心血管介入手术中透视时间作为辐射剂量警示指标的可行性研究

目的以心血管介入术后采集空气比释动能(reference air kerma,AK)值和剂量面积乘积(dose-area product,DAP)值数据为依据,分析术中透视时间报警设置作为心血管介入手术辐射剂量的监测和警示工具的可行性。方法回顾性分析2016年11月至2018年1月上海长海医院736例冠状动脉造影术(CAG)和经皮冠状动脉治疗术(PCI)病例,收集术中透视时间、AK和DAP数据资料。德国西门子成像设备分组(Ceiling系统和Biplane系统)和手术类型分组(CAG和PCI),对辐射剂量数据进行比较,以及对心血管介入手术AK和DAP值与透视时间数据采用Spearman检验解析相关性。结果Ceiling和Biplane成像系统中手术透视时间为(8.9±7.8)和(8.6±7.3)min,透视AK均值和DAP均值分别为(472±474)、(510±509)mGy、(4548±4085)和(4255±3781)μGy·m^2,术中总(透视+造影)AK和DAP均值为(703±595)、(733±614)mGy、(6253±4938)和(5681±4432)μGy·m^2。CAG与PCI术中透视时间均值分别为(2.4±0.9)和(15.7±4.9)min。PCI透视辐射剂量(AK和DAP)与术中总辐射剂量比值分别为74%和78%。心血管介入手术中透视时间与AK值(r=0.822)和DAP值(r=0.844)都呈高度相关性(P<0.001)。结论透视采集辐射剂量是心血管介入手术中辐射剂量的主要来源,辐射剂量随透视时间延长而增加,透视时间监测和报警设置在心血管介入临床应用中作为术中辐射防护工具有一定的参考和警示价值。     

BLUE微剂量技术在冠状动脉造影术中的应用价值

目的 探讨BLUE微剂量技术在冠状动脉造影中的临床应用价值。方法 首先分别采用BLUE微剂量冠脉造影模式(BLUE组)和常规冠脉造影模式(常规组)对自制模体分别进行7个体位的电影采集,除采集模式不同外其余参数完全相同,利用设备自带实时辐射剂量监测系统记录对2组模体所接受的辐射剂量并进行对比分析。然后,搜集20名正常体型患者冠状动脉造影者随机分2组(BLUE组和常规组各10例),对比2组的图像质量与辐射剂量。结果 模体实验BLUE微剂量组空气比释动能(air kerma,AK值)值和剂量面积乘积(dose-area product,DAP)均低于常规组(P<0.05),辐射剂量下降35.8%～54.2%。临床研究结果显示：BLUE组与常规组冠图像质量分别为(20.80±0.42)、(20.90±0.32)分,差异无统计学意义(P>0.05); BLUE组的DAP(5.54±0.99)Gy.cm²低于常规组(11.66±3.71)Gy.cm²;BLUE组的AK值(96±15)m Gy高于对照组(189±58)mGy,差异有统计学意义(...     

不同类型心血管介入手术辐射剂量分析

目的 分析不同类型心血管介入手术患者所受X射线辐射剂量以及影响辐射剂量的因素.方法 按照甲、乙、丙3位术者的患者资料,抽取本院接受心血管介入手术的患者442例,包括单行冠状动脉造影术(CAG)、冠状动脉介入术(PCI)、射频消融术(RFCA)、先天性心脏病介入术(CHD)和永久性心脏起搏器植入术(PCPI).采集患者的皮肤表面累积入射剂量(CD)、剂量面积乘积(DAP)、透视时间.结果 CAG、PCI、RFCA、CHD、PCPI各组患者的CD值分别为(0.34 ±0.23)、(1.33±0.76)、(0.71±0.43)、(0.27±0.22)和(0.92±0.42) Gy,DAP值分别为(34.18±23.33)、( 135.92±81.14)、( 79.79±50.66)、(27.93±23.66)和(94.60±48.11) Gy.cm2.透视时间分别为(4.82±3.73)、(16.64±9.01)、(17.04±15.29)、(9.60±5.97)和(7.31±6.45) min.DAP值与透视时间呈高度相关性(r =0.84,P＜0.05).结论 不同类型心血管介入手术患者所受的平均辐射剂量不同.辐射剂量和透视时间与手术难易度和术者操作熟练程度有关,可通过提高操作技术水平、减少透视时间降低患者辐射剂量.     

