Investigation of energy weighting using an energy discriminating photon counting detector for breast CT

摘要: Purpose: Breast CT is an emerging imaging technique that can portray the breast in 3D and improve visualization of important diagnostic features. Early clinical studies have suggested has sufficient spatial contrast resolution for accurate detection masses microcalcifications breast, reducing structural overlap often a limiting factor reading mammographic images. For number reasons, image quality may be improved by use energy resolving photon counting detector. In this study, authors investigate improvements obtained when using weighting with detector as compared to conventional integrating detector. Methods: Using computer simulation, realistic images multiple phantoms were generated. The simulation modeled prototype system amorphous silicon (a-Si), CsI based different x-ray spectra, hypothetical, ideal CZT capability discrimination. Three biological signals interest spherical lesions inserted into phantoms; hydroxyapatite (HA) represent microcalcification, infiltrating ductal carcinoma (IDC), iodine enhanced (IIDC). Signal-to-noise ratio (SNR) these three was measured from reconstructions. addition, psychophysical study conducted evaluate observer performance detecting embedded anthropomorphic phantom. Results: range tested, SNR higher (than method) 30%–63% 4%–34%, HA IDC 12%–30% (with Al filtration) 32%–38% Ce IIDC lesion, respectively. average area under receiver operating characteristic curve (AUC) greater than 19% (for methods tested) AUC detector. Conclusions: This showed provide pixel SNR, detectability Since degrading physical factors not detector, improvement should considered upper bound on achievable performance.