title: Clinical applications of diffusion magnetic resonance imaging of the lumbar foraminal nerve root entrapment.
abstract: Diffusion-weighted imaging (DWI) can provide valuable structural information about tissues that may be useful for clinical applications in evaluating lumbar foraminal nerve root entrapment. Our purpose was to visualize the lumbar nerve root and to analyze its morphology, and to measure its apparent diffusion coefficient (ADC) in healthy volunteers and patients with lumbar foraminal stenosis using 1.5-T magnetic resonance imaging. Fourteen patients with lumbar foraminal stenosis and 14 healthy volunteers were studied. Regions of interest were placed at the fourth and fifth lumbar root at dorsal root ganglia and distal spinal nerves (at L4 and L5) and the first sacral root and distal spinal nerve (S1) on DWI to quantify mean ADC values. The anatomic parameters of the spinal nerve roots can also be determined by neurography. In patients, mean ADC values were significantly higher in entrapped roots and distal spinal nerve than in intact ones. Neurography also showed abnormalities such as nerve indentation, swelling and running transversely in their course through the foramen. In all patients, leg pain was ameliorated after selective decompression (n = 9) or nerve block (n = 5). We demonstrated the first use of DWI and neurography of human lumbar nerves to visualize and quantitatively evaluate lumbar nerve entrapment with foraminal stenosis. We believe that DWI is a potential tool for diagnosis of lumbar nerve entrapment.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. yawara_eguchi@yahoo.co.jp
authors.forename: Yawara
authors.initials: Y
authors.lastname: Eguchi
authors.forename: Seiji
authors.initials: S
authors.lastname: Ohtori
authors.forename: Masaomi
authors.initials: M
authors.lastname: Yamashita
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Munetaka
authors.initials: M
authors.lastname: Suzuki
authors.forename: Sumihisa
authors.initials: S
authors.lastname: Orita
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kamoda
authors.forename: Gen
authors.initials: G
authors.lastname: Arai
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyagi
authors.forename: Nobuyasu
authors.initials: N
authors.lastname: Ochiai
authors.forename: Shunji
authors.initials: S
authors.lastname: Kishida
authors.forename: Yoshitada
authors.initials: Y
authors.lastname: Masuda
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Ochi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kikawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Takaso
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Aoki
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Toyone
authors.forename: Takane
authors.initials: T
authors.lastname: Suzuki
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D019299:Decompression, Surgical; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000175:diagnosis* / Q000473:pathology* / Q000601:surgery; D013126:Spinal Nerve Roots / Q000473:pathology*; D016896:Treatment Outcome