Spontaneous portosystemic shunt (SPSS) refers to collateral vessels that communicate between the portal vein system and systemic circulation. SPSS mainly includes esophageal varices, gastric varices, left gastric vein, recanalized paraumbilical vein, abdominal wall varices, and spontaneous splenorenal shunt. SPSS contributes to the development of hepatic encephalopathy caused by portal vein inflow bypassing and carries a higher risk of death in liver cirrhosis. Abdominal contrast-enhanced computed tomography is a major imaging approach to establish a diagnosis of SPSS and evaluate its location and feature. This review primarily describes the main contrast-enhanced CT features of SPSS in liver cirrhosis.

Noninvasive and real-time visualization of the thoracoepigastric veins (TVs) of living mice was demonstrated by using two-photon excitation (TPE) optical imaging with a Eu-luminescent polymeric nanoagent as the angiographic contrast. The spatiotemporal evolution of the polymeric nanoagent in TVs was monitored for up to 2 h by TPE time-resolved (TPE-TR) bioimaging, which is free from the interference of tissue autofluorescence. A wide field-of-view covering the thoracoabdominal region allowed the visualization of the entire TV network with an imaging depth of 1 to 2 mm and a lateral resolution of 80 μm at submillimeter. Detailed analysis of the uptake, transport, and clearance processes of the polymeric nanoagent revealed a clearance time constant of ∼30  min and an apparent clearance efficiency of 80% to 90% for the nanoagent in both axial and lateral TVs. TPE-TR imaging of the dissected internal organs proved that the liver is mainly responsible for the sequestration of the nanoagent, which is consistent with the apparent retention efficiency of liver, ∼32  %  , as determined by the real-time in vivo TV imaging. We demonstrate the potency of TPE-TR modality in the pharmacokinetics imaging of the peripheral vascular systems of animal models, which can be beneficial for related nanotheranostics study.

Musculoskeletal problems in patients with liver disease are common; however, they are not so well described in the literature. Therefore, there is a need to collate information on these disorders, as their incidence is on a constant rise and some of these pathologies can severely debilitate the patient's quality of life. These disorders are parietal wall varices with or without bleeding, spontaneous intramuscular haematoma (e.g. rectus sheath), abdominal wall hernia, anasarca, hepatic osteodystrophy, septic arthritis, osteomyelitis, necrotizing fasciitis, osseous metastases from hepatocellular carcinoma etc. While portal hypertension plays a key role in disorders, in others, dysregulation of the coagulation system or a compromised immune system are responsible. Imaging plays an essential role in the assessment of these complications and awareness of these musculoskeletal manifestations is vital for establishing a timely diagnosis and planning of appropriate therapy, as these disorders can significantly impact the morbidity and mortality and also influence candidacy for liver transplantation. We herein comprehensively appraise various musculoskeletal complications associated with chronic liver disease/liver cirrhosis especially from an imaging perspective which, to the best of our knowledge, have not been collectively described in English literature.

Carbon dioxide embolism is a rare but potentially fatal complication of laparoscopic surgery. The most common cause is inadvertent injection of carbon dioxide into a large vein or solid organ during initial peritoneal insufflation. We describe a case of carbon dioxide embolism in a 13-year-old boy during an elective laparoscopic cholecystectomy, caused by injection of carbon dioxide into a large paraumbilical vein. The clinical manifestations of carbon dioxide embolism were hypotension, bradycardia, and an abrupt drop in end-tidal CO2. He subsequently did well and had no sequelae. Carbon dioxide embolism is a recognized complication of laparoscopic surgery, although the risk to the patient may be minimized by the surgical team's awareness of the problem, continuous intraoperative monitoring of end-tidal CO2, and using an open technique for initial access to the peritoneum.

To evaluate the efficacy of CT-maximum intensity projection (CT-MIP) in the detection of gastric varices and their inflowing and outflowing vessels in patients with gastric varices scheduled to undergo balloon-occluded retrograde transvenous obliteration (B-RTO).

Sixteen patients with endoscopically confirmed gastric varices were included in this study. All patients were evaluated with CT-MIP using three-dimensional reconstructions, before and after B-RTO.

