Seeing is believing with the Atlas of Normal Roentgen Variants That May Simulate Disease, 9th Edition, edited by the late Theodore Keats and Mark W. Anderson. This medical reference book's thousands of images capture the roentgenographic presentation of a full range of normal variants and pseudo-lesions that may resemble pathologic conditions, helping you avoid false positives. You'd be hard pressed to find a comparable image collection in any one place online.