E; Ettinger, Steven M; Pauliks, Linda B

    2016-01-01

    A 15-year-old boy with transposition of the great arteries (TGA) and neonatal arterial switch operation (ASO) presented with complete occlusion of the left main coronary artery (LMCA). Intra-operatively, an intramural left coronary artery was identified. Therefore, since age 7 years he had a series of screening exercise stress tests. At 13 years old, he had 3 to 4 mm ST segment depression in the infero-lateral leads without symptoms. This progressed to 4.2 mm inferior ST segment depression at 15 years old with normal stress echocardiogram. Sestamibi myocardial perfusion scan and cardiac magnetic resonance imaging was inconclusive. Therefore, a coronary angiogram was obtained which showed complete occlusion of the LMCA with ample collateralization from the right coronary artery system. This was later confirmed on a computed tomogram (CT) angiogram, obtained in preparation of coronary artery bypass grafting. The case illustrates the difficulty of detecting coronary artery stenosis and occlusion in young patients with rich collateralization. Coronary CT angiogram and conventional angiography were the best imaging modalities to detect coronary anomalies in this adolescent with surgically corrected TGA. Screening CT angiography may be warranted for TGA patients, particularly for those with known coronary anomalies. PMID:27574609

  14. Dissociative Part-Dependent Resting-State Activity in Dissociative Identity Disorder: A Controlled fMRI Perfusion Study

    PubMed Central

    Schlumpf, Yolanda R.; Reinders, Antje A. T. S.; Nijenhuis, Ellert R. S.; Luechinger, Roger; van Osch, Matthias J. P.; Jäncke, Lutz

    2014-01-01

    Background In accordance with the Theory of Structural Dissociation of the Personality (TSDP), studies of dissociative identity disorder (DID) have documented that two prototypical dissociative subsystems of the personality, the “Emotional Part” (EP) and the “Apparently Normal Part” (ANP), have different biopsychosocial reactions to supraliminal and subliminal trauma-related cues and that these reactions cannot be mimicked by fantasy prone healthy controls nor by actors. Methods Arterial spin labeling perfusion MRI was used to test the hypotheses that ANP and EP in DID have different perfusion patterns in response to rest instructions, and that perfusion is different in actors who were instructed to simulate ANP and EP. In a follow-up study, regional cerebral blood flow of DID patients was compared with the activation pattern of healthy non-simulating controls. Results Compared to EP, ANP showed elevated perfusion in bilateral thalamus. Compared to ANP, EP had increased perfusion in the dorsomedial prefrontal cortex, primary somatosensory cortex, and motor-related areas. Perfusion patterns for simulated ANP and EP were different. Fitting their reported role-play strategies, the actors activated brain structures involved in visual mental imagery and empathizing feelings. The follow-up study demonstrated elevated perfusion in the left temporal lobe in DID patients, whereas non-simulating healthy controls had increased activity in areas which mediate the mental construction of past and future episodic events. Conclusion DID involves dissociative part-dependent resting-state differences. Compared to ANP, EP activated brain structures involved in self-referencing and sensorimotor actions more. Actors had different perfusion patterns compared to genuine ANP and EP. Comparisons of neural activity for individuals with DID and non-DID simulating controls suggest that the resting-state features of ANP and EP in DID are not due to imagination. The findings are

  15. Spiral CT During Selective Accessory Renal Artery Angiography: Assessment of Vascular Territory Before Aortic Stent-Grafting

    SciTech Connect

    Dorffner, Roland; Thurnher, Siegfried; Prokesch, Rupert; Youssefzadeh, Soraya; Hoelzenbein, Thomas; Lammer, Johannes

    1998-03-15

    We evaluated the vascular territory of accessory renal arteries in cases where the vessel might be overlapped by an aortic stent-graft. Spiral CT during selective accessory renal artery angiography was performed in four patients with abdominal aortic aneurysms (including one with a horseshoe kidney). The volume of the vascular territory of each renal artery was measured using a software program provided by the CT unit manufacturer. The supernumerary renal arteries perfused 32%, 37%, 15%, and 16% of the total renal mass, respectively. In two patients, stent-grafts were implanted, which resulted in occlusion of the supernumerary renal artery. The volume of the renal infarction was equal to the volume perfused by the artery as calculated before implantation of the stent-graft.The method proposed is accurate for estimating the size of the expected renal infarction. It might help to determine whether placement of a stent-graft is acceptable.

  16. Feasibility of Flat Panel Detector CT in Perfusion Assessment of Brain Arteriovenous Malformations: Initial Clinical Experience.

