对比剂不同注射速率在低剂量CT肺动脉成像中的应用

目的分析对比剂不同注射速率(碘普罗胺300mgI/ml)在低剂量CTPA成像中应用的可行性。方法纳入60例临床疑似肺动脉栓塞拟行CTPA检查的患者,随机数字表法分为A、B、C三组,每组各20例,A组注射速率为5ml/s,对比剂用量35ml,延迟时间采用团注测试法(bolus test);B、C两组注射速率分别为4ml/s、3.5ml/s,对比剂用量25ml,延迟时间采用团注追踪(bolus tracking)技术。三组均采用管电压80kV、固定毫安秒80mAs,iDose43级迭代重建算法重建。分别测量肺动脉主干及分支的CT值并计算其平均值,对三组图像的肺动脉平均CT值、信噪比(SNR)、对比噪声比(CNR)、主观图像质量评价、有效剂量(ED)等进行比较分析。结果随着注射速率的降低,三组图像肺动脉平均CT值依次降低,但肺动脉CT值均高于300HU,能满足临床诊断需要,且肺动脉平均CT值、SNR、CNR、ED、主观图像质量评价相比差异均无统计学意义(P>0.05)。结论采用3.5ml/s注射速率,25ml的对比剂用量,肺动脉CTPA低剂量成像质量不仅能满足诊断需要,而且降低了碘摄入量和碘流率(iodine delivery rate,IDR),有效地减少对比剂肾病及对比剂外渗风险,值得推广应用。     

光子双源CT Flash模式联合低浓度对比剂在肺动脉成像中的应用

目的:探讨光子双源CT Flash模式联合低浓度对比剂在肺动脉成像中的临床应用.方法:200例临床怀疑肺动脉栓塞的患者随机分为A、B、C、D四组,各组50例,对比剂注射方案:A组,40mL对比剂+40mL生理盐水,流率4.0 mL/s;B组,40 mL对比剂+40 mL生理盐水,流率4.0 mL/s;C组,40 mL对比剂+40 mL生理盐水,流率4.5 mL/s;D组,40 mL对比剂+40 mL生理盐水,流率5.0 mL/s.A组对比剂采用欧乃派克(350 mg I/mL),B、C、D对比剂采用威视派克(270 mg I/mL).分析比较各组图像质量、客观评价指标及辐射剂量、碘总量.结果:患者的一般资料及CTDlvol、DLP、ED差异无统计学意义(P＞0.05).A组与其他三组相比,摄入的碘总量每位患者减少了3200mg.四组间主观评分差异有统计学意义(P＜0.05),D组优良评分病例数最多(40例).4级肺动脉显示率B组98.4％,其他三组为100％,差异有统计学意义(P＜0.05),A、D两组5、6级肺动脉显示率高于B、C两组,差异有统计学意义(P＜0.05).D、A组各支血管CT值、SNR、CNR高于B、C两组,差异有统计学意义(P＜0.05);左、右肺上叶动脉、下叶动脉噪声有差异(P＜0.05).A、D两组各支血管CT值均大于250 HU,B组共有37支血管CT值＜250 HU,C组病例共有10支血管CT值＜250 HU(P＜0.05).结论:光子双源CT Flash模式联合低浓度对比剂(270 mg I/mL),注射流率5.0 mL/s的扫描方案在肺动脉血管成像中可获得满意的图像质量,同时降低患者的碘对比剂用量.     

等渗低浓度对比剂肺动脉CT血管成像临床应用研究

【摘要】目的：评估等渗低浓度对比剂在肺动脉CT血管成像（CTPA）中应用的可行性。方法：临床疑似肺动脉栓塞行CTPA检查的患者60例,随机等分为低浓度组和对照组。低浓度组和对照组对比剂分别为碘克沙醇40mL（270mg I/mL）或碘普胺40mL（370mg I/mL）。对两组的图像质量评分、平均CT值、噪声值、图像信噪比(SNR)、对比噪声比(CNR)、容积CT剂量指数(CTDIvol)和剂量长度乘积(DLP)进行正态分布检验,符合正态分布则应用独立样本t检验,不符合正态分布则使用秩和检验,应用χ2检验比较两组间上腔静脉硬化伪影显示率和肺动脉栓塞诊断阳性率差异。结果：低浓度组和对照组受试者的年龄、性别、身高、体重及BMI差异均无统计学意义。两组图像质量评分、腔静脉评分、肺动脉主干及左、右干平均CT值、噪声、SNR及CNR差异均无统计学意义（P>0.05）。低浓度组上腔静脉CT值低于对照组,差异有统计学意义（P<0.05）。低浓度组的辐射剂量CTDIvol和DLP与对照组相比差异无统计学意义（P>0.05）。结论：等渗低浓度对比剂CTPA图像质量满足诊断要求,减少了患者碘负荷。     

