Article
Radiology, Nuclear Medicine & Medical Imaging
Muhammad A. R. Anjum, Felix M. Gonzalez, Anshuman Swain, Johannes Leisen, Zahra Hosseini, Adam Singer, Monica Umpierrez, David A. Reiter
Summary: The study demonstrates the use of multi-component relaxation modeling for quantitative analysis of human Achilles tendon, showing that the multi-component model provides a higher quality of fit with slightly increased estimate variance compared to the bi-component model. Bi-component estimates exhibit notable bias, particularly in the presence of off-resonance components.
MAGNETIC RESONANCE IN MEDICINE
(2021)
Article
Radiology, Nuclear Medicine & Medical Imaging
Muhammad A. R. Anjum, Felix M. Gonzalez, Anshuman Swain, Johannes Leisen, Zahra Hosseini, Adam Singer, Monica Umpierrez, David A. Reiter
Summary: Multi-component relaxation modelling was used for quantitative analysis of human Achilles tendon, showing superior fit quality compared to the bi-component model with a slight increase in estimate variance. Bias errors were notable in bi-component estimates, particularly in the presence of off-resonance components.
MAGNETIC RESONANCE IN MEDICINE
(2021)
Article
Chemistry, Analytical
Dongxia Chen, Yaying Lin, Ao Li, Xiangjie Luo, Chaoyong Yang, Jinhao Gao, Hongyu Lin
Summary: This study presents a strategy called bio-orthogonal metabolic fluorine labeling for selective cellular F-19 labeling, enabling high specific imaging of tumor cells in vivo. The strategy involves the display of azido groups on the cell surface and subsequent bio-orthogonal ligation to incorporate F-19-containing moieties on the cancer cell surface. The feasibility of this method was validated on the cellular level and further demonstrated for in vivo deep-tissue visualization of cancer cells using F-19 MRI.
ANALYTICAL CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Jose Borreguero, Fernando Galve, Jose M. Algarin, Jose M. Benlloch, Joseba Alonso
Summary: Magnetic Resonance Imaging of hard biological tissues is challenging, especially at low magnetic fields. Different pulse sequences have been developed, but only Zero Echo Time (ZTE) and SWeep Imaging with Fourier Transformation (SWIFT) have potential for imaging tissues with ultra-short T-2 times at low fields. This study demonstrates the versatile use of spin-locking for slice selection and presents three combinations with ZTE imaging for 2D ex vivo imaging of hard tissues at low field.
SCIENTIFIC REPORTS
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Kohei Hamamoto, Emiko Chiba, Noriko Oyama-Manabe, Hironao Yuzawa, Hiroshi Shinmoto
Summary: This study evaluated the diagnostic performance of ultra-short echo time magnetic resonance imaging (UTE MRI) in the assessment of pulmonary arteriovenous malformation (PAVM). The results showed that UTE MRI had high sensitivity and specificity for the detection and classification of PAVMs, and had good consistency with CT.
EUROPEAN JOURNAL OF RADIOLOGY
(2022)
Article
Multidisciplinary Sciences
Jose Borreguero, Fernando Galve, Jose M. Algarin, Jose M. Benlloch, Joseba Alonso
Summary: Magnetic Resonance Imaging (MRI) of hard biological tissues is challenging due to the weak magnetization at low magnetic fields. This study introduces pulse sequences to overcome the issue of ultra-short lived MR signals and demonstrates the versatility of spin-locking for slice selection. The researchers successfully performed slice-selected imaging of the hardest tissues in the body at low field using this method.
SCIENTIFIC REPORTS
(2023)
Article
Computer Science, Artificial Intelligence
Fumin Guo, Dante Pi Capaldi, David G. McCormack, Aaron Fenster, Grace Parraga
Summary: The study developed a lung segmentation method using CKKM algorithm combined with U-net and atlas-based approaches, which improved the accuracy and precision of imaging pulmonary structural abnormalities.
