256层与64层螺旋CT在透析患者上肢CT血管成像中的对比研究

目的比较256层与64层螺旋 CT 在慢性肾衰竭透析患者上肢 CT 血管成像(CTA)检查中的效果.资料与方法回顾性分析23例上肢动静脉瘘造瘘患者的 CTA 图像,10例行64层螺旋 CT 检查,13例行256层 CT 检查,两组均采用对比剂追踪触发扫描技术.采用多平面重组、最大密度投影、容积成像、曲面重组等技术对扫描数据进行三维重建,比较两组患者的动脉分支级别、血管边缘、静脉干扰评分及瘘口娴熟情况.结果两组总体上均得到了较好的一致性评价;两组对肩部、上臂血管分支级别的显示能力差异无统计学意义(t =-0.96, P>0.05; t =0.19, P>0.05),对前臂、手部分支级别的显示能力差异有统计学意义(t =-3.17, P<0.01; t =-2.74, P<0.05);256层组对肩部、上臂、前臂血管边缘光滑度的显示质量优于64层组(t =-2.40, P<0.05;t =-2.08, P<0.05;t =-2.53, P<0.05);两组各区域静脉干扰评分及瘘口显示情况差异无统计学意义(P>0.05).结论相比于64层螺旋 CT,256层螺旋 CT 在血管、内瘘口、流入流出道的细节显示方面效果更佳.     

头颈CTA对比剂优化与成像质量相关性研究

目的:探讨头颈部16层螺旋CT血管造影(CTA)对比剂剂量优化与成像质量的相关性。方法:将80例头颈部CTA随机分为A、B 2组,各40例,分别采用常规剂量(65～90ml)与优化剂量(46～50ml)行16层螺旋CT动脉血管成像,利用原始图像、最大密度投影(MIP)及多平面重组(MPR)技术进行图像后处理,从而对CTA图像质量进行评价。结果:A、B 2组全程血管内浓度曲线波动甚微、形态基本一致,主观判断无明显差异,优化方案组能有效消除头臂静脉高密度伪影干扰,显著提高颈部动脉起始段及颅内动脉的显示能力,2组间差异有统计学意义(P<0.05);颈动脉远侧段图像质量,2组间差异无统计学意义(P>0.05);B组颅内静脉显影淡、动脉显示质量高,与A组比较差异有统计学意义(P<0.05)。结论:头颈部16层螺旋CTA对比剂剂量优化方案,能够明显减少上腔静脉、颅内静脉伪影,提高图像质量,完全满足临床诊断需要。     

窦汇区解剖形态的MR血管成像表现

目的 探讨窦汇区解剖形态的MR血管成像(MRA)表现及其临床意义。方法 对123例受检者常规进行T1WI和T2WI磁共振检查(1．5T)，以排除颅内占位性病变和血管畸形。然后进行窦汇区MR血流成像。其中72例采用了二维时间飞跃(2D TOF)磁共振静脉成像(MRV)方法，44例采用了三维相位对比(3D PC)MRA方法，7例志愿者同时采用了上述2种方法。结果 (1)横窦引流优势表现为右侧为主84例，左侧为主23例，基本相等16例。(2)按照上矢状窦、直窦和双侧侧窦吻合关系，全部病例可分为4型：第1型，包括2种情况：①上矢状窦和直窦汇合成一个真正的总池，从总池发出左右横窦；②上矢状窦和直窦在终末端分成2股，左右分支构成两侧侧窦。第2型，上矢状窦引流至一侧横窦，直窦引流至对侧横窦。第3型，上矢状窦和直窦汇合后主要向右侧横窦引流。第4型，上矢状窦和直窦汇合后主要向左侧横窦引流。结论 MRA是显示窦汇区解剖形态的有效方法，对窦汇区解剖形态分类有助于判断横窦引流优势和现存的和(或)潜在的代偿通道，可能对临床诊断和手术过程有所帮助。     

