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81.
Turner DA; Alcorn FS; Shorey WD; Stelling CB; Mategrano VC; Merten CW; Silver B; Economou SG; Straus AK; Witt TR 《Radiology》1988,168(1):49-58
Detectability of breast cancer with magnetic resonance (MR) imaging versus xeromammography was quantitatively compared. MR images were obtained of breasts of 120 women who underwent xeromammography. T1 values were determined for masses larger than 2 cm. Cancer was histologically confirmed in 39 breasts and was considered excluded from 81 due to results of biopsy, cyst aspiration, or sonography or absence of change in xeromammographic findings over time. Images were blindly interpreted by three observers, and results were expressed as receiver operating characteristic curves. Detectability of breast cancer was substantially better with xeromammography than with MR imaging for all observers (P less than .03, 10(-6), and .001). On MR images, spiculation of a mass, distorted architecture, skin thickening, and nipple or skin retraction were specific but relatively insensitive indicators of cancer. Masses with smooth, distinct margins and signal intensity greater than that of fat on T2-weighted images were always benign. Other findings and T1 values were not diagnostically useful. The authors conclude that xeromammography is superior to MR imaging in detection of breast cancer. 相似文献
82.
Pflugfelder PW; Wendland MF; Holt WW; Quay SC; Worah D; Derugin N; Higgins CB 《Radiology》1988,167(1):129-133
Cardiac-gated magnetic resonance (MR) imaging was performed in rats to determine the effects of manganese ethylenediaminetetraphosphonate (TP). Ten normal rats received Mn-TP in a dose of 50 mumol/kg through a tail-vein injection. Spin-echo MR images were obtained before and every 10 minutes after Mn-TP injection for 1 hour. Cardiac signal intensity (SI) increased more than 70% after Mn-TP injection and remained nearly unchanged 1 hour after injection. Myocardial T1 was 517 +/- 49 msec in eight control rats and 282 +/- 61 msec (P less than .001) in six rats 81 +/- 0 minutes after injection. Nine rats underwent occlusion of the left anterior descending coronary artery prior to MR imaging. Images were obtained before and 15, 30, and 60 minutes after Mn-TP injection. In normal myocardium, SI increased up to 82% and remained elevated for 1 hour. In ischemic myocardium, SI rose 11%, leading to a marked contrast between the two tissue zones. T1 was also different in the two regions: In normal tissue, it was 206 msec +/- 54; in ischemic tissue, 338 +/- 82 (P less than .001). With T1-weighted MR imaging, Mn-TP showed a potential for delineating the jeopardized area after acute myocardial ischemia. 相似文献
83.
84.
85.
Blood flow imaging with MR: spin-phase phenomena 总被引:2,自引:0,他引:2
Blood flow phenomena occurring when flow is within the magnetic resonance (MR) imaging plane were analyzed. In this situation, the signal intensity of vascular lumina is predominantly determined by spin-phase change phenomena, and section transition effects of moving spins can be neglected. In this paper, we develop the concepts of in-plane flow, with emphasis on the notion that the spatial variations in velocity and acceleration of blood, which mainly occur along vessel walls, are important determinants of intravascular signal loss in MR images. Flow patterns in the large mediastinal arteries were qualitatively and quantitatively analyzed in six healthy subjects and 14 patients with hemodynamic abnormalities using multiple electrocardiograph-gated image acquisition; ungated studies of 30 patients were analyzed for venous flow effects. Intraluminal signal was strongly dependent on the phase of the cardiac cycle and the echo number. Signal loss was found to occur along vessel walls, in vascular bends, and at bifurcations. 相似文献
86.
