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https://www.readbyqxmd.com/read/28645697/clinical-high-resolution-mapping-of-the-proteoglycan-bound-water-fraction-in-articular-cartilage-of-the-human-knee-joint
#1
Mustapha Bouhrara, David A Reiter, Kyle W Sexton, Christopher M Bergeron, Linda M Zukley, Richard G Spencer
PURPOSE: We applied a recently introduced method to achieve clinically-feasible in-vivo mapping of the proteoglycan water fraction (PgWF) of human knee cartilage with improved spatial resolution and stability as compared to existing methods. MATERIAL AND METHODS: Multicomponent driven equilibrium single-pulse observation of T1 and T2 (mcDESPOT) datasets were acquired from the knees of two healthy young subjects and one older subject with previous knee injury. Each dataset was processed using Bayesian Monte Carlo (BMC) analysis incorporating a two-component tissue model...
June 20, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28644905/a-realistic-phantom-for-validating-mri-based-synthetic-ct-images-of-the-human-skull
#2
Abraam S Soliman, Levi Burns, Amir Owrangi, Young Lee, William Y Song, Greg Stanisz, Brige P Chugh
PURPOSE: To introduce a new realistic human skull phantom for the validation of synthetic CT images of cortical bone from ultra-short echo-time (UTE) sequences. METHODS AND MATERIALS: A human skull of an adult female was utilized as a realistic representation of skull cortical bone. The skull was stabilized in a special acrylic container and was filled with contrast agents that have T1 and T2 relaxation times similar to human brain. The phantom was MR scanned at 3T with UTE and T2 -weighted sequences, followed by CT...
June 23, 2017: Medical Physics
https://www.readbyqxmd.com/read/28644110/detailed-magnetic-resonance-imaging-features-of-a-case-series-of-primary-gliosarcoma
#3
Luísa Sampaio, Paulo Linhares, José Fonseca
Objective We aimed to characterise the magnetic resonance imaging (MRI) features of a case series of primary gliosarcoma, with the inclusion of diffusion-weighted imaging and perfusion imaging with dynamic susceptibility contrast MRI. Materials and methods We conducted a retrospective study of cases of primary gliosarcoma from the Pathology Department database from January 2006 to December 2014. Clinical and demographic data were obtained. Two neuroradiologists, blinded to diagnosis, assessed tumour location, signal intensity in T1 and T2-weighted images, pattern of enhancement, diffusion-weighted imaging and dynamic susceptibility contrast MRI studies on preoperative MRI...
January 1, 2017: Neuroradiology Journal
https://www.readbyqxmd.com/read/28642288/ferumoxytol-enhanced-magnetic-resonance-imaging-assessing-inflammation-after-myocardial-infarction
#4
Colin G Stirrat, Shirjel R Alam, Thomas J MacGillivray, Calum D Gray, Marc R Dweck, Jennifer Raftis, William Sa Jenkins, William A Wallace, Renzo Pessotto, Kelvin Hh Lim, Saeed Mirsadraee, Peter A Henriksen, Scott Ik Semple, David E Newby
OBJECTIVES: Macrophages play a central role in the cellular inflammatory response to myocardial infarction (MI) and predict subsequent clinical outcomes. We aimed to assess temporal changes in cellular inflammation and tissue oedema in patients with acute MI using ultrasmallsuperparamagnetic particles of iron oxide (USPIO)-enhanced MRI. METHODS: Thirty-one patients were recruited following acute MI and followed up for 3 months with repeated T2 and USPIO-enhanced T2*-mapping MRI...
June 22, 2017: Heart: Official Journal of the British Cardiac Society
https://www.readbyqxmd.com/read/28639264/magnetic-resonance-spin-spin-relaxation-time-estimation-in-a-rat-model-of-fatty-liver-disease
#5
Sami Alghamdi, Benjamin Sinclair, Gary Cowin, Ian Brereton, Yasvir A Tesiram
PURPOSE: To compare mono- and bi-exponential relaxation model equations to discriminate between normal and fatty liver disease. MATERIALS AND METHODS: Six rats on a choline deficient amino acid modified (CDAA) diet and six on normal chow were studied. Multiple spin echo images with increasing echo times (TEs) were collected at 9.4T. Pixel-wise T2 maps were generated using mono-exponential decay function to calculate T2M , and a bi-exponential to calculate, short T2 component (T2S ), long T2 component (T2L ), and fractions of these components (ρS , ρL ), respectively...
