Gabriela Spilberg

Reduction of Coil Mass Artifacts in High-Resolution Flat Detector Conebeam CT of Cerebral Stent-Assisted Coiling

BACKGROUND AND PURPOSE: Developments in flat panel angiographic C-arm systems have enabled visualization of both the neurovascular stents and host arteries in great detail, providing complementary spatial information in addition to conventional DSA. However, the visibility of these structures may be impeded by artifacts generated by adjacent radio-attenuating objects. We report on the use of a metal artifact reduction algorithm for high-resolution contrast-enhanced conebeam CT for follow-up imaging of stent-assisted coil embolization. MATERIALS AND METHODS: Contrast-enhanced conebeam CT data were acquired in 25 patients who underwent stent-assisted coiling. Reconstructions were generated with and without metal artifact reduction and were reviewed by 3 experienced neuroradiologists by use of a 3-point scale. RESULTS: With metal artifact reduction, the observers agreed that the visibility had improved by at least 1 point on the scoring scale in >40% of the cases (κ = 0.6) and that the streak artifact was not obscuring surrounding structures in 64% of all cases (κ = 0.6). Metal artifact reduction improved the image quality, which allowed for visibility sufficient for evaluation in 65% of the cases, and was preferred over no metal artifact reduction in 92% (κ = 0.9). Significantly higher scores were given with metal artifact reduction (P < .0001). CONCLUSIONS: Although metal artifact reduction is not capable of fully removing artifacts caused by implants with high x-ray absorption, we have shown that the image quality of contrast-enhanced conebeam CT data are improved drastically. The impact of the artifacts on the visibility varied between cases, and yet the overall visibility of the contrast-enhanced conebeam CT with metal artifact reduction improved in most the cases.

Closed-cell stent for coil embolization of intracranial aneurysms: clinical and angiographic results

Because recanalization is observed in 20–40% of endovascularly treated aneurysms, these authors report their experience using a closed-cell stent. They treated 161 wide-neck ruptured or unruptured aneurysms with the device and found a nearly 5% death rate and a 3.5% incidence of neurologic deficits. Of the ones available for follow-up, 10% of patients showed recanalization and 6% required retreatment. In-stent stenosis was seen in only 1 instance. Treatment of ruptured aneurysms and premature termination of antiplatelet medication were associated with increased morbidity and mortality but overall these stents were considered to be safe and effective. BACKGROUND AND PURPOSE: Recanalization is observed in 20–40% of endovascularly treated intracranial aneurysms. To further reduce the recanalization and expand endovascular treatment, we evaluated the safety and efficacy of closed-cell SACE. MATERIALS AND METHODS: Between 2007 and 2010, 147 consecutive patients (110 women; mean age, 54 years) presenting at 2 centers with 161 wide-neck ruptured and unruptured aneurysms were treated by using SACE. Inclusion criteria were wide-neck aneurysms (>4 mm or a dome/neck ratio ≤2). Clinical outcomes were assessed by the mRS score at baseline, discharge, and follow-up. Aneurysm occlusion was assessed on angiograms by using the RS immediately after SACE and at follow-up. RESULTS: Eighteen aneurysms (11%) were treated following rupture. Procedure-related mortality and permanent neurologic deficits occurred in 2 (1.4%) and 5 patients (3.4%), respectively. In total, 7 patients (4.8%) died, including 2 with reruptures. Of the 140 surviving patients, 113 (80.7%) patients with 120 aneurysms were available for follow-up neurologic examination at a mean of 11.8 months. An increase in mRS score from admission to follow-up by 1, 2, or 3 points was seen in 7 (6.9%), 1 (1%), and 2 (2%) patients, respectively. Follow-up angiography was performed in 120 aneurysms at a mean of 11.9 months. Recanalization occurred in 12 aneurysms (10%), requiring retreatment in 7 (5.8%). Moderate in-stent stenosis was seen in 1 (0.8%), which remained asymptomatic. CONCLUSIONS: This series adds to the evidence demonstrating the safety and effectiveness of SACE in the treatment of intracranial aneurysms. However, SACE of ruptured aneurysms and premature termination of antiplatelet treatment are associated with increased morbidity and mortality.

