Patent ID: 7305111

Claim:
A method for detecting at least one nodule in a medical image of a subject, comprising: identifying, in said medical image, an anatomical region corresponding to at least a portion of an organ of interest; filtering said medical image to obtain a difference image; detecting, in said difference image, a first plurality of nodule candidates within said anatomical region; calculating respective nodule feature values of said first plurality of nodule candidates based on image pixel values of at least one of said medical image and said difference image; removing false positive nodule candidates from said first plurality of nodule candidates based on said respective nodule feature values to obtain a second plurality of nodule candidates; and determining said at least one nodule by classifying each of said second plurality of nodule candidates as a nodule or a non-nodule based on at least one of said image pixel values and said respective nodule feature values, wherein said detecting step includes determining a respective center pixel having a maximum pixel value within a respective nodule region of each nodule candidate in the first plurality of nodule candidates; calculating, for a first respective subregion that includes said respective center pixel within each respective nodule region, at least one first morphological image feature, said first respective subregion defined as those pixels having a pixel value above a first pixel threshold, but less than said maximum pixel value; calculating, for a second respective subregion that includes said respective center pixel within each respective nodule region, at least one second morphological image feature, said second respective subregion defined as those pixels having a pixel value above a second pixel threshold, but less than said maximum pixel value; and determining said respective nodule region of each nodule candidate based on respective differences between the at least one first morphological image feature and the at least one second morphological image feature.