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Magnetic Resonance in Medical Sciences: MRMS

Yutaka Shigenaga, Masato Sasaki, Takeshi Ishimoto, Keiko Ama
The sequence for concurrently depicting engulfed vessels and a well-enhanced tumor in once-off scanning has never been reported for preoperative magnetic resonance imaging for brain tumor resection. Multimodal fusion techniques have been recently developed, but the risks of misregistration still remain. Here a case is reported where contrast-enhanced three-dimensional phase contrast sequence concurrently depicted an engulfed vessel and metastatic brain tumor in once-off scanning and related technical aspects are discussed...
May 24, 2017: Magnetic Resonance in Medical Sciences: MRMS
Shinji Naganawa, Hisashi Kawai, Toshiaki Taoka, Michihiko Sone
To improve the imaging protocol for the evaluation of endolymphatic hydrops after intravenous administration of a gadolinium-based contrast agent, we modified our previously reported hybrid of reversed image of positive endolymph signal and native image of positive perilymph signal (HYDROPS) method. Although the scan time of the new protocol was half that of the previous one, there were no significant differences between two protocols in the mean contrast noise ratio between the endolymph and perilymph and the area ratio of the endolymph size values in nine patients...
May 22, 2017: Magnetic Resonance in Medical Sciences: MRMS
Keita Kuya, Yuki Shinohara, Hiroki Yoshioka, Satoshi Kuwamoto, Masamichi Kurosaki, Toshihide Ogawa
No abstract text is available yet for this article.
May 22, 2017: Magnetic Resonance in Medical Sciences: MRMS
Shinya Fujii, Kanae Nosaka, Naoko Mukuda, Takeru Fukunaga, Shinya Sato, Toshihide Ogawa
No abstract text is available yet for this article.
May 22, 2017: Magnetic Resonance in Medical Sciences: MRMS
Selim Doganay, Kazim Gumus, Gonca Koc, Ayse Kacar Bayram, Mehmet Sait Dogan, Duran Arslan, Hakan Gumus, Sureyya Burcu Gorkem, Saliha Ciraci, Halil Ibrahim Serin, Abdulhakim Coskun
OBJECTIVES: Wilson's disease (WD) is characterized with the accumulation of copper in the liver and brain. The objective of this study is to quantitatively measure the susceptibility changes of basal ganglia and brain stem of pediatric patients with neurological WD using quantitative susceptibility mapping (QSM) in comparison to healthy controls. METHODS: Eleven patients with neurological WD (mean age 15 ± 3.3 years, range 10-22 years) and 14 age-matched controls were prospectively recruited...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
Noriyuki Fujima, Tomohiro Sakashita, Akihiro Homma, Daisuke Yoshida, Kohsuke Kudo, Hiroki Shirato
PURPOSE: To evaluate the diagnostic power of hybrid intravoxel incoherent motion (IVIM)-diffusion kurtosis imaging (DKI) model parameters in pretreatment for the prediction of future distant metastasis in head and neck squamous cell carcinoma (HNSCC) patients. MATERIALS AND METHODS: We retrospectively evaluated 49 HNSCC patients who underwent curative chemoradiation therapy. Diffusion-weighted image (DWI) acquired by single-shot spin-echo echo-planar imaging with 12 b-values (0-2000) was performed in all patients before any treatment...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
Mayumi Takeuchi, Kenji Matsuzaki, Masafumi Harada
PURPOSE: To compare the diagnostic ability of reduced field-of-view (FOV) diffusion-weighted (DW) magnetic resonance (MR) imaging with that of three-dimensional (3D) dynamic contrast-enhanced (DCE) MR imaging in evaluating the depth of myometrial invasion in patients with endometrial cancer. METHODS: Three tesla (3T) MR images including T2-weighted imaging, reduced FOV DW imaging and 3D DCE MR imaging in sagittal and oblique axial (short axis) planes in 25 women with surgically proven endometrial cancer were retrospectively evaluated...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
Kazuhiro Murayama, Yuya Nishiyama, Yuichi Hirose, Masato Abe, Shigeharu Ohyu, Ayako Ninomiya, Takashi Fukuba, Kazuhiro Katada, Hiroshi Toyama
