Biomedical subjects

C Waller

Publications and source records attributed to C Waller.

At least 19 recordsLinked to original sources

PubMed2004

[French training program for medical students in transfusion medicine. Transfusion Medicine Teachers' College].

In France, transfusion medicine training program has been updated. A national committee of professors in transfusion medicine propose a series of 13 items which represent the minimum knowledge that general practitioners should possess. This overview of transfusion medicine is far below the level that specialists should reach and they will need an additional specialized training. Several French universities have set up their own training program which is quite similar to the work of the committee of professors. The following recommendations are not strict guidelines but is a common basis which will be improved in 2005 according to new evidence based transfusion medicine.

Accidents, Occupational↗

PubMed2004

[The overexpression of NCAM (CD56) in human hearts is specific for ischemic damage].

The main reason for myocardial dysfunction is chronical myocardial ischemia. Recently we could show, that NCAM (CD56), a neural cell adhesion molecule and member of the immunoglobuline superfamily, and the transcription factor AML1 (RUNX1) are overexpressed in chronic ischemic human heart failure compaired to normal hearts. Here we demonstrate, that the overexpression of NCAM (CD56) is specific for ischemic damage as compaired to other heart diseases including congestive cardiomyopathy, hypertrophic obstrutive cardiomyopathy, myocarditis and sarcoidosis. Concerning the transcriptional regulation of NCAM (CD56) by AML1 (RUNX1) we isolated 3 novel isoforms of AML 1 (RUNX1) with different transactivating function, that might be a regulatory element of the NCAM (CD56) overexpression in chronical myocardial ischemia.

Adult↗

PubMed2003

[Are the indications and choice of labile blood products adapted? National survey on prescriber's knowledge].

OBJECTIVE: There is little data available on current practice related to prescription of labile blood products (LBP) by French physicians. The aim of this study was to assess whether prescriptions were conform to Anaes (French Medicine's agency) guidelines, with regard not only to indications but also quality of the products, so as to define the improvements that could be made. METHOD: Thirty-four clinical case reports, classified by specialties were sent to prescribing physicians working in the regional health centers, from 17 different blood banks, from October 1997 to February 1998. The prescribers were requested to answer only the questions that were specific to their particular field of experience. Each case description included multiple choice questions on the indication for transfusion of concentrated of red blood cells (RBC) and/or platelets (CP) and/or plasma, and the possible requirements for specification or modification of the guidelines applicable to these products. The primary end point of analysis was the adequation of the answers to the Anaes recommendations. RESULTS: Answers were obtained regarding 5092 clinical cases from 818 physicians. The participation rate was of 30%. The specialties were as follows: 34% anesthesiologists, 14% oncologists-haematologists, 13% internal medicine specialists, 11% emergency physicians, 10% paediatricians, 8% obstetricians, 7% geriatricians, and 3% transplantation surgeons. Eighty-two percent of the answers came from physicians working in the public health services. The adequation with the indication for transfusion was of 90.3% for RBC, 92.3% for platelets and 93.8% for plasma. The percentages of correct answers regarding the indications for specification or modification of the LBP were as follows: 90.3% were correct for irradiation (of either RBC or platelets); 68.8% and 53.2% respectively for leukocyte depletion from RBC and platelets; 64% for phenotyped RBC; 68.2% for compatibilized RBC; and 57.3% for apheresis platelet concentrates. There was no difference in results depending on the type of center, private or public, and the quality of LBP prescribed. The answers obtained from the anaesthesiologists' clinical cases were less accurate with regard to RBC but more accurate with regard to PC compared with other specialists. CONCLUSION: This study shows the correct management of the indications for transfusion by the prescribing physicians who participated in the study, but the lack of knowledge with regard to the indications for specifications and/or transformations of LBP. The respect of the indications for transfusion is the corner stone of safe transfusion and this phase should be optimized with improved dissemination of information on transfusion and training for the physicians and programs that would improve the quality.

Blood Component Transfusion↗

PubMed2003

Dynamics of BCR-ABL mRNA expression in first-line therapy of chronic myelogenous leukemia patients with imatinib or interferon alpha/ara-C.

