Frequency of benign hepatic lesions incidentally detected with contrast-enhanced thin-section portal venous phase spiral CT

Prevalence of Hepatic Space-Occupying Lesions Based on Sonographic Findings in Patients Referred to Guilan Cohort Center, Iran

Background: Early diagnosis of hepatic lesions can result in more successful treatment. Objectives: The present study aimed to diagnose hepatic space-occupying lesions by sonography in Guilan Cohort Center participants. Methods: In this cross-sectional prospective epidemiological research studies of Iranian adults (PERSIAN) Guilan cohort study (Sowme'eh Sara, Guilan, Iran) conducted in 2014 - 2017, the sample included 960 individuals of both genders, aged 35 - 60 years. A radiologist examined all individuals with sonography to determine hepatic space-occupying lesions. Demographical and clinical characteristics were recorded via a questionnaire. Data analysis was performed using SPSS software (version 16). Results: Only 2.3% of the patients were diagnosed with hepatic lesions such as hemangioma, hepatic cysts, and other lesions with frequencies of 1.1%, 0.8%, and 0.4%, respectively. Also, there was a significant relationship between gender and the presence of hepatic lesions (P < 0.05). The frequencies of hepatic lesions were 1.7% and 3.6% in men and women and 1.6%, 2.5%, and 4.4% in the age groups of 35 - 45, 45 - 55, and over 55 years, respectively. Conclusions: Hemangioma was the most common hepatic lesion diagnosed in ultrasonography examinations. Moreover, the only factor influencing the frequency of hepatic lesions was gender, which was found twice more in women than in men.

Contrast-enhanced ultrasonography for the evaluation of malignant focal liver lesions

In this review, the authors address the analysis of different types of malignant focal liver lesions (FLLs) using contrast-enhanced ultrasonography (CEUS). The specific enhancing patterns of hepatocellular carcinoma, cholangiocarcinoma, and metastases are discussed and exemplified with images. In addition, the use of CEUS in malignant portal vein thrombosis is discussed. The advantages and limitations of CEUS for the analysis of malignant FLLs are also discussed.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver - Update 2020 - WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS), first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications.The 2012 guideline requires updating as previously the differences of the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including the United States Food and Drug Administration (FDA) approval as well as the extensive Asian experience, to produce a truly international perspective.These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCA) and are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis to improve the management of patients.

Simple liver cysts and cystoid lesions in hepatic alveolar echinococcosis: a retrospective cohort study with Hounsfield analysis

BACKGROUND

Alveolar echinococcosis (AE) is a rare zoonosis caused by the larval stage of the tapeworm Echinococcus multilocularis. AE lesions affect the liver in more than 98% of cases. AE lesions have various morphological characteristics that are described in the Echinococcus multilocularis Ulm classification for computed tomography (EMUC-CT). One of these characteristics is a cystoid portion. The aim of the study was to compare the density of simple hepatic cysts with cystoid portions of AE lesions classified on the basis of the EMUC-CT.

RESULTS

Hounsfield Unit (HU) measurements of the cystoid portions of all EMUC-CT type I-IV AE lesions (n = 155) gave a mean of 21.8 ± 17.6, which was significantly different from that of 2.9 ± 4.5 for the simple hepatic cysts (p < 0.0001). The difference between each of the individual AE types and simple hepatic cysts was also significant. In addition, the HU values of the cystoid portions in types I, II and IIIa/b and simple cysts were each significantly different from type IV (p < 0.0001). The HU measurements in type IV presented by far the highest mean.

CONCLUSIONS

The significantly higher density measured in the cystoid portions of hepatic AE lesions offers a good means of differentiation from simple hepatic cysts.

Contrast Enhanced Ultrasound in CT-undetermined Focal Liver Lesions

Purpose: The purpose of this study was to examine the diagnostic accuracy of CEUS in the diagnosis of focal liver lesions, which were undetermined at CT scan. Materials and Methods: From January 2010 to December 2010, patients with CT-undetermined focal liver lesions were included in this study. A total of 78 patients were evaluated: 41 men and 37 women, mean age 61.8 years; age range 30-91 years. All patients were examined with GE LOGIQ 9E ultrasound scanners with contrast-specific software, and SonoVue intravenous bolus. The standard of reference was composite consisting of: percutaneous biopsy, surgical resection, PET/CT and clinical follow-up. Results: The 78 included patients had 163 undetermined focal liver lesions, mean size 1.1 cm, range 0.1-5.3 cm. There were 18 malignant and 145 benign liver lesions, as defined by the standard of reference. In differentiating between benign vs. malignant CEUS demonstrated sensitivity, specificity, PPV, NPV and accuracy of 94.4% (95% CI: 56.3-99.5%), 99.3% (95% CI: 94.9 -99.9%), 94.4% (95% CI: 56.3-99.5%), 99.3% (95% CI: 94.9-99.9%) and 98.7% (95% CI: 94.9-99.7%), respectively. If the CEUS-inconclusive results were assumed to indicate malignancy, then sensitivity, specificity, PPV, NPV and accuracy would be 95.8% (95% CI: 66.4-99.6%), 98.6% (95% CI: 94.4-99.7%), 92.0% (95CI: 65.1-98.6%), 99.3% (95% CI: 95.0-99.9%), 98.2% (95% CI: 94.4-99.5%). Conclusion: The results of this study showed a high diagnostic accuracy for CEUS in undetermined focal liver lesions found by CT. Due to a high diagnostic accuracy of CEUS in this study, it was cautiously concluded that CEUS is useful in differentiating between malignant and benign focal liver lesions in clinical practice.

