Abstract
The placenta previa was determined using 99mTc. H. S. A. by isosensitive colour scintillation scanning in 2 patients in the third trimester of pregnancy.
The measurements of the count per minute (c. p. m. ) were carried out by isosensitive scanning using two collimated detectors as two pens method. The technique of application of the isosensitive scana is fully described and its superiority in accuracy, simplicity and danger of radiation discussed.
Of the 2 patients with recurrent vaginal bleeding who were performed by cesarean section, one patient was found to be in the right lower posterior marginal placenta previa indicated on the colour isosensitive scanning and the other was also found to be in the right lower posterior lying placenta indicated on the same scanning.
No failure in the diagnosis of placental site was noted. Because of the precise localization of the placenta, this colour placentography and the measurement of the count per minute of γ emission shows promise of improving the diagnosis of placental previa and management of third trimester bleeding
