Abstract:
Method and system for detection of interval change in medical images. Three-dimensional images, such as previous and current section images (10 and 11) in CT scans, are obtained. An anatomic feature, such as lungs, is used to select sections containing lung by a gray-level thresholding technique (13). The section correspondence between the current and previous scans is determined automatically. The initial registration of the corresponding sections in the two scans is achieved by a rotation correction (14) and a cross-correlation (15) technique. A more accurate registration between the corresponding current and previous section images is achieved by local matching (17). A nonlinear warping process (18) which is also based on the cross-correlation technique is applied to the previous image to yield a warped image after the matching. The final subtracted section images (19) were derived by subtracting of the previous section images from the corresponding current section images. Interval changes such as a change in tumor size and a newly developed pleural effusion are enhanced significantly.
Abstract:
A method, system and computer readable medium configured for computerized detection of lung abnormalities, including obtaining a standard digital chest image (10) and a soft-tissue digital chest image; generating a first difference image from the standard digital chest image (20) and a second difference image from the soft-tissue digital chest image; identifying candidate abnormalities in the first and second difference images; extracting from the standard digital chest image and the first difference image predetermined first features of each of the candidate abnormalities identified in the first difference image; extracting from the soft-tissue digital chest image and the second difference images predetermined second features of each of the candidate abnormalities identified in the second difference image; analyzing the extracted first features and the extracted second features to identify and eliminate false positive candidate abnormalities respectively corresponding thereto; applying extracted features from remaining candidate abnormalities derived respectively from the first and second difference images and remaining after the elimination of the false positive candidate abnormalities to respective artificial neural networks to eliminate further false positive candidate abnormalities by performing a logical OR operation of the candidate abnormalities derived respectively from the first and second difference images.
Abstract:
An automated method and a computer storage medium storing instructions for executing the method, for analysis of image features in lung nodule detection in a digital chest radiographic image, including preprocessing the image to identify candidate nodules in the image (1200); establishing a region of interest (ROI) including a candidate nodule within the ROI (1210); performing image enhancement of the candidate nodule within the ROI (1220); obtaining a histogram of accumulated edge gradients as a function of radial angles within the ROI after performing the image enhancement (1230); and determining whether the candidate nodule is a false positive based on the obtained histogram (1240).
Abstract:
An automated method, and a computer storage medium storing instructions for executing the method, for analysis of image features in lung nodule detection in a chest radiographic image represented by digital data, including preprocessing the image to identify candidate nodules in the image; establishing a region of interest (ROI) including a candidate nodule identified in the preprocessing step; performing image enhancement of the candidate nodule within the ROI; obtaining a histogram of accumulated edge gradients as a function of radial angles withing the ROI after performing the image enhancement; and determining whether the candidate nodule is a false positive based on the obtained histogram. A 64x64-pixel region of interest (ROI) centered at the candidate location is used. The contrast of the ROI is improved by a two-dimensional background subtraction. A nodule shape matched filter is used for enhancement of the nodular pattern located in the central area of the ROI. Analysis of the histogram resulted in identification of seven features, including (1) a maximum histogram value, (2) a minimum histogram value, (3) a partial average value of the histogram, (4) a standard deviation of the histogram values near the radial axis, (5) a partial standard deviation of histogram values, (6) a width of the histogram including both sides from zero degrees of the radial angle, at a predetermined histogram value, and (7) a ratio of a maximum histogram value near the radial axis to a maximum histogram value in two predetermined outside ranges of the radial axis, useful for the identification and elimination of false positives.