Imaging of cholecystitis. AJR Am J Roentgenol. 2011;196:W367-W374. [PMID: 21427298 DOI: 10.2214/ajr.10.4340]

An exploration of radiological signs in post-intervention liver complications

The advent and progression of radiological techniques in the past few decades have revolutionized the diagnostic and therapeutic landscape for liver diseases. These minimally invasive interventions, ranging from biopsies to complex therapeutic procedures like transjugular intrahepatic portosystemic shunt placement and transarterial embolization, offer substantial benefits for the treatment of patients with liver diseases. They provide accurate tissue diagnosis, allow real-time visualization, and render targeted treatment for hepatic lesions with enhanced precision. Despite their advantages, these procedures are not without risks, with the potential for complications that can significantly impact patient outcomes. It is imperative for radiologists to recognize the signs of these complications promptly to mitigate further health deterioration. Ultrasound, CT, and MRI are widely utilized examinations for monitoring the complications. This article presents an overarching review of the most commonly encountered hepatobiliary complications post-radiological interventions, emphasizing their imaging characteristics to improve patient post-procedure management.

When Not to Operate on Acute Cases-A Surgeon's Perspective on Rapid Assessment of Emergency Abdominopelvic Computed Tomography

Clinical problem solving evolves in parallel with advances in technology and discoveries in the medical field. However, it always reverts to basic cognitive processes involved in critical thinking, such as hypothetical-deductive reasoning, pattern recognition, and compilation models. When dealing with cases of acute abdominal pain, clinicians should employ all available tools that allow them to rapidly refine their analysis for a definitive diagnosis. Therefore, we propose a standardized method for the quick assessment of abdominopelvic computed tomography as a supplement to the traditional clinical reasoning process. This narrative review explores the cognitive basis of errors in reading imaging. It explains the practical use of attenuation values, contrast phases, and windowing for non-radiologists and details a multistep protocol for finding radiological cues during CT reading and interpretation. This systematic approach describes the salient features and technical tools needed to ascertain the causality between clinical patterns and abdominopelvic changes visible on CT scans from a surgeon's perspective. It comprises 16 sections that should be read successively and that cover the entire abdominopelvic region. Each section details specific radiological signs and provides clear explanations for targeted searches, as well as anatomical and technical hints. Reliance on imaging in clinical problem solving does not make a decision dichotomous nor does it guarantee success in diagnostic endeavors. However, it contributes exact information for supporting the clinical assessments even in the most subtle and intricate conditions.

Effectiveness of ultrasound screening in right upper quadrant pain: A comparative study in a basic emergency service

Background and Aims

The use of ultrasound screening is primarily facilitated by point-of-care ultrasound (POCUS) and its integration into healthcare systems is a result of the versatility of this imaging technique. This study intends to compare the accuracy and pertinence of sonographic findings obtained by a sonographer in a Basic Emergency Service (BES) with that of radiologists at referral hospital (RH) in Portugal.

Methods

Twenty patients with right upper quadrant (RUQ) pain and suspected cholecystitis or biliary pathology underwent sonography screening using POCUS in the BES. They were then forwarded to the RH where a radiologist performed a conventional ultrasound exam on the same patients. The results of both exams were compared to determine if the findings obtained in the BES were confirmed by the radiologist in the RH.

Results

In our sample, 60% of cases were related to biliary pathology, 20% were liver-related, 10% had hepatopancreatic biliary etiology, and 10% had unknown etiology. A strong association between the sonographic findings in the BES and the RH was found in the variables "Sonographic Murphy sign" (V = 0.859; p = 0.001), "Cholelithiasis/Gallbladder sludge" (V = 0.840; p = 0.001), and "Intrahepatic biliary tract dilatation" (V = 0.717; p = 0.006). Adequate measures of agreement between the findings of the radiographer and radiologist were obtained for the "Sonographic Murphy sign" (k = 0.664; p = 0.001) and the presence of "Cholelithiasis/Gallbladder sludge" (k = 0.712; p = 0.000).

Conclusion

Major biliary abnormalities were detected in patients with RUQ pain in BES using sonography. The correlation between the sonographic findings obtained by the sonographers at BES and those obtained by radiologists at the RH in Portugal was strong, showing that POCUS screening could be extended to other similar settings; however, more studies are needed.

The Accuracy of Point-of-Care Ultrasound (POCUS) in Acute Gallbladder Disease

There is increasing recognition that point-of-care ultrasound (POCUS), performed by the clinician at the bedside, can be a natural extension of the clinical examination—the modern abdominal “stethoscope” and provides an opportunity to expedite the care pathway for patients with acute gallbladder disease. The primary aims of this study were to benchmark the accuracy of surgeon-performed POCUS in suspected acute gallbladder disease against standard radiology or pathology reports and to compare time to POCUS diagnosis with time to definitive imaging. This prospective single-arm observational cohort study was conducted in four hospitals in Ireland, Italy, and Portugal to assess the accuracy of POCUS against standard radiology in patients with suspected acute biliary disease (ClinicalTrials.govIdentifier: NCT02682368). The findings of surgeon-performed POCUS were compared with those on definitive imaging or surgery. Of 100 patients recruited, 89 were suitable for comparative analysis, comparing POCUS with radiological findings in 84 patients and with surgical/histological findings in five. The overall global accuracy of POCUS was 88.7% (95% CI, 80.3–94.4%), with a sensitivity of 94.7% (95% CI, 85.3–98.9%), a specificity of 78.1% (95% CI, 60.03–90.7%), a positive likelihood ratio (LR+) of 4.33 and negative likelihood ratio (LR) of 0.07. The mean time from POCUS to the final radiological report was 11.9 h (range 0.06–54.9). In five patients admitted directly to surgery, the mean time between POCUS and incision was 2.30 h (range 1.5–5), which was significantly shorter than the mean time to formal radiology report. Sixteen patients were discharged from the emergency department, of whom nine did not need follow-up. Our study is one of the very few to demonstrate a high concordance between surgeon-performed POCUS of patients without a priori radiologic diagnosis of gallstone disease and shows that the expedited diagnosis afforded by POCUS can be reliably leveraged to deliver earlier definitive care for patients with acute gallbladder pathology, as the general surgeon skilled in POCUS is uniquely positioned to integrate it into their bedside assessment.

