| Objective:To discuss the influence on MRI artifact of fixed prosthesis made of different alloy and different shape. To compare the relationship between the artifact of different fixed prosthesis and field strength,scanning sequence.To provide experimental evidence whether to remove fixed prosthesis and how to select field strength when MRI testing for head and neck was neededMethods:Chosen 16 commonly used metallic dental prosthesis as test samples,and the same shape and thickness of the plastic prosthesis with test samples as the control were produced.The water phantom should be scanned before test samples put in it,and then all kinds of plastic prosthesis(for the control)and all kinds of test samples were one by one put on the seat of water phantom to be scanned.We should keep consistent scanning position on 1.5T and 3.0T MR imagers,and at least one or two longitudinal scanning layer should pass the test samples centre,and choose the center layer to analyze.Used sketching software of Siemens and GE machines,and the artifact areas of test samples were measured,and then test with paired T-test by using software SPSS 11.0 (SPSS Inc.Chicago,Illinois).When p≤0.05,the experimental results have statistical significant difference.We could analyze the difference among the artifact areas of every test sample on 1.5T and 3.0T MR imagers. variance,and the results were statistical significance in the difference.2.The artifact areas caused by same metallic prosthesis with same thickness and different amount were used analysis of variance,and the results were statistical significance in the differences.The artifact areas caused by same metallic prosthesis with different thickness and same amount were used analysis of variance,and part of the results were statistical significance in the difference.3. Three kind of metallic dental prosthesis were tested with different field-strength and the same sequence of MRI. The artifact areas caused by three kind of metallic dental prosthesis were used paired t-test,and the results were statistical significance in the difference.4.Three kind of metallic dental prosthesis were tested with same field-strength and different sequence of MRI.The artifact areas caused by three kind of metallic dental prosthesis were used paired t-test,and the results were statistical significance in the difference.Conclusions:1.Ni-Cr alloy prosthesis,Co-Cr alloy prosthesis and Gold alloy prosthesis all can cause MRI artifacts. 2.The artifact areas of metallic dental prosthesis with same thickness and shape from small to large were:gold alloy |
PDF Full Text Request