Read by QxMD icon Read

Quantitative imaging

Xiaohui Wang, Jun Zhang, Hubing Wu, Yumin Li, Peter S Conti, Kai Chen
Heat shock protein 90 (Hsp90) plays a vital role in the progress of malignant disease and elevated Hsp90 expression has been reported in pancreatic cancer. In this study, we radiolabeled a dimeric Sansalvamide A derivative (Di-San A1) with 64 Cu, and evaluated the feasibility of using 64 Cu-Di-San A1 for PET imaging of Hsp90 expression in a mouse model of pancreatic cancer. A macrocyclic chelator NOTA (1,4,7-triazacyclononane-1,4,7-trisacetic acid) was conjugated to Di-San A1. 64 Cu-Di-San A1 was successfully prepared in a radiochemical yield > 97% with a radiochemical purity > 98%...
April 24, 2018: Amino Acids
Motoyo Yano, Kathryn J Fowler, Santip Srisuwan, Amber Salter, Cary L Siegel
PURPOSE: The purpose of the study is to evaluate the utility of apparent diffusion coefficient (ADC), chemical shift signal intensity index (SII), and contrast enhancement in distinguishing between benign lesions and renal cell carcinoma (RCC) and between subtypes of renal lesions. METHODS: This retrospective study included 98 renal lesions (≤ 3 cm) on MRI with correlative surgical pathology. Scanner field strength, lesion location, and size were recorded. Two readers blinded to surgical pathology independently measured ADC ratio (ADC lesion/ADC non-lesion kidney), SII, and absolute/relative enhancement in the corticomedullary and nephrographic phases of contrast...
April 24, 2018: Abdominal Radiology
Kiran Kumar Vupparaboina, Kunal K Dansingani, Abhilash Goud, Mohammed Abdul Rasheed, Fayez Jawed, Soumya Jana, Ashutosh Richhariya, Bailey K Freund, Jay Chhablani
Conventionally rendered optical coherence tomography (OCT) images of the posterior segment contain shadows which influence the visualization of deep structures such as the choroid. The purpose of this study was to determine whether OCT shadow compensation (SC) alters the appearance of the choroid and the apparent choroidal vascularity index (CVI), an OCT-derived estimated ratio of luminal to total choroidal volume. All scans were shadow compensated using a previously published algorithm, binarized using a novel validated algorithm and extracted binarized choroid to estimate CVI...
April 24, 2018: Scientific Reports
Samuel Anim-Sampong, Lawrence Arthur, Josephine Abena Nkansah, Benard Ohene Botwe
PURPOSE: To investigate and establish reasons for the smaller but increasing population of female radiographers in Ghana, and to evaluate the motivating and demotivating contributory factors associated with women's choice of the profession. METHODS: A descriptive quantitative survey design and a purposive sampling technique were used to recruit participants from hospitals, clinics, and private imaging centers in Ghana. Forty registered female radiographers were invited to participate in the survey, and 30 participants completed and returned the questionnaires...
March 2018: Radiologic Technology
X X Liang, L D Liang, Y Y Zhang, J B Gao, Y G Zhang, X Liu, Q Chi
Objective: To quantitatively evaluate the quality of advanced modeled iterative reconstruction (ADMIRE) combined with 70 kVp and linear blending images in low dose dual energy (70 kVp/sn150 kVp) pulmonary angiography. Methods: A total of 74 cases with normal BMI underwent dual-source CT dual-energy pulmonary angiography with small amount of contrast medium (30 ml) from 2015 to 2017 from the First Affiliated Hospital of Zhengzhou University were randomly assigned to protocol Ⅰ(100 kVp/sn140 kVp) or protocol Ⅱ(70 kVp/sn150 kVp)...
April 3, 2018: Zhonghua Yi Xue za Zhi [Chinese medical journal]
Jean-Philippe Tetienne, David A Broadway, Scott E Lillie, Nikolai Dontschuk, Tokuyuki Teraji, Liam T Hall, Alastair Stacey, David A Simpson, Lloyd C L Hollenberg
Magnetic imaging with ensembles of nitrogen-vacancy (NV) centres in diamond is a recently developed technique that allows for quantitative vector field mapping. Here we uncover a source of artefacts in the measured magnetic field in situations where the magnetic sample is placed in close proximity (a few tens of nm) to the NV sensing layer. Using magnetic nanoparticles as a test sample, we find that the measured field deviates significantly from the calculated field, in shape, amplitude and even in sign. By modelling the full measurement process, we show that these discrepancies are caused by the limited measurement range of NV sensors combined with the finite spatial resolution of the optical readout...
April 23, 2018: Sensors
Junfeng Wu, Fang Dai, Gang Hu, Xuanqin Mou
Excessive radiation exposure in computed tomography (CT) scans increases the chance of developing cancer and has become a major clinical concern. Recently, statistical iterative reconstruction (SIR) with l0-norm dictionary learning regularization has been developed to reconstruct CT images from the low dose and few-view dataset in order to reduce radiation dose. Nonetheless, the sparse regularization term adopted in this approach is l0-norm, which cannot guarantee the global convergence of the proposed algorithm...
