In 61 cases of suspected placenta praevia, plain roentgenograms were made according to gravitational methods advocated by Reid and Hodge. In 47 cases such roentgenograms alone correctly excluded the diagnosis of placenta praevia. Among the other 14, the roentgenographic findings indicated either a major or a minor degree of placenta praevia. In all but one of them, a sterile vaginal examination was carried out by the obstetrician in the operating room, with all personnel and equipment ready for immediate cesarean section if necessary. The combined roentgenologic and obstetrical procedure led to accurate and appropriate management in every instance. The combined approach requires no special equipment or injection procedure. The minimal exposure to ionizing radiation is considered to be justified because of the great immediate danger to both mother and fetus in placenta praevia.
Behlke FM, Fischer HW, Goddard WB. A Report on Gravitational Placentography. JAMA. 1961;178(5):455–461. doi:10.1001/jama.1961.03040440007002