The Effect of Intracranial Stent Implantation on the Curvature of the Cerebrovasculature

BACKGROUND AND PURPOSE: Recently, the use of stents to assist in the coiling and repair of wide-neck aneurysms has been shown to be highly effective; however, the effect of these stents on the RC of the parent vessel has not been quantified. The purpose of this study was to quantify the effect of intracranial stenting on the RC of the implanted artery using 3D datasets. MATERIALS AND METHODS: Twenty-four patients receiving FDA-approved neurovascular stents to support coil embolization of brain aneurysms were chosen for this study. The stents were located in the ICA, ACA, or MCA. We analyzed C-arm rotational angiography and contrast-enhanced cone beam CT datasets before and after stent implantation, respectively, to ascertain changes in vessel curvature. The images were reconstructed, and the vessel centerline was extracted. From the centerline, the RC was calculated. RESULTS: The average implanted stent length was 25.4 ± 5.8 mm, with a pre-implantation RC of 7.1 ± 2.1 mm and a postimplantation RC of 10.7 ± 3.5 mm. This resulted in a 3.6 ± 2.7 mm change in the RC due to implantation (P < .0001), more than a 50% increase from the pre-implantation value. There was no difference in the change of RC for the different locations studied. The change in RC was not impacted by the extent of coil packing within the aneurysm. CONCLUSIONS: The implantation of neurovascular stents can be shown to have a large impact on the RC of the vessel. This will lead to a change in the local hemodynamics and flow pattern within the aneurysm.

Pulmonary amyloidosis with calcified nodules and masses - a six-year computed tomography follow-up: a case report

IntroductionPulmonary amyloidosis is an uncommon disease, characterized by extracellular deposition of fibrillary protein in the lungs. It appears in three forms: tracheobronchial, nodular pulmonary, and alveolar septal. There are few reports of long-term observation of primary pulmonary amyloidosis.Case presentationWe present the case of a 47-year-old man who presented with fever, dyspnea, cough and hemoptysis. Chest radiograph and computed tomography revealed multiple pulmonary nodules and masses. The patient underwent open lung biopsy, which diagnosed pulmonary amyloidosis.ConclusionPulmonary nodular amyloidosis should be considered in the differential diagnosis of pulmonary nodules or masses.

Wingspan experience in the treatment of symptomatic intracranial atherosclerotic disease after antithrombotic failure.

Background and purpose Intracranial stenting with the Wingspan system has been used as a revascularization strategy in symptomatic patients with intracranial atherosclerotic disease (ICAD). The latest results of the Stenting versus Aggressive Medical Therapy for Intracranial Artery Stenosis (SAMMPRIS) trial challenge this approach. Our experience in the treatment of symptomatic ICAD with the Wingspan system is reported. Materials and methods Patients who underwent stenting for symptomatic ICAD were included in the analysis. Demographic data, periprocedural complications, long term radiological and clinical outcomes are reported. Results 46 lesions were treated in 45 patients. 13 patients (29%) presented with a transient ischemic attack and 32 (71%) with a stroke. 43 patients (95.5%) failed antithrombotic therapy at presentation. One (2%) symptomatic periprocedural (24 h) complication occurred. The 30 day incidence of stroke and vascular death was 6.6%—a fatal hemorrhagic stroke and two non-fatal hemorrhagic strokes. In-stent stenosis (≥50%) was seen in nine (42.8%) lesions, two were symptomatic. Conclusions This cohort of patients with symptomatic ICAD who failed antithrombotic medications benefited from angioplasty and stenting with the Wingspan system.

Endovascular treatment of tentorial dural arteriovenous fistulae.

Tentorial dural arteriovenous fistula (DAVF) is a rare vascular disease, which accounts for less than 4% of all cases of intracranial DAVF. Because of the high risk of intracranial hemorrhage, patients with tentorial DAVF need aggressive treatment. Management approaches are still controversial, and endovascular treatment has emerged as an effective alternative. In the current work, we describe our experience with the endovascular approach in the treatment of these deep and complex DAVF of the tentorium. Eight patients were treated between January 2006 and July 2009. Six patients (75%) presented with intracranial hemorrhage related to the DAVF rupture. Four patients (50%) had subarachnoid bleeding and two had intraparenchymal hematoma. Endovascular treatment was performed via the transarterial route alone in five cases (62.5%), by the transvenous approach in two cases (25.0%) and in a combined procedure using both arterial and venous routes in one patient (12.5%). Complete obliteration of the fistula was achieved in all cases. The outcome at 15 months was favorable (modified Rankin scale 0–3) in seven (87.5%) patients. Complete cure of the lesion was confirmed in these cases. This paper reports on the effectiveness of endovascular treatment in tentorial DAVF management. The choice of the venous versus the arterial approach is determined by regarding different anatomical dispositions.

