Satoshi Goshima MD, PhD, Abstract Co-Author: Nothing to Disclose

Yusuke Tsuge MD, Abstract Co-Author: Nothing to Disclose

Daisuke Miyazawa RT, Abstract Co-Author: Nothing to Disclose

Hironori Nishibori MD, Abstract Co-Author: Nothing to Disclose

Haruo Watanabe MD, Abstract Co-Author: Nothing to Disclose

Mariko Yoshida, Presenter: Nothing to Disclose

Hiroshi Kawada MD, Abstract Co-Author: Nothing to Disclose

Hiroshi Kondo MD, Abstract Co-Author: Nothing to Disclose

Masayuki Kanematsu MD, Abstract Co-Author: Nothing to Disclose

Kyongtae Tyler Bae MD, PhD, Abstract Co-Author: Patent agreement, Covidien AG Patent agreement, Bayer AG Expert Advisory Committee, Bracco Group

To evaluate and compare image quality and radiation in CT of the pancreas acquired using 320-MDCT with and without adaptive iterative dose reduction (AIDR) and 64-MDCT.

This prospective study received institutional review board approval and written informed consent was obtained. A total of 150 consecutive patients (87 men and 63 women; age: 25–94 years; mean age: 65 years), who underwent biphasic (arterial and pancreatic phase) contrast-enhanced CT, were randomized into three groups. The groups included: 320-slice CT with AIDR (group A), 320-slice CT without AIDR (group B) and 64-slice CT without AIDR (group C). Biphasic transaxial, multiplanar reformatted images, and volume-rendered CT angiograms were acquired. CT numbers of abdominal aorta, pancreas, abdominal wall fat tissue, signal-to-noise ratios (SNR), and dose-length product (DLPs) were measured and compared. The CT image quality was also rated by two blinded radiologists.

No significant difference in CT numbers of the abdominal aorta or pancreas was noted between the three groups. Mean DLP (mGy•cm) of the entire patients, those with < 60 kg in body weight and those with > 60 kg were [601, 528 and 719] in group A, [671, 628 and 784] in group B and [1187, 1150, and 1271] in group C, respectively. The data consistently demonstrated lower DLP’s for group A (by 43-54%) and group B (by 38-45%) than those for group C (p < .001). SNRs of the pancreas during the pancreatic phase for group A were comparable with those for group C, but were 39% and 42% higher than those for group B at < 60 kg and > 60 kg, respectively (p < .001). The depiction of pancreatic parenchyma, splanchnic arteries and most of small splanchnic arterial branches was comparable between the three groups, however, the depiction of main pancreatic duct was slightly lower in group B than in group A and C.  

320-slice volumetric pancreatic CT with AIDR markedly reduced patient radiation exposure while the image quality remained comparable with 64-slice helical CT.

320-MDCT with volumetric scan mode combined with iterative reconstruction allowed lower radiation exposure while maintaining a good image quality for contrast-enhanced CT imaging of the pancreas.

Goshima, S, Tsuge, Y, Miyazawa, D, Nishibori, H, Watanabe, H, Yoshida, M, Kawada, H, Kondo, H, Kanematsu, M, Bae, K, Image Quality and Radiation in CT of the Pancreas: Comparison of 320-MDCT with and without Adaptive Iterative Dose Reduction and 64-MDCT.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11004148.html