动态路图在冠状动脉低剂量模式中的应用

目的评估联合应用动态冠状动脉路图（dynamic coronary roadmap,DCR）技术及低剂量冠脉模式是否可以进一步降低总放射剂量、透视时间和对比剂用量。方法 纳入2022年7月至2022年12月在上海市同济医院行冠脉造影患者94例,随机分为DCR组53例,对照组41例。DCR组应用冠状动脉动态路图指导行经皮冠状动脉介入（PCI）术,对照组采用低剂量冠脉造影模式进行手术。比较两组的总空气比释动能（air kerma,AK）、剂量面积乘积（DAP）、术中透视时间、对比剂用量。结果 与对照组相比,DCR组的AK明显减低,为（597.9±222.8） mGy比（717.0±326.8） mGy(P=0.039);DAP也显著减少,为（33.2±13.3） Gycm2/s比（41.3±21.5） Gycm2/s(P=0.027);DCR组的透视时间少于对照组,为（9.8±3.3） min比（12.1±4.3） min(P<0.01);两组对比剂用量无明显差异,为（122.3±19.0） mL比（130.5±28.5） mL(P=0.116)。结论 在低剂量冠脉介入治疗中应用动态...     

蒙特卡罗方法评估冠状动脉介入术中患者器官剂量的转换系数

目的通过蒙特卡罗方法模拟计算剂量面积乘积(DAP)致相关器官吸收剂量的转换系数, 从而为评估冠状动脉介入术中患者的器官剂量提供便利。方法使用Geant4蒙特卡罗软件构建人体和辐射场模型, 模拟计算并得到器官吸收剂量转换系数。结果在冠状动脉造影(CAG)中, 肺、骨髓、肝脏、心脏的转换系数, 男性分别为(0.283 ± 0.068)、(0.169± 0.049)、(0.110 ± 0.077)、(0.080 ± 0.032)mGy/(Gy·cm2), 女性分别为(0.376 ± 0.121)、(0.192 ± 0.056)、(0.153 ± 0.105)、(0.102 ± 0.033)mGy/(Gy·cm2), 与经皮冠脉介入治疗(PCI)中对应器官的转换系数相近。不同介入术的DAP差异具有统计学意义(t=-6.012, P<0.05)。性别组间的DAP差异没有统计学意义(P>0.05)。结论器官吸收剂量的转换系数在同一性别组内与冠状动脉造影和经皮介入治疗的相关性较小, 但同一术组中女性的剂量转换系数通常高于男性。蒙特卡罗方法计算的剂量面积乘积(DAP)致器官吸收剂量的转换系...     

三维DSA彩色融合技术在大脑中动脉远端血管介入术中导航定位的应用

目的 评价三维DSA彩色融合技术在大脑中动脉远端血管介入术中导航定位的价值。方法 选取2018年6月至2020年12月在西南医科大学附属医院接受大脑中动脉远端动静脉畸形和动脉瘤介入治疗患者36例。随机将患者分为实验组（n=17,术中采用三维DSA彩色融合技术辅助导航）和对照组（n=19,采用二维路径图导航）。观察两组手术时间、术中微导管超选病变血管导引时间、X线透视时间、对比剂用量、辐射剂量[空气比释动能（AK）、剂量-面积乘积（DAP）]、手术相关并发症等情况。结果 实验组、对照组间手术时间[（95.80±12.50） min比（103.70±9.60） min]、微导管导引时间[（5.82±1.94） min比（8.47±2.48） min]、X线透视时间[（35.76±4.72） s比（51.16±5.80） s]、对比剂用量[（27.06±2.77） mL比（33.05±5.46） mL]、辐射剂量[AK:(88.48±21.67) mGy比（234.99±40.60） mGy,DAP:(7.11±1.07) Gyc/m2比（13.40±3.34） Gyc/m2,]差异有统计学...     

