Contrast‐enhanced magnetic resonance cholangiography using mangafodipir compared with standard T2W MRC sequences: A pictorial essay

Abstract

, a manganese-containing hepatobiliary contrast agent, is excreted in bile. We review the principles and practice of a contrast-enhanced MRC technique using mangafodipir and compare it with standard T2-weighted magnetic resonance cholangiography (MRC) sequences. Potential applications include the evaluation of leaks and strictures; the assessment of drainage in normal, surgically by-passed, stented and obstructed biliary systems; the diagnosis of cholecystitis; and the evaluation of normal and variant biliary anatomy. THE CURRENT PRACTICE of magnetic resonance cholangiography (MRC) relies on multi-planar thick and thin slice heavily T2-weighted (T2W) fast spin-echo techniques. These MR hydrographic sequences, while demonstrating anatomy, have a limited ability to demonstrate function.Mangafodipir trisodium (Teslascan™, Nycomed Amersham, Oslo, Norway) is an MR contrast agent that contains the paramagnetic metal, manganese (Mn 2ϩ ), which shortens the T1 relaxation time of neighboring protons, providing a positive contrast effect on T1-weighted (T1W) sequences. The manganese is bound to DPDP, a vitamin B6 analogue. Following intravenous injection, the manganese is removed from its DPDP ligand. The manganese binds to plasma proteins and is rapidly cleared from the blood. Seventy to 80% of the manganese is taken up by normal hepatocytes and the liver parenchyma becomes hyperintense on T1W sequences (1-3). The manganese is then transported into the bile, which also becomes hyperintense. A potential therefore exists to use this agent as a positive biliary magnetic resonance imaging (MRI) contrast agent on a T1W sequence.We aimed to demonstrate potential functional applications of a contrast-enhanced MRC technique (CE-MRC) using mangafodipir. IMAGING TECHNIQUE Contrast AdministrationThe standard recommended dose of mangafodipir is 0.005 mmol/kg (0.5 mL/kg). For the average 70 kg patient, this usually involves the slow intravenous administration of 35 mL of mangafodipir (0.35 mmol), followed by 20 mL of saline. Imaging ProtocolOur current MRC protocol is based on a 1.5-T Siemens Symphony (Siemens Medical Systems, Erlangen, Germany) using a phased array coil. Our standard MRC protocol involves initial axial and coronal true fast imaging with steady state precession (FISP) sequences that are performed to localize the hepatobiliary tree. Coronal and coronal oblique thick slab MRC T2 TSE (4500/950/50 mm slab/512 matrix) and thin slice half-Fourier acquisition single-shot turbo spin-echo (HASTE) (ϱ/90 effective/4-mm slices/256 ϫ 512 matrix) MRC sequences are then performed. In most instances CE-MRC is not performed, and we would proceed to CE-MRC in less than 10% of cases.Without moving the patient, mangafodipir is administered as described above. Axial two-dimensional T1W sequences are performed at 10-minute intervals until there is adequate opacification of the biliary tree (typically 20 -30 minutes). At this time a three-dimensional coronal T1W gradient sequence (TR 6.2/TE 2.24/ 15°/32 partitions/effective thickness 1.8/f...

Usefulness of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance cholangiography for detecting mucin retention in bile ducts: a rare intraductal papillary mucinous neoplasm of the bile duct

“…Therefore, conventional MRCP scans should be acquired before EOB is excreted into the biliary tree. Furthermore, the poor mixing of EOB and existing bile may produce pseudo-fi lling defects, 10 and true fi lling defects may be masked if the bile duct is completely fi lled with contrast material. This is a pitfall similar to the one that occurs during ERCP owing to overfi lling or superimposition of contrast medium.…”

Biliary MR Imaging with Gd-EOB-DTPA and Its Clinical Applications

“…Susceptibility artifacts created by the metallic stent occur with all MR imaging sequences (44,45). Despite the susceptibility artifacts, Gd-EOB-DTPA-enhanced MR cholangiography, unlike conventional MR cholangiography, allows assessment of stent patency by means of direct visualization of hepatocyte-specific contrast material above and below the stent (Fig 16) (5). wise, by using Gd-EOB-DTPA-enhanced MR cholangiography, comprehensive information on the patency of biliary-enteric anastomoses is obtained (Fig 15) (6,10).…”

“…Delayed passage of bile through the ampulla of Vater might be determined by observing delayed passage or no passage of contrast material in the ampulla of Vater on images usually obtained more than 0.5-1 hour after intravenous injection of Gd-EOB-DTPA. In addition, Gd-EOB-DTPA-enhanced MR cholangiography can be helpful in excluding the possibility of sphincter of Oddi dysfunction by demonstrating normal passage of contrast material in the bile ducts on images obtained after a 20-30-minute delay in patients clinically suspected to have sphincter of Oddi dysfunction (Fig 18) (5,6,16).…”

“…Most previous studies that characterized the use of hepatocyte-specific MR imaging contrast agents have been limited to the detection and characterization of focal liver lesions. Also, few studies have evaluated the use of MR cholangiography with Mn-DPDP (also termed functional MR cholangiography or contrast-enhanced MR cholangiography) as an alternative to conventional T2-weighted MR cholangiography in evaluation of the biliary tree (3)(4)(5)(6)(7)(8)(9)(10).…”

Non-invasive detection of biliary leaks using Gd-EOB-DTPA-enhanced MR cholangiography: comparison with T2-weighted MR cholangiography

“…The current algorithm for searching for an extravasation of bile is to perform abdominal ultrasound and, if the findings are non-diagnostic, to perform T2-weighted (T2w) MRC, which highlights the biliary tree [7]. The accuracy rate of diagnosis and localisation of an extravasation of bile by T2w-MRC is within the range 70–74 % [8]. T1-weighted (T1w) contrast-enhanced MRC (CE-MRC) using hepatobiliary contrast agents such as gadobenate dimeglumine (Gd-BOPTA) and gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA) is a recently emerged technique with promising results with respect to its ability to visualise non-dilated bile ducts and biliary leaks [5–9].…”