CT findings and clinical effects of high grade pancreatic intraepithelial neoplasia in patients with intraductal papillary mucinous neoplasms

PURPOSE

To investigate the common CT findings of high-grade (HG) PanIN and clinical effects in the remnant pancreas in patients with intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

MATERIALS AND METHODS

Two hundred fifty-one patients with surgically confirmed IPMNs (118 malignant [invasive carcinoma/high-grade dysplasia] and 133 benign [low-grade dysplasia]) were retrospectively enrolled. The grade of PanIN (233 absent/low-grade and 18 high-grade) was recorded, and all patients underwent serial CT follow-up before and after surgery. Two radiologists analyzed CT findings of high-risk stigmata or worrisome features according to 2017 international consensus guidelines. They also analyzed tumor recurrence on serial follow-up CT after surgery. Statistical analyses were performed to identify significant predictors and clinical impact on postoperative outcomes of HG PanIN.

RESULTS

PanIN grade showed a significant association with IPMN grade (p = 0.012). Enhancing mural nodules ≥5 mm, abrupt main pancreatic duct (MPD) changes with distal pancreatic atrophy, increased mural nodule size and MPD diameter were common findings in HG PanIN (P<0.05). In multivariate analysis, abrupt MPD change with distal pancreatic atrophy (odds ratio (OR) 6.59, 95% CI: 2.32-18.72, <0.001) and mural nodule size (OR, 1.05; 95% CI, 1.02-1.08, 0.004) were important predictors for HG PanIN. During postoperative follow-up, HG PanIN (OR, 4.98; 95% CI, 1.22-20.33, 0.025) was significantly associated with cancer recurrence in the remnant pancreas.

CONCLUSION

CT can be useful for predicting HG PanIN using common features, such as abrupt MPD changes and mural nodules. In HG PanIN, extra caution is needed to monitor postoperative recurrence during follow-up.

Contrast-Enhanced Ultrasound With Perfluorobutane for Hepatocellular Carcinoma Diagnosis: Comparison of Imaging Phases and Diagnostic Criteria

BACKGROUND. Contrast-enhanced ultrasound (CEUS) with perfluorobutane has used varying protocols and diagnostic criteria for hepatocellular carcinoma (HCC). OBJECTIVE. The purpose of this article was to assess diagnostic performance for HCC of CEUS with perfluorobutane in high-risk patients using various criteria. METHODS. This retrospective post hoc study evaluating individual patient data from three earlier prospective studies from one hospital included 204 patients (136 men, 68 women; mean age, 63 ± 11 [SD] years) at high risk of HCC with 213 liver observations. Patients underwent CEUS using perfluorobutane from March 2019 to June 2022. Three radiologists (the examination's operator and two subsequent reviewers) independently interpreted examinations, assessing arterial, portal venous (arterial phase completion through 2 minutes), transitional (2-5 minutes after injection), and Kupffer (≥ 10 minutes after injection) phase findings. Six criteria for HCC were tested: 1, any arterial phase hyperenhancement (APHE) with Kupffer phase hypoenhancement; 2, nonrim APHE with Kupffer phase hypoenhancement; 3, nonrim APHE with portal venous washout; 4, nonrim APHE with portal venous washout and/or Kupffer phase hypoenhancement; 5, nonrim APHE with portal venous and/or transitional washout; 6, nonrim APHE with any of portal venous washout, transitional washout, or Kupffer phase hypoenhancement. Depending on the criteria, observations were instead deemed to be a non-HCC malignancy if showing rim APHE, early washout (at < 1 minute), or marked washout (at 2 minutes). Reference was pathology for malignant observations and pathology or imaging follow-up for benign observations. Diagnostic performance was assessed, pooling readers' data. RESULTS. Criterion 1 (no recognized features of non-HCC malignancy) had highest sensitivity (86.9%) but lowest specificity (43.2%) for HCC. Compared with nonrim APHE and portal venous washout (criterion 3), the addition of Kupffer phase hypoenhancement (criterion 4), transitional washout (criterion 5), or either feature (criterion 6) significantly increased sensitivity (34.4% vs 62.6-64.2%) and accuracy (61.8% vs 75.1-76.5%), but significantly decreased specificity (98.5% vs 91.9-94.1%). Criteria 2, 4, 5, and 6 (all incorporating transitional washout and/or Kupffer phase hypoenhancement) showed no significant differences in sensitivity (62.6-64.2%), specificity (91.9-94.1%), or accuracy (75.1-76.5%). CONCLUSION. Recognition of features of non-HCC malignancy improved specificity for HCC. Incorporation of the findings of transitional washout and/or Kupffer phase hypoenhancement improved sensitivity and accuracy, albeit lowered specificity, versus arterial and portal venous findings alone, without further performance variation among criteria incorporating those two findings. CLINICAL IMPACT. Kupffer phase acquisition may be optional for observations classified as HCC or non-HCC malignancy by arterial, portal venous, and transitional phases.

Image Quality Improvement of Low-dose Abdominal CT using Deep Learning Image Reconstruction Compared with the Second Generation Iterative Reconstruction

BACKGROUND

Whether deep learning-based CT reconstruction could improve lesion conspicuity on abdominal CT when the radiation dose is reduced is controversial.

OBJECTIVES

To determine whether DLIR can provide better image quality and reduce radiation dose in contrast-enhanced abdominal CT compared with the second generation of adaptive statistical iterative reconstruction (ASiR-V).

AIMS

This study aims to determine whether deep-learning image reconstruction (DLIR) can improve image quality.

METHOD

In this retrospective study, a total of 102 patients were included, who underwent abdominal CT using a DLIR-equipped 256-row scanner and routine CT of the same protocol on the same vendor's 64-row scanner within four months. The CT data from the 256-row scanner were reconstructed into ASiR-V with three blending levels (AV30, AV60, and AV100), and DLIR images with three strength levels (DLIR-L, DLIR-M, and DLIR-H). The routine CT data were reconstructed into AV30, AV60, and AV100. The contrast-to-noise ratio (CNR) of the liver, overall image quality, subjective noise, lesion conspicuity, and plasticity in the portal venous phase (PVP) of ASiR-V from both scanners and DLIR were compared.

RESULTS

The mean effective radiation dose of PVP of the 256-row scanner was significantly lower than that of the routine CT (6.3±2.0 mSv vs. 2.4±0.6 mSv; p< 0.001). The mean CNR, image quality, subjective noise, and lesion conspicuity of ASiR-V images of the 256-row scanner were significantly lower than those of ASiR-V images at the same blending factor of routine CT, but significantly improved with DLIR algorithms. DLIR-H showed higher CNR, better image quality, and subjective noise than AV30 from routine CT, whereas plasticity was significantly better for AV30.

CONCLUSION

DLIR can be used for improving image quality and reducing radiation dose in abdominal CT, compared with ASIR-V.

Sonazoid-enhanced ultrasonography for noninvasive imaging diagnosis of hepatocellular carcinoma: special emphasis on the 2022 KLCA-NCC guideline

Contrast-enhanced ultrasonography (CEUS) is a noninvasive imaging modality used to diagnose hepatocellular carcinoma (HCC) based on specific imaging features, without the need for pathologic confirmation. Two types of ultrasound contrast agents are commercially available: pure intravascular agents (such as SonoVue) and Kupffer agents (such as Sonazoid). Major guidelines recognize CEUS as a reliable imaging method for HCC diagnosis, although they differ depending on the contrast agents used. The Korean Liver Cancer Association-National Cancer Center guideline includes CEUS with either SonoVue or Sonazoid as a second-line diagnostic technique. However, Sonazoid-enhanced ultrasound is associated with several unresolved issues. This review provides a comparative overview of these contrast agents regarding pharmacokinetic features, examination protocols, diagnostic criteria for HCC, and potential applications in the HCC diagnostic algorithm.

Perfluorobutane-Enhanced Ultrasound for Characterization of Hepatocellular Carcinoma From Non-hepatocellular Malignancies or Benignancy: Comparison of Imaging Acquisition Methods

OBJECTIVE

The aim of the work described here was to evaluate the diagnostic performance of perfluorobutane (PFB)-enhanced ultrasound in differentiating hepatocellular carcinoma (HCC) from non-HCC malignancies and other benign lesions using different acquisition methods.

METHODS

This prospective study included 69 patients with solid liver lesions larger than 1 cm who were scheduled for biopsy or radiofrequency ablation between September 2020 and March 2021. Lesion diagnosis was designated by three blinded radiologists after reviewing three different sets of acquired images selected according to the following presumed acquisition methods: (i) method A, acquisition up to 5 min after contrast injection; (ii) method B, acquisition up to 1 min after contrast injection with additional Kupffer phase; and (iii) method C, acquisition up to 5 min after contrast injection with additional Kupffer phase.

