I-STARS at CARS: Imaging at the CARS 30th Annual Congress and Exhibition

June 2, 2016

Members of the I-STAR Lab head to Heidelberg for the Computed Assisted Radiology and Surgery Exhibition to present their research in IGS, Image Reconstruction and 3D Image Registration.

Wojtek Zbijewski, PhD, presents “Quantification of bone microarchitecture in ultra-high resolution extremities cone-beam CT with a CMOS detector and compensation of patient motion”  (Thursday, June 23, 2016 Room 2 – 10:00am)

Jennifer Xu’s poster will present the latest work on “Cone-beam CT for point-of-care detection of acute intracranial hemorrhage.”  (Friday June 24th, 8:00-11:15am)

Joseph Goerres, PhD,  discusses “Atlas-based pedicle trajectory prediction for automatic assessment and guidance of screw insertions”  (Surgical/Interventional Informatics, Friday June 24th Room 1 – 10:00am)

Tharindu De Silva, PhD, presents a method to assist spine surgeons in target localization in his talk entitled “LevelCheck” Localization of Spinal Vertebrae in Intraoperative Radiographs from Preoperative MRI” (Friday, June 24th Room 2 – 11:00am)




The Carnegie Center of Surgical Innovation: A different kind of operation.

May 19, 2016

The Carnegie Center was highlighted in a recent BME newsletter.

For Jeff Siewerdsen, a professor of biomedical engineering, it was not hard to imagine such a synergistic connection between biomedical engineers and surgeons. “Clinical collaboration has always been the inspiration for our research,” he says. “What’s extraordinary is seeing that connection come to life in the same vintage operating rooms where so many landmark surgical procedures of the 20th century were pioneered.” The Carnegie Center for Surgical Innovation presents a unique resource for research, education, and translation that the departments of Neurosurgery and Biomedical Engineering hope will transform surgery, imaging science, and other disciplines in the 21st century.

“This is also a great example of the ‘one university’ concept championed by Johns Hopkins University President Ron Daniels,” says Siewerdsen, who collaborated with neurosurgery Professor Jean-Paul Wolinsky to create the center. “This space brings researchers from several departments to a focal point in the hospital with proximity to surgeons, identifying key clinical problems and working together to translate innovative solutions to clinical use.”

(link to full article  –  www. bme.jhu.edu/news-events)


PMB paper by Sarah Ouadah reports “self-calibration” of Zeego geometry for 3D imaging.

May 17, 2016

A paper entitled; “Self-calibration of cone-beam CT geometry using 3D-2D image registration” by Sarah Ouadah, recently published in Physics in Medicine and Biology, presents a method for geometric calibration of an arbitrary source-detector C-arm orbit by registering 2D projection data to a previously acquired 3D image.  This paper includes co-authors from Johns Hopkins Biomedical Engineering Department (JW Stayman, Grace Gang and Jeff Siewerdsen) and Siemens collaborator (Tina Ehtiati).

The algorithm uses information from the image gradients and a statistical optimizer to determine the transformation that provides in the best registration. The resulting transformation provides a “self-calibration” of system geometry. Using this algorithm, visible improvement was evident in CBCT reconstructions, particularly about high-contrast, high-frequency objects (e.g., temporal bone air cells and a surgical needle).


I-STAR Seminar: Dr. Ke Li on the Theoretical Applications of Four Dimensional Cascaded Systems Analysis of Cerebral CT Perfusion Imaging.

May 6, 2016

The I-STAR lab welcomes Dr. Ke Li for his seminar on Thursday, May 26th, entitled: Four-dimensional cascaded systems analysis of cerebral CT perfusion imaging: Theoretical framework and potential applications.

The recent success of clinical trials on endovascular stroke therapy has brought cerebral CT perfusion (CTP) imaging in the spotlight. CTP is used by many clinical centers for the diagnosis and prognosis of strokes, patient selection for endovascular therapy, and post-treatment evaluation. However, the exact role of CTP in endovascular therapy is somehow controversial, primarily due to the relatively large uncertainties in quantifying perfusion deficits from noisy CTP maps. This talk will present an imaging science framework that describes the signal and noise propagation process through each subcomponent of the CTP systems. The framework includes both deconvolution- and nondeconvolution-based postprocessing methods, and it covers different types of perfusion parameters such as cerebral blood flow and time-to-max. This framework has been used to identify the culprits for the poor imaging performance of the current CTP technology, and it has provided the needed scientific guidance for the development and optimization of several new CTP technologies, which potentially enables reliable quantification of perfusion deficits with reduced radiation dose.

Ke Li is a clinical health science (CHS)-track Assistant Professor of Medical Physics and Radiology, School of Medicine and Public Health, University of Wisconsin-Madison. He received his MS degree in Physics from the Ohio State University in 2009 and PhD in Medical Physics from UW-Madison in 2013. His major research interests include x-ray phase contrast breast imaging, cerebral CT perfusion imaging, and low dose body CT imaging. He has served as an ad hoc member of an NIH study section, guest associate
editor of Medical Physics, reviewer for PNAS, Scientific Reports, and other 8 journals. He is the recipient of the 2015 AAPM Research Seed Funding Initiative Award for a project entitled “High Quality and Sub-mSv Cerebral CT Perfusion Imaging.”

The seminar will be held on Thursday, May 26th at 1:00 pm in the Talbot Library (Traylor 709) on the School of Medicine campus.



Dr. Siewerdsen inducted in the AIMBE College of Fellows

April 21, 2016

Jeff Siewerdsen, Principal Investigator for the I-STAR Lab, Director of The Carnegie Center for Surgical Innovation, and Professor of BME at Hopkins, was recently inducted into the AIMBE College of Fellows for his contributions to biomedical imaging and image-guided interventions. The induction ceremony was held at the National Academy of Sciences in Washington DC on April 4, 2016. Induction in the College is based on nomination and peer review representing the top 1-2% of the engineering community.  The Fellows are instrumental in realizing the AIMBE vision for innovation and benefit to healthcare.

Congratulations, Dr. Siewerdsen, on this achievement!