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Sample records for reversed arterial perfusion

  1. The TRAP (twin reversed arterial perfusion) sequence - case presentation.

    PubMed

    Mărginean, Claudiu; Mărginean, Maria Oana; Mureşan, Daniel; Zahiu, LuminiŢa; Horváth, Emőke

    2016-01-01

    We present a particular case of TRAP (twin reversed arterial perfusion) syndrome, which has a very rarely association of the simultaneous existence of a rudimentary malformed heart and brain, and also other malformations like abdominal wall abnormality, absent bladder with present kidneys, and absence of the lungs, which appear only in a few cases on the receptor twin from this sequence, malformations incompatible with life. A Caucasian 26-year-old pregnant woman, at the first pregnancy, with a monochorionic-diamniotic pregnancy, 26 weeks of gestation was referred to our hospital, for polyhydramnios. The patient delivered a living female newborn, weighing 950 g, with an Apgar score of 2 at one minute - the donor fetus and a second female newborn with multiple malformations, no signs of life and who weighed 2300 g - the receptor fetus. The anatomopathological examination confirmed the TRAP sequence associated with severe facial dysmorphism, bilateral phocomelia and cardiac malformations (rudimentary hypoplastic, univentricular) and a vascular anastomosis between the two umbilical cords. Anemia and cardiac complications which can lead to cardiac failure, appear early during pregnancy and caused the death of the pumping twin. We emphasize that in our case of TRAP sequence, the ultrasound examination established the diagnosis of the syndrome with high accuracy. Therefore, we can conclude that the existence of a rudimentary heart and a vascular anastomosis between the two umbilical cords supports the apparition of TRAP sequence. The early diagnosis of this pathology, the observation of the pregnancy with the help of weekly ultrasounds and the intrauterine interventions can increase the survival chances of the donor fetus from the TRAP sequence. PMID:27151718

  2. [Role of twin reversed arterial perfusion syndrome in the development of fetus acardius].

    PubMed

    Nizyaeva, N V; Kostyukov, K V; Gladkova, K A; Kulikova, G V; Shchegolev, A I

    2016-01-01

    Monochorionic multiple pregnancy has a higher risk for obstetric complications, including those due to the development of twin-to-twin transfusion syndrome and reversed arterial perfusion syndrome (TRAP sequence). The latter occurs in 0.1% of all monochorionic pregnancies. The basis for TRAP sequence is a relationship between arterial and venous anastomoses from the appropriate placental areas, causing a recipient fetus to develop at the expense of a donor fetus. The presence of abnormal anastomoses is considered to be a main cause of acardia. The prognosis for a donor fetus is also unfavorable: the mortality rates in the absence of intrauterine correction are as high as 55%. PMID:27600783

  3. Special forms in twin pregnancy - ACARDIAC TWIN/ Twin reversed arterial perfusion (TRAP) sequence

    PubMed Central

    Anca, FA; Negru, A; Mihart, AE; Grigoriu, C; Bohîlțea, RE; Șerban, A

    2015-01-01

    Twin pregnancy generally represents a high-risk pregnancy, but monozygous twin pregnancy is a real challenge for the obstetrician due to the serious complications that may occur during its evolution. A very rare, severe complication of monozygous twin pregnancy, which we recently dealt with in the Obstetrics and Gynecology Department of the University Emergency Hospital Bucharest, was a monochorionic monoamniotic twin pregnancy with acardiac twin (TRAP). One of the fetuses (acardiac twin) presented a rudimentary unfunctional heart or even no heart at all, underdeveloped inferior part of the body and head, being transfused by the other fetus with a normal heart (pumping twin) by one superficial arterio-arterial anastomosis through which blood pumped backwards. The understanding of these cases is mandatory in order to offer maximum survival and heath chances to the viable fetus. Abbreviations: RFA = radiofrequency ablation, TRAP = reversed arterial perfusion PMID:26664482

  4. Twin Reversed Arterial Perfusion Sequence (TRAPS): An Illustrative Series of 13 Cases.

    PubMed

    Ruiz-Cordero, Roberto; Birusingh, Rhea J; Pelaez, Liset; Azouz, Michel; Rodriguez, Maria Matilde

    2016-01-01

    Twin reversed-arterial-perfusion sequence (TRAPS) is a rare and severe complication of monochorionic twin pregnancies. It usually occurs in the setting of monochorionic placentation, when the heart of a normal appearing twin serves as the pump for one or more dysmorphic twins whose head, thoracic organs, and upper extremities do not fully develop or do not develop at all and thus lack cardiac activity. Anomalous vascular placental architecture causes a shift in arterial flow towards the acardiac twin(s). The exact physiopathologic mechanisms that lead to this devastating phenomenon are not well known. We reviewed the maternal history and the surgical pathology reports of the fetuses and placentas of 13 different cases of TRAPS that were collected in a 23-year study period at a single institution. Herein we summarize the characteristic findings and illustrate specific mechanical feto-placental circulation issues that appear to be instrumental in the development of TRAPS. PMID:26847661

  5. Perfusion Assessment with the SPY System after Arterial Venous Reversal for Upper Extremity Ischemia

    PubMed Central

    2014-01-01

    Background: The timing and pattern of reperfusion following arterial- venous reversal (AVR) in patients with terminal ischemia of an upper extremity is not well understood. Methods: The current case series describes the timing and pattern of reperfusion observed in patients with terminal upper extremity ischemia who underwent AVR and repeated postoperative indocyanine green (ICG) angiography between 2004 and 2009. For all included patients, the SPY Near-Infrared Perfusion Assessment System permitted visualization of ICG-labeled blood flow for 60-second sampling periods at scheduled postoperative time points; outflow and rate and amplitude of inflow were objectively quantified with SPY-Q Analysis Toolkit image analysis software. Results: The series comprised 6 male patients (mean age, 46 years) who presented with upper extremity ischemia related to hypothenar hammer syndrome (n = 2), embolism with patent foramen ovale (n = 2), atherosclerosis (n = 1), and avulsion amputation of the thumb (n = 1); the patient with the avulsion amputation was diagnosed with thromboangiitis obliterans at the time of replantation. AVR was successful in all 6 patients. In 5 of 6 patients, ICG angiography and SPY-based visualization/quantification showed that venous outflow and arterial inflow gradually normalized (versus unaffected digits) between postoperative days (PODs) 0 and 3 and was maintained at long-term follow-up (≥3 months); for the patient who underwent thumb replantation, perfusion normalized between POD 3 and month 5 follow-up. Conclusions: AVR effectively reestablished blood flow in patients with terminal upper extremity ischemia. ICG angiography with SPY technology revealed that, in most cases, kinetic curves, timing, and patterns of perfusion gradually normalized over several PODs. PMID:25426368

  6. Twin Reversed Arterial Perfusion Syndrome (TRAP or Acardiac Twin)-A Case Report

    PubMed Central

    R., Kalyani; Bindra, Mandeep S.

    2014-01-01

    Twin reversed arterial perfusion (TRAP) syndrome is a rare condition (0.3:10,000 births) that occurs in monochorionic twin pregnancies, resulting in coexistence of a normal “pump” twin and an acardiac twin. The acardiac twin is dependent upon the normal twin to provide circulation by means of vascular anastomosis. Many of the bizarre defects are felt to be caused by low oxygen tension and this causes dramatic alteration in the twin fetal physiology and high prenatal mortality. The acardiac twin is a parasite, putting the pump fetus at risk of high output cardiac failure. Overall only 50% of pump twins survive. We present a case in a twenty year female, gravida two, para one, living one, full term normal pregnancy, ultrasound showed twin pregnancy. Following delivery, the first fetus survived only for one day and the second fetus showed features of TRAP syndrome. PMID:24596758

  7. Cardiac failure of the twin reversed arterial perfusion sequence pump twin during the first-trimester: a case report.

    PubMed

    Yang, X H; Xu, Y Q; Chen, X L; Zhao, S; Zhang, L; Pugash, D

    2016-01-01

    This article reports a case of prenatal ultrasonographic diagnosis and monitoring of the twin reversed arterial perfusion (TRAP) sequence pump twin and describes progression of the disorder to a severe heart failure and fetal death. Genetic analyses were also performed for both fetuses by array-based comparative genomic hybridization (aCGH). PMID:27328513

  8. Severe coronary tortuosity or myocardial bridging in patients with chest pain, normal coronary arteries, and reversible myocardial perfusion defects.

    PubMed

    Gaibazzi, Nicola; Rigo, Fausto; Reverberi, Claudio

    2011-10-01

    We reviewed patients with normal or near-normal coronary angiograms enrolled in the SPAM contrast stress echocardiographic diagnostic study in which 400 patients with chest pain syndrome of suspected cardiac origin with a clinical indication to coronary angiography were enrolled. Patients underwent dipyridamole contrast stress echocardiography (cSE) with sequential analysis of wall motion, myocardial perfusion, and Doppler coronary flow reserve before elective coronary angiography. Ninety-six patients with normal or near-normal epicardial coronary arteries were screened for the presence of 2 prespecified findings: severely tortuous coronary arteries and myocardial bridging. Patients were divided in 2 groups based on the presence (false-positive results, n = 37) or absence (true-negative results, n = 59) of reversible myocardial perfusion defects during cSE and compared for history and clinical and angiographic characteristics. Prevalence of severely tortuous coronary arteries (35% vs 5%, p <0.001) or myocardial bridging (13% vs 2%, p <0.05) was 7 times higher in patients who demonstrated reversible perfusion defects at cSE compared to those without reversible perfusion defects. No significant differences were found between the 2 groups for the main demographic variables and risk factors. Patients in the false-positive group more frequently had a history of effort angina (p <0.001) and ST-segment depression at treadmill electrocardiography (p <0.001). In conclusion, we hypothesize that patients with a positive myocardial perfusion finding at cSE but without obstructive epicardial coronary artery disease have a decreased myocardial blood flow reserve, which may be caused by a spectrum of causes other than obstructive coronary artery disease, among which severely tortuous coronary arteries/myocardial bridging may play a significant role. PMID:21784382

  9. Twin-reversed arterial perfusion sequence associated with decreased fetal cerebral vascular impedance

    PubMed Central

    Peyvandi, S.; Feldstein, V. A.; Hirose, S.; Rand, L.; Brook, M. M.; Moon-Grady, A. J.

    2015-01-01

    Objectives Twin-reversed arterial perfusion (TRAP) sequence affects 1% of monochorionic twin pregnancies and is caused by abnormal vascular connections between a pump twin and an acardiac mass. The effects of abnormal vascular connections on cerebral vasculature in the pump twin are unknown. We hypothesize that abnormal cerebral vascular impedance, as assessed by the pulsatility index (PI), is present in pump twins and that fetal intervention alters cerebral impedance. Methods Fetal echocardiograms performed between 2010 and 2013 in pregnancies diagnosed with TRAP (n = 19), recorded at presentation, and uncomplicated monochorionic twin pregnancies (controls, n = 18; 36 fetuses) were analyzed. In all subjects, the middle cerebral artery (MCA)-PI, combined cardiac output (CCO) and cardiothoracic ratio were calculated, and the values for cases and controls were compared. Results The mean gestational age at the time of echocardiography was 20 weeks in both groups. MCA-PI was lower in TRAP cases than in controls (1.55 (95%CI, 1.47–1.64) vs 1.74 (95% CI, 1.65–1.82), respectively; P = 0.004). CCO in TRAP cases was mildly elevated for gestational age (199.7 (95% CI, 138.4–261.1) mL/min) compared with that of controls (131.4 (95% CI, 102.2–160.7) mL/min). In six TRAP cases with a second echocardiogram available, the mean MCA-PI increased after intervention, from 1.5 (95%CI, 1.3–1.7) to 1.8 (95% CI, 1.4–2.2). Conclusions TRAP pump twins have lower cerebral vascular impedance than do controls, suggestive of a brain-sparing effect. MCA-PI appeared to increase in a small group of pump twins after intervention. These findings suggest a fetal cerebral autoregulatory response to a high cardiac output state that begins to change after fetal intervention. The long-termimplications for neurodevelopmental outcome warrant further study. PMID:25157457

  10. Septal and Anterior Reverse Mismatch of Myocardial Perfusion and Metabolism in Patients With Coronary Artery Disease and Left Bundle Branch Block

    PubMed Central

    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

    2015-01-01

    Abstract 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. PMID:25997045

  11. Specific complications of monochorionic twin pregnancies: twin-twin transfusion syndrome and twin reversed arterial perfusion sequence.

    PubMed

    Chalouhi, G E; Stirnemann, J J; Salomon, L J; Essaoui, M; Quibel, T; Ville, Y

    2010-12-01

    Monochorionic twins are subjected to specific complications which originate in either imbalance or abnormality of the single placenta serving two twins. This unequal placental sharing can cause complications including twin-twin transfusion syndrome (TTTS), twin anemia-polycythemia sequence (TAPS), selective intrauterine growth restriction or twin reversed arterial perfusion sequence (TRAP). Monochorionicity also makes the management of these specific complications as well as that of a severe malformation in one twin hazardous since the spontaneous death of one twin exposes the co-twin to a risk of exsanguination into the dead twin and its placenta. The latter is responsible for the death of the co-twin in up to 20% of the cases and in ischemic sequelae in about the same proportions in the survivors. Although the symptoms of all these complications are very different, the keystone of their management comes down to either surgical destruction of the inter-twin anastomoses on the chorionic plate when aiming at dual survival or selective and permanent occlusion of the cord of a severely affected twin aiming at protecting the normal co-twin. This can be best achieved by fetoscopic selective laser coagulation and bipolar forceps cord coagulation respectively. PMID:20855238

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

    PubMed

    Padma, Subramanyam; Sundaram, Palaniswamy Shanmuga

    2014-04-01

    Pediatric myocardial perfusion imaging (MPI) is not a routine investigation in an Indian setting due to under referrals and logistic problems. However, MPI is a frequently performed and established modality of investigation in adults for the identification of myocardial ischemia and viability. We report myocardial perfusion scintigraphy in a case of retropulmonary looping of left coronary artery in a baby after arterial switch surgery. Adenosine stress MPI revealed a large infarct involving anterior segment with moderate reversible ischemia of the lateral left ventricular segment. Coronary angiogram later confirmed left main coronary artery ostial occlusion with retrograde collateral supply from dilated right coronary artery. PMID:24761067

  13. Arterial Spin Labeling Measurements of Cerebral Perfusion Territories in Experimental Ischemic Stroke

    PubMed Central

    Leoni, Renata F.; Paiva, Fernando F.; Kang, Byeong-Teck; Henning, Erica C.; Nascimento, George C.; Tannús, Alberto; De Araújo, Dráulio B.; Silva, Afonso C.

    2016-01-01

    Collateral circulation, defined as the supplementary vascular network that maintains cerebral blood flow (CBF) when the main vessels fail, constitutes one important defense mechanism of the brain against ischemic stroke. In the present study, continuous arterial spin labeling (CASL) was used to quantify CBF and obtain perfusion territory maps of the major cerebral arteries in spontaneously hypertensive rats (SHR) and their normotensive Wistar-Kyoto (WKY) controls. Results show that both WKY and SHR have complementary, yet significantly asymmetric perfusion territories. Right or left dominances were observed in territories of the anterior (ACA), middle and posterior cerebral arteries, and the thalamic artery. Magnetic resonance angiography showed that some of the asymmetries were correlated with variations of the ACA. The leptomeningeal circulation perfusing the outer layers of the cortex was observed as well. Significant and permanent changes in perfusion territories were obtained after temporary occlusion of the right middle cerebral artery in both SHR and WKY, regardless of their particular dominance. However, animals with right dominance presented a larger volume change of the left perfusion territory (23 ± 9%) than animals with left dominance (7 ± 5%, P < 0.002). The data suggest that animals with contralesional dominance primarily safeguard local CBF values with small changes in contralesional perfusion territory, while animals with ipsilesional dominance show a reversal of dominance and a substantial increase in contralesional perfusion territory. These findings show the usefulness of CASL to probe the collateral circulation. PMID:24323754

  14. Clinical Neuroimaging Using Arterial Spin-Labeled Perfusion MRI

    PubMed Central

    Wolf, Ronald L.; Detre, John A.

    2007-01-01

    SUMMARY The two most common methods for measuring perfusion with MRI are based on dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL). Although clinical experience to date is much more extensive with DSC perfusion MRI, ASL methods offer several advantages. The primary advantages are that completely noninvasive absolute cerebral blood flow (CBF) measurements are possible with relative insensitivity to permeability, and that multiple repeated measurements can be obtained to evaluate one or more interventions or to perform perfusion-based functional MRI. ASL perfusion and perfusion-based fMRI methods have been applied in many clinical settings, including acute and chronic cerebrovascular disease, CNS neoplasms, epilepsy, aging and development, neurodegenerative disorders, and neuropsychiatric diseases. Recent technical advances have improved the sensitivity of ASL perfusion MRI, and increasing use is expected in the coming years. This review focuses on ASL perfusion MRI and applications in clinical neuroimaging. PMID:17599701

  15. Arterial Perfusion Imaging–Defined Subvolume of Intrahepatic Cancer

    SciTech Connect

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

    2014-05-01

    Purpose: To assess whether an increase in a subvolume of intrahepatic tumor with elevated arterial perfusion during radiation therapy (RT) predicts tumor progression after RT. Methods and Materials: Twenty patients with unresectable intrahepatic cancers undergoing RT were enrolled in a prospective, institutional review board–approved study. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed before RT (pre-RT), after delivering ∼60% of the planned dose (mid-RT) and 1 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 to 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 compared with the responsive tumors (P=.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% to 65%), whereas the progressive tumors had an increase of the subvolumes (median, 57%; range, −7% to 165%) (P=.003). Receiver operating characteristic analysis of the percentage change in the subvolume for predicting tumor progression post-RT had an area under the curve 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

  16. 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

  17. Regional Myocardial Perfusion Rates in Patients with Coronary Artery Disease

    PubMed Central

    Cannon, Paul J.; Dell, Ralph B.; Dwyer, Edward M.

    1972-01-01

    Regional myocardial perfusion rates were estimated from the myocardial washout of 133Xenon in 24 patients with heart disease whose coronary arteriograms were abnormal and 17 similar subjects whose coronary arteriograms were judged to be normal. Disappearance rates of 133Xe from multiple areas of the heart were monitored externally with a multiple-crystal scintillation camera after the isotope had been injected into a coronary artery and local myocardial perfusion rates were calculated by the Kety formula. The mean myocardial perfusion rates in the left ventricle exceeded those in the right ventricle or atrial regions in subjects without demonstrable coronary artery disease. In this group there was a significant lack of homogeneity of local perfusion rates in left ventricular myocardium; the mean coefficient of variation of left ventricular local perfusion rates was 15.8%. In the patients with radiographically demonstrable coronary artery disease, a variety of myocardial perfusion patterns were observed. Local capillary blood flow rates were depressed throughout the myocardium of patients with diffuse coronary disease but were subnormal only in discrete myocardial regions of others with localized occlusive disease. Local myocardial perfusion rates were similar to those found in the group with normal coronary arteriograms in patients with slight degrees of coronary disease and in those areas of myocardium distal to marked coronary constrictions or occlusions which were well supplied by collateral vessels. In subjects with right coronary disease, the mean right ventricular perfusion rates were significantly subnormal; in seven subjects of this group perfusion of the inferior left ventricle by a dominant right coronary artery was absent or depressed. The average mean left ventricular perfusion rate of 12 subjects with significant disease of two or more branches of the left coronary artery was significantly lower than that of the group with normal left coronary

  18. Localization of coronary artery disease with exercise electrocardiography: correlation with thallium-201 myocardial perfusion scanning

    SciTech Connect

    Dunn, R.F.; Freedman, B.; Bailey, I.K.; Uren, R.F.; Kelly, D.T.

    1981-11-01

    In 61 patients with single vessel coronary artery disease (70 percent or greater obstruction of luminal diameter in only one vessel) and no previous myocardial infarction, the sites of ischemic changes on 12 lead exercise electrocardiography and on thallium-201 myocardial perfusion scanning were related to the obstructed coronary artery. The site of exercise-induced S-T segment depression did not identify which coronary artery was obstructed. In the 37 patients with left anterior descending coronary artery disease S-T depression was most often seen in the inferior leads and leads V4 to V6, and in the 18 patients with right coronary artery disease and in the 6 patients with left circumflex artery disease S-T depression was most often seen in leads V5 and V6. Although S-T segment elevation was uncommon in most leads, it occurred in lead V1 or a VL, or both, in 51 percent of the patients with left anterior descending coronary artery disease. A reversible anterior defect on exercise thallium scanning correlated with left anterior descending coronary artery disease (probability (p) less than 0.0001) and a reversible inferior thallium defect correlated with right coronary or left circumflex artery disease (p less than 0.0001). In patients with single vessel disease, the site of S-T segment depression does not identify the obstructed coronary artery; S-T segment elevation in lead V1 or aVL, or both, identifies left anterior descending coronary artery disease; and the site of reversible perfusion defect on thallium scanning identifies the site of myocardial ischemia and the obstructed coronary artery.

  19. Coronary artery occlusion extends perfusion territory boundaries through microvascular collaterals.

    PubMed

    Cicutti, N; Rakusan, K; Downey, H F

    1994-01-01

    Simultaneous in vivo infusions of two different colored 10 microns microsphere suspensions into the left anterior descending (LAD; red spheres) and left circumflex (LCx; blue spheres) coronary arteries of nine anesthetized dogs identified a specific region of canine myocardium perfused by both arterial branches. Subsequently, the LAD was ligated and a third (green) set of micropheres was infused into the patent LCx artery. Analysis of 40 microns serial sections of tissue revealed interface zones with capillaries perfused by both arteries. The first zone, defined as the Interface Transistion Zone (ITZ) was formed by an intermingling of microvessels supplied by the parent arteries of the adjacent perfusion territories; it separated tissue containing only one or the other colored microspheres. Another zone, defined as the Boundary Watershed Zone was located within the ITZ and had capillaries containing both red and blue microspheres. The width of ITZ was 53377 +/- 817 microns (mean +/- SD), and the width of the BWZ was 3358 +/- 618 microns. Green microspheres, infused into the LCx following coronary occlusion were also found in the ITZ and BWZ. Furthermore, capillaries perfused exclusively by the LAD before occlusion (tissue with red but not blue microspheres) adjacent to the perfusion interface contained green microspheres as well as red/green aggregates, indicating lateral extension of the LCx perfusion territory. This extension of the LCx territory was quantitated by comparing the location at which densities of green microspheres or green/red aggregates decreased abruptly compared to the location of the original ITZ and BWZ boundaries, respectively. Results showed that LAD occlusion caused a 24% expansion of the ITZ and a 48% expansion of the BWZ. In addition, all expansions were significantly greater in subepicardial compared to subendocardial regions (p < 0.001). These results clearly demonstrate the capability of microvascular anastomoses in providing blood flow

  20. Cheek mucosa territories perfused by perforators from the facial artery.

    PubMed

    Coronel-Banda, M E; Serra-Renom, J M; Lorente, M; Larrea-Terán, W P

    2015-01-01

    The cutaneous areas perfused by the cutaneous perforators of the facial artery have been well defined. However, the oral mucosal areas perfused by perforators of the facial artery have not been described. We studied 20 hemifaces from 10 cadavers. Perforators between the branching off sites of the labial arteries larger than 0.5 mm were selected and their diameters were measured; the distance between their exit point over the facial artery and the branching-off point from the superior labial artery was also measured. The selected perforators were injected with 1 ml of diluted ink. Both labial arteries were ligated to limit the study to the mucosal perforators from the facial artery. Seventy-four perforators from 20 hemifaces were studied; the mean diameter was 0.58 mm and the mean number per artery was 3.7. The total stained area, a triangle-shaped zone on the cheek, was determined. The more constant perforators larger than 0.5 mm were localized next to the branching-off site of the superior labial artery. With this information, flaps based on the mucosal perforators from the facial artery could be designed. PMID:25218801

  1. 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

  2. Reversibility of hepatopulmonary syndrome evidenced by serial pulmonary perfusion scan.

    PubMed

    Shijo, H; Sasaki, H; Sakata, H; Kusuhara, H; Ueki, T; Okumura, M

    1993-02-01

    A patient with liver cirrhosis who exhibited marked hypoxemia is presented. An abnormal dilatation of intrapulmonary capillaries was evidenced by perfusion lung scan, contrast-enhanced echocardiography, and histological examinations of lungs. Serial perfusion lung scan disclosed that the radioisotope uptake by extrapulmonary organs was significantly increased and uptake by both lungs was significantly decreased during the state of severer hypoxemia. Shunt quantification method revealed that intrapulmonary right-to-left shunt ratio also paralleled the extent of hypoxemia. The pathophysiology of hepatopulmonary syndrome appeared to involve a reversible intrapulmonary vascular dilatation. The perfusion lung scan could semiquantitate the severity of intrapulmonary vascular dilatation and could offer the efficient method to follow their progress. PMID:8440418

  3. Extracorporeal membrane oxygenation with right axillary artery perfusion.

    PubMed

    Navia, José L; Atik, Fernando A; Beyer, Erik A; Ruda Vega, Pablo

    2005-06-01

    Extracorporeal membrane oxygenation can be instituted through various cannulation sites. This paper describes a technique for axillary artery cannulation for inflow perfusion in extracorporeal membrane oxygenation and discusses both potential advantages and limitations. Exposure of the artery was achieved through the deltoid-pectoral approach. Both direct cannulation and interposition graft cannulation are possible, but the latter is preferred. Advantages of axillary artery cannulation are related mainly to the establishment of "central" support with antegrade flow and excellent upper body oxygenation. It also affords chest closure after postcardiotomy shock, and easy control of any mediastinal bleeding. These cannulation sites may be options for the institution of venoarterial extracorporeal membrane oxygenation, especially in postcardiotomy and respiratory failure patients and in patients with significant peripheral vascular disease. PMID:15919341

  4. 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

  5. Right-sided reverse T composite arterial grafting to complete revascularization of the right coronary artery

    PubMed Central

    Aazami, Mathias H.; Abbasi-Teshnizi, Mohammad; Amini, Shahram; Lotfinejad, Nasim Sadat

    2014-01-01

    Complete arterial revascularization for the right coronary artery is underused mainly due to technical issues. Herein we report on a new approach for complete arterial revascularization of arterial revascularization for the right coronary artery branches. Complete arterial revascularization for the right coronary artery revascularization was performed in 8 patients using a reverse T composite arterial graft. None of the patients suffered perioperative myocardial infarction. All patients underwent noninvasive coronary imaging, displaying an early patency rate of 100%. Complete arterial arterial revascularization for the right coronary artery revascularization using a reverse T graft offers a new paradigm with enhanced technical flexibility in performing all arterial myocardial complete revascularizations in selected patients. PMID:25714223

  6. NCX 4016, a nitric oxide-releasing aspirin, modulates adrenergic vasoconstriction in the perfused rat tail artery

    PubMed Central

    Rossoni, Giuseppe; Manfredi, Barbara; Soldato, Piero Del; Berti, Ferruccio

    2002-01-01

    The ability of the nitric oxide (NO)-releasing aspirin, NCX 4016, to control vasoconstrictor responses induced by electrical field stimulation (TNS) or by exogenous norepinephrine (NE) was investigated in perfused rat tail artery with intact endothelium. NCX 4016 (25, 50 and 100 μM) dose-dependently antagonized the vasoconstriction caused by TNS (from 0.5 to 64 Hz) and by NE (from 0.01 to 10 μM). The vasorelaxant activity of NCX 4016 (100 μM) in NE-precontracted arteries was concomitant with a marked increase of tissue cyclic GMP (4.9 fold, P<0.001) and was significantly antagonized by the inhibitors of soluble guanylate cyclase, methylene blue and 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one. The effect of NCX 4016 was endothelium NO-independent since, in preparations perfused with NG-monomethyl-L-arginine (10 μM), this compound prevented the rise in basal perfusion pressure and reversed the accentuation of vasoconstrictor responses caused by NO synthase inhibition. Aspirin-moiety released by NCX 4016 inhibited the 6-keto-PGF1α formation without interfering with the vasorelaxant activity of NCX 4016, while aspirin (100 μM) was devoid of any activity against vasoconstriction induced by both TNS and NE in perfused rat tail artery. NCX 4016 moderated adrenergic vasoconstriction in perfused rat tail arteries by a direct donation of NO without involving the relaxant factors such as PGI2 and NO from endothelial cells. The results obtained with NCX 4016 in perfused rat tail artery bears some therapeutical potential in conditions associated with vascular smooth muscle hyperreactivity to adrenergic stimulation. PMID:12208780

  7. 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

  8. Clinical decision making with myocardial perfusion imaging in patients with known or suspected coronary artery disease.

    PubMed

    Cremer, Paul; Hachamovitch, Rory; Tamarappoo, Balaji

    2014-07-01

    Myocardial perfusion imaging (MPI) to diagnose coronary artery disease (CAD) is best performed in patients with intermediate pretest likelihood of disease; unfortunately, pretest likelihood is often overestimated, resulting in the inappropriate use of perfusion imaging. A good functional capacity often predicts low risk, and MPI for diagnosing CAD should be reserved for individuals with poor exercise capacity, abnormal resting electrocardiography, or an intermediate or high probability of CAD. With respect to anatomy-based testing, coronary CT angiography has a good negative predictive value, but stenosis severity correlates poorly with ischemia. Therefore decision making with respect to revascularization may be limited when a purely noninvasive anatomical test is used. Regarding perfusion imaging, the diagnostic accuracies of SPECT, PET, and cardiac magnetic resonance are similar, though fewer studies are available with cardiac magnetic resonance. PET coronary flow reserve may offer a negative predictive value sufficiently high to exclude severe CAD such that patients with mild to moderate reversible perfusion defects can forego invasive angiography. In addition, combined anatomical and perfusion-based imaging may eventually offer a definitive evaluation for diagnosing CAD, even in higher risk patients. Any remarkable findings on single-photon emission computed tomography and PET MPI studies are valuable for prognostication. Furthermore, assessment of myocardial blood flow with PET is particularly powerful for prognostication as it reflects the end result of many processes that lead to atherosclerosis. Decision making with respect to revascularization is limited for cardiac MRI and PET MPI. In contrast, retrospective radionuclide studies have identified an ischemic threshold, but randomized trials are needed. In patients with at least moderately reduced left ventricular systolic function, viable myocardium as assessed by PET or MRI, appears to identify patients

  9. [Novel strategy for thoracoabdomianl aortic aneurysm repair; intraoperative selective perfusion of the Adamkiewicz artery].

