Cristian Tudorel Badea

Journal article Phys Med Biol · July 18, 2022 Featured Work Objective.Photon-counting CT (PCCT) has better dose efficiency and spectral resolution than energy-integrating CT, which is advantageous for material decomposition. Unfortunately, the accuracy of PCCT-based material decomposition is limited due to spectral ... Full text Open Access Link to item Cite

Photon Counting CT and Radiomic Analysis Enables Differentiation of Tumors Based on Lymphocyte Burden.

Journal article Tomography · March 10, 2022 Featured Work The purpose of this study was to investigate if radiomic analysis based on spectral micro-CT with nanoparticle contrast-enhancement can differentiate tumors based on lymphocyte burden. High mutational load transplant soft tissue sarcomas were initiated in ... Full text Open Access Link to item Cite

Detection of Lung Nodules in Micro-CT Imaging Using Deep Learning.

Journal article Tomography · August 7, 2021 Featured Work We are developing imaging methods for a co-clinical trial investigating synergy between immunotherapy and radiotherapy. We perform longitudinal micro-computed tomography (micro-CT) of mice to detect lung metastasis after treatment. This work explores deep ... Full text Open Access Link to item Cite

Advances in micro-CT imaging of small animals.

Journal article Phys Med · August 2021 Featured Work PURPOSE: Micron-scale computed tomography (micro-CT) imaging is a ubiquitous, cost-effective, and non-invasive three-dimensional imaging modality. We review recent developments and applications of micro-CT for preclinical research. METHODS: Based on a comp ... Full text Open Access Link to item Cite

Dual source hybrid spectral micro-CT using an energy-integrating and a photon-counting detector.

Journal article Phys Med Biol · October 21, 2020 Featured Work Preclinical micro-CT provides a hotbed in which to develop new imaging technologies, including spectral CT using photon counting detector (PCD) technology. Spectral imaging using PCDs promises to expand x-ray CT as a functional imaging modality, capable of ... Full text Open Access Link to item Cite

MRI-Based Deep Learning Segmentation and Radiomics of Sarcoma in Mice.

Journal article Tomography · March 2020 Featured Work Small-animal imaging is an essential tool that provides noninvasive, longitudinal insight into novel cancer therapies. However, considerable variability in image analysis techniques can lead to inconsistent results. We have developed quantitative imaging f ... Full text Open Access Link to item Cite

Bridging the translational gap: Implementation of multimodal small animal imaging strategies for tumor burden assessment in a co-clinical trial.

Journal article PLoS One · 2019 Featured Work In designing co-clinical cancer studies, preclinical imaging brings unique challenges that emphasize the gap between man and mouse. Our group is developing quantitative imaging methods for the preclinical arm of a co-clinical trial studying immunotherapy a ... Full text Open Access Link to item Cite

Photon-counting cine-cardiac CT in the mouse.

Journal article PLoS One · 2019 Featured Work The maturation of photon-counting detector (PCD) technology promises to enhance routine CT imaging applications with high-fidelity spectral information. In this paper, we demonstrate the power of this synergy and our complementary reconstruction techniques ... Full text Open Access Link to item Cite

Dual-Energy CT Imaging of Tumor Liposome Delivery After Gold Nanoparticle-Augmented Radiation Therapy.

Journal article Theranostics · 2018 Featured Work Gold nanoparticles (AuNPs) are emerging as promising agents for both cancer therapy and computed tomography (CT) imaging. AuNPs absorb x-rays and subsequently release low-energy, short-range photoelectrons during external beam radiation therapy (RT), incre ... Full text Open Access Link to item Cite

Spectrotemporal CT data acquisition and reconstruction at low dose.

Journal article Med Phys · November 2015 Featured Work PURPOSE: X-ray computed tomography (CT) is widely used, both clinically and preclinically, for fast, high-resolution anatomic imaging; however, compelling opportunities exist to expand its use in functional imaging applications. For instance, spectral info ... Full text Open Access Link to item Cite

In vivo small animal micro-CT using nanoparticle contrast agents.

Journal article Front Pharmacol · 2015 Featured Work Computed tomography (CT) is one of the most valuable modalities for in vivo imaging because it is fast, high-resolution, cost-effective, and non-invasive. Moreover, CT is heavily used not only in the clinic (for both diagnostics and treatment planning) but ... Full text Open Access Link to item Cite

Micro-CT of rodents: state-of-the-art and future perspectives.