We sought to determine dynamics of BCR-ABL mRNA expression levels in 139 patients with chronic myelogenous leukemia (CML) in early chronic phase, randomized to receive imatinib (n=69) or interferon (IFN)/Ara-C (n=70). The response was sequentially monitored by cytogenetics from bone marrow metaphases (n=803) and qualitative and quantitative RT-PCR from peripheral blood samples (n=1117). Complete cytogenetic response (CCR) was achieved in 60 (imatinib, 87%) vs 10 patients (IFN/Ara-C, 14%) after a median observation time of 24 months. Within the first year after CCR, best median ratio BCR-ABL/ABL was 0.087%, (imatinib, n=48) vs 0.27% (IFN/Ara-C, n=9, P=0.025). BCR-ABL was undetectable in 25 cases by real-time PCR, but in only four patients by nested PCR. Median best response in patients with relapse after CCR was 0.24% (n=3) as compared to 0.029% in patients with continuous remission (n=52, P=0.029). We conclude that (i) treatment with imatinib in newly diagnosed CML patients is associated with a rapid decrease of BCR-ABL transcript levels; (ii) nested PCR may reveal residual BCR-ABL transcripts in samples that are negative by real-time PCR; (iii) BCR-ABL transcript levels parallel cytogenetic response, and (iv) imatinib is superior to IFN/Ara-C in terms of the speed and degree of molecular responses, but residual disease is rarely eliminated.

Adult↗

PubMed2002

An integrated "4-phase" approach for setting endocrine disruption screening priorities--phase I and II predictions of estrogen receptor binding affinity.

Recent legislation mandates the US Environmental Protection Agency (EPA) to develop a screening and testing program for potential endocrine disrupting chemicals (EDCs), of which xenoestrogens figure prominently. Under the legislation, a large number of chemicals will undergo various in vitro and in vivo assays for their potential estrogenicity, as well as other hormonal activities. There is a crucial need for priority setting before this strategy can be effectively implemented. Here we report an integrated computational approach to priority setting using estrogen receptor (ER) binding as an example. This approach rationally integrates different predictive computational models into a "Four-Phase" scheme so that it can effectively identify potential estrogenic EDCs based on their predicted ER relative binding affinity (RBA). The system has been validated using an in-house ER binding assay dataset for 232 chemicals that was designed to have both broad structural diversity and a wide range of binding affinities. When applied to 58,000 chemicals identified by Walker et al. as candidates for endocrine disruption screening, some 9100 chemicals were predicted to bind to ER. Of these, only 3600 were expected to bind to ER at RBA values up to 100,000-fold less than that of 17beta-estradiol. The method ruled out 83% of the chemicals as non-binders with a very low rate of false negatives. We believe that the same integrated scheme will be equally applicable to endpoints of other endocrine disrupting mechanisms, e.g. androgen receptor binding.

Biological Assay↗

PubMed2001

The HCA National Disease Management Program for coronary disease detection and treatment in women.

The diagnosis and treatment of heart disease in women continues to be one of the greatest challenges facing cardiovascular medicine today. Marked reductions in mortality rates during the past 2 decades did not result in improved outcomes for women. A major rate-limiting step to improving mortality rates for women is early diagnosis and initiation of effective lifesaving therapies for women. In 1999, HCA Healthcare Systems, Inc, Nashville, TN, initiated a coordinated effort among 208 hospitals in 26 states to improve the diagnosis of coronary disease and to target women who should receive aggressive risk factor modification and referral to cardiologists. We describe the initial phases of program development, including employee risk factor screening; citywide health risk assessment; nationwide educational programs for clinicians, staff, and consumers; and a dedicated outcomes assessment program for tracking women at risk for coronary disease. We believe that these efforts provide a venue for optimal care and improved outcomes for women served by HCA facilities.

Coronary Disease↗

PubMed2001

Serial magnetic resonance imaging of microvascular remodeling in the infarcted rat heart.

