The infected liver: radiologic-pathologic correlation

Large Mesenchymal Hepatic Hamartoma in Pediatric Age: A Case Report

Benign liver tumors are infrequently observed in the pediatric age group, with an incidence reported at 0.7 per million population annually. Among these tumors, mesenchymal hamartoma constitutes 18%-29%. Imaging studies commonly reveal a well-marginated, solitary mass, often measuring up to 30 cm. The mass, primarily located in the right liver lobe (75% of cases), may exhibit a pedunculated structure. We present a case of a 1-year-and-9-month-old boy diagnosed with hepatic mesenchymal hamartoma. A contrast-enhanced computed tomography of the abdomen and magnetic resonance imaging (MRI) were performed and demonstrated a large multiloculated septated liver lesion measuring approximately 13.6 × 17.7 cm, demonstrating multiple partially thickened internal septations. The procedure was done for the patient in the form of an extended right hepatectomy with segment 4A and cholecystectomy.

Discontinuous peripheral enhancement of focal liver lesions on CT and MRI: outside the box of typical cavernous hemangioma

The discontinuous peripheral enhancement is a pattern of enhancement usually attributed to typical cavernous hemangioma, that is the most common benign solid lesion of the liver. The discontinuous peripheral enhancement, however, may be encountered in many other benign and malignant focal liver lesions as an atypical presentation or evolution, and hemangiomas with discontinuous peripheral hyperenhancement on hepatic arterial phase may not always have the typical post-contrast pattern on portal venous and delayed phases. Therefore, abdominal radiologists may be challenged in their practice by lesions with discontinuous peripheral enhancement. This pictorial essay aims to review the spectrum of benign and malignant focal liver lesions that may show discontinuous peripheral enhancement. A particular point of interest is the diagnostic tree pathway that may guide the radiologists in the differential diagnosis.

Sutton's Law: A Lesson in Decision-Analysis from the Past…and Present

In 1960, Dr. William Dock, visiting professor at Yale, discussed the case of a young girl with an unknown liver disease. Dock recommended biopsy, invoking bank robber Willie Sutton's words "that's where the money is." Drs. Petersdorf and Beeson, in attendance that day, included the following in their 1961 publication on fever of unexplained origin, "We are indebted to Dr. William Dock for the term Sutton's Law. It recommends proceeding immediately to the diagnostic test most likely to provide a diagnosis, and deplores the tendency to carry out a battery of 'routine' examinations in conventional sequence." Thereafter, Sutton's Law became an acclaimed aphorism advocating pursuit of tissue, because of its specificity for achieving diagnostic certainty. However, its popularity was fleeting, as formal medical decision-analysis (FMDA) became the standard. In the 1940s and 1950s, pioneers in the field laid the groundwork, and by the 1980s, clinician researchers had introduced the science into everyday clinical practice. The original version of Sutton's Law neglected the reality that FMDA is more than specificity, tissue, and absolute certainty. The newer version encourages clinicians to employ and prioritize their "routine" interview questions, physical examination assessments, and laboratory tests that provide clarity to differentiate between disease and no disease, to influence favorably the patient's management, and to discard those evaluations more likely to provide misleading results. Dock, Petersdorf, and Beeson may not have spoken the language of FMDA, but they were adept at applying its principles. Without them, and the unknown medical student who made the diagnosis of schistosomiasis, there would be no Sutton's Law. For many, it is an obsolete and apocryphal aphorism valuable solely for touting the importance of specificity in tissue diagnosis. For others, it has evolved, remaining relevant as an authentic lesson in decision-analysis, past and present.

A Nomogram Based on a Non-Invasive Method to Distinguish Between Gram-Positive and Gram-Negative Bacterial Infections of Liver Abscess

Purpose

The diagnosis of liver abscess (LA) caused by Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB) depends on ultrasonography, but it is difficult to distinguish the overlapping features. Valuable ultrasonic (US) features were extracted to distinguish GPB-LA and GNB-LA and establish the relevant prediction model.

Materials and Methods

We retrospectively analyzed seven clinical features, three laboratory indicators and 11 US features of consecutive patients with LA from April 2013 to December 2023. Patients with LA were randomly divided into training group (n=262) and validation group (n=174) according to a ratio of 6:4. Univariate logistic regression and LASSO regression were used to establish prediction models. The performance of the model was evaluated using area under the curve(AUC), calibration curves, and decision curve analysis (DCA), and subsequently validated in the validation group.

Results

A total of 436 participants (median age: 55 years; range: 42-68 years; 144 women) were evaluated, including 369 participants with GNB-LA and 67 with GPB-LA, respectively. A total of 11 predictors by LASSO regression analysis, which included gender, age, the liver background, internal gas bubble, echogenic debris, wall thickening, whether the inner wall is worm-eaten, temperature, diabetes mellitus, hepatobiliary surgery and neutrophil(NEUT). The performance of the Nomogram prediction model distinguished between GNB-LA and GPB-LA was 0.80, 95% confidence interval [CI] (0.73-0.87). In the validation group, the AUC of GNB was 0.79, 95% CI (0.69-0.89).

Conclusion

A model for predicting the risk of GPB-LA was established to help diagnose pathogenic organism of LA earlier, which could help select sensitive antibiotics before the results of drug-sensitive culture available, thereby shorten the treatment time of patients.

Benign and malignant focal liver lesions displaying rim arterial phase hyperenhancement on CT and MRI

Rim arterial phase hyperenhancement is an imaging feature commonly encountered on contrast-enhanced CT and MRI in focal liver lesions. Rim arterial phase hyperenhancement is a subtype of arterial phase hyperenhancement mainly present at the periphery of lesions on the arterial phase. It is caused by a relative arterialization of the periphery compared with the center of the lesion and needs to be differentiated from other patterns of peripheral enhancement, including the peripheral discontinuous nodular enhancement and the corona enhancement. Rim arterial phase hyperenhancement may be a typical or an atypical imaging presentation of many benign and malignant focal liver lesions, challenging the radiologists during imaging interpretation. Benign focal liver lesions that may show rim arterial phase hyperenhancement may have a vascular, infectious, or inflammatory origin. Malignant focal liver lesions displaying rim arterial phase hyperenhancement may have a vascular, hepatocellular, biliary, lymphoid, or secondary origin. The differences in imaging characteristics on contrast-enhanced CT may be subtle, and a multiparametric approach on MRI may be helpful to narrow the list of differentials. This article aims to review the broad spectrum of focal liver lesions that may show rim arterial phase hyperenhancement, using an approach based on the benign and malignant nature of lesions and their histologic origin. CRITICAL RELEVANCE STATEMENT: Rim arterial phase hyperenhancement may be an imaging feature encountered in benign and malignant focal liver lesions and the diagnostic algorithm approach provided in this educational review may guide toward the final diagnosis. KEY POINTS: Several focal liver lesions may demonstrate rim arterial phase hyperenhancement. Rim arterial phase hyperenhancement may occur in vascular, inflammatory, and neoplastic lesions. Rim arterial phase hyperenhancement may challenge radiologists during image interpretation.

