Imaging benign and malignant disease of the gallbladder

Gallstones Detection on Dual-Energy Computerized Tomography-Is It Ready for Real-World Use? A Retrospective Observational Study

AIMS

The aims of the study are to evaluate the performance of dual-energy computed tomography (DECT) imaging in the detection of noncalcified gallstones (GSs) and to assess its performance relative to transabdominal ultrasound (US) in identifying cholelithiasis.

METHOD

This study is a retrospective review of radiology records and images to find all patients who had both US and DECT scans within a 6-month period and were found to have GSs. Patients who did not have GSs on US served as the control group. The CT scans were reviewed by 4 radiologists who did not have access to the US results when assessing the presence or absence of GSs on the DECT scans. In case of any discrepancies among the radiologists, the majority opinion was considered. If there was a split opinion, a fifth reviewer was consulted. The data were analyzed to calculate sensitivity, specificity, positive and negative predictive values, as well as overall accuracy and to evaluate interreader variability. The absolute Hounsfield unit (HU) differences of the GSs and bile were compared between polychromatic (PC), virtual noncontrast (VNC), and virtual monochromatic (VMC) images.

RESULTS

Considering at least 3-reader agreement, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were found to be 92%, 96%, 96%, 92%, and 94%, respectively. Individual reader sensitivity varied between 87% and 92%. There was good interobserver agreement with a Fleiss' kappa of 0.76. Quantification of the whole data set showed that no significant difference was observed in the HU values for the stones between the PC images and the VNC images. A significant increase was observed on the 50-keV VMC images compared with the PC and VNC images. In the study group, 17% stones were visualized only on the VNC or/and 50-keV VMC images, and not on the PC images. On quantitative analysis of these cases, there was a significant increase of HU in the VNC images as compared with PC images and a significant decrease of HU in the 50-keV VMC images as compared with PC images.

CONCLUSIONS

Low-keV images increase stone-bile contrast. Evaluation of cholelithiasis using VNC and 50-keV VMC images demonstrated a 14% increase in sensitivity relative to conventional CT.

Percutaneous cholecystostomy: techniques and applications

Acute cholecystitis (AC) is a critical condition requiring immediate medical attention and treatment and is one of the most frequently encountered acute abdomen emergencies in surgical practice, requiring hospitalization. Laparoscopic cholecystectomy is considered the favored treatment for patients with AC who are fit for surgery. However, in high-risk patients considered poor surgical candidates, percutaneous cholecystostomy (PC) has been suggested and employed as a safe and reliable alternative option. PC is a minimally invasive, nonsurgical, image-guided intervention that drains and decompresses the gallbladder, thereby preventing its perforation and sepsis. It can act as a bridge to surgery, but it may also serve as a definitive treatment for some patients. The goal of this review is to familiarize physicians with PC and, more importantly, its applications and techniques, pre- and post-procedural considerations, and adverse events.

A retrospective study of diagnosis and management of gallbladder perforation: 10-year experience from a tertiary health care centre

Objectives

The aim of this study was to perform retrospective analysis of data collected from patients of gallbladder perforations for diagnosis, management and outcome.

Material and Methods

A retrospective analysis of data was carried out for 40 patients of gallbladder perforations from the hospital record of patients who were diagnosed preoperatively and intraoperatively as a case of gallbladder perforation over a period of 10 years and were managed in our surgery unit of a tertiary health care centre. Patients were included irrespective of sex except cases of trauma and patients of the paediatric age group.

Results

Among 40 patients, 26 were females and 14 were males. As per Anderson modification of Neimeier classification, 13 (32.5%) had type 1, 23 (57.5%) had type 2, and four (10%) patients had type 3 perforations and none of the patients had type 4 perforation. Twenty-three patients (57.5%) were found to have fundal perforation, followed by body in 11 patients (27.5%), three (7.5%) in Hartman's pouch while in three patients (7.5%), there were multiple perforations. All patients of type 1 Neimer classification were diagnosed clinically as cases of biliary peritonitis, whereas most cases of type 2 Neimer classification were diagnosed preoperatively by CECT abdomen 12/23 patients (52%) and ultrasound abdomen 10/23 (43.47%). All patients underwent surgery, and there were three mortalities.

