bluuebunny/crossref_metadata_2025 huggingface dataset:
PEMANFAATAN DASAR KONSEPTUAL PERENCANAAN PEMBELAJARAN IPS DI SMP 2 KUALUH SELATAN
Authors: Br. Tanjung Halimatussa’ Diyah , Pasaribu Lisa Khairiah , Jhonson Anhar
Published: August 2023

Penelitian ini bertujuan untuk mendeskripsikan pemanfaatan dasar konseptual perencanaan pembelajaran ips di SMP N 2 Kualuh Selatan. Metode penilitian yang digunakan yaitu metode kualitatif. Pentingnya Perencanaan Pembelajaran diantaranya merupakan pembelajaran adalah proses yang bertujuan. pembelajaran adalah proses kerjasama, proses pembelajaran adalah proses yang kompleks dan proses pembelajaran yang efektif. Ini berarti penekanan primer pada perencanaan pembelajaran merupakan ketercapaian tujuan dan perencanaan pembelajaran berisi ihwal rangkaian kegiatan yang harus dilaksanakan buat mencapai tujuan. Manfaat yang dirasakan guru berasal perencanaan pembelajaran yang dilakukan merupakan melalui proses perencanaan yang matang, serta dapat memecahkan masalah dan buat memanfaatkan banyak sekali asal belajar secara tepat. Kompetensi guru seperti yang kita ketahui guru ialah faktor utama sekaligus kunci dalam belajar mengajar, disini sangat di lihat kualitas guru dimana jika kualitas guru baik maka kualitas pembelajarannya juga baik karena tanpa adanya peranan guru proses belajar mengajar musthahil dapat terlaksana. Keterampilan guru juga perlu dikembangkan serta di miliki oleh guru tersebut bukan hanya keterampilan dalam hal terkomunikasi namun juga dalam hal lainnya. Kemampuan pendidik atau guru juga dijelaskan dalam undang-undang guru dan dosen, kemampuan kepribadian, kemampuan sosial, kemampuan pedagogik dan kemampuan profesional yang di lakukan secara bertanggung jawab.
PEMBINAAN AKHLAK REMAJA DI DESA TELUK PANJI KECAMATAN KAMPUNG RAKYAT KABUPATEN LABUHANBATU SELATAN
Authors: Pratama Wahyuda , Siregar Parluhutan , Damanik Agusman
Published: August 2023

Penelitian ini bertujuan agar mengetahui akhlak remaja di desa Teluk Panji kecamatan Kampung Rakyat Kabupaten Labuhan Batu Selatan melalui peran Ustaz serta bagaimana cara Ustaz tersebut agar berhasil membentuk akhlak yang baik pada remaja yang ada di Desa tersebut sesuai dengan ajaran dan syariat Islam. Penelitian ini menggunakan metode kualitatif deskriptif dengan cara melakukan survei secara langsung ke desa tersebut serta menganalisis dan mengamati apasaja perkembangan yang ada disana melalui diskusi dengan cara tanya jawab, wawancara, dengan para remaja, uztad, dan kepala desa setempat. Hasil penelitian ini, salah satu jenis kegiatan pembinaan yang dilakukan melalui berbagai program yang berkesinambungan, dapat mendongkrak moral remaja yang cenderung melakukan kesalahan.  Majelis Taklim Ikhlasiyah dan berhasil dalam usahanya memperbaiki diri melalui taubat dan pendekatan kepada Allah SWT. Adapun yang menjadi Pemicu dan penghambat dalam pelaksanaan kegiatan pembinaan akhlak remaja adalah: Adanya hubungan baik antara masyarakat sekitar dengan Desa Teluk Panji Kecamatan Kampung Rakyat Kabupaten Labuhan Batu Selatan yang menjadi pengurus dan anggota Majelis Taklim Al-Ikhlasiyah. Banyak masyarakat yang terlibat dalam mendukung semua kegiatan Majelis Taklim Al-Ikhlasiyah. Selain itu, faktor yang menghambat perkembangan moral antara lain: IPTEK dan menggunakan waktu yang ada dengan penerapan disiplin yang baik.
Adaptation of Meta-Cognitive Awareness Inventory in Physics (MAIP) for Public and Private Senior Secondary School Nigerian Students
Authors: Barnabas Ellah , Emaikwu Sunday Oche
Published: August 2023

Purpose: The study focused on the adaptation of the Meta-Cognitive Awareness Inventory in Physics (MAIP) for senior secondary school students in Nigeria, both in public and private schools. Methodology: The study employed an adaptation research design. The sample included 1,382 SSII students who had taken Physics as a subject. To ensure its validity, the MAIP underwent face validation by five experts. Construct validation of the MAIP was conducted using factor analysis. This involved applying the principal component analysis extraction method and the Varimax rotation method with Kaiser Normalization. Items with a factor loading of 0.40 or higher on any of the factors were selected to be included in the instrument. The coefficient of internal consistency was calculated using Cronbach's Alpha and was found to be 0.78. Research question 1 was addressed through factor analysis, while research question 2 was answered by calculating the coefficient of internal consistency using Cronbach's Alpha. Research question 3 was answered by calculating means and standard deviations. The null hypothesis was tested using an independent t-test at a significance level of 0.05. Findings: The findings of the study revealed that the MAIP consisted of 52 factorially simple or pure items and 23 factorially complex items based on their factor loadings. Significance: The coefficient of internal consistency for the MAIP was found to be 0.98. Furthermore, a statistically significant difference in the mean meta-cognitive awareness ratings was observed between students in private and public schools, favoring students in private senior secondary schools when using the MAIP.
La suppression de la limitation du nombre de mandats présidentiels au Cameroun : analyse de la bifurcation de la trajectoire d’une politique institutionnelle
Authors: André Tchoupie
Published: August 2023

