运用自制模体定量评价三维数字减影血管造影测量误差的初步实验研究

目的探讨三维数字减影血管造影(3D-DSA)重建成像的测量误差。资料与方法在自制模体内放置9个直径为10mm的钢球,呈十字排列且平行于床面,钢球之间间隔3.5cm,钢球距床面高17cm,运用DSA机在视野20cm下做三维采集,将采集到的图像传至ADW4.3工作站行血管容积再现(VR)重建,在不同角度下测量每个钢球的直径,计算其放大率,比较不同区域的放大率,并观察钢球的变形失真情况。结果中央区放大率为-0.30%～0.30%,内带区放大率为0.30%～1.00%,外带区放大率为0.7%～1.70%。外带区放大率大于内带区和中央区(P<0.01),内带区放大率大于中央区(P<0.01)。钢球的变形失真率极小。结论 3D-DSA重建成像的测量能基本反映真实物体的大小及形状,其测量误差在介入手术中是可以接受的。     

三维DSA距离测量准确性的模体定量评价研究

目的：运用模体定量评估三维DSA距离测量的准确性,以指导临床工作。方法：应用模拟动脉瘤模体和动脉狭窄模体,改变不同的扫描野、重建矩阵、模体方向来研究三维空间距离测量的准确性。通过对模体中球体和圆柱体三维容积重建图像尺寸测量与模体实际尺寸进行对比评估。结果：在三维图像重建中不同的扫描野、重建矩阵、模体方向均能清晰显示圆柱体、球体影像及模拟狭窄的程度。随着扫描野的缩小,对球体直径和狭窄直径的测量精度提高,对于圆柱体长度测量元变化。重建矩阵加大,球体直径测量误差减少（1283最大为0．36mm,2563最大为0．12mm）。圆柱体狭窄百分率测量误差大约为3％。结论：当选用合适的图像成像参数和后处理方法时,利用重建后的三维图像测量动脉瘤的大小和动脉狭窄的程度是相当可靠的。     

垂体高度的断层解剖及MRI测量

目的：通过尸体断层标本和MRI对照测量垂体的高度，为垂体的影像学诊断提供诊断标准、材料和方法：利用35例成人尸体断层标本，在各个断面上测量垂体的高度；在103例成人冠状头颅MRI上测量垂体的高度，并按年龄和性别分为十二组。将断层标本和MRI的测量数据进行比较。结果：在断层标本上测量垂体的平均高度为5．3±0．6（4．0－7．6）mm；MRI上的平均高度为5．4±1．3（4.0－8．3）mm。两组数据比较，无显著性差异（P＞0．05）。男性垂体的平均高度为5．3±1.2（4．0－7．2）mm，女性垂体的平均高度为5．5±1．4（4．0－8.3）mm。女性垂体的平均高度大于男性。各年龄组比较显示，20岁以后，随年龄增长，垂体高度逐渐下降。结论：在MRI诊断中，垂体高度女性≥9mm，男性≥8mm可考虑垂体异常。垂体高度女性大于男性；20岁以后，随年龄增长，垂体高度有逐渐下降的趋势。     

膝关节软骨损伤的MR三维重建实验研究

目的 通过对关节软骨损伤的动物标本和MR三维及二维图像的精确测量,观察MR三维重建图像显示关节软骨损伤病变的能力及测量病变大小的准确性。材料与方法 采用新鲜猪膝关节,以外科方法制作2～4级的关节软骨损伤标本并进行MR扫描,最后在工作站对图像进行二维和三维重建并测量,与标本的实际测量结果相对照。结果 按照1mm、1．5mm、3mm扫描层厚分组,3、4级损伤的表面遮盖显示（SSD）三维重建图像测量值的平均百分误差比较结果：X^2=74．45,P〈0．01。SSD和最大信号强度投影（MIP）两种三维重建方式测量误差的差异经Fdedman Test检验具有统计学意义（X^2=8．65,P=0．013〈0．05）。对三组测量值进行方差分析,其差异具有显著的统计学意义（F=16．601,P〈0．01）。SSD三维重建图像对4级损伤测量的百分误差最小。对3、4级损伤测量值进行Mann-Whitney U检验,其差异具有统计学意义（Z=-2．24,P=0．025〈0．05）。测量关节软骨病变大小在1mm扫描层厚的SSD三维重建图像上较二维磁共振图像更为准确。采用随机区组秩和检验的Friedman Test（X^2=8．65,P=0．013〈0．05）。结论 三维重建测量误差的大小与MR扫描层厚三维重建方式、损伤区的大小和关节软骨损伤的程度等有关。关节软骨的三维重建图像能够较真实地反映关节软骨表面的不规则形态,测量线的方向不受扫描平面方向的限制,可以对任意两点间的距离进行测量。     