Characterization of research trends and prospects on hepatic echinococcosis over the past forty years: a bibliometric analysis

BACKGROUND

The distribution of hepatic echinococcosis (HE) is extensive, significantly impacting public health and economic development. Therefore, analyzing global collaboration networks and tracking developmental trends over the past four decades are crucial. This study aimed to demonstrate collaboration in the field of HE and explore key topics and future directions.

MATERIALS AND METHODS

Bibliometric analyses were conducted using CiteSpace, Bibliometrix package of R, and VOSviewer software on HE-related studies from the Web of Science Core Collection published before 1 August 2023.

RESULTS

This study identified 2605 records published in 196 journals by 9860 authors from 2607 institutes in 90 countries. Publications significantly notably increased in 2021. Developing countries like Turkey and China made notable contributions, while developed countries like the USA had higher average citation rates. The largest nodes in every cluster of the collaboration network were Hacettepe University, Tehran University, Xinjiang Medical University, Salford University, and the University of Pavia, and the top-producing authors were Wen H, Vuitton DA, Gottstein B, and Craig PS. Keyword co-occurrence analysis suggested that surgical techniques and novel drugs targeting combined immune checkpoints are the main therapeutic approaches in the future.

CONCLUSION

Although developing countries had significantly contributed to publications on HE, the citation rate for individual articles from developed countries was significantly higher. Additionally, advancements in surgical techniques and novel drugs targeting combined immune checkpoints may emerge as the next research focus and developmental direction.

Technical and Clinical Outcome of Low-Milliampere CT Fluoroscopy-Guided Percutaneous Drainage Placement in Abdominal Fluid Collections after Liver Transplantation: A 16-Year Retrospective Analysis of 50 Consecutive Patients

PURPOSE

Evaluation of the effectiveness of CT-guided drainage (CTD) placement in managing symptomatic postoperative fluid collections in liver transplant patients. The assessment included technical success, clinical outcomes, and the occurrence of complications during the peri-interventional period.

METHODS

Analysis spanned the years 2005 to 2020 and involved 91 drain placement sessions in 50 patients using percutaneous transabdominal or transhepatic access. Criteria for technical success (TS) included (a) achieving adequate drainage of the fluid collection and (b) the absence of peri-interventional complications necessitating minor or prolonged hospitalization. Clinical success (CS) was characterized by (a) a reduction or normalization of inflammatory blood parameters within 30 days after CTD placement and (b) the absence of a need for surgical revision within 60 days after the intervention. Inflammatory markers in terms of C-reactive protein (CRP), leukocyte count and interleukin-6, were evaluated. The dose length product (DLP) for various intervention steps was calculated.

RESULTS

The TS rate was 93.4%. CS rates were 64.3% for CRP, 77.8% for leukocytes, and 54.5% for interleukin-6. Median time until successful decrease was 5.0 days for CRP and 3.0 days for leukocytes and interleukin-6. Surgical revision was not necessary in 94.0% of the cases. During the second half of the observation period, there was a trend (p = 0.328) towards a lower DLP for the entire intervention procedure (median: years 2013 to 2020: 623.0 mGy·cm vs. years 2005 to 2012: 811.5 mGy·cm). DLP for the CT fluoroscopy component was significantly (p = 0.001) lower in the later period (median: years 2013 to 2020: 31.0 mGy·cm vs. years 2005 to 2012: 80.5 mGy·cm).

CONCLUSIONS

The TS rate of CT-guided drainage (CTD) placement was notably high. The CS rate ranged from fair to good. The reduction in radiation exposure over time can be attributed to advancements in CT technology and the growing expertise of interventional radiologists.

Hepatic abscessation in dogs: A multicenter study of 56 cases (2010-2019)

OBJECTIVE

To investigate the clinical findings, treatment strategies, and outcomes in dogs with confirmed hepatic abscessation.

DESIGN

Retrospective cohort study from 2010 to 2019.

SETTING

Multicenter study.

ANIMALS

Fifty-six client-owned dogs with hepatic abscessation confirmed by culture, cytology, or histopathology.

MEASUREMENTS AND MAIN RESULTS

Dogs were presented for lethargy (39/56), hyporexia (31/56), and vomiting (26/56). Abnormal physical examination findings included increased temperature (41/56) and abdominal pain (22/54). CBCs revealed neutrophilia (31/49), toxic changes (25/49), anemia (28/49), and thrombocytopenia (23/49). Biochemical analyses revealed increased alkaline phosphatase (45/50), increased alanine aminotransferase (40/50), hypoalbuminemia (25/48), and hyperbilirubinemia (19/49). Hypoglycemia was found in 13 of 49 dogs. Hepatic abscesses ranging from 0.5 to 15 cm in diameter were identified ultrasonographically in 37 of 48 dogs; 19 of 37 had solitary abscesses, and 18 of 37 had multifocal abscessation. Escherichia coli was the most commonly cultured organism, isolated in 18 of 42 cases. Histopathology revealed underlying hepatic neoplasia in 10 of 47 dogs. Surgical management was performed in 41 of 49 dogs, and 35 of 41 survived to discharge. Medical management was performed in 8 of 49 dogs, and 5 of 8 survived to discharge. With univariate analysis, hypoglycemia and multifocal abscessation were associated with decreased odds of survival (odds ratio [OR]: 0.2, 95% confidence interval [CI]: 0.03-0.9, P = 0.04; OR: 0.07, 95% CI: 0.01-0.6, P = 0.02, respectively). With multivariate analysis, only multifocal abscessation was associated with decreased odds of survival (OR: 0.09, 95% CI: 0.01-0.87, P = 0.04).

CONCLUSIONS

Hepatic abscessation, although rare, should remain a differential diagnosis for dogs presenting with nonspecific clinical signs and increase liver enzyme activities, especially with concurrent increased temperature and neutrophilia. Rate of survival to discharge for dogs in this study was consistent with previously reported survival rates, with 40 of 56 (71%) of the total population surviving to discharge. No variables assessed were able to predict survival to discharge; however, hypoglycemia and multifocal abscessation should be assessed in larger populations to determine prognostic significance.

