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Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com, https://plus.google.com/communities/115462130054650919641?sqinv=VFJWaER0c2NCRl9ERzRjZWhxQmhzY09kVV84cjRn , ,https://plus.google.com/u/0/+AlexandrosGSfakianakis , https://www.youtube.com/channel/UCQH21WX8Qn5YSTKrlJ3OrmQ , https://www.youtube.com/channel/UCTREJHxB6yt4Gaqs4-mLzDA , https://twitter.com/g_orl?lang=el, https://www.instagram.com/alexandrossfakianakis/,

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Τετάρτη, 28 Μαρτίου 2018

Comparing the performances of Magnetic Resonance Imaging size versus pharmacokinetic parameters to predict response to neoadjuvant chemotherapy and survival in breast cancer patients

Publication date: Available online 28 March 2018
Source:Current Problems in Diagnostic Radiology
Author(s): Basak Dogan, Qing Yuan, Roland Bassett, Inanc Guvenc, Edward F. Jackson, Massimo Cristofanilli, Gary J. Whitman
PurposeTo compare the value of dynamic contrast-enhanced MRI (DCE-MRI)-pharmacokinetic (PK) parameters versus tumor volume in predicting breast cancer neoadjuvant chemotherapy response (NACR) and patient survival.Subjects and MethodsSixty-six patients with locally advanced breast cancer who underwent breast MRI monitoring of NACR were retrospectively analyzed. We compared baseline transfer constant (Ktrans), reflux rate contrast (kep), and extracellular extravascular volume fraction (ve) with the same parameters obtained at early post-chemotherapy MRI, and examined model-independent changes in time-intensity curves (maximum slope, contrast enhancement ratio, and IAUC90). Tumor size changes (tumor volume, single dimension, and RECIST) were also analyzed. The Spearman correlation test was used to assess the association between size and PK parameters, and regression analysis to assess the association with 5-year disease free survival.ResultsHigher ve values at baseline were associated with greater decreases in tumor size (P=0.008). Changes in Ktrans and IAUC90 were the strongest predictors of NACR. Changes in IAUC90 (P=0.04) and RECIST (P=0.003) were independently associated with pathological response. The only parameter significantly associated with 5-year survival was change in RECIST (P=0.001). However, there was a trend toward statistical significance for changes in ve and Ktrans, with greater changes associated with longer survival.ConclusionChanges in PK and DCE-MRI kinetic parameters may have a role in predicting NACR in breast tumors. While changes in Ktrans and IAUC90 are helpful in predicting NACR, they do not show significant association with survival. Early RECIST size change measured by MRI remains the strongest predictor of overall patient survival.



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Comparison of Natural Language Processing Rules-based and Machine-learning Systems to Identify Lumbar Spine Imaging Findings Related to Low Back Pain

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Publication date: Available online 28 March 2018
Source:Academic Radiology
Author(s): W. Katherine Tan, Saeed Hassanpour, Patrick J. Heagerty, Sean D. Rundell, Pradeep Suri, Hannu T. Huhdanpaa, Kathryn James, David S. Carrell, Curtis P. Langlotz, Nancy L. Organ, Eric N. Meier, Karen J. Sherman, David F. Kallmes, Patrick H. Luetmer, Brent Griffith, David R. Nerenz, Jeffrey G. Jarvik
Rationale and ObjectivesTo evaluate a natural language processing (NLP) system built with open-source tools for identification of lumbar spine imaging findings related to low back pain on magnetic resonance and x-ray radiology reports from four health systems.Materials and MethodsWe used a limited data set (de-identified except for dates) sampled from lumbar spine imaging reports of a prospectively assembled cohort of adults. From N = 178,333 reports, we randomly selected N = 871 to form a reference-standard dataset, consisting of N = 413 x-ray reports and N = 458 MR reports. Using standardized criteria, four spine experts annotated the presence of 26 findings, where 71 reports were annotated by all four experts and 800 were each annotated by two experts. We calculated inter-rater agreement and finding prevalence from annotated data. We randomly split the annotated data into development (80%) and testing (20%) sets. We developed an NLP system from both rule-based and machine-learned models. We validated the system using accuracy metrics such as sensitivity, specificity, and area under the receiver operating characteristic curve (AUC).ResultsThe multirater annotated dataset achieved inter-rater agreement of Cohen's kappa > 0.60 (substantial agreement) for 25 of 26 findings, with finding prevalence ranging from 3% to 89%. In the testing sample, rule-based and machine-learned predictions both had comparable average specificity (0.97 and 0.95, respectively). The machine-learned approach had a higher average sensitivity (0.94, compared to 0.83 for rules-based), and a higher overall AUC (0.98, compared to 0.90 for rules-based).ConclusionsOur NLP system performed well in identifying the 26 lumbar spine findings, as benchmarked by reference-standard annotation by medical experts. Machine-learned models provided substantial gains in model sensitivity with slight loss of specificity, and overall higher AUC.



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ESTRO ACROP guidelines for target volume definition in the treatment of locally advanced non-small cell lung cancer

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Publication date: Available online 28 March 2018
Source:Radiotherapy and Oncology
Author(s): Ursula Nestle, Dirk De Ruysscher, Umberto Ricardi, Xavier Geets, Jose Belderbos, Christoph Pöttgen, Rafal Dziadiuszko, Stephanie Peeters, Yolande Lievens, Coen Hurkmans, Ben Slotman, Sara Ramella, Corinne Faivre-Finn, Fiona McDonald, Farkhad Manapov, Paul Martin Putora, Cécile LePéchoux, Paul Van Houtte
Radiotherapy (RT) plays a major role in the curative treatment of locally advanced non-small cell lung cancer (NSCLC). Therefore, the ACROP committee was asked by the ESTRO to provide recommendations on target volume delineation for standard clinical scenarios in definitive (chemo)radiotherapy (RT) and adjuvant RT for locally advanced NSCLC. The guidelines given here are a result of the evaluation of a structured questionnaire followed by a consensus discussion, voting and writing procedure within the committee. Hence, we provide advice for methods and time-points of diagnostics and imaging before the start of treatment planning and for the mandatory and optional imaging to be used for planning itself. Concerning target volumes, recommendations are given for GTV delineation of primary tumour and lymph nodes followed by issues related to the delineation of CTVs for definitive and adjuvant radiotherapy. In the context of PTV delineation, recommendations about the management of geometric uncertainties and target motion are given. We further provide our opinions on normal tissue delineation and organisational and responsibility questions in the process of target volume delineation. This guideline intends to contribute to the standardisation and optimisation of the process of RT treatment planning for clinical practice and prospective studies.



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Practice patterns of image guided particle therapy in Europe: A 2016 survey of the European Particle Therapy Network (EPTN)

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Publication date: Available online 28 March 2018
Source:Radiotherapy and Oncology
Author(s): Alessandra Bolsi, Marta Peroni, Dante Amelio, Alexandru Dasu, Markus Stock, Iuliana Toma-Dasu, Petra Witt Nyström, Aswin Hoffmann
Background and purposeImage guidance is critical in achieving accurate and precise radiation delivery in particle therapy, even more than in photon therapy. However, equipment, quality assurance procedures and clinical workflows for image-guided particle therapy (IGPT) may vary substantially between centres due to a lack of standardization. A survey was conducted to evaluate the current practice of IGPT in European particle therapy centres.Material and methodsIn 2016, a questionnaire was distributed among 19 particle therapy centres in 12 European countries. The questionnaire consisted of 30 open and 37 closed questions related to image guidance in the general clinical workflow, for moving targets, current research activities and future perspectives of IGPT.ResultsAll centres completed the questionnaire. The IGPT methods used by the 10 treating centres varied substantially. The 9 non-treating centres were in the process to introduce IGPT. Most centres have developed their own IGPT strategies, being tightly connected to their specific technical implementation and dose delivery methods.ConclusionsInsight into the current clinical practice of IGPT in European particle therapy centres was obtained. A variety in IGPT practices and procedures was confirmed, which underlines the need for harmonisation of practice parameters and consensus guidelines.



