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Objective We performed a diffusion tensor imaging (DTI) study to explore the value of mode of anisotropy (MO) and other DTI-derived indices in assessing white matter fiber damage with mild to moderate Alzheimer disease (AD) patients. Methods This study was a prospective study. From February 2015 to February 2018, 33 patients with mild to moderate AD according to criteria were prospectively recruited as AD group at the First Affiliated Hospital of Wenzhou Medical University. Twenty healthy age-, sex-matched volunteers were recruited as normoal conctrast (NC) group. All subjects were performed by conventional brain MRI and DTI scans. The MO, anisotropic fraction (FA), mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AxD) of white matter fibers were obtained from DTI images after TBSS post-processing. The statistical analyses of DTI indices between AD group and NC group were carried out in Functional MRI Software Library software. Results As compared with NC group, we found 1 cluster with significant decrease FA and increase RD in AD group, the affected fibers involving bilateral anterior thalamic radiation, corticospinal tract, cingulate gyrus, hippocampus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, uncinated fasciculus, superior longitudinal fasciculus (P<0.05). The MD value increase(P<0.1) was found to coincide with the decrease of FA and the increase of RD, while no significant increase or decrease in P<0.05. Three clusters of MO increases (P<0.05) accompanying with increases of AxD were found in left anterior limb of internal capsule, bilateral posterior limb of internal capsule, posterior forceps, left centrum semiovale and parietal lobe. Two clusters of MO decreases (P<0.05) accompanying with decreases of FA and increases of RD were found in fornix, forceps, external capsule, centrum semiovale and left frontal lobe. Conclusions The combination of MO with DTI routine tensor indices (FA, RD, MD, AxD) can further reveal the microstructural damage of white matter fibers in AD, especially to crossing-fibers. The abnormalities of MO combined with FA, RD and MD reveal the degeneration of both bundles of crossing-fibers,and the abnormalities of MO combined with AxD reveal that the white matter damage was mainly caused by axon damage of one bundle of cross fibers.
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Objective To evaluate the clinical value of enhanced 3D-SPACE-STIR sequence MR in brachial plexus injury post-ganglionic nerve.Methods Eighteen patients with suspected brachial plexus injury were examined by routine MRI,3D-SPACE-STIR sequence and enhanced scan.The position,morphology,signal intensity of the brachial plexus injury and its relation with the proximal and distal portions of the brachial plexus were evaluated by senior radiologists.The image quality of plain and enhanced 3D-SPACE-STIR was evaluated respectively.Results The CNR of plain scan and enhanced 3D-SPACE-STIR sequence images were 32.31+2.98 and 43.66+2.78 respectively and the difference was statistically significant.Plain and enhanced 3D-SPACE-STIR sequences of supraclavicular nerves display rate were 95.0% and 96.1% respectively without having statistically significant difference.However,the subclavicular segment of the brachial plexus showed the displaying rates of 66.7% and 94.4% and the difference was statistically significant.Moreover, the background suppression effect of enhanced scan was better than that of the plain scan.Conclusion Enhanced 3D-SPACE-STIR sequence can clearly show brachial plexus injury,and its image quality is better than that of the plain scan,which can provide important imaging basis for accurate diagnosis of brachial plexus injury.
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Objective To discuss the influence of the change in ceiling-mounted shield positions on the radiation doses to the first and second operators during percutaneous coronary intervention.Methods In this study,the entrance surface dose (ESD) rates were measured for the first and second operators at 125 cm and 155 cm height on different ceiling-mounted shield positions separately through transradial approach.Measurements were repeated 20 times for each position and T test was used for statistical analysis of dose rate arithmetic mean values.Results For the first operator,the effective dose values were obtained only on left foot position.The ESD rate values at ceiling-mounted shield position close to patient were higher than that close to operators (t125 =46.9,t155 =4.1,P ＜0.05).For the second operator,the ESD rate values on his foot position,right foot position,left anterior oblique position and right anterior oblique position at ceiling-mounted shield position close to the operator,were higher than that close to the patient separately (t125 =11.9,24.4,11.2,2.7,t155 =16.1,2.8,14.4,28.8,P ＜ 0.05).The ESD rate values on head position,left foot position,left head position at ceiling-mounted shield position close to the operator,were lower than that close to the patient (t125 =-4.3,-2.4,-80.4,t155 =-10.2,-6.7,-152.6,P ＜ 0.05).Conclusions The change in the ceiling-mounted shield positions gave rise to change in radiation dose to the operators.The changes in radiation doses caused by the changes in ceiling-mounted shield positions are different in various angiographic positions.Ceiling-mounted shield should be used in a reasonable way in agreement with different positions in percutaneous coronary intervention so as to effectively reduce operators radiation dose.
