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Arunachalam VS, Sharma S, Valakkada J, Ayyappan A, Radhakrishnan J, Kannath SK. Endovascular and percutaneous embolization of a giant post traumatic arteriovenous fistula of inferior epigastric vessels. CVIR Endovasc 2024; 7:43. [PMID: 38709345 DOI: 10.1186/s42155-024-00455-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 04/23/2024] [Indexed: 05/07/2024] Open
Abstract
BACKGROUND Arteriovenous fistulas involving the anterior abdominal wall can result from trauma. Such fistulas may remain asymptomatic and undetected for a prolonged duration of time. They tend to recruit multiple arterial feeders with remodelling in the feeding arteries, making them challenging to treat. CASE PRESENTATION We discuss a rare case of a 60-year-old male who presented with complaints of a progressive painless swelling in right lower abdomen. There was a history of blunt injury to abdomen at the same site during alleged road traffic accident 3 years ago. On CT angiography, an arteriovenous fistula was localised to the anterior abdominal wall arising predominantly from the right inferior epigastric artery with a giant venous sac and terminating as a tortuous single venous channel into the right external iliac vein. Few other small feeders were also seen arising from branches of right superior epigastric artery along Winslow's pathway. The main challenge in endovascular management of this patient was embolization of a high flow shunt with a large venous sac and multiple arterial feeders. The dominant arterial feeder was embolized using vascular plug. The superficial location of the lesion offered an additional percutaneous window besides endovascular approach. The venous sac was percutaneously accessed and embolized using n-butyl cyanoacrylate after balloon occlusion of outflow vein. On follow up ultrasonographic evaluation at 3 months, near complete thrombosis of the venous sac was achieved. CONCLUSIONS Traumatic arteriovenous fistulas involving the inferior epigastric vessels are rare clinical entities. CT angiogram and digital subtraction angiography help in the optimal diagnosis and treatment planning. The use of mechanical embolization devices to cause flow arrest offers an opportunity to use liquid embolic agents which offer better percolation within the lesion. Interventional radiology offers an ideal management of these complex high flow fistulas with a good technical success and acceptable safety profile.
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Affiliation(s)
- Venkata Subbaih Arunachalam
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Smily Sharma
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
| | - Jineesh Valakkada
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Anoop Ayyappan
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Jayakrishnan Radhakrishnan
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Santhosh Kumar Kannath
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
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Mishra D, Kannath SK, Er J, Thomas B, Kesavadas C. Evaluating the diagnostic performance of non-contrast magnetic resonance angiography sequences in the pre-procedural comprehensive analysis of direct carotid cavernous fistula. Neuroradiology 2024:10.1007/s00234-024-03342-x. [PMID: 38581636 DOI: 10.1007/s00234-024-03342-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 03/19/2024] [Indexed: 04/08/2024]
Abstract
PURPOSE Endovascular treatment of direct carotid cavernous fistula (DCCF) requires invasive diagnostic cerebral angiography for diagnosis and planning; however, a less invasive modality like magnetic resonance angiography (MRA) can be useful, especially in high-risk cases. This single-centre study evaluated a newer MR angiography (MRA) sequence, silent MRA and the traditional time of flight (TOF) MRA for pre-procedural treatment planning of DCCF. METHODS All consecutive DCCF patients who underwent TOF, silent MRA and diagnostic cerebral angiography were included in the study. Angiographic features like rent size, location, draining veins and collateral communicating arteries were analysed and compared between the two MRA sequences, with digital subtraction angiography (DSA) as the gold standard. RESULTS Fifteen patients were included in the study. TOF MRA exhibited better sensitivity (76.9% vs 69.2%) in identifying the rent location, correctly pinpointing the location in 93.3% compared to 73.3% with silent MRA. Both MRA sequences showed good agreement with DSA for primary sac and rent size. TOF MRA correctly identified 86.2% of 210 total venous structures compared to 96% by silent MRA. Silent MRA demonstrated higher sensitivity (90% vs 76%) and accuracy (87.69 vs 94.36) in visualisation of involved veins compared to TOF MRA. CONCLUSION Arterial characteristics of DCCF like rent location and rent size were better assessed by TOF MRA. Although both MRA identified venous features, silent MRA correlated better with DSA irrespective of the size and proximity to the site of the fistula. Combining both sequences can evaluate various angioarchitectural features of DCCF useful for therapeutic planning.
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Affiliation(s)
- Dewansh Mishra
- Imaging Sciences and Interventional Radiology, Sree Chitra Thirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India
| | - Santhosh Kumar Kannath
- Imaging Sciences and Interventional Radiology, Sree Chitra Thirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India.
| | - Jayadevan Er
- Imaging Sciences and Interventional Radiology, Sree Chitra Thirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India
| | - Bejoy Thomas
- Imaging Sciences and Interventional Radiology, Sree Chitra Thirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India
| | - C Kesavadas
- Imaging Sciences and Interventional Radiology, Sree Chitra Thirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, 695011, India
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Kamepalli HK, Kannath SK, Sylaja PN, Rajan JE, Chandrasekharan K. Thrombus Attenuation Gradient Can Predict Successful First-Pass Recanalization Following Stentriever Thrombectomy. World Neurosurg 2024; 181:e780-e788. [PMID: 37925151 DOI: 10.1016/j.wneu.2023.10.126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/06/2023]
Abstract
OBJECTIVE Computed tomography angiography (CTA) derived thrombus enhancement characteristics can predict first-pass recanalization. We studied whether dynamic contrast kinetics within the clot in multiphase CTA can predict first-pass recanalization following stentriever thrombectomy. METHODS Patients with acute large vessel occlusive stroke evaluated with multiphasic CTA who underwent stentriever thrombectomy were selected. Thrombus perviousness on various phases including arterial, venous, and delayed phases was calculated. Thrombus attenuation gradient (TAG), defined as average attenuation difference between adjacent phases, was also evaluated and correlated with successful first-pass outcome (modified Treatment in Cerebral Ischemia score ≥2b). RESULTS Of 69 patients, 32 (47%) had successful first-pass recanalization (group 1), and 37 (53%) required >1 attempt (group 2). TAG showed significant differences in arterial-plain and venous-arterial phases. The early increase in TAG was seen in group 1 in the arterial-plain phase, as opposed to group 2 (12.6 vs. 9, P = 0.01), which plateaued in the venous-arterial phase for group 1 and showed a further increase in group 2 (2.1 vs. 5.1, P = 0.02). A cutoff value of 9.2 HU for arterial-plain phase (P = 0.001) and 4.2 HU (P = 0.001) for venous-arterial phase was predictive of first-pass effect. Combining 2 metrics had an odds ratio of 2.8 for first-pass recanalization (P = 0.035). Accuracy evaluated in a validation cohort yielded 74%. Other features including histology were not significant. CONCLUSIONS TAG evaluated from multiphase CTA can predict first-pass effect in stentriever thrombectomy.