Conclusion

In our study, there was female predominance in patients having gallbladder perforation. Of the patients, 52.5% were diabetic and mean age was 55.9 years. CECT abdomen was the most useful modality for diagnosis of type 2 gallbladder perforations. Timely surgical intervention is mandatory for a better outcome of these cases.

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.

B-mode ultrasonographic diagnosis in gallbladder wall thickening

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

Differentiation of gallbladder adenomyomatosis from early-stage gallbladder cancer before surgery

Backgrounds/Aims

This study aimed to compare the perioperative and clinical outcomes in patients undergoing laparoscopic cholecystectomy for gallbladder adenomyomatosis (GBA) or early-stage gallbladder cancer (GBC).

Methods

The perioperative and clinical outcomes of 194 patients diagnosed with GBA and 30 patients diagnosed with GBC who underwent laparoscopic cholecystectomy in our institution from January 2011 to December 2017 were retrospectively compared.

Results

There were no significant differences between the GBA and GBC groups in sex (male:female ratio 1.0:0.8 vs. 1.0:0.7, p=0.734), BMI (23.9±3.4 vs. 24.0±3.8 kg/m², p=0.916), or preoperative liver function tests. Patients in the GBC group were significantly older (50.5±14.1 vs. 65.9±10.6 years, p<0.001) and had a higher ASA grade (40.3 vs. 63.4% grade II or III, p=0.043) than patients in the GBA group. Although there was no significant difference in preoperative diagnostic methods (p=0.442), the GBC group showed a significantly higher rate of misdiagnosis on preoperative imaging compared with postoperative histopathologic findings (30.9% vs. 53.3%, p=0.011). There were significantly more patients with gallstones in the GBA group than in the GBC group (68.6% vs. 40.0%, p=0.004).

Conclusions

In older patients hospitalized for biliary colic without gallstones but with a thickened gallbladder wall with inflammation on preoperative diagnostic exam, the possibility of early-stage GBC should be considered.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

KEY POINTS

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

Embryology, Anatomy, and Imaging of the Biliary Tree

"The anatomy of the biliary tree is notoriously variable. This variation is the bane of the hepatobiliary surgeon, to whom an understanding of biliary anatomic variation is key to the planning and safe conduct of liver surgery, from oncological resections to split-liver transplantation. The hepatic diverticulum, also termed "the liver bud," is the first semblance of the biliary system in the human embryo. A variety of techniques used in the mid twentieth century for imaging the biliary tree have since been abandoned in favor of more practical, safer, less invasive, and more sensitive and specific contemporary methods."

Uncommon Intraluminal Tumors of the Gallbladder and Biliary Tract: Spectrum of Imaging Appearances

Intraluminal pathologic conditions of the bile ducts and gallbladder are common, most frequently consisting of calculi and adenocarcinoma. In recent years, intraductal papillary neoplasm of the bile ducts (IPN-B), which is analogous to intraductal papillary mucinous neoplasm of the pancreas, has been recognized as a distinct pathologic entity and a precursor lesion to adenocarcinoma of the bile ducts. Intraductal tubulopapillary neoplasm (ITPN) of the bile duct was subsequently described as a distinct pathologic entity. With increased awareness and advances in imaging techniques, these lesions are diagnosed with increased frequency at preoperative imaging. A similar neoplasm in the gallbladder is referred to as intracholecystic papillary neoplasm. These lesions are often diagnosed at a preinvasive stage and have a better prognosis than invasive cholangiocarcinoma when treated with curative resection, underscoring the importance of an accurate imaging diagnosis. The most common causes of polypoid lesions of the gallbladder are cholesterol polyps and adenomyomatosis. These lesions need to be differentiated from the less common but clinically important adenocarcinoma of the gallbladder. Imaging is crucial to identify polyps that are at high risk for malignancy so that the appropriate management choice between imaging follow-up and cholecystectomy can be made by the treating physicians. Other less common gallbladder tumors, such as gallbladder adenomas, lymphoma, and metastases to the gallbladder, can manifest as intraluminal tumors; and awareness of these lesions is also important. In this article, the recent literature is reviewed; and the imaging appearances, histopathologic findings, and management of uncommon intraluminal tumors of the bile ducts and gallbladder and their mimics are discussed. ^©RSNA, 2019.

