Effect of soft-copy display supported by CAD on mammography screening performance.

Contains fulltext : 50237.pdf (publisher's version ) (Closed access)Diagnostic performance and reading speed for conventional mammography film reading is compared to reading digitized mammograms on a dedicated workstation. A series of mammograms judged negative at screening and corresponding priors were collected. Half were diagnosed as cancer at the next screening, or earlier for interval cancers. The others were normal. Original films were read by fifteen experienced screening radiologists. The readers annotated potential abnormalities and estimated their likelihood of malignancy. More than 1 year later, five radiologists reread a subset of 271 cases (88 cancer cases having visible signs in retrospect and 183 normals) on a mammography workstation after film digitization. Markers from a computer-aided detection (CAD) system for microcalcifications were available to the readers. Performance was evaluated by comparison of A(z)-scores based on ROC and multiple-Reader multiple-case (MRMC) analysis, and localized receiver operating characteristic (LROC) analysis for the 271 cases. Reading speed was also determined. No significant difference in diagnostic performance was observed between conventional and soft-copy reading. Average A(z)-scores were 0.83 and 0.84 respectively. Soft-copy reading was only slightly slower than conventional reading. Using a mammography workstation including CAD for detection of microcalcifications, soft-copy reading is possible without loss of quality or efficiency

Mathematical Methods in Medical Imaging: Analysis of Vascular Structures for Liver Surgery Planning

this paper is to discuss digital image processing methods to analyze the patient's intrahepatic vessel structure and to determine the individual localization and extension of the liver segments from clinical CT or MR volume data. Such a volume is denoted by a matrix

An expanded de Wijs model for multifractal analysis of mineral production data

Hydrothermal ore deposits form by enriching elements and minerals from background values to very high concentrations in small volumes of the crust. The de Wijs model provides a simple and widely used mathematical description of this process; however, it does not account for the increase in density which generally attends the formation of high specific gravity minerals in many mineral deposits. We present an expanded version of the de Wijs model to investigate the distribution of ore tonnage as well as grade. The expanded model generates a log–normal relationship between ore tonnage and grade. Continuous\ud multifractal analysis of results from the new model using\ud the method of moments technique predicts that ore grades\ud are multifractal (as in the original de Wijs model) but that\ud ore tonnage values are not multifractal. Production data\ud from vein-hosted gold deposits in the Archaean Zimbabwe\ud craton display the log–normal relationship between ore\ud tonnage and grade, the multifractal nature of ore grade, and\ud the nonmultifractal nature of ore tonnage, which are\ud generated in the expanded de Wijs model