Transcript Slide 1

Radiological Category: Gastrointestinal
Principal Modality (1): MRI
Principal Modality (2): Angiography
Case Report of patient RE
Submitted by:
Jesse M Proett, MS4
Faculty reviewer:
Sandra Oldham, M.D
Date accepted:
29 August 2007
Presentation for Radiology 4001
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.
Radiological Presentations
Radiological Presentations
Radiological Presentations
Test Your Diagnosis
Which one of the following is your choice for the appropriate diagnosis?
• Hepatocellular Carcinoma
• Hepatic Adenoma
• Hemangioma
• Focal Nodular Hyperplasia
• Hepatic Cysts
• Vascular Abnormality
Findings and Differentials
Findings:
The liver demonstrates a heterogeneous appearance, and there is some nodularity
associated with its contour. Decreased intensity is noted in the left lobe in noncontrast, 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.
Differentials:
• Hepatocellular Carcinoma
• Hepatic Adenoma
• Hemangioma
• Focal Nodular Hyperplasia
• Vascular Abnormality
Radiological Presentations
Radiological Presentations
Radiological Presentations
Discussion
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
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
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
• 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.
Radiological Presentations
Radiological Presentations
Radiological Presentations
Radiological Presentations
Diagnosis
Intrahepatic Arterioportal Fistula (APF)
Diagnosis
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, BuddChiari syndrome, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos
Congenital - typically presents very early in life (neonate – 10yo)
Diagnosis
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
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
Proposed Classification
Type 1
- Small, peripheral, intrahepatic fistulas with minimal physiologic consequences
- Commonly secondary to liver biopsy
- Usually thrombose spontaneously <1mo
- Follow with US or embolize if persistent >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
Radiological Presentations
References
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