News & Events
Photon Counting CT-based Stroke Imaging
Release time:May 23, 2019

Topic:Photon Counting CT-based Stroke Imaging

Speaker:Dr Ke Li, University of Wisconsin–Madison

Time: 11:00 AM, May 24

Venue: Room 416, Yifu Science Hall of Beihang University


Stroke is one of the leading causes of death worldwide. Differentiating between ischemic and hemorrhagic strokes is important since their treatment methods are vastly different. CT imaging plays a vital role in the clinical workup of acute stroke by providing information essential to accurately triage patients and expedite clinical decision making with regard to treatment. A typical CT imaging protocol for stroke workup consists of 1) a noncontrast CT (NCCT) of the head to determine the extent of established hemorrhagic or ischemic infarction and the risk for an ischemic stroke to transform into hemorrhagic infarction, 2) a CT angiography (CTA) of the head and neck to detect vessel occlusion and assess collateral blood supply, and 3) a cerebral CT perfusion (CTP) to identify hypoperfused but potentially salvageable brain tissue. The current multi-detector row CT (MDCT) technology is able to provide rapid and accurate diagnosis of established intracranial hemorrhage and large vessel occlusion. However, its capability in accurately predicting the risk of hemorrhagic transformation and identifying the occlusion of deep, penetrating end arteries is limited. Photon counting CT (PCCT) provides a hardware-based solution to the challenges that currently remain for MDCT-based stroke imaging: compared with conventional indirect conversion and energy-integrating CT detectors, the direct conversion mechanism employed by the photon counting detector (PCD) leads to better resolvability of small penetrating end arteries and microbleeds; the equal energy weighting mechanism employed by the PCD facilitates the identification of early development of infarction zone; the energy resolving capability of the PCD enables the quantification of absolute water content in brain parenchyma that is of strong predictive value for hemorrhagic transformation. This talk will present experimental demonstration of these potential benefits of PCCT in stroke imaging. Further, the talk will describe how a PCCT system can be tailored for specific stroke imaging tasks to generate NCCT and CTA images with the desired imaging performance.

Biography of the Speaker:

Ke Li is a Tenure Track Assistant Professor of Department of Medical Physics and Department of Radiology, University of Wisconsin-Madison (UWM). He received his doctorate of Philosophy specializing in Medical Physics from UWM in 2009. He has published 50 articles in peer-reviewed journals, and serves as Associate Editor of the famous journal Medical Physics. Dr Li is an awardee of the Department of Defense (DOD) Breast Cancer Research Program Breakthrough Award and the winner of the Best Paper Award for the SPIE Medical Imaging. His research interests include quantitative CT image quality assessment, the instrumentation of advanced x-ray CT imaging systems, x-ray phase contrast breast imaging, cerebrovascular CT imaging, and low dose body CT.

School of Biological Science and Medical Engineering