CT-MIP clearly depicted gastric varices in 16 patients (100%), the left gastric vein in 6 (32.5%), the posterior gastric vein in 12 (75.0%), the short gastric veins in 13 (81.3%), gastrorenal shunts in 16 (100%), the hemiazygos vein (HAZV) in 4 (25.0%), the pericardiophrenic vein (PCPV) in 9 (56.3%), and the left inferior phrenic vein in 9 patients (56.3%). Although flow direction itself cannot be determined from CT-MIP, this modality provided clear images of the inflowing and the outflowing vessels. Moreover, in one patient, short gastric veins were not seen on conventional angiographic portography images of the spleen, but were clearly revealed on CT-MIP.

We suggest that CT-MIP should be considered as a routine method for detecting and diagnosing collateral veins in patients with gastric varices scheduled for B-RTO. Furthermore, CT-MIP is more useful than endoscopy in verifying the early therapeutic effects of B-RTO.

Contrast enhanced helical computed tomography (CT) of the liver and portal system is routinely performed in human patients. The purpose of this project is to develop a practical protocol for helical CT portography in the dog. Ten clinically normal dogs were initially evaluated to develop a protocol. Using this protocol, ten dogs with confirmed portosystemic shunts (PSS) were then evaluated. Each patient was anesthetized, and a test dose of sodium iothalamate (400 mg I/ml) at 0.55 ml/kg was injected. Serial images were acquired at the level of T12-13 or T13-L1. The time to maximum enhancement of the portal vein was determined. This time period was used as the period between the second injection (2.2 ml/kg) and the start of the helical examination of the cranial abdomen. Delay times for normal dogs ranged from 34.5 s-66.0 s (median: 43.5 s) or 1.41 s/kg-4.12 s/kg (median: 2.09 s/kg). For patients with a PSS, the delay times were 16.5-70.5 s (median: 34.5 s) or 1.47-19.17 s/kg (median: 3.39 s/kg). The aorta, caudal vena cava, portal vein, shunt vessels, and their respective branches were well visualized on the CT images. Clinical case results were surgically confirmed. The surgeons reported that the information gained from the CT portography resulted in a subjective decrease in surgical time and degree of dissection necessary compared with similar surgeries performed without angiographic information. We believe that helical CT portography in the dog will be a useful adjunct in the diagnosis of PSS. The use of helical CT portography may allow clinicians to give clients a more accurate prognosis prior to surgery and will allow patients with lesions that are not surgically correctable to avoid a costly and invasive procedure.

The purpose of this article was to describe the CT finding of dilated thoracoabdominal veins in patients with renal failure who have arteriovenous fistulas or grafts (AVF/G) for hemodialysis.

The authors retrospectively identified nine women and nine men on hemodialysis with a mean age of 62 (range, 20-88) years. Inclusion criteria for the series were functioning AVF/G, imaging with chest or abdominal CT, and access to clinical charts. Each clinical chart was evaluated for AVF/G function, diagnosis of cirrhosis or central venous obstruction, hepatitis B and C serology, and liver function as reflected by serum SGOT/SGPT. Each CT was reviewed for evidence of cirrhosis as follows: nodular liver contour, prominent left and caudate lobes, splenomegaly, and ascites. The CT scans were also evaluated for the presence of dilated thoracic or abdominal veins. The contrast-enhanced scans were evaluated for obstruction of the visualized central veins.

Fifty percent (9 of 18) of patients had dilated thoracoabdominal veins involving the following sites: chest wall, internal mammary, inferior phrenic, left gastric, gastric, portal, periportal, preaortic, mesenteric, splenorenal, periumbilical, and omental. None of these patients had clinical or CT evidence of cirrhosis. Eighty-nine percent (eight of nine patients) had normal serum SGOT/SGPT. Hepatitis B serology was normal in all seven patients tested, and hepatitis C serology was normal in 86% (six of seven patients). Eighty-nine percent (eight of nine patients) had no clinical or CT evidence of central venous obstruction. Among the nine patients without dilated veins, none had the clinical diagnosis of cirrhosis, although 56% (five of nine) had one or more CT findings associated with cirrhosis. None was diagnosed with central venous obstruction. Sixty-seven percent (six of nine patients) of those tested had normal serum SGOT/SGPT. Hepatitis B serology was normal in 88% (seven of eight) and 63% (five of eight) of patients tested, respectively. The authors did not find statistically significant differences between the patients with and without dilated veins with respect to the above parameters.

