Management and follow-up of gallbladder polyps: updated joint guidelines between the ESGAR, EAES, EFISDS and ESGE.

MAIN RECOMMENDATIONS: 1. Primary investigation of polypoid lesions of the gallbladder should be with abdominal ultrasound. Routine use of other imaging modalities is not recommended presently, but further research is needed. In centres with appropriate expertise and resources, alternative imaging modalities (such as contrast-enhanced and endoscopic ultrasound) may be useful to aid decision-making in difficult cases. Strong recommendation, low-moderate quality evidence. 2. Cholecystectomy is recommended in patients with polypoid lesions of the gallbladder measuring 10 mm or more, providing the patient is fit for, and accepts, surgery. Multidisciplinary discussion may be employed to assess perceived individual risk of malignancy. Strong recommendation, low-quality evidence. 3. Cholecystectomy is suggested for patients with a polypoid lesion and symptoms potentially attributable to the gallbladder if no alternative cause for the patient's symptoms is demonstrated and the patient is fit for, and accepts, surgery. The patient should be counselled regarding the benefit of cholecystectomy versus the risk of persistent symptoms. Strong recommendation, low-quality evidence. 4. If the patient has a 6-9 mm polypoid lesion of the gallbladder and one or more risk factors for malignancy, cholecystectomy is recommended if the patient is fit for, and accepts, surgery. These risk factors are as follows: age more than 60 years, history of primary sclerosing cholangitis (PSC), Asian ethnicity, sessile polypoid lesion (including focal gallbladder wall thickening > 4 mm). Strong recommendation, low-moderate quality evidence. 5. If the patient has either no risk factors for malignancy and a gallbladder polypoid lesion of 6-9 mm, or risk factors for malignancy and a gallbladder polypoid lesion 5 mm or less, follow-up ultrasound of the gallbladder is recommended at 6 months, 1 year and 2 years. Follow-up should be discontinued after 2 years in the absence of growth. Moderate strength recommendation, moderate-quality evidence. 6. If the patient has no risk factors for malignancy, and a gallbladder polypoid lesion of 5 mm or less, follow-up is not required. Strong recommendation, moderate-quality evidence. 7. If during follow-up the gallbladder polypoid lesion grows to 10 mm, then cholecystectomy is advised. If the polypoid lesion grows by 2 mm or more within the 2-year follow-up period, then the current size of the polypoid lesion should be considered along with patient risk factors. Multidisciplinary discussion may be employed to decide whether continuation of monitoring, or cholecystectomy, is necessary. Moderate strength recommendation, moderate-quality evidence. 8. If during follow-up the gallbladder polypoid lesion disappears, then monitoring can be discontinued. Strong recommendation, moderate-quality evidence. SOURCE AND SCOPE: These guidelines are an update of the 2017 recommendations developed between the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), European Association for Endoscopic Surgery and other Interventional Techniques (EAES), International Society of Digestive Surgery-European Federation (EFISDS) and European Society of Gastrointestinal Endoscopy (ESGE). A targeted literature search was performed to discover recent evidence concerning the management and follow-up of gallbladder polyps. The changes within these updated guidelines were formulated after consideration of the latest evidence by a group of international experts. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. KEY POINT: • These recommendations update the 2017 European guidelines regarding the management and follow-up of gallbladder polyps.

Management and follow-up of gallbladder polyps : Joint guidelines between the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), European Association for Endoscopic Surgery and other Interventional Techniques (EAES), International Society of Digestive Surgery - European Federation (EFISDS) and European Society of Gastrointestinal Endoscopy (ESGE).

OBJECTIVES: The management of incidentally detected gallbladder polyps on radiological examinations is contentious. The incidental radiological finding of a gallbladder polyp can therefore be problematic for the radiologist and the clinician who referred the patient for the radiological examination. To address this a joint guideline was created by the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), European Association for Endoscopic Surgery and other Interventional Techniques (EAES), International Society of Digestive Surgery - European Federation (EFISDS) and European Society of Gastrointestinal Endoscopy (ESGE). METHODS: A targeted literature search was performed and consensus guidelines were created using a series of Delphi questionnaires and a seven-point Likert scale. RESULTS: A total of three Delphi rounds were performed. Consensus regarding which patients should have cholecystectomy, which patients should have ultrasound follow-up and the nature and duration of that follow-up was established. The full recommendations as well as a summary algorithm are provided. CONCLUSIONS: These expert consensus recommendations can be used as guidance when a gallbladder polyp is encountered in clinical practice. KEY POINTS: • Management of gallbladder polyps is contentious • Cholecystectomy is recommended for gallbladder polyps >10 mm • Management of polyps <10 mm depends on patient and polyp characteristics • Further research is required to determine optimal management of gallbladder polyps.

Half-dose gadobenate dimeglumine versus standard-dose gadodiamide in dynamic magnetic resonance imaging of non-cirrhotic livers: a retrospective intra-individual crossover comparison.

PURPOSE: The purpose of this study was to compare enhancement characteristics of half-dose gadobenate dimeglumine (0.05 mmol kg(-1)) with standard-dose gadodiamide (0.10 mmol kg(-1)), in the assessment of hepatic vessels and lesions, using retrospective intra-individual crossover comparison methodology. METHODS: Ethics committee approval was obtained. From 2004 to 2012, 21 patients underwent MRI examination with both standard-dose gadodiamide and half-dose gadobenate dimeglumine, using the same liver MRI protocol at 1.5 T. Eighteen patients whose scans showed no artifacts were selected. Quality of liver lesion [12 hemangiomas, 7 focal nodular hyperplasias (FNHs)] and liver vessel enhancement, and the global diagnostic quality of studies were ranked on a scale of 1-4 by two independent radiologists. Contrast-to-noise ratio (CNR) and % enhancement of liver vessels and lesions were calculated based on region of interest, signal intensity, and noise standard deviation measurements performed at 0, 20 s, 1, 3, and 5 min post-contrast injection. Qualitative and quantitative results were compared using the paired Wilcoxon signed rank and Student's t-tests, respectively. RESULTS: No qualitative differences were noted in enhancement of liver vessels, hemangiomas, and FNHs. There was no statistically significant difference between the global diagnostic qualities of scans performed with the two contrast agents. Quantitatively, liver vessels and hemangiomas did not demonstrate statistically significant differences in contrast enhancement. At 20 s, FNHs achieved higher CNR (P = 0.02) with gadodiamide. CONCLUSION: Half-dose gadobenate dimeglumine results in similar contrast enhancement compared to standard-dose gadodiamide in assessment of liver vessels, hemangiomas, and FNHs, and is a reasonable alternative to standard doses of extracellular agents in dynamic liver MRI.

The revised Atlanta classification of acute pancreatitis: its importance for the radiologist and its effect on treatment.

An international working group has modified the Atlanta classification for acute pancreatitis to update the terminology and provide simple functional clinical and morphologic classifications. The modifications (a) address the clinical course and severity of disease, (b) divide acute pancreatitis into interstitial edematous pancreatitis and necrotizing pancreatitis, (c) distinguish an early phase (1st week) and a late phase (after the 1st week), and (d) emphasize systemic inflammatory response syndrome and multisystem organ failure. In the 1st week, only clinical parameters are important for treatment planning. After the 1st week, morphologic criteria defined on the basis of computed tomographic findings are combined with clinical parameters to help determine care. This revised classification introduces new terminology for pancreatic fluid collections. Depending on presence or absence of necrosis, acute collections in the first 4 weeks are called acute necrotic collections or acute peripancreatic fluid collections. Once an enhancing capsule develops, persistent acute peripancreatic fluid collections are referred to as pseudocysts; and acute necrotic collections, as walled-off necroses. All can be sterile or infected. Terms such as pancreatic abscess and intrapancreatic pseudocyst have been abandoned. The goal is for radiologists, gastroenterologists, surgeons, and pathologists to use the revised classifications to standardize imaging terminology to facilitate treatment planning and enable precise comparison of results among different departments and institutions.

