scholarly journals Compressed sensing-based super-resolution ultrasound imaging for faster acquisition and high quality images

2020 ◽  
Author(s):  
Jihun Kim ◽  
Qingfei Wang ◽  
Siyuan Zhang ◽  
Sangpil Yoon
Keyword(s):  
Image Quality ◽  
Compressed Sensing ◽  
Ultrasound Imaging ◽  
Imaging Technique ◽  
Super Resolution ◽  
Tumor Model ◽  
Acquisition Time ◽  
Mouse Tumor ◽  
Conventional Ultrasound

AbstractSuper-resolution ultrasound (SRUS) imaging technique has overcome the diffraction limit of conventional ultrasound imaging, resulting in an improved spatial resolution while preserving imaging depth. Typical SRUS images are reconstructed by localizing ultrasound microbubbles (MBs) injected in a vessel using normalized 2-dimensional cross-correlation (2DCC) between MBs signals and the point spread function of the system. However, current techniques require isolated MBs in a confined area due to inaccurate localization of densely populated MBs. To overcome this limitation, we developed the ℓ1-homotopy based compressed sensing (L1H-CS) based SRUS imaging technique which localizes densely populated MBs to visualize microvasculature in vivo. To evaluate the performance of L1H-CS, we compared the performance of 2DCC, interior-point method based compressed sensing (CVX-CS), and L1H-CS algorithms. Localization efficiency was compared using axially and laterally aligned point targets (PTs) with known distances and randomly distributed PTs generated by simulation. We developed post-processing techniques including clutter reduction, noise equalization, motion compensation, and spatiotemporal noise filtering for in vivo imaging. We then validated the capabilities of L1H-CS based SRUS imaging technique with high-density MBs in a mouse tumor model, kidney, and zebrafish dorsal trunk, and brain. Compared to 2DCC, and CVX-CS algorithm, L1H-CS algorithm, considerable improvement in SRUS image quality and data acquisition time was achieved. These results demonstrate that the L1H-CS based SRUS imaging technique has the potential to examine the microvasculature with reduced acquisition and reconstruction time of SRUS image with enhanced image quality, which may be necessary to translate it into the clinics.

scholarly journals Molecular imaging of orthotopic prostate cancer with nanobubble ultrasound contrast agents targeted to PSMA

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Wang ◽  
Al Christopher De Leon ◽  
Reshani Perera ◽  
Eric Abenojar ◽  
Ramamurthy Gopalakrishnan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Ultrasound Imaging ◽  
Prostate Gland ◽  
Ultrasound Contrast Agent ◽  
Tumor Model ◽  
Focal Therapy ◽  
Ultrasound Contrast Agents ◽  
Time Intensity Curve ◽  
Ultrasound Contrast

AbstractUltrasound imaging is routinely used to guide prostate biopsies, yet delineation of tumors within the prostate gland is extremely challenging, even with microbubble (MB) contrast. A more effective ultrasound protocol is needed that can effectively localize malignancies for targeted biopsy or aid in patient selection and treatment planning for organ-sparing focal therapy. This study focused on evaluating the application of a novel nanobubble ultrasound contrast agent targeted to the prostate specific membrane antigen (PSMA-targeted NBs) in ultrasound imaging of prostate cancer (PCa) in vivo using a clinically relevant orthotopic tumor model in nude mice. Our results demonstrated that PSMA-targeted NBs had increased extravasation and retention in PSMA-expressing orthotopic mouse tumors. These processes are reflected in significantly different time intensity curve (TIC) and several kinetic parameters for targeted versus non-targeted NBs or LUMASON MBs. These, may in turn, lead to improved image-based detection and diagnosis of PCa in the future.

scholarly journals Accelerated 3D T2-Weighted SPACE Using Compressed Sensing for Paediatric Brain Imaging

