介入诊疗程序中患者皮肤最大受照剂量的检测与评价

目的测定冠脉造影、肝动脉造影、射频消融、脑动脉造影等介入程序中对患者主射束皮肤剂量分布和最大皮肤受照剂量，了解患者皮肤能否发生确定性效应。方法在冠脉造影、肝动脉造影和射频消融3种手术曝光前每个患者背部放9个测量点，每个点2片LiF（Mg，Cu，P）剂量片；脑动脉造影曝光前患者正、侧位各放1个测量点。手术后进行TLD测量。结果肝动脉造影手术时，患者皮肤最大吸收剂量为1683．9mGy，平均吸收剂量607．3mGy；脑动脉造影正位时最大值可达959．3mGy，平均值418．8mGy；侧位最高达704mGy。平均191．52mGy；射频消融最高值为853．8mGy。平均219．7mGy；冠脉造影最大值为456．1mGy，平均227．6mGy。结论本实验结果是对皮肤最大剂量的一种估计值，尚不能精确提供患者皮肤受照的最大值。因为剂量片布放不够密集，可能没有包括很小的高剂量部位。     

介入放射手术临床医生受照剂量调查

介入放射是在X射线等影像导向监视下进行的插管操作或穿刺技术。该方法由于创伤小、效果好、费用相对低廉、病人痛苦少而受到患者的欢迎 ,因此在临床的应用日益扩大。但在介入放射操作中 ,由于工作人员在X射线照射下暴露时间长、防护设施简陋 ,致使操作人员各部位长时间受到X射线照射引起广泛关注[1 ,2 ] ,UNSCEAR 1 993年向联合国大会提交的报告中指出[3 ] ,介入放射学可使病人和操作人员受到很大的剂量。为进一步了解介入操作中工作人员实际受照剂量 ,笔者开展了此项调查 ,现报道如下。一、材料和方法1 仪器和元件 :北京防化研究院生…     

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。     

患者受照剂量问题应得到重视

患者受照剂量问题应得到重视范焱，曲来泽由于科学技术的发展，影像诊断技术已成为现代医学的重要组成部分，当前影像诊断方法已由传统的Ｘ线摄影、Ｘ线透视及造影检查，发展到Ｘ线ＣＴ、介入性检查、磁共振成像、核医学成像、Ｂ型超声等。在Ｘ线检查方面，由于我国医疗保...     

特定照射条件下儿童心血管介入诊疗的受照剂量研究

目的:估算在特定照射条件下不同年龄段儿童接受心血管介入诊疗时主要器官的受照剂量和有效剂量,探讨影响估算受照剂量的主要因素。方法:基于国际放射防护委员会(ICRP)第143号出版物提供的儿童参考人可计算体模数据,建立心血管介入诊疗的特定照射模型,利用蒙特卡罗方法与MCNPX 2.7.0软件模拟计算1、5、10和15岁儿童...     

宇宙射线的变化规律及机组人员受照剂量

对高空辐照环境及变化规律、太阳黑子活动对剂量率的影响、中子剂量贡献、机组人员受照剂量等内容进行了综述。     

介入治疗中减少病人受照剂量的措施

随着介入技术的普及和介入领域的不断拓宽 ,病人接受Ｘ射线照射的剂量越来越大 ,由Ｘ射线引起的皮肤损伤国外已有报道[1 3] 。我院自 1990年开展介入工作以来 ,对病人采取了Ｘ射线综合防护措施 ,收到了良好效果。一、材料和方法1990年 6月～ 2 0 0 2年 3月接受介入检查、治疗的病人718例 ,年龄 13～ 80岁 ,平均年龄 5 8 6岁 ,所有病例介入后随访最短 1个月 ,最长 3年。病人的介入部位分类情况见表 1。采用日本岛津ＺＳ 30 80 0ｍＡＸ射线机 ,检查条件 :管电压 75～ 110ｋＶ ,管电流 0 9～ 3 0ｍＡ。表 1　病人的介入部位分类介入部位例数…     

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.     

加速器治疗肿瘤时睾丸受照剂量的研究

６ＭＶＸ射线是放疗时常用的射线,睾丸是电离辐射敏感器官,从理论上讲受到辐射后就可能发生随机效应。临床医生在医疗照射实践中,往往把靶外器官———睾丸受到的剂量忽略了。靶外器官受辐射产生的远期效应直接影响患者甚至后代的生存质量,这已日渐引起人们的关注［１...     

