Catheter Digital Subtraction Angiography Research Articles

Diagnostic performance of computed tomography-digital subtraction angiography and conventional magnetic resonance imaging for evaluating the vascularity of osseous spinal tumors

Background and purposePatients with hypervascular spinal tumors may have severe blood loss during tumor resection, which increases the risks of perioperative morbidity and mortality. However, the preoperative evaluation of tumor vascularity may be challenging; moreover, the reliability of the data obtained in conventional preoperative noninvasive imaging is debatable. In this study, we compared conventional magnetic resonance imaging (MRI) and subtraction computed tomography angiography (CTA) in terms of their performance in vascularity evaluation. The catheter digital subtraction angiography (DSA) technique was used as a reference standard. MethodsThis study included 123 consecutive patients with spinal tumor who underwent subtraction CTA, catheter DSA, and subsequent surgery between October 2015 and October 2021. Data regarding qualitative and semiquantitative subtraction CTA parameters and conventional MRI signs were collected for comparison with tumor vascularity graded through catheter DSA. The diagnostic performance of qualitative CTA, quantitative CTA, and conventional MRI in assessing spinal tumor vascularity was analyzed. ResultsQualitative subtraction CTA was the best noninvasive imaging modality in terms of diagnostic performance (area under the receiver operating characteristic curve [AUROC], 0.95). Quantitative CTA was relatively inferior (AUROC, 0.87). MRI results had low reliability (AUROC, 0.51 to 0.59). Intratumoral hemorrhage and prominent foraminal venous plexus were found to be the specific signs for hypervascularity (specificity 93.2%). ConclusionsQualitative subtraction CTA offers the highest diagnostic value in evaluating spinal tumor vascularity, compared to quantitative CTA and MRI. Although conventional MRI may not be a reliable approach, certain MRI signs may have high specificity, which may be crucial for assessing spinal tumor vascularity.

ASPECT Score and Its Application to Vasospasm in Aneurysmal Subarachnoid Haemorrhage: a Case–Control Study

Delayed cerebral ischaemia (DCI) is a significant complication of aneurysmal subarachnoid haemorrhage (aSAH) and is strongly associated with poorer outcome. The Alberta Stroke Program Early Computer Tomography (ASPECT) score is an established scoring tool, used in acute ischaemic stroke, to quantify early ischaemic changes on CT head scans. We aim to identify if ASPECT scoring correlates with functional outcome in DCI following aSAH. Retrospective case–control study. Inclusion criteria: admission to the Department of Neurosurgery at Leeds Teaching Hospitals NHS Trust (a tertiary neurosurgical centre in the United Kingdom) between 2014 and 2018, with a diagnosis of anterior circulation aneurysmal subarachnoid haemorrhage; as confirmed by initial CT scan and subsequent CT angiography or catheter digital subtraction angiography. Cases were those who developed DCI (n = 43) and controls were randomly selected from those who did not develop DCI (n = 46) but otherwise met the same inclusion criteria. The primary outcome measure was Glasgow Outcome Score (GOS): assessed at discharge and 3 months. ASPECT scores were calculated from non-contrast CT head scans by three researchers blinded to each other and clinical outcome. Spearman’s rank correlation was used to calculate correlation between ASPECT scores and GOS. ASPECT score positively correlated with GOS in the cases both at discharge (Spearman rho 0.436, p = 0.003) and at 3 months (Spearman rho 0.431, p = 0.004). When corrected for Fisher grading, the adjusted odds ratio of having a high GOS with a low ASPECT score at discharge was OR 0.74 (95% CI 0.61–0.94, p = 0.003), and 3 months OR 0.73 (95% CI 0.59–0.91, p = 0.005). ASPECT score significantly correlates with clinical outcome in DCI post aSAH, even after correcting for Fisher grade. ASPECT scoring may identify patients at risk of poor outcome following DCI and represents a quick and reliable tool that aids in clinical decision-making and prognostication.

T2 Hypointense Schwannoma Masquerading As A Vascular Lesion: A Case Report.

