Faculty Bibliography

Women"™s engagement in medicine, and more specifically cardiovascular imaging and cardiovascular MRI (CMR), has undergone a slow evolution over the past several decades. As a result, an increasing number of women have joined the cardiovascular imaging community to contribute their expertise. This collaborative work summarizes the barriers that women in cardiovascular imaging have overcome over the past several years, the positive interventions that have been implemented to better support women in the field of CMR, and the challenges that still remain, with a special emphasis on women physicians.

Although PVCs commonly lead to degraded cine cardiac MRI (CMR), patients with PVCs may have relatively sharp cine images of both normal and ectopic beats ("double beats") when the rhythm during CMR is ventricular bigeminy, and only one beat of the pair is detected for gating. MRI methods for directly imaging premature ventricular contractions (PVCs) are not yet widely available. Localization of PVC site of origin with images may be helpful in planning ablations. The contraction pattern of the PVCs in bigeminy provides a "natural experiment" for investigating the potential utility of PVC imaging for localization. The purpose of this study was to evaluate the correlation of the visually assessed site of the initial contraction of the ectopic beats with the site of origin found by electroanatomic mapping. Images from 7 of 86 consecutive patients who underwent CMR prior to PVC ablation were found to include clear cine images of bigeminy. The visually apparent site of origin of the ectopic contraction was determined by three experienced, blinded CMR readers and correlated with each other, and with PVC site of origin determined by 3D electroanatomic mapping during catheter ablation. Blinded ascertainment of visually apparent initial contraction pattern for PVC localization was within 2 wall segments of PVC origin by 3D electroanatomic mapping 76% of the time. Our data from patients with PVCs with clear images of the ectopic beats when in bigeminy provide proof-of-concept that CMR ectopic beat contraction patterns analysis may provide a novel method for localizing PVC origin prior to ablation procedures. Direct imaging of PVCs with use of newer cardiac imaging methods, even without the presence of bigeminy, may thus provide valuable data for procedural planning.

BACKGROUND:Restrictive cardiomyopathy (RCM) places patients at high risk for adverse events. In this study, we aim to evaluate the association between left atrial function and time to adverse events such as all-cause mortality and cardiovascular hospitalizations related to RCM. MATERIAL AND METHODS/METHODS:In this single-center study, ninety-eight patients with a clinical diagnosis of RCM were recruited from our registry: 30 women (31%); age (mean ± standard deviation) 61 ± 13 years. These patients underwent cardiac magnetic resonance (CMR) imaging from May 2007 to September 2015. Left atrial (LA) function (reservoir, contractile, and conduit strain), LA diameter and area, and left ventricular function (global longitudinal strain, ejection fraction), and volume were quantified, and the presence of late gadolinium enhancement was visually assessed. The cutoff value of the LA reservoir strain was selected based on tertile. An adjusted Cox proportional regression analysis was used to assess time to adverse outcomes with a median follow up of 49 months. RESULTS:= 0.008). CONCLUSIONS:The decreased LA reservoir strain is independently associated with time to adverse events in patients with RCM.

The number of implanted devices such as orthopedic hardware and cardiac implantable devices continues to increase with an increase in the age of the patient population, as well as an increase in the number of indications for specific devices. Many patients with these devices have or will develop clinical conditions that are best depicted at MRI. However, implanted devices containing paramagnetic or ferromagnetic substances can cause significant artifact, which could limit the diagnostic capability of this modality. Performing imaging with MRI when an implant is present may be challenging, and there are numerous techniques the radiologist and technologist can use to help minimize artifacts related to implants. First, knowledge of the presence of an implant before patient arrival is critical to ensure safety of the patient when the device is subjected to a strong magnetic field. Once safety is ensured, the examination should be performed with the MRI system that is expected to provide the best image quality. The selection of the MRI system includes multiple considerations such as the effects of field strength and availability of specific sequences, which can reduce metal artifact. Appropriate patient positioning, attention to MRI parameters (including bandwidth, voxel size, and echo), and appropriate selection of sequences (those with less metal artifact and advanced metal reduction sequences) are critical to improve image quality. Patients with implants can be successfully imaged with MRI with appropriate planning and understanding of how to minimize artifacts. This improves image quality and the diagnostic confidence of the radiologist. ^©RSNA, 2021.

