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.     

The influence of buscopan on adverse reactions to intravascular contrast media

We have analysed the ability of prior intravenous Buscopan (hyoscine butylbromide) injection to influence the incidence and severity of adverse reactions to intravascularly administered, iodinated, ionic contrast medium in 258 consecutive digital subtraction angiographic (DSA) examinations. Adverse reactions were seen in 7.9% of the intravenous and 2.4% of the intra-arterial DSA examinations. The incidence of adverse reactions with and without prior Buscopan injection during intravenous DSA examinations was 8.2% and 7.1%, respectively and during intra-arterial DSA examinations was 5.6% and 1.5%, respectively. This difference is not statistically significant (chi 2-test). We conclude that prior intravenous injection of Buscopan has no influence on the incidence or severity of adverse reactions to intravascular contrast media.     

Digital subtraction angiography in the preoperative evaluation of patients with a renal tumor

Inguinal intravenous digital subtraction angiography (DSA) was performed in 14 patients referred for preoperative evaluation of a renal tumor previously diagnosed by CT and ultrasound. Conventional cavography and aortography were used as reference methods for comparison. Both DSA and conventional angiography were carried out following selective arterial injection to the abnormal kidney. The diagnostic value of DSA in examination of the inferior vena cava was generally comparable to that of conventional cavography. Intravenous aortography was unsuccessful in 2 patients due to motion artifacts. In all other patients, the information provided by DSA regarding the aorta, renal arteries and renal veins was similar to that of conventional aortography. Intrarenal vascular detail, however, was far superior on conventional films and was only useful with DSA when intra-arterial injection was implemented. In one of the 12 diagnostic examinations, localization of the renal mass could not be established by intravenous DSA, but was possible in all others. The inguinal approach advocated permits simultaneous inferior vena cavography and intravenous aortography with one single injection of contrast medium; the method is less traumatic than aortography , and does not require hospitalization of the patient. DSA may also be of value in those cases still requiring selective catheterization of the renal arteries, i.e. for angiotherapy . Intra-arterial DSA then allows reduction of the amount of contrast medium and a rapid processing of the images without detriment to the quality of the examination.     

Digital subtraction angiography of coronary grafts: optimization of technique

Forty patients who had undergone coronary artery bypass surgery were studied with digital subtraction angiography (DSA) to develop an outpatient screening technique for coronary artery bypass graft visualization. Of 103 grafts in 40 patients, 101 were seen: 95 were clearly patent and in six the stump of an occluded graft was seen. Of 32 grafts seen in 14 patients using intraarterial DSA, only 13 (41%) were demonstrated using intravenous DSA. Intraarterial DSA is an effective screening procedure to determine bypass graft patency. However, volumes of 40-45 ml of 76% contrast medium injected at rates of at least 20 ml/sec must be used for each injection to obtain a diagnostic image, and since each projection is complementary and contributes some information, several injections must be used to complete an examination.     

Digital subtraction angiography of the extremities using table translation

Digital subtraction angiography (DSA) of the extremities has been performed with both intravenous and intraarterial injections of contrast material. Intravenous studies are usually site specific and are limited by contrast material load; a complete intraarterial study with multiple injections of contrast material may be time consuming. A feasibility study to evaluate a DSA technique that would allow table translation and imaging of two contiguous regions following a single injection of contrast material--bolus-chase DSA--was performed. Forty-five examinations were performed, 13 intravenously and 32 intraarterially. Twelve intravenous and 16 intraarterial DSA examinations were totally satisfactory. Inadequate studies were predominantly caused by slow arterial clearance of contrast material in the distal calf and by operator error. Compared with conventional DSA, anatomic studies of lower-extremity vessels could be obtained faster and with lower contrast material loads using bolus-chase DSA.     

Intraarterial digital subtraction angiography in diagnostic arteriography

Intraarterial digital subtraction angiography (DSA) was performed in 133 diagnostic arteriographic procedures during a 10-month period. The increased contrast resolution of DSA permitted the use of a dilute (15%) contrast material. A significant reduction in contrast material dose compared with conventional film-screen arteriography and intravenous DSA was thus achieved. This was especially advantageous in patients with diminished renal function. The dilute contrast material also resulted in less patient discomfort. Subtracted images were available immediately on cathode ray tube display, resulting in faster procedures, and a considerable saving in film cost compared with conventional arteriography. It is concluded that intraarterial DSA is a useful technique that may replace conventional film-screen arteriography in many applications.     

