Differential diagnosis between benign and malignant gallbladder diseases with real-time contrast-enhanced ultrasound

Gallbladder polypoid lesions: Current practices and future prospects

ABSTRACT

Gallbladder polypoid lesions (GPLs) refer to any elevated lesion of the mucosal surface of the gallbladder wall, and the prevalence is estimated to be between 0.9% and 12.1%. GPLs include benign polyps and malignant polyps. Benign polyps are further classified as non-neoplastic polyps and neoplastic polyps. Cholesterol polyps are the most common benign polyps and adenocarcinoma is the main type of malignant polyp. Hepatitis B virus infection, liver function abnormalities, dyslipidemia, and obesity are the main risk factors for GPLs. Studies of biological mechanisms have focused on malignant gallbladder polyps, the development of which is regulated by hormone levels in vivo , gut microbiota, inflammation, oxidative stress, Salmonella typhimurium , and related molecules. Diagnostic modalities include chemical examination and imaging examination, with imaging examination currently being the mainstay. Treatment of patients with GPLs is based on the presence or absence of symptoms, age, size of the polyps, tendency of the polyp to increase, and risk factors for symptomatic malignancy to determine whether surgery should be performed.

Preliminary study on diagnosis of gallbladder neoplastic polyps based on contrast-enhanced ultrasound and grey scale ultrasound radiomics

Objective

Neoplastic gallbladder polyps (GPs), including adenomas and adenocarcinomas, are considered absolute indications for surgery; however, the distinction of neoplastic from non-neoplastic GPs on imaging is often challenging. This study thereby aimed to develop a CEUS radiomics nomogram, and evaluate the role of a combined grey-scale ultrasound and CEUS model for the prediction and diagnosis of neoplastic GPs.

Methods

Patients with GPs of ≥ 1 cm who underwent CEUS between January 2017 and May 2022 were retrospectively enrolled. Grey-scale ultrasound and arterial phase CEUS images of the largest section of the GPs were used for radiomics feature extraction. Features with good reproducibility in terms of intraclass correlation coefficient were selected. Grey-scale ultrasound and CEUS Rad-score models were first constructed using the Mann-Whitney U and LASSO regression test, and were subsequently included in the multivariable logistic regression analysis as independent factors for construction of the combined model.

Results

A total of 229 patients were included in our study. Among them, 118 cholesterol polyps, 68 adenomas, 33 adenocarcinomas, 6 adenomyomatoses, and 4 inflammatory polyps were recorded. A total of 851 features were extracted from each patient. Following screening, 21 and 15 features were retained in the grey-scale and CEUS models, respectively. The combined model demonstrated AUCs of 0.88 (95% CI: 0.83 - 0.93) and 0.84 (95% CI: 0.74 - 0.93) in the training and testing set, respectively. When applied to the whole dataset, the combined model detected 111 of the 128 non-neoplastic GPs, decreasing the resection rate of non-neoplastic GPs to 13.3%.

Conclusion

Our proposed combined model based on grey-scale ultrasound and CEUS radiomics features carries the potential as a non-invasive, radiation-free, and reproducible tool for the prediction and identification of neoplastic GPs. Our model may not only guide the treatment selection for GPs, but may also reduce the surgical burden of such patients.

Recent Advances in Endoscopic Ultrasound for Gallbladder Disease Diagnosis

Gallbladder (GB) disease is classified into two broad categories: GB wall-thickening and protuberant lesions, which include various lesions, such as adenomyomatosis, cholecystitis, GB polyps, and GB carcinoma. This review summarizes recent advances in the differential diagnosis of GB lesions, focusing primarily on endoscopic ultrasound (EUS) and related technologies. Fundamental B-mode EUS and contrast-enhanced harmonic EUS (CH-EUS) have been reported to be useful for the diagnosis of GB diseases because they can evaluate the thickening of the GB wall and protuberant lesions in detail. We also outline the current status of EUS-guided fine-needle aspiration (EUS-FNA) for GB lesions, as there have been scattered reports on EUS-FNA in recent years. Furthermore, artificial intelligence (AI) technologies, ranging from machine learning to deep learning, have become popular in healthcare for disease diagnosis, drug discovery, drug development, and patient risk identification. In this review, we outline the current status of AI in the diagnosis of GB.

Imaging update on gallbladder adenomyomatosis and its mimics

Radiologists across many imaging modalities commonly encounter gallbladder adenomyomatosis. The classic imaging appearances of gallbladder adenomyomatosis are well described and confirm benignity. However, in clinical practice, adenomyomatosis can be challenging to differentiate from other gallbladder pathologies that require cholecystectomy. In this article, we describe the common and uncommon appearances of gallbladder adenomyomatosis on multimodality imaging, helping differentiate adenomyomatosis from non-benign gallbladder abnormalities. Accurately differentiating adenomyomatosis from its mimics provides the surgical team with important clinical and surgical management information, improving patient outcomes.

Risk stratification of gallbladder masses by machine learning-based ultrasound radiomics models: a prospective and multi-institutional study

OBJECTIVE

This study aimed to evaluate the diagnostic performance of machine learning (ML)-based ultrasound (US) radiomics models for risk stratification of gallbladder (GB) masses.

METHODS

We prospectively examined 640 pathologically confirmed GB masses obtained from 640 patients between August 2019 and October 2022 at four institutions. Radiomics features were extracted from grayscale US images and germane features were selected. Subsequently, 11 ML algorithms were separately used with the selected features to construct optimum US radiomics models for risk stratification of the GB masses. Furthermore, we compared the diagnostic performance of these models with the conventional US and contrast-enhanced US (CEUS) models.

RESULTS

The optimal XGBoost-based US radiomics model for discriminating neoplastic from non-neoplastic GB lesions showed higher diagnostic performance in terms of areas under the curves (AUCs) than the conventional US model (0.822-0.853 vs. 0.642-0.706, p < 0.05) and potentially decreased unnecessary cholecystectomy rate in a speculative comparison with performing cholecystectomy for lesions sized over 10 mm (2.7-13.8% vs. 53.6-64.9%, p < 0.05) in the validation and test sets. The AUCs of the XGBoost-based US radiomics model for discriminating carcinomas from benign GB lesions were higher than the conventional US model (0.904-0.979 vs. 0.706-0.766, p < 0.05). The XGBoost-US radiomics model performed better than the CEUS model in discriminating GB carcinomas (AUC: 0.995 vs. 0.902, p = 0.011).

CONCLUSIONS

The proposed ML-based US radiomics models possess the potential capacity for risk stratification of GB masses and may reduce the unnecessary cholecystectomy rate and use of CEUS.

CLINICAL RELEVANCE STATEMENT

The machine learning-based ultrasound radiomics models have potential for risk stratification of gallbladder masses and may potentially reduce unnecessary cholecystectomies.

KEY POINTS

• The XGBoost-based US radiomics models are useful for the risk stratification of GB masses. • The XGBoost-based US radiomics model is superior to the conventional US model for discriminating neoplastic from non-neoplastic GB lesions and may potentially decrease unnecessary cholecystectomy rate for lesions sized over 10 mm in comparison with the current consensus guideline. • The XGBoost-based US radiomics model could overmatch CEUS model in discriminating GB carcinomas from benign GB lesions.