神经介入手术中患者峰值皮肤剂量水平研究

目的 获得神经介入手术中患者峰值皮肤剂量数据（PSD）,评估患者确定性效应发生风险。方法 使用Gafchromic XR RV3胶片采集北京市某三级甲等医院神经介入手术患者的峰值皮肤剂量,主要研究血管栓塞术、血管成形术、血管造影术等3种常见的神经介入手术。使用Epson Expression 10000XL扫描仪扫描胶片,利用ImageJ和Film QA Pro^TM 2014软件测量和分析胶片。结果 共采集49例神经介入手术患者的峰值皮肤剂量数据,包括血管栓塞术23例、血管成形术14例、血管造影术12例。PSD ≥ 2 Gy患者20例,其中血管栓塞术15例,血管成形术5例。血管造影术患者的PSD均<2 Gy。部分神经介入手术患者的峰值皮肤剂量超过国际放射防护委员会（ICRP）第118号报告中的确定性效应剂量阈值。结论 神经介入手术存在发生确定性效应的风险,建议针对风险较高的患者进行随访观察,及时了解其辐射损伤情况和后续诊治。     

Strategies for reduction of radiation dose in cardiac multislice CT

Because cardiac computed tomography (CT) (mainly coronary CT angiography) is a very promising technique, used more and more for coronary artery evaluation, the benefits and risks of this new low-invasive technique must be balanced. Radiation dose is a major concern for coronary CT angiography, especially in case of repeated examinations or in particular subgroups of patients (for example young female patients). Radiation dose to patient tends to increase from 16- to 64-slice CT. Radiation exposure in ECG-gated acquisitions may reach up to 40 mSv; considerable differences are attributable to the performance of CT machines, to technical dose-sparing tools, but also to radiological habits. Setting radiation dose at the lowest level possible should be a constant goal for the radiologist. Current technological tools are detailed in regard to their efficiency. Optimisation is necessary, by a judicious use of technological tools and also by individual adaptation of kV or mAs. This paper reviews the different current strategies for radiation dose reduction, keeping image quality constant. Data from the literature are discussed, and future technological developments are considered in regards to radiation dose reduction. The particular case of paediatric patients with congenital heart disease is also addressed.     

Patient dose considerations in computed tomography examinations

Ionizing radiation is extensively used in medicine and its contribution to both diagnosis and therapy is undisputable. However, the use of ionizing radiation also involves a certain risk since it may cause damage to tissues and organs and trigger carcinogenesis. Computed tomography (CT) is currently one of the major contributors to the collective population radiation dose both because it is a relatively high dose examination and an increasing number of people are subjected to CT examinations many times during their lifetime. The evolution of CT scanner technology has greatly increased the clinical applications of CT and its availability throughout the world and made it a routine rather than a specialized examination. With the modern multislice CT scanners, fast volume scanning of the whole human body within less than 1 min is now feasible. Two dimensional images of superb quality can be reconstructed in every possible plane with respect to the patient axis (e.g. axial, sagital and coronal). Furthermore, three-dimensional images of all anatomic structures and organs can be produced with only minimal additional effort (e.g. skeleton, tracheobronchial tree, gastrointestinal system and cardiovascular system). All these applications, which are diagnostically valuable, also involve a significant radiation risk. Therefore, all medical professionals involved with CT, either as referring or examining medical doctors must be aware of the risks involved before they decide to prescribe or perform CT examinations. Ultimately, the final decision concerning justification for a prescribed CT examination lies upon the radiologist. In this paper, we summarize the basic information concerning the detrimental effects of ionizing radiation, as well as the CT dosimetry background. Furthermore, after a brief summary of the evolution of CT scanning, the current CT scanner technology and its special features with respect to patient doses are given in detail. Some numerical data is also given in order to comprehend the magnitude of the potential radiation risk involved in comparison with risk from exposure to natural background radiation levels.     

Radiation dose in 320-slice multidetector cardiac CT: A single center experience of evolving dose minimization

BackgroundMinimization of radiation exposure remains an important subject that occurs in parallel with advances in scanner technology.ObjectiveWe report our experience of evolving radiation dose and its determinants after the introduction of 320-multidetector row cardiac CT within a single tertiary cardiology referral service.MethodsFour cohorts of consecutive patients (total 525 scans), who underwent cardiac CT at defined time points as early as 2008, are described. These include a cohort just after scanner installation, after 2 upgrades of the operating system, and after introduction of an adaptive iterative image reconstruction algorithm. The proportions of nondiagnostic coronary artery segments and studies with nondiagnostic segments were compared between cohorts.ResultsSignificant reductions were observed in median radiation doses in all cohorts compared with the initial cohort (P < .001). Median dose-length product fell from 944 mGy · cm (interquartile range [IQR], 567.3–1426.5 mGy · cm) to 156 mGy · cm (IQR, 99.2–265.0 mGy · cm). Although the proportion of prospectively triggered scans has increased, reductions in radiation dose have occurred independently of distribution of scan formats. In multiple regression that combined all groups, determinants of dose-length product were tube output, the number of cardiac cycles scanned, tube voltage, scan length, scan format, body mass index, phase width, and heart rate (adjusted R² = 0.85, P < .001). The proportion of nondiagnostic coronary artery segments was slightly increased in group 4 (2.9%; P < .01).ConclusionWhile maintaining diagnostic quality in 320-multidetector row cardiac CT, the radiation dose has decreased substantially because of a combination of dose-reduction protocols and technical improvements. Continued minimization of radiation dose will increase the potential for cardiac CT to expand as a cardiac imaging modality.     

