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Sample records for renal dynamic imaging

  1. Dynamic noninvasive monitoring of renal function in vivo by fluorescence lifetime imaging

    NASA Astrophysics Data System (ADS)

    Goiffon, Reece J.; Akers, Walter J.; Berezin, Mikhail Y.; Lee, Hyeran; Achilefu, Samuel

    2009-03-01

    Kidneys normally filter the blood of excess salts and metabolic products, such as urea, while retaining plasma proteins. In diseases such as multiple myeloma and diabetes mellitus, the renal function is compromised and protein escapes into the urine. In this study, we present the use of fluorescence lifetime imaging (FLI) to image excess serum protein in urine (proteinuria). The near-infrared fluorescent dye LS-288 has distinct lifetimes when bound to protein versus free in solution, providing contrast between the protein-rich viscera and the mostly protein-free bladder. FLI with LS-288 in mice revealed that fluorescence lifetime (FLT) differences in the bladder relative to surrounding tissues was due to the fractional contributions of the bound and unbound dye molecules. The FLT of LS-288 decreased in the case of proteinuria while fluorescence intensity was unchanged. The results show that FLI can be useful for the dynamic imaging of protein-losing nephropathy due to diabetes mellitus and other renal diseases and suggest the potential use of the FLI to distinguish tumors from fluid-filled cysts in the body.

  2. Renal imaging techniques.

    PubMed

    Hierholzer, K; Hierholzer, J

    1997-01-01

    The ancient approach to obtain an image of the kidneys (and other internal organs) was 'section-inspection-imaging' by drawing, painting, sculpturing, and modelling. The present study follows chronologically the development and use of sectioning techniques from ancient (often forbidden) methods to modern microdissection and maceration of silicone-rubber-injected tubules. Inspection evolved from the use of the naked eye to magnifying lenses, microscopes and finally electron microscopy. Pertinent examples such as the description of the kidneys as the site of urine formation, the visualization of loop structures in the renal medulla and the imaging of tight junction strands are discussed. Inspection or visualization of renal structure and function has been revolutionized by modern noninvasive techniques, such as X-ray imaging, imaging by radioisotopes, ultrasound, computer tomography and nuclear magnetic resonance. Pertinent examples are given demonstrating the potency of the various techniques. The contribution of computerized data evaluation is discussed. The development of micropuncture and microperfusion techniques has opened the field for direct imaging not only of renal (sub)structural details but also of functional parameters such as transtubular reabsorption rates, single glomerular capillary filtration and conductance of the paracellular pathway. We focus particularly on techniques specifically designed to visualize renal hemodynamic and transport parameters.

  3. [Imaging renal cell carcinoma].

    PubMed

    Bazan, F; Busto, M

    2014-01-01

    Renal cell carcinoma is the eighth most common malignancy in adults and the most common malignancy in the kidney. It is thus a very common disease for radiologists. This review aims to provide a general overview of the imaging techniques used to diagnose, characterize, and help plan the treatment of renal cell carcinoma as well as to review basic aspects related to staging, imaging-guided percutaneous treatment, and follow-up in the most common clinical scenarios. Copyright © 2012 SERAM. Published by Elsevier Espana. All rights reserved.

  4. Imaging of Renal Medullary Carcinoma

    PubMed Central

    Faiella, Eliodoro; Santucci, Domiziana; Mallio, Carlo Augusto; Nezzo, Marco; Quattrocchi, Carlo Cosimo; Beomonte Zobel, Bruno; Grasso, Rosario Francesco

    2017-01-01

    Renal medullary carcinoma (RMC) is a rare, highly aggressive tumor recognized as an independent pathological entity. African-descent adolescents and young adults with sickle cell hemoglobinopathy are the most affected groups. This rare subtype of renal cell carcinoma has its own morphogenetic and pathological characteristics. The major clinical manifestations include gross hematuria, abdominal or flank pain, and weight loss. The prognosis is very poor, with 95% of cases diagnosed at an advanced stage of the disease. In this review, we summarize the morphologic and dynamic characteristics of RMC under various imaging modalities such as ultrasound, computed tomography, and magnetic resonance. Differential diagnosis and management strategies are also discussed. PMID:28405543

  5. Determination of single-kidney glomerular filtration rate (GFR) with CT urography versus renal dynamic imaging Gates method.

    PubMed

    You, Shan; Ma, XianWu; Zhang, ChangZhu; Li, Qiang; Shi, WenWei; Zhang, Jing; Yuan, XiaoDong

    2017-10-02

    To present a single-kidney CT-GFR measurement and compare it with the renal dynamic imaging Gates-GFR. Thirty-six patients with hydronephrosis referred for CT urography and 99mTc-DTPA renal dynamic imaging were prospectively included. Informed consent was obtained from all patients. The CT urography protocol included non-contrast, nephrographic, and excretory phase imaging. The total CT-GFR was calculated by dividing the CT number increments of the total urinary system between the nephrographic and excretory phase by the products of iodine concentration in the aorta and the elapsed time, then multiplied by (1- Haematocrit). The total CT-GFR was then split into single-kidney CT-GFR by a left and right kidney proportionality factor. The results were compared with single-kidney Gates-GFR by using paired t-test, correlation analysis, and Bland-Altman plots. Paired difference between single-kidney CT-GFR (45.02 ± 13.91) and single-kidney Gates-GFR (51.21 ± 14.76) was 6.19 ± 5.63 ml/min, p<0.001, demonstrating 12.1% systematic underestimation with ±11.03 ml/min (±21.5%) measurement deviation. A good correlation was revealed between both measurements (r=0.87, p<0.001). The proposed single-kidney CT-GFR correlates and agrees well with the reference standard despite a systematic underestimation, therefore it could be a one-stop-shop for evaluating urinary tract morphology and split renal function. • A new CT method can assess split renal function • Only using images from CT urography and the value of haematocrit • A one-stop-shop CT technique without additional radiation dose.

  6. Tumor Vascularity in Renal Masses: Correlation of Arterial Spin-Labeled and Dynamic Contrast Enhanced MR Imaging Assessments

    PubMed Central

    Zhang, Yue; Kapur, Payal; Yuan, Qing; Xi, Yin; Carvo, Ingrid; Signoretti, Sabina; Dimitrov, Ivan; Cadeddu, Jeffrey A.; Margulis, Vitaly; Muradyan, Naira; Brugarolas, James; Madhuranthakam, Ananth J.; Pedrosa, Ivan

    2015-01-01

    Objective To investigate potential correlations between perfusion by arterial spin-labeled (ASL) magnetic resonance imaging (MRI) and dynamic contrast enhanced (DCE) MRI derived quantitative measures of vascularity in renal masses >2 cm and to correlate these with microvessel density (MVD) in clear cell renal cell carcinoma (ccRCC). Methods Informed written consent was obtained from all patients before imaging in this HIPAA-compliant, IRB-approved, prospective study. 36 consecutive patients scheduled for surgery of a known renal mass >2 cm underwent 3T ASL and DCE MRI. ASL measures (PASL) of mean, peak, and low perfusion areas within the mass were correlated to DCE-derived Ktrans, Kep, and Ve in the same locations using a region of interest analysis. MRI data were correlated to MVD measures in the same tumor regions in ccRCC. Spearman correlation was used to evaluate the correlation between PASL and DCE-derived measurements, and MVD. P<0.05 was considered statistically significant. Results Histopathologic diagnosis was obtained in 36 patients (25 men; mean age 58 ±12 years). PASL correlated with Ktrans (ρ=0.48, P=0.0091 for the entire tumor and ρ=0.43, P=0.03 for the high flow area, respectively) and Kep (ρ=0.46, P=0.01 for the entire tumor and ρ=0.52, P=0.008 for the high flow area, respectively). PASL (ρ=0.66, P=0.0002), Ktrans (ρ=0.61, P=0.001), and Kep (ρ=0.64, P=0.0006) also correlated with MVD in high and low perfusion areas in ccRCC. Conclusions PASL correlate with the DCE-derived measures of vascular permeability and flow, Ktrans and Kep, in renal masses >2cm in size. Both measures correlate to MVD in clear cell histology. MICROABSTRACT Arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) have been proposed to quantitatively assess vascularity in renal cell carcinoma (RCC). However there are intrinsic differences between these two imaging methods, such as the relative contribution of vascular permeability

  7. Tumor Vascularity in Renal Masses: Correlation of Arterial Spin-Labeled and Dynamic Contrast-Enhanced Magnetic Resonance Imaging Assessments.

    PubMed

    Zhang, Yue; Kapur, Payal; Yuan, Qing; Xi, Yin; Carvo, Ingrid; Signoretti, Sabina; Dimitrov, Ivan; Cadeddu, Jeffrey A; Margulis, Vitaly; Muradyan, Naira; Brugarolas, James; Madhuranthakam, Ananth J; Pedrosa, Ivan

    2016-02-01

    Arterial spin-labeled (ASL) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) have been proposed to quantitatively assess vascularity in renal cell carcinoma (RCC). However, there are intrinsic differences between these 2 imaging methods, such as the relative contribution of vascular permeability and blood flow to signal intensity for DCE MRI. We found a correlation between ASL perfusion and the DCE-derived volume transfer constant and rate constant parameters in renal masses > 2 cm in size and these measures correlated with microvessel density in clear cell RCC. The objective of this study was to investigate potential correlations between perfusion using arterial spin-labeled (ASL) magnetic resonance imaging (MRI) and dynamic contrast-enhanced (DCE) MRI-derived quantitative measures of vascularity in renal masses > 2 cm and to correlate these with microvessel density (MVD) in clear cell renal cell carcinoma (ccRCC). Informed written consent was obtained from all patients before imaging in this Health Insurance Portability and Accountability Act-compliant, institutional review board-approved, prospective study. Thirty-six consecutive patients scheduled for surgery of a known renal mass > 2 cm underwent 3T ASL and DCE MRI. ASL perfusion measures (PASL) of mean, peak, and low perfusion areas within the mass were correlated to DCE-derived volume transfer constant (K(trans)), rate constant (Kep), and fractional volume of the extravascular extracellular space (Ve) in the same locations using a region of interest analysis. MRI data were correlated to MVD measures in the same tumor regions in ccRCC. Spearman correlation was used to evaluate the correlation between PASL and DCE-derived measurements, and MVD. P < .05 was considered statistically significant. Histopathologic diagnosis was obtained in 36 patients (25 men; mean age 58 ± 12 years). PASL correlated with K(trans) (ρ = 0.48 and P = .0091 for the entire tumor and ρ = 0.43 and P = .03 for the

  8. Dynamic Contrast-enhanced MR Imaging in Renal Cell Carcinoma: Reproducibility of Histogram Analysis on Pharmacokinetic Parameters

    PubMed Central

    Wang, Hai-yi; Su, Zi-hua; Xu, Xiao; Sun, Zhi-peng; Duan, Fei-xue; Song, Yuan-yuan; Li, Lu; Wang, Ying-wei; Ma, Xin; Guo, Ai-tao; Ma, Lin; Ye, Hui-yi

    2016-01-01

    Pharmacokinetic parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) have been increasingly used to evaluate the permeability of tumor vessel. Histogram metrics are a recognized promising method of quantitative MR imaging that has been recently introduced in analysis of DCE-MRI pharmacokinetic parameters in oncology due to tumor heterogeneity. In this study, 21 patients with renal cell carcinoma (RCC) underwent paired DCE-MRI studies on a 3.0 T MR system. Extended Tofts model and population-based arterial input function were used to calculate kinetic parameters of RCC tumors. Mean value and histogram metrics (Mode, Skewness and Kurtosis) of each pharmacokinetic parameter were generated automatically using ImageJ software. Intra- and inter-observer reproducibility and scan–rescan reproducibility were evaluated using intra-class correlation coefficients (ICCs) and coefficient of variation (CoV). Our results demonstrated that the histogram method (Mode, Skewness and Kurtosis) was not superior to the conventional Mean value method in reproducibility evaluation on DCE-MRI pharmacokinetic parameters (K trans & Ve) in renal cell carcinoma, especially for Skewness and Kurtosis which showed lower intra-, inter-observer and scan-rescan reproducibility than Mean value. Our findings suggest that additional studies are necessary before wide incorporation of histogram metrics in quantitative analysis of DCE-MRI pharmacokinetic parameters. PMID:27380733

  9. Renal arteries (image)

    MedlinePlus

    A renal angiogram is a test used to examine the blood vessels of the kidneys. The test is performed ... main vessel of the pelvis, up to the renal artery that leads into the kidney. Contrast medium ...

  10. Imaging of Solid Renal Masses.

    PubMed

    Kay, Fernando U; Pedrosa, Ivan

    2017-03-01

    Detection of solid renal masses has increased, although it has not resulted in significant mortality reduction from renal cell carcinoma. Efforts for improved lesion characterization have been pursued and incorporated in management algorithms, in order to distinguish clinically significant tumors from favorable or benign conditions. Concurrently, imaging methods have produced evidence supporting their role as useful tools not only in lesion detection but also characterization. In addition, newer modalities, such as contrast-enhanced ultrasonography, and advanced applications of MR imaging, are being investigated. This article reviews the current role of different imaging methods in the characterization of solid renal masses.

  11. Scintigraphic imaging in renal infections.

    PubMed

    Rossleigh, M A

    2009-02-01

    The scintigraphic imaging modality of choice in the evaluation of renal infections is renal cortical scintigraphy utilizing [(99m)Tc]dimercaptosuccinic acid (DMSA). This technique is able to demonstrate upper tract involvement with infection and to assess for the presence of renal cortical scarring following a urinary tract infection (UTI). There are recent publications advocating its use to determine which patients need to proceed to further investigation with cystography. It is also being utilized in the evaluation of different treatment regimes used in patients with UTI. Fluorodeoxyglucose (FDG)-PET and leukocyte scanning have only a minor role in the diagnosis of renal infection. Their main application is in the diagnosis of renal cyst infections in patients with polycystic renal disease.

  12. Multiphoton imaging of renal regulatory mechanisms.

    PubMed

    Peti-Peterdi, János; Toma, Ildikó; Sipos, Arnold; Vargas, Sarah L

    2009-04-01

    Most physiological functions of the kidneys, including the clearance of metabolic waste products, maintenance of body fluid, electrolyte homeostasis, and blood pressure, are achieved by complex interactions between multiple renal cell types and previously inaccessible structures in many organ parts that have been difficult to study. Multiphoton fluorescence microscopy offers a state-of-the-art imaging technique for deep optical sectioning of living tissues and organs with minimal deleterious effects. Dynamic regulatory processes and multiple functions in the intact kidney can be quantitatively visualized in real time, noninvasively, and with submicron resolution. This article reviews innovative multiphoton imaging technologies and their applications that provided the most complex, immediate, and dynamic portrayal of renal function-clearly depicting as well as analyzing the components and mechanisms involved in renal (patho)physiology.

  13. p38 MAPK inhibitors ameliorate target organ damage in hypertension: Part 2. Improved renal function as assessed by dynamic contrast-enhanced magnetic resonance imaging.

    PubMed

    Lenhard, Stephen C; Nerurkar, Sandhya S; Schaeffer, Thomas R; Mirabile, Rosanna C; Boyce, Rogely W; Adams, David F; Jucker, Beat M; Willette, Robert N

    2003-12-01

    Recent evidence suggests p38 mitogen-activated protein kinase (MAPK) signal transduction plays an important role in the pathogenesis of progressive renal disease. Using dynamic contrast enhanced magnetic resonance imaging (MRI), we evaluated chronic treatment with a p38 MAPK inhibitor, trans-1-(4-hydroxycyclohexyl)-4-(4-fluorophenyl-methoxypyridimidin-4-yl)imidazole (SB-239063), on renal function in a hypertension model of progressing renal dysfunction. Spontaneously hypertensive-stroke prone rats were placed on a high salt/fat diet (SFD) or maintained on normal chow diet (ND). SFD animals with albuminuria at 4 to 8 weeks (> or =10 mg/day inclusion criteria), were randomized into p38 MAPK inhibitor treatment (SB-239063, 1200 ppm in diet) or vehicle groups. The progression of blood pressure and albuminuria during the treatment period (approximately 6 weeks) was decreased by 12 and 60%, respectively, in the SFD + SB-239063 versus SFD control group. Renal perfusion and filtration were assessed by in vivo MRI at the end of the study. Relative cortical perfusion was increased in the SFD + SB-239063 group compared with the SFD control group as reflected by a 29% decrease in time to peak of contrast agent in the cortex. Additionally, the regional renal glomerular filtration rate index (Kcl) was increased by 39% in the SFD + SB-239063 versus SFD control group and was normalized to the ND control group. Greater functional heterogeneity was observed in the SFD control versus SFD + SB-239063 or ND control group. All alterations of renal function were supported by histopathological findings. In conclusion, chronic treatment with a p38 MAPK inhibitor, SB-239063, attenuates functional and structural renal degeneration in a hypertensive model of established renal dysfunction.

  14. Integrated imaging of neonatal renal masses.

    PubMed

    Kirks, D R; Rosenberg, E R; Johnson, D G; King, L R

    1985-01-01

    Thirty-three neonatal renal masses were evaluated during a 2-year interval. The final diagnoses in these 33 patients were hydronephrosis [14], multicystic dysplastic kidney [10], renal vein thrombosis [3], obstructed upper pole duplication [2], polycystic kidney disease [2], nephroblastomatosis [1], and mesoblastic nephroma [1]. We recommend an integrated imaging approach that utilizes sonography to clarify anatomy and renal scintigraphy or excretory urography to determine renal function.

  15. Renal amyloidosis. Evaluation by gallium imaging

    SciTech Connect

    Lee, V.W.; Skinner, M.; Cohen, A.S.; Ngai, S.; Peng, T.T.

    1986-09-01

    A study has been performed to evaluate the efficacy of gallium imaging in the detection of renal amyloidosis. Ten of the 11 patients who had biopsy-proven renal amyloidosis demonstrated marked uptake in both kidneys. One patient revealed moderate gallium uptake in his kidneys. None of the patients had underlying renal or extrarenal pathology other than amyloidosis, which could account for renal gallium uptake (renal infection, neoplasm, hepatic failure or frequent blood transfusions). Four patients also had extrarenal foci of abnormal gallium uptake, suggesting other sites of amyloid deposits. Our data strongly suggest that gallium imaging has a high sensitivity for detection of renal amyloidosis. Its specificity is enhanced significantly by careful review of the clinical history to exclude other known causes of renal gallium uptake. Potentially, gallium imaging may be used to monitor the progress of patients under experimental therapy.

  16. Pitfalls and Limitations of Radionuclide Renal Imaging in Adults.

    PubMed

    Keramida, Georgia; James, Jacqueline M; Prescott, Mary C; Peters, Adrien Michael

    2015-09-01

    To understand pitfalls and limitations in adult renography, it is necessary to understand firstly the physiology of the kidney, especially the magnitude and control of renal blood flow, glomerular filtration rate and tubular fluid flow rate, and secondly the pharmacokinetics and renal handling of the three most often used tracers, Tc-99m-mercaptoacetyltriglycine (MAG3), Tc-99m-diethylene triamine pentaacetic acid (DTPA) and Tc-99m-dimercaptosuccinic acid (DMSA). The kidneys may be imaged dynamically with Tc-99m-MAG3 or Tc-99m-DTPA, with or without diuretic challenge, or by static imaging with Tc-99m-DMSA. Protocols are different according to whether the kidney is native or transplanted. Quantitative analysis of dynamic data includes measurement of renal vascularity (important for the transplanted kidney), absolute tracer clearance rates, differential renal function (DRF) and response to diuretic challenge. Static image reveals functional renal parenchymal damage, both focal and global, is useful in the clinical management of obstructive uropathy, renal stone disease and hypertension (under angiotensin converting enzyme inhibition), and is the preferred technique for determining DRF. Diagnosis based on morphological appearances is important in transplant management. Even though nuclear medicine is now in the era of hybrid imaging, renal imaging remains an important subspecialty in nuclear medicine and requires a sound basing in applied physiology, the classical supporting discipline of nuclear medicine.

  17. Imaging of haemodialysis: renal and extrarenal findings.

    PubMed

    Degrassi, Ferruccio; Quaia, Emilio; Martingano, Paola; Cavallaro, Marco; Cova, Maria Assunta

    2015-06-01

    Electrolyte alterations and extra-renal disorders are quite frequent in patients undergoing haemodialysis or peritoneal dialysis. The native kidneys may be the site of important pathologies in patients undergoing dialysis, especially in the form of acquired renal cystic disease with frequent malignant transformation. Renal neoplasms represents an important complication of haemodialysis-associated acquired cystic kidney disease and imaging surveillance is suggested. Extra-renal complications include renal osteodistrophy, brown tumours, and thoracic and cardiovascular complications. Other important fields in which imaging techniques may provide important informations are arteriovenous fistula and graft complications. Teaching points • Renal neoplasms represent a dreaded complication of haemodialysis.• In renal osteodystrophy bone resorption typically manifests along the middle phalanges.• Brown tumours are well-defined lytic lesions radiographically, possibly causing bone expansion.• Vascular calcifications are very common in patients undergoing haemodialysis.• Principal complications of the AV fistula consist of thrombosis, aneurysms and pseudoaneurysms.

  18. Multimodality Imaging Findings of a Renal Aspergilloma

    PubMed Central

    Bulakçı, Mesut; Kartal, Merve Gülbiz; Çelenk, Erhan; Tunçer, Sena; Kılıçaslan, Işın

    2016-01-01

    Background Renal aspergillosis is a rare infection that usually occurs in persons with a predisposition for this condition. Its differential diagnosis includes primary and metastatic renal malignancies, pyelonephritis and secondary abscess formation, granulomatous disorders, and renal infarction. We aim to stress the role of multimodality imaging and percutaneous biopsy in the diagnosis of this condition. Case Report We present diffusion weighted imaging (DWI) and positron emission tomography-computed tomography (PET-CT) findings in addition to conventional imaging modalities in a 55-year-old man with secondary renal aspergilloma. Conclusion Radiological imaging methods are an integral part of diagnostic workup for renal aspergillosis. A definitive diagnosis is made by histopathological and/or microbiological examination of the material obtained via percutaneous biopsy under guidance of imaging methods. PMID:27994929

  19. Multimodality imaging of renal inflammatory lesions

    PubMed Central

    Das, Chandan J; Ahmad, Zohra; Sharma, Sanjay; Gupta, Arun K

    2014-01-01

    Spectrum of acute renal infections includes acute pyelonephritis, renal and perirenal abscesses, pyonephrosis, emphysematous pyelonephritis and emphysematous cystitis. The chronic renal infections that we routinely encounter encompass chronic pyelonephritis, xanthogranulomatous pyelonephritis, and eosinophilic cystitis. Patients with diabetes, malignancy and leukaemia are frequently immunocompromised and more prone to fungal infections viz. angioinvasive aspergillus, candida and mucor. Tuberculosis and parasitic infestation of the kidney is common in tropical countries. Imaging is not routinely indicated in uncomplicated renal infections as clinical findings and laboratory data are generally sufficient for making a diagnosis. However, imaging plays a crucial role under specific situations like immunocompromised patients, treatment non-responders, equivocal clinical diagnosis, congenital anomaly evaluation, transplant imaging and for evaluating extent of disease. We aim to review in this article the varied imaging spectrum of renal inflammatory lesions. PMID:25431641

  20. Multimodality imaging of renal inflammatory lesions.

    PubMed

    Das, Chandan J; Ahmad, Zohra; Sharma, Sanjay; Gupta, Arun K

    2014-11-28

    Spectrum of acute renal infections includes acute pyelonephritis, renal and perirenal abscesses, pyonephrosis, emphysematous pyelonephritis and emphysematous cystitis. The chronic renal infections that we routinely encounter encompass chronic pyelonephritis, xanthogranulomatous pyelonephritis, and eosinophilic cystitis. Patients with diabetes, malignancy and leukaemia are frequently immunocompromised and more prone to fungal infections viz. angioinvasive aspergillus, candida and mucor. Tuberculosis and parasitic infestation of the kidney is common in tropical countries. Imaging is not routinely indicated in uncomplicated renal infections as clinical findings and laboratory data are generally sufficient for making a diagnosis. However, imaging plays a crucial role under specific situations like immunocompromised patients, treatment non-responders, equivocal clinical diagnosis, congenital anomaly evaluation, transplant imaging and for evaluating extent of disease. We aim to review in this article the varied imaging spectrum of renal inflammatory lesions.

  1. Imaging in acute renal infection in children

    SciTech Connect

    Sty, J.R.; Wells, R.G.; Starshak, R.J.; Schroeder, B.A.

    1987-03-01

    Infection is the most common disease of the urinary tract in children, and various imaging techniques have been used to verify its presence and location. On retrospective analysis, 50 consecutive children with documented upper urinary tract infection had abnormal findings on renal cortical scintigraphy with 99mTc-glucoheptonate. The infection involved the renal poles only in 38 and the poles plus other renal cortical areas in eight. Four had abnormalities that spared the poles. Renal sonograms were abnormal in 32 of 50 children. Excretory urograms were abnormal in six of 23 children in whom they were obtained. Vesicoureteral reflux was found in 34 of 40 children in whom voiding cystourethrography was performed. These data show the high sensitivity of renal cortical scintigraphy with 99mTc-glucoheptonate in documenting upper urinary tract infection. The location of the abnormalities detected suggests that renal infections spread via an ascending mode and implies that intrarenal reflux is a major contributing factor.

  2. Infrared spectroscopic imaging of renal tumor tissue

    NASA Astrophysics Data System (ADS)

    Šablinskas, Valdas; Urbonienė, Vidita; Ceponkus, Justinas; Laurinavicius, Arvydas; Dasevicius, Darius; Jankevičius, Feliksas; Hendrixson, Vaiva; Koch, Edmund; Steiner, Gerald

    2011-09-01

    Fourier transform infrared (FTIR) spectroscopic imaging has been used to probe the biochemical composition of human renal tumor tissue and adjacent normal tissue. Freshly resected renal tumor tissue from surgery was prepared as a thin cryosection and examined by FTIR spectroscopic imaging. Tissue types could be discriminated by utilizing a combination of fuzzy k-means cluster analysis and a supervised classification algorithm based on a linear discriminant analysis. The spectral classification is compared and contrasted with the histological stained image. It is further shown that renal tumor cells have spread in adjacent normal tissue. This study demonstrates that FTIR spectroscopic imaging can potentially serve as a fast and objective approach for discrimination of renal tumor tissue from normal tissue and even in the detection of tumor infiltration in adjacent tissue.

  3. Renal relevant radiology: renal functional magnetic resonance imaging.

    PubMed

    Ebrahimi, Behzad; Textor, Stephen C; Lerman, Lilach O

    2014-02-01

    Because of its noninvasive nature and provision of quantitative measures of a wide variety of physiologic parameters, functional magnetic resonance imaging (MRI) shows great potential for research and clinical applications. Over the past decade, application of functional MRI extended beyond detection of cerebral activity, and techniques for abdominal functional MRI evolved. Assessment of renal perfusion, glomerular filtration, interstitial diffusion, and parenchymal oxygenation turned this modality into an essential research and potentially diagnostic tool. Variations in many renal physiologic markers can be detected using functional MRI before morphologic changes become evident in anatomic magnetic resonance images. Moreover, the framework of functional MRI opened a window of opportunity to develop novel pathophysiologic markers. This article reviews applications of some well validated functional MRI techniques, including perfusion, diffusion-weighted imaging, and blood oxygen level-dependent MRI, as well as some emerging new techniques such as magnetic resonance elastography, which might evolve into clinically useful tools.

  4. Image-Guided Adrenal and Renal Biopsy

    PubMed Central

    Sharma, Karun V.; Venkatesan, Aradhana M.; Swerdlow, Daniel; DaSilva, Daniel; Beck, Avi; Jain, Nidhi; Wood, Bradford J.

    2010-01-01

    Image-guided biopsy is a safe and well-established technique that is familiar to most interventional radiologists (IRs). Improvements in image-guidance, biopsy tools and biopsy techniques now routinely allow for safe biopsy of renal and adrenal lesions which traditionally were considered difficult to reach or technically challenging. Image-guided biopsy is used to establish the definitive tissue diagnosis in adrenal mass lesions that can not be fully characterized with imaging or laboratory tests alone. It is also used to establish definitive diagnosis in some cases of renal parenchymal disease and has an expanding role in diagnosis and characterization of renal masses prior to treatment. Although basic principles and techniques for image-guided needle biopsy are similar regardless of organ, this paper will highlight some technical considerations, indications and complications which are unique to the adrenal gland and kidney because of their anatomic location and physiologic features. PMID:20540919

  5. Gallium-68 EDTA PET/CT for Renal Imaging.

    PubMed

    Hofman, Michael S; Hicks, Rodney J

    2016-09-01

    Nuclear medicine renal imaging provides important functional data to assist in the diagnosis and management of patients with a variety of renal disorders. Physiologically stable metal chelates like ethylenediaminetetraacetic acid (EDTA) and diethylenetriamine penta-acetate (DTPA) are excreted by glomerular filtration and have been radiolabelled with a variety of isotopes for imaging glomerular filtration and quantitative assessment of glomerular filtration rate. Gallium-68 ((68)Ga) EDTA PET usage predates Technetium-99m ((99m)Tc) renal imaging, but virtually disappeared with the widespread adoption of gamma camera technology that was not optimal for imaging positron decay. There is now a reemergence of interest in (68)Ga owing to the greater availability of PET technology and use of (68)Ga to label other radiotracers. (68)Ga EDTA can be used a substitute for (99m)Tc DTPA for wide variety of clinical indications. A key advantage of PET for renal imaging over conventional scintigraphy is 3-dimensional dynamic imaging, which is particularly helpful in patients with complex anatomy in whom planar imaging may be nondiagnostic or difficult to interpret owing to overlying structures containing radioactive urine that cannot be differentiated. Other advantages include accurate and absolute (rather than relative) camera-based quantification, superior spatial and temporal resolution and integrated multislice CT providing anatomical correlation. Furthermore, the (68)Ga generator enables on-demand production at low cost, with no additional patient radiation exposure compared with conventional scintigraphy. Over the past decade, we have employed (68)Ga EDTA PET/CT primarily to answer difficult clinical questions in patients in whom other modalities have failed, particularly when it was envisaged that dynamic 3D imaging would be of assistance. We have also used it as a substitute for (99m)Tc DTPA if unavailable owing to supply issues, and have additionally examined the role of

  6. [Diagnostic imaging of peripheral renal vascular disorders].

    PubMed

    Hélénon, O; Correas, J M; Eiss, D; Khairoune, A; Merran, S

    2004-02-01

    Peripheral vascular disorders of the kidney involve the intrarenal branches of the renal vascular tree. It include occlusive (infarction and cortical necrosis) and non-occlusive vascular lesions (acquired arteriovenous fistulas, arteriovenous malformation, false aneurysms and microaneurysms). Initial diagnosis relies on color Doppler US and CT angiography. Angiography plays a therapeutic role. MR imaging provides useful diagnostic information on perfusion disorders especially in patients with renal insufficiency.

  7. Dynamic contrast-enhanced magnetic resonance imaging measurements in renal cell carcinoma: effect of region of interest size and positioning on interobserver and intraobserver variability.

    PubMed

    Braunagel, Margarita; Radler, Elisabeth; Ingrisch, Michael; Staehler, Michael; Schmid-Tannwald, Christine; Rist, Carsten; Nikolaou, Konstantin; Reiser, Maximilian F; Notohamiprodjo, Mike

    2015-01-01

    The purpose of this study was to assess the influence of region of interest (ROI) size and positioning on perfusion and permeability parameters as well as on interobserver and intraobserver variability of dynamic contrast-enhanced (DCE-MRI) of primary renal cell carcinoma (RCC) and metastases. Thirty-nine DCE-MRI examinations of 34 patients with primary RCC and 20 examinations of 9 patients with RCC metastases obtained at 1.5 T were evaluated. Pretreatment and posttreatment analysis with antiangiogenic therapy was performed in 4 patients with primary RCCs and 5 patients with metastases. The ROIs of the whole tumor (wROI), the circular edge (cROI), a user-defined arbitrary small region (sROI), and a semiautomated segmented ROI were independently defined by 2 readers on 1 slice on arterial phase DCE-MRI images or on parametric plasma-flow maps. Analysis with a 2-compartment exchange model provided 4 parameters: plasma flow (FP), plasma volume (vp), permeability-surface product (PS), and extravascular-extracellular volume (ve). Interobserver and intraobserver parameter correlations were calculated using the intraclass correlation coefficient, and within-subject variability were considered on the basis of the coefficient of variation. Differences in measurement values of variable ROI size were assessed with paired t test. Mean values of FP and vp with sROIs were significantly higher than those with wROI, cROI, and semiautomated segmented ROI placement in tumor or metastases. Values of ve showed no significant difference between ROI sizes. The highest interobserver and intraobserver correlation with 0.99/0.98 for metastases and 0.97/0.98 for primary RCCs, respectively, was observed for all parameters when defining wROIs on dynamic images. Perfusion parameters of wROI measurements for FP (dynamic, 0.97; parametric maps, 0.96) and vp (0.95/0.89) showed higher interobserver correlation than did permeability parameters ve (0.64/0.6) and PS (0.79/0.5) in primary RCCs. The w

  8. Changes of renal blood flow after ESWL: assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index.

    PubMed

    Abd Ellah, Mohamed; Kremser, Christian; Pallwein, Leo; Aigner, Friedrich; Schocke, Michael; Peschel, Reinhard; Pedross, Florian; Pinggera, Germar-Michael; Wolf, Christian; Alsharkawy, Mostafa A M; Jaschke, Werner; Frauscher, Ferdinand

    2010-10-01

    The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12h before and 12h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (p<0.001) was found in both treated and untreated kidneys. ASL MR imaging also showed significant changes in both kidneys (p<0.001). Contrast enhanced dynamic MR imaging did not show significant changes in the kidneys. ESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow.

  9. Detecting physiological systems with laser speckle perfusion imaging of the renal cortex.

    PubMed

    Scully, Christopher G; Mitrou, Nicholas; Braam, Branko; Cupples, William A; Chon, Ki H

    2013-06-01

    Laser speckle perfusion imaging (LSPI) has become an increasingly popular technique for monitoring vascular perfusion over a tissue surface. However, few studies have utilized the full range of spatial and temporal information generated by LSPI to monitor spatial properties of physiologically relevant dynamics. In this study, we extend the use of LSPI to analyze renal perfusion dynamics over a spatial surface of ~5 × 7 mm of renal cortex. We identify frequencies related to five physiological systems that induce temporal changes in renal vascular perfusion (cardiac flow pulse, respiratory-induced oscillations, baroreflex components, the myogenic response, and tubuloglomerular feedback) across the imaged surface and compare the results with those obtained from renal blood flow measurements. We find that dynamics supplied from global sources (cardiac, respiration, and baroreflex) present with the same frequency at all locations across the imaged surface, but the local renal autoregulation dynamics can be heterogeneous in their distribution across the surface. Moreover, transfer function analysis with forced blood pressure as the input yields the same information with laser speckle imaging or renal blood flow as the output during control, intrarenal infusion of N(ω)-nitro-L-arginine methyl ester to enhance renal autoregulation, and intrarenal infusion of the rho-kinase inhibitor Y-27632 to inhibit vasomotion. We conclude that LSPI measurements can be used to analyze local as well as global renal perfusion dynamics and to study the properties of physiological systems across the renal cortex.

  10. Diagnostic value of routine bone scintigraphy renal imaging in renal cell carcinoma

    SciTech Connect

    Chancellor, M.B.; Konnak, J.W.; Grossman, H.B.

    1989-05-01

    Technetium-99m-phosphate compounds used in bone scanning are excreted by the kidney, and excellent renal images can be obtained on routine bone scintigrams. The preoperative bone scans of 49 patients who underwent radical nephrectomy for renal cell carcinoma between 1981 and 1985 were reviewed for renal imaging. Ninety-four percent of the patients had abnormal bone scan renal images (82% had focal decreased uptake, and 12% had focal increased uptake). Six percent of the renal images were symmetrical bilaterally. When bone scans are employed in the postoperative follow-up of patients with renal cancer, they can be used to assess the status of the remaining kidney.

  11. Renal compartment segmentation in DCE-MRI images.

    PubMed

    Yang, Xin; Le Minh, Hung; Tim Cheng, Kwang-Ting; Sung, Kyung Hyun; Liu, Wenyu

    2016-08-01

    Renal compartment segmentation from Dynamic Contrast-Enhanced MRI (DCE-MRI) images is an important task for functional kidney evaluation. Despite advancement in segmentation methods, most of them focus on segmenting an entire kidney on CT images, there still lacks effective and automatic solutions for accurate segmentation of internal renal structures (i.e. cortex, medulla and renal pelvis) from DCE-MRI images. In this paper, we introduce a method for renal compartment segmentation which can robustly achieve high segmentation accuracy for a wide range of DCE-MRI data, and meanwhile requires little manual operations and parameter settings. The proposed method consists of five main steps. First, we pre-process the image time series to reduce the motion artifacts caused by the movement of the patients during the scans and enhance the kidney regions. Second, the kidney is segmented as a whole based on the concept of Maximally Stable Temporal Volume (MSTV). The proposed MSTV detects anatomical structures that are homogeneous in the spatial domain and stable in terms of temporal dynamics. MSTV-based kidney segmentation is robust to noises and does not require a training phase. It can well adapt to kidney shape variations caused by renal dysfunction. Third, voxels in the segmented kidney are described by principal components (PCs) to remove temporal redundancy and noises. And then k-means clustering of PCs is applied to separate voxels into multiple clusters. Fourth, the clusters are automatically labeled as cortex, medulla and pelvis based on voxels' geometric locations and intensity distribution. Finally, an iterative refinement method is introduced to further remove noises in each segmented compartment. Experiments on 14 real clinical kidney datasets and 12 synthetic dataset demonstrate that results produced by our method match very well with those segmented manually and the performance of our method is superior to the other five existing methods.

  12. New normal values not related to age and sex, of glomerular filtration rate by (99m)Tc-DTPA renal dynamic imaging, for the evaluation of living kidney graft donors.

    PubMed

    Zhao, Xiuyi; Shao, Yahui; Wang, Yanming; Tian, Jun; Sun, Ben; Ru, Yanhui; Zhang, Aimin; Hao, Junwen

    2012-01-01

    The aim of this study was to investigate the normal values of glomerular filtration rate (GFR) by technetium-99m diaethylene-triamine-pentaacetic acid ((99m)Tc-DTPA) renal dynamic imaging for living kidney graft donors. In a total of 212 candidate donors, GFR was examined using (99m)Tc-DTPA renal dynamic imaging. Donors with GFR≥80mL/(min×1.73m(2)) and as low as with GFR≥70mL/(min×1.73m(2)) but a normal endogenous creatinine clearance rate (CCr) were quantified for living kidney donation. Differences in GFR levels based on sex and age were analyzed using rank correlation coefficient. Out of the 212 candidates, 161 were finally selected as kidney graft donors. The double kidney total GFR between the male and female donor groups, the GFR levels among differently-aged donor groups, and the GFR levels between the elderly (>55 years) and young- and middle-aged (≤55 years) donor groups did not show any significant difference (P>0.05). After kidney donation, renal function measured by blood urea nitrogen (BUN) and serum creatinine of all donors returned to normal within one week, and no serious complications were noticed. In conclusion, renal dynamic imaging by (99m)Tc-DTPA had a good accuracy and repeatability in GFR evaluation for living kidney donors. Candidate donors with GFR between 70mL/(min×1.73m(2)) and 80mL/(min×1.73m(2)) can be selected as kidney donors after strict screening. In living kidney donors GFR is not significantly correlated with age or sex.

  13. Nuclear magnetic resonance imaging of induced renal lesions

    SciTech Connect

    London, D.A.; Davis, P.L.; Williams, R.D.; Crooks, L.E.; Sheldon, P.E.; Gooding, C.A.

    1983-07-01

    Nuclear magnetic resonance (NMR) images obtained after unilateral ligation of the ureter, renal artery, or renal vein in the rat were analyzed and compared with NMR images of the normal rat kidney. Anatomic and functional correlation of the induced renal lesions was made by concurrent CT and by gross examination of the excised kidneys. Many normal anatomic structures at the level of the renal hilum can be identified by high resolution NMR imaging. Differentiation of urine from renal parenchyma permits detection of gross changes both in renal function and in the mass of the renal parenchyma. NMR imaging is capable of diagnosing hydronephrosis, acute renal ischemia, and acute venous congestion in this rat model. In addition, a trend toward prolongation of the relaxation times T1 and T2 for abnormal renal parenchyma is demonstrated.

  14. Imaging the renal mass: a historical review.

    PubMed

    McClennan, Bruce L

    2014-11-01

    A matter of months after Roentgen's landmark discovery in 1895, Roentgen's rays were focused on diseases and disorders of the urinary tract, specifically the kidney. At the dawn of the 20th century, urologists in the United States and around the world quickly recognized that by using a variety of metal stylets and radiopaque contrast agents, such as silver salts, the upper urinary tract, namely the ureter, pelvis, and calyces, could be depicted with radiography. Renal cysts and tumors were diagnosed on the basis of deformities in the kidney. Retrograde pyelography dominated the imaging evaluation of the kidney until the discovery of a safe intravenous method for urinary tract imaging (ie, intravenous pyelography). Pioneers and pathfinders in the field of contrast media development and radiologic procedures helped give radiologists the lead role in the work-up of renal masses, an area where urologists once held forth. The subspecialty of uroradiology was born in the middle of the 20th century. Intravenous urography, nephrotomography, and diagnostic angiography with pharmacologic manipulation followed by cyst or mass puncture and biopsy yielded unrivaled specificity for the diagnosis and staging of benign and malignant renal masses. The advent of cross-sectional and multiplanar imaging and the profound effects they had and continue to have on the discovery and characterization of renal masses has been detailed in the pages of Radiology since the 1920s. Ultrasonography, nuclear imaging, computed tomographic scanning, magnetic resonance imaging, and positron emission tomography each have made a claim to a part of the imaging algorithm of modern uroradiologic practice.

  15. Imaging appearance of renal epithelioid angiomyolipomas.

    PubMed

    Ryan, Michael J; Francis, Isaac R; Cohan, Richard H; Davenport, Matthew S; Weizer, Alon; Hafez, Khaled; Kunju, Lakshmi P

    2013-01-01

    This study aimed to describe the computed tomographic (CT) imaging appearance of renal epithelioid angiomyolipomas (eAMLs). The CT scans and electronic medical records of 8 patients with histologically confirmed eAMLs identified by biopsy and/or surgical excision who had available imaging performed between 1995 and 2012 were reviewed. Preoperative CT imaging appearance, histologic features, and clinical follow-up were recorded for each patient. Macroscopic fat was identified in 3 (38%) of 8 eAMLs on preoperative CT imaging. Seven of the eAMLs demonstrated postcontrast enhancement of greater than 20 Hounsfield units. None of the eAMLs showed evidence of local invasion, vascular involvement, or distant metastases on the initial preoperative CT; however, 1 patient developed local recurrence and another developed distant metastatic disease on follow-up imaging. Epithelioid angiomyolipomas may or may not demonstrate macroscopic fat. Those with macroscopic fat do not possess any CT imaging characteristics that allow them to be distinguished from typical angiomyolipomas. Epithelioid angiomyolipomas without macroscopic fat are indistinguishable from renal cancers.

  16. Nuclear renal imaging in acute pyelonephritis

    SciTech Connect

    Handmaker, H.

    1982-07-01

    Patients with acute pyelonephritis may present with a spectrum of clinical signs and symptoms. There are few noninvasive diagnostic studies, however, to confirm or exclude this diagnosis. A small number of patients, generally those with severe disease, will demonstrate radiographic changes on excretory urography, but the lack of sensitivity of the IVP in early, acute pyelonephritis is well documented. Several radionuclide techniques have been proposed to assist in the earlier detection of this clinical problem including imaging with Mercury-197 chlormerodrin, Gallium-67 citrate, Technetium-99m glucoheptonate. Technetium-99m DMSA, and, more recently, Indium-111 labeled white blood cells. The success of the renal cortical imaging agents as well as those which localize in infection are described in this report. There appears to be a complimentary role or the cortical imaging agents and the radiopharmaceuticals which localize in bacterial infection. Cortical agents offer the advantage of specific assessment of functioning renal tissue and a convenient, rapid method for following the response to treatment in a noninvasive manner. A pattern is described which may be diagnostic; correlation with Gallium-67 citrate of Indium-111 WBCs may increase the probability of infection as the cause for the cortical abnormality. The measurement of differential renal function using cortical agents provides additional information to assist the clinician in predicting the late effects of infection. Improved sensitivity and specificity, and a reproducible method for following the response to therapy in patients with acute pyelonephritis are the advantages of the techniques described.

  17. Imaging of adrenal and renal hemorrhage.

    PubMed

    Hammond, Nancy A; Lostumbo, Antonella; Adam, Sharon Z; Remer, Erick M; Nikolaidis, Paul; Yaghmai, Vahid; Berggruen, Senta M; Miller, Frank H

    2015-10-01

    Hemorrhage of the kidneys and adrenal glands has many etiologies. In the adrenal glands, trauma, anticoagulation, stress, sepsis, surgery, and neoplasms are common causes of hemorrhage. In the kidneys, reasons for hemorrhage include trauma, bleeding diathesis, vascular diseases, infection, infarction, hemorrhagic cyst rupture, the Antopol-Goldman lesion, and neoplasms. Angiomyolipoma and renal cell carcinoma are the neoplasms most commonly associated with hemorrhage in the kidneys and adrenal cortical carcinoma, metastases, and pheochromocytoma are associated with hemorrhage in the adrenal glands. Understanding the computed tomography and magnetic resonance imaging features, and causes of hemorrhage in the kidneys and adrenal glands is critical. It is also important to keep in mind that mimickers of hemorrhage exist, including lymphoma in both the kidneys and adrenal glands, and melanoma metastases in the adrenal glands. Appropriate imaging follow-up of renal and adrenal hemorrhage should occur to exclude an underlying malignancy as the cause. If there is suspicion for malignancy that cannot be definitively diagnosed on imaging, surgery or biopsy may be warranted. Angiography may be indicated when there is a suspected underlying vascular disease. Unnecessary intervention, such as nephrectomy, may be avoided in patients with benign causes or no underlying disease. Appropriate management is dependent on accurate diagnosis of the cause of renal or adrenal hemorrhage and it is incumbent upon the radiologist to determine the etiology.

  18. Radionuclide imaging of rare congenital renal fusion anomalies.

    PubMed

    Volkan, Bilge; Ceylan, Emel; Kiratli, Pinar Ozgen

    2003-03-01

    Demonstration of a congenital renal anomaly plays an important role in the treatment of patients with renal infection. These patients are prone to infections because of coexisting urinary tract anomalies such as duplicated ureter, ureter opening anomalies, and urinary stasis. Assessment of renal parenchymal damage resulting from acute or chronic renal infection is the primary indication for radionuclide imaging with Tc-99m DMSA. In addition, this technique allows congenital anomalies to be identified. The authors review congenital renal fusion anomalies identified in children through Tc-99m DMSA imaging. They conclude that Tc-99m DMSA imaging can reveal important diagnostic information about various congenital anomalies, including fusion anomalies.

  19. A biphasic parameter estimation method for quantitative analysis of dynamic renal scintigraphic data

    NASA Astrophysics Data System (ADS)

    Koh, T. S.; Zhang, Jeff L.; Ong, C. K.; Shuter, B.

    2006-06-01

    Dynamic renal scintigraphy is an established method in nuclear medicine, commonly used for the assessment of renal function. In this paper, a biphasic model fitting method is proposed for simultaneous estimation of both vascular and parenchymal parameters from renal scintigraphic data. These parameters include the renal plasma flow, vascular and parenchymal mean transit times, and the glomerular extraction rate. Monte Carlo simulation was used to evaluate the stability and confidence of the parameter estimates obtained by the proposed biphasic method, before applying the method on actual patient study cases to compare with the conventional fitting approach and other established renal indices. The various parameter estimates obtained using the proposed method were found to be consistent with the respective pathologies of the study cases. The renal plasma flow and extraction rate estimated by the proposed method were in good agreement with those previously obtained using dynamic computed tomography and magnetic resonance imaging.

  20. Quantitative planar imaging in renal scintigraphy

    NASA Astrophysics Data System (ADS)

    Lárraga, J. M.; Martínez-Dávalos, A.; Martínez-Duncker, C.; Rodríguez, R. Herrera

    2002-08-01

    In this work we show the results of the implementation of the double energy window method (DEW) to correct for scatter and geometric mean of opposite image to correct for attenuation of radiation within the patient for absolute quantification of radiotracer in renal scintigraphy studies. We show that DEW method subestimates the scatter radiation within main energy window and that result in a 11% of maximun error for the determination of true activity of a renal kidney phantom. Moreover, in order to avoid transmission scans of patients we perform a Monte Carlo simulation (MC) for the determination of scatter component of the main energy window. The results of the MC simulation was validated with experimental data of emission studies.

  1. Multiphoton imaging of renal tissues in vitro.

    PubMed

    Peti-Peterdi, János

    2005-06-01

    The highly inhomogeneous and light-scattering structure of living renal tissue makes the application of conventional imaging techniques more difficult compared with other parenchymal organs. On the other hand, key physiological processes of the kidney, such as regulation of glomerular filtration, hemodynamics, concentration, and dilution, involve complex interactions between multiple cell types and otherwise inaccessible structures that necessitate visual approaches. An ideal solution is multiphoton excitation fluorescence microscopy, a state-of-the-art imaging technique superior for deep optical sectioning of living tissue samples. Here, we review the basics and advantages of multiphoton microscopy and provide examples for its application in renal physiology using dissected cortical and medullary tissues in vitro. In combination with microperfusion techniques, the major functions of the juxtaglomerular apparatus, tubuloglomerular feedback and renin release, can be studied with high spatial and temporal resolution. Salt-dependent changes in macula densa cell volume, vasoconstriction of the afferent arteriole, and activity of an intraglomerular precapillary sphincter composed of renin granular cells are visualized in real time. Release and tissue activity of renin can be studied on the individual granule level. Imaging of the living inner medulla shows how interstitial cells interconnect cells of the vasa recta, loop of Henle, and collecting duct. In summary, multiphoton microscopy is an exciting new optical sectioning technique that has great potential for numerous future developments and is ideal for applications that require deep optical sectioning of living tissue samples.

