Evaluation of the cerebral vasculature by intraarterial DSA-with emphasis on in vivo resolution

Summary Comparative study was performed between IA DSA and stereoscopic magnification angiography in relation to small vessel resolution, image quality of the vessels and image quality of various pathologic lesions. The vessels of various diameters, accurately measured by stereoscopic magnification angiography, were localized on IA DSA and their resolution was carefully assessed. The vessels more than 1 mm in diameter were equally visualized on IA DSA and conventional angiography. The vessels between 1 mm and 0.5 mm showed fair resolution on IA DSA, whereas IA DSA did not resolve the vessels smaller than 0.5 mm in diameter to good advantage. In addition, image quality of the vessels on IA DSA was compared with the conventional methods. Cerebral gyrus, venous sinuses, and intracerebral veins are often shown better on DSA. The small vessels such as lenticulostriate, small cortical, thalamoperforate and meningohypophyseal arteries were not defined on DSA. Equal or better image quality was obtained in more than 85% of cases with pathologic lesions. Examinations were performed faster with lower cost and lower complication rate. Information provided by DSA was often sufficient for managements of patients. Combined use of DSA and conventional angiography will improve diagnostic accuracy and decrease the complication rate.     

Digital intraarterial subtraction technique of the extracerebral vascular system

We report the results from intraarterial digital subtraction angiography (IA DSA) of the extracerebral vessels with aortic arch injection of contrast medium via femoro-arterial puncture, instead of the more widely used intravenous digital subtraction angiography (IV DSA). Intraarterial DSA is performed using a lower contrast dose and rate, making this study less invasive and costly than the conventional arteriographic study of the aortic arch. Intraarterial DSA provides better resolution than IV DSA. The diagnostic accuracy is almost equivalent to conventional angiography and is largely superior to photographic subtraction angiography with intravenous injection of contrast media.     

Renal digital subtraction angiography

Digital subtraction angiography (DSA), a new computer-assisted radiographic procedure, has recently been applied to the evaluation of the kidney and in the screening of patients with renal vascular hypertension. The efficacy of the method in the evaluation of the anatomy of proximal renal arteries is in the 80–90% range; however, DSA is less effective in the evaluation of renal mass lesion. In the present state of DSA development, the method has a place in screening for renal artery stenosis (RAS). Further development, particularly improvement in spatial resolution, will be necessary before this procedure can substitute for renal angiography, in the evaluation of renal masses or in some cases of RAS.     

Cardiac imaging with digital subtraction angiography

Central cardiovascular anatomy and function have been evaluated with intravenous digital subtraction angiography (DSA). The subtraction techniques used for studying the left ventricle (LV) were mask mode, time interval difference and functional subtraction. Aside from contrast enhancement, a major use of digital fluoroscopy for cardiac applications has been computer-assisted quantitative analysis of LV dimensions and function. Left ventricular volumes and wall thickness determined from DSA studies have correlated closely with direct left ventriculograms and sonocardiometry measurements in patients and animals, respectively. Measurements of segmental LV contraction with DSA correlated closely with direct left ventriculography in normal patients and patients with coronary artery disease. The sensitivity of intravenous DSA for detecting significant coronary artery disease was increased by performing DSA immediately after increasing the myocardial oxygen demands by atrial pacing. The advantages and disadvantages of DSA in relation to other semi-or non-invasive imaging modalities are discussed.     

三维DSA 技术在脑血管病诊断与血管内治疗中的应用

目的评价三维DSA（3D DSA）技术在脑血管病诊断及治疗中的应用价值。方法对60例患者所做3D DSA影像与传统二维DSA（2D DSA）进行比较，分析颅内动脉瘤及动脉狭窄在3D DSA上的影像表现。结果与2D DSA相比，3D DSA在对动脉瘤显示有优越性；但对脑动脉狭窄的显示无明显差异。结论3D DSA可以充分显示动脉瘤的形态、位置以及周围解剖关系，并可以从剖面观察病变血管内情况，对斑块稳定性的判断有一定优势，在介入治疗过程中具有重要价值。     

Intravenous digital subtraction angiography of the thoracic and abdominal aorta

Intravenous digital subtraction angiography (IV DSA) is a new imaging modality that utilizes techniques of video image acquisition and computer image manipulation to provide anatomic information about blood vessels and organs. In many ways, it represents an electronic version of classic intravenous and film-subtraction angiography. As a means of imaging the thoracic and abdominal aorta, IV DSA has demonstrated great potential, particularly in vessels originally imaged by the former techniques. We have imaged the aorta in over 300 cases at Brigham and Women's Hospital, either alone, or in combination with other vessels in the course of work-up for vascular disease. Although experience has been limited, intravenous imaging of the aorta can be routinely performed, providing reliable and clinically significant information. Supported in part by CV Training Grant 201-HL20895-06     

