Search

To compare the image quality and performance of half-Fourier acquisition single-shot turbo spin echo (HASTE) sequences, using compressed sensing (HASTE-CS) and deep-learning based reconstruction (HASTE-DL) in detecting focal liver lesions (FLLs), to those of T2-weighted image using BLADE sequence (T2WI) in patients at risk of developing hepatocellular carcinoma (HCC).This retrospective study included patients at risk of developing HCC who underwent liver MRI including HASTE-DL, HASTE-CS, T2WI and DWI between January and June 2020. Three radiologists independently reviewed the image quality along with FLL detection in the three T2-based sequences and DWI. Reference lesion characterization was done using the complete set of MRI sequences according to the Liver Imaging Reporting and Data System (LI-RADS) v2018.A total of 227 patients with 88 of whom had FLLs (n = 194, mean size 11.7 ± 10.9 mm) were included. HASTE-DL yielded the highest overall image quality, followed by HASTE-CS and T2WI (3.4 ± 0.5, 3.1 ± 0.6, 2.4 ± 0.5, respectively, P 0.001 for all). In the detection of FLLs, HASTE-DL showed significantly higher sensitivity than T2WI (51.5 % vs 43.6 %, P = 0.007) whereas HASTE-CS and T2WI bore respectively little difference (P 0.017) on per-patient basis. For LR-4, -5, -M lesions, HASTE-DL had significantly higher figure of merit than that of T2WI (0.58 vs 0.52, P 0.001) in per-lesion basis.HASTE-DL demonstrated better image quality and higher performance for FLL detection than conventional T2WI in patients at risk of developing HCC.

To determine whether Sonazoid-enhanced ultrasound (SZUS) was noninferior to SonoVue-enhanced ultrasound (SVUS) in diagnosing hepatocellular carcinoma (HCC) using the same diagnostic criteria.This prospective, single-center, noninferiority study (NCT04847726) enrolled 105 at-risk participants (71 male; mean age ± standard deviation, 63 ± 11 years; range, 26-86 years) with treatment-naïve solid hepatic nodules (≥ 1 cm). All participants underwent same-day SZUS (experimental method) and SVUS (control method) for one representative nodule per participant. Images were interpreted by three readers (the operator and two independent readers). All malignancies were diagnosed histopathologically, while the benignity of other lesions was confirmed by follow-up stability or pathology. The primary endpoint was per-lesion diagnostic accuracy for HCC pooled across three readers using the conventional contrast-enhanced ultrasound diagnostic criteria, including arterial phase hyperenhancement followed by mild (assessed within 2 minutes after contrast injection) and late (≥ 60 seconds with a delay of 5 minutes) washout. The noninferiority delta was -10%p. Furthermore, different time delays were compared as washout criteria in SZUS, including delays of 2, 5, and10 minutes.A total of 105 lesions (HCCs [n = 61], non-HCC malignancies [n = 19], and benign [n = 25]) were evaluated. Using the 5-minutes washout criterion, per-lesion accuracy of SZUS pooled across the three readers (72.4%; 95% confidence interval [CI], 64.1%-79.3%) was noninferior to that of SVUS (71.4%; 95% CI, 63.1%-78.6%), meeting the statistical criterion for non-inferiority (difference of 0.95%p; 95% CI, -3.8%p-5.7%p). The arterial phase hyperenhancement combined with the 5-minutes washout criterion showed the same sensitivity as that of the10-minutes criterion (59.0% vs. 59.0%,SZUS was noninferior to SVUS for diagnosing HCC in at-risk patients using the same diagnostic criteria. No significant improvement in HCC diagnosis was observed by extending the washout time delay from 5 to 10 minutes.

Background The Liver Imaging Reporting and Data System (LI-RADS), version 2018, treatment response algorithm (TRA) is used to assess hepatocellular carcinoma (HCC) after local-regional therapy (LRT). However, its diagnostic performance has not yet been fully compared between CT and hepatobiliary agent (HBA)-enhanced MRI in patients who have undergone liver transplant (LT). Purpose To compare the diagnostic performance of LI-RADS TRA when using CT versus using HBA-enhanced MRI in an intraindividual manner according to pathologic results. Materials and Methods Between January 2011 and September 2019, 165 patients with 237 clinically suspected HCCs underwent LRT followed by LT and were retrospectively included. All patients underwent both CT and HBA-enhanced MRI after LRT and before LT. Three radiologists independently assessed tumor viability with both modalities by using LI-RADS TRA and reached a consensus. Pathologic tumor viability categorized as either completely (100%) or incompletely (

To compare lesion conspicuity and image quality of arterial phase images obtained from low kVp (90-kVp) and dual-energy (DE) scans for the evaluation of hypervascular hepatocellular carcinoma (HCC). This retrospective study included 229 patients with HCC who underwent either 90 kVp (n = 106) or DE scan (80- and 150-kVp with a tin filter) (n = 123) during the arterial phase. DE scans were reconstructed into a linearly blended image with a mixed ratio of 0.6 (60% 80kVp and 40% 150 kVp) and post-processed for 40 keV and 50 keV images. The contrast-to-noise ratio (CNR) of HCC to the liver and image noise was measured. Lesion conspicuity, liver parenchymal image quality, and overall image preference were assessed qualitatively by three independent radiologists. DE 40 keV images had the highest CNR of HCC, and DE blended images had the lowest image noise among four image sets (p = 0.01 and p 0.05). For qualitative analyses, DE blended images had the highest scores for image quality and overall image preference (ps

Objectives The 9th International Forum for Liver Magnetic Resonance Imaging (MRI) was held in Singapore in September 2019, bringing together radiologists and allied specialists to discuss the latest developments in and formulate consensus statements for liver MRI, including the applications of gadoxetic acid–enhanced imaging. Methods As at previous Liver Forums, the meeting was held over 2 days. Presentations by the faculty on days 1 and 2 and breakout group discussions on day 1 were followed by delegate voting on consensus statements presented on day 2. Presentations and discussions centered on two main meeting themes relating to the use of gadoxetic acid–enhanced MRI in primary liver cancer and metastatic liver disease. Results and conclusions Gadoxetic acid–enhanced MRI offers the ability to monitor response to systemic therapy and to assist in pre-surgical/pre-interventional planning in liver metastases. In hepatocellular carcinoma, gadoxetic acid–enhanced MRI provides precise staging information for accurate treatment decision-making and follow-up post therapy. Gadoxetic acid–enhanced MRI also has potential, currently investigational, indications for the functional assessment of the liver and the biliary system. Additional voting sessions at the Liver Forum debated the role of multidisciplinary care in the management of patients with liver disease, evidence to support the use of abbreviated imaging protocols, and the importance of standardizing nomenclature in international guidelines in order to increase the sharing of scientific data and improve the communication between centers. Key Points • Gadoxetic acid–enhanced MRI is the preferred imaging method for pre-surgical or pre-interventional planning for liver metastases after systemic therapy. • Gadoxetic acid–enhanced MRI provides accurate staging of HCC before and after treatment with locoregional/biologic therapies. • Abbreviated protocols for gadoxetic acid–enhanced MRI offer potential time and cost savings, but more evidence is necessary. The use of gadoxetic acid–enhanced MRI for the assessment of liver and biliary function is under active investigation.

