This study involves the comparison of two image acquisition sequences, the spin-echo (SE) sequence and the fast-spin-echo (FSE) sequence, used in magnetic resonance imaging (MRI).  The conventional SE sequence acquires one line of k-space at a time while the FSE sequence can acquire N lines of k-space at a time. FSE scan times are therefore much faster, but the disadvantages include a lower signal-to-noise ratio and reduced accuracy.  The purpose of this study is to compare T₁, T₂, and r images calculated from both FSE and SE sequences and to determine if images from the FSE sequence can be corrected, if necessary.  The experiment was carried out by preparing a phantom of five test targets with T₁ and T₂ values similar to brain tissue imaged at 1.5T.  The phantom was imaged using a SE sequence and three different FSE sequences with N=8, 16, and 32.  The acquisition times were 90, 30, 15, and 5 minutes, respectively.  Fourteen images were acquired from each sequence and input into a computer program that generated T₁, T₂, and r images.  Two-dimensional T₂ vs. T₁ histograms were created and compared.  As N increased (and scan time decreased), the clusters in the two-dimensional histograms that represented the test targets became less clearly defined and their T₁ values increased.