    PubMed

    Garcia, M; Okell, T W; Gloor, M; Chappell, M A; Jezzard, P; Bieri, O; Byrne, J V

    2017-02-16

    The different results from flat panel detector CT in various pathologies have provoked some discussion. Our aim was to assess the role of flat panel detector CT in brain arteriovenous malformations, which has not yet been assessed. Five patients with brain arteriovenous malformations were studied with flat panel detector CT, DSC-MR imaging, and vessel-encoded pseudocontinuous arterial spin-labeling. In glomerular brain arteriovenous malformations, perfusion was highest next to the brain arteriovenous malformation with decreasing values with increasing distance from the lesion. An inverse tendency was observed in the proliferative brain arteriovenous malformation. Flat panel detector CT, originally thought to measure blood volume, correlated more closely with arterial spin-labeling-CBF and DSC-CBF than with DSC-CBV. We conclude that flat panel detector CT perfusion depends on the time point chosen for data collection, which is triggered too early in these patients (ie, when contrast agent appears in the superior sagittal sinus after rapid shunting through the brain arteriovenous malformation). This finding, in combination with high data variability, makes flat panel detector CT inappropriate for perfusion assessment in brain arteriovenous malformations.

  17. Retinal research using the perfused mammalian eye.

    PubMed

    Niemeyer, G

    2001-05-01

    The effort to isolate and maintain alive in vitro an intact mammalian eye is rewarded by the full control provided over the arterial input and exclusion of systemic regulatory or compensatory mechanisms. Electrical recording of typical light-evoked field potentials from retina and optic nerve can be complemented by single-cell recording. Thus, light-induced electrical activity reflects the function of the retinal pigment epithelium, of the layers of the retina and of the ganglion cells or their axons. Retinal function in vitro is documented by electrophysiological and morphological methods revealing subtle features of retinal information processing as well as optic nerve signals that approach-at threshold stimulus intensity-the human psychophysical threshold. Such sensitivity of third-order retinal neurons is described for the first time. This well controlled in vitro preparation has been used successfully for biophysical, metabolic and pharmacological studies. Examples are provided that demonstrate the marked sensibility of the rod system to changes in glucose supply. Moreover, histochemical identification of glycogen stores revealed labeling of the second- and third-order neurons subserving the rod system, in addition to labeling of Müller (glial) cells in the cat retina. The glycogen content of the cat retina is augmented by prolonged anesthesia, largely depleted by ischemia after enucleation and enhanced by insulin. Pharmacological experiments using agonists and antagonists of putative retinal neurotransmitters are summarized and outlined using the muscarinic cholinergic agonist QNB as an example. Actions and uptake of the neuromodulator adenosine are presented in detail, including inhibitory effects on physiologically characterized ganglion cells. Neuronal effects of adenosine are distinguished from those resulting from vasodilatation and from glycogenolysis induced by the neuromodulator. To open the blood-retina barrier, a hyperosmotic challenge can be

  18. Perfusion deconvolution in DSC-MRI with dispersion-compliant bases.

    PubMed

    Pizzolato, Marco; Boutelier, Timothé; Deriche, Rachid

    2017-02-01

    Perfusion imaging of the brain via Dynamic Susceptibility Contrast MRI (DSC-MRI) allows tissue perfusion characterization by recovering the tissue impulse response function and scalar parameters such as the cerebral blood flow (CBF), blood volume (CBV), and mean transit time (MTT). However, the presence of bolus dispersion causes the data to reflect macrovascular properties, in addition to tissue perfusion. In this case, when performing deconvolution of the measured arterial and tissue concentration time-curves it is only possible to recover the effective, i.e. dispersed, response function and parameters. We introduce Dispersion-Compliant Bases (DCB) to represent the response function in the presence and absence of dispersion. We perform in silico and in vivo experiments, and show that DCB deconvolution outperforms oSVD and the state-of-the-art CPI+VTF techniques in the estimation of effective perfusion parameters, regardless of the presence and amount of dispersion. We also show that DCB deconvolution can be used as a pre-processing step to improve the estimation of dispersion-free parameters computed with CPI+VTF, which employs a model of the vascular transport function to characterize dispersion. Indeed, in silico results show a reduction of relative errors up to 50% for dispersion-free CBF and MTT. Moreover, the DCB method recovers effective response functions that comply with healthy and pathological scenarios, and offers the advantage of making no assumptions about the presence, amount, and nature of dispersion.

