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。     

Radiation exposure and patient experience during percutaneous coronary intervention using radial and femoral artery access

The aim of this study was to evaluate radiation dose and patient discomfort/pain in radial artery access vs femoral artery access in percutaneous coronary intervention (PCI). Dose–area product (DAP) was measured non-randomised for 114 procedures using femoral access and for 55 using radial access. The patients also responded to a questionnaire concerning discomfort and pain during and after the procedure. The mean DAP was 69.8 Gy cm² using femoral access and 70.5 Gy cm² using radial access. Separating the access site from confounding factors with a multiple regression, there was a 13% reduction in DAP when using radial access (p=0.038). Procedure times did not differ (p=0.81). Bed confinement was much longer in the femoral access group (448 vs 76 min, p=0.000). With femoral access, there was a significantly higher patient grading for chest (p=0.001) and back pain (p=0.003) during the procedure and for access site (p=0.000) and back pain (p=0.000) after the procedure. Thirty-two femoral access patients (28%) were given morphine-type analgesics in the post-procedure period compared to three radial access patients (5%, p=0.001). DAP does not increase when using radial instead of femoral access and the patients grade discomfort and pain much lower when using radial access. Radial access is thus beneficial to use.     

Preliminary reference levels in interventional cardiology

This article describes the European DIMOND approach to defining reference levels (RLs) for radiation doses delivered to patients during two types of invasive cardiology procedures, namely coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA). Representative centres of six European countries recorded patients' doses in terms of dose-area product (DAP), fluoroscopy time and number of radiographic exposures, using X-ray equipment that has been subject to constancy testing. In addition, a DAP trigger level for cardiac procedures which should alert the operator to possible skin injury, was set to 300 Gy×cm². The estimation of maximum skin dose was recommended in the event that a DAP trigger level was likely to be exceeded. The proposed RLs for CA and PTCA were for DAP 45 Gy×cm² and 75 Gy×cm², for fluoroscopy time 7.5 min and 17 min and for number of frames 1250 and 1300, respectively. The proposed RLs should be considered as a first approach to help in the optimisation of these procedures. More studies are required to establish certain "tolerances" from the proposed levels taking into account the complexity of the procedure and the patient's size.     

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.     

How to set up and apply reference levels in fluoroscopy at a national level

A nationwide survey was launched to investigate the use of fluoroscopy and establish national reference levels (RL) for dose-intensive procedures. The 2-year investigation covered five radiology and nine cardiology departments in public hospitals and private clinics, and focused on 12 examination types: 6 diagnostic and 6 interventional. A total of 1,000 examinations was registered. Information including the fluoroscopy time (T), the number of frames (N) and the dose-area product (DAP) was provided. The data set was used to establish the distributions of T, N and the DAP and the associated RL values. The examinations were pooled to improve the statistics. A wide variation in dose and image quality in fixed geometry was observed. As an example, the skin dose rate for abdominal examinations varied in the range of 10 to 45 mGy/min for comparable image quality. A wide variability was found for several types of examinations, mainly complex ones. DAP RLs of 210, 125, 80, 240, 440 and 110 Gy cm² were established for lower limb and iliac angiography, cerebral angiography, coronary angiography, biliary drainage and stenting, cerebral embolization and PTCA, respectively. The RL values established are compared to the data published in the literature.     

Radiation dose optimization in coronary angiography and percutaneous coronary intervention (PCI). II. Clinical evaluation

In a previous part of this study, the fluoroscopy dose rate was reduced in a cardiac catheterization laboratory. The objectives of the present study were to evaluate the effects in a clinical population undergoing percutaneous coronary intervention (PCI) of the dose-reducing measures detailed previously. Kerma area-product (KAP) values were first recorded for 154 patients undergoing PCI. Then, the fluoroscopy KAP rate was reduced from 44 to 16 mGy cm²/s by increasing filtration and reducing the image intensifier dose request. After this optimization, KAP was recorded for another 138 PCI procedures. After adjustment for differing proportions of combined procedures (coronary angiography+PCI), the total KAP was reduced to 67% of the original value with a 95% confidence interval from 57 to 78%, statistically significant. The mean total KAP values were 93.6 Gy cm² before and 69.1 Gy cm² after optimization. The KAP for digital acquisition did not change significantly. It is possible to make a large dose reduction in PCI by reducing the fluoroscopy dose rate. This dose reduction is beneficial for both patients and staff. Electronic Publication     

