双能量CT头颅血管成像的影像质量、辐射剂量及初步临床应用

Objective To assess the clinical value of dual-energy intracranial CT angiography (CTA).Methods Forty-one patients suspected of intracranial vascular diseases underwent dual-energy intracranial CT angiography, and 41 patients who underwent conventional subtraction CT were enrolled as the control group.Image quality of intracranial and skull base vessels and radiation dose between dual-energy CTA and conventional subtraction CTA were compared using two independent sample nonparametrie test and independent-samples t test, respectively.Prevalence and size of lesions detected by dual-energy CTA and digital subtraction CTA were compared using paired-samples t test and Spearman correlative analysis. Results The percentage of image quality scored 5 was 70.7% (29/41) for dual-energy CTA and 75.6% (31/41) for conventional subtraction CTA.There was no significant difference between the two groups(Z= -0.455, P=0.650).Image quality of vessels at the skull base in conventional subtraction CTA was superior to that in dual-energy CTA, especially for the petrosal and syphon segment (Z=-4.087, P= 0.000).Radiation exposure of dual energy CTA and conventional CTA were (396.54±17.43) and (1090.95±114.29) mGy · cm respectively.Radiation exposure was decreased by 64% (t=-38.52, P=0.000) by dual energy CTA compared with conventional subtraction CTA.Out of the 41 patients,19 patients were diagnosed as intracranial aneurysm, 2 patients as arteriovenous malformation (AVM), 3 patients with Moya-moya's disease, and the remaining 17 patients with negative results.Nine patients with intracranial aneurysm, 2 patients with AVM, 3 patients with Moya-moya's disease, and 2 patients with negative findings underwent DSA or operation, with concordant findings from both techniques.Diameter of aneurysm neck, long axis and minor axis by dual-energy CTA was (2.90±1.61), (5.23±1.68) and (3.83±1.69) nun, respectively; Diameter of aneurysm neck, long axis and minor axis by DSA was (2.95±1.71), (5.10±1.60) ,(3.83±1.65) nan,respectively.There was no significant difference for the diameters of aneurysm between dual energy CTA and DSA ((t=-0.734,1.936,0.12.5 respectively, P=0.482,0.085,0.903 respectively), and good correlation was found between diameter measurements using the two techniques(r=0.964,0.976,0.973, respectively, all P=0.000) Conclusions Compared with conventional subtraction CTA, dual energy CTA has good image quality for intracranial vessels; however, image quality of the skull base vessels is worse, especially for the petrosal and syphon segment.Dual energy CTA has decreased radiation dose and a high diagnostic accuracy, being a practical imaging madality for diagnosis of intracranial vascular lesions.     

磁共振波谱分析海马诊断首发抑郁症

目的观察磁共振波谱分析(MRS)所示双侧海马代谢物改变对于诊断首发抑郁症(DD)的意义。方法对44例首发DD患者(DD组)及20名正常人(对照组)测量双侧海马肌酸(Cr)、N-乙酰天门冬氨酸(NAA)、胆碱(Cho)和肌醇(MI)峰下面积,计算NAA/Cr、Cho/Cr及MI/Cr,分析组间各指标差异;采用Logistic回归建立预测模型,以ROC曲线计算相关代谢物改变,作为首发DD临床诊断指标,并基于约登指数得出诊断阈值。结果DD组右侧海马Cho、NAA/Cr、Cho/Cr值均低于对照组(P均<0.05),右侧海马NAA、Cho、NAA/Cr、Cho/Cr和预测模型诊断DD的敏感度分别为54.54%、50.00%、45.45%、63.63%和77.27%,特异度分别为90.00%、100%、100%、80.00%和80.00%。结论MRS可辅助诊断首发DD;海马区Cho及Cho/Cr下降可能是早期DD标志,Cho、NAA/Cr及Cho/Cr可作为诊断首发DD的指标。     

