Clinical impact of ampulla of Vater cancer subtype classification based on immunohistochemical staining.

BACKGROUND: The histological subtype is an important prognostic factor for ampulla of Vater (AoV) cancer. This study proposes a classification system for the histological subtyping of AoV cancer based on immunohistochemical (IHC) staining and its prognostic significance. METHODS: Seventy-five AoV cancers were analyzed for cytokeratin 7 (CK7), CK20, and causal-type homeobox transcription factor 2 (CDX2) expression by IHC staining. We differentiated the subtypes (INT, intestinal; PB, pancreatobiliary; MIX, mixed; NOS, not otherwise specified) into classification I: CK7/CK20, classification II: CK7/CK20 or CDX2, classification III: CK7/CDX2 and examined their associations with clinicopathological factors. RESULTS: Classifications I, II, and III subtypes were INT (7, 10, and 10 cases), PB (43, 37, and 38 cases), MIX (13, 19, and 18 cases), and NOS (12, 9, and 9 cases). Significant differences in disease-free survival among the subtypes were observed in classifications II and III using CDX2; the PB and NOS subtype exhibited shorter survival time compared with INT subtype. In classification III, an association was revealed between advanced T/N stage, poor differentiation, lymphovascular invasion (LVI), the PB and NOS subtypes, and recurrence risk. In classification III, the subtypes differed significantly in T/N stage and LVI. Patients with the PB subtype had advanced T and N stages and a higher incidence of LVI. CONCLUSIONS: Classification using CDX2 revealed subtypes with distinct prognostic significance. Combining CK7 and CDX2 or adding CDX2 to CK7/CK20 is useful for distinguishing subtypes, predicting disease outcomes, and impacting the clinical management of patients with AoV cancer.

Multiple arterial-phase MRI with gadoxetic acid improves diagnosis of hepatocellular carcinoma ≤3.0 cm.

BACKGROUND AND AIMS: Multiple arterial-phase magnetic resonance imaging (MA-MRI) was introduced to overcome the limitations of gadoxetic acid-enhanced MRI, but its clinical impacts on hepatocellular carcinoma (HCC) diagnosis have not been well assessed. We investigated whether MA-MRI with gadoxetic acid could improve the diagnosis of HCC ≤3.0 cm in comparison with single arterial-phase MRI (SA-MRI). METHODS: This retrospective study included 397 patients from two tertiary institutions who underwent gadoxetic acid-enhanced MRI (243 patients with 271 lesions in cohort-1 underwent SA-MRI, and 154 patients with 166 lesions in cohort-2 underwent MA-MRI). The patients had 437 hepatic lesions ≤3.0 cm with pathologic confirmation. The arterial-phase image quality and diagnostic performance of SA-MRI and MA-MRI were analysed and compared. To minimize the effects of selection bias because of potential confounding between the two groups, propensity score-matching was additionally performed. RESULTS: MA-MRI showed a significantly higher percentage of optimal arterial-phase timing (94.2% vs. 74.5%, p < .001) and lower incidence of inadequate examinations (1.3% vs. 5.8%, p = .034) than SA-MRI. MA-MRI had a significantly higher non-rim arterial-phase hyperenhancement (APHE) detection rate (94.9% vs. 85.5%, p = .005) and sensitivity for diagnosing HCC (87.4% vs. 70.0%, p < .001) than SA-MRI, but no significant difference in specificity (92.9% vs. 93.1%, p = .966). In 123 pairs of propensity score-matched patients, MA-MRI had significantly higher sensitivity (89.1% vs. 74.5%, p = .006) than SA-MRI with equal specificity (92.3% vs. 92.3%, p > .999). CONCLUSIONS: Compared with SA-MRI, MA-MRI with gadoxetic acid can detect more non-rim APHE and significantly improve sensitivity for diagnosing HCC ≤3.0 cm, without a significant decrease in specificity.

Decreased Bleeding-Related Adverse Events Using Track Embolization with Gelatin Sponge Slurry after Percutaneous Liver Biopsy: A Propensity Score-Matched Study.

