Proposal of a computed tomography classification for hepatic alveolar echinococcosis

Chemotherapy for the treatment of alveolar echinococcosis: Where are we?

Alveolar echinococcosis (AE) is a severe liver disease due to infection with the Echinococcus multilocularis larval stage, called the metacestode. Management of AE is based on benzimidazole chemotherapy (albendazole or mebendazole), associated with surgery when possible. Benzimidazoles are the only compounds recommended for the treatment of AE; however, these are parasitostatic, which means that the parasite can resume growth when treatment is interrupted. Also, benzimidazoles can cause liver dysfunction which may prevent their use. Numerous drugs have been reported to have in vitro activity against E. multilocularis, but few had satisfactory in vivo activity, and none were clearly more effective than benzimidazoles. These drugs belong to various therapeutic categories including anti-infective agents (e.g. amphotericin B, mefloquine, pentamidine derivatives), anti-neoplastic compounds (e.g. imatinib, nilotinib, bortezomib), plant-extracted compounds (e.g. thymol, crocin, carvacrol) and others (e.g. metformin, verapamil, thiaclopride). These treatments are generally of limited interest due to their toxicity, their unfavorable pharmacokinetics, or the scarcity of studies involving humans. Apart from benzimidazoles, only amphotericin B, mefloquine and nitazoxanide have been reported to be used for human AE treatment, with unsatisfactory results. Few studies have aimed at developing innovative strategies for AE drug therapy, such as vectorization of drugs using nanoparticles. Altogether, this review emphasizes the urgent need for new therapeutic strategies in AE management, for which there is currently no curative chemotherapy.

Rare presentation of hepatic alveolar echinococcosis mimicking hepatocellular carcinoma

A complex liver lesion presents a significant challenge in terms of diagnosis and management. This case is an illustrative example, highlighting the steps involved in managing such complex scenarios. This patient, in her early 20s, presented with a fever associated with worsening abdominal pain, as well as a background history of chronic abdominal pain, anorexia, vomiting, constipation and weight loss. The radiology revealed an irregular complex cyst in the liver with biliary and vascular invasion, raising concerns about hepatocellular carcinoma. The diagnosis was changed to alveolar echinococcosis after the infectious diseases consultant gave helpful advice, and echinococcosis antibodies were found. We subsequently started the patient on albendazole therapy. Following prudent advice from hepatobiliary surgeons and given the complexity of the hepatic lesion, a liver transplant was considered the best management option due to the extensive involvement of the biliary and venous systems. The combined approach of albendazole and a liver transplant marked a transformative phase for this patient, putting an end to her prolonged suffering.

A deep learning radiomics model based on CT images for predicting the biological activity of hepatic cystic echinococcosis

Introduction: Hepatic cystic echinococcosis (HCE) is a widely seen parasitic infection. Biological activity is crucial for treatment planning. This work aims to explore the potential applications of a deep learning radiomics (DLR) model, based on CT images, in predicting the biological activity grading of hepatic cystic echinococcosis. Methods: A retrospective analysis of 160 patients with hepatic echinococcosis was performed (127 and 33 in training and validation sets). Volume of interests (VOIs) were drawn, and radiomics features and deep neural network features were extracted. Feature selection was performed on the training set, and radiomics score (Rad Score) and deep learning score (Deep Score) were calculated. Seven diagnostics models (based on logistic regression algorithm) for the biological activity grading were constructed using the selected radiomics features and two deep model features respectively. All models were evaluated using the receiver operating characteristic curve, and the area under the curve (AUC) was calculated. A nomogram was constructed using the combined model, and its calibration, discriminatory ability, and clinical utility were assessed. Results: 12, 6 and 10 optimal radiomics features, deep learning features were selected from two deep learning network (DLN) features, respectively. For biological activity grading of hepatic cystic echinococcosis, the combined model demonstrated strong diagnostic performance, with an AUC value of 0.888 (95% CI: 0.837-0.936) in the training set and 0.876 (0.761-0.964) in the validation set. The clinical decision analysis curve indicated promising results, while the calibration curve revealed that the nomogram's prediction result was highly compatible with the actual result. Conclusion: The DLR model can be used for predicting the biological activity grading of hepatic echinococcosis.

A CT-based radiomics model for predicting lymph node metastasis in hepatic alveolar echinococcosis patients to support lymph node dissection

BACKGROUND

Hepatic alveolar echinococcosis (AE) is a severe zoonotic parasitic disease, and accurate preoperative prediction of lymph node (LN) metastasis in AE patients is crucial for disease management, but it remains an unresolved challenge. The aim of this study was to establish a radiomics model for the preoperative prediction of LN metastasis in hepatic AE patients.

METHODS

A total of 100 hepatic AE patients who underwent hepatectomy and hepatoduodenal ligament LN dissection at Qinghai Provincial People's Hospital between January 2016 and August 2023 were included in the study. The patients were randomly divided into a training set and a validation set at an 8:2 ratio. Radiomic features were extracted from three-dimensional images of the hepatoduodenal ligament LNs delineated on arterial phase computed tomography (CT) scans of hepatic AE patients. Least absolute shrinkage and selection operator (LASSO) regression was applied for data dimensionality reduction and feature selection. Multivariate logistic regression analysis was performed to develop a prediction model, and the predictive performance of the model was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA).

RESULTS

A total of 7 radiomics features associated with LN status were selected using LASSO regression. The classification performances of the training set and validation set were consistent, with area under the operating characteristic curve (AUC) values of 0.928 and 0.890, respectively. The model also demonstrated good stability in subsequent validation.

CONCLUSION

In this study, we established and evaluated a radiomics-based prediction model for LN metastasis in patients with hepatic AE using CT imaging. Our findings may provide a valuable reference for clinicians to determine the occurrence of LN metastasis in hepatic AE patients preoperatively, and help guide the implementation of individualized surgical plans to improve patient prognosis.

Clinical value of the semi-quantitative parameters of 18F-fluorodeoxyglucose PET/CT in the classification of hepatic echinococcosis in the Qinghai Tibetan area of China

BACKGROUND

To investigate the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) semi-quantitative parameters, including the lesion diameter, maximum standardized uptake value (SUVmax), maximum standardized uptake value corrected for lean body mass (SULmax), metabolic lesion volume (MLV), and total lesion glycolysis (TLG), for classifying hepatic echinococcosis.

METHODS

In total, 20 patients with 36 hepatic echinococcosis lesions were included in the study. Overall, these lesions were categorized as hepatic cystic echinococcosis (HCE) or hepatic alveolar echinococcosis (HAE) according to the pathological results. Multiple semi-parameters including the maximum diameter, SUVmax, SULmax, MLV, and TLG were measured to classify HCE and HAE compared with the pathological results. The receiver operator characteristic curve and area under the curve (AUC) of each quantitative parameter were calculated. The Mann-Whitney U test was used to compare data between the two groups.

RESULTS

In total, 12 cystic lesions and 24 alveolar lesions were identified after surgery. There were significant differences in SUV max, SUL max, MLV, and TLG between the HAE and HCE groups (Z =  - 4.70, - 4.77, - 3.36, and - 4.23, respectively, all P < 0.05). There was no significant difference in the maximum lesion diameter between the two groups (Z =  - 0.77, P > 0.05). The best cutoffs of SUV max, SUL max, MLV, and TLG for the differential diagnosis of HAE and HCE were 2.09, 2.67, 27.12, and 18.79, respectively. The AUCs of the four parameters were 0.99, 0.99, 0.85, and 0.94, respectively. The sensitivities were 91.7%, 87.5%, 66.7%, and 85.6%, respectively, and the specificities were 90.1%, 91.7%, 83.3%, and 90.9%, respectively.

CONCLUSION

18F-FDG PET/CT semi-quantitative parameters had significant clinical value in the diagnosis and pathological classification of hepatic echinococcosis and evaluation of clinical treatment.