3.0TMR三维高分辨成像序列联合MRVE在三叉神经痛术前评估中的应用

目的探讨3.0 T MR三维高分辨成像联合MR仿真内镜(MRVE)在三叉神经痛术前评估中的应用价值。方法回顾性分析2016年4月—2017年12月40例因原发性三叉神经痛(PTN)行微血管减压术(MVD)病人的资料,其中男21例,女19例,年龄37～86岁,平均(59.6±2.2)岁。所有病人均行3.0 T MR三维高分辨成像,进行双激发平衡式稳态自由进动(3D-FIESTA-c)和三维时间飞跃法MR血管成像(3D-TOF-MRA)序列扫描,并进行MRVE重建。采用χ~2检验比较三维高分辨成像及三维高分辨成像联合MRVE预判断责任血管的阳性率,并以手术结果作为金标准,分析上述2种成像方法对责任血管的检出率。结果术前40例病人采用2种成像方法检查,MR三维高分辨成像联合MRVE成像对责任血管压迫显示的阳性率(95%,38/40例)高于MR三维高分辨成像(85%,34/40例)(χ~2=1.826,P=0.04)。术中发现40例PTN病人均存在责任血管压迫,其中动脉压迫33例(82.5%)、单纯静脉压迫3例(7.5%)、动静脉混合压迫4例(10.0%)。2种成像方法对动脉压迫的检出率均为100%。MR三维高分辨成像联合MRVE成像对静脉及动静脉混合压迫的检出率(71.4%,5/7)高于单独MR三维高分辨成像(14.3%,1/7)。结论 MR三维高分辨成像序列联合MRVE技术能有效显示神经与血管的三维空间关系,能够对三叉神经痛的病因诊断提供重要价值。     

中枢神经系统Rosai-Dorfman病4例临床病理分析

目的探讨中枢神经系统Rosai-Dorfman病(Rosai-Dorfman disease,RDD)的临床病理特点、免疫表型、诊断及鉴别诊断、治疗及预后。方法回顾性分析2011年~2018年南京医科大学附属脑科医院诊治的4例中枢神经系统RDD的临床病理资料并复习相关文献,其中2例曾误诊为富于淋巴浆细胞型脑膜瘤。结果4例RDD中男性2例,女性2例,平均年龄48.75岁。镜下见病变组织细胞混合淋巴细胞、浆细胞成分呈结节状浸润,伴有纤维化或胶原化背景。组织细胞中可见典型的“伸入运动”,即胞质内可见吞噬的淋巴细胞、浆细胞及红细胞。免疫表型:组织细胞S-100、CD68、vimentin阳性,CD1a、BRAF V600E阴性,IgG4/IgG比值均<40%。结论中枢神经系统RDD是一种罕见的良性组织细胞增生性疾病,临床及影像常误诊为脑膜瘤。因此要提高对此类病变的认识,做出正确诊断,防止误诊。     

钆增强双能量CT诊断肺栓塞的实验研究

目的 评价含钆的MR对比剂进行双源双能量CT肺动脉成像(CTPA)用于诊断肺栓塞的可行性.方法 (1)用不同稀释浓度的碘对比剂和钆对比剂进行体外双源双能量CT成像,测量不同管电压条件下各样本的CT值.(2)10只新西兰大白兔以3和5 ml/kg分2组注射含钆对比剂进行双能量CT扫描,测量不同管电压下肺动脉的强化值.6只家兔在次日经股静脉注射明胶海绵栓子制作急性肺栓塞模型,2h后行双能量CT扫描.分别于2次扫描前经耳缘静脉或股静脉抽血2～3 ml行肾功能检查.方差分析和独立样本t检验用于分析不同组别肺动脉强化值的差别.结果 (1)同含碘对比剂相似,80 kV管电压条件下含钆对比剂的CT值高于140 kV和平均加权120 kV.(2)在管电压分别为140、80、平均加权120 kV时,双能量CT定量测量显示5 ml/kg组家兔主肺动脉[CT值分别为(463.1±118.0)、(664.2±188.0)、(522.9 ±137.7) HU]和肺动脉1级分支[CT值分别为(445.1 ±82.3)、(606.7 ±207.2)、(493.4±117.3)HU] CT值均高于3 ml/kg组[主肺动脉CT值分别为(258.1±55.1)、(384.0±92.3)、(295.4±73.6) HU,肺动脉1级分支CT值分别为(245.0±73.2)、(309.1 ±94.2)、(263.8 ±78.5) HU;P值均＜0.05].80 kV图像肺动脉主干和1级分支的CT值明显高于140 kV和平均加权120 kV(肺动脉主干:F =6.004,P=0.005;1级分支:F=4.374,P =0.018).6只栓塞组家兔CTPA显示两下肺动脉强化突然截断,对应的钆图显示钆含量降低,表现为蓝色伪彩色,正常非栓塞肺组织表现为红黄色伪彩色.3和5 ml/kg组肌酐增加率分别为6.7％和20.6％.结论 含钆MR对比剂具有与含碘对比剂相似的X线衰减特征,可用于对比增强的双能量CT肺成像中,同时提取出的CTPA以及显示肺灌注信息的钆图能够用于肺栓塞的诊断.     

