共查询到20条相似文献,搜索用时 31 毫秒
1.
Thomas A. Hope John-Peder Escobar Kvitting Michael D. Hope D. Craig Miller Michael Markl Robert J. Herfkens 《Magnetic resonance imaging》2013
Background
Over the past two decades elective valve-sparing aortic root replacement (V-SARR) has become more common in the treatment of patients with aortic root and ascending aortic aneurysms. Currently there are little data available to predict complications in the post-operative population. The study goal was to determine if altered flow patterns in the thoracic aorta, as measured by MRI, are associated with complications after V-SARR.Methods
Time-resolved three-dimensional phase-contrast MRI (4D flow) was used to image 12 patients with Marfan syndrome after V-SARR. The patients were followed up for an average of 5.8 years after imaging and 8.2 years after surgery. Additionally 5 volunteers were imaged for comparison. Flow profiles were visualized during peak systole using streamlines. Wall shear stress estimates and normalized flow displacement were evaluated at multiple planes in the thoracic aorta.Results
During the follow-up period, a single patient developed a Stanford Type B aortic dissection. At initial imaging, prior to the development of the dissection, the patient had altered flow patterns, wall shear stress estimates, and increased normalized flow displacement in the thoracic aorta in comparison to the remaining V-SARR patients and volunteers.Conclusions
This is the first follow-up study of patients after 4D flow imaging. An aortic dissection developed in one patient with altered flow patterns and hemodynamic stresses in the thoracic aorta. These results suggest that flow and altered hemodynamics may play a role in the development of post-operative intramural hematomas and dissections. 相似文献2.
Purpose
Using simultaneous multiple cross-sectional imaging, we imaged four cross sections, including the mandibular midline and the right and left temporomandibular joints, to observe one movement of mouth opening and closing and analyze the movement of the mandible and temporomandibular joints.Materials and Methods
Four cross sections, including the midsagittal section of the mandible, the sagittal sections of the right and left temporomandibular joints and the horizontal section containing the heads of right and left temporomandibular joints, were imaged simultaneously. The imaging was conducted in 10 male and female volunteers.Results
In all volunteers, the relationship of the mandibular movement on the median line with the right and left temporomandibular joints was observed. Images of the volunteers with trismus indicated the condition in which the right and left temporomandibular joints did not move in keeping with each other but moved independently from each other.Conclusion
Complex movement of the temporomandibular joint was first evaluated by simultaneous multiple cross-sectional MRI for the movement of mandible and temporomandibular joints. 相似文献3.
Jing Liu Petter Dyverfeldt Gabriel Acevedo-Bolton Michael Hope David Saloner 《Magnetic resonance imaging》2014
Purpose
To investigate an effective time-resolved variable-density random undersampling scheme combined with an efficient parallel image reconstruction method for highly accelerated aortic 4D flow MR imaging with high reconstruction accuracy.Materials and Methods
Variable-density Poisson-disk sampling (vPDS) was applied in both the phase-slice encoding plane and the temporal domain to accelerate the time-resolved 3D Cartesian acquisition of flow imaging. In order to generate an improved initial solution for the iterative self-consistent parallel imaging method (SPIRiT), a sample-selective view sharing reconstruction for time-resolved random undersampling (STIRRUP) was introduced. The performance of different undersampling and image reconstruction schemes were evaluated by retrospectively applying those to fully sampled data sets obtained from three healthy subjects and a flow phantom.Results
Undersampling pattern based on the combination of time-resolved vPDS, the temporal sharing scheme STIRRUP, and parallel imaging SPIRiT, were able to achieve 6-fold accelerated 4D flow MRI with high accuracy using a small number of coils (N = 5). The normalized root mean square error between aorta flow waveforms obtained with the acceleration method and the fully sampled data in three healthy subjects was 0.04 ± 0.02, and the difference in peak-systolic mean velocity was − 0.29 ± 2.56 cm/s.Conclusion
Qualitative and quantitative evaluation of our preliminary results demonstrate that time-resolved variable-density random sampling is efficient for highly accelerating 4D flow imaging while maintaining image reconstruction accuracy. 相似文献4.
Chuen Y. Poon Julie M. Edwards C. John Evans Ashley D. Harris Beverly Tsai-Goodman Charlotte E. Bolton John R. Cockcroft Richard G. Wise Sailesh Kotecha 《Magnetic resonance imaging》2013
Purpose
To assess the feasibility of measuring pulmonary artery (PA) pulse wave velocity (PWV) in children breathing ambient air and 12% oxygen.Methods
Velocity-encoded phase-contrast MR images of the PA were acquired in 15 children, aged 9–12 years, without evidence of cardiac or pulmonary diseases. PWV was derived as the ratio of flow to area changes during early systole. Each child was scanned twice, in air and after at least 20 minutes into inspiratory hypoxic challenge. Intra-observer and inter-observer variability and repeatability were also compared.Results
PA PWV, which was successfully measured in all subjects, increased from 1.31 ± 0.32 m/s in air to 1.61 ± 0.58 m/s under hypoxic challenge (p = 0.03). Intra- and inter-observer coefficients of variations were 9.0% and 15.6% respectively. Good correlation within and between observers of r = 0.92 and r = 0.72 respectively was noted for PA PWV measurements. Mean (95% limit of agreement) intra- and inter-observer agreement on Bland–Altman analysis were − 0.02 m/s (− 0.41–0.38 m/s) and -0.28 m/s (− 1.06–0.49 m/s).Conclusion
PA PWV measurement in children using velocity-encoded MRI is feasible, reproducible and sufficiently sensitive to detect differences in PA compliance between normoxia and hypoxia. This technique can be used to detect early changes of PA compliance and monitor PAH in children. 相似文献5.
Purpose
The objective of this study was to compare multiple methods for estimation of PWV from 4D flow MRI velocity data and to investigate if 4D flow MRI-based PWV estimation with piecewise linear regression modeling of travel-distance vs. travel time is sufficient to discern age-related regional differences in PWV.Methods
4D flow MRI velocity data were acquired in 8 young and 8 older (age: 23 ± 2 vs. 58 ± 2 years old) normal volunteers. Travel-time and travel-distance were measured throughout the aorta and piecewise linear regression was used to measure global PWV in the descending aorta and regional PWV in three equally sized segments between the top of the aortic arch and the renal arteries. Six different methods for extracting travel-time were compared.Results
Methods for estimation of travel-time that use information about the whole flow waveform systematically overestimate PWV when compared to methods restricted to the upslope-portion of the waveforms (p < 0.05). In terms of regional PWV, a significant interaction was found between age and location (p < 0.05). The age-related differences in regional PWV were greater in the proximal compared to distal descending aorta.Conclusion
Care must be taken as different classes of methods for the estimation of travel-time produce different results. 4D flow MRI-based PWV estimation with piecewise linear regression modeling of travel-distance vs. travel time can discern age-related differences in regional PWV well in line with previously reported data. 相似文献6.
Satoru Morita Kazufumi SuzukiAi Masukawa Shinya KojimaMasami Hirata Eiko Ueno 《Magnetic resonance imaging》2010
Purpose
We aimed to evaluate flow patterns in the superior vena cava (SVC) and azygos vein confluence with cine phase-contrast magnetic resonance imaging with consideration for the role played by the azygos arch valves.Materials and Methods
Two-dimensional cine phase-contrast magnetic resonance images of the SVC and azygos vein confluence were prospectively acquired in 10 healthy volunteers. Flow directions during the cardiac cycle were evaluated quantitatively using sequential flow profile graphs obtained from each orthogonal image and affirmed visually by two radiologists from the oblique sagittal cine images.Results
Although the blood in the SVC and azygos vein confluence had an afferent flow during the systolic phase, a slight temporal efferent flow during the diastolic phase was quantitatively observed in all cases. Flow in the SVC can also be confirmed visually. The average velocity, average maximum afferent velocity during the systolic phase and average maximum efferent velocity during the diastolic phase of the SVC were 8.7±2.4, 19.9±3.7 and −1.0±3.2 cm/s, respectively; for the azygos vein confluence, these values were 2.2±1.5, 7.1±2.6 and −1.5±1.1 cm/s, respectively.Conclusion
We verified that a slight temporal efferent flow exists in the SVC and azygos vein confluence during the diastolic phase, which suggests that the usual role of the azygos arch valves is to prevent this physiological retrograde flow. 相似文献7.
Yusuke Inoue Hirofumi Hata Ai Nakajima Yuji Iwadate Gou Ogasawara Keiji Matsunaga 《Magnetic resonance imaging》2014
Purpose
To optimize the navigator-gating technique for the acquisition of high-quality three-dimensional spoiled gradient-recalled echo (3D SPGR) images of the liver during free breathing.Materials and methods
Ten healthy volunteers underwent 3D SPGR magnetic resonance imaging of the liver using a conventional navigator-gated 3D SPGR (cNAV-3D-SPGR) sequence or an enhanced navigator-gated 3D SPGR (eNAV-3D-SPGR) sequence. No exogenous contrast agent was used. A 20-ms wait period was inserted between the 3D SPGR acquisition component and navigator component of the eNAV-3D-SPGR sequence to allow T1 recovery. Visual evaluation and calculation of the signal-to-noise ratio were performed to compare image quality between the imaging techniques.Result
The eNAV-3D-SPGR sequence provided better noise properties than the cNAV-3D-SPGR sequence visually and quantitatively. Navigator gating with an acceptance window of 2 mm effectively inhibited respiratory motion artifacts. The widening of the window to 6 mm shortened the acquisition time but increased motion artifacts, resulting in degradation of overall image quality. Neither slice tracking nor incorporation of short breath holding successfully compensated for the widening of the window.Conclusion
The eNAV-3D-SPGR sequence with an acceptance window of 2 mm provides high-quality 3D SPGR images of the liver. 相似文献8.
Kersten Peldschus Alexander Schultze Peter Nollau Michael Kaul Udo Schumacher Christoph Wagener Gerhard Adam Harald Ittrich 《Magnetic resonance imaging》2010
Purpose
To detect anti-CEACAM5 targeted superparamagnetic iron oxide (SPIO) particles in vitro on the cell surface by quantitative magnetic resonance (MR) imaging and to compare with flow cytometry.Materials and Methods
The monoclonal mouse antibody T84.1 and an appropriate IgG isotype antibody were conjugated to dextran-coated SPIO particles. HT29 cells expressing carcinoembryonic antigen (CEACAM5) were treated with antibody-conjugated SPIO particles. Purified cell samples were examined on a 3.0-T MR scanner using a multi-echo spin-echo sequence for MR relaxometry. Aliquots of the cell samples were further treated with a fluorescein isothiocyanate (FITC) anti-dextran antibody and an Alexa Fluor 488 anti-mouse antibody for the corresponding flow cytometry.Results
MR relaxometry revealed a dose-dependent binding of T84.1-conjugated SPIO particles with a positive correlation between R2 relaxation rate of cell samples and SPIO particle concentration during incubation (r=0.993, P<.01). Positive correlations were also observed between R2 relaxation rate and flow cytometry (geometric mean) with both fluorescent antibodies (r=0.972 and r=0.953, both P<.01), respectively.Conclusion
The study revealed the feasibility of quantitative MR imaging of targeted SPIO particles on the cell surface comparable to flow cytometry. 相似文献9.
Elisabeth Pittschieler Pavol Szomolanyi Martina Schmid-Schwap Michael Weber Monika Egerbacher Hannes Traxler Siegfried Trattnig 《Magnetic resonance imaging》2014
Objective
To 1) test the feasibility of delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) at 3 T in the temporomandibular joint (TMJ) and 2) to determine the optimal delay for measurements of the TMJ disc after i.v. contrast agent (CA) administration.Design
MRI of the right and left TMJ of six asymptomatic volunteers was performed at 3 T using a dedicated coil. 2D inversion recovery (2D-IR) sequences were performed at 4 time points covering 120 minutes and 3D gradient-echo (3D GRE) dual flip-angle sequences were performed at 14 time points covering 130 minutes after the administration of 0.2 mmol/kg of Gd-diethylenetriamine pentaacetic acid ion (Gd-DTPA)2-, i.e., 0.4 mL of Magnevist™ per kg body weight. Pair-wise tests were used to assess differences between pre-and post-contrast T1 values.Results
2D-IR sequences showed a statistically significant drop (p < 0.001) in T1 values after i.v. CA administration. The T1 drop of 50% was reached 60 minutes after bolus injection in the TMJ disc. The 3D GRE dual flip-angle sequences confirmed these results and show plateau of T1 after 60 minutes.Conclusions
T1(Gd) maps calculated from dGEMRIC data allow in vivo assessment of the fibrocartilage disc of the TMJ. The recommended measurement time for dGEMRIC in the TMJ after i.v. CA administration is from 60 to 120 minutes. 相似文献10.
Chengcheng Zhu Umar Sadat Andrew J. Patterson Zhongzhao Teng Jonathan H. Gillard Martin J. Graves 《Magnetic resonance imaging》2014
Objective
Development of a fast 3D high-resolution magnetic resonance imaging (MRI) protocol for improved carotid artery plaque imaging.Methods
Two patients with carotid atherosclerosis disease underwent 3D high-resolution MRI which included time-of-flight and T1-weighted variable flip angle, fast-spin-echo (FSE) imaging, pre- and post-intravenous gadolinium-based contrast agent administration.Results
Good quality images with intrinsic blood suppression were obtained pre- and post-contrast administration using a 3D FSE sequence. The plaque burden, lipid core volume, hemorrhage volume and fibrous cap thickness were well determined.Conclusions
3D high-resolution MR imaging of carotid plaque using TOF and 3D FSE can achieve high isotropic resolution, large coverage, and excellent image quality within a short acquisition time. 相似文献11.
Keiji Matsunaga Gou Ogasawara Masaru Tsukano Yuji Iwadate Yusuke Inoue 《Magnetic resonance imaging》2013
Purpose
To prospectively compare the navigator-echo triggering technique (navigator technique) and the conventional respiratory triggering technique using bellows (bellows technique) for free-breathing three-dimensional (3D) magnetic resonance cholangiopancreatography (MRCP) under clinical conditions.Materials and methods
Forty patients referred for evaluation of biliary or pancreatic diseases underwent 3D MRCP examination using both navigator and bellows techniques. Two independent radiologists visually evaluated the image quality of 12 segments of the pancreaticobiliary tree in a blinded manner. In addition, the clarity of the lesion was compared between the two techniques in a side-by-side manner.Result
MRCP images were successfully acquired using both techniques in all patients. No significant difference in acquisition time was found between the two techniques. The image quality was significantly better using the navigator technique than using the bellows technique for the following seven segments: the head, body, and tail of the pancreatic duct; right hepatic duct; anterior and posterior segments of the right hepatic duct; and cystic duct. The other segments (common hepatic and bile duct, left hepatic duct, medial and lateral segments of left hepatic duct, gallbladder) showed no significant difference. The clarity of lesion depiction was significantly better using the navigator technique than using the bellows technique.Conclusion
Respiratory-triggered 3D MRCP using the navigator technique was shown to be feasible in routine clinical practice. The navigator technique improved the image quality of free-breathing 3D MRCP compared with the bellows technique. The clarity of lesion visualization was also better using the navigator technique than using the bellows technique. 相似文献12.
Jason A. Pates Mustapha R. Hatab Donald D. McIntire F. Gary Cunningham Diane M. Twickler 《Magnetic resonance imaging》2010
Objective
The purpose of this study is to determine the feasibility of measuring total uterine blood flow in pregnancy using magnetic resonance imaging (MRI) technique.Methods
Uterine blood flow was determined in pregnant women in whom MRI was being carried out to assess a fetal anomaly. A two-dimensional time-of-flight magnetic resonance (MR) angiogram sequence was performed. Scout images and a peripherally gated phase contrast MR sequence were planned to study simultaneous blood flow in the uterine and ovarian arteries.Results
The MR pelvic angiogram sequence was completed in 13 women. The uterine arteries were visualized and their cross-sectional area determined. The complexity of the pelvic blood supply prevented the calculation of blood flow velocity and, thus, total uterine blood flow.Conclusion
The measurement of total uterine blood flow during pregnancy was not possible using our MR technique. The ovarian vessels were not consistently visualized. Doppler ultrasonography remains the best modality by which to estimate total uterine blood flow in pregnancy. 相似文献13.
M. Tamizur Rahman Sean K. Sethi David T. Utriainen J. Joseph Hewett E. Mark Haacke 《Magnetic resonance imaging》2013
Background and Purpose
The use of magnetic resonance imaging (MRI) to assess the vascular nature of diseases such as multiple sclerosis (MS) is a growing field of research. This work reports on the application of MR angiographic (MRA) and venographic (MRV) techniques in assessing the extracranial vasculature in MS patients.Materials and Methods
A standardized MRI protocol containing 2D TOF-MRV and dynamic 3D contrast-enhanced (CE) MRAV was run for 170 MS patients and 40 healthy controls (HC). The cross-sectional area (CSA) of the internal jugular veins (IJVs) was measured at three neck levels in all subjects for both MRV techniques to determine the presence of venous stenoses. All data were analyzed retrospectively.Results
For the values where both methods showed signal, the 3D method showed larger CSA measurement values compared to 2D methods in both IJVs, in both MS and HC subjects which was confirmed with student paired t-tests. Of the 170 MS patients, 93 (55%) in CE-MRAV and 103 (61%) in TOF-MRV showed stenosis in at least one IJV. The corresponding numbers for the 40 HC subjects were 2 (5%) and 4 (10%), respectively. Carotid ectasias with IJV stenosis were seen in 26 cases (15%) with 3D CE-MRAV and were not observable with 2D TOF-MRV. Carotid ectasias were not seen in the HC group. In the 2D TOF-MRV data, banding of the IJVs related to slow flow was seen in 58 (34%) MS cases and in no HC cases. MS patients showed lower average CSAs than the HC subjects.Conclusion
The 3D CE MRAV depicted the vascular anatomy more completely than the 2D TOF-MRV. However, the 3D CE MRAV does not provide any information about the flow characteristics which are indirectly available in the 2D TOF-MRV in those cases where there is slow flow. 相似文献14.
Wafaa Zaaraoui Audrey Rico Bertrand Audoin Françoise Reuter Irina Malikova Elisabeth Soulier Patrick Viout Yann Le Fur Sylviane Confort-Gouny Patrick J. Cozzone Jean Pelletier Jean-Philippe Ranjeva 《Magnetic resonance imaging》2010
Background
Acute symptomatic inflammation is a main feature of multiple sclerosis but pathophysiological processes underlying total or partial recovery are poorly understood.Objective
To characterize in vivo these processes at molecular, structural and functional levels using multimodal MR methods.Methods
A neuroimaging 3-year follow-up (Weeks 0, 3, 11, 29, 59 and 169) was conducted on a 41-year-old woman presenting at baseline with a large acute demyelinating lesion of multiple sclerosis. Conventional magnetic resonance imaging (MRI), magnetization transfer imaging, diffusion-weighted imaging, functional MRI and magnetic resonance spectroscopy were conducted at 1.5 T.Results
Patient presenting with subacute left hemiplegia recovered progressively (expended disability status scale 7 to 5.5). The MR exploration demonstrated structural functional and metabolic impairments at baseline. Despite restoration of the blood brain barrier integrity, high lactate levels persisted for several weeks concomitant with glial activation. Slow and progressive structural and metabolic restorations occurred from baseline to W169 (lesion volume −64%; apparent diffusion coefficient −14.7%, magnetization transfer ratio +14%, choline −51%, lipids −78%, N-acetylaspartate +77%) while functionality of the motor system recovered.Conclusions
Multimodal MRI/MRS evidenced long-term dynamics recovery processes involving tissue repair, glial activation, recovery of neuronal function and functional systems. This may impact on customized rehabilitation strategies generally focused on the first months following the onset of symptoms. 相似文献15.
von Morze C Purcell DD Banerjee S Xu D Mukherjee P Kelley DA Majumdar S Vigneron DB 《Magnetic resonance imaging》2008,26(10):1329-1333
Purpose
Greater spatial resolution in intracranial three-dimensional time-of-flight (TOF) magnetic resonance angiography (MRA) is possible at higher field strengths, due to the increased contrast-to-noise ratio (CNR) from the higher signal-to-noise ratio and the improved background suppression. However, at very high fields, spatial resolution is limited in practice by the acquisition time required for sequential phase encoding. In this study, we applied parallel imaging to 7T TOF MRA studies of normal volunteers and patients with vascular disease, in order to obtain very high resolution (0.12 mm3) images within a reasonable scan time.Materials and Methods
Custom parallel imaging acquisition and reconstruction methods were developed for 7T MRA, based on generalized autocalibrating partially parallel acquisition (GRAPPA). The techniques were compared and applied to studies of seven normal volunteers and three patients with cerebrovascular disease.Results
The technique produced high resolution studies free from discernible reconstruction artifacts in all subjects and provided excellent depiction of vascular pathology in patients.Conclusions
7T TOF MRA with parallel imaging is a valuable noninvasive angiographic technique that can attain very high spatial resolution. 相似文献16.
Ersan Altun Vasco Heredia Ertan Pamuklar Mauricio Zapparoli Richard C. Semelka 《Magnetic resonance imaging》2009,27(9):1198-1207
Purpose
To determine the feasibility of post-gadolinium three-dimensional gradient-echo (3D-GE) sequence for the evaluation of the pulmonary arterial vasculature in patients with suspected pulmonary embolism (PE) and in patients with a variety of other disease processes.Materials and Methods
Twenty-six consecutive patients (18 females, 8 males; mean age±S.D., 46.6±21.1 years) who underwent chest magnetic resonance imaging (MRI) including post-gadolinium 3D-GE sequence for the evaluation of PE (Group A, n=13) and a variety of other disease processes (Group B, n=13) were included in the study. Post-gadolinium 3D-GE MR sequences were retrospectively, independently and blindly evaluated by two reviewers for the image quality of pulmonary arterial vasculature, and findings of PE and other disease processes. Clinical and imaging follow-up data for all patients were obtained. Interobserver agreement was calculated by kappa statistics.Results
All central and lobar pulmonary arteries, 71.4–89.6% of segmental arteries and 46.7–52.7% of subsegmental arterial units in both groups were visualized with sufficient diagnostic image quality on post-gadolinium 3D-GE sequences. PE involving lobar and segmental arteries was diagnosed in two patients in each group. Other disease processes including pneumonia, lung nodules, superior vena cava stenosis, lung metastases, chronic lymphocytic leukemia and aortic aneurysm were detected in 10 of 26 patients. There was good to excellent interobserver agreement (0.73 to 1.00) for all findings.Conclusion
Post-gadolinium 3D-GE sequence may be an alternative technique for the visualization of central, lobar and segmental arteries, and may diagnose PE and other pathologies involving the chest in different patient populations. 相似文献17.
