keyword
MENU ▼
Read by QxMD icon Read
search

Mri sequence

keyword
https://www.readbyqxmd.com/read/28437634/convolutional-neural-network-regression-for-short-axis-left-ventricle-segmentation-in-cardiac-cine-mr-sequences
#1
Li Kuo Tan, Yih Miin Liew, Einly Lim, Robert A McLaughlin
Automated left ventricular (LV) segmentation is crucial for efficient quantification of cardiac function and morphology to aid subsequent management of cardiac pathologies. In this paper, we parameterize the complete (all short axis slices and phases) LV segmentation task in terms of the radial distances between the LV centerpoint and the endo- and epicardial contours in polar space. We then utilize convolutional neural network regression to infer these parameters. Utilizing parameter regression, as opposed to conventional pixel classification, allows the network to inherently reflect domain-specific physical constraints...
April 12, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28436842/a-hybrid-image-registration-and-matching-framework-for-real-time-motion-tracking-in-mri-guided-radiotherapy
#2
Matteo Seregni, Chiara Paganelli, Paul Summers, Massimo Bellomi, Guido Baroni, Marco Riboldi
OBJECTIVE: MRI-guided radiotherapy (MRIgRT) is an emerging treatment technique where anatomical and pathological structures are imaged through integrated MR-radiotherapy units. This work aims (i) at assessing the accuracy of optical-flow based motion tracking in liver cine-MRI sequences and (ii) at testing a MRIgRT workflow combining similarity-based image matching with image registration. METHODS: After an initialization stage, a set of template images is collected and registered to the first frame of the cine-MRI sequence...
April 24, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28436752/quantitative-mr-imaging-of-intra-orbital-structures-tissue-specific-measurements-and-age-dependency-compared-to-extra-orbital-structures-using-multispectral-quantitative-mr-imaging
#3
Memi Watanabe, Karen Buch, Akifumi Fujita, Hernán Jara, Muhammad Mustafa Qureshi, Osamu Sakai
The orbit can be affected by unique pathologic conditions and often requires MRI evaluation. The purpose of this study was to investigate the age-related changes in multiple intra-orbital structures using quantitative MRI (qMRI). Thirty-eight subjects (20 males, 18 females; ages 0.5-87 years) underwent MRI with a mixed turbo spin echo sequence. T1 and T2 measurements were obtained within ROI in 6 intra-orbital structures (medial and lateral rectus muscles, medial and lateral retrobulbar fat, lacrimal gland, and optic nerve), and compared with those of corresponding extra-orbital structures (masseter muscle, subcutaneous cheek fat, buccal fat, parotid gland, and frontal white matter)...
April 24, 2017: Orbit
https://www.readbyqxmd.com/read/28435103/magnetization-transfer-contrast-and-chemical-exchange-saturation-transfer-mri-features-and-analysis-of-the-field-dependent-saturation-spectrum
#4
Peter C M van Zijl, Wilfred W Lam, Jiadi Xu, Linda Knutsson, Greg J Stanisz
Magnetization Transfer Contrast (MTC) and Chemical Exchange Saturation Transfer (CEST) experiments measure the transfer of magnetization from molecular protons to the solvent water protons, an effect that becomes apparent as an MRI signal loss ("saturation"). This allows molecular information to be accessed with the enhanced sensitivity of MRI. In analogy to Magnetic Resonance Spectroscopy (MRS), these saturation data are presented as a function of the chemical shift of participating proton groups, e.g. OH, NH, NH2, which is called a Z-spectrum...
April 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/28434952/motor-outcomes-after-surgical-resection-of-lesions-involving-the-motor-pathway-a-prognostic-evaluation-scale
#5
Antonino Raco, Alessandro Pesce, Flavia Fraschetti, Alessandro Frati, Giancarlo D'Andrea, Marco Cimatti, Michele Acqui
BACKGROUND: Preservation of functions is essential in surgical resection of lesions involving the motor pathways. The aim of this work is to evaluate the effect of anatomical features of lesions located in the motor pathway on neurological and functional outcome. The authors propose an evaluation score in order to assess the risk of postoperative worsening. METHODS: 92 patients suffering from lesions involving the motor pathways have been studied for what concerns motor functions (MRC) after surgical treatment...
