Journals Magnetic Resonance in Medical ...

Magnetic Resonance in Medical Sciences : MRMS
Ryoichi Kose, Katsumi Kose, Koji Fujimoto, Tomohisa Okada, Daiki Tamada, Utaroh Motosugi
Recent high-performance gradient coils are fabricated mainly at the expense of spatial linearity. In this study, we measured the spatial nonlinearity of the magnetic field generated by the gradient coils of two MRI systems with high-performance gradient coils. The nonlinearity of the gradient fields was measured using 3D gradient echo sequences and a spherical phantom with a built-in lattice structure. The spatial variation of the gradient field was approximated to the 3rd order polynomials. The coefficients of the polynomials were calculated using the steepest descent method...
September 9, 2023: Magnetic Resonance in Medical Sciences: MRMS
Zuofeng Zheng, Yawen Liu, Hongxia Yin, Pengling Ren, Tingting Zhang, Jiafei Yang, Zhenchang Wang
Synthetic MRI is being increasingly used for the quantification of brain longitudinal relaxation time (T1), transverse relaxation time (T2), and proton density (PD) values. However, the effect of fast imaging protocols on these quantitative values has not been fully estimated. The purpose of this study was to investigate the effect of fast scan parameters on T1, T2, and PD measured with a multi-dynamic multi-echo (MDME) sequence of normal brain at 3.0T. Thirty-four volunteers were scanned using 3 MDME sequences with different scan times (named Fast, 2 min, 29 sec; Routine, 4 min, 07 sec; and Research, 7 min, 46 sec, respectively)...
September 8, 2023: Magnetic Resonance in Medical Sciences: MRMS
Yuta Endo, Sanae Takahashi, Haruna Shibo, Makoto Amanuma, Kuninori Kobayashi, Shigehide Kuhara
PURPOSE: Polarity-corrected inversion time preparation (PCTIP), a myocardial T1 mapping technique, is expected to reduce measurement underestimation in the modified Look-Locker inversion recover method. However, measurement precision is reduced, especially for heart rate variability. We devised an analysis using a recurrence formula to overcome this problem and showed that it improved the measurement accuracy, especially at high heart rates. Therefore, this study aimed to determine the effect of this analysis on the accuracy and precision of T1 measurements for irregular heart rate variability...
September 4, 2023: Magnetic Resonance in Medical Sciences: MRMS
Daisuke Takenaka, Yoshiyuki Ozawa, Kaori Yamamoto, Maiko Shinohara, Masato Ikedo, Masao Yui, Yuka Oshima, Nayu Hamabuchi, Hiroyuki Nagata, Takahiro Ueda, Hirotaka Ikeda, Akiyoshi Iwase, Takeshi Yoshikawa, Hiroshi Toyama, Yoshiharu Ohno
PURPOSE: Deep learning reconstruction (DLR) has been recommended as useful for improving image quality. Moreover, compressed sensing (CS) or DLR has been proposed as useful for improving temporal resolution and image quality on MR sequences in different body fields. However, there have been no reports regarding the utility of DLR for image quality and T-factor assessment improvements on T2-weighted imaging (T2WI), short inversion time (TI) inversion recovery (STIR) imaging, and unenhanced- and contrast-enhanced (CE) 3D fast spoiled gradient echo (GRE) imaging with and without CS in comparison with thin-section multidetector-row CT (MDCT) for non-small cell lung cancer (NSCLC) patients...
September 1, 2023: Magnetic Resonance in Medical Sciences: MRMS
Barış Genç, Kerim Aslan, Ali Özçağlayan, Lütfi İncesu
PURPOSE: Glioblastoma patients develop recurrence in the opposite hemisphere far from the primary tumor site even after complete resection. This is one of the main reasons for short disease survival. Our aim in this study is to detect microstructural changes in the contralateral hemisphere of glioblastoma patients using different diffusion models with the fully automated tract-based spatial statistics (TBSS) method. METHODS: Fourteen right-sided and eleven left-sided glioblastoma patients without any treatment and eighteen age- and gender-matched controls were included in the study...
