title: Contrast-enhanced 3-dimensional SPACE versus MP-RAGE for the detection of brain metastases: considerations with a 32-channel head coil.
abstract: OBJECTIVE
  The aim of this study was to compare the detection of brain metastases at 3 T using a 32-channel head coil with 2 different 3-dimensional (3D) contrast-enhanced sequences, a T1-weighted fast spin-echo-based (SPACE; sampling perfection with application-optimized contrasts using different flip angle evolutions) sequence and a conventional magnetization-prepared rapid gradient-echo (MP-RAGE) sequence.
  
  
  METHODS
  Seventeen patients with 161 brain metastases were examined prospectively using both SPACE and MP-RAGE sequences on a 3-T magnetic resonance system. Eight healthy volunteers were similarly examined for determination of signal-to-noise ratio (SNR) values. Parameters were adjusted to equalize acquisition times between the sequences (3 minutes and 30 seconds). The order in which sequences were performed was randomized. Two blinded board-certified neuroradiologists evaluated the number of detectable metastatic lesions with each sequence relative to a criterion standard reading conducted at the Gamma Knife facility by a neuroradiologist with access to all clinical and imaging data.
  
  
  RESULTS
  In the volunteer assessment with SPACE and MP-RAGE, SNR (10.3 ± 0.8 vs 7.7 ± 0.7) and contrast-to-noise ratio (0.8 ± 0.2 vs 0.5 ± 0.1) were statistically significantly greater with the SPACE sequence (P < 0.05). Overall, lesion detection was markedly improved with the SPACE sequence (99.1% of lesions for reader 1 and 96.3% of lesions for reader 2) compared with the MP-RAGE sequence (73.6% of lesions for reader 1 and 68.5% of lesions for reader 2; P < 0.01).
  
  
  CONCLUSIONS
  A 3D T1-weighted fast spin echo sequence (SPACE) improves detection of metastatic lesions relative to 3D T1-weighted gradient-echo-based scan (MP-RAGE) imaging when implemented with a 32-channel head coil at identical scan acquisition times (3 minutes and 30 seconds).
authors.affiliation: Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany. miriam.reichert@medma.uni-heidelberg.de
authors.forename: Miriam
authors.initials: M
authors.lastname: Reichert
authors.forename: John N
authors.initials: JN
authors.lastname: Morelli
authors.forename: Val M
authors.initials: VM
authors.lastname: Runge
authors.forename: Ai
authors.initials: A
authors.lastname: Tao
authors.forename: Ruediger
authors.initials: R
authors.lastname: von Ritschl
authors.forename: Andreas
authors.initials: A
authors.lastname: von Ritschl
authors.forename: Abraham
authors.initials: A
authors.lastname: Padua
authors.forename: James E
authors.initials: JE
authors.lastname: Dix
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Marra
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schoenberg
authors.forename: Ulrike I
authors.initials: UI
authors.lastname: Attenberger
mesh_terms: D001932:Brain Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D003287:Contrast Media; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D059629:Signal-To-Noise Ratio
chemical_list: D003287:Contrast Media