脑灰质异位磁共振扩散张量成像的定量研究

目的：探讨脑异位灰质及其周边白质纤维束在磁共振扩散张量成像中的影像特点。方法：回顾性分析10例经MRI证实的脑灰质异位患者DTI图像。观察DTI及DTT图像灰质异位区周围脑白质形态,并在DTI图像上测量异位灰质及其周围脑白质、对侧脑白质及正常位置脑灰质各向异性分数（FA）值,比较异位灰质区脑白质与对侧大脑半球相同位置脑白质是否有统计学差异,并比较异位灰质区与正常位置灰质是否有统计学差异。结果：10例患者中Ⅰ型室管膜下型灰质异位有2例;Ⅱ型皮层下灰质异位有5例;Ⅲ型带状性灰质异位有1例;兼有上述两种或两种以上又出现Ⅳ型即混合型有2例。异位灰质区脑白质走行发生异常,呈受压推移或聚拢改变,无消融;异位灰质区脑白质与对侧大脑半球相同位置脑白质区的FA值间的差异无统计学差异（T=-0.435,P=0.669）;异位灰质区与正常位置灰质间的FA值大致相同（T=-0.000,P=1.000）。结论：异位灰质区白质纤维束形态发生改变,FA值与对侧白质纤维束相比,无明显下降;DTT可清晰显示异位灰质区脑白质的走行方向及形态。     

中枢神经系统肠源性囊肿(附3例报告并文献复习)

目的:探讨中枢神经系统肠源性囊肿(enterogenous cyst,EC)的MRI及病理学特点,以提高该病的诊断水平?方法:回顾性分析3例经手术证实的中枢神经系统EC患者的资料?结果:3例患者均行MRI平扫加增强检查?2例EC位于颈段硬脊膜下脊髓腹侧,1例EC位于左侧脑室三角区?其中2例信号均匀,1例混杂信号影,并有液平面?增强后显示3例病灶均无强化?显微镜下见囊壁由单层或复层柱状上皮细胞构成?结论:中枢神经系统EC有其特征性的MRI表现,MRI检查对其诊断具有重要价值,最终确诊依据病理检查?     

家兔急性肺栓塞模型双源CT双能量肺灌注成像与核素肺灌注显像

目的 探讨双源CT双能量肺灌注成像(DEPI)与核素肺灌注显像诊断实验性急性肺栓塞的价值.方法 24只家兔,20只采用股静脉入路注射明胶海绵制成急性肺栓塞模型,另外4只注射生理盐水作为对照组.栓塞后2 h行DEPI及核素肺灌注平面显像.以病理结果为金标准,比较两种方法在肺叶基础上诊断急性肺栓塞的准确性.比较增强DEPI图像上栓塞区与正常肺实质的CT值和强化值(Overlay值).结果 对照组DEPI图像表现为大致均匀的黄红色伪彩,栓塞后栓塞区肺灌注图像表现为灌注缺损,核素肺灌注显示栓塞区放射性稀疏或缺损;DEPI和肺灌注平面显像诊断肺栓塞的敏感度、特异度、阳性预测值、阴性预测值分别为100%、97.50%、95.24%、100%;67.50%、81.25%、64.29%、83.33%.增强后栓塞区和非栓塞区CT值及强化值的差异均有统计学意义(P<0.05).结论 与核素肺灌注显像相比,DEPI诊断实验性急性肺栓塞有更高的敏感度和特异度.     

