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PURPOSE: Percutaneous tissue biopsy is a mainstay of diagnostic and interventional radiology, providing a minimally invasive method for diagnosing malignant and benign disease. The purpose of this review was to collect and summarize the best available evidence regarding the risk factors associated with bleeding complications in image-guided liver biopsy. METHODS: A literature review was performed, searching Medline, EMBASE, CINAHL, the Cochrane Library, the National Institute for Health and Care Excellence (NICE) and Canadian Agency for Drugs and Technology in Health (CADTH) databases for any studies evaluating bleeding complications in image-guided liver biopsy. A total of 68 articles, published between January 1994 and April 2015, were reviewed in full, with 34 ultimately eligible for inclusion in the review. RESULTS: Bleeding of any kind occurred in up to 10.9% of image-guided liver biopsies, with major bleeding episodes ranging from 0.1% to 4.6% and minor bleeding events occurring in up to 10.9% of biopsies. The overall rate of bleeding was, however, found to be less than 2%. Several risk factors (patient, operator, and procedure-related) were identified as potentially indicative of an increased risk of post-biopsy bleeding. Patient-related risk factors included patient age (>50 years or <2 years), inpatient status (8/12 vs. 4/12, P < 0.001), comorbidities and/or concurrent diagnoses and coagulation status (rate of bleeding was 3.3% for international normalized ratio [INR] 1.2–1.5 vs. 7.1% for INR >1.5, P < 0.001). There was no consensus on impact of operator experience (>200 biopsies/year vs. <50/year) on post-biopsy bleeding rate. Procedure-related risk factors included needle size (cutting biopsy vs. fine needle aspiration, P < 0.001) and the presence of a patent track on post-biopsy ultrasound (P < 0.001). Lastly there was no difference found between targeted vs. nontargeted biopsies and number of needle passes. CONCLUSION: Reported rate of post-biopsy bleeding ranges between 0% and 10.9%, although the vast majority of studies reported bleeding rates under 2%. Several patient, operator, and procedure-related risk factors are associated with a higher risk of bleeding following liver biopsy.

PurposeThere are no published guidelines on the follow-up imaging of non-operatively managed blunt splenic trauma (BST). We conducted an international survey of emergency radiologists to determine the ideal patient population, time period, and technique for follow-up imaging of BST.MethodsAn anonymous 10-question online survey was distributed via email to 34 emergency radiologists around the world. The survey was open for a 2-week period in 2019. A commercially available website (SurveyMonkey®) was used for survey generation and data acquisition.ResultsWe received 29 responses (85% response rate) primarily from USA, Canada, and Europe. Majority of the institutions handled > 1000 trauma cases (69%). The initial protocol consisted of arterial and portal venous phases (PVP) in 72% of responses. Sixty-two percent of the institutions did not have a routine protocol for follow-up imaging of BST. There was no consensus on which patients received follow-up imaging. The most frequent responses had been case-per-case basis or injuries above a set AAST grade (42% and 37%, respectively). There was no set time period for follow-up imaging, but MDCT was most often performed at 24–48 h. Dual-phase protocol was utilized most commonly (69%). Majority of the institutions (88%) utilized angioembolization for hemodynamically stable patients with contained vascular injury or active extravasation.ConclusionThere is no consensus on the optimal patient population or time period for follow-up imaging of BST. A dual-phase follow-up MDCT protocol is utilized for follow-up by majority of institutions.

Pneumothorax development can cause precipitous deterioration in ICU patients, therefore quick and accurate detection is vital. Portable chest radiography is commonly performed to exclude pneumothoraces but is hampered by supine patient position and overlying internal and external material. Also, the initial evaluation of the chest radiograph may be performed by a relatively inexperienced physician. Therefore, a tool that could significantly improve pneumothorax detection on portable radiography would be helpful in patient care. The aim of this study was to evaluate the clinical utility of novel enhancement software for pneumothorax detection in readers with varied clinical experience of detecting/excluding pneumothoraces on portable chest radiographs in ICU patients. 206 portable ICU chest radiographs, 103 with pneumothoraces, were processed with and without enhancement software and reviewed by 5 readers who varied in reading experience. Images were grouped for different complexity levels. The mean AUC for pneumothorax detection increased for 4/5 readers from 0.846-0.957 to 0.88-0.971 with a largest improvement for the reader with least experience. No significant change was noted for the reader with the longest reading experience. The image complexity had no impact on the interpretation result. Pneumothorax detection improves with novel enhancement software; the largest improvement is seen in less experienced readers.

