Photograph of the microPET scanner designed at UCLA, Los Angeles, CA, USA. The scanner is capable of imaging small animals such as mice in 30-60 min with a spatial resolution of ~ 2 mm in each axis (8 mm3). The scanner uses an 8 × 8 array of 2 × 2 × 10 mm3 lutetium oxyorthosilicate crystals. The ring diameter is 17.1 cm. The transaxial and axial fields of view are 17.1 and 1.8 cm, respectively.