RESULTS

After excluding 7 technical failures, 62 patients with liver lesions (mean size: 24.2 ± 14.8 mm), which consisted of 7 benign lesions, 37 non-HCC malignancies and 18 HCCs. For the HCC diagnosis, method C had the highest sensitivity (75.9%), followed by method B (72.2%) and method A (68.5%), but failed to exhibit statistical significance (p = 0.12). There was no significant difference with respect to the pooled specificity between the three methods (p = 0.28). Diagnostic accuracy was the highest with method C (87.1%) but failed to exhibit statistical significance (p = 0.24).

CONCLUSION

Image acquisition up to 5 min after contrast injection with additional Kupffer phase could potentially result in high accuracy and sensitivity without loss of specificity in diagnosing HCC with PFB-enhanced ultrasound.

Comparison Between Contrast-Enhanced Computed Tomography and Contrast-Enhanced Magnetic Resonance Imaging With Magnetic Resonance Cholangiopancreatography for Resectability Assessment in Extrahepatic Cholangiocarcinoma

OBJECTIVE

To compare the diagnostic performance and interobserver agreement between contrast-enhanced computed tomography (CECT) and contrast-enhanced magnetic resonance imaging (CE-MRI) with magnetic resonance cholangiopancreatography (MRCP) for evaluating the resectability in patients with extrahepatic cholangiocarcinoma (eCCA).

MATERIALS AND METHODS

This retrospective study included treatment-naïve patients with pathologically confirmed eCCA, who underwent both CECT and CE-MRI with MRCP using extracellular contrast media between January 2015 and December 2020. Among the 214 patients (146 males; mean age ± standard deviation, 68 ± 9 years) included, 121 (56.5%) had perihilar cholangiocarcinoma. R0 resection was achieved in 108 of the 153 (70.6%) patients who underwent curative-intent surgery. Four fellowship-trained radiologists independently reviewed the findings of both CECT and CE-MRI with MRCP to assess the local tumor extent and distant metastasis for determining resectability. The pooled area under the receiver operating characteristic curve (AUC), sensitivity, and specificity of CECT and CE-MRI with MRCP were compared using clinical, surgical, and pathological findings as reference standards. The interobserver agreement of resectability was evaluated using Fleiss kappa (κ).

RESULTS

No significant differences were observed between CECT and CE-MRI with MRCP in the pooled AUC (0.753 vs. 0.767), sensitivity (84.7% [366/432] vs. 90.3% [390/432]), and specificity (52.6% [223/424] vs. 51.4% [218/424]) (P > 0.05 for all). The AUC for determining resectability was higher when CECT and CE-MRI with MRCP were reviewed together than when CECT was reviewed alone in patients with discrepancies between the imaging modalities or with indeterminate resectability (0.798 [0.754-0.841] vs. 0.753 [0.697-0.808], P = 0.014). The interobserver agreement for overall resectability was fair for both CECT (κ = 0.323) and CE-MRI with MRCP (κ = 0.320), without a significant difference (P = 0.884).

CONCLUSION

CECT and CE-MRI with MRCP showed no significant differences in the diagnostic performance and interobserver agreement in determining the resectability in patients with eCCA.

Diagnosing Hepatocellular Carcinoma Using Sonazoid Contrast-Enhanced Ultrasonography: 2023 Guidelines From the Korean Society of Radiology and the Korean Society of Abdominal Radiology

Sonazoid, a second-generation ultrasound contrast agent, was introduced for the diagnosis of hepatic nodules. To clarify the issues with Sonazoid contrast-enhanced ultrasonography for the diagnosis of hepatocellular carcinoma (HCC), the Korean Society of Radiology and Korean Society of Abdominal Radiology collaborated on the guidelines. The guidelines are de novo, evidence-based, and selected using an electronic voting system for consensus. These include imaging protocols, diagnostic criteria for HCC, diagnostic value for lesions that are inconclusive on other imaging results, differentiation from non-HCC malignancies, surveillance of HCC, and treatment response after locoregional and systemic treatment for HCC.

Effects of genomic estimated breeding value and dietary energy to protein ratio on growth performance, carcass trait, and lipogenic gene expression in Hanwoo steer

"Genome-based precision feeding" is a concept that involves the application of customised diets to different genetic groups of cattle. We investigated the effects of the genomic estimated breeding value (gEBV) and dietary energy to protein ratio (DEP) on growth performance, carcass traits, and lipogenic gene expression in Hanwoo (Korean cattle) steers. Forty-four Hanwoo steers (BW = 636 kg, age = 26.9 months) were genotyped using the Illumina Bovine 50 K BeadChip. The gEBV was calculated using genomic best linear unbiased prediction. Animals were separated into high gEBV of marbling score or low-gMS groups based on the upper and lower 50% groupings of the reference population, respectively. Animals were assigned to one of four groups in a 2 × 2 factorial arrangement: high gMS/high DEP (0.084 MJ/g), high gMS/low DEP (0.079 MJ/g), low gMS/high DEP, and low gMS/low DEP. Steers were fed concentrate with a high or low DEP for 31 weeks. The BW tended to be higher (0.05 < P < 0.1) in the high-gMS groups compared to the low-gMS groups at 0, 4, 8, 12, and 20 weeks. The average daily gain (ADG) tended to be lower (P = 0.08) in the high-gMS group than in the low-gMS group. Final BW and measured carcass weight (CW) were positively correlated with the gEBV of carcass weight (gCW). The DEP did not affect ADG. Neither the gMS nor the DEP affected the MS and beef quality grade. The intramuscular fat (IMF) content in the longissimus thoracis (LT) tended to be higher (P = 0.08) in the high-gMS groups than in the low-gMS groups. The mRNA levels of lipogenic acetyl-CoA carboxylase and fatty acid binding protein 4 genes in the LT were higher (P < 0.05) in the high-gMS group than in the low-gMS group. Overall, the IMF content tended to be affected by the gMS, and the genetic potential (i.e., gMS) was associated with the functional activity of lipogenic gene expression. The gCW was associated with the measured BW and CW. The results demonstrated that the gMS and the gCW may be used as early prediction indexes for meat quality and growth potential of beef cattle.

Prasugrel-based de-escalation vs. conventional therapy after percutaneous coronary intervention in ACS patients according to the renal function

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): A consortium of six companies in Korea (Daiichi Sankyo, Boston Scientific, Terumo, Biotronik, Qualitech Korea, and Dio).

Background

Patients with coronary artery disease and impaired renal function are at higher risk for both bleeding and ischemic adverse events after percutaneous coronary intervention (PCI).

Purpose

We assessed the efficacy and safety of a prasugrel based de-escalation strategy in patients with impaired renal function.

Methods

We conducted a post-hoc analysis of the HOST-REDUCE-POLYTECH-ACS study. Patients with available estimated glomerular filtration rate (eGFR) (n=2,311) were categorized into three groups. (high eGFR: ≥90 mL/min; intermediate eGFR: ≥60 and &lt;90 mL/min; low eGFR: &lt;60 mL/min). The endpoints were bleeding outcomes (Bleeding Academic Research Consortium type 2, or higher), ischemic outcomes (cardiovascular death, myocardial infarction, stent thrombosis, repeat revascularization, and ischemic stroke), and net adverse clinical events (all cause death, BARC 2 or greater bleeding, MI, stent thrombosis, repeat revascularization, and ischemic stroke) at 1 year follow-up. The hazard ratio (HR) and 95% Confidence interval (CI) were calculated from the multivariate Cox proportional hazard regression analysis. Covariates that were considered clinically meaningful were included. The probability risk ratio was obtained by dividing ischemic hazard function from the bleeding hazard function.

Results

With respect to net adverse clinical events, prasugrel de-escalation was beneficial regardless of baseline renal function (p for interaction = 0.508). The relative reduction in bleeding risk from prasugrel de-escalation was higher in the low eGFR group compared with that from both the intermediate and high eGFR groups (relative reduction: 64% [HR 0.36, 95% CI 0.15–0.83] vs. 50% [HR 0.50, 95% CI 0.28-0.90] and 52% [HR 0.48, 95% CI 0.21-1.13] for low, intermediate, and high eGFR groups, p for interaction=0.646). Ischemic risk from prasgurel de-escalation was not significant in all eGFR groups ([HR 1.18, 95% CI 0.47-2.98], [HR 0.95, 95% CI 0.53-1.69], and [HR 0.61, 95% CI 0.26-1.39)], respectively, p for interaction=0.119). The probability risk ratio was highest in low eGFR group (1.06 vs. 1.26 vs. 1.36, for high, intermediate, and low eGFR groups, respectively, p for trend&lt;0.001), suggesting higher relative bleeding risk above ischemic risk. Within those randomized to the de-escalation strategy, the mean probability risk ratio was not significantly different according to renal function (0.89, vs. 0.84 vs. 0.80 respectively, p for trend = 0.053), which was in contrast to those randomized to the conventional strategy where the mean probability risk ratio increased significantly as renal function decreased (1.24 vs. 1.67 vs. 1.94 respectively, p for trend&lt;0.001).