June 22, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28639049/multiparametric-voxel-based-analyses-of-standardized-uptake-values-and-apparent-diffusion-coefficients-of-soft-tissue-tumours-with-a-positron-emission-tomography-magnetic-resonance-system-preliminary-results
#6
Koji Sagiyama, Yuji Watanabe, Ryotaro Kamei, Sungtak Hong, Satoshi Kawanami, Yoshihiro Matsumoto, Hiroshi Honda
OBJECTIVES: To investigate the usefulness of voxel-based analysis of standardized uptake values (SUVs) and apparent diffusion coefficients (ADCs) for evaluating soft-tissue tumour malignancy with a PET/MR system. METHODS: Thirty-five subjects with either ten low/intermediate-grade tumours or 25 high-grade tumours were prospectively enrolled. Zoomed diffusion-weighted and fluorodeoxyglucose ((18)FDG)-PET images were acquired along with fat-suppressed T2-weighted images (FST2WIs)...
June 20, 2017: European Radiology
https://www.readbyqxmd.com/read/28633793/treatment-of-a-focal-articular-cartilage-defect-of-the-talus-with-polymer-based-autologous-chondrocyte-implantation-a-12-year-follow-up-period
#7
Peter Cornelius Kreuz, Richard Horst Kalkreuth, Philipp Niemeyer, Markus Uhl, Christoph Erggelet
Autologous chondrocyte implantation (ACI) is a first-line treatment option for large articular cartilage defects. Although well-established for cartilage defects in the knee, studies of the long-term outcomes of matrix-assisted ACI to treat cartilage defects in the ankle are rare. In the present report, we describe for the first time the long-term clinical and radiologic results 12 years after polymer-based matrix-assisted ACI treat a full-thickness talar cartilage defect in a 25-year-old male patient. The clinical outcome was assessed using the visual analog scale and Freiburg ankle score, magnetic resonance imaging evaluation using the Henderson-Kreuz scoring system and T2 mapping...
July 2017: Journal of Foot and Ankle Surgery: Official Publication of the American College of Foot and Ankle Surgeons
https://www.readbyqxmd.com/read/28631203/assessment-of-mri-contrast-agent-concentration-by-quantitative-susceptibility-mapping-qsm-application-to-estimation-of-cerebral-blood-volume-during-steady-state
#8
Emelie Lind, Linda Knutsson, Robin Kämpe, Freddy Ståhlberg, Ronnie Wirestam
OBJECTIVE: One major issue in dynamic susceptibility contrast MRI (DSC-MRI) is to accurately determine contrast agent (CA) concentration, since T2* relaxivity in vivo is generally unknown and varies between blood and tissue. In this study, quantitative susceptibility mapping (QSM) was used for quantification of CA concentration. MATERIALS AND METHODS: A DSC-MRI protocol, including phase data acquisition, was applied to 20 healthy volunteers in a test-retest study...
June 19, 2017: Magma
https://www.readbyqxmd.com/read/28629954/high-resolution-myelin-water-imaging-incorporating-local-tissue-susceptibility-analysis
#9
Zhe Wu, Hongjian He, Yi Sun, Yiping Du, Jianhui Zhong
Quantitative myelin water imaging (MWI) from signal T2* decay acquired with multiple Gradient-Recalled Echo (mGRE) sequence has been widely used since its first report. A recent study showed that with low resolution data (2mm isotropic voxels), direct application of complex fitting to a three-pool WM model with frequency shift terms could produce more stable parameter estimation for myelin water fraction mapping. MWI maps of higher spatial resolution resulting in more detailed tissue structures and reduced partial volume effects around white matter/gray matter (WM/GM) interface, however, is more desirable...
June 16, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28619111/two-minute-disconnection-technique-with-a-double-lumen-tube-to-speed-the-collapse-of-the-non-ventilated-lung-for-one-lung-ventilation-in-thoracoscopic-surgery
#10
Qiongzhen Li, Xiaofeng Zhang, Jingxiang Wu, Meiying Xu
BACKGROUND: Thoracic surgery requires the effective collapse of the non-ventilated lung. In the majority of cases, we accomplished, accelerated lung collapse using a double-lumen tube (DLT). We hypothesized that using the two-minute disconnection technique with a DLT would improve lung collapse during subsequent one-lung ventilation. METHODS: Fifty patients undergoing thoracoscopic surgery with physical classification I or II according to the American Society of Anesthesiologists were randomly divided into two groups for respiratory management of one-lung ventilation (OLV)...