定量评估64层螺旋CT血管成像与DSA显示冠状动脉狭窄的能力和可靠性

目的定量评估64层螺旋CT（MSCT）与DSA2种成像方法显示冠状动脉狭窄及支架内再狭窄的能力和可靠性。方法应用心脏动态体模，设定心率为0、50、70、90次／min，对内径3mm的模拟冠状动脉（内设25％、50％、75％3段狭窄）及内径4mm的模拟带支架冠状动脉（支架段内设50％、75％2段狭窄）分别进行MSCT与DSA成像，将MSCT与DSA对应数据进行分析。结果（1）MSCT对25％、50％、75％3段狭窄的平均测量值为（30．0±1．4）％、（49．5±1．3）％、（72．9±3．9）％（P值分别为0．005、0．531、0．369）；DSA分别为（24．8±2．0）％、（48．2±2．1）％、（75．3±2．4）％（P值分别为0．883、0．180、0．796）。（2）MSCT图像伪影随心率增快而增加，心率≥70次／min影响变明显；DSA不受心率影响，所有心率下都可清晰地显示狭窄程度，无伪影。（3）MSCT与DSA测量血管狭窄程度有较好的相关性（r=0．995，P=0．000）。（4）MSCT可同时显示支架及支架内狭窄，但显示支架内狭窄能力有限，对50％狭窄分别显示为（46．4±4．5）％（心率为0）和（43．6±5．7）％（心率为50次／min），与标准值（50％）相比，差异有统计学意义（P〈0．05）。DSA可清晰显示支架内狭窄，但不能很好显示支架形态。结论（1）MSCT与DSA评价冠状动脉狭窄结果可靠，MSCT受心率的影响大，时间分辨率有待提高，作为排除性诊断有很高的临床应用价值；MSCT对于支架内再狭窄的判断尚有一定局限性，但在管径较粗和低心率条件下评价支架内再狭窄有一定价值。     

人腰椎体标本的区域骨密度分布特征

目的了解人腰椎椎体内松质骨骨密度（ＢＭＤ）区域分布情况，探讨区域骨密度（ｒＢＭＤ）变化规律。方法对２８具新鲜人Ｌ３椎体标本进行整体ＢＭＤ和ｒＢＭＤ定量ＣＴ（ＱＣＴ）测量，分别测量椎体前、左前侧、右前侧、左后侧、右后侧及中央６个区，以及椎体上、中、下三部分ＢＭＤ。多元回归分析整体ＢＭＤ与ｒＢＭＤ的关系。结果椎体下份骨密度最高（Ｐ＜０．０１）；椎体前区及左、右侧前区均数小于椎体左、右侧后区及中央区（Ｐ＜０．０１）。总体观椎体ＢＭＤ以后下部较高。多元回归显示椎体各部分中，椎体下１／３骨密度、横断区域中前区和中央区的标准偏回归系数为最大，说明椎体整体ＢＭＤ变化与椎体下份和椎体前中央区ｒＢＭＤ关系较密切。结论人腰椎椎体的骨密度分布不均匀，椎体总体骨密度变化与不同区域骨密度的密切程度不同，应加强骨密度变化“敏感区”的监测     