2021 ◽  
Author(s):  
Hyun Gi Kim ◽  
Se Won Oh ◽  
Dongyeob Han ◽  
Jee Young Kim ◽  
Gye Yeon Lim
Keyword(s):  
White Matter ◽  
Image Quality ◽  
Compressed Sensing ◽  
Brain Imaging ◽  
Quality Analysis ◽  
Acquisition Time ◽  
Image Quality Analysis ◽  
Space Group ◽  
Quantitative Image ◽  
Noise Ratio

Abstract The purpose of this study was to compare the image quality of the single-slab, 3D T2-weighted turbo-spin-eco sequence with high sampling efficiency (SPACE) with accelerated SPACE using compressed sensing (CS-SPACE) in paediatric brain imaging. A total of 116 brain MRI (53 in SPACE group and 63 in CS-SPACE group) were obtained from children aged 16 years old or younger. Quantitative image quality was evaluated using the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The sequences were qualitatively evaluated for overall image quality, SNR, general artifact, cerebrospinal fluid (CSF)-related artifact and grey-white matter differentiation. The two sequences were compared for the total and for two age groups (< 24 months vs. ≥ 24 months). CS application in 3D T2-weighted imaging resulted in 8.5% reduction in scanning time. Quantitative image quality analysis showed higher SNR (Median [Interquartile range]; 29 [25] vs. 23 [14], P = .005) and CNR (0.231 [0.121] vs. 0.165 [0.120], P = .027) with CS-SPACE compared to SPACE. Qualitative image quality analysis showed better image quality with CS-SPACE for general artifact (P = .024) and CSF-related artifact (P < .001). CSF-related artifacts reduction was more prominent in the older age group (≥ 24 months). Overall image quality (P = .162), SNR (P = .726), and grey-white matter differentiation (P = .397) were comparable between SPACE and CS-SPACE. In conclusion, compressed sensing applied 3D T2-weighted images showed comparable or superior image quality compared to conventional images with reduced acquisition time for paediatric brain.

In-vivo near-infrared optical imaging of growing osteosarcoma cell lesions xenografted in mice: dual-channel quantitative evaluation of volume and mineralization

2011 ◽  
Vol 52 (9) ◽  
pp. 978-988 ◽  
Author(s):  
Hitoshi Nakayama ◽  
Tomoyuki Kawase ◽  
Kazuhiro Okuda ◽  
Larry F Wolff ◽  
Hiromasa Yoshie
Keyword(s):  
Optical Imaging ◽  
Near Infrared ◽  
Imaging Technique ◽  
Ex Vivo ◽  
Acquisition Time ◽  
Osteosarcoma Cell ◽  
Dual Channel ◽  
Nir Imaging ◽  
Ex Vivo Imaging

Background In a previous study using a rodent osteosarcoma-grafted rat model, in which cell-dependent mineralization was previously demonstrated to proportionally increase with growth, we performed a quantitative analysis of mineral deposit formation using 99mTc-HMDP and found some weaknesses, such as longer acquisition time and narrower dynamic ranges (i.e. images easily saturated). The recently developed near-infrared (NIR) optical imaging technique is expected to non-invasively evaluate changes in living small animals in a quantitative manner. Purpose To test the feasibility of NIR imaging with a dual-channel system as a better alternative for bone scintigraphy by quantitatively evaluating mineralization along with the growth of osteosarcoma lesions in a mouse-xenograft model. Material and Methods The gross volume and mineralization of osteosarcoma lesions were evaluated in living mice simultaneously with dual-channels by NIR dye-labeled probes, 2-deoxyglucose (DG) and pamidronate (OS), respectively. To verify these quantitative data, retrieved osteosarcoma lesions were then subjected to ex-vivo imaging, weighing under wet conditions, microfocus-computed tomography (μCT) analysis, and histopathological examination. Results Because of less scattering and no anatomical overlapping, as generally shown, specific fluorescence signals targeted to the osteosarcoma lesions could be determined clearly by ex-vivo imaging. These data were well positively correlated with the in-vivo imaging data ( r > 0.8, P < 0.02). Other good to excellent correlations ( r > 0.8, P < 0.02) were observed between DG accumulation and tumor gross volume and between OS accumulation and mineralization volume. Conclusion This in-vivo NIR imaging technique using DG and OS is sensitive to the level to simultaneously detect and quantitatively evaluate the growth and mineralization occuring in this type of osteosarcoma lesions of living mice without either invasion or sacrifice. By possible mutual complementation, this dual imaging system might be useful for accurate diagnosis even in the presence of overlapping tissues.

