TY  - JOUR
AB  - Objective: The combination of near-infrared fluorescence (NIRF) with intravascular ultrasound (IVUS) has shown promising applications for imaging atherosclerosis in ex vivo human arteries and in vivo animal models. However, long acquisition times, rotational distortion causing inconsistent image quality and poor catheter durability have hampered clinical translation. Technical limitations have included motor drive unit (MDU) instability, and catheter designs with a single-layer drive shaft and long rigid length of the distal tip. Methods: Herein, we present an improved, next-generation NIRF-IVUS system by integrating an aluminum v-block-based high-speed MDU and 3.0 French (∅ = 1.0mm) catheter with a dual-layer drive shaft and reduced rigid tip length. We show a sixfold increase in imaging speed (30 FPS, 6 mm/s pullback) mirroring speed capabilities of standalone, commercial IVUS imaging. Results: In phantoms, we find that key NIRF-IVUS specifications like co-registration, rotational stability and NIRF resolution/sensitivity are preserved. Furthermore, we demonstrate that NIRF-IVUS molecular imaging of cathepsin protease activity can highlight stent-induced arterial inflammation independent of imaging speed, in rabbits in vivo. We calculate similar (not significant, p = 0.65) NIRF target-to-background ratios (TBRs) in stented tissue areas at low-speed (1.88) and high-speed (2.00) imaging. Finally, in vivo NIRF-IVUS imaging of FDA-approved indocyanine green detects early-stage plaques in rabbit aorta not visible on standalone IVUS. Similar NIRF TBRs are calculated in low-speed (4.13) and high-speed (4.08) pullbacks. Conclusion and Significance: Our study demonstrates that NIRF-IVUS can highlight key pathobiological markers of atherosclerosis beyond standalone IVUS at clinical imaging speeds, further supporting the clinical translation of the NIRF-IVUS technology.
AU  - Rauschendorfer, P.*
AU  - Thrapp, A.*
AU  - Srinivas, A.*
AU  - Carleton, R.*
AU  - Mauskapf, A.*
AU  - Griffin, K.N.R.*
AU  - Ntziachristos, V.
AU  - Tearney, G.J.*
AU  - Jaffer, F.A.*
C1  - 75485
C2  - 58081
TI  - High-speed intravascular near-infrared fluorescence-ultrasound imaging In vivo.
JO  - IEEE Trans. Bio. Med. Eng.
PY  - 2025
SN  - 0018-9294
ER  - 

TY  - JOUR
AB  - Cine cardiac magnetic resonance (CMR) imaging is considered the gold standard for cardiac function evaluation. However, cine CMR acquisition is inherently slow and in recent decades considerable effort has been put into accelerating scan times without compromising image quality or the accuracy of derived results. In this article, we present a fully-automated, quality-controlled integrated framework for reconstruction, segmentation and downstream analysis of undersampled cine CMR data. The framework produces high quality reconstructions and segmentations, leading to undersampling factors that are optimised on a scan-by-scan basis. This results in reduced scan times and automated analysis, enabling robust and accurate estimation of functional biomarkers. To demonstrate the feasibility of the proposed approach, we perform simulations of radial k-space acquisitions using in-vivo cine CMR data from 270 subjects from the UK Biobank (with synthetic phase) and in-vivo cine CMR data from 16 healthy subjects (with real phase). The results demonstrate that the optimal undersampling factor varies for different subjects by approximately 1 to 2 seconds per slice. We show that our method can produce quality-controlled images in a mean scan time reduced from 12 to 4 seconds per slice, and that image quality is sufficient to allow clinically relevant parameters to be automatically estimated to lie within 5% mean absolute difference.
AU  - Machado, I.*
AU  - Puyol-Antón, E.*
AU  - Hammernik, K.*
AU  - Cruz, G.*
AU  - Ugurlu, D.*
AU  - Olakorede, I.*
AU  - Öksüz, I.*
AU  - Ruijsink, B.*
AU  - Castelo-Branco, M.*
AU  - Young, A.*
AU  - Prieto, C.*
AU  - Schnabel, J.A.
AU  - King, A.*
C1  - 70507
C2  - 55524
CY  - 445 Hoes Lane, Piscataway, Nj 08855-4141 Usa
SP  - 855-865
TI  - A deep learning-based integrated framework for quality-aware undersampled cine cardiac MRI reconstruction and analysis.
JO  - IEEE Trans. Bio. Med. Eng.
VL  - 71
IS  - 3
PB  - Ieee-inst Electrical Electronics Engineers Inc
PY  - 2024
SN  - 0018-9294
ER  - 