April 18, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28434064/the-utility-of-ct-and-mri-in-detecting-male-urethral-recurrence-after-radical-cystectomy
#6
Jung Jae Park, Byung Kwan Park
PURPOSE: To evaluate the utility of computed tomography (CT) and magnetic resonance imaging (MRI) in detecting male urethral recurrence (UR). MATERIALS AND METHODS: Between December 2008 and March 2016, 12 men (age range 61-85 years; median, 74 years) with urethral bloody discharge or pain were histologically confirmed as UR after radical cystectomy due to urothelial carcinoma. Of these patients, eight underwent both CT and MRI. The remaining four patients underwent CT only...
April 22, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/28433970/simultaneous-transient-global-amnesia-and-right-mca-stroke-after-valsalva-manoeuvre
#7
Ariel Fernando Mariaca, Jose Manuel Valdueza, Christian Gaebel, Manuel Gomez-Choco
A 61-year-old man suffered an episode of transient confusion and anterograde amnesia after a Valsalva-related manoeuvre. The MRI diffusion weighted imaging (DWI) sequences showed a left hippocampal and two right parietal lesions that were deemed as acute. The MR angiography disclosed a high-grade stenosis in the right middle cerebral artery as was described by a transcranial colour-coded ultrasound as well. Ultrasound investigation of the jugular veins showed a right jugular venous reflux after a Valsalva manoeuvre...
April 22, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28432780/single-subject-independent-component-analysis-based-intensity-normalization-in-non-quantitative-multi-modal-structural-mri
#8
Sebastian Papazoglou, Jens Würfel, Friedemann Paul, Alexander U Brandt, Michael Scheel
Non-quantitative MRI is prone to intersubject intensity variation rendering signal intensity level based analyses limited. Here, we propose a method that fuses non-quantitative routine T1-weighted (T1w), T2w, and T2w fluid-saturated inversion recovery sequences using independent component analysis and validate it on age and sex matched healthy controls. The proposed method leads to consistent and independent components with a significantly reduced coefficient-of-variation across subjects, suggesting potential to serve as automatic intensity normalization and thus to enhance the power of intensity based statistical analyses...
April 22, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28432505/3d-double-echo-steady-state-sequence-assessment-of-hip-joint-cartilage-and-labrum-at-3-tesla-comparative-analysis-of-magnetic-resonance-imaging-and-intraoperative-data
#9
Christoph Schleich, Tobias Hesper, Harish S Hosalkar, Fanni Rettegi, Christoph Zilkens, Rüdiger Krauspe, Gerald Antoch, Bernd Bittersohl
OBJECTIVES: To assess the diagnostic accuracy of a high-resolution, three-dimensional (3D) double-echo steady-state (DESS) sequence with radial imaging at 3 Tesla (T) for evaluating cartilage and labral alterations in the hip. METHODS: Magnetic resonance imaging (MRI) data obtained at 3 T, including radially reformatted DESS images and intraoperative data of 45 patients (mean age 42 ± 13.7 years) who underwent hip arthroscopy, were compared. The acetabular cartilage and labrum of the upper hemisphere of the acetabulum and the central femoral head cartilage were evaluated...
April 21, 2017: European Radiology
https://www.readbyqxmd.com/read/28432504/3t-mri-of-the-knee-with-optimised-isotropic-3d-sequences-accurate-delineation-of-intra-articular-pathology-without-prolonged-acquisition-times
#10
Osamah M Abdulaal, Louise Rainford, Peter MacMahon, Eoin Kavanagh, Marie Galligan, James Cashman, Allison McGee
OBJECTIVES: To investigate optimised isotropic 3D turbo spin echo (TSE) and gradient echo (GRE)-based pulse sequences for visualisation of articular cartilage lesions within the knee joint. METHODS: Optimisation of experimental imaging sequences was completed using healthy volunteers (n=16) with a 3-Tesla (3T) MRI scanner. Imaging of patients with knee cartilage abnormalities (n=57) was then performed. Acquired sequences included 3D proton density-weighted (PDW) TSE (SPACE) with and without fat-suppression (FS), and T2*W GRE (TrueFISP) sequences, with acquisition times of 6:51, 6:32 and 5:35 min, respectively...
April 21, 2017: European Radiology
https://www.readbyqxmd.com/read/28432404/pediatric-neuro-mri-tricks-to-minimize-sedation
#11
REVIEW
Matthew J Barkovich, Duan Xu, Rahul S Desikan, Cassandra Williams, A James Barkovich
Magnetic resonance imaging (MRI) is the workhorse modality in pediatric neuroimaging because it provides excellent soft-tissue contrast without ionizing radiation. Until recently, studies were uninterpretable without sedation; however, given development of shorter sequences, sequences that correct for motion, and studies showing the potentially deleterious effects of sedation on immature laboratory animals, it is prudent to minimize sedation when possible. This manuscript provides basic guidelines for performing pediatric neuro MRI without sedation by both modifying technical factors to reduce scan time and noise, and using a multi-disciplinary team to coordinate imaging with the patient's biorhythms...
