Minimally Invasive Therapy. 2014;23:247–251
ORIGINAL ARTICLE
Relative anterior safe area for invasive procedures in the human brain: Diffusion tensor tractography
SUNG HO JANG & HYEOK GYU KWON Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Daegu, Republic of Korea
Abstract Objective: Many interventions, including surgery, procedures of shunt operation, or radiotherapy could result in neural injury of the brain. However, research to prevent or minimize injury of neural tracts has been overlooked. Material and methods: We recruited 41 healthy subjects. Diffusion tensor images were acquired and five neural tracts were reconstructed (corticospinal tract, corticoreticular pathway, arcuate fasciculus, cingulum, and superior longitudinal fasciculus). We defined the safe area, which is an area free from any trajectory of five neural tracts: the medial boundary - the most lateral point free from any trajectory of five neural tracts, the posterior boundary - the most anterior point free from any trajectory of five neural tracts. Results: Medial boundaries of the safe area in the cortex, centrum semiovale, corona radiata, and internal capsule were located at an average of 0 mm, 12.28 mm, 12.43 mm, and 10.34 mm laterally from the midline, respectively, and the posterior boundaries were located at an average of 1.30 mm, 4.26 mm, 7.05 mm, and 5.74 mm from the ACL, respectively. In addition, we found that the common safe areas for all four axial levels were located at 13.44 mm (medial boundary) and 9.35 mm (posterior boundary). Conclusion: We identified a relatively safe area for the performance of invasive procedures in the anterior portion of the human brain.
Key words: Invasive procedures, external ventricular drainage, safe area, diffusion tensor tractography
Introduction Surgery or invasive intervention is often required for the treatment of some brain pathologies. Many interventions, including surgery, procedures of shunt operation, or radiotherapy could result in neural injury of the brain (1,2). These interventions have been performed based on known neuroanatomy or experience. Therefore, anatomical identification of a safe area for the performance of invasive interventions could provide useful information for clinicians in the neuroscience field. Diffusion tensor tractography (DTT), which is derived from diffusion tensor imaging (DTI), has enabled visualization and localization of neural tracts in three dimensions (3). Many studies using DTT have reported on identification and visualization of various neural tracts located in the anterior portion of
the human brain, including the corticospinal tract (CST), corticoreticular pathway (CRP), arcuate fasciculus (AF), superior longitudinal fasciculus (SLF), fornix, and others (4–10). However, no DTT study on the safe area has been reported so far. In the current study, using DTT, we attempted to identify the safe area in the anterior portion of the human brain.
Material and methods Subjects We recruited 41 healthy subjects (male: 22, female: 19, mean age: 36.7 ± 12 years, range: 20–61 years) with no previous history of neurological, physical, or psychiatric illness. All subjects understood the purpose of the study and provided written informed
Correspondence: Hyeok Gyu Kwon, Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, 317-1, Daemyungdong, Namku, Daegu, 705-717, Republic of Korea. Fax: +82 53 620 3269. E-mail: [email protected] ISSN 1364-5706 print/ISSN 1365-2931 online 2014 Informa Healthcare DOI: 10.3109/13645706.2014.882360
248
S. H. Jang & H. G. Kwon
consent prior to participation. The study protocol was approved by the Institutional Review Board of a university hospital.