心血管病介入操作时患者受照剂量研究

目的 对心血管介入手术中患者所受辐射剂量及与辐射剂量相关的指标进行采集和分析,为改善患者的辐射防护提供依据.方法 对在省属三级甲等医院进行的26例完整的心血管介入手术的患者进行临床数据采集,按手术类别分成冠状动脉血管造影术(CA)及行冠状动脉血管造影术(CA)后继续行经皮穿刺腔内冠状动脉成形术(PTCA)两组,采用TLD个人剂量计照射野矩阵测量法,检测患者荧光照射时间、入射皮肤剂量(ESD)、最高皮肤剂量(PSD)、剂量-面积乘积(DAP)等指标,用TLD测量在模拟心血管手术条件下体模器官剂量.结果 荧光透视时间为(17.7±15.6)min,范围为0.80～42.4 min;ESD范围为(159±138)mGy,4.40～459 mGy;PSD范围为(769±705)mGy,22.6～2.43×103mGy.CA+PTCA组的荧光照射时间、ESD、PSD均大于CA组,差异有统计学意义.最大皮肤受照剂量与透视时间有较好的相关性(r=0.84,P＜0.01).结论 心血管病放射性介入操作时,可通过透视时间来估算最大皮肤受照剂量.

Abstract：

Objective To collect and analyze the radiation dose to patients in cardiovascular interventional procedures and the radiation dose-related indicators,in order to provide a basis for improving radiation protection of patients.MethodsThe clinical data of 26 cases of complete cardiovascular interventional procedures was collected in the municipal Grade A Class Three hospitals,including coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA),and the patient-received radiation doses and other related factors was studied.TLD personal dosimeter radiation field matrix method was used to measure fluorescence time,the entrance skin dose (ESD),the peak skin dose (PSD),dosearea product (DAP) and other indicators.TLD was used to measure the organ dose of the phantom under the cardiovascular interventional procedure condition.ResultsThe fluoroscopy time was (17.7 ±15.6) min during the range of 0.80-42.4 min.The average entrance skin dose (ESD) was (159 ± 138)mGy during the range of 4.40-459 mGy.The peak skin dose (PSD) was (769 ± 705) mGy during the range of 22.6 - 2.43 × 103mGy.The fluorescence time,entrance skin dose (ESD) ,peak skin dose (PSD) of the group CA + PTCA are greater than the group CA and the difference has statistical significan.The peak skin dose and the fluoroscopy time have good linear correlation (r = 0.84,P ＜ 0.01 ).Conclusion The peak skin dose the patient received in cardiovascular interventional radiological operation can be estimated through the fluoroscopy time.     

Kodak EDR2 film for patient skin dose assessment in cardiac catheterization procedures

Patient skin doses were measured using Kodak EDR2 film for 20 coronary angiography (CA) and 32 percutaneous transluminal coronary angioplasty (PTCA) procedures. For CA, all skin doses were well below 1 Gy. However, 23% of PTCA patients received skin doses of 1 Gy or more. Dose-area product (DAP) was also recorded and was found to be an inadequate indicator of maximum skin dose. Practical compliance with ICRP recommendations requires a robust method for skin dosimetry that is more accurate than DAP and is applicable over a wider dose range than EDR2 film.     

Comparison of Patient Dose in Two-Dimensional Carotid Arteriography and Three-Dimensional Rotational Angiography

Background and Purpose It is known that interventional neuroradiology (IN) involves high radiation dose to both patients and staff even if performed by trained operators using modern fluoroscopic X-ray equipment and dose-reducing technology. Therefore, every new technology or imaging tool introduced, such as three-dimensional rotational angiography (3D RA), should be evaluated in terms of radiation dose. 3D RA requires a series with a large number of images in comparison with 2D angiography and it is sometimes considered a high-dose IN procedure. The literature is scarce on the 3D RA radiation dose and in particular there are no data on carotid arteriography (CA). The aim of this study was to investigate patient dose differences between 2D and 3D CA. Methods The study included 35 patients undergoing 2D CA in hospital 1 and 25 patients undergoing 3D CA in hospital 2. Patient technical data collection included information on the kerma area product (KAP), fluoroscopy time (T), total number of series (S), and total number of acquired images (F). Results Median KAP was 112 Gy cm² and 41 Gy cm² for hospitals 1 and 2, respectively, median T was 8.2 min and 5.1 min, median S was 13 and 4, and median F was 247 and 242. Entrance surface air-kerma rate, as measured in “medium” fluoroscopy mode measured in 2D acquisition using a 20 cm phantom of polymethylmethacrylate, was 17.3 mGy/min for hospital 1 and 9.2 mGy/min for hospital 2. Conclusion 3D CA allows a substantial reduction in patient radiation dose compared with 2D CA, while providing the necessary diagnostic information.     

