Radiologic diagnosis of adenomyomatosis of the gallbladder: comparative study among MRI, helical CT, and transabdominal US

Grayscale ultrasonography findings for characterization of gallbladder wall thickening in non-acute setting: a systematic review and meta-analysis

BACKGROUND

The accurate characterization of gallbladder wall thickening (GWT) into benign or malignant on ultrasound (US) is a significant challenge.

METHODS

We searched the MEDLINE and EMBASE databases for studies reporting two-dimensional grayscale US in benign and malignant GWT. The pooled prevalence was calculated using a generalized linear mixed method with a random-effects model. The pooled sensitivity and specificity were calculated using a bivariate random-effects model.

RESULTS

Of the 7309 studies screened by titles, 73 studies with 18,008 patients were included. The most common findings in xanthogranulomatous cholecystitis (XGC) were lack of wall disruption and intramural hypoechoic nodules while adenomyomatosis (ADM) was frequently associated with intramural cysts and intramural echogenic foci. Echogenic foci, lack of gallbladder wall disruption, and hypoechoic nodules had a sensitivity of 89%, 77%, and 66% and specificity of 86%, 51%, and 80%, respectively for the diagnosis of benign GWT. Focal thickening and indistinct liver interface had a sensitivity of 75% and 55% and specificity of 64% and 69%, respectively for the diagnosis of malignant GWT.

CONCLUSION

intramural features (echogenic foci, hypoechoic nodules), gallbladder wall disruption, and liver interface are useful US features for the characterization of GWT.

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.

Contrast-enhanced ultrasonography in differential diagnosis of focal gallbladder adenomyomatosis and gallbladder cancer

BACKGROUND

Focal gallbladder adenomyomatosis (ADM) is a common disease that mimics gallbladder cancer (GBC) on ultrasonography.

OBJECTIVE

Here we aim to assess the value of contrast-enhanced ultrasound (CEUS) in differentiating ADM from GBC.

METHODS

Forty-one histopathologically proven focal ADMs and 34 GBCs (≤T2 stage) were enrolled in the study. Lesion location, blood flow signals, contrast pattern and appearance on contrast-enhanced ultrasound (CEUS) were compared respectively.

RESULTS

Lesions were detected in fundus, body, neck at the rates of 61.0% (25/41), 26.8% (11/41) and 12.2% (5/41), respectively, in ADM patients, in comparison to 29.4% (10/34), 32.4% (11/34) and 38.2% (13/34), respectively, in GBC patients (p = 0.009). Blood flow signals were detected in 19.5% (8/41) of cases in ADMs, compared to 58.8% (20/34) in GBCs (p = 0.001). On CEUS, iso-enhancement, hypo-enhancement, intramural anechoic space and intactness of GB wall were detected in 41.5% (17/41), 39.0% (16/41), 56.1% (23/41) and 80.5% (33/41) cases of ADMs, in contrast to 17.6% (6/34), 20.6% (7/34), 20.6% (7/34) and 17.6% (6/34) of GBCs (p = 0.001, p = 0.001, p = 0.002, p < 0.001, respectively). The prior Youden's index were 0.81 based on intactness of GB wall on CEUS.

CONCLUSION

Combined with CEUS helps improve the differential diagnosis accuracy of focal gallbladder ADMs.

Pathogenesis of gallbladder adenomyomatosis and its relationship with early-stage gallbladder carcinoma: an overview

The exact pathogenesis of gallbladder adenomyomatosis is still lacking and some controversies over its diagnosis and treatment exist. Originally recognized as a precancerous lesion, adenomyomatosis is currently recognized by recent studies as a benign alteration of the gallbladder that is often associated with cholecystitis and cholecystolithiasis. Gallbladder carcinoma is an extremely malignant disease with a 5-year survival rate of less than 5%. Therefore, it is important to diagnose, differentiate, and confirm the relationship between adenomyomatosis and early-stage gallbladder carcinoma. However, the early clinical symptoms of adenomyomatosis are extremely similar to those of gallbladder stones and cholecystitis, increasing the difficulty to identify and treat this disease. This article summarizes the research progress on gallbladder adenomyomatosis, aiming to improve the understanding of the pathogenesis of adenomyomatosis and further provide insight for its clinical diagnosis and treatment.

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.