ACR Appropriateness Criteria® Abnormal Liver Function Tests

Liver function tests are commonly obtained in symptomatic and asymptomatic patients. Various overlapping lab patterns can be seen due to derangement of hepatocytes and bile ducts function. Imaging tests are pursued to identify underlying etiology and guide management based on the lab results. Liver function tests may reveal mild, moderate, or severe hepatocellular predominance and can be seen in alcoholic and nonalcoholic liver disease, acute hepatitis, and acute liver injury due to other causes. Cholestatic pattern with elevated alkaline phosphatase with or without elevated γ-glutamyl transpeptidase can be seen with various causes of obstructive biliopathy. Acute or subacute cholestasis with conjugated or unconjugated hyperbilirubinemia can be seen due to prehepatic, intrahepatic, or posthepatic causes. We discuss the initial and complementary imaging modalities to be used in clinical scenarios presenting with abnormal liver function tests. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Cancer Therapy-related Hepatic Injury in Children: Imaging Review from the Pediatric LI-RADS Working Group

The liver is the primary organ for the metabolism of many chemotherapeutic agents. Treatment-induced liver injury is common in children undergoing cancer therapy. Hepatic injury occurs due to various mechanisms, including biochemical cytotoxicity, hepatic vascular injury, radiation-induced cytotoxicity, and direct hepatic injury through minimally invasive and invasive surgical treatments. Treatment-induced liver injury can be seen contemporaneous with therapy and months to years after therapy is complete. Patients can develop a combination of hepatic injuries manifesting during and after treatment. Acute toxic effects of cancer therapy in children include hepatitis, steatosis, steatohepatitis, cholestasis, hemosiderosis, and vascular injury. Longer-term effects of cancer therapy include hepatic fibrosis, chronic liver failure, and development of focal liver lesions. Quantitative imaging techniques can provide useful metrics for disease diagnosis and monitoring, especially in treatment-related diffuse liver injury such as hepatic steatosis and steatohepatitis, hepatic iron deposition, and hepatic fibrosis. Focal liver lesions, including those developing as a result of treatment-related vascular injury such as focal nodular hyperplasia-like lesions and hepatic perfusion anomalies, as well as hepatic infections occurring as a consequence of immune suppression, can be anxiety provoking and confused with recurrent malignancy or hepatic metastases, although there often are imaging features that help elucidate the correct diagnosis. Radiologic evaluation, in conjunction with clinical and biochemical screening, is integral to diagnosing and monitoring hepatic complications of cancer therapy in pediatric patients during therapy and after therapy completion for long-term surveillance. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material See the invited commentary by Ferraciolli and Gee in this issue.

Nanoceria as Safe Contrast Agents for X-ray CT Imaging

Cerium oxide nanoparticles (CeO2NPs) have exceptional catalytic properties, rendering them highly effective in removing excessive reactive oxygen species (ROS) from biological environments, which is crucial in safeguarding these environments against radiation-induced damage. Additionally, the Ce atom's high Z number makes it an ideal candidate for utilisation as an X-ray imaging contrast agent. We herein show how the injection of albumin-stabilised 5 nm CeO2NPs into mice revealed substantial enhancement in X-ray contrast, reaching up to a tenfold increase at significantly lower concentrations than commercial or other proposed contrast agents. Remarkably, these NPs exhibited prolonged residence time within the target organs. Thus, upon injection into the tail vein, they exhibited efficient uptake by the liver and spleen, with 85% of the injected dose (%ID) recovered after 7 days. In the case of intratumoral administration, 99% ID of CeO2NPs remained within the tumour throughout the 7-day observation period, allowing for observation of disease dynamics. Mass spectrometry (ICP-MS) elemental analysis confirmed X-ray CT imaging observations.

Diagnosing Infectious Hepatic Cysts in an Older Patient With Multiple Skin Masses: A Case Report

Among the most severe complications of hepatic cystic diseases is infectious hepatic cysts (IHCs). IHCs may appear mainly among immunocompromised hosts. However, older patients have a variety of immunological conditions. The detection of the factors suppressing immunity is essential for patients with IHCs. Herein, we present the case of an 86-year-old woman admitted to the emergency department with a fever. We suspected IHCs based on changes in abdominal ultrasound findings. After multiple follow-ups to determine the cause of the fever that was unresponsive to treatment, we discovered debris in the cyst that had not been present at the time of the initial presentation. The patient was subsequently treated with percutaneous transhepatic drainage and tazobactam/piperacillin. The investigation of the causes of immunosuppression clarified the multiple skin masses. The biopsy of the mass clarified diffuse large B cell lymphoma without lymph node swellings. Consecutive ultrasound can detect findings missed during the initial presentation and changes that occur within a short period. The detection of the causes of immunosuppression is essential even among older patients with IHCs for better care among older patients.

Misdiagnosis of food-borne foreign bodies outside of the digestive tract on magnetic resonance imaging: Two case reports

BACKGROUND

Patients with foreign bodies in the digestive tract are often encountered, but complete penetration of a foreign body through the gastrointestinal tract is rare, and the choice of imaging method is very important. Improper selection may lead to missed diagnosis or misdiagnosis.

CASE SUMMARY

An 81-year-old man was diagnosed as having a liver malignancy after he took magnetic resonance imaging and positron emission tomography/computed tomography (CT) examinations. The pain improved after the patient accepted gamma knife treatment. However, he was admitted to our hospital 2 mo later due to fever and abdominal pain. This time, he received a contrast-enhanced CT scan, which showed fish-boon-like foreign bodies in the liver with peripheral abscess formation, then he went to the superior hospital for surgery. It lasted for more than 2 mo from the onset of the disease to the surgical treatment. A 43-year-old woman with a 1 mo history of a perianal mass with no obvious pain or discomfort was diagnosed as having an anal fistula with the formation of a local small abscess cavity. Clinical perianal abscess surgery was performed, and fish bone foreign body was found in perianal soft tissue during the operation.

CONCLUSION

For patients with pain symptoms, the possibility of foreign body perforation should be considered. Magnetic resonance imaging is not comprehensive and that a plain computed tomography scan of the pain area is necessary.

Point‑of‑care ultrasound for the diagnosis of liver abscess in a patient with HIV in the emergency department: A case report

A liver abscess is an entity that is rarely observed in the emergency department; therefore, it requires timely diagnosis by the clinicians who support this service. The early diagnosis of a liver abscess is challenging as variable and non-specific symptoms are present; furthermore, symptoms may differ in patients with human immunodeficiency virus (HIV) infection. To date, reports on the presentation of diagnostic ultrasound with point-of-care ultrasonography (PoCUS) are limited. The present case report study describes a patient diagnosed with HIV and the presence of a liver abscess confirmed by PoCUS performed in an emergency department. The patient presented with abdominal pain upon palpation in the right hypochondrium and in the thoracoabdominal area, which became more severe with inspiration. PoCUS revealed a hypodense intrahepatic image observed between segments VII and VI, with internal echoes suggestive of a liver abscess. Moreover, it was decided to perform tomography-guided percutaneous drainage of the liver abscess. Antibiotic treatment with ampicillin/sulbactam and IV metronidazole was also commenced. The patient presented clinical improvement and was discharged on the third day.

