Methods are disclosed for analyzing representations of one or more structures in the body of a subject (e.g., a human subject or other animal subject) to glean information about the health of the subject or to evaluate the subject's response to a therapy or other condition. Aspects of the invention relate to obtaining structural information from casts (e.g., vascular casts from animal models) and using the information as a reference for evaluating structures in the body of a subject. Methods are disclosed for diagnosing, staging, grading, and monitoring diseases. Methods also are disclosed for targeting treatments, monitoring the effectiveness of therapies, and/or screening or validating therapies based analyzing structures (e.g., vascular structures) in a subject and comparing them to reference structures observed in casts obtained from models (e.g., animal models) of related diseases or conditions.