利用CT灌注成像研究转移性肺癌的血供

目的 利用CT灌注成像观察转移性肺癌的血供。方法 选取符合入选标准的肺部转移瘤患者19例，通过DSA导引下分别行支气管动脉和选择性肺动脉插管，插管后将患者平移至多层螺旋CT（MSCT）下分别行转移瘤的双导管增强的同层动态螺旋CT扫描，其中支气管动脉内对比剂流率为1．5ml／s，总量6～8ml，肺动脉导管内对比剂流率3ml／s，总量加ml，2次扫描间隔为10min。扫描后采用功能CT软件分别在转移瘤内选取3个不同感兴趣区，即高强化区、低（不）强化区和整个瘤体区进行灌注值和高峰强化值（PEI）测量，并描绘时间-密度曲线，同时测量转移瘤最大直径。结果经肺动脉和支气管动脉途径增强后肿瘤结节灌注值分别是133．70（29．00～346．75）和2．30（0～24．25）ml·min^-1·ml^-1，两者间差异具有统计学意义（z=-6．281，P〈0．01）；PEI值分别是100．00（20．75—428．60）和11．30（1．05～26．00）HU，差异也有统计学意义（z=-5．776，P〈0．01）。3个不同感兴趣区的肿瘤结节，经两种不同途径增强后灌注值和PEI值间差异均具有统计学意义（P〈0．05）；经肺动脉和经支气管动脉途径增强后灌注值与肿瘤结节直径均无相关关系（r值分别为-0．167和0．104，P〉0．05），而经肺动脉和经支气管动脉途径增强后肿瘤结节PEI值与结节直径均呈正相关（r值分别为0．421和0．405，P〈0．05）。结论 转移性肺癌血供主要来自于肺动脉，同时支气管动脉也参与了肿瘤的血供，随着肿瘤的不断增大，肺动脉和支气管动脉血供均不断增多。功能CT为活体状态下评价肺部转移瘤的肿瘤血管生成提供了良好的研究途径。     

阻塞性睡眠呼吸暂停综合征患者睡眠状态下低剂量多层螺旋CT研究

目的对睡眠状态下的阻塞性睡眠呼吸暂停综合征（OSAS）患者行低剂量动态多层螺旋CT（MSCT）扫描，分析睡眠状态下气道实际阻塞或狭窄的部位、累及范围及动态变化，以修正静态气道测量的不精确性。方法16例OSAS患者分别行清醒平和呼吸状态下（简称清）与睡眠状态吸气末相（简称吸）、睡眠状态呼气末相（简称呼）下低剂量MSCT扫描，并于睡眠吸气末状态下气道最狭窄处行动态电影扫描。以睡眠吸气末状态下软腭后区（RP）、舌后区（RG）气道最狭窄处及会厌后区（EPG）会厌尖下5mm处为3种状态下的测量层面，比较3种状态下咽腔各层面的测量值并记录各期相气道最狭窄的具体部位。结果RP区气道最小横截面积（XSA）（M清=47．50mm^2，M呼=73．00mm^2，M吸=2．00mm^2；Z清呼=2．897，P清呼=0．003；Z清吸=4．192，P清吸〈0．01；Z吸呼：4．538，P吸呼〈0．01）的测量结果在3种状态下差异均有统计学意义；RP区前后径（AP）（M清=8．00mm，M呼=9．50mm，M吸=1．50him；Z清呼=1．933，P清呼=0．056；Z清吸=3．720，P清吸〈0．01；Z吸呼=4．230，P吸呼〈0．01）、左右径（LR）（M清：8．00mm，M呼=9．00mm，M吸=1．00mm；Z清呼=1．210，P清呼=0．246；Z清吸：4．203，P清吸〈0．01；Z吸呼：4．557，P吸呼〈0．01）、RP区气道体积（M清=4．06mm^3，M呼：5．50mm^3，肘吸=1．50mm^3；Z清呼=1．576，P清呼：0．125；Z清嗳=3．532，P清嗳〈0．01；Z吸呼=4．077，P吸呼〈0．01），RP（M清=7．00mm，M呼=6．00mm，M吸=10．50mm；Z清呼=0．557，P清呼=0．603；Z清吸=2．541，P清吸=0．011；Z吸呼=2．852，P吸呼=0．004）、RG（M清=5．00mm，M呼=3．00mm，M吸=9．50mm；Z清呼=0．747，P清呼=0．482；Z清吸=2．657，P清吸=0．007；Z吸呼=3．075，P吸呼=0．001）区咽后壁至椎体前缘垂直距离的测量结果，睡眠吸气末相与清醒或睡眠呼气末相差异有统计学意义。睡眠状态下动态电影扫描可直观、清晰地显示咽腔的形态学变化。结论（1）睡眠吸气末相对OSAS患者咽腔狭窄或闭塞的CT定位是最精确的，可明显降低清醒状态下测量的假阴性。（2）低剂量NSCT可明显减少对患者的放射剂量。     