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Susceptibility-weighted magnetic resonance imaging of cerebrovascular sequelae after radiotherapy for pediatric brain tumors

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Publication date: Available online 28 March 2018
Source:Radiotherapy and Oncology
Author(s): Marie A. Neu, Yasemin Tanyildizi, Arthur Wingerter, Nicole Henninger, Khalifa El Malki, Francesca Alt, Barbara Doerr, Heinz Schmidberger, Marcus Stockinger, Wolfgang Wagner, Stefanie Keweloh, Marc A. Brockmann, Alexandra Russo, Joerg Faber
Background and purposeDue to sensitive neuroimaging techniques, cerebrovascular complications such as cerebral microbleeds (CMB) and cerebral cavernous malformations (CCM) are increasingly recognized as considerable late effects after treatment for pediatric brain tumor. The aim of this study was to analyze CMB in a cohort of patients after cranial irradiation therapy for medulloblastoma or other pediatric brain tumors using susceptibility-weighted magnetic resonance imaging (SWI).Materials and methodsForty former pediatric brain tumor patients were enrolled in this prospective cross-sectional study and examined by cranial MRI including SWI sequences. Cerebral microbleeds, clinical symptoms and disability were evaluated.ResultsThirty-six (90%) of the examined individuals (mean follow-up age 22.2 y; mean follow-up time 13.5 y) were affected by CMB. Longer follow-up time and higher craniospinal irradiation doses correlated with higher total lesion count (p < 0.01). Thirteen patients (32.5%) presented with clinical symptoms. Individuals with CMB were more severely disabled than patients without CMB (p < 0.05).ConclusionsCerebrovascular sequelae occur frequently after treatment for pediatric brain tumor. In this study, a remarkable part of pediatric brain tumor patients presents with CMB. As a sign of vascular damage, they can cause clinical symptoms and may correspond to neurocognitive decline. Further studies are needed to standardize MRI protocols and to improve quality of long-term follow-up.



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Is accurate contouring of salivary and swallowing structures necessary to spare them in head and neck VMAT plans?

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Publication date: Available online 28 March 2018
Source:Radiotherapy and Oncology
Author(s): Alexander R. Delaney, Max Dahele, Ben J. Slotman, Wilko F.A.R. Verbakel
Background and purposeCurrent standards for organ-at-risk (OAR) contouring encourage anatomical accuracy which can be resource intensive. Certain OARs may be suitable for alternative delineation strategies. We investigated whether simplified salivary and swallowing structure contouring can still lead to good OAR sparing in automated head and neck cancer (HNC) plans.Materials and methodsFor 15 HNC patients, knowledge-based plans (KBPs) using RapidPlan™ were created using: (1) standard clinical contours for all OARs (benchmark-plans), (2) automated knowledge-based contours for the salivary glands, with standard contours for the remaining OARs (SS-plans) and (3) simplified contours (SC-plans) consisting of quick-to-draw tubular structures to account for the oral cavity, salivary glands and swallowing muscles. Individual clinical OAR contours in a RapidPlan™ model were combined to create composite salivary/swallowing structures. These were matched to tube-contours to create SC-plans. All plans were compared based on dose to anatomically accurate clinical OAR contours.ResultsSalivary gland delineation in SS-plans required on average 2 min, compared with 7 min for manual delineation of all tubular-contours. Automated atlas-based contours overlapped with, on average, 71% of clinical salivary gland contours while tube-contours overlapped with 95%/75%/93% of salivary gland/oral cavity/swallowing structure contours. On average, SC-plans were comparable to benchmark-plans and SS-plans, with average differences in composite salivary and swallowing structure dose ≤2 Gy and <1 Gy respectively.ConclusionsSimplified-contours could be created quickly and resulted in clinically acceptable HNC VMAT plans. They can be combined with automated planning to facilitate the implementation of advanced radiotherapy, even when resources are limited.



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The role of shear wave elastography on evaluation of the rigidity changes of corpus cavernosum penis in venogenic erectile dysfunction

Publication date: June 2018
Source:European Journal of Radiology, Volume 103
Author(s): Ailin Cui, Lili Xu, Jingjing Mu, Minghui Tong, Cheng Peng, Tingting Wu
ObjectiveThe goal of this study was to evaluate the effect of shear wave elastography (SWE) on the measurement of rigidity changes of penile erection in venogenic erectile dysfunction (ED) and in rigidity alterations of corpus cavernosum penis with age in normal population.MethodsThe study was a prospective analysis of 81 patients referred to the department of urology with complaints of ED as well as 35 healthy volunteers. SWE was performed on the corpus cavernosum penis (CCP) in the flaccid state of healthy group. The patients were divided into venogenic ED (31 patients) and non-vascular ED (neither arterial insufficiency nor venogenic dysfunction) (36 patients) by performing color doppler ultrasonography in association with intracavernous injection (ICI). SWE measurements were performed in CCP in the flaccid state, after 15–20 min and 25–30 min of ICI in both patients groups. Differences between groups were compared.ResultsAge was significantly negatively associated with SWE values of CCP among three groups (healthy group: r = −0.584, p < 0.05; venogenic ED group: r = −0.468, p < 0.05; non-vascular ED group: r = −0.539, p < 0.05). There was no significant difference between the SWE values of three groups in the flaccid state (p > 0.05). The mean SWE values of CCP were significantly lower in the erectile state (15–20 min after ICI) compared with the flaccid state in two patients groups (p < 0.05). The mean SWE values of CCP after ICI increased with time (from 15–20 min to 25–30 min) in patients with venogenic ED (p < 0.05), while the SWE values of CCP after ICI did not statistically significantly differ with time in patients with non-vascular ED (p > 0.05).ConclusionSWE is expected to be a promising approach in terms of the etiological diagnosis of ED and the quantitative evaluation of alternations of penile structures with age.



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Resting-state functional connectivity MRI analysis in Human Immunodeficiency Virus and Hepatitis C Virus co-infected subjects. A pilot study

Publication date: May 2018
Source:European Journal of Radiology, Volume 102
Author(s): Simone Corgiolu, Luigi Barberini, Jasjit S. Suri, Antonella Mandas, Diego Costaggiu, Paola Piano, Fulvio Zaccagna, Pierleone Lucatelli, Antonella Balestrieri, Luca Saba
Background and purposeHepatitis C virus (HCV) co-infection's role on cognitive impairment of human immunodeficiency virus (HIV) positive patients is still debated and functional neuroimaging evaluation on this matter is lacking. To provide further insight about HCV's neuro-effects on HIV associated neurocognitive disorder (HAND), we performed a pilot resting state (RS) functional connectivity magnetic resonance imaging (fcMRI) study to find eventual functional connectivity alteration that could reflect HCV related cognitive performance degradation.MethodsEighteen patients (8 HIV, 10 HIV + HCV), either impaired or not impaired, were assessed with RS fcMRI. A statistic model including cognitive testing results was elaborated during data processing to evaluate brain networks alteration related to actual cognitive status in patients.ResultsStatistically significant different patterns of connectivity were found: HCV co-infection modified 17 ROIs' connectivity with 45 supra-threshold connections (p-FDR min 0.0022, max 0.0497). ROIs most involved were right pallidum, brainstem, vermian lobules 1–2 and right cerebellar lobule 10. Graph theory analysis did not demonstrate significant difference between networks, but HCV related modifications at ROI's local level were found, with particular involvement of ROIs of frontal lobe, basal ganglia and cerebellum. Increased fronto-striatal dysfunctions have been already reported as consequences of HCV infection and could reflect an additive effect. Cerebellar alterations are associated with HIV and HAND, but not with HCV infection, suggesting a synergic effect of HCV.ConclusionOur study demonstrates RS fcMRI can help to understand the interactions between HIV and HCV co-infection, and our preliminary results suggest synergic effects of HCV in HIV-related brain functional modification.

