A 2 month baby presents with history of jaundice, turmeric colored urine and pale stools since bih. Examination reveals liver span of 10 cms, firm in consistency and spleen of 3 cms. The most specific investigation for establishing the diagnosis would be:
Liver function tests
Ultrasound abdomen
Peroperative cholangiogram
Liver biopsy
All patients suspected of having biliary atresia should undergo exploratory laprotomy and direct cholangiography to determine the presence and site of obstruction. Ref: Kliegman, Behrman, Jenson, Stanton (2008), Chapter 353, "Cholestasis", In the book, "NELSON TEXTBOOK OF PEDIATRICS", Volume 2, 18th Edition, New Delhi, Page 1673; Harrison's Internal Medicine, 18th Edition, Page 2624.