Mi-Jung Lee, Presenter: Nothing to Disclose

Myung-Joon Kim MD, Abstract Co-Author: Nothing to Disclose

Mu Sook Lee MD, Abstract Co-Author: Nothing to Disclose

Choon-Sik Yoon MD, Abstract Co-Author: Nothing to Disclose

Yong Eun Chung MD, Abstract Co-Author: Nothing to Disclose

Kyung Ah Kim MD, Abstract Co-Author: Nothing to Disclose

MRCP can be used to exclude biliary atresia (BA) as the cause of neonatal cholestasis when the common bile duct (CBD) is observed, but it is not always definite. Gadolinium chelate is known to have T2 shortening effect and can darken the area of contrast distribution. So the purpose of this study is to find the benefit of gadolinium on MRCP in pediatric patients including BA.

We retrospectively reviewed MRCP performed in children from January 2007 to October 2008 in 1.5 Tesla scan. Pre-contrast MRCP and post-contrast images with full (0.1mmol/kg) or half dose contrast (Gadopentetate dimeglumine (Gd-DTPA)) injection were compared. Quantitative analysis was conducted using operator-defined region-of-interest measurements of mean signal intensity of the liver, CBD (if defined) and pancreas head area. Qualitative analysis was performed as four radiologists subjectively scored images for depiction of CBD in a 4-point scale. Means of signal intensities, signal- and contrast-to-noise ratio (SNR and CNR) and depiction scores were compared statistically.

Twenty two children (M:F=10:12; age 0-74 months (mean 14.6 and median 3.5)) was involved. Final diagnosis was BA in 8 cases (4 full and 4 half dose) and non-BA in 14 cases (12 full and 2 half dose). SNR was significantly decreased in pancreas head area after contrast injection (mean 27.7 on pre-contrast scan and 12.9 on post-contrast image; p < 0.0001). It was constant regardless of contrast dose or final diagnosis. CNR of CBD to pancreas head area was higher in full dose group than in half dose one (mean 41.2 vs. 27.6; p=0.783). In the qualitative analysis, mean depiction scale was decreased in BA patients after contrast injection (from 1.59 to 1.34; p=0.059).

There is T2 shortening effect of gadolinium on MRCP in both cases with BA or non-BA. Darkening of signal intensity in pancreas head area after contrast enhancement can make higher confidence of the presence or absence of CBD in the patients with neonatal cholestasis. And only half dose contrast injection is sufficient for this effect.

In the patients with neonatal cholestasis, MRCP with gadolinium enhancement can differentiate biliary atresia from non-biliary atresia with higher confidence.

Lee, M, Kim, M, Lee, M, Yoon, C, Chung, Y, Kim, K, T2 Shortening Effect on MR Cholangiopancreatography (MRCP) in Pediatric Patients.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8008744.html