Conclusion

The beneficial effect of prasugrel-based de-escalation strategy was consistent regardless of the baseline renal function, which was mostly driven by a reduction in bleeding risk which was greatest in those with low eGFR.

Contrast-Enhanced CT and Ultrasonography Features of Intracholecystic Papillary Neoplasm with or without associated Invasive Carcinoma

OBJECTIVE

To assess the contrast-enhanced CT and ultrasonography (US) findings of intracholecystic papillary neoplasm (ICPN) and determine the imaging features predicting ICPN associated with invasive carcinoma (ICPN-IC).

MATERIALS AND METHODS

In this retrospective study, we enrolled 119 consecutive patients, including 60 male and 59 female, with a mean age ± standard deviation of 63.3 ± 12.1 years, who had pathologically confirmed ICPN (low-grade dysplasia [DP] = 34, high-grade DP = 35, IC = 50) and underwent preoperative CT or US. Two radiologists independently assessed the CT and US findings, focusing on wall and polypoid lesion characteristics. The likelihood of ICPN-IC was graded on a 5-point scale. Univariable and multivariable logistic regression analyses were performed to identify significant predictors of ICPN-IC separately for wall and polypoid lesion findings. The performances of CT and US in distinguishing ICPN-IC from ICPN with DP (ICPN-DP) was evaluated using the area under the receiver operating characteristic curve (AUC).

RESULTS

For wall characteristics, the maximum wall thickness (adjusted odds ratio [aOR] = 1.4; 95% confidence interval [CI]: 1.1-1.9) and mucosal discontinuity (aOR = 5.6; 95% CI: 1.3-23.4) on CT were independently associated with ICPN-IC. Among 119 ICPNs, 110 (92.4%) showed polypoid lesions. Regarding polypoid lesion findings, multiplicity (aOR = 4.0; 95% CI: 1.6-10.4), lesion base wall thickening (aOR = 6.0; 95% CI: 2.3-15.8) on CT, and polyp size (aOR = 1.1; 95% CI: 1.0-1.2) on US were independently associated with ICPN-IC. CT showed a higher diagnostic performance than US in predicting ICPN-IC (AUC = 0.793 vs. 0.676; p = 0.002).

CONCLUSION

ICPN showed polypoid lesions and/or wall thickening on CT or US. A thick wall, multiplicity, presence of wall thickening in the polypoid lesion base, and large polyp size are imaging findings independently associated with invasive cancer and may be useful for differentiating ICPN-IC from ICPN-DP.

Sonazoid™ versus SonoVue® for Diagnosing Hepatocellular Carcinoma Using Contrast-Enhanced Ultrasound in At-Risk Individuals: A Prospective, Single-Center, Intraindividual, Noninferiority Study

OBJECTIVE

To determine whether Sonazoid-enhanced ultrasound (SZUS) was noninferior to SonoVue-enhanced ultrasound (SVUS) in diagnosing hepatocellular carcinoma (HCC) using the same diagnostic criteria.

MATERIALS AND METHODS

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, and > 10 minutes.

RESULTS

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 the > 10-minutes criterion (59.0% vs. 59.0%, p = 0.989), and the specificities were not significantly different (90.9% vs. 86.4%, p = 0.072).

CONCLUSION

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.

The Acceptance Behavior of Smart Home Health Care Services in South Korea: An Integrated Model of UTAUT and TTF

With the COVID-19 pandemic, the importance of home health care to manage and monitor one's health status in a home environment became more crucial than ever. This change raised the need for smart home health care services (SHHSs) and their extension to everyday life. However, the factors influencing the acceptance behavior of SHHSs have been inadequately investigated and failed to address why users have the intention to use and adopt the services. This study aimed to analyze the influential factors and measure the behavioral acceptance of SHHSs in South Korea. This study adopted the integrated model of the unified theory of acceptance and use of technology (UTAUT) and task-technology fit (TTF) to understand the behavioral acceptance of SHHSs from users' perceptions and task-technology fit. Multiple-item scales were established based on validated previous measurement scales and adjusted in accordance with SHHS context. Data from 487 valid samples were analyzed statistically, applying partial least square structural equation modeling. The results indicated that the integrated acceptance model explained 55.2% of the variance in behavioral intention, 44.9% of adoption, and 62.5% of the continuous intention to use SHHSs, supporting 11 of the 13 proposed hypotheses. Behavioral intention was positively influenced by users' perceptions on performance expectancy, effort expectancy, social influence, and functional conditions. Task-technology fit significantly influenced performance expectancy and behavioral intention, validating the linkage between the two models. Meanwhile, task characteristics were insignificant to determine task-technology fit, which might stem from complex home health care needs due to the COVID-19 pandemic, but were not sufficiently resolved by current service technologies. The findings implied that the acceptance of SHHSs needs to be evaluated according to both the user perceptions of technologies and the matching fit of task and technology. Theoretically, this study supports the applicability of the integrated model of UTAUT and TTF to the domain of SHHS, and newly proposed the measurement items of TTF reflecting the domain specificity of SHHS, providing empirical evidence during the pandemic era in South Korea. Practically, the results could suggest to the planners and strategists of home health care services how to promote SHHS in one's health management.

Reduction of olecranon fractures with no or minimal dorsal cortex comminution based on the contour of the posterior ulnar cortex: does it restore the greater sigmoid notch?

INTRODUCTION

When treating olecranon fractures surgically, surgeons rely on the contour of the posterior cortex of the proximal ulna. However, it is unclear whether the greater sigmoid notch (GSN) is restored anatomically by this method. We analyzed whether reduction of fractures based on the posterior ulnar cortex contour is reliable for restoration of the GSN contour in displaced olecranon fractures with no or minimal dorsal cortex comminution.

MATERIALS AND METHODS

We performed a retrospective review of 23 patients with Mayo type 2 olecranon fractures with no or minimal dorsal cortex comminution who were treated surgically. We analyzed pre- and postoperative elbow CT images and measured the interfragmentary distance (IFD), articular step-off, articular gap, contour defect and GSN angle to evaluate the restoration of the GSN contour.

RESULTS

The mean preoperative IFD and contour defect were 16.5 mm (range 4.3-35.6 mm) and 4.3 mm (range 0.7-13.3 mm), respectively. Postoperatively, there was no residual IFD, and the mean contour defect decreased significantly to 1.4 mm (range 0-3.7 mm). The residual articular step-off and gap were 0.2 mm (range 0-3.8 mm) and 1.0 mm (range 0-5.9 mm), respectively. Acceptable GSN restoration was achieved in 14 of 23 patients (60.9%). Sixteen patients had > 2 mm of preoperative contour defect, and 7 (43.8%) achieved acceptable GSN restoration; the remaining 7 patients (100%) who had < 2 mm of the contour defect achieved acceptable GSN restoration. Patients whose preoperative contour defect was > 2 mm had a higher risk of unacceptable GSN restoration, with an odds ratio of 2.29 (p = 0.019).

CONCLUSIONS

In displaced olecranon fractures without significant dorsal cortex comminution, reduction based on the posterior ulnar cortex could be reliable for fractures with under 2 mm of preoperative contour defect, but not for those with > 2 mm of contour defect.

LEVEL OF EVIDENCE

IV.

Prediction of residual tumor and overall survival after first-line surgery in patients with pancreatic ductal adenocarcinoma using preoperative magnetic resonance imaging findings

BACKGROUND

Complete resection is the only potentially curative treatment in patients with pancreatic ductal adenocarcinoma (PDA) and is associated with a longer overall survival (OS) than incomplete resection of tumor. Hence, prediction of the resection status after surgery would help predict the prognosis of patients with PDA.

PURPOSE

To predict residual tumor (R) classification and OS in patients who underwent first-line surgery for PDA using preoperative magnetic resonance imaging (MRI).

MATERIAL AND METHODS

In this study, 210 patients with PDA who underwent MRI and first-line surgery were randomly categorized into a test group (n=150) and a validation group (n=60). The R classification was divided into R0 (no residual tumor) and R1/R2 (microscopic/macroscopic residual tumor). Preoperative MRI findings associated with R classification and OS were assessed by using logistic regression and Cox proportional hazard models. In addition, the prediction models for the R classification and OS were validated using calibration plots and C statistics.

