keyword
MENU ▼
Read by QxMD icon Read
search

MRA

keyword
https://www.readbyqxmd.com/read/28436571/enantioselective-access-to-robinson-annulation-products-to-michael-adducts-precursors-where-do-we-stand-after-80-years
#1
Florian Gallier, Arnaud Martel, Gilles Dujardin
The Robinson annulation is a reaction that has been useful for numerous syntheses since its discovery in 1935, especially in the field of the steroid synthesis. The products are usually obtained after 3 consecutive steps which are the formation of an enolate (or derivative), a conjugate addition and an aldol reaction. Over the years, several methodological improvements were made for each individual step or alternative routes were devised to access the Robinson annulation products. The first part of this review outlines the most relevant developments towards the formation of Monocarbonyl-derived Robinson Annulation Products (MRA Products, MRAP) and Activated Monocarbonyl-derived Robinson Annulation Products (AMRA Products, AMRAP)...
April 24, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28431954/isolated-intracranial-fibromuscular-dysplasia-of-the-posterior-cerebral-artery
#2
Min-Ju Yeo, Ho-Yeong Jeon, Min-Ju Cha, Hye-Yeon Jang, Sang-Gil Lee, Ji Seon Kim, Sung-Hyun Lee, Sang-Soo Lee, Dong-Ick Shin
Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory arterial disease that most commonly affects the renal and internal carotid arteries, but intracranial FMD is very rare. We report a patient with FMD involving the posterior cerebral arteries (PCAs). A 24year old female was presented with a 4day history of right homonymous hemianopsia with throbbing headache in the left temporo-occipital area. The brain magnetic resonance imaging (MRI) revealed an acute ischemic stroke in the left PCA territory, while the Time of Flight (TOF) magnetic resonance angiogram (MRA) showed segmental luminal irregularities in the left proximal PCA...
April 18, 2017: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
https://www.readbyqxmd.com/read/28422344/use-of-blood-pool-agents-with-steady-state-mri-to-assess-the-vascular-system
#3
Avnesh S Thakor, John Chung, Premal Patel, Anthony Chan, Amdad Ahmed, Graeme McNeil, David M Liu, Bruce Forster, Darren Klass
Over the past two decades there have been significant advances in the use of magnetic resonance imaging (MRI) to assess the vascular system. New imaging sequences and improvements in magnet design have enabled the creation of higher spatial resolution images. MRI is now a viable alternative imaging modality when compared to both invasive angiography and computed tomographic angiography. The use of blood pool agents has further facilitated the use of MR angiography (MRA); their high molecular weight allows for lower doses of contrast medium administration while their prolonged presence in the blood stream allows for repeated high-quality volumetric imaging of both the arterial and venous circulation...
April 19, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28419687/skeletal-muscle-analyses-agreement-between-non-contrast-and-contrast-ct-scan-measurements-of-skeletal-muscle-area-and-mean-muscle-attenuation
#4
Anne van der Werf, Ingeborg M Dekker, Martijn R Meijerink, Nicolette J Wierdsma, Marian A E de van der Schueren, Jacqueline A E Langius
Low skeletal muscle area (SMA) and muscle radiation attenuation (MRA) have been associated with poor prognosis in various patient populations. Both non-contrast and contrast CT scans are used to determine SMA and MRA. The effect of the use of a contrast agent on SMA and MRA is unknown. Therefore, we investigated agreement between these two scan options. SMA and MRA of 41 healthy individuals were analysed on a paired non-contrast and contrast single CT scan, and agreement between paired scan results was assessed with use of Bland-Altman plots, intraclass correlation coefficients (ICCs), standard error of measurements (SEM) and smallest detectable differences at a 95% confidence level (SDD95 )...
April 16, 2017: Clinical Physiology and Functional Imaging
https://www.readbyqxmd.com/read/28419357/stereoelectroencephalography-using-magnetic-resonance-angiography-for-avascular-trajectory-planning-technical-report
#5
Krasimir Minkin, Kaloyan Gabrovski, Marin Penkov, Yuri Todorov, Rositsa Tanova, Yoana Milenova, Kiril Romansky, Petia Dimova
BACKGROUND: Stereoelectroencephalography (SEEG) requires high-quality angiographic studies because avascular trajectory planning is a prerequisite for the safety of this procedure. Some epilepsy surgery groups have begun to use computed tomography angiography and magnetic resonance T1-weighted sequence with contrast enhancement for this purpose. OBJECTIVE: To present the first series of patients with avascular trajectory planning of SEEG based on magnetic resonance angiography (MRA)...
