Abstract 48: High-Resolution Vessel Wall Imaging of Cryptogenic Stroke: A 7T MRI Study

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Jorge A Roa ◽  
Mario Zanaty ◽  
Daizo Ishii ◽  
Colin P Derdeyn ◽  
Girish Bathla ◽  
...  

Background: High-resolution vessel wall imaging (HR-VWI) has emerged as a useful tool for characterization of intracranial vasculopathic processes. HR-VWI allows better characterization of the arterial wall and may aid in the identification of atherosclerotic plaques, intra-arterial hemorrhages such as in the case of dissections and/or increased contrast enhancement such as in vasculitis. 7T HR-VWI may provide additional information in the identification of stroke mechanism in patients with cryptogenic stroke. Methods: Patients with cryptogenic stroke were prospectively imaged with a 7T scan. Strokes were determined to be cryptogenic after an extensive diagnostic work-up was completed. T1-weighted (pre- and post-contrast), T2-weighted, TOF and SWAN sequences were obtained. Demographic and clinical information was gathered from electronic medical charts. Results: Seventeen patients were included. Mean age was 57.8 ± 16.3 years-old, and 10 (58.8%) were women. HR-VWI determined the etiology of AIS in all subjects: 12 (70.6%) intracranial atherosclerotic disease (ICAD), 3 small-vessel disease and 2 arterial dissections. Inter-observer agreement was κ = 0.92. Plaque enhancement was identified in 14 cases, and intraplaque hemorrhage in 1 case of arterial dissection. In a patient with angiography suggestive of Moyamoya disease, HR-VWI determined the presence of diffuse ICAD as the underlying cause of stroke. Conclusion: HR-VWI may be used in patients with cryptogenic stroke to identify the etiologic mechanism and guide treatment. Figure: Axial-DWI (A) shows an acute right-medullary infarct (arrow). (B) Right-VA stenosis (arrow) on CTA. 7T axial-SWAN (C) reveals focal-susceptibility (arrowhead) and intra-vessel hemosiderin (arrow) suggestive of IPH. Axial-T1 pre-contrast (D), post-contrast (E) and sagittal MPR (F) images show eccentric thickening/enhancement of right-VA (arrowheads), compared to normal-appearing left-VA (arrows D-E).

2019 ◽  
Vol 1 ◽  
pp. 193-214
Author(s):  
Ramez N. Abdalla ◽  
Donald R. Cantrell ◽  
Alireza Vali ◽  
Michael C. Hurley ◽  
Ali Shaibani ◽  
...  

2019 ◽  
Author(s):  
Xianjin Zhu ◽  
Hancheng Qiu ◽  
Ferdinand K Hui ◽  
Yiqun Zhang ◽  
Yun-e Liu ◽  
...  

Abstract Background: Direct evidence of intimal flaps, double lumen and intramural haematomas (IMH) is difficult to detect on conventional angiography in most intracranial vertebrobasilar dissecting aneurysms (VBDAs). Our purpose was to assess the value of three-dimensional high-resolution magnetic resonance vessel wall imaging (3D HRMR VWI) for identifying VBDAs. Methods: Between August 2013 and January 2016, consecutive patients with suspicious VBDAs were prospectively enrolled to undergo catheter angiography and VWI (pre- and post-contrast). The lesion was diagnosed as definite VBDA when presenting direct signs of dissection; as possible when only presenting indirect signs; and as segmental ectasia when there was local dilation and wall thickness similar to adjacent normal artery’s without mural thrombosis. Results: Twenty-one patients with 27 lesions suspicious for VBDAs were finally included. Based on findings of VWI and catheter angiography, definite VBDA was diagnosed in 25 and 7 lesions (92.6%, vs 25.9%, p = 0.000), respectively; possible VBDA in 0 and 20 (0 vs 74.1%), respectively; and segmental ectasia in 2 and 0 (7.4% vs 0%), respectively. On VWI and catheter angiography, intimal flap was detected in 21 and 7 lesions (77.8% vs 25.9%, p=0.001), respectively; double lumen sign in 18 and 7 (66.7% vs 25.9%, p=0.003), respectively; and IMH sign in 14 and 0 (51.9% vs 0), respectively. Conclusions: 3D HRMR VWI was superior to catheter angiography in achieving definite diagnosis of intracranial VBDAs with higher rate of detection of direct dissection signs; and allowed a promising way to differentiate between VBDA and segmental ectasia.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Jorge A Roa ◽  
Mario Zanaty ◽  
Avery Pazour ◽  
Carlos Osorno-Cruz ◽  
Daizo Ishii ◽  
...  

