Timothy Garcia PhD, Abstract Co-Author: Employee, Gamma Medica, Inc

Aleksandr Kivenson PhD, Presenter: Employee, Gamma Medica, Inc

Bryan Simrak, Abstract Co-Author: Employee, Gamma Medica, Inc

Haris Kudrolli PhD, Abstract Co-Author: Employee, Gamma Medica, Inc

Molecular Breast Imaging (MBI) systems fabricated using direct-conversion detectors have demonstrated very high sensitivity and specificity in detecting breast cancer in dense breasted women. These systems are made possible by the development of Cadmium Zinc Telluride (CZT) detectors, which combined with high-end application specific integrated circuit electronics make superior gamma imaging detectors. The quality of the CZT modules directly impacts image quality and patient scan time. This work seeks to correlate the improvements in MBI image quality to the improvements in CZT detector properties.

Performance data from CZT modules such as energy resolution, detector uniformity and photo-peak efficiency were analyzed. Energy calibration was performed by irradiating single CZT modules with 241Am and 57Co. Full gamma cameras were created by tiling the CZT modules into rectangular grids. The cameras were coupled to a registered tungsten collimator. Specialized phantoms designed to characterize image uniformity and lesion detectability were fabricated. The phantoms were filled with 99mTc (Sodium Pertechnetate) and data sets with event statistics representative of clinical data were acquired. 

Data was analyzed for 1,500 CZT modules fabricated from 2009 to the present. Both the absolute value and the variance of the detector parameters improved. This means that the detectors are higher-quality and more uniform, perhaps due to a more tightly controlled fabrication process. Cameras that were fabricated with CZT modules that were more uniform in their properties showed a corresponding improvement in image uniformity and signal-to-noise ratio of the lesions in the phantoms. 

This work has shown that an increase in CZT module performance directly corresponds to a higher-quality MBI image. In this presentation, we will present data from a number of cameras that shows the improvement over time and discuss the expected trend in future camera performance.

Improving detector quality resultings in both an improved MBI image quality, as well as reduced patient dose.

Garcia, T, Kivenson, A, Simrak, B, Kudrolli, H, Improvements in Commercial CdZnTe Detector Quality and Their Impact on Molecular Breast Imaging.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015094.html