April 13, 2017: Neurosurgery
https://www.readbyqxmd.com/read/28415056/-pulsatile-tinnitus-due-to-an-aberrant-internal-carotid-artery-in-the-middle-ear-a-case-report
#6
Kazuyuki Kuwayama, Junichiro Satomi, Tadashi Yamaguchi, Izumi Yamaguchi, Shu Sogabe, Shotaro Yoshioka, Shinji Nagahiro
We report a rare case of aberrant internal carotid artery in the middle ear. The patient was a 30-year-old man with pulsatile tinnitus. MRA and 3D-CTA revealed an aberrant course of the internal carotid artery in the middle ear. 3D-CTA proved useful for radiographic diagnosis, leading to the observation of an aberrant internal carotid artery passing the foramen. We discuss the diagnosis and management of such patients.
April 2017: No Shinkei Geka. Neurological Surgery
https://www.readbyqxmd.com/read/28412828/magnetic-resonance-angiographic-study-of-anatomic-variations-of-the-circle-of-willis-in-a-population-in-tehran
#7
Bahman Jalali Kondori, Fateme Azemati, Sonia Dadseresht
BACKGROUND AND OBJECTIVES: The circle of Willis, an anastomotic polygon at the base of the brain, forms an important collateral network to maintain cerebral blood perfusion. The aim of this study was to investigate different anatomic variations of the circle of Willis and their prevalence. METHODS: This cross-sectional study was conducted on 525 healthy participants including 205 men and 320 women. The mean age of the patients was 51.5 years. Three-dimensional time-of-flight magnetic resonance angiography (3D-TOF MRA) technique was used...
April 2017: Archives of Iranian Medicine
https://www.readbyqxmd.com/read/28409175/ct-arthrography-of-adhesive-capsulitis-of-the-shoulder-are-mr-signs-applicable
#8
Cerny Milena, Omoumi Patrick, Larbi Ahmed, Manicourt Daniel, Perozziello Anne, Frederic E Lecouvet, Bruno C Vande Berg, Dallaudière Benjamin
OBJECTIVE: To determine if diagnostic signs of adhesive capsulitis (AC) of the shoulder at Magnetic Resonance Imaging (MRI) and arthrography (MRA) are applicable to CT arthrography (CTA). METHODS: 22 shoulder CTAs with AC were retrospectively reviewed for features described in MR literature. The control group was composed of 83 shoulder CTA divided into four subgroups 1) normal (N = 20), 2) omarthrosis (N = 19), 3) labral injury (N = 23), and 4) rotator cuff tear (N = 21)...
2017: European Journal of Radiology Open
https://www.readbyqxmd.com/read/28405834/feasibility-study-of-a-generalized-framework-for-developing-computer-aided-detection-systems-a-new-paradigm
#9
Mitsutaka Nemoto, Naoto Hayashi, Shouhei Hanaoka, Yukihiro Nomura, Soichiro Miki, Takeharu Yoshikawa
We propose a generalized framework for developing computer-aided detection (CADe) systems whose characteristics depend only on those of the training dataset. The purpose of this study is to show the feasibility of the framework. Two different CADe systems were experimentally developed by a prototype of the framework, but with different training datasets. The CADe systems include four components; preprocessing, candidate area extraction, candidate detection, and candidate classification. Four pretrained algorithms with dedicated optimization/setting methods corresponding to the respective components were prepared in advance...
April 12, 2017: Journal of Digital Imaging: the Official Journal of the Society for Computer Applications in Radiology
https://www.readbyqxmd.com/read/28401618/tailoring-mineralocorticoid-receptor-antagonist-therapy-in-heart-failure-patients-are-we-moving-towards-a-personalized-approach
#10
REVIEW
João Pedro Ferreira, Robert J Mentz, Anne Pizard, Bertram Pitt, Faiez Zannad
The aim of personalized medicine is to offer a tailored approach to each patient in order to provide the most effective therapy, while reducing risks and side effects. The use of mineralocorticoid receptor antagonists (MRAs) has demonstrated major benefits in heart failure with reduced ejection fraction (HFrEF), results with challenging inconsistencies in heart failure with preserved ejection fraction (HFpEF), and 'neutral' preliminary results in acute heart failure. Data derived from landmark trials are generally applied in a 'one size fits all' manner and the development and implementation of more personalized MRA management would offer the potential to improve outcomes and reduce side effects...