Magnetization spoiling in radial FLASH contrast-enhanced MR digital subtraction angiography

Purpose:

To increase the in‐plane spatial resolution and image update rates of 2D magnetic resonance (MR) digital subtraction angiography (DSA) pulse sequences to 0.57 × 0.57 mm and 6 frames/sec, respectively, for intracranial vascular disease applications by developing a radial FLASH protocol and to characterize a new artifact, not previously described in the literature, which arises in the presence of such pulse sequences.

Materials and Methods:

The pulse sequence was optimized and artifacts were characterized using simulation and phantom studies. With Institutional Review Board (IRB) approval, the pulse sequence was used to acquire time‐resolved images from healthy human volunteers and patients with x‐ray DSA‐confirmed intracranial vascular disease.

Results:

Artifacts were shown to derive from inhomogeneous spoiling due to the nature of radial waveforms. Gradient spoiling strategies were proposed to eliminate the observed artifact by balancing gradient moments across TR intervals. The resulting radial 2D MR DSA sequence (2.6 sec temporal footprint, 6 frames/sec with sliding window factor 16, 0.57 × 0.57 mm in‐plane) demonstrated small vessel detail and corroborated x‐ray DSA findings in intracranial vascular imaging studies.

Conclusion:

Appropriate gradient spoiling in radial 2D MR DSA pulse sequences improves intracranial vascular depiction by eliminating circular banding artifacts. The proposed pulse sequence may provide a useful addition to clinically applied 2D MR DSA scans. J. Magn. Reson. Imaging 2012;36:249–258. © 2012 Wiley Periodicals, Inc.     

CT血管造影在动脉瘤诊断中的应用价值

目的探讨CT血管造影（CTA）在脑动脉瘤诊断中的应用价值。方法对26例自发性蛛网膜下腔出血（SAH）患者行CTA，寻找动脉瘤（包括动脉瘤的部位、大小、数目），并经数字减影血管造影（DSA）或手术证实。结果本组26例患者共检出21例22个动脉瘤（1例为2个动脉瘤），其中前交通动脉瘤8个，后交通动脉瘤2个，大脑前动脉瘤4个，大脑中动脉瘤5个，颈内动脉瘤3个，10例患者经DSA证实，15例患者经手术证实，1例患者因病情发展迅速，行DSA及手术前死亡。结论CTA无创伤、费用低、安全可靠、所需时间短、三维立体成像空间分辨率高，对于SAH患者的破裂动脉瘤检出有较高的准确性，可以作为SAH患者筛查动脉瘤的初选方法。     

Intravenous digital subtraction angiography in diagnosis of vascular graft occlusion

Differentiation is often difficult between vascular graft occlusion and progression of underlying disease in patients after vascular surgery. We have studied 57 patients after surgery for traumatic and atherosclerotic arterial occlusion and other vascular anomalies using a commercial digital subtraction angiography (DSA) unit; no complications occurred. Indications for examination included pain, diminished pulse, and failure of catheter angiography. Graft patency was established if proximal and distal anastomoses were visualized; occlusion was diagnosed if no graft was imaged or vascular stump found—noted in 31 grafts. Our diagnosis was proved surgically in 24 patients (two refused operation); three others were confirmed angiographically and one by Doppler ultrasonic examination. In our experience DSA is a safe, specific means of following postoperative grafts and diagnosing their occlusion. This work was supported in part by U.S. Public Health Service Grant No. HL07334     

Comparison of intravenous digital subtraction angiography to conventional aortography in patients with abdominal aortic aneurysm

Evaluation of intravenous digital subtraction angiography (IV DSA) in patients with abdominal aortic aneurysm was performed by obtaining catheter aortograms immediately before DSA studies in ten patients. Diagnostic images were obtained in nine of ten digital subtraction examinations. Although repeat injections were necessary in six DSA and three conventional aortography cases for adequate imaging of both cephalad and caudal extension of the aneurysm, average contrast dose was 53 cc (62 cc in standard catheter studies). Renal artery stenosis was diagnosed by DSA in two of three vessels, multiple renal arteries were demonstrated by both modalities in two cases. Digital subtraction and conventional aortographic findings were proved at surgery. Intravenous DSA was shown to be useful in the preoperative evaluation of patients with abdominal aortic aneurysm. This work was supported in part by U.S. Public Health Service Grant No. HL07334.     

