| ObjectiveTo explore the effect of different delay times on the MR imaging qualities for the brachial plexus after contrast agent injection.Methods34 patients suspected with brachial plexus(BP)injury were recruited in this study,and divided into two groups randomly.There were 17 patients in each group.Every patient written consent forms were obtained prior to the scan.short tau inverse recovery(STIR)3D FSE was scanned in addition to routine clinical sequences on a GE MR 750 3.0 T whole body scanner equipped with an 8-channel neurovascular coil.The amount of contrast agent was0.1mmol/kg according to patients’ weight,the injection rate was 1.5ml/s,and 20 ml saline was injected at the same rate.The STIR3 D FSE were acquired pre-injection,and at different delay times(0,10,30 and 30 min for group1;5,15,25 and 35 min for group 2)post-injection of the contrast Gd-DTPA.The signal intensity(SI)and standard deviation(SD)of maximum intensity projection(MIP)images reconstructed by GE 4.6 workstation were calculated for region of interest(ROI)with area of 17mm2 on both sides of C6 peripheral nerves(ROInerve),in regions outside the anatomy(ROIbackground),and tissue adjacent to the peripheral nerves(ROItissue).then signal to noise ratio(SNR)and contrast to noise ratio(CNR)were caculated.The images were then scored by two senior radiologists.SPSS20.0software was used for statistical analysis.The SNR and CNR with the highest imaging delay time in the brachial plexus of the two groups were obtained,the statistical method was one-way analysis of variance.and the SNR and CNR with the best delay time in the two groups were compared by the independent sample t test,and the best delay time of the brachial plexus was shown after the injection of contrast agent.ResultsIn the first group,the SNR of the brachial plexus with non-contrast was 20.08 ± 4.70,the CNR was 6.66 ± 2.69,and the image score was 1.47±0.75.After the Gd-DTPA injection,The SNR was 6.66 ± 2.69 at the delay time of 0 minutes,the CNR was 11.81 ± 3.57,and the image score was 3.75±0.50;The SNR was 27.66 ± 6.04 at the delay time of 10 minutes,the CNR was 10.39 ± 3.76,and the image score was 3.00±0.00;The SNR was 22.61 ± 4.64 at the delay time of 20 minutes,the CNR was 9.05 ± 3.33,and the image score was 2.00±0.25;The SNR was 20.24 ± 5.87 at the delay time of 30 minutes,the CNR was 9.09 ± 3.79,and the image score was 1.50±0.50.(p < 0.05)There were statistical difference among them.In the second group,the SNR of the brachial plexus with non-contrast was 19.19 ± 7.61,the CNR was 6.25 ± 3.43,and the image score was 1.50±0.75.After the Gd-DTPA injection,The SNR was 30.16 ± 7.58 at the delay time of 5 minutes,the CNR was 11.42 ± 3.92,and the image score was 3.50 ± 0.50;The SNR was 25.46 ± 6.34 at the delay time of 15 minutes,the CNR was 9.83 ± 3.81,and the image score was 3.00±0.00;The SNR was 22.58 ± 6.44 at the delay time of 25 minutes,the CNR was 7.78 ± 3.11,and the image score was 2.50±0.50;The SNR was 17.92 ± 6.89 at the delay time of 35 minutes,the CNR was 6.43 ± 3.92,and the image score was 1.50±0.50(p < 0.05).There was statistical difference among them.SNR with a delay time of 10 min and 5min(p = 0.150 > 0.05)was compared between the two groups,with no statistical significance.CNR with delay time of 0min and 5min(p =0.681 > 0.05)was compared between the two groups,without statistical significance.The image score with delay time of 0min and 5min(p = 0.121 > 0.05)was compared between the two groups,without statistical significance.ConclusionsIn the first group,SNR with a delay time of 10 min was the highest,and CNR with a delay time of 0min was the highest.In the second group,SNR and CNR with delay time of5 min were the highest.It is recommended to scan within 10 min after injection of contrast agent,and the image quality is the best.ObjectiveTo investigate the effect of different contrast agents(Gd-BOPTA,Gd-DTPA,Gd-DOTA)on brachial plexus magnetic resonance imaging.Methods60 patients suspected with brachial plexus injury were recruited in this study,and divided into three groups randomly.There were 20 patients in each group.Every patient written consent forms were obtained prior to the scan.The MR system is Siemens MR Skyra 3.0T equipment,with 16-channel head coil combined with 18-channel body coil and 18-channel fix sping coil.The first group was injected with GD-BOPTA;the second group used Gd-DTPA;the third group used Gd-DOTA.The amount of contrast agent was 0.1mmol/kg according to patients’ weight,the injection rate was 1.5ml/s,and 20 ml saline was injected at the same rate with high pressure injector.The 3D sampling perfection with application optimized contrasts using different flip angle evolutions(SPACE)STIR sequence was scaned immediately after the contrast agent and saline were injected totally.All the data were transferred to Siemens work station(Siemens Numaris/4 Syngo MR B17).The SI and SD of MIP images for ROI on both sides of C6 peripheral nerves(ROInerve),in regions outside the anatomy(ROIbackground),and tissue