Gallbladder adenomyomatosis: imaging findings, tricks and pitfalls

Abstract

Gallbladder adenomyomatosis (GA) is a benign alteration of the gallbladder wall that can be found in up to 9% of patients. GA is characterized by a gallbladder wall thickening containing small bile-filled cystic spaces (i.e., the Rokitansky–Aschoff sinuses, RAS). The bile contained in RAS may undergo a progressive concentration process leading to crystal precipitation and calcification development. A correct characterization of GA is fundamental in order to avoid unnecessary cholecystectomies. Ultrasound (US) is the imaging modality of choice for diagnosing GA; the use of high-frequency probes and a precise focal depth adjustment enable correct identification and characterization of GA in the majority of cases. Contrast-enhanced ultrasound (CEUS) can be performed if RAS cannot be clearly identified at baseline US: RAS appear avascular at CEUS, independently from their content. Magnetic resonance imaging (MRI) should be reserved for cases that are unclear on US and CEUS. At MRI, RAS can be identified with extremely high sensitivity, but their signal intensity varies widely according to their content. Positron emission tomography (PET) may be helpful for excluding malignancy in selected cases. Computed tomography (CT) and cholangiography are not routinely indicated in the suspicion of GA.

Teaching points

1. Gallbladder adenomyomatosis is a common benign lesion (1–9% of the patients).

2. Identification of Rokitansky–Aschoff sinuses is crucial for diagnosing gallbladder adenomyomatosis.

3. Sonography is the imaging modality of choice for diagnosing gallbladder adenomyomatosis.

4. Intravenous contrast material administration increases ultrasound accuracy in diagnosing gallbladder adenomyomatosis.

5. Magnetic resonance is a problem-solving technique for unclear cases.

Three-Dimensional Sonography of Biliary Tract Disorders

In this pictorial essay, we review the 3-dimensional sonographic appearance of the normal gallbladder and biliary tree, as well as the appearance of congenital and acquired biliary tract disorders. Using examples, we demonstrate the advantage of 3-dimensional scanning compared with 2-dimensional sonography and, even in certain cases, magnetic resonance cholangiopancreatography.

Tumefactive gallbladder sludge: the MRI findings

AIM

To evaluate the conventional and diffusion-weighted magnetic resonance imaging (MRI) images of tumefactive gallbladder sludge.

MATERIALS AND METHODS

The institutional review board approved this retrospective study. Between January 2006 and January 2015, 3478 patients were diagnosed with gallbladder sludge by ultrasonography (US). Of them, 12 patients (eight male, four female; mean age, 63.6 years) with 12 tumefactive gallbladder sludge lesions, who underwent subsequent MRI for further evaluation within 1 month, were included in this study. Data regarding the clinical features, presence of enhancement, and signal intensities of the T2-, T1-, and diffusion-weighted images were collected.

RESULTS

All cases of tumefactive sludge were detected incidentally. None of the patients had any predisposing factors for biliary sludge. The tumefactive gallbladder sludge was predominantly seen as a well-defined mass-like lesion. It showed hyperintensity on T1-weighted images (91.7%, 11/12), and variable signal intensities on T2-weighted images. Most of the tumefactive sludge lesions showed no enhancement on the dynamic phases (90%, 9/10). There were no cases with diffusion restriction. Among the patients with follow-up US data (n=7), all the lesions were found to have either disappeared or decreased in size.

CONCLUSION

Although tumefactive gallbladder sludge on US can mimic gallbladder cancer, its hyperintensity on a T1-weighted image, and the absence of enhancement and diffusion restriction on MRI images can be helpful for differentiating it from a tumorous condition.

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.

Contrast-enhanced ultrasonography diagnosis of fundal localized type of gallbladder adenomyomatosis

Background

Adenomyomatosis of gallbladder is an acquired hyperplastic lesion, characterized by focal or diffuse thickening of the gallbladder with intramural cysts or echogenic areas with comet tail on ultrasonography. But in some cases, especially in the localized fundal type of adenomyomatosis, the intramural anechoic cystic spaces are uncertainty which causes difficult to differential adenomyomatosis from GB cancer. The purpose of this study was to determine the accuracy of real-time contrast-enhanced ultrasonography(CEUS) in the diagnosis of the fundal localized type of gallbladder adenomyomatosis.