Paolo Manganotti Michele Acler Emanuela Formaggio Mirko Avesani Franco Milanese Andrea Baraldo Silvia Francesca Storti Anna Gasparini Roberto Cerini Roberto Pozzi Mucelli Antonio Fiaschi 《Magnetic resonance imaging》2010
Objective
Whereas several studies have used functional magnetic resonance imaging (fMRI) to investigate motor recovery, whether therapy to decrease post-stroke hypertonus alters central motor patterns remains unclear. In this study, we used continuous electromyography (EMG)-fMRI to investigate possible changes in movement-related brain activation in patients receiving Botulinum toxin (BoNT-A) for hand-muscle hypertonus after chronic stroke.Methods
We studied eight stroke patients all of whom had hemiparesis and associated upper-limb hypertonus. All patients underwent an fMRI-EMG recording and clinical-neurological assessment before BoNT-A and 5 weeks thereafter. The handgrip motor task during imaging was fixed across both patients and controls. The movements were metronome paced, movement amplitude and force were controlled with a plastic orthosis, dynamometer and EMG recording. An age-matched control group was recruited from among healthy volunteers underwent the same fMRI-EMG recording.Results
Before BoNT-A, while patients moved the paretic hand, fMRI detected wide bilateral activation in the sensorymotor areas (SM1), in the supplementary motor area (SMA) and cerebellum. After BoNT-A blood oxygenation level-dependent (BOLD) activation decreased in ipsilateral and contralateral motor areas and became more lateralized. BOLD activation decreased also in ipsilateral cerebellar regions and in the SMA.Conclusion
Changes in peripheral upper-limb hypertonus after BoNT-A were associated to an improvement in active movements and more lateralized and focalized activation of motor areas. The clinical and EMG-fMRI coregistration technique we used to study hand-muscle hypertonus in patients receiving BoNT-A after chronic stroke should be useful in future studies seeking improved strategies for post-stroke neurorehabilitation. 相似文献18.
Background and Purpose
The present study was designed to detect the abnormalities of the cortical thickness in children with ametropic amblyopia by a computer-aided MRI technique.Methods
Nine children with ametropic amblyopia and eight age-matched normal controls underwent MRI brain scanning that was performed on a Siemens Avanto 1.5-T scanner, and standard T1-weighted high-resolution anatomic scans of magnetization-prepared rapid gradient echo (MPRAGE) sequence were obtained. For the cortical thickness analysis, 3D MPRAGE images were processed with FreeSurfer software package (http://www.nmr.mgh.harvard.edu/freesurfer/), and the cortical thicknesses were compared between the patient group and the normal control group.Results
The cortical thicknesses of the lingual and pericalcarine areas in the left hemisphere and of the cuneus, lateraloccipital and lingual areas in the right hemisphere in the amblyopic group were significantly thinner than those of the control group (P<.05).Conclusion
The changes in cortical thickness of several occipital regions in amblyopic patients may be important in the diagnosis and treatment of this disease. 相似文献19.
Tong Zhu Rui Hu Wei Tian Sven Ekholm Giovanni Schifitto Xing Qiu Jianhui Zhong 《Magnetic resonance imaging》2013
Objectives
To develop a novel statistical method for analysis of longitudinal DTI data in individual subjects.Materials and Methods
The proposed SPatial REgression Analysis of Diffusion tensor imaging (SPREAD) method incorporates a spatial regression fitting of DTI data among neighboring voxels and a resampling method among data at different times. Both numerical simulations and real DTI data from healthy volunteers and multiple sclerosis (MS) patients were used in the study to evaluate this method.Results
Statistical inference based on SPREAD was shown to perform well through both group comparisons among simulated DTI data of individuals (especially when the group size is smaller than 5) and longitudinal comparisons of human DTI data within the same individual.Conclusions
When pathological changes of neurodegenerative diseases are heterogeneous in a population, SPREAD provides a unique way to assess abnormality during disease progression at the individual level. Consequently, it has the potential to shed light on how the brain has changed as a result of disease or injury. 相似文献20.
Jia-Sheng Rao Manxiu Ma Can Zhao Ai-Feng Zhang Zhao-Yang Yang Zuxiang Liu Xiao-Guang Li 《Magnetic resonance imaging》2014