Utility of Thin-slice Fat-suppressed Single-shot T2-weighted MR Imaging with Deep Learning Image Reconstruction as a Protocol for Evaluating the Pancreas.

PURPOSE: To compare the utility of thin-slice fat-suppressed single-shot T2-weighted imaging (T2WI) with deep learning image reconstruction (DLIR) and conventional fast spin-echo T2WI with DLIR for evaluating pancreatic protocol. METHODS: This retrospective study included 42 patients (mean age, 70.2 years) with pancreatic cancer who underwent gadoxetic acid-enhanced MRI. Three fat-suppressed T2WI, including conventional fast-spin echo with 6 mm thickness (FSE 6 mm), single-shot fast-spin echo with 6 mm and 3 mm thickness (SSFSE 6 mm and SSFSE 3 mm), were acquired for each patient. For quantitative analysis, the SNRs of the upper abdominal organs were calculated between images with and without DLIR. The pancreas-to-lesion contrast on DLIR images was also calculated. For qualitative analysis, two abdominal radiologists independently scored the image quality on a 5-point scale in the FSE 6 mm, SSFSE 6 mm, and SSFSE 3 mm with DLIR. RESULTS: The SNRs significantly improved among the three T2-weighted images with DLIR compared to those without DLIR in all patients (P < 0.001). The pancreas-to-lesion contrast of SSFSE 3 mm was higher than those of the FSE 6 mm (P < 0.001) and tended to be higher than SSFSE 6 mm (P = 0.07). SSFSE 3 mm had the highest image qualities regarding pancreas edge sharpness, pancreatic duct clarity, and overall image quality, followed by SSFSE 6 mm and FSE 6 mm (P < 0.0001). CONCLUSION: SSFSE 3 mm with DLIR demonstrated significant improvements in SNRs of the pancreas, pancreas-to-lesion contrast, and image quality more efficiently than did SSFSE 6 mm and FSE 6 mm. Thin-slice fat-suppressed single-shot T2WI with DLIR can be easily implemented for pancreatic MR protocol.

Rim Enhancement on Contrast-Enhanced CT as a Predictor of Prognosis in Patients with Pancreatic Ductal Adenocarcinoma.

This study investigated the utility of imaging features, such as rim enhancement on contrast-enhanced CT (CECT), in predicting the prognosis of pancreatic ductal adenocarcinoma (PDAC). This retrospective study included 158 patients (84 men; mean age, 68 years) with pathologically confirmed PDAC. The following imaging features were evaluated on CECT by two radiologists: tumor size, tumor attenuation, and the presence of rim enhancement. Cox proportional hazards analysis was performed to identify the imaging and clinicopathological features for predicting disease-free survival (DFS) and overall survival (OS). Pathological features were compared with the presence of rim enhancement. Among the 158 patients, 106 (67%) underwent curative surgery (surgery group) and 52 (33%) received conservative treatment (non-surgery group). Rim enhancement was observed more frequently in the non-surgery group than in the surgery group (44% vs. 20%; p < 0.001). Rim enhancement showed significant associations with shorter DFS and OS in the surgery group (hazard ratios (HRs), 3.03 and 2.99; p < 0.001 and p = 0.003, respectively), whereas tumor size showed significant associations with shorter OS (HR per 1 mm increase, 1.08; p < 0.001). PDACs with rim enhancement showed significant associations with higher histological tumor grades (p < 0.001). PDAC with rim enhancement on CECT could predict poorer prognosis and more aggressive tumor grades.

Evaluation and Prediction of Post-Hepatectomy Liver Failure Using Imaging Techniques: Value of Gadoxetic Acid-Enhanced Magnetic Resonance Imaging.

Despite improvements in operative techniques and perioperative care, post-hepatectomy liver failure (PHLF) remains the most serious cause of morbidity and mortality after surgery, and several risk factors have been identified to predict PHLF. Although volumetric assessment using imaging contributes to surgical simulation by estimating the function of future liver remnants in predicting PHLF, liver function is assumed to be homogeneous throughout the liver. The combination of volumetric and functional analyses may be more useful for an accurate evaluation of liver function and prediction of PHLF than only volumetric analysis. Gadoxetic acid is a hepatocyte-specific magnetic resonance (MR) contrast agent that is taken up by hepatocytes via the OATP1 transporter after intravenous administration. Gadoxetic acid-enhanced MR imaging (MRI) offers information regarding both global and regional functions, leading to a more precise evaluation even in cases with heterogeneous liver function. Various indices, including signal intensity-based methods and MR relaxometry, have been proposed for the estimation of liver function and prediction of PHLF using gadoxetic acid-enhanced MRI. Recent developments in MR techniques, including high-resolution hepatobiliary phase images using deep learning image reconstruction and whole-liver T1 map acquisition, have enabled a more detailed and accurate estimation of liver function in gadoxetic acid-enhanced MRI.