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Objective To explore the role ofmirror image on arterial lesion severity of acute ST segment elevation myocardial infarction (STEMI) patients with electrocardiograrn(ECG) reciprocal lead ST segment,as well as its clinical prognosis.Methods Totally 167 STEMI patients with completed data were enrolled in present study.The patients were divided into four groups according to the amplitude of corresponding lead ST segment.Group Ⅰ consisted of 33 patients with non ST depression and group Ⅱ consisted of 97 patients whose amplitude of corresponding lead ST segment were less or equal to the amplitude of the ST segment elevation in myocardial infarction area.Group Ⅲ consisted of 25 patients whose amplitude of corresponding lead ST segment was larger than the amplitude of the ST segment elevation and group Ⅳconsisted of 12 patients whose corresponding ST segment and ST segment in myocardial infarction area were all elevated.The culprit artery lesion and clinical prognosis were compared between the four groups.Results There were significant differences in terms of the extent of lesion stenosis and the number of coronary artery stenosis among the four groups (x2 =13.49,P＜0.05;x2=78.34,P＜0.01).In Ⅳ group,the prognosis indices included pump failure,low blood pressure,malignant arrhythmia,ventricular wall incoordination,left ventricular ejection fraction ≤ 50％ and inhospital mortality significantly increased(P＜0.01).Conclusion Different corresponding ST segment depression in patients with acute ST segment elevation myocardial infarction can forecast the culprit artery lesion and clinical prognosis.
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Objective To study the effects of two different methods of high-pressure injections on imaging quality of synchronous left axillary artery and vein by using volume CT.Methods Forty seven patients who underwent left axillary vein and artery CTA examination study were analyzed retrospectively according to the contrast agent injection scheme and was divided into two groups A and B.Group A of 25 patients used protocol A,adopted clinical routine delay scanning method,via right elbow vein inject contrast medium.Group B of 22 patients used protocol B,adopted artery delayed imaging combined with vein direct imaging method,via right elbow vein,left radial vein inject contrast agent,respectively.Both values of CT and contrast to noise ratio (CNR) of two groups were compared,objective image quality was compared by two blinded readers.Mann Whiteny U test was used.Results The median of CT values for left axillary artery in group A was 151.9 HU.The median of CNR values for left axillary artery in group A was 7.4.The median of CT values for left axillary vein in group A was 116.0 HU.The median of CNR values for left axillary vein in group A was 3.83.The median of CT values for left axillary artery in group B was 348.8 HU.The median of CNR values for left axillary artery in group B was 25.3.The median of CT values for left axillary vein in group B was 497.0 HU.The median of CNR values for left axillary vein in group B was 35.4.Both values of CT and CNR in two groups showed significant difference (Z=-5.735,-5.799,-5.863 and-5.863,P＜0.01).All of the median scores in group B were greater than in group A(P＜0.01).Conclusion The enhancement effect of protocol B in the left axillary arteriovenous synchronous imaging is significantly higher than those of protocol A,and demonstrates clear image quality and clearer anatomic relationship.
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Objective To investigate MRI signal features and MRI appearances of patients with advanced stage in polyacrylamide hydrophilic gel injection for facial plasty.Methods In this study,MRI of 11 cases with 23 polyacrylamide hydrophilic gel injection of facial plasty for 6 to 10 years were retrospectively reviewed.All images were acquired with GE 3.0T MR imaging unit.MR sequences,including FSE T1WI,FSE FS T2WI,and STIR were applied with 8-channel brain coil.MRIs sliced through the maxillofacial region in the transverse,coronal and sagittal planes.Results In 11 cases of 23 polyacrylamide hydrophilic gel injection,there were different degrees of capsule rupture and induration in 6 polyacrylamide hydrophilic gel injection,and the images showed sporadic callosities such as subcutaneous nodules and nodules in glands or muscles ; hydrogel migration in 8 polyacrylamide hydrophilic gel injection.Secondary deformity occured in 80 ％ cases,in which the most cases were induced by hydrogel migration.Conclusions Magnetic resonance imaging can make clear of the type of rupture and the distribution leakage of polyacrylamide hydrophilic gel for facial plasty and it is an ideal approach for advanced patients with polyacrylamide hydrophilic gel injection for follow-up.
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Objective To evaluate the imaging features of patients with vascular cognitive impairment (VCI) induced by Subcortical Ischemic Vascular Disease (SIVD), through magnetic resonance diffusion tensor imaging ( DTI ) and proton spectroscopy ( MRS ) technology. Methods A total of 52 patients with SIVD were enrolled. After analysis of scale score, 32 patients with cognitive impairment were assigned to VCI group and 20 patients with no cognitive impairment were assigned to control group. Both group received DTI and MRS examination. The mean values of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the bilateral temporal, frontal, parietal and occipital white matter regions as well as in the bilateral centrum semiovale were calculated. The peak value of MRS of N-acetyl aspartate (NAA) , choline ( Cho), creatine (Cr) and phaseomannite ( mI ) were calculated. Results Compared with control group, FA decreased in the region of temporal, frontal, parietal as well as in the centrum semiovale , and ADC increased in VC[group ( P ＜ 0.05 ) . In the frontal regions and centrum semiovale,the VCI patients had a significant FA decrease. The ADC value increased obviously in the temperal lobe.Spectrum analysis results showed, NAA/Cr was lower than control group in VCI group in the frontal lobe (1.43 ±0.08 vs 1.53 ± 0. 92), while mI/Cr was higher than control group in the temporal lobe(0. 51 ±0. 06 vs 0. 46 ± 0. 07 ) ( P ＜ 0. 05 ). Conclusion FA in the temporal and centrum semiovale regions of VCI group and NAA in the temporal white matter regions decreased obviously. DTI and MRS could provide a reference value for early diagnosis and assessment of VCI.