Current status and future prospects of Echinococcus multilocularis vaccine candidates: A systematic review

The larval stages of Echinococcus multilocularis (E. multilocularis) are what cause the zoonotic disease known as alveolar echinococcosis (AE). Identifying the antigens that trigger immune responses during infection is extremely important for the development of vaccines against Echinococcus infections. Several studies conducted in recent decades have described the specific traits of the protective antigens found in E. multilocularis and their role in immunizing different animal hosts. The objective of the current systematic review was to summarize the findings of relevant literature on this topic and unravel the most effective vaccine candidate antigens for future research. A comprehensive search was conducted across five databases, including ProQuest, PubMed, Scopus, ScienceDirect, and Web of Science, until March 1, 2023. Two reviewers autonomously conducted the screening and evaluation of data extraction and quality assessment. In the present study, a total of 41 papers matched the criteria for inclusion. The study findings indicate that the combination of Em14-3-3 and BCG is widely considered the most often employed antigens for E. multilocularis immunization. In addition, the study describes antigen delivery, measurement of immune responses, adjuvants, animal models, as well as routes and doses of vaccination. The research indicated that recombinant vaccines containing EMY162, EM95, and EmII/3-Em14-3-3 antigens and crude or purified antigens containing ribotan-formulated excretory/secretory antigens exhibited the most favorable outcomes and elicited protective immune responses.

Computed tomography angiography of liver alveococcosis: a case report

BACKGROUND

Alveococcosis, helminthiasis caused by the larvae of Alveococcus multilocularis, is characterized by the formation of parasitic nodes in the liver. This clinical case is a rare occurrence of liver alveococcosis in Uzbekistan.

CASE PRESENTATION

We present a case of a 33-year-old Asian woman from Uzbekistan who complained of discomfort in the epigastric region and right hypochondrium, along with general weakness. She had been experiencing symptoms for 5 months when a routine ultrasound examination revealed a structural formation in the liver. Patient was investigated by using contrast enhanced computed tomography (CT) and diagnosed with liver alveococcosis with multiple lesions. Patient underwent diagnostic laparotomy with obtaining gross specimen, biomaterial was examined microscopically and found that there were small fragments of fibrous tissue determined together with small groups of cystic formations and walls consisted of chitin. Moreover, contrast enhanced CT allowed us to differentiate liver alveococcosis from cavernous hemangioma, hepatocellular carcinoma, and liver metastases from unknown source.

CONCLUSION

Contrast enhanced CT plays a major role in differentially diagnosing liver alveococcosis and makes it the first line method of choice for the consideration of the future treatment and surgical interventions.

Computed tomographic appearance of canine hepatic alveolar echinococcosis

Alveolar echinococcosis (AE) is caused by Echinococcus multilocularis, affecting dogs as accidental intermediate hosts. CT is increasingly used for abdominal imaging in small animals, providing valuable information, particularly for large masses and limited ultrasound accessibility. This study describes CT findings of hepatic lesions in 13 dogs with AE. All cases displayed well-defined cavitary lesions in the liver. Lesions showed minimal to no contrast uptake in the periphery, no uptake centrally, irregular internal walls, and soft tissue septa. Eight of 13 cases exhibited large cavitary masses (mean diameter 18.7 cm) with thick walls and feathery mineralization. Three of 13 cases had multiple smaller cavitary lesions with thin walls and without mineralization (mean diameter 8.4 cm). Two of 13 cases presented with both lesion types. These findings suggest two typical CT appearances correlated with AE: large thick-walled- and smaller thin-walled lesions. These groups may represent different stages of AE, with smaller lesions merging and progressing into larger ones. In conclusion, CT provides valuable information in evaluating hepatic lesions in dogs with AE. Large cavitary, thick-walled liver lesions with feathery wall mineralization, irregular inner margination, septation, and no central contrast uptake strongly indicate hepatic AE in dogs, differentiating it from other masses.

Echinococcoses - A Primer for Radiologists

BACKGROUND

Cystic (CE) and alveolar (AE) echinococcoses are zoonotic parasitoses that may pose diagnostic problems due to their relative rarity in Middle Europe.

METHODS

Based on a recent literature search and the observation of casuistics from a national echinococcosis treatment center, epidemiological, radiological, and therapeutic fundamentals are presented and important differences between AE and CE are discussed.

RESULTS AND CONCLUSION

AE and CE must be regarded as completely different diseases, which differ from each other in every significant aspect. This applies not only to the epidemiological background of the patients but also to the biology of the diseases and their respective imaging features.

KEY POINTS

· AE and CE are very distinct from one another and must be considered separately.. · AE is endemic in Middle Europe and is known as malignant parasitosis due to its destructive growth form.. · CE is primarily seen in Middle Europe in individuals with migration background and has a rather benign character..

CITATION FORMAT

· Weber TF, Mokry T, Stojkovic M. Die Echinokokkosen - Einblicke aus Sicht der Radiologie. Fortschr Röntgenstr 2023; 195: 1106 - 1121.

Pediatric Echinococcosis of the Liver in Austria: Clinical and Therapeutical Considerations

Echinococcosis is considered a neglected disease in most European countries. However, migratory flows of populations, long-term stays in endemic areas, uninterrupted tourism (travel to Echinococcus-endemic countries), traveling dogs and dog translocations from endemic areas, and inappropriate hygiene practices are potential factors that alarm public health officials. Identifying a cyst-like mass in the liver or lung of an individual with a travel history of likely exposure to sheepdogs in an area where the parasite Echinococcus (E.) granulosus (sive cysticus) is endemic advocates for a prompt preliminary diagnosis of cystic echinococcosis (CE), no matter the age of the affected individuals. Routine imaging techniques, including ultrasonography, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans, are used to detect cysts. After a cyst has been discovered, serologic investigations are used to confirm the diagnosis. Typically, alveolar echinococcosis (AE) is found in older individuals. Yet young people are also affected because frequent oral exploration of the environment is a regular behavior for infants and toddlers. In this review, therapeutic considerations for pediatric echinococcosis—drug-based benzimidazole therapy; AE: atypical liver resection, the resection of individual or multiple segments, a right or left hemi-hepatectomy, or an extended hemi-hepatectomy; CE: PAIR-technique, cyst excision, liver segment(s) resection (laparoscopically or conventionally)—are revised following experience in one of the most affected regions of Europe. In addition, we performed a systematic review using three databases (i.e., PubMed, EMBASE, and Scopus) to evaluate the quality of evidence in published studies on pediatric echinococcosis.

Multidetector computed tomography assessment of venous invasion in hepatic alveolar echinococcosis

PURPOSE

The objective of this study was to correlate multidetector computed tomography (MDCT) findings in hepatic alveolar echinococcosis (HAE) with intraoperative and postoperative histopathological results to identify reliable MDCT criteria for the diagnosis of HAE venous invasion.

METHODS

A total of 136 HAE patients who underwent CT examination were included in this study. The lesion-vessel contact angle, irregular wall, lumen stenosis and occlusion were evaluated.

RESULTS

A total of 614 veins were estimated. In total, 510 veins were invaded, and 104 veins were not. The invasion rate was 83.06%. In single CT findings, with a cutoff value of > 180° determined by receiver operating characteristic (ROC) curve analysis, the lesion-vessel contact angle performed the best (area under the ROC curve, AUC = 0.907, 95% confidence interval, 95% CI 0.872-0.941, p < 0.001), with a sensitivity, specificity and positive likelihood ratio (PLR) of 84.90%, 88.46%, and 7.35, respectively. Irregular wall and lumen stenosis showed the lowest diagnostic performance. Diagnostic performance was the highest when combining these criteria and signs (AUC = 0.932, 95% CI 0.905-0.960, p < 0.001).

CONCLUSION

The lesion-vessel contact angle > 180° had the best sensitivity and specificity in the diagnosis of HAE venous invasion, and good interobserver agreement had been noted. The diagnostic performance of the lesion-vessel contact angle > 180° had been further improved with the addition of lumen occlusion accompanied by irregular wall or lumen stenosis.

Alveolar and neotropical echinococcosis

The urgency of the problem of human alveolar and neotropic echinococcosis is due to polymorphism and the severity of clinical manifestations. The purpose and result of the work is to summarize the data available in the literature on the etiology, epidemiology, clinic, diagnosis, treatment, prevention of alveolar and neotropic echinococcosis in humans. Conclusion. The causative agent of human alveolar echinococcosis is E. multilocularis, neotropic – E. vogeli, E. oligarthra. The liver and lungs are most often affected, less often other organs of the abdominal cavity, bones, brain, spinal cord, eyes, etc. Diagnostics is carried out on the basis of a complex of clinical, instrumental, serological, molecular genetic studies. Treatment includes surgical removal of parasitic cysts and drug therapy.