Spinal schwannomas are rare nerve root tumors that typically produce subtle symptoms from nerve root compression. These tumors are known to be heterogeneously hyperintense on T2-weighted MRI and avidly enhance with contrast. However, here we describe an L5 spinal schwannoma in a 66-year-old woman that was hypointense on T2-weighted imaging with other radiographic findings more closely aligning with a vascular lesion. The neuroradiologic characteristics on MRI, time resolved MR angiography, and catheter digital subtraction angiography are presented. The patient underwent a full workup for possible dural arteriovenous fistula and thrombosed venous varix before the nerve sheath tumor was discovered intraoperatively and confirmed as a schwannoma on histopathology.

Reversible cerebral vasoconstriction syndrome: A narrative review for emergency clinicians.

Reversible Cerebral Vasoconstriction Syndrome (RCVS) is a rare cause of severe headache that can mimic other causes of sudden, severe headache and result in frequent emergency department (ED) visits. This narrative review provides an evidence-based update concerning the presentation, evaluation, and management of RCVS for the emergency clinician. RCVS can present as recurrent, severe headaches that may be maximal in onset, known as a thunderclap headache. Distinguishing from other causes of thunderclap headache such as aneurysmal subarachnoid hemorrhage, cerebral venous thrombosis, and posterior reversible encephalopathy syndrome is challenging. Risk factors for RCVS include use of vasoactive substances, exertion, coughing, showering, sexual activity, and cervical artery dissection. Diagnosis relies on clinical features and imaging. Cerebral catheter digital subtraction angiography (DSA) is considered the gold standard imaging modality; however, computed tomography angiography or magnetic resonance angiography are reliable non-invasive diagnostic modalities. Treatment focuses on avoiding or removing the offending agent, administration of calcium channel blockers such as nimodipine, and reversing anticoagulation if bleeding is present. Although most cases have a benign course and resolve within 3months, focal subarachnoid hemorrhage, intracerebral hemorrhage, permanent neurologic disability, or death can occur in a minority of cases. Diagnosis and appropriate management of RCVS can be aided by understanding key aspects of the history and examination. The emergency clinician can then obtain indicated imaging, confirming the diagnosis and allowing for appropriate management.

Fluoroscopy, CT, and MR imaging characteristics of a novel primarily bioresorbable flow-diverting stent for aneurysms.

Five to ten percent of the global population have unruptured intracranial aneurysms, and ruptured brain aneurysms cause approximately 500,000 deaths a year. Flow-diverting stent treatment is a less invasive intracranial aneurysm treatment that induces aneurysm thrombosis. The imaging characteristics of a novel primarily bioresorbable flow-diverting stent (BFDS) are assessed in comparison to the leading metal stent using fluoroscopy, CT, and MRI. X-ray/fluoroscopic images of stents were taken using a human cadaveric skull model. CT and MRI were acquired using silicone flow models of residual aneurysms. Images were analyzed with Likert scales in anonymous surveys by neurointerventionalists. Quantitative measurements of radiographic density (CT) and artifact boundary size (CT & MRI) were also obtained. Visibility of the BFDS on X-ray was less than the metal stent but deemed adequate for deployment and intraprocedural assessment. The metal stent was more radiopaque than the BFDS on CT, but qualitative assessment was not significantly different for the two stents. MRI imaging was significantly better using the BFDS in terms of overall artifact and intraluminal assessment. The BFDS has adequate visualization on X-ray/fluoroscopy and should be clinically acceptable for fluoroscopic deployment. On MRI, there is less quantitative artifact as well as overall improved qualitative assessment that will allow for more detailed non-invasive imaging follow-up of treated aneurysms, potentially reducing the need for digital subtraction catheter angiography.