PURPOSE: To evaluate the effectiveness of track embolization using gelatin sponge slurry in percutaneous ultrasound (US)-guided liver biopsy. MATERIALS AND METHODS: Among the 543 patients who underwent percutaneous US-guided liver biopsies between September 2018 and August 2021, 338 who did not undergo track embolization and 105 who underwent track embolization were included in the analysis. All procedures were performed with 18-gauge coaxial core biopsy needles. Patients' laboratory data were reviewed. Patients in both groups were subdivided into the following 2 groups: (a) those with targeted biopsy for a focal liver lesion and (b) those with nontargeted biopsy for a liver parenchyma. Moreover, postbiopsy events, such as transfusion and transarterial embolization, were assessed. To minimize selection bias, propensity score matching (PSM) was performed. RESULTS: After PSM, all factors that could affect bleeding risk were well-matched and well-balanced between the 2 groups (P > .474). In the non-track embolization group, 17 (16.2%) patients experienced major or minor bleeding-related adverse events (AEs). In contrast, in the track embolization group, only 5 (4.8%) patients experienced major or minor bleeding-related AEs, which was significantly lower than that in the non-track embolization group (P = .007). All 5 (4.8%) cases of major bleeding-related AEs were observed in the non-track embolization group (P = .024). CONCLUSIONS: In this study, a retrospective analysis was performed using PSM for percutaneous US-guided liver biopsy. Track embolization using gelatin sponge slurry is significantly superior in the prevention of bleeding-related AEs after US-guided liver biopsy.

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

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

Clinical usefulness of multiple arterial-phase images in gadoxetate disodium-enhanced magnetic resonance imaging: a systematic review and meta-analysis.

OBJECTIVES: The multiple arterial-phase (AP) technique was introduced for liver MRI, but it is not really known if multiple AP MRI (MA-MRI) improves image quality and lesion detection rate on gadoxetate disodium-enhanced MRI in comparison with single AP MRI (SA-MRI). We aimed to determine the clinical usefulness of MA-MRI in comparison with SA-MRI. METHODS: Original articles reporting the percentage of adequate AP imaging and the lesion detection rate on gadoxetate disodium-enhanced MA-MRI were identified in PubMed, EMBASE, and Cochrane Library databases. The pooled percentage of adequate AP imaging and lesion detection rate were calculated using random-effects meta-analysis of single proportions. Subgroup analysis was performed to explain causes of study heterogeneity, and publication bias was evaluated using Egger's test. RESULTS: Of 772 articles screened, 22 studies in 12 articles were included: 18 studies (ten MA-MRI and eight SA-MRI) suitably defined the percentage of adequate AP imaging and four (three MA-MRI and one SA-MRI) defined the lesion detection rate. MA-MRI had 16.1% higher pooled percentage of adequate AP imaging than SA-MRI (94.8% vs. 78.7%, p < 0.01). MA-MRI additionally detected 33.2% of lesions than SA-MRI (83.2% vs. 50.0%, p = 0.06). Substantial study heterogeneity was found in MA-MRI, and the definition of adequate AP imaging, lesion characteristics, and reference standards were significant factors affecting study heterogeneity (p ≤ 0.02). Significant publication bias was found in MA-MRI (p < 0.01) but not in SA-MRI studies (p = 0.87). CONCLUSIONS: Gadoxetate disodium-enhanced MA-MRI may be more clinically useful than SA-MRI, but further study is necessary to validate this finding because of study heterogeneity and publication bias. KEY POINTS: • Multiple arterial-phase MRI (MA-MRI) had a 16.1% higher pooled percentage of adequate AP imaging than single arterial-phase MRI (SA-MRI) (94.8% vs. 78.7%, p < 0.01). • MA-MRI additionally detected an extra 33.2% of lesions compared with SA-MRI (83.2% vs. 50.0%, p = 0.06). • Substantial study heterogeneity and significant publication bias were found across MA-MRI studies.

Transient severe motion artifacts on gadoxetic acid-enhanced MRI: risk factor analysis in 2230 patients.