Graphical abstract

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Peptide Receptor Radionuclide Therapy and the Treatment of Gastroentero-pancreatic Neuroendocrine Tumors: Current Findings and Future Perspectives

Abstract

Purpose and Methods

Patients with inoperable and metastasized neuroendocrine tumors (NETs), particularly those with grades 1 and 2, usually receive treatment with somatostatin analogues (SSAs). Peptide receptor radionuclide therapy (PRRT) has gained momentum over the past two decades in patients who progress on SSAs. 177Lu-DOTATATE is currently the most widely used radiopeptide for PRRT. We reviewed the recent evidence on PRRT and the treatment of gastroentero-pancreatic neuroendocrine tumors (GEP-NETs).

Results

177Lu-DOTATATE can be used as neoadjuvant treatment in patients with inoperable GEP-NETs, who might be candidate for surgery after treatment and as adjuvant therapy after surgical intervention. Combination treatments of PRRT with chemotherapy or targeted agents as well as combinations of radionuclides in patients with NETs have been explored over the last few years. The majority of patients with NETs experience partial response or have disease stabilization, a small percentage has complete response, while some 30% of patients, however, will have disease progression. The safety and efficacy of retreatment with extra cycles of PRRT as salvage therapy have been evaluated in small retrospective series.

Conclusion

Overall, there is evidence that disease control and quality of life improve significantly after 117Lu PRRT therapy. Clinical trials on this therapy are scarce, and there is a need for further studies to establish proper management guidelines.



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Aims and scope/Editorial board

Publication date: March 2018
Source:Journal of Forensic Radiology and Imaging, Volume 12





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Post-mortem computed tomography of cervical intervertebral separation: Retrospective review and comparison of the autopsy results of 57 separations

Publication date: March 2018
Source:Journal of Forensic Radiology and Imaging, Volume 12
Author(s): Seina Kudo, Yusuke Kawasumi, Akihito Usui, Makoto Arakawa, Naoto Yamagishi, Yui Igari, Masato Funayama, Tadashi Ishibashi
ObjectivesThe presence of an intervertebral separation indicates vertebral ligamentous injuries, and it is occasionally associated with fatal spinal cord injuries. However, it is often difficult to identify the separation using post-mortem computed tomography (CT). This study retrospectively evaluated the correlation between the post-mortem CT findings and autopsy results of cervical intervertebral separation.Materials and methodsForty-two subjects (8 females and 34 males) with cervical intervertebral separation were evaluated. The average age was 67 (range, 29–88) years. A radiologist retrospectively reviewed the cervical spines on axial, sagittal, and coronal CT images and determined whether intervertebral separations could be detected. The radiologist also classified the CT findings in cases with detectable separations.ResultsOf the 57 cervical intervertebral separations, 39 were detectable on the CT images. The CT findings were grouped into the following six categories: intervertebral gas (n = 19; 40.4%); forward intervertebral widening (n = 10; 21.3%); backward intervertebral widening (n = 1; 2.1%); anteroposterior misalignment (n = 6; 12.8%); spur fracture (n = 7; 14.9%); and hematoma in front of a vertebral body (n = 4; 8.5%). The sensitivity and specificity of intervertebral gas in the diagnosis of cervical intervertebral separation were 33.9% and 99.7%, respectively.ConclusionApproximately 70% of the cases with cervical intervertebral separations had various abnormal findings on CT imaging. The most common finding was intervertebral gas, but the sensitivity of intervertebral gas was not adequate.



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Corrigendum to: Forensic 3D documentation of bodies: simple and fast procedure for combining CT scanning with external photogrammetry data. [Journal of Forensic Radiology and Imaging (2017) 47–51]

Publication date: March 2018
Source:Journal of Forensic Radiology and Imaging, Volume 12





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Practice patterns of image guided particle therapy in Europe: A 2016 survey of the European Particle Therapy Network (EPTN)

Image guidance is critical in achieving accurate and precise radiation delivery in particle therapy, even more than in photon therapy. However, equipment, quality assurance procedures and clinical workflows for image-guided particle therapy (IGPT) may vary substantially between centres due to a lack of standardization. A survey was conducted to evaluate the current practice of IGPT in European particle therapy centres.

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Is accurate contouring of salivary and swallowing structures necessary to spare them in head and neck VMAT plans?

Current standards for organ-at-risk (OAR) contouring encourage anatomical accuracy which can be resource intensive. Certain OARs may be suitable for alternative delineation strategies. We investigated whether simplified salivary and swallowing structure contouring can still lead to good OAR sparing in automated head and neck cancer (HNC) plans.

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Susceptibility-weighted magnetic resonance imaging of cerebrovascular sequelae after radiotherapy for pediatric brain tumors

Due to sensitive neuroimaging techniques, cerebrovascular complications such as cerebral microbleeds (CMB) and cerebral cavernous malformations (CCM) are increasingly recognized as considerable late effects after treatment for pediatric brain tumor. The aim of this study was to analyze CMB in a cohort of patients after cranial irradiation therapy for medulloblastoma or other pediatric brain tumors using susceptibility-weighted magnetic resonance imaging (SWI).

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ESTRO ACROP guidelines for target volume definition in the treatment of locally advanced non-small cell lung cancer

Radiotherapy (RT) plays a major role in the curative treatment of locally advanced non-small cell lung cancer (NSCLC). Therefore, the ACROP committee was asked by the ESTRO to provide recommendations on target volume delineation for standard clinical scenarios in definitive (chemo)radiotherapy (RT) and adjuvant RT for locally advanced NSCLC. The guidelines given here are a result of the evaluation of a structured questionnaire followed by a consensus discussion, voting and writing procedure within the committee.

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Characteristic phase distribution in the white matter of infants on phase difference enhanced imaging

Publication date: Available online 28 March 2018
Source:Journal of Neuroradiology
Author(s): Tesu Niwa, Tetsuya Yoneda, Masaharu Hayashi, Keiji Suzuki, Shuhei Shibukawa, Takashi Okazaki, Yutaka Imai
Background and purposeThe infantile brain is continuously undergoing development. Non-invasive methods to assess the neurological development of infants are important for the early detection of abnormalities. Some microstructures in the brain have been demonstrated via phase difference-enhanced imaging (PADRE), which may reflect myelin-related microstructures. We aimed to assess the white matter (WM) signal distribution in infants using PADRE and compared it with that using T1-weighted images (T1WI) and diffusion tensor imaging (DTI) on magnetic resonance imaging (MRI).Materials and MethodThis study included 18 infants (post-conceptual age at MRI, 37–40 weeks) without abnormal findings on MRI. Signal distribution using T1WI, a fractional anisotropy (FA) map and PADRE was assessed regarding the following intraparenchymal structures: the optic radiation (OR), internal capsule (IC), corpus callosum, corticospinal tract (CST), semiovale center and subcortical regions.ResultsWe found that the signal distribution was significantly different (p < 0.001) with a relatively large signal change found at the IC and CST across the three imaging methods. Signal changes were also greater at the OR and rolandic subcortical WM on PADRE, whereas these were smaller on T1WI and FA.ConclusionPADRE demonstrated a characteristic phase shift distribution in infantile WM, which was different from that observed on T1WI and FA maps, and may demonstrate the developing myelin-related structures. PADRE can be a unique indicator of infantile brain development.