OBJECTIVE To investigate the diagnostic performance of contrast-enhanced ultrasound (CEUS) and its role as a second-line imaging modality after gadoxetate-enhanced MRI (Gd-EOB-MRI) in the diagnosis of hepatocellular carcinoma (HCC) among at risk observations. MATERIALS AND METHODS We prospectively enrolled participants at risk of HCC with treatment-naive solid hepatic observations (≥ 1 cm) of Liver Imaging Reporting and Data System (LR)-3/4/5/M during surveillance and performed Gd-EOB-MRI. A total of one hundred and three participants with 103 hepatic observations (mean size, 28.2 ± 24.5 mm; HCCs [n = 79], non-HCC malignancies [n = 15], benign [n = 9]; diagnosed by pathology [n = 57], or noninvasive method [n = 46]) were included in this study. The participants underwent CEUS with sulfur hexafluoride. Arterial phase hyperenhancement (APHE) and washout on Gd-EOB-MRI and CEUS were evaluated. The distinctive washout in CEUS was defined as mild washout 60 seconds after contrast injection. The diagnostic ability of Gd-EOB-MRI and of CEUS as a second-line modality for HCC were determined according to the European Association for the Study of the Liver (EASL) and the Korean Liver Cancer Association and National Cancer Center (KLCA-NCC) guidelines. The diagnostic abilities of both imaging modalities were compared using the McNemar's test. RESULTS The sensitivity of CEUS (60.8%) was lower than that of Gd-EOB-MRI (72.2%, p = 0.06 by EASL; 86.1%, p < 0.01 by KLCA-NCC); however, the specificity was 100%. By performing CEUS on the inconclusive observations in Gd-EOB-MRI, HCCs without APHE (n = 10) or washout (n = 12) on Gd-EOB-MRI further presented APHE (80.0%, 8/10) or distinctive washout (66.7%, 8/12) on CEUS, and more HCCs were diagnosed than with Gd-EOB-MRI alone (sensitivity: 72.2% vs. 83.5% by EASL, p < 0.01; 86.1% vs. 91.1% by KCLA-NCC, p = 0.04). There were no false-positive cases for HCC on CEUS. CONCLUSION The addition of CEUS to Gd-EOB-MRI as a second-line diagnostic modality increases the frequency of HCC diagnosis without changing the specificities.

To compare the diagnostic performances of first and second portal venous phases (PVP1 and PVP2) in revealing washout and capsule appearance for non-invasive HCC diagnoses in gadoxetic acid–enhanced MRI (Gd-EOB-MRI). This retrospective study included 123 at-risk patients with 160 hepatic observations (HCCs, n = 116; non-HCC malignancies, n = 18; benign, n = 26) showing arterial phase hyper-enhancement (APHE) ≥ 1 cm at Gd-EOB-MRI. The mean time intervals from gadoxetic acid injection to PVP1 and PVP2 acquisitions were 53 ± 2 s and 73 ± 3 s, respectively. After evaluating image findings independently, imaging findings and diagnoses were finalized by a consensus of two radiologists using either PVP1 or PVP2 image sets according to the LI-RADS v2018 or EASL criteria. Sensitivity, specificity, and accuracy were compared. Among HCCs, more washout and enhancing capsule were observed in PVP2 (83.6% and 27.6%) than in PVP1 (50.9% and 19.8%) (p

To evaluate the diagnostic performance of whole-body MRI (WB-MRI) including contrast-enhanced T1-weighted imaging (T1WI) and WB-DWI in rectal cancer initial staging. This retrospective study was approved by the IRB and the requirement of informed consent was waived. From September 2013 to Feb 2015, patients who underwent rectal MRI including WB-MRI, as well as chest and abdominopelvic CT for initial staging, were included. WB-MRI consisted of contrast-enhanced T1-weighted imaging and DWI covering neck to the pelvis. Three radiologists reviewed WB-MRI and CECT independently for the M-classification. The diagnostic performance of CECT and WB-MRI was compared using a reference standard incorporating histology, FDG-PET results, and clinical follow-up. A total of 139 patients (male:female = 89:50, mean age 63.2 ± 12.4 years) were included and metastasis was observed in 15.2% (21/139). WB-MRI showed significantly higher specificity (96.7% [114/118] vs. 85.6% [101/118], p = 0.001) and positive predictive value (PPV) (80% [16/20] vs. 48.5% [16/33], p 0.99) and negative predictive value (95.3% [101/106] at CECT vs. 95.8% [114/119] at WB-MRI, p = 0.77) between CECT and WB-MRI. WB-MRI showed higher specificity and PPV than CECT in newly diagnosed rectal cancer. Adding WB-MRI to standard rectal MRI is a feasible option for initial staging workup of rectal cancer. • WB-MRI showed a higher specificity and PPV than those of CECT for identifying metastasis at initial staging workup of rectal cancer. • WB-MRI and CECT did not show a significant difference in sensitivity and NPV for the M-classification. • WB-MRI can be used as an alternative to CECT for the initial M-classification modality in newly diagnosed rectal cancer.

When radiologists interpret hepatic focal lesions seen on dynamic magnetic resonance imaging (MRI) scans, it is important not only to distinguish malignant lesions from benign ones but also to distinguish nonhepatocellular carcinoma (HCC) malignancies from HCCs. In addition, most major guidelines, including those of the American Association for the Study of Liver Disease, European Association for the Study of the Liver, and Korean Liver Cancer Association and National Cancer Center, allow for the noninvasive imaging diagnosis of HCC in at-risk patients. However, ~40% of HCC cases show atypical imaging features mimicking non-HCC malignancies. Furthermore, several benign and malignant lesions, such as flash-filling hemangioma and intrahepatic mass-forming cholangiocarcinoma, frequently look like HCC. In contrast, although multiparametric MRI options, including hepatobiliary phase and diffusion-weighted imaging, provide useful information that could help address these challenges, there remain several unresolved issues with regard to the noninvasive diagnostic criteria characterizing HCC. In this article, we discuss the typical imaging features and challenging situations related to primary liver cancers in MRI, while considering how to make a correct diagnosis. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.

Purpose This study aimed to assess the technical performance of ElastQ Imaging compared with ElastPQ and to investigate the correlation between liver stiffness (LS) values obtained using these two techniques. Methods This retrospective study included 249 patients who underwent LS measurements using both ElastPQ and ElastQ Imaging equipped on the same machine. The applicability, repeatability (coefficient of variation [CV]), acquisition time, and LS values were compared using the chi-square or Wilcoxon signed-rank tests. In the development group, the correlation between the LS values obtained by the two techniques was assessed with Spearman correlation coefficients and linear regression analysis. In the validation group, the agreement between the estimated and real LS values was evaluated using a Bland-Altman plot. Results ElastQ Imaging had higher applicability (94.0% vs. 78.3%, P

OBJECTIVES The aim of this study was to investigate the clinical feasibility of the simultaneous reduction of radiation and contrast doses using spectral computed tomography (CT) in patients at high-risk for hepatocellular carcinoma. MATERIALS AND METHODS Between May 2017 and March 2018, this prospective study recruited participants at risk of hepatocellular carcinoma with body mass indexes less than 30 and randomly assigned them to either the standard-dose group or the double low-dose group, which targeted 30% reductions in both radiation and contrast media (NCT03045445). Lesion conspicuity as a primary endpoint and lesion detection rates were then compared between hybrid iterative reconstruction (iDose) images of standard-dose group and low monoenergetic (50 keV) images of double low-dose group. Qualitative and quantitative image noise and contrast were also compared between the 2 groups. Participants and reviewers were blinded for scan protocols and reconstruction algorithms. Lesion conspicuity was analyzed using generalized estimating equation analysis. Lesion detection was evaluated using weighted jackknife alternative free-response receiver operating characteristic analysis. RESULTS Sixty-seven participants (male-to-female ratio, 59:8; mean age, 64 ± 9 years) were analyzed. Compared with the standard-dose group (n = 32), significantly lower CTDIvol (8.8 ± 1.7 mGy vs 6.1 ± 0.6 mGy) and contrast media (116.9 ± 15.7 mL vs 83.1 ± 9.9 mL) were utilized in the double low-dose group (n = 35; P < 0.001). Comparative analysis demonstrated that lesion conspicuity was significantly higher on 50 keV images of double low-dose group than on iDose images of standard dose on both arterial (2.62 [95% confidence interval (CI), 2.31-2.93] vs 2.02 [95% CI, 1.73-2.30], respectively, P = 0.004) and portal venous phases (2.39 [95% CI, 2.11-2.67] vs 1.88 [95% CI, 1.67-2.10], respectively, P = 0.005). No differences in lesion detection capability were observed between the 2 groups (figure of merit: 0.63 in standard-dose group; 0.65, double low-dose group; P = 0.52). Fifty kiloelectronvolt images of double low-dose group showed better subjective image noise and contrast than iDose image of standard-dose group on arterial and portal venous phases (P < 0.001 for all). Contrast-to-noise ratio of the aorta and portal vein was also higher in double low-dose group than in standard-dose group (P < 0.001 for all), whereas there was no significant difference of quantitative image noise between the 2 groups on arterial and portal phases (P = 0.4~0.5). CONCLUSIONS Low monoenergetic spectral CT images (50 keV) can provide better focal liver lesion conspicuity than hybrid iterative reconstruction image of standard-dose CT in nonobese patients while using lower radiation and contrast media doses.