Dilated thoracoabdominal veins were present in 50% of patients on hemodialysis with functioning AVF/G in this series. The venous dilatation appears to be independent of cirrhosis and central venous obstruction and is likely related to complex physiologic changes that are known to occur in patients on hemodialysis with functioning AVF/G.

Spontaneous portosystemic shunts (varices) are a well-known complication of severe liver disease and portal hypertension. Computed tomographic (CT) angiography was used to image the hepatic vasculature of 198 patients with end-stage liver disease in anticipation of liver transplantation. Performance of a delayed acquisition during the portal phase of enhancement enables evaluation of portal and variceal anatomy without the need for an additional injection of contrast material. Three-dimensional (3D) reconstruction of portal-phase CT angiograms enhances the perception of the courses and anatomic relationships of varices. This information is valuable for surgical planning. Common varices include the left gastric vein, short gastric veins, paraumbilical veins, and splenic vein; in cases of more unusual, complex shunts, 3D rendering is indispensable. By precisely demonstrating the courses of varices, CT angiography allows the surgeon to plan the operative approach and determine the need for surgical varix ligation or preoperative interventional embolization.

This study seeks to evaluate three-dimensional (3D) helical CT portography as a tool for examining patients with gastric fundic varices.

We compared 3D helical CT portography and conventional angiographic portography in 30 consecutive patients with gastric fundic varices. We assessed whether 3D helical CT portography is useful in selecting patients and in evaluating the results of balloon-occluded retrograde transvenous obliteration.

Three-dimensional helical CT portography simultaneously depicted second or third branches of the intrahepatic portal vein and provided images of entire portosystemic collaterals. On 3D helical CT portography, gastric fundic varices were seen in 30 patients (100%), left gastric veins in 19 (63%), posterior gastric veins or short gastric veins in 28 (93%), gastrorenal shunts in 27 (90%), paraumbilical veins in three (10%), and inferior phrenic veins in two patients (7%). Findings of 3D helical CT portography and conventional angiographic portography were in close agreement. However, in four patients, posterior gastric veins or short gastric veins were not seen on conventional angiographic portography images of the spleen, but they were clearly revealed on 3D helical CT portography. Treatment was successful in all patients except one. Three-dimensional helical CT portography could easily evaluate therapeutic results.

Three-dimensional helical CT portography proved so effective that it can be considered a less invasive alternative than conventional angiographic portography in assessing portosystemic collaterals. CT portography is useful in selecting candidates from patients with gastric fundic varices for retrograde transvenous obliteration and also in evaluating therapeutic results.

We determined the sensitivity of computed tomography and color duplex ultrasonography in the detection and characterization of vascular complications in acute pancreatitis. The relationship of these complications with the etiology and activity of the disease was assessed. In a prospective study, 189 patients with acute pancreatitis seen in the Department of Gastroenterology. Charité Hospital in Berlin over a period of 38 months underwent color duplex ultrasonography every second day for 3 weeks and thereafter at least once a week for 2 months. Dynamic computed tomography was performed within 72 hours after admission, and follow-up computed tomography scans were obtained. In 45 patients (23%), at least temporary thromboses of portal venous vessels were demonstrated by color duplex ultrasonography. The incidence of venous thromboses was 30% in severe acute pancreatitis with fluid collections without necroses and 57% in necrotizing pancreatitis. In 27 of those 45 patients, a formation of collaterals was documented. In 13 patients, arterial pseudoaneurysms were demonstrated. Vascular complications were significantly more frequent in alcohol-induced than in gallstone-induced pancreatitis. Only 62% of all sonographically diagnosed thromboses and only 32% of all collaterals were demonstrated by computed tomography. The prevalence of vascular complications in acute pancreatitis was much higher as suspected. The risk of gastrointestinal bleeding was lower than previously reported. Color duplex sonography is the method of choice for the detection of vascular complications in acute pancreatitis.