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Effect of Blood T1 Estimation Strategy on Arterial Spin Labeled Cerebral Blood Flow Quantification in Children and Young Adults with Kidney Disease

Publication date: Available online 28 March 2018
Source:Journal of Neuroradiology
Author(s): Hua-Shan Liu, Abbas F. Jawad, Nina Laney, Erum A. Hartung, Susan L. Furth, John A. Detre
PurposeTo compare blood T1 estimation approaches used for quantifying cerebral blood flow (CBF) with arterial spin labeled (ASL) perfusion MRI in a developmental cohort of chronic kidney disease (CKD) patients with anemia and a control group.Methods61 patients with CKD and 47 age-matched control subjects were studied. Blood T1 approaches included: (1) a fixed value, (2) estimation based on measured hematocrit (Hct), and (3) estimation based on Age+Sex using a published formula. Resulting T1 and CBF values were compared along with group, age and sex effects.ResultsHighly significant group differences in CBF using fixed blood T1 were reduced when Hct-corrected blood T1 was used, and were eliminated entirely when using the Age+Sex estimated approach. In the control cohort, fixed T1 method showed the strongest correlations of CBF with age and sex. Hct-corrected T1 preserved a significant correlation between CBF and age and sex, while Age+Sex estimated T1 produced a poor fit of CBF with age and sex.ConclusionsBlood T1 estimation method can confound the interpretation of CBF changes measured using ASL MRI in patients with CKD. Blood T1 should ideally be corrected for hematocrit effects in clinical populations with anemia.



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Dose Efficiency of Quarter-Millimeter Photon-Counting Computed Tomography: First-in-Human Results

Purpose The aim of this study was to assess the clinical feasibility, image quality, and radiation dose implications of 0.25-mm imaging mode in a cohort of humans, achieved by dividing the photon-counting detector (PCD) size in half compared with standard-resolution photon-counting computed tomography (CT) (0.5 mm). Methods In this technical feasibility study, a whole-body prototype PCD-CT scanner was studied in the 0.25 mm detector mode (measured at isocenter). A high-resolution PCD-CT protocol was first tested in phantom and canine studies in terms of image noise and spatial resolution. Then, 8 human subjects (mean age, 58 ± 8 years; 2 men) underwent axial PCD 0.25-mm scans of the brain, the thorax, and at the level of the upper left kidney. Filtered backprojection reconstruction was performed with a sharp kernel (B70) for standard-resolution and high-resolution data at 0.5-mm isotropic image voxel. High-resolution data, in addition, were reconstructed with an ultrasharp kernel (U70) at 0.25-mm isotropic voxels. Results Image reconstructions from the PCD 0.25-mm detector system led to an improvement in resolution from 9 to 18 line pairs/cm in a line pair phantom. Modulation transfer function improved from 9.5 to 15.8 line pairs/cm at 10% modulation transfer function. When fully exploiting this improvement, image noise increased by 75% compared with dose-matched 0.5-mm slice PCD standard-resolution acquisition. However, when comparing with standard-resolution data at same in-plane resolution and slice thickness, the PCD 0.25-mm detector mode showed 19% less image noise in phantom, animal, and human scans. Conclusion High-resolution photon-counting CT in humans showed improved image quality in terms of spatial resolution and image noise compared with standard-resolution photon-counting. Received for publication November 13, 2017; and accepted for publication, after revision, January 10, 2018. Conflicts of interest and sources of funding: This study was supported by the NIH Intramural Research Program and a collaborative research agreement with Siemens Healthcare GmbH (Forchheim, Germany). Data inclusion and analysis was performed by the authors who are not employees of or consultants for Siemens. Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (https://ift.tt/2kq7jVD). Correspondence to: Amir Pourmorteza, PhD, Department of Radiology and Imaging Sciences, Winship Cancer Institute of Emory University, 1701 Uppergate Drive, Suite 5018A, Atlanta, GA 30322. E-mail: amir.pourmorteza@emory.edu. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

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Low-Dose Characterization of Kidney Stones Using Spectral Detector Computed Tomography: An Ex Vivo Study

Objectives The aim of this study was to investigate the feasibility of kidney stone composition analysis using spectral detector computed tomography scanner (SDCT) with normal- and low-dose imaging protocols. Methods A total of 154 stones harvested from nephrolithotripsy or nephrolithotomy with a known monocrystalline composition as determined by infrared spectroscopy were examined in a nonanthropomorphic phantom on an SDCT (IQon, Philips, Best, the Netherlands). Imaging was performed with 120 kVp and (a) 40 mAs and (b) 200 mAs, resulting in a computed tomography dose index (CTDIvol) of 2 and 10 mGy, respectively. Besides conventional CT images (CIs), SDCT enables reconstruction of virtual monoenergetic images (40–200 keV). Spectral coefficient images were calculated by performing a voxel-by-voxel combination of 40 and 200 keV images (Matlab R2017b, Mathworks Inc). All stones were semiautomatically 3D-segmented on CI using a threshold-based algorithm implemented in an offline DICOM viewer. Statistical assessment was performed using Steel-Dwass method to adjust for multiple comparisons. Results Ca-phosphate (n = 22), Ca-oxalate (n = 82), cysteine (n = 20), struvite (n = 3), uric acid (n = 18), and xanthine stones (n = 9) were included in the analysis. Stone diameter ranged from 3.0 to 13.5 mm. On CI, attenuation differed significantly between calcific and noncalcific stones only (P ≤ 0.05), the spectral coefficient differed significantly between (//): Ca-oxalate//Ca-phosphate//cystine//struvite//uric acid//xanthine in 10 mGy protocol (all P ≤ 0.05). The same results were found for the 2 mGy-protocol, except that differentiation of Ca-oxalate and Ca-phosphate as well as uric acid and xanthine was not possible (P ≥ 0.05). Conclusions Spectral detector CT allows for differentiation of kidney stones using semi-automatic segmentation and advanced image post-processing, even in low-dose imaging protocols. Received for publication January 25, 2018; and accepted for publication, after revision, February 18, 2018. Conflict of Interest: DM received honoraria for talks outside this specific project from Philips. All other authors declare that there is no conflict of interest. University Hospitals and Case Western Reserve University received institutional research support from Philips (not related to this article). Correspondence to: Nils Große Hokamp, MD, Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. E-mail: nils.grosse-hokamp@uk-koeln.de. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

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Blended shared control utilizing online identification

Abstract

Purpose

Surgical robots are increasingly common, yet routine tasks such as tissue grasping remain potentially harmful with high occurrences of tissue crush injury due to the lack of force feedback from the grasper. This work aims to investigate whether a blended shared control framework which utilizes real-time identification of the object being grasped as part of the feedback may help address the prevalence of tissue crush injury in robotic surgeries.

Methods

This work tests the proposed shared control framework and tissue identification algorithm on a custom surrogate surgical robotic grasping setup. This scheme utilizes identification of the object being grasped as part of the feedback to regulate to a desired force. The blended shared control is arbitrated between human and an implicit force controller based on a computed confidence in the identification of the grasped object. The online identification is performed using least squares based on a nonlinear tissue model. Testing was performed on five silicone tissue surrogates. Twenty grasps were conducted, with half of the grasps performed under manual control and half of the grasps performed with the proposed blended shared control, to test the efficacy of the control scheme.

Results

The identification method resulted in an average of 95% accuracy across all time samples of all tissue grasps using a full leave-grasp-out cross-validation. There was an average convergence time of \(8.1 \pm 6.3\) ms across all training grasps for all tissue surrogates. Additionally, there was a reduction in peak forces induced during grasping for all tissue surrogates when applying blended shared control online.

Conclusion

The blended shared control using online identification more successfully regulated grasping forces to the desired target force when compared with manual control. The preliminary work on this surrogate setup for surgical grasping merits further investigation on real surgical tools and with real human tissues.



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Added value of double reading in diagnostic radiology,a systematic review

Abstract

Objectives

Double reading in diagnostic radiology can find discrepancies in the original report, but a systematic program of double reading is resource consuming. There are conflicting opinions on the value of double reading. The purpose of the current study was to perform a systematic review on the value of double reading.