RESULTS

On preoperative MRI, portal vein encasement (odds ratio 4.755) was an independent predictor for R1/R2 resection (P=0.040). Tumor size measured on MRI (hazard ratio [HR] per centimeter 1.539) was a predictor of OS, along with pathologic N1 and N2 stage (HR 1.944 and 3.243, respectively), R1/R2 resection (HR 3.273), and adjuvant chemoradiation therapy (HR 0.250) (P<0.050). Calibration plots demonstrated satisfactory predictive performance.

CONCLUSION

Preoperative MRI was valuable for predicting R1/R2 resection using portal vein encasement. Tumor size measured on MRI was useful for the prediction of OS after first-line surgery for PDA.

CT/MRI and CEUS LI-RADS Major Features Association with Hepatocellular Carcinoma: Individual Patient Data Meta-Analysis

Background The Liver Imaging Reporting and Data System (LI-RADS) assigns a risk category for hepatocellular carcinoma (HCC) to imaging observations. Establishing the contributions of major features can inform the diagnostic algorithm. Purpose To perform a systematic review and individual patient data meta-analysis to establish the probability of HCC for each LI-RADS major feature using CT/MRI and contrast-enhanced US (CEUS) LI-RADS in patients at high risk for HCC. Materials and Methods Multiple databases (MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scopus) were searched for studies from January 2014 to September 2019 that evaluated the accuracy of CT, MRI, and CEUS for HCC detection using LI-RADS (CT/MRI LI-RADS, versions 2014, 2017, and 2018; CEUS LI-RADS, versions 2016 and 2017). Data were centralized. Clustering was addressed at the study and patient levels using mixed models. Adjusted odds ratios (ORs) with 95% CIs were determined for each major feature using multivariable stepwise logistic regression. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) (PROSPERO protocol: CRD42020164486). Results A total of 32 studies were included, with 1170 CT observations, 3341 MRI observations, and 853 CEUS observations. At multivariable analysis of CT/MRI LI-RADS, all major features were associated with HCC, except threshold growth (OR, 1.6; 95% CI: 0.7, 3.6; P = .07). Nonperipheral washout (OR, 13.2; 95% CI: 9.0, 19.2; P = .01) and nonrim arterial phase hyperenhancement (APHE) (OR, 10.3; 95% CI: 6.7, 15.6; P = .01) had stronger associations with HCC than enhancing capsule (OR, 2.4; 95% CI: 1.7, 3.5; P = .03). On CEUS images, APHE (OR, 7.3; 95% CI: 4.6, 11.5; P = .01), late and mild washout (OR, 4.1; 95% CI: 2.6, 6.6; P = .01), and size of at least 20 mm (OR, 1.6; 95% CI: 1.04, 2.5; P = .04) were associated with HCC. Twenty-five studies (78%) had high risk of bias due to reporting ambiguity or study design flaws. Conclusion Most Liver Imaging Reporting and Data System major features had different independent associations with hepatocellular carcinoma; for CT/MRI, arterial phase hyperenhancement and washout had the strongest associations, whereas threshold growth had no association. © RSNA, 2021 Online supplemental material is available for this article.

Diagnostic criteria of perfluorobutane-enhanced ultrasonography for diagnosing hepatocellular carcinoma in high-risk individuals: how is late washout determined?

PURPOSE

The aim of this study was to investigate the optimal washout criteria of perfluorobutane-enhanced ultrasonography (PFB-US) for the diagnosis of hepatocellular carcinoma (HCC) in high-risk individuals.

METHODS

Participants at risk of HCC with treatment-naïve solid hepatic observations (≥1 cm) who underwent PFB-US from March 2019 to September 2020 were prospectively recruited. Arterial phase hyperenhancement (APHE), washout time, and washout degree were evaluated. The diagnosis of HCC was made by non-rim APHE with late and mild washout. The per-lesion diagnostic performance for diagnosing HCC using different cutoffs for late washout (50, 55, 60, 65, and 70 seconds postcontrast) and the different time windows for determining washout (until 2, 3, 4, 5, 6, 7, 8, 9, and 10 minutes postcontrast) were compared using the McNemar test.

RESULTS

In total, 101 participants with 113 observations (mean size, 33.5±2.8 mm; HCCs [n=82], non-HCC malignancies [n=16], benign [n=15]) were evaluated. Non-rim APHE was observed in 86.6% (71/82) of HCCs. As the cutoff time for late washout increased, the specificity increased to 100% (95% confidence interval [CI], 88.8% to 100%) at the 60-second cutoff with 62.2% sensitivity (95% CI, 50.8% to 72.7%). When the time window for determining washout became wider, the sensitivity and accuracy increased until 6 minutes, with 100% specificity at all times.

CONCLUSION

Determining washout within 6 minutes after contrast injection with a 60-second cutoff for late washout showed the highest sensitivity without losing specificity for diagnosing HCC using PFB-US in individuals at high risk.

Joint segmentation and classification of hepatic lesions in ultrasound images using deep learning

OBJECTIVES

To develop a convolutional neural network system to jointly segment and classify a hepatic lesion selected by user clicks in ultrasound images.

METHODS

In total, 4309 anonymized ultrasound images of 3873 patients with hepatic cyst (n = 1214), hemangioma (n = 1220), metastasis (n = 1001), or hepatocellular carcinoma (HCC) (n = 874) were collected and annotated. The images were divided into 3909 training and 400 test images. Our network is composed of one shared encoder and two inference branches used for segmentation and classification and takes the concatenation of an input image and two Euclidean distance maps of foreground and background clicks provided by a user as input. The performance of hepatic lesion segmentation was evaluated based on the Jaccard index (JI), and the performance of classification was based on accuracy, sensitivity, specificity, and the area under the receiver operating characteristic curve (AUROC).

RESULTS

We achieved performance improvements by jointly conducting segmentation and classification. In the segmentation only system, the mean JI was 68.5%. In the classification only system, the accuracy of classifying four types of hepatic lesions was 79.8%. The mean JI and classification accuracy were 68.5% and 82.2%, respectively, for the proposed joint system. The optimal sensitivity and specificity and the AUROC of classifying benign and malignant hepatic lesions of the joint system were 95.0%, 86.0%, and 0.970, respectively. The respective sensitivity, specificity, and the AUROC for classifying four hepatic lesions of the joint system were 86.7%, 89.7%, and 0.947.

CONCLUSIONS

The proposed joint system exhibited fair performance compared to segmentation only and classification only systems.

KEY POINTS

• The joint segmentation and classification system using deep learning accurately segmented and classified hepatic lesions selected by user clicks in US examination. • The joint segmentation and classification system for hepatic lesions in US images exhibited higher performance than segmentation only and classification only systems. • The joint segmentation and classification system could assist radiologists with minimal experience in US imaging by characterizing hepatic lesions.

A novel index reflecting both anatomical and physiologic parameters in coronary artery disease, the FFR adjusted SYNTAX score (FaSs)

Background

Various physiology-based indices have been proposed to predict adverse clinical events in patients with coronary artery disease (CAD), such as the sum of three vessel-fractional flow reserve (3v-FFR), and the functional SYNTAX score (fSS). However, these values could not fully reflect the anatomical factors, which remains as a barrier for clinical application of these indices.

Purpose

To propose a novel index which can reflect both anatomical and physiologic features in CAD patients, and evaluate the additional predictive value for cardiovascular adverse events compared to previous indices.

Methods

For an index which can reflect both anatomical and physiologic features, we proposed the FFR adjusted SYNTAX score (FaSs). The FaSs is calculated by adding the product of the SYNTAX score and `1-FFR', for all three major coronary arteries. Among the 1136 patients who enrolled at 3V FFR-FRIENDS study, we investigated 866 patients, after excluding those who had missing variables. The 3v-FFR, fSS and FaSs were calculated, derived from the baseline FFR and SYNTAX score. Patients were divided into two groups according to the median value of each index. The primary endpoint was major adverse cardiac events (MACE, a composite of cardiac death, myocardial infarction and ischemia-driven revascularization) at 2 years follow-up.

Results

Among the total population, MACE occurred in 35 (4.04%) patients. Using the median value in a multivariable COX regression model, only FaSs was associated with an increased risk of MACE, (Hazard Ratio [HR] 5.256, 95% confidence interval [CI] 2.014–13.720), while 3v-FFR (HR 1.383, 95% CI 0.685–2.790) and fSS (HR 1.640, 95% CI 0.830–3.243) were not significantly associated with a higher risk of MACE. This was also observed in the Kaplan Meier survival curve analysis (log-rank p value: p&lt;0.001 for FaSs, 0.153 for 3v-FFR, and 0.061 for fSS; Figure 1) The sensitivity and specificity of the FaSs was 85.7% and 51.6%, which was higher compared to the 3v-FFR (62.9% and 49.3%, respectively) and fSS (57.1% and 58.5%, respectively). When these indices were combined with clinical risk factors (age, sex, hypertension, diabetes, hyperlipidemia, chronic renal failure, LVEF&lt;40%), FaSs was superior compared with 3v-FFR and fSS assessed in regards of the predictive accuracy for MACE (Figure 2).