PURPOSE: We evaluated the diagnostic performance of histogram analysis of data from a combination of dynamic susceptibility contrast (DSC)-magnetic resonance imaging (MRI) and dynamic contrast-enhanced (DCE)-MRI for quantitative differentiation between central nervous system lymphoma (CNSL) and high-grade glioma (HGG), with the aim of identifying useful perfusion parameters as objective radiological markers for differentiating between them. METHODS: Eight lesions with CNSLs and 15 with HGGs who underwent MRI examination, including DCE and DSC-MRI, were enrolled in our retrospective study...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
Kosuke Morita, Seitaro Oda, Daisuke Utsunomiya, Takeshi Nakaura, Takatoshi Matsubara, Makoto Goto, Tomoyuki Okuaki, Hideaki Yuki, Yasunori Nagayama, Masafumi Kidoh, Kenichiro Hirata, Yuij Iyama, Narumi Taguchi, Masahiro Hatemura, Masahiro Hashida, Yasuyuki Yamashita
PURPOSE: To evaluate the effect of a composite radiofrequency (RF) pulse on saturation recovery (SR) myocardial T1 mapping using a 3T magnetic resonance (MR) system. MATERIALS AND METHODS: Phantom and in vivo studies were performed with a clinical 3T MR scanner. Accuracy and reproducibility of the SR T1 mapping using conventional and composite RF pulses were first compared in phantom experiments. An in vivo study was performed of 10 healthy volunteers who were imaged with conventional and composite RF pulse methods twice each...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
Koichi Ito, Yumiko Oishi Tanaka, Ryosuke Watanabe, Hiroko Tanaka, Yutaka Takazawa, Kiyoshi Matsueda
No abstract text is available yet for this article.
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
Nao Kodama, Ayana Setoi, Katsumi Kose
Spiral magnetic resonance imaging (MRI) sequences were developed for a 9.4T vertical standard bore (54 mm) superconducting magnet using unshielded and self-shielded gradient coils. Clear spiral images with 64-shot scan were obtained with the self-shielded gradient coil, but severe shading artifacts were observed for the spiral-scan images acquired with the unshielded gradient coil. This shading artifact was successfully corrected with a phase-correction technique using reference scans that we developed based on eddy current field measurements...
March 27, 2017: Magnetic Resonance in Medical Sciences: MRMS
Tetsuro Sekine, Ryo Takagi, Yasuo Amano, Yasuo Murai, Erika Orita, Yoshimitsu Fukushima, Yoshio Matsumura, Shin-Ichiro Kumita
BACKGROUND AND PURPOSE: To assess the clinical feasibility of time-resolved three-dimensional phase contrast (4D Flow) magnetic resonance imaging (MRI) assessment of the ophthalmic artery (OphA) flow in patients with internal carotid artery stenosis (ICS). MATERIALS AND METHODS: Twenty-one consecutive patients with unilateral ICS were recruited. 4D Flow MRI and acetazolamide-stress brain perfusion single photon emission computed tomography (SPECT) were performed...
March 27, 2017: Magnetic Resonance in Medical Sciences: MRMS
Ryota Sato, Toru Shirai, Yo Taniguchi, Takenori Murase, Yoshitaka Bito, Hisaaki Ochi
Quantitative susceptibility mapping (QSM) is a new magnetic resonance imaging (MRI) technique for noninvasively estimating the magnetic susceptibility of biological tissue. Several methods for QSM have been proposed. One of these methods can estimate susceptibility with high accuracy in tissues whose contrast is consistent between magnitude images and susceptibility maps, such as deep gray-matter nuclei. However, the susceptibility of small veins is underestimated and not well depicted by using the above approach, because the contrast of small veins is inconsistent between a magnitude image and a susceptibility map...
March 27, 2017: Magnetic Resonance in Medical Sciences: MRMS
Enrico Tedeschi, Sirio Cocozza, Pasquale Borrelli, Lorenzo Ugga, Vincenzo Brescia Morra, Giuseppe Palma
We report the assessment of Dentate Nuclei (DN) R1 (1/T1) and R2* (1/R2*) values in a patient with relapsing-remitting Multiple Sclerosis, exposed to 22 standard (0.1 mmol/kg) doses of gadobutrol, who underwent eight relaxometric magnetic resonance (MR) measurements within two years. DN R1 did not significantly increase nor correlated with cumulative gadobutrol administration, even after a total dose of 130 ml. Likewise, DN R2* relaxometry remained unchanged. In conclusion, massive gadobutrol exposure did not induce significant DN relaxometry changes...
