Temperature measurement of intracranial cerebrospinal fluid using second-order motion compensation diffusion tensor imaging

Author(s):  
Shuhei Shibukawa ◽  
Tetsu Niwa ◽  
Tosiaki Miyati ◽  
Tetsuo Ogino ◽  
Daisuke Yoshimaru ◽  
...  

Abstract AbstractTo reduce the determination errors of CSF pulsation in diffusion-weighted image (DWI) thermometry, we investigated whether applying second-order motion compensation diffusion tensor imaging (2nd-MC DTI) and fractional anisotropy (FA) processing improves the measurement of intracranial cerebrospinal fluid (CSF) temperature. In a phantom study, we investigated the relationship between temperature and FA in artificial CSF (ACSF) to determine the threshold for FA processing. The temperatures of ACSF were compared with those of water. In a human study, 18 healthy volunteers were scanned using conventional DTI (c-DTI) and 2nd-MC DTI on a 3.0T magnetic resonance imaging (MRI) system. A temperature map was created using diffusion coefficients from each DWI with/without FA processing. The temperatures of intracranial CSF were compared between each DTI image using Welch’s analysis of variance and Games–Howell’s multiple comparisons. In the phantom study, FA did not exceed 0.1 at any temperature. Consequently, pixels exceeding the threshold of 0.1 were removed from the temperature map. Intracranial CSF temperatures significantly differed between the four methods (p < 0.0001). The lowest temperature was 2nd-MC DTI with FA processing (mean, 35.62℃), followed in order by c-DTI with FA processing (mean, 36.16℃), 2nd-MC DTI (mean, 37.08℃), and c-DTI (mean, 39.08℃; p < 0.01 for each). Because the temperature of ACSF was estimated to be lower than that of water, the temperature of 2nd-DTI with FA processing was considered reasonable. The method of 2nd-MC DTI with FA processing enabled determining intracranial CSF temperature with a reduction in CSF pulsation.

2014 ◽  
Vol 60 (5) ◽  
pp. 215-222 ◽  
Author(s):  
Cristina Goga ◽  
Zeynep Firat ◽  
Klara Brinzaniuc ◽  
Is Florian

Abstract Objective: The ultimate anatomy of the Meyer’s loop continues to elude us. Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) may be able to demonstrate, in vivo, the anatomy of the complex network of white matter fibers surrounding the Meyer’s loop and the optic radiations. This study aims at exploring the anatomy of the Meyer’s loop by using DTI and fiber tractography. Methods: Ten healthy subjects underwent magnetic resonance imaging (MRI) with DTI at 3 T. Using a region-of-interest (ROI) based diffusion tensor imaging and fiber tracking software (Release 2.6, Achieva, Philips), sequential ROI were placed to reconstruct visual fibers and neighboring projection fibers involved in the formation of Meyer’s loop. The 3-dimensional (3D) reconstructed fibers were visualized by superimposition on 3-planar MRI brain images to enhance their precise anatomical localization and relationship with other anatomical structures. Results: Several projection fiber including the optic radiation, occipitopontine/parietopontine fibers and posterior thalamic peduncle participated in the formation of Meyer’s loop. Two patterns of angulation of the Meyer’s loop were found. Conclusions: DTI with DTT provides a complimentary, in vivo, method to study the details of the anatomy of the Meyer’s loop.


2021 ◽  
pp. 028418512110582
Author(s):  
Takumi Yokohama ◽  
Motoyuki Iwasaki ◽  
Daisuke Oura ◽  
Sho Furuya ◽  
Yoshimasa Niiya

Background Recent studies have indicated that injuries such as muscle tears modify the microstructural integrity of muscle, leading to substantial alterations in measured diffusion parameters. Therefore, the fractional anisotropy (FA) value decreases. However, we hypothesized that soft tissue, such as muscle tissue, undergoes reversible changes under conditions of compression without fiber injury. Purpose To evaluate the FA change due to compression in muscle tissue without fiber injury. Material and Methods Diffusion tensor imaging (DTI) was performed on both feet of 10 healthy volunteers (mean age = 35.0 ± 10.39 years; age range = 23–52 years) using a 3.0-T magnetic resonance imaging (MRI) scanner with an eight-channel phased array knee coil. An MRI-compatible sphygmomanometer was applied to the individuals’ lower legs and individuals were placed in a compressed state. Then, rest intervals of 5 min were set in re-rest state after compression. The FA value, apparent diffusion coefficient (ADC), and eigenvalues (λ1, λ2, λ3) of the gastrocnemius and soleus muscle were measured at each state. Results The mean FA values increased in all muscles in a compressed state, while the mean λ3 decreased. In all muscles, significant differences were found between the rest and compressed states in terms of mean FA and λ3 ( P < 0.0001). Conclusion We confirmed the reversibility of the DTI metrics, which suggests that there was no muscle injury during this study. In cases of compression without fiber injury, the FA value increases, because fibers are strongly aligned in the longitudinal direction.