Added value of contrast enhancement boost images in routine multiphasic contrast-enhanced CT for the diagnosis of small (<20 mm) hypervascular hepatocellular carcinoma.

PURPOSE: To investigate the added value of contrast enhancement boost (CE-boost) images in multiphasic contrast-enhanced CT (CE-CT) for diagnosing small (<20 mm) hypervascular hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This retrospective study included 69 patients (age, 74 ± 8 years; 52 men) with 70 hypervascular HCCs (<20 mm) who underwent multiphasic CE-CT (pre-contrast, late arterial phase [LAP], portal venous phase [PVP], and equilibrium phase). Two types of CE-boost images were generated by subtracting PVP from LAP (LA-PV) images and LAP from PVP (PV-LA) images to enhance the contrast effect of hepatic arterial and portal venous perfusion more selectively. Tumor-to-liver contrast-to-noise ratios (CNRs) in CE-boost images were compared with those in CE-CT images using the Wilcoxon signed-rank test. Two independent readers reviewed the imaging datasets: CE-CT alone and CE-CT with CE-boost images. The diagnostic performance of each dataset was compared using jackknife alternative free-response receiver operating characteristics (JAFROC-1). RESULTS: The tumor-to-liver CNRs in the LA-PV (6.4 ± 3.0) and PV-LA (-3.3 ± 2.1) images were greater than those in the LAP (3.2 ± 1.7) and PVP images (-1.1 ± 1.4) (p <.001 for both). The reader-averaged figures of merit were 0.751 for CE-CT alone and 0.807 for CE-CT with CE-boost images (p <.001). Sensitivities increased by adding CE-boost images for both readers (p <.001 and = 0.03), while positive predictive values were equivalent (p >.99). CONCLUSION: Adding CE-boost images to multiphasic CE-CT can improve the diagnostic accuracy and sensitivity for small hypervascular HCC by increasing the tumor-to-liver CNR.

Transarterial Chemoebolization in Hepatocellular Carcinoma: A Binational Japanese-German Study.

Objective: The purpose of this study was to investigate outcomes of transarterial chemoembolization (TACE) in treating hepatocellular carcinoma (HCC) comparing the different approaches used in Germany and Japan. Methods: This binational IRB-approved retrospective dual-center study included a total of 94 HCC patients subdivided in a German and a Japanese cohort. For each patient, liver and tumor volumetry was performed using computed tomography (CT) and magnetic resonance imaging (MRI). Furthermore, a comprehensive risk profile, including body constitution and liver and kidney function was established. Primary endpoints were progression-free and overall survival (PFS/OS). Results: PFS in the German cohort was 168 vs 224d in the Japanese cohort (p=0.640). When subdivided by BCLC stage, no significant differences were reported (p=0.160-0.429). OS was significantly longer in the Japanese cohort with 856 vs. 303d (p<0.001). OS for BCLC A was significantly longer in the Japanese cohort (1960 vs. 428d; p<0.001), while survival rates did not differ significantly in BCLC B (785 vs 330d; p=0.067) and C-stages (208 vs 302d; p=0.186). Older age (p=0.034), poorer liver/kidney function (p=0.025-0-035), and a higher liver/tumor ratio (p<0.001) were found to correlate with shorter survival. ECOG scores were significantly higher in the German cohort (p=0.002). Conclusion: While OS is longer in TACE-treated patients in the Japanese cohort compared to the German cohort, the two approaches seem to be equally effective as PFS does not differ significantly. The different survival rates may be caused by the different clinical performance status of the selected collectives. In very early and early stage HCC, TACE in Japan seems to be an effective treatment option while in Germany for patients in those stages TACE remains a second-line option for patients not available for surgery or ablation.

