A recent case study (A Adeyemi et al. J Pediatr 2020; 220: 245-8) provides information on 6 infants with a subsequent diagnosis of biliary atresia who had HIDA scans which reported excretion.

Methods: HIDA scans from 1992-2012 were reviewed from CHOP, this included 223 infants up to 4 months of age.

Key findings:

• While there were six cases with HIDA scans that showed excretion into the bowel, none of these infants had truly normal HIDA scans.
• 4 of the 6 patients had excretion qualified as slight, mild, or subtle and faint.
• 5 of the 6 patients did not have the gallbladder visualized on HIDA.

Commentary:

• HIDA scans are well-known to have a high sensitivity but a low specificity for biliary atresia (even with pretreatment choleretic agents). Liver biopsies have a higher diagnostic accuracy.
• Since biliary atresia is a progressive disease, some excretion on HIDA does not exclude the diagnosis.  Though, age at HIDA was not a significant variable in this small series.

My takes:

• Don’t rely too much on any test, including HIDA scans.  Equivocal findings need to be reported as such.
• Fortunately, MMP-7 has emerged as another quick way with good (not perfect) specificity for biliary atresia.
• Another related caveat is to look carefully at ultrasounds in this age group.  Often a small or retracted gallbladder is overlooked and could be an important clue to the diagnosis of biliary atresia.

Related blog posts:

• Biliary Atresia Biomarkers 2020
• More data, More Nuance with MMP-7
• Blood Test is Better Than a Liver Biopsy for Bilary Atresia
• Predicting Future Liver Disease with GGT Values in Biliary Atresia
• Will We Still Need a Liver Biopsy to Diagnose Biliary Atresia in a Few Years?
• Helpful Review on Biliary Atresia | gutsandgrowth

Rhododendron Flowers (Spring 2020)