Fatty Liver: Imaging Patterns and Pitfalls

Prevalence and Predictive Features of CT-Derived Nonalcoholic Fatty Liver Disease in Metabolically Healthy MACS

OBJECTIVE

Patients with mild autonomous cortisol secretion (MACS) are at increased risk of cardiometabolic outcomes, such as hyperglycemia, metabolic syndrome, and cardiovascular diseases. Nonalcoholic fatty liver disease (NAFLD) is also associated with increased cardiometabolic risk. We aimed to investigate the prevalence and predictors of NAFLD in metabolically healthy subjects with MACS.

METHODS

Forty patients with MACS and 60 patients with nonfunctioning adrenal incidentaloma (NFAI) matched for age, gender, and body mass index were included. We excluded various diseases that may lead to NAFLD, such as diabetes, cardiovascular diseases, and liver disorders. Non-alcoholic fatty liver disease was evaluated with unenhanced abdominal computed tomography and noninvasive fatty liver indices.

RESULTS

Patients with MACS had lower mean liver attenuation values (Hounsfield units, HU) than those with NFAI (p = 0.001). Visceral adiposity index, hepatic steatosis index, and fatty liver index were higher in the MACS group than in the NFAI group (p = 0.009, p = 0.002, p = 0.023, respectively). However, there was no significant association between the mean liver HU value and these indices. There was a significant association between serum cortisol level after the 1 mg dexamethasone suppression test (DST) and mean liver HU value independent of other traditional risk factors in various models performed in multivariable linear regression analysis.

CONCLUSIONS

Our findings suggest that MACS is associated with an increased risk of NAFLD, and serum cortisol level after 1 mg DST is an independent predictor of NAFLD in patients with MACS.

Documentation of incidentally noted hepatic steatosis to emergency department patients: A retrospective study

BACKGROUND

Hepatic steatosis is a common incidental finding on emergency department (ED) imaging studies, occurring in up to 10% of studies, and carries significant long-term morbidity. Frequently considered an unimportant finding, it is unknown how often ED patients are informed of hepatic steatosis. Our objective was to examine hepatic steatosis inclusion in ED discharge materials.

METHODS

Data from discharged patients at an urban academic ED (>90,000 visits) with abdominal imaging (computed tomography or ultrasound) from 2019 to 2022 were screened. Patients with radiology reports documenting hepatic steatosis were included. Two trained data abstractors analyzed discharge materials and coded disclosure of steatosis (present/absent). Data abstraction also noted how the finding was included (e.g., follow-up instructions, provision of radiology report). Factors associated with patient disclosure were examined through regression models including age, race, ethnicity, insurance, number of imaging studies during encounter, type of imaging study, and inclusion of hepatic steatosis in the impression section of radiology report.

RESULTS

Of 10,677 radiology reports, 1209 (11.3%) had documented hepatic steatosis. The mean (±SD) age was 47.1 (±14.1) years; 56.4% were female, 53.5% were White, and 30.7% Hispanic. Only 173 of 1209 patients (14.3%) received any discharge documentation of hepatic steatosis. In 65% of cases where disclosure occurred, the imaging report was pasted verbatim into discharge material. There were no significant differences in discharge documentation by demographic groups. Mention within the radiology report impression (rather than the report body alone) occurred in 73.8% of records and was the strongest predictor of disclosure to patients (adjusted odds ratio 2.18, 95% confidence interval 1.39-3.54).

CONCLUSIONS

Despite the high prevalence of hepatic steatosis in radiology reports, rates of documentation in patient-facing discharge materials are notably low, exposing a possible communication failure with consequences for diagnosis.

New-onset hepatic lesions in oncological patients: A challenging diagnosis

The appearance of new-onset liver lesions is frequent during imaging follow-up of oncological patients. Most of these lesions will be metastases. But in the presence of atypical radiological findings, there are other diagnoses to consider. Hepatic abscesses, focal nodular hyperplasia-like in patients treated with platinum salts, or hepatocarcinoma in cirrhotic patients are examples of lesions that may appear in the imaging follow-up and should not be confused with metastases. It is essential to establish the nature of the lesion as this will determine the therapeutic management and might avoid unnecessary invasive procedures. The evaluation of previous radiological studies and the global vision of the patient will be primordial. While liver MRI is mainly the indicated imaging technique for these cases, sometimes a biopsy will be unavoidable. In this article, we will discuss through clinical cases some new-onset liver lesions in oncological patients that generated diagnostic doubts and will explain how to orient the diagnosis.

Prevalence, risk factors and association with gallstone disease of non-alcoholic fatty liver disease among rural indigenous communities: A cross-sectional study in Sarawak, Malaysia

Introduction

This study aimed to evaluate the prevalence and risk factors of non-alcoholic fatty liver disease (NAFLD) among Dayak communities in Malaysia, shedding light on an underexplored population.

Methods

A cross-sectional study was undertaken among Dayak villagers in Sarawak aged 18 years and above using an interview-based questionnaire, followed by an anthropometric measurement, a blood test and an abdominal ultrasound.

Results

A total of 324 participants met the inclusion criteria. Among them, 42.9% were men, and the mean age was 49.85±14.9 years. The prevalence of NAFLD was substantially high at 58%, with 43.1% of the participants having mild fatty liver (grade 1). NAFLD was closely associated with waist circumference and body mass index (BMI) (P<0.001). Central obesity, as indicated by waist circumference and BMI, emerged as a potent risk factor, with higher values correlating with an increased likelihood of NAFLD. A higher prevalence of NAFLD was observed in the participants with an advancing age, an elevated triglyceride level (66.7%) and a lower high-density lipoprotein cholesterol level (81.6%). However, these associations did not remain significant in the multivariate analysis. Gallstones, which share common risk factors with NAFLD, were not significantly associated with NAFLD in this population (P=0.853).

Conclusion

This study defines the prevalence and association of NAFLD with sociodemographic characteristics, health profiles and gallstone disease among indigenous villages in Dayak communities. A high BMI and central obesity are found to be independent risk factors of NAFLD.

A Cloud-Based System for Automated AI Image Analysis and Reporting

Although numerous AI algorithms have been published, the relatively small number of algorithms used clinically is partly due to the difficulty of implementing AI seamlessly into the clinical workflow for radiologists and for their healthcare enterprise. The authors developed an AI orchestrator to facilitate the deployment and use of AI tools in a large multi-site university healthcare system and used it to conduct opportunistic screening for hepatic steatosis. During the 60-day study period, 991 abdominal CTs were processed at multiple different physical locations with an average turnaround time of 2.8 min. Quality control images and AI results were fully integrated into the existing clinical workflow. All input into and output from the server was in standardized data formats. The authors describe the methodology in detail; this framework can be adapted to integrate any clinical AI algorithm.

Automated Integration of AI Results into Radiology Reports Using Common Data Elements

Integration of artificial intelligence (AI) into radiology practice can create opportunities to improve diagnostic accuracy, workflow efficiency, and patient outcomes. Integration demands the ability to seamlessly incorporate AI-derived measurements into radiology reports. Common data elements (CDEs) define standardized, interoperable units of information. This article describes the application of CDEs as a standardized framework to embed AI-derived results into radiology reports. The authors defined a set of CDEs for measurements of the volume and attenuation of the liver and spleen. An AI system segmented the liver and spleen on non-contrast CT images of the abdomen and pelvis, and it recorded their measurements as CDEs using the Digital Imaging and Communications in Medicine Structured Reporting (DICOM-SR) framework to express the corresponding labels and values. The AI system successfully segmented the liver and spleen in non-contrast CT images and generated measurements of organ volume and attenuation. Automated systems extracted corresponding CDE labels and values from the AI-generated data, incorporated CDE values into the radiology report, and transmitted the generated image series to the Picture Archiving and Communication System (PACS) for storage and display. This study demonstrates the use of radiology CDEs in clinical practice to record and transfer AI-generated data. This approach can improve communication among radiologists and referring providers, harmonize data to enable large-scale research efforts, and enhance the performance of decision support systems. CDEs ensure consistency, interoperability, and clarity in reporting AI findings across diverse healthcare systems.