Fulminating herpes simplex hepatitis

Herpes simplex virus (HSV) is a rare cause of acute hepatitis in patients with chronic immunosuppression, including Crohn's disease. HSV hepatitis has the propensity to cause acute liver failure and death. The presenting signs and symptoms can be nonspecific, thereby causing the diagnosis to go overlooked with inadequate management, leading to a high mortality rate. We report a case of a 31-year-old male on chronic prednisone treatment for Crohn's disease who unexpectedly died. Subsequently, an autopsy showed HSV hepatitis as the cause of death. Thus, although a rare complication, HSV hepatitis should always be kept in mind as a fatal complication in patients with acute hepatitis and chronic immunosuppression.

Cystic liver lesions: a pictorial review

Hepatic cysts (HC) are sac-like structures mainly filled with liquid and showing a distinct membrane. They are usually found incidentally through imaging. A wide spectrum of imaging patterns may be observed for common and uncommon, neoplastic and non-neoplastic diseases. While simple hepatic cysts occur frequently and do not require any treatment or follow-up, non-typical cysts should be carefully analysed to avoid misdiagnosing a lesion that would require appropriate management. Therefore, adequate knowledge of all the relevant imaging patterns is critical to secure an accurate diagnosis. The aim of this review is to describe the imaging features of the different types of hepatic cysts.

Pyogenic liver abscess: contrast-enhanced ultrasound allows morpho-evolutive classification and guides personalized management

Aim: The aim of this study is to propose a contrast-enhanced ultrasound (CEUS)-based morphologic classification of pyogenic liver abscess (PLA) reflecting different evolutive stages and to assess the added value of CEUS in the management of PLA. Methods: Forty-four PLAs of different etiologies in 44 patients (male/female = 24/20; mean age 66 ± 14.7 years) were evaluated with ultrasound (US) B-mode and CEUS (using SonoVue). PLAs were mainly located in the right lobe (n = 28, 63.6%) with a mean diameter of 6.8 cm [standard deviation (SD) ± 3.2, range 1.7–15 cm]. Conventional US findings were categorized as the presence and extension of liquified areas, echogenicity and echostructure of the index lesion. Peripheral hyperenhancing rim, transient segmental enhancement, hyperenhancing septa and “honeycomb” aspect were considered PLA hallmarks in the arterial phase after contrast agent injection. CEUS results were judged as clinically relevant if they modified the approach to percutaneous treatment in comparison with pre-operative US B-mode findings. Results: CEUS was superior to US B-mode as to depiction of PLA internal echostructure and enabled identification of 4 evolutive stages of PLA: type I (tumor-like), type II (“honeycomb”), type III (multiloculated with incomplete septa), and type IV (cystic-like). In 22 cases (67.4%) out of 34 who underwent percutaneous treatment, the operator tailored percutaneous approach according to PLA internal echostructure observed during CEUS exam. Conclusions: CEUS depicts the internal structure of PLA so allowing a morpho-evolutive classification of PLA and provides invaluable information for immediately tailoring the management to the single case. By showing the structure of PLA more precisely, CEUS allows a morpho-evolutive PLA classification and guides tailored management in the single case.

Human Adenovirus Associated Hepatic Injury

Human adenovirus (HAdV) is a common virus, but the infections it causes are relatively uncommon. At the same time, the methods for the detection of HAdV are varied, among which viral culture is still the gold standard. HAdV infection is usually self-limited but can also cause clinically symptomatic in lots of organs and tissues, of which human adenovirus pneumonia is the most common. In contrast, human adenovirus hepatitis is rarely reported. However, HAdV hepatitis has a high fatality rate once it occurs, especially in immunocompromised patients. Although human adenovirus hepatitis has some pathological and imaging features, its clinical symptoms are not typical. Therefore, HAdV hepatitis is not easy to be found in the clinic. There are kinds of treatments to treat this disease, but few are absolutely effective. In view of the above reasons, HAdV hepatitis is a disease that is difficult to be found in time. We reviewed and summarized the previously reported cases, hoping to bring some relatively common characteristics to clinicians, so as to facilitate early detection, early diagnosis, and early treatment of patients.

Imaging Spectrum of Intrahepatic Mass-Forming Cholangiocarcinoma and Its Mimickers: How to Differentiate Them Using MRI

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy, with mass-forming growth pattern being the most common. The typical imaging appearance of mass-forming ICC (mICC) consists of irregular ring enhancement in the arterial phase followed by the progressive central enhancement on portal venous and delayed phases. However, atypical imaging presentation in the form of hypervascular mICC might also be seen, which can be attributed to distinct pathological characteristics. Ancillary imaging features such as lobular shape, capsular retraction, segmental biliary dilatation, and vascular encasement favor the diagnosis of mICC. Nevertheless, these radiological findings may also be present in certain benign conditions such as focal confluent fibrosis, sclerosing hemangioma, organizing hepatic abscess, or the pseudosolid form of hydatid disease. In addition, a few malignant lesions including primary liver lymphoma, hemangioendothelioma, solitary hypovascular liver metastases, and atypical forms of hepatocellular carcinoma (HCC), such as scirrhous HCC, infiltrative HCC, and poorly differentiated HCC, may also pose a diagnostic dilemma by simulating mICC in imaging studies. Diffusion-weighted imaging and the use of hepatobiliary contrast agents might be helpful for differential diagnosis in certain cases. The aim of this manuscript is to provide a comprehensive overview of mICC imaging features and to describe useful tips for differential diagnosis with its potential mimickers.

The Persistent Approach to Diagnose Infectious Hepatic Cysts in a Patient With Recurrent Fever: A Case Report

Diagnosing infectious hepatic cysts (IHCs) can be challenging. Moreover, patients with IHCs may present with various symptoms. Diagnosis of IHCs can be even more difficult in patients with multiple liver cysts. For appropriate diagnosis, the detection of infectious sections in the liver is essential. However, diagnosing and determining definite treatments for patients with IHCs can be particularly challenging when they have polycystic liver disease. We present a case of a 70-year-old man who visited a rural community hospital with a primary complaint of recurrent fever and pain in the right upper quadrant. Based on his clinical history, physical examination findings, and imaging findings after three admissions, he was diagnosed with IHCs. This case demonstrates the challenges in diagnosing IHCs in patients with multiple hepatic cysts and highlights the necessity of a careful follow-up of clinical histories and findings of definitive imaging tests in the diagnosis of IHCs in patients with recurrent fever. To diagnose IHCs effectively, a comprehensive approach including history taking, physical examination, and diagnostic testing, is essential. IHCs should be considered by physicians when patients present with recurrent fever. To avoid missing IHCs, physicians in outpatient departments should continuously follow up on patients’ IHC-related symptoms such as fever and right upper quadrant pain.