April 12, 2017: European Journal of Heart Failure
https://www.readbyqxmd.com/read/28400890/comparison-of-ethnic-specific-databases-in-heidelberg-retina-tomography-3-to-discriminate-between-early-glaucoma-and-normal-chinese-eyes
#11
Xiu Ling Tan, Sae Cheong Yap, Xiang Li, Leonard W Yip
PURPOSE: To compare the diagnostic accuracy of the 3 race-specific normative databases in Heidelberg Retina Tomography (HRT)-3, in differentiating between early glaucomatous and healthy normal Chinese eyes. METHOD: 52 healthy volunteers and 25 glaucoma patients were recruited for this prospective cross-sectional study. All underwent standardized interviews, ophthalmic examination, perimetry and HRT optic disc imaging. Area under the curve (AUC) receiver operating characteristics, sensitivity and specificity were derived to assess the discriminating abilities of the 3 normative databases, for both Moorfields Regression Analysis (MRA) and Glaucoma Probability Score (GPS)...
2017: Open Ophthalmology Journal
https://www.readbyqxmd.com/read/28399787/diagnostic-modalities-for-distal-radioulnar-joint
#12
S Jens, T Luijkx, F F Smithuis, M Maas
The first imaging modality in patients suspected of distal radioulnar joint pathology should be conventional radiography to exclude or diagnose wrist pathology including osteoarthritis, rheumatoid arthritis, calcium pyrophosphate deposition disease, (healed) fractures, or impaction syndromes. When conventional radiography is inconclusive, high resolution 3 Tesla magnetic resonance imaging is advised. We provide a broad overview of the literature regarding the use of intra-articular contrast both with computed tomography (CTA) or magnetic resonance imaging (MRA)...
May 2017: Journal of Hand Surgery, European Volume
https://www.readbyqxmd.com/read/28397151/identification-of-novel-atp7a-mutations-and-prenatal-diagnosis-in-chinese-patients-with-menkes-disease
#13
Binbin Cao, Xiaoping Yang, Yinyin Chen, Qionghui Huang, Ye Wu, Qiang Gu, Jiangxi Xiao, Huixia Yang, Hong Pan, Junya Chen, Yu Sun, Li Ren, Chengfeng Zhao, Yanhua Deng, Yanling Yang, Xingzhi Chang, Zhixian Yang, Yuehua Zhang, Zhengping Niu, Juli Wang, Xiru Wu, Jingmin Wang, Yuwu Jiang
Menkes disease (MD) is a fatal X-linked multisystem disease caused by mutations in ATP7A. In this study, clinical and genetic analysis was performed in 24 male MD patients. Development delay, seizures, kinky coarse hair, and dystonia were found in 24, 22, 24, and 24 patients, respectively. Serum ceruloplasmin/copper tested in 19 patients was low. Abnormal classic features of MD presented in the MRI/MRA of 19 patients. Seventeen mutations of ATP7A were identified in 22 patients. Twelve were novel mutations including three small deletion/insertion, one missense mutation, two nonsense mutations, three splicing-site mutations, and three gross deletions...
April 10, 2017: Metabolic Brain Disease
https://www.readbyqxmd.com/read/28396726/reporting-rotator-cuff-tears-on-magnetic-resonance-arthrography-using-the-snyder-s-arthroscopic-classification
#14
Alberto Aliprandi, Carmelo Messina, Paolo Arrigoni, Michele Bandirali, Giovanni Di Leo, Stefano Longo, Sandro Magnani, Chiara Mattiuz, Filippo Randelli, Silvana Sdao, Francesco Sardanelli, Luca Maria Sconfienza, Pietro Randelli
AIM: To determine diagnostic performance of magnetic resonance arthrography (MRA) in evaluating rotator cuff tears (RCTs) using Snyder's classification for reporting. METHODS: One hundred and twenty-six patients (64 males, 62 females; median age 55 years) underwent shoulder MRA and arthroscopy, which represented our reference standard. Surgical arthroscopic reports were reviewed and the reported Snyder's classification was recorded. MRA examinations were evaluated by two independent radiologists (14 and 5 years' experience) using Snyder's classification system, blinded to arthroscopy...
March 28, 2017: World Journal of Radiology
https://www.readbyqxmd.com/read/28394897/vertebral-artery-terminating-in-posterior-inferior-cerebellar-artery-a-normal-variation-with-clinical-significance
#15
I-Wen Liu, Bo-Lin Ho, Chien-Fu Chen, Ke Han, Chung-Jung Lin, Wen-Yung Sheng, Han-Hwa Hu, A-Ching Chao
A vertebral artery (VA) terminating in a posterior inferior cerebellar artery (PICA) is often considered to be a normal variation associated with VA hypoplasia. We aimed to investigate the clinical significance of this cerebrovascular variant. A total of 80 patients with clinically evident cerebrovascular events in posterior circulation were examined by duplex sonography and magnetic resonance angiography (MRA). Eighty healthy subjects who had MRA check-up were recruited as controls. PICA termination of the VA (PICA-VA) was identified as the VA not communicating with the basilar artery (BA) but ending into a PICA...
