Table 2.

Analysis of variance

		N	Mean	Std. Deviation	Minimum	Maximum
ESD	SW1	20	18.58	6.31	10.33	31.07
	SW2	20	15.18	2.27	10.94	18.61
	SW3	20	17.44	3.43	11.45	21.99
	SW4	20	34.24	11.98	20.04	61.22
	Total	80	21.36	10.28	10.33	61.22
kVp	SW1	20	92.10	5.71	84.00	100.00
	SW2	20	74.70	3.40	70.00	78.00
	SW3	20	91.65	6.82	82.00	105.00
	SW4	20	87.25	3.80	80.00	90.00
	Total	80	86.43	8.68	70.00	105.00
mAs	SW1	20	26.20	2.59	24.00	30.00
	SW2	20	26.80	4.74	20.00	32.00
	SW3	20	34.50	15.97	25.00	75.00
	SW4	20	82.10	20.01	64.00	125.00
	Total	80	42.40	26.60	20.00	125.00
FDD	SW1	20	100.75	5.91	90.00	110.00
	SW2	20	103.50	4.89	100.00	115.00
	SW3	20	100.75	5.91	90.00	110.00
	SW4	20	96.00	13.73	70.00	110.00
	Total	80	100.25	8.67	70.00	115.00
FSD	SW1	20	71.75	2.88	65.00	75.00
	SW2	20	78.05	4.08	72.00	89.00
	SW3	20	74.15	4.37	68.00	83.00
	SW4	20	70.25	13.04	41.00	88.00
	Total	80	73.55	7.76	41.00	89.00
BMI	SW1	20	26.58	3.19	21.48	34.77
	SW2	20	23.64	2.38	19.92	28.13
	SW3	20	25.59	2.89	19.14	30.08
	SW4	20	26.31	2.62	21.88	31.25
	Total	80	25.53	2.97	19.14	34.77
Age	SW1	20	35.90	4.81	27.00	49.00
	SW2	20	36.00	3.32	30.00	41.00
	SW3	20	34.35	3.13	28.00	40.00
	SW4	20	33.70	3.28	29.00	39.00
	Total	80	34.99	3.76	27.00	49.00

ESD = entrance surface dose, kVp = Kilovoltage peak, mAs = current time product, FDD = focus detector distance, FSD = focus skin distance, BMI = Body mass index