主动脉瘤血管内治疗中影像学设备对于病人辐射剂量的影响

目的采用移动透视C臂、移动血管造影机和固定血管造影机等不同的影像学设备,比较病人在进行主动脉瘤血管内治疗(EVAR)中的辐射剂量。材料与方法回顾研究3.5年时间内147例病人所进行的153次EVAR操作的剂量面积乘积(DAP)。根据这些数据,计算入射表面剂量(ESD)和有效剂量(ED)。使用透视C臂、移动和固定血管造影机的例数分别为79、26和48例。结果所有设备所采用的透视时间基本上相同,为15～19min。不同系统间的临床转归没有显著差异。不同影像设备间,DAP[移动C臂:(32±20)Gy.cm2;移动血管机:(362±164)Gy.cm2;固定血管机:(464±274)Gy.cm2;P<10-6]、ESD(移动C臂:(0.18±0.11)Gy;移动血管机:(2.0±0.8)Gy;固定血管机:(2.5±1.5)Gy;P<10-6)和ED[移动C臂:(6.2±4.5)mSv;移动血管机:(64±26)mSv;固定血管机:(129±76)mSv;P<10-6]差异具有统计学意义。结论采用现代便携式C臂进行EVAR时的辐射剂量远小于专用的固定或移动血管造影机。     

肝动脉化疗栓塞治疗肝癌患者的X射线辐射评价

目的　研究经肝动脉化疗栓塞 (THACE)治疗肝癌过程中 ,患者受到的X射线辐射 ,为THACE放射防护提供依据。方法　回顾性分析 82例HCC患者的辐射剂量资料 ,DSA机 (Angiostar Plus)配置穿透电离室型剂量监测系统 (DiamentorK1andDiamentorED) ,在线读取面积剂量乘积DAP(cGy cm2 )和入射表面剂量ESD(mGy) ,采用Monte Carlo转换因子估算有效剂量ED(mSv)。并分析近期 10例THACE患者 ,在提高基值管电压、减低透视脉冲频率和摄影帧数下对辐射剂量的影响。结果　 82例HCC患者透视时间 (35 3± 2 1 1)min ,摄影 (2 34± 10 8)帧 ,DAP为 (2 174 8± 12 4 2 4 )cGy cm2 ,ESD为 (96 4± 6 32 )mGy ,ED为 (34 8± 19 9)mSv。透视对总DAP的贡献 (2 4 0± 12 7) %小于摄影 (75 9± 12 7) % ,透视对ESD值的贡献 (4 9 8± 14 9) % ,与摄影相似 (5 1 6± 14 2 ) %。近期的 10例THACE患者的每分钟透视剂量、每帧摄影剂量及总剂量都比HCC患者明显降低。结论　在THACE过程中患者受到一次性较大剂量X射线照射。适度提高基值管电压、减低透视脉冲频率和缩减摄影帧数 ,可以有效降低患者的辐射剂量     

子宫肌瘤患者子宫动脉栓塞过程中的X线辐射研究

目的研究子宫肌瘤患者在子宫动脉栓塞(UAE)术中所经受的X射线照射及降低辐射的方法。方法回顾性分析早期90例和近期10例UAE辐射剂量资料,采用DSA机(AngiostarPlus)配置的穿透电离室型剂量监测系统(DiamentorKI和DiamentorED),在线读取面积剂量乘积(DAP)(cGy·cm2)和入射表面剂量(ESD)(mGy)。结果早期90例UAE透视时间(28.60±23.73)min,摄影(87±38)帧,DAP均值(6178±3802)cGy·cm2,ESD均值(378±245)mGy。近期10例UAE透视时间(19.80±7.18)min,摄影(83±13)帧,DAP均值(1722±342)cGy·cm2,ESD均值(121±32)mGy。透视剂量率均值约为早期的1/2,图像采集剂量率均值约为早期的1/4。结论缩短透视时间与减少透视剂量率、减少图像采集帧数与图像采集剂量率,是降低UAE治疗过程中患者X射线辐射的有效方法。     

野战方舱内冠状动脉造影投照体位对辐射剂量和影像质量的影响

目的 探讨野战综合手术救治方舱内施行冠状动脉(冠脉)造影中不同的投照体位对患者辐射剂量和影像质量的影响,为剂量优化提出建议.方法 用标准体模测定冠脉造影9个不同投照体位下图像清晰时剂量面积乘积(DAP)和入射表面剂量(ESD)透视和摄影的辐射剂量值;并在方舱内对6只实验动物施行9个不同投照体位下的冠脉造影,观察比较不同体位的影像质量.结果 不同投照体位下,透视时DAP剂量范围值为12.96 ～ 31.28 μGym2/s,ESD透视范围为21 403.33～71 106.67 μGy/S;摄影时DAP剂量范围值为39.55～87.59 μGy/s(10帧),ESD剂量范围值为67 647.25～ 212 498.54 μGy(10帧).正位剂量值最小,脾位最大,其他体位与正位相比差异均有统计学意义(P＜ 0.05);不同体位影像质量平均评分值范围为3.55 ～ 3.85,正位影像质量最好,脾位最差,其他体位与正位相比差异均有统计学意义(P＜0.05).结论 不同投照体位,辐射剂量、影像质量不同.手术过程中应根据手术需要,合理选择投照体位以期既能保证图像质量又能减少患者受照剂量.     