Methods

A systematic review was performed to find studies calculating the rate of misses and overcalls with the aim of establishing the added value of double reading by human observers.

Results

The literature search resulted in 1610 hits. After abstract and full-text reading, 46 articles were selected for analysis. The rate of discrepancy varied from 0.4 to 22% depending on study setting. Double reading by a sub-specialist, in general, led to high rates of changed reports.

Conclusions

The systematic review found rather low discrepancy rates. The benefit of double reading must be balanced by the considerable number of working hours a systematic double-reading scheme requires. A more profitable scheme might be to use systematic double reading for selected, high-risk examination types. A second conclusion is that there seems to be a value of sub-specialisation for increased report quality. A consequent implementation of this would have far-reaching organisational effects.

Key Points

• In double reading, two or more radiologists read the same images.

• A systematic literature review was performed.

• The discrepancy rates varied from 0.4 to 22% in various studies.

• Double reading by sub-specialists found high discrepancy rates.



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Endocavitary contrast enhanced ultrasound (CEUS): a novel problem solving technique

Abstract

Contrast-enhanced ultrasound (CEUS) is a technique that has developed as an adjunct to conventional ultrasound. CEUS offers a number of benefits over conventional axial imaging with computerised tomography and magnetic resonance imaging, primarily as a "beside" test, without ionising radiation or the safety concerns associated with iodinated/gadolinium-based contrast agents. Intravascular use of ultrasound contrast agents (UCAs) is widespread with extensive evidence for effective use. Despite this, the potential utility of UCAs in physiological and non-physiological cavities has not been fully explored. The possibilities for endocavitary uses of CEUS are described in this review based on a single-centre experience including CEUS technique and utility in confirming drain placement, as well as within the biliary system, urinary system, gastrointestinal tract and intravascular catheters.

Teaching Points

• CEUS offers an excellent safety profile, spatial resolution and is radiation free.

• Endocavitary CEUS provides real-time imaging similar to fluoroscopy in a portable setting.

• Endocavitary CEUS can define internal architecture of physiological cavities.

• Endocavitary CEUS can confirm drain position in physiological and non-physiological cavities.



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Dose Efficiency of Quarter-Millimeter Photon-Counting Computed Tomography: First-in-Human Results

Purpose The aim of this study was to assess the clinical feasibility, image quality, and radiation dose implications of 0.25-mm imaging mode in a cohort of humans, achieved by dividing the photon-counting detector (PCD) size in half compared with standard-resolution photon-counting computed tomography (CT) (0.5 mm). Methods In this technical feasibility study, a whole-body prototype PCD-CT scanner was studied in the 0.25 mm detector mode (measured at isocenter). A high-resolution PCD-CT protocol was first tested in phantom and canine studies in terms of image noise and spatial resolution. Then, 8 human subjects (mean age, 58 ± 8 years; 2 men) underwent axial PCD 0.25-mm scans of the brain, the thorax, and at the level of the upper left kidney. Filtered backprojection reconstruction was performed with a sharp kernel (B70) for standard-resolution and high-resolution data at 0.5-mm isotropic image voxel. High-resolution data, in addition, were reconstructed with an ultrasharp kernel (U70) at 0.25-mm isotropic voxels. Results Image reconstructions from the PCD 0.25-mm detector system led to an improvement in resolution from 9 to 18 line pairs/cm in a line pair phantom. Modulation transfer function improved from 9.5 to 15.8 line pairs/cm at 10% modulation transfer function. When fully exploiting this improvement, image noise increased by 75% compared with dose-matched 0.5-mm slice PCD standard-resolution acquisition. However, when comparing with standard-resolution data at same in-plane resolution and slice thickness, the PCD 0.25-mm detector mode showed 19% less image noise in phantom, animal, and human scans. Conclusion High-resolution photon-counting CT in humans showed improved image quality in terms of spatial resolution and image noise compared with standard-resolution photon-counting. Received for publication November 13, 2017; and accepted for publication, after revision, January 10, 2018. Conflicts of interest and sources of funding: This study was supported by the NIH Intramural Research Program and a collaborative research agreement with Siemens Healthcare GmbH (Forchheim, Germany). Data inclusion and analysis was performed by the authors who are not employees of or consultants for Siemens. Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (https://ift.tt/2kq7jVD). Correspondence to: Amir Pourmorteza, PhD, Department of Radiology and Imaging Sciences, Winship Cancer Institute of Emory University, 1701 Uppergate Drive, Suite 5018A, Atlanta, GA 30322. E-mail: amir.pourmorteza@emory.edu. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

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Low-Dose Characterization of Kidney Stones Using Spectral Detector Computed Tomography: An Ex Vivo Study

Objectives The aim of this study was to investigate the feasibility of kidney stone composition analysis using spectral detector computed tomography scanner (SDCT) with normal- and low-dose imaging protocols. Methods A total of 154 stones harvested from nephrolithotripsy or nephrolithotomy with a known monocrystalline composition as determined by infrared spectroscopy were examined in a nonanthropomorphic phantom on an SDCT (IQon, Philips, Best, the Netherlands). Imaging was performed with 120 kVp and (a) 40 mAs and (b) 200 mAs, resulting in a computed tomography dose index (CTDIvol) of 2 and 10 mGy, respectively. Besides conventional CT images (CIs), SDCT enables reconstruction of virtual monoenergetic images (40–200 keV). Spectral coefficient images were calculated by performing a voxel-by-voxel combination of 40 and 200 keV images (Matlab R2017b, Mathworks Inc). All stones were semiautomatically 3D-segmented on CI using a threshold-based algorithm implemented in an offline DICOM viewer. Statistical assessment was performed using Steel-Dwass method to adjust for multiple comparisons. Results Ca-phosphate (n = 22), Ca-oxalate (n = 82), cysteine (n = 20), struvite (n = 3), uric acid (n = 18), and xanthine stones (n = 9) were included in the analysis. Stone diameter ranged from 3.0 to 13.5 mm. On CI, attenuation differed significantly between calcific and noncalcific stones only (P ≤ 0.05), the spectral coefficient differed significantly between (//): Ca-oxalate//Ca-phosphate//cystine//struvite//uric acid//xanthine in 10 mGy protocol (all P ≤ 0.05). The same results were found for the 2 mGy-protocol, except that differentiation of Ca-oxalate and Ca-phosphate as well as uric acid and xanthine was not possible (P ≥ 0.05). Conclusions Spectral detector CT allows for differentiation of kidney stones using semi-automatic segmentation and advanced image post-processing, even in low-dose imaging protocols. Received for publication January 25, 2018; and accepted for publication, after revision, February 18, 2018. Conflict of Interest: DM received honoraria for talks outside this specific project from Philips. All other authors declare that there is no conflict of interest. University Hospitals and Case Western Reserve University received institutional research support from Philips (not related to this article). Correspondence to: Nils Große Hokamp, MD, Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany. E-mail: nils.grosse-hokamp@uk-koeln.de. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

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Letter from the new Editor-in-Chief for Insights into Imaging



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SUPRA: open-source software-defined ultrasound processing for real-time applications

Abstract

Purpose

Research in ultrasound imaging is limited in reproducibility by two factors: First, many existing ultrasound pipelines are protected by intellectual property, rendering exchange of code difficult. Second, most pipelines are implemented in special hardware, resulting in limited flexibility of implemented processing steps on such platforms.

Methods

With SUPRA, we propose an open-source pipeline for fully software-defined ultrasound processing for real-time applications to alleviate these problems. Covering all steps from beamforming to output of B-mode images, SUPRA can help improve the reproducibility of results and make modifications to the image acquisition mode accessible to the research community. We evaluate the pipeline qualitatively, quantitatively, and regarding its run time.

