Jason Peter Stockmann1, Gigi Galiana2, Leo Tam1, Terry Nixon3, Robert Todd Constable1,2
1Biomedical Engineering, Yale University, New Haven, CT, USA; 2Diagnostic Radiology, Yale University, New Haven, CT, USA; 3Diagnostic Radiology, Yale University, New Have, CT, USA
We show the first single-channel, axial-plane O-Space images made using a custom, actively-shielded 12-cm Z2 quadratic gradient insert on a Siemens 3T human scanner. Gradient calibration via field mapping is described. Eddy currents are measured using two different methods and are found in each case to be negligible. Image reconstruction is performed using the entire encoding matrix with the Kaczmarz algorithm (also known as the algebraic reconstruction technique). As compared with images acquired using radial k-space trajectories, O-Space images show comparable resolution but reduced artifact levels owing to the less coherent point spread function of the quadratic field's curvilinear frequency isocontours.