Hepatobiliary and Pancreatic Adverse Events

The expanded approval of immune checkpoint inhibitors (ICIs) for the treatment of multiple cancer types has offered patients more opportunities in treatment selection and survival.Hepatotoxicity is a well-recognized immune-related adverse event (irAE) associated with treatment with ICI. It is considered a type of drug-induced liver injury (DILI). Depending on the specific ICI and whether the patient receives single- or dual-drug therapy, the incidence of hepatotoxicity in general could be as high as 30%. As more patients receive treatment with ICI, more cases of hepatotoxicity are expected to occur. Clinicians must exercise close pharmacovigilance to recognize liver-related irAEs early.ICI-mediated hepatobiliary toxicity (or "IMH") generally presents as asymptomatic elevations of alanine transaminase and aspartate transaminase, with or without alkaline phosphatase elevation. Some patients may present with jaundice, fever, or malaise. Rarely, it may cause liver failure and death. The diagnosis of IMH is made after careful exclusion of other causes of acute hepatitis based on medical history, laboratory evaluation, imaging, and liver histological findings. In clinically significant cases of IMH, the management involves discontinuation of ICI followed by close monitoring and the initiation of immunosuppression. Current society guidelines, which are not based on robust evidence, specify treatment recommendations depending on the grade of liver injury, according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. However, our clinical experience suggests possible alternatives, including lower corticosteroid dosing with adjunct therapies. Whereas current guidelines endorse permanent cessation of future ICI treatment in patients diagnosed with grades 3-4 IMH, published clinical experience suggests potential for flexibility when assessing for candidacy of resuming ICI.Because histologic bile duct injury has been observed in cases ascribed to IMH, ICI-mediated cholangiopathic disease probably exists on a spectrum within IMH. Even extrahepatic bile duct involvement has been observed. This phenotype warrants special considerations in treatment and surveillance.ICI-related cholecystitis has been rarely reported in the literature. Management follows current standards of care for typical cases of cholecystitis. No relationship with ICI-mediated cholangiopathic disease has been observed.Assessing for and managing ICI-associated pancreatic injury remain challenging to the clinician. Many cases of asymptomatic serum lipase elevation are detected on routine labs without clinical signs or symptoms of typical acute pancreatitis. However, symptomatic patients should be initially managed like traditional cases of acute pancreatitis requiring hospitalization for evaluation and inpatient management.

Beyond the Liver Function Tests: A Radiologist's Guide to the Liver Blood Tests

Liver blood tests (often also known as liver chemistries, liver tests, or the common misnomer liver function tests) are routinely used in diagnosis and management of hepatobiliary disease. Abnormal liver blood test results are often the first indicator of hepatobiliary disease and a common indication for abdominal imaging with US, CT, or MRI. Most of the disease entities can be categorized into hepatocellular or cholestatic patterns, with characteristic traits on liver blood tests. Each pattern has a specific differential, which can help narrow the differential diagnosis when combined with the clinical history and imaging findings. This article reviews the major liver blood tests as well as a general approach to recognizing common patterns of hepatobiliary disease within these tests (hepatocellular, cholestatic, acute liver failure, isolated hyperbilirubinemia). Examples of hepatobiliary disease with hepatocellular or cholestatic patterns are presented with characteristic test abnormalities and imaging findings. The commonly encountered scenario of chronic hepatitis with possible fibrosis is also reviewed, with discussion of potential further imaging such as elastography. The role of liver blood tests and imaging in evaluating complications of hepatic transplant is also discussed. Overall, integrating liver blood test patterns with imaging findings can help the radiologist accurately diagnose hepatobiliary disease, especially in cases where imaging findings may not allow differentiation between different entities. ^©RSNA, 2021.

Misidentification of hepatic tuberculosis as cholangiocarcinoma: A case report

BACKGROUND

Hepatic tuberculosis (TB) is uncommon clinically. Because of a lack of specific signs, characteristic symptoms and clinical manifestations and because pathological samples are difficult to obtain, hepatic TB is easily missed or misdiagnosed.

CASE SUMMARY

A 62-year-old Chinese man presented with jaundice for 1 wk and no abnormal laboratory tests other than elevated bilirubin, aminotransferases and C-reactive protein. Computed tomography (CT) of the abdomen showed a mass in the left lobe of the liver and hepatic hilum with striped calcified foci. Mild enhancement was visible at the edges, along with extensive intrahepatic biliary ductal dilatation in the right lobe of the liver. In the arterial phase of both CT and magnetic resonance imaging, the main trunk and right branch of the portal artery were partially visualized. Magnetic resonance cholangiopancreatography (MRCP) indicated that the left lobe of the liver and most of the bile ducts in the hilum were not visible. Pathological examination revealed coagulative necrosis, and granulomatous nodules were seen around areas of necrosis; therefore, TB was considered.

CONCLUSION

Hepatic tuberculosis is easily misdiagnosed or missed on imaging. Percutaneous puncture biopsy is the most useful tool for definitive diagnosis.

Differentiating infected focal liver lesions from malignant mimickers: value of ultrasound-based radiomics

AIM

To establish an ultrasound-based radiomics model through machine learning methods and then to assess the ability of the model to differentiate infected focal liver lesions from malignant mimickers.

MATERIALS AND METHODS

A total of 104 patients with infected focal liver lesions and 485 patients with malignant hepatic tumours were included, consisting of hepatocellular carcinoma (HCC), cholangiocarcinoma (CC), combined hepatocellular-cholangiocarcinoma (cHCC-CC), and liver metastasis. Radiomics features were extracted from grey-scale ultrasound images. Feature selection and predictive modelling were carried out by dimensionality reduction methods and classifiers. The diagnostic effect of the prediction mode was assessed by receiver operating characteristic (ROC) curve analysis.

RESULTS

In total, 5,234 radiomics features were extracted from grey-scale ultrasound image of every focal liver lesion. The ultrasound-based radiomics model had a favourable predictive value for differentiating infected focal liver lesions from malignant hepatic tumours, with an area under the curve (AUC) of 0.887 and 0.836 (HCC group), 0.896 and 0.766 (CC group), 0.944 and 0.754 (cHCC-CC group), 0.918 and 0.808 (liver metastasis group), and 0.949 and 0.745 (malignant hepatic tumour group) for the training set and validation set, respectively.