Value of contrast-enhanced ultrasound in the differential diagnosis of gallbladder lesion

AIM

To describe contrast-enhanced ultrasound (CEUS) features and evaluate differential diagnosis value of CEUS and conventional ultrasound for patients with benign and malignant gallbladder lesions.

METHODS

This study included 105 gallbladder lesions. Before surgical resection and pathological examination, conventional ultrasound and CEUS were performed to examine for lesions. Then, all the lesions were diagnosed as (1) benign, (2) probably benign, (3) probably malignant or (4) malignant using both conventional ultrasound and CEUS. The CEUS features of these gallbladder lesions were analyzed and diagnostic efficiency between conventional ultrasound and CEUS was compared.

RESULTS

There were total 17 cases of gallbladder cancer and 88 cases of benign lesion. Some gallbladder lesions had typical characteristics on CEUS (e.g., gallbladder adenomyomatosis had typical characteristics of small nonenhanced areas on CEUS). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CEUS were 94.1%, 95.5%, 80.0%, 98.8% and 95.2%, respectively. These were significantly higher than conventional ultrasound (82.4%, 89.8%, 60.9%, 96.3% and 88.6%, respectively). CEUS had an accuracy of 100% for gallbladder sludge and CEUS helped in differential diagnosis among gallbladder polyps, gallbladder adenoma and gallbladder cancer.

CONCLUSION

CEUS may provide more useful information and improve the diagnosis efficiency for the diagnosis of gallbladder lesions than conventional ultrasound.

Diagnostic accuracy of transabdominal high-resolution US for staging gallbladder cancer and differential diagnosis of neoplastic polyps compared with EUS

PURPOSE

To compare the diagnostic accuracy of transabdominal high-resolution ultrasound (HRUS) for staging gallbladder cancer and differential diagnosis of neoplastic polyps compared with endoscopic ultrasound (EUS) and pathology.

MATERIALS AND METHODS

Among 125 patients who underwent both HRUS and EUS, we included 29 pathologically proven cancers (T1 = 7, T2 = 19, T3 = 3) including 15 polypoid cancers and 50 surgically proven polyps (neoplastic = 30, non-neoplastic = 20). We reviewed formal reports and assessed the accuracy of HRUS and EUS for diagnosing cancer as well as the differential diagnosis of neoplastic polyps. Statistical analyses were performed using chi-square tests.

RESULTS

The sensitivity, specificity, PPV, and NPV for gallbladder cancer were 82.7 %, 44.4 %, 82.7 %, and 44 % using HRUS and 86.2 %, 22.2 %, 78.1 %, and 33.3 % using EUS. HRUS and EUS correctly diagnosed the stage in 13 and 12 patients. The sensitivity, specificity, PPV, and NPV for neoplastic polyps were 80 %, 80 %, 86 %, and 73 % using HRUS and 73 %, 85 %, 88 %, and 69 % using EUS. Single polyps (8/20 vs. 21/30), larger (1.0 ± 0.28 cm vs. 1.9 ± 0.85 cm) polyps, and older age (52.5 ± 13.2 vs. 66.1 ± 10.3 years) were common in neoplastic polyps (p < 0.05).

CONCLUSION

Transabdominal HRUS showed comparable accuracy for diagnosing gallbladder cancer and differentiating neoplastic polyps compared with EUS. HRUS is also easy to use during our routine ultrasound examinations.