August 1, 2023: Magnetic Resonance in Medical Sciences: MRMS
Noriyuki Fujima, Koji Kamagata, Daiju Ueda, Shohei Fujita, Yasutaka Fushimi, Masahiro Yanagawa, Rintaro Ito, Takahiro Tsuboyama, Mariko Kawamura, Takeshi Nakaura, Akira Yamada, Taiki Nozaki, Tomoyuki Fujioka, Yusuke Matsui, Kenji Hirata, Fuminari Tatsugami, Shinji Naganawa
Due primarily to the excellent soft tissue contrast depictions provided by MRI, the widespread application of head and neck MRI in clinical practice serves to assess various diseases. Artificial intelligence (AI)-based methodologies, particularly deep learning analyses using convolutional neural networks, have recently gained global recognition and have been extensively investigated in clinical research for their applicability across a range of categories within medical imaging, including head and neck MRI...
August 1, 2023: Magnetic Resonance in Medical Sciences: MRMS
Naoto Fujita, Suguru Yokosawa, Toru Shirai, Yasuhiko Terada
PURPOSE: Deep neural networks (DNNs) for MRI reconstruction often require large datasets for training. Still, in clinical settings, the domains of datasets are diverse, and how robust DNNs are to domain differences between training and testing datasets has been an open question. Here, we numerically and clinically evaluate the generalization of the reconstruction networks across various domains under clinically practical conditions and provide practical guidance on what points to consider when selecting models for clinical application...
July 28, 2023: Magnetic Resonance in Medical Sciences: MRMS
Hideki Hoshi, Reiji Sugita, Yoshio Machida
The usefulness of a highly targeted pencil beam (PB) label was compared with the commonly used slab label for direct visualization of pancreaticobiliary reflux using the time-spatial labeling inversion pulse (time-SLIP) technique. Signal profiles of flow phantom images obtained with a 1.5T MRI were analyzed. Both labels had similar labeling capabilities, but the edge characteristics of the PB label were blunt. Next, sixty-eight patients were classified into two groups according to the angle of the pancreaticobiliary ducts, and the displacement of the pancreatic ducts in respiratory fluctuation was measured...
June 21, 2023: Magnetic Resonance in Medical Sciences: MRMS
Naoya Kinota, Hiroyuki Kameda, Bai Xiawei, Takaaki Fujii, Daisuke Kato, Bunya Takahashi, Ryo Morita, Daisuke Abo, Ryusei Majima, Hiroshi Ishii, Kazuyuki Minowa, Kohsuke Kudo
PURPOSE: To investigate whether deep cervical lymph node (DCLN) ligation alters intracranial cerebrospinal fluid (CSF) tracer dynamics and outflow using a rat model with intrathecal dynamic contrast-enhanced (DCE) MRI. METHODS: Six bilateral DCLN-ligated and six sham-operated rats were subjected to DCE MRI with Gd-BTDO3A, and dynamic T1-weighted images were acquired. ROIs were collected from the CSF at the C1 level (CSF_C1), CSF between the olfactory bulbs (CSF_OB), CSF at the pituitary recess (CSF_PitR), and CSF at the pineal recess (CSF_PinR), upper nasal turbinate (UNT), olfactory bulbs, cerebrum, and the jugular region...
May 30, 2023: Magnetic Resonance in Medical Sciences: MRMS
Aika Okazawa, Mami Iima, Masako Kataoka, Ryosuke Okumura, Sachiko Takahara, Tomotaka Noda, Taro Nishi, Takayoshi Ishimori, Yuji Nakamoto
PURPOSE: We aimed to investigate the diagnostic feasibility of an adjusted diffusion-weighted imaging (DWI) lexicon using multiple b values to assess breast lesions according to DWI-based breast imaging reporting and data system (BI-RADS). METHODS: This Institutional Review Board (IRB)-approved prospective study included 127 patients with suspected breast cancer. Breast MRI was performed using a 3T scanner. Breast DW images were acquired using five b-values of 0, 200, 800, 1000, and 1500 s/mm2 (5b-value DWI) on 3T MRI...
May 26, 2023: Magnetic Resonance in Medical Sciences: MRMS
Minkyeong Kim, Tae Young Lee, Byeong Seong Kang, Woon Jung Kwon, Soyeoun Lim, Gyeong Min Park, Minseo Bang
PURPOSE: Although diffusion-weighted imaging (DWI) with ultra-high b-values is reported to be advantageous in the detection of some tumors, its applicability is not yet known in biliary malignancy. Therefore, this study aimed to evaluate the impact of measured b = 1400 s/mm2 (M1400) and calculated b = 1400 s/mm2 (C1400) DWI on image quality and quality of lesion discernibility using a modern 3T MR system compared to conventional b = 800 s/mm2 DWI (M800). METHODS: We evaluated 56 patients who had pathologically proven biliary malignancy...
May 13, 2023: Magnetic Resonance in Medical Sciences: MRMS
Shoko Hara, Masaaki Hori, Koji Kamagata, Christina Andica, Motoki Inaji, Yoji Tanaka, Shigeki Aoki, Tadashi Nariai, Taketoshi Maehara
PURPOSE: Moyamoya disease (MMD) is a cerebrovascular disease associated with steno-occlusive changes in the arteries of the circle of Willis and with hemodynamic impairment. Previous studies have reported that parenchymal extracellular free water levels may be increased and the number of neurites may be decreased in patients with MMD. The aim of the present study was to investigate the postoperative changes in parenchymal free water and neurites and their relationship with cognitive improvement...
April 18, 2023: Magnetic Resonance in Medical Sciences: MRMS
Daiki Ito, Tetsushi Habe, Tomokazu Numano, Shigeo Okuda, Shigeyoshi Soga, Masahiro Jinzaki
PURPOSE: This study aimed to facilitate research progress in MR elastography (MRE) by providing a versatile and convenient application for MRE reconstruction, namely the MRE research tool (MRE-rTool). It can be used for a series of MRE image analyses, including phase unwrapping, arbitrary bandpass and directional filtering, noise assessment of the wave propagation image (motion SNR), and reconstruction of the elastogram in both 2D and 3D MRE acquisitions. To reinforce the versatility of MRE-rTool, the conventional method of motion SNR was modified into a new method that reflects the effects of image filtering...
April 12, 2023: Magnetic Resonance in Medical Sciences: MRMS
Shimpei Kato, Ryo Kurokawa, Fumio Suzuki, Shiori Amemiya, Takahiro Shinozaki, Daiki Takanezawa, Ryutaro Kohashi, Osamu Abe
PURPOSE: Burning mouth syndrome (BMS) is defined by a burning sensation or pain in the tongue or other oral sites despite the presence of normal mucosa on inspection. Both psychiatric and neuroimaging investigations have examined BMS; however, there have been no analyses using the neurite orientation dispersion and density imaging (NODDI) model, which provides detailed information of intra- and extracellular microstructures. Therefore, we performed voxel-wise analyses using both NODDI and diffusion tensor imaging (DTI) models and compared the results to better comprehend the pathology of BMS...
March 29, 2023: Magnetic Resonance in Medical Sciences: MRMS
Kengo Kiso, Takahiro Tsuboyama, Hiromitsu Onishi, Kazuya Ogawa, Atsushi Nakamoto, Mitsuaki Tatsumi, Takashi Ota, Hideyuki Fukui, Keigo Yano, Toru Honda, Shinji Kakemoto, Yoshihiro Koyama, Hiroyuki Tarewaki, Noriyuki Tomiyama
PURPOSE: To compare the effects of deep learning reconstruction (DLR) on respiratory-triggered T2-weighted MRI of the liver between single-shot fast spin-echo (SSFSE) and fast spin-echo (FSE) sequences. METHODS: Respiratory-triggered fat-suppressed liver T2-weighted MRI was obtained with the FSE and SSFSE sequences at the same spatial resolution in 55 patients. Conventional reconstruction (CR) and DLR were applied to each sequence, and the SNR and liver-to-lesion contrast were measured on FSE-CR, FSE-DLR, SSFSE-CR, and SSFSE-DLR images...