April 22, 2017: Pediatric Radiology
https://www.readbyqxmd.com/read/28431804/prognostic-value-of-dynamic-mri-positive-enhancement-integral-color-mapping-in-osteosynthesis-of-undisplaced-femoral-neck-fractures
#12
Masatoshi Morimoto, Yoshinori Takahashi, Takahiro Kubo, Kosuke Sugiura, Yasuaki Tamaki, Shunichi Toki, Katsuyoshi Suganuma, Kazumasa Inoue, Keisuke Adachi, Takashi Chikawa, Koichi Sairyo, Akihiro Nagamachi
AIMS: The common treatment for an undisplaced femoral neck fracture is osteosynthesis. Two major complications of osteosynthesis are non-union and late collapse of the femoral head. We speculated that femoral head perfusion is one of the most important factors that affect the outcome of osteosynthesis after femoral neck fracture. We have preoperatively estimated femoral head perfusion by dynamic MRI positive enhancement integral color mapping (PEICM). The purpose of this study was to evaluate the outcomes of undisplaced femoral neck fractures based on PEICM...
April 18, 2017: Journal of Orthopaedic Science: Official Journal of the Japanese Orthopaedic Association
https://www.readbyqxmd.com/read/28431612/xeroderma-pigmentosum-complementation-group-f-a-rare-cause-of-cerebellar-ataxia-with-chorea
#13
G Carré, C Marelli, M Anheim, C Geny, M Renaud, H R Rezvani, M Koenig, C Guissart, C Tranchant
The complementation group F of Xeroderma pigmentosum (XP-F) is rare in the Caucasian population, and usually devoid of neurological symptoms. We report two cases, both Caucasian, who exhibited progressive cerebellar ataxia, chorea, a mild subcortical frontal cognitive impairment, and in one case severe polyneuropathy. Brain MRI demonstrated cerebellar (2/2) and cortical (1/2) atrophy. Both patients had only mild sunburn sensitivity and no skin cancer. Mini-exome sequencing approach revealed in ERCC4, two heterozygous mutations, one of which was never described (c...
May 15, 2017: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/28431589/t2-relaxometry-helps-prognosticate-seizure-outcome-in-patients-with-solitary-cerebral-cysticercosis
#14
Aaron de Souza, Atchayaram Nalini, Jitender Saini, Kandavel Thennarasu
OBJECTIVE: Correlate serial T2 relaxometry (T2R) values with long term seizure outcome in patients with solitary cerebral cysticercosis (SCC) in order to establish its usefulness as a prognostic marker in these patients. METHODS: Patients with new-onset seizures due to SCC were imaged serially using a pre-determined MRI protocol at enrolment and after 3, 6, 12 and 24months. T2 relaxometry was performed using a dual echo sequence with maps generated manually from the measured image intensities at the level of the lesion...
May 15, 2017: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/28430716/simultaneous-multislice-accelerated-turbo-spin-echo-magnetic-resonance-imaging-comparison-and-combination-with-in-plane-parallel-imaging-acceleration-for-high-resolution-magnetic-resonance-imaging-of-the-knee
#15
Jan Fritz, Benjamin Fritz, Jialu Zhang, Gaurav K Thawait, Dharmdev H Joshi, Li Pan, Dingxin Wang
PURPOSE: We prospectively quantified the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of integrated parallel acquisition technique (PAT) and simultaneous multislice (SMS) acceleration and various combinations thereof, and we further compared two 4-fold-accelerated (PAT2-SMS2) high-resolution turbo spin echo (TSE) magnetic resonance imaging (MRI) protocols of the knee against a clinical 2-fold-accelerated (PAT2-SMS1) TSE standard. MATERIALS AND METHODS: Institutional review board approval was obtained, and all subjects gave informed consent...
April 20, 2017: Investigative Radiology
https://www.readbyqxmd.com/read/28429859/aneurysms-in-neurofibromatosis-type-2-evidence-for-vasculopathy
#16
Shazia K Afridi, Suki Thomson, Steve E J Connor, Daniel C Walsh, Rosalie E Ferner
There have been anecdotal reports of vasculopathy associated with Neurofibromatosis Type 2 (NF2). Given the increasing use of bevacizumab, a vascular endothelial growth factor inhibitor which results in an increased risk of bleeding, it is important to ascertain if there is a predisposition to vascular abnormalities in NF2. In our unit NF2 patients undergo annual MRI brain and internal auditory meatus imaging. We noted incidental intracranial aneurysms in some patients and sought to determine the prevalence of intracranial aneurysms in our cohort of NF2 patients...