Routine evaluation of arteriopathies of the lower extremities by digital subtraction angiography

Intravenous digital subtraction angiography (DSA) was performed in 119 patients with lower extremity ischemia using a 14" amplifier. Four injections of contrast medium were usually necessary for a complete evaluation of this vascular region. Images of good quality were obtained in most cases; movement artifacts and a faint opacification accounted for any poor results, which occurred mainly under the knee. The technique of pixel shifting turned out to be very useful to remove movement artifacts. The "measuring field" allowed us to minimize the problem of the inhomo geneous saturation of the amplifier. In 8% of the cases an intra-arterial DSA has been performed after an unsatisfactory intravenous examination. Conventional angiography appears to be no longer necessary.     

Tomographic digital subtraction angiography: initial clinical studies using tomosynthesis. Work in progress

We have developed a method for acquiring multiple tomographic subtraction images using a rapid, repetitive, circular tomographic motion. The method combines the principles of digital subtraction angiography (DSA) and electronic tomosynthesis. Fifteen patients were examined with the technique using single intravenous bolus injections of contrast material. The image sequence obtained during each injection was first processed with a nontomographic mask subtraction, and the result was then compared with the tomographic DSA scans synthesized from the same sequence. The effective section thickness was approximately 0.5 cm, with each section being 0.5-1.0 cm apart. Twelve of the intravenous DSA scans provided the necessary diagnostic or clinically useful information. Two of the three nondiagnostic scans were caused by avoidable technical reasons. In eight cases, the tomographic DSA scans were superior in quality to the nontomographic scans, exhibited significantly less artifact from patient motion and overlying bowel gas, and were effective in separating overlapping vessels. Tomosynthesis permits multiple electronic imaging of the area of interest without reinjection of contrast material and appears to be more informative than nontomographic intravenous DSA imaging.     

Digital subtraction angiography in Takayasu arteritis

The usefulness and limitation of digital subtraction angiography (DSA) in Takayasu arteritis were investigated in 32 patients. Intravenous DSA was particularly useful in the follow-up of patients with an established diagnosis of Takayasu arteritis. Pulmonary arterial involvement could also be demonstrated with intravenous DSA as obstructive arterial changes and lack of accumulation of contrast medium in the pulmonary parenchyma. Detailed information concerning the site and extent of vascular involvement and development of collateral vessels were obtained with intraarterial DSA. Thickening of the thoracic aortic wall, however, could not be recognized with either intravenous or intraarterial DSA. Conventional angiography of the descending thoracic aortal is still required as an initial examination, particularly when there is no aortic arch involvement. However, there is no doubt that DSA has the potential to become the diagnostic procedure of choice in Takayasu arteritis.     

Flat-detector computed tomography in the assessment of intracranial stents: comparison with multi detector CT and conventional angiography in a new animal model

Objective  

Careful follow up is necessary after intracranial stenting because in-stent restenosis (ISR) or residual stenosis (RS) is not rare. A minimally invasive follow-up imaging technique is desirable. The objective was to compare the visualisation of stents in Flat Detector-CT Angiography (FD-CTA) after intravenous contrast medium injection (i.v.) with Multi Detector Computed Tomography Angiography (MD-CTA) and Digital Subtracted Angiography (DSA) in an animal model.     

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.     

Outpatient DSA in cerebrovascular disease using transbrachial arch injections

Experience with intravenous digital subtraction angiography (DSA) has proven disappointing in the outpatient evaluation of cerebrovascular disease. Vessel superimposition, patient motion, and poor vascular opacification all prevent definitive studies in a significant percentage of patients. These problems were addressed by turning to an intraarterial outpatient DSA technique composed of several elements: (1) right transbrachial catheterization of the ascending aorta using a thin, multiple side-hole, straight catheter; (2) arch injections of relatively small volumes of contrast material; (3) pulsed digital image acquisition with multiple projections; and (4) a limited period of postprocedure observation. A total of 43 outpatients and 16 inpatients was studied in this manner with only two complications, both local. Images of definitive quality and completeness were obtained in 82%-98% of cases, and included the major intracranial as well as the extracranial vessels and their circulatory dynamics. Because the iodine load per injection was relatively low, up to 10 angiograms per case were available for delineating superimposed anatomy and motion degradation. Variations in cardiac output had little impact on image quality, and the average case required less than 60% of the contrast load routinely used for intravenous DSA. The transbrachial approach proved as safe and convenient as intravenous DSA but was more thorough and dependable.     