Spectrum of imaging findings in hyperplastic cholecystosis and potential mimics

Adenomyomatosis and cholesterolosis of the gallbladder, collectively termed hyperplastic cholecystosis, are commonly encountered incidental findings on imaging studies performed for a variety of indications including biliary colic or nonspecific abdominal pain. These pathologies are rarely the source of symptoms, generally considered benign and do not require further work-up. However, their imaging characteristics can overlap with more sinister conditions that should not be missed. In this review, the imaging findings of adenomyomatosis and cholesterolosis will be reviewed followed by other gallbladder pathologies that might mimic these conditions radiologically. Important differentiating factors will be discussed that can aid the radiologist in making a more confident imaging diagnosis.

Ultrasound Matrix Imaging-Part II: The Distortion Matrix for Aberration Correction Over Multiple Isoplanatic Patches

This is the second article in a series of two which report on a matrix approach for ultrasound imaging in heterogeneous media. This article describes the quantification and correction of aberration, i.e. the distortion of an image caused by spatial variations in the medium speed-of-sound. Adaptive focusing can compensate for aberration, but is only effective over a restricted area called the isoplanatic patch. Here, we use an experimentally-recorded matrix of reflected acoustic signals to synthesize a set of virtual transducers. We then examine wave propagation between these virtual transducers and an arbitrary correction plane. Such wave-fronts consist of two components: (i) An ideal geometric wave-front linked to diffraction and the input focusing point, and; (ii) Phase distortions induced by the speed-of-sound variations. These distortions are stored in a so-called distortion matrix, the singular value decomposition of which gives access to an optimized focusing law at any point. We show that, by decoupling the aberrations undergone by the outgoing and incoming waves and applying an iterative strategy, compensation for even high-order and spatially-distributed aberrations can be achieved. After a numerical validation of the process, ultrasound matrix imaging (UMI) is applied to the in-vivo imaging of a gallbladder. A map of isoplanatic modes is retrieved and is shown to be strongly correlated with the arrangement of tissues constituting the medium. The corresponding focusing laws yield an ultrasound image with drastically improved contrast and transverse resolution. UMI thus provides a flexible and powerful route towards computational ultrasound.

Point-of-care ultrasound for acute abdomen: 5W1H (Translated version)

In this paper, point-of-care ultrasound (POCUS) for the initial diagnosis and the management of acute abdomen is discussed. POCUS is supposed to be executed mainly by doctors other than ultrasound specialists anytime and anywhere such as in the emergency room or the intensive care unit. Although it seems rather difficult to cover the wide spectrum of organs as well as diseases causing acute abdominal pain, the author advocates a "six approach" for the diagnosis and triage of acute abdomen, which consists of scanning at eight points in less than 5 min. With this method, the attending doctor can diagnose most of the diseases frequently encountered in patients with acute abdomen, which can help patients avoid unnecessary examinations or admissions. However, users of POCUS should be aware of its limitations, especially when they are using pocket-sized ultrasound equipment. Therefore, users should be careful when ruling out a disease even when they cannot find any pathological findings, and consider the need for further examinations such as US done by specialists with high-end equipment or CT. Since there has been no standard curriculum in Japan for POCUS training that should deal with basic physics and techniques for US, normal abdominal anatomy, typical pathological US findings, and interventional US, the establishment of a learning program for doctors and training of experts as instructors of POCUS are needed.

Point-of-Care Abdominal Ultrasonography (POCUS) on the Way to the Right and Rapid Diagnosis

Point-of-Care ultrasound (POCUS) is based on target ultrasound that is performed wherever a patient is being treated, and by a non-radiologist directly involved in the patient’s care. It is used either for quick diagnosis or procedural guidance. Abdominal pain is one of the most common complaints in emergency departments, and POCUS can help in the differentiation of patients who need additional diagnostic tests or hospital treatment, which eventually reduces the overall costs of health care. POCUS has high sensitivity and specificity in abdominal pathology, it can be helpful in the evaluation of biliary, intestinal, and urinary tract, and it is especially used in trauma. Additionally, the gold standard for abdominal aortic aneurysm detection, follow up and screening is precisely this diagnostic procedure. Unfortunately, the quality of ultrasound examination can be affected by the experience of the physician performing it and the patient’s body weight. There is no doubt that POCUS is being increasingly recognized, but all motivated physicians should be provided with dedicated tutors and enough time for learning. This would certainly help to implement this diagnostic method as a routine in emergency and critical care departments, and significantly shorten the time until definitive diagnosis.

