Gallbladder wall thickening: MR imaging and pathologic correlation with emphasis on layered pattern

Surgical and Oncological Outcomes of Wedge Resection Versus Segment 4b + 5 Resection for T2 and T3 Gallbladder Cancer: a Meta-Analysis

BACKGROUND

Liver resection is the standard operative procedure for patients with T2 and T3 gallbladder cancers (GBC). However, the optimal extent of hepatectomy remains unclear.

METHODS

We conducted a systematic literature search and meta-analysis to assess the safety and long-term outcomes of wedge resection (WR) vs. segment 4b + 5 resection (SR) in patients with T2 and T3 GBC. We reviewed surgical outcomes (i.e., postoperative complications and bile leak) and oncological outcomes (i.e., liver metastasis, disease-free survival (DFS), and overall survival (OS)).

RESULTS

The initial search yielded 1178 records. Seven studies reported assessments of the above-mentioned outcomes in 1795 patients. WR had significantly fewer postoperative complications than SR, with an odds ratio of 0.40 (95% confidence interval, 0.26 - 0.60; p < 0.001), although there were no significant differences in bile leak between WR and SR. There were no significant differences in oncological outcomes such as liver metastases, 5-year DFS, and OS.

CONCLUSIONS

For patients with both T2 and T3 GBC, WR was superior to SR in terms of surgical outcome and comparable to SR in terms of oncological outcomes. WR that achieves margin-negative resection may be a suitable procedure for patients with both T2 and T3 GBC.

Sequential histologic evolution of gallbladder inflammation in acute cholecystitis over the first 10 days after onset of symptoms

BACKGROUND

The timing of cholecystectomy during acute cholecystitis (AC) is controversial, especially whether it is advisable to perform in patients with duration of symptoms between 3 and 10 days. The purpose of this study is to define clearly the sequential evolution of histological changes following symptoms onset to guide recommendations regarding timing of cholecystectomy.

METHODS

We identified patients with AC (2005-2018) who had cholecystectomy within 10 days of symptom onset of a first attack of AC. Histologic features of gallbladder injury including cellular and exudative inflammatory response to injury were determined on blinded pathologic slides.

RESULTS

One hundred and forty-nine patients were divided into three groups; early-who underwent cholecystectomy 1-3 days after symptom-onset, intermediate-4-6 days, and late-7-10 days. Key features of injury were necrosis and hemorrhage. A subgroup of patients in the early phase developed severe necrosis and hemorrhage of an extent associated with difficult cholecystectomy. Large spikes in extent of necrosis and hemorrhage occurred at 7-10 days. Major inflammatory responses to injury were eosinophilic and lymphocytic infiltration and early fibrosis.

CONCLUSIONS

Severe necrosis may develop rapidly and be present in the early period after symptom onset of AC. Cholecystectomy may be reasonable in some patients but by day 7-10, severe necrosis and hemorrhage may be expected to be present in most patients.

Multiparametric MR imaging with diffusion-weighted, intravoxel incoherent motion, diffusion tensor, and dynamic contrast-enhanced perfusion sequences to assess gallbladder wall thickening: a prospective study based on surgical histopathology

OBJECTIVE

To investigate the diagnostic performance of a multiparametric magnetic resonance imaging (MRI) protocol comprising quantitative MRI (diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), diffusion tensor imaging (DTI), and dynamic contrast-enhanced (DCE) perfusion MRI) and conventional MRI in the characterization of gallbladder wall thickening (GWT).

METHODS

This prospective study comprised consecutive adults with GWT who underwent multiparametric MRI between July 2020 and April 2022. Two radiologists evaluated the MRI independently. The final diagnosis was based on surgical histopathology. The association of MRI parameters with malignant GWT was evaluated. The area under the curve (AUC) for the quantitative MRI parameters and diagnostic performance of conventional, and multiparametric MRI were compared. The interobserver agreement between two radiologists was calculated.

RESULTS

Thirty-five patients (mean age, 56 years, 23 females) with GWT (25 benign and ten malignant) were evaluated. The quantitative MRI parameters significantly associated with malignant GWT were apparent diffusion coefficient on DWI (p = 0.007) and mean diffusivity (MD) on DTI (p = 0.013), perfusion fraction (f) on IVIM (p = 0.033), time to peak enhancement (TTP, p = 0.008), and wash in rate (p = 0.049) on DCE-MRI. TTP had the highest AUC of 0.790, followed by MD (0.782) and f (0.742) (p = 0.213) for predicting malignant GWT. Multiparametric MRI had significantly higher sensitivity (90% vs. 80%, p = 0.045) than conventional MRI for diagnosing malignant GWT. The two radiologists' reading had substantial to near-perfect agreement (kappa = 0.639-1) and moderate to strong correlation (interclass correlation coefficient = 0.5-0.88).

CONCLUSION

Multiparametric protocol incorporating advanced sequences improved the diagnostic performance of MRI for differentiating benign and malignant GWT.

KEY POINTS

• Multiparametric MRI had 90% sensitivity and 88% specificity for diagnosing malignant GWT, compared to 80% sensitivity and 88% specificity for conventional CE-MRI. • Among the quantitative MRI parameters, TTP (perfusion-MRI) had the highest AUC of 0.790, followed by MD (0.782) and IVIM-f (0.742). • For most quantitative MRI parameters, there was moderate to strong agreement (ICC = 0.5-0.88).

The gallbladder: what's new in 2022?

This review focuses mainly on the imaging diagnosis, treatment, and complications of acute cholecystitis which is the most common benign disease of the gallbladder. The American College of Radiology appropriateness criteria for the imaging evaluation of patients with right upper quadrant pain and the Tokyo Guidelines for evaluating patients with acute cholecystitis and acute cholangitis are presented. The recent articles for using US, CT, MR, and HIDA in the evaluation of patients with suspected acute cholecystitis are reviewed in detail. The clinical management and postoperative complications are described. Because gallbladder polyps and adenomyomatosis can mimic gallbladder malignancies and acute cholecystitis, their imaging findings and management are presented. Finally, due the recent literature reporting better results with CT than US in the diagnosis of acute cholecystitis, a suggested approach for imaging patients with right upper quadrant pain and possible acute cholecystitis is presented in an addendum.