CONCLUSIONS

Ultrasound-based radiomics is helpful in differentiating infected focal liver lesions from malignant mimickers and has the potential for use as a supplement to conventional grey-scale ultrasound and contrast-enhanced ultrasound (CEUS).

Amoebic liver abscess in a COVID-19 patient: a case report

BACKGROUND

Amoebiasis is a parasitic disease caused by Entamoeba histolytica, which affects people living in low- and middle-income countries and has intestinal and extraintestinal manifestations. To date, knowledge on coronavirus disease 2019 (COVID-19) coinfection with enteric parasites is limited, and E. histolytica coinfection has not been previously described. Here we present the case of a patient with COVID-19 who, during hospitalisation, presented a clinical picture consistent with an amoebic liver abscess (ALA).

CASE PRESENTATION

A 54-year-old man, admitted as a suspected case of COVID-19, presented to our hospital with dyspnoea, malaise, fever and hypoxaemia. A nasopharyngeal swab was positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse-transcription polymerase chain reaction. After 7 days, he developed diarrhoea, choluria and dysentery. An abdominal ultrasound showed a lesion compatible with a liver abscess; stool examination revealed E. histolytica trophozoites, and additional serology for E. histolytica was positive. After 12 days of treatment with metronidazole, ceftazidime and nitazoxanide, the patient reported acute abdominal pain, and an ultrasound examination revealed free liquid in the abdominal cavity. An emergency exploratory laparotomy was performed, finding 3000 mL of a thick fluid described as "anchovy paste". Computed tomography scan revealed a second abscess. He ended up receiving 21 days of antibiotic treatment and was discharged with satisfactory improvement.

CONCLUSION

Here we present, to the best of our knowledge, the first report of ALA and COVID-19 co-presenting. Based on their pathophysiological similarities, coinfection with SARS-CoV-2 and E. histolytica could change the patient's clinical course; however, larger studies are needed to fully understand the interaction between these pathogens.

Isolated hepatic tuberculosis associated with portal vein thrombosis and hepatitis B virus coinfection: A case report and review of the literature

BACKGROUND

While tuberculosis (TB) itself is a common disease, isolated TB of the liver is a rare entity. Tubercular involvement of the liver is more commonly a part of a disseminated disease of the hepatic parenchyma. In contrast, isolated hepatic TB spread through the portal vein from the gastrointestinal tract is seldom encountered in clinical practice, with only a few sporadic cases and short series available in the current literature. Vascular complications, such as portal vein thrombosis (PVT), have rarely been reported previously.

CASE SUMMARY

A 22-year-old man was hospitalized with complaints of a 3-mo history of fever and weight loss of approximately 10 kg. He had a 10-year hepatitis B virus (HBV) infection in his medical history. Contrast-enhanced computed tomography (CECT) confirmed hepatosplenomegaly, with hypodensity of the right lobe of the liver and 2.1 cm thrombosis of the right branch of the portal vein. A liver biopsy showed epithelioid granulomas with a background of caseating necrosis. Ziehl-Nelson staining showed acid-fast bacilli within the granulomas. The patient was diagnosed with isolated hepatic TB with PVT. Anti-TB therapy (ATT), including isoniazid, rifapentine, ethambutol, and pyrazinamide, was administered. Along with ATT, the patient was treated with entecavir as an antiviral medication against HBV and dabigatran as an anticoagulant. He remained asymptomatic, and follow-up sonography of the abdomen at 4 mo showed complete resolution of the PVT.

CONCLUSION

Upon diagnosis of hepatic TB associated with PVT and HBV coinfection, ATT and anticoagulants should be initiated to prevent subsequent portal hypertension. Antiviral therapy against HBV should also be administered to prevent severe hepatic injury.

Amoebic Liver Abscess: Rare Entity in Recent Times

Intestinal amoebiasis and sequelae such as amoebic liver abscess are rarely reported in the era of modern medicine. Atypical presentation of amoebic liver abscess with high false-positive results on serology in endemic regions poses major diagnostic issues in the developing nations of the world. We report a case of amoebic liver abscess and describe the imaging appearances in a 59-year-old female. A detailed medical history was elicited to determine the etiology of amoebic liver abscess. Furthermore, the diagnosis was confirmed based on serological tests. Percutaneous aspiration of the amoebic liver abscess was performed, and treatment was initiated with intravenous metronidazole followed by diloxanide furoate. The patient has been on follow-up since three months with a negative stool examination and with no complaints of recurrence.

Hepatic Hydatid Cyst With Cystobiliary Communication and Cystoduodenal Fistula

The liver is the most common site affected by hydatid disease. Hepatic hydatid cyst (HHC) with cystoduodenal fistula is an unusual and infrequent complication. We present a 48-year-male diagnosed with an HHC with cystobiliary communication (CBC) and cystoduodenal fistula. The patient underwent partial cystectomy. Intraoperative demonstration of CBC was done with injection propofol, followed by primary closure of the CBC. The duodenal fistula was closed primarily with an omental patch, also known as a Graham patch. The patient improved well without any complications, and there was no recurrence of the symptoms for the subsequent five-month follow-up.

CT of amebic liver abscess: different morphological types with different clinical features

PURPOSE

To identify different morphological types of amebic liver abscess (ALA) based on CT findings and to assess whether they have different clinical features.

METHOD

CT images of 112 symptomatic patients with ALA were analyzed to identify the imaging features distinctive of each morphological type. The following CT findings were investigated: the presence of abscess wall, rim enhancement, edge characteristic, septa, intermediate density zone, and peripheral hypodensity. Abscesses from each type were further evaluated for their clinical presentations, laboratory findings and outcomes.

RESULTS

We identified three types of ALAs: type I, II and III. Type I abscesses (66%) were characterized by absent or incomplete walls, ragged edges and peripheral septa; their edges exhibited irregular and interrupted enhancement. Type II (28%) had a complete wall characterized by rim enhancement and peripheral hypodense halo. Type III (6%) demonstrated a wall but without enhancement. Clinically, type I abscesses presented acutely with severe disease. They had significantly deranged laboratory parameters, higher incidence of rupture and higher rate of inpatient or intensive care unit admission. The severity of the disease prompted immediate percutaneous drainage in most type I abscesses (81%). Two of them died from multiple organ failure. The type II or III abscesses, on the other hand, had delayed presentations with mild to moderate disease, with near normal laboratory findings.

CONCLUSION

ALAs have three different CT morphological types, with different clinical and laboratory features. Percutaneous drainage is indicated in most of type I abscesses.