Chemotherapy-Induced Toxicities: An Imaging Primer

The Coronavirus Disease of 2019 (COVID-19) pandemic has caused significant delays in the delivery of cancer treatments in Canada. As cancer treatment and imaging volumes return to normal, radiologists will encounter more cases of chemotherapy-induced toxicities. These toxicities have varied appearances on imaging, and can affect multiple organ systems. The purpose of this review is to offer a unified resource for general radiologists regarding the imaging appearances of chemotherapy-induced toxicities.

Unusual Presentation of Gallbladder Fossa Abscess Following Open Cholecystectomy in a Patient With Cholecystitis: A Case Report

Cholecystectomy is one of the most commonly performed surgical interventions, and laparoscopic cholecystectomy is the standard intervention with open cholecystectomies having declined nowadays. Similar to other surgical procedures, cholecystectomy carries its own risks including sepsis, bleeding, damage to surrounding tissues, bile leakage, and abscess formation. Abscess formation can be due to a variety of reasons such as infection or gallstone spillage during surgery with the latter being more common to laparoscopic surgery. Here we describe a patient with an unusual presentation of gallbladder fossa abscess following open cholecystectomy.

[Cholecystectomy in acute cholecystitis-a surgical emergency or elective in the next day's program?]

BACKGROUND

The treatment of acute cholecystitis is based on the German S3 guidelines on "Prophylaxis, diagnosis and treatment of gallstones", which was updated in 2018. If the patient has no contraindications for surgery, early laparoscopic cholecystectomy is the treatment of choice.

OBJECTIVE

Current meta-analyses and studies confirm that for most patients the optimal period of time for surgical treatment is the first 24 h after hospitalization; however, there is an ongoing controversial discussion on how strictly the 24 h rule should be adhered to and under which circumstances it may be valid to deviate from it.

MATERIAL AND METHOD

A systematic analysis of the current literature and a clinical evaluation were carried out.

RESULTS

For the diagnosis of an acute cholecystitis, laparoscopic cholecystectomy should be carried out within the first 24 h after hospitalization regardless of the age and comorbidities of the patient as well as the severity of inflammation. If there is no special emergency situation, under certain circumstances surgery can be performed in the next day's program.

DISCUSSION

This recommendation for early surgery for high-risk patients has so far been controversially discussed; however, current studies confirm that the advantages of early surgery outweigh the disadvantages also for this group of patients. The surgical risk should be individually assessed and be included in the treatment decision.

Retrospective analysis of the sonographic and computed tomographic features of gallbladder empyema

OBJECTIVE

Early detection of complicated cholecystitis, particularly gallbladder empyema, is important. Yet only a handful of patients are correctly diagnosed prior to intervention. The purpose of this study was to evaluate the sonographic and computed tomography features associated with gallbladder empyema compared with the intraoperative findings and histopathological examination.

MATERIALS AND METHODS

We retrospectively reviewed ultrasound and CT images for 146 patients with clinical suspicion of cholecystitis from January 2013 until December 2018. Ultrasound criteria reviewed included calculus, wall thickening, pericholecystic fluid, gallbladder distension and presence of echogenic material within the gallbladder. For CT, criteria reviewed were wall thickening, gallbladder distension, mucosal enhancement, pericholecystic fluid and hyperdense bile with an attenuation value of more than 20 HU. Association of these findings was made with intraoperative and pathological findings of 85 patients with proven gallbladder empyema.

RESULTS

Sonographic signs that were statistically significantly associated with gallbladder empyema (p < 0.05) were thickened gallbladder wall (mean 5.4 versus 3.0 mm), distended gallbladder (mean 8.5 versus 6.4cm), pericholecystic fluid and echogenic material within the gallbladder. No significant association between gallstones and gallbladder empyema. Scores of two and more out of four significant sonographic findings were found to have an association with higher chances of developing gallbladder empyema (p < 0.05, odds ratio: 10). None of the CT features was found to be significant with gallbladder empyema (p > 0.05).

CONCLUSION

A combination of few ultrasound features has a high significant association with gallbladder empyema. Thus, in the proper clinical setting, these findings should alarm the sonographic operator on the possibility of gallbladder empyema.

Evaluation and management of the surgical abdomen

PURPOSE OF REVIEW

The aim of this study was to describe important features of clinical examination for the surgical abdomen, relevant investigations, and acute management of common surgical problems in the critically ill.

RECENT FINDINGS

Lactate remains a relatively nonspecific marker of gut ischemia. Dual energy computed tomography (DECT) scan can improve diagnosis of bowel ischemia. Further evidence supports intravenous contrast during CT scan in critically ill patients with acute kidney injury. Outcomes for acute mesenteric ischemia have failed to improve over time; however, increasing use of endovascular approaches, including catheter-directed thrombolysis, may decrease need for laparotomy in the appropriate patient. Nonocclusive mesenteric ischemia remains a challenging diagnostic and management dilemma. Acalculous cholecystitis is managed with a percutaneous cholecystostomy and is unlikely to require interval cholecystectomy. Surgeon comfort with intervention based on point-of-care ultrasound for biliary disease is variable. Mortality for toxic megacolon is decreasing.

SUMMARY

Physical examination remains an integral part of the evaluation of the surgical abdomen. Interpreting laboratory investigations in context and appropriate imaging improves diagnostic ability; intravenous contrast should not be withheld for critically ill patients with acute kidney injury. Surgical intervention should not be delayed for the patient in extremis. The intensivist and surgeon should remain in close communication to optimize care.

Diagnostic significance of the CT rim sign in cases of gangrenous cholecystitis

PURPOSE

To evaluate the association between the CT rim sign and gangrenous cholecystitis (GC) and increased surgical difficulty.