Digital subtraction angiography for examination of vessels of the leg: use of a 40-cm image intensifier

Digital subtraction angiography (DSA) using a 41-cm (16-in.) image intensifier was performed in 144 patients with peripheral vascular insufficiency. In most cases the entire peripheral vascular bed from the renal arteries to the popliteal trifurcation was demonstrated with four intravenous injections and four exposed fields: (a) aorto-iliac, (b) ilio-femoral, (c) femoro-popliteal, and (d) popliteo-tibial. In 90% of cases the procedure was diagnostic in all regions studied, while in 10 it was nondiagnostic in one or more regions for various reasons (myocardial insufficiency, inadequate contrast bolus, or technical failure). Most failures involved the distal arteries. In spite of some limitations, intravenous DSA using a large-field image intensifier may replace conventional angiography in routine preoperative evaluation of peripheral vascular disease, with intra-arterial injections being performed when the intravenous technique is nondiagnostic.     

Breast lesions examined by digital angiography. Work in progress

Differentiation of benign from malignant lesions in screening for breast cancer is usually arrived at via surgical biopsy, an invasive and costly procedure. Digital subtraction angiography (DSA) of the breast is a less invasive procedure. DSA imaging patterns from 22 patients with malignant and benign lesions were compared with surgical biopsy findings. DSA examinations were performed with the breast in an immobilization device and contrast medium was injected into the superior vena cava. Images were produced with a low kilovoltage (50 kVp) to enhance contrast, and a technique yielding an average dose to the breast of less than 2 rad (0.02 Gy) was used. Preliminary clinical results demonstrate the potential of DSA for differentiation of benign and malignant lesions and justify further investigations of its use as an alternative to surgical biopsy.     

数字减影造影测量左室容积及射血分数的研究

目的：通过心室定量模拟实验,比较长度－面积法和视频密度法测量心室不同收缩及显影状态室腔容积和射血分数（ＥＦ）的准确性。方法：对室壁不同运动状态有室腔显影不均的单,双向造影像,分别以长度－面积法和视频密度法测量室腔容积和ＥＦ并与实际值比较。结果;双向造影的长度－面积法ＥＦ测量值与实际值无显性差异。单向造影的测量值在局部室壁运动减弱时差异显;     

Optimized Angiographic CT Using Intravenous Contrast Injection: A Noninvasive Imaging Option for the Follow-Up of Coiled Aneurysms?

BACKGROUND AND PURPOSE:Because recanalization of coiled cerebral aneurysms is reported to occur, follow-up imaging is mandatory, ideally noninvasively. Our study aimed to evaluate the accuracy of an optimized angiographic CT by using intravenous contrast material injection in the assessment of coiled cerebral aneurysms, compared with MR angiography and digital subtraction angiography, the criterion standard.MATERIALS AND METHODS:We included 69 patients with 76 coiled cerebral aneurysms. In each patient, we performed an angiographic CT with intravenous contrast material injection with a dual rotational acquisition, a time-of-flight MR angiography, and a DSA. The angiographic CT with intravenous contrast material injection data was postprocessed by using newly implemented reconstructions modes and a dual-volume technique. An aneurysm occlusion rate was assessed in angiographic CT with intravenous contrast material injection and MRA; remnants were measured and correlated with DSA, respectively.RESULTS:Twenty-eight remnants were revealed by DSA with a mean size of 3.1 × 3.1 mm. Angiographic CT with intravenous contrast material injection demonstrated a sensitivity of 93% and a specificity of 96% in remnant detection. MRA showed almost identical accuracy (sensitivity of 93%, specificity of 100%). Assessment of remnant size by angiographic CT with intravenous contrast material injection and by MRA revealed a high significant correlation with DSA, respectively (P < .001).CONCLUSIONS:Optimized angiographic CT with intravenous contrast material injection and MRA demonstrated accuracy comparable with that of DSA in the follow-up of coiled aneurysms, respectively. The assessment of remnant size showed a high correlation with DSA for both techniques. Due to the lack of radiation exposure, MRA seems to be the preferred technique. However, angiographic CT with intravenous contrast material injection can be considered a reliable, noninvasive alternative in patients with MR imaging contraindications or in cases of compromising artifacts due to metal implants (ie, clips).