Usefulness of contrast-enhanced ultrasonography for biliary tract disease

Conventional ultrasonography (US) for biliary tract disease shows high time and spatial resolution. In addition, it is simple and minimally invasive, and is selected as a first-choice examination procedure for biliary tract disease. Currently, contrast-enhanced US (CEUS), which facilitates the more accurate assessment of lesion blood flow in comparison with color and power Doppler US, is performed using a second-generation ultrasonic contrast agent. Such agents are stable and provide a timeline for CEUS diagnosis. Gallbladder lesions are classified into three types: gallbladder biliary lesion (GBL), gallbladder polypoid lesion (GPL), and gallbladder wall thickening (GWT). Bile duct lesions can also be classified into three types: bile duct biliary lesion (BBL), bile duct polypoid lesion (BDPL), and bile duct wall thickening (BDWT). CEUS facilitates the differentiation of GBL/BBL from tumorous lesions based on the presence or absence of blood vessels. In the case of GPL, it is important to identify a vascular stalk attached to the lesion. In the case of GWT, the presence or absence of a non-contrast-enhanced area, the Rokitansky-Aschoff sinus, and continuity of a contrast-enhanced gallbladder wall layer are important for differentiation from gallbladder cancer. In the case of BDWT, it is useful to evaluate the contour of the contrast-enhanced medial layer of the bile duct wall for differentiating IgG4-related sclerosing cholangitis from primary sclerosing cholangitis. CEUS for ampullary carcinoma accurately reflects histopathological findings of the lesion. Evaluating blood flow in the lesion, continuity of the gallbladder wall, and contour of the bile duct wall via CEUS provides useful information for the diagnosis of biliary tract disease.

Utility and limitations of intraoperative frozen section diagnosis to determine optimal surgical strategy in suspected gallbladder malignancy

BACKGROUND

Preoperative diagnosis of gallbladder cancer (GBC) remains a challenge. Unwarranted extensive surgery for benign disease and undertreatment for GBC pose challenges. We aimed to analyze the utility, diagnostic accuracy, and limitations of intraoperative frozen section (FS), for primary diagnosis of suspected gallbladder malignancy.

METHODS

Patients with suspected GBC underwent a cystic-plate cholecystectomy and FS for primary diagnosis. The procedure was considered adequate if FS suggested a benign pathology. A radical cholecystectomy was performed if FS favoured GBC, or in patients with high intra-operative suspicion of malignancy. All FS records were compared with final histopathology.

RESULTS

FS guided the surgical strategy in 491 of 575 resections (85.4%). FS had a sensitivity of 88.3%, specificity of 99.6%, a positive predictive value of 99.4% and a negative predictive value of 92.7%. The diagnostic accuracy of FS was 95.1%. With routine use of intraoperative FS, only 10 out of 491 patients (2%) required a revised surgical strategy.

CONCLUSIONS

For radiologically suspected GBC it is prudent to confirm the histological diagnosis by use of intraoperative FS before undertaking radical resections. This study emphasizes the safety and accuracy of FS as an adjunct for directing optimal surgical strategy in suspected GBC.

Spectrum of imaging findings in hyperplastic cholecystosis and potential mimics

Adenomyomatosis and cholesterolosis of the gallbladder, collectively termed hyperplastic cholecystosis, are commonly encountered incidental findings on imaging studies performed for a variety of indications including biliary colic or nonspecific abdominal pain. These pathologies are rarely the source of symptoms, generally considered benign and do not require further work-up. However, their imaging characteristics can overlap with more sinister conditions that should not be missed. In this review, the imaging findings of adenomyomatosis and cholesterolosis will be reviewed followed by other gallbladder pathologies that might mimic these conditions radiologically. Important differentiating factors will be discussed that can aid the radiologist in making a more confident imaging diagnosis.

Value of contrast-enhanced ultrasound in diagnosis and differential diagnosis of polypoid lesions of gallbladder ≥ 1 cm

OBJECTIVES

To evaluate the usefulness of Contrast-enhanced ultrasound (CEUS) in the diagnosis and differential diagnosis of Polypoid lesions of gallbladder (PLGs) ≥ 1 cm.

METHODS

A prospective analysis was performed on 180 patients with PLGs ≥ 1 cm. 175 cases were confirmed by pathological diagnosis and the remaining were confirmed by other imaging findings. The characteristics of lesions on conventional Ultrasonography (US) and CEUS were recorded.

RESULTS

Significant differences were observed in enhancement patterns between benign and malignant PLGs during both arterial (P < 0.001) and venous phases (P < 0.001). The malignant lesions typically yielded a "fast-in and fast-out" enhancement pattern. There was no significant difference in Arrival time (AT) between malignant and benign PLGs. If we consider wash-out time ≤ 40 s as a diagnostic standard for malignant lesions, the sensitivity, specificity, and accuracy were 88.24%, 85.62%, and 86.11%, respectively. Destruction of the Gallbladder (GB) wall was a particularly important indication of malignant PLGs, and the sensitivity, specificity, and accuracy were 93.33%, 92.12%, and 92.22%, respectively. The accuracy of CEUS in the diagnosis of PLGs, as well as malignant and benign lesions, was 92.22%, 92.47%, and 91.17%, respectively.

CONCLUSIONS

The "fast-in and fast-out" enhancement pattern, hyper-enhancement in comparison to the GB wall in the arterial phase, wash-out time ≤ 40 s, GB wall destruction, and hepatic parenchymal infiltration are the characteristic findings of malignant PLGs. Besides, CEUS provides a valuable reference to classify some of the benign lesions.

Early Sonographic Detection of Gallbladder Carcinoma Can Improve Patient Outcomes: A Case Report

Gallbladder carcinoma (GBC) is a lethal and rare disease despite it being the most common malignancy of the biliary tract. Most cases of GBC are also associated with cholelithiasis and inflammation. The poor prognosis of GBC is mainly due to a lack of symptoms in the early stages of the disease. Early detection and cholecystectomy can lead to a higher survival rate when the cancer is confined to the gallbladder mucosa. This case study describes a man in his late 50s who presented with elevated liver function tests and was diagnosed incidentally with GBC with sonography.

Conventional Ultrasound Combined With Contrast-Enhanced Ultrasound in Differential Diagnosis of Gallbladder Cholesterol and Adenomatous Polyps (1-2 cm)

OBJECTIVES

This study aimed to determine ultrasonic image characteristics that enable differentiation between cholesterol and adenomatous polyps and to assess the diagnostic efficacy of combining conventional ultrasound (CUS) with contrast-enhanced ultrasound (CEUS).

METHODS

Eighty-nine patients with gallbladder polyps of 1-2 cm in diameter were enrolled and examined by CUS and CEUS before cholecystectomy. The appearances on CUS and CEUS were recorded and analyzed. The receiver operating characteristic (ROC) curve was used to calculate the optimal size threshold for distinguishing cholesterol from adenomatous polyps. A logistic regression analysis was performed to identify diagnostic variables. ROC analysis was performed to evaluate the diagnostic efficacy of the size, the independent variables, and the combined factors.

RESULTS

There were differences in size, number, vascularity on CUS and intralesional vascular shape, wash-out, and area under the curve on CEUS between the two groups (P < .05). ROC analysis indicated that a maximum diameter of 1.45 cm was the optimal threshold for the prediction of adenomatous polyps. The logistic regression analysis proved that the single polyp, presence of vascularity, and intralesional linear vessels were associated with adenomatous polyps (P < .05). ROC analysis showed that the area under the ROC curve, sensitivity, and specificity for the combination of the three independent variables were 0.858, 87.3%, and 67.6%. The number combined with intralesional vascular shape had the highest diagnostic sensitivity of 91.2%.

CONCLUSIONS

The combination of CUS and CEUS demonstrated great significance in the differential diagnosis of cholesterol and adenomatous polyps.

Contrast enhanced ultrasound versus multiphasic contrast enhanced computed tomography in evaluation of gallbladder lesions

AIM

To compare the diagnostic performance of contrast enhanced ultrasound (CEUS) and multiphasic contrast enhanced computed tomography (CECT) in differentiating benign and malignant gallbladder (GB) lesions.

METHODS

This prospective ethical review board approved study comprised consecutive patients with GB lesions who underwent CEUS and multiphasic CECT at a tertiary care referral center. The enhancement patterns at CEUS and CT were compared. The quantitative CEUS parameters including arrival time (AT), AT in liver, time to peak enhancement, and washout time (WT) were assessed. The diagnostic performance of CEUS and CT features was calculated using receiver operating characteristic analysis. A subgroup analysis was performed for patients with GB wall thickening. Multivariate analysis was performed to identify features significantly associated with malignancy.

