We evaluated the role of myocardial delayed-enhancement(MDE)magnetic resonance imaging(MRI)for noninvasive detection of fibrosis in Arrhythmogenic right ventricular dysplasia/cardiomyopathy(ARVD/C). Arrhythmogenic right ventricular dysplasia/cardiomyopathy is characterized by fibro-fatty replacement of the right ventricle(RV)leading to arrhythmias and RV failure. Endomyocardial biopsy can demonstrate fibro-fatty replacement of the RV myocardium; however, the test is invasive and carries a risk of perforation. Thirty consecutive patients were prospectively evaluated for ARVD/C. Magnetic resonance imaging was performed on a 1.5-T scanner. Ten minutes after intravenous administration of 0.2 mmol/kg of gadodiamide,MDE-MRI was obtained. Diagnosis of ARVD/C was based upon the Task Force criteria and did not include MRI findings. Twelve(40%)of 30 patients met the Task Force criteria for ARVD/C. Eight(67%)of the 12 ARVD/C patients demonstrated increased signal on MDE-MRI in the RV compared with none(0%)of the 18 patients without ARVD/C(p< 0.001). Endomyocardial biopsy was performed in 9 of the 12 ARVD/C patients. Of the nine patients, four had fibro-fatty changes consistent with the diagnosis of ARVD/C. Each of these patients had increased RV signal on MDE-MRI. None of the patients without ARVD/C had any abnormalities either on histopathology or on MDE-MRI. Electrophysiologic testing revealed inducible sustained ventricular tachycardia(VT)in six of the eight ARVD/C patients with delayed enhancement, compared with none of the ARVD/C patients without delayed enhancement(p=0.01). Noninvasive detection of RV myocardial fibro-fatty changes in ARVD/C is possible by MDE-MRI. Magnetic resonance imaging findings had an excellent correlation with histopathology and predicted inducible VT on programmed electrical stimulation, suggesting a possible role in evaluation and diagnosis of patients with suspected ARVD/C.u001a Arrhythmogenic right ventricular dysplasia / cardiomyopathy is characterized by fibro-fatty replacement of (Arrhythmogenic the right ventricle (RV) leading to arrhythmias and RV failure. Endomyocardial biopsy can demonstrate fibro-fatty replacement of the RV myocardium; however, the test is invasive and carries a risk of perforation. Thirty consecutive patients were prospectively evaluated for ARVD / C. Magnetic resonance imaging was performed on a 1.5-T scanner. Ten minutes after intravenous administration of 0.2 mmol / kg of gadodiamide, MDE-MRI was obtained. Diagnosis of ARVD / C was based upon the Task Force criteria and did not include MRI findings. Eight (67%) of the 12 ARVD / C patients characterized increased signal on MDE-MRI in the RV compared wit Of the nine patients, four had fibro-fatty changes consistent with the diagnosis of hVd (0%) of the 18 patients without ARVD / C (p <0.001) None of the patients without ARVD / C had any abnormalities either on histopathology or on MDE-MRI. Electrophysiologic testing revealed inducible sustained ventricular tachycardia (VT) in six of The eight ARVD / C patients with delayed enhancement, compared with none of the ARVD / C patients without delayed enhancement (p = 0.01). Noninvasive detection of RV myocardial fibro-fatty changes in ARVD / C is possible by MDE-MRI. imaging findings had an excellent correlation with histopathology and predicted inducible VT on programmed electrical stimulation, suggesting a possible role in evaluation and diagnosis of patients with suspected ARVD / C. u001a