METHOD

Patients who had a contrast enhanced CT of the abdomen and pelvis, followed by non-elective cholecystectomy were analyzed. The scans were reviewed for the CT rim sign by radiologists blinded to the pathologic and clinical outcomes. Demographic and clinical characteristics were compared between patients with and without GC using t-tests or Wilcoxon ranked sum test for continuous variables, and Fishers' exact test for categorical variables, when appropriate. A logistic regression model was fitted with multiple risk factors. Odds ratios as well as 95% confidence intervals were then calculated for the risk factors. A secondary analysis predicting increased surgical difficulty, defined as an operative time of greater than 2 h or increased conversion rate to open surgery, was also examined.

RESULTS

A total of 100 patients were included; 20 of which had GC. On imaging, patients with GC were more likely to have a CT rim sign (65% vs 32.5%, OR = 3.80, 95% CI: 1.24-12.7, p = 0.011). The presence of the CT rim sign did not reach a statistically significant association with an operative time >2 h or conversion to open case (56.52% vs 33.77%, OR = 2.55, p = 0.056).

CONCLUSION

The CT rim sign can be utilized to raise the possibility of GC, however the presence of the CT rim sign does not demonstrate an association with increased surgical difficulty.

Role of MSCT in the diagnosis of perforated gall bladder (a retrospective study)

Background

Although gall bladder perforation (GBP) is not common, it is considered a life-threating condition, and the possibility of occurrence in cases of acute cholecystitis must be considered. The aim of this study was to assess the role of multi-slice computed tomography (MSCT) in the assessment of GBP.

Results

It is a retrospective study including 19 patients that had GBP out of 147, there were 11 females (57.8%) and 8 males (42.1%), aged 42 to 79 year (mean age 60) presented with acute abdomen or acute cholecystitis. All patients were examined with abdominal ultrasonography and contrast-enhanced abdominal MSCT after written informed consent was obtained from the patients. This study was between January and December 2018. Patients with contraindications to contrast-enhanced computed tomography (CT) (pregnancy, acute kidney failure, or allergy to iodinated contrast agents) who underwent US only were excluded. Patients with other diagnoses, such as acute diverticulitis of the right-sided colon or acute appendicitis, were excluded. The radiological findings were evaluated such as GB distention; stones; wall thickening, enhancement, and defect; pericholecystic free fluid or collection; enhancement of liver parenchyma; and air in the wall or lumen. All CT findings are compared with the surgical results. Our results revealed that the most important and diagnostic MSCT finding in GBP is a mural defect. Nineteen patients were proved surgically to have GBP.

Conclusion

GBP is a rare but very serious condition and should be diagnosed and treated as soon as possible to decrease morbidity and mortality. The most accurate diagnostic tool is the CT, MSCT findings most specific and sensitive for the detection of GBP and its complications.

Imaging-based algorithmic approach to gallbladder wall thickening

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

Added value of 2D shear wave imaging of the gallbladder bed of the liver for acute cholecystitis

Purpose

The purpose of this study was to evaluate whether shear wave elastography (SWE) and the shear wave dispersion slope (SWD) obtained from 2-dimensional shear wave imaging (2D-SWI) of the gallbladder (GB) bed of the liver could be helpful in the diagnosis of acute cholecystitis.

Methods

We included 44 patients referred for abdominal ultrasonography (US) under the impression of acute cholecystitis from April 2018 to March 2019. Patients with chronic liver disease were excluded from this study. In addition to routine upper abdominal US, we performed 2D-SWI including liver stiffness measurements by SWE and SWD, which reflects tissue viscosity. 2D-SWI was performed at the GB bed of the liver through the right intercostal approach at least 3 times with different frames. We assessed typical US findings and the added value of 2D-SWI in diagnosing acute cholecystitis. Histopathologic results of surgical specimens were used as the standard of reference. If a surgical specimen was unavailable, a bile fluid test or clinical follow-up for more than 3 months served as the reference standard.

Results

The optimal cutoff values for SWE and SWD were 8 kPa and 10.9 (m/sec)/kHz, respectively. In the univariate analysis, SWE, GB distension, and sludge were predictive factors of acute cholecystitis. In the multivariate analysis, categorized SWE was the only significant predictor (P<0.01). By using 2D-SWI, the diagnostic performance of two readers did not significantly increase, although the inter-reader agreement improved (k=0.654-0.778).

Conclusion

2D-SWI of the GB bed of the liver could be helpful for diagnosing acute cholecystitis.

The Treatment of Gallstone Disease

BACKGROUND

Gallstone disease affects up to 20% of the European population, and cholelithiasis is the most common reason for hospitalization in gastroenterology.

METHODS

This review is based on pertinent publications retrieved by a selective search of the literature, including the German clinical practice guidelines on the diagnosis and treatment of gallstones and corresponding guidelines from abroad.

RESULTS

Regular physical activity and an appropriate diet are the most important measures for the prevention of gallstone disease. Transcutaneous ultrasonography is the paramount method of diagnosing gallstones. Endoscopic retrograde cholangiography should only be carried out as part of a planned therapeutic intervention; endosonography beforehand lessens the number of endoscopic retrograde cholangiographies that need to be performed. Cholecystectomy is indicated for patients with symptomatic gallstones or sludge. This should be performed laparoscopically with a four-trocar technique, if possible. Routine perioperative antibiotic prophylaxis is not necessary. Cholecystectomy can be performed in any trimester of pregnancy, if urgently indicated. Acute cholecystitis is an indication for early laparoscopic cholecystectomy within 24 hours of admission to hospital. After successful endoscopic clearance of the biliary pathway, patients who also have cholelithiasis should undergo laparoscopic cholecystectomy within 72 hours.