RESULTS

Over the study period, 30 patients (mean age, 52.8 ± 12.2 years, 17 females) with GB lesions were evaluated. Benign and malignant diseases were present in 13 and 17 patients, respectively. There was excellent agreement between CEUS and CT findings. Among the quantitative CEUS features, only WT was significantly associated with malignancy in the overall group (p < 0.001) and wall thickening subgroup (p = 0.007). WT within 53.5 s and 51.5 s had sensitivity of 88.2% and 81.8% and specificity of 84.5% and 100% in diagnosing malignant lesions in the overall group (AUC 0.900) and the wall thickening subgroup (area under curve, AUC 0.927), respectively. At multivariate analysis, features that were significantly associated with malignant lesions in the overall group were disruption of GB wall (CEUS), intralesional non-enhancing areas (CEUS), liver involvement (CEUS or CT), and arterial phase hyperenhancement (CT) in the overall group and disruption of GB wall (CEUS), WT (CEUS), and liver involvement (CEUS or CT) in the wall thickening subgroup.

CONCLUSION

CEUS is a useful adjunct to CT in evaluation of GB lesions. Its utilization in patients with GB wall thickening may improve detection of malignancy.

A systematic review on application of deep learning in digestive system image processing

With the advent of the big data era, the application of artificial intelligence represented by deep learning in medicine has become a hot topic. In gastroenterology, deep learning has accomplished remarkable accomplishments in endoscopy, imageology, and pathology. Artificial intelligence has been applied to benign gastrointestinal tract lesions, early cancer, tumors, inflammatory bowel diseases, livers, pancreas, and other diseases. Computer-aided diagnosis significantly improve diagnostic accuracy and reduce physicians' workload and provide a shred of evidence for clinical diagnosis and treatment. In the near future, artificial intelligence will have high application value in the field of medicine. This paper mainly summarizes the latest research on artificial intelligence in diagnosing and treating digestive system diseases and discussing artificial intelligence's future in digestive system diseases. We sincerely hope that our work can become a stepping stone for gastroenterologists and computer experts in artificial intelligence research and facilitate the application and development of computer-aided image processing technology in gastroenterology.

Artificial intelligence assists identifying malignant versus benign liver lesions using contrast-enhanced ultrasound

BACKGROUND AND AIM

This study aims to construct a strategy that uses assistance from artificial intelligence (AI) to assist radiologists in the identification of malignant versus benign focal liver lesions (FLLs) using contrast-enhanced ultrasound (CEUS).

METHODS

A training set (patients = 363) and a testing set (patients = 211) were collected from our institute. On four-phase CEUS images in the training set, a composite deep learning architecture was trained and tuned for differentiating malignant and benign FLLs. In the test dataset, AI performance was evaluated by comparison with radiologists with varied levels of experience. Based on the comparison, an AI assistance strategy was constructed, and its usefulness in reducing CEUS interobserver heterogeneity was further tested.

RESULTS

In the test set, to identify malignant versus benign FLLs, AI achieved an area under the curve of 0.934 (95% CI 0.890-0.978) with an accuracy of 91.0%. Comparing with radiologists reviewing videos along with complementary patient information, AI outperformed residents (82.9-84.4%, P = 0.038) and matched the performance of experts (87.2-88.2%, P = 0.438). Due to the higher positive predictive value (PPV) (AI: 95.6% vs residents: 88.6-89.7%, P = 0.056), an AI strategy was defined to improve the malignant diagnosis. With the assistance of AI, radiologists exhibited a sensitivity improvement of 97.0-99.4% (P < 0.05) and an accuracy of 91.0-92.9% (P = 0.008-0.189), which was comparable with that of the experts (P = 0.904).

CONCLUSIONS

The CEUS-based AI strategy improved the performance of residents and reduced CEUS's interobserver heterogeneity in the differentiation of benign and malignant FLLs.

Preoperative Pathological Grading of Hepatocellular Carcinoma Using Ultrasomics of Contrast-Enhanced Ultrasound

RATIONALE AND OBJECTIVES

To develop an ultrasomics model for preoperative pathological grading of hepatocellular carcinoma (HCC) using contrast-enhanced ultrasound (CEUS).

MATERIAL AND METHODS

A total of 235 HCCs were retrospectively enrolled, including 65 high-grade and 170 low-grade HCCs. Representative images of four-phase CEUS were selected from the baseline sonography, arterial, portal venous, and delayed phase images. Tumor ultrasomics features were automatically extracted using Ultrasomics-Platform software. Models were built via the classifier support vector machine, including an ultrasomics model using the ultrasomics features, a clinical model using the clinical factors, and a combined model using them both. Model performances were tested in the independent validation cohort considering efficiency and clinical usefulness.

RESULTS

A total of 1502 features were extracted from each image. After the reproducibility test and dimensionality reduction, 25 ultrasomics features and 3 clinical factors were selected to build the models. In the validation cohort, the combined model showed the best predictive power, with an area under the curve value of 0.785 (95% confidence interval [CI] 0.662-0.909), compared to the ultrasomics model of 0.720 (95% CI 0.576-0.864) and the clinical model of 0.665 (95% CI 0.537-0.793). Decision curve analysis suggested that the combined model was clinically useful, with a corresponding net benefit of 0.760 compared to the other two models.

CONCLUSION

We presented an ultrasomics-clinical model based on multiphase CEUS imaging and clinical factors, which showed potential value for the preoperative discrimination of HCC pathological grades.

Imaging of gallbladder metastasis

Gallbladder metastasis (GM) is a rare condition, often with a late diagnosis or detected upon autopsy. There is no extensive literature on the imaging diagnosis of GM. Here we present a comprehensive review of the literature with the aim of helping to interpret the clinical findings and imaging features of such patients. Few studies on GM are reported in literature. GM by melanoma accounts for about 55.6% of cases. The remaining cases origin from breast cancer (13.6%), hepatocellular carcinoma (13.6%), renal cell carcinoma (6.8%), lung cancer (4.5%), lymphoma (3.5%) and gastric cancer (2.4%). The most common clinical presentation of GM is abdominal pain from cholecystitis due to obstruction of the cystic duct. The main ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) findings that clinicians and radiologists should consider in their everyday medical activity were discussed. The diagnosis of GM was often achieved through a combination of more than one imaging modality. In more than 90% of cases, the diagnosis of GM is often late and combined with other organs involvement in the terminal stage of the malignancy. The knowledge of the clinical features and different imaging techniques through careful evaluation of the gallbladder can help to achieve early diagnosis and avoid misdiagnosis or false negative results.

The Effectiveness of Identifying Primary Gallbladder Adenocarcinoma Utilizing Contrast-Enhanced Ultrasound: A Case Report

Gallbladder carcinoma is rare and difficult to detect in the early stages of the disease process, due to lack of symptoms. Sonography is typically the first modality of choice for assessing gallbladder pathology due to its high sensitivity, portability, real-time imaging capability, and non-ionizing technique. Conventional gray-scale and color Doppler sonographic imaging may be ambiguous for diagnosing solid tumors, such as gallbladder carcinoma. In this case, gallbladder carcinoma was definitively diagnosed utilizing contrast-enhanced ultrasound, allowing for quick patient treatment options and an optimal surgical outcome.

Current update on gallbladder carcinoma

Gallbladder (GB) carcinoma is a relatively rare malignancy and is associated with poor prognosis. Numerous risk factors have been associated with the development of GB carcinoma. GB carcinomas may present as mass lesions replacing the GB, focal or diffuse thickening of the GB wall, and intraluminal mass in the GB. Various benign conditions can mimic GB carcinoma. This article reviews the epidemiology, pathology, clinical findings, imaging features, and management of GB carcinomas.