副肝静脉在Budd-Chiari综合征诊断与治疗中的价值

目的探讨副肝静脉的影像学诊断标准，评价副肝静脉在Budd-Chiarih综合征诊断与治疗中的价值。方法通过100例下腔静脉和（或）肝静脉造影，观察副肝静脉的发生率，测量副肝静脉主干和口部的直径，观察33例离体肝脏标本中副肝静脉的发生率，测量副肝静脉口部的直径。结果副肝静脉在Budd-Chiari综合征中的发生率为69％，主干和开口直径为12．5±5mm。副肝静脉在肝脏标本中的发牛率为57％，开口直径为7．0±2.9mm，副肝静脉开口在Budd-Chiari综合征时明显大于肝脏标本（P＜0.01）、结论副肝静脉在肝静脉阻塞时起到代偿肝脏血液回流的作用。作者肯定了副肝静脉的影像解剖、影像了诊断在Budd-Chiari综合征的诊断与治疗中的价值。     

64层CT血管造影诊断颈内动脉狭窄及内膜切除术或支架置入术后随访的价值

目的通过与DSA对比，评价64层容积CT血管造影（CTA）诊断颈内动脉（ICA）狭窄，及其在内膜切除术和支架置入术后随访中的价值。方法同时进行CTA和DSA检查的短暂性脑缺血患者40例，根据北美症状性颈内动脉内膜剥脱术实验（NASCET）的方法，由2名不了解患者情况的放射科主任医生分别对80支颈内动脉进行CTA的曲面重建和DSA测量。以远心端颈内动脉作为参考，以DSA为金标准，以狭窄率50％及70％为界计算CTA敏感度、特异度、阴性预测值和阳性预测值等。内膜切除术和支架置入术前、术后CTA测得的ICA狭窄处直径及横切面面积的比较用配对t检验。结果以狭窄率超过70％为标准，37支血管中35支DSA和CTA检查结果一致（95％），CTA的敏感度、特异度、阴性预测值和阳性预测值分别为97％[95％可信限（CI）为85％-100％]、95％（95％CI为82％-100％）、95％（95％CI为82％-100％）、98％（95％CI为92％-100％）。CTA检测内膜切除术和支架置入术后ICA狭窄处直径及横切面面积较术前有显著增加，差异有统计学意义（P〈0．01）。结论CTA是筛查ICA狭窄的一种有效手段，也可作为ICA内膜剥脱术和支架置入术后随访的首选方法。     

DSA图像测量技术在缺血性脑血管病介入治疗中的应用

目的:探讨DSA图像测量技术在缺血性脑血管病介入检查及治疗中的应用价值。方法:对我院介入中心近期100例缺血性脑血管病血管狭窄患者在全脑血管造影检查及介入治疗过程中,应用DSA图像测量技术对狭窄血管进行测量并进行狭窄百分比分析计算。结果:应用DSA图像测量技术对本组病例中的血管狭窄病变进行测量,应用直径为10mm的正圆形不锈钢球作为参照物,并且尽可能将其放置在与预测量血管或病变同侧同一平面位置接近的部位,其测量数值与实际大小非常接近;对于颅外段狭窄病变,可以应用带有标准刻度(mm为单位)的导管或导丝作为参照物,进行测量时很少产生误差。结论:DSA图像测量技术对缺血性脑血管病检查及治疗具有重要的指导意义,能够正确评价血管的狭窄程度,对于介入操作医生选择合适的支架、保护过滤伞及扩张球囊等材料的种类、型号至关重要。     