This study uses the theoretical and methodological frameworks of the analysis of public policies and neo-institutionalism (in particular historical institutionalisms and rational choice) to investigate the manner in which the reversal of the evolution trend of institutional policy in Cameroon without revealing its weaknesses and justifying the necessity of its re-adaptation. The study demonstrates that the constitutional revision which ushered in the reinstatement of a perpetual re-eligibility of the President of the Republic here in Cameroon has taken a path characterized by the predominance ofstrategic interactions between stakeholders who are dynamically active in and around the political arena while working for the desired or not desired shift of trajectory of Cameroonian politic. To confront this situation, state authorities have mobilized various resources to ensure the preeminence of their perception of the reality. The study concludes by positing that the issue of keeping or shifting institutions’ trajectories, as set in place in Africa during the ‘third wave ofdemocratisation’, is at the center of political struggles, and determines to a large extent the degree of satisfaction which they bring to different stakeholders in the sociopolitical game.
Management und Organisation von Arbeitsbeziehungen in der Psychiatrie
Authors: Dirksen Ralf-Gero C.
Published: August 2023

Wie sieht der aktuelle Zustand der Psychiatrie in managementwissenschaftlicher Perspektive aus? Während wissenschaftliche Persönlichkeiten heute immer noch soziologische Terminologien der sechziger Jahre zur Beschreibung verwenden, möchte der vorliegende Aufsatz die Entwicklungslinie psychiatrischer Organisationen von den Anfängen sozialwissenschaftlicher Forschung in den 60er Jahren des 20. Jahrhunderts bis in die Gegenwart des Konzepts der Inklusion skizzieren. Dabei liegt die Aufmerksamkeit insbesondere auf dem organisationalen Interaktionssystem von Mitarbeitenden und Patient:innen. Als Methoden kommen eine „teilnehmende Beobachtung“ auf der Grundlage regelmäßiger Aufzeichnungen, selektive Literaturrecherche und eine darauf aufbauende deskriptive Modellbildung zum Einsatz. Als Ergebnis lässt sich festhalten, dass zeitgemäße Instrumente des strategischen Managements, der systemischen Organisationsentwicklung und Kommunikation zu einer nachhaltigen Humanisierung der psychiatrischen Versorgung geführt haben, auch wenn immer noch Devianzen und gesellschaftliche Defizite existieren. Vornehmliche Managementaufgabe psychiatrischer Einrichtungen bleibt aber auch heute noch die aktive Entstigmatisierung psychisch erkrankter Menschen.
Digital Era, Digitale Transformation und Digital Red Tape – ein Debattenbeitrag zur Digitalisierungsforschung
Authors: Drathschmidt Nicolas
Published: August 2023

Mehr als 15 Jahre, nachdem eine neue digitale Post-NPM Ära ausgerufen wurde, fehlt es der Digitalisierungsforschung weiterhin an Tiefe. Während interne Prozesse und Verfahren oft unbeachtet blieben, lag der Fokus in der Vergangenheit auf der Untersuchung digitaler Dienstleistungen an der Schnittstelle zwischen Verwaltung und Bürger. Um Forschung in diesem Bereich zu konsolidieren, schlägt dieser Debattenbeitrag vor, klassische Ansätze für die Digitalisierungsforschung „fit“ zu machen. Anschließend sollten Effekte der Digitalisierung, insbesondere auf die Effizienz von Organisationen (auch negative Auswirkungen z.B. durch Digital Red Tape), innerhalb der Verwaltung analysiert werden. Dafür muss jedoch beantwortet werden, wie Digitalisierung gemessen und operationalisiert werden kann.
Erfindung – Recycling – Neukomposition
Authors: Grabow Martin
Published: August 2023

Die einzelnen Werke Pierre Boulez’ sind durch offene oder verborgene Querverweise Teil eines faszinierenden Beziehungsgeflechts. Dieser bislang wenig beachtete Aspekt seines Schaffens und die dafür charakteristischen Kompositions- und Bearbeitungstechniken stehen im Fokus der vorliegenden Analysen und Quellenstudien. Im Laufe seines Lebens kommt Boulez unter sich wandelnden ästhetischen Prämissen auf die 1945 komponierten 'douze notations pour piano' zurück. Während er 1957 Teile des zunächst unveröffentlichten Jugendwerks unbemerkt als Fundus für 'Pli selon pli' und für eine Hörspielmusik nutzt, wendet er sich ihnen ab 1970 offen zu, und die aufwändigen Neukompositionen als 'Notations pour orchestre' wachsen sich zu einem der Hauptprojekte des reifen Komponisten und erfahrenen Dirigenten aus. Die Bearbeitung – vorher Mittel zum Zweck – ist zum Selbstzweck geworden und die Selbstbezüglichkeit – vorher im Verborgenen – zum Kennzeichen seines Œuvres. Mit dieser Entwicklung scheint Boulez ganz zu sich selbst zu finden: Zentrum seines Komponierens war immer das – im weitesten Sinne – „Bearbeiten“ von Vorhandenem und nicht die Erfindung ex nihilo.
Polen im 21. Jahrhundert
Authors: Vetter Reinhold
Published: August 2023