Radiation doses in interventional radiology procedures: the RAD-IR study: part I: overall measures of dose

PURPOSE: To determine patient radiation doses for interventional radiology and neuroradiology procedures, to identify procedures associated with higher radiation doses, and to determine the effects of various parameters on patient doses. MATERIALS AND METHODS: A prospective observational study was performed at seven academic medical centers. Each site contributed demographic and radiation dose data for subjects undergoing specific procedures in fluoroscopic suites equipped with built-in cumulative dose (CD) and dose-area-product (DAP) measurement capability compliant with International Electrotechnical Commission standard 60601-2-43. The accuracy of the dosimetry was confirmed by comprehensive measurements and by frequent consistency checks performed over the course of the study. RESULTS: Data were collected on 2,142 instances of interventional radiology procedures, 48 comprehensive physics evaluations, and 581 periodic consistency checks from the 12 fluoroscopic units in the study. There were wide variations in dose and statistically significant differences in fluoroscopy time, number of images, DAP, and CD for different instances of the same procedure, depending on the nature of the lesion, its anatomic location, and the complexity of the procedure. For the 2,142 instances, observed CD and DAP correlate well overall (r = 0.83, P <.000001), but correlation in individual instances is poor. The same is true for the correlation between fluoroscopy time and CD (r = 0.79, P <.000001). The correlation between fluoroscopy time and DAP (r = 0.60, P <.000001) is not as good. In 6% of instances (128 of 2,142), which were principally embolization procedures, transjugular intrahepatic portosystemic shunt (TIPS) procedures, and renal/visceral artery stent placements, CD was greater than 5 Gy. CONCLUSIONS: Most procedures studied can result in clinically significant radiation dose to the patient, even when performed by trained operators with use of dose-reducing technology and modern fluoroscopic equipment. Embolization procedures, TIPS creation, and renal/visceral artery stent placement are associated with a substantial likelihood of clinically significant patient dose. At minimum, patient dose data should be recorded in the medical record for these three types of procedures. These data should include indicators of the risk of deterministic effects as well as the risk of stochastic effects.     

Patient radiation doses and references levels in interventional radiology

PURPOSE: To set Diagnostic Reference Levels (DRLs) in interventional radiology by means of dose area product (DAP) measurements and the grouping of homogeneous procedures, and to quantify the associated errors in the DRL estimates. To evaluate the Mean Effective Doses per single procedure. MATERIALS AND METHODS: Interventional radiology procedures were divided into four main groups: neuroradiological, vascular, extravascular and paediatric. Neuroradiological and vascular procedures were further divided into diagnostic and interventional procedures. Starting from DAP and total fluoroscopy time measurements in 1,256 patients, the DRLs were determined for 17 procedures, together with an estimate of their uncertainty. The correlation between fluoroscopy time and DAP was assessed. Mean effective dose estimates were obtained from measured DAP values and from the analysis of the dosimetric data reported in the literature for similar procedures. RESULTS: The main features of DAP distributions are long high-dose tails, indicating asymmetric distributions, together with a large interquartile range. Rounded third-quartile values of DAP distributions showed a large range in the procedures taken into consideration. Values of 147, 198, 338 Gy cm(2)were obtained for supra-aortic angiography, cerebral angiography and embolization. Values of 86-101 and 459-438 Gy cm(2)were obtained for diagnostic and interventional vascular procedures on the lower limbs and on the abdomen, respectively. Values of 25-33 Gy cm(2)were obtained for retrograde cystourethrographies and ERCP, and values of 62-158 Gy cm(2)were obtained for nephrostomy and percutaneous transhepatic cholangiography. The correlation between total fluoroscopy time and the DAP values was poor. Mean effective dose estimates showed lower values for extravascular procedures (4.8-28.2 mSv), intermediate values for neuroradiological procedures (12.6-32.9 mSv) and higher values for vascular procedures involving the abdomen (36.5-86.8 mSv). DISCUSSION: DAP values were generally higher in vascular than in extravascular procedures. In generally, interventional vascular procedures show higher DAP values than the corresponding diagnostic procedures, with the exception of the abdominal region where the values were similar. Extravascular procedures with percutaneous access show significantly higher DAP values than those with endoscopic access. Total fluoroscopy time is a poor predictor of patient doses in interventional radiology. CONCLUSIONS: The systematic recording of DAP values, together with adequate grouping of similar procedures makes it possible to establish stable DRLs on a local basis and to carry out dosimetric evaluations, although on a statistical rather than individual basis. Patient radiation doses during interventional radiological procedures may be high, particularly when the abdominal region is involved.     