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Affiliation(s)
- Hari Kishore Kamepalli
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
| | - Santhosh Kumar Kannath
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India.
| | - P N Sylaja
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
| | - Jayadevan Enakshy Rajan
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
| | - Kesavadas Chandrasekharan
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
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Raj R, Kannath SK, Mathew J, Sylaja PN. AutoML accurately predicts endovascular mechanical thrombectomy in acute large vessel ischemic stroke. Front Neurol 2023; 14:1259958. [PMID: 37840939 PMCID: PMC10569475 DOI: 10.3389/fneur.2023.1259958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 09/11/2023] [Indexed: 10/17/2023] Open
Abstract
Background and objective Automated machine learning or autoML has been widely deployed in various industries. However, their adoption in healthcare, especially in clinical settings is constrained due to a lack of clear understanding and explainability. The aim of this study is to utilize autoML for the prediction of functional outcomes in patients who underwent mechanical thrombectomy and compare it with traditional ML models with a focus on the explainability of the trained models. Methods A total of 156 patients of acute ischemic stroke with Large Vessel Occlusion (LVO) who underwent mechanical thrombectomy within 24 h of stroke onset were included in the study. A total of 34 treatment variables including clinical, demographic, imaging, and procedure-related data were extracted. Various conventional machine learning models such as decision tree classifier, logistic regression, random forest, kNN, and SVM as well as various autoML models such as AutoGluon, MLJAR, Auto-Sklearn, TPOT, and H2O were used to predict the modified Rankin score (mRS) at the time of patient discharge and 3 months follow-up. The sensitivity, specificity, accuracy, and AUC for traditional ML and autoML models were compared. Results The autoML models outperformed the traditional ML models. For the prediction of mRS at discharge, the highest testing accuracy obtained by traditional ML models for the decision tree classifier was 74.11%, whereas for autoML which was obtained through AutoGluon, it showed an accuracy of 88.23%. Similarly, for mRS at 3 months, the highest testing accuracy of traditional ML was that of the SVM classifier at 76.5%, whereas that of autoML was 85.18% obtained through MLJAR. The 24-h ASPECTS score was the most important predictor for mRS at discharge whereas for prediction of mRS at 3 months, the most important factor was mRS at discharge. Conclusion Automated machine learning models based on multiple treatment variables can predict the functional outcome in patients more accurately than traditional ML models. The ease of clinical coding and deployment can assist clinicians in the critical decision-making process. We have developed a demo application which can be accessed at https://mrs-score-calculator.onrender.com/.
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Affiliation(s)
- Rishi Raj
- Department of Computer Science and Engineering, Indian Institute of Technology Patna, Patna, India
| | - Santhosh Kumar Kannath
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Jimson Mathew
- Department of Computer Science and Engineering, Indian Institute of Technology Patna, Patna, India
| | - P. N. Sylaja
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
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Kumar AA, Kannath SK, Thomas B, Pn S, P S, Surendran M. Reverse Flow Thromboembolism From Distal Subclavian Artery Aneurysm Due to Arterial Thoracic Outlet Syndrome and Posterior Circulation Stroke- Role of Dynamic Doppler Imaging. Neurologist 2023:00127893-990000000-00106. [PMID: 37839091 DOI: 10.1097/nrl.0000000000000536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
INTRODUCTION Arterial thoracic outlet syndrome (aTOS) is the least common among the 3 subtypes of thoracic outlet syndrome and can be the cause of posterior circulation infarction due to thrombus from a secondary thrombosed subclavian-axillary artery aneurysm. CASE REPORT Here, we report a case of a 51-year-old man who presented to our institute with sudden onset vertigo, dizziness, vomiting, gait imbalance, and visual field defects immediately after strenuous exercise. Computed tomography angiography revealed bilateral cervical ribs with aneurysmal dilatation of the left distal subclavian and proximal axillary arteries. The computed tomography also revealed subacute infarcts in the bilateral cerebellar hemispheres, as well as in the bilateral occipital lobes. Color Doppler evaluation of the subclavian artery after hyperabduction of the ipsilateral arm revealed a continuous reversal of flow in the subclavian artery, which reached the vertebral ostia. The left cervical rib was resected, aneurysm was repaired, and the patient remained asymptomatic on follow-up. CONCLUSION Posterior circulation stroke caused by the ipsilateral thrombosed subclavian artery aneurysm in an adult patient with aTOS due to a complete cervical rib is rare. A high index of suspicion should be present for thoracic outlet syndrome in patients with stroke and upper-limb arterial claudication symptoms. Dynamic Doppler evaluation in such patients can be used to demonstrate the underlying pathomechanism, and definitive surgical treatment can prevent further ischemic episodes. Posterior circulation stroke caused by partially thrombosed distal subclavian and axillary artery aneurysms due to aTOS is rare.
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Affiliation(s)
| | | | - Bejoy Thomas
- Departments of Imaging Sciences and Interventional Radiology
| | | | - Shivanesan P
- Department of Cardiovascular and Thoracic Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
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Kandasamy S, Kannath SK, Enakshy Rajana J, Kesavadas C, Thomas B. Non-invasive angiographic analysis of dural carotid cavernous fistula using time-of-flight MR angiography and silent MR angiography: a comparative study. Acta Radiol 2023; 64:1290-1297. [PMID: 35532027 DOI: 10.1177/02841851221097462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND A non-invasive, reliable imaging modality that characterizes cavernous sinus dural arteriovenous fistula (CSDAVF) is beneficial for diagnosis and to assess resolution on follow-up. PURPOSE To assess the utility of 3D time-of-flight (TOF) and silent magnetic resonance angiography (MRA) for evaluation of CSDAVF from an endovascular perspective. MATERIAL AND METHODS This prospective study included 37 patients with CSDAVF, who were subjected to digital subtraction angiography (DSA) and 3-T MR imaging with 3D TOF and silent MRA. The main arterial feeders, fistula site, and venous drainage pattern were evaluated, and the results were compared with DSA findings. The diagnostic confidence scores were also recorded using a 4-point Likert scale. RESULTS Silent MRA correlated better for shunt site localization and angiographic classification (86% vs. 75% and 83% vs. 75%, respectively) compared to TOF MRA. The proportion of arterial feeders detected was marginally significant for silent MRA over TOF MRA sequences (92.8% vs. 89.5%; P=0.048), though for veins both were comparable. Sensitivity of silent MRA was higher for identification of cortical venous reflux (CVR) (90.9% vs. 81.8%) and deep venous drainage (82.4% vs. 64.7%), while specificity was >90% for both modalities. The overall diagnostic confidence score fared better for silent MRA for venous assessment (P < 0.001) as well as fistula point identification (P < 0.001), while no significant difference was evident with TOF MRA for arterial feeders (P=0.06). CONCLUSION Various angiographic components of CSDAVF could be identified and delineated by 3D TOF and silent MRA, though silent MRA was superior for overall diagnostic assessment.
