Alexi Otrakji MD, Presenter: Nothing to Disclose

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

Efren Jesus Flores MD, Abstract Co-Author: Nothing to Disclose

Roberto Lo Gullo MD, Abstract Co-Author: Nothing to Disclose

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

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

There are little data to support use of DECT of chest in large patients. The purpose of our study was to evaluate the performance of dual energy routine chest CT in large patients for providing required diagnostic information and image quality

Our study included 45 patients(M:F 31:14, mean age 53± 13years,mean weight 130±14kg) who underwent contrast enhanced chest CT using dual energy protocol on 128-slice dual source MDCT(Somatom Definition Flash, Siemens) or single source 64-row MDCT (GE 750HD Discovery) scanners. Inclusion criteria for the study included consecutive patients over 114 Kg (>250 lbs) who underwent routine contrast enhanced CT of the chest with DECT.Following DECT image series were generated for each patient - monoenergetic 60 kev, 100 Kev, pulmonary blood volume (PBV) and virtual non contrast (VNC). All image series were assessed qualitatively for thoracic abnormality, level of pulmonary arterial enhancement, diagnostic quality, image noise, and artifacts. The CTDIvol and DLP were recorded and compared to 60 weight matched patients who underwent routine chest CT with single energy on the same scanners.

Radiation dose for patients who underwent chest DECT(10 ±2.4mGy,350±67mGy.cm) was significantly lower as compared to the weight matched single energy chest CT(15±2.6mGy, 576±147mGy.cm) (p<0.001).Pulmonary arterial enhancement was optimal to excellent in 84% patients(38/45) up to lobar level and in 71%(32/45) patients in segmental branches. There was significant reduction in image noise and artifacts at the level of the tracheal carina and diaphragm on 100 Kev images compared to the 60 kev images (p<0.001).There was a significant improvement in acceptable diagnostic quality with 100 Kev (93%) compared to 60 Kev images (76%).Excellent or optimal diagnostic quality was noted in 80% of patients on PBV and VNC images,but was limited or suboptimal in other larger patients due to marked beam hardening artifacts

Routine chest CT with dual energy technique can provide optimal diagnostic information and diagnostic quality in most large patients at lower radiation dose compared to the single energy chest CT. 100 kev images are helpful in reducing noise and artifacts.

Routine chest CT with dual energy technique needs additional higher kev (100) images for obtaining optimal diagnostic information in large patients.

Otrakji, A, Kalra, M, Flores, E, Lo Gullo, R, Shepard, J, Digumarthy, S, Diagnostic Quality and Limitations of Dual Energy CT of the Chest in Large Adult Patients.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14018552.html