A Comparative Study Of 3.0T Magnetic Resonance ZTE-MRA And TOF-MRA In Diagnosis Of Intracranial Aneurysms

Objective: A study comparing MRA examination of patients with clinically suspected intracranial aneurysm and postoperative patients with aneurysm,including ZTE-MRA examination and TOF-MRA examination with DSA angiography results.The value of diagnosis and details in diagnosis of intracranial aneurysms(including the angle between the aneurysm and the tumor-bearing blood vessel,the size of the aneurysm,the size of the tumor neck,the growth direction and the analysis of the components in the tumor cavity,etc.)and the display clarity of hemangioma,surrounding blood vessel and the presence of residual tumor cavity after surgery were comprehensive evaluated between ZTE-MRA and TOF-MRA in order to study the difference in image quality between the two MRI methods and the difference in diagnostic value and detailed information display of intracranial aneurysms.Materials and Methods: Eighteen patients who were diagnosed intracranial aneurysms in our hospital's department of neurology and neurosurgery from October 2019 to January 2020 were selected,including 8 female patients and 10 male patients,aged 55 to 82 years,with an average age 68.5 ± 13.5 years old,and fifteen intracranial aneurysms have been operated.The clinical symptoms included blurred vision,headache,dizziness,numbness of the limbs,etc.If there were two or more aneurysms in the same patient,they were separately included as lesions and included in the group.ZTE-MRA and TOF-MRA inspection were performed at the same time while DSA inspection is performed within one week of MRA inspection.GE Medical Systems' Discovery MR750 W 3.0T magnetic resonance scanner was used to perform ZTE-MRA and TOF-MRA scans on patients.A Philips DSA contrast machine was used for DSA angiography.GE's AW4.6 software was used for postprocessing of images which used maximum intensity projection(MIP).The original images obtained from the ZTE-MRA and TOF-MRA were used to reconstruct the blood vessels to obtain the MRA maps of the two examination methods.Two attending radiologists and two neurosurgeons at the post-processing workstation reviewed the images for giving subjective and objective evaluation of image quality,and qualitative diagnosis and detailed diagnosis of intracranial aneurysms.If there is a difference in subjective evaluation opinions,consultation is determined for a common view.The qualitative diagnosis and detailed diagnosis are evaluated for each case which based on image quality and intracranial aneurysm,including the angle between the aneurysm and the tumor-bearing blood vessel,the volume of the aneurysm,the growth direction,the size of the tumor neck and the analysis of the intracranial components.The detailed diagnosis of the aneurysm needs to be performed from the same reconstruction angle of ZTE-MRA and TOF-MRA for comparison.Finally,the results of all diagnostic analysis and statistical data were calculated by SPSS 21.0.Results: 1.Image quality evaluation A total of 18 patients were collected in this project,with 15 diagnosed patients,with 25 suspected aneurysms and 22 diagnosed aneurysms.10 patients with single aneurysms,4 patients with 2 aneurysms,and 1 patient with 4 aneurysms.The image quality of 18 collected patients: among the image quality of ZTE-MRA,there were 15 with excellent scores,2 with good scores,and 1 with poor scores,and the excellent image quality score accounted for 83.3%;Among the image quality of TOF-MRA,there were 12 with excellent scores,4 with good scores,and 2 with poor scores.The image quality score was 66.7%.The independent samples of the rank sum test between ZTE-MRA and TOF-MRA was performed.There was no statistically significant difference in the image quality between ZTE-MRA and TOF-MRA(p = 0.867).The average of the signal-tonoise ratio(SNR)of the two magnetic resonance examination methods was 14.2 and 19.4,respectively.There was no significant statistical difference in SNR values between the two magnetic resonance examination methods(p = 0.175).2.Evaluation of intracranial aneurysms The results of the qualitative diagnosis of intracranial aneurysms is based on whether an aneurysm was diagnosed,the sensitivity of the ZTE-MRA for the diagnosis of intracranial aneurysms was 100% and the specificity was 66.7%.The Kappa value is 0.779,and there is a good agreement between ZTE and DSA.TOF-MRA had a sensitivity of 81.8% and a specificity of 33.3% in the diagnosis of intracranial aneurysms.Comparing the consistency with the DSA results,the Kappa value is 0.118,there is a certain consistency between TOF and DSA.Comparing the Kappa values between ZTEMRA,TOF-MRA and DSA results,the qualitative diagnosis of intracranial aneurysms by ZTE-MRA is more accurate than TOF-MRA.The detailed diagnosis of intracranial aneurysms was divided into three groups and the chi-square test was performed with the results of DSA,and they were divided into three groups with high consistency,moderate consistency and low consistency.For ZTEMRA,there were 12 high consistency diagnosis of aneurysms with DSA.The accuracy rate is 54.5%,and there were 8 moderately consistent diagnosis with DSA results,the accuracy rate is 36.4%,while there were 2 low consistency diagnosis with DSA result,and the accuracy rate is 9.1%.For TOF-MRA,there were 8 high consistency diagnosis of aneurysms with DSA.The accuracy rate is 44.4%,and there were 6 moderately consistent diagnostic with DSA results,the accuracy rate is 33.3%,while there were 4 low consistency diagnosis with DSA result,and the accuracy rate is 22.2%.There was no statistically significant difference between the two methods in the diagnosis of intracranial aneurysms(p = 0.50> 0.05).DSA showed 6 thrombi in the aneurysm cavity.ZTE-MRA showed 6 thrombi in the aneurysm cavity,with an accuracy of 100%,a sensitivity of 100%,and a specificity of 100%.TOF-MRA showed 10 thrombi in the aneurysm cavity,of which 6 were positive for DSA and 4 were negative,with an accuracy of 77.8%,a sensitivity of 100%,and a specificity of 66.7%.There was a statistically significant difference between ZTE-MRA test and TOF-MRA(P = 0.018).Among the 18 patients included in this study,with 15 diagnosed patients,22 were diagnosed with intracranial aneurysms,of which 15 were treated with interventional embolization.DSA showed 3 aneurysm remnants after embolization.ZTE-MRA showed 2 aneurysm remnants after embolization,with an accuracy of 66.7% while TOF-MRA showed 0 aneurysm remnants after embolization.There was a statistically significant difference between the two magnetic resonance examination methods(P = 0.007).Conclusions: 1.There is no difference in the image quality of intracranial aneurysms between TOFMRA and ZTE-MRA.2.The qualitative diagnosis of intracranial aneurysms by ZTE-MRA is more accurate than that of TOF-MRA.3.ZTE-MRA is superior to TOF-MRA in judging whether intracranial aneurysms are associated with arteriothrombotic thrombosis,and there is no significant statistical difference between the two in the details of the rest of the aneurysm diagnosis.4.In determining whether there is an aneurysm residual cavity and aneurysm tumorbearing blood vessels(unobstructed)after aneurysm embolization,ZTE-MRA is better than TOF-MRA,and there is a statistical difference between the two.