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Affiliation(s)
- Sathish Kandasamy
- Department of Imaging Sciences and Interventional Radiology, 29354Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
- Department of Interventional Radiology, 29904G Kuppusamy Naidu, Memorial Hospital, Coimbatore, Tamil nadu, India
| | - Santhosh Kumar Kannath
- Department of Imaging Sciences and Interventional Radiology, 29354Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Jayadevan Enakshy Rajana
- Department of Imaging Sciences and Interventional Radiology, 29354Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Chandrasekaran Kesavadas
- Department of Imaging Sciences and Interventional Radiology, 29354Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Bejoy Thomas
- Department of Imaging Sciences and Interventional Radiology, 29354Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
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Senthilvelan S, Kannath SK, Arun KM, Menon R, Kesavadas C. Non-invasive assessment of cerebral hemoglobin parameters in intracranial dural arteriovenous fistula using functional near-infrared spectroscopy-A feasibility study. Front Neurosci 2022; 16:932995. [PMID: 36452332 PMCID: PMC9703974 DOI: 10.3389/fnins.2022.932995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 09/27/2022] [Indexed: 11/05/2023] Open
Abstract
PURPOSE The purpose of this study was to assess the feasibility of non-invasive assessment of cerebral hemodynamics using functional near-infrared spectroscopy (fNIRS) in patients with intracranial dural arteriovenous fistula (DAVF) and to correlate the hemodynamic changes with definitive endovascular treatment. METHODOLOGY Twenty-seven DAVF patients and 23 healthy controls underwent 20-mins task-based functional near-infrared spectroscopy and neuropsychology evaluation. The mean change in the hemoglobin concentrations obtained from the prefrontal cortex was assessed for oxyhemoglobin, deoxyhemoglobin, and oxygen saturation (HbO, HbR, and SO2, respectively). The fNIRS data were analyzed and correlated with improvement in neuropsychology scores at 1-month follow-up. RESULTS There was a significant reduction in HbO in the patient group, while it increased in controls (-2.57E-05 vs. 1.09E-04 mM, p < 0.001). The reduced HbO significantly improved after embolization (-2.1E-04 vs. 9.9E-04, p = 0.05, q = 0.05). In patients with aggressive DAVF (Cognard 2B and above), the change was highly significant (p < 0.001; q = 0.001). A moderate correlation was observed between MMSE scores and HbO changes (ρ = 0.4). CONCLUSION fNIRS is a useful non-invasive modality for the assessment of DAVF, and could potentially assist in bedside monitoring of treatment response.
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Affiliation(s)
- Santhakumar Senthilvelan
- Neuroradiology Division, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | - Santhosh Kumar Kannath
- Neuroradiology Division, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | - Karumattu Manattu Arun
- Neuroradiology Division, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | - Ramshekhar Menon
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | - Chandrasekharan Kesavadas
- Neuroradiology Division, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
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Kumar Kannath S, Anzar A, Sivan Sulaja J, Enakshy Rajan J, PN S. Semi-automated mapping of occluded arterial segments in acute large vessel stroke from computed tomography angiography. J Stroke Cerebrovasc Dis 2022; 31:106763. [DOI: 10.1016/j.jstrokecerebrovasdis.2022.106763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/04/2022] [Indexed: 11/25/2022] Open
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Raj R, Mathew J, Kannath SK, Rajan J. Crossover based technique for data augmentation. Comput Methods Programs Biomed 2022; 218:106716. [PMID: 35290901 DOI: 10.1016/j.cmpb.2022.106716] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 02/19/2022] [Accepted: 02/26/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND OBJECTIVE Medical image classification problems are frequently constrained by the availability of datasets. "Data augmentation" has come as a data enhancement and data enrichment solution to the challenge of limited data. Traditionally data augmentation techniques are based on linear and label preserving transformations; however, recent works have demonstrated that even non-linear, non-label preserving techniques can be unexpectedly effective. This paper proposes a non-linear data augmentation technique for the medical domain and explores its results. METHODS This paper introduces "Crossover technique", a new data augmentation technique for Convolutional Neural Networks in Medical Image Classification problems. Our technique synthesizes a pair of samples by applying two-point crossover on the already available training dataset. By this technique, we create N new samples from N training samples. The proposed crossover based data augmentation technique, although non-label preserving, has performed significantly better in terms of increased accuracy and reduced loss for all the tested datasets over varied architectures. RESULTS The proposed method was tested on three publicly available medical datasets with various network architectures. For the mini-MIAS database of mammograms, our method improved the accuracy by 1.47%, achieving 80.15% using VGG-16 architecture. Our method works fine for both gray-scale as well as RGB images, as on the PH2 database for Skin Cancer, it improved the accuracy by 3.57%, achieving 85.71% using VGG-19 architecture. In addition, our technique improved accuracy on the brain tumor dataset by 0.40%, achieving 97.97% using VGG-16 architecture. CONCLUSION The proposed novel crossover technique for training the Convolutional Neural Network (CNN) is painless to implement by applying two-point crossover on two images to form new images. The method would go a long way in tackling the challenges of limited datasets and problems of class imbalances in medical image analysis. Our code is available at https://github.com/rishiraj-cs/Crossover-augmentation.
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Affiliation(s)
- Rishi Raj
- Department of Computer Science and Engineering, Indian Institute of Technology Patna, India.
