Read by QxMD icon Read

Mri sequence

Ralf B Loeffler, M Beth McCarville, Anne W Wagstaff, Matthew P Smeltzer, Axel J Krafft, Ruitian Song, Jane S Hankins, Claudia M Hillenbrand
BACKGROUND: Liver R2* values calculated from multi-gradient echo (mGRE) magnetic resonance images (MRI) are strongly correlated with hepatic iron concentration (HIC) as shown in several independently derived biopsy calibration studies. These calibrations were established for axial single-slice breath-hold imaging at the location of the portal vein. Scanning in multi-slice mode makes the exam more efficient, since whole-liver coverage can be achieved with two breath-holds and the optimal slice can be selected afterward...
October 17, 2016: Pediatric Radiology
Y M Zheng, W Z Li, Z X Wang, W Zhang, H Lv, J X Xiao, Y Yuan
OBJECTIVE: To report thigh muscle magnetic resonance imaging (MRI) tests of four Chinese patients with dystrophinopathy with edema changes in adductor longus muscles that mimics adductor enthesopathy. METHODS: Four boys, who were from four unrelated families and aged from 5 to 11 years, were investigated because of the clinical manifestations including myalgia or muscle weakness or the incidental findings of elevated serum creatine kinase levels, and were diagnosed with dystrophinopathy by gene test of Duchenne muscular dystrophy (DMD)...
October 18, 2016: Beijing da Xue Xue Bao. Yi Xue Ban, Journal of Peking University. Health Sciences
Lipeng Ning, Evren Özarslan, Carl-Fredrik Westin, Yogesh Rathi
Inferring the microstructure of complex media from the diffusive motion of molecules is a challenging problem in diffusion physics. In this paper, we introduce a novel representation of diffusion MRI (dMRI) signal from tissue with spatially-varying diffusivity using a diffusion disturbance function. This disturbance function contains information about the (intra-voxel) spatial fluctuations in diffusivity due to restrictions, hindrances and tissue heterogeneity of the underlying tissue substrate. We derive the short- and long-range disturbance coefficients from this disturbance function to characterize the tissue structure and organization...
October 14, 2016: NeuroImage
Anna Maria Pinto, Valentina Imperatore, Laura Bianciardi, Margherita Baldassarri, Paolo Galluzzi, Simone Furini, Giovanni Centini, Alessandra Renieri, Francesca Mari
Orofacial clefts are the most common congenital craniofacial anomalies and can occur as an isolated defect or be associated with other anomalies such as posterior fossa anomalies as a part of several genetic syndromes. We report two consecutive voluntary pregnancy interruptions in a nonconsanguineous couple following the fetal ultrasound finding of cleft lip and palate and posterior fossa anomalies confirmed by means of post-termination examination on the second fetus. The quantitative fluorescent PCR, the karyotype, and the comparative genomic hybridization-array analysis after amniocentesis were normal...
October 4, 2016: Clinical Dysmorphology
Jake S Burrell, Simon Walker-Samuel, Jessica K R Boult, Lauren C J Baker, Yann Jamin, Jane Halliday, John C Waterton, Simon P Robinson
The aim of this study was to use the combined carbogen-ultrasmall superparamagnetic iron oxide (CUSPIO) magnetic resonance imaging (MRI) method, which uses spatial correlations in independent susceptibility imaging biomarkers, to investigate and compare the impact of tumor size and anatomical site on vascular structure and function in vivo. Mice bearing either subcutaneous or orthotopic PC3 LN3 prostate tumors were imaged at 7 T, using a multi-gradient echo sequence to quantify R2, before and during carbogen (95% O2/5% CO2) breathing, and subsequently following intravenous administration of USPIO particles...
October 2016: Topics in Magnetic Resonance Imaging: TMRI
Renee E Shimizu, Allan D Wu, Barbara J Knowlton
Effective learning results not only in improved performance on a practiced task, but also in the ability to transfer the acquired knowledge to novel, similar tasks. Using a modified serial reaction time (RT) task, the authors examined the ability to transfer to novel sequences after practicing sequences in a repetitive order versus a nonrepeating interleaved order. Interleaved practice resulted in better performance on new sequences than repetitive practice. In a second study, participants practiced interleaved sequences in a functional MRI (fMRI) scanner and received a transfer test of novel sequences...
October 17, 2016: Behavioral Neuroscience
Ahmad Chaddad, Camel Tanougast
To isolate the brain from non-brain tissues using a fully automatic method may be affected by the presence of radio frequency non-homogeneity of MR images (MRI), regional anatomy, MR sequences, and the subjects of the study. In order to automate the brain tumor (Glioblastoma) detection, we proposed a novel approach of skull stripping for axial slices derived from MRI. Then, the brain tumor was detected using multi-level threshold segmentation based on histogram analysis. Skull-stripping method, was applied by adaptive morphological operations approach...