To investigate the diagnostic performance of liver stiffness (LS) measurements on two-dimensional (2D) shear wave elastography (SWE) for the assessment of hepatic fibrosis using LS measurements on MR elastography (MRE) as the reference standard and the prediction of clinically significant portal hypertension (CSPH).In this prospective study, 101 patients with chronic liver disease or cirrhosis underwent both MRE and SWE. After exclusion of technical failure on MRE (n = 5), technical failure/unreliable measurement on SWE (n = 4), LS measurements obtained on SWE with the aid of propagation maps were correlated with those of the MRE using Pearson's correlation analysis. Diagnostic performances for significant fibrosis (≥F2: MRE of ≥2.99 kPa) or cirrhosis (F4: MRE of ≥3.63 kPa) and for the prediction of CSPH were assessed using receiver operating characteristics (ROC) curve analysis.LS values on SWE showed a strong correlation with those on MRE (r = 0.846, P0.001). For the diagnosis of significant fibrosis or cirrhosis in patients with hepatitis B virus-related liver disease (n = 75), SWE showed areas under the ROC curves (AUC) of 0.975 and 0.912, respectively (95% confidence interval [CI], 0.910-997, and 0.824-0.965). For the prediction of CSPH, the AUC of SWE was 0.818 (95% CI, 0.712-0.898), and when an LS value of 11.5 kPa was applied as a cut-off, SWE showed a sensitivity of 81.5% and a specificity of 72.9%.LS measurements on 2D SWE were demonstrated to be well correlated with those obtained with MRE, and thus, may provide good diagnostic performance for the prediction of hepatic fibrosis and the presence of CSPH.

Objective To determine the prognostic value of MRI-based tumor regression grading (mrTRG) in rectal cancer compared with pathological tumor regression grading (pTRG), and to assess the effect of diffusion-weighted imaging (DWI) on interobserver agreement for evaluating mrTRG. Materials and methods Between 2007 and 2016, we retrospectively enrolled 321 patients (male:female = 208:113; mean age, 60.2 years) with rectal cancer who underwent both pre-chemoradiotherapy (CRT) and post-CRT MRI. Two radiologists independently determined mrTRG using a 5-point grading system with and without DWI in a one-month interval. Two pathologists graded pTRG using a 5-point grading system in consensus. Kaplan-Meier estimation and Cox-proportional hazard models were used for survival analysis. Cohen's kappa analysis was used to determine interobserver agreement. Results According to mrTRG on MRI with DWI, there were 6 mrTRG 1, 48 mrTRG 2, 109 mrTRG 3, 152 mrTRG 4, and 6 mrTRG 5. By pTRG, there were 7 pTRG 1, 59 pTRG 2, 180 pTRG 3, 73 pTRG 4, and 2 pTRG 5. A 5-year overall survival (OS) was significantly different according to the 5-point grading mrTRG (p = 0.024) and pTRG (p = 0.038). The 5-year disease-free survival (DFS) was significantly different among the five mrTRG groups (p = 0.039), but not among the five pTRG groups (p = 0.072). OS and DFS were significantly different according to post-CRT MR variables: extramural venous invasion after CRT (hazard ratio = 2.259 for OS, hazard ratio = 5.011 for DFS) and extramesorectal lymph node (hazard ratio = 2.610 for DFS). For mrTRG, k value between the two radiologists was 0.309 (fair agreement) without DWI and slightly improved to 0.376 with DWI. Conclusion mrTRG may predict OS and DFS comparably or even better compared to pTRG. The addition of DWI on T2-weighted MRI may improve interobserver agreement on mrTRG.

Purpose The purpose of this study was to prospectively investigate the intra- and inter-observer repeatability of a new 2-dimensional (2D) shear wave elastography (SWE) technique (S-Shearwave Imaging) for assessing liver fibrosis in chronic liver disease patients, and to compare liver stiffness measurements (LSMs) made using 2D-SWE with those made using point SWE (pSWE). Methods This prospective study received institutional review board approval and informed consent was obtained from all patients. Fifty-three chronic liver disease patients were randomly allocated to group 1 (for intra-observer repeatability [n=33]) or group 2 (for inter-observer repeatability [n=20]). In group 1, two 2D-SWE sessions and one pSWE sessions were performed by one radiologist. In group 2, one 2D-SWE session and one pSWE session were performed by the aforementioned radiologist, and a second 2D-SWE session was performed by another radiologist. The intraclass correlation coefficient (ICC) was used to assess intra- and inter-observer reliability. LSMs obtained using 2D-SWE and pSWE were compared and correlated using the paired t test and Pearson correlation coefficient, respectively. Results LSMs made using 2D-SWE demonstrated excellent intra- and inter-observer repeatability (ICC, 0.997 [95% confidence interval, 0.994 to 0.999]) and 0.995 [0.988 to 0.998], respectively). LSMs made using 2D-SWE were significantly different from those made using pSWE (2.1±0.6 m/sec vs. 1.9±0.6 m/sec, P

To evaluate the diagnostic value of deep learning model (DLM) reconstructed dual-energy CT (DECT) low-keV virtual monoenergetic imaging (VMI) for assessing hypoenhancing hepatic metastases.This retrospective study included 131 patients who underwent contrast-enhanced DECT (80-kVp and 150-kVp with a tin filter) in the portal venous phase for hepatic metastasis surveillance. Linearly blended images simulating 100-kVp images (100-kVp), standard 40-keV VMI images (40-keV VMI), and post-processed 40-keV VMI using a vendor-agnostic DLM (i.e., DLM 40-keV VMI) were reconstructed. Lesion conspicuity and diagnostic acceptability were assessed by three independent reviewers and compared using the Wilcoxon signed-rank test. The contrast-to-noise ratios (CNRs) were also measured placing ROIs in metastatic lesions and liver parenchyma. The detection performance of hepatic metastases was assessed by using a jackknife alternative free-response ROC method. The consensus by two independent radiologists was used as the reference standard.DLM 40-keV VMI, compared to 40-keV VMI and 100-kVp, showed a higher lesion-to-liver CNR (8.25 ± 3.23 vs. 6.05 ± 2.38 vs. 5.99 ± 2.00), better lesion conspicuity (4.3 (4.0-4.7) vs. 3.7 (3.7-4.0) vs. 3.7 (3.3-4.0)), and better diagnostic acceptability (4.3 (4.0-4.3) vs. 3.0 (2.7-3.3) vs. 4.0 (4.0-4.3)) (p0.001 for all). For lesion detection (246 hepatic metastases in 68 patients), the figure of merit was significantly higher with DLM 40-keV VMI than with 40-keV VMI (0.852 vs. 0.822, p = 0.012), whereas no significant difference existed between DLM 40-keV VMI and 100-kVp (0.852 vs. 0.842, p = 0.31).DLM 40-keV VMI provided better image quality and comparable diagnostic performance for detecting hypoenhancing hepatic metastases compared to linearly blended images.• DLM 40-keV VMI provides a superior image quality compared with 40-keV or 100-kVp for assessing hypoenhancing hepatic metastasis. • DLM 40-keV VMI has the highest CNR and lesion conspicuity score for hypoenhancing hepatic metastasis due to noise reduction and structural preservation. • DLM 40-keV VMI provides higher lesion detectability than standard 40-keV VMI (p = 0.012).

