Table 1:

Differential diagnoses for pancreatic arteriovenous malformation

	CT	MRI	Angiography	US
Pancreatic arteriovenous malformation	Multiple discrete intrapancreatic vessels, best demonstrated on early arterial scanning; multiple feeding vessels associated with early portal vein opacification	Cluster of tubular structures demonstrating signal void on T2-weighted imaging	Lesion with racemose vascular network; multiple feeding arteries to the pancreatic lesion with immediate opacification of the portal vein	Nonspecific hypoechoic nodules; mosaic pancreatic color flow pattern; pulsatile portal vein waveforms on Doppler
Hypervascular pancreatic tumor (islet cell tumor)	Solitary hyperattenuating lesion in arterial and venous phase imaging; large lesions show ring-like enhancement	Discrete solitary lesion demonstrating high signal on T2; low signal on T1; variable enhancement, sometimes ring-like	Small to large densely opacified, well defined lesion	Solitary, well marginated, oval/round, homogeneous hypoechoic lesion
Hypervascular metastases	Solitary or multiple discrete masses with peripheral or homogeneous enhancement	Solitary or multiple discrete masses with variable signal intensity; peripheral or homogeneous enhancement	Solitary or multiple discrete hypervascular masses	Solitary or multiple well defined lesions
Intrapancreatic accessory spleen	Round mass with attenuation similar to spleen on all imaging sequences	Round mass with signal characteristics similar to spleen on all imaging sequences	Solitary lesion; may mimic islet cell tumor	Round or oval mass with similar echogenicity to spleen; posterior acoustic enhancement; vascular hilum
Chronic pancreatitis (rare appearance)	Hypervascularity and early arteriovenous shunting with portal vein filling; additional findings of chronic pancreatitis	Pancreas diffusely low in signal on T1 fat-suppressed sequences; decreased and delayed enhancement	Hypervascular mass with early visualization of the portal vein	Heterogeneous increased echogenicity; pancreatic enlargement; focal increased echogenicity; pseudocysts