March 2016: Brain Informatics
Faysal F Altahawi, Kevin J Blount, Nicholas P Morley, Esther Raithel, Imran M Omar
PURPOSE: To compare a faster, new, high-resolution accelerated 3D-fast-spin-echo (3D-FSE) acquisition sequence (CS-SPACE) to traditional 2D and high-resolution 3D sequences for knee 3-T magnetic resonance imaging (MRI). MATERIALS AND METHODS: Twenty patients received knee MRIs that included routine 2D (T1, PD ± FS, T2-FS; 0.5 × 0.5 × 3 mm(3); ∼10 min), traditional 3D FSE (SPACE-PD-FS; 0.5 × 0.5 × 0.5 mm(3); ∼7.5 min), and accelerated 3D-FSE prototype (CS-SPACE-PD-FS; 0...
October 15, 2016: Skeletal Radiology
Somaie Salajeghe, Paul Babyn, Gordon E Sarty
BACKGROUND: In B1 encoded MRI, a realistic non-linear phase RF encoding coil will generate an inhomogeneous B1 field that leads to spatially dependent flip angles. The non-linearity of the B1 phase gradient can be compensated for in the reconstruction, but B1 inhomogeneity remains a problem. The effect of B1 inhomogeneity on tip angles for conventional, B0 encoded MRI, may be minimized using composite pulses. The objective of this study was to explore the feasibility of using composite pulses with non-linear RF phase encoding coils and to identify the most appropriate composite pulse scheme...
October 12, 2016: Magnetic Resonance Imaging
Kousaku Saotome, Akira Matsushita, Koji Matsumoto, Yoshiaki Kato, Kei Nakai, Koichi Murata, Tetsuya Yamamoto, Yoshiyuki Sankai, Akira Matsumura
PURPOSE: A fast spin-echo sequence based on the Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction (PROPELLER) technique is a magnetic resonance (MR) imaging data acquisition and reconstruction method for correcting motion during scans. Previous studies attempted to verify the in vivo capabilities of motion-corrected PROPELLER in real clinical situations. However, such experiments are limited by repeated, stray head motion by research participants during the prescribed and precise head motion protocol of a PROPELLER acquisition...
October 11, 2016: Magnetic Resonance Imaging
Romain Lefaucheur, Axel Lebas, Emmanuel Gérardin, Lou Grangeon, Ozlem Ozkul-Wermester, Carole Aubier-Girard, Olivier Martinaud, David Maltête
A 29-year-old man was admitted for acute cognitive impairment. Three weeks earlier, he had been admitted for coma due to sniffed heroin abuse responsive to naloxone infusion. At admission, the patient presented with apraxia, severe memory impairment and anosognosia. Brain MRI revealed symmetric hyperintensities of supratentorial white matter, sparing brainstem and cerebellum, on FLAIR and B1000 sequences. Four months later, repeated neuropsychological assessment revealed dramatic improvement of global cognitive functions...
October 11, 2016: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
Gabriella Szatmáry
PURPOSE OF REVIEW: This article presents an imaging-based approach to the differential diagnosis of visual symptoms. RECENT FINDINGS: Many neurologic disorders may present with visual symptoms. Therefore, neurologists must be familiar with the array of pathophysiologic processes that cause visual symptoms. Orbital imaging is challenging owing to the small structures and different tissue interfaces within and surrounding the orbital compartment. Some of the emerging three-dimensional MRI sequences are promising and compare well with high-resolution two-dimensional sequences in the orbits...
October 2016: Continuum: Lifelong Learning in Neurology
Andreas Heinrich, Felix V Güttler, Florian Schlesies, René Aschenbach, Niklas Eckardt, Ulf K-M Teichgräber
PURPOSE: The purpose of this study was to measure artifacts and visibility of lumen for modern and most commonly used stents in vascular interventions according to a standardized test method of the American Society for Testing and Materials (ASTM). MATERIALS AND METHODS: Twenty-four peripheral self-expanding nitinol stents and three stainless steel stents with diameters between 5 and 8 mm and lengths between 30 and 250 mm from seven different manufacturers were compared on a 1...
