Lale Umutlu MD, Abstract Co-Author: Consultant, Bayer AG

Stefan Maderwald MSc, Abstract Co-Author: Nothing to Disclose

Sonja Kinner MD, Abstract Co-Author: Nothing to Disclose

Susanne C. Ladd MD, Abstract Co-Author: Nothing to Disclose

Mark E. Ladd PhD, Abstract Co-Author: Nothing to Disclose

Thomas C. Lauenstein MD, Presenter: Nothing to Disclose

The aim of this study was to evaluate the feasibility of non-enhanced and contrast-enhanced (CE-) MRA of the abdominal vasculature at 7 Tesla field strength.

MR examinations were performed in 31 healthy volunteers on a 7T whole-body MR system (Magnetom 7T, Siemens Healthcare), utilizing a custom-built 8-channel transmit/receive radiofrequency (RF) body coil for image acquisition. After RF shimming and sequence modification, the following sequences were obtained: 1) 2D FLASH, 2) 3D FLASH, and 3) TOF-MRA. For dynamic imaging Gadobutrol (Gadovist®, Bayer Schering Pharma) was injected intravenously at a dosage of 0.1 mmol/kg body weight using an automated injector (EMPOWER MR®, EZEM) and 3 dynamic 3D FLASH sequences were obtained (arterial, portal-venous and venous phase). Qualitative analysis with regards to renal and hepatic vessel delineation was performed using a five-point-scale (5=excellent to 1=non diagnostic).

The inherently high signal intensity of the abdominal arterial vasculature in T1w imaging enabled a moderate to excellent vessel delineation in all non-enhanced sequences. Visual analysis revealed the diagnostic superiority of TOF MRA among the non-enhanced sequences (mean 4.7 in all vessel segments) and its diagnostic equivalence to contrast-enhanced MRA (mean 4.8). While non-enhanced 3D FLASH MRI showed moderate delineation of the hepatic (3.0) and renal (3.4) arteries and good conspicuity of the portal veins (3.7), venous vasculature showed only poor contrast (mean 1.9). 2D FLASH imaging revealed a moderate conspicuity of all assessed vessel segments with reasonable impairment due to signal variations associated with residual inhomogeneities of B1-shimming.

This pilot study demonstrates the feasibility of in vivo contrast-enhanced ultra-high-field MRA. Non-enhanced T1w imaging in general and especially TOF MRA appear to be promising techniques for good quality non-enhanced vasculature evaluation. This may be of high diagnostic interest in patients with renal insufficiency, considering the issue of Nephrogenic Systemic Fibrosis.

Non-enhanced T1w imaging, especially TOF MRA, appear to be promising techniques for assessment of vessel pathologies in patients with contraindications to the application of gadolinium.

Umutlu, L, Maderwald, S, Kinner, S, Ladd, S, Ladd, M, Lauenstein, T, 7 Tesla Abdominal Vessel Imaging: Do We Really Need Gadolinium?.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11012144.html