Introduction: Small-duct (SD) and large-duct (LD) subtypes of cholangiocarcinoma have been investigated for their prognostic factors. This study aimed to evaluate the diagnostic value of liver magnetic resonance imaging (MRI) in differentiating SD and LD types of intrahepatic cholangiocarcinoma (iCCA) and its prognostic value in predicting survival outcomes. Methods: One hundred forty patients with surgically confirmed iCCAs (93 SD type and 47 LD type) who had available preoperative gadoxetic acid-enhanced liver MR images were retrospectively included. MRI features suggestive of the LD type over the SD type were analyzed using multivariate logistic analyses. Postoperative recurrence-free survival (RFS) and overall survival (OS) for 107 patients with available survival data were compared according to MRI features. Results: MRI features suggestive of the LD type included infiltrative contour (odds ratio [OR] 14.2, 95% confidence interval [CI]: 2.5–81.7, p = 0.003), diffuse biliary dilatation (OR 9.7, 95% CI: 1.2–76.9, p = 0.032), no arterial phase hyperenhancement (OR 17.8, 95% CI: 2.7–118.6, p = 0.003), and vascular invasion (OR 4.5, 95% CI: 1.3–15.4, p = 0.018). When two or more features were combined, sensitivity was 59.6% (28/47), and specificity was 95.7% (89/93) in discriminating the LD type. RFS/OS was significantly shorter in patients with two or more MRI features, compared to those with none or one (310 days vs. 529 days, p = 0.011/964 days vs. 2,023 days, p = 0.010). Conclusions: Preoperative liver MRI may help predict the pathological subtype of iCCAs as either the SD type or LD type, allowing preoperative identification of patients with poorer survival outcomes.

Evaluating the performance of free-breathing dynamic T1-weighted imaging (T1WI) using compressed sensing golden-angle radial sparse parallel imaging (CS-GRASP) in non-cooperative patients compared with a general group.This retrospective study included patients who underwent gadoxetic acid-enhanced liver MRI using CS-GRASP at 3 T between March 2018 and October 2019. Patients were divided chronologically, into one of two groups: Group 1, who underwent MRI during the sequence implementation period regardless of breath-hold capability; and Group 2, who underwent MRI from June 2018 due to limited breath-hold capability. Three radiologists evaluated motion and streak artifacts as well as overall image quality on a four-point scale at the precontrast phase, late arterial phase (LAP) and portal venous phase (PVP). Intra-individual comparisons were made between sequences in each group.We identified 102 patients, who were divided into either Group 1 (n = 41) or 2 (n = 61). For the LAP, the former group had higher image quality (3.22 ± 0.65 vs. 2.95 ± 0.61, P 0.001) and less streak artifact (2.96 ± 0.56 vs. 2.74 ± 0.57, P = 0.001) than the latter. However, there was no significant difference between the two groups regarding either the proportion of patients with acceptable motion artifact, at 92.7% (38/41) for Group 1 vs. 96.7% (59/61) for Group 2, or that of patients with acceptable image quality at 80.5% (33/41) for Group 1 vs. 65.6% (40/61) for Group 2 (P 0.05). In intra-individual comparisons, portal phase showed the highest image quality than the others in both groups (P 0.001).Acceptable image quality for the LAP in non-cooperative patients was provided with a success rate of over 50% via free-breathing T1WI using CS-GRASP.

To investigate clinical applicability of deep learning(DL)-based reconstruction of virtual monoenergetic images(VMIs) of arterial phase liver CT obtained by rapid kVp-switching dual-energy CT for evaluation of hypervascular liver lesions.We retrospectively included 109 patients who had available late arterial phase liver CT images of the liver obtained with a rapid switching kVp DECT scanner for suspicious intra-abdominal malignancies. Two VMIs of 70 keV and 40 keV were reconstructed using adaptive statistical iterative reconstruction (ASiR-V) for arterial phase scans. VMIs at 40 keV were additionally reconstructed with a vendor-agnostic DL-based reconstruction technique (ClariCT.AI, ClariPi, DL 40 keV). Qualitative, quantitative image quality and subjective diagnostic acceptability were compared according to reconstruction techniques.In qualitative analysis, DL 40 keV images showed less image noise (4.55 vs 3.11 vs 3.95, p 0.001), better image sharpness (4.75 vs 4.16 vs 4.3, p 0.001), better image contrast (4.98 vs 4.72 vs 4.19, p 0.017), better lesion conspicuity (4.61 vs 4.23 vs 3.4, p 0.001) and diagnostic acceptability (4.59 vs 3.88 vs 4.09, p 0.001) compared with ASiR-V 40 keV or 70 keV image sets. In quantitative analysis, DL 40 keV significantly reduced image noise relative to ASiR-V 40 keV images (49.9%, p 0.001) and ASiR-V 70 keV images (85.2%, p = 0.012). DL 40 keV images showed significantly higher CNRDL-based reconstruction of 40 keV images using vendor-agnostic software showed greater noise reduction, better lesion conspicuity, image contrast, image sharpness, and higher overall image diagnostic acceptability than ASiR for 40 keV or 70 keV images in patients with hypervascular liver lesions.

Purpose: This study aimed to assess the inter-platform reproducibility of ultrasound attenuation examination in patients with nonalcoholic fatty liver disease (NAFLD).Methods: Between March 2021 and April 2021, patients with clinically suspected or known NAFLD were prospectively enrolled; each patient underwent ultrasound attenuation examinations with three different platforms (Attenuation Imaging [ATI], Canon Medical System; Tissue Attenuation Imaging [TAI], Samsung Medison; and Ultrasound-Guided Attenuation Parameter [UGAP], GE Healthcare) on the same day. The mean attenuation coefficient (AC) values of the three platforms were compared using repeated-measures analysis of variance with the Bonferroni correction. To evaluate inter-platform reproducibility, the AC values obtained for each platform were compared using Bland-Altman analysis with the calculation of 95% limits of agreement (LOA), intraclass correlation coefficients (ICCs), and coefficients of variation (CVs).Results: Forty-six patients (23 men; mean age±standard deviation, 52.3±12.4 years) were enrolled. The mean AC values showed significant differences among the three platforms (0.75±0.12, 0.80±0.11, and 0.74±0.09 dB/cm/MHz for ATI, TAI, and UGAP, respectively; P

To compare the overall image quality and detectability of significant (malignant and pre-malignant) liver lesions of low-dose liver CT (LDCT, 33.3% dose) using deep learning denoising (DLD) to standard-dose CT (SDCT, 100% dose) using model-based iterative reconstruction (MBIR).In this retrospective study, CT images of 80 patients with hepatic focal lesions were included. For noninferiority analysis of overall image quality, a margin of - 0.5 points (scored in a 5-point scale) for the difference between scan protocols was pre-defined. Other quantitative or qualitative image quality assessments were performed. Additionally, detectability of significant liver lesions was compared, with 64 pairs of CT, using the jackknife alternative free-response ROC analysis, with noninferior margin defined by the lower limit of 95% confidence interval (CI) of the difference of figure-of-merit less than - 0.1.The mean overall image quality scores with LDCT and SDCT were 3.77 ± 0.38 and 3.94 ± 0.34, respectively, demonstrating a difference of - 0.17 (95% CI: - 0.21 to - 0.12), which did not cross the predefined noninferiority margin of - 0.5. Furthermore, LDCT showed significantly superior quantitative results of liver lesion contrast to noise ratio (p 0.05). However, although LDCT scored higher than the average score in qualitative image quality assessments, they were significantly lower than those of SDCT (p 0.05). Figure-of-merit for lesion detection was 0.859 for LDCT and 0.878 for SDCT, showing noninferiority (difference: - 0.019, 95% CI: - 0.058 to 0.021).LDCT using DLD with 67% radiation dose reduction showed non-inferior overall image quality and lesion detectability, compared to SDCT.• Low-dose liver CT using deep learning denoising (DLD), at 67% dose reduction, provided non-inferior overall image quality compared to standard-dose CT using model-based iterative reconstruction (MBIR). • Low-dose CT using DLD showed significantly less noise and higher CNR