16层螺旋CT正常肺动脉管径的测量

目的:利用16层螺旋CT建立健康成年人肺动脉干及其主要分支直径的正常值标准。方法:选择没有心肺疾患及引起肺动脉压力及血流变化的相关疾病并行CT冠状动脉成像检查者,按年龄分为3组(<40岁组,40~60岁组和>60岁组),每组40例(男、女各20例),共120例。采用平静呼吸状态下深吸气末时增强扫描的图像进行测量并进行统计学分析。结果:肺动脉干、左肺动脉、右肺动脉直径存在明显的性别差异,并且随着年龄的增加,其直径呈递增的趋势,在不同年龄组之间差异具有显著性意义(P<0.05);右下肺动脉直径在各组内不存在明显的性别差异,但在40岁以下和60岁以上组之间差异有显著性意义(P<0.05),其余各支肺叶动脉在不同性别和各年龄组之间差异均没有显著性意义(P>0.05)。结论:16层螺旋CT能清晰显示肺动脉及其分支,肺动脉正常管径的测量可以为肺动脉及引起肺动脉形态改变的相关疾病的诊断提供有价值的影像学依据。     

正常胰腺组织的多层螺旋CT血流灌注研究

目的 探讨正常胰腺组织的多层螺旋CT血流灌注特点,为胰腺疾病的灌注成像提供理论依据.资料与方法 102例正常胰腺患者以性别、年龄和部位进行分组,行多层螺旋CT胰腺灌注扫描,测量各组胰腺不同部位组织的血流灌注量(BF)、峰值增强影像(PEI)、到达峰值时间(TTP)、血容量(BV),并进行统计学分析.结果 (1)性别组中,65例男性胰腺头、体、尾部的BF、PEI、TTP、BV值与37例女性比较:男性胰头部BV值低于正常女性,差异有统计学意义(P=0.009);男性胰体部BF、PEI、TIP、BV值均低于正常女性,其差异有统计学意义(P值分别为0.01、0.0001、0.025、0.009);男性胰尾部BF、PEI、BV值均低于正常女性,差异有统计学意义(P值分别为0.017、0.01、0.015).(2)年龄组分为40岁以下组、40～60岁组和60岁以上组,其中60岁以上组胰体部BV值较40岁以下组低,40岁以上组胰尾部BF值较40岁以下组低.(3)部位组中,胰头部与胰尾部的BF、PEI、TTP、BV之间有显著性差异(P<0.05),与胰体部之间无显著性差异(P>0.05);胰体部与胰尾部的BF、PEI、TTP、BV之间无显著性差异(P>0.05).结论 正常胰腺组织的血流灌注存在一定性别、年龄和部位差异,可为胰腺疾病的CT灌注成像提供参考.     

MSCTA在肝移植中的应用价值

目的:探讨多层螺旋CT血管造影(MSCTA)在肝移植中的临床应用价值.方法:病例组选择32例肝癌和肝硬化在移植前后行多层螺旋CT(MSCT)多期扫描,包括肝癌10例(肝癌组)、22例肝硬化CTP分级C级(肝硬化组).分别于肝动脉期和门脉期进行血管3D成像,重建方法包括MPR、MIP、VR.于MIP图像上分别测量腹腔动脉 (CA)、胃左动脉(LGA)、肝总动脉(CHA)、肝固有动脉(PHA)、肠系膜上动脉(SMA)及门静脉(PV)、脾静脉(SV)、肠系膜上静脉(SMV) 的管径.数据用SPSS10.0处理,资料用均数±标准差(±S)表示,两组均数比较采用t检验;多组间的比较用单因素方差分析(ANOVA),两两比较用q检验.P＜0.05有统计学意义.结果:肝动脉期血管成像可清晰显示扫描范围内的腹主动脉、腹腔干,胃十二指肠动脉,肝固有动脉,肝左、右动脉及其分支;门静脉期血管成像能清晰显示门静脉系统情况.病例组32例中有21例肝动脉及其分支解剖正常,MIP及VR所显示的正常解剖肝动脉无明显差异.病例组中11例、正常对照组6例显示肝动脉分支异常.于MIP像上能准确测量腹腔大动脉血管管径及门静脉、肠系膜上静脉及脾静脉的管径,对照组与肝硬化组及肝癌组动脉管径无统计学差异,而门脉高压患者门静脉主干、肠系膜上静脉及脾静脉的管径与对照组相比,差异有统计学意义(P<0.05).结论:肝脏MSCTA能准确显示血管解剖、变异及病变情况,对静脉、变异的肝动脉进行管径测量,掌握个体化肝脏血管变异及其血管大小信息,为手术方式、制订术中血管吻合方案提供客观依据,并监测术后血管并发症.     