Differentiating benign from malignant gallbladder wall thickening in non-contrast MRI imaging: Preliminary study of a combined diagnostic indicator

To synthetically evaluate the diagnostic accuracy of image features for differentiating benign from malignant gallbladder wall thickening disease with non-contrast MRI and establish the optimal diagnostic indicator. A total of 23 patients with wall thickening type gallbladder carcinoma and 61 patients with benign wall thickening disease were included. The diagnostic performance of six image features including the layered pattern on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) images, T2WI signal intensity, papillary growth, the apparent diffusion coefficient (ADC) value, and the lesion to liver parenchyma ratio (LLR) of gallbladder were evaluated and compared. The receiver operating characteristic (ROC) curve and binary logistic regression analysis were used to construct the optimally combined indicator. All six indicators showed high diagnostic accuracy. The layered pattern on DWI and LLR had the highest area under the curve (AUC) value (0.904), followed by the layered pattern on T2WI (0.883), T2WI signal intensity (0.859), ADC value (0.836), and papillary growth (0.796). There was no statistically significant difference in the AUC among indicators for pairwise comparisons. A combination of layered patterns on DWI and papillary growth was shown to be the optimal indicator by binary logistic regression analysis. The AUC value of the combination (0.972) was higher than the layered pattern on DWI (0.904) and papillary growth (0.796) (P < .001). Non-contrast MRI provides several reliable indicators for differentiating benign from malignant gallbladder thickening disease. The combination of layered patterns on DWI and papillary growth is the optimal indicator.

Gallbladder Metastasis of Renal Cell Carcinoma: A Case Report

The gallbladder (GB) is a rare site of renal cell carcinoma (RCC) metastasis. To the best of our knowledge, only a few reports of CT findings of GB metastasis exist in the literature. Herein, we report a case of histologically proven GB metastasis of RCC in a 55-year-old male who underwent CT for an intraluminal polypoid mass simulating a primary GB lesion.

The value of diffusion-weighted imaging in diagnosing gallbladder malignancy: performance of a new parameter

AIM

To assess the value of the ratio of signal intensities at high and low b-values (b800/b0 ratio) during diffusion-weighted imaging (DWI) for gallbladder cancer diagnosis.

MATERIALS AND METHODS

All patients presenting with suspicious gallbladder lesions between January 2011 and December 2016 who underwent DWI and histopathological diagnoses of the lesions were assessed.

RESULTS

Thirty-two patients (24 men, eight women) were identified. Eighteen patients had benign gallbladder lesions while 14 had malignant lesions. The mean apparent diffusion coefficient (ADC) value was 1.62 (±0.57)×10^-3 mm²/s for benign cases and 1.27 (±0.39)×10^-3 mm²/s for malignant cases; this difference was not significant (p=0.0773). The mean b800/b0 ratio was 0.31 (±0.19) for benign cases and 0.48 (±0.13) for malignant cases; this difference was significant (p=0.007). The ROC curve for b800/b0 had an AUC of 0.782 (95% confidence interval [CI]: 0.616-0.947) with a sensitivity and specificity of 85.7% and 72.2%, respectively, at a cut-off point of 0.33.

CONCLUSION

The b800/b0 ratio can help differentiate benign and malignant gallbladder lesions and may be more reliable than ADC values in quantitative DWI assessments.

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.

Preoperative Magnetic Resonance Cholangiopancreatography for Detecting Difficult Laparoscopic Cholecystectomy in Acute Cholecystitis

Previous studies have shown that signal intensity variations in the gallbladder wall on magnetic resonance imaging (MRI) are associated with necrosis and fibrosis in the gallbladder of acute cholecystitis (AC). However, the association between MRI findings and operative outcomes remains unclear. We retrospectively identified 321 patients who underwent preoperative magnetic resonance cholangiopancreatography (MRCP) and early laparoscopic cholecystectomy (LC) for AC. Based on the gallbladder wall signal intensity on MRI, these patients were divided into high signal intensity (HSI), intermediate signal intensity (ISI), and low signal intensity (LSI) groups. Comparisons of bailout procedure rates (open conversion and laparoscopic subtotal cholecystectomy) and operating times were performed. The recorded bailout procedure rates were 6.8% (7/103 cases), 26.7% (31/116 cases), and 40.2% (41/102 cases), and the median operating times were 95, 110, and 138 minutes in the HSI, ISI, and LSI groups, respectively (both p < 0.001). During the multivariate analysis, the LSI of the gallbladder wall was an independent predictor of both the bailout procedure (odds ratio [OR] 5.30; 95% CI 2.11–13.30; p < 0.001) and prolonged surgery (≥144 min) (OR 6.10, 95% CI 2.74–13.60, p < 0.001). Preoperative MRCP/MRI assessment could be a novel method for predicting surgical difficulty during LC for AC.

Imaging-based algorithmic approach to gallbladder wall thickening

Gallbladder (GB) wall thickening is a frequent finding caused by a spectrum of conditions. It is observed in many extracholecystic as well as intrinsic GB conditions. GB wall thickening can either be diffuse or focal. Diffuse wall thickening is a secondary occurrence in both extrinsic and intrinsic pathologies of GB, whereas, focal wall thickening is mostly associated with intrinsic GB pathologies. In the absence of specific clinical features, accurate etiological diagnosis can be challenging. The survival rate in GB carcinoma (GBC) can be improved if it is diagnosed at an early stage, especially when the tumor is confined to the wall. The pattern of wall thickening in GBC is often confused with benign diseases, especially chronic cholecystitis, xanthogranulomatous cholecystitis, and adenomyomatosis. Early recognition and differentiation of these conditions can improve the prognosis. In this minireview, the authors describe the patterns of abnormalities on various imaging modalities (conventional as well as advanced) for the diagnosis of GB wall thickening. This paper also illustrates an algorithmic approach for the etiological diagnosis of GB wall thickening and suggests a formatted reporting for GB wall abnormalities.

Preoperative MRI for predicting pathological changes associated with surgical difficulty during laparoscopic cholecystectomy for acute cholecystitis

BACKGROUND

Severe inflammation with necrosis and fibrosis of the gallbladder in acute cholecystitis increases operative difficulty during laparoscopic cholecystectomy. This study aimed to assess the use of preoperative MRI in predicting pathological changes of the gallbladder associated with surgical difficulty.

METHODS

Patients who underwent both preoperative MRI and early cholecystectomy for acute cholecystitis between 2012 and 2018 were identified retrospectively. On the basis of the layered pattern of the gallbladder wall on MRI, patients were classified into three groups: high signal intensity (HSI), intermediate signal intensity (ISI), and low signal intensity (LSI). The endpoint was the presence of pathological changes of the gallbladder associated with surgical difficulty, such as necrosis, abscess formation and fibrosis.

RESULTS

Of 229 eligible patients, pathological changes associated with surgical difficulty were found in 17 (27 per cent) of 62 patients in the HSI group, 84 (85 per cent) of 99 patients in the ISI group, and 66 (97 per cent) of 68 patients in the LSI group (P < 0·001). For detecting these changes, intermediate to low signal intensity of the gallbladder wall had a sensitivity of 90 (95 per cent c.i. 84 to 94) per cent, specificity of 73 (60 to 83) per cent and accuracy of 85 (80 to 90) per cent.