Results

The pipeline shows image quality comparable to a clinical system and backed by point spread function measurements a comparable resolution. Including all processing stages of a usual ultrasound pipeline, the run-time analysis shows that it can be executed in 2D and 3D on consumer GPUs in real time.

Conclusions

Our software ultrasound pipeline opens up the research in image acquisition. Given access to ultrasound data from early stages (raw channel data, radiofrequency data), it simplifies the development in imaging. Furthermore, it tackles the reproducibility of research results, as code can be shared easily and even be executed without dedicated ultrasound hardware.



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CXCR4/CXCR7/CXCL12-Axis in Follicular Thyroid Carcinoma.

Related Articles

CXCR4/CXCR7/CXCL12-Axis in Follicular Thyroid Carcinoma.

J Cancer. 2018;9(6):929-940

Authors: Werner TA, Forster CM, Dizdar L, Verde PE, Raba K, Schott M, Knoefel WT, Krieg A

Abstract
Background: Follicular thyroid carcinoma's (FTC) often benign course is partially due to adjuvant radioactive iodine (RAI) treatment. However, once the tumour has spread and fails to retain RAI, the therapeutic options are limited and the outcome is poor. In this subset of patients, the identification of novel druggable biomarkers appears invaluable. Here, we investigated the stage dependent expression and functional role of the C-X-C chemokine receptors type 4 and 7 (CXCR4/7) in FTC. Methods: CXCR4/7 expression was examined in 44 FTC and corresponding non-neoplastic thyroid specimens as well as 10 FTC distant metastases and 18 follicular adenomas using tissue microarray technology. Expression levels were correlated with clinicopathological variables as well as overall and recurrence free survival. Changes regarding cell cycle activation, tumour cell invasiveness and mRNA expression of genes related to epithelial-mesenchymal transition (EMT) were investigated after treatment with recombinant human SDF1α/CXCL12 (rh-SDF1α) and CXCR4 antagonists AMD3100 and WZ811. Results: CXCR4/7 expression was associated with large tumour size, advanced UICC stage as well as shorter overall and recurrence free survival. CXCR4 was significantly higher expressed in distant metastases than in primary tumour cores. In addition, rh-SDF1α induced invasive growth, cell cycle activation and EMT, while CXCR4 antagonists significantly reduced FTC invasiveness in vitro. Conclusion: Here we provide first evidence of the biological importance of the CXCR4/CXCR7/CXCL12 axis in FTC. Our findings underscore the therapeutic potential of this chemokine receptor family in advanced FTC and offer new valuable insight into the oncogenesis of metastatic FTC.

PMID: 29581772 [PubMed]



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The incidence of occult metastasis and the status of elective neck dissection in salivary adenoid cystic carcinoma: a single center study.

Related Articles

The incidence of occult metastasis and the status of elective neck dissection in salivary adenoid cystic carcinoma: a single center study.

Oral Surg Oral Med Oral Pathol Oral Radiol. 2018 Feb 02;:

Authors: Cordesmeyer R, Kauffmann P, Laskawi R, Rau A, Bremmer F

Abstract
OBJECTIVE: Adenoid cystic carcinoma (ACC) is characterized by a high rate of local recurrence and late distant metastasis. The status of an elective neck dissection (END) is controversial in the literature.
STUDY DESIGN: In this study we retrospectively analyzed the surgical treatment and follow-up examinations of 59 patients with ACCs of a salivary gland treated in a single center between 1980 and 2016.
RESULTS: The incidence of occult nodal metastases among all patients who underwent END was 20.6%. The overall survival and the disease-free survival of patients who underwent END versus patients without END had no significant differences. Even in the case of positive lymph nodes metastasis there was no significant benefit in survival or local recurrence control.
CONCLUSION: The incidence of occult neck metastases in patients with ACC was 20.6%. There was no significant enhanced survival in the group of patients who underwent an END.

PMID: 29580669 [PubMed - as supplied by publisher]



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Medication-related osteonecrosis of the jaw: An update on the memorial sloan kettering cancer center experience and the role of premedication dental evaluation in prevention.

Related Articles

Medication-related osteonecrosis of the jaw: An update on the memorial sloan kettering cancer center experience and the role of premedication dental evaluation in prevention.

Oral Surg Oral Med Oral Pathol Oral Radiol. 2018 Feb 14;:

Authors: Owosho AA, Liang STY, Sax AZ, Wu K, Yom SK, Huryn JM, Estilo CL

Abstract
OBJECTIVE: The aim of this study was to investigate the relationship between type of antiresorptive medication and medication-related osteonecrosis of the jaw (MRONJ) onset and the role of premedication dental evaluation (PMDE) in the prevention of MRONJ.
STUDY DESIGN: Our database of patients with MRONJ was reviewed. The Kruskal-Wallis test was used to analyze the onset dose of the 3 frequent medication types associated with MRONJ. To evaluate the role of PMDE in the prevention of MRONJ, all patients on antiresorptive and/or antiangiogenic medications seen in the Dental Service of Memorial Sloan Kettering Cancer Center during a 10-year period were subclassified into 2 groups. Group I comprised patients seen for PMDE before the commencement of A/A and group II patients seen after prior exposure to antiresorptive and/or antiangiogenic medications. Fischer's exact test was used to compare the incidence of MRONJ in both groups.
RESULTS: Patients on denosumab developed MRONJ earlier compared with zoledronate and pamidronate (P = .003). Group I had a significantly reduced incidence of MRONJ (0.9%) compared with group II (10.5%) (P < .0001). Dentoalveolar trauma as a precipitating factor between groups I and II was not statistically significant.
CONCLUSIONS: Denosumab was associated with an earlier occurrence of MRONJ compared with zoledronate and pamidronate. The role of PMDE may be an effective preventive strategy in reducing the incidence of MRONJ.

PMID: 29580668 [PubMed - as supplied by publisher]



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Alterations of White Matter Connectivity in Preschool Children with Autism Spectrum Disorder.

Alterations of White Matter Connectivity in Preschool Children with Autism Spectrum Disorder.

Radiology. 2018 Mar 27;:170059

Authors: Li SJ, Wang Y, Qian L, Liu G, Liu SF, Zou LP, Zhang JS, Hu N, Chen XQ, Yu SY, Guo SL, Li K, He MW, Wu HT, Qiu JX, Zhang L, Wang YL, Lou X, Ma L

Abstract
Purpose To investigate the topologic architecture of white matter connectivity networks in preschool-aged children with a diagnosis of autism spectrum disorder (ASD) versus typical development (TD). Materials and Methods Forty-two participants were enrolled, including 21 preschool children with ASD (14 male children and seven female children; mean age, 4.56 years ± 0.97 [standard deviation]) and 21 children with TD (11 males and 10 females; mean age, 5.13 years ± 0.82). The diagnosis of ASD was determined according to the Diagnostic and Statistical Manual of Mental Disorders Global Assessment of Functioning scores (mean score, 8.00 ± 0.50). All participants underwent diffusion-tensor imaging (DTI) and T2-weighted imaging on a 3-T magnetic resonance system. A graph theoretical analysis was applied to investigate the topologic organization of the brain network including global and local topologic parameters. Statistical analysis was then performed for the comparison between the groups. Results Compared with the TD group, children with ASD demonstrated shortened characteristic path length (t1 = 0.536, t2 = 0.534, t3 = 0.523, t4 = 0.510, and t5 = 0.501; P < .05) and increased global efficiency (t1 = 0.499, t2 = 0.497, t3 = 0.486, t4 = 0.473, and t5 = 0.465; P < .05) and clustering coefficient (t1 = 0.673, t2 = 0.750, t3 = 0.757, t4 = 0.738, and t5 = 0.741; P < .05). Significant increases in nodal efficiency were mainly found in left pallidum (0.037 vs 0.032, respectively; P < .01) and right caudate nucleus (0.037 vs 0.032, respectively; P < .01) of the basal ganglia network. Conclusion Significantly altered patterns of global and local brain network topography may underlie the abnormal brain development in preschool children with ASD compared with those who have TD. The identification of altered structural connectivity in basal ganglia and paralimbic-limbic networks may point toward potential imaging biomarkers for preschool-age patients with ASD. © RSNA, 2018.