    PubMed

    Ohtsubo, S; Furukawa, K; Rikitake, K; Okazaki, Y; Sato, M; Natsuaki, M; Matsumoto, K; Kato, A; Kudo, S; Itoh, T

    2004-04-01

    We report our method for delineating the Adamkiewicz artery using multidetector row computed tomography (MDCT) with selective perfusion using a distal perfusion cannula that is clinically available for off-pump coronary artery bypass (OPCAB). The tip of a distal perfusion catheter (Medtronic Quickflow, Minneapolis) designed for OPCAB was applicable for selective perfusion of the segmental arteries. The femoro-femoral venoarterial bypass was branched off into selective perfusion of the segmental arteries, using an independent roller pump and heat exchanger. Our method of visualization of the Adamkiewicz artery was MDCT scanning with injection of contrast medium directly into the proximal descending aorta: namely, "CT during aortography". Lower descending aorta to abdominal aorta (the range involving the aneurysm) was scanned in a cephalad-to-caudal direction using a detector collimation of 4 x 1.25 mm with a table speed of 9.4 mm/sec, pitch of 6, and image thickness of 1.25 mm. All images were reviewed on a workstation to investigate the continuity between the Adamkiewicz artery and its proximal segmental artery with paging, mulitplanar reformation and curved planar reformation. Distal perfusion cannulae of 2.0 mm in diameter were inserted into the respective intercostal arteries. 4-0 polyethylene sutures were placed to tourniquet the catheters. Segmental arteries were perfused with total flow of approximately 80 ml/min at a circuit pressure of 120 mmHg. Reattachment of the ninth intercostal arteries related to the Adamkiewicz artery was carried out. A total of 6 consecutive 6 patients with thoracoabdominal aortic aneurysm (TAAA) have undergone graft replacement by the methods described, since April 2002. All patients survived surgery without any neurological complications. This method is expected to minimize the ischemic time of the spinal cord and attenuate the reperfusion injury. PMID:15071861

  10. 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.

  11. 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

  12. Technetium-99m labelled macroaggregated albumin arterial catheter perfusion scintigraphy: prediction of gastrointestinal toxicity in hepatic arterial chemotherapy.

    PubMed

    Pelosi, E; Masaneo, I; Clara, R; Valetto, M R; Bellò, M; Zanon, C; Chiappino, I; Grosso, M; Mussa, A; Bisi, G

    2000-06-01

    Gastrointestinal toxicity from hepatic arterial infusion (HAI) of floxuridine in patients with liver metastases is probably due to extrahepatic perfusion or to partial escape of the drug from first-pass liver extraction. The aim of this study was to verify the role of technetium-99m-labelled macroaggregated albumin (99mTc-MAA) arterial catheter perfusion scintigraphy at the beginning of each chemotherapy cycle in decreasing or preventing gastrointestinal toxicity. We studied 167 consecutive patients. On the basis of the scintigraphic follow-up and the presence or absence of an intrahepatic arteriovenous shunt (IHAVS), we classified our patients into the following groups: (1) FU+ hepatic distribution pattern (DP), comprising 29 patients with regular scintigraphic follow-up who showed the expected distribution pattern at each control or a distribution pattern with transient alterations (extrahepatic escape) promptly reversed by the replacement of the catheter. Among these 29 patients there was one case of gastrointestinal toxicity. (2) FU- hepatic DP, comprising 128 patients who were evaluated with 99mTc-MAA only at the beginning of the first chemotherapy cycle, showed the expected distribution pattern and underwent HAI with no further scintigraphic evaluation. Among these 128 patients there were 28 cases of gastrointestinal toxicity. (3) FU+ pulmonary DP, comprising three patients with abnormally elevated pulmonary uptake (higher than 5%) and with regular scintigraphic follow-up. There were two cases of gastrointestinal toxicity among these three patients. (4) FU- pulmonary DP, comprising seven patients with abnormally elevated pulmonary uptake and without regular scintigraphic follow-up. There were four cases of gastrointestinal toxicity among these seven patients. The incidence of toxicity was significantly higher in group FU- hepatic DP than in group FU+ hepatic DP (21.9% vs 3.4%, P<0.05). In both the FU+ pulmonary DP and FU- pulmonary DP groups, the incidence of

  13. Myocardial perfusion scintigraphy during maximal coronary artery vasodilation with adenosine

    SciTech Connect

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

    1991-05-21

    Pharmacologic coronary vasodilation as an adjunct to thallium-201 myocardial perfusion scintigraphy provides an important alternative form of stress that has been increasingly used in patients unable to perform an exercise stress test. Although dipyridamole has traditionally been used for this purpose, there are several compelling reasons why adenosine may be a preferable agent. First, dipyridamole acts by blocking the reuptake and transport of adenosine, which is the effective substance responsible for coronary vasodilation. Second, exogenous adenosine has a very short half-life (less than 2 seconds), which explains its very short duration of action as well as the brief, self-limiting duration of its side effects. Third, the adenosine infusion is controllable and may be increased or decreased as desired. Fourth, the coronary vasodilation induced by the doses of adenosine we recommend (140 micrograms/kg/min) may be more profound than that induced by the standard dipyridamole dose. Our experience to date, with nearly 1,000 patients studied, shows the adenosine thallium-201 test to be practical and well tolerated, with high sensitivity (87%) and specificity (94%) for detecting coronary artery disease.

  14. 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.

  15. 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.

  16. Challenges for non-invasive brain perfusion quantification using arterial spin labeling.

    PubMed

    Sousa, I; Santos, N; Sanches, J; Figueiredo, P

    2011-03-29

    Arterial Spin Labeling (ASL) sequences for perfusion Magnetic Resonance Imaging (MRI) have recently become available to be used in the clinical practice, offering a completely non-invasive technique for the quantitative evaluation of brain perfusion. Despite its great potential, ASL perfusion imaging still presents important methodological challenges before its incorporation in routine protocols. Specifically, in some pathological conditions in which the cerebrovascular dynamics is altered, the standard application of ASL may lead to measurement errors. In these cases, it would be possible to estimate perfusion, as well as arterial transit times, by collecting images at multiple time points and then fitting a mathematical model to the data. This approach can be optimized by selecting a set of optimal imaging time points and incorporating knowledge about the physiological distributions of the parameters into the model estimation procedures. In this study, we address the challenges that arise in the measurement of brain perfusion using PASL, due to variations in the arterial transit times, by estimating the errors produced using different types of acquisitions and proposing methods for minimizing such errors. We show by simulation that multiple inversion time ASL acquisitions are expected to reduce measurement errors relative to standard approaches. In data collected from a group of subjects, we further observed reduced inter-subject variability in perfusion measurements when using a multiple versus single inversion time acquisitions. Both measurement errors and variability were further reduced if optimized acquisition and analysis techniques were employed. PMID:24059574

  17. 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.

  18. Validating a local Arterial Input Function method for improved perfusion quantification in stroke

    PubMed Central

    Willats, Lisa; Christensen, Soren; K Ma, Henry; A Donnan, Geoffrey; Connelly, Alan; Calamante, Fernando

    2011-01-01

    In bolus-tracking perfusion magnetic resonance imaging (MRI), temporal dispersion of the contrast bolus due to stenosis or collateral supply presents a significant problem for accurate perfusion quantification in stroke. One means to reduce the associated perfusion errors is to deconvolve the bolus concentration time-course data with local Arterial Input Functions (AIFs) measured close to the capillary bed and downstream of the arterial abnormalities causing dispersion. Because the MRI voxel resolution precludes direct local AIF measurements, they must be extrapolated from the surrounding data. To date, there have been no published studies directly validating these local AIFs. We assess the effectiveness of local AIFs in reducing dispersion-induced perfusion error by measuring the residual dispersion remaining in the local AIF deconvolved perfusion maps. Two approaches to locating the local AIF voxels are assessed and compared with a global AIF deconvolution across 19 bolus-tracking data sets from patients with stroke. The local AIF methods reduced dispersion in the majority of data sets, suggesting more accurate perfusion quantification. Importantly, the validation inherently identifies potential areas for perfusion underestimation. This is valuable information for the identification of at-risk tissue and management of stroke patients. PMID:21629260

  19. 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.

  20. Abolished ventilation and perfusion of lung caused by blood clot in the left main bronchus: auto-downregulation of pulmonary arterial blood supply.

    PubMed

    Afzelius, P; Bergmann, A; Henriksen, J H

    2015-01-01

    It is generally assumed that the lungs possess arterial autoregulation associated with bronchial obstruction. A patient with pneumonia and congestive heart failure unexpectedly developed frequent haemoptysis. High-resolution CT and diagnostic CT were performed as well as ventilation/perfusion (V/Q) scintigraphy with single-photon emission CT (SPECT)/CT. V/Q SPECT/CT demonstrated abolished ventilation due to obstruction of the left main bronchus and markedly reduced perfusion of the entire left lung, a condition that was completely reversed after removal of a blood clot. We present the first pictorially documented case of hypoxia-induced pulmonary vasoconstriction and flow shift in a main pulmonary artery due to a complete intrinsic obstruction of the ipsilateral main bronchus. The condition is reversible, contingent on being relieved within a few days. PMID:26374773

  1. Optimization of arterial spin labeling MRI for quantitative tumor perfusion in a mouse xenograft model.

    PubMed

    Rajendran, Reshmi; Liang, Jieming; Tang, Mei Yee Annie; Henry, Brian; Chuang, Kai-Hsiang

    2015-08-01

    Perfusion is an important biomarker of tissue function and has been associated with tumor pathophysiology such as angiogenesis and hypoxia. Arterial spin labeling (ASL) MRI allows noninvasive and quantitative imaging of perfusion; however, the application in mouse xenograft tumor models has been challenging due to the low sensitivity and high perfusion heterogeneity. In this study, flow-sensitive alternating inversion recovery (FAIR) ASL was optimized for a mouse xenograft tumor. To assess the sensitivity and reliability for measuring low perfusion, the lumbar muscle was used as a reference region. By optimizing the number of averages and inversion times, muscle perfusion as low as 32.4 ± 4.8 (mean ± standard deviation) ml/100 g/min could be measured in 20 min at 7 T with a quantification error of 14.4 ± 9.1%. Applying the optimized protocol, heterogeneous perfusion ranging from 49.5 to 211.2 ml/100 g/min in a renal carcinoma was observed. To understand the relationship with tumor pathology, global and regional tumor perfusion was compared with histological staining of blood vessels (CD34), hypoxia (CAIX) and apoptosis (TUNEL). No correlation was observed when the global tumor perfusion was compared with these pathological parameters. Regional analysis shows that areas of high perfusion had low microvessel density, which was due to larger vessel area compared with areas of low perfusion. Nonetheless, these were not correlated with hypoxia or apoptosis. The results suggest that tumor perfusion may reflect certain aspect of angiogenesis, but its relationship with other pathologies needs further investigation. PMID:26104980

  2. 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.

  3. The effects of perfusion rate and NG-nitro-L-arginine methyl ester on cirazoline- and KCl-induced responses in the perfused mesenteric arterial bed of rats.

    PubMed Central

    Adeagbo, A. S.; Tabrizchi, R.; Triggle, C. R.

    1994-01-01

    1. The purpose of this study was to characterize the effect of NG-nitro-L-arginine methyl ester (L-NAME) on the perfusion rate/pressure relations, and on the pressor responses induced to cirazoline and KCl in isolated, perfused mesenteric arterial beds from normotensive and spontaneously hypertensive rats. 2. The basal perfusion pressure of arterial beds perfused with either physiological salt solution (PSS) or PSS containing 1% polyvinylpyrrolidone increased as the perfusion rate increased. L-NAME, in concentrations up to 100 microM, failed to alter the basal pressure regardless of the perfusion rate and viscosity; however, at 5 microM, it potentiated cirazoline-induced vasoconstriction at each of the perfusion rates. 3. L-NAME but not D-NAME caused a leftward shift of cirazoline concentration-response curves with a marked increase in the maximal response. The potentiating action of L-NAME was abolished in arterial beds perfused with a Ca(2+)-free physiological salt solution and also in beds denuded of endothelium by an infusion of distilled water for 5 min. 4. In endothelium-intact and -denuded preparations, L-NAME potentiated KCl pressor responses; the endothelium-independent potentiation of KCl pressor activity was stereospecific, time-independent and was not prevented by the presence of dexamethasone (0.5 microM) in the perfusion medium. However, L-NAME failed to potentiate vasoconstriction obtained to KCl in arterial beds denervated by cold storage (4-5 degrees C) for 2 days. 5. The absence of K+ in the perfusate did not inhibit the ability of L-NAME to potentiate alpha-adrenoceptor-mediated pressor responses, and nor did L-NAME inhibit KCl-induced vasodilatation in preconstricted arteries. It was thus concluded that L-NAME does not affect Na+/K(+)-ATPase activity.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7912152

  4. 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.

  5. Delayed Axillary Artery Occlusion after Reverse Total Shoulder Arthroplasty

    PubMed Central

    Heitmiller, Richard F.

    2016-01-01

    Axillary artery injury has been associated with shoulder dislocation and surgery. We describe a case of delayed axillary artery occlusion after reverse total shoulder arthroplasty. The injury was confirmed by Doppler and angiography and was treated with angioplasty and stenting. Early recognition and treatment of this injury are mandatory for patients' recovery. PMID:27555975

  6. Axillary Artery Access for Combined Endoaortic Balloon Occlusion and Perfusion During Robotic Mitral Valve Surgery.

    PubMed

    Ambur, Vishnu V; Kadakia, Sagar S; Taghavi, Sharven; Jayarajan, Senthil N; Kashem, Mohammed Abul; McCarthy, James; Shiose, Akira; Wheatley, Grayson H; Toyoda, Yoshiya; Guy, T Sloane

    2016-01-01

    We aimed to develop a method that provides an alternative cannulation site in robotic mitral valve surgery that allows simultaneous endo-occlusion and antegrade perfusion. A 71-year-old man with severe mitral regurgitation and history of coronary artery bypass grafting underwent totally endoscopic robotic mitral valve repair. A 23-mm endoreturn cannula was placed through a 10-mm graft that was sewn to the left axillary artery. An endoballoon was passed through the Dacron/cannula complex and into the ascending aorta. This complex was used for simultaneous antegrade perfusion, endoballoon occlusion, and antegrade cardioplegia. Completion transesophageal echocardiography showed no evidence of mitral regurgitation. The patient had an uneventful postoperative course and was doing well at his 2-month follow-up appointment. The left axillary artery is a viable option for simultaneous endoballoon occlusion, antegrade perfusion, and antegrade cardioplegia in robotic mitral valve surgery. This has the potential benefit of providing antegrade perfusion, which some studies have shown to be associated with a decreased risk of complications when compared with retrograde perfusion specifically in patients with severe peripheral vascular disease. PMID:27093272

  7. 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.

  8. Noninvasive testing of cerebral perfusion reserve prior to coronary artery bypass graft surgery

    SciTech Connect

    Levine, R.L.; Lagreze, H.L.; Berkoff, H.A.; Turnipseed, W.D.; Hanson, J.M.; Sunderland, J.J.; Nickles, R.J.; Rowe, B.R.

    1988-05-01

    Cerebral perfusion reserve testing using fluorine-18-fluoromethane and positron emission tomographic brain scanning to define cerebral blood flow abnormalities was performed in 5 patients being considered for combined coronary and carotid reconstructive surgery. Blood flow testing during normocapnia and following hypercapnia was utilized in these patients to determine the hemodynamic significance of known extracranial carotid artery occlusive lesions. Reserve diminution in 2 of these patients prompted combined surgery, whereas normal reserve values in the other 3 prompted coronary surgery alone. Results obtained in this preliminary series show how preoperative noninvasive testing of cerebral perfusion reserve adds to the diagnostic evaluation of patients with widespread vascular disease.

  9. Acute changes in liver tumour perfusion measured non-invasively with arterial spin labelling

    PubMed Central

    Johnson, S Peter; Ramasawmy, Rajiv; Campbell-Washburn, Adrienne E; Wells, Jack A; Robson, Mathew; Rajkumar, Vineeth; Lythgoe, Mark F; Pedley, R Barbara; Walker-Samuel, Simon

    2016-01-01

    Background: Non-invasive measures of tumour vascular perfusion are desirable, in order to assess response to vascular targeting (or modifying) therapies. In this study, hepatic arterial spin labelling (ASL) magnetic resonance imaging (MRI) was investigated to measure acute changes in perfusion of colorectal cancer in the liver, in response to vascular disruption therapy with OXi4503. Methods: SW1222 and LS174T tumours were established in the liver of MF1 nu/nu mice via intrasplenic injection. Perfusion and R2* MRI measurements were acquired with an Agilent 9.4T horizontal bore scanner, before and at 90 min after 40 mg kg−1 OXi4503. Results: A significant decrease in SW1222 tumour perfusion was observed (−43±33%, P<0.005). LS174T tumours had a significantly lower baseline level of perfusion. Intrinsic susceptibility MRI showed a significant increase in R2* in LS174T tumours (28±25%, P<0.05). An association was found between the change in tumour perfusion and the proximity to large vessels, with pre-treatment blood flow predictive of subsequent response. Histological evaluation confirmed the onset of necrosis and evidence of heterogeneous response between tumour deposits. Conclusions: Hepatic ASL-MRI can detect acute response to targeted tumour vascular disruption entirely non-invasively. Hepatic ASL of liver tumours has potential for use in a clinical setting. PMID:27031853

  10. Techniques for preserving vertebral artery perfusion during thoracic aortic stent grafting requiring aortic arch landing.

    PubMed

    Woo, Edward Y; Bavaria, Joseph E; Pochettino, Alberto; Gleason, Thomas G; Woo, Y Joseph; Velazquez, Omaida C; Carpenter, Jeffrey P; Cheung, Albert T; Fairman, Ronald M

    2006-01-01

    Thoracic endografting offers many advantages over open repair. However, delivery of the device can be difficult and may necessitate adjunctive procedures. We describe our techniques for preserving perfusion to the left subclavian artery despite endograft coverage to obtain a proximal seal zone. We reviewed our experience with the Talent thoracic stent graft (Medtronic, Santa Rosa, CA). From 1999 to 2003, 49 patients received this device (29 men, 20 women). Seventeen patients required adjunctive procedures to facilitate proximal graft placement. We performed left subclavian-to-left common carotid artery transposition (6), left common carotid-to-left subclavian artery bypass with ligation proximal to the vertebral artery (7), and left common carotid-to-left subclavian artery bypass with proximal coil embolization (4). Patients who had anatomy unfavorable to transposition or bypass with proximal ligation (large aneurysms or proximal vertebral artery origin) were treated with coil embolization of the proximal left subclavian artery in order to prevent subsequent type II endoleaks. Technical success rate of the carotid subclavian bypass was 100%. Patient follow-up ranged from 3 to 48 months with a mean of 12 months. Six patients had follow-up <6 months owing to recent graft placement. Primary patency was 100%. No neurologic events occurred during the procedure or upon follow-up. One patient had a transient chyle leak that spontaneously resolved in 24 hours. Another patient had a phrenic nerve paresis that resolved after 3 weeks. We believe that it is important to maintain patency of the vertebral artery specifically when a patent right vertebral system and an intact basilar artery is not demonstrated. Furthermore, we describe a novel technique of coil embolization of the proximal left subclavian artery in conjunction with left common carotid-to-left subclavian artery bypass. This circumvents the need for potentially hazardous mediastinal dissection and ligation of the

  11. Evidence for myocardial CT perfusion imaging in the diagnosis of hemodynamically significant coronary artery disease

    PubMed Central

    2015-01-01

    This editorial discusses a recent paper published in the August issue of Radiology about the diagnostic value of myocardial computer tomography (CT) perfusion imaging in the detection of hemodynamically significant coronary stenosis when compared to single-photon emission CT (SPECT) imaging based on a secondary analysis of CORE320 study. Three aspects including high diagnostic sensitivity of CT perfusion imaging, moderate specificity of SPECT imaging and lack of use of attenuation correction in SPECT imaging have been discussed with reference to the current literature, and some suggestions have been highlighted for future studies to improve the diagnostic performance of CT perfusion and SPECT imaging in the diagnostic evaluation of coronary artery disease. PMID:25774349

  12. Right axillary and femoral artery perfusion with mild hypothermia for aortic arch replacement

    PubMed Central

    2014-01-01

    Objectives Aortic arch replacement is associated with increased mortality and morbidity especially in acute type-A aortic dissection. Although hypothermic circulatory arrest with selective antegrade cerebral perfusion has been widely used because of its excellent cerebral protection, its optimal perfusion characteristics are unknown. The present study investigates clinical results obtained after perfusion method modification and temperature management during cardiopulmonary bypass (CPB). Methods Between July 2010 and August 2012, 16 consecutive adult patients (mean age 50.0 yr ± 14.1 yr, range 25 yr to 73 yr, 12 males, 4 females) who presented with acute Stanford type-A aortic dissection underwent aortic arch replacement (total arch, n = 11; hemiarch, n = 5) under mild hypothermia (31.1°C ± 1.5°C) with right axillary and femoral artery perfusion. Results The mean CPB time was 201 min ± 53 min, and the mean myocardial ischemic time was 140 min ± 42 min. The mean selective cerebral perfusion time was 80 min ± 16 min, and the mean lower-body circulatory arrest time was 20 min ± 13 min. No patient death occurred within 30 post-operative days. The following details were observed: new post-operative permanent neurologic deficit in 1 patient (6.3%), temporary neurologic deficit in 2 patients (12.5%), acute renal dysfunction (creatinine level > 230 umol/L) in 3 patients (18.8%) and mechanical ventilation > 72 h in 5 patients (31.2%). Conclusions Aortic arch replacement for acute type-A aortic dissection under mild hypothermia with right axillary and femoral artery perfusion could be safely performed in the patient cohort. PMID:24885031

  13. 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.

  14. Assessment of the myocardial perfusion pattern in patients with multivessel coronary artery disease

    SciTech Connect

    Iskandrian, A.S.; Hakki, A.H.; Segal, B.L.; Kane, S.A.; Amenta, A.

    1983-11-01

    A total of 42 symptomatic patients with coronary artery disease involving two or three vessels were studied using exercise thallium-201 myocardial scintigraphy. Qualitative analysis of the images predicted multivessel disease in 75% of the patients with two-vessel disease and in 82% of the patients with three-vessel disease. Quantitative analysis of the size of the perfusion defect indicated that approximately 40% of the left ventricular perimeter showed abnormal perfusion pattern during stress in these patients, and there was no significant difference in the size of the defect in patients with two-vessel disease or three-vessel disease (41 +/- 17% vs 42 +/- 14%, respectively, mean +/- SD). The exercise heart rate, exercise ECG response, and severity of narrowing did not correlate with the size of the perfusion defect. Patients with anterior infarction had larger defects in the distribution of the left anterior descending artery than those without infarction. Collaterals offered partial protection during exercise only when they were not jeopardized. This study confirms the value of qualitative analysis of exercise thallium-201 imaging in predicting multivessel disease, and describes a simple method of assessing the extent of perfusion abnormalities during stress in patients with multivessel disease. The results may be important in patient management and prognosis.

  15. 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. PMID:26119481

  16. Platelet-activating factor induces selective pulmonary arterial hyperreactivity in isolated perfused rabbit lungs.

    PubMed

    Ohar, J A; Waller, K S; Dahms, T E

    1993-07-01

    The role of vasoreactivity in PAF-induced pulmonary hypertension (PHT) was assessed in isolated, perfused rabbit lungs. We evaluated the steady-state pulmonary vascular response to five vasoconstrictors: PGF2 alpha, norepinephrine, angiotensin II, PAF, and KCl. Pulmonary arterial pressure and pulmonary vascular resistance (PVR) were significantly greater in lungs of rabbits treated with PAF for 28 days than in control rabbits in response to PGF2 alpha and norepinephrine. When resistance was partitioned by the vascular occlusion method, at baseline the vascular resistance was equally distributed between arterial and venous segments in both experimental groups. Arterial resistance accounted for approximately 76% of PVR during norepinephrine injection and 60% of PVR during PGF2 alpha injection in PAF-treated lungs. Whereas arterial resistance accounted for approximately 63% of PVR during norepinephrine injection and 52% of PVR during PGF2 alpha injection in control lungs, there was no significant difference in the response to angiotensin II, acute PAF, and KCl in lungs from chronic PAF-treated rabbits compared with responses in control rabbit lungs, though the pressor response to acute PAF tended to be blunted in PAF-treated lungs. Chronic PAF treatment results in enhanced pulmonary arterial reactivity to selected autacoids in isolated perfused lungs. PMID:8317792

  17. Combined anatomical and functional imaging using coronary CT angiography and myocardial perfusion SPECT in symptomatic adults with abnormal origin of a coronary artery.

    PubMed

    Uebleis, C; Groebner, M; von Ziegler, F; Becker, A; Rischpler, C; Tegtmeyer, R; Becker, C; Lehner, S; Haug, A R; Cumming, P; Bartenstein, P; Franz, W M; Hacker, M

    2012-10-01

    There has been a lack of standardized workup guidelines for patients with congenital abnormal origin of a coronary artery from the opposite sinus (ACAOS). We aimed to evaluate the use of cardiac hybrid imaging using multi-detector row CT (MDCT) for coronary CT angiography (Coronary CTA) and stress-rest myocardial perfusion SPECT (MPS) for comprehensive diagnosis of symptomatic adult patients with ACAOS. Seventeen symptomatic patients (12 men; 54 ± 13 years) presenting with ACAOS underwent coronary CTA and MPS. Imaging data were analyzed by conventional means, and with additional use of 3D image fusion to allocate stress induced perfusion defects (PD) to their supplying coronary arteries. An anomalous RCA arose from the left anterior sinus in eight patients, an abnormal origin from the right sinus was detected in nine patients (5 left coronary arteries, LCA and 4 LCx). Five of the 17 patients (29%) demonstrated a reversible PD in MPS. There was no correlation between the anatomical variants of ACAOS and the presence of myocardial ischemia. Image fusion enabled the allocation of reversible PD to the anomalous vessel in three patients (two cases in the RCA and the other in the LCA territory); PD in two patients were allocated to the territory of artery giving rise to the anomalies, rather than the anomalies themselves. In a small cohort of adult symptomatic patients with ACAOS anomaly there was no relation found between the specific anatomical variant and the appearance of stress induced myocardial ischemia using cardiac hybrid imaging. PMID:22147107

  18. 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.

  19. Non-Ischemic Perfusion Defects due to Delayed Arrival of Contrast Material on Stress Perfusion Cardiac Magnetic Resonance Imaging after Coronary Artery Bypass Graft Surgery

    PubMed Central

    Kim, Yeo Koon; Park, Sang Joon; Cheon, Gi Jeong; Lee, Whal; Chung, Jin Wook; Park, Jae Hyung

    2014-01-01

    Herein we report about the adenosine stress perfusion MR imaging findings of a 50-year-old man who exhibited two different perfusion defects resulting from two different mechanisms after a coronary artery bypass surgery. An invasive coronary angiography confirmed that one perfusion defect at the mid-anterior wall resulted from an ischemia due to graft stenosis. However, no stenosis was detected on the graft responsible for the mid-inferior wall showing the other perfusion defect. It was assumed that the perfusion defect at the mid-inferior wall resulted from delayed perfusion owing to the long pathway of the bypass graft. The semiquantitative analysis of corrected signal-time curves supported our speculation, demonstrating that the rest-to-stress ratio index of the maximal slope of the myocardial territory in question was similar to those of normal myocardium, whereas that of myocardium with the stenotic graft showed a typical ischemic pattern. A delayed perfusion during long graft pathway in a post-bypass graft patient can mimick a true perfusion defect on myocardial stress MR imaging. Radiologists should be aware of this knowledge to avoid misinterpretation of graft and myocardial status in post bypass surgery patients. PMID:24644408

  20. 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)

  1. Temporary arterial stenting in a full-house spaghetti wrist injury in a remote rural setting: benefit for hand perfusion or risk of increased morbidity?

    PubMed

    Bauer, Stefan; Savundra, James

    2013-01-01

    We report a case of temporary arterial plastic tube stenting of the ulnar and radial artery in a complete spaghetti wrist injury in a remote rural setting. Exploration in a specialist centre 18 h postinjury revealed that the tubes were clotted off with adjacent thrombi but hand perfusion was maintained. Intimal damage required vein grafting of both arteries 24 h postinjury. Hand perfusion was not compromised at follow-up. This case highlights that arterial hand perfusion can be maintained without the ulnar and radial artery. Arterial manipulation and tube insertion outside a specialist centre bears the risk of increased morbidity and potential microembolism and must therefore not be attempted. PMID:23505277

  2. Vertebral artery hypoplasia, posterior circulation infarction and relative hypoperfusion detected by perfusion magnetic resonance imaging semiquantitatively.

    PubMed

    Zhang, Dao Pei; Ma, Qian Kun; Zhang, Jie Wen; Zhang, Shu Ling; Lu, Gui Feng; Yin, Suo

    2016-09-15

    Vertebral artery hypoplasia (VAH) has been considered a risk factor of posterior circulation infarction (PCI), especially in the territory of the posterior inferior cerebellar artery (PICA). But whether VAH is an independent risk factor for PCI remains uncertain and how VAH participates in the evolvement of PCI is still not clear either. Therefore, this study aims to examine whether VAH is an independent risk factor for PCI and evaluate the effect of VAH on the cerebral perfusion in the territory of the PICA detected by perfusion magnetic resonance imaging (MRI) semiquantitatively. Both univariate and multivariate analyses showed that VAH, hypertension and smoking were more frequent in patients with PCI than in patients without PCI. Perfusion MRI analysis found that there were remarkable differences in the frequency of the relative cerebral blood flow (rCBF) value ≤0.85 and the relative time to peak (rTTP) values between VAH patients without PCI and non-VAH patients without PCI. Our results indicated that VAH may be an independent risk factor for PCI, especially in the presence of hypertension and smoking and that a relative hypoperfusion associates with VAH that may contribute to the evolvement of the infarction in the PICA territory. PMID:27538599

  3. Regional Reproducibility of Pulsed Arterial Spin Labeling Perfusion Imaging at 3T

    PubMed Central

    Yang, Wang; Saykin, Andrew J.; Pfeuffer, Josef; Lin, Chen; Mosier, Kristine M.; Shen, Li; Kim, Sungeun; Hutchins, Gary D.

    2010-01-01

    Arterial spin labeling (ASL) is a promising non-invasive magnetic resonance imaging (MRI) technique for measuring regional cerebral blood flow (rCBF) or perfusion in vivo. To evaluate the feasibility of ASL as a biomarker for clinical trials, it is important to examine test-retest reproducibility. We investigated both inter- and intra-session reproducibility of perfusion MRI using a pulsed ASL (PASL) sequence PICORE Q2TIPS with an echo-planar imaging (EPI) readout. Structural MRI regions of interest (ROIs) were extracted individually by automated parcellation and segmentation methods using FreeSurfer. These cortical and subcortical ROIs were used to assess regional perfusion stability. Our results indicated regional variability in grey matter rCBF. Although rCBF measurements were characterized by intersubject variation, our results also indicated relatively less within-subject variability estimated as within-subject standard deviation (SDW) (intersession SDW: 2.0 to 8.8; intrasession SDW: 2.8 to 9.6) and acceptable reliabilities as measured using intraclass correlation coefficient (ICC) (intersession ICC: 0.68 to 0.94; intrasession ICC: 0.66 to 0.95) for regional MRI perfusion measurements using the PICORE Q2TIPS technique. Overall, our findings suggest that PASL is a technique with good within and between session reproducibility. Further reproducibility studies in target populations relevant for specific clinical trials of neurovascular related agents will be important and the present results provide a framework for such assessments. PMID:20800097

  4. Effects of lung recruitment maneuvers on splanchnic organ perfusion during endotoxin-induced pulmonary arterial hypertension.

