Clinical applications of diffusion magnetic resonance imaging of the lumbar foraminal nerve root entrapment.
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.
Eguchi
Yawara
Y
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
Ohtori
Seiji
S
Yamashita
Masaomi
M
Yamauchi
Kazuyo
K
Suzuki
Munetaka
M
Orita
Sumihisa
S
Kamoda
Hiroto
H
Arai
Gen
G
Ishikawa
Tetsuhiro
T
Miyagi
Masayuki
M
Ochiai
Nobuyasu
N
Kishida
Shunji
S
Masuda
Yoshitada
Y
Ochi
Shigehiro
S
Kikawa
Takashi
T
Takaso
Masashi
M
Aoki
Yasuchika
Y
Toyone
Tomoaki
T
Suzuki
Takane
T
Takahashi
Kazuhisa
K
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