Inner diameters of the normal carotid arteries measured using three-dimensional digital subtraction catheter angiography: a retrospective analysis

PurposeTo obtain normal ranges for the inner diameters of the carotid arteries.MethodsThis retrospective analysis included consecutive patients with disease-free carotid arteries who had undergone 3D-DSA at two hospitals in Nanning, Guangxi, between March 2013 and March 2018. Demographic and clinical characteristics, including Essen Stroke Risk Score (ESRS), were extracted from the medical records. The 3D-DSA data were used to calculate the inner diameters of the carotid arteries.ResultsThe analysis included 1182 patients (837 males) aged 58.81 ± 11.02 years. The inner diameters of the proximal carotid sinus (CS), CS bulge, distal CS, and common carotid artery (CCA) were larger on the right than on the left (P < 0.05). The inner diameters of the proximal CS, CS bulge, distal CS, and CCA on both sides were larger for males than females (P < 0.05). The inner diameters of the proximal CS, CS bulge, and distal CS on both sides were smaller for patients aged > 65 years than for patients aged ≤ 55 years (P < 0.05). Right CCA inner diameter did not vary with age, whereas left CCA inner diameter was larger for patients aged > 55 years than for patients aged ≤ 45 years (P < 0.05). The inner diameters of the proximal CS, CS bulge, and distal CS on both sides were smaller for patients with ESRS ≥ 3 than those with ESRS < 3 (P < 0.05).ConclusionThis study provides reference values for the internal diameters of normal carotid arteries. Carotid artery diameters varied with side, sex, and age.

Preservation of the Lenticulostriate Arteries During Insular Glioma Resection.

Insular gliomas represent 25% and 10% of low- and high-grade gliomas, respectively. Their resection proves challenging due to the intimate involvement of eloquent parenchyma and the lenticulostriate arteries (LSAs), limiting facility of achieving maximal safe resection. The majority of postoperative deficits following insular glioma resection is attributed to compromise of the LSAs. It is contemporaneously critical and challenging to preserve these vessels, given they are numerous and small, with an intraparenchymal course hidden from direct visualization during the operative intervention. A lesser degree of medially directed displacement of the LSAs predicts tumoral encasement of these vessels, which portends a decreased likelihood for achieving a gross total resection and increased probability of postoperative morbidity. Preservation of these vessels thus requires knowledge of their location during the entirety of the insular glioma resection and is facilitated by pre- and intra-operative imaging. Intraoperative real-time tracking, however, may prove rather challenging, especially with transcortical access. Conventional catheter digital subtraction angiography, computed tomographic angiography, magnetic resonance imaging and angiography, and three-dimensional ultrasound powered Doppler have proven effective modalities in assessing lenticulostriate position, and their use facilitates a greater extent of resection while minimizing the attendant morbidity consequent to LSA injury.

The Effect of Vascular Segmentation Methods on Stereotactic Trajectory Planning for Drug-Resistant Focal Epilepsy: A Retrospective Cohort Study

BackgroundStereotactic neurosurgical procedures carry a risk of intracranial hemorrhage, which may result in significant morbidity and mortality. Vascular imaging is crucial for planning stereotactic procedures to prevent conflicts with intracranial vasculature. There is a wide range of vascular imaging methods used for stereoelectroencephalography (SEEG) trajectory planning. Computer-assisted planning (CAP) improves planning time and trajectory metrics. We aimed to quantify the effect of different vascular imaging protocols on CAP trajectories for SEEG.MethodsTen patients who had undergone SEEG (95 electrodes) following preoperative acquisition of gadolinium-enhanced magnetic resonance imaging (MR + Gad), magnetic resonance angiography and magnetic resonance angiography (MRV + MRA), and digital subtraction catheter angiography (DSA) were identified from a prospectively maintained database. SEEG implantations were planned using CAP using DSA segmentations as the gold standard. Strategies were then recreated using MRV + MRA and MR + Gad to define the “apparent” and “true” risk scores associated with each modality. Vessels of varying diameter were then iteratively removed from the DSA segmentation to identify the size at which all 3 vascular modalities returned the same safety metrics.ResultsCAP performed using DSA vessel segmentations resulted in significantly lower “true” risk scores and greater minimum distances from vasculature compared with the “true” risk associated with MR + Gad and MRV + MRA. MRV + MRA and MR + Gad returned similar risk scores to DSA when vessels <2 mm and <4 mm were not considered, respectively.ConclusionsSignificant variability in vascular imaging and trajectory planning practices exist for SEEG. CAP performed with MR + Gad or MRV + MRA alone returns “falsely” lower risk scores compared with DSA. It is unclear whether DSA is oversensitive and thus restricting potential trajectories.

