Early post-treatment MRI predicts long-term hepatocellular carcinoma response to radiation segmentectomy.

OBJECTIVES: Radiation segmentectomy using yttrium-90 plays an emerging role in the management of early-stage HCC. However, the value of early post-treatment MRI for response assessment is uncertain. We assessed the value of response criteria obtained early after radiation segmentectomy in predicting long-term response in patients with HCC. MATERIALS AND METHODS: Patients with HCC who underwent contrast-enhanced MRI before, early, and 12 months after radiation segmentectomy were included in this retrospective single-center study. Three independent radiologists reviewed images at baseline and 1st follow-up after radiation segmentectomy and assessed lesion-based response according to mRECIST, LI-RADS treatment response algorithm (TRA), and image subtraction. The endpoint was response at 12 months based on consensus readout of two separate radiologists. Diagnostic accuracy for predicting complete response (CR) at 12 months based on the 1st post-treatment MRI was calculated. RESULTS: Eighty patients (M/F 60/20, mean age 67.7 years) with 80 HCCs were assessed (median size baseline, 1.8 cm [IQR, 1.4-2.9 cm]). At 12 months, 74 patients were classified as CR (92.5%), 5 as partial response (6.3%), and 1 as progressive disease (1.2%). Diagnostic accuracy for predicting CR was fair to good for all readers with excellent positive predictive value (PPV): mRECIST (range between 3 readers, accuracy: 0.763-0.825, PPV: 0.966-1), LI-RADS TRA (accuracy: 0.700-0.825, PPV: 0.983-1), and subtraction (accuracy: 0.775-0.825, PPV: 0.967-1), with no difference in accuracy between criteria (p range 0.053 to > 0.9). CONCLUSION: mRECIST, LI-RADS TRA, and subtraction obtained on early post-treatment MRI show similar performance for predicting long-term response in patients with HCC treated with radiation segmentectomy. CLINICAL RELEVANCE STATEMENT: Response assessment extracted from early post-treatment MRI after radiation segmentectomy predicts complete response in patients with HCC with high PPV (≥ 0.96). KEY POINTS: • Early post-treatment response assessment on MRI predicts response in patients with HCC treated with radiation segmentectomy with fair to good accuracy and excellent positive predictive value. • There was no difference in diagnostic accuracy between mRECIST, LI-RADS, and subtraction for predicting HCC response to radiation segmentectomy.

Benign and Malignant Ovarian Teratomas: Multimodality Imaging Findings With Histopathologic Correlation.

ABSTRACT: The purpose of this article is to provide a comprehensive review of the imaging findings along with histopathologic correlation of mature (benign) teratomas and malignant ovarian teratomas, which include both immature teratomas and malignant degeneration of mature teratomas. The radiologist's ability to provide an accurate diagnosis plays an essential role in guiding the interdisciplinary care of patients with malignant teratomas and improving their outcomes.

HCC screening with ultrasound: assessment of quality using ultrasound LI-RADS score.

PURPOSE: To describe ultrasound (US) quality for hepatocellular carcinoma (HCC) screening/surveillance using the US LI-RADS scoring system, and to assess predictive factors of worse US quality scores. METHODS: This retrospective study included adult patients (n = 470; M/F 264/206, median age 59y) at risk for HCC that underwent US for HCC screening/surveillance. US examinations were independently reviewed by 2 radiologists that assigned a visualization score (A: no/minimal, B: moderate, C: severe limitation) and US diagnostic category (US LI-RADS 1: negative, US LI-RADS 2: subthreshold, US LI-RADS 3: positive) to each study. A generalized linear mixed model was used to assess the predictive factors of worse visualization score using OR (odds ratio) statistics. Simple Kappa coefficient (K) assessed inter-reader agreement. RESULTS: For readers 1 and 2, 295/320 (62.8%/68.1%) cases were scored A, 153/134 (32.6%/28.5%) were scored B, and 22/16 (4.6%/3.4%) were scored C, respectively. There was moderate inter-reader agreement for US LI-RADS visualization score (K = 0.478) and 100% concordance for US diagnostic category (K = 1), with 30 (6.4%) cases scored as positive (US LI-RADS 3). Cirrhosis and obesity were significant independent predictors of worse visualization scores (B/C) (cirrhosis: OR 10.4 confidence intervals: [4.25-25.48], p < 0.001; obesity: OR 3.61 [2.11-6.20], p < 0.001). Of the 30 lesions scored as US LI-RADS 3, 9 were characterized as probable or definite HCC on confirmatory CT/MRI, yielding a PPV of 30% (9/30) and a false-positive rate of 70% (21/30). CONCLUSION: Moderate to severe limitations in quality of US performed for HCC screening/surveillance was observed in approximately one-third of patients. Patients with cirrhosis and/or elevated BMI have poorer quality US studies and may benefit from other screening modalities such as CT or MRI.

Intrahepatic flow diversion prior to segmental Yttrium-90 radioembolization for challenging tumor vasculature.

Background: Hepatic tumors with complex vascular supply or poor relative perfusion are prone to decreased rates of objective response. This is compounded in the setting of Yttrium-90 (Y90) transarterial radioembolization (TARE), which is minimally embolic and flow-dependent, relying on high threshold dose for complete response. Objective: We describe our experience with intrahepatic flow diversion (FD) prior to TARE of hepatocellular carcinoma (HCC) with challenging vascular supply. Materials and methods: Between April 2014 and January 2020, 886 cases of coinciding MAA or TARE and bland embolization or temporary occlusion were identified. Intraprocedural embolizations performed for more routine purposes were excluded. FD was performed by bland embolization or temporary occlusion of vessels supplying non-malignant parenchyma in cases where flow was not preferential to target tumor. Lesion characteristics, vascular supply, treatment approach, angiography, and adverse events (AEs) were reviewed. Radiographic response was assessed using mRECIST criteria. Results: 22 cases of FD of focal HCC were identified. Embolics included calibrated microspheres (n â€‹= â€‹11), microcoils (n â€‹= â€‹4), gelfoam (n â€‹= â€‹3), temporary balloon occlusion (n â€‹= â€‹2) and temporary deployment of a microvascular plug (n â€‹= â€‹1). Post-treatment SPECT-CT dosimetry coverage was concordant with target lesions in all cases. Mean follow-up was 16.7 months (1.4-45 â€‹mos). Tumor-specific response per mRECIST was 41% complete response, 50% objective response, and 59% disease control rate. No major adverse events or grade 3/4 hepatotoxicity were reported. Conclusion: Our findings suggest that FD prior to TARE is safe and potentially effective in treating HCC with complex vascular supply or poor tumor perfusion.

Cross-Sectional Imaging Findings of Atypical Liver Malignancies and Diagnostic Pitfalls: Emphasis on Computed Tomography, and Magnetic Resonance Imaging.

Atypical liver malignancies can either be uncommon presentations of commonly encountered liver malignancies or rare tumors infrequently seen in clinical practice and often pose a challenge in diagnostic imaging interpretation. These lesions tend to be highly variable in their imaging appearance and are less well discussed in the literature. Commonly, an inter-disciplinary approach incorporating clinical information, imaging data, and histopathology is needed to reach an accurate diagnosis. The diagnostic radiologist's knowledge of such liver malignancies can aid the clinical team in reaching the correct diagnosis and enabling appropriate management. In this article, we review certain technical considerations and focus on the unusual appearances of common primary and secondary malignant liver lesions, uncommon malignant liver lesions, with emphasis on computed tomography (CT) and magnetic resonance imaging (MRI).

Luminal Narrowing Alone Allows an Accurate Diagnosis of Crohn's Disease Small Bowel Strictures at Cross-Sectional Imaging.

BACKGROUND AND AIMS: Current consensus recommendations define small bowel strictures [SBS] in Crohn's disease [CD] on imaging as luminal narrowing with unequivocal upstream bowel dilation. The aim of this study was to [1] evaluate the performance of cross-sectional imaging for SBS diagnosis in CD using luminal narrowing with upstream SB dilation and luminal narrowing with or without upstream dilation, and [2] compare the diagnostic performance of computed tomography [CT] and magnetic resonance enterography [MRE] for SBS diagnosis. METHODS: In total, 111 CD patients [81 with pathologically confirmed SBS, 30 controls] who underwent CT and/or MRE were assessed. Two radiologists [R1, R2] blinded to pathology findings independently assessed the presence of luminal narrowing and upstream SB dilation. Statistical analysis was performed for [1] luminal narrowing with or without SB upstream dilation ['possible SBS'], and [2] luminal narrowing with upstream SB dilation ≥3 cm ['definite SBS']. RESULTS: Sensitivity for detecting SBS was significantly higher using 'possible SBS' [R1, 82.1%; R2, 77.9%] compared to 'definite SBS' [R1, 62.1%; R2, 65.3%; p < 0.0001] with equivalent specificity [R1, 96.7%; R2, 93.3%; p > 0.9]. Using the criterion 'possible SBS', sensitivity/specificity were equivalent between CT [R1, 87.3%/93.3%; R2, 83.6%/86.7%] and MRE [R1, 75.0%/100%; R2: 70.0%/100%]. Using the criterion 'definite SBS', CT showed significantly higher sensitivity [78.2%] compared to MRE [40.0%] for R1 but not R2 with similar specificities [CT, 86.7-93.3%; MRE, 100%]. CONCLUSION: SBS can be diagnosed using luminal narrowing alone without the need for upstream dilation. CT and MRE show similar diagnostic performance for SBS diagnosis using luminal narrowing with or without upstream dilation.

Response assessment of hepatocellular carcinoma treated with yttrium-90 radioembolization: inter-reader variability, comparison with 3D quantitative approach, and role in the prediction of clinical outcomes.

OBJECTIVES: To assess the inter-reader variability in response assessment for HCC treated with radioembolization (TARE) compared with 3D quantitative criteria (qEASL); and to evaluate their role in prediction of pathological necrosis and clinical outcomes. MATERIALS AND METHODS: 57 patients with 77 HCCs who underwent TARE were included. Five radiologists recorded multiple imaging features and assigned mRECIST/LIRADS Treatment Response (TR) categories on post-treatment MRI at 4-6 weeks and 6-9 months after TARE. qEASL categories were assigned by a separate reader. Inter-reader variability between LIRADS TR/mRECIST/qEASL were evaluated and hazards regression was used in predicting clinical outcomes. RESULTS: Inter-reader agreement was fair for mRECIST (K = 0.43 and 0.34 at first and second follow-up respectively); moderate for LIRADS TR (K = 0.48 and 0.53 at first and second follow-up respectively). Inter-criterion agreement was moderate to substantial (r = 0.41-0.65 and r = 0.54-0.60 at first and second follow-up) for mRECIST-qEASL. LIRADS TR correlated well with qEASL for all readers at both follow-ups (K = 0.45-0.78; K = 0.39-0.77 for first and second follow-up). qEASL was the most accurate in predicting Tumor-Free Survival (TFS) on first (HR 2.23 [1.44-3.46], p < 0.001) and second (HR 1.69 [1.15-2.48], p = 0.008) follow-up. LIRADS TR was the most accurate in predicting histopathological necrosis (8 patients underwent liver transplantation and 1 patient underwent tumor resection during the period of the study). CONCLUSIONS: HCC response assessment following TARE is challenging, resulting in poor to moderate inter-reader agreement for mRECIST, and moderate inter-reader agreement for LIRADS TR response assessment criteria. qEASL outperformed mRECIST criteria for early identification of responders and predicting TFS, suggesting an advantage in volumetric tumor response assessment. LIRADS TR outperformed other criteria in predicting pathological necrosis.

Lung base CT findings in COVID-19 adult patients presenting with acute abdominal complaints: case series from a major New York City health system.

OBJECTIVE: To describe demographic, clinical, and lung base CT findings in COVID-19 patients presenting with abdominal complaints. METHODS: In this retrospective study, 76 COVID-19 patients who underwent abdominal CT for abdominal complaints from March 1 to April 15, 2020, in a large urban multihospital Health System were included. Those with positive abdominal CT findings (n = 14) were then excluded, with 62 patients undergoing final analysis (30M/32F; median age 63 years, interquartile range (IQR) 52-75 years, range 30-90 years). Demographic and clinical data were extracted. CT lung base assessment was performed by a cardiothoracic radiologist. Data were compared between discharged and hospitalised patients using Wilcoxon or Fisher's exact tests. RESULTS: The majority of the population was non-elderly (56.4%, < 65 years) and most (81%) had underlying health conditions. Nineteen percent were discharged and 81% were hospitalised. The most frequent abdominal symptoms were pain (83.9%) and nausea/vomiting/anorexia (46.8%). Lung base CT findings included ground-glass opacities (95.2%) in a multifocal (95.2%) and peripheral (66.1%) distribution. Elevated laboratory values (when available) included C-reactive protein (CRP) (97.3%), D-dimer (79.4%), and ferritin (68.8% of males and 81.8% of females). Older age (p = 0.045), hypertension (p = 0.019), and lower haemoglobin in women (p = 0.042) were more frequent in hospitalised patients. There was no difference in lung base CT findings between discharged and hospitalised patients (p > 0.165). CONCLUSIONS: COVID-19 patients can present with abdominal symptoms, especially in non-elderly patients with underlying health conditions. Lung base findings on abdominal CT are consistent with published reports. Radiologists should be aware of atypical presentations of COVID-19. KEY POINTS: • COVID-19 infected patients can present with acute abdominal symptoms, especially in non-elderly patients with underlying health conditions, and may frequently require hospitalisation (81%). • There was no difference in lung base CT findings between patients who were discharged and those who were hospitalised. • Lung base CT findings included multifocal and peripheral ground-glass opacities, consistent with published reports.

Outcomes assessment in intrahepatic cholangiocarcinoma using qualitative and quantitative imaging features.

BACKGROUND: To assess the performance of imaging features, including radiomics texture features, in predicting histopathologic tumor grade, AJCC stage, and outcomes [time to recurrence (TTR) and overall survival (OS)] in patients with intrahepatic cholangiocarcinoma (ICC). METHODS: Seventy-three patients (26 M/47F, mean age 63y) with pre-operative imaging (CT, n = 37; MRI, n = 21; CT and MRI, n = 15] within 6 months of resection were included in this retrospective study. Qualitative imaging traits were assessed by 2 observers. A 3rd observer measured tumor apparent diffusion coefficient (ADC), enhancement ratios (ERs), and Haralick texture features. Blood biomarkers and imaging features were compared with histopathology (tumor grade and AJCC stage) and outcomes (TTR and OS) using log-rank, generalized Wilcoxon, Cox proportional hazards regression, and Fisher exact tests. RESULTS: Median TTR and OS were 53.9 and 79.7 months. ICC recurred in 64.4% (47/73) of patients and 46.6% (34/73) of patients died. There was fair accuracy for some qualitative imaging features in the prediction of worse tumor grade (maximal AUC of 0.68 for biliary obstruction on MRI, p = 0.032, observer 1) and higher AJCC stage (maximal AUC of 0.73 for biliary obstruction on CT, p = 0.002, observer 2; and AUC of 0.73 for vascular involvement on MRI, p = 0.01, observer 2). Cox proportional hazards regression analysis showed that CA 19-9 [hazard ratio (HR) 2.44/95% confidence interval (CI) 1.31-4.57/p = 0.005)] and tumor size on imaging (HR 1.13/95% CI 1.04-1.22/p = 0.003) were significant predictors of TTR, while CA 19-9 (HR 4.08/95% CI 1.75-9.56, p = 0.001) and presence of metastatic lymph nodes at histopathology (HR 2.86/95% CI 1.35-6.07/p = 0.006) were significant predictors of OS. On multivariable analysis, satellite lesions on CT (HR 2.79/95%CI 1.01-7.15/p = 0.032, observer 2), vascular involvement on MRI (HR 0.10/95% CI 0.01-0.85/p = 0.032, observer 1), and texture feature MRI variance (HR 0.55/95% CI 0.31-0.97, p = 0.040) predicted TTR once adjusted for the independent predictors CA 19-9 and tumor size on imaging. Several qualitative and quantitative features demonstrated associations with TTR, OS, and AJCC stage at univariable analysis (range: HR 0.35-19; p < 0.001-0.045), however none were predictive of OS at multivariable analysis when adjusted for CA 19-9 and metastatic lymph nodes (p > 0.088). CONCLUSIONS: There was reasonable accuracy in predicting tumor grade and higher AJCC stage in ICC utilizing certain qualitative and quantitative imaging traits. Serum CA 19-9, tumor size, presence of metastatic lymph nodes, and qualitative imaging traits of satellite lesions and vascular involvement are predictors of patient outcomes, along with a promising predictive ability of certain quantitative texture features.

