Peripheral nerve tractography in soft tissue tumors: A preliminary 3‐tesla diffusion tensor magnetic resonance imaging study

: 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. Muscle Nerve 51: 338–345, 2015