  2. WE-D-204-07: Development of An ImageJ Plugin for Renal Function Quantification: RenalQuant

    SciTech Connect

    Marques da Silva, A; Narciso, L

    2015-06-15

    Purpose: Commercial workstations usually have their own software to calculate dynamic renal functions. However, usually they have low flexibility and subjectivity on delimiting kidney and background areas. The aim of this paper is to present a public domain software, called RenalQuant, capable to semi-automatically draw regions of interest on dynamic renal scintigraphies, extracting data and generating renal function quantification parameters. Methods: The software was developed in Java and written as an ImageJ-based plugin. The preprocessing and segmentation steps include the user’s selection of one time frame with higher activity in kidney’s region, compared with background, and low activity in the liver. Next, the chosen time frame is smoothed using a Gaussian low pass spatial filter (σ = 3) for noise reduction and better delimitation of kidneys. The maximum entropy thresholding method is used for segmentation. A background area is automatically placed below each kidney, and the user confirms if these regions are correctly segmented and positioned. Quantitative data are extracted and each renogram and relative renal function (RRF) value is calculated and displayed. Results: RenalQuant plugin was validated using retrospective 20 patients’ 99mTc-DTPA exams, and compared with results produced by commercial workstation software, referred as reference. The renograms intraclass correlation coefficients (ICC) were calculated and false-negative and false-positive RRF values were analyzed. The results showed that ICC values between RenalQuant plugin and reference software for both kidneys’ renograms were higher than 0.75, showing excellent reliability. Conclusion: Our results indicated RenalQuant plugin can be trustingly used to generate renograms, using DICOM dynamic renal scintigraphy exams as input. It is user friendly and user’s interaction occurs at a minimum level. Further studies have to investigate how to increase RRF accuracy and explore how to solve

  3. High sensitive volumetric imaging of renal microcirculation in vivo using ultrahigh sensitive optical microangiography

    NASA Astrophysics Data System (ADS)

    Zhi, Zhongwei; Jung, Yeongri; Jia, Yali; An, Lin; Wang, Ruikang K.

    2011-03-01

    We present a non-invasive, label-free imaging technique called Ultrahigh Sensitive Optical Microangiography (UHSOMAG) for high sensitive volumetric imaging of renal microcirculation. The UHS-OMAG imaging system is based on spectral domain optical coherence tomography (SD-OCT), which uses a 47000 A-line scan rate CCD camera to perform an imaging speed of 150 frames per second that takes only ~7 seconds to acquire a 3D image. The technique, capable of measuring slow blood flow down to 4 um/s, is sensitive enough to image capillary networks, such as peritubular capillaries and glomerulus within renal cortex. We show superior performance of UHS-OMAG in providing depthresolved volumetric images of rich renal microcirculation. We monitored the dynamics of renal microvasculature during renal ischemia and reperfusion. Obvious reduction of renal microvascular density due to renal ischemia was visualized and quantitatively analyzed. This technique can be helpful for the assessment of chronic kidney disease (CKD) which relates to abnormal microvasculature.

  4. Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know

    PubMed Central

    Saade, Charbel; Deeb, Ibrahim Alsheikh; Mohamad, Maha; Al-Mohiy, Hussain; El-Merhi, Fadi

    2016-01-01

    Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted. PMID:26728701

  5. Glomerular filtration rate measured by 99mTc‐DTPA renal dynamic imaging is significantly lower than that estimated by the CKD‐EPI equation in horseshoe kidney patients

    PubMed Central

    Qi, Yan; Hu, Panpan; Wei, Kai; Jin, Meiling; Ma, Guangyu; Li, Qinggang; Xu, Baixuan; Chen, Xiangmei

    2016-01-01

    Abstract Aim Gate's glomerular filtration rate (gGFR) measured by 99mTc‐DTPA renal dynamic imaging and estimated GFR (eGFR) estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD‐EPI) equation are two indexes used to evaluate renal function. However, little is known about whether gGFR can be used to accurately assess renal function in horseshoe kidney (HSK) patients with renal fusion anomalies. Methods Nineteen HSK patients (HSK group) diagnosed by renal imaging and 38 CKD patients with “normal kidney shape” (non‐HSK group) matched to the HSK patients in terms of gender, age and biochemical indicators at Chinese PLA General Hospital were enrolled in this study. Gender, age, serum total protein (TP), albumin (ALB), blood urea nitrogen (BUN), serum creatinine (Scr), gGFR and eGFR were recorded and analyzed using χ2 test, t‐test, and Wilcoxon test which was presented as median(IQR). Results (1) There were no significant differences in gender, age, TP, ALB, BUN, Scr, or eGFR between these two groups. (2) In HSK patients, the renogram showed abnormal renal axis with the lower poles orientated medially. The timed uptake curve showed that the isotope excretion in the HSK group was slower than that in the non‐HSK group. (3) For all HSK patients, gGFR was significantly lower than eGFR (range –12.52 mL/min per 1.73m2 to –93.18 mL/min per 1.73m2). There was no significant difference in eGFR between the HSK [96.42 (36.02) mL/min per 1.73 m2] and non‐HSK groups [94.46 (33.00) mL/min per 1.73 m2]. The gGFR of the HSK group [41.18 (16.60) mL/min per 1.73m2] was much lower than that of the non‐HSK group [86.42(26.40) mL/min per 1.73m2, P < 0.001] and the eGFR of the HSK group (P < 0.001). The gGFR and eGFR of the non‐HSK group were not significantly different. Conclusion gGFR measured by 99mTc‐DTPA renal dynamic imaging is significantly lower than eGFR estimated by the CKD‐EPI equation, which indicates that

  6. Glomerular filtration rate measured by (99m) Tc-DTPA renal dynamic imaging is significantly lower than that estimated by the CKD-EPI equation in horseshoe kidney patients.

    PubMed

    Qi, Yan; Hu, Panpan; Xie, Yuansheng; Wei, Kai; Jin, Meiling; Ma, Guangyu; Li, Qinggang; Xu, Baixuan; Chen, Xiangmei

    2016-06-01

    Gate's glomerular filtration rate (gGFR) measured by (99m) Tc-DTPA renal dynamic imaging and estimated GFR (eGFR) estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation are two indexes used to evaluate renal function. However, little is known about whether gGFR can be used to accurately assess renal function in horseshoe kidney (HSK) patients with renal fusion anomalies. Nineteen HSK patients (HSK group) diagnosed by renal imaging and 38 CKD patients with "normal kidney shape" (non-HSK group) matched to the HSK patients in terms of gender, age and biochemical indicators at Chinese PLA General Hospital were enrolled in this study. Gender, age, serum total protein (TP), albumin (ALB), blood urea nitrogen (BUN), serum creatinine (Scr), gGFR and eGFR were recorded and analyzed using χ(2) test, t-test, and Wilcoxon test which was presented as median(IQR). (1) There were no significant differences in gender, age, TP, ALB, BUN, Scr, or eGFR between these two groups. (2) In HSK patients, the renogram showed abnormal renal axis with the lower poles orientated medially. The timed uptake curve showed that the isotope excretion in the HSK group was slower than that in the non-HSK group. (3) For all HSK patients, gGFR was significantly lower than eGFR (range -12.52 mL/min per 1.73m(2) to -93.18 mL/min per 1.73m(2) ). There was no significant difference in eGFR between the HSK [96.42 (36.02) mL/min per 1.73 m(2) ] and non-HSK groups [94.46 (33.00) mL/min per 1.73 m(2) ]. The gGFR of the HSK group [41.18 (16.60) mL/min per 1.73m(2) ] was much lower than that of the non-HSK group [86.42(26.40) mL/min per 1.73m(2) , P < 0.001] and the eGFR of the HSK group (P < 0.001). The gGFR and eGFR of the non-HSK group were not significantly different. gGFR measured by (99m) Tc-DTPA renal dynamic imaging is significantly lower than eGFR estimated by the CKD-EPI equation, which indicates that isotope renogram cannot accurately evaluate the

  7. Recent Advances in Magnetic Resonance Imaging Assessment of Renal Fibrosis.

    PubMed

    Li, Jia; An, Changlong; Kang, Lei; Mitch, William E; Wang, Yanlin

    2017-05-01

    CKD is a global public health problem. Renal fibrosis is a final common pathway leading to progressive loss of function in CKD. The degree of renal fibrosis predicts the prognosis of CKD. Recent studies have shown that bone marrow-derived fibroblasts contribute significantly to the development of renal fibrosis, which may yield novel therapeutic strategy for fibrotic kidney disease. Therefore, it is imperative to accurately assess the degree of renal fibrosis noninvasively to identify those patients who can benefit from antifibrotic therapy. In this review, we summarize recent advances in the assessment of renal fibrosis by magnetic resonance imaging. Published by Elsevier Inc.

  8. Complications of renal transplantation: evaluation with US and radionuclide imaging.

    PubMed

    Brown, E D; Chen, M Y; Wolfman, N T; Ott, D J; Watson, N E

    2000-01-01

    Following renal transplantation, patients are often evaluated with ultrasonography (US) or radionuclide imaging to assess renal function and the presence of possible complications. Both modalities are inexpensive, noninvasive, and nonnephrotoxic. A basic understanding of the surgical techniques commonly used for renal transplantation is useful when imaging these patients in order to recognize complications and to direct further imaging or intervention. The most frequent complications of renal transplantation include perinephric fluid collections; decreased renal function; and abnormalities of the vasculature, collecting system, and renal parenchyma. Perinephric fluid collections are common following transplantation, and their clinical significance depends on the type, location, size, and growth of the fluid collection, features that are well-evaluated with US. Causes of diminished renal function include acute tubular necrosis, rejection, and toxicity from medications. Radionuclide imaging is the most useful modality for assessing renal function. Vascular complications of transplantation include occlusion or stenosis of the arterial or venous supply, arteriovenous fistulas, and pseudoaneurysms. Although the standard for evaluating these vascular complications is angiography, US is an excellent noninvasive method for screening. Other transplant complications such as abnormalities of the collecting system and renal parenchyma are well-evaluated with both radionuclide imaging and US.

  9. Multiphoton imaging for assessing renal disposition in acute kidney injury

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Liang, Xiaowen; Wang, Haolu; Roberts, Darren M.; Roberts, Michael S.

    2016-11-01

    Estimation of renal function and drug renal disposition in acute kidney injury (AKI), is important for appropriate dosing of drugs and adjustment of therapeutic strategies, but is challenging due to fluctuations in kidney function. Multiphoton microscopy has been shown to be a useful tool in studying drug disposition in liver and can reflect dynamic changes of liver function. We extend this imaging technique to investigate glomerular filtration rate (GFR) and tubular transporter functional change in various animal models of AKI, which mimic a broad range of causes of AKI such as hypoxia (renal ischemia- reperfusion), therapeutic drugs (e.g. cisplatin), rhabdomyolysis (e.g. glycerol-induced) and sepsis (e.g. LPSinduced). The MPM images revealed acute injury of tubular cells as indicated by reduced autofluorescence and cellular vacuolation in AKI groups compared to control group. In control animal, systemically injected FITC-labelled inulin was rapidly cleared from glomerulus, while the clearance of FITC-inulin was significantly delayed in most of animals in AKI group, which may reflect the reduced GFR in AKI. Following intravenous injection, rhodamine 123, a fluorescent substrate of p-glycoprotein (one of tubular transporter), was excreted into urine in proximal tubule via p-glycoprotein; in response to AKI, rhodamine 123 was retained in tubular cells as revealed by slower decay of fluorescence intensity, indicating P-gp transporter dysfunction in AKI. Thus, real-time changes in GFR and transporter function can be imaged in rodent kidney with AKI using multiphoton excitation of exogenously injected fluorescent markers.

  10. Pediatric renal leukemia: spectrum of CT imaging findings.

    PubMed

    Hilmes, Melissa A; Dillman, Jonathan R; Mody, Rajen J; Strouse, Peter J

    2008-04-01

    The kidneys are a site of extramedullary leukemic disease that can be readily detected by CT. To demonstrate the spectrum of CT findings in children with renal leukemic involvement. Twelve children were identified retrospectively as having renal leukemic involvement by contrast-enhanced CT of the abdomen. Contrast-enhanced CT images through the kidneys of each patient were reviewed by two pediatric radiologists. Pertinent imaging findings and renal lengths were documented. The electronic medical record was accessed to obtain relevant clinical and pathologic information. Five patients with renal leukemic involvement presented with multiple bilateral low-attenuation masses, while three patients demonstrated large areas of wedge-shaped and geographic low attenuation. Four other patients presented with unique imaging findings, including a solitary unilateral low-attenuation mass, solitary bilateral low-attenuation masses, multiple bilateral low-attenuation masses including unilateral large conglomerate masses, and bilateral areas of ill-defined parenchymal low attenuation. Two patients showed unilateral nephromegaly, while eight other patients showed bilateral nephromegaly. Two patients had normal size kidneys. Two patients had elevated serum creatinine concentrations at the time of imaging. Renal leukemic involvement in children can present with a variety of CT imaging findings. Focal renal abnormalities as well as nephromegaly are frequently observed. Most commonly, renal leukemic involvement does not appear to impair renal function.

  11. Dynamic contrast-enhanced magnetic resonance imaging in the early evaluation of anti-angiogenic therapy in metastatic renal cell carcinoma.

    PubMed

    Panebianco, Valeria; Iacovelli, Roberto; Barchetti, Flavio; Altavilla, Amelia; Forte, Valerio; Sciarra, Alessandro; Cortesi, Enrico; Catalano, Carlo

    2013-12-01

    To evaluate the efficacy of dynamic contrast-enhanced magnetic resonance (DCE-MR) in the response to anti-angiogenic-targeted agents in patients with metastatic renal cell cancer (mRCC). Twenty-eight consecutive patients with sub-diaphragmatic metastases from mRCC were included in the protocol after signed informed consent. Baseline characteristics were collected and patients were first evaluated with a baseline computed tomography (CT) and DCE-MR, subsequently with a new DCE-MRI after 28 days of therapy and followed-up with CT until progression. Treatments were administered at standard doses. The changes of peak enhancement (ΔPE) and of the sum of longest tumor diameters (ΔLTD) were related to progression-free survival (PFS) and overall survival (OS). The median PFS was 11.4 months [95% Confidence Interval (CI): 7.9-14.7 months) and the parametric two-tailed Pearson's test showed a positive correlation between the median ΔPE and the median PFS (rp=0.809; p=0.015); no significant correlation was found between the median ΔLTD and the median PFS (rp=-0.446; p=0.27). The median OS was 23.3 months (95% CI: 13.6-33.0 months) and no significant correlation was found with the median ΔPE (rp=0.218; p=0.60) or with the median ΔLTD (rp=0.012; p=0.98). The ΔPE but not the ΔLTD was found to be significantly related to PFS; these preliminary results suggest extending the number of patients and investigating the possible relationship with other tumor characteristics and MRI parameters.

  12. Use of radionuclide renal imaging for clinical followup after extracorporeal shock wave lithotripsy of renal stones.

    PubMed

    Michaels, E K; Pavel, D G; Orellana, P; Montes, A; Olea, E

    1992-09-01

    Patients treated by extracorporeal shock wave lithotripsy (ESWL) are usually evaluated by excretory urography within 1 month after treatment to determine the clearance of stone debris and rule out asymptomatic obstruction. In an attempt to obtain more precise functional information, we used 99mtechnetium-diethylenetriaminepentaacetic acid and 131iodine-hippurate radionuclide renal imaging studies, and a plain abdominal radiograph as the initial followup study after ESWL of 64 kidneys in 55 patients. Of 53 kidneys studied within 60 days after ESWL 42 had abnormal radionuclide renal imaging studies demonstrating pelviocaliceal stasis, excretory delay or poor function, 8 of which required subsequent interventions for obstructing stone debris. Five patients had excretory delay after ESWL that was unexpected based on a pre-ESWL excretory urogram showing normal function without dilation. A subset of 23 patients with large stone burden or anatomical deformity from a prior operation had baseline radionuclide renal imaging studies before ESWL; function improved in 4 and worsened in 5 by radionuclide renal imaging studies after completion of treatment. A total of 19 patients had radionuclide renal imaging studies earlier (within 17 days) after ESWL because of poor function and/or large stone burden, and as expected they had evidence of obstruction from stone debris, which necessitated further followup. Our experience suggests that followup of ESWL by radionuclide renal imaging studies provides specific functional information that is of particular value in the management of patients with obstructing stone debris and/or diminished renal function. Radionuclide renal imaging studies may also reveal unsuspected obstruction or functional impairment after ESWL of uncomplicated stones, and is recommended as routine followup after ESWL.

  13. Magnetic Resonance Imaging as a Biomarker for Renal Cell Carcinoma

    PubMed Central

    Wu, Yan; Kwon, Young Suk; Labib, Mina; Foran, David J.; Singer, Eric A.

    2015-01-01

    As the most common neoplasm arising from the kidney, renal cell carcinoma (RCC) continues to have a significant impact on global health. Conventional cross-sectional imaging has always served an important role in the staging of RCC. However, with recent advances in imaging techniques and postprocessing analysis, magnetic resonance imaging (MRI) now has the capability to function as a diagnostic, therapeutic, and prognostic biomarker for RCC. For this narrative literature review, a PubMed search was conducted to collect the most relevant and impactful studies from our perspectives as urologic oncologists, radiologists, and computational imaging specialists. We seek to cover advanced MR imaging and image analysis techniques that may improve the management of patients with small renal mass or metastatic renal cell carcinoma. PMID:26609190

  14. Flip-flop phenomenon in radiohippuran renal imaging. A sign of obstructive nephropathy

    SciTech Connect

    Shih, W.J.; DeLand, F.H.; Domstad, P.A.

    1986-10-01

    In the dynamic radionuclide brain study, decreased flow in one cerebral hemisphere during the arterial phase followed by relatively increased radioactivity as compared with the contralateral hemisphere has been termed the flip-flop phenomenon, and reflects the development of collateral circulation to the affected side. In I-131 Hippuran renal imaging, relatively decreased activity in one kidney frequently is observed during the initial phase of the study, and is followed by a gradual increase of radioactivity in the late images when compared with the contralateral kidney. To evaluate the significance of this renal flip-flop phenomenon, the studies from 23 patients with these findings were retrospectively compared with the clinical data and findings from other diagnostic studies (CT, ultrasound, intravenous pyelogram, autopsy). Partial obstruction of the renal collecting system was found in all 23 patients. The causes were various malignant tumors in nine patients (colonic carcinoma, three patients; transitional cell carcinoma, three patients; prostatic carcinoma, two patients; seminoma, one patient), ureteropelvic obstruction in three patients, papillary necrosis in one patient, and ureteral fibrosis in one patient. The flip-flop phenomenon reflects asymmetric renal tubular function with decrease (prolonged parenchymal transit time) in the affected kidney as a result of ipsilateral obstruction of the collecting system, while contralateral renal function remains normal or relatively normal. The presence of the flip-flop phenomenon in an I-131 Hippuran renal study suggests the existence of some degree of collecting system obstruction that has persisted long enough to result in renal parenchymal damage.

  15. Eppur Si Muove: The dynamic nature of physiological control of renal blood flow by the renal sympathetic nerves.

    PubMed

    Schiller, Alicia M; Pellegrino, Peter Ricci; Zucker, Irving H

    2017-05-01

    Tubuloglomerular feedback and the myogenic response are widely appreciated as important regulators of renal blood flow, but the role of the sympathetic nervous system in physiological renal blood flow control remains controversial. Where classic studies using static measures of renal blood flow failed, dynamic approaches have succeeded in demonstrating sympathetic control of renal blood flow under normal physiological conditions. This review focuses on transfer function analysis of renal pressure-flow, which leverages the physical relationship between blood pressure and flow to assess the underlying vascular control mechanisms. Studies using this approach indicate that the renal nerves are important in the rapid regulation of the renal vasculature. Animals with intact renal innervation show a sympathetic signature in the frequency range associated with sympathetic vasomotion that is eliminated by renal denervation. In conscious rabbits, this sympathetic signature exerts vasoconstrictive, baroreflex control of renal vascular conductance, matching well with the rhythmic, baroreflex-influenced control of renal sympathetic nerve activity and complementing findings from other studies employing dynamic approaches to study renal sympathetic vascular control. In this light, classic studies reporting that nerve stimulation and renal denervation do not affect static measures of renal blood flow provide evidence for the strength of renal autoregulation rather than evidence against physiological renal sympathetic control of renal blood flow. Thus, alongside tubuloglomerular feedback and the myogenic response, renal sympathetic outflow should be considered an important physiological regulator of renal blood flow. Clinically, renal sympathetic vasomotion may be important for solving the problems facing the field of therapeutic renal denervation. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Renal masses in children. An integrated imaging approach to diagnosis

    SciTech Connect

    Wolfson, B.J.; Gainey, M.A.; Faerber, E.N.; Capitanio, M.A.

    1985-11-01

    In view of the continuing technologic advancements in the development and availability of diagnostic imaging modalities, it is appropriate to assess periodically the currently accepted approaches to the evaluation of renal masses in children. The roles, advantages, and disadvantages of plain film, intravenous urography, ultrasonography, radionuclide scintigraphy, computed tomography, angiography, and magnetic resonance imaging in the approach to the evaluation of renal masses in children are discussed. An integrated imaging approach that provides the most accurate and necessary information for diagnosis and treatment is recommended. 70 references.

  17. Nuclear magnetic resonance imaging of the kidney: renal masses

    SciTech Connect

    Hricak, H.; Williams, R.D.; Moon, K.L. Jr.; Moss, A.A.; Alpers, C.; Crooks, L.E.; Kaufman, L.

    1983-06-01

    Fifteen patients with a variety of renal masses were examined by nuclear magnetic resonance (NMR), computed tomography, ultrasound, and intravenous urography. NMR clearly differentiated between simple renal cysts and other renal masses. On spin echo images, the simple renal cyst appeared as a round or slightly oval, homogeneous low-intensity mass with characteristically long T1 and T2 values. The thickness of the cyst wall was not measurable. The cyst had a smooth outer margin and a distict, sharp interface with normal parenchyma. Hemorrhagic cysts were seen as high-intensity lesions. Renal cell carcinomas displayed a wide range of intensity. The T1 and T2 values of the tumors were always different from those of the surrounding renal parenchyma. Tumor pseudocapsule was identified in four of five patients examined. All carcinomas were accurately staged by NMR and extension of the tumor thrombus into the inferior vena cava was demonstrated. The authors predict that if these preliminary results are confirmed by data from a larger number of patients, NMR will play a significant role in renal imaging.

  18. [Imaging evaluation of renal function: principles and limitations].

    PubMed

    Vivier, P-H; Dolores, M; Le Cloirec, J; Beurdeley, M; Liard, A; Elbaz, F; Roset, J-B; Dacher, J-N

    2011-04-01

    The kidney performs multiple functions. Glomerular filtration is the most studied of these functions. In clinical practice, the surgical indication for patients with unilateral uropathy is frequently based on the split renal function as demonstrated by scintigraphy. MRI is not yet validated as a technique but nonetheless offers an interesting non-radiating alternative to achieve both morphological and functional renal evaluation. Recent pulse sequences such as diffusion, arterial spin labeling, and blood oxygenation dependent imaging may also provide additional information. CT and US remain of limited value for the evaluation of renal function.

  19. /sup 97/Ru-DMSA for delayed renal imaging. [Dogs

    SciTech Connect

    Oster, Z.H.; Som, P.; Gil, M.C.; Goldman, A.G.; Fairchild, R.G.; Meinken, G.E.; Srivastava, S.C.; Atkins, H.L.; Richards, P.; Brill, A.B.

    1981-01-01

    Dimercaptosuccinic acid (DMSA) was labeled with /sup 97/Ru both with and without the addition of SnCl.2H/sub 2/O. The tin-containing preparation was found to induce higher cortical deposition of /sup 97/Ru-DMSA than the tin-free preparation. Visualization of the renal cortex was excellent 4 to 48 hours after injection in normal dogs with renal insufficiency. It is concluded that /sup 97/Ru-(Sn+/sup 2/)-DMSA is a potentially useful renal imaging agent when delayed scintigraphy is necessary because of decompensaton of the kidneys.

  20. /sup 97/Ru-DMSA for delayed renal imaging

    SciTech Connect

    Oster, Z.H.; Som, P.; Gil, M.C.

    1981-10-01

    Dimercaptosuccinic acid (DMSA) was labeled with /sup 97/Ru both with and without the addition of SnCl-2H/sub 2/O. The tin-containing preparation was found to induce higher cortical deposition of /sup 97/Ru-DMSA than the tin-free preparation. Visualization of the renal cortex was excellent 4 to 48 hours after injection in normal dogs and in dogs with renal insufficiency. It is concluded that /sup 97/Ru-(SN/sup 2 +/)-DMSA is a potentially useful renal imaging agent when delayed scintigraphy is necessary because of decompensation of the kidneys.

  1. Usefulness of clearance parametric images in detection of regional renal parenchyma dysfunction.

    PubMed

    Kuśmierek, Jacek; Bieńkiewicz, Małgorzata; Konecki, Tomasz; Surma, Marian; Sosnowski, Marek; Płachcińska, Anna

    2017-01-01

    The aim of the study was to examine whether parametric clearance images (PAR) enhance diagnostic potential of a dynamic renal scintigraphy with detection of local dysfunction of kidneys, on a model of kidneys after treatment with extracorporeal shock wave lithotripsy (ESWL), MATERIAL AND METHODS: Kidneys after ESWL were accepted as a proper model for the implementation of this objective because of the previously proven damaging effect of a shock wave on renal parenchyma and known region of ESWL application. Forty patients (23 males and 17 females) at the age of 37 to 70 years (mean value 54) with untreated earlier single, one-sided nephrolithiasis, currently treated with ESWL, underwent a study. A dynamic renal 99mTc-EC scintigraphy was performed three times: before ESWL, a week and a month after this therapeutic intervention. PAR images generated with use of an in-house developed software were compared with summation (SUM) of images obtained from radiopharmaceutical uptake phase and quantitative global function parameters (GFP) of each kidney, like split function, MTT - mean transit time and PTT - parenchymal transit time. PAR and SUM images of all 40 kidneys before ESWL were normal. PAR images revealed local or diffused defects a week and a month after therapeutic intervention in statistically significantly larger numbers of kidneys than SUM images (19 vs. 6, p = 0.002 and 16 vs. 5, p = 0.003, respectively). A week after ESWL, when defects in PAR images were observed in about a half of all renal segments (29/57 - 51%) all GFP values were significantly worse than in kidneys without defects. A month after ESWL defects in PAR images could be observed in ab. 1/3 (17/48 - 35%) of segments and were less extensive, whereas GFP values did not differ significantly from values in kidneys without clearance function impairment in the PAR images. PAR images enhance diagnostic potential of a dynamic renal scintigraphy with detection of local function defects. These images

  2. Pilot Study of Renal Diffusion Tensor Imaging as a Correlate to Histopathology in Pediatric Renal Allografts.

    PubMed

    Li, Yi; Lee, Marsha M; Worters, Pauline W; MacKenzie, John D; Laszik, Zoltan; Courtier, Jesse L

    2017-06-01

    Fractional anisotropy (FA) is a measure of molecular motion obtained from diffusion tensor imaging (DTI). The objective of this study was to assess the use of FA as a noninvasive correlate of renal allograft histopathology. Sixteen pediatric renal allograft recipients were imaged using DTI in a prospective study, between October 2014 and January 2016, before a same-day renal allograft biopsy. The Kendall tau correlation coefficient was used to assess the relationship between cortical and medullary FA values and several clinically important Banff renal allograft histopathology scores. The Mann-Whitney U test was also used to compare cortical and medullary FA values in the region of biopsy in patients whose biopsy results did and in those whose biopsy results did not change clinical management. Medullary FA values had direct inverse correlation with several histopathology scores: tubulitis (designated "t" score in Banff pathologic classification, p < 0.04), interstitial inflammation (i score, p < 0.005), tubular atrophy (ct score, p < 0.002), and interstitial fibrosis (ci score, p < 0.007). Cortical FA values inversely correlated with peritubular capillaritis (ptc score, p < 0.02). Neither medullary nor cortical FA values correlated with glomerulitis (g score). At a b value of 800 s/mm(2), medullary FA values of pediatric renal allograft recipients whose renal biopsies prompted a change in clinical management (mean ± SD at a b value of 800 s/mm(2) = 0.262 ± 0.07; n = 9) were statistically different compared with the group whose biopsy results did not change clinical management (mean ± SD at a b value of 800 s/mm(2) = 0.333 ± 0.06; n = 7) (p < 0.006). FA is a noninvasive correlate of several important renal allograft histopathology scores and a potential noninvasive method of assessing renal allograft health in pediatric allograft recipients.

  3. Usefulness of parametric renal clearance images in the assessment of basic risk factors for renalnal clearance images in the assessment of basic risk factors for renal scarring in children with recurrent urinary tract infections.

    PubMed

    Pietrzak-Stelasiak, Ewa; Bieńkiewicz, Małgorzata; Woźnicki, Wojciech; Bubińska, Krystyna; Kowalewska-Pietrzak, Magdalena; Płachcińska, Anna; Kuśmierek, Jacek

    2017-01-01

    Clinically confirmed incidents of acute pyelonephritis (APN) following recurrent infections of urinary tract (UTI) form basic risk factors for renal scarring in children. Vesico-uretheral reflux (VUR) of higher grade is additional risk factor for this scarring. Opinions on diagnostic value of summed sequential images of renal uptake phase (SUM) of dynamic renal scintigraphy in detection of renal scars are diverse. However, several publications point to higher diagnostic efficacy of clearance parametric images (PAR) generated from this study. To establish a clinical value of parametric renal clearance images in detection of renal scarring. A prospective study was performed in a group of 91 children at the age of 4 to 18 years with recurrent UTI. Clinically documented incidents of APN were noted in 32 children: in 8 cases - one and in the remaining 24 - 2 to 5 (mean 3) incidents. In the remaining 59 patients only infections of the lower part of urinary tract were diagnosed. Static renal 99mTc-DMSA SPECT study and after 2-4 days dynamic renal studies (99mTc-EC) were performed in every patient not earlier than 6 months after the last documented incident of UTI. PAR images generated from a dynamic study by in-house developed software and SUM images were compared with a gold standard SPECT study. Percentages of children with detected renal scar(s) with SPECT and PAR methods amounted to 55% and 54%, respectively and were statistically significantly higher (p < 0.0001) than with SUM method - 31%. Scars in children with history of APN detected with SPECT and PAR methods were significantly more frequent than with infections of only lower part of urinary tract (72% vs. 46%; p = 0.017 and 69% vs. 46%; p = 0.036, respectively). A SUM method did not reveal statistically significant differences between frequencies of detection of scars in groups specified above - 38% vs. 27% (p = 0.31). Both SPECT and PAR methods showed also that frequencies of occurrence of renal scars in

  4. Dynamic Radiographic Imaging

    SciTech Connect

    Volkov, A.; Turley, D.; Veeser, L.; Lukyanov, N.; Yegorov, N.; Baker, S.A.; Mirenko, V.; Lewis, W.; Kuropatkin, Y.

    1999-06-01

    A radiographic system recently developed by American and Russian collaborators is designed to capture multiple images of a dynamic event lasting less than 10 microseconds. Various optical and electro-optical components were considered and their performance compared. The final system employed a solid crystal of lutetium oxyorthosilicate doped with cerium (LSO:Ce or LSO) for X-ray-to-light conversion with a coherent fiber optic bundle to relay the scintillator image to a streak camera with charge coupled device (CCD) readout. Resolution and sensitivity studies were carried out for this system on two different sources of X-rays: a 20 MeV microtron and a 70 MeV betatron.

  5. Functional renal imaging: new trends in radiology and nuclear medicine.

    PubMed

    Durand, Emmanuel; Chaumet-Riffaud, Philippe; Grenier, Nicolas

    2011-01-01

    The objective of this work is to compare the characteristics of various techniques for functional renal imaging, with a focus on nuclear medicine and magnetic resonance imaging. Even with low spatial resolution and rather poor signal-to-noise ratio, classical nuclear medicine has the advantage of linearity and good sensitivity. It remains the gold standard technique for renal relative functional assessment. Technetium-99m ((99m)Tc)-labeled diethylenetriamine penta-acetate remains the reference glomerular tracer. Tubular tracers have been improved: (123)I- or (131)I-hippuran, (99m)Tc-MAG3 and, recently, (99m)Tc-nitrilotriacetic acid. However, advancement in molecular imaging has not produced a groundbreaking tracer. Renal magnetic resonance imaging with classical gadolinated tracers probably has potential in this domain but has a lack of linearity and, therefore, its value still needs evaluation. Moreover, the advent of nephrogenic systemic fibrosis has delayed its expansion. Other developments, such as diffusion or blood oxygen level-dependent imaging, may have a role in the future. The other modalities have a limited role in clinical practice for functional renal imaging.

  6. Appraisal of lupus nephritis by renal imaging with gallium-67

    SciTech Connect

    Bakir, A.A.; Lopez-Majano, V.; Hryhorczuk, D.O.; Rhee, H.L.; Dunea, G.

    1985-08-01

    To assess the activity of lupus nephritis, 43 patients with systemic lupus erythematosus (SLE) were studied by gallium imaging. Delayed renal visualization 48 hours after the gallium injection, a positive result, was noted in 25 of 48 scans. Active renal disease was defined by the presence of hematuria, pyuria (10 or more red blood cells or white blood cells per high-power field), proteinuria (1 g or more per 24 hours), a rising serum creatinine level, or a recent biopsy specimen showing proliferative and/or necrotizing lesions involving more than 20 percent of glomeruli. Renal disease was active in 18 instances, inactive in 23, and undetermined in seven (a total of 48 scans). Sixteen of the 18 scans (89 percent) in patients with active renal disease showed positive findings, as compared with only four of 23 scans (17 percent) in patients with inactive renal disease (p less than 0.001). Patients with positive scanning results had a higher rate of hypertension (p = 0.02), nephrotic proteinuria (p = 0.01), and progressive renal failure (p = 0.02). Mild mesangial nephritis (World Health Organization classes I and II) was noted only in the patients with negative scanning results (p = 0.02) who, however, showed a higher incidence of severe extrarenal SLE (p = 0.04). It is concluded that gallium imaging is a useful tool in evaluating the activity of lupus nephritis.

  7. Renal cell therapy is associated with dynamic and individualized responses in patients with acute renal failure.

    PubMed

    Humes, H David; Weitzel, William F; Bartlett, Robert H; Swaniker, Fresca C; Paganini, Emil P

    2003-01-01

    Renal cell therapy in conjunction with continuous hemofiltration techniques may provide important cellular metabolic activities to patients with acute renal failure (ARF) and may thereby change the natural history of this disorder. The development of a tissue-engineered bioartificial kidney consisting of a conventional hemofiltration cartridge in series with a renal tubule assist device (RAD) containing 10(9) human renal proximal tubule cells provides an opportunity to evaluate this form of therapy in patients with ARF in the intensive care unit. Nine patients with ARF and multi-organ systems failure (MOSF) have been treated so far with a tissue-engineered kidney in an FDA-approved Phase I/II clinical study currently underway. Acute physiologic parameters and serum cytokine levels were assessed before, during and after treatment with a bioartificial kidney. Use of the RAD in this clinical setting demonstrates maintenance of cell viability and functionality. Cardiovascular stability appears to be maintained during RAD treatment. Human tubule cells in the RAD demonstrated differentiated metabolic and endocrinologic activity. Acute physiologic and plasma cytokine data demonstrate that renal cell therapy is associated with rapid and variable responses in patients with ARF and MOSF. The initial clinical experience with the bioartificial kidney and the RAD suggests that renal tubule cell therapy may provide a dynamic and individualized treatment program as assessed by acute physiologic and biochemical indices. Copyright 2003 S. Karger AG, Basel

  8. DIDA - Dynamic Image Disparity Analysis.

    DTIC Science & Technology

    1982-12-31

    Understanding, Dynamic Image Analysis , Disparity Analysis, Optical Flow, Real-Time Processing ___ 20. ABSTRACT (Continue on revere side If necessary aid identify...three aspects of dynamic image analysis must be studied: effectiveness, generality, and efficiency. In addition, efforts must be made to understand the...environment. A better understanding of the need for these Limiting constraints is required. Efficiency is obviously important if dynamic image analysis is

  9. Dynamics of Urinary Calprotectin after Renal Ischaemia

    PubMed Central

    Ebbing, Jan; Seibert, Felix S.; Pagonas, Nikolaos; Bauer, Frederic; Miller, Kurt; Kempkensteffen, Carsten; Günzel, Karsten; Bachmann, Alexander; Seifert, Hans H.; Rentsch, Cyrill A.; Ardelt, Peter; Wetterauer, Christian; Amico, Patrizia; Babel, Nina; Westhoff, Timm H.

    2016-01-01

    Background: Urinary calprotectin has been identified as a promising biomarker for acute kidney injury. To date, however, the time-dependent changes of this parameter during acute kidney injury remain elusive. The aim of the present work was to define the time-course of urinary calprotectin secretion after ischaemia/reperfusion-induced kidney injury in comparison to neutrophil gelatinase—associated lipocalin, thereby monitoring the extent of tubular damage in nephron sparing surgery for kidney tumours. Methods: The study population consisted of 42 patients. Thirty-two patients underwent either open or endoscopic nephron sparing surgery for kidney tumours. During the surgery, the renal arterial pedicle was clamped with a median ischaemic time of 13 minutes (interquartile range, 4.5–20.3 minutes) in 26 patients. Ten retro-peritoneoscopic living donor nephrectomy patients and 6 nephron sparing surgery patients in whom the renal artery was not clamped served as controls. Urinary calprotectin and neutrophil gelatinase—associated lipocalin concentrations were repeatedly measured by enzyme-linked immunosorbent assay and assessed according to renal function parameters. Results: Urinary concentrations of calprotectin and neutrophil gelatinase—associated lipocalin increased significantly after ischaemia/reperfusion injury, whereas concentrations remained unchanged after nephron sparing surgery without ischaemia/reperfusion injury and after kidney donation. Calprotectin and neutrophil gelatinase—associated lipocalin levels were significantly increased 2 and 8 hours, respectively, post-ischaemia. Both proteins reached maximal concentrations after 48 hours, followed by a subsequent persistent decrease. Maximal neutrophil gelatinase—associated lipocalin and calprotectin concentrations were 9-fold and 69-fold higher than their respective baseline values. The glomerular filtration rate was only transiently impaired at the first post-operative day after ischaemia

  10. Quantitative imaging of basic functions in renal (patho)physiology.

    PubMed

    Kang, Jung Julie; Toma, Ildiko; Sipos, Arnold; McCulloch, Fiona; Peti-Peterdi, Janos

    2006-08-01

    Multiphoton fluorescence microscopy offers the advantages of deep optical sectioning of living tissue with minimal phototoxicity and high optical resolution. More importantly, dynamic processes and multiple functions of an intact organ can be visualized in real time using noninvasive methods, and quantified. These studies aimed to extend existing methods of multiphoton fluorescence imaging to directly observe and quantify basic physiological parameters of the kidney including glomerular filtration rate (GFR) and permeability, blood flow, urinary concentration/dilution, renin content and release, as well as more integrated and complex functions like the tubuloglomerular feedback (TGF)-mediated oscillations in glomerular filtration and tubular flow. Streptozotocin-induced diabetes significantly increased single-nephron GFR (SNGFR) from 32.4 +/- 0.4 to 59.5 +/- 2.5 nl/min and glomerular permeability to a 70-kDa fluorophore approximately eightfold. The loop diuretic furosemide 2-fold diluted and increased approximately 10-fold the volume of distal tubular fluid, while also causing the release of 20% of juxtaglomerular renin content. Significantly higher speeds of individual red blood cells were measured in intraglomerular capillaries (16.7 +/- 0.4 mm/s) compared with peritubular vessels (4.7 +/- 0.2 mm/s). Regular periods of glomerular contraction-relaxation were observed, resulting in oscillations of filtration and tubular flow rate. Oscillations in proximal and distal tubular flow showed similar cycle times ( approximately 45 s) to glomerular filtration, with a delay of approximately 5-10 and 25-30 s, respectively. These innovative technologies provide the most complex, immediate, and dynamic portrayal of renal function, clearly depicting the components and mechanisms involved in normal physiology and pathophysiology.

  11. Image diagnosis of parathyroid glands in chronic renal failure

    SciTech Connect

    Takagi, H.; Tominaga, Y.; Uchida, K.; Yamada, N.; Morimoto, T.; Yasue, M.

    1983-07-01

    Twenty-two out of 31 patients with chronic renal failure and secondary hyperparathyroidism who underwent parathyroidectomy before operation underwent non-invasive image diagnosis of parathyroid glands by computed tomography (CT), scintigraphy with /sup 201/TlCl and /sup 99m/TcO/sup 4 +/, and/or ultrasonography. CT visualized 39 of 45 parathyroid glands (86.7%), weighing more than 500 mg. Scintigraphy with a subtraction method using a computer performed the diagnosis in 19 of 27 glands (70.4%). Ultrasonography detected 21 of 27 glands (77.8%). Image diagnosis was also useful in the postoperative follow-up study. The non-invasive image diagnosis of parathyroid glands in patients with chronic renal failure is thus valuable for 1) definite diagnosis of secondary hyperparathyroidism, 2) localization, and 3) diagnosis for effectiveness of conservative treatment.

  12. Chronic urinary obstruction: evaluation of dynamic contrast-enhanced MR urography for measurement of split renal function.

    PubMed

    Claudon, Michel; Durand, Emmanuel; Grenier, Nicolas; Prigent, Alain; Balvay, Daniel; Chaumet-Riffaud, Philippe; Chaumoitre, Kathia; Cuenod, Charles-André; Filipovic, Marina; Galloy, Marie-Agnès; Lemaitre, Laurent; Mandry, Damien; Micard, Emilien; Pasquier, Cédric; Sebag, Guy H; Soudant, Marc; Vuissoz, Pierre-André; Guillemin, Francis

    2014-12-01

    To evaluate if measurement of split renal function ( SRF split renal function ) with dynamic contrast material-enhanced ( DCE dynamic contrast enhanced ) magnetic resonance (MR) urography is equivalent to that with renal scintigraphy ( RS renal scintigraphy ) in patients suspected of having chronic urinary obstruction. The study protocol was approved by the institutional ethics committee of the coordinating center on behalf of all participating centers. Informed consent was obtained from all adult patients or both parents of children. This prospective, comparative study included 369 pediatric and adult patients from 14 university hospitals who were suspected of having chronic or intermittent urinary obstruction, and data from 295 patients with complete data were used for analysis. SRF split renal function was measured by using the area under the curve and the Patlak-Rutland methods, including successive review by a senior and an expert reviewer and measurement of intra- and interobserver agreement for each technique. An equivalence test for mean SRF split renal function was conducted with an α of 5%. Reproducibility was substantial to almost perfect for both methods. Equivalence of DCE dynamic contrast enhanced MR urography and RS renal scintigraphy for measurement of SRF split renal function was shown in patients with moderately dilated kidneys (P < .001 with the Patlak-Rutland method). However, in severely dilated kidneys, the mean SRF split renal function measurement was underestimated by 4% when DCE dynamic contrast enhanced MR urography was used compared with that when RS renal scintigraphy was used. Age and type of MR imaging device had no significant effect. For moderately dilated kidneys, equivalence of DCE dynamic contrast enhanced MR urography to RS renal scintigraphy was shown, with a standard deviation of approximately 12% between the techniques, making substitution of DCE dynamic contrast enhanced MR urography for RS renal scintigraphy acceptable. For

  13. Applications of condensed dynamic images

    SciTech Connect

    Klein, H.A.

    1986-03-01

    In appropriate cases, information from a dynamic series of nuclear images may be condensed into a single image with one spatial and one temporal dimension. A useful elaboration of the method consists of the masking out of undesired spatial regions. The versatility of such condensed dynamic images is illustrated by examples derived from gastroesophageal and pulmonary studies. Advantages of the method include obviating the need to examine and comprehend multiple images as well as enabling economical archiving of image data. Its diagnostic potential is particularly evident in esophageal transit and infant gastroesophageal reflux studies.

  14. Imaging regional renal function parameters using radionuclide tracers

    NASA Astrophysics Data System (ADS)

    Qiao, Yi

    A compartmental model is given for evaluating kidney function accurately and noninvasively. This model is cast into a parallel multi-compartment structure and each pixel region (picture element) of kidneys is considered as a single kidney compartment. The loss of radionuclide tracers from the blood to the kidney and from the kidney to the bladder are modelled in great detail. Both the uptake function and the excretion function of the kidneys can be evaluated pixel by pixel, and regional diagnostic information on renal function is obtained. Gamma Camera image data are required by this model and a screening test based renal function measurement is provided. The regional blood background is subtracted from the kidney region of interest (ROI) and the kidney regional rate constants are estimated analytically using the Kuhn-Pucker multiplier method in convex programming by considering the input/output behavior of the kidney compartments. The detailed physiological model of the peripheral compartments of the system, which is not available for most radionuclide tracers, is not required in the determination of the kidney regional rate constants and the regional blood background factors within the kidney ROI. Moreover, the statistical significance of measurements is considered to assure the improved statistical properties of the estimated kidney rate constants. The relations between various renal function parameters and the kidney rate constants are established. Multiple renal function measurements can be found from the renal compartmental model. The blood radioactivity curve and the regional (or total) radiorenogram determining the regional (or total) summed behavior of the kidneys are obtained analytically with the consideration of the statistical significance of measurements using convex programming methods for a single peripheral compartment system. In addition, a new technique for the determination of 'initial conditions' in both the blood compartment and the kidney

  15. Diffusion-weighted magnetic resonance imaging in cystic renal masses

    PubMed Central

    Balyemez, Fikret; Aslan, Ahmet; Inan, Ibrahim; Ayaz, Ercan; Karagöz, Vildan; Özkanli, Sıdıka Şeyma; Acar, Murat

    2017-01-01

    Introduction: We aimed to introduce the diagnostic value of diffusion-weighted (DWI) magnetic resonance imaging (MRI) for distinguishing benign and malignant renal cystic masses. Methods: Abdominal DWI-MRIs of patients with Bosniak categories 2F, 3, and 4 cystic renal masses were evaluated retrospectively. Cystic masses were assigned as benign or malignant according to histopathological or followup MRI findings and compared with apparent diffusion coefficient (ADC) values. Results: There were 30 patients (18 males and 12 females, mean age was 59.23 ± 12.08 years [range 38–83 years]) with cystic renal masses (eight Bosniak category 2F, 12 Bosniak category 3, 10 Bosniak category 4). Among them, 14 cysts were diagnosed as benign and 16 as malignant by followup imaging or histopathological findings. For the malignant lesions, the mean ADC values were lower than for benign lesions (p=0.001). An ADC value of ≤2.28 ×10−6 mm2/s or less had a sensitivity of 75% and a specificity of 92.86% for detecting malignancy. Conclusions: ADC can improve the diagnostic performance of MRI in the evaluation of complex renal cysts when used together with conventional MRI sequences. PMID:28163806

  16. Detection of inflammation following renal ischemia by magnetic resonance imaging.

    PubMed

    Jo, Sang-Kyung; Hu, Xuzhen; Kobayashi, Hisataka; Lizak, Martin; Miyaji, Takehiko; Koretsky, Alan; Star, Robert A

    2003-07-01

    Determining the disease culprits in human acute renal failure (ARF) has been difficult because of the paucity of renal biopsies and the lack of noninvasive methods to determine the location or cause of renal injury. Recently, ultrasmall superparamagnetic iron oxide (USPIO) particles have been used to detect inflammation in animal models. Therefore, we tested if USPIO enhanced magnetic resonance imaging (MRI) could detect inflammation in ischemic ARF in rats. Rats were subjected to 40 or 60 minutes of bilateral ischemia or injected with mercuric chloride. MR images were obtained before and 24 hours after USPIO injection, and the signal intensity decrease in the outer medulla was measured. Cells containing iron particles were identified by iron staining and transmission electron microscopy (TEM). Leukocytes were identified by ED-1 and chloracetate esterase staining. Injection of USPIO particles caused a black band to appear in the outer medulla at 48, 72, and 120 hours after ischemia. This band was not detected in normal animals, 24 hours after ischemia, or 48 hours after mercuric chloride injection. The signal intensity change in the outer medulla correlated with serum creatinine and the number of iron particle containing cells. Most infiltrating cells were macrophages, and iron particles were present inside lysosomes of macrophages. USPIO injection did not alter renal function in normal or ischemic animals. USPIO-enhanced MRI could detect inflammation noninvasively from 48 hours after 40 or 60 minutes of renal ischemia in rats. This method might be useful to understand the pathogenesis of human ARF and to evaluate the effectiveness of anti-inflammatory agents.