Radiation Dose in Prostatic Artery Embolization Using Cone-Beam CT and 3D Roadmap Software

PurposeTo evaluate the radiation dose in patients undergoing prostatic artery embolization (PAE) using cone-beam CT and 3-dimensional (3D) guidance software.Materials and MethodsIn this single-center retrospective study, 100 patients with benign prostatic hyperplasia (mean prostate volume, 83.6 mL ± 44.2; 69.4 ± 9.6 years of age; body mass index, 26.5 ± 4.2) were treated using PAE between October 2016 and April 2018. Informed consent was obtained from all participants included in the study. All patients received at least 1 intraprocedural cone-beam CT per side for evaluation of the vessel anatomy and software rendering of 3D guidance for catheter guidance. Digital subtraction angiography (DSA) was performed in the distal branches only. The total dose area product (DAP), along with the DAP attributed to fluoroscopy, DSA, and cone-beam CT, were assessed.ResultsBilateral embolization was achieved in 83 patients (83%). The average total DAP was 134.4 Gy ⋅ cm² ± 69.5 (range, 44.7–410.9 Gy ⋅ cm²). Fluoroscopy, DSA, and cone-beam CT accounted for 35.5 Gy ⋅ cm² ± 21.3 (range, 8.6–148.6 Gy ⋅ cm²) or 26.4% (percentage of total DAP), 58.2 Gy ⋅ cm² ± 48.3 (range, 10.3–309.3 Gy ⋅ cm²) or 43.3%, and 40.7 Gy ⋅ cm² ± 14.5 (range, 15.9–86.3 Gy ⋅ cm²) or 30.3%, respectively. Average procedure time was 89.4 ± 27.0 minutes, and the average fluoroscopy time was 30.9 ± 12.2 minutes.ConclusionsIntraprocedural cone-beam CT in combination with 3D guidance software allows for identification and catheterization of the prostatic artery in PAE. Furthermore, the results of this trial indicate that this study protocol may lead to a low overall radiation dose.     

Does digital flat detector technology tip the scale towards better image quality or reduced patient dose in interventional cardiology?

As dynamic flat-panel detectors (FD) are introduced in interventional cardiology (IC), the relation between patient dose and image quality (IQ) needs to be reconsidered for this type of image receptor. On one hand this study investigates IQ of a FD system by means of a threshold contrast-detail analysis and compares it to an image intensifier (II) system on a similar X-ray setup. On the other hand patient dose for coronary angiography (CA) procedures on both systems is compared by Dose-Area Product (DAP)-registration of a patient population. The comparative IQ study was performed for a range of entrance dose rates (EDR) covering the fluoroscopy and cinegraphy working mode. In addition the IQ investigation was extended to a similar study under automatic brightness control (ABC). As well the systematic study of IQ as a function of EDR as the study performed under ABC point to a better IQ for FD in cinegraphy mode and no difference between both systems in fluoroscopy mode. The patient population study resulted in mean DAP values of 31 Gy cm² (II system) and 33 Gy cm² (FD system) (p = 0.68) for CA procedures. As well total DAP as contributions of fluoroscopy and cinegraphy on both systems are not significantly different.To conclude, we could state that profit was taken from the intrinsic better performance of the FD for cinegraphy mode in producing higher quality images in this mode but without any effect on patient dose for CA procedures.     

A national patient dose survey and setting of reference levels for interventional radiology in Bulgaria

Objectives

A national study on patient dose values in interventional radiology and cardiology was performed in order to assess current practice in Bulgaria, to estimate the typical patient doses and to propose reference levels for the most common procedures.

Methods

Fifteen units and more than 1,000 cases were included. Average values of the measured parameters for three procedures—coronary angiography (CA), combined procedure (CA?+?PCI) and lower limb arteriography (LLA)—were compared with data published in the literature.

Results

Substantial variations were observed in equipment and procedure protocols used. This resulted in variations in patient dose: air-kerma area product ranges were 4–339, 6–1,003 and 0.2–288 Gy cm² for CA, CA?+?PCI and LLA respectively. Reference levels for air kerma-area product were proposed: 40 Gy cm² for CA, 140 Gy cm² for CA?+?PCI and 45 Gy cm² for LLA. Auxiliary reference intervals were proposed for other dose-related parameters: fluoroscopy time, number of images and entrance surface air kerma rate in fluoroscopy and cine mode.