管电压80kVp时不同浓度对比剂CTPA图像质量的自身对照实验研究

目的 探讨管电压80 kVp条件下保证兔CT肺动脉血管成像(CTPA)图像质量的最低碘对比剂浓度.方法 新西兰大白兔10只,每只间隔3d各行4次CTPA检查,碘对比剂浓度分别为350、300、270、250 mg I/mL.测量肺动脉主干及其同层面空气、左右肺动脉、上肺及下肺段以下肺动脉CT值,计算噪声(N)、对比噪声比(CNR)及信噪比(SNR),均以x-±s表示,采用单因素方差分析进行比较,多重比较采用Dunnettt检验.同时将肺动脉以段级肺动脉为界分为大血管和小血管,采用多个样本比较的Krskal-Wallis H检验,编秩后行LSD-t检验进行多重比较.不同观察者间及同一观察者不同次测量(间隔1月)肺动脉CT值采用配对t检验,血管评分采用配对样本比较的Wilcoxon符号秩检验.结果 不同对比剂浓度的CTPA均可显示6级肺动脉分支.270组肺动脉CT值[主肺动脉(687.17±167.83) HU]与最高的300组无明显差异[主肺动脉(848.68±185.03) HU](t =-161.52,P=0.097).270组CNR(6.3±1.30)及SNR(10.9±2.01)最高(t=-45.99,P=0.008;t=3.73,P=0.088),而N(62.84±6.05)最低(t=-11.09,P=0.016). 270组与其他3组间对于大血管评分无统计学差异(350～250组依次为3.91±0.35,3.90±0.38,3.90±0.42,3.86±0.42,H=6.588,P=0.086).270组对小血管评分低于350组及300组,但达到诊断要求(3.34±0.51).结论 管电压80 kVp时,兔CTPA检查采用270 mg I/mL碘对比剂较合适,可有效降低碘单位注射剂量.     

对比剂注射方式对CT门静脉成像质量的影响

目的 :探讨对比剂注射方式对CT门静脉成像质量的影响。方法 :选取行双源CT门静脉血管成像,且符合纳入标准的116例患者进行研究,通过抽签法分为研究组(n=63)与对照组(n=53)。研究组先以4.0 mL/s的流率注射碘佛醇(370 mg I/mL)60 mL,后以2.0 mL/s的流率注射碘佛醇30 mL,再用30 mL生理盐水以3.0 mL/s的流率冲管;对照组先以3.0 mL/s的流率注射碘佛醇(370 mg I/mL)90 mL,再用30 mL生理盐水以3.0 mL/s的流率冲管。由2位有经验的技师对2组图像质量进行评分,并测出门静脉主干、门静脉左右支主干、脾静脉和门静脉主干-肝实质CT值,对比2组所测CT值。对2位技师的CTV图像质量评分的一致性行Kappa检验;2组测量图像质量评分及CT值数据比较采用两独立样本t检验。结果:2位技师对2组图像质量评分一致性好(K=0.839)。2组门静脉主干、门静脉左右支主干、脾静脉、门静脉主干-肝实质的CT值和图像质量评分比较,差异均有统计学意义(均P0.05)。结论:对比剂以不同流率相结合的注射方式能够提高门静脉成像质量,减少其他血管的干扰。     

CT肺动脉造影评价慢性血栓栓塞性肺动脉高压的血流动力学

目的 探讨多层螺旋CT肺动脉造影 (CT pulmonary angiography,CTPA)与慢性血栓性肺动脉高压血流动力学关系.方法 回顾性纳入2006-01-2009-10慢性肺栓塞患者55例,评价CT肺动脉栓塞指数(CT pulmonary artery obstruction index, CTPAOI)及CTPA参数.根据CTPA图像采用Qanadli栓塞指数和Mastora栓塞指数计算 CTPAOI.CTPA参数均在轴位图像测量,包括主肺动脉直径、主肺动脉与升主动脉直径比、右室左室直径比等.结果 55例CTEPH患者Qanadli栓塞指数为(37.60±15.22)%,Mastora栓塞指数为(30.02±16.43)%,Qanadli 栓塞指数高于Mastora栓塞指数, Z=-6.296,P=0.000;但二者显著正相关,r =0.875,P=0.000.无论Qanadli栓塞指数还是Mastora栓塞指数与血流动力学参数之间均无显著相关性(P>0.05).CTPA参数与血流动力学参数相关分析显示右室左室直径比与肺动脉收缩压(r=0.240,P=0.021)、肺动脉舒张压(r=0.255,P=0.014)、平均肺动脉压(r=0.217,P=0.037)、肺毛细血管嵌压(r=0.318,P=0.002)、肺血管阻力(r=0.369,P=0.000)呈正相关;右肺动脉干直径、右室与左室比、右室前壁厚度为平均肺动脉压的独立因素.结论 采用Qanadli栓塞指数和Mastora栓塞指数不能反映慢性血栓性肺动脉高压血流动力学变化,但CTPA参数能够从不同方面反映血流动力学状态.     

