Pancreatic cancer, autoimmune or chronic pancreatitis, beyond tissue diagnosis: Collateral imaging and clinical characteristics may differentiate them

Table 1 Radiological differences in pancreatic masses

Imaging studio	AIP	MFCP	PDAC
Ultrasound
Conventional	Hypoechoic	Hypoechoic	Hypoechoic
CEUS/CE-EUS	Homogeneous enhancement	Homogeneous enhancement	No enhancement
Eltasography by EUS	Predominantly blue heterogeneous pattern	Heterogeneous pattern with a predominance of green color and blue stippling	Heterogeneous pattern with a predominance of blue color and green stippling
CT
Simple	Hypodense; peripheral halo	Hypodense Intraparenchymal calcifications or within the pancreatic duct	Hypodense; parenchymal atrophy
Contrasted	Hyperattenuation (compared to the spleen) in the portal venous phase; presence of extrapancreatic involvement	Heterogeneous hyperattenuation; absence of extrapancreatic involvement	No enhancement; vascular invasion
Perfusion		Low BF and BV values compared to normal pancreatic parenchyma but higher than PDAC	Low BF and BV values compared to MFCP
Dual-energy			Appears as a hypodense mass in low voltage imaging (especially during portal phase); in the iodine mapping the mass shows enhancement
MRI
T1	Hypointense; hypointense peripheral halo	Hypointense	Hypointense
T2	Hyperintense; hypointense peripheral halo	Hyperintense: Early stage; hypointense: Advanced stage	Hyper/hypointense
DWI	Hyperintense	Hyperintense	Hyperintense
ADC	Higher hypointensity than MFCP and PDAC	Hypointense	Hypointense
Elastography	Higher stiffness compared to normal parenchyma but lesser compared to PDAC; multiple scattered lesions		Higher stiffness compared to AIP; single, isolated nodular lesions

ADC: Apparent diffusion coefficient; AIP: Autoimmune pancreatitis; BF: Blood flow; BV: Blood volume; CEUS: Contrast-enhanced ultrasound; CE-EUS: Contrast-enhanced endoscopic ultrasound; EUS: Endoscopic ultrasound; CT: Computed tomography; DWI: Diffusion sequence; MFCP: Mass-forming chronic pancreatitis; PDAC: Pancreatic ductal adenocarcinoma; MRI: Magnetic resonance.