BACKGROUND: Alterations in the coronary circulation are important determinants of myocardial function. Few data are available, however, about microvascular changes in reactive hypertrophy. With MRI, serial determination of myocardial microcirculation after myocardial infarction (MI) is feasible. METHODS AND RESULTS: We quantitatively determined myocardial perfusion and relative intracapillary blood volume using an MRI technique. Infarct size, myocardial mass, and left ventricular volumes were determined with cine MRI. Rats were investigated at 8, 12, and 16 weeks after MI (mean MI size 24.1+/-2.0%) or sham operation. Vasodilation was induced by adenosine. In the infarcted group, maximum perfusion decreased significantly from 8 to 16 weeks (5.6+/-0.3 versus 3.5+/-0.2 mL. g(-1). min(-1), P<0.01) compared with sham animals (5.5+/-0.3 versus 5.0+/-0.2 mL. g(-1). min(-1), P=0.17). Myocardial mass increased significantly (559.1+/-20.8 mg at 8 weeks versus 690.9+/-42.7 mg at 16 weeks, P<0.05) compared with sham-operated animals (516.3+/-41.7 versus 549.2+/-32.3 mg). Basal relative intracapillary blood volume increased significantly to 15.7+/-0.5 vol% at 8 weeks after MI and remained elevated (16.8+/-0.6 vol%) at 16 weeks compared with 12.1+/-0.3 vol% (P<0.01) in sham-operated rats. CONCLUSIONS: Our results indicate that significant microvascular changes occur during cardiac remodeling. Hypoperfusion in the hypertrophied myocardium is related to an increase in vascular capacity, suggesting a compensatory vasodilatory response at the capillary level. These microvascular changes may therefore contribute to the development of heart failure.

Animals↗

PubMed2001

Fast high-resolution magnetic resonance imaging demonstrates fractality of myocardial perfusion in microscopic dimensions.

The fractal nature of heterogeneity of myocardial blood flow and its implications for the healthy and diseased heart is not yet understood. The main hindrance for investigation of blood flow heterogeneity and its role in physiology and pathophysiology is that conventional methods for determination of myocardial perfusion have severe limitations concerning temporal and spatial resolution and invasiveness. In isolated rat hearts, we developed a nuclear magnetic resonance technique that does not depend on contrast agents and in which the apparent longitudinal relaxation time is made perfusion sensitive by selective preparation of the imaging slice. This perfusion-sensitive relaxation time is determined within 40 seconds as a map with a high spatial in-plane resolution of 140x140 microm(2) and a thickness of 1.5 mm. Perfusion imaging was validated with the established microsphere technique. Additionally, the congruence between perfusion-sensitive T:(1) maps and first-pass perfusion imaging was demonstrated. As an application of high-resolution perfusion imaging, fractal analysis of the spatial distribution of perfusion was performed. We were able to demonstrate that the fractality of this distribution exists even in microscopic dimensions. Vasodilation by nitroglycerin modulated the fractal pattern of perfusion, and the decrease of the fractal dimension indicated a shift toward homogeneity. This implies that parameters of the fractal distribution depend on the microvascular tone rather than on anatomic preformations; ie, fractality is a functional characteristic of perfusion.

Animals↗

PubMed2001

Serial cine-magnetic resonance imaging of left ventricular remodeling after myocardial infarction in rats.

The purpose of the present study was the serial investigation of morphological and functional changes after left coronary artery ligation in the intact rat using cine-magnetic resonance imaging (MRI). MRI studies were performed 4, 8, 12, and 16 weeks after myocardial infarction (MI) with an echocardiogram (ECG)-triggered cine-fast low-angle shot (FLASH)-sequence in a 7-Tesla magnet. MI-size, left ventricular (LV) mass and volumes, cardiac index, ejection fraction (EF), and remote wall and scar thickness of 11 Wistar rats were compared to four sham-operated rats. Stress MRI with dobutamine (10 microl/kg x minute) was performed at 16 weeks. In MI groups (small MI < 30%, N = 5, large MI > 30%, N = 6), there was significant increase of LV mass (small MI + 47.8% increase, large MI + 74.1%) and wall thickness (large MI 1.21 +/- 0.03 to 1.84 +/- 0.07 mm). Scar thickness declined from four to 16 weeks (large MI 0.92 +/- 0.06 to 0.38 +/- 0.02 mm, P < 0.05). End-diastolic volume of both MI groups was significantly elevated but increased further only in animals with large MI from four to 16 weeks (657.1 +/- 38.6 to 869.7 +/- 60.7 microL, P < 0.05). Compared to sham, EF was significantly depressed in MI (large MI 31.5 +/- 2.0%). Wall thickening declined from four to 16 weeks post-MI (large MI 50.9 +/- 9.9 to 28.9 +/- 4.4%, P < 0.05). During stress, sham and MI rats increased wall thickening from 66.5 +/- 8.2 to 111.2 +/- 6.7% and from 30.8 +/- 4.3 to 47.5 +/- 5.8%, respectively (P < 0.05). Hypertrophy was found in all animals with MI throughout the entire period of observation, whereas dilatation after four weeks was only detected in animals with large MI. These morphologic changes were accompanied by an early decline of EF; myocardial function characterized by wall thickening deteriorated later.

