- Email: [email protected]
1001 Diffusion tensor MRI and tractography of the sacral plexus
1001 - Diffusion tensor MRI and tractography of the sacral plexus
Page 1 of 2
e1001 Diffusion tensor MRI and tractography of the sacral plexus 1
1
2
Jansonius A. , Van Der Jagt P.K.N. , Leemans A. , Dik P. 1
1
University Children's Hospitals UMC Utrecht and AMC Amsterdam, 2
Dept. of Paediatric Urology, Utrecht, The Netherlands, University Medical Centre Utrecht, Dept. of Radiology, Image Sciences Institute, Utrecht, The Netherlands INTRODUCTION & OBJECTIVES: The exact mechanism of neurogenic bladder in children with spina bifida is unknown. More insight is needed in the anatomy and branching of the sacral plexus. The objective of this study is to determine the feasibility of diffusion tensor MRI with fibre tractography. This technique virtually reconstructs nerve fibre pathways from the underlying diffusion data. Thus far no literature exists about the use of diffusion tensor imaging (DTI) for the sacral plexus. We aspired to visualise the sacral plexus and to assess its architectural and microstructural characteristics. Also, clinical feasibility of DTI was investigated in a child with spina bifida and neurogenic bladder dysfunction. MATERIAL & METHODS: A 12 year old boy with spina bifida and 10 healthy adults underwent DTI on a 3.0 Tesla system. Along with the tractography several microstructural properties of the nerve fibres were determined with the ExploreDTI diffusion MRI toolbox: apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD). RESULTS: The sacral plexus was visualised in all cases (figure 1), giving 3D insight in the anatomy of the nerves L4 to S3. The pelvic nerve was identified in 4 adults. The architectural configuration was comparable in all volunteers. No significant differences were found in any microstructural parameter between the individual right and left sided nerves, nor between the volunteers. Furthermore, clinical feasibility of DTI and tractography in a child with spina bifida is demonstrated. The L4 to S3 nerves were seen without anatomical
file://F:\RamShankar\April\04-05-12\Cip\Sour\1001.html
4/7/2012
1001 - Diffusion tensor MRI and tractography of the sacral plexus
Page 2 of 2
e1001a differences compared to the healthy volunteers. However, at L5 to S2, no proper tractography was possible for the nerve segments closest to the vertebrae. This level corresponds with the initial myelomeninogocele.
Figure 1. Tractography of a normal sacral plexus. CONCLUSIONS: This study shows, for the first time, the possibility of DTI and fibre tractography of the nerves of the sacral plexus in healthy volunteers. In addition, our results demonstrate the feasibility of these techniques in a 12 year old spina bifida patient. The area corresponding with the neural tube defect could not be tracked entirely. This might indicate an abnormal diffusion and changed microstructural properties in these nerve segments. Further DTI with patients is needed to determine whether this could be part of the aetiology of neurogenic bladder dysfunction in spina bifida patients.
file://F:\RamShankar\April\04-05-12\Cip\Sour\1001.html
4/7/2012
Page 1 of 2
e1001 Diffusion tensor MRI and tractography of the sacral plexus 1
1
2
Jansonius A. , Van Der Jagt P.K.N. , Leemans A. , Dik P. 1
1
University Children's Hospitals UMC Utrecht and AMC Amsterdam, 2
Dept. of Paediatric Urology, Utrecht, The Netherlands, University Medical Centre Utrecht, Dept. of Radiology, Image Sciences Institute, Utrecht, The Netherlands INTRODUCTION & OBJECTIVES: The exact mechanism of neurogenic bladder in children with spina bifida is unknown. More insight is needed in the anatomy and branching of the sacral plexus. The objective of this study is to determine the feasibility of diffusion tensor MRI with fibre tractography. This technique virtually reconstructs nerve fibre pathways from the underlying diffusion data. Thus far no literature exists about the use of diffusion tensor imaging (DTI) for the sacral plexus. We aspired to visualise the sacral plexus and to assess its architectural and microstructural characteristics. Also, clinical feasibility of DTI was investigated in a child with spina bifida and neurogenic bladder dysfunction. MATERIAL & METHODS: A 12 year old boy with spina bifida and 10 healthy adults underwent DTI on a 3.0 Tesla system. Along with the tractography several microstructural properties of the nerve fibres were determined with the ExploreDTI diffusion MRI toolbox: apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD). RESULTS: The sacral plexus was visualised in all cases (figure 1), giving 3D insight in the anatomy of the nerves L4 to S3. The pelvic nerve was identified in 4 adults. The architectural configuration was comparable in all volunteers. No significant differences were found in any microstructural parameter between the individual right and left sided nerves, nor between the volunteers. Furthermore, clinical feasibility of DTI and tractography in a child with spina bifida is demonstrated. The L4 to S3 nerves were seen without anatomical
file://F:\RamShankar\April\04-05-12\Cip\Sour\1001.html
4/7/2012
1001 - Diffusion tensor MRI and tractography of the sacral plexus
Page 2 of 2
e1001a differences compared to the healthy volunteers. However, at L5 to S2, no proper tractography was possible for the nerve segments closest to the vertebrae. This level corresponds with the initial myelomeninogocele.
Figure 1. Tractography of a normal sacral plexus. CONCLUSIONS: This study shows, for the first time, the possibility of DTI and fibre tractography of the nerves of the sacral plexus in healthy volunteers. In addition, our results demonstrate the feasibility of these techniques in a 12 year old spina bifida patient. The area corresponding with the neural tube defect could not be tracked entirely. This might indicate an abnormal diffusion and changed microstructural properties in these nerve segments. Further DTI with patients is needed to determine whether this could be part of the aetiology of neurogenic bladder dysfunction in spina bifida patients.
file://F:\RamShankar\April\04-05-12\Cip\Sour\1001.html
4/7/2012