Trevisan M Dorn J Falkner K Russell M Ram M Muti P Freudenheim JL Nochajaski T Hovey K 《Addiction (Abingdon, England)》2004,99(3):313-322
Aims Alcohol consumption has been associated with a reduced risk of heart disease incidence and mortality. However, most studies have focused on an average volume per specific time period and have paid little attention to the pattern of drinking. The aim of this study was to examine the association between various drinking patterns and myocardial infarction (MI). Design A population‐based case–control study. Methods Participants were 427 white males with incident MI and 905 healthy white male controls (age 35–69 years) selected randomly from two Western New York counties. During computer‐assisted interviews detailed information was collected regarding patterns of alcohol consumption during the 12–24 months prior to interview (controls) or MI (cases). Findings Compared to life‐time abstainers, adjusted odds ratios (ORs) and 95% confidence interval (CI) for non‐current and current drinkers were 0.66 (0.31–1.39) and 0.50 (0.24–1.02), respectively. Daily drinkers exhibited a significantly lower OR (0.41) compared to life‐time abstainers. Participants who drank mainly without food had an OR of 1.49 (0.96–2.31) compared to those who drank mainly with food and 0.62 (0.28–1.37) compared to life‐time abstainers. Men who reported drinking only at weekends had a significantly greater MI risk [1.91; (1.21–3.01)] compared to men who drank less than once/week, but not compared to life‐time abstainers [0.91 (0.40–2.07)]. Conclusions Our results indicate that patterns of alcohol use have important cardiovascular health implications. 相似文献
87.
CF Samer Y Daali M Wagner G Hopfgartner CB Eap MC Rebsamen MF Rossier D Hochstrasser P Dayer JA Desmeules 《British journal of pharmacology》2010,160(4):919-930
Background and purpose:
Thrombus formation is commonly associated with pulmonary arterial hypertension (PAH). Thrombin may thus play an important role in the pathogenesis and pathophysiology of PAH. Hence, we investigated the contractile effects of thrombin and its mechanism in pulmonary artery.Experimental approach:
The cytosolic Ca2+ concentrations ([Ca2+]i), 20 kDa myosin light chain (MLC20) phosphorylation and tension development were evaluated using the isolated porcine pulmonary artery.Key results:
Thrombin induced a sustained contraction in endothelium-denuded strips obtained from different sites of a pulmonary artery, ranging from the main pulmonary artery to the intrapulmonary artery. In the presence of endothelium, thrombin induced a transient relaxation. The contractile effect of thrombin was abolished by either a protease inhibitor or a proteinase-activated receptor 1 (PAR1) antagonist, while it was mimicked by PAR1-activating peptide (PAR1AP), but not PAR4AP. The thrombin-induced contraction was associated with a small elevation of [Ca2+]i and an increase in MLC20 phosphorylation. Thrombin and PAR1AP induced a greater increase in tension for a given [Ca2+]i elevation than that obtained with high K+-depolarization. They also induced a contraction at a fixed Ca2+ concentration in α-toxin-permeabilized preparations.Conclusions and implications:
The present study revealed a unique property of the pulmonary artery. In contrast to normal arteries of the systemic circulation, thrombin induces a sustained contraction in the normal pulmonary artery, by activating PAR1 and thereby increasing the sensitivity of the myofilament to Ca2+. This responsiveness of the pulmonary artery to thrombin may therefore contribute to the pathogenesis and pathophysiology of PAH. 相似文献88.
89.
Ollendick TH Jarrett MA Grills-Taquechel AE Hovey LD Wolff JC 《Clinical psychology review》2008,28(8):1447-1471
In the present review, we examine one of the critical issues that have been raised about evidence-based treatments and their portability to real-world clinical settings: namely, the presence of comorbidity in the participants who have been treated in these studies and whether the presence of comorbidity predicts or moderates treatment outcomes. In doing so, we examine treatment outcomes for the four most commonly occurring childhood psychiatric disorders: Anxiety disorders, affective disorders, attention deficit/hyperactivity disorder (ADHD), and oppositional defiant disorder (ODD)/conduct disorder (CD). For each of these disorders, we first review briefly the prevalence of comorbidity in epidemiological and clinical samples and then highlight the evidence-based treatments for these disorders. We next determine the effects of comorbidity on treatment outcomes for these disorders. For the most part, comorbidity in the treated samples is the rule, not the exception. However, the majority of studies have not explored whether comorbidity predicts or moderates treatment outcomes. For the not insignificant number of studies that have examined this issue, comorbidity has not been found to affect treatment outcomes. Notable exceptions are highlighted and recommendations for future research are presented. 相似文献
90.
Dimoska A Butow PN Lynch J Hovey E Agar M Beale P Tattersall MH 《Patient education and counseling》2012,86(2):252-258