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https://www.readbyqxmd.com/read/28634512/diffusion-weighted-imaging-for-the-detection-and-evaluation-of-cholesteatoma
#1
REVIEW
Benjamin Henninger, Christian Kremser
Cholesteatoma is a collection of keratinous debris and stratified squamous epithelium. It is trapped in the middle ear and can lead to bony erosion. The disease is treated surgically often followed by a second-look procedure to check for residual tissue or recurrence. Cholesteatoma has specific signal-intensity characteristics on magnetic resonance imaging with very high signal intensity on diffusion weighted imaging (DWI). Various DWI techniques exist: Echo-planar imaging (EPI)-based and non-EPI-based techniques as well as new approaches like multi-shot EPI DWI...
May 28, 2017: World Journal of Radiology
https://www.readbyqxmd.com/read/28629572/3t-diffusion-weighted-mri-in-the-response-assessment-of-colorectal-liver-metastases-after-chemotherapy-correlation-between-adc-value-and-histological-tumour-regression-grading
#2
Francescamaria Donati, Piero Boraschi, Federica Pacciardi, Rosa Cervelli, Maura Castagna, Lucio Urbani, Fabio Falaschi, Davide Caramella
PURPOSE: The purpose of the study was to correlate the apparent diffusion coefficient (ADC) values of diffusion-weighted MR imaging (DW-MRI) by 3T device with the histological tumour regression grading (TRG) analysis of colorectal liver metastases after preoperative chemotherapy. MATERIALS AND METHODS: Our study included thirty-five patients with colorectal liver metastases who had undergone MRI by 3T device (GE DISCOVERY MR750; GE Healthcare) after preoperative chemotherapy...
June 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28627984/diagnostic-accuracy-of-proton-magnetic-resonance-spectroscopy-and-perfusion-weighted-imaging-in-brain-gliomas-follow-up-a-single-institutional-experience
#3
Monica Anselmi, Alessia Catalucci, Valentina Felli, Valentina Vellucci, Alessandra Di Sibio, Giovanni Luca Gravina, Mario Di Staso, Ernesto Di Cesare, Carlo Masciocchi
Objectives The objective of this study was to evaluate whether proton magnetic resonance spectroscopy and perfusion magnetic resonance imaging (MRI) are able to increase diagnostic accuracy in the follow-up of brain gliomas, identifying the progression of disease before it becomes evident in the standard MRI; also to evaluate which of the two techniques has the best diagnostic accuracy. Methods Eighty-three patients with cerebral glioma (50 high-grade gliomas (HGGs), 33 low-grade gliomas (LGGs)) were retrospectively enrolled...
June 2017: Neuroradiology Journal
https://www.readbyqxmd.com/read/28616928/-clinical-study-of-rs-epi-dwi-to-improve-imaging-quality-and-assessment-on-intracranial-mass-lesions
#4
Kai Zhang, Chun-Chao Xia, Qiang Yue, Tao Guo, Wan-Lin Peng, Yu-Ming Li, Lei Li, Fei Zhao, Jin Pu, Qi Leng, Zhen-Lin Li
OBJECTIVES: To explore the clinical value of readout-segmented echo planar imaging (Rs-EPI) sequence in the assessment of intracranial mass lesions compared to the standard single-shot EPI (Ss-EPI) sequence. METHODS: We included 21 patients with intracranial mass lesions who underwent both Ss-EPI diffusion weighted imaging (DWI) and Rs-EPI DWI at 3.0T MR scanner with a twenty-channel head-neck coil. The quality of images was assessed by two experienced radiologists independently...
May 2017: Sichuan da Xue Xue Bao. Yi Xue Ban, Journal of Sichuan University. Medical Science Edition
https://www.readbyqxmd.com/read/28608411/interleaved-epi-diffusion-imaging-using-spirit-based-reconstruction-with-virtual-coil-compression
#5
Zijing Dong, Fuyixue Wang, Xiaodong Ma, Zhe Zhang, Erpeng Dai, Chun Yuan, Hua Guo
PURPOSE: To develop a novel diffusion imaging reconstruction framework based on iterative self-consistent parallel imaging reconstruction (SPIRiT) for multishot interleaved echo planar imaging (iEPI), with computation acceleration by virtual coil compression. METHODS: As a general approach for autocalibrating parallel imaging, SPIRiT improves the performance of traditional generalized autocalibrating partially parallel acquisitions (GRAPPA) methods in that the formulation with self-consistency is better conditioned, suggesting SPIRiT to be a better candidate in k-space-based reconstruction...
June 12, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28602499/susceptibility-weighted-angiography-and-diffusion-weighted-imaging-in-posterior-reversible-encephalopathy-syndrome-is-there-an-association-between-hemorrhage-cytotoxic-edema-blood-pressure-and-imaging-severity
#6
Shivaprakash Basavanthaiah Hiremath, Amol Anantrao Gautam, Shilpa Anil, Reji Thomas, Geena Benjamin
PURPOSE: To assess the significance of association and possible correlation between hemorrhage, cytotoxic edema, blood pressure and imaging severity in posterior reversible encephalopathy syndrome (PRES). MATERIALS AND METHODS: This retrospective study included the medical and imaging records of 35 consecutive patients with PRES. The clinical data analysis included the highest recorded blood pressure (BP) on the day of the ictus, MRI including spin-echo echo planar diffusion-weighted imaging (DWI), susceptibility weighted angiography (SWAN) and conventional sequences...
June 8, 2017: Journal of Neuroradiology. Journal de Neuroradiologie
https://www.readbyqxmd.com/read/28596547/echo-planar-j-resolved-spectroscopic-imaging-using-dual-read-outs-implementation-and-quantitation-of-human-brain-metabolites
#7
Manoj K Sarma, Rajakumar Nagarajan, Zohaib Iqbal, Paul M Macey, M Albert Thomas
Attempts have been made to reduce the total scan time in multi-dimensional J-resolved spectroscopic imaging (JRESI) using an echo-planar (EP) readout gradient, but acquisition duration remains a limitation for routine clinical use in the brain. We present here a significant acceleration achieved with a 4D EP-JRESI sequence that collects dual phase encoded lines within a single repetition time (TR) using two bipolar read-out trains. The performance and reliability of this novel 4D sequence, called Multi-Echo based Echo-Planar J-resolved Spectroscopic Imaging (ME-EP-JRESI), was evaluated in 10 healthy controls and a brain phantom using a 3 T MRI/MRS scanner...
June 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28590562/robust-epi-nyquist-ghost-removal-by-incorporating-phase-error-correction-with-sensitivity-encoding-pec-sense
#8
Victor B Xie, Mengye Lyu, Yilong Liu, Yanqiu Feng, Ed X Wu
PURPOSE: The existing approach of Nyquist ghost correction by parallel imaging in echo planar imaging (EPI) can suffer from image noise amplification. We propose a method that estimates a phase error map from multi-channel data itself and incorporates it into the sensitivity encoding (SENSE) reconstruction for Nyquist ghost correction without compromising the image SNR. METHODS: This method first reconstructs two ghost-free images from positive and negative echoes using SENSE, respectively, from which the phase error map is computed...
June 7, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28585229/tomoelastography-of-the-prostate-using-multifrequency-mr-elastography-and-externally-placed-pressurized-air-drivers
#9
Florian Dittmann, Rolf Reiter, Jing Guo, Matthias Haas, Patrick Asbach, Thomas Fischer, Jürgen Braun, Ingolf Sack
PURPOSE: To demonstrate the feasibility of in vivo multifrequency magnetic resonance elastography (MRE) of the prostate using externally placed drivers. METHODS: Three pressurized-air drivers were used to excite shear waves within the prostate at vibration frequencies of 60, 70, and 80 Hz. Full 3D wave fields were acquired by multislice spin-echo echo-planar imaging in conjunction with tomoelastography wave speed recovery for generating full field-of-view stiffness maps...
June 6, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28583626/does-apparent-diffusion-coefficient-predict-the-degree-of-liver-regeneration-of-donor-and-recipient-after-living-donor-liver-transplantation
#10
Koichiro Morita, Akihiro Nishie, Yoshiki Asayama, Kousei Ishigami, Yasuhiro Ushijima, Yukihisa Takayama, Daisuke Okamoto, Nobuhiro Fujita, Toru Ikegami, Tomoharu Yoshizumi, Ken Shirabe, Hiroshi Honda
OBJECTIVE: To elucidate the relationship between the ADCs of the liver graft and the remnant liver and the degree of liver regeneration in LDLT. MATERIALS AND METHODS: 15 recipients and 15 corresponding donors underwent magnetic resonance imaging and computed tomography 1-2 weeks after living donor liver transplantation (LDLT). For diffusion-weighted imaging (DWI), a single-shot echo-planar sequence with b-factors of 0, 500, and 1000s/mm(2) was scanned. ADCs of the liver parenchyma were calculated at b factors of 0 and 500 and 1000 (ADC 0-500-1000) or 0 and 500 (ADC 0-500) or 500 and 1000 (ADC 500-1000)...