Treatment of a Fusiform Anterior Cerebral Artery Aneurysm by Remodeling the Circle of Willis with Flow Diversion: A Novel Technical Note

Fusiform aneurysms are challenging lesions to manage given their poorly understood natural history and lack of a distinct neck. Historically, they have been treated surgically but endovascular management has recently evolved as a viable alternative. In this case, we describe a novel flow diversion technique for treatment of a fusiform anterior cerebral artery (ACA) aneurysm by jailing the compromised parent vessel obtaining endovascular aneurysm trapping. A 25-year-old man underwent brain magnetic resonance imaging and magnetic resonance angiography for workup of a headache, which revealed a fusiform right ACA A1 segment aneurysm. The patient subsequently underwent catheter digital subtraction angiography, which confirmed a 9× 5.5 mm fusiform right ACA A1 segment aneurysm. The patient elected to undergo endovascular treatment. A Pipeline Embolization Device (Medtronic, Dublin, Ireland) was placed from the right anterior cerebral artery to the right middle cerebral artery, thereby jailing the right ACA A1 segment. At 6-month follow-up, the patient was asymptomatic and his headache had resolved. An angiogram was obtained, showing patency of the Pipeline Embolization Device and near complete occlusion of the right ACA A1 segment. The right ACA A2 segment remained patent via collateral flow through the anterior communicating artery. These findings were confirmed on magnetic resonance imaging. The patient remained asymptomatic for the duration of the follow-up. This case illustrates the efficacy of the Pipeline Embolization Device for treatment of a fusiform anterior circulation aneurysm via remodeling the circle of Willis.

Accuracy of Doppler Ultrasonography in Assessment of Lower Extremity Peripheral Arterial Diseases

Doppler ultrasound scan is a non-invasive, cheap and convenient tool and it complements angiography, Computed tomography angiography (CTA), magnetic resonance angiography (MRA) and catheter digital subtraction angiography (DSA) in screening, diagnosis, treatment and follow-up of peripheral vascular diseases. Symptoms of peripheral vascular diseases are becoming more common due to rise in incidence of diseases and risk factors (diabetes mellitus, dyslipidemias, smoking, sedentary lifestyle). Due to limited availability of highly specific tools such as CT angiography, magnetic resonance angiography (MRA) and DSA (digital subtraction angiography) in many developing countries, doppler ultrasound is gaining more importance. Early determination of peripheral arterial diseases is beneficial in prevention of complications as severity increases may cause intermittent claudication, pain, tissue loss, including ulceration and gangrene (as the diseases progresses) and early management of arteriosclerosis will be beneficial to prevent these complications.

Advances in Axial Imaging of Peripheral Vascular Disease

Peripheral artery disease (PAD) has become increasingly common in the US patient population and can be a highly symptomatic and significant source of morbidity. When PAD is suspected, the first-line screening study that is obtained is typically a noninvasive evaluation that includes the ankle brachial index (ABI). Following a positive screening study, invasive catheter digital subtraction angiography (DSA) has been historically used to image the peripheral artery system and still remains the gold standard. However, newer developments in axial imaging including computed tomography angiography (CTA) and magnetic resonance angiography (MRA) have in large part supplanted DSA for imaging the peripheral artery system in clinical practice. Benefits of CTA include rapid noninvasive acquisition, wide availability, high spatial resolution, and the ability to generate isotropic datasets on 64-detector row and higher CT scanners, thereby allowing for multiplanar 3D reformatting. Drawbacks of CTA include the exposure to both iodinated contrast and ionizing radiation, although the radiation dose exposure is lower than for DSA, and newer techniques such as using low tube voltage and rapid acquisition times allow for lower contrast doses. The presence of vascular calcification also limits the evaluation of small distal arteries using CTA, although the development of dual-energy CT techniques has significantly addressed this issue. Benefits of MRA include the avoidance of exposure to ionizing radiation and high diagnostic accuracy, while drawbacks include limited availability and increased cost along with the risk of nephrogenic systemic fibrosis that is associated with gadolinium-based contrast agents, although the latter can be mitigated by using newer non-contrast MR angiography techniques. Future technical advances in CT and MR hardware and software and MR pulse sequences will likely lead to the broader applicability and increased accuracy of noninvasive axial imaging in the evaluation of patients with peripheral artery disease.