Background Few studies have reported on the diagnostic performance of Liver Imaging Reporting and Data System (LI-RADS) LR-5 or LR-5 V in the diagnosis of hepatocellular carcinoma (HCC) using MRI with gadoxetate disodium. Purpose To determine the diagnostic performance of LI-RADS version 2018 (hereafter, v2018) on gadoxetate disodium-enhanced MRI in comparison with LI-RADS version 2017 (hereafter, v2017) for the diagnosis of HCC in patients with cirrhosis or chronic hepatitis B viral infection or at high risk for HCC. Materials and Methods This retrospective study between January 2013 and October 2015 evaluated consecutive patients at high risk for HCC who had at least one observation of 10 mm or greater on gadoxetate disodium-enhanced MRI and no history of previous treatment for hepatic lesions. MRI features were reviewed by three radiologists. Observations were categorized according to LI-RADS v2018 and LI-RADS v2017. Per-observation sensitivity and specificity of LR-5 using LI-RADS v2017 and v2018 were compared using generalized estimating equation models. Results A total of 422 observations, including 234 HCCs confirmed by results of pathologic examination in 387 patients (305 men and 82 women; mean age ± standard deviation, 59 years ± 10), were included. In all observations, LI-RADS v2018 provided higher sensitivity than LI-RADS v2017 (81% [189 of 234] vs 68% [160 of 234], respectively; P < .001). In small observations (10-19 mm), LI-RADS v2018 yielded much higher sensitivity than LI-RADS v2017 (76% [34 of 45] vs 11% [five of 45], respectively; P < .001) with relatively little impairment of specificity (94% [121 of 128] vs 99% [127 of 128], respectively; P = .013). Conclusion Updated LR-5 criteria of Liver Imaging Reporting and Data System (LI-RADS) version 2018 on gadoxetate disodium-enhanced MRI can improve sensitivity in the diagnosis of small hepatocellular carcinomas (10-19 mm) with only slight impairment in specificity compared with the criteria of LI-RADS version 2017. © RSNA, 2019 Online supplemental material is available for this article.

Purpose The purpose of this study was to evaluate the intra-observer reproducibility of ultrasound attenuation imaging (ATI) for the noninvasive assessment of hepatic steatosis in patients with suspected hepatic steatosis and the inter-observer reproducibility in asymptomatic volunteers. Methods This prospective study was approved by our institutional review board and informed consent was obtained from all patients. In group 1, composed of patients with suspected hepatic steatosis (n=143), one abdominal radiologist performed gray-scale ultrasonography and two sessions of ATI. In group 2, composed of healthy volunteers (n=18), three independent sessions of ATI were performed by three abdominal radiologists. The visual degree of hepatic steatosis in all study subjects was graded on a 4-point scale by two independent reviewers using gray-scale ultrasonography. Thereafter, the attenuation coefficient (AC) was correlated with the degree of hepatic steatosis using Spearman rank correlation analysis. Intra-class correlation coefficients (ICCs) were used to assess the intra-observer (group 1) and inter-observer reproducibility (group 2) of ATI measurements. Results For the intra-observer reproducibility of ATI, the ICC was 0.929 (95% confidence interval [CI], 0.901 to 0.949), and the coefficient of variation was 7.1%. Inter-observer reproducibility of ATI measurements showed an ICC of 0.792 (95% CI, 0.549 to 0.916). The AC showed a significant correlation with the visual grade of hepatic steatosis for both reviewers (rho, 0.780 and 0.695; P

Purpose The purpose of this study was to retrospectively compare the technical success and reliability of the measurements made using two 2-dimensional (2D) shear wave elastography (SWE) systems using the comb-push technique from the same manufacturer and to assess the intersystem reproducibility of the resultant liver stiffness (LS) measurements. Methods Ninety-four patients with suspected chronic liver diseases were included in this retrospective study. LS measurements were obtained using two 2D-SWE systems (LOGIQ E9 and LOGIQ S8) from the same manufacturer, with transient elastography (TE) serving as the reference standard, on the same day. The technical success rates and reliability of the measurements of the two 2D-SWE systems were compared. LS values measured using the two 2D-SWE systems and TE were correlated using Spearman correlation coefficients and 95% Bland-Altman limits of agreement. Thereafter, Bland-Altman limits of agreement and intraclass correlation coefficients (ICCs) were used to analyze the intersystem reproducibility of LS measurements. Results The two 2D-SWE systems showed similar technical success rates (98.9% for both) and reliability of LS measurements (92.3% for the LOGIQ E9, 91.2% for the LOGIQ S8; P=0.185). Despite the excellent correlation (ICC=0.92), the mean LS measurements obtained by the two 2D-SWE systems were significantly different (LOGIQ E9, 6.57±2.33 kPa; LOGIQ S8, 6.90±6.64 kPa; P=0.018). Conclusion Significant intersystem variability was observed in the LS measurements made using the two 2D-SWE systems. Therefore, even 2D-SWE systems from the same manufacturer should not be used interchangeably in longitudinal follow-up.

The purpose of our study was to investigate the diagnostic performance of 2-D ultrasound attenuation imaging (ATI) for the assessment of hepatic steatosis in patients with chronic liver disease using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard. We prospectively analyzed 87 patients with chronic liver disease who had reliable measurements at both ATI and MRI-PDFF. For the detection of hepatic steatosis of MRI-PDFF ≥5% and MRI-PDFF ≥10%, ATI measurements yielded areas under the receiver operating characteristic curve of 0.76 and 0.88, respectively (95% confidence intervals: 0.66–0.85 and 0.79–0.94). Attenuation coefficients at ATI were moderately correlated with MRI-PDFF (ρ = 0.66). In conclusion, attenuation coefficients at ultrasound ATI were well correlated with MRI-PDFF and, thus, may provide good diagnostic performance in the assessment of hepatic steatosis, making these coefficients a promising tool for the non-invasive assessment and quantification of hepatic steatosis.

