Faculty Bibliography

BACKGROUND AND PURPOSE: Treatment options for nonsaccular posterior cerebral artery aneurysms include a range of surgical and endovascular reconstructive and deconstructive methods. However, no truly satisfactory treatment option is available to date for lesions arising from the P1 and P2 segments. The purpose of the present case series is to investigate both the efficacy and safety of the Pipeline Embolization Device in treating these challenging aneurysms. MATERIALS AND METHODS: We present a series of 6 consecutive patients who underwent endoluminal reconstruction with the Pipeline Embolization Device for nonsaccular P1 or P2 segment aneurysms between January 2009 and June 2013. RESULTS: Aneurysm location included the P1 segment in 2 patients and the P2 segment in 4 patients. Mean aneurysm diameter was 23 mm (range, 5-44 mm). Mean length of the arterial segment involved was 10 mm (range, 6-19 mm). Clinical presentation included mass effect in 4 patients and perforator stroke and subacute aneurysmal subarachnoid hemorrhage in 1 patient each. Endovascular reconstruction was performed by using 1 Pipeline Embolization Device in 5 patients and 2 overlapping Pipeline Embolization Devices in the remaining patient. Angiographic aneurysm occlusion was immediate in 1 patient, within 6 months in 4 patients, and within 1 year in the remaining patient. Index symptoms resolved in 4 patients and stabilized in the remaining 2. No new permanent neurologic sequelae and no aneurysm recurrence were recorded during the mean follow-up period of 613 days (range, 540-725 days). CONCLUSIONS: Endovascular reconstruction with the Pipeline Embolization Device for nonsaccular aneurysms arising from the P1 and P2 segments compares favorably with historical treatment options in terms of occlusion rate, margin of safety, and neurologic outcome.

ABSTRACT Purpose: Previous publications demonstrated that multi-detector-row computed tomography Angiograpy (MDCTA) can evaluate the carotid artery wall thickness (CAWT). The purpose of this work was to compare the asymmetry of CAWT between carotids in symptomatic and asymptomatic patients. Material and Methods: Sixty consecutive symptomatic (males 44; median age 64) and sixty asymptomatic sex- and age-matched patients, were analyzed by using a 40-detector-row CT system. CAWT was calculated for both carotids in each patient and the ratio between the thicker CAWT and the contra-lateral was calculated to obtain the ACAWT index. Bland-Altman, logistic regression and Receiver Operating Characteristic (ROC) curve analysis were calculated. Results. The Bland-Altman plot demonstrates a very good agreement between measurements with a mean difference value of 3.4% and 95% CI from -8% to 14.8% The ACAWT was significantly different between symptomatic and asymptomatic patients (with a P value of 0.0001). The ROC area under the curve was 0.742 (P = 0.001). Logistic regression model indicated that ACAWT, CAWT, stenosis degree and fatty plaques were independent variables associated with cerebrovascular symptoms (P value respectively 0.0108, 0.0231, 0.0002 and 0.013). Conclusion: Results of our study indicated that the index of asymmetry in the CAWT might be used as a further parameter to stratify the risk of symptoms related to carotid artery.

BACKGROUND AND PURPOSE: Endoluminal reconstruction with the Pipeline Embolization Device is an effective treatment option for select intracranial aneurysms. However, concerns for the patency of eloquent branch arteries covered by the Pipeline Embolization Device have been raised. We aimed to examine the patency of the anterior choroidal artery and clinical sequelae after ICA aneurysm treatment. MATERIALS AND METHODS: We prospectively analyzed all patients among our first 157 patients with ICA aneurysms treated by the Pipeline Embolization Device who required placement of at least 1 device across the ostium of the anterior choroidal artery. The primary outcome measure was angiographic patency of the anterior choroidal artery at last follow-up. Age, sex, type of aneurysm, neurologic examination data, number of Pipeline Embolization Devices used, relationship of the anterior choroidal artery to the aneurysm, and completeness of aneurysm occlusion on follow-up angiograms were also analyzed. RESULTS: Twenty-nine aneurysms requiring placement of at least 1 Pipeline Embolization Device (median = 1, range = 1-3) across the anterior choroidal artery ostium were identified. At angiographic follow-up (mean = 15.1 months; range = 12-39 months), the anterior choroidal artery remained patent, with antegrade flow in 28/29 aneurysms (96.5%), while 24/29 (82.7%) of the target aneurysms were angiographically occluded by 1-year follow-up angiography. Anterior choroidal artery occlusion, with retrograde reconstitution of the vessel, was noted in a single case. A significant correlation between the origin of the anterior choroidal artery from the aneurysm dome and failure of the aneurysms to occlude following treatment was found. CONCLUSIONS: After placement of 36 Pipeline Embolization Devices across 29 anterior choroidal arteries (median = 1 device, range = 1-3 devices), 1 of 29 anterior choroidal arteries was found occluded on angiographic follow-up. The vessel occlusion did not result in persistent clinical sequelae. Coverage of the anterior choroidal artery origin with the Pipeline Embolization Device, hence, may be considered reasonably safe when deemed necessary for aneurysm treatment.

