PT  - JOURNAL ARTICLE
AU  - Chuanyong Bai
AU  - Richard Conwell
AU  - Hetal Babla
AU  - Joel Kindem
TI  - Improving image resolution using oversampling for pixelated solid-state Gamma cameras
DP  - 2011 May 01
TA  - Journal of Nuclear Medicine
PG  - 489--489
VI  - 52
IP  - supplement 1
4099  - http://jnm.snmjournals.org/content/52/supplement_1/489.short
4100  - http://jnm.snmjournals.org/content/52/supplement_1/489.full
SO  - J Nucl Med2011 May 01; 52
AB  - 489 Objectives For pixelated solid-state Gamma cameras, the physical size of the pixel is predefined during manufacturing. It limits the minimal pixel size that can be used for imaging and hence the spatial resolution of the acquired images. Methods We image a bar phantom on a pixelated solid-state camera with 120x96 3.25 mm pixels. In addition to the first image, we take three more images (oversampling) by moving the camera relative to the object in the camera plane to three different positions, i.e., (1) 0.5 pixel right, (2) 0.5 pixel down, and (3) 0.5 pixel right and 0.5 pixel down. The obtained images are in 128x128 matrix with 3.25 mm imaging pixel size. After the acquisition, the data are rebinned to 256x256 matrix with 1.625 mm pixel size. Using the four rebinned images, an iterative algorithm is developed to compute the final image that is also in 256x256 matrix with 1.625 pixel size. The iterative images are then compared with the images obtained using an interleaving approach that has been shown to improve image quality for pixelated cameras. Using the interleaving approach, the three oversampling images are added to the first image according to the move of the detector during the acquisition. Results The bar phantom had four sets of bars with spacing 3.5 mm, 3.0 mm, 2.5 mm, and 2.0 mm. None of the four images could resolve any of the bar sets individually. But the interleaved images from the four images cleared resolved the 3.5 mm and 3.0 mm bar sets and marginally resolved the 2.5 mm set. The iterative approach showed significantly improved performance over the interleaving approach. The iterative images resolved the 3.5 mm and 3.0 mm bar sets with significantly improved contrast over the interleaved images. The iterative images also clearly resolved the 2.5 mm set and marginally resolved the 2.0 mm set. Conclusions We developed an oversampling scheme and an iterative approach to use the oversampling data to reduce the effective imaging pixel size and improve the image resolution by a factor of two for imaging with pixelated Gamma cameras