Background/UNASSIGNED:Over half of all cancer patients receive radiation therapy (RT). However, radiation exposure to the heart can cause cardiotoxicity. Nevertheless, there is a paucity of data on RT-induced cardiac damage, with limited understanding of safe regional RT doses, early detection, prevention and management. A common initial feature of cardiotoxicity is asymptomatic dysfunction, which if left untreated may progress to heart failure. The current paradigm for cardiotoxicity detection and management relies primarily upon assessment of ejection fraction (EF). However, cardiac injury can occur without a clear change in EF. Objectives/UNASSIGNED:To identify magnetic resonance imaging (MRI) markers of early RT-induced cardiac dysfunction. Methods/UNASSIGNED:We investigated the effect of RT on global and regional cardiac function and myocardial T1/T2 values at two timepoints post-RT using cardiac MRI in a rat model of localized cardiac RT. Rats who received image-guided whole-heart radiation of 24Gy were compared to sham-treated rats. Results/UNASSIGNED:The rats maintained normal global cardiac function post-RT. However, a deterioration in strain was particularly notable at 10-weeks post RT, and changes in circumferential strain were larger than changes in radial or longitudinal strain. Compared to sham, circumferential strain changes occurred at the basal, mid-ventricular and apical levels (p<0.05 for all at both 8-weeks and 10-weeks post-RT), most of the radial strain changes occurred at the mid-ventricular (p=0.044 at 8-weeks post-RT) and basal (p=0.018 at 10-weeks post-RT) levels, and most of the longitudinal strain changes occurred at the apical (p=0.002 at 8-weeks post-RT) and basal (p=0.035 at 10-weeks post-RT) levels. Regionally, lateral myocardial segments showed the greatest worsening in strain measurements, and histologic changes supported these findings. Despite worsened myocardial strain post-RT, myocardial tissue displacement measures were maintained, or even increased. T1/T2 measurements showed small non-significant changes post-RT compared to values in non-irradiated rats. Conclusions/UNASSIGNED:Our findings suggest MRI regional myocardial strain is a sensitive imaging biomarker for detecting RT-induced subclinical cardiac dysfunction prior to compromise of global cardiac function.

Cardiac magnetic resonance imaging (CMR) is considered the gold standard for measuring cardiac function. Further, in a single CMR exam, information about cardiac structure, tissue composition, and blood flow could be obtained. Nevertheless, CMR is underutilized due to long scanning times, the need for multiple breath-holds, use of a contrast agent, and relatively high cost. In this work, we propose a rapid, comprehensive, contrast-free CMR exam that does not require repeated breath-holds, based on recent developments in imaging sequences. Time-consuming conventional sequences have been replaced by advanced sequences in the proposed CMR exam. Specifically, conventional 2D cine and phase-contrast (PC) sequences have been replaced by optimized 3D-cine and 4D-flow sequences, respectively. Furthermore, conventional myocardial tagging has been replaced by fast strain-encoding (SENC) imaging. Finally, T1 and T2 mapping sequences are included in the proposed exam, which allows for myocardial tissue characterization. The proposed rapid exam has been tested in vivo. The proposed exam reduced the scan time from >1 hour with conventional sequences to <20 minutes. Corresponding cardiovascular measurements from the proposed rapid CMR exam showed good agreement with those from conventional sequences and showed that they can differentiate between healthy volunteers and patients. Compared to 2D cine imaging that requires 12-16 separate breath-holds, the implemented 3D-cine sequence allows for whole heart coverage in 1-2 breath-holds. The 4D-flow sequence allows for whole-chest coverage in less than 10 minutes. Finally, SENC imaging reduces scan time to only one slice per heartbeat. In conclusion, the proposed rapid, contrast-free, and comprehensive cardiovascular exam does not require repeated breath-holds or to be supervised by a cardiac imager. These improvements make it tolerable by patients and would help improve cost effectiveness of CMR and increase its adoption in clinical practice.