Lean body weight-based contrast injection protocol in liver CT: optimization of contrast medium dose

OBJECTIVES

To evaluate liver enhancement and image quality of abdominal CECT examinations acquired with multiple LBW-based contrast medium injection protocols.

MATERIAL & METHODS

One hundred fifty patients who underwent a clinically indicated CECT examination were prospectively and randomly assigned to one of the following contrast medium injection protocol groups: A, 700 mg iodine(I)/kg of LBW; B, 650 mgI/kg of LBW; and C, 600 mgI/kg of LBW. Liver signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and magnitude of contrast enhancement (ΔHU) were calculated. Subjective image quality was assessed with 5-point Likert scale.

RESULTS

The final population included 145 patients (64 females), with 50, 48, and 47 in group A, B, and C, respectively. Group A showed significantly higher SNR, CNR and ΔHU than group B (p = .018, p = .004, and p = .031, respectively) and group C (p = .024, p = .043, and p = .004). Group B had similar SNR, CNR, and ΔHU to group C (all p = 1). ΔHU was < 50 HU in 2, 7, and 11 patients in group A (48.2 ± 0.1), B (43.7 ± 5), and C (44.4 ± 5), respectively. Group A achieved the highest scores in terms of overall image quality, artifacts, and diagnostic confidence (both scores: 4; IQRs: 4-5) compared to group B (both scores: 3; IQRs: 3-5; p ≥ .037) and group C (overall image quality score: 3; IQR: 2-5; p = .011. Artifact and diagnostic confidence score: 3; IQR: 1-4; p ≥ .009).

CONCLUSIONS

A dosage of 700 mgI/kg of LBW yields optimal liver enhancement and grants higher image quality compared to lower contrast medium dosages.

Correlation between qualitative and semi-quantitative ultrasound assessment of diffuse fatty liver disease: A case-control study

Objective

To study the relationship between qualitative and semi-quantitative assessment of diffuse liver steatosis in ultrasound.

Patients and Methods

This was a case-control study, conducted in the Campus University Hospital Centre of Lome (Togo) over a 3-month period. It included 40 patients showing ultrasonographic signs of diffuse hepatic steatosis and 40 volunteers (healthy) whose echostructure and echogenicity of the hepatic parenchyma were normal. The B-mode sonographic grade of steatosis was compared with the hepatorenal echogenicity gradient and the ultrasound attenuation coefficient.

Results

The average body mass index in patients was 30.87 ± 4.65 kg/m2 versus 24.25 ± 4.30 kg/m2 in the healthy group (p < 0.00001). Hepatomegaly was observed in 57.5% of the patients versus 17.5% in the healthy group (p = 0.0005). The average hepatorenal echogenicity ratio was 1.18 ± 0.07 in patients versus 1.01 ± 0.03 in the healthy group (p < 0.00001). The average difference in hepatorenal echogenicity was 9.30 ± 3.41 dB in patients versus 1.52 ± 1.07 dB in the healthy group (p < 0.00001). The attenuation of ultrasound waves increased with the grade of steatosis, averaging 0.08 ± 0.23 dB/cm/MHz (ranging from -0.33 to 0.61 dB/cm/MHz) in patients versus -0.24 ± 0.21 (ranging from -0.69 to 0.19 dB/cm/MHz) in the healthy group (p < 0.00001).

Conclusion

Despite the advancements in new ultrasound technologies today, qualitative methods continue to be effective for the detection of hepatic steatosis and could prove useful in monitoring the effectiveness of hepatic steatosis treatment.

Validation of a multi-parameter algorithm for personalized contrast injection protocol in liver CT

BACKGROUND

In liver computed tomography (CT), tailoring the contrast injection to the patient's specific characteristics is relevant for optimal imaging and patient safety. We evaluated a novel algorithm engineered for personalized contrast injection to achieve reproducible liver enhancement centered on 50 HU.

METHODS

From September 2020 to August 31, 2022, CT data from consecutive adult patients were prospectively collected at our multicenter premises. Inclusion criteria consisted of an abdominal CT referral for cancer staging or follow-up. For all examinations, a web interface incorporating data from the radiology information system (patient details and examination information) and radiographer-inputted data (patient fat-free mass, imaging center, kVp, contrast agent details, and imaging phase) were used. Calculated contrast volume and injection rate were manually entered into the CT console controlling the injector. Iopamidol 370 mgI/mL or Iohexol 350 mgI/mL were used, and kVp varied (80, 100, or 120) based on patient habitus.

RESULTS

We enrolled 384 patients (mean age 61.2 years, range 21.1-94.5). The amount of administered iodine dose (gI) was not significantly different across contrast agents (p = 0.700), while a significant increase in iodine dose was observed with increasing kVp (p < 0.001) and in males versus females (p < 0.001), as expected. Despite the differences in administered iodine load, image quality was reproducible across patients with 72.1% of the examinations falling within the desirable range of 40-60 HU.

CONCLUSION

This study validated a novel algorithm for personalized contrast injection in adult abdominal CT, achieving consistent liver enhancement centered at 50 HU.

RELEVANCE STATEMENT

In healthcare's ongoing shift towards personalized medicine, the algorithm offers excellent potential to improve diagnostic accuracy and patient management, particularly for the detection and follow-up of liver malignancies.

KEY POINTS

The algorithm achieves reproducible liver enhancement, promising improved diagnostic accuracy and patient management in diverse clinical settings. The real-world study demonstrates this algorithm's adaptability to different variables ensuring high-quality liver imaging. A personalized algorithm optimizes liver CT, improving the visibility, conspicuity, and follow-up of liver lesions.

Distribution of Normative Percentiles of Liver Stiffness Measurement Using Ultrasound Shear Wave Elastography in an Adult Asian Indian Population

Objective  The aim of this study was to determine the normative percentiles for liver stiffness measurement (LSM) using shear wave elastography in an adult Asian Indian population as part of the preventive radiology initiative of the Indian Radiological and Imaging Association (IRIA). Methods  LSMs were ascertained by two-dimensional (2D) shear wave elastography using the Mindray Resona series of ultrasound machines. The image quality was assessed using the motion stability index (M-STB) and reliability (RLB) map. Ten acquisitions were documented, and an interquartile range-to-median (IQR/M) ratio ≤30% kilopascal (kPa) units was considered a good-quality measurement. A subgroup of the study population without comorbidities was chosen to derive the normative percentile distribution of LSM using a generalized least squares multivariable fractional polynomial regression model that adjusted for sex and body mass index (BMI). The effectiveness of the estimated percentiles was assessed on the entire study population using the greater than 90th percentile value of the LSM as the cutoff for abnormality. Results  The study included 852 people who underwent shear wave elastography from June 2022 to July 2023. The magnitude of compensated advanced chronic liver disease (cACLD) and clinically significant portal hypertension (CSPH) was 6.81% (95% confidence interval [CI]: 5.30-8.7) and 4.91% (95% CI: 3.67-6.60), respectively. The normative percentiles were estimated from 282 persons without associated comorbidity and risk factors. The mean age (standard deviation [SD]) of the normal individuals was 40.90 ± 12.92 years, and 210 (71.47%) were males. The mean age (SD) of the 570 persons excluded from the normative percentiles analysis was 47.94 (12.49) years and 72.11% were males. The sex- and BMI-adjusted age-specific 90th percentiles of LSM were 8.76, 8.78, 8.96, 8.97, 9.25, and 9.45 kPa for 18 to 20, 21 to 30, 31 to 40, 41 to 50, 51 to 60, and 61 to 70 years, respectively. Conclusion  The sex- and BMI-adjusted age-specific 90th percentiles for LSM using shear wave elastography in Asian Indian adults are almost similar to the greater than 9 kPa cutoff proposed by the Society of Radiologists in Ultrasound Liver Elastography Consensus Statement guidelines to discriminate cACLD and CSPH from normal individuals.

The reliability of virtual non-contrast reconstructions of photon-counting detector CT scans in assessing abdominal organs

BACKGROUND

Spectral imaging of photon-counting detector CT (PCD-CT) scanners allows for generating virtual non-contrast (VNC) reconstruction. By analyzing 12 abdominal organs, we aimed to test the reliability of VNC reconstructions in preserving HU values compared to real unenhanced CT images.

