A port film marker.
A device is described consisting of brass strips embedded in a plastic plate. When inserted in a radiation beam, it produces an image of a cross centered in the field. Cuts in the brass at defined intervals project a scale on the film used to determine a magnification factor. A marker in the lower right-hand quadrant provides rapid, unequivocal orientation of the film. This capability of orientation to a beam's-eye-view makes anatomical markers redundant.
Jones
D
D
Northwest Medical Physics Center, Lynnwood, WA 98036.
Armstrong
J
J
Hafermann
M D
MD
D004867:Equipment Design; D006801:Humans; D011187:Posture; D011859:Radiography / Q000295:instrumentation*; D014962:X-Ray Film