Peripheral nerve tractography in soft tissue tumors: a preliminary 3-tesla diffusion tensor magnetic resonance imaging study.

INTRODUCTION

This diffusion tensor magnetic resonance imaging (DTI) study aimed to clarify the relationship of peripheral nerves and soft tissue tumors (STTs) in 3D to optimize subsequent treatment.

METHODS

Twenty-six consecutive STT patients (histologically malignant, n=10; intermediate, n=3; and benign, n=13) underwent 3-Tesla MRI using an echoplanar DTI sequence. Deterministic tractography was performed. Fractional anisotropy (FA) values were measured within peritumoral and distant regions of interest.

RESULTS

Tractography depicted the 3D course of the sciatic (n=12), femoral (n=2), tibial (n=7), fibular (n=2), median (n=1), musculocutaneous (n=1), and ulnar (n=1) nerves in a regular (n=8 of 18, 44.4%) or thinned (n=7 of 18, 38.9%) fashion. The lowest peritumoral FA values, abrupt thinning, and/or complete discontinuity of trajectories were found in 2 cases with histologically proven tumoral nerve infiltration.

CONCLUSIONS

DTI clarifies the 3D topography between major peripheral nerves and STTs and may be helpful in the assessment of peripheral nerve infiltration by malignant tumors.