Background: High-resolution vessel wall imaging (HR-VWI) has emerged as a valuable tool in assessing unruptured intracranial aneurysms (UIAs). There is no standardized method to quantify contrast enhancement of the aneurysmal wall. Contrast enhancement is reflected as signal intensity (SI) at the time of objective quantification. This study compares all the existing methods to objectively quantify contrast enhancement of UIAs. Methods: 3T HR-VWI was used to prospectively image patients with UIAs. Three different methods were analyzed in T1 pre- and post-contrast sequences: (1) circumferential aneurysm wall enhancement (CAWE) = mean post-contrast SI; (2) aneurysm-to-pituitary enhancement ratio (CR stalk ) = ratio of CAWE over pituitary stalk enhancement; and (3) enhancement ratio (ER) = max post-contrast SI - max pre-contrast SI/max pre-contrast SI x 100%. Known risks factors of aneurysm instability such as size ≥7mm and location in the anterior communicating (ACOM) and basilar arteries (BA) were used for analysis. Results: Forty-seven patients with 53 UIAs were included in the study. Mean age was 63.5 years, and 35 (74.5%) were women. UIAs ≥ 7mm showed significantly higher SI measurements for CAWE (273.1 vs 206.9, P =.05), CR stalk (0.49 vs 0.38, P =.006), and ER (85.7% vs 52.5%, P =.002) compared to smaller UIAs. SI was higher in UIAs located in the ACOM and BA (279.6 vs 235.7; 0.45 vs 0.44; 75.1% vs 61.3%) for CAWE, CR stalk and ER, respectively. ROC curves demonstrated sensitivity/specificity values of 0.74/0.64 for CAWE ≥ 205, 0.74/0.60 for CR stalk ≥ 0.398, and 0.71/0.73 for ER ≥ 62.1%. We found a moderately strong correlation between CAWE and CR stalk (Spearman = 0.69), CAWE and ER (Spearman = 0.52) and CR stalk and ER (Spearman = 0.47), with P <.001 in all cases. Conclusion: Three different methods: CAWE, CR stalk and ER may be used reliably to quantify SI in the wall of UIAs. Figure: ROC curves for (A) CAWE, (B) CR stalk and (C) ER.


2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
PN Sylaja ◽  
Soumya Sundaram ◽  
PNaveen Kumar ◽  
DevPrakash Sharma ◽  
Chandrasekharan Kesavadas ◽  
...  

2019 ◽  
Vol 67 (2) ◽  
pp. 588
Author(s):  
PN Sylaja ◽  
K Arun ◽  
Chinmay Nagesh ◽  
C Kesavadas ◽  
SapnaE Sreedharan

2018 ◽  
Vol 66 (4) ◽  
pp. 1124 ◽  
Author(s):  
PN Sylaja ◽  
Rajendran Adhithyan ◽  
Praveen Kesav ◽  
Bejoy Thomas ◽  
Chandrasekharan Kesavadas

2019 ◽  
Vol 11 (11) ◽  
pp. 1105-1112 ◽  
Author(s):  
Edgar A Samaniego ◽  
Jorge A Roa ◽  
David Hasan

High-resolution vessel wall imaging (HR-VWI) is becoming a useful tool in the characterization and identification of unstable unruptured brain aneurysms. However, it has not been validated for clinical use. The current evidence on HR-VWI techniques for characterization of brain aneurysms is described in this review. Specific imaging approaches such as aneurysm wall contrast enhancement, MRI-quantitative susceptibility mapping, and 7T MRI are described in detail.


2020 ◽  
Vol 9 (4) ◽  
pp. 979
Author(s):  
Daizo Ishii ◽  
Daichi Nakagawa ◽  
Mario Zanaty ◽  
Jorge A. Roa ◽  
Sami Al Kasab ◽  
...  

Background: MR-quantitative susceptibility mapping (QSM) can identify microbleeds (MBs) in intracranial aneurysm (IA) wall associated with sentinel headache (SH) preceding subarachnoid hemorrhage. However, its use is limited, due to associated skull base bonny and air artifact. MR-vessel wall imaging (VWI) is not limited by such artifact and therefore could be an alternative to QSM. The purpose of this study was to investigate the correlation between QSM and VWI in detecting MBs and to help develop a diagnostic strategy for SH. Methods: We performed a prospective study of subjects with one or more unruptured IAs in our hospital. All subjects underwent evaluation using 3T-MRI for MR angiography (MRA), QSM, and pre- and post-contrast VWI of the IAs. Presence/absence of MBs detected by QSM was correlated with aneurysm wall enhancement (AWE) on VWI. Results: A total of 40 subjects harboring 51 unruptured IAs were enrolled in the study. MBs evident on the QSM sequence was detected in 12 (23.5%) IAs of 11 subjects. All these subjects had a history of severe headache suggestive of SH. AWE was detected in 22 (43.1%) IAs. Using positive QSM as a surrogate for MBs, the sensitivity, specificity, positive predictive value, and negative predictive value of AWE on VWI for detecting MBs were 91.7%, 71.8%, 50%, and 96.6%, respectively. Conclusions: Positive QSM findings strongly suggested the presence of MBs with SH, whereas, the lack of AWE on VWI can rule it out with a probability of 96.6%. If proven in a larger cohort, combining QSM and VWI could be an adjunctive tool to help diagnose SH, especially in cases with negative or non-diagnostic CT and lumbar puncture.


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