RE: Afferent Loop Syndrome: A Rare Clinical Condition Diagnosed with Magnetic Resonance Cholangiopancreatography.

Dear Editor:

We read with great interest the pictorial essay by Dusunceli Atman et al. (1), entitled "MRI findings of intrinsic and extrinsic duodenal abnormalities and variations" that was recently published in the Korean Journal of Radiology, November 2015. The authors have described duodenal abnormalities and variations in a didactic, well-designed and well-illustrated manner. However, we would like to point out a unique duodenal abnormality that was omitted in this article i,e., afferent loop syndrome (ALS). The ALS corresponds to an acute or chronic obstruction of the afferent loop following a gastrectomy operation with gastrojejunal anastomosis (2). Afferent loop is the duodenal stump into which the biliary and the pancreatic secretions are drained. In cases of anastomic ulcer, adhesions, mass lesions etc., the drainage of the secretions is obstructed. The back pressure from the dilated afferent loop can cause biliary dilatation, gallbladder dilatation and acute pancreatitis (3). Magnetic resonance cholangiopancreatography is a useful imaging modality to understand and visualise the pancreaticobiliary anatomy and abnormalities; however, the diagnosis of acute cases is rare.