Prevalence of benign focal liver lesions: ultrasound investigation of 45,319 hospital patients

Purpose

The aim of the study was to determine the sonographic prevalence of benign focal liver lesions on the basis of a population of hospital patients.

Methods

The ultrasound results in a population of (n = 45,319) hospital patients over a period of 10 years were examined retrospectively and evaluated for the diagnosis of benign focal liver lesions [hepatic cysts, hepatic hemangioma, focal nodular hyperplasia (FNH), hepatic adenoma, and focal fatty sparing]. Results that were incomplete or ambiguous were excluded from this study.

Results

At least one of the lesions to be investigated was diagnosed in 15.1% (n = 6839) of the patients of the total population. The most commonly recorded lesion, with a total prevalence of 6.3% (n = 2839), was focal fatty sparing, followed by hepatic cysts with 5.8% (n = 2631). The prevalence of hepatic hemangioma was 3.3% (n = 1640), while that of FNH was 0.2% (n = 81) and that of hepatic adenoma was 0.04% (n = 19). An association between the occurrence of benign focal liver lesions and age was observed.

Conclusions

The calculated prevalence of benign focal liver lesions shows that on the fortuitous discovery of space-occupying lesions of the liver, first consideration should be given to focal fatty sparing, simple hepatic cysts and hemangiomas. The finding of a FNH or an adenoma is rarely a random discovery.

International guidelines for contrast-enhanced ultrasonography: ultrasound imaging in the new millennium

The intent of this review is to discuss and comment on common clinical scenarios in which contrast-enhanced ultrasonography (CEUS) may play a decisive role and to illustrate important points with typical cases. With the advent of CEUS, the scope of indications for ultrasonography has been dramatically extended, and now includes functional imaging and tissue characterization, which in many cases enable tumor diagnosis without a biopsy. It is virtually impossible to imagine the practice of modern medicine as we know it in high-income countries without the use of imaging, and yet, an estimated two thirds of the global population may receive no such care. Ultrasound imaging with CEUS has the potential to correct this inequity.

[Modern diagnostics of cystic liver lesions and hemangiomas]

CLINICAL ISSUE

Cystic liver lesions incorporate a broad heterogeneous group of mostly benign but also malignant abnormalities. The radiological aim is the non-invasive diagnosis with the use of different imaging modalities to determine the type of lesion.

STANDARD RADIOLOGICAL METHODS

The common generally asymptomatic incidental findings of cystic lesions on ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) must be classified on the basis of specific imaging features. Such a differentiation is essential because the clinical consequences and the appropriate therapy can vary depending on the underlying pathology. Due to the morphological overlap of many cystic lesions, conventional radiological methods are often insufficient.

METHODICAL INNOVATIONS

The huge advances in cross-sectional imaging (multidetector CT, MRI with special sequences and different contrast agents and MR cholangiopancreatography) in combination with the clinical history usually enable a non-invasive diagnosis. Pathognomonic morphological and hemodynamic lesion features, as well as a knowledge of the pathomechanisms, help to differentiate this broad spectrum of entities.

ACHIEVEMENTS

In this article the different entities of cystic liver lesions, together with the appropriate diagnostic method for detection and distinction and including their strengths and limitations, are demonstrated.

PRACTICAL RECOMMENDATIONS

A well-founded knowledge about the development of various cystic liver lesions and the suitable choice of imaging method facilitate a non-invasive diagnosis.

