Early detection of gallbladder cancer: Current status and future perspectives

Table 2 Summary of various imaging modalities for identifying malignant gallbladder pathology

Imaging modalities	Features suggestive of malignancy	References
USG	Localized thickening, mass and a stone GB lumen with localized thickening	[50]
	Mass along with thickening	[51]
	Polypoidal mass with wall thickening > 1 cm, hypoechogenicity, internal hypoechoic foci	[52]
	Loss of layered structure and enhancement of wall	[53]
	Solitary gallstone, displaced stone, intraluminal mass, GB-replacing or invasive mass, discontinuity of the mucosal echo	[54]
CEUS	Arterial phase inhomogeneous hyperenhancement, venous phase hypoenhancement and disruption of GB wall layer structure	[55]
	Rapid GB wall blood flow and the irregularity of color signal patterns on doppler imaging, and heterogeneous enhancement in the venous phase, focal thickening, discontinuity and irregularity of the innermost hyperechoic layer and irregular or disrupted GB wall layer structure	[56]
	Differences in enhancement direction, vascular morphology, serous layer continuity, wash-out time and mural layering in the venous phase	[57]
	An irregular shape, branched intralesional vessels, and hypo-enhancement in the late phase	[58]
	Homogeneous enhancement in the arterial phase, followed by interrupted inner layer, early washout (≤ 40 seconds), and wall thickness > 1.6 cm	[59]
CECT	The thicknesses of the inner and outer layers (“thick” enhancing inner layer > or = 2.6 mm, “thin” outer layer < or = 3.4 mm), strong enhancement of the inner wall, Irregular contour GB wall, layering pattern - two-layer pattern with a strongly enhancing thick inner layer and weakly enhancing or nonenhancing outer layer and the one-layer pattern with a heterogeneously enhancing thick layer	[60]
	Wall irregularity, focal wall thickening, discontinuous mucosa, submucosal edema, polypoid mass, direct invasion to adjacent organ, biliary obstruction, regional and paraaortic lymphadenopathy and distant metastasis	[61]
	The thickened GB wall with one-layer heterogeneous enhancement (type 1)
	Mass replacing GB, diffuse/focal GB wall thickening and polypoidal mass, associated cholelithiasis, liver infiltration, intra hepatic biliary dilatation, liver metastases, portal vein invasion, antroduodenal and hepatic flexure involvement	[62]
	Heterogeneous peripheral and central enhancement in arterial phase	[63]
MRI	Heterogeneous enhancement, indistinct interface with the liver, and diffusion restriction
	T2 moderate hyperintensity of the thickened wall, papillary appearance, and diffusion restriction	[44]
	Discontinuous enhancing mucosal line, earlier enhancement of wall, diffusion restriction, lower mean ADC in malignant wall	[64]
	Diffusion restriction	[65]
	Low ADC and diffusion restriction	[66]
	Diffusion-weighted examination with a high b value	[67]
PET Scan	Higher SUV uptake	[68]
	Delayed uptake in dual phase PET

ADC: Apparent diffusion coefficient; MRI: Magnetic resonance imaging; CECT: Contrast-enhanced computed tomography; USG: Ultrasonography; CEUS: Contrast-enhanced ultrasound; PET: Positron emission tomography; SUV: Standardized uptake value; GB: Gallbladder.