    PubMed

    Daudel, Fritz; Gorrasi, José; Bracht, Hendrik; Brandt, Sebastian; Krejci, Vladimir; Jakob, Stephan M; Takala, Jukka; Rothen, Hans Ulrich

    2010-11-01

    Lung recruitment maneuvers (RMs), used to reopen atelectatic lung units and to improve oxygenation during mechanical ventilation, may result in hemodynamic impairment. We hypothesize that pulmonary arterial hypertension aggravates the consequences of RMs in the splanchnic circulation. Twelve anesthetized pigs underwent laparotomy and prolonged postoperative ventilation. Systemic, regional, and organ blood flows were monitored. After 6 h (= baseline), a recruitment maneuver was performed with sustained inflation of the lungs. Thereafter, the pigs were randomly assigned to group C (control, n = 6) or group E with endotoxin-induced pulmonary arterial hypertension (n = 6). Endotoxemia resulted in a normotensive and hyperdynamic state and a deterioration of the oxygenation index by 33%. The RM was then repeated in both groups. Pulmonary artery pressure increased during lipopolysaccharide infusion from 17 ± 2 mmHg (mean ± SD) to 31 ± 10 mmHg and remained unchanged in controls (P < 0.05). During endotoxemia, RM decreased aortic pulse pressure from 37 ± 14 mmHg to 27 ± 13 mmHg (mean ± SD, P = 0.024). The blood flows of the renal artery, hepatic artery, celiac trunk, superior mesenteric artery, and portal vein decreased to 71% ± 21%, 69% ± 20%, 76% ± 16%, 79% ± 18%, and 81% ± 12%, respectively, of baseline flows before RM (P < 0.05 all). Organ perfusion of kidney cortex, kidney medulla, liver, and jejunal mucosa in group E decreased to 65% ± 19%, 77% ± 13%, 66% ± 26%, and 71% ± 12%, respectively, of baseline flows (P < 0.05 all). The corresponding recovery to at least 90% of baseline regional blood flow and organ perfusion lasted 1 to 5 min. Importantly, the decreases in regional blood flows and organ perfusion and the time to recovery of these flows did not differ from the controls. In conclusion, lipopolysaccharide-induced pulmonary arterial hypertension does not aggravate the RM-induced significant but short-lasting decreases in systemic, regional, and

  5. Reverse Radial Artery Flap Perforator Anatomy and Clinical Applications.

    PubMed

    White, Colin P; Steve, Anna K; Buchel, Edward W; Hayakawa, Thomas E; Morris, Steven F

    2016-09-01

    The pedicled reverse radial forearm flap is a well-known option for the treatment of a variety of soft tissue wounds including dorsal hand wounds. We document the number, emerging diameter, length from origin, course, and location of all perforators of the radial artery in a series of 6 fresh human cadavers after whole body lead oxide and gelatin injection to confirm and comprehensively document the anatomy of the radial artery perforators. This data provide an anatomic basis for a modification to the reversed radial forearm flap used to decrease venous congestion in the postoperative period. Two case reports are presented to provide clinical demonstration of the importance of this modification. PMID:26678105

  6. Validation of diffuse correlation spectroscopy for muscle blood flow with concurrent arterial spin labeled perfusion MRI

    NASA Astrophysics Data System (ADS)

    Yu, Guoqiang; Floyd, Thomas F.; Durduran, Turgut; Zhou, Chao; Wang, Jiongjiong; Detre, John A.; Yodh, Arjun G.

    2007-02-01

    Calf blood flow was measured simultaneously in healthy human subjects (n = 7) during cuff inflation and deflation using near-infrared diffuse correlation spectroscopy (DCS) and arterial spin labeled perfusion MRI (ASL-MRI). The DCS and ASL-MRI data exhibited highly correlated absolute and relative dynamic flow responses in each individual (p < 0.001). Peak flow variations during hyperemia were also significantly correlated, though more for relative (p = 0.003) than absolute (p = 0.016) flow. Repeated measurement variation was less than 8% for both modalities. The results provide much needed quantitative blood flow validation of the diffuse optical correlation method in humans.

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

    PubMed Central

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

    2005-01-01

    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 μM), an NO synthase inhibitor, had no effect on AHF and IOP. However, L-NAME (100 μM) completely reversed L-arginine's effect. AZ and SNP reduced the AHF and IOP dose-dependently. AZ at 100 nM, 1 and 10 μM 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 μM 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 μM), 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 μM), 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. PMID:15711584

  8. Four-dimensional Transcatheter Intra-arterial Perfusion MR Imaging Before and After Uterine Artery Embolization in the Rabbit VX2 Tumor Model

    PubMed Central

    Chung, Johnathan C.; Wang, Dingxin; Lewandowski, Robert J.; Tang, Richard; Chrisman, Howard B.; Vogelzang, Robert L.; Woloschak, Gayle E.; Larson, Andrew C.; Omary, Reed A.; Ryu, Robert K.

    2010-01-01

    Purpose To test the hypothesis that four-dimensional (4D) transcatheter intra-arterial perfusion (TRIP) MR imaging can measure uterine fibroid perfusion changes immediately before and after uterine artery embolization (UAE) in the rabbit VX2 tumor model. Materials and Methods Eight VX2 uterine tumors were grown in 6 rabbits. After positioning a catheter within the uterine artery, we performed 4D TRIP-MRI measurements with 3 mL injections of 2.5% gadopentetate dimeglumine. We used a dynamic 3D spoiled-GRE sequence with in vivo B1-field correction for improved accuracy during perfusion quantification. We performed UAE using 1 mL of gelatin microspheres (2×106 particles; diameter 40-120 μm). Two regions-of-interest were drawn within each tumor upon perfusion maps. Functional embolic endpoints were reported as the mean percent reduction in fibroid tumor perfusion. Measurements before and after UAE were compared using paired t-tests (α = 0.05). Results VX2 uterine tumor perfusion decreased significantly from 27.1 at baseline to 7.09 after UAE (mL/min/100 mL tissue, p < 0.0001). Overall perfusion reduction was 76.3% (95% CI: 66.3%-86.3%). Conclusion 4D TRIP MRI can objectively quantify uterine fibroid perfusion reductions during UAE in VX2 rabbits. This technique could be used clinically to potentially determine an optimal embolic endpoint with the long-term goals of improving UAE success rates and minimizing procedure-related ischemic pain. PMID:20432349

  9. Patterns of postictal cerebral perfusion in idiopathic generalized epilepsy: a multi-delay multi-parametric arterial spin labelling perfusion MRI study

    PubMed Central

    Chen, Guangxiang; Lei, Du; Ren, Jiechuan; Zuo, Panli; Suo, Xueling; Wang, Danny J. J.; Wang, Meiyun; Zhou, Dong; Gong, Qiyong

    2016-01-01

    The cerebral haemodynamic status of idiopathic generalized epilepsy (IGE) is a very complicated process. Little attention has been paid to cerebral blood flow (CBF) alterations in IGE detected by arterial spin labelling (ASL) perfusion magnetic resonance imaging (MRI). However, the selection of an optimal delay time is difficult for single-delay ASL. Multi-delay multi-parametric ASL perfusion MRI overcomes the limitations of single-delay ASL. We applied multi-delay multi-parametric ASL perfusion MRI to investigate the patterns of postictal cerebral perfusion in IGE patients with absence seizures. A total of 21 IGE patients with absence seizures and 24 healthy control subjects were enrolled. IGE patients exhibited prolonged arterial transit time (ATT) in the left superior temporal gyrus. The mean CBF of IGE patients was significantly increased in the left middle temporal gyrus, left parahippocampal gyrus and left fusiform gyrus. Prolonged ATT in the left superior temporal gyrus was negatively correlated with the age at onset in IGE patients. This study demonstrated that cortical dysfunction in the temporal lobe and fusiform gyrus may be related to epileptic activity in IGE patients with absence seizures. This information can play an important role in elucidating the pathophysiological mechanism of IGE from a cerebral haemodynamic perspective. PMID:27374369

  10. [Assessment of brain perfusion by arterial spin-labeling MR imaging in qusai-moyamoya disease associated with Graves' disease].

    PubMed

    Hayashi, Hisako; Kawatani, Masao; Ohta, Genrei; Kometani, Hiroshi; Ohshima, Yusei

    2014-07-01

    We report a case of 12-year-old girl with Graves' disease who had presented with deterioration in physical and scholastic performances since 10 years of age. She had an episode of atonic seizure and difficulty in speech. Brain MRI revealed formation of moyamoya vessels and a lesion suggestive of ischemic changes in the left frontal lobe. Because of uncontrollable thyrotoxicosis with anti-thyroid drug, she received a subtotal thyroidectomy. Two months later, she received a shunt operation between left superficial temporal artery and middle cerebral artery. The postoperative arterial spin-labeling MR imaging demonstrated an improvement of brain perfusion in left frontal lobe compared with the preoperative one, and provided comparable results of angiography and acetazolamide-challenged 150-gas PET. Thus, arterial spin-labeling MR imaging seems useful for follow-up evaluation of brain perfusion in qusai-moyamoya disease. PMID:25154228

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

    PubMed Central

    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

    2016-01-01

    Abstract 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. PMID:26844450

  12. 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)). PMID:26341268

  13. 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.

  14. DIVERGENCE BETWEEN ARTERIAL PERFUSION AND FATIGUE RESISTANCE IN SKELETAL MUSCLE IN THE METABOLIC SYNDROME

    PubMed Central

    Frisbee, Jefferson C.; Goodwill, Adam G.; Butcher, Joshua T.; Olfert, I. Mark

    2010-01-01

    The metabolic syndrome is associated with elevated peripheral vascular disease risk, characterized by mismatched blood flow delivery/distribution and local metabolism. The obese Zucker rat (OZR) model of the metabolic syndrome exhibits myriad vascular impairments, although their integrated impact on functional hyperemia remains unclear. In this study, arterial pressor responses and skeletal muscle perfusion were assessed in lean Zucker rats (LZR) and OZR during adrenergic stimulation (phenylephrine), challenge with thromboxane (U46619) and endothelium-dependent dilation (methacholine). OZR were hypertensive versus LZR, but this was abolished by adrenoreceptor blockade (phentolamine); pressor responses to U46619 were similar between strains and were abolished by blockade with the PGH2/TxA2 receptor antagonist, SQ-29548. Depressor reactivity to methacholine was impaired in OZR, but was improved by antioxidant treatment (TEMPOL). Across levels of metabolic demand, blood flow to in situ gastrocnemius muscle was restrained by adrenergic constriction in OZR, although this diminished with increased demand. O2 extraction, reduced in OZR vs. LZR across levels of metabolic demand, was improved by TEMPOL or SQ-29548; treatment with phentolamine did not impact extraction and neither TEMPOL nor SQ-29548 improved muscle blood flow in OZR. While VO2 and muscle performance were consistently reduced in OZR vs. LZR, treatment with all three agents improved outcomes, while treatment with individual agents was less effective. These results suggest that contributions of vascular dysfunction to perfusion, VO2 and muscle performance are spatially distinct, with adrenergic constriction impacting proximal resistance and endothelial dysfunction impacting distal microvessel-tissue exchange. Further, these data suggest that increasing skeletal muscle blood flow in OZR is not sufficient to improve performance, unless distal perfusion inhomogeneities are rectified. PMID:21123363

  15. Arterial Spin Labeling of Cerebral Perfusion Territories Using a Separate Labeling Coil

    PubMed Central

    Paiva, Fernando F.; Tannús, Alberto; Talagala, S. Lalith; Silva, Afonso C.

    2016-01-01

    Purpose To obtain cerebral perfusion territories of the left, the right and the posterior circulation in humans with high SNR and robust delineation. Materials and Methods CASL was implemented using a dedicated RF coil, positioned over the neck, to label the major cerebral feeding arteries in humans. Selective labeling was achieved by flow-driven adiabatic fast passage and by tilting the longitudinal labeling gradient about the Y-axis by θ=±60°. Results Mean CBF values in gray and white matter were 74±13 ml·100g−1·min−1 and 14±13 ml·100g−1·min−1, respectively (N=14). There were no signal differences between left and right hemispheres when θ=0° (P>0.19), indicating efficient labeling of both hemispheres. When θ=+60°, the signal in GM on the left hemisphere, 0.07±0.06%, was 92% lower than on the right hemisphere, 0.85±0.30% (P<10−9), while for θ=−60°, the signal in the right hemisphere, 0.16±0.13%, was 82% lower than on the contralateral side, 0.89±0.22% (P<10−10). Similar attenuations were obtained in white matter. Conclusions Clear delineation of the left and right cerebral perfusion territories was obtained, allowing discrimination of the anterior and posterior circulation in each hemisphere. PMID:18425844

  16. 3D GRASE PROPELLER: Improved Image Acquisition Technique for Arterial Spin Labeling Perfusion Imaging

    PubMed Central

    Tan, Huan; Hoge, W. Scott; Hamilton, Craig A.; Günther, Matthias; Kraft, Robert A.

    2014-01-01

    Arterial spin labeling (ASL) is a non-invasive technique that can quantitatively measure cerebral blood flow (CBF). While traditionally ASL employs 2D EPI or spiral acquisition trajectories, single-shot 3D GRASE is gaining popularity in ASL due to inherent SNR advantage and spatial coverage. However, a major limitation of 3D GRASE is through-plane blurring caused by T2 decay. A novel technique combining 3D GRASE and a PROPELLER trajectory (3DGP) is presented to minimize through-plane blurring without sacrificing perfusion sensitivity or increasing total scan time. Full brain perfusion images were acquired at a 3×3×5mm3 nominal voxel size with Q2TIPS-FAIR as the ASL preparation sequence. Data from 5 healthy subjects was acquired on a GE 1.5T scanner in less than 4 minutes per subject. While showing good agreement in CBF quantification with 3D GRASE, 3DGP demonstrated reduced through-plane blurring, improved anatomical details, high repeatability and robustness against motion, making it suitable for routine clinical use. PMID:21254211

  17. Perfusion-Weighted MRI Parameters for Prediction of Early Progressive Infarction in Middle Cerebral Artery Occlusion

    PubMed Central

    Kim, Hoon; Kim, Yerim; Kim, Young Woo; Kim, Seong Rim

    2016-01-01

    Objective Early progressive infarction (EPI) is frequently observed and related to poor functional outcome in patients with middle cerebral artery (MCA) infarction caused by MCA occlusion. We evaluated the perfusion parameters of magnetic resonance imaging (MRI) as a predictor of EPI. Methods We retrospectively analyzed patients with acute MCA territory infarction caused by MCA occlusion. EPI was defined as a National Institutes of Health Stroke Scale increment ≥2 points during 24 hours despite receiving standard treatment. Regional parameter ratios, such as cerebral blood flow and volume (rCBV) ratio (ipsilateral value/contralateral value) on perfusion MRI were analyzed to investigate the association with EPI. Results Sixty-four patients were enrolled in total. EPI was present in 18 (28%) subjects and all EPI occurred within 3 days after hospitalization. Diabetes mellitus, rCBV ratio and regional time to peak (rTTP) ratio showed statically significant differences in both groups. Multi-variate analysis indicated that history of diabetes mellitus [odds ratio (OR), 6.13; 95% confidence interval (CI), 1.55–24.24] and a low rCBV ratio (rCBV, <0.85; OR, 6.57; 95% CI, 1.4–30.27) was significantly correlated with EPI. Conclusion The incidence of EPI is considerable in patients with acute MCA territory infarction caused by MCA occlusion. We suggest that rCBV ratio is a useful neuro-imaging parameter to predict EPI. PMID:27446514

  18. Arterial Spin Labeling Perfusion Study in the Patients with Subacute Mild Traumatic Brain Injury

    PubMed Central

    Lin, Che-Ming; Tseng, Ying-Chi; Hsu, Hui-Ling; Chen, Chi-Jen; Chen, David Yen-Ting; Yan, Feng-Xian; Chiu, Wen-Ta

    2016-01-01

    Background This study uses a MRI technique, three-dimension pulse continuous arterial spin labeling (3D-PCASL), to measure the patient’s cerebral blood flow (CBF) at the subacute stage of mild traumatic brain injury (MTBI) in order to analyze the relationship between cerebral blood flow and neurocognitive deficits. Objective To provide the relationship between cortical CBF and neuropsychological dysfunction for the subacute MTBI patients. Methods After MTBI, perfusion MR imaging technique (3D-PCASL) measures the CBF of MTBI patients (n = 23) within 1 month and that of normal controls (n = 22) to determine the quantity and location of perfusion defect. The correlation between CBF abnormalities and cognitive deficits was elucidated by combining the results of the neuropsychological tests of the patients. Result We observed a substantial reduction in CBF in the bilateral frontal and left occipital cortex as compared with the normal persons. In addition, there were correlation between post concussive symptoms (including dizziness and simulator sickness) and CBF in the hypoperfused areas. The more severe symptom was correlated with higher CBF in bilateral frontal and left occipital lobes. Conclusion First, this study determined that despite no significant abnormality detected on conventional CT and MRI studies, hypoperfusion was observed in MTBI group using 3D-PCASL technique in subacute stage, which suggested that this approach may increase sensitivity to MTBI. Second, the correlation between CBF and the severity of post concussive symptoms suggested that changes in cerebral hemodynamics may play a role in pathophysiology underlies the symptoms. PMID:26871696

  19. Blood flow redistribution and ventilation-perfusion mismatch during embolic pulmonary arterial occlusion

    PubMed Central

    Burrowes, K. S.; Clark, A. R.; Tawhai, M. H.

    2011-01-01

    Acute pulmonary embolism causes redistribution of blood in the lung, which impairs ventilation/perfusion matching and gas exchange and can elevate pulmonary arterial pressure (PAP) by increasing pulmonary vascular resistance (PVR). An anatomically-based multi-scale model of the human pulmonary circulation was used to simulate pre- and post-occlusion flow, to study blood flow redistribution in the presence of an embolus, and to evaluate whether reduction in perfused vascular bed is sufficient to increase PAP to hypertensive levels, or whether other vasoconstrictive mechanisms are necessary. A model of oxygen transfer from air to blood was included to assess the impact of vascular occlusion on oxygen exchange. Emboli of 5, 7, and 10 mm radius were introduced to occlude increasing proportions of the vasculature. Blood flow redistribution was calculated after arterial occlusion, giving predictions of PAP, PVR, flow redistribution, and micro-circulatory flow dynamics. Because of the large flow reserve capacity (via both capillary recruitment and distension), approximately 55% of the vasculature was occluded before PAP reached clinically significant levels indicative of hypertension. In contrast, model predictions showed that even relatively low levels of occlusion could cause localized oxygen deficit. Flow preferentially redistributed to gravitationally non-dependent regions regardless of occlusion location, due to the greater potential for capillary recruitment in this region. Red blood cell transit times decreased below the minimum time for oxygen saturation (<0.25 s) and capillary pressures became high enough to initiate cell damage (which may result in edema) only after ~80% of the lung was occluded. PMID:22140626

  20. Cerebral Perfusion Measurements in Elderly with Hypertension Using Arterial Spin Labeling

    PubMed Central

    Mutsaerts, H. J. M. M.; van Dalen, J. W.; Heijtel, D. F. R.; Groot, P. F. C.; Majoie, C. B. L. M.; Petersen, E. T.; Richard, E.; Nederveen, A. J.

    2015-01-01

    Purpose The current study assesses the feasibility and value of crushed cerebral blood flow (CBFcrushed) and arterial transit time (ATT) estimations for large clinical imaging studies in elderly with hypertension. Material and Methods Two pseudo-continuous arterial spin labeling (ASL) scans with (CBFcrushed) and without flow crushers (CBFnon-crushed) were performed in 186 elderly with hypertension, from which CBF and ATT maps were calculated. Standard flow territory maps were subdivided into proximal, intermediate and distal flow territories, based on the measured ATT. The coefficient of variation (CV) and physiological correlations with age and gender were compared between the three perfusion parameters. Results There was no difference in CV between CBFcrushed and CBFnon-crushed (15–24%, p>0.4) but the CV of ATT (4–9%) was much smaller. The total gray matter correlations with age and gender were most significant with ATT (p = .016 and p<.001 respectively), in between for CBFcrushed (p = .206 and p = .019) and least significant for CBFnon-crushed (p = .236 and p = .100). Conclusion These data show the feasibility and added value of combined measurements of both crushed CBF and ATT for group analyses in elderly with hypertension. The obtained flow territories provide knowledge on vascular anatomy of elderly with hypertension and can be used in future studies to investigate regional vascular effects. PMID:26241897

  1. Comparison of Partial Volume Effects in Arterial and Venous Contrast Curves in CT Brain Perfusion Imaging

    PubMed Central

    Riordan, Alan J.; Bennink, Edwin; Dankbaar, Jan Willem; Viergever, Max A.; Velthuis, Birgitta K.; Smit, Ewoud J.; de Jong, Hugo W. A. M.

    2014-01-01

    Purpose In brain CT perfusion (CTP), the arterial contrast bolus is scaled to have the same area under the curve (AUC) as the venous outflow to correct for partial volume effects (PVE). This scaling is based on the assumption that large veins are unaffected by PVE. Measurement of the internal carotid artery (ICA), usually unaffected by PVE due to its large diameter, may avoid the need for partial volume correction. The aims of this work are to examine i) the assumptions behind PVE correction and ii) the potential of selecting the ICA obviating correction for PVE. Methods The AUC of the ICA and sagittal sinus were measured in CTP datasets from 52 patients. The AUCs were determined by i) using commercial CTP software based on a Gaussian curve-fitting to the time attenuation curve, and ii) by simple integration of the time attenuation curve over a time interval. In addition, frames acquired up to 3 minutes after first bolus passage were used to examine the ratio of arterial and venous enhancement. The impact of selecting the ICA without PVE correction was illustrated by reporting cerebral blood volume (CBV) measurements. Results In 49 of 52 patients, the AUC of the ICA was significantly larger than that of the sagittal sinus (p = 0.017). Measured after the first pass bolus, contrast enhancement remained 50% higher in the ICA just after the first pass bolus, and 30% higher 3 minutes later. CBV measurements were significantly lowered when the ICA was used without PVE correction. Conclusions Contradicting the assumptions underlying PVE correction, contrast in the ICA was significantly higher than in the sagittal sinus, even 3 minutes after the first pass of the contrast bolus. PVE correction might lead to overestimation of CBV if the CBV is calculated using the AUC of the time attenuation curves. PMID:24858308

  2. 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

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

    PubMed

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

    2014-10-01

    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

  4. 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

  5. Magnetic Resonance Imaging Quantification of Pulmonary Perfusion using Calibrated Arterial Spin Labeling

    PubMed Central

    Arai, Tatsuya J.; Prisk, G. Kim; Holverda, Sebastiaan; Sá, Rui Carlos; Theilmann, Rebecca J.; Henderson, A. Cortney; Cronin, Matthew V.; Buxton, Richard B.; Hopkins, Susan R.

    2011-01-01

    This demonstrates a MR imaging method to measure the spatial distribution of pulmonary blood flow in healthy subjects during normoxia (inspired O2, fraction (FIO2) = 0.21) hypoxia (FIO2 = 0.125), and hyperoxia (FIO2 = 1.00). In addition, the physiological responses of the subject are monitored in the MR scan environment. MR images were obtained on a 1.5 T GE MRI scanner during a breath hold from a sagittal slice in the right lung at functional residual capacity. An arterial spin labeling sequence (ASL-FAIRER) was used to measure the spatial distribution of pulmonary blood flow 1,2 and a multi-echo fast gradient echo (mGRE) sequence 3 was used to quantify the regional proton (i.e. H2O) density, allowing the quantification of density-normalized perfusion for each voxel (milliliters blood per minute per gram lung tissue). With a pneumatic switching valve and facemask equipped with a 2-way non-rebreathing valve, different oxygen concentrations were introduced to the subject in the MR scanner through the inspired gas tubing. A metabolic cart collected expiratory gas via expiratory tubing. Mixed expiratory O2 and CO2 concentrations, oxygen consumption, carbon dioxide production, respiratory exchange ratio, respiratory frequency and tidal volume were measured. Heart rate and oxygen saturation were monitored using pulse-oximetry. Data obtained from a normal subject showed that, as expected, heart rate was higher in hypoxia (60 bpm) than during normoxia (51) or hyperoxia (50) and the arterial oxygen saturation (SpO2) was reduced during hypoxia to 86%. Mean ventilation was 8.31 L/min BTPS during hypoxia, 7.04 L/min during normoxia, and 6.64 L/min during hyperoxia. Tidal volume was 0.76 L during hypoxia, 0.69 L during normoxia, and 0.67 L during hyperoxia. Representative quantified ASL data showed that the mean density normalized perfusion was 8.86 ml/min/g during hypoxia, 8.26 ml/min/g during normoxia and 8.46 ml/min/g during hyperoxia, respectively. In this subject, the

  6. 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.

  7. Bilateral antegrade perfusion of the superficial femoral artery to prevent limb ischaemia during combined use of Impella CP left ventricular assist device and extracorporeal life support.

    PubMed

    Kizner, Lukasz; Flottmann, Christian; Horstkotte, Dieter; Gummert, Jan

    2016-08-01

    The combined use of extracorporeal cardiac life support and the Impella left ventricular assist device is feasible in severe cardiogenic shock. Ischaemic complications due to the arterial cannulation may occur. The following cases show how the use of a perfusion adapter for bilateral antegrade leg perfusion prevents malperfusion of the lower extremities. PMID:27130716

  8. 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).

  9. [Cardiac SPECT/CT: correlation between atherosclerosis, significant coronary artery stenoses and myocardial perfusion parameters in patients with known coronary artery disease].

    PubMed

    Ubleis, C; Rist, C; Griesshammer, I; Becker, A; Becker, C; Hacker, M

    2010-04-01

    Invasive coronary angiography (ICA) and CT angiography (CTA) both enable significant coronary artery stenoses to be detected, but they are not suitable for assessing their hemodynamic relevance. This can be accomplished using myocardial perfusion scintigraphy (MPS) which, however, has limited specificity and spatial resolution. Regarding patients with known coronary artery disease (CAD) it is furthermore important to stratify patient's individual risk for severe cardiac events to guide therapy management.The results of our investigations in 158 patients with CAD indicate that global and regional calcium scores (CAC) do not correlate with the presence of myocardial perfusion defects and significant coronary artery stenoses, respectively. However, published literature has reported CAC as being an independent predictor of long-time survival.For clinical purposes it seems that non-invasive diagnostics with CTA, MPS and CAC screening can be useful even in patients with known CAD. CAC and global scar burden enable long-term risk-stratification, whereas fusion of CTA and MPS is useful to detect the culprit lesion of relevant perfusion defects and to select options for revascularization. PMID:20333503

  10. Assessment of single vessel coronary artery disease: results of exercise electrocardiography, thallium-201 myocardial perfusion imaging and radionuclide angiography

    SciTech Connect

    Port, S.C.; Oshima, M.; Ray, G.; McNamee, P.; Schmidt, D.H.

    1985-07-01

    The sensitivity of the commonly used stress tests for the diagnosis of coronary artery disease was analyzed in 46 patients with significant occlusion (greater than or equal to 70% luminal diameter obstruction) of only one major coronary artery and no prior myocardial infarction. In all patients, thallium-201 perfusion imaging (both planar and seven-pinhole tomographic) and 12 lead electrocardiography were performed during the same graded treadmill exercise test and radionuclide angiography was performed during upright bicycle exercise. Exercise rate-pressure (double) product was 22,307 +/- 6,750 on the treadmill compared with 22,995 +/- 5,622 on the bicycle (p = NS). Exercise electrocardiograms were unequivocally abnormal in 24 patients (52%). Qualitative planar thallium images were abnormal in 42 patients (91%). Quantitative analysis of the tomographic thallium images were abnormal in 41 patients (89%). An exercise ejection fraction of less than 0.56 or a new wall motion abnormality was seen in 30 patients (65%). Results were similar for the right (n = 11) and left anterior descending (n = 28) coronary arteries while all tests but the planar thallium imaging showed a lower sensitivity for isolated circumflex artery disease (n = 7). The specificity of the tests was 72, 83, 89 and 72% for electrocardiography, planar thallium imaging, tomographic thallium imaging and radionuclide angiography, respectively. The results suggest that exercise thallium-201 perfusion imaging is the most sensitive noninvasive stress test for the diagnosis of single vessel coronary artery disease.

  11. 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. PMID:22711674

  12. Myocardial perfusion imaging is an effective screening test for coronary artery disease in liver transplant candidates.

    PubMed

    Baker, Sally; Chambers, Charles; McQuillan, Patrick; Janicki, Piotr; Kadry, Zakiyah; Bowen, Daniel; Bezinover, Dmitri

    2015-04-01

    A reliable screening test for coronary artery disease (CAD) in liver transplant (LT) candidates with end-stage liver disease is essential because a high percentage of perioperative mortality and morbidity is CAD-related. In this study, the effectiveness of myocardial perfusion imaging (MPI) for identification of significant CAD in LT candidates was evaluated. Records of 244 patients meeting criteria for MPI were evaluated: 74 met inclusion criteria; 40 had a positive MPI and cardiology follow-up; 27 had a negative MPI and underwent LT; and seven had a negative MPI and then had coronary angiography or a significant cardiac event. A selective MPI interpretation strategy was established where MPI-positive patients were divided into high, intermediate, and low CAD risk groups. The overall incidence of CAD in this study population was 5.1% and our strategy resulted in PPV 20%, NPV 94%, sensitivity 80%, and specificity 50% for categorizing CAD risk. When applied only to the subset of patients categorized as high CAD risk, the strategy was more effective, with PPV 67%, NPV 97%, sensitivity 80%, and specificity 94%. We determined that renal dysfunction was an independent predictive factor for CAD (p < 0.0001, odds ratio = 8.1), and grades of coronary occlusion correlated significantly with chronic renal dysfunction (p = 0.0079). PMID:25604507

  13. Electrophysiological characterization of the cerebellum in the arterially perfused hindbrain and upper body of the rat.

    PubMed

    Cerminara, Nadia L; Rawson, John A; Apps, Richard

    2010-06-01

    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

  14. Design and validation of a system to simulate coronary flexure dynamics on arterial segments perfused ex vivo.

    PubMed

    VanEpps, J Scott; Londono, Ricardo; Nieponice, Alejandro; Vorp, David A

    2009-02-01

    Cyclic flexure of the coronary arteries can lead to spatially varying fluid and solid stress patterns. These patterns may explain the heterogenous distribution of atherosclerotic lesions. Here we describe the design and validation of an experimental system to simulate coronary-like flexure dynamics on intact arterial segments ex vivo. Our previously described ex vivo perfusion system was modified with a polymer flexure membrane controlled by a custom data acquisition/motion control system. The system was validated by perfusing arterial segments with pulsatile hemodynamics with or without cyclic flexure. Digital images were obtained to quantify dynamic vessel curvature and arc length. Tissue integrity was assessed by histology. The device generated physiologic curvatures (0-1.8 cm(-1)) at 1 Hz with a physiologic phase relationship with the pressure waveform. Additionally, the in vivo longitudinal extension ratio (40%) was maintained within 2.3% during the flexure cycle. Twelve hours of cyclic contact with the membrane did not compromise arterial segment integrity. This device provides a novel method to examine how the local biomechanical milieu could impact atherosclerotic lesion localization. PMID:18297319

  15. Significance of perfusion of the infarct related coronary artery for susceptibility to ventricular tachyarrhythmias in patients with previous myocardial infarction.

    PubMed Central

    Huikuri, H. V.; Koistinen, M. J.; Airaksinen, K. E.; Ikäheimo, M. J.

