Industry engagement: Contrast free MR angiography
Angiography is a common medical imaging technique that is used to visualise organs and blood vessels of the body. In order to obtain best images, Gadolinium-based contrast agent is the most commonly used chemical to enhance the visualisation of the vessels. However, there has been recent evidence linking gadolinium with the serious systemic fibrosing disease Nephrogenic Systemic Fibrosis (NSF)1. NSF is a serious condition that involves the fibrosis of skin, joints, eyes and internal organs, of which most of NSF suffering patients will develop severe kidney failure2.
Currently, there is no known cure for Nephrogenic Systemic Fibrosis. Consequently, there has been a recent trend to develop alternative imaging agents for angiography methods.
Siemens A.G is a worldwide market leader in the production of Magnetic Resonance Imaging scanners for diagnostic imaging. Developers at Siemens Healthcare USA have been working on a new contrast free method for Magnetic Resonance based Angiography for 1.5Tesla MR scanners, the most common clinical field strength. The larger signal available at higher field strengths (>3 Tesla) should allow smaller arteries to be visualised, but the current Radio frequency pulses used in the technique resulted in incomplete suppression of the venous system (Figure 1.)
The Siemens Healthcare USA developers contacted Siemens Ltd Australia, who through their collaboration with National Imaging Facility (NIF) and Centre of Advanced Imaging (CAI, University of Queensland), had access to expertise on radio frequency pulse optimisation. The resultant optimised RF pulses resulted in complete venous suppression, see Figure 2.
The optimised RF pulses were implemented in a Siemens distributed Works in Progress package for clinical validation at Siemen’s worldwide clinical partners. Successful application of this new technique will lead to it being released as a commercial product in Siemens’ high field clinical scanners. Such a technique will:
i) allow the longitudinal scanning of monitoring of patients with severe renal function who are most at risk of developing Nephrogenic Systemic Fibrosis;
ii) reduce imaging costs; and,
iii) improved patient comfort.
1. Thomsen HS. (2009) Nephrogenic systemic fibrosis: history and epidemiology, Radiologic Clinics of North America. 47(5):827-31.
2. Bernstein EJ. (2012) Nephrogenic systemic fibrosis: A systemic fibrosing disease resulting from gadolinium exposure, Best Practice & Research Clinical Rheumatology. 26(4):489-503.
For more information regarding the project, and/or accessing the NIF-UQ node, please go to: http://www.anif.org.au/aboutnif/nodes/UQ-Node.html