CONCLUSION

The timing of treatment for gallstone disease is an essential determinant of therapeutic success.

Gallstones top to toe: what the radiologist needs to know

Gallstone-related disease can have significant associated morbidity and mortality worldwide. The incidence of gallstone-related disease in the Western world is on the increase. There are multiple different pathological manifestations of gallstone disease: the presentation, diagnosis and associated complications of which vary significantly depending on anatomical location. The role of imaging in gallstone-related disease is broad with radiology playing an essential role in the diagnosis, management and follow-up of gallstone-related pathologies. This paper distills the broad range of gallstone-related pathologies into an anatomical map, discussing the disease processes involved at each point along the biliary tree and reviewing the strengths and weaknesses of different imaging modalities for each distinct disease process.

Point-of-care ultrasound for the acute abdomen in the primary health care

Point-of-care ultrasound (POCUS) is a focused examination, which is performed and interpreted at the bedside by the treating physician answering a specific clinical question. It is currently utilized as an essential adjunct to physical examination in many medical specialties. Recent advances in technology have made POCUS machines portable, affordable, and could be used with minimal training even by nonradiologists. This review aims to cover the fundamental physics of POCUS and its applications for diagnosing the acute abdomen in the primary health care including the most common causes encountered by family physicians. These are acute appendicitis, acute cholecystitis, renal colic, ectopic pregnancy, acute diverticulitis, bowel obstruction, and abdominal aortic aneurysm. We hope to encourage primary care physicians to incorporate POCUS in their routine clinical practice. We also highlight challenges encountered when using POCUS in the primary health care including limited availability and the need for proper training. Furthermore, we review the POCUS results when performed by primary health-care physicians. Integrating POCUS in primary health care empowers primary health-care physicians to provide high-quality, safe, and cost-effective care to the patients.

Imaging of Acute Hepatobiliary Dysfunction

Abdominal pain is a common cause for emergency department visits in the United States, and biliary tract disease is the fifth most common cause of hospital admission. Common causes of acute hepatobiliary include gallstones and its associated complications and multiple other hepatobiliary etiologies, including infectious, inflammatory, vascular, and neoplastic causes. Postoperative complications of the biliary tract can result in an acute abdomen. Imaging of the hepatobiliary tree is integral in the diagnostic evaluation of acute hepatobiliary dysfunction, and imaging of the biliary tree requires a multimodality approach utilizing ultrasound, computed tomography, nuclear medicine, and MR imaging.

Infections of the Hepatobiliary System

Hepatobiliary infections account for a small but clinically important proportion of emergency department presentations. They present a clinical challenge due to the broad range of imaging characteristics on presentation. Recognition of complications is imperative to drive appropriate patient care and resource utilization to avoid diagnostic pitfalls and avert adverse patient outcomes. A thorough understanding of anatomy infectious pathology of hepatobiliary system is essential in the emergency setting to confidently diagnose and guide medical intervention. Many presentations of hepatobiliary infection have characteristic imaging features on individual imaging modalities with others requiring the assimilation of findings of multiple imaging modalities along with incorporating the clinical context and multispecialist consultation. Familiarity with the strengths of individual imaging modalities in the radiologists' arsenal is imperative to guide the appropriate utilization of resources, particularly in the emergent time sensitive setting. Accurate identification and diagnosis of hepatobiliary infections is vital for appropriate patient care and management stratification.

Surgeon-performed point-of-care ultrasound for acute cholecystitis: indications and limitations: a European Society for Trauma and Emergency Surgery (ESTES) consensus statement

BACKGROUND

Acute cholecystitis (AC), frequently responsible for presentation to the emergency department, requires expedient diagnosis and definitive treatment by a general surgeon. Ultrasonography, usually performed by radiology technicians and reported by radiologists, is the first-line imaging study for the assessment of AC. Targeted point-of-care ultrasound (POCUS), particularly in the hands of the treating surgeon, may represent an evolution in surgical decision-making and may expedite care, reducing morbidity and cost.

METHODS

This consensus guideline was written under the auspices of the European Society of Trauma and Emergency Surgery (ESTES) by the POCUS working group. A systematic literature search identified relevant papers on the diagnosis and treatment of AC. Literature was critically-appraised according to the GRADE evidence-based guideline development method. Following a consensus conference at the European Congress of Trauma & Emergency Surgery (Valencia, Spain, May 2018), final recommendations were approved by the working group, using a modified e-Delphi process, and taking into account the level of evidence of the conclusion.

RECOMMENDATIONS

We strongly recommend the use of ultrasound as the first-line imaging investigation for the diagnosis of AC; specifically, we recommend that POCUS may be adopted as the primary imaging adjunct to surgeon-performed assessment of the patient with suspected AC. In line with the Tokyo guidelines, we strongly recommend Murphy's sign, in conjunction with the presence of gallstones and/or wall thickening as diagnostic of AC in the correct clinical context. We conditionally recommend US as a preoperative predictor of difficulty of cholecystectomy. There is insufficient evidence to recommend contrast-enhanced ultrasound or Doppler ultrasonography in the diagnosis of AC. We conditionally recommend the use of ultrasound to guide percutaneous cholecystostomy placement by appropriately-trained practitioners.