June 15, 2017: BMC Anesthesiology
https://www.readbyqxmd.com/read/28617723/effect-of-uterine-fundal-pressure-on-maternal-intraocular-pressure-in-cesarean-delivery-comparison-of-regional-and-general-anesthesia
#11
Aysun Kurtay, Esra Ozayar, Handan Gulec, Gokhan Yildiz, Esra Turkyilmaz, Zennure Yildiz, Eyup Horasanli
PURPOSE: To evaluate the intraocular pressure (IOP) changes accompanying fundal pressure during a cesarean-section procedure under both regional and general anesthesia. METHODS: In total, 60 women scheduled for elective cesarean section, none of them diagnosed with ocular problems, were enrolled in the study. Patients underwent cesarean section under either general (group G, n=30) or regional anesthesia (group S, n=30) according to their choice. IOP was measured with a Tono-Pen before (T1) and after (T2) application of anesthesia, during fundal pressure (T3), and after the birth of the baby (T4)...
June 14, 2017: Journal of Glaucoma
https://www.readbyqxmd.com/read/28614221/correlation-of-mdr1-gene-polymorphisms-with-anesthetic-effect-of-sevoflurane-remifentanil-following-pediatric-tonsillectomy
#12
Nian-Jun Shi, Wei-Xia Zhang, Ning Zhang, Li-Na Zhong, Ling-Ping Wang
BACKGROUND: The motive of this study was to investigate the collaboration between MDR1 gene polymorphisms and anesthetic effects following pediatric tonsillectomy. METHODS: All together 178 children undergoing tonsillectomy with preoperative sevoflurane-remifentanil anesthesia were selected. In order to determine MDR1 gene polymorphisms of 3435C > T, 1236C > T, and 2677G > T/A, polymerase chain reaction-restriction fragment length polymorphism was used...
June 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28611637/a-case-of-posterior-reversible-encephalopathy-syndrome-induced-by-cisplatin-pemetrexed-chemotherapy-for-lung-cancer
#13
Masashi Ishihara, Noriyuki Matsutani, Shuji Ota, Nobuhiko Seki
This report presents the case of a 60-year-old woman who was diagnosed with stage IV lung adenocarcinoma with asymptomatic brain metastases and commenced chemotherapy with cisplatin/pemetrexed (CDDP/Pem). She experienced tonic-clonic convulsions on day 9 of the first cycle, which were accompanied by increased blood pressure (173/69 mm Hg) and headache. Therefore, brain MRI was performed to check for stroke or progression of brain metastatic foci. T2-weighted, FLAIR, and ADC map images showed high-intensity areas in the subcortical region of the bilateral parieto-occipital lobes, leading to a diagnosis of posterior reversible encephalopathy syndrome (PRES)...
January 2017: Case Reports in Oncology
https://www.readbyqxmd.com/read/28606578/a-case-of-ecchordosis-physaliphora-in-the-prepontine-cistern-a-rare-entity-in-the-differential-diagnosis-of-an-epidermoid-cyst
#14
Kenji Miki, Koji Yoshimoto, Ataru Nishimura, Satoshi O Suzuki, Akio Hiwatashi, Koji Iihara
BACKGROUND: Ecchordosis physaliphora (EP) is a benign notochordal remnant, which is usually asymptomatic. Herein, we report a case of symptomatic large EP mimicking an epidermoid cyst. CASE DESCRIPTION: A 44-year-old female presented with right facial dysesthesia. Brain magnetic resonance imaging (MRI) showed a mass with a diameter of 3.2 cm that was hypointense on T1-weighted images (T1WI), hyperintense on T2-weighted images (T2WI), iso-to-hyperintense on diffusion-weighted (DW) images, and hyperintense on apparent diffusion coefficient (ADC) map (1...
June 9, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28604062/cartilage-regeneration-in-full-thickness-patellar-chondral-defects-treated-with-particulated-juvenile-articular-allograft-cartilage-an-mri-analysis
#15
Brian Grawe, Alissa Burge, Joseph Nguyen, Sabrina Strickland, Russell Warren, Scott Rodeo, Beth ShubinStein
Background Full-thickness cartilage lesions of the patella represent a common source of pain and dysfunction. Previously reported surgical treatment options include marrow stimulation, cell-based treatments, and osteochondral transfer. Minced juvenile allograft cartilage is a novel treatment option that allows for a single stage approach for these lesions. Hypothesis Particulated juvenile allograft cartilage (PJAC) for the treatment of chondral defects of the patella would offer acceptable lesion fill rates, mature over time, and not be associated with any negative biologic effects on the surrounding tissue...
