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Cystic artery

The cystic artery is the primary arterial supply of the gallbladder and cystic duct. In the majority of individuals, it arises from the right hepatic artery within the hepatocystic (Calot’s) triangle, though variations are common. It may originate from the left hepatic artery, common hepatic artery, gastroduodenal artery, or superior mesenteric artery.

The cystic artery typically divides into superficial and deep branches. The superficial branch supplies the peritoneal surface of the gallbladder, while the deep branch supplies the nonperitoneal surface. Both branches anastomose extensively within the gallbladder wall. Smaller twigs also supply the cystic duct.

Clinically, the cystic artery is of paramount importance during laparoscopic cholecystectomy, where identification and ligation are necessary. Aberrant anatomy is a common cause of bile duct or vascular injury. It is also important in gallbladder ischemia, cholecystitis, and interventional embolization procedures.

Synonyms

  • Arteria cystica

  • Gallbladder artery

  • Artery of Calot’s triangle

Function

  • Provides arterial supply to the gallbladder and cystic duct

  • Maintains gallbladder wall perfusion, essential for bile storage and concentration

  • Anastomoses ensure collateral circulation between superficial and deep branches

MRI Appearance

T1-weighted images:

  • Appears as a thin linear flow void (black lumen) within the hepatocystic triangle

  • Best seen adjacent to gallbladder neck and cystic duct

T2-weighted images:

  • Lumen remains a signal void against surrounding hyperintense bile and intermediate hepatic tissue

  • In acute cholecystitis, perivascular edema may accentuate the artery’s course

STIR:

  • Fat suppression helps outline artery within hepatocystic fat planes

  • Inflammatory changes or edema appear hyperintense

T1 Fat-Saturated (Pre-contrast):

  • Lumen typically shows intermediate signal intensity, standing out against suppressed fat of the hepatocystic triangle

  • Useful for distinguishing artery from adjacent ducts and fat

T1 Fat-Saturated Post-Contrast (Gadolinium):

  • Artery enhances brightly and homogeneously

  • Demonstrates origin and bifurcation into superficial and deep branches

  • Useful in evaluating vascularity in cholecystitis, neoplasms, or variant anatomy

MRA (Magnetic Resonance Angiography):

  • Depicts cystic artery origin, course, and branching pattern

  • Helpful in pre-cholecystectomy planning, especially in patients with aberrant hepatic arterial anatomy

  • Identifies accessory cystic arteries or rare anomalies

CT Appearance

CT Pre-Contrast:

  • Appears as a small linear soft-tissue density near gallbladder neck

  • Difficult to visualize without contrast

CT Post-Contrast:

  • Cystic artery enhances brightly within hepatocystic triangle

  • Branches to gallbladder wall can sometimes be followed with high-resolution imaging

  • Active extravasation may be seen in rare cases of hemobilia or vascular injury

CT Angiography (CTA):

  • Gold standard for detailed non-invasive mapping

  • Clearly shows cystic artery origin (most commonly from right hepatic artery), course, and bifurcation

  • 3D reconstructions highlight variations in Calot’s triangle

  • Essential for surgical planning, vascular injury assessment, and interventional radiology procedures

CT image

Cystic artery CT axial iamge

MRI image

Cystic artery MRI CORONAL anatomy image -img-00000-00000