Differences in Analysis Methods of the Human Uncinate Fasciculus Using Diffusion Tensor MRI

2013 ◽  
pp. 162-170
Author(s):  
Tetsuo Sato ◽  
Kotaro Minato
Keyword(s):  
Magnetic Resonance Imaging ◽  
Functional Role ◽  
Diffusion Tensor ◽  
Region Of Interest ◽  
Fiber Tracking ◽  
Uncinate Fasciculus ◽  
Temporal Lobes ◽  
Analysis Methods ◽  
Magnetic Resonance Imaging Mri

The human uncinate fasciculus is an important cortico-cortical white matter pathway that directly connects the frontal and temporal lobes, but its exact functional role is not yet known. Using diffusion tensor Magnetic Resonance Imaging (MRI), the uncinate fasciculus can be extracted and its volume calculated. DTI metrics such as fractional anisotropy for the uncinate fasciculus can also be analyzed, but there are currently three different methods for this analysis. DTI reports on the uncinate fasciculus are conducted using region of interest, voxel-based, and fiber tracking deterministic approaches. Due to these differences in analysis methods, prior studies report conflicting levels of uncinate asymmetry measured with diffusion anisotropy. Here, the authors briefly introduce these three different methods for measuring uncinate asymmetry values and compare the results. This result can lead to a better understanding of the role of the uncinate fasciculus in future behavioral and clinical studies.

scholarly journals The role of the uncinate fasciculus in the risk-architecture of bipolar disorders: A meta-analysis

2021 ◽  
Author(s):  
Ellie Xu ◽  
Lynn Nguyen ◽  
Rebecca Hu ◽  
Caitlin Stavish ◽  
Ellen Leibenluft ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Meta Analysis ◽  
Familial Risk ◽  
Region Of Interest ◽  
Bipolar Disorders ◽  
Uncinate Fasciculus ◽  
Increased Risk ◽  
The Right ◽  
Meta Analyses

Background: Bipolar disorder (BD) is a severe mental disorder, characterized by prominent mood swings and emotion regulation (ER) deficits. The uncinate fasciculus (UF), a white matter tract connecting the amygdala and the ventral prefrontal cortex, has been implicated in ER. Aberrancies in UF microstructure may be an endophenotype associated with increased risk for BD. However, findings in individuals with BD and at familial risk for BD (AR) have yielded inconsistent findings. This meta-analysis takes a region-of-interest approach to consolidate the available evidence and elucidate the role of the UF in the risk-architecture of BD. Methods: Using web-based search engines, we identified diffusion tensor imaging studies focusing on the left and right UF and conducted meta-analyses comparing fractional anisotropy (FA) and radial diffusivity (RD) between BD or AR to healthy volunteers (HV). Results: We included 32 studies (BD: n=1186, HV: n=2001; AR: n=289, HV-AR: n=314). Compared to HV, individuals with BD showed lower FA in the right (p<.0001) and left UF (p=.010), and higher RD in the right UF (p=.009). We found no significant differences between AR and HV. In the right but not the left UF, AR individuals showed higher FA than BD (p=.043). Conclusion: Comparable UF microstructure between AR and HV and higher FA in the right UF in AR compared to BD suggest that aberrancies in UF microstructure is not an endophenotype for BD. Longitudinal studies are needed to determine when UF abnormalities emerge in the context of BD.

scholarly journals Meyer’s Loop Anatomy Demonstrated Using Diffusion Tensor MR Imaging and Fiber Tractography at 3T

2014 ◽  
Vol 60 (5) ◽  
pp. 215-222 ◽  
Author(s):  
Cristina Goga ◽  
Zeynep Firat ◽  
Klara Brinzaniuc ◽  
Is Florian
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Region Of Interest ◽  
Fiber Tractography ◽  
Brain Images ◽  
3 Dimensional ◽  
Software Release ◽  
Magnetic Resonance Imaging Mri ◽  
Meyer’S Loop

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.

