Alexi Otrakji MD, Presenter: Nothing to Disclose

Roberto Lo Gullo MD, Abstract Co-Author: 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

Katherine Stockton, Abstract Co-Author: Nothing to Disclose

Jo-Anne O. Shepard MD, Abstract Co-Author: Consultant, Agfa-Gevaert Group

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

Subba Rao Digumarthy MD, Abstract Co-Author: Nothing to Disclose

Atul Padole MD, Abstract Co-Author: Nothing to Disclose

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

Sarvenaz Pourjabbar MD, Abstract Co-Author: Nothing to Disclose

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

To compare radiation dose associated with single-KV (sK-CT) and dual-kV (dK-CT) chest CT examinations for routine chest (RC) and pulmonary embolism (PE) protocols across two CT vendors.

Our IRB approved study included 824 adult patients who had contrast enhanced sK-CT using RC (n= 210 patients) dual source CT, 128-DSCT (Siemens Definition Flash):100 patients, M:F 56:44,mean age 60±15 years,mean weight 78±23 kg; 64-slice single source CT 64-SSCT,GE Discovery 750HD:110 patients,M:F 58:52, mean age 60 ± 17years,mean weight 75±19 kg) and PE protocols(n= 202 patients) (128-DSCT: 92 patients,M:F 37:55,mean age 62 ± 16years,mean weight 80±24 kg; 64-SSCT:110 patients,M:F 52:58,mean age 62±16years,mean weight 81±22kg) and dK-CT using RC (n= 210 patients)(128-DSCT: 100 patients,M:F 48:52,mean age 59 ±16years,mean weight 77±19kg; 64-SSCT:110 patients M:F 48:62,mean age 63±14years,mean weight 73±16kg) and PE protocols (n= 202 patients)(128-DSCT:92 patients,M:F 37:55,mean age 55±18years,mean weight 79±25kg; 64-SSCT:110 patients, M:F 53:57,mean age 61±16years,mean weight 80±21kg).For each patient,we recorded CTDIvol,DLP and estimated effective dose (EED).Data were analyzed using Student’s t test and ANOVA.

There was no significant difference between weights of the patients undergoing sK-CT and dK-CT on the two CT scanners for RC and PE protocols (p=0.4).Following doses were noted for dK-CT: RC (64-SSCT):7.6±0.7mGy,288±37 mGy.cm, 4±0.5mSv; RC (128-DSCT):6.6±2.8mGy,220±99mGy.cm, 3.1±1.4mSv;PE (64-SSCT):9.3 ± 2 mGy, 326±70 mGy.cm, 4.6±1mSv; PE (128-DSCT):9±3.2mGy, 284±104mGy.cm, 4±1.5mSv.There was significant reduction in CTDIvol with dK-CT as compared to the sK-CT, ranging from 11-43% (p<0.0001).The dK-CT on 128-DSCT resulted in 4-16% lower CTDI vol as compared to dK-CT acquisition on 64-SSCT (p<0.01). Patient weight had significant effect on dose reduction with dK-CT as compared to the sK-CT, with mean dose reduction of 19% for patients < 90 kg (7.2 versus 8.8 mGy) versus 30% dose reduction for patients > 90 kg (11.1 versus 16.8 mGy) (p<0.001).

Routine chest CT, and pulmonary embolism CT protocols can be performed using dual kV acquisition mode at lower radiation dose levels compared to the single kV acquisition

Dual kV CT can be applied for acquiring routine chest CT and pulmonary embolism CT without any dose penalty compared to single energy chest CT

Otrakji, A, Lo Gullo, R, Singh, S, Stockton, K, Shepard, J, Kalra, M, Digumarthy, S, Padole, A, Khawaja, R, Pourjabbar, S, Lira, D, Radiation Dose from Single-KV and Dual-KV chest CT for Routine Chest and Pulmonary Embolism Protocols.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017088.html