Methods

We performed a retrospective study of 21 patients with pathologically proven fundal localized type of gallbladder (GB) adenomyomatosis. All patients underwent preoperative grayscale ultrasound (US) and real-time CEUS examination. The study’s reviewers made the diagnosis of adenomyomatosis according to the presence of the focal thickening of the fundal gallbladder wall with intramural cyst or intramural echogenic foci on grayscale US or CEUS. The diagnostic accuracy of US and CEUS was compared. The enhanced pattern and degree of intactness of the GB wall were also recorded.

Results

The fundal portion of the GB wall showed localized thickness in all 21 patients. Small anechoic spaces or intramural echogenic foci were detected in 14 (66.7 %) and 21 (100 %) of cases respectively, and the intactness of the GB wall’s outer hyper-echoic layer was demonstrated in 17 (81 %) and 20 (95 %) on grayscale US and CEUS, respectively. The accuracy rate of the above two examination modalities was significantly different (p < 0.05). In the arterial phase of the CEUS, areas of focal thickened GB wall were iso-enhanced in 18 cases and hyper-enhanced in 3 cases. All 21 cases appeared to show heterogeneous enhancement with small non-enhancement spaces. The mucosal and serosal layers of the GB wall surrounding the lesions were enhanced, which presented as two “hyper-echoic lines” in the arterial phase of CEUS. In the venous phase of the CEUS, 19 lesions were iso-enhanced and 2 lesions were hypo-enhanced. The small non-enhancement spaces were more clearly during the venous phase.

Conclusion

The small non-enhancement space is a characteristic finding of the fundal localized type of gallbladder adenomyomatosis on CEUS. CEUS could increase the degree of visualization of Rokitansky-Aschoff sinuses (RAS) and intactness of the GB wall, which play an important role in differential diagnosis.

Differential diagnosis of gallbladder wall thickening: the usefulness of contrast-enhanced ultrasound

he purpose of this study was to evaluate the usefulness of contrast-enhanced ultrasound (CEUS) in the differential diagnosis of gallbladder wall (GBW) thickening and determine the predictors of malignant GBW thickening. One hundred fifty-nine patients with GBW thickening, including 76 men and 83 women, from eight institutions were enrolled. CEUS was performed after injection of a sulfur hexafluoride microbubble-based ultrasound contrast agent. Multiple logistic regression analysis was used to reveal independent predictor sassociated with malignant GBW thickening. The final diagnoses were 48 gallbladder carcinomas and 111 benign gallbladder diseases.Maximal thicknesses of the GBW in malignant and benign GB Wthickening were 17.3 ± 5.2 (6 – 30) mm and 8.6 ± 5.1 (4 – 26) mm respectively (p , 0.001). CEUS revealed significant differences in intralesional vessels, enhancement homogeneity, time to hypo-enhancement, inner layer discontinuity, outer layer discontinuity and adjacent liver involvement (all p-values , 0.05) between malignant and benign GBW thickening. Patient age . 46.5 y, focal GBW thickening, inner layer discontinuity and outer layer discontinuity were found to be associated with malignancy by multiple logistic regression analysis (all p-values , 0.05). Receiver operating characteristic curve analysis revealed Az values for patient age, focal GBW thickening, inner wall discontinuity and outer wall discontinuity of 0.709 (95%confidence interval [CI]: 0.627–0.790), 0.714 (95% CI: 0.630–0.798), 0.860 (95%CI: 0.791 – 0.928) and 0.858 (95% CI: 0.783 – 0.933), respectively. CEUS is useful in the differential diagnosis between malignant and benign GBW thickening. Focal GBW thickening, inner wall discontinuity and outer wall discontinuity observed on CEUS are diagnostic clues for malignant GBW thickening.

Differentiating between adenomyomatosis and gallbladder cancer: revisiting a comparative study of high-resolution ultrasound, multidetector CT, and MR imaging

Objective

To compare the diagnostic performance of high-resolution ultrasound (HRUS) with contrast-enhanced CT and contrast-enhanced magnetic resonance imaging (MRI) with MR cholangiopancreatography (MRCP) to differentiate between adenomyomatosis (ADM) and gallbladder cancer (GBCA).

Materials and Methods

Forty patients with surgically proven ADM (n = 13) or GBCA at stage T2 or lower (n = 27) who previously underwent preoperative HRUS, contrast-enhanced CT, and contrast-enhanced MRI with MRCP were retrospectively included in this study. According to the well-known diagnostic criteria, two reviewers independently analyzed the images from each modality separately with a five-point confidence scale. The interobserver agreement was calculated using weighted κ statistics. A receiver operating characteristic curve analysis was performed and the sensitivity, specificity, and accuracy were calculated for each modality when scores of 1 or 2 indicated ADM.