    1996-01-01

    OBJECTIVE--To study the significance of perfusion of the infarct related coronary artery for susceptibility to ventricular tachyarrhythmias in patients with a remote myocardial infarction. SETTING--Tertiary referral cardiac centre. METHODS--Angiographic filling of the infarct related artery was assessed in a consecutive series of 85 patients with different susceptibilities to ventricular tachyarrhythmias after previous (> 3 months) Q wave myocardial infarction: 30 patients had a history of cardiac arrest (n = 16) or sustained ventricular tachycardia (n = 14), and sustained ventricular tachyarrhythmia was inducible in these by programmed electrical stimulation (arrhythmia group); 47 patients had no clinical arrhythmic events and no inducible ventricular tachyarrhythmias during programmed ventricular stimulation (control group). Eight patients without a history of any arrhythmic events were inducible into ventricular tachycardia. RESULTS--The patients in the arrhythmia group were older (63 (SD 8) years) than the control patients (59 (6) years, P < 0.05), and had larger left ventricular volumes in cineangiography (P < 0.01), but ejection fraction, severity of left ventricular wall motion abnormalities, previous thrombolytic therapy, and time from previous infarction did not differ between the groups. Patients with susceptibility to ventricular tachyarrhythmias more often had a totally occluded infarct related artery on angiography (77%) than patients without arrhythmia susceptibility (21%) (P < 0.001), and complete collateral filling of the infarct artery in cases without complete anterograde filling was less common in the arrhythmia group than in the control group (P < 0.001). Patients without a history of malignant arrhythmia but with inducible ventricular tachyarrhythmia also had no or poor perfusion of the infarct artery more often than the patients without inducible arrhythmia (P < 0.001). Logistic multiple regression showed that no or poor anterograde or

  16. 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.

  17. New technique for showing the relation of tomographic myocardial perfusion images obtained with thallium-201 to the coronary arteries.

    PubMed Central

    Gibson, C J; Laird, E E; Williams, E D; Rajathurai, A; Mittra, B; Rankin, D

    1985-01-01

    A new technique has been developed for presenting myocardial tomograms that allows the observer to perceive the shape of the thallium-201 distribution directly. The surface of the myocardium was found by applying an interactive thresholding technique to a set of conventional transverse slices. Computer graphics techniques were used to display a shaded image of that surface on a television screen, showing the three dimensional shape of the myocardial surface from any chosen aspect. A set of normal preserved coronary arteries was digitised, and using scaling and transformation techniques these arteries were mapped on to the myocardial tomograms and a shaded surface image produced with superimposed coronary arteries. This provided a familiar anatomical framework for locating perfusion defects. Its value in identifying various diseased vessels was confirmed by a comparison of the tomographic findings with the angiographic findings in five individual cases. Images PMID:3876840

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

    PubMed

    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

    2013-06-01

    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. PMID:23457215

  19. Posterior Reversible Encephalopathy Syndrome Occurring After Uterine Artery Embolization for Uterine Myoma

    SciTech Connect

    Suzuki, Satoshi Tanigawa, Noboru; Kariya, Syuji; Komemushi, Atsushi; Kojima, Hiroyuki; Tokuda, Takanori; Kishimoto, Masanobu; Tomino, Atsutoshi; Fujioka, Masayuki; Kitazawa, Yasuhide; Sawada, Satoshi

    2011-02-15

    This case report describes posterior reversible encephalopathy syndrome (PRES) occurring after uterine artery embolization (UAE) for uterine myoma. This is the first report of PRES occurring after uterine vascular radiologic intervention. The mechanism by which UAE induced PRES is unclear.

  20. Quantifying fluctuations of resting state networks using arterial spin labeling perfusion MRI.

    PubMed

    Dai, Weiying; Varma, Gopal; Scheidegger, Rachel; Alsop, David C

    2016-03-01

    Blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) has been widely used to investigate spontaneous low-frequency signal fluctuations across brain resting state networks. However, BOLD only provides relative measures of signal fluctuations. Arterial Spin Labeling (ASL) MRI holds great potential for quantitative measurements of resting state network fluctuations. This study systematically quantified signal fluctuations of the large-scale resting state networks using ASL data from 20 healthy volunteers by separating them from global signal fluctuations and fluctuations caused by residual noise. Global ASL signal fluctuation was 7.59% ± 1.47% relative to the ASL baseline perfusion. Fluctuations of seven detected resting state networks vary from 2.96% ± 0.93% to 6.71% ± 2.35%. Fluctuations of networks and residual noise were 6.05% ± 1.18% and 6.78% ± 1.16% using 4-mm resolution ASL data applied with Gaussian smoothing kernel of 6mm. However, network fluctuations were reduced by 7.77% ± 1.56% while residual noise fluctuation was markedly reduced by 39.75% ± 2.90% when smoothing kernel of 12 mm was applied to the ASL data. Therefore, global and network fluctuations are the dominant structured noise sources in ASL data. Quantitative measurements of resting state networks may enable improved noise reduction and provide insights into the function of healthy and diseased brain. PMID:26661226

  1. Effects of arterial and venous volume infusion on coronary perfusion pressures during canine CPR.

    PubMed

    Gentile, N T; Martin, G B; Appleton, T J; Moeggenberg, J; Paradis, N A; Nowak, R M

    1991-08-01

    Intraarterial (IA) volume infusion has been reported to be more effective than intravenous (IV) infusion in treating cardiac arrest due to exsanguination. A rapid IA infusion was felt to raise intraaortic pressure and improve coronary perfusion pressure (CPP). The purpose of this study was to determine if IA or IV volume infusion could augment the effect of epinephrine on CPP during CPR in the canine model. Nineteen mongrel dogs with a mean weight of 26.3 +/- 4.2 kg were anesthetized and mechanically ventilated. Thoracic aortic (Ao), right atrial (RA) and pulmonary artery catheters were placed for hemodynamic monitoring. Additional Ao and central venous catheters were placed for volume infusion. Ventricular fibrillation was induced and Thumper CPR was begun after 5 min (t = 5). At t = 10, all dogs received 45 micrograms/kg IV epinephrine. Six animals received epinephrine alone (EPI). Five dogs received EPI plus a 500 cc bolus of normal saline over 3 min intravenously (EPI/IV). Another group (n = 8) received EPI plus the same fluid bolus through the aortic catheter (EPI/IA). Resuscitation was attempted at t = 18 using a standard protocol. There was a significant increase in CPP over baseline in all groups. The changes in CPP from baseline induced by EPI, EPI/IV and EPI/IA were 20.6 +/- 3.7, 22.8 +/- 4.2 and 22.2 +/- 2.4 mmHg, respectively. Volume loading did not augment the effect of therapeutic EPI dosing. By increasing both preload and afterload, volume administration may in fact be detrimental during CPR. PMID:1658894

  2. An Exploration of the Control of Micturition Using a Novel in Situ Arterially Perfused Rat Preparation

    PubMed Central

    Sadananda, Prajni; Drake, Marcus J.; Paton, Julian F. R.; Pickering, Anthony E.

    2011-01-01

    Our goal was to develop and refine a decerebrate arterially perfused rat (DAPR) preparation that allows the complete bladder filling and voiding cycle to be investigated without some of the restrictions inherent with in vivo experimentation [e.g., ease and speed of set up (30 min), control over the extracellular milieu and free of anesthetic agents]. Both spontaneous (naturalistic bladder filling from ureters) and evoked (in response to intravesical infusion) voids were routinely and reproducibly observed which had similar pressure characteristics. The DAPR allows the simultaneous measurement of bladder intra-luminal pressure, external urinary sphincter–electromyogram (EUS–EMG), pelvic afferent nerve activity, pudendal motor activity, and permits excellent visualization of the entire lower urinary tract, during typical rat filling and voiding responses. The voiding responses were modulated or eliminated by interventions at a number of levels including at the afferent terminal fields (intravesical capsaicin sensitization–desensitization), autonomic (ganglion blockade with hexamethonium), and somatic motor (vecuronium block of the EUS) outflow and required intact brainstem/hindbrain-spinal coordination (as demonstrated by sequential hindbrain transections). Both innocuous (e.g., perineal stimulation) and nociceptive (tail/paw pinch) somatic stimuli elicited an increase in EUS–EMG indicating intact sensory feedback loops. Spontaneous non-micturition contractions were observed between fluid infusions at a frequency and amplitude of 1.4 ± 0.9 per minute and 1.4 ± 0.3 mmHg, respectively and their amplitude increased when autonomic control was compromised. In conclusion, the DAPR is a tractable and useful model for the study of neural bladder control showing intact afferent signaling, spinal and hindbrain co-ordination and efferent control over the lower urinary tract end organs and can be extended to study bladder pathologies and trial novel

  3. 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

  4. 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.

  5. 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).

  6. 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. PMID:25016023

  7. Hepatic perfusion index in evaluating treatment effect of transcatheter hepatic artery embolization in patients with hepatocellular carcinoma.

    PubMed

    Lin, W Y; Wang, S J; Yeh, S H

    1995-01-01

    We assumed the hepatic perfusion index (HPI) in patients with hepatocellular carcinoma (HCC) treated by transcatheter arterial embolization (TAE) and compared the results with the following CT findings. From September 1993 to February 1994, 15 patients with newly diagnosed HCC, proven by biopsy, were studied. Hepatic perfusion index (HPI) studies were performed before-TAE as well as on the 1st day and 7th day post-TAE, and CT scans were performed before and one month after the TAE. HPI at 1st-day post-TAE (HPI1) over HPI pre-TAE (HPIp) and HPI at 7th-day post-TAE (HPI7) over HPIp were calculated. The HPI7/HPIps were chosen to evaluate the efficacy of TAE because they had better correlation with the CT findings than HPI1/HPIps. CT scans performed one month after the TAE showed obvious reduction of tumor size in all 7 patients with a HPI7/HPI p < 0.85 but in only 2 of the 7 patients with a HPI7/HPI p > or = 0.85. The difference was significant, with a p-value of 0.01 by Fisher's exact test. We consider that the HPI with its characteristics of relative safety, convenience, low radiation exposure, and inexpense, may provide an useful modality for early prediction of the efficacy of hepatic artery embolization in the treatment of HCC. PMID:7617083

  8. Voxel-level comparison of arterial spin-labeled perfusion magnetic resonance imaging in adolescents with internet gaming addiction

    PubMed Central

    2013-01-01

    Background Although recent studies have clearly demonstrated functional and structural abnormalities in adolescents with internet gaming addiction (IGA), less is known about how IGA affects perfusion in the human brain. We used pseudocontinuous arterial spin-labeling (ASL) perfusion functional magnetic resonance imaging (fMRI) to measure the effects of IGA on resting brain functions by comparing resting cerebral blood flow in adolescents with IGA and normal subjects. Methods Fifteen adolescents with IGA and 18 matched normal adolescents underwent structural and perfusion fMRI in the resting state. Direct subtraction, voxel-wise general linear modeling was performed to compare resting cerebral blood flow (CBF) between the 2 groups. Correlations were calculated between the mean CBF value in all clusters that survived AlphaSim correction and the Chen Internet Addiction Scale (CIAS) scores, Barratt Impulsiveness Scale-11 (BIS-11) scores, or hours of Internet use per week (hours) in the 15 subjects with IGA. Results Compared with control subjects, adolescents with IGA showed significantly higher global CBF in the left inferior temporal lobe/fusiform gyrus, left parahippocampal gyrus/amygdala, right medial frontal lobe/anterior cingulate cortex, left insula, right insula, right middle temporal gyrus, right precentral gyrus, left supplementary motor area, left cingulate gyrus, and right inferior parietal lobe. Lower CBF was found in the left middle temporal gyrus, left middle occipital gyrus, and right cingulate gyrus. There were no significant correlations between mean CBF values in all clusters that survived AlphaSim correction and CIAS or BIS-11 scores or hours of Internet use per week. Conclusions In this study, we used ASL perfusion fMRI and noninvasively quantified resting CBF to demonstrate that IGA alters the CBF distribution in the adolescent brain. The results support the hypothesis that IGA is a behavioral addiction that may share similar neurobiological

  9. 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.

  10. Quantitative cerebral perfusion assessment using microscope-integrated analysis of intraoperative indocyanine green fluorescence angiography versus positron emission tomography in superficial temporal artery to middle cerebral artery anastomosis

    PubMed Central

    Kobayashi, Shinya; Ishikawa, Tatsuya; Tanabe, Jun; Moroi, Junta; Suzuki, Akifumi

    2014-01-01

    Background: Intraoperative qualitative indocyanine green (ICG) angiography has been used in cerebrovascular surgery. Hyperperfusion may lead to neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. The purpose of this study is to quantitatively evaluate intraoperative cerebral perfusion using microscope-integrated dynamic ICG fluorescence analysis, and to assess whether this value predicts hyperperfusion syndrome (HPS) after STA-MCA anastomosis. Methods: Ten patients undergoing STA-MCA anastomosis due to unilateral major cerebral artery occlusive disease were included. Ten patients with normal cerebral perfusion served as controls. The ICG transit curve from six regions of interest (ROIs) on the cortex, corresponding to ROIs on positron emission tomography (PET) study, was recorded. Maximum intensity (IMAX), cerebral blood flow index (CBFi), rise time (RT), and time to peak (TTP) were evaluated. Results: RT/TTP, but not IMAX or CBFi, could differentiate between control and study subjects. RT/TTP correlated (|r| = 0.534-0.807; P < 0.01) with mean transit time (MTT)/MTT ratio in the ipsilateral to contralateral hemisphere by PET study. Bland–Altman analysis showed a wide limit of agreement between RT and MTT and between TTP and MTT. The ratio of RT before and after bypass procedures was significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.60 ± 0.032 and 0.80 ± 0.056, respectively; P = 0.017). The ratio of TTP was also significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.64 ± 0.081 and 0.85 ± 0.095, respectively; P = 0.017). Conclusions: Time-dependent intraoperative parameters from the ICG transit curve provide quantitative information regarding cerebral circulation time with quality and utility comparable to information obtained by PET. These parameters may help predict the occurrence of postoperative HPS. PMID

  11. 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.

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

    SciTech Connect

    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.

  13. Reliability of contrast-enhanced ultrasound for the assessment of muscle perfusion in health and peripheral arterial disease.

    PubMed

    Thomas, Kate N; Cotter, James D; Lucas, Samuel J E; Hill, Brigid G; van Rij, André M

    2015-01-01

    We investigated the reliability of contrast-enhanced ultrasound (CEUS) in assessing calf muscle microvascular perfusion in health and disease. Response to a post-occlusive reactive hyperaemia test was repeated on two occasions >48 h apart in healthy young (28 ± 7 y) and elderly controls (70 ± 5 y), and in peripheral arterial disease patients (PAD, 69 ± 7 y; n = 10, 9 and 8 respectively). Overall, within-individual reliability was poor (coefficient of variation [CV] range: 15-87%); the most reliable parameter was time to peak (TTP, 15-48% CV). Nevertheless, TTP was twice as long in elderly controls and PAD compared to young (19.3 ± 10.4 and 22.0 ± 8.6 vs. 8.9 ± 6.2 s respectively; p < 0.01), and area under the curve for contrast intensity post-occlusion (a reflection of blood volume) was ∼50% lower in elderly controls (p < 0.01 versus PAD and young). Thus, CEUS assessment of muscle perfusion during reactive hyperaemia demonstrated poor reliability, yet still distinguished differences between PAD patients, elderly and young controls. PMID:25308937

  14. Anomalous origin of the left coronary artery from the pulmonary artery in an adult: tubular reconstruction of the left main coronary artery under coronary perfusion.

    PubMed

    Murashita, T; Kubota, T; Kanaoka, T; Zakaria, M; Yasuda, K

    1997-01-01

    A 38-year-old female with anomalous origin of the left coronary artery (LCA) from pulmonary artery was surgically corrected by tubular reconstruction of the left main coronary artery (LMCA) using the pulmonary artery wall, and this repair was performed under beating heart. Thus, the pulmonary artery was divided above the orifice level and just above the pulmonary valve, and the commissure between nonfacing and left side sinuses was dissected away from the pulmonary artery wall to obtain lateral flaps. The pulmonary artery defect was reconstructed with a roll using an autologous pericardial patch, while the detached commissure was suspended on the pericardial patch. The long tube constructed using pulmonary artery tissue was anastomosed to the anterior aspect of the ascending aorta. These procedures were performed under beating heart simply by clamping the LMCA, since the preoperative myocardial contrast echocardiography confirmed the adequate coronary collateral flow from the right circulation. The postoperative course was uneventful, and a coronary artery angiogram demonstrated a widely patent LMCA. Our experience suggests that, in adult cases, this procedure could be performed without myocardial ischemia simply by clamping the LMCA because of well-developed coronary collateral arteries. The safety of this technique could be confirmed by myocardial contrast echocardiography. PMID:9591183

  15. Improved myocardial perfusion after transmyocardial laser revascularization in a patient with microvascular coronary artery disease

    PubMed Central

    Mayeda, Guy S; Burstein, Steven; Gheissari, Ali; French, William J; Thomas, Joseph; Kloner, Robert A

    2014-01-01

    We report the case of a 59-year-old woman who presented with symptoms of angina that was refractory to medical management. Although her cardiac catheterization revealed microvascular coronary artery disease, her symptoms were refractory to optimal medical management that included ranolazine. After undergoing transmyocardial revascularization, her myocardial ischemia completely resolved and her symptoms dramatically improved. This case suggests that combination of ranolazine and transmyocardial revascularization can be applied to patients with microvascular coronary artery disease. PMID:27489642

  16. Feasibility of Using Pseudo-Continuous Arterial Spin Labeling Perfusion in a Geriatric Population at 1.5 Tesla

    PubMed Central

    Sigurdsson, Sigurdur; Forsberg, Lars; Aspelund, Thor; van der Geest, Rob J.; van Buchem, Mark A.; Launer, Lenore J.; Gudnason, Vilmundur; van Osch, Matthias J.

    2015-01-01

    Objectives To evaluate the feasibility of using pseudo-continuous arterial spin labeling (pCASL) perfusion in a geriatric population at 1.5-Tesla. Materials and Methods In 17 participants (mean age 78.8±1.63 years) we assessed; 1) inter-session repeatability and reliability of resting state perfusion in 27 brain regions; 2) brain activation using finger-tapping as a means to evaluate the ability to detect flow differences; 3) reliability by comparing cerebral blood flow (CBF) with pCASL to CBF with phase contrast (PC-MR). Results The CBF (mean±standard deviation (SD)) for the whole brain grey matter (GM) was 40.6±8.4 and 41.4±8.7 ml/100g/min for the first and second scan respectively. The within-subject standard deviation (SDw), the repeatability index (RI) and intra-class correlation coefficient (ICC) across the 27 regions ranged from 1.1 to 7.9, 2.2 to 15.5 and 0.35 to 0.98 respectively. For whole brain GM the SDw, RI and ICC were 1.6, 3.2 and 0.96 respectively. The between-subject standard deviation (SDB) was larger than the SDw for all regions. Comparison of CBF at rest and activation on a voxel level showed significantly higher perfusion during finger tapping in the motor- and somatosensory regions. The mean CBF for whole brain GM was 40.6±8.4 ml/100g/min at rest and 42.6±8.6 ml/100g/min during activation. Finally the reliability of pCASL against the reference standard of PC-MR was high (ICC = 0.80). The mean CBF for whole brain measured with PC-MRI was 54.3±10.1 ml/100g/min and 38.3±7.8 ml/100g/min with pCASL. Conclusions The results demonstrate moderate to high levels of repeatability and reliability for most brain regions, comparable to what has been reported for younger populations. The performance of pCASL at 1.5-Tesla shows that region-specific perfusion measurements with this technique are feasible in studies of a geriatric population. PMID:26659363

  17. 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

  18. [Abnormal cerebral blood flow distributions during the post-ictal phase of febrile status epilepticus in three pediatric patients measured by arterial spin labeling perfusion MRI].

    PubMed

    Hirano, Keiko; Fukuda, Tokiko

    2016-05-01

    The ability to visualize brain perfusion is important for identifying epileptic foci. We present three pediatric cases showing asymmetrical cerebral blood flow (CBF) distributions during the post-ictal phase of febrile status epilepticus measured by arterial spin labeling (ASL) perfusion MRI. During the acute phase, regional CBF measurements in the areas considered including epileptic foci were higher than in the corresponding area of the contralateral hemisphere, though the exact quantitative value varied between cases. We could not identify the correct epileptogenic foci, because those ASL images were taken after the prolonged and extraordinary activation of neurons in the affected area. During the recovery phase, the differences reduced and the average regional CBF measurement was 54.6 ± 6.1 ml/100 g per minute, which was a little less than the number of previous ASL studies. ASL perfusion MRI imaging provides a method for evaluating regional CBF by using magnetically labeled arterial blood water as an endogenous tracer. With this technique, we can repeatedly evaluate both the brain structure and the level of perfusion at the same time. ASL is noninvasive and easily accessible, and therefore it could become a routine tool for assessment of perfusion in daily practice of pediatric neurology. PMID:27349086

  19. 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. PMID:24103665

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

    PubMed Central

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

    2015-01-01

    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. PMID:26365751

  1. Myocardial perfusion and coronary flow reserve in mammary artery and saphenous vein by-pass grafts with maximal dipyridamole vasodilation

    SciTech Connect

    Lassar, T.; Hendrix, L.; Port, S.; Ray, G.; Kamath, M.L.; Schmidt, D.H.

    1985-05-01

    This study was done to assess the functional adequacy of regional myocardial perfusion in angiographically patent internal mammary artery (IMAG) and saphenous vein (SVG) bypass grafts under conditions of maximal vasodilation. Utilizing the xenon-133 washout technique, quantitative RMP in ml/100g/min was measured at rest (R RMP), and after 0.6mg/kg of intravenous dipyridamole (DP RMP) via selective injection into coronary arteries with >75% diameter stenosis (SCA), angiographically normal vessels (NLCA), and two weeks postoperatively after IMAG or SVG. RMP and coronary flow reserve (CFR=DP RMP / R RMP) were compared between groups selected for study and the results are presented. The authors discuss that compared to SCA, there is a trend towards improved RMP under conditions of maximal vasodilatory demand in both IMAG and SVG. In part because of elevated R RMP, the CFR ratio may not always reflect this improvement, and finally, the trend towards higher DP RMP in SVG suggest that they may supply more adequate nutrient flow than IMAG during situations of peak demand.

  2. Functional Relevance of Coronary Artery Disease by Cardiac Magnetic Resonance and Cardiac Computed Tomography: Myocardial Perfusion and Fractional Flow Reserve

    PubMed Central

    Andreini, Daniele; Bertella, Erika; Mushtaq, Saima; Guaricci, Andrea Igoren; Pepi, Mauro

    2015-01-01

    Coronary artery disease (CAD) is one of the leading causes of morbidity and mortality and it is responsible for an increasing resource burden. The identification of patients at high risk for adverse events is crucial to select those who will receive the greatest benefit from revascularization. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography, but the diagnostic yield of elective invasive coronary angiography remains unfortunately low. Stress myocardial perfusion imaging by cardiac magnetic resonance (stress-CMR) has emerged as an accurate technique for diagnosis and prognostic stratification of the patients with known or suspected CAD thanks to high spatial and temporal resolution, absence of ionizing radiation, and the multiparametric value including the assessment of cardiac anatomy, function, and viability. On the other side, cardiac computed tomography (CCT) has emerged as unique technique providing coronary arteries anatomy and more recently, due to the introduction of stress-CCT and noninvasive fractional flow reserve (FFR-CT), functional relevance of CAD in a single shot scan. The current review evaluates the technical aspects and clinical experience of stress-CMR and CCT in the evaluation of functional relevance of CAD discussing the strength and weakness of each approach. PMID:25692133

  3. Evaluation of changes in the parameters of brain tissue perfusion in multi-slice computed tomography in patients after carotid artery stenting

    PubMed Central

    Szarmach, Arkadiusz; Halena, Grzegorz; Buczny, Jacek; Studniarek, Michał; Markiet, Karolina; Szurowska, Edyta; Retkowski, Mariusz; Piskunowicz, Maciej

    2011-01-01

    Summary Background: CT perfusion of the brain allows functional evaluation of cerebral blood flow. Patients with chronic internal carotid artery (ICA) stenosis may suffer from malperfusion. Improvement of cerebral blood flow and remission of neurological symptoms indicate the effectiveness of treatment of internal carotid artery stenosis. Material/Methods: The aim of the study was to analyze alterations within cerebral perfusion parameters in CT brain perfusion examination in patients who were scheduled for endovascular therapy due to ICA stenosis. Forty patients with ICA stenosis of over 79% who were included in this prospective study underwent perfusion CT examination twice – 24 hours prior to stenting and after 6–8 weeks following the procedure. CBF, CBV, MTT and TTP were evaluated. Results: Prior to endovascular therapy, an increase in MTT and TTP, and a decrease in CBV and CBF were observed within arterial supply of the hemisphere ipsilateral to stenosis. After the procedure, a decrease in MTT and TTP was seen in all cases, while no statistically significant changes of CBF or CBV were observed. MTT proved to be the most sensitive indicator of ICA stenosis, as its values allowed differentiation between critical and non-critical stenosis. No correlation between the degree of ICA stenosis and TTP values was found. Mild cerebral hyperperfusion syndrome (CHS) was observed in only one patient and the difference between pre-treatment MTT values calculated for both hemispheres was shown to be a prognostic factor for CHS incidence. Conclusions: Endovascular stent placing in patients with hemodynamically significant internal carotid artery stenosis results in alteration of perfusion parameters, especially concerning TTP and MTT. PMID:22802836

  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. Anger camera imaging of perfused and nonperfused brain tissue with intra-arterial 133Xenon technique.

    PubMed

    Guldberg, C; Karle, A; Jørgensen, P B

    1977-12-30

    The regional cerebral blood flow, the regional blood flow distribution, and the regional distribution of perfused (= vital) brain tissue been imaged with a digitalized conventional Anger camer. An analog scaler was placed behind the PM-tubes to reduce dead-time loss. The input pulse rate was doubled to counteract the effect of scaling on counting statistics, and the gamma emission was filtered through 1 mm of brass to increase the fraction of the integral count rate within the 40% window. In this way the 31 keV peak disappears, and Compton scatter and disturbing coincidences are markedly reduced. This improves spatial resolution. The flow parameters are imaged regionally in 3 X 3 mm2 matrix elements after flat field correction and smoothing. The matrix is 64 X 64 interpolated to 128 X 128. Patient studies emphasized the importance of imaging the distribution of perfused and nonperfused tissue in cases of infarctions, dilacerations, etc., where angiography and conventional brain scanning may often be negative. PMID:415863

  6. Real-time Assessment of Flow Reversal in an Eccentric Arterial Stenotic Model

    PubMed Central

    Ai, Lisong; Zhang, Lequan; Dai, Wangde; Hu, Changhong; Shung, K. Kirk; Hsiai, Tzung K.

    2010-01-01

    Plaque rupture is the leading cause of acute coronary syndromes and stroke. Plaque formation, or otherwise known as stenosis, preferentially occurs in the regions of arterial bifurcation or curvatures. To date, real-time assessment of stenosis-induced flow reversal remains a clinical challenge. By interfacing Micro-electro-mechanical Systems (MEMS) thermal sensors with the high frequency Pulsed Wave (PW) Doppler ultrasound, we proposed to assess flow reversal in the presence of an eccentric stenosis. We developed a 3-D stenotic model (inner diameter of 6 mm, an eccentric stenosis with a height of 2.75mm and width of 21 mm) simulating a superficial arterial vessel. We demonstrated that heat transfer from the sensing element (2 × 80 μm) to the flow field peaked as a function of flow rates at the throat of the stenosis alone the center/midline of arterial model, and dropped downstream from the stenosis where flow reversal was detected by the high frequency ultrasound device at 45 MHz. Computational fluid dynamics (CFD) codes were in agreement with the ultrasound-acquired flow profiles upstream, downstream, and at the throat of the stenosis. Hence, we characterized regions of eccentric stenosis in terms of changes in heat transfer alone the midline of vessel and identified points of flow reversal with high spatial and temporal resolution. PMID:20655537

  7. 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

  8. Incremental Diagnostic Performance of Combined Parameters in the Detection of Severe Coronary Artery Disease Using Exercise Gated Myocardial Perfusion Imaging

    PubMed Central

    Liu, Chia-Ju; Wu, Yen-Wen; Ko, Kuan-Yin; Chen, Yi-Chieh; Cheng, Mei-Fang; Yen, Ruoh-Fang; Tzen, Kai-Yuan

    2015-01-01

    Purpose Myocardial perfusion imaging (MPI) using gated single-photon emission tomography (gSPECT) may underestimate the severity of coronary artery disease (CAD). This study aimed to evaluate the significance of combined parameters derived from gSPECT, as well as treadmill stress test parameters, in the detection of severe CAD. Methods A total of 211 consecutive patients referred for exercise MPI between June 2011 and June 2013 (who received invasive coronary angiography within six months after MPI) were retrospectively reviewed. Exercise MPI was performed with Bruce protocol and 201Tl injected at peak exercise. Gated SPECT was performed using a cadmium-zinc-telluride camera and processed by QPS/QGS software. Perfusion defect abnormalities such as sum stress score (SSS); sum difference score, algorithm-derived total perfusion deficits, transient ischemic dilatation ratios of end-diastolic volumes and end-systolic volumes, post-stress changes in ejection fraction, and lung/heart ratio (LHR) were calculated. Treadmill parameters, including ST depression (STD) at the 1st and 3rd minutes of recovery stage (1’STD and 3’STD), maximal STD corrected by heart rate increment (ST/HR), heart rate decline in 1st and 3rd minutes of recovery stage, recovery heart rate ratio (HR ratio), systolic and mean blood pressure ratios (SBP ratio and MAP ratio) during recovery phase were recorded. Diagnostic performances of these parameters were analyzed with receiver operating characteristic (ROC) analysis and logistic regression for detection of left main (≥ 50%) or 3-vessel disease (all ≥ 70% luminal stenosis) on invasive angiography. Results Among various MPI and treadmill parameters used for detection of severe CAD, SSS and ST/HR had the highest AUC (0.78, 0.73, p = NS) and best cut-off values (SSS > 6, ST/HR > 17.39 10-2mV/bpm), respectively. By univariate logistic regression, all parameters except 1’HRR, 3’HRR, SBP and MAP ratios increased the odds ratio of severe CAD

  9. Mismatch of Low Perfusion and High Permeability Predicts Hemorrhagic Transformation Region in Acute Ischemic Stroke Patients Treated with Intra-arterial Thrombolysis

    PubMed Central

    Chen, Hui; Liu, Nan; Li, Ying; Wintermark, Max; Jackson, Alan; Wu, Bing; Su, Zihua; Chen, Fei; Hu, Jun; Zhang, Yongwei; Zhu, Guangming

    2016-01-01

    This study sought to determine whether the permeability related parameter Ktrans, derived from computed tomography perfusion (CTP) imaging, can predict hemorrhagic transformation (HT) in patients with acute ischemic stroke who receive intra-arterial thrombolysis. Data from patients meeting the criterion were examined. CTP was performed and Ktrans maps were used to assess the permeability values in HT and non-HT regions. A receiver operating characteristic (ROC) curve was calculated, showing the sensitivity and specificity of Ktrans for predicting HT risk. Composite images were produced to illustrate the spatial correlations among perfusion, permeability changes and HT. This study examined 41 patients. Twenty-six patients had hemorrhagic infarction and 15 had parenchymal hemorrhage. The mean Ktrans value in HT regions was significantly lower than that in the non-HT regions (0.26 ± 0.21/min vs. 0.78 ± 0.64/min; P < 0.001). The ROC curve analysis identified an optimal cutoff value of 0.334/min for Ktrans to predict HT risk. Composite images suggested ischemic regions with low permeability, or the mismatch area of low perfusion and high permeability, more likely have HT. HT regions after intra-arterial thrombolysis had lower permeability values on Ktrans maps. The mismatch area of lower perfusion and higher permeability are more likely to develop HT. PMID:27302077

  10. Mismatch of Low Perfusion and High Permeability Predicts Hemorrhagic Transformation Region in Acute Ischemic Stroke Patients Treated with Intra-arterial Thrombolysis.