Since the beginning of Russia's war against Ukraine, the European public has also been looking at Poland. As Ukraine's direct neighbour, Poland plays an important role in providing aid to the troubled country. However, the domestic political development under Poland's national conservative government has been arousing concern across Europe since 2015. Time and again, there are conflicts between the EU and Poland's government. Reinhold Vetter examines the reasons and causes of this development by analysing the quality of the Polish constitution and political system, the strengths and weaknesses of the economy and social systems, Poland's position in the EU and NATO, and the attitude of its citizens towards parliamentary democracy.
Evaluation of Serum Zinc Levels in Children of 6 Months to 5 Years of Age Diagnosed with Simple Febrile Seizures
Authors: Oguz Saide Busra , Kacar Alper , Dikker Okan , Dag Huseyin
Published: August 2023

Background: Febrile seizures are defined as seizures associated with a febrile illness that developed without central nervous system infection or acute electrolyte imbalance, intoxication, trauma, and metabolic disorder in children aged 1 month to 5 years without previous afebrile seizures. Various studies show a relationship between zinc levels and febrile seizures. Objectives: The purpose of this study was to examine the relationship between serum zinc levels and febrile seizures. Methods: This prospective, cross-sectional, and descriptive study was conducted from 04/10/2021 to 04/02/2022. A total of 85 children aged 6 months to 5 years admitted to the pediatric emergency service of the Republic of Turkey Ministry of Health Cemil Taşcıoğlu City Hospital were included in the study. The patients who met the inclusion criteria and whose consent was obtained were included in the study. Complex and febrile status patients were not included in the study due to the small number of patients. The cases included in the study were divided into 2 groups of patients and healthy controls. The patients with fever were divided into 2 groups, including those with and without febrile seizures. The levels of zinc and complete blood count parameters were measured in the blood samples taken from all the patients. IBM SPSS 22 package software was used for the statistical examination of the data. Results: When the cases included in this study were divided according to gender, 33 (38.8%) and 52 (61.2%) patients were female and male, respectively. The mean age of the cases was 29.2 ± 15.9 months (range: 6 - 60). Of the 85 participating cases, 30 patients had febrile seizures, 30 were only febrile patients, and 25 were healthy controls. When zinc levels were compared between the groups, the plasma zinc levels of the febrile seizures and febrile groups were observed to be lower than the healthy control group (P < 0.05). Conclusions: In this study, the group consisting of patients with febrile seizures and the groups of patients who had a fever but did not have febrile seizures during the study had reduced serum zinc levels than the control group consisting of healthy patients without fever.
Principal Supervision in Improving Teacher Pedagogic Competence in Elementary Schools in Pidie District
Authors: Karmila Karmila , Khairuddin Khairuddin , Bahrun Bahrun
Published: August 2023

Supervision is an activity to assist teachers in developing their ability to manage learning to achieve the expected goals in learning. Supervision aims to provide services and assistance to improve the quality of teaching and learning for teachers in the classroom, in turn to produce quality student learning. The aim of the research was to find out how the principal's supervision improves the pedagogical competence of teachers in elementary schools in Pidie District. This research uses a qualitative approach with descriptive methods. Data collection techniques are carried out through observation, interviews, and documentation. Data analysis techniques, namely by collecting data, reducing data, presenting data, and drawing conclusions. The research subjects were school principals, teachers, staff, students, and parents in Pidie District. The results of the study found: (1) the program planned by the principal to develop teachers was a supervision program; (2) The implementation of supervision is carried out by the principal to help teachers improve their competence, provide directions, and help teachers find joint solutions to the constraints being faced. The supervision techniques used are individual supervision techniques and group supervision techniques; (3) Evaluation is carried out at the end of the odd semester and the end of the even semester. Follow-up is carried out to find solutions to the problems being faced; (4) The supporting factors of the academic supervision program include a conducive school culture; (5) The inhibiting factor for supervision activities is the teacher's readiness when supervised, the teacher still considers supervision as a scourge, not a need for good.
Curriculum Development Management of Integrated IPS Subject at MTsN Banda Aceh
Authors: Anita Anita , Harun Cut Zahri , Yusrizal Yusrizal
Published: August 2023

Management or curriculum management becomes something very important, because good curriculum management will facilitate the achievement of educational goals to the maximum. The purpose of this study is to find out how the management of integrated social studies subject curriculum development in MTsN Banda Aceh city. This research uses a qualitative approach with a descriptive type of research. Data collection techniques use observation, interviews, and documentation. The data analysis techniques used are qualitative descriptive analysis with data reduction techniques, data presentation, and conclusions. Based on the research findings, it was found that: (1) The planning process for the development of an integrated social studies curriculum is carried out in meeting activities held at the end of each school year or before the beginning of the new school year begins, by setting goals to be achieved; (2) The organization of curriculum development consists of the main organization of the school curriculum development team and also the organization of the social studies curriculum and the Madrasah MGMP team; (3) The staff preparation process shall be deliberated directly by the Head of Madrasah and the coordinator for school curriculum development. Staffing in accordance with expertise and considering the issue of equal distribution of tasks; (4) The implementation of curriculum development has been very good, effective and efficient. The implementation of curriculum development is also carried out through MGMP; (5) Obstacles experienced by Waka Curriculum in developing an integrated social studies subject curriculum are due to lack of teacher motivation, difficulty in managing time and lack of adequate infrastructure; and (6) The Waka Curriculum solution in developing an integrated social studies subject curriculum, namely: involving social studies teachers in MGMP, providing all school infrastructure, providing support to teachers in the implementation of the educational process, and there must be teacher motivation.
Regional diffusion imaging changes related to obesity, after adjusting for other risk factors: the UK Biobank study
Authors: Wartolowska Karolina , Webb Alastair
Published: August 2023