CONCLUSION

Preoperative MRI predicted pathological changes associated with surgical difficulty during laparoscopic cholecystectomy for acute cholecystitis.

Lymph Nodal Metastatic Pattern in Carcinoma Gallbladder with Multidetector Computed Tomography: An Institutional Experience

Objective This work aimed to study the distribution of lymph nodal metastatic pattern in carcinoma gallbladder with multidetector computed tomography (CT).

Materials and Methods A retrospective observational study was conducted including 80 patients with carcinoma gallbladder who underwent triple-phase CT angiography or single-phase contrast-enhanced CT scan of the abdomen between January 2019 and November 2019.

Results In our study, 75 (93.7%) out of 80 cases showed metastasis to lymph nodes, with distribution as follows: periportal (69), peripancreatic (62), and aortocaval (47). The most common involved combination included all three lymph nodal groups (periportal, peripancreatic, and aortocaval), involving 40 (50%) cases. The combination of only periportal and peripancreatic lymph nodes was seen in 17 (21%) cases. Isolated periportal lymph nodes were seen in eight cases (10%) cases. The combination of only periportal and aortocaval lymph nodes was seen in four (5%) cases. Isolated peripancreatic lymph nodes were seen in three (3.7%) cases. The combination of periportal and aortocaval was seen in four (5%) cases followed by peripancreatic and aortocaval lymph nodes that was seen in two (2.5%) cases. Isolated aortocaval lymph nodes were seen in one (1.2%) case.

Conclusion Periportal lymph nodes were the single most commonly involved station followed by peripancreatic and aortocaval lymph nodes. The combination of periportal, peripancreatic, and aortocaval lymph nodes was seen most commonly. The second most commonly involved combination was found to be periportal and peripancreatic lymph nodes followed by isolated periportal lymph nodes.

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.

Recommendations for the Management of Incidental Hepatobiliary Findings in Adults: Endorsement and Adaptation of the 2017 and 2013 ACR Incidental Findings Committee White Papers by the Canadian Association of Radiologists Incidental Findings Working Group

The Canadian Association of Radiologists Incidental Findings Working Group consists of both academic subspecialty and general radiologists and is tasked with adapting and expanding upon the American College of Radiology incidental findings white papers to more closely apply to Canadian practice patterns, particularly more comprehensively dealing with the role of ultrasound and pursuing more cost-effective approaches to the workup of incidental findings without compromising patient care. Presented here are the 2020 Canadian guidelines for the management of hepatobiliary incidental findings. Topics covered include initial assessment of hepatic steatosis and cirrhosis, the workup of incidental liver masses identified on ultrasound and computed tomography (with algorithms presented), incidental gallbladder findings (wall thickening, calcification, and polyps), and management of incidental biliary dilatation.

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.

Chronic inflammation-related radiological findings of gallbladder adenomyomatosis

PURPOSE

This study aimed to assess radiological findings of adenomyomatosis advancing to chronic inflammation to differentiate between adenomyomatosis with and without chronic inflammation.

MATERIALS AND METHODS

We retrospectively identified 79 patients with pathologically proven adenomyomatosis without (n = 10) or with chronic inflammation (n = 69), who underwent computed tomography (CT) and magnetic resonance imaging (MRI) followed by surgery. MRI analysis included evaluation of GB wall-thickening type, presence and location of intramural cysts, and presence of stones. CT analysis included GB wall-thickening type only. Multivariate logistic regression analysis was used to identify the image-based findings of adenomyomatosis associated with chronic inflammation.

RESULTS

On univariate analysis, MRI-based GB wall-thickening type and presence of stones, and CT-based GB wall-thickening type were significantly different between adenomyomatosis with and without chronic inflammation. On multivariate analysis, only the absence of stones was identified as a significant predictor of adenomyomatosis without chronic inflammation (odds ratio 5.58; 95% confidence interval 1.20-26.01; p = 0.029). There was no significant difference in other MRI- and CT-based findings between adenomyomatosis with and without chronic inflammation.

CONCLUSION

In patients with adenomyomatosis, the presence of stones was independently associated with chronic inflammation.

Development and Validation of a Nomogram for Early Detection of Malignant Gallbladder Lesions

OBJECTIVES

Preoperative decision-making for differentiating malignant from benign lesions in the gallbladder remains challenging. We aimed to create a diagnostic nomogram to identify gallbladder cancer (GBC), especially for incidental GBC (IGBC), before surgical resection.

METHODS

A total of 587 consecutive patients with pathologically confirmed gallbladder lesions from a hospital were randomly assigned to a training cohort (70%) and an internal validation cohort (30%), with 287 patients from other centers as an external validation cohort. Radiological features were developed by the least absolute shrinkage and selection operator logistic regression model. Significant radiological features and independent clinical factors, identified by multivariate analyses, were used to construct a nomogram.

RESULTS

A diagnostic nomogram was established by age, CA19.9, and 6 radiological features. The values of area under the curve in the internal and external validation cohorts were up to 0.91 and 0.89, respectively. The calibration curves for probability of GBC showed optimal agreement between nomogram prediction and actual observation. Compared with previous methods, it demonstrated superior sensitivity (91.5%) and accuracy (85.1%) in the diagnosis of GBC. The accuracy using the nomogram was significantly higher in GBC groups compared with that by radiologists in the training cohort (P < 0.001) and similarly in each cohort. Notably, most of the IGBC, which were misdiagnosed as benign lesions, were successfully identified using this nomogram.

DISCUSSION

A novel nomogram provides a powerful tool for detecting the presence of cancer in gallbladder masses, with an increase in accuracy and sensitivity. It demonstrates an unprecedented potential for IGBC identification.

Histopathological Changes in Gallbladder Mucosa Associated with Cholelithiasis: A Prospective Study

Background and Aims

Cholelithiasis is known to produce diverse histopathological changes in the gallbladder mucosa. In the present study, we aimed to find the correlation between various gallstone characteristics (i.e., number, size, and morphological type) with the type of mucosal response in gallbladder mucosa (i.e., inflammation, hyperplasia, metaplasia, and carcinoma).

Methods

The present study was conducted prospectively on 100 patients undergoing cholecystectomy for symptomatic cholecystitis. Gallstones were assessed for various parameters, i.e., number, size, and morphological type. Gallbladder mucosa was subjected to histopathological examination. Sections were taken from body, fundus, and neck of gallbladder.

Results

Of 100 cases, maximum type was of mixed stones (54%) and was multiple in number (46%). However, gallstone type and number are nonsignificant variables to produce precancerous lesions (i.e., hyperplasia and metaplasia). Statistically significant results were obtained while comparing the mucosal response with gallstone size (P = 0.012).