  17. A new fluorescent imaging of renal inflammation with RCP.

    PubMed

    Nakamura, Kentaro; Tabata, Yasuhiko

    2010-12-20

    The objective of this study is to design a fluorescent imaging agent with R-Gel, one of the recombinant polymers (RCP), for renal inflammation. The R-Gel based on human type I collagen has multiple Arg-Gly-Asp (RGD) motifs which are ligands for some types of integrin receptors on the cell surface. After intravenous administration of R-Gel labeled by Cy7 of a fluorescent dye to three animal models of nephritis mousse, interstitial nephritis (by using UUO model mice), glomerulonephritis (HIGA mice), and ischemia-reperfusion injured kidney (I/R mice), the extent of fluorescent imaging at the renal inflammation was assessed. The Cy7-labeled R-Gel was accumulated in the inflammation site to a significantly greater extent than in the normal one at 24h after administration. The renal pattern of fluorescent imaging was similar to that of administration anti-Mac1 antibody. Taken together, it is conceivable that the R-Gel was targeted to macrophages infiltrated into the inflammation site of kidney. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Renal cell carcinoma: histological classification and correlation with imaging findings.

    PubMed

    Muglia, Valdair F; Prando, Adilson

    2015-01-01

    Renal cell carcinoma (RCC) is the seventh most common histological type of cancer in the Western world and has shown a sustained increase in its prevalence. The histological classification of RCCs is of utmost importance, considering the significant prognostic and therapeutic implications of its histological subtypes. Imaging methods play an outstanding role in the diagnosis, staging and follow-up of RCC. Clear cell, papillary and chromophobe are the most common histological subtypes of RCC, and their preoperative radiological characterization, either followed or not by confirmatory percutaneous biopsy, may be particularly useful in cases of poor surgical condition, metastatic disease, central mass in a solitary kidney, and in patients eligible for molecular targeted therapy. New strategies recently developed for treating renal cancer, such as cryo and radiofrequency ablation, molecularly targeted therapy and active surveillance also require appropriate preoperative characterization of renal masses. Less common histological types, although sharing nonspecific imaging features, may be suspected on the basis of clinical and epidemiological data. The present study is aimed at reviewing the main clinical and imaging findings of histological RCC subtypes.

  19. Renal cell carcinoma: histological classification and correlation with imaging findings*

    PubMed Central

    Muglia, Valdair F.; Prando, Adilson

    2015-01-01

    Renal cell carcinoma (RCC) is the seventh most common histological type of cancer in the Western world and has shown a sustained increase in its prevalence. The histological classification of RCCs is of utmost importance, considering the significant prognostic and therapeutic implications of its histological subtypes. Imaging methods play an outstanding role in the diagnosis, staging and follow-up of RCC. Clear cell, papillary and chromophobe are the most common histological subtypes of RCC, and their preoperative radiological characterization, either followed or not by confirmatory percutaneous biopsy, may be particularly useful in cases of poor surgical condition, metastatic disease, central mass in a solitary kidney, and in patients eligible for molecular targeted therapy. New strategies recently developed for treating renal cancer, such as cryo and radiofrequency ablation, molecularly targeted therapy and active surveillance also require appropriate preoperative characterization of renal masses. Less common histological types, although sharing nonspecific imaging features, may be suspected on the basis of clinical and epidemiological data. The present study is aimed at reviewing the main clinical and imaging findings of histological RCC subtypes. PMID:26185343

  20. Dynamic granularity of imaging systems

    SciTech Connect

    Geissel, Matthias; Smith, Ian C.; Shores, Jonathon E.; Porter, John L.

    2015-11-04

    Imaging systems that include a specific source, imaging concept, geometry, and detector have unique properties such as signal-to-noise ratio, dynamic range, spatial resolution, distortions, and contrast. Some of these properties are inherently connected, particularly dynamic range and spatial resolution. It must be emphasized that spatial resolution is not a single number but must be seen in the context of dynamic range and consequently is better described by a function or distribution. We introduce the “dynamic granularity” Gdyn as a standardized, objective relation between a detector’s spatial resolution (granularity) and dynamic range for complex imaging systems in a given environment rather than the widely found characterization of detectors such as cameras or films by themselves. We found that this relation can partly be explained through consideration of the signal’s photon statistics, background noise, and detector sensitivity, but a comprehensive description including some unpredictable data such as dust, damages, or an unknown spectral distribution will ultimately have to be based on measurements. Measured dynamic granularities can be objectively used to assess the limits of an imaging system’s performance including all contributing noise sources and to qualify the influence of alternative components within an imaging system. Our article explains the construction criteria to formulate a dynamic granularity and compares measured dynamic granularities for different detectors used in the X-ray backlighting scheme employed at Sandia’s Z-Backlighter facility.

  1. Dynamic granularity of imaging systems

    DOE PAGES

    Geissel, Matthias; Smith, Ian C.; Shores, Jonathon E.; ...

    2015-11-04

    Imaging systems that include a specific source, imaging concept, geometry, and detector have unique properties such as signal-to-noise ratio, dynamic range, spatial resolution, distortions, and contrast. Some of these properties are inherently connected, particularly dynamic range and spatial resolution. It must be emphasized that spatial resolution is not a single number but must be seen in the context of dynamic range and consequently is better described by a function or distribution. We introduce the “dynamic granularity” Gdyn as a standardized, objective relation between a detector’s spatial resolution (granularity) and dynamic range for complex imaging systems in a given environment rathermore » than the widely found characterization of detectors such as cameras or films by themselves. We found that this relation can partly be explained through consideration of the signal’s photon statistics, background noise, and detector sensitivity, but a comprehensive description including some unpredictable data such as dust, damages, or an unknown spectral distribution will ultimately have to be based on measurements. Measured dynamic granularities can be objectively used to assess the limits of an imaging system’s performance including all contributing noise sources and to qualify the influence of alternative components within an imaging system. Our article explains the construction criteria to formulate a dynamic granularity and compares measured dynamic granularities for different detectors used in the X-ray backlighting scheme employed at Sandia’s Z-Backlighter facility.« less

  2. Initial human experience with Rubidium-82 renal PET/CT imaging.

    PubMed

    Tahari, Abdel K; Bravo, Paco E; Rahmim, Arman; Bengel, Frank M; Szabo, Zsolt

    2014-02-01

    Preclinical data have shown that Rubidium-82 chloride ((82)Rb) is a radiotracer with high first pass extraction and slow washout in the kidneys. The goal of this study was to investigate the feasibility of human kidney imaging with (82)Rb positron emission tomography (PET) and obtain quantitative data of its uptake non-invasively. Eight healthy volunteers underwent dynamic PET/CT imaging with (82)Rb. A preprogrammed pump was used to insure reproducible injections. Tissue time activity curves were generated from the renal cortex. An input function was derived from the left ventricular blood pool (LVBP), the descending thoracic aorta and the abdominal aorta. Renal blood flow was estimated by applying a two-compartment kinetic model. Results obtained with different input functions were compared. Radiotracer accumulation was rapid and reached a plateau within 15-30 s after the bolus entered the kidneys. The derived K1 and k2 parameters were reproducible using input functions obtained from diverse vascular locations. K1 averaged 1.98 ± 0.14 mL/min/g. The average k2 was 0.35 ± 0.11/min. Correlation between K1 values obtained from the LVBP from different bed positions when the kidneys and abdominal aorta were in the same field of view was excellent (R = 0.95). Non-invasive quantitative human kidney imaging with (82)Rb PET is feasible. Advantages of renal PET with (82)Rb include excellent image quality with high image resolution and contrast. (82)Rb has potential as a clinical renal imaging agent in humans. © 2013 The Royal Australian and New Zealand College of Radiologists.

  3. Survey on the Use of Nuclear Renal Imaging in the United States.

    PubMed

    Archer, Kelly D; Bolus, Norman E

    2016-12-01

    Throughout the years, the role of nuclear medicine departments in the care of renal patients has changed as a result of technologic advancements and other factors. This study evaluated the current role of nuclear renal imaging.

  4. Dynamic response of blood vessel in acute renal failure.

    PubMed

    Pantovic, Suzana; Rosic, Gvozden; Obradovic, Zdravko; Rankovic, Goran; Stojiljkovic, Nenad; Rosic, Mirko

    2009-01-01

    In this study we postulated that during acute renal failure induced by gentamicin the transient or dynamic response of blood vessels could be affected, and that antioxidants can prevent the changes in dynamic responses of blood vessels. The new approach to ex vivo blood vessel experiments in which not only the end points of vessels response within the time interval is considered, but also dynamics of this response, was used in this paper. Our results confirm the alteration in dynamic response of blood vessels during the change of pressure in gentamicin-treated animals. The beneficial effects of vitamin C administration to gentamicin-treated animals are also confirmed through: lower level of blood urea and creatinine and higher level of potassium. The pressure dynamic responses of isolated blood vessels show a faster pressure change in gentamicin-treated animals (8.07 +/- 1.7 s vs. 5.64 +/- 0.18 s). Vitamin C administration induced slowdown of pressure change back to the control values. The pressure dynamic properties, quantitatively defined by comparative pressure dynamic and total pressure dynamic, confirm the alteration in dynamic response of blood vessels during the change of pressure in gentamicin-treated animals and beneficial effects of vitamin C administration.

  5. Renal

    MedlinePlus

    ... term "renal" refers to the kidney. For example, renal failure means kidney failure. Related topics: Kidney disease Kidney disease - diet Kidney failure Kidney function tests Renal scan Kidney transplant

  6. Renal Masses Detected on FDG PET/CT in Patients With Lymphoma: Imaging Features Differentiating Primary Renal Cell Carcinomas From Renal Lymphomatous Involvement.

    PubMed

    Nicolau, Carlos; Sala, Evis; Kumar, Anita; Goldman, Debra A; Schoder, Heiko; Hricak, Hedvig; Vargas, Hebert Alberto

    2017-04-01

    The purpose of this study is to analyze the (18)F-FDG PET/CT features of solid renal masses detected in patients with lymphoma and to evaluate the ability of PET/CT to differentiate renal cell carcinoma (RCC) from renal lymphomatous involvement. Thirty-six patients with solid renal masses on PET/CT performed for staging or follow-up of lymphoma were evaluated retrospectively. The features recorded for each renal mass included the following standardized uptake values (SUVs) on PET/CT: the maximum SUV (SUVmax), the mean SUV (SUVmean), the ratio of the SUVmax of the tumor to that of the normal kidney cortex, the ratio of the SUVmean of the tumor to that of the normal kidney cortex, the ratio of the SUVmax of the tumor to that of the normal liver, and the ratio of the SUVmean of the tumor to that of the normal liver. Renal mass size and margins (well defined vs infiltrative) and the presence of calcifications were evaluated on CT. Renal biopsy results were used as the reference standard. Relationships between imaging parameters and histopathologic findings were assessed. Of the 36 renal masses evaluated, 22 (61.1%) were RCCs and 14 (38.9%) were renal lymphomas. All SUV metrics were higher for renal lymphomas than for RCCs (p < 0.0001, for all). All renal lymphomas had an SUVmax higher than 5.98 g/mL (median, 10.99 g/mL), whereas all RCCs had an SUVmax lower than 5.26 g/mL (median, 2.91 g/mL). No statistically significant differences in mass size or margins were found between RCCs and renal lymphoma. PET/CT features may be useful for differentiating RCCs from renal involvement in patients with lymphoma with solid renal masses.

  7. Dynamical Imaging using Spatial Nonlinearity

    DTIC Science & Technology

    2014-01-29

    a 532nm laser is incident on a resolution chart followed by a holographic diffuser. A lens then images the resolution chart onto a photorefractive... laser sources), a Hamiltonian or eikonal description of wave evolution is suitable[51]. Accordingly, any (nonlinear) dynamics that can benefit from a...terms of imaging, the results generalized the field of computational imaging, on both the device and algorithmic levels. They also introduced many new

  8. Improved assessment of renal lesions in pregnancy with magnetic resonance imaging.

    PubMed

    Putra, Lydia G Johns; Minor, Thomas X; Bolton, Damien M; Appu, Sreevinas; Dowling, Caroline R; Neerhut, Gregory J

    2009-09-01

    To ascertain the potential utility of magnetic resonance imaging in providing additional clarification of those solid renal mass lesions identified at routine antenatal ultrasonography in early pregnancy and influencing the management of such lesions. We present 7 patients in whom magnetic resonance imaging was used to diagnose, stage, and monitor renal lesions detected during pregnancy. Magnetic resonance imaging provided for improved imaging of renal mass lesions identified at antenatal ultrasonography, without the use of ionizing radiation, and permitted management determined by optimal radiographic assessment of such lesions without fetal irradiation. Magnetic resonance imaging is the most appropriate method to further investigate renal masses identified at routine antenatal ultrasonography early in pregnancy.

  9. Imaging-based diagnosis of acute renal allograft rejection

    PubMed Central

    Thölking, Gerold; Schuette-Nuetgen, Katharina; Kentrup, Dominik; Pawelski, Helga; Reuter, Stefan

    2016-01-01

    Kidney transplantation is the best available treatment for patients with end stage renal disease. Despite the introduction of effective immunosuppressant drugs, episodes of acute allograft rejection still endanger graft survival. Since efficient treatment of acute rejection is available, rapid diagnosis of this reversible graft injury is essential. For diagnosis of rejection, invasive core needle biopsy of the graft is the “gold-standard”. However, biopsy carries the risk of significant graft injury and is not immediately feasible in patients taking anticoagulants. Therefore, a non-invasive tool assessing the whole organ for specific and fast detection of acute allograft rejection is desirable. We herein review current imaging-based state of the art approaches for non-invasive diagnostics of acute renal transplant rejection. We especially focus on new positron emission tomography-based as well as targeted ultrasound-based methods. PMID:27011915

  10. Renal Graft Fibrosis and Inflammation Quantification by an Automated Fourier-Transform Infrared Imaging Technique.

    PubMed

    Vuiblet, Vincent; Fere, Michael; Gobinet, Cyril; Birembaut, Philippe; Piot, Olivier; Rieu, Philippe

    2016-08-01

    Renal interstitial fibrosis and interstitial active inflammation are the main histologic features of renal allograft biopsy specimens. Fibrosis is currently assessed by semiquantitative subjective analysis, and color image analysis has been developed to improve the reliability and repeatability of this evaluation. However, these techniques fail to distinguish fibrosis from constitutive collagen or active inflammation. We developed an automatic, reproducible Fourier-transform infrared (FTIR) imaging-based technique for simultaneous quantification of fibrosis and inflammation in renal allograft biopsy specimens. We generated and validated a classification model using 49 renal biopsy specimens and subsequently tested the robustness of this classification algorithm on 166 renal grafts. Finally, we explored the clinical relevance of fibrosis quantification using FTIR imaging by comparing results with renal function at 3 months after transplantation (M3) and the variation of renal function between M3 and M12. We showed excellent robustness for fibrosis and inflammation classification, with >90% of renal biopsy specimens adequately classified by FTIR imaging. Finally, fibrosis quantification by FTIR imaging correlated with renal function at M3, and the variation in fibrosis between M3 and M12 correlated well with the variation in renal function over the same period. This study shows that FTIR-based analysis of renal graft biopsy specimens is a reproducible and reliable label-free technique for quantifying fibrosis and active inflammation. This technique seems to be more relevant than digital image analysis and promising for both research studies and routine clinical practice.

  11. Glomerular Dynamic Studies of the Pathogenesis of Acute Renal Failure.

    DTIC Science & Technology

    1984-06-30

    IAD-A174 113 GLOMERULAR DYNAMIC STUDIES OF THE PATHOGENESIS OF ANOTE 1/1 RENAL FAILURE(U) VIRGINIA COMNWEALTH UNIV RICHMOND I D E OKEN 3e JUN 84...8217i1 . d /or 1 Special June 30, 1984 Supported by U.S. ARMY MEDICAL RESEARCH AND DEVELOPMENT COMMAND Fort Detrick, Frederick, Maryland 21701-5012 Contract...values might be underestimated by tubular inulin leakage if measured in the customary fashion.) Nephron filtration fraction was estimated from the

  12. Dynamics of renal electrolyte excretion in growing mice.

    PubMed

    Schmidt, Katharina; Ripper, Maria; Tegtmeier, Ines; Humberg, Evelyn; Sterner, Christina; Reichold, Markus; Warth, Richard; Bandulik, Sascha

    2013-01-01

    Genetically modified mice represent important models for elucidating renal pathophysiology, but gene deletions frequently cause severe failure to thrive. In such cases, the analysis of the phenotype is often limited to the first weeks of life when renal excretory function undergoes dramatic physiological changes. Here, we investigated the postnatal dynamics of urinary ion excretion in mice. The profiles of urinary electrolyte excretion of mice were examined from birth until after weaning using an automated ion chromatography system. Postnatally, mice grew about 0.4 g/day, except during two phases with slower weight gain: (i) directly after birth during adaptation to extrauterine conditions (P0-P2) and (ii) during the weaning period (P15-P21), when nutrition changed from mother's milk to solid chow and water. During the first 3 days after birth, remarkable changes in urinary Na(+), Ca(2+), Mg(2+), and phosphate concentrations occurred, whereas K(+) and Cl(-) concentrations hardly changed. From days 4-14 after birth, Na(+), Ca(2+), Mg(2+), K(+), and Cl(-) concentrations remained relatively stable at low levels. Urinary concentrations of creatinine, NH4(+), phosphate, and sulfate constantly increased from birth until after weaning. Profiles of salt excretion in KCNJ10(-/-) mice exemplified the relevance of age-dependent analysis of urinary excretion. In conclusion, the most critical phases for analysis of renal ion excretion during the first weeks of life are directly after birth and during the weaning period. The age dependence of urinary excretion varies for the different ions. This should be taken into consideration when the renal phenotype of mice is investigated during the first weeks of life.

  13. Comparison of magnetic resonance imaging and radionuclide imaging in the evaluation of renal transplant failure

    SciTech Connect

    Goldsmith, M.S.; Tanasescu, D.E.; Waxman, A.D.; Crues, J.V. III

    1988-04-01

    Magnetic resonance imaging (MRI) was compared with radionuclide scintigraphy (RNS) in 16 patients with renal transplants undergoing renal failure to determine which modality could best discriminate between rejection, acute tubular necrosis (ATN), and cyclosporin nephrotoxicity (CN). Although all rejecting transplants had reduced corticomedullary differentiation (CMD) on T1-weighted MR images, four of five cases of ATN had appearances that could not be distinguished from rejection. A normal CMD suggests nonrejection, but diminished CMD is nonspecific. Tc-99m DTPA/I-131 hippuran RNS was superior to MRI in differentiating rejection from ATN. Although ATN and CN have similar RNS patterns, this distinction can usually be made based on the clinical time course. Other potential uses of MRI in the evaluation of the renal transplants are discussed.

  14. Detection of urinary extravasation by delayed technetium-99m DTPA renal imaging

    SciTech Connect

    Taki, J.; Tonami, N.; Aburano, T.; Hisada, K.

    1986-08-01

    Delayed imaging with Tc-99m DTPA renal scintigraphy demonstrated urinary extravasation in a patient with acute anuria in whom early sequential imaging showed no abnormal extrarenal radionuclide accumulation.

  15. Renal biochemistry variables and ultrasonographic imaging in healthy Squirrel monkeys (Saimiri collinsi).

    PubMed

    Lins E Lins, Fernanda Luiza de Miranda; Mayor, Pedro; Silva Filho, Ednaldo; Imbeloni, Aline Amaral; Bandeira da Silva, Wellington; Monteiro, Maria Vivina Barros; Nunes-Pinheiro, Diana Célia Sousa; Monteiro, Frederico Ozanan Barros

    2017-03-01

    The combined use of renal biochemistry and ultrasonographic imaging may improve the correct management of renal disease. Although renal disease is frequently observed in nonhuman primates, renal function markers have not yet been studied in Squirrel monkeys (Saimiri collinsi). The aim of this study was to establish normal renal biochemistry variables and ultrasonographic features in Squirrel monkeys. Renal biochemistry variables and ultrasonographic images were documented in 29 healthy Squirrel monkeys (15 males and 14 females). Urea, serum creatinine (SCr), and uric acid (UA) concentrations were measured by kinetic assay. Cystatin C (CysC) was analyzed by immunonephelometry. A multiple frequency linear array probe (5-12 MHz) was used for ultrasonographic imaging. The studied indicators of renal function were related to sex, age, and body mass. Serum creatinine was influenced by sex and body mass. Serum concentration of urea, UA, and CysC were not influenced by sex, age, and body mass. Ultrasonographic images provided accurate and comprehensive data for making clinical decisions for Squirrel monkeys. The total renal volume was only influenced by the body mass nested in sex and was positively correlated to body mass. Right renal volume was bigger than the left one. Normative standards for the renal evaluation, including biochemistry and ultrasonography, in the Squirrel monkey have been established correlated to age, sex, and body mass. © 2017 American Society for Veterinary Clinical Pathology.

  16. Image-based retrieval system and computer-aided diagnosis system for renal cortical scintigraphy images

    NASA Astrophysics Data System (ADS)

    Mumcuoğlu, Erkan; Nar, Fatih; Uğur, Omer; Bozkurt, M. Fani; Aslan, Mehmet

    2008-03-01

    Cortical renal (kidney) scintigraphy images are 2D images (256x256) acquired in three projection angles (posterior, right-posterior-oblique and left-posterior-oblique). These images are used by nuclear medicine specialists to examine the functional morphology of kidney parenchyma. The main visual features examined in reading the images are: size, location, shape and activity distribution (pixel intensity distribution within the boundary of each kidney). Among the above features, activity distribution (in finding scars if any) was found to have the least interobserver reproducibility. Therefore, in this study, we developed an image-based retrieval (IBR) and a computer-based diagnosis (CAD) system, focused on this feature in particular. The developed IBR and CAD algorithms start with automatic segmentation, boundary and landmark detection. Then, shape and activity distribution features are computed. Activity distribution feature is obtained using the acquired image and image set statistics of the normal patients. Active Shape Model (ASM) technique is used for more accurate kidney segmentation. In the training step of ASM, normal patient images are used. Retrieval performance is evaluated by calculating precision and recall. CAD performance is evaluated by specificity and sensitivity. To our knowledge, this paper is the first IBR or CAD system reported in the literature on renal cortical scintigraphy images.

  17. Value of obtaining renal images following brain scintigraphy with technetium-99m glucoheptonate

    SciTech Connect

    Moreno, A.J.; Rodriguez, A.A.; Spicer, M.J.; Jackson, R.E.; Byrd, B.F.; Turnbull, G.L.

    1986-08-01

    The value of adding an extra view of the kidneys immediately following brain imaging with Tc-99m glucoheptonate was investigated in a two-year retrospective study at our institution. Between October 1982 and October 1984, 561 individuals underwent Tc-99m glucoheptonate brain imaging with the added renal view. Twenty-nine of these individuals (5.2%) demonstrated renal abnormalities. The abnormal renal findings were clinically correlated in 24 of these persons. Sixteen (67%) of these 24 individuals were unaware of any renal abnormality. Useful information can be obtained from renal images incidental to brain imaging at no added expense or radiation exposure to the patient, and at a minimal cost in time to the imaging clinic.

  18. Renal Sodium Gradient Orchestrates a Dynamic Antibacterial Defense Zone.

    PubMed

    Berry, Miriam R; Mathews, Rebeccah J; Ferdinand, John R; Jing, Chenzhi; Loudon, Kevin W; Wlodek, Elizabeth; Dennison, Thomas W; Kuper, Christoph; Neuhofer, Wolfgang; Clatworthy, Menna R

    2017-08-24

    Lower urinary tract infections are among the most common human bacterial infections, but extension to the kidneys is rare. This has been attributed to mechanical forces, such as urine flow, that prevent the ascent of bladder microbes. Here, we show that the regional hypersalinity, required for the kidney's urine-concentrating function, instructs epithelial cells to produce chemokines that localize monocyte-derived mononuclear phagocytes (MNPs) to the medulla. This hypersaline environment also increases the intrinsic bactericidal and neutrophil chemotactic activities of MNPs to generate a zone of defense. Because MNP positioning and function are dynamically regulated by the renal salt gradient, we find that patients with urinary concentrating defects are susceptible to kidney infection. Our work reveals a critical accessory role for the homeostatic function of a vital organ in optimizing tissue defense. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Dynamic imaging with electron microscopy

    ScienceCinema

    Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

    2016-07-12

    Livermore researchers have perfected an electron microscope to study fast-evolving material processes and chemical reactions. By applying engineering, microscopy, and laser expertise to the decades-old technology of electron microscopy, the dynamic transmission electron microscope (DTEM) team has developed a technique that can capture images of phenomena that are both very small and very fast. DTEM uses a precisely timed laser pulse to achieve a short but intense electron beam for imaging. When synchronized with a dynamic event in the microscope's field of view, DTEM allows scientists to record and measure material changes in action. A new movie-mode capability, which earned a 2013 R&D 100 Award from R&D Magazine, uses up to nine laser pulses to sequentially capture fast, irreversible, even one-of-a-kind material changes at the nanometer scale. DTEM projects are advancing basic and applied materials research, including such areas as nanostructure growth, phase transformations, and chemical reactions.

  20. Dynamic imaging with electron microscopy

    SciTech Connect

    Campbell, Geoffrey; McKeown, Joe; Santala, Melissa

    2014-02-20

    Livermore researchers have perfected an electron microscope to study fast-evolving material processes and chemical reactions. By applying engineering, microscopy, and laser expertise to the decades-old technology of electron microscopy, the dynamic transmission electron microscope (DTEM) team has developed a technique that can capture images of phenomena that are both very small and very fast. DTEM uses a precisely timed laser pulse to achieve a short but intense electron beam for imaging. When synchronized with a dynamic event in the microscope's field of view, DTEM allows scientists to record and measure material changes in action. A new movie-mode capability, which earned a 2013 R&D 100 Award from R&D Magazine, uses up to nine laser pulses to sequentially capture fast, irreversible, even one-of-a-kind material changes at the nanometer scale. DTEM projects are advancing basic and applied materials research, including such areas as nanostructure growth, phase transformations, and chemical reactions.

  1. Magnetic resonance imaging of urea transporter knockout mice reveals two distinct types of renal pelvic abnormality

    PubMed Central

    Jacob, Vinitha; Harbaugh, Calista; Dietz, John R.; Fenton, Robert A.; Kim, Soo Mi; Castrop, Hayo; Schnermann, Jurgen; Knepper, Mark A.; Chou, Chung-Lin; Anderson, Stasia A.

    2008-01-01

    Many transgenic and knockout mouse models with increased urine flow have been noted to have structural abnormalities of the renal pelvis and renal inner medulla. Here, we describe an approach for in vivo study of such abnormalities in mice using high resolution contrast enhanced T1-weighted magnetic resonance imaging (MRI). The studies were carried out in mice in which the UT-A isoform 1 and 3 urea transporters had been deleted (UT-A1/3-/- mice). The experiments revealed three distinct variations in the appearance of the renal pelvis in these mice: 1) normal kidneys with no accumulation of contrast agent in the renal pelvis; 2) frank right-sided unilateral hydronephrosis with marked atrophy of the renal medulla, seen relatively infrequently; and 3) a renal pelvic reflux pattern characterized by the presence of contrast agent in the renal pelvis surrounding the renal inner medulla, with no substantial atrophy of the renal medulla, seen in most UT-A1/3-/- mice with advancing age. The reflux pattern was also found in aquaporin-1 knockout mice. UT-A1/3-/- mice also manifested increased mean arterial pressure. Feeding the UT-A1/3-/- mice a low protein diet did not prevent the demonstrated abnormalities of the renal pelvis. These studies demonstrate the feasibility of real time imaging of renal pelvic structure in genetically manipulated mice, providing a tool for non-destructive, temporal studies of kidney structure. PMID:18854850

  2. Renal sympathetic denervation increases renal blood volume per cardiac cycle: a serial magnetic resonance imaging study in resistant hypertension.

    PubMed

    Delacroix, Sinny; Chokka, Ramesh G; Nelson, Adam J; Wong, Dennis T; Sidharta, Samuel; Pederson, Stephen M; Rajwani, Adil; Nimmo, Joanne; Teo, Karen S; Worthley, Stephen G

    2017-01-01

    Preclinical studies have demonstrated improvements in renal blood flow after renal sympathetic denervation (RSDN); however, such effects are yet to be confirmed in patients with resistant hypertension. Herein, we assessed the effects of RSDN on renal artery blood flow and diameter at multiple time points post-RSDN. Patients (n=11) with systolic blood pressures ≥160 mmHg despite taking three or more antihypertensive medications at maximum tolerated dose were recruited into this single-center, prospective, non-blinded study. Magnetic resonance imaging indices included renal blood flow and renal artery diameters at baseline, 1 month and 6 months. In addition to significant decreases in blood pressures (p<0.0001), total volume of blood flow per cardiac cycle increased by 20% from 6.9±2 mL at baseline to 8.4±2 mL (p=0.003) at 1 month and to 8.0±2 mL (p=0.04) 6 months post-procedure, with no changes in the renal blood flow. There was a significant decrease in renal artery diameters from 7±2 mm at baseline to 6±1 mm (p=0.03) at 1 month post-procedure. This decrease was associated with increases in maximum velocity of blood flow from 73±20 cm/s at baseline to 78±19 cm/s at 1 month post-procedure. Notably, both parameters reverted to 7±2 mm and 72±18 cm/s, respectively, 6 months after procedure. RSDN improves renal physiology as evidenced by significant improvements in total volume of blood flow per cardiac cycle. Additionally, for the first time, we identified a transient decrease in renal artery diameters immediately after procedure potentially caused by edema and inflammation that reverted to baseline values 6 months post-procedure.

  3. Renal sympathetic denervation increases renal blood volume per cardiac cycle: a serial magnetic resonance imaging study in resistant hypertension

    PubMed Central

    Delacroix, Sinny; Chokka, Ramesh G; Nelson, Adam J; Wong, Dennis T; Sidharta, Samuel; Pederson, Stephen M; Rajwani, Adil; Nimmo, Joanne; Teo, Karen S; Worthley, Stephen G

    2017-01-01

    Aim Preclinical studies have demonstrated improvements in renal blood flow after renal sympathetic denervation (RSDN); however, such effects are yet to be confirmed in patients with resistant hypertension. Herein, we assessed the effects of RSDN on renal artery blood flow and diameter at multiple time points post-RSDN. Methods and results Patients (n=11) with systolic blood pressures ≥160 mmHg despite taking three or more antihypertensive medications at maximum tolerated dose were recruited into this single-center, prospective, non-blinded study. Magnetic resonance imaging indices included renal blood flow and renal artery diameters at baseline, 1 month and 6 months. In addition to significant decreases in blood pressures (p<0.0001), total volume of blood flow per cardiac cycle increased by 20% from 6.9±2 mL at baseline to 8.4±2 mL (p=0.003) at 1 month and to 8.0±2 mL (p=0.04) 6 months post-procedure, with no changes in the renal blood flow. There was a significant decrease in renal artery diameters from 7±2 mm at baseline to 6±1 mm (p=0.03) at 1 month post-procedure. This decrease was associated with increases in maximum velocity of blood flow from 73±20 cm/s at baseline to 78±19 cm/s at 1 month post-procedure. Notably, both parameters reverted to 7±2 mm and 72±18 cm/s, respectively, 6 months after procedure. Conclusion RSDN improves renal physiology as evidenced by significant improvements in total volume of blood flow per cardiac cycle. Additionally, for the first time, we identified a transient decrease in renal artery diameters immediately after procedure potentially caused by edema and inflammation that reverted to baseline values 6 months post-procedure. PMID:28919800

  4. Renal nuclear imaging and analysis in pediatric patients.

    PubMed

    Ash, J M; Gilday, D L

    1980-06-01

    Because a renal scan reflects the physiologic configuration and function of the kidney, it provides information that cannot be obtained with conventional intravenous pyelography. It is particularly useful in children with hydronephrosis, vesicoureteral reflux, chronic pyelonephritis, and congenital renal anomalies.

  5. Atherosclerotic renal artery stenosis in the post-CORAL era part 1: the renal penumbra concept and next-generation functional diagnostic imaging.

    PubMed

    Sag, Alan Alper; Inal, Ibrahim; Okcuoglu, John; Rossignol, Patrick; Ortiz, Alberto; Afsar, Baris; Sos, Thomas A; Kanbay, Mehmet

    2016-04-01

    After three neutral trials in which renal artery stenting failed to improve renal function or reduce cardiovascular and renal events, the controversy surrounding diagnosis and treatment of atherosclerotic renal artery stenosis and renovascular hypertension has led to paradigm shifts in the diagnostic algorithm. Noninvasive determination of earlier events (cortex hypoxia and renal artery hemodynamic changes) will supersede late sequelae (calcific stenosis, renal cortical thinning). Therefore, this review proposes the concept of renal penumbra in defining at-risk ischemic renal parenchyma. The complex field of functional renal magnetic resonance imaging will be reviewed succinctly in a clinician-directed fashion. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  6. Imaging the clear cell renal cell carcinoma proteome

    PubMed Central

    Morgan, Todd M.; Seeley, Erin H.; Fadare, Oluwole; Caprioli, Richard M.; Clark, Peter E.

    2012-01-01

    Introduction A key barrier to identification of tissue biomarkers of clear cell renal cell carcinoma (ccRCC) is the heterogeneity of protein expression within tissue. However, by providing spectra for every 0.05 mm2 area of tissue, imaging mass spectrometry (IMS) reveals the spatial distribution of peptides. We sought to determine whether this approach could be used to identify and map protein signatures of ccRCC. Methods We constructed two tissue microarrays (TMA) with two cores each of matched tumor and normal tissue from nephrectomy specimens of 70 patients with ccRCC. Samples were analyzed by matrix-assisted laser desorption ionization (MALDI) time-of-flight mass spectrometry (MS). Peptide signatures were identified within each TMA that differentiated cancer from normal tissue and then cross-validated. MS/MS sequencing was performed to determine identities of select differentially expressed peptides, and immunohistochemistry was used for validation. Results Peptide signatures were identified that demonstrated a classification accuracy within each TMA of 94.7–98.5% for each 0.05mm2 spot (spectrum) and 96.9–100% for each tissue core. Cross-validation across TMA's revealed classification accuracies of 82.6–84.7% for each spot and 88.9–92.4% for each core. We identified vimentin, histone 2A.X, and alpha-enolase as proteins with greater expression in cancer tissue, and validated this by immunohistochemistry. Conclusions IMS was able to identify and map specific peptides that accurately distinguished malignant from normal renal tissue, demonstrating its potential as a novel, high-throughput approach to ccRCC biomarker discovery. Given the multiple pathways and known heterogeneity involved in tumors such as ccRCC, multiple peptide signatures that maintain their spatial relationships may outperform traditional protein biomarkers. PMID:23009866

  7. Renal relevant radiology: radiologic imaging in autosomal dominant polycystic kidney disease.

    PubMed

    Rahbari-Oskoui, Frederic; Mittal, Ankush; Mittal, Pardeep; Chapman, Arlene

    2014-02-01

    Autosomal-dominant polycystic kidney disease is a systemic disorder and the most common hereditary renal disease, which is characterized by cyst growth, progressive renal enlargement, and development of renal failure. The cystic nature of autosomal dominant polycystic kidney disease and its renal and extrarenal complications (kidney stones, cyst hemorrhage, intracerebral aneurysm, liver cysts, cardiac valve abnormalities, etc.) give radiologic imaging studies a central role in the management of these patients. This article reviews the indications, comparative use, and limitation of various imaging modalities (ultrasonography, magnetic resonance imaging, computerized tomography scan, Positron emission tomography scan, and renal scintigraphy) for the diagnosis and management of complications in autosomal dominant polycystic kidney disease. Finally, this work provides evidence for the value of total kidney volume to predict disease progression in autosomal dominant polycystic kidney disease.

  8. Renal Relevant Radiology: Radiologic Imaging in Autosomal Dominant Polycystic Kidney Disease

    PubMed Central

    Rahbari-Oskoui, Frederic; Mittal, Ankush; Mittal, Pardeep

    2014-01-01

    Summary Autosomal-dominant polycystic kidney disease is a systemic disorder and the most common hereditary renal disease, which is characterized by cyst growth, progressive renal enlargement, and development of renal failure. The cystic nature of autosomal dominant polycystic kidney disease and its renal and extrarenal complications (kidney stones, cyst hemorrhage, intracerebral aneurysm, liver cysts, cardiac valve abnormalities, etc.) give radiologic imaging studies a central role in the management of these patients. This article reviews the indications, comparative use, and limitation of various imaging modalities (ultrasonography, magnetic resonance imaging, computerized tomography scan, Positron emission tomography scan, and renal scintigraphy) for the diagnosis and management of complications in autosomal dominant polycystic kidney disease. Finally, this work provides evidence for the value of total kidney volume to predict disease progression in autosomal dominant polycystic kidney disease. PMID:24370765

  9. Urine aquaporin 1 and perilipin 2 differentiate renal carcinomas from other imaged renal masses and bladder and prostate cancer.

    PubMed

    Morrissey, Jeremiah J; Mobley, Jonathan; Figenshau, R Sherburne; Vetter, Joel; Bhayani, Sam; Kharasch, Evan D

    2015-01-01

    To evaluate the sensitivity and specificity of urine aquaporin 1 (AQP1) and perilipin 2 (PLIN2) concentrations to diagnose clear cell or papillary renal cell carcinoma (RCC) by comparing urine concentrations of these unique biomarkers in patients with RCC, noncancer renal masses, bladder cancer, and prostate cancer. From February 1, 2012, through October 31, 2012, preoperative urine samples were obtained from patients with a presumptive diagnosis of RCC based on an imaged renal mass, prostate cancer, or transitional cell bladder cancer. Imaged renal masses were diagnosed postnephrectomy—as malignant or benign—by histology. Urine AQP1 and PLIN2 concentrations were measured by using a sensitive and specific Western blot and normalized to urine creatinine concentration. Median concentrations of urine AQP1 and PLIN2 in patients with clear cell and papillary RCC (n=47) were 29 and 36 relative absorbance units/mg urine creatinine, respectively. In contrast, median concentrations in patients with bladder cancer (n=22) and prostate cancer (n=27), patients with chromophobe tumors (n=7), and patients with benign renal oncocytomas (n=9) and angiomyolipomas (n=7) were all less than 10 relative absorbance units/mg urine creatinine (Kruskal-Wallis test, P<.001 vs RCC for both biomarkers) and comparable with those in healthy controls. The area under the receiver operating characteristic curve ranged from 0.99 to 1.00 for both biomarkers. These results support the specificity and sensitivity of urine AQP1 and PLIN2 concentrations for RCC. These novel tumor-specific proteins have high clinical validity and high potential as specific screening biomarkers for clear cell and papillary RCC as well as in the differential diagnosis of imaged renal masses. clinicaltrials.gov Identifier: NCT00851994. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  10. Exophytic renal masses: angular interface with renal parenchyma for distinguishing benign from malignant lesions at MR imaging.

    PubMed

    Verma, Sachit K; Mitchell, Donald G; Yang, Roberta; Roth, Christopher G; O'Kane, Patrick; Verma, Manisha; Parker, Laurence

    2010-05-01

    To retrospectively determine whether benign exophytic renal masses can be distinguished from renal cell carcinoma (RCC) on the basis of angular interface at single-shot fast spin-echo (SE) T2-weighted magnetic resonance (MR) imaging. This retrospective study was compliant with HIPAA and was approved by the institutional review board. Patient informed consent was waived. A total of 162 exophytic (2 cm or greater) renal masses in 152 patients (103 men, 49 women; mean age, 58 years; age range, 23-85 years) were included. Two radiologists independently recorded the mass size and angular interface on single-shot fast SE T2-weighted MR images. Surgical pathologic report and MR follow-up were used as reference standards. Logistic regression analysis was used to examine the usefulness of these variables for differentiating benign masses from RCCs. Diagnostic performance was analyzed by comparing values for area under receiver operating characteristic curve (A(z)). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of angular interface for diagnosing benign masses were calculated. Reader agreement was assessed with kappa-weighted statistics and intraclass correlation coefficients (ICCs). Of 162 masses, 65 were benign, and 97 were RCCs. The sensitivity, specificity, PPV, NPV, and A(z) of angular interface for diagnosing benign masses were 78%, 100%, 100%, 87%, and 0.813, respectively. Angular interface (P < .001) was a significant predictor of benign renal mass but mass size (P = .66) was not. There was almost perfect interobserver agreement for mass size (ICC = 0.96) and angular interface (kappa = 0.91). The presence of an angular interface with the renal parenchyma at single-shot fast SE T2-weighted MR imaging is a strong predictor of benignity in an exophytic renal mass 2 cm or greater in diameter with high specificity and diagnostic accuracy.

  11. MR imaging of renal cortical tumours: qualitative and quantitative chemical shift imaging parameters.

    PubMed

    Karlo, Christoph A; Donati, Olivio F; Burger, Irene A; Zheng, Junting; Moskowitz, Chaya S; Hricak, Hedvig; Akin, Oguz

    2013-06-01

    To assess qualitative and quantitative chemical shift MRI parameters of renal cortical tumours. A total of 251 consecutive patients underwent 1.5-T MRI before nephrectomy. Two readers (R1, R2) independently evaluated all tumours visually for a decrease in signal intensity (SI) on opposed- compared with in-phase chemical shift images. In addition, SI was measured on in- and opposed-phase images (SI(IP), SI(OP)) and the chemical shift index was calculated as a measure of percentage SI change. Histopathology served as the standard of reference. A visual decrease in SI was identified significantly more often in clear cell renal cell carcinoma (RCCs) (R1, 73 %; R2, 64 %) and angiomyolipomas (both, 80 %) than in oncocytomas (29 %, 12 %), papillary (29 %, 17 %) and chromophobe RCCs (13 %, 9 %; all, P < 0.05). Median chemical shift index was significantly greater in clear cell RCC and angiomyolipoma than in the other histological subtypes (both, P < 0.001). Interobserver agreement was fair for visual (kappa, 0.4) and excellent for quantitative analysis (concordance correlation coefficient, 0.80). A decrease in SI on opposed-phase chemical shift images is not an identifying feature of clear cell RCCs or angiomyolipomas, but can also be observed in oncocytomas, papillary and chromophobe RCCs. After excluding angiomyolipomas, a decrease in SI of more than 25 % was diagnostic for clear cell RCCs. • Chemical shift MRI offers new information about fat within renal tumours. • Opposed-phase signal decrease can be observed in all renal cortical tumours. • A greater than 25 % decrease in signal appears to be diagnostic for clear cell RCCs.

  12. Immediate renal imaging and renography with /sup 99m/Tc methylene diphosphonate to assess renal blood flow, excretory function, and anatomy

    SciTech Connect

    Glass, E.C.; DeNardo, G.L.; Hines, H.H.

    1980-04-01

    /sup 99m/Tc methylene diphosphonate (/sup 99m/Tc MDP) was evaluated as a clinical renal imaging agent in 20 patients referred for bone scintigraphy. Sequential scintigraphy, which was started immediately after injection, yielded blood flow studies of high quality, and subsequent images accurately delineated renal anatomy and excretion in nonazotemic patients. In comparison with delayed images, early images were vastly superior in quality and demonstrated improved target-to-nontarget activity ratios (p < 0.001) and improved lesion detectability (p < 0.01). Renal imaging performed incidental to bone scintigraphy with MDP can be greatly enhanced by initiating sequential scintigraphy immediately after injection.

  13. Quantitative high-resolution renal perfusion imaging using 3-dimensional through-time radial generalized autocalibrating partially parallel acquisition.

    PubMed

    Wright, Katherine L; Chen, Yong; Saybasili, Haris; Griswold, Mark A; Seiberlich, Nicole; Gulani, Vikas

    2014-10-01

    Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) examinations of the kidneys provide quantitative information on renal perfusion and filtration. However, these examinations are often difficult to implement because of respiratory motion and their need for a high spatiotemporal resolution and 3-dimensional coverage. Here, we present a free-breathing quantitative renal DCE-MRI examination acquired with a highly accelerated stack-of-stars trajectory and reconstructed with 3-dimensional (3D) through-time radial generalized autocalibrating partially parallel acquisition (GRAPPA), using half and quarter doses of gadolinium contrast. Data were acquired in 10 asymptomatic volunteers using a stack-of-stars trajectory that was undersampled in-plane by a factor of 12.6 with respect to Nyquist sampling criterion and using partial Fourier of 6/8 in the partition direction. Data had a high temporal (2.1-2.9 seconds per frame) and spatial (approximately 2.2 mm) resolution with full 3D coverage of both kidneys (350-370 mm × 79-92 mm). Images were successfully reconstructed with 3D through-time radial GRAPPA, and interframe respiratory motion was compensated by using an algorithm developed to automatically use images from multiple points of enhancement as references for registration. Quantitative pharmacokinetic analysis was performed using a separable dual-compartment model. Region-of-interest (ROI) pharmacokinetic analysis provided estimates (mean (SD)) of quantitative renal parameters after a half dose: 218.1 (57.1) mL/min per 100 mL; plasma mean transit time, 4.8 (2.2) seconds; renal filtration, 28.7 (10.0) mL/min per 100 mL; and tubular mean transit time, 131.1 (60.2) seconds in 10 kidneys. The ROI pharmacokinetic analysis provided estimates (mean (SD)) of quantitative renal parameters after a quarter dose: 218.1 (57.1) mL/min per 100 mL; plasma mean transit time, 4.8 (2.2) seconds; renal filtration, 28.7 (10.0) mL/min per 100 mL; and tubular mean transit time

  14. Estimation of Response Functions Based on Variational Bayes Algorithm in Dynamic Images Sequences

    PubMed Central

    2016-01-01

    We proposed a nonparametric Bayesian model based on variational Bayes algorithm to estimate the response functions in dynamic medical imaging. In dynamic renal scintigraphy, the impulse response or retention functions are rather complicated and finding a suitable parametric form is problematic. In this paper, we estimated the response functions using nonparametric Bayesian priors. These priors were designed to favor desirable properties of the functions, such as sparsity or smoothness. These assumptions were used within hierarchical priors of the variational Bayes algorithm. We performed our algorithm on the real online dataset of dynamic renal scintigraphy. The results demonstrated that this algorithm improved the estimation of response functions with nonparametric priors. PMID:27631007

  15. Distinguishing splenosis from renal masses using ferumoxide-enhanced magnetic resonance imaging.

    PubMed

    Berman, Adam J; Zahalsky, Michael P; Okon, Stephen A; Wagner, Joseph R

    2003-10-01

    A 43-year-old man with a history of splenectomy was found to have a solid renal mass on computed tomography. Magnetic resonance imaging with ferumoxide characterized this mass as ectopic splenic tissue and nephrectomy was avoided.

  16. High-NaCl diet impairs dynamic renal blood flow autoregulation in rats with adenine-induced chronic renal failure.

    PubMed

    Saeed, Aso; DiBona, Gerald F; Grimberg, Elisabeth; Nguy, Lisa; Mikkelsen, Minne Line Nedergaard; Marcussen, Niels; Guron, Gregor

    2014-03-15

    This study examined the effects of 2 wk of high-NaCl diet on kidney function and dynamic renal blood flow autoregulation (RBFA) in rats with adenine-induced chronic renal failure (ACRF). Male Sprague-Dawley rats received either chow containing adenine or were pair-fed an identical diet without adenine (controls). After 10 wk, rats were randomized to either remain on the same diet (0.6% NaCl) or to be switched to high 4% NaCl chow. Two weeks after randomization, renal clearance experiments were performed under isoflurane anesthesia and dynamic RBFA, baroreflex sensitivity (BRS), systolic arterial pressure variability (SAPV), and heart rate variability were assessed by spectral analytical techniques. Rats with ACRF showed marked reductions in glomerular filtration rate and renal blood flow (RBF), whereas mean arterial pressure and SAPV were significantly elevated. In addition, spontaneous BRS was reduced by ∼50% in ACRF animals. High-NaCl diet significantly increased transfer function fractional gain values between arterial pressure and RBF in the frequency range of the myogenic response (0.06-0.09 Hz) only in ACRF animals (0.3 ± 4.0 vs. -4.4 ± 3.8 dB; P < 0.05). Similarly, a high-NaCl diet significantly increased SAPV in the low-frequency range only in ACRF animals. To conclude, a 2-wk period of a high-NaCl diet in ACRF rats significantly impaired dynamic RBFA in the frequency range of the myogenic response and increased SAPV in the low-frequency range. These abnormalities may increase the susceptibility to hypertensive end-organ injury and progressive renal failure by facilitating pressure transmission to the microvasculature.

  17. Renal nerves dynamically regulate renal blood flow in conscious, healthy rabbits

    PubMed Central

    Schiller, Alicia M.; Pellegrino, Peter R.

    2015-01-01

    Despite significant clinical interest in renal denervation as a therapy, the role of the renal nerves in the physiological regulation of renal blood flow (RBF) remains debated. We hypothesized that the renal nerves physiologically regulate beat-to-beat RBF variability (RBFV). This was tested in chronically instrumented, healthy rabbits that underwent either bilateral surgical renal denervation (DDNx) or a sham denervation procedure (INV). Artifact-free segments of RBF and arterial pressure (AP) from calmly resting, conscious rabbits were used to extract RBFV and AP variability for time-domain, frequency-domain, and nonlinear analysis. Whereas steady-state measures of RBF, AP, and heart rate did not statistically differ between groups, DDNx rabbits had greater RBFV than INV rabbits. AP-RBF transfer function analysis showed greater admittance gain in DDNx rabbits than in INV rabbits, particularly in the low-frequency (LF) range where systemic sympathetic vasomotion gives rise to AP oscillations. In the LF range, INV rabbits exhibited a negative AP-RBF phase shift and low coherence, consistent with the presence of an active control system. Neither of these features were present in the LF range of DDNx rabbits, which showed no phase shift and high coherence, consistent with a passive, Ohm's law pressure-flow relationship. Renal denervation did not significantly affect nonlinear RBFV measures of chaos, self-affinity, or complexity, nor did it significantly affect glomerular filtration rate or extracellular fluid volume. Cumulatively, these data suggest that the renal nerves mediate LF renal sympathetic vasomotion, which buffers RBF from LF AP oscillations in conscious, healthy rabbits. PMID:26538235

  18. Renal nerves dynamically regulate renal blood flow in conscious, healthy rabbits.

    PubMed

    Schiller, Alicia M; Pellegrino, Peter R; Zucker, Irving H

    2016-01-15

    Despite significant clinical interest in renal denervation as a therapy, the role of the renal nerves in the physiological regulation of renal blood flow (RBF) remains debated. We hypothesized that the renal nerves physiologically regulate beat-to-beat RBF variability (RBFV). This was tested in chronically instrumented, healthy rabbits that underwent either bilateral surgical renal denervation (DDNx) or a sham denervation procedure (INV). Artifact-free segments of RBF and arterial pressure (AP) from calmly resting, conscious rabbits were used to extract RBFV and AP variability for time-domain, frequency-domain, and nonlinear analysis. Whereas steady-state measures of RBF, AP, and heart rate did not statistically differ between groups, DDNx rabbits had greater RBFV than INV rabbits. AP-RBF transfer function analysis showed greater admittance gain in DDNx rabbits than in INV rabbits, particularly in the low-frequency (LF) range where systemic sympathetic vasomotion gives rise to AP oscillations. In the LF range, INV rabbits exhibited a negative AP-RBF phase shift and low coherence, consistent with the presence of an active control system. Neither of these features were present in the LF range of DDNx rabbits, which showed no phase shift and high coherence, consistent with a passive, Ohm's law pressure-flow relationship. Renal denervation did not significantly affect nonlinear RBFV measures of chaos, self-affinity, or complexity, nor did it significantly affect glomerular filtration rate or extracellular fluid volume. Cumulatively, these data suggest that the renal nerves mediate LF renal sympathetic vasomotion, which buffers RBF from LF AP oscillations in conscious, healthy rabbits.

  19. Complications of sporadic, hereditary, and acquired renal cysts: cross-sectional imaging findings.

    PubMed

    Tonolini, Massimo; Rigiroli, Francesca; Villa, Federica; Bianco, Roberto

    2014-01-01

    Commonly encountered in the general adult and elderly population, in most cases simple renal cysts are confidently diagnosed on imaging studies and do not require further workup or treatment. However, large or growing renal cysts sometimes cause symptoms or signs such as hypertension, palpable mass, flank or abdominal pain, obstructive uropathy, and hematuria, which may indicate the need for minimally invasive percutaneous or laparoscopic treatment. Furthermore, severe complications such as cystic hemorrhage, rupture, or superinfection may occur, particularly in patients with polycystic renal disorders, either hereditary (namely adult polycystic kidney diseases) or acquired in chronic renal failure. This pictorial essay reviews and discusses the cross-sectional imaging appearances of symptomatic and complicated sporadic, hereditary, and acquired renal cysts. Early cross-sectional imaging with multidetector computed tomography or magnetic resonance imaging or both, including contrast enhancement unless contraindicated by renal dysfunction, is warranted to investigate clinical and laboratory signs suggesting retroperitoneal hemorrhage or infection in patients with pre-existent renal cysts, particularly if large, multiple, or hereditary. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Nano-sized Contrast Agents to Non-Invasively Detect Renal Inflammation by Magnetic Resonance Imaging

    PubMed Central

    Thurman, Joshua M.; Serkova, Natalie J.

    2013-01-01

    Several molecular imaging methods have been developed that employ nano-sized contrast agents to detect markers of inflammation within tissues. Renal inflammation contributes to disease progression in a wide range of autoimmune and inflammatory diseases, and a biopsy is currently the only method of definitively diagnosing active renal inflammation. However, the development of new molecular imaging methods that employ contrast agents capable of detecting particular immune cells or protein biomarkers will allow clinicians to evaluate inflammation throughout the kidneys, and to assess a patient's response to immunomodulatory drugs. These imaging tools will improve our ability to validate new therapies and to optimize the treatment of individual patients with existing therapies. This review describes the clinical need for new methods of monitoring renal inflammation, and recent advances in the development of nano-sized contrast agents for detection of inflammatory markers of renal disease. PMID:24206601

  1. Histological Image Feature Mining Reveals Emergent Diagnostic Properties for Renal Cancer.

    PubMed

    Kothari, Sonal; Phan, John H; Young, Andrew N; Wang, May D

    2011-11-01

    Computer-aided histological image classification systems are important for making objective and timely cancer diagnostic decisions. These systems use combinations of image features that quantify a variety of image properties. Because researchers tend to validate their diagnostic systems on specific cancer endpoints, it is difficult to predict which image features will perform well given a new cancer endpoint. In this paper, we define a comprehensive set of common image features (consisting of 12 distinct feature subsets) that quantify a variety of image properties. We use a data-mining approach to determine which feature subsets and image properties emerge as part of an "optimal" diagnostic model when applied to specific cancer endpoints. Our goal is to assess the performance of such comprehensive image feature sets for application to a wide variety of diagnostic problems. We perform this study on 12 endpoints including 6 renal tumor subtype endpoints and 6 renal cancer grade endpoints. Keywords-histology, image mining, computer-aided diagnosis.

  2. Prognostic value of intravenous dipyridamole thallium imaging in patients with diabetes mellitus considered for renal transplantation

    SciTech Connect

    Camp, A.D.; Garvin, P.J.; Hoff, J.; Marsh, J.; Byers, S.L.; Chaitman, B.R. )

    1990-06-15

    Patients with diabetes and end-stage renal failure are known to have a high risk for cardiac morbidity and mortality associated with renal transplantation. The most efficient method to determine preoperative cardiac risk has not been established. To determine the effectiveness of intravenous dipyridamole thallium imaging in predicting cardiac events, 40 diabetic renal transplant candidates were studied preoperatively in a prospective trial. The study group consisted of 40 patients whose average age was 42 years (range 27 to 64); 34 (85%) were hypertensive and 21 (53%) were cigarette smokers. Cardiac history included chest pain in 6 patients and prior myocardial infarction in 3 patients. Dipyridamole thallium imaging showed reversible defects in 9 patients, fixed defects in 8 patients and normal scans in 23 patients. Dipyridamole thallium imaging was performed using 0.56 mg/kg of dipyridamole infused intravenously over 4 minutes. Cardiac events occurred only in patients with reversible thallium defects, of which there were 6. Of these 6 patients, 3 had cardiac events before transplantation and 3 had them in the early postoperative phase (within 6 weeks of surgery). Of 21 patients who underwent renal transplantation, 3 had cardiac events within 6 weeks of transplantation. The average duration of follow-up was 11 months (range 1 to 21). Thus, dipyridamole thallium imaging is an effective method of identifying renal transplant candidates likely to develop cardiac complications. Routine coronary angiography may not be necessary to screen all renal transplant candidates for coronary artery disease before surgery.

  3. Angio-computed tomography and dynamic computed tomography in staging of renal cell carcinoma

    SciTech Connect

    Lang, E.K.

    1984-04-01

    Dynamic computed tomography and angio-tomography combine criteria generated by CT with those of angiography and are advocated by the author to improve staging of renal cell carcinoma. Dynamic CT was performed in 29 patients and angio-CT in 12 patients in this group. Rapid acquisition of data permits generation of a CT section in intervals of 1 to 6 seconds, which in turn reflects arterial capillary, and venous transit of contrast medium through tissue. The propensity for dense enhancement of renal cell carcinoma makes possible positive identification of tumor elements. This feature proved accurate for the assessment of local extension of renal neoplasms in all 29 patients, involvement of the renal vein by tumor in 9/10, involvement of the inferior vena cava by tumor in 6/6, and involvement of regional nodes by tumor in 6/8.

  4. Geocoronal Imaging with Dynamics Explorer

    NASA Astrophysics Data System (ADS)

    Rairden, Richard Louis

    The ultraviolet photometer of the University of Iowa spin-scan auroral imaging instrumentation on board the Dynamics Explorer-1 satellite has returned numerous images of the geocorona from altitudes of 570 km to 23,300 km. The geocoronal emissions viewed arise from the resonant scattering of solar Lyman-alpha radiation by the neutral hydrogen atoms which make up the earth's tenuous exosphere. This hydrogen exosphere extends from (TURN)500 km to greater than 80,000 km altitude, wherein the atoms travel on effectively collisionless trajectories loosely bound by the earth's gravity. In this thesis the geocoronal observations from 1981 through 1984 are compared to a spherically symmetric isothermal Chamberlain model of the exospheric density distribution. Model parameters are varied to obtain an acceptable fit. The radiative transfer equation is solved numerically for this multiple-scattering problem. Stellar intensities are monitored for inflight calibration of the DE-1 instrument. The solar Ly (alpha) flux is estimated through concurrent measurements made by the SME satellite, supplemented by published values of ground-observable solar indices. Extraterrestrial background intensities are adopted from earlier OGO-5 high-altitude measurements. The optimum fit utilizes a Chamberlain model of temperature T = 1050 K and exobase density n(,c) = 44,000 atoms cm('-3). The exobase is taken as r(,c) = 1.08 R(,E) (500 km altitude), and a satellite critical level of r(,cs) = 3.0 r(,c) is adopted. This model compares well with the DE-1 observations over the entire three years of data studied. It is concluded that the exospheric temperature does not change appreciably during this period. A definitive statement on long-term changes in the required exobase density is not made due to uncertainty in the degradation of instrument sensitivity with time. A readily observable departure from spherical symmetry is the geotail, an enhancement in the antisunward column density. Other

  5. Advantage of indium-111 leukocytes over ultrasound in imaging an infected renal cyst

    SciTech Connect

    Fortner, A.; Taylor, A. Jr.; Alazraki, N.; Datz, F.L.

    1986-07-01

    Indium-111-labeled leukocyte scanning is a highly sensitive and specific method of detecting abscesses. This report describes a patient with polycystic kidneys and a single infected cyst. Ultrasound could not determine which cyst was infected, but the infected cyst could be localized by (/sup 111/In)leukocyte imaging in conjunction with a (/sup 99m/Tc)DMSA renal scan. The two radionuclide studies were used to identify an infected renal cyst and direct ultrasound guided aspiration.

  6. Image correlation spectroscopy to define membrane dynamics.

    PubMed

    Bonor, Jeremy; Nohe, Anja

    2010-01-01

    Fluorescent imaging techniques are powerful tools that aid in studying protein dynamics and membrane domains and allow for the visualization and data collection of such structures as caveolae and clathrin-coated pits, key players in the regulation of cell communication and signaling. The family of image correlation spectroscopy (FICS) provides a unique way to determine details about aggregation, clustering, and dynamics of proteins on the plasma membrane. FICS consists of many imaging techniques which we will focus on including image correlation spectroscopy, image cross-correlation spectroscopy and dynamic image correlation spectroscopy. Image correlation spectroscopy is a tool used to calculate the cluster density, which is the average number of clusters per unit area along with data to determine the degree of aggregation of plasma membrane proteins. Image cross-correlation spectroscopy measures the colocalization of proteins of interest. Dynamic image correlation spectroscopy can be used to analyze protein aggregate dynamics on the cell surface during live-cell imaging in the millisecond to second range.

  7. Stepwise algorithm using computed tomography and magnetic resonance imaging for diagnosis of fat-poor angiomyolipoma in small renal masses: Development and external validation.

    PubMed

    Tanaka, Hajime; Fujii, Yasuhisa; Tanaka, Hiroshi; Ishioka, Junichiro; Matsuoka, Yoh; Saito, Kazutaka; Uehara, Sho; Numao, Noboru; Yuasa, Takeshi; Yamamoto, Shinya; Masuda, Hitoshi; Yonese, Junji; Kihara, Kazunori

    2017-07-01

    To develop a stepwise diagnostic algorithm for fat-poor angiomyolipoma in small renal masses. Two cohorts of small renal masses <4 cm without an apparent fat component that was pathologically diagnosed were included: 153 cases (18 fat-poor angiomyolipomas/135 renal cell carcinomas) for model development and 71 cases (seven fat-poor angiomyolipomas/59 renal cell carcinomas/5 oncocytomas) for validation. Dynamic contrast-enhanced computed tomography, magnetic resonance imaging and clinical findings were analyzed. Based on multivariate analysis, we developed two prediction models for fat-poor angiomyolipoma, the computed tomography model and the computed tomography + magnetic resonance imaging model, and a stepwise algorithm that proposes the sequential use of computed tomography and magnetic resonance imaging. The computed tomography model, which was composed of female aged <50 years, high attenuation on unenhanced computed tomography, less enhancement than the normal renal cortex and homogeneity in the corticomedullary phase, differentiated tumors with none of the factors as the low angiomyolipoma-probability group, and the others were candidates for the computed tomography + magnetic resonance imaging model. The computed tomography + magnetic resonance imaging model, consisting of the first three factors of the computed tomography model, low signal intensity and absence of pseudocapsule on T2-weighted magnetic resonance imaging, re-stratified the tumors into low, intermediate and high angiomyolipoma-probability groups. The incidence of fat-poor angiomyolipoma in each group was 0%, 26% and 93%, respectively (area under the curve 0.981). External validation by two readers showed a high area under the curve (0.912 and 0.924) for each. The interobserver agreement was good (kappa score 0.77). The present algorithm differentiates fat-poor angiomyolipoma in small renal masses with high accuracy by adding magnetic resonance imaging to computed tomography in

  8. Groupwise Image Registration Guided by a Dynamic Digraph of Images.

    PubMed

    Tang, Zhenyu; Fan, Yong

    2016-04-01

    For groupwise image registration, graph theoretic methods have been adopted for discovering the manifold of images to be registered so that accurate registration of images to a group center image can be achieved by aligning similar images that are linked by the shortest graph paths. However, the image similarity measures adopted to build a graph of images in the extant methods are essentially pairwise measures, not effective for capturing the groupwise similarity among multiple images. To overcome this problem, we present a groupwise image similarity measure that is built on sparse coding for characterizing image similarity among all input images and build a directed graph (digraph) of images so that similar images are connected by the shortest paths of the digraph. Following the shortest paths determined according to the digraph, images are registered to a group center image in an iterative manner by decomposing a large anatomical deformation field required to register an image to the group center image into a series of small ones between similar images. During the iterative image registration, the digraph of images evolves dynamically at each iteration step to pursue an accurate estimation of the image manifold. Moreover, an adaptive dictionary strategy is adopted in the groupwise image similarity measure to ensure fast convergence of the iterative registration procedure. The proposed method has been validated based on both simulated and real brain images, and experiment results have demonstrated that our method was more effective for learning the manifold of input images and achieved higher registration accuracy than state-of-the-art groupwise image registration methods.

  9. Detection of early changes in renal function using 99mTc-MAG3 imaging in a murine model of ischemia-reperfusion injury.

    PubMed

    Roberts, John; Chen, Bo; Curtis, Lisa M; Agarwal, Anupam; Sanders, Paul W; Zinn, Kurt R

    2007-10-01

    Accurate determination of renal function in mice is a major impediment to the use of murine models in acute kidney injury. The purpose of this study was to determine whether early changes in renal function could be detected using dynamic gamma camera imaging in a mouse model of ischemia-reperfusion (I/R) injury. C57BL/6 mice (n = 5/group) underwent a right nephrectomy, followed by either 30 min of I/R injury or sham surgery of the remaining kidney. Dynamic renal studies (21 min, 10 s/frame) were conducted before surgery (baseline) and at 5, 24, and 48 h by injection of (99m)Tc-mercaptoacetyltriglycine (MAG3; approximately 1.0 mCi/mouse) via the tail vein. The percentage of injected dose (%ID) in the kidney was calculated for each 10-s interval after MAG3 injection, using standard region of interest analyses. A defect in renal function in I/R-treated mice was detected as early as 5 h after surgery compared with sham-treated mice, identified by the increased %ID (at peak) in the I/R-treated kidneys at 100 s (P < 0.01) that remained significantly higher than sham-treated mice for the duration of the scan until 600 s (P < 0.05). At 48 h, the renal scan demonstrated functional renal recovery of the I/R mice and was comparable to sham-treated mice. Our study shows that using dynamic imaging, renal dysfunction can be detected and quantified reliably as early as 5 h after I/R insult, allowing for evaluation of early treatment interventions.

  10. Renal uptake of Tl-201 in hypertensive patients undergoing myocardial perfusion imaging

    SciTech Connect

    Hurwitz, G.A.; Mattar, A.G.; Bhargava, R.; Driedger, A.A.; Hogendoorn, P.; Wesolowski, C.A. )

    1990-02-01

    The detection of renovascular disease (RVD) has particular relevance in hypertensive patients (HP) who have symptoms of target organ damage. To evaluate the possibility of RVD in HP undergoing myocardial perfusion scintigraphy for chest pain symptoms, posterior renal images were obtained at 1-3 hours after Tl-201 injection. Analog and computer images were obtained for 5 minutes in 45 HP; 12 patients with no history of hypertension or renal disease served as normal controls. For qualitative analysis, images were coded and read by three observers as to symmetry of renal uptake. Differential renal uptake of Tl-201 (DRU) was quantitated on computer images. In normal controls, uptake was agreed on as symmetric. In HP, 6 patients had marked asymmetry of DRU and 4 had possibly significant asymmetry; 2 had decreased uptake in both kidneys suggesting bilateral RVD or nephrosclerosis. Objective correlation with DRU was obtained in 10 HP who had contrast angiography, confirming 4 cases of unilateral RVD and 2 of bilateral RVD. Thirteen patients also had renography with Tc-99m DTPA; differential renal function by this modality correlated well with DRU of Tl-201 (r = 0.98). Thus, DRU of Tl-201 can be used as a supplement to myocardial scintigraphy to identify HP who require further evaluation and treatment of RVD.

  11. Renal tubular receptor imaging with iodine-131-labeled peanut lectin: pharmacokinetics and renal clearance mechanism in animals

    SciTech Connect

    Boniface, G.R.; Suresh, M.R.; Willans, D.J.; Tam, Y.K.; Shysh, A.; Longenecker, B.M.; Noujaim, A.A.

    1986-05-01

    Intravenously administered peanut lectin (PNA), iodinated with /sup 131/I ((/sup 131/I)PNA), is rapidly cleared from the plasma by the kidneys in dogs (clearance (total body) = 17.52 +/- 8.74 ml/min). Dynamic gamma camera renal scintigraphy demonstrated renal accumulation and excretion phases of the (/sup 131/I)PNA renogram in dogs and rabbits (% injection dose-at-peak = 21.8 +/- 3.3% and 19.6 +/- 4.3%, time-to-peak = 44.6 +/- 4.8 min and 37.2 +/- 6.9 min, respectively). Immunoperoxidase staining of kidney sections, following i.v. administered PNA, demonstrated predominant accumulation by the proximal tubules of mice, rabbits, and dogs. The basement membrane was intensely stained at early times p.i. while intracellular and luminal PNA was evident within 1 hr. Urine analysis confirmed the presence of intact (/sup 131/I)PNA in the bladder contents, while protein degradation products, and a small percentage of the free iodide (less than 5%) were noted within 1 hr p.i. The relative proportion of free iodide increased at later times p.i. (greater than 6 hr). A receptor mediated excretion mechanism is proposed for the clearance of PNA and may be useful for the study of renal tubular function.

  12. Dynamic Programming Based Segmentation in Biomedical Imaging.

    PubMed

    Ungru, Kathrin; Jiang, Xiaoyi

    2017-01-01

    Many applications in biomedical imaging have a demand on automatic detection of lines, contours, or boundaries of bones, organs, vessels, and cells. Aim is to support expert decisions in interactive applications or to include it as part of a processing pipeline for automatic image analysis. Biomedical images often suffer from noisy data and fuzzy edges. Therefore, there is a need for robust methods for contour and line detection. Dynamic programming is a popular technique that satisfies these requirements in many ways. This work gives a brief overview over approaches and applications that utilize dynamic programming to solve problems in the challenging field of biomedical imaging.

  13. [Functional magnetic resonance imaging for evaluation of radiation-induced renal damage].

    PubMed

    Haneder, S; Boda-Heggemann, J; Schoenberg, S O; Michaely, H J

    2012-03-01

    The diagnosis of radiation-induced (especially chronic) renal alterations/damage is difficult and currently relies primarily on clinical evaluation. The importance of renal diagnostic evaluation will increase continuously due to the increasing number of long-term survivors after radiotherapy. This article evaluates the potentia diagnostic contribution of magnetic resonance (MR) imaging with a focus on functional MRI. The following functional MRI approaches are briefly presented and evaluated: blood oxygenation level-dependent imaging (BOLD), diffusion-weighted imaging (DWI) or diffusion tensor imaging (DTI), MR perfusion measurements and (23)Na imaging. In summary, only DWI and contrast-enhanced MR perfusion currently seem to be suitable approaches for a broader, clinical implementation. However, up to now valid data from larger patient studies are lacking for both techniques in regard to radiation-induced renal alterations. The BOLD and (23)Na imaging procedures have a huge potential but are currently neither sufficiently evaluated with regard to radiation-induced renal alterations nor technically simple and reliable for implementation into the clinical routine.

  14. Computer-Aided Detection of Exophytic Renal Lesions on Non-Contrast CT Images

    PubMed Central

    Liu, Jianfei; Wang, Shijun; Linguraru, Marius George; Yao, Jianhua; Summers, Ronald M.

    2014-01-01

    Renal lesions are important extracolonic findings on computed tomographic colonography (CTC). They are difficult to detect on non-contrast CTC images due to low image contrast with surrounding objects. In this paper, we developed a novel computer-aided diagnosis system to detect a subset of renal lesions, exophytic lesions, by 1) exploiting efficient belief propagation to segment kidneys, 2) establishing an intrinsic manifold diffusion on kidney surface, 3) searching for potential lesion-caused protrusions with local maximum diffusion response, and 4) exploring novel shape descriptors, including multi-scale diffusion response, with machine learning to classify exophytic renal lesions. Experimental results on the validation dataset with 167 patients revealed that manifold diffusion significantly outperformed conventional shape features (p < 1e − 3) and resulted in 95% sensitivity with 15 false positives per patient for detecting exophytic renal lesions. Five-fold cross-validation also demonstrated that our method could stably detect exophytic renal lesions. These encouraging results demonstrated that manifold diffusion is a key means to enable accurate computer-aided diagnosis of renal lesions. PMID:25189363

  15. Computed tomography and magnetic resonance imaging of maxillofacial lesions in renal osteodystrophy.

    PubMed

    Abdel Razek, Ahmed Abdel Khalek

    2014-07-01

    This study aims to describe the computed tomography (CT) and magnetic resonance (MR) imaging appearance of maxillofacial lesions in renal osteodystrophy. We retrospectively reviewed the CT and MR imaging of maxillofacial region in 9 patients (6 females and 3 males with mean age of 31 yr) with renal osteodystrophy. They presented with facial swelling (n = 6), facial disfigurement (n = 2), and oral cavity mass (n = 1). They underwent CT and MR imaging of the maxillofacial region. Brown tumors (n = 6) were seen in the mandible (n = 4) and maxilla (n = 2). They appeared as mixed lytic and sclerotic (n = 4) and sclerotic (n = 2) lesions at CT. The lesions appeared as hypointense at T1-weighted images and of mixed signal intensity at T2-weighted images with intense contrast enhancement (n = 6). Uremic leontiasis ossea (n = 2) appeared at CT as diffuse hyperostosis with protruded maxilla and obliterated sinus. At MR imaging, there was expansion of the maxilla with obliteration of the maxillary sinuses and protrusion of the mandible. The lesion exhibited low signal intensity at T1-weighed images. At T2-weighted images, the lesion showed low signal intensity with small hyperintense lesions. Dystrophic calcification (n = 2) was seen in the parotid and the check. We concluded that CT and MR imaging are helpful for diagnosis and treatment planning of maxillofacial lesions of patients with renal osteodystrophy.

  16. Technetium-99m pyrophosphate imaging in acute renal failure associated with nontraumatic rhabdomyolysis

    SciTech Connect

    Patel, R.; Mishkin, F.S.

    1986-10-01

    Technetium-99m pyrophosphate (Tc-PYP) imaging was performed in five patients with acute renal failure associated with nontraumatic rhabdomyolysis. Four patients had phencyclidine intoxication and one had viral pneumonia. During the acute phase, marked uptake of pyrophosphate was seen in all patients in several muscle groups, but always in the thigh adductors. The results show that phencyclidine intoxication can result in diffuse muscle uptake of Tc-PYP without overt evidence of muscle injury. Tc-PYP imaging may provide a clue to the cause of acute renal failure in patients with suspected rhabdomyolysis in whom elevations of serum creatine phosphokinase concentrations are equivocal.

  17. Magnetic Resonance Imaging (MRI) Analysis of Ischemia/Reperfusion in Experimental Acute Renal Injury.

    PubMed

    Pohlmann, Andreas; Arakelyan, Karen; Seeliger, Erdmann; Niendorf, Thoralf

    2016-01-01

    Imbalance between renal oxygen delivery and demand in the first hours after reperfusion is suggested to be decisive in the pathophysiological chain of events leading to ischemia-induced acute kidney injury. Here we describe blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) for continuous monitoring of the deoxyhemoglobin-sensitive MR parameter T 2* in the renal cortex, outer medulla, and inner medulla of rats throughout renal ischemia/reperfusion (I/R). Changes during I/R are benchmarked against the effects of variations in the fraction of inspired oxygen (hypoxia, hyperoxia). This method may be useful for investigating renal blood oxygenation of rats in vivo under various experimental (patho)physiological conditions.

  18. High Dynamic Range Imaging Using Multiple Exposures

    NASA Astrophysics Data System (ADS)

    Hou, Xinglin; Luo, Haibo; Zhou, Peipei; Zhou, Wei

    2017-06-01

    It is challenging to capture a high-dynamic range (HDR) scene using a low-dynamic range (LDR) camera. This paper presents an approach for improving the dynamic range of cameras by using multiple exposure images of same scene taken under different exposure times. First, the camera response function (CRF) is recovered by solving a high-order polynomial in which only the ratios of the exposures are used. Then, the HDR radiance image is reconstructed by weighted summation of the each radiance maps. After that, a novel local tone mapping (TM) operator is proposed for the display of the HDR radiance image. By solving the high-order polynomial, the CRF can be recovered quickly and easily. Taken the local image feature and characteristic of histogram statics into consideration, the proposed TM operator could preserve the local details efficiently. Experimental result demonstrates the effectiveness of our method. By comparison, the method outperforms other methods in terms of imaging quality.

  19. Modelling of the dynamic relationship between arterial pressure, renal sympathetic nerve activity and renal blood flow in conscious rabbits.

    PubMed

    Berger, C S; Malpas, S C

    1998-12-01

    A linear autoregressive/moving-average model was developed to describe the dynamic relationship between mean arterial pressure (MAP), renal sympathetic nerve activity (SNA) and renal blood flow (RBF) in conscious rabbits. The RBF and SNA to the same kidney were measured under resting conditions in a group of eight rabbits. Spectral analysis of the data sampled at 0.4 Hz showed that the low-pass bandwidth of the signal power for RBF was approximately 0. 05 Hz. An autoregressive/moving-average model with an exogenous input (ARMAX) was then derived (using the iterative Gauss-Newton algorithm provided by the MATLAB identification Toolbox), with MAP and SNA as inputs and RBF as output, to model the low-frequency fluctuations. The model step responses of RBF to changes in SNA and arterial pressure indicated an overdamped response with a settling time that was usually less than 2 s. Calculated residuals from the model indicated that 79 5 % (mean s.d., averaged over eight independent experiments) of the variation in RBF could be accounted for by the variations in arterial pressure and SNA. Two additional single-input models for each of the inputs were similarly obtained and showed conclusively that changes in RBF, in the conscious resting rabbit, are a function of both SNA and MAP and that the SNA signal has the predominant effect. These results indicate a strong reliance on SNA for the dynamic regulation of RBF. Such information is likely to be important in understanding the diminished renal function that occurs in a variety of disease conditions in which overactivity of the sympathetic nervous system occurs.

  20. 320-row CT renal perfusion imaging in patients with aortic dissection: A preliminary study

    PubMed Central

    Liu, Dongting; Liu, Jiayi; Wen, Zhaoying; Li, Yu; Sun, Zhonghua; Xu, Qin; Fan, Zhanming

    2017-01-01

    Objective To investigate the clinical value of renal perfusion imaging in patients with aortic dissection (AD) using 320-row computed tomography (CT), and to determine the relationship between renal CT perfusion imaging and various factors of aortic dissection. Methods Forty-three patients with AD who underwent 320-row CT renal perfusion before operation were prospectively enrolled in this study. Diagnosis of AD was confirmed by transthoracic echocardiography. Blood flow (BF) of bilateral renal perfusion was measured and analyzed. CT perfusion imaging signs of AD in relation to the type of AD, number of entry tears and the false lumen thrombus were observed and compared. Results The BF values of patients with type A AD were significantly lower than those of patients with type B AD (P = 0.004). No significant difference was found in the BF between different numbers of intimal tears (P = 0.288), but BF values were significantly higher in cases with a false lumen without thrombus and renal arteries arising from the true lumen than in those with thrombus (P = 0.036). The BF values measured between the true lumen, false lumen and overriding groups were different (P = 0.02), with the true lumen group having the highest. Also, the difference in BF values between true lumen and false lumen groups was statistically significant (P = 0.016), while no statistical significance was found in the other two groups (P > 0.05). The larger the size of intimal entry tears, the greater the BF values (P = 0.044). Conclusions This study shows a direct correlation between renal CT perfusion changes and AD, with the size, number of intimal tears, different types of AD, different renal artery origins and false lumen thrombosis, significantly affecting the perfusion values. PMID:28182709

  1. Evaluation of Renal Blood Flow and Oxygenation in CKD Using Magnetic Resonance Imaging.

    PubMed

    Khatir, Dinah S; Pedersen, Michael; Jespersen, Bente; Buus, Niels H

    2015-09-01

    Animal studies suggest that progression of chronic kidney disease (CKD) is related to renal hypoxia. With renal blood supply determining oxygen delivery and sodium absorption being the main contributor to oxygen consumption, we describe the relationship between renal oxygenation, renal artery blood flow, and sodium absorption in patients with CKD and healthy controls. Cross-sectional study. 62 stable patients with CKD stages 3 to 4 (mean age, 61±13 [SD] years) and 24 age- and sex-matched controls. CKD versus control status. Renal artery blood flow, tissue oxygenation (relative changes in deoxyhemoglobin concentration of the renal medulla [MR2*] and cortex [CR2*]), and sodium absorption. Renal artery blood flow was determined by phase-contrast magnetic resonance imaging (MRI); MR2* and CR2* were determined by blood oxygen level-dependent MRI. Ultrafiltered and reabsorbed sodium were determined from measured glomerular filtration rate (mGFR) and 24-hour urine collections. mGFR in patients was 37% that of controls (36±15 vs 97±23 mL/min/1.73 m(2); P < 0.001), and reabsorbed sodium was 37% that of controls (6.9 vs 19.1 mol/24 h; P < 0.001). Single-kidney patient renal artery blood flow was 72% that of controls (319 vs 443 mL/min; P < 0.001). Glomerular filtration fraction was 9% in patients and 18% in controls (P < 0.001). Patients and controls had similar CR2* (13.4 vs 13.3 s(-1)) and medullary MR2* (26.4 vs 26.5 s(-1)) values. Linear regression analysis demonstrated no associations between R2* and renal artery blood flow or sodium absorption. Increasing arterial blood oxygen tension by breathing 100% oxygen had very small effects on CR2*, but reduced MR2* in both groups. Only renal artery blood flow was determined and thus regional perfusion could not be related to CR2* or MR2*. In CKD, reductions of mGFR and reabsorbed sodium are more than double that of renal artery blood flow, whereas cortical and medullary oxygenation are within the range of healthy persons

  2. Renal lymphoma imaged by ultrasound and Gallium-67

    SciTech Connect

    Shirkhoda, A.; Staab, E.V.; Mittelstaedt, C.A.

    1980-10-01

    Lymphomatous involvement of the kidneys, usually a secondary process, may be seen as single or multiple sonolucent or weakly echogenic masses on ultrasound. The majority of these patients have a known diagnosis of lymphoma and are being evaluated for change in nodal mass size, flank pain, and/or deteriorating renal function. Occasionally, these masses are discovered on an excretory urogram and are further investigated with ultrasound. The ultrasound findings may be confirmed with gallium scanning. Five such cases are presented along with the ultrasonic and gallium scan findings.

  3. MDCT imaging following nephrectomy for renal cell carcinoma: Protocol optimization and patterns of tumor recurrence

    PubMed Central

    Coquia, Stephanie F; Johnson, Pamela T; Ahmed, Sameer; Fishman, Elliot K

    2013-01-01

    The purpose of this pictorial essay is to review the common and uncommon sites of renal cell carcinoma recurrence throughout the body by examining their appearances on computerized tomography (CT). CT imaging protocols will be discussed. The sites of recurrence have been categorized into 4 groups: chest and mediastinum, abdomen and pelvis, musculoskeletal, and neurological. For each site of recurrence, a representative CT image correlate with discussion is provided. The unique CT appearance of renal cell carcinoma recurrence and how it can be used in lesion detection will be discussed. Renal cell carcinoma recurrences are hypervascular like the primary tumor, which can aid in not only lesion detection but also in some cases, differentiation from other primary tumors. Through CT case review of various sites of recurrence, lesions are shown to be easily seen on arterial phase while sometimes being nearly inconspicuous on venous or delayed phases. Coronal and sagittal reconstructions can also improve diagnostic sensitivity. CT is the most commonly used imaging tool for surveillance of renal cell carcinoma recurrence after nephrectomy. Knowledge of sites of recurrence as well as the utility of arterial phase imaging and multiplanar reconstructions will aid in optimizing detection of disease recurrence. PMID:24349648

  4. Parametric Imaging Of Digital Subtraction Angiography Studies For Renal Transplant Evaluation

    NASA Astrophysics Data System (ADS)

    Gallagher, Joe H.; Meaney, Thomas F.; Flechner, Stuart M.; Novick, Andrew C.; Buonocore, Edward

    1981-11-01

    A noninvasive method for diagnosing acute tubular necrosis and rejection would be an important tool for the management of renal transplant patients. From a sequence of digital subtraction angiographic images acquired after an intravenous injection of radiographic contrast material, the parametric images of the maximum contrast, the time when the maximum contrast is reached, and two times the time at which one half of the maximum contrast is reached are computed. The parametric images of the time when the maximum is reached clearly distinguish normal from abnormal renal function. However, it is the parametric image of two times the time when one half of the maximum is reached which provides some assistance in differentiating acute tubular necrosis from rejection.

  5. Imaging assessment of renal injuries in children and adolescents: CT or ultrasound?

    PubMed

    Amerstorfer, Eva Elisa; Haberlik, Axel; Riccabona, Michael

    2015-03-01

    Since the introduction of the ALARA ("as low as reasonably achievable") concept, ultrasound (US) has been progressively advocated for paediatric diagnostic imaging. This study aimed to analyse the role and accuracy of US in paediatric renal trauma. From 1999 to 2009, the tertiary-care-hospital database was retrospectively evaluated for renal trauma with regards to aetiology, type of injury, diagnostics, management and outcome. Forty-seven patients (29 males, 18 females; median age=14years, range 1-17 years) were identified. US was initially applied in 45 patients with correct results in 86.6%. Computed tomography (CT) was performed in 16 patients in the acute trauma setting - complementary to US in 14 cases, with a diagnostic accuracy of 93%. Most renal injuries were grade I° (n=30), followed by grade III° (n=8), IV° (n=5), and II°/V° (n=2 each). All patients were initially managed conservatively and followed by US. Clinical deterioration necessitated surgery in four patients (2 nephrectomies, 1 partial nephrectomy, 1 urinoma drainage). The outcome was generally favourable with a renal preservation rate of 95%. With respect to the ALARA principle, US can be safely and reliably applied as the first-line diagnostic imaging technique and for follow-up for suspected traumatic paediatric renal injuries. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Optical Imaging with Dynamic Contrast Agents

    PubMed Central

    Wei, Qingshan; Wei, Alexander

    2011-01-01

    Biological imaging applications often employ molecular probes or nanoparticles for enhanced contrast. However, resolution and detection are still often limited by the intrinsic heterogeneity of the Isample, which can produce high levels of background that obscure the signals of interest. In this article we describe approaches to overcome this obstacle based on the concept of dynamic contrast, a strategy for elucidating signals by the suppression or removal of background noise. Dynamic contrast mechanisms can greatly reduce the loading requirement of contrast agents, and may be especially useful for single-probe imaging. Dynamic contrast modalities are also platform-independent, and can enhance the performance of sophisticated biomedical imaging systems or simple optical microscopes alike. Dynamic contrast is performed in two stages: i) a signal modulation scheme to introduce time-dependent changes in amplitude or phase, and ii) a demodulation step for signal recovery. Optical signals can be coupled with magnetic nanoparticles, photoswitchable probes, or plasmon-resonant nanostructures for modulation by magnetomotive, photonic, or photothermal mechanisms respectively. With respect to image demodulation, many of the strategies developed for signal processing in electronics and communication technologies can also be applied toward the editing of digital images. The image processing step can be as simple as differential imaging, or may involve multiple reference points for deconvolution using cross-correlation algorithms. Periodic signals are particularly amenable to image demodulation strategies based on Fourier transform; the contrast of the demodulated signal increases with acquisition time, and modulation frequencies in the kHz range are possible. Dynamic contrast is an emerging topic with considerable room for development, both with respect to molecular or nanoscale probes for signal modulation, and also to methods for more efficient image processing and editing

  7. Optical imaging with dynamic contrast agents.

    PubMed

    Wei, Qingshan; Wei, Alexander

    2011-01-24

    Biological imaging applications often employ molecular probes or nanoparticles for enhanced contrast. However, resolution and detection are still often limited by the intrinsic heterogeneity of the sample, which can produce high levels of background that obscure the signals of interest. Herein, we describe approaches to overcome this obstacle based on the concept of dynamic contrast: a strategy for elucidating signals by the suppression or removal of background noise. Dynamic contrast mechanisms can greatly reduce the loading requirement of contrast agents, and may be especially useful for single-probe imaging. Dynamic contrast modalities are also platform-independent, and can enhance the performance of sophisticated biomedical imaging systems or simple optical microscopes alike. Dynamic contrast is performed in two stages: 1) a signal modulation scheme to introduce time-dependent changes in amplitude or phase, and 2) a demodulation step for signal recovery. Optical signals can be coupled with magnetic nanoparticles, photoswitchable probes, or plasmon-resonant nanostructures for modulation by magnetomotive, photonic, or photothermal mechanisms, respectively. With respect to image demodulation, many of the strategies developed for signal processing in electronics and communication technologies can also be applied toward the editing of digital images. The image-processing step can be as simple as differential imaging, or may involve multiple reference points for deconvolution by using cross-correlation algorithms. Periodic signals are particularly amenable to image demodulation strategies based on Fourier transform; the contrast of the demodulated signal increases with acquisition time, and modulation frequencies in the kHz range are possible. Dynamic contrast is an emerging topic with considerable room for development, both with respect to molecular or nanoscale probes for signal modulation, and also to methods for more efficient image processing and editing

  8. Tips and tricks for a safe and effective image-guided percutaneous renal tumour ablation.

    PubMed

    Mauri, Giovanni; Nicosia, L; Varano, G M; Bonomo, G; Della Vigna, P; Monfardini, L; Orsi, F

    2017-06-01

    Image-guide thermal ablations are nowadays increasingly used to provide a minimally invasive treatment to patients with renal tumours, with reported good clinical results and low complications rate. Different ablative techniques can be applied, each with some advantages and disadvantages according to the clinical situation. Moreover, percutaneous ablation of renal tumours might be complex in cases where there is limited access for image guidance or a close proximity to critical structures, which can be unintentionally injured during treatment. In the present paper we offer an overview of the most commonly used ablative techniques and of the most important manoeuvres that can be applied to enhance the safety and effectiveness of percutaneous image-guided renal ablation. Emphasis is given to the different technical aspects of cryoablation, radiofrequency ablation, and microwave ablation, on the ideal operating room setting, optimal image guidance, application of fusion imaging and virtual navigation, and contrast enhanced ultrasound in the guidance and monitoring of the procedure. Moreover, a series of protective manoeuvre that can be used to avoid damage to surrounding sensitive structures is presented. A selection of cases of image-guided thermal ablation of renal tumours in which the discussed technique were used is presented and illustrated. • Cryoablation, radiofrequency and microwave ablation have different advantages and disadvantages. • US, CT, fusion imaging, and CEUS increase an effective image-guidance. • Different patient positioning and external compression may increase procedure feasibility. • Hydrodissection and gas insufflation are useful to displace surrounding critical structures. • Cold pyeloperfusion can reduce the thermal damage to the collecting system.

  9. Automatic alignment of renal DCE-MRI image series for improvement of quantitative tracer kinetic studies

    NASA Astrophysics Data System (ADS)

    Zikic, Darko; Sourbron, Steven; Feng, Xinxing; Michaely, Henrik J.; Khamene, Ali; Navab, Nassir

    2008-03-01

    Tracer kinetic modeling with dynamic contrast enhanced MRI (DCE-MRI) and the quantification of the kinetic parameters are active fields of research which have the potential to improve the measurement of renal function. However, the strong coronal motion of the kidney in the time series inhibits an accurate assessment of the kinetic parameters. Automatic motion correction is challenging due to the large movement of the kidney and the strong intensity changes caused by the injected bolus. In this work, we improve the quantification results by a template matching motion correction method using a gradient-based similarity measure. Thus, a tedious manual motion correction is replaced by an automatic procedure. The only remaining user interaction is reduced to a selection of a reference slice and a coarse manual segmentation of the kidney in this slice. These steps do not present an overhead to the interaction needed for the assessment of the kinetic parameters. In order to achieve reliable and fast results, we constrain the degrees of freedom for the correction method as far as possible. Furthermore, we compare our method to deformable registration using the same similarity measure. In all our tests, the presented template matching correction was superior to the deformable approach in terms of reliability, leading to more accurate parameter quantification. The evaluation on 10 patient data series with 180-230 images each demonstrate that the quantitative analysis by a two-compartment model can be improved by our method.

  10. A robust method for detection of linear and nonlinear interactions: application to renal blood flow dynamics.

    PubMed

    Feng, Lei; Siu, Kin; Moore, Leon C; Marsh, Donald J; Chon, Ki H

    2006-02-01

    We have developed a method that can identify switching dynamics in time series, termed the improved annealed competition of experts (IACE) algorithm. In this paper, we extend the approach and use it for detection of linear and nonlinear interactions, by employing histograms showing the frequency of switching modes obtained from the IACE, then examining time-frequency spectra. This extended approach is termed Histogram of improved annealed competition of experts-time frequency (HIACE-TF). The hypothesis is that frequent switching dynamics in HIACE-TF results are due to interactions between different dynamic components. To validate this assertion, we used both simulation examples as well as application to renal blood flow data. We compared simulation results to a time-phase bispectrum (TPB) approach, which can also be used to detect time-varying quadratic phase coupling between various components. We found that the HIACE-TF approach is more accurate than the TPB in detecting interactions, and remains accurate for signal-to-noise ratios as low as 15 dB. With all 10 data sets, comprised of volumetric renal blood flow data, we also validated the feasibility of the HIACE-TF approach in detecting nonlinear interactions between the two mechanisms responsible for renal autoregulation. Further validation of the HIACE-TF approach was achieved by comparing it to a realistic mathematical model that has the capability to generate either the presence or the absence of nonlinear interactions between two renal autoregulatory mechanisms.

  11. Histological Image Feature Mining Reveals Emergent Diagnostic Properties for Renal Cancer

    PubMed Central

    Kothari, Sonal; Phan, John H.; Young, Andrew N.; Wang, May D.

    2016-01-01

    Computer-aided histological image classification systems are important for making objective and timely cancer diagnostic decisions. These systems use combinations of image features that quantify a variety of image properties. Because researchers tend to validate their diagnostic systems on specific cancer endpoints, it is difficult to predict which image features will perform well given a new cancer endpoint. In this paper, we define a comprehensive set of common image features (consisting of 12 distinct feature subsets) that quantify a variety of image properties. We use a data-mining approach to determine which feature subsets and image properties emerge as part of an “optimal” diagnostic model when applied to specific cancer endpoints. Our goal is to assess the performance of such comprehensive image feature sets for application to a wide variety of diagnostic problems. We perform this study on 12 endpoints including 6 renal tumor subtype endpoints and 6 renal cancer grade endpoints. Keywords-histology, image mining, computer-aided diagnosis PMID:28163980

  12. Segmentation of Individual Renal Cysts from MR Images in Patients with Autosomal Dominant Polycystic Kidney Disease

    PubMed Central

    Bae, Kyungsoo; Park, Bumwoo; Sun, Hongliang; Wang, Jinhong; Tao, Cheng; Chapman, Arlene B.; Torres, Vicente E.; Grantham, Jared J.; Mrug, Michal; Bennett, William M.; Flessner, Michael F.; Landsittel, Doug P.

    2013-01-01

    Summary Objective To evaluate the performance of a semi-automated method for the segmentation of individual renal cysts from magnetic resonance (MR) images in patients with autosomal dominant polycystic kidney disease (ADPKD). Design, setting, participants, & measurements This semi-automated method was based on a morphologic watershed technique with shape-detection level set for segmentation of renal cysts from MR images. T2-weighted MR image sets of 40 kidneys were selected from 20 patients with mild to moderate renal cyst burden (kidney volume < 1500 ml) in the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP). The performance of the semi-automated method was assessed in terms of two reference metrics in each kidney: the total number of cysts measured by manual counting and the total volume of cysts measured with a region-based thresholding method. The proposed and reference measurements were compared using intraclass correlation coefficient (ICC) and Bland-Altman analysis. Results Individual renal cysts were successfully segmented with the semi-automated method in all 20 cases. The total number of cysts in each kidney measured with the two methods correlated well (ICC, 0.99), with a very small relative bias (0.3% increase with the semi-automated method; limits of agreement, 15.2% reduction to 17.2% increase). The total volume of cysts measured using both methods also correlated well (ICC, 1.00), with a small relative bias of <10% (9.0% decrease in the semi-automated method; limits of agreement, 17.1% increase to 43.3% decrease). Conclusion This semi-automated method to segment individual renal cysts in ADPKD kidneys provides a quantitative indicator of severity in early and moderate stages of the disease. PMID:23520042

  13. Mid-Term Vascular Safety of Renal Denervation Assessed by Follow-up MR Imaging

    SciTech Connect

    Schmid, Axel Schmieder, Raphael; Lell, Michael; Janka, Rolf; Veelken, Roland; Schmieder, Roland E.; Uder, Michael; Ott, Christian

    2016-03-15

    Background/AimsRenal denervation (RDN) emerged as a treatment option for reducing blood pressure (BP) in patients with treatment-resistant hypertension (TRH). However, concerns have been raised regarding the incidence of late renal artery stenosis or thromboembolism after RDN. The goal of the current study was, therefore, to conduct a prospective clinical trial on the mid-term vascular integrity of the renal arteries and the perfusion of the renal parenchyma assessed by magnetic resonance imaging (MRI) in the follow-up after catheter-based RDN.MethodsIn our single-centre investigator initiated study, 51 patients with true TRH underwent catheter-based RDN using the Symplicity Flex{sup TM} catheter (Medtronic Inc., Palo Alto, CA). Follow-up MRI was performed at a median of 11 months (interquartile range 6–18 months) after RDN on a 1.5T MR unit. High-resolution MR angiography (MRA) and MRI results were compared to the baseline digital angiography of renal arteries obtained at time of RDN. In case of uncertainties (N = 2) catheter angiography was repeated.ResultsBoth office and 24-h ambulatory BP were significantly reduced 6 and 12 months after RDN. Renal function remained unchanged 6 and 12 months after RDN. In all patients, MRA excluded new or progression of pre-existing low grade renal artery stenosis as well as focal aneurysms at the sites of radiofrequency ablation. In none of the patients new segmental perfusion deficits in either kidney were detected on MRI.ConclusionsNo vascular or parenchymal complications after radiofrequency-based RDN were detected in 51 patients followed up by MRI.

  14. Enhanced dynamic range x-ray imaging.

    PubMed

    Haidekker, Mark A; Morrison, Logan Dain-Kelley; Sharma, Ajay; Burke, Emily

    2017-03-01

    X-ray images can suffer from excess contrast. Often, image exposure is chosen to visually optimize the region of interest, but at the expense of over- and underexposed regions elsewhere in the image. When image values are interpreted quantitatively as projected absorption, both over- and underexposure leads to the loss of quantitative information. We propose to combine multiple exposures into a composite that uses only pixels from those exposures in which they are neither under- nor overexposed. The composite image is created in analogy to visible-light high dynamic range photography. We present the mathematical framework for the recovery of absorbance from such composite images and demonstrate the method with biological and non-biological samples. We also show with an aluminum step-wedge that accurate recovery of step thickness from the absorbance values is possible, thereby highlighting the quantitative nature of the presented method. Due to the higher amount of detail encoded in an enhanced dynamic range x-ray image, we expect that the number of retaken images can be reduced, and patient exposure overall reduced. We also envision that the method can improve dual energy absorptiometry and even computed tomography by reducing the number of low-exposure ("photon-starved") projections.

  15. Nephron blood flow dynamics measured by laser speckle contrast imaging

    PubMed Central

    Holstein-Rathlou, Niels-Henrik; Sosnovtseva, Olga V.; Pavlov, Alexey N.; Cupples, William A.; Sorensen, Charlotte Mehlin

    2011-01-01

    Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular pressure and flow. Nephrons interact by exchanging electrical signals conducted electrotonically through cells of the vascular wall, leading to synchronization of the TGF-mediated oscillations. Experimental studies of these interactions have been limited to observations on two or at most three nephrons simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50–100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic techniques for extracting the desired data and for examining them for evidence of nephron synchronization. Synchronized TGF oscillations were detected in pairs or triplets of nephrons. The amplitude and the frequency of the oscillations changed with time, as did the patterns of synchronization. Synchronization may take place among nephrons not immediately adjacent on the surface of the kidney. PMID:21048025

  16. Nephron blood flow dynamics measured by laser speckle contrast imaging.

    PubMed

    Holstein-Rathlou, Niels-Henrik; Sosnovtseva, Olga V; Pavlov, Alexey N; Cupples, William A; Sorensen, Charlotte Mehlin; Marsh, Donald J

    2011-02-01

    Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular pressure and flow. Nephrons interact by exchanging electrical signals conducted electrotonically through cells of the vascular wall, leading to synchronization of the TGF-mediated oscillations. Experimental studies of these interactions have been limited to observations on two or at most three nephrons simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50-100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic techniques for extracting the desired data and for examining them for evidence of nephron synchronization. Synchronized TGF oscillations were detected in pairs or triplets of nephrons. The amplitude and the frequency of the oscillations changed with time, as did the patterns of synchronization. Synchronization may take place among nephrons not immediately adjacent on the surface of the kidney.

  17. NASA's Solar Dynamics Observatory Unveils New Images

    NASA Image and Video Library

    2010-04-20

    Philip H. Scherrer (left) principal investigator, Helioseismic and Magnetic Imager instrument, Stanford University in Palo Alto, speaks during a briefing to discuss recent images from NASA's Solar Dynamics Observatory, or SDO, while colleagues Tom Woods, principal investigator, Extreme Ultraviolet Variability Experiment instrument, Laboratory for Atmospheric and Space Physics, University of Colorado in Boulder and Madhulika Guhathakurta, SDO program scientist, NASA Headquarters (right) look on Wednesday, April 21, 2010, at the Newseum in Washington. Photo Credit: (NASA/Carla Cioffi)

  18. Tumour-related imaging parameters predicting the percentage of preserved normal renal parenchyma following nephron sparing surgery: a retrospective study.

    PubMed

    Aertsen, Michael; De Keyzer, Frederik; Van Poppel, Hendrik; Joniau, Steven; De Wever, Liesbeth; Lerut, Evelyne; Oyen, Raymond; Claus, Filip

    2013-01-01

    To examine pre-operative imaging parameters that predict the residual amount of healthy renal parenchyma after nephron sparing surgery (NSS) for renal tumours, as this can help stratify patients towards the optimal surgical choice. Ninety-eight patients with the diagnosis of a solitary unilateral renal tumour and with pre- and post-operative imaging were included in this retrospective study. Imaging, patient and surgical parameters were acquired and their correlation to the percentage decrease of healthy renal parenchyma following surgery was statistically examined to find the most significant predictor of nephron sparing. Loss of healthy renal parenchyma was highest in patients with renal sinus tumour involvement (P = 0.003) and anterior tumours (P = 0.006), but not significantly correlated with medial/lateral location (P = 0.940) or exophytic/endophytic tumour growth (P = 0.244). The correlation of tumour size with the percentage of parenchymal sparing did not quite reach statistical significance (P = 0.053), but involvement of the urinary collecting system (P = 0.008) was a very good predictor of complications. Loss of healthy renal parenchyma was higher in patients with high-grade surgical complications (P = 0.001). Several pre-operative parameters correlate to percentage nephron sparing after NSS. Anterior tumour location and renal sinus involvement proved to be the best predictors of loss of healthy renal parenchyma.

  19. Dynamic metamaterial aperture for microwave imaging

    SciTech Connect

    Sleasman, Timothy; Imani, Mohammadreza F.; Gollub, Jonah N.; Smith, David R.

    2015-11-16

    We present a dynamic metamaterial aperture for use in computational imaging schemes at microwave frequencies. The aperture consists of an array of complementary, resonant metamaterial elements patterned into the upper conductor of a microstrip line. Each metamaterial element contains two diodes connected to an external control circuit such that the resonance of the metamaterial element can be damped by application of a bias voltage. Through applying different voltages to the control circuit, select subsets of the elements can be switched on to create unique radiation patterns that illuminate the scene. Spatial information of an imaging domain can thus be encoded onto this set of radiation patterns, or measurements, which can be processed to reconstruct the targets in the scene using compressive sensing algorithms. We discuss the design and operation of a metamaterial imaging system and demonstrate reconstructed images with a 10:1 compression ratio. Dynamic metamaterial apertures can potentially be of benefit in microwave or millimeter wave systems such as those used in security screening and through-wall imaging. In addition, feature-specific or adaptive imaging can be facilitated through the use of the dynamic aperture.

  20. Live-Animal Imaging of Renal Function by Multiphoton Microscopy

    PubMed Central

    Dunn, Kenneth W.; Sutton, Timothy A.; Sandoval, Ruben M.

    2015-01-01

    Intravital microscopy, microscopy of living animals, is a powerful research technique that combines the resolution and sensitivity found in microscopic studies of cultured cells with the relevance and systemic influences of cells in the context of the intact animal. The power of intravital microscopy has recently been extended with the development of multiphoton fluorescence microscopy systems capable of collecting optical sections from deep within the kidney at subcellular resolution, supporting high-resolution characterizations of the structure and function of glomeruli, tubules, and vasculature in the living kidney. Fluorescent probes are administered to an anesthetized, surgically prepared animal, followed by image acquisition for up to 3 hr. Images are transferred via a high-speed network to specialized computer systems for digital image analysis. This general approach can be used with different combinations of fluorescent probes to evaluate processes such as glomerular permeability, proximal tubule endocytosis, microvascular flow, vascular permeability, mitochondrial function, and cellular apoptosis/necrosis. PMID:23042524

  1. Magnetic resonance imaging in the diagnosis and staging of renal and perirenal neoplasms.

    PubMed

    Hricak, H; Demas, B E; Williams, R D; McNamara, M T; Hedgcock, M W; Amparo, E G; Tanagho, E A

    1985-03-01

    Thirty-one adult patients underwent magnetic resonance (MR) imaging after CT scans had demonstrated findings consistent with renal cell carcinoma. MR images were interpreted prospectively and independently of the CT findings. Because the CT scanning was performed at multiple institutions by many examiners, this study was not a direct comparison of CT versus MR. The preoperative diagnoses and staging of the neoplasms, as judged by MR, were compared with those obtained at laparotomy (n = 28), autopsy (n = 1), or biopsy (n = 2). Correct preoperative diagnoses were rendered in 31 patients (100%) on the basis of MR findings. The anatomic staging of 27 renal cell carcinomas was correctly performed by MR in 26 patients (86%). When compared with results of previous studies of the value of CT in the diagnosis and staging of renal neoplasms, MR appears to have several advantages in determination of the origin of the mass; the evaluation of vascular patency; the detection of perihilar lymph node metastases; and the evaluation of direct tumor invasion of adjacent organs. MR is sensitive in determining the extent of tumor thrombus and in evaluating invasion of the inferior vena caval wall. MR should assume an important role in the diagnosis and staging of renal neoplasms.

  2. Penrose high-dynamic-range imaging

    NASA Astrophysics Data System (ADS)

    Li, Jia; Bai, Chenyan; Lin, Zhouchen; Yu, Jian

    2016-05-01

    High-dynamic-range (HDR) imaging is becoming increasingly popular and widespread. The most common multishot HDR approach, based on multiple low-dynamic-range images captured with different exposures, has difficulties in handling camera and object movements. The spatially varying exposures (SVE) technology provides a solution to overcome this limitation by obtaining multiple exposures of the scene in only one shot but suffers from a loss in spatial resolution of the captured image. While aperiodic assignment of exposures has been shown to be advantageous during reconstruction in alleviating resolution loss, almost all the existing imaging sensors use the square pixel layout, which is a periodic tiling of square pixels. We propose the Penrose pixel layout, using pixels in aperiodic rhombus Penrose tiling, for HDR imaging. With the SVE technology, Penrose pixel layout has both exposure and pixel aperiodicities. To investigate its performance, we have to reconstruct HDR images in square pixel layout from Penrose raw images with SVE. Since the two pixel layouts are different, the traditional HDR reconstruction methods are not applicable. We develop a reconstruction method for Penrose pixel layout using a Gaussian mixture model for regularization. Both quantitative and qualitative results show the superiority of Penrose pixel layout over square pixel layout.

  3. Renal radionuclide imaging, an evergreen forty years old.

    PubMed

    De Palma, D; Santos, A I

    2014-07-01

    Urinary tract congenital abnormalities (UCA) and febrile infections (UTI) are, respectively, 2 of the commonest congenital and acquired health problems in childhood. In both, radionuclide imaging still represent a cornerstone of diagnostic imaging, although the involved techniques are more or less the same from the early '80 s. During the last 2 decades, published papers focused on a deep revision about the optimal use and usefulness of such imaging tools in affected children, with the aim of reducing invasiveness, radiation burden and costs without losing efficacy. This approach leads to different results. In UCA, no consensus for a diagnostic algorithm was up to now reached, whilst, about febrile UTIs, guidelines were published in 2007 by the UK's National Institute for Clinical Excellence (NICE) and by the European Society of Paediatric Radiology (ESPR), in 2011 by the American Academy of Paediatrics (AAP), and in 2012 by the Italian Society of Paediatric Nephrology (SINP). Nevertheless, new data continuously arise and the scientific debate always revives. Every imaging tool now available has its own strengths and weaknesses, and so all published guidelines. All this body of knowledge must be critically analysed for obtaining a complete, up-to-date and flexible overview about these "always hot" topics.

  4. Bilateral urinothorax identified by technetium-99m DPTA renal imaging

    SciTech Connect

    Ralston, M.D.; Wilkinson, R.H. Jr.

    1986-01-01

    A case of unilateral urinary tract obstruction with extravasation resulting in bilateral pleural effusions is presented. The fluid within the pleural cavities was established to originate from the kidney using (/sup 99m/Tc)diethylenetriaminepentaacetic acid and scintillation camera imaging.

  5. NASA's Solar Dynamics Observatory Unveils New Images

    NASA Image and Video Library

    2010-04-20

    Tom Woods, (second from right), principal investigator, Extreme Ultraviolet Variability Experiment instrument, Laboratory for Atmospheric and Space Physics, University of Colorado in Boulder speaks during a briefing to discuss recent images from NASA's Solar Dynamics Observatory, or SDO, Wednesday, April 21, 2010, at the Newseum in Washington. Photo Credit: (NASA/Carla Cioffi)

  6. Unfused renal ectopia: a rare form of congenital renal anomaly.

    PubMed

    Nursal, Gül Nihal; Büyükdereli, Gülgün

    2005-09-01

    Unfused crossed renal ectopia observed 1 in 75,000 autopsies is a rare congenital anomaly. Typically one kidney is located in the proximity of the other kidney, and the ureter of the anatomically anomalous kidney crosses the midline to insert to the bladder in its normal anatomic position. Although renal function is usually not affected, the condition is generally accompanied by other congenital anomalies. In this case report, static and dynamic scintigraphic images of two patients with unfused crossed renal ectopia are presented. Besides properties of imaging modalities, clinical features are discussed in light of the available literature.

  7. Cardiovascular and pulmonary dynamics by quantitative imaging

    NASA Technical Reports Server (NTRS)

    Wood, E. H.

    1976-01-01

    The accuracy and range of studies on cardiovascular and pulmonary functions can be greatly facilitated if the motions of the underlying organ systems throughout individual cycles can be directly visualized and readily measured with minimum or preferably no effect on these motions. Achievement of this objective requires development of techniques for quantitative noninvasive or minimally invasive dynamic and stop-action imaging of the organ systems. A review of advances in dynamic quantitative imaging of moving organs reveals that the revolutionary value of cross-sectional and three-dimensional images produced by various types of radiant energy such as X-rays and gamma rays, positrons, electrons, protons, light, and ultrasound for clinical diagnostic and biomedical research applications is just beginning to be realized. The fabrication of a clinically useful cross-section reconstruction device with sensing capabilities for both anatomical structural composition and chemical composition may be possible and awaits future development.

  8. Multimodal Imaging of Dynamic Functional Connectivity

    PubMed Central

    Tagliazucchi, Enzo; Laufs, Helmut

    2015-01-01

    The study of large-scale functional interactions in the human brain with functional magnetic resonance imaging (fMRI) extends almost to the first applications of this technology. Due to historical reasons and preconceptions about the limitations of this brain imaging method, most studies have focused on assessing connectivity over extended periods of time. It is now clear that fMRI can resolve the temporal dynamics of functional connectivity, like other faster imaging techniques such as electroencephalography and magnetoencephalography (albeit on a different temporal scale). However, the indirect nature of fMRI measurements can hinder the interpretability of the results. After briefly summarizing recent advances in the field, we discuss how the simultaneous combination of fMRI with electrophysiological activity measurements can contribute to a better understanding of dynamic functional connectivity in humans both during rest and task, wakefulness, and other brain states. PMID:25762977

  9. Dynamic joint transform correlator of images

    NASA Astrophysics Data System (ADS)

    Angervaks, A. E.; Malyi, A. F.; Fedorov, I. U.; Shcheulin, A. S.

    2008-03-01

    In this article principles of operation of a coherent optical image correlator based on a well know optical joint transform correlator are examined. Theoretical predictions and experimental data for of the optical image correlator with a holographic filter recorded on a thin holographic photographic plates PFG - 01 are analyzed. Results of the operation of the dynamic joint transform correlator on the basis of cadmium fluoride crystal, CdF2, with bistable impurity centers are demonstrated. Calculated and experimental correlation peak intensity dependencies with the scale and angular mismatch between an observed and reference objects for static and dynamic joint transform correlators are compared. Tangram figures were used as a test images. In the paper all computations were performed by use of MATLAB 7.0.1 mathematical program.

  10. Overcoming Dynamic Disturbances in Imaging Systems

    NASA Technical Reports Server (NTRS)

    Young, Eric W.; Dente, Gregory C.; Lyon, Richard G.; Chesters, Dennis; Gong, Qian

    2000-01-01

    We develop and discuss a methodology with the potential to yield a significant reduction in complexity, cost, and risk of space-borne optical systems in the presence of dynamic disturbances. More robust systems almost certainly will be a result as well. Many future space-based and ground-based optical systems will employ optical control systems to enhance imaging performance. The goal of the optical control subsystem is to determine the wavefront aberrations and remove them. Ideally reducing an aberrated image of the object under investigation to a sufficiently clear (usually diffraction-limited) image. Control will likely be distributed over several elements. These elements may include telescope primary segments, telescope secondary, telescope tertiary, deformable mirror(s), fine steering mirror(s), etc. The last two elements, in particular, may have to provide dynamic control. These control subsystems may become elaborate indeed. But robust system performance will require evaluation of the image quality over a substantial range and in a dynamic environment. Candidate systems for improvement in the Earth Sciences Enterprise could include next generation Landsat systems or atmospheric sensors for dynamic imaging of individual, severe storms. The technology developed here could have a substantial impact on the development of new systems in the Space Science Enterprise; such as the Next Generation Space Telescope(NGST) and its follow-on the Next NGST. Large Interferometric Systems of non-zero field, such as Planet Finder and Submillimeter Probe of the Evolution of Cosmic Structure, could benefit. These systems most likely will contain large, flexible optormechanical structures subject to dynamic disturbance. Furthermore, large systems for high resolution imaging of planets or the sun from space may also benefit. Tactical and Strategic Defense systems will need to image very small targets as well and could benefit from the technology developed here. We discuss a novel

  11. Overcoming Dynamic Disturbances in Imaging Systems

    NASA Technical Reports Server (NTRS)

    Young, Eric W.; Dente, Gregory C.; Lyon, Richard G.; Chesters, Dennis; Gong, Qian

    2000-01-01

    We develop and discuss a methodology with the potential to yield a significant reduction in complexity, cost, and risk of space-borne optical systems in the presence of dynamic disturbances. More robust systems almost certainly will be a result as well. Many future space-based and ground-based optical systems will employ optical control systems to enhance imaging performance. The goal of the optical control subsystem is to determine the wavefront aberrations and remove them. Ideally reducing an aberrated image of the object under investigation to a sufficiently clear (usually diffraction-limited) image. Control will likely be distributed over several elements. These elements may include telescope primary segments, telescope secondary, telescope tertiary, deformable mirror(s), fine steering mirror(s), etc. The last two elements, in particular, may have to provide dynamic control. These control subsystems may become elaborate indeed. But robust system performance will require evaluation of the image quality over a substantial range and in a dynamic environment. Candidate systems for improvement in the Earth Sciences Enterprise could include next generation Landsat systems or atmospheric sensors for dynamic imaging of individual, severe storms. The technology developed here could have a substantial impact on the development of new systems in the Space Science Enterprise; such as the Next Generation Space Telescope(NGST) and its follow-on the Next NGST. Large Interferometric Systems of non-zero field, such as Planet Finder and Submillimeter Probe of the Evolution of Cosmic Structure, could benefit. These systems most likely will contain large, flexible optomechanical structures subject to dynamic disturbance. Furthermore, large systems for high resolution imaging of planets or the sun from space may also benefit. Tactical and Strategic Defense systems will need to image very small targets as well and could benefit from the technology developed here. We discuss a novel

  12. Spatiotemporal-atlas-based dynamic speech imaging

    NASA Astrophysics Data System (ADS)

    Fu, Maojing; Woo, Jonghye; Liang, Zhi-Pei; Sutton, Bradley P.

    2016-03-01

    Dynamic magnetic resonance imaging (DS-MRI) has been recognized as a promising method for visualizing articulatory motion of speech in scientific research and clinical applications. However, characterization of the gestural and acoustical properties of the vocal tract remains a challenging task for DS-MRI because it requires: 1) reconstructing high-quality spatiotemporal images by incorporating stronger prior knowledge; and 2) quantitatively interpreting the reconstructed images that contain great motion variability. This work presents a novel imaging method that simultaneously meets both requirements by integrating a spatiotemporal atlas into a Partial Separability (PS) model-based imaging framework. Through the use of an atlas-driven sparsity constraint, this method is capable of capturing high-quality articulatory dynamics at an imaging speed of 102 frames per second and a spatial resolution of 2.2 × 2.2 mm2. Moreover, the proposed method enables quantitative characterization of variability of speech motion, compared to the generic motion pattern across all subjects, through the spatial residual components.

  13. Role of tissue harmonic imaging in characterization of cystic renal lesions.

    PubMed

    Mohammed, Asmi; Sandhu, Manavjit S; Lal, Anupam; Sodhi, Kushaljit S; Sud, Kamal; Kohli, Harbir S

    2008-12-01

    To determine the utility of tissue harmonic imaging in evaluating cystic renal lesions and to compare these findings with conventional ultrasound guidance (USG) and CT. Thirty patients, detected with cystic renal lesions on routine USG (over a period of 18 months from July 2004 to December 2005 at the Postgraduate Institute of Medical Education and Research Chandigarh, Chandigarh, India) were included in this study. All patients underwent a conventional gray scale ultrasound study (GSI), followed by tissue harmonic imaging (THI) sonography on the same machine (advance technology limited high definition imaging 5000). Computed tomography of abdomen was carried out within one week of the ultrasound examinations. All images were evaluated for size, number, and location of lesions. The findings of THI sonography, conventional USG and CT of abdomen were recorded in their respective proformas. The images obtained by GSI, THI, and contrast enhanced CT were also evaluated for image quality, lesion conspicuity, and fluid-solid differentiation. Tissue harmonic imaging showed better image quality in 27 of 34 lesions, improvement in lesion conspicuity was found in 27 of 34 cystic lesions, and an improved solid-fluid differentiation in 30 of 34 lesions when compared to GSI. The THI provided additional information as compared to GSI in 8 patients. The grading of CT scan was significantly higher in overall image quality (p=0.007) and lesion conspicuity (p=0.004), but was non-significant for fluid-solid differentiation (p=0.23). Tissue harmonic imaging provides better image quality, lesion delineation, and superior characterization than conventional gray scale sonography.

  14. Quantitative planar imaging method for measurement of renal activity by using a conjugate-emission image and transmission data.

    PubMed

    Kojima, A; Ohyama, Y; Tomiguchi, S; Kira, M; Matsumoto, M; Takahashi, M; Motomura, N; Ichihara, T

    2000-03-01

    We are proposing a method to accurately measure renal activity in renography using Tc-99m labeled tracers. This method uses a conjugate-view image and transmission data for attenuation correction, the triple energy window (TEW) method for scatter correction, and background correction techniques that consider the source volume for accurate background activity correction. To examine this method in planar imaging, we performed two renal phantom studies with various uniform background activity concentrations. One study used two ideal box-shaped kidney phantoms with a thickness of 2 or 4 cm in a water tank and the other study employed two real kidney-shaped phantoms in a fillable abdominal cavity. For these studies the kidney phantom-to-background activity concentration ratio (S) was changed from 5 to infinity. The transmission data were obtained with an external Tc-99m line array source. The anterior- and posterior-view emission images were acquired with a dual-headed gamma camera simultaneously and the TEW method was used to correct scatter for the emission and transmission images. The results showed that this method with both the accurate background correction and scatter correction could give depth-independent count rates and could estimate the true count rate with errors of less than 5% for all S values. However, if either accurate background correction or scatter correction was performed alone, the absolute error increased to about 50% for the smaller S values. Our proposed method allows one to accurately and simply measure the renal radioactivity by planar imaging using the conjugate-emission image and transmission data.

  15. Generative technique for dynamic infrared image sequences

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Cao, Zhiguo; Zhang, Tianxu

    2001-09-01

    The generative technique of the dynamic infrared image was discussed in this paper. Because infrared sensor differs from CCD camera in imaging mechanism, it generates the infrared image by incepting the infrared radiation of scene (including target and background). The infrared imaging sensor is affected deeply by the atmospheric radiation, the environmental radiation and the attenuation of atmospheric radiation transfers. Therefore at first in this paper the imaging influence of all kinds of the radiations was analyzed and the calculation formula of radiation was provided, in addition, the passive scene and the active scene were analyzed separately. Then the methods of calculation in the passive scene were provided, and the functions of the scene model, the atmospheric transmission model and the material physical attribute databases were explained. Secondly based on the infrared imaging model, the design idea, the achievable way and the software frame for the simulation software of the infrared image sequence were introduced in SGI workstation. Under the guidance of the idea above, in the third segment of the paper an example of simulative infrared image sequences was presented, which used the sea and sky as background and used the warship as target and used the aircraft as eye point. At last the simulation synthetically was evaluated and the betterment scheme was presented.

  16. Ultrasonographic imaging for structural characterization of renal affections and diagnosis of associated chronic renal failure in 10 dogs.

    PubMed

    Kumar, Vijay; Kumar, Adarsh; Varshney, A C

    2011-01-01

    The present study comprises of 10 dogs of either sex with primary indication of azotaemia. All the dogs were subjected to detailed clinical, haematobiochemical, urinalysis, and microbiological examination along with radiographical and ultrasonographical examination. Based on the ultrasonographic structural abnormalities, the different renal affections associated with CRF in majority of dogs were diagnosed. The different affections included "end-stage" kidneys (n = 4), hydronephrosis (n = 1), renomegaly (n = 1), nephritis (n = 1), nephrolithiasis (n = 1), nephrocalcinosis (n = 1), and renal cyst (n = 1). The significant ultrasonographic features in these affections included small kidneys with loss of corticomedullary demarcation ("end-stage" kidneys); increased cortical echogenicity (nephritis); dilation of the renal pelvis, separation of the central renal sinus with anechoic space, atrophy of renal medulla, (hydronephrosis); enlarged kidneys with increased overall echogenicity of renal cortex (renomegaly and associated nephritis); hyperechoic-mineralized structure with shadowing (nephrolithiasis); diffuse, small, multiple hyperechoic structures in the renal parenchyma with distal acoustic shadowing (nephrocalcinosis); small spherical intercortical anechoic structures fluid (renal cysts). In the present study, ultrasound proved to be a quick, convenient, and sensitive modality in detecting alterations in renal size and parenchymal architecture. All the dogs so diagnosed with CRF were rendered conservative medical treatment to control clinical signs of uraemia; maintain adequate fluid, electrolyte, and acid/base balance; provide adequate nutrition; minimize progression of renal failure.

  17. Imaging extrasynaptic glutamate dynamics in the brain

    PubMed Central

    Sakamoto, Hirokazu; Iinuma, Sho; Yamasaki, Miwako; Watanabe, Masahiko; Hirose, Kenzo; Iino, Masamitsu

    2010-01-01

    Glutamate is the major neurotransmitter in the brain, mediating point-to-point transmission across the synaptic cleft in excitatory synapses. Using a glutamate imaging method with fluorescent indicators, we show that synaptic activity generates extrasynaptic glutamate dynamics in the vicinity of active synapses. These glutamate dynamics had magnitudes and durations sufficient to activate extrasynaptic glutamate receptors in brain slices. We also observed crosstalk between synapses—i.e., summation of glutamate released from neighboring synapses. Furthermore, we successfully observed that sensory input from the extremities induced extrasynaptic glutamate dynamics within the appropriate sensory area of the cerebral cortex in vivo. Thus, the present study clarifies the spatiotemporal features of extrasynaptic glutamate dynamics, and opens up an avenue to directly visualizing synaptic activity in live animals. PMID:20308566

  18. Polyglucose nanoparticles with renal elimination and macrophage avidity facilitate PET imaging in ischaemic heart disease

    PubMed Central

    Keliher, Edmund J.; Ye, Yu-Xiang; Wojtkiewicz, Gregory R.; Aguirre, Aaron D.; Tricot, Benoit; Senders, Max L.; Groenen, Hannah; Fay, Francois; Perez-Medina, Carlos; Calcagno, Claudia; Carlucci, Giuseppe; Reiner, Thomas; Sun, Yuan; Courties, Gabriel; Iwamoto, Yoshiko; Kim, Hye-Yeong; Wang, Cuihua; Chen, John W.; Swirski, Filip K.; Wey, Hsiao-Ying; Hooker, Jacob; Fayad, Zahi A.; Mulder, Willem J. M.; Weissleder, Ralph; Nahrendorf, Matthias

    2017-01-01

    Tissue macrophage numbers vary during health versus disease. Abundant inflammatory macrophages destruct tissues, leading to atherosclerosis, myocardial infarction and heart failure. Emerging therapeutic options create interest in monitoring macrophages in patients. Here we describe positron emission tomography (PET) imaging with 18F-Macroflor, a modified polyglucose nanoparticle with high avidity for macrophages. Due to its small size, Macroflor is excreted renally, a prerequisite for imaging with the isotope flourine-18. The particle's short blood half-life, measured in three species, including a primate, enables macrophage imaging in inflamed cardiovascular tissues. Macroflor enriches in cardiac and plaque macrophages, thereby increasing PET signal in murine infarcts and both mouse and rabbit atherosclerotic plaques. In PET/magnetic resonance imaging (MRI) experiments, Macroflor PET imaging detects changes in macrophage population size while molecular MRI reports on increasing or resolving inflammation. These data suggest that Macroflor PET/MRI could be a clinical tool to non-invasively monitor macrophage biology. PMID:28091604

  19. Pitfalls and Limitations of Radionuclide Renal Imaging in Pediatrics.

    PubMed

    Biassoni, Lorenzo

    2015-09-01

    The article presents common pitfalls encountered in pediatric radionuclide renography, illustrated with clinical cases. It is important to recognize normal variants. A good acquisition technique is essential. Correlation with other imaging techniques, with the clinical background and symptoms, is critical. A clear clinical question is essential: based on the question and knowing the strengths and weaknesses of each test, the test which can best answer the question can be selected. Awareness of the pitfalls of radionuclide renography helps avoid errors of interpretation and allows the selection of the most helpful test for clinical management.

  20. Global ENA Imaging of Earth's Dynamic Magnetosphere

    NASA Astrophysics Data System (ADS)

    Brandt, Pontus

    2015-04-01

    The interaction between singly charged ions of Earth's magnetosphere and its neutral exosphere and upper atmosphere gives rise to Energetic Neutral Atoms (ENAs). This has enabled several missions to remotely image the global injection dynamics of the ring current and plasma sheet, the outflow of ions from Earth's polar regions, and the location of the sub-solar magnetopause. In this presentation we review ENA observations by the Astrid, IMAGE, TWINS and IBEX missions. We focus on results from the IMAGE/HENA Camera including observations of proton and oxygen ion injections in to the ring current and their impact on the force-balance and ionospheric coupling in the inner magnetosphere. We report also on the status of inversion techniques for retrieving the ion spatial and pitch-angle distributions from ENA images. The presentation concludes with a discussion of future next steps in ENA instrumentation and analysis capabilities required to deliver the science as recommended by the Heliophysics Decadal Survey.

  1. Image fusion for dynamic contrast enhanced magnetic resonance imaging

    PubMed Central

    Twellmann, Thorsten; Saalbach, Axel; Gerstung, Olaf; Leach, Martin O; Nattkemper, Tim W

    2004-01-01

    Background Multivariate imaging techniques such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) have been shown to provide valuable information for medical diagnosis. Even though these techniques provide new information, integrating and evaluating the much wider range of information is a challenging task for the human observer. This task may be assisted with the use of image fusion algorithms. Methods In this paper, image fusion based on Kernel Principal Component Analysis (KPCA) is proposed for the first time. It is demonstrated that a priori knowledge about the data domain can be easily incorporated into the parametrisation of the KPCA, leading to task-oriented visualisations of the multivariate data. The results of the fusion process are compared with those of the well-known and established standard linear Principal Component Analysis (PCA) by means of temporal sequences of 3D MRI volumes from six patients who took part in a breast cancer screening study. Results The PCA and KPCA algorithms are able to integrate information from a sequence of MRI volumes into informative gray value or colour images. By incorporating a priori knowledge, the fusion process can be automated and optimised in order to visualise suspicious lesions with high contrast to normal tissue. Conclusion Our machine learning based image fusion approach maps the full signal space of a temporal DCE-MRI sequence to a single meaningful visualisation with good tissue/lesion contrast and thus supports the radiologist during manual image evaluation. PMID:15494072

  2. Intraoperative Computed Tomography Imaging for Navigated Laparoscopic Renal Surgery: First Clinical Experience.

    PubMed

    Simpfendörfer, Tobias; Gasch, Claudia; Hatiboglu, Gencay; Müller, Michael; Maier-Hein, Lena; Hohenfellner, Markus; Teber, Dogu

    2016-10-01

    Laparoscopic partial nephrectomy (LPN) remains challenging in endophytic and complex kidney tumors as the clear understanding of tumor location and spreading depends on a precise analysis of available imaging. The purpose of this study was to investigate navigated kidney surgery using intraoperative cone-beam computed tomography (CBCT) images in conjunction with a previously proposed method for augmented reality (AR) guidance for safe LPN. The concept proposed is based on using an intraoperative CBCT scan for (1) marker-based AR guidance for fast and reliable tumor access and (2) enhancement of real-time fluoroscopy images for accurate tumor resection. Workflow and accuracy of the system were assessed using a porcine kidney model. Ten patients with complex or endophytic tumor localization and R.E.N.A.L. Nephrometry Score of at least nine scheduled for LPN were included in this study. Patients received an intraoperative CBCT after marker placement. Defining the resection line was assisted by AR. In addition, fluoroscopy imaging for depth perception was used for assistance during dissection. Feasibility and performance were assessed by histopathological results, peri- and postoperative data. Surgery was performed successfully and negative margins were found in all cases. Segmental branches of the renal artery shifted as much as 10 mm in the vertical and 11 mm in the sagittal axis intraoperatively compared to preoperative imaging. Fluoroscopy to intraoperative computed tomography image fusion enabled enhanced depth perception during dissection in all cases. Radiation dose area product was 4.8 mGym(2). The application of the navigation system is feasible and allows for safe and direct access to complex or endophytic renal masses. Radiation limits the application to selected indications.

  3. Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

    SciTech Connect

    King, Deirdre M.; Fagan, Andrew J.; Moran, Carmel M.; Browne, Jacinta E.

    2011-02-15

    Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease. Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR relaxometry (T{sub 1},T{sub 2}) properties, and Hounsfield number/x-ray attenuation coefficient, with a design capable of tolerating high-pressure pulsatile flow. Fiducial targets, incorporated into the phantoms to allow for registration of images among modalities, were chosen to minimize geometric distortions. Results: High quality distortion-free images of the phantoms with good contrast between vessel lumen, fiducial markers, and background tissue to visualize all stenoses were obtained with each modality. Quantitative assessments of the grade of stenosis revealed significant discrepancies between modalities, with each underestimating the stenosis severity for the higher-stenosed phantoms (70% and 85%) by up to 14%, with the greatest discrepancy attributable to DSA. Conclusions: The design and construction of a range of anatomically realistic renal artery phantoms containing varying degrees of stenosis is described. Images obtained using the main four diagnostic techniques used to detect RAS were free from artifacts and exhibited adequate contrast

  4. Bayesian blind separation and deconvolution of dynamic image sequences using sparsity priors.

    PubMed

    Tichy, Ondrej; Smidl, Vaclav

    2015-01-01

    A common problem of imaging 3-D objects into image plane is superposition of the projected structures. In dynamic imaging, projection overlaps of organs and tissues complicate extraction of signals specific to individual structures with different dynamics. The problem manifests itself also in dynamic tomography as tissue mixtures are present in voxels. Separation of signals specific to dynamic structures belongs to the category of blind source separation. It is an underdetermined problem with many possible solutions. Existing separation methods select the solution that best matches their additional assumptions on the source model. We propose a novel blind source separation method based on probabilistic model of dynamic image sequences assuming each source dynamics as convolution of an input function and a source specific kernel (modeling organ impulse response or retention function). These assumptions are formalized as a Bayesian model with hierarchical prior and solved by the Variational Bayes method. The proposed prior distribution assigns higher probability to sparse source images and sparse convolution kernels. We show that the results of separation are relevant to selected tasks of dynamic renal scintigraphy. Accuracy of tissue separation with simulated and clinical data provided by the proposed method outperformed accuracy of previously developed methods measured by the mean square and mean absolute errors of estimation of simulated sources and the sources separated by an expert physician. MATLAB implementation of the algorithm is available for download.

  5. Enhanced resolution of interstitial fibrosis in pediatric renal allograft biopsies using image analysis of trichrome stain.

    PubMed

    Birk, Patricia E; Gill, John S; Blydt-Hansen, Tom D; Gibson, Ian W

    2010-11-01

    The Banff classification is ill suited to detect subtle histologic progression in renal allografts. We present image analysis methodology to precisely quantify IF in pediatric renal allograft biopsies routinely stained with MT. The mean area %IF was determined in 105 pediatric renal allograft biopsies. Associations between %IF or Banff ci scores and estimated GFR were determined using GEE modeling. Logistic regression was used to estimate IF progression. Percent IF (mean ± s.d.) was 6.83% ± 3.94, 10.39 ± 5.23%, and 20.53 ± 8.74 in patients with ci0, ci1, and ci2, respectively. The difference in %IF between biopsies with ci0, ci1, and ci2 was not proportionately incremental: compared to ci2, ci0 had 67% less IF (p < 0.0001), while ci1 had 48% less IF (p < 0.0001). AR had no impact on the precision of %IF measurements. Each 0.5% decrement in %IF was associated with a 1 mL/min per 1.73 m² increase in GFR (p < 0.004). Histologic progression was demonstrated by increasing %IF values (p < 0.0001) and could be estimated by IF = 2.61 × (months) + 6.43. This readily adaptable methodology may be used for the longitudinal assessment of IF in pediatric protocol renal allograft biopsies. © 2010 John Wiley & Sons A/S.

  6. Automated 3D renal segmentation based on image partitioning

    NASA Astrophysics Data System (ADS)

    Yeghiazaryan, Varduhi; Voiculescu, Irina D.

    2016-03-01

    Despite several decades of research into segmentation techniques, automated medical image segmentation is barely usable in a clinical context, and still at vast user time expense. This paper illustrates unsupervised organ segmentation through the use of a novel automated labelling approximation algorithm followed by a hypersurface front propagation method. The approximation stage relies on a pre-computed image partition forest obtained directly from CT scan data. We have implemented all procedures to operate directly on 3D volumes, rather than slice-by-slice, because our algorithms are dimensionality-independent. The results picture segmentations which identify kidneys, but can easily be extrapolated to other body parts. Quantitative analysis of our automated segmentation compared against hand-segmented gold standards indicates an average Dice similarity coefficient of 90%. Results were obtained over volumes of CT data with 9 kidneys, computing both volume-based similarity measures (such as the Dice and Jaccard coefficients, true positive volume fraction) and size-based measures (such as the relative volume difference). The analysis considered both healthy and diseased kidneys, although extreme pathological cases were excluded from the overall count. Such cases are difficult to segment both manually and automatically due to the large amplitude of Hounsfield unit distribution in the scan, and the wide spread of the tumorous tissue inside the abdomen. In the case of kidneys that have maintained their shape, the similarity range lies around the values obtained for inter-operator variability. Whilst the procedure is fully automated, our tools also provide a light level of manual editing.

  7. Tip Cells Act as Dynamic Cellular Anchors in the Morphogenesis of Looped Renal Tubules in Drosophila

    PubMed Central

    Weavers, Helen; Skaer, Helen

    2013-01-01

    Summary Tissue morphogenesis involves both the sculpting of tissue shape and the positioning of tissues relative to one another in the body. Using the renal tubules of Drosophila, we show that a specific distal tubule cell regulates both tissue architecture and position in the body cavity. Focusing on the anterior tubules, we demonstrate that tip cells make transient contacts with alary muscles at abdominal segment boundaries, moving progressively forward as convergent extension movements lengthen the tubule. Tip cell anchorage antagonizes forward-directed, TGF-β-guided tubule elongation, thereby ensuring the looped morphology characteristic of renal tubules from worms to humans. Distinctive tip cell exploratory behavior, adhesion, and basement membrane clearing underlie target recognition and dynamic interactions. Defects in these features obliterate tip cell anchorage, producing misshapen and misplaced tubules with impaired physiological function. PMID:24229645

  8. Dynamic 99mTc-MAG3 renography: images for quality control obtained by combining pharmacokinetic modelling, an anthropomorphic computer phantom and Monte Carlo simulated scintillation camera imaging

    NASA Astrophysics Data System (ADS)

    Brolin, Gustav; Sjögreen Gleisner, Katarina; Ljungberg, Michael

    2013-05-01

    In dynamic renal scintigraphy, the main interest is the radiopharmaceutical redistribution as a function of time. Quality control (QC) of renal procedures often relies on phantom experiments to compare image-based results with the measurement setup. A phantom with a realistic anatomy and time-varying activity distribution is therefore desirable. This work describes a pharmacokinetic (PK) compartment model for 99mTc-MAG3, used for defining a dynamic whole-body activity distribution within a digital phantom (XCAT) for accurate Monte Carlo (MC)-based images for QC. Each phantom structure is assigned a time-activity curve provided by the PK model, employing parameter values consistent with MAG3 pharmacokinetics. This approach ensures that the total amount of tracer in the phantom is preserved between time points, and it allows for modifications of the pharmacokinetics in a controlled fashion. By adjusting parameter values in the PK model, different clinically realistic scenarios can be mimicked, regarding, e.g., the relative renal uptake and renal transit time. Using the MC code SIMIND, a complete set of renography images including effects of photon attenuation, scattering, limited spatial resolution and noise, are simulated. The obtained image data can be used to evaluate quantitative techniques and computer software in clinical renography.

  9. Dynamic (99m)Tc-MAG3 renography: images for quality control obtained by combining pharmacokinetic modelling, an anthropomorphic computer phantom and Monte Carlo simulated scintillation camera imaging.

    PubMed

    Brolin, Gustav; Gleisner, Katarina Sjögreen; Ljungberg, Michael

    2013-05-21

    In dynamic renal scintigraphy, the main interest is the radiopharmaceutical redistribution as a function of time. Quality control (QC) of renal procedures often relies on phantom experiments to compare image-based results with the measurement setup. A phantom with a realistic anatomy and time-varying activity distribution is therefore desirable. This work describes a pharmacokinetic (PK) compartment model for (99m)Tc-MAG3, used for defining a dynamic whole-body activity distribution within a digital phantom (XCAT) for accurate Monte Carlo (MC)-based images for QC. Each phantom structure is assigned a time-activity curve provided by the PK model, employing parameter values consistent with MAG3 pharmacokinetics. This approach ensures that the total amount of tracer in the phantom is preserved between time points, and it allows for modifications of the pharmacokinetics in a controlled fashion. By adjusting parameter values in the PK model, different clinically realistic scenarios can be mimicked, regarding, e.g., the relative renal uptake and renal transit time. Using the MC code SIMIND, a complete set of renography images including effects of photon attenuation, scattering, limited spatial resolution and noise, are simulated. The obtained image data can be used to evaluate quantitative techniques and computer software in clinical renography.

  10. Registration of renal SPECT and 2.5D US images.

    PubMed

    Galdames, Francisco J; Perez, Claudio A; Estévez, Pablo A; Held, Claudio M; Jaillet, Fabrice; Lobo, Gabriel; Donoso, Gilda; Coll, Claudia

    2011-06-01

    Image registration is the process of transforming different image data sets of an object into the same coordinate system. This is a relevant task in the field of medical imaging; one of its objectives is to combine information from different imaging modalities. The main goal of this study is the registration of renal SPECT (Single Photon Emission Computerized Tomography) images and a sparse set of ultrasound slices (2.5D US), combining functional and anatomical information. Registration is performed after kidney segmentation in both image types. The SPECT segmentation is achieved using a deformable model based on a simplex mesh. The 2.5D US image segmentation is carried out in each of the 2D slices employing a deformable contour and Gabor filters to capture multi-scale image features. Moreover, a renal medulla detection method was developed to improve the US segmentation. A nonlinear optimization algorithm is used for the registration. In this process, movements caused by patient breathing during US image acquisition are also corrected. Only a few reports describe registration between SPECT images and a sparse set of US slices of the kidney, and they usually employ an optical localizer, unlike our method, that performs movement correction using information only from the SPECT and US images. Moreover, it does not require simultaneous acquisition of both image types. The registration method and both segmentations were evaluated separately. The SPECT segmentation was evaluated qualitatively by medical experts, obtaining a score of 5 over a scale from 1 to 5, where 5 represents a perfect segmentation. The 2.5D US segmentation was evaluated quantitatively, by comparing our method with an expert manual segmentation, and obtaining an average error of 3.3mm. The registration was evaluated quantitatively and qualitatively. Quantitatively the distance between the manual segmentation of the US images and the model extracted from the SPECT image was measured, obtaining an

  11. Virtual center for renal support: technological approach to patient physiological image.

    PubMed

    Prado, Manuel; Roa, Laura; Reina-Tosina, Javier; Palma, Alfonso; Milán, José Antonio

    2002-12-01

    The patient physiological image (PPI) is a novel concept which manages the knowledge of the virtual center for renal support (VCRS), currently being developed by the Biomedical Engineering Group of the University of Seville. PPI is a virtual "replica" of the patient, built by means of a mathematical model, which represents several physiological subsystems of a renal patient. From a technical point of view, PPI is a component-oriented software module based on cutting-edge modeling and simulation technology. This paper provides a methodological and technological approach to the PPI. Computational architecture of PPI-based VCRS is also described. This is a multi-tier and multi-protocol system. Data are managed by several ORDBMS instances. Communications design is based on the virtual private network (VPN) concept. Renal patients have a minimum reliable access to the VCRS through a public switch telephone network--X.25 gateway. Design complies with the universal access requirement, allowing an efficient and inexpensive connection even in rural environments and reducing computational requirements in the patient's remote access unit. VCRS provides support for renal patients' healthcare, increasing the quality and quantity of monitored biomedical signals, predicting events as hypotension or low dialysis dose, assisting further to avoid them by an online therapy modification and easing diagnostic tasks. An online therapy adjustment experiment simulation is presented. Finally, the presented system serves as a computational aid for research in renal physiology. This is achieved by an open and reusable modeling and simulation architecture which allows the interaction among models and data from different scales and computer platforms, and a faster transference of investigation models toward clinical applications.

  12. Detection and Evaluation of Renal Injury in Burst Wave Lithotripsy Using Ultrasound and Magnetic Resonance Imaging.

    PubMed

    May, Philip C; Kreider, Wayne; Maxwell, Adam D; Wang, Yak-Nam; Cunitz, Bryan W; Blomgren, Philip M; Johnson, Cynthia D; Park, Joshua S H; Bailey, Michael R; Lee, Donghoon; Harper, Jonathan D; Sorensen, Mathew D

    2017-08-01

    Burst wave lithotripsy (BWL) is a transcutaneous technique with potential to safely and effectively fragment renal stones. Preclinical investigations of BWL require the assessment of potential renal injury. This study evaluates the capabilities of real-time ultrasound and MRI to detect and evaluate BWL injury that was induced in porcine kidneys. Ten kidneys from five female farm pigs were treated with either a 170 or 335 kHz BWL transducer using variable treatment parameters and monitored in real-time with ultrasound. Eight kidneys were perfusion fixed and scanned with a 3-Tesla MRI scanner (T1-weighted, T2-weighted, and susceptibility-weighted imaging), followed by processing via an established histomorphometric technique for injury quantification. In addition, two kidneys were separately evaluated for histologic characterization of injury quality. Observed B-mode hyperechoes on ultrasound consistent with cavitation predicted the presence of BWL-induced renal injury with a sensitivity and specificity of 100% in comparison to the histomorphometric technique. Similarly, MRI detected renal injury with a sensitivity of 90% and specificity of 100% and was able to identify the scale of lesion volumes. The injuries purposefully generated with BWL were histologically similar to those formed by shock wave lithotripsy. BWL-induced renal injury can be detected with a high degree of sensitivity and specificity by real-time ultrasound and post-treatment ex vivo MRI. No injury occurred in this study without cavitation detected on ultrasound. Such capabilities for injury detection and lesion volume quantification on MRI can be used for preclinical testing of BWL.

  13. In vivo imaging of cellular proliferation in renal cell carcinoma using 18F-fluorothymidine PET

    PubMed Central

    Wong, Peter K.; Lee, Sze Ting; Murone, Carmel; Eng, John; Lawrentschuk, Nathan; Berlangieri, Salvatore U.; Pathmaraj, Kunthi; O’Keefe, Graeme J.; Sachinidis, John; Byrne, Amanda J.; Bolton, Damien M.; Davis, Ian D.; Scott, Andrew M.

    2014-01-01

    Objective(s): The ability to measure cellular proliferation non-invasively in renal cell carcinoma may allow prediction of tumour aggressiveness and response to therapy. The aim of this study was to evaluate the uptake of 18F-fluorothymidine (FLT) PET in renal cell carcinoma (RCC), and to compare this to 18F-fluorodeoxyglucose (FDG), and to an immunohistochemical measure of cellular proliferation (Ki-67). Methods: Twenty seven patients (16 male, 11 females; age 42-77) with newly diagnosed renal cell carcinoma suitable for resection were prospectively enrolled. All patients had preoperative FLT and FDG PET scans. Visual identification of tumour using FLT PET compared to normal kidney was facilitated by the use of a pre-operative contrast enhanced CT scan. After surgery tumour was taken for histologic analysis and immunohistochemical staining by Ki-67. Results: The SUVmax (maximum standardized uptake value) mean±SD for FLT in tumour was 2.59±1.27, compared to normal kidney (2.47±0.34). The mean SUVmax for FDG in tumour was similar to FLT (2.60±1.08). There was a significant correlation between FLT uptake and the immunohistochemical marker Ki-67 (r=0.72, P<0.0001) in RCC. Ki-67 proliferative index was mean ± SD of 13.3%±9.2 (range 2.2% - 36.3%). Conclusion: There is detectable uptake of FLT in primary renal cell carcinoma, which correlates with cellular proliferation as assessed by Ki-67 labelling index. This finding has relevance to the use of FLT PET in molecular imaging studies of renal cell carcinoma biology. PMID:27408853

  14. Digital Image Correlation with Dynamic Subset Selection

    NASA Astrophysics Data System (ADS)

    Hassan, Ghulam Mubashar; MacNish, Cara; Dyskin, Arcady; Shufrin, Igor

    2016-09-01

    The quality of the surface pattern and selection of subset size play a critical role in achieving high accuracy in Digital Image Correlation (DIC). The subset size in DIC is normally selected by testing different subset sizes across the entire image, which is a laborious procedure. This also leads to the problem that the worst region of the surface pattern influences the performance of DIC across the entire image. In order to avoid these limitations, a Dynamic Subset Selection (DSS) algorithm is proposed in this paper to optimize the subset size for each point in an image before optimizing the correlation parameters. The proposed DSS algorithm uses the local pattern around the point of interest to calculate a parameter called the Intensity Variation Ratio (Λ), which is used to optimize the subset size. The performance of the DSS algorithm is analyzed using numerically generated images and is compared with the results of traditional DIC. Images obtained from laboratory experiments are also used to demonstrate the utility of the DSS algorithm. Results illustrate that the DSS algorithm provides a better alternative to subset size "guessing" and finds an appropriate subset size for each point of interest according to the local pattern.