| | - Jimson Mathew
- Department of Computer Science and Engineering, Indian Institute of Technology Patna, India
| | - Santhosh Kumar Kannath
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Kerala, India
| | - Jeny Rajan
- Department of Computer Science and Engineering, National Institute of Technology Karnataka, India
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Sekar S, Kannath SK, Ramachandran S, Menon RN, Thomas B. Alterations in Resting-State Functional MRI Connectivity Related to Cognitive Changes in Intracranial Dural Arteriovenous Fistulas Before and After Embolization Treatment. J Magn Reson Imaging 2021; 55:1183-1199. [PMID: 34592019 DOI: 10.1002/jmri.27936] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Cognitive decline is a non-hemorrhagic, major complication of intracranial dural arteriovenous fistula (DAVF), thought to be primarily related to venous hypertension. However, imaging features to predict cognitive decline are scanty in the literature. PURPOSE To evaluate functional connectivity (FC) changes of resting-state networks (RSNs) in DAVF before and after treatment and its relation to cognitive impairment. STUDY TYPE Prospective. SUBJECTS DAVF subjects were screened for inclusion. Pre-embolization (N = 33, mean age 45.9 years, 29 males), 1 month post-embolization (N = 20, mean age 42.7 years, 19 males), and healthy controls (HC, N = 33, mean age 45.09 years, 27 males). FIELD STRENGTH/SEQUENCE 3.0 T, resting-state functional magnetic resonance imaging (MRI), three-dimensional (3D) T1, T2 fast spin echo (FSE), diffusion weighted imaging (DWI), susceptibility weighted imaging (SWI), fluid-attenuated inversion recovery, and time of flight. ASSESSMENT Data quality assessment was performed. FC analysis was done using group independent component analysis (ICA) and seed to voxel analysis. Neuropsychology (NP) scores of patients were compared with HC and correlated with FC changes. STATISTICAL TESTS Voxel-wise parametric T-statistics for F-test was executed in FC analysis (p-FDR corrected <0.05). NP scores between DAVF group and HC group were compared using one-way analysis of variance with post hoc Bonferroni correction (P < 0.05). RESULTS Both RSNs analysis methods showed reduced FC at the precuneus-posterior cingulate cortex (PC-PCC) of default mode network (DMN), anterior cingulate cortex (ACC) of the salience network (SN), and possible compensatory increased connectivity at the frontoparietal (FPN) and dorsal attention (DAN) networks. DAVF with low NP scores showed reduced FC at DMN and SN and minimal to absent connectivity at FPN and DAN. At post-embolization 1-month follow-up, improvement in FC at PC-PCC of DMN and ACC of SN were noted. DATA CONCLUSION RS-fMRI in DAVF displayed FC changes that may be related to cognitive decline and its subsequent reversibility after treatment. FC changes at DMN, SN, FPN, and DAN were linked to cognitive decline and the corresponding NP scores. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Sabarish Sekar
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Santhosh Kumar Kannath
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Sushama Ramachandran
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Ramshekhar N Menon
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Bejoy Thomas
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
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Joseph JE, Sekar S, Kannath SK, Menon RN, Thomas B. Impaired intrinsic functional connectivity among medial temporal lobe and sub-regions related to memory deficits in intracranial dural arteriovenous fistula. Neuroradiology 2021; 63:1679-1687. [PMID: 33837804 DOI: 10.1007/s00234-021-02707-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 03/29/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE The functional changes concerning memory deficits in dural arteriovenous fistula (dAVF) brain are inadequately understood. This study aimed to understand the functional connectivity alterations of brain regions widely affirmed for explicit and implicit memory functions in dAVF patients (DP) and look into the frequency effects of the altered functional networks. METHODS Resting-state functional magnetic resonance imaging (rsfMRI) analysis was done in the memory-associated regions of 30 DP and 30 healthy controls (HC). Frequency decomposition was used to determine potential frequency-dependent functional connectivity changes. They underwent neuropsychological tests and were correlated with changes in memory networks compared with HC. RESULTS The results showed weaker functional connectivity among the medial temporal lobe and sub-regions in DP suggestive of dysfunction of explicit and implicit memory functions, which corroborated with the positive correlation between memory scores and hippocampal-parahippocampal connectivity of DP, along with a significant group difference of lower memory and cognitive performance in DP assessed by neuropsychological tests. A frequency-dependent study of the altered rsFC revealed lower functional connectivity strength and impaired neural coupling manifested at some sub-band frequencies indicative of disturbed cortical rhythm in DP. CONCLUSION This pilot study gives insights into significant intrinsic functional connectivity changes in the memory regions of the dAVF brain. The results may have clinical implications in the choice of interventional management of dAVF and can impact clinical decision making for realizable prevention of progressive memory impairment and irreversible brain damage in such patients.
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Affiliation(s)
- Josline Elsa Joseph
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, 695011, India
| | - Sabarish Sekar
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, 695011, India
| | - Santhosh Kumar Kannath
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, 695011, India
| | - Ramshekhar N Menon
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Bejoy Thomas
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, 695011, India.
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Sharma DP, Kannath SK, Singh G, Rajan JE. Shunt Site Localization of Direct Carotid-Cavernous Fistula Using 3D Rotational Angiography-Utility of Broken-Rim Sign. World Neurosurg 2020; 144:e376-e379. [PMID: 32890847 DOI: 10.1016/j.wneu.2020.08.167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/20/2020] [Accepted: 08/22/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Direct carotid-cavernous fistulas (DCCF) develop due to breach in the integrity of the wall of the internal carotid artery, and its localization can sometimes be difficult due to rapid high flow shunts. We hypothesized that 3D rotational angiography could locate the fistula site accurately, where an interrupted rim of the carotid wall would be silhouetted against opacified vascular structures. This finding was described as a broken-rim sign, and in this study, we assessed the utility of this sign in the localization of the shunt point of DCCF. METHODS Retrospective analysis of 15 cases of DCCF was performed, and the rent was characterized based on the broken-rim sign. Two observers independently evaluated the results and compared them against the intraoperative observations. RESULTS The broken-rim sign was identified and correlated with the actual fistula site in 86.6% and 100% of patients by observers 1 and 2, respectively. The inter-rater agreement was 0.87 (P < 0.001). Misinterpretation was made in 2 patients by 1 observer, due to poor contrast opacification of the vascular structures secondary to very rapid shunting and mild movement artifacts. CONCLUSIONS Our study highlights the role of 3D rotational angiogram and analysis of the carotid wall in the localization of the shunt site in DCCF. The broken-rim sign accurately points to the location of the fistula.
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Affiliation(s)
- Dev Prakash Sharma
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute For Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Santhosh Kumar Kannath
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute For Medical Sciences and Technology, Trivandrum, Kerala, India.