To validate the performance of 3T spin-echo echo-planar imaging (SE-EPI) magnetic resonance elastography (MRE) for staging hepatic fibrosis in a large population, using surgical specimens as the reference standard.This retrospective study initially included 310 adults (155 undergoing hepatic resection and 155 undergoing donor hepatectomy) with histopathologic results from surgical liver specimens. They underwent 3T SE-EPI MRE ≤ 3 months prior to surgery. Demographic findings, underlying liver disease, and hepatic fibrosis pathologic stage according to METAVIR were recorded. Liver stiffness (LS) was measured by two radiologists, and inter-reader reproducibility was evaluated using the intraclass correlation coefficient (ICC). The mean LS of each fibrosis stage (F0-F4) was calculated in total and for each etiologic subgroup. Comparisons among subgroups were performed using the Kruskal-Wallis test and Conover post-hoc test. The cutoff values for fibrosis staging were estimated using receiver operating characteristic (ROC) curve analysis.Inter-reader reproducibility was excellent (ICC, 0.98; 95% confidence interval, 0.97-0.99). The mean LS values were 1.91, 2.41, 3.24, and 5.41 kPa in F0-F1 (n = 171), F2 (n = 26), F3 (n = 38), and F4 (n = 72), respectively. The discriminating cutoff values for diagnosing ≥ F2, ≥ F3, and F4 were 2.18, 2.71, and 3.15 kPa, respectively, with the ROC curve areas of 0.97-0.98 (sensitivity 91.2%-95.9%, specificity 90.7%-99.0%). The mean LS was significantly higher in patients with cirrhosis (F4) of nonviral causes, such as primary biliary cirrhosis (9.56 kPa) and alcoholic liver disease (7.17 kPa) than in those with hepatitis B or C cirrhosis (4.28 and 4.92 kPa, respectively). There were no statistically significant differences in LS among the different etiologic subgroups in the F0-F3 stages.The 3T SE-EPI MRE demonstrated high interobserver reproducibility, and our criteria for staging hepatic fibrosis showed high diagnostic performance. LS was significantly higher in patients with non-viral cirrhosis than in those with viral cirrhosis.

To investigate clinical and CT factors associated with local resectability in patients with nonmetastatic pancreatic cancers after neoadjuvant chemotherapy ± radiation therapy (CRT). This retrospective study included consecutive patients with nonmetastatic pancreatic cancers who underwent neoadjuvant CRT between June 2009 and June 2019. Tumor size, tumor-vascular contact with artery/vein, and local resectability categories (resectable, borderline resectable, or locally advanced) were assessed at baseline and post-CRT CT. Baseline and post-CRT carbohydrate antigen (CA) 19-9 levels were also assessed. Clinical or imaging features related to R0 resection were determined using logistic regression analysis. A total of 179 patients (mean age, 62.4 ± 9.3 years; 92 men) were included. After neoadjuvant CRT, 105 (58.7%) patients received R0 resection, while 74 (41.3%) did not. R0 resection rates were significantly different according to post-CRT CT resectability categories (p < 0.001): 82.8% (48/58), 70.1% (47/67), and 18.5% (10/54) for resectable, borderline resectable, and locally advanced disease, respectively. For post-CRT borderline resectable disease, ≥ 50% decrease in CA 19-9 was significantly associated with R0 resection (odds ratio (OR), 3.160; p = 0.02). For post-CRT locally advanced disease, small post-CRT tumor size ≤ 2 cm (OR, 9.668; p = 0.026) and decreased tumor-arterial contact (OR, 24.213; p = 0.022) were significantly associated with R0 resection. Post-CRT CT resectability categorization may be useful for the assessment of R0 resectability in patients with pancreatic cancer following neoadjuvant CRT. Additionally, ≥ 50% decrease in CA 19-9 was associated with R0 resection in post-CRT borderline resectable disease, while small post-CRT tumor size and decreased tumor-arterial contact were with locally advanced disease. • R0 resection rates following neoadjuvant chemotherapy ± radiation therapy (CRT) were 82.8%, 70.1%, and 18.5% in resectable, borderline resectable, and locally advanced disease, respectively, at post-CRT CT (p < 0.001). • For post-CRT borderline resectable disease, ≥ 50% decrease in carbohydrate antigen (CA) 19-9 was significantly associated with R0 resection. • For post-CRT locally advanced disease, small post-CRT tumor size ≤ 2 cm and decreased tumor-arterial contact were significantly associated with R0 resection.

To determine if golden-angle radial sparse parallel (GRASP) dynamic contrast-enhanced (DCE)-MRI allows simultaneous evaluation of perfusion and morphology in liver fibrosis.Participants who were scheduled for liver biopsy or resection were enrolled (NCT02480972). Images were reconstructed at 12-s temporal resolution for morphologic assessment and at 3.3-s temporal resolution for quantitative evaluation. The image quality of the morphologic images was assessed on a four-point scale, and the Liver Imaging Reporting and Data System score was recorded for hepatic observations. Comparisons were made between quantitative parameters of DCE-MRI for the different fibrosis stages, and for hepatocellular carcinoma (HCCs) with different LR features.DCE-MRI of 64 participants (male = 48) were analyzed. The overall image quality consistently stood at 3.5 ± 0.4 to 3.7 ± 0.4 throughout the exam. Portal blood flow significantly decreased in participants with F2-F3 (n = 18, 175 ± 110 mL/100 mL/min) and F4 (n = 12, 98 ± 47 mL/100 mL/min) compared with those in participants with F0-F1 (n = 34, 283 ± 178 mL/100 mL/min, p0.05 for all). In participants with F4, the arterial fraction and extracellular volume were significantly higher than those in participants with F0-F1 and F2-F3 (p0.05). Compared with HCCs showing non-LR-M features (n = 16), HCCs with LR-M (n = 5) had a significantly prolonged mean transit time and lower arterial blood flow (p0.05).Liver MRI using GRASP obtains both sufficient spatial resolution for confident diagnosis and high temporal resolution for pharmacokinetic modeling. Significant differences were found between the MRI-derived portal blood flow at different hepatic fibrosis stages.A single MRI examination is able to provide both images with sufficient spatial resolution for anatomic evaluation and those with high temporal resolution for pharmacokinetic modeling. Portal blood flow was significantly lower in clinically significant hepatic fibrosis and mean transit time and extracellular volume increased in cirrhosis, compared with those in no or mild hepatic fibrosis. HCCs with different LR features showed different quantitative parameters of DCE-MRI: longer mean transit time and lower arterial flow were observed in HCCs with LR-M features.

To compare the image quality and diagnostic performance of 2D MRCP to those of breath-hold 3D MRCP using compressed sensing (CS-MRCP) and gradient and spin-echo (GRASE-MRCP) at 3T.From January to November 2018, patients who underwent pancreatobiliary MRI including 2D MRCP and two breath-hold 3D MRCP using CS and GRASE at 3T were included. Three radiologists independently evaluated image quality, motion artifact, and pancreatic cyst conspicuity. Diagnostic performance was assessed for bile duct anatomic variation, bile duct, and pancreatic diseases using a composite algorithm as reference standards. Pancreatic lesion detectability and conspicuity were evaluated using JAFROC and generalized estimating equation analysis.One hundred patients (male = 50) were included. Bile duct anatomic variation, bile duct and pancreatic diseases were present in respectively 31, 15, and 79 patients. Breath-hold 3D MRCP provided better image quality than 2D MRCP (3.5 ± 0.6 in 2D MRCP; 4.0 ± 0.7 in GRASE-MRCP and 3.9 ± 0.8 in CS-MRCP, p0.001 for both). There was no difference in motion artifact between 2D and breath-hold 3D MRCP (p = 0.1). Breath-hold 3D CS-MRCP provided better pancreatic cyst conspicuity than 2D MRCP (2.7 [95% CI: 2.5-3.0] vs. 2.3 [95% CI: 2.1-2.5], p = 0.001). There were no significant differences between the diagnostic performance of the three sequences in the detection of bile duct anatomic variation or pancreatic lesions (p0.05).Breath-hold 3D MRCP with GRASE or CS can provide better image quality than 2D MRCP in a comparable scan time.• Breath-hold 3D MRCP using compressed sensing (CS) or gradient and spin-echo (GRASE) provided a better image quality with less image blurring than 2D MRCP. • There were no significant differences between 2D MRCP and breath-hold 3D MRCP in either motion artifact or the number of non-diagnostic exams. • There were no significant differences between 2D MRCP and either type of breath-hold 3D MRCP in the diagnosis of bile duct anatomic variation or detection of pancreatic lesions.