image (blue color) (5,13): For the CRP, ROI 1 reticular formation of the medulla on the axial image, and ROI 2 - tegmentum of the midbrain on the axial image (10,14). For the cingulum, ROI 1 - anterior portion of the cingulum area on the coronal image (green color), and ROI 2 - posterior portion of the cingulum area on the coronal image (green color) (6). For the SLF, ROI 1 - a triangular shape just lateral to the CST near the anterior horn of the lateral ventricle on the coronal image, ROI 2 - a triangular shape near the posterior horn of the lateral ventricle where the tracts ran from posterior to anterior on the coronal image (9). For the AF, ROI 1 - deep white matter of the posterior parietal portion of the SLF on the axial image (green color), and ROI 2 - the posterior temporal lobe on the axial image (blue color) (7). Fiber tracking was started at any seed voxel with a fractional anisotropy (FA) >0.2 and ended at a voxel with a FA of
ORIGINAL ARTICLE
Relative anterior safe area for invasive procedures in the human brain: Diffusion tensor tractography
SUNG HO JANG & HYEOK GYU KWON Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Daegu, Republic of Korea
Abstract Objective: Many interventions, including surgery, procedures of shunt operation, or radiotherapy could result in neural injury of the brain. However, research to prevent or minimize injury of neural tracts has been overlooked. Material and methods: We recruited 41 healthy subjects. Diffusion tensor images were acquired and five neural tracts were reconstructed (corticospinal tract, corticoreticular pathway, arcuate fasciculus, cingulum, and superior longitudinal fasciculus). We defined the safe area, which is an area free from any trajectory of five neural tracts: the medial boundary - the most lateral point free from any trajectory of five neural tracts, the posterior boundary - the most anterior point free from any trajectory of five neural tracts. Results: Medial boundaries of the safe area in the cortex, centrum semiovale, corona radiata, and internal capsule were located at an average of 0 mm, 12.28 mm, 12.43 mm, and 10.34 mm laterally from the midline, respectively, and the posterior boundaries were located at an average of 1.30 mm, 4.26 mm, 7.05 mm, and 5.74 mm from the ACL, respectively. In addition, we found that the common safe areas for all four axial levels were located at 13.44 mm (medial boundary) and 9.35 mm (posterior boundary). Conclusion: We identified a relatively safe area for the performance of invasive procedures in the anterior portion of the human brain.
Key words: Invasive procedures, external ventricular drainage, safe area, diffusion tensor tractography
Introduction Surgery or invasive intervention is often required for the treatment of some brain pathologies. Many interventions, including surgery, procedures of shunt operation, or radiotherapy could result in neural injury of the brain (1,2). These interventions have been performed based on known neuroanatomy or experience. Therefore, anatomical identification of a safe area for the performance of invasive interventions could provide useful information for clinicians in the neuroscience field. Diffusion tensor tractography (DTT), which is derived from diffusion tensor imaging (DTI), has enabled visualization and localization of neural tracts in three dimensions (3). Many studies using DTT have reported on identification and visualization of various neural tracts located in the anterior portion of
the human brain, including the corticospinal tract (CST), corticoreticular pathway (CRP), arcuate fasciculus (AF), superior longitudinal fasciculus (SLF), fornix, and others (4–10). However, no DTT study on the safe area has been reported so far. In the current study, using DTT, we attempted to identify the safe area in the anterior portion of the human brain.
Material and methods Subjects We recruited 41 healthy subjects (male: 22, female: 19, mean age: 36.7 ± 12 years, range: 20–61 years) with no previous history of neurological, physical, or psychiatric illness. All subjects understood the purpose of the study and provided written informed
Correspondence: Hyeok Gyu Kwon, Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, 317-1, Daemyungdong, Namku, Daegu, 705-717, Republic of Korea. Fax: +82 53 620 3269. E-mail: [email protected] ISSN 1364-5706 print/ISSN 1365-2931 online 2014 Informa Healthcare DOI: 10.3109/13645706.2014.882360
248
S. H. Jang & H. G. Kwon
consent prior to participation. The study protocol was approved by the Institutional Review Board of a university hospital.
image (blue color) (5,13): For the CRP, ROI 1 reticular formation of the medulla on the axial image, and ROI 2 - tegmentum of the midbrain on the axial image (10,14). For the cingulum, ROI 1 - anterior portion of the cingulum area on the coronal image (green color), and ROI 2 - posterior portion of the cingulum area on the coronal image (green color) (6). For the SLF, ROI 1 - a triangular shape just lateral to the CST near the anterior horn of the lateral ventricle on the coronal image, ROI 2 - a triangular shape near the posterior horn of the lateral ventricle where the tracts ran from posterior to anterior on the coronal image (9). For the AF, ROI 1 - deep white matter of the posterior parietal portion of the SLF on the axial image (green color), and ROI 2 - the posterior temporal lobe on the axial image (blue color) (7). Fiber tracking was started at any seed voxel with a fractional anisotropy (FA) >0.2 and ended at a voxel with a FA of