Is Contrast-Enhanced Ultrasound Superior to Computed Tomography for Differential Diagnosis of Gallbladder Polyps? A Cross-Sectional Study

Objective

To compare the clinical value of contrast-enhanced ultrasonography (CEUS) versus computed tomography (CT) for distinguishing neoplastic and non-neoplastic gallbladder polyps. Given whether laparoscopic cholecystectomy is needed, differential diagnosis of neoplastic and non-neoplastic gallbladder polyps is more important than benign and malignant polyps.

Methods

A total of 89 consecutive patients with polypoid lesions of the gallbladder > 10 mm in size without local invasion or distant metastasis during primary screening were enrolled in this prospective and comparative study. All patients who met the inclusion criteria underwent CEUS and CT examinations prior to surgical resection. The enhancement patterns and microvascular imaging types were analyzed on CEUS. The maximum diameter and CT value of the lesions were also recorded and subjected to a comparative analysis. The clinical value of the two diagnostic methods is compared.

Results

Of the 89 patients, there were 58 (65.2%) cases of non-neoplastic polyps and 31 (34.8%) cases of neoplastic polyps. The average diameter of neoplastic polyps was significantly higher than that of non-neoplastic polyps (P<0.001). The detection rate using CEUS was 100%. The proportion of perceived non-neoplastic polyps in the nonenhanced and arterial phases were 48.3% and 77.6%, respectively, which were significantly lower than those of neoplastic polyps (93.5%, P<0.001 and 100.0%, P<0.001, respectively). However, in the venous and delayed phases, all cholesterol polyps and neoplastic polyps were perceived. CT showed that non-neoplastic polyps exhibited delayed enhancement. On CEUS 29.0% neoplastic polyps showed a perfusion defect, whereas 6.9% non-neoplastic polyps showed a perfusion defect (P=0.005). The microvascular architecture of the lesions on CEUS was categorized into 4 types: spotty, linear, branched, and spinous, and there were significant differences between the two groups (P<0.001). The sensitivities and specificities were 87.10% and 68.97% for CEUS and 83.87% and 77.59% for CT, respectively (P=0.406).

Conclusions

CEUS and CT are useful for differential diagnosis of neoplastic and nonneoplastic polypoid lesions of the gallbladder. Diagnostic efficacy was comparable between CEUS and CT. Thus, CEUS is preferred over CT in the differential diagnosis of neoplastic and non-neoplastic gallbladder polyps due to its comparable diagnostic efficacy and lack of radiation dose.

How Can We Manage Gallbladder Lesions by Transabdominal Ultrasound?

The most important role of ultrasound (US) in the management of gallbladder (GB) lesions is to detect lesions earlier and differentiate them from GB carcinoma (GBC). To avoid overlooking lesions, postural changes and high-frequency transducers with magnified images should be employed. GB lesions are divided into polypoid lesions (GPLs) and wall thickening (GWT). For GPLs, classification into pedunculated and sessile types should be done first. This classification is useful not only for the differential diagnosis but also for the depth diagnosis, as pedunculated carcinomas are confined to the mucosa. Both rapid GB wall blood flow (GWBF) and the irregularity of color signal patterns on Doppler imaging, and heterogeneous enhancement in the venous phase on contrast-enhanced ultrasound (CEUS) suggest GBC. Since GWT occurs in various conditions, subdividing into diffuse and focal forms is important. Unlike diffuse GWT, focal GWT is specific for GB and has a higher incidence of GBC. The discontinuity and irregularity of the innermost hyperechoic layer and irregular or disrupted GB wall layer structure suggest GBC. Rapid GWBF is also useful for the diagnosis of wall-thickened type GBC and pancreaticobiliary maljunction. Detailed B-mode evaluation using high-frequency transducers, combined with Doppler imaging and CEUS, enables a more accurate diagnosis.

Is contrast enhanced ultrasonography an accurate way to diagnose gallbladder adenoma? A systematic review and meta-analysis

INTRODUCTION

Gallbladder adenoma (GA) is a precancerous neoplasm and needs surgical resection. It is difficult to differentiate adenoma from other gallbladder polyps using imaging examinations. The aim of present systematic review and meta-analysis was to evaluate the diagnostic accuracy of contrast-enhanced ultrasound in the diagnosis of gallbladder adenoma.

METHODS

The searches were conducted by two independent researchers to find the relevant studies published from 1/1/2009 until end of 30/06/2019. The search included published literature in the English language in MEDLINE via PubMed, EMBASE via Ovid, The Cochrane Library, and Trip databases. For literature published in other languages, national databases (Magiran and SID), KoreaMed, and LILACS were searched. The risk of bias of every article was evaluated by using QUADAS-2. On the basis of the results from the 2 × 2 tables, pooled measures for sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curves (AUC) along with their 95% confidence intervals (CIs) were calculated using the DerSimonian Lair methodology.

RESULTS

Overall, 868 patients were studied in the 10 studies chosen for inclusion. Of these 10 studies, 5 (50%) were retrospective and 5 (50%) were prospective. The total prevalence of gallbladder adenoma in 10 studies was 16% (95% CI 13%, 18%). The sensitivity and specificity of contrast-enhanced ultrasound were 0.846 (95% CI 0.818-0.871) and 0.870 (95% CI: 0.844-0.894), respectively. The diagnostic odds ratio was 40.807 (95% CI 18.838-88.393).

CONCLUSION

CEUS is a reliable, non-invasive, and no-radiation-exposure imaging modality with a high sensitivity and specificity for detection of gallbladder adenoma. Nonetheless, it should be applied cautiously, and large scale, well-designed trials are necessary to assess its clinical value.

Gallbladder cancer revisited: the evolving role of a radiologist

Gallbladder cancer is the most common malignancy of the biliary tract. It is also the most aggressive biliary tumor with the shortest median survival duration. Complete surgical resection, the only potentially curative treatment, can be accomplished only in those patients who are diagnosed at an early stage of the disease. Majority (90%) of the patients present at an advanced stage and the management involves a multidisciplinary approach. The role of imaging in gallbladder cancer cannot be overemphasized. Imaging is crucial not only in detecting, staging, and planning management but also in guiding radiological interventions. This article discusses the role of a radiologist in the diagnosis and management of gallbladder cancer.

Applications of Computational Methods in Biomedical Breast Cancer Imaging Diagnostics: A Review

With the exponential increase in new cases coupled with an increased mortality rate, cancer has ranked as the second most prevalent cause of death in the world. Early detection is paramount for suitable diagnosis and effective treatment of different kinds of cancers, but this is limited to the accuracy and sensitivity of available diagnostic imaging methods. Breast cancer is the most widely diagnosed cancer among women across the globe with a high percentage of total cancer deaths requiring an intensive, accurate, and sensitive imaging approach. Indeed, it is treatable when detected at an early stage. Hence, the use of state of the art computational approaches has been proposed as a potential alternative approach for the design and development of novel diagnostic imaging methods for breast cancer. Thus, this review provides a concise overview of past and present conventional diagnostics approaches in breast cancer detection. Further, we gave an account of several computational models (machine learning, deep learning, and robotics), which have been developed and can serve as alternative techniques for breast cancer diagnostics imaging. This review will be helpful to academia, medical practitioners, and others for further study in this area to improve the biomedical breast cancer imaging diagnosis.

Meta-analysis of contrast-enhanced ultrasound and contrast-enhanced harmonic endoscopic ultrasound for the diagnosis of gallbladder malignancy

Background

The diagnosis between benign and malignant gallbladder lesions is sometimes difficult. The objective of this study is to assess whether contrast-enhanced ultrasound (CEUS) and contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) can be an accurate method for detecting gallbladder malignancy and to determine which imaging signs can be indicative of malignancy.

Methods

A study search of PubMed, Elsevier, and Sciencedirect was performed in May 2019. The pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve were used to examine the accuracy of CEUS and CH-EUS.

