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Hippocampal spatial position evaluation on MRI for research and clinical practice.

Mrzílkova J, Koutela A, Kutová M, Patzelt M, Ibrahim I, Al-Kayssi D, Bartoš A, Řípová D, Čermáková P, Zach P - PLoS ONE (2014)

Bottom Line: We found that 1) hippocampal area of nat images is larger compared to hipp images, area of the nat images is equal to the AC-PC images and area of the hipp images is smaller compared to AC-PC images, 2) hippocampal area together with the area of the temporal horn for nat images is larger compared to hipp images, area of the hipp images is smaller compared to the AC-PC images and area of the nat images is smaller compared to the AC-PC images.The conclusion is that the measured area of the hippocampus in the native MRI is almost the same as the area of MRI reoriented only into the AC-PC axis.Surprising finding was that rotation of both AC-PC and hipp line towards x-axis among patients varies up to 35° and the same is true for the skull rotation so that it is not only a matter of the brain position.

View Article: PubMed Central - PubMed

Affiliation: Institute of Anatomy, Third Faculty of Medicine, Charles University, Ruská 87, 100 00 Prague 10, Czech Republic.

ABSTRACT
In clinical practice as well as in many volumetric studies we use different reorientations of the brain position towards x and y axis on the magnetic resonance imaging (MRI) scans. In order to find out whether it has an overall effect on the resulting 2D data, manual hippocampal area measurements and rotation variability of the brain (in two reoriented axes) and the skull were performed in 23 Alzheimer's disease patients and 31 healthy controls. After the MRI scanning, native brain scans (nat) were reoriented into the two different artificial planes (anterior commissure-posterior commissure axis (AC-PC) and hippocampal horizontal long axis (hipp)). Hippocampal area and temporal horn of the lateral ventricle was measured manually using freeware Image J program. We found that 1) hippocampal area of nat images is larger compared to hipp images, area of the nat images is equal to the AC-PC images and area of the hipp images is smaller compared to AC-PC images, 2) hippocampal area together with the area of the temporal horn for nat images is larger compared to hipp images, area of the hipp images is smaller compared to the AC-PC images and area of the nat images is smaller compared to the AC-PC images. The conclusion is that the measured area of the hippocampus in the native MRI is almost the same as the area of MRI reoriented only into the AC-PC axis. Therefore, when performing 2D area studies of the hippocampus or in the clinical practice we recommend usage of not-reoriented MRI images or to reorient them into the AC-PC axis. Surprising finding was that rotation of both AC-PC and hipp line towards x-axis among patients varies up to 35° and the same is true for the skull rotation so that it is not only a matter of the brain position.

No MeSH data available.


Related in: MedlinePlus

a,b,c Examples of the sagittal view of the right hippocampus on the MRI in one native and two reoriented axis.MRI sections were selected according to the best visibility of the of the hippocampus on the sagittal sections (its long or dorsoventral axis), a) position of the hippocampus on the “native” MRI scan, b) reorientation of the “native” MRI scan into the hipo-axis axis (where long axis of the hippocampus is parallel to the horizontal axis), c) reorientation of the “native” MRI scan into the CA-CP. White lines represent long axis of the hippocampus.
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pone-0115174-g001: a,b,c Examples of the sagittal view of the right hippocampus on the MRI in one native and two reoriented axis.MRI sections were selected according to the best visibility of the of the hippocampus on the sagittal sections (its long or dorsoventral axis), a) position of the hippocampus on the “native” MRI scan, b) reorientation of the “native” MRI scan into the hipo-axis axis (where long axis of the hippocampus is parallel to the horizontal axis), c) reorientation of the “native” MRI scan into the CA-CP. White lines represent long axis of the hippocampus.

Mentions: The MRI images were exported as a multiple data format files into a standard computer. The MRI images of the brains were then converted into the stack of files by the MRIcro freeware and analyzed on Image J freeware. The areas of the hippocampi in (mm2) and hippocampus with temporal horn of the lateral ventricle (both at the level of the transition of alveus into the hippocampal body) were manually delineated independently by two experienced neuroanatomists. Hippocampal areas solely and collectively with the temporal horn of the lateral ventricle areas were measured in the three different rotational scan stacks of the MRI. Firstly, we measured areas in the “native” (nat) unaltered MRI scan stacks (Fig. 1a) as we obtained it from the MRI scanner. Secondly, we measured areas in the MRI scan stacks that were rotated using the MRIcro program so that the hippocampal long axis in the sagittal projection was parallel to the x-axis (hipp). Finally, the MRI scan stacks once again were rotated using the MRIcro program so that the sagittal projection line connecting the AC-PC was parallel to the x – axis (AC-PC). The areas of the hippocampi and hippocampus together with temporal horn of the lateral ventricle were calculated separately and adjusted to the areas of the brain and skull at the frontal cross-section at the level of anterior commissure; to exclude the impact of the brain and the skull size. The areas were adjusted according to formula (area of the hippocampus/area of the brain (skull) * 100. We did not observe statistically significant differences between adjusted and non-adjusted areas (unpublished results) so that we used in the calculations data w/o brain or skull adjustment.