June 1, 2017: Cartilage
https://www.readbyqxmd.com/read/28602814/quantitative-in-vivo-t2-mapping-using-fast-spin-echo-techniques-a-linear-correction-procedure
#16
Ulrike Nöth, Manoj Shrestha, Jan-Rüdiger Schüre, Ralf Deichmann
A method is presented for correcting the effects of stimulated and indirect echoes on quantitative T2 mapping data acquired with multiple spin echo techniques, such as turbo spin echo. In contrast to similar correction techniques proposed in the literature, the method does not require a priori knowledge of the radio frequency (RF) pulse profiles. In a first step, for the T2 mapping protocol under investigation, signal decay curves S(TE) are simulated for a range of different RF pulse profiles. The actual signal decay S(TE) is then measured on a phantom with known T2, so the approximate RF pulse profiles can be derived via comparison with the simulated decay curves...
June 9, 2017: NeuroImage
https://www.readbyqxmd.com/read/28602813/automated-segmentation-of-midbrain-structures-with-high-iron-content
#17
REVIEW
Benjamín Garzón, Rouslan Sitnikov, Lars Bäckman, Grégoria Kalpouzos
The substantia nigra (SN), the subthalamic nucleus (STN), and the red nucleus (RN) are midbrain structures of ample interest in many neuroimaging studies, which may benefit from the availability of automated segmentation methods. The high iron content of these structures awards them high contrast in quantitative susceptibility mapping (QSM) images. We present a novel segmentation method that leverages the information of these images to produce automated segmentations of the SN, STN, and RN. The algorithm builds a map of spatial priors for the structures by non-linearly registering a set of manually-traced training labels to the midbrain...
June 9, 2017: NeuroImage
https://www.readbyqxmd.com/read/28601627/effects-of-small-dose-dexmedetomidine-on-hyperdynamic-responses-to-electroconvulsive-therapy
#18
Xiang Li, Fang Tan, Chao-Jun Jian, Na Guo, Zhi-Yong Zhong, Zi-Qing Hei, Shao-Li Zhou
BACKGROUND: Acute hemodynamic responses to electroconvulsive therapy (ECT) may increase the risk of cardiovascular complications in vulnerable patients. The aim of the current study was to assess the effect of small-dose dexmedetomidine on hyperdynamic responses to ECT. METHODS: Seventy-eight patients were enrolled and randomly allocated to receive either 0.2 μg/kg dexmedetomidine (Dex group, n = 39) or saline (Control group, n = 39) prior to ECT. Heart rate (HR) and mean arterial pressure (MAP) were recorded immediately after the administration of dexmedetomidine (T1), and 0, 1, 3, 5 and 10 min after the electrical stimuli ended (T2, T3, T4, T5 and T6)...
June 7, 2017: Journal of the Chinese Medical Association: JCMA
https://www.readbyqxmd.com/read/28599415/value-of-diffusion-weighted-magnetic-resonance-imaging-in-predicting-world-health-organization-grade-in-g1-g2-pancreatic-neuroendocrine-tumors
#19
Chuangen Guo, Xiaoling Zhuge, Xiao Chen, Zhongqiu Wang, Wenbo Xiao, Qidong Wang
The present study aimed to investigate the value of diffusion-weighted magnetic resonance imaging (DWI) in the grading of well-differentiated pancreatic neuroendocrine tumors (PanNETs). A total of 44 patients with histologically proven well-differentiated PanNET [grade 1 (G1) and grade 2 (G2) according to the World Health Organization (WHO) criteria] underwent pretreatment magnetic resonance imaging (MRI), which was retrospectively analyzed. The location, size, cystic or solid appearance, boundary, presence or absence of tumor contrast enhancement, and MRI signal of the tumor were assessed...
June 2017: Oncology Letters
https://www.readbyqxmd.com/read/28590821/t2-mapping-of-the-sacroiliac-joints-with-3-t-mri-a-preliminary-study
#20
Guillaume Lefebvre, Antonin Bergère, Mazen El Rafei, Alain Duhamel, Pedro Teixeira, Anne Cotten
OBJECTIVE: The objective of this study was to assess the feasibility of T2 relaxation time measurements of the sacroiliac joints. SUBJECTS AND METHODS: The sacroiliac joints of 40 patients were imaged by 3-T MRI using an oblique axial multislice multiecho spin-echo T2-weighted sequence. Manual plotting and automatic subdivision of ROIs allowed us to obtain T2 values for up to 48 different areas per patient (posterior and anterior parts, sacral, intermediate, and iliac parts)...
June 7, 2017: AJR. American Journal of Roentgenology
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