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Objectives: This study evaluated pretreatment magnetic resonance imaging (MRI)–detected extramural venous invasion (pmrEMVI) as a predictor of survival after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC). Materials and methods: Medical records of 1184 patients with rectal adenocarcinoma who underwent TME between January 2011 and December 2016 were reviewed. MRI data were collected from a computerized radiologic database. Cox proportional hazards analysis was used to assess local, systemic recurrence, and disease-free survival risk based on pretreatment MRI-assessed tumor characteristics. After propensity score matching (PSM) for pretreatment MRI features, nCRT therapeutic outcomes according to pmrEMVI status were evaluated. Cox proportional hazards analysis was used to identify risk factors for early recurrence in patients receiving nCRT. Results: Median follow-up was 62.8 months. Among all patients, the presence of pmrEMVI was significantly associated with worse disease-free survival (DFS; HR 1.827, 95% CI 1.285–2.597, p = 0.001) and systemic recurrence (HR 2.080, 95% CI 1.400–3.090, p < 0.001) but not local recurrence. Among patients with pmrEMVI, nCRT provided no benefit for oncological outcomes before or after PSM. Furthermore, pmrEMVI(+) was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT. Conclusions: pmrEMVI is a poor prognostic factor for DFS and SR in patients with non-metastatic rectal cancer and also serves as a predictive biomarker of poor DFS and SR following nCRT in LARC. Therefore, for patients who are positive for pmrEMVI, consideration of alternative treatment strategies may be warranted. Clinical relevance statement: This study demonstrated the usefulness of pmrEMVI as a predictive biomarker for nCRT, which may assist in initial treatment decision-making in patients with non-metastatic rectal cancer. Key Points: • Pretreatment MRI-detected extramural venous invasion (pmrEMVI) was significantly associated with worse disease-free survival and systemic recurrence in patients with non-metastatic rectal cancer. • pmrEMVI is a predictive biomarker of poor DFS following nCRT in patients with LARC. • The presence of pmrEMVI was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT. [ABSTRACT FROM AUTHOR]

Background: Despite the extensive implementation of an organized multidisciplinary team (MDT) approach in cancer treatment, there is little evidence regarding the optimal format of MDT. We aimed to investigate the impact of patient participation in MDT care on the actual application rate of metastasis‐directed local therapy. Methods: We identified all 1211 patients with locally advanced rectal cancer treated with neoadjuvant radiochemotherapy at a single institution from 2006 to 2018. Practice patterns, tumor burden and OMD state were analyzed in recurrent, metastatic cases. Results: With a median follow‐up of 60.7 months, 281 patients developed metastases, and 96 (34.2%), 92 (32.7%), and 93 (33.1%) patients had 1, 2–5, and >5 lesions, respectively. In our study, 27.1% were managed in the MDT clinic that mandated the participation of at least four to five board‐certified multidisciplinary experts and patients in decision‐making processes, while the rest were managed through diverse MDT approaches such as conferences, tumor board meetings, and discussions conducted via phone calls or email. Management in MDT clinic was significantly associated with more use of radiotherapy (p = 0.003) and more sessions of local therapy (p < 0.001). At the time of MDT clinic, the number of lesions was 1, 2–5, and >5 in 9 (13.6%), 35 (53.1%), and 19 (28.8%) patients, respectively. The most common states were repeat OMD (28.8%) and de novo OMD (27.3%), followed by oligoprogression (15%) and induced OMD (10.6%). Conclusion: Our findings suggest that active involvement of patients and radiation oncologists, and surgeons in MDT care has boosted the probability of using local therapies for various types of OMD throughout the course of the disease. [ABSTRACT FROM AUTHOR]

This retrospective study investigated whether repetitive exposure to intravenous iodinated contrast media (ICM) affects long-term renal function in patients who undergo curative surgery for early gastric cancer (EGC) collected from the Korean Health Insurance and Review Assessment (HIRA) database. Patients diagnosed with gastric cancer between January 2010 and December 2013 underwent regular computed tomography (CT) scans to monitor for extragastric recurrence. Patients who already had chronic kidney disease (CKD) before cancer diagnosis or had undergone chemotherapy or repeated surgery were excluded. A nested case–control study design was chosen to analyze the effect of repetitive ICM exposure to long-term renal function by comparing patients who developed CKD 2 years after cancer diagnosis and patients who did not. Among 59,971 patients collected according to inclusion and exclusion criteria, 1021 were diagnosed with CKD 2 years after cancer diagnosis. Using 1:5 matching after adjusting for age, sex and date of cancer diagnosis, 5097 control patients were matched to 1021 CKD patients. Conditional logistic regression showed that the number of CTs taken using ICM slightly increased the odds of CKD (odds ratio, 1.080; 95% confidence interval (CI): 1.059, 1.100; P < 0.0001). Thus, the administration of ICM might contribute to chronic renal function impairment. [ABSTRACT FROM AUTHOR]

Objectives: To validate the modified simplified magnetic resonance index of activity (sMARIA) score using DWI on non-contrast magnetic resonance enterography (MRE) to evaluate active inflammation in patients with Crohn's disease (CD), compared to the original sMARIA scoring system, with and without contrast enhancement. Methods: This retrospective study included 275 bowel segments from 55 CD patients who underwent ileocolonoscopy and MRE within a 2-week period. Two blinded radiologists evaluated original sMARIA on both conventional MRE (CE-sMARIA) and non-contrast MRE (T2-sMARIA). Modified sMARIA was then evaluated using non-contrast MRE, replacing ulcerations with DWI grades. Three scoring systems were compared for diagnostic accuracy of active inflammation, correlation with simple endoscopic score (SES)-CD, and interobserver reproducibility. Results: The AUC of modified sMARIA for detecting active inflammation (0.863, 95% confidence interval [0.803–0.923]) was significantly higher than T2-sMARIA (0.827 [0.773–0.881], p = 0.017), and comparable to CE-sMARIA (0.908 [0.857–0.959], p = 0.122). CE-sMARIA, T2-sMARIA, and modified sMARIA all showed moderate correlation with SES-CD (r = 0.795, 0.722, and 0.777, respectively). Interobserver reproducibility of diffusion restriction (κ, 0.686 [0.602–0.770]) was significantly better than ulcers on conventional MRE (κ, 0.382 [0.212–0.552]; p = 0.001) and T2-weighted image (κ, 0.312 [0.034–0.590]; p = 0.012). Conclusions: Modified sMARIA using DWI can improve the diagnostic performance of sMARIA on non-contrast MRE, showing comparable performance to sMARIA using contrast-enhanced MRE. Key Points: • DWI can improve the diagnostic performance of non-contrast magnetic resonance enterography (MRE) for assessing active inflammation in patients with Crohn's disease. • Modified simplified magnetic resonance index of activity (sMARIA) using DWI grades in place of ulcers showed comparable diagnostic performance to sMARIA using conventional MRE with contrast-enhanced sequences. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this retrospective study was to predict circumferential resection margin (CRM) involvement on preoperative CT, and prognostic impact of CRM assessment by CT (ctCRM) in patients with retroperitonealized colon cancer. Methods: This study included patients who underwent resection for ascending or descending colon cancer between July 2010 and February 2013. Positive ctCRM was defined as tumor distance to the retromesenteric plane of ≤ 1 mm. The origin of positive CRM was divided into primary tumor or other tumor components including lymph nodes, tumor deposits, or extramural venous invasions. Logistic regression analysis was performed to identify preoperative factors to predict pathologic CRM (pCRM). A Cox proportional hazards model was used in multivariable analysis to determine the preoperative factors affecting disease-free survival (DFS). Results: A total of 274 patients (mean age, 64.0 years ± 11.0 [standard deviation]; 157 men) with retroperitonealized colon cancer were evaluated. Of 274 patients, 67 patients (24.5%) had positive CRM on surgical pathology. The accuracy of preoperative CT in predicting pCRM was 79.6% (218/274). Among preoperative factors, only CRM assessment on CT was independently associated with pCRM (p < 0.001). Positive ctCRM by primary tumor was an independent factor for DFS (HR, 3.362 [1.714–6.593]) and systemic recurrence (HR, 3.715 [1.787–7.724], but not for local recurrence on multivariable analyses. Conclusions: Preoperative CT can accurately predict pCRM, and positive ctCRM by primary tumor is an independent risk factor for DFS and systemic recurrence, but not for local recurrence in retroperitonealized colon cancer. Key Points: • Preoperative CT can predict pathologic circumferential resection margin (CRM) with approximately 80% of accuracy in patients with retroperitonealized colon cancer. • Positive CRM by a primary tumor on preoperative CT is a poor prognostic factor for disease-free survival and systemic recurrence in patients with retroperitonealized colon cancer. • CRM involvement on CT was not associated with local recurrence in patients with retroperitonealized colon cancer. [ABSTRACT FROM AUTHOR]

Simple Summary: This study describes a new machine-learning-based 28-day mortality prediction model in adult cancer patients admitted to the intensive care unit (ICU). A total of 6900 patients in three patient cohorts were used for the development, internal validation, and external validation, respectively, leading to the generation of a reliable model with high sensitivity and specificity. The CanICU uses nine variables that can be easily obtained in a practical ICU, with the potential benefit of critical care and avoiding unnecessary suffering. Furthermore, this is the largest patient cohort for developing a cancer patient-specific model. CanICU offers improved performance for predicting short- and long-term mortality in critically ill cancer patients admitted to the ICU. CanICU can help physicians determine how to allocate ICU care for patients with cancer according to objective mortality risk. Background: Although cancer patients are increasingly admitted to the intensive care unit (ICU) for cancer- or treatment-related complications, improved mortality prediction remains a big challenge. This study describes a new ML-based mortality prediction model for critically ill cancer patients admitted to ICU. Patients and Methods: We developed CanICU, a machine learning-based 28-day mortality prediction model for adult cancer patients admitted to ICU from Medical Information Mart for Intensive Care (MIMIC) database in the USA (n = 766), Yonsei Cancer Center (YCC, n = 3571), and Samsung Medical Center in Korea (SMC, n = 2563) from 2 January 2008 to 31 December 2017. The accuracy of CanICU was measured using sensitivity, specificity, and area under the receiver operating curve (AUROC). Results: A total of 6900 patients were included, with a 28-day mortality of 10.2%/12.7%/36.6% and a 1-year mortality of 30.0%/36.6%/58.5% in the YCC, SMC, and MIMIC-III cohort. Nine clinical and laboratory factors were used to construct the classifier using a random forest machine-learning algorithm. CanICU had 96% sensitivity/73% specificity with the area under the receiver operating characteristic (AUROC) of 0.94 for 28-day, showing better performance than current prognostic models, including the Acute Physiology and Chronic Health Evaluation (APACHE) or Sequential Organ Failure Assessment (SOFA) score. Application of CanICU in two external data sets across the countries yielded 79–89% sensitivity, 58–59% specificity, and 0.75–0.78 AUROC for 28-day mortality. The CanICU score was also correlated with one-year mortality with 88–93% specificity. Conclusion: CanICU offers improved performance for predicting mortality in critically ill cancer patients admitted to ICU. A user-friendly online implementation is available and should be valuable for better mortality risk stratification to allocate ICU care for cancer patients. [ABSTRACT FROM AUTHOR]

Background: In this post hoc analysis of the PRODIGY study, we aimed to investigate factors associated with survival outcomes and provide evidence for designing optimal perioperative treatment strategies for gastric cancer patients receiving neoadjuvant chemotherapy. Patients and methods: A total of 212 patients in the neoadjuvant chemotherapy group of the PRODIGY study were included as the study population. The prognostic impact of clinicopathologic factors, including the initial radiological clinical stage (cStage) and post-neoadjuvant chemotherapy pathological stage (ypStage), was analyzed. Results: The median age was 58 years. The majority of patients (77.4%) had cStage III disease, and about 10% and 25% had ypStage 0 and I disease, respectively. According to the initial cStage, progression-free survival (PFS) and overall survival (OS) were significantly different (P < 0.01). PFS and OS were also different according to the ypStage (P < 0.01). In multivariate analyses, cStage IIIC disease (vs. cStage II) and ypStage II and III disease (vs. ypStage 0/I) were independent factors for poor survival outcomes. Based on the patterns of PFS and OS according to both cStage and ypStage, three patient groups were defined. These groups showed distinct PFS and OS (P < 0.01) with 5-year PFS rates of 95.7%, 77.9%, and 31.3% and 5-year OS rates of 95.7%, 82.4%, and 42.5%, respectively. Conclusions: Both initial cStage and ypStage were independent factors for survival outcomes of gastric cancer patients treated with neoadjuvant chemotherapy. Efforts should be made to develop optimal peri-operative treatment strategies for patients at different risks according to cStage and ypStage. [ABSTRACT FROM AUTHOR]

Most electronic medical records, such as free-text radiological reports, are unstructured; however, the methodological approaches to analyzing these accumulating unstructured records are limited. This article proposes a deep-transfer-learning-based natural language processing model that analyzes serial magnetic resonance imaging reports of rectal cancer patients and predicts their overall survival. To evaluate the model, a retrospective cohort study of 4,338 rectal cancer patients was conducted. The experimental results revealed that the proposed model utilizing pre-trained clinical linguistic knowledge could predict the overall survival of patients without any structured information and was superior to the carcinoembryonic antigen in predicting survival. The deep-transfer-learning model using free-text radiological reports can predict the survival of patients with rectal cancer, thereby increasing the utility of unstructured medical big data. [ABSTRACT FROM AUTHOR]

Objective: To evaluate diagnostic performance of a radiomics model for classifying hepatic cyst, hemangioma, and metastasis in patients with colorectal cancer (CRC) from portal-phase abdominopelvic CT images. Methods: This retrospective study included 502 CRC patients who underwent contrast-enhanced CT and contrast-enhanced liver MRI between January 2005 and December 2010. Portal-phase CT images of training (n = 386) and validation (n = 116) cohorts were used to develop a radiomics model for differentiating three classes of liver lesions. Among multiple handcrafted features, the feature selection was performed using ReliefF method, and random forest classifiers were used to train the selected features. Diagnostic performance of the developed model was compared with that of four radiologists. A subgroup analysis was conducted based on lesion size. Results: The radiomics model demonstrated significantly lower overall and hemangioma- and metastasis-specific polytomous discrimination index (PDI) (overall, 0.8037; hemangioma-specific, 0.6653; metastasis-specific, 0.8027) than the radiologists (overall, 0.9622–0.9680; hemangioma-specific, 0.9452–0.9630; metastasis-specific, 0.9511–0.9869). For subgroup analysis, the PDI of the radiomics model was different according to the lesion size (< 10 mm, 0.6486; ≥ 10 mm, 0.8264) while that of the radiologists was relatively maintained. For classifying metastasis from benign lesions, the radiomics model showed excellent diagnostic performance, with an accuracy of 84.36% and an AUC of 0.9426. Conclusion: Albeit inferior to the radiologists, the radiomics model achieved substantial diagnostic performance when differentiating hepatic lesions from portal-phase CT images of CRC patients. This model was limited particularly to classifying hemangiomas and subcentimeter lesions. Key Points: • Albeit inferior to the radiologists, the radiomics model could differentiate cyst, hemangioma, and metastasis with substantial diagnostic performance using portal-phase CT images of colorectal cancer patients. • The radiomics model demonstrated limitations especially in classifying hemangiomas and subcentimeter liver lesions. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the usefulness of contrast-enhanced abdominal computed tomography (CECT) to predict clinically significant anastomotic leakage (CSAL) in patients who received colorectal cancer surgery with diverting ileostomy. Methods: In this retrospective cohort study, patients who underwent colorectal cancer surgery with diverting ileostomy from January 2014 to May 2018 and postoperative CECT were included. The performance of significant CECT features, identified using multivariable logistic regression, to predict CSAL was calculated. In subgroup analysis, the areas under the receiver operating characteristic curve (AUROCs) were compared between CECT and water-soluble contrast enema (WSCE) using DeLong's method. Results: Of 325 patients (median age, 58 years; 213 men), CECT was routinely performed to evaluate cancer status in 307 (94.5%), and CSAL was observed in 28 (8.6%). After multivariable adjustment, anastomotic mural defect (odds ratio [OR] 5.24; 95% confidence interval [CI] 1.77–15.51; p = 0.003), perianastomotic air (OR 7.28; 95% CI 1.82–29.17; p = 0.007) and ischemic colitis (OR 3.30; 95% CI 1.13–9.61; p = 0.029) were significantly associated with CSAL. The sensitivity, specificity, accuracy, and positive and negative predictive values of significant CECT features were 60.7%, 88.2%, 85.9%, 32.7%, and 96.0%, respectively. In subgroup analysis of 144 patients, the AUROC using significant CECT features (optimal sensitivity/specificity, 50.0%/90.4%) was comparable to that using WSCE (optimal sensitivity/specificity, 12.5%/97.8%) to predict CSAL (0.704 vs. 0.552, p = 0.085). Conclusion: CECT performed after colorectal cancer surgery may be useful to assess anastomotic integrity before ileostomy closure, especially to negatively predict CSAL. In the presence of anastomotic mural defect, perianastomotic air, or ischemic colitis, WSCE may be recommended to exclude CSAL. [ABSTRACT FROM AUTHOR]

Purpose: We propose a deep learning method that classifies focal liver lesions (FLLs) into cysts, hemangiomas, and metastases from portal phase abdominal CT images. We propose a synthetic data augmentation process to alleviate the class imbalance and the Lesion INformation Augmented (LINA) patch to improve the learning efficiency. Methods: A dataset of 502 portal phase CT scans of 1,290 FLLs was used. First, to alleviate the class imbalance and to diversify the training data patterns, we suggest synthetic training data augmentation using DCGAN‐based lesion mask synthesis and pix2pix‐based mask‐to‐image translation. Second, to improve the learning efficiency of convolutional neural networks (CNNs) for the small lesions, we propose a novel type of input patch termed the LINA patch to emphasize the lesion texture information while also maintaining the lesion boundary information in the patches. Third, we construct a multi‐scale CNN through a model ensemble of ResNet‐18 CNNs trained on LINA patches of various mini‐patch sizes. Results: The experiments demonstrate that (a) synthetic data augmentation method shows characteristics different but complementary to those in conventional real data augmentation in augmenting data distributions, (b) the proposed LINA patches improve classification performance compared to those by existing types of CNN input patches due to the enhanced texture and boundary information in the small lesions, and (c) through an ensemble of LINA patch‐trained CNNs with different mini‐patch sizes, the multi‐scale CNN further improves overall classification performance. As a result, the proposed method achieved an accuracy of 87.30%, showing improvements of 10.81%p and 15.0%p compared to the conventional image patch‐trained CNN and texture feature‐trained SVM, respectively. Conclusions: The proposed synthetic data augmentation method shows promising results in improving the data diversity and class imbalance, and the proposed LINA patches enhance the learning efficiency compared to the existing input image patches. [ABSTRACT FROM AUTHOR]

Post contrast-acute kidney injury (PC-AKI) is defined as the deterioration of renal function after administration of iodinated contrast media. HMGB1 is known to play an important role in the development of acute kidney injury. The purpose of this study was to investigate the association between HMGB1 and PC-AKI and the protective effect of glycyrrhizin, a direct inhibitor of HMGB1, in rats. Rats were divided into three groups: control, PC-AKI and PC-AKI with glycyrrhizin. Oxidative stress was measured with MDA levels and H2DCFDA fluorescence intensity. The mRNA expressions of pro-inflammatory cytokines (IL-1α, IL-1β, IL-6 and TNF-α) and kidney injury markers (KIM-1, NGAL and IL-18) were assessed using RT-PCR and ELISA in kidney tissue. In addition, the serum and intracellular protein levels of HMGB1were analyzed with the enzyme-linked immunosorbent assay (ELISA) and western blotting. Histologic changes were assessed with H&E staining using the transmission electron microscope (TEM). Moreover, serum creatinine (SCr), blood urea nitrogen (BUN) and lactate dehydrogenase (LDH) levels were assessed. Oxidative stress, pro-inflammatory cytokines, kidney injury markers and LDH were significantly higher in PC-AKI compared to the controls, but were lower in PC-AKI with glycyrrhizin. Intracellular and serum HMGB1 levels significantly increased after contrast media exposure, whereas they markedly decreased after glycyrrhizin pretreatment. SCr and BUN also decreased in PC-AKI with glycyrrhizin compared to PC-AKI. In PC-AKI, we could frequently observe tubular dilatation with H&E staining and cytoplasmic vacuoles on TEM, whereas these findings were attenuated in PC-AKI with glycyrrhizin. Our findings indicate that HMGB1 plays an important role in the development of PC-AKI and that glycyrrhizin has a protective effect against renal injury and dysfunction by inhibiting HMGB1 and reducing oxidative stress. [ABSTRACT FROM AUTHOR]

Objectives: To compare the performance of current guidelines applicable to the diagnosis of hepatocellular carcinomas (HCCs) using gadoxetic acid–enhanced magnetic resonance imaging (MRI). Methods: Two hundred and forty-one hepatic lesions (149 HCCs, six other malignancies, 86 benign lesions) in 177 patients at risk of HCC without a history of previous treatment for hepatic malignancy in a tertiary center were retrospectively reviewed. Either histopathology results or long-term (> 24 months) follow-up images were used as a standard of reference. All lesions were categorized according to the Liver Imaging Reporting and Data System (LI-RADS), European Association for the Study of the Liver (EASL), Asian Pacific Association for the Study of the Liver (APASL), and Korean Liver Cancer Study Group-National Cancer Center (KLCSG-NCC) guidelines. The sensitivity and specificity thereof were assessed using a generalized estimation equation. Results: For gadoxetic acid–enhanced MRI, LI-RADS (95%, 95% confidence interval [CI] 88–98) and EASL (94%, 95% CI 86–97) yielded the highest specificity, while EASL yielded the lowest sensitivity (54% [95% CI 46–62]). APASL yielded the highest sensitivity (91% [95% CI 86–95]) with the lowest specificity (78% [95% CI 69–86]). KLCSG-NCC showed balanced sensitivity (85% [79–90]) and specificity (88% [95% CI 80–93]). Differences were more prominent in small nodules between 1 and 2 cm. Conclusion: The diagnostic performance of current guidelines for HCC on gadoxetic acid–enhanced MRI was significantly different, and a potential inverse association between sensitivity and specificity was observed. Key Points: • EASL and LI-RADS yielded the highest specificity with the lowest sensitivity, whereas APASL yielded the highest sensitivity with the lowest specificity. • Differences in the diagnostic performances of guidelines were prominent in small nodules between 1 and 2 cm. • Additional evaluation of CT findings improved the diagnostic sensitivity and accuracy of EASL and LI-RADS. Although doing so decreased specificity, it remained above 89–90%. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the performance of a radiomic signature-based model for predicting recurrence-free survival (RFS) of locally advanced gastric cancer (LAGC) using preoperative contrast-enhanced CT. This retrospective study included a training cohort (349 patients) and an external validation cohort (61 patients) who underwent curative resection for LAGC in 2010 without neoadjuvant therapies. Available preoperative clinical factors, including conventional CT staging and endoscopic data, and 438 radiomic features from the preoperative CT were obtained. To predict RFS, a radiomic model was developed using penalized Cox regression with the least absolute shrinkage and selection operator with ten-fold cross-validation. Internal and external validations were performed using a bootstrapping method. With the final 410 patients (58.2 ± 13.0 years-old; 268 female), the radiomic model consisted of seven selected features. In both of the internal and the external validation, the integrated area under the receiver operating characteristic curve values of both the radiomic model (0.714, P < 0.001 [internal validation]; 0.652, P = 0.010 [external validation]) and the merged model (0.719, P < 0.001; 0.651, P = 0.014) were significantly higher than those of the clinical model (0.616; 0.594). The radiomics-based model on preoperative CT images may improve RFS prediction and high-risk stratification in the preoperative setting of LAGC. [ABSTRACT FROM AUTHOR]

Background: Although the current standard preoperative chemoradiotherapy (PCRT) for stage II/III rectal cancer decreases the risk of local recurrence, it does not improve survival and increases the likelihood of preoperative overtreatment, especially in patients without circumferential resection margin (CRM) involvement. Methods: Stage II/III rectal cancer without CRM involvement and lateral lymph node metastasis was radiologically defined by preoperative magnetic resonance imaging (MRI). Patients who received PCRT followed by total mesorectal excision (TME) (PCRT group) and upfront surgery (US) with TME (US group) between 2010 and 2016 were analyzed. We derived cohorts of PCRT group versus US group using propensity-score matching for stage, age, and distance from the anal verge. Three-year relapse-free survival rate, disease-free survival (DFS), and overall survival (OS) were compared between the two groups. Results: A total of 202 patients were analyzed after propensity score matching. There were no differences in baseline characteristics. The median follow-up duration was 62 months (interquartile range, 46–87). There was no difference in the 3-year disease-free survival rate between the PCRT and US groups (83 vs. 88%, respectively; p=0.326). Likewise, there was no significant difference in the 3-year OS (89 vs. 91%, respectively; p=0.466). The 3-year locoregional recurrence rates (3 vs. 2% with US, p=0.667) and distant metastasis rates (16 vs. 11%, p=0.428) were not significantly different between the two groups. Time to completion of curative treatment was significantly shorter in the US group (132 days) than in the PCRT group (225 days) (p<0.001). Conclusion: Using MRI-guided selection for better risk stratification, US without neoadjuvant therapy can be considered in early stage patients with good prognosis. PCRT may not be required for all stage II/III rectal cancer patients, especially for the MRI-proven intermediate-risk group (cT1-2/N1, cT3N0) without CRM involvement and lateral lymph node metastasis. Further prospective studies are warranted. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to evaluate the diagnostic performance of the Liver Imaging Reporting and Data System (LI-RADS) in patients with both chronic liver disease and a history of extrahepatic malignancy. Materials and methods: This retrospective study included 59 hepatocellular carcinomas (HCCs) and 45 metastases pathologically confirmed between 2008 and 2017 in 104 patients with chronic liver disease (cirrhosis or chronic hepatitis B) and a history of extrahepatic malignancy. Two radiologists blinded to the final diagnosis independently reviewed MRI (95 patients) or CT (9 patients) images, and their consensus data were used to calculate the diagnostic performance of LI-RADS categories. Serum tumor markers, tumor multiplicity, and suspected metastatic lymph nodes were also evaluated. Results: The sensitivity, specificity, and accuracy of LR-5 for diagnosing HCC were 69% (95% confidence intervals [CI] 56–81), 98% (95% CI 88–99), and 82% (95% CI 73–89), respectively, and those of LR-M for diagnosing metastasis were 89% (95% CI 76–96), 88% (95% CI 77–95), and 88% (95% CI 81–94), respectively. Elevation of serum carcinoembryonic antigen (P = 0.01) or carbohydrate antigen 19–9 levels (P = 0.02) and tumor multiplicity (P = 0.004) were more frequently observed in metastasis than in HCC. Three of four metastases categorized as LR-4 or LR-5 were smaller than 2 cm. Conclusions: The LI-RADS provides high specificity (98%) for differentiating HCC from metastases in patients with both chronic liver disease and a history of extrahepatic malignancy. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the diagnostic performance of LR-M criteria for differentiating hepatocellular carcinoma, intrahepatic mass-forming cholangiocarcinoma, and combined hepatocellular-cholangiocarcinoma and to compare the imaging features of each type. Methods: In this retrospective study, 110 patients were surgically diagnosed with cholangiocarcinoma (n = 67) and combined hepatocellular-cholangiocarcinoma (n = 43) at a single tertiary hospital between 2013 and 2018. Among them, those with risk factors were enrolled (16 cholangiocarcinomas and 33 combined hepatocellular-cholangiocarcinomas). Forty-nine other patients with size-matched hepatocellular carcinoma were selected as a control group. Two independent readers evaluated the imaging findings of the preoperative MRIs based on LI-RADS version 2018 and assigned an LI-RADS category. The diagnostic performance of the LR-M criteria for diagnosing cholangiocarcinoma or combined hepatocellular-cholangiocarcinoma was evaluated, and the imaging features were compared. The imaging findings of the tumors in patients without risk factors (51 cholangiocarcinomas and 10 combined hepatocellular-cholangiocarcinomas) were evaluated for subgroup analysis. Results: In the non-hepatocellular carcinoma group, 33 patients were categorized into LR-M and 14 patients into LR-5 (67.3% and 28.6%, respectively), while 5 patients with hepatocellular carcinoma were categorized into LR-M and 38 patients into LR-5 (10.2% and 77.6%, respectively). Sensitivity and specificity of the LR-M criteria were 67.3% and 89.8%, respectively. When more than two LR-M features were present, cholangiocarcinoma or combined hepatocellular-cholangiocarcinoma were suggested with a specificity of 95.9%. Conclusion: The diagnostic performance of the LR-M criteria is acceptable with moderate sensitivity and high specificity for both cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma. Imaging findings of primary hepatic carcinomas should be understood as a spectrum. [ABSTRACT FROM AUTHOR]

Purpose: To compare gadolinium retention in the abdominal organs after administration of gadoxetic acid disodium, a liver‐specific contrast agent, compared to gadodiamide and gadobutrol. Methods: Three types of gadolinium‐based contrast agents (GBCAs) were administered to rats. A single (gadodiamide and gadobutrol, 0.1 mmol/kg; gadoxetic acid disodium, 0.025 mmol/kg) or double label‐recommended dose was intravenously administered once (Group 1), a single dose was administered 4 times (Group 2) and a single dose with or without a chelating agent (intraperitoneal injection immediately after each GBCA administration) was administered (Group 3). Rats were sacrificed after 1, 4, and 12 weeks and gadolinium concentrations in the liver, spleen, kidney, muscle, and bone were measured by inductively coupled plasma mass spectrometry. P values less than 0.05 were considered statistically significant. Results: More gadolinium was retained with a double dose compared to a single dose, but there was no observed significant difference in gadolinium retention after a double dose compared to a single dose (P >.05). Gadodiamide was retained the most in all tissues followed by gadobutrol and gadoxetic acid disodium. Residual gadolinium was significantly less at 4 weeks compared to 1 week (P <.05), but no further decrease was observed after 4 weeks (P >.05). The presence of the chelating agent did not significantly decrease the concentration of residual gadolinium (P >.05). Conclusion: Gadolinium was retained the least in abdominal organs after gadoxetic acid disodium was administered and most of the residual gadolinium was excreted 4 weeks after GBCA administration when a label‐recommended dose was administered. A commercially available chelation therapy agent could not reduce gadolinium retention. [ABSTRACT FROM AUTHOR]

Objectives: Contrast-induced acute kidney injury (CI-AKI) is one of the leading causes of new-onset renal failure in hospitalized patients. Statin has been evaluated for its protective effect against CI-AKI but rarely in patients receiving intravenous (IV) administrations of iodine-based contrast media for enhanced computed tomography (CT).Methods: In total, 12,371 patients who underwent contrast-enhanced abdominopelvic CT were retrospectively reviewed and stratified into statin users and statin nonusers. Subgroup analyses comparing high-intensity statins with low- to moderate-intensity statins were conducted within statin users and similar comparisons were performed within statin users stratified based on baseline eGFR.Results: Overall, CI-AKI events did not occur less in statin users compared with non-statin users (p = 0.342). Within statin users, CI-AKI events did not decrease in high-intensity statin users compared with low- to moderate-intensity statin users (p = 0.355). Moreover, no significant difference in CI-AKI events was found between high-intensity statin users and low- to moderate-intensity statin users even after stratifying the patients with baseline eGFR.Conclusions: Collectively, statin was not significantly associated with the risk of CI-AKI events in patients undergoing contrast-enhanced abdominopelvic CT and high-intensity statins did not show significant association with CI-AKI over low- to moderate-intensity statins in the subgroup analysis.Key Points: • Statin is not associated with risk of CI-AKI events in patients undergoing intravenous administration of contrast-enhanced CT. • CI-AKI incidence among high-intensity statin users was not significantly different from that of low- to moderate-intensity statin users. [ABSTRACT FROM AUTHOR]

Deep learning has recently attracted widespread interest as a means of reducing noise in low-dose CT (LDCT) images. Deep convolutional neural networks (CNNs) are typically trained to transfer high-quality image features of normal-dose CT (NDCT) images to LDCT images. However, existing deep learning approaches for denoising LDCT images often overlook the statistical property of CT images. In this paper, we propose an approach to statistical image restoration for LDCT using deep learning. We introduce a loss function to incorporate the noise property in image domain derived from the noise statistics in sinogram domain. In order to capture the spatially-varying statistics of CT images, we increase the receptive fields of the neural network to cover full-size CT slices. In addition, the proposed network utilizes $z$ -directional correlation by taking multiple consecutive CT slices as input. For performance evaluation, the proposed networks are trained and validated with a public dataset consisting of LDCT-NDCT image pairs. We also perform a retrospective study by testing the networks with clinical LDCT images. The experimental results show that the denoising networks successfully reduce the noise level and restore the image details without adding artifacts. This study demonstrates that the statistical deep learning approach can restore the image quality of LDCT without loss of anatomical information. [ABSTRACT FROM AUTHOR]

Background: Preoperative chemoradiotherapy (PCRT) followed by surgery and adjuvant chemotherapy is the current standard treatment for stage II/III rectal cancer. However, radiotherapy in the pelvic area is commonly associated with complications such as anastomotic leakage, sexual dysfunction, and fecal incontinence. Recently, the MERCURY study showed that preoperative high-resolution magnetic resonance imaging (MRI) helped to selectively avoid PCRT. It remains unclear whether PCRT is necessary in patients who can achieve a negative circumferential resection margin (CRM) with surgery alone and in patients with cT1-2N1 or cT3N0 without CRM involvement and lateral lymph node metastasis. This study aims to evaluate the efficacy of upfront radical surgery with total mesorectal excision (TME) followed by adjuvant chemotherapy with folinic acid (or leucovorin), fluorouracil, and oxaliplatin (FOLFOX) versus the current standard treatment in patients with surgically resectable, locally advanced rectal cancer.Methods: This study, named TME-FOLFOX, is a prospective, open-label, multicenter, phase II randomized trial. Patients with locally advanced rectal cancer will be randomized to receive PCRT followed by TME and adjuvant chemotherapy (arm A) or upfront radical surgery with TME followed by adjuvant FOLFOX chemotherapy (arm B). Clinical stage II/III rectal cancer without CRM involvement and lateral lymph node metastasis will be defined using preoperative MRI. The primary endpoint is 3-year disease-free survival (DFS). Secondary endpoints include 5-year DFS, local recurrence rate, systemic recurrence rate, cost-effectiveness, and overall survival. We hypothesized that our experimental group (arm B) will have a 3-year DFS of 75% and a non-inferiority margin of 15%.Discussion: Identifying whether patients require PCRT is one of the critical issues in locally advanced rectal cancer. This study aims to elucidate whether PCRT may not be required for all patients with stage II/III rectal cancer, especially for the MRI-based intermediate-risk group (with cT1-2N1 or cT3N0) without CRM involvement and lateral lymph node metastasis. If the findings indicate that our proposed treatment, which omits PCRT, is non-inferior to the standard treatment, then patients may avoid unnecessary radiation-related toxicity, have a shorter treatment duration, and save on medical costs.Trial Registration: ClinicalTrials.gov, NCT02167321. Registered on 19 June 2014. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the impact of mesorectal fat area (MFA) on oncologic outcomes in patients with mid-to-lower rectal cancer who received curative-intent surgery.Methods: Patients with mid-to-lower rectal cancer who underwent preoperative abdominopelvic computed tomography (CT) and curative-intent surgery in 2011 were divided into two groups by tumour recurrence (group A) or no recurrence (group B) during a 5-year follow-up. Visceral fat area (VFA) and MFA were measured on preoperative CT and cutoff values were calculated using the Youden index. Univariate and multivariate regression analyses including BMI, VFA, and MFA were performed to investigate meaningful prognostic biomarkers. The Kaplan-Meier method with log-rank testing was used to validate prognostic biomarkers.Results: Group A contained 42 patients and group B had 155 patients. Cutoff values were 25 kg/m2 for BMI, 130 cm2 for VFA, and 10 cm2 for MFA using the Youden index. On multivariate Cox regression analysis, MFA (odds ratio [OR] = 0.426, p = 0.010), TNM stage (p = 0.027), and perioperative complication grade (p = 0.028) were significantly different between groups. BMI and VFA did not show significant differences. By the Kaplan-Meier method with log-rank testing, disease-free survival (DFS) was significantly longer in patients with MFA ≥10 cm2 compared to patients with MFA <10 cm2 (p = 0.021), with no significant difference in overall survival (OS).Conclusions: MFA was an independent biomarker for predicting DFS in patients who underwent curative-intent surgery for mid-to-lower rectal cancer.Key Points: • Mesorectal fat area is associated with the prognosis of rectal cancer patients. • Mesorectal fat area can be calculated easily in pre-operative CT scan. • Predicting prognosis of the cancer patient before operation is important. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the diagnostic value of signal intensity (SI)-selected volumetry findings in T2-weighted magnetic resonance imaging (MRI) as a potential biomarker for predicting pathological complete response (pCR) to preoperative chemoradiotherapy (CRT) in patients with rectal cancer.Methods: Forty consecutive patients with pCR after preoperative CRT were compared with 80 age- and sex-matched non-pCR patients in a case-control study. SI-selected tumor volume was measured on post-CRT T2-weighted MRI, which included voxels of the treated tumor exceeding the SI (obturator internus muscle SI + [ischiorectal fossa fat SI - obturator internus muscle SI] × 0.2). Three blinded readers independently rated five-point pCR confidence scores and compared the diagnostic outcome with SI-selected volumetry findings. The SI-selected volumetry protocol was validated in 30 additional rectal cancer patients.Results: The area under the receiver-operating characteristic curve (AUC) of SI-selected volumetry for pCR prediction was 0.831, with an optimal cutoff value of 649.6 mm3 (sensitivity 0.850, specificity 0.725). The AUC of the SI-selected tumor volume was significantly greater than the pooled AUC of readers (0.707, p < 0.001). At this cutoff, the validation trial yielded an accuracy of 0.87.Conclusion: SI-selected volumetry in post-CRT T2-weighted MRI can help predict pCR after preoperative CRT in patients with rectal cancer.Key Points: • Fibrosis and viable tumor MRI signal intensities (SIs) are difficult to distinguish.• T2 SI-selected volumetry yields high diagnostic performance for assessing pathological complete response.• T2 SI-selected volumetry is significantly more accurate than readers and non-SI-selected volumetry.• Post-chemoradiation therapy T2-weighted MRI SI-selected volumetry facilitates prediction of pathological complete response. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel vessel tracking method, called active vessel tracking (AVT). The proposed method retains the major advantages that most 2D segmentation methods have demonstrated for 3D tracking while overcoming the drawbacks of previous 3D vessel tracking methods. Under the assumption that the vessel is cylindrical, thereby making its cross-section elliptical, the AVT finds a plane perpendicular to the vessel axis while tracking the vessel along its length. Also, We propose a method for vessel branch detection to automatically track complete vascular networks from a single starting point, whereas the previously proposed solutions have usually been limited in handling vessel bifurcations precisely on 3D or have required considerable user interaction. Our results show that the method is robust and accurate in both synthetic and clinical cases. In an experiment on synthetic data sets, the proposed method achieved a tracking accuracy of 96.1±0.5, detecting 99.1% of the branches. In an experiment on abdominal CTA data sets, it achieved a tracking accuracy of 98.4±0.5 for six target vessels, detecting 98.3% of the branches. These results show that the proposed method can outperform previous methods for vessel tracking. [ABSTRACT FROM AUTHOR]

Background: With advances in gastric cancer chemotherapy, conversion surgery has drawn attention as a new strategy to improve the outcome of stage IV disease. We investigated the efficacy of conversion surgery following chemotherapy for patients with stage IV gastric cancer.Methods: We retrospectively reviewed clinico-pathologic variables and oncologic outcomes for 101 patients with stage IV gastric cancer who were treated with systemic chemotherapy followed by gastrectomy with intension of curative resection from January 2005 to December 2012.Results: In terms of the best response from palliative chemotherapy, complete or partial response were observed in 65 patients (64.4%) in overall. Complete response of metastatic site were observed in 72 (71.3%) and 66 (65.3%) patients as best and pre-operative response, respectively. The overall complete macroscopic resection, rate was 56.4%. Eleven patients (10.9%) received combined metastasectomy. There was no postoperative surgery-related mortality for 1 month. The median overall survival time was 26.0 months. Multivariable analysis identified complete macroscopic resection, chemotherapy response (complete response/partial response) of metastatic sites, and change in CEA level as independent prognostic factors contributing to overall survival.Conclusions: Patients with stage IV gastric cancer who exhibit a good clinical response to chemotherapy might obtain greater survival benefit from gastrectomy following chemotherapy compared with patients who exhibit a poor response to chemotherapy. Prospective, randomized trials are required to determine the best strategy for combining initial chemotherapy with subsequent gastrectomy. [ABSTRACT FROM AUTHOR]

Background: There is increasing interest in the influence of body composition on oncological outcomes. We evaluated the role of skeletal muscle and fat among patients with gastric cancer (GC) who underwent gastrectomy with or without adjuvant chemotherapy, as well as those changes’ associations with survival outcomes.Methods: The present study evaluated 136 patients with GC who were enrolled in the CLASSIC Trial at Yonsei Cancer Center. Baseline body compositions including skeletal muscle area, Hounsfield units (HU), visceral fat area, and subcutaneous fat area were measured by preoperative computed tomography (CT). CT before and after the gastrectomy were used to determine the 6-month relative changes in body composition parameters. Continuous variables were dichotomized according to the best cutoff values by Contal and O’Quigley method.Results: Seventy-three patients (53.7%) underwent surgery alone, and 63 patients (46.3%) underwent surgery followed by adjuvant chemotherapy. The baseline body composition parameters were not associated with disease-free survival (DFS) or overall survival (OS). Except for the HU, the marked loss of muscle, visceral fat, or subcutaneous fat significantly predicted shorter DFS and OS. Patients with a marked loss in at least one significant body composition parameter had significantly shorter DFS (hazard ratio 2.9, 95% confidence interval 1.7-4.8, P < 0.001) and OS (hazard ratio 2.9, 95% confidence interval 1.7-5.0, P < 0.001).Conclusions: Marked loss in body composition parameters significantly predicted shorter DFS and OS among patients with GC who underwent gastrectomy. Postoperative nutrition and active healthcare interventions could improve the prognosis of these GC patients. [ABSTRACT FROM AUTHOR]

Background: Preoperative therapy has gained wide interest in advanced gastric cancer patients due to its potential advantages of improved disease control. Selection of high risk patients based on preoperative staging is crucial to choose the candidates for neoadjuvant therapy. Methods: Our institutional review board approved this retrospective study and waived the requirement for patient consent. We searched 394 advanced gastric cancer patients (pT2-4) who underwent curative resection in 2010 without neoadjuvant therapies. Two abdominal radiologists independently reviewed the preoperative CT including tumor depth on CT (CT-tumor depth), which was categorized as follows: intramural, minimal extramural(<1mm), spiculated extramural(≥1mm) and nodular extramural infiltration. The impact of clinicoradiologic factors on disease recurrence and disease free survival (DFS) was evaluated. Recursive partitioning analysis was performed to suggest prediction models for recurrence. Results: Of total 394 patients, 86 patients (21.8%) experienced recurrence. Spiculated (≥1mm) and nodular extramural tumor infiltration and CT size of 5-10cm were independent predictors of disease recurrence and significantly associated with worse DFS. Lymph node involvement on CT was not significantly associated with patient outcome. Among patients with same pT4a stage, the recurrence rate rises and DFS gets worse as the extramural tumor infiltration progresses (P < 0.001). The prediction model for recurrence revealed that size and CT-tumor depth were the two major discriminating factors. Conclusion: CT-tumor depth and size could be used as independent predictors for prognosis. Preoperative CT can be used for prognostic stratification to select high risk patients for whom neoadjuvant therapies might be considered. [ABSTRACT FROM AUTHOR]

Purpose: Patterns of locoregional rectal cancer recurrences following total mesorectal excision (TME) were analyzed to define the irradiation volume, especially the lateral pelvic lymph node (LPLN).Materials and methods: Of 1243 patients who underwent TME without pelvic radiotherapy between 2005 and 2012, the data of 826 patients with rectal adenocarcinoma without distant metastases were analyzed for relapse patterns, categorized as distant and locoregional (anastomosis, mesorectum, presacral area, and LPLNs) failure.Results: The median follow-up was 61.8 months. The 5-year local recurrence-free, distant metastasis-free, overall survival rates were 88, 82, and 89%, respectively. Relapse occurred in 108 (13%) patients: 90 (11%) had distant and 28 (3%) had locoregional failure. Eight patients had LPLN recurrence: the 2 recurrences from upper rectal cancers occurred near the bifurcation of the common iliac artery into the external and internal iliac vessels; the 6 mid-lower rectal cancers had 16 recurrences near the internal iliac and obturator arteries—five occurred anterior to the obturator artery and posterior to the external iliac artery, superior to the femoral head. LPLN recurrence was associated with pN2 stage, perinodal extension, and lymphovascular invasion.Conclusion: The LPLN component of pre- or postoperative irradiation volumes could potentially be optimized based on our mapping data. However, since patients in our institution at high risk for relapse received either preoperative or postoperative chemoradiation, further analyses are needed to confirm our findings. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the optimal magnetic resonance (MR) imaging protocol in pregnant women suspected of having acute appendicitis.Materials and Methods: One hundred and forty-six pregnant women with suspected appendicitis were included. MR images were reviewed by two radiologists in three separate sessions. In session 1, only axial single-shot turbo spin echo (SSH-TSE) T2-weighted images (WI) were included with other routine sequences. In sessions 2 and 3, coronal and sagittal T2WI were sequentially added. The visibility of the appendix and diagnostic confidence of appendicitis were evaluated in each session using a 5-point grading scale. If diseases other than appendicitis were suspected, specific diagnosis with a 5-point confidence scale was recorded. Diagnostic performance for appendicitis and other diseases were evaluated.Results: Twenty-five patients (17.1%) were diagnosed with appendicitis. Among the patients with normal appendix, 28 were diagnosed with other disease. Diagnostic performance including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve values for diagnosing appendicitis and other diseases showed no significant difference among sets for both reviewers (p>0.05).Conclusion: Diagnostic performance of MR in pregnant patients with suspected appendicitis can be preserved with omission of sagittal or both coronal and sagittal SSH-T2WI.Key Points: • Diagnostic performance of appendicitis is preserved with omission of sagittal/coronal T2WIs. • Diagnosis of other disease may be sufficient with axial T2WIs only. • Careful serial omission of sagittal and coronal T2WIs can be considered. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the diagnostic value of the T1 bright appendix sign for the diagnosis of acute appendicitis in pregnant women.Material and Methods: This retrospective study included 125 pregnant women with suspected appendicitis who underwent magnetic resonance (MR) imaging. The T1 bright appendix sign was defined as a high intensity signal filling more than half length of the appendix on T1-weighted imaging. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the T1 bright appendix sign for normal appendix identification were calculated in all patients and in those with borderline-sized appendices (6-7 mm).Results: The T1 bright appendix sign was seen in 51% of patients with normal appendices, but only in 4.5% of patients with acute appendicitis. The overall sensitivity, specificity, PPV, and NPV of the T1 bright appendix sign for normal appendix diagnosis were 44.9%, 95.5%, 97.6%, and 30.0%, respectively. All four patients with borderline sized appendix with appendicitis showed negative T1 bright appendix sign.Conclusion: The T1 bright appendix sign is a specific finding for the diagnosis of a normal appendix in pregnant women with suspected acute appendicitis.Key Points: • Magnetic resonance imaging is increasingly used in emergency settings. • Acute appendicitis is the most common cause of acute abdomen. • Magnetic resonance imaging is widely used in pregnant population. • T1 bright appendix sign can be a specific sign representing normal appendix. [ABSTRACT FROM AUTHOR]

Purpose: Hepatic malignancies can easily develop resistance to antiangiogenic therapy, but the underlying mechanism remains poorly understood. This study explores whether antiangiogenic therapy influences the tumor vascular network and/or the vessels feeding the hepatic tumor. Methods: Mice implanted with Lewis lung carcinoma (LLC) cells were subcutaneously injected 3 times (once every other day starting 1 week after LLC implantation) with either an antiangiogenic agent [vascular endothelial growth factor (VEGF)-T rap] or control agent (bovine serum albumin) at a dose of 25 mg/kg before performing angiography. Hepatic arteriography and portography were performed using a vascular cast method with vascular latex. Results: Arteriography of the control-treated LLC-implanted mice showed marked staining of the mass with a prominent feeding artery, suggesting that the tumor is supplied by arterial perfusion. No significant staining was observed on portography. By contrast, 33% (n = 3/9) of the LLC-implanted mice treated with the antiangiogenic agent VEGF-Trap showed intratumoral staining during portography, indicating that these tumors received perfusion via the portal vein. Conclusion: Antiangiogenic treatment can induce rearrangement of the hepatic tumor vascular network to establish communication with the portal vein. This implies that hepatic tumors can develop resistance to antiangiogenic therapy by maintaining perfusion through portal venous perfusion. [ABSTRACT FROM AUTHOR]

