title: Peripheral nerve perfusion by dynamic contrast-enhanced magnetic resonance imaging: demonstration of feasibility.
abstract: OBJECTIVE
  The aim of this study was to establish dynamic contrast-enhanced perfusion in peripheral nerves for determination of blood-nerve permeability (K) and nerve blood volume (NBV) in peripheral neuropathies as compared with healthy controls.
  
  
  METHODS
  The study was approved by the institutional ethics committee, and written informed consent was obtained from all participants. Forty-three controls (24 women, 19 men; age, 48.7 ± 17.5 years) and 59 patients with peripheral neuropathy (28 women, 31 men; age, 52.7 ± 12.4 years) were examined by a standard protocol including a T1-weighted dynamic contrast-enhanced sequence (time of repetition/time of echo, 4.91/1.64; 10 slices; resolution 0.8 × 0.6 × 3.0 mm3). Time - signal intensity analysis was performed by normalizing to pre-bolus arrival and calculating the mean contrast uptake (MCU) for each patient. Further analyses were performed by customized software to calculate K trans and NBV. Statistical analysis included 2-sided Student's t tests of controls versus patients, receiver operating characteristic analysis, and subgroup analysis of patients according to etiologies of neuropathy.
  
  
  RESULTS
  Time-signal intensity analysis showed significantly increased contrast uptake in patients as compared with controls (MCU, 1.29 ± 0.15 vs 1.18 ± 0.08; P < 0.001). This was caused mainly by an increase in K trans (0.046 ± 0.025 vs 0.026 ± 0.016 min(-1); P < 0.001) and less by an increase in NBV (3.9 ± 2.6 vs 3.0 ± 1.9 mL/100 mL; P = 0.12). This trend was true for all etiologies except entrapment neuropathies. Excluding these, receiver operating characteristic analysis found an area under the curve of 0.78 (95% confidence interval, 0.69-0.89) for MCU and 0.77 (95% confidence interval, 0.65-0.90) for K to discriminate neuropathy from control.
  
  
  CONCLUSIONS
  Dynamic contrast-enhanced perfusion is a feasible technique to assess K trans and NBV in peripheral nerves and may be used in future investigations on peripheral neuropathies.
authors.affiliation: From the *Department of Neuroradiology and †Section of Experimental Radiology, Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Bäumer
authors.forename: Maximilian
authors.initials: M
authors.lastname: Reimann
authors.forename: Clemens
authors.initials: C
authors.lastname: Decker
authors.forename: Alexander
authors.initials: A
authors.lastname: Radbruch
authors.forename: Martin
authors.initials: M
authors.lastname: Bendszus
authors.forename: Sabine
authors.initials: S
authors.lastname: Heiland
authors.forename: Mirko
authors.initials: M
authors.lastname: Pham
mesh_terms: D001783:Blood Flow Velocity; D001810:Blood Volume; D001811:Blood Volume Determination / Q000379:methods*; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000493:pharmacokinetics; D008875:Middle Aged; D008954:Models, Biological; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D010525:Peripheral Nerves / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D010523:Peripheral Nervous System Diseases / Q000473:pathology / Q000503:physiopathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine