A New Reporting System for Diagnosis of Hepatocellular Carcinoma in Chronic Hepatitis B With Clinical and Gadoxetic Acid-Enhanced MRI Features.

BACKGROUND: Current major guidelines for diagnosis of hepatocellular carcinoma (HCC) based on imaging findings are different from each other and do not include clinical risk factors as a diagnostic criteria. PURPOSE: To developed and validated a new diagnostic score system using MRI and clinical features as applied in chronic hepatitis B patients. STUDY TYPE: Retrospective observational study. SUBJECT: A total of 418 treatment-naïve patients (out of 902 patients) with chronic hepatitis B having 556 lesions suspected for HCC which were eligible for curative treatment. FIELD STRENGTH/SEQUENCE: T1W GRE in- and opposed-phase, T2W FSE, DWI, and T1W 3D-GRE dynamic contrast-enhanced sequences at 1.5  T and 3  T. ASSESSMENT: Six radiologists with 7-22 years of experience independently evaluated MR images based on Liver Imaging Reporting and Data System (LI-RADS) version 2018. STATISTICAL TESTS: Based on logistic regression analysis of MRI features and clinical factors, a risk score system was devised in derivation cohorts (268 patients, 352 lesions) and externally validated (150 patients, 204 lesions). The performance of the new score system was assessed by Harell's c-index. Using cutoff value of 12, maintaining positive predictive value ≥95%, the diagnostic performances of the score system were compared with those of LR-5. RESULTS: The 15-point diagnostic scoring system used MRI features (lesion size, nonrim arterial phase hyperenhancement, portal venous phase hypointensity, hepatobiliary phase hypointensity, and diffusion restriction) and clinical factors (alpha-fetoprotein and platelet). It showed good discrimination in the derivation (c-index, 0.946) and validation cohorts (c-index, 0.907). Using a risk score of 12 as a cut-off, this system yielded higher sensitivity than LR-5 (derivation cohort, 76.8% vs. 52.1%; validation cohort, 73.4% vs. 49.5%) without significant decrease in specificity (derivation cohort, 93.1% vs. 97.2%, P = 0.074; validation cohort, 91.7% vs. 96.1%, P = 0.299). DATA CONCLUSION: A new score system showed improved sensitivity in chronic hepatitis B patients compared to LI-RADS without significant compromise in specificity. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

A reliable and robust method for the upper thigh muscle quantification on computed tomography: toward a quantitative biomarker for sarcopenia.

BACKGROUND: We aimed to evaluate the feasibility of the upper thigh level as a landmark to measure muscle area for sarcopenia assessment on computed tomography (CT). METHODS: In the 116 healthy subjects who performed CT scans covering from mid-abdomen to feet, the skeletal muscle area in the upper thigh level at the inferior tip of ischial tuberosity (SMAUT), the mid-thigh level (SMAMT), and L3 inferior endplate level (SMAL3) were measured by two independent readers. Pearson correlation coefficients between SMAUT, SMAMT, and SMAL3 were calculated. Inter-reader agreement between the two readers were evaluated using intraclass correlation coefficient (ICC) and Bland-Altman plots with 95% limit of agreement (LOA). RESULTS: In readers 1 and 2, very high positive correlations were observed between SMAUT and SMAMT (r = 0.91 and 0.92, respectively) and between SMAUT and SMAL3 (r = 0.90 and 0.91, respectively), while high positive correlation were observed between SMAMT and SMAL3 (r = 0.87 and 0.87, respectively). Based on ICC values, the inter-reader agreement was the best in the SMAUT (0.999), followed by the SMAL3 (0.990) and SMAMT (0.956). The 95% LOAs in the Bland-Altman plots indicated that the inter-reader agreement of the SMAUT (- 0.462 to 1.513) was the best, followed by the SMAL3 (- 9.949 to 7.636) and SMAMT (- 12.105 to 14.605). CONCLUSION: Muscle area measurement at the upper thigh level correlates well with those with the mid-thigh and L3 inferior endpoint level and shows the highest inter-reader agreement. Thus, the upper thigh level might be an excellent landmark enabling SMAUT as a reliable and robust biomarker for muscle area measurement for sarcopenia assessment.

A Deep Residual U-Net Algorithm for Automatic Detection and Quantification of Ascites on Abdominopelvic Computed Tomography Images Acquired in the Emergency Department: Model Development and Validation.

BACKGROUND: Detection and quantification of intra-abdominal free fluid (ie, ascites) on computed tomography (CT) images are essential processes for finding emergent or urgent conditions in patients. In an emergency department, automatic detection and quantification of ascites will be beneficial. OBJECTIVE: We aimed to develop an artificial intelligence (AI) algorithm for the automatic detection and quantification of ascites simultaneously using a single deep learning model (DLM). METHODS: We developed 2D DLMs based on deep residual U-Net, U-Net, bidirectional U-Net, and recurrent residual U-Net (R2U-Net) algorithms to segment areas of ascites on abdominopelvic CT images. Based on segmentation results, the DLMs detected ascites by classifying CT images into ascites images and nonascites images. The AI algorithms were trained using 6337 CT images from 160 subjects (80 with ascites and 80 without ascites) and tested using 1635 CT images from 40 subjects (20 with ascites and 20 without ascites). The performance of the AI algorithms was evaluated for diagnostic accuracy of ascites detection and for segmentation accuracy of ascites areas. Of these DLMs, we proposed an AI algorithm with the best performance. RESULTS: The segmentation accuracy was the highest for the deep residual U-Net model with a mean intersection over union (mIoU) value of 0.87, followed by U-Net, bidirectional U-Net, and R2U-Net models (mIoU values of 0.80, 0.77, and 0.67, respectively). The detection accuracy was the highest for the deep residual U-Net model (0.96), followed by U-Net, bidirectional U-Net, and R2U-Net models (0.90, 0.88, and 0.82, respectively). The deep residual U-Net model also achieved high sensitivity (0.96) and high specificity (0.96). CONCLUSIONS: We propose a deep residual U-Net-based AI algorithm for automatic detection and quantification of ascites on abdominopelvic CT scans, which provides excellent performance.

Liver stiffness in magnetic resonance elastography is prognostic for sorafenib-treated advanced hepatocellular carcinoma.

OBJECTIVE: We investigated whether liver stiffness (LS) quantified using magnetic resonance elastography (MRE) could predict the prognosis of advanced hepatocellular carcinoma (HCC) patients treated with sorafenib. METHODS: We selected 50 sorafenib-treated advanced HCC patients who underwent MRE within 3 months before drug administration from a prospectively maintained cohort of chronic liver disease patients, according to the inclusion and exclusion criteria. Univariate and multivariate analyses were performed to evaluate the prognostic role of laboratory data, tumor characteristics, and MRE-assessed LS for overall survival (OS), progression-free survival (PFS), and significant liver injury (grade ≥ 3) after sorafenib administration. RESULTS: High MRE-assessed LS either as continuous (per kPa, hazard ratio (HR) 1.54; 95% confidence interval (CI) 1.23-1.92, p < 0.001) or categorical (> 7.5 kPa, HR 4.06, 95% CI 1.40-11.79, p < 0.01) variable was significantly associated with poor OS along with higher serum alpha-fetoprotein (AFP, ≥ 400 ng/mL) and advanced tumor stage (modified Union for International Cancer Control (mUICC) IVb). Higher MRE-assessed LS was also significantly associated with the development of significant liver injury after sorafenib administration (per kPa, HR 1.62, 95% CI 1.21-2.17, p = 0.001; > 7.5 kPa, HR 10.11, 95% CI 2.41-42.46, p = 0.002). PFS analysis identified higher serum AFP (≥ 400 ng/mL) and advanced tumor stage (mUICC IVb) as significant risk factors for early disease progression, whereas LS was not associated with PFS CONCLUSION: Higher MRE-assessed LS is a potential biomarker for predicting poor OS and significant liver injury in advanced HCC patients treated with sorafenib. KEY POINTS: • Higher pretreatment LS by MRE (> 7.5 kPa), higher AFP (≥ 400 ng/mL), and advanced tumor stage (mUICC IVb) were associated with poor OS in advanced HCC patients treated with sorafenib. • Higher pretreatment LS by MRE was associated with developing significant (grade ≥ 3) liver injury during sorafenib treatment, which required termination of the therapy. • Patients with high pretreatment LS by MRE should be monitored carefully for potential liver injury during sorafenib treatment.

Liver stiffness measured by MR elastography is a predictor of early HCC recurrence after treatment.

OBJECTIVES: Magnetic resonance elastography (MRE) is a non-invasive tool for measuring liver stiffness (LS) with high diagnostic accuracy. This study investigated whether quantified LS by MRE could predict early recurrence of patients with hepatocellular carcinoma (HCC) within the Milan criteria. METHODS: A prospectively collected cohort, which included the HCC patients who underwent MRE before treatment (an HCC-MRE cohort), was analyzed. In the HCC-MRE cohort, only patients under the Milan criteria, who underwent hepatic resection, radiofrequency ablation (RFA), or transarterial chemoembolization (TACE), were reviewed. We investigated whether LS assessed by MRE was an independent predictor of early recurrence using Cox regressions and Kaplan-Meier analyses. RESULTS: A total of 192 HCC patients under the Milan criteria who underwent hepatic resection (n = 96), RFA (n = 23), or TACE (n = 73) were included. Higher LS ratings (kPa; hazard ratio [HR] = 1.12; 95% confidence interval [CI] = 1.01-1.25; p = 0.040) emerged as an independent risk factor for early tumor recurrence. In the subgroup analysis, higher LS ratings were associated with higher risks of early HCC recurrence in both the resection/RFA group (> 4.5 kPa; HR = 2.95; 95% CI = 1.26-6.94; p = 0.013) and the TACE group (> 6 kPa; HR = 2.94; 95% CI = 1.27-6.83; p = 0.012). CONCLUSION: LS assessed by MRE was an independent predictor of early recurrence among HCC patients under the Milan criteria after achieving a complete response. KEY POINTS: • Liver parenchymal stiffness measured by MRE predicts early recurrence of treated HCC under Milan criteria. • A liver stiffness > 5.5 kPa was associated with worse recurrence-free survival. • Patients with high pre-treatment LS may benefit from stringent follow-up.

Accuracy and precision of proton density fat fraction measurement across field strengths and scan intervals: A phantom and human study.

BACKGROUND: Complex-based chemical shift imaging-based magnetic resonance imaging (CSE-MRI) is emerging as a preferred method for noninvasively quantifying proton density fat fraction (PDFF), a promising quantitative imaging biomarker (QIB) for longitudinal hepatic steatosis measurement. PURPOSE: To determine linearity, bias, repeatability, and reproducibility of the PDFF measurement using CSE-MRI (CSE-PDFF) across scan intervals, MR field strengths, and readers in phantom and nonalcoholic fatty liver disease (NAFLD) patients. STUDY TYPE: Institutional Review Board (IRB)-approved prospective. SUBJECTS: Fat-water phantom and 20 adult patients. FIELD STRENGTH/SEQUENCE: 1.5 T and 3.0 T MR systems and a commercially available CSE-MRI sequence (IDEAL-IQ). ASSESSMENT: Two independent readers measured CSE-PDFF of fat-water phantom and NAFLD patients across two field strengths and scan intervals (same-day and 2-week) each and in a combination of both. MR spectroscopy-based PDFF (MRS-PDFF) was used as the reference standard for phantom PDFF. STATISTICAL TESTS: Linearity and bias of measurement were evaluated by linear regression analysis and Bland-Altman plots, respectively. Repeatability and reproducibility were assessed by coefficient of variance and repeatability / reproducibility coefficients (RC). The intraclass correlation coefficient was used to validate intra- and interobserver agreements. RESULTS: CSE-PDFF showed high linearity and small bias (-0.6-0.4 PDFF%) with 95% limits of agreement within ±2.9 PDFF% across field strengths, 2-week interscan period, and readers in the clinical scans. CSE-PDFF was highly repeatable and reproducible both in phantom and clinical scans, with the largest observed RC across field strengths and 2-week interscan period being 3 PDFF%. DATA CONCLUSION: CSE-PDFF is a robust QIB with high linearity, small bias, and excellent repeatability/reproducibility. A change of more than 3 PDFF% across field strengths within 2 weeks of scan interval likely reflects a true change, which is well within the clinically acceptable range. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:305-314.

Sigmoid volvulus: identifying patients requiring emergency surgery with the dark torsion knot sign.

OBJECTIVES: To determine which clinical or CT imaging factors can help accurately identify complicated sigmoid volvulus (SV), defined as irreversible bowel ischaemia or necrosis requiring emergent surgery in patients with SV. METHODS: We performed a retrospective study of 51 patients admitted consecutively to the emergency department for SV. All patients attempted endoscopic detorsion as the first treatment. Clinical and contrast-enhanced CT factors were analysed. A newly described dark torsion knot sign (sudden loss of mucosal enhancement in the volvulus torsion knot) was included as a CT factor. Patients were diagnosed with complicated versus simple SV based on either surgery or follow-up endoscopic findings. Univariate and multivariate analyses were used to identify predictors of complicated SV. RESULTS: Of 51 study patients, 9 patients (17.6%) had complicated SV. Univariate analysis revealed that three clinical factors (sepsis, elevated C-reactive protein, and elevated lactic acid levels) and four CT factors (reduced bowel wall enhancement, increased bowel wall thickness, dark torsion knot sign, and diffuse omental infiltration) were significantly associated with complicated SV. Multivariate analysis identified only dark torsion knot sign (odds ratio = 104.40; p = 0.002) and sepsis (odds ratio = 16.85; p = 0.043) as independent predictive factors of complicated SV. CONCLUSION: A newly defined CT imaging factor of dark torsion knot sign and a clinical factor of sepsis can predict complicated SV necessitating emergent surgery instead of colonoscopic detorsion as a primary treatment of choice. KEY POINTS: • A newly defined CT imaging factor of dark torsion knot sign and a clinical factor of sepsis can be helpful for predicting complicated SV necessitating emergent surgery instead of endoscopic detorsion.

Plasma MicroRNA-21, 26a, and 29a-3p as Predictive Markers for Treatment Response Following Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma.

BACKGROUND: We investigated an association between the levels of plasma microRNA (miRNA)-21, -26a, and -29a-3p and treatment outcomes following transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). METHODS: A total of 198 patients with TACE-treated HCC were followed up for TACE refractoriness and liver transplantation (LT)-free survival. Pretreatment plasma miRNA-21, -26a, and -29a-3p levels were measured using quantitative real-time polymerase chain reaction. RESULTS: During the mean follow-up of 22.3 (range, 0.7-79) months, 118 (59.6%) patients exhibited TACE refractoriness. Multivariate analyses showed that expression of a specific combination of miRNAs (miRNA-21 ≥ 2.5, miRNA-26a ≥ 1.5, and miRNA-29a-3p < 0.4) was associated with early TACE refractoriness (within 1 year; hazard ratio [HR], 2.32; 95% confidence interval [CI], 1.08-4.99; P = 0.031) together with tumor size (HR, 4.62; 95% CI, 1.50-14.21; P = 0.008), and macrovascular invasion (HR, 3.80; 95% CI, 1.19-12.20; P = 0.025). However, miRNA-21, -26a, and -29a-3p levels were not significantly associated with overall TACE refractoriness or LT-free survival. Additionally, large tumor size and macrovascular invasion were common predictive factor of overall TACE refractoriness and survival. CONCLUSION: Combination of plasma miRNA-21, -26a, and -29a-3p expression could predict early TACE refractoriness in patients with TACE-treated HCC.

Development of Risk Prediction Model for Hepatocellular Carcinoma Progression of Indeterminate Nodules in Hepatitis B Virus-Related Cirrhotic Liver.

OBJECTIVES: This study was performed to evaluate long-term outcome of indeterminate nodules detected on cirrhotic liver and to develop risk prediction model for hepatocellular carcinoma (HCC) progression of indeterminate nodules on hepatitis B virus (HBV)-related cirrhotic liver. METHODS: Indeterminate nodules up to 2 cm with uncertain malignant potential detected on computed tomography of cirrhotic liver during HCC surveillance were analyzed retrospectively. HCC risk prediction model of indeterminate nodules in HBV-related cirrhotic liver was deduced based on result of Cox regression analysis. RESULTS: A total of 494 indeterminate nodules were included. Independent risk factors of HCC progression were old age, arterial enhancement, large nodule size, low serum albumin level, high serum α-fetoprotein (AFP) level, and prior HCC history in all included subjects. In subjects with chronic hepatitis B, old age (year; hazard ratio (HR)=1.06; P<0.001), arterial enhancement (HR=2.62; P=0.005), large nodule size (>1 cm; HR=7.34; P<0.001), low serum albumin level (≤3.5 g/dl; HR=3.57; P=0.001), high serum AFP level (≥100 ng/ml; HR=6.04; P=0.006), prior HCC history (HR=4.24; P=0.001), and baseline hepatitis B e antigen positivity (HR=2.31; P=0.007) were associated with HCC progression. We developed a simple risk prediction model using these risk factors and identified patients at low, intermediate, and high risk for HCC; 5-year cumulative incidences were 1%, 14.5%, and 63.1%, respectively. The developed risk score model showed good performance with area under the curve at 0.886 at 3 years, and 0.920 at 5 years in leave-one-out cross-validation. CONCLUSIONS: We developed a useful and accurate risk score model for predicting HCC progression of indeterminate nodules detected on HBV-related cirrhotic liver.

Higher serum interleukin-17A levels as a potential biomarker for predicting early disease progression in patients with hepatitis B virus-associated advanced hepatocellular carcinoma treated with sorafenib.

BACKGROUND: Although sorafenib is the only available drug with proven efficacy for patients with advanced hepatocellular carcinoma (HCC), the clinical efficacy of sorafenib is variable and unpredictable. The aim of the current study was to identify potential serum biomarkers predicting cancer progression and overall survival (OS) in patients with hepatitis B virus (HBV)-related advanced HCC treated with sorafenib. METHODS: Thirty-four patients with HBV-related advanced HCC (modified Union for International Cancer Control [UICC] stage IVa or IVb) treated with sorafenib for more than 4weeks were retrospectively enrolled. Using a Luminex 200 system, 11 cytokines including interleukin-17A (IL-17A) were measured in baseline serum samples prior to sorafenib administration. Several clinical factors and the serum concentrations of the 11 cytokines were analyzed using Cox regression analysis. RESULTS: In the analysis of progression-free survival (PFS), older age (year; hazard ratio [HR]=1.07; 95% confidence interval [CI]=1.00-1.15; P=0.046) and higher baseline serum IL-17A level (>1.94pg/mL; HR=19.96; 95% CI=3.32-119.86; P=0.001) were identified as significant risk factors for early progression with good predictive power (Harrell's C=0.817, standard error estimates (se)=0.085). In the analysis of OS, higher Child-Pugh score (>5; HR=2.35, 95% CI=1.09-5.10, P=0.030) and lower serum baseline fibroblast growth factor-2 level (≤20.57pg/mL; HR=3.24, 95% CI=1.22-8.60, P=0.018) were identified as negative predictive factors for OS, even though the model did not have significant predictive power (Harrell's C=0.634, se=0.062). CONCLUSION: A higher serum IL-17A level is a potential biomarker for predicting poor PFS in patients with HBV-related advanced HCC treated with sorafenib.

Feasibility of mesorectal vascular invasion in predicting early distant metastasis in patients with stage T3 rectal cancer based on rectal MRI.

OBJECTIVES: To evaluate the feasibility of mesorectal vascular invasion (MVI) in predicting early distant metastasis developed within 1 year of diagnosis of T3 rectal cancer using magnetic resonance imaging (MRI) METHODS: Sixty-five patients with T3 rectal cancer (early metastasis, n = 28; non-metastasis, n = 37) were enrolled in this study. Early distant metastases developed in 28 patients (liver, n = 15; lung, n = 9; both, n = 4). Logistic regression was used to determine the independent predictors for early distant metastasis. RESULTS: In univariate analysis, tumour location, carcinoembryonic antigen (CEA), lymphovascular invasion (LVI), MRI-detected MVI, and mesorectal fat infiltration (MFI) (odds ratio [OR], 4.533, 9.583, 5.539, 27.046, and 5.539, respectively) were associated with early distant metastasis. Multivariate analysis demonstrated that MVI (OR, 29.949; P < 0.002) and LVI (OR, 6.684; P = 0.033) were independent factors for early distant metastasis. Specificity and positive predictive value (PPV) of MVI (94.59%, and 89.47%, respectively) were significantly higher than those of LVI (64.86%, and 61.76%), but sensitivity and negative predictive value were not significantly different between MVI (60.71%, and 76.09%) and LVI (75.00%, and 77.42%). CONCLUSIONS: While sensitivity of MRI-detected MVI was equal to that of CEA in predicting early distant metastasis from T3 rectal cancer, specificity and PPV may be improved by assessing MVI. KEY POINTS: • Mesorectal vascular invasion (MVI) may be a radiologic prognostic factor for rectal cancer. • Specificity of MVI was higher than lymphovascular invasion in predicting early metastasis. • Mesorectal vascular invasion may be a better predictor for early distant metastasis.

Interleukin-8 level as a prognostic marker in patients with hepatitis B virus-associated hepatocellular carcinoma treated with transarterial chemoembolization.

We investigated the association between serum interleukin (IL)-8 levels and post-transarterial chemoembolization (TACE) outcomes in patients with hepatitis B virus (HBV)-associated HCC. We enrolled 119 TACE-treated patients with HBV-associated HCC; TACE refractoriness and liver transplantation (LT)-free survival were evaluated during follow-up. Pre-TACE serum levels of various cytokines (epidermal growth factor [EGF], fibroblast growth factor 2, granulocyte-colony stimulating factor [G-CSF], interferon-γ, IL-8, IL-12, IL-17A, interferon-γ-inducible protein-10, monocyte chemotactic protein-1, tumor necrosis factor-α and vascular endothelial growth factor) were analyzed. During a mean follow-up of 24.3 (1-79) months, 91 patients (76.5%) exhibited TACE refractoriness. In multivariate analyses, multiple tumors (hazard ratio [HR], 2.37; 95% confidence interval [CI], 1.28-4.39; P=0.006), large tumor size (HR, 2.36; 95% CI, 1.38-4.03; P=0.002), and combination of alpha-fetoprotein and IL-8 levels (AFP>400 ng/mL or IL-8>32 pg/mL; HR, 1.72; 95% CI, 1.03-2.85; P=0.037) independently predicted overall TACE refractoriness. Higher EGF (>35 pg/mL) and lower G-CSF levels (⩽ 12.5 pg/mL) were associated with early TACE refractoriness (<1 year; HR, 3.47; 95% CI, 1.01-11.96; P=0.049 and HR, 6.25; 95% CI, 1.62-23.81; P=0.008, respectively). Furthermore, high IL-8 level (>32 pg/mL; HR, 1.68; 95% CI, 1.09-2.59; P=0.020) was associated with poor LT-free survival. In conclusion, pretreatment serum IL-8 is a useful prognostic marker for TACE refractoriness and LT-free survival in TACE-treated patients with HBV-associated HCC.

Comparison of Ultrasound-Guided Core Needle Biopsy and Endoscopic Ultrasound-Guided Fine-Needle Aspiration for Solid Pancreatic Lesions.

OBJECTIVES: The objective of our study was to compare the diagnostic yield of endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) using a 25-gauge needle and ultrasound (US)-guided core needle biopsy (CNB) using an 18-gauge core needle for diagnosis of solid pancreatic lesions. METHODS: This retrospective study was approved by our Institutional Review Board, and the requirement for informed consent was waived. Patients who underwent either EUS-guided FNA or US-guided CNB for a solid pancreatic lesion from January 2008 to December 2012 were included and reviewed. Fine-needle aspirations and CNBs were performed by experienced endoscopists and radiologists. The diagnostic yield, accuracy, technical failure rate, sensitivity, and specificity for malignancy were calculated and compared. RESULTS: A total of 106 biopsy attempts were undertaken in 89 patients (EUS-guided FNA, n = 70; US-guided CNB, n = 36). Biopsy specimens were successfully obtained in 98 biopsy attempts (EUS-guided FNA, n = 63; US-guided CNB, n = 35). The accuracy, technical failure rate, sensitivity, and specificity of EUS-guided FNA for malignancy (73.02%, 10.00%, 77.78%, and 44.44%, respectively) was not significantly different from those of US-guided CNB (88.57%, 2.78%, 87.10%, and 100%, respectively; P ≥ .089). Diagnostic performance did not differ between the modalities according to the size and the location of the lesion in the pancreas. However, the diagnostic yield of US-guided CNB (86.11%) was higher than that of EUS-guided FNA (65.71%, P = .035). CONCLUSIONS: The diagnostic yield of US-guided CNB for solid pancreatic lesions is superior to that of EUS-guided FNA.

Assessment of angiogenesis of hepatocellular carcinoma using dynamic contrast enhanced MR and histopathologic correlation in an experimental rat model.

BACKGROUND/AIMS: To assess the perfusion parameters and angiogenesis of HCC using dynamic contrast enhanced(DCE) MR and to correlate it with histopathologic findings in an experimental rat model. METHODOLOGY: Twenty rats were continuously infused with diethylnitrosamine (DEN) for tumor induction. After 32 to 36 weeks of DEN treatment, the rats underwent MRI of the liver with a 3-T MR imaging system. Perfusion parametric maps and perfusion parameters such as, time to peak (TTP) and peak enhancement (PE) were obtained by using a commercially available software package. The nodules were correlated precisely to DCE MR images. RESULTS: A total of 13 nodules were found in 12 rats; 5 dysplastic nodule (DN)s were identified in 5 rats and 8 HCCs (3 Edmonson grade I, 2 Edmonson grade I-II, 3 Edmonson grade II) were found in 7 rats. There were significant differences in mean values of PE and HPH (histogram peak height) of PE between DN and HCC. Mean value and HPH of PE showed statistically significant correlation with tumor grade. CONCLUSIONS: There were significant differences in perfusion parameters between DN and HCC. DCE MR imaging can be used in the differential diagnosis and management of liver disease in hepatocarcinogenesis.

[Development of Entrustable Professional Activity, Core Competencies, and Guidelines in 2021 Radiology Competency Education Project]. / 2021ë „ 대한영상의학회 ì „ê³µì˜ 연차별 ìˆ˜ë ¨êµê³¼ê³¼ì • 체계화 구축 ì‚¬ì— ì—ì„œ 개발한 위임가능 ì „ë¬¸ì§ë¬´(Entrustable Professional Activity)와 필수 핵심역량 평가항목 및 평가 가이드라인.

To provide high-quality training to residents in a rapidly changing medical environment, it is very important to improve the annual training curriculum centered on competency and ensure that training hospitals maintain an environment suitable for training. The Korean Society of Radiology (KSR) has been steadily improving the training system and has suggested the improvement of the training system by strengthening the competency-based evaluation and faculty development. Currently, KSR was selected for the second annual training curriculum systematization construction project in July 2021, and developed entrustable professional activities, core competencies, and assessment guidelines required by the construction project. Therefore, the development process and assessment guidelines will be introduced to residents and the faculty.

Risk Prediction Model Based on Magnetic Resonance Elastography-Assessed Liver Stiffness for Predicting Posthepatectomy Liver Failure in Patients with Hepatocellular Carcinoma.

BACKGROUND/AIMS: Posthepatectomy liver failure (PHLF) is a major complication that increases mortality in patients with hepatocellular carcinoma after surgical resection. The aim of this retrospective study was to evaluate the utility of magnetic resonance elastography-assessed liver stiffness (MRE-LS) for the prediction of PHLF and to develop an MRE-LS-based risk prediction model. METHODS: A total of 160 hepatocellular carcinoma patients who underwent surgical resection with available preoperative MRE-LS data were enrolled. Clinical and laboratory parameters were collected from medical records. Logistic regression analyses were conducted to identify the risk factors for PHLF and develop a risk prediction model. RESULTS: PHLF was present in 24 patients (15%). In the multivariate logistic analysis, high MRE-LS (kPa; odds ratio [OR] 1.49, 95% confidence interval [CI] 1.12 to 1.98, p=0.006), low serum albumin (≤3.8 g/dL; OR 15.89, 95% CI 2.41 to 104.82, p=0.004), major hepatic resection (OR 4.16, 95% CI 1.40 to 12.38, p=0.014), higher albumin-bilirubin score (>-0.55; OR 3.72, 95% CI 1.15 to 12.04, p=0.028), and higher serum α-fetoprotein (>100 ng/mL; OR 3.53, 95% CI 1.20 to 10.40, p=0.022) were identified as independent risk factors for PHLF. A risk prediction model for PHLF was established using the multivariate logistic regression equation. The area under the receiver operating characteristic curve (AUC) of the risk prediction model was 0.877 for predicting PHLF and 0.923 for predicting grade B and C PHLF. In leave-one-out cross-validation, the risk model showed good performance, with AUCs of 0.807 for all-grade PHLF and 0. 871 for grade B and C PHLF. CONCLUSIONS: Our novel MRE-LS-based risk model had excellent performance in predicting PHLF, especially grade B and C PHLF.

Added Value of CT Arterial Subtraction Images in Liver Imaging Reporting and Data System Treatment Response Categorization for Transcatheter Arterial Chemoembolization-Treated Hepatocellular Carcinoma.

OBJECTIVES: The aim of this study was to assess the benefit of adding arterial subtraction images from computed tomography (CT) to the Liver Imaging Reporting and Data System (LI-RADS) v2018 treatment response (LR-TR) categorization in patients treated with transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This retrospective study included 115 patients with 151 HCCs treated by TACE using an emulsion of doxorubicin and iodized oil who underwent multiphasic CT protocol that additionally generated arterial subtraction images based on nonrigid anatomic correction algorithm. Of 151 HCCs, 67 (44.4%) were viable and 84 (55.6%) were nonviable. Two independent readers assessed the per-lesion LR-TR categories in set 1 of multiphasic CT images alone and set 2 including both set 1 and CT arterial subtraction images, besides diagnostic confidence, and the quality of subtraction images. The sensitivity and specificity of LR-TR viable category between the sets were compared using the generalized estimating equation. Interobserver agreements of LR-TR categorization in each set and the quality of subtraction images were assessed by Cohen κ. RESULTS: The quality of subtraction images was mostly good to perfect (98.7%) with good interobserver agreement (κ = 0.71), and none were nondiagnostic. For detecting viable HCC, LR-TR viable category showed sensitivity of 53.7% to 56.7% and specificity of 96.4% to 98.8% in set 1. In comparison, set 2 showed significantly higher sensitivity of 88.1% to 89.6% (P < 0.002) and equivalent specificity of 94% to 95.2% (P > 0.13) for the same category. In sets 1 and 2, 31.3% to 34.3% and 9% to 10.4% of viable HCC were miscategorized as LR-TR nonviable, respectively. LR-TR equivocal category was less assigned in set 2 (1.3%) than in set 1 (6.6%-7.9%). Set 2 showed slightly higher level of confidence for LR-TR categorization compared with set 1 (3.4 ± 0.8 vs 3.8 ± 0.5). Interobserver agreement was excellent in both sets (κ = 0.85 in set 1 and 0.97 in set 2). CONCLUSIONS: The LR-TR viable category is highly specific but inadequately sensitive for detecting viable tumor in TACE-treated HCC on conventional multiphasic CT. Adding arterial subtraction images to the conventional CT images significantly increases sensitivity without compromising the specificity and improves the diagnostic confidence of LR-TR viable category.

Combining hepatic surface nodularity and serum tests better predicts hepatic fibrosis stages in chronic liver disease.

PURPOSE: Hepatic surface nodularity quantified on CT images has shown promising results in staging hepatic fibrosis in chronic hepatitis C. The aim of this study was to evaluate hepatic surface nodularity, serum fibrosis indices, and a linear combination of them for staging fibrosis in chronic liver disease, mainly chronic hepatitis B. METHODS: We developed a semiautomated software quantifying hepatic surface nodularity on CT images. Hepatic surface nodularity and serum fibrosis indices were assessed in the development group of 125 patients to generate 3 linear models combining hepatic surface nodularity with the aspartate aminotransferase to platelet ratio index, fibrosis-4 index, or platelet count in reference to the METAVIR scoring system. The models were validated in 183 patients. RESULTS: Hepatic surface nodularity and serum fibrosis indices all significantly correlated with fibrosis stages. For binary classifications into cirrhosis (F4), advanced fibrosis (≥ F3), and significant fibrosis (≥ F2), hepatic surface nodularity was significantly different across categories. The areas under the curve (AUCs) of the best model were 0.901, 0.872, and 0.794 for cirrhosis, advanced fibrosis, and significant fibrosis, respectively, higher than serum fibrosis indices alone (0.797-0.802, 0.799-0.818, and 0.761-0.773). In the validation group, the same model likewise showed higher AUCs (0.872, 0.831, and 0.850) compared to serum fibrosis indices (0.722-0.776, 0.692-0.768, and 0.695-0.769; p < 0.001 for F4). CONCLUSION: Hepatic surface nodularity combined with serum blood test could be a practical method to predict cirrhosis, advanced fibrosis, and significant fibrosis in chronic liver disease patients, providing higher accuracy than using serum fibrosis indices alone.

Reproducibility of hepatic MR elastography across field strengths, pulse sequences, scan intervals, and readers.

PURPOSE: To evaluate the reproducibility of hepatic MRE under various combinations of settings of field strength, pulse sequence, scan interval, and reader in non-alcoholic fatty liver disease (NAFLD) patients. METHODS: Adult NAFLD patients were prospectively enrolled for serial hepatic MRE with 1.5 T using 2D GRE sequence and 3.0 T using 2D SE-EPI sequence on the same day and after 2 weeks, resulting a total of four MRE examinations per patient. Three readers with various levels of background knowledge in MRE technique and liver anatomy measured liver stiffness after a training session. Linear regression, Bland-Altman analysis, within-subject coefficient of variation, and reproducibility coefficient (RDC) were used to determine reproducibility of hepatic MRE measurement. RESULTS: Twenty patients completed the MRE sessions. Liver stiffness through MRE showed pooled RDC of 26% (upper 95% CI 30.6%) and corresponding limits of agreement (LOA) within 0.55 kPa across field strengths, MRE sequences, and 2-week interscan interval in three readers. Small mean biases and narrow LOA were observed among readers (0.05-0.19 kPa ± 0.53). CONCLUSION: The magnitude of change across combinations of scan parameters is within acceptable clinical range, rendering liver stiffness through MRE a reproducible quantitative imaging biomarker. A lower reproducibility was observed for measurements under different field strengths/MRE sequences at a longer (2 weeks) interscan interval. Operators should be trained to acquire region of interest consistently in repeat examinations.

Focal eosinophilic infiltration versus metastasis in the liver: comparison of MRI findings.

BACKGROUNDS/AIMS: This article was studied to compare the MRI findings of focal hepatic eosinophilic infiltration and hepatic metastasis. METHODOLOGY: Contrast enhanced MR images of 40 lesions in 15 patients with focal hepatic eosinophilic infiltration and 34 lesions in 17 patients with liver metastasis were reviewed retrospectively. The size, number and location of focal lesions were analyzed. The lesion-to-liver contrast difference of each lesion was recorded using region of interest (ROI) curve on T1- and T2-weighted images. Enhancement pattern was classified into homogenous, rim-enhancement and heterogeneous enhancement. All the images were reviewed by two gastrointestinal radiologists in consensus. RESULTS: Focal eosinophilic infiltration and hepatic metastasis showed predominantly low signal intensity on T1WI and high signal intensity on T2WI. However, focal eosinophilic infiltration manifested as iso signal intensity, more frequently than hepatic metastasis on T1WI (42.5% vs. 0%). Metastasis showed more frequently high signal intensity on portal (94.1% vs. 57.5%) and delayed phase (94.1% vs. 45.0%) comparing with focal eosinophilic infiltration. The lesion-to-liver contrast was greater in metastasis on both images (19 +/- 17 vs. 8 +/- 6 on T1WI and 21 +/- 19 vs. 13 +/- 10 on T2WI). Rim enhancement pattern is more frequently seen in metastasis on all phases. Seventeen (43%) focal eosinophilic infiltrations showed rim enhancement on arterial or portal venous phase and homogenous enhancement on delayed phase. CONCLUSION: MRI findings to favor eosinophilic infiltration include subcapsular location, lesser lesion-to-liver contrast on T1 and T2 weighted image and early rim enhancement with layed homogenous enhancement.