The Effectiveness of 4D Image Acquisition and Post-processing With Vios Works

Traditional scanning and post-processing of 2D Cardiac Magnetic Resonance images (CMRI) is highly technical and time consuming, with many exams requiring one to two hours to complete. In addition, performance of 2D scans often requires expert technologists working closely with the clinician imaging expert. These factors limit the general clinical utility of current generation cardiac MRI.

In order to address these factors, many researchers began to explore the use of 4D image acquisition and post processing to shorten exam time. These researchers have documented success at these efforts but, to the best of the current investigators' knowledge, such advanced imaging acquisition and post-processing systems are not readily commercially available in the US.

Recently GE teamed with Vios-Works for MRI to provide a cloud-based visualization platform for 4D MRI that provides quantitative and structured reporting in the post processing environment that makes use of advance MR imaging acquisition techniques. The images can be accessed by the interpreter and reviewed and manipulated in order to assess cardiac function and flow retrospectively, which, prior to this innovation, only has been available for computed tomography (CT) generated images.

This investigative team hypothesizes that the use of 4D imaging will result in reduced time for acquisition (approximately 6 minutes as opposed to 1 hour), and improvement of diagnostic capability.

Images will be acquired using the current standard 2D acquisition protocol for routine clinical cardiac MRI. A repeat acquisition will be completed using the new protocol for 4D imaging acquisition. This will require that patient exams be extended in length by six minutes for those enrolled in the study. The investigators will evaluate the image quality of the two techniques and grade them according to a scale of 1 to 3 with 1 being excellent cardiac borders easily identified; 2 - acceptable: cardiac borders acceptably identified; and 3, non-diagnostic. The investigators will specifically focus on the evaluation of cardiac function of both right and left ventricular function as well as flow analysis of both the aortic and pulmonic valves.

For each method, technician time and MD time will be collected. The exam will go through post processing for standard 2D, following by the new 4D post processing technique. Time for post processing will be collected. All subjects who agree will receive both a 2D and a 4D MRI. The investigators will evaluate inter and intra reader reliability by having all readers read the first 15 exams, and then read them a second time after two weeks in a different order Readers showing variation in performance will be retrained on interpretation of 4D MRI before reading scans for the study.

Once readers have been trained, the study will require that all 2D and 4D exams be read by two readers. The exams will be assigned randomly to readers using the Biostatistician Office random assignment services.

Inclusion criteria

• 18 years of age or older
• with a valid prescription for Cardiac MRI for the following: Congenital heart disease/Shunts, Valvular heart disease, Pulmonary Hypertension, Aortic Disease, Hypertrophic Cardiomyopathy (HCM)
• receiving Standard of Care services at the MRI Center
• consent to participate in the 4D trial

Exclusion criteria

Patients with any of the following will be excluded:

• Pacemaker or ICD implanted
• ICDs implanted
• Temporary Pacemakers (e.g. transvenous temporary wires)
• Leads that are abandoned (capped or retained leads not attached to device)
• Non-transvenous leads (e.g. epicardial leads)
• Leads that have no fixation (e.g. floating leads)
• A lead that is known to be fractured
• Any other metallic objects that, in the opinion of the safety officer would compromise patient safety