Conclusions

There is an apparent necessity for improvement in the classification of peripheral procedures and for standardisation of the protocols applied. It is important that patient doses are routinely recorded and compared with reference levels.

Key Points

? Patient doses in interventional radiology are high and vary greatly ? Better standardisation of procedures and techniques is needed to improve practice ? Dose reference levels for most common procedures are proposed     

Evaluation of exposure dose to patients undergoing catheter ablation procedures—a phantom study

The aim of this study was to evaluate entrance skin dose (ESD), organ dose and effective dose to patients undergoing catheter ablation for cardiac arrhythmias, based on the dosimetry in an anthropomorphic phantom. ESD values associated with mean fluoroscopy time and digital cine frames were in a range of 0.12–0.30 Gy in right anterior oblique (RAO) and 0.05–0.40 Gy in left anterior oblique (LAO) projection, the values which were less than a threshold dose of 2 Gy for the onset of skin injury. Organs that received high doses in ablation procedures were lung, followed by bone surface, esophagus, liver and red bone marrow. Doses for lung were 24.8–122.7 mGy, and effective doses were 7.9–34.8 mSv for mean fluoroscopy time of 23.4–92.3 min and digital cine frames of 263–511. Conversion coefficients of dose-area product (DAP) to ESD were 8.7 mGy/(Gy·cm²) in RAO and 7.4 mGy/(Gy·cm²) in LAO projection. The coefficients of DAP to the effective dose were 0.37 mSv/(Gy·cm²) in RAO, and 0.41 mSv/(Gy·cm²) in LAO projection. These coefficients enabled us to estimate patient exposure in real time by using monitored values of DAP.     

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。     

Live MR Angiographic Roadmapping for Uterine Artery Embolization: A Feasibility Study

PurposeTo assess the feasibility of live magnetic resonance (MR) angiography roadmapping guidance for uterine artery (UA) embolization (UAE) for fibroid tumors.Materials and MethodsTwenty patients underwent UAE with live MR angiographic roadmapping. The pre-acquired MR angiography scan was coregistered with the live intraprocedural fluoroscopy stream to create a visual roadmap to direct the microcatheter during UAE. Patient radiation dose, as measured by dose–area product (DAP), procedure time, contrast medium volume, and fluoroscopy time, was recorded. For the first 10 patients, an additional parameter of contrast medium volume needed to catheterize each UA was recorded.ResultsIn all 20 patients (40 UAs), the MR angiography overlay on live fluoroscopy was accurate and allowed for successful catheterization of the UA, resulting in a technical success rate of 100%. In the subset of the initial 20 UAs (ie, the first 10 patients) in which this data point was recorded, 17 (85%) were successfully catheterized with no iodinated contrast medium at all, by purely relying on the MR angiography roadmap. Mean procedure time was 45 minutes (range, 30–99 min), mean contrast agent dose was 75 mL (range, 46–199 mL), and mean DAP was 155 Gy·cm² (range, 37–501 Gy·cm²).ConclusionsLive MR angiographic roadmapping is feasible and accurate for catheter guidance during UAE.     

Comparison of a conventional and a flat-panel digital system in interventional cardiology procedures

The purpose of the study was to analyse the technical characteristics of a newly installed flat-panel fluoroscopy (FPF) system in an interventional cardiology (IC) department and compare it with an older conventional system. A patient survey was performed to investigate the radiation doses delivered by the X-ray systems. Finally, methods of technique optimization regarding the new digital system were investigated. Dose rates in all fluoroscopic and cine modes were measured and image quality assessed using a dedicated test tool. 200 patients were investigated, half using the conventional and half using the digital FPF system. Patient data collected were: sex, age, weight, height, dose-area product (DAP), fluoroscopy time (T) and total number of frames (F). Our results are: (1) Digital FPF system: high contrast resolution (HCR) is not affected by fluoroscopic mode, whereas low contrast resolution (LCR) is slightly decreased in the low mode. (2) The digital FPF system has 2.5 times better HCR than the conventional system, with 5 times lower dose in the fluoroscopy mode. (3) Median values of DAP, T and F, respectively, in coronary angiography (CA) are: 27.7 Gycm(2), 4.1 min and 876 for the digital and 39.3 Gycm(2), 5.3 min and 1600 for the conventional system. Median values for percutaneous transluminal coronary angioplasty (PTCA) are: 51.1 Gycm(2), 12.7 min and 1184 for the digital and 44.3 Gycm(2), 7.4 min and 1936 for the conventional system. Digital DAP in CA is reduced by 30%, suggesting that a dose reduction in the FPF system is possible. The results of the study concerning the FPF system lead to the conclusion that the lowest fluoroscopic mode and the lowest frame rate should be used in routine practice.     

