1. A method for segmenting a sheet object represented in an image generated using radiation imaging modality, comprising: identifying a plurality of elements in the image, respective elements associated with a value; for a first element of the plurality of elements: selecting a first plurality of neighboring elements in spatial proximity to the first element to define a first neighborhood and a second plurality of neighboring elements in spatial proximity to the first element to define a second neighborhood; computing a constant false alarm rate (CFAR) score for the first element, the CFAR score determined by comparing the value associated with the first element to a statistical measure for the first neighborhood; computing a topological score for the first element, the topological score determined by comparing the value associated with the first element to respective values associated with elements comprised within the second neighborhood, wherein computing the topological score for the first element, comprises: comparing the value associated with the first element to respective values associated with elements comprised within the second neighborhood; and at least one of: determining a number of neighboring elements comprised within the second neighborhood that are associated with values within a specified range of the value associated with the first element; or determining a number of neighboring elements comprised within the second neighborhood that are associated with values outside of the specified range of the value associated with the first element; and labeling the first element as being associated with the sheet object when the CFAR score is within a first specified range and when the topological score is within a second specified range.