Journal article Phys Med · September 2014 Featured Work Micron-scale computed tomography (micro-CT) is an essential tool for phenotyping and for elucidating diseases and their therapies. This work is focused on preclinical micro-CT imaging, reviewing relevant principles, technologies, and applications. Commonly ... Full text Open Access Link to item Cite

High-Resolution CT for Small-Animal Imaging Research

Book section · July 25, 2014 Featured Work Preclinical imaging has a critical role in phenotyping, in drug discovery, and in providing a basic understanding of mechanisms of disease. Translating imaging methods from humans to small animals is not an easy task. The purpose of this work is to review ... Full text Open Access Link to item Cite

Assessing cardiac injury in mice with dual energy-microCT, 4D-microCT, and microSPECT imaging after partial heart irradiation.

Journal article Int J Radiat Oncol Biol Phys · March 1, 2014 Featured Work PURPOSE: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging ... Full text Open Access Link to item Cite

Dual-energy micro-CT functional imaging of primary lung cancer in mice using gold and iodine nanoparticle contrast agents: a validation study.

Journal article PLoS One · 2014 Featured Work PURPOSE: To provide additional functional information for tumor characterization, we investigated the use of dual-energy computed tomography for imaging murine lung tumors. Tumor blood volume and vascular permeability were quantified using gold and iodine ... Full text Open Access Link to item Cite

Anatomical and functional imaging of myocardial infarction in mice using micro-CT and eXIA 160 contrast agent.

Journal article Contrast Media Mol Imaging · 2014 Featured Work Noninvasive small animal imaging techniques are essential for evaluation of cardiac disease and potential therapeutics. A novel preclinical iodinated contrast agent called eXIA 160 has recently been developed, which has been evaluated for micro-CT cardiac ... Full text Link to item Cite

Dual-energy micro-computed tomography imaging of radiation-induced vascular changes in primary mouse sarcomas.

Journal article Int J Radiat Oncol Biol Phys · April 1, 2013 Featured Work PURPOSE: To evaluate the effects of radiation therapy on primary tumor vasculature using dual-energy (DE) micro-computed tomography (micro-CT). METHODS AND MATERIALS: Primary sarcomas were generated with mutant Kras and p53. Unirradiated tumors were compar ... Full text Link to item Cite

In vivo characterization of tumor vasculature using iodine and gold nanoparticles and dual energy micro-CT.

Journal article Phys Med Biol · March 21, 2013 Featured Work Tumor blood volume and vascular permeability are well established indicators of tumor angiogenesis and important predictors in cancer diagnosis, planning and treatment. In this work, we establish a novel preclinical imaging protocol which allows quantitati ... Full text Link to item Cite

Registration-based segmentation of murine 4D cardiac micro-CT data using symmetric normalization.

Journal article Phys Med Biol · October 7, 2012 Featured Work Micro-CT can play an important role in preclinical studies of cardiovascular disease because of its high spatial and temporal resolution. Quantitative analysis of 4D cardiac images requires segmentation of the cardiac chambers at each time point, an extrem ... Full text Link to item Cite

Temporal and spectral imaging with micro-CT.

Journal article Med Phys · August 2012 Featured Work PURPOSE: Micro-CT is widely used for small animal imaging in preclinical studies of cardiopulmonary disease, but further development is needed to improve spatial resolution, temporal resolution, and material contrast. We present a technique for visualizing ... Full text Link to item Cite

Dual-energy micro-CT of the rodent lung.

Journal article Am J Physiol Lung Cell Mol Physiol · May 15, 2012 Featured Work The purpose of this work is to investigate the use of dual-energy micro-computed tomography (CT) for the estimation of vascular, tissue, and air fractions in rodent lungs using a postreconstruction three material decomposition method. Using simulations, we ... Full text Link to item Cite

Denoising of 4D Cardiac Micro-CT Data Using Median-Centric Bilateral Filtration.

Conference Proc SPIE Int Soc Opt Eng · February 23, 2012 Featured Work Bilateral filtration has proven an effective tool for denoising CT data. The classic filter utilizes Gaussian domain and range weighting functions in 2D. More recently, other distributions have yielded more accurate results in specific applications, and th ... Full text Link to item Cite

4D micro-CT using fast prospective gating.

Journal article Phys Med Biol · January 7, 2012 Featured Work Micro-CT is currently used in preclinical studies to provide anatomical information. But, there is also significant interest in using this technology to obtain functional information. We report here a new sampling strategy for 4D micro-CT for functional ca ... Full text Link to item Cite

Computed tomography imaging of primary lung cancer in mice using a liposomal-iodinated contrast agent.