BACKGROUND AND PURPOSE: The Circle of Willis (COW) is the main collateral system between the bilateral carotid systems and the posterior circulation. COW normal variants are encountered in up to 62% of subjects. We hypothesize that, in patients with carotid artery stenosis, the presence of COW variants is a risk factor for leukoaraiosis. MATERIALS AND METHODS: Forty-seven patients (mean age 72.1 +/- 9 years, males = 39) with carotid artery stenosis admitted for carotid endarterectomy were included and underwent an admission brain MRI/MRA. Two neuroradiologists evaluated the COW variants. FLAIR-leukoaraiosis lesion-volume was performed using a semiautomated segmentation technique. Mann-Whitney and Pearson correlations were conducted to identify the correlation between the FLAIR-leukoaraiosis lesion-volume and the COW variants. ROC analysis was performed to evaluate the AUC of FLAIR-leukoaraiosis lesion-volume and presence/absence of COW variants. RESULTS: Pearson correlation demonstrated that the leukoaraiosis lesion-volume is significantly associated with the COW variants number (rho = .358, P = .0215). When patients were dicotomized in two subgroups, with and without COW variants, the lesion-volume was significantly higher in the variants group (P = .0405). The ROC curve analysis showed an AUC of .688 (SE = .083, 95%CI = .525-.823) with a statistically significant P = .0225, between the presence of COW variants and the FLAIR-leukoaraiosis lesion-volume. CONCLUSION: The presence and the number of COW variants are associated with a higher leukoaraiosis volume in patients with significant internal carotid artery stenosis.

INTRODUCTION: Carotid artery dissection is an important cause of ischemic stroke in all age groups, particularly in young patients. The purpose of this work was to assess whether there is an association between the presence of an internal carotid artery dissection (ICAD) and the arterial tortuosity. METHODS: This study considered 124 patients (72 males and 52 females; median age 57 years) with CT/MR diagnosis of ICAD of the internal carotid artery were considered in this multi-centric retrospective study. The arterial tortuosity was evaluated and, when present, was categorized as elongation, kinking, or coiling. For each patient, both the right and left sides were considered for a total number of 248 arteries in order to have the same number of cases and controls. Fisher's exact test was applied to test the association between elongation, kinking, coiling, dissection, and the side affected by CAD. RESULTS: Fisher's exact test showed a statistically significant association between the ICAD and kinking (p = 0.0089) and coiling (p = 0.0251) whereas no statistically significant difference was found with arterial vessel elongation (p = 0.444). ICAD was more often seen on the left side compared to the right (p = 0.0001). These results were confirmed using both carotid arteries of the same patient as dependent parameter with p = 0.0012, 0.0129, and 0.3323 for kinking, coiling, and elongation, respectively. CONCLUSION: The presence of kinking and coiling is associated with ICAD.

Despite the increasing development and applications of iron imaging, the pathophysiology of iron accumulation in multiple sclerosis (MS), and its role in disease progression and development of clinical disability, is poorly understood. The aims of our study were to determine the presence and extent of iron in T2 visible lesions and gray and white matter using magnetic field correlation (MFC) MRI and correlate with microscopic white matter (WM) injury as measured by diffusion tensor imaging (DTI). This is a case-control study including a series of 31 patients with clinically definite MS. The mean age was 39 years [standard deviation (SD) = 9.55], they were 11 males and 20 females, with a disease duration average of 3 years (range 0-13) and a median EDSS of 2 (0-4.5). Seventeen healthy volunteers (6 males and 11 females) with a mean age of 36 years (SD = 11.4) were recruited. All subjects underwent MR imaging on a 3T scanner using T2-weighted sequence, 3D T1 MPRAGE, MFC, single-shot DTI and post-contrast T1. T2-lesion volumes, brain volumetry, DTI parameters and iron quantification were calculated and multiple correlations were exploited. Increased MFC was found in the putamen (p = 0.061), the thalamus (p = 0.123), the centrum semiovale (p = 0.053), globus pallidus (p = 0.008) and gray matter (GM) (p = 0.004) of MS patients compared to controls. The mean lesional MFC was 121 s-2 (SD = 67), significantly lower compared to the GM MFC (<0.0001). The GM mean diffusivity (MD) was inversely correlated with the MFC in the centrum semiovale (p < 0.001), and in the splenium of the corpus callosum (p < 0.001). Patients with MS have increased iron in the globus pallidus, putamen and centrum with a trend toward increased iron in all the brain structures. Quantitative iron evaluation of WM and GM may improve the understanding of MS pathophysiology, and might serve as a surrogate marker of disease progression.