OBJECTIVES: To determine risk factors for transient severe motion (TSM) artifact on arterial phase of gadoxetic acid-enhanced MRI using a large cohort. METHODS: A total of 2230 patients who underwent gadoxetic acid-enhanced MRI was consecutively included. Two readers evaluated respiratory motion artifact on arterial phase images using a 5-point grading scale. Clinical factors including demographic data, underlying disease, laboratory data, presence of ascites and pleural effusion, and previous experience of gadoxetic acid-enhanced MRI were investigated. Univariable and multivariable logistic regression analyses were performed to determine significant risk factors for TSM. Predictive value of TSM was calculated according to the number of significant risk factors. RESULTS: Overall incidence of TSM was 5.0% (111/2230). In the multivariable analysis, old age (≥ 65 years; odds ratio [OR] = 2.01 [95% CI, 1.31-3.07]), high body mass index (≥ 25 kg/m2; OR = 1.76 [1.18-2.63]), chronic obstructive pulmonary disease (OR = 6.11 [2.32-16.04]), and moderate to severe pleural effusion (OR = 3.55 [1.65-7.65]) were independent significant risk factors for TSM. Presence of hepatitis B (OR = 0.66 [0.43-0.99]) and previous experience of gadoxetic acid-enhanced MRI (OR = 0.52 [0.33-0.83]) were negative risk factors for TSM. When at least one of the significant factors was present, the predictive risk was 5.7% (109/1916), whereas it was 16.3% (17/104) when at least four factors were present. CONCLUSION: Knowing risk factors for transient severe motion artifact on gadoxetic acid-enhanced MRI can be clinically useful for providing diagnostic strategies more tailored to individual patients. KEY POINTS: • Old age, high body mass index, chronic obstructive pulmonary disease, and moderate to severe pleural effusion were independent risk factors for transient severe motion artifact on gadoxetic acid-enhanced MRI. • Patients with hepatitis B or previous experience of gadoxetic acid-enhanced MRI were less likely to show transient severe motion artifact. • As the number of risk factors for transient severe motion artifact increased, the predicted risk for it also showed a tendency to increase.

Hepatic Fat Quantification with the Multi-Material Decomposition Algorithm by Using Low-Dose Non-Contrast Material-Enhanced Dual-Energy Computed Tomography in a Prospectively Enrolled Cohort.

The early diagnosis of hepatic steatosis is important. No study has assessed hepatic fat quantification by using low-dose dual-energy computed tomography (CT). We assessed the accuracy of hepatic fat quantification using the multi-material decomposition (MMD) algorithm with low-dose non-contrast material-enhanced dual-energy CT. We retrospectively reviewed 33 prospectively enrolled patients who had undergone low-dose non-contrast material-enhanced dual-energy CT and magnetic resonance image (MRI) proton density fat fraction (PDFF) on the same day. Percentage fat volume fraction (FVF) images were generated using the MMD algorithm on the low-dose dual-energy CT data. We assessed the correlation between FVFs and MRI-PDFFs by using Spearman's rank correlation. With a 5% cutoff value of MRI-PDFF for fatty liver, a receiver operating characteristic (ROC) curve analysis was performed to identify the optimal criteria of FVF for diagnosing fatty liver. CTDIvol of CT was 2.94 mGy. FVF showed a strong correlation with MRI-PDFF (r = 0.756). The ROC curve analysis demonstrated that FVF ≥ 4.61% was the optimal cutoff for fatty liver. With this cutoff value for diagnosing the fatty liver on low-dose dual-energy CT, the sensitivity, specificity, and area under the curve were 90%, 100%, and 0.987, respectively. The MMD algorithm using low-dose non-contrast material-enhanced dual-energy CT is feasible for quantifying hepatic fat.

Subcentimeter hepatocellular carcinoma in treatment-naïve patients: noninvasive diagnostic criteria and tumor staging on gadoxetic acid-enhanced MRI.

OBJECTIVE: It is controversial to adopt non-invasive diagnostic criteria of hepatocellular carcinoma (HCC) in subcentimeter lesions. This study was aimed to define the optimal noninvasive diagnostic criteria of subcentimeter HCC and to evaluate the effect on tumor staging. METHODS: We included 110 treatment-naïve patients at risk of HCC and eligible for curative treatment who had subcentimeter lesions (n = 136) on gadoxetic acid-enhanced magnetic resonance imaging (MRI) performed between January 2013 and December 2013. Modified diagnostic criteria for subcentimeter HCC were developed using logistic regression analysis. Accuracies of MR staging with and without using the modified criteria were compared by generalized estimating equation test using pathologic staging as reference standards. Subgroup analysis was performed for patients with co-existing HCC ≥ 1 cm (co-HCC). RESULTS: The modified criteria (presence of co-HCC, arterial phase hyperenhancement, and hypointensity on transitional phase [TP]) showed 61.5% (95% CI, 41.6-78.2) of sensitivity and 98.2% (95% CI, 93.0-99.5) of specificity. Including subcentimeter HCCs improved the accuracy of MR staging from 84.5 to 94.5% (p = 0.001). Fifty percent of subcentimeter lesions found in patients with co-HCCs were HCC, whereas 5.9% of them without co-HCCs were HCC (p = 0.001). In the subgroup with co-HCCs, the accuracy of MR staging with subcentimeter HCCs was improved from 69.0% to 92.8% (p = 0.001). CONCLUSIONS: Including subcentimeter HCCs based on the modified diagnostic criteria (co-existing HCC ≥ 1 cm, arterial phase hyperenhancement, and hypointensity on TP) improved MR staging accuracy. KEY POINTS: • Fifty percent of non-benign appearing subcentimeter lesions found in patients with co-HCCs were HCC, whereas 5.9% of them without co-HCCs were HCC (p = 0.001). • Including subcentimeter HCCs improved the accuracy of MR staging from 84.5 to 94.5% (p = 0.001).

