对比剂团注跟踪技术在下肢动脉造影中的应用

目的：探讨对比剂团注跟踪造影技术（Bolus Chasing）在下肢动脉造影中的临床应用价值及其质量控制。方法：采用对比剂团注跟踪技术对33例患者行下肢动脉造影,并与传统DSA分段造影法（12例）进行对比,分别比较二者的患者X线吸收剂量、对比剂用量、造影完成时间,并对团注跟踪造影图像质量进行分级评价。结果：对比剂团注跟踪技术和传统DsA分段造影法完成单侧下肢动脉造影患者x线吸收剂量分别为（11．00±1．37）mGy和（22．33±2．23）mGy,对比剂用量分别为（19．27±1．92）ml和（28．50±2．28）ml,造影完成时间分别为（4．38±0．49）min和（12．37±0．84）min,差异具有显著性意义（P〈0．05）。结论：采用对比剂团注跟踪技术进行下肢动脉造影较传统分段造影技术具有使用对比剂少、检查时间短、图像直观等优点,且能一次性准确显示全下肢血管的解剖情况,值得临床进一步推广应用。     

颈部单倍与双倍剂量增强磁共振血管造影对比研究

目的探讨使用双倍剂量对比剂在颈部对比增强磁共振血管造影(CE-MRA)检查中的优势。方法选取行颈部CE-MRA检查的患者400例,200例用单倍剂量对比剂,200例用双倍剂量对比剂,行3D-CEMRA扫描,经最大密度投影法(MIP)重组获得整体血管图像,并结合原始图像进行分析。所得结果采用2个独立样本的非参数检验方法进行分析。结果 200例使用单倍剂量对比剂的患者,图像质量优者为122例,良50例,差28例;200例双倍剂量患者,图像质量优者165例,良30例,差5例。结论采用双倍剂量对比剂所获得的颈部动脉血管图像优于单倍剂量对比剂所得的图像质量,有利于减少误差。     

3D-CTA在脊髓血管母细胞瘤中的应用

目的探讨三维CT血管造影(3D-CTA)在脊髓血管母细胞瘤中的应用价值,并与数字减影血管造影(DSA)进行对比。方法回顾性分析28例脊髓血管母细胞瘤的临床、影像学资料,其中13例行术前DSA检查,15例行术前、术后3D-CTA检查。结果 3D-CTA与DSA在肿瘤供血动脉的检出率(P=1.000)及图像质量(P=0.367)方面无统计学差异。然而,脊髓DSA所需对比剂剂量是3D-CTA的1.88倍,有效放射线剂量是3D-CTA的2.73倍,且操作所需时间(平均120 min)远长于3D-CTA操作时间(平均扫描时间1 min)。结论与DSA相比,3D-CTA具有无创、所需对比剂剂量低、辐射少、操作时间短、方便术后复查等优点,对脊髓血管母细胞瘤的手术指导及随访具有重要价值。     

DSA步进技术在糖尿病下肢血管病变诊断中的应用

目的 回顾性分析评价DSA步进技术在下肢血管造影中的应用对糖尿病足诊断的优越性.方法 对2004年1月到2010年3月45例怀疑有下肢血管病变的糖尿病患者行下肢DSA检查,其中24例(31肢)采用DSA步进技术检查,21例(21肢)采用传统的分段DSA检查,观察2种下肢血管造影方法所用的对比剂量、总曝光量、检查耗时以及诊断效果,并进行对比分析研究.结果 步进DSA组平均每侧下肢平均使用对比剂25.26 ml、总检查平均耗时37.26 min,曝光摄片时间平均13.23 s,平均摄片101.65帧;在分段DSA组中上述指标分别为130.00 ml、50.48 min、52.38 s、118.33帧,两组差异有统计学意义.步进DSA组和分段DSA组中图像分别90.3%、90.5%达优,所有图像均达到诊断要求.结论 DSA步进技术可很好地显示糖尿病下肢血管病变,可以一次获得满足诊断要求的影像资料,减少手术操作时间,降低对比剂用量,减少射线接受量.     

