Multiparameter MR Imaging About The Morphology, Hemodynamics And Perfusion Of The Vertebrobasilar Artery

PartⅠ:Anatomical study of posterior circulation in vivoObjective: To observe and measure the posterior circulation in vivo by 3.0T magnetic resonance angiography (MRA).Methods:A total of 108 subjects experienced MRA and conventional MR examination, the sex ratio was 58 male to 50 female, and the age ranged from 4 to 63 years (mean 39.86±14.57 years). Observing indexes included the intracranial vertebrobasilar artery morphological type; the thickness of bilateral posterior cerebral artery and posterior communicating artery; the location, number, degree and signal of bilateral superior cerebellar artery and anterior inferior cerebellar artery; measuring the length and lumen diameter of the basilar artery; the indication of anterior inferior cerebellar artery in source image and maximum intensity projection (MIP) recombinant image; the appearance and signal of the vertebral artery. Statistical testing was performed.Results: The common types of basilar artery were TypeⅠⅠ, TypeⅡRⅢ, TypeⅡRⅠor TypeⅡLⅠrespectively. Most of the P1 segments were thicker and some P1 segments were also undeveloping. Most of the posterior communicating artery was undeveloping, and others were thicker or slightly thinner. There was relationship between the diameter of P1 segment of the posterior cerebral artery and posterior communicating artery (PCoA) (right: correlation coefficient rk=0.44,P<0.01; left: correlation coefficient rk=0.50, P<0.01). The overwhelming majority of superior cerebellar artery arose from basilar artery, and the signal were strong, the number was 1 or 2. There was no difference between the degree of the bilateral superior cerebellar artery and basilar artery in statistics (t=-1.19, P=0.23>0.05). About 3/4 of the anterior inferior cerebellar artery was developing. Most of the signals were strong, but a few were weak, and the number was 1 or 2. There was no difference between the degree of the bilateral anterior inferior cerebellar artery and basilar artery (t=-1.13, P=0.26>0.05). The average straight line length of the basilar artery was (2.35±0.30) cm, The straight line length of the basilar artery in men was longer than that in women (t=4.19, P<0.0001). Straight line length of the basilar artery was correlated with age (r=0.28, P=0.0038<0.05). The straight line length of the basilar artery in subjects whose bilateral PCoA was undeveloped was longer than that in those unilateral or bilateral PCoA developed (t=2.96, P=0.004<0.05). The number of the bending basilar artery was 51. Apart from 1 case of bilateral bending, the others were unilateral. The average diameter of the basilar artery was (0.26±0.05) cm. there was no difference between the diameter of upper, middle and lower segment of basilar artery (χ2=3.13, P=0.21>0.05). The average diameter of the basilar artery in men was wider than that of the women (t=3.03, P=0.003<0.05). The average diameter of the basilar artery in subjects whose bilateral PCoA undeveloped was wider than that in those unilateral or bilateral PCoA developed (t=4.09, P<0.01). The number of the right vertebral artery dominance, left vertebral artery dominance and equivalent-sized vertebral artery were 16, 33 and 59 respectively.Conclusions: MRA can be used to measure and research the normal anatomy and variation of the posterior circulation non-invasive in vivo, so as to obtain the the type maps of basilar artery and related parameters, and provide important information for the study of anatomy, medical imaging and surgery.PartⅡ: Measurement of the velocity of steady fluid flow phantom by using 3.0 T MR Fast CINE PC sequenceObjective: To verify the accuracy of the hemodynamics measurement by 3.0 T MR Fast CINE PC sequence through establishing a steady fluid flow phantom,and to optimize the imaging parameter.Methods: A plastic tube whose diameter was 3.0 mm and was filled with liquid was fixed in a water phantom. One terminal of the tube was connected to the high pressure injector for injecting physiological saline with different velocity, another terminal was inserted into a volumetrical cylinder for recovering saline water. The phantom was placed in the center of a 8-channel array head coil. And the tube was parallelly placed with the major axis of magnet. By using Fast CINE PC sequence for scanning by 3.0T high field MR scanner, scanning plane was perpendicular to the major axis of tube. The velocity at different velocity encoding (VENC), different direction of velocity encoding, different velocity, different direction of flow, different angle, different region of interest (ROI), different slice, and different point in the lumens was measured. After image postprocessing, the velocity of 30 phase during a cardiac cycle was measured, and the average velocity was taken as velocity for research. Statistical tesing was performed.Results: Whatever the direction of velocity encoding was, phase-contrast