Validation of functional liver imaging scores (FLIS) derived from gadoxetic acid-enhanced MRI in patients with chronic liver disease and liver cirrhosis: the relationship between Child-Pugh score and FLIS.

OBJECTIVES: To validate the functional liver imaging score (FLIS) for prediction of hepatic function in gadoxetic acid-enhanced MRI. METHODS: We retrospectively identified 134 patients (88 men, 46 women; mean age, 58.8 years) between January 2015 and December 2018 with the following inclusion criteria: patients diagnosed with liver cirrhosis or chronic liver disease (CLD) who underwent gadoxetic acid-enhanced MRI. Three parameters on hepatobiliary phase images were evaluated for FLIS: liver parenchymal enhancement, biliary excretion, and signal intensity of the portal vein. Patients were classified as CLD (n = 11), Child-Pugh (CP) class A (n = 87), CP B (n = 22), or CP C (n = 14). We assessed the correlation between CP score and both FLIS and its components using Spearman rank correlation. Receiver operating characteristic (ROC) curve analysis was performed to demonstrate the cutoff value of FLIS for differentiating between CP classes. The associations between patient characteristics, serum markers, FLIS, and hepatic decompensation were evaluated with Cox proportional hazard models. RESULTS: FLIS and three FLIS parameters showed strong to very strong correlation with CP score (r = -0.60 to 0.82). ROC curve analysis showed that FLIS ≥ 5 was the optimal cutoff for prediction of CP class A or CLD (sensitivity, 83.7%; specificity, 94.4%; area under the curve [AUC], 0.93). FLIS < 5 was independently associated with the development of first hepatic decompensation in patients with CP A (HR, 50.0; 95% confidence interval, 6.2, 400.4). CONCLUSION: FLIS showed a strong correlation with hepatic function and can stratify the CP class. In addition, FLIS can help prediction for the development of first decompensation. KEY POINTS: • Functional liver imaging scores (FLIS) and its three parameters, derived from hepatobiliary phase image, have strong to very strong correlations with Child-Pugh (CP) scores. • FLIS can stratify patients with chronic liver disease or liver cirrhosis according to CP classification. • Low FLIS is an independent predictor for first hepatic decompensation in patients with CP class A.

CT in the prediction of margin-negative resection in pancreatic cancer following neoadjuvant treatment: a systematic review and meta-analysis.

OBJECTIVES: We aimed to systematically evaluate the diagnostic accuracy of CT-determined resectability following neoadjuvant treatment for predicting margin-negative resection (R0 resection) in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: Original studies with sufficient details to obtain the sensitivity and specificity of CT-determined resectability following neoadjuvant treatment, with a reference on the pathological margin status, were identified in PubMed, EMBASE, and Cochrane databases until February 24, 2020. The identified studies were divided into two groups based on the criteria of R0 resectable tumor (ordinary criterion: resectable PDAC alone; extended criterion: resectable and borderline resectable PDAC). The meta-analytic summary of the sensitivity and specificity for each criterion was estimated separately using a bivariate random-effect model. Summary results of the two criteria were compared using a joint-model bivariate meta-regression. RESULTS: Of 739 studies initially searched, 6 studies (6 with ordinary criterion and 5 with extended criterion) were included for analysis. The meta-analytic summary of sensitivity and specificity was 45% (95% confidence interval [CI], 19-73%; I2 = 88.3%) and 85% (95% CI, 65-94%; I2 = 60.5%) for the ordinary criterion, and 81% (95% CI, 71-87%; I2 = 0.0%) and 42% (95% CI, 28-57%; I2 = 6.2%) for the extended criterion, respectively. The diagnostic accuracy significantly differed between the two criteria (p = 0.02). CONCLUSIONS: For determining resectability on CT, the ordinary criterion might be highly specific but insensitive for predicting R0 resection, whereas the extended criterion increased sensitivity but would decrease specificity. Further investigations using quantitative parameters may improve the identification of R0 resection. KEY POINTS: • CT-determined resectability of PDAC after neoadjuvant treatment using the ordinary criterion shows low sensitivity and high specificity in predicting R0 resection. • With the extended criterion, CT-determined resectability shows higher sensitivity but lower specificity than with the ordinary criterion. • CT-determined resectability with both criteria achieved suboptimal diagnostic performances, suggesting that care should be taken while selecting surgical candidates and when determining the surgical extent after neoadjuvant treatment in patients with PDAC.

Meta-analysis of MRI for the diagnosis of liver metastasis in patients with pancreatic adenocarcinoma.

BACKGROUND: Determining if a given patient with primary pancreatic adenocarcinoma (PDA) has hepatic metastasis is important for treatment planning. Several previous studies reported on the diagnostic performance of MRI for liver metastasis in patients with PDA. But the reported data are quite variable. PURPOSE: To systematically determine the diagnostic performance of MRI for liver metastasis in patients with PDA, including comparing it with computed tomography (CT). STUDY TYPE: Systemic review and meta-analysis. SUBJECTS: In all, 457 patients from five eligible articles. FIELD STRENGTH/SEQUENCE: Conventional MR sequences with or without contrast enhancement at 1.5T and 3T. ASSESSMENT: Two reviewers independently performed the data extraction. The reviewers identified and reviewed the original articles reporting the diagnostic performance of MRI for liver metastases in patients with PDA, including those articles making comparisons with CT. STATISTICAL TESTS: Meta-analytic summary sensitivity and specificity were calculated on a per-patient basis using a bivariate random effects model. We compared the meta-analytic summary sensitivity and specificity between MRI and CT. RESULTS: The meta-analytic summary sensitivity and specificity were 85% (95% confidence interval [CI], 74-92%; I2 = 0%) and 98% (95% CI, 78-100%; I2 = 85%), respectively. In comparison with CT, MRI showed a higher sensitivity (85% vs. 75%) but similar specificity (98% vs. 94%). DATA CONCLUSION: MRI had good overall diagnostic performance for liver metastasis in patients with PDA, with a higher sensitivity than CT. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:1737-1744.

Vesical Imaging-Reporting and Data System for Multiparametric MRI to Predict the Presence of Muscle Invasion for Bladder Cancer.

BACKGROUND: The Vesical Imaging-Reporting and Data System (VI-RADS) is a newly developed system of bladder cancer staging with multiparametric MRI (mpMRI), which can be used to predict the presence of muscle invasion for bladder cancer. PURPOSE: To evaluate the accuracy of three mpMRI series (T2 WI, diffusion-weighted imaging [DWI], and dynamic contrast-enhanced image [DCEI]) and VI-RADS for diagnosing the muscle invasive bladder cancer (MIBC). STUDY TYPE: Retrospective. POPULATION: In all, 66 pathologically proven bladder cancers in 32 patients. FIELD STRENGTH/SEQUENCE: Before the diagnostic MRI with an intramuscular antispasmodic agent, optimal bladder distension was confirmed. 3.0T MRI with T2 WI, DWI, and DCEI. ASSESSMENT: Three reviewers independently assessed and scored the bladder cancers in T2 WI, DWI, and DCEI using a five-point score system. Based on the scores in the three sequences, reviewers scored each bladder cancer with reference to VI-RADS categories. We evaluated the diagnostic performance of each of three mpMRI sequences and the final VI-RADS categorization for diagnosing MIBC. STATISTICAL TESTS: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the area under the curve (AUC) of each of three sequences separately and VI-RADS categorization for diagnosing the MIBC. RESULTS: The diagnostic performances of each of the three mpMRI series and VI-RADS for diagnosing MIBC were excellent. Especially using the optimal cutoff score >3 for predicting MIBC on DWI, DCEI, and VI-RADS, the sensitivity, specificity, PPV, NPV, and AUC values were 90% (95% confidence interval [CI]: 0.56, 1.00), 100% (95% CI: 0.94, 1.00), 100% (95% CI: 0.66. 1.00), 98.3% (95% CI: 0.91, 1.00), and 0.95, respectively. DATA CONCLUSION: mpMRI based on VI-RADS can stratify patients with bladder cancer according to the presence of muscle invasion. LEVEL OF EVIDENCE: 3. TECHNICAL EFFICACY STAGE: 2. J. Magn. Reson. Imaging 2020;52:1249-1256.

Is it worth carrying out ultrasound-magnetic resonance imaging fusion targeted biopsy on Prostate Imaging Reporting and Data System score 3 prostate lesions?