Effect of T1 shortening on T2-weighted MRI sequences: comparison of hepatic mass conspicuity on images acquired before and after gadolinium enhancement.

OBJECTIVE: The purpose of this study was to compare the conspicuity of hepatic lesions on T2-weighted fast-recovery fast spin-echo MR images obtained before and after administration of gadolinium. MATERIALS AND METHODS: We reviewed T2-weighted fast-recovery fast spin-echo images before and after gadolinium enhancement for 84 patients with 118 focal liver lesions. Solid lesions (22 hepatomas, seven ablated hepatomas, 12 metastatic lesions, six cases of focal nodular hyperplasia, five dysplastic nodules, one adenoma) were proved pathologically or with multiple follow-up studies. Nonsolid lesions were diagnosed as hemangiomas (n = 33) or cysts (n = 32) on the basis of imaging features. Two blinded radiologists interpreted the images independently, reading unenhanced images first and gadolinium-enhanced images at least 2 weeks later. Lesion conspicuity was ranked as follows: 1, poor; 2, moderate; 3, good; 4, excellent. The sign test was used for qualitative scoring of imaging pairs (unenhanced and gadolinium enhanced). The Fisher's exact test was used for subgroup analysis of solid and nonsolid lesions. RESULTS: On gadolinium-enhanced T2-weighted images, 21 (17.8%) of 118 of the lesions had improved conspicuity, 86 (72.9%) had no difference in conspicuity, and 11 (9.3%) appeared worse. No statistically significant difference was found between unenhanced and enhanced images (p = 0.11), but a trend toward improved conspicuity with gadolinium enhancement was observed. Subgroup analysis showed that on gadolinium-enhanced T2-weighted images, visualization of solid hepatic lesions (28.3%) was significantly better than that of nonsolid lesions (9.2%) (p = 0.01). CONCLUSION: Compared with unenhanced T2-weighted images, gadolinium-enhanced T2-weighted images had a trend toward improved conspicuity of focal liver lesions. Subgroup analysis showed that visualization of solid lesions benefited significantly more from use of gadolinium-enhanced T2-weighted sequences than did visualization of nonsolid lesions.

Can tumor coverage evaluated 24 h post-radiofrequency ablation predict local tumor progression of liver metastases?

PURPOSE: To assess the predictive value for local tumor progression (LTP) of geometrical tumor coverage using the contrast-enhanced (ce-)CT images acquired before and within 24 h after radiofrequency (RF) ablation. METHODS: Twenty patients (6 male and 14 female, median age 62 years) with 45 focal hypovascular liver metastases (16 colorectal carcinoma, 3 melanoma and 1 breast carcinoma) underwent RF ablation under CT-guidance and received a ce-PET/CT scan within 24 h post-procedure. Pre- and post-ablation ce-CT-images were aligned using an interactive procedure and used to verify the tumor coverage of the RF ablation. Results were correlated to LTP as recorded during follow-up performed every 2-3 months after the intervention (mean follow-up of 110 weeks) and compared to standard reading performed by three readers of the ce-CT images. RESULTS: Eleven tumors (25%) showed LTP during the follow-up period. One lesion, which did not show LTP, was excluded from analysis due to the poor quality of the alignment. For the remaining, 29 (66%) tumors were completely covered by the ablation zone, 9 (20%) were not, and for 6 (14%) tumors the edges coincided with the edge of the ablation zone. The sensitivity, specificity, PPV and NPV for LTP of having incomplete tumor coverage or no apparent ablative margin versus standard reading of ce-CT were 100, 88, 73 and 100% versus 42, 88, 58 and 82%, respectively. CONCLUSIONS: Verifying the tumor coverage of liver metastases by an ablation zone through alignment of pre- and early post-ablation ce-CT images has a high predictive value for LTP.

Current concepts in imaging of appendicitis.

Appendicitis is the most common cause of acute abdominal pain requiring surgery. Early diagnosis is crucial to the success of therapy. CT and ultrasound are widely recognized as very useful in the timely diagnosis of appendicitis. MR imaging is emerging as an alternative to CT in pregnant patients and in patients who have an allergy to iodinated contrast material. This article reviews the current imaging methods and diagnostic features of appendicitis.