Super-resolution ultrasound imaging for in vivo microvasculature assessment in acute kidney injury mouse model

2019 ◽  
Vol 145 (3) ◽  
pp. 1859-1859
Author(s):  
Qiyang Chen ◽  
Brittney M. Rush ◽  
Jaesok Yu ◽  
Roderick Tan ◽  
Kang Kim
Keyword(s):  
Acute Kidney Injury ◽  
Mouse Model ◽  
Ultrasound Imaging ◽  
Kidney Injury ◽  
Super Resolution

scholarly journals Mesyl phosphoramidate backbone modified antisense oligonucleotides targeting miR-21 with enhanced in vivo therapeutic potency

2020 ◽  
Vol 117 (51) ◽  
pp. 32370-32379
Author(s):  
Olga A. Patutina ◽  
Svetlana K. Gaponova (Miroshnichenko) ◽  
Aleksandra V. Sen’kova ◽  
Innokenty A. Savin ◽  
Daniil V. Gladkikh ◽  
...  
Keyword(s):  
Tumor Model ◽  
Rnase H ◽  
Mouse Tumor ◽  
Internal Organs ◽  
Potent Inhibition ◽  
Nuclease Resistance ◽  
New Type

The design of modified oligonucleotides that combine in one molecule several therapeutically beneficial properties still poses a major challenge. Recently a new type of modified mesyl phosphoramidate (or µ-) oligonucleotide was described that demonstrates high affinity to RNA, exceptional nuclease resistance, efficient recruitment of RNase H, and potent inhibition of key carcinogenesis processes in vitro. Herein, using a xenograft mouse tumor model, it was demonstrated that microRNA miR-21–targeted µ-oligonucleotides administered in complex with folate-containing liposomes dramatically inhibit primary tumor growth via long-term down-regulation of miR-21 in tumors and increase in biosynthesis of miR-21–regulated tumor suppressor proteins. This antitumoral effect is superior to the effect of the corresponding phosphorothioate. Peritumoral administration of µ-oligonucleotide results in its rapid distribution and efficient accumulation in the tumor. Blood biochemistry and morphometric studies of internal organs revealed no pronounced toxicity of µ-oligonucleotides. This new oligonucleotide class provides a powerful tool for antisense technology.

scholarly journals Joint reconstruction framework of compressed sensing and nonlinear parallel imaging for dynamic cardiac magnetic resonance imaging

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhanqi Hu ◽  
Cailei Zhao ◽  
Xia Zhao ◽  
Lingyu Kong ◽  
Jun Yang ◽  
...  
Keyword(s):  
Compressed Sensing ◽  
Parallel Imaging ◽  
Imaging Technique ◽  
Temporal Variations ◽  
Cine Mri ◽  
Reconstruction Process ◽  
Parallel Imaging Technique ◽  
In Vivo Experiments ◽  
Space Data

AbstractCompressed Sensing (CS) and parallel imaging are two promising techniques that accelerate the MRI acquisition process. Combining these two techniques is of great interest due to the complementary information used in each. In this study, we proposed a novel reconstruction framework that effectively combined compressed sensing and nonlinear parallel imaging technique for dynamic cardiac imaging. Specifically, the proposed method decouples the reconstruction process into two sequential steps: In the first step, a series of aliased dynamic images were reconstructed from the highly undersampled k-space data using compressed sensing; In the second step, nonlinear parallel imaging technique, i.e. nonlinear GRAPPA, was utilized to reconstruct the original dynamic images from the reconstructed k-space data obtained from the first step. In addition, we also proposed a tailored k-space down-sampling scheme that satisfies both the incoherent undersampling requirement for CS and the structured undersampling requirement for nonlinear parallel imaging. The proposed method was validated using four in vivo experiments of dynamic cardiac cine MRI with retrospective undersampling. Experimental results showed that the proposed method is superior at reducing aliasing artifacts and preserving the spatial details and temporal variations, compared with the competing k-t FOCUSS and k-t FOCUSS with sensitivity encoding methods, with the same numbers of measurements.