Prediction of benzimidazole therapy duration with PET/CT in inoperable patients with alveolar echinococcosis

Alveolar echinococcosis is a rare parasitic disease, most frequently affecting the liver, as a slow-growing tumor-like lesion. If inoperable, long-term benzimidazole therapy is required, which is associated with high healthcare costs and occasionally with increased morbidity. The aim of our study was to determine the role ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in staging of patients with alveolar echinococcosis and to identify quantitative imaging parameters related to patient outcome and/or duration of benzimidazole therapy. In this single-center retrospective cohort study, 47 PET/CT performed for staging in patients with confirmed alveolar echinococcosis were analysed. In 43 patients (91%) benzimidazole therapy was initiated and was successfully stopped after a median of 870 days (766–2517) in 14/43 patients (33%). In inoperable patients, tests for trend of survivor functions displayed clear trends for longer benzimidazole therapy duration (p = 0.05; n = 25), and for longer time intervals to reach non-detectable serum concentration of Em-18 antibodies (p = 0.01, n = 15) across tertiles of SUVratio (maximum standardized uptake value in the echinococcus manifestation compared to normal liver tissue). Hence, in inoperable patients with alveolar echinococcosis, PET/CT performed for staging may predict the duration of benzimidazole therapy.

18F-FDG-PET/MR in Alveolar Echinococcosis: Multiparametric Imaging in a Real-World Setting

Recent improvements in alveolar echinococcosis (AE) therapy can provide long-term disease control, and even allow structured treatment interruption in selected cases. Imaging has a pivotal role in monitoring disease activity, with 18-fluoro-deoxyglucose positron emission and computed tomography (18F-FDG-PET/CT) in particular having proven beneficial for assessing disease activity. Repetitive regular examinations to monitor therapy response, however, can lead to substantial radiation burden. Therefore, by combining metabolic information and excellent tissue contrast in magnetic resonance imaging (MRI), PET/MR appears ideally suited for this task. Here, we retrospectively analyzed 51 AE patients that underwent 18F-FDG-PET/MR. Patients had a ‘confirmed/probable’ diagnosis in 22/29 cases according to the WHO classification. FDG uptake, diffusion restriction, and MRI morphology were evaluated. We found significant differences in FDG uptake between responders to benzimidazole therapy and progressive manifestations (SUVavg 2.7 ± 1.3 vs. 5.4 ± 2.2, p < 0.001) as well as between Kodama Types 1 and 3 (F = 9.9, p < 0.003). No significant differences were detected for ADC values or MRI morphology concerning response and no correlations were present between FDG uptake and ADC values. The mean radiation dose was 5.9−6.5 mSv. We conclude that the combination of metabolic information and MRI morphology at a low radiation dose proposes PET/MR as a suitable imaging modality for AE assessment. Longitudinal studies are needed to define the role of this imaging modality.

Imaging Aspects of Hepatic Alveolar Echinococcosis: Retrospective Findings of a Surgical Center in Turkey

Radiologists should be aware of the findings of alveolar echinococcosis (AE) due to the diagnostic and management value of imaging. We are attempting to define the most common diagnostic imaging findings of liver AE, along with the prevalence and distribution of those findings. The patients' US, CT, and MRI images were reviewed retrospectively. CT images were acquired with and without the administration of contrast medium. The MRI protocol includes T2-weighted images (WI), diffusion (WI), apparent diffusion coefficient (ADC) maps, and pre- and post-contrast T1WIs. The current study included 61 patients. The mean age of the population was 58.2 ± 9.6 years According to Kratzer's categorization (US), 139 lesions (73.1%) were categorized as hailstorm. According to Graeter's classification (CT), 139 (73.1%) lesions were type 1-diffuse infiltrating. The most frequent types were Kodama type 2 and 3 lesions (MRI) (42.6% and 48.7%, accordingly). P2N0M0 was the most frequent subtype. The current study defines the major, characteristic imaging findings of liver AE using US, CT, and MRI. Since US, CT, and MRI have all been utilized to diagnose AE, we believe that a multi-modality classification system is needed. The study's findings may aid radiologists in accurately and timely diagnosing liver AE.

Effectiveness and safety of ultrasound-guided percutaneous microwave ablation for hepatic alveolar echinococcosis

Background

Microwave ablation (MWA) is a popular therapy for liver malignant tumor in recent years. Few studies have been conducted on its use in the treatment of hepatic alveolar echinococcosis (HAE). The study aims to evaluate the efficacy and safety of MWA in the treatment of HAE.

Methods

This study analyzed the data of 45 patients (mean age, 38 ± 2 years; 24 males) diagnosed with HAE and underwent MWA treatment between June 2014 to December 2019. The patients after MWA were examined by CT or MRI [follow-up: 32 months (IQR 23–48.5)] to determine whether the lesions were relapsed and to evaluate the therapeutic effect of MWA. The safety of MWA was evaluated by monitoring postoperative complications. Clinical data, such as patient demographics, imaging features of the lesions, relevant findings of laboratory tests before and after ablation, and information related to ablation, were collected and analyzed. Paired-sample t tests and paired-sample Wilcoxon signed-rank tests were used to compare relevant laboratory indicators before and after MWA.

Results

MWA was applied to 57 HAE lesions in 45 patients. The median size of lesions was 3.42 cm (IQR2.85–4.41). The rate of complete ablation was 100% (57/57). The median follow-up time was 32 months (IQR 23–48.5). The recurrence rate was 13% (6/45), and the median time of recurrence was 22 months. The rate of minor complications was 11.1% (5/45), and there were no major complications and deaths. Compared to preoperative, ALB, RBC, HBG, and PLT were decreased (p < 0.001); ALT, TB, DB, and WBC were increased (p < 0.001); and no statistically difference in PT, APTT, and INR (p > 0.05).

Conclusions

MWA might be a safe and effective way to cure HAE. Meanwhile, it provides a new option and a new way of thinking about treatment for patients with HAE.

Stage-Oriented CT Classification and Intermodal Evolution Model in Hepatic Alveolar Echinococcosis

Background

Alveolar echinococcosis (AE) is one of the most dangerous human parasitoses. The main site of disease manifestation is the liver (about 98 %). The Echinococcus Multilocularis Ulm Classification for Computed Tomography (EMUC-CT), presented in 2016, was the first compilation of CT morphological criteria of hepatic AE. Studies based on EMUC-CT made it possible to draw conclusions about the development of the lesions in the course of disease beyond purely diagnostic typing. Among the most important findings of these precursor studies was that EMUC-CT type IV presented as an initial lesion, whereas EMUC-CT type III lesions were mostly associated with an advanced disease constellation. An intermodal view of image morphological criteria provides further multi-layered indications for lesion evolution.

Method

With the “Alveolar Echinococcosis Ulm Classification” (AEUC), a revision of the previous EMUC-CT was carried out with stage-oriented reorganization of the primary morphologies. Furthermore, an intermodal classification scheme for the evolution of hepatic AE lesions based on AEUC, MRI Kodama classification, and aspects of ultrasound could be outlined.

Results

The first stage-oriented CT classification of hepatic AE “AEUC” is based with respect to its lesion characterization on the separate consideration of two classification pillars, the five “primary morphologies”, AEUC I–V (AEUC II–IV with subcriteria) and the five “patterns of calcification”. In addition, an intermodal classification scheme presents five stages of lesion evolution: “initial stage”, “progressive stage”, “advanced stage”, “transitional stage” and “regressive stage”.

Conclusion

The imaging modalities differ with respect to their visualization of lesion criteria. This underlines the need for unimodal classification systems. Staging of an AE lesion can be done more accurately by evaluating different modalities.

