title: Optimal visualization of multiple brain metastases for gamma knife radiosurgery.
abstract: BACKGROUND
  Optimal management of metastatic brain disease requires precise detection and detailed characterization of all intracranial lesions.
  
  
  METHODS
  We analyzed an experience with 3200 brain MRI investigations performed at 1.5 T and 3.0 T for identification and/or evaluation of intracranial metastases. Usually axial T1- and T2-weighted images and contrast-enhanced T1-weighted images in axial and coronal and/or sagittal projections were obtained. Fluid-attenuated inversion recovery and diffusion-weighted imaging were sometimes used as well. Routinely, 0.2 mmol/kg of gadoteridol (ProHance®) was administered intravenously, but the dose was reduced to 0.1 mmol/kg in elderly patients or in patients with mild renal dysfunction.
  
  
  RESULTS
  Magnetic resonance imaging (MRI) provided excellent information on tumor location; interrelations with functionally important intracranial structures; type of growth; vascularity; recent, old or multiple hemorrhages within or in the vicinity of the mass; presence of peritumoral edema; necrotic changes; subarachnoid dissemination; meningeal carcinomatosis. However, without administration of gadoteridol or without contrast enhancement, small metastatic tumors could not be reliably distinguished from brain lacunes. Some metastases (malignant melanoma, thyroid cancer, endocrine carcinoma, small cell lung carcinoma) may demonstrate specific neuroimaging features. Non-metastatic -multiple brain lesions caused by vascular, inflammatory, demyelinative or lymphoproliferative diseases require a thorough differential diagnosis with metastatic brain tumors based not only on neuroimaging but on additional analysis of various clinical data.
  
  
  CONCLUSIONS
  Contemporary MRI techniques provide excellent options for detection, detailed characterization, and differential diagnosis of metastatic brain tumors, which is extremely important when choosing the optimal treatment strategy, particularly with Gamma Knife radiosurgery.
authors: Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. yono@nij.twmu.ac.jp
authors: Yuko
authors: Y
authors: Ono
authors: Kayoko
authors: K
authors: Abe
authors: Motohiro
authors: M
authors: Hayashi
authors: Mikhail F
authors: MF
authors: Chernov
authors: Yoshikazu
authors: Y
authors: Okada
authors: Shuji
authors: S
authors: Sakai
authors: Kintomo
authors: K
authors: Takakura
mesh_terms: D001921:Brain / Q000473:pathology* / Q000601:surgery; D001932:Brain Neoplasms / Q000175:diagnosis / Q000556:secondary / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies