Clinical Application Of Magnetic Resonance Double Inversion Recovery Sequence In Multifocal Lesions Of Brain

ObjectiveTo investigate the clinical application value of MR double inversion recovery（DIR）sequence in multiple brain ischemic lesions,multiple sclerosis and brain metastasis.Materials and methodsThe MR appearances of 20 cases with brain metastasis confirmed by clinical pathol ogy of lung cancer,20 cases with multiple brain ischemic lesions and 20 cases with MS confirmed by follow-up were retrospectively analyzed.All patients were performed by the routine cerebral MRI and sagittal 3D DIR.And brain metast-asis patients were performed by the contrast enhanced T₁WI after the above scan.For brain metastasis patients,the number of brain metastasis on T₂FLAIR and DIR were evaluated based on the contrast enhanced T₁WI.For multiple brain ischemic lesions and multiple sclerosis patients,the mean CNR and CR of lesions were calculated.The results were statistically analyzed using SPSS 20.0 software.And the statistical difference of lesions number,CNR and CR were estimated.ResultsBrain metastases lesions were characterized by low signal accompanied by flake long T1 long T2 signals on DIR images,tumors and surrounding edema have clear boundary.The numbers of brain metastasis on T₁WI+C,T₂FLAIR and DIR sequences were 120,61and 94,respectively,And the difference in the detection rate of brain metastasis between T₂FLAIR and DIR was statistically significant（P<0.001）.Multiple brain ischemic lesions can be characterized by obvious high signal on the DIR images.The mean CNR and CR of lesion which showing the high signals on T₂FLAIR and DIR at the same time were33.98±12.31,24.88±9.54 and 1.32±0.52,0.48±0.14,respectively.And the different ces between T₂FLAIR and DIR were statistically significant（P<0.05;P<0.001）.MS lesions were often characterized by white spots,flake or irregular high signal on the DIR.The mean CNR and CR of lesion were 36.17±11.89,29.16±8.59 and 2.37±0.86,0.66±0.19,respectively.And the differences were statistically significant（P<0.05;P<0.001）.Conclusion3D DIR imaging technology could clearly display lesions comparing with conv enti onal T₂FLAIR sequence.Lesions’CNR and CR were higher.And more brain metast ases were discovered without the contrast agent.