Key Points:

Citation Format

Advances in the treatment, diagnosis, control and scientific understanding of taeniid cestode parasite infections over the past 50 years

In the past 50 years, enormous progress has been made in the diagnosis, treatment and control of taeniid cestode infections/diseases and in the scientific understanding thereof. Most interest in this group of parasites stems from the serious diseases that they cause in humans. It is through this lens that we summarize here the most important breakthroughs that have made a difference to the treatment of human diseases caused by these parasites, reduction in transmission of the taeniid species associated with human disease, or understanding of the parasites' biology likely to impact diagnosis or treatment in the foreseeable future. Key topics discussed are the introduction of anti-cestode drugs, including benzimidazoles and praziquantel, and the development of new imaging modalities that have transformed the diagnosis and post-treatment monitoring of human echinococcoses and neurocysticercosis. The availability of new anti-cestode drugs for use in dogs and a detailed understanding of the transmission dynamics of Echinococcus granulosus sensu lato have underpinned successful programs that have eliminated cystic echinococcosis in some areas of the world and greatly reduced the incidence of infection in others. Despite these successes, cystic and alveolar echinococcosis and neurocysticercosis continue to be prevalent in many parts of the world, requiring new or renewed efforts to prevent the associated taeniid infections. Major advances made in the development of practical vaccines against E. granulosus and Taenia solium will hopefully assist in this endeavour, as might the understanding of the parasites' biology that have come from an elucidation of the nuclear genomes of each of the most important taeniid species causing human diseases.

Kodama-XUUB: an informative classification for alveolar echinococcosis hepatic lesions on magnetic resonance imaging

Objective: To propose a modification of the Kodama classification to classify type III lesions of alveolar echinococcosis (AE) that do not have microcysts. Materials and Methods: 200 magnetic resonance imaging (MRI) images of AE liver lesions from four endemic regions of the world were classified according to Kodama, distinguishing within type III those with microcysts from those without. Each center included 50 MRIs of patients with unoperated AA liver lesions. The first 50 cases were classified by a first reader in the presence of four second-line readers from each region. Then each second-line reader classified his or her 50 cases. Results: In all centers, type III lesions were predominant: 58% of the total lesions and 23% of them were without microcysts. The average age of the patients was 47 years. In China, the patients were on average younger and the lesions larger. German patients had more lesions within the liver. Type I and II lesions, synonymous with earlier diagnosis, were more common in Europe. Conclusion: The Kodama classification needed to be modified because of the existence of a significant proportion of unclassifiable lesions. This is especially true since the presence of microcysts is an informative element of parasite activity. Therefore, this study proposes a Kodama-XUUB classification with type IIIa lesions having microcysts and type IIIb lesions not having microcysts.

Hepatic Alveolar Echinococcosis

Hepatic alveolar echinococcosis (HAE) is a rare but severe zoonosis caused by the pseudotumoral intrahepatic development of the larval stage of the tapeworm Echinococcus multilocularis. HAE is present only in the Northern Hemisphere, predominantly in China. Currently, there is a significant resurgence of cases in historically endemic areas associated with emergence of HAE in countries not previously concerned. Today, in European countries, HAE is often discovered by chance; however, clinicians should be made aware of opportunistic infections that progressively emerged recently as a result of therapeutic or pathological immunosuppression. Ultrasonography is the key first-line diagnostic procedure, with specific serology providing confirmation in 95% of the cases. Albendazole, only parasitostatic, is the mainstay for treatment. Surgical resection, if feasible, is the gold standard for treatment, and more patients are currently eligible for this option because of an earlier diagnosis. The prognosis has considerably improved but remains poor in countries where access to care is less favorable.

Quantitative evaluation of range and metabolic activity of hepatic alveolar echinococcosis lesion microenvironment using PET/CT and multi-site sampling method

Background

Alveolar echinococcosis (AE) lesion microenvironment (LME) is crucial site where parasite-host interactions happen and of great significance during surgery and obtaining liver samples for basic research. However, little is known about quantification of LME range and its’ metabolic activity regarding different lesion characteristics.

Methods

A prospective and retrospective analysis of LME from surgical AE patients was performed. Patients (n = 75) received abdominal computed tomography (CT) and position emission tomography/computed tomography using ¹⁸F-fluodeoxyglucose (¹⁸F-FDG-PET/CT) within 1 week prior to surgery. Semiquantitatively, calcification was clustered with 0%, < 50% and ≥ 50% degrees at lesion periphery; liquefaction was clustered with 0%, < 50%, 50 ~ 75%, ≥75% degrees at lesion center using volumetric ratio. Tumor to background ratio (TBR) of ¹⁸F-FDG standard uptake value (SUV, n = 75) was calculated, and range of ¹⁸F-FDG uptake area was measured; Multi-site sampling method (MSS, n = 35) was introduced to obtain histological slides to evaluate immune cell infiltrative ranges.

Results

Altogether six major lesion groups have been identified (A: 0% calcified, 0% liquefied; B: ≥50% calcified, 0% liquefied; C: < 50% calcified, < 50% liquefied; D: ≥50% calcified, < 50% liquefied; E: < 50% calcified, 50 ~ 75% liquefied; F: ≥50% calcified, ≥75% liquefied). Statistically, TBR values respectively were 5.1 ± 1.9, 2.7 ± 1.2, 4.2 ± 1.2, 2.7 ± 0.7, 4.6 ± 1.2, 2.9 ± 1.1 in groups A ~ F, and comparisons showed A > B, A > D, A > F, E > B, E > D, E > F, C > B, C > D, C > F (P < 0.05); LME ranges indicated by PET/CT respectively were 14.9 ± 3.9, 10.6 ± 1.5, 12.3 ± 1.1, 7.8 ± 1.6, 11.1 ± 2.3, 7.0 ± 0.4 mm in groups A ~ F, and comparisons showed A > B, A > D, A > F, A > E, C > B, C > D, C > F, E > D, E > F, B > D, B > F (P < 0.05); LME ranges indicated by MSS respectively were 17.9 ± 4.9, 13.0 ± 2.7, 11.9 ± 2.6, 6.0 ± 2.2, 11.0 ± 4.1, 6.0 ± 2.2 mm in groups A ~ F, and comparisons showed A > C, A > D, A > F, B > D, B > F, C > D, C > F (P < 0.05). Generally, less calcifications indicated higher TBR values and wider LME ranges; and, severer liquefactions indicated smaller LME ranges. Additionally, patients with previous medication history had lower TBR values.

Conclusions

PET/CT and MSS method showed distinct TBRs and LME ranges for different calcifications and liquefactions. This study would be able to provide references for both surgical resections of lesions and more accurate sample acquisitions for basic research targeted to immunology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06366-3.

Parasites of the liver - epidemiology, diagnosis and clinical management in the European context

Parasites in the liver cause significant global morbidity and mortality, as they can lead to recurrent cholangitis, cirrhosis, liver failure and cancer. Due to climate change and globalisation, their incidence is increasing, especially in Europe. The correct diagnosis of a hepatic parasite is often delayed because clinicians are unfamiliar with respective entities. Therefore, in this review, we aim to provide clinicians with a comprehensive clinical picture of hepatic parasites and to bring these neglected parasitic liver diseases to the wider attention of hepatology stakeholders in Europe and around the world.

A Case of Human Hepatic Alveolar Echinococcosis Accompanied by Lung and Brain Metastases

Alveolar echinococcosis (AE) is considered as a fatal zoonosis caused by the larvae of Echinococcus multilocularis. The lungs and brain are the most common metastatic organs. We report a human case of hepatic alveolar echinococcosis accompanied by lung and brain metastasis. In particular, the patient had a history of tuberculosis and the lung lesions were easily misdiagnosed as lung abscesses. The lesions of liver and lung underwent radical resection and confirmed as alveolar echinococcosis by pathological examination. The patient had no surgical complications after operation and was discharged after symptomatic treatment. Unfortunately, the patient later developed multiple intracerebral AE metastases. We required the patient to take albendazole orally for life and follow up.

Hepatic Alveolar Echinococcosis: Predictive Biological Activity Based on Radiomics of MRI

BACKGROUND

To evaluate the role of radiomics based on magnetic resonance imaging (MRI) in the biological activity of hepatic alveolar echinococcosis (HAE).

METHODS

In this study, 90 active and 46 inactive cases of HAE patients were analyzed retrospectively. All the subjects underwent MRI and positron emission tomography computed tomography (PET-CT) before surgery. A total of 1409 three-dimensional radiomics features were extracted from the T2-weighted MR images (T2WI). The inactive group in the training cohort was balanced via the synthetic minority oversampling technique (SMOTE) method. The least absolute shrinkage and selection operator (LASSO) regression method was used for feature selection. The machine learning (ML) classifiers were logistic regression (LR), multilayer perceptron (MLP), and support vector machine (SVM). We used a fivefold cross-validation strategy in the training cohorts. The classification performance of the radiomics signature was evaluated using receiver operating characteristic curve (ROC) analysis in the training and test cohorts.

