title: Magnetic Resonance Imaging Features of Solitary Hypothalamitis.
abstract: OBJECTIVE
  The study aimed to characterize magnetic resonance imaging (MRI) findings of solitary hypothalamitis and evaluate their clinical value in diagnosis.
  
  
  METHODS
  Magnetic resonance imaging scans, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and contrast-enhanced T1-weighted sequences, of 8 biopsy-proven hypothalamitis lesions were retrospectively analyzed along with MRI features including size, shape, signal intensity, enhancement pattern, correlation with adjacent tissues, and changes in infundibular stalk and sella turcica.
  
  
  RESULTS
  Of 8 patients, 5 were diagnosed with lymphoplasmacytic proliferative inflammation, 2 with Langerhans cell histocytosis, and 1 with Rosai-Dorfman disease. Solitary hypothalamitis predominantly demonstrated mild hypointensity/isointensity in T1WI and mild hyperintensity in T2-weighted imaging. In contrast-enhanced T1WI, all lesions showed heterogeneous but primarily peripheral enhancement patterns. Seven cases showed the polygon sign. In T1WI, the normal high signal intensity of neurohypophysis was absent from all patients, with no infundibular stalk thickening. Seven patients presented with optic chiasma edema, and 5 with edema-like changes along the optic tract (OTE), but most showed no visual impairment (n = 7).
  
  
  CONCLUSIONS
  Magnetic resonance imaging, particularly postcontrast MRI, is the optimal modality for assessment of hypothalamic lesions. Peripheral enhancement with polygon sign and optic tract or chiasm edema without visual impairment are highly suggestive of hypothalamitis.
authors.affiliation: From the Departments of *Radiology and †Endocrinology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Yue
authors.initials: Y
authors.lastname: Wu
authors.forename: Ying
authors.initials: Y
authors.lastname: Tang
authors.forename: Ran
authors.initials: R
authors.lastname: Tao
authors.forename: Hongying
authors.initials: H
authors.lastname: Ye
authors.forename: Zhenwei
authors.initials: Z
authors.lastname: Yao
mesh_terms: D000328:Adult; D003287:Contrast Media; D005260:Female; D006801:Humans; D007027:Hypothalamic Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D007031:Hypothalamus / Q000000981:diagnostic imaging* / Q000473:pathology; D007089:Image Enhancement / Q000379:methods; D007249:Inflammation / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D003287:Contrast Media