March 29, 2023: Magnetic Resonance in Medical Sciences: MRMS
Vadim Malis, Won C Bae, Asako Yamamoto, Yoshimori Kassai, Marin A McDonald, Mitsue Miyazaki
PURPOSE: Fatty acid composition of the orbit makes it challenging to achieve complete fat suppression during orbit MR imaging. Implementation of a fat suppression technique capable of suppressing signals from saturated (aliphatic) and unsaturated (olefinic or protons at double-bonded carbon sites) fat would improve the visualization of an optical nerve. Furthermore, the ability to semi-quantify the fractions of aliphatic and olefinic fat may potentially provide valuable information in assessing orbit pathology...
March 23, 2023: Magnetic Resonance in Medical Sciences: MRMS
Masatoshi Iwamura, Satoru Ide, Kenya Sato, Akihisa Kakuta, Soichiro Tatsuo, Atsushi Nozaki, Tetsuya Wakayama, Tatsuya Ueno, Rie Haga, Misako Kakizaki, Yoko Yokoyama, Ryoichi Yamauchi, Fumiyasu Tsushima, Koichi Shibutani, Masahiko Tomiyama, Shingo Kakeda
PURPOSE: Brain MRI with high spatial resolution allows for a more detailed delineation of multiple sclerosis (MS) lesions. The recently developed deep learning-based reconstruction (DLR) technique enables image denoising with sharp edges and reduced artifacts, which improves the image quality of thin-slice 2D MRI. We, therefore, assessed the diagnostic value of 1 mm-slice-thickness 2D T2-weighted imaging (T2WI) with DLR (1 mm T2WI with DLR) compared with conventional MRI for identifying MS lesions...
March 16, 2023: Magnetic Resonance in Medical Sciences: MRMS
Makoto Obara, Jihun Kwon, Masami Yoneyama, Yu Ueda, Marc Van Cauteren
Since its first observation in the 18th century, the diffusion phenomenon has been actively studied by many researchers. Diffusion-weighted imaging (DWI) is a technique to probe the diffusion of water molecules and create a MR image with contrast based on the local diffusion properties. The DWI pixel intensity is modulated by the hindrance the diffusing water molecules experience. This hindrance is caused by structures in the tissue and reflects the state of the tissue. This characteristic makes DWI a unique and effective tool to gain more insight into the tissue's pathophysiological condition...
March 15, 2023: Magnetic Resonance in Medical Sciences: MRMS
Mitsue Miyazaki, Vadim Malis, Asako Yamamoto, Jirach Kungsamutr, Linda K McEvoy, Marin A McDonald, Won C Bae
PURPOSE: Cerebrospinal fluid (CSF) clearance is essential for maintaining a healthy brain and cognition by removal of metabolic waste from the central nervous system. Physical exercise has been shown to improve human health; however, the effect of physical exercise on intrinsic CSF outflow in humans remains unexplored. The purpose of this study was to investigate intrinsic CSF outflow pathways and quantitative metrics of healthy individuals with active and sedentary lifestyles. In addition, the effect of exercise was investigated among the sedentary subjects before and after 3 weeks of physical activity...
March 11, 2023: Magnetic Resonance in Medical Sciences: MRMS
Hiroaki Shimizu, Naoko Mori, Shunji Mugikura, Yui Maekawa, Minoru Miyashita, Tatsuo Nagasaka, Satoko Sato, Kei Takase
PURPOSE: To evaluate the effectiveness of the texture analysis of axillary high-resolution 3D T2-weighted imaging (T2WI) in distinguishing positive and negative lymph node (LN) metastasis in patients with clinically node-negative breast cancer. METHODS: Between December 2017 and May 2021, 242 consecutive patients underwent high-resolution 3D T2WI and were classified into the training (n = 160) and validation cohorts (n = 82). We performed manual 3D segmentation of all visible LNs in axillary level I to extract the texture features...
March 1, 2023: Magnetic Resonance in Medical Sciences: MRMS
Fetch more papers »
Fetching more papers... Fetching...
Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"

We want to hear from doctors like you!

Take a second to answer a survey question.