KEY POINTS

• HRUS showed comparable diagnostic accuracy for GB cancer compared with EUS. • HRUS and EUS showed similar diagnostic accuracy for differentiating neoplastic polyps. • Single, larger polyps and older age were common in neoplastic polyps. • HRUS is less invasive compared with EUS.

High-resolution sonography for distinguishing neoplastic gallbladder polyps and staging gallbladder cancer

OBJECTIVE. The purposes of this study were to compare staging accuracy of high-resolution sonography (HRUS) with combined low- and high-MHz transducers with that of conventional sonography for gallbladder cancer and to investigate the differences in the imaging findings of neoplastic and nonneoplastic gallbladder polyps. MATERIALS AND METHODS. Our study included 37 surgically proven gallbladder cancer (T1a = 7, T1b = 2, T2 = 22, T3 = 6), including 15 malignant neoplastic polyps and 73 surgically proven polyps (neoplastic = 31, nonneoplastic = 42) that underwent HRUS and conventional transabdominal sonography. Two radiologists assessed T-category and predefined polyp findings on HRUS and conventional transabdominal sonography. Statistical analyses were performed using chi-square and McNemar tests. RESULTS. The diagnostic accuracy for the T category was T1a = 92-95%, T1b = 89-95%, T2 = 78-86%, and T3 = 84-89%, all with good agreement (κ = 0.642) using HRUS. The diagnostic accuracy for differentiating T1 from T2 or greater than T2 was 92% and 89% on HRUS and 65% and 70% with conventional transabdominal sonography. Statistically common findings for neoplastic polyps included size greater than 1 cm, single lobular surface, vascular core, hypoechoic polyp, and hypoechoic foci (p < 0.05). The value of HRUS in the differential diagnosis of a gallbladder polyp was more clearly depicted internal echo foci than conventional transabdominal sonography (39 vs 21). A polyp size greater than 1 cm was independently associated with a neoplastic polyp (odds ratio = 7.5, p = 0.02). The AUC of a polyp size greater than 1 cm was 0.877. The sensitivity and specificity were 66.67% and 89.13%, respectively. CONCLUSION. HRUS is a simple method that enables accurate T categorization of gallbladder carcinoma. It provides high-resolution images of gallbladder polyps and may have a role in stratifying the risk for malignancy.

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.

MR cholangiopancreatography of the pancreas and biliary system: a review of the current applications

MR cholangiopancreatography (MRCP) is still a rapidly evolving technique, but it has been already accepted as clinically useful and is widely used to evaluate biliary or pancreatic diseases. The advantages of this technique are that it does not use contrast media or ionizing radiation, it is noninvasive and complication free, and the examination is relatively short. MRCP has high sensitivity and specificity for diagnosing biliary dilatation and for determining the site and cause of stenosis. With further improvements of hardware and technique, MRCP is expected to replace diagnostic endoscopic retrograde cholangiopancreatography to examine the biliary and pancreatic ducts in the near future. The other applications include evaluation of primary sclerosing cholangitis, stenosis after liver transplantation, and bilioenteric anastomoses. This article reviews the current applications of MRCP in the evaluation of the pancreas and the biliary system.

My patient has got abdominal pain: identifying biliary problems

Right upper quadrant and epigastric abdominal pain are common presenting complaints in the emergency department. With increasing access to point-of-care ultrasound, emergency physicians now have an added tool to help identify biliary problems as a cause of a patient's right upper quadrant pain. Point-of-care ultrasound has a sensitivity of 89.8% (95% CI 86.4-92.5%) and specificity of 88.0% (83.7-91.4%) for cholelithiasis, very similar to radiology-performed ultrasonography. In addition to assessment for cholelithiasis and cholecystitis, point-of-care ultrasound can help emergency physicians to determine whether the biliary system is the source of infection in patients with suspected sepsis. Use of point-of-care ultrasound for the assessment of the biliary system has resulted in more rapid diagnosis, decreasing costs, and shorter emergency department length of stay.

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.

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.