May 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28583625/residual-tumour-detection-in-post-treatment-granulation-tissue-by-using-advanced-diffusion-models-in-head-and-neck-squamous-cell-carcinoma-patients
#11
Noriyuki Fujima, Daisuke Yoshida, Tomohiro Sakashita, Akihiro Homma, Kohsuke Kudo, Hiroki Shirato
PURPOSE: To evaluate the detectability of the residual tumour in post-treatment granulation tissue using parameters obtained with an advanced diffusion model in patients with head and neck squamous cell carcinoma (HNSCC) treated by chemoradiation therapy. MATERIALS AND METHODS: We retrospectively evaluated 23 patients with HNSCC after the full course of chemoradiation therapy. The diffusion-weighted image (DWI) acquisition used single-shot spin-echo echo-planar imaging with 11 b-values (0-1000)...
May 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28580597/false-fmri-activation-after-motion-correction
#12
Renat Yakupov, Juan Lei, Michael Hoffmann, Oliver Speck
Motion correction of echo-planar imaging (EPI) data used in functional MRI (fMRI) is an essential preprocessing step performed prior to statistical analysis. At ultra-high resolution fMRI, current requirements regarding translational and rotational motion may no longer be acceptable. This prompts the need for a systematic investigation of the effects of motion correction procedures with in vivo fMRI data. Here we systematically evaluated the effect of retrospective motion correction with freely available fMRI analysis software packages (FSL, AFNI, and SPM) on activation maps using fMRI data acquired with prospective motion detection, to identify and quantify confounding effects of retrospective motion correction, and to evaluate its dependence on spatial resolution and motion correction algorithms...
June 5, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28577332/hippocampal-fractional-amplitude-of-low-frequency-fluctuation-and-functional-connectivity-changes-in-premenstrual-syndrome
#13
Gaoxiong Duan, Huimei Liu, Yong Pang, Peng Liu, Yanfei Liu, Geliang Wang, Hai Liao, Lijun Tang, Wenfu Chen, Xiaping Mo, Danhong Wen, Hua Lin, Demao Deng
PURPOSE: To investigate differences in hippocampal activity between premenstrual syndrome (PMS) patients and healthy controls, to elucidate the neural mechanisms of PMS. MATERIALS AND METHODS: Twenty female patients with PMS (PMS group) and 21 healthy controls (HC group) underwent a single-shot gradient-recalled echo planar imaging (EPI) sequence scan during the luteal phase in 3.0 Tesla MRI. Spontaneous neural activity in hippocampus (HIPP) was measured by fractional amplitude of low-frequency fluctuation (fALFF)...
June 3, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28558457/-diagnostic-value-of-enhanced-ct-mri-for-thyroid-cartilage-invasion-by-malignant-tumor
#14
H Y Li, X H Chen
Objective: To evaluate the values of enhanced CT and MRI for the diagnosis of thyroid cartilage invasion by laryngeal and hypopharyngeal cancer. Methods: One hundred and ninety-seven patients with primary laryngeal or hypopharyngeal cancer treated with surgery between January 2013 and December 2014 were included in this study. All patients underwent enhanced CT and MRI before surgery. With MRI using the techniques of fast recovery fast spin echo (FRFSE), spin echo echo planar imaging (SE-EPI) and diffusion weighted imaging (DWI), thyroid cartilage invasion was evaluated and the results of postoperative histopathological examination was used as a gold standard for the determination of thyroid cartilage invasion...