  15. Dynamic targeting image-guided radiotherapy

    SciTech Connect

    Huntzinger, Calvin; Munro, Peter; Johnson, Scott; Miettinen, Mika; Zankowski, Corey; Ahlstrom, Greg; Glettig, Reto; Filliberti, Reto; Kaissl, Wolfgang; Kamber, Martin; Amstutz, Martin; Bouchet, Lionel; Klebanov, Dan; Mostafavi, Hassan; Stark, Richard

    2006-07-01

    Volumetric imaging and planning for 3-dimensional (3D) conformal radiotherapy and intensity-modulated radiotherapy (IMRT) have highlighted the need to the oncology community to better understand the geometric uncertainties inherent in the radiotherapy delivery process, including setup error (interfraction) as well as organ motion during treatment (intrafraction). This has ushered in the development of emerging technologies and clinical processes, collectively referred to as image-guided radiotherapy (IGRT). The goal of IGRT is to provide the tools needed to manage both inter- and intrafraction motion to improve the accuracy of treatment delivery. Like IMRT, IGRT is a process involving all steps in the radiotherapy treatment process, including patient immobilization, computed tomogaphy (CT) simulation, treatment planning, plan verification, patient setup verification and correction, delivery, and quality assurance. The technology and capability of the Dynamic Targeting{sup TM} IGRT system developed by Varian Medical Systems is presented. The core of this system is a Clinac (registered) or Trilogy{sup TM} accelerator equipped with a gantry-mounted imaging system known as the On-Board Imager{sup TM} (OBI). This includes a kilovoltage (kV) x-ray source, an amorphous silicon kV digital image detector, and 2 robotic arms that independently position the kV source and imager orthogonal to the treatment beam. A similar robotic arm positions the PortalVision{sup TM} megavoltage (MV) portal digital image detector, allowing both to be used in concert. The system is designed to support a variety of imaging modalities. The following applications and how they fit in the overall clinical process are described: kV and MV planar radiographic imaging for patient repositioning, kV volumetric cone beam CT imaging for patient repositioning, and kV planar fluoroscopic imaging for gating verification. Achieving image-guided motion management throughout the radiation oncology process

  16. Motility Contrast Imaging and Tissue Dynamics Spectroscopy

    NASA Astrophysics Data System (ADS)

    Nolte, David D.; An, Ran; Turek, John

    Motion is the defining physiological characteristic of living matter. If we are interested in how things function, then the way they move is most informative. Motion provides an endogenous and functional suite of biomarkers that are sensitive to subtle changes that occur under applied pharmacological doses or cellular stresses. This chapter reviews the application of biodynamic imaging to measure cellular dynamics in three-dimensional tissue culture for drug screening applications. Nanoscale and microscale motions are detected through statistical fluctuations in dynamic speckle across an ensemble of cells within each resolution voxel. Tissue dynamics spectroscopy generates drug-response spectrograms that serve as phenotypic fingerprints of drug action and can differentiate responses from heterogeneous regions of tumor tissue.

  17. Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

    PubMed Central

    Borelli, Flavio Antonio de Oliveira; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R.

    2013-01-01

    Background Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. Objective To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. Methods In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). Results The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m2. Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Conclusion Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction. PMID:24061685

  18. NASA's Solar Dynamics Observatory Unveils New Images

    NASA Image and Video Library

    2010-04-20

    Alan Title, second from left, principal investigator, Atmospheric Imaging Assembly instrument, Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto, speaks during a briefing to discuss recent images from NASA's Solar Dynamics Observatory, or SDO, Wednesday, April 21, 2010, at the Newseum in Washington. Launched on Feb. 11, 2010, SDO is the most advanced spacecraft ever designed to study the sun. During its five-year mission, it will examine the sun's magnetic field and also provide a better understanding of the role the sun plays in Earth's atmospheric chemistry and climate. Pictured from left to right: Dean Pesnell, SDO project scientist, Goddard Space Flight Center in Greenbelt, Md., Alan Title, Philip H. Scherrer, principal investigator, Helioseismic and Magnetic Imager instrument, Stanford University in Palo Alto, Tom Woods, principal investigator, Extreme Ultraviolet Variability Experiment instrument, Laboratory for Atmospheric and Space Physics, University of Colorado in Boulder and Madhulika Guhathakurta, SDO program scientist, NASA Headquarters in Washington. Photo Credit: (NASA/Carla Cioffi)

  19. Neutron Imaging Reveals Internal Plant Hydraulic Dynamics

    SciTech Connect

    Warren, Jeffrey; Bilheux, Hassina Z; Kang, Misun; Voisin, Sophie; Cheng, Chu-Lin; Horita, Jusuke; Perfect, Edmund

    2013-01-01

    Many terrestrial ecosystem processes are constrained by water availability and transport within the soil. Knowledge of plant water fluxes is thus critical for assessing mechanistic processes linked to biogeochemical cycles, yet resolution of root structure and xylem water transport dynamics has been a particularly daunting task for the ecologist. Through neutron imaging, we demonstrate the ability to non-invasively monitor individual root functionality and water fluxes within Zea mays L. (maize) and Panicum virgatum L. (switchgrass) seedlings growing in a sandy medium. Root structure and growth were readily imaged by neutron radiography and neutron computed tomography. Seedlings were irrigated with water or deuterium oxide and imaged through time as a growth lamp was cycled on to alter leaf demand for water. Sub-millimeter scale resolution reveals timing and magnitudes of root water uptake, redistribution within the roots, and root-shoot hydraulic linkages, relationships not well characterized by other techniques.

  20. Obstacle penetrating dynamic radar imaging system

    DOEpatents

    Romero, Carlos E.; Zumstein, James E.; Chang, John T.; Leach, Jr.. Richard R.

    2006-12-12

    An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.

  1. NASA's Solar Dynamics Observatory Unveils New Images

    NASA Image and Video Library

    2010-04-20

    Scientists involved in NASA's Solar Dynamics Observatory (SDO) mission attend a press conference to discuss recent images captured by the SDO spacecraft Wednesday, April 21, 2010, at the Newseum in Washington. On Feb. 11, 2010, NASA launched the SDO spacecraft, which is the most advanced spacecraft ever designed to study the sun. Seated left to right are: Dean Pesnell, SDO project scientist, Goddard Space Flight Center in Greenbelt, Md.; Alan Title, principal investigator, Atmospheric Imaging Assembly instrument, Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto; Philip H. Scherrer, principal investigator, Helioseismic and Magnetic Imager instrument, Stanford University in Palo Alto; Tom Woods, principal investigator, Extreme Ultraviolet Variability Experiment Instrument, Laboratory for Atmospheric and Space Physics, University of Colorado in Boulder and Madhulika Guhathakurta, SDO program scientist, NASA Headquarters in Washington. Photo Credit: (NASA/Carla Cioffi)

  2. NASA's Solar Dynamics Observatory Unveils New Images

    NASA Image and Video Library

    2010-04-20

    Scientists involved in NASA's Solar Dynamics Observatory (SDO) mission attend a press conference to discuss recent images captured by the SDO spacecraft Wednesday, April 21, 2010, at the Newseum in Washington. Pictured right to left are: Madhulika Guhathakurta, SDO program scientist, NASA Headquarters in Washington; Tom Woods, principal investigator, Extreme Ultraviolet Variability Experiment instrument, Laboratory for Atmospheric and Space Physics, University of Colorado in Boulder; Philip H. Scherrer, principal investigator, Helioseismic and Magnetic Imager instrument, Stanford University in Palo Alto; Alan Title, principal investigator, Atmospheric Imaging Assembly instrument, Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto and Dean Pesnell, SDO project scientist, Goddard Space Flight Center in Greenbelt, Md. Photo Credit: (NASA/Carla Cioffi)

  3. NASA's Solar Dynamics Observatory Unveils New Images

    NASA Image and Video Library

    2010-04-20

    Madhulika Guhathakurta, far right, SDO Program Scientist at NASA Headquarters in Washington, speaks during a briefing to discuss recent images from NASA's Solar Dynamics Observatory, or SDO, Wednesday, April 21, 2010, at the Newseum in Washington. Pictured from left of Dr. Guhathakurta's are: Tom Woods, principal investigator, Extreme Ultraviolet Variability Experiment instrument, Laboratory for Atmospheric and Space Physics, University of Colorado in Boulder; Philip H. Scherrer, principal investigator, Helioseismic and Magnetic Imager instrument, Stanford University in Palo Alto; Alan Title, principal investigator, Atmospheric Imaging Assembly instrument, Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto and Dean Pesnell, SDO project scientist, Goddard Space Flight Center in Greenbelt, Md. Photo Credit: (NASA/Carla Cioffi)

  4. Utility of post-urinary tract infection imaging in patients with normal prenatal renal ultrasound.

    PubMed

    Sasaki, Jun; Parajuli, Nirmala; Sharma, Preeti; Nanda, Maya; Shah, Rina; Gershel, Jeffrey; Rauch, Daniel A

    2012-03-01

    The American Academy of Pediatrics recommends renal ultrasound (RUS) and voiding cystourethrography (VCUG) for all infants after a first urinary tract infection (UTI). However, many congenital renal anomalies are identified by a prenatal US. At the present time, there are no data regarding the yield of post-UTI imaging among infants who have a documented normal prenatal US. We retrospectively reviewed the charts of all patients <1 year of age with a first UTI who had normal kidneys noted on prenatal US to determine the frequency of abnormal findings. Abnormal RUS and VCUG results were noted in 5.1% (24 of 471) and 20.4% (75 of 368) of infants, respectively. While the abnormal US rate is significantly less than what has been previously reported, the frequency of abnormal VCUGs is similar. These results suggest that a post-UTI RUS may not be needed if the prenatal US was normal. However, a VCUG continues to be indicated.

  5. Imaging of hemorrhagic fever with renal syndrome: a potential bioterrorism agent of military significance.

    PubMed

    Bui-Mansfield, Liem T; Cressler, Dana K

    2011-11-01

    Hemorrhagic fever with renal syndrome (HFRS) is a potentially fatal infectious disease with worldwide distribution. Its etiologic agents are viruses of the genus Hantavirus of the virus family Bunyaviridae. Hypothetical ease of production and distribution of these agents, with their propensity to incapacitate victims and overwhelm health care resources, lend themselves as significant potential biological agents of terrorism. HFRS has protean clinical manifestations, which may mimic upper respiratory tract infection, nephrolithiasis, and Hantavirus pulmonary syndrome and may delay proper treatment. Sequelae of HFRS, such as hemorrhage, acute renal failure, retroperitoneal edema, pancreatitis, pulmonary edema, and neurologic symptoms, can be detected by different imaging modalities. Medical providers caring for HFRS patients must be aware of its radiologic features, which may help to confirm its clinical diagnosis. In this article, the authors review the epidemiology, pathophysiology, clinical presentation, diagnosis, treatment, and complications of HFRS.

  6. Acoustic radiation force impulse imaging for evaluation of renal parenchyma elasticity in diabetic nephropathy.

    PubMed

    Goya, Cemil; Kilinc, Faruk; Hamidi, Cihad; Yavuz, Alpaslan; Yildirim, Yasar; Cetincakmak, Mehmet Guli; Hattapoglu, Salih

    2015-02-01

    OBJECTIVE. The goal of this study is to evaluate the changes in the elasticity of the renal parenchyma in diabetic nephropathy using acoustic radiation force impulse imaging. SUBJECTS AND METHODS. The study included 281 healthy volunteers and 114 patients with diabetic nephropathy. In healthy volunteers, the kidney elasticity was assessed quantitatively by measuring the shear-wave velocity using acoustic radiation force impulse imaging based on age, body mass index, and sex. The changes in the renal elasticity were compared between the different stages of diabetic nephropathy and the healthy control group. RESULTS. In healthy volunteers, there was a statistically significant correlation between the shear-wave velocity values and age and sex. The shear-wave velocity values for the kidneys were 2.87, 3.14, 2.95, 2.68, and 2.55 m/s in patients with stage 1, 2, 3, 4, and 5 diabetic nephropathy, respectively, compared with 2.35 m/s for healthy control subjects. Acoustic radiation force impulse imaging was able to distinguish between the different diabetic nephropathy stages (except for stage 5) in the kidneys. The threshold value for predicting diabetic nephropathy was 2.43 m/s (sensitivity, 84.1%; specificity, 67.3%; positive predictive value, 93.1%; negative predictive value 50.8%; accuracy, 72.1%; positive likelihood ratio, 2.5; and negative likelihood ratio, 0.23). CONCLUSION. Acoustic radiation force impulse imaging could be used for the evaluation of the renal elasticity changes that are due to secondary structural and functional changes in diabetic nephropathy.

  7. Dynamic gadolinium-enhanced magnetic resonance urography for assessing drainage in dilated pelvicalyceal systems with moderate renal function: preliminary results and comparison with diuresis renography.

    PubMed

    Chu, W C W; Lam, W W M; Chan, K W; Yeung, C K; Lee, K H; Sihoe, J D Y

    2004-04-01

    To evaluate the use of dynamic gadolinium diethylenetriaminepenta-acetic acid (DTPA)-enhanced magnetic resonance urography (Gd-MRU) for assessing kidneys with markedly dilated pelvicalyceal systems and impaired function. Eight children (mean age 30 months, sd 25) were assessed, diagnosed as having gross unilateral hydronephrosis with a mean (sd) anteroposterior renal pelvic diameter of 36 (7) mm and reduced (30-40%) renal function. Dynamic Gd-MRU was performed after the patients were pre-loaded with intravenous fluid and diuretics, and comprised a dynamic T1-weighted sequence after Gd-DTPA (0.1 mmol/kg body weight) was administered, with a time-intensity curve of each kidney produced. Drainage was diagnosed by a clearly declining time-intensity curve and direct visualization of contrast medium within the ureter in several frames. High-grade or complete obstruction was diagnosed when drainage of contrast medium could not be detected. Gd-MRU results were compared with diuresis radionuclide (mercapto-acetyltriglycine, MAG3) renography within the same week. Unobstructive units detected by Gd-MRU were treated conservatively with a close follow-up by ultrasonography and radionuclide studies. Diuresis MAG3 renography showed drainage in three dilated units and poor washout in five; in contrast, Gd-MRU showed drainage in seven dilated systems (three showed poor washout by MAG3), and obstruction in the remaining case. The unobstructed units detected by MRU under conservative treatment thus showed no further deterioration of renal function or progressive hydronephrosis in the subsequent follow-up (mean 18 months, range 15-23). These preliminary results suggest that dynamic Gd-MRU is a useful noninvasive imaging method in distinguishing obstructive from unobstructive dilated systems, particularly in patients with hydronephrosis and reduced renal function.

  8. Phase correlation imaging of unlabeled cell dynamics

    NASA Astrophysics Data System (ADS)

    Ma, Lihong; Rajshekhar, Gannavarpu; Wang, Ru; Bhaduri, Basanta; Sridharan, Shamira; Mir, Mustafa; Chakraborty, Arindam; Iyer, Rajashekar; Prasanth, Supriya; Millet, Larry; Gillette, Martha U.; Popescu, Gabriel

    2016-09-01

    We present phase correlation imaging (PCI) as a novel approach to study cell dynamics in a spatially-resolved manner. PCI relies on quantitative phase imaging time-lapse data and, as such, functions in label-free mode, without the limitations associated with exogenous markers. The correlation time map outputted in PCI informs on the dynamics of the intracellular mass transport. Specifically, we show that PCI can extract quantitatively the diffusion coefficient map associated with live cells, as well as standard Brownian particles. Due to its high sensitivity to mass transport, PCI can be applied to studying the integrity of actin polymerization dynamics. Our results indicate that the cyto-D treatment blocking the actin polymerization has a dominant effect at the large spatial scales, in the region surrounding the cell. We found that PCI can distinguish between senescent and quiescent cells, which is extremely difficult without using specific markers currently. We anticipate that PCI will be used alongside established, fluorescence-based techniques to enable valuable new studies of cell function.

  9. Computing dynamic classification images from correlation maps.

    PubMed

    Lu, Hongjing; Liu, Zili

    2006-05-22

    We used Pearson's correlation to compute dynamic classification images of biological motion in a point-light display. Observers discriminated whether a human figure that was embedded in dynamic white Gaussian noise was walking forward or backward. Their responses were correlated with the Gaussian noise fields frame by frame, across trials. The resultant correlation map gave rise to a sequence of dynamic classification images that were clearer than either the standard method of A. J. Ahumada and J. Lovell (1971) or the optimal weighting method of R. F. Murray, P. J. Bennett, and A. B. Sekuler (2002). Further, the correlation coefficients of all the point lights were similar to each other when overlapping pixels between forward and backward walkers were excluded. This pattern is consistent with the hypothesis that the point-light walker is represented in a global manner, as opposed to a fixed subset of point lights being more important than others. We conjecture that the superior performance of the correlation map may reflect inherent nonlinearities in processing biological motion, which are incompatible with the assumptions underlying the previous methods.

  10. Phase correlation imaging of unlabeled cell dynamics

    PubMed Central

    Ma, Lihong; Rajshekhar, Gannavarpu; Wang, Ru; Bhaduri, Basanta; Sridharan, Shamira; Mir, Mustafa; Chakraborty, Arindam; Iyer, Rajashekar; Prasanth, Supriya; Millet, Larry; Gillette, Martha U.; Popescu, Gabriel

    2016-01-01

    We present phase correlation imaging (PCI) as a novel approach to study cell dynamics in a spatially-resolved manner. PCI relies on quantitative phase imaging time-lapse data and, as such, functions in label-free mode, without the limitations associated with exogenous markers. The correlation time map outputted in PCI informs on the dynamics of the intracellular mass transport. Specifically, we show that PCI can extract quantitatively the diffusion coefficient map associated with live cells, as well as standard Brownian particles. Due to its high sensitivity to mass transport, PCI can be applied to studying the integrity of actin polymerization dynamics. Our results indicate that the cyto-D treatment blocking the actin polymerization has a dominant effect at the large spatial scales, in the region surrounding the cell. We found that PCI can distinguish between senescent and quiescent cells, which is extremely difficult without using specific markers currently. We anticipate that PCI will be used alongside established, fluorescence-based techniques to enable valuable new studies of cell function. PMID:27615512

  11. Detailing the relation between renal T2* and renal tissue pO2 using an integrated approach of parametric magnetic resonance imaging and invasive physiological measurements.

    PubMed

    Pohlmann, Andreas; Arakelyan, Karen; Hentschel, Jan; Cantow, Kathleen; Flemming, Bert; Ladwig, Mechthild; Waiczies, Sonia; Seeliger, Erdmann; Niendorf, Thoralf

    2014-08-01

    This study was designed to detail the relation between renal T2* and renal tissue pO2 using an integrated approach that combines parametric magnetic resonance imaging (MRI) and quantitative physiological measurements (MR-PHYSIOL). Experiments were performed in 21 male Wistar rats. In vivo modulation of renal hemodynamics and oxygenation was achieved by brief periods of aortic occlusion, hypoxia, and hyperoxia. Renal perfusion pressure (RPP), renal blood flow (RBF), local cortical and medullary tissue pO2, and blood flux were simultaneously recorded together with T2*, T2 mapping, and magnetic resonance-based kidney size measurements (MR-PHYSIOL). Magnetic resonance imaging was carried out on a 9.4-T small-animal magnetic resonance system. Relative changes in the invasive quantitative parameters were correlated with relative changes in the parameters derived from MRI using Spearman analysis and Pearson analysis. Changes in T2* qualitatively reflected tissue pO2 changes induced by the interventions. T2* versus pO2 Spearman rank correlations were significant for all interventions, yet quantitative translation of T2*/pO2 correlations obtained for one intervention to another intervention proved not appropriate. The closest T2*/pO2 correlation was found for hypoxia and recovery. The interlayer comparison revealed closest T2*/pO2 correlations for the outer medulla and showed that extrapolation of results obtained for one renal layer to other renal layers must be made with due caution. For T2* to RBF relation, significant Spearman correlations were deduced for all renal layers and for all interventions. T2*/RBF correlations for the cortex and outer medulla were even superior to those between T2* and tissue pO2. The closest T2*/RBF correlation occurred during hypoxia and recovery. Close correlations were observed between T2* and kidney size during hypoxia and recovery and for occlusion and recovery. In both cases, kidney size correlated well with renal vascular conductance

  12. Automated assessment of renal cortical surface roughness from computerized tomography images and its association with age.

    PubMed

    Duan, Xinhui; Rule, Andrew D; Elsherbiny, Hisham; Vrtiska, Terri J; Avula, Ramesh T; Alexander, Mariam P; Lerman, Lilach O; McCollough, Cynthia H

    2014-11-01

    Nephrosclerosis occurs with aging and is characterized by increased kidney subcapsular surface irregularities at autopsy. Assessments of cortical roughness in vivo could provide an important measure of nephrosclerosis. The purpose of this study was to develop and validate an image-processing algorithm for quantifying renal cortical surface roughness in vivo and determine its association with age. Renal cortical surface roughness was measured on contrast-enhanced abdominal computed tomography (CT) images of potential living kidney donors. A roughness index was calculated based on geometric curvature of each kidney from three-dimensional images and compared to visual observation scores. Cortical roughness was compared between the oldest and youngest donors, and its interaction with cortical volume and age assessed. The developed quantitative roughness index identified significant differences in kidneys with visual surface roughness scores of 0 (minimal), 1 (mild), and 2 (moderate; P < .001) in a random sample of 200 potential kidney donors. Cortical roughness was significantly higher in the 94 oldest (64-75 years) versus 91 youngest (18-25 years) potential kidney donors (P < .001). Lower cortical volume was associated with older age but not with roughness (r = -0.03, P = .75). The association of oldest age group with roughness (odds ratio [OR] = 1.8 per standard deviation [SD] of roughness index) remained significant after adjustment for total cortex volume (OR = 2.0 per SD of roughness index). A new algorithm to measure renal cortical surface roughness from CT scans detected rougher surface in older compared to younger kidneys, independent of cortical volume loss. This novel index may allow quantitative evaluation of nephrosclerosis in vivo using contrast-enhanced CT. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

  13. Automated assessment of renal cortical surface roughness from computerized tomography images and its association with age

    PubMed Central

    Duan, Xinhui; Rule, Andrew D.; Elsherbiny, Hisham E.; Vrtiska, Terri J.; Avula, Ramesh T.; Alexander, Mariam P.; Lerman, Lilach O.; McCollough, Cynthia H.

    2014-01-01

    Rationale and Objectives Nephrosclerosis occurs with aging and is characterized by increased kidney sub-capsular surface irregularities at autopsy. Assessments of cortical roughness in-vivo could provide an important measure of nephrosclerosis. The purpose of this study was to develop and validate an image-processing algorithm for quantifying renal cortical surface roughness in-vivo and determine its association with age. Materials and methods Renal cortical surface roughness was measured on contrast-enhanced abdominal CT images of potential living kidney donors. A roughness index was calculated based on geometric curvature of each kidney from 3D images, and compared with visual observation scores. Cortical roughness was compared between the oldest and youngest donors, and its interaction with cortical volume and age assessed. Results The developed quantitative roughness index identified significant differences in kidneys with visual surface roughness scores of 0 (minimal), 1 (mild), and 2 (moderate) (p<0.001) in a random sample of 200 potential kidney donors. Cortical roughness was significantly higher in the 94 oldest (64–75y) versus 91 youngest (18–25y) potential kidney donors (p<0.001). Lower cortical volume was associated with older age but not with roughness (r=−0.03, p=0.75). The association of oldest age group with roughness (OR=1.8 per SD of roughness index) remained significant after adjustment for total cortex volume (OR=2.0 per SD of roughness index). Conclusion A new algorithm to measure renal cortical surface roughness from CT scans detected rougher surface in older compared to younger kidneys, independent of cortical volume loss. This novel index may allow quantitative evaluation of nephrosclerosis in vivo using contrast-enhanced CT. PMID:25086950

  14. Robust detection of renal calculi from non-contract CT images using TV-flow and MSER features

    NASA Astrophysics Data System (ADS)

    Liu, Jianfei; Wang, Shijun; Linguraru, Marius George; Summers, Ronald M.

    2013-03-01

    Renal calculi are one of the most painful urologic disorders causing 3 million treatments per year in the United States. The objective of this paper is the automated detection of renal calculi from CT colonography (CTC) images on which they are one of the major extracolonic findings. However, the primary purpose of the CTC protocols is not for the detection of renal calculi, but for screening of colon cancer. The kidneys are imaged with significant amounts of noise in the non-contrast CTC images, which makes the detection of renal calculi extremely challenging. We propose a computer-aided diagnosis method to detect renal calculi in CTC images. It is built on three novel techniques: 1) total variation (TV) flow to reduce image noise while keeping calculi, 2) maximally stable extremal region (MSER) features to find calculus candidates, 3) salient feature descriptors based on intensity properties to train a support vector machine classifier and filter false positives. We selected 23 CTC cases with 36 renal calculi to analyze the detection algorithm. The calculus size ranged from 1.0mm to 6.8mm. Fifteen cases were selected as the training dataset, and the remaining eight cases were used for the testing dataset. The area under the receiver operating characteristic curve (AUC) values were 0.92 in the training datasets and 0.93 in the testing datasets. The testing dataset confidence interval for AUC reported by ROCKIT was [0.8799, 0.9591] and the training dataset was [0.8974, 0.9642]. These encouraging results demonstrated that our detection algorithm can robustly and accurately identify renal calculi from CTC images.

  15. 3D texture analysis in renal cell carcinoma tissue image grading.

    PubMed

    Kim, Tae-Yun; Cho, Nam-Hoon; Jeong, Goo-Bo; Bengtsson, Ewert; Choi, Heung-Kook

    2014-01-01

    One of the most significant processes in cancer cell and tissue image analysis is the efficient extraction of features for grading purposes. This research applied two types of three-dimensional texture analysis methods to the extraction of feature values from renal cell carcinoma tissue images, and then evaluated the validity of the methods statistically through grade classification. First, we used a confocal laser scanning microscope to obtain image slices of four grades of renal cell carcinoma, which were then reconstructed into 3D volumes. Next, we extracted quantitative values using a 3D gray level cooccurrence matrix (GLCM) and a 3D wavelet based on two types of basis functions. To evaluate their validity, we predefined 6 different statistical classifiers and applied these to the extracted feature sets. In the grade classification results, 3D Haar wavelet texture features combined with principal component analysis showed the best discrimination results. Classification using 3D wavelet texture features was significantly better than 3D GLCM, suggesting that the former has potential for use in a computer-based grading system.

  16. 3D Texture Analysis in Renal Cell Carcinoma Tissue Image Grading

    PubMed Central

    Cho, Nam-Hoon; Choi, Heung-Kook

    2014-01-01

    One of the most significant processes in cancer cell and tissue image analysis is the efficient extraction of features for grading purposes. This research applied two types of three-dimensional texture analysis methods to the extraction of feature values from renal cell carcinoma tissue images, and then evaluated the validity of the methods statistically through grade classification. First, we used a confocal laser scanning microscope to obtain image slices of four grades of renal cell carcinoma, which were then reconstructed into 3D volumes. Next, we extracted quantitative values using a 3D gray level cooccurrence matrix (GLCM) and a 3D wavelet based on two types of basis functions. To evaluate their validity, we predefined 6 different statistical classifiers and applied these to the extracted feature sets. In the grade classification results, 3D Haar wavelet texture features combined with principal component analysis showed the best discrimination results. Classification using 3D wavelet texture features was significantly better than 3D GLCM, suggesting that the former has potential for use in a computer-based grading system. PMID:25371701

  17. Imaging Renal Urea Handling in Rats at Millimeter Resolution using Hyperpolarized Magnetic Resonance Relaxometry

    PubMed Central

    Reed, Galen D.; von Morze, Cornelius; Verkman, Alan S.; Koelsch, Bertram L.; Chaumeil, Myriam M.; Lustig, Michael; Ronen, Sabrina M.; Bok, Robert A.; Sands, Jeff M.; Larson, Peder E. Z.; Wang, Zhen J.; Larsen, Jan Henrik Ardenkjær; Kurhanewicz, John; Vigneron, Daniel B.

    2016-01-01

    In vivo spin spin relaxation time (T2) heterogeneity of hyperpolarized [13C,15N2]urea in the rat kidney was investigated. Selective quenching of the vascular hyperpolarized 13C signal with a macromolecular relaxation agent revealed that a long-T2 component of the [13C,15N2]urea signal originated from the renal extravascular space, thus allowing the vascular and renal filtrate contrast agent pools of the [13C,15N2]urea to be distinguished via multi-exponential analysis. The T2 response to induced diuresis and antidiuresis was performed with two imaging agents: hyperpolarized [13C,15N2]urea and a control agent hyperpolarized bis-1,1-(hydroxymethyl)-1-13C-cyclopropane-2H8. Large T2 increases in the inner-medullar and papilla were observed with the former agent and not the latter during antidiuresis. Therefore, [13C,15N2]urea relaxometry is sensitive to two steps of the renal urea handling process: glomerular filtration and the inner-medullary urea transporter (UT)-A1 and UT-A3 mediated urea concentrating process. Simple motion correction and subspace denoising algorithms are presented to aid in the multi exponential data analysis. Furthermore, a T2-edited, ultra long echo time sequence was developed for sub-2 mm3 resolution 3D encoding of urea by exploiting relaxation differences in the vascular and filtrate pools. PMID:27570835

  18. Reliability of whole slide images as a diagnostic modality for renal allograft biopsies.

    PubMed

    Jen, Kuang-Yu; Olson, Jean L; Brodsky, Sergey; Zhou, Xin J; Nadasdy, Tibor; Laszik, Zoltan G

    2013-05-01

    The use of digital whole slide images (WSI) in the field of pathology has become feasible for routine diagnostic purposes and has become more prevalent in recent years. This type of technology offers many advantages but must show the same degree of diagnostic reliability as conventional glass slides. Several studies have examined this issue in various settings and indicate that WSI are a reliable method for diagnostic pathology. Since transplant pathology is a highly specialized field that requires not only accurate but rapid diagnostic evaluation of biopsy materials, this field may greatly benefit from the use of WSI. In this study, we assessed the reliability of using WSI compared to conventional glass slides in renal allograft biopsies. We examined morphologic features and diagnostic categories defined by the Banff 07 Classification of Renal Allograft Pathology as well as additional morphologic features not included in this classification scheme. We found that intraobserver scores, when comparing the use of glass slides versus WSI, showed substantial agreement for both morphologic features (κ = 0.68) and acute rejection diagnostic categories (κ = 0.74). Furthermore, interobserver reliability was comparable for morphologic features (κ = 0.44 [glass] vs 0.42 [WSI]) and acute rejection diagnostic categories (κ = 0.49 [glass] vs 0.51 [WSI]). These data indicate that WSI are as reliable as glass slides for the evaluation of renal allograft biopsies.

  19. Management of Renal Tumors by Image-Guided Radiofrequency Ablation: Experience in 105 Tumors

    SciTech Connect

    Breen, David J. Rutherford, Elizabeth E.; Stedman, Brian; Roy-Choudhury, Shuvro H.; Cast, James E. I.; Hayes, Matthew C.; Smart, Christopher J.

    2007-09-15

    Aims. In this article we present our experience with radiofrequency ablation (RFA) in the treatment of 105 renal tumors. Materials and Methods. RFA was performed on 105 renal tumors in 97 patients, with a mean tumor size of 32 mm (11-68 mm). The mean patient age was 71.7 years (range, 36-89 years). The ablations were carried out under ultrasound (n = 43) or CT (n = 62) guidance. Imaging follow-up was by contrast-enhanced CT within 10 days and then at 6-monthly intervals. Multivariate analysis was performed to determine variables associated with procedural outcome. Results. Eighty-three tumors were completely treated at a single sitting (79%). Twelve of the remaining tumors were successfully re-treated and a clinical decision was made not to re-treat seven patients. A patient with a small residual crescent of tumor is under follow-up and may require further treatment. In another patient, re-treatment was abandoned due to complicating pneumothorax and difficult access. One patient is awaiting further re-treatment. The overall technical success rate was 90.5%. Multivariate analysis revealed tumor size to be the only significant variable affecting procedural outcome. (p = 0.007, Pearson {chi}{sup 2}) Five patients had complications. There have been no local recurrences. Conclusion. Our experience to date suggests that RFA is a safe and effective, minimally invasive treatment for small renal tumors.

  20. Management of renal tumors by image-guided radiofrequency ablation: experience in 105 tumors.

    PubMed

    Breen, David J; Rutherford, Elizabeth E; Stedman, Brian; Roy-Choudhury, Shuvro H; Cast, James E I; Hayes, Matthew C; Smart, Christopher J

    2007-01-01

    In this article we present our experience with radiofrequency ablation (RFA) in the treatment of 105 renal tumors. RFA was performed on 105 renal tumors in 97 patients, with a mean tumor size of 32 mm (11-68 mm). The mean patient age was 71.7 years (range, 36-89 years). The ablations were carried out under ultrasound (n = 43) or CT (n = 62) guidance. Imaging follow-up was by contrast-enhanced CT within 10 days and then at 6-monthly intervals. Multivariate analysis was performed to determine variables associated with procedural outcome. Eighty-three tumors were completely treated at a single sitting (79%). Twelve of the remaining tumors were successfully re-treated and a clinical decision was made not to re-treat seven patients. A patient with a small residual crescent of tumor is under follow-up and may require further treatment. In another patient, re-treatment was abandoned due to complicating pneumothorax and difficult access. One patient is awaiting further re-treatment. The overall technical success rate was 90.5%. Multivariate analysis revealed tumor size to be the only significant variable affecting procedural outcome. (p = 0.007, Pearson chi(2)) Five patients had complications. There have been no local recurrences. Our experience to date suggests that RFA is a safe and effective, minimally invasive treatment for small renal tumors.

  1. Diagnostic Accuracy of Multiparametric Magnetic Resonance Imaging to Identify Clear Cell Renal Cell Carcinoma in cT1a Renal Masses.

    PubMed

    Canvasser, Noah E; Kay, Fernando U; Xi, Yin; Pinho, Daniella F; Costa, Daniel; de Leon, Alberto Diaz; Khatri, Gaurav; Leyendecker, John R; Yokoo, Takeshi; Lay, Aaron; Kavoussi, Nicholas; Koseoglu, Ersin; Cadeddu, Jeffrey A; Pedrosa, Ivan

    2017-10-01

    The detection of small renal masses is increasing with the use of cross-sectional imaging, although many incidental lesions have negligible metastatic potential. Among malignant masses clear cell renal cell carcinoma is the most prevalent and aggressive subtype. A method to identify such histology would aid in risk stratification. Our goal was to evaluate a likelihood scale for multiparametric magnetic resonance imaging in the diagnosis of clear cell histology. We retrospectively reviewed the records of patients with cT1a masses who underwent magnetic resonance imaging and partial or radical nephrectomy from December 2011 to July 2015. Seven radiologists with different levels of experience who were blinded to final pathology findings independently reviewed studies based on a predefined algorithm. They applied a clear cell likelihood score, including 1-definitely not, 2-probably not, 3-equivocal, 4-probably and 5-definitely. Binary classification was used to determine the accuracy of clear cell vs all other histologies. Interobserver agreement was calculated with the weighted κ statistic. A total of 110 patients with 121 masses were identified. Mean tumor size was 2.4 cm and 50% of the lesions were clear cell. Defining clear cell as scores of 4 or greater demonstrated 78% sensitivity and 80% specificity while scores of 3 or greater showed 95% sensitivity and 58% specificity. Interobserver agreement was moderate to good with a mean κ of 0.53. A clear cell likelihood score used with magnetic resonance imaging can reasonably identify clear cell histology in small renal masses and may decrease the number of diagnostic renal mass biopsies. Standardization of imaging protocols and reporting criteria is needed to improve interobserver reliability. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  2. Characterization of atypical cystic renal masses with MDCT: comparison of 5-mm axial images and thin multiplanar reconstructed images.

    PubMed

    Bertolotto, Michele; Zappetti, Roberta; Cavallaro, Marco; Perrone, Rosaria; Perretti, Leonardo; Cova, Maria Assunta

    2010-09-01

    The purpose of this study was to investigate whether cystic renal masses are better characterized on thin axial and multiplanar reconstructed MDCT images than on 5-mm images. The records of 70 complex cystic renal masses in 59 patients (45 men, 14 women; mean age, 68 +/- 13 years) who underwent 64-MDCT at two medical centers were studied. Twenty-three of the masses were confirmed on the basis of the histologic findings and 47 in 2-4 years of follow-up. Images were reviewed in two sessions by two radiologists with 12 and 2 years of experience. In the first session, 5-mm axial images were analyzed, and in the second, thin axial images and multiplanar reconstructions. To assess intraobserver variability, analysis was repeated after 1 month. Statistical analysis was performed with Wilcoxon's signed rank test, receiver operating characteristic analysis, and weighted kappa statistics. Radiologists 1 and 2 detected thicker cystic walls (p < 0.001, p < 0.005) and septa (p < 0.03, p < 0.05) and fewer septa (p < 0.005, p < 0.002) on 5-mm axial images and assigned significantly different Bosniak categories than they did in analysis of the volume data (p < 0.04, p < 0.05). Variability was reduced in thin axial and multiplanar views. No significant differences were found in characterization of lesions as benign or malignant in review of 5-mm axial images and volume data sets. The areas under the receiver operating characteristic curve were 0.89 for 5-mm images and 0.96 for volume data sets for radiologist 1 and 0.87 and 0.90 for radiologist 2. Analysis of volume data sets is associated with less intraobserver and interobserver variability than review of 5-mm axial images. Wall thickness and the number and thickness of septa may differ, resulting in assignment of different Bosniak categories. Diagnostic performance in characterizing lesions as benign or malignant, however, is not statistically different for the thick and thin images.

  3. Assessment of renal oxygenation during partial nephrectomy using DLP hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Best, Sara L.; Thapa, Abhas; Holzer, Michael S.; Jackson, Neil; Mir, Saad A.; Donnally, Chester J.; Wehner, Eleanor; Raj, Ganesh V.; Livingston, Edward; Cadeddu, Jeffrey A.; Zuzak, Karel J.

    2011-03-01

    Digital Light Processing (DLP®) hyperspectral imaging (HsI) is a non-invasive method used to construct a highly sensitive, real-time tissue oxygenation map through the measurement of the percentage of oxyhemoglobin. We have demonstrated that this technology can detect the oxyhemoglobin in the blood vessels on the surface of the kidney and we have used this to monitor renal perfusion during kidney cancer operations, where the blood supply to the kidney is interrupted for a period of time. This technology may allow us to "personalize" surgery based on the oxygenation profile.

  4. Renal imaging: a comparison of radionuclide, ultrasound, and computed tomographic scanning in investigation of renal space-occupying lesions.

    PubMed Central

    O'Reilly, P H; Osborn, D E; Testa, H J; Asbury, D L; Best, J J; Barnard, R J

    1981-01-01

    Two studies were carried out in which 27 and 23 patients respectively with renal space-occupying lesions were assessed by different techniques and the results compared. Instead of proceeding to renal arteriography after the lesion had been found on urography, radionuclide and ultrasound scanning were used in the first study to clarify the nature of the lesions, while in the second study computed tomography was used as well. Results were good with all three methods, although ultrasonography and radionuclide scanning cannot resolve lesions of under 2 cm in diameter and the radiation dose with computed tomography is similar to that used in renal arteriography. Probably the best method of evaluating renal space-occupying lesions after urography is to use both ultrasound and radionuclide scanning. If further information is required computed tomography or arteriography is indicated. PMID:6781661

  5. Imaging electric field dynamics with graphene optoelectronics

    PubMed Central

    Horng, Jason; Balch, Halleh B.; McGuire, Allister F.; Tsai, Hsin-Zon; Forrester, Patrick R.; Crommie, Michael F.; Cui, Bianxiao; Wang, Feng

    2016-01-01

    The use of electric fields for signalling and control in liquids is widespread, spanning bioelectric activity in cells to electrical manipulation of microstructures in lab-on-a-chip devices. However, an appropriate tool to resolve the spatio-temporal distribution of electric fields over a large dynamic range has yet to be developed. Here we present a label-free method to image local electric fields in real time and under ambient conditions. Our technique combines the unique gate-variable optical transitions of graphene with a critically coupled planar waveguide platform that enables highly sensitive detection of local electric fields with a voltage sensitivity of a few microvolts, a spatial resolution of tens of micrometres and a frequency response over tens of kilohertz. Our imaging platform enables parallel detection of electric fields over a large field of view and can be tailored to broad applications spanning lab-on-a-chip device engineering to analysis of bioelectric phenomena. PMID:27982125

  6. Imaging electric field dynamics with graphene optoelectronics

    NASA Astrophysics Data System (ADS)

    Horng, Jason; Balch, Halleh B.; McGuire, Allister F.; Tsai, Hsin-Zon; Forrester, Patrick R.; Crommie, Michael F.; Cui, Bianxiao; Wang, Feng

    2016-12-01

    The use of electric fields for signalling and control in liquids is widespread, spanning bioelectric activity in cells to electrical manipulation of microstructures in lab-on-a-chip devices. However, an appropriate tool to resolve the spatio-temporal distribution of electric fields over a large dynamic range has yet to be developed. Here we present a label-free method to image local electric fields in real time and under ambient conditions. Our technique combines the unique gate-variable optical transitions of graphene with a critically coupled planar waveguide platform that enables highly sensitive detection of local electric fields with a voltage sensitivity of a few microvolts, a spatial resolution of tens of micrometres and a frequency response over tens of kilohertz. Our imaging platform enables parallel detection of electric fields over a large field of view and can be tailored to broad applications spanning lab-on-a-chip device engineering to analysis of bioelectric phenomena.

  7. Quantitative biomolecular imaging by dynamic nanomechanical mapping.

    PubMed

    Zhang, Shuai; Aslan, Hüsnü; Besenbacher, Flemming; Dong, Mingdong

    2014-11-07

    The ability to 'see' down to nanoscale has always been one of the most challenging obstacles for researchers to address fundamental questions. For many years, researchers have been developing scanning probe microscopy techniques to improve imaging capability at nanoscale. Among them, atomic force microscopy (AFM) has received considerable attention, which allows probing topography of biological species at real space under physiological environment. Importantly, force measurements in AFM enable researchers to reveal not only the topography but also the relevant physical-chemical properties. AFM-based dynamic nanomechanical mapping (DNM) provides insights into the functions of biological systems by the interpretation of 'force', which are inaccessible by most of the other analytic techniques. This review is aiming to shed light on these recently developed AFM-based DNM techniques for biomolecular imaging, and discuss the relative applications in biological research from the nanomechanical point of view.

  8. NASA's Solar Dynamics Observatory Unveils New Images

    NASA Image and Video Library

    2010-04-20

    Madhulika Guhathakurta, SDO Program Scientist at NASA Headquarters in Washington, speaks during a briefing to discuss recent images from NASA's Solar Dynamics Observatory, or SDO, Wednesday, April 21, 2010, at the Newseum in Washington. Launched on Feb. 11, 2010, SDO is the most advanced spacecraft ever designed to study the sun. During its five-year mission, it will examine the sun's magnetic field and also provide a better understanding of the role the sun plays in Earth's atmospheric chemistry and climate. Photo Credit: (NASA/Carla Cioffi)

  9. Electromagnetic imaging of dynamic brain activity

    SciTech Connect

    Mosher, J.; Leahy, R. . Dept. of Electrical Engineering); Lewis, P.; Lewine, J.; George, J. ); Singh, M. . Dept. of Radiology)

    1991-01-01

    Neural activity in the brain produces weak dynamic electromagnetic fields that can be measured by an array of sensors. Using a spatio-temporal modeling framework, we have developed a new approach to localization of multiple neural sources. This approach is based on the MUSIC algorithm originally developed for estimating the direction of arrival of signals impinging on a sensor array. We present applications of this technique to magnetic field measurements of a phantom and of a human evoked somatosensory response. The results of the somatosensory localization are mapped onto the brain anatomy obtained from magnetic resonance images.

  10. Electromagnetic imaging of dynamic brain activity

    SciTech Connect

    Mosher, J.; Leahy, R.; Lewis, P.; Lewine, J.; George, J.; Singh, M.

    1991-12-31

    Neural activity in the brain produces weak dynamic electromagnetic fields that can be measured by an array of sensors. Using a spatio-temporal modeling framework, we have developed a new approach to localization of multiple neural sources. This approach is based on the MUSIC algorithm originally developed for estimating the direction of arrival of signals impinging on a sensor array. We present applications of this technique to magnetic field measurements of a phantom and of a human evoked somatosensory response. The results of the somatosensory localization are mapped onto the brain anatomy obtained from magnetic resonance images.

  11. ESPR uroradiology task force and ESUR paediatric working group: imaging recommendations in paediatric uroradiology, part IV: Minutes of the ESPR uroradiology task force mini-symposium on imaging in childhood renal hypertension and imaging of renal trauma in children.

    PubMed

    Riccabona, Michael; Lobo, M L; Papadopoulou, F; Avni, F E; Blickman, J G; Dacher, J N; Damasio, B; Darge, K; Ording-Müller, L S; Vivier, P H; Willi, U

    2011-07-01

    Two new recommendations of the European Society of Radiology task force and the European Society of Uroradiology workgroup on paediatric uroradiology are presented. One deals with diagnostic imaging in children after trauma to the urinary tract-renal trauma, in particular. The other concerns the evaluation of suspected renal hypertension. Available data in the paediatric literature are either unsatisfactory or controversial for both of these clinical settings. Therefore, the following consensus-based proposals aim at outlining effective imaging algorithms to reduce invasive imaging procedures while optimising diagnostic accuracy. The objective of following a more uniform imaging approach is to facilitate future meta-analysis as well as multicentre and other more evidence-based studies. The practise in paediatric radiology is typically based on local availability and on the limitations of professional expertise and equipment, balanced against the perceived needs of the individual child. Although this is unlikely to change in the near future, it does not release the physicians in charge of diagnostic imaging from their responsibility in choosing and providing state-of-the-art imaging and management protocols that are adapted specifically for use in children.

  12. Non-invasive Measurement of Renal Blood Flow by Magnetic Resonance Imaging (MRI) in Rats.

    PubMed

    Romero, Cesar A; Cabral, Glauber; Knight, Robert A; Ding, Guangliang; Peterson, Edward L; Carretero, Oscar A

    2017-10-04

    Renal blood flow (RBF) provides important information regarding renal physiology and nephropathies. Arterial spin labeling-magnetic resonance imaging (ASL-MRI) is a non-invasive method of measuring blood flow without exogenous contrast media. However, low signal/noise ratio and respiratory motion artifacts are challenges for RBF measurements in small animals. Our objective was to evaluate the feasibility and reproducibility of RBF measures by ASL-MRI using respiratory-gating and navigator correction methods to reduce motion artifacts. ASL-MRI images were obtained from the kidneys of Sprague-Dawley (SD) rats on a 7 tesla Varian MRI system with a spin-echo imaging sequence. After 4 days, the study was repeated to evaluate its reproducibility. RBF was also measured in animals under unilateral nephrectomy and in renal artery stenosis (RST) to evaluate the sensitivity in high and low RBF models, respectively. RBF was also evaluated in Dahl salt-sensitive (SS) rats and spontaneous hypertensive rats (SHR). In SD rats the cortical RBFs (cRBF) were 305±59 and 271.8±39 ml/min/100 g tissue in the right and left kidneys, respectively. Re-test analysis revealed no differences (p=0.2). The test-retest reliability coefficient was 92±5%. The cRBFs before and after the nephrectomy were 296.8±30 and 428.2±45 ml/min/100 g (p=0.02), respectively. The kidneys with RST exhibited a cRBF decrease compared with sham animals (86±17.6 vs. 198±33.7 ml/min/100 g tissue; p<0.01). The cRBFs in SD, Dahl-ss and SHR rats were not different (p=0.35). We conclude that ASL-MRI performed with navigator correction and respiratory gating is a feasible and reliable non-invasive method for measuring RBF in rats. Copyright © 2017, American Journal of Physiology-Renal Physiology.

  13. Comparison of magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS) in the evaluation of unclear solid renal lesions.

    PubMed

    Rübenthaler, J; Paprottka, K; Marcon, J; Hameister, E; Hoffmann, K; Joiko, N; Reiser, M; Clevert, D A

    2016-01-01

    To compare the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging (MRI) in the evaluation of unclear renal lesions to the histopathological outcome. A total of 36 patients with a single unclear solid renal lesion with initial imaging studies between 2005 and 2015 were included. CEUS and MRI were used for determining malignancy or benignancy and initial findings were correlated with the histopathological outcome. Out of the 36 renal masses a total of 28 lesions were malignant (77.8%) and 8 were found to be benign (22.2%). Diagnostic accuracy was testes by using the histopathological diagnosis as the gold standard. CEUS showed a sensitivity of 96.4%, a specificity of 100.0%, a positive predictive value (PPV) of 100.0% and a negative predictive value (NPV) of 88,9%. MRI showed a sensitivity of 96.4%, a specificity of 75.0%, a PPV of 93.1% and a NPV of 85.7%. Out of the 28 malignant lesions a total of 18 clear cell renal carcinomas, 6 papillary renal cell carcinomas and 4 other malignant lesions, e.g. metastases, were diagnosed. Out of the 8 benign lesions a total 3 angiomyolipomas, 2 oncocytomas, 1 benign renal cyst and 2 other benign lesions, e.g. renal adenomas were diagnosed. Using CEUS, 1 lesion was falsely identified as benign. Using MRI, 2 lesions were falsely identified as benign and 1 lesion was falsely identified as malignant. CEUS is an useful method which can be additionally used to clinically differentiate between malignant and benign renal lesions. CEUS shows a comparable sensitivity, specificity, PPV and NPV to MRI. In daily clinical routine, patients with contraindications for other imaging modalities can particularly benefit using this method.

  14. Induced renal artery stenosis in rabbits: magnetic resonance imaging, angiography, and radionuclide determination of blood volume and blood flow

    SciTech Connect

    Mitchell, D.G.; Tobin, M.; LeVeen, R.; Tomaczewski, J.; Alavi, A.; Staum, M.; Kundel, H.

    1988-03-01

    To investigate the ability of MRI to detect alterations due to renal ischemia, a rabbit renal artery stenosis (RAS) model was developed. Seven rabbits had RAS induced by surgically encircling the artery with a polyethylene band which had a lumen of 1 mm, 1 to 2 weeks prior to imaging. The stenosis was confirmed by angiography, and the rabbits were then imaged in a 1.4 T research MRI unit. T1 was calculated using four inversion recovery sequences with different inversion times. Renal blood flow, using /sup 113/Sn-microspheres, and regional water content by drying were then measured. The average T1 of the inner medulla was shorter for the ischemia (1574 msec) than for the contralateral kidney (1849 msec), while no change ws noted in the cortex. Ischemic kidneys had less distinct outer medullary zones on IR images with TI = 600 msec than did contralateral or control kidneys. Blood flow to both the cortex and medulla were markedly reduced in ischemic kidneys compared with contralateral kidneys (119.5 vs. 391 ml/min/100 gm for cortex and 19.8 vs. 50.8 ml/min/100 gm for medulla). Renal water and blood content were less affected. Our rabbit model of renal artery stenosis with MRI, radionuclide, and angiographic correlation has the potential to increase our understanding of MR imaging of the rabbit kidney.