Conclusion

The FaSs, which is a novel index calculated by a formula using the SYNTAX score and FFR, showed a superior predictive value for MACE compared to previous indices. Our results confirm the importance of considering both anatomical and physiologic parameters in evaluating the patient's risk for cardiovascular adverse outcomes.

Funding Acknowledgement

Type of funding sources: None.

Prediction of prognosis and resectability using MR imaging, clinical, and histopathological findings in patients with perihilar cholangiocarcinoma

PURPOSE

To predict poor overall survival (OS) and risk of residual tumor after surgery using MR imaging, clinical, and histopathological findings in perihilar cholangiocarcinoma.

METHODS

196 patients with perihilar cholangiocarcinoma who underwent preoperative MRI and curative-intent surgery were retrospectively included. MRI findings were assessed by two radiologists. Clinical characteristics and histopathological results such as serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), T and N stage, and resection status, were also investigated. Cox regression analysis and the Kaplan-Meier method were used to identify prognostic factors for OS. We further analyzed the correlation between MRI features and residual tumors using logistic regression analysis.

RESULTS

The median OS was 25.0 ± 26.6 months. T stage (hazard ratio [HR] 6.26, p = 0.014), N stage (HR 1.86, p = 0.002), CA-19-9 >37 U/mL (HR 2.06, p < 0.001), enlarged LN on MRI (HR 1.69, p = 0.006), and residual tumor (HR 1.52, p = 0.034) were important predictors of poor survival. The 5-year OS of the complete resection group (n = 107) was significantly better than that of the residual tumor group (n = 89) (35.5% vs. 18.8%, p = 0.002). Additionally, peritumoral fat stranding (odds ratio[OR] 2.09, p = 0.027), Bismuth type III/IV (OR 1.95, p = 0.022), and common bile duct (CBD) involvement (OR 2.3, p = 0.008) on MRI were important predictors of residual tumors in univariate analyses. However, absence of peritumoral fat stranding was a significant independent predictor for complete resection (OR 1.99, p = 0.048) and showed the highest sensitivity, at 79.8%.

CONCLUSION

MR imaging, clinical and histopathological results are useful for predicting poor survival after surgery for perihilar cholangiocarcinoma. Furthermore, MRI findings, including peritumoral fat stranding, CBD involvement, and Bismuth type, are important for the prediction of residual tumors.

Gadoxetate-enhanced MRI Features of Proliferative Hepatocellular Carcinoma Are Prognostic after Surgery

Background Hepatocellular carcinomas (HCCs) are heterogeneous neoplasms, and the prognosis varies based on the subtype. Two broad molecular classes of HCC have been proposed: a proliferative and a nonproliferative class. Purpose To evaluate the gadoxetate-enhanced MRI findings of the proliferative class HCC and its prognostic significance after surgery. Materials and Methods This retrospective cohort study evaluated patients with surgically resected treatment-naive single HCC (≤5 cm) who underwent hepatic resection from January 2010 through February 2013 and preoperative gadoxetate-enhanced MRI. A Cox proportional hazards model was used to determine the predictive factors for overall survival (OS), intrahepatic distant recurrence, and extrahepatic metastasis (EM). The mean follow-up period was 75.5 months ± 30.2 (standard deviation). Multivariable logistic regression was performed to determine factors associated with proliferative class HCC. Results A total of 158 patients (mean age, 57 years ± 11; 128 men and 30 women) were evaluated. Forty-two of the 158 HCCs (26.6%) were proliferative class HCCs (17 macrotrabecular-massive HCCs, 14 keratin 19-positive HCCs, 10 scirrhous HCCs, and one sarcomatoid HCC). The proliferative class was associated with worse OS (hazard ratio [HR], 3.1; 95% CI: 1.5, 6.0; P = .01) and higher rates of intrahepatic distant recurrence (HR, 1.83; 95% CI: 1.1, 2.9; P = .01) and EM (HR, 9.97; 95% CI: 3.2, 31.4; P < .001). Rim arterial phase hyperenhancement (APHE) at gadoxetate-enhanced MRI (odds ratio [OR], 6.35; 95% CI: 1.9, 21.7; P = .01) and high serum α-fetoprotein (>100 ng/mL) (OR, 4.18; 95% CI: 1.64, 10.7; P = .01) were independent predictors for proliferative HCC. The presence of rim APHE was associated with poor OS (HR, 2.4; 95% CI: 1.2, 4.9; P = .02) and higher rates of EM (HR, 7.4; 95% CI: 2.5, 21.7; P < .01). Conclusion The proliferative class of hepatocellular carcinoma (HCC) is an independent factor for poor overall survival with increased rates of intrahepatic and extrahepatic metastasis. Rim arterial phase hyperenhancement at gadoxetate-enhanced MRI may help to identify proliferative class HCC and predict poor overall survival and an increased incidence of extrahepatic metastasis. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Krinsky and Shanbhogue in this issue.

Radio-pathologic correlation of biphenotypic primary liver cancer (combined hepatocellular cholangiocarcinoma): changes in the 2019 WHO classification and impact on LI-RADS classification at liver MRI

OBJECTIVES

To explain the new changes in pathologic diagnoses of biphenotypic primary liver cancer (PLC) according to the updated 2019 World Health Organization (WHO) classification and how it impacts Liver Imaging Reporting and Data System (LI-RADS) classification using gadoxetic acid-enhanced MRI (Gd-EOB-MRI).

METHODS

We retrospectively included 209 patients with pathologically proven biphenotypic PLCs according to the 2010 WHO classification who had undergone preoperative Gd-EOB-MRI between January 2009 and December 2018. Imaging analysis including LI-RADS classification and pathologic review including the proportion of tumor components were performed. Frequencies of each diagnosis and subtype according to the 2010 and 2019 WHO classifications were compared, and changes in LI-RADS classification were evaluated. Univariable and multivariable analysis were performed to determine significant tumor component for LI-RADS classification.

RESULTS

Of the 209 biphenotypic PLCs of the 2010 WHO classification, 177 (84.7%) were diagnosed as bipheonotypic PLCs, 25 (12.0%) as hepatocellular carcinomas (HCCs), and 7 (3.3%) as cholangiocarcinomas (CCAs) using the 2019 WHO classification. Of the 177 biphenotypic PLCs, LR-M, LR-4, and LR-5 were assigned in 77 (43.5%), 21 (11.9%), and 63 (35.5%), respectively. There were no significant differences in the proportion of LR-5 and LR-M categories between the WHO 2010 and 2019 classifications (p = 0.941). Proportion of HCC component was the only independent factor for LI-RADS classification (adjusted odds ratio, 1.02; p < 0.001).

CONCLUSION

According to the 2019 WHO classification, 15% of biphenotypic PLCs from the 2010 WHO classification were re-diagnosed as HCCs or CCAs, and a substantial proportion of biphenotypic PLCs of the 2019 WHO classification could be categorized as LR-4 or LR-5 on Gd-EOB-MRI.

KEY POINTS

• Among 209 diagnosed biphenotypic PLCs according to the 2010 WHO classification, 177 (84.7%) lesions were reclassified as bipheonotypic PLCs, 25 (12.0%) as HCCs, and 7 (3.3%) as CCAs using the 2019 WHO classification. • Of the 177 biphenotypic PLCs at the 2019 WHO classification, LR-M, LR-4, and LR-5 were assigned in 77 (43.5%), 21 (11.9%), and 63 (35.5%), respectively. • LI-RADS classification relied on the proportion of HCC component (adjusted odds ratio,1.02; p < 0.001).

Comparisons between image quality and diagnostic performance of 2D- and breath-hold 3D magnetic resonance cholangiopancreatography at 3T

OBJECTIVES

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.

METHODS

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.

RESULTS

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, p < 0.001 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 (p > 0.05).

CONCLUSION

Breath-hold 3D MRCP with GRASE or CS can provide better image quality than 2D MRCP in a comparable scan time.

KEY POINTS

• 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.

Virtual noncontrast images derived from dual-energy CT for assessment of hepatic steatosis in living liver donors

PURPOSE

This study aimed to investigate the correlation of attenuation between virtual noncontrast (VNC) and true noncontrast (TNC) CT images and compare the diagnostic performance for hepatic steatosis using MR spectroscopy (MRS) as the reference standard.