METHODS

Our study included 34 patients with pancreatic cystic neoplasm (PCN). The VNC reconstructions were generated from unenhanced, arterial, portal, and venous phase PCD-CT scans using the Liver-VNC algorithm. The observed 11 abdominal organs were segmented by the TotalSegmentator algorithm, the PCNs were segmented manually. Average densities were extracted from unenhanced scans (HUunenhanced), postcontrast (HUpostcontrast) scans, and VNC reconstructions (HUVNC). The error was calculated as HUerror=HUVNC-HUunenhanced. Pearson's or Spearman's correlation was used to assess the association. Reproducibility was evaluated by intraclass correlation coefficients (ICC).

RESULTS

Significant differences between HUunenhanced and HUVNC[unenhanced] were found in vertebrae, paraspinal muscles, liver, and spleen. HUVNC[unenhanced] showed a strong correlation with HUunenhanced in all organs except spleen (r = 0.45) and kidneys (r = 0.78 and 0.73). In all postcontrast phases, the HUVNC had strong correlations with HUunenhanced in all organs except the spleen and kidneys. The HUerror had significant correlations with HUunenhanced in the muscles and vertebrae; and with HUpostcontrast in the spleen, vertebrae, and paraspinal muscles in all postcontrast phases. All organs had at least one postcontrast VNC reconstruction that showed good-to-excellent agreement with HUunenhanced during ICC analysis except the vertebrae (ICC: 0.17), paraspinal muscles (ICC: 0.64-0.79), spleen (ICC: 0.21-0.47), and kidneys (ICC: 0.10-0.31).

CONCLUSIONS

VNC reconstructions are reliable in at least one postcontrast phase for most organs, but further improvement is needed before VNC can be utilized to examine the spleen, kidneys, and vertebrae.

Metabolic-associated fatty liver voxel-based quantification on CT images using a contrast adapted automatic tool

BACKGROUND & AIMS

Metabolic-dysfunction associated fatty liver disease (MAFLD) is highly prevalent and can lead to liver complications and comorbidities, with non-invasive tests such as vibration-controlled transient elastography (VCTE) and invasive liver biopsies being used for diagnosis The aim of the present study was to develop a new fully automatized method for quantifying the percentage of fat in the liver based on a voxel analysis on computed tomography (CT) images to solve previously unconcluded diagnostic deficiencies either in contrast (CE) or non-contrast enhanced (NCE) assessments.

METHODS

Liver and spleen were segmented using nn-UNet on CE- and NCE-CT images. Radiodensity values were obtained for both organs for defining the key benchmarks for fatty liver assessment: liver mean, liver-to-spleen ratio, liver-spleen difference, and their average. VCTE was used for validation. A classification task method was developed for detection of suitable patients to fulfill maximum reproducibility across cohorts and highlight subjects with other potential radiodensity-related diseases.

RESULTS

Best accuracy was attained using the average of all proposed benchmarks being the liver-to-spleen ratio highly useful for CE and the liver-to-spleen difference for NCE. The proposed whole-organ automatic segmentation displayed superior potential when compared to the typically used manual region-of-interest drawing as it allows to accurately obtain the percent of fat in liver, among other improvements. Atypical patients were successfully stratified through a function based on biochemical data.

CONCLUSIONS

The developed method tackles the current drawbacks including biopsy invasiveness, and CT-related weaknesses such as lack of automaticity, dependency on contrast agent, no quantification of the percentage of fat in liver, and limited information on region-to-organ affectation. We propose this tool as an alternative for individualized MAFLD evaluation by an early detection of abnormal CT patterns based in radiodensity whilst abording detection of non-suitable patients to avoid unnecessary exposure to CT radiation. Furthermore, this work presents a surrogate aid for assessing fatty liver at a primary assessment of MAFLD using elastography data.

Development and validation of a novel non-invasive test for diagnosing nonalcoholic fatty liver disease in Chinese children

BACKGROUND

With the exploding prevalence of obesity, many children are at risk of developing nonalcoholic fatty liver disease. Using anthropometric and laboratory parameters, our study aimed to develop a model to quantitatively evaluate liver fat content (LFC) in children with obesity.

METHODS

A well-characterized cohort of 181 children between 5 and 16 years of age were recruited to the study in the Endocrinology Department as the derivation cohort. The external validation cohort comprised 77 children. The assessment of liver fat content was performed using proton magnetic resonance spectroscopy. Anthropometry and laboratory metrics were measured in all subjects. B-ultrasound examination was carried out in the external validation cohort. The Kruskal-Wallis test, Spearman bivariate correlation analyses, univariable linear regressions and multivariable linear regression were used to build the optimal predictive model.

RESULTS

The model was based on indicators including alanine aminotransferase, homeostasis model assessment of insulin resistance, triglycerides, waist circumference and Tanner stage. The adjusted R2 of the model was 0.589, which presented high sensitivity and specificity both in internal [sensitivity of 0.824, specificity of 0.900, area under curve (AUC) of 0.900 with a 95% confidence interval: 0.783-1.000] and external validation (sensitivity of 0.918 and specificity of 0.821, AUC of 0.901 with a 95% confidence interval: 0.818-0.984).

CONCLUSIONS

Our model based on five clinical indicators was simple, non-invasive, and inexpensive; it had high sensitivity and specificity in predicting LFC in children. Thus, it may be useful for identifying children with obesity who are at risk for developing nonalcoholic fatty liver disease.

Correlation between magnetic resonance imaging proton density fat fraction (MRI-PDFF) and liver biopsy to assess hepatic steatosis in obesity

Obesity is highly associated with Non-alcoholic fatty liver disease (NAFLD) and increased risk of liver cirrhosis and liver cancer-related death. We determined the diagnostic performance of the complex-based chemical shift technique MRI-PDFF for quantifying liver fat and its correlation with histopathologic findings in an obese population within 24 h before bariatric surgery. This was a prospective, cross-sectional, Institutional Review Board-approved study of PDFF-MRI of the liver and MRI-DIXON image volume before bariatric surgery. Liver tissues were obtained during bariatric surgery. The prevalence of NAFLD in the investigated cohort was as high as 94%. Histologic hepatic steatosis grades 0, 1, 2, and 3 were observed in 3 (6%), 25 (50%), 14 (28%), and 8 (16%) of 50 obese patients, respectively. The mean percentages of MRI-PDFF from the anterior and posterior right hepatic lobe and left lobe vs. isolate left hepatic lobe were 15.6% (standard deviation [SD], 9.28%) vs. 16.29% (SD, 9.25%). There was a strong correlation between the percentage of steatotic hepatocytes and MRI-PDFF in the left hepatic lobe (r = 0.82, p < 0.001) and the mean value (r = 0.78, p < 0.001). There was a strong correlation between MRI-derived subcutaneous adipose tissue volume and total body fat mass by dual-energy X-ray absorptiometry, especially at the L2-3 and L4 level (r = 0.85, p < 0.001). MRI-PDFF showed good performance in assessing hepatic steatosis and was an excellent noninvasive technique for monitoring hepatic steatosis in an obese population.

Multifocal fatty liver nodules mimicking a metastatic disease: A case report

Multifocal fatty liver nodules can present a diagnostic challenge due to their resemblance to metastatic liver disease. This case report illustrates the complexity of such scenarios through the presentation of a middle-aged male patient. Despite the common nature of fatty liver disease, characterized by hepatocyte fat accumulation leading to diffuse and uniform liver lesions, rare instances exhibit heterogeneous appearances. The case underlines the potential confusion arising from imaging modalities when multiple small nodules disperse throughout the liver, mimicking multifocal tumors or metastases. The report emphasizes the critical role of comprehensive diagnostic procedures in preventing misdiagnosis and unwarranted interventions. Effective management hinges on multidisciplinary collaboration among specialists, ensuring accurate differentiation and appropriate treatment. This study serves as a reminder of the intricacies involved in interpreting multifocal fatty liver nodules that may masquerade as metastatic disease, highlighting the need for precision in clinical practice.

Inverse association between total bilirubin and type 2 diabetes in U.S. South Asian males but not females

AIMS

United States South Asians constitute a fast-growing ethnic group with high prevalence of type 2 diabetes (T2D) despite lower mean BMI and other traditional risk factors compared to other races/ethnicities. Bilirubin has gained attention as a potential antioxidant, cardio-protective marker. Hence we sought to determine whether total bilirubin was associated with prevalent and incident T2D in U.S. South Asians.

METHODS

We conducted a cross-sectional and prospective analysis of the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study. Total bilirubin was categorized into gender-specific quartiles (Men: <0.6, 0.6, 0.7-0.8, >0.8; Women: <0.5, 0.5, 0.6, >0.6 mg/dl). We estimated odds of type 2 diabetes as well as other cardiovascular (CV) risk factors using multivariable logistic regression.

RESULTS

Among a total 1,149 participants (48% female, mean [SD] age of 57 [9] years), 38% had metabolic syndrome and 24% had T2D. Men and women in the lowest bilirubin quartile had 0.55% and 0.17% higher HbA1c than the highest quartile. Men, but not women, in the lowest bilirubin quartile had higher odds of T2D compared to the highest quartile (aOR [95% CI]; Men: 3.00 [1.72,5.23], Women: 1.15 [0.57,2.31]). There was no association between bilirubin and other CV risk factors.

CONCLUSION

Total bilirubin was inversely associated with T2D in SA men but not women. Longitudinal studies are needed to understand temporality of association.

Clinical correlates of CT imaging-derived phenotypes among lean and overweight patients with hepatic steatosis

The objective of this study is to define CT imaging derived phenotypes for patients with hepatic steatosis, a common metabolic liver condition, and determine its association with patient data from a medical biobank. There is a need to further characterize hepatic steatosis in lean patients, as its epidemiology may differ from that in overweight patients. A deep learning method determined the spleen-hepatic attenuation difference (SHAD) in Hounsfield Units (HU) on abdominal CT scans as a quantitative measure of hepatic steatosis. The patient cohort was stratified by BMI with a threshold of 25 kg/m2 and hepatic steatosis with threshold SHAD ≥  - 1 HU or liver mean attenuation ≤ 40 HU. Patient characteristics, diagnoses, and laboratory results representing metabolism and liver function were investigated. A phenome-wide association study (PheWAS) was performed for the statistical interaction between SHAD and the binary characteristic LEAN. The cohort contained 8914 patients-lean patients with (N = 278, 3.1%) and without (N = 1867, 20.9%) steatosis, and overweight patients with (N = 1863, 20.9%) and without (N = 4906, 55.0%) steatosis. Among all lean patients, those with steatosis had increased rates of cardiovascular disease (41.7 vs 27.8%), hypertension (86.7 vs 49.8%), and type 2 diabetes mellitus (29.1 vs 15.7%) (all p < 0.0001). Ten phenotypes were significant in the PheWAS, including chronic kidney disease, renal failure, and cardiovascular disease. Hepatic steatosis was found to be associated with cardiovascular, kidney, and metabolic conditions, separate from overweight BMI.

Imaging of Alcohol-Associated Liver Disease

Alcohol-associated liver disease (ALD) continues to be a global health concern, responsible for a significant number of deaths worldwide. Although most individuals who consume alcohol do not develop ALD, heavy drinkers and binge drinkers are at increased risk. Unfortunately, ALD is often undetected until it reaches advanced stages, frequently associated with portal hypertension and hepatocellular carcinoma (HCC). ALD is now the leading indication for liver transplant. The incidence of alcohol-associated hepatitis (AH) surged during the COVID-19 pandemic. Early diagnosis of ALD is therefore important in patient management and determination of prognosis, as abstinence can halt disease progression. The spectrum of ALD includes steatosis, steatohepatitis, and cirrhosis, with steatosis the most common manifestation. Diagnostic techniques including ultrasound, CT, and MRI provide useful information for identifying ALD and excluding other causes of liver dysfunction. Heterogeneous steatosis and transient perfusion changes on CT and MRI in the clinical setting of alcohol-use disorder are diagnostic of severe AH. Elastography techniques are useful for assessing fibrosis and monitoring treatment response. These various imaging modalities are also useful in HCC surveillance and diagnosis. This review discusses the imaging modalities currently used in the evaluation of ALD, highlighting their strengths, limitations, and clinical applications.

Variation in hepatic segmental portal venous pulsed wave Doppler flow distribution in patients with NAFLD: A pilot study

Purpose

To evaluate the segmental variations in portal venous pulsed wave colour Doppler flow velocity in patients with moderate to severe non-alcoholic fatty liver disease in comparison with healthy controls.

Materials and Methods

In this prospective, observational, case-control study, the maximum velocity of all the segmental branches of portal vein were evaluated on colour Doppler in patients with moderate to severe non-alcoholic fatty liver disease, and the values were compared between three groups (1) Healthy controls (n = 30), (2) non-alcoholic fatty liver disease group, that is moderate to severe fatty liver without features of portal hypertension (n = 32) and (3) non-alcoholic steatohepatitis-portal hypertension group, that is those non-alcoholic fatty liver disease patients with features of portal hypertension (n = 13).

Results

Compared to controls, non-alcoholic fatty liver disease group showed a lower velocity in all the eight segments of liver. The ratio of segment 2 to segment 7 peak portal vein maximum velocity was significantly higher in non-alcoholic fatty liver disease (1.03 ± 0.21) compared to controls (0.90 ± 0.17) and even higher in non-alcoholic steatohepatitis-Portal hypertension group (1.83 ± 0.40) with p value of 0.003.

Conclusion

Our study demonstrates the occurrence of flow redistribution occurring in cases of non-alcoholic fatty liver disease patients with the left lobe receiving higher portal venous flow. This flow redistribution was even more pronounced in a subset of non-alcoholic fatty liver disease patients who developed features of portal hypertension.

Administrative coding for non-alcoholic fatty liver disease is accurate in Swedish patients

Background and Aims: Epidemiological studies of non-alcoholic fatty liver disease (NAFLD) frequently use the International Classification of Disease (ICD) codes to identify patients. The validity of such ICD codes in a Swedish setting is unknown. Here, we aimed to validate the administrative code for NAFLD in Sweden.Methods: In total, 150 patients with an ICD-10 code for NAFLD (K76.0) from the Karolinska University Hospital between 1 January 2015 and 3 November 2021 were randomly selected. Patients were classified as true or false positives for NAFLD by medical chart review and the positive predictive value (PPV) for the ICD-10 code corresponding to NAFLD was calculated.Results: The PPV of the ICD-10 code for NAFLD was 0.82 (95% confidence interval [CI] = 0.76-0.89). After exclusion of patients with diagnostic coding for other liver diseases or alcohol abuse disorder (n = 14), the PPV was improved to 0.91 (95% CI 0.87-0.96). The PPV was higher in patients with coding for NAFLD in combination with obesity (0.95, 95%CI = 0.87-1.00) or type 2 diabetes (0.96, 95%CI = 0.89-1.00). However, in false-positive cases, a high alcohol consumption was common and such patients had somewhat higher Fibrosis-4 scores than true-positive patients (1.9 vs 1.3, p = 0.16)Conclusions: The ICD-10 code for NAFLD had a high PPV, that was further improved after exclusion of patients with coding for other liver diseases than NAFLD. This approach should be preferred when performing register-based studies to identify patients with NAFLD in Sweden. Still, residual alcohol-related liver disease might risk confound some findings seen in epidemiological studies which needs to be considered.

Intra-examination agreement between multi-echo gradient echo and confounder-corrected chemical shift-encoded MR sequences for R2* estimation as a biomarker of liver iron content in patients with a wide range of T2*/R2* and proton density fat fraction values

PURPOSE

To investigate the intra-examination agreement between multi-echo gradient echo (MEGE) and confounder-corrected chemical shift-encoded (CSE) sequences for liver T2*/R2* estimations in a wide range of T2*/R2* and proton density fat fraction (PDFF) values. Exploratorily, to search for the T2*/R2* value where the agreement line breaks and examine differences between regions of low and high agreement.

METHODS

Consecutive patients at risk for liver iron overload who underwent MEGE and CSE sequences within the same exam at 1.5 T were retrospectively selected. Regions of interest were drawn in the right and one in the left liver lobes on post-processed images for R2*(sec-1) and PDFF (%) estimation. Agreement between MEGE-R2* and CSE-R2* was evaluated using intra-class correlation coefficient (ICC) and Bland-Altman analysis. 95% confidence intervals (CI) were computed. Segment-and-regression analysis was performed to find the point where the agreement between sequences is interrupted. Regions of low and high agreement were examined using tree-based partitioning analyses.

RESULTS

49 patients were included. Mean MEGE-R2* was 94.2 s-1 (range: 31.0-737.1) and mean CSE-R2* 87.7 (29.7-748.1). Mean CSE-PDFF was 9.12% (0.1-43.3). Agreement was strong for R2* estimations (ICC: 0.992,95%CI 0.987,0.996), but the relation was nonlinear and possibly heteroskedastic. Lower agreement occurred when MEGE-R2* > 235 s-1, with MEGE-R2* values consistently lower than CSE-R2*. Higher agreement was observed when PDFF < 14%.

CONCLUSION

MEGE-R2* and CSE-R2* strongly agree, though at higher iron content, MEGE-R2* is consistently lower than CSE-R2*. In this preliminary dataset, a breaking point for agreement was found at R2* > 235. Lower agreement was observed in patients with moderate to severe liver steatosis.

Comparison of computed tomography and dual-energy X-ray absorptiometry in the evaluation of body composition in patients with obesity

Objective

a) To evaluate the accuracy of the pre-existing equations (based on cm2 provided by CT images), to estimate in kilograms (Kg) the body composition (BC) in patients with obesity (PwO), by comparison with Dual-energy X-ray absorptiometry (DXA). b) To evaluate the accuracy of a new approach (based on both cm2 and Hounsfield Unit parameters provided by CT images), using an automatic software and artificial intelligence to estimate the BC in PwO, by comparison with DXA.

Methods

Single-centre cross-sectional study including consecutive PwO, matched by gender with subjects with normal BMI. All the subjects underwent BC assessment by Dual-energy X-ray absorptiometry (DXA) and skeletal-CT at L3 vertebrae. CT images were processed using FocusedON-BC software. Three different models were tested. Model 1 and 2, based on the already existing equations, estimate the BC in Kg based on the tissue area (cm2) in the CT images. Model 3, developed in this study, includes as additional variables, the tissue percentage and its average Hounsfield unit.

Results

70 subjects (46 PwO and 24 with normal BMI) were recruited. Significant correlations for BC were obtained between the three models and DXA. Model 3 showed the strongest correlation with DXA (r= 0.926, CI95% [0.835-0.968], p<0.001) as well as the best agreement based on Bland - Altman plots.

Conclusion

This is the first study showing that the BC assessment based on skeletal CT images analyzed by automatic software coupled with artificial intelligence, is accurate in PwO, by comparison with DXA. Furthermore, we propose a new equation that estimates both the tissue quantity and quality, that showed higher accuracy compared with those currently used, both in PwO and subjects with normal BMI.

Imaging of metabolic and overload disorders in tissues and organs

Metabolic and overload disorders are a heterogeneous group of relatively uncommon but important diseases. While imaging plays a key role in the early detection and accurate diagnosis in specific organs with a pivotal role in several metabolic pathways, most of these diseases affect different tissues as part of a systemic syndromes. Moreover, since the symptoms are often vague and phenotypes similar, imaging alterations can present as incidental findings, which must be recognized and interpreted in the light of further biochemical and histological investigations. Among imaging modalities, MRI allows, thanks to its multiparametric properties, to obtain numerous information on tissue composition, but many metabolic and accumulation alterations require a multimodal evaluation, possibly using advanced imaging techniques and sequences, not only for the detection but also for accurate characterization and quantification. The purpose of this review is to describe the different alterations resulting from metabolic and overload pathologies in organs and tissues throughout the body, with particular reference to imaging findings.

Distinguishing Autoimmune Hepatitis From Steatohepatitis in Adolescents With Obesity and Positive Screening Alanine Aminotransferase

Screening children with obesity for nonalcoholic fatty liver disease leads to identification of elevated alanine aminotransferase (ALT) and is a common cause for referral to pediatric gastroenterology. Guidelines recommend that children with positive screening ALT be evaluated for causes of ALT elevation beyond nonalcoholic fatty liver disease. One clinical challenge is that autoantibodies can be present in patients with obesity and thus may or may not represent autoimmune hepatitis. This case series highlights the importance of a comprehensive evaluation to reach an accurate diagnosis.

Incidental Findings in Pediatric Patients: How to Manage Liver Incidentaloma in Pediatric Patients

The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications entitled "Incidental imaging findings-the role of ultrasound". IFs in the liver of newborns and children are rare and much less commonly encountered than in adults; as a result, they are relatively much more frequently malignant and life-threatening, even when they are of benign histology. Conventional B-mode ultrasound is the well-established first line imaging modality for the assessment of liver pathology in pediatric patients. US technological advances, resulting in image quality improvement, contrast-enhanced ultrasound (CEUS), liver elastography and quantification tools for steatosis have expanded the use of ultrasound technology in daily practice. The following overview is intended to illustrate incidentally detected liver pathology covering all pediatric ages. It aims to aid the examiner in establishing the final diagnosis. Management of incidentally detected focal liver lesions (FLL) needs to take into account the diagnostic accuracy of each imaging modality, the patient's safety issues (including ionizing radiation and nephrotoxic contrast agents), the delay in diagnosis, the psychological burden on the patient and the cost for the healthcare system. Moreover, this paper should help the pediatric clinician and ultrasound practitioner to decide which pathologies need no further investigation, which ones require interval imaging and which cases require further and immediate diagnostic procedures.

Artificial intelligence-powered software detected more than half of the liver metastases overlooked by radiologists on contrast-enhanced CT

PURPOSE

To evaluate the sensitivity of artificial intelligence (AI)-powered software in detecting liver metastases, especially those overlooked by radiologists.

METHODS

Records of 746 patients diagnosed with liver metastases (November 2010-September 2017) were reviewed. Images from when radiologists first diagnosed liver metastases were reviewed, and prior contrast-enhanced CT (CECT) images were checked for availability. Two abdominal radiologists classified the lesions into overlooked lesions (all metastases missed by radiologists on prior CECT) and detected lesions (all metastases if any of them were correctly identified and invisible on prior CECT or those with no prior CECT). Finally, images from 137 patients were identified, 68 of which were classified as "overlooked cases." The same radiologists created the ground truth for these lesions and compared them with the software's output at 2-month intervals. The primary endpoint was the sensitivity in detecting all liver lesion types, liver metastases, and liver metastases overlooked by radiologists.

RESULTS

The software successfully processed images from 135 patients. The per-lesion sensitivity for all liver lesion types, liver metastases, and liver metastases overlooked by radiologists was 70.1%, 70.8%, and 55.0%, respectively. The software detected liver metastases in 92.7% and 53.7% of patients in detected and overlooked cases, respectively. The average number of false positives was 0.48 per patient.

CONCLUSION

The AI-powered software detected more than half of liver metastases overlooked by radiologists while maintaining a relatively low number of false positives. Our results suggest the potential of AI-powered software in reducing the frequency of overlooked liver metastases when used in conjunction with the radiologists' clinical interpretation.

Multifocal nodular lesions in fatty liver mimicking neoplastic disease: a case report

Usually, fatty hepatic infiltration is diffuse and homogeneous. However, in some cases, it can be localized simulating benign or malignant tumors. We present a case of a 61-year-old female patient with family history of malignancy: sister with lung cancer, an other sister with colon cancer and a mother with breast cancer; who presented with multiple hepatic nodules at the ultrasonography images. CT scan and MRI were not sufficient to pose a certain diagnosis which was later confirmed by liver biopsy.

Correlation Between Computed Tomography Findings and the Laboratory Test-Derived Severity Score in Patients With Severe Acute Alcoholic Hepatitis

OBJECTIVE

This study aimed to compare computed tomography (CT) findings between patients with severe and nonsevere acute alcoholic hepatitis (AAH).

METHODS

We included 96 patients diagnosed with AAH between January 2011 and October 2021 who underwent 4-phase liver CT and laboratory blood tests. Two radiologists reviewed the initial CT images with respect to distribution and grade of hepatic steatosis; transient parenchymal arterial enhancement (TPAE); and presence of cirrhosis, ascites, and hepatosplenomegaly. A Maddrey discriminant function score (4.6 × [patient's prothrombin time - control] + total bilirubin [mg/mL]) was used as cutoff indicator for severity, with a score of 32 or higher indicating severe disease. The image findings were compared between the severe (n = 24) and nonsevere (n = 72) groups using the χ2 test or Fisher exact test. After univariate analysis, the most significant factor was identified using a logistic regression analysis.