Results

The interobserver agreement between the two reviewers was good to excellent. The mean Az values for HRUS, multidetector CT (MDCT), and MRI were 0.959, 0.898, and 0.935, respectively, without any statistically significant differences between any of the modalities (p > 0.05). The mean sensitivity of MRI with MRCP (80.8%) was significantly higher than that of MDCT (50.0%) (p = 0.0215). However, the mean sensitivity of MRI with MRCP (80.8%) was not significantly different from that of HRUS (73.1%) (p > 0.05). The mean specificities and accuracies among the three modalities were not significantly different (p > 0.05).

Conclusion

High-resolution ultrasound and MRI with MRCP have comparable sensitivity and accuracy and MDCT has the lowest sensitivity and accuracy for the differentiation of ADM and GBCA.

Focal thickening at the fundus of the gallbladder: computed tomography differentiation of fundal type adenomyomatosis and localized chronic cholecystitis

Background/Aims

The objective of our study was to identify useful computed tomography (CT) findings for differentiating fundal type adenomyomatosis from localized chronic cholecystitis involving the fundus of the gallbladder.

Methods

We retrospectively identified cases of 41 patients with pathologically proven adenomyomatosis (n=21) or chronic cholecystitis (n=20) who had fundal thickening of the gallbladder on preoperative abdominal CT. Analysis of the CT findings included evaluation of the thickness, contour, border, intralesional cystic area, adjacent gallbladder wall thickening, presence of inner layer enhancement, enhancement grade, enhancement pattern, and presence of stones. Statistical analyses were performed using the Mann-Whitney U test and Fisher exact test.

Results

Oval contour, inner layer enhancement and intralesional cystic area were more frequently noted in adenomyomatosis than in chronic cholecystitis (p<0.05 for each finding). Flat contour and adjacent gallbladder wall thickening were more frequently observed in chronic cholecystitis than in adenomyomatosis. No differences between adenomyomatosis and chronic cholecystitis in terms of the thickness, enhancement grade, enhancement pattern and presence of stones were apparent.

Conclusions

CT may help to differentiate fundal type adenomyomatosis from localized chronic cholecystitis involving the fundus of the gallbladder.

Stepwise approach and surgery for gallbladder adenomyomatosis: a mini-review

BACKGROUND

Gallbladder adenomyomatosis (GBA) is a hyperplastic disease affecting the wall of the gallbladder, with some typical features. It has historically been considered a benign condition, nevertheless recent reports highlighted a potential role of GBA in predisposing to malignancies of the gallbladder.

DATA SOURCES

We reviewed the literature concerning GBA from its identification until July 2012. Owing to the relative rarity of the disease, studies often are case reports or case series. Thus we herein report a summary of the key-points concerning diagnosis and treatment of GBA, easily applicable in everyday practice, rather than a systematic review. Also, results are integrated with our recent experience.

RESULTS

In our experience, we observed a trend toward an increase of GBA during the last years, probably due to enhanced ultrasonographic technical advancements and physician's expertise. GBA has distinctive imaging features. Several recent reports highlight the potential risk of cancer associated with GBA; however the disease is still classified as a benign condition. Although its correlation with malignancy has not been demonstrated, it is prudent to recommend cholecystectomy in some cases. However, in selected asymptomatic patients, a wait-and-see policy is a viable alternative. We propose an algorithm, based on GBA pathological pattern (diffuse, segmental, localized or fundal), suitable for decision-making.

CONCLUSIONS

In symptomatic patients and if the diagnosis is doubtful, cholecystectomy is mandatory. Postponing surgery is an option to be offered to asymptomatic patients with low-risk GBA pattern who adhere to scheduled follow-ups.

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.

Differentiation of adenomyomatosis of the gallbladder from early-stage, wall-thickening-type gallbladder cancer using high-resolution ultrasound

OBJECTIVES

To evaluate the diagnostic performance of transabdominal high-resolution ultrasound (HRUS) for differentiation of adenomyomatosis from early-stage, wall-thickening-type gallbladder (GB) cancer.