食管癌螺旋CT灌注成像与肿瘤血管生成的相关性研究

目的探讨食管癌螺旋CT灌注成像与肿瘤血管生成的相关性。资料与方法对50例食管癌患者行多排螺旋CT灌注扫描,分析食管癌CT灌注成像参数血容量(BV)、血流量(BF)、平均通过时间(MTT)、表面通透性(PS)与微血管密度(MVD)及血管内皮生长因子(VEGF)表达之间的关系。结果 50例食管癌中,VEGF阳性表达率为62%(31/50),阴性表达率为38%(19/50),MVD值在两组间的差异具有统计学意义(P<0.05);BF值与MVD呈正相关(P<0.05),BV及PS值与MVD呈显著性正相关(P<0.01),MTT值与MVD无相关性(P>0.05);PS值与VEGF表达呈正相关(P<0.05),BF、BV及MTT与VEGF表达无相关性(P>0.05)。结论食管癌CT灌注成像能够在一定程度上反映活体的肿瘤血管生成状况。     

肺孤立性病灶16层螺旋CT首过期灌注成像与血管生成的相关研究

目的 应用16层螺旋CT灌注成像(CTPI)技术,探讨肺孤立性病灶各灌注参数与病灶的微血管密度(MVD)、血管内皮细胞生长因子(VEGF)的相关性. 资料与方法对52例肺孤立性病灶行16层螺旋CT首过期灌注成像,利用Body-perfusion软件进行后处理,获得感兴趣区的血流量(BF)、相对血容量(rBV)、毛细血管渗透性(Pm)、达峰时间(TTP)等灌注参数.其中39例手术患者的组织标本采用免疫组织化学染色后行MVD计数和检测VEGF表达.结果 恶性组和炎性组的BF、rBV、Pm等参数均高于良性组,差异有统计学意义(P均<0.05);恶性组和炎性组仅Pm差异有统计学意义(P<0.05).良性组的TTP略高于恶性组和炎性组,但各组间差异无统计学意义(P>0.05).恶性组和炎性组的MVD、VEGF表达强度均高于良性组,差异有统计学意义(P均<0.05);但恶性组和炎性组之间MVD、VEGF表达强度的差异无统计学意义(P>0.05).除TTP外,恶性组、炎性组和良性组的BF、rBV、Pm参数值与MVD、VEGF呈正相关(P均<0.05),其中以BF与MVD、VEGF和Pm与MVD、VEGF的相关性最高.结论 肺孤立性病灶的CTPI参数与其血管生成有良好相关性,能定量地反映其血管生成情况,有助于对良恶性病灶的鉴别诊断.     

颅内窦汇区MRV成像研究

目的探讨正常人窦汇区MRV表现。方法对120例正常人进行T1WI、T2WI、T2-FLAIR,DWI磁共振检查,并用3D-PC法进行窦汇区MRV成像。结果(1)横窦引流优势表现为右侧为主79例,基本相等13例,左侧为主28例。(2)按照上矢状窦、直窦和双侧横窦的吻合关系,可分为4型:Ⅰ型,有窦汇形成(36例),分3个亚型;Ⅱ型,无窦汇形成,双侧横窦之间无交通(34例),分为4个亚型;Ⅲ型,无窦汇形成,双侧横窦之间有交通(44例),分4个亚型;Ⅳ型,复杂型(6例),分2个亚型。结论MRV是显示窦汇区解剖形态及脑静脉血流的有效方法,对临床诊断和治疗有重要意义。     