March 27, 2017: Magnetic Resonance in Medical Sciences: MRMS
Utaroh Motosugi
No abstract text is available yet for this article.
March 9, 2017: Magnetic Resonance in Medical Sciences: MRMS
Mitsushi Abe
PURPOSE: To develop a new shimming calculation method, which can calculate iron piece placements rapidly to make the magnetic field homogeneous at intended homogeneity and then to make the shimming working time short. MATERIALS AND METHODS: The shimming calculation yields magnetic moment (MM) distribution, which is calculated by the truncated singular value decomposition (SVD) from the measured magnetic field. The MM distribution is described by a superposition of eigenmodes obtained by SVD of a response matrix from the moment distributions to magnetic fields at the field of view (FOV)...
March 2, 2017: Magnetic Resonance in Medical Sciences: MRMS
Tokunori Kimura, Hiroshi Kusahara
We proposed and assessed a modified asymmetric Fourier imaging (AFI) technique named real-based polarity-preserving AFI (RepAFI), in which the low-pass filter kernel for background phase estimation in AFI is optimized to preserve the magnetization polarity information for blood vessels and cerebrospinal fluid (CSF) even for data obtained using phase-sensitive inversion-recovery spin-echo-based (PSIR-SE) sequences with asymmetrical sampling in the k-space. Our proposed RepAFI technique achieves a practical balance of image quality and simplicity to provide better performance than conventional AFI methods...
April 10, 2017: Magnetic Resonance in Medical Sciences: MRMS
Gou Ogasawara, Yusuke Inoue, Keiji Matsunaga, Kaoru Fujii, Hirofumi Hata, Yuki Takato
PURPOSE: Image non-uniformity may cause substantial problems in magnetic resonance (MR) imaging especially when a 3-T scanner is used. We evaluated the effect of image non-uniformity correction in gadolinium ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MR imaging using a 3-T scanner. METHODS: Two commercially available methods for image non-uniformity correction, surface coil intensity correction (SCIC), and phased-array uniformity enhancement (PURE), were applied to Gd-EOB-DTPA-enhanced images acquired at 3-T in 20 patients...
April 10, 2017: Magnetic Resonance in Medical Sciences: MRMS
Hirofumi Hata, Yusuke Inoue, Ai Nakajima, Shotaro Komi, Hiroki Miyatake
PURPOSE: We quantitatively investigated hepatic enhancement in gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging at 1.5T and 3.0T. METHODS: A total of 40 patients who underwent Gd-EOB-DTPA-enhanced MR imaging were included in the study. Precontrast and hepatobiliary-phase images acquired at a low flip angle (FA, 12°) and hepatobiliary-phase images acquired at a high FA (30°) were analyzed. From these images, the liver-to-muscle signal intensity ratio (LMR) and liver-to-spleen signal intensity ratio (LSR) were estimated, and the contrast enhancement ratio (CER) was calculated from the liver signal, LMR, and LSR as the ratio of the low-FA hepatobiliary-phase value to the precontrast value...
April 10, 2017: Magnetic Resonance in Medical Sciences: MRMS
Shinji Naganawa, Toshiki Nakane, Hisashi Kawai, Toshiaki Taoka, Kojiro Suzuki, Shingo Iwano, Hiroko Satake, David Grodzki
PURPOSE: To evaluate the visualization of middle ear ossicles by ultra-short echo time magnetic resonance (MR) imaging at 3T in subjects over 50 years old. MATERIALS AND METHODS: Sixty ears from 30 elder patients that underwent surgical or interventional treatment for neurovascular diseases were included (ages: 50-82, median age: 65; 10 men, 20 women). Patients received follow-up MR imaging including routine T1- and T2-weighted images, time-of-flight MR angiography, and ultra-short echo time imaging (PETRA, pointwise encoding time reduction with radial acquisition)...
April 10, 2017: Magnetic Resonance in Medical Sciences: MRMS
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