Small vessel disease is a common cause of white matter damage in older people. It is strongly associated with age, hypertension, diabetes, and obesity. We have investigated the associations between body mass index (BMI) and diffusion changes (adjusted for other risk factors) in data from UK Biobank. BMI was more strongly related to diffusion changes in inferior brain regions, depending on whether the white matter tracts were within the anterior or posterior circulation. Obesity affects white matter integrity, beyond the effect of cardiovascular risk factors.
A disentangled representation trained for joint reconstruction and segmentation of radially undersampled cardiac MRI
Authors: Wech Tobias , Heidenreich Julius , Bley Thorsten , Baeßler Bettina
Published: August 2023

The network we propose in this work (xSDNet) jointly reconstructs and segments cardiac functional MR images which were sampled below the Nyquist rate. The model is based on disentangled representation learning and factorizes images into spatial factors and a modality vector. The achieved image quality and the fidelity of the delivered segmentation masks promise a considerable acceleration of both acquisition and data processing.
Free-running isotropic whole-heart T2 mapping with ECG-free Pilot Tone navigation
Authors: Rumac Simone , Roy Christopher , Yerly Jérôme , Falcao Mariana B. L. , Bustin Aurélien , Bacher Mario , Speier Peter , Stuber Matthias , van Heeswijk Ruud
Published: August 2023

The most commonly employed T2 mapping techniques are 2D and make use of ECG-triggering. This may be a limitation in patients with variable heart rate and complex three-dimensional conditions. To address these limitations, we here propose an isotropic free-running 3D T2 mapping technique that avoids ECG triggering by using Pilot Tone navigation. In three healthy volunteers, our technique produced accurate isotropic T2 maps when compared to 2D T2 prepared bSSFP (T2=41.1±4.8ms vs. 44.9±3.3ms, respectively, p=0.1), and cardiac motion was successfully resolved.
Integrated high-order B0 shimming for multiparametric quantitative liver imagingat 3T using a UNIfied Coil (UNIC)
Authors: Wang Nan , Serry Fardad , Ocasio Michael , Xie Yibin , Huang Yuheng , Li Xinqi , Han Pei , Cao Tianle , Ma Sen , Han Fei , Minton Matthew , Cai Yubin , Shan Yujie , Bi Xiaoming , Christodoulou Anthony , Yang Hsin-Jung , Li Debiao , Han Hui
Published: August 2023

Liver MRI shows promise for rich morphologic and physiologic information. B0 inhomogeneity causes off-resonance spread at the liver-lung interfaces, degrading image quality and quantification accuracy for DWI, T1, and T2*/R2*. A novel high-order shim coil (UNIC) was built, minimizing the decoupling between the two overlapped shim and RF arrays, allowing the free design of shim loop topology in proximity of the target organ. Improved shimming from UNIC is demonstrated with increased FOV in liver imaging, showing significantly reduced distortion in liver DWI, increased image quality score of MOLLI T1 map, and reduced B0-offset-induced ADC, R2*, and B0 standard deviations.
Confounder-Corrected T1 mapping in the Liver through Simultaneous Estimation of T1, PDFF, R2* and B1
Authors: Roberts Nathan , Tamada Daiki , Muslu Yavuz , Hernando Diego , Reeder Scott
Published: August 2023

T1 is emerging as a quantitative MR biomarker of liver fibrosis, the most important histological change predictive of progressing chronic liver disease. 3D spoiled gradient echo (SGRE)-based T1 mapping is preferable in the abdomen for its short acquisition time, volumetric coverage, and robustness to motion. However, SGRE-based T1 mapping is confounded by tissue fat and B1 inhomogeneity. In this work we present a novel SGRE-based T1 mapping method that corrects for both fat and B1 inhomogeneity. Phantom experiments show excellent agreement with reference T1 values (slope=1.01, R2=1.00) and minimal bias (~5±23ms). Early results from 5 healthy volunteers are promising.
A New Approach to Shimming Halbach Arrays Using Higher Order Halbach Array Inserts
Authors: O'Reilly Thomas , Teeuwisse Wouter , Webb Andrew
Published: August 2023

Halbach arrays are an appealing magnet design for low field MRI due to their low weight and cost typically suffer from relatively high B0 inhomogeneity. In this work we show a new approach to shimming Halbach arrays using higher order Halbach inserts which can be designed to target specific spherical harmonic terms. We demonstrate the principle by correcting for the x2-y2 spherical harmonic, improving B0 homogeneity of a 31cm diameter bore Halbach array by 50% and show that in simulations homogeneities of 280 ppm can be achieved over a 20 cm sphere by correcting up to 5th order spherical harmonics.
Temporal evolution of diffusion metrics in neonatal brains within the first few weeks postpartum
Authors: Bobba Pratheek , Weber Clara , Mak Adrian , Malhotra Ajay , Sheth Kevin , Taylor Sarah , Vossough Arastoo , Grant Patricia , Constable Todd , Ment Laura , Payabvash Seyedmehdi
Published: August 2023

In this retrospective cohort study, we characterized the age-related topography of quantitative diffusion metric evolution in 569 neonates scanned at our institution. We also studied the temporal rate of these metrics across different regions of the brain. and developed online interactive atlases depicting age-specific normative values of ADC and FA/MD in neonatal brains.
Perfusion territory shifts in asymptomatic carotid artery stenosis measured by super-selective arterial spin labelling
Authors: Hoffmann Gabriel , Reichert Miriam , Göttler Jens , Helle Michael , van de Ven Kim , Zimmer Claus , Petzsche Moritz Hernandez , Liebl Hans , Sollmann Nico , Preibisch Christine , Kaczmarz Stephan
Published: August 2023

