 all these academic events. Thank you. So now we can move to the next talk for this session. And for this, I would like to invite our next speaker. So after all these important topics, we have yet another interesting and important topic on imaging the devices in C2. So imaging in CID is an update and we have with us Dr. Avanti. Dr. Avanti is a very young and dynamic radiologist. She has completed postdoctoral scholarship in radiology from University of Washington School of Medicine Seattle, USA, a clinical research fellowship in cardiovascular imaging at Perelman School of Advanced Medicine, University of Pennsylvania USA. And she is a certified level three fellow in cardiovascular imaging from the Society of Cardiovascular Magnetic Resonance US and has experience in CMR for CID patients. USM in myocardial re-perfusion imaging, CMR in electrophysiology, CMR on seven Tesla, CT derived FFR and TAVRs. Multiple publications to her credit to name a few in nature communications, radiology clinics of North America and current radiology reports. She is editor, her work has been recognized and received editor's recognition award and also distinguished research award by University of Pennsylvania recognized at annual pender grass conference June 2020. And also received young investigator award finalist. She was for NASCAR and AHA in cutting edge technology 2018 and 2020. So we look forward to your talk Dr. Avanti and from learning from you. Thank you for joining us and let's begin with the talk. Hello, I'm Avanti and I'm here to give you all an update on imaging and cardiac implantable electronic devices. I have no disclosures. The centers for Medicare and Medicaid services which administer the Medicare and Medicaid programs in the United States had recently provided coverage to many patients with devices that are non-MR conditional. This makes it very important to understand the concepts and guidelines for imaging patients with cardiac implantable electronic devices. These include cardiac pacemakers, implantable cardiobotardic accelerators, transvenous or subcutaneous, cardiac resynchronization therapy devices, implantable cardiac rhythm monitors, and neurostimulators. Recent estimates suggest that unmet imaging needs could apply to up to 1.4 million patients with implanted devices worldwide. Many vendors supply a variety of devices and you may be familiar with their needs such as send you medical, Boston scientific, metronic, etc. But the basic parts of the device remains the same. An implanted device has a pulse generator with a finite battery. Electrodes connected to the generator via a terminal connector pin which should be engaged and the distilled end of the electrode is composed of lead wires with different tips for attachment to the heart. The image shows the battery, the connector pin and the internal electrical circuitry of the device generator. Obtaining a test radiograph is the simplest way for looking at any implanted device for its type, anatomic location and positioning of leads. Right atrial lead is directed towards the right atrial appendage. Right ventricular lead reaches up to the apex. Left ventricular lead courses through the coronary sinus and ends in a posterior cardiac vein. Epicardial leads are positioned on ventricular surfaces for pacing during cardiac surgeries. Here is a radiograph showing a dual chamber pacemaker. Its generator is seen in the left intraclavicular fossa and it contains two lead wires that allow pacing of the right atrium and right ventricles simultaneously in order to coordinate their contractions. Right atrial lead is directed inferiorly and forming a J-loop. Right ventricular lead should be seen to the left of the spine on the test radiograph. Dual chamber pacemakers are used in patients with heart block or SNO disease or patients with atrial fibrillation with a slow ventricular response. Cardiac resynchronization therapy is used to treat refractory heart failure associated with ventricular dyssynchrony. These devices have one lead pacing each ventricle. The transvenous lead, LV lead, enters the right atrium through the coronary sinus orifice taking an endovenous up-and-time course until the tip reaches a left ventricular wall epicardial vein. This can be confirmed on a lateral view showing a posteriorly oriented lead. Biventricular pacing can also be achieved using epicardial lead sutured through a thoracotomy. Note the generator launched in the inferior left anterior chest wall. The right atrial lead is well positioned. Transvenous ICDs contain a lead with either one or two metal shock coils. Note the shock coil placed at the brachiocephalic vein and superior vena cava junction and a distilled shock coil in the right ventricular apex. Also note the difference in the thickness of the shock coil compared to the pacemaker lead. Transvenous ICDs are often combined with biventricular pacemakers to provide resynchronization therapy to high risk heart failure patients and these are called SCRT leads. Note the combination of the pacemaker leads and the shock coils in these radiographs. Note the tavern implant for aortic stenosis. In an effort to eliminate pacemaker wires, leadless cardiac pacemakers were recently introduced. They are similar to a triple A battery in size and shape and the implantation in the right ventricle involves only minimally invasive procedure. Subcutaneous ICD is a novel technology that does not require transvenous lead insertion for defibrillation. Instead a pulse generator placed in the lateral chest delivers a trans thoracic shock via a left parasternal subcutaneous lead containing sensing electrodes and shock coils. This device can be implanted in patients requiring defibrillation as long as they do not need pacing for tachycardia or radicardia. No recorders are implantable cardiac monitors to continuously record the cardiac rhythm in patients with unexplained palpitations and syncope. They are placed subcutaneously. These devices are actually