The impact of radiological equipment on patient radiation exposure during endovascular aortic aneurysm repair

Objectives

To compare the patient radiation dose during endovascular aortic aneurysm repair (EVAR) using different types of radiological systems: a mobile fluoroscopic C-arm, mobile angiographic and fixed angiographic equipment.

Methods

Dose–area products (DAP) were obtained from a retrospective study of 147 consecutive patients, subjected to 153 EVAR procedures during a 3.5-year period. On the basis of these data, entrance surface dose (ESD) and effective dose (ED) were calculated. EVARs were performed using a fluoroscopic C-arm, mobile or fixed angiographic equipment in 79, 26 and 48 procedures, respectively.

Results

Fluoroscopy times were essentially equivalent for all the systems, ranging from 15 to 19?min. The clinical outcomes were not significantly different among the systems. Statistically significant differences among radiological equipment grouping were found for DAP (mobile C-arm: 32?±?20?Gy?cm²; mobile angiography: 362?±?164?Gy?cm²; fixed angiography: 464?±?274?Gy?cm²; P?<?10^?6), for ESD (mobile C-arm: 0.18?±?0.11?Gy; mobile angiography: 2.0?±?0.8?Gy; fixed angiography: 2.5?±?1.5?Gy; P?<?10^?6) and ED (mobile C-arm: 6.2?±?4.5?mSv; mobile angiography: 64?±?26?mSv; fixed angiography: 129?±?76?mSv; P?<?10^?6).

Conclusions

Radiation dose in EVAR is substantially less with a modern portable C-arm than with a fixed or mobile dedicated angiographic system.

Key Points

? Fluoroscopy during endovascular aortic aneurysm repair can impart a substantial radiation dose. ? Radiation doses during EVAR are higher when using mobile/fixed angiographic systems. ? Mobile C-arm fluoroscopy imparts a lower dose with an equivalent clinical outcome. ? Procedures need to be dose-optimised when using mobile/fixed angiographic systems.     

Contemporary Interventional Radiology Dosimetry: Analysis of 4,784 Discrete Procedures at a Single Institution

PurposeTo report dosimetry of commonly performed interventional radiology procedures and compare dose analogues to known reference levels.Materials and MethodsDemographic and dosimetry data were collected for gastrostomy, nephrostomy, peripherally inserted central catheter placement, visceral arteriography, hepatic chemoembolization, tunneled catheter placement, inferior vena cava filter placement, vascular embolization, transjugular liver biopsy, adrenal vein sampling, transjugular intrahepatic portosystemic shunt (TIPS) creation, and biliary drainage between June 12, 2014, and April 26, 2018, using integrated dosimetry software. In all, 4,784 procedures were analyzed. The study included 2,691 (56.2%) male subjects and 2,093 (43.8%) female subjects with mean age 55 ± 21 years (range: 0-104 years) and with mean weight of 76.9 ± 29.4 kg (range: 0.9-268.1 kg). Fluoroscopy time, dose area product (DAP), and reference dose were evaluated.ResultsTIPS had the highest mean fluoroscopy time (49.1 ± 16.0 min) followed by vascular embolization (25.2 ± 11.4 min), hepatic chemoembolization (18.8 ± 12.5 min), and visceral arteriography (17.7 ± 3.2 min). TIPS had the highest mean DAP (429.2 ± 244.8 grays per square centimeter [Gy·· cm²]) followed by hepatic chemoembolization (354.6 ± 78.6 Gy·· cm²), visceral arteriography (309.5 ± 39.0 Gy·· cm²), and vascular embolization (298.5 ± 29 Gy·· cm²). TIPS was associated with the highest mean reference dose (2.002 ± 1.420 Gy) followed by hepatic chemoembolization (1.746 ± 0.435 Gy), vascular embolization (1.615 ± 0.381 Gy), and visceral arteriography (1.558 ± 1.720 Gy). Of the six procedures available for comparison with the reference levels, the mean fluoroscopy time, DAP, and reference dose for each procedure were below the proposed reference levels.ConclusionAdvances in image acquisition technology and radiation safety protocols have significantly reduced the radiation exposure for a variety of interventional radiology procedures.     

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...     

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.