Diagnostic reference levels and effective dose in paediatric cardiac catheterization

European states within the EEC are required to establish and use diagnostic reference levels (DRLs) in X-ray examinations. However, up to now there have been no DRLs for cardiac catheterization in children, nor as a rule is the effective dose estimated. We have evaluated the dose-area products (DAPs) for three different types of angiocardiography systems over a time span of 8 years. For each system DAP increased in proportion to the body weight (BW) over two orders of magnitude. The proportionality constant decreased over the years. To reduce the broad distribution of DAP the doses for cine acquisition (DAPA) and fluoroscopy (DAPF) were indexed with respect to the total numbers of acquired images (AN) and the total times of fluoroscopy (FT). DAPA/AN is directly proportional to BW with a high correlation (r = 0.896, n = 1346). Likewise, DAPF/FT is proportional to BW from 0.1 kg to 100 kg (r = 0.84, n = 2138). Therefore, by normalizing DAP to BW the growth dependent variation of DAP can be eliminated. There are numerous short examinations with very small total DAPs, which were separated from the group of diagnostic examinations. The mean DAP/BW of this group is 0.41 Gycm2 kg(-1) (90th percentile: 0.81 Gycm2 kg(-1), n = 1106). For interventional procedures in congenital heart diseases DAP/BW is significantly higher (p<0.001) (mean: 0.56 Gycm2 kg(-1), 90th percentile: 1.16 Gycm2 kg(-1), n = 883). There are significant differences between different types of interventional procedures, the mean values being between 0.35 Gycm2 kg(-1) (occlusion of patent ductus botalli, n = 165) and 1.30 Gycm2 kg(-1) (occlusion of ventricular septal defect, n = 32). For patients who are catheterized several times over the years, the cumulative effective dose (E) may reach high values, being especially high for patients with hypoplastic left heart syndrome (typically 11 mSv). E is derived from DAP/BW by use of a constant DAP/BW to E conversion factor, independent of the age of the patient. DAP/BW is appropriate to describe paediatric DRLs and is recommended instead of using mean DAP values for age groups.     

用胶片法对心脏介入程序中患者峰值皮肤剂量测量研究

目的 采用胶片法对进行心血管介入手术中患者所受峰值皮肤剂量（PSD）进行测量研究,包括冠状动脉血管造影术（CA）和经皮穿刺腔内冠状动脉成形术（PTCA）。方法 选用Gafchromic XR-RV3胶片在两家医院进行患者峰值皮肤剂量的测量。手术时将胶片放在患者身下的诊视床上。记录手术中监视器上显示的kV、mA、透视时间、剂量面积乘积（DAP）、参考点累积剂量等相关信息。采用Epson V750平板扫描仪对胶片进行分析扫描及分析,选用FilmQA软件分别测量图像的红、绿、蓝三色通道的像素值,使用红通道数据计算患者的 PSD。对PSD与设备显示参数进行相关分析,对相关的变量进行多元线性回归分析。结果 共测量CA手术26例,CA+PTCA手术19例。CA手术中,透视时间最高为17.62 min,累积剂量和DAP最大分别为1 498.50 mGy和109.68 Gy ·cm²,PSD最大为361.20 mGy。CA+PTCA手术中,曝光时间最长为64.48 min,累积剂量和DAP最大分别为6 976.20 mGy和5 336.00 Gy ·cm²,17例患者的PSD在1 Gy以内,1例患者PSD在1~2 Gy之间,1例患者PSD超出了发生皮肤损伤2 Gy的阈值,达到了2 195.70 mGy。CA程序中,患者PSD与DAP相关（R²=0.815,P<0.05）,CA+PTCA程序中,患者PSD与累积剂量相关（R²=0.916,P<0.05）。结论 心脏介入放射学程序中部分患者的PSD会超出ICRP建议的发生皮肤确定性效应的2 Gy阈值。DSA设备上显示的剂量相关的参数,只能粗略估算患者PSD的大小。使用XR-RV3胶片精确测量介入手术中患者的峰值皮肤剂量是一种非常快捷、有效的方法。     

