1. Case Report of patient RE Submitted by:Jesse M Proett, MS4 Faculty reviewer:Sandra Oldham, M.D Date accepted:29 August 2007 Radiological Category:Principal Modality (1): Principal Modality (2): Gastrointestinal Angiography MRI Presentation for Radiology 4001

2. Case History RE is a 62 yo man with cirrhosis and ESLD likely secondary to NASH and portal HTN. He has a MELD score of 18 and is currently on the liver transplant list. On his last appointment he was found to have an elevated AFP of 153.8 (Ref Range <15). He had core needle biopsies of the liver on 5/4/2005 and also in 2001 in Denver. RE also had a jet ski accident in 1992 resulting in a leg fracture and additional traumas in 2002 and 2004 requiring hand and wrist surgery. There was no reported trauma to the liver other than the biopsies.

3. Radiological Presentations

6. Hepatocellular Carcinoma Hepatic Adenoma Hemangioma Focal Nodular Hyperplasia Hepatic Cysts Vascular Abnormality Which one of the following is your choice for the appropriate diagnosis? Test Your Diagnosis

7. The liver demonstrates a heterogeneous appearance, and there is some nodularity associated with its contour. Decreased intensity is noted in the left lobe in non- contrast, dynamic, and delayed images. On the dynamic images there is an area of blush seen near the dome. This is felt to represent an area of increased vascularity. There is no evidence of washout, enhancing capsule, or discrete mass lesion. The portal vein is enlarged measuring 16mm. Hepatocellular Carcinoma Hepatic Adenoma Hemangioma Focal Nodular Hyperplasia Vascular Abnormality Findings: Differentials: Findings and Differentials

8. Radiological Presentations

11. Hepatocellular Carcinoma Lesion must be larger than 3cm Hyperintense appearance in T2W images Intense enhancement in the arterial dominant phase Late washout Presence of capsule Tendency to invade the portal and hepatic veins Rapid growth Hepatic Adenoma MRI characteristics are highly variable Hyperintense on T1 and T2W images due to the presence of fat and/or glycogen Greater enhancement on T2W images with gadolinium is highly suggestive of the diagnosis Gadolinium enhancement is early, after which the lesion becomes isointense Discussion

12. Hemangioma Hypointense in T1W images Hyperintense in T2W images Smooth, well-demarcated borders Ring-like enhancement 1 minute after contrast is given Wash-out, which causes a heterogeneous appearance, and observation of a uniform, thick ring Focal Nodular Hyperplasia They are hypo- or isointense on T1W images Mildly hyper- or isointense on T2W images Rapid enhancement in the early arterial phase Washout in the late phase is observed Central scar tissue shows late enhancement Discussion

13. Vascular Abnormality MRI is not the ideal modality to diagnose vascular abnormalities Angiography is the gold standard for diagnosis. The decreased intensity in the left lobe of the liver through both non-contrast and contrast images does indicate a possible vasculature etiology The area of high intensity during the dynamic phase suggests increased vascularity with no evidence of a discrete mass Hepatic US showed no evidence of abnormal blood flow on 4/29/2005 before his core needle biopsy on 5/4/2005. Discussion

14. A diagnosis could not be made based on the MRI. Further evaluation is needed to rule out malignancy. A lipiodol study was ordered to visualize a possible HCC. Lipiodol is an embolic agent used in angiography that allows us to visualize HCC because the embolic agent stays in the mass. Discussion

15. Radiological Presentations

19. Intrahepatic Arterioportal Fistula (APF) Diagnosis

20. Etiology Acquired Trauma - blunt or penetrating Iatrogenic - interventional hepatic procedures, liver biopsies, percutaneous transhepatic cholangiography, ruptured splanchnic artery aneurysms, transhepatic catheterization of bile ducts Tumors - especially hepatocellular carcinoma Liver Transplant Other - Hemangiomas, cirrhosis, regenerating liver nodules, hepatic abscess, Budd- Chiari syndrome, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos Congenital - typically presents very early in life (neonate – 10yo) Diagnosis

21. Liver biopsy - 52% of the patients who had an arteriogram performed within 1 week following liver biopsy. This rate decreased to 10% if the arteriogram was performed 3 weeks after liver biopsy. These data suggest most small, peripheral, asymptomatic fistulas caused by liver biopsy will disappear spontaneously within 1 month. Trauma - The majority of APFs are due to blunt or penetrating trauma. APFs develop more frequently from penetrating trauma. In some cases the traumatic event can be decades before the presentation of the APF. Cirrhosis - AFPs due to cirrhosis are more commonly peripheral and asymptomatic. Diagnosis

23. Ultrasound - US is a useful tool in screening patients with cirrhosis or those at risk of acquiring APFs. RE did have an US of his abdomen, and at that time there was no mention of an APF. Finding on his US on 4/29/2005 include portal vein 4.5mm with no detectable flow within the main portal vein. MRI - This is not a diagnostic study for the evaluation of APFs, but there are some subtle signs. APFs can induce focal sparing in the diffuse fatty liver through increased non-lipid-rich arterial flow and decreased lipid-rich portal flow. This means that in the area affected by the APF there can be decreased signal which is what we observed on MRI. Much in the same way gadolinium will also be shunted away from the areas affected by the APF. Angiography - This is the gold standard for diagnosing APFs. Contrast material is seen immediately entering the portal circulation. Diagnosis

24. Proposed Classification Type 1 - Small, peripheral, intrahepatic fistulas with minimal physiologic consequences - Commonly secondary to liver biopsy - Usually thrombose spontaneously 1mo and/or become symptomatic Type 2 - Larger, more central fistulas with enough flow to cause elevated portal pressures - Most are secondary to penetrating trauma - Cause portal hypertension and hepatoportal sclerosis and can progress to portal fibrosis - Treat with embolization if possible or surgery for complicated cases Type 3 - Diffuse intrahepatic APFs - Congenital - Cause severe portal hypertension in infancy - Refer to a specialized pediatric hepatobiliary center. Treatment may consist of hepatic artery ligation, embolization, resection, or liver transplantation Diagnosis

25. Radiological Presentations

26. 1. Guzman EA, McCahill LE, Rogers FB. Arterioportal fistulas: introduction of a novel classification with therapeutic implications. J Gastrointest Surg 2006;10:543–550. 2. Bilgili Y,Firat Z, Pamuklar E, et al. Focal liver lesions evaluated by MR imaging. Diagn Interv Radiol 2006; 12:129-135. 3. Bolognesi M, et al. Arterioportal fistulas in patients with liver cirrhosis: usefulness of color doppler US for screening. Radiology 2000; 216:738–743. 4. Choi BI, Lee KH, Han JK, Lee JM, et al. Hepatic arterioportal shunts: dynamic CT and MR features. Kor J Radiol 2002;3:1–15. 5. UpToDate References