Three visual working memory representations simultaneously control attention.

How many items can we store in visual working memory while simultaneously conducting a visual search? Previous research has proposed that during concurrent visual search, only one visual working memory representation can be activated to directly influence attention. This previous research suggests that other visual working memory representations are "accessory items", which have little direct influence on attention. However, recent findings provided evidence that not one, but two visual working memory representations can capture attention and interfere with concurrent visual search. We successfully replicate these findings, and further test whether the capacity of visual working memory during visual search extends to not two, but three representations that influence attention directly. We find evidence that three visual working memory representations can simultaneously control attention.

Review of chest CT manifestations of COVID-19 infection.

Coronavirus disease-19 (COVID-19) is a viral pandemic that started in China and has rapidly expanded worldwide. Typical clinical manifestations include fever, cough and dyspnea after an incubation period of 2-14 days. The diagnosis is based on RT-PCR test through a nasopharyngeal swab. Because of the pulmonary tropism of the virus, pneumonia is often encountered in symptomatic patients. Here, we review the pertinent clinical findings and the current published data describing chest CT findings in COVID-19 pneumonia, the diagnostic performance of CT for diagnosis, including differential diagnosis, as well the evolving role of imaging in this disease.

MRI radiomics features predict immuno-oncological characteristics of hepatocellular carcinoma.

OBJECTIVE: To assess the value of qualitative and quantitative MRI radiomics features for noninvasive prediction of immuno-oncologic characteristics and outcomes of hepatocellular carcinoma (HCC). METHODS: This retrospective, IRB-approved study included 48 patients with HCC (M/F 35/13, mean age 60y) who underwent hepatic resection or transplant within 4 months of abdominal MRI. Qualitative imaging traits, quantitative nontexture related and texture features were assessed in index lesions on contrast-enhanced T1-weighted and diffusion-weighted images. The association of imaging features with immunoprofiling and genomics features was assessed using binary logistic regression and correlation analyses. Binary logistic regression analysis was also employed to analyse the association of radiomics, histopathologic and genomics features with radiological early recurrence of HCC at 12 months. RESULTS: Qualitative (r = - 0.41-0.40, p < 0.042) and quantitative (r = - 0.52-0.45, p < 0.049) radiomics features correlated with immunohistochemical cell type markers for T-cells (CD3), macrophages (CD68) and endothelial cells (CD31). Radiomics features also correlated with expression of immunotherapy targets PD-L1 at protein level (r = 0.41-0.47, p < 0.029) as well as PD1 and CTLA4 at mRNA expression level (r = - 0.48-0.47, p < 0.037). Finally, radiomics features, including tumour size, showed significant diagnostic performance for assessment of early HCC recurrence (AUC 0.76-0.80, p < 0.043), while immunoprofiling and genomic features did not (p = 0.098-0929). CONCLUSIONS: MRI radiomics features may serve as noninvasive predictors of HCC immuno-oncological characteristics and tumour recurrence and may aid in treatment stratification of HCC patients. These results need prospective validation. KEY POINTS: • MRI radiomics features showed significant associations with immunophenotyping and genomics characteristics of hepatocellular carcinoma. • Radiomics features, including tumour size, showed significant associations with early hepatocellular carcinoma recurrence after resection.

