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. Author manuscript; available in PMC: 2016 Aug 19.
Published in final edited form as: AAPM Rep. 2014 Sep;2014:6–23.

Table A-1.

This table provides conversion factors based on the use of the 32 cm diameter PMMA phantom for CTDIvol. Other than the clarification that the effective diameter in the data table is equivalent to Dw, it is identical to Table 1 in AAPM Report 204.

Table 1A Table 1B Table 1C Table 1D
Lat + AP Dw Conversion Lateral Dw Conversion AP Dw Conversion Dw Conversion
Dim (cm) (cm) Factor Dim (cm) (cm) Factor Dim (cm) (cm) Factor (cm) Factor
16 7.7 2.79 8 9.2 2.65 8 8.8 2.68 8 2.76
18 8.7 2.69 9 9.7 2.60 9 10.2 2.55 9 2.66
20 9.7 2.59 10 10.2 2.55 10 11.6 2.42 10 2.57
22 10.7 2.50 11 10.7 2.50 11 13.0 2.30 11 2.47
24 11.7 2.41 12 11.3 2.45 12 14.4 2.18 12 2.38
26 12.7 2.32 13 11.8 2.40 13 15.7 2.08 13 2.30
28 13.7 2.24 14 12.4 2.35 14 17.0 1.98 14 2.22
30 14.7 2.16 15 13.1 2.29 15 18.3 1.89 15 2.14
32 15.7 2.08 16 13.7 2.24 16 19.6 1.81 16 2.06
34 16.7 2.01 17 14.3 2.19 17 20.8 1.73 17 1.98
36 17.6 1.94 18 15.0 2.13 18 22.0 1.65 18 1.91
38 18.6 1.87 19 15.7 2.08 19 23.2 1.58 19 1.84
40 19.6 1.80 20 16.4 2.03 20 24.3 1.52 20 1.78
42 20.6 1.74 21 17.2 1.97 21 25.5 1.45 21 1.71
44 21.6 1.67 22 17.9 1.92 22 26.6 1.40 22 1.65
46 22.6 1.62 23 18.7 1.86 23 27.6 1.34 23 1.59
48 23.6 1.56 24 19.5 1.81 24 28.7 1.29 24 1.53
50 24.6 1.50 25 20.3 1.76 25 29.7 1.25 25 1.48
52 25.6 1.45 26 21.1 1.70 26 30.7 1.20 26 1.43
54 26.6 1.40 27 22.0 1.65 27 31.6 1.16 27 1.37
56 27.6 1.35 28 22.9 1.60 28 32.6 1.12 28 1.32
58 28.6 1.30 29 23.8 1.55 29 33.5 1.08 29 1.28
60 29.6 1.25 30 24.7 1.50 30 34.4 1.05 30 1.23
62 30.5 1.21 31 25.6 1.45 31 35.2 1.02 31 1.19
64 31.5 1.16 32 26.6 1.40 32 36.0 0.99 32 1.14
66 32.5 1.12 33 27.6 1.35 33 36.8 0.96 33 1.10
68 33.5 1.08 34 28.6 1.30 34 37.6 0.93 34 1.06
70 34.5 1.04 35 29.6 1.25 35 38.4 0.91 35 1.02
72 35.5 1.01 36 30.6 1.20 36 39.1 0.88 36 0.99
74 36.5 0.97 37 31.7 1.16 37 39.8 0.86 37 0.95
76 37.5 0.94 38 32.7 1.11 38 40.4 0.84 38 0.92
78 38.5 0.90 39 33.8 1.07 39 41.1 0.82 39 0.88
80 39.5 0.87 40 34.9 1.03 40 41.7 0.80 40 0.85
82 40.5 0.84 41 36.1 0.98 41 42.3 0.78 41 0.82
84 41.5 0.81 42 37.2 0.94 42 42.8 0.77 42 0.79
86 42.4 0.78 43 38.4 0.90 43 43.4 0.75 43 0.76
88 43.4 0.75 44 39.6 0.87 44 43.9 0.74 44 0.74
90 44.4 0.72 45 40.8 0.83 45 44.4 0.73 45 0.71