Bone marrow imaging using 111In-citrate: 111In-kinetics in the pelvic region

When bone marrow scintigraphy was performed using 111In-citrate, radioactivity was observed in the pudendal region. Subsequently, the kinetics of 111In in the pelvic region after intravenous administration of 111In-citrate for bone-marrow scanning in 14 patients was examined. On the first day, radioindium was found predominantly in the large pelvic blood vessels and in the pudendal region. In all male patients, the scrotal area was affected with both testes presumably delineated in two patients. In the female patients little radioindium was detected in the pudendal region, most probably in the vulva; distinct radioactivity was found in the pelvis although the ovaries could not be identified. In the following period the 111In uptake in the bone marrow increased considerably and reached its maximum usually 24 hr after the injection. Because a distinct radiation dose from 111In to the gonads cannot be excluded on the basis of our scintigraphic findings and the absorbed dose has not yet been estimated sufficiently, judgment should be used for the present if 111In-citrate is applied for bone marrow imaging.