Accurate geometric calibration in stepping-table digital subtraction angiography

Accurate measurements of vessel dimensions are desirable in many clinical applications. This work uses the known relative motion between X-ray source and the patient in stepping-table digital subtraction angiography (DSA) to provide an accurate geometric calibration for quantitative measurements. The method results in a calibration factor that converts the size of the object measured in pixels on the image to its size in millimetres. The main sources of error relate to: (i) the assessment of relative displacement of a structure in a series of images; (ii) patient motion throughout data acquisition; and (iii) image distortion. Error was evaluated both with a test object consisting of a large grid of ball bearings (2x2 cm spaced) and, in vivo, in five renal DSA examinations performed with identical catheters of known diameter. The calibration factor was calculated with 0.1% accuracy for the test object and at least 2% accuracy in vivo, even with breath holding and pulsatile motion. This demonstrates that the calculation of the calibration factor can be very accurate, and that the method we propose is capable of the submillimetre accuracy required for clinical studies if used in conjunction with an accurate measurement of the vessel size in pixels. In conclusion, accurate geometric measurements can be performed in stepping-table DSA, without the need for external reference objects.     

Quantitative digital subtraction arteriography with a calibration catheter

Quantitative intraarterial digital subtraction arteriography (DSA) was performed using a calibration catheter with three distal metallic ring markers. The two outer markers were 50 mm apart, and the third marker was in the middle. Measurements of 54 vessel diameters of the abdominal aorta, renal, lumbar, and iliac arteries were performed in a comparison study with direct film arteriograms in 10 aortofemoral runoff studies. Diameter measurements were made by both the observer on hard copy DSA images and by a computer using modified semiquantitative software. Against measurements on film, which were used as the standard, deviations in measurement on digital images varied from 8 to 13% for arterial diameters <5 mm and from 2 to 6% for diameters ≥5 mm. Projectional artifacts caused 3% or less error. Knowing these variations in measurement is important in order to determine error tolerances for clinical applications. The calibration catheter serves as a convenient internal marker for DSA.     

CT血管成像对肝细胞癌合并肝动脉-门静脉分流的诊断价值

目的探讨CT血管成像（CTA）对肝细胞癌（HCC）合并肝动脉-门静脉分流（APS）的诊断价值。方法127例HCC患者分别接受肝脏多层螺旋CT动态增强扫描和DSA检查，间隔时间3-15d。所有患者进行CTA检查，并以DSA为标准，对照分析CT动态增强扫描基础上进行CTA成像对APS的诊断价值。结果DSA证实52例（40．94％）HCC患者合并APS，中央型33例，周围型19例。CT横断面与横断面基础上结合CTA诊断APS的敏感度均为94．23％（49／52），特异度分别为84．00％（63／75）和97．33％（73／75），正确率分别为88．19％（112／127）和96．06％（122／127），阳性预测值分别为80．33％（49／61）和96．08％（49／51），阴性预测值分别为95．45％（63／66）和96．05％（73／76）。CTA排除了横断面CT对4例中央型APS和6例周围型APS的假阳性诊断。与DSA比较，多层螺旋CT对APS的分型符合率达88．46％（46／52），其中，中央型90．91％（30／33），周围型84．21％（16／19）。CTA还直观地显示23例重度分流中央型APS的供血动脉，其中19例为肝固有动脉分支，4例为胃十二指肠动脉分支。结论在多层螺旋CT动态增强扫描基础上进行CTA成像，能有效提高APS诊断的特异度和正确率。     