    PubMed

    Chen, Hui; Liu, Nan; Li, Ying; Wintermark, Max; Jackson, Alan; Wu, Bing; Su, Zihua; Chen, Fei; Hu, Jun; Zhang, Yongwei; Zhu, Guangming

    2016-01-01

    This study sought to determine whether the permeability related parameter K(trans), derived from computed tomography perfusion (CTP) imaging, can predict hemorrhagic transformation (HT) in patients with acute ischemic stroke who receive intra-arterial thrombolysis. Data from patients meeting the criterion were examined. CTP was performed and K(trans) maps were used to assess the permeability values in HT and non-HT regions. A receiver operating characteristic (ROC) curve was calculated, showing the sensitivity and specificity of K(trans) for predicting HT risk. Composite images were produced to illustrate the spatial correlations among perfusion, permeability changes and HT. This study examined 41 patients. Twenty-six patients had hemorrhagic infarction and 15 had parenchymal hemorrhage. The mean K(trans) value in HT regions was significantly lower than that in the non-HT regions (0.26 ± 0.21/min vs. 0.78 ± 0.64/min; P < 0.001). The ROC curve analysis identified an optimal cutoff value of 0.334/min for K(trans) to predict HT risk. Composite images suggested ischemic regions with low permeability, or the mismatch area of low perfusion and high permeability, more likely have HT. HT regions after intra-arterial thrombolysis had lower permeability values on K(trans) maps. The mismatch area of lower perfusion and higher permeability are more likely to develop HT. PMID:27302077

  11. Medullary hemangioblastoma in a child with von Hippel-Lindau disease: vascular tumor perfusion depicted by arterial spin labeling and dynamic contrast-enhanced imaging.

    PubMed

    Goo, Hyun Woo; Ra, Young-Shin

    2015-07-01

    Medullary hemangioblastoma is very rare in children. Based on small nodular enhancement with peritumoral edema and without dilated feeding arteries on conventional MRI, hemangioblastoma, pilocytic astrocytoma, oligodendroglioma, and ganglioglioma were included in the differential diagnosis of the medullary tumor. In this case report, the authors emphasize the diagnostic value of arterial spin labeling and dynamic contrast-enhanced MRI in demonstrating vascular tumor perfusion of hemangioblastoma in a 12-year-old boy who was later found to have von Hippel-Lindau disease. PMID:25885801

  12. Prediction of Flow-Limiting Fractional Flow Reserve in Patients With Stable Coronary Artery Disease Based on Quantitative Myocardial Perfusion Imaging.

    PubMed

    Tanaka, Haruki; Takahashi, Teruyuki; Kozono, Nami; Tanakamaru, Yoshiki; Ohashi, Norihiko; Yasunobu, Yuji; Tanaka, Koichi; Okada, Takenori; Kaseda, Shunichi; Nakanishi, Toshio; Kihara, Yasuki

    2016-05-01

    Although fractional flow reserve (FFR) and myocardial perfusion imaging (MPI) findings fundamentally differ, several cohort studies have revealed that these findings correlate. Here, we investigated whether flow-limiting FFR could be predicted from adenosine stress thallium-201 MPI with single-photon emission computed tomography (SPECT) findings derived from 84 consecutive, prospectively identified patients with stable coronary artery disease and 212 diseased vessels. Among them, FFR was measured in 136 diseased vessels (64%). The findings were compared with regional perfusion abnormalities including stress total perfusion defect (TPD) - rest TPD determined using quantitative perfusion single-photon emission computed tomography software. The FFR inversely correlated the most accurately with stress TPD - rest TPD (r = -0.552, p <0.001). Predictors of major vessels of interest comprising FFR <0.80, included stress TPD - rest TPD, the transient ischemic dilation ratio, left ventricular ejection fraction at rest and beta blockers for left anterior descending artery (LAD) regions, and stress TPD - rest TPD, left ventricular mass, left ventricular ejection fraction at rest, right coronary artery lesions, the transient ischemic dilation ratio, and age for non-LAD regions. The diagnostic accuracy of formulas to predict major vessels of interest with FFR <0.80 was high (sensitivity, specificity and accuracy for LAD and non-LAD: 84%, 87% and 86%, and 75%, 93% and 87%, respectively). In conclusion, although somewhat limited by a sample size and a single-center design, flow-limiting FFR could be predicted from MPI findings with a defined probability. A cohort study might validate our results and provide a novel adjunctive tool with which to diagnose functionally significant coronary artery disease from MPI findings. PMID:26970815

  13. Target hepatic artery regional chemotherapy and bevacizumab perfusion in liver metastatic colorectal cancer after failure of first-line or second-line systemic chemotherapy.

    PubMed

    Chen, Hui; Zhang, Ji; Cao, Guang; Liu, Peng; Xu, Haifeng; Wang, Xiaodong; Zhu, Xu; Gao, Song; Guo, Jianhai; Zhu, Linzhong; Zhang, Pengjun

    2016-02-01

    Colorectal cancer liver metastasis (CRLM) is a refractory disease after failure of first-line or second-line chemotherapy. Bevacizumab is recommended as first-line therapy for advanced colorectal cancer, but is unproven in CRLM through the hepatic artery. We report favorable outcomes with targeted vessel regional chemotherapy (TVRC) for liver metastatic gastric cancer. TVRC with FOLFOX and bevacizumab perfusion through the hepatic artery was attempted for CRLM for efficacy and safety evaluation. In a single-institution retrospective observational study, 246 patients with CRLM after at least first-line or second-line failure of systemic chemotherapy received TVRC with FOLFOX (i.e. oxaliplatin, leucovorin, and 5-fluorouracil). Of 246 patients, 63 were enrolled into two groups: group 1 (n=30) received bevacizumab and TVRC following tumor progression during previous TVRC treatments; group 2 (n=33) received TVRC plus bevacizumab for CRLM on initiating TVRC. There were no significant differences in the median survival time (14.7 vs. 13.2 months, P=0.367), although the median time to progression was significant (3.3 vs. 5.5 months, P=0.026) between groups. No severe adverse events related to TVRC plus bevacizumab perfusion occurred. Target vessel regional chemotherapy with FOLFOX plus bevacizumab perfusion through the hepatic artery was effective and safe in CRLM. The optimal combination of TVRC and bevacizumab needs further confirmation in future phase II-III clinical trials. PMID:26566233

  14. 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.

  15. 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)

  16. 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. PMID:27328380

  17. The effect of CO sub 2 on pulmonary artery pressure (P sub pa ) over time in the isolated perfused rabbit lung

    SciTech Connect

    Reynolds, P.; Shayevitz, J. )

    1991-03-11

    The isolated perfused rabbit lung model is used in studies of pulmonary hemodynamics, structure, and function under conditions closely resembling those which occur in living animals. The purpose of this study is to observe changes in P{sub pa} in response to differing concentrations of CO{sub 2} over time. After rapid exsanguination a tracheostomy was performed. Cannulas were secured in the main pulmonary artery and the left atrium. The lungs were perfused with Krebs-Henseleit buffer mixed with blood at a rate of 120 ml/min with recirculation. The temperature of the perfusate was maintained between 35 and 38C. The lungs were then ventilated with 5% CO{sub 2} in air with a tidal volume of 10 ml/kg at 20 breaths/min. CO{sub 2} was altered randomly by ventilating the lungs 2, 5 or 10% CO{sub 2} in air. Metabolic acidosis was corrected with NaHCO{sub 3}. In the first two hour period after lung perfusion was begun, the model was allowed to stabilize at each CO{sub 2} concentration, and pH, pCO{sub 2}, pO{sub 2}, and base excess were determined at each P{sub pa}. All measurements were repeated in the second period beginning two hours after lung perfusion was started. P{sub pa} was plotted against pH for each animal in both early and late phases, and simple regression analysis was performed. The slopes and the y intercepts for the data sets in both groups were compared using one factor ANOVA, and were found to be significantly different, implying a statistical difference between regression lines. In the early phase this model behaves like the in vivo lung, i.e. hypercarbia appears to increase, while hypocarbia decreases, P{sub pa}. During the late phase of lung perfusion the opposite occurs.

  18. Role of exercise thallium-201 myocardial perfusion scintigraphy in predicting prognosis in suspected coronary artery disease

    SciTech Connect

    Koss, J.H.; Kobren, S.M.; Grunwald, A.M.; Bodenheimer, M.M.

    1987-03-01

    While exercise thallium imaging has improved sensitivity and specificity for detection of coronary artery disease (CAD), its predictive value for morbid cardiac events is unclear. Of 532 consecutive patients who underwent exercise thallium imaging, follow-up was complete in 515 (97%) after an average of 36 months (range 31 to 48). Two hundred six patients had an abnormal exercise thallium response and 309 had a normal response. Twenty morbid cardiac events occurred (13 deaths and 7 acute myocardial infarctions (AMI)). Of the 13 patients who died, 12 had abnormal thallium results. Overall, 5.8% of the patients with abnormal thallium results died, in contrast to 0.3% of patients with normal results. Of the 7 patients who had a nonfatal AMI, 3 had abnormal exercise thallium results. Moreover, similar proportions of patients (1.4% and 1.3%) with normal and abnormal exercise thallium results had nonfatal AMI. Presence or absence of pathologic Q waves and inclusion of exercise electrocardiographic results did not significantly alter the results. Thus, although a normal exercise thallium response significantly reduces the likelihood of cardiovascular death, its predictive value for nonfatal AMI is limited. Moreover, the relatively low event rate for patients with a positive exercise thallium response further limits its prognostic value.

  19. 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. PMID:26502309

  20. 3-Fluoro-Deoxyglucose for the assessment of cerebral perfusion and glucose transport - Indications for extracranial-intracranial arterial bypass and followup studies

    SciTech Connect

    Mehdorn, H.M.; Vyska, K.; Machulla, H.J.; Knust, E.J.

    1985-05-01

    3-Fluor-Deoxyglucose (3FDG) is a glucose-analogue which is transported across the blood-brain-barrier by the same carrier as glucose but is only phoshorylated to a minor part. By a newly developed model, it became possible to estimate both cerebral perfusion and glucose transport in a single examination, determining the Michaelis-Menten-constant K/sub M/ and the maximal velocity v/sub m/. Normal values were determined as follows: gray matter perfusion 88+-8 ml/ 100g min; v/sub m/ was 2.46 ..mu..mol/g min; K/sub M/ was 6.42 ..mu..mol/g. This method was applied successfully in a series of 15 patients with cerebral ischemia to select suitable candidates for extacranial-intracranial (EC-IC) arterial bypass surgery and to follow them up to 15 months postop. In patients with minor strokes and transient ischemic attacks (TIA), areas which appeared normal in conventional CT presented with reduced perfusion values (down to 67 ml/ 100 g min) and either normal or reduced v/sub m/ (down to 0.8 ..mu..mol/g min). These patients were thought optimal candidates for EC-IC bypass in order to improve the misery perfusion rate.

  1. 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

  2. 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

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

    2016-03-01

    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; R = 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; R = 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

  3. Case Report: Apixaban-Associated Gluteal Artery Extravasation Reversed With PCC3 Without FFP.

    PubMed

    Denetclaw, Tina Harrach; Tam, Jacqueline; Arias, Victor; Kim, Rachel; Martin, Christopher

    2016-08-01

    Apixaban, an oral factor Xa inhibitor, has no commercially available assay to measure its activity and no specific antidote. To date, recommendations for managing bleeding associated with apixaban are based on studies with animal models and healthy volunteers (who do not have identified thrombogenic risk factors) and expert opinion. No clinical experience has been published in the literature. Ideally, apixaban would be reversed sufficiently to stop a perilous bleed without producing more thrombogenic risk than the patients' underlying risk factors. Three-factor prothrombin complex concentrate (PCC3) is the least thrombogenic among the suggested reversal agents. Fresh frozen plasma (FFP) is sometimes recommended to add to PCC3, but it adds considerable volume. We describe successful management of an active left gluteal arterial extravasation due to trauma and associated apixaban, in a patient with aortic stenosis and atrial fibrillation, by administration of PCC3 alone, without the added volume of FFP. PMID:26519251

  4. 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

  5. Anterior Spinal Artery Syndrome: Reversible Paraplegia after Minimally Invasive Spine Surgery

    PubMed Central

    Bredow, J.; Oppermann, J.; Keller, K.; Beyer, F.; Boese, C. K.; Zarghooni, K.; Sobottke, R.; Eysel, P.; Siewe, J.

    2014-01-01

    Background Context. Percutaneous balloon kyphoplasty is an established minimally invasive technique to treat painful vertebral compression fractures, especially in the context of osteoporosis with a minor complication rate. Purpose. To describe the heparin anticoagulation treatment of paraplegia following balloon kyphoplasty. Study Design. We report the first case of an anterior spinal artery syndrome with a postoperative reversible paraplegia following a minimally invasive spine surgery (balloon kyphoplasty) without cement leakage. Methods. A 75-year-old female patient underwent balloon kyphoplasty for a fresh fracture of the first vertebra. Results. Postoperatively, the patient developed an acute anterior spinal artery syndrome with motor paraplegia of the lower extremities as well as loss of pain and temperature sensation with retained proprioception and vibratory sensation. Complete recovery occurred six hours after bolus therapy with 15.000 IU low-molecular heparin. Conclusion. Spine surgeons should consider vascular complications in patients with incomplete spinal cord syndromes after balloon kyphoplasty, not only after more invasive spine surgery. High-dose low-molecular heparin might help to reperfuse the Adamkiewicz artery. PMID:25210639

  6. Anterior spinal artery syndrome: reversible paraplegia after minimally invasive spine surgery.

    PubMed

    Bredow, J; Oppermann, J; Keller, K; Beyer, F; Boese, C K; Zarghooni, K; Sobottke, R; Eysel, P; Siewe, J

    2014-01-01

    Background Context. Percutaneous balloon kyphoplasty is an established minimally invasive technique to treat painful vertebral compression fractures, especially in the context of osteoporosis with a minor complication rate. Purpose. To describe the heparin anticoagulation treatment of paraplegia following balloon kyphoplasty. Study Design. We report the first case of an anterior spinal artery syndrome with a postoperative reversible paraplegia following a minimally invasive spine surgery (balloon kyphoplasty) without cement leakage. Methods. A 75-year-old female patient underwent balloon kyphoplasty for a fresh fracture of the first vertebra. Results. Postoperatively, the patient developed an acute anterior spinal artery syndrome with motor paraplegia of the lower extremities as well as loss of pain and temperature sensation with retained proprioception and vibratory sensation. Complete recovery occurred six hours after bolus therapy with 15.000 IU low-molecular heparin. Conclusion. Spine surgeons should consider vascular complications in patients with incomplete spinal cord syndromes after balloon kyphoplasty, not only after more invasive spine surgery. High-dose low-molecular heparin might help to reperfuse the Adamkiewicz artery. PMID:25210639

  7. First reported revascularization of complex occlusion of the right coronary artery using the IVUS-guided reverse CART technique via a gastroepiploic artery graft.

    PubMed

    Dai, Jian; Katoh, Osamu; Zhou, Hua; Kyo, Eisho

    2016-02-01

    When patients who have previously undergone coronary artery bypass graft surgery develop ischemia symptoms that cannot be controlled by optimal medical therapy, repeat revascularization is indicated. The revascularization strategy should be based on individual clinical and anatomical characteristics. We report here a challenging patient who presented with recurrent stable angina due to worsening of a proximal right coronary artery (RCA) stenosis to chronic total occlusion (CTO) after anastomosis of the right gastroepiploic artery (GEA) to the posterior descending artery. A soft guidewire was advanced through the right GEA collateral channel to the distal end of the CTO, but the dedicated CTO guidewires could not be advanced across the severely calcified CTO using the retrograde wire crossing or kissing wire techniques. The RCA was eventually revascularized by implantation of drug-eluting stents using the intravascular ultrasound-guided reverse controlled antegrade and retrograde subintimal tracking technique. PMID:25148795

  8. Right and Left Ventricular Myocardial Perfusion Reserves Correlate with Right Ventricular Function and Pulmonary Hemodynamics in Patients with Pulmonary Arterial Hypertension1

    PubMed Central

    Skrok, Jan; Shehata, Monda L.; Singh, Sukhminder; Sibley, Christopher T.; Boyce, Danielle M.; Lechtzin, Noah; Girgis, Reda E.; Mathai, Steven C.; Goldstein, Thomas A.; Zheng, Jie; Lima, João A. C.; Bluemke, David A.; Hassoun, Paul M.

    2011-01-01

    Purpose: To evaluate the relationships of right ventricular (RV) and left ventricular (LV) myocardial perfusion reserves with ventricular function and pulmonary hemodynamics in patients with pulmonary arterial hypertension (PAH) by using adenosine stress perfusion cardiac magnetic resonance (MR) imaging. Materials and Methods: This HIPAA-compliant study was institutional review board approved. Twenty-five patients known or suspected to have PAH underwent right heart catheterization and adenosine stress MR imaging on the same day. Sixteen matched healthy control subjects underwent cardiac MR imaging only. RV and LV perfusion values at rest and at adenosine-induced stress were calculated by using the Fermi function model. The MR imaging–derived RV and LV functional data were calculated by using dedicated software. Statistical testing included Kruskal-Wallis tests for continuous data, Spearman rank correlation tests, and multiple linear regression analyses. Results: Seventeen of the 25 patients had PAH: 11 with scleroderma-associated PAH, and six with idiopathic PAH. The remaining eight patients had scleroderma without PAH. The myocardial perfusion reserve indexes (MPRIs) in the PAH group (median RV MPRI, 1.7 [25th–75th percentile range, 1.3–2.0]; median LV MPRI, 1.8 [25th–75th percentile range, 1.6–2.1]) were significantly lower than those in the scleroderma non-PAH (median RV MPRI, 2.5 [25th–75th percentile range, 1.8–3.9] [P = .03]; median LV MPRI, 4.1 [25th–75th percentile range, 2.6–4.8] [P = .0003]) and control (median RV MPRI, 2.9 [25th–75th percentile range, 2.6–3.6] [P < .01]; median LV MPRI, 3.6 [25th–75th percentile range, 2.7–4.1] [P < .01]) groups. There were significant correlations between biventricular MPRI and both mean pulmonary arterial pressure (mPAP) (RV MPRI: ρ = −0.59, Bonferroni P = .036; LV MPRI: ρ = −0.79, Bonferroni P < .002) and RV stroke work index (RV MPRI: ρ = −0.63, Bonferroni P = .01; LV MPRI: ρ =

  9. 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

  10. Role of R-type calcium channels in the response of the perfused arterial and venous mesenteric vasculature of the rat to platelet-activating factor.

    PubMed Central

    Claing, A.; Bkaily, G.; Berthiaume, N.; Sirois, P.; Rola-Pleszczynski, M.; D'Orléans-Juste, P.

    1994-01-01

    1. The vasoactive properties of platelet-activating factor (PAF) were studied in the arterial and venous vasculature of the rat double-perfused mesenteric bed. Although PAF (0.01-0.3 pmol) induced a dose-dependent vasodilatation of the arterial mesenteric vasculature, it triggered only vasoconstrictions on the venous side, with an intact endothelium as bradykinin induced a significant venodilatation. 2. NG-nitro-L-arginine methyl ester (L-NAME, 100 microM), a nitric oxide synthase inhibitor, markedly reduced the vasodilatation induced by PAF in the arterial mesenteric vasculature and potentiated the contractile responses of the venous side to the same agent. 3. The PAF antagonist, WEB-2170, markedly reduced the response to PAF on both sides of the mesenteric vasculature. However, the IC50 of WEB-2170 against PAF was reached at a much higher concentration (1 x 10(-8) M) on the arterial side than on the venous side (5.3 x 10(-11) M). Furthermore, a second antagonist of PAF receptors, SRI-63441, although being less potent on the venous vasculature than WEB-2170, was equipotent in antagonizing the venoconstriction and the arterial dilatation induced by PAF (IC50 of SRI-63441, arterial side: 2.9 x 10(-9) M; venous side: 3.1 x 10(-9) M). 4. The dual L- and R-calcium channel blocker, isradipine (PN 200-110), but not the L-type calcium channel blocker, nifedipine, markedly reduced the PAF-induced vasoactive properties on both sides of the mesenteric vasculature. 5. Our results illustrate the differential vasoactive properties of PAF in the mesenteric vasculature of the rat.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7952882

  11. The reverse sural artery flap for the reconstruction of distal third of the leg and foot.

    PubMed

    Olawoye, Olayinka Adebanji; Ademola, Samuel Adesina; Iyun, Kayode; Michael, Afie; Oluwatosin, Odunayo

    2014-04-01

    Soft tissue defects around the distal third of the leg and the foot present a major reconstructive challenge. There is limited expertise with free tissue transfers in many developing countries, necessitating consideration of other options for the closure of such defects. The versatility and reliability of sural artery flap have made it an emerging popular option for the reconstruction of such defects. Twenty patients comprising of 13 males and 7 females with soft tissue defects of the lower third of the leg and foot requiring soft tissue cover were treated between January 2006 and December 2010. The age range was 7-58 years with a mean age of 30 years. Nineteen (95%) of the defects were post-traumatic while one (5%) was post-infective. All the defects were covered with reversed sural artery flaps, which were raised on the posterior aspect of the junction of the upper and middle third of the leg. The smallest flap was 4 × 4 cm(2) while the largest measured 20 × 12 cm(2). The donor defect was closed directly in 7 (35%) patients, while split skin graft was applied in the remaining 13 (65%) patients. There was satisfactory flap healing in 17 patients (85%), while 3 patients (15%) had complete flap necrosis. Two of these patients had significant comorbidities of haemoglobinopathy and poorly controlled diabetes mellitus. Sural artery flap remains a viable option for the reconstruction of soft tissue defects of the distal third of the leg and foot. Caution should, however, be exercised in patients with some significant systemic diseases. PMID:23050798

  12. Selective enhancement of endothelial BMPR-II with BMP9 reverses pulmonary arterial hypertension

    PubMed Central

    Long, Lu; Ormiston, Mark L.; Yang, Xudong; Southwood, Mark; Gräf, Stefan; Machado, Rajiv D.; Mueller, Matthias; Kinzel, Bernd; Yung, Lai Ming; Wilkinson, Janine M.; Moore, Stephen D.; Drake, Kylie M.; Aldred, Micheala A.; Yu, Paul; Upton, Paul D.; Morrell, Nicholas W.

    2015-01-01

    Genetic evidence implicates the loss of bone morphogenetic protein type II receptor (BMPR-II) signaling in the endothelium as an initiating factor in pulmonary arterial hypertension (PAH). However, selective targeting of this signaling pathway using BMP ligands has not yet been explored as a therapeutic strategy. We identified BMP9 as the preferred ligand for preventing apoptosis and enhancing monolayer integrity in both pulmonary arterial endothelial cells and blood outgrowth endothelial cells from subjects with PAH bearing mutations in BMPR-II. In vivo, we report the spontaneous generation of PAH in a mouse model bearing a heterozygous knock-in of a human BMPR-II mutation, R899X. Administration of BMP9 reversed established PAH in Bmpr2+/R899X mice, as well as in models of disease developed in response to either monocrotaline or VEGF receptor inhibition combined with chronic hypoxia. These results demonstrate the promise of direct enhancement of endothelial BMP signaling as a novel therapeutic strategy for PAH. PMID:26076038

  13. 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

  14. 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

    2016-01-01

    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

  15. Quantitative Upright–Supine High-Speed SPECT Myocardial Perfusion Imaging for Detection of Coronary Artery Disease: Correlation with Invasive Coronary Angiography

    PubMed Central

    Nakazato, Ryo; Tamarappoo, Balaji K.; Kang, Xingping; Wolak, Arik; Kite, Faith; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Berman, Daniel S.; Slomka, Piotr J.

    2011-01-01

    A recently developed camera system for high-speed SPECT (HS-SPECT) myocardial perfusion imaging shows excellent correlation with conventional SPECT. Our goal was to test the diagnostic accuracy of an automated quantification of combined upright and supine myocardial SPECT for detection of coronary artery disease (CAD) (≥70% luminal diameter stenosis or, in left main coronary artery, ≥50% luminal diameter stenosis) in comparison to invasive coronary angiography (ICA). Methods We studied 142 patients undergoing upright and supine HS-SPECT, including 56 consecutive patients (63% men; mean age 6 ± SD, 64 ± 13 y; 45% exercise stress) without known CAD who underwent diagnostic ICA within 6 mo of HS-SPECT and 86 consecutive patients with a low likelihood of CAD. Reference limits for upright and supine HS-SPECT were created from studies of patients with a low likelihood of CAD. Automated software adopted from supine–prone analysis was used to quantify the severity and extent of perfusion abnormality and was expressed as total perfusion deficit (TPD). TPD was obtained for upright (U-TPD), supine (S-TPD), and combined upright–supine acquisitions (C-TPD). Stress U-TPD ≥ 5%, S-TPD ≥ 5%, and C-TPD ≥ 3% myocardium were considered abnormal for per-patient analysis, and U-TPD, S-TPD, and C-TPD ≥ 2% in each coronary artery territory were considered abnormal for per-vessel analysis. Results On a per-patient basis, the sensitivity was 91%, 88%, and 94% for U-TPD, S-TPD, and C-TPD, respectively, and specificity was 59%, 73%, and 86% for U-TPD, S-TPD, and C-TPD, respectively. C-TPD had a larger area under the receiver-operating-characteristic curve than U-TPD or S-TPD for identification of stenosis ≥ 70% (0.94 vs. 0.88 and 0.89, P < 0.05 and not significant, respectively). On a per-vessel basis, the sensitivity was 67%, 66%, and 69% for U-TPD, S-TPD, and C-TPD, respectively, and specificity was 91%, 94%, and 97% for U-TPD, S-TPD, and C-TPD, respectively (P = 0

  16. Normalization of reverse redistribution of thallium-201 with procainamide pretreatment in Wolff-Parkinson-White syndrome

    SciTech Connect

    Nii, T.; Nakashima, Y.; Nomoto, J.; Hiroki, T.; Ohshima, F.; Arakawa, K. )

    1991-03-01

    Stress thallium-201 myocardial perfusion imaging was performed in a patient with Wolff-Parkinson-White syndrome. Reverse redistribution phenomenon was observed in the absence of coronary artery disease. This seems to be the first report of normalization of this phenomenon in association with reversion of accessory pathway to normal atrioventricular conduction after pretreatment with procainamide.

  17. 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. PMID:26031202

  18. 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

  19. Adrenocorticotropin reverses vascular dysfunction and protects against splanchnic artery occlusion shock

    PubMed Central

    Squadrito, Francesco; Guarini, Salvatore; Altavilla, Domenica; Squadrito, Giovanni; Campo, Giuseppe M; Arlotta, Mariarita; Quartarone, Cristina; Saitta, Antonino; Cucinotta, Domenico; Bazzani, Carla; Cainazzo, Maria M; Mioni, Chiara; Bertolini, Alfio; Caputi, Achille P

    1999-01-01

    Tumour necrosis factor (TNF-α) is involved in the pathogenesis of splanchnic artery occlusion (SAO) shock. On the other hand, inhibition of TNF-α is an important component of the mechanism of action of melanocortins in reversing haemorrhagic shock. We therefore investigated the effects of the melanocortin peptide ACTH-(1–24) (adrenocorticotropin fragment 1–24) on the vascular failure induced by SAO shock.SAO-shocked rats had a decreased survival rate (0% at 4 h of reperfusion, while sham-shocked rats survived for more than 4 h), enhanced serum TNF-α concentrations (755±81 U ml−1), decreased mean arterial blood pressure, leukopenia, and increased ileal leukocyte accumulation, as revealed by means of myeloperoxidase activity (MPO=9.4±1 U g−1 tissue). Moreover, aortic rings from shocked rats showed a marked hyporeactivity to phenylephrine (PE, 1 nM–10 μM) (Emax and ED50 in shocked rats=7.16 mN mg−1 tissue and 120 nM, respectively; Emax and ED50 in sham-shocked rats=16.31 mN mg−1 tissue and 100 nM, respectively), reduced responsiveness to acetylcholine (ACh, 10 nM-10 μM) (Emax and ED50 in shocked rats=30% relaxation and 520 nM, respectively; Emax and ED50 in sham-shocked rats=82% relaxation and 510 nM, respectively) and increased staining for intercellular adhesion molecule-1 (ICAM-1).ACTH-(1–24) [160 μg kg−1 intravenously (i.v.), 5 min after SAO] increased survival rate [SAO+ACTH-(1–24)=80% at 4 h of reperfusion], reversed hypotension, reduced serum TNF-α (55±13 U ml−1), ameliorated leukopenia, reduced ileal MPO (1.2±0.2 U g−1 tissue), restored the reactivity to PE, improved the responsiveness to ACh and blunted the enhanced immunostaining for ICAM-1 in the aorta.Adrenalectomy only in part–but not significantly–reduced the ACTH-induced shock reversal, the survival rate of SAO+ACTH-(1–24) adrenalectomized rats being 60% at 4 h of reperfusion; and methylprednisolone (80

  20. An a contrario approach for the detection of patient-specific brain perfusion abnormalities with arterial spin labelling.

    PubMed

    Maumet, Camille; Maurel, Pierre; Ferré, Jean-Christophe; Barillot, Christian

    2016-07-01

    In this paper, we introduce a new locally multivariate procedure to quantitatively extract voxel-wise patterns of abnormal perfusion in individual patients. This a contrario approach uses a multivariate metric from the computer vision community that is suitable to detect abnormalities even in the presence of closeby hypo- and hyper-perfusions. This method takes into account local information without applying Gaussian smoothing to the data. Furthermore, to improve on the standard a contrario approach, which assumes white noise, we introduce an updated a contrario approach that takes into account the spatial coherency of the noise in the probability estimation. Validation is undertaken on a dataset of 25 patients diagnosed with brain tumours and 61 healthy volunteers. We show how the a contrario approach outperforms the massively univariate general linear model usually employed for this type of analysis. PMID:27039702

  1. Adjunctive treatment with ticagrelor, but not clopidogrel, added to tPA enables sustained coronary artery recanalisation with recovery of myocardium perfusion in a canine coronary thrombosis model.