Introduction: A switching monopolar no-touch radiofrequency ablation (RFA) technique is used for small hepatocellular carcinoma (HCC); however, there have not been any randomized clinical trials comparing this technique to the conventional RFA technique. Objective:This study aims to compare the results of two RFA techniques, and to comparatively identify more effective methods to reduce the progression of local tumors associated with small HCC (≤2.5 cm). Methods: This prospective randomized clinical trial (NCT03375281) recruited a total of 116 participants (M:F, 93:23; 68.3 ± 8.4 years) between October 2016 and September 2017. The primary outcome was the cumulative incidence of local tumor progression (LTP) after RFA. Secondary outcomes included technical success rate, technique efficacy, and RFA procedure characteristics. Kaplan-Meier analysis and the Cox proportional hazard regression model were used. Results: The mean follow-up period was 24.1 months. A sufficient ablative margin was more frequently achieved in the no-touch RFA group (57/60 = 95%) than in the conventional RFA group (50/64 = 78.1%) on immediate follow-up CT (p = 0.01). The cumulative incidence of LTP in the no-touch RFA group was significantly lower than that in the conventional RFA group (p = 0.02). In multivariable analysis, no-touch RFA was the only predictive factor for LTP (p = 0.04, hazard ratio = 0.2, 95% confidence interval = 0.04–0.94). Conclusions: A switching monopolar no-touch RFA technique is a favorable treatment option and provides lower LTP after RFA compared with conventional RFA for small HCC.

To compare lesion conspicuity and image quality of arterial phase images obtained from low kVp (90-kVp) and dual-energy (DE) scans for the evaluation of hypervascular hepatocellular carcinoma (HCC).This retrospective study included 229 patients with HCC who underwent either 90 kVp (n = 106) or DE scan (80- and 150-kVp with a tin filter) (n = 123) during the arterial phase. DE scans were reconstructed into a linearly blended image with a mixed ratio of 0.6 (60% 80kVp and 40% 150 kVp) and post-processed for 40 keV and 50 keV images. The contrast-to-noise ratio (CNR) of HCC to the liver and image noise was measured. Lesion conspicuity, liver parenchymal image quality, and overall image preference were assessed qualitatively by three independent radiologists.DE 40 keV images had the highest CNR of HCC, and DE blended images had the lowest image noise among four image sets (p = 0.01 and p 0.001, respectively). There was no significant difference in mean volume CT dose index and dose-length product between DE and low kVp scan (ps 0.05). For qualitative analyses, DE blended images had the highest scores for image quality and overall image preference (ps 0.001).At an equal radiation dose, DE 40 keV showed higher CNR of HCC and DE blended image showed higher image quality and image preference compared with low kVp CT.

Background and Aims: Biannual ultrasonography (US) is a current recommendation for hepatocellular carcinoma (HCC) surveillance in a high-risk group. The sensitivity of US, however, has been low in patients with a high risk of developing HCC. We aimed to compare sensitivity for HCC of biannual US and two-phase low-dose computed tomography (LDCT) in patients with a high risk of HCC. Methods: In this prospective single-arm study, participants with an annual risk of HCC greater than 5% (based on a risk index of ≥2.33) and who did not have a history of HCC were enrolled from November 2014 to July 2016. Participants underwent paired biannual US and two-phase LDCT 1–3 times. Two-phase LDCT included arterial and 3-min delayed phases. The sensitivity, specificity, and positive predictive value of HCC detection using US and two-phase LDCT were compared using a composite algorithm as a standard of reference. Results: Of the 139 enrolled participants, 137 underwent both the biannual US and two-phase LDCT at least once and had follow-up images. Among them, 27 cases of HCC (mean size: 14 ± 4 mm) developed in 24 participants over 1.5 years. Two-phase LDCT showed a significantly higher sensitivity (83.3% [20/24] vs. 29.2% [7/24], p < 0.001) and specificity (95.6% [108/113] vs. 87.7% [99/113], p =0.03) than US. A false-positive result was reported in 14 participants at US and 5 participants at two-phase LDCT, resulting in a significantly higher positive predictive value of two-phase LDCT (33.3% [7/21] vs. 80% [20/25], p < 0.001). Conclusions: Patients with a risk index ≥2.33 showed a high annual incidence of HCC development in our study, and two-phase LDCT showed significantly higher sensitivity and specificity for HCC detection than US.

Background Perfluorobutane (PFB) and sulfur hexafluoride (SHF) have different physiologic characteristics, but it is unclear whether hepatocellular carcinomas (HCCs) show similar wash-in and washout patterns to both contrast agents at US. Purpose To investigate Contrast-Enhanced US Liver Imaging Reporting and Data System (LI-RADS) version 2017 HCC categorization by comparing PFB-enhanced US and SHF-enhanced US in participants at high risk for HCC. Materials and Methods In this prospective study conducted from February to August 2019, participants at high risk for HCC with treatment-naive hepatic observations (≥1 cm) categorized as LR-3, LR-4, LR-5, or LR-M (intermediate probability of HCC, probable HCC, definitely HCC, and probably malignant but not HCC specific, respectively) on cross-sectional images were screened. They underwent same-day PFB-enhanced US and SHF-enhanced US. Arterial phase hyperenhancement (APHE), washout time and degree, and echogenicity in the Kupffer phase (PFB-enhanced US) were evaluated and categorized by the operator using CEUS LI-RADS, who referred to the radiologist who performed the contrast-enhanced US, and by a reviewer. Diagnostic performance was analyzed using the McNemar test. Results Fifty-nine participants were evaluated (43 with HCC, 10 with non-HCC malignancies, six with benign findings). Nonrim APHE was identically observed in 95% (41 of 43, operator) or 88% (38 of 43, reviewer) of HCCs with both contrast agents. Among 43 HCCs, late (≥60 seconds) and mild washout were more frequent with PFB-enhanced US (34 with operator, 33 with reviewer) than with SHF-enhanced US (24 with operator, 26 with reviewer) (

OBJECTIVE To evaluate the performance of the 2018 Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) Practice Guidelines (hereafter, PG) for the diagnosis of hepatocellular carcinoma (HCC) using gadoxetic acid-enhanced MRI, compared to the Liver Imaging-Reporting and Data System (LI-RADS) version 2018 (hereafter, v2018). MATERIALS AND METHODS From January 2013 to October 2015, treatment-naive hepatic lesions (≥ 1 cm) on gadoxetic acid-enhanced MRI in consecutive patients with chronic hepatitis B or cirrhosis were retrospectively evaluated. For each lesion, three radiologists independently analyzed the imaging features and classified the lesions into categories according to the 2018 KLCA-NCC PG and LI-RADS v2018. The imaging features and categories were determined by consensus. Generalized estimating equation (GEE) models were used to compare the per-lesion diagnostic performance of the 2018 KLCA-NCC PG and LI-RADS v2018 using the consensus data. RESULTS In total, 422 lesions (234 HCCs, 45 non-HCC malignancies, and 143 benign lesions) from 387 patients (79% male; mean age, 59 years) were included. In all lesions, the definite HCC (2018 KLCA-NCC PG) had a higher sensitivity and lower specificity than LR-5 (LI-RADS v2018) (87.2% [204/234] vs. 80.8% [189/234], p < 0.001; 86.2% [162/188] vs. 91.0% [171/188], p = 0.002). However, in lesions of size ≥ 2 cm, the definite HCC had a higher sensitivity than the LR-5 (86.8% [164/189] vs. 82.0 (155/189), p = 0.002) without a reduction in the specificity (80.0% [48/60] vs. 83.3% [50/60], p = 0.15). In all lesions, the sensitivity and specificity of the definite/probable HCC (2018 KLCA-NCC PG) and LR-5/4 did not differ significantly (89.7% [210/234] vs. 91.5% [214/234], p = 0.204; 83.5% [157/188] vs. 79.3% [149/188], p = 0.071). CONCLUSION For the diagnosis of HCC of size ≥ 2 cm, the definite HCC (2018 KLCA-NCC PG) had a higher sensitivity than LR-5, without a reduction in specificity. The definite/probable HCC (2018 KLCA-NCC PG) had a similar sensitivity and specificity to that those of the LR-5/4.

