title: Contrast-enhanced MR imaging of metastatic brain tumor at 3 tesla: utility of T(1)-weighted SPACE compared with 2D spin echo and 3D gradient echo sequence.
abstract: We evaluated the newly developed whole-brain, isotropic, 3-dimensional turbo spin-echo imaging with variable flip angle echo train (SPACE) for contrast-enhanced T(1)-weighted imaging in detecting brain metastases at 3 tesla (T). Twenty-two patients with suspected brain metastases underwent postcontrast study with SPACE, magnetization-prepared rapid gradient-echo (MP-RAGE), and 2-dimensional T(1)-weighted spin echo (2D-SE) imaging at 3T. We quantitatively compared SPACE, MP-RAGE, and 2D-SE images by using signal-to-noise ratios (SNRs) for gray matter (GM) and white matter (WM) and contrast-to-noise ratios (CNRs) for GM-to-WM, lesion-to-GM, and lesion-to-WM. Two blinded radiologists evaluated the detection of brain metastases by segment-by-segment analysis and continuously-distributed test. The CNR between GM and WM was significantly higher on MP-RAGE images than on SPACE images (P<0.01). The CNRs for lesion-to-GM and lesion-to-WM were significantly higher on SPACE images than on MP-RAGE images (P<0.01). There was no significant difference in each sequence in detection of brain metastases by segment-by-segment analysis and the continuously-distributed test. However, in some cases, the lesions were easier to detect in SPACE images than in other sequences, and also the vascular signals, which sometimes mimic lesions in MP-RAGE and 2D-SE images, were suppressed in SPACE images. In detection of brain metastases at 3T magnetic resonance (MR) imaging, SPACE imaging may provide an effective, alternative approach to MP-RAGE imaging for 3D T(1)-weighted imaging.
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan. komada.tomoshiro@fmbox.nagoya-u.ac.jp
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Komada
authors.forename: Shinji
authors.initials: S
authors.lastname: Naganawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ogawa
authors.forename: Masaya
authors.initials: M
authors.lastname: Matsushima
authors.forename: Seiji
authors.initials: S
authors.lastname: Kubota
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kawai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukatsu
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ikeda
authors.forename: Minako
authors.initials: M
authors.lastname: Kawamura
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Sakurai
authors.forename: Katsuya
authors.initials: K
authors.lastname: Maruyama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D013997:Time Factors
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA