A new method for estimating patient body weight using CT dose modulation data

European Radiology Experimental

Table 1 Descriptive data and statistical analyses of the study population and of subgroups

	Study population	PMI ≥ 4 days	PMI < 4 days	Women	Men	Implants	No implants
Number of cases	329	89	240	78	162	38	202
Female	105	27	78	78	0	17	61
Male	224	62	162	0	162	21	141
Minimum age	18	22	18	21	18	21	18
Maximum age	95	95	94	94	94	94	94
Mean age	59.0	61.3	58.1	62.0	56.3	69.0	56.1
SD^a (±)	18.0	15.8	18.6	18.0	18.7	17.2	18.2
Minimum weight	18	18	32	32	34	34	32
Maximum weight	137	122	137	131	137	120	137
Mean weight	73.8	67.4	76.2	68.4	80.0	75.0	76.4
SD^a (±)	20.1	21.0	19.3	20.9	17.2	20.0	19.1
Minimum mAs_eff	30	30	67	75	67	67	75
Maximum mAs_eff	294	250	294	294	294	281	294
Mean mAs_eff	165.8	143.6	174.0	160.5	180.5	174.0	174.0
SD^a (±)	46.4	47.3	43.3	48.3	39.0	45.4	42.9
Pearson’s r ^b	0.931	0.854	0.966	0.974	0.960	0.969	0.966
p value^c	<0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001

The study population indicated a strong correlation between measured BW and mAs_eff values (r = 0.931). The Pearson coefficient was higher for PMI < 4 days (r = 0.966) than for PMI ≥ 4 days (r = 0.854); r was 0.974 for females with PMI < 4 days and 0.960 for males with PMI < 4 days. Further subgroups with PMI < 4 days for implants (r = 0.969) and no implants (r = 0.966) revealed both strong and nearly equal correlations. All correlation coefficients were statistically significant (p < 0.001)
^aStandard deviation
^bPearson correlation coefficient between mAs^eff and body weight
^c p value of the correlation