孤立性动眼神经麻痹的临床DSA评价

目的 通过对２６０例患者的临床及全脑血管造影分析,评价ＤＳＡ在确诊孤立性动眼神经麻痹病因中的意义和作用。材料与方法 搜集２６０例行全脑血管造影检查的病例,对其临床特征及ＤＳＡ表现进行分析。结果 动脉瘤致孤立性动眼神经麻痹的发生率约占全部动脉瘤的７％。后交通动脉瘤最易导致动眼神经麻痹,其发生率约占全部后交通动脉瘤的７３％,ＤＳＡ可以全面真实地反映致孤立性动眼神 痹的动脉瘤的特征。结论,对于孤立性动眼     

旋转DSA技术及COMPAS功能在血管造影中的应用

目的探讨旋转DSA及COMPAS技术在血管造影中的应用。方法使用GE数字减影机对疑有血管病变的30例进行常规正侧位检查,而后选择合适的技术参数,对18例进行旋转DSA检查。结果18例患者病变血管位置清晰可见。12例脑血管造影中,11例避开了对比剂血管影的重叠,1例显示不佳;6例肝、肾动脉造影均清晰显示狭窄位置。结论旋转DSA技术及COMPAS功能能显示大多数特殊复杂病变血管并能辅助定位,是常规DSA的重要补充,对病变的诊断及治疗有很大价值。     

Time‐resolved angiography: Past,present, and future

The introduction of digital subtraction angiography (DSA) in 1980 provided a method for real time 2D subtraction imaging. Later, 4D magnetic resonance (MR) angiography emerged beginning with techniques like Keyhole and time‐resolved imaging of contrast kinetics (TRICKS) that provided frame rates of one every 5 seconds with limited spatial resolution. Undersampled radial acquisition was subsequently developed. The 3D vastly undersampled isotropic projection (VIPR) technique allowed undersampling factors of 30–40. Its combination with phase contrast displays time‐resolved flow dynamics within the cardiac cycle and has enabled the measurement of pressure gradients in small vessels. Meanwhile similar accelerations were achieved using Cartesian acquisition with projection reconstruction (CAPR), a Cartesian acquisition with 2D parallel imaging. Further acceleration is provided by constrained reconstruction techniques such as highly constrained back‐projection reconstruction (HYPR) and its derivatives, which permit acceleration factors approaching 1000. Hybrid MRA combines a separate phase contrast, time‐of flight, or contrast‐enhanced acquisition to constrain the reconstruction of contrast‐enhanced time frames providing exceptional spatial and temporal resolution and signal‐to‐noise ratio (SNR). This can be extended to x‐ray imaging where a 3D DSA examination can be used to constrain the reconstruction of time‐resolved 3D volumes. Each 4D DSA (time‐resolved 3D DSA) frame provides spatial resolution and SNR comparable to 3D DSA, thus removing a major limitation of intravenous DSA. Similar techniques have provided the ability to do 4D fluoroscopy. J. Magn. Reson. Imaging 2012; 36:1273–1286. © 2012 Wiley Periodicals, Inc.     

支气管动脉DSA造影技术若干问题的探讨

目的 通过对50例支气管动脉DSA造影的分析，探讨支气管动脉DSA造影的技术问题。方法 使用万东CGO—2100型数字减影系统，50例患，年龄38～77岁，其中支气管肺癌43例，支气管扩张大咯血7例，均成功实施支气管动脉DSA造影和介入治疗。结果 50例造影所见，支气管动脉与肋间动脉共干21例，占42％，其中右侧支气管动脉与肋间动脉共干较多，31例中有16例，占51．6％。3例存在脊髓动脉分支或与脊髓动脉共干。两例开口在锁骨下动脉，2例开口在心包隔动脉。结论 支气管动脉DSA造影技术对肺部疾病的介入治疗有重要意义。     