80kV条件下碘克沙醇（270mgI/mL）在CTPA检查中的研究

目的：探讨80 kV 条件下碘克沙醇(270 mg I/mL)应用于 CT 肺动脉血管成像(CTPA)检查的可行性。方法将90例拟行 CTPA 检查的患者随机分为 A 组和 B 组。A 组45例：应用270 mg I/mL 碘对比剂同时使用自适应统计迭代重建(ASIR),管电压为80 kV,自动 mA;B 组45例：应用370 mg I/mL 碘对比剂同时使用滤波反投影(FBP)重建,管电压为120 kV,自动 mA。2组使用对比剂的总量均为40 mL。记录2组的容积 CT 剂量指数(CTDI)、剂量长度乘积(DLP)。对2组图像质量进行双盲法评分;采用两独立样本 t 检验比较2组患者的有效辐射剂量、平均 CT 值、图像噪声、图像信噪比(SNR)、对比噪声比(CNR)、图像质量评分等,并对2组患者的阳性率以及碘摄入量进行比较。结果CTPA 共检查出肺动脉栓塞(PE)53例(A 组24例,B 组29例),A组显示 PE 的阳性率(53.33%)与 B 组(64.44%)差异均无统计学意义。2组均可以显示4~6级肺动脉分支,图像质量均符合诊断要求,主观评分的差异无统计学意义(P >0.05)。2组患者的性别、年龄和体质量指数(BMI)的差异均无统计学意义。A 组的肺动脉平均 CT 值和噪声分别高于 B 组,差异有统计学意义(P <0.01)。A 组的 SNR 和 CNR 低于 B 组,差异有统计学意义(P <0.01)。结论在80 kV 条件下应用碘克沙醇(270 mg I/mL)行 CTPA 检查,获得的图像可满足临床需求,降低了辐射剂量并减少了对比剂的摄入量。     

低浓度低剂量对比剂宝石能谱CT肺动脉成像的初步研究

目的:探讨应用低浓度、低剂量对比剂宝石能谱CT肺动脉成像的可行性.方法:60例临床拟诊为肺动脉栓塞(PE)的患者随机分成两组,每组30例,行CT肺动脉血管成像(CTPA)检查.A组为常规组,使用浓度为370 mg I/mL的对比剂碘帕醇,用量为60 mL,扫描管电压为120 kVp.B组为能谱组,使用浓度为300 mg I/mL的对比剂碘帕醇,用量为20 mL,扫描方式为能谱模式(GSI).比较常规组和能谱最佳单能量组肺动脉CT值、图像背景噪声、信噪比(SNR)、对比噪声比(CNR)、CT剂量指数(CTDIvol)、剂量长度乘积(DLP)、有效辐射剂量(ED)及图像质量主观评分的差异.结果:B组肺动脉最佳单能量图像能量水平集中在63～68 keV.能谱组(7.5g)较常规组(24.0g)所用的碘总量明显下降,两组差异有统计学意义(P＜0.05).能谱最佳单能量组图像质量与常规组CTPA相比,两者肺动脉CT值、图像噪声、SNR、CNR、DLP、ED以及主观评分之间差异均无统计学意义(P＞0.05).结论:宝石能谱CT低浓度、低剂量对比剂CTPA检查,在降低人体碘摄入量的同时,能达到与常规120 kVp结合高浓度、常规剂量对比剂相当的图像质量,且辐射剂量未增加.     

