Anatomic MR imaging and functional diffusion tensor imaging of peripheral nerve tumors and tumorlike conditions

• Published in: American journal of neuroradiology : AJNR 2013-04, Vol.34 (4), p.802-807
• Main Authors: Chhabra, A, Thakkar, R S, Andreisek, G, Chalian, M, Belzberg, A J, Blakeley, J, Hoke, A, Thawait, G K, Eng, J, Carrino, J A
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Charcot-Marie-Tooth Disease - pathology; Child; Diffusion Tensor Imaging - methods; Diffusion Tensor Imaging - standards; Diffusion Tensor Imaging - statistics & numerical data; Editor's Choice; Female; Follow-Up Studies; Functional; Humans; Lymphoma - pathology; Magnetic Resonance Imaging - methods; Magnetic Resonance Imaging - standards; Magnetic Resonance Imaging - statistics & numerical data; Male; Middle Aged; Neoplasms - pathology; Nerve Sheath Neoplasms - pathology; Neurilemmoma - pathology; Neurofibromatosis 1 - pathology; Observer Variation; Peripheral Nervous System Neoplasms - pathology; Young Adult
• ISSN: 0195-6108; 1936-959X
• DOI: 10.3174/ajnr.A3316

A number of benign and malignant peripheral nerve tumor and tumorlike conditions produce similar imaging features on conventional anatomic MR imaging. Functional MR imaging using DTI can increment the diagnostic performance in differentiation of these lesions. Our aim was to evaluate the role of 3T anatomic MR imaging and DTI in the characterization of peripheral nerve tumor and tumorlike conditions. Twenty-nine patients (13 men, 16 women; mean age, 41±18 years; range, 11-83 years) with a nerve tumor or tumorlike condition (25 benign, 5 malignant) underwent 3T MR imaging by using anatomic (n=29), functional diffusion, DWI (n=21), and DTI (n=24) techniques. Images were evaluated for image quality (3-point scale), ADC of the lesion, tractography, and fractional anisotropy of nerves with interobserver reliability in ADC and FA measurements. No significant differences were observed in age (benign, 40±18 versus malignant, 45±19 years) and sex (benign, male/female=12:12 versus malignant, male/female=3:2) (P>.05). All anatomic (29/29, 100%) MR imaging studies received "good" quality; 20/21 (95%) DWI and 21/24 (79%) DTI studies received "good" quality. ADC of benign lesions (1.848±0.40×10(-3) mm2/s) differed from that of malignant lesions (0.900±0.25×10(-3) mm2/s, P.05). FA of involved nerves was lower than that in contralateral healthy nerves (P.05), with excellent intermethod reliability (ICC=0.943 [95% CI, 0.836-0.980]). Tractography differences were observed in benign and malignant lesions. 3T MR imaging and DTI are valuable methods for anatomic and functional evaluation of peripheral nerve lesions with excellent interobserver reliability. While tractography and low FA provide insight into neural integrity, low diffusivity values indicate malignancy in neural masses.