Portal vein abnormalities: an imaging review

Exosomal delivery of cannabinoids against cancer

Exosomes are extracellular vesicles (EVs) originating from endosomes that play a role in cellular communication. These vesicles which mimic the parental cells that release them are promising candidates for targeted drug delivery and therapeutic applications against cancer because of their favorable biocompatibility, specific targeting, low toxicity, and immunogenicity. Currently, Delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD) and other cannabinoids (e.g., CBG, THCV, CBC), are being explored for their anticancer and anti-proliferative properties. Several mechanisms, including cell cycle arrest, proliferation inhibition, activation of autophagy and apoptosis, inhibition of adhesion, metastasis, and angiogenesis have been proposed for their anticancer activity. EVs could be engineered as cannabinoid delivery systems for tumor-specificity leading to superior anticancer effects. This review discusses current techniques for EV isolation from various sources, characterization and strategies to load them with cannabinoids. More extensively, we culminate information available on different sources of EVs that have anticancer activity, mechanism of action of cannabinoids against various wild type and resistant tumors and role of CBD in histone modifications and cancer epigenetics. We have also enumerated the role of EVs containing cannabinoids against various tumors and in chemotherapy induced neuropathic pain.

Percutaneous radiological interventions of the portal vein: a comprehensive review

The portal vein is the largest vessel supplying the liver. A number of radiological interventions are performed through the portal vein, namely for primary pathologies of the portal vein, for inducing liver hypertrophy or to treat the sequelae of portal hypertension among others. The routes used include direct transhepatic, transjugular, and, uncommonly, trans-splenic and through subcutaneous varices. Portal vein embolization and transjugular intrahepatic portosystemic shunt are among the most common portal vein interventions that are performed to induce hypertrophy of the future liver remnant and to treat complications of portal hypertension, respectively. Other interventions include transhepatic obliteration of varices and shunts, portal vein thrombolysis, portal vein recanalization, pancreatic islet cell transplantation, and embolization of portal vein injuries. We present a detailed illustrative review of the various radiological portal vein interventions.

Duplicated inferior vena cava-trifurcated portal vein: a rare anatomical variation encountered during Whipple procedure

The inferior vena cava (IVC) is the largest single vein in humans. However, during embryogenesis, abnormalities can occur resulting in a duplicated IVC. The portal vein (PV) offers the main blood flood to the liver, forming by the left and right PV. A number of anatomical variations are noticed, underlying the great importance of the pre-operative imaging workup. This case report presents a duplicated IVC and a trifucated PV that were incidentally found in an 82 year-old Caucasian male with pancreatic ductal adenocarcinoma who underwent pancreatoduodenectomy (Whipple procedure). Although some anatomical variations, including the duplication of the IVC and the trifurcation of PV, may be rare to the general population, the suspicion of their existence should always be taken under consideration from surgeons during hepatobiliary or retroperitoneal operations.

Clinical application of the contrast-enhancement boost technique in computed tomography angiography of the portal vein

PURPOSE

The aim of this study was to explore the improved image quality of the portal vein using the contrast-enhancement boost (CE-boost) technique for the improved visibility of abdominal-enhanced computed tomography (CT) scans in clinical practice.

METHODS

This retrospective study included 50 patients in Group A who underwent routine abdominal-enhanced CT and 50 patients in Group B who underwent abdominal computed tomography angiography (CTA) with matched body mass index, age, and sex. Images in Group A were postprocessed with the CE-boost technique for further enhanced visibility of the portal vein. Both subjective and objective assessments of different branches of the portal vein in three types of images (i.e., Group A with CE-boost and without CE-boost, Group B) were statistically analyzed.

RESULTS

The subjective scores of two experienced radiologists showed good consistency (kappa value > 0.624, p < 0.001), and the score of Group A with CE-boost (mean, 4.64) was significantly higher than that of the others (p < 0.001). The liver parenchyma and most target veins in Group A with CE-boost showed the highest CT, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) values and the lowest standard deviation (SD), while the CNR of most portal veins in Group A without CE-boost had the lowest CNR (p < 0.001). There were no differences in the SNR of the portal vein in Group A without CE-Boost and Group B (p > 0.05).

CONCLUSION

CE-boost can significantly improve image quality in portal vein imaging without any additional scanning settings or changes in the clinical workflow.

A rare variation of duplicated portal vein: left branch derived from splenic vein mimicking cavernous transformation

Background

Duplication of the portal vein is a rare type of anatomic variant of the portal vein (PV) system that can be incidentally found and can lead to various challenges and consequences. Herein, we report an unusual case to increase our understanding of such anatomic variants.