October 14, 2016: Biomedizinische Technik. Biomedical Engineering
Alison D Cox, Javier Virues-Ortega, Flavia Julio, Toby L Martin
Excessive motion makes magnetic resonance imaging (MRI) extremely challenging among children with autism spectrum disorder (ASD). The medical risks of sedation establish the need for behavioral interventions to promote motion control among children with ASD undergoing MRI scans. We present a series of experiments aimed at establishing both tolerance of the MRI environment and a level of motion control that would be compatible with a successful MRI. During Study 1, we evaluated the effects of prompting and contingent reinforcement on compliance with a sequence of successive approximations to an MRI using a mock MRI...
October 14, 2016: Journal of Applied Behavior Analysis
Susanne M Kaiser, Oliver Harms, Martin Konar, Anne Staudacher, Anna Langer, Cetina Thiel, Martin Kramer, Sebastian Schaub, Kerstin H von Pückler
OBJECTIVES: To describe clinical, radiographic, and magnetic resonance imaging (MRI) findings in 16 dogs diagnosed with gastrocnemius musculotendinopathy. METHODS: Retrospective evaluation of medical records, radiographs, and MRI results, as well as follow-up completed by telephone questionnaire. RESULTS: Most dogs had chronic hindlimb lameness with no history of trauma or athletic activities. Clinical examination revealed signs of pain on palpation without stifle joint instability...
October 14, 2016: Veterinary and Comparative Orthopaedics and Traumatology: V.C.O.T
Tao Xie, Wei Sun, Xiaobiao Zhang, Tengfei Liu, Hailing Ding, Fan Hu, Yong Yu, Ye Gu
BACKGROUND: In this study, we investigated the value of three-dimensional (3D) fast-imaging employing steady-state acquisition (FIESTA) magnetic resonance imaging (MRI) in detecting non-iatrogenic cerebrospinal fluid (CSF) rhinorrhoea and compared it with regular MRI and 3D magnetisation prepared rapid acquisition gradient echo (MPRAGE) MRI sequences, as well as high-resolution computed tomography (HRCT) imaging. We also present the endoscopic experiences of such cases. METHOD: From June 2011 to Feb 2016, 17 patients with non-iatrogenic cerebrospinal fluid rhinorrhoea were included...
October 13, 2016: Acta Neurochirurgica
Adam C Johnson, John H Hollman, Benjamin M Howe, Jonathan T Finnoff
OBJECTIVE: The primary aim of this study was to determine if ischiofemoral space (IFS) dimensions vary with changes in hip flexion as a result of placing a bolster behind the knees during magnetic resonance imaging (MRI). A secondary aim was to determine if IFS dimensions vary between supine and prone hip neutral positions. DESIGN: The study employed a prospective design. SETTING: Sports medicine center within a tertiary care institution. PARTICIPANTS: Five male and five female adult subjects (age mean = 29...
October 14, 2016: Skeletal Radiology
Andrew J Coristine, Jerome Yerly, Matthias Stuber
BACKGROUND: Two-dimensional (2D) spatially selective radiofrequency (RF) pulses may be used to excite restricted volumes. By incorporating a "pencil beam" 2D pulse into a T2-Prep, one may create a "2D-T2-Prep" that combines T2-weighting with an intrinsic outer volume suppression. This may particularly benefit parallel imaging techniques, where artefacts typically originate from residual foldover signal. By suppressing foldover signal with a 2D-T2-Prep, image quality may therefore improve...
2016: PloS One
Rahul Gujrathi, Kanchan Gupta, Chetan Ravi, Bhujang Pai
BACKGROUND: Sciatica has been classically described as pain in the back and hip with radiation in the leg along the distribution of the sciatic nerve, secondary to compression or irritation of the sciatic nerve. Spinal abnormality being the most common etiology, is one of the most common indications for MRI of the lumbosacral spine. Here we describe imaging findings secondary to a supralevator perianal abscess causing irritation of the sciatic nerve, which was diagnosed on MRI of the lumbosacral spine...
2016: Polish Journal of Radiology
Andrea Romano, Valeria Coppola, Mariangela Lombardi, Luigi Lavorato, Domenica Di Stefano, Emanuela Caroli, Maria Camilla Rossi Espagnet, Francesca Tavanti, Giuseppe Minniti, Giuseppe Trillò, Alessandro Bozzao
PURPOSE: Our hypothesis was that pituitary macroadenomas show different areas of consistency detectable by enhanced magnetic resonance imaging (MRI) with Dynamic study during gadolinium administration. MATERIALS AND METHODS: We analysed 21 patients with pituitary macroadenomas between June 2013 and June 2015. All patients underwent trans-sphenoidal surgery and neurosurgeon described macroadenomas consistency. Similarly, two neuroradiologists manually drew regions of interest (ROIs) inside the solid-appearing portions of macroadenoma and in the normal white matter both on dynamic and post-contrast acquisitions...
October 11, 2016: Pituitary
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

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"