Journal article PLoS One · 2012 Featured Work PURPOSE: To investigate the utility of a liposomal-iodinated nanoparticle contrast agent and computed tomography (CT) imaging for characterization of primary nodules in genetically engineered mouse models of non-small cell lung cancer. METHODS: Primary lun ... Full text Open Access Link to item Cite

Investigations on X-ray luminescence CT for small animal imaging.

Conference Proc SPIE Int Soc Opt Eng · 2012 Featured Work X-ray Luminescence CT (XLCT) is a hybrid imaging modality combining x-ray and optical imaging in which x-ray luminescent nanophosphors (NPs) are used as emissive imaging probes. NPs are easily excited using common CT energy x-ray beams, and the NP luminesc ... Full text Link to item Cite

High-resolution reconstruction of fluorescent inclusions in mouse thorax using anatomically guided sampling and parallel Monte Carlo computing.

Journal article Biomed Opt Express · September 1, 2011 Featured Work We present a method for high-resolution reconstruction of fluorescent images of the mouse thorax. It features an anatomically guided sampling method to retrospectively eliminate problematic data and a parallel Monte Carlo software package to compute the Ja ... Full text Open Access Link to item Cite

4D micro-CT for cardiac and perfusion applications with view under sampling.

Journal article Phys Med Biol · June 7, 2011 Featured Work Micro-CT is commonly used in preclinical studies to provide anatomical information. There is growing interest in obtaining functional measurements from 4D micro-CT. We report here strategies for 4D micro-CT with a focus on two applications: (i) cardiac ima ... Full text Link to item Cite

Evaluation of tumor microenvironment in an animal model using a nanoparticle contrast agent in computed tomography imaging.

Journal article Acad Radiol · January 2011 Featured Work RATIONALE AND OBJECTIVES: Non-invasive longitudinal imaging of tumor vasculature could provide new insights into the development of solid tumors, facilitating efficient delivery of therapeutics. In this study, we report three-dimensional imaging and charac ... Full text Link to item Cite

Phenylephrine-modulated cardiopulmonary blood flow measured with use of X-ray digital subtraction angiography.

Journal article J Pharmacol Toxicol Methods · 2011 Featured Work INTRODUCTION: Cardiopulmonary blood flow is an important indicator of organ function. Limitations in measuring blood flow in live rodents suggest that rapid physiological changes may be overlooked. For instance, relative measurements limit imaging to whole ... Full text Link to item Cite

In vivo imaging of rat coronary arteries using bi-plane digital subtraction angiography.

Journal article J Pharmacol Toxicol Methods · 2011 Featured Work INTRODUCTION: X-ray based digital subtraction angiography (DSA) is a common clinical imaging method for vascular morphology and function. Coronary artery characterization is one of its most important applications. We show that bi-plane DSA of rat coronary ... Full text Link to item Cite

Micro-CT imaging assessment of dobutamine-induced cardiac stress in rats.

Journal article J Pharmacol Toxicol Methods · 2011 Featured Work INTRODUCTION: Dobutamine (DOB) stress in animal models of heart disease has been imaged so far using echocardiography and magnetic resonance imaging. The purpose of this study was to assess normal response to DOB stress in rats using anatomical and functio ... Full text Link to item Cite

Phase-selective image reconstruction of the lungs in small animals using Micro-CT.

Journal article Proc SPIE Int Soc Opt Eng · February 15, 2010 Featured Work Gating in small animal imaging can compensate for artifacts due to physiological motion. This paper presents a strategy for sampling and image reconstruction in the rodent lung using micro-CT. The approach involves rapid sampling of free-breathing mice wit ... Full text Link to item Cite

Free-space fluorescence tomography with adaptive sampling based on anatomical information from microCT.

Conference Proc SPIE Int Soc Opt Eng · 2010 Featured Work Image reconstruction is one of the main challenges for fluorescence tomography. For in vivo experiments on small animals, in particular, the inhomogeneous optical properties and irregular surface of the animal make free-space image reconstruction challengi ... Full text Link to item Cite

Lung perfusion imaging in small animals using 4D micro-CT at heartbeat temporal resolution.

Journal article Med Phys · January 2010 Featured Work PURPOSE: Quantitative in vivo imaging of lung perfusion in rodents can provide critical information for preclinical studies. However, the combined challenges of high temporal and spatial resolution have made routine quantitative perfusion imaging difficult ... Full text Link to item Cite

Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography.