RESULTS

The radiomics features were significantly associated with the biological activity, and 10 features were selected to construct the radiomics model. The best performance of the radiomics model for the biological activity prediction was obtained by MLP (AUC = 0.830 ± 0.053; accuracy = 0.817; sensitivity = 0.822; specificity = 0.811).

CONCLUSIONS

We developed and validated a radiomics model as an adjunct tool to predict the HAE biological activity by combining T2WI images, which achieved results nearly equal to the PET-CT findings.

Emerging human alveolar echinococcosis in Hungary (2003-2018): a retrospective case series analysis from a multi-centre study

Background

Human alveolar echinococcosis (AE) caused by Echinococcus multilocularis is an underreported, often misdiagnosed and mistreated parasitic disease mainly due to its low incidence. The aim of this study was to describe the epidemiological and clinical characteristics of human AE patients in Hungary for the first time.

Method

Between 2003 and 2018, epidemiological and clinical data of suspected AE patients were collected retrospectively from health database management systems.

Results

This case series included a total of 16 AE patients. The mean age of patients was 53 years (range: 24–78 years). The sex ratio was 1:1. Four patients (25%) revealed no recurrence after radical surgery and adjuvant albendazole (ABZ) therapy. For five patients (31.3%) with unresectable lesions, a stabilization of lesions with ABZ treatment was achieved. In seven patients (43.8%), progression of AE was documented. The mean diagnostic delay was 33 months (range: 1–122 months). Three AE related deaths (fatality rate 18.8%) were recorded.

Conclusions

AE is an emerging infectious disease in Hungary with a high fatality rate since based on our results, almost every fifth AE patient died in the study period. Differential diagnosis and appropriate surgical and medical therapy for AE is an urging challenge for clinicians in Hungary, as well as in some other European countries where E. multilocularis is prevalent.

Pulmonary Echinococcosis or Lung Hydatidosis: A Narrative Review

Background: Lung hydatidosis is a zoonosis related to infection by the Echinococcus tapeworm species. Lung involvement in this condition is second only to the liver echinococcosis. Diagnosis ordinarily results from an accidental finding in a direct chest radiograph evaluation because of the delayed growth of the cysts. Moreover, a consistent treatment regimen or approach may not be feasible because of the variability of pulmonary echinococcosis. In this review, we expect to sum up the main features of lung hydatidosis with a perspective on medical and surgical treatment. Methods: Cochrane Library and PubMed were the databases used to perform a narrative literature review. Search terms included "pulmonary echinococcosis" and "lung hydatidosis." The MeSH terms were "lung" [All Fields] AND {"echinococcosis" [MeSH Terms] OR ("hydatidosis" [All Fields] OR "pulmonary" [All Fields] AND "echinococcosis" [All Fields] OR "hydatidosis." A search period from September 1980 to May 2020 was chosen to compare studies from different decades, given the changes in pulmonary echinococcosis management. Results: A uniform treatment regimen or approach may not be feasible because of the variability of pulmonary echinococcosis. No clinical trials have analyzed and compared all the diverse treatment approaches. Cyst size, characteristics, position in the lung and clinical presentation, and the availability of medical/surgical expertise and equipment are the mainstays of echinococcosis management. When feasible, surgery is as yet the principal therapeutic choice to eliminate the cysts; anti-parasitic drugs may minimize complications during high-risk surgery or be used as definitive therapy in some instances with contraindications to surgery. Conclusions: Lung hydatidosis management must become less heterogeneous. We support treatment directed to the subject established on the clinical scenario, host factors, and surgical risk. Strict cooperation in this process between infectious disease specialists and surgeons may optimize best practices to help create shared practical guidelines to simplify clinicians' decision-making. Furthermore, we need a consensus for lung hydatidosis treatment and inserting this disease to global surgery agenda will have a positive impact on acquiring high-quality data that enables us to create an evidence-based guideline for this disease.

The spectrum of multimodality imaging findings in hepatic alveolar echinococcosis and the potential role of diffusion-weighted imaging in its characterisation

Purpose

To study the spectrum of imaging findings in hepatic alveolar echinococcosis (HAE) and to evaluate the potential role of diffusion-weighted imaging (DWI) in its characterisation.

Material and methods

Two radiologists with more than seven years of experience retrospectively studied ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) findings in 23 histopathologically proven cases of HAE with emphasis on the appearance and extent of disease. DWI characteristics of lesions were noted, and their apparent diffusion values (ADC) were calculated.

Results

Ultrasonography features of HAE included heterogeneous, hyperechoic hepatic mass with or without calcification (n = 20), or heterogeneous mass with solid-cystic appearance (n = 2). CT revealed heterogeneous density infiltrative hepatic mass with no contrast enhancement in 19 patients or thick-walled cystic mass (n = 4). Following Kodama classification one type 1, six type 2, two type 3, eight type 4, and two type 5 lesions were identified on T2-weighted MRI. No enhancement was seen on post-contrast T1-weighted images. Mean ADC values were 1.74 ± 0.48 × 10^-3 mm²/s (range: 1.39 × 10^-3 mm²/s to 2.3 × 10^-3 mm²/s).

Conclusions

HAE by virtue of its infiltrative growth pattern with a tendency to involve biliary, vascular, and extra hepatic structures can be easily misdiagnosed as malignant hepatic neoplasm. Knowledge of varied imaging appearances of HAE is essential to suspect the condition and to make an appropriate diagnosis. Diffusion-weighted imaging is a useful adjunct with relatively high diffusivity (high ADC values) suggesting diagnosis of alveolar hydatid.

Fast-Growing Alveolar Echinococcosis Following Lung Transplantation

Alveolar echinococcosis is a rare but life-threatening infection caused by the parasite Echinococcus multilocularis. Its natural history is characterized by a slow parasitic growth over several years. Increased incidence and shorter development delay have been reported in immune-compromised patients. We report the reactivation of aborted lesions within 12 months of lung transplantation leading to a fast-growing aggressive hepatic lesion. Timely identification of alveolar echninococcosis allowed prompt albendazole treatment and radical surgery leading to a favorable outcome 42 months after transplantation. However, close clinical, serological and radiological monitoring is required to rule out relapses in the long term. The pre-existence of aborted self-limited lesions of alveolar echinococcosis and the possibility for their atypical rapid growth in patients undergoing profound immunosuppression should be known by healthcare providers, even if working in non-endemic areas.

Evaluation of intrahepatic manifestation and distant extrahepatic disease in alveolar echinococcosis

BACKGROUND

The main endemic areas of alveolar echinococcosis (AE) are in Central Europe and Western China. Both the infiltration of intrahepatic vascular and bile duct structures as well as extrahepatic disease can lead to further complications and may increase morbidity in patients with AE.

AIM

To evaluate vascular/biliary involvement in hepatic AE and its distant extrahepatic disease manifestations in an international collective was the aim.

METHODS

Consecutively, five experienced examiners evaluated contrast-enhanced abdominal computed tomography (CT) scans for 200 patients with hepatic AE of each of four locations (n = 50) in Germany, France and China. Therefore, we retrospectively included the 50 most recent abdominal contrast-enhanced CT examinations at each center, performed because of hepatic AE from September 21, 2007 to March 21, 2018. AE liver lesions were classified according to the echinococcosis multilocularis Ulm classification for CT (EMUC-CT). Distant extrahepatic manifestations were documented either by whole body positron emission tomography–CT or with the addition of thoracic CT and cranial magnetic resonance imaging. Vascular/biliary involvement of the hepatic disease as well as the presence of distant extrahepatic manifestations were correlated with the EMUC-CT types of liver lesion. Statistical analysis was performed using SAS Version 9.4 (SAS Institute Inc., Cary, NC, United States).

RESULTS

Distant extrahepatic AE manifestations were significantly more frequent in China than in Europe (P = 0.0091). A significant relationship was found between the presence of distant extrahepatic disease and AE liver lesion size (P = 0.0075). Vascular/biliary structures were involved by the liver lesions significantly more frequently in China than in Europe (P < 0.0001), and vascular/biliary involvement depended on lesion size. Different morphological types of AE liver lesions led to varying frequencies of vascular/biliary involvement and were associated with different frequencies of distant extrahepatic manifestations: Vascular/biliary involvement as a function of lesions primary morphology ranged from 5.88% of type IV liver lesions to 100% among type III lesions. Type IV differed significantly in these associations from types I, II, and III (P < 0.0001). With respect to extrahepatic disease, the primary morphology types IV and V of liver lesions were not associated with any case of distant extrahepatic disease. In contrast, distant extrahepatic manifestations in types I–III were found to varying degrees, with a maximum of 22% for type III.

