Magnetic resonance imaging is safe in patients with left bundle branch pacing.

BACKGROUND: The use of left bundle branch pacing (LBBP) has dramatically increased since it was first described in 2016, but to date there are no published data on the safety of performing magnetic resonance imaging (MRI) in these patients. METHODS: Patients with LBBP who underwent MRI between January 2016 and October 2022 were retrospectively studied in our clinical center, which has a special program for imaging patients with cardiac devices. All patients underwent close cardiac monitoring throughout the MRI scans. Occurrence of arrhythmias or other adverse effects during MRI were assessed. LBBP lead parameters immediately pre- and post-MRI and at an outpatient follow-up were compared. RESULTS: Fifteen patients with LBBP underwent a total of 19 MRI sessions during the study period. Lead parameters did not significantly change after the MRI or on follow-up, which took place at a median of 91 days after the MRI. No patient developed arrhythmias during the MRI sessions, and no adverse effects such as lead dislodgement were reported. CONCLUSION: Although larger studies are necessary to verify our findings, MRI in patients with LBBP appears safe based on this initial case series.

Cardiac Outpouchings: Practical Approach to Normal Variants and Pathologic Conditions at CT and MRI.

Numerous entities, both structural and pathologic, can manifest as a contrast material- or blood-filled cardiac outpouching at imaging. These outpouchings often resemble one another and are frequently unfamiliar to imagers and clinicians, creating uncertainty when detected. Furthermore, the diagnostic criteria for conditions such as hernia, aneurysm, pseudoaneurysm, and diverticulum have not been consistently applied in studies and reports cited in the literature describing these outpouchings, adding to the confusion among general and cardiothoracic imagers. Pouches and outpouchings are commonly found incidentally on thoracic and abdominal CT scans obtained for other reasons. Many pouches and outpouchings can be confidently diagnosed or ignored at routine imaging, whereas others may require further evaluation with electrocardiographically gated CT, cardiac MRI, or echocardiography for a more definitive diagnosis. It is easiest to group and diagnose these entities on the basis of their cardiac chamber location or their involvement with the interatrial and interventricular septa. Ancillary features, such as motion, morphology, neck and body size, presence or absence of thrombus, and late gadolinium enhancement characteristics, are important in reaching a correct diagnosis. The aim of this article is to provide a practical guide to pouches and outpouchings of the heart. Each entity is defined according to its cause, imaging characteristics, clinical significance, and relevant associated findings. Mimics of cardiac pouches and outpouchings such as the Bachmann bundle, atrial veins, and thebesian vessels also are briefly discussed. Quiz questions for this article are available in the supplemental material. ©RSNA, 2023.

Accuracy of stepping-table lower extremity MR angiography with dual-level bolus timing and separate calf acquisition: hybrid peripheral MR angiography.

PURPOSE: To retrospectively evaluate the accuracy of hybrid peripheral magnetic resonance (MR) angiography by using conventional digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS: This retrospective study protocol received approval from the Office of Sponsored Research at Northwestern University, which included review by the Office for the Protection of Research Subjects. Informed consent was waived for this HIPAA-compliant study. One hundred twenty-one consecutive patients (67 men: mean age, 66 years +/- 12 [standard deviation]; 54 women: mean age, 69 years +/- 14), who were referred for evaluation of peripheral vascular disease, underwent peripheral contrast material-enhanced MR angiography. By using a hybrid technique, two independent timing measurements were performed in the pelvis and calves followed by MR angiography of the calves and, subsequently, a pelvis-thigh stepping-table acquisition. Images were evaluated for extent of disease, on the basis of degree of stenosis; for venous contamination, on the basis of venous signal intensity; and for diagnostic quality, on the basis of diagnostic confidence of the observer. DSA correlation of the extent of vascular disease was available in 45 of these patients, which was used to evaluate the diagnostic power of the hybrid technique. RESULTS: For detection of stenosis greater than 50%, the hybrid technique had 95% sensitivity (P < .05), 95% specificity (P < .05), and 95% accuracy (P < .05). There was no significant venous contamination in any of the examinations performed with this technique. CONCLUSION: The hybrid peripheral MR angiography technique provides diagnostic-quality examinations and virtually eliminates venous contamination.