| Research backgroundIn China,the number of new cancers and cancer deaths of lung cancer rank first,and brain metastasis is one of the most common distant metastases.In the existing magnetic resonance examination methods,due to the lack of scanning layer thickness and T1 weighted image,it is necessary to add magnetic sensitivity weighted imaging(SWI)as a supplementary sequence to improve the detection rate of metastasis.However,in the process of detecting micro brain metastases from lung cancer complicated with bleeding,due to the sensitivity of SWI sequence to blood products,it is easy to confuse the metastases with the microbleeds caused by hypertension and other reasons.Therefore,the contrast-enhanced magnetic sensitivity weighted imaging(CE-SWI)sequence with unique T1-weighted characteristics,as the experimental sequence of this study,provides a new examination method and idea for the detection of lung cancer brain metastases.ObjectiveBy comparing with the gold standard contrast-enhanced T1 weighted imaging(CE-T1WI),this paper discusses the value of CE-SWI sequence in the detection of brain metastases from lung cancer,in order to provide a more efficient detection method for the clinical diagnosis of lung cancer brain metastasis.Methods1.Fifty cases of brain metastases from lung cancer were enrolled.The numbers of brain metastases and the group of lesions with a maximum diameter of smaller than 3mm were detected by CE-T1WI,SWI and CE-SWI.Chi square test was used to analyze the difference among the three sequences,to evaluate the sensitivity of CE-SWI in the detection of brain metastases from lung cancer.The two doctors scored the image quality of CE-T1WI,SWI and CE-SWI respectively,and difference of scores was analyzed by Mann Whitney U test.2.There were Fifty cases of microbleeds.The numbers of patients with hypertension in the control group and the number of microbleeds detected were recorded.The maximum diameter of the focus was measured.Chi square test analysis and logistic regression analysis were used to study the statistical difference and correlation of microbleeds detected by CE-SWI sequence in brain metastasis from lung cancer and hypertension.Results1.A total of 144 lesions were detected by CE-T1WI,SWI and CE-SWI,of which the detection rate of CE-T1WI was 80%,that of SWI was 77%and that of CE-SWI was 88%.There was significant difference among the three groups by Chi square test(P<0.05).A total of 37 lesions with a maximum diameter of smaller than 3mm were detected by stratified analysis,of which the detection rate of CE-T1WI was 57%,SWI was 73%,and CE-SWI was 84%.There was significant difference among them by Chi square test(P<0.05).There was no significant difference in the quality scores of CE-T1 WI,SWI and CE-SWI between the two doctors(P>0.05).2.Logistic regression analysis showed that there was significant difference between the number of cases with low signal detected by CE-SWI and the number of patients with brain metastases and hypertension(P<0.05).Brain metastases from lung cancer and hypertension are the risk factors of low signal detection by CE-SWI.When CE-SWI sequence is used to detect lung cancer brain metastasis,the probability of low signal detection by CE-SWI is greater.ConclusionThe CE-SWI sequence with T1 penetration effect has more advantages than the gold standard CE-T1WI in the detection of metastatic lesions from lung cancer<3mm,and can clearly show the enhancement area,bleeding area and peritumoral edema of the tumor,which is not easy to be confused with the microbleeds caused by hypertension.CE-SWI sequence can increase the diagnostic confidence of radiologists and is an additional useful tool for routine MRI sequences on brain metastases screening. |
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