A new design that takes advantage of an asymmetric geometry was proposed to improve the resolution of PET imaging. The design employs two sets of detectors with different resolutions. The high resolution detectors are placed near the object being imaged and the lower resolution detectors placed far away from the object. This geometry produces a magnified projection of the PET radioisotope distribution onto the detectors far away, allowing one to resolve structures smaller than the intrinsic resolution of the larger detectors. A detector insert based on this new geometry is proposed to allow coincidence between the insert and an existing PET scanner. The device will allow a clinical PET scanner to zoom-in to the regions of interest with improved image resolution. Preliminary data demonstrated significant improvement in image resolution with the new design. Individual components of the proposed device need to be optimized to achieve good sensitivity to support the improved resolution.