Table 6.

Mean and spread (±) of the HU values, calculated from measured histograms for the three different diameter cylinders, filled with three water: methanol (W:M) mixtures

Composition	Diameter	AZOR						Saddle
	(cm)	Top		Mid		Bottom		Top		Mid		Bottom
		Mean	Spread	Mean	Spread	Mean	Spread	Mean	Spread	Mean	Spread	Mean	Spread
100:0 (W:M)	15	7.03	150.00	5.42	110.00	−28.94	500.00	−18.68	92.00	−10.05	80.00	16.69	90.00
	12.5	−23.59	100.00	2.66	75.00	−45.64	350.00	−9.31	75.00	−0.33	75.00	−9.28	62.00
	10	8.49	80.00	7.14	65.00	−62.32	175.00	10.91	70.00	4.24	60.00	−11.00	62.50
75:25 (W:M)	15	−51.23	100.00	−39.69	85.00	27.67	400.00	−58.51	90.00	−41.82	70.00	2.40	85.00
	12.5	−37.99	110.00	−32.26	65.00	37.72	350.00	−39.17	90.00	−38.96	65.00	−8.61	70.00
	10	−42.04	60.00	−35.76	60.00	27.35	230.00	−32.79	50.00	−38.46	55.00	−40.48	65.00
50:50 (W:M)	15	−76.33	140.00	−99.14	60.00	−42.74	500.00	−105.83	75.00	−110.22	60.00	−79.87	75.00
	12.5	−89.07	110.00	−92.39	60.00	−66.78	500.00	−94.60	70.00	−99.45	55.00	−81.49	75.00
	10	−106.24	65.00	−93.58	95.00	−74.30	380.00	−93.43	60.00	−90.42	82.00	−83.46	65.00

Top, Mid and Bottom correspond to slices 150, 350 and 500 respectively, used to measure histograms. Bottom slice values for AZOR show the highest HU spread due to the shading artifact. Saddle values overall show tighter distribution and better accuracy.