Acute cholecystitis: quantitative and qualitative evaluation with 64-section helical CT

BACKGROUND

Because of an expanded role for CT in the evaluation of patients with acute abdominal pain, it is not rare that acute cholecystitis is depicted by CT. However, the sensitivity and the specificity of a given CT variable for the diagnosis of acute cholecystitis is not known.

PURPOSE

To quantitatively and qualitatively analyze acute cholecystitis at 64-section helical CT with submilimeter and isotropic voxels using a retrospective case-control study.

MATERIAL AND METHODS

The 64-section helical CT examinations obtained with submilimeter and isotropic voxels in 40 patients with acute cholecystitis (25 men; mean age, 62.2 years) were quantitatively and qualitatively analyzed and compared to those of 40 control subjects matched for age and gender. Receiver-operating characteristic (ROC) curve analysis was used to determine the most discriminating cut-off values for quantitative variables. Comparisons of qualitative variables were made using univariate analysis.

RESULTS

Pericholecystic fat stranding, mural stratification, pericholecystic hypervascularity, spontaneous hyperattenuation of gallbladder wall, short (≥ 32-mm) and long (≥ 74-mm) gallbladder axis enlargement, and gallbladder wall thickening (≥ 3.6-mm) were the most discriminating and independent variables for the diagnosis of acute cholecystitis (P < 0.0001). Using cut-off values found at ROC curve analysis, gallbladder wall thickening, and short and long gallbladder axis enlargement were the most sensitive findings (sensitivity = 92.5%; 95%CI: 79.6%-98.4%) for the diagnosis of acute cholecystitis.

CONCLUSION

Acute cholecystitis is associated with myriad suggestive findings on 64-section helical CT. It can be anticipated that familiarity with these findings would result in more confident diagnosis of acute cholecystitis at 64-section helical CT.

A prospective, blinded comparison of laparoscopic ultrasound with transabdominal ultrasound for the detection of gallbladder pathology in morbidly obese patients

BACKGROUND

Transabdominal ultrasound (TAU) is the gold standard for detecting cholelithiasis. Morbid obesity can inhibit detection of gallbladder pathology due to increased subcutaneous and visceral fat. Laparoscopic ultrasound (LUS) has the potential to overcome these technical challenges. We hypothesized that LUS would have a sensitivity and specificity similar to TAU for detecting cholelithiasis and polyps in morbidly obese patients presenting for laparoscopic Roux-en-Y gastric bypass.

STUDY DESIGN

After Institutional Review Board approval, patients underwent preoperative TAU and intraoperative LUS during laparoscopic Roux-en-Y gastric bypass. Certified ultrasonographers performed all TAUs. Surgeons, blinded to TAU results, performed the LUS. Presence of cholelithiasis or polyps and common bile duct diameter was evaluated. Statistical analysis included chi-square and McNemar's test.

RESULTS

Two hundred and fifty-three patients were prospectively enrolled during a 6-year period. Seventy-six percent were female, mean age and preoperative body mass index (calculated as kg/m(2)) were 43.5 years and 48, respectively. Mean time to complete the LUS was 4 minutes. Mean common bile duct diameter measured 3.7 mm via LUS and 4.0 mm via TAU. Transabdominal ultrasound and LUS identified 61 and 60 patients with cholelithiasis, respectively (p = 0.763). The sensitivity and specificity of LUS for cholelithiasis was 90.2% and 97.4%. Laparoscopic ultrasound identified polyps in 41 patients, and TAU identified polyps in 6 patients, 5 of which had polyps identified on LUS as well (p < 0.001). Sensitivity and specificity of LUS for polyps was 83.3% and 85.4%.

CONCLUSIONS

Laparoscopic ultrasound is equivalent to TAU in detecting cholelithiasis, however, LUS detected significantly more polyps. Intraoperative LUS is an appropriate alternative to TAU in patients undergoing laparoscopic Roux-en-Y gastric bypass.