April 21, 2017: American Journal of Medical Genetics. Part A
https://www.readbyqxmd.com/read/28429638/an-unusual-presentation-of-a-cervical-paraspinal-leiomyoma-in-an-adolescent-female
#17
Jeffrey A Swarz, Arayamparambil C Anilkumar, Douglas C Miller, N Scott Litofsky, Tomoko Tanaka
Objective We describe an apparently unique case of an extra-uterine leiomyoma in the cervical paraspinus including its evaluation and management. Methods A 14-year-old girl was referred to the neurology clinic for an abnormal head CT following a concussion. MRI revealed a homogenously enhancing left cervical paraspinal mass. The patient underwent complete resection and subsequent genetic testing and counseling were obtained to determine the presence of Li-Fraumeni Syndrome (LFS) or Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC) mutations...
January 1, 2017: Pediatric and Developmental Pathology
https://www.readbyqxmd.com/read/28429055/diagnostic-value-of-fourth-generation-iterative-reconstruction-algorithm-with-low-dose-ct-protocol-in-assessment-of-mesorectal-fascia-invasion-in-rectal-cancer-comparison-with-magnetic-resonance
#18
Davide Ippolito, Silvia Girolama Drago, C R Talei Franzesi, Alessandra Casiraghi, Sandro Sironi
PURPOSE: The purpose of the article is to compare the diagnostic performance about radiation dose and image quality of low-dose CT with iterative reconstruction algorithm (iDose4) and standard-dose CT in the assessment of mesorectal fascia (MRF) invasion in rectal cancer patients. MATERIALS AND METHODS: Ninety-one patients with biopsy-proven primary rectal adenocarcinoma underwent CT staging: 42 underwent low-dose CT, 49 underwent standard CT protocol. Low-dose contrast-enhanced MDCT scans were performed on a 256 (ICT, Philips) scanner using 120 kV, automated mAs modulation, iDose4 iterative reconstruction algorithm...
April 20, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/28428977/19th-workshop-of-the-international-stroke-genetics-consortium-april-28-29-2016-boston-massachusetts-usa-2016-001-mri-defined-cerebrovascular-genomics-the-charge-consortium
#19
S Debette, Y Saba, D Vojinovic, X Jian, H Adams, G Chauhan, M Sargurupremraj, S Kaffashian, J Ding, J C Bis, P Nyquist, K Mather, C Van Duijn, L J Launer, M A Ikram, H Schmidt, W T Longstreth, M Fornage, S Seshadri
The CHARGE consortium is an investigator-initiated collaboration to facilitate meta-analyses of genome-wide association studies (GWAS) and genomic analyses based on next generation sequencing (NGS), among multiple large and well-phenotyped population-based cohort studies around the world (http://www.chargeconsortium.com). Within the neuro-CHARGE working group, we are presenting an update of ongoing genomic studies on MRI-markers of cerebrovascular disease. Large population-based studies have shown that the burden of cerebrovascular disease extends far beyond that of clinical stroke...
March 2017: Neurology. Genetics
https://www.readbyqxmd.com/read/28428213/clinically-feasible-microstructural-mri-to-quantify-cervical-spinal-cord-tissue-injury-using-dti-mt-and-t2-weighted-imaging-assessment-of-normative-data-and-reliability
#20
A R Martin, B De Leener, J Cohen-Adad, D W Cadotte, S Kalsi-Ryan, S F Lange, L Tetreault, A Nouri, A Crawley, D J Mikulis, H Ginsberg, M G Fehlings
BACKGROUND AND PURPOSE: DTI, magnetization transfer, T2*-weighted imaging, and cross-sectional area can quantify aspects of spinal cord microstructure. However, clinical adoption remains elusive due to complex acquisitions, cumbersome analysis, limited reliability, and wide ranges of normal values. We propose a simple multiparametric protocol with automated analysis and report normative data, analysis of confounding variables, and reliability. MATERIALS AND METHODS: Forty healthy subjects underwent T2WI, DTI, magnetization transfer, and T2*WI at 3T in <35 minutes using standard hardware and pulse sequences...
April 20, 2017: AJNR. American Journal of Neuroradiology
keyword
keyword
85459
1
2
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"