Lower-Limb Factors Associated with Balance and Falls in Older Adults: A Systematic Review and Clinical Synthesis.

BACKGROUND: Despite sufficient evidence to suggest that lower-limb-related factors may contribute to fall risk in older adults, lower-limb and footwear influences on fall risk have not been systematically summarized for readers and clinicians. The purpose of this study was to systematically review and synethesize the literature related to lower-limb, foot, and footwear factors that may increase the risk of falling among community-dwelling older adults. METHODS: We searched PubMed, Embase, PsycINFO, CINAHL, Web of Science, Cochrane Library, and AgeLine. To describe the trajectory toward increasing risk of falls, we examined those articles that linked age-related changes in the lower limb or footwear to prospective falls or linked them to evidenced-based fall risk factors, such as gait and balance impairment. RESULTS: This systematic review consisted of 81 articles that met the review criteria, and the results reflect a narrative review of the appraised literature for eight pathways of lower-limb-related influences on fall risk in older adults. Six of the eight pathways support a direct link to fall risk. Two other pathways link to the intermediate factors but lack studies that provide evidence of a direct link. CONCLUSIONS: This review provides strong guidance to advance understanding and assist with managing the link between lower-limb factors and falls in older adults. Due to the lack of literature in specific areas, some recommendations were based on observational studies and should be applied with caution until further research can be completed.

Dual Modality Radiation With External Beam Radiation Therapy and Transarterial Radioembolization for Hepatocellular Carcinoma With Gross Vascular Invasion.

OBJECTIVES: Patients with hepatocellular carcinoma (HCC) and gross vascular invasion (GVI) have poor outcomes with systemic therapy such as sorafenib. Both external beam radiation therapy (EBRT) and transarterial radioembolization (TARE) have been utilized for this patient population. We sought to compare outcomes using dual modality radiation (EBRT+TARE) versus EBRT alone in patients with HCC and GVI. MATERIALS AND METHODS: Between 2011 and 2017, 45 patients with HCC and GVI were treated with EBRT±TARE at our institution. Progression-free survival (PFS) and overall survival (OS) were assessed and compared using Kaplan-Meier method and log-rank test. Univariable and multivariable Cox proportional hazards regression was used to assess the impact of the variables stage, etiology of cirrhosis, Child-Pugh (CP) score, and Karnofsky Performance Score (KPS) on PFS and OS. RESULTS: Patient characteristics were well-balanced except for KPS (80 vs. 90) and CP score. Median OS for patients receiving EBRT+TARE was 263 days (95% confidence interval [CI]: 167, -) versus 193 days (95% CI: 51, 262) for EBRT alone (P=0.049). However, this did not hold up on MVA. When EBRT and TARE were delivered within 2 months as planned (n=12), median PFS was 218 days (95% CI: 44, -) for dual modality radiation versus 63 days (95% CI: 38, 137) for EBRT alone (P=0.048). When EBRT and TARE were delivered within 6 months, the difference in PFS was no longer seen (P=NS), because some patients received TARE as a salvage therapy. CONCLUSIONS: Dual modality radiation with EBRT and TARE may be associated with improved OS in patients with HCC and GVI. Dual modality radiation may be associated with improved PFS in patients with HCC and GVI compared with EBRT alone when EBRT and TARE are delivered within 2 months of each other as part of a planned dual modality treatment strategy. However, since this is a retrospective study with inherent selection bias, these findings need further validation in a prospective clinical trial for patients with HCC and GVI.

Feasibility and reproducibility of liver surface nodularity quantification for the assessment of liver cirrhosis using CT and MRI.