METHODS

A total of 131 consecutive hepatic donor candidates who underwent dual-source dual-energy CT and MRS within one month from January 2018 to April 2019 were included. An MRS value > 5.8 % was regarded as substantial hepatic steatosis. The correlation of attenuation between TNC and VNC in the liver and spleen, and liver attenuation index (LAI), defined as hepatic minus splenic attenuation, was evaluated using Spearman's rank correlation. The diagnostic performance of the LAI for hepatic steatosis was compared using receiver operating characteristic analyses.

RESULTS

Twenty-three candidates (17.6 %) had substantial hepatic steatosis. The median liver attenuation (66.7 [IQR, 63.5-70.9] vs. 63.5 [IQR, 60.3-66.9], p < .001) and LAI (12.9 [9.3-16.7] vs. 7.4 [3.9-11.9], p < .001) in the VNC were higher than those in the TNC. Hepatic attenuation (r = 0.93, p < .001), splenic attenuation (r = 0.55, p < .001), and LAI (r = 0.87, p < .001) were significantly correlated between TNC and VNC. Area under the curve of LAI in TNC and VNC were 0.88 (cutoff, LAI < 3.1) and 0.84 (cutoff, LAI < 10.1), respectively, indicating no statistically significant difference (p = 0.11).

CONCLUSION

The LAI of VNC is significantly correlated with that of TNC and might be feasible for diagnosing substantial hepatic steatosis in living liver donor candidates using different cutoff values of LAI.

Evaluation of LI-RADS Version 2018 Treatment Response Algorithm for Hepatocellular Carcinoma in Liver Transplant Candidates: Intraindividual Comparison between CT and Hepatobiliary Agent-enhanced MRI

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 (<100%) necrotic obtained from the explanted liver served as the reference standard. Sensitivity and specificity of the LI-RADS TRA in the consensus reading were then compared between CT and HBA-enhanced MRI by using the ratio estimator approach. Interobserver agreements were calculated by using Fleiss κ statistics. Results There were 165 patients (mean age, 62 years ± 9 [standard deviation]; 135 men) with a total of 237 lesions, of which 107 were viable tumors (45.1%) at pathologic evaluation. With the LI-RADS TRA, sensitivity and specificity of the viable category for detection of viable HCCs at pathologic evaluation were 42.1% (45 of 107 lesions) and 95.4% (124 of 130 lesions) with CT and 52.3% (56 of 107 lesions) and 93.9% (122 of 130 lesions) with HBA-enhanced MRI, with a significant difference in sensitivity but not specificity (P = .009 and P = .42, respectively). Interobserver agreements for the LI-RADS TRA were substantial for both CT and HBA-enhanced MRI (κ, 0.69 for both). Conclusion In patients who underwent local-regional therapy for hepatocellular carcinoma before liver transplant, hepatobiliary agent-enhanced MRI was more sensitive than CT in evaluating tumor viability with the Liver Imaging Reporting and Data System, version 2018, treatment response algorithm. ©RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Bashir and Mendiratta-Lala in this issue.

Switching Monopolar No-Touch Radiofrequency Ablation Using Octopus Electrodes for Small Hepatocellular Carcinoma: A Randomized Clinical Trial

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.

Determining the Intellectual Structure and Academic Trends of Smart Home Health Care Research: Coword and Topic Analyses

Background

With the rapid development of information and communication technologies, smart homes are being investigated as effective solutions for home health care. The increasing academic attention on smart home health care has primarily been on the development and application of smart home technologies. However, comprehensive studies examining the general landscape of diverse research areas for smart home health care are still lacking.

Objective

This study aims to determine the intellectual structure of smart home health care in a time series by conducting a coword analysis and topic analysis. Specifically, it investigates (1) the intellectual basis of smart home health care through overall academic status, (2) the intellectual foci through influential keywords and their evolutions, and (3) intellectual trends through primary topics and their evolutions.

Methods

Analyses were conducted in 5 steps: (1) data retrieval from article databases (Web of Science, Scopus, and PubMed) and the initial dataset preparation of 6080 abstracts from the year 2000 to the first half of 2019; (2) data preprocessing and refinement extraction of 25,563 words; (3) a descriptive analysis of the overall academic status and period division (ie, 4 stages of 3-year blocks); (4) coword analysis based on word co-occurrence networks for the intellectual foci; and (5) topic analysis for the intellectual trends based on latent Dirichlet allocation (LDA) topic modeling, word-topic networks, and researcher workshops.

Results

First, regarding the intellectual basis of smart home health care, recent academic interest and predominant journals and research domains were verified. Second, to determine the intellectual foci, primary keywords were identified and classified according to the degree of their centrality values. Third, 5 themes pertaining to the topic evolution emerged: (1) the diversification of smart home health care research topics; (2) the shift from technology-oriented research to technological convergence research; (3) the expansion of application areas and system functionality of smart home health care; (4) the increased focus on system usability, such as service design and experiences; and (5) the recent adaptation of the latest technologies in health care. Based on these findings, the pattern of technology diffusion in smart home health care research was determined as the adaptation of technologies, the proliferation of application areas, and an extension into system design and service experiences.

Conclusions

The research findings provide academic and practical value in 3 aspects. First, they promote a comprehensive understanding of the smart home health care domain by identifying its multifaceted intellectual structure in a time series. Second, they can help clinicians discern the development and dispersion level of their respective disciplines. Third, the pattern of technology diffusion in smart home health care could help scholars comprehend current and future research trends and identify research opportunities based on upcoming research waves of newly adapted technologies in smart home health care.

Synergistic Effects of Pulsed Focused Ultrasound and a Doxorubicin-Loaded Microparticle-Microbubble Complex in a Pancreatic Cancer Xenograft Mouse Model

The synergistic effects of a doxorubicin (Dox)-loaded microparticle-microbubble complex (DMMC) and focused ultrasound (FUS) with a short duty cycle (5%) were evaluated in a pancreatic cancer xenograft model established by inoculating immunodeficient mice with CFPAC-1 cells. The efficacy of the DMMC with FUS (study 1), the effect of conjugating the particles as opposed to mixing them (study 2) and the levels of tumor apoptosis and intracellular Dox (study 3) were evaluated. The DMMC with FUS exhibited the lowest tumor growth rate (30.8 mm³/wk) and the highest intracellular Dox uptake (8.8%) and tumor cell apoptosis rate (58.7%) among all treatments. DMMC had a significantly lower growth rate than the mixture of Dox-loaded microparticles and microbubbles (44.2 mm³/wk, p < 0.01) when they were combined with FUS. In conclusion, DMMC with short-duty-cycle FUS holds promise for tumor growth suppression, which may be attributed to high intracellular Dox uptake.

Intra-individual comparison of dual portal venous phases for non-invasive diagnosis of hepatocellular carcinoma at gadoxetic acid-enhanced liver MRI

OBJECTIVES

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

KEY POINTS

• 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%).

Quantitative evaluation of posterior talar subluxation in posterior malleolar fractures: A preliminary study

BACKGROUNDS

Although ankle posterior subluxation is one of the major mechanisms by which posterior malleolar fractures (PMF) contribute to a worse prognosis, there is no parameter to address it quantitatively. So, we suggest a method that can evaluate posterior talar subluxation quantitatively in PMF.

METHODS

We retrospectively analyzed 37 patients with posterior malleolar fractures. The patients were divided into two groups: PMF without posterior talar subluxation (n = 18) and with posterior talar subluxation (n = 19). We measured the distance between the arc center of the talus and the anterior tibia (TAD), the percentage of articular involvement of the fracture fragment, the inter-fragment distance (IFD) and articular step-off. We analyzed significant differences and the correlations between the two groups for each index. The estimated area of the receiver operating characteristic (ROC) curve was calculated, and cutoff values were suggested to discriminate posterior talar subluxation.

RESULTS

TAD, IFD, and articular step-off were significantly greater in patients with posterior talar subluxation. (TAD: 14.3 vs. 2.8 mm, p < 0.001, IFD: 7.8 vs. 4.0 mm, p < 0.001, articular step-off: 3.6 vs. 2.0 mm, p = 0.004). The ROC curve showed that TAD was most useful to determine cutoff values for posterior talar subluxation. The area under the curve for TAD was 1.000, and the appropriate cutoff value was 5 mm. When a TAD of > 5 mm was used as a threshold, a sensitivity of 100% and a specificity of 100% were achieved in determining the presence of posterior talar subluxation. Also, higher TAD was correlated with IFD and articular step-off.

CONCLUSIONS

TAD can be a useful parameter for evaluating the posterior talar subluxation in PMF. It can reflect not only the degree of fracture displacement but also posterior talar subluxation quantitatively.

