+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Diffusional Kurtosis Imaging in Idiopathic Normal Pressure Hydrocephalus: Correlation with Severity of Cognitive Impairment


      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.



          Diffusional kurtosis imaging (DKI) is an emerging technique that describes diffusion of water molecules in terms of deviation from Gaussian distribution. This study investigated correlations between DKI metrics and cognitive function in patients with idiopathic normal pressure hydrocephalus (iNPH).

          Materials and Methods:

          DKI was performed in 29 iNPH patients and 14 age-matched controls. Mini-mental state examination (MMSE), frontal assessment battery (FAB), and trail making test A (TMT-A) were used as cognitive measures. Tract-based spatial statistics (TBSS) analyses were performed to investigate the between-group differences and correlations with the cognitive measures of the diffusion metrics, including mean kurtosis (MK), fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusivity (AD), and radial diffusivity (RD).


          In iNPH patients, FA and MK identified positive correlations with cognitive function in similar regions, predominantly in the frontal lobes ( P < 0.05, corrected for multiple comparisons). The frontoparietal subcortical white matter showed significant correlations with FAB and TMT-A across more extensive areas in MK analyses than in FA. ADC, AD, and RD analyses showed no significant correlations with MMSE and FAB, while negative correlation with TMT-A was observed in the limited portion of the frontal deep white matter.


          Both FA and MK correlated well with cognitive impairment in iNPH. The observed differences between FA and MK results suggest DKI may play a complementary role to conventional FA and ADC analyses, especially for evaluation of the subcortical white matter.

          Related collections

          Most cited references35

          • Record: found
          • Abstract: found
          • Article: not found

          Executive function and the frontal lobes: a meta-analytic review.

          Currently, there is debate among scholars regarding how to operationalize and measure executive functions. These functions generally are referred to as "supervisory" cognitive processes because they involve higher level organization and execution of complex thoughts and behavior. Although conceptualizations vary regarding what mental processes actually constitute the "executive function" construct, there has been a historical linkage of these "higher-level" processes with the frontal lobes. In fact, many investigators have used the term "frontal functions" synonymously with "executive functions" despite evidence that contradicts this synonymous usage. The current review provides a critical analysis of lesion and neuroimaging studies using three popular executive function measures (Wisconsin Card Sorting Test, Phonemic Verbal Fluency, and Stroop Color Word Interference Test) in order to examine the validity of the executive function construct in terms of its relation to activation and damage to the frontal lobes. Empirical lesion data are examined via meta-analysis procedures along with formula derivatives. Results reveal mixed evidence that does not support a one-to-one relationship between executive functions and frontal lobe activity. The paper concludes with a discussion of the implications of construing the validity of these neuropsychological tests in anatomical, rather than cognitive and behavioral, terms.
            • Record: found
            • Abstract: found
            • Article: not found

            Cerebral gliomas: diffusional kurtosis imaging analysis of microstructural differences.

            To characterize the non-Gaussian diffusion patterns of cerebral glioma microstructure with respect to the different glioma grades by using a new method called diffusional kurtosis (DK) imaging. In this study with institutional review board approval and patient consent, diffusional measures of mean kurtosis (MK), fractional anisotropy (FA), and apparent diffusion coefficient (ADC) were compared prospectively. Data were normalized to the contralateral white matter. A Mann-Whitney test was used to compare each histologic glioma subtype regarding the diffusion measurements. Receiver operating characteristic curves were used to test for the parameter with the best sensitivity and specificity for glioma grade discrimination. In 34 patients with cerebral gliomas (five World Health Organization [WHO] grade II astrocytomas, 13 WHO grade III astrocytomas, and 16 WHO grade IV glioblastomas multiforme), significantly different diffusion patterns were found among the three glioma groups. MK values increased with higher glioma malignancy, whereas ADCs tended to decrease with higher malignancy; FA values did not differ significantly among tumor groups. Significant differences between astrocytoma grades WHO II and WHO III were demonstrated only by DK values. Area under the receiver operating characteristic curve was highest for normalized MK (0.972) during testing to discriminate between low- and high-grade gliomas. This study demonstrates specific diffusion patterns for low- and high-grade gliomas, showing that DK imaging is able to depict microstructural changes within glioma tissue and is able to help differentiate among glioma grades. (c) RSNA, 2010.
              • Record: found
              • Abstract: found
              • Article: not found

              MR diffusion kurtosis imaging for neural tissue characterization.

              M Cheung, X. Wu (2010)
              In conventional diffusion tensor imaging (DTI), water diffusion distribution is described as a 2nd-order three-dimensional (3D) diffusivity tensor. It assumes that diffusion occurs in a free and unrestricted environment with a Gaussian distribution of diffusion displacement, and consequently that diffusion weighted (DW) signal decays with diffusion factor (b-value) monoexponentially. In biological tissue, complex cellular microstructures make water diffusion a highly hindered or restricted process. Non-monoexponential decays are experimentally observed in both white matter and gray matter. As a result, DTI quantitation is b-value dependent and DTI fails to fully utilize the diffusion measurements that are inherent to tissue microstructure. Diffusion kurtosis imaging (DKI) characterizes restricted diffusion and can be readily implemented on most clinical scanners. It provides a higher-order description of water diffusion process by a 2nd-order 3D diffusivity tensor as in conventional DTI together with a 4th-order 3D kurtosis tensor. Because kurtosis is a measure of the deviation of the diffusion displacement profile from a Gaussian distribution, DKI analyses quantify the degree of diffusion restriction or tissue complexity without any biophysical assumption. In this work, the theory of diffusion kurtosis and DKI including the directional kurtosis analysis is revisited. Several recent rodent DKI studies from our group are summarized, and DKI and DTI compared for their efficacy in detecting neural tissue alterations. They demonstrate that DKI offers a more comprehensive approach than DTI in describing the complex water diffusion process in vivo. By estimating both diffusivity and kurtosis, it may provide improved sensitivity and specificity in MR diffusion characterization of neural tissues. © 2010 John Wiley & Sons, Ltd.

                Author and article information

                Magn Reson Med Sci
                Magn Reson Med Sci
                Magnetic Resonance in Medical Sciences
                Japanese Society for Magnetic Resonance in Medicine
                03 February 2016
                : 15
                : 3
                : 316-323
                [1 ]Department of Radiology, Graduate School of Medicine, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
                [2 ]Department of Radiology, Juntendo University Graduate School of Medicine
                [3 ]Department of Neurosurgery, Juntendo University Graduate School of Medicine
                [4 ]Department of Radiological Sciences, Graduate School of Human Health Sciences
                Author notes
                [* ]Corresponding author, Phone: +81-3-5800-8666, Fax: +81-3-5800-8935, E-mail: kkamiya-tky@ 123456umin.ac.jp
                © 2016 Japanese Society for Magnetic Resonance in Medicine

                This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives International License.

                Major Paper

                normal pressure hydrocephalus,dementia,diffusional kurtosis imaging,diffusion tensor imaging


                Comment on this article