We modified the Cartesian 3D-fast spoiled gradient-echo sequence with T1rho magnetization preparation for prospective acceleration of knee-joint mapping using optimized sampling patterns (SPs) and compressed sensing (CS) reconstructions. In this sequence, after each T1rho preparation module, several k-space lines are captured, partially filling the 3D k-space. However, the ordering of the k-space filling is very important to maintain consistent T1rho contrast and to obtain stable quantitative mapping. This is even more challenging when arbitrary SPs are used for accelerated MRI. We investigate different k-space ordering schemes considering optimized SPs and Poisson disk SPs in prospective 3D-T1rho acquisition with CS reconstructions.