image could display the flow direction of liquid correctly, and there was no difference between the measured velocity and actual velocity at different direction of velocity encoding ( t=0.29, P=0.79>0.05 ). Aliasing artifacts would appear when VENC was less than the actual velocity. With the increasing of VENC, aliasing artifacts reduced gradually up to disappear, and there was no difference between the measured velocity and VENC ( P=0.94>0.05 ). The measured velocity was positive correlated with actual velocity (correlation coefficient =0.99, P<0.0001). There was no difference between the measured velocity and actual velocity whether the flow direction of liquid was identical or opposite with VENC ( F=3.51,P=0.0581>0.05 ). There was no difference between the measured velocity and actual velocity no matter how degree the tube was ( t=2.01, P=0.09>0.05 ). The measured velocity at different ROI was negative correlated with the area of ROI, correlation coefficient was -0.99 ( P<0.0001 ). The measured flow volume at different ROI was positive correlated with the area of ROI, and the correlation coefficient was 0.98 ( P<0.0001 ). There was no difference between the measured velocity at different slice and actual velocity (t=-0.97 ,P=0.36>0.05). Conclusions: 3.0T Fast Cine PC is more accurate in the determination of velocity of the steady fluid flow phantom, and provides reliable experimental basis for human hemodynamics measurement. PartⅢ:Hemodynamics quantitative analysis and related quantitive index of the basilar artery in ChineseObjective: To measure the hemodynamics of basilar artery in Chinese people by Fast CINE PC MR and FAIR sequence, and to obtain the normal parameter for clinic.Methods: A total of 50 healthy volunteers experienced MRI, MRA, Fast CINE PC and FAIR examination, the sex ratio was 25 male to 25 female, and the age ranged from 23 to 69 years. The images were observed by Signa Excite HD 3.0T high field MR scanner (GE Medical System, U.S.A) with a 8-channel array head coil. The velocity and the blood flow volume of basilar artery at three different levels was measured and calculated. The FAIR value of bilateral occipital lobe, cerebellum, pons and medulla oblongata was measured. Statistical tesing was performed.Results: There was no difference in velocity between upper plane and middle plane, but they were different with the velocity of the lower plane (P<0.05). There was difference in average velocity of basilar artery between 20~ age groups and 40~, 60~age groups (P<0.05). There was no difference in peak velocity and blood flow volume between different ages (P>0.05). All of the peak velocity of basilar artery appeared in systole period. The velocity in the systole period was higher than the threshold period. There was no difference in FAIR value between bilateral occipital lobe, cerebellum, pons and medulla oblongata (P>0.05). The blood flow volume of basilar artery was positive correlated with the FAIR value of posterior circulation (rk=0.23,P=0.0183<0.05)Conclusions: Application of Fast CINE PC MR and FAIR can measure the hemodynamics of the basilar artery and its blood-supply area, and provide evidence for detecting diseases. The blood flow volume of basilar artery is positive correlated with the FAIR value of posterior circulation. PartⅣ: Hemodynamics quantitative analysis of the basilar artery diseaseExperiment 1:Hemodynamics quantitative analysis of the tortuous basilar arteryObjective: To investigate the hemodynamics of basilar artery and its blood-supply area when there is basilar artery tortuosity.Methods: Thirty-six consecutive patients (26 male, 10 female) with tortuous basilar artery, who were diagnosed by MRA, were selected from the Second Hospital of Hebei Medical University as case group. Thirty six healthy volunteers were selected as control group, there was no significant difference between the two groups in age and sex. All subjects in the case group and in control group were examined by MRI, MRA, Fast CINE PC (middle plane of the basilar artery) and FAIR. The images were observed by Signa Excite HD 3.0T high field MR scanner with a 8-channel array head coil. After image postprocessing, the velocity and the blood flow volume of basilar artery was measured and calculated. The FAIR value of bilateral occipital lobe, cerebellum, pons and medulla oblongata was measured. Statistical tesing was performed.Results: The average velocity, peak velocity and blood flow volume of the basilar artery in the case group were all less than the control group (average velocity: t=-5.55, P<0.0001; peak velocity: t=-5.33, P<0.0001; blood flow volume: t=-2.29, P=0.02<0.05) . There was no difference in FAIR value of bilateral occipital lobe, cerebellum, pons, medulla oblongata and its summation between the case group and control group (P>0.05).Conclusions: The velocity and blood flow volume of the basilar artery on patient with tortuous basilar artery is decreased, but the perfusion of the posterior