Radiation dose of cardiac CT—what is the evidence?

Current evidence and most pertinent literature on the radiation dose of cardiac computed tomography (CT) for the noninvasive assessment of coronary artery disease are reviewed. The various means for adjusting CT protocols to lower the radiation to a level that is as low as reasonably achievable are discussed. It is shown that for the target population of cardiac CT, the direct visualization of the heart and coronary arteries outweighs the hypothetical risk of the investigation, provided that indications are prudent and the protocols appropriate.     

Challenging the neuronal MIBG uptake by pharmacological intervention: effect of a single dose of oral amitriptyline on regional cardiac MIBG uptake

Purpose Imaging with metaiodobenzylguanidine (MIBG) is used for the assessment of neuronal dysfunction in various cardiovascular disorders. Although valuable information is obtained by resting MIBG imaging, it is conceivable that competitive interference with the re-uptake mechanism would exaggerate MIBG defects and might unmask subclinical neuronal dysfunction. Tricyclic antidepressants, such as amitriptyline, have been reported to significantly increase cardiac MIBG washout and inhibit uptake into presynaptic neurons. This study was undertaken to assess whether a single oral dose of amitriptyline could influence cardiac MIBG distribution.Methods Six patients (aged 62–81 years; four males, two females) who had demonstrated a normal cardiac MIBG scan during work-up for movement disorders were studied. The patients underwent a second ¹²³I-MIBG study after oral administration of 25 mg amitriptyline within 1 week. Single-photon emission computed tomography images were acquired at 4 h to assess the regional distribution of MIBG, after generation of polar maps and employing a 20-segment model. Mean percentage of peak activity was calculated for each segment at rest and after amitriptyline administration.Results After amitriptyline administration, there was a decrease in regional MIBG uptake in 10±4 segments per patient [62/120 segments (52%): 37 segments with a 5–10% decrease, 25 segments with a >10% decrease]. This change was statistically significant in lateral (P=0.003), apical (P<0.0001) and inferior (P=0.03) regions.Conclusion A single oral dose of amitriptyline can induce changes in the uptake and retention of cardiac MIBG, indicating the feasibility of use of pharmacological intervention in cardiac neurotransmission imaging.     

Ultra-low dose comprehensive cardiac CT imaging in a patient with acute myocarditis

The ability of contrast-enhanced CT to detect “late enhancement” in a fashion similar to magnetic resonance imaging has been previously reported. We report a case of acute myocarditis with coronary CT angiography as well as “late enhancement” imaging with ultra-low effective radiation dose.     

Low cardiac and left anterior descending coronary artery dose achieved with left-sided multicatheter interstitial-accelerated partial breast irradiation

Purpose

Studies have shown that an additional mean dose of 1 Gy to the heart can increase the relative risk of cardiac events. The purpose of this study was to quantify the dose delivered to the heart and left anterior descending artery (LAD) in a series of patients with left-sided breast cancer (BC) or ductal carcinoma in situ treated with multicatheter-accelerated partial breast irradiation (MC-APBI) at a single institution.

Patient Radiation Dose in Diagnostic and Interventional Procedures for Intracranial Aneurysms: Experience at a Single Center

Objective

To assess patient radiation doses during cerebral angiography and embolization of intracranial aneurysms in a large sample size from a single center.

Materials and Methods

We studied a sample of 439 diagnostic and 149 therapeutic procedures for intracranial aneurysms in 480 patients (331 females, 149 males; median age, 57 years; range, 21-88 years), which were performed in 2012 with a biplane unit. Parameters including fluoroscopic time, dose-area product (DAP), and total angiographic image frames were obtained and analyzed.

Results

Mean fluoroscopic time, total mean DAP, and total image frames were 12.6 minutes, 136.6 ± 44.8 Gy-cm², and 251 ± 49 frames for diagnostic procedures, 52.9 minutes, 226.0 ± 129.2 Gy-cm², and 241 frames for therapeutic procedures, and 52.2 minutes, 334.5 ± 184.6 Gy-cm², and 408 frames for when both procedures were performed during the same session. The third quartiles for diagnostic reference levels (DRLs) were 14.0, 61.1, and 66.1 minutes for fluoroscopy time, 154.2, 272.8, and 393.8 Gy-cm² for DAP, and 272, 276, and 535 for numbers of image frames in diagnostic, therapeutic, and both procedures in the same session, respectively. The proportions of fluoroscopy in DAP for the procedures were 11.4%, 50.5%, and 36.1%, respectively, for the three groups. The mean DAP for each 3-dimensional rotational angiographic acquisition was 19.2 ± 3.2 Gy-cm². On average, rotational angiography was used 1.4 ± 0.6 times/session (range, 1-4; n = 580).

Conclusion

Radiation dose in our study as measured by DAP, fluoroscopy time and image frames did not differ significantly from other reported DRL studies for cerebral angiography, and DAP was lower with fewer angiographic image frames for embolization. A national registry of radiation-dose data is a necessary next step to refine the dose reference level.