  15. Texture-learning-based system for three-dimensional segmentation of renal parenchyma in abdominal CT images

    NASA Astrophysics Data System (ADS)

    Peng, Cong-Qi; Chang, Yuan-Hsiang; Wang, Li-Jen; Wong, Yon-Choeng; Chiang, Yang-Jen; Jiang, Yan-Yau

    2009-02-01

    Abdominal CT images are commonly used for the diagnosis of kidney diseases. With the advances of CT technology, processing of CT images has become a challenging task mainly because of the large number of CT images being studied. This paper presents a texture-learning based system for the three-dimensional (3D) segmentation of renal parenchyma in abdominal CT images. The system is designed to automatically delineate renal parenchyma and is based on the texturelearning and the region-homogeneity-based approaches. The first approach is achieved with the texture analysis using the gray-level co-occurrence matrix (GLCM) features and an artificial neural network (ANN) to determine if a pixel in the CT image is likely to fall within the renal parenchyma. The second approach incorporates a two-dimensional (2D) region growing to segment renal parenchyma in single CT image slice and a 3D region growing to propagate the segmentation results to neighboring CT image slices. The criterion for the region growing is a test of region-homogeneity which is defined by examining the ANN outputs. In system evaluation, 10 abdominal CT image sets were used. Automatic segmentation results were compared with manually segmentation results using the Dice similarity coefficient. Among the 10 CT image sets, our system has achieved an average Dice similarity coefficient of 0.87 that clearly shows a high correlation between the two segmentation results. Ultimately, our system could be incorporated in applications for the delineation of renal parenchyma or as a preprocessing in a CAD system of kidney diseases.

  16. Geometry-independent assessment of renal volume in polycystic kidney disease from magnetic resonance imaging.

    PubMed

    Turco, Dario; Severi, Stefano; Mignani, Renzo; Magistroni, Riccardo; Corsi, Cristiana

    2015-01-01

    Total renal volume (TRV) is an important quantitative indicator of the progression of autosomal dominant polycystic kidney disease (ADPKD). The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease proposes a method for TRV computation based on manual tracing and geometric modeling. We developed a fast and nearly-automated technique for kidney segmentation and automatically compute TRV. In this study we aim to compare TRV estimates derived from these two different approaches. The highly-automated technique for the analysis of MR images was tested on 30 ADPKD patients. TRV was computed from both axial and coronal acquisitions, and compared to measurements based on geometric modeling by linear regression and Bland Altman analysis. In addition, to assess reproducibility, intra-observer and inter-observer variabilities were computed. The results of this study provide the feasibility of using a nearly-automated approach for accurate and fast evaluation of TRV also in markedly enlarged ADPKD kidneys.

  17. Preparation and evaluation of (99m)Tc-DMSA lyophilized kit for renal imaging.

    PubMed

    Jan, Syed Umer; Abbass, Hafiz Ghulam

    2013-05-01

    Dimercaptosuccinic acid (DMSA) has been evaluated and used with technetium 99m ((99m)Tc) in imaging of kidneys. DMSA lyophilized kits were prepared and radiolabelled with (99m)Tc. Paper and thin-layer chromatography have been employed using various eluent systems for the radiochemical analysis, percentage labeling and binding capacity of (99m)Tc-DMSA. Female albino rabbits were used for this study. Biological data obtained after intravenous injection of radiolabelled DMSA to female albino rabbits revealed 32.42% uptake and long retention time in the kidneys. On the basis of animal biodistribution data, it is suggested that DMSA when labeled with (99m)Tc is useful complex for renal imaging and can be successfully applied as a diagnostic tool in nuclear medicine. Clinical biodistribution and radiation dosimetry studies are planned in future.

  18. The role of dynamic renal scintigraphy on clinical decision making in hydronephrotic children.

    PubMed

    Çamlar, Seçil Arslansoyu; Deveci, Nazlı; Soylu, Alper; Türkmen, Mehmet Atilla; Özmen, Derya; Çapakaya, Gamze; Kavukçu, Salih

    2017-01-01

    Hydronephrosis may be related to an obstructive cause, ureteropelvic/uretero-vesical junction obstruction or nonobstructive [vesicoureteral reflux (VUR)]. When an obstructive pathology is considered, dynamic renal scintigraphy may help to predict whether it is a true obstruction or not. In this study, we aimed to determine the contribution of dynamic renal scintigraphy with [99] mTc-MAG-3 to the clinical decision-making for surgery in hydronephrotic children. Files of the patients evaluated by MAG-3 scintigraphy for antenatal (AH)/postnatal (PH) hydronephrosis between 1992 and 2014 were reviewed. Gender, age, hydronephrosis (HN) grade by ultrasound (US), presence of VUR, MAG-3 result (obstructive vs. nonobstructive), ultimate diagnosis, and need for surgery were assessed. Cases with double collecting system and neurogenic bladder were excluded from the study. All of the patients had normal serum creatinine and eGFR. There were a total of 178 patients with 218 hydronephrotic renal units (mean age 34.7 ± 52.7 months; male/ female = 121/57, AH of 62%). MAG-3 was nonobstructive in 134 and obstructive in 84 hydronephrotic renal units. MAG-3 was obstructive in 47 of 121 (39%) males and 30 of 57 (53%) females (P = 0.058, odds ratio (OR) for obstruction was 1.9 for girls). MAG-3 was obstructive in 47 of 135 (35%) units with AH and 37 of 83 (45%) units with PH (P = 0.137). In 81 units with the society of fetal urology-4 HN by US, MAG-3 was obstructive in 55 (68%), and surgery was required in 52 of 55 (95%). Surgery was required for only two (7%) of the remaining 26 units with nonobstructive dilatation (P <0.001, sensitivity 96%, specificity 89%, OR 208). Antero-posterior diameter >16.5 mm was the best cutoff level for predicting obstruction by MAG-3 (sensitivity 75.2%; specificity 71%; OR 3.8). MAG-3 significantly affects clinical decision for surgery in HN. Hydronephrotic girls have more risk in terms of true obstruction. Combining MAG-3 with US improves the

  19. Reproducibility and interobserver agreement of the R.E.N.A.L. nephrometry score: focus on imaging features

    PubMed Central

    Vilaseca, Richard Mast; Westphalen, Antonio Carlos; Reis, Henrique Ferreira; Zogbi, Orlando Salomão; Silva, Gyl Eanes; dos Reis, Rodolfo Borges; Muglia, Valdair Francisco

    2017-01-01

    Objective To investigate the reproducibility and interobserver agreement for R.E.N.A.L. nephrometry scoring system. Materials and Methods Two independent radiologists retrospectively analyzed 46 consecutive patients with renal masses, between 2008 and 2012, using the R.E.N.A.L. nephrometry score (RENAL-NS), which is based on the evaluation of five anatomical features of the tumor, as evaluated with computed tomography or magnetic resonance imaging: Radius, Exophytic/endophytic properties, Nearness to the collecting system, Anterior or posterior descriptor, and Location relative to the polar line. Tumor complexity was graded as low, intermediate, or high. The interobserver agreement was calculated for the total score and for the score for each parameter. Surgical excision of the tumors was used as the standard of reference. Results The interobserver agreement for each of the RENAL-NS parameters, respectively, a hilar location, and the total score was 98%, 80%, 100%, 89%, 85%, 89%, and 93% of patients, corresponding to kappa values of 0.96, 0.65, 1.00, 0.75, 0.72, 0.78, and 0.88, respectively. The Nearness, Radius, and total score showed the best agreement. For the cases that were discordant in terms of the final score, no major implications in surgical planning were observed. Conclusion The RENAL-NS is a structured, useful system to assess the anatomical features of renal tumors. It is easily applicable and reproducible, even for less experienced radiologists. PMID:28298726

  20. Fetal and Postnatal Magnetic Resonance Imaging of Unilateral Cystic Renal Dysplasia in a Neonate with Tuberous Sclerosis.

    PubMed

    Tyagi, Vineet; Bornstein, Eran; Schacht, Robert; Lala, Shailee; Milla, Sarah

    2016-10-01

    Tuberous sclerosis (TS) is an autosomal dominant condition associated with mutations in the TSC1 and/or TSC2 genes. Clinical manifestations are multisystemic, and they often include lesions in the brain, skin, heart, kidneys, and bones. TSC2 gene mutations can be seen concomitantly with autosomal dominant polycystic kidney disease gene mutations. We present a case of a fetus with prenatal diagnosis of TS that had unique asymmetrical distribution of renal cystic disease. We describe the extensive work up with both fetal and neonatal magnetic resonance imaging with correlating images of the unilateral polycystic renal disease in addition to typical TS brain findings.

  1. Imaging Collective Dynamics in the Neocortex

    NASA Astrophysics Data System (ADS)

    Bahar, Sonya

    2005-03-01

    Central to understanding collective neural dynamics is the problem of obtaining spatiotemporal data which reveals the collective behavior of neural ensembles; this can be done either through multi-contact recordings or through various imaging modalities. As an example of both the power and limitations of imaging techniques, we consider the onset, spread, and termination of focal seizures, imaged using the intrinsic optical signal (IOS). The IOS is a change in light reflectance from neural tissue that correlates with the underlying electrophysiological activity. With incident light in the green range, the IOS reflects changes in blood volume (CBV signal); for incident light in the orange range, the IOS shows a change in the oxygenation state of hemoglobin (Hbr signal), and can be correlated with the BOLD (blood oxygen level dependent) fMRI signal; for incident red light, the IOS reflects changes in cell volume and/or light scattering (LS signal). Using the IOS to image the spread of focal neocortical seizures induced by 4-aminopyridine in the rat, we found that the CBV, Hbr and LS signals were equally useful in localizing the ictal onset. We found a focal, profound dip in hemoglobin oxygenation (Hbr signal) during the entire seizure duration, implying that brain perfusion is inadequate to meet the metabolic demands of an epileptic focus. We observed significant variability in the spatial distribution of the active region during seizure termination. However, the IOS was unable to resolve electrophysiologically distinct patterns of seizure onset and the signal, at all incident wavelengths, persisted long after seizure termination.

  2. Imaging of renal medullary carcinoma in children and young adults: a report from the Children's Oncology Group.

    PubMed

    Sandberg, Jesse K; Mullen, Elizabeth A; Cajaiba, Mariana M; Smith, Ethan A; Servaes, Sabah; Perlman, Elizabeth J; Geller, James I; Ehrlich, Peter F; Cost, Nicholas G; Dome, Jeffrey S; Fernandez, Conrad V; Khanna, Geetika

    2017-07-08

    Renal medullary carcinoma is a rare renal malignancy of childhood. There are no large series describing the imaging appearance of renal medullary carcinoma in children. To characterize the clinical and imaging features of pediatric renal medullary carcinoma at initial presentation. We retrospectively analyzed images of 25 pediatric patients with renal medullary carcinoma enrolled in the Children's Oncology Group renal tumors classification, biology and banking study (AREN03B2) from March 2006 to August 2016. Imaging findings of the primary mass, and patterns of locoregional and distant spread were evaluated in correlation with pathological and surgical findings. Median age at presentation was 13 years (range: 6-21 years), with a male predominance (3.2:1). The overall stage of disease at initial presentation was stage 1 in 1, stage 2 in 2 and stage 4 in 22. Maximum diameter of the primary renal mass ranged from 1.6 to 10.3 cm (mean: 6.6 cm) with a slight right side predilection (1.5:1). Enlarged (>1 cm short axis) retroperitoneal lymph nodes were identified at initial staging in 20/25 (80%) cases, 10 of which were histologically confirmed while the others did not undergo surgical sampling. Enlarged lymph nodes were also identified in the mediastinum (14/25; 56%) and supraclavicular regions (4/25; 16%). Metastatic disease was present in the lungs in 19/25 (76%) and liver in 6/25 (24%). The pattern of lung metastases was pulmonary lymphangitic carcinomatosis: 10 cases (9 bilateral, 1 unilateral), pulmonary nodules with indistinct margins: 6 cases, pulmonary nodules with distinct margins: 2 cases, while 1 case had pulmonary nodules with both indistinct and distinct margins. Pulmonary lymphangitic carcinomatosis was pathologically confirmed in 4/10 cases. All cases with pulmonary lymphangitic carcinomatosis had associated enlarged mediastinal lymph nodes. Renal medullary carcinoma in children and young adults presents at an advanced local and distant stage in the

  3. [Renal arterial spin labeling magnetic resonance imaging in normal adults: a study with a 3.0 T scanner].

    PubMed

    Zhang, Fan; Zhang, Xuelin; Yang, Li; Shen, Jie; Gao, Wei

    2013-10-01

    To analyze the renal relative blood flow value (rBFV) and image quality in normal adults using single-shot fast spin echo, flow sensitive invention recovery (SSFSE-FAIR) magnetic resonance (MR) sequence and echo planar imaging, and flow sensitive invention recovery (EPI-FAIR) MR sequence, and assess its value for clinical application in routine renal examination. Forty volunteers (25 male and 15 female adults, aged 30 to 62 years) with normal renal function were included in this prospective study. All the subjects underwent 3.0 Tesla MR scanning using 3 MR scan modes, namely breath-holding EPI-FAIR, breath-holding SSFSE-FAIR and free breathing SSFSE-FAIR. SSFSE-FAIR without breath-holding was capable of differentiating the renal cortex and medulla with the corresponding rBFVs of 111.48∓9.23 and 94.98∓3.38, respectively. Breath-holding SSFSE-FAIR and EPI-FAIR failed to distinguish the borders of the renal cortex and medulla. The EPI-FAIR rBFV of mixed cortex and medulla value was 178.50∓17.17 (95%CI: 167.59, 189.41). Breath-holding SSFSE-FAIR and EPI-FAIR can not distinguish the renal cortex and medulla due to a poor spatial resolution but can be used for rough evaluation of renal blood perfusion. Free breathing SSFSE-FAIR with an improved spatial resolution allows evaluation of the status of renal perfusion of the cortex and medulla.

  4. Dynamical diffraction artifacts in Laue microdiffraction images

    NASA Astrophysics Data System (ADS)

    Yan, Hanfei; Noyan, I. C.

    2005-10-01

    Back-reflection images obtained from single-crystal semiconductor substrates using Laue microdiffraction with medium-to-high energy x rays (10-30 keV) may contain double spots, one strong and one weak, for the higher-energy reflections. Some of the weaker spots originate from the back surface of the sample and are due to dynamic diffraction from a finite crystal. Others may be due to epitaxial thin films on the substrate. The intensity and position of the back-surface peaks depend on the x-ray energy, sample characteristics, and diffraction geometry. We provide a set of simple equations that can be used to calculate the separation of such peak pairs. These equations can be used to identify the peaks from the back surface of the sample.

  5. Imaging via complete cantilever dynamic detection: General dynamic mode imaging and spectroscopy in scanning probe microscopy

    SciTech Connect

    Somnath, Suhas; Collins, Liam; Matheson, Michael A.; Sukumar, Sreenivas R.; Kalinin, Sergei V.; Jesse, Stephen

    2016-09-08

    We develop and implement a multifrequency spectroscopy and spectroscopic imaging mode, referred to as general dynamic mode (GDM), that captures the complete spatially- and stimulus dependent information on nonlinear cantilever dynamics in scanning probe microscopy (SPM). GDM acquires the cantilever response including harmonics and mode mixing products across the entire broadband cantilever spectrum as a function of excitation frequency. GDM spectra substitute the classical measurements in SPM, e.g. amplitude and phase in lock-in detection. Here, GDM is used to investigate the response of a purely capacitively driven cantilever. We use information theory techniques to mine the data and verify the findings with governing equations and classical lock-in based approaches. We explore the dependence of the cantilever dynamics on the tip–sample distance, AC and DC driving bias. This approach can be applied to investigate the dynamic behavior of other systems within and beyond dynamic SPM. In conclusion, GDM is expected to be useful for separating the contribution of different physical phenomena in the cantilever response and understanding the role of cantilever dynamics in dynamic AFM techniques.

  6. Imaging via complete cantilever dynamic detection: general dynamic mode imaging and spectroscopy in scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Somnath, Suhas; Collins, Liam; Matheson, Michael A.; Sukumar, Sreenivas R.; Kalinin, Sergei V.; Jesse, Stephen

    2016-10-01

    We develop and implement a multifrequency spectroscopy and spectroscopic imaging mode, referred to as general dynamic mode (GDM), that captures the complete spatially- and stimulus dependent information on nonlinear cantilever dynamics in scanning probe microscopy (SPM). GDM acquires the cantilever response including harmonics and mode mixing products across the entire broadband cantilever spectrum as a function of excitation frequency. GDM spectra substitute the classical measurements in SPM, e.g. amplitude and phase in lock-in detection. Here, GDM is used to investigate the response of a purely capacitively driven cantilever. We use information theory techniques to mine the data and verify the findings with governing equations and classical lock-in based approaches. We explore the dependence of the cantilever dynamics on the tip–sample distance, AC and DC driving bias. This approach can be applied to investigate the dynamic behavior of other systems within and beyond dynamic SPM. GDM is expected to be useful for separating the contribution of different physical phenomena in the cantilever response and understanding the role of cantilever dynamics in dynamic AFM techniques.

  7. Imaging via complete cantilever dynamic detection: General dynamic mode imaging and spectroscopy in scanning probe microscopy

    SciTech Connect

    Somnath, Suhas; Collins, Liam; Matheson, Michael A.; Sukumar, Sreenivas R.; Kalinin, Sergei V.; Jesse, Stephen

    2016-09-08

    We develop and implement a multifrequency spectroscopy and spectroscopic imaging mode, referred to as general dynamic mode (GDM), that captures the complete spatially- and stimulus dependent information on nonlinear cantilever dynamics in scanning probe microscopy (SPM). GDM acquires the cantilever response including harmonics and mode mixing products across the entire broadband cantilever spectrum as a function of excitation frequency. GDM spectra substitute the classical measurements in SPM, e.g. amplitude and phase in lock-in detection. Here, GDM is used to investigate the response of a purely capacitively driven cantilever. We use information theory techniques to mine the data and verify the findings with governing equations and classical lock-in based approaches. We explore the dependence of the cantilever dynamics on the tip–sample distance, AC and DC driving bias. This approach can be applied to investigate the dynamic behavior of other systems within and beyond dynamic SPM. In conclusion, GDM is expected to be useful for separating the contribution of different physical phenomena in the cantilever response and understanding the role of cantilever dynamics in dynamic AFM techniques.

  8. Imaging via complete cantilever dynamic detection: General dynamic mode imaging and spectroscopy in scanning probe microscopy

    DOE PAGES

    Somnath, Suhas; Collins, Liam; Matheson, Michael A.; ...

    2016-09-08

    We develop and implement a multifrequency spectroscopy and spectroscopic imaging mode, referred to as general dynamic mode (GDM), that captures the complete spatially- and stimulus dependent information on nonlinear cantilever dynamics in scanning probe microscopy (SPM). GDM acquires the cantilever response including harmonics and mode mixing products across the entire broadband cantilever spectrum as a function of excitation frequency. GDM spectra substitute the classical measurements in SPM, e.g. amplitude and phase in lock-in detection. Here, GDM is used to investigate the response of a purely capacitively driven cantilever. We use information theory techniques to mine the data and verify themore » findings with governing equations and classical lock-in based approaches. We explore the dependence of the cantilever dynamics on the tip–sample distance, AC and DC driving bias. This approach can be applied to investigate the dynamic behavior of other systems within and beyond dynamic SPM. In conclusion, GDM is expected to be useful for separating the contribution of different physical phenomena in the cantilever response and understanding the role of cantilever dynamics in dynamic AFM techniques.« less

  9. Review of Source Images is Necessary for the Evaluation of Gadolinium-Enhanced MR Angiography for Renal Artery Stenosis

    SciTech Connect

    Wehrschuetz, M. Aschauer, M.; Portugaller, H.; Stix, A.; Wehrschuetz-Sigl, E.; Hausegger, K.; Ebner, F.

    2004-09-15

    The purpose of this study was to assess interobserver variability and accuracy in the evaluation of renal artery stenosis (RAS) with gadolinium-enhanced MR angiography (MRA) and digital subtraction angiography (DSA) in patients with hypertension. The authors found that source images are more accurate than maximum intensity projection (MIP) for depicting renal artery stenosis. Two independent radiologists reviewed MRA and DSA from 38 patients with hypertension. Studies were postprocessed to display images in MIP and source images. DSA was the standard for comparison in each patient. For each main renal artery, percentage stenosis was estimated for any stenosis detected by the two radiologists. To calculate sensitivity, specificity and accuracy, MRA studies and stenoses were categorized as normal, mild (1-39%), moderate (40-69%) or severe ({>=}70%), or occluded. DSA stenosis estimates of 70% or greater were considered hemodynamically significant. Analysis of variance demonstrated that MIP estimates of stenosis were greater than source image estimates for both readers. Differences in estimates for MIP versus DSA reached significance in one reader. The interobserver variance for MIP, source images and DSA was excellent (0.80< {kappa}{<=} 0.90). The specificity of source images was high (97%) but less for MIP (87%); average accuracy was 92% for MIP and 98% for source images. In this study, source images are significantly more accurate than MIP images in one reader with a similar trend was observed in the second reader. The interobserver variability was excellent. When renal artery stenosis is a consideration, high accuracy can only be obtained when source images are examined.

  10. Radiowave Imaging of Ionospheric Electron Dynamics

    NASA Astrophysics Data System (ADS)

    van Bavel, Gregory Hugh

    1998-12-01

    This dissertation is a study of disturbances in the polar ionosphere. A relative ionospheric opacity meter (riometer) is a radio frequency instrument that enables the remote sensing of ionospheric disturbances by recording variations in the cosmic radio noise power received at a terrestrial antenna. The Imaging Riometer for Ionospheric Studies (IRIS) produces images of relative ionospheric opacity. In the ionosphere, the attenuation of a radio signal's amplitude is proportional to the electron number density n and the effective collision frequency ν. Therefore, a riometer is sensitive to variations of the product n/nu, but their effects are not separated. The theory of HF radiowave attenuation in a cold magetoplasma and electron continuity yield a pair of uni-directional wave equations that couple the dynamics of cosmic radio noise absorption to the vertical mean value of ν. These equations, and some simplifying assumptions, are the basis of a data analysis that transforms IRIS images into physical quantities related to the absorbing ionospheric electrons: mean velocity, mean effective collision frequency, net production rate and column density. A critical test case and coincident auroral observations support the reliability of the general results of the data analysis. Variations in the mean flow velocity indicate that the ionosphere is not in equilibrium. The mean effective collision frequency shows significant structural variations over 100 km and 1 minute intervals. Column density depletions lead enhancements in a geomagnetic poleward drift, while a net production region moves with the column density enhancement and intensifies as the pole-ward motion ceases. Regions of persistent electron production or loss are found where the collision frequency is relatively low, and specific locations can oscillate between net production and loss with periods of about 1 to 2 minutes. It is found that the spatial structure of a riometer image is chiefly determined by the

  11. Improvement in dynamic magnetic resonance imaging thermometry

    NASA Astrophysics Data System (ADS)

    Guo, Jun-Yu

    This dissertation is focused on improving MRI Thermometry (MRIT) techniques. The application of the spin-lattice relaxation constant is investigated in which T1 is used as indicator to measure the temperature of flowing fluid such as blood. Problems associated with this technique are evaluated, and a new method to improve the consistency and repeatability of T1 measurements is presented. The new method combines curve fitting with a measure of the curve null point to acquire more accurate and consistent T1 values. A novel method called K-space Inherited Parallel Acquisition (KIPA) is developed to achieve faster dynamic temperature measurements. Localized reconstruction coefficients are used to achieve higher reduction factors, and lower noise and artifact levels compared to that of GeneRalized Autocalibrating Partially Parallel Acquisition (GRAPPA) reconstruction. Artifacts in KIPA images are significantly reduced, and SNR is largely improved in comparison with that in GRAPPA images. The Root-Mean-Square (RMS) error of temperature for GRAPPA is 2 to 5 times larger than that for KIPA. Finally, the accuracy and comparison of the effects of motion on three parallel imaging methods: SENSE (SENSitivity Encoding), VSENSE (Variable-density SENSE) and KIPA are estimated. According to the investigation, KIPA is the most accurate and robust method among all three methods for studies with or without motion. The ratio of the normalized RMS (NRMS) error for SENSE to that for KIPA is within the range from 1 to 3.7. The ratio of the NRMS error for VSENSE to that for KIPA is about 1 to 2. These factors change with the reduction factor, motion and subject. In summary, the new strategy and method for the fast noninvasive measurement of T1 of flowing blood are proposed to improve stability and precision. The novel parallel reconstruction algorithm, KIPA, is developed to improve the temporal and spatial resolution for the PRF method. The motion effects on the KIPA method are also

  12. Emerging role of high-resolution imaging in the detection of renal osteodystrophy.

    PubMed

    Sharma, Ashish K; Masterson, Rosemary; Holt, Stephen G; Toussaint, Nigel D

    2016-10-01

    The term renal osteodystrophy refers to changes in bone morphology induced by chronic kidney disease (CKD) and represents the skeletal component of the entity 'chronic kidney disease - mineral and bone disorder'. Changes in turnover, mineralization, mass and microarchitecture impair bone quality, compromising strength and increasing susceptibility to fractures. Fractures are more common in CKD compared with the general population and result in increased morbidity and mortality. Screening for fracture risk and management of renal osteodystrophy are hindered by the complex, and still only partially understood, pathophysiology and the inadequacy of currently available diagnostic methods. Bone densitometry and bone turnover markers, although potentially helpful, have significant limitations in patients with CKD, and the 'gold standard' test of bone biopsy is infrequently performed in routine clinical practice. However, recent advances in high-resolution bone microarchitecture imaging may offer greater potential for quantification and assessment of bone structure and strength and, when used in conjunction with serum biomarkers, may allow non-invasive testing for a diagnostic virtual bone biopsy. © 2016 Asian Pacific Society of Nephrology.

  13. Renal Scintigraphy

    MedlinePlus

    ... size with caption Related Articles and Media General Nuclear Medicine Radiation Dose in X-Ray and CT Exams X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Renal Scintigraphy Sponsored by ...

  14. Detection of Renal Stones on Portal Venous Phase CT: Comparison of Thin Axial and Coronal Maximum-Intensity-Projection Images.

    PubMed

    Corwin, Michael T; Lee, Justin S; Fananapazir, Ghaneh; Wilson, Machelle; Lamba, Ramit

    2016-12-01

    The objective of our study was to determine the sensitivity of thin axial and coronal maximum-intensity-projection (MIP) images for the detection of renal stones on contrast-enhanced CT performed in the portal venous phase. This retrospective study included 72 patients, 59 of whom had at least one renal stone, who underwent unenhanced CT immediately followed by contrast-enhanced CT in the portal venous phase. Two abdominal imaging fellowship-trained radiologists independently recorded the number of stones on both thin (1-1.50 mm) axial and 5-mm coronal MIP images in the portal venous phase. The reference standard was determined by consensus review of the thin axial unenhanced images. Reviewer sensitivity was calculated and categorized by stone diameter. One hundred forty-eight stones were present; the mean number of stones per patient was 2.5 (SD, 2.7). The mean stone size was 2.5 mm (SD, 2.7). The sensitivity of thin axial images was 89.9%, 99.0%, and 100.0% for reviewer 1 and 83.1%, 98.0%, and 100.0% for reviewer 2 for all stones, stones ≥ 2 mm, and stones ≥ 3 mm, respectively. The sensitivity of coronal MIP images was 86.5%, 96.2%, and 100.0% for reviewer 1 and 79.0%, 91.4%, and 96.6% for reviewer 2 for all stones, stones ≥ 2 mm, and stones ≥ 3 mm, respectively. Thin axial images are highly sensitive for the detection of renal stones ≥ 2 mm on portal venous phase CT. Coronal MIP images do not improve renal stone detection over thin axial images.

  15. Computed Tomography Perfusion, Magnetic Resonance Imaging, and Histopathological Findings After Laparoscopic Renal Cryoablation: An In Vivo Pig Model.

    PubMed

    Nielsen, Tommy Kjærgaard; Østraat, Øyvind; Graumann, Ole; Pedersen, Bodil Ginnerup; Andersen, Gratien; Høyer, Søren; Borre, Michael

    2017-08-01

    The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention, each animal was randomized to a postoperative follow-up period of 1, 2, or 4 weeks, after which computed tomography perfusion and magnetic resonance imaging scans were performed. Immediately after imaging, open bilateral nephrectomy was performed allowing for histopathological examination of the cryolesions. On computed tomography perfusion and magnetic resonance imaging examinations, rim enhancement was observed in the transition zone of the cryolesion 1week after laparoscopic-assisted cryoablation. This rim enhancement was found to subside after 2 and 4 weeks of follow-up, which was consistent with the microscopic examinations revealing of fibrotic scar tissue formation in the peripheral zone of the cryolesion. On T2 magnetic resonance imaging sequences, a thin hypointense rim surrounded the cryolesion, separating it from the adjacent renal parenchyma. Microscopic examinations revealed hemorrhage and later hemosiderin located in the peripheral zone. No nodular or diffuse contrast enhancement was found in the central zone of the cryolesions at any follow-up stage on neither computed tomography perfusion nor magnetic resonance imaging. On microscopic examinations, the central zone was found to consist of coagulative necrosis 1 week after laparoscopic-assisted cryoablation, which was partially replaced by fibrotic scar tissue 4 weeks following laparoscopic-assisted cryoablation. Both computed tomography perfusion and magnetic resonance imaging found the renal collecting system to be involved at all 3 stages of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma

  16. Dynamic imaging through turbid media based on digital holography.

    PubMed

    Li, Shiping; Zhong, Jingang

    2014-03-01

    Imaging through turbid media using visible or IR light instead of harmful x ray is still a challenging problem, especially in dynamic imaging. A method of dynamic imaging through turbid media using digital holography is presented. In order to match the coherence length between the dynamic object wave and the reference wave, a cw laser is used. To solve the problem of difficult focusing in imaging through turbid media, an autofocus technology is applied. To further enhance the image contrast, a spatial filtering technique is used. A description of digital holography and experiments of imaging the objects hidden in turbid media are presented. The experimental result shows that dynamic images of the objects can be achieved by the use of digital holography.

  17. Three new renal simulators for use in nuclear medicine

    NASA Astrophysics Data System (ADS)

    Dullius, Marcos; Fonseca, Mateus; Botelho, Marcelo; Cunha, Clêdison; Souza, Divanízia

    2014-03-01

    Renal scintigraphy is useful to provide both functional and anatomic information of renal flow of cortical functions and evaluation of pathological collecting system. The objective of this study was develop and evaluate the performance of three renal phantoms: Two anthropomorphic static and another dynamic. The static images of the anthropomorphic phantoms were used for comparison with static renal scintigraphy with 99mTc-DMSA in different concentrations. These static phantoms were manufactured in two ways: one was made of acrylic using as mold a human kidney preserved in formaldehyde and the second was built with ABS (acrylonitrile butadiene styrene) in a 3D printer. The dynamic renal phantom was constructed of acrylic to simulate renal dynamics in scintigraphy with 99mTc-DTPA. These phantoms were scanned with static and dynamic protocols and compared with clinical data. Using these phantoms it is possible to acquire similar renal images as in the clinical scintigraphy. Therefore, these new renal phantoms can be very effective for use in the quality control of renal scintigraphy, and image processing systems.

  18. Shape-based motion correction in dynamic contrast-enhanced MRI for quantitative assessment of renal function.

    PubMed

    Liu, Wenyang; Sung, Kyunghyun; Ruan, Dan

    2014-12-01

    To incorporate a newly developed shape-based motion estimation scheme into magnetic resonance urography (MRU) and verify its efficacy in facilitating quantitative functional analysis. The authors propose a motion compensation scheme in MRU that consists of three sequential modules: MRU image acquisition, motion compensation, and quantitative functional analysis. They designed two sets of complementary experiments to evaluate the performance of the proposed method. In the first experiment, dynamic contrast enhanced (DCE) MR images were acquired from three sedated subjects, from which clinically valid estimates were derived and served as the "ground truth." Physiologically sound motion was then simulated to synthesize image sequences influenced by respiratory motion. Quantitative assessment and comparison were performed on functional estimates of Patlak number, glomerular filtration rate, and Patlak differential renal function without and with motion compensation against the ground truth. In the second experiment, the authors acquired a temporal series of noncontrast MR images under free breathing from a healthy adult subject. The performance of the proposed method on compensating real motion was evaluated by comparing the standard deviation of the obtained temporal intensity curves before and after motion compensation. On DCE-MR images with simulated motion, the generated relative enhancement curves exhibited large perturbations and the Patlak numbers of the left and right kidney were significantly underestimated up to 35% and 34%, respectively, compared with the ground truth. After motion compensation, the relative enhancement curves exhibited much less perturbations and Patlak estimation errors reduced within 3% and 4% for the left and right kidneys, respectively. On clinical free-breathing MR images, the temporal intensity curves exhibited significantly reduced variations after motion compensation, with standard deviation decreased from 30.3 and 38.2 to 8.3 and

  19. Shape-based motion correction in dynamic contrast-enhanced MRI for quantitative assessment of renal function

    PubMed Central

    Liu, Wenyang; Sung, Kyunghyun; Ruan, Dan

    2014-01-01

    Purpose: To incorporate a newly developed shape-based motion estimation scheme into magnetic resonance urography (MRU) and verify its efficacy in facilitating quantitative functional analysis. Methods: The authors propose a motion compensation scheme in MRU that consists of three sequential modules: MRU image acquisition, motion compensation, and quantitative functional analysis. They designed two sets of complementary experiments to evaluate the performance of the proposed method. In the first experiment, dynamic contrast enhanced (DCE) MR images were acquired from three sedated subjects, from which clinically valid estimates were derived and served as the “ground truth.” Physiologically sound motion was then simulated to synthesize image sequences influenced by respiratory motion. Quantitative assessment and comparison were performed on functional estimates of Patlak number, glomerular filtration rate, and Patlak differential renal function without and with motion compensation against the ground truth. In the second experiment, the authors acquired a temporal series of noncontrast MR images under free breathing from a healthy adult subject. The performance of the proposed method on compensating real motion was evaluated by comparing the standard deviation of the obtained temporal intensity curves before and after motion compensation. Results: On DCE-MR images with simulated motion, the generated relative enhancement curves exhibited large perturbations and the Patlak numbers of the left and right kidney were significantly underestimated up to 35% and 34%, respectively, compared with the ground truth. After motion compensation, the relative enhancement curves exhibited much less perturbations and Patlak estimation errors reduced within 3% and 4% for the left and right kidneys, respectively. On clinical free-breathing MR images, the temporal intensity curves exhibited significantly reduced variations after motion compensation, with standard deviation decreased

  20. [Application of diffusion-weighted intravoxel incoherent motion imaging in diagnosis of renal cell carcinoma subtypes].

    PubMed

    Cong, X Y; Chen, Y; Zhang, J; Yu, X D; Ye, F; Yu, W J; Zhang, M M; Ouyang, H; Zhao, X M

    2016-06-23

    To evaluate the value of parameters derived from intravoxel incoherent motion diffusion-weighted magnetic resonance imaging in differentiating histopathological subtypes of renal cell carcinoma (RCC). Between May 2014 and December 2015, a total of 69 patients who were surgically and pathologically diagnosed as renal cell carcinoma were recruited for the study. We examined 61 clear cell RCC (ccRCC), and 8 non-clear cell carcinoma (non-ccRCC, including 7 chromophobe RCC and 1 papillary RCC). All the ccRCC were divided into well differentiated group (n=46), moderately differentiated group (n=8), and poorly differentiated group (n=7). In addition to routine renal magnetic resonance imaging examination performed on a 3.0-Tesla MR system, all patients were imaged with axial intravoxel incoherent motion diffusion-weighted imaging. Using biexponential model, we calculated the diffusion coefficient (D), pseudodiffusion coefficient (D(*)), and perfusion fraction (f). The D and f values of the ccRCC were higher (each P<0.05) than that for non-ccRCC [D (1.29±0.30)×10(-3)mm(2)/s, D(*) (42.92±20.21)×10(-3)mm(2)/s, and f (35.71±6.61)% versus D (0.78±0.23)×10(-3)mm(2)/s, D(*) (32.60±11.33)×10(-3)mm(2)/s, and f (21.52±8.44)% ]. In the well differentiated group of ccRCC, we found D of (1.36±0.29)×10(-3)mm(2)/s, D(*) (38.39±18.51)×10(-3)mm(2)/s, and f (36.40±6.96)%. The D, D(*,) f values of moderately differentiated lesions were (1.10±0.24)×10(-3)mm(2)/s, (59.90±20.23)×10(-3) mm(2)/s, and (32.88±4.02)%, respectively, those of the poorly differentiated group were (1.03±0.16)×10(-3)mm(2)/s, (53.28±18.74)×10(-3)mm(2)/s, and (34.42±6.21)%. The well differentiated group of ccRCC showed a higher D value than the moderately differentiated and poorly differentiated groups (each P<0.05). D(*) values were significantly lower for the well differentiated group than for the moderately differentiated group (P<0.05). The sensitivity and specificity of D values were 90

  1. Arterial Spin-labeling MR Imaging of Renal Masses: Correlation with Histopathologic Findings

    PubMed Central

    Lanzman, Rotem S.; Robson, Phil M.; Sun, Maryellen R.; Patel, Amish D.; Mentore, Kimiknu; Wagner, Andrew A.; Genega, Elizabeth M.; Rofsky, Neil M.; Alsop, David C.

    2012-01-01

    Purpose: To assess the value of arterial spin-labeling (ASL) perfusion magnetic resonance (MR) imaging in the characterization of solid renal masses by using histopathologic findings as the standard of reference. Materials and Methods: This prospective study was compliant with HIPAA and approved by the institutional review board. Informed consent was obtained from all patients before imaging. Forty-two consecutive patients suspected of having renal masses underwent ASL MR imaging before their routine 1.5-T clinical MR examination. Mean and peak tumor perfusion levels were obtained by one radiologist, who was blinded to the final histologic diagnosis, by using region of interest analysis. Perfusion values were correlated with histopathologic findings by using analysis of variance. A linear correlation model was used to evaluate the relationship between tumor size and perfusion in clear cell renal cell carcinoma (RCC). P < .05 was considered indicative of a statistically significant difference. Results: Histopathologic findings were available in 34 patients (28 men, six women; mean age ± standard deviation, 60.4 years ± 11.7). The mean perfusion of papillary RCC (27.0 mL/min/100 g ± 15.1) was lower than that of clear cell RCC (171.6 mL/min/100 g ± 61.2, P = .001), chromophobe RCC (152.9 mL/min/100 g ± 80.7, P = .04), unclassified RCC (208.0 mL/min/100 g ± 41.1, P = .001), and oncocytoma (373.9 mL/min/100 g ± 99.2, P < .001). The mean and peak perfusion levels of oncocytoma (373.9 mL/min/100 g ± 99.2 and 512.3 mL/min/100 g ± 146.0, respectively) were higher than those of papillary RCC (27.0 mL/min/100 g ± 15.1 and 78.2 mL/min/100 g ± 39.7, P < .001 for both), chromophobe RCC (152.9 mL/min/100 g ± 80.7 and 260.9 mL/min/100 g ± 61.9; P < .001 and P = .02, respectively), and unclassified RCC (208.0 mL/min/100 g ± 41.1 and 273.3 mL/min/100 g ± 83.4; P = .01 and P = .03, respectively). The mean tumor perfusion of oncocytoma was higher than that of clear cell

  2. Dynamic and still microcirculatory image analysis for quantitative microcirculation research

    NASA Astrophysics Data System (ADS)

    Ying, Xiaoyou; Xiu, Rui-juan

    1994-05-01

    Based on analyses of various types of digital microcirculatory image (DMCI), we summed up the image features of DMCI, the digitizing demands for digital microcirculatory imaging, and the basic characteristics of the DMCI processing. A dynamic and still imaging separation processing (DSISP) mode was designed for developing a DMCI workstation and the DMCI processing. Original images in this study were clinical microcirculatory images from human finger nail-bed and conjunctiva microvasculature, and intravital microvascular network images from animal tissue or organs. A series of dynamic and still microcirculatory image analysis functions were developed in this study. The experimental results indicate most of the established analog video image analysis methods for microcirculatory measurement could be realized in a more flexible way based on the DMCI. More information can be rapidly extracted from the quality improved DMCI by employing intelligence digital image analysis methods. The DSISP mode is very suitable for building a DMCI workstation.

  3. Renal clear cell carcinoma: diffusion tensor imaging diagnostic accuracy and correlations with clinical and histopathological factors.

    PubMed

    Feng, Q; Fang, W; Sun, X P; Sun, S H; Zhang, R M; Ma, Z J

    2017-07-01

    To investigate whether diffusion tensor imaging (DTI) can be used to assess renal clinical histopathology, including the nuclear grade (NG), cell density (CD), and the presence of ki-67. Thirty patients were enrolled in the study and were confirmed at surgical histopathology to have clear cell renal cell carcinoma (CCRCC). For DTI, a coronal echo-planar imaging sequence was performed (1400 ms repetition time, 76 ms echo time, diffusion direction=6, number of excitations=4; b=0 and 800 s/mm(2), 6 mm section thickness with no intersection gap). CD and the presence of ki-67 were compared between the different NGs. Correlations between apparent diffusion coefficients (ADCs), E1, fractional anisotropy (FA), CD, and ki-67 were evaluated. ADC, E1, and FA values are important tools used to identify NG. The cut-off values were 1.003×10(-3) mm(2)/s, 1.277×10(-3) mm(2)/s, and 0.218 mm(2)/s, respectively. The difference between high- and low-grade CD was significant (t=-4.50, p<0.05). Similarly, a significant difference between high and low grade was also found in ki-67 (t=-4.03, p<0.05). ADC, E1, and FA values were decreased with increased CD; a significant negative correlation was found (r=-0.796, -0.865, and -0.996, respectively). Significant negative correlations between ADC, E1, and FA values, and ki-67 were found (r=-0.739, -0.826, and -0.876, respectively). DTI can be used to non-invasively assess CCRCC. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  4. In situ assessment of the renal microcirculation in mechanically ventilated rats using sidestream dark-field imaging.

    PubMed

    Astapenko, D; Jor, O; Lehmann, C; Cerny, V

    2015-02-01

    For microcirculation research there is a need for baseline data and feasibility protocols describing microcirculation of various organs. The aim of our study was to examine the reliability and reproducibility of sidestream dark-field (SDF) imaging within the renal cortical microcirculation in rats. Renal microcirculation was observed using SDF probe placed on the exposed renal surface via the upper midline laparotomy. Video sequences recorded intermittently in short apneic pauses were analyzed off-line by using AVA 3.0 software (MicroVision Medical, Amsterdam, the Netherlands). Results are expressed as mean (SD) or median (25-75% percentiles). We obtained 60 clear sequences from all recorded analyzable videos from all the animals. The total small vessel and all vessel density (in mm.mm(-2) ) were (28.79 ± 0.40) and (28.95 ± 0.40), respectively. The perfused small and all vessel density were (28.79 ± 0.40) and (28.95 ± 0.40), respectively. The DeBacker Score was (19.14 ± 0.43), the proportion of perfused vessels was 100% (100-100%) and the microvascular flow index was 3.49 (3-3.75). We conclude SDF imaging provides a reliable method to examine the renal microvascular bed in vivo and thus can be used for the study of the renal cortical vascular network in various experimental diseases models and clinical settings.

  5. Detection and localization of proteinuria by dynamic contrast-enhanced magnetic resonance imaging using MS325.

    PubMed

    Zhang, Yantian; Choyke, Peter L; Lu, Huiyan; Takahashi, Hideko; Mannon, Roslyn B; Zhang, Xiaojie; Marcos, Hani; Li, King C P; Kopp, Jeffrey B

    2005-06-01

    After renal transplantation, persistent glomerular disease affecting the native kidneys typically causes albuminuria, at least for a period of time, making it difficult to determine in a noninvasive fashion whether proteinuria originates in the native kidneys or the renal allograft. To address this problem, dynamic contrast-enhanced magnetic resonance imaging (MRI) using gadolinium (Gd)-based albumin-bound blood pool contrast agent (MS325) to localize proteinuria was investigated. Glomerular proteinuria was induced in Sprague-Dawley rats by intravenous injection of puromycin aminonucleoside (PAN), whereas control rats received physiologic saline vehicle. Both groups of animals underwent a 40-min dynamic contrast-enhanced MRI using radio frequency spoiled gradient echo imaging sequence after injection of Gd-labeled MS325. Contrast uptake and clearance curves for cortex and medulla were determined from acquired MR images. Compared with controls, proteinuric rats exhibited significantly lower elimination rate constants. The use of gadopentetate dimeglumine (Gd-DTPA) as a contrast agent showed smaller and less specific differences between proteinuric and control groups. In rats with one proteinuric kidney (PAN-treated) and one normal kidney (transplanted from a normal rat), MRI using MS325 was able to differentiate between the two kidneys. The results suggest that MRI with an albumin-bound blood pool contrast agent may be a useful noninvasive way to localize proteinuria. If this technique can be successfully applied in human patients, it may allow for the localization of proteinuria after kidney transplant and thereby provide a noninvasive way to detect disease affecting the renal allograft.

  6. QIN: Quantitative Assessment of Dynamic PET Imaging Data in Cancer Imaging

    PubMed Central

    Muzi, Mark; O’Sullivan, Finbarr; Mankoff, David; Doot, Robert; Pierce, Larry; Kurland, Brenda; Linden, Hannah; Kinahan, Paul

    2012-01-01

    Purpose Clinical imaging in PET is often performed using single time point estimates of tracer uptake or static imaging that provides a spatial map of regional tracer concentration. However, dynamic tracer imaging can provide considerably more information about in vivo biology by delineating both the temporal and spatial pattern of tracer uptake. In addition several potential sources of error that occur in static imaging can be mitigated. This review focuses of the application of dynamic PET imaging to measuring regional cancer biologic features and especially in using dynamic PET imaging for quantitative therapeutic response monitoring in cancer clinical trials. Dynamic PET imaging output parameters, particularly transport (flow) and overall metabolic rate, have provided imaging endpoints for clinical trials at single center institutions for years. However dynamic imaging poses many challenges for multi-center clinical trial implementations from cross-center calibration to the inadequacy of a common informatics infrastructure. Underlying principles and methodology of PET dynamic imaging are first reviewed, followed by an examination of current approaches to dynamic PET image analysis with a specific case example of dynamic FLT imaging to illustrate the approach. PMID:22819579

  7. Metastatic Renal Cell Carcinoma Masquerading as Jugular Foramen Paraganglioma: A Role for Novel Magnetic Resonance Imaging.

    PubMed

    Thomas, Andrew J; Wiggins, Richard H; Gurgel, Richard K

    2017-08-01

    To describe a case of metastatic renal cell carcinoma (RCC) masquerading as a jugular foramen paraganglioma (JP). To compare imaging findings between skull base metastatic RCC and histologically proven paraganglioma. A case of unexpected metastatic skull base RCC is reviewed. Computed tomography (CT) and magnetic resonance imaging (MRI) were compared between 3 confirmed cases of JP and our case of metastatic RCC. Diffusion-weighted MRI (DW-MRI) sequences and computed apparent diffusion coefficient (ADC) values were compared between these entities. A 55-year-old man presents with what appears clinically and radiographically to be JP. The tumor was resected, then discovered on postoperative pathology to be metastatic RCC. Imaging was retrospectively compared between 3 histologically confirmed cases of JP and our case of skull base RCC. The RCC metastasis was indistinguishable from JP on CT and traditional MRI but distinct by ADC values calculated from DW-MRI. Metastatic RCC at the skull base may mimic the clinical presentation and radiographic appearance of JP. The MRI finding of flow voids is seen in both paraganglioma and metastatic RCC. Diffusion-weighted MRI is able to distinguish these entities, highlighting its potential utility in distinguishing skull base lesions.

  8. Dynamic infrared imaging for skin cancer screening

    NASA Astrophysics Data System (ADS)

    Godoy, Sebastián E.; Ramirez, David A.; Myers, Stephen A.; von Winckel, Greg; Krishna, Sanchita; Berwick, Marianne; Padilla, R. Steven; Sen, Pradeep; Krishna, Sanjay

    2015-05-01

    Dynamic thermal imaging (DTI) with infrared cameras is a non-invasive technique with the ability to detect the most common types of skin cancer. We discuss and propose a standardized analysis method for DTI of actual patient data, which achieves high levels of sensitivity and specificity by judiciously selecting pixels with the same initial temperature. This process compensates the intrinsic limitations of the cooling unit and is the key enabling tool in the DTI data analysis. We have extensively tested the methodology on human subjects using thermal infrared image sequences from a pilot study conducted jointly with the University of New Mexico Dermatology Clinic in Albuquerque, New Mexico (ClinicalTrials ID number NCT02154451). All individuals were adult subjects who were scheduled for biopsy or adult volunteers with clinically diagnosed benign condition. The sample size was 102 subjects for the present study. Statistically significant results were obtained that allowed us to distinguish between benign and malignant skin conditions. The sensitivity and specificity was 95% (with a 95% confidence interval of [87.8% 100.0%]) and 83% (with a 95% confidence interval of [73.4% 92.5%]), respectively, and with an area under the curve of 95%. Our results lead us to conclude that the DTI approach in conjunction with the judicious selection of pixels has the potential to provide a fast, accurate, non-contact, and non-invasive way to screen for common types of skin cancer. As such, it has the potential to significantly reduce the number of biopsies performed on suspicious lesions.