OBJECTIVES: To evaluate the use of ultrasound-magnetic resonance imaging fusion targeted biopsy for Prostate Imaging Reporting and Data System 3 prostate lesions. METHODS: We identified 227 patients with prostate-specific antigen levels ≥4 ng/mL who underwent concurrent transrectal ultrasound-guided systemic biopsy and fusion biopsy. Suspicious prostatic lesions were assessed in accordance with Prostate Imaging Reporting and Data System version 2.0. We compared ultrasound-magnetic resonance imaging fusion targeted biopsy and ultrasound-guided biopsy cancer detection rates in Prostate Imaging Reporting and Data System 3 lesions with those in other Prostate Imaging Reporting and Data System score lesions. In Prostate Imaging Reporting and Data System 3 patients, we identified clinically significant prostate cancer risk factors by logistic regression analysis. RESULTS: In total, 2770 transrectal ultrasound-guided and 867 fusion biopsy cores were obtained; where 332 (12.0%) and 194 (22.4%) cores were prostate cancer-positive, respectively (P < 0.001). The fusion biopsy cancer detection rate (8.0%) in Prostate Imaging Reporting and Data System 3 lesions was similar to that in Prostate Imaging Reporting and Data System 1-2 lesions, but was lower than that of Prostate Imaging Reporting and Data System 4 (30.0%; P < 0.001) and 5 lesions (65.2%; P < 0.001), and ultrasound-guided biopsy (12.0%; P = 0.023). For clinically significant prostate cancer detection, fusion biopsy in Prostate Imaging Reporting and Data System 3 lesions was inferior to that in Prostate Imaging Reporting and Data System 4 and 5 lesions, and non-superior to ultrasound-guided biopsy. Cancer detection rate trends were similar in biopsy-naïve patients. In Prostate Imaging Reporting and Data System 3 patients, prostate-specific antigen density was the only significant predictor of clinically significant prostate cancer. CONCLUSIONS: The present findings do not support the use of ultrasound-magnetic resonance imaging fusion targeted biopsy for Prostate Imaging Reporting and Data System 3 lesions. Thus, we recommend the use of transrectal ultrasound-guided systemic biopsy for patients with Prostate Imaging Reporting and Data System 3 index lesions.

Modified CAIPIRINHA-VIBE without view-sharing on gadoxetic acid-enhanced multi-arterial phase MR imaging for diagnosing hepatocellular carcinoma: comparison with the CAIPIRINHA-Dixon-TWIST-VIBE.

PURPOSE: We evaluated the detection rate and degree of motion artifact of the modified CAIPIRINHA-VIBE (mC-VIBE) without view-sharing and compare them with the CAIPIRINHA-Dixon-TWIST-VIBE (CDT-VIBE) with view-sharing on multi-arterial gadoxetic acid-enhanced liver MRI in the assessment of hepatocellular carcinoma (HCC). MATERIAL AND METHODS: We retrospectively identified 114 pathological-proven hepatic tumors in 114 patients with risk of HCC who underwent multi-arterial gadoxetic acid-enhanced MRI between June 2016 and June 2018. All patients underwent triple arterial phase imaging using the mC-VIBE without view-sharing (54 patients; 49 HCCs and 5 non-HCCs) or the CDT-VIBE with view-sharing (60 patients; 55 HCCs and 5 non-HCCs). We compared the detection rate of two sequences for HCC, with reference to LI-RADS.V.2017. We also compared the mean motion scores and proportions of transient severe motion (TSM) in two sequences. RESULT: For the examination using the mC-VIBE, the HCC-detection rate was significantly higher, compared with that using CDT-VIBE (93.9% [46/49] vs 80.0% [44/55], respectively; p = 0.047). For the examination with the mC-VIBE, mean motion scores were significantly lower compared with those of CDT-VIBE for all multi-arterial phases (1.21, 1.19, and 1.15 vs. 1.82, 1.85, and 1.84, respectively; p < 0.001 for all three comparisons). The proportion of TSM in the CDT-VIBE was significantly higher than that in the mC-VIBE (15.0% [9/60] vs 0.0% [0/54], respectively; p = 0.003). CONCLUSION: In multi-arterial phase gadoxetic acid-enhanced MRI, the mC-VIBE sequence without view-sharing has slightly higher HCC-detection rate and fewer motion artifacts compared with CDT-VIBE with view-sharing. KEY POINTS: • Multi-arterial phase using the mC-VIBE without view-sharing can overcome motion artifacts, resulting in providing optimal arterial phase imaging. • The HCC-detection rate is slightly higher with the mC-VIBE vs. CAIPIRINHA-Dixon-TWIST-VIBE with view-sharing (CDT-VIBE). • View-sharing of CDT-VIBE in the multi-arterial phase is associated with increased frequency of TSM.