Results

Twenty-one studies were included in the meta-analysis. The pooled sensitivities of CEUS and CH-EUS were 0.81 (0.75–0.86) and 0.92 (0.86–0.95); the specificities were 0.94 (0.90–0.96) and 0.89 (0.69–0. 97); the DORs were 64 (32–127) and 89 (22–354); and the area under the SROC curves were 0.90 (0.87–0.92) and 0.92 (0.90–0.94). On CEUS, the diagnostic criterion for gallbladder malignancy according to four features were analyzed. Sensitivity and specificity were 0.75 (0.65–0.83) and 0.98 (0.85–1.00) for integrity of gallbladder wall; 0.69 (0.55–0.81) and 0.89 (0.77–0.95) for heterogeneous enhancement; 0.81 (0.71–0.88) and 0.88 (0.76–0.94) for irregular vessels; and 0.81 (0.66–0.91) and 0.75 (0.59–0.86) for washout time within 28 s. On CH-EUS, heterogeneous enhancement could be indicative of malignant lesions with a sensitivity of 0.94 (0.85–0.97); and the specificity was 0.92 (0.71–0.98).

Conclusions

CEUS and CH-EUS are promising and reliable imaging modalities with a high sensitivity and specificity for the diagnosis of gallbladder malignancy. CH-EUS might be more sensitive than CEUS with a higher sensitivity. In addition, irregular tralesional vessels and washout time within 28 s on CEUS and heterogeneous enhancement on CH-EUS are indicative of malignancy. However, larger scale and well-designed studies are warranted to verify our results.

Incidentally detected focal fundal gallbladder wall thickening: Differentiation contrast enhanced ultrasound features with high-resolution linear transducers

AIM

To investigate the value of contrast enhanced ultrasound with high resolution linear transducers (HF-CEUS) for differential diagnosis of focal fundal gallbladder (GB) wall thickening.

METHODS

A total of 32 patients with incidentally detected focal fundal GB wall thickening were included. After conventional B mode ultrasound (BMUS) examinations, HF-CEUS were performed with a 7.5-12 MHz 9L4 linear transducer (S2000 HELX OXANA unit, Siemens). Two radiologists independently reviewed the HF-CEUS enhancement patterns to determine the differential features between malignancy and benignity with a five-point confidence scale. The diagnostic accuracy of BMUS and HF-CEUS for GB wall thickening was compared. The final gold standard was surgery with histological examination.

RESULTS

Final diagnoses included GB adenocarcinoma (n = 16), adenomyomatosis (n = 12), Xanthogranulomatous (n = 2) and cholecystitis (n = 2). HF-CEUS features associated with GB adenocarcinoma including arterial phase inhomogeneous hyperenhancement, venous phase hypoenhancement and disruption of GB wall layer structure (P < 0.05). Two small (5 mm) liver metastasis were confirmed by HF-CEUS during the late phase liver sweep as hypoenhanced lesions. Nonenhanced Rokitansky-Aschoff sinuses were clearly observed in 83.3% focal adenomyomatosis. Overall sensitivity, specificity and accuracy for differentiation between malignant and benign focal fundal GB wall thickening of HF-CEUS and BMUS were 84.3% vs 53.1%, 90.6% vs 59.3% and 87.5% vs 56.2% (P < 0.005).

CONCLUSIONS

CEUS performed with high frequency linear transducers could be a useful alternative in the differential diagnosis of focal fundal GB wall thickening on conventional ultrasound.

Differential diagnosis of focal gallbladder lesions: The added value of contrast enhanced ultrasound with liner transducers

BACKGROUND AND AIM

To evaluate the benefits of contrast-enhanced ultrasound (CEUS) with high frequency transducers in characterization of focal gallbladder lesions (FGL).

MATERIAL AND METHODS

From January 2017 to April 2019, 59 FGL detected by B mode ultrasound (BMUS) were examined, first with the low frequency convex transducer (1-5 MHz) and afterwards with high frequency transducer (7.5-12 MHz). High frequency dynamic CEUS were applied after bolus injection of 4.8 ml Sulphur hexafluoride microbubbles (SonoVue®, Milan). The BMUS and CEUS imaging features were recorded and compared. All lesions were confirmed by surgical resection and histopathologic results.

RESULTS

The final diagnoses of 59 FGL included gallbladder adenocarcinoma (n = 15), gallbladder polyps (n = 11), gallbladder adenomas (n = 18), focal adenomyomatosis (n = 9), and gallbladder Ascariasis debris (n = 6). The mean diameter of FGL was 24.5±11.4 mm, and mean depth to the abdominal wall was 21.2±7.3 mm. While applying CEUS with high frequency transducer, specific diagnostic features, including arterial phase irregular intralesional vascularity (10/15, 66.7%), late phase hypoenhancement (12/15, 80%), destruction of gallbladder wall (8/15, 53.3%), infiltration to the adjacent liver (6/15, 40.0%) were significantly higher in malignant FGL. The overall sensitivity, specificity and diagnostic accuracy for the correct characterization of malignant FGL were significantly improved by CEUS with high frequency transducer (sensitivity 93.3%, specificity 88.5%, accuracy 100%).

CONCLUSION

With its superior contrast resolution, CEUS performed with high frequency transducers is helpful to achieve better visualization of gallbladder fundus and make differential diagnosis of gallbladder lesions, which might greatly improve diagnostic confidence between malignant and benign FGL.

Benign gallbladder diseases: Imaging techniques and tips for differentiating with malignant gallbladder diseases

Benign gallbladder diseases usually present with intraluminal lesions and localized or diffuse wall thickening. Intraluminal lesions of the gallbladder include gallstones, cholesterol polyps, adenomas, or sludge and polypoid type of gallbladder cancer must subsequently be excluded. Polyp size, stalk width, and enhancement intensity on contrast-enhanced ultrasound and degree of diffusion restriction may help differentiate cholesterol polyps and adenomas from gallbladder cancer. Localized gallbladder wall thickening is largely due to segmental or focal gallbladder adenomyomatosis, although infiltrative cancer may present similarly. Identification of Rokitansky-Aschoff sinuses is pivotal in diagnosing adenomyomatosis. The layered pattern, degree of enhancement, and integrity of the wall are imaging clues that help discriminate innocuous thickening from gallbladder cancer. High-resolution ultrasound is especially useful for analyzing the layering of gallbladder wall. A diffusely thickened wall is frequently seen in inflammatory processes of the gallbladder. Nevertheless, it is important to check for coexistent cancer in instances of acute cholecystitis. Ultrasound used alone is limited in evaluating complicated cholecystitis and often requires complementary computed tomography. In chronic cholecystitis, preservation of a two-layered wall and weak wall enhancement are diagnostic clues for excluding malignancy. Magnetic resonance imaging in conjunction with diffusion-weighted imaging helps to differentiate xathogranulomatous cholecystitis from gallbladder cancer by identifying the presence of fat and degree of diffusion restriction. Such distinctions require a familiarity with typical imaging features of various gallbladder diseases and an understanding of the roles that assorted imaging modalities play in gallbladder evaluations.

Gallbladder Cancer: Imaging Appearance and Pitfalls in Diagnosis [Formula: see text]

Gallbladder cancer is an uncommon malignancy with an overall poor prognosis. The clinical and imaging presentation of gallbladder cancer often overlaps with benign disease, making diagnosis difficult. Gallbladder cancer is most easily diagnosed on imaging when it presents as a mass replacing the gallbladder. At this stage, the prognosis is usually poor. Recognizing the features of gallbladder cancer early in the disease can enable complete resection and improve prognosis. Recognition of the patterns of wall enhancement on computed tomography can help differentiate gallbladder cancer from benign disease. Gallbladder wall thickening without pericholecystic fluid presenting in an older patient with raised alkaline phosphatase should raise concern regarding gallbladder cancer. Gallbladder polyps in high-risk individuals need close surveillance or surgery as per guidelines. Small gallbladder cancers in the neck can present as biliary dilatation or cholecystitis, and careful examination of this area is needed to assess for lesion. The imaging appearance of gallbladder cancer is reviewed and supported by local institutional data. Features that differentiate it from its common mimics enabling earlier diagnosis are described.