April 18, 2018: Journal of X-ray Science and Technology
Enrico R Fantoni, Anastasia Chalkidou, John T O' Brien, Gill Farrar, Alexander Hammers
BACKGROUND: Amyloid PET (aPET) imaging could improve patient outcomes in clinical practice, but the extent of impact needs quantification. OBJECTIVE: To provide an aggregated quantitative analysis of the value added by aPET in cognitively impaired subjects. METHODS: Systematic literature searches were performed in Embase and Medline until January 2017. 1,531 cases over 12 studies were included (1,142 cases over seven studies in the primary analysis where aPET was the key biomarker; the remaining cases included as defined groups in the secondary analysis)...
April 16, 2018: Journal of Alzheimer's Disease: JAD
Elena Makovac, Laura Serra, Carlotta Di Domenico, Camillo Marra, Carlo Caltagirone, Mara Cercignani, Marco Bozzali
Patients with amnestic mild cognitive impairment (aMCI) have higher probability to develop Alzheimer's disease (AD) than elderly controls. The detection of subtle changes in brain structure associated with disease progression and the development of tools to identify patients at high risk for dementia in a short time is crucial. Here, we used probabilistic white matter (WM) tractography to explore microstructural alterations within the main association, limbic, and commissural pathways in aMCI patients who converted to AD after 1 year follow-up (MCIconverters) and those who remained stable (MCIstable)...
April 16, 2018: Journal of Alzheimer's Disease: JAD
Iulia Grosu, Flaviu Bob, Ioan Sporea, Alina Popescu, Roxana Şirli, Adalbert Schiller
OBJECTIVES: Point shear wave elastography is a quantitative ultrasound-based imaging method used in the assessment of renal disease. Among point shear wave elastographic options, 2 techniques have been studied considerably: Virtual Touch quantification (VTQ; Siemens AG, Erlangen, Germany) and ElastPQ (EPQ; Philips Healthcare, Bothell, WA). Both rely on the tissue response to an acoustic beam generated by the ultrasound transducer. The data on renal VTQ are more extensive, whereas EPQ has been used less thus far in the assessment of the kidneys...
April 24, 2018: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
Marie Lémery Magnin, Victor Fitoussi, Nathalie Siauve, Laetitia Pidial, Daniel Balvay, Gwennhael Autret, Charles André Cuenod, Olivier Clément, Laurent Julien Salomon
PURPOSE: To evaluate placental function and perfusion in a rat model of preeclampsia infused with L-nitro-arginine methyl ester (L-NAME) by dynamic contrast-enhanced (DCE) MRI using gadolinium chelates. METHODS: Pregnant female Sprague-Dawley rats were fitted on embryonic day 16 (E16) with subcutaneous osmotic minipumps loaded to deliver, continuously, L-NAME (50 mg/day per rat; case group) or saline solution (control group). DCE MRI was performed on E19 using gadolinium chelates and a 4...
April 24, 2018: Fetal Diagnosis and Therapy
Sun Zheng, Zheng Lan
Intravascular photoacoustic (IVPA) imaging can discriminate between normal arterial tissues and atheromatous plaques in images, particularly images of lipid-rich plaques with high spatial resolution and optical contrast. However, conventional IVPA only recovers the deposited optical energy that is the product of the tissue optical absorption coefficient and local optical fluence. Herein, a one-step model-based method for single-wavelength IVPA imaging system is proposed. The proposed method directly reconstructs the optical absorption coefficient from the boundary measurement of acoustic pressure...
April 21, 2018: Computers in Biology and Medicine
Dalong Ni, Dawei Jiang, Hyung-Jun Im, Hector F Valdovinos, Bo Yu, Shreya Goel, Todd E Barnhart, Peng Huang, Weibo Cai
Radiolabeled nanoprobes for positron emission tomography (PET) imaging has received special attention over the past decade, allowing for sensitive, non-invasive, and quantitative detection of different diseases. The rapidly renal clearable nanomaterials normally suffer from a low accumulation in the tumor through the enhanced permeability and retention (EPR) effect due to the rapidly reduced concentration in the blood circulation after renal clearance. It is highly important to design radiolabeled nanomaterials which can meet the balance between the rapid renal clearance and strong EPR effect within a suitable timescale...
April 12, 2018: Biomaterials
Lee H Schwamm, Ona Wu, Shlee S Song, Lawrence L Latour, Andria L Ford, Amie W Hsia, Alona Muzikansky, Rebecca A Betensky, Albert J Yoo, Michael H Lev, Gregoire Boulouis, Arne Lauer, Pedro Cougo, William A Copen, Gordon J Harris, Steven Warach
OBJECTIVE: Most acute ischemic stroke (AIS) patients with unwitnessed symptom onset are ineligible for intravenous thrombolysis due to timing alone. Lesion evolution on FLAIR MRI correlates with stroke duration, and quantitative mismatch of diffusion-weighted MRI (DWI) with FLAIR (qDFM) might indicate stroke duration within guideline-recommended thrombolysis. We tested if intravenous thrombolysis ≤4.5 h from time of symptom discovery is safe in patients with qDFM in an open-label, phase 2a, prospective study (NCT01282242)...