三期团注法对比剂注射方案在肺动脉CTA检查中的应用研究

目的:探讨MSCT肺动脉成像三期对比剂注射方案对于降低对比剂用量及提高检查成功率的可行性。方法:搜集在我院行肺动脉CTA检查的63例连续患者。将63例患者分成两组(三期组和两期组),三期组(30例)采用优化的对比剂注射方案,第一期注射混合液(对比剂占10%,生理盐水占90%),流率5mL/s,总量25mL;第二期注射对比剂,流率5mL/s,总量0.2～2.5mL/kg体重;第三期注射生理盐水,流率5mL/s,总量20mL。二期组(33例)采用传统对比剂注射方案,第一期注射对比剂20mL,第二期生理盐水30mL,流率均为5.5mL/s。分别测量肺动脉主干、左右肺动脉干、肺叶动脉、肺段动脉、肺亚段动脉、左右肺动脉分叉层面上腔静脉、主肺静脉及升主动脉的CT值。记录两组患者的对比剂用量。结果:两组患者肺动脉主干、上腔静脉及主动脉CT值比较差异有统计学意义(P<0.05)。对比剂平均用量三期组为(10.73±1.72)mL,二期组为20mL,三期组较二期组减少46%,差异有统计学意义(P<0.05)。结论:与传统双期注射方案比较,优化的三期对比剂注射方案可提高肺动脉CTA的检查成功率,同时降低对比剂用量。     

CT肺动脉成像评价慢性血栓栓塞性肺动脉高压栓塞指数及右心功能

目的：以选择性肺动脉造影及右心导管为标准,探讨多层螺旋计算机断层肺动脉成像（CTPA）评价慢性血栓栓塞性肺动脉高压（CTEPH）及右心功能的价值。方法：回顾性收集确诊CTEPH的患者24例,均行右心导管及肺动脉造影、CTPA及超声心动图检查。结果：CT Qanadli栓塞指数为（37.16±8.77）%,CT Mastora栓塞指数为（38.14±21.56）%,Qanadli栓塞指数高于Mastora栓塞指数（Z=-4.107,P=0.000）,且二者正相关（r=0.734,P=0.000）。CTPA测得主肺动脉/升主动脉直径比与右心导管测定肺动脉平均压（mean pulmonary arterial pressure,mPAP）正相关（r=0.461,P=0.036）。CTPA测定右心室前壁厚度与mPAP成正相关（r=0.515,P=0.018）。CTPA测得肺动脉直径大于超声测肺动脉内径（t=3.485,P=0.002）,且正相关（r=0.588,P=0.002）。CTPA测得右心室最大短轴直径大于超声测右室横径（t=2.647,P=0.016）,且正相关（r=0.429,P=0.031）。CTPA测定右室前壁厚度小于超声测值（t=3.768,P=0.001）,且成正相关（r=0.551,P=0.004）。CTPA测室间隔厚度略低于超声测室间隔厚度（t=2.941,P=0.007）,两组资料正相关（r=0.751,P=0.000）。Qanadli栓塞指数和Mastora栓塞指数与肺动脉压、主肺动脉直径、肺动脉/主动脉直径比、右室横径、右室前壁厚度等参数均无相关性（P〉0.05）。结论：CT肺动脉造影不仅能够明确诊断慢性血栓性肺栓塞,而且能够提供肺动脉树的阻塞程度、右心功能改变信息,为临床决策和治疗提供更多的信息,但慢性血栓性肺动脉高压肺栓塞程度与右心功能无关。     

Determination of height,weight, body mass index,and body surface area with a single abdominal CT image

Techniques for estimation of an individual's height, weight, body mass index (BMI), and body surface area (BSA) with a single abdominal computed tomographic (CT) image were developed. Eighty-seven abdominal CT examinations performed in adult humans were analyzed. Anatomic structures were outlined on the CT section that included L1. Multiple linear regression analysis was used to derive sex-specific predictive equations. Correlation for height was good (r > 0.65). Relationship between predicted weight and actual weight was good (r > 0.93). For BMI and BSA, r was greater than 0.893 and greater than 0.895, respectively. In this study, predictive equations for height, weight, BMI, and BSA were generated.     

非糖尿病孕妇孕期体重指数变化与新生儿出生体重的关系

目的进一步了解非糖尿病孕妇孕期体重指数变化的特点及其与新生儿出生体重的关系，旨在探讨如何监控孕妇孕期体重，从而实现对新生儿出生体重的控制。方法通过测量280例单胎初产妇的身高和妊娠各期的体重，计算体重指数（BMI），并对分娩正常体重新生儿的孕妇孕期体重指数与分娩低体重儿和巨大儿的孕妇进行比较。结果孕期体重指数随孕周的增加而增加，且与新生儿出生体重保持着恒定的正相关关系。结论如果非糖尿病孕妇孕期体重指数总增幅保持在3～5之间，就有可能分娩正常体重的新生儿。     