B-mode ultrasonographic diagnosis in gallbladder wall thickening

Diseases associated with gallbladder wall thickening include benign entities such as adenomyomatosis of the gallbladder, acute and chronic cholecystitis, and hyperplasia associated with pancreaticobiliary maljunction, and also cancer. Unique conditions such as sclerosing cholecystitis and cholecystitis associated with immune checkpoint inhibitor treatment can also manifest as wall thickening, as in some systemic inflammatory conditions. Gallbladder cancer, the most serious disease that can show wall thickening, can be difficult to diagnose early and to distinguish from benign causes of wall thickening, contributing to a poor prognosis. Differentiating between xanthogranulomatous cholecystitis and gallbladder cancer with wall thickening can be particularly problematic. Cancers that thicken the wall while coexisting with benign lesions that cause wall thickening represent another potential pitfall. In contrast, some benign gallbladder lesions that can cause wall thickening, such as adenomyomatosis and acute cholecystitis, typically show characteristic ultrasonographic features that, together with clinical findings, permit easier diagnosis. In this review of the literature, we describe B-mode abdominal ultrasonographic diagnosis of gallbladder lesions showing wall thickening.

Performance of contrast-enhanced ultrasound (CEUS) compared to MRI in the diagnostic of gallbladder diseases

BACKGROUND

Conventional ultrasound and MRI are very important techniques for the detection of gallbladder alterations. In the past years, studies showed that the additional use of contrast media to the conventional ultrasound allows the early depiction of pathological microvessels and their flow elucidating suspect findings stipulating the prompt therapy approach.

OBJECTIVE

The study aims to evaluate the performance of CEUS in gallbladder diseases and compare it to MR imaging using histopathological findings as a gold standard.

MATERIAL AND METHODS

The retrospective mono-center study analysed 18 patients with gallbladder alterations between 2009 and 2017. All patients underwent CEUS and MRI examinations and all results were confirmed in the pathology. CEUS images were performed and interpreted by a single experienced physician.

RESULTS

CEUS imaging results compared to MR imaging of the gallbladder demonstrated a sensitivity of 100%, specificity of 93%, a positive predictive value of 67% and a negative predictive value of 100%.

CONCLUSION

CEUS enables the depiction and characterization of important vascularization's patterns facilitating the early differentiation between malignant and benign findings. In this study, CEUS displayed a better diagnostic accuracy than MRI proving to be a valuable additional tool to the established imaging modalities.

Utility of Contrast-Enhanced Ultrasound in Differentiation between Benign Mural Lesions and Adenocarcinoma of Gallbladder

Background

Mural lesions of gallbladder on ultrasound (US) are often difficult to characterize as benign or malignant.

Purpose

The aim of the study was to evaluate the role of contrast-enhanced US (CEUS) in characterization of gallbladder (GB) wall lesions and making distinction between benign wall thickening and GB adenocarcinoma, utilizing both quantitative and qualitative parameters.

Methods

A total of 26 patients with GB wall lesions detected on sonography underwent CEUS. Lesions were evaluated on the basis of morphological imaging features, enhancement pattern, dynamic real-time contrast uptake, and intralesional vascularity.

Results

Overall, 19 patients had final diagnosis of GB adenocarcinoma, whereas seven patients had benign etiology. CEUS has enabled the differentiation of nonenhancing tumefactive sludge from enhancing mural lesions, thus improving the accuracy of morphological assessment of lesions. The intactness of outer wall was better assessed on CEUS. The dynamic postcontrast assessment showed that carcinoma showed early washout of contrast compared to benign thickening (P = 0.002). Nonlayered mural enhancement or thick enhancing inner layer with nonenhancing thin outer layer was associated with adenocarcinoma. The classification of intralesional vascularity on CEUS was not helpful in distinguishing benign lesions and adenocarcinoma.

Conclusion

CEUS can increase the diagnostic confidence in differentiation between benign mural lesions and adenocarcinoma of GB.

Feasibility study for rapid near-infrared spectroscopic identification of different gallbladder diseases by direct analysis of bile juice

A whole-sample-covering near-infrared (NIR) spectroscopy scheme has been adopted for the simple drop-and-dry measurement of raw bile juice for the identification of gallbladder (GB) diseases of stone, polyp, and cancer. For reproducible measurement, a non-NIR absorbing polytetrafluoroethylene (PTFE) providing a hydrophobic surface was chosen as a substrate to form bile juice droplets of a consistent shape. To ensure representative spectroscopic sampling, NIR radiation illuminated the whole area of the dried sample for spectral acquisition. The NIR band shapes and relative band intensities of GB cancer differed moderately from those of GB stone and GB polyp. The composition of GB cancer samples was presumed to be dissimilar from other sample compositions. Differentiation between GB polyp and GB stone, however, was less facile; nevertheless, in the case of GB polyp samples, the obtained NIR features were informative in the identification of various pathological conditions such as adenomyomatosis (abnormal growth of epidermal tissue) and hepatitis B. To elucidate the NIR features of bile juice samples, separate NIR spectra of major bile constituents such as conjugated bile salts, lecithin, cholesterol, and albumin were analyzed. The demonstrated NIR spectroscopy scheme requiring no sample pretreatment or separation of bile juice could be useful for fast bile juice-based screening of GB diseases, especially the identification of early GB cancer.

Contrast-enhanced Ultrasound in evaluating of angiogenesis and tumor staging of nasopharyngeal carcinoma in nude mice

OBJECTIVE

To explore the use of Contrast-enhanced Ultrasound (CEUS) in evaluating angiogenesis in a xenograft nasopharyngeal carcinoma (NPC) model in nude mice and the evolution of CEUS parameters according to the growth of NPC.

METHODS

Nude mice were divided into three groups according to experiments conducted at various times from tumor implantation (8 mice/group; group A: 4 weeks from implantation; group B:6 weeks from implantation; group C:8 weeks from implantation). CNE-2 cells were transplanted in 24 nude mice and CEUS evaluations of the tumors were performed at 4, 6 or 8 weeks from implantation. CEUS parametric perfusion images and pathological findings were recorded. R version 3.4.4 software was used to analyze the CEUS parameters and pathological findings.

RESULTS

One-way anova analysis indicated statistically significant differences among the three groups with the parameters of peak intensity (PI) (p<0.001), area wash in (AWI) (p<0.001), area wash out (AWO) (p<0.001) and tumor volumes (p<0.001).Pearson correlation coefficient analysis indicated that microvessel density (MVD) was correlated with tumor volume (r = 0.644, p = 0.001), PI (r = 0.904, p<0.0001), AWI (r = 0.547, p = 0.008) and AWO (r = 0.744, P<0.0001). Tumor volume was correlated with MVD (r = 0.644, p = 0.001), PI (r = 0.625, p = 0.002), AWI (r = 0.528, p = 0.012) and AWO (r = 0.784, p<0.001). The percentage of necrosis in histological sections was correlated with the percentage of CEUS unperfused area (r = 0.446,p = 0.038). Spearman rank correlation coefficient analysis indicated that vascular endothelial growth factor (VEGF) was correlated with PI (r = 0.462, P = 0.032). Welch t test indicated PI, AWI and AWO parameters were significantly lower than that of kidneys (p<0.001, p = 0.009, p = 0.005).

CONCLUSIONS

The CEUS parameters PI, AWI and AWO indirectly reflect the MVD and the tumor volume in our model of subcutaneous transplanted NPC in nude mice, providing precious information on angiogenesis and tumor growth. VEGF may play a role in promoting angiogenesis of NPC.