MSCT上肢静脉直接成像技术的应用

目的 探讨多层螺旋CT(MSCT)成像技术在上肢CT静脉血管成像中的诊断价值。 方法 回顾性分析56例行上肢CT静脉血管成像患者的检查资料, 并对上肢静脉血管采用容积再现、最大密度投影、多平面重组、曲面重建等多种方式后处理, 选定A、B、C(肱骨内外髁连线向近心侧5 cm处头静脉和肱静脉的轴位图像;肱骨内外髁连线向近心侧8 cm处头静脉和肱静脉的轴位图像;锁骨下静脉的轴位图像)层面分别测量管腔内CT值。测量数据采用SPSS 17.0统计软件包分析, 对上肢静脉选定层面的静脉管腔内测量的数据采用单因素方差分析, 以P < 0.05表示差异有统计学意义。 结果 56例完成MSCT上肢静脉直接成像的患者中, 右上肢发现病变14例, 左上肢21例, 阳性率为62.5%(35/56), 同期行彩色多普勒超声检查, 阳性率为58.9%(33/56)。肱骨内外髁连线5 cm处各测量位置中静脉管腔内CT值的差异无统计学意义(肱静脉管腔:F=0.004, P>0.05;头静脉管腔:F=0.102, P>0.05)。肱骨内外髁连线8 cm处各测量位置中静脉管腔内CT值的差异无统计学意义(肱静脉管腔:F=0.007, P>0.05;头静脉管腔:F=2.271, P>0.05)。锁骨下静脉层面各测量点之间的CT值差异无统计学意义(F=0.001, P>0.05)。统计结果提示顺静脉血管方向不同位置静脉管腔内对比剂充盈均匀。上肢静脉远端主干管腔内对比剂浓度高于近心端管腔内对比剂浓度, 各层面之间CT值的差异有统计学意义(F=1441.52, P < 0.05)。提示顺静脉血流方向对比剂浓度逐渐减低。 结论 MSCT上肢静脉直接成像的优势在于可以较大范围显示上肢静脉全程, 清晰显示侧支循环, 明确血管狭窄、阻塞的原因, 了解周围结构情况, 辨别血栓形成时间等。该技术相对安全方便、创伤小, 减少了碘对比剂用量, 减轻了患者的经济负担。应用该技术能提高上肢静脉血栓的诊断率, 为临床选择适当的治疗方法提供了可靠的依据。     

Transverse sinus anomaly simulating a meningioma on CT scanning

A rare, anomalously dilated right, transverse sinus with involvememt of the torcular herophili strongly suggested the appearance of a meningiona on CT scanning. Carocid and vertebral arteriography did not reveal the nature of the abnormality, since there was only faint opacification of the anomalous vessel, which was interpreted as a faint tumor stain. Transjugular venography was necessary to establish this diagnosis. When a similar lesion is encountered on CT scanning and the transverse sinus is not clearly seen or arteriography, venography should be carried out to determine if the appearance is due to occlusion by a mass or, as in this case, anomalous dilatation of the sinus.     

Transvenous embolization of dural fistulas involving the transverse and sigmoid sinuses

Eleven patients with dural fistulas involving the transverse and sigmoid sinuses were treated by transvenous embolization with coils or liquid adhesives. Seven patients underwent preoperative embolization of the external supply followed by direct surgical exposure of the sinus: liquid adhesives were used in four patients and coils in the remaining three. Four of these patients had complete obliteration of their fistulas and there was 95% reduction in the remaining three. Four patients had transvenous placement of coils from a transfemoral approach. In three, the ipsilateral sigmoid sinus was thrombosed and a contralateral approach across the torcular herophili was used. Coils were used in all four patients; one patient also had liquid adhesives placed within the sinus. Complete cure was achieved in one patient, 95% reduction in another, and 50% and 40%, reductions in the remaining two. Two transient complications occurred, one related to venous occlusion secondary to liquid adhesives and another related to transient occlusion of the vestibular aqueduct. Obliteration of dural fistulas involving the transverse and sigmoid sinuses can be achieved by placement of embolic material within the involved sinus from a transvenous approach; both coils and liquid adhesives can achieve this goal.     