Abbreviated Gadoxetic Acid-Enhanced MRI for the Detection of Liver Metastases in Patients With Potentially Resectable Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Gadoxetic acid-enhanced magnetic resonance imaging (MRI) is useful in detecting liver metastases from pancreatic ductal adenocarcinoma (PDAC). However, the long examination time limits its utility in the initial workup of patients with PDAC. PURPOSE: To evaluate the incremental value of an abbreviated gadoxetic acid-enhanced MRI for the detection of liver metastases in patients with PDAC. STUDY TYPE: Retrospective. POPULATION: Patients (N = 130) with potentially resectable PDAC (women, 58 [44.6%]). FIELD STRENGTH/SEQUENCE: 1.5 T and 3 T; gradient dual-echo T1-weighted (in-phase and opposed-phase), fat-suppressed fast spin-echo T2-weighted, single-shot echo-planar diffusion-weighted, and three-dimensional fat-suppressed T1-weighted gradient-echo dynamic contrast-enhanced and hepatobiliary phase sequences, as well as contrast-enhanced computed tomography (CECT). ASSESSMENT: Three radiologists independently reviewed three different image sets to detect liver metastases: set 1, CECT alone; set 2, CECT and abbreviated MRI comprising fat-suppressed T2-weighted, diffusion-weighted, and hepatobiliary phase images; and set 3, CECT and standard gadoxetic acid-enhanced MRI. STATISTICAL TESTS: Figure of merit (FOM) was compared using the jackknife alternative free-response receiver operating characteristics, and other per-lesion and per-patient diagnostic parameters for each image set were compared using McNemar's and Fisher's test. P < 0.05 was considered statistically significant. RESULTS: A total of 43 liver metastases were identified in 13 patients. Reader-averaged FOM to detect liver metastases were significantly higher for sets 2 (0.884) and 3 (0.886) than for set 1 (0.609), while they were comparable between sets 2 and 3 (P = 0.96). The mean per-patient sensitivities, negative predictive values, and accuracies were significantly higher for sets 2 and 3 than for set 1, while those between sets 2 and 3 were not significantly different (not applicable, P > 0.99, and P > 0.99, respectively). DATA CONCLUSION: Gadoxetic acid-enhanced MRI combined with CECT had higher diagnostic performance than CECT alone for the detection of liver metastases in patients with PDAC. The incremental values were comparable for the abbreviated MRI and standard MRI. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

Highlights of the 12th Japan Bioanalysis Forum Symposium.

Approximately 300 people associated with pharmaceutical industries, contractors, academic institutions and regulatory authorities attended the 12th Japan Bioanalysis Forum Symposium. The webinar was conducted from 9 to 11 March 2021. The theme of the symposium was 'for the next generation', and the event provided 'an opportunity for young researchers in bioanalysis (including students)' and 'an opportunity to discuss new frontiers of bioanalysis'. The speakers focused on hot topics of bioanalysis, including biomarker analysis, patient centric sampling, virtual clinical trials, gene therapy, cancer genome medicine and therapeutic middle molecules. The symposium presented a platform for the discussion of the prospects and challenges facing bioanalysts working in the field of pharmacokinetics. This report presents the key issues discussed.

CT Body Composition of Sarcopenia and Sarcopenic Obesity: Predictors of Postoperative Complications and Survival in Patients with Locally Advanced Esophageal Adenocarcinoma.

