Fast image acquisition is commonly used in quantitative MRI after contrast preparation, such as turbo-filed-echo (TFE), balance steady-state-free-precession (bSSFP), and turbo-spin-echo (TSE). k-Space data acquired are filtered by a modulation transfer function (MTF), causing contrast loss and blurring. Here, we derived the analytical formulation of the corresponding point spread function (PSF) of Cartesian TFE, bSSFP and TSE with 180° refocusing. The contrast-to-noise ratio (CNR) is defined and maximized, providing an analytically optimized selection of TFE/TSE factors and flip angles. bSSFP serves high CNR, small FWHM and large TFE factors. Long TR and short TE are suggested for TFE studies.