Susceptibility weighted imaging and MR angiography

Magnetic resonance angiography (MRA) has undergone tremendous development since its inception (Nayler et al., J Comput Assist Tomogr 10:715-722, 1986; Nishimura et al., IEEE Trans Med Imaging 5:140-151, 1986; Haacke and Lenz, AJR Am J Roentgenol 148:1251-1258, 1987). To image the vessels in the brain at high fields clinically, there is no longer the need to use contrast agents thanks to the increased signal-to-noise at 3 T and the rapid scanning that is possible. Conventional time-of-flight (Potchen et al., Magnetic Resonance Angiography: Concepts and Applications, St. Louis: Mosby:xiv, 650, 1993) with or without magnetization transfer contrast (MTC) can give excellent coverage with high-resolution images. Similarly, susceptibility weighted imaging (SWI) can be used to create venographic images of vessels as small as 200-300 Im (Reichenbach, Radiology 204:272-277, 1997; Haacke et al., Magn Reson Med 52(3):612-618, 2004). In this chapter, we discuss the potential to image both arteries and veins in an SWI single or multiecho time-of-flight (TOF)-like sequence.