Early nonenhanced abdominal computed tomography can predict mortality in severe acute pancreatitis.

We wondered whether nonenhanced computed tomography (CT) within 48 hours of admission could identify individuals at risk for higher mortality from acute pancreatitis. Data from the international phase III study of the platelet-activating factor-inhibitor Lexipafant was used to analyze noncontrast CT versus acute pancreatitis mortality. Nonenhanced CT examinations of the abdomen from the trial were classified by disease severity (Balthazar grades A-E) and then correlated with patient survival. Among the 477 individuals who underwent CT within 48 hours of admission and 220 individuals who did so over the subsequent 6 days, higher CT grades were associated with increased mortality. Each unit increase in Balthazar grade during the initial 48 hours was associated with an estimated increase in the risk of mortality of 33%, and this trend increased to 50% if pancreatic enlargement and peripancreatic stranding (grades B and C) were combined (P<0.05). CT grade correlated minimally with Ranson, Glasgow, or APACHE II score during the initial 48 hours; however, this correlation improved over 3-8 days. Early nonenhanced abdominal CT in patients with acute pancreatitis is a valuable prognostic indicator of mortality in acute pancreatitis, even among patients without clinical features of severe acute pancreatitis.

Imaging of Acute Pancreatitis.

Acute pancreatitis is an acute inflammation of the pancreas. Several classification systems have been used in the past but were considered unsatisfactory. A revised Atlanta classification of acute pancreatitis was published that assessed the clinical course and severity of disease; divided acute pancreatitis into interstitial edematous pancreatitis and necrotizing pancreatitis; discerned an early phase (first week) from a late phase (after the first week); and focused on systemic inflammatory response syndrome and organ failure. This article focuses on the revised classification of acute pancreatitis, with emphasis on imaging features, particularly on newly-termed fluid collections and implications for the radiologist.

Case 117: actinomycosis of left kidney with sinus tracts.

A 39-year-old Samoan man presented to the emergency department with fever, progressive weakness, and left flank pain of 1-month duration. For several months, he had also experienced progressive weight loss. There was no history of recent trauma, and he was not taking any medication. His medical history was notable for a large left groin abscess and left lower lobe pneumonia of unknown cause 1 year prior to the current admission. Furthermore, he had undergone exploratory laparotomy and gastric surgery for peptic ulcer disease approximately 10 years ago. Physical examination findings were positive for a tender firm mass in the left flank with no associated skin changes. Laboratory findings revealed an elevated white blood cell count of 18 x 10(9)/L. The urine cultures were negative. A computed tomographic (CT) image obtained 1 year prior to the current admission was unremarkable. CT of the abdomen and pelvis (section thickness, 5 mm) was performed after ingestion of 900 mL of 2% diatrizoate meglumine and diatrizoate sodium (Gastrografin; Bracco Diagnostics, Princeton, NJ). A 150-mL dose of iohexol (300 mg of iodine per milliliter) (Omnipaque; Nycomed, New York, NY) was administered intravenously at a rate of 4 mL/sec with a 70-second scan delay. Unenhanced CT images (not shown) did not reveal any areas of high attenuation.

CT imaging of colitis.

Computed tomography (CT) is widely used to assess patients with nonspecific abdominal pain or who are suspected of having colitis. The authors recommend multidetector CT with oral, rectal, and intravenous contrast material and thin sections, which can accurately demonstrate inflammatory changes in the colonic wall and help assess the extent of disease. In most cases, the final diagnosis of the type of colitis is based on clinical and laboratory data and colonoscopic and biopsy findings, but specific CT features help narrow the differential diagnosis. Ulcerative colitis is distinguished from granulomatous colitis (Crohn disease) in terms of location of involvement, extent and appearance of colonic wall thickening, and type of complications. Ulcerative colitis and Crohn disease (granulomatous colitis) are rarely associated with ascites, which is often seen in infectious, ischemic, and pseudomembranous colitis. Pseudomembranous colitis also demonstrates marked wall thickening and, occasionally, skip areas but is associated with broad-spectrum antibiotic treatment or chemotherapy. Neutropenic colitis is characterized by right-sided colonic and ileal involvement, whereas ischemic colitis is characterized by vascular distribution pattern and history. Diverticulitis is a focal asymmetric process with fascial thickening and inflamed diverticula. Dilatation of a thick-walled appendix with increased enhancement and adjacent stranding suggests appendicitis, but inflammatory changes may extend to the cecum and terminal ileum. Epiploic appendagitis is a focal rim-enhancing area next to the colon, usually without any substantial colonic wall thickening.