TY  - JOUR
AB  - Objective: Fluorescence molecular imaging (FMI) has emerged as a promising tool for surgical guidance in oncology, with one of the few remaining challenges being the ability to offer quality control and data referencing. This paper investigates the use of a novel composite phantom to correct and benchmark FMI systems. Methods: This paper extends on previous work by describing a phantom design that can provide a more complete assessment of FMI systems through quantification of dynamic range and determination of spatial illumination patterns for both reflectance and fluorescence imaging. Various performance metrics are combined into a robust and descriptive "system benchmarking score," enabling not only the comprehensive comparison of different systems, but also for the first time, correction of the acquired data. Results: We show that systems developed for targeted fluorescence imaging can achieve benchmarking scores of up to 70 & x0025;, while clinically available systems optimized for indocyanine green are limited to 50 & x0025;, mostly due to greater leakage of ambient and excitation illumination and lower resolution. The image uniformity can also be approximated and employed for image flat-fielding, an important milestone toward data referencing. In addition, we demonstrate composite phantom use in assessing the performance of a surgical microscope and of a raster-scan imaging system. Conclusion: Our results suggest that the new phantom has the potential to support high-fidelity FMI through benchmarking and image correction. Significance: Standardization of the FMI is a necessary process for establishing good imaging practices in clinical environments and for enabling high-fidelity imaging across patients and multi-center imaging studies.
AU  - Gorpas, D.
AU  - Koch, M.
AU  - Anastasopoulou, M.
AU  - Bozhko, D.
AU  - Klemm, U.
AU  - Nieberler, M.*
AU  - Ntziachristos, V.
C1  - 57772
C2  - 47879
CY  - 445 Hoes Lane, Piscataway, Nj 08855-4141 Usa
SP  - 185-192
TI  - Multi-parametric standardization of fluorescence imaging systems based on a composite phantom.
JO  - IEEE Trans. Bio. Med. Eng.
VL  - 67
IS  - 1
PB  - Ieee-inst Electrical Electronics Engineers Inc
PY  - 2020
SN  - 0018-9294
ER  - 

TY  - JOUR
AB  - Objective: Optoacoustic (photoacoustic) tomography is aimed at reconstructing maps of the initial pressure rise induced by the absorption of light pulses in tissue. In practice, due to inaccurate assumptions in the forward model, noise, and other experimental factors, the images are often afflicted by artifacts, occasionally manifested as negative values. The aim of this work is to develop an inversion method which reduces the occurrence of negative values and improves the quantitative performance of optoacoustic imaging. Methods: We present a novel method for optoacoustic tomography based on an entropy maximization algorithm, which uses logarithmic regularization for attaining non-negative reconstructions. The reconstruction image quality is further improved using structural prior-based fluence correction. Results: We report the performance achieved by the entropy maximization scheme on numerical simulation, experimental phantoms, and in-vivo samples. Conclusion: The proposed algorithm demonstrates superior reconstruction performance by delivering non-negative pixel values with no visible distortion of anatomical structures. Significance: Our method can enable quantitative optoacoustic imaging, and has the potential to improve preclinical and translational imaging applications.
AU  - Prakash, J.
AU  - Mandal, S.
AU  - Razansky, D.
AU  - Ntziachristos, V.
C1  - 55659
C2  - 46377
CY  - 445 Hoes Lane, Piscataway, Nj 08855-4141 Usa
SP  - 2604-2616
TI  - Maximum entropy based non-negative optoacoustic tomographic image reconstruction.
JO  - IEEE Trans. Bio. Med. Eng.
VL  - 66
IS  - 9
PB  - Ieee-inst Electrical Electronics Engineers Inc
PY  - 2019
SN  - 0018-9294
ER  - 

TY  - JOUR
AB  - Intravascular ultrasound (IVUS) is the predominant imaging modality in the field of interventional cardiology that provides real-time cross-sectional images of coronary arteries and the extent of atherosclerosis. Due to heterogeneity of lesions and stringent spatial/spectral behavior of tissues, atherosclerotic plaque characterization has always been a challenge and still is an open problem. In this paper, we present a systematic framework from in vitro data collection, histology preparation, IVUS-histology registration along with matching procedure, and finally a robust texture-derived unsupervised atherosclerotic plaque labeling. We have performed our algorithm on in vitro and in vivo images acquired with single-element 40 MHz and 64-elements phased array 20 MHz transducers, respectively. In former case, we have quantified results by local contrasting of constructed tissue colormaps with corresponding histology images employing an independent expert and in the latter case, virtual histology images have been utilized for comparison. We tackle one of the main challenges in the field that is the reliability of tissues behind arc of calcified plaques and validate the results through a novel random walks framework by incorporating underlying physics of ultrasound imaging. We conclude that proposed framework is a formidable approach for retrieving imperative information regarding tissues and building a reliable training dataset for supervised classification and its extension for in vivo applications.
AU  - Katouzian, A.*
AU  - Karamalis, A.*
AU  - Sheet, D.*
AU  - Konofagou, E.*
AU  - Baseri, B.*
AU  - Carlier, S.G.*
AU  - Eslami, A.
AU  - König, A.*
AU  - Navab, N.*
AU  - Laine, A.F.*
C1  - 26356
C2  - 32190
SP  - 3039-3049
TI  - Iterative self-organizing atherosclerotic tissue labeling in intravascular ultrasound images and comparison with virtual histology.
JO  - IEEE Trans. Bio. Med. Eng.
VL  - 59
IS  - 11
PB  - IEEE
PY  - 2012
SN  - 0018-9294
ER  - 

TY  - JOUR
AU  - Gogou, G.*
AU  - Mavromatis, A.*
AU  - Maglaveras, N.*
AU  - Engelbrecht, R.
AU  - Pappas, C.*
C1  - 22144
C2  - 20832
SP  - 1412-1419
TI  - DIABCARD CCMIS - A Portable and Scalable CPR for Diabetes Care.
JO  - IEEE Trans. Bio. Med. Eng.
VL  - 49
PY  - 2002
SN  - 0018-9294
ER  -