Comparison of clinical features between immune-related sclerosing cholangitis and hepatitis

Background Immune-related hepatotoxicity is often regarded as immune-related hepatitis (irHepatitis) despite including immune-related sclerosing cholangitis (irSC). This study examined the clinical differences between irSC and irHepatitis. Methods A single-center retrospective study of 530 consecutive patients who received immunotherapy between August 2014 and April 2020 was performed. IrSC and irHepatitis were respectively defined as the radiological presence and absence of bile duct dilation and wall thickness. Results Forty-one patients (7.7%) developed immune-related hepatotoxicity. A CT scan was performed on 12 patients, including 11 of 12 with ≥ grade 3 aminotransferase elevations. IrSC and irHepatitis were diagnosed in 4 (0.8%) and 8 (1.5%) patients, respectively. All the irSC patients had been treated with anti-PD-1. IrHepatitis was more common among patients receiving anti-CTLA-4 than among those receiving anti-PD-1/PD-L1 inhibitors (14%, 7/50 vs. 0.2%, 1/480, P < 0.001). A ≥ grade 2 alkaline phosphatase (ALP) elevation resulting in a cholestatic pattern was seen in all 4 irSC patients. Among the irSC patients, 3 (3/4, 75%) developed ≥ grade 3 aminotransferases elevation. The median duration from the start of immunotherapy until ≥ grade 2 liver enzymes elevation was 257 and 55.5 days in irSC and irHepatitis patients. The median times for progression from grade 2 to 3 liver enzyme elevation were 17.5 and 0 days, respectively. Conclusions IrSC and irHepatitis have different characteristics in the class of immune checkpoint inhibitor and onset pattern. Radiological examination for the diagnosis of irSC should be considered for patients with ≥ grade 2 ALP elevation resulting in a cholestatic pattern. (Registration number J2020-36, Date of registration June 3, 2020)

Urgent ultrasound-guided interventional procedures

Interventional radiology procedures have become a fundamental part of radiology, resulting in faster diagnoses and in safer, more effective, and more precise treatments, all of which are important, and even more so when referring to urgent situations, where time is of the essence. In this context, the use of ultrasound to guide interventional procedures enables real-time viewing in multiple planes that can be done at the patient's bedside, which is a great advantage in critical patients. We review the indications and technical aspects of the most common procedures related with radiological care of urgent patients.

Imaging Spectrum of Granulomatous Diseases of the Abdomen and Pelvis

A granuloma is a compact organization of mature macrophages that forms because of persistent antigenic stimulation. At the microscopic level, granulomas can undergo various morphologic changes, ranging from necrosis to fibrosis, which along with other specialized immune cells define the appearance of the granulomatous process. Accordingly, the imaging features of granulomatous diseases vary and can overlap with those of other diseases, such as malignancy, and lead to surgical excisions and biopsy. However, given the heterogeneity of granulomas as a disease group, it is often hard to make a diagnosis on the basis of the histopathologic features of granulomatous diseases alone owing to overlapping microscopic features. Instead, a multidisciplinary approach is often helpful. Radiologists need to be familiar with the salient clinical manifestations and imaging findings of granulomatous diseases to generate an appropriate differential diagnosis. ^©RSNA, 2021.

Multiple septae as potential protective factors against spontaneous pyogenic liver abscess rupture: a propensity score matching analysis

PURPOSE

The symptoms of spontaneous rupture of a pyogenic liver abscess (PLA) are severe and often life-threatening. Multiple septae are important imaging features of PLA. However, the relationship between septation and abscess rupture is still under debate.

METHODS

Patients diagnosed with PLA from January 2011 to November 2019 in our hospital were included. We collected demographic, clinical, and computed tomography data. Univariate and multivariate analyses determined liver abscess rupture risk factors. The relationship between multiple septae and abscess rupture was evaluated by propensity score matching after matching other influencing factors.

RESULTS

A total of 583 patients of pyogenic liver abscesses were included in the study: 30 ruptured and 553 unruptured. Multivariate analysis revealed diabetes, single lesion, gas formation, left hepatic lobe location, and a diameter > 66.5 mm as independent risk factors for ruptures, while multiple septae were identified as a protective factor. After matching all the influencing factors (excluding multiple septae), multiple septae and abscess rupture maintain a negative relationship.

CONCLUSIONS

Multiple septae were identified as a potentially protective factor against spontaneous pyogenic liver abscess ruptures.

Typical imaging finding of hepatic infections: a pictorial essay

Hepatic infections are frequent in clinical practice. Although epidemiological, clinical and laboratory data may suggest hepatic infection in certain cases, imaging is nearly always necessary to confirm the diagnosis, assess disease extension and its complications, evaluate the response to treatment, and sometimes to make differential diagnoses such as malignancies. Ultrasound (US) is usually the first-line investigation, while computed tomography (CT) and magnetic resonance imaging (MRI) provide better characterization and a more precise assessment of local extension, especially biliary and vascular. The purpose of this article is to describe the typical features and main complications of common hepatic infections. Familiarity with the radiological features of this entity can help suggest the correct diagnosis and the need for further studies as well as determine appropriate and timely treatment.

Hemorrhage and Rupture of an Unusual Benign Liver Lesion in Pregnancy: A Case Report

Liver rupture in pregnancy is an acute condition with significant risk to the mother and fetus. It is known to occur with tumors such as hepatic adenoma, infective causes such as abscess, granulomatous diseases, and parasitic infections, and rarely spontaneously. Most of these conditions have overlapping clinicoradiological findings, almost always requiring histopathological confirmation. We report a case of a ruptured hepatic lesion, with an unusual diagnosis of Bartonella henselae infection causing cat-scratch disease, in a 24-year-old pregnant lady.

Imaging Spectrum of Infections in the Setting of Immunotherapy and Molecular Targeted Therapy

Advances in genomics and immunology are revolutionizing our understanding and treatment of cancer with improved treatment outcomes and patient quality of life. With the increasing use of immunotherapy and molecular targeted therapy, a variety of unusual and/or opportunistic infections are also observed. A variety of factors including use of immunosuppression for immune-mediated adverse effects play an important role for increasing the likelihood of these infections and form the basis of this case-based review. Imaging features of infections arising in patients undergoing immunotherapy regimens have not been previously highlighted. Prompt recognition of the spectrum of mycobacterial, bacterial, invasive fungal and viral pathogens can potentially lead to reduction in the high morbidity and mortality in this patient population.

Other types of diffuse liver disease: is there a way to do it?

There are a variety of less common diffuse liver diseases that can be asymptomatic or cause severe liver dysfunction. For the majority of them, the association of clinical, laboratory, and imaging findings are needed to narrow the differential diagnosis. In this article, we will review and describe the rarer diffuse liver diseases including drug-related liver disease, inflammatory and infectious diseases, and deposition disorders such as amyloidosis, glycogen storage disease, Wilson's disease, and alpha-1 antitrypsin deficiency. Abdominal radiologists should be familiar with the imaging features of different types of diffuse liver diseases to help the multidisciplinary team involved in the treatment of these patients. The data related to some of these conditions are scarce and sometimes experimental, but we want to demonstrate to the reader the value of imaging techniques in their analysis and introduce the potential of new imaging methods.

