Gregor Kasprian MD, Presenter: Nothing to Disclose

Hieronymus Engel, Abstract Co-Author: Nothing to Disclose

Peter Christian Brugger MD, PhD, Abstract Co-Author: Nothing to Disclose

Thomas Sycha, Abstract Co-Author: Nothing to Disclose

Oskar Aszmann, Abstract Co-Author: Nothing to Disclose

Christian Nasel MD, PhD, Abstract Co-Author: Nothing to Disclose

Fritz Stuhr RT, Abstract Co-Author: Nothing to Disclose

Franz M. Kainberger MD, Abstract Co-Author: Nothing to Disclose

Daniela Prayer, Abstract Co-Author: Nothing to Disclose

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

This study aims to assess advanced 3T MR imaging methods (diffusion tensor imaging – DTI, tractography and chemical shift imaging) in the visualization and characterization of upper extremity nerve (UEN) anatomy and pathology.

13 patients with clinically and electrophysiologically localized UEN lesions (cubital tunnel syndrome (CUS) n=6, carpal tunnel syndrome (CTS) n=4, radial nerve palsy (RNP) n=1, brachial plexus neurofibroma n=1 and lower brachial plexus palsy n=1) and 6 normal controls were imaged using a 3T MR and an axial echo-planar single shot DT weighted sequence (b=0/700, FOV(mm)=160x160x112, matrix 64x64, 16/32 diffusion encoding directions) coregistered with STIR and T2-weighted (slice thickness 2.5mm) sequences. Tractography of UEN was performed using the FACT algorithm and a multiple regions of interest approach. FA and ADC values of the calculated trajectories and at the cross sectional area of UEN were measured. Additionally chemical shift sensitive in- and opposed phase sequences were acquired.

Compared to normal controls, in all cases of CUS the ulnar nerve showed a reduction or complete disruption of trajectories proximally to the sulcus, mirrored by reduced FA values (0.274 vs 0.491 in normal controls) and a mean signal drop of over 50% (vs 62% in controls and 87% of median nerve signals) between in- and opposed phase sequences in the affected region. Disruption of trajectories in RNP was found several centimeters proximally to a traumatic nerve neuroma. By 3D visualization of the brachial plexus nerve roots and the topographical relation to a schwannoma, tractography was helpful in preoperative surgical planning.

3 Tesla DTI allows microstructural characterization of 3D anatomy and pathology of UEN. Chemical shift sensitive sequences can identify chronic ulnar nerve lesions in CUS.

Modern 3T imaging techniques have the potential to assess the structure and function of peripheral nerves and may add valuable information to the treatment of various peripheral nerve pathologies.

Kasprian, G, Engel, H, Brugger, P, Sycha, T, Aszmann, O, Nasel, C, Stuhr, F, Kainberger, F, Prayer, D, et al, 0, Advanced 3T MRI of Upper Extremity Nerves.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8016013.html