    PubMed

    Wang, Kai; Zhou, Xiaorong; Huang, Yanming; Khalil, Mazen; Wiktor, Dominik; van Giezen, J J J; Penn, Marc S

    2010-09-01

    Reperfusion therapy for myocardial infarction is limited by significant re-occlusion rates and less-than-optimal myocardial tissue perfusion. It was the objective of this study to assess and compare the effect of ticagrelor, the first reversibly binding oral P2Y12 receptor antagonist, with that of clopidogrel, in conjunction with thrombolytic therapy, on platelet aggregation, thrombus formation, and myocardial perfusion in a canine model. Thrombus formation was induced by electrolytic injury and blood flow was measured with a Doppler ultrasonic flowmeter. All animals received tissue plasminogen activator (tPA) (1 mg/kg over 20 min); 10 animals received clopidogrel (10 mg/kg IV bolus over 5 min), 10 animals received ticagrelor initiated with a 1-min bolus (75 microg/kg/min), followed by continuous infusion (10 microg/kg/min) for 2 h, and 10 animals received IV saline. Re-occlusion rate and cyclic flow variation decreased with ticagrelor compared to saline groups (p<0.05). Adenosine phosphate (ADP)-induced platelet aggregation decreased with ticagrelor (1.9% +/- 2.67) and clopidogrel (1.11% +/- 2.0) vs. saline (26.3% +/- 23.5, p<0.05) at the end of adjunctive therapy. Bleeding time increased in the clopidogrel compared to the ticagrelor group (p=0.01). Infarct size was reduced with ticagrelor compared to the clopidogrel and saline groups (p<0.05). Blood flow remained significantly below baseline values at 20 min after tPA administration in the saline and clopidogrel groups but not in the ticagrelor group. In conclusion, in a dog coronary thrombosis model, ticagrelor blocks ADP-induced platelet activation and aggregation; prevents platelet-mediated thrombosis; prolongs reperfusion time and reduces re-occlusion and cyclic flow variation; and significantly decreases infarct size and rapidly restores myocardial tissue perfusion. PMID:20694285

  2. Pharmacologic analysis of 7-O-ethyl-fangchinoline-induced vasodilation properties in isolated perfused common carotid arteries of Wistar Kyoto rats and spontaneously hypertensive rats.

    PubMed

    Matsuura, M; Zenda, H; Chiba, S

    1991-10-01

    Using the cannula insertion method, we investigated vascular effects of 7-O-ethyl-fangchinoline (TJN-220) derived from tetrandrine in isolated and perfused common carotid arteries of Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). A single dose of TJN-220 caused a vasodilation in a dose-related manner in arteries preconstricted by phenylephrine. The vasodilation was not inhibited by propranolol, a potent beta-adrenoceptor antagonist. A potent alpha-antagonist bunazosin inhibited the vasoconstriction to norepinephrine while TJN-220 did not modify the norepinephrine-induced constriction, indicating TJN-220 had no alpha-blocking activity. A potent calcium entry blocker, diltiazem, markedly attenuated the KCl-induced vasoconstriction, and TJN-220 slightly but significantly attenuated the KCl-induced one in large doses. The vasodilation of TJN-220 was not abolished after removing the endothelium by an intraluminal administration of saponin, although the ACh-induced dilation was completely abolished by it. A comparison of vascular responses in WKY and SHR revealed no significant differences. From these results, it is concluded that 1) a new tetrandrine derivative, TJN-220 has relatively long-lasting vasorelaxant properties, 2) the dilatory effects might not be related to adrenergic, muscarinic or endothelium-dependent mechanisms, and 3) the effects might partially be due to calcium entry antagonistic properties. PMID:1806292

  3. Endothelial cells derived from human iPSCs increase capillary density and improve perfusion in a mouse model of peripheral arterial disease

    PubMed Central

    Jalil, Rufaihah Abdul; Huang, Ngan F; Jame, Sina; Lee, Jerry; Nguyen, Ha N; Byers, Blake; De, Abhijit; Okogbaa, Janet; Rollins, Mark; Reijo-Pera, Renee; Gambhir, Sanjiv S; Cooke, John P

    2011-01-01

    Objective Stem cell therapy for angiogenesis and vascular regeneration has been investigated using adult or embryonic stem cells. In the present study, we investigated the potential of endothelial cells (ECs) derived from human induced pluripotent stem cells (hiPSCs) to promote the perfusion of ischemic tissue in a murine model of peripheral arterial disease. Methods and Results Endothelial differentiation was initiated by culturing hiPSCs for 14 days in differentiation media supplemented with BMP-4 and VEGF. The hiPSC-ECs exhibited endothelial characteristics by forming capillary-like structures in matrigel and incorporating acetylated-LDL. They stained positively for EC markers such as KDR, CD31, CD144 and eNOS. In vitro exposure of hiPSC-ECs to hypoxia resulted in increased expression of various angiogenic related cytokines and growth factors. hiPSC-ECs were stably transduced with a double fusion construct encoded by the ubiquitin promoter, firefly luciferase for bioluminescence imaging (BLI) and green fluorescence protein (GFP) for fluorescent detection (pUb-Fluc-GFP). The hiPSC-ECs (5×105) were delivered by intramuscular injection into the ischemic hindlimb of SCID mice at day 0 and again on day 7 after femoral artery ligation (n=8). BLI showed that hiPSC-ECs survived in the ischemic limb for at least 2 weeks. In addition, laser Doppler imaging showed that the ratio of blood perfusion was increased by hiPSC-EC treatment by comparison to the saline-treated group (0.58±0.12 vs 0.44±0.04; P=0.005). The total number of capillaries in the ischemic limb of mice receiving hiPSC-EC injections was greater than those in the saline-treated group (1284 ±155 vs. 797±206 capillaries/mm2) (P<0.002). Conclusion This study is a first step toward development of a regenerative strategy for peripheral arterial disease based on the use of ECs derived from hiPSCs. PMID:21836062

  4. 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

  5. Prognostic value of normal regadenoson stress perfusion cardiovascular magnetic resonance

    PubMed Central

    2013-01-01

    Background Regadenoson is a vasodilator stress agent that selectively activates the A2A receptor. Compared to adenosine, regadenoson is easier to administer and results in fewer side effects. Although extensively studied in patients undergoing nuclear perfusion imaging (MPI), its use for perfusion cardiovascular magnetic resonance (CMR) is not well described. The aim of this study was to determine the prognostic value of a normal regadenoson perfusion CMR in patients with known or suspected coronary artery disease. Methods Patients with known or suspected coronary artery disease were prospectively enrolled to receive perfusion CMR (Philips 1.5 T) with regadenoson. Three short-axis slices of the left ventricle (LV) were obtained during first pass of contrast using a hybrid GRE-EPI pulse sequence (0.075 mmol/kg Gadolinium-DTPA-BMA at 4 ml/sec). Imaging was performed 1 minute after injection of regadenoson (0.4 mg) and repeated 15 minutes after reversal of hyperemia with aminophylline (125 mg). Perfusion defects were documented if they persisted for ≥2 frames after peak enhancement of the LV cavity. CMR was considered abnormal if there was a resting wall motion abnormality, decreased LVEF (<40%), presence of LGE, or the presence of a perfusion defect during hyperemia. All patients were followed for a minimum of 1 year for major adverse cardiovascular event (MACE) defined as coronary revascularization, non-fatal myocardial infarction, and cardiovascular death. Results 149 patients were included in the final analysis. Perfusion defects were noted in 43/149 (29%) patients; 59/149 (40%) had any abnormality on CMR. During the mean follow-up period of 24 ± 9 months, 17/149 (11.4%) patients experienced MACE. The separation in the survival distributions for those with perfusion defects and those without perfusion defects was highly significant (log-rank p = 0.0001). When the absence of perfusion defects was added to the absence of other resting CMR

  6. Cardiac effects of the extract and active components of radix stephaniae tetrandrae. II. Myocardial infarct, arrhythmias, coronary arterial flow and heart rate in the isolated perfused rat heart.

    PubMed

    Yu, X C; Wu, S; Wang, G Y; Shan, J; Wong, T M; Chen, C F; Pang, K T

    2001-05-11

    The primary purpose of the present study was to compare the cardioprotective effects of the extract from radix stephaniae tetrandrae (RST) and its individual compounds, tetrandrine (Tet) and fanchinoline (Fan). Secondly, we also compared the cardiac effects of the individual compounds and the RST extract with those of verapamil, a classical Ca2+ channel blocker. The Langendorff isolated perfused rat heart preparation was used. Regional ischaemia and reperfusion was employed to induce myocardial infarct and arrhythmia. Infarct, arrhythmia, heart rate and coronary artery flow were determined in hearts treated with vehicle, RST extract, Tet, Fan, or verapamil. It was found that RST extract, of which only 9% was Tet, and Tet alone produced equally potent ameliorating effects on arrhythmia and infarct induced by ischaemia and reperfusion without further inhibiting ischaemia-reduced heart rate and coronary artery flow. Fan had no effects on arrhythmia and infarct induced by ischaemia and reperfusion; but it induced S-T segment elevation and further reduced heart rate and coronary artery flow during ischaemia. Verapamil also ameliorated the effects of ischaemia and reperfusion on arrhythmia and infarct. It should be noted that 1 microM verapamil, that produced comparable effects on infarct and arrhythmia to the RST extract and Tet, further inhibited heart rate during ischaemia. The results indicate that the RST extract produces equally potent cardioprotective and anti-arrhythmic effects as Tet alone. Both RST extract and Tet may be better choices for the treatment of arrhythmia and infarct induced by myocardial ischaemia and reperfusion than the classical Ca2+ channel blocker, verapamil as they do not further reduce heart rate during ischaemia. PMID:11432452

  7. Prognostic Value of Major Cardiac Event Risk Score Estimated With Gated Myocardial Perfusion Imaging in Japanese Patients With Coronary Artery Disease.

    PubMed

    Yoda, Shunichi; Nakanishi, Kanae; Tano, Ayako; Hori, Yusuke; Hayase, Misa; Mineki, Takashi; Suzuki, Yasuyuki; Matsumoto, Naoya; Hirayama, Atsushi

    2016-07-27

    We published a cardiac event risk score (CERS) predicting the risk of major cardiac events (MCEs) within 3 years. The purpose of this study was to verify the prognostic value of the CERS before and after treatment in Japanese patients with coronary artery disease.We retrospectively investigated 612 patients who underwent rest (201)Tl and stress (99m)Tc-tetrofosmin myocardial perfusion single photon emission computed tomography (SPECT) between October 2004 and March 2013 and who had a significant stenosis with ≥ 75% narrowing of the arterial diameter detected by coronary angiography performed after confirmation of ≥ 5% ischemia with the SPECT. The patients underwent treatment including revascularization and medication, and thereafter, were re-evaluated with SPECT during a chronic phase and followed-up to confirm prognosis for ≥ 1 year. The endpoint was the onset of MCEs during the follow-up.During the follow-up (36.7 ± 14.5 months), 50 patients (8.7%) experienced MCEs comprising cardiac death (n = 16), non-fatal myocardial infarction (n = 4), and unstable angina pectoris (n = 30). The multivariate Cox proportional hazards regression model analysis for the actual occurrence of MCEs showed the summed difference score % and MCE risks estimated with the CERS after treatment to be significant independent variables. Ischemic reduction after treatment contributed significantly to a decrease in the MCE risks. The MCE risks estimated with the CERS after treatment were generally consistent with the incidence of the MCEs actually observed.The CERS after treatment is a valuable formula for predicting prognosis in Japanese patients with coronary artery disease. PMID:27357436

  8. Non-nucleoside reverse transcriptase inhibitor efavirenz increases monolayer permeability of human coronary artery endothelial cells.

    PubMed

    Jamaluddin, Md Saha; Lin, Peter H; Yao, Qizhi; Chen, Changyi

    2010-01-01

    Highly active antiretroviral therapy (HAART) is often associated with endothelial dysfunction and cardiovascular complications. In this study, we determined whether HIV non-nucleoside reverse transcriptase inhibitor efavirenz (EFV) could increase endothelial permeability. Human coronary artery endothelial cells (HCAECs) were treated with EFV (1, 5 and 10 microg/ml) and endothelial permeability was determined by a transwell system with a fluorescence-labeled dextran tracer. HCAECs treated with EFV showed a significant increase of endothelial permeability in a concentration-dependent manner. With real time PCR analysis, EFV significantly reduced the mRNA levels of tight junction proteins claudin-1, occludin, zonula occluden-1 and junctional adhesion molecule-1 compared with controls (P<0.05). Protein levels of these tight junction molecules were also reduced substantially in the EFV-treated cells by western blot and flow cytometry analyses. In addition, EFV also increased superoxide anion production with dihydroethidium and cellular glutathione assays, while it decreased mitochondrial membrane potential with JC-staining. Antioxidants (ginkgolide B and MnTBAP) effectively blocked EFV-induced endothelial permeability and mitochondrial dysfunction. Furthermore, EFV increased the phosphorylation of MAPK JNK and IkappaBalpha, thereby increasing NFkappaB translocation to the nucleus. Chemical JNK inhibitor and dominant negative mutant JNK and IkappaBalpha adenoviruses effectively blocked the effects of EFV on HCAECs. Thus, EFV increases endothelial permeability which may be due to the decrease of tight junction proteins and the increase of superoxide anion. JNK and NFkappaB activation may be directly involved in the signal transduction pathway of EFV action in HCAECs. PMID:19674747

  9. [Coronary artery disease, myocardial perfusion and ventricular function in Q-wave and non-Q-wave myocardial infarcts].

    PubMed

    Macieira-Coelho, E; Garcia-Alves, M; da Costa, B; Cantinho, G; Pedro, P; Dionisio, I; Gouveia, A; de Padua, F

    1997-04-01

    Controversy remains in considering non-Q wave myocardial infarction (NQMI) a distinct pathophysiological entity of Q wave myocardial infarction (QMI). In order to analyze the severity of coronary artery disease, extension of myocardial scar or myocardial ischemia and ventricular function, 78 consecutive patients with QMI and 32 with NQMI, mean age 55.4 +/- 8.5, not submitted to thrombolytic therapy, were studied. Coronary angiography, exercise thallium scintigraphy and radionuclide ventriculography were performed in all at least within 3 months of a prior myocardial infarction. In the present study the occurrence of QMI was significantly more frequent in older patients than NQMI. There was no prevalence of occlusion either in the right, left circumflex or left anterior descending coronary arteries in both groups. Ejection fraction, degree of occlusion and presence of collateral circulation showed an equal prevalence in QMI and NQMI patients. A higher incidence of multivessel disease was found in NQMI that had less necrosis than QMI patients. The prevalence of exercise induced thallium-201 redistribution defects within the infarct zone was substantially higher and involved more scar segments in NQMI patients. Physiological and clinical consequences of coronary thrombosis depends on the size and the number of diseased arteries, the approach the pathophysiologic consequences of coronary disease in terms of fractal structure has been suggested. A pronounced heterogeneity in regional myocardial blood flow in a fractal branching arterial network may be responsible for the pathophysiologic differences of coronary thrombosis between Q-wave and non Q-wave infarction. PMID:9341032

  10. 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

  11. Perfusion-CT compared to H215O/O15O PET in Patients with Chronic Cervical Carotid Artery Occlusion

    PubMed Central

    Kamath, Amita; Smith, Wade S.; Powers, William J.; Cianfoni, Alessandro; Chien, Jeffrey D.; Videen, Tom; Lawton, Michael T.; Finley, Bruce; Dillon, William P.; Wintermark, Max

    2008-01-01

    Background and Purpose As part of the Carotid Occlusion Surgery Study (COSS), patients with chronic cervical carotid artery occlusive disease are selected for extracranial-intracranial bypass surgery based on the results of 15O2/H215O PET imaging. The purpose of this study was to compare the results of Perfusion-CT (PCT) with those of 15O2/H215O PET in a subset of COSS patients. Materials & Methods Six patients enrolled in COSS underwent a standard-of-care PCT in addition to the 15O2/H215O PET study used for determining study eligibility. PCT and PET studies were coregistered and then processed separately by different radiologists. Relative measurement of cerebral blood flow (CBF) and oxygen extraction fraction (OEF) without arterial sampling were calculated from two PET scans, one for O15O inhalation and one for H215O injection. PCT datasets were processed using different arterial input functions (AIF), on the side of the carotid occlusion (“ischemic” inputs) and on the contralateral side (“nonischemic” inputs). The same sets of symmetric regions of interests (anterior, middle and posterior cerebral artery distribution) were drawn on both hemispheres on matching slices from both imaging modalities (PCT and PET). Relative PCT and PET CBF values (“ischemic” side divided by “nonischemic” side) were compared using linear regression model, in order to determine the most appropriate arterial input function for PCT. As a secondary analysis, PCT values of relative CBF, cerebral blood volume (CBV) and mean transit time (MTT) using the most accurate arterial input function were evaluated for linear regression with respect to relative PET OEF values, which are used for determining study eligibility in COSS. Results The most accurate PCT relative CBF maps with respect to the gold standard PET CBF, were obtained when CBF values for each arterial territory are calculated using a dedicated AIF for each territory (ACA AIF for ACA territory, right MCA AIF for right

  12. UTP induces vascular responses in the isolated and perfused canine epicardial coronary artery via UTP-preferring P2Y receptors

    PubMed Central

    Matsumoto, Takako; Nakane, Tokio; Chiba, Shigetoshi

    1997-01-01

    Vasoconstrictor responses of the isolated and perfused canine epicardial coronary artery to uridine 5′-triphosphate (UTP) were analysed pharmacologically. At basal perfusion pressure, UTP induced vasoconstriction in a dose-related manner and the vasoconstriction was sometimes followed by a slight vasodilatation at large doses (more than 10 nmol). The rank order of potency for vasoconstriction was UTP=UDP>ATP>TTP⩾ITP>> UMP. At raised perfusion pressure by 20 mM KCl, the vasoconstriction was not changed and a small vasodilatation was induced at large doses. The rank order of potency for vasodilatation was induced at large doses. The rank order of potency for vasodilatation was ATP>>ITP⩾UDP>UTP⩾TTP. The maximal vasodilator response to UTP was much less than that to ATP. UMP did not induce vasodilatation. The P2X receptor agonist and desensitizing agent α,β-methylene ATP (1 μM) and the P2 receptor antagonist suramin (100 μM) inhibited the vasoconstrictor responses to ATP but not those to UTP and UDP. The P2 receptor antagonist reactive blue 2 (30 μM) did not inhibit the vascular responses to UTP. UTP (200 μM) desensitized the vasoconstrictor responses to UTP, but not either the vasodilator responses to UTP or the vasoconstrictor responses to ATP and UDP. UDP (200 μM) did not desensitize the vascular responses to UTP. Preincubating the UDP stock solution and arterial preparation with hexokinase (10 and 1 uml−1, respectively) did not change the vasoconstrictor responses to UDP. The Ca channel blocker diltiazem (1 μM) inhibited the vasoconstrictor responses to UTP but not those to ATP and UDP. Incubation in a Ca2+-free solution containing 1 mM EGTA inhibited the vascular responses to ATP, UTP and UDP. Removal of the endothelium by an intraluminal injection of saponin (1 mg) inhibited the vasodilator responses to UTP. Indomethacin, a cyclo-oxygenase inhibitor (1 μM), inhibited the vasodilator responses to UTP, but NG

  13. Reverse sural artery flap for the reconstruction of chronic lower extremity wounds in high-risk patients.

    PubMed

    Morgan, Kenneth; Brantigan, Charles O; Field, Cameron Joseph; Paden, Matthew

    2006-01-01

    Soft tissue defects in patients with chronic comorbidities place these patients at high risk for amputation, even when their underlying problems are controlled. The reverse sural artery flap is an effective technique for closing these defects and saving the limb. We retrospectively reviewed 15 consecutive high-risk patients who underwent a sural artery flap procedure between 2003 and 2005 as a final attempt to prevent having a below-the-knee amputation. All of our patients presented with at least 1 comorbidity, with a majority having multiple. Comorbidities in our patient population consisted primarily of diabetes mellitus with neuropathy, critical limb ischemia, end-stage renal disease, and various cardiomyopathies. All patients presented before surgical intervention with a longstanding history of chronic ulcerations that had failed multiple healing strategies. Ulcerations were located at various regions of the foot and ankle such as the heel, lateral malleolus, medial malleolus, and the lateral midfoot. Of those 15 procedures, three failed completely and two had complete dermal necrosis with viable adipose tissue that healed secondarily. The remaining ten flaps healed primarily. We used negative pressure therapy preoperatively in seven patients and postoperatively in five patients. We obtained a success rate of 80%. The reverse sural artery flap has many advantages over free flaps, which has made it a viable treatment option in chronic ulcerations that have failed conservative attempts. PMID:17145467

  14. 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.

  15. Condition at birth of infants with previously absent or reverse umbilical artery end-diastolic flow velocities.

    PubMed

    Weiss, E; Ulrich, S; Berle, P

    1992-01-01

    In a case control study we assessed 47 fetuses with absent or reverse end-diastolic flow velocities (AREDFV) of the umbilical artery with respect to the mode of delivery, fetal acidosis, and abnormal neurological evaluations at the time of discharge from the department of pediatrics. We also studied a control group which was matched for gestational age and had normal umbilical artery flow velocity waveforms. Fetuses with AREDFV were delivered almost exclusively by cesarean section which was usually done for fetal distress. The number of fetuses with abnormal neurological signs was significantly increased compared to the control group. Fetuses with AREDFV showed an increased incidence of fetal acidosis. Forty per cent of these fetuses were delivered within one day of the first abnormal flow measurement; Sixty per cent were observed clinically for up to four weeks before delivery. PMID:1417086

  16. 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.

  17. 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. PMID:22806318

  18. The Concordance between Myocardial Perfusion Imaging and Coronary Angiography in Detecting Coronary Artery Disease: A Retrospective Study in a Tertiary Cardiac Center at King Abdullah Medical City

    PubMed Central

    Aboul-Enein, Fatma; Alharthi, Hail T.

    2016-01-01

    Background. Coronary artery disease (CAD) is considered as the leading cause of the cardiovascular fatalities worldwide. CAD is diagnosed by many modalities of imaging such as myocardial perfusion imaging (MPI) and coronary angiography (CAG). Methods. A retrospective cross-sectional study was conducted that included all patients referred to the KAMC (King Abdullah Medical City) nuclear cardiology lab from its opening until the end of May 2014 (a period of 17 months). A total of 228 patient reports with a history of conducting either CAG or MPI or both were used in this study and statistically analyzed. Results. An analysis of the MPI results revealed that 78.5% of the samples were abnormal. On the other hand, 26.75% of the samples revealed that they were subjected to CAG and MPI. There was a significant and fair agreement between MPI and CAG by using all the agreement coefficients (kappa = 0.237, phi = 0.310, and P value = 0.043). The sensitivity, specificity, and accuracy of MPI with reference to CAG were 97.8%, 20%, and 78.69%, respectively. In addition, positive predictive and negative predictive values were 78.95% and 75%, respectively. Conclusion. In a tertiary referral center, there was a significant agreement between MPI and CAG and a high accuracy of MPI. MPI was a noninvasive diagnostic test that could be used as a gatekeeper for CAG. PMID:27429833

  19. 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.

  20. Occipital artery-to-posterior inferior cerebellar artery anastomosis with multiple-layer dissection of suboccipital muscles under a reverse C-shaped skin incision.

    PubMed

    Katsuno, Makoto; Tanikawa, Rokuya; Uemori, Genki; Kawasaki, Kazutsune; Izumi, Naoto; Hashimoto, Masaaki

    2015-06-01

    Although occipital artery (OA)-to-posterior inferior cerebellar artery (PICA) anastomosis is the most familiar reconstruction for posterior cerebral circulation, the procedure is considered difficult because of the anatomical complex course of OA and the depth of the operative field at the anastomosis site. Therefore, we attempted a safe and reliable method for OA-to-PICA anastomosis under multiple-layer dissection of suboccipital muscles and a reverse C-shaped skin incision. We reviewed the clinical records of patients who underwent OA-to-PICA anastomosis in our institute, and report the outcome with special emphasis on graft patency and surgical complications. Nine patients are described. In one patient the bypass was accomplished at the cortical segment of the PICA and in all others at the caudal loop. The average time for de-clamping the PICA was 29 min and 29 s. Although the overall graft patency rate was 100%, one patient showed a new medulla infarction at the time of post-operatory three-dimensional computed tomography angiography. Besides a secure OA-to-PICA anastomosis, this technique allows safe harvest of the OA and the creation of a shallow and wide anastomosis field. PMID:25633907

  1. Hydrostatic determinants of cerebral perfusion

    SciTech Connect

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

    1986-05-01

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

  2. 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.

  3. [Effect of changes in airway pressure and the inspiratory volume on the fluid filtration rate and pulmonary artery pressure in isolated rabbit lungs perfused with blood and acellular solution].

    PubMed

    Crespo, Astrid; Novoa, Eva; Urich, Daniela; Trejo, Humberto; Pezzulo, Alejandro; Sznajder, Jacob I; Livia, Fernández; Sánchez-de León, Roberto

    2006-12-01

    It has been reported that ventilation with large tidal volumes causes pulmonary edema in rats by the stimulation and release of proinflammatory mediators. Our objective was to determine the level at which volutrauma induced by changes in Airway Pressure (PAW) and Inspiratory Volume (VI) produce significant changes on the Fluid Filtration Rate (FFR) and Pulmonary Artery Pressure (PAP) in lungs perfused with blood (cellular groups) or with a buffer-albumin solution (acellular groups), with a Positive End Expiratory Pressure (PEEP) 0 or 2 cmH2O and to study the effect of a vasodilator with antiinflammatory properties (fenoterol) in blood-perfused groups. Three experimental groups were used: the cellular groups studied the effect of increased PAW and IV in isolated lungs perfused with blood and PEEP 0 and 2; the acellular groups studied the increased PAW and IV in isolated lungs perfused with a buffer-albumin solution and PEEP 0 and 2; The fenoterol group studied the effect of increased PAW and IV in isolated lungs perfused with blood + fenoterol and PEEP 2. The results show that an increase of FFR is produced earlier in acellular groups than in cellular ones and that the damage in cellular groups is microscopically and macroscopically inferior when compared to acellular groups. Fenoterol did not inhibit edema formation, and that PEEP 2, both in the cellular and the acellular groups, has a protective effect. We propose the possible existence of mediators with protective effects against the formation of pulmonary edema in the blood. These data suggest that volutrauma induced pulmonary edema has a predominantly traumatic origin when the lungs are perfused with blood. PMID:17176901

  4. Automatic detection of coronary artery disease in myocardial perfusion SPECT using image registration and voxel to voxel statistical comparisons.

    PubMed

    Peace, R A; Staff, R T; Gemmell, H G; McKiddie, F I; Metcalfe, M J

    2002-08-01

    The purpose of this study was to compare the performance of automatic detection of coronary artery disease (CAD) with that of expert observers. A male and female normal image template was constructed from normal stress technetium-99m single photon emission computed tomography (SPECT) studies. Mean and standard deviation images for each sex were created by registering normal studies to a standard shape and position. The test group consisted of 104 patients who had been routinely referred for SPECT and angiography. The gold standard for CAD was defined by angiography. The test group studies were registered to the respective templates and the Z-score was calculated for each voxel. Voxels with a Z-score greater than 5 indicated the presence of CAD. The performance of this method and that of three observers were compared by continuous receiver operating characteristic (CROC) analysis. The overall sensitivity and specificity for automatic detection were 73% and 92%, respectively. The area (Az) under the CROC curve (+/-1 SE) for automatic detection of CAD was 0.88+/-0.06. There was no statistically significant difference between the performances of the three observers in terms of Az and that of automatic detection (P> or =0.25, univariate Z-score test). The use of this automated statistical mapping approach shows a performance comparable with experienced observers, but avoids inter-observer and intra-observer variability. PMID:12124485

  5. Testing the hypothesis of neurodegeneracy in respiratory network function with a priori transected arterially perfused brain stem preparation of rat.

    PubMed

    Jones, Sarah E; Dutschmann, Mathias

    2016-05-01

    Degeneracy of respiratory network function would imply that anatomically discrete aspects of the brain stem are capable of producing respiratory rhythm. To test this theory we a priori transected brain stem preparations before reperfusion and reoxygenation at 4 rostrocaudal levels: 1.5 mm caudal to obex (n = 5), at obex (n = 5), and 1.5 (n = 7) and 3 mm (n = 6) rostral to obex. The respiratory activity of these preparations was assessed via recordings of phrenic and vagal nerves and lumbar spinal expiratory motor output. Preparations with a priori transection at level of the caudal brain stem did not produce stable rhythmic respiratory bursting, even when the arterial chemoreceptors were stimulated with sodium cyanide (NaCN). Reperfusion of brain stems that preserved the pre-Bötzinger complex (pre-BötC) showed spontaneous and sustained rhythmic respiratory bursting at low phrenic nerve activity (PNA) amplitude that occurred simultaneously in all respiratory motor outputs. We refer to this rhythm as the pre-BötC burstlet-type rhythm. Conserving circuitry up to the pontomedullary junction consistently produced robust high-amplitude PNA at lower burst rates, whereas sequential motor patterning across the respiratory motor outputs remained absent. Some of the rostrally transected preparations expressed both burstlet-type and regular PNA amplitude rhythms. Further analysis showed that the burstlet-type rhythm and high-amplitude PNA had 1:2 quantal relation, with burstlets appearing to trigger high-amplitude bursts. We conclude that no degenerate rhythmogenic circuits are located in the caudal medulla oblongata and confirm the pre-BötC as the primary rhythmogenic kernel. The absence of sequential motor patterning in a priori transected preparations suggests that pontine circuits govern respiratory pattern formation. PMID:26888109

  6. Interhemispheric Cerebral Blood Flow Balance during Recovery of Motor Hand Function after Ischemic Stroke—A Longitudinal MRI Study Using Arterial Spin Labeling Perfusion

    PubMed Central

    Missimer, John; Schroth, Gerhard; Hess, Christian W.; Sturzenegger, Matthias; Wang, Danny J. J.; Weder, Bruno; Federspiel, Andrea

    2014-01-01

    Background Unilateral ischemic stroke disrupts the well balanced interactions within bilateral cortical networks. Restitution of interhemispheric balance is thought to contribute to post-stroke recovery. Longitudinal measurements of cerebral blood flow (CBF) changes might act as surrogate marker for this process. Objective To quantify longitudinal CBF changes using arterial spin labeling MRI (ASL) and interhemispheric balance within the cortical sensorimotor network and to assess their relationship with motor hand function recovery. Methods Longitudinal CBF data were acquired in 23 patients at 3 and 9 months after cortical sensorimotor stroke and in 20 healthy controls using pulsed ASL. Recovery of grip force and manual dexterity was assessed with tasks requiring power and precision grips. Voxel-based analysis was performed to identify areas of significant CBF change. Region-of-interest analyses were used to quantify the interhemispheric balance across nodes of the cortical sensorimotor network. Results Dexterity was more affected, and recovered at a slower pace than grip force. In patients with successful recovery of dexterous hand function, CBF decreased over time in the contralesional supplementary motor area, paralimbic anterior cingulate cortex and superior precuneus, and interhemispheric balance returned to healthy control levels. In contrast, patients with poor recovery presented with sustained hypoperfusion in the sensorimotor cortices encompassing the ischemic tissue, and CBF remained lateralized to the contralesional hemisphere. Conclusions Sustained perfusion imbalance within the cortical sensorimotor network, as measured with task-unrelated ASL, is associated with poor recovery of dexterous hand function after stroke. CBF at rest might be used to monitor recovery and gain prognostic information. PMID:25191858

  7. A reversible bilateral renal artery stenosis in association with antiphospholipid syndrome.

    PubMed

    Remondino, G I; Mysler, E; Pissano, M N; Furattini, M C; Basta, M C; Presas, J L; Allievi, A

    2000-01-01

    We describe a 26-year-old white female with a history of Raynaud phenomenon, erythema nodosum, polyarthralgias, migraine, vertigo, seizures, transient ischemic attacks, one fetal loss, and false positive VDRL, who developed milk hypertension without overt lupus nephritis. She had positive antinuclear antibodies (ANA) and double-stranded deoxyribonucleic acid (dsDNA) antibodies. The lupus anticoagulant test (LAC) and cardiolipins antibodies (aCL) were positive. She was diagnosed as having a Systemic Lupus Erythematosus-like illness (SLE-like) with 'secondary' antiphospholipid syndrome (APS). Renal spiral computed tomography (CT) with intravenous (IV) contrast showed bilateral renal artery stenosis. Anticoagulation with acenocumarol was started. She became normotensive without antihypertensive drugs five months later. A follow-up renal spiral CT showed complete recanalization of both renal arteries, making thrombosis the more likely culprit pathology in the stenosis. After two years follow up the patient is normotensive. She remains on acenocumarol. PMID:10713649

  8. Salicylic acid analogues as chemical exchange saturation transfer MRI contrast agents for the assessment of brain perfusion territory and blood-brain barrier opening after intra-arterial infusion.

