title: Initial testing of a 3D printed perfusion phantom using digital subtraction angiography.
abstract: Perfusion imaging is the most applied modality for the assessment of acute stroke. Parameters such as Cerebral Blood Flow (CBF), Cerebral Blood volume (CBV) and Mean Transit Time (MTT) are used to distinguish the tissue infarct core and ischemic penumbra. Due to lack of standardization these parameters vary significantly between vendors and software even when provided with the same data set. There is a critical need to standardize the systems and make them more reliable. We have designed a uniform phantom to test and verify the perfusion systems. We implemented a flow loop with different flow rates (250, 300, 350 ml/min) and injected the same amount of contrast. The images of the phantom were acquired using a Digital Angiographic system. Since this phantom is uniform, projection images obtained using DSA is sufficient for initial validation. To validate the phantom we measured the contrast concentration at three regions of interest (arterial input, venous output, perfused area) and derived time density curves (TDC). We then calculated the maximum slope, area under the TDCs and flow. The maximum slope calculations were linearly increasing with increase in flow rate, the area under the curve decreases with increase in flow rate. There was 25% error between the calculated flow and measured flow. The derived TDCs were clinically relevant and the calculated flow, maximum slope and areas under the curve were sensitive to the measured flow. We have created a systematic way to calibrate existing perfusion systems and assess their reliability.
authors.affiliation: Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY ; Toshiba Stroke and Vascular Research Center, State University of New York at Buffalo, Buffalo, NY.
authors.forename: Rachel P
authors.initials: RP
authors.lastname: Wood
authors.affiliation: Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY ; Toshiba Stroke and Vascular Research Center, State University of New York at Buffalo, Buffalo, NY.
authors.forename: Parag
authors.initials: P
authors.lastname: Khobragade
authors.affiliation: Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY.
authors.forename: Leslie
authors.initials: L
authors.lastname: Ying
authors.affiliation: Department of Neurosurgery, State University of New York at Buffalo, Buffalo, NY ; Toshiba Stroke and Vascular Research Center, State University of New York at Buffalo, Buffalo, NY.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Snyder
authors.affiliation: Department of Nuclear Medicine, State University of New York at Buffalo, Buffalo, NY.
authors.forename: David
authors.initials: D
authors.lastname: Wack
authors.affiliation: Department of Neurosurgery, State University of New York at Buffalo, Buffalo, NY ; Toshiba Stroke and Vascular Research Center, State University of New York at Buffalo, Buffalo, NY.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Bednarek
authors.affiliation: Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY ; Department of Neurosurgery, State University of New York at Buffalo, Buffalo, NY ; Toshiba Stroke and Vascular Research Center, State University of New York at Buffalo, Buffalo, NY.
authors.forename: Stephen
authors.initials: S
authors.lastname: Rudin
authors.affiliation: Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY ; Department of Neurosurgery, State University of New York at Buffalo, Buffalo, NY ; Toshiba Stroke and Vascular Research Center, State University of New York at Buffalo, Buffalo, NY.
authors.forename: Ciprian N
authors.initials: CN
authors.lastname: Ionita
keywords: Cerebral blood flow (CBF); Cerebral blood volume (CBV); Digital subtraction Angiography (DSA); Fick Principle; Mean transit time (MTT); Perfusion Phantom; Perfusion systems; Time Density Curves (TDC)