Animals↗

PubMed2001

Combined high-speed NMR imaging of perfusion and microscopic coronary conductance vessels in the isolated rat heart.

Noninvasive characterization of microcirculation at the level of both coronary conductance and resistance vessels is of major importance for the understanding of microvascular adaptive processes in the heart. The objective of this study was to determine simultaneously myocardial perfusion and microvessel diameters in the myocardium by magnetic resonance (MR) imaging within the same heart. A MR imaging method is presented which combines high-resolution perfusion measurement (140 x 140 microm2) by spin labeling with flow-weighted MR microscopy of coronary microvessels (phi > 140 microm). We determined changes in myocardial perfusion and vessel diameters of isolated beating rat hearts (n = 10) at rest and during administration of nitroglycerin (0.5 mg/min). Alterations in perfusion were validated by microsphere measurements. Under the influence of nitroglycerin an increase in perfusion (+2.51 +/- 0.4 ml x min(-1) x g(-1), mean +/- SEM) and vessel diameters (+14.22 +/- 1.92%) could be observed. Endocardial perfusion revealed a modest enhanced susceptibility to nitroglycerin in comparison to epicardial perfusion. Analysis of vessels according to their diameters showed no significant differences. MR imaging allows the noninvasive and simultaneous determination of conducting arteries and smaller resistance vessels in one and the same beating rat heart. Due to an excellent spatial resolution of these methods, transmural characterization of both parameters at rest and during vasodilation is feasible.

Animals↗

PubMed2001

Myocardial perfusion imaging using a non-contrast agent MR imaging technique.

INTRODUCTION: A MR imaging (MRI) method has been developed to determine quantitatively myocardial perfusion (P) in the rat heart in vivo. This method has the potential to non-invasively measure cardiac perfusion without the use of a contrast agent by exploiting the endogenous contrast from flowing blood itself. METHOD AND RESULTS: Principle of the technique is the arterial spin labeling of endogenous water protons within the short axis imaging slice. Arterial spin labeling techniques are based on a model that uses inflow effects to relate intrinsic changes in longitudinal relaxation (T1) to tissue perfusion. Perfusion is determined from the difference between a slice selective and a global inversion recovery experiment. Perfusion was determined at rest and during hyperemia induced by intravenous adenosine (3 mg/(kg min)). The MR perfusion values were compared with perfusion data obtained in the same animal using the colored microspheres (MS) technique as the gold standard. The MR perfusion (mean +/- SEM) was 3.3 +/- 0.2 ml/min/g at rest and 4.6 +/- 0.6 ml/min/g during adenosine. Perfusion values obtained by colored MS were 3.4 +/- 0.2 and 4.7 +/- 0.8 ml/min/g at rest and during vasodilation, respectively. Adenosine decreased mean arterial pressure (MAP) from 120 to 65 mmHg which implies a reduction of coronary resistance (CR) to about 50% of baseline. CONCLUSION: Our study shows that quantitative mapping of perfusion may be performed non-invasively by MRI. The MR perfusion data are in excellent correlation with data obtained by the well-established colored MS technique. Determination of perfusion reserve confirms that coronary perfusion is highly dependent on blood pressure due to changes in CR.

Animals↗

PubMed2001

Safety of human albumin based on spontaneously reported serious adverse events.

OBJECTIVE: To evaluate the safety of human albumin administered for therapeutic purposes. DESIGN: Retrospective compilation of spontaneously reported serious adverse events. SETTING: Records of serious adverse event reports received from 1990 through 1997 by nine major suppliers of therapeutic human albumin worldwide. PATIENTS: Primarily hospitalized patients. INTERVENTIONS: Administration of human albumin. MEASUREMENTS AND MAIN RESULTS: The number of 40-g doses distributed by the nine suppliers during the study period was 95.4 x 10(6), corresponding to 3.82 x 10(6) kg albumin, and reported serious adverse events totaled 123. The incidence of all serious adverse events was 1.29 per 10(6) doses (95% confidence interval, 1.07 per 10(6) to 1.54 per 10(6) doses). No patient death was judged to be probably attributable to albumin administration. The incidence of fatal serious adverse events possibly related to albumin was 5.24 per 10(8) doses (95% confidence interval, 1.70 per 10(8) to 12.24 per 10(8) doses). CONCLUSIONS: Although underreporting must be recognized as a limitation of spontaneous adverse event reports, this study encompassing approximately 100 million albumin doses provides evidence that both nonfatal and fatal serious adverse events in albumin recipients are very rare. These results provide further support for the excellent long-term safety record of human albumin.

