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. 2014 Sep:2014:6-23.

Use of Water Equivalent Diameter for Calculating Patient Size and Size-Specific Dose Estimates (SSDE) in CT: The Report of AAPM Task Group 220

Cynthia McCollough  1 , Donovan M Bakalyar  2 , Maryam Bostani  3 , Samuel Brady  4 , Kristen Boedeker  5 , John M Boone  6 , H Heather Chen-Mayer  7 , Olav I Christianson  8 , Shuai Leng  1 , Baojun Li  9 , Michael F McNitt-Gray  3 , Roy A Nilsen  10 , Mark P Supanich  11 , Jia Wang  12
Affiliations

Use of Water Equivalent Diameter for Calculating Patient Size and Size-Specific Dose Estimates (SSDE) in CT: The Report of AAPM Task Group 220

Cynthia McCollough et al. AAPM Rep. 2014 Sep.
No abstract available

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Figures

Figure 1
Figure 1
Phantoms used for estimating Dw from CT localizer radiographs and CT images: (a) water cylinders, (b) torso-shaped phantoms with a PMMA shell filled with water, (c) water equivalent torso phantoms, (d) semi-anthropomorphic thorax phantom with extension rings for mimicking larger patient sizes, and (e) anthropomorphic thorax phantom.
Figure 2
Figure 2
Comparison of effective diameter and Dw for a patient data set. A threshold of −383 HU was used to remove the patient table for every 10th image in the data set. The segmented ROIs are shown in (a). The area and mean CT number of the ROI in each axial image were used to calculate effective diameter and Dw,, which are superimposed on a coronal reformation of the patient data in (b). This visually demonstrates that the use of effective diameter will overestimate Dw in the thorax.
Figure 3
Figure 3
Minification (a) or magnification (c) of the patient's lateral dimensions occurs when the patient is not well centered in the FOV (b).
See this image and copyright information in PMC

References

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