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proton density MRI

Robin De Roover, Wouter Crijns, Kenneth Poels, Ronald Peeters, Cédric Draulans, Karin Haustermans, Tom Depuydt
PURPOSE: Liquid fiducial markers have shown to be a promising alternative to solid gold markers in terms of imaging artifact reduction, patient comfort and compatibility with different imaging modalities. This study aims to investigate the performance of the novel BioXmark® liquid marker for state-of-the-art multi-modal imaging used in prostate cancer (PCa) radiotherapy, encompassing kV CT/CBCT, multi-parametric MRI and kV X-ray imaging. In addition, automatic detection of the liquid markers in X-ray imaging for prostate motion monitoring during treatment was investigated...
March 14, 2018: Medical Physics
Okihiro Onishi, Kazuya Ikoma, Masamitsu Kido, Yukichi Kabuto, Keiichiro Ueshima, Ken-Ichi Matsuda, Masaki Tanaka, Toshikazu Kubo
BACKGROUND: Articular cartilage degeneration has been evaluated by magnetic resonance imaging (MRI). However, this method has several problems, including its time-consuming nature and the requirement of a high magnetic field or specialized hardware. The purpose of this study was to sequentially assess early degenerative changes in rabbit knee articular cartilage using MRI with a new double-contrast agent. METHODS: We induced osteoarthritis (OA) in the right knee of rabbits by anterior cruciate ligament transection and partial medial meniscectomy...
March 13, 2018: BMC Musculoskeletal Disorders
Stephen A Harrison, Mary E Rinella, Manal F Abdelmalek, James F Trotter, Angelo H Paredes, Hays L Arnold, Marcelo Kugelmas, Mustafa R Bashir, Mark J Jaros, Lei Ling, Stephen J Rossi, Alex M DePaoli, Rohit Loomba
BACKGROUND: Non-alcoholic steatohepatitis is a chronic liver disease characterised by the presence of hepatic steatosis, inflammation, and hepatocellular injury, for which no Food and Drug Administration (FDA)-approved treatment exists. FGF19 is a hormone that regulates bile acid synthesis and glucose homoeostasis. We aimed to assess the safety and efficacy of NGM282, an engineered FGF19 analogue, for the treatment of non-alcoholic steatohepatitis. METHODS: In this randomised, double-blind, placebo-controlled, phase 2 study, we recruited patients aged 18-75 years with biopsy-confirmed non-alcoholic steatohepatitis as defined by the non-alcoholic steatohepatitis clinical research network histological scoring system, from hospitals and gastroenterology and liver clinics in Australia and the USA...
March 5, 2018: Lancet
So Mi Lee, Young Hun Choi, Sun-Kyoung You, Won Kee Lee, Won Hwa Kim, Hye Jung Kim, Sang Yub Lee, Hyejin Cheon
OBJECTIVES: The properties of brain tissue undergo dynamic changes during maturation. T1 relaxation time (T1), T2 relaxation time (T2), and proton density (PD) are now simultaneously quantifiable within a clinically acceptable time, using a synthetic magnetic resonance imaging (MRI) sequence. This study aimed to provide age-specific reference values for T1, T2, and PD in children, using synthetic MRI. MATERIALS AND METHODS: We included 89 children (median age, 18 months; range, 34 weeks of gestational age to 17 years) who underwent quantitative MRI, using a multidynamic, multiecho sequence on 3 T MRI, between December 2015 and November 2016, and had no abnormal MRI/neurologic assessment findings...
April 2018: Investigative Radiology
M Drake-Pérez, B M A Delattre, J Boto, A Fitsiori, K-O Lovblad, S Boudabbous, M I Vargas
BACKGROUND AND PURPOSE: SyMRI is a technique developed to perform quantitative MR imaging. Our aim was to analyze its potential use for measuring relaxation times of normal components of the spine and to compare them with values found in the literature using relaxometry and other techniques. MATERIALS AND METHODS: Thirty-two spine MR imaging studies (10 cervical, 5 dorsal, 17 lumbosacral) were included. A modified multiple-dynamic multiple-echo sequence was added and processed to obtain quantitative T1 (millisecond), T2 (millisecond), and proton density (percentage units [pu]) maps for each patient...
March 1, 2018: AJNR. American Journal of Neuroradiology
Saya Horiuchi, Taiki Nozaki, Atsushi Tasaki, Sachiko Ohde, Gautam A Deshpande, Jay Starkey, Takeshi Hara, Nobuto Kitamura, Hiroshi Yoshioka
OBJECTIVE: The aims of this study were to compare isotropic 3-dimensional fat-suppressed T2-weighted fast spin echo (FSE) imaging (T2FS) with 2-dimensional fat-suppressed proton-density-weighted FSE imaging (2D-PDFS) and evaluate feasibility of isotropic 3-dimensional FSE shoulder imaging at 3-T magnetic resonance imaging (MRI). METHODS: Seventy-eight patients who underwent shoulder MRI were evaluated. Three-dimensional T2FS and 2D-PDFS were qualitatively graded for delineation of anatomic structures...
