Agenesis of the corpus callosum - 3D reconstruction of Probst bundles

Case Discussion

In patients with agenesis of the corpus callosum, tractography has been shown to be able to objectivate atypical connection fibers secondary to the failure of normal corpus callosum formation along the midline. These fibers are called Probst bundles.

Data acquisition

A 1.5 T Philips Achieva was used. DTI data were acquired using a single-shot echo planar imaging (EPI) sequence with SENSE parallel imaging^* (EPI factor = 59). Spin echo technique (TR = 11090 ms; TE = 107 ms; flip angle = 90°; nex = 2). The imaging matrix was 112 x 112, with a field of view of 224 x 224 mm. The image orientation was axial, with a 2.0 mm slice thickness (slice gap = 0 mm), which was aligned parallel to the anterior-posterior commissure line. A total of 60 slices covered the entire cerebral hemispheres and the brainstem. The diffusion weighting was encoded along 32 independent orientations, with a maximum b-value = 800 s/mm². The scanning time of one dataset was about 12 min. A coregistered T₁-weighted 3D gradient echo was also recorded for anatomical guidance.

* SENSE parallel imaging was used to reduce the length of the EPI-train, thereby reducing susceptibility related distortions.

Reconstruction of tracts

The 3D tract reconstruction was performed using the FACT (Fiber Assignment by Continuous Tracking) method. Fractional anisotropy (FA) threshold = 0.18.

Acknowledgments

A Politi, MD and G M Latagliata, MD.

Disclosure: I, Francesco Sciacca, have no actual or potential ethical or financial conflict of interest in relation to this device. This case is not intended to be a personal endorsement or recommendation of this product.