Gadoxetic acid-enhanced T1-weighted MR cholangiography in primary sclerosing cholangitis

Abstract

Purpose: To investigate the value of gadoxetic acid-enhanced three-dimensional T1-weighted MR cholangiography (T1w-MRC) in comparison to three-dimensional T2-weighted MR cholangiopancreaticography (T2w-MRCP) in patients with primary sclerosing cholangitis (PSC).

Materials and methods: Thirty-four MR exams in 29 patients (46.0 ± 16.1 years; 19 men, 10 women) scanned within a 14-month period were retrospectively included. Two abdominal radiologists independently evaluated image quality regarding image contrast, image quality degradation due to artifacts, and visualization quality of ducts. The order of biliary tree branches that were visualized and reader preference toward each method were recorded. Helpfulness of T1w-MRC was scored in consensus. Confirmatory endoscopic retrograde cholangiopancreaticography (ERCP) performed within 3 months of the MR examination was available in 8 patients.

Results: Image quality of T1w-MRC and T2w-MRCP was graded good to excellent in all cases. There were advantages for both T1w-MRC (functional information, less degradation due to artifacts) and T2w-MRCP (higher order of visualized branches, better branch depiction). Both readers showed preference for T2w-MRCP; however, both readers found gadoxetic acid-enhanced T1w-MRC helpful in the majority of cases.

Conclusion: Gadoxetic acid-enhanced T1w-MRC is complementary to, but should not replace, T2w-MRCP. T1w-MRC is a useful adjunct to T2w-MRCP for morphologic evaluation and provides additional diagnostic information.

Figure 1

33-year old man with ulcerative colitis and suspected primary sclerosing cholangitis. Comparison of ERCP (A), T2w MRCP MIP (B), and gadoxetic-enhanced T1w MRC MIP (C) underlines the similarity of results obtainable with all three methods. Note the decreased signal intensity of the left hepatic duct in the T1w MRC image (C, white arrows). This pseudo-stenosis is created due to layering of the contrast agent with the patient being in supine position. This finding underlines a) the necessity to read the axial images as opposed to MIP reformats alone and b) the complementary nature of T1w MRC and T2w MRCP.

Figure 2

26-year-old man with ulcerative colitis, primary sclerosing cholangitis (PSC), and elevated liver function tests. ERCP (A), T2w MRCP MIP (B), and gadoxetic acid-enhanced T1w MRC MIP (C, inset: axial MIP) depict the extent of the disease with the beaded appearance of multiple stenoses and segmental dilatations. Both T2w MRCP and T2w MRC were graded with matching good image quality (scale level “2”) and some deterioration due to artifacts (scale level “2”).

Figure 3

29 year-old female with known PSC and ulcerative colitis. A multitude of strictures is depicted by T2w MRCP MIP (B) and ERCP (A). Gadoxetic acid-enhanced T1w MRC MIP (C) depicts the central ducts equally well. The MIP display in (C, inset: axial MIP) reveal the detail seen in the stack of axial images which revealed multiple stenotic and dilated segments to the 3^rd (reader 1) or 4^th (reader 2) branch.

Figure 4

28 year-old woman with PSC. Pruned intrahepatic biliary tree with multiple ductal irregularities. Clearly, ERCP (A) and T2w MRCP MIP (B) are able to depict the biliary tree. In contrast, gadoxetic acid-enhanced T1w MRC MIP (C) does not provide a central cholangiogram at 20 min after injection. Instead, innumerable hyperintense foci of the liver may represent tiny peripheral bile ducts or biliary lakes. Despite the lack of a central T1w MR cholangiogram, the study was graded “helpful (1)” during the evaluation since functional information on the excretion to the extrahepatic ducts is available.

Figure 5

65 year-old man status post liver transplantation due to PSC presenting with elevated LFT’s to rule out recurrent disease. Next to the depiction of the main biliary ducts with both techniques (A: T2w MRCP MIP, B: T1w MRC MIP), T1w MRC clearly proofs the patency of the choledochojejunostomy.