Digital subtraction cerebral angiography by intraarterial injection: comparison with conventional angiography

Tumefactive Primary Central Nervous System Vasculitis: Imaging Findings of a Rare and Underrecognized Neuroinflammatory Disease

Primary central nervous system vasculitis (PCNSV) is a poorly understood neuroinflammatory disease of the CNS affecting the intracranial vasculature. Although PCNSV classically manifests as a multifocal beaded narrowing of the intracranial vessels, some patients may not have angiographic abnormalities. A rare subset of patients with PCNSV present with masslike brain lesions mimicking a neoplasm. In this article, we retrospectively review 10 biopsy-confirmed cases of tumefactive PCNSV (t-PCNSV). All cases of t-PCNSV in our series that underwent CTA or MRA were found to have normal large and medium-sized vessels. T-PCNSV had a variable MR imaging appearance with most cases showing cortical/subcortical enhancing masslike lesion (70%), often with microhemorrhages (80%). Diffusion restriction was absent in all lesions. In summary, normal vascular imaging does not exclude the diagnosis of t-PCNSV. Advanced imaging techniques including MR perfusion and MR spectroscopy failed to demonstrate specific findings for t-PCNSV but assisted in excluding neoplasm in the differential diagnosis. Biopsy remains mandatory for definitive diagnosis.

Angiographic "Blush" After Stereotactic Radiosurgery Ablation of Residual Arteriovenous Malformation in Pediatric Patient: Case Report and Review of Literature

INTRODUCTION

While surgical resection remains a primary treatment for accessible arteriovenous malformations (AVMs), stereotactic radiosurgery (SRS) has become thoroughly integrated into the AVM armamentarium; however, delayed sequelae of this treatment have become evident with increased long-term follow-up. To our knowledge, this is the second case of an aberrant local arterial angiographic blush without early venous drainage or an associated lesion following AVM SRS.

CASE DESCRIPTION

An 8-year-old female presented with a ruptured 4-cm right medial frontal periventricular Spetzler-Martin grade 3 AVM with isolated intraventricular hemorrhage. She underwent subtotal resection followed by SRS. Six years later, diagnostic cerebral angiography demonstrated a prominent arterial-phase filling microvasculature without early venous drainage in the region of the irradiated residual AVM nidus.

CONCLUSION

Although there is a paucity of information on angiographic blush following AVM SRS, consensus in the literature suggests that without early venous drainage, these lesions appear to pose an insignificant threat to the patient. These angiographic findings may be on a spectrum of delayed cerebrovascular radiation changes, and thus indefinite follow-up may be considered, especially in pediatric patients.

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 aorta 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.

Acute vasoconstriction after subarachnoid hemorrhage

OBJECTIVE

Decreased cerebral blood flow (CBF) and cerebral ischemia occurring immediately after subarachnoid hemorrhage (SAH) may be caused by acute microvascular constriction. However, CBF can also be influenced by changes in intracranial pressure (ICP) and cerebral perfusion pressure (CPP). The goal of these experiments was to assess the significance of acute vasoconstriction after SAH and its relationship to changes in CBF, ICP, CPP, and extracellular glutamate concentrations.

METHODS

Three experiments were performed using the endovascular filament technique to produce SAH. In the first experiment, CBF, ICP, and CPP were measured for 60 minutes after SAH (n = 21) and were correlated with the 24-hour mortality rate. In the second experiment, rats undergoing SAH (n = 23) or a sham procedure (n = 7) were perfused 60 minutes after SAH for measurement of the circumference and wall thickness of the internal carotid and anterior cerebral arteries and correlation with CBF, ICP, and CPP. In the third experiment (n = 11), extracellular glutamate concentrations determined by hippocampal and cortical microdialysis and high performance liquid chromatography were correlated with physiological changes.

RESULTS

CBF reductions to less than 40% of baseline for 60 minutes after SAH predicted 24-hour mortality with 100% accuracy and were used to define "lethal" SAH. In contrast, ICP and CPP 60 minutes after SAH were not correlated with the mortality rate. The vascular circumference was significantly smaller in lethal than in sublethal SAH or sham-operated rats (P < 0.001). Vessel measurements were correlated with both CBF and hemorrhage size (P < 0.01). Extracellular glutamate concentration increased to 600% of baseline after lethal SAH in both hippocampus and cortex and was inversely correlated with CBF (r = 0.9, P < 0.001) but did not increase after sublethal SAH.