BACKGROUND: To assess the impact of body composition imaging biomarkers in computed tomography (CT) on the perioperative morbidity and survival after surgery of patients with esophageal cancer (EC). METHODS: Eighty-five patients who underwent esophagectomy for locally advanced EC after neoadjuvant therapy between 2014 and 2019 were retrospectively enrolled. Pre- and postoperative CT scans were used to assess the body composition imaging biomarkers (visceral (VAT) and subcutaneous adipose tissue (SAT) areas, psoas muscle area (PMA) and volume (PMV), total abdominal muscle area (TAMA)). Sarcopenia was defined as lumbar skeletal muscle index (LSMI) ≤38.5 cm2/m2 in women and ≤52.4 cm2/m2 in men. Patients with a body mass index (BMI) of ≥30 were considered obese. These imaging biomarkers were correlated with major complications, anastomotic leakage, postoperative pneumonia, duration of postoperative hospitalization, disease-free survival (DFS), and overall survival (OS). RESULTS: Preoperatively, sarcopenia was identified in 58 patients (68.2%), and sarcopenic obesity was present in 7 patients (8.2%). Sarcopenic patients were found to have an elevated risk for the occurrence of major complications (OR: 2.587, p = 0.048) and prolonged hospitalization (32 d vs. 19 d, p = 0.040). Patients with sarcopenic obesity had a significantly higher risk for postoperative pneumonia (OR: 6.364 p = 0.018) and a longer postoperative hospital stay (71 d vs. 24 d, p = 0.021). Neither sarcopenia nor sarcopenic obesity was an independent risk factor for the occurrence of anastomotic leakage (p > 0.05). Low preoperative muscle biomarkers (PMA and PMV) and their decrease (ΔPMV and ΔTAMA) during the follow-up period significantly correlated with shorter DFS and OS (p = 0.005 to 0.048). CONCLUSION: CT body composition imaging biomarkers can identify high-risk patients with locally advanced esophageal cancer undergoing surgery. Sarcopenic patients have a higher risk of major complications, and patients with sarcopenic obesity are more prone to postoperative pneumonia. Sarcopenia and sarcopenic obesity are both subsequently associated with a prolonged hospitalization. Low preoperative muscle mass and its decrease during the postoperative follow-up are associated with lower DFS and OS.

Bioanalysis of therapeutic monoclonal antibody by peptide adsorption-controlled LC-MS.

Aim: We aimed to develop an easy, low-cost and versatile mass spectrometric method for the bioanalysis of a therapeutic monoclonal antibody (mAb) in human serum that employs peptide adsorption-controlled (PAC)-LC/MS using selected reaction monitoring mode (LC-MS/MS-SRM). Materials & methods: Rituximab was used as a model mAb. To apply the method to human serum samples, a peptide of the complementarity-determining region was selected as the surrogate peptide. The usefulness of PAC-LC-MS/MS-SRM was evaluated by a collaborative study. Results: The calibration curve ranged from 0.5 (or 1.0) to 1000.0 µg/ml. The selectivity, linearity, accuracy and precision met the predefined acceptance criteria. Conclusion: Our method could be a useful bioanalytical method for the quantification of mAbs in clinical samples.

Prediction of post-hepatectomy liver failure using gadoxetic acid-enhanced magnetic resonance imaging for hepatocellular carcinoma with portal vein invasion.

PURPOSE: Accurate prediction of post-hepatectomy liver failure (PHLF) is important in advanced hepatocellular carcinoma (HCC). We aimed to retrospectively evaluate the utility of gadoxetic acid-enhanced MRI for predicting PHLF in patients who underwent anatomic hepatectomy for HCC with portal vein invasion. METHODS: Forty-one patients (32 men, 9 women) were included. Hepatobiliary-phase MR images were acquired 20 min after injection of gadoxetic acid using a 3D fat-suppressed T1-weighted spoiled gradient-echo sequence. Liver-spleen ratio (LSR), remnant hepatocellular uptake index (rHUI), and HUI were calculated. The severity of PHLF was defined according to the International Study Group of Liver Surgery. Differences in LSR between the resected liver and the remnant liver, and HUI and rHUI/HUI between no/mild and severe PHLF were compared using the Wilcoxon signed-rank test and Wilcoxon rank-sum test, respectively. Univariate and multivariate logistic regression analyses were performed to identify predictors of severe PHLF. Areas under the receiver operating characteristic curves (AUCs) of rHUI and rHUI/HUI were calculated for predicting severe PHLF. RESULTS: Nine patients developed severe PHLF. LSR of the remnant liver was significantly higher than that of the resected liver (P < 0.001). Severe PHLF demonstrated significantly lower rHUI (P < 0.001) and rHUI/HUI (P < 0.001) compared with no/mild PHLF. Multivariate logistic regression analysis showed that decreased rHUI (P = 0.012, AUC=0.885) and rHUI/HUI (P = 0.002, AUC=0.852) were independent predictors of severe PHLF. CONCLUSION: Gadoxetic acid-enhanced MRI can be a promising noninvasive examination for assessing global and regional liver function, allowing estimation of the functional liver remnant and accurate prediction of severe PHLF before hepatic resection.