A study on maximum skin dose in cerebral embolization procedures

BACKGROUND AND PURPOSE: It is essential to measure the skin dose of radiation received by patients during interventional neuroradiologic procedures performed under fluoroscopic guidance, such as embolization of cerebral aneurysms, which is regarded as a high-dose interventional radiology procedure. In this study, we report a method for evaluating maximum skin dose (MSD), an ideal marker of radiation-induced effects, based on an innovative use of radiochromic films. MATERIALS AND METHODS: Forty-eight procedures were studied in 42 patients undergoing embolization of cerebral aneurysms. Fluoroscopic and digital dose-area product (DAP), fluoroscopy time, and total number of acquired images were recorded for all procedures. The MSD was measured using Gafchromic XR type R films. RESULTS: The MSD was measured in one group of 21 procedures. The coefficient (kappa) of the interpolation line between the skin dose and the DAP (kappa = 0.0029 cm(-2)) was determined. An approximate value of MSD from the DAP for the remaining 27 procedures was estimated by means of an interpolation line. The mean MSD was found to be 1.16 Gy (range, 0.23-3.20 Gy). CONCLUSION: The use of radiochromic XR type R films was shown to be an effective method for measuring MSD. These films have the advantage of supplying information on both the maximum dose and the distribution of the dose: this satisfies the most stringent interpretation of Food and Drug Administration, American College of Radiology, and international recommendations for recording skin dose.     

Comparison of four techniques to estimate radiation dose to skin during angiographic and interventional radiology procedures

PURPOSE: Four techniques used to estimate radiation risk were compared to determine whether commonly used dosimetry measurements permit reliable estimates of skin dose. Peak skin dose (PSD) is known to be the most reliable estimate of risk to skin. The purpose of this study is to determine peak skin dose with use of real-time software measurements and to correlate other measures of dose with PSD. MATERIALS AND METHODS: Two hundred twelve patients undergoing arch aortography and bilateral carotid arteriography (referred to as "carotid"), abdominal aortography and bilateral lower extremity runoff ("runoff"), or tunneled chest wall port placement ("port") were studied. Fluoroscopy time, dose-area product (DAP), and cumulative dose at the interventional reference point were recorded for all procedures; PSD was recorded for a subset of 105 procedures. The dose index, defined as the ratio between PSD and cumulative dose, was also determined. RESULTS: In general, correlation values for comparisons between fluoroscopy time and the other measures of dose (r =.29 to.78) were lower than values for comparisons among DAP, cumulative dose, and PSD (r =.52 to.94). For all procedures, pair-wise correlations between DAP, cumulative skin dose, and PSD were statistically significant (P <.01) The ratio between PSD and cumulative skin dose (dose index) was significantly different for ports versus other procedures (carotid, Z = 4.62, P <.001; runoff, Z = 4.52, P <.001), but carotid and runoff procedures did not differ significantly in this regard (Z = 0.746, P =.22). Within each individual procedure type, the range of values for the dose index varied 156.7-fold for carotid arteriography, 3.2-fold for chest ports, and 175-fold for aortography and runoff. CONCLUSION: Fluoroscopy time is a poor predictor of risk because it does not correlate well with PSD. Cumulative dose and DAP are not good analogues of PSD because of weak correlations for some procedures and because of wide variations in the dose index for all procedures.     

Main clinical, therapeutic and technical factors related to patient's maximum skin dose in interventional cardiology procedures