Adverse Drug Reaction Reporting Systems↗

PubMed2001

Differential effects of emotional content on event-related potentials in word recognition memory.

The aim of this study was to delineate the influence of the emotional content of stimuli to be remembered on the recognition performance of normal subjects by means of the event-related potential (ERP) technique. When words are presented repeatedly, brain responses to repeated and recognized items are characterized by a more positive waveform, referred to as "old/new effect". Words judged for their emotional connotation ("negative", "positive" and "neutral") were presented successively on a video monitor to subjects, who had the task to indicate whether a given word occurred for the first ("new") or second ("old") time within the list by pressing one of two buttons. For each word category, the ERPs of the old words were more positive compared to those of the new items from about 250 ms after stimulus. The old/new effect was significantly enhanced for the negative and positive items compared to the neutral stimuli between 450 and 650 ms after stimulus pointing to a significant influence of the emotional content of words on verbal memory processes. This paradigm appears to be feasible to investigate interactions of emotion and cognition in psychiatric patients.

Adult↗

PubMed2000

Emotion/cognition-coupling in word recognition memory of depressive patients: an event-related potential study.

Depressive patients show deficits in memory functions. However, the underlying mechanisms remain unclear. Experiments with a special emphasis on the link between emotion and cognition appear challenging. The aim of this study is to investigate the influence of the emotional content of words on memory in non-medicated depressive patients (n=11) compared with a control group (n=11) utilizing event-related brain potentials (ERPs). In a continuous word recognition paradigm brain responses to repeated items are characterized by more positive waveforms of ERPs. This recognition effect ('old/new effect') has been shown to be sensitive to parameters relevant for memory processing. For the purpose of this ERP experiment visually presented words were classified into three different categories of emotional content. The ERPs for the correctly detected 'old' (repeated) words showed an increased positivity beginning approximately 250 ms post-stimulus, concurring with a good recognition performance. In addition, old/new effect and behavioral data were sensitive to words' different emotional connotations in the control group. In contrast, the depressive patients performed worse and showed no significant old/new effect. Nevertheless, their recognition performance was also enhanced by the emotional content. Furthermore, a differential effect of the emotional content on frontal ERPs was found between groups. In contrast to the control group, a reduced old/new effect indicates a reduced working memory capacity in the moderately depressed patients. This is suggested to be partially due to changes of the emotion/cognition coupling related to ruminations with preferably negative emotional connotation. However, the emotional content also affects recognition performance in the depressive patients.

Adult↗

PubMed2000

The practice of structure activity relationships (SAR) in toxicology.

Both qualitative and quantitative modeling methods relating chemical structure to biological activity, called structure-activity relationship analyses or SAR, are applied to the prediction and characterization of chemical toxicity. This minireview will discuss some generic issues and modeling approaches that are tailored to problems in toxicology. Different approaches to, and some facets and limitations of the practice and science of, SAR as they pertain to current toxicology analyses, and the basic elements of SAR and SAR-model development and prediction systems are discussed. Other topics include application of 3-D SAR to understanding of the propensity of chemicals to cause endocrine disruption, and the use of models to analyze biological activity of metal ions in toxicology. An example of integration of knowledge pertaining to mechanisms into an expert system for prediction of skin sensitization to chemicals is also discussed. This minireview will consider the utility of modeling approaches as one component for better integration of physicochemical and biological properties into risk assessment, and also consider the potential for both environmental and human health effects of chemicals and their interactions.

Animals↗

PubMed2000

Myocardial perfusion and intracapillary blood volume in rats at rest and with coronary dilatation: MR imaging in vivo with use of a spin-labeling technique.

