Which examinations are considered high bone marrow dose examinations?

• A. Lumbar spine radiography
• B. Retrograde urography
• C. Abdominal angiography
• D. Lumbar spine radiography, retrograde urography, and abdominal angiography

Answer: (D)

Bone marrow dose increases when the exposure covers regions where red bone marrow is concentrated and when the exam involves longer or more intense x-ray exposure. In adults, the most active red marrow sits in the pelvis and the lumbar spine, with substantial portions also in the proximal femora and other pelvic/abdominal sites. An exam that includes the pelvic region or lumbar spine, or that uses extended fluoroscopy and multiple cine radiographs over a large area, will deliver a relatively high dose to the bone marrow.

Lumbar spine radiography directly targets the spine, irradiating the vertebral bodies and their marrow, which contributes a high marrow dose for that region. Retrograde urography images the urinary tract in the abdomen and pelvis and typically involves fluoroscopy and timed radiographs in that area, spreading considerable exposure to the pelvic marrow. Abdominal angiography uses catheter-based fluoroscopy with potentially long exposure times and multiple acquisitions across the abdomen, resulting in a large irradiated volume that includes pelvic and lumbar marrow.

Because each of these procedures involves substantial irradiation of regions rich in red bone marrow, all three are considered high bone marrow dose examinations.