对比剂追踪DSA技术临床应用探讨

目的 探讨对比剂追中农DSA技术在胸、腹主动脉、髂及四肢动脉造影中的应用。方法 25例患者进行40例次对比剂追踪DSA检查,使用系统的Mask Before程序,用控制手丙控制导管订的移动,获得与血流速度一致的实时对比剂追踪DSA图像。结果 40例产欠造影中,35例次造影图像质量优良,占87.5％,5例次造影质量欠佳,占12.5％,经非减影处理后仍能满足诊断需要。结论 对比剂追踪DSA能准确显示从胸至四肢的大范围血管解剖结构和血流情况,是一种能连续实时观察多段血管结构的新方法。     

颅内巨大动脉瘤造影的技巧与探讨

数字减影血管造影(digital subtraction angiography,DSA)对脑血管动脉瘤的诊断及介入治疗具有重要的价值。在脑血管造影过程中,对比剂充盈的情况,即高压注射器设定的速度、剂量、压力、患者的状态等因素直接影响成像的结果。特别是对脑血管巨大动脉瘤的造影其设定的技术条件尤其重要。笔者对在DSA检查过程中遇到问题和技巧进行介绍与探讨。     

新型国产DSA设备易用性和辐射剂量分析北大核心CSCD

目的 探究新型国产低剂量DSA造影设备剂量降低技术的临床应用效果,为国产DSA设备改进提供参考。方法 选择接受择期脑血管造影患者并基于其体质量指数配对,配对成功后随机分配到试验组(联影uAngio)和对照组(西门子Axiom Zee Biplane)。评价术中图像质量和设备各操控性能,记录设备的剂量-面积乘积(DAP)率、空气比释动能率(K值率)。测定介入放射治疗过程中患者各测量点辐射剂量。综合评估联影uAngio剂量降低技术的临床应用效果。结果 国产DSA设备联影uAngio图像质量与西门子Axiom Zee Biplane无显著差异,多项操控性能显著优于西门子Axiom Zee Biplane。联影uAngio的DAP率显著低于西门子Axiom Zee Biplane(P=0.001)。两组患者各测量点辐射剂量无显著差异。结论 与西门子Axiom Zee Biplane相比,国产DSA设备联影uAngio在具备相似水准图像质量和更加良好的操作易用性前提下,其DAP率更低。     

DynaCT在肝癌肝动脉化疗栓塞中的临床应用价值

目的 评价DynaCT在肝癌肝动脉化疗栓塞中的应用价值.方法 随机将50例肝癌患者分为Ⅰ、Ⅱ2组,30例在具有DynaCT功能的旋转数字减影血管造影机上行二维 DSA 联合增强DynaCT检查(Ⅰ组),20例单纯行二维DSA检查(Ⅱ组).对2组的手术时间、X线曝光量、对比剂用量进行对比分析;对Ⅰ组内二维DSA图像与增强DynaCT图像进行分析,对比二者对检出病灶和明确血管走行的能力;同时在2组范围内比较普通透视图像和DynaCT图像对碘油沉积显示情况.结果 (1)Ⅰ组和Ⅱ组的手术时间、X线曝光量、对比剂用量均采用独立样本t检验,其中2组间手术时间差异有统计学意义(t手术时间=4.25,P手术时间=0.00<0.05),I组较Ⅱ组缩短了手术时间;2组间X线曝光量、对比剂用量差异无统计学意义(tx线曝光量=0.39,Px线曝光量=0.75>0.05;t对比剂用量=0.32,P对比剂用量=0.70>0.05).(2)Ⅰ组内共10个病灶二维DSA未能发现,其中9个可被增强DynaCT发现,经卡方检验(χ2=4.48,P<0.05),二者差异有统计学意义.(3)Ⅰ组内30例患者中有6例行二维DSA后不能明确肿瘤供血动脉走行,行增强DynaCT后其中5例肿瘤供血动脉走行清楚显示,经卡方检验(χ2=4.14,P<0.05),二者差异有统计学意义.(4)87个病灶行X线透视,显示有51个病灶显示碘油均匀沉积,19个病灶显示碘油部分缺失;而平扫DynaCT显示有45个病灶显示碘油均匀沉积,25个病灶显示碘油部分缺失.结论 在不增加对比剂用量、曝光剂量的条件下,使用DynaCT检查在肝癌化疗栓塞中具有重要的临床应用价值.     

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...     