Diffusion tensor tractography of the temporal stem on the inferior limiting sulcus

2008 ◽  
Vol 108 (4) ◽  
pp. 775-781 ◽  
Author(s):  
Feng Wang ◽  
Tao Sun ◽  
Xing-Gang Li ◽  
Na-Jia Liu
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Anterior Commissure ◽  
Region Of Interest ◽  
Diffusion Tensor Tractography ◽  
Optic Radiation ◽  
Uncinate Fasciculus ◽  
White Matter Tracts ◽  
Temporal Horn ◽  
Temporal Stem

Object The aim of this study was to use diffusion tensor tractography (DTT) to define the 3D relationships of the uncinate fasciculus, anterior commissure, inferior occipitofrontal fasciculus, inferior thalamic peduncle, and optic radiation and to determine the positioning landmarks of these white matter tracts. Methods The anatomy was studied in 10 adult human brain specimens. Brain DTT was performed in 10 healthy volunteers. Diffusion tensor tractography images of the white matter tracts in the temporal stem were obtained using the simple single region of interest (ROI) and multi-ROIs based on the anatomical knowledge. Results The posteroinferior insular point is the anterior extremity of intersection of the Heschl gyrus and the inferior limiting sulcus. On the inferior limiting sulcus, this point is the posterior limit of the optic radiation, and the temporal stem begins at the limen insulae and ends at the posteroinferior insular point. The distance from the limen insulae to the tip of the temporal horn is just one third the length of the temporal stem. The uncinate fasciculus comprises the core of the anterior temporal stem, behind which the anterior commissure and the inferior thalamic peduncle are located, and they occupy the anterior third of the temporal stem. The inferior occipitofrontal fasciculus passes through the entire temporal stem. The most anterior extent of the Meyer loop is located between the anterior tip of the temporal horn and the limen insulae. Most of the optic radiation crosses the postmedian two thirds of the temporal stem. Conclusions On the inferior limiting sulcus, the posteroinferior insular point is a reliable landmark of the posterior limit of the optic radiations. The limen insulae, anterior tip of the temporal horn, and posteroinferior insular point may be used to localize the white matter fibers of the temporal stem in analyzing magnetic resonance imaging or during surgery.

scholarly journals Magnetic resonance imaging and pathological features of a mixed glioma in a dog: case report

2018 ◽  
Vol 70 (5) ◽  
pp. 1383-1387 ◽  
Author(s):  
T.M. Granato ◽  
L.P. Mesquita ◽  
R.C. Costa ◽  
J.P. Andrade Neto ◽  
P.C. Maiorka
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Pathological Features ◽  
Resonance Imaging ◽  
Mri Findings ◽  
Neoplastic Cells ◽  
Temporal Lobes ◽  
Mixed Glioma ◽  
Perilesional Edema ◽  
Magnetic Resonance Imaging Mri

ABSTRACT The aim of this report was to describe the magnetic resonance imaging (MRI) and pathological features of a canine mixed glioma. A 12-year-old boxer male dog was presented for necropsy along with data from an MRI evaluation conducted ante-mortem. The images were examined and showed a poorly demarcated prosencephalic lesion, hyperintense on T2W images, hypointense on T1W images and heterogeneously hyperintense on T2W FLAIR images. There was mild nonuniform contrast enhancement, apparent midline shift, moderate perilesional edema and marked distortion of the adjacent lateral ventricle. The brain was evaluated macroscopically, microscopically and immunohistochemically. Grossly, there was a poorly demarcated soft mass, with areas of hemorrhage, within the left parietal and temporal lobes. Histologically, there was a densely cellular mass composed of two geographically distinct populations of neoplastic cells. The first population was composed of small and round cells organized in a honeycomb pattern. The second population constituted of intermingled streams and bundles of neoplastic cells that were strongly immunolabeled for glial fibrillary acidic protein (GFAP). The diagnosis of a mixed glioma was based on MRI findings, and mainly on histological and immunohistochemical findings.