RESULTS

In the univariate analysis, there were significant between-group differences in the TPAE, liver cirrhosis, splenomegaly, and ascites (P < 0.0001, P < 0.0001, P = 0.0002, and P = 0.0163, respectively). Among them, TPAE was the only significant factor for severe AAH (P < 0.0001; odds ratio, 48.1; 95% confidence interval, 8.3-280.6). Using this single indicator, the estimated accuracy, positive predictive, and negative predictive values were 86%, 67%, and 97%, respectively.

CONCLUSIONS

Transient parenchymal arterial enhancement was the only significant CT finding in severe AAH.

Novel measures for the diagnosis of hepatic steatosis using contrast-enhanced computer tomography images

PURPOSE

Hepatic steatosis is often diagnosed non-invasively. Various measures and accompanying diagnostic thresholds based on contrast-enhanced CT and virtual non-contrast images have been proposed. We compare these established criteria to novel and fully automated measures.

METHOD

CT data sets of 197 patients were analyzed. Regions of interest (ROIs) were manually drawn for the liver, spleen, portal vein, and aorta to calculate four established measures of liver-fat. Two novel measures capturing the deviation between the empirical distributions of HU measurements across all voxels within the liver and spleen were calculated. These measures were calculated with both manual ROIs and using fully automated organ segmentations. Agreement between the different measures was evaluated using correlational analysis, as well as their ability to discriminate between fatty and healthy liver.

RESULTS

Established and novel measures of fatty liver were at a high level of agreement. Novel methods were statistically indistinguishable from the established ones when taking established diagnostic thresholds or physicians' diagnoses as ground truth and this high performance level persisted for automatically selected ROIs.

CONCLUSION

Automatically generated organ segmentations led to comparable results as manual ROIs, suggesting that the implementation of automated methods can prove to be a valuable tool for incidental diagnosis. Differences in the distribution of HU measurements across voxels between liver and spleen can serve as surrogate markers for the liver-fat-content. Novel measures do not exhibit a measurable disadvantage over established methods based on simpler measures such as across-voxel averages in a population with low incidence of fatty liver.

18F-FDG gallbladder uptake: observation from a total-body PET/CT scanner

BACKGROUND

Total-body positron emission tomography/computed tomography (PET/CT) scanners are characterized by higher signal collection efficiency and greater spatial resolution compared to conventional scanners, allowing for delayed imaging and improved image quality. These advantages may also lead to better detection of physiological processes that diagnostic imaging professionals should be aware of. The gallbladder (GB) is not usually visualized as an ¹⁸F-2-fluorodeoxyglucose (¹⁸F-FDG)-avid structure in routine clinical PET/CT studies; however, with the total-body PET/CT, we have been increasingly visualizing GB activity without it being involved in an inflammatory or neoplastic process. The aim of this study was to report visualization rates and characteristics of GB ¹⁸F-FDG uptake observed in both healthy and oncological subjects scanned on a total-body PET/CT system.

MATERIALS AND METHODS

Scans from 73 participants (48 healthy and 25 with newly diagnosed lymphoma) who underwent ¹⁸F-FDG total-body PET/CT were retrospectively reviewed. Subjects were scanned at multiple timepoints up to 3 h post-injection. Gallbladder ¹⁸F-FDG activity was graded using liver uptake as a reference, and the pattern was qualified as present in the wall, lumen, or both. Participants' characteristics, such as age, sex, body-mass index, blood glucose, and other clinical parameters, were collected to assess for any significant correlation with GB ¹⁸F-FDG uptake.

RESULTS

All 73 subjects showed GB uptake at one or more imaging timepoints. An increase in uptake intensity overtime was observed up until the 180-min scan, and the visualization rate of GB ¹⁸F-FDG uptake was 100% in the 120- and 180-min post-injection scans. GB wall uptake was detected in a significant number of patients (44/73, 60%), especially at early timepoint scans, whereas luminal activity was detected in 71/73 (97%) subjects, especially at later timepoint scans. No significant correlation was found between GB uptake intensity/pattern and subjects' characteristics.

CONCLUSION

The consistent observation of GB ¹⁸F-FDG uptake recorded in this study in healthy participants and subjects with a new oncological diagnosis indicates that this is a normal physiologic finding rather than representing an exception.

Regularized Ultrasound Phantom-Free Local Attenuation Coefficient Slope (ACS) Imaging in Homogeneous and Heterogeneous Tissues

Attenuation maps or measurements based on the local attenuation coefficient slope (ACS) in quantitative ultrasound (QUS) have shown potential for the diagnosis of liver steatosis. In liver cancers, tissue abnormalities and tumors detected using ACS are also of interest to provide new image contrast to clinicians. Current phantom-based approaches have the limitation of assuming a comparable speed of sound between the reference phantom and insonified tissues. Moreover, these methods present the inconvenience for operators to acquire data on phantoms and patients. The main goal was to alleviate these drawbacks by proposing a methodology for constructing phantom-free regularized (PF-R) local ACS maps and investigate the performance in both homogeneous and heterogeneous media. The proposed method was tested on two tissue-mimicking media with different ACS constructed as homogeneous phantoms, side-by-side and top-to-bottom phantoms, and inclusion phantoms with different attenuations. Moreover, an in vivo proof-of-concept was performed on healthy, steatotic, and cancerous human liver datasets. Modifications brought to previous works include: 1) a linear interpolation of the power spectrum in the log scale; 2) the relaxation of the underlying hypothesis on the diffraction factor; 3) a generalization to nonhomogeneous local ACS; and 4) an adaptive restriction of frequencies to a more reliable range than the usable frequency range. Regularization was formulated as a generalized least absolute shrinkage and selection operator (LASSO), and a variant of the Bayesian information criterion (BIC) was applied to estimate the Lagrangian multiplier on the LASSO constraint. In addition, we evaluated the proposed algorithm when applying median filtering before and after regularization. Tests conducted showed that the PF-R yielded robust results in all tested conditions, suggesting potential for additional validation as a diagnosis method.

Pulse-Echo Quantitative US Biomarkers for Liver Steatosis: Toward Technical Standardization

Excessive liver fat (steatosis) is now the most common cause of chronic liver disease worldwide and is an independent risk factor for cirrhosis and associated complications. Accurate and clinically useful diagnosis, risk stratification, prognostication, and therapy monitoring require accurate and reliable biomarker measurement at acceptable cost. This article describes a joint effort by the American Institute of Ultrasound in Medicine (AIUM) and the RSNA Quantitative Imaging Biomarkers Alliance (QIBA) to develop standards for clinical and technical validation of quantitative biomarkers for liver steatosis. The AIUM Liver Fat Quantification Task Force provides clinical guidance, while the RSNA QIBA Pulse-Echo Quantitative Ultrasound Biomarker Committee develops methods to measure biomarkers and reduce biomarker variability. In this article, the authors present the clinical need for quantitative imaging biomarkers of liver steatosis, review the current state of various imaging modalities, and describe the technical state of the art for three key liver steatosis pulse-echo quantitative US biomarkers: attenuation coefficient, backscatter coefficient, and speed of sound. Lastly, a perspective on current challenges and recommendations for clinical translation for each biomarker is offered.

Hepatic steatosis with mass effect: A case report

BACKGROUND

Hepatic steatosis is a common radiologic finding. Some imaging inklings are the absence of a mass effect, and there is currently no report of hepatic steatosis with mass effect.