getting smaller and smaller and should not be mistaken for a USB flash drive. Parkinson's brain stimulators have similar generators as cardiac pacemakers and are also placed in the subcutaneous chest these should not be confused with pacemakers. Inplantable cardioverter defibrillators differ from pacemakers with respect to MRI safety. Since they have increased ferromagnetic content and more conductive materials they are susceptible to higher translational forces and torque. Additional circuitry and hardware for cardioversion or defibrillation therapy increases the potential sources of unexpected behaviors such as device malfunction, unintended cardiac stimulation or electrical reset. It is wise to follow a checklist when reading chest radiographs of patients with devices and specifically look for the device type, the connector pin insertion, number and position of leads, lead integrity and also look for complications. For example in this 73 year old male with a single chamber pacemaker the lead is directed inferiorly through the right atrium and is taking a serpentine course to the coronary sinus. The lead tip is misplaced in an epicardial vein instead of the right ventricular apex. Lateral view confirms the lead misplacement with a lead curving in a loop and then coursing anteriorly instead of descending and coursing anteriorly as would be seen in a correctly positioned right ventricular lead. Another example of a misplaced right ventricular lead taking a swan-gan's neck course and ending in the left main pulmonary artery instead of the right ventricular apex. The right atrial lead is correctly placed in the right atrial appendage. Tink leads could lead to pacemaker malfunction. Complete lead fractures as seen as discontinuation of the lead wire proximal to the generator. The wide gap represents dislodgement and migration of the lead segments. Fidler syndrome occurs when the generators were predicted by a patient causing the lead wires to dislodge and wind around the generator. In this case the right atrial lead has been removed from the right atrial appendage and lies in the superior vena cava and the right ventricular lead now lies within the right atrium. Another example of lead wire being completely reeled around the generator causing the patient to receive no electrical therapy. Suspect abandoned leads. When multiple pacemaker leads are seen in the RA or RV, in this case the abandoned leads can ICD leads can be seen which aren't attached to any generator. This is an example here of epicardial leads from the abdomen. There are several indications for performing cardiac MR in patients with arrhythmias and devices. Petrogenous scar that forms arrhythmogenic substrate is precisely depicted on late gadolinium enhancement cardiac MR. Scar characterization helps in planning endocardial versus epicardial approach in patients with ventricular cardiac. Cardiac MR helps to diagnose premature ventricular complex induced cardiomyopathy. Identify electrical substrate in arrhythmic cardiomyopathy. 2D single shot and 3D volumetric LGE acquisition with navigator gating apart of protein CMR acquisitions for patients with arrhythmias. T1 mapping helps to identify diffuse myocardial fibrosis that may not be visible on late gadolinium enhancement CMR especially in patients of hypertrophic cardiomyopathy with ventricular tachycardia. A common atrial flutter passes through a narrow structure called as the cable tricuspid business and its ablation is used for termination of atrial strata. Cardiac MR can be used in planning pulmonary vein isolation in patients with atrial fibrillation. It involves circumferential ablation near the pulmonary vein osteum. In patients with atrial fibrillation, the results of the ongoing decaf2 trial are expected soon and they might extend the ablation strategies from pulmonary vein isolation alone to a substrate based approach. I showed in this image so once implanted with a device, patients who need CT or MR and the clinicians must deal with concerns related to safety of the procedure and the radiologist may face issues with imaging artifacts that appear due to in situ devices and can hamper radiologic assessment. Static and time varying magnetic field were proposed to cause displacement of the device, activation of the rib switch that can cause unintended cardiac stimulation, induce electrical currents that can generate induction voltage and cause premature battery depletion. RF pulse can cause heating of the ribs device free programming and alteration in piecing grids. This is how time varying magnetic gradients can lead to rib switch activation. Recent developments in the device engineering have led to devices whose operation is largely resilient to electromagnetic interference present in the MRI environment particularly at 1.5 Tesla. These advancements include reduction in the amount of ferromagnetic material, general robustness to electromagnetic interference, improvement in circuitry, sensing detecting detection algorithms. For example, rib switch is replaced by a Hall sensor with a more predictable behavior. With these developments in play and many studies such as the MagnaSafe registry demonstrating safety related to non-MR conditional devices, a comprehensive consensus report has been developed, detailing recommendations for CT and MRI in patients with cardiac implantable electronic devices. They are endorsed by several cardiologic and radiologic American societies for MRI. Potential temporary interactions are expected in patients who need CTs but only when the sensor circuits of the device are within the CTV. No device interrogation or programming or monitoring is recommended for class 1 indication but are reasonable but it is reasonable to exclude the device from field of view if images aren't going to be compromised. Radiologists should be aware of MR artifacts since scanning a patient with implanted device. The balance study state free precision sequence may be severely affected