Primary chondrosarcoma of the liver: A case report

BACKGROUND

Primary chondrosarcoma of the liver are extremely rare. Moreover, there are few reports focusing on typical clinical symptoms and imaging characteristics. Therefore, the diagnosis of chondrosarcoma of the liver remains a challenge.

CASE SUMMARY

A 59-year-old male was admitted due to a lesion occupying the right liver lobe that was found by physical examination. Magnetic resonance imaging showed a lobular mass with high T2 weighted image and low T1 weighted image with enhanced internal separation and edge in the right liver. He was diagnosed with liver cystadenoma by using magnetic resonance imaging. At 3 mo later, the magnetic resonance scan showed that the mass was enlarged. Laparoscopic liver tumor resection was performed with a pathological diagnosis of liver chondrosarcoma. Then he received a surgical resection for the recurrent lesion. However, intrahepatic and abdominal metastases were found again at 8 mo after the second operation. The patient then received conservative management and is now under follow-up.

CONCLUSION

Primary liver chondrosarcoma generally is presented as lobulated and heterogeneous density/signal, cystic, solid masses without calcification with enhanced edge, internal septa and solid part. The imaging features are closely related to pathology, which may be helpful for clinical diagnosis.

Uses of Inflammatory Markers for Differentiation of Intrahepatic Mass-Forming Cholangiocarcinoma from Liver Abscess: Case-Control Study

BACKGROUND

Pyogenic liver abscess (LA) is difficult to distinguish from intrahepatic mass-forming cholangiocarcinoma (IMCC) in the emergency department (ED). We evaluated the predictive ability of white blood cells (WBC) and C-reactive protein (CRP) levels, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and delta neutrophil index (DNI) in LA and IMCC in the ED.

METHODS

Forty patients with IMCC between January 2011 and December 2018 were included in this study. For each patient with IMCC, two control patients with LA were enrolled based on matching age and sex,-i.e., 80 patients with LA.

RESULTS

Inflammatory markers, including WBC, PLR, NLR, DNI, and CRP were significantly higher in the LA group than in the IMCC group. For both groups, the area under the curve (AUC) of the initial CRP value was significantly higher (AUC: 0.909) than that of the initial serum WBC count, PLR, and DNI levels. On multivariable logistic regression analysis with inflammatory markers, serum CRP (odds ratio, 1.290; 95% confidence interval, 1.148-1.449, p < 0.001) was the only significant predictor for differentiation between the LA and IMCC groups.

CONCLUSION

Serum CRP may be a potential inflammatory marker to differentiate IMCC from LA in the ED.

A retrospective study of pyogenic liver abscess caused primarily by Klebsiella pneumoniae vs. non-Klebsiella pneumoniae: CT and clinical differentiation

PURPOSE

The incidence of Klebsiella pneumoniae pyogenic liver abscesses (KP-PLA) is increasing. However, its diagnosis and treatment are often delayed, leading to complications. In this study, we aimed to retrospectively compare computed tomographic (CT) features of KP-PLAs with those of abscesses caused by other bacterial pathogens (non-KP-PLAS) and to further identify prognostic factors for PLA.

METHODS

Data of 219 study patients including clinical presentation, comorbid conditions, metastatic infection, treatment duration, and mortality were retrospectively collated. CT characteristics of abscesses were recorded. Etiology was established by pus and/or blood culture. The differentiating CT features and clinical findings were compared between the monomicrobial KP-PLA and non-KP-PLA groups. Furthermore, factors related to in-hospital case fatality were analyzed.

RESULTS

Multivariate analysis identified thin-walled abscesses, absent rim enhancement, metastatic infection, and absence of underlying biliary tract disease as significant predictors of KP-PLA. With 3/4 criteria applied in combination, a specificity of 96.5% was achieved for KP-PLA diagnosis. The in-hospital mortality rate was 3.7%. Multivariate analysis revealed that diabetes mellitus (P = 0.031), multiple abscesses (P = 0.026), internal gas bubble (P = 0.041), metastatic infection (P = 0.004), and septic shock (P = 0.002) were significantly associated with mortality.

CONCLUSION

Thin-walled abscess, metastatic infection, absence of rim enhancement, and absence of underlying biliary tract disease are potentially useful CT findings for early KP-PLA diagnosis.

Parasitic diseases as a cause of acute abdominal pain: imaging findings

Acute abdominal pain can be seen in cases with parasitic diseases delivered to emergency departments. The diagnosis of the parasitic disease can be delayed because of the similar clinical signs encountered in other frequently seen causes of acute abdomen. Nevertheless, the features detected in imaging scans can be helpful in the diagnosis. The present study aims to raise awareness about abdominal parasitosis in emergency conditions and also to underline the association between imaging findings and the life cycle of parasites with illustrative cases.

Benign Neoplasms, Mass-Like Infections, and Pseudotumors That Mimic Hepatic Malignancy at MRI

A variety of conditions may mimic hepatic malignancy at MRI. These include benign hepatic tumors and tumor-like entities such as focal nodular hyperplasia-like lesions, hepatocellular adenoma, hepatic infections, inflammatory pseudotumor, vascular entities, and in the cirrhotic liver, confluent fibrosis, and hypertrophic pseudomass. These conditions demonstrate MRI features that overlap with hepatic malignancy, and can be challenging for radiologists to diagnose accurately. In this review we discuss the MRI manifestations of various conditions that mimic hepatic malignancy, and highlight features that may allow distinction from malignancy. Level of Evidence 5 Technical Efficacy Stage 3.

Hepatobiliary Adverse Events

Immune checkpoint inhibitors (ICIs) are increasingly used for multiple cancer types. Hepatotoxicity is a reported adverse event of ICI treatment. It can present as asymptomatic elevation of aspartate transaminase and alanine transaminase or symptomatic hepatitis with fever, malaise, and even death in rare cases. The diagnosis of ICI-induced hepatitis is made after exclusion of other etiologies based on medical history, laboratory evaluation, and imaging and histological findings. Treatment of ICI-induced hepatitis consists of ICI discontinuation and immunosuppression in severe cases. Pancreatic injury as asymptomatic lipase elevation or acute pancreatitis-like disease with abdominal pain and evidence on imaging has been documented as a toxicity of ICI therapy. Appropriate treatment of pancreatitis still needs further investigation. Few cases, reports, and series documented cholecystitis and cholangitis as possible adverse events related to ICI therapy as well.