Formation of the anteroposterior and dorsoventral body axis in Caenorhabditis elegans depends on cortical flows and advection of polarity determinants. The role of this patterning mechanism in tissue polarization after formation of cell-cell contacts is not fully understood. Here, we demonstrate that planar asymmetries are established during left-right symmetry breaking: Centripetal cortical flows asymmetrically and differentially advect anterior polarity determinants (aPARs) from contacts to the medial cortex, resulting in their unmixing from apical myosin. Contact localization and advection of PAR-6 requires balanced CDC-42 activation, while asymmetric retention and advection of PAR-3 can occur independently of PAR-6. Concurrent asymmetric retention of PAR-3, E-cadherin/HMR-1 and opposing retention of antagonistic CDC-42 and Wnt pathway components leads to planar asymmetries. The most obvious mark of planar asymmetry, retention of PAR-3 at a single cell-cell contact, is required for proper cytokinetic cell intercalation. Hence, our data uncover how planar polarity is established in a system without the canonical planar cell polarity pathway through planar asymmetric retention of aPARs.

Objectives To compare the diagnostic performance of international hepatocellular carcinoma (HCC) guidelines with gadoxetic acid-enhanced MRI (EOB-MRI) and contrast-enhanced Computed tomography (CECT) and their impact on liver transplant (LT) allocation in cirrhotic patients with explant histopathology correlation. Methods In this prospective single-centre ethics-approved study, 101 cirrhotic patients were consecutively enrolled with informed consent from the pre-LT clinic. They underwent CECT and EOB-MRI alternately at three monthly intervals until LT or removal from LT list. Two abdominal radiologists, blinded to explant histopathology, independently recorded liver lesions visible on CECT and EOB-MRI. Imaging-based HCC scores were assigned to non-treated liver lesions utilizing 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 Association-National Cancer Center (KLCA) guidelines. Liver explant histopathology was the reference standard. Simulated LT eligibility was assessed as per Milan criteria (MC) in reference to explant histopathology. Results One hundred and three non-treated HCC and 12 non-HCC malignancy were identified at explant histopathology in 34 patients (29 men, 5 women, age 55–73 years). Higher HCC sensitivities of statistical significance were observed with EOB-MRI for LI-RADS 4 + 5, APASL and KLCA compared to LI-RADS 5 and EASL with greatest sensitivity obtained for LIRADS 4 + 5 lesions. HCC sensitivities by all guidelines with both EOB-MRI and CECT were significantly lower if all histopathology-detected HCCs were included in the analysis, compared to imaging-visible lesions only. A significantly greater variation in HCC sensitivity was noted across the guidelines with EOB-MRI compared to CECT. No significant differences in simulated LT eligibility based on MC were observed across the HCC scoring guidelines with EOB-MRI or CECT. Conclusion HCC sensitivities are variable depending on scoring guideline, lesion size and imaging modality utilised. Prior studies that included only lesions visible on pre-operative imaging overestimate the diagnostic performance of HCC scoring guidelines. Per-lesion differences in HCC diagnosis across these guidelines did not impact patient-level LT eligibility based on MC.

Objectives To compare the image quality and radiation dose using image-noise (IN)-based determination of X-ray tube settings compared with a body mass index (BMI)-based protocol during CT coronary angiography (CTCA). Methods Two hundred consecutive patients referred for CTCA to our institution were divided into two groups: BMI-based, 100 patients had CTCA with the X-ray tube current adjusted to the patient’s BMI while maintaining a fixed tube potential of 120 kV; IN-based, 100 patients underwent imaging with the X-ray tube current and voltage adjusted to the IN measured within the mid-left ventricle on a pre-acquisition trans-axial image. Two independent cardiac radiologists performed blinded image quality assessment with quantification of the IN and signal-to-noise ratio (SNR) from the mid-LV and qualitative assessment using a three-point score. Radiation dose (CTDI and DLP) was recorded from the console. Results Results showed: IN (HU): BMI-based, 30.1 ± 9.9; IN-based, 33.1 ± 6.7; 32 % variation reduction ( P  = 0.001); SNR: BMI-based, 18.6 ± 7.1; IN-based, 15.4 ± 3.7; 48 % variation reduction ( P  < 0.0001). Visual scores: BMI-based, 2.3 ± 0.6; IN-based, 2.2 ± 0.5 ( P  = 0.54). Radiation dose: CTDI (mGy), BMI-based, 22.68 ± 8.9; IN-based, 17.16 ± 7.6; 24.3 % reduction ( P  < 0.001); DLP (mGy.cm), BMI-based, 309.3 ± 127.5; IN-based, 230.6 ± 105.5; 25.4 % reduction ( P  < 0.001). Conclusions Image-noise-based stratification of X-ray tube parameters for CTCA results in 32 % improvement in image quality and 25 % reduction in radiation dose compared with a BMI-based protocol. Key Points • Image quality and radiation dose are closely related in CT coronary angiography. • So too are the image quality, radiation dose and body mass index (BMI). • An image-noise-based CTCA protocol reduces the radiation dose by 25 %. • It improves inter-patient image homogeneity by 32 %.

