Gregor Kasprian MD, Presenter: Nothing to Disclose

Gabriele Amann MD, Abstract Co-Author: Nothing to Disclose

Joannis Panotopoulos MD, Abstract Co-Author: Nothing to Disclose

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

Daniela Prayer, Abstract Co-Author: Nothing to Disclose

Iris M. Noebauer MD, Abstract Co-Author: Nothing to Disclose

This 3 Tesla diffusion tensor MR imaging (DTI) study aims to identify and visualize, in 3D, peripheral nerve involvement in benign tumors or infiltration by malignant soft-tissue tumors (STT).

There were 27 patients (16 female, 11 male: mean age 54.9years) with suspected STT (histology available in 24 cases: sarcoma n=13, peripheral nerve sheet tumor n=4, lipoma and fibroma n=2, myxoma=2, other benign tumors n=3) who were examined using a 3T MR unit and an echoplanar DTI sequence (b-value of 700s/mm², 16 gradient encoding directions, voxel size 1.8mmx1.8mmx4mm and/or 1.2mmx1.2mmx3.5mm) in addition to the standard diagnostic protocol. The Philips Achieva(release 2.1.1.0) software was used to define multiple region of interest (ROI) along major and potentially affected peripheral nerves and tractography was performed (FA threshold: 0.15: maximum angle change 27°). Fractional anisotropy (FA) values were measured within lesional and non-lesional ROIs.

Tractography successfully depicted the 3D course of the sciatic (n=12), femoral (n=4), tibial (n=7), peroneal (n=2), median, and musculocutaneous (n=2) nerves. In 18 cases showing an immediate anatomical relationship with the STT, the nerves appeared continuous (n=9) or partially discontinuous (n=6). In 2/3 cases with complete nerve discontinuity, nerve infiltration was histologically proven. In 3 cases of peripheral nerve sheet tumors, the fascicular organization identified by DTI showed a good surgical correlation. A tendency toward lower lesional FA values was found in cases of sarcomas (.320 vs .390, p=.09).

3 Tesla DTI helps to clarify the 3D topographic relationship between major peripheral nerves and STT of the upper and lower extremities. Complete discontinuity at tractography and reduced regional nerve FA values may indicate nerve infiltration by malignant tumors.

DTI helps to optimize surgical procedure because of the preoperative 3D visualization and characterization of peripheral nerve involvement in benign and malignant STT.

Kasprian, G, Amann, G, Panotopoulos, J, Kainberger, F, Prayer, D, Noebauer, I, 3 Tesla Diffusion Tensor Peripheral Nerve Imaging in Soft Tissue Tumors.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9012547.html