    PubMed

    Song, Xiaolei; Walczak, Piotr; He, Xiaowei; Yang, Xing; Pearl, Monica; Bulte, Jeff Wm; Pomper, Martin G; McMahon, Michael T; Janowski, Mirosław

    2016-07-01

    The blood-brain barrier (BBB) is a major obstacle for drug delivery to the brain. Predicted, focal opening of the BBB through intra-arterial infusion of hyperosmolar mannitol is feasible, but there is a need to facilitate imaging techniques (e.g. MRI) to guide interventional procedures and assess the outcomes. Here, we show that salicylic acid analogues (SAA) can depict the brain territory supplied by the catheter and detect the BBB opening, through chemical exchange saturation transfer (CEST) MRI. Hyperosmolar SAA solutions themselves are also capable of opening the BBB, and, when multiple SAA agents were co-injected, their locoregional perfusion could be differentiated. PMID:26980755

  9. 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.

  10. 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

  11. Posterior Reversible Encephalopathy Syndrome Mimicking a Left Middle Cerebral Artery Stroke

    PubMed Central

    Terranova, Santo; Kumar, Jai Dev; Libman, Richard B

    2012-01-01

    Certain Acute Clinical presentations are highly suggestive of stroke caused by specific mechanisms. One example of this would be the sudden onset of aphasia without hemiparesis often reflecting cerebral embolism, frequently from a cardiac source. Posterior reversible encephalopathy syndrome (PRES) describes a usually reversible neurologic syndrome with a variety of presenting symptoms from headache, altered mental status, seizures, vomiting, diminished spontaneity and speech, abnormalities of visual perception and visual loss. We report a patient presenting with elevated blood pressure, CT characteristics of PRES but a highly circumscribed neurologic syndrome (Wernicke's Aphasia without hemiparesis) suggestive of a cardioembolic stroke affecting the left MCA territory. That is, PRES mimicked a focal stroke syndrome. The importance of recognizing this possibility is that his deficits resolved with blood pressure control, while other treatments, such as intensifying his anticoagulation would have been inappropriate. In addition, allowing his blood pressure to remain elevated as is often done in the setting of an acute stroke might have perpetuated the underlying pathophysiology of PRES leading to a worse clinical outcome. For this reason PRES needs to be recognized quickly and treated appropriately. PMID:22371821

  12. Reversible pulmonary arterial hypertension associated with interferon-beta treatment for multiple sclerosis

    PubMed Central

    Gibbons, E; Promislow, S; Davies, RA; Chandy, G; Stewart, DJ; Contreras-Dominguez, V; Pugliese, C; Dunne, R; Mielniczuk, LM

    2015-01-01

    Interferon (IFN) therapy has an important role in the treatment of multiple sclerosis and chronic hepatitis C infection. A few case reports have described an association between IFN therapy and the development of irreversible pulmonary arterial hypertension (PAH), and it is currently listed as a possible drug-induced cause of PAH in the most recent classification of pulmonary hypertension. A causal link between IFN use and PAH remains to be elucidated; many reports of PAH resulting from IFN occur in individuals with some other risk factor for PAH. The authors present a case involving a patient with multiple sclerosis with no known risk factors for PAH, who developed severe PAH after exposure to IFN therapy. The patient experienced significant clinical and hemodynamic improvement, with normalization of her pulmonary pressures after the initiation of combination therapy for PAH. At 28 months after diagnosis, she remains asymptomatic with no hemodynamic evidence of PAH and has been off all PAH therapy for 10 months. PMID:26083539

  13. 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

  14. Reversing left bronchus obstruction by compression of a pulmonary artery stent.

    PubMed

    Brown, Stephen C; Proesmans, Marijke; Gewillig, Marc

    2016-07-01

    We report a case where endovascular stenting as part of the treatment of complex cardiovascular disease led to airway compression. Using a novel technique, this was successfully reversed. Simultaneous inflations of two balloons-one in the obstructed bronchus and one in the aorta combined with external compression of the chest-resulted in compression the stent. This report illustrates that by thinking "out of the box" and bearing in mind spatial relationships inside the chest, it is possible to diminish the anterior-posterior diameters of a stent. This intervention proved to be successful with relief of the left bronchial compression and improvement of chronic airway infection. © 2016 Wiley Periodicals, Inc. PMID:26762468

  15. Multi-modality imaging for the assessment of myocardial perfusion with emphasis on stress perfusion CT and MR imaging.

    PubMed

    Ko, Sung Min; Hwang, Hweung Kon; Kim, Sung Mok; Cho, Ihn Ho

    2015-06-01

    High-quality and non-invasive diagnostic tools for assessing myocardial ischemia are necessary for therapeutic decisions regarding coronary artery disease. Myocardial perfusion has been studied using myocardial contrast echo perfusion, single-photon emission computed tomography, positron emission tomography, cardiovascular magnetic resonance, and, more recently, computed tomography. The addition of coronary computed tomography angiography to myocardial perfusion imaging improves the specificity and overall diagnostic accuracy of detecting the hemodynamic significance of coronary artery stenosis. This study reviews the benefits, limitations, and imaging findings of various imaging modalities for assessing myocardial perfusion, with particular emphasis on stress perfusion computed tomography and cardiovascular magnetic resonance imaging. PMID:25809387

  16. MRI measurements of left ventricular systolic wall thickening compared to regional myocardial perfusion as determined by 201Tl SPECT in patients with coronary artery disease.

    PubMed

    Kleinhans, E; Altehoefer, C; Arnold, C; Buell, U; vom Dahl, J; Uebis, R

    1991-04-01

    Magnetic resonance imaging (MRI) of the left ventricle (LV) is an excellent method of measuring systolic wall thickening (SWT). The aim of the present study was (a) to describe a new approach for measurement of SWT and (b) to define the relationship between SWT and regional myocardial perfusion as determined by 201Tl SPECT. 79 patients -51 with and 28 without history of earlier myocardial infarction - underwent SPECT and, within the next two weeks. MRI. End-diastolic and end-systolic spin echo images were obtained by a reduced permutation technique. For MRI measurements, only long-axis sections through the LV in the equatorial plane were used. Slice orientation was selected according to the findings of SPECT, imaging the infarcted wall segment by single or double angulation. At 7 equidistant points around the LV wall SWT was measured and compared with the corresponding regional myocardial uptake values from SPECT in percent of maximal perfusion. Wall thickness of the anterior wall was normal. Because the majority of myocardial infarctions were posterior-inferior (55%), thickness of the posterior wall was markedly decreased. A close relationship of perfusion to SWT was found. Higher perfusion areas (greater than 50% of maximal TI uptake) corresponded with normal SWT (greater than 3.0 mm), a marked decrease of SWT (less than 1 mm) was found in areas with perfusion deficits (less than 40%). Thus, a 201TI uptake value at rest of 41-50% of the respective myocardial maximum acts as a threshold by discriminating normal from severely reduced SWT. PMID:2047242

  17. Glial fibrillary acidic protein (GFAP) immunoreactivity correlates with cortical perfusion parameters determined by bolus tracking arterial spin labelling (bt-ASL) magnetic resonance (MR) imaging in the Wistar Kyoto rat.

    PubMed

    Gormley, Shane; Rouine, Jennifer; McIntosh, Allison; Kerskens, Christian; Harkin, Andrew

    2016-06-01

    Alterations in astrocyte number and function have been implicated in the pathophysiology of a number of psychiatric disorders. The development of magnetic resonance imaging (MRI) as a tool in the animal laboratory has enabled an investigation of the relationship between pathological and neuroimaging markers in animal models. However the physiological processes which underlie these markers and their role in mediating behavioural deficits is still poorly understood. Rodent models have provided us with important insights into physiological and cellular mechanisms which may mediate anxiety and depression-related behaviours. The Wistar-Kyoto (WKY) rat is a strain which endogenously expresses highly anxious and depressive-like behaviours and has previously been reported to exhibit alterations in immunoreactivity for the astrocytic marker glial fibrillary acidic protein (GFAP) in brain sub-regions relative to more stress resilient out-bred strains. Here we report that the depressive and anxiety-like behaviours exhibited by the WKY rat strain are associated with alterations in brain morphology including a decrease in hippocampal volume, coupled with reduced resting state frontal cortical perfusion as assessed by MR bolus tracking arterial spin labelling (bt-ASL) relative to the out-bred Wistar strain. Pre-limbic cortical GFAP immunoreactivity and astrocyte cell number were positively correlated with cortical blood perfusion in the WKY strain. These experiments provide a link between pathological and neuroimaging markers of aberrant astrocytic function and add validity to the WKY rat as a model for co-morbid anxiety and depression. PMID:27068181

  18. Sublingual microvascular perfusion is altered during normobaric and hyperbaric hyperoxia.

    PubMed

    Milstein, Dan M J; Helmers, Renée; Hackmann, Sanne; Belterman, Charly N W; van Hulst, Robert A; de Lange, Jan

    2016-05-01

    Hyperoxia and hyperbaric oxygen therapy can restore oxygen tensions in tissues distressed by ischemic injury and poor vascularization and is believed to also yield angiogenesis and regulate tissue perfusion. The aim of this study was to develop a model in which hyperoxia-driven microvascular changes could be quantified and to test the hypothesis that microcirculatory responses to both normobaric (NB) and hyperbaric (HB) hyperoxic maneuvers are reversible. Sublingual mucosa microcirculation vessel density, proportion of perfused vessels, vessel diameters, microvascular flow index, macrohemodynamic, and blood gas parameters were examined in male rabbits breathing sequential O2/air mixtures of 21%, 55%, 100%, and return to 21% during NB (1.0bar) and HB (2.5bar) conditions. The results indicate that NB hyperoxia (55% and 100%) produced significant decreases in microvascular density and vascular diameters (p<0.01 and p<0.05, respectively) accompanied by significant increases in systolic and mean arterial blood pressure (p<0.05, respectively) with no changes in blood flow indices when compared to NB normoxia. HB normoxia/hyperoxia resulted in significant decreases in microvascular density (p<0.05), a transient rise in systolic blood pressure at 55% (p<0.01), and no changes in blood vessel diameter and blood flow indices when compared to NB hyperoxia. All microcirculation parameters reverted back to normal values upon return to NB normoxia. We conclude that NB/HB hyperoxia-driven changes elicit reversible physiological control of sublingual mucosa blood perfusion in the presence of steady cardiovascular function and that the absence of microvascular vasoconstriction during HB conditions suggests a beneficial mechanism associated with maintaining peak tissue perfusion states. PMID:26851620

  19. Blood pressure reverse dipping may associate with stable coronary artery disease in patients with essential hypertension: a cross-sectional study

    PubMed Central

    Yan, Bin; Sun, Lu; Gao, Ya; Guo, Qi; Guo, Litao; Wang, Xue; Wang, Gang

    2016-01-01

    The dipping variations of circadian blood pressure (BP) correlate closely with target-organ damages and cardiovascular events. The aim of this study was to investigate the relationship between BP reverse dipping and the prevalence of stable coronary artery disease (sCAD) in hypertensive patients. Clinical data and the results of 24-hour ambulatory BP monitoring (ABPM) were obtained from 718 hypertensive patients (390 males, mean age 59.6 ± 13.8 years) in a single centre in Northern China. Reverse dipping pattern was defined as nocturnal systolic BP (SBP) was higher than daytime SBP. A logistic regression model was applied to explore the independent risk factors of sCAD. The patients with BP reverse dipping accounted for 31.5% in sCAD group and 19.5% in control group (P < 0.05). In multivariate analysis, BP reverse dipping remained significantly associated with the prevalence of sCAD (Odds ratio [OR], 1.772; p = 0.027). Furthermore, the circadian decline rate of SBP was independently associated with sCAD (OR, 0.975; p = 0.043). The hypertensive patients with reverse BP dipping were found to be more frequently suffering from sCAD. BP reverse dipping examined with 24-hour ABPM may indicate sCAD. PMID:27139821

  20. Blood pressure reverse dipping may associate with stable coronary artery disease in patients with essential hypertension: a cross-sectional study.

    PubMed

    Yan, Bin; Sun, Lu; Gao, Ya; Guo, Qi; Guo, Litao; Wang, Xue; Wang, Gang

    2016-01-01

    The dipping variations of circadian blood pressure (BP) correlate closely with target-organ damages and cardiovascular events. The aim of this study was to investigate the relationship between BP reverse dipping and the prevalence of stable coronary artery disease (sCAD) in hypertensive patients. Clinical data and the results of 24-hour ambulatory BP monitoring (ABPM) were obtained from 718 hypertensive patients (390 males, mean age 59.6 ± 13.8 years) in a single centre in Northern China. Reverse dipping pattern was defined as nocturnal systolic BP (SBP) was higher than daytime SBP. A logistic regression model was applied to explore the independent risk factors of sCAD. The patients with BP reverse dipping accounted for 31.5% in sCAD group and 19.5% in control group (P < 0.05). In multivariate analysis, BP reverse dipping remained significantly associated with the prevalence of sCAD (Odds ratio [OR], 1.772; p = 0.027). Furthermore, the circadian decline rate of SBP was independently associated with sCAD (OR, 0.975; p = 0.043). The hypertensive patients with reverse BP dipping were found to be more frequently suffering from sCAD. BP reverse dipping examined with 24-hour ABPM may indicate sCAD. PMID:27139821

  1. 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

    2015-01-01

    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). PMID:25435383

  2. 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

  3. Autologous Mesenchymal Stem Cells Produce Concordant Improvements in Regional Function, Tissue Perfusion and Fibrotic Burden when Administered to Patients Undergoing Coronary Artery Bypass Grafting – The PROMETHEUS Trial

    PubMed Central

    Karantalis, Vasileios; DiFede, Darcy L.; Gerstenblith, Gary; Pham, Si; Symes, James; Zambrano, Juan Pablo; Fishman, Joel; Pattany, Pradip; McNiece, Ian; Conte, John; Schulman, Steven; Wu, Katherine; Shah, Ashish; Breton, Elayne; Davis-Sproul, Janice; Schwarz, Richard; Feigenbaum, Gary; Mushtaq, Muzammil; Suncion, Viky Y.; Lardo, Albert C.; Borrello, Ivan; Mendizabal, Adam; Karas, Tomer Z.; Byrnes, John; Lowery, Maureen; Heldman, Alan W.; Hare, Joshua M.

    2014-01-01

    Rationale While accumulating data support the efficacy of intramyocardial cell-based therapy to improve LV function in patients with chronic ischemic cardiomyopathy undergoing CABG, the underlying mechanism and impact of cell injection site remain controversial.Mesenchymal stem cells (MSCs) improve LV structure and function through several effects including: reducing fibrosis, neoangiogenesis and neomyogenesis. Objective To test the hypothesis that the impact on cardiac structure and function following intramyocardial injections of autologous MSCs results from a concordance of pro-recovery phenotypic effects. Methods and Results Six patients were injected with autologous MSCs into akinetic/hypokinetic myocardial territories not receiving bypass graft for clinical reasons. MRI was used to measure scar, perfusion, wall thickness and contractility at baseline, 3, 6 and 18 months and to compare structural and functional recovery in regions that received MSC injections alone, revascularization alone, or neither. A composite score of MRI variables was used to assess concordance of antifibrotic effects, perfusion, and contraction at different regions. After 18 months, subjects receiving MSCs exhibited increased LVEF (+9.4±1.7%, p=0.0002) and decreased scar mass (-47.5±8.1%; p<0.0001) compared to baseline. MSC-injected segments had concordant reduction in scar size, perfusion and contractile improvement (concordant score: 2.93±0.07), whereas revascularized (0.5±0.21) and non-treated segments (-0.07±0.34) demonstrated non-concordant changes (p<0.0001 vs. injected segments). Conclusions Intramyocardial injection of autologous MSCs into akinetic yet non-revascularized segments produces comprehensive regional functional restitution, which in turn drives improvement in global LV function. These findings, although inconclusive due to lack of placebo group, have important therapeutic and mechanistic hypothesis-generating implications. PMID:24565698

  4. Effects of Steroid Hormones on Sex Differences in Cerebral Perfusion

    PubMed Central

    Ghisleni, Carmen; Bollmann, Steffen; Biason-Lauber, Anna; Poil, Simon-Shlomo; Brandeis, Daniel; Martin, Ernst; Michels, Lars; Hersberger, Martin; Suckling, John

    2015-01-01

    Sex differences in the brain appear to play an important role in the prevalence and progression of various neuropsychiatric disorders, but to date little is known about the cerebral mechanisms underlying these differences. One widely reported finding is that women demonstrate higher cerebral perfusion than men, but the underlying cause of this difference in perfusion is not known. This study investigated the putative role of steroid hormones such as oestradiol, testosterone, and dehydroepiandrosterone sulphate (DHEAS) as underlying factors influencing cerebral perfusion. We acquired arterial spin labelling perfusion images of 36 healthy adult subjects (16 men, 20 women). Analyses on average whole brain perfusion levels included a multiple regression analysis to test for the relative impact of each hormone on the global perfusion. Additionally, voxel-based analyses were performed to investigate the sex difference in regional perfusion as well as the correlations between local perfusion and serum oestradiol, testosterone, and DHEAS concentrations. Our results replicated the known sex difference in perfusion, with women showing significantly higher global and regional perfusion. For the global perfusion, DHEAS was the only significant predictor amongst the steroid hormones, showing a strong negative correlation with cerebral perfusion. The voxel-based analyses revealed modest sex-dependent correlations between local perfusion and testosterone, in addition to a strong modulatory effect of DHEAS in cortical, subcortical, and cerebellar regions. We conclude that DHEAS in particular may play an important role as an underlying factor driving the difference in cerebral perfusion between men and women. PMID:26356576

  5. Hypothermic machine perfusion of the liver and the critical balance between perfusion pressures and endothelial injury.

    PubMed

    't Hart, N A; van der Plaats, A; Leuvenink, H G D; van Goor, H; Wiersema-Buist, J; Verkerke, G J; Rakhorst, G; Ploeg, R J

    2005-01-01

    Hypothermic machine perfusion (HMP) provides better protection against cold ischemic injury than cold storage in marginal donor kidneys. Also, in liver transplantation a switch from static cold storage to HMP could be beneficial as it would allow longer preservation times and the use of marginal donors. A critical question concerning application of HMP in liver preservation is the crucial balance between perfusion pressure and occurrence of endothelial injury. Rat livers were cold-perfused for 24 hours to study perfusion pressures for both hepatic artery and portal vein. Cold storage served as control and was compared to HMP-preserved livers using a mean arterial perfusion pressure of 25 mm Hg and a portal perfusion pressure of 4 mm Hg (25% of normothermic liver circulation) and to HMP at 50 mm Hg and 8 mm Hg perfusion, respectively (50% of normothermic liver circulation). UW solution was enriched with 14.9 micromol/L propidium iodide (PI) to stain for dead cells and with an additional 13.5 micromol/L acridine orange to stain for viable hepatocytes. A low PI-positive cell count was found using HMP at 25% of normal circulation compared to cold storage. The PI count was high for the HMP group perfused at just 50% of normal circulation compared to HMP at 25% and compared to cold storage. In summary, for liver HMP, perfusion at 25% showed complete perfusion with minimal cellular injury. HMP using perfusion pressures of 25 mm Hg for the hepatic artery and 4 mm Hg for the portal vein is feasible without induction of endothelial injury. PMID:15808634

  6. [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

  7. Use of technetium-99m isonitrile (RP-30A) in assessing left ventricular perfusion and function at rest and during exercise in coronary artery disease, and comparison with coronary arteriography and exercise thallium-201 SPECT imaging

    SciTech Connect

    Iskandrian, A.S.; Heo, J.; Kong, B.; Lyons, E.; Marsch, S. )

    1989-08-01

    This study compared the results of stress and rest single-photon emission computed tomography imaging of myocardial perfusion using technetium-99m isonitrile (RP-30A) with the results of stress and redistribution tomographic thallium imaging and the results of coronary arteriography in 39 patients, 11 without and 28 with coronary artery disease (CAD). Each patient underwent 2 exercise studies at identical workload, heart rate and double product. In a subset of 13 patients, concomitant evaluation of left ventricular (LV) function using first-pass radionuclide angiography with a multi-crystal camera also was performed with bolus injections of isonitrile. Isonitrile had similar sensitivity (82 vs 82%, difference not significant), a slightly--but not significantly--higher specificity (100 vs 82%) and similar predictive accuracy (87 vs 82%) to thallium-201. The tracer uptake was assessed in 20 segments/study. There was concordance between the isonitrile and thallium-201 images in 723 of the 780 segments (93%) (kappa = 0.83 +/- 0.02). In general, the isonitrile images were considered of better quality than the thallium-201 images. All 10 patients with CAD who underwent concomitant first-pass radionuclide angiography had either perfusion abnormalities or an abnormal ejection fraction response to exercise. Thus, technetium-99m isonitrile provides a reliable method of assessment of CAD with a sensitivity, specificity and predictive accuracy comparable to that of exercise thallium-201 imaging. Additional advantages include better image quality and the ability to obtain concomitant assessment of LV function with the use of first-pass radionuclide angiography.

  8. Cerebral metabolism and perfusion in MR-negative individuals with refractory focal epilepsy assessed by simultaneous acquisition of (18)F-FDG PET and arterial spin labeling.

    PubMed

    Boscolo Galazzo, Ilaria; Mattoli, Maria Vittoria; Pizzini, Francesca Benedetta; De Vita, Enrico; Barnes, Anna; Duncan, John S; Jäger, Hans Rolf; Golay, Xavier; Bomanji, Jamshed B; Koepp, Matthias; Groves, Ashley M; Fraioli, Francesco

    2016-01-01

    The major challenge in pre-surgical epileptic patient evaluation is the correct identification of the seizure onset area, especially in MR-negative patients. In this study, we aimed to: (1) assess the concordance between perfusion, from ASL, and metabolism, from (18)F-FDG, acquired simultaneously on PET/MR; (2) verify the utility of a statistical approach as supportive diagnostic tool for clinical readers. Secondarily, we compared (18)F-FDG PET data from the hybrid PET/MR system with those acquired with PET/CT, with the purpose of validate the reliability of (18)F-FDG PET/MR data. Twenty patients with refractory focal epilepsy, negative MR and a defined electro-clinical diagnosis underwent PET/MR, immediately followed by PET/CT. Standardized uptake value ratio (SUVr) and cerebral blood flow (CBF) maps were calculated for PET/CT-PET/MR and ASL, respectively. For all techniques, z-score of the asymmetry index (zAI) was applied for depicting significant Right/Left differences. SUVr and CBF images were firstly visually assessed by two neuroimaging readers, who then re-assessed them considering zAI for reaching a final diagnosis. High agreement between (18)F-FDG PET/MR and ASL was found, showing hypometabolism and hypoperfusion in the same hemisphere in 18/20 patients, while the remaining were normal. They were completely concordant in 14/18, concordant in at least one lobe in the remaining. zAI maps improved readers' confidence in 12/20 and 15/20 patients for (18)F-FDG PET/MR and ASL, respectively. (18)F-FDG PET/CT-PET/MR showed high agreement, especially when zAI was considered. The simultaneous metabolism-perfusion acquisition provides excellent concordance on focus lateralisation and good concordance on localisation, determining useful complementary information. PMID:27222796

  9. [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. PMID:25700252

  10. Site of pulmonary vasodilation by inhaled nitric oxide in the perfused lung

    SciTech Connect

    Rimar, S.; Gillis, C.N.

    1995-05-01

    Site of pulmonary vasodilation by inhaled nitric oxide in the perfused lung. To determine the site of inhaled nitric oxide (NO)-induced pulmonary vasodilation, a double vascular occlusion technique was used with rabbit lungs ventilated and perfused at 20 ml/min with Krebs solution containing 3% dextran and 30 {mu}M indomethacin. Inhaled NO (120 ppm for 3% min) reduced pulmonary vasoconstriction produced by U-46619 infusion (0.5 -1.2 nmol/min), significantly decreasing total resistance (RT) [1,080 {plus_minus} 51 (SE) vs. 1,545 {plus_minus} 109 mmHg-min/l; P < 0.01]. Acetylcholine infusion (ACh; 2-5 nmol/min) and nitroglycerin (NTG; 0.35 {mu}mol) likewise decreased RT. Arterial resistance (Ra) was also significantly less with inhaled NO, ACh, and NTG compared with U-46619 alone. Venous resistance (Rv), however, was unchanged. When the direction of perfusion was reversed in the lung, inhaled NO, ACh, and NTG significantly decreased RT compared with U-46619 alone, and Rv was also reduced by all three agents. After electrolysis-induced acute lung injury, inhaled NO significantly reduced both RT and Ra compared with U-46619 alone, whereas Rv was unaffected. Our results demonstrate that inhaled NO gas affects primarily the arterial (precapillary) component of the pulmonary circulation but, under conditions of extreme venous constriction, may dilate the postcapillary component as well. 25 refs., 4 figs.

  11. 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

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

    SciTech Connect

    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).

  13. Surgical treatment of acute myocardial ischaemia related to coronary angioplasty with special reference to use of perfusion balloon catheter and long-term outcome.

    PubMed

    Heikkinen, L; Virtanen, K; Heikkila, J; Verkkala, K; Salo, J; Jarvinen, A

    1997-04-01

    Twenty of 569 consecutive patients (3.5%) undergoing percutaneous transluminal coronary angioplasty required emergency coronary artery bypass grafting for acute closure of the dilated vessel. In seven patients an intracoronary autoperfusion balloon catheter was inserted to ensure antegrade blood flow across the injured zone of the coronary artery. The time needed for completion of the bypass grafts ranged from 100 to 399 minutes (mean 180 minutes). An average of 1.9 coronary artery bypasses was inserted. In total, 11 of the 20 patients (55%) developed new Q waves and had elevated CK-MB levels. However, the myocardial infarction rate was only 14% in those with a perfusion balloon catheter as against 77% in those without one. The insertion of a ball-out catheter permitted greater utilization of the internal mammary artery as a bypass graft. Angiographic follow-up was conducted after a mean of 28 months (19 patients). The patency rate of the bypass grafts placed in the emergency setting was relatively good (91%). Thallium tomography revealed a scar of variable size in all 17 patients studied and a reversible exercise perfusion defect requiring coronary reangioplasty in three patients. In conclusion, the insertion of a perfusion balloon catheter after abrupt coronary occlusion during coronary angioplasty solved the problems of acute myocardial ischemia and markedly lowered the definite myocardial infarction rate. This technique ensures favourable haemodynamic conditions for emergency myocardial revascularization. PMID:9201117

  14. Partial Aortic Occlusion and Cerebral Venous Steal: Venous Effects of Arterial Manipulation in Acute Stroke

    PubMed Central

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

    2011-01-01

    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, manifest 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. PMID:21441149

  15. 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

  16. 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

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

    PubMed

    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

  18. 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.

  19. Prediction of multivessel coronary artery disease and prognosis early after acute myocardial infarction by exercise electrocardiography and thallium-201 myocardial perfusion scanning

    SciTech Connect

    Abraham, R.D.; Freedman, S.B.; Dunn, R.F.; Newman, H.; Roubin, G.S.; Harris, P.J.; Kelly, D.T.

    1986-09-01

    Exercise electrocardiography and thallium scanning were performed a mean of 24 days after uncomplicated acute myocardial infarction in 103 patients, aged 36 to 60 years, who also underwent coronary angiography. The purpose of the study was to determine the ability of the noninvasive tests to predict multivessel coronary artery disease (CAD) and prognosis. Patients were followed up to document medical complications (incidence 12%: 3 deaths, 1 resuscitated cardiac arrest, 4 recurrent infarctions, 4 admissions with unstable angina) and combined events (medical events or bypass surgery, incidence 23%). The sensitivity, specificity and predictive accuracy for predicting multivessel CAD were 64%, 77% and 64% for a positive exercise electrocardiographic (ECG) response, 64%, 88% and 80% for a remote thallium defect, and 42%, 96% and 88% for a combination of the 2 tests. With 2 tests yielding negative findings the probability of multivessel CAD was 13%. No variable (positive exercise ECG response, remote thallium defect and presence of multivessel CAD) predicted medical events, although there were nonsignificant trends to more events in patients with any of those findings. The relative risk of combined events was 2.5 (p less than 0.05) for a positive exercise ECG response; 1.8 (NS) for a remote thallium defect; 2.6 (p less than 0.05) for multivessel CAD; and 3.1 (p less than 0.025) for both positive ECG response and remote defect. A combination of exercise electrocardiography and thallium scanning early after acute myocardial infarction helps to identify subsets of patients with high and low probabilities of multivessel CAD and combined medical or surgical events.

  20. Reliability of Three-Dimensional Pseudo-Continuous Arterial Spin Labeling MR Imaging for Measuring Visual Cortex Perfusion on Two 3T Scanners

    PubMed Central

    Huang, Diandian; Wu, Bing; Shi, Kaining; Ma, Lin; Cai, Youquan; Lou, Xin

    2013-01-01

    Cerebral blood flow (CBF) in the human primary visual cortex is correlated with the loss of visual function in neuro-ophthalmological diseases. Advanced three-dimensional pseudo-continuous arterial spin labeling (3D pCASL), as a non-invasive method to access the CBF, can be a novel measurement to detect the visual cortex. The objective of the study was to assess the intra- and inter-scanner reliability of 3D pCASL of the visual cortex in healthy adults and suggest the selection of different post-labeling delay times (PLDs). For this reason, 3D pCASL was conducted in two 3.0T MR three times with twelve healthy volunteers at an interval of 10–15 days. The 1st and 3rd tests were performed on scanner-1, and the 2nd test was performed on scanner-2. The value of the CBF was abstracted from the visual cortex with two PLDs. The intra- and inter-scanner reliability and reproducibility were evaluated with the intraclass correlation coefficient (ICC) and Bland-Altman plots. By estimating the mean value of the CBF in the visual cortex, the intra-scanner results demonstrated the higher reliability (ICC for PLD = 1.5 second presented at 0.743 compared with 0.829 for PLD = 2.5 seconds), and the Bland-Altman plots showed the reproducibility at a longer PLD. We conclude that the calibrated 3D pCASL approach provides a highly reproducible measurement of the CBF of the visual cortex that can serve as a useful quantitative probe for research conducted at multiple centers and for the long-term observation of the clinical effects of neuro-opthalmological diseases. PMID:24278137

  1. 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

    2015-01-01

    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. PMID:26327608

  2. Developing a Benchmarking Process in Perfusion: A Report of the Perfusion Downunder Collaboration

    PubMed Central

    Baker, Robert A.; Newland, Richard F.; Fenton, Carmel; McDonald, Michael; Willcox, Timothy W.; Merry, Alan F.

