A case of ascending colon variceal bleeding treated with venous coil embolization

A 38-year-old female with a history of alcoholic liver cirrhosis visited our hospital with a massive hematochezia.An esophagogastroduodenoscopy did not demonstrate any bleeding source,and a colonoscopy showed a massive hemorrhage in the ascending colon but without an obvious focus.The source of the bleeding could not be found with a mesenteric artery angiography.We performed an enhanced abdominal computed tomography,which revealed a distal ascending colonic varix,and assumed that the varix was the source of the bleeding.We performed a venous coil embolization and histoacryl injection to obliterate the colon varix.The intervention appeared to be successful because the vital signs and hemoglobin laboratory data remained stable and because the hematochezia was no longer observed.We report here on a rare case of colonic variceal bleeding that was treated with venous coil embolization.

Helicobacter pylori in gastric carcinogenesis

Gastric cancer still is a major concern as the third most common cancer worldwide, despite declining rates of incidence in many Western countries. Helicobacter pylori(H. pylori) is the major cause of gastric carcinogenesis, and its infection insults gastric mucosa leading to theoccurrence of atrophic gastritis which progress to intestinal metaplasia, dysplasia, early gastric cancer, and advanced gastric cancer consequently. This review focuses on multiple factors including microbial virulence factors, host genetic factors, and environmental factors, which can heighten the chance of occurrence of gastric adenocarcinoma due to H. pylori infection. Bacterial virulence factors are key components in controlling the immune response associated with the induction of carcinogenesis, and cag A and vac A are the most well-known pathogenic factors. Host genetic polymorphisms contribute to regulating the inflammatory response to H. pylori and will become increasingly important with advancing techniques. Environmental factors such as high salt and smoking may also play a role in gastric carcinogenesis. It is important to understand the virulence factors, host genetic factors, and environmental factors interacting in the multistep process of gastric carcinogenesis. To conclude, prevention via H. pylori eradication and controlling environmental factors such as diet, smoking, and alcohol is an important strategy to avoid H. pylori-associated gastric carcinogenesis.

Nuclear imaging for functional evaluation and theragnosis in liver malignancy and transplantation

Currently,nuclear imaging such as positron emission tomography(PET)and single photon emission computed tomography(SPECT)is increasingly used in the management of liver malignancy.18F-fluorodeoxyglucose(FDG)-PET is the most widely used nuclear imaging in liver malignancy as in other cancers,and has been reported to be effective in diagnosis,response monitoring,recurrence evaluation,and prognosis prediction.Other PET imaging such as 11C-acetate PET is also used complementarily to FDG-PET in diagnosis of liver malignancy.Additionally,image-based evaluation of regional hepatic function can be performed using nuclear imaging.Those imaging modalities are also effective for candidate selection,treatment planning,and perioperative evaluation in liver surgery and transplantation.Recently,nuclear imaging has been actively adopted in the transarterial radioembolization therapy of liver malignancy,according to the concept of theragnosis.With the development of new hybrid imaging technologies such as PET/magnetic resonance imaging and SPECT/CT,nuclear imaging is expected to be more useful in the management of liver malignancy,particularly regarding liver surgery and transplantation.In this review,the efficacy and roles of nuclear imaging methods in diagnosis,transplantation and theragnosis are discussed.

Recent advances in parametric neuroreceptor mapping with dynamic PET:basic concepts and graphical analyses

Tracer kinetic modeling in dynamic positron emission tomography （PET） has been widely used to investigate the characteristic distribution patterns or dysfunctions of neuroreceptors in brain diseases. Its practical goal has progressed from regional data quantification to parametric mapping that produces images of kinetic-model parameters by fully exploiting the spatiotemporal information in dynamic PET data. Graphical analysis （GA） is a major parametric mapping technique that is independent on any compartmental model configuration, robust to noise, and computationally efficient. In this paper, we provide an overview of recent advances in the parametric mapping of neuroreceptor binding based on GA methods. The associated basic concepts in tracer kinetic modeling are presented, including commonly-used compartment models and major parameters of interest. Technical details of GA approaches for reversible and irreversible radioligands are described, considering both plasma input and reference tissue input models. Their statistical properties are discussed in view of parametric imaging.