circulation has no change within a certain extent.Experiment 2: Hemodynamics quantitative analysis of the basilar artery stenosisObjective: To investigate the hemodynamics of basilar artery and its blood-supply area when there is basilar artery stenosis.Methods: Sixteen consecutive patients with basilar artery stenosis and 3 patients with basilar artery occlusion, who were diagnosed by MRA, were selected from the Second Hospital of Hebei Medical University as case group. Sixteen healthy volunteers were selected as control group, there was no significant difference between the two groups in age and sex. All subjects in the case group and in control group were examined by MRI, MRA, Fast CINE PC ( the most stenotic plane of the basilar artery and relatively normal plane beyond stenosis) and FAIR. The images were observed by 3.0T high field MR scanner with a 8-channel array head coil. After image postprocessing, the velocity and the blood flow volume of basilar artery was measured and calculated. The FAIR value of bilateral occipital lobe, cerebellum, pons and medulla oblongata was measured. Statistical tesing was performed.Results: There was difference in the average velocity, peak velocity and blood flow volume of the basilar artery between stenosis plane and the control group, There was difference in the average velocity, peak velocity and blood flow volume of the basilar artery between the relatively normal plane beyond stenosis and the control group, There was no difference in the average velocity, peak velocity and blood flow volume of the basilar artery between the stenosis plane and relatively normal plane beyond stenosis (P<0.05). The total FAIR value of the posterior circulation in the case group was less than the control group (t=-2.24,P=0.03<0.05). The blood flow volume of the basilar artery at stenosis plane was negative correlated with the degree of stenosis, the correlation coefficient was -0.39 (P=0.03<0.05).Conclusions: The velocity and blood flow volume of the basilar artery on patient with basilar artery stenosis is decreased. The blood flow volume of the basilar artery is negative correlated with the degree of stenosis. The perfusion of the posterior circulation is decreased when there is the basilar artery stenosis or occlusion, but it has no relationship with the degree of the stenosis.Experiment 3: Hemodynamics quantitative analysis of the posterior circulation infarctionObjective: To investigate the hemodynamics of basilar artery and its blood-supply area when there is posterior circulation infarction.Methods: Thirty-nine consecutive patients (27 male, 12 female) with posterior circulation infarction, who were diagnosed by MRI, were selected from the Second Hospital of Hebei Medical University as case group. 39 healthy volunteers were selected as control group, there was no significant difference between the two groups in age and sex. All subjects in the case group and in control group were examined by MRI, MRA, Fast CINE PC (middle plane of the basilar artery when there was no stenosis, and the most stenotic plane when there was the basilar artery stenosis) and FAIR. The images were observed by Signa Excite HD 3.0T high field MR scanner with a 8-channel array head coil. After image postprocessing, the velocity and the blood flow volume of basilar artery was measured and calculated. The FAIR value of bilateral occipital lobe, cerebellum, pons and medulla oblongata was measured. Statistical tesing was performed.Results: The average velocity, peak velocity and blood flow volume of the basilar artery in case group were all less than the control group (average velocity:χ2=16.02, P<0.0001; peak velocity:χ2=15.07, P=0.0001<0.05; blood flow volume:χ2=21.09, P<0.0001). The total FAIR value of the posterior circulation was less than the control group (χ2=-2.24, P=0.03<0.05).Conclusions: The velocity and blood flow volume of the basilar artery on patient with posterior circulation infarction are decreased. The perfusion of the posterior circulation is decreased when there is posterior circulation infarction.Experiment 4: Hemodynamics quantitative analysis of the patients with vertigoObjective: To investigate the hemodynamics of basilar artery and its blood-supply area in patients with vertigo.Methods: Fifty consecutive patients (35 male, 15 female) with vertigo were selected from the Second Hospital of Hebei Medical University as case group. Fifty healthy volunteers were selected as control group, there was no significant difference between the two groups in age and sex. All subjects in the case group and in control group were examined by MRI, MRA, Fast CINE PC (middle plane of the basilar artery) and FAIR. The images were observed by Signa Excite HD 3.0T high field MR scanner with a 8-channel array head coil. After image postprocessing, the velocity and the blood flow volume of basilar artery was measured and calculated. The FAIR value of bilateral occipital lobe, cerebellum, pons and medulla oblongata was