To compare the diagnostic performances of first and second portal venous phases (PVP1 and PVP2) in revealing washout and capsule appearance for non-invasive HCC diagnoses in gadoxetic acid-enhanced MRI (Gd-EOB-MRI).This retrospective study included 123 at-risk patients with 160 hepatic observations (HCCs, n = 116; non-HCC malignancies, n = 18; benign, n = 26) showing arterial phase hyper-enhancement (APHE) ≥ 1 cm at Gd-EOB-MRI. The mean time intervals from gadoxetic acid injection to PVP1 and PVP2 acquisitions were 53 ± 2 s and 73 ± 3 s, respectively. After evaluating image findings independently, imaging findings and diagnoses were finalized by a consensus of two radiologists using either PVP1 or PVP2 image sets according to the LI-RADS v2018 or EASL criteria. Sensitivity, specificity, and accuracy were compared.Among HCCs, more washout and enhancing capsule were observed in PVP2 (83.6% and 27.6%) than in PVP1 (50.9% and 19.8%) (p 0.001, both). The PVP2 set presented significantly higher sensitivity (83.6% vs. 53.5%, LI-RADS; 82.8% vs. 50.0%, EASL; p 0.001, both) and accuracy (0.88 vs. 0.73, LI-RADS; 0.88 vs. 0.72, EASL; p 0.001, both) than the PVP1 set without significant specificity loss (93.2% vs. 93.2%, by LI-RADS or EASL; p = 0.32, both). None of the non-HCC malignancy was non-invasively diagnosed as HCC in both PVP image sets.Late acquisition of PVP detected washout and enhancing capsule of HCC more sensitively than early acquisition, enabling accurate diagnoses of HCC, according to LI-RADS or EASL criteria.• Among HCCs, more washout and enhancing capsules were observed in PVP2 than PVP1, quantitatively and qualitatively. • The portal venous phase acquired at around 70 s after contrast media administration (PVP2) provided significantly higher sensitivity and AUC value than PVP1 by using LI-RADS v2018 or EASL criteria. • More HCCs were categorized as LR-5 in PVP2 than in PVP1 images, and the specificity of PVP2 (93.5%) was comparable with PVP1 (93.5%).

BACKGROUND Tumor stiffness (TS), measured by magnetic resonance elastography (MRE), could be associated with tumor mechanical properties and tumor grade. PURPOSE To determine whether TS obtained using MRE is associated with survival in patients with single nodular hepatocellular carcinoma (HCC) after hepatic resection (HR). STUDY TYPE Retrospective. POPULATION In all, 95 patients with pathologically confirmed HCCs. FIELD STRENGTH/SEQUENCE 1.5T/3D spin-echo echo-planar imaging MRE. ASSESSMENT TS values of the whole tumor (TS-WT) and of a solid portion of the tumor (TS-SP) after excluding the necrotic area were measured on stiffness maps. Known imaging prognostic factors of HCC were also analyzed. After surgery, pathologic findings were evaluated from resected pathology specimens. STATISTICAL TESTS Fisher's exact test and the Mann-Whitney U-test were performed to determine the significance of differences according to the tumor grade. Overall survival (OS) / recurrence-free survival (RFS) analyses were performed using Kaplan-Meier analyses and Cox multivariable models. RESULTS The average TS-WT was 2.14 ± 0.74 kPa, and the average TS-SP was 2.51 ± 1.07 kPa. The cumulative incidence of RFS was 73.1%, 63.1%, and 57.3% at 1, 3, and 5 years, respectively. The TS-WT, TS-SP, and tumor size (≥5 cm) were significant prognostic factors for RFS (P

Purpose This study investigated whether the use of ultrasound (US) guidance in transient elastography (TE) improved the technical success and reliability of liver stiffness (LS) measurements and whether 2-dimensional (2D) shear wave elastography (SWE) provided reliable LS measurements if TE measurements failed. Methods In this prospective study, 292 participants (male:female, 189:103; median age, 60 years) with chronic liver disease (CLD) were enrolled. LS was measured via the consecutive use of conventional TE, 2D-SWE, and US-guided TE. The technical success rates and reliable LS measurement rates of the three elastography techniques were compared. The risk factors for TE failure were assessed through univariate and multivariate logistic regression models. Results US-guided TE was associated with a higher technical success rate (281 of 292, 96.2%) and a higher reliable measurement rate (266 of 292, 91.1%) than conventional TE (technical success: 256 of 292, 87.7%; reliable measurements: 231 of 292, 79.1%; P

To evaluate the diagnostic performance of whole-body MRI (WB-MRI) including contrast-enhanced T1-weighted imaging (T1WI) and WB-DWI in rectal cancer initial staging.This retrospective study was approved by the IRB and the requirement of informed consent was waived. From September 2013 to Feb 2015, patients who underwent rectal MRI including WB-MRI, as well as chest and abdominopelvic CT for initial staging, were included. WB-MRI consisted of contrast-enhanced T1-weighted imaging and DWI covering neck to the pelvis. Three radiologists reviewed WB-MRI and CECT independently for the M-classification. The diagnostic performance of CECT and WB-MRI was compared using a reference standard incorporating histology, FDG-PET results, and clinical follow-up.A total of 139 patients (male:female = 89:50, mean age 63.2 ± 12.4 years) were included and metastasis was observed in 15.2% (21/139). WB-MRI showed significantly higher specificity (96.7% [114/118] vs. 85.6% [101/118], p = 0.001) and positive predictive value (PPV) (80% [16/20] vs. 48.5% [16/33], p 0.001) than CECT. However, there were no significant differences in sensitivity (76.2% [16/21] for both, p 0.99) and negative predictive value (95.3% [101/106] at CECT vs. 95.8% [114/119] at WB-MRI, p = 0.77) between CECT and WB-MRI.WB-MRI showed higher specificity and PPV than CECT in newly diagnosed rectal cancer. Adding WB-MRI to standard rectal MRI is a feasible option for initial staging workup of rectal cancer.• WB-MRI showed a higher specificity and PPV than those of CECT for identifying metastasis at initial staging workup of rectal cancer. • WB-MRI and CECT did not show a significant difference in sensitivity and NPV for the M-classification. • WB-MRI can be used as an alternative to CECT for the initial M-classification modality in newly diagnosed rectal cancer.

BackgroundThe performance of PET/MRI in the determination of distant metastases (M stage) in rectal cancer relative to the current practice with contrast material-enhanced CT is largely unknown.PurposeTo compare the staging of clinical M stage rectal cancer with fluorine 18 fluorodeoxyglucose (FDG) PET/MRI (including dedicated liver and rectal MRI) to that of chest and abdominopelvic CT and dedicated rectal MRI.Materials and MethodsFrom January 2016 to August 2017, patients with newly diagnosed advanced mid to low rectal cancers were recruited for this prospective study (clinicaltrials.gov identifier: NCT0265170). Participants underwent both FDG PET/MRI with dedicated liver and rectal MRI and chest and abdominopelvic CT (the standard-of-care protocol) within 3 weeks of each other. Thereafter, M stage assessment performance was determined by using findings from 6-month clinical follow-up or biopsy as the reference standard. Performance was compared between protocols. Agreement in M stage classification was also assessed. Nonparametric statistical analyses were performed, and P .99).ConclusionPET/MRI with dedicated rectal and liver MRI can facilitate the staging work-up of newly diagnosed advanced rectal cancers by helping assess indeterminate lesions, metastases, and incidental findings better than contrast-enhanced CT, obviating for additional imaging work-up.© RSNA, 2019Online supplemental material is available for this article.Clinical trial registration no. NCT02651701.