CONCLUSION

Different CT morphological patterns of hepatic AE lesions influence vascular/biliary involvement and the occurrence of distant extrahepatic manifestations. There are intercontinental differences regarding the characteristics of AE manifestation.

Combining Computed Tomography and Histology Leads to an Evolutionary Concept of Hepatic Alveolar Echinococcosis

Alveolar echinococcosis (AE) is caused by the intermediate stage of Echinococcus multilocularis. We aimed to correlate computed tomography (CT) data with histology to identify distinct characteristics for different lesion types. We classified 45 samples into five types with the Echinococcus multilocularis Ulm Classification for Computed Tomography (EMUC-CT). The various CT lesions exhibited significantly different histological parameters, which led us to propose a progression model. The initial lesion fit the CT type IV classification, which comprises a single necrotic area with the central located laminated layer, a larger distance between laminated layer and border zone, a small fibrotic peripheral zone, and few small particles of Echinococcus multilocularis (spems). Lesions could progress through CT types I, II, and III, characterized by shorter distances between laminated layer and border zone, more spems inside and surrounding the lesion, and a pronounced fibrotic rim (mostly in type III). Alternatively, lesions could converge to a highly calcified, regressive state (type V). Our results suggest that the CT types mark sequential stages of the infection, which progress over time. These distinct histological patterns advance the understanding of interactions between AE and human host; moreover, they might become prognostically and therapeutically relevant.

Hepatic alveolar echinococcosis: correlation between computed tomography morphology and inflammatory activity in positron emission tomography

Positron emission tomography-computed tomography (PET-CT) with 18F-fluorodesoxyglucose (FDG) is the imaging modality of choice for assessing inflammation surrounding hepatic alveolar echinococcosis (AE) lesions. This study is the first to evaluate FDG uptake in hepatic AE (n = 51) based on the standardized uptake value (SUV) and to correlate the SUVs with primary morphology and calcification patterns, based on the Echinococcus multilocularis Ulm Classification for Computed-Tomography (EMUC-CT). Our results show that the SUVs were increased for lesions with EMUC-CT types I-IV primary morphology, compared to the surrounding healthy liver tissue (SUV = 2.5 ± 0.4; p < 0.05). Type IV lesions included, by far, the highest number of PET-negative lesions. A comparison of lesions with different primary morphologies showed clear differences. The highest SUVs were found for types I and III, and the lowest was found for type IV. Type IV lesions (SUV, 3.8 ± 1.5) showed significantly lower uptake compared to type I (SUV, 6.9 ± 3.5; p = 0.030) and type III (SUV, 7.4 ± 3.9; p = 0.031) lesions. For type II lesions, the results showed only a statistical trend (SUV, 6.1 ± 3.1; p = 0.073). Due to the small number of cases, an evaluation of type V (n = 1) lesions was not possible. The different SUVs of lesions with different primary morphologies, particularly the lower FDG uptake observed in type IV lesions, suggested that these SUVs might reflect different stages of the disease.

International consensus on terminology to be used in the field of echinococcoses

Echinococcoses require the involvement of specialists from nearly all disciplines; standardization of the terminology used in the field is thus crucial. To harmonize echinococcosis terminology on sound scientific and linguistic grounds, the World Association of Echinococcosis launched a Formal Consensus process. Under the coordination of a Steering and Writing Group (SWG), a Consultation and Rating Group (CRG) had the main missions of (1) providing input on the list of terms drafted by the SWG, taking into account the available literature and the participants’ experience; and (2) providing independent rating on all debated terms submitted to vote. The mission of the Reading and Review Group (RRG) was to give an opinion about the recommendation paper in terms of readability, acceptability and applicability. The main achievements of this process were: (1) an update of the current nomenclature of Echinococcus spp.; (2) an agreement on three names of diseases due to Echinococcus spp.: Cystic Echinococcosis (CE), Alveolar Echinococcosis (AE) and Neotropical Echinococcosis (NE), and the exclusion of all other names; (3) an agreement on the restricted use of the adjective “hydatid” to refer to the cyst and fluid due to E. granulosus sensu lato; and (4) an agreement on a standardized description of the surgical operations for CE, according to the “Approach, cyst Opening, Resection, and Completeness” (AORC) framework. In addition, 95 “approved” and 60 “rejected” terms were listed. The recommendations provided in this paper will be applicable to scientific publications in English and communication with professionals. They will be used for translation into other languages spoken in endemic countries.

Hepatic alveolar echinococcosis: Comparative computed tomography study between two Chinese and two European centres

The main endemic areas for alveolar echinococcosis (AE) are in Central Europe and Western China, and in >98% of cases, AE manifests in the liver. The aim of this work was to compare European and Chinese patient groups for number, size, and computed tomography (CT) appearance of hepatic AE lesions. A total of 200 CT scans of patients with hepatic AE were evaluated by four blinded, experienced radiologists from two European (Besancon, Ulm) and two Chinese centres (Xining, Urumqi). In addition to noting the number, size, and localisation of the lesions, the radiologists evaluated morphological appearance using the Echinococcus multilocularis Ulm Classification - CT scheme. Chinese patients were younger than European patients (36.8 ± 13.2 vs. 63.5 ± 17.7; p < 0.0001) and had significantly larger lesions (120.4 ± 50.8 vs. 70.9 ± 39.8; p < 0.0001). The morphological appearance of the lesions on CT differed significantly between the two groups (p < 0.05), as did the number of lesions (2.6 ± 3.9 in European centres versus 3.8 ± 5.0 in Chinese centres; p = 0.0062). Patient age and AE-related morphological manifestations differ between Europe and China, but the reasons for the differences are unknown.

Pathology of Echinococcosis: A Morphologic and Immunohistochemical Study on 138 Specimens With Focus on the Differential Diagnosis Between Cystic and Alveolar Echinococcosis

Infection of humans by the larval stage of the tapeworms Echinococcus granulosus sensu lato or Echinococcus multilocularis causes the life-threatening zoonoses cystic echinococcosis (CE) and alveolar echinococcosis (AE). Although cystic liver lesions are a hallmark of both diseases, course, prognosis, and patients' management decisively differ between the two. The wide and overlapping spectrum of morphologies and the limited availability of ancillary tools are challenges for pathologists to reliably diagnose and subtype echinococcosis. Here, we systematically and quantitatively recorded the pathologic spectrum in a clinically and molecularly defined echinococcosis cohort (138 specimens from 112 patients). Immunohistochemistry using a novel monoclonal antibody (mAbEmG3) was implemented, including its combined application with the mAbEm2G11. Six morphologic criteria sufficiently discriminated between CE and AE: size of smallest (CE/AE: >2/≤2 mm) and largest cyst (CE/AE: >25/≤25 mm), thickness of laminated layer (CE/AE: >0.15/≤0.15 mm) and pericystic fibrosis (CE/AE: >0.6/≤0.6 mm), striation of laminated layer (CE/AE: moderate-strong/weak), and number of cysts (CE/AE: ≤9/>9). Combined immunohistochemistry with mAbEm2G11 (E. multilocularis specific) and mAbEmG3 (reactive in AE and CE) was equally specific as and occasionally more sensitive than polymerase chain reaction. On the basis of these findings, we developed a diagnostic algorithm for the differential diagnosis of echinococcosis. In summary, we have not only identified the means to diagnose echinococcosis with greater certainty, but also defined morphologic criteria, which robustly discriminate between CE and AE. We expect our findings to improve echinococcosis diagnostics, especially of challenging cases, beneficially impacting the management of echinococcosis patients.

The usefulness of commercially available serological tests in the diagnosis and monitoring of treatment in patients with alveolar echinococcosis

Aim of the study

To assess the clinical usefulness of serological tests in the diagnosis and monitoring of treatment of patients with alveolar echinococcosis (AE).

