Cartilage defects occur in approximately 12% of the population and can result in significant function impairment and reduction in quality of life. Evidence for the variety of surgical treatments available is inconclusive. This study aimed to compare the clinical outcomes of patients with symptomatic cartilage defects treated with matrix-induced autologous chondrocyte implantation (MACI or microfracture (MF). Included patients were >or= 18 and

Abstract-Arteriogenesis has been associated with the presence of monocytes/macrophages within the collateral vessel wall. Induced macrophage migration in vivo is driven by the binding of monocyte chemoattractant protein-1 (MCP-1, or CCL2 in the new nomenclature) to the CCR2-chemokine receptor on macrophages. To determine whether the CCL2-CCR2 signaling pathway is involved in the accumulation of macrophages in growing collateral vessels, we used mice that are deficient in CCR2 in a model of experimental arterial occlusion and collateral vessel growth. In an in vitro CCL2-driven chemotaxis assay, mononuclear cells isolated from wild-type BALB/c mice exhibited CCL2 concentration-dependent migration, whereas this migration was abolished in cells from CCR2 Ϫ/Ϫ mice on a BALB/c genetic background. In vivo, blood flow recovery as measured by laser Doppler (LDI) and MRI (MRI) was impaired in CCR2 Ϫ/Ϫ mice on either the BALB/c or C57BL/6 genetic backgrounds. Three weeks after femoral artery ligation, LDI perfusion ratio of operated versus nonoperated distal hindlimb in BALB/c wild-type mice increased to 0.45Ϯ0.06 and in CCR2 Ϫ/Ϫ animals only to 0.21Ϯ0.03 (PϽ0.01). In C57BL/6 mice, ratio increased to 0.96Ϯ0.09 and 0.85Ϯ0.08 (PϽ0.05), respectively. MRI at 3 weeks (0.76Ϯ0.06 versus 0.62Ϯ0.01; PϽ0.05) and hemoglobin oxygen saturation measurements confirmed these findings. Active foot movement score significantly decreased and gastrocnemius muscle atrophy was significantly greater in CCR2 Ϫ/Ϫ mice. Morphometric analysis showed a lesser increase in collateral vessel diameters in CCR2 Ϫ/Ϫ mice. Importantly, the number of invaded monocytes/macrophages in the perivascular space of collateral arteries of CCR2 Ϫ/Ϫ animals was dramatically reduced in comparison to wild-type mice. In conclusion, our results demonstrate that the CCR2 signaling pathway is essential for efficient collateral artery growth.

Background and Purpose-Brain edema is a life-threatening consequence of stroke and leads to an extension of the affected tissue. The space-occupying effect due to brain edema can be quantified in rat stroke models with the use of MRI. The present study was performed to test 2 hypotheses: (1) Can quantification of the space-occupying effect due to brain edema serve as a noninvasive measure for brain water content? (2) Does morphometric assessment of brain swelling allow determination of true infarct size on MRI after correction for the space-occupying effect of edema? Methods-Thirty rats were subjected to permanent suture middle cerebral artery occlusion. MRI was performed after 6 or 24 hours, and hemispheric swelling was assessed morphometrically. Interobserver and intraobserver agreements were determined for MRI measurements. In study I, the space-occupying effect due to brain edema was correlated with the absolute brain water content by the wet/dry method. In study II, lesion volumes corrected and uncorrected for edema were calculated on MRI and on TTC staining and compared. Results-Interobserver and intraobserver agreements for MRI measurements were excellent (rՆ0.97). Brain water content and hemispheric swelling correlated well after 6 and 24 hours (rՆ0.95). Corrected lesion volumes correlated with rϭ0.78 between TTC staining and MRI. Without edema correction, lesion volumes were overestimated by 20.3% after 6 hours and by 29.6% after 24 hours of ischemia. Conclusions-Morphometric assessment of hemispheric swelling on MRI can determine the increase in absolute brain water content noninvasively and can also provide ischemic lesion volumes corrected for brain edema.

The combined MR protocol is both reliable and sensitive in comparison with 16-MDCT in the diagnosis of pulmonary embolism. MR perfusion imaging is sensitive for the detection of pulmonary embolism, whereas real-time MR and MR angiography are specific.