PMID: 29584599 [PubMed - as supplied by publisher]



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Use of 2D U-Net Convolutional Neural Networks for Automated Cartilage and Meniscus Segmentation of Knee MR Imaging Data to Determine Relaxometry and Morphometry.

Use of 2D U-Net Convolutional Neural Networks for Automated Cartilage and Meniscus Segmentation of Knee MR Imaging Data to Determine Relaxometry and Morphometry.

Radiology. 2018 Mar 27;:172322

Authors: Norman B, Pedoia V, Majumdar S

Abstract
Purpose To analyze how automatic segmentation translates in accuracy and precision to morphology and relaxometry compared with manual segmentation and increases the speed and accuracy of the work flow that uses quantitative magnetic resonance (MR) imaging to study knee degenerative diseases such as osteoarthritis (OA). Materials and Methods This retrospective study involved the analysis of 638 MR imaging volumes from two data cohorts acquired at 3.0 T: (a) spoiled gradient-recalled acquisition in the steady state T1ρ-weighted images and (b) three-dimensional (3D) double-echo steady-state (DESS) images. A deep learning model based on the U-Net convolutional network architecture was developed to perform automatic segmentation. Cartilage and meniscus compartments were manually segmented by skilled technicians and radiologists for comparison. Performance of the automatic segmentation was evaluated on Dice coefficient overlap with the manual segmentation, as well as by the automatic segmentations' ability to quantify, in a longitudinally repeatable way, relaxometry and morphology. Results The models produced strong Dice coefficients, particularly for 3D-DESS images, ranging between 0.770 and 0.878 in the cartilage compartments to 0.809 and 0.753 for the lateral meniscus and medial meniscus, respectively. The models averaged 5 seconds to generate the automatic segmentations. Average correlations between manual and automatic quantification of T1ρ and T2 values were 0.8233 and 0.8603, respectively, and 0.9349 and 0.9384 for volume and thickness, respectively. Longitudinal precision of the automatic method was comparable with that of the manual one. Conclusion U-Net demonstrates efficacy and precision in quickly generating accurate segmentations that can be used to extract relaxation times and morphologic characterization and values that can be used in the monitoring and diagnosis of OA. © RSNA, 2018 Online supplemental material is available for this article.

PMID: 29584598 [PubMed - as supplied by publisher]



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Advanced Hepatocellular Carcinoma: Pretreatment Contrast-enhanced CT Texture Parameters as Predictive Biomarkers of Survival in Patients Treated with Sorafenib.

Advanced Hepatocellular Carcinoma: Pretreatment Contrast-enhanced CT Texture Parameters as Predictive Biomarkers of Survival in Patients Treated with Sorafenib.

Radiology. 2018 Mar 27;:171320

Authors: Mulé S, Thiefin G, Costentin C, Durot C, Rahmouni A, Luciani A, Hoeffel C

Abstract
Purpose To determine whether texture features on pretreatment contrast material-enhanced computed tomographic (CT) images can help predict overall survival (OS) and time to progression (TTP) in patients with advanced hepatocellular carcinoma (HCC) treated with sorafenib. Materials and Methods This retrospective study included 92 patients with advanced HCC treated with sorafenib between January 2009 and April 2015 at two independent university hospitals. Sixty-four of the 92 patients (70%) (six women, 58 men; median age, 66 years) were included from institution 1 and constituted a training cohort; 28 patients (30%) (five women, 23 men; median age, 64 years) were included from institution 2 and constituted a validation cohort. Pretreatment CT texture analysis was performed on late arterial and portal venous phase HCC images. Mean gray-level intensity, entropy, kurtosis, skewness, and standard deviation values were derived from the pixel distribution histogram before and after spatial filtration at different anatomic scales ranging from fine to coarse texture. Lesion heterogeneity was also visually graded on a 4-point scale. Correlations between visual analysis and texture parameters were assessed with the Spearman rank correlation. Univariate Kaplan-Meier and multivariate Cox proportional hazards regression analyses were performed in the training cohort to identify independent predictors of OS and TTP. Their predictive capacity was tested on the validation cohort by using Kaplan-Meier analysis. Results Visual analysis of tumor heterogeneity correlated with entropy at both arterial (P = .012) and portal venous (P = .038) phases. Portal phase-derived entropy at fine (hazard ratio [HR], 5.08; P = .0033), medium (HR, 2.23; P = .019), and coarse (HR, 2.26; P = .0032) texture scales was identified as an independent predictor of OS and confirmed in the validation cohort (P < .05). The difference in median survival between patients in the validation cohort with entropy values below and above the identified threshold was 272 days (with fine texture) and 741 days (with medium and coarse textures). Arterial phase-derived texture parameters (P > .085) and visual analysis (P > .11) were not associated with changes in survival. Conclusion Pretreatment portal venous phase-derived tumor entropy may be a predictor of survival in patients with advanced HCC treated with sorafenib.

PMID: 29584597 [PubMed - as supplied by publisher]



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Estimating the Patient-specific Dose to the Thyroid and Breasts and Overall Risk in Chest CT When Using Organ-based Tube Current Modulation.

Estimating the Patient-specific Dose to the Thyroid and Breasts and Overall Risk in Chest CT When Using Organ-based Tube Current Modulation.

Radiology. 2018 Mar 27;:170757

Authors: Franck C, Smeets P, Lapeire L, Achten E, Bacher K

Abstract
Purpose To assess the potential dose reduction to the thyroid and breasts in chest computed tomography (CT) with organ-based tube current modulation (OBTCM). Materials and Methods In this retrospective study (from January 2015 to December 2016), the location of the breasts with respect to the reduced tube current zone was determined. With Monte Carlo simulations, patient-specific dose distributions of chest CT scans were calculated for 50 female patients (mean age, 53.7 years ± 17.5; range, 20-80 years). The potential dose reduction with OBTCM was assessed. In addition, simulations of clinical OBTCM scans were made for 17 of the 50 female patients (mean age, 43.8 years ± 17.1; range, 20-69 years). Posterior organs in the field of view were analyzed and lifetime attributable risk (LAR) of cancer incidence and mortality was estimated. Image quality between standard CT and OBTCM scans was compared. Results No women had all breast tissue within the reduced tube current zone. Dose reductions of 18% in the thyroid and 9% in the breasts were observed, whereas the doses in lung, liver, and kidney were 17%, 11%, and 26% higher. Overall, the LAR for cancer incidence was not significantly different between conventional and OBTCM scanning (P = .06). Image quality improved with OBTCM (P < .002). Conclusion The potential benefit of OBTCM to the female breast in chest CT is overestimated because of a limited reduced tube current zone; despite a 9% dose reduction to the female breast, posterior organs will absorb up to 26% more radiation, resulting in no reduction in radiation-induced malignancies. © RSNA, 2018.

PMID: 29584596 [PubMed - as supplied by publisher]



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Unresectable Intrahepatic Cholangiocarcinoma: Multiparametric MR Imaging to Predict Patient Survival.

Unresectable Intrahepatic Cholangiocarcinoma: Multiparametric MR Imaging to Predict Patient Survival.