Purpose: Rectal cancer patients achieving pCR are known to have an excellent prognosis, yet no widely accepted consensus on risk stratification and post-operative management (e.g., adjuvant therapy) has been established. This study aimed to identify magnetic resonance imaging (MRI) high-risk factors for tumor relapse in pathological complete remission (pCR) achieved by rectal cancer patients who have undergone neoadjuvant concurrent chemoradiation therapy (CRT) and curative resection. Materials and Methods: We analyzed 88 (male/female = 55/33, median age, 59.5 years [range 34–78]) pCR-proven rectal cancer patients who had undergone pre-CRT MRI, CRT, post-CRT MRI and curative surgery between July 2005 and December 2012. Patients were observed for post-operative tumor relapse. We analyzed the pre/post-CRT MRIs for parameters including mrT stage, mesorectal fascia (mrMRF) status, tumor volume, tumor regression grade (mrTRG), nodal status (mrN), and extramural vessel invasion (mrEMVI). We performed univariate analysis and Kaplan-Meier survival analysis. Results: Post-operative tumor relapse occurred in seven patients (8.0%, n = 7/88) between 5.7 and 50.7 (median 16.8) months. No significant relevance was observed between tumor volume, volume reduction rate, mrTRG, mrT, or mrN status. Meanwhile, positive mrMRF (Ppre-CRT = 0.018, Ppre/post-CRT = 0.006) and mrEMVI (Ppre-CRT = 0.026, Ppre-/post-CRT = 0.008) were associated with higher incidence of post-operative tumor relapse. Kaplan-Meier survival analysis revealed a higher risk of tumor relapse in patients with positive mrMRF (Ppre-CRT = 0.029, Ppre-/post-CRT = 0.009) or mrEMVI (Ppre-CRT = 0.024, Ppre-/post-CRT = 0.003). Conclusion: Positive mrMRF and mrEMVI status was associated with a higher risk of post-operative tumor relapse of pCR achieved by rectal cancer patients, and therefore, can be applied for risk stratification and to individualize treatment plans. [ABSTRACT FROM AUTHOR]

Objective: To investigate the feasibility of dual-energy CT for contrast media (CM) reduction in the diagnosis of hypervascular and hypovascular focal liver lesions (FLL). Subjects and Methods: The Institutional Animal Care and Use Committee approved this study. VX2 tumors were implanted in two different segments of the liver in 13 rabbits. After 2 weeks, two phase contrast enhanced CT scans including the arterial phase (AP) and portal-venous phase (PVP) were performed three times with 24-hour intervals with three different concentrations of iodine, 300 (I300), 150 (I150) and 75 mg I/mL (I75). The mean HU and standard deviation (SD) were measured in the liver, the hypervascular portion of the VX2 tumor which represented hypervascular tumors, and the central necrotic area of the VX2 tumor which represented hypovascular tumors in 140kVp images with I300 as a reference standard and in monoenergetic images (between 40keV and 140keV) with I150 and I75. The contrast-to-noise ratio (CNR) for FLLs and the ratio of the CNRs (CNRratio) between monoenergetic image sets with I150 and I75, and the reference standard were calculated. Results: For hypervascular lesions, the CNRratio was not statistically different from 1.0 between 40keV and 70keV images with I150, whereas the CNRratio was significantly lower than 1.0 in all keV images with I75. For hypovascular lesions, the CNRratio was similar to or higher than 1.0 between 40keV and 80keV with I150 and between 40keV and 70keV with I75. Conclusions: With dual-energy CT, the total amount of CM might be halved in the diagnosis of hypervascular FLLs and reduced to one-fourth in the diagnosis of hypovascular FLLs, while still preserving CNRs. [ABSTRACT FROM AUTHOR]

Purpose: Human hepatocellular carcinoma (HCC) has unique vascular features, which require selective imaging of hepatic arterial perfusion and portal venous perfusion with vascular catheterization for sufficient evaluation. Unlike in humans, vessels in mice are too small to catheterize, and the importance of separately imaging the feeding vessels of tumors is frequently overlooked in hepatic tumor models. The purpose of this study was to perform selective latex angiography in several mouse liver tumor models and assess their suitability. Materials and Methods: In several ectopic (Lewis lung carcinoma, B16/F10 melanoma cell lines) and spontaneous liver tumor (Albumin-Cre/MST1fl/fl/MST2fl/fl, Albumin-Cre/WW45fl/fl, and H-ras12V genetically modified mouse) models, the heart left ventricle and/or main portal vein of mice was punctured, and latex dye was infused to achieve selective latex arteriography and/or portography. Results: H-ras12V transgenic mice (a HCC and hepatic adenoma model) developed multiple liver nodules that displayed three different perfusion patterns (portal venous or hepatic artery perfusion predominant, mixed perfusion), indicating intra-tumoral vascular heterogeneity. Selective latex angiography revealed that the Lewis lung carcinoma implant model and the Albumin-Cre/WW45fl/fl model reproduced conventional angiography findings of human HCC. Specifically, these mice developed tumors with abundant feeding arteries but no portal venous perfusion. Conclusion: Different hepatic tumor models showed different tumor vessel characteristics that influence the suitability of the model and that should be considered when designing translational experiments. Selective latex angiography applied to certain mouse tumor models (both ectopic and spontaneous) closely simulated typical characteristics of human HCC vascular imaging. [ABSTRACT FROM AUTHOR]

Objectives: To determine whether magnetic resonance imaging (MRI)-detected extramural vascular invasion (EMVI) could predict synchronous distant metastases in rectal cancer. Methods: Patients who underwent rectal MRI between July 2011 and December 2012 were screened. This study included 447 patients with pathologically confirmed rectal adenocarcinoma who had undergone MRI without previous treatment. Distant metastases were recorded at the initial work-up and over a 6-month follow-up. Univariate/multivariate logistic regression models were used to determine the risk of metastasis. The diagnostic performance was calculated using pathologic lymphovascular invasion (LVI) as a gold standard. Results: Among 447 patients, 79 patients (17.7 %) were confirmed to have distant metastases. Three MRI features are significantly associated with a high risk of distant metastasis: positive EMVI (odds ratio 3.02), high T stage (odds ratio 2.10) and positive regional lymph node metastasis (odds ratio 6.01). EMVI in a large vessel (≥3 mm) had a higher risk for metastasis than EMVI in a small vessel (<3 mm). Sensitivity, specificity and accuracy of MRI-detected EMVI were 28.2 %, 94.0 % and 80.3 %, respectively. Conclusions: MRI-detected EMVI is an independent risk factor for synchronous metastasis in rectal cancer. EMVI in large vessels is a stronger risk factor for distant metastasis than EMVI in small vessels. Key points: • EMVI, LN metastasis and T staging on MRI are risk factors for metastasis. • EMVI in large vessels has greater risk for metastasis than in small vessels. • Regional LN metastasis on MRI has highest risk for predicting metastasis. • MR findings could be helpful for selecting patients at high risk for metastasis. [ABSTRACT FROM AUTHOR]