| | - Gurpreet Singh
- Achutha Menon Center for Health Science Studies, Sree Chitra Tirunal Institute For Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Jayadevan Enakshy Rajan
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute For Medical Sciences and Technology, Trivandrum, Kerala, India
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Kannath SK, Mandapalu S, Thomas B, Enakshy Rajan J, Kesavadas C. Comparative Analysis of Volumetric High-Resolution Heavily T2-Weighted MRI and Time-Resolved Contrast-Enhanced MRA in the Evaluation of Spinal Vascular Malformations. AJNR Am J Neuroradiol 2019; 40:1601-1606. [PMID: 31439626 DOI: 10.3174/ajnr.a6164] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/01/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Volumetric high-resolution heavily T2-weighted imaging or time-resolved contrast-enhanced MRA is used in the detection and characterization of spinal vascular malformations, though inherent trade-offs can affect their overall sensitivity and accuracy. We compared the efficacy of volumetric high-resolution heavily T2-weighted and time-resolved contrast-enhanced images in spinal vascular malformation diagnosis and feeder characterization and assessed whether a combined evaluation improved the overall accuracy of diagnosis. MATERIALS AND METHODS Twenty-eight patients with spinal vascular malformations (spinal dural arteriovenous fistula, spinal cord arteriovenous malformation, and perimedullary arteriovenous fistula) were prospectively enrolled. MR images were separately analyzed by 2 neuroradiologists blinded to the final diagnosis. RESULTS Both sequences demonstrated 100% sensitivity and 93.5% accuracy for the detection of spinal vascular malformations. Volumetric high-resolution heavily T2-weighted imaging was superior to time-resolved contrast-enhanced MR imaging for identification of spinal cord arteriovenous malformations (100% versus 90% sensitivity and 96.7% versus 93.5% accuracy), however, for the diagnosis of perimedullary arteriovenous fistula, time resolved contrast enhanced MRI was found to perform better than the volumetric T2 sequence (80% versus 60% sensitivity and 96.7% versus 93.5% accuracy). Both sequences showed equal sensitivity (100%) and accuracy (87%) for spinal dural arteriovenous fistulas. Combined evaluation improved the overall accuracy across all types of spinal vascular malformation. Volumetric high-resolution heavily T2-weighted imaging was superior or equal to time-resolved contrast-enhanced MR imaging for feeder identification of spinal dural arteriovenous fistulas for both observers (90.9% and 72.7% versus 72.7%), which improved to 90.9% when the sequences were combined. Time-resolved contrast-enhanced MR imaging performed better for major and total feeder identification of spinal cord arteriovenous malformation (80% versus 60%) and perimedullary arteriovenous fistula (80% versus 60%-80%). CONCLUSIONS Combined volumetric high-resolution heavily T2-weighted imaging and time-resolved contrast-enhanced MR imaging can improve the sensitivity and accuracy of spinal vascular malformation diagnosis, classification, and feeder characterization.
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Affiliation(s)
- S K Kannath
- From the Department of Imaging Sciences and Interventional Radiology (S.K.K., B.T., J.E.R., C.K.), Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - S Mandapalu
- Department of Radiology (S.M.), NRI Medical College, Chinakakani, Guntur, Andra Pradesh, India
| | - B Thomas
- From the Department of Imaging Sciences and Interventional Radiology (S.K.K., B.T., J.E.R., C.K.), Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - J Enakshy Rajan
- From the Department of Imaging Sciences and Interventional Radiology (S.K.K., B.T., J.E.R., C.K.), Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
| | - C Kesavadas
- From the Department of Imaging Sciences and Interventional Radiology (S.K.K., B.T., J.E.R., C.K.), Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
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Pan S, Kannath SK, Rajan JE. Low-Profile Neuroform Atlas Stent-Assisted Coiling of Intracranial Aneurysms: Single-Center Initial Experience. J Clin Interv Radiol ISVIR 2019. [DOI: 10.1055/s-0039-1685243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Abstract
Background Neuroform Atlas stent is a relatively new device used for stent-assisted coiling (SAC) of wide-necked intracranial aneurysms.
Purpose To elaborate the initial experience in a single center to assess the efficacy and initial results of Neuroform Atlas for SAC of intracranial aneurysms.
Methods Between February 2017 and September 2018, eight patients (five females, three males; mean age 56 years) underwent SAC with Neuroform Atlas.
Results Five unruptured and three ruptured wide-necked aneurysms were treated with Neuroform Atlas SAC. Immediate complete occlusion modified Roy-Raymond class 1 (MRRC 1) or mild neck residue class 2 (MRRC 2) was achieved in three patients and five other patients had minimal residual interstitial filling of the aneurysm (MRRC 3b). One patient with ruptured intracranial aneurysm succumbed to the illness in the first postoperative day due to massive rebleed. Other seven patients remained clinically asymptomatic in the follow-up period. Patent stent was noted at three to seven months follow-up magnetic resonance angiography (MRA) in five patients. Complete occlusion of the aneurysm was noted in three patients, and minimal residual aneurysm was seen in two patients.
Conclusion Neuroform Atlas stent is safe and effective in achieving good angiographic outcome in complex intracranial aneurysms.
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Affiliation(s)
- Somnath Pan
- Department of Imaging Sciences and Interventional Radiology, Neurointervention Center, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Santhosh Kumar Kannath
- Department of Imaging Sciences and Interventional Radiology, Neurointervention Center, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Jayadevan Enakshy Rajan
- Department of Imaging Sciences and Interventional Radiology, Neurointervention Center, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
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Kannath SK, Rajendran A, Thomas B, Rajan JE. Volumetric T2-weighted MRI improves the diagnostic accuracy of spinal vascular malformations: comparative analysis with a conventional MR study. J Neurointerv Surg 2019; 11:1019-1023. [DOI: 10.1136/neurintsurg-2018-014522] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 02/04/2019] [Accepted: 02/06/2019] [Indexed: 11/03/2022]
Abstract
BackgroundTo date, very little study of the importance of a volumetric T2-weighted MR sequence in the evaluation of spinal vascular malformations (SVMs) has been carried out.ObjectiveTo determine the utility and accuracy of a volumetric T2 MR sequence compared with conventional T2 in the diagnosis of SVMs.MethodsRetrospective analysis of all patients who underwent spinal DSA for suspected SVMs was conducted. Conventional T2 and volumetric T2 MR images were analysed for the presence of flow voids and parenchymal changes, and SVMs were characterized. The sensitivity, specificity, and overall diagnostic accuracy of these MRI diagnoses were calculated.ResultsOf 89 subjects included in the final analysis, 70 patients had angiographically proved SVMs (38 patients with spinal cord arteriovenous malformations [SCAVM—intramedullary or perimedullary] and 32 cases of spinal dural arteriovenous fistula (SDAVF)) and the remaining 19 subjects were normal. The sensitivity and specificity for identification of SVMs were 98.1% and 90% for volumetric T2 sequences, compared with 82.8% and 89.4% for conventional T2 MRI, respectively. For characterization of spinal vascular lesions, volumetric MRI showed high sensitivity, specificity, and accuracy for SDAVF (100%, 90%, 97%, respectively) compared with conventional T2 MRI (71.8%, 89%, 79%, respectively). The positive likelihood ratio was high and negative likelihood ratio was zero for volumetric MRI evaluation of SDAVF, while these ratios were comparable between the two sequences for SCAVM.ConclusionVolumetric T2 MRI is highly sensitive for the detection of SVMs, especially for SDAVF. Volumetric T2 MRI could be introduced into routine clinical practice in the screening of suspected SVMs.