Clinical and doppler ultrasound evaluation of peripheral arterial diseases in Kano, North-western Nigeria.

Doppler ultrasound scan is a non-invasive and cheap tool that complements the roles of computed tomography, magnetic resonance imaging and catheter digital subtraction angiography in the screening, diagnosis and follow up of vascular diseases. In this study, we evaluated and described the findings of the Doppler ultrasound of the peripheral arteries performed at Aminu Kano Teaching Hospital (AKTH), Kano, Nigeria. All the findings of peripheral arterial Doppler ultrasound examinations performed at AKTH during a period of 18 months (from February 2012 to July 2013) were reviewed. All examinations were done using 7.5 MHz linear transducer connected to Mindary Digital Ultrasound Imaging System (Model DC-6; Shenzhen Mindray Biomed Electronics, Shenzhen, China). A 3.5 MHz convex transducer of the same machine was used in obese patients and those with severe subcutaneous oedema. The findings of 50 males and 28 females were reviewed. Their mean age was 55.8 ΁ 17.9 years. Diabetic foot disease, intermittent claudication, gangrene and limb swellings were the most common indications for arterial Doppler examination of the lower limbs, constituting 32.1%, 20.5%, 16.7% and 15.4%, respectively. Significant luminal stenosis, total luminal occlusion and loss of arterial resistance were the most frequent findings, constituting 29%, 26.9% and 7.7%, respectively. Femoro-popliteal and below the knee arteries were commonly involved by these abnormalities. Arrhythmia, increased intimal media thickness and wall calcifications were the common compounding findings while diabetes and hypertension were frequently associated clinical problems of these patients. Doppler ultrasound has a high diagnostic yield in depicting abnormalities in patients with clinical features of peripheral arterial disease.

Indocyanine Green Videoangiography and Intraoperative Catheter Digital Subtraction Angiography in the Treatment of Intracranial Aneurysms: A Consecutive Series of 235 Cases

Background The introduction of indocyanine green videoangiography (ICGV) has impacted significantly the practice of operative microneurosurgery over the past decade. Several clinical studies have compared the use of ICGV to conventional catheter intraoperative digital subtraction angiography (DSA) during aneurysm surgery. We describe our experience with the combined use of ICGV and DSA in this setting. Material &amp; Methods From January 2010 to December 2012, we performed both ICGV and intraoperative DSA in 235 consecutive aneurysm surgeries. Immediately after clip placement, ICGV was performed; if a problem was identified, the clip was removed and then repositioned or additional clips were added and ICGV repeated. Once the ICGV appearance was acceptable, DSA was then performed by an interventional neuroradiologist through a femoral arterial sheath that was placed either immediately preoperatively or during surgery. The number of cases in which ICGV as well as subsequent DSA resulted in clip repositioning or additional clip placement was assessed. Results Diagnostic images were obtained using ICGV in 230 of 235 cases and using DSA in 234 of 235 cases. After aneurysm clipping, ICGV resulted in clip removal and repositioning in seven cases when poor distal flow was encountered and the addition of extra clips in six cases to address clear residual aneurysm filling. When ICGV appeared satisfactory, DSA then resulted in clip repositioning in four instances of parent artery stenosis and the addition of extra clips in five cases of large, giant, or atheromatous aneurysms when additional filling not seen with ICGV was detected. Overall, ICGV resulted in a change in 13 cases, and then subsequent DSA resulted in a change in an additional nine cases. Our combined paradigm thus effected a change in the surgery in a total of 22 cases (9.3%). Conclusion In our experience, ICGV carries the distinct advantages of rapid feedback of information and excellent visualization of local perforators, while DSA provides optimal visualization of residual aneurysm and non-flow-limiting parent artery stenosis. Their combined use may provide optimal information to microsurgeons who continue to operate on intracranial aneurysms.

