A method of creating a well image log of a cased well is provided. A passive cased well image logging tool assembly including a logging tool body, a plurality of gamma ray radiation sensor assemblies and a spatial positioning device is moved through at least a portion of the wellbore. Corrected gamma ray radiation data is vertically sampled. Based on the sampled data, a well image log is prepared. A passive cased well image logging tool assembly for use in a cased well is also provided.