*6.3. Cholangiopathy*

An additional and feared complication of arterioportal or arteriosystemic shunts is cholangiopathy. The hepatic artery is the only blood supply to the bile ducts. Therefore, if blood is shunted from the hepatic artery to the portal or systemic veins, the bile ducts have decreased perfusion. In severe cases, this can result in bile duct ischemia/necrosis, biliary strictures, cholangitis, and even liver abscesses (Figure 10) [10,15].

**Figure 10.** Ischemic cholangiopathy in a 36-year-old woman with HHT. Marked dilation of the intrahepatic bile ducts (arrows) and focal stenoses of the biliary tree (arrowheads) are seen on (**a**) coronal T2-weighted SSFSE MR images, (**b**) axial T2-weighted SSFSE MR images, (**c**) coronal MRCP maximum-intensity projection image, and (**d**) coronal T1-weighted gadolinium-enhanced MR image. (SSFSE = single shot fast spin echo, MRCP = magnetic resonance cholangiopancreatography).

#### **7. Summary and Future Direction**

Hepatic VMs are common in patients with HHT, although a majority of them are asymptomatic. Arterial-systemic shunting between the hepatic artery and hepatic vein contributes to HOCF, a major cause of morbidity and mortality for HHT patients. Arterial-portal shunting can lead to portal hypertension. Liver-specific abnormalities include pseudocirrhosis, FNH, and ischemic cholangiopathy.

Non-invasive imaging with US, CT, and MRI plays a valuable role in assessing the hepatic manifestations of HHT. US is the preferred initial screening modality for liver VMs. All three methods can be useful for detecting and distinguishing the type of shunting that is present as well as for the detection of focal lesions as well as the physiologic consequences of portal hypertension.

Because the severity and type of liver shunting is an important determinant of the clinical presentation, particularly the development of HOCF, there is considerable interest in determining whether imaging assessment of hepatic VMs can help predict treatment response in patients undergoing anti-angiogenic therapy. As described above, quantitative assessment of flow and vascular morphology using US or MRI has the potential to help understand the role of the liver in determining the clinical response to these novel therapies.

**Author Contributions:** All authors contributed significantly to the creation of this manuscript, including drafting of text, preparing figures, and editing of manuscript. All authors have read and agreed to the published version of the manuscript.

**Funding:** No specific funding was provided for this manuscript.

**Conflicts of Interest:** Authors declare no relevant conflicts of interest. MAO has received travel support from General Electric, but unrelated to the topic and content of this manuscript.