Ultrasound-guided transient elastography and two-dimensional shear wave elastography for assessment of liver fibrosis: emphasis on technical success and reliable measurements

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<0.001 for both). In participants for whom conventional TE failed, 2D-SWE provided high rates of technical success (36 of 36, 100%) and reliable measurements (30 of 36, 83.3%). TE failure was associated with female sex (odds ratio [OR], 5.85; 95% confidence interval [CI], 1.30 to 26.40), severe reverberation artifacts (OR, 8.79; 95% CI, 3.93 to 19.69), and high skin-to-liver capsule depth (OR, 1.23; 95% CI, 1.09 to 1.39).

Conclusion

US guidance in TE improved the technical success and reliable measurement rates in the assessment of LS in patients with CLD. In participants for whom TE failed, subsequent 2D-SWE successfully delivered reliable LS measurements.

Reproducibility of ultrasound attenuation imaging for the noninvasive evaluation of hepatic steatosis

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<0.001, respectively).

CONCLUSION

ATI showed high intra- and inter-observer reproducibility in the assessment of hepatic steatosis.

Additional value of contrast-enhanced ultrasound (CEUS) on arterial phase non-hyperenhancement observations (≥ 2 cm) of CT/MRI for high-risk patients: focusing on the CT/MRI LI-RADS categories LR-3 and LR-4

PURPOSE

To determine the added value of CEUS on arterial phase non-hyperenhancement (APNHE) observations (LR-3 and LR-4) of CT/MRI in high-risk patients.

METHODS

Forty-three patients with APNHE observations (≥ 2 cm) from CT/MRI were prospectively enrolled in this IRB-approved study and underwent CEUS. All observations were assessed by LI-RADS for CT/MRI and CEUS. The hemodynamic findings were compared. The mean follow-up period was 11.8 ± 2.1 months. Reference standard was made on 34-APNHE observations based on biopsy (n = 2), surgery (n = 2), and follow-up image (n = 30).

RESULTS

The median of observation size was 2.3 cm (IQR 2.0-2.5 cm). Among the 43-APNHE observations, 12-observations (27.9%) were further presented as arterial phase hyperenhancement (APHE) in CEUS with early (n = 1, CEUS LR-M), late (n = 10, CEUS LR-5), or no (n = 1, CEUS LR-4) washout. Compared to CT, CEUS presented concordant enhancement patterns in 16 (44.4%) in AP and 20 (55.6%) in PVP, respectively. Similarly, 13 (59.1%) and 14 (63.6%) observations showed concordant enhancement patterns between CEUS and MRI in AP and PVP, respectively. Of the 34-APNHE observations with final diagnosis (hepatocellular carcinoma [HCC] n = 12; intrahepatic cholangiocarcinoma [IHCC], n = 1; non-malignancy, n = 21), 4 HCCs (33.3%) and 1 IHCC (100%) were additionally diagnosed by CEUS, while 1 non-malignant lesion (4.5%) was misdiagnosed as HCC by CEUS.

CONCLUSION

Adding CEUS to APNHE observations from CT/MRI would be useful not only for definitely diagnosing HCC (CEUS LR-5) but also for other malignancies (CEUS LR-M). The discordance of dynamic features between the LI-RADS for CEUS and CT/MRI may reflect the different properties of contrast media, although the systems are not interchangeable.

Initial M Staging of Rectal Cancer: FDG PET/MRI with a Hepatocyte-specific Contrast Agent versus Contrast-enhanced CT

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 < .05 indicated a significance difference.ResultsSeventy-one participants (28 women; mean age ± standard deviation, 61 years ± 9; age range, 39-79 years) were enrolled. The M stage could not be determined with the standard-of-care protocol in 22 of the 71 participants (31%; 95% confidence interval [CI]: 20.5%, 43.1%) because of indeterminate lesions. However, among these participants, PET/MRI correctly helped identify all 14 (100%; 95% CI: 76.8%, 100%) without metastases and seven of eight (88%; 95% CI: 47.4%, 99.7%) who were later confirmed to have metastases. PET/MRI showed high specificity for ruling out metastatic disease compared with the standard-of-care protocol (98% [54 of 55 participants] vs 72% [40 of 55 participants], respectively; P < .001), without increasing the number of participants with missed metastasis (6% [one of 16 participants] vs 6% [one of 16 participants]; 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.

Prospective Validation of Repeatability of Shear Wave Dispersion Imaging for Evaluation of Non-alcoholic Fatty Liver Disease

This study was aimed at evaluating the intra-observer repeatability of shear wave dispersion imaging (SWDI) for evaluation of non-alcoholic fatty liver disease and assessing inter-observer repeatability in asymptomatic volunteers, using a commercial ultrasound system. This prospective study was approved by our institutional review board and informed consent was obtained from all patients. In group I composed of patients with suspected or alleged non-alcoholic fatty liver disease (n = 71), two sessions of SWDI were performed by one radiologist for evaluation of intra-observer repeatability. In group II composed of asymptomatic volunteers (n = 19), three independent sessions were performed by three radiologists. Intra-observer and inter-observer repeatability was assessed using intra-class correlation coefficients (ICCs). For intra-observer repeatability, the ICC was 0.955 (95% confidence interval: 0.926-0.973), and subgroup analysis revealed that body mass index, ultrasound steatosis grade and liver function test abnormalities did not affect ICCs. The ICC for inter-observer repeatability was 0.800 (95% confidence interval: 0.572-0.916). Thus, SWDI had excellent intra-and inter-observer repeatability.

Value of virtual monochromatic spectral image of dual-layer spectral detector CT with noise reduction algorithm for image quality improvement in obese simulated body phantom

BACKGROUND

Dual-layer spectral detector CT (SDCT) may provide several theoretical advantages over pre-existing DECT approaches in terms of adjustment-free sampling number and dose modulation, beam hardening correction, and production spectral images by post-processing. In addition, by adopting noise reduction algorithm, high contrast resolution was expected even in low keV level. We surmised that this improvement would be beneficial to obese people. Therefore, our aim of study is to compare image quality of virtual monochromatic spectral images (VMI) and polychromatic images reconstructed from SDCT with different body size and radiation dose using anthropomorphic liver phantom.

METHODS

One small and one large size of body phantoms, each containing eight (four high- and four low-contrast) simulated focal liver lesions (FLLs) were scanned by SDCT (at 120 kVp) using different Dose Right Indexes (DRIs). VMI were reconstructed from spectral base images from 40 keV to 200 keV. Hybrid iterative reconstruction (iDose4) was used for polychromatic image reconstruction. Image noise and contrast to noise ratio (CNR) were compared. Five radiologists independently rated lesion conspicuity, diagnostic acceptability and subjective noise level in every image sets, and determined optimal keV level in VMI.

RESULTS

Compare with conventional polychromatic images, VMI showed superior CNR at low keV level regardless of phantom size at every examined DRIs (Ps < 0.05). As body size increased, VMI had more gradual CNR decrease and noise increase than conventional polychromatic images. For low contrast FLLs in large phantom, lesion conspicuities at low radiation dose levels (DRI 16 and 19) were significantly increased in VMI (Ps < 0.05). Subjective image noise and diagnostic acceptabilities were significantly improved at VMI in both phantom size.

CONCLUSIONS

VMI of dual-layer spectral detector CT with noise reduction algorithm provides improved CNR, noise reduction, and better subjective image quality in imaging of obese simulated liver phantom compared with polychromatic images. This may hold promise for improving detection of liver lesions and improved imaging of obese patients.

Addition of Reliability Measurement Index to Point Shear Wave Elastography: Prospective Validation via Diagnostic Performance and Reproducibility

The clinical value of the reliability measurement index (RMI), newly added to point shear wave elastography (pSWE), was investigated. Forty-nine patients underwent both pSWE providing RMI (range: 0.0-1.0) and transient elastography (TE) before hepatic surgery. Interclass correlation coefficients (ICCs) between the median of the first two to nine measurements (as categorized by RMI values ≥0.0 (liver stiffness-reliability measurement index [LS-RMI] 0.0), ≥0.4 (LS-RMI 0.4) and ≥0.7 (LS-RMI 0.7) and the median of 10 consecutive measurements (LS-REF) were obtained. Compared with LS-REF, minimums of 7 LS-RMI 0.0, 5 LS-RMI 0.4 and 3 LS-RMI 0.7 measurements were required to obtain an ICC ≥0.95 with high inter-observer agreement (ICC ≥0.90). Diagnostic performance did not differ (p values >0.05) using these reduced numbers of LS measurements. Significant correlations were found between the reduced number of LS measurements and TE or METAVIR (p values <0.001). Therefore, RMI helped to improve reliability and reduce the number of LS measurements while maintaining the diagnostic performance of pSWE.

Usefulness of contrast-enhanced ultrasound using perfluorobutanecontaining microbubbles as a planning for percutaneous biopsies of focal hepatic lesions: a prospective feasibility study

AIMS

To determine whether contrast-enhanced US using perfluorobutane-containing microbubbles (SEUS) would be helpful for planning a hepatic biopsy.