Objective: The study aimed to characterise the factors related to the X-ray dose delivered to the patient's skin during interventional cardiology procedures. Methods: We studied 177 coronary angiographies (CAs) and/or percutaneous transluminal coronary angioplasties (PTCAs) carried out in a French clinic on the same radiography table. The clinical and therapeutic characteristics, and the technical parameters of the procedures, were collected. The dose area product (DAP) and the maximum skin dose (MSD) were measured by an ionisation chamber (Diamentor; Philips, Amsterdam, The Netherlands) and radiosensitive film (Gafchromic; International Specialty Products Advanced Materials Group, Wayne, NJ). Multivariate analyses were used to assess the effects of the factors of interest on dose. Results: The mean MSD and DAP were respectively 389 mGy and 65 Gy cm(-2) for CAs, and 916 mGy and 69 Gy cm(-2) for PTCAs. For 8% of the procedures, the MSD exceeded 2 Gy. Although a linear relationship between the MSD and the DAP was observed for CAs (r=0.93), a simple extrapolation of such a model to PTCAs would lead to an inadequate assessment of the risk, especially for the highest dose values. For PTCAs, the body mass index, the therapeutic complexity, the fluoroscopy time and the number of cine frames were independent explanatory factors of the MSD, whoever the practitioner was. Moreover, the effect of technical factors such as collimation, cinematography settings and X-ray tube orientations on the DAP was shown. Conclusion: Optimising the technical options for interventional procedures and training staff on radiation protection might notably reduce the dose and ultimately avoid patient skin lesions.     

Factors influencing fluoroscopy time and dose-area product values during ad hoc one-vessel percutaneous coronary angioplasty

X-ray exposure during radiologically guided interventional procedures may have some deleterious effects. The aim of our study was to analyse the factors affecting patient dose during percutaneous coronary angioplasty (PTCA). We evaluated radiation dose during coronary angiography followed by one-vessel PTCA in 402 consecutive patients who were treated by three experienced physicians using both femoral and radial techniques. Fluoroscopy time (t) and patient dose measured by a dose-area product (DAP) meter were recorded. A good correlation was observed between t and the DAP (r=0.78, p<0.001). To assess the factors affecting radiation exposure, we studied the differences between operators, arterial catheterization access and stenting strategy. Median (25th to 75th percentiles) values for t were 19 (13 to 26) min and for DAP were 191 (145 to 256) Gy cm(2) for operator 3 compared with t=12 (9 to 18) min and DAP=137 (91 to 208) Gy cm(2) for operator 2 (p<0.005 versus operator 3) and t=13 (9 to 17) min, and DAP=134 (93 to 190) Gy cm(2) for operator 1 (p<0.001 versus operator 3). Differences between the radial and the femoral techniques were: t=17 (13 to 24) min versus 12 (8 to 17) min, (p<0.001) and DAP=175 (128 to 246) Gy cm(2) versus 138 (93 to 197) Gy cm(2), (p<0.001). In comparison with stenting without pre-dilation, direct stenting significantly reduced t and DAP [t=12 (9 to 16) min versus 16 (11 to 22) min, (p<0.001) and DAP=130 (95 to 186) Gy cm(2) versus 163 (119 to 230) Gy cm(2), respectively, (p<0.01)]. Radiation exposure to patients and staff are strongly dependent on operators, stenting strategy and the arterial access chosen for ad hoc one-vessel PTCA.     

Radiation Exposure in Nonvascular Fluoroscopy-Guided Interventional Procedures

Purpose

To investigate the radiation exposure in non-vascular fluoroscopy guided interventions and to search strategies for dose reduction.

Materials and Methods

Dose area product (DAP) of 638 consecutive non-vascular interventional procedures of one year were analyzed with respect to different types of interventions; gastrointestinal tract, biliary interventions, embolizations of tumors and hemorrhage. Data was analyzed with special focus on the fluoroscopy doses and frame doses. The third quartiles (Q3) of fluoroscopy dose values were defined in order to set a reference value for our in-hospital practice.

Results

Mean fluoroscopy times of gastrostomy, jejunostomy, right and left sided percutaneous biliary drainage, chemoembolization of the liver and embolization due to various hemorrhages were 5.9, 8.6, 13.5, 16.6, 17.4 and 25.2 min, respectively. The respective Q3 total DAP were 52.9, 73.3, 155.1, 308.4, 428.6 and 529.3 Gy*cm². Overall, around 66% of the total DAP originated from the radiographic frames with only 34% of the total DAP applied by fluoroscopy (P < 0.001). The investigators experience had no significant impact on the total DAP applied, most likely since there was no stratification to intervention-complexity.

Conclusion

To establish Diagnostic Reference Levels (DRLs), there is a need to establish a registry of radiation dose data for the most commonly performed procedures. Documentation of interventional procedures by fluoroscopy “grabbing” has the potential to considerably reduce radiation dose applied and should be used instead of radiographic frames whenever possible.