    2012-01-01

    Abstract: Improving and understanding clinical practice is an appropriate goal for the perfusion community. The Perfusion Downunder Collaboration has established a multi-center perfusion focused database aimed at achieving these goals through the development of quantitative quality indicators for clinical improvement through benchmarking. Data were collected using the Perfusion Downunder Collaboration database from procedures performed in eight Australian and New Zealand cardiac centers between March 2007 and February 2011. At the Perfusion Downunder Meeting in 2010, it was agreed by consensus, to report quality indicators (QI) for glucose level, arterial outlet temperature, and pCO2 management during cardiopulmonary bypass. The values chosen for each QI were: blood glucose ≥4 mmol/L and ≤10 mmol/L; arterial outlet temperature ≤37°C; and arterial blood gas pCO2 ≥ 35 and ≤45 mmHg. The QI data were used to derive benchmarks using the Achievable Benchmark of Care (ABC™) methodology to identify the incidence of QIs at the best performing centers. Five thousand four hundred and sixty-five procedures were evaluated to derive QI and benchmark data. The incidence of the blood glucose QI ranged from 37–96% of procedures, with a benchmark value of 90%. The arterial outlet temperature QI occurred in 16–98% of procedures with the benchmark of 94%; while the arterial pCO2 QI occurred in 21–91%, with the benchmark value of 80%. We have derived QIs and benchmark calculations for the management of several key aspects of cardiopulmonary bypass to provide a platform for improving the quality of perfusion practice. PMID:22730861

  3. 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.

  4. Pulmonary ventilation/perfusion scan

    MedlinePlus

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a health ...

  5. Correlation of myocardial perfusion SPECT with invasive and computed tomography coronary angiogram

    PubMed Central

    Shelley, S.; Indirani, M.; Sathyamurthy, I.; Subramanian, K.; Priti, N.; Harshad, K.; Padma, D.

    2012-01-01

    Background The consequences of atherosclerosis can be detected by multislice computed tomography (MSCT), invasive coronary angiogram (CAG) and the resultant myocardial ischaemia by myocardial perfusion single photon emission computed tomography (MPS). In this study an attempt is made to compare MSCT with MPS and also to compare the MSCT findings with that of invasive CAG in patients suspected to have coronary artery disease (CAD). Materials and methods A total of 99 patients suspected to have CAD underwent both MSCT and MPS with 99mTc sestamibi. The MSCT studies were classified as having no CAD, significant CAD (>50% diameter stenosis), and insignificant CAD (<50% diameter stenosis). Myocardial perfusion single photon emission computed tomography was reported as normal and reversible ischaemia. In a subgroup of 33 patient invasive CAG was done. Results In 99 patients, 396 coronaries were evaluated with MSCT and MPS. Coronary artery calcium scoring (CACS) in these patient ranged from 0 to 2200. No CAD was noted in 128 (32%) coronaries but MPS was found abnormal in 9 (7%) coronaries. Insignificant CAD was noted in 169 (43%) coronaries amongst which reversible ischaemia was noted in 23 (14%). Significant CAD was noted in 99 (25%) coronaries of which only 54 (55%) were MPS positive for reversible ischaemia. The MSCT has a negative predictive value (NPV) of 97%. When MSCT was normal, MPS was almost normal, but the reverse was not true. That is when MPS was normal MSCT was not always normal but showed lesion of insignificant obstruction. In the subset of 33 patients, who underwent invasive angiogram, 132 coronaries were evaluated. Coronary angiogram showed 48 coronaries (36%) to have significant CAD (>50% diameter stenosis). Multislice computed tomography correlated well in 46 (84%) with P value of <0.001 (χ2-test) but for 9 (16%) showing overestimation due to increased CACS (>800). Myocardial perfusion single photon emission computed tomography was normal in 15 (27

  6. Ex vivo lung graft perfusion.

    PubMed

    Briot, Raphaël; Gennai, Stéphane; Maignan, Maxime; Souilamas, Redha; Pison, Christophe

    2016-04-01

    This review proposes an update of the state of the art and the ongoing clinical trials of ex vivo lung perfusion for lung transplantation in patients. Ex vivo lung perfusion techniques (EVLP) can be used to evaluate a lung graft outside of the body. The goal of EVLP is to study the functional status of lung grafts that were first rejected for transplantation because they did not match all criteria for a conventional transplantation. After an EVLP evaluation, some of these lungs may be requalified for a possible transplantation in patients. This article proposes an overview of the developments of EVLP techniques. During EVLP, the perfusion and ventilation of the isolated lung preparation are very progressive in order to avoid oedema due to ischaemia-reperfusion injuries. Lung evaluation is mainly based on gasometric (PaO2/FiO2) and rheological criteria (low pulmonary arterial resistance). Several series of patients transplanted with EVLP evaluated lungs have been recently published with promising results. EVLP preparations also allow a better understanding of the physiopathology and treatments of ischaemia-reperfusion injuries. Organ procurements from "non-heart-beating" donors will probably require a wider application of these ex vivo techniques. The development of semi-automated systems might facilitate the clinical use of EVLP techniques. PMID:26746565

  7. The prognostic value of non-perfusion variables obtained during vasodilator stress myocardial perfusion imaging.

    PubMed

    Bajaj, Navkaranbir S; Singh, Siddharth; Farag, Ayman; El-Hajj, Stephanie; Heo, Jack; Iskandrian, Ami E; Hage, Fadi G

    2016-06-01

    Myocardial perfusion imaging (MPI) is an established diagnostic test that provides useful prognostic data in patients with known or suspected coronary artery disease. In more than half of the patients referred for stress testing, vasodilator stress is used in lieu of exercise. Unlike exercise, vasodilator stress does not provide information on exercise and functional capacity, heart rate recovery, and chronotropy, and ECG changes are less frequent. These non-perfusion data provide important prognostic and patient management information. Further, event rates in patients undergoing vasodilator MPI are higher than in those undergoing exercise MPI and even in those with normal images probably due to higher pretest risk. However, there are a number of non-perfusion variables that are obtained during vasodilator stress testing, which have prognostic relevance but their use has not been well emphasized. The purpose of this review is to summarize the prognostic values of these non-perfusion data obtained during vasodilator MPI. PMID:26940574

  8. 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.

  9. Endothelial Dysfunction is Associated with Occult Coronary Artery Disease Detected by Positron Emission Tomography

    PubMed Central

    Kulshreshtha, Ambar; Zheng, Yan; Quyyumi, Arshed A.; Veledar, Emir; Votaw, John; Uphoff, Irina; Bremner, Douglas J.; Goldberg, Jack; Vaccarino, Viola

    2014-01-01

    Objective Silent myocardial ischemia is common in asymptomatic subjects without a prior history of coronary artery disease (CAD) and is associated with increased morbidity and mortality. Our objective was to determine whether endothelial dysfunction is associated with silent myocardial ischemia and whether the association is independent of genetic and familial factors. Material and methods We examined 416 male monozygotic and dizygotic twins aged 47 to 63 years, free of symptomatic CAD. Subclinical ischemia was diagnosed by [13N] ammonia positron emission tomography at rest and after adenosine stress. Endothelial function was measured by flow-mediated dilation (FMD) of the brachial artery. Generalized estimating equations were used for analysis. Results Fixed perfusion defects were found in 24 (6%) twins and reversible perfusion defects in 90 (22%) twins, indicating subclinical ischemia. There was an inverse correlation between FMD and the reversible perfusion defect score (r = - 0.14, p=0.01) but not the fixed defect score (r= -0.017, p=0.73). From the lowest to the highest quartile of FMD, the prevalence of reversible defects decreased 28% to 14%, p=0.008. In multivariable analysis, reversible defects were significantly associated with each quartile of decreasing FMD (OR =1.3; 95% 1.1, 2.5). In 54 twin pairs discordant for endothelial dysfunction (FMD ≤ 7% dilation from baseline), twins with endothelial dysfunction had 9% higher likelihood of having perfusion defects than their co-twins without endothelial dysfunction (p=0.041). Conclusions Endothelial dysfunction is independently associated with silent ischemia and this association is not confounded by genetic or other shared familial factors. PMID:25414815

  10. Do preoperative haemodynamic data and reactivity test predict the postoperative reversibility of pulmonary arterial hypertension in patients with large ventricular septal defect and borderline operability?

    PubMed Central

    Sridhar, Anuradha; Subramanyan, Raghavan; Lakshmi, Nithya; Farzana, Farida; Tripathi, Ravi Ranjan; Premsekar, Rajasekaran; Chidambaram Pillai, Shanthi; Krishna Manohar, Soman Rema; Agarwal, Ravi; Cherian, Kotturathu Mammen

    2013-01-01

    Background Decisions to operate on patients with shunt lesions presenting late with severe pulmonary arterial hypertension (PAH) and borderline operability are often not based on precise cut off values of haemodynamic data owing to paucity of studies. Objective To assess the reliability of the preoperative haemodynamic data and reactivity test in predicting the postoperative reversibility of PAH in patients with isolated large ventricular septal defects (VSDs) and borderline operability. Patients and method Between 2004 and 2010, 30 patients underwent VSD closure surgically; no early deaths occurred. Twenty-six patients were followed up regularly (mean 39.6±16 months) and one late postoperative death occurred. Fourteen patients who had been followed up for at least 1 year postoperatively underwent cardiac catheterisation. Results There were 3 responders (asymptomatic patients with pulmonary vascular resistance (PVR) index <3 WU.m2) and 12 non-responders. The following were lower among responders: mean age at surgery (3.2±0.42 vs 11.55±3.29 years, p=0.227), mean baseline PVR index (3.69±0.8 vs 10.57±9.1, p=0.204), average resistance ratio (RR=0.25±0.01 vs 0.59±0.25, p=0.049) and ratio of pulmonary and systemic mean pressures (PAm:SAm ratio) (0.70±0.009 vs 0.87±0.118, p=0.003). Conclusions Preoperative ‘base line’ PAm:SAm and RR appear to be better predictors of postoperative outcome than other baseline parameters. Preoperative reactivity test had no significant role in predicting postoperative reversibility of PAH at mid-term. PMID:27326120

  11. CT Perfusion ASPECTS in the Evaluation of Acute Ischemic Stroke: Thrombolytic Therapy Perspective

    PubMed Central

    Sillanpaa, Niko; Saarinen, Jukka T.; Rusanen, Harri; Hakomaki, Jari; Lahteela, Arto; Numminen, Heikki; Elovaara, Irina; Dastidar, Prasun; Soimakallio, Seppo

    2011-01-01

    Background and Purpose Advances in the management of acute ischemic stroke and medical imaging are creating pressure to replace the rigid one-third middle cerebral artery (MCA) and non-contrast-enhanced CT (NCCT) Alberta Stroke Program Early CT Score (ASPECTS) thresholds used for the selection of patients eligible for intravenous thrombolytic therapy. The identification of potentially salvageable ischemic brain tissue lies at the core of this issue. In this study, the role of CT perfusion ASPECTS in the detection of reversible ischemia was analyzed. Materials and Methods We retrospectively reviewed the clinical and imaging data of 92 consecutive patients who received intravenous thrombolytic therapy for acute (duration <3 h) ischemic stroke. Most of the patients underwent admission multimodal CT, and all patients had follow-up NCCT at 24 h. ASPECTS was assigned to all modalities and correlated with clinical and imaging parameters. Receiver-operating characteristic curve analysis was performed to determine optimal thresholds for different parameters to predict clinical outcome. Results A perfusion defect could be detected in 50% of the patients. ASPECTS correlated inversely with the clinical outcome in the following order: follow-up NCCT > cerebral blood volume (CBV) > mean transit time (MTT) > admission NCCT. The follow-up NCCT and the CBV displayed a statistically significant difference from the admission NCCT, while the MTT did not reach statistical significance. The threshold that best differentiated between good and bad clinical outcome on admission was CBV ASPECTS ≥7. In patients with CT perfusion ASPECTS mismatch, MTT and CBV ASPECTS essentially provided the lower and upper limits for the follow-up NCCT ASPECTS, thus defining the spectrum of possible outcomes. Furthermore, CT perfusion ASPECTS mismatch strongly correlated (r = 0.83) with the mismatch between the tissue at risk and the final infarct, i.e. the amount of salvaged tissue. This finding suggests

  12. Gradient-enhanced FAWSETS perfusion measurements

    NASA Astrophysics Data System (ADS)

    Marro, Kenneth I.; Lee, Donghoon; Hyyti, Outi M.

    2005-08-01

    This work describes the use of custom-built gradients to enhance skeletal muscle perfusion measurements acquired with a previously described arterial spin labeling technique known as FAWSETS (flow-driven arterial water stimulation with elimination of tissue signal). Custom-built gradients provide active control of the static magnetic field gradient on which FAWSETS relies for labeling. This allows selective, 180° modulations of the phase of the perfusion component of the signal. Phase cycling can then be implemented to eliminate all extraneous components leaving a signal that exclusively reflects capillary-level perfusion. Gradient-enhancement substantially reduces acquisition time and eliminates the need to acquire an ischemic signal to quantify perfusion. This removes critical obstacles to application of FAWSETS in organs other than skeletal muscle and makes the measurements more desirable for clinical environments. The basic physical principles of gradient-enhancement are demonstrated in flow phantom experiments and in vivo utility is demonstrated in rat hind limb during stimulated exercise.

  13. NOTE: Polyhydramnios and arterio-arterial placental anastomoses may beneficially affect monochorionic twin pregnancies

    NASA Astrophysics Data System (ADS)

    van Gemert, Martin J. C.; Kranenburg-Lakeman, Phillis; Milovanovic, Zeljko; Vergroesen, Isabelle; Boer, Kees

    2001-03-01

    Our objective was to appraise whether an increased amniotic fluid pressure by polyhydramnios can beneficially affect monochorionic twins that are haemodynamically connected by arterio-venous plus arterio-arterial placental anastomoses. We assessed the effects of polyhydramnios in monochorionic twin placentas, combining (a) data from previous in vitro placental perfusion experiments in singleton term placentas under simulated normal and increased amniotic fluid pressures with (b) logical deduction from observations made in monochorionic twins. Our hypothesis is that in monochorionic placentas, an increased amniotic fluid pressure increases the placental microvascular resistance but not the resistance of placental chorionic plate arteries. Hence, an increased amniotic fluid pressure increases the microvascular resistance of the joint cotyledon, the arterio-venous resistance, but not the arterio-arterial resistance. This proposed mechanism reduces arterio-venous but not oppositely directed arterio-arterial transfusion. Therefore, reversal of the normal direction of net foeto-foetal transfusion may develop, which will reduce the circulatory imbalance that evolved between the monochorionic foetal twins. In contrast, in monochorionic twins connected by unidirectional or bidirectional arterio-venous anastomoses reversal of the normal direction of net foeto-foetal transfusion will not occur. In conclusion, reversal of the normal direction of net foeto-foetal transfusion, induced by polyhydramnios, is protective against the onset and severity of twin-twin transfusion syndrome in monochorionic twins connected by arterio-venous plus arterio-arterial anastomoses, but not by unidirectional or bidirectional arterio-venous anastomoses.

  14. Arterial Stiffness

    PubMed Central

    Avolio, Alberto

    2013-01-01

    Stiffness of large arteries has been long recognized as a significant determinant of pulse pressure. However, it is only in recent decades, with the accumulation of longitudinal data from large and varied epidemiological studies of morbidity and mortality associated with cardiovascular disease, that it has emerged as an independent predictor of cardiovascular risk. This has generated substantial interest in investigations related to intrinsic causative and associated factors responsible for the alteration of mechanical properties of the arterial wall, with the aim to uncover specific pathways that could be interrogated to prevent or reverse arterial stiffening. Much has been written on the haemodynamic relevance of arterial stiffness in terms of the quantification of pulsatile relationships of blood pressure and flow in conduit arteries. Indeed, much of this early work regarded blood vessels as passive elastic conduits, with the endothelial layer considered as an inactive lining of the lumen and as an interface to flowing blood. However, recent advances in molecular biology and increased technological sophistication for the detection of low concentrations of biochemical compounds have elucidated the highly important regulatory role of the endothelial cell affecting vascular function. These techniques have enabled research into the interaction of the underlying passive mechanical properties of the arterial wall with the active cellular and molecular processes that regulate the local environment of the load-bearing components. This review addresses these emerging concepts. PMID:26587425

  15. 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.

  16. Baseline serum levels of cardiac biomarkers in patients with stable coronary artery disease.

    PubMed

    Karacalioglu, O; Arslan, Z; Kilic, S; Oztürk, E; Ozguven, M

    2007-01-01

    Stable coronary artery disease (CAD) can cause repetitive reversible myocardial ischaemia, and it seems to be possible that reversibly injured myocardium releases small amounts of soluble cytoplasmic proteins. Hence, the aim was to evaluate the effect of stable CAD on baseline serum levels of cardiac biomarkers. We studied 68 consecutive outpatients referred for gated myocardial perfusion imaging. Before a treadmill exercise test, blood samples for measurement of creatine kinase (CK), CK-myocardial band (CK-MB) mass, myoglobin, aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were collected. Normal perfusion patterns were detected in 29 (43%) patients (group 1) and perfusion defects were detected in 39 (57%) patients (group 2). Baseline serum levels of biomarkers except CK were significantly higher in group 2 (p=0.001). Stable CAD increases baseline levels of CK-MB mass, myoglobin, AST and LDH in the serum and this increase is related to the extent and severity of the perfusion defect and to some extent the ejection fraction of the left ventricle. PMID:17701751

  17. Reversible ischaemia of right ventricle detected by exercise thallium-201 scintigraphy.

    PubMed Central

    Lahiri, A; Carboni, G P; Crawley, J W; Raftery, E B

    1982-01-01

    Exercise and redistribution thallium-201 imaging is commonly used for the detection and evaluation of left ventricular ischaemia and infarction. The right ventricle is frequently visualised after stress and sometimes on redistribution images. The visualisation of the right ventricle at rest is thought to be abnormal and is suggestive of pressure or volume overload of the right ventricle, either a result of pulmonary hypertension or secondary to left ventricular dysfunction. Using stress and delayed 201Tl imaging we have shown reversible left and right ventricular ischaemia and fixed left ventricular perfusion defects in two patients with multivessel coronary artery disease and left ventricular dyskinesia caused by prior myocardial infarction. Judging by the rarity of this finding as well as taking into consideration 201Tl kinetics, it is suggested that reversible right ventricular ischaemia after exercise may only be detected in patients with coronary artery disease who have severely compromised ventricular function. This finding may have therapeutic and prognostic significance. Images PMID:7104119

  18. Pulmonary perfusion during anesthesia and mechanical ventilation.

    PubMed

    Hedenstierna, G

    2005-06-01

    Cardiac output and the pulmonary perfusion can be affected by anesthesia and by mechanical ventilation. The changes contribute to impeded oxygenation of the blood. The major determinant of perfusion distribution in the lung is the relation between alveolar and pulmonary capillary pressures. Perfusion increases down the lung, due to hydrostatic forces. Since atelectasis is located in dependent lung regions, perfusion of non-ventilated lung parenchyma is common, producing shunt of around 8-10% of cardiac output. In addition, non-gravitational inhomogeneity of perfusion, that can be greater than the gravitational inhomogeneity, adds to impeded oxygenation of blood. Essentially all anaesthetics exert some, although mild, cardiodepressant action with one exception, ketamine. Ketamine may also increase pulmonary artery pressure, whereas other agents have little effect on pulmonary vascular tone. Mechanical ventilation impedes venous return and pushes blood flow downwards to dependent lung regions, and the effect may be striking with higher levels of PEEP. During one-lung anesthesia, there is shunt blood flow both in the non-ventilated and the ventilated lung, and shunt can be much larger in the ventilated lung than thought of. Recruitment manoeuvres shall be directed to the ventilated lung and other physical and pharmacological measures can be taken to manipulate blood flow in one lung anesthesia. PMID:15886595

  19. Peri-infarct ischaemia assessed by cardiovascular MRI: comparison with quantitative perfusion single photon emission CT imaging

    PubMed Central

    Cochet, H; Bullier, E; Ragot, C; Gilbert, S H; Pucheu, Y; Laurent, F; Coste, P; Bordenave, L; Montaudon, M

    2014-01-01

    Objective: To develop a new method for the cardiac MR (CMR) quantification of peri-infarct ischaemia using fused perfusion and delayed–enhanced images and to evaluate this method using quantitative single photon emission CT (SPECT) imaging as a reference. Methods: 40 patients presenting with peri-infarct ischaemia on a routine stress 99mTc-SPECT imaging were recruited. Within 8 days of the SPECT study, myocardial perfusion was evaluated using stress adenosine CMR. Using fused perfusion and delayed–enhanced images, peri-infarct ischaemia was quantified as the percentage of myocardium with stress-induced perfusion defect that was adjacent to and larger than a scar. This parameter was compared with both the percent myocardium ischaemia (SD%) and the ischaemic total perfusion deficit (TPD). The diagnostic performance of CMR in detection of significant coronary artery stenosis (of ≥70%) was also determined. Results: On SPECT imaging, in addition to peri-infarct ischaemia, reversible perfusion abnormalities were detected in a remote zone in seven patients. In the 33 patients presenting with only peri-infarct ischaemia, the agreement between CMR peri-infarct ischaemia and both SD% and ischaemic TPD was excellent [intraclass coefficient of correlation (ICC) = 0.969 and ICC = 0.877, respectively]. CMR-defined peri-infarct ischaemia for the detection of a significant coronary artery stenosis showed an areas under receiver–operating characteristic curve of 0.856 (95% confidence interval, 0.680–0.939). The best cut-off value was 8.1% and allowed a 72% sensitivity, 96% specificity, 60% negative predictive value and 97% positive predictive value. Conclusion: This proof-of-concept study shows that CMR imaging has the potential as a test for quantification of peri-infarct ischaemia. Advances in knowledge: This study demonstrates the proof of concept of a commonly known intuitive idea, that is, evaluating the peri-infarct ischaemic burden by subtracting delayed

  20. The usefulness of a perfusion balloon in a case of late stent thrombosis that caused simultaneous double vessel occlusion.

    PubMed

    Nakabayashi, Keisuke; Okada, Hisayuki; Asano, Ryotaro; Nakazawa, Naomi; Nomura, Hidekimi; Oka, Toshiaki

    2016-07-01

    Simultaneous stent thrombosis in different coronary arteries requires rapid management. A 70-year-old man experienced simultaneous stent thrombosis at the left anterior descending and circumflex arteries. We used a perfusion balloon to prevent thrombus production at the left anterior descending artery, and completed percutaneous coronary intervention at the left circumflex artery in 10 min. The perfusion balloon was dilated during the procedure. In both vessels, Thrombolysis in myocardial infarction flow grade 3 was achieved after balloon deflation. Thus, use of a perfusion balloon for simultaneous double vessel occlusion helped avoid the need for redundant stent placement and shortened the procedure time. PMID:25971225

  1. Noninvasive Blood Perfusion Measurements of an Isolated Rat Liver and an Anesthetized Rat Kidney

    PubMed Central

    Mudaliar, Ashvinikumar V.; Ellis, Brent E.; Ricketts, Patricia L.; Lanz, Otto I.; Lee, Charles Y.; Diller, Thomas E.; Scott, Elaine P.

    2008-01-01

    A simple, cost effective, and noninvasive blood perfusion system is tested in animal models. The system uses a small sensor to measure the heat transfer response to a thermal event (convective cooling) imposed on the tissue surface. Heat flux data are compared with a mathematical model of the tissue to estimate both blood perfusion and thermal contact resistance between the tissue and the probe. The perfusion system was evaluated for repeatability and sensitivity using isolated rat liver and exposed rat kidney tests. Perfusion in the isolated liver tests was varied by controlling the flow of the perfusate into the liver, and the perfusion in the exposed kidney tests was varied by temporarily occluding blood flow through the renal artery and vein. The perfusion estimated by the convective perfusion probe was in good agreement with that of the metered flow of the perfusate into the liver model. The liver tests indicated that the probe can be used to detect small changes in perfusion (0.005 ml/ml/s). The probe qualitatively tracked the changes in the perfusion in the kidney model due to occlusion of the renal artery and vein. PMID:19045542

  2. 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…

  3. 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

  4. Development of an Ex Vivo, Beating Heart Model for CT Myocardial Perfusion

    PubMed Central

    Pelgrim, Gert Jan; Das, Marco; Haberland, Ulrike; Slump, Cees; Handayani, Astri; van Tuijl, Sjoerd; Stijnen, Marco; Klotz, Ernst; Oudkerk, Matthijs; Wildberger, Joachim E.; Vliegenthart, Rozemarijn

    2015-01-01

    Objective. To test the feasibility of a CT-compatible, ex vivo, perfused porcine heart model for myocardial perfusion CT imaging. Methods. One porcine heart was perfused according to Langendorff. Dynamic perfusion scanning was performed with a second-generation dual source CT scanner. Circulatory parameters like blood flow, aortic pressure, and heart rate were monitored throughout the experiment. Stenosis was induced in the circumflex artery, controlled by a fractional flow reserve (FFR) pressure wire. CT-derived myocardial perfusion parameters were analysed at FFR of 1 to 0.10/0.0. Results. CT images did not show major artefacts due to interference of the model setup. The pacemaker-induced heart rhythm was generally stable at 70 beats per minute. During most of the experiment, blood flow was 0.9–1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg. Blood flow decreased and arterial pressure increased by approximately 10% after inducing a stenosis with FFR ≤ 0.50. Dynamic perfusion scanning was possible across the range of stenosis grades. Perfusion parameters of circumflex-perfused myocardial segments were affected at increasing stenosis grades. Conclusion. An adapted Langendorff porcine heart model is feasible in a CT environment. This model provides control over physiological parameters and may allow in-depth validation of quantitative CT perfusion techniques. PMID:26185756

  5. A novel dual ex vivo lung perfusion technique improves immediate outcomes in an experimental model of lung transplantation.

    PubMed

    Tanaka, Y; Noda, K; Isse, K; Tobita, K; Maniwa, Y; Bhama, J K; D'Cunha, J; Bermudez, C A; Luketich, J D; Shigemura, N

    2015-05-01

    The lungs are dually perfused by the pulmonary artery and the bronchial arteries. This study aimed to test the feasibility of dual-perfusion techniques with the bronchial artery circulation and pulmonary artery circulation synchronously perfused using ex vivo lung perfusion (EVLP) and evaluate the effects of dual-perfusion on posttransplant lung graft function. Using rat heart-lung blocks, we developed a dual-perfusion EVLP circuit (dual-EVLP), and compared cellular metabolism, expression of inflammatory mediators, and posttransplant graft function in lung allografts maintained with dual-EVLP, standard-EVLP, or cold static preservation. The microvasculature in lung grafts after transplant was objectively evaluated using microcomputed tomography angiography. Lung grafts subjected to dual-EVLP exhibited significantly better lung graft function with reduced proinflammatory profiles and more mitochondrial biogenesis, leading to better posttransplant function and compliance, as compared with standard-EVLP or static cold preservation. Interestingly, lung grafts maintained on dual-EVLP exhibited remarkably increased microvasculature and perfusion as compared with lungs maintained on standard-EVLP. Our results suggest that lung grafts can be perfused and preserved using dual-perfusion EVLP techniques that contribute to better graft function by reducing proinflammatory profiles and activating mitochondrial respiration. Dual-EVLP also yields better posttransplant graft function through increased microvasculature and better perfusion of the lung grafts after transplantation. PMID:25777770

  6. Echocardiographic analysis of regional left ventricular wall motion in children after the arterial switch operation for complete transposition of the great arteries

    SciTech Connect

    Vogel, M.; Smallhorn, J.F.; Trusler, G.A.; Freedom, R.M. )

    1990-05-01

    Regional left ventricular wall motion was assessed by two-dimensional echocardiography in 21 patients with complete transposition of the great arteries at a mean of 2.2 years (range 0.3 to 7) after an arterial switch operation. Fourteen patients had undergone a two-stage and seven patients a primary repair. Twenty patients were found to have echocardiographic images adequate for wall motion analysis. The results of these studies were correlated with thallium-201 myocardial perfusion scans. Left ventricular wall motion was assessed by measuring regional area change in parasternal and apical views. After planimetry of an end-systolic and an end-diastolic frame, the ventricle was divided into eight equal segments and the percent area change was calculated. Both a fixed reference and a floating system correcting for translation and rotation were applied. The measurements in the patient group were compared with normal age-matched values previously obtained in 55 normal infants and children. Wall motion abnormalities, found in seven patients, were located at the apex in three, at the inferior septum and anterolateral wall in one and the inferior, anterolateral and lateral walls in one patient each. All had a myocardial perfusion defect in a corresponding anatomic location. One patient with a small reversible perfusion defect at the basilar septum had normal regional wall motion. The sensitivity of detecting impairment of myocardial perfusion was 0.95. Wall motion abnormalities were found only in patients who had undergone a two-stage repair. Echocardiographic wall motion analysis can be used as a screening method to identify patients with suspected myocardial ischemia after the arterial switch operation.

  7. 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.

  8. 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.

  9. 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.

  10. Renal vascular perfusion index in a canine model.

    PubMed

    Shau, Yio-Wha; Pao, Sun-Hua; Chou, Nai-Kuan; Chang, King-Jen; Shyu, Jeou-Jong

    2009-01-01

    Decreased renal perfusion plays an important role in the progression toward renal failure. In this study, a novel measure was proposed to quantify renal perfusion using canine model. Serial renal vascular images at different vascular areas including the whole vascular tree, interlobar, arcuate and interlobular vessels were captured. Image processing software was designed to analyze the changes of power Doppler intensity of colored pixels within regions-of-interest (ROI). For a given ROI, the power Doppler vascular index (PDVI) was found to fluctuate with the cardiac cycle. It was also noted that the power Doppler signals generated by arterial vessels have different fluctuating waveforms and different phase compared with the signal derived from venous vessels. A power Doppler correlation-map was developed to differentiate the arteries and veins in the ROI. Using the serial power Doppler images and the derived flow direction information, the interlobular perfusion can be strongly quantified. The renal vascular perfusion index (RVPI) defined as the ratio of PDVI(max) versus PDVI(min) was significantly higher in the interlobular vessel areas than three other areas for seven healthy dogs. The RVPI resembles the systolic/diastolic (S/D) ratio that commonly reflects arterial hemodynamics. RVPI and power Doppler correlation-map reveal more "dynamic" sense of vascular perfusion and provide a novel approach for the examination of renal function in clinical practice. PMID:18805627