by susceptibility artifact. Late gadolinium enhancement PSIR image shows a characteristic artifact that appears as a central signal void and peripheral hyperintensity. Artifact is related to the type and proximity of the device. They are more prominent in ICDs than pacemakers due to a greater of resonance induced by the battery and high voltage transformer. Let us look at various several facets for implementing a program in radiology practice for MR imaging in patients with cardiac implantable electronic devices. The radiologist spearheading such a program would need to know new policies, device modes, new MRI sequences especially when obtaining a cardiac MR and what would be acceptable change to post MRI device parameters. MR conditional devices when a device is labeled MR conditional it means that such a device poses no known hazards within specified conditions of use. These conditions include a conditional labeling for combination of the generator and the units and allow implant locations. Also includes specified specific device programming requirements and availability of required staff trained staff or device programming and patient monitoring. A non MR conditional device in the system that has not met the regulatory criteria for MR conditional labeling. This could be pertaining to the entire device or only some of its components they are considered MR unsafe and have a older manufacturing day usually before the year 2000. These legacy devices are now considered a relative contraindication for MRI. For someone starting out the website MRICafety.com provides a comprehensive list of every device out there in the market with respect to their conditional or non conditional status. Another foolproof method is to ask for the device description from the vendors. In India it is very easy to get the firsthand information with vendors who are extremely proactive in just a phone call away. They also provide technicians for programming the device for a patient of schedule for an MR exam. According to the new US policies in US if a patient has a device labeled non conditional CMS will cover MRS scans done on scanner with a field strength of 1.5 tesla or less and the whole body specific absorption rate restricted to less than 2 watts per kg. Also the device should not have a fractured epicardial or abandoned use implantable cardiac rhythm monitors and neurostimulators are not included in the CMS coverage. Then there are simpler ways to ensure safety of a MRI procedure in patients with devices like obtaining the exam at least six weeks after the device implantation though not a guideline if the concern is movement of the generator or dislodgement of the need. Clinical exams do not result in damage to the heart tissue by defeating. Device interrogation and adequate programming should be performed before and after the MR exam and monitoring during the procedure. Now let us see one of the device modes. CID modes are labeled with three letters. First letter represents the chamber paste. Second letter represents the chamber sense. The third letter represents response to sensing. Letter A stands for atria, B for ventricle, D for dual, I for inhibit, D for trigger and over of. Decimode VOO stands for ventricle paste with sensing and triggering functions switched off. The programming differs for patients who are pacing dependent as they lack an underlying rhythm with heart rate 40 beats per minute or less or they have a complete heart block with no underlying rhythm. These patients are usually programmed to asynchronous pacing mode with triggering function of. If a patient is non-pacing dependent they are programmed to a monitor mode with dual chamber sensing only or in limited mode with dual chamber pacing and sensing with triggering function off. In this case pacing will occur only when a natural heart beat is not present. We have detailed in our publication how to plan an organized institutional workflow for MRI in CIDs. For each referral the radiologist in charge should confirm that MRI is the test of choice for that particular patient and ensure that a qualified physician or a PA is available during the scan. A test x-ray should be taken before the scan to look for device and lead positions. Establish whether the device is conditional or non-conditional. If a non-conditional device is present then restrict the exam to 1.5 tesla scanners and these SAR to less than 2 watts per kg. Ensure patient's safety by ruling out fractured epicardial or abandon use. Discuss the risk and benefits of the MR exam with the patient and obtain informed consent. Consent should include information about the new pulse sequences if you are going to acquire a cardiac MRI and record device parameters before and after the exam. These parameters include sensing, impedance, capture threshold and battery voltage for each lead. Also check the intrinsic heart rhythm and vitals and switch off therapies for ICDs. Then based on pacing dependency program your device to a synchronous pacing mode or a monitor or inhibit mode in non-conditional devices. Conditional devices can be programmed to a vendor-specified MRI mode. Avoid competitive pacing when a patient is pacing non-pacing dependent. Remember to monitor the vitals, maintain timely verbal contact during the entire exam and telemetry recording should be done by an ACLS train staff. Acquire CMR exam with specific pulse sequences that help to mitigate the imaging artifacts and after the exam reintegrate the device parameters, restore baseline settings and follow-up if required. New cardiac MR sequences adopt strategies to reduce artifacts and yield interpretable scans for CMR in patients with implanted devices. Acquire cine imaging with spoiled gradient echo, your shorter echo times and a wide-band 3.8 kHz adiabatic inversion pulse for late gadolinium-enhanced acquisitions, TIS count and even maps. Wide-band mitigates the expected resonance offset of the myocardium due to the device generator. This