High resolution structural magnetic resonance imaging scans were performed on a 3T Trio MR scanner (Siemens, Erlangen, Germany). A three-dimensional Magnetization Prepared Rapid Acquisition Gradient Echo (MPRAGE) T1-weighted sequence was used to acquire sagittal images with parameters TR=1500ms, TE=2.83ms, FOV=256×256mm, matrix=256×256, slice thickness=1.0 mm without gap, 160 slices, 2 averages. Images were processed and analyzed with Statistical Parametric Mapping 5 (SPM5) (http://www.fil.ion.ucl.ac.uk/spm) consistent with our previously published methods (3). Four SNPs, spanning the 16,278 basepair VEGFA locus (average spacing is 2194 basepairs), with good coverage of the major haplotype block, were chosen using ABI SNPbrowser 3.5 software. Genotyping was done in duplicate with complete concordance.