Diagnostic performance of [18F]FDG-PET/MRI for liver metastasis in patients with primary malignancy: a systematic review and meta-analysis.

OBJECTIVES: To systematically determine the diagnostic accuracy of 18-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging ([18F]FDG-PET/MRI) for the detection of liver metastases and evaluate the sources of heterogeneity in the reported results. METHODS: PubMed and EMBASE databases were searched up until December 31, 2017, to identify original research studies reporting the diagnostic performance (Se and Sp) of PET/MRI for liver metastases, in comparison with PET/CT. Study quality was assessed using QUADAS-2. The summary Se and Sp of the studies were estimated using hierarchical modeling methods. To determine causes of study heterogeneity, the presence of a threshold effect was analyzed, and meta-regression analysis was performed. RESULTS: Of 546 articles screened, eight suitable articles were identified, with seven for per-lesion analysis, and four for per-patient analysis. The meta-analytic summary Se and Sp for per-patient-based analysis were 99.2% (95% CI, 31.4-100.0%, I2 = 89.4%) and 98.6% (95% CI, 84.0-99.9%, I2 = 0.0%), respectively, while for per-lesion-based analysis they were 95.4% (95% CI, 78.3-99.2%, I2 = 99.7%) and 99.3% (95% CI, 93.8-99.9%, I2 = 96.5%). PET/MRI showed higher Se (95.4% vs. 68.3%) and Sp (99.3% vs. 95.8%) than PET/CT. Meta-regression analysis showed five significant factors affecting study heterogeneity: study subject characteristics, study design, MRI technique (DWI, HBP after injection of liver-specific contrast media), imaging review method, and reference standard. CONCLUSION: The diagnostic accuracy of [18F]FDG-PET/MRI for liver metastasis was high overall, but substantial heterogeneity was found. Further randomized controlled studies or prospective studies are needed to investigate the role of PET/MRI in liver metastasis in comparison with PET/CT. KEY POINTS: • [ 18 F]FDG-PET/MRI has high meta-analytic Se and Sp for the diagnosis of liver metastasis. • PET/MRI using DWI and HBP images significantly increased diagnostic accuracy. • Study heterogeneity was associated with subject characteristics, study design, MRI technique, image review method, and reference standard.

Low-Dose CT With the Adaptive Statistical Iterative Reconstruction V Technique in Abdominal Organ Injury: Comparison With Routine-Dose CT With Filtered Back Projection.

OBJECTIVE. The purpose of this study was to evaluate and compare the diagnostic performance and image quality of low-dose CT performed with adaptive statistical iterative reconstruction (ASIR)-V with those of routine-dose CT with filtered back projection (FBP) in the evaluation of abdominal organ injury. MATERIALS AND METHODS. The study enrolled 197 patients with trauma who underwent multiphase abdominal CT, including routine-dose portal venous phase imaging with FBP and low-dose delayed phase imaging with 50% ASIR-V. The presence of abdominal organ injuries (liver, spleen, pancreas, kidney) was reviewed, and injuries were graded according to American Association for the Surgery of Trauma (AAST) scales. CT detection rates of organ injury and AAST grading with the two protocols were compared by McNemar test. Subjective analysis of image noise and artifacts and objective analysis of CT noise were performed by unpaired t test. RESULTS. Compared with the routine-dose protocol, the low-dose protocol enabled an mean dose reduction of 59.8%. The detection rates and diagnostic performance of AAST grading did not differ significantly between the two protocols (detection rate, p = 0.289; diagnostic performance, p > 0.999). Objective image noise was significantly less with the low-dose protocol than with the routine-dose protocol (p < 0.001). Subjective imaging artifacts were similar between the low-dose and routine-dose protocols (p = 0.539). CONCLUSION. Compared with routine-dose protocol with FBP, low-dose CT with ASIR-V was useful for assessing multiorgan abdominal injury without impairing image quality.

Pancreatic Cancer CT: Prediction of Resectability according to NCCN Criteria.