  19. Patient directed perfusion pressure on bypass, an analogy from electrical engineering--a new concept.

    PubMed

    Warwick, Richard; Poole, Robert; Palmer, Kenneth; Johnson, Ian; Poullis, Michael

    2010-03-01

    Organ ischemia, particularly mesenteric and renal, can occur despite a seemingly adequate perfusion flow and pressure during a period of cardiopulmonary bypass. The blood pressure to run bypass at remains a contentious issue. We present the concept that perfusion pressure during cardiopulmonary bypass should be patient specific, depending on an individual's resting pre-procedural blood pressure. Four simulated arterial traces with variable morphology, but identical systolic and diastolic blood pressures, were analyzed to calculate the medical mean, arithmetic mean, and root mean square of the blood pressure tracing. Using the standard medical formula for calculation of mean blood pressure, you can potentially underestimate perfusion pressure by 12 mmHg in a normotensive subject. The root mean square pressure calculates the equivalent non pulsatile pressure that will deliver the same hydraulic power to the circulation as its pulsatile equivalent. Patient specific perfusion pressures, calculated via root mean square may potentially help reduce the incidence of organ ischemia during cardiopulmonary bypass. Clinical trials are needed to confirm or refute this concept.

  20. Initial testing of a 3D printed perfusion phantom using digital subtraction angiography

    PubMed Central

    Khobragade, Parag; Ying, Leslie; Snyder, Kenneth; Wack, David; Bednarek, Daniel R.; Rudin, Stephen; Ionita, Ciprian N.

    2015-01-01

    Perfusion imaging is the most applied modality for the assessment of acute stroke. Parameters such as Cerebral Blood Flow (CBF), Cerebral Blood volume (CBV) and Mean Transit Time (MTT) are used to distinguish the tissue infarct core and ischemic penumbra. Due to lack of standardization these parameters vary significantly between vendors and software even when provided with the same data set. There is a critical need to standardize the systems and make them more reliable. We have designed a uniform phantom to test and verify the perfusion systems. We implemented a flow loop with different flow rates (250, 300, 350 ml/min) and injected the same amount of contrast. The images of the phantom were acquired using a Digital Angiographic system. Since this phantom is uniform, projection images obtained using DSA is sufficient for initial validation. To validate the phantom we measured the contrast concentration at three regions of interest (arterial input, venous output, perfused area) and derived time density curves (TDC). We then calculated the maximum slope, area under the TDCs and flow. The maximum slope calculations were linearly increasing with increase in flow rate, the area under the curve decreases with increase in flow rate. There was 25% error between the calculated flow and measured flow. The derived TDCs were clinically relevant and the calculated flow, maximum slope and areas under the curve were sensitive to the measured flow. We have created a systematic way to calibrate existing perfusion systems and assess their reliability. PMID:26633914

  1. Initial testing of a 3D printed perfusion phantom using digital subtraction angiography

    NASA Astrophysics Data System (ADS)

    Wood, Rachel P.; Khobragade, Parag; Ying, Leslie; Snyder, Kenneth; Wack, David; Bednarek, Daniel R.; Rudin, Stephen; Ionita, Ciprian N.

    2015-03-01

    Perfusion imaging is the most applied modality for the assessment of acute stroke. Parameters such as Cerebral Blood Flow (CBF), Cerebral Blood volume (CBV) and Mean Transit Time (MTT) are used to distinguish the tissue infarct core and ischemic penumbra. Due to lack of standardization these parameters vary significantly between vendors and software even when provided with the same data set. There is a critical need to standardize the systems and make them more reliable. We have designed a uniform phantom to test and verify the perfusion systems. We implemented a flow loop with different flow rates (250, 300, 350 ml/min) and injected the same amount of contrast. The images of the phantom were acquired using a Digital Angiographic system. Since this phantom is uniform, projection images obtained using DSA is sufficient for initial validation. To validate the phantom we measured the contrast concentration at three regions of interest (arterial input, venous output, perfused area) and derived time density curves (TDC). We then calculated the maximum slope, area under the TDCs and flow. The maximum slope calculations were linearly increasing with increase in flow rate, the area under the curve decreases with increase in flow rate. There was 25% error between the calculated flow and measured flow. The derived TDCs were clinically relevant and the calculated flow, maximum slope and areas under the curve were sensitive to the measured flow. We have created a systematic way to calibrate existing perfusion systems and assess their reliability.