Conclusion

As the gallstone size increases, the response in gallbladder mucosa changes from cholecystitis, hyperplasia, and metaplasia to carcinoma. Gallstone type and number are nonsignificant variables to produce precancerous lesions.

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.

Usefulness of noncontrast MRI in differentiation between gallbladder carcinoma and benign conditions manifesting as focal mild wall thickening

BACKGROUND

Magnetic resonance imaging (MRI) is a reliable imaging tool for evaluating gallbladder carcinoma, but it is costly and time-consuming.

PURPOSE

To compare noncontrast MRI with multidetector row CT (MDCT) and gadoxetic acid-enhanced whole MRI in distinguishing gallbladder carcinoma from benign disease.

MATERIALS AND METHODS

101 patients (36 with gallbladder carcinoma and 65 with benign disease) with mild focal gallbladder wall thickening were included. Two radiologists reviewed the MDCT and MRI to determine the differential features between malignancy and benignity. Then, the diagnostic performance of MDCT and MRI (T1-, T2- and diffusion-weighted images) with and without gadoxetic acid enhancement in the diagnosis of gallbladder carcinoma was evaluated.

RESULTS

The benign group more often showed T2 necklace sign or T2 hyperintensity within the thickened wall (P < 0.0001) and T1 hyperintensity within the wall or gallbladder lumen (P = 0.0002). Meanwhile, malignancy more frequently showed T2 moderate hyperintensity of the thickened wall, papillary appearance, and diffusion restriction (all P < 0.0001). There were significant differences in sensitivity (79.2% vs 98.6% for observer 1; 84.7% vs 100% for observer 2) and specificity (80.7% vs 96.9%; 79.2% vs 95.4%) between the MDCT and noncontrast MRI (P < 0.05). We found similar diagnostic values between the noncontrast MRI and whole MRI (P = 0.479-1.000) for both observers.

CONCLUSION

Noncontrast MRI could be a useful alternative to gadoxetic acid-enhanced MRI in the diagnosis of gallbladder carcinoma that presents as mild gallbladder wall thickening on MDCT.

Differentiation of acute cholecystitis from chronic cholecystitis: Determination of useful multidetector computed tomography findings

The purpose of this study was to determine the diagnostic value of multidetector computed tomography (MDCT) imaging findings, to identify the most predictive findings, and to assess diagnostic performance in the diagnosis and differentiation of acute cholecystitis from chronic cholecystitis.In this retrospective study, we enrolled 382 consecutive patients with pathologically proven acute or chronic cholecystitis who underwent computed tomography (CT) within 1 month before surgery. The CT findings were compared and logistic regression analysis was used to identify significant CT findings in predicting acute cholecystitis. Diagnostic performance of each CT finding and of combined findings was also assessed.Statistically significant CT findings distinguishing acute cholecystitis from chronic cholecystitis were increased gallbladder dimension (85.5% vs 50.6%, P < .001), increased wall enhancement (61.8% vs 78.9%, P = .001), increased wall thickness (67.9% vs 31.1%, P < .001), mural striation (64.9% vs 28.3%, P < .001), pericholecystic haziness or fluid (66.4% vs 21.2%, P < .001), increased adjacent hepatic enhancement (80.0% vs 32.4%, P < .001), focal wall defect (9.2% vs 0, P < .001), and pericholecystic abscess (10.7% vs 0, P < .001). Subsequent multivariate logistic regression analysis revealed that increased adjacent hepatic enhancement [P = .006, odds ratio (OR) = 3.82], increased gallbladder dimension (P = .027, OR = 3.12), increased wall thickening or mural striation (P = .019, OR = 2.89), and pericholecystic haziness or fluid (P = .032, OR = 2.61) were significant predictors of acute cholecystitis. When 2 of these 4 CT findings were observed together, the sensitivity, specificity, and accuracy for the detection of acute cholecystitis were 83.2%, 65.7%, and 71.7%, respectively. When 3 of these 4 CT findings were observed together, the sensitivity, specificity, and accuracy were 56.5%, 84.5%, and 74.9%, respectively. When none of these 4 CT findings were observed, the negative predictive value was 96.4%.Increased adjacent hepatic enhancement, increased gallbladder dimension, increased wall thickening or mural striation, and pericholecystic fat haziness or fluid were the most discriminative MDCT findings for the diagnosis and differentiation of acute cholecystitis from chronic cholecystitis.

Diffusion-weighted whole-body magnetic resonance imaging with background body signal suppression/T2 image fusion for the diagnosis of acute cholecystitis

Prompt and accurate diagnosis is critical in the treatment of acute cholecystitis. Diffusion-weighted whole-body magnetic resonance imaging with background body signal suppression/T2 image fusion (DWIBS/T2) identifies areas with high signal intensity, corresponding to inflammation. In the present study, the records and images of patients with acute cholecystitis who underwent DWIBS/T2 between January 2013 and March 2014 were retrospectively analyzed. A total of 11 patients with acute cholecystitis were enrolled. In one patient, DWIBS/T2 identified a thickened wall and high signal intensity, with high signal intensity in the pericholecystic space that suggested localized peritonitis. Positive DWIBS/T2 results indicating acute cholecystitis were obtained in 10/11 patients, with a sensitivity of 90.9%. In addition, wall thickening and high signal intensity were absent in DWIBS/T2 images when wall thickening was not detected by computed tomography. Wall thickening and high signal intensity was attenuated when patients with acute cholecystitis were clinically treated. These data suggest that a thickened gallbladder wall and high signal intensity are indicative of acute cholecystitis and that DWIBS/T2 may be a useful technique in evaluating the severity of acute cholecystitis.

Imaging Evaluation of Enhancement Patterns of Flat Gall Bladder Wall Thickening and Its Correlation with Clinical and Histopathological Findings

INTRODUCTION

Gall bladder Wall Thickening (GWT) is caused by wide spectrum of diseases. Initially Ultrasound (USG) was used as imaging modality for screening of acute abdomen because of its high sensitivity and real time character. Now, Computed Tomography (CT) is used because of its high temporal and spatial resolution.

AIM

Evaluation of GWT and its enhancement patterns on contrast enhanced CT scan in a bid to differentiate benign from malignant causes and to correlate the imaging features with clinical and histopathological findings.

MATERIALS AND METHODS

It was a hospital based prospective study in which USG was done as an initial modality for screening and Multi Detector Computed Tomography (MDCT) scan was done later on for detailed evaluation of enhancement patterns of GWT. The study cases were then divided into five CT patterns according to enhancement patterns. The diagnostic performance of MDCT was compared with histopathological and serological findings. Relevant history, clinical examination and routine investigations were done.