METHODS

HRUS was defined as the addition of high megahertz imaging to conventional low megahertz imaging with use of state-of-the-art imaging technology. HRUS findings were retrospectively compared in 45 patients with adenomyomatosis and 28 patients with stage T1/T2 wall-thickening-type GB cancer. For evaluating HRUS performance in the differential diagnosis of adenomyomatosis from GB cancer, receiver operating characteristic curve analysis was used with a five-point confidence scale independently scored by three blinded radiologists who also analysed morphological abnormalities.

RESULTS

The area under the receiver operating characteristic curve (A (z)) values of HRUS in the diagnosis of adenomyomatosis were 0.948, 0.915 and 0.917 for reviewers 1, 2 and 3. Symmetrical wall thickening, intramural cystic spaces, intramural echogenic foci and twinkling artefacts were significantly associated with adenomyomatosis (P < 0.05), whereas irregular thickening of the outer wall, focal innermost hyperechoic layer (IHL) discontinuity, IHL irregularity, IHL thickening greater than 1 mm, loss of multilayer pattern in the GB wall, and intralesional vascularity were significantly associated with cancer (P < 0.05). The sensitivity, specificity and accuracy of intramural cystic spaces/echogenic foci for the diagnosis of adenomyomatosis were 80.0 %, 85.7 % and 82.2 %.

CONCLUSIONS

This study showed that HRUS can be helpful for distinguishing adenomyomatosis from early-stage, wall-thickening-type GB cancer.

Magnetic resonance differentiation between T2 and T1 gallbladder carcinoma: significance of subserosal enhancement on the delayed phase dynamic study

PURPOSE

The aim of this study is to investigate whether subserosal enhancement on the delayed-phase dynamic magnetic resonance (MR) study (SED) can differentiate T2 from T1 gallbladder carcinoma (GBC).

METHODS

The institutional research board approved this retrospective study. Between 1997 and 2006, there were surgically proven 11 T1 and 21 T2 GBC in 30 patients, all of whom had undergone preoperative contrast enhanced dynamic MR study, either with a 2D sequence (n=17) or 3D sequences (n=15). All images were reviewed by two radiologists for the presence of SED, and receiver operating characteristic (ROC) curve analysis was performed. Sensitivity, specificity, positive and negative predictive values were calculated by consensus.

RESULTS

The areas under the ROC curves of the two readers were 0.91 and 0.86, and the kappa value was 0.78. Of the 21 T2 GBC, 18 and 3 showed positive and negative SED, respectively. Of the 11 T1 GBC, 1 and 10 showed positive and negative SED, respectively. The sensitivity, specificity, positive and negative predictive values of SED for diagnosing T2 lesions were 86%, 88%, 91% and 77%, respectively.

CONCLUSIONS

In conclusion, SED may be a useful sign to differentiate T2 from T1 GBC, which would affect the preoperative surgical planning of the patients.

Adenomyomatosis of the gallbladder: the "good omen" comet

BACKGROUND

As emergency physicians perform bedside ultrasound with greater frequency, greater numbers of incidental and potentially unfamiliar sonographic findings will be encountered.

OBJECTIVES

Illustrate, discuss, and briefly review literature regarding one such finding and diagnosis in right upper quadrant sonography.

CASE REPORT

A middle-aged woman was evaluated in the Emergency Department for abdominal pain. Limited bedside sonography of the gallbladder revealed mural thickening and comet-tailing. A diagnosis of adenomyomatosis was made.

CONCLUSION

Gallbladder adenomyomatosis can produce ultrasound findings similar to those of more serious and emergent gallbladder diseases. Cognizance of the sonographic details and typical clinical characteristics will allow the emergency physician to appropriately assess and disposition patients with this condition.

[Imaging in the diagnosis and the staging of gallbladder tumors]

Most of gallbladder tumors are benign. Adenoma, cholesterol polyps, or adenomyomatosis are most frequently typical on ultrasonographic images. All symptomatic lesions must be considered as indications for surgery. It may be difficult to identify precancerous or malignant lesion. Polyps over 1cm are indication for preventive cholecystectomy. In case of suspicious polyp or suspicious wall thickening, endoscopic ultrasonography can be helpful to evaluate local tumoral spread and eliminate differential diagnosis. Unfortunately, diagnosis of gallbladder cancer is often late, when surgical resection can't be curative. Computed tomography and magnetic resonance imaging examinations are then useful for local and metastatic staging.

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.

