Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage: Proposal of an Evidence-Based Combined Clinical and Imaging Reference Standard

Aneurysmal subarachnoid hemorrhage is associated with high morbidity and mortality, with delayed neurologic deficits from delayed cerebral ischemia contributing to a large portion of the adverse outcomes in this patient population. There is currently no consensus reference standard for establishing the diagnosis of delayed cerebral ischemia either in the research or clinical settings, ultimately limiting strategies for preventing delayed infarction and permanent neurologic deficits. There are currently both clinical and imaging-based criteria for the diagnosis of delayed neurologic deficits and vasospasm, respectively, however, neither clinical nor angiographic assessment alone has been shown to identify patients who develop adverse outcomes from delayed infarction. Thus, the purpose of this work is to propose a 3-tiered combined imaging and clinical reference standard based on evidence from the literature to standardize the diagnosis of delayed cerebral ischemia, both to allow consistency across research studies and to ultimately improve outcomes in the clinical setting

Cost-effectiveness of CT angiography and perfusion imaging for delayed cerebral ischemia and vasospasm in aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE: Delayed cerebral ischemia and vasospasm are significant complications following SAH leading to cerebral infarction, functional disability, and death. In recent years, CTA and CTP have been used to increase the detection of delayed cerebral ischemia and vasospasm. Our aim was to perform comparative-effectiveness and cost-effectiveness analyses evaluating CTA and CTP for delayed cerebral ischemia and vasospasm in aneurysmal SAH from a health care payer perspective. MATERIALS AND METHODS: We developed a decision model comparing CTA and CTP with transcranial Doppler sonography for detection of vasospasm and delayed cerebral ischemia in SAH. The clinical pathways were based on the "Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage: A Guideline for Healthcare Professionals from the American Heart Association/American Stroke Association" (2012). Outcome health states represented mortality and morbidity according to functional outcomes. Input probabilities of symptoms and serial test results from CTA and CTP, transcranial Doppler ultrasound, and digital subtraction angiography were directly derived from an SAH cohort by using a multinomial logistic regression model. Expected benefits, measured as quality-adjusted life years, and costs, measured in 2012 US dollars, were calculated for each imaging strategy. Univariable, multivariable, and probabilistic sensitivity analyses were performed to determine the independent and combined effect of input parameter uncertainty. RESULTS: The transcranial Doppler ultrasound strategy yielded 13.62 quality-adjusted life years at a cost of $154,719. The CTA and CTP strategy generated 13.89 quality-adjusted life years at a cost of$147,097, resulting in a gain of 0.27 quality-adjusted life years and cost savings of $7622 over the transcranial Doppler ultrasound strategy. Univariable and multivariable sensitivity analyses indicated that results were robust to plausible input parameter uncertainty. Probabilistic sensitivity analysis results yielded 96.8% of iterations in the right lower quadrant, representing higher benefits and lower costs. CONCLUSIONS: Our model results suggest that CTA and CTP are the preferred imaging strategy in SAH, compared with transcranial Doppler ultrasound, leading to improved clinical outcomes and lower health care costs

Tissue-specific sparse deconvolution for low-dose CT perfusion.

Medical image computing and computer-assisted intervention : MICCAI ... International Conference on Medical Image Computing and Computer-Assisted Intervention16Pt 1114-12

Sparsity-based deconvolution of low-dose brain perfusion CT in subarachnoid hemorrhage patients

10.1109/ISBI.2012.6235687Proceedings - International Symposium on Biomedical Imaging872-87

Towards robust deconvolution of low-dose perfusion CT: Sparse perfusion deconvolution using online dictionary learning

10.1016/j.media.2013.02.005Medical Image Analysis174417-428MIAE

Sparsity-based deconvolution of low-dose perfusion CT using learned dictionaries

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)7510 LNCS272-28

Tissue-specific sparse deconvolution for low-dose CT perfusion

10.1007/978-3-642-40811-3_15Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)8149 LNCSPART 1114-12

Tensor total-variation regularized deconvolution kegularlzea ueconvolution for efficient low-dose CT perfusion.

Medical image computing and computer-assisted intervention : MICCAI ... International Conference on Medical Image Computing and Computer-Assisted Intervention17Pt 1154-16

Improving low-dose blood-brain barrier permeability quantification using sparse high-dose induced prior for Patlak model

10.1016/j.media.2013.09.008Medical Image Analysis186866-880MIAE

Robust Low-Dose CT Perfusion Deconvolution via Tensor Total-Variation Regularization

10.1109/TMI.2015.2405015IEEE Transactions on Medical Imaging3471533-1548ITMI