RESULTS

The one layered pattern with a heterogeneously enhancing thick layered pattern (Type 1) was significantly associated with gall bladder cancer (p<0.001). The sensitivity and specificity of Type 1 enhancement pattern on CT for predicting the Gall Bladder (GB) malignancy were 90.476% and 97.43% respectively. The positive and negative predictive values were 95% and 95%, respectively. Focal wall thickening, irregular margin character and hepatic infiltration by GWT and lymphadenopathy were other findings that predict malignancy (p-value<0.05).

CONCLUSION

MDCT enhancement patterns of a thickened GB wall and associated findings were helpful in differentiating malignant GWT from benign GWT.

Diffusion-weighted magnetic resonance imaging to differentiate malignant from benign gallbladder disorders

PURPOSE

To retrospectively evaluate the utility of apparent diffusion coefficient (ADC) and lesion to spinal cord ratio (LSR) in diffusion-weighted magnetic resonance (MR) imaging (DWI) as compared with morphological assessment alone, for differentiating malignant from benign gallbladder disorders.

METHODS

This study was approved by the ethics committee, and written informed consent was waived. Ninety-one patients (13 malignancy and 78 benignancy) were reviewed. ADC was calculated using two DW images with different motion-probing gradient strengths (b=0, 1000s/mm(2)). LSR was measured by dividing the signal intensity of a thickened gallbladder wall by the maximum signal intensity of the lumbar enlargement of the spinal cord. In addition, the morphology of the gallbladders was assessed with conventional MR imaging.

RESULTS

In receiver operating characteristic curve analysis, the areas under the curves for ADC and LSR were 0.861 and 0.906, respectively. Three morphological findings were considered: a massive formation, a disrupted mucosal line, and the absence of a two-layered pattern. When a combination of two or more of these morphological findings was positive for malignancy, the sensitivity, specificity, and accuracy were 76.9%, 84.0%, and 83.0%, respectively. When a combination of three or more of the above morphological findings together with ADC of less than 1.2 × 10(-3)mm(2)/s or LSR of more than 0.48 were positive for malignancy, these values were 73.0%, 96.2%, and 92.9%, respectively. There were significant differences in specificity and accuracy.

CONCLUSION

Use of ADC and LSR in DWI can improve diagnostic performance for differentiating malignant from benign gallbladder disorders.

A literature review of radiological findings to guide the diagnosis of gallbladder adenomyomatosis

BACKGROUND

Gallbladder adenomyomatosis (GA) is a benign gallbladder entity discovered as an asymptomatic gallbladder mass. Since gallbladder cancer is in the differential diagnosis for gallbladder masses, the ability to differentiate benign disease avoids a more extensive oncologic resection. This study sought to review imaging modalities used to diagnose GA.

METHODS

PubMed and SciVerse Scopus were systematically searched using the terms: "gallbladder adenomyomatosis" and "gallbladder imaging" for articles published between January 2000 and January 2015.

RESULTS

A total of 14 articles were reviewed in this analysis. Contemporary series report the use of ultrasound (US), computed tomography (CT) or magnetic resonance imaging (MRI) in GA imaging. Ultrasound detection of Rokitansky-Aschoff sinuses, visualized as small cystic spaces with associated "comet-tail" or "twinkling" artifact, is pathognomonic for GA. A "Pearl-Necklace" sign of small connected sinuses on MRI or "Rosary" sign on CT are additional characteristics that may assist in establishing a diagnosis.

CONCLUSION

Ultrasound is the most commonly used tool to investigate GA. If not diagnostic, CT or MRI are effective in attempting to differentiate a benign or malignant cholecystic mass. Characteristic signs should lead the surgeon to perform a laparoscopic cholecystectomy in symptomatic patients or manage non-operatively in asymptomatic patients.

Suitability of Patients with Autosomal Dominant Polycystic Kidney Disease for Renal Transcatheter Arterial Embolization

In patients with autosomal dominant polycystic kidney disease (ADPKD), massive renal enlargement is a serious problem. Renal transcatheter arterial embolization (TAE) can reduce renal volume (RV), but effectiveness varies widely, and the reasons remain unclear. We investigated factors affecting renal volume reduction rate (RVRR) after renal TAE in all 449 patients with ADPKD who received renal TAE at Toranomon Hospital from January of 2006 to July of 2013, including 228 men and 221 women (mean age =57.0±9.1 years old). One year after renal TAE, the RVRR ranged from 3.9% to 84.8%, and the least squares mean RVRR calculated using a linear mixed model was 45.5% (95% confidence interval [95% CI], 44.2% to 46.8%). Multivariate analysis using the linear mixed model revealed that RVRR was affected by the presence of large cysts with wall thickening (regression coefficient [RC], -6.10; 95% CI, -9.04 to -3.16; P<0.001), age (RC, -0.82; 95% CI, -1.03 to -0.60; P<0.001), dialysis duration (RC, -0.10; 95% CI, -0.18 to -0.03; P<0.01), systolic BP (RC, 0.39; 95% CI, 0.19 to 0.59; P<0.001), and the number of microcoils used for renal TAE (RC, 1.35; 95% CI, 0.83 to 1.86; P<0.001). Significantly more microcoils were needed to achieve renal TAE in patients with younger age and shorter dialysis duration. In conclusion, cyst wall thickening had an important effect on cyst volume reduction. Renal TAE was more effective in patients who were younger, had shorter dialysis duration, or had hypertension, parameters that might associate with cyst wall stiffness and renal artery blood flow.

CT findings of gallbladder metastases: emphasis on differences according to primary tumors

Objective

To describe computed tomography (CT) features of metastatic gallbladder (GB) tumors (MGTs) from various primary tumors and to determine whether there are differential imaging features of MGTs according to different primary tumors.

Materials and Methods

Twenty-one patients who had pathologically confirmed MGTs and underwent CT were retrospectively enrolled. Clinical findings including presenting symptoms, type of surgery, and interval between primary and metastatic tumors were recorded. Histologic features of primary tumor and MGTs including depth of invasion were also reviewed. Imaging findings were analyzed for the location and morphology of MGTs, pattern and degree of enhancement, depth of invasion, presence of intact overlying mucosa, and concordance between imaging features of primary and metastatic tumors. Significant differences between the histologies of MGTs and imaging features were determined.

Results

The most common primary tumor metastasized to the GB was gastric cancer (n = 8), followed by renal cell carcinoma (n = 4) and hepatocellular carcinoma (n = 3). All MGTs (n = 21) manifested as infiltrative wall thickenings (n = 15) or as polypoid lesions (n = 6) on CT, similar to the features of primary GB cancers. There were significant differences in the morphology of MGTs, enhancement pattern, enhancement degree, and depth of invasion according to the histology of primary tumors (p < 0.05). Metastatic adenocarcinomas of the GB manifested as infiltrative and persistently enhancing wall thickenings, while non-adenocarcinomatous metastases usually manifested as polypoid lesions with early wash-in and wash-out.