3D-CE MRA、2D-TOF MRA对颅内静脉窦血栓的诊断价值比较

目的比较3D—CEMRA和2D—TOFMRA对颅内静脉窦血栓的诊断价值。资料与方法8例经临床及影像学随访证实的颅内静脉窦血栓患者及8例健康志愿者分别行3D—CEMRA和2D—TOFMRA检查。由两名放射学医师共同回顾性阅片取得一致意见,病变组分别比较两种MRA技术单独应用MIP和MIP联合MPR、CPR及原始图像对血栓部位、血栓范围、窦腔闭塞及侧支静脉的检出率。对照组仅在MIP和原始图像上观察颅内静脉走行形态、信号强度。结果血栓共累及了20处颅内静脉窦,其中上矢状窦7处,窦汇区、左侧乙状窦及左侧横窦各2处,右侧横窦、右侧乙状窦各3处,右侧颈静脉球1处。在显示颅内静脉窦血栓范围、窦腔闭塞程度及侧支静脉方面,3D—CEMRA优于2D．TOFMRA（P值均〈0．01）。3D—CEMRA采用MIP联合MPR、CPR及原始图像优于单独采用MIP（P值〈0．01）。2D—TOFMRA采用MIP联合MPR、CPR及原始图像和单独采用MIP比较,二者并无明显差异（P值〉0．01）。结论对颅内静脉窦血栓的评价,3D—CEMRA优于2D—TOFMRA,多种后处理技术的联合应用能更好显示血栓的范围、窦腔闭塞的程度和侧支静脉循环。     

螺旋CT检测肺结节的低剂量优化选择及应用

目的:探讨低剂量螺旋CT对肺部结节灶扫描的最佳条件及其应用价值,并评价低剂量与常规剂量螺旋CT扫描的X线放射剂量比。方法:对75例88个肺内结节分别用200mA、40mA、30mA、20mA和10mA进行螺旋CT扫描。测量结节的最大径、CT值、最大CT值,记录结节的各种内部征象、噪声和伪影及每次扫描的单次CT剂量加权指数(CTDIw)及mA。结果:5种不同管电流扫描图像所示肺内结节灶的检出率、最大径、CT值及结节的各种内部征象,各组间差异无统计学意义(P>0.05),噪声和伪影10mA组高于其它组(P<0.05),200mA常规剂量组与低剂量各组比较CTDIw值差异有显著性意义(P<0.05)。结论:20mA是肺部扫描的最佳剂量,具有辐射量小、敏感性强、性价比高的特点,值得推广应用。     

鼻窦低剂量螺旋CT扫描的可行性探讨

目的:探讨鼻窦低剂量CT扫描的可行性,评估其影像效果。方法:对40例受检者在行鼻窦常规剂量(200mA)CT扫描后,再行低剂量(30mA)CT扫描;由2名医师盲法评价图像,按正常图像、图像有少许伪影、图像有严重伪影的等级对每一幅图像进行质量评判,并进行统计学处理。结果:98%以上鼻窦低剂量CT图像可以满足诊断需要,与常规剂量CT图像相比无显著性差异(P>0.05)。结论:鼻窦低剂量CT扫描是切实可行的,正确应用可以有效地保护病人和保证图像质量。     

The Assessment of Anemia From Attenuation Values of Cranial Venous Drainage on Unenhanced Computed Tomography of the Head

Objective

To determine if prediction of anemia is possible from quantitative analyses of unenhanced cranial computed tomography (CT) images.

Methods

A retrospective chart review revealed 101 patients who had hemoglobin and hematocrit levels obtained within 24 hours of an unenhanced cranial CT. Regions of interest were the place on the torcular Herophili (confluence of sinuses) and the left and right transverse sinuses. Attenuation values were correlated with hemoglobin and hematocrit to investigate any possible relationship.

