Hepatic Hemangioendothelioma: An update

Primary epithelioid hemangioendotheliomas of the liver(EHL)are rare tumors with a low incidence.The molecular background of EHL is still under investigation,with WWTR1-CAMPTA1 mutation may function as a tumor marker.Commonly,this tumor is misdiagnosed with angiosarcoma,cholangiocarcinomas,metastatic carcinoma,and hepatocellular carcinoma(sclerosing variant).Characteristic features on imaging modalities such as ultrasound,computed tomography,magnetic resonance imaging and positron emission tomography/computed tomography guide in diagnosis and staging.The“halo sign”and the“lollipop sign”on computed tomography and magnetic resonance imaging are described in the literature.Currently,there are no standardized guidelines for treating EHL with treatment options are broad including:chemotherapy,ablation,surgery and liver transplantation with inconsistent results.

Intraoperative abdominal ultrasound in oncologic imaging

Significant advances in ultrasound technology have created new opportunities for its use in oncologic imaging. The advent of new transducers with focal beam technology and higher frequency has solidified the role of intraoperative sonography (IOUS) as an invaluable imaging modality in oncologic surgery of the liver, kidneys and pancreas. The ability to detect and characterize small lesions and the precise intraoperative localization of such tumors is essential for adequate surgical planning in segmental or lobar hepatic resections, metastasectomy, nephron-sparing surgery, and partial pancreatectomy. Also, diagnostic characterization of small equivocal lesions deemed indeterminate by conventional preoperative imaging such as multidetector computed tomography or magnetic resonance imaging, has become an important application of IOUS. This article will review the current applications of IOUS in the liver, kidneys and pancreas.

Comparison of free breathing and respiratory triggered diffusion-weighted imaging sequences for liver imaging

BACKGROUND Diffusion-weighted imaging(DWI)has become a useful tool in the detection,characterization,and evaluation of response to treatment of many cancers,including malignant liver lesions.DWI offers higher image contrast between lesions and normal liver tissue than other sequences.DWI images acquired at two or more b-values can be used to derive an apparent diffusion coefficient(ADC).DWI in the body has several technical challenges.This include ghosting artifacts,mis-registration and susceptibility artifacts.New DWI sequences have been developed to overcome some of these challenges.Our goal is to evaluate 3 new DWI sequences for liver imaging.AIM To qualitatively and quantitatively compare 3 DWI sequences for liver imaging:free-breathing(FB),simultaneous multislice(SMS),and prospective acquisition correction(PACE).METHODS Magnetic resonance imaging(MRI)was performed in 20 patients in this prospective study.The MR study included 3 separate DWI sequences:FB-DWI,SMS-DWI,and PACE-DWI.The image quality,mean ADC,standard deviations(SD)of ADC,and ADC histogram were compared.Wilcoxon signed-rank tests were used to compare qualitative image quality.A linear mixed model was used to compare the mean ADC and the SDs of the ADC values.All tests were 2-sided and P values of<0.05 were considered statistically significant.RESULTS There were 56 lesions(50 malignant)evaluated in this study.The mean qualitative image quality score of PACE-DWI was 4.48.This was significantly better than that of SMS-DWI(4.22)and FB-DWI(3.15)(P<0.05).Quantitatively,the mean ADC values from the 3 different sequences did not significantly differ for each liver lesion.FB-DWI had a markedly higher variation in the SD of the ADC values than did SMS-DWI and PACE-DWI.We found statistically significant differences in the SDs of the ADC values for FB-DWI vs PACE-DWI(P<0.0001)and for FB-DWI vs SMS-DWI(P=0.03).The SD of the ADC values was not statistically significant for PACE-DWI and SMS-DWI(P=0.18).The quality of the PACE-DWI ADC histograms were considered better than the SMS-DWI and FB-DWI.CONCLUSION Compared to FB-DWI,both PACE-DWI and SMS-DWI provide better image quality and decreased quantitative variability in the measurement of ADC values of liver lesions.

Imaging of benign and malignant cystic pancreatic lesions and a strategy for follow up

Cystic lesions in a variety of organs are being increasingly recognized as an incidental finding on cross-sectional imaging.These lesions can be benign,premalignant or malignant.When these cystic lesions are small it can be difficult to characterize them radiologically.However,with appropriate clinical history and knowledge of typical imaging features of cystic pancreatic lesions this can enable accurate diagnosis and thus guide appropriate treatment.In this review,we provide an overview of the most common types of cystic lesions and their appearance on computer tomography,magnetic resonance imaging and ultrasound.We will also discuss the follow up and management strategies of these cystic lesions.

Advances and effectiveness of the immunotherapy after liver transplantation

Transplant recipients usually have increased chances of graft rejection and graft vs host disease,requiring chronic immunosuppressive therapy.Nonetheless,longterm immunosuppression risks malignancies such as skin cancer,lymphoma,and Kaposi sarcoma.However,there are very few studies that included solid organ transplant recipients while studying the efficacy of immunotherapy.“Immunotherapy after liver transplantation:Where are we now?”is a study,where the authors described the mechanism of action and outcomes of immune checkpoint inhibitors specific to liver transplant recipients.The authors reported the graft rejection rates and the factors contributing to the rejection in the liver transplant recipients.

Comments on"Review of the role of diagnostic modalities and imaging findings in the COVID-19 pandemic"

The present letter to the editor corresponds to the article entitled“Comprehensive literature review on the radiographic findings,imaging modalities,and the role of radiology in the coronavirus disease 2019(COVID-19)pandemic”by Pal et al,published in World J Radiol.2021;13(9):258-282.With zero to unknown prevalence,COVID-19 has created a heterogeneous and unforeseen situation across the world.Healthcare providers encountered new challenges in image interpretation,characterization,and prognostication of the disease.Pal et al delineated the radiological findings,which would guide the radiologists to identify the early signs of severe infection.