Improved precision of noise estimation in CT with a volume-based approach

European Radiology Experimental

Table 1 Patient cohort characteristics (n = 49)

Characteristic	Value
Age (years)	66 ± 7
Sex	34 males (69%), 15 females (31%)
Body mass index (kg/m²)	28.0 ± 5.3
FEV₁ (% of predicted)	53 ± 16
FEV₁/FVC (%)	42.4 ± 11.2
CTDIvol (mGy), regular CT protocol	3.04
DLP (mGy × cm), regular CT protocol	105.1 (86.3−134.1)
CTDIvol (mGy), ultra-low dose CT protocol	0.38 (0.19−1.06)
DLP (mGy × cm), ultra-low dose CT protocol	16.6 (7.3−29.8)

Values are given as mean ± standard deviation or median (range), unless stated otherwise. To facilitate comparison, the DLP for the regular-dose CT is expressed as median (range), despite a normal distribution (p = 0.103). CT computed tomography, FEV₁ forced expiratory volume in 1 s; FVC forced vital capacity, CTDIvol volumetric CT dose index, DLP dose length product