Magnetic resonance imaging and diseases of the liver and biliary tract. Part 2. Magnetic resonance cholangiography and angiography and conclusions

A rare variation of celiac trunk and hepatic artery complicating pancreaticoduodenectomy: A case report and literature review

RATIONALE

Anatomical variations of the celiac trunk and the hepatic artery are of considerable importance in hepatopancreatobiliary surgery, liver transplants, and radiological abdominal interventions.

PATIENT CONCERNS

Here, we report a 57-year-old man with 2 weeks of painless progressive jaundice. Preoperative imaging and cytology brush results suggested an ampullary tumor and common hepatic artery anomaly (CTA) was reported. The patient underwent pancreaticoduodenectomy (PD). Intraoperatively, the CHA and gastroduodenal artery (GDA) were abnormal. The CHA emerged from the superior mesenteric artery (SMA). Computer tomography angiography (CTA) was performed postoperatively; surprisingly, the left gastric artery (LGA) and splenic artery (SA) arising from the anterior wall of the abdominal aorta replaced the normal structure of the celiac trunk, and an accessory left hepatic artery (LHA) emerged from the LGA.

DIAGNOSES

The patient was diagnosed with cholangiocarcinoma and accompanying extremely rare variation of celiac trunk and hepatic artery.

INTERVENTIONS AND OUTCOMES

The patient underwent PD and had an uneventful postoperative evolution. There was no recurrence of the tumor and with normal liver function during the 10-month follow-up.

INTERVENTIONS

The patient underwent PD and had an uneventful postoperative evolution.

OUTCOMES

There was no recurrence of the tumor and with normal liver function during the 10-month follow-up.

LESSONS

Surgeons must keep in mind that arterial variation may be present in the vascular structures intraoperatively, even if it was not revealed in preoperative imaging. The preoperative identification of arterial variation and its relationship with the tumor is necessary to avoid intraoperative vascular injury and complications after surgery.

Ischemic-type biliary lesions after ortothopic liver transplantation: diagnosis with magnetic resonance cholangiography

PURPOSE

To determine the accuracy of magnetic resonance (MR) cholangiography for detection of ischemic-type biliary lesions (ITBL) following orthotropic liver transplantation (OLT).

MATERIALS AND METHODS

MR cholangiography was performed in 16 patients with established diagnosis of ITBL following OLT. Two blinded observers reviewed all images in consensus and recorded diagnostic features including presence of intrahepatic and extrahepatic biliary strictures, dilatations, beading, pruning, and filling defects. Sensitivity, specificity, positive predictive value, and accuracy of MR cholangiography were calculated. Final diagnosis was established at endoscopic retrograde cholangiography.

RESULTS

MR cholangiography proved to be a valuable tool for the detection of stenoses and dilatations in patients with ITBL following OLT. Sensitivity of the different diagnostic features ranged between 71% and 100%, specificity between 50% and 100%, accuracy between 81% and 100%, and positive predictive value between 87% and 100%.

CONCLUSION

MR cholangiography proved to be an accurate imaging technique to noninvasively detect biliary complications in patients with ITBL after OLT.

Gadoxetate Acid-Enhanced MR Imaging for HCC: A Review for Clinicians

Hepatocellular carcinoma (HCC) is increasingly being detected at an earlier stage, owing to the screening programs and regular imaging follow-up in high-risk populations. Small HCCs still pose diagnostic challenges on imaging due to decreased sensitivity and increased frequency of atypical features. Differentiating early HCC from premalignant or benign nodules is important as management differs and has implications on both the quality of life and the overall survival for the patients. Gadoxetate acid (Gd-EOB-DTPA, Primovist(®), Bayer Schering Pharma) is a relatively new, safe and well-tolerated liver-specific contrast agent for magnetic resonance (MR) imaging of the liver that has combined perfusion- and hepatocyte-specific properties, allowing for the acquisition of both dynamic and hepatobiliary phase images. Its high biliary uptake and excretion improves lesion detection and characterization by increasing liver-to-lesion conspicuity in the added hepatobiliary phase imaging. To date, gadoxetate acid-enhanced MRI has been mostly shown to be superior to unenhanced MRI, computed tomography, and other types of contrast agents in the detection and characterization of liver lesions. This review article focuses on the evolving role of gadoxetate acid in the characterization of HCC, differentiating it from other mimickers of HCC.

Variant hepatic arterial anatomy revisited: digital subtraction angiography performed in 600 patients

PURPOSE

To evaluate and describe the prevalence of hepatic arterial variants seen at digital subtraction angiography in a large series of patients.

MATERIALS AND METHODS

Data were collected prospectively by using an arterial anatomy database questionnaire that was completed at the time each visceral angiographic examination was performed from May 1996 to October 2000.

RESULTS

Six hundred patients underwent at least one visceral angiographic examination at one institution during the study period. Three hundred sixty-eight (61.3%) patients had the standard hepatic arterial anatomy. One hundred nineteen (19.8%) patients had variant left hepatic arteries (LHAs), and 89 (14.8%) had variant right hepatic arteries (RHAs). Twenty-eight (4.7%) patients had a variant anatomy involving both the LHA and the RHA. Twenty-four (4.0%) patients had a variant origin of the common hepatic artery (CHA) arising from either the superior mesenteric artery (SMA) or the aorta. In two patients, the proper hepatic artery (PHA) was the first branch of the SMA and the gastroduodenal artery (GDA) was a branch of the celiac axis. Double hepatic arteries were seen in 22 (3.7%) patients. Trifurcation or quadrifurcation of the GDA was seen in 50 (8.3%) patients, and the GDA originated distal to one hepatic artery in 25 (4.2%) patients in whom both hepatic arteries originated from the CHA.

CONCLUSION

A replaced LHA was less common than has been previously reported, and in two cases, the PHA arose from the SMA. Digital subtraction visceral angiographic results are comparable to results of seminal angiographic studies in which the cut-film technique was used.

Current awareness in NMR in biomedicine

In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of NMR in biomedicine. Each bibliography is divided into 9 sections: 1 Books, Reviews ' Symposia; 2 General; 3 Technology; 4 Brain and Nerves; 5 Neuropathology; 6 Cancer; 7 Cardiac, Vascular and Respiratory Systems; 8 Liver, Kidney and Other Organs; 9 Muscle and Orthopaedic. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.