Results

Hemoglobin levels were correlated with torcular and transverse sinus attenuation levels. For every 10 Hounsfield unit (HU) increase in torcular attenuation, hemoglobin levels increased by 16.3 g/L (P < .001). When subgroup analysis was performed, by sex, for every 10 HU increase in torcular attenuation, hemoglobin levels increased by 22.6 g/L (P < .001) in men and 8.96 g/L (P < .05) in women.

Conclusion

The attenuation values for venous drainage on unenhanced cranial CT constitute a practical adjunct in the assessment of anemia. Given the number of individuals undergoing CT without blood work, this rapid assessment technique for anemia is a convenient means for narrowing possible diagnoses.     

Investigation of fat in the dural sinus

Detection of fat in the cranium usually indicates the presence of a fat-containing tumor such as lipoma, dermoid cyst or teratoma. However, since 1982, Hasso et al demonstrated with CT the presence of normal adipose tissue in the cavernous sinus, the mere existence of fat in the cranium does not necessarily mean the presence of a fatty tumor. The author first described fat deposition in the superior sagittal sinus and torcular Herophili following a CT study performed in 1986. The purpose of this study was to investigate the distribution, frequency, and anatomical correlations of fat in the dural sinus as demonstrated on CT. Fat was detected in the cavernous sinus in 20% of all cases (492/2408), and occurred more frequently (25%) in those older than 50 years. Fat was less frequent in the other dural sinuses (3%; 75/2296). The most common location was the torcular Herophili, followed in decreasing order of frequency by the straight sinus, inferior sagittal sinus, superior sagittal sinus and transverse sinus. Pathological examination was performed in three cases. Fat deposition was composed of normal adipose tissue and was devoid of fibrous encapsulation or infiltration. In one case, the fat seemed to be partly exposed to the subarachnoid space on CT, whereas on autopsy, thin dura mater covering the fat nodule was confirmed. Fat in the dural sinus must be differentiated from cavernous nodule or sinus thrombosis. The Hounsfield unit may be helpful in making a definitive diagnosis.     

Gastric cancer: preoperative local staging with 3D multi-detector row CT--correlation with surgical and histopathologic results

PURPOSE: To prospectively evaluate accuracy of multi-detector row computed tomographic (CT) images for preoperative staging of gastric cancer by using surgical and histopathologic results as reference standards. MATERIALS AND METHODS: This study had institutional review board approval; informed consent was obtained from all patients. Multi-detector row CT included acquisition of virtual gastroscopy images after air distention and contrast material-enhanced dynamic transverse and multiplanar reformation (MPR) images after water distention. Fifty-five consecutive patients with gastric cancer (38 men, 17 women; age range, 37-84 years; mean age, 63 years) underwent preoperative CT. All received 6 g of gas-producing crystals before unenhanced CT scanning for gastric distention and virtual gastroscopy. Patients drank 800-1000 mL of tap water to establish a background for dynamic contrast-enhanced CT scans. Images were obtained in late arterial, portal venous, and delayed phases with start delays of 40, 70, and 150 seconds, respectively. All patients underwent surgery. CT findings were compared with surgical and histopathologic results. Differences in accuracy of transverse and MPR images for T and N staging were assessed with the McNemar exact test. Statistical significance was inferred at P < .05. RESULTS: Detection rates of primary tumors with transverse images, MPRs, and combinations of MPR and virtual gastroscopy images were 91% (50 of 55), 96% (53 of 55), and 98% (54 of 55), respectively. Overall accuracy in assessment of tumor invasion of the gastric wall (T stage) was significantly better with MPR images (89% [49 of 55]) than with transverse images (73% [40 of 55]) (P < .01). Overall accuracy for lymph node (N) staging was 78% (43 of 55) with MPR images and 71% (39 of 55) with transverse images. This difference was not significant (P = .103). CONCLUSION: Multi-detector row CT with combined water and air distention can improve the accuracy of preoperative staging of gastric cancer. MPRs yield significantly better overall accuracy than transverse images for tumor staging but not for lymph node staging.