scholarly journals Capabilities of multi-pinhole SPECT with two stationary detectors for in vivo rat imaging

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jan P. Janssen ◽  
Jan V. Hoffmann ◽  
Takayuki Kanno ◽  
Naoko Nose ◽  
Jan-Peter Grunz ◽  
...  
Keyword(s):  
Image Quality ◽  
Point Source ◽  
Single Photon ◽  
Photon Emission ◽  
Small Animal ◽  
Acquisition Time ◽  
Emission Computed Tomography ◽  
Scan Time ◽  
Spect System

Abstract We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available 99mTc-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with 99mTc-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with ~ 100 MBq [99mTc]Tc-MIBI or ~ 150 MBq [99mTc]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1 = “very poor” to 5 = “very good”. Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time.

scholarly journals Super-Resolution Ultrasound Imaging in Vivo with Transient Laser-Activated Nanodroplets

Nano Letters ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 2556-2559 ◽  
Author(s):  
Geoffrey P. Luke ◽  
Alexander S. Hannah ◽  
Stanislav Y. Emelianov
Keyword(s):  
Ultrasound Imaging ◽  
Super Resolution

scholarly journals Nuclear FOXP3 inhibits tumor growth and induced apoptosis in hepatocellular carcinoma by targeting c-Myc

Oncogenesis ◽  
2020 ◽  
Vol 9 (10) ◽  
Author(s):  
Zhongqin Gong ◽  
Hao Jia ◽  
Jianqing Yu ◽  
Yi Liu ◽  
Jianwei Ren ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Tumor Model ◽  
Inhibitory Effect ◽  
Luciferase Assay ◽  
Migration And Invasion ◽  
Mouse Tumor ◽  
Clinicopathologic Characteristics ◽  
Mouse Tumor Model ◽  
Inhibitory Function

Abstract The status of FOXP3 and its isoforms in hepatocellular carcinoma (HCC) is unclear. We aimed to investigate the expression and function of FOXP3 and its isoforms in HCC. The study was performed on 84 HCC patients, HCC cell lines and a mouse tumor model. The levels of FOXP3 and its isoforms were determined by nested PCR, quantitative real-time PCR and immunohistochemistry (IHC) staining. The correlation between their levels and clinicopathologic characteristics was analyzed. The full length of FOXP3 (FOXP3) and exon 3-deleted FOXP3 (FOXP3Δ3) were found to be the major isoforms in HCC. The levels of FOXP3Δ3 mRNA and protein in HCC tumor samples were not significantly different from their adjacent normal tissues. The high expression of FOXP3 protein in HCC patients showed a good overall survival. The overexpression of FOXP3 significantly reduced tumor cell proliferation, migration and invasion. The immunofluorescence result indicated that FOXP3 needed to be translocated into the nucleus to exert its inhibitory function. The luciferase assay demonstrated that FOXP3 could be synergistic with Smad2/3/4 to inhibit the oncogene c-Myc. The co-immunoprecipitation results further revealed that FOXP3 could interact with Smad2/3/4. The chromatin immunoprecipitation (ChIP) assay showed that both FOXP3 and Smad2/3/4 bound the promoter of the c-Myc to inhibit it. The in vivo mouse tumor model study confirmed the inhibitory effect of FOXP3. Collectively, the expression of tumor FOXP3 can inhibit the growth of HCC via suppressing c-Myc directly or indirectly via interacting with Smad2/3/4. Therefore, FOXP3 is a tumor suppressor in HCC.

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