Mitsue Miyazaki^1
1Toshiba Medical Research Institution, Vernon Hills, IL, United States

Both contrast enhanced (CE) and non-contrast enhanced (NCE) MRA techniques are introduced. In CE-MRA, developing trends including bolus timing estimation, temporal and spatial resolution improvement, and low dose gadolinium (Gd) MRA are revisited. In NCE-MRA, recent developments, including inflow, flow-dependent, and spin labeling techniques are introduced. Clinical applications of these NCE-MRA techniques are also demonstrated.

James Carr^1
1NORTHWESTERN

This presentation will demonstrate the technical and clinical applications of contrast enhanced and non-contrast magnetic resonance angiography (MRA). MRA is routinely used to evaluate the vasculature in a non–invasive fashion. Contrast enhanced MRA can be implemented as a conventional timed flow arrest protocol or as time resolved dynamic imaging.  The technical aspects of both of these approaches will be described in detail. Several different Gadolinium based contrast agents are routinely used for CEMRA including both extracellular and blood pool agents. Methods for optimal utilization of contrast agents for MRA will be described. Because of the risk of NSF with gadolinium use in patients with renal failure, there has been renewed interest in non contrast MRA techniques. Several of these NCMRA approaches will be discussed. Through a series of case presentations, this talk will attempt to illustrate the optimal use of all of these techniques in clinical practice. At the end of this lecture, attendees should understand the basic technical principles for CEMRA and NCMRA and will also be more familiar with the appropriate clinical indications for using these techniques.

Oliver Wieben^1
1Depts. of Medical Physics & Radiology, University of Wisconsin-Madison, Madison, WI, United States

Over the last decades, many methodological advances have been introduced to expand the capabilities of anatomical and functional MRA beyond the basic MR acquisition principles. These innovations provide new opportunities and challenges. Here we will review several key concepts with a special focus on their terminology, protocol choices available to the clinical and research user, and implications on the resulting images in the context of contrast-enhanced MRA and flow MRI.

Alex J Barker^1
1Radiology, Northwestern University, Chicago, IL, United States

MRA and phase contrast flow measurements involve the measurement of moving bodies, specifically blood (or in some cases CSF). Motion will produces artifact in MR images. While some of these artifacts are advantageous for the purpose of MRA (TOF) and flow images, unanticipated motion will degrade the quality of the exam. This educational section will discuss the practical considerations and challenges when protocolling MRA and flow measurements.

Winfried Willinek^1
1Department of Radiology, Neuroradiology, Sonography and Nuclear Medicine

Alejandro Roldan-Alzate

Conventional flow-sensitive magnetic resonance imaging (MRI) using two-dimensional (2D) slice selection, cardiac gating, and phase contrast (PC) velocity encoding in one direction is an excellent quantitative alternative to measure blood flow in different vascular territories.  Recent advances allow for the acquisition of MRI data sets with three-directional velocity encoding over a 3D volume throughout the cardiac cycle in clinically feasible scan times of 20 minutes and less. This presentation will discuss clinical applications of 2D and 4D flow MRI.