MEDICAL IMAGE ANALYSIS
(2021)
Article
Radiology, Nuclear Medicine & Medical Imaging
Eva Deininger-Czermak, Dominic Gascho, Sabine Franckenberg, Pascal Kalin, Christian Bluthgen, Christina Villefort, Michael J. Thali, Roman Guggenberger
Summary: This study evaluated the added value of ultra-short echo time (UTE) and fast field echo resembling a CT using restricted echo-spacing (FRACTURE) MR sequences in the assessment of the osseous cervical spine. The results showed that compared to CT, the combination of UTE or FRACTURE sequences with standard MR sequences can provide comparable information on the cervical spine status, and can change the clinically significant stenosis grading.
Article
Neurosciences
Louise Ebersberger, Fabian J. Kratzer, Arne Potreck, Sebastian C. Niesporek, Myriam Keymling, Armin M. Nagel, Martin Bendszus, Wolfgang Wick, Mark E. Ladd, Heinz-Peter Schlemmer, Angelika Hoffmann, Tanja Platt, Daniel Paech
Summary: Dynamic O-17 MRI is a direct and non-invasive imaging method for assessing cerebral oxygen metabolism. This study applied dynamic O-17 MRI for the first time at 7 Tesla in a stroke patient, demonstrating its technical feasibility. The analysis did not show a significant difference in the O-17 water signal between the affected stroke region and the healthy side, but it opens possibilities for future investigations on neurovascular diseases.
FRONTIERS IN NEUROSCIENCE
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Noah B. Bonnheim, Linshanshan Wang, Ann A. Lazar, Ravi Chachad, Jiamin Zhou, Xiaojie Guo, Conor O'Neill, Joel Castellanos, Jiang Du, Hyungseok Jang, Roland Krug, Aaron J. Fields
Summary: This study aims to develop an objective, accurate, and efficient method for calculating biomarkers of spinal cartilage endplate (CEP) health using deep learning. Through segmentation and comparison of multiple images, the results show that the model can accurately and automatically segment CEP and calculate its T2* values, and can classify and diagnose patients in a clinical setting.
QUANTITATIVE IMAGING IN MEDICINE AND SURGERY
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Arka Das, Christopher Kelly, Irvin Teh, Christian T. Stoeck, Sebastian Kozerke, Amrit Chowdhary, Louise A. E. Brown, Christopher E. D. Saunderson, Thomas P. Craven, Pei G. Chew, Nicholas Jex, Peter P. Swoboda, Eylem Levelt, John P. Greenwood, Jurgen E. Schneider, Sven Plein, Erica Dall'Armellina
Summary: Cardiac diffusion tensor imaging (cDTI) can be used to assess microstructural changes in the myocardium after ST-segment elevation myocardial infarction. This study found that acute infarcted myocardium had reduced fractional anisotropy, secondary eigenvector angle, and myocytes with right-handed orientation, which were correlated with long-term left ventricular remodeling. The results suggest the potential clinical utility of cDTI in predicting long-term outcomes after myocardial infarction.
Article
Radiology, Nuclear Medicine & Medical Imaging
Xin Shen, Ali Caglar Ozen, Antonia Sunjar, Serhat Ilbey, Stephen Sawiak, Riyi Shi, Mark Chiew, Uzay Emir
Summary: This study aimed to develop a new 3D dual-echo rosette k-space trajectory for UTE MRI applications, which showed better performance compared to a 3D radial UTE acquisition. The imaging of the uT(2) of brain demonstrated the ability of the proposed sequence to capture rapidly decaying signals.