CASE SUMMARY

A 23-year-old female was admitted due to a liver mass for half a month. No obvious abnormalities were found in physical and laboratory examinations. Ultrasound, computed tomography, and magnetic resonance imaging showed a huge mass between the liver and stomach with a significant mass effect, and the caudate lobe and left lobe of the liver were involved. The signal on T2- and T1- weighted fat-saturated images of the mass was significantly reduced, and the enhanced scan showed inhomogeneous enhancement. Surgical and pathological findings indicated the diagnosis of hepatic steatosis. The operation and re-review of the patient's images showed that the lesion was supplied by the branch of the hepatic artery. The signal on T1-weighted out-of-phase images of the lesion was lower than on in-phase images, and there was no black rim cancellation artifact around the hepatic steatosis area on T1-weighted out-of-phase images. The dynamic enhancement pattern of the lesion was similar to that of the adjacent normal liver parenchyma. The above characteristics suggested that the lesion was hepatic steatosis. However, in this case, the lesion showed exogenous growth and was mass-like, with an obvious mass effect, which has not been reported previously.

CONCLUSION

Hepatic steatosis could grow exogenously and has an obvious mass effect. It needs to be distinguished from fat-rich tumors. The T1-weighted in- and out-of-phase images and dynamic enhanced scanning are valuable for differential diagnosis of this lesion.

Tc-99m Sulfur Colloid Scintigraphy in Differentiating Fat Sparing from Lymphomatous Involvement of Liver-Old Wine in New Bottle

Hepatic mass lesions and focal fat sparing in a fatty liver may be difficult to differentiate on contrast-enhanced computed tomography (CT) imaging and F-18-fluorodeoxyglucose positron emission tomography/CT. Tc-99m Sulfur colloid (SC) scintigraphy has been used in the assessment of solid hepatic masses. Liver metastases will appear as focal photopenic defects due to the loss of Kupffer cell function. However, focal fatty infiltration or fat sparing of the liver does not affect Kupffer cell function and thereby leading to normal tracer uptake. Despite several advances in imaging modalities, Tc-99m SC scintigraphy is still a reliable armamentarium in the characterization of hepatic mass lesions.

A flexible three-dimensional heterophase computed tomography hepatocellular carcinoma detection algorithm for generalizable and practical screening

Hepatocellular carcinoma (HCC) can be potentially discovered from abdominal computed tomography (CT) studies under varied clinical scenarios (e.g., fully dynamic contrast-enhanced [DCE] studies, noncontrast [NC] plus venous phase [VP] abdominal studies, or NC-only studies). Each scenario presents its own clinical challenges that could benefit from computer-aided detection (CADe) tools. We investigate whether a single CADe model can be made flexible enough to handle different contrast protocols and whether this flexibility imparts performance gains. We developed a flexible three-dimensional deep algorithm, called heterophase volumetric detection (HPVD), that can accept any combination of contrast-phase inputs with adjustable sensitivity depending on the clinical purpose. We trained HPVD on 771 DCE CT scans to detect HCCs and evaluated it on 164 positives and 206 controls. We compared performance against six clinical readers, including two radiologists, two hepatopancreaticobiliary surgeons, and two hepatologists. The area under the curve of the localization receiver operating characteristic for NC-only, NC plus VP, and full DCE CT yielded 0.71 (95% confidence interval [CI], 0.64-0.77), 0.81 (95% CI, 0.75-0.87), and 0.89 (95% CI, 0.84-0.93), respectively. At a high-sensitivity operating point of 80% on DCE CT, HPVD achieved 97% specificity, which is comparable to measured physician performance. We also demonstrated performance improvements over more typical and less flexible nonheterophase detectors. Conclusion: A single deep-learning algorithm can be effectively applied to diverse HCC detection clinical scenarios, indicating that HPVD could serve as a useful clinical aid for at-risk and opportunistic HCC surveillance.

Evaluation of nonalcoholic fatty liver disease in Japanese patients with psoriasis: Chest CT imaging for screening purposes

Psoriasis patients have been reported to have a higher prevalence of nonalcoholic fatty liver disease (NAFLD), therefore detection at an early stage is important since it may progress to hepatic cirrhosis or hepatocellular carcinoma. We evaluated liver fat accumulation in patients with moderate to severe psoriasis by chest computed tomography (CT). The images were taken for screening purposes prior to the start of any biologics. The prevalence of NAFLD in patients with psoriasis vulgaris, psoriatic arthritis, and control subjects was 19.4%, 33.3% and 9.8%, respectively (P = 0.004). The mean CT score in psoriasis patients was significantly lower (51.684 ± 12.778) than that in control subjects (61.204 ± 9.498, P < 0.001). Multivariate logistic regression analysis showed that only CT scores were associated with the presence of psoriasis (P = 0.001). No significant relationship was observed between the Psoriasis Activity and Severity Index scores and CT scores of psoriasis patients (P = 0.055), suggesting that the presence of psoriasis may contribute to the pathogenesis of NAFLD. By analysis of chest CT imaging, our study successfully assessed liver fat accumulation. Chest CT is a useful diagnostic tool for the quantitative measurement of fat accumulated in the liver, enabling the early noninvasive detection of NAFLD and early therapeutic intervention.

Fifteen-minute consultation: Child with an incidental finding of a fatty liver

The incidental finding of a fatty liver on an abdominal ultrasound scan performed for an unrelated reason in an overweight child is an increasingly common phenomenon in paediatric practice. This article will explain the steps to be taken when receiving such an ultrasound report.

Case 304: Porphyria Cutanea Tarda

HISTORY

In 2017, a 72-year-old woman was seen in the gastroenterology department with a 2-month history of mild and intermittent abdominal pain without other accompanying symptoms. Her medical history was unremarkable, except for a previous visit due to facial photodermatitis 3 years earlier. Diazepam for a sleeping disorder was the only chronic medication recorded. Results of physical examination, blood count, and basic metabolic panels including assessment of renal and liver function were normal; only the ferritin level was slightly elevated (265 ng/mL [595 pmol/L]; normal range, 10-120 ng/mL [22-269 pmol/L]). Abdominal US was performed, followed by multiphasic contrast-enhanced CT and liver MRI due to the findings of the first study. A diagnosis was not established in that moment, and acetaminophen was prescribed for pain relief. As the symptoms continued, laboratory tests and imaging studies were repeated 2 years later, with similar findings and no notable changes.

Increased Risk of NAFLD in Adults with Glomerular Hyperfiltration: An 8-Year Cohort Study Based on 147,162 Koreans

This study evaluated whether glomerular hyperfiltration (GHF) could predict nonalcoholic fatty liver disease (NAFLD) and fibrosis. A longitudinal cohort study including 147,479 participants aged 20–65 years without NAFLD and kidney disease at baseline was performed. GHF cutoff values were defined as age- and sex-specific estimated glomerular filtration rate (eGFRs) above the 95th percentile, and eGFR values between the 50th and 65th percentiles were used as reference groups. NAFLD was diagnosed via abdominal ultrasonography, and the fibrosis status was evaluated using the NAFLD fibrosis score and Fibrosis-4. During 598,745 person years of follow-up (median, 4.6 years), subjects with GHF at baseline had the highest hazard ratio (HR) for the development of NAFLD (HR 1.21; 95% CI 1.14–1.29) and fibrosis progression (HR 1.42; 95% CI 1.11–1.82) after adjusting for confounding factors. A higher baseline eGFR percentile maintained a higher risk of NAFLD and fibrosis probability. The persistent GHF group during follow-up had the highest HR for NAFLD compared to the persistent non-GHF group (HR 1.31; 95% CI 1.14–1.51). These results were consistent in all subgroups and statistically more prominent in participants without diabetes. GHF was positively associated with increased risk of NAFLD and probability of liver fibrosis in healthy adults.

Levels of abdominal adipose tissue and metabolic-associated fatty liver disease (MAFLD) in middle age according to average fast-food intake over the preceding 25 years: the CARDIA Study

BACKGROUND

Higher levels of intra-abdominal adipose tissue (IAAT) comprising visceral adipose tissue (VAT), intermuscular adipose tissue (IMAT), and liver fat are posited drivers of obesity-related chronic disease risk. Fast food is hypothesized to contribute to IAAT patterns.

OBJECTIVES

We quantified levels of abdominal subcutaneous adipose tissue (SAT), IAAT, and odds of metabolic-associated fatty liver disease (MAFLD) in middle age according to average fast-food intake over the preceding 25 y.

