Table 2.

Diagnostic modalities used for annular pancreas

Case	CT abdomen	Upper GI scopy	MRI abdomen	Others
1	AP with dilated stomach and D2 luminal narrowing	D1 and pangastritis	Not done	Barium meal-abrupt narrowing in D1 with delayed passage of dye
2	AP with dilated stomach with D2 obstruction	Peptic ulcer, D2 narrow	AP and D2 obstruction	Not done
3	Not done	Peptic ulcer, dilated D1, D2-D3 narrow	AP, D2 obstruction, pseudocyst in head, divisum+	MRCP - pancreatic divisum. EUS/FNA s/o pseudocyst
4	D2 narrowing, few LN in HDL	D1 duodenitis, D2 oedema and narrow	Not done	EUS - annular pancreas, FNAC-negative
5	-	Gastric bile reflux gastritis, and a dilated D2	Not done	Barium meal study also confirmed duodenal obstruction
6	AP with dilated stomach	Pangastritis with narrow D2-D3	Not done	Not done

AP: Annular pancreas, D1, D2, D3: Duodenum 1^st, 2^nd and 3^rd parts, respectively, LN: Lymph node, HDL: Hepatoduodenal ligament, EUS: Endoscopic ultrasound, CT: Computed tomography, GI: Gastrointestinal, MRI: Magnetic resonance imaging, MRCP: Magnetic resonance cholangiopancreatography, FNA: Fine-needle aspiration; FNAC: FNA cytology