Ischemic Cerebral Tissue Response to Subventricular Zone Cell Transplantation Measured by Iterative Self-Organizing Data Analysis Technique Algorithm

Abstract

To investigate the changes of the ischemic lesion in rat brain after subventricular zone (SVZ) cell transplantation and the influence of the grafted cells on the appearance of angiogenesis, SVZ cells, superparamagnetically labeled, were intracisternally transplanted into the rat brain 48 h after onset of embolic stroke. A complete set of magnetic resonance (MR) images was acquired for all animals with (n = 8) and without (n = 3) cell grafting at approximately 24 h, 72 h, and weekly for 6 weeks after stroke. Transplanted cells were tracked by high-resolution three-dimensional gradient-echo images and the interaction between the cells and ischemic lesion was detected by ISODATA (Iterative SelfOrganizing Data Analysis Technique Algorithm) calculated from T 1 , T 2 and T 1sat maps. Tissue status from ISODATA was characterized by a specific signature, which represents the deviation from normal tissue in the feature space. Transplanted SVZ cells selectively migrated towards the ischemic side of the rat brain and approached the lesion boundary within 1-week after grafting. Cell treated rats exhibited a significant reduction of average lesion size compared with control rats (P < 0.05). A significant reduction of tissue signature (P < 0.001) induced by cell transplantation was localized to the position of grafted cells, and these sites exhibited stably restored cerebral blood flow (CBF) (approximately 85% of normal CBF). Angiogenesis was present in sites either immediately adjacent to or surrounded by the grafted cells. Our data indicate that map-ISODATA accurately and dynamically characterizes the ischemic lesion and its response to cell therapy.

Angiogenesis Detected After Embolic Stroke in Rat Brain Using Magnetic Resonance T2*WI

“…6 In the stroke rats treated with neural progenitor cells, the transplanted cells arrive at their destination within 1 week after grafting and angiogenesis activity occurs in sites either adjacent to or surrounded by the grafted cells. 22 In this situation, it is difficult to use the T 2 * to detect angiogenesis because the grafted cells are labeled with iron. While the other pattern, for control animals treated with saline, demonstrated that the regional K i values remained elevated from 1 to 6 weeks after stroke, as shown in the first row of K i maps in Figure 1.…”

Neurogenesis, Angiogenesis, and MRI Indices of Functional Recovery From Stroke

“…3,[5][6][7]62,65 These treatments revise brain architecture, including vascular changes associated with angiogenesis, neurogenesis, glial changes, reduction of scar tissue with treatment, increased presence of progenitor and mature oligodendrocytes after treatment, and changes in the white matter. 14,11,27,[65][66][67] Aspects of brain structural and angiogenic remodeling may be visible on MRI. 12,67,68 …”

“…14,11,27,[65][66][67] Aspects of brain structural and angiogenic remodeling may be visible on MRI. 12,67,68 …”

Permeability imaging in cerebrovascular diseases: applications and progress in research

“…Chen et al also found that the K trans map can predict clinical outcomes after stroke. K trans , as well as measurements from other sequences in MR, also confirmed the location and the size of the area of revascularization and angiogenesis [31]. Similar to its usefulness in detecting tumor angiogenesis, K trans is a sensitive parameter for the detection of early brain angiogenesis in post-stroke patients.…”