Brief Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Radiol. Apr 28, 2012; 4(4): 167-173
Published online Apr 28, 2012. doi: 10.4329/wjr.v4.i4.167
Virtual nonenhanced abdominal dual-energy MDCT: Analysis of image characteristics
Jacob Sosna, Shmuel Mahgerefteh, Liran Goshen, Galit Kafri, Galit Aviram, Arye Blachar
Jacob Sosna, Shmuel Mahgerefteh, Department of Radiology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
Jacob Sosna, Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA 02215, United States
Liran Goshen, Galit Kafri, Philips Healthcare, Haifa 31004, Israel
Galit Aviram, Arye Blachar, Department of Radiology, Tel Aviv Sourasky Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv 64239, Israel
Author contributions: Sosna J guaranteed the integrity for this entire study; Sosna J and Blachar A contributed to study concepts and study design; Mahgerefteh S, Goshen L and Kafri G analysed data analysi; Sosna J, Aviram G, Mahgerefteh S and Blachar A drafted manuscript; all authors approved final revision.
Correspondence to: Jacob Sosna, MD, Department of Radiology, Hadassah Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel. jacobs@hadassah.org.il
Telephone: +972-2-6776901 Fax: +972-2-6776901
Received: October 28, 2011
Revised: February 20, 2012
Accepted: February 27, 2012
Published online: April 28, 2012
Abstract

AIM: To evaluate abdominal and pelvic image characteristics and artifacts on virtual nonenhanced (VNE) images generated from contrast-enhanced dual-energy multidetector computed tomography (MDCT) studies.

METHODS: Hadassah-Hebrew University Medical Institutional Review Board approval was obtained; 22 patients underwent clinically-indicated abdominal and pelvic single-source dual-energy MDCT (Philips Healthcare, Cleveland, OH, USA), pre- and post-IV administration of Omnipaque 300 contrast (100 cc). Various solid and vascular structures were evaluated. VNE images were generated from the portal contrast-enhanced phase using probabilistic separation. Contrast-enhanced-, regular nonenhanced (RNE)-, and VNE images were evaluated with a total of 1494 density measurements. The ratio of iodine contrast deletion was calculated. Visualization of calcifications, urinary tract stones, and image artifacts in VNE images were assessed.

RESULTS: VNE images were successfully generated in all patients. Significant portal-phase iodine contrast deletion was seen in the kidney (61.7%), adrenal gland (55.3%), iliac artery (55.0%), aorta (51.6%), and spleen (34.5%). Contrast deletion was also significant in the right atrium (RA) (51.5%) and portal vein (39.3%), but insignificant in the iliac vein and inferior vena cava (IVC). Average post contrast-to-VNE HU differences were significant (P < 0.05) in the: RA -135.3 (SD 121.8), aorta -114.1 (SD 48.5), iliac artery -104.6 (SD 53.7), kidney -30.3 (SD 34.9), spleen -9.2 (SD 8.8), and portal vein -7.7 (SD 13.2). Average VNE-to-RNE HU differences were significant in all organs but the prostate and subcutaneous fat: aorta 38.0 (SD 9.3), RA 37.8 (SD 16.1), portal vein 21.8 (SD 12.0), IVC 12.2 (SD 11.6), muscle 3.3 (SD 4.9), liver 5.7 (SD 6.4), spleen 22.3 (SD 9.8), kidney 40.5 (SD 6.8), and adrenal 20.7 (SD 13.5). On VNE images, 196/213 calcifications (92%) and 5/6 renal stones (84%) were visualized. Lytic-like artifacts in the vertebral bodies were seen in all studies.

CONCLUSION: Iodine deletion in VNE images is most significant in arteries, and less significant in solid organs and veins. Most vascular and intra-abdominal organ calcifications are preserved.

Keywords: Abdominal computed tomography; Dual-energy computed tomography; Pelvic computed tomography; Virtual nonenhanced computed tomography