For treatment of cerebral aneurysms, coil embolization has been established as a widely accepted technique.^1,2 Follow-up evaluation is recommended because recanalization is reported in up to 20% of aneurysms,^3–5 with approximately 10% requiring retreatment. In this instance, DSA is still considered the criterion standard, but it has the disadvantage of being an invasive technique with the risk of procedural complications.⁶ Therefore, ideally, a noninvasive imaging technique is desirable as an alternative to DSA. TOF-MRA and contrast-enhanced MRA have demonstrated moderate-to-high diagnostic performance.^7–9 TOF-MRA was superior to contrast-enhanced MRA in terms of coil visibility and is the recommended MR imaging technique.¹⁰ On the other hand, MR imaging may be impossible due to contraindications or lack of availability.Here, angiographic CT by using intravenous contrast material injection could be an alternative, noninvasive imaging option. Angiographic CT allows the acquisition of high-resolution data from a rotational run of a C-arm-mounted flat panel detector that differs from conventional CT in the material composing it. Angiographic CT with intravenous contrast material injection (ivACT) has recently demonstrated comparable image quality to DSA in visualizing cerebral artery vasculature¹¹and has been helpful in aneurysm diagnostics¹² and in the follow-up of clipped aneurysms.¹³ Until now, only angiographic CT with intra-arterial contrast material injection has been investigated in the follow-up of coiled aneurysms, providing promising results.¹⁴ With the implementation of new reconstruction modes and enhanced postprocessing algorithms, the image quality of ivACT could be improved and artifacts could be reduced. Our study aimed to evaluate the accuracy of an optimized, noninvasive ivACT in the follow-up of coiled aneurysms compared with MRA and DSA, the criterion standard.     

Moya moya disease: use of digital subtraction angiography in its diagnosis

Fourteen patients suspected of having Moya Moya disease underwent intravenous digital subtraction angiography (DSA), and the findings from nine of these patients were reviewed and analyzed. Obstruction or stenosis of the supraclinoid portion of the internal carotid artery and the proximal portions of the anterior and middle cerebral arteries was observed in all cases. Arteriography, however, was better than intravenous DSA in demonstrating Moya Moya vessels, differentiating complete occlusion from severe stenosis, and demonstrating important transdural collaterals. The disadvantages of intravenous DSA included inferior spatial resolution, the need for large amounts of contrast media, and relatively high radiation doses. Since the summation of vessels cannot be avoided using DSA, arteriography is necessary for the precise evaluation of cerebral hemodynamics before bypass surgery. Intravenous DSA is a safe, reliable method for diagnosing Moya Moya disease and is suitable for the screening and follow-up examinations of patients with the disease.     

全下肢动脉血管造影技术的临床应用探讨

目的比较血管造影跟踪法(bolus chasing angiography,BCA)与传统法(static digital subtraction angiography,DSA)的技术特点。方法回顾性分析了我院61例全下肢动脉血管造影患者的造影技术参数,其中31例采用BCA、30例采用DSA血管造影技术。分别对完成造影时间、对比剂用量、图像质量、患者吸收辐射剂量(dose-area product,DAP)进行对照分析。结果2种造影技术对比显示:DSA的图像质量在显示胫腓血管上优于BCA,但是DAP值高,对比剂用量多以及检查时间长。经统计学处理,二者差异均具有显著性(P<0.00)。结论BCA与DSA相比具有造影时间短,对比剂量用量少,DAP低的特点,DSA局部观察血管情况较细致。因此,先行BCA筛查,然后针对病变加做局部DSA。     

Subtracted versus non-subtracted digital imaging in peripheral angiography

Digital subtraction angiography (DSA) plays an important role in the management of vascular diseases of the lower extremities. A disadvantage is the lack of an automatically moving table top. We used a 1,024 x 1,024 matrix with a large-screen intensifier system and an automated "stepping" facility. In 161 examinations of the arteries of the lower extremity digital peripheral arteriography was performed with and without the subtraction technique. We compared the influence of different iodine concentrations in DA and DSA. Peripheral DA proved to be equal to peripheral DSA in the region of the pelvis, thigh and knee, with no adequate contrasting being obtained merely in the region of the lower leg arteries in about 45%. It is necessary to use contrast medium at a concentration of 300 mg I/ml. The installation of an automated "stepping" facility reduces the amount of contrast medium needed and the exposure time.     

Failing hemodialysis access grafts: evaluation of complete vascular tree with 3D contrast-enhanced MR angiography with high spatial resolution: initial results in 10 patients

Ten patients with failing hemodialysis access underwent contrast material-enhanced magnetic resonance (MR) angiography within 7 days before digital subtraction angiography (DSA). MR angiography was performed at 1.5 T by using a multistation multiinjection three-dimensional technique, and contrast material was injected via intravenous cannula. In all patients, MR angiographic images displayed the complete arterial inflow tract from the subclavian artery and access proper. The complete venous outflow tract up to the superior caval vein could be evaluated in all but one patient. DSA showed hemodynamically significant stenoses in 13 segments. MR angiography depicted all 13 stenoses and two false-positive findings, resulting in sensitivity of 100% and specificity of 94%.