Cross-sectional Imaging of Gallbladder Carcinoma: An Update

The Many Hidden Faces of Gallbladder Carcinoma on CT and MRI Imaging-From A to Z

Gallbladder carcinoma represents the most aggressive biliary tract cancer and the sixth most common gastrointestinal malignancy. The diagnosis is a challenging clinical task due to its clinical presentation, which is often non-specific, mimicking a heterogeneous group of diseases, as well as benign processes such as complicated cholecystitis, xanthogranulomatous cholecystitis, adenomyomatosis, porcelain gallbladder or metastasis to the gallbladder (most frequently derived from melanoma, renal cell carcinoma). Risk factors include gallstones, carcinogen exposure, porcelain gallbladder, typhoid carrier state, gallbladder polyps and abnormal pancreaticobiliary ductal junction. Typical imaging features on CT or MRI reveal three major patterns: asymmetric focal or diffuse wall-thickening of the gallbladder, a solid mass that replaces the gallbladder and invades the adjacent organs or as an intraluminal enhancement mass arising predominantly from the gallbladder fundus. The tumor can spread to the liver, the adjacent internal organs and lymph nodes. Depending on the disease stage, surgical resection is the curative treatment option in early stages and adjuvant combination chemotherapy at advanced stages. The purpose of this scientific paper is to fully illustrate and evaluate, through multimodality imaging findings (CT and MRI), different presentations and imaging scenarios of gallbladder cancer in six patients and thoroughly analyze the risk factors, patterns of spread and differential diagnosis regarding each particular case.

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.

Incidental Findings of Gallbladder and Bile Ducts-Management Strategies: General Aspects, Gallbladder Polyps and Gallbladder Wall Thickening-A World Federation of Ultrasound in Medicine and Biology (WFUMB) Position Paper

The World Federation of Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings with a series of position papers to give advice on characterization and management. The biliary system (gallbladder and biliary tree) is the third most frequent site for incidental findings. This first part of the position paper on incidental findings of the biliary system is related to general aspects, gallbladder polyps and other incidental findings of the gallbladder wall. Available evidence on prevalence, diagnostic work-up, malignancy risk, follow-up and treatment is summarized with a special focus on ultrasound techniques. Multiparametric ultrasound features of gallbladder polyps and other incidentally detected gallbladder wall pathologies are described, and their inclusion in assessment of malignancy risk and decision- making on further management is suggested.

Computed diffusion-weighted magnetic resonance imaging with high b-values in the diagnosis of gallbladder lesions

PURPOSE

The diagnosis of gallbladder lesions remains challenging. The efficacy of computed diffusion-weighted imaging (DWI) with high b-values and apparent diffusion coefficient (ADC) for the diagnosis of gallbladder cancer remains unknown. We aimed to investigate the usefulness of computed DWI with high b-values and the combination of computed DWI and ADC in differentiating malignant and benign gallbladder lesions.

METHODS

Sixty patients (comprising 30 malignant and 30 benign lesions) who underwent magnetic resonance imaging for gallbladder lesions were included in this retrospective study. Qualitative evaluations were performed using conventional DWI with b1000, computed DWI with b1500, b1000 DWI/ADC, and computed b1500 DWI/ADC, and their diagnostic performances were compared.

RESULTS

The sensitivity, specificity, and accuracy of computed b1500 DWI/ADC were 90% (27/30), 80% (24/30), and 85% (51/60), respectively. The accuracy of computed b1500 DWI/ADC was higher than that of conventional b1000 DWI (52%, 31/60, p < 0.001), computed b1500 DWI (72%, 43/60, p = 0.008), and b1000 DWI/ADC (78%, 47/60, p = 0.125). The specificity of computed b1500 DWI/ADC was also higher than that of conventional b1000 DWI (7%, 2/30, p < 0.001), computed b1500 DWI (47%, 14/30, p = 0.002), and b1000 DWI/ADC (67%, 20/30, p = 0.125). No significant difference was observed in the sensitivity between the groups.