MAGNETIC RESONANCE IN MEDICINE
(2023)
Article
Multidisciplinary Sciences
Vanessa Franziska Schmidt, Federica Arnone, Olaf Dietrich, Max Seidensticker, Marco Armbruster, Jens Ricke, Philipp Maximilian Kazmierczak
Summary: The size of needle artifact in MRI-guided abdominal interventions gradually increases with higher flip angles and intervention angles, while the matrix size chosen also affects the artifact size. High interrater reliability was observed during the study. To minimize needle artifacts while maintaining optimal visibility, medium-range flip angles and low intervention angles are recommended.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Dongxia Chen, Junnan Guo, Ao Li, Chengjie Sun, Huibin Lin, Hongyu Lin, Chaoyong Yang, Wei Wang, Jinhao Gao
Summary: In this study, a metabolic fluorine labeling (MEFLA)-based strategy using 19F MRI is proposed for monitoring the dynamic gut microbiota. Different microbiota subgroups are labeled in situ using a panel of peptidoglycan-targeting MEFLA probes with 19F atoms of different chemical shifts. Real-time in vivo imaging is then achieved using multiplexed hotspot 19F MRI. The strategy allows for extended visualization and semiquantitative analysis of the metabolic dynamics of gut microbiota located at different intestinal sections.
Article
Neurosciences
Hanwen Liu, Vladimir Grouza, Marius Tuznik, Katherine A. Siminovitch, Hooman Bagheri, Alan Peterson, David A. Rudko
Summary: In this study, a novel unsupervised learning method called self-labelled encoder-decoder (SLED) was developed to improve gradient echo-based myelin water imaging (MWI) data fitting. By collecting MWI data from mouse brains and evaluating the performance using a simulated MWI phantom, the results showed that SLED exhibited improved stability and accuracy compared to the non-linear least squares fitting (NLLS) approach and produced less noisy MWI maps.
Article
Radiology, Nuclear Medicine & Medical Imaging
Agazi Samuel Tesfai, Andreas Vollmer, Ali Caglar Ozen, Moritz Braig, Wiebke Semper-Hogg, Markus Jorg Altenburger, Ute Ludwig, Michael Bock
Summary: Accurate visualization of dental root canals is crucial for proper diagnosis and treatment. This study demonstrates the improvement of a new dental MRI coil in terms of signal-to-noise ratio and visibility. The results show that the intraoral flexible coil provides better image quality and visibility compared to conventional coils.
INVESTIGATIVE RADIOLOGY
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Fritz M. Bayer, Michael Bock, Peter Jezzard, Alex K. Smith
Summary: The original qMT balanced steady-state free precession (bSSFP) model is biased due to over-simplistic assumptions. An improved model incorporating finite RF pulse effects and simultaneous exchange and relaxation outperforms the original one in numerical simulations and previously acquired in vivo data. This new model is recommended for accurate qMT parameter mapping in healthy and diseased brain tissue structures.
MAGNETIC RESONANCE IN MEDICINE
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Johannes Fischer, Ali Caglar Oezen, Serhat Ilbey, Louisa Traser, Matthias Echternach, Bernhard Richter, Michael Bock
Summary: The study introduces a new fast MRI acquisition method, SPIRE, for encoding rapid two-dimensional motion of human vocal folds with sub-millisecond resolution. The technique successfully demonstrates dynamic images of vocal fold oscillations in the coronal plane, providing valuable insights for imaging rapidly oscillating structures.
MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Serhat Ilbey, Pia M. Jungmann, Johannes Fischer, Matthias Jung, Michael Bock, Ali Caglar Oezen
Summary: This study aimed to accelerate the Pointwise Encoding Time Reduction with Radial Acquisition (PETRA) sequence using compressed sensing while preserving the image quality for high-resolution MRI of tissues with ultra-short T2* values. The results showed that even at high acceleration factors, no aliasing artifacts were observed, and the anatomical details were preserved compared to fully sampled data. The csPETRA allowed for ultra-short T2* imaging of the knee joint in clinically acceptable scan times while maintaining the image quality of the original non-accelerated PETRA sequence.
MAGNETIC RESONANCE IN MEDICINE
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Ali Caglar Oezen, Felix Spreter, Waldemar Schimpf, Johannes Fischer, Serhat Ilbey, Simon Reiss, Alexander Maier, Dominik von Elverfeldt, Timo Heidt, Constantin von zur Muehlen, Michael Bock
Summary: This study presents an RF coil system with 8-channel transmit and 8-channel receive coil arrays for F-19 MRI of large animals. The Tx efficiency and homogeneity of the 8-element loop coil array were evaluated using simulated pig models. An 8-channel Rx coil array consisting of a flexible 6-channel posterior and a 2-channel planar anterior array was designed and validated through measurements in a grid phantom and ex vivo on a pig model with PFOB-filled tubes inserted in the thorax.
MAGNETIC RESONANCE IN MEDICINE
(2023)
Article
Chemistry, Multidisciplinary
Hamidreza Saeidi, Morteza Mozaffari, Serhat Ilbey, Silvio Dutz, Diana Zahn, Gholamhassan Azimi, Michael Bock
Summary: This work provides a detailed description of the synthesis and characterizations of europium-substituted Mn-Zn ferrite magnetic nanoparticles. The europium substitution significantly affects the crystallite size, saturation magnetization, and relaxivity. The results show that the europium-substituted nanoparticles have potential as dual-mode MRI contrast agents with enhanced contrast and improved biocompatibility.
Article
Chemistry, Physical
Andreas B. Schmidt, James Eills, Laurynas Dagys, Martin Gierse, Michael Bock, Sebastian Lucas, Michael Bock, Ilai Schwartz, Maxim Zaitsev, Eduard Y. Chekmenev, Stephan Knecht
Summary: Efficient and rapid pyruvate hyperpolarization is achieved through signal amplification by reversible exchange (SABRE) with parahydrogen. This approach allows for high levels of polarization and paves the way for future in vivo translation of carbon-13 hyperpolarized molecular imaging probes.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Ali Caglar Oezen, Serhat Ilbey, Feng Jia, Djaudat Idiyatullin, Michael Garwood, Donald R. Nixdorf, Michael Bock
Summary: The purpose of this study was to improve the design of transverse intraoral loop coil for high-resolution dental MRI. The modified coil showed increased sensitivity, improved image SNR, and reduced unwanted signals and eddy currents. The proposed new coil provided higher SNR at specific regions of interest and improved patient comfort.
MAGNETIC RESONANCE IN MEDICINE
(2023)
Review
Radiology, Nuclear Medicine & Medical Imaging
Adrienne E. Campbell-Washburn, Kathryn E. Keenan, Peng Hu, John P. Mugler, Krishna S. Nayak, Andrew G. Webb, Johnes Obungoloch, Kevin N. Sheth, Juergen Hennig, Matthew S. Rosen, Najat Salameh, Daniel K. Sodickson, Joel M. Stein, Jose P. Marques, Orlando P. Simonetti
Summary: The first ISMRM Workshop on Low-Field MRI was held virtually in March 2022, discussing recent advancements in low field MRI technology and its clinical applications. With 368 registrants from 24 countries, the workshop included invited talks, abstract presentations, panel discussions, and live scanner demonstrations. The workshop emphasized the potential of low-field MRI in expanding MRI usage through cost reduction, portability, and ease of installation, as well as the challenges in overcoming SNR limitations and establishing clinical value.
MAGNETIC RESONANCE IN MEDICINE
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Samantha Hickey, Andreas Reichert, Wolfgang Ptacek, Lars Bielak, Simon Reiss, Johannes Fischer, Deepa Darshini Gunashekar, Thomas Bortfeld, Michael Bock
Summary: The purpose of this study was to design a fast T2-weighted sequence capable of simultaneously acquiring two orthogonal slices, enabling real-time tracking of lesions. By swapping the slice selection and phase-encoding directions, the researchers successfully identified and delineated the lesions in the dynamic images. This sequence allows for simultaneous acquisition, which could be beneficial for real-time motion tracking in radiotherapy or interventional MRI.
