Gadopentetate dimeglumine-enhanced MR cholangiopancreatography in infants with cholestasis.
BACKGROUND
Biliary atresia (BA) is a progressive, obliterative cholangiopathy that occurs in neonates with hepatic portoenterostomy the treatment of choice, but early surgery is important for optimum outcomes. MRI, including MR cholangiopancreatography (MRCP) may be a diagnostically useful alternative to US, but the heavily T2-weighted sequences used include not only bile duct signals, but also other heterogeneously high signal intensities from surrounding structures.


OBJECTIVE
To evaluate the effects of gadolinium when used to decrease background signal intensity on T2-weighted MR cholangiopancreatography (MRCP) in infants and to evaluate the qualitative improvement of the depiction of the common bile duct (CBD) for evaluating neonatal cholestasis.


METHODS
Our Institutional Review Board approved this prospective study. MRCP was performed with gadopentetate dimeglumine injection using a 1.5-T scanner. Pre- and postcontrast MRCP images were compared. Forty-nine infants (male:female = 21:28; age 0-12 months, mean 2.3) were included. The final diagnoses were biliary atresia (BA) in 28 cases and non-BA in 21. Quantitative analysis was conducted using region-of-interest measurements of mean signal intensities of the liver, pancreatic head and gallbladder (if defined). Qualitative analysis was performed by four radiologists who subjectively scored image confidence in the presence of CBD on a 4-point scale (0 for definitely absent, 1 for probably absent, 2 for probably present, and 3 for definitely present).


RESULTS
The signal-to-noise ratios were significantly decreased in the liver and pancreatic head after contrast medium enhancement (mean 5.7→4.0 in liver and mean 44.9→12.7 in the pancreatic head; P < 0.0001), and this finding was constant in both the BA and the non-BA group. The mean confidence score in the presence of CBD decreased in the BA group (0.9→0.5; P < 0.0001), but did not change significantly in the non-BA group (2.0→2.1; P = 0.459) after contrast medium enhancement. Both intra- and interobserver agreement was higher after contrast medium enhancement (P = 0.046).


CONCLUSIONS
Gadopentetate dimeglumine-enhanced MRCP increased the diagnostic confidence of absence of the CBD in cholestatic infants with increased intra- and interobserver agreement.
Department of Radiology and Research Institute of Radiological Science, Severance Children's Hospital, Yonsei University, College of Medicine, 250 Seongsanno (134 Sinchon-dong), Seodaemun-gu, Seoul, 120-752, South Korea.
Mi-Jung
MJ
Lee
Myung-Joon
MJ
Kim
Choon-Sik
CS
Yoon
Yong Eun
YE
Chung
Seok Joo
SJ
Han
Hong
H
Koh
D001656:Biliary Atresia / Q000175:diagnosis*; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D002779:Cholestasis / Q000175:diagnosis*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
D003287:Contrast Media; D019786:Gadolinium DTPA