Kim YH, et al. Clin Orthop Surg. 2017 Mar;9(1):1-9. https://doi.org/10.4055/cios.2017.9.1.1

To retrospectively determine the value of adding qualitative and quantitative axial diffusion-weighted (DW) imaging to standard spine magnetic resonance (MR) imaging to differentiate between acute osteoporotic and malignant compression fractures at 3.0 T. The institutional ethics committee approved this retrospective study and waived the requirement to obtain informed consent. The authors retrospectively analyzed 3.0-T MR images, including DW images (b values: 0, 800, and 1400 sec/mm(2)), in 62 patients with acute compression fractures. Three radiologists independently interpreted MR images for the presence of malignancy by using conventional MR images alone and in combination with axial DW images with qualitative and quantitative analysis. Apparent diffusion coefficients (ADCs) were measured within solid portion with careful use of a small region of interest (ROI). The Mann-Whitney U test was performed. There were 30 malignant and 32 acute osteoporotic compression fractures. At qualitative analysis, hyperintensity relative to spinal cord was more frequent in malignant compression fractures than in acute osteoporotic compression fractures (87% vs 22%, respectively; P < .001). Median ADCs of malignant fractures were significantly lower than those of benign fractures (P < .001). With conventional MR imaging alone, sensitivity, specificity, and accuracy were 100%, 94%, and 97%, respectively, for reader 1; 97%, 78%, and 87% for reader 2; and 100%, 84%, and 92% for reader 3. With conventional and DW MR imaging combined, sensitivity, specificity, and accuracy were 100%, 97%, and 98% for all three readers. The addition of DW imaging led to correct changes in diagnosis: Reader 1 improved by 1.6% (one of 62 fractures), reader 2 improved by 11% (seven of 62 fractures), and reader 3 improved by 6.5% (four of 62 fractures). The addition of axial DW imaging to a conventional MR imaging protocol improved diagnostic accuracy in the differentiation of acute osteoporotic from malignant compression fractures by measuring ADCs in the solid portion with careful use of a small ROI.

Animal experimental study. To present experimental evidence for mesenchymal cell therapy for spinal cord injury (SCI). Prior to clinical application of stem cell therapy for SCI, many critical issues have to be addressed including efficiency, safety, method of transplantation, and differentiation of the transplanted cells. Chronic contusive SCI was induced in 36 Sprague-Dawley rats and randomly assigned to the intralesional (IL), intravenous (IV), or control groups. At 6 weeks post injury, allogenic mesenchymal stem cells (MSCs, 1 × 10 cells) were transplanted either intralesionally or intravenously for the intervention groups. Engraftment of the transplanted MSCs was evaluated with PKH 26 staining. Differentiation was evaluated using double stain with neuronal and glial cell markers. Brain-derived neurotrophic factor and nerve growth factor (NGF) were used for neurotrophic factor expression. Basso, Beattie, and Bresnahan locomotor rating scale was used for evaluation of functional recovery. The estimated engraftment percentage of the transplanted cells in the IL group and IV group were 36.5%, and 15.5%, respectively. The engraftment of the transplanted MSCs was higher in the IL group than in the IV group. Most of the transplanted MSCs were colocalized with GFAP in both transplantation groups. Brain-derived neurotrophic factor and NGF expression (Western blot and real-time polymerase chain reaction) in the injured spinal cord was higher in both transplanted groups compared with those in the control group. At 6 weeks post transplantation, the mean Basso, Beattie, and Bresnahan locomotor scales in the IL, IV, and control groups were 5.63 ± 0.89, 5.63 ± 1.03, and 2.88 ± 0.44, respectively. The functional recovery seen in the rats that underwent transplantation was significantly better than that in the control group (P < 0.05). Although the number of engrafted cells and expression of neurotrophic factors were lower in the IV group than those in the IL group, both IL and IV transplantation of MSC in the chronic SCI gave a significant clinical improvement. However, there were no differences in differentiation of the transplanted cells between the IL group and IV group. Astrocytic differentiation of the transplanted cells was predominant. N/A.