CONCLUSION

Acute vasoconstriction after SAH occurs independently of changes in ICP and CPP and is associated with decreased CBF, larger hemorrhage size, persistent elevations of extracellular glutamate, and poor outcome. Acute vasoconstriction seems to contribute directly to ischemic brain injury after SAH. Further evaluations of pharmacological agents with the potential to reverse acute vasoconstriction may increase CBF and improve outcome.

Neuroradiological applications of a new system of stereoscopic biplane digital subtraction angiography

A stereoscopic biplane digital subtraction angiography (DSA) system was developed, capable of obtaining frontal and lateral projections simultaneously during a single injection of contrast medium. This new system combines the advantages of both biplane and stereoscopic single-plane DSA, and permits high-quality neuroangiography.

Evaluation of the carotid artery bifurcation: comparison of magnetic resonance angiography and digital subtraction arch aortography

Thirty-four carotid artery bifurcations were examined using both magnetic resonance angiography (MRA) and digital subtraction arch aortography to determine their accuracy when compared to selective carotid angiography. The sensitivity of MRA was 73% and its specificity was 91% when compared with selective carotid angiography. The sensitivity of arch aortography was 27% and its specificity was 100%.

The importance of preoperative digital subtraction angiography in microsurgically reanastomosed tissue transfer

The importance of preoperative digital subtraction angiography (DSA) in revascularized tissue transfer in the maxillofacial area is demonstrated on the basis of 53 flaps: In 7 cases DSA revealed results which influenced the therapeutic procedure. Compared to conventional methods of vascular diagnosis, DSA has considerable advantages.

Digital subtraction angiography (DSA). Work load and financial implications for a neuroradiology department

A four year study has been undertaken into the effects on the workload and cost implications of the introduction of digital subtraction angiography (DSA) in a large United Kingdom teaching hospital. The increase in workload has been entirely due to the ability to perform intravenous angiography. DSA is cheaper than conventional angiography if more than 210 cases are undertaken each year. This difference is accounted for by the reduced use of X-ray film. However, intravenous angiography is more expensive because of the use of large volumes of nonionic medium.

High resolution DSA: experimental and clinical evaluation

The DSA system has been upgraded for capabilities of slow scan video technique and progressive T.V. read-out of 1024 X 1024 matrix with 10 bits of depth. A square wave test pattern made of lead bar demonstrated moderate improvement in spatial resolution, but imaging of a Burger-Rose phantom revealed no significant increase in contrast resolution. Clinical study of various angiograms with intraarterial injections showed that there was slight improvement in the visibility of the vessels, especially small arterial branches, while there was no increase in visibility of the veins. There were no cases in which diagnoses were altered by application of high resolution DSA. With future improvements of the image intensifiers, DSA with 1024 X 1024 matrix may reveal its potential advantage, especially when coupled to larger image intensifiers such as 12 or 14 in.

Emergency CT head scans in traumatic and atraumatic conditions

Head trauma and suspected subarachnoid hematoma are encountered frequently by the emergency physician. There are few data to indicate which patients need immediate computerized tomography (CT) and what is the role of lumbar puncture in subarachnoid hemorrhage. Reviewed are the classification of head trauma and subarachnoid hemorrhage, indications for immediate CT, persons needing contrast enhancement, and the use of CT in comparison to skull films, digital subtraction angiography, and magnetic resonance.

Intra-arterial digital subtraction angiography of the carotid arteries. Special reference to contrast media

A cross-over test in intra-arterial digital subtraction angiography (IADSA) of the carotid arteries was performed in 50 patients to evaluate image quality and side-effects with iohexol and metrizoate injected at concentrations of 100 mg I/ml by hand. The image quality was excellent or good in all cases. Although the severity and the frequency of side-effects were higher with metrizoate, both contrast media were suitable for IADSA at this low concentration. No complications were seen. It was assumed that the risk with IADSA was less than that of conventional precerebral angiography when performed semi-selectively and with small amounts of contrast media, as in this study.