Case presentation

A 67-year-old asymptomatic woman was diagnosed with a liver space-occupying lesion by ultrasonography on a routine physical examination. The laboratory examinations from a local hospital suggested that her liver function tests were normal. The liver appeared normal on pre-contrast enhanced CT images. However, there were multiple complex abnormalities of PV found on contrast-enhanced CT scans, including two independent sources of PV (duplication), preduodenal PV, circum-portal pancreas, mimic cavernous transformation, abnormal branches of PV, and transient abnormal perfusion in the left lobe of the liver. MRI showed fatty infiltration in the left lobe of the liver.

Conclusion

This case extends our current understanding of the anatomical variations of the PV system. Knowledge of these complex and rare anatomical variations will help clinical doctors make a confident diagnosis or assist with proper planning of a surgical procedure.

High resolution flow (HR Flow) and glazing flow in cases of hepatic flow changes: Comparison to color-coded Doppler sonography (CCDS)

AIM

To evaluate the possibilities of flow detection using high resolution flow (HR Flow) and Glazing Flow technique in patients with liver parenchymal changes and flow changes in comparison to colour coded Doppler sonography (CCDS).

MATERIAL AND METHODS

All examinations were performed using a multi frequency matrix convex probe with high resolution technique (SC6-1U/Resona7, Mindray, Shenzhen, China) by one experienced examiner to evaluate the venous, portal venous and arterial liver flow with digital documentation of the dynamic flow parameters like peak systolic flow, end-diastolic flow and resistance index. For liver parenchymal stiffness changes shear wave elastography was performed with at least 10 measurements. By two independent readers an elevation was performed to evaluate the image quality and the degree of flow artefacts, from 0 = not available to 5 points with excellent image quality without flow artefacts.

RESULTS

All 40 patients (24 men, 16 women, age 27-83 years, mean 56±5 years) showed morphology changes from B-Mode of the liver parenchyma to inhomogeneous tissue with higher stiffness evaluated by the shear wave elastography (1.45 m/s up to 2.79 m/s±1.79 m/s, considering F1 up to F4 fibrosis) and in 15 cases histopathologically proven liver cirrhosis. In 9 cases after non-acute thrombosis flow reduction of the portal vein was the reason for the diameter less than 5 mm. Flow parameters for the venous flow were between 8 cm/s up to 29 cm/s, mean 14±4 cm/s, for the hepatic portal vein 5 cm/s up to 57 cm/s, mean 17±5 cm/s, for the hepatic artery systolic flow between 50 cm/s up to 127±33 cm/s, end-diastolic flow from 22 cm/s up to 47 cm/s±8 cm/s. Resistance index for the hepatic artery was between 0.41 up to 0.73, mean 0.67±0.25. The image quality for CCDS over all cases was evaluated for CCDS between 1 up to 4. The mean quality was 2.5±0.5, for HR Flow in combination with Glazing flow 3±0.5, with significant differences for the 2 readers (P <  0.01).

CONCLUSION

Combination of HR Flow with Glazing Flow could be helpful to evaluate morphological und hemodynamic changes of liver arterial flow, portal venous and venous flow. Reduction of flow artefacts in combination with a higher image quality could be helpful for optimizing the digital measurements also for follow up examinations.

Role of CT Imaging With Three-Dimensional Maximum Intensity Projection Reconstruction in the Evaluation of Portal Vein Variants at a Tertiary Care Hospital

INTRODUCTION

Portal vein (PV) is the principal blood vessel transporting blood from the alimentary tract and spleen to the liver. The aim of this study is to determine the prevalence of PV anatomical variations in our population using multidetector CT with maximum intensity projection (MIP) technique at a tertiary care hospital.

METHODS

This cross-sectional study was prospectively conducted from November 2018 to June 2019 in the Department of Radiology at a tertiary care hospital in Karachi. After informed consent, all the patients with no known hepatic pathology undergoing routine abdomen CT were included in this study. Patients with previous hepatic resection surgeries, undiagnosed large hepatic tumors/metastasis, and those with PV thrombosis were excluded.

RESULTS

A total of 500 patients (256 males and 244 females) were included in the study; the mean age of female patients was relatively higher as compared to the male patients (53.80 ± 18.44 vs. 44.15 ± 19.94 years; p = 0.000). Standard PV anatomy (type 1) was found in 438 patients (87.6%). Trifurcation (type 2) occurred in 18 patients (3.6%). Right posterior portal vein as the first branch of main PV (type 3) was found in 22 patients (4.4%). A separate branch of the right portal vein (RPV) to segment VII (type 4) and separate branch of the RPV to segment VI (type 5) were found in 6 (1.2%) and 16 (3.2%) patients, respectively.

CONCLUSION

Our study displayed a relatively higher frequency of standard PV anatomy (type 1) compared to previous studies. We highlight the role of MIP in the analysis of hepatic venous anatomy with its utility demonstrating improved detection of variations.