MR imaging of the gallbladder: a pictorial essay

The gallbladder serves as the repository for bile produced in the liver. However, bile within the gallbladder may become supersaturated with cholesterol, leading to crystal precipitation and subsequent gallstone formation. The most common disorders of the gallbladder are related to gallstones and include symptomatic cholelithiasis, acute and chronic cholecystitis, and carcinoma of the gallbladder. Other conditions that can affect the gallbladder include biliary dyskinesia (functional), adenomyomatosis (hyperplastic), and postoperative changes or complications (iatrogenic). Ultrasonography (US) has been the traditional modality for evaluating gallbladder disease, primarily owing to its high sensitivity and specificity for both stone disease and gallbladder inflammation. US performed before and after ingestion of a fatty meal may also be useful for functional evaluation of the gallbladder. However, US is limited by patient body habitus, with degradation of image quality and anatomic detail in obese individuals. With the advent of faster and more efficient imaging techniques, magnetic resonance (MR) imaging has assumed an increasing role as an adjunct modality for gallbladder imaging, primarily in patients who are incompletely assessed with US. MR imaging allows simultaneous anatomic and physiologic assessment of the gallbladder and biliary tract in both initial evaluation of disease and examination of the postoperative patient. This assessment is accomplished chiefly through the use of MR imaging contrast agents excreted preferentially via the biliary system.

CT differentiation of adenomyomatosis and gallbladder cancer

OBJECTIVE

The purpose of this study was to determine the accuracy of CT in differentiating adenomyomatosis from gallbladder cancer.

MATERIALS AND METHODS

We retrospectively identified the cases of 36 patients with pathologically proven adenomyomatosis (n = 22) or gallbladder cancer (n = 14) who had undergone preoperative abdominal CT. Two reviewers independently evaluated the presence and nature of morphologic gallbladder abnormalities, including the presence of intramural diverticula (i.e., small cystic-appearing spaces within the gallbladder wall). The reviewers used a five-point scale (1, definitely absent; 5, definitely present) to rate the overall likelihood of the presence of adenomyomatosis and gallbladder cancer. Ratings were dichotomized such that a diagnosis was considered present at a rating of 4 or 5 and considered absent at lower ratings.

RESULTS

Reviewer 1 detected a morphologic gallbladder abnormality in 17 patients and correctly characterized the abnormality in 14 (82%) of the patients (eight with adenomyomatosis and six with gallbladder cancer). Reviewer 2 detected an abnormality in 18 patients and was correct for 13 (72%) of the patients (eight with adenomyomatosis and five with gallbladder cancer). In particular, reviewer 1 detected intramural diverticula in eight patients, and all had the pathologic diagnosis of adenomyomatosis, whereas reviewer 2 detected intramural diverticula in 11 patients, and eight (73%) had the pathologic diagnosis of adenomyomatosis.

CONCLUSION

CT is limited in the detection and differentiation of adenomyomatosis and gallbladder cancer, but the diagnosis of adenomyomatosis can be made with reasonable accuracy when thickening of the gallbladder wall is seen to contain small cystic-appearing spaces.

Gallbladder adenomyomatosis: imaging findings

In this pictorial essay, we describe the imaging findings of adenomyomatosis of the gallbladder and emphasize high-resolution ultrasound and magnetic resonance cholangiopancreatography in its diagnosis.

Imagerie des épaississements de la paroi vésiculaire

Thickening of the gallbladder wall may result from a large spectrum of pathological conditions, intrinsic as well as extrinsic to the biliary tract, and may have different appearances. Accurate diagnosis is usually established after a correlation of imaging findings, laboratory data and clinical history. US remains the initial imaging modality for the evaluation of acute right upper quadrant pain. CT and MRI are complementary to US and have an increasing role in assessing a thickened-wall gallbladder.

Adenomyomatosis of the gallbladder in childhood: report of a case and review of the literature

Adenomyomatosis of the gallbladder is considered an acquired pathologic condition that affects adults, with only 2 cases previously described in childhood. We report on a 5-year-old boy with incidental detection of this lesion by ultrasonography. Pathologic and clinical assessments are discussed in addition to treatment decision-making, including current insights into the relation between adenomyomatosis and malignancy of the gallbladder. The liberal use of ultrasonography in children with abdominal pain may result in detection of an increasing number of asymptomatic patients. Caregivers should be aware of this condition and its therapeutic implications in the pediatric population.