  2. Patient Directed Perfusion Pressure on Bypass, an Analogy from Electrical Engineering—A New Concept

    PubMed Central

    Warwick, Richard; Poole, Robert; Palmer, Kenneth; Johnson, Ian; Poullis, Michael

    2010-01-01

    Abstract: Organ ischemia, particularly mesenteric and renal, can occur despite a seemingly adequate perfusion flow and pressure during a period of cardiopulmonary bypass. The blood pressure to run bypass at remains a contentious issue. We present the concept that perfusion pressure during cardiopulmonary bypass should be patient specific, depending on an individual’s resting pre-procedural blood pressure. Four simulated arterial traces with variable morphology, but identical systolic and diastolic blood pressures, were analyzed to calculate the medical mean, arithmetic mean, and root mean square of the blood pressure tracing. Using the standard medical formula for calculation of mean blood pressure, you can potentially underestimate perfusion pressure by 12 mmHg in a normotensive subject. The root mean square pressure calculates the equivalent non pulsatile pressure that will deliver the same hydraulic power to the circulation as its pulsatile equivalent. Patient specific perfusion pressures, calculated via root mean square may potentially help reduce the incidence of organ ischemia during cardiopulmonary bypass. Clinical trials are needed to confirm or refute this concept. PMID:20437793

  3. Assessment of Skeletal Muscle Perfusion using Contrast-Enhanced Ultrasonography: Technical Note

    PubMed Central

    Qureshi, Adnan I.; Saleem, Muhammad A.; Aytac, Emrah; Wallery, Shawn S.

    2017-01-01

    Background Intravenous contrast-enhanced ultrasonography is a recently developed technique for assessment of tissue perfusion, but has not been used for assessment of skeletal muscle perfusion. Methods We studied a 42-year-old woman in whom myonecrosis was suspected due to systemic vasculitis and ischemia. The biceps brachii (right) and quadriceps femoris (vastus medialis) on right-hand side and subsequently left-hand side were imaged. Intravenous bolus of activated perflutren lipid microspheres was injected and B-Flow color mode (brown color) was used within a selected region of interest to image the passage of contrast through muscle parenchyma throughout three cardiac cycles. Results Visual interpretation of muscle perfusion was performed based on the maximal intensity of contrast in the muscle, and the speed of contrast replenishment. No deficits were noted in the perfusion pattern. The arterial phase demonstrated stellate vascularity, centrifugal filling, and homogeneous hypervascularity at peak enhancement. Conclusions The bolus of contrast resulted in good signal persistence and satisfactory imaging for multiple muscle groups. PMID:28243350

  4. Optimization of flow-sensitive alternating inversion recovery (FAIR) for perfusion functional MRI of rodent brain.

    PubMed

    Nasrallah, Fatima A; Lee, Eugene L Q; Chuang, Kai-Hsiang

    2012-11-01

    Arterial spin labeling (ASL) MRI provides a noninvasive method to image perfusion, and has been applied to map neural activation in the brain. Although pulsed labeling methods have been widely used in humans, continuous ASL with a dedicated neck labeling coil is still the preferred method in rodent brain functional MRI (fMRI) to maximize the sensitivity and allow multislice acquisition. However, the additional hardware is not readily available and hence its application is limited. In this study, flow-sensitive alternating inversion recovery (FAIR) pulsed ASL was optimized for fMRI of rat brain. A practical challenge of FAIR is the suboptimal global inversion by the transmit coil of limited dimensions, which results in low effective labeling. By using a large volume transmit coil and proper positioning to optimize the body coverage, the perfusion signal was increased by 38.3% compared with positioning the brain at the isocenter. An additional 53.3% gain in signal was achieved using optimized repetition and inversion times compared with a long TR. Under electrical stimulation to the forepaws, a perfusion activation signal change of 63.7 ± 6.3% can be reliably detected in the primary somatosensory cortices using single slice or multislice echo planar imaging at 9.4 T. This demonstrates the potential of using pulsed ASL for multislice perfusion fMRI in functional and pharmacological applications in rat brain.

  5. Assessment of Tissue Perfusion Following Conventional Liposuction of Perforator-Based Abdominal Flaps

    PubMed Central

    Saçak, Bülent; Yalçın, Doğuş; Pilancı, Özgür; Tuncer, Fatma Betül; Çelebiler, Özhan