CONCLUSION

This study shows that computed DWI with high b-values combined with ADC can improve diagnostic performance when differentiating malignant and benign gallbladder lesions. Computed diffusion-weighted magnetic resonance imaging with high b-values in the diagnosis of gallbladder lesions. *Computed DWI with b1500 combined with ADC can improve diagnostic performance when differentiating gallbladder lesions compared with conventional methods (b1000 DWI).

The Diagnostic Accuracy of 18F-FGD-PET/CT for Cancer of the Gallbladder: A Retrospective Study

Background  Gallbladder cancer has a poor prognosis and imaging can have variable diagnostic accuracy. We assessed the ability of preoperative ¹⁸ F-fluorodeoxyglucose positron emission tomography computed tomography ( ¹⁸ F-FDG-PET/CT) imaging to predict a postoperative histological diagnosis of gallbladder cancer.

Method  A retrospective analysis was undertaken in a cohort of patients, who had suspected gallbladder cancer on cross-sectional imaging and that underwent preoperative FDG-PET/CT scan. The discriminatory power of FDG-PET/CT was determined in receiver operator characteristic (ROC) analysis and diagnostic accuracy parameters were estimated at different thresholds of maximum standard unit value (SUV _max ) _.

Results  Twenty-two patients were included in the study; 7 had malignant and 15 benign diagnoses. There was no statistically significant difference between the measured SUV _max between the two groups ( p  = 0.71). With an area under the curve of 0.486, the ROC curve did not indicate any discriminatory power of FDG-PET/CT at any potential threshold of SUV _max.

Conclusion  This study indicates that the diagnosis of primary gallbladder cancer cannot be accurately confirmed with FDG PET/CT scanning.

Segnet Network Algorithm-Based Ultrasound Images in the Diagnosis of Gallbladder Stones Complicated with Gallbladder Carcinoma and the Relationship between P16 Expression with Gallbladder Carcinoma

The study focused on how to improve the diagnostic coincidence rate of patients with gallbladder stones and gallbladder cancer based on an optimized Segnet network algorithm and the relationship of gallbladder cancer with multiple tumor suppressor 1 (P16). 300 patients diagnosed with gallbladder cancer in the hospital were selected as the research subjects. The pyramid pooling operation was incorporated into the original Segnet network algorithm, and its performance was evaluated, factoring into the intersection of union (IoU), algorithm precision (Pre), and recall rate (Recall). After 8 hours of fasting, conventional ultrasound and contrast-enhanced ultrasound examinations were performed, and the images were evaluated by three experienced ultrasound diagnosticians. The positive signal of P16 immunohistochemical staining was brownish yellow, which was generally concentrated in the nucleus, and a small part was located in the cytoplasm. In each slice, ten visual fields were selected. Then, they were observed under a high-power mirror, and the number was counted. It was found that the optimized Segnet network algorithm increased the IoU by 7.3%, the precision by 8.2%, and the recall rate by 11.1%. The diagnostic coincidence rates of conventional ultrasound and contrast-enhanced ultrasound examinations for gallbladder cancer were 78.13% (25/32) and 87.5% (25/32), respectively. The positive expression rate of P16 in gallbladder adenocarcinoma (47.06%) was significantly lower than that of acute cholecystitis with gallbladder stones (84.38%) and gallbladder polyps (67.16%) (P < 0.05). The positive expression rate of P16 in patients with stage III and stage IV (33.33% and 40%) was significantly lower than that in patients with stages I and II (87.5% and 80%) (P < 0.05). The positive expression rate of P16 in high differentiation (86.67%) was significantly higher than that of moderate differentiation (40%) and poor differentiation (28.57%) (P < 0.05). In short, contrast-enhanced ultrasound can effectively improve the diagnostic coincidence rate of gallbladder cancer, and the expression of P16 in gallbladder cancer is closely related to tumor staging and differentiation.

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.

