Automatic contour brain scanning is compared with manual and rectilinear scanning methods. The contour scan chart corresponds closely to anatomic features, and the method allows the radiation detectors to “see” a relatively uniform volume of tissue with a more constant ratio of skull and scalp tissue to brain tissue. Foreshortening and distortion of the curved surfaces of the head are reduced to a minimum. The method is not restricted to any particular isotope. Radioactive iodinated human serum albumin is especially suitable for brain scanning because it exploits the normal selective permeability of the blood-brain barrier and also gives an indication of lesions with increased vascularity.