Imaging Evaluation of the Living Liver Donor: A Systems-Based Approach

Liver transplant is the definitive treatment of end-stage liver disease and early hepatocellular carcinoma. The number of liver transplant surgeries done is highly affected by the number and availability of deceased donor organs. Living donor liver transplantation has emerged as an alternative source of donors, increasing the availability of organs for transplant. Many factors must be considered when choosing living donor candidates to maintain a high level of donor safety and organ survival. To that end, potential donors undergo a rigorous pre-donation workup.

Extramedullary hematopoiesis (EMH) in the liver allograft presenting with a mass-like lesion

This is a rare case of extramedullary hematopoiesis (EMH) presenting as a mass-like lesion in liver allograft. Our patient was a 57-year-old woman who had undergone liver transplantation due to hepatic epithelioid hemangioendothelioma. She presented with an ill-defined hypoechoic lesion on ultrasound which showed features of focal EMH on pathologic examinations. While transient intrahepatic hematopoiesis has been reported in liver transplant patients, focal EMH mass lesion is a rarely encountered phenomenon. Therefore, focal EMH may need to be considered as a differential diagnosis when encountering a mass in post liver transplant patients.

Comparison of Clinical and Radiologic Findings Between Perforated and Non-Perforated Choledochal Cysts in Children

OBJECTIVE

To compare the clinical and radiologic findings between perforated and non-perforated choledochal cysts in children.

MATERIALS AND METHODS

Fourteen patients (mean age ± standard deviation, 1.7 ± 1.2 years) with perforated choledochal cysts (perforated group) and 204 patients (3.6 ± 3.8 years) with non-perforated choledochal cysts (non-perforated group) were included between 2000 and 2019. All patients underwent choledochal cyst excision after ultrasound, CT, or MR cholangiopancreatography. Relevant data including demographics, clinical symptoms, laboratory findings, imaging findings, and outcomes were analyzed. Statistical differences were compared using the Mann-Whitney U test and Fisher's exact test.

RESULTS

Choledochal cyst perforation occurred only in children under the age of 4 years. Acute symptoms, including fever (p < 0.001), were more common in the perforated group than in the non-perforated group. High levels of white blood cells (p = 0.004), C-reactive protein (p < 0.001), and serum amylase (p = 0.002), and low levels of albumin (p < 0.001) were significantly associated with the perforated group. All 14 patients with perforated choledochal cysts had ascites, whereas only 16% (33/204) of patients in the non-perforated group had ascites (p < 0.001). In the subgroup of patients who had ascites, a large amount of ascites (p = 0.001), increase in the amount of ascites in a short time (p < 0.001), complex ascites (p < 0.001), and perihepatic pseudocysts (p < 0.001) were more common in the perforated group than in the non-perforated group.

CONCLUSION

Children with perforated choledochal cysts have characteristic clinical and radiologic findings compared to those with non-perforated choledochal cysts. In young children with choledochal cysts, perforation should be differentiated in cases with acute symptoms, laboratory abnormalities, and characteristic ascites findings.

Haemobilia secondary to an arterio-biliary fistula: A rare complication of intra-operative microwave ablation of hepatocellular carcinoma

A rare case of arterio-biliary fistula and haemobilia complicating intra-operative microwave ablation of hepatocellular carcinoma in a 58-year-old woman with cirrhosis.

Advanced hepatic vasculobiliary imaging segmentation and 3D reconstruction as an aid in the surgical management of high biliary stenosis

BACKGROUND

Three-dimensional (3D) models are increasingly used to help surgeons, guiding them through the complex hepatic vasculobiliary anatomy. The biliary tract is a relatively untapped territory with only a few case reports described in medical literature. Our aim is to present an innovative 3D reconstruction methodology for biliary imaging and surgical planning, applied to a case of iatrogenic biliary stricture, with fusion of segmented CT and MRI images.

CASE PRESENTATION

A selected case of Bismuth type III iatrogenic biliary stenosis for 3D planning. CT and MR studies were acquired with dedicated protocols for segmentation. Two radiologists performed segmentation and 3D model post-processing, fusing both imaging techniques to faithfully render the anatomical structures. Measurements of anatomical landmarks were taken in both the CT/MRI and the 3D model to assure its accuracy and differences in measurement were calculated. The 3D model replicates anatomical structures and pathology with high accuracy, with only 2.2% variation between STL, CT and MRI measurements. The model was discussed with the surgical team and used in the surgical planning, improving confidence in this delicate procedure, due to the detailed prior knowledge of the patient's anatomy.