Combined segmental and focal adenomyomatosis involving the body of the gallbladder

Adenomyomatosis (adenomyomatous hyperplasia) of the gallbladder is a benign process of unknown origin that has been classified into three morphologic types: diffuse, segmental, and focal (fundal). Cases of combined (segmental and focal) forms involving the gallbladder body are very rare. We present the sonographic findings of a case having adenomyomatosis of the gallbladder body with focal as well as segmental forms of the disease.

Well-differentiated adenocarcinoma of the gallbladder with intratumoral cystic components due to abundant mucin production: a mimicker of adenomyomatosis

The prevalence and etiology of the cystic components within gallbladder carcinomas as seen on MR images were evaluated. A retrospective review of MR images was performed for 35 proven gallbladder carcinomas in search of radiologically detectable intratumoral cystic components. The pathologic specimens were meticulously reviewed to determine the etiology. MR images of 31 adenomyomatoses were also reviewed for comparison to clarify the difference in MR features between these two entities. Three cases out of 35 proven gallbladder carcinomas were found to have intratumoral cystic components. They were all well-differentiated adenocarcinomas, and the cystic components consisted of dilated neoplastic glands filled with abundant mucin pool. Adenomyomatosis tended to have more and rounded cystic components (Rokitansky-Aschoff sinuses) lined in a linear fashion and were flat-elevated in shape, smaller in size and had a regular surface, as compared to the three carcinomas. Although rare, radiologists need to be aware that well-differentiated gallbladder carcinoma with mucin production can have cystic components, which may mimic adenomyomatosis. Careful interpretation of MR images may provide useful information in the differentiation of these two entities.

The interrupted rim sign in acute cholecystitis: a method to identify the gangrenous form with MRI

We present the imaging findings on MR of a patient with acute gangrenous cholecystitis that demonstrated patchy enhancement of the gallbladder mucosa on gadolinium-enhanced fat-saturated T1-weighted gradient echo images. This interrupted rim of mucosal enhancement correlated with patchy areas of necrosis and inflammation of the gallbladder mucosa on the histopathological examination.

The pearl necklace sign: an imaging sign of adenomyomatosis of the gallbladder at MR cholangiopancreatography

PURPOSE

To evaluate the demonstration of the pearl necklace sign at magnetic resonance (MR) cholangiopancreatography (MRCP) in patients with proven adenomyomatosis and carcinoma of the gallbladder.

MATERIALS AND METHODS

MRCP findings and those of a combination of unenhanced and arterial phase computed tomography (CT) and arterial phase MR imaging were retrospectively compared in 29 patients who were pathologically proven to have adenomyomatosis of the gallbladder and in 18 patients with pathologically proven gallbladder carcinoma. Receiver operating characteristic (ROC) analysis was used with a five-point confidence scale. The relative sensitivity, specificity, and accuracy of each imaging modality were also calculated. The pearl necklace sign was defined on MRCP images as small round foci, with the same markedly high signal intensity as bile, within the thickened wall of the gallbladder.

RESULTS

The mean area under the ROC curve of MRCP alone and that of the combination of MRCP and arterial phase MR imaging was significantly higher than that of combined CT (unenhanced and arterial phase) and arterial phase MR imaging alone (P <.01). The relative sensitivities in the diagnosis of adenomyomatosis of the gallbladder were 24% for the combined CT, 29% for arterial phase MR imaging, 62% for MRCP, and 57% for the combination of MRCP and arterial phase MR imaging. The mean relative sensitivity, specificity, and accuracy of the pearl necklace sign on MRCP images were 62%, 92%, and 74%, respectively. In eight (28%) of 29 patients with adenomyomatosis of the gallbladder, the pearl necklace sign was not identified by all three readers on the MRCP images.

CONCLUSION

The pearl necklace sign, which indicates the presence of Rokitansky-Aschoff sinuses within the thickened gallbladder wall, was specifically detected at MRCP for adenomyomatosis of the gallbladder.

Adenomyomatosis with Marked Subserosal Fibrosis and Lipomatosis of the Gallbladder: Mural Stratification Demonstrated with MR

The authors reported a case of fundal-type adenomyomatosis in which mural stratification corresponding to histopathological findings was clearly demonstrated with MR imaging. Single-shot fast spin echo images for MR cholangiopancreatography clearly visualized Rokitansky-Aschoff sinuses (RAS), which are a diagnostic clue for this disease. However, mural stratification comprising RAS with muscular proliferation, massive fibrosis and subserosal fat deposition was more precisely demonstrated in T(2)-weighted images obtained with fast spin echo.