Radiology. 2018 Mar 27;:171593

Authors: Pandey A, Pandey P, Aliyari Ghasabeh M, Najmi Varzaneh F, Shao N, Khoshpouri P, Zarghampour M, Fadaei Fouladi D, Liddell R, Kamel IR

Abstract
Purpose To determine the performance of magnetic resonance (MR) imaging-based tumor metrics for evaluation of response to transarterial chemoembolization (TACE) in patients with unresectable intrahepatic cholangiocarcinoma (ICCA). Materials and Methods Ninety-four patients with unresectable ICCA underwent baseline and follow-up MR imaging after TACE and were followed up until death or end of study duration. Lesions were analyzed for anatomic (Response Evaluation Criteria in Solid Tumors [RECIST] and tumor volume) and functional (viable tumor volume, viable tumor burden, and apparent diffusion coefficient [ADC]) volumetric MR parameters by using semiautomatic software. Response was assessed by using changes in viable tumor volume by using modified RECIST (mRECIST)-derived thresholds (three-dimensional mRECIST), viable tumor burden, and ADC. Overall survival was the primary endpoint. Cox-regression and Kaplan-Meier survival analysis were used. Results Tumor volume did not change after TACE (P = .07) whereas RECIST diameter showed a small change (-2.6%; P = .02). There was an increase in ADC (20.7%) and a decrease in viable tumor volume (-29.3%) and viable tumor burden (-29.1%; P < .001 for all). Higher overall survival was noted among responders by using thresholds of 25% increase in ADC, 66% decrease in viable tumor volume, and 50% decrease in viable tumor burden (log-rank test, P < .05). Hazard ratio for nonresponders by using ADC, three-dimensional mRECIST, and viable tumor burden at multivariable analysis was 2.9 (P = .004), 4.1 (P = .009), and 4.0 (P = .002), respectively. Survival differences were noted for patients who showed response by using all three parameters (ADC, three-dimensional mRECIST, and viable tumor burden) versus those who showed response by using either one or two of these parameters versus those who showed no response (P < .001). Conclusion Changes in volumetric ADC, viable tumor volume, and viable tumor burden at MR imaging provide prognostic information among patients with unresectable ICCA who undergo TACE. © RSNA, 2018 Online supplemental material is available for this article.

PMID: 29584595 [PubMed - as supplied by publisher]



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Acoustic Radiation Force Impulse US Imaging: Liver Stiffness in Patients with Chronic Hepatitis B with and without Antiviral Therapy.

Acoustic Radiation Force Impulse US Imaging: Liver Stiffness in Patients with Chronic Hepatitis B with and without Antiviral Therapy.

Radiology. 2018 Mar 27;:171116

Authors: Su TH, Liao CH, Liu CH, Huang KW, Tseng TC, Yang HC, Liu CJ, Chen PJ, Chen DS, Kao JH

Abstract
Purpose To investigate the clinical utility and longitudinal change of acoustic radiation force impulse (ARFI) ultrasonographic (US) imaging in patients with chronic hepatitis B. Materials and Methods A retrospective cohort study of patients with chronic hepatitis B who underwent serial ARFI examinations in a tertiary referral center in Taiwan between 2012 and 2016 was conducted. The clinical information and noninvasive liver stiffness measurement tests (ARFI, Fibrosis-4 index [FIB-4], and FibroScan) were collected. Serial ARFI measurements were compared in patients without antiviral therapy (nontreatment group) and during antiviral therapy (treatment group). The linear mixed-effects model with random coefficients was used to compare longitudinal repeated measurements. Results A total of 559 patients undergoing serial ARFI examinations were included. The ARFI value correlated with FIB-4 (correlation coefficient = 0.55, P < .001) and FibroScan (correlation coefficient = 0.69, P < .001) results. There were 314 patients with five or more ARFI measurements in more than 3 years of follow-up. The ARFI value remained unchanged in the nontreatment group (n = 189, from 1.11 to 1.11 m/sec, time trend P = .911). However, the ARFI value declined significantly in the treatment group (n = 125, from 1.63 to 1.37 m/sec, time trend P < .001), both in patients with cirrhosis (n = 51, from 2.15 to 1.75 m/sec, time trend P < .001) and in those without (n = 74, from 1.27 to 1.11 m/sec, time trend P < .001). Conclusion ARFI US imaging is an important clinical noninvasive test for liver stiffness measurement and can be used for serial measurements in the management of chronic hepatitis B. Antiviral therapy significantly reduces liver stiffness during longitudinal follow-up.

PMID: 29584594 [PubMed - as supplied by publisher]



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Outcome of Architectural Distortion Detected Only at Breast Tomosynthesis versus 2D Mammography.

Outcome of Architectural Distortion Detected Only at Breast Tomosynthesis versus 2D Mammography.

Radiology. 2018 Mar 27;:171159

Authors: Alshafeiy TI, Nguyen JV, Rochman CM, Nicholson BT, Patrie JT, Harvey JA

Abstract
Purpose To compare the outcome of architectural distortion (AD) without associated mass only on digital breast tomosynthesis (DBT) with AD seen at two-dimensional (2D) mammography and to evaluate if the incidence of malignancy is influenced by the presence of a correlate at ultrasonography (US). Materials and Methods This retrospective study had institutional review board approval and was HIPAA compliant. All consecutive cases in which patients with AD were ultimately assigned Breast Imaging Reporting and Data System (BI-RADS) 4 or 5 categories from 2009 to 2016 were reviewed by three readers for visibility (2D vs DBT). The level of suspicion was assigned using a Likert scale. Pathologic results were compared between 2D-detected and DBT-detected AD. Frequencies were compared by using the McNemar and Pearson χ2 exact tests. Results One hundred eighty-one AD lesions were included; 122 (67.4%) were 2D visible while 59 (32.6%) were DBT detected. Forty-two women (with 43 lesions) underwent 2D mammography prior to initiation of DBT. In 117 women with 121 AD lesions who underwent 2D mammography plus DBT, 59 lesions (48.8%) were detected only with DBT. The malignancy rate based on final pathology was significantly higher for 2D-detected AD (53 [43.4%] of 122) compared with DBT (six [10.2%] of 59) (P < .001). A US correlate was more frequent with 2D-detected AD (103 [84.4%] of 122) than DBT (33 [55.9%] of 59) (P < .001). Malignancy rate was not different for DBT-detected AD with (four [12.1%] of 33; 95% confidence interval [CI]: 3.4%, 28.2%]) or without (two [7.7%] of 26; 95% CI: 0.9%, 25.1%]) a US correlate. NPV based on radiologists' level of suspicion was high (91.8%-98.0%) but not sufficient enough to forgo biopsy. Conclusion DBT-detected suspicious AD has a lower malignancy outcome compared with 2D mammography-detected suspicious AD, although still high enough to warrant biopsy. © RSNA, 2018 Online supplemental material is available for this article.

PMID: 29584593 [PubMed - as supplied by publisher]



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Evaluation of particulate 137Cs discharge from a mountainous forested catchment using reservoir sediments and sinking particles

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Hironori Funaki, Kazuya Yoshimura, Kazuyuki Sakuma, Shatei Iri, Yoshihiro Oda
The time and size dependencies of particulate 137Cs concentrations in a reservoir were investigated to evaluate the dynamics of 137Cs pollution from a mountainous forested catchment. Sediment and sinking particle samples were collected using a vibracorer and a sediment trap at the Ogaki Dam Reservoir in Fukushima, which is located in the heavily contaminated area that formed as a result of the Fukushima Dai-ichi Nuclear Power Plant accident of 2011. The inventory of 137Cs discharged into the reservoir during the post-accident period (965 days) was estimated to be approximately 3.0 × 1012–3.9 × 1012 Bq, which is equivalent to 1.1%–1.4% of the initial estimated catchment inventory. The particulate 137Cs concentration showed a decline with time, but the exponent value between the specific surface area and the 137Cs concentration for the fine-sized (<63 μm) particle fraction remained almost constant from the immediate aftermath of the accident. These quantitative findings obtained by reconstructing the contamination history of particulate 137Cs in reservoir sediments and sinking particles have important implications for the evaluation of 137Cs dynamics in mountainous forested catchments.



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