Material and methods

The results of serological tests, i.e. Echinococcus multilocularis ELISA (Bordier Affinity Products) and Echinococcus Western Blot IgG (LDBIO Diagnostic), of 66 patients were analysed. Duration of follow-up was two years after diagnosis. In the second phase of the study 11 sera obtained from the patients undergoing surgical treatment, in whom the results of Echinococcus Western Blot IgG assay were still positive, were additionally tested with Anti-Echinococcus EUROLINE-WB (IgG) assay.

Results

Statistically significant negativization of the Echinococcus multilocularis ELISA test was observed in the group of patients who underwent radical surgery or liver transplantation. Negativization of Echinococcus Western Blot IgG assay results was observed in some patients, among both those who received conservative treatment and those who underwent surgery, but no statistically significant differences were found between treatment groups. In 54.5% of cases the Anti-Echinococcus EUROLINE-WB (IgG) test result was negative when the results of the Echinococcus Western Blot IgG assay were still positive.

Conclusions

Echinococcus multilocularis ELISA proved to be useful in assessing the activity of AE in a group of patients who underwent radical surgery or liver transplantation. The results of our study suggest that Anti-Echinococcus EUROLINE-WB (IgG) is a more dynamic test, which at the time of disappearance of AE activity becomes negative earlier.

Ultrasound images in hepatic alveolar echinococcosis and clinical stage of the disease

PURPOSE

Hepatic alveolar echinococcosis (AE) is a parasitic disease caused by the larval stage of the tapeworm Echinococcus multilocularis. Ultrasonography is the method of choice in the initial diagnosis of AE. The aim of the study is to present the most frequent sonomorphological patterns of lesions in hepatic AE based on the analysis of ultrasound findings in patients treated for AE at the University Centre of Maritime and Tropical Medicine (UCMMiT; Gdynia, Poland), and to establish whether there is a relationship between the clinical stage of AE and the occurrence of a specific sonomorphological pattern of hepatic lesions.

PATIENTS AND METHODS

We analysed the results of ultrasound examinations of 58 patients hospitalized in the UCMMiT with probable or certain diagnosis of AE. Liver lesions were assessed according to the classification developed by researchers from the University Hospital in Ulm (Germany). Statistical analysis was based on the relationship between the occurrence of a specific sonomorphological pattern of hepatic lesions and the clinical stage of AE.

RESULTS

The most frequently observed patterns of AE lesions in the liver were the hailstorm and the pseudocystic patterns. There was no correlation between the clinical stage of the disease and the ultrasonographic appearance of lesions. There was no statistically significant relationship between the more frequent occurrences of specific ultrasonographic patterns of lesions in the liver and radical or non-radical surgery.

CONCLUSIONS

The ultrasonographic appearance of the lesion in liver AE cannot determine the therapeutic management. Treatment plan should be established based on the PMN classification.

Surgery versus conservative drug therapy in alveolar echinococcosis patients in Germany - A health-related quality of life comparison

Alveolar echinococcosis (AE) is a rare zoonosis caused by the parasite Echinococcus multilocularis. Nothing is known about the health-related quality of life (HRQoL) in patients with AE receiving different types of therapy. Therefore, the aim of the study was to compare HRQoL in patients with AE in Germany depending on their therapeutic regimen namely conservative drug treatment with long-term benzimidazoles versus surgical therapy by resection of the parasitic liver lesions. The 36-Item Short Form Health Survey (SF-36) questionnaire, including other echinococcosis-related questions, was used to measure HRQoL. The SF-36 scales were evaluated according to the algorithms provided by the authors. The statistical analysis was performed with SAS version 9.2. The significance level was set at α = 0.05, p < 0.05 corresponds to statistical significance. The investigated group consisted of conservatively drug treated (n = 30) and patients with curative surgery (n = 25) with confirmed AE. The study was performed at an infectious disease outpatient department from April 2018 to October 2018. The conservatively drug treated patient group consisted of 15 men (50.0%) and 15 women (50.0%) with an average age of 55.7 ± 16.7 years (Median: 59). The surgery group consisted of nine men (36.0%) and 16 women (64.3%) with an average age of 53.3 ± 31.9 years (Median: 54). The physical quality of life of the conservatively drug treated patients did not show any significant differences to the surgical treated group (45.2 ± 11.4 vs. 47.6 ± 9.9; p = 0.4079). There was also no significant difference regarding the mental quality of life between the conservatively drug treated patients, and those treated with curative surgery (45.5 ± 10.6 vs. 47.3 ± 10.8; 0.5206). Nevertheless, there was a slight advantage in the physical and mental scores of the patients treated with surgery. Furthermore, for 13 of the 25 surgically treated patients, some aspects of the HRQoL improved significantly after surgery. The evaluation showed no statistically significant differences in HRQoL in patients with AE dependent on the applied treatment strategy (conservative drug versus curative surgical therapy).

Simple liver cysts and cystoid lesions in hepatic alveolar echinococcosis: a retrospective cohort study with Hounsfield analysis

BACKGROUND

Alveolar echinococcosis (AE) is a rare zoonosis caused by the larval stage of the tapeworm Echinococcus multilocularis. AE lesions affect the liver in more than 98% of cases. AE lesions have various morphological characteristics that are described in the Echinococcus multilocularis Ulm classification for computed tomography (EMUC-CT). One of these characteristics is a cystoid portion. The aim of the study was to compare the density of simple hepatic cysts with cystoid portions of AE lesions classified on the basis of the EMUC-CT.

RESULTS

Hounsfield Unit (HU) measurements of the cystoid portions of all EMUC-CT type I-IV AE lesions (n = 155) gave a mean of 21.8 ± 17.6, which was significantly different from that of 2.9 ± 4.5 for the simple hepatic cysts (p < 0.0001). The difference between each of the individual AE types and simple hepatic cysts was also significant. In addition, the HU values of the cystoid portions in types I, II and IIIa/b and simple cysts were each significantly different from type IV (p < 0.0001). The HU measurements in type IV presented by far the highest mean.

CONCLUSIONS

The significantly higher density measured in the cystoid portions of hepatic AE lesions offers a good means of differentiation from simple hepatic cysts.

AE hepatic lesions: correlation between calcifications at CT and FDG-PET/CT metabolic activity

PURPOSE

To correlate the presence of calcifications in alveolar echinococcosis (AE) hepatic lesions to the metabolic activity in 18 fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT).

METHODS

Our institutional review board approved this study. 61 patients (29 women, 32 men, aged from 15 to 86 years) were included in the study. Images of FDG-PET/CT were interpreted by two independent nuclear medicine physicians. AE hepatic lesions were classified as AE lesions with or without hypermetabolic activity. The presence of calcifications was assessed on unenhanced CT scans by two independent radiologists blinded with regard to the metabolic activity of the AE hepatic lesions. Every single calcification the size of which was < 3 mm and non-measurable calcifications which were forming areas with a powdery appearance were considered as microcalcifications. All other types of calcifications were reported as macrocalcifications. Statistical analysis was performed and p value < 0.05 was considered as statistically significant.

RESULTS

Microcalcifications and macrocalcifications were present at CT in 95% (58/61) AE hepatic lesions and 43% (26/61) AE hepatic lesions, respectively. Hypermetabolic activity was present at FDG-PET/CT in 93% (57/61) AE hepatic lesions. 98% (56/57) of the AE hepatic lesions presenting with hypermetabolic activity at FDG-PET/CT showed microcalcifications at CT (p = 0.01) when only 40% (23/57) showed macrocalcifications at CT (p = 0.3). 100% (23/23) of the AE hepatic lesions with hypermetabolic activity at FDG-PET/CT and macrocalcifications at CT showed also microcalcifications at CT.

CONCLUSIONS

Hypermetabolic activity of AE hepatic lesions at FDG-PET/CT is strongly correlated to the presence of microcalcifications at CT, independently of the presence of macrocalcifications.

FDG-PET/MRI imaging for the management of alveolar echinococcosis: initial clinical experience at a reference centre in Austria

BACKGROUND

[¹⁸ F]-2-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (FDG-PET/CT) imaging provides important information about the size and metabolic activity of lesions caused by Echinococcus multilocularis and is therefore recommended for the initial assessment and follow-up of human alveolar echinococcosis (AE). The introduction of positron emission tomography/magnetic resonance imaging (PET/MRI) into clinical practice in affluent health care systems provides an alternative dual imaging modality, which has not yet been evaluated for AE.