Improved infrared spectroscopic discrimination between gall bladder (GB) polyps and GB cancer using component-descriptive spectral features of separated phases from bile

This study demonstrates a unique strategy for enhancing infrared (IR) spectroscopic discrimination between gall bladder (GB) polyps and cancer. This strategy includes the separation of raw bile juice into three sections of organic, aqueous, and amphiphilic phases and a cooperative combination of all IR spectral features of each separated phase for the discrimination. Raw bile juice is viscous and complex in composition because it contains fatty acids, cholesterol, proteins, phospholipids, bilirubin, and other components; therefore, the acquisition of IR spectra providing more component-discernible information is fundamental for improving discrimination. For this purpose, raw bile juice was separated into an aqueous phase, mostly containing bile salts, an organic phase with isolated lipids, and an amphiphilic phase, mainly containing proteins. The subsequent IR spectra of each separated phase were mutually characteristic and complementary to each other. When all the IR spectral features were combined, the discrimination was improved compared to that using the spectra of raw bile juice with no separation. The cooperative integration of more component-specific spectra obtained from each separated phase enhanced the discrimination. In addition, the IR spectra of the major constituents in bile juice, such as bile acids, conjugated bile salts, lecithin, and cholesterol, were recorded to explain the IR features of each separated phase.

Contrast-enhanced ultrasound (CEUS) and gallbladder diseases - A retrospective mono-center analysis of imaging findings with histopathological correlation

BACKGROUND

Radiologic imaging, especially ultrasound has an important role in the assessment of gallbladder alteration. Contrast-enhanced ultrasound (CEUS) is an easy and fast imaging technique that overcomes the limitations of greyscale ultrasonography. It is a safe tool that can be used as an additional imaging modality in order to elucidate and differentiate gallbladder pathological findings.

OBJECTIVE

The aim of this retrospective study analysis is to assess the diagnostic performance of CEUS in gallbladder alterations and compare the results to the histopathological findings.

METHODS

A total of 17 patients between 2009 and 2017 with uncertain gallbladder appearance were retrospectively analysed. A single experienced physician with more than fifteen years' experience performed CEUS examinations by applying a second-generation blood pool agent (SonoVue®, Bracco, Milan, Italy). Archived images were interpreted by the same physician and compared to the histopathological findings.

RESULTS

CEUS results, when correlated to the respectively pathologic findings, presented a sensitivity of 100%, a specificity of 100%, a positive predictive value (PPV) of 100% and a negative predictive value (NPV) of 100%. All patients were successfully examined without any adverse reaction.

CONCLUSION

In conclusion, the excellent results in this study acknowledged that CEUS is a feasible alternative tool to differentiate gallbladder pathologic alterations.

Quantitative contrast-enhanced US helps differentiating neoplastic vs non-neoplastic gallbladder polyps

OBJECTIVES

To differentiate between large (≥ 1 cm in diameter) gallbladder (GB) non-neoplastic and neoplastic polyps using quantitative analysis of contrast-enhanced ultrasound (CEUS) findings.

METHODS

From September 2017 to May 2018, 29 patients (10 males; median age, 63 years) with GB polyps of ≥ 1 cm in diameter who were undergoing cholecystectomy were consecutively enrolled. All patients underwent preoperative conventional US and CEUS examinations. Quantitative analysis of CEUS findings using time-intensity curves between the two groups was independently performed by two radiologists. The interobserver agreement for the quantitative analysis of the CEUS results was measured using the intraclass correlation coefficient. Receiver operating characteristic analysis was performed to evaluate the diagnostic performance of CEUS examination.

RESULTS

After the cholecystectomy, the patients were classified into the non-neoplastic polyp group (n = 12) and the neoplastic polyp group (n = 17) according to the pathological results. The interobserver agreement for quantitative assessment between the two radiologists was near perfect to substantial. Quantitative assessment of the CEUS findings revealed that the rise time, mean transit time, time to peak, and fall time of non-neoplastic GB polyps were significantly shorter than those of neoplastic polyps (p < 0.001, p = 0.008, p = 0.013, and p = 0.002, respectively). The sensitivity and specificity of the quantitative CEUS parameters for the differentiation between the two groups were 76.5-100% and 75%, respectively, with an area under the curve of 0.765-0.887.

CONCLUSIONS

Quantitative analysis of CEUS findings could be valuable in differentiating GB neoplastic polyps from non-neoplastic polyps.

KEY POINTS

• Quantitative analysis of CEUS findings could be valuable in differentiating gallbladder neoplastic polyps from non-neoplastic polyps. • Quantitative analysis of CEUS findings in gallbladder polyps provides cut-off values for differentiation between neoplastic polyps and non-neoplastic polyps with near-perfect to substantial interobserver agreement.

Differential diagnosis of gallbladder polypoid lesions using contrast-enhanced ultrasound

PURPOSE

The purpose of the study is to evaluate the utility of contrast-enhanced ultrasound (CEUS) for the differential diagnosis of gallbladder polypoid lesions (GPLs).

METHODS

Thirty-six patients with GPLs (17 with gallbladder cancer, 19 with benign polyps) who underwent CEUS were enrolled in the study. The mean age of patients was 65.7 ± 12.6 years. Perflubutane-based contrast agent and high-mechanical index mode, which can eliminate the background B-mode and provide precise visualization of tumor vessels, were used for CEUS, and two blinded readers evaluated the images, retrospectively.

RESULTS

Patient age and size of malignant GPLs (72.4 ± 9.4 years and 23.4 ± 7.5 mm) were significantly greater than those for benign lesions (59.6 ± 12.3 years and 12.4 ± 2.9 mm) (P < 0.01, respectively), and the receiver operating characteristic analysis showed the cut-off value as over 65 years and 16 mm. Univariate analysis showed that heterogeneity in B-mode (80% [12/15]), sessile shape (76% [13/17]), dilated vessel (71% [12/17]), irregular vessel (82% [14/17]), and heterogeneous enhancement (59% [10/17]) on CEUS were significantly correlated with malignant GPLs (P < 0.01, respectively). On CEUS, the diagnostic criterion for malignant GPLs was defined as having one or more of the above four features because of the highest accuracy. Sensitivity, specificity, and accuracy for malignant GBLs were 88%, 68%, and 78% for patient age; 76%, 89%, and 83% for size of GPLs; 80%, 68%, and 74% for B-mode; and 94%, 89%, and 92% for CEUS, respectively.

CONCLUSIONS

CEUS is useful for the differential diagnosis of malignant and benign GPLs.

Incidental metastases and lymphoma of the gallbladder - an analysis of ten rare cases identified from a large national database

Background: The aim was to identify and characterize rare malignancies of the gallbladder, incidentally found at cholecystectomy, and describe the diagnostic work-up, treatment and outcome. Methods: Data from cholecystectomies during 2007-2014 registered in the Swedish Register for Gallstone Surgery (GallRiks) were analyzed for incidental cancer. For completion of the pathology report, data were linked with the Swedish Registry for Cancer in the liver and biliary tract (SweLiv) and/or the Swedish Cancer Registry. Results: From 36,355 patients that underwent cholecystectomy on a benign indication 215 cases of incidental gallbladder cancer (IGBC) were identified. In total seven patients with metastases to the gallbladder from different primary tumors (breast cancer, malignant melanoma, gastric cancer, renal cell carcinoma, upper gastrointestinal cancer, colon cancer and pancreatic cancer) and three patients with lymphoma involvement of the gallbladder were found. Most patients were female with no difference between the groups (8/10 versus 171/215). The median age for the metastasis and lymphoma (MOL) group was equal to the IGBC group, 70 (64-72) years versus 70 (63-78) years. All patients in the MOL group underwent preoperative imaging with ultrasound or computed tomography, on which no metastases were identified. In only two patients a tumor was seen by the surgeon during the perioperative examination of the gallbladder. The median survival was 5.8 months for MOL patients and 23 months for IGBC patients. Conclusion: Metastases and lymphoma of the gallbladder are rare. Traditional imaging methods prior to cholecystectomy may miss gallbladder malignancies. A liberal approach of histopathological analysis of the gallbladder should be applied.