2019 ◽  
Vol 33 (1) ◽  
pp. 66-74
Author(s):  
Irene Grazzini ◽  
Francesco Redi ◽  
Karima Sammartano ◽  
Gian Luca Cuneo

Purpose Diffusion tensor imaging is a magnetic resonance technique that provides information about the orientation and anisotropy of the white matter tracts. The aim of this study was to analyse diffusion tensor imaging quantitative parameters in idiopathic normal pressure hydrocephalus patients, in order to determine whether this method could correlate to clinical scores and cerebrospinal fluid flowmetry data. Methods and materials Fifteen consecutive patients with idiopathic normal pressure hydrocephalus and 15 age-matched controls underwent cerebrospinal fluid flowmetry and diffusion tensor imaging using a 1.5 Tesla system. Fractional anisotropy, mean diffusivity, axial diffusivity and radial diffusivity values were calculated using region of interest atlas-based tract-mapping in nine cerebral areas and compared among the two groups. In addition, for idiopathic normal pressure hydrocephalus patients, diffusion tensor imaging parameters were correlated to clinical scores (mini mental state examination and frontal assessment battery) and cerebrospinal fluid flowmetry data. Results Mean fractional anisotropy was significantly lower for the idiopathic normal pressure hydrocephalus group than for the control group in the forceps minor and motor cortex; the idiopathic normal pressure hydrocephalus group had significantly higher mean axial diffusivity for the genu of the corpus callosum and forceps minor. We did not find significant correlation between diffusion tensor imaging parameters and cerebrospinal fluid flowmetry and mini mental state examination, while we observed a correlation between forceps minor fractional anisotropy and frontal assessment battery; no correlation between flowmetry and clinical scores was found. Conclusion Our findings suggest that diffusion tensor imaging provides a non-invasive biomarker of white matter changes in idiopathic normal pressure hydrocephalus patients. Forceps minor is the best site to analyse. As diffusion tensor imaging offers a better correlation to clinical status than cerebrospinal fluid flowmetry, it should be included in the routine idiopathic normal pressure hydrocephalus protocol.


Author(s):  
Evanthia E. Tripoliti ◽  
Dimitrios I. Fotiadis ◽  
Konstantia Veliou

Diffusion Tensor Imaging (DTI) is a magnetic resonance imaging (MRI) modality which can significantly improve our understanding of the brain structures and neural connectivity. DTI measures are thought to be representative of brain tissue microstructure and are particularly useful for examining organized brain regions, such as white matter tract areas. DTI measures the water diffusion tensor using diffusion weighted pulse sequences which are sensitive to microscopic random water motion. The resulting diffusion weighted images (DWI) display and allow quantification of how water diffuses along axes or diffusion encoding directions. This can help to measure and quantify the tissue’s orientation and structure, making it an ideal tool for examining cerebral white matter and neural fiber tracts. In this chapter the authors discuss the theoretical aspects of DTI, the information that can be extracted from DTI data, and the use of the extracted information for the reconstruction of fiber tracts and the diagnosis of a disease. In addition, a review of known fiber tracking algorithms is presented.


2019 ◽  
Vol 5 (1) ◽  
pp. 59-64
Author(s):  
Jiefei Li ◽  
Le He ◽  
Yuqi Zhang

Objective: To explore the usefulness of multishot diffusion tensor imaging (DTI) for evaluating the neurological function of patients with spinal cord tumors Methods: Routine magnetic resonance imaging and multishot DTI were performed in five patients with spinal cord tumors. The values of fractional anisotropy (FA) and radial diffusivity (RD) were analyzed. Results: Multishot DTI of spinal cord tumors allowed for defining the margins of tumors and determining the relationship of tumors with the adjacent white matter structures of the spinal cord. Multishot DTI demonstrated significantly increased RD and decreased FA of spinal cord tumors compared with those of the normal spinal cord. Conclusions: Multishot DTI is a potentially useful modality for differentiating resectable tumors from nonresectable ones based on preoperative imaging alone as well as for differentiating intramedullary tumors from extramedullary ones. Further prospective studies are warranted to confirm these results.


2020 ◽  
pp. 197140092097515
Author(s):  
Irene Grazzini ◽  
Duccio Venezia ◽  
Gian Luca Cuneo

Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome that comprises a triad of gait disturbance, dementia and urinary incontinence, associated with ventriculomegaly in the absence of elevated intraventricular cerebrospinal fluid (CSF) pressure. It is important to identify patients with iNPH because some of its clinical features may be reversed by the insertion of a CSF shunt. The diagnosis is based on clinical history, physical examination and brain imaging, especially magnetic resonance imaging (MRI). Recently, some papers have investigated the role of diffusion tensor imaging (DTI) in evaluating white matter alterations in patients with iNPH. DTI analysis in specific anatomical regions seems to be a promising MR biomarker of iNPH and could also be used in the differential diagnosis from other dementias. However, there is a substantial lack of structured reviews on this topic. Thus, we performed a literature search and analyzed the most recent and pivotal articles that investigated the role of DTI in iNPH in order to provide an up-to-date overview of the application of DTI in this setting. We reviewed studies published between January 2000 and June 2020. Thirty-eight studies and four reviews were included. Despite heterogeneity in analysis approaches, the majority of studies reported significant correlations between DTI and clinical symptoms in iNPH patients, as well as different DTI patterns in patients with iNPH compared to those with Alzheimer or Parkinson diseases. It remains to be determined whether DTI could predict the success after CSF shunting.


NeuroImage ◽  
2008 ◽  
Vol 42 (4) ◽  
pp. 1654-1668 ◽  
Author(s):  
Anders M. Fjell ◽  
Lars T. Westlye ◽  
Doug N. Greve ◽  
Bruce Fischl ◽  
Thomas Benner ◽  
...  

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