is an example of a spoiled GRE sequence for cine imaging that prevented susceptibility artifacts and allowed clear images. You can see that there is delayed septal contraction that could be consistent with the bundle branch block or also associated with the pacemaker function in this patient. This slide shows how a modified wide-band NGV PSIR sequence removes the generator-related artifacts from the scan plane. In the image view, mid-myocardial scar is clearly seen in the anterior LV wall in the patient with hypertrophic cardiomyopathy and in the image view, a transmural infar is seen in the LV apex. This is an example of a wide-band TI scout acquisition, a 2D wide-band LGV PSIR sequence showing an inferior RCA infar and in this image showing sub-epicardial enhancement in patient with sarcoidosis. The generator artifact appears as a signal void and pointed with these asterisks on the arrowhead. 3DLG PSIR sequence can suffer with extreme artifacts during the exam. A wide-band 3DLG PSIR with navigator grating is now available to tackle this issue. Example of artifact reduction by using modified wide-band T1 mapping sequence. In some cases, depending on the side of the generator, it may be difficult to completely remove device artifact. Repositioning of the patient arm to move the device generator away from the chest wall can be tried in these cases. Know about the limits of the acceptable device parameter change post MRI. Further follow-up or reference to a cardiologist is needed if a battery voltage loss is more than 0.04 volts. Remember, the 30, 40 and 50 percent rule was significant change in lead impedance, ventricular sensing amplitude and pacemaker capture threshold respectively. Also, record the ventricular and atrial-pacing thresholds changes in the pre and the R-wave amplitudes and if there was an electrical reset of the device during the scan. This paper by the Heart Rhythm Society I previously described also has a report template that you can adopt into your practice. It serves as a checklist and requires recording of the generator information, lead information, MR conditional status and there's a column for recording pre and post MRI device parameters. You can also refer to meditronicacademy.com website for initial training for setting up of MRI services in patients with devices and avail the opportunity to register your institution as an MRI center but specific to metronic devices. Now let us look at some interesting cases acquired at Penn. Wideband late gadolinium enhancement CMR acquired in this patient with a single chamber MR conditional leadless pacemaker had to identify a sub-epicardial algae. This was diagnosed with myocarditis. No significant changes occurred in the device parameters. Next, this patient has a MR non-conditional dual chamber pacemaker. Underventor cardiac MR, septal hypokinases can be seen. The body line myocardial septal thickening, both these findings were attributable to chronic ventricular pacing causing chronic pacing related cardiomyopathy. This patient implanted with the subcutaneous ICD and event cardiac MR. Again, modified by Bankel's sequence helped in clarifying lack of fibrosis in the lateral LB wall that appeared hyper intense on the regular PSIR sequence. The septal scarring present in this patient was in keeping with burnt out hypertrophic cardiomyopathy. CMR was acquired in this patient with abandoned epicardial leads. No significant changes in the device parameters were noted after the scan. CMR helped in diagnosis of cardiac amyloidosis with extensive subendocardial and sub epicardial enhancement. So what lies in the future? A very recently published paper in the Journal of American Medical Association Cardiology on MRI in 139 consecutive patients with abandoned leads showed no changes in battery voltage, power on resets, or even changes in the pacing rates. CMR images from this study showing non-schemic mid-myocardial scar and a transmural ischemic scar in patients with active abandoned leads. Another multi-center study on 1148 patients and patients with non-MR conditional devices showed no increased risk to patients provided recommended protocols were followed. This is being published in the European Heart Journal in the next few weeks. Both these studies provide great deal of confidence in MRI as a safe procedure in patients with abandoned and epicardial leads and could also further lead to changes in the US policy. Near future is looking at MR guided EP abolition in patients who may know more benefit from devices to terminate events and have recurrent shots. Real-time active tracking technologies can enable workflow that closely mimics conventional electron atomic mapping. CMR can be further processed in these patients to identify conducting channels and facilitate their application. To conclude, acquisition of interpretable studies with good quality can result in changes in treatment, intervention, changes in the prognosis, and potential cost savings for therapy and device patients. Reticence of physicians and institutions to scan patients with devices is related to unfamiliarity rather than concerns about the safety of this procedure. Implementing a robust imaging protocol in patients with devices is an urgent need and easily feasible. These are the suggested readings and our references. I would like to thank Dr Harold for his invaluable input in today's presentation. He is the chief of cardiothoracic imaging at University of Pennsylvania. You can write to him at harold.lib at penmedicine.upn.edu. You can also write to me at avanthi.gee at udav.edu avanthi.gunhane at penmedicine.upn.edu. You can follow me on Twitter at avanthi0609. And also please subscribe to our channel indianradiogist.com. Thank you so much for your attention. Thank you so much Dr Avanti for taking up a very important topic. It's an area where there's a lot for us to learn. So thank you so much for joining us. Now let's move on to our next lecture, the second last lecture for