大动脉瘤螺旋CT血管造影与DSA比较研究

目的:探讨大动脉瘤螺旋CT 血管造影(SCTA) 检查技术和应用价值,为合理选择SCTA 和DSA 检查方法提供依据。材料和方法:34 例大动脉瘤,均行SCTA 和DSA 检查,其中29 例经手术证实,术后7 例随访检查用SCTA。SCTA用最大强度投影( MIP) 和表面遮盖显示(SSD) 两种方法重建血管。结果:胸主动瘤10 例,腹主动脉瘤15 例,胸腹主动脉连续性动脉瘤2 例,髂动脉瘤7 例。SCTA 和DSA 均能较好地显示大动脉瘤的部位、形状、范围及夹层情况。MIP 重建图像能显示动脉壁钙化,SSD 重建图像能较好地显示动脉瘤的三维形态,SCTA 结合CT 横断面及多平面重建图像可更清楚显示动脉腔、动脉壁、附壁血栓及动脉周围组织结构。DSA 图像空间分辨力较SCTA 高,但不能清楚显示动脉壁、附壁血栓及动脉周围组织结构。结论:对大动脉瘤可首选SCTA 检查以替代DSA 检查。     

Evaluation of the prone position in digital subtraction angiography of the kidneys

In visualizing the kidneys and renal arteries, the digital subtraction angiography (DSA) image is degraded by peristalsis and overlying bowel gas. In 25 patients we evaluated the efficacy of the prone position to counter these technical difficulties and found that the prone position offers visualization superior to the supine, especially in obese and uncooperative patients and those with abundant bowel gas. We advocate that prone imaging be included routinely in renal DSA.     

多层螺旋CT三维血管成像在颅内动脉瘤评价中的初步应用--与DSA的对比研究

目的通过与数字减影血管造影(DSA)的对比研究,初步探讨三维CT血管成像(3D—CTA)在颅内动脉瘤评价中的应用价值。资料与方法对24例临床疑有颅内动脉瘤患者进行3D—CTA和DSA。3D—CTA后处理技术包括多平面重建(MPR)、最大信号强度投影(MIP)以及容积重建(VRT)。3D—CTA和DSA分别由相互独立的放射科医师实施和诊断,分别记录动脉瘤的位置、大小、形态以及与周围动脉分支等的关系。同时调查神经外科医师及患者对两种影像手段的认可度。结果3D—CTA发现13例15个动脉瘤,遗漏1个直径1．2mm的动脉瘤,发现的最小动脉瘤长径为1.8mm。DSA发现14例16个动脉瘤。CTA在显示瘤颈以及相邻骨质结构上明显优于DSA,而DSA空间分辨率较高。神经外科医师多认为CTA可以用作颅内动脉瘤的筛查和术前评估,而DSA仍是金标准。患者对CTA的接受度较高。结论3D—CTA是检查颅内动脉瘤高度敏感的无创影像手段,它可以作为颅内动脉瘤筛查和术前评估的首选技术。     

DSA在急性缺血性脑血管病介入治疗中的应用

目的探讨DSA在急性缺血性脑血管病介入检查及治疗中的应用价值。方法分析550例急性缺血性脑血管病患者进行介入治疗过程中DSA设备使用情况,总结合理利用DSA设备的经验。结果DSA的应用将有助于急性缺血性脑血管病快速诊断和介入治疗疗效评价;DSA实用投照角度的应用能够清晰显示目标血管狭窄病变的形态、程度等信息,为介入治疗提供最佳工作位置,有助于缺血性脑血管病的影像诊断和介入治疗;旋转DSA图像采集及图像三维重建技术的应用将有助于成功地开展介入治疗手术;应用DSA图像测量技术能够为操作医师选择介入材料提供精确的数据信息。结论合理利用DSA设备对于急性缺血性脑血管病的诊断和介入治疗手术成败起着至关重要的作用。DSA设备为介入治疗提供了良好的操作平台,DSA是诊断急性缺血性脑血管病的金标准。     

脑血管DSA对出血性烟雾病的诊断价值

目的 探讨烟雾病的病因及诊断方法.方法 对20例经CT检查为蛛网膜下腔出血和脑室出血的患者做DSA脑血管造影.结果 20例患者被确诊为烟雾病,累及单侧或双侧的颈内动脉分支和椎动脉分支.结论 DSA脑血管造影是未能明确病因的脑出血患者的常规检查方法,对出血性烟雾病的诊断具有重要价值.     

Image data acquisition,processing, storage and display

It is important to optimize each stage of image formation to minimize and take the greatest advantage of X-ray dose used. For each stage (acquisition, processing, and display) an optimum exists within the limits of physical laws and current technology. These laws must be understood and the technologic limitations imposed by them appreciated to acquire the maximum information from digital subtraction angiography (DSA) examinations.