2017: PloS One
https://www.readbyqxmd.com/read/28393638/vascular-territorial-segmentation-and-volumetric-blood-flow-measurement-using-dynamic-contrast-enhanced-magnetic-resonance-angiography-of-the-brain
#16
Oren Geri, Shelly I Shiran, Jonathan Roth, Moran Artzi, Liat Ben-Sira, Dafna Ben Bashat
This study proposes a method for territorial segmentation and volumetric flow rate (VFR) distribution measurement of cerebral territories based on time-resolved contrast enhanced magnetic-resonance-angiography (MRA). The method uses an iterative region-growing algorithm based on bolus-arrival-time with increased temporal resolution. Eight territories were segmented: (1) right and (2) left internal carotid arteries, including the middle cerebral artery (ICA+MCA), excluding the anterior cerebral arteries (ACA); (3) right and left ACA (R+L-ACA); (4) right and (5) left external carotid arteries (ECA); (6) right and (7) left posterior cerebral arteries (PCA); and (8) vertebrobasilar territory...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28391537/virulence-factors-of-shiga-toxin-producing-escherichia-coli-and-the-risk-of-developing-haemolytic-uraemic-syndrome-in-norway-1992-2013
#17
U Naseer, I Løbersli, M Hindrum, T Bruvik, L T Brandal
Shiga toxin-producing Escherichia coli (STEC) may cause haemolytic uraemic syndrome (HUS). Age ≤5 years and presence of stx2a and eae are risk factors for the development of HUS. In this study, we investigated STEC isolates for the presence of adhesins, toxins and molecular risk assessment (MRA) factors to identify virulence genes associated with HUS development. We included non-duplicate isolates from all STEC infections (n = 340, HUS = 32) reported to the Norwegian National Reference Laboratory (NRL) for Enteropathogenic Bacteria from 1992 to 2013...
April 8, 2017: European Journal of Clinical Microbiology & Infectious Diseases
https://www.readbyqxmd.com/read/28388971/non-contrast-enhanced-navigator-gated-balanced-steady-state-free-precession-magnetic-resonance-angiography-as-a-preferred-magnetic-resonance-technique-for-assessment-of-the-thoracic-aorta
#18
F van Kesteren, M A Elattar, K P van Lienden, J Baan, H A Marquering, R N Planken
AIM: To compare the objective and subjective image quality of non-contrast three-dimensional (3D) navigator-gated balanced steady state free precession magnetic resonance angiography (NC-MRA) and contrast-enhanced magnetic resonance angiography (CE-MRA) along the entire thoracic aorta. MATERIALS AND METHODS: Fifty consecutive patients with thoracic aortic disease underwent NC-MRA and CE-MRA using a 1.5 T MRI system. Vessel sharpness was assessed using signal intensity profiles at five predefined levels of the thoracic aorta...
April 4, 2017: Clinical Radiology
https://www.readbyqxmd.com/read/28382736/vessel-mapping-for-dialysis-access-planning
#19
Vandana Dua Niyyar, Haimanot Wasse
The population of patients with end-stage renal disease (ESRD) in the United States is progressively increasing, with hemodialysis (HD) as the major mode of renal replacement therapy. National guidelines recommend increasing the use of arteriovenous fistulae (AVF) in both incident and prevalent hemodialysis patients. Pre-operative vascular mapping prior to the surgical creation of an AVF is now considered standard of care and may be helpful in achieving these goals. This manuscript focuses on the advantages and limitations of the various imaging techniques currently available for vessel mapping including physical examination, ultrasonography, angiography (iodinated contrast vs...
April 5, 2017: Seminars in Dialysis
https://www.readbyqxmd.com/read/28382536/follow-up-assessment-of-coiled-intracranial-aneurysms-using-zte-mra-as-compared-with-tof-mra-a-preliminary-image-quality-study
#20
Song'an Shang, Jing Ye, Xianfu Luo, Jianxun Qu, Yong Zhen, Jingtao Wu
OBJECTIVES: To prospectively assess coiled intracranial aneurysms using a novel non-contrast enhanced zero echo time (zTE) MR angiography (MRA) method, and compare its image quality with time-of-flight (TOF) MRA, using digital subtraction angiography (DSA) as reference. METHODS: Twenty-five patients (10 males and 15 females; age 53.96 ± 12.46 years) were enrolled in this monocentric study. MRA sequences were performed 24 h before DSA. Susceptibility artefact intensity and flow signal within the parent artery were carried out using a 4-point scale...
April 5, 2017: European Radiology
keyword
keyword
9662
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"