Pre-ERCP imaging of the bile duct and gallbladder

Advances in biliary imaging have improved making accurate diagnoses of the presence and causes of biliary obstruction. Abdominal ultrasound is a useful screening tool because it is highly specific for choledocholithiasis. New developments in CT and MRI have also been useful in the diagnosis of biliary disease. Although diagnosis of biliary disease can be achieved in a noninvasive manner, there are limitations to modern MRI and CT cholangiographic techniques; their use may not be necessary or cost effective. MRI and CT imaging of the biliary tract provides opportunities for less-invasive diagnostic techniques but should be used judiciously before interventional endoscopy.

Errors and mistakes in the ultrasound diagnostics of the liver, gallbladder and bile ducts

Ultrasonography is the most widespread imaging technique used in the diagnostics of the pathologies concerning the organs in the abdominal cavity. Similarly to other diagnostic tools, errors may occur in ultrasound examinations. They generally result from inappropriate techniques, which do not conform to current standards, or erroneous interpretation of obtained images. A significant portion of mistakes is caused by inappropriate quality of the apparatus, the presence of sonographic imaging artifacts, unfavorable anatomic variants or improper preparation of the patient for the examination. This article focuses on the examiner-related errors. They concern the evaluation of the liver size, echostructure and arterial and venous vascularization as well as inappropriate interpretation of the liver anatomic variants and the vascular and ductal structures localized inside of it. Furthermore, the article presents typical mistakes made during the diagnosis of the most common gallbladder and bile duct diseases. It also includes helpful data concerning differential diagnostics of the described pathologies of the liver, gallbladder and bile ducts. The article indicates the most frequent sources of mistakes as well as false negative and false positive examples which result from these errors. What is more, the norms used in the liver, gallbladder and bile duct evaluations are presented as well as some helpful guidelines referring to the exam techniques and image interpretation, which allows for reducing the error-making risk. The article has been prepared on the basis of the report published in 2005 by the Polish experts in the field of ultrasonography and extended with the latest findings obtained from the pertinent literature.

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.

Non-operative management of acute cholecystitis in the elderly

BACKGROUND

Although cholecystectomy is the standard therapy for acute cholecystitis (AC), operative morbidity in the elderly may be high owing to medical co-morbidities and decreased physiological reserve. Outcomes of AC in the elderly have not been fully defined with regard to operative and long-term non-operative management.

METHODS

Patients aged 65 years or over admitted to a tertiary care centre with a diagnosis of AC between January 2000 and December 2009 were reviewed retrospectively. Patient data, operative and postoperative details were obtained. To determine cholecystectomy rates in the non-operative group, medical records were reviewed, and patients and families were interviewed.

RESULTS

A total of 290 patients underwent cholecystectomy during the index admission, of whom 59 (20·3 per cent) required conversion to open operation. Fifty-eight of these patients experienced 98 complications, including acute respiratory failure (27), pneumonia (18), myocardial infarction (16) and sepsis (15). Some 185 patients had non-operative treatment, of whom 67 underwent percutaneous cholecystostomy. Forty-four patients subsequently had elective cholecystectomy, with a complication rate of 23 per cent. One hundred and twenty-six patients were discharged without a plan for cholecystectomy; the rate of recurrent AC was 4 per cent among the two-thirds of patients followed to within 15 months of death. No deaths or major complications occurred among those with recurrent AC.

CONCLUSION

Despite selection of the best elderly candidates for cholecystectomy, postoperative morbidity was significant. Medical management, with interval cholecystectomy only for recurrent AC, may be appropriate in selected patients.

Intramural gallbladder hematoma mimicking gallbladder neoplasm in a 55-year-old male patient

Hemorrhage in the gallbladder (GB) is usually associated with cholecystitis, GB neoplasm, trauma, hemobilia, and cystic artery aneurysm. Our patient had not experienced any previous abdominal trauma, and GB hemorrhage was unlikely to result from cholecystitis or bleeding diathesis. A 55-year-old male was admitted because of right upper quadrant pain. Both prothrombin time and partial thromboplastin time were normal. Abdominal computed tomography, endoscopic ultrasound and magnetic resonance cholangiopancreatography were performed. Image studies revealed GB wall thickening and an intraluminal mass. Laparoscopic cholecystectomy was performed. Upon opening the GB postoperatively, a large amount of fresh blood and old blood clot was noted. The incidence of GB hematoma is very rare. GB hematoma should always be considered in the differential diagnosis of GB tumor. In such a situation, surgical intervention is needed for further patient evaluation and management. We present a rare case of intramural GB hematoma, of which we were unable to make a definitive diagnosis preoperatively.