旋转DSA在肝肿瘤介入治疗中的价值

目的 探讨快速旋转数字减影血管造影(DSA)技术在肝肿瘤经动脉栓塞术中的应用价值。资料与方法 采用Toshiba-2000DSA系统。42例肝肿瘤患者(肝癌39例，肝血管瘤3例)，每一病例均在介入治疗术前、术后行肝固有动脉常规正位血管造影及旋转DSA检查，比较两种方法显示肝内病灶个数及肿瘤供血动脉的敏感性。结果 快速旋转DSA能够显著提高前后重叠的小病灶检出率，旋转DSA发现9例常规DSA漏诊的小病灶。旋转DSA清晰地显示复杂的肿瘤供血动脉及其走行，并计算出导管的插入角度。但同时由于检查时间的延长，使得曝光剂量及对比剂的用量增加。结论 旋转DSA能够多方位清晰地显示迂曲走行的动脉和重叠隐匿的较小的肿瘤病灶，对提高超选择性插管的成功率和降低肝脏肿瘤的漏诊率有着重要意义，是一种重要的补充检查手段。     

A comparison of bolus chasing and static digital subtraction arteriography in peripheral vascular disease

The purpose of this study was to compare the techniques of bolus chasing angiography (BCA) and digital subtraction angiography (DSA). 75 patients with symptomatic atherosclerotic peripheral vascular disease were randomly assigned to have their lower limbs examined by BCA or DSA. Dose-area product (DAP), time of examination and dose of contrast medium were measured. Staff doses were measured with personal electronic dosemeters. Image quality was assessed from the laser printed images. DSA produced better images of vessels below the inguinal ligament, particularly the crural vessels (1/76 vs 17/74 non-diagnostic examinations, p < 0.00001) but at a higher DAP (median 53.8 Gy cm2 vs 18.9 Gy cm2, p < 0.01). Contrast medium dose was higher with BCA (29.8 gI2 vs 25.3 gI2, p < 0.01). Staff doses per unit patient dose were 2.3-3.3 times higher with BCA than DSA. Because of the poor long-term prognosis of patients with peripheral vascular disease, the improved image quality obtained by DSA justifies the increased radiation dose.     

平板DSA低剂量模式在冠状动脉造影术中的应用价值

目的 探讨平板探测器数字减影血管造影系统(DSA)低剂量模式在冠状动脉造影术中的应用价值.方法 选取住院拟行冠状动脉造影术患者60例,均为体重50 ～ 70 kg正常体型,随机分为低剂量模式组30例与常规对照组30例.术后由2位心内科介入治疗医师采用双盲法对所有图像进行评分.分别对两组患者的辐射剂量面积(DAP)、累积...     

Stepped digital angiography with dynamic subtraction: a new diagnostic approach to peripheral angiography

On the basis of our first experiences, a purchasable angiography system for peripheral angiography with dynamic subtraction and stepping (DPSA) has been developed. This study reports on the optimization of this technique and the first clinical results in comparison with conventional screen-film angiography and digital subtraction angiography (DSA) in single steps. For each method, 25 angiograms were interpreted to compare the image quality, the radiation exposure, the contrast medium and the film consumption as well as the examination time. Image quality proved to be comparable in DPSA and DSA in single steps. Both techniques showed better results than conventional angiography, especially in the region of the knee and lower leg. Using DPSA radiation exposure dropped by a factor of 2 compared with conventional angiography and by a factor of 6 compared with DSA in single steps. Consumption of contrast medium can also be reduced in comparison with the other two methods. Film consumption is incomparably higher in conventional screen-film angiography. With DPSA the examination time can be reduced by half on average compared with the other two methods. DPSA may come to be the standard in peripheral angiography. Correspondence to: U. Fink     

The effect of equipment set up on patient radiation dose in conventional and CT angiography of the renal arteries

Patient radiation dose in angiography of the renal arteries was assessed and optimized after installing new radiological equipment. In three separate studies (n=50, 25 and 20) patient exposure was monitored in detail. For the first study default factory settings were used, for the second the number of digital subtraction angiography (DSA) images was halved and the X-ray beam filtering during fluoroscopy was increased, and for the third study filtering during DSA was increased as well. Standard projections were derived and used in Monte Carlo simulations to derive dose conversion coefficients to calculate effective dose from the dose-area product (DAP). Dose conversion coefficients were also calculated for CT angiography (CTA). Using default factory settings on the new angiography system, DAP, number of images and effective dose were much higher than on the replaced unit. For the studies given above, DAP was reduced from 144 Gy cm(2) to 65 Gy cm(2) to 32 Gy cm(2), and effective dose from 22 mSv to 11 mSv to 9.1 mSv, respectively. Effective dose due to CTA was 5.2 mSv. It is concluded that modern angiography systems, resulting in high customer satisfaction, may readily cause much higher patient exposure than older systems. These doses may also be much higher than necessary. Optimization before putting such systems into use is absolutely essential. Internationally accepted recommendations for image quality and technique factors in angiography would be of great help.     