CONCLUSIONS

Surgeons have recently embraced POCUS to expedite diagnosis of AC and provide rapid decision-making and early treatment, streamlining the patient pathway and thereby reducing costs and morbidity.

Utility of MR Imaging in Abdominopelvic Emergencies

Acute abdominopelvic pain, a common symptom in emergency department patients, is challenging given the spectrum of differential diagnoses encompassing multiple organ systems, ranging from benign self-limiting to life-threatening and emergent. Diagnostic imaging is critical given its high accuracy and management guidance. A contrast-enhanced computed tomography (CT) scan is preferred given its widespread availability and speed of acquisition. MR imaging may be appropriate, usually performed for specific indications with tailored protocols. It is accurate for diagnosis and may be an alternative to CT. This article discusses the advantages and disadvantages, protocols, and appearances of MR imaging of common diagnoses.

Right Upper Quadrant Pain: Ultrasound First!

Acute right upper quadrant (RUQ) pain is a common presenting symptom in emergency departments and outpatient medical practices, and is most commonly attributable to biliary and hepatic pathology. Ultrasound should be used as a first-line imaging modality for the diagnosis of gallstones and cholecystitis, as it allows the differentiation of medical and surgical causes of upper abdominal pathology, and in many circumstances is sufficient to guide patient management. Knowledge of strengths and limitations of ultrasound in the evaluation of RUQ is paramount in correct diagnosis. A spectrum of RUQ pathology for which a RUQ ultrasound examination should reasonably be considered as the initial imaging modality of choice will be reviewed.

Biliary and pancreatic complications of molecular targeted therapies in cancer imaging

The purpose of this review is to familiarize radiologists with the different imaging manifestations of biliary and pancreatic toxicity of molecular targeted therapies. The advent of molecular targeted therapies for cancer treatment has prompted radiologists to be familiar with these new molecules, their patterns of response, and their class-specific toxicities. While liver and bowel toxicities have been extensively reported in literature, less is known about the pathogenesis and imaging of toxicity involving the pancreatobiliary system. Biliary and pancreatic toxicity of molecular targeted therapies present with variable manifestations and varying degrees of severity, from asymptomatic liver function tests elevation to acute pancreatitis or cholecystitis. Management of these conditions depends on the clinical scenario and the severity of the findings. In this article, we will (1) present the various classes of molecular targeted therapies most commonly associated with biliary and pancreatic toxicity; (2) illustrate imaging findings of drug-associated biliary and pancreatic injuries and their possible differential diagnosis; and (3) provide a guide for management of these conditions.

Noninvasive Imaging of the Biliary System Relevant to Percutaneous Interventions

Clinical data such as history, physical examination, and laboratory tests are useful in identifying patients with biliary obstruction and biliary sources of infection. However, if intervention is planned, noninvasive imaging is needed to confirm the presence, location, and extent of the disease process. Currently, the most commonly available and used noninvasive modalities are ultrasound (US), computed tomography (CT), magnetic resonance (MR), and nuclear medicine hepatobiliary scintigraphy (HIDA). US is quick, portable, readily available, and is commonly the first imaging modality used when biliary pathology is suspected. It is excellent in the detection of cholelithiasis and acute cholecystitis but is limited in detecting choledocholithiasis. CT is excellent at detecting infected postoperative fluid collections, bilomas, biliary obstruction, and biliary infection but is limited in the detection of cholelithiasis. Therefore, US may be more useful than CT for the initial screening of acute biliary disease. MR has inherent advantages over CT, as it does not use ionizing radiation, can be done without intravenous contrast, and its detection of cholelithiasis is not affected by the internal composition of the stone. Magnetic resonance cholangiopancreatography can be used to determine the cause and location of biliary obstruction but is limited in the detection of small stones and the evaluation of the biliary tract near the ampulla. HIDA is used to evaluate for cholecystitis, biliary obstruction, and bile leaks. The main limitation is its lack of anatomical detail, and it is therefore frequently performed in conjunction with other described modalities.

How to Avoid Nontherapeutic Laparotomy in Patients With Multiple Organ Failure of Unknown Origin. The Role of CT Scan Revisited

Diagnosis of intra-abdominal diseases in critically ill patients remains a clinical challenge. Physical examination is unreliable whereas exploratory laparotomy may aggravate patient's condition and delay further evaluation. Only a few studies have investigated the place of computed tomography (CT) on this hazardous situation. We aimed to evaluate the ability of CT to prevent unnecessary laparotomy during the management of critically ill patients. Charts of all consecutive patients who had undergone an emergency nontherapeutic laparotomy from 1996 to 2013 were retrospectively studied and patient's demographic, clinical characteristics, and surgical findings were collected. During this period 59 patients had an unnecessary laparotomy. Fifty-one patients had at least one preoperative imaging and 36 had a CT scan. CT scans were interpreted to be normal (n = 12), with minor anomalies (n = 10), or major anomalies (pneumoperitoneum, portal venous gas/pneumatosis intestinalis, thickened gallbladder wall, and small bowel obstruction signs). Surgical exploration was performed through laparotomy (n = 55) or laparoscopy. Overall mortality was 37% with a median survival after surgery of 7 days. In univariate analysis, hospitalization in ICU before surgical exploration was the only factor related to death. In our series CT scans, objectively interpreted, helped avoid unnecessary surgical exploration in 61% of our patients.

Safety and effectiveness of percutaneous cholecystostomy in critically ill children who are immune compromised

BACKGROUND

Acalculous cholecystitis is known to develop in critically ill patients without cystic duct obstruction. In the past, treatment for acalculous cholecystitis has been cholecystectomy; however, many children who are critically ill are Percutaneous cholecystostomy is likely the procedure of choice in this subgroup of patients.

