Recommendations for Imaging Patients With Cardiac Implantable Electronic Devices (CIEDs).

Historically, the presence of cardiac implantable electronic devices (CIEDs), including pacemakers and implantable cardioverter defibrillators (ICDs), was widely considered an absolute contraindication to magnetic resonance imaging (MRI). The recent development of CIEDs with MR Conditional labeling, as well as encouraging results from retrospective studies and a prospective trial on the safety of MRI performed in patients with CIEDs without MR Conditional labeling, have led to a reevaluation of this practice. The purpose of this report is to provide a concise summary of recent developments, including practical guidelines that an institution could adopt for radiologists who choose to image patients with CIEDs that do not have MR Conditional labeling. This report was written on behalf of and approved by the International Society for Magnetic Resonance in Medicine (ISMRM) Safety Committee. LEVEL OF EVIDENCE: 3. TECHNICAL EFFICACY STAGE: 1.

Stratifying risk of biliary complications in adult living donor liver transplantation by magnetic resonance cholangiography.

BACKGROUND: Accurate preoperative assessment of biliary anatomy in live donor hepatectomy may be helpful to assess the suitability of a graft and to stratify risk of biliary complications. METHODS: A retrospective review of existing data among donor and recipients of 36 living donor transplants was performed to assess role of preoperative magnetic resonance cholangiography (MRC) for defining biliary anatomy and to stratify risk of biliary complications. RESULTS: Thirty-six living liver donors underwent MRC, and subsequently right lobectomy. Intraoperative cholangiography and biliary exploration revealed that 24 donors (66.6%) had conventional and 12 (33.3%) had aberrant biliary anatomy. Intraoperative cholangiography demonstrated a strong correlation with MRC (P=0.001) and intraoperative findings (P=0.001). MRC had specificity and positive predictive value of 100%. The risk of developing biliary complication was 5.9 times higher if the biliary anatomy was of any type other than A (P=0.03, CI 1.06-32.9) after controlling for donor age, recipient age, and type of anastomosis. CONCLUSION: MRC reliably identified variant biliary anatomy. The preoperative MRC demonstrated congruence with the intraoperative cholangiogram and with the intraoperative findings. MRC is helpful in predicting risk of biliary complications in recipients, and identifies donors who would otherwise be excluded intraoperatively by cholangiography, thus limiting the risk of an unnecessary operation.

Comprehensive adenosine stress perfusion MRI defines the etiology of chest pain in the emergency room: Comparison with nuclear stress test.

PURPOSE: To compare standard of care nuclear SPECT imaging with cardiac magnetic resonance imaging (MRI) for emergency room (ER) patients with chest pain and intermediate probability for coronary artery disease. MATERIALS AND METHODS: Thirty-one patients with chest pain, negative electrocardiogram (ECG), and negative cardiac enzymes who underwent cardiac single photon emission tomography (SPECT) within 24 h of ER admission were enrolled. Patients underwent a comprehensive cardiac MRI exam including gated cine imaging, adenosine stress and rest perfusion imaging and delayed enhancement imaging. Patients were followed for 14 +/- 4.7 months. RESULTS: Of 27 patients, 8 (30%) showed subendocardial hypoperfusion on MRI that was not detected on SPECT. These patients had a higher rate of diabetes (P = 0.01) and hypertension (P = 0.01) and a lower global myocardial perfusion reserve (P = 0.01) compared with patients with a normal cardiac MRI (n = 10). Patients with subendocardial hypoperfusion had more risk factors for cardiovascular disease (mean 4.4) compared with patients with a normal MRI (mean 2.5; P = 0.005). During the follow-up period, patients with subendocardial hypoperfusion on stress MRI were more likely to return to the ER with chest pain compared with patients who had a normal cardiac MRI (P = 0.02). Four patients did not finish the MR exam due to claustrophobia. CONCLUSION: In patients with chest pain, diabetes and hypertension, cardiac stress perfusion MRI identified diffuse subendocardial hypoperfusion defects in the ER setting not seen on cardiac SPECT, which is suspected to reflect microvascular disease.

Prevalence and pathophysiologic attributes of ventricular dyssynchrony in arrhythmogenic right ventricular dysplasia/cardiomyopathy.

OBJECTIVES: This study sought to investigate the prevalence and mechanisms underlying right ventricular (RV) dyssynchrony in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) using tissue Doppler echocardiography (TDE). BACKGROUND: An ARVD/C is characterized by fibrofatty replacement of RV myocardium and RV dilation. These pathologic changes may result in electromechanical dyssynchrony. METHODS: Echocardiography, both conventional and TDE, was performed in 52 ARVD/C patients fulfilling Task Force criteria and 25 control subjects. The RV end-diastolic and -systolic areas, right ventricular fractional area change (RVFAC), and left ventricular (LV) volumes and function were assessed. Mechanical synchrony was assessed by measuring differences in time-to-peak systolic velocity (T(SV)) between the RV free wall, ventricular septum, and LV lateral wall. An RV dyssynchrony was defined as the difference in T(SV) between the RV free wall and the ventricular septum, >2 SD above the mean value for control subjects. RESULTS: The mean difference in RV T(SV) was higher in ARVD/C compared with control subjects (55 +/- 34 ms vs. 26 +/- 15 ms, p < 0.001). Significant RV dyssynchrony was not noted in any of the control subjects. Based on a cutoff value of 56 ms, significant RV dyssynchrony was present in 26 ARVD/C patients (50%). Patients with RV dyssynchrony had a larger RV end-diastolic area (22 +/- 5 cm(2) vs. 19 +/- 4 cm(2), p = 0.02), and lower RVFAC (29 +/- 8% vs. 34 +/- 8%, p = 0.03) compared with ARVD/C patients without RV dyssynchrony. No differences in QRS duration, LV volumes, or function were present between the 2 groups. CONCLUSIONS: An RV dyssynchrony may occur in up to 50% of ARVD/C patients, and is associated with RV remodeling. This finding may have therapeutic and prognostic implications in ARVD/C.