Table 8. Comparison of derived Hounsfield unit (HU) phantom in small water container with cone beam CT (CBCT) scanners.
Asahi Alphard 3030 80 kV 5 mA | Hitachi CB MercuRay 120 kV 10 mA | Imaging Sciences i-Cat 120 kV 10s, 12 mA 0.4 mm voxel | Imaging Sciences i-Cat Next Generation 120 kV 5 mA | Imtec Iluma 120 kV 3.8 mA 0.3 mm voxel | Morita Accuitomo FPD 70 kV 7 mA | Morita Veraview Epochs 80 kV 5 mA | NewTom VG 110 kV 1 mA | Planmeca ProMax 3D 82 kV 10 mA | Sirona Galileos 85 kV 35 mAs | Soredex Scanora 3D 85 kV 15 mA | Philips Briliance 64 CT 120 kV 300 mA | Toshiba Aquilion CT 120 kV 300 mA | |
Original grey levels | |||||||||||||
Aluminium | 1595.7 | 565.6 | 2134.4 | 215.1 | 1713.7 | 2255.6 | 2342.5 | 1525.7 | 922.5 | 1053.9 | 1672 | 2339 | 2409.1 |
Outer bone equivalent | 1167.4 | 377.9 | 1371.9 | −99.4 | 1111.4 | 1514.3 | 1750.5 | 972.7 | 537.6 | 819.8 | 1127 | 1479.5 | 1492.3 |
Inner bone equivalent | 216.5 | −165.2 | 255.2 | −517.7 | 192.1 | −178.6 | 490.7 | 63.3 | 152.5 | 386.6 | 184 | 252 | 310.1 |
PMMA | −27 | −245.8 | 63.5 | −597.6 | 64.7 | −538.5 | 120 | −110.1 | −300.2 | 342.4 | −49 | 130 | 139.9 |
Muscle equivalent | −32 | −286.5 | −4.6 | −625 | −1.4 | −590.1 | 119.5 | −154.6 | −320 | 328.9 | −58.4 | 15.7 | 61.4 |
Water equivalent | 56.9 | −310.3 | −26.9 | −637.9 | −19.6 | −593.6 | 74.1 | −171.4 | −323.5 | 310.1 | −96 | 33.7 | 41.7 |
Adipose equivalent | −159.7 | −403.6 | −169.8 | −699.5 | −145.2 | −775.7 | −96.9 | −280.5 | −395.9 | 251.2 | −214.7 | −97.1 | −106.6 |
Air | −707.7 | −852.5 | −995.1 | −999.7 | −956.7 | −999.5 | −918.6 | −818 | −771.7 | −52.7 | −801.7 | −1009.1 | −1025 |
Corrected HU | |||||||||||||
Aluminium | 3017.7 | 1868.8 | 2301.0 | 2156.0 | 2130.0 | 2962.1 | 2962.1 | 2366.1 | 2953.6 | 2223.2 | 2636.2 | 2301.0 | 2499.8 |
Outer bone equivalent | 2214.4 | 1469.8 | 1496.2 | 1367.5 | 1395.2 | 2157.7 | 2195.8 | 1597.1 | 2049.2 | 1529.0 | 1824.8 | 1450.6 | 1535.9 |
Inner bone equivalent | 431.0 | 315.3 | 317.6 | 318.7 | 273.7 | 436.1 | 565.1 | 332.5 | 1144.4 | 244.3 | 421.0 | 236.0 | 293 |
PMMA | −25.6 | 144.0 | 115.3 | 118.4 | 118.3 | 70.1 | 85.3 | 91.4 | 80.7 | 113.2 | 74.1 | 115.2 | 114.1 |
Muscle equivalent | −35.0 | 57.5 | 43.4 | 49.7 | 37.7 | 17.6 | 84.7 | 29.5 | 34.2 | 73.2 | 60.1 | 2.1 | 31.5 |
Water equivalent | 131.7 | 6.9 | 19.9 | 17.3 | 15.5 | 14.1 | 25.9 | 6.1 | 25.9 | 17.4 | 4.1 | 20.0 | 10.8 |
Adipose equivalent | −274.5 | −191.4 | −130.9 | −137.1 | −137.7 | −171.1 | −195.5 | −145.6 | −144.2 | −157.2 | −172.6 | −109.5 | −145.1 |
Air | −998.9 | −998.9 | −1000.0 | −889.8 | −998.9 | −398.7 | −1259.1 | −893.0 | −998.9 | −998.9 | −1046.4 | −1011.9 | −1110.7 |