Look for the nerves! MR neurography adds essential diagnostic value to routine MRI in pediatric practice: a pictorial overview.

PURPOSE: This study aimed to assess the feasibility of magnetic resonance (MR) neurography in children, and the potential roles of diffusion-weighted imaging (DWI) and fiber-tracking (FT) techniques.

METHODS

Five pediatric patients (age range: 6-12 years) underwent magnetic resonance imaging (MRI) for various clinical indications: neurogenic bladder (case 1); persistent hand pain following minor trauma (case 2); progressive atrophy of the lower left extremity muscles (case 3); bilateral hip pain (case 4); and palpable left supraclavicular mass (case 5). All studies were performed using a 1.5-T Avanto MRI scanner (Siemens, Erlangen, Germany). The protocol included 3D T2-weighted STIR and SPACE imaging, T1-weighted fat-saturation post-gadolinium imaging and diffusion tensor imaging (DTI) with tractography. ADC (N×10(-3) mm(2)/s) and FA values were calculated from regions of interest (ROIs) centered on the nerves. Nerve-fiber tracks were calculated using a fourth-order Runge-Kutta algorithm (NeuroD software).

RESULTS

MR neurography allowed satisfactory visualization of all neural structures, and FA and ADC measurements were feasible. The final diagnoses were Tarlov cysts, median-nerve compression, sciatic perineurioma, Charcot-Marie-Tooth disease and plexiform neurofibroma in a patient with NF-1.

DISCUSSION: FA and ADC measurements are of little value because of the lack of normal reference values. Nerve-fiber tractography (FT) may be of value in the characterization of tumor pathology, and is also helpful in the planning of surgical treatments.

CONCLUSION

MR neurography is feasible in pediatric patients. However, a considerable amount of work has yet to be done to establish its role in the clinical management of the wide range of peripheral nerve diseases.