Carotid artery stent implantation: evaluation with multi-detector row CT angiography and virtual angioscopy--initial experience

Approval for this HIPAA-compliant study was obtained from the institutional review board; informed consent was not required for retrospective review of patient studies that had been performed for clinical evaluation. The purpose of this study was to retrospectively compare the accuracy of intrastent luminal diameter, as measured on transverse computed tomographic (CT) angiograms and virtual angioscopic views, with the manufacturer's specifications for phantom diameter and with digital subtraction angiographic (DSA) measurements of stent diameter obtained in patients. Intrastent diameter was measured by using standard and stent-optimized reconstruction kernels with three window settings. Endoluminal virtual angioscopic views of the stent-containing vessels were also generated. Measurements at CT angiography were compared with known specifications for the phantom and with DSA measurements in patients. Erroneous measurements of intrastent diameter occurred when a standard kernel and nonoptimized window settings were used. A set of parameters that minimized error relative to measurements obtained at DSA was also identified. Virtual angioscopy helped demonstrate morphologic aspects of stenosis that were otherwise difficult to appreciate.     

Exact measurement of vascular lumina in digital subtraction arteriography (DSA) during stent implantations and percutaneous transluminal angioplasty (PTA)

There are inherent difficulties in using high-resolution DSA in interventional radiology for measuring vascular luminal diameter since enlargement ratios are not constant. We present a system that permits accurate determination of vascular lumen diameters by means of a special angiographic catheter with pre-defined marking points. The accuracy of this measuring method was explored in tests using phantoms. In vivo practicability of the method was proved in PTA and stent implantations in 39 patients. This method with a maximum error of measurement of 5% appears to provide adequate safety in the choice of suitable dilating balloons and stents in interventional vascular procedures. In follow-up, it permits the accurate measurement of neo-intimal thickness.     

Size estimation and magnification error in radiographic imaging: implications for classification of arteriovenous malformations.

PURPOSETo assess magnification error in digital subtraction angiography as it pertains to arteriovenous malformation (AVM) size.METHODSA rectangular grid phantom with equally spaced markers mounted in a stereotactic frame was imaged with digital angiographic equipment. The location and orientation of the grid was altered relative to the central plane of the phantom. Both linear and area measurements were made according to the perceived location of phantom markers using a standard catheter calibration technique and compared with stereotactically derived estimates. Finally, a single case example of an angiographically imaged rolandic AVM was used to compare linear dimensions obtained with both described techniques.RESULTSThe determination of location and size with standard angiographic imaging is subject to error because of the divergent geometry of the incident x-ray beam. The resulting nonconstant geometric magnification causes errors in linear measurements of 10% to 13% at depths of 7 cm from the calibration plane. Errors in area measurements at the same position increase by 20% to 25%. Measurements of maximum diameter or cross-sectional area may have an additional error when nonspherical objects are inclined to the viewing direction (40% at 45 degrees inclination). These errors are reduced to less than 1 mm using the stereotactic technique. Some commercial angiographic systems have internal software to enable a spatial calibration based on known distances in the image or on the diameter of a catheter. The catheter technique was accurate in the calibration direction (perpendicular to the catheter axis) but had a 12% error in the direction parallel to the catheter because of a nonunity aspect ratio in the video system. Measurement of the dimensions of a rolandic AVM using the catheter calibration technique had an error that ranged from -3% to +26% (standard error, 20%) with respect to the stereotactic technique.CONCLUSIONSNumerous nonstereotactic referential systems for determining linear distances are inherently erroneous by varying degrees compared with the stereotactic technique. Area and volume determinations naturally increase this error further. To the extent that no standardized method for determining linear distances exists, significant variations in estimation of AVM size result. Classification schemes for AVMs have been hampered by this technical error.     