Vessel-selective imaging is promising to examine collateral blood supply in asymptomatic internal carotid artery stenosis (ICAS). Established modalities like digital subtraction angiography are invasive, not quantitative and associated with potential complication risks. A viable non-invasive alternative is super-selective arterial spin labelling, providing perfusion territories of individual arteries. We present data from seven asymptomatic ICAS patients and four age-matched healthy controls. We compared individual perfusion territory maps to an atlas of vascular territories and evaluated intra-hemispheric differences, allowing for quantitative assessment of stenotic mal-perfusion as well as compensatory collateral blood supply from the contralateral ICA.
Measuring glomerular blood transfer rate in kidney using diffusion-weighted arterial spin labeling
Authors: Ahn Hyun-Seo , Park Sung-Hong
Published: August 2023

Imaging methods for the non-invasive measurement of renal function, such as glomerular filtration rate (GFR), are promising. In this study, we propose a renal perfusion kinetic model to estimate the blood transfer rate constant ($$$k_G$$$) in glomerulus with the multi-slice multi-delay diffusion-weighted arterial spin labeling sequence. Mean cortical $$$k_G$$$ values with a caffeine challenge were higher than those with no caffeine challenge, consistent with previous studies with GFR. The current study is promising in that it shows a potential availability of $$$k_G$$$ as a non-invasive quantitative measure of renal function.
Novel Self-calibrating 4D Flow-Field Signature Technique to Simultaneously Optimize Eddy Current Corrections and Detect Wraparound Errors
Authors: Nallamothu Thara , Berhane Haben , Ma Liliana , Baraboo Justin , Lee Daniel , Kim Daniel , Greenland Phillip , Markl Michael , Passman Rod , Elbaz Mohammed
Published: August 2023

Eddy current corrections are essential in preprocessing 4D flow data due to differing offset errors in each flow component leading to spatiotemporal inaccuracies in the velocity vector-field. Current automated optimization methods may require training data, have limited generalizability to different scan protocols, are sensitive to wraparound errors, and do not account for complex spatiotemporal errors. We introduce a self-calibrating method to optimize eddy current corrections and detect wraparound errors by using our recent 4D flow-field disparity signature technique that stochastically encodes the entire spatiotemporal profile of paired vector disparities and show feasibility and generalizability to two different 4D flow protocols.
Evaluation inflammatory and chronic structural sacroiliac joint changes in Axial Spondyloarthritis using semiquantitative MRI scoring system
Authors: zhang yimeng , guo zikang , lei xinwei
Published: August 2023

There are many clinical studies investigating the differences between non-radiographic axial spondyloarthritis and ankylosing spondylitis(AS), but few focus on radiology. Spondyloarthritis Research Consortium of Canada (SPARCC) and Sacroiliac Joint Structural Score (SSS) scoring systems can assess a broad spectrum of inflammatory and structural lesions. Our results indicate SPARCC scores were significantly improved after treatment. A significant increase in SSS scores for fat metaplasia and backfill was noted. Therefore, using semiquantitative MRI scoring methods can assess abnormal lesions and treatment response. Higher structural damages were seen in AS patients. SPARCC can assess severity of disease pre-treatment and treatment effectiveness.
Looking for a differential vulnerability of specific thalamic nuclei in multiple sclerosis
Authors: Blyau Simon , Koubiyr Ismail , Coupé Pierrick , Saranathan Manoj , Charré-Morin Julie , Saubusse Aurore , Prevost Valentin , Zhang Bei , Deloire Mathilde , Brochet Bruno , Ruet Aurélie , Tourdias Thomas
Published: August 2023

Thalamus is one of the first grey matter structure affected in multiple sclerosis (MS). It could undergo a differential vulnerability predominating on nuclei closer to the third ventricle due to pro-inflammatory factors brought by cerebrospinal fluid.First, we validated an atlas-based segmentation method that enables thalamic segmentation over conventional T1 weighted images. Then, using this segmentation method, we brought evidence for a medio-lateral gradient of thalamic atrophy in MS. While less affected, the anterior group was found useful to distinguish cognitively preserved from cognitively impaired patients. This paves the way toward more thalamic nuclei analyses in MS as new biomarkers.
Submillimeter dMRI protocol optimization for accurate in-vivo reconstruction of deep-brain circuitry
Authors: Maffei Chiara , Wang Fuyixue , Haber Suzanne , Yendiki Anastasia
Published: August 2023

The relatively low resolution of conventional in-vivo human dMRI prevents the reconstruction of small axonal bundles (diameter < 3mm). Here we show that diencephalic connections, which are inaccessible at macroscopic resolution (1.5mm), can be reconstructed with unprecedented accuracy at mesoscopic resolution (760μm). We investigate the minimum number of directions needed to achieve this with a state-of-the-art, multi-slab dMRI sequence. We find that a long, multi-session acquisition is necessary. We aim to develop a protocol for manual annotation of these bundles in a small number of high-quality datasets, and thus produce a training set for automated reconstruction in lower-quality dMRI data.
An unsupervised deep learning method for affine registration of multi-contrast brain MR images
Authors: Venkata Srivathsa Pasumarthi , Duffy Ben , Datta Keshav
Published: August 2023

Image registration is a crucial preprocessing step for many downstream analysis tasks. Existing iterative methods for affine registration are accurate but time consuming. We propose a deep learning (DL) based unsupervised affine registration algorithm that executes orders of magnitude faster when compared to conventional registration toolkits. The proposed algorithm aligns 3D volumes from the same modality (e.g. T1 vs T1-CE) as well as different modalities (e.g. T1 vs T2). We train the model and perform quantitative evaluation using a pre-registered brain MRI public dataset.
Learning to segment brain tumours using an explainable classifier
Authors: Chatterjee Soumick , Yassin Hadya , Dubost Florian , Nürnberger Andreas , Speck Oliver
Published: August 2023