February 27, 2018: Journal of Computer Assisted Tomography
Daiki Tamada, Tetsuya Wakayama, Hiroshi Onishi, Utaroh Motosugi
PURPOSE: To develop multiparameter mapping including T1 , R2*, and proton density fat fraction with a single breath-hold to evaluate liver disease and liver function. METHODS: A 6-echo spoiled gradient-echo sequence with dual flip angles was used to acquire a 12-set MRI volume data set. To shorten the scan time, undersampling and multicontrast compressed-sensing reconstruction were used. The scan time was 18 seconds. R2* and proton density fat fraction mapping were achieved by using the iterative least-squares method...
February 24, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Natsuo Konta, Syuhei Shibukawa, Tomoaki Hakucho, Tomohiko Horie, Makoto Obara
Synthetic MRI can provide proton density (PD), T1 value, T2 value for each pixel by only one data acquisition and can create various contrast-weighted images. The aim of this study is to evaluate the effect on the calculation of the T1 ·T2 value when changing the scan parameters for synthetic MRI. In the phantom study, when changing 1st TE/2nd TE/TR/TSE factor, the effect on the T1 ·T2 value calculated by synthetic MRI was examined. In the volunteer study, the brain was imaged and compared with known T1 ·T2 value...
2018: Nihon Hoshasen Gijutsu Gakkai Zasshi
Francesca Pennati, David J Roach, John P Clancy, Alan S Brody, Robert J Fleck, Andrea Aliverti, Jason C Woods
BACKGROUND: Lung disease is the most frequent cause of morbidity and mortality in patients with cystic fibrosis (CF), and there is a shortage of sensitive biomarkers able to regionally monitor disease progression and to assess early responses to therapy. PURPOSE: To determine the feasibility of noncontrast-enhanced multivolume MRI, which assesses intensity changes between expiratory and inspiratory breath-hold images, to detect and quantify regional ventilation abnormalities in CF lung disease, with a focus on the structure-function relationship...
February 19, 2018: Journal of Magnetic Resonance Imaging: JMRI
Risa Matsubara, Yoshinobu Yanagi, Kazuhiro Oki, Miki Hisatomi, Karina Cp Santos, Babatunde O Bamgbose, Mariko Fujita, Shunsuke Okada, Shogo Minagi, Junichi Asaumi
OBJECTIVES: To investigate the correlations among various temporomandibular joint (TMJ) findings on MRI and the relationships between MRI findings and symptoms. METHODS: 425 patients (850 TMJs) with temporomandibular joint disorders (TMDs) who underwent MRI were enrolled. Oblique sagittal proton density-weighted and T2 weighted images in open- and closed-mouth positions were evaluated. MRI findings included disc configuration, disc position, condylar morphology, bone marrow pattern, and joint effusion...
February 16, 2018: Dento Maxillo Facial Radiology
Junmin Liu, Spencer D Christiansen, Maria Drangova
Multi-echo gradient echo (mGRE) sequences have been widely adapted in clinical and scientific practice for different purposes to their capability of performing Dixon MRI, generating multi-contrast images and extracting multi-parametric maps. This work aims to extend mGRE-based techniques for imaging whole head, where further technical developments are required due to the co-existence of fat and large B0 inhomogeneity in regions such as the skull base and neck. Specifically, bipolar mGRE data were acquired with a single sequence that contains both a short echo-spacing (ΔTE) echo train to capture water-fat and B0 phase shifts (for proton density fat-fraction (FF) and B0 mapping) and a longer ΔTE echo train (and long echo times) to capture subtle susceptibility variations and R2* information...
February 13, 2018: NeuroImage
Tatsuya Hayashi, Kei Fukuzawa, Hidekazu Yamazaki, Takashi Konno, Tosiaki Miyati, Jun'ichi Kotoku, Hiroshi Oba, Hiroshi Kondo, Keiko Toyoda, Satoshi Saitoh
PURPOSE: To evaluate the reproducibility of proton density fat fraction (PDFF) and T2* in a fat-water phantom on three different 3 T MRI systems using 6-point DIXON methods. METHODS: A phantom which included varying fat volume percentages (true fat fraction [FF]) was scanned by three 3 T MR machines, and PDFF and T2* were measured. RESULTS: The mean difference between true FF and PDFF was small in all vendors (-2.11% to 0.41%). However, the difference ratio for T2* values was large among vendors (1...
February 2, 2018: Clinical Imaging
Fumihito Yoshii, Hitoshi Tomiyasu, Ryo Watanabe, Masafuchi Ryo
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant spinocerebellar degeneration, associated with extended repeats of the trinucleotide CAG in the ATXN2 gene on the long arm of chromosome 12. Magnetic resonance imaging (MRI) of SCA2 showed significant atrophies of the brainstem, middle cerebellar peduncles, and cerebellum. We report two genetically proven SCA2 patients who showed hypertrophy of the inferior olivary nuclei on proton density- and T2-weighted MRI. This pattern has never been reported in patients with SCA1, SCA3, or SCA6, and may make it possible to differentiate SCA2 from other hereditary spinocerebellar ataxias...
