The Use of Magnetic Resonance Imaging for the Evaluation of the Porcine Intervertebral Disc Condition Under Treatment

Abstract

One of the methods of evaluation of degenerative disc disease therapies' effectiveness is the use of animal models and magnetic resonance imaging (MRI), for the evaluation of the degree of damage and possible subsequent regeneration of intervertebral discs (IVDs). The purpose of our study was to propose the methodology that can be used for assessing the condition of the porcine IVDs based on scans obtained in MRI study. Our research is based on the MRI scans obtained for the purpose of evaluation of the process of IVDs regeneration after administration of mesenchymal stem cells isolated from bone marrow after the damage caused by the surgical laser vaporization. Proposed method of segmentation utilizes basic methods of digital image processing implemented with the use of Matlab environment. The outcome of the described method is binary mask giving direct information about locations of IVDs in MRI scans. We present the results of the IVD condition evaluation with the use of described method. We also present differences that may appear in the assessment of the same cases based on different cross-sections of the same MRI research. (1) The use of coronal imaging plane is recommended to use, as it can be indicated as more reliable than sagittal. (2) Use of the basic geometrical shapes as the discs' shape approximation can lead to significant errors in the evaluation of the experiment results-the borders of IVDs should be determined using more complex shapes, i.e. considering the anatomy.

Minimally Invasive Intradiscal Delivery of BM-MSCs via Fibrous Microscaffold Carriers

“…The L2/L3 disc was considered the reference disc (not damaged, i.e., retaining 100% MRI signal intensity). The methodology used to assess the degree of disc damage was described by Lipinśki et al 50 The T2-weighted signal was significantly decreased in the damaged disc (L5/L6) without cells and MS (Figure 4E,F). In the case of BM-MSC delivery on microscaffolds, a significantly low signal intensity was observed for PLLA/CS.…”

“…An algorithm for normalizing MRI signal intensity was employed to mitigate this influence. 50 However, the utilization of animals in the growth stage was necessary due to their larger size at a later stage and the logistical challenges associated with transporting and positioning them within the MRI scanner. The issues raised also affected the duration of the experiment, which was only 4 weeks.…”

“…The L2/L3 disc was considered the reference disc (not damaged, i.e., retaining 100% MRI signal intensity). The methodology used to assess the degree of disc damage was described by Lipiński et al…”

“…The choice of animal model shown here has inherent limitations, with one significant drawback being the age of the animals and the concurrent tissue growth, including the intervertebral disc and intervertebral spaces. An algorithm for normalizing MRI signal intensity was employed to mitigate this influence . However, the utilization of animals in the growth stage was necessary due to their larger size at a later stage and the logistical challenges associated with transporting and positioning them within the MRI scanner.…”