Conclusion

Although CT findings of MGTs are similar to those of primary GB cancer, they are significantly different between the various histologies of primary tumors.

MR imaging of the biliary system

Although ultrasound, computed tomography, and cholescintigraphy play essential roles in the evaluation of suspected biliary abnormalities, magnetic resonance (MR) imaging and MR cholangiopancreatography can be used to evaluate inconclusive findings and provide a comprehensive noninvasive assessment of the biliary tract and gallbladder. This article reviews standard MR and MR cholangiopancreatography techniques, clinical applications, and pitfalls. Normal biliary anatomy and variants are discussed, particularly as they pertain to preoperative planning. A spectrum of benign and malignant biliary processes is reviewed, emphasizing MR findings that aid in characterization.

Diffusion-weighted MRI for differentiation of benign from malignant lesions in the gallbladder

AIM

To investigate the value of diffusion-weighted imaging (DWI) for differentiating benign from malignant gallbladder lesions.

MATERIALS AND METHODS

One hundred and twenty-six patients who had undergone magnetic resonance imaging (MRI) with DWI, in whom the histopathological diagnosis of their gallbladder lesions was confirmed by biopsy or surgery were retrospectively analysed. Thirty-six malignant and 90 benign lesions were included. Two radiologists categorized gallbladder lesions into seven types on two imaging sets [T2-weighted imaging (WI) alone and combined T2WI and DWI (b = 800 s/mm(2))] according to the presence of wall thickening, layered patterns, morphology of the mass, and diffusion restriction. Disagreements were resolved in consensus. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each imaging set for diagnosing gallbladder carcinoma were calculated. The diagnostic performance of each imaging set was calculated using receiver operating characteristic (ROC) curve analysis. Additionally, ADC values of malignant and benign gallbladder lesions were compared separately for 1.5 and 3 T MRI.

RESULTS

The sensitivity, specificity, PPV, and NPV of diagnosis at T2WI were 97.2%, 86.7%, 74.5%, and 98.7%, respectively. The sensitivity, specificity, PPV, and NPV using combined T2WI and DWI were 97.2%, 92.2%, 83.3%, and 98.8%, respectively. Diagnostic accuracy for gallbladder carcinoma slightly improved after adding DWI, from 0.92 to 0.95 (p < 0.05). ADC values for gallbladder carcinoma were significantly lower than those for benign lesions. Mean ADC values of malignant and benign lesions were 0.97 ± 0.25 × 10(-3) and 1.72 ± 0.56 × 10(-3) mm(2)/s, respectively, at 1.5 T (p < 0.001), and 1.04 ± 0.38 × 10(-3) and 2.2 ± 0.72 × 10(-3) mm(2)/s, respectively, at 3 T (p < 0.001).

CONCLUSION

DWI can improve diagnostic accuracy for differentiating benign from malignant gallbladder lesions.

Nuclear medicine tests for acute gastrointestinal conditions

Acute cholecystitis (AC) and lower-gastrointestinal (GI) bleeding are 2 emergencies commonly encountered in nuclear medicine. Evidence of AC on hepatobiliary scintigraphy (HBS) allows for confident diagnosis and provides support for definitive surgical treatment. Proper patient preparation is essential for HBS including fasting and the use of pharmacologic adjuncts is sometimes required. Pharmacologic adjuncts may also be administered during HBS to shorten the length of the examination and increase its specificity. In the interpretation of HBS, there are several sources of false-positive results to be aware of, most commonly chronic cholecystitis. False-negative results on HBS are usually the result of mistaking another structure, such as a dilated cystic duct, for the gallbladder. Abdominal ultrasound is the appropriate initial test in patients with suspected AC, but HBS is an excellent second tier test for the diagnosis of AC in the work-up of indeterminate cases by sonography. GI bleeding scintigraphy plays an important role in the evaluation and management of patients with acute lower-GI bleeding. Scintigraphy serves to localize sites of active GI bleeding and stratify those patients who would benefit from aggressive treatment (surgery or arteriography) vs those who can be managed medically. Pretest involvement of respective services is critical for successful bleeding site confirmation and therapy by interventional radiology or surgery or both. Single photon emission computed tomography/computed tomography erythrocyte scintigraphy has demonstrated superior accuracy and precision over planar scintigraphy in the diagnosis of acute GI bleeding. Additionally, single photon emission computed tomography/computed tomography scintigraphy of GI bleeding provides useful supplemental anatomical information that benefits patient management.

Oedema of gallbladder wall: correlation with chronic hepatitis B on MR imaging

PURPOSE

The aim of this study was to characterise gallbladder wall oedema and correlate it with chronic hepatitis B (CHB) on magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Sixty-seven patients who were clinically and histologically diagnosed with CHB and 18 healthy individuals without any history of liver disease underwent abdominal MR imaging. Hepatic inflammation (grade 0-4) and fibrosis (stage 0-4) for patients were assessed histologically. Gallbladder wall oedema was noted.

RESULTS

Twelve patients showed gallbladder wall oedema on MR imaging, including six with grade 3 and six with grade 4 disease. There was a statistically significant difference for the presence of gallbladder wall oedema among groups with grade 0-4 (p=0.000), but not between groups with grades 3 and 4 (p=0.729). Gallbladder wall oedema was related to moderate-severe inflammatory activity (p<0.05), alanine transaminase (ALT) (p=0.012) and aspartate aminotransferase (AST) (p=0.027) levels but not to fibrosis or other laboratory data, including serum quantitative DNA for hepatitis B virus (HBV), with the p=0.105-0.846. Sensitivity and specificity for the diagnosis of hepatic moderate-severe inflammation using gallbladder wall oedema were 33.33% and 100%, respectively.

CONCLUSIONS

Gallbladder wall oedema for patients with CHB can be specifically demonstrated on MR imaging and is correlated with hepatic moderate-severe inflammatory activity, elevated ALT and AST levels but not with fibrosis or other laboratory data, including viremia.

Differentiating xanthogranulomatous cholecystitis from wall-thickening type of gallbladder cancer: added value of diffusion-weighted MRI

AIM

To evaluate the benefit of diffusion-weighted imaging (DWI) in differentiating xanthogranulomatous cholecystitis from the wall-thickening type of gallbladder cancer.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board. Fourteen patients with xanthogranulomatous cholecystitis and 19 patients with the wall-thickening type of gallbladder cancer were included. Qualitative (visual diffusion restriction compared to liver parenchyma) and quantitative [apparent diffusion coefficient (ADC)] analyses were performed. Conventional MRI findings including dynamic enhancement pattern between the two groups were also analysed. Two observers independently reviewed conventional magnetic resonance imaging (MRI) images and subsequently reviewed combined conventional MRI and DWI images. Pairwise comparison of the receiver operating characteristic (ROC) curves was used to compare diagnostic performances.