April 24, 2018: Annals of Neurology
Thorsten Derlin, Catharina Kelting, Katja Hueper, Desiree Weiberg, Katrin Meyer, Karen M Olsson, James T Thackeray, Tobias Welte, Frank M Bengel, Marius M Hoeper
BACKGROUND: We evaluated the feasibility of perfusion SPECT/CT for providing quantitative data for estimation of perfusion defect extent in chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: Thirty patients with CTEPH underwent Tc-human serum albumin lung perfusion SPECT/CT. Perfusion defects were quantified using 3 different methods: (1) visual, semiquantitative scoring of perfusion defect extent in each lung segment, (2) threshold-based segmentation of perfused lung volumes, and (3) threshold-based segmentation of perfused lung volumes divided by segmented lung volumes at CT (perfusion index)...
April 23, 2018: Clinical Nuclear Medicine
T Elsasser, K Miska, S Kahl, R Fetterer, A Martínez
Intracellular generation of nitric oxide (NO) and superoxide anion (SOA) can result in the formation of 3'-nitrotyrosine proteins (NTp). Nitrated proteins usually are associated with significant perturbation in protein function, apoptosis, autophagy and cell death. We undertook the present study to establish the temporal dynamics of NTp generation in cytokeratin-18-positive epithelial cells (ETCs) of broiler chickens in response to infection with Eimeria acervulina. Duodenal tissue was harvested from non-infected (NOI) and infected (INF) broilers on days (d) 1, 3, 6, 7 and 10 post-infection (PI) and fixed, embedded, and sectioned for quantitative image analysis, immunohistochemistry with antibodies specific to NTp and the SOA-generating enzyme xanthine oxidase (XO)...
April 24, 2018: Journal of Animal Science
Olli Nykänen, Lassi Rieppo, Juha Töyräs, Ville Kolehmainen, Simo Saarakkala, Karin Shmueli, Mikko J Nissi
PURPOSE: We investigated the feasibility of quantitative susceptibility mapping (QSM) for assessing degradation of articular cartilage by measuring ex vivo bovine cartilage samples subjected to different degradative treatments. Specimens were scanned at several orientations to study if degradation affects the susceptibility anisotropy. T2*-mapping, histological stainings, and polarized light microscopy were used as reference methods. Additionally, simulations of susceptibility in layered geometry were performed...
April 24, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Congbo Cai, Chao Wang, Yiqing Zeng, Shuhui Cai, Dong Liang, Yawen Wu, Zhong Chen, Xinghao Ding, Jianhui Zhong
PURPOSE: An end-to-end deep convolutional neural network (CNN) based on deep residual network (ResNet) was proposed to efficiently reconstruct reliable T2 mapping from single-shot overlapping-echo detachment (OLED) planar imaging. METHODS: The training dataset was obtained from simulations that were carried out on SPROM (Simulation with PRoduct Operator Matrix) software developed by our group. The relationship between the original OLED image containing two echo signals and the corresponding T2 mapping was learned by ResNet training...
April 24, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Chunyang Chen, Liuqing Zhou, Wei Liu, Wei-Sheng Liu
Coumarinocoumarin, one of the coumarin derivatives, is easy to synthesize and have rich modification sites. The large conju-gate plane of coumarinocoumarin make it has more excellent optical property than conventional coumarin, for example, the two-photon fluorescence property. So, the coumarinocoumarin-based probe (CCy) has been designed and synthesized, which is the first lysosomal targeting fluorescent biosensor for cysteine. This probe was prepared by a 3-step procedure as a latent fluorescence probe to achieve high sensitivity and fluorescence turn-on response toward cysteine (Cys) over homocys-teine (Hcy), glutathione (GSH) and other various natural amino acids under physiological conditions...
April 24, 2018: Analytical Chemistry
Huangxuan Zhao, Guangsong Wang, Riqiang Lin, Xiaojing Gong, Liang Song, Tan Li, Wenjia Wang, Kunya Zhang, Xiuqing Qian, Haixia Zhang, Lin Li, Zhicheng Liu, Chengbo Liu
For the diagnosis and evaluation of ophthalmic diseases, imaging and quantitative characterization of vasculature in the iris are very important. The recently developed photoacoustic imaging, which is ultrasensitive in imaging endogenous hemoglobin molecules, provides a highly efficient label-free method for imaging blood vasculature in the iris. However, the development of advanced vascular quantification algorithms is still needed to enable accurate characterization of the underlying vasculature. We have developed a vascular information quantification algorithm by adopting a three-dimensional (3-D) Hessian matrix and applied for processing iris vasculature images obtained with a custom-built optical-resolution photoacoustic imaging system (OR-PAM)...
April 2018: Journal of Biomedical Optics
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"