CONCLUSION

Three-dimensional reconstructions are a rapidly growing area of research with a significant impact in the personalized and precision medicine. The construction of 3D models that combine vascular and biliary anatomy, using different imaging techniques, respectively CT and MRI, will predictably contribute to a more rigorous planning of complex liver surgeries.

Budd-Chiari Syndrome and hepatic regenerative nodules: Magnetic resonance findings with emphasis of hepatobiliary phase

Budd-Chiari syndrome (BCS) is a disorder with numerous causes that is a result of hepatic outflow obstruction, in the absence of right heart failure or constrictive pericarditis. Acute Budd-Chiari syndrome is uncommon and clinically characterized by ascites, hepatomegaly, and hepatic insufficiency. In the majority of cases, patients present with chronic BCS, showing a dysmorphic liver disease with variable fibrosis deposition. In chronic Budd-Chiari syndrome, hepatocellular carcinoma (HCC) and benign regenerative nodules (called large regenerative nodules or FNH-like lesions) have been described in the literature. Very few studies have reported magnetic resonance imaging (MRI) findings about these nodules, using hepatobiliary contrast medium. The aim of our review is to describe the magnetic resonance imaging findings of hepatic regenerative nodules in BCS, with emphasis on the hepatobiliary phase, and to compare the imaging features of benign nodules with those of HCC.

Synthesis, in vitro and in vivo small-animal SPECT evaluation of novel technetium labeled bile acid analogues to study (altered) hepatic transporter function

INTRODUCTION

Hepatobiliary transport mechanisms are crucial for the excretion of substrate toxic compounds. Drugs can inhibit these transporters, which can lead to drug-drug interactions causing toxicity. Therefore, it is important to assess this early during the development of new drug candidates. The aim of the current study is the (radio)synthesis, in vitro and in vivo evaluation of a technetium labeled chenodeoxycholic and cholic acid analogue: [(99m)Tc]-DTPA-CDCA and [(99m)]Tc-DTPA-CA, respectively, as biomarker for disturbed transporter functionality.

METHODS

[99mTc]-DTPA-CDCA([(99m)Tc]-3a) and [99mTc]-DTPA-CA ([(99m)Tc]-3b) were synthesized and evaluated in vitro and in vivo. Uptake of both tracers was investigated in NTCP, OCT1, OATP1B1, OATP1B3 transfected cell lines. Km and Vmax values were determined and compared to [(99m)Tc]-mebrofenin ([(99m)Tc]-MEB). Efflux was investigated by means of CTRL, MRP2 and BSEP transfected inside-out vesicles. Metabolite analysis was performed using pooled human liver S9. Wild type (n=3) and rifampicin treated (n=3) mice were intravenously injected with 37MBq of tracer. After dynamic small-animal SPECT and short CT acquisitions, time-activity curves of heart, liver, gallbladder and intestines were obtained.

RESULTS

We demonstrated that OATP1B1 and OATP1B3 are the involved uptake transporters of both compounds. Both tracers show a higher affinity compared to [(99m)Tc]-MEB, but are in a similar range as endogenous bile acids for OATP1B1 and OATP1B3. [(99m)Tc]-3a shows higher affinities compared to [(99m)Tc]-3b. Vmax values were lower compared to [(99m)Tc]-MEB, but in the same range as endogenous bile acids. MRP2 was identified as efflux transporter. Less than 7% of both radiotracers was metabolized in the liver. In vitro results were confirmed by in vivo results. Uptake in the liver and efflux to gallbladder + intestines and urinary bladder of both tracers was observed. Transport was inhibited by rifampicin.

CONCLUSION

The involved transporters were identified; both tracers are taken up in the hepatocytes by OATP1B1 andOATP1B3 with Km and Vmax values in the same range as endogenous bile acids and are secreted into bile canaliculi via MRP2. Dynamic small-animal SPECT imaging can be a useful noninvasive method of visualizing and quantifying hepatobiliary transporter functionality and disturbances thereof in vivo, which could predict drug pharmacokinetics.

Congenital bilobed gallbladder with phrygian cap presenting as calculus cholecystitis

The incidence of congenital bilobed gall bladder is 1 in 3000 to 4000. A Phrygian cap is a congenital abnormality of the gallbladder with an incidence of 4%. Preferred mode of diagnosis for Phrygian cap is cholescintigraphy and multi phase MRI, as Ultrasonography and CT are not always conclusive. The estimated prevalence of gallstone disease in India has been reported as 2% to 29%. A case of bilobed gall bladder with Phrygian cap in both the lobes and pigment gallstone in one of the lobes presenting as calculus cholecystitis is reported for its rarity and difficulty in arriving at correct preoperaive diagnosis.