Magnetic Resonance Imaging in Gynecological Oncology

2009 ◽  
Vol 19 (2) ◽  
pp. 186-193 ◽  
Author(s):  
Vanessa N. Harry ◽  
Heather Deans ◽  
Emma Ramage ◽  
David E. Parkin ◽  
Fiona J. Gilbert
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Early Assessment ◽  
Contrast Enhanced ◽  
Crucial Information ◽  
Magnetic Resonance Imaging Mri ◽  
Indispensable Tool ◽  
Improving Patient Care

Magnetic resonance imaging (MRI) has become an indispensable tool in the assessment of malignant disease. With increasingly sophisticated systems and technical advancements, MRI has continued to expand its role in providing crucial information regarding cancer diagnosis and management. In gynecological malignancies, this modality has assumed greater responsibility, particularly in the evaluation of cervical and endometrial cancers. In addition to conventional imaging, innovative techniques such as dynamic contrast-enhanced MRI and diffusion-weighted MRI show promise in offering early assessment of tumor response. This paper reviews the current role of MRI in gynecological cancers and highlights the potential of novel techniques in improving patient care.

scholarly journals Imaging of larynx: Diagnostic value of computed tomography and magnetic resonance imaging

2009 ◽  
Vol 56 (3) ◽  
pp. 39-44
Author(s):  
R.M. Maksimovic ◽  
B.A. Banko ◽  
J.P. Milovanovic
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Regional Lymph Node ◽  
Diagnostic Value ◽  
Resonance Imaging ◽  
Precise Diagnosis ◽  
Node Metastases ◽  
Magnetic Resonance Imaging Mri

Computed tomography (CT) and magnetic resonance imaging (MRI) are enabling more precise diagnosis and treatment planning in patients with diseases of the larynx. The aim of this article is to describe the role of these methods in assessment of the laringeal diseases and key local anatomic characteristics important for spread of the disease. CT and MRI have a valuable contribution to the staging of the tumors due to the possibility to show the relationship to the ventricular complex, involvement of the subumucosal spaces, defining craniocaudal and anterposterior extension, laringeal cartilage invasion, as well as regional lymph node metastases.

scholarly journals Structural disconnectivity in schizophrenia: a diffusion tensor magnetic resonance imaging study

2003 ◽  
Vol 182 (5) ◽  
pp. 439-443 ◽  
Author(s):  
J. Burns ◽  
D. Job ◽  
M. E. Bastin ◽  
H. Whalley ◽  
T. Macgillivray ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Fractional Anisotropy ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Uncinate Fasciculus ◽  
Arcuate Fasciculus ◽  
Resonance Imaging ◽  
White Matter Tracts

BackgroundThere is growing evidence that schizophrenia is a disorder of cortical connectivity Specifically, frontotemporal and frontoparietal connections are thought to be functionally impaired. Diffusion tensor magnetic resonance imaging (DT–MRI) is a technique that has the potential to demonstrate structural disconnectivity in schizophrenia.AimsTo investigate the structural integrity of frontotemporal and frontoparietal white matter tracts in schizophrenia.MethodThirty patients with DSM–IV schizophrenia and thirty matched control subjects underwent DT–MRI and structural MRI. Fractional anisotropy – an index of the integrity of white matter tracts – was determined in the uncinate fasciculus, the anterior cingulum and the arcuate fasciculus and analysed using voxel-based morphometry.ResultsThere was reduced fractional anisotropy in the left uncinate fasciculus and left arcuate fasciculus in patients with schizophrenia compared with controls.ConclusionsThe findings of reduced white matter tract integrity in the left uncinate fasciculus and left arcuate fasciculus suggest that there is frontotemporal and frontoparietal structural disconnectivity in schizophrenia.

The role of diffusion tensor imaging in idiopathic normal pressure hydrocephalus: A literature review

2020 ◽  
pp. 197140092097515
Author(s):  
Irene Grazzini ◽  
Duccio Venezia ◽  
Gian Luca Cuneo
Keyword(s):  
Diffusion Tensor Imaging ◽  
Normal Pressure Hydrocephalus ◽  
Clinical Symptoms ◽  
Diffusion Tensor ◽  
Clinical History ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Csf Shunt ◽  
Magnetic Resonance Imaging Mri

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.

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