Computer processed fluoroscopic images for digital intravenous renal angiography

We investigated intravenous digital angiography using computer processed fluoroscopic images. Computer processed fluoroscopy (CPF) was compared to conventional digital subtraction angiography (DSA) in 39 patients referred for renal vessel evaluation. For assessment of CPF the anterior-posterior images were compared with the corresponding digital subtraction angiograms. 79% percent of DSA and 71% of CPF studies were diagnostic. Peripheral injection of contrast medium caused deterioration of CPF images. Skin dose measurements were obtained in 24 patients. The median dose for DSA was 8.2 rad, compared to 1.1 rad for CPF. It is concluded that sophisticated algorithms should be investigated for digital angiography, so that high image quality can be achieved with a reduced radiation exposure.     

Imaging guidance with C-arm CT: prospective evaluation of its impact on patient radiation exposure during transhepatic arterial chemoembolization

Purpose

To prospectively evaluate the impact of C-arm CT on radiation exposure to hepatocellular carcinoma (HCC) patients treated by chemoembolization.

Materials and Methods

Patients with HCC (N = 87) underwent digital subtraction angiography (DSA; control group) or combined C-arm CT/DSA (test group) for chemoembolization. Dose-area product (DAP) and cumulative dose (CD) were measured for guidance and treatment verification. Contrast agent volume and C-arm CT utility were also measured.

Results

The marginal DAP increase in the test group was offset by a substantial (50%) decrease in CD from DSA. Use of C-arm CT allowed reduction of DAP and CD from DSA imaging (P = .007 and P = .017). Experienced operators were more efficient in substituting C-arm CT for DSA, resulting in a negligible increase (7.5%) in total DAP for guidance, compared with an increase of 34% for all operators (P = .03). For treatment verification, DAP from C-arm CT exceeded that from DSA, approaching that of conventional CT. The test group used less contrast medium (P = .001), and C-arm CT provided critical or supplemental information in 20% and 17% of patients, respectively.

Conclusions

Routine use of C-arm CT can increase stochastic risk (DAP) but decrease deterministic risk (CD) from DSA. However, the increase in DAP is operator-dependent, thus, with experience, it can be reduced to under 10%. C-arm CT provides information not provided by DSA in 33% of patients, while decreasing the use of iodinated contrast medium. As with all radiation-emitting modalities, C-arm CT should be used judiciously.     

Radiation dose and image quality of X-ray volume imaging systems: cone-beam computed tomography, digital subtraction angiography and digital fluoroscopy

Objective

Radiation dose and image quality estimation of three X-ray volume imaging (XVI) systems.

Methods

A total of 126 patients were examined using three XVI systems (groups 1–3) and their data were retrospectively analysed from 2007 to 2012. Each group consisted of 42 patients and each patient was examined using cone-beam computed tomography (CBCT), digital subtraction angiography (DSA) and digital fluoroscopy (DF). Dose parameters such as dose–area product (DAP), skin entry dose (SED) and image quality parameters such as Hounsfield unit (HU), noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were estimated and compared using appropriate statistical tests.

Results

Mean DAP and SED were lower in recent XVI than its previous counterparts in CBCT, DSA and DF. HU of all measured locations was non-significant between the groups except the hepatic artery. Noise showed significant difference among groups (P?<?0.05). Regarding CNR and SNR, the recent XVI showed a higher and significant difference compared to its previous versions. Qualitatively, CBCT showed significance between versions unlike the DSA and DF which showed non-significance.

Conclusion

A reduction of radiation dose was obtained for the recent-generation XVI system in CBCT, DSA and DF. Image noise was significantly lower; SNR and CNR were higher than in previous versions. The technological advancements and the reduction in the number of frames led to a significant dose reduction and improved image quality with the recent-generation XVI system.