Current imaging strategies of primary and secondary neoplasms of the liver

This article details the diagnosis and imaging of primary and secondary neoplasms of the liver. Benign conditions that can mimic malignancy are also discussed, such as focal nodular hyperplasia and adenoma. Considerable attention is given to hepatoma, which is the most common primary hepatic tumor in the United States. The roles of magnetic resonance imaging, computed tomography, and ultrasound are evaluated, with recommendations for their effective use. Pitfalls in imaging related to posttreatment changes and unusual patterns of metastatic disease are illustrated.

Biliary, pancreatic, and hepatic imaging for the general surgeon

Technologic advancements have allowed imaging modalities to become more useful in the diagnosis of hepatobiliary and pancreatic disorders. Computed tomography scanners now use multidetector row technology with contrast-delayed imaging for quicker and more accurate imaging. Magnetic resonance imaging with cholangiopancreatography can more clearly delineate liver lesions and the biliary and pancreatic ducts, and can diagnose pathologic conditions early in their course. Newer technologies, such as single-operator cholangioscopy and endoscopic ultrasonography, have sometimes shown superiority to traditional modalities. This article addresses the literature regarding available imaging techniques in the diagnosis and treatment of common surgical hepatobiliary and pancreatic diseases.

Evaluation of gallbladder and biliary duct disease using microbubble contrast-enhanced ultrasound

Ultrasound examination of the gallbladder is accepted as the primary imaging modality in the assessment of gallbladder disease, with inherent superiority in comparison to other imaging modalities. Contrast-enhanced ultrasound is established as a reliable tool in the detection and characterisation of focal liver lesions. It is less well recognised in gallbladder and biliary disease but can be a valuable complement to baseline ultrasound examination. Contrast-enhanced ultrasound provides the advantages of real-time, repeatable, multiplanar imaging without compromising patient safety or exposing patients to radiation. It can provide specific information as pathology often becomes more conspicuous following the administration of contrast, allowing detailed assessment of benign and malignant conditions arising in the gallbladder and biliary tree. This review illustrates the application of contrast-enhanced ultrasound in the evaluation of a variety of gallbladder and biliary duct diseases. The examination allows clearer delineation of the disease process and more confident diagnosis.

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.

Intraluminal versus infiltrating gallbladder carcinoma: Clinical presentation, ultrasound and computed tomography

AIM: To compare clinical presentation and ultrasound (US) and computed tomography (CT) sensitivity between intraluminal and infiltrating gallbladder carcinoma (GBCA).

METHODS: This retrospective study evaluated 65 cases of GBCA that were categorized morphologically into the intraluminal-GBCA (n = 37) and infiltrating-GBCA (n = 28) groups. The clinical and laboratory findings, presence of gallstones, gallbladder size, T-staging, nodal status, sensitivity of preoperative US and CT studies, and outcome were compared between the two groups.

RESULTS: There were no significant differences between the two groups with respect to female predominance, presence of abdominal pain, serum aminotransferases level, T2-T4 staging, and regional metastatic nodes. Compared with the patients with intraluminal-GBCA, those with infiltrating-GBCA were significantly older (65.49 ± 1.51 years vs 73.07 ± 1.90 years), had a higher frequency of jaundice (3/37 patients vs 13/28 patients) and fever (3/37 patients vs 10/28 patients), higher alkaline phosphatase (119.36 ± 87.80 IU/L vs 220.68 ± 164.84 IU/L) and total bilirubin (1.74 ± 2.87 mg/L vs 3.50 ± 3.51 mg/L) levels, higher frequency of gallstones (12/37 patients vs 22/28 patients), smaller gallbladder size (length, 7.47 ± 1.70 cm vs 6.47 ± 1.83 cm; width, 4.21 ± 1.43 cm vs 2.67 ± 0.93 cm), and greater proportion of patients with < 12 mo survival (16/37 patients vs 18/28 patients). The sensitivity for diagnosing intraluminal-GBCA with and without gallstones was 63.6% and 91.3% by US, and 80% and 100% by CT, respectively. The sensitivity for diagnosing infiltrating-GBCA with and without gallstones was 12.5% and 25% by US, and 71.4% and 75% by CT, respectively.