PURPOSE: Cerebral microbleeds (CMBs) are small dot-like lesions appearing as hyposignals on gradient echo (GRE) T2* magnetic resonance (MR) sequences, whereas the leukoaraiosis (LA) indicates the presence of patchy areas of hypersignal on fluid-attenuated inversion recovery (FLAIR) MR sequences in the periventricular white matter. The purpose of this work was to evaluate the association between LA and CMBs. MATERIAL AND METHODS: Eighty-five consecutive (men 55; median age 64 years) patients were retrospectively analyzed using a 1.5 T system; CMBs were studied using a T2*-weighted GRE sequence and classified as absent (grade 1), mild (grade 2; total number of microbleeds, 1-2), moderate (grade 3; total number of microbleeds, 3-10), and severe (grade 4; total number of microbleeds, >10). LA was assessed with FLAIR MR sequences and was graded based on the European Task Force on Age-Related White Matter Changes as follows: 1 (no lesions), 2 (focal lesions > 5 mm), 3 (early confluent lesions), and 4 (diffuse involvement of an entire brain region). RESULTS: We considered 170 cerebral hemispheres. The prevalence of CMBs was 24.7% (42 of 170), whereas the prevalence of LA was 27.1% (46 of 170). A statistically significant correlation was observed between LA and CMBs (correlation rho = .495, P value = .001). Multiple logistic regression analysis showed an association between CMBs and cerebrovascular symptoms (P = .0023). CONCLUSION: Results of this study suggest an association between CMBs and LA. Moreover, we found that LA is associated with the presence of cerebrovascular symptoms.

BACKGROUND AND PURPOSE: The presence of a cortical erosion of the posterior wall or an epidural mass is commonly considered a contraindication to performing a vertebral augmentation, considering the perceived increased risk of an epidural cement leak. Our aim was to assess technical and clinical complications of vertebral augmentation procedures performed for pain palliation and/or stabilization of neoplastic lytic vertebral body lesions, with cortical erosion of the posterior wall, often associated with a soft-tissue epidural mass. MATERIALS AND METHODS: In 48 patients, we performed retrospective vertebral augmentation assessment on 70 consecutive levels with cortical erosion of the posterior wall, as demonstrated by preprocedural CT/MR imaging. An epidural mass was present in 31/70 (44.3%) levels. Cavity creation was performed with Coblation Wands before cement injection in 59/70 levels. Injection of high-viscosity polymethylmethacrylate was performed under real-time continuous fluoroscopic control. Postprocedural CT of the treated levels was performed in all cases. Clinical follow-up was performed at 1 and 4 weeks postprocedurally. RESULTS: In 65/70 (92.8%) levels, the vertebral augmentation resulted in satisfactory polymethylmethacrylate filling of the lytic cavity and adjacent trabecular spaces in the anterior half of the vertebral body. An epidural leak of polymethylmethacrylate occurred in 10/70 (14.2%) levels, causing radicular pain in 3 patients, which spontaneously resolved within 1 week in 2 patients, while 1 patient with a T1-T2 foraminal leak developed severe weakness of the intrinsic hand muscles and a permanent motor deficit. CONCLUSIONS: In our series of vertebral augmentation of neoplastic lytic vertebral lesions performed for palliation of pain and/or stabilization, we observed a polymethylmethacrylate epidural leak in only 14.2% of levels, despite the presence of cortical erosion of the posterior wall and an epidural mass, with an extremely low rate of clinical complications. Our data seem to justify use of vertebral augmentation in patients with intractable pain or those at risk for vertebral collapse.

Background: The correlation between AAA and carotid artery plaque is unknown and a common etiology and pathophysiology is suspected by some authors. The purpose of this work was to explore the association between the features of a) carotid artery plaque and b) abdominal aortic aneurysm (AAA) plaques using multi-detector-CT Angiography (MDCTA). Methods: Forty-eight (32 males; median age 72 years) patients studied using a 16-detectors CT scanner were retrospectively analyzed. A region of interest (ROI) > 2 mm² was used to quantify the HU value of the plaque by two readers independently. Inter-observer reproducibility was calculated and Pearson correlation analysis was performed. Results: The Bland-Altman plots showed the inter-observer reproducibility to be good. The Pearson correlation was 0.224 (95 % CI = 0.071 to 0.48), without statistically significant association between HU measured in the carotid artery plaque and in the AAA plaques (p = 0.138); after exclusion of the calcified plaques from the analysis, the rho values resulted 0.494 (95 % CI = 0.187 to 0.713) with a statistically significant association (p = 0.003). Conclusion: In this study, we found an association between the features of the non calcific carotid plaque and the features of AAA plaque