PET is the favored nuclear imaging technique because of the high sensitivity and resolution it provides, as well as the possibility for quantification of accumulated radioactivity. ⁴⁴Sc (T_1/2=3.97h, Eβ⁺=632keV) was recently proposed as a potentially interesting radionuclide for PET. The aim of this study was to investigate the image quality, which can be obtained with ⁴⁴Sc, and compare it with five other, frequently employed PET nuclides using Derenzo phantoms and a small-animal PET scanner. The radionuclides were produced at the medical cyclotron at CRS, ETH Zurich (¹¹C, ¹⁸F), at the Injector II research cyclotron at CRS, PSI (⁶⁴Cu, ⁸⁹Zr, ⁴⁴Sc), as well as via a generator system (⁶⁸Ga). Derenzo phantoms, containing solutions of each of these radionuclides, were scanned using a GE Healthcare eXplore VISTA small-animal PET scanner. The image resolution was determined for each nuclide by analysis of the intensity signal using the reconstructed PET data of a hole diameter of 1.3 mm. The image quality of ⁴⁴Sc was compared to five frequently-used PET radionuclides. In agreement with the positron range, an increasing relative resolution was determined in the sequence of ⁶⁸Ga < ⁴⁴Sc < ⁸⁹Zr < ¹¹C < ⁶⁴Cu < ¹⁸F. The performance of ⁴⁴Sc was in agreement with the theoretical expectations based on the energy of the emitted positrons.