Imaging liver lesions using grating-based phase-contrast computed tomography with bi-lateral filter post-processing

X-ray phase-contrast imaging shows improved soft-tissue contrast compared to standard absorption-based X-ray imaging. Especially the grating-based method seems to be one promising candidate for clinical implementation due to its extendibility to standard laboratory X-ray sources. Therefore the purpose of our study was to evaluate the potential of grating-based phase-contrast computed tomography in combination with a novel bi-lateral denoising method for imaging of focal liver lesions in an ex vivo feasibility study. Our study shows that grating-based phase-contrast CT (PCCT) significantly increases the soft-tissue contrast in the ex vivo liver specimens. Combining the information of both signals – absorption and phase-contrast – the bi-lateral filtering leads to an improvement of lesion detectability and higher contrast-to-noise ratios. The normal and the pathological tissue can be clearly delineated and even internal structures of the pathological tissue can be visualized, being invisible in the absorption-based CT alone. Histopathology confirmed the presence of the corresponding findings in the analyzed tissue. The results give strong evidence for a sufficiently high contrast for different liver lesions using non-contrast-enhanced PCCT. Thus, ex vivo imaging of liver lesions is possible with a polychromatic X-ray source and at a spatial resolution of ∼100 µm. The post-processing with the novel bi-lateral denoising method improves the image quality by combining the information from the absorption and the phase-contrast images.

[Benign focal hepatic lesions]

A profound knowledge of the various benign focal hepatic lesions and selection of the most suitable radiological examination modality is essential for achieving an accurate characterization of a hepatic lesion and in turn will determine the further patient management. This will avoid unnecessary agitation to both patient and the referring clinician and limits time-consuming, costly and risky biopsies to an absolute minimum. The following article will discuss the typical and atypical appearances of the most frequent and clinically relevant benign focal hepatic lesions with ultrasound, computed tomography and magnetic resonance imaging.

Incidental findings in imaging diagnostic tests: a systematic review

The objective of this review is to summarise the available evidence on the frequency and management of incidental findings in imaging diagnostic tests. Original articles were identified by a systematic search of the MEDLINE, EMBASE and Cochrane Library Plus databases using appropriate medical headings. Extracted variables were study design; sample size; type of imaging test; initial diagnosis; frequency and location of incidental findings; whether clinical follow-up was performed; and whether a definitive diagnosis was made. Study characteristics were assessed by one reviewer and checked by a second reviewer. Any disagreement was solved by consensus. The relationship between the frequency of incidental findings and the study characteristics was assessed using a one-way ANOVA test, as was the frequency of follow-up of incidental findings and the frequency of confirmation. 251 potentially relevant abstracts were identified and 44 articles were finally included in the review. Overall, the mean frequency of incidental findings was 23.6% (95% confidence interval (CI) 15.8-31.3%). The frequency of incidental findings was higher in studies involving CT technology (mean 31.1%, 95% CI 20.1-41.9%), in patients with an unspecific initial diagnosis (mean 30.5, 95% CI 0-81.6) and when the location of the incidental findings was unspecified (mean 33.9%, 95% CI 18.1-49.7). The mean frequency of clinical follow-up was 64.5% (95% CI 52.9-76.1%) and mean frequency of clinical confirmation was 45.6% (95% CI 32.1-59.2%). Although the optimal strategy for the management of these abnormalities is still unclear, it is essential to be aware of the low clinical confirmation in findings of moderate and major importance.

Abdominal visceral findings in patients with Marfan syndrome

PURPOSE

Marfan syndrome is an autosomal dominant disorder historically defined by well-characterized features in the cardiovascular, ocular, and skeletal systems. To date, there have been no reports concerning abdominal visceral findings in this disorder. The purpose of this study was to determine the prevalence of abdominal visceral findings in patients with Marfan syndrome.

METHODS

Computed tomography or magnetic resonance studies of 69 patients with Marfan syndrome and an age- and sex-matched cohort of control subjects were reviewed. The presence of abdominal visceral findings was noted. Chi-square and Student t tests were used to determine significance of differences between the patient and control groups. This retrospective study was approved by the local institutional review board and determined to be exempt from Health Insurance Portability and Accountability Act reporting requirements.

RESULTS

Renal cysts were present in 41 Marfan patients (59.4%) versus 21 control subjects (30.4%), P=0.001. The average number of renal cysts was greater in Marfan patients than controls (2.4 vs. 0.9, P=0.005). Hepatic cysts were present in 24 Marfan patients (34.8%) versus 12 control patients (17.3%), P=0.02. The average number of hepatic cysts was also greater in Marfan patients than controls (0.9 vs. 0.3, P=0.027). Cholelithiasis was present in 12 Marfan patients (18.1%) versus one control patient (1.5%), P<0.001.

CONCLUSIONS

Marfan syndrome patients have liver and renal cysts more often, in increased number, and at an earlier age than controls, in addition to an increased prevalence of cholelithiasis. Further study will be needed to relate these findings to recent developments concerning the underlying molecular genetics of this disorder.