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Gopinath M, Malik V, Sankara Sarma P, Rajan JE, Kannath SK. Results of Endovascular-First Approach for Treatment of Scalp Arteriovenous Malformations and the Effect of Simplified Angiographic Classification in Therapeutic Decision-Making and Outcomes. World Neurosurg 2018; 121:e277-e286. [PMID: 30261380 DOI: 10.1016/j.wneu.2018.09.092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 09/11/2018] [Accepted: 09/12/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND Scalp arteriovenous malformation (SAVM) is primarily treated by surgery and reports on endovascular treatment are scarce. We report the results of an endovascular-first approach in the treatment of SAVM. We also have proposed a simple dichotomized classification using the angiographically determined morphology findings and discussed its effect on therapeutic decision-making and outcomes. METHODS A consecutive series of 25 patients with SAVM treated by initial or endovascular-only methods were included in the final analysis. The SAVM was categorized as a plexiform or fistulous type according to the angiographic morphology. The demographic data, treatment variables, and final clinical outcomes were analyzed and correlated with the proposed classification. RESULTS Of the 25 patients, 21 were treated with n-butyl cyanoacrylate (n-BCA) and 3 with liquid ethylene vinyl alcohol. One patient had been treated initially with polyvinyl alcohol particles and later with n-BCA. Overall, complete or near complete obliteration (>90%) was achieved in 72%. Surgical excision was performed in 76%, most often after n-BCA embolization. Fistulous-type SAVMs required greater n-BCA concentrations (median, 33% vs. 20%; P = 0.024) and achieved greater rates of complete or near-complete obliteration (90% vs. 63%). Two patients with fistulous-type SAVMs treated with liquid ethylene vinyl alcohol showed complete resolution, and further treatment was not necessary. Overall, regardless of the embolic material used, the fistulous type demonstrated a significantly greater rate of complete obliteration (75% vs. 33%; P = 0.041) compared with plexiform type. CONCLUSION High rates of complete and durable obliteration of SAVM are achievable with endovascular embolization. The proposed simplified classification is easy to implement and can aid in choosing the appropriate embolic agent and predicting the therapeutic outcome.
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Affiliation(s)
- Manoj Gopinath
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Virender Malik
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - P Sankara Sarma
- Achuta Menon Center for Health Science Studies, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Jayadevan Enakshy Rajan
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Santhosh Kumar Kannath
- Achuta Menon Center for Health Science Studies, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
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Vinayagamani S, Kannath SK, Rajan JE. Recurring Thalamic Symptoms Due to Intracranial Dural Arteriovenous Fistula: Report of Unusual Case and Treatment Outcome. World Neurosurg 2018; 118:9-13. [PMID: 29969738 DOI: 10.1016/j.wneu.2018.06.187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/21/2018] [Accepted: 06/22/2018] [Indexed: 11/26/2022]
Abstract
BACKGROUND Initial clinical presentation of dural arteriovenous fistula (DAVF) with predominantly thalamic symptoms is rare and has not been reported until now. CASE DESCRIPTION A young child presenting with complaints of tinnitus and mild right hemiparesis was evaluated with an initial magnetic resonance imaging, which revealed a Borden type 2 DAVF in the right transverse sinus with retrograde venous drainage and cortical venous reflux. Flow-related small aneurysms were also noted in the left basal vein of Rosenthal (BVR). Two days later, his motor power deteriorated and he developed right hemisensory loss and severe thalamic pain. Aphasia was atypical and mimicked the transcortical type. Repeat imaging revealed expanding thrombosed aneurysm of BVR with mass effect and edema on thalamocapsular region. Initial antiedema measures reversed the neurologic deficits; however, they recurred, necessitating an urgent endovascular intervention. Angiogram revealed an extensive high-flow DAVF in the right transverse-sigmoid sinus and torcula with preferential retrograde venous drainage into deep veins and left BVR. He underwent staged embolization of DAVF, resulting in significant obliteration of shunt. Neurologic deficits improved in the postoperative period, and the patient remained clinically asymptomatic at 6 months of follow-up. CONCLUSIONS DAVF presenting with recurrent predominantly thalamic symptoms is rare. Atypical transcortical aphasia rather than fluent aphasia is an unusual clinical manifestation of thalamic pathology and could result from the involvement of specific thalamic nuclei. Preferential high flow into BVR in the presence of venous anomalies could potentially induce architectural weakness of the venous wall and precipitate aneurysm formation. Embolization of the DAVF can potentially reverse this unusual neurologic condition.
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Affiliation(s)
- Selvadasan Vinayagamani
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Institute for Medical Sciences and Technology, Kerala, India
| | - Santhosh Kumar Kannath
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Institute for Medical Sciences and Technology, Kerala, India.
| | - Jayadevan Enakshy Rajan
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Institute for Medical Sciences and Technology, Kerala, India
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Kannath SK, Rajan JE, Sylaja PN, Sarma PS, Sukumaran S, Sreedharan SE, Kapilamoorthy TR. Dwell Time of Stentriever Influences Complete Revascularization and First-Pass TICI 3 Revascularization in Acute Large Vessel Occlusive Stroke. World Neurosurg 2017; 110:169-173. [PMID: 29113900 DOI: 10.1016/j.wneu.2017.10.155] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/26/2017] [Accepted: 10/27/2017] [Indexed: 11/25/2022]
Abstract
OBJECTIVE In acute ischemic stroke with large vessel occlusion, the interaction between the clot retriever and the stent is critical for achieving successful recanalization. The ideal time of stent deployment (dwell time [DT]) to improve revascularization is currently unknown. We systematically analyzed the effect of different DT on final angiographic and clinical outcomes of patients who underwent mechanical thrombectomy. METHODS The DT was progressively increased from 3 minutes to 5 minutes and then 8 minutes during the study period. The effect of DT on recanalization attempts, successful angiographic outcome (thrombolysis in cerebral ischemia [TICI] 2b or TICI 3), total revascularization time, and immediate and 3-month clinical outcomes were evaluated. The DT of 3 minutes and 5 minutes (DT3-5) was compared against DT of 8 minutes (DT8). RESULTS Forty patients were included in the analysis. Good angiographic outcome was observed in 94.1% of patients in the DT8 cohort with an average attempt of 1.2 compared with 78.3% with average attempts of 2.0 in other group. Single-pass good recanalization (TICI 2b or 3) and single-pass complete revascularization (TICI3) was significantly higher in the DT group compared with the DT3-5 group (82.4% vs. 43.5% [P = 0.013] and 42.9% vs. 8.7% [P = 0.003], respectively). A favorable trend toward a reduced overall procedural time (34.59 vs. 55.59 minutes) was observed, but was not statistically significant (P = 0.15). CONCLUSIONS Mild prolongation of DT to 8 minutes improves revascularization outcome with fewer attempts, possibly because of better clot-stent interaction.