Journal article Med Phys · November 2009 Featured Work PURPOSE: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progressi ... Full text Link to item Cite

Effects of sampling strategy on image quality in noncontact panoramic fluorescence diffuse optical tomography for small animal imaging.

Journal article Opt Express · March 30, 2009 Featured Work Fluorescence diffuse optical tomography is an emerging technology for molecular imaging with recent technological advances in biomarkers and photonics. The introduction of noncontact imaging methods enables very large-scale data acquisition that is orders ... Full text Link to item Cite

Development of a noncontact 3-D fluorescence tomography system for small animal in vivo imaging.

Conference Proc SPIE Int Soc Opt Eng · February 16, 2009 Featured Work Fluorescence imaging is an important tool for tracking molecular-targeting probes in preclinical studies. It offers high sensitivity, but nonetheless low spatial resolution compared to other leading imaging methods such CT and MRI. We demonstrate our metho ... Full text Link to item Cite

Micro-CT imaging of breast tumors in rodents using a liposomal, nanoparticle contrast agent.

Journal article Int J Nanomedicine · 2009 Featured Work A long circulating liposomal, nanoscale blood pool agent encapsulating traditional iodinated contrast agent (65 mg I/mL) was used for micro-computed tomography (CT) imaging of rats implanted with R3230AC mammary carcinoma. Three-dimensional vascular archit ... Open Access Link to item Cite

A dual micro-CT system for small animal imaging.

Conference Proc SPIE Int Soc Opt Eng · April 18, 2008 Featured Work Micro-CT is a non-invasive imaging modality usually used to assess morphology in small animals. In our previous work, we have demonstrated that functional micro-CT imaging is also possible. This paper describes a dual micro-CT system with two fixed x-ray/d ... Full text Link to item Cite

A high-precision contrast injector for small animal x-ray digital subtraction angiography.

Journal article IEEE Trans Biomed Eng · March 2008 Featured Work The availability of genetically altered animal models of human disease for basic research has generated great interest in new imaging methodologies. Digital subtraction angiography (DSA) offers an appealing approach to functional imaging in small animals b ... Full text Link to item Cite

Sparseness prior based iterative image reconstruction for retrospectively gated cardiac micro-CT.

Journal article Med Phys · November 2007 Featured Work Recent advances in murine cardiac studies with three-dimensional (3D) cone beam micro-CT used a retrospective gating technique. However, this sampling technique results in a limited number of projections with an irregular angular distribution due to the te ... Full text Link to item Cite

High-resolution imaging of murine myocardial infarction with delayed-enhancement cine micro-CT.

Journal article Am J Physiol Heart Circ Physiol · June 2007 Featured Work The objective of this study was to determine the feasibility of delayed-enhancement micro-computed tomography (microCT) imaging to quantify myocardial infarct size in experimental mouse models. A total of 20 mice were imaged 5 or 35 days after surgical lig ... Full text Link to item Cite

Tomographic digital subtraction angiography for lung perfusion estimation in rodents.

Journal article Med Phys · May 2007 Featured Work In vivo measurements of perfusion present a challenge to existing small animal imaging techniques such as magnetic resonance microscopy, micro computed tomography, micro positron emission tomography, and microSPECT, due to combined requirements for high sp ... Full text Link to item Cite

Optimized radiographic spectra for small animal digital subtraction angiography.

Journal article Med Phys · November 2006 Featured Work The increasing use of small animals in basic research has spurred interest in new imaging methodologies. Digital subtraction angiography (DSA) offers a particularly appealing approach to functional imaging in the small animal. This study examines the optim ... Full text Link to item Cite

Three-dimensional imaging of xenograft tumors using optical computed and emission tomography.

Journal article Med Phys · September 2006 Featured Work The physical basis and preliminary applications of optical computed tomography (optical-CT) and optical emission computed tomography (optical-ECT) are introduced, as new techniques with potential to provide unique 3D information on a variety of aspects of ... Full text Link to item Cite

A liposomal nanoscale contrast agent for preclinical CT in mice.

Journal article AJR Am J Roentgenol · February 2006 Featured Work OBJECTIVE: The goal of this study was to determine if an iodinated, liposomal contrast agent could be used for high-resolution, micro-CT of low-contrast, small-size vessels in a murine model. MATERIALS AND METHODS: A second-generation, liposomal blood pool ... Full text Link to item Cite

Tumor imaging in small animals with a combined micro-CT/micro-DSA system using iodinated conventional and blood pool contrast agents.

