Intracoronary Injection of Contrast Media Maps the Territory of the Coronary Artery: An MRI Technique for Assessing the Effects of Locally Delivered Angiogenic Therapies

Carlsson, Marcus; Saeed, Maythem

doi:10.1016/j.acra.2008.09.002

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Volume 15, Issue 11 , Pages 1354-1359, November 2008

Intracoronary Injection of Contrast Media Maps the Territory of the Coronary Artery:1

An MRI Technique for Assessing the Effects of Locally Delivered Angiogenic Therapies

Department of Radiology and Biomedical Imaging, University of California, San Francisco, 513 Parnassus Avenue, HSW 207B, San Francisco, CA 94134-0628

Received 27 August 2008; accepted 4 September 2008.

Rationale and Objectives

The effects of locally delivered angiogenic factors or stem cells on the coronary artery perfusion territory are not well defined. Therefore, the aim of this study was to determine the ability of the selective injection of magnetic resonance contrast media (MR-CM) to map and quantify the territories of the major coronary arteries.

Materials and Methods

Selective coronary catheterization (n = 16 pigs) was performed under x-ray and magnetic resonance imaging (MRI) fluoroscopy in an x-ray and magnetic resonance suite. Catheters were placed in the left anterior descending (LAD), circumflex, or right coronary artery. The coronary perfusion territories were mapped by the intracoronary injection of MR-CM using first-pass perfusion (FPP) and early contrast-enhanced (CE) MRI. Cine MRI was used to quantify left ventricular (LV) mass. In 12 animals, the LAD coronary artery was occluded by microspheres to create infarctions. Infarct size was measured on delayed enhanced (DE) MRI after the intravenous injection of MR-CM.

Results

X-ray and magnetic resonance fluoroscopy were successfully used to catheterize the coronary arteries. The perfusion territories of the coronary arteries were defined as hyperenhanced regions on FPP and CE MRI. The LAD coronary artery territory was 33.7 ± 2.2% of LV mass on FPP MRI and 33.0 ± 2.3% on CE MRI (P = .63). Bland-Altman analysis showed close agreement between the two methods (0.7 ± 5.0%). DE MRI demonstrated the infarcted myocardium as hyperenhanced subregions of the perfusion territory (7.5 ± 1.2% of LV mass).

Conclusions

Interventional cardiac x-ray and magnetic resonance fluoroscopy can be used to map and quantify the perfusion territory of each coronary artery. This experimental method can be used before and after the local delivery of angiogenic factors and stem cell therapy to determine their efficacy.

Key Words: Interventional MRI, cardiac MRI, myocardial infarction, coronary artery, local angiogenic therapy