Table 5.

Comparison between volume-weighted CT dose index (CTDI_vol) and patient-specific organ dose, and comparison between effective dose derived from DLP using published conversion coefficients and effective dose estimated using patient-specific organ dose values.

	Newborn (5 weeks, female)		Teenager (12 years, male)
	Chest	Abdomen-pelvis	Chest	Abdomen-pelvis
Large organ dose (mGy) a
Approximated by CTDIvolb	2.21	4.77	2.24	2.74
Estimated for specific patient	3.62	6.82	4.04	5.25
Discrepancy	−39%	−30%	−44%	−48%
Effective dose (mSv)
Derived from DLPc	1.18	5.18	0.66	1.57
Estimated for specific patient (ICRP 103)	1.64	4.04	1.78	3.15
Estimated for specific patient (ICRP 60)	1.37	4.60	1.52	3.64
Discrepancy (DLP VS ICRP 103)	−28%	28%	−63%	−50%
Discrepancy (DLP VS ICRP 60)	−14%	13%	−56%	−57%
Discrepancy (ICRP 60 VS ICRP 103)	−16%	14%	−15%	16%

^aAverage dose to large organs inside the scan coverage, represented by lung and heart for the chest scan and liver and small intestine for the abdomen-pelvis scan.

^bThe scan FOV used for each patient (Table 1) determined the corresponding CTDI phantom size: 16 cm diameter and 32 cm diameter phantoms for the newborn and the teenager patients, respectively.

^cThe DLP was 30.34 and 105.77 mGy- cm for chest and abdomen-pelvis scans of the newborn patient, and 51.14 and 104.99 mGy- cm for chest and abdomen-pelvis scans of the teenager patient.