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Affiliation(s)
- Santhosh Kumar Kannath
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India.
| | - Jayadevan Enakshy Rajan
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | - P N Sylaja
- Comprehensive Stroke Center, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | - P Sankara Sarma
- Achutha Menon Center, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | - Sajith Sukumaran
- Comprehensive Stroke Center, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | - Sapna Erat Sreedharan
- Comprehensive Stroke Center, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
| | - Tirur Raman Kapilamoorthy
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India
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Kannath SK, Rajan JE, Mukherjee A, Sarma P S. Factors Predicting Spontaneous Thrombosis of Aggressive Cranial Dural Arteriovenous Fistulas. World Neurosurg 2017; 103:821-828.e2. [DOI: 10.1016/j.wneu.2017.04.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 04/04/2017] [Accepted: 04/06/2017] [Indexed: 11/28/2022]
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Kannath SK, Rajan JE, Sarma SP. Anatomical localization of the cavernous sinus dural fistula by 3D rotational angiography with emphasis on clinical and therapeutic implications. J Neuroradiol 2017; 44:326-332. [PMID: 28602497 DOI: 10.1016/j.neurad.2017.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/24/2017] [Accepted: 05/03/2017] [Indexed: 11/18/2022]
Abstract
BACKGROUND AND PURPOSE Carotid cavernous sinus dural arteriovenous fistulas (CSDAVFs) are presumed to be located within the walls of the cavernous sinus, however the exact fistulous site has not yet been studied by angiographic or anatomical methods. The present study aimed to localize CSDAVFs with the help of 3D rotational angiography (RA) and correlated the observations with clinical and angiographic findings. MATERIALS AND METHODS The CSDAVFs were categorized as dural, extradural or osseous based on the site of convergence of feeders into the venous sac. Extradural CSDAVFs were further subcategorized into posteromedial, posterolateral and anterior subtypes, depending on proximity to a possible venous plexus. This classification was correlated with various clinical presentations and angiographic subtypes. RESULTS Thirty-seven patients were included in the final analysis. The sac was identified in all the patients and the mean sac size of the fistula was small (<4mm). Dural type was associated with exclusive cortical venous drainage. Extradural anterior CSDAVF showed tendency towards younger age predilection. Extradural posterolateral CSDAVF was more often associated with initial oculomotor nerve palsy and this observation was statistically significant. Discordancy between the location of the fistula and the side of clinical affection was observed in midline fistulas such as osseous CSDAVF and posteromedial type of extradural CSDAVF. CONCLUSIONS CSDAVF is a heterogeneous vascular disorder involving the sphenoclival bone, extradural space and dura, homologous to the epidural-dural shunts of vertebra with a common clinical presentation of orbital manifestations. Preoperative localization of the fistula could explain enigmatic observations and potentially simplify its interventional management.
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Affiliation(s)
- Santhosh Kumar Kannath
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, pin no. 695011, Trivandrum, Kerala, India.
| | - Jayadevan Enakshy Rajan
- Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, pin no. 695011, Trivandrum, Kerala, India.
| | - Sankara P Sarma
- Achutha Menon Center for Health Science Studies, Sree Chitra Tirunal Institute of Medical Sciences and Technology, pin no. 695011, Trivandrum, Kerala, India.
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Mohimen A, Kumar Kannath S, Jayadevan ER. Skull Base Osseous Arteriovenous Fistula-A Rare Clinical Entity: Case Report and Literature Review. World Neurosurg 2016; 97:760.e9-760.e12. [PMID: 27742504 DOI: 10.1016/j.wneu.2016.09.104] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 09/24/2016] [Accepted: 09/26/2016] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe a rare clinical entity of intraosseous skull base arteriovenous fistula managed with transvenous fistula embolization. CASE PRESENTATION A 57-year-old woman presented with complaints of headache and episodic tinnitus with progressive left-sided visual deterioration. Cross-sectional imaging of the head revealed multiple vascular channels in the sphenoid bone and in bilateral masticator spaces. Catheter angiography showed the presence of a large osseous arteriovenous fistula epicentered in the body of sphenoid and left pterygoid plates with arterial feeders from bilateral external carotid arteries and venous drainage into bilateral cavernous sinuses and the pterygoid venous plexus. She was managed by transvenous coil and liquid embolic agent (Squid 18) embolization of the venous sac with significant reduction of shunt. In the postprocedure period, the patient developed paradoxical worsening of symptoms due to central retinal vein occlusion. CONCLUSIONS Skull base osseous fistulae are uncommon clinical entities and fistulae centered within the sphenoid bone are very rare. The aim of this report was to highlight management issues associated with such a case and review the available literature on the subject.
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Affiliation(s)
- Aneesh Mohimen
- Imaging Sciences & Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Kerala, India.
| | - Santhosh Kumar Kannath
- Imaging Sciences & Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Kerala, India
| | - E R Jayadevan
- Imaging Sciences & Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Kerala, India
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Kannath SK, Thomas B, Sankara Sarma P, Enakshy Rajan J. Impact of non-contrast enhanced volumetric MRI-based feeder localization in the treatment of spinal dural arteriovenous fistula. J Neurointerv Surg 2016; 9:178-182. [PMID: 27557942 DOI: 10.1136/neurintsurg-2016-012497] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 07/27/2016] [Accepted: 08/05/2016] [Indexed: 11/03/2022]
Abstract
BACKGROUND The preoperative localization of the feeder of spinal dural arteriovenous fistula (SDAVF) could simplify the diagnostic spinal angiographic procedure. Localization by non-contrast-enhanced MRI-based techniques is an attractive option. However, the usefulness of such an approach for evaluation of SDAVF has not yet been reported. OBJECTIVE To study the impact of non-contrast MRI-based feeder localization, followed by targeted spinal angiography, in the evaluation of SDAVF before endovascular intervention. MATERIALS AND METHODS Prospectively collected data were analyzed and the level of the feeder was localized preoperatively. The procedural time for targeted spinal angiography was calculated and compared with that of a historical cohort, who underwent routine spinal angiographic examination before the study period. Follow-up MRI was carried out to assess the reliability of this model for detection of occasional metachronous lesions that might be missed with this approach. RESULTS Seven patients underwent targeted spinal angiography during the study. The feeder level was accurately identified in five patients and was localized to one vertebral level in six patients. The correlation between MRI and DSA was statistically significant. The number of spinal levels assessed was fewer and overall procedure time was significantly shorter compared to historical cohort (58 min vs 162 min, respectively; p<0.001). Intervention was coupled with targeted angiography in two patients. Follow-up MRI demonstrated flow voids in one patient, who had recurrent fistula at one vertebral level below the previously embolized feeder. CONCLUSIONS The non-contrast MRI-based localization technique can reliably detect the level of feeder and help in therapeutic planning of SDAVF. The localization techniques potentially shorten the angiographic procedure and may facilitate simultaneous endovascular definitive treatment. Inclusion of follow-up MRI may be useful for detection of synchronous or metachronous lesions if a targeted approach is adopted. Additionally, this helps to identify failed endovascular therapy.