OBJECTIVE

To assess the safety and effectiveness of percutaneous cholecystostomy in critically ill and immune-compromised children with acalculous cholecystitis.

MATERIALS AND METHODS

Retrospective review of immune-compromised and critically ill children who underwent percutaneous cholecystostomy between 2006 and 2013. Diagnostic imaging performed included ultrasound, CT and hepatobiliary scintigraphy. Every percutaneous cholecystostomy was performed using imaging guidance.

RESULTS

Ten critically ill and immune-compromised children with acalculous cholecystitis underwent percutaneous cholecystostomy. Seven boys and 3 girls, ranging in age from 10 months to 15 years 8 months, were treated. Six of the immune-compromised children had received a bone marrow transplant for leukemia (5 children) or severe combined immunodeficiency (SCID) (1 child), and ranged from 18 to 307 days post bone marrow transplant at the time of their percutaneous cholecystostomy. Of the remaining four immune-compromised children with acalculous cholecystitis who underwent percutaneous cholecystostomy, two had leukemia, one had SCID and lymphoma, and the fourth was undergoing treatment for undifferentiated germ cell tumor. The 10 percutaneous gallbladder drains were placed using a transhepatic approach, except one unintentional transperitoneal approach. There were no complications. Three gallbladder drains were removed in Interventional Radiology. Those three patients had a return to normal gallbladder function and didn't require cholecystectomy. Two drains were removed during cholecystectomy and another as an outpatient. Four patients died in the hospital due to multiorgan system failure, with indwelling gallbladder drains.

CONCLUSION

Percutaneous cholecystostomy is a safe procedure in immune-compromised and critically ill children with acalculous cholecystitis. Percutaneous cholecystostomy may obviate the need for future cholecystectomy.

Hollow organ abdominal ischemia, part II: clinical features, etiology, imaging findings and management

Acute hollow organ ischemia commonly presents with acute pain prompting radiologic evaluation and almost always requires urgent treatment. Despite different risk factors and anatomic differences, ischemia is commonly due to low flow states but can also be due to arterial and venous occlusion. Radiologic diagnosis is critical as many present with nonspecific symptoms. Contrast-enhanced computed tomography (CT) is the modality of choice. Magnetic resonance imaging (MRI) is preferred in suspected appendicitis in pregnant patients and is superior in biliary necrosis. This article provides a pictorial review of the CT/MRI features of hollow abdominal organ ischemia while highlighting key clinical features, pathogenesis, and management.

A Rare Case of Emphysematous Cholecystitis

Emphysematous cholecystitis is an acute infection of the gallbladder wall caused by gas-forming organisms. It is infrequent with insidious onset and diagnosed by the use of radiographs detecting presence of air within the gallbladder wall or lumen. The report describes the case of a 42-year-old alcoholic male who presented with sudden onset of pain in the right upper quadrant of abdomen, fever and bilious vomiting of two days duration. The patient did not have symptoms of jaundice. Emergency partial cholecystectomy was done and the culture directed antibiotics were given. The patient was followed up for 4 years and he remained asymptomatic.

Cancer therapy related complications in the liver, pancreas, and biliary system: an imaging perspective

Awareness of cancer therapy-induced toxicities is important for all clinicians treating patients with cancer. Cancer therapy has evolved to include classic cytotoxic agents in addition to newer options such as targeted agents and catheter-directed chemoembolisation. Several adverse affects can result from the wide array of treatments including effects on the liver, pancreas, and biliary system that can be visualised on imaging. These complications include sinusoidal obstruction syndrome, fatty liver, pseudocirrhosis, acute hepatitis, pancreatitis, pancreatic atrophy, cholecystitis, biliary sclerosis, and biliary stasis. Many of these toxicities are manageable and reversible with supportive therapies and/or cessation of cancer therapy. The objective of this review is to discuss the imaging findings associated with cancer therapy-induced toxicity of the liver, biliary system, and pancreas.

TEACHING POINTS

• Cancer therapy can have adverse effects on the hepatobiliary system and pancreas. • Cancer therapy-induced toxicities can be visualised on imaging. • Knowledge of imaging changes associated with cancer therapy complications can improve treatment.

EFFECTS OF TWO CONTRAST INJECTION PROTOCOLS ON FELINE AORTIC AND HEPATIC ENHANCEMENT USING DYNAMIC COMPUTED TOMOGRAPHY

This prospective study compared aortic and hepatic enhancement achieved using a contrast injection protocol with a fixed rate of 5 ml/s vs. that achieved using a protocol with fixed injection duration of 20 s in eight cats. Cats were assigned into two groups (Group 1, rate 5 ml/s; Group 2, duration 20 s). The dose of contrast was the same in both groups (740 mgI/kg). Regions of interest (ROI) were drawn in the aorta and liver for transverse scans acquired at the hepatic hilus. Time to peak aortic enhancement occurred significantly earlier in Group 1 (M = 11s, SD = 1.63) than in Group 2 (M = 25.5 s, SD = 2.51). Peak aortic enhancement was significantly higher in Group 1 (M = 1906.51 HU, SD = 368.64) than in Group 2 (M = 745.08 HU, SD = 201.84). Duration of aortic enhancement equal to or above 300 HU was statistically longer in Group 2 (M = 24.5 s, SD = 8.39) than in Group 1 (M = 10 s, SD = 1.63). There were no significant differences in time to peak liver enhancement, peak liver enhancement, or duration of hepatic arterial phase between groups. Findings supported the hypothesis that longer injection duration results in a broader bolus geometry with a longer time to peak and a lower peak aortic enhancement in cat. This strong influence of injection duration on timing of aortic enhancement may help future users optimize protocols for CT angiography of the aorta and multiphasic evaluation of the liver, pancreas, and small intestine.