Deep learning pipelines typically require manually annotated training data and the complex reasoning done by such methods make them appear as “black-boxes” to the end-users, leading to reduced trust. Unsupervised or weakly-supervised techniques could be a possible candidate for solving the first issue, while explainable classifiers or applying post-hoc interpretability-explainability methods on opaque classifiers may solve the second issue. This research addresses both problems by segmenting brain tumours without segmentation labels for training, using an explainable deep learning-based classifier. The classifier combined with a global pooling operation with a segmentation model to train and obtain classification results from this method.
StRegA: Unsupervised Anomaly Detection in Brain MRIs using Compact Context-encoding Variational Autoencoder
Authors: Chatterjee Soumick , Sciarra Alessandro , Dünnwald Max , Tummala Pavan , Agrawal Shubham , Jauhari Aishwarya , Kalra Aman , Oeltze-Jafra Steffen , Speck Oliver , Nürnberger Andreas
Published: August 2023

Deep learning methods are typically trained in a supervised with annotated data for analysing medical images with the motivation of detecting pathologies. In the absence of manually annotated training data, unsupervised anomaly detection can be one of the possible solutions. This work proposes StRegA, an unsupervised anomaly detection pipeline based on a compact ceVAE and shows its applicability in detecting anomalies such as tumours in brain MRIs. The proposed pipeline achieved a Dice score of 0.642±0.101 while detecting tumours in T2w images of the BraTS dataset and 0.859±0.112 while detecting artificially induced anomalies.
ViT-PU-Net: Volumetric Phase Unwrapping for MR images based on Vision Transformer
Authors: Jeon Soohyun , Ryu Kanghyun , Kim Dong-Hyun
Published: August 2023

MR phase information has been used in many MRI applications, recently, so it is very important to estimate the correct MR phase. Since the MR phase is encoded in complex exponential, the actual phase information obtained is in the form of a wrapped signal. Unfortunately, conventional MR phase unwrap methods are highly related to SNR and require a lot of computation, so an efficient method is needed.. Here, we propose ViT-PU-Net to perform 3D phase unwrap using ViT-based encoder architecture. Therefore, we investigated whether this architecture could be applied to 3D phase unwrap task by applying it to various data.
Further insight on T1 relaxation in fat-water mixtures
Authors: Fortier Véronique , Levesque Ives
Published: August 2023

The impact of the fat fraction in fat-water mixtures on the fat and water T1s is an open question, with variable observations reported in phantoms, in vivo in bone marrow, and in liver. This work investigated variations of fat and water T1 as a function of fat content in phantoms in the presence of a water relaxation enhancing agent (MnCl2). Fat fraction and MnCl2 impacted both the water and fat T1s, in different ways. Our observations may shed light on variable trends of fat and water T1 as a function of fat content reported in the literature.
Is the intra-axonal T2 relaxation time related to the axonal calibre? A diffusion-relaxation and histological data study
Authors: Barakovic Muhamed , Pizzolato Marco , Granziera Cristina , Thiran Jean-Philippe , Jones Derek , Canales-Rodríguez Erick
Published: August 2023

The main limitation of current axon diameter mapping techniques is that the diffusion MRI (dMRI) signals from axons smaller than 2.0 μm are practically undistinguished from each other, even for the most advanced human scanners. Consequently, there is a resolution limit for the in vivo estimation of axon diameters from dMRI data. Therefore, it would be desirable to find another source of MRI contrast sensitive to the axonal calibre. This proof-of-concept study used a surface-based relaxation model to investigate whether the intra-axonal T2 estimated in a human brain is related to the inner axon radius measured from histological data.
Low field NMR Relaxometry Studies of Tumours with applications in Intraoperative Tumour Margin Assessment in Breast-Conserving Surgery
Authors: Baroni Simona , Bitonto Valeria , Ruggiero Maria , Pittaro Alessandra , Castellano isabella , Bussone Riccardo , Broche Lionel , Lurie David , Aime Silvio , Crich Simonetta Geninatti
Published: August 2023

A new methodology, based on low field NMR relaxometry, has been employed to characterize breast tumour tissue and to tackle the important clinical need for the assessment of tumour margins during breast-conserving surgery. The method relies on the acquisition of proton longitudinal relaxation rate at low magnetic field strengths which are affected by the changes in the composition of the mammary gland tissue occurring during the development of neoplasia. A sensitivity, specificity, and accuracy of 92%, 85%, and 89%, respectively, were achieved. The information obtained has the potential to support the surgeon in real-time margin assessment.
Hierarchical multi-resolution graph-cuts for water–fat–silicone separation in breast MRI
Authors: Stelter Jonathan , Boehm Christof , Ruschke Stefan , Weiss Kilian , Diefenbach Maximilian , Wu Mingming , Borde Tabea , Makowski Marcus , Fallenberg Eva , Karampinos Dimitrios
Published: August 2023

A water- and fat-suppressed sequence is typically used to verify the integrity of silicone breast implants. The feasibility of using chemical shift encoding-based MRI for in vivo water–fat–silicone separation was recently shown. In this work, a hierarchical multi-resolution graph-cut framework is developed and proposed for water–fat–silicone separation in breast MRI. Robustness and competitive processing times are achieved by performing graph-cuts using varying spatial resolution. Results show successful water–fat–silicone separation for 4 echoes (the minimum of required echoes) without water–fat–silicone swaps and an improved silicone contrast compared to the conventional sequence.
ModFlex – a modular system of flexible receive-only coil arrays for 3 T MRI
Authors: Nohava Lena , Obermann Michael , Frass-Kriegl Roberta , Roat Sigrun , Soanca Onisim , Weber Nicolas , Ginefri Jean-Christophe , Felblinger Jacques , Laistler Elmar
Published: August 2023