RESULTS

In conventional MRI findings, xanthogranulomatous cholecystitis showed significant continuity of enhancing mucosal line [79% (11/14) versus 26% (5/19), p = 0.003] and intramural T2-high signal intensity [64% (9/14) versus 21% (4/19), p = 0.012] compared to the wall-thickening type of gallbladder cancer. The enhancement pattern of gallbladder cancer compared to liver parenchyma showed earlier onset than that of xanthogranulomatous cholecystitis (p = 0.001). Diffusion restriction was more frequently seen in the wall-thickening type of gallbladder cancer (68%, 13/19) than in xanthogranulomatous cholecystitis (7%, 1/14; p < 0.001). The mean ADC value of xanthogranulomatous cholecystitis was higher than that of the wall-thickening type of gallbladder cancer with statistical significance (1.637 × 10(-3) mm(2)/s versus 1.076 × 10(-3) mm(2)/s, p = 0.005). Diagnostic performance [area under ROC curve (Az)] of both observers improved significantly after additional review of DWI; Az improved from 0.737 to 0.930 (p = 0.027) for observer 1 and from 0.675 to 0.938 (p = 0.008) for observer 2.

CONCLUSION

Addition of DWI to conventional MRI improves discrimination between xanthogranulomatous cholecystitis and the wall-thickening type of gallbladder cancer.

Role of diffusion-weighted magnetic resonance imaging in the diagnosis of gallbladder cancer

PURPOSE

To determine the additional diagnostic value of high b-value diffusion-weighted imaging (DWI) compared to conventional biliary magnetic resonance imaging (MRI) for differentiating gallbladder (GB) cancer from benign GB diseases with wall thickening.

MATERIALS AND METHODS

Thirty-nine patients with GB cancers and 36 patients with cholecystitis having preoperative biliary MRIs were included. All patients underwent unenhanced T1- and T2-weighted imaging (T2WI), Gd-enhanced dynamic MRI, and DWI (b values 0, 100, 500, 1000 s/mm(2) ). Two radiologists independently analyzed two sets of MRI for characterization of GB lesions: a conventional biliary image (CBI) set with T1- and T2WI and a dynamic image; and a DWI set composed of DWI and a CBI set. Diagnostic accuracy and sensitivity were evaluated using the receiver operator characteristic method. The mean apparent diffusion coefficient (ADC) values of the lesions were also calculated.

RESULTS

The Az values were 0.856 and 0.960 for reviewers 1 and 2, respectively, with the CBI set and increased to 0.952 and 0.983 with the DWI set. The mean ADC value of GB carcinoma was 1.46 ± 0.45 × 10(-3) mm(2) /s and that of cholecysititis was 2.16 ± 0.56 × 10(-3) mm(2) /s (P < 0.0001).

CONCLUSION

Adding DWI to the standard biliary MRI protocol may improve sensitivity for distinguishing GB cancers from benign GB diseases with wall thickening.

Hepatobiliary scintigraphy in acute cholecystitis

Hepatobiliary scintigraphy is a mature imaging technique for evaluation of patients with acute cholecystitis (AC). It is effective in calculous and acalculous forms of AC. The test is used in contemporary medical practice as the arbiter when the findings from screening abdominal ultrasound do not fit a clinical picture. It is also performed in severely ill patients who have AC suspected on other testing, but whose frail condition and high operative risk demand the highest level of certainty. This review, therefore, examines all technique variations of hepatobiliary scintigraphy, offering an approach that may best fit a variety of clinical situations and philosophies on AC.

The varying faces of gall bladder carcinoma: pictorial essay

The objective of this review is to highlight the pertinent imaging features and potential pitfalls in the diagnosis and staging of gall bladder carcinoma. This condition is notoriously non-specific on imaging on many occasions, particularly in its early stages; gall bladder carcinoma shows numerous features that overlap with a large number of benign conditions, leading to delayed diagnosis and incurable disease. Radiologists should be familiar with its typical and atypical imaging features.

Urgent MRI with MR cholangiopancreatography (MRCP) of acute cholecystitis and related complications: diagnostic role and spectrum of imaging findings

Acute cholecystitis, which is usually associated with gallstones, is one of the commonest surgical causes of emergency hospital admission and may be further complicated by mural necrosis, perforation, and abscess formation. Magnetic resonance imaging (MRI) is increasingly available in the emergency setting. Technically improved equipment and faster acquisition protocols allow excellent tissue contrast and MRI is now an attractive modality for imaging acute abdominal disorders. The use of MRI with MR cholangiopancreatography in the emergency setting provides rapid, noninvasive, and confident diagnosis or exclusion of acute cholecystitis and of coexistent choledocholithiasis. To familiarize the reader with these cross-sectional imaging appearances, this paper reviews MRI findings consistent with uncomplicated cholecystitis. These include gallbladder distension, intraluminal sludge and gallstones, impacted stones obstructing the gallbladder neck or cystic duct, thickening of the gallbladder wall, abnormal signal intensity and edematous stratification, and pericholecystic and perihepatic fluid, plus increased enhancement of the gallbladder wall and adjacent liver parenchyma when intravenous paramagnetic contrast is used. Furthermore, MRI allows prompt detection and comprehensive visualization and characterization of cholecystitis-related complications such as gangrene, perforation, pericholecystic abscess, and intrahepatic fistulization. Some previous literature reports, and our experience, suggest that, when available, MRI should be recommended to provide prompt and efficient triage of patients with suspected cholecystitis and inconclusive clinical, laboratory, and sonographic findings. It facilitates appropriate therapeutic planning, including the timing of surgery (emergency or delayed), approach (laparoscopic or laparotomic), and need for preoperative or intraoperative removal of stone(s) in the common bile duct.

Differentiating malignant from benign thickening of the gallbladder wall by the use of acoustic radiation force impulse elastography

OBJECTIVES

The purpose of this study was to determine whether real-time elastography can differentiate gallbladder carcinoma from benign gallbladder wall thickening.

METHODS

Sonographic and real-time elastographic examinations were done in 125 of 2000 consecutive patients who had an increased gallbladder wall thickness of more than 3 mm. Shear wave velocities were determined for a normal gallbladder wall, a benign thickened gallbladder wall, and gallbladder carcinoma, and a value of 2.7 m/s was set as the cutoff to differentiate between benign and malignant wall thickening. Virtual touch and color maps of the gallbladder wall were also obtained. The final diagnosis was confirmed by histopathologic examination of the resected gallbladder or by guided fine-needle aspiration cytologic examination. Statistical analysis was done to determine the sensitivity and specificity of elastography for gallbladder carcinoma and benign wall thickening. Student t test and area under the receiver operating characteristic curve analyses were done to determine the statistical significance of the results.

