1. A device for detecting whether pulmonary nodules are present in a patient's lung region from a three-dimensional (3D) data set representative of a volumetric image of the patient's lung region, the device comprising: a processor configured to (1) identify contiguous structures in the 3D data set, (2) classify the identified contiguous structures according to a plurality of classifications, the classifications comprising a vessel contiguous structure classification and a non-vessel contiguous structure classification, wherein each non-vessel contiguous structure comprises a nodule candidate, (3) apply a first nodule detection operation to each vessel contiguous structure to determine a nodule status therefor, and (4) apply a second nodule detection operation to each non-vessel contiguous structure to determine a nodule status therefor, wherein the first nodule detection operation is different than the second nodule detection algorithm; wherein the processor is further configured to apply the first nodule detection operation by (1) segmenting nodule candidate structures from surrounding vessel structures through a correlation of each vessel contiguous structure with a 3D morphological filter, and (2) determining a nodule status for each segmented nodule candidate; wherein the processor is further configured to apply the second nodule detection operation by determining a nodule status for each non-vessel nodule candidate at least partially on the basis of geometric criteria; wherein the processor is further configured to determine the nodule status for each non-vessel nodule candidate by comparing each nodule candidate with a compactness criteria; and wherein the processor is further configured to compare each non-vessel nodule candidate with the compactness criteria by: for each non-vessel nodule candidate, (1) determining a volume of that non-vessel nodule candidate, (2) determining a volume of the smallest 3D box that encloses that non-vessel nodule candidate, and (3) computing a ratio of the determined non-vessel nodule candidate volume to the determined box volume; and for each non-vessel nodule candidate having a determined volume ratio less than approximately 0.5 or greater than approximately 1.5, determining that that non-vessel nodule candidate is not a pulmonary nodule.