[MR imaging of stereotactic thalamotomy using radiofrequency methods].
Sixty-eight stereotactic radiofrequency (rf) thalamic lesions in 57 patients with movement disorders were evaluated by magnetic resonance (MR) imaging. Postoperative periods ranged from 5 days to 4 years and 9 months. All 68 rf lesions were clearly detected on T2-weighted images (T2WI). Changes in signal intensity on T2WI were classified into five patterns, as follows: Pattern I: lesions with three concentric zones consisting of an inner hypointense, middle hyperintense and outer hypointense zone (31 lesions); Pattern II: lesions consisting of an inner hypointense and outer hyperintense zone (4 lesions); Pattern III: lesions consisting of an inner hyperintense and outer hypointense zone (27 lesion); Pattern IV: lesions of a hyperintense area alone (2 lesions); Pattern V: lesions of a hypointense area alone (4 lesions). The outer hypointense rim in Patterns I and III is thought to represent hemosiderin deposition. The abnormal signal intensity on T2WI caused by rf ranged from 2 to 12 mm in diameter, and lesions in the late phase were smaller than lesions in the early phase.
Matsumoto
S
S
Department of Radiology, Faculty of Medicine, Kyushu University.
Shima
F
F
Hasuo
K
K
Uchino
A
A
Mizushima
A
A
Furukawa
T
T
Matsuura
Y
Y
Gibo
M
M
Masuda
K
K
Fukui
M
M
D000293:Adolescent; D004564:Electrocoagulation / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000175:diagnosis / Q000601:surgery*; D010300:Parkinson Disease / Q000175:diagnosis / Q000601:surgery; D013238:Stereotaxic Techniques; D013788:Thalamus / Q000473:pathology* / Q000601:surgery*