Hippocampal spatial position evaluation on MRI for research and clinical practice.

Mrzílkova J, Koutela A, Kutová M, Patzelt M, Ibrahim I, Al-Kayssi D, Bartoš A, Řípová D, Čermáková P, Zach P - PLoS ONE (2014)

a,b,c Examples of the sagittal view of the right hippocampus on the MRI in one native and two reoriented axis.MRI sections were selected according to the best visibility of the of the hippocampus on the sagittal sections (its long or dorsoventral axis), a) position of the hippocampus on the “native” MRI scan, b) reorientation of the “native” MRI scan into the hipo-axis axis (where long axis of the hippocampus is parallel to the horizontal axis), c) reorientation of the “native” MRI scan into the CA-CP. White lines represent long axis of the hippocampus.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4264873&req=5

pone-0115174-g001: a,b,c Examples of the sagittal view of the right hippocampus on the MRI in one native and two reoriented axis.MRI sections were selected according to the best visibility of the of the hippocampus on the sagittal sections (its long or dorsoventral axis), a) position of the hippocampus on the “native” MRI scan, b) reorientation of the “native” MRI scan into the hipo-axis axis (where long axis of the hippocampus is parallel to the horizontal axis), c) reorientation of the “native” MRI scan into the CA-CP. White lines represent long axis of the hippocampus.
Mentions: The MRI images were exported as a multiple data format files into a standard computer. The MRI images of the brains were then converted into the stack of files by the MRIcro freeware and analyzed on Image J freeware. The areas of the hippocampi in (mm2) and hippocampus with temporal horn of the lateral ventricle (both at the level of the transition of alveus into the hippocampal body) were manually delineated independently by two experienced neuroanatomists. Hippocampal areas solely and collectively with the temporal horn of the lateral ventricle areas were measured in the three different rotational scan stacks of the MRI. Firstly, we measured areas in the “native” (nat) unaltered MRI scan stacks (Fig. 1a) as we obtained it from the MRI scanner. Secondly, we measured areas in the MRI scan stacks that were rotated using the MRIcro program so that the hippocampal long axis in the sagittal projection was parallel to the x-axis (hipp). Finally, the MRI scan stacks once again were rotated using the MRIcro program so that the sagittal projection line connecting the AC-PC was parallel to the x – axis (AC-PC). The areas of the hippocampi and hippocampus together with temporal horn of the lateral ventricle were calculated separately and adjusted to the areas of the brain and skull at the frontal cross-section at the level of anterior commissure; to exclude the impact of the brain and the skull size. The areas were adjusted according to formula (area of the hippocampus/area of the brain (skull) * 100. We did not observe statistically significant differences between adjusted and non-adjusted areas (unpublished results) so that we used in the calculations data w/o brain or skull adjustment.

Bottom Line: We found that 1) hippocampal area of nat images is larger compared to hipp images, area of the nat images is equal to the AC-PC images and area of the hipp images is smaller compared to AC-PC images, 2) hippocampal area together with the area of the temporal horn for nat images is larger compared to hipp images, area of the hipp images is smaller compared to the AC-PC images and area of the nat images is smaller compared to the AC-PC images.The conclusion is that the measured area of the hippocampus in the native MRI is almost the same as the area of MRI reoriented only into the AC-PC axis.Surprising finding was that rotation of both AC-PC and hipp line towards x-axis among patients varies up to 35° and the same is true for the skull rotation so that it is not only a matter of the brain position.

View Article: PubMed Central - PubMed

Affiliation: Institute of Anatomy, Third Faculty of Medicine, Charles University, Ruská 87, 100 00 Prague 10, Czech Republic.

ABSTRACT
In clinical practice as well as in many volumetric studies we use different reorientations of the brain position towards x and y axis on the magnetic resonance imaging (MRI) scans. In order to find out whether it has an overall effect on the resulting 2D data, manual hippocampal area measurements and rotation variability of the brain (in two reoriented axes) and the skull were performed in 23 Alzheimer's disease patients and 31 healthy controls. After the MRI scanning, native brain scans (nat) were reoriented into the two different artificial planes (anterior commissure-posterior commissure axis (AC-PC) and hippocampal horizontal long axis (hipp)). Hippocampal area and temporal horn of the lateral ventricle was measured manually using freeware Image J program. We found that 1) hippocampal area of nat images is larger compared to hipp images, area of the nat images is equal to the AC-PC images and area of the hipp images is smaller compared to AC-PC images, 2) hippocampal area together with the area of the temporal horn for nat images is larger compared to hipp images, area of the hipp images is smaller compared to the AC-PC images and area of the nat images is smaller compared to the AC-PC images. The conclusion is that the measured area of the hippocampus in the native MRI is almost the same as the area of MRI reoriented only into the AC-PC axis. Therefore, when performing 2D area studies of the hippocampus or in the clinical practice we recommend usage of not-reoriented MRI images or to reorient them into the AC-PC axis. Surprising finding was that rotation of both AC-PC and hipp line towards x-axis among patients varies up to 35° and the same is true for the skull rotation so that it is not only a matter of the brain position.

No MeSH data available.


Related in: MedlinePlus