title: Nonenhancing Leptomeningeal Metastases: Imaging Characteristics and Potential Causative Factors.
abstract: The diagnosis of leptomeningeal metastasis (LM) has increased in frequency, as new therapies have lengthened the survival of patients with cancer. Early diagnosis and intervention help improve quality of life and prevent further neurological deterioration in LM. The detection of LM is often established by magnetic resonance imaging examinations, cerebrospinal fluid analysis, or both. We present a series of cases where LM was identified on fluid-attenuated inversion recovery or T2-weighted image but was nonenhancing on the traditionally more sensitive postcontrast T1-weighted sequences. Nonenhancing LM is unusual and not yet fully understood but should be considered in the appropriate clinical context and may become more common with increased utilization of antiangiogenic therapies.
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Vaios
authors.initials: V
authors.lastname: Hatzoglou
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Sasan
authors.initials: S
authors.lastname: Karimi
authors.affiliation: Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Eli L
authors.initials: EL
authors.lastname: Diamond
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Lis
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: George
authors.initials: G
authors.lastname: Krol
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Andrei I
authors.initials: AI
authors.lastname: Holodny
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Young
keywords: brain neoplasms; imaging; meningeal neoplasms; nervous system neoplasms; techniques