Temporal Evolution of Susceptibility Artifacts from Coiled Aneurysms on MR Angiography: An In Vivo Canine Study

BACKGROUND AND PURPOSE: Intracranial aneurysms treated by coiling have a risk for recurrence, requiring surveillance imaging. MRA has emerged as an attractive technique for postcoiling aneurysm imaging. Previous research has evaluated MR imaging artifacts of the coil mass in vitro. Our aim in this study was to evaluate MR imaging artifacts of coiled aneurysms in vivo with time. MATERIALS AND METHODS: Four sidewall aneurysms were created in each of 4 dogs. Aneurysms were embolized receiving only 1 type of coils. After embolization, the animals were transferred to MR imaging, which included axial 3D TOF MRA (TEs, 3.5, 5, and 6.9 ms), phase-contrast MRA, and coronal CE-MRA. MR imaging studies were repeated at 1, 4, 6, 8, 14, and 28 weeks. We calculated an OEF: OEF = VA/VCM, where the numerator represents the volume of the MR imaging artifacts and the denominator is the true volume of the coil mass measured by 3D RA. RESULTS: OEFs were largest immediately after embolization and showed a gradual decay until approximately 4 weeks, when there was stabilization of the size of the artifacts. By 4 weeks, there was mild coil compaction (average coil mass volume decrease of 7.8%); however, the OEFs decreased by 25% after 4 weeks (P < .001). CONCLUSIONS: MR imaging susceptibility artifacts change with time, being maximal in the postembolization setting and decaying until 4 weeks. The clinical implications of this study are that baseline MRA for comparison with future imaging should be acquired at a minimum of 1 week after the procedure.

Embolization of intra-axial hypervascular tumors with Onyx: report of three cases

Complete surgical resection of intra-axial hypervascular tumors located in the posterior fossa, in particular hemangioblastomas, may be challenging due to tumor location, mass effect and excessive bleeding. Embolization of these lesions can be done preoperatively or as a palliative measure in patients who are not surgical candidates. Preoperative embolization may reduce intraoperative blood loss, shorten surgical time and increase the chance of a complete resection. However, the safety and effectiveness of this procedure is still a matter of debate. Three cases of intra-axial hypervascular tumors in the posterior fossa (two confirmed hemangioblastomas) that were embolized using a non-adhesive liquid embolic agent (Onyx) are reported.

Magnetic resonance findings of neurofibromatosis type 2: a case report

Neurofibromatosis type 2 is an inherited autosomal dominant syndrome, characterized by multiple neoplasms of the central and peripheral nervous system associated with ocular abnormalities. The most common tumor associated with the disease is the vestibulocochlear schwannoma (VIII cranial nerve), and as many as 10% of patients with this tumor have neurofibromatosis type 2. In this report we aim to present a 34-year-old male who was seen for bilateral hearing loss. During his workup, which included cranial computer tomography, he was found to have multiple intracranial masses. Cranial and whole spine magnetic resonance imaging showed bilateral vestibulocochlear schwannoma, multiple meningiomas, and one intramedullary tumor. Based on clinical and imaging findings the diagnostic of neurofibromatosis type 2 was made.

Superior ophthalmic vein puncture: an alternative approach to treat complex cavernous sinus fistulae

. Among the most serious symptoms are visual loss, and consequences of brain hemorrhage. The most commonly performed endovascular treatment con-sists in embolization through a venous approach by the in-ferior petrosal sinus and occlusion of the cavernous sinus with coils. Not always a conventional route is feasible, im-posing alternative routes. We describe two cases of CCF treated with technical success using the superior ophthal-mic vein (SOV) as a route to reach the cavernous sinus. CaSeS