Digital subtraction angiography: current clinical applications

The applications of digital subtraction angiography (DSA) in neurologic diagnosis have been evolving as clinical experience with this technology accumulates. Initial enthusiasm with the intravenous contrast material injections has been tempered by often equivocal results. Intravenous DSA (IV-DSA) is still an accurate screening technique for extracranial carotid atherosclerosis, comparable to duplex ultrasound. Intracranial imaging is less satisfying with intravenous injections but reliable information is available in the assessment of the venous sinuses and parasellar internal arteries. The future of DSA lies with intraarterial contrast injections, as this technique substantially decreases the risks and costs of definitive cerebrovascular investigation.

Intra-arterial DSA: early experience with a 1024(2) matrix

Twenty patients were studied with intra-arterial digital subtraction angiography (IA DSA), utilizing a 1024(2) matrix memory. Acquisition of the images was through a prototype television camera incorporating a finely focused electron beam. In five cases, comparison between a 512 X 512 (512(2)) matrix acquisition and a 1024 X 1024 (1024(2)) matrix acquisition mode was made, with injections occurring in the same vessel in the same patient. The clinical material demonstrated no significant improvement in image quality at the 4 1/2 as well as the 6 inch image intensifier (II) modes. However, the 1024(2) matrix combined with the 9 inch II mode showed foci of disease and normal anatomy with detail not always seen on the 9 inch II when a 512(2) matrix was used. In no case, however, was the basic diagnosis missed with the 512(2) matrix. Spatial resolution, as measured from lead bar test pattern images, demonstrated that the 1024(2) matrix allows a 70% or greater improvement in spatial resolution over the 512(2) for the 4 1/2, 6 and 9 inch II modes. For a given mode the radiation dose was held constant for the two matrix sizes.

Digital subtraction angiography: principles and potential applications in emergency medicine

Digital subtraction angiography (DSA) is a new computer-assisted process which enables visualization of arterial structures after intravenous injection of contrast material. Technical requirements of the process mandate total patient cooperation during the filming sequence, which generally lasts five to ten seconds. Because of lower spatial resolution compared with conventional angiography, and difficulty with vessel overlap as a result of nonselective opacification, DSA has not supplanted conventional angiography in evaluation of traumatic vascular injuries. The technology of DSA, currently accepted uses, and potential future uses of DSA are discussed. Future improvements in DSA promise to make it more amenable to the evaluation of traumatic vascular injuries.

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

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.

[Preoperative intra-arterial digital subtraction angiography in aortoiliac vascular occlusion]

Sixteen patients with advanced aorto-iliac occlusive disease were examined with digital subtraction angiography (DSA) using intraarterial injection of contrast medium. The preoperative evaluation of the vessels distal to the occlusion and the visualization of the femoral and popliteal arteries were successfully performed with intraarterial DSA. As compared to conventional angiography the marked contrast enhancement of DSA is demonstrated. Less spatial resolution of DSA lacks importance as the herein discussed topic is concerned. The limited size (23 cm) of the image intensifier of the X-ray equipment used was a major drawback of the method. Using intravenous DSA aorto-iliac occlusion can be shown. In patients with long range vascular occlusion and sparse development of collaterals only intraarterial DSA can demonstrate the run-off vessels including the trifurcation of the popliteal artery.

Current experience with digital subtraction angiography in the community medical center

At the community medical center, we have introduced and successfully applied digital subtraction angiography (DSA) to disease processes seen in 1,144 patients. Although there is a trade-off between increased contrast resolution and decreased spatial resolution with the DSA approach, nonetheless in many vascular beds it provides rapid, safe, and accurate disease diagnosis.

Intraarterial digital subtraction angiography: a comparative view

Intraarterial digital subtraction angiography (IA DSA) was performed in 122 patients undergoing a variety of diagnostic and interventional angiographic procedures. Owing to the increased contrast resolution of DSA, diluted contrast material in concentrations of from 12-19% could be employed, thereby significantly reducing contrast material doses compared to doses used with conventional film-screen angiography or intravenous DSA. Patient discomfort was convincingly reduced due to the injection of dilute contrast material. Subtracted digital images could be viewed immediately on a cathode ray tube (CRT) resulting in faster procedures with less catheter time. Savings in film costs relative to conventional angiography were also achieved.