PURPOSE: To assess intra-observer, inter-observer and inter-modality (CT vs. MRI) reproducibility of liver surface nodularity (LSN) scores measured with software used for detection of liver fibrosis. METHODS: This IRB-approved retrospective study included patients with both abdominal CT and MRI within 6 months of histopathologic sampling. Two independent observers used post-processing software to quantify LSN scores on axial non-contrast CT (NCT), axial contrast-enhanced CT (CECT), axial T2-weighted (T2W) HASTE, and axial and coronal post-gadoxetic acid T1-weighted (T1W) images obtained during the hepatobiliary phase (HBP). Ten slices were used to acquire the LSN scores. Intra-observer, inter-observer, and inter-modality (CT vs. MRI) reproducibility were assessed with intraclass correlation coefficient (ICC) and coefficients of variability (CV). Accuracy for detection of cirrhosis was evaluated for each technique. RESULTS: 26 patients (M/F 19/7, mean age 57 years), including 7 with cirrhosis (26.9%), were assessed. Technical failure occurred with NCT (1/23, 4.3%) and T2 HASTE (8/28, 28.6%). Intra-observer reproducibility was excellent for NCT, CECT, axial and coronal T1W HBP [ICC ≥ 0.92, CV ≤ 8%]. Inter-observer reproducibility was also excellent for NCT and CECT (ICC ≥ 0.95, CV ≤ 7.3%) and for coronal T1W HBP (ICC = 0.84, CV = 5.6%). There was fair to moderate agreement between CT and MRI (ICC 0.20-0.44). There were significant differences in mean LSN scores between non-cirrhotic and cirrhotic patients with NCT (2.6 vs. 4.2, p = 0.04) and T1W HBP (3.7 vs. 4.6; p = 0.01) images, with AUCs of 0.81 and 0.82, respectively. CONCLUSIONS: LSN measurement is highly reproducible with NCT and post-contrast T1W HBP on MRI, with different results obtained between CT and MRI.

3D-Printing of Meso-structurally Ordered Carbon Fiber/Polymer Composites with Unprecedented Orthotropic Physical Properties.

Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignment within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Furthermore, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response.

Effects of three intense sweeteners on fat storage in the C. elegans model.

Beverages sweetened with caloric sweeteners (CS), glucose, sucrose or high-fructose corn syrup, are associated with weight gain. Beverages sweetened with intense sweeteners (IS) are marketed as low-calorie substitutes to prevent beverages-associated weight gain. Using Caenorhabditis elegans, the effects on intestinal fat deposition (IFD) and pharyngeal pumping rate (PPR) of cola beverages sweetened with glucose, aspartame, or aspartame plus acesulfame-potassium (AceK) were compared. Control groups received Escherichia coli (OP50) only. Study I: the nematodes received additional glucose- or IS-sweetened beverages. Study II: the nematodes received additional glucose, aspartame, or aspartame plus AceK (AAK). Beverages containing CS or IS (aspartame or AAK) did not alter IFD in wild type (N2) or in daf-16 deficiency. The CS cola increased IFD in sir-2.1 deficiency (P<0.05). The AAK-cola increased IFD in daf-16/daf-2 deficiency and sir-2.1 deficiency (P<0.05). Glucose increased IFD in N2 and daf-16 deficiency (P<0.05). Aspartame showed a tendency towards reduced IFD in N2 and decreased IFD in daf-16/daf-2 deficiency (P<0.05). AAK increased IFD in daf-16 deficiency and sir-2.1 deficiency (P<0.05), and reversed the aspartame-induced reduction in IFD. The aspartame-sweetened cola increased the PPR in daf-16/daf-2 deficiency and daf-16 deficiency (P<0.05); similar results were obtained in N2 with both IS (P<0.05). AAK increased the PPR in daf-16/daf-2, daf-16, and sir-2.1 deficiencies (P<0.05). Thus, IS increased the PPR, a surrogate marker of lifespan. Aspartame may have an independent effect in reducing IFD to assist humans desiring weight loss. AceK may increase IFD in presence of insulin resistance.