CONCLUSION: In elderly women exhibiting small gallbladder and gallstones on US, especially those with jaundice, fever, high alkaline phosphatase and bilirubin levels, CT may reveal concurrent infiltrating-GBCA.

Gallbladder carcinoma manifesting as acute cholecystitis: clinical and computed tomographic features

BACKGROUND

Gallbladder carcinoma is uncommon and may manifest as acute cholecystitis. An accurate diagnosis is helpful for operative planning and this study attempted to explore the distinctive clinical and computed tomographic (CT) features for differentiating acute cholecystitis alone from that with contemporaneous gallbladder carcinoma.

METHODS

This 20-year, retrospective study evaluated the CT features of 26 patients with surgically proven gallbladder carcinoma with clinical presentations of acute cholecystitis (carcinoma group). Thirty elderly patients with surgically proven simple acute cholecystitis were enrolled as age-matched controls (cholecystitis group). The clinical, laboratory, and CT findings were compared between the 2 groups.

RESULTS

The carcinoma and cholecystitis groups showed no significant differences with respect to clinical symptoms (abdominal pain, fever, and jaundice), serum total bilirubin level, leukocyte count, percentage of segmented leukocytes, presence of gallstones, and CT features of pericholecystic stranding/fluid and focally increased enhancement of adjacent liver. Fifteen of the 26 (57.6%) patients in the carcinoma group exhibited diffuse gallbladder wall thickening on CT and the other 11 exhibited focal thickening or intraluminal masses. Beside female predominance, the patients in the carcinoma group had significantly higher serum aspartate/alanine aminotransferase and alkaline phosphatase levels, a thicker gallbladder wall, smaller volume, lower frequency of triple-layer gallbladder wall enhancement pattern, and a higher frequency of enlarged regional lymph nodes than those in the cholecystitis group.

CONCLUSION

For elderly patients, especially women, presenting with acute cholecystitis and abnormal liver function, CT demonstration of focal gallbladder wall thickening, intraluminal masses, small gallbladder with diffuse wall thickening, and enlarged regional lymph nodes are suggestive of concurrent gallbladder carcinoma. Triple-layer gallbladder wall enhancement is suggestive of simple acute cholecystitis.

High b-value diffusion-weighted MRI for detecting gallbladder carcinoma: preliminary study and results

The aim of this preliminary study was to retrospectively evaluate the usefulness of high b-value diffusion-weighted MR imaging (DWI) in the detection of gallbladder carcinoma. Fifteen patients with gallbladder carcinoma and 14 other patients were included in this study. All patients and subjects underwent DWI, and images were evaluated by two radiologists. The area under the receiver operating characteristic curve (AUC), apparent diffusion coefficient (ADC) measurement, sensitivity and specificity were calculated. An AUC yielded 0.980 (95% CI, 0.850-0.999) and 0.941 (95% CI, 0.791-0.990) for the two radiologists. The mean sensitivity and specificity were 83.3% and 100%, respectively. The mean ADC value of gallbladder carcinoma was (1.28 +/- 0.41)x10(-3) mm(2)/s and that of control gallbladder lesions was (1.92 +/- 0.21)x10(-3) mm(2)/s (P < 0.01). According to the results of our preliminary study, high b-value DWI might be a useful tool for detecting gallbladder carcinoma by measuring the ADC value and direct visual assessment.