Journal article Contrast Media Mol Imaging · 2006 Featured Work X-ray based micro-computed tomography (CT) and micro-digital subtraction angiography (DSA) are important non-invasive imaging modalities for following tumorogenesis in small animals. To exploit these imaging capabilities further, the two modalities were co ... Full text Link to item Cite

Imaging methods for morphological and functional phenotyping of the rodent heart.

Journal article Toxicol Pathol · 2006 Featured Work Small animal imaging has a critical role in phenotyping, drug discovery, and in providing a basic understanding of mechanisms of disease. Translating imaging methods from humans to small animals is not an easy task. The purpose of this work is to compare t ... Full text Link to item Cite

Effects of breathing and cardiac motion on spatial resolution in the microscopic imaging of rodents.

Journal article Magn Reson Med · April 2005 Featured Work One can acquire high-resolution pulmonary and cardiac images in live rodents with MR microscopy by synchronizing the image acquisition to the breathing cycle across multiple breaths, and gating to the cardiac cycle. The precision with which one can synchro ... Full text Link to item Cite

4-D micro-CT of the mouse heart.

Journal article Mol Imaging · 2005 Featured Work PURPOSE: Demonstrate noninvasive imaging methods for in vivo characterization of cardiac structure and function in mice using a micro-CT system that provides high photon fluence rate and integrated motion control. MATERIALS AND METHODS: Simultaneous cardia ... Full text Link to item Cite

Micro-CT with respiratory and cardiac gating.

Journal article Med Phys · December 2004 Featured Work Cardiopulmonary imaging in rodents using micro-computed tomography (CT) is a challenging task due to both cardiac and pulmonary motion and the limited fluence rate available from micro-focus x-ray tubes of most commercial systems. Successful imaging in the ... Full text Link to item Cite

Experiments with the nonlinear and chaotic behaviour of the multiplicative algebraic reconstruction technique (MART) algorithm for computed tomography.

Journal article Phys Med Biol · April 21, 2004 Featured Work Among the iterative reconstruction algorithms for tomography, the multiplicative algebraic reconstruction technique (MART) has two advantages that make it stand out from other algorithms: it confines the image (and therefore the projection data) to the con ... Full text Link to item Cite

Estimation of the heart respiratory motion with applications for cone beam computed tomography imaging: a simulation study.

Journal article IEEE Trans Inf Technol Biomed · December 2003 Featured Work Computed tomography (CT) reconstruction methods assume imaging of static objects; object movement during projection data acquisition causes tomogram artifacts. The continuously moving heart, therefore, represents a complicated imaging case. The associated ... Full text Link to item Cite

A novel approach for distortion correction for X-ray image intensifiers.

Journal article Comput Med Imaging Graph · 2003 Featured Work Applications of X-ray image intensifiers in medical imaging, include the use of fluoroscopic projection images to generate three-dimensional tomographic reconstructions. Unfortunately, the inherent distortions on the acquired projections deteriorate the qu ... Full text Link to item Cite

Logarithmic amplifier for computed tomography tasks using fluoroscopic projections.

Journal article J Med Eng Technol · 2002 Featured Work The image intensifier (II)-based imaging systems, as radiotherapy simulators or C-arm X-ray units, have also been used for image acquisition in computed tomography. When analogue-to-digital conversion is performed on the output signal of the television cam ... Full text Link to item Cite

Image quality in extended arc filtered digital tomosynthesis.

Journal article Acta Radiol · March 2001 Featured Work PURPOSE: To study image quality in filtered digital tomosynthesis (FDTS) tomograms as a function of their reconstruction arc, using isocentrically acquired, fluoroscopic projection data. MATERIAL AND METHODS: Both digital tomosynthesis (DTS) and cone beam ... Full text Link to item Cite

Three-dimensional localisation based on projectional and tomographic image correlation: an application for digital tomosynthesis.

Journal article Med Eng Phys · March 1999 Featured Work Accurate three-dimensional tumor localisation in Radiotherapy, is critical to the treatment outcome, particularly when high dose gradients are present. A number of techniques have been proposed for the localisation of anatomical structures or markers. The ... Full text Link to item Cite

A wavelet-based method for removal of out-of-plane structures in digital tomosynthesis.

Journal article Comput Med Imaging Graph · 1998 Featured Work Reconstructed images in digital tomosynthesis (DTS) are affected by artifacts due to blur from planes other than the fulcrum plane. A wavelet-based method has been developed for the discrimination and subsequent removal of unrelated structures from the rec ... Full text Link to item Cite

Medical device surveillance world-wide.

Journal article Stud Health Technol Inform · 1996 Featured Work Link to item Cite