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Affiliation(s)
- Santhosh Kumar Kannath
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Bejoy Thomas
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - P Sankara Sarma
- Achutha Menon Center for Health Sciences Studies, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Jayadevan Enakshy Rajan
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
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Srinivasan K, Thomas B, Shah D, Kannath SK, Menon G, Sandhyamani S, Kesavadas C, Kapilamoorthy TR. Quantification of diffusion and anisotropy in intracranial epidermoids using diffusion tensor metrics and p: q tensor decomposition. J Neuroradiol 2016; 43:363-370. [PMID: 27318387 DOI: 10.1016/j.neurad.2016.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/22/2016] [Accepted: 02/24/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE To quantitatively evaluate the diffusion tensor metrics p, q, L and fractional anisotropy in intracranial epidermoids in comparison with normal white matter in the splenium of the corpus callosum. METHODS This retrospective study included 20 consecutive patients referred to our institute. All patients had a magnetic resonance imaging (MRI) study on a 1.5-Tesla MR system. A spin-echo echo-planar DTI sequence with diffusion gradients along 30 non-collinear directions was performed. The eigen values (λ1, λ2, λ3) were computed for each voxel and, using p: q tensor decomposition, the DTI metrics p, q and L-values and fractional anositropy (FA) were calculated. The region of interest (ROI) (6 pixels each) was placed within the lesion in all the cases and in the splenium of the corpus callosum. RESULTS The mean FA in the lesion and splenium were 0.50 and 0.88 respectively, with a statistically significant difference between them (P<0.01). On p: q tensor decomposition, the mean p-value in the epidermoid was 1.55±0.24 and 1.35±0.20 in the splenium; the mean q-values in the epidermoid was 0.67±0.13 and 1.27±0.17 in the splenium; the differences were statistically significant (P=0.01 and <0.01 respectively). The significant difference between p- and q-values in epidermoids compared with the splenium of callosum was probably due to structural and orientation differences in the keratin flakes in epidermoids and white matter bundles in the callosum. However, no significant statistical difference in L-values was noted (P=0.44). CONCLUSION DTI metrics p and q have the potential to quantify the diffusion and anisotropy in various tissues thereby gaining information about their internal architecture. The results also suggest that significant differences of DTI metrics p and q between epidermoid and the splenium of the corpus callosum are due to the difference in structural organization within them.
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Affiliation(s)
- K Srinivasan
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology Trivandrum, India
| | - B Thomas
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology Trivandrum, India.
| | - D Shah
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology Trivandrum, India
| | - S K Kannath
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology Trivandrum, India
| | - G Menon
- Department of Neurosurgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - S Sandhyamani
- Department of Pathology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - C Kesavadas
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology Trivandrum, India
| | - T R Kapilamoorthy
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology Trivandrum, India
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Jain NK, Kannath SK, Kapilamoorthy TR, Thomas B. The application of susceptibility-weighted MRI in pre-interventional evaluation of intracranial dural arteriovenous fistulas. J Neurointerv Surg 2016; 9:502-507. [PMID: 27199382 DOI: 10.1136/neurintsurg-2016-012314] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 04/25/2016] [Accepted: 04/29/2016] [Indexed: 11/03/2022]
Abstract
BACKGROUND AND PURPOSE Detection and characterization of intracranial dural arteriovenous fistula (DAVF) is important to plan appropriate therapeutic management. The aim of this study was to analyze the utility of susceptibility-weighted MRI (SWI) in the pre-therapeutic assessment of DAVF in comparison with gold standard digital subtraction angiography (DSA). MATERIALS AND METHODS Prospectively, 26 patients with DAVFs underwent a thorough clinical examination and MRI including SWI followed by cerebral DSA. Two observers blinded to the DSA findings evaluated conventional MRI and SWI images and identified the fistulous area (FA), cortical venous reflux (CVR), and cortical venous ectasia (CVE) and compared these observations with the DSA findings documented by a third observer. RESULTS Aggressive clinical symptoms were observed in 31% of patients and benign features were noted in 69% of DAVFs. Conventional MRI could identify the FA in only 27% of patients. SWI accurately located 75% of all the FAs in 23 patients. However, SWI failed to identify DAVFs in three patients. CVR was detected in 89.6% of all aggressive DAVFs. The accuracy of SWI to identify CVE was 100% and the extent and degree correlated with DSA observations. CONCLUSIONS SWI is a reliable non-invasive tool for the localization and characterization of DAVFs and is superior to conventional MRI in the evaluation of DAVFs. This sequence can demonstrate underlying cerebral hemodynamic stresses with a high degree of accuracy and provide valuable pre-therapeutic information.
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Affiliation(s)
- Narendra Kumar Jain
- Department of Imaging sciences and Interventional Radiology, Sree Chitra Thirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Santhosh Kumar Kannath
- Department of Imaging sciences and Interventional Radiology, Sree Chitra Thirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Tirur Raman Kapilamoorthy
- Department of Imaging sciences and Interventional Radiology, Sree Chitra Thirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
| | - Bejoy Thomas
- Department of Imaging sciences and Interventional Radiology, Sree Chitra Thirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India
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Kannath SK, Alampath P, Enakshy Rajan J, Thomas B, Sankara Sarma P, Tirur Raman K. Utility of 3D SPACE T2-weighted volumetric sequence in the localization of spinal dural arteriovenous fistula. J Neurosurg Spine 2016; 25:125-32. [PMID: 26943253 DOI: 10.3171/2015.8.spine141322] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The aim of this study was to investigate the utility of a heavily T2-weighted volumetric MRI sequence (3D sampling perfection with application-optimized contrasts using different flip-angle evolutions [SPACE]) in the feeder localization of spinal dural arteriovenous fistula (SDAVF). METHODS Patients who were diagnosed with SDAVF and who had 3D SPACE source images available for review were identified from a retrospective review of medical records. A total of 16 patients were identified, and MR images were analyzed separately by 2 blinded observers. The accuracy of the observation and interobserver agreement were measured by Kendall's tau and kappa statistics. RESULTS The site of fistula was accurately predicted by Observers 1 and 2 in 81% and 88% of cases, respectively, which improved to 94% when the level was considered within 1 vertebral level. The observer agreement with gold-standard angiography and interobserver agreement were found to be highly significant (p < 0.0001). CONCLUSIONS The 3D SPACE MRI sequence is valuable in the precise detection of the site of SDAVF. It may help to tailor digital subtraction angiography and thereby reduce the radiation exposure, contrast load, and study time.
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Affiliation(s)
| | - Praveen Alampath
- Department of Imaging Sciences and Interventional Radiology, and
| | | | - Bejoy Thomas
- Department of Imaging Sciences and Interventional Radiology, and
| | - P Sankara Sarma
- Achutha Menon Centre for Health Science Studies, Sree Chitra Institute for Medical Sciences and Technology, Trivandrum, India
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