Atul Padole MD, Presenter: Nothing to Disclose

Sarabjeet Singh MD, Abstract Co-Author: Research Grant, Siemens AG Research Grant, Toshiba Corporation Research Grant, General Electric Company Research Grant, Koninklijke Philips NV

Yiming Gao, Abstract Co-Author: Nothing to Disclose

Ranish Deedar Ali Khawaja MD, Abstract Co-Author: Nothing to Disclose

Diego Alfonso Lira MD, Abstract Co-Author: Nothing to Disclose

Mannudeep K. S. Kalra MD, Abstract Co-Author: Nothing to Disclose

Madan M. Rehani, Abstract Co-Author: Nothing to Disclose

Da Zhang PhD, Abstract Co-Author: Nothing to Disclose

Bob Liu PhD, Abstract Co-Author: Nothing to Disclose

George Xu PhD, Abstract Co-Author: Nothing to Disclose

To compare the estimated organ doses obtained from two radiation dose estimation software for chest CT examinations in adult patients of different sizes.

In an IRB-approved, HIPAA compliant study, we included 60 patients (mean age: 62 ± 9 years; M: F=29:31) undergoing chest CT for lung nodule follow up on a 16-slice MDCT (GE LightSpeed Pro 16). Based on weight, patients were divided into 3 groups (20 patients each); < 61 kg, 61-91 kg, and > 91 kg. Automatic dose monitoring software, eXposure (Radimetrics Inc.) and VirtualDose (Virtual Phantoms, Inc.) were used to obtain patients’ organ doses. Organ doses for following organs adrenal glands, breast, esophagus, heart, lungs, stomach, liver, spleen, and kidney were recorded form two software was calculated. Scan parameters including kV, fixed mAs, scan length, rotation time, pitch, and beam collimation, CTDIvol, and DLP were also recorded. The difference between organ doses obtained from software. Paired t-tests were used to compare difference in the organ doses, P-value of 0.05 with 95% confidence interval was considered significant.

The mean CTDIvol were 3.2 mGy (<61 kg), 4.8 mGy (61-91 kg), and 7 mGy (>91 kg). The organ doses for adrenal glands, breast, esophagus, heart, lungs, stomach, liver, spleen, and kidney obtained from eXposure were significantly greater compared to organ doses obtained from VirtualDose software (p<0.001). Mean (± standard deviation) difference in organ doses between the both software were 1.24 ± 0.6 mSv (<61 kg), 2.1 ± 0.8 mSv (61-91 kg), 3.9 ± 1.2 mSv (>91 kg) (p<0.001). The minimum and maximum difference in organ doses estimated with the two software was for adrenal (12-14%) and esophagus (53-61%), respectively.

The organ doses obtained from eXposure software were substantially greater compared to VirtualDose software for patients with different weight group. Marked difference in the organ doses was noted for patients with greater body weight.

Accurate determination of patient size is important for estimating organ doses as observed with radiation dose estimating software.

Padole, A, Singh, S, Gao, Y, Khawaja, R, Lira, D, Kalra, M, Rehani, M, Zhang, D, Liu, B, Xu, G, Comparison of Estimated Organ Doses with Two Radiation Dose Estimation Software.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14008150.html