We previously showed that the sequential, but not simultaneous, culture of endothelial cells (ECs), fibroblasts (FBs), and cardiomyocytes (CMs) resulted in elongated, beating cardiac organoids. We hypothesized that the expression of Cx43 and contractile function are mediated by vascular endothelial growth factor (VEGF) released by nonmyocytes during the preculture period. Cardiac organoids (∼200 μm diameter) were cultivated in microchannels to enable rapid screening. Three experimental groups were formed: (i) Simultaneous Preculture (ECs+FBs for 48 h, followed by CMs), (ii) Sequential Preculture (ECs for 24 h, FBs for 24 h, followed by CMs), and (iii) Simultaneous Triculture (ECs+FBs+CMs). Controls included CMs only, FBs only, and ECs only groups, and preculture with ECs only or FBs only. The highest VEGF levels were found in the Preculture groups [Simultaneous Preculture, 8.9±2.7 ng/(mL·h −1 ); Sequential Preculture, 16.6±3.4 ng/(mL·h −1 )], as compared with Simultaneous Triculture where VEGF was not detectable, as shown by enzyme-linked immunosorbent assay. Analytical flow cytometry showed that VEGFR2 was expressed by ECs (86%±2 VEGFR2+), FBs (44%±1 VEGFR2+), and CMs (49%±2 VEGFR2+), showing that all three cell types were capable of responding to changes in VEGF. Addition of anti-VEGF neutralizing IgG (0.4 μg/mL) to Simultaneous Preculture resulted in 3-fold decrease in Cx43 mRNA and 1.5-fold decrease in Cx43 protein, while Simultaneous Triculture supplemented with VEGF ligand (30 ng/mL) had a threefold increase in Cx43 mRNA and a twofold increase in Cx43 protein. Addition of a small molecule inhibitor of the VEGFR2 receptor (19.4 nM) to Sequential Preculture caused a 1.4-fold decrease in Cx43 mRNA and a 4.1-fold decrease in Cx43 protein. Cx43 was localized within CMs, and not within FBs or ECs. Enriched CM organoids and Sequential Preculture organoids grown in the presence of VEGFR2 inhibitor displayed low levels of Cx43 and poor functional properties. Taken together, these results suggest that endogenous VEGF-VEGFR2 signaling enhanced Cx43 expression and cardiac function in engineered cardiac organoids.

Formation of the anteroposterior and dorsoventral body axis in the Caenorhabditis elegans embryo depends on cortical actomyosin flows and advection of polarity determinants. The role of this patterning mechanism in tissue polarization immediately after formation of cell-cell contacts is not fully understood. Here, we demonstrate that planar cell polarity (PCP) is established in the C. elegans embryo at the time of left-right (l/r) symmetry breaking. At this stage, centripetal cortical flows asymmetrically and differentially advect anterior polarity determinants (aPARs) PAR-3, PAR-6 and PKC-3 from cell-cell contacts to the medial cortex, which results in their unmixing from apical myosin. Advection generally requires GSK-3 and CDC-42, while advection of PAR-6 specifically depends on the RhoGAP PAC-1. Concurrent asymmetric retention of PAR-3, E-cadherin/HMR-1, PAC-1 and opposing retention of the antagonistic Wnt pathway components APC/APR-1 and Frizzled/MOM-5 at apical cell-cell contacts leads to planar asymmetries. The most obvious mark of PCP, asymmetric retention of PAR-3 at posterior cell-cell contacts on the left side of the embryo, is required for proper cytokinetic cell intercalation. Hence, our data uncover how PCP can be established through Wnt signaling as well as dissociation and planar asymmetric retention of aPARs mediated by distinct Rho GTPases and their regulators.

During animal development, it is crucial that cells can sense and adapt to mechanical forces from their environment. Ultimately, these forces are transduced through the actomyosin cortex. How the cortex can simultaneously respond to and create forces during cytokinesis is not well understood. Here we show that under mechanical stress, cortical actomyosin flow switches its polarization during cytokinesis in the C. elegans embryo. In unstressed embryos, longitudinal cortical flows contribute to contractile ring formation, while rotational cortical flow is additionally induced in uniaxially loaded embryos. Rotational cortical flow is required for the redistribution of the actomyosin cortex in loaded embryos. Rupture of longitudinally aligned cortical fibers during cortex rotation releases tension, initiates orthogonal longitudinal flow and thereby contributes to furrowing in loaded embryos. A targeted screen for factors required for rotational flow revealed that actomyosin regulators involved in RhoA regulation, cortical polarity and chirality are all required for rotational flow and become essential for cytokinesis under mechanical stress. In sum, our findings extend the current framework of mechanical stress response during cell division and show scaling of orthogonal cortical flows to the amount of mechanical stress.