胸腰椎影像学测量及其临床意义

目的通过测量国人脊柱胸腰段（T11～L4）椎体高度、矢状径、横径,为设计胸腰椎椎体内固定器提供理论依据。方法健康正常人50例（男女各25例）,年龄18～60岁（平均30.6±10.5岁）,无腰椎病变者行CT扫描,分别测量胸腰椎椎体高度及椎体上、中、下矢状径和横径。结果胸腰椎椎体高度从T11～L4逐渐增高,中央高度与前缘高度、后缘高度比较,以中央高度最小,其范围为20.45～25.55mm（女：19.77～25.30mm）,前缘高度为21.24～27.41mm（女：20.84～26.22mm）,后缘高度为22.60～26.76mm（女：21.68～26.14mm）;正中矢状径、横径从T11～L4逐渐增大,椎体中部的矢状径和横径与椎体上、下的矢状径和横径比较,有显著差异（P〈0.05）,以腰部最小,其范围分别为28.56～33.36mm（女：27.63～31.42mm）、32.71～46.57mm（女：31.68～44.83mm）。椎体上矢状径和横径范围分别为30.67～37.71mm（女：29.23～36.51mm）、36.85～51.81mm（女：34.31～48.89mm）。椎体下矢状径和横径范围分别为32.24～39.31mm（女：31.14～37.99mm）、38.97～52.94mm（女：37.88～50.80mm）。总体观椎体上下呈向中间凹陷,腰部凹陷的类圆柱体。结论设计胸腰椎单椎体内固定器械时应考虑到各椎体高度及矢状径、横径的大小不同。     

High-spatial-resolution MR angiography of renal arteries with integrated parallel acquisitions: comparison with digital subtraction angiography and US

PURPOSE: To retrospectively compare three-dimensional gadolinium-enhanced magnetic resonance (MR) angiography, performed with an integrated parallel acquisition technique for high isotropic spatial resolution, with selective digital subtraction angiography (DSA) and intravascular ultrasonography (US) for accuracy of diameter and area measurements in renal artery stenosis. MATERIALS AND METHODS: The study was approved by the institutional review board, and consent was obtained from all patients. Forty-five patients (17 women, 28 men; mean age, 62.2 years) were evaluated for suspected renal artery stenosis. Three-dimensional gadolinium-enhanced MR angiograms were acquired with isotropic spatial resolution of 0.8 x 0.8 x 0.9 mm in 23-second breath-hold with an integrated parallel acquisition technique. In-plane diameter of stenosis was measured along vessel axis, and perpendicular diameter and area of stenosis were assessed in cross sections orthogonal to vessel axis, on multiplanar reformations. Interobserver agreement between two radiologists in measurements of in-plane and perpendicular diameters of stenosis and perpendicular area of stenosis was assessed with mean percentage of difference. In a subset of patients, degree of stenosis at MR angiography was compared with that at DSA (n = 20) and intravascular US (n = 11) by using Bland-Altman plots and correlation analyses. RESULTS: Mean percentage of difference in stenosis measurement was reduced from 39.3% +/- 78.4 (standard deviation) with use of in-plane views to 12.6% +/- 9.5 with use of cross-sectional views (P < .05). Interobserver agreement for stenosis grading based on perpendicular area of stenosis was significantly better than that for stenosis grading based on in-plane diameter of stenosis (mean percentage of difference, 15.2% +/- 24.2 vs 54.9% +/- 186.9; P < .001). Measurements of perpendicular area of stenosis on MR angiograms correlated well with those on intravascular US images (r(2) = 0.90). CONCLUSION: Evaluation of cross-sectional images reconstructed from high-spatial-resolution three-dimensional gadolinium-enhanced MR renal angiographic data increases the accuracy of the technique and decreases interobserver variability.     

CT横断序列辅助三维容积测量技术评估房间隔缺损的可行性研究

目的:探讨CT横断序列辅助三维容积测量（CTAS）技术评估房间隔缺损（ASD）的可行性。方法:回顾性收集2016年1月至2019年12月在阜外医院成功行介入治疗的单发继发孔型ASD患者。患者于封堵前及封堵后第2天均行冠状动脉CT血管成像（CTA）检查,且ASD封堵术中行DSA检查。最终入组52例,其中37例为缺损后下缘...