MATERIAL AND METHODS

This prospective study included 40 patients who planned to undergo hepatic biopsy for focal hepatic lesions. All patients underwent B-mode US followed by SEUS. The radiologist evaluated the number of detected lesions, presence of necrosis, conspicuity of target lesion and technical feasibility using 4-point scale. Technical failure and occurrence of change of the target were also assessed. Computer tomography (CT) or magnetic resonance (MR) images were the reference techniques.

RESULTS

The mean number of lesions detected on CT and MR images was 6.5±8.4. In 20 (50%) of 40 patients, more focal lesions were detected on SEUS. Targeted lesion was changed in sixpatients (15%) on SEUS. Mean number of detected lesions on SEUS was significantly higher comparing with B-US (5.1±6.2 vs. 2.8±3.8, p<0.001). Conspicuity of the targeted lesion was improved in 67.5% (27 of 40) on SEUS and significantly more visualized than B-US (3.6±0.8 vs. 2.8±0.9, p<0.001). In 7 more patients the necrosis within the lesion was visualized (17.5%) using SEUS. The technical feasibility on SEUS was significantly higher than B-US (2.3±1.0 vs. 3.3±0.9, p<0.001). Technical failure was observed in only one patient (2.5%).

CONCLUSIONS

SEUS is a helpful technique for planning the hepatic biopsyin terms of detection, improving lesion conspicuity, tumor viable portion assessment and consequently higher operator confidence, compared with B-US.

Quantitative contrast-enhanced US helps differentiating neoplastic vs non-neoplastic gallbladder polyps

OBJECTIVES

To differentiate between large (≥ 1 cm in diameter) gallbladder (GB) non-neoplastic and neoplastic polyps using quantitative analysis of contrast-enhanced ultrasound (CEUS) findings.

METHODS

From September 2017 to May 2018, 29 patients (10 males; median age, 63 years) with GB polyps of ≥ 1 cm in diameter who were undergoing cholecystectomy were consecutively enrolled. All patients underwent preoperative conventional US and CEUS examinations. Quantitative analysis of CEUS findings using time-intensity curves between the two groups was independently performed by two radiologists. The interobserver agreement for the quantitative analysis of the CEUS results was measured using the intraclass correlation coefficient. Receiver operating characteristic analysis was performed to evaluate the diagnostic performance of CEUS examination.

RESULTS

After the cholecystectomy, the patients were classified into the non-neoplastic polyp group (n = 12) and the neoplastic polyp group (n = 17) according to the pathological results. The interobserver agreement for quantitative assessment between the two radiologists was near perfect to substantial. Quantitative assessment of the CEUS findings revealed that the rise time, mean transit time, time to peak, and fall time of non-neoplastic GB polyps were significantly shorter than those of neoplastic polyps (p < 0.001, p = 0.008, p = 0.013, and p = 0.002, respectively). The sensitivity and specificity of the quantitative CEUS parameters for the differentiation between the two groups were 76.5-100% and 75%, respectively, with an area under the curve of 0.765-0.887.

CONCLUSIONS

Quantitative analysis of CEUS findings could be valuable in differentiating GB neoplastic polyps from non-neoplastic polyps.

KEY POINTS

• Quantitative analysis of CEUS findings could be valuable in differentiating gallbladder neoplastic polyps from non-neoplastic polyps. • Quantitative analysis of CEUS findings in gallbladder polyps provides cut-off values for differentiation between neoplastic polyps and non-neoplastic polyps with near-perfect to substantial interobserver agreement.

Comparison of four different Shear Wave Elastography platforms according to abdominal wall thickness in liver fibrosis evaluation: a phantom study

AIMS

To compare the applicability, reliability and stiffness values of four different shear wave elastography (SWE) platforms and to determine the influence of abdominal wall thickness on those of four SWE platforms evaluating liver fibrosis. Material and methods: We used four different SWE platforms: transient elastography (TE), pSWE (S-shear wave), 2D SWE/ SSI (SuperSonic Imagine) and 2D SWE/GE (GE Health care). To identify the effect of abdominal wall thickness, five commercially available liver fibrosis phantoms were covered in 1.3 cm and 2.3 cm thick porcine abdominal walls, respectively. All measurements were performed by three observers. Absolute repeatability of each measurement was evaluated using coefficients of variation (CVs). Applicability rate, CVs and mean stiffness values were compared according to platforms and abdominal wall thickness.

RESULTS

Applicability rates were significantly different among the four SWE platforms (p<0.001): 2DSWE/SSI showed the lowest applicability rate (68.9%) compared with the other three platforms (TE, 95.6%, pSWE, 93.3%, 2D SWE/GE, 97.8%) due to higher technical failure rates in phantoms with thick wall. Repeatability was significantly different according to the platform and abdominal wall thickness. Stiffness values did not significantly differ according to abdominal wall thickness, even though the values were significantly different among four platforms in all phantoms.

CONCLUSIONS

The applicability, repeatability, and stiffness value were different depending on SWE platforms. Further, the applicability and repeatability would be more affected by abdominal wall thickness. Thus, careful consideration should be given to an appropriate SWE platform, when evaluating liver fibrosis in patients with thick abdominal wall.

An Ecological Approach to Smart Homes for Health Care Services: Conceptual Framework of a Smart Servicescape Wheel

Background

Smart homes are considered effective solutions for home health care for the elderly, as smart home technologies can reduce care costs and improve elderly residents’ independence. To develop a greater understanding of smart homes for health care services (SHHSs), this study accentuated the necessity of ecological approaches with an emphasis on environmental constraints. This study was based on 2 rationales: (1) users are inclined to perceive the service quality and service experience from environments (ie, servicescape) owing to the intangibility of health care and the pervasiveness of smart home technologies, and (2) both service domains are complex adaptive systems in which diversified and undefined service experiences—not only a few intended service flows—can be generated by complex combinations of servicescape elements.

Objective

This study proposed the conceptual framework of a Smart Servicescape Wheel (SSW) as an ecological approach delineating the extensive spectrum of environmental constraints in SHHSs.

Methods

The SSW framework was established based on a literature review.

Results

Generally divided by perceptible and imperceptible servicescapes, the SSW consists of the perceptible Physical scape (ie, hardware components, environmental cues, and human states) and Social scape (ie, service relationships and social relationships) as well as the imperceptible Datascape (ie, computing intelligence, databases, and communication networks). Following the ecological approach, each category of the SSW is subdivided and defined at the level of components or functions.

Conclusions

The SSW’s strengths lie in the various application opportunities for SHHSs. In terms of service planning and development, the SSW can be utilized to (1) establish the requirements for SHHS development, (2) associate with work domain analysis by defining component layers, and (3) understand the real contexts of SHHSs for the enhanced prediction of diverse service experiences. Regarding service management, it can be applied to develop measurement items for the operation and evaluation of SHHSs.

Quantitative Assessment of Liver Function by Using Gadoxetic Acid-enhanced MRI: Hepatocyte Uptake Ratio

Purpose To determine whether hepatocyte uptake ratios derived at gadoxetic acid-enhanced MRI correlate with quantitative measures of liver function and can help to identify contraindication to major hepatectomy. Materials and Methods Between August 2016 and October 2016, 50 study participants with chronic liver disease or cirrhosis underwent liver MRI at 3.0 T including T1 mapping and elastography. Liver function was quantitatively assessed by using the indocyanine green retention test (ICG R₁₅). T1 maps were obtained by using the Look-Locker sequence before and 10 minutes after gadoxetic acid administration (0.025 mmol/kg). The relationship between ICG R₁₅ and the following MRI parameters was evaluated: pre- and postcontrast T1 values of the liver, hepatocyte uptake ratio representing the amount of contrast media solely taken into hepatocytes, liver volume, and degree of enhancement at the common bile duct. Diagnostic performance of the hepatocyte uptake ratio to identify patients with ICG R₁₅ greater than 20% (ie, contraindication to hepatectomy) was compared with other parameters by using areas under the receiver operating characteristic curve. Results Hepatocyte uptake ratio showed a negative correlation with ICG R₁₅ r of -0.78 (P < .001). In participants with chronic liver disease or Child-Pugh class A, those with ICG R₁₅ of 20% or less showed higher hepatocyte uptake ratio than those with ICG R₁₅ greater than 20% (P < .001). Hepatocyte uptake ratios demonstrated better performance for helping to detect ICG R₁₅ greater than 20% than did liver volume (area under the curve, 0.96 vs 0.70; P = .01). Conclusion Hepatocyte uptake ratios are negatively correlated with liver function as measured by indocyanine green retention test and provide acceptable diagnostic performance for helping to identify participants who have contraindications to major hepatectomy. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Reeder in this issue.