measured. Statistical tesing was performed.Results: The average velocity, peak velocity and blood flow volume of the basilar artery in case group were all less than the control group (average velocity: t=-5.79, P<0.0001; peak velocity: t=-5.71, P<0.0001; blood flow volume: t =-4.92, P<0.0001) . The average velocity, peak velocity and blood flow volume of the basilar artery in case group whose brain parenchyma and blood vessels were normal were less than the control group (average velocity: t=-2.72, P=0.0086<0.05; peak velocity: t =-3.12, P=0.0027<0.05; blood flow volume: t =-3.53,P=0.0008<0.05) . There was no difference in perfusion of the posterior circulation between the case group and control group (χ2=0.76,P=0.38>0.05).Conclusions: Whether the brain parenchyma and blood vessels is normal or not, the velocity and blood flow volume of the basilar artery in patients with vertigo are decreased. There is no change in the perfusion of the patients with vertigo. PartⅤ: High resolution wall and lumen imaging of the basilar artery by using multiparameter Magnetic ResonanceExperiment 1:High resolution wall and lumen imaging of the basilar artery by using multiparameter Magnetic Resonance in Chinese Objective: To measure the lumen and wall of basilar artery by using DIR in Chinese, and to obtain the normal parameter for clinic.Methods: A total of 50 subjects experienced MRI, MRA and DIR examination, the sex ratio was 25 male to 25 female. The images were observed by Signa Excite HD 3.0T high field MR scanner (GE Medical System, U.S.A) with a 8-channel array head coil. The wall thickness and the lumen diameter of the basilar artery were measured, and the total vessel area (TVA), lumen area (LA), wall area(WA), normalized wall index(NWI) were calculated. After measuring the lumen diameter of the basilar artery in MRA positive projection at the plane corresponding to DIR, statistical tesing was performed.Results: There was no difference in the wall thickness and the lumen parameter of the basilar artery between different ages(P>0.05). There was no difference in the lumen diameter measure value of the basilar artery between MRA and DIR (t=-0.48, P=0.63>0.05).Conclusions: In vivo high spatial resolution DIR provides a unique new method for noninvasively imaging, assessing and measuring the morphological features of human basilar artery. There is a better concordance in the lumen diameter measure value of the basilar artery between MRA and DIR.Experiment 2: High resolution wall and lumen imaging of the basilar artery by using multiparameter Magnetic Resonance in basilar artery diseaseObjective: To determine the diagnostic accuracy of DIR in basilar artery stenosis and occlusion so as to forecasting the development of arteriosclerosis.Methods: Nine consecutive patients with basilar artery tenuity and 17 patients with basilar artery stenosis or occlusion, who were diagnosed by MRA, were selected from the Second Hospital of Hebei Medical University as case group. Twenty healthy volunteers were selected as control group. All subjects in the case group and in control group were examined by MRI, MRA and DIR. The images were observed by Signa Excite HD 3.0T high field MR scanner with a 8-channel array head coil. The plaque signal intensity was interpreted and the wall thickness and the lumen diameter of the basilar artery were measured at the most stenotic segment. Statistical tesing was performed.Results: Anterior wall thickness of basilar artery: There was no difference between tenuity group, stenosis group, and control group (χ2=6.02, P=0.0493). Posterior, left and right wall thickness of basilar artery: There was no difference between tenuity group and control group, but there was difference between tenuity group and stenosis group, stenosis group and control group ( Posterior wall:χ2=17.42, P=0.0002<0.05; left wall:χ2=10.46, P=0.0054 <0.05; right wall:χ2=15.67, P=0.0004<0.05). The diameter from left to right: There was difference among tenuity group, stenosis group, and control group (χ2=21.17, P<0.0001). Total vessel area (TVA): There was difference between tenuity group and control group, tenuity group and stenosis group, but there was no difference between stenosis group and control group (χ2=10.99, P=0.0041<0.05). Lumen area (LA): There was difference among tenuity group, stenosis group, and control group (χ2=21.17, P<0.0001). Wall area (WA): There was no difference between tenuity group and control group, but there was difference between tenuity group and stenosis group, stenosis group and control group (χ2=16.04, P=0.0003<0.05). Normalized wall index (NWI): There was no difference between tenuity group and stenosis group, but there was difference between tenuity group and control group, stenosis group and control group (F=17.02, P<0.0001).Conclusions: The Wall area(WA) and Normalized wall index(NWI) can be used as the index for evaluating the burden of arteriosclerosis plaque. Only the lumen diameter can not decide lumen stenosis.