OBJECTIVE

Here, we describe the initial clinical experience with comparative PET/CT and PET/MR imaging in four human AE patients at an Austrian reference centre.

RESULTS

PET/MR imaging showed comparable diagnostic capacity for liver lesions attributable to E. multilocularis infection, with a discrepancy only in the assessment of calcifications in one patient. Effective doses of radiation were 30.4-31 mSV for PET/CT, which were reduced in PET/MRI to the exposure of ¹⁸ F-FDG only (4.9-5.5 mSv).

CONCLUSIONS

PET/MRI provides comparable diagnostic information for AE management. The reduction in radiation exposure compared to PET/CT may be of particular importance for children and young patients not amenable for curative surgery requiring repeated long-term follow-up with dual imaging modalities. Further studies are warranted to prospectively evaluate the potential of PET/MRI in the management of AE.

Echinococcosis: Advances in the 21st Century

Echinococcosis is a zoonosis caused by cestodes of the genus Echinococcus (family Taeniidae). This serious and near-cosmopolitan disease continues to be a significant public health issue, with western China being the area of highest endemicity for both the cystic (CE) and alveolar (AE) forms of echinococcosis. Considerable advances have been made in the 21st century on the genetics, genomics, and molecular epidemiology of the causative parasites, on diagnostic tools, and on treatment techniques and control strategies, including the development and deployment of vaccines. In terms of surgery, new procedures have superseded traditional techniques, and total cystectomy in CE, ex vivo resection with autotransplantation in AE, and percutaneous and perendoscopic procedures in both diseases have improved treatment efficacy and the quality of life of patients. In this review, we summarize recent progress on the biology, epidemiology, diagnosis, management, control, and prevention of CE and AE. Currently there is no alternative drug to albendazole to treat echinococcosis, and new compounds are required urgently. Recently acquired genomic and proteomic information can provide a platform for improving diagnosis and for finding new drug and vaccine targets, with direct impact in the future on the control of echinococcosis, which continues to be a global challenge.

Hepatic alveolar hydatid disease (Echinococcus multilocularis), a mimic of liver malignancy: a review for the radiologist in non-endemic areas

Alveolar hydatid disease or alveolar echinococcosis (AE) is caused by the parasite Echinococcus multilocularis and is increasingly seen as an imported disease in non-endemic areas such as the UK. It is rare compared to cystic echinococcosis (CE), but like CE commonly affects the liver. AE does have imaging features that can aid in diagnosis, but is often initially misdiagnosed as liver malignancy. It is usually fatal if untreated, underscoring the importance of early diagnosis. This review highlights the role of imaging in AE diagnosis with the broader objective of increasing radiologists' awareness of this unusual, but increasingly prevalent disease.

Doughnut sign of hepatic alveolar echinococcosis on FDG PET/CT: Clinical case report

RATIONALE

A characteristic metabolic finding of hepatic alveolar echinococcosis (HAE) on positron emission tomography/computed tomography (PET/CT) correlates with morphologic features on CT and magnetic resonance imaging (MRI).

PATIENT CONCERNS

A young man from an endemic area was admitted to our hospital due to right upper quadrant pain for 2 months.

DIAGNOSIS

CT and MRI revealed a heterogeneous mass with calcification, consisting of central necrosis and peripheral solid inflammatory tissues. Accordingly, FDG PET/CT demonstrated a characteristic metabolic finding of doughnut sign. Combining the above characteristic imaging features with positive serologic findings, the patient was diagnosed as HAE.

INTERVENTIONS

He then underwent extracorporeal hepatectomy and liver autotransplantation followed by medical treatment of benzimidazoles.

OUTCOMES

He remained asymptomatic without evidence of recurrence at 2-year follow-up.

LESSONS

The characteristic metabolic appearance of HAE on FDG PET/CT, correlated with its morphologic features of CT and MRI, may allow to make accurate diagnoses.

Health-related quality of life in patients with alveolar echinococcosis: a cross-sectional study

PURPOSE

The Alveolar echinococcosis (AE) is a rare zoonosis caused by the parasite Echinococcus multilocularis. To date, nothing is known about the health-related quality of life (HRQoL) in patients with AE. The aim of the study was to evaluate the HRQoL in patients with AE in comparison of the healthy population.

METHODS

We used the 36-Item Short Form Health Survey (SF-36) questionnaire to evaluate the HRQoL. The SF-36 scales have a range of 0-100 (0 represents the worst and 100 the most favourable state of health). SAS Version 9.2 was used for the statistical analysis of AE-cases (n = 30) and the healthy control group (n = 35).

RESULTS

The analysis showed that the HRQoL in people with AE is reduced in comparison with the control population. The study group consisted of 15 (50.0%) men and 15 (50.0%) women; the control group of 16 (45.7%) men and 19 (54.3%) women. The mean age was 55.73 ± 16.65 years, while that of the control group was 54.57 ± 15.34 years. The physical quality of life in patients with AE (45.21 ± 11.42) was not significantly less than that of the control group (50.54 ± 10.52); p = 0.0568. Nevertheless, AE-patients show lower SF-36 scores for the physical quality of life. For the mental quality of life, patients with AE had a significantly lower score (45.46 ± 10.57) than the control group (51.57 ± 9.04); p = 0.0154.

CONCLUSIONS

The HRQoL in people with AE is reduced in comparison with a control population. Assessment of the physical and mental quality of life in patients with AE may help to evaluate the patient outcome.

Surgical approaches to hepatic hydatidosis ranging from partial cystectomy to liver transplantation

Backgrounds/Aims

A wide range of surgical approaches has been described for hepatic hydatidosis aiming primarily at the reduction of disease recurrence and minimization of postoperative morbidity.

Methods

A database analysis of patients with liver hydatidosis who underwent different surgical procedures between March 2010 and May 2016 was performed.

Results

A total of 21 patients with cystic echinococcosis (CE) and four cases of alveolar echinococcosis (AED) were detected. Nine patients manifested recurrent disease at presentation. Among CE cases, 5 underwent partial cystectomy (2 laparoscopic and 3 open), 9 cysto-pericystectomy (7 open and 2 robotic) and 7 hepatectomies (1 central, 4 right, 1 left and 1 right trisectionectomy). Living donor liver transplantation was performed in 3 patients with AED and the fourth patient underwent right trisectionectomy with en bloc resection of hepatic flexure and right diaphragm. Seven developed Clavien grade II and three grade III complications. The mean follow-up of CE was 34.19±19.75 months. One patient of laparoscopic partial cystectomy developed disease recurrence at 14 months. No recurrence was detected at a mean follow-up of 34±4.58 months following LDLT and at 24 months following multivisceral resection for AED.

Conclusions

The whole spectrum of tailored surgical approaches ranging from minimally invasive to open and extended liver resections represents safe, effective and recurrence-free treatment of hepatic hydatidosis.

Performance of Magnetic Resonance Susceptibility-Weighted Imaging for Detection of Calcifications in Patients With Hepatic Echinococcosis

OBJECTIVE

We evaluated the performance of susceptibility-weighted imaging (SWI) for identification of hepatic calcifications in alveolar echinococcosis and cystic echinococcosis.

METHODS

The SWI images of 58 lesions in 40 patients (age, 49 ± 14 y) with alveolar echinococcosis (n = 22) or cystic echinococcosis (n = 18) were reviewed for calcifications. First, calcifications were suggested by visual assessment. Second, ratios of minimum intralesional intensity and mean lumbar muscle intensity were recorded. Computed tomography (CT) served as the criterion standard.

RESULTS

Thirty-seven lesions showed calcifications on CT. Susceptibility-weighted imaging provided a sensitivity of 89.2% (95% confidence interval [CI], 50.1-75.7) and a specificity of 57.1% (95% CI, 34.4-77.4) for calcifications detected by visual assessment. Receiver operating characteristic curves demonstrated a sensitivity of 67.6% and a specificity of 85.0% for an intensity ratio of 0.61. A specificity of 100% (95% CI, 80.8-100) and a sensitivity of 84.5% (95% CI, 67.3-93.2) were achieved by SWI for calcifications with a density greater than 184 HU in CT.

CONCLUSIONS

Identification of hepatic calcifications is possible with SWI. Susceptibility-weighted imaging offers the potential to reduce the need for of CT imaging for evaluation of echinococcosis.