This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bremerich, J. Articles by Saeed, M. Search for Related Content PubMed PubMed Citation Articles by Bremerich, J. Articles by Saeed, M.

CLINICAL STUDIES

Microvascular injury in reperfused infarcted myocardium: noninvasive assessment with contrast-enhanced echoplanar magnetic resonance imaging ¹

^a Department of Radiology, University of California San Francisco, San Francisco, California, USA

Manuscript received February 4, 1998; revised manuscript received May 11, 1998, accepted May 20, 1998.

Address for correspondence: Dr. Charles B. Higgins, Department of Radiology, MRI-Section, University of California San Francisco, 505 Parnassus Avenue, L308, San Francisco, California 94143-0628
Charles.Higgins{at}radiology.ucsf.edu

Objectives. The purpose of this study was to measure the accumulation of labeled albumin and to visualize its distribution pattern in reperfused infarcted myocardium as a function of time between onset of reperfusion and administration of the tracer.

Background. Myocardial microvascular injury leads to leakage of albumin from the intravascular space. Quantitative measurements of GdDTPA-albumin with inversion recovery echoplanar imaging (IR-EPI) may allow noninvasive monitoring of microvascular injury.

Methods. After 1 h of coronary artery occlusion, 56 rats were injected with GdDTPA-albumin or ¹²³I-GdDTPA-albumin either immediately before reperfusion or , 1 or 24 h after reperfusion. GdDTPA-albumin in blood, normal myocardium and reperfused infarction was dynamically measured with IR-EPI during 1 h postinjection (PI). Autoradiograms were obtained at 15 min PI. Accumulation of labeled albumin in myocardium was expressed as the ratio of myocardial to blood content.

Results. In normal myocardium, the ratio of changes of relaxation rate-ratio (R1-ratio) was 0.12 ± 0.01 and did not change over 1 h. In reperfused infarction, however, the R1-ratio increased after administration. Animals given GdDTPA-albumin before reperfusion exhibited fastest accumulation (R1-ratio 15 min PI: 0.56 ± 0.03) and essentially homogeneous distribution. The accumulation was slower when administered at , 1 and 24 h after reperfusion (R1-ratios 15 min PI: 0.39 ± 0.03; 0.31 ± 0.04; 0.16 ± 0.01; p < 0.001 compared to administration before reperfusion). Moreover, the tracer accumulated predominantly in the periphery of the injury zone.

Conclusions. Amount and distribution pattern of labeled albumin in reperfused infarction are modulated by duration of reperfusion. The accumulation of GdDTPA-albumin can be quantified by IR-EPI. Thus, IR-EPI may be useful to noninvasively monitor myocardial microvascular injury in reperfused infarction.

Abbreviations and Acronyms   ANOVA = analysis of variance   IR-EPI = inversion recovery echoplanar imaging   MRI = magnetic resonance imaging   R1 and T1 = longitudinal relaxation rate and time   TI = inversion time   TInull = inversion time with nil signal arising from tissue   TR and TE = repetition and echo times   TTC = triphenyltetrazolium chloride

This article has been cited by other articles:

				K. M. Marques, P. Knaapen, R. Boellaard, N. Westerhof, A. A. Lammertsma, C. A. Visser, and F. C. Visser Hyperaemic microvascular resistance is not increased in viable myocardium after chronic myocardial infarction Eur. Heart J., October 1, 2007; 28(19): 2320 - 2325. [Abstract] [Full Text] [PDF]

				M. Saeed, O. Weber, R. Lee, L. Do, A. Martin, D. Saloner, P. Ursell, P. Robert, C. Corot, and C. B. Higgins Discrimination of Myocardial Acute and Chronic (Scar) Infarctions on Delayed Contrast Enhanced Magnetic Resonance Imaging With Intravascular Magnetic Resonance Contrast Media J. Am. Coll. Cardiol., November 21, 2006; 48(10): 1961 - 1968. [Abstract] [Full Text] [PDF]

				G. A. Krombach, C. B. Higgins, M. Chujo, and M. Saeed Gadomer-enhanced MR Imaging in the Detection of Microvascular Obstruction: Alleviation with Nicorandil Therapy Radiology, August 1, 2005; 236(2): 510 - 518. [Abstract] [Full Text] [PDF]

				G. A. Krombach, M. F. Wendland, C. B. Higgins, and M. Saeed MR Imaging of Spatial Extent of Microvascular Injury in Reperfused Ischemically Injured Rat Myocardium: Value of Blood Pool Ultrasmall Superparamagnetic Particles of Iron Oxide Radiology, November 1, 2002; 225(2): 479 - 486. [Abstract] [Full Text] [PDF]

				T. Kudo, K. Fukuchi, A. J. Annala, A. F. Chatziioannou, V. Allada, M. Dahlbom, Y.-C. Tai, M. Inubushi, S.-C. Huang, S. R. Cherry, et al. Noninvasive Measurement of Myocardial Activity Concentrations and Perfusion Defect Sizes in Rats With a New Small-Animal Positron Emission Tomograph Circulation, July 2, 2002; 106(1): 118 - 123. [Abstract] [Full Text] [PDF]

				S. H. Rezkalla and R. A. Kloner No-Reflow Phenomenon Circulation, February 5, 2002; 105(5): 656 - 662. [Full Text] [PDF]

				M. Saeed, G. Lund, M. F. Wendland, J. Bremerich, H.-J. Weinmann, and C. B. Higgins Magnetic Resonance Characterization of the Peri-Infarction Zone of Reperfused Myocardial Infarction With Necrosis-Specific and Extracellular Nonspecific Contrast Media Circulation, February 13, 2001; 103(6): 871 - 876. [Abstract] [Full Text] [PDF]

				M. T. Roe, E. M. Ohman, A. C. P. Maas, R. H. Christenson, K. W. Mahaffey, C. B. Granger, R. A. Harrington, R. M. Califf, and M. W. Krucoff Shifting the open-artery hypothesis downstream: the quest for optimal reperfusion J. Am. Coll. Cardiol., January 1, 2001; 37(1): 9 - 18. [Abstract] [Full Text] [PDF]

				H. Bonnemeier, F. Hartmann, U. K. H. Wiegand, F. Bode, H. A. Katus, and G. Richardt Course and prognostic implications of QT interval and QT interval variability after primary coronary angioplasty in acute myocardial infarction J. Am. Coll. Cardiol., January 1, 2001; 37(1): 44 - 50. [Abstract] [Full Text] [PDF]

				H. Arheden, M. Saeed, C. B. Higgins, D.-W. Gao, P. C. Ursell, J. Bremerich, R. Wyttenbach, M. W. Dae, and M. F. Wendland Reperfused Rat Myocardium Subjected to Various Durations of Ischemia: Estimation of the Distribution Volume of Contrast Material with Echo-planar MR Imaging Radiology, May 1, 2000; 215(2): 520 - 528. [Abstract] [Full Text]

				M. Saeed, J. Bremerich, M. F. Wendland, R. Wyttenbach, H.-J. Weinmann, and C. B. Higgins Reperfused Myocardial Infarction as Seen with Use of Necrosis-specific versus Standard Extracellular MR Contrast Media in Rats Radiology, October 1, 1999; 213(1): 247 - 257. [Abstract] [Full Text]