Liver haemangioma: common and uncommon findings and how to improve the differential diagnosis

Haemangiomas are common focal liver lesions, generally detected in the work-up of asymptomatic patients. From the pathological point of view, they can be classified as small (capillary) or large, with cavernous vascular spaces that may show thrombosis, calcifications and hyalinisation. The polymorphic imaging appearance of haemangiomas depends on their histological features and flow pattern. The widespread use of cross-sectional imaging has allowed an increased detection rate and a better characterisation of this benign tumour. Recent developments of ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) providing high spatial and temporal resolution, together with the use of new contrast agents and/or pulse sequences has broadened the spectrum of imaging findings, contributing to diagnostic refinement in difficult cases. The scope of the present article is to provide an overview of the range of appearances of haemangiomas, explored with recent cross-sectional imaging modalities, emphasising its atypical findings as explored by temporally resolved contrast-enhanced imaging.

THREE-DIMENSIONAL HELICAL COMPUTED TOMOGRAPHIC ANGIOGRAPHY OF THE LIVER IN FIVE DOGS

The objective of this study was to develop a simple, safe, minimally invasive protocol to evaluate the hepatic vasculature. Five purpose-bred Beagle dogs underwent noncontrast-enhanced computed tomographic scan of the entire abdomen. A dynamic, nonincremental computed tomography scan at the level of T11 was then performed using a test bolus of contrast medium to determine time to peak opacification and to aid in the calculation of scan delay. The time to peak arterial enhancement ranged from 2.0 to 7.0 s, with a median of 2.0 s. The time to peak portal venous enhancement ranged from 23.0 to 46.0 s, with a median of 32.0 s. Scan delay for arterial opacification ranged from 0 to 5.0 s, with a median of 0 s. Scan delay for the portal phase of opacification ranged from 6.0 to 21.0 s, with a median of 17.0 s. Using this information, two separate computed tomographic studies were used to image the arterial and portal venous phases of circulatory opacification, respectively. The dogs were hyperventilated to prevent breathing motion during the scan, each of which required approximately 20 s. A power injector was used to inject diatrizoate meglumine (128 mg I/kg) through an 18-gauge cephalic vein catheter at a rate of 5 ml/s. Scanning was initiated after the appropriate scan delay to optimize the specific phase of vascular filling. Maximum intensity projections allowed clear delineation of the hepatic arteries and the portal venous system, while eliminating overlying structures that might interfere with image analysis. Time/density curves were generated, and the time needed for each study was recorded. Hepatic arteries and portal veins were clearly visualized in all dogs. Parenchymal opacification was also observed.

Hepatic resection for incidentaloma

The study goal was to review a single-center experience in hepatic resection for patients who presented with incidental liver tumors. With recent advances in diagnostic imaging techniques, incidental finding of liver tumors, or "incidentalomas," is increasing in asymptomatic and healthy individuals. However, little information is available in the literature regarding the underlying pathology and operative outcomes after hepatic resection. Between January 1989 and December 2002, 1011 patients underwent hepatic resection for liver tumors; of these patients, 107 (11%) were asymptomatic individuals who presented with incidentalomas. Incidentalomas were first detected on percutaneous ultrasonography (n = 83), computed tomography (n = 23), or magnetic resonance imaging (n = 1). Fifteen (14%) patients had preoperative aspiration for cytology or biopsy for histology, and the results correlated with the final pathology in 12 patients. Fifty-six (52%) patients underwent major hepatic resection with resection of three or more Coiunaud's segments. Median postoperative hospital stay was 8 days (range, 3-66 days). The operative mortality rate was 1%, and the operative morbidity rate was 21%. Histologic examination of the resected specimen revealed malignant liver tumors in 62 (58%) patients, including hepatocellular carcinoma (HCC) (n = 48), cholangiocarcinoma (n = 8), lymphoma (n = 2), cystadenocarcinoma (n = 2), carcinoid tumor (n = 1), and malignant fibrous histiocytoma (n = 1). Benign pathologies were found in 45 (42%) patients, including focal nodular hyperplasia (n = 17), hemangioma (n = 12), angiomyolipoma (n = 5), cirrhotic regenerative nodule (n = 4), hepatic adenoma (n = 2), and others (n = 5). On multivariate analysis, male sex, age of greater than 50 years, and tumor size of greater than 4 cm were the independent predictive factors for malignant diseases. On retrospective analysis, 48 patients with HCC who presented with incidentalomas had significantly better survival outcomes after hepatic resection than did 646 patients with HCC who presented otherwise during the same study period. Hepatic resection for patients with incidentalomas is associated with a low operative mortality and acceptable morbidity. The diagnosis of malignant disease, especially HCC, should be considered in male patients older than 50 years who present with large hepatic lesions.