Developmental Venous Anomalies (DVA): What Are They Really?

The aim of this paper is to analyse the pathophysiology of 3 DVA cases from our institution, review the literature and propose a classification of these lesions. The pathophysiology of DVAs were analysed with CT perfusion (CTP), 4 dimensional dynamic computed tomography angiography (4D CTA) and catheter digital subtraction angiography. Symptomatic DVAs may be caused by associated lesions and compression of neural structures by the DVAs. The imbalance between the inflow and outflow of these lesions, including venous ischaemia, has also been postulated as a cause. Our analysis showed that increased cerebral blood flow (CBF) and cerebral blood volume (CBV) and decreased mean transit time (MTT) and time to peak (TTP) were found in DVAs with micro arteriovenous shunting. DVAs without shunting had raised MTT and TTP instead. We postulate that the arteriovenous shunting resulted in arterial steal and chronic hypoxia which could be a pathophysiological mechanism for symptomatic DVAs. CTP and 4D CTA are effective non invasive tools to study DVAs. A classification is proposed.

Arterial diameters on catheter and computed tomographic angiography

Background The diagnosis of cerebral vasospasm is hampered by lack of an accurate, noninvasive test. Computed tomographic angiography (CTA) may be useful but the correlation between arterial diameters determined from catheter digital subtraction angiography (DSA) and CTA over a range of artery sizes would need to be determined to show this. The purpose of this study was to determine the correlation between artery diameters measured on DSA and multidetector CTA. Methods Two hundred forty artery diameters were measured in DSA and CTA from 46 patients who underwent both studies within 12 hours of each other. Axial cross section, maximum intensity projection, and volume-rendered images were measured and compared by linear correlation. Two independent readers measured CTA diameters to determine interobserver variability by linear correlation. Values also were categorized and compared by χ 2 and κ statistics. Analysis was repeated with unmeasurable arteries assigned a value of 0. Results There were significant correlations between arterial diameters measured on DSA and those from CTA measured by any method ( R 2 ranging from 0.45 to 0.76, P < .0001), although there was a tendency for the slope of this relationship to be less than 1, indicating underestimation of diameter of large and overestimation of diameter of small arteries with CTA. Computed tomographic angiography diameters also correlated significantly between the 2 reviewers with higher values often when unmeasureable arteries were assigned a value of 0 ( κ = 0.23-0.55, P < .0001). Conclusion Arterial diameters measured on multidetector CTA correlate well with those determined from DSA and should permit use of CTA for quantitative study of cerebral vasospasm and other conditions requiring accurate measurement of arterial diameters. The limitation of CTA remains the inability to measure some arteries due to artifact.

Symptomatic Moyamoya disease: Clinical features and outcome after indirect bypass surgery in four French adults

Background There are a few reports of moyamoya disease (MMD) in the European Caucasian adult population. We present the clinical manifestations, the neuroradiological aspects, the treatment, and the outcome after surgical revascularization of four French patients with MMD. Patients and methods We identified four adults (age >18 years; three women and one man) with MMD who underwent digital subtraction catheter angiography at our institution from 1997 through 2006. The median age at symptom onset was 35 years (range, 22 to 41 years). The initial clinical presentation was intracerebral hemorrhage in three patients and ischemic stroke in one patient. Results Three patients underwent bilateral surgical revascularization and one patient underwent unilateral surgical revascularization. All patients underwent the same surgical revascularization procedure (encephalo-duro-arterio-myo-synangiosis). The mean (+/− SD) period of follow-up after diagnosis of MMD was 6 years and 9 months (+/− 3 years and 5 months). No patient experienced any recurrent hemorrhagic or ischemic stroke. No perioperative stroke occurred. No patient was severely disabled or unable to walk. Three patients out of four were employed. Conclusion Our data suggest safety and a potential benefit of surgical revascularization (indirect bypass surgery) in European adult patients with symptomatic MMD. Further long-term prospective multicenter studies are needed. The establishment of a registry would be useful in order to accumulate data in large numbers of European patients with this uncommon disease.