    2017-01-01

    Background The effect of liposuction on the perforators of the lower abdominal wall has been investigated in several studies. There are controversial results in the literature that have primarily demonstrated the number and patency of the perforators. The aim of this study was to determine the effect of liposuction on the perfusion of perforator-based abdominal flaps using a combined laser–Doppler spectrophotometer (O2C, Oxygen to See, LEA Medizintechnik). Methods Nine female patients undergoing classical abdominoplasty were included in the study. Perforators and the perfusion zones of the deep inferior epigastric artery flap were marked on the patient's abdominal wall. Flap perfusion was quantitatively assessed by measuring blood flow, velocity, capillary oxygen saturation, and relative amount of hemoglobin for each zone preoperatively, after tumescent solution infiltration, following elevation of the flap on a single perforator, and after deep and superficial liposuction, respectively. Results The measurements taken after elevation of the flap were not significantly different than measurements taken after the liposuction procedures. Conclusions The liposuction procedure does not significantly alter the perfusion of perforator-based abdominal flaps in the early period. The abdominal tissue discarded in a classic abdominoplasty operation can be raised as a perforator flap and has been demonstrated to be a unique model for clinical research. PMID:28352599

  6. Effect of venous injection site on accuracy of fast computed tomography (CT) estimation of myocardial perfusion

    SciTech Connect

    Bell, M.R.; Rumberger, J.A.; Lerman, L.O.; Behrenbeck, T.; Sheedy, P.F.; Ritman, E.L. )

    1990-02-26

    Measurement of myocardial perfusion with fast CT, using venous injections of contrast, underestimates high flow rates. Accounting for intramyocardial blood volume improves the accuracy of such measurements but the additional influence of different contrast injection sites is unknown. To examine this, eight closed chest anesthetized dogs (18-24 kg) underwent fast CT studies of regional myocardial perfusion which were compared to microspheres (M). Dilute iohexol (0.5 mL/kg) was injected over 2.5 seconds, via, in turn, the pulmonary artery (PA), proximal inferior vena cava (IVC) and femoral vein (FV) during CT scans performed at rest and after vasodilation with adenosine (M flow range: 52-399 mL/100 g/minute). Correlations made with M were not significantly different for PA vs IVC (n = 24), PA vs FV (n = 22) and IVC vs FV (n = 44). To determine the relative influence of injection site on accuracy of measurements above normal flow rates (> 150mL/100g/minute), CT flow (mL/100g/minute; mean {+-}SD) was compared to M. Thus, at normal flow, some CT overestimation of myocardial perfusion occurred with PA injections but FV or IVC injections provided for accurate measurements. At higher flow rates only PA and IVC injections enabled accurate CT measurements of perfusion. This may be related to differing transit kinetics of the input bolus of contrast.

  7. Vasomotor tone does not affect perfusion heterogeneity and gas exchange in normal primate lungs during normoxia

    NASA Technical Reports Server (NTRS)

    Glenny, R. W.; Robertson, H. T.; Hlastala, M. P.

    2000-01-01

    To determine whether vasoregulation is an important cause of pulmonary perfusion heterogeneity, we measured regional blood flow and gas exchange before and after giving prostacyclin (PGI(2)) to baboons. Four animals were anesthetized with ketamine and mechanically ventilated. Fluorescent microspheres were used to mark regional perfusion before and after PGI(2) infusion. The lungs were subsequently excised, dried inflated, and diced into approximately 2-cm(3) pieces (n = 1,208-1,629 per animal) with the spatial coordinates recorded for each piece. Blood flow to each piece was determined for each condition from the fluorescent signals. Blood flow heterogeneity did not change with PGI(2) infusion. Two other measures of spatial blood flow distribution, the fractal dimension and the spatial correlation, did not change with PGI(2) infusion. Alveolar-arterial O(2) differences did not change with PGI(2) infusion. We conclude that, in normal primate lungs during normoxia, vasomotor tone is not a significant cause of perfusion heterogeneity. Despite the heterogeneous distribution of blood flow, active regulation of regional perfusion is not required for efficient gas exchange.

  8. Vasectomy reversal.

    PubMed

    Belker, A M

    1987-02-01

    A vasovasostomy may be performed on an outpatient basis with local anesthesia, but also may be performed on an outpatient basis with epidural or general anesthesia. Local anesthesia is preferred by most of my patients, the majority of whom choose this technique. With proper preoperative and intraoperative sedation, patients sleep lightly through most of the procedure. Because of the length of time often required for bilateral microsurgical vasoepididymostomy, epidural or general anesthesia and overnight hospitalization are usually necessary. Factors influencing the preoperative choice for vasovasostomy or vasoepididymostomy in patients undergoing vasectomy reversal are considered. The preoperative planned choice of vasovasostomy or vasoepididymostomy for patients having vasectomy reversal described herein does not have the support of all urologists who regularly perform these procedures. My present approach has evolved as the data reported in Tables 1 and 2 have become available, but it may change as new information is evaluated. However, it offers a logical method for planning choices of anesthesia and inpatient or outpatient status for patients undergoing vasectomy reversal procedures.