Key Points

? X-ray volume imaging (XVI) systems are increasingly used for interventional radiological procedures. ? More modern XVI systems use lower radiation doses compared with earlier counterparts. ? Furthermore more modern XVI systems provide higher image quality. ? Technological advances reduce radiation dose and improve image quality.     

MR angiography of the carotid arteries: parameters affecting image quality

RATIONALE AND OBJECTIVES: This study was performed to evaluate the relationship between dose levels of contrast medium and image quality in magnetic resonance (MR) angiography of the carotid arteries with fluoroscopically monitored, manually triggered, elliptically ordered image acquisitions. MATERIALS AND METHODS: Twenty-five patients with clinical indications for angiography of the carotid arteries were examined with MR at 1.5 T by using a fluoroscopically monitored, manually triggered, elliptically ordered pulse sequence with the administration of one of three different volumes of gadolinium-based contrast medium. The signal intensities of the vessel lumen and the surrounding tissues were measured in single partitions at the origin of the common carotid artery, the carotid bifurcation, and the intracranial internal carotid arteries. The contrast-to-noise ratio in these regions of interest also was measured. Maximum intensity projection image quality was appraised for blurring, artifacts, venous enhancement, background suppression, and contrast medium distribution. RESULTS: No artifacts or venous enhancement was observed. The position of the fluoroscopic section affected the distribution of contrast medium along the vessel, as evidenced by the difference between the contrast-to-noise ratio at the origin of the common carotid artery and the ratio at the carotid bifurcation and the intracranial internal carotid arteries (P < .01). The contrast medium dose administered was strongly correlated with image quality (r = 0.90). CONCLUSION: Contrast medium dose is related to image quality in MR angiography of the carotid arteries performed with elliptical ordering, fluoroscopic monitoring, and manual triggering.     

Usefulness of cone-beam volume CT with flat panel detectors in conjunction with catheter angiography for transcatheter arterial embolization

PURPOSE: To assess the usefulness of cone-beam volume computed tomography (CT) (cone-beam CT) with use of flat panel detectors of the direct conversion type in conjunction with conventional digital subtraction angiography (DSA) in the diagnosis and treatment of patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Forty-nine consecutive patients (52 suspicious lesions) were prospectively examined. All patients underwent intraarterial rotational angiography with a flat panel detector system, and the cone-beam CT scans were reconstructed from the volume data set. The authors evaluated the diagnostic quality of cone-beam CT for the transcatheter arterial chemoembolization (TACE) procedure. RESULTS: The diagnostic quality of conventional DSA plus cone-beam CT with regard to tumor staining was superior to that of DSA alone. Cone-beam CT showed tumor staining in five lesions that were difficult to diagnose with confidence on the basis of the DSA findings alone. The extent of contrast medium perfusion was sufficiently visualized on all cone-beam CT scans at the tip of the catheter positioned in either the segmental or subsegmental hepatic arteries. In 42 of the 52 lesions (81%), cone-beam CT provided additional useful information for therapeutic decision making or TACE compared with DSA. CONCLUSIONS: Intraarterial cone-beam CT with a flat panel detector can provide clinically acceptable image quality in the assessment of HCC, thereby improving the detection of tumor staining due to HCC and the visualization of the extent of contrast medium perfusion.     

Quality analysis of DSA equipment

Summary In the framework of a quality analysis project for the improvement of digital subtraction angiography (DSA) equipment, an inventory was made of the image quality and radiation dose of DSA equipments in six hospitals in the Netherlands. The image quality was investigated with a contrast detail (CD) phantom. The entrance dose of the radiation on this phantom and the skin dose at the level of the eye lenses and the thyroid gland were measured in these hospitals using a human phantom during a standardised simulated DSA examination of the aortic arch and brachiocephalic arteries, by means of thermo-luminescence dosimeters (TLD). To establish the relation of these measurements on the human phantom and real patient examinations, the same measurements were carried out in our own hospital on 16 patients during a comparable DSA examination. To find the difference from the dose in conventional angiography (CA) the same measurements were carried out in our hospital on 11 patients during a comparable examination. These dose measurements were also carried out on the human phantom with the use of the same CA equipment. We vound large differences in image quality in the various hospitals. Within one hospital, monitor images were better than hard copy images. These differences were strongly related to the amount of radiation used, to the technique of storing the images (digital or analogue) and to the quality of the equipment used to make hard copies (the imager). Recommendations are made for improvement and quality control.