Current radiological strategies for the assessment of right lower quadrant abdominal pain

Right lower quadrant abdominal pain is a common clinical entity. Imaging and the radiologistplay an integral role in achieving a diagnosis, so guiding prompt management of patients.This review discusses the spectrum of pathology and imaging findings, and highlights and contrasts the preferred imaging modalities in different subsets of patients.

Accuracy of ultrasonography in the diagnosis of acute calculous cholecystitis: review of the literature

Background

To evaluate the accuracy of ultrasonography in the diagnosis of acute calculous cholecystitis in comparison with other imaging modalities.

Methods

The authors performed a search of the Medline/ PubMed (National Library of Medicine, Bethesda, Maryland) for original research and review publications examining the accuracy of ultrasonography in the diagnosis of acute calculous cholecystitis. The search design utilized a single or combination of the following terms : (1) acute cholecystitis, (2) ultrasonography, (3) computed tomography, (4) magnetic resonance cholangiopancreatography and (5) cholescintigraphy. This review was restricted to human studies and to English-language literature. Four authors reviewed all the titles and subsequent the abstract of 198 articles that appeared appropriate. Other articles were recognized by reviewing the reference lists of significant papers. Finally, the full text of 31 papers was reviewed.

Results

Sonography is still used as the initial imaging technique for evaluating patients with suspected acute calculous cholecystitis because of its high sensitivity at the detection of GB stones, its real-time character, and its speed and portability. Cholescintigraphy still has the highest sensitivity and specificity in patients who are suspected of having acute cholecystitis. However, due to a combination of reasons including logistic drawbacks, broad imaging capability and clinician referral pattern the use of cholescintigraphy is limited in clinical practice. CT is particularly useful for evaluating the many complications of acute calculous cholecystitis. The lack of widespread availability of MRI and the relatively high cost prohibits its primary use in patients with acute calculous cholecystitis.

Conclusions

US is currently considered the preferred initial imaging technique for patients who are clinically suspected of having acute calculous cholecystitis.

Small- and medium-sized hepatocellular carcinomas: monopolar radiofrequency ablation with a multiple-electrode switching system-mid-term results

PURPOSE

To prospectively assess the safety and mid-term therapeutic effectiveness of monopolar radiofrequency (RF) ablation with a multiple-electrode switching system for treating small- and medium-sized (≤ 5 cm) hepatocellular carcinomas (HCCs).

MATERIALS AND METHODS

The institutional review board approved this prospective study, and all patients gave informed consent. From February 2009 to January 2010, 166 patients (110 men and 56 women; age range, 38-86 years; mean age, 62 years ± 10 [standard deviation]) with 166 HCCs less than or equal to 5 cm in diameter were treated with monopolar RF ablation with a multiple-electrode switching system. One of three experienced radiologists performed the RF ablation. Technique effectiveness, ablation volume and time, and major complications were evaluated by means of computed tomography (CT) immediately after RF ablation and at follow-up CT examinations at 1 month and then every 3 months after the procedure. The overall survival, disease-free survival, and local tumor progression-free survival rates were evaluated by using the Kaplan-Meier method.

RESULTS

The technique effectiveness rate determined 1 month after RF ablation was 99.4%. Mean ablation parameters were as follows: volume, 85 cm(3) ± 54; maximum diameter, 61 mm ± 13; and minimum diameter, 43 mm ± 11. The major complication rate was 4.8%. The 6-month and 1-, 2-, and 3-year local tumor progression rates were 2%, 6%, 10%, and 11%, respectively. The overall survival rates at 1, 2, and 3 years after RF ablation were 99%, 97%, and 96%, and corresponding local tumor progression-free survival rates were 94%, 90%, and 89%, respectively. The disease-free survival rates at 1, 2, and 3 years after RF ablation were 75%, 60%, and 54%, respectively.

CONCLUSION

Monopolar RF ablation with a multiple-electrode switching system in small- and medium-sized HCCs was safe and efficient, and it provided successful local tumor control and high local tumor progression-free survival rates because an adequate ablation volume was obtained.

Chronically symptomatic patients with undetectable gall bladder on ultrasonography could benefit from early cholecystectomy

90 percent of symptomatic patients undergoing cholecystectomy have cholelithiasis with 10% categorized as asymptomatic cholecystitis. In both instances, the gallbladder is evident on ultrasonography. In children with symptomatic biliary dyspepsia, the decision to proceed to cholecystectomy is made difficult if choleliths are not seen on ultrasonography. This decision is made even more difficult if the gallbladder itself is not seen on repeated imaging. In a cohort of 54 cholecystectomies, 3 cases, with recurrent right upper quadrant pain and undetectable gallbladders on repeat ultrasonography, were identified. After prolonged observation all underwent successful cholecystectomy. Histology demonstrated a markedly fibrotic and thickened gallbladder in all. Given this experience, we suggest that nonvisibility of the gallbladder, in fact, maybe be a feature of a chronic acalculous cholecystitis. We advise consideration of cholecystectomy for chronic biliary dyspepsia where repeat ultrasonography fails to demonstrate a gallbladder.

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

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