Confirmation of t1-bright vein of galen aneurysm spontaneous thrombosis by subtraction magnetic resonance venography: a case report

Spontaneous thrombosis of a vein of Galen aneurysmal malformation (VOGM) is rare. We describe a 2-month-old patient with a patent VOGM and hydrocephalus, also confirmed patent at 6 months, but with subsequent lack of filling on preembolization catheter digital subtraction angiography (DSA) at 9 months' age. Due to the presence of T1- and T2-bright signal, noncontrast T1-weighted images (T1WI), T2-weighted images (T2WI), two-dimensional (2D) time-of-flight (TOF) magnetic resonance venography (MRV), and postcontrast T1WI were ambiguous for patency. However, subtracting the pre- from the postcontrast MRV images confirmed closure compared to subtracted images at 6 months' age. The factors contributing to thrombosis were likely a combination of a disproportionately small straight sinus, ventriculostomy, and contrast medium from DSA.

Pelvic digital subtraction catheter angiography—Are routine oblique projections necessary?

The oblique projection is used widely in imaging of the lower vascular tree. Much of the evidence justifying the oblique projection is anecdotal. This study compares the sensitivity of the anteroposterior (AP) projection alone in lower limb vascular catheter angiography to that combined with the oblique projection. 110 digitally subtracted angiograms were analysed initially on AP and subsequently on oblique views. Oblique imaging increases confidence, demonstrates stenoses not seen on AP and changes the diagnosis. This supports the use of the oblique projection in lower limb vascular interventional imaging.

Lessons from the Diagnosis and Treatment of Spontaneous Vertebral Arterial Dissection

A 36-year-old man presented a sudden left occipital headache and right limb weakness after tooth-brushing. Conventional catheter digital subtraction angiography (DSA) showed a left VA occlusion at the crotch of the posterior inferior cerebellar artery. Four days later, the patient got worse. The angiogram showed the left vertebral artery had reopened and the basilar trunk occluded above the AICA. He died two days later and autopsy demonstrated a dissection of the basilar arteries. Based on the autopsy data from the patient in this study, we suggest that the BA dissection might be due to left VA dissection, and placing a stent on the juncture between the uninjured VA and the basilar trunk might be an effective method to prevent fatal BA occlusion.

The role of time-resolved 3D contrast-enhanced MR angiography in the assessment and grading of cerebral arteriovenous malformations

Purpose To assess the role of three-dimensional (3D) contrast-enhanced, time-resolved MR angiography (CE TR MRA) in patients with intracranial arteriovenous malformations (AVMs). Methods We studied 12 patient with intracranial AVMs on a 3.0 T MR imaging system (Magentom TIM Trio, Siemens Medical Solutions, Erlangen, Germany) using 3D CE TR MRA with autocalibrating partially parallel acquisitions and echo sharing schemes, which provided temporal resolution of 0.58 or 1.7 s and near isotropic voxels. We qualitatively assessed image quality of the 3D CE TR MRA and compared the grading of the AVMs based on modified Spetzler–Martin system for 3D CE TR MRA and catheter digital subtraction angiography (DSA). Results CE TR MRA provided good quality images in the 3 standard orthogonal planes, and good arterial-venous separation in all cases. All AVMs were correctly graded by CE TR MRA when compared with DSA. 3D CE TR MRA provides a non-invasive alternative to DSA for the evaluation of cerebral AVMs.