Cross-sectional Imaging of Gallbladder Carcinoma: An Update

Gallbladder Carcinoma (GBCA) is the most common biliary tract malignancy. As the disease is often diagnosed clinically in an advanced stage, the survival rates are dismal. Imaging studies allow for an early diagnosis of malignancy, though the findings may be indistinguishable from non-malignant disease processes affecting the gallbladder. Attempts have been made to make a specific diagnosis of GBCA at an early stage on imaging studies. Ultrasonography (US) is the most commonly employed technique for gallbladder evaluation. Gallbladder wall thickening is the most common finding of early GBCA and in this context, US is non-specific. Recently, contrast enhanced ultrasound has been shown to be effective in differentiating benign from malignant disease. Multidetector computed tomography represents the most robust imaging technique in evaluation of GBCA. It provides relatively sensitive evaluation of mural thickening, though it is not entirely specific and issues in differentiating GBCA from xanthogranulomatous cholecystitis do arise. Due to its superior soft tissue resolution, Magnetic Resonance Imaging (MRI) provides excellent delineation of gallbladder and biliary tree involvement. When coupled with functional MRI techniques, such as diffusion-weighted and perfusion imaging, it provides a useful problem solving tool for interrogating the malignant potential of nonspecific gallbladder lesions and detection of metastases. Positron emission tomography has a role in detection of distant metastases and following patients following treatment for malignancy. We review the current role of various imaging modalities in evaluating patients with GBCA.

A Case of Tubular Adenoma of Gallbladder Diagnosed Using Contrast-Enhanced Ultrasonography

Contrast-enhanced ultrasound (CEUS) has been used to diagnose gallbladder (GB) diseases for recent years because it is sensitive to visualize vascularity. Herein, we report a case who had a 1.7 cm × 1.2 cm polypoid lesion located in the gallbladder fundus with a feeding artery located in the stalk. On CEUS, the lesion showed early arterial phase enhancement (time to peak enhancement 18 s), persisting throughout the venous and delay phases. This enhancing pattern suggested that the lesion was a GB adenoma rather than a GB carcinoma. Cholecystectomy was performed, and pathology of the tissue revealed tubular adenoma of the GB.

Potential role of contrast-enhanced ultrasound for the differentiation of malignant and benign gallbladder lesions in East Asia: A meta-analysis and systematic review

BACKGROUND

The purpose of this study was to systematically review and evaluate the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in differentiating malignant and benign gallbladder lesions.

METHODS

We conducted a comprehensive search on PubMed, Embase, and Cochrane Library for all potential relevant articles published before December 2017. The pooled sensitivity, specificity, diagnostic odds ratio (DOR) and area under the curve (AUC) of summary receiver operating characteristic (SROC) were calculated by Meta-Disc Version 1.4 and STATA 12.0.

RESULTS

Twelve eligible studies were included in our study. A total of 1044 patients were assessed. The pooled sensitivity and specificity were 0.81 (95% confidence interval [CI], 0.77-0.84; inconsistency index [I] = 84.5%) and 0.87 (95% CI, 0.85-0.89; I = 94.4%), respectively. The pooled DOR was 58.84 (95% CI, 32.39-106.88; I = 51.9%). The AUC was 0.9371. According to Deek funnel plot asymmetry test, there was no significant publication bias (P = .31).

CONCLUSIONS

The results yielded from the available evidence suggest that CEUS is a promising and adjuvant imaging technique to conventional ultrasound for the differential diagnosis of benign and malignant gallbladder lesions.

Contrast-enhanced ultrasonography improves the diagnostic specificity for gallbladder-confined focal tumors

PURPOSE

To investigate the value of contrast-enhanced ultrasonography (CEUS) in the differential diagnosis of malignant and benign focal gallbladder diseases confined to the gallbladder wall.

METHODS

From July 2006 to May 2016, 88 patients (mean age 48.8 years; age range 18-77 years) were enrolled. All patients had focal gallbladder lesions confined to the gallbladder wall according to CEUS examination. The conventional ultrasound and CEUS characteristics of the lesions were evaluated, and diagnostic performance was evaluated via receiver-operating characteristic (ROC) analysis.

RESULTS

Multiple logistic regression analysis showed that three characteristics, an irregular shape, branched intralesional vessels and hypo-enhancement in the late phase, were features indicating a malignant gallbladder disease (all P < 0.05). When combining any two of these three features, diagnostic specificity improved from 51.5%-77.3% to 92.4% (P < 0.05 for all), and the area under the ROC (AUROC) curve improved from 0.735-0.874 to 0.917, without a significant loss of sensitivity.

CONCLUSIONS

CEUS features have greater specificity than those from conventional US for the differentiation of benign and malignant gallbladder diseases confined to the gallbladder wall, without a loss of sensitivity.

Contrast-enhanced ultrasound findings of gallbladder adenocarcinoma with sarcomatoid carcinoma accompanied by intrahepatic metastasis: A case report and literature review

RATIONALE

Gallbladder adenocarcinoma is the most common subtype of malignant tumor in gallbladder carcinoma; its incidence is quite low. Preoperative diagnosis of gallbladder adenocarcinoma appears to be very difficult because they are normally asymptomatic and are often found incidentally. Adenocarcinoma with sarcomatoid carcinoma of gallbladder is exceedingly rare with no case reported in the literature to date.

PATIENT CONCERNS

A 69-year-old male was referred to our hospital due to right upper quadrant pain. To further diagnosis, he received laboratory tests, gray-scale US, and contrast-enhanced ultrasound (CEUS). In this present study, ethical approval was not necessary, as this article is a case report, which is based on the clinical information of the patient. The patient gave his permission for publication of the case.

DIAGNOSES

Gray-scale abdominal ultrasound image demonstrated a hypoechoic intraluminal mass of gallbladder and a heterogeneous mass at the inferior segment of the right anterior liver lobe. In CEUS, the lesion of gallbladder was hyper-enhanced in the arterial phase, and hypo-enhanced in the later arterial phase. On liver, the hepatic lesion appeared heterogenous mild enhancement in the arterial phase. In portal and parenchymal phase, the hepatic lesion displayed hypo-enhancement, which conformed to the hepatic metastasis.

INTERVENTIONS

The patient received cholecystectomy, right hepatectomy, and lymphadenectomy.

OUTCOMES

He had an uneventful recovery from the procedure.

LESSONS

We presented a case report with gallbladder adenocarcinoma with sarcomatoid carcinoma accompanied by intrahepatic metastasis, focusing on the ultrasound imaging features of this tumor, especially its enhancement pattern on CEUS. CEUS provided helpful information for diagnosis. Herein, we report the case; and the associated literature is further reviewed.

CEUS in the differential diagnosis between biliary sludge, benign lesions and malignant lesions

PURPOSE

Conventional grayscale ultrasound (US) is accurate in the diagnosis of gallbladder disease (GD), but in some cases, it is not decisive. Contrast-enhanced ultrasound (CEUS) improves the diagnostic accuracy of US. The primary objective of this study is to assess the reliability of CEUS in the diagnosis of sludge; the secondary objective is to assess the ability of CEUS to diagnose cancer.

METHODS

We retrospectively reviewed the US of 4137 patients positive for GD. In 43/4137 (1.04%), the use of could not discriminate between sludge and neoplasms. Then, we evaluated CEUS in only 39 of these patients, and in 4/43 (9%) cases it was not performable. After CEUS, the absence of enhancement was considered diagnostic for sludge, while contrast washout within 60 s diagnosed malignant lesions.

RESULTS

Among the 39 patients, 16 had biliary sludge and 23 had lesions of the gallbladder wall; 9 of these were carcinomas and 14 were benign tumors. The absence of enhancement was present in 16/16 patients with sludge and in 0/23 patients with lesions of the gallbladder (sensitivity and specificity 100%). Washout was within 60 s in 9/9 gallbladder carcinomas and 2/14 benign lesions (sensitivity 100%; specificity 85%).

CONCLUSIONS

US is confirmed to be accurate in the diagnosis of GD. In doubtful cases, CEUS is very accurate in biliary sludge diagnosis. An intralesional washout at 60 s is a pattern of malignancy that can orient towards a correct diagnosis, but it is limited by the presence of false positive results, especially for smaller lesions.