September 2017: Case Reports in Neurology
Janne West, Thobias Romu, Sofia Thorell, Hanna Lindblom, Emilia Berin, Anna-Clara Spetz Holm, Lotta Lindh Åstrand, Anette Karlsson, Magnus Borga, Mats Hammar, Olof Dahlqvist Leinhard
OBJECTIVES: To determine precision of magnetic resonance imaging (MRI) based fat and muscle quantification in a group of postmenopausal women. Furthermore, to extend the method to individual muscles relevant to upper-body exercise. MATERIALS AND METHODS: This was a sub-study to a randomized control trial investigating effects of resistance training to decrease hot flushes in postmenopausal women. Thirty-six women were included, mean age 56 ± 6 years. Each subject was scanned twice with a 3...
2018: PloS One
Rong Guo, Yoann Petibon, Yixin Ma, Georges El Fakhri, Kui Ying, Jinsong Ouyang
BACKGROUND: Both cardiac and respiratory motions bias the kinetic parameters measured by dynamic PET. The aim of this study was to perform a realistic positron emission tomography-magnetic resonance (PET-MR) simulation study using 4D XCAT to evaluate the impact of MR-based motion correction on the estimation of PET myocardial kinetic parameters using PET-MR. Dynamic activity distributions were obtained based on a one-tissue compartment model with realistic kinetic parameters and an arterial input function...
February 1, 2018: EJNMMI Physics
Mónica Giraldo-Chica, Keith A Schneider
Human brain asymmetry reflects normal specialization of functional roles and may derive from evolutionary, hereditary, developmental, experiential, and pathological factors (Toga & Thompson, 2003). Geschwind and Galaburda (1985) suggested that processing difficulties in dyslexia are due to structural differences between hemispheres. Because of its potential significance to the controversial magnocellular theory of dyslexia, we investigated hemispheric differences in the human lateral geniculate nucleus (LGN), the primary visual relay and control nucleus in the thalamus, in subjects with dyslexia compared to normal readers...
January 29, 2018: Dyslexia: the Journal of the British Dyslexia Association
Thorsten Lichtenstein, Alina Sprenger, Kilian Weiss, Karin Slebocki, Barbara Cervantes, Dimitrios Karampinos, David Maintz, Gereon R Fink, Tobias D Henning, Helmar C Lehmann
Objective: To evaluate the utility of nerve diffusion tensor imaging (DTI), nerve cross-sectional area, and muscle magnetic resonance imaging (MRI) multiecho Dixon for assessing proximal nerve injury in chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: In this prospective observational cohort study, 11 patients with CIDP and 11 healthy controls underwent a multiparametric MRI protocol with DTI of the sciatic nerve and assessment of muscle proton-density fat fraction of the biceps femoris and the quadriceps femoris muscles by multiecho Dixon MRI...
January 2018: Annals of Clinical and Translational Neurology
Marina Y Khodanovich, Alena A Kisel, Andrey E Akulov, Dmitriy N Atochin, Marina S Kudabaeva, Valentina Y Glazacheva, Michael V Svetlik, Yana A Medvednikova, Lilia R Mustafina, Vasily L Yarnykh
A recent MRI method, fast macromolecular proton fraction (MPF) mapping, was used to quantify demyelination in the transient middle cerebral artery occlusion (MCAO) rat stroke model. MPF and other quantitative MRI parameters (T1, T2, proton density, and apparent diffusion coefficient) were compared with histological and immunohistochemical markers of demyelination (Luxol Fast Blue stain, (LFB)), neuronal loss (NeuN immunofluorescence), axonal loss (Bielschowsky stain), and inflammation (Iba1 immunofluorescence) in three animal groups ( n = 5 per group) on the 1st, 3rd, and 10th day after MCAO...
January 1, 2018: Journal of Cerebral Blood Flow and Metabolism
Masataka Minami, Kazuya Ikoma, Motoyuki Horii, Tsuyoshi Sukenari, Okihiro Onishi, Hiroyoshi Fujiwara, Hiroshi Ogi, Kyoko Itoh, Toshikazu Kubo
BACKGROUND: Diabetes decreases bone strength, possibly because of cortical bone changes. Sweep imaging with Fourier transform (SWIFT) has been reported to be useful for cortical bone evaluation. PURPOSE: To evaluate cortical bone changes in diabetic rats using SWIFT, assess the usefulness of this technique through comparisons with microcomputed tomography (μCT) and conventional MRI, and clarify the mechanism underlying cortical bone changes using histomorphometry STUDY TYPE: Animal cohort...
January 23, 2018: Journal of Magnetic Resonance Imaging: JMRI
Cyrielle Caussy, Scott B Reeder, Claude B Sirlin, Rohit Loomba
Nonalcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease worldwide, and the progressive form of this condition, nonalcoholic steatohepatitis (NASH), has become one of the leading indications for liver transplant. Despite intensive investigations, there are currently no FDA approved therapies for treating NASH. A major barrier for drug development in NASH is that treatment response assessment continues to require liver biopsy, which is invasive and interpreted subjectively...
January 21, 2018: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
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