adjacent to the peripheral nerves(ROItissue).then SNR and contrast to noise ratio CNR were caculated.SPSS20.0 software was used for statistical analysis.If the data conformed to the normal distribution,statistical method one-way ANOVA was applied;if the data did not conform to the normal distribution,the non-parametric test Kruskal-Wallis(KW)test was applied,and p < 0.05 was considered to be statistically significant.The result was obtained that the highest SNR and CNR of brachial plexus using which contrast agents.ResultsAll data were analyzed by Kolmogorov-Smirnov test with SPSS statistical analysis software.The SNR of brachial plexus nerves of three different types of contrast agents(p =0.007 < 0.05)and CNR(p = 0.002 <0.05),which showed that the data did not follow the normal distribution.The SNR of brachial plexus nerve with Gd-BOPTA contrast agent was 40.66 ± 25.27,and the CNR was 20.24 ± 15.17;the SNR of brachial plexus nerve with Gd-DTPA contrast agent was 34.65 ± 14.86 and CNR was 16.07 ± 7.50;The brachial plexus nerve with Gd-DOTA contrast media had an SNR of 44.63 ± 30.79 and a CNR of 20.84 ± 15.53.Comparing the brachial plexus SNR in the three groups χ2= 1.877,p = 0.391 > 0.05,there was no statistical difference in the SNR of brachial plexus using the three contrast agents to enhance the 3D SPACE sequence;Comparing the CNR χ2= 1.717,p = 0.424 > 0.05,using the three contrast agents to enhance the 3D SPACE sequence showed no significant difference in CNR of the brachial plexus nerve.ConclusionsFor brachial plexus magnetic resonance images with contrast agents,there were no significant differences in the efficacy of brachial plexus enhancement using the three contrast agents of Gd-BOPTA,Gd-DTPA,Gd-DOTA.ObjectiveThe comparative study of the effects of single and half-dose of the magnetic resonance contrast agent Gd-BOPTA on brachial plexus magnetic resonance imaging.MethodsA total of 39 patients with brachial plexus(BP)MR imaging in our hospital were collected.The MR system is Siemens MR Skyra 3.0T equipment,which uses a 16-channel head coil combined with an 18-channel abdominal coil and an 18-channel fix sping coil.Each patient signs a contrast agent-enhanced informed consent form.39 patients were randomly divided into two groups,20 in the first group and 19 in the second group.The first group used the contrast agent Gd-BOPTA at a dose of 0.1mmol / kg,the second group used the contrast agent Gd-BOPTA at a dose of 0.05 mmol / kg,the injection rate was 1.5ml / s,and the same rate was injected 20 ml Saline.Using high-pressure syringe to inject the contrast medium and saline,and immediately the 3D SPACE STIR sequence was started to scan immediately.All the data was transferred to a Siemens workstation(Siemens Numaris / 4 Syngo MR B17).Three-dimensional image reconstruction of brachial plexus nerves was performed with MIP.The SI and SD of MIP images reconstructed were calculated for ROI on both sides of C6 peripheral nerves(ROInerve),in regions outside the anatomy(ROIbackground),and tissue adjacent to the peripheral nerves(ROItissue).then SNR and CNR were caculated.The images were then scored by two senior radiologists.Statistical analysis was performed using SPSS20.0 software.Paired t-test was used to compare the SNR and CNR of the brachial plexus nerves before and after tthe half-dose of the injection of the contrast agent Gd-BOPTA.The independent sample t-test was used to compare and analyze the SNR,CNR between the two groups after single-and half-dose Gd-BOPTA.The Wilcoxon signed rank test of non-parametric test paired sample comparison was used to compare the image quality scores of the them and p < 0.05 was considered statistically significant.ResultsThe SNR of BP nerve before injecting with contrast was 20.723±9.808,and the CNR was 6.626±4.498;The SNR of the BP nerve after injection of the half-dose of Gd-BOPTA was 35.106±12.264 and CNR was 15.844±6.634;The result of paired t test was p <0.05,then the difference is statistically significant.The SNR of BP nerve with half-dose Gd-BOPTA was 35.106±12.264 and CNR was 15.844±6.634;The SNR of BP nerve with a single dose of Gd-BOPTA was 40.665 ± 25.270,and the CNR was 20.244 ± 15.173.The result of independent sample t test was p > 0.05,the difference between them was not statistically significant.The score of BP image without injection of contrast agent was 1.50±1.00,and the score of BP image with half-dose Gd-BOPTA was 3.50±0.75.The result of Wilcoxon signed rank test for nonparametric test paired sample comparison was p < 0.05,and the difference was statistically significant;The score of the BP image with a half-dose of Gd-BOPTA was 3.50±0.75,and the score of the BP with a single-dose Gd-BOPTA was 3.50 ± 0.00,Nonparametric test of two independent samples(Mann-Whitney)was p > 0.05,there is no significant difference between them.ConclusionsThe BP MR imaging can meet the needs of clinical using of half-dose of Gd-BOPTA.In the future work,half-dose of Gd-BOPTA can be used for BP MR imaging. |
PDF Full Text Request