NIR/photoacoustic imaging of multitype gallbladder cancer using carboxyl/amino functionalized polymer dots

Gallbladder cancer has high incidence and mortality and a low early diagnosis rate and requires rapid and efficient diagnosis. Herein, carboxyl/amino functionalized polymer dots (Pdots) were designed to enhance cellular internalization and tumor accumulation. The prepared Pdots were 40-50 nm in diameter, contained no toxic metal, exhibited long circulation time and high stability, and produced strong NIR emission and photoacoustic signals. Different cellular uptake and distribution of functionalized Pdots in eight gallbladder cell lines were quantitatively investigated using flow cytometry and super-resolution microscopy. In vivo NIR fluorescence imaging showed that the functional Pdots had high accumulation in the tumor after 30 minutes of injection and remained there for up to 6 days. In addition, photoacoustic imaging found that the abundant blood vessels around the tumor microenvironment and Pdots entered the tumor through the blood vessels. Furthermore, a high heterogeneity of vascular networks was visualized in real-time and high resolution by probe-based confocal laser endomicroscopy imaging. These results offer a new avenue for the development of functional Pdots as a probe for multi-modal and multi-scale imaging of gallbladder cancer in small animals.

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.

Evaluation of gallbladder wall thickening: a multimodality imaging approach

INTRODUCTION

Gallbladder (GB) wall thickening is a relatively common finding on imaging. While there are clear recommendations for the management of gallstones, GB wall thickening presents a significant challenge. Despite advances in radiological as well as endoscopic techniques, the ability to characterize GB wall thickening is still limited.

AREAS COVERED

This review summarizes the currently available literature on various imaging investigations to characterize GB wall thickening. This review also summarizes the differences between benign and malignant GB wall thickening based on available imaging modalities. Transabdominal ultrasonography is the first-line investigation for evaluation of GB wall thickening. However, further characterization requires additional imaging tests. Magnetic resonance imaging (MRI) with the use of gadolinium and diffusion-weighted sequence is the preferred modality for GB wall characterization.

EXPERT OPINION

The accurate characterization of GB wall thickening is a challenging task. The available imaging criteria allow differentiation of benign and malignant GB wall thickening with moderate accuracy. The advanced imaging techniques, including contrast enhanced ultrasound, contrast-enhanced endoscopic ultrasound, and shear wave elastography, continue to evolve. There is a need for a well-designed reporting system for GB wall thickening to ensure uniformity of reporting of imaging tests, especially in regions with a high prevalence of GB cancer.

Prevalence and Sonographic Detection of Gallbladder Polyps in a Western European Population

BACKGROUND

Gallbladder cancer is rare but associated with significant morbidity and mortality necessitating the early identification of premalignant and malignant lesions to improve overall prognosis. Despite limited evidence regarding the effectiveness of transabdominal ultrasound (US) in the detection of gallbladder polyps, it plays a key role in current European guidelines. The aim of this study was to investigate gallbladder polyp prevalence in a western European population and assess the diagnostic accuracy of transabdominal US.

METHODS

Data from patients who underwent cholecystectomy for US detected gallbladder polypoid lesions at four hospitals in Ireland and the United Kingdom between 2010 and 2018 were retrospectively collected. Patient demographics, ultrasonographic, and histopathologic findings were analyzed.

RESULTS

A total of 134 patients underwent cholecystectomy for US-detected gallbladder polyps. After histopathologic examination, pseudopolyps were found in 75 (56%) specimens with dysplastic or malignant polyps seen in only six (4.5%) specimens. Mean size for neoplastic polyps was 33 mm. The positive predictive value for US in detecting neoplastic polyps in this study was 4.5%, which is significantly lower than the 10%-15% reported previously.

CONCLUSIONS

Although the prevalence of neoplastic polyps in this study is higher than in the previous literature, the distribution of pseudopolyps and true polyps is as expected. With all malignant polyps being >10 mm in diameter, these findings support the current size thresholds stated in European guidelines. The poor diagnostic accuracy of US demonstrated may have led to significant number of patients undergoing unnecessary surgical intervention, further supporting the argument for improved strategies for the investigation of gallbladder polyps.