Flexible form-fitting radiofrequency coils provide high signal-to-noise ratio during MRI, and in array configuration large anatomical areas of interest can be covered. We propose a modular system - “ModFlex”- of flexible lightweight 4-channel coaxial coil arrays for 3T MRI. We investigated the performance difference between commercial reference coils and 8- and 16-channel ModFlex receive-only array systems. The versatility of ModFlex, the robustness of the coil characteristics for different use cases and a signal-to-noise gain compared to reference coils is demonstrated.
Transmit Performance of a Metamaterial Slab as a Passive RF Shimming Element for 3T MRI
Authors: Rémillard Léo , Maunder Adam , Iyer Ashwin , De Zanche Nicola
Published: August 2023

At higher static magnetic field strengths (3T) characteristic regions of low transmit fields occur that degrade the quality and diagnostic efficacy of MRI. Here we present the design, simulation, and measurement of thin (2cm), lightweight metamaterial (MTM) slabs for 3T that manipulate the field produced by a birdcage (BC) volume resonator for improved transmit performance. In a torso-sized phantom, a measured 39% increase in the mean flip angle and 4.9% reduction in the percent coefficient of variation was found, while the specific absorption rate normalized to the mean transmit field was reduced by 32%.
Longitudinal associations between 4D flow MRI intracranial pulsatility, white matter lesions, and perivascular space dilation across 5 years
Authors: Vikner Tomas , Karalija Nina , Eklund Anders , Malm Jan , Nyberg Lars , Wåhlin Anders
Published: August 2023

Small vessel disease (SVD) is associated with elevated vascular stiffness and pulsatility, but longitudinal studies are lacking. Using a 4D flow MRI approach sensitive to age-differences in pulsatility in large and small cerebral arteries, we evaluated 5-year changes in pulsatility in relation to changes in white matter lesions (WML) and perivascular spaces (PVS), radiological markers of SVD. Pulsatility change correlated with WML and PVS volume change, but pulsatility at baseline did not predict WML and PVS progression. However, WML and PVS volumes at baseline predicted 5-year pulsatility change, suggesting that microvascular dysfunction associated with SVD accelerates pulsatility increases.
Real-time 3D MRI for Low-Latency Volumetric Motion Tracking on a 1.5T MR-Linac System
Authors: Wu Can , Tyagi Neelam , Reyngold Marsha , Crane Christopher , Otazo Ricardo
Published: August 2023

Real-time 3D MRI for low-latency volumetric motion tracking was successfully implemented on a 1.5T MR-Linac system using the MRSIGMA framework. A first scan was performed for offline learning to obtain a training dictionary of ten 3D motion states. A second scan with the same sequence parameters was performed to generate the motion signature in real-time for online matching and was also used as a reference for retrospective self-validation. The feasibility of the technique was demonstrated on a healthy volunteer and a patient with pancreatic cancer which presented high quantitative concordance between contours of real-time MRSIGMA matching and the reference.
Field-Map Combination Method for Phase-Cycled bSSFP using Inherent Bo Mapping
Authors: Datta Anjali , Nishimura Dwight , Baron Corey
Published: August 2023

Phase-cycled bSSFP enables off-resonance-robust bSSFP imaging. Conventional phase-cycle combination methods weight brighter phase-cycles more, assuming that passband signal is brighter than off-resonant signal. However, near-band signal can be hyperintense, most notably for flowing spins, so traditional methods fail to mitigate these artifacts. Incorporating knowledge of Bo enables inclusion of only passband signal, and exclusion of dark bands and near-band hyperintense artifacts. Using a golden-angle radial trajectory for a free-breathing, phase-cycled acquisition enables reconstruction of a Bo-map time series without any additional scans. This facilitates field-map-based combination throughout the respiratory and cardiac cycles, resulting in substantially reduced hyperintense artifacts than root-sum-of-squares.
Imaging eddy currents induced by crusher gradients using SPEEDI with sub-millisecond temporal resolution
Authors: Scotti Alessandro , Zhong Zheng , Zhou Xiaohong Joe
Published: August 2023

Crusher gradients, typically having very high amplitude, can induce a substantial amount of eddy currents, causing various artifacts. In order to fully characterize the spatiotemporal characteristics of the currents, we have developed a spin echo version of the previously reported SPEEDI technique. The method consists of a series of spin echo acquisitions where each echo point is assigned to a different k-space, reaching a temporal resolution equal to the dwell time. The measured phase difference between sequences with positive and negative crushers revealed B0 and linear eddy currents with time constants equal to the ones measured by the manufacturer’s tool.
Autonomic Function Regulates the Default-Mode Network in Rats
Authors: Cao Jiayue , Wang Xiaokai , Liu Zhongming
Published: August 2023

The default mode network (DMN) is central to cognition. Consistent across species, functional connectivity (FC) of DMN exhibits partly similar patterns across brain states, including wakefulness, sleep, sedated or anesthetized states. Regions in DMN are also involved in regulating visceral organs. It is likely that DMN facilitates visceral physiology to maintain homeostasis in states of unconsciousness. However, the evidence for the association between autonomic function and DMN is sparse and piecemeal. Here, we use fMRI in rat models to investigate how vagal nerve de-innervation and stimulation affect the DMN and its interaction with other regions related to autonomic function.
Glucose versus fructose metabolism in the liver measured with deuterium metabolic imaging
Authors: Hendriks Arjan , Veltien Andor , Voogt Ingmar , Heerschap Arend , Scheenen Tom , Prompers Jeanine
Published: August 2023