Detection of hepatocellular carcinoma by ferumoxides-enhanced MR imaging in cirrhosis: Incremental value of dynamic gadolinium-enhancement.

PURPOSE: To investigate the incremental value of dynamic gadolinium-enhancement performed immediately after ferumoxides-enhanced magnetic resonance (MR) imaging on the detection of hepatocellular carcinoma in patients with cirrhosis. MATERIALS AND METHODS: We retrospectively reviewed MR scans of 62 cirrhotic patients over a two-year period. Sequences included ferumoxides-enhanced T2-weighted fast spin echo followed by dynamic gadolinium-enhanced T1-weighted spoiled gradient echo. Two readers independently documented the presence of hepatocellular carcinoma on a three-point confidence scale, without and with gadolinium-enhanced images. The presence or absence of hepatocellular carcinoma was established by histopathology (58 patients) or follow-up imaging (four patients) over a mean period of nine months. RESULTS: A total of 71 hepatocellular carcinomas were found in 42 patients. There was no statistically significant difference in sensitivity for the diagnosis of hepatocellular carcinoma without vs. with gadolinium-enhanced images (68% vs. 74% for reader 1 and 62% vs. 73% for reader 2, respectively, P > 1.3). However, both readers showed a lower mean confidence for tumor detection without vs. with gadolinium-enhanced images (2.3 vs. 2.7 for reader 1, 2.3 vs. 2.9 for reader 2, P < 0.01). CONCLUSION: In our study, the addition of dynamic gadolinium-enhancement to ferumoxides-enhanced MR imaging did not improve hepatocellular carcinoma detection, but the addition of gadolinium-enhancement is recommended if ferumoxides-enhanced imaging is used because it increased reader confidence.

Detection of hepatic metastases from cancers of the gastrointestinal tract by using noninvasive imaging methods (US, CT, MR imaging, PET): a meta-analysis.

PURPOSE: To perform a meta-analysis to compare current noninvasive imaging methods (ultrasonography [US], computed tomography [CT], magnetic resonance [MR] imaging, and (18)F fluorodeoxyglucose [FDG] positron emission tomography [PET]) in the detection of hepatic metastases from colorectal, gastric, and esophageal cancers. MATERIALS AND METHODS: A MEDLINE literature search and review of article bibliographies and our institutional charts of patients with colorectal cancer identified data with histopathologic correlation or at least 6 months of patient follow-up. Two authors independently abstracted data sets and excluded data without contingency tables or data published more than once. Summary-weighted estimates of sensitivity were obtained and stratified according to specificity of less than 85% or 85% and higher. A covariate analysis was used to evaluate the influence of patient- or study-related factors on sensitivity. RESULTS: Among 111 data sets, nine US (509 patients), 25 CT (1,747 patients), 11 MR imaging (401 patients), and nine PET (423 patients) data sets met the inclusion criteria. In studies with a specificity higher than 85%, the mean weighted sensitivity was 55% (95% CI: 41, 68) for US, 72% (95% CI: 63, 80) for CT, 76% (95% CI: 57, 91) for MR imaging, and 90% (95% CI: 80, 97) for FDG PET. Results of pairwise comparison between imaging modalities demonstrated a greater sensitivity of FDG PET than US (P =.001), CT (P =.017), and MR imaging (P =.055). CONCLUSION: At equivalent specificity, FDG PET is the most sensitive noninvasive imaging modality for the diagnosis of hepatic metastases from colorectal, gastric, and esophageal cancers.