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This paper presents an evaluation of a prototype diffuse optical tomography (DOT) system. Seventeen women with 18 breast lesions (10 invasive carcinomas, 2 fibroadenomas, and 6 benign cysts; diameters 13-54 mm) were evaluated with DOT and magnetic resonance imaging (MRI). A substantial fraction of the original 36 recruited patients could not be examined using this prototype due to technical problems. A region of interest (ROI) was drawn at the lesion position as derived from MRI and at the mirror image site in the contralateral healthy breast. ROIs were assessed quantitatively and qualitatively by two observers independently in two separate readings. Intra- and interobserver agreements were calculated using kappa statistics (k) and intraclass correlation coefficients (ICCs). Discriminatory values for presence of malignancy were determined by receiver operating characteristic (ROC) analyses. Intraobserver agreements were excellent (k 0.88 and 0.88; ICC 0.978 and 0.987), interobserver agreements were good to excellent (k 0.77-0.95; ICC 0.96-0.98). Discriminatory values for presence of malignancy were 0.92-0.93 and 0.97-0.99 for quantitative and qualitative ROC analysis, respectively. This DOT system has the potential to discriminate malignant from benign breast tissue in a reproducible qualitative and quantitative manner. Important technical improvements are required before this technique is ready for clinical application. [ABSTRACT FROM AUTHOR]

More and more AFMs and AFM profilers will be used to quantify micro- and nanostructures. For a correct characterization and evaluation of the measured structural details, in the nanoscale range, knowledge of the current shape of the AFM tip is needed. Often, the interaction between the AFM tip and the sample leads to a change in the tip shape. Our concept for the determination of tip shapes is based on the measurement of a well-known sharp-edged silicon structure. Each calibration sample contains a selected structure serving as a calibrated width standard, and has a certified pitch. Consequently, the shape of AFM tips can be determined with an accuracy of 10 nm. [ABSTRACT FROM AUTHOR]