RESULTS

Elastography had sensitivity and specificity of 100% and 91.3%, respectively, for diagnosing gallbladder carcinoma with a mean shear wave velocity of 3.41 m/s (P < .0001) and an area under the curve of 0.92. False-positive findings of acute cholecystitis occurred in 8.5% of cases, which also had an increased shear wave velocity of greater than 2.7 m/s. The overall accuracy of elastography for differentiating gallbladder carcinoma from benign wall thickening was 92.8%.

CONCLUSIONS

Elastography is an accurate technique for differentiating between benign and malignant gallbladder wall thickening and can be combined with sonography as the prime imaging tool for diagnosing gallbladder carcinoma at an early stage.

Adenomyomatosis of the gallbladder--case report

Adenomyomatosis of the gallbladder is a benign, mostly asymptomatic condition of an unknown aetiology. Hyperplastic changes in the gallbladder wall cause an overgrowth of the mucosa, thickening of the muscular wall, and formation of intramural diverticula or sinus tracts termed Rokitansky-Aschoff sinuses. Adenomyomatosis is divided on general, segmental and localised. Ultrasound examination, computerized tomography and magnetic resonance are used in diagnostic procedure. The importance of the disease lies in the fact that it can cause recurrent right upper quadrant pain so it must be concerned in resolving pain cause. This paper was aimed at explaining the aetiology of the disease, its clinical manifestation, making diagnosis and therapy in order to make its diagnosis and treatment possible.

Gallbladder imaging

The treatment of gallbladder disease has been revolutionized by improvements in laparoscopic surgery as well as endoscopic and radiologic interventional techniques. Therapeutic success is dependent on accurate radiologic assessment of gallbladder pathology. This article describes recent technical advances in ultrasonography, multidetector computed tomography, magnetic resonance imaging, positron emission tomography, and scintigraphy, which have significantly improved the accuracy of noninvasive imaging of benign and malignant gallbladder disease. The imaging findings of common gallbladder disorders are presented, and the role of each of the imaging modalities is placed in perspective for optimizing patient management.

Gallbladder abnormalities in carcinoma of pancreatic head: findings on MR imaging

BACKGROUND

Our objective is to study the gallbladder abnormalities on MR images associated with carcinoma of the pancreatic head.

METHODS

Thirty-six patients who had surgical resection of pancreatic head carcinoma were retrospectively analyzed regarding the appearance of the tumor and gallbladder on MR imaging performed within one month before surgery. The changes of the gallbladder wall, and the dimension of the gallbladder, cystic duct, pericholecystic region, and common bile duct (CBD) on MR imaging were noted.

RESULTS

About 92% (33/36) of patients had at least one gallbladder abnormality on MR imaging, including thickened gallbladder wall (58%), gallbladder wall striation (19%), gallbladder wall severe enhancement (44%), enlarged gallbladder (33%), gallbladder stone (19%), dilatation of cystic duct (67%), focally increased liver parenchymal enhancement adjacent to the gallbladder (19%), and pericholecystic fluid (11%). 64% of patients had dilated CBD. The diameter of the cystic duct was correlated with those of the CBD (r = 0.45, P < 0.01) and gallbladder (r = 0.56, P < 0.0001). Enlarged gallbladder, dilatation of the cystic duct, and CBD were correlated with chronic cholecystitis.

CONCLUSION

Most patients with pancreatic head carcinoma show gallbladder abnormalities on MR imaging. Cystic duct dilatation follows CBD dilatation and is the primary cause for dilated gallbladder and chronic cholecystitis in carcinoma of pancreatic head.

Analysis of enhancement pattern of flat gallbladder wall thickening on MDCT to differentiate gallbladder cancer from cholecystitis

OBJECTIVE

The objective of our study was to determine the diagnostic value of analyzing the pattern of gallbladder wall enhancement on MDCT to characterize diffuse gallbladder wall thickening as benign or malignant.

MATERIALS AND METHODS

MDCT scans obtained during the portal venous phase in 78 patients with gallbladder wall thickening caused by various pathologic conditions were retrospectively reviewed by two blinded observers. The CT features of benign and malignant gallbladder wall thickening were compared by means of univariate and multivariate analyses. The study cases were then divided into five patterns according to enhancement pattern. Using these five patterns, two radiologists reviewed the MDCT images and recorded their diagnostic confidence for differentiating benign versus malignant cause on a 5-point scale. The diagnostic performance of CT was evaluated by each observer using a receiver operating characteristic curve analysis.

RESULTS

The thicknesses of the inner and outer layers ("thick" enhancing inner layer > or = 2.6 mm, "thin" outer layer < or = 3.4 mm), strong enhancement of the inner wall, and irregular contour of the affected wall were significant predictors for a malignant cause of gallbladder wall thickening (p < 0.001). The two-layer pattern with a strongly enhancing thick inner layer and weakly enhancing or nonenhancing outer layer and the one-layer pattern with a heterogeneously enhancing thick layer were patterns that were significantly associated with gallbladder cancer (p < 0.05). When we consider those two enhancing patterns as a sign of malignancy, the diagnostic accuracy of MDCT was 89.1% and 87.6% for the two observers, respectively.

CONCLUSION

Analyzing the enhancement pattern of a thickened gallbladder wall on MDCT is helpful in differentiating gallbladder cancer from benign inflammatory diseases.

Imaging of adenomyomatosis of the gall bladder

Adenomyomatosis is a relatively common abnormality of the gall bladder, with a reported incidence of between 2.8 and 5%. Although mainly confined to the adult study group, a number of cases have been reported in the paediatric study group. It is characterized pathologically by excessive proliferation of the surface epithelium and hypertrophy of the muscularis propria of the gall bladder wall, with invagination of the mucosa into the thickened muscularis forming the so-called 'Rokitansky-Aschoff' sinuses. The condition is usually asymptomatic and is often diagnosed as an incidental finding on abdominal imaging. The radiological diagnosis is largely dependent on the visualization of the characteristic Rokitansky-Aschoff sinuses. As the condition is usually asymptomatic, the importance of making a correct diagnosis is to prevent misinterpretation of other gall bladder conditions such as gall bladder cancer, leading to incorrect treatment. In the past, oral cholecystography was the main imaging method used to make this diagnosis. In most institutions, oral cholecystography is no longer carried out, and the diagnosis is now more commonly seen on cross-sectional imaging. In this review article, we describe the manifestations of adenomyomatosis on the various imaging methods, with an emphasis on more modern techniques such as magnetic resonance cholangiopancreatography. A brief section on oral cholecystography to aid readers familiar with this technique in understanding the comparable imaging features on more modern imaging techniques is included.