MAGNETIC RESONANCE IN MEDICINE
(2023)
Review
Radiology, Nuclear Medicine & Medical Imaging
Mark E. Ladd, Harald H. Quick, Oliver Speck, Michael Bock, Arnd Doerfler, Michael Forsting, Juergen Hennig, Bernd Ittermann, Harald E. Moeller, Armin M. Nagel, Thoralf Niendorf, Stefan Remy, Tobias Schaeffter, Klaus Scheffler, Heinz-Peter Schlemmer, Sebastian Schmitter, Laura Schreiber, N. Jon Shah, Tony Stoecker, Michael Uder, Arno Villringer, Nikolaus Weiskopf, Moritz Zaiss, Maxim Zaitsev
Summary: Multiple sites in Germany operate human MRI systems at 7 Tesla or 9.4 Tesla. The German Ultrahigh Field Imaging (GUFI) network was established in 2013 to facilitate research cooperation and make this technology available to a larger community of researchers and clinicians worldwide. This paper summarizes the history, current status, motivation, and challenges of pursuing MRI at higher magnetic field strengths, focusing on the perspective in Germany.
MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE
(2023)
Review
Radiology, Nuclear Medicine & Medical Imaging
Juergen Hennig
Summary: The paper details the evolution of low-field MRI from its inception to present day, focusing on the differences in research environments. In the early 90s, the lack of reasonable means to compensate for the difference in signal-to-noise ratio between 0.5 and 1.5 T resulted in the disappearance of low-field systems. However, advancements in hardware, RF receiver systems, faster gradients, flexible sampling schemes, and the integration of AI have made low-field MRI a clinically viable supplement. Additionally, ultralow-field MRI with magnets around 0.05 T has emerged as an endeavor to bring MRI to underserved communities.
MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Ali Caglar Oezen, Maximilian Frederik Russe, Thomas Lottner, Simon Reiss, Sebastian Littin, Maxim Zaitsev, Michael Bock
Summary: This study evaluates the RF-induced heating of commonly used intravascular devices in a low-field MRI system (0.55 T) at the Larmor frequency. The results show that liver catheterizations have the lowest RF heating, and modifying the transmit body coil design can further reduce the temperature increase.
MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE
(2023)
Article
Urology & Nephrology
Robert Wriedt, Mehmet Yilmaz, Thomas Lottner, Andreas Reichert, Konrad Wilhelm, Philippe-Fabian Pohlmann, Christian Gratzke, Michael Bock, Arkadiusz Miernik
Summary: In this study, we evaluated critical temperature areas in the kidney parenchyma using magnetic resonance thermometry in an ex vivo Holmium:YAG laser lithotripsy model. The results showed that high laser power and longer application times, low irrigation rate, and anatomical volume of the targeted calyx were closely associated with critical temperature areas in the kidney parenchyma.
WORLD JOURNAL OF UROLOGY
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Anneloes de Boer, Giulia Villa, Octavia Bane, Michael Bock, Eleanor F. Cox, Ilona A. Dekkers, Per Eckerbom, Maria A. Fernandez-Seara, Susan T. Francis, Bryan Haddock, Michael E. Hall, Pauline Hall Barrientos, Ingo Hermann, Paul D. Hockings, Hildo J. Lamb, Christoffer Laustsen, Ruth P. Lim, David M. Morris, Steffen Ringgaard, Suraj D. Serai, Kanishka Sharma, Steven Sourbron, Yasuo Takehara, Andrew L. Wentland, Marcos Wolf, Frank G. Zollner, Fabio Nery, Anna Caroli
Summary: Through a systematic consensus process, technical recommendations were established for the acquisition, processing, and analysis of renal 2D PC-MRI data in human subjects to promote standardization of renal blood flow measurements and result comparability. The international panel of experts reached consensus and provided specific recommendations on data acquisition, processing, and reporting. These recommendations may encourage widespread adoption of renal PC-MRI and provide reference values for multicenter studies.
JOURNAL OF MAGNETIC RESONANCE IMAGING
(2022)