The worldwide increase in sugar consumption is a major health concern. The contribution of fructose to the epidemic of metabolic disorders is controversial. This study investigated differences between glucose and fructose metabolism in the liver using dynamic deuterium metabolic imaging (DMI). Deuterium signal time curves after bolus injection and slow infusion were successfully acquired and showed different patterns. It was found that the peak concentration and conversion of deuterated glucose was different from that of fructose, indicating faster turnover of the latter. Overall, these methods could potentially lead to better understanding of healthy liver metabolism and aberrations in metabolic diseases.
Development of perfusion technique with dynamic BOLD MRI and transient hypoxia in mouse
Authors: LE THI THUY , LEE DONG KYU , IM GEUN HO , KIM SEONG GI
Published: August 2023

Tissue perfusion can be measured by arterial spin labeling and dynamic susceptibility contrast (DSC) method. However, these methods cannot be easily applied to mouse. Alternatively, a bolus of paramagnetic deoxyhemoglobin induced by transient hypoxia may be used as an endogenous blood pool contrast agent. Dynamic BOLD MRI with hypoxic challenge was adopted in mice. A stimulus duration was determined, and its impact to animal physiology was investigated. With corrected arterial input function, quantitative CBF and CBV were determined. Overall, we successfully developed a technique with BOLD MRI and transient hypoxia.
Combined Angiographic, Structural and Perfusion Radial Imaging using Arterial Spin Labeling
Authors: Okell Thomas , Woods Joseph , Chiew Mark
Published: August 2023

A Combined Angiographic, Structural and Perfusion Radial Imaging using Arterial Spin Labeling (CASPRIA) pulse sequence is presented which allows the simultaneous acquisition of non-contrast dynamic angiograms, quantitative perfusion maps and multi-contrast T1-weighted structural images within a single six-minute scan. Compared to conventional imaging methods, which took 70% longer to acquire, CASPRIA yielded comparable quantitative perfusion estimates, dynamic (rather than static) angiography with improved distal vessel visibility and structural images with greater contrast flexibility. With further work, the estimation of quantitative tissue T1 values could also be possible.
Mapping the inversion efficiency (finv): Comparison between adiabatic pulses for use in MP2RAGE-based T1-mapping
Authors: Olsson Hampus , Helms Gunther
Published: August 2023

Accuracy in MP2RAGE-based T1-mapping relies on knowledge of the imperfect inversion efficiency (finv) of the inversion pulse. Here we map the inversion efficiency of different adiabatic inversion pulses in human brain at 7T. We identified a mean finv=0.87, which is substantially lower than the finv=0.96 typically assumed in MP2RAGE. We further observed a lower finv in white matter (WM) than in the rest of the cerebrum. Subsequent T1 estimates differed by approximately 80 ms in WM and 200 ms in gray matter (GM) when assuming either finv=0.87 or finv=0.96.
ReImagining the Young Adult Human Connectome Project (HCP) Diffusion MRI Dataset
Authors: Irfanoglu M. Okan , Beyh Ahmad , Catani Marco , Dell'Acqua Flavio , Pierpaoli Carlo
Published: August 2023

The Human Connectome Project (HCP) has brought significant advancements in hardware, acquisition, and preprocessing. Even after a decade since its collection, the HCP diffusion MRI data is still relevant for its richness and high resolution. Noise and geometric distortions, however, are particularly pronounced in this dataset. In this work, we have reprocessed nearly the entire HCP dMRI dataset while applying several recent processing improvements. We compared the quality of the newly processed dMRI outputs to the release version. We observed clearly detectable improvements. The data originated from this new processing will be made publicly available.
Dose-dependent effects of S-ketamine on frontal neurometabolism: a 7T functional MRS study
Authors: Boucherie Daphne , van Mil Sean , Reneman Liesbeth , Hollmann Markus , Schrantee Anouk
Published: August 2023

The therapeutic antidepressant effect of S-ketamine has been linked to changes in glutamatergic neurotransmission. Here, we investigated the value of dynamic functional MRS compared to static MRS in detecting dose-dependent effects of subanesthetic S-ketamine on glutamate in the anterior cingulate cortex. Although significant dose-dependent subjective dissociative effects of S-ketamine were observed, we did not find significantly different glutamate changes between placebo, low-dose S-ketamine and high-dose S-ketamine, using either a “static” or “dynamic” analysis approach. Nevertheless, exploratory analyses suggest that glutamate might be modulated at specific time-points after S-ketamine administration, illustrating the potential additional information obtained from a dynamic approach.
Volumetric T2-Weighted Spin-Echo MRI with Improved SNR Using Localized Quadratic Encoding
Authors: Kim Dahan , Wang Dinghui , Chao Tzucheng , Pipe James
Published: August 2023

T2-weighted imaging typically employs either TSE or multi-pass 2D SE acquisitions, but using a thick slice and/or a slice gap is often necessary to overcome SNR inefficiencies of these methods, to achieve high-resolution scans in reasonable scan time. We studied efficient T2-weighted SE technique which employed localized quadratic encoding to realize SNR-efficient slice encoding scheme that produced contiguous volumetric coverage. Combined with long-readout spiral acquisitions, the proposed method, a hybrid of 2D and 3D imaging, demonstrated the expected SNR benefit compared to standard 2D scans and produced T2-weighted images with SNR equivalent as 2D-TSE scans but with larger, contiguous coverage.