May 7, 2017: Zhonghua Er Bi Yan Hou Tou Jing Wai Ke za Zhi, Chinese Journal of Otorhinolaryngology Head and Neck Surgery
https://www.readbyqxmd.com/read/28553198/a-resilient-non-neuronal-source-of-the-spatiotemporal-lag-structure-detected-by-bold-signal-based-blood-flow-tracking
#15
Toshihiko Aso, Guanhua Jiang, Shin-Ichi Urayama, Hidenao Fukuyama
Recent evidence has suggested that blood oxygenation level-dependent (BOLD) signals convey information about brain circulation via low frequency oscillation of systemic origin (sLFO) that travels through the vascular structure ("lag mapping"). Prompted by its promising application in both physiology and pathology, we examined this signal component using multiple approaches. A total of 30 healthy volunteers were recruited to perform two reproducibility experiments at 3 Tesla using multiband echo planar imaging...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28552957/safety-and-eeg-data-quality-of-concurrent-high-density-eeg-and-high-speed-fmri-at-3-tesla
#16
Mette Thrane Foged, Ulrich Lindberg, Kishore Vakamudi, Henrik B W Larsson, Lars H Pinborg, Troels W Kjær, Martin Fabricius, Claus Svarer, Brice Ozenne, Carsten Thomsen, Sándor Beniczky, Olaf B Paulson, Stefan Posse
PURPOSE: Concurrent EEG and fMRI is increasingly used to characterize the spatial-temporal dynamics of brain activity. However, most studies to date have been limited to conventional echo-planar imaging (EPI). There is considerable interest in integrating recently developed high-speed fMRI methods with high-density EEG to increase temporal resolution and sensitivity for task-based and resting state fMRI, and for detecting interictal spikes in epilepsy. In the present study using concurrent high-density EEG and recently developed high-speed fMRI methods, we investigate safety of radiofrequency (RF) related heating, the effect of EEG on cortical signal-to-noise ratio (SNR) in fMRI, and assess EEG data quality...
2017: PloS One
https://www.readbyqxmd.com/read/28547846/multiline-balanced-ssfp-for-rapid-functional-imaging-at-ultrahigh-field
#17
Philipp Ehses, Klaus Scheffler
PURPOSE: The goal of this study is to develop and evaluate a multiline balanced steady-state free-precession (bSSFP) sequence for passband functional MRI at ultrahigh field. METHODS: Passband bSSFP functional MRI experiments using a visual task were performed on a 9.4 T system with echo trains ranging from one up to seven echoes. We analyze the acquisition efficiency, temporal and thermal signal-to-noise ratio, as well as the observed blood oxygen-level-dependent (BOLD) signal changes...
May 25, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28543364/diffusion-weighted-mri-with-minimal-distortion-in-head-and-neck-radiotherapy-using-a-turbo-spin-echo-acquisition-method
#18
Tim Schakel, Johannes M Hoogduin, Chris H J Terhaard, Marielle E P Philippens
PURPOSE: Diffusion weighted (DW) MRI, showing high contrast between tumor and background tissue, is a promising technique in radiotherapy for tumor delineation. However, its use for head-and-neck patients is hampered by poor geometric accuracy in conventional echo planar imaging (EPI) DW-MRI. An alternative turbo spin echo sequence, DW-SPLICE, is implemented and demonstrated in patients. METHODS: The DW-SPLICE sequence was implemented on a 3.0T system and evaluated in 10 patients...
May 23, 2017: Medical Physics
https://www.readbyqxmd.com/read/28539914/functional-connectivity-mapping-in-the-animal-model-principles-and-applications-of-resting-state-fmri
#19
REVIEW
Martin Gorges, Francesco Roselli, Hans-Peter Müller, Albert C Ludolph, Volker Rasche, Jan Kassubek
"Resting-state" fMRI has substantially contributed to the understanding of human and non-human functional brain organization by the analysis of correlated patterns in spontaneous activity within dedicated brain systems. Spontaneous neural activity is indirectly measured from the blood oxygenation level-dependent signal as acquired by echo planar imaging, when subjects quietly "resting" in the scanner. Animal models including disease or knockout models allow a broad spectrum of experimental manipulations not applicable in humans...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28526430/combination-of-integrated-dynamic-shimming-and-readout-segmented-echo-planar-imaging-for-diffusion-weighted-mri-of-the-head-and-neck-region-at-3tesla
#20
Sven S Walter, Wei Liu, Alto Stemmer, Petros Martirosian, Konstantin Nikolaou, Mike Notohamiprodjo, Sergios Gatidis
PURPOSE: To evaluate the performance of combined integrated slice-by-slice shimming and readout-segmented EPI (irsEPI) for diffusion-weighted MR imaging (DWI) of the neck at 3Tesla. METHODS: This study was approved by the local ethics committee. An anthropometric phantom of the head/neck region incorporating compartments with different diffusivities was constructed. In vivo measurements were performed in 10 healthy volunteers. DWI of the phantom and volunteers was performed on a 3Tesla MR scanner using single shot EPI (sEPI), a prototype single shot EPI with integrated slice-by-slice shimming (iEPI), readout segmented EPI (rsEPI) and a prototype readout segmented EPI with integrated shimming irsEPI...
May 17, 2017: Magnetic Resonance Imaging
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