Purpose To evaluate the diagnostic performance of CT in the determination of pancreatic cancer resectability according to the National Comprehensive Cancer Network (NCCN) criteria to predict R0 resection. Materials and Methods Structured reports of pancreatic CT clinically prepared by board-certified abdominal radiologists from January 2014 to March 2017 were retrospectively reviewed to assess resectability (resectable, borderline resectable, or unresectable) according to NCCN criteria (version 1.2017) in 616 patients (369 men, 247 women; mean age, 63 years ± 10 [standard deviation]) with pancreatic cancer. Negative resection margin (R0) rates were assessed based on CT resectability status in patients who underwent upfront surgery. R0 resection-associated factors were identified by using logistic regression analysis. Results In 371 patients who underwent surgery, R0 resection rates were 73% (171 of 235), 55% (57 of 104), and 16% (five of 32) for resectable, borderline resectable, and unresectable disease, respectively (P < .001). At multivariable analysis, tumor diameter larger than 4 cm (P < .001) and abutment to the portomesenteric vein (P < .001) were significantly associated with margin-positive resection in patients with resectable disease at CT. R0 resection rates were 80% (123 of 154) for resectable disease without portomesenteric vein abutment, 59% (48 of 81) for resectable disease with portomesenteric vein abutment, 83% (57 of 69) for resectable disease 2 cm or smaller, and 29% (five of 17) for tumors larger than 4 cm. Conclusion CT resectability is used to stratify patients with pancreatic cancer according to the possibility of R0 resection. Larger tumor size and tumor abutment to the portomesenteric vein are associated with margin-positive resection in patients with resectable pancreatic cancer. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Fowler in this issue.

Ultra-low-dose lung screening CT with model-based iterative reconstruction: an assessment of image quality and lesion conspicuity.

Background Reducing radiation dose inevitably increases image noise, and thus, it is important in low-dose computed tomography (CT) to maintain image quality and lesion detection performance. Purpose To assess image quality and lesion conspicuity of ultra-low-dose CT with model-based iterative reconstruction (MBIR) and to determine a suitable protocol for lung screening CT. Material and Methods A total of 120 heavy smokers underwent lung screening CT and were randomly and equally assigned to one of five groups: group 1 = 120 kVp, 25 mAs, with FBP reconstruction; group 2 = 120 kVp, 10 mAs, with MBIR; group 3 = 100 kVp, 15 mAs, with MBIR; group 4 = 100 kVp, 10 mAs, with MBIR; and group 5 = 100 kVp, 5 mAs, with MBIR. Two radiologists evaluated intergroup differences with respect to radiation dose, image noise, image quality, and lesion conspicuity using the Kruskal-Wallis test and the Chi-square test. Results Effective doses were 61-87% lower in groups 2-5 than in group 1. Image noises in groups 1 and 5 were significantly higher than in the other groups ( P < 0.001). Overall image quality was best in group 1, but diagnostic acceptability of overall image qualities in groups 1-3 was not significantly different (all P values > 0.05). Lesion conspicuities were similar in groups 1-4, but were significantly poorer in group 5. Conclusion Lung screening CT with MBIR obtained at 100 kVp and 15 mAs enables a ∼60% reduction in radiation dose versus low-dose CT, while maintaining image quality and lesion conspicuity.

Survival benefit of concurrent chemoradiotherapy for advanced ampulla of Vater cancer.

BACKGROUND: Currently, there is no standard adjuvant therapy for patients with resected ampulla of Vater (AoV) cancer. AIM: To evaluate the effectiveness of adjuvant concurrent chemoradiotherapy (CCRT) in patients with advanced AoV cancer who underwent curative resection. METHODS: This single-centered, retrospective study included 29 patients with advanced AoV cancer who underwent pancreaticoduodenectomy between 2006 and 2018. The impact of CCRT on advanced AoV cancer was analyzed. RESULTS: The 1-, 3-, and 5-yr recurrence-free survival (RFS) rates for patients with advanced AoV cancer were 82.8%, 48.3%, and 40.8%, respectively, and the overall survival (OS) rates were 89.7%, 62.1%, and 51.7%, respectively. Lymphovascular invasion was found to be a significant risk factor for RFS and OS in patients with advanced AoV cancer in the univariate analysis, whereas T stage and lymph node metastasis were significantly associated with OS in the multivariate analysis. Compared to the patients who did not receive adjuvant CCRT, those who received adjuvant CCRT did not show statistically significant improvements in the RFS and OS, although they had a significantly lower average age and significantly higher platelet-to-lymphocyte ratio. CONCLUSION: Adjuvant CCRT did not improve survival outcomes in patients with advanced AoV cancer. These findings contribute to existing knowledge on the effectiveness of CCRT in this patient population and provide important insights for clinical decision-making.