PURPOSE: To validate a magnetic resonance (MR) imaging technique that is not first pass and that reveals perfusion and regional blood volume (RBV) in the intact rat. MATERIALS AND METHODS: Measurement of perfusion was based on the perfusion-sensitive T1 relaxation after magnetic spin labeling of water protons. RBV was determined from steady-state measurements of T1 before and after administration of an intravascular contrast agent. The colored microsphere technique was used as a reference method for perfusion measurement. RBV and perfusion maps were obtained with the rats at rest and during administration of 3 mg of adenosine phosphate per kilogram of body weight per minute. RESULTS: At MR imaging, perfusion during resting conditions was 3.5 mL/g/min +/- 0.1 (SEM), and RBV was 11.6% +/- 0.6 (SEM). Adenosine phosphate significantly increased perfusion to 4.5 mL/g/min +/- 0.3 (SEM) and decreased mean arterial pressure from 120 mm Hg to 65 mm Hg, which implies a reduction of coronary resistance to 40% of baseline. RBV increased consistently to 23.8% +/- 0.6 (SEM). CONCLUSION: The study results show that quantitative mapping of perfusion and RBV may be performed noninvasively by means of MR imaging in the intact animal. The presented method allows determination of vasodilative and perfusion reserve, which reflects the in vivo regulation of coronary microcirculation for a given stimulus.

Adenosine↗

PubMed2000

In vivo assessment of cardiac remodeling after myocardial infarction in rats by cine-magnetic resonance imaging.

The rat infarct model offers important parallels to the process of remodeling after myocardial infarction (MI) in humans. The aim of this study was to test the feasibility of cine fast low-angle shot (FLASH) magnetic resonance imaging (MRI) for assessment of the infarcted and noninfarcted rat heart and to compare the results with established methods. In group A, MRI was done 8-16 weeks after MI on a 7-T scanner using an electrocardiogram-triggered cine-FLASH sequence. We determined left ventricular (LV) volumes and mass, wall thickness, MI size, cardiac output, and ejection fraction. Afterward, MI size was histologically determined. In group B, after MRI eight controls and eight rats 16 weeks after MI underwent conventional hemodynamic measurements for determination of cardiac output, LV volumes, and ejection fraction by electromagnetic flowmeter and pressure-volume curves. LV wet weight was determined. In group A, MRI-acquired MI size (18.5 +/- 2%) was smaller than histology (22.8 +/- 2.5%, p < 0.05) with close correlation (r = 0.97). In group B, agreement in LV mass was found between MRI and wet weight (controls, 537.6 +/- 19.6 vs. 540.3 +/- 18.4 mg; MI, 865.1 +/- 39.2 vs. 865.1 +/- 41.3 mg; for the difference p = ns, r = 0.97, p < 0.05) and in the MRI and flowmeter measurements (cardiac output, controls 73.1 +/- 2.9 vs. 75.2 +/- 2.6 ml/min; MI 82.4 +/- 5.2 vs. 81.9 +/- 3.7 ml/min; for the difference p = ns, r = 0.80, p < 0.05). End-diastolic volume by MRI differed from pressure-volume curves with good correlation (controls, 343.9 +/- 8.4 vs. 262.7 +/- 12.8 microl; MI, 737.0 +/- 70.5 vs. 671.1 +/- 64.1 microl; p < 0.05 each, r = 0.96, p < 0.05). Cine-FLASH-MRI is a valuable diagnostic tool applicable to the rat model of MI. Being noninvasive and exact, it offers new insights in the remodeling process after MI because serial measurements are possible.

Animals↗

PubMed1999

Perfusion-corrected mapping of cardiac regional blood volume in rats in vivo.

Measurement of regional blood volume (RBV) in the myocardium in vivo is important for the assessment of tissue viability and function. The method in this work is based on the acquisition of a T(1) map before and after intravascular contrast agent application. It is known that this method is influenced by perfusion that causes an overestimation of RBV values. In order to solve this problem, the new method is proposed which acquires T(1) maps with slice selective inversion pulses. Due to blood flow nonexcited spins enter the detection slice, which leads to an acceleration of the relaxation time. A model that divides tissue into two compartments is adapted to slice selective inversion in order to derive a simple expression for perfusion-corrected RBV. The aim of the study is to demonstrate the feasibility and accuracy of this technique for quantification of RBV in rat myocardium in vivo. RBV maps were obtained for five rats, and the reproducibility was determined by repeating the experiment several times. A mean RBV value of 12.8 +/- 0.7% (v/v) over all animals was obtained in the myocardium. The results were compared with RBV maps obtained with perfusion-sensitive RBV imaging in the same five rats and with first-pass RBV studies. In order to demonstrate the strength of the new method the vasodilator adenosine was administered and alterations in microcirculation were imaged. Magn Reson Med 42:500-506, 1999.

Adenosine↗