ABSTRACT
PURPOSE: To compare the lesion detectability and conspicuity in traumatic brain injury on T-2 FFE , FLAIR and diffusion weighted imaging (DWI) sequences. MATERIALS AND METHODS: Thirty-three patients who underwent MR brain imaging after traumatic brain injury were reviewed. T-2 FFE, FLAIR and diffusion-weighted MR sequences were obtained and were compared in terms of the detectability and conspicuity of intra- and extra- axial lesions which showed abnormal signal intensities. RESULTS: Among 33 patients, a total of 108 lesions were found. T-2 FFE sequences detected 88(81%) of these, FLAIR sequences 91(84%), and diffusion-weighted sequences 57(52%). In the case of petechial hemorrhagic lesions, 16 were detected by T-2 FFE imaging but only one by FLAIR and one by DWI. Sixteen extra-axial lesions (73%) were detected by T-2 FFE, 21 (95%) by FLAIR, and 11(50%) by DWI. Lesion conspicuity on FLAIR images was judged superior to that on T-2 FFE and diffusion-weighted images in 42 lesions (75%). Eleven extra- axial Lesions (92%) were more conspicuous on FLAIR than on T-2 FFE and DWI. CONCLUSION: For detecting traumatic brain lesions and determining their conspicuity, FLAIR imaging was more useful than T-2 FFE and diffusion weighting, while T-2 FFE imaging was more sensitive for the detection of petechial hemorrhage. Although diffusion-weighted imaging was generally inferior to both FLAIR and T-2 FFE in terms of lesion detection and conspicuity, for some lesions it was superior. The results suggest that images obtained at each pulse sequence can be used as complementary imaging sequences, and that in traumatic brain injury, the acquisition of FLAIR, T-2 FFE and diffusion-weighted images is useful.
Subject(s)
Humans , Brain , Brain Injuries , Diffusion , Hemorrhage , NeuroimagingABSTRACT
PURPOSE: To evaluate the relative adhesion and migration rate of cultured human aortic endothelial cells onto modified stent material in vitro. MATERIALS AND METHODS: Flat 1 x 1cm square, stainless steel 316 L pieces(600 micrometer thick) were initially glow dis-charged to increase the polarity of the metal and were coated with 1 %polyhydroxyethylmethacrylate to which two different amino acid peptide sequences (GRGDY, GREDVY) were covalentlylinked via an amide to an amino-terminus, thus providing a known orientation of these covalently bound peptides.To stimulate implantation of a stent onto the intact arterial wall, human aortic endothelial cells were seeded andgrown to confluence on thick, firm collagen gel. The peptide coated steel pieces were then implanted on thisendothe-lialized surface and migration of HAEC to the surface was monitored and measured for ten days. The contactangle of steel was measured before and after glow-discharge treatment. RESULTS: Our results indicate that themigration and adhesion rate of HAEC to surfaces bearing either GRGDY or GREDVY adhesive peptide sequences wassignificantly higher than that of uncoated stainless steel. The contact angles of glow-discharged steel (eitherpositive or negative charge) were significantly lower, and this in-dicates the increased wettability of steel. Furthermore, migration to a GREDVY-coated surface was greater than to one coated with GRGDY. CONCLUSION: Theseresults indicate that a specific peptide sequence (GREDVY), together with positive glow-discharge treatment ofsteel can selectively enhance endothelial cell migration to metallic stent material.