CAT Scan	Effective radiation dose
CT-Abdomen	10 mSv
CT-Body	10 mSv
CT-Spine	10 mSv
CT-Chest	8 mSv
CT-Head	2 mSv
CT - Heart	2 mSv
CT-Sinuses	0.6 mSv

X-rays	Effective radiation dose
X-ray lower abdomen	4 mSv
X-ray upper abdomen	2 mSv
Intravenous Pyelogram (IVP)	1.6 mSv
Voiding Cystourethrogram (VCUG / MCU)	5-10 yr. old: 1.6 mSv
	Infant: 0.8 mSv
X-ray Chest	0.1 mSv

Other radiological tests	Effective radiation dose
Myelography	4 mSv
Mammography	0.7 mSv
Bone Densitometry (DEXA)	0.01 mSv

Effective radiation dose	Comparable Natural Background Radiation
10 mSv	3 years
8 mSv	8 months
4 mSv	16 months
2 mSv	8 months
1.6 mSv	6 months
0.8 mSv	3 months
0.7 mSv	3 months
0.6 mSv	2 months
0.1 mSv	10 days
0.01 mSv	1 day

Ultrasound uses acoustic radiation and, at current intensities, no risk is known to exist for this type of imaging procedure. Unlike conventional x-ray examinations and computed tomography (CT) scans, MRI does not depend on radiation. Instead, radio waves are directed at protons, the nuclei of hydrogen atoms, in a strong magnetic field.