Michael S. Van Lysel
University of Wisconsin-Madison
Imaging phantomOpticsPhysicsRadiologyBiomedical engineeringTomosynthesisBeam (structure)IsocenterMaterials scienceGeometryFluoroscopyDigital subtraction angiographyMyocardial perfusion imagingCollimatorAngiographyNuclear medicineMathematicsImage noiseImage qualitySubtractionMedicineDetective quantum efficiencyImage processingDetector
33Publications
11H-index
419Citations
Publications 31
Newest
#1Bruce H. HasegawaH-Index: 7
#2Shaikh NaimuddinH-Index: 5
Last. Charles A. MistrettaH-Index: 62
view all 13 authors...
Although image quality in chest radiography can be improved dramatically with compensating attenuators, it is difficult to match attenuator geometry to that of the patient and to properly position the filter in the x -ray beam. We are developing a system which will fabricate a compensating filter specific for individual patient anatomy and position the filter automatically. A low -dose image is acquired from which the attenuator is designed using a hardwired algorithm. The attenuator then is typ...
#1Michael T. Tomkowiak (UW: University of Wisconsin-Madison)H-Index: 7
#2Amish N. Raval (UW: University of Wisconsin-Madison)H-Index: 21
Last. Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11
view all 5 authors...
Proper sizing of interventional devices to match coronary vessel dimensions improves procedural efficiency and therapeutic outcomes. We have developed a method that uses an inverse geometry x-ray fluoroscopy system [scanning beam digital x-ray (SBDX)] to automatically determine vessel dimensions from angiograms without the need for magnification calibration or optimal views. For each frame period (1/15th of a second), SBDX acquires a sequence of narrow beam projections and performs digital tomos...
Source
#1Yinghua Tao (UW: University of Wisconsin-Madison)H-Index: 3
#2Guang-Hong Chen (UW: University of Wisconsin-Madison)H-Index: 41
Last. Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11
view all 6 authors...
Purpose: Dynamic CT myocardial perfusion imaging has the potential to provide both functional and anatomical information regarding coronary artery stenosis. However, radiation dose can be potentially high due to repeated scanning of the same region. The purpose of this study is to investigate the use of statistical iterative reconstruction to improve parametric maps of myocardial perfusion derived from a low tube current dynamic CT acquisition. Methods: Four pigs underwent high (500 mA) and low ...
Source
#1Yinghua Tao (UW: University of Wisconsin-Madison)H-Index: 3
#2Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11
Last. Guang-Hong Chen (UW: University of Wisconsin-Madison)H-Index: 41
view all 4 authors...
Low tube current scanning in combination with HYPR (HighlY constrained backPRojection) noise reduction is a proposed method for low-dose time-resolved CT myocardial perfusion imaging. We report animal studies and simulations investigating the coronary angiographic information available in these scans. Four pigs were scanned at 100 rnA and 500 rnA. A HYPR coronary angiographic image was formed from each 100 rnA scan by producing a time-averaged composite image from cardiac cycles centered on the ...
Source
#1Michael T. Tomkowiak (UW: University of Wisconsin-Madison)H-Index: 7
#2Michael S. Van Lysel (UW: University of Wisconsin-Madison)H-Index: 11
Last. Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11
view all 3 authors...
Scanning Beam Digital X-ray (SBDX) is a low-dose inverse geometry fluoroscopic system for cardiac interventional procedures. The system performs x-ray tomosynthesis at multiple planes in each frame period and combines the tomosynthetic images into a projection-like composite image for fluoroscopic display. We present a novel method of stereoscopic imaging using SBDX, in which two slightly offset projection-like images are reconstructed from the same scan data by utilizing raw data from two diffe...
Source
#1Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11
#2Courtney L. Bateman (UW: University of Wisconsin-Madison)H-Index: 1
Last. Michael S. Van Lysel (UW: University of Wisconsin-Madison)H-Index: 11
view all 7 authors...
Purpose: This study describes a HighlY constrained backPRojection (HYPR) image processing method for the reduction of image noise in low tube current time-resolved CT myocardial perfusion scans. The effect of this method on myocardial time-attenuation curve noise and fidelity is evaluated in an animal model, using varying levels of tube current. Methods: CT perfusion scans of four healthy pigs (42–59 kg) were acquired at 500, 250, 100, 50, 25, and 10 mA on a 64-slice scanner (4 cm axial coverage...
Source
#1Bradley P. McCabe (UW: University of Wisconsin-Madison)H-Index: 2
#2Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11
Last. Michael S. Van Lysel (UW: University of Wisconsin-Madison)H-Index: 11
view all 4 authors...
Purpose: In this study, newly formulated XR-RV3 GafChromic® film was calibrated with National Institute of Standards and Technology (NIST) traceability for measurement of patient skin dose during fluoroscopically guided interventional procedures. Methods: The film was calibrated free-in-air to air kerma levels between 15 and 1100 cGy using four moderately filtered x-ray beam qualities (60, 80, 100, and 120 kVp). The calibration films were scanned with a commercial flatbed document scanner. Film ...
Source
#1Michael T. Tomkowiak (UW: University of Wisconsin-Madison)H-Index: 7
#2Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11
Last. Michael S. Van Lysel (UW: University of Wisconsin-Madison)H-Index: 11
view all 4 authors...
Purpose: Quantitative coronary angiography (QCA) can be used to support device size selection for cardiovascular interventions. The accuracy of QCA measurements using conventional x-ray fluoroscopy depends on proper calibration using a reference object and avoiding vessel foreshortening. The authors have developed a novel interventional device sizing method using the inverse geometry scanning-beam digital x-ray (SBDX) fluoroscopy system. The proposed method can measure the diameter and length of...
Source
#1Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11
#2Michael T. Tomkowiak (UW: University of Wisconsin-Madison)H-Index: 7
Last. Michael S. Van Lysel (UW: University of Wisconsin-Madison)H-Index: 11
view all 4 authors...
Purpose: Scanning beam digital x-ray (SBDX) is an inverse geometry fluoroscopic system with high dose efficiency and the ability to perform continuous real-time tomosynthesis at multiple planes. This study describes a tomosynthesis-based method for 3D tracking of high-contrast objects and present the first experimental investigation of cardiac catheter tracking using a prototype SBDX system. Methods: The 3D tracking algorithm utilizes the stack of regularly spaced tomosynthetic planes that are g...
Source
#1Michael A. Speidel (UW: University of Wisconsin-Madison)H-Index: 11
#2Augustus P. LowellH-Index: 1
Last. Michael S. Van Lysel (UW: University of Wisconsin-Madison)H-Index: 11
view all 4 authors...
The Scanning-Beam Digital X-ray (SBDX) system performs rapid scanning of a narrow x-ray beam using an electronically scanned focal spot and inverse beam geometry. SBDX's ability to perform real-time multi-plane tomosynthesis with high dose efficiency is well-suited to interventional procedures such as left atrial ablation, where precise knowledge of catheter positioning is desired and imaging times are long. We describe and evaluate techniques for frame-by-frame 3D localization of multiple cathe...
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