Factors that alter body fat, body mass, and fat-free mass in pediatric obesity

PURPOSE: The purpose of this study was to quantify the effects of exercise treatment programs on changes in body mass, fat-free mass, and body fat in obese children and adolescents. METHODS: By using the meta-analytic approach, studies that met the following criteria were included in our analyses: 1) at least six subjects per group; 2) subject groups consisting of children in the 5- to 17-yr age range; 3) pretest and posttest values for either body mass, percent body fat, or fat-free mass (FFM); 4) used exercise as a mode of treatment (e.g., walking, jogging, cycle ergometry, high-repetition resistance exercise, and combinations); 6) training programs >or= 3 wk; 7) full-length publications (not conference proceedings); 8) apparently "healthy" children (i.e., free from endocrine diseases and disorders); and 9) published studies in English language journals only. RESULTS: A total of 120 investigations were located that addressed the issue of exercise as a method of treatment in pediatric obesity. Of those, 30 met our criteria for inclusion. Across all designs and categories, fixed-effects modeling yielded significant decreases in the following dependent variables: 1) percent body fat (mean = 0.70 +/- 0.35; 95% CI = 0.21 to 1.1); 2) FFM (mean = 0.50 +/- 0.38; 95% CI = 0.03 to 0.57); 3) body mass (mean = 0.34 +/- 0.18; 95% CI = 0.01 to 0.46); 4) BMI (mean = 0.76 +/- 0.55; 95% CI = 4.24 to 1.7), and 5) VO2max (mean = 0.52 +/- 0.16; 95% CI = 0.18 to 0.89), respectively. Significant differences were found as a function of the type intervention groups (exercise vs exercise + behavioral modification; P < 0.04); body composition assessment methods (skinfold vs hydrostatic weighing, DEXA, and total body water; P < 0.006); exercise intensity (60-65%, vs >or= 71% VO2max; P < 0.01); duration ( 30 min; P < 0.03); and mode (aerobic vs aerobic + resistance training; P < 0.02). Stepwise linear regression suggested that initial body fat levels (or body mass), type of treatment intervention, exercise intensity, and exercise mode accounted for most of the variance associated with changes in body composition after training. CONCLUSIONS: Exercise is efficacious for reducing selected body composition variables in children and adolescents. The most favorable alterations in body composition occurred with 1) low-intensity, long-duration exercise; 2) aerobic exercise combined with high-repetition resistance training; and 3) exercise programs combined with a behavioral-modification component.     

Prediction accuracy of body density, lean body weight, and total body volume equations

The purpose of this study was to determine the accuracy of percent fat estimates derived from regression equations with functions of predicting body density (BD), lean body weight (LBW), and total body volume (TBV) from anthropometric variables. BD, LBW, and TBV equations were derived from the data of 95 young, adult men (percent fat X = 13.4%). The multiple correlations for these equations were: BD, 0.86-0.83; LBW, 0.96-0.95; and TBV, 0.99. The zero order correlations between laboratory determined percent fat and percent fat derived by the BD, LBW, and TBV equations ranged from 0.80 to 0.86 with standard errors from 3.1% to 3.7%. This shows that BD, LBW, and TBV equations have similar accuracy when transformed to percent fat. The derived equations were cross validated with three additional, but diverse, samples (percent fat X = 5.1%; 16.7%; 27.1%). The cross validations results revealed that all equations exhibited similar accuracy. With samples differing in percent fat, systematic prediction errors occurred. The results further confirm population specificity of prediction equations.     

孕前体质量指数及孕期增重与早产关系

目的 探讨孕前体质量指数(BMI)及孕期增重与早产的关系.方法 选取自2019年1月至2020年3月纳入"东北区域母胎-儿童-青少年队列研究"且在北部战区总医院和平院区进行规律产前检查的1350例孕妇为研究对象.按照孕前BMI将其分为低体质量组(n=146)、正常体质量组(n=926)、超重组(n=228)及肥胖组(n...     

The influence of body weight, body mass index and gender on plantar pressures: results of a cross-sectional study of healthy children's feet

The purpose of this study was to determine if plantar pressure data in 4-7 year old children with normal development: (1) required normalising by body mass and/or body mass index and (2) should be separated or pooled for boys and girls. The outcome will guide the management of plantar pressure data in future work investigating changes in plantar pressure distribution with increasing age. In a cross-sectional design, 98 British children (45 girls) with no orthopaedic, neurological or developmental disorders provided plantar pressure measurements during walking. Peak plantar pressure and plantar pressure time integrals were obtained from nine areas under the foot: calcaneus, medial and lateral midfoot, each of the five metatarsals and the hallux. Body weight and body mass index demonstrated low and weak degrees of association (r≤0.48, p<0.05) with plantar pressure data. Boys and girls showed no difference in plantar pressures (p<0.05). Plantar pressure data for 4-7 year olds does not require normalisation with body mass or body mass index, and can be pooled for boys and girls.