双能量CT头颅血管成像的影像质量、辐射剂量及初步临床应用

Objective To assess the clinical value of dual-energy intracranial CT angiography (CTA).Methods Forty-one patients suspected of intracranial vascular diseases underwent dual-energy intracranial CT angiography, and 41 patients who underwent conventional subtraction CT were enrolled as the control group.Image quality of intracranial and skull base vessels and radiation dose between dual-energy CTA and conventional subtraction CTA were compared using two independent sample nonparametrie test and independent-samples t test, respectively.Prevalence and size of lesions detected by dual-energy CTA and digital subtraction CTA were compared using paired-samples t test and Spearman correlative analysis. Results The percentage of image quality scored 5 was 70.7% (29/41) for dual-energy CTA and 75.6% (31/41) for conventional subtraction CTA.There was no significant difference between the two groups(Z= -0.455, P=0.650).Image quality of vessels at the skull base in conventional subtraction CTA was superior to that in dual-energy CTA, especially for the petrosal and syphon segment (Z=-4.087, P= 0.000).Radiation exposure of dual energy CTA and conventional CTA were (396.54±17.43) and (1090.95±114.29) mGy · cm respectively.Radiation exposure was decreased by 64% (t=-38.52, P=0.000) by dual energy CTA compared with conventional subtraction CTA.Out of the 41 patients,19 patients were diagnosed as intracranial aneurysm, 2 patients as arteriovenous malformation (AVM), 3 patients with Moya-moya's disease, and the remaining 17 patients with negative results.Nine patients with intracranial aneurysm, 2 patients with AVM, 3 patients with Moya-moya's disease, and 2 patients with negative findings underwent DSA or operation, with concordant findings from both techniques.Diameter of aneurysm neck, long axis and minor axis by dual-energy CTA was (2.90±1.61), (5.23±1.68) and (3.83±1.69) nun, respectively; Diameter of aneurysm neck, long axis and minor axis by DSA was (2.95±1.71), (5.10±1.60) ,(3.83±1.65) nan,respectively.There was no significant difference for the diameters of aneurysm between dual energy CTA and DSA ((t=-0.734,1.936,0.12.5 respectively, P=0.482,0.085,0.903 respectively), and good correlation was found between diameter measurements using the two techniques(r=0.964,0.976,0.973, respectively, all P=0.000) Conclusions Compared with conventional subtraction CTA, dual energy CTA has good image quality for intracranial vessels; however, image quality of the skull base vessels is worse, especially for the petrosal and syphon segment.Dual energy CTA has decreased radiation dose and a high diagnostic accuracy, being a practical imaging madality for diagnosis of intracranial vascular lesions.     

平均心率、心率变异性和钙化负荷对双源CT冠状动脉成像诊断准确性的影响

目的 与常规冠状动脉造影(CAG)对照,评价双源CT冠状动脉血管成像(CTCA)诊断冠状动脉狭窄性病变的准确性以及平均心率、心率变异性和钙化负荷对CTCA诊断准确性的影响.资料与方法 2006年12月至2008年9月,113例患者同时进行了CTCA与CAG.以CAG为参照,评价CTCA诊断≥50%和>75%冠状动脉狭窄性病变的准确性.按心率、心率变异性和钙化积分将患者分组,评价不同亚组CTCA的诊断准确性,对敏感性和特异性数据进行χ~2检验.结果 以患者为分析单位,CTCA诊断≥50%和>75%冠状动脉狭窄性病变的敏感性和特异性分别为94%、93.3%;88.5%、96.2%;以血管为分析单位,CTCA诊断≥50%和>75%冠状动脉狭窄性病变的敏感性和特异性分别为90.0%、98.0%;84.8%、98.5%;而以节段为分析单位,CTCA诊断≥50%和>75%冠状动脉狭窄性病变的敏感性和特异性分别为89.9%、99.5%;83.0%、99.7%.平均心率对CTCA诊断冠状动脉狭窄无明显影响,而心率变异性和钙化积分对CTCA诊断冠状动脉狭窄有影响.结论 无论是以患者、血管还是节段为分析单位,CTCA在诊断冠状动脉狭窄方面均有较高的敏感性和特异性,平均心率对CTCA诊断冠状动脉狭窄的准确性无明显影响,而心率变异性和钙化积分对CTCA诊断冠状动脉狭窄的准确性有影响.