METHODS

We analyzed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants underwent 6 clinical exams and measurements over 25 y with computed tomography-measured VAT, SAT, and IMAT (n = 3156), plus MAFLD defined by liver attenuation (≤40 Hounsfield units) and 1 metabolic abnormality at year 25 (2010, n = 3001, n cases = 302). We estimated means of VAT, SAT, IMAT, and liver attenuation at the year 25 exam according to categories of average fast-food intake over the previous 25 y adjusted for sociodemographic and lifestyle factors and logistic regression to estimate the odds ratio of MAFLD at year 25.

RESULTS

With higher average fast-food intake over 25 y (categorized as follows: never-1×/mo, >1×-3×/mo, 1-<2×/wk, 2-<3×/wk, ≥3×/wk), there were monotonic higher levels of VAT (98.5, 127.6, 134.5, 142.0, 145.5 cm3), P-trend < 0.0001, which were consistent across anthropometrically classified obesity categories. There was a similar pattern with liver fat. There were higher levels of IMAT and SAT with higher fast-food intake (P-trend = 0.003, 0.0002, respectively), with amounts leveling off at ≥2×/wk. In addition, compared with participants who ate fast food never-1×/mo, there were monotonic higher odds of having MAFLD at year 25 with higher average fast-food intake, with participants who ate fast food ≥3×/wk having an OR of MAFLD = 5.18 (95% CI: 2.87, 9.37).

CONCLUSIONS

There were monotonic higher levels of VAT, liver fat, and odds of having MAFLD in middle age according to higher average fast-food intake over the preceding 25 y.

CT-based visual grading system for assessment of hepatic steatosis: diagnostic performance and interobserver agreement

BACKGROUND

Hepatic steatosis (HS) can be comprehensively assessed by visually comparing the hepatic and vessel attenuation on unenhanced computed tomography (CT). We aimed to evaluate the reliability and reproducibility of a CT-based visual grading system (VGS) for comprehensive assessment of HS.

METHODS

In this retrospective study, a four-point VGS based on the visual comparison of liver and hepatic vessels was validated by six reviewers with diverse clinical experience using the unenhanced CT images of 717 potential liver donors. The diagnostic performance of VGS and quantitative indices (difference and ratio of the hepatic and splenic attenuation) to diagnose HS were evaluated using multi-reader multi-case receiver operating characteristics (ROC) analysis (reference: pathology). The interobserver agreement was assessed using Fleiss κ statistics.

RESULTS

Using the VGS, all six reviewers showed areas under the ROC curves (AUROCs) higher than 0.9 for diagnosing total steatosis (TS) ≥ 30%, macrovesicular steatosis (MaS) ≥ 30%, and MaS ≥ 10%. No difference was noted between the AUROCs of the VGS and quantitative indices (p ≥ 0.1). The reviewers showed substantial agreement (Fleiss κ, 0.61). Most discrepancies occurred between the two lowest grades of VGS (81.5%; 233/283), in which most subjects (97.0%; 226/233) had a MaS < 10%. The average-reader sensitivity and specificity of the VGS were 0.80 and 0.94 to detect TS ≥ 30% and 0.93 and 0.81 to detect MaS ≥ 10%.

CONCLUSION

VGS was reliable and reproducible in assessing HS. It may be useful as a non-invasive and simple tool for comprehensive HS assessment.

Metabolik sendromda visseral ve subkutan yağ miktari ve hepatosteatozun bilgisayarli tomografi ile kantitatif değerlendirilmesi

Purpose: We aimed to evaluate visceral and subcutaneous fat tissue and its association with hepatosteatosis on computed tomography (CT) scans to determine cut-off criteria for metabolic syndrome, measure abdominal obesity directly based on the visceral fat tissue area (VFTA) rather than indirectly based on waist circumference and obtain supportive findings by density measurements in addition to the VFTA measurements.Materials and Methods: The Hounsfield unit (HU) values, visceral, subcutaneous fat areas and HU values of 108 patients diagnosed with metabolic syndrome (MS) were determined according to the National Cholesterol Education Program Adult Treatment Panel III 2001 Criteria by retrospectively analyzing their abdominal CT images taken for various reasons. The relationships of the obtained values with each other and to MS were evaluated.Results: The strongest predictor of MS was VFTA, and 156.47 cm² was the most significant value with 74.1% sensitivity and 58.6% specificity. An HU value of -102.99 for visceral fat tissue density (VFTD) was found as the second most significant finding with 75% sensitivity and 57.6% specificity. The VFTA values of the patients with hepatosteatosis were higher, and increased VFTA values were associated with lower VFTD values.Conclusion: The most important supportive finding was the demonstration of the possibility of measuring abdominal obesity, which has an important place among criteria, directly by measuring VFTA, rather than indirectly based on waist circumference. 

Fat in mass in primary liver lesions: are usual MRI diagnostic criteria of both malignant and benign liver lesions still applicable?

PURPOSE

To evaluate the accuracy of the usual MRI diagnostic patterns of primary liver lesions applied to the diagnosis of pathologically proven fat-containing liver lesions.

MATERIALS AND METHODS

This monocentric IRB approved retrospective study included all patients with pathologically proven focal liver lesions and documented intra-tumoral fat on pathology and who underwent preoperative liver MRI for characterization. Both liver morphology and usual lesion MRI features were analyzed and their distribution correlated to the final pathological result (Khi-2 or Fisher exact tests, Student t-test or Mann-Whitney U test, as appropriate). The Sensitivity (Se) and Specificity (Sp) of MRI patterns known to be associated to both Hepatocellular Carcinoma (HCC), Focal Nodular Hyperplasia (FNH), and Hepatocellular Adenoma (HCA) subtypes were evaluated.

RESULTS

Between March 2014 and November 2021, 66 lesions were included, corresponding to: 26 HCC, 32 HCA, 6 FNH and 2 hepatic angiomyolipoma (HAML). All lesions developed on a dysmorphic liver were HCC. A non-rim arterial phase hyperenhancement with a washout and an enhancing capsule had a 98% specificity for HCC diagnosis; A homogeneous dropout of signal on the opposed phase had a sensitivity of 92% and a specificity of 89% for the diagnosis of HNF1alpha inactivated subtype of HCA (HHCA). The FNH pattern was specific at 100% for the diagnosis of FNH with a 40% Se. Finally, the accuracy of inflammatory hepatocellular adenoma (IHCA) pattern had a low 60% Se but a high 89% Sp for IHCA diagnosis.

CONCLUSION

Known MRI patterns remain reliable for the accurate diagnosis of primary liver tumors on MRI even in fat-containing lesions.

Focal incidental upper abdominal findings on unenhanced chest computed tomography that do not require further imaging: a roadmap for the thoracic radiologist

Abstract Chest scans usually include the upper abdomen, leading radiologists to evaluate the upper abdominal structures. The aim of this article is to summarize the most common incidental upper abdominal findings that do not require further imaging or management in patients undergoing unenhanced computed tomography of the chest for the investigation of thoracic symptoms or diseases. We review common incidental findings of the liver, gallbladder, spleen, adrenal glands, kidney, and retroperitoneum, as well as findings that mimic other lesions. Thoracic radiologists should be aware of such typical findings and report when no further investigation is needed, thus avoiding unnecessary imaging examinations, protecting patients from additional medical interventions, and allaying patient concerns.

Ultrasonographic evaluation of patients with abnormal liver function tests in the emergency department

Ultrasonography is often the initial modality used to evaluate patients found to have abnormal liver function tests (LFTs) in the emergency department. While an assessment for biliary ductal dilatation and obstruction remains one of the main questions to answer, radiologists should also be aware of the ultrasonographic appearance of other conditions that can cause abnormal LFTs. This may be crucial for the management and disposition of patients in the emergency department. This article reviews the ultrasonographic features of diseases that may cause abnormal LFTs.

A woman presenting with an unusual cause of fulminant liver failure and sepsis

We present the case of a 61-year-old woman who presented with acutely worsening right upper quadrant pain and was found to be in acute liver failure with Klebsiella pneumoniae bacteremia. Despite aggressive intensive care management, the patient ultimately died of refractory shock attributed to sepsis and fulminant liver failure. On autopsy, she was found unexpectedly to have diffuse intrahepatic cholangiocarcinoma with metastases to regional lymph nodes and intravascular spread to the lungs. The case highlights a rare instance where intrahepatic cholangiocarcinoma presents with acute liver failure and discusses key intensive care management principles of this clinical syndrome.