Purpose To compare the breathhold, navigator-triggered, and free-breathing techniques in diffusion-weighted magnetic resonance imaging (MRI) for the evaluation of focal liver lesions on a 3.0T system. Materials and Methods Fifty-two patients (36 men, 16 women; mean age, 56.4 years) with focal liver lesions underwent breathhold, navigator-triggered, and free-breathing diffusion-weighted imaging (DWI) of the liver on a 3.0 Tesla (T) system. All sequences were performed with b values of 50 and 800 s/mm2 and identical parameters except for signal averages (two for navigator-triggered, one for breathhold, and four for free-breathing) and repetition time (3389 ms for navigator-triggered, 1500 ms for breathhold, and 4400 ms for free-breathing). A total of 74 lesions (50 malignant, 24 benign) were evaluated. The signal-to-noise ratios (SNR) of the liver and lesions, contrast-to-noise ratios (CNR) of each lesion, and ADC values of the liver and lesions were compared for each DWI sequence. The detection sensitivity and characterization accuracy were also compared. Results The SNRs of the liver and lesions were significantly lower for breathhold DWI than for non-breathhold DWI (navigator-triggered and free-breathing DWI) for all b values. The CNRs of the lesions were also significantly lower for breathhold DWI than for non-breathhold DWI. The ADC values of the liver and focal lesions measured using the three DWI techniques were not significantly different and showed good correlation. For lesion detection and characterization, there were no significant differences between breathhold and non-breathhold DWI. Conclusion Both breathhold and non-breathhold DWI are comparable for the detection or characterization of focal liver lesions at 3.0T; however, non-breathhold DWI provides higher SNR and CNR than breathhold DWI. In addition, although free-breathing and navigator-triggered DWI sequences show similar performance for 3.0T liver imaging, free-breathing DWI is more time efficient than navigator-triggered DWI. J. Magn. Reson. Imaging 2013;38:109-118. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Purpose: To compare diffusion-weighted imaging (DWI) and magnetic resonance (MR) volumetry for predicting treatment outcomes of locally advanced rectal cancers with preoperative chemoradiotherapy (CRT). Materials and Methods: This prospective study was approved by our Institutional Review Board. Thirty-four patients underwent three MR examinations: pre-CRT (before CRT), early CRT (2 weeks after CRT initiation), and post-CRT (before surgery). The tumor apparent diffusion coefficient (ADC), ADC increase rate, and volume reduction rate were compared between responders and nonresponders using three reference standards: downstaging, modified Response Evaluation Criteria in Solid Tumors (mRECIST), and tumor regression grade (TRG). For DWI and volumetry, differences between responders and nonresponders were assessed by receiver operating characteristic analysis. Results: The median early tumor volume reduction rate of responders, subgrouped by downstaging and mRECIST (47.97% and 53.97%, respectively), was significantly higher than that of nonresponders (20.94% and 20.36%; P = 0.0024 and 0.0001, respectively), but there were no significant differences in pre-CRT ADC and early ADC increase rate using all references. When using the downstaging and mRECIST, the diagnostic performance of early tumor volume reduction rate (Az = 0.81 and 0.94, respectively) was higher than that of pre-CRT ADC (Az = 0.55 and 0.62; P = 0.033 and 0.007) and early ADC increase rate (Az = 0.58 and 0.64; P = 0.055 and 0.01) for predicting the treatment outcome. For TRG, there were no significant differences between DWI and volumetry. Conclusion: Early tumor volume reduction rate at the second week after CRT initiation may be a better indicator than DWI based on the mean ADC measurements for predicting CRT treatment outcome. J. Magn. Reson. Imaging 2011;. © 2011 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Objective: To retrospectively assess the value of adding gadolinium-enhanced dynamic imaging to standard ununenhanced magnetic resonance imaging (MRI) for characterising hypoattenuating hepatic lesions that are too small to characterise with multi-detector computed tomography (MDCT).Methods: Informed consent was waved, and institutional review board approval was obtained. Three hundred and forty-six small (≤ 2 cm) lesions (63 metastatic, 283 benign) in 183 patients with underlying carcinoma who underwent hepatic MRI after CT were retrospectively analysed. Two radiologists independently reviewed images and diagnoses were graded on an ordinal scale from 1 (definitely benign) to 5 (definitely malignant). Receiver operating characteristic analysis was used. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were also determined.Results: The areas under the curve of the ununenhanced images alone and with dynamic images were 0.837 and 0.850 for reader 1 (p = 0.616) and 0.771 and 0.783 for reader 2 (p = 0.700). Descriptive statistical values demonstrated sensitivities of 76% and 80%, specificities of 93% and 95%, PPVs of 69% and 79%, NPVs of 95% and 95% and accuracies of 90% and 92%, respectively.Conclusion: The value of adding three-phase contrast-enhanced MRI to unenhanced imaging did not reach statistical significance for characterising small hypoattenuating hepatic lesions on MDCT. [ABSTRACT FROM AUTHOR]

Objective: To determine whether intravenous administration of gadoxetic acid disodium (Gd-EOB-DTPA) affects lesion conspicuity and apparent diffusion coefficient (ADCs) in diffusion-weighted imaging (DWI) for hepatic magnetic resonance imaging (MRI) at 3.0 T.Methods: Thirty-four patients with 50 focal hepatic lesions (18 hepatocellular carcinomas, 12 metastases, 1 cholangiocarcinoma, 7 haemangiomas, 12 cysts) underwent DWI at 3.0 T before and after administration of Gd-EOB-DTPA. Non-breath-hold DWI was performed with b values of 0, 200, 400 and 800 s/mm(2). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of each lesion, and ADCs of the liver and lesion were calculated for unenhanced and enhanced images. Statistical differences between unenhanced and enhanced data were assessed.Results: SNRs and ADCs of the liver on enhanced images were significantly lower than on unenhanced images. On DW images at b = 200 s/mm(2), CNRs of malignant and overall lesions were significantly higher on enhanced than on unenhanced images. CNRs of focal lesions tended to be higher, especially in malignant lesions, on DW images at b = 0 and 400 s/mm(2), but without reaching statistical significance. ADCs of focal hepatic lesions were not significantly different before and after administration of contrast agent.Conclusion: DWI after Gd-EOB-DTPA administration can be used as a substitute for unenhanced DWI at 3.0 T without compromising CNR and ADC of focal hepatic lesions. [ABSTRACT FROM AUTHOR]

Purpose: To assess the diagnostic performance of gadobenate dimeglumine-enhanced 3D gradient echo (3D-GRE) magnetic resonance imaging (MRI) for the detection of hepatic hypovascular metastases. Materials and Methods: We retrospectively analyzed the initial radiologic reports of MRI of 41 patients with suspected hepatic metastases. Seventy-nine metastatic lesions were confirmed by histopathology or intraoperative ultrasound (IOUS). The sensitivity and positive predictive values for the diagnosis of hepatic metastasis were determined among each MRI set (hepatobiliary phase, precontrast images, dynamic imaging). The diagnostic performance of dynamic image set and combined dynamic and hepatobiliary image set was also evaluated by two radiologists using alternative free response receiver operating characteristic (ROC) analysis. Results: The overall detection rate and positive predictive value of MR were 96.2% (76/79) and 96.2% (76/79), respectively. Images obtained with hepatobiliary phase 3D-GRE showed a significantly better detection rate compared to those with precontrast sequences or dynamic imaging ( P = 0.008 and 0.016, respectively). Regarding lesions 1 cm or smaller, the detection rate was 90.3% (28/31). Each reader showed a higher Az value of the combined hepatobiliary image set than those of the dynamic image set. Conclusion: 3D-GRE MRI using a hepatobiliary contrast agent is an accurate tool in the detection of hepatic hypovascular metastases and improves detection rate compared with precontrast and dynamic imaging. J. Magn. Reson. Imaging 2010;31:571-578. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

We examined 20 prediagnostic CTs from 16 patients for whom the diagnosis of pancreatic cancer was delayed until full diagnostic CT was performed. Three radiologists independently reviewed the prediagnostic CTs along with 50 CTs of control subjects, including patients without pancreatic disease (n = 38) or with chronic pancreatitis without calcification visible on CT (n = 12). The reviewers recorded the presence of biliary or pancreatic ductal dilation, interruption of the pancreatic duct, distal parenchymal atrophy, contour abnormality and focal hypoattenuation. Frequency, sensitivity and specificity of the significant findings were calculated. Logistic regression analysis was performed. Findings indicative of pancreatic cancer were seen on 85% (17/20) of the prediagnostic CTs. Patients with pancreatic cancer were significantly (p < 0.05) more likely to show focal hypoattenuation, pancreatic duct dilation, interruption of the pancreatic duct, and distal parenchymal atrophy, with sensitivities and specificities of 75%/84%, 50%/78%, 45%/82% and 45%/96%, respectively. Focal hypoattenuation and distal parenchymal atrophy were the independent predictors of pancreatic cancer with odds ratios of 20.92 and 11.22, respectively. In conclusion, focal hypoattenuation and pancreatic duct dilation with or without interruption, especially when accompanied by distal parenchymal atrophy, were the most useful findings for avoiding delayed diagnosis of pancreatic cancer. [ABSTRACT FROM AUTHOR]

Gastric submucosal tumors (SMTs) consist of various lesions arising from the deep layers of the stomach. Gastrointestinal stromal tumors (GISTs) are undoubtedly the commonest malignant SMTs of the stomach, and therefore the attitude towards the general diagnostic approach for GISTs defines the extended diagnostic plan for SMTs. Two recent consensus meetings were assembled concerning the classification and therapeutic plans for GISTs. These meetings shed light upon the need for the modification of the current role of imaging modalities, including endoscopic ultrasound (EUS) and computed tomography (CT). According to the revised concepts of GISTs, the most important and plausible current role of imaging for the diagnostic approach of gastric SMTs is to differentiate GISTs from other gastric SMTs. This review discusses the newly established diagnostic role of radiology according to the revised classification of GISTs and provides the differential diagnoses based on EUS and CT findings. [ABSTRACT FROM AUTHOR]