  9. Dynamic infrared imaging for the detection of malignancy

    NASA Astrophysics Data System (ADS)

    Button, Terry M.; Li, Haifang; Fisher, Paul; Rosenblatt, Ruth; Dulaimy, Khaldoon; Li, Song; O'Hea, Brian; Salvitti, Mathew; Geronimo, Veronica; Geronimo, Christine; Jambawalikar, Sachin; Carvelli, Paola; Weiss, Richard

    2004-07-01

    The potential for malignancy detection using dynamic infrared imaging (DIRI) has been investigated in an animal model of human malignancy. Malignancy was apparent in images formed at the vasomotor and cardiogenic frequencies of tumour bearing mice. The observation of malignancy was removed by the administration of an agent that blocks vasodilation caused by nitric oxide (NO). Image patterns similar to those that characterize malignancy could be mimicked in normal mice using an NO producing agent. Apparently DIRI allows for cancer detection in this model through vasodilation caused by malignancy generated NO. Dynamic infrared detection of vasomotor and cardiogenic surface perfusion was validated in human subjects by a comparison with laser Doppler flowmetry (LDF). Dynamic infrared imaging technology was then applied to breast cancer detection. It is shown that dynamic infrared images formed at the vasomotor and cardiogenic frequencies of the normal and malignant breast have image pattern differences, which may allow for breast cancer detection.

  10. Imaging complex nutrient dynamics in mycelial networks.

    PubMed

    Fricker, M D; Lee, J A; Bebber, D P; Tlalka, M; Hynes, J; Darrah, P R; Watkinson, S C; Boddy, L

    2008-08-01

    Transport networks are vital components of multi-cellular organisms, distributing nutrients and removing waste products. Animal cardiovascular and respiratory systems, and plant vasculature, are branching trees whose architecture is thought to determine universal scaling laws in these organisms. In contrast, the transport systems of many multi-cellular fungi do not fit into this conceptual framework, as they have evolved to explore a patchy environment in search of new resources, rather than ramify through a three-dimensional organism. These fungi grow as a foraging mycelium, formed by the branching and fusion of threadlike hyphae, that gives rise to a complex network. To function efficiently, the mycelial network must both transport nutrients between spatially separated source and sink regions and also maintain its integrity in the face of continuous attack by mycophagous insects or random damage. Here we review the development of novel imaging approaches and software tools that we have used to characterise nutrient transport and network formation in foraging mycelia over a range of spatial scales. On a millimetre scale, we have used a combination of time-lapse confocal imaging and fluorescence recovery after photobleaching to quantify the rate of diffusive transport through the unique vacuole system in individual hyphae. These data then form the basis of a simulation model to predict the impact of such diffusion-based movement on a scale of several millimetres. On a centimetre scale, we have used novel photon-counting scintillation imaging techniques to visualize radiolabel movement in small microcosms. This approach has revealed novel N-transport phenomena, including rapid, preferential N-resource allocation to C-rich sinks, induction of simultaneous bi-directional transport, abrupt switching between different pre-existing transport routes, and a strong pulsatile component to transport in some species. Analysis of the pulsatile transport component using Fourier

  11. Image Alignment for Multiple Camera High Dynamic Range Microscopy

    PubMed Central

    Eastwood, Brian S.; Childs, Elisabeth C.

    2012-01-01

    This paper investigates the problem of image alignment for multiple camera high dynamic range (HDR) imaging. HDR imaging combines information from images taken with different exposure settings. Combining information from multiple cameras requires an alignment process that is robust to the intensity differences in the images. HDR applications that use a limited number of component images require an alignment technique that is robust to large exposure differences. We evaluate the suitability for HDR alignment of three exposure-robust techniques. We conclude that image alignment based on matching feature descriptors extracted from radiant power images from calibrated cameras yields the most accurate and robust solution. We demonstrate the use of this alignment technique in a high dynamic range video microscope that enables live specimen imaging with a greater level of detail than can be captured with a single camera. PMID:22545028

  12. Targeted contrast-enhanced ultrasound imaging of angiogenesis in an orthotopic mouse tumor model of renal carcinoma.

    PubMed

    Wei, Shuping; Fu, Ninghua; Sun, Yu; Yang, Zhijian; Lei, Li; Huang, Pengfei; Yang, Bin

    2014-06-01

    Previous studies have reported that microbubbles bearing targeting ligands to molecular markers of angiogenesis can be successfully detected by ultrasound imaging in various animal models of solid cancer. In the present study, we sought to investigate the activity of microbubbles targeted to vascular endothelial growth factor receptor 2 (VEGFR2) in an orthotopic model of renal cell carcinoma (RCC). Microbubbles conjugated to an anti-VEGFR2 antibody (MBV) were compared with microbubbles conjugated to an isotype control antibody (MBC) or naked microbubbles (MBN). An orthotopic mouse model of human RCC was established by surgically implanting an established tumor within the renal capsule in mice. Tumor growth and blood flow were verified by B-mode and color Doppler ultrasound imaging. VEGFR2 expression within the tumor and renal parenchyma was detected by immunohistochemistry. The duration of contrast enhancement of MBV was much longer than those of MBN and MBC when assessed over 10 min. The baseline-subtracted contrast intensity within the tumor was higher for MBV than for MBC and MBN (p < 0.01). Additionally, the contrast intensity for MBV was significantly higher in the tumor region than in normal parenchyma (p < 0.01). Microbubbles targeting VEGFR2 exhibit suitable properties for imaging angiogenesis in orthotopic models of renal cell carcinoma, with potential applications in life science research and clinical medicine. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  13. Computer-aided detection of renal calculi from noncontrast CT images using TV-flow and MSER features

    SciTech Connect

    Liu, Jianfei; Wang, Shijun; Turkbey, Evrim B.; Yao, Jianhua; Summers, Ronald M.; Linguraru, Marius George

    2015-01-15

    Purpose: Renal calculi are common extracolonic incidental findings on computed tomographic colonography (CTC). This work aims to develop a fully automated computer-aided diagnosis system to accurately detect renal calculi on CTC images. Methods: The authors developed a total variation (TV) flow method to reduce image noise within the kidneys while maintaining the characteristic appearance of renal calculi. Maximally stable extremal region (MSER) features were then calculated to robustly identify calculi candidates. Finally, the authors computed texture and shape features that were imported to support vector machines for calculus classification. The method was validated on a dataset of 192 patients and compared to a baseline approach that detects calculi by thresholding. The authors also compared their method with the detection approaches using anisotropic diffusion and nonsmoothing. Results: At a false positive rate of 8 per patient, the sensitivities of the new method and the baseline thresholding approach were 69% and 35% (p < 1e − 3) on all calculi from 1 to 433 mm{sup 3} in the testing dataset. The sensitivities of the detection methods using anisotropic diffusion and nonsmoothing were 36% and 0%, respectively. The sensitivity of the new method increased to 90% if only larger and more clinically relevant calculi were considered. Conclusions: Experimental results demonstrated that TV-flow and MSER features are efficient means to robustly and accurately detect renal calculi on low-dose, high noise CTC images. Thus, the proposed method can potentially improve diagnosis.

  14. Computer-aided detection of renal calculi from noncontrast CT images using TV-flow and MSER features

    PubMed Central

    Liu, Jianfei; Wang, Shijun; Turkbey, Evrim B.; Linguraru, Marius George; Yao, Jianhua; Summers, Ronald M.

    2015-01-01

    Purpose: Renal calculi are common extracolonic incidental findings on computed tomographic colonography (CTC). This work aims to develop a fully automated computer-aided diagnosis system to accurately detect renal calculi on CTC images. Methods: The authors developed a total variation (TV) flow method to reduce image noise within the kidneys while maintaining the characteristic appearance of renal calculi. Maximally stable extremal region (MSER) features were then calculated to robustly identify calculi candidates. Finally, the authors computed texture and shape features that were imported to support vector machines for calculus classification. The method was validated on a dataset of 192 patients and compared to a baseline approach that detects calculi by thresholding. The authors also compared their method with the detection approaches using anisotropic diffusion and nonsmoothing. Results: At a false positive rate of 8 per patient, the sensitivities of the new method and the baseline thresholding approach were 69% and 35% (p < 1e − 3) on all calculi from 1 to 433 mm3 in the testing dataset. The sensitivities of the detection methods using anisotropic diffusion and nonsmoothing were 36% and 0%, respectively. The sensitivity of the new method increased to 90% if only larger and more clinically relevant calculi were considered. Conclusions: Experimental results demonstrated that TV-flow and MSER features are efficient means to robustly and accurately detect renal calculi on low-dose, high noise CTC images. Thus, the proposed method can potentially improve diagnosis. PMID:25563255

  15. Computer-aided detection of renal calculi from noncontrast CT images using TV-flow and MSER features.

    PubMed

    Liu, Jianfei; Wang, Shijun; Turkbey, Evrim B; Linguraru, Marius George; Yao, Jianhua; Summers, Ronald M

    2015-01-01

    Renal calculi are common extracolonic incidental findings on computed tomographic colonography (CTC). This work aims to develop a fully automated computer-aided diagnosis system to accurately detect renal calculi on CTC images. The authors developed a total variation (TV) flow method to reduce image noise within the kidneys while maintaining the characteristic appearance of renal calculi. Maximally stable extremal region (MSER) features were then calculated to robustly identify calculi candidates. Finally, the authors computed texture and shape features that were imported to support vector machines for calculus classification. The method was validated on a dataset of 192 patients and compared to a baseline approach that detects calculi by thresholding. The authors also compared their method with the detection approaches using anisotropic diffusion and nonsmoothing. At a false positive rate of 8 per patient, the sensitivities of the new method and the baseline thresholding approach were 69% and 35% (p < 1e - 3) on all calculi from 1 to 433 mm(3) in the testing dataset. The sensitivities of the detection methods using anisotropic diffusion and nonsmoothing were 36% and 0%, respectively. The sensitivity of the new method increased to 90% if only larger and more clinically relevant calculi were considered. Experimental results demonstrated that TV-flow and MSER features are efficient means to robustly and accurately detect renal calculi on low-dose, high noise CTC images. Thus, the proposed method can potentially improve diagnosis.

  16. Real-time extended dynamic range imaging in shearography

    SciTech Connect

    Groves, Roger M.; Pedrini, Giancarlo; Osten, Wolfgang

    2008-10-20

    Extended dynamic range (EDR) imaging is a postprocessing technique commonly associated with photography. Multiple images of a scene are recorded by the camera using different shutter settings and are merged into a single higher dynamic range image. Speckle interferometry and holography techniques require a well-modulated intensity signal to extract the phase information, and of these techniques shearography is most sensitive to different object surface reflectivities as it uses self-referencing from a sheared image. In this paper the authors demonstrate real-time EDR imaging in shearography and present experimental results from a difficult surface reflectivity sample: a wooden panel painting containing gold and dark earth color paint.

  17. Dynamic flat panel detector versus image intensifier in cardiac imaging: dose and image quality

    NASA Astrophysics Data System (ADS)

    Vano, E.; Geiger, B.; Schreiner, A.; Back, C.; Beissel, J.

    2005-12-01

    The practical aspects of the dosimetric and imaging performance of a digital x-ray system for cardiology procedures were evaluated. The system was configured with an image intensifier (II) and later upgraded to a dynamic flat panel detector (FD). Entrance surface air kerma (ESAK) to phantoms of 16, 20, 24 and 28 cm of polymethyl methacrylate (PMMA) and the image quality of a test object were measured. Images were evaluated directly on the monitor and with numerical methods (noise and signal-to-noise ratio). Information contained in the DICOM header for dosimetry audit purposes was also tested. ESAK values per frame (or kerma rate) for the most commonly used cine and fluoroscopy modes for different PMMA thicknesses and for field sizes of 17 and 23 cm for II, and 20 and 25 cm for FD, produced similar results in the evaluated system with both technologies, ranging between 19 and 589 µGy/frame (cine) and 5 and 95 mGy min-1 (fluoroscopy). Image quality for these dose settings was better for the FD version. The 'study dosimetric report' is comprehensive, and its numerical content is sufficiently accurate. There is potential in the future to set those systems with dynamic FD to lower doses than are possible in the current II versions, especially for digital cine runs, or to benefit from improved image quality.

  18. Dynamic flat panel detector versus image intensifier in cardiac imaging: dose and image quality.

    PubMed

    Vano, E; Geiger, B; Schreiner, A; Back, C; Beissel, J

    2005-12-07

    The practical aspects of the dosimetric and imaging performance of a digital x-ray system for cardiology procedures were evaluated. The system was configured with an image intensifier (II) and later upgraded to a dynamic flat panel detector (FD). Entrance surface air kerma (ESAK) to phantoms of 16, 20, 24 and 28 cm of polymethyl methacrylate (PMMA) and the image quality of a test object were measured. Images were evaluated directly on the monitor and with numerical methods (noise and signal-to-noise ratio). Information contained in the DICOM header for dosimetry audit purposes was also tested. ESAK values per frame (or kerma rate) for the most commonly used cine and fluoroscopy modes for different PMMA thicknesses and for field sizes of 17 and 23 cm for II, and 20 and 25 cm for FD, produced similar results in the evaluated system with both technologies, ranging between 19 and 589 microGy/frame (cine) and 5 and 95 mGy min(-1) (fluoroscopy). Image quality for these dose settings was better for the FD version. The 'study dosimetric report' is comprehensive, and its numerical content is sufficiently accurate. There is potential in the future to set those systems with dynamic FD to lower doses than are possible in the current II versions, especially for digital cine runs, or to benefit from improved image quality.

  19. Intratumoral Administration of Holmium-166 Acetylacetonate Microspheres: Antitumor Efficacy and Feasibility of Multimodality Imaging in Renal Cancer

    PubMed Central

    Elschot, Mattijs; Seevinck, Peter R.; Beekman, Freek J.; de Jong, Hugo W. A. M.; Uges, Donald R. A.; Kosterink, Jos G. W.; Luijten, Peter R.; Hennink, Wim E.; van het Schip, Alfred D.; Bosch, J. L. H. Ruud; Nijsen, J. Frank W.

    2013-01-01

    Purpose The increasing incidence of small renal tumors in an aging population with comorbidities has stimulated the development of minimally invasive treatments. This study aimed to assess the efficacy and demonstrate feasibility of multimodality imaging of intratumoral administration of holmium-166 microspheres (166HoAcAcMS). This new technique locally ablates renal tumors through high-energy beta particles, while the gamma rays allow for nuclear imaging and the paramagnetism of holmium allows for MRI. Methods 166HoAcAcMS were administered intratumorally in orthotopic renal tumors (Balb/C mice). Post administration CT, SPECT and MRI was performed. At several time points (2 h, 1, 2, 3, 7 and 14 days) after MS administration, tumors were measured and histologically analyzed. Holmium accumulation in organs was measured using inductively coupled plasma mass spectrometry. Results 166HoAcAcMS were successfully administered to tumor bearing mice. A striking near-complete tumor-control was observed in 166HoAcAcMS treated mice (0.10±0.01 cm3 vs. 4.15±0.3 cm3 for control tumors). Focal necrosis and inflammation was present from 24 h following treatment. Renal parenchyma outside the radiated region showed no histological alterations. Post administration CT, MRI and SPECT imaging revealed clear deposits of 166HoAcAcMS in the kidney. Conclusions Intratumorally administered 166HoAcAcMS has great potential as a new local treatment of renal tumors for surgically unfit patients. In addition to strong cancer control, it provides powerful multimodality imaging opportunities. PMID:23320070

  20. Intratumoral administration of holmium-166 acetylacetonate microspheres: antitumor efficacy and feasibility of multimodality imaging in renal cancer.

    PubMed

    Bult, Wouter; Kroeze, Stephanie G C; Elschot, Mattijs; Seevinck, Peter R; Beekman, Freek J; de Jong, Hugo W A M; Uges, Donald R A; Kosterink, Jos G W; Luijten, Peter R; Hennink, Wim E; van het Schip, Alfred D; Bosch, J L H Ruud; Nijsen, J Frank W; Jans, Judith J M

    2013-01-01

    The increasing incidence of small renal tumors in an aging population with comorbidities has stimulated the development of minimally invasive treatments. This study aimed to assess the efficacy and demonstrate feasibility of multimodality imaging of intratumoral administration of holmium-166 microspheres ((166)HoAcAcMS). This new technique locally ablates renal tumors through high-energy beta particles, while the gamma rays allow for nuclear imaging and the paramagnetism of holmium allows for MRI. (166)HoAcAcMS were administered intratumorally in orthotopic renal tumors (Balb/C mice). Post administration CT, SPECT and MRI was performed. At several time points (2 h, 1, 2, 3, 7 and 14 days) after MS administration, tumors were measured and histologically analyzed. Holmium accumulation in organs was measured using inductively coupled plasma mass spectrometry. (166)HoAcAcMS were successfully administered to tumor bearing mice. A striking near-complete tumor-control was observed in (166)HoAcAcMS treated mice (0.10±0.01 cm(3) vs. 4.15±0.3 cm(3) for control tumors). Focal necrosis and inflammation was present from 24 h following treatment. Renal parenchyma outside the radiated region showed no histological alterations. Post administration CT, MRI and SPECT imaging revealed clear deposits of (166)HoAcAcMS in the kidney. Intratumorally administered (166)HoAcAcMS has great potential as a new local treatment of renal tumors for surgically unfit patients. In addition to strong cancer control, it provides powerful multimodality imaging opportunities.

  1. Label-free fluorescence lifetime and second harmonic generation imaging microscopy improves quantification of experimental renal fibrosis.

    PubMed

    Ranjit, Suman; Dobrinskikh, Evgenia; Montford, John; Dvornikov, Alexander; Lehman, Allison; Orlicky, David J; Nemenoff, Raphael; Gratton, Enrico; Levi, Moshe; Furgeson, Seth

    2016-11-01

    All forms of progressive renal diseases develop a final pathway of tubulointerstitial fibrosis and glomerulosclerosis. Renal fibrosis is usually quantified using histological staining, a process that is time-consuming and pathologist dependent. Here we develop a fast and operator-independent method to measure fibrosis utilizing the murine unilateral ureteral obstruction model which manifests a time-dependent fibrotic increase in obstructed kidneys while the contralateral kidneys are used as controls. After ureteral obstruction, kidneys were analyzed at 7, 14, and 21 days. Fibrosis was quantified using fluorescence lifetime imaging (FLIM) and second harmonic generation (SHG) in a Deep Imaging via Enhanced photon Recovery deep tissue imaging microscope. This microscope was developed for deep tissue along with second and third harmonic generation imaging and has extraordinary sensitivity toward harmonic generation. SHG data suggest the presence of more fibrillar collagen in the obstructed kidneys. The combination of short-wavelength FLIM and SHG analysis results in a robust assessment procedure independent of observer interpretation and let us create criteria to quantify the extent of fibrosis directly from the image. Thus, the FLIM-SHG technique shows remarkable improvement in quantification of renal fibrosis compared to standard histological techniques.

  2. Magnetic Resonance Imaging and Computed Tomography Characteristics of Renal Cell Carcinoma Associated with Xp11.2 Translocation/TFE3 Gene Fusion

    PubMed Central

    Li, Yuan; Wang, Chaofu; Zhou, Liangping; Zhu, Hui; Peng, Weijun

    2014-01-01

    Purpose To characterize Xp11.2 translocation renal cell carcinoma (RCC) using magnetic resonance imaging (MRI) and computed tomography (CT). Methods This study retrospectively collected the MRI and CT data of twelve patients with Xp11.2 translocation RCC confirmed by pathology. Nine cases underwent dynamic contrast-enhanced MRI (DCE-MRI) and 6 cases underwent CT, of which 3 cases underwent MRI and CT simultaneously. The MRI and CT findings were analyzed in regard to tumor position, size, hemorrhagic, cystic or necrotic components, calcification, tumor density, signal intensity and enhancement features. Results The age of the 12 patients ranged from 13 to 46 years (mean age: 23 years). T2WI revealed heterogeneous intensity, hyper-intensity, and slight hypo-intensity in 6 cases, 2 cases, and 1 case, respectively. On DCE-MR images, mild, moderate, and marked rim enhancement of the tumor in the corticomedullary phase (CMP) were observed in 1, 6, and 2 cases, respectively. The tumor parenchyma showed iso-attenuation (n = 4) or slight hyper-attenuation (n = 1) compared to the normal renal cortex on non-contrast CT images. Imaging findings were suggestive of hemorrhage (n = 4) or necrosis (n = 8) in the tumors, and there was evidence of calcification in 8 cases by CT (n = 3) and pathology (n = 8). On dynamic contrast-enhanced CT images, 3 cases and 1 case manifested moderate and strong CMP enhancement, respectively. Nine tumors by MRI and 4 tumors by CT showed prolonged enhancement. Three neoplasms presented at stage I, 2 at stage II, 3 at stage III, and 4 at stage IV according the 2010 AJCC staging criteria. Conclusions XP11.2 translocation RCC should be considered when a child or young adult patient presents with a renal tumor with heterogeneous features such as hemorrhage, necrosis, cystic changes, and calcification on CT and MRI and/or is accompanied by metastatic evidence. PMID:24926688

  3. Advancing Cardiovascular, Neurovascular, and Renal Magnetic Resonance Imaging in Small Rodents Using Cryogenic Radiofrequency Coil Technology

    PubMed Central

    Niendorf, Thoralf; Pohlmann, Andreas; Reimann, Henning M.; Waiczies, Helmar; Peper, Eva; Huelnhagen, Till; Seeliger, Erdmann; Schreiber, Adrian; Kettritz, Ralph; Strobel, Klaus; Ku, Min-Chi; Waiczies, Sonia

    2015-01-01

    Research in pathologies of the brain, heart and kidney have gained immensely from the plethora of studies that have helped shape new methods in magnetic resonance (MR) for characterizing preclinical disease models. Methodical probing into preclinical animal models by MR is invaluable since it allows a careful interpretation and extrapolation of data derived from these models to human disease. In this review we will focus on the applications of cryogenic radiofrequency (RF) coils in small animal MR as a means of boosting image quality (e.g., by supporting MR microscopy) and making data acquisition more efficient (e.g., by reducing measuring time); both being important constituents for thorough investigational studies on animal models of disease. This review attempts to make the (bio)medical imaging, molecular medicine, and pharmaceutical communities aware of this productive ferment and its outstanding significance for anatomical and functional MR in small rodents. The goal is to inspire a more intense interdisciplinary collaboration across the fields to further advance and progress non-invasive MR methods that ultimately support thorough (patho)physiological characterization of animal disease models. In this review, current and potential future applications for the RF coil technology in cardiovascular, neurovascular, and renal disease will be discussed. PMID:26617515

  4. Investigating nephrotoxicity of polymyxin derivatives by mapping renal distribution using mass spectrometry imaging.

    PubMed

    Nilsson, Anna; Goodwin, Richard J A; Swales, John G; Gallagher, Richard; Shankaran, Harish; Sathe, Abhishek; Pradeepan, Selvi; Xue, Aixiang; Keirstead, Natalie; Sasaki, Jennifer C; Andren, Per E; Gupta, Anshul

    2015-09-21

    Colistin and polymyxin B are effective treatment options for Gram-negative resistant bacteria but are used as last-line therapy due to their dose-limiting nephrotoxicity. A critical factor in developing safer polymyxin analogues is understanding accumulation of the drugs and their metabolites, which is currently limited due to the lack of effective techniques for analysis of these challenging molecules. Mass spectrometry imaging (MSI) allows direct detection of targets (drugs, metabolites, and endogenous compounds) from tissue sections. The presented study exemplifies the utility of MSI by measuring the distribution of polymyxin B1, colistin, and polymyxin B nonapeptide (PMBN) within dosed rat kidney tissue sections. The label-free MSI analysis revealed that the nephrotoxic compounds (polymyxin B1 and colistin) preferentially accumulated in the renal cortical region. The less nephrotoxic analogue, polymyxin B nonapeptide, was more uniformly distributed throughout the kidney. In addition, metabolites of the dosed compounds were detected by MSI. Kidney homogenates were analyzed using LC/MS/MS to determine total drug exposure and for metabolite identification. To our knowledge, this is the first time such techniques have been utilized to measure the distribution of polymyxin drugs and their metabolites. By simultaneously detecting the distribution of drug and drug metabolites, MSI offers a powerful alternative to tissue homogenization analysis and label or antibody-based imaging.

  5. Advancing Cardiovascular, Neurovascular, and Renal Magnetic Resonance Imaging in Small Rodents Using Cryogenic Radiofrequency Coil Technology.

    PubMed

    Niendorf, Thoralf; Pohlmann, Andreas; Reimann, Henning M; Waiczies, Helmar; Peper, Eva; Huelnhagen, Till; Seeliger, Erdmann; Schreiber, Adrian; Kettritz, Ralph; Strobel, Klaus; Ku, Min-Chi; Waiczies, Sonia

    2015-01-01

    Research in pathologies of the brain, heart and kidney have gained immensely from the plethora of studies that have helped shape new methods in magnetic resonance (MR) for characterizing preclinical disease models. Methodical probing into preclinical animal models by MR is invaluable since it allows a careful interpretation and extrapolation of data derived from these models to human disease. In this review we will focus on the applications of cryogenic radiofrequency (RF) coils in small animal MR as a means of boosting image quality (e.g., by supporting MR microscopy) and making data acquisition more efficient (e.g., by reducing measuring time); both being important constituents for thorough investigational studies on animal models of disease. This review attempts to make the (bio)medical imaging, molecular medicine, and pharmaceutical communities aware of this productive ferment and its outstanding significance for anatomical and functional MR in small rodents. The goal is to inspire a more intense interdisciplinary collaboration across the fields to further advance and progress non-invasive MR methods that ultimately support thorough (patho)physiological characterization of animal disease models. In this review, current and potential future applications for the RF coil technology in cardiovascular, neurovascular, and renal disease will be discussed.

  6. Determinations of renal cortical and medullary oxygenation using BOLD Magnetic Resonance Imaging and selective diuretics

    PubMed Central

    Warner, Lizette; Glockner, James F.; Woollard, John; Textor, Stephen C.; Romero, Juan C.; Lerman, Lilach O.

    2010-01-01

    Objective This study was undertaken to test the hypothesis that blood O2 level dependent magnetic resonance imaging (BOLD MRI) can detect changes in cortical proximal tubule (PT) and medullary thick ascending limb of Henle (TAL) oxygenation consequent to successive administration of furosemide and acetazolamide (Az). Assessment of PT and TAL function could be useful to monitor renal disease states in vivo. Therefore, the adjunct use of diuretics that inhibit Na+ reabsorption selectively in PT and TAL, Az and furosemide, respectively, may help discern tubular function by using BOLD MRI to detect changes in tissue oxygenation. Material and Methods BOLD MRI signal R2* (inversely related to oxygenation) and tissue oxygenation with intrarenal O2 probes were measured in pigs that received either furosemide (0.5mg/kg) or Az (15mg/kg) alone, Az sequentially after furosemide (n=6 each, 15-minute intervals), or only saline vehicle (n=3). Results R2* decreased in the cortex of Az-treated and medulla of furosemide-treated kidneys, corresponding to an increase in their tissue O2 assessed with probes. However, BOLD MRI also showed decreased cortical R2* following furosemide that was additive to the Az-induced decrease. Az administration, both alone and after furosemide, also decreased renal blood flow (−26±3.5 and −29.2±3%, respectively, p<0.01). Conclusion These results suggest that an increase in medullary and cortical tissue O2 elicited by selective diuretics is detectable by BOLD MRI, but may be complicated by hemodynamic effects of the drugs. Therefore, the BOLD MRI signal may reflect functional changes additional to oxygenation, and needs to be interpreted cautiously. PMID:20856128

  7. Neutron Imaging Reveals Internal Plant Hydraulic Dynamics

    NASA Astrophysics Data System (ADS)

    Warren, J.; Bilheux, H.; Kang, M.; Voisin, S.; Cheng, C.; Horita, J.; Perfect, E.

    2011-12-01

    In situ quantification of soil-plant water fluxes have not been fully successful due to a lack of non-destructive techniques capable of revealing roots or water fluxes at relevant spatial scales. Neutron imaging is a unique non-invasive tool that can assess sub-millimeter scale material properties and transport in situ, and which has been successfully applied to characterize soil and plant water status. Here, we have applied neutron radiography and tomography to quantify water transport through individual maize roots in response to internal plant demand. Zea mays seedlings were grown for 10 days in Flint silica sand within 2.6 cm diameter Al chambers. Using a reactor-based neutron source at Oak Ridge National Laboratory (HFIR), water fluxes were tracked through the maize soil-root systems by collecting consecutive neutron radiographs over a 12 h period following irrigation with D2O. D has a much lower neutron attenuation than H, thus D2O displacement of existing H2O within the plant vascular system, or influx of D2O into previously dry tissue or soil is readily tracked by changes in image intensity through time. Plant water release and uptake was regulated by periodically cycling on a high-intensity grow light. From each maize replicate, selected regions of interest (ROI) were delineated around individual roots, root free soil, stem and leaf segments. Changes in ROI were tracked through time to reveal patterns of water flux. The hydration of root and stem tissue cycled in response to illumination; root water content often increased during darkness, then decreased with illumination as water was transported from the root into the stem. Relative root-shoot hydration through time illustrates the balance between demand, storage capacity and uptake, which varies depending on root characteristics and its localized soil environment. The dynamic transport of water between soil, individual roots, stems and leaves was readily visualized and quantified illustrating the value

  8. Recent advances in intravital imaging of dynamic biological systems.

    PubMed

    Kikuta, Junichi; Ishii, Masaru

    2012-01-01

    Intravital multiphoton microscopy has opened a new era in the field of biological imaging. Focal excitation of fluorophores by simultaneous attack of multiple (normally "two") photons generates images with high spatial resolution, and use of near-infrared lasers for multiphoton excitation allows penetration of thicker specimens, enabling biologists to visualize living cellular dynamics deep inside tissues and organs without thin sectioning. Moreover, the minimized photo-bleaching and toxicity associated with multiphoton techniques is beneficial for imaging of live specimens for extended observation periods. Here we focus on recent findings using intravital multiphoton imaging of dynamic biological systems such as the immune system and bone homeostasis. The immune system comprises highly dynamic networks, in which many cell types actively travel throughout the body and interact with each other in specific areas. Therefore, real-time intravital imaging represents a powerful tool for understanding the mechanisms underlying this dynamic system.

  9. Renal arteriography

    MedlinePlus

    Renal angiogram; Angiography - kidney; Renal angiography; Renal artery stenosis - arteriography ... an artery by a blood clot Renal artery stenosis Renal cell cancer Angiomyolipomas (noncancerous tumors of the ...

  10. Contribution of magnetic resonance imaging to prenatal differential diagnosis of renal tumors: report of two cases and review of the literature.

    PubMed

    Linam, L E; Yu, X; Calvo-Garcia, M A; Rubio, E I; Crombleholme, T M; Bove, K; Kline-Fath, B M

    2010-01-01

    Enlargement of a kidney on prenatal imaging is usually due to hydronephrosis or cystic renal disease, and much less often results from solid tumors such as mesoblastic nephroma, Wilms' tumor, nephroblastomatosis, renal sarcoma, and angiomyolipoma. All can be diagnosed by ultrasound. Magnetic resonance imaging is useful not only in confirming the presence of a renal mass, but also in the evaluation of the contralateral kidney for subtle abnormalities. We present one case each of Wilms' tumor and mesoblastic nephroma, both detected on antenatal ultrasound and further studied with fetal magnetic resonance imaging. Copyright (c) 2010 S. Karger AG, Basel.

  11. The International Atomic Energy Agency software package for the analysis of scintigraphic renal dynamic studies: a tool for the clinician, teacher, and researcher.

    PubMed

    Zaknun, John J; Rajabi, Hossein; Piepsz, Amy; Roca, Isabel; Dondi, Maurizio

    2011-01-01

    Under the auspices of the International Atomic Energy Agency, a new-generation, platform-independent, and x86-compatible software package was developed for the analysis of scintigraphic renal dynamic imaging studies. It provides nuclear medicine professionals cost-free access to the most recent developments in the field. The software package is a step forward towards harmonization and standardization. Embedded functionalities render it a suitable tool for education, research, and for receiving distant expert's opinions. Another objective of this effort is to allow introducing clinically useful parameters of drainage, including normalized residual activity and outflow efficiency. Furthermore, it provides an effective teaching tool for young professionals who are being introduced to dynamic kidney studies by selected teaching case studies. The software facilitates a better understanding through practically approaching different variables and settings and their effect on the numerical results. An effort was made to introduce instruments of quality assurance at the various levels of the program's execution, including visual inspection and automatic detection and correction of patient's motion, automatic placement of regions of interest around the kidneys, cortical regions, and placement of reproducible background region on both primary dynamic and on postmicturition studies. The user can calculate the differential renal function through 2 independent methods, the integral or the Rutland-Patlak approaches. Standardized digital reports, storage and retrieval of regions of interest, and built-in database operations allow the generation and tracing of full image reports and of numerical outputs. The software package is undergoing quality assurance procedures to verify the accuracy and the interuser reproducibility with the final aim of launching the program for use by professionals and teaching institutions worldwide.

  12. Body-mounted robotic instrument guide for image-guided cryotherapy of renal cancer.

    PubMed

    Hata, Nobuhiko; Song, Sang-Eun; Olubiyi, Olutayo; Arimitsu, Yasumichi; Fujimoto, Kosuke; Kato, Takahisa; Tuncali, Kemal; Tani, Soichiro; Tokuda, Junichi

    2016-02-01

    Image-guided cryotherapy of renal cancer is an emerging alternative to surgical nephrectomy, particularly for those who cannot sustain the physical burden of surgery. It is well known that the outcome of this therapy depends on the accurate placement of the cryotherapy probe. Therefore, a robotic instrument guide may help physicians aim the cryotherapy probe precisely to maximize the efficacy of the treatment and avoid damage to critical surrounding structures. The objective of this paper was to propose a robotic instrument guide for orienting cryotherapy probes in image-guided cryotherapy of renal cancers. The authors propose a body-mounted robotic guide that is expected to be less susceptible to guidance errors caused by the patient's whole body motion. Keeping the device's minimal footprint in mind, the authors developed and validated a body-mounted, robotic instrument guide that can maintain the geometrical relationship between the device and the patient's body, even in the presence of the patient's frequent body motions. The guide can orient the cryotherapy probe with the skin incision point as the remote-center-of-motion. The authors' validation studies included an evaluation of the mechanical accuracy and position repeatability of the robotic instrument guide. The authors also performed a mock MRI-guided cryotherapy procedure with a phantom to compare the advantage of robotically assisted probe replacements over a free-hand approach, by introducing organ motions to investigate their effects on the accurate placement of the cryotherapy probe. Measurements collected for performance analysis included accuracy and time taken for probe placements. Multivariate analysis was performed to assess if either or both organ motion and the robotic guide impacted these measurements. The mechanical accuracy and position repeatability of the probe placement using the robotic instrument guide were 0.3 and 0.1 mm, respectively, at a depth of 80 mm. The phantom test indicated

  13. Body-mounted robotic instrument guide for image-guided cryotherapy of renal cancer

    PubMed Central

    Hata, Nobuhiko; Song, Sang-Eun; Olubiyi, Olutayo; Arimitsu, Yasumichi; Fujimoto, Kosuke; Kato, Takahisa; Tuncali, Kemal; Tani, Soichiro; Tokuda, Junichi

    2016-01-01

    Purpose: Image-guided cryotherapy of renal cancer is an emerging alternative to surgical nephrectomy, particularly for those who cannot sustain the physical burden of surgery. It is well known that the outcome of this therapy depends on the accurate placement of the cryotherapy probe. Therefore, a robotic instrument guide may help physicians aim the cryotherapy probe precisely to maximize the efficacy of the treatment and avoid damage to critical surrounding structures. The objective of this paper was to propose a robotic instrument guide for orienting cryotherapy probes in image-guided cryotherapy of renal cancers. The authors propose a body-mounted robotic guide that is expected to be less susceptible to guidance errors caused by the patient’s whole body motion. Methods: Keeping the device’s minimal footprint in mind, the authors developed and validated a body-mounted, robotic instrument guide that can maintain the geometrical relationship between the device and the patient’s body, even in the presence of the patient’s frequent body motions. The guide can orient the cryotherapy probe with the skin incision point as the remote-center-of-motion. The authors’ validation studies included an evaluation of the mechanical accuracy and position repeatability of the robotic instrument guide. The authors also performed a mock MRI-guided cryotherapy procedure with a phantom to compare the advantage of robotically assisted probe replacements over a free-hand approach, by introducing organ motions to investigate their effects on the accurate placement of the cryotherapy probe. Measurements collected for performance analysis included accuracy and time taken for probe placements. Multivariate analysis was performed to assess if either or both organ motion and the robotic guide impacted these measurements. Results: The mechanical accuracy and position repeatability of the probe placement using the robotic instrument guide were 0.3 and 0.1 mm, respectively, at a depth

  14. [Staging urinary bladder cancer with dynamic MR imaging].

    PubMed

    Tsuda, K; Narumi, Y; Nakamura, H; Nonomura, I; Okuyama, A

    2000-11-01

    This article reviews the magnetic resonance (MR) staging of bladder cancer. The multiplanar and soft-tissue characterization capabilities of MR imaging make it a valuable diagnostic tool to image the urinary bladder. Recent advances of MR imaging such as fast imaging, pelvic phased array coil, and dynamic imaging improve the image quality and diagnostic accuracy for staging bladder cancer. Some patient-related factors are also important for optimal imaging of the urinary bladder, especially motion artifacts from the gastrointestinal tract and the degree of bladder distension. An anticholinergic agent should be used for suppressing the motion artifacts. Optimal bladder filling can be achieved by asking patients to void and drink water 1 hour before examinations. Scanning perpendicular to the bladder wall is necessary for optimal evaluation for staging bladder cancer. Oblique scanning is needed in cases when a tumor is not located on the dome, base, anterior wall, posterior wall, or lateral walls. The early phase image of dynamic imaging is most useful for staging tumors. Better contrast between tumor and bladder wall on dynamic images provides high staging accuracy, especially in differentiation between superficial tumors and tumors with muscle invasion. MR imaging is comparable to computed tomography (CT) in the evaluation of lymph nodes. Although MR imaging currently is not appropriate for screening for bladder cancer and detecting small tumors, it has been proved to be most useful in the staging of bladder cancer.

  15. Preparation and Evaluation of (68)Ga-ECC as a PET Renal Imaging Agent.

    PubMed

    Mirzaei, Alireza; Jalilian, Amir Reza; Aghanejad, Ayuob; Mazidi, Mohammad; Yousefnia, Hassan; Shabani, Gholamali; Ardaneh, Khosro; Geramifar, Parham; Beiki, Davood

    2015-09-01

    Development of a gallium-68-labeled renal tracer can be a good substitute for Tc-99m, a known SPECT tracer. In this study, effort was made to develop (68)Ga-ethylenecysteamine cysteine ((68)Ga-ECC). Ga-ECC was prepared using generator-based (68)GaCl3 and ethylenecysteamine cysteine (ECC) at optimized conditions. Stability of the complex was checked in human serum followed by partition coefficient determination of the tracer. The biodistribution of the tracer in rats was studied using tissue counting and PET/CT imaging up to 120 min. Ga-ECC was prepared at optimized conditions in 15 min at 90 °C (radiochemical purity ≈97 ± 0.88 % ITLC, >99 % HPLC, specific activity: 210 ± 5 GBq/mM). (68)Ga-ECC was a water-soluble complex based on partition coefficient data (log P; -1.378) and was stable in the presence of human serum for 2 h at 37 °C. The biodistribution of the tracer demonstrated high kidney excretion of the tracer in 10-20 min. The SUVmax ratios of the liver to left kidney were 0.38 and 0.39 for 30 and 90 min, respectively, indicating high kidney uptake. Initial biodistribution results showed significant kidney and urinary excretion of the tracer comparable to that of the homologous (99m)Tc compound. The complex could be a possible PET kidney imaging agent with a fast imaging time.

  16. Reliability of Total Renal Volume Computation in Polycystic Kidney Disease From Magnetic Resonance Imaging.

    PubMed

    Turco, Dario; Severi, Stefano; Mignani, Renzo; Aiello, Valeria; Magistroni, Riccardo; Corsi, Cristiana

    2015-11-01

    Total renal volume (TRV) is an important quantitative indicator of the progression of autosomal dominant polycystic kidney disease (ADPKD). The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease proposes a method for TRV computation based on manual tracing and geometric modeling. Alternative approaches for TRV computation are represented by the application of advanced image processing techniques. In this study, we aimed to compare TRV estimates derived from these two different approaches. The nearly automated technique for the analysis of magnetic resonance (MR) images was tested on 30 ADPKD patients. TRV was computed from both axial (KVax) and coronal (KVcor) acquisitions and compared to measurements based on geometric modeling (KVap) by linear regression and Bland-Altman analysis. In addition, to assess reproducibility, intraobserver and interobserver variabilities were computed. Linear regression analysis between KVax and KVcor resulted in an excellent correlation (KVax = 1KVcor - 0.78; r(2) = 0.997). Bland-Altman analysis showed a negligible bias and narrow limits of agreement (bias: -11.7 mL; SD: 54.3 mL). Similar results were obtained by comparison of volumes obtained applying the nearly automated method and the one based on geometric modeling (y = 0.98x + 75.9; r(2) = 0.99; bias: -53.7 mL; SD: 108.1 mL). Importantly, geometric modeling does not provide reliable TRV estimates in huge kidney affected by regional deformation. Intraobserver and interobserver variability resulted in very small percentage error <2%. The results of this study provide the feasibility of using a nearly automated approach for accurate and fast evaluation of TRV also in markedly enlarged ADPKD kidneys including exophytic cysts. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  17. Generation of high-dynamic range image from digital photo

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Potemin, Igor S.; Zhdanov, Dmitry D.; Wang, Xu-yang; Cheng, Han

    2016-10-01

    A number of the modern applications such as medical imaging, remote sensing satellites imaging, virtual prototyping etc use the High Dynamic Range Image (HDRI). Generally to obtain HDRI from ordinary digital image the camera is calibrated. The article proposes the camera calibration method based on the clear sky as the standard light source and takes sky luminance from CIE sky model for the corresponding geographical coordinates and time. The article considers base algorithms for getting real luminance values from ordinary digital image and corresponding programmed implementation of the algorithms. Moreover, examples of HDRI reconstructed from ordinary images illustrate the article.

  18. The incidence and location of prostatic calculi on noncontrast computed tomography images in patients with renal calculi.

    PubMed

    Balasar, Mehmet; Poyraz, Necdet; Göğer, Yunus Emre; Unal, Yunus; Pişkin, Mehmet Mesut

    2015-08-01

    In this study, the incidence and location of prostatic calculi on noncontrast abdominal computed tomography (NCACT) images of patients with and without renal stones were investigated. Between 2006 and 2013, NCACT images were taken of 133 patients treated for renal stones (Group I) and of 100 age-matched control patients with putative urinary stone disease (Group II) in our clinic. The incidence and location of prostatic calculi on these images were determined. The location of prostatic calculus was classified as type A if they were located in the main prostatic ducts, and type B if they were located outside the ducts. Prostatic calculi were present in 44.4% of patients in Group I and 21.0% of patients in Group II. The incidence of prostatic calculi was significantly higher in patients with urinary stones compared with those without (P<0.001). The location of prostatic calculi in Group I included 74.6% type A and 25.4% type B while in Group II the locations were 76.2% type A and 23.8% type B. The incidence of prostatic calculi is more prevalent in patients with renal stones. On NCACT images, prostatic calculi were mostly detected in the main prostatic ducts, which were defined as type A.

  19. Dynamic simulation for distortion image with turbulence atmospheric transmission effects

    NASA Astrophysics Data System (ADS)

    Du, Huijie; Fei, Jindong; Qing, Duzheng; Zhao, Hongming; Yu, Hong; Cheng, Chen

    2013-09-01

    The imaging through atmospheric turbulence is an inevitable problem encountered by infrared imaging sensors working in the turbulence atmospheric environment. Before light-rays enter the window of the imaging sensors, the atmospheric turbulence will randomly interfere with the transmission of the light waves came from the objects, causing the distribution of image intensity values on the focal plane to diffuse, the peak value to decrease, the image to get blurred, and the pixels to deviate, and making image identification very difficult. Owing to the fact of the long processing time and that the atmospheric turbulent flow field is unknown and hard to be described by mathematical models, dynamic simulation for distortion Image with turbulence atmospheric transmission effects is much more difficult and challenging in the world. This paper discusses the dynamic simulation for distortion Image of turbulence atmospheric transmission effect. First of all, with the data and the optical transmission model of the turbulence atmospheric, the ray-tracing method is applied to obtain the propagation path of optical ray which propagates through the high-speed turbulent flow field, and then to calculate the OPD from the reference wave to the reconverted wave front and obtain the point spread function (PSF). Secondly, infrared characteristics models of typical scene were established according to the theory of infrared physics and heat conduction, and then the dynamic infrared image was generated by OpenGL. The last step is to obtain the distortion Image with turbulence atmospheric transmission effects .With the data of atmospheric transmission computation, infrared simulation image of every frame was processed according to the theory of image processing and the real-time image simulation, and then the dynamic distortion simulation images with effects of blurring, jitter and shifting were obtained. Above-mentioned simulation method can provide the theoretical bases for recovering

  20. Phase Preserving Dynamic Range Compression of Aeromagnetic Images

    NASA Astrophysics Data System (ADS)

    Kovesi, Peter

    2014-05-01

    Geoscientific images with a high dynamic range, such as aeromagnetic images, are difficult to present in a manner that facilitates interpretation. The data values may range over 20000 nanoteslas or more but a computer monitor is typically designed to present input data constrained to 8 bit values. Standard photographic high dynamic range tonemapping algorithms may be unsuitable, or inapplicable to such data because they are have been developed on the basis of statistics of natural images, feature types found in natural images, and models of the human visual system. These algorithms may also require image segmentation and/or decomposition of the image into base and detail layers but these operations may have no meaning for geoscientific images. For geological and geophysical data high dynamic range images are often dealt with via histogram equalization. The problem with this approach is that the contrast stretch or compression applied to data values depends on how frequently the data values occur in the image and not on the magnitude of any data features themselves. This can lead to inappropriate distortions in the output. Other approaches include use of the Automatic Gain Control algorithm developed by Rajagopalan, or the tilt derivative. A difficulty with these approaches is that the signal can be over-normalized and perception of the overall variations in the signal can be lost. To overcome these problems a method is presented that compresses the dynamic range of an image while preserving local features. It makes no assumptions about the formation of the image, the feature types it contains, or its range of values. Thus, unlike algorithms designed for photographic images, this algorithm can be applied to a wide range of scientific images. The method is based on extracting local phase and amplitude values across the image using monogenic filters. The dynamic range of the image can then be reduced by applying a range reducing function to the amplitude values, for

  1. Magnetic resonance advection imaging of cerebrovascular pulse dynamics.

    PubMed

    Voss, Henning U; Dyke, Jonathan P; Tabelow, Karsten; Schiff, Nicholas D; Ballon, Douglas J

    2017-04-01

    We analyze the pulsatile signal component of dynamic echo planar imaging data from the brain by modeling the dependence between local temporal and spatial signal variability. The resulting magnetic resonance advection imaging maps depict the location of major arteries. Color direction maps allow for visualization of the direction of blood vessels. The potential significance of magnetic resonance advection imaging maps is demonstrated on a functional magnetic resonance imaging data set of 19 healthy subjects. A comparison with the here introduced pulse coherence maps, in which the echo planar imaging signal is correlated with a cardiac pulse signal, shows that the magnetic resonance advection imaging approach results in a better spatial definition without the need for a pulse reference. In addition, it is shown that magnetic resonance advection imaging velocities can be estimates of pulse wave velocities if certain requirements are met, which are specified. Although for this application magnetic resonance advection imaging velocities are not quantitative estimates of pulse wave velocities, they clearly depict local pulsatile dynamics. Magnetic resonance advection imaging can be applied to existing dynamic echo planar imaging data sets with sufficient spatiotemporal resolution. It is discussed whether magnetic resonance advection imaging might have the potential to evolve into a biomarker for the health of the cerebrovascular system.

  2. Dynamic Image Interpretation for Autonomous Vehicle Navigation

    DTIC Science & Technology

    1989-08-01

    characteristics. The two most common methods of obtaining two images from two distinct views are stereopsis and motion. Stereopsis is when two images...environment. In most applications of stereopsis , it is common to orient the cameras such that their image planes are perpendicular to the ground plane...in stereopsis as a special case of motion correspondence. However, in stereopsis , the knowl- edge of the relative locations of the cameras constrains

  3. High Dynamic Range Processing for Magnetic Resonance Imaging

    PubMed Central

    Sukerkar, Preeti A.; Meade, Thomas J.

    2013-01-01

    Purpose To minimize feature loss in T1- and T2-weighted MRI by merging multiple MR images acquired at different TR and TE to generate an image with increased dynamic range. Materials and Methods High Dynamic Range (HDR) processing techniques from the field of photography were applied to a series of acquired MR images. Specifically, a method to parameterize the algorithm for MRI data was developed and tested. T1- and T2-weighted images of a number of contrast agent phantoms and a live mouse were acquired with varying TR and TE parameters. The images were computationally merged to produce HDR-MR images. All acquisitions were performed on a 7.05 T Bruker PharmaScan with a multi-echo spin echo pulse sequence. Results HDR-MRI delineated bright and dark features that were either saturated or indistinguishable from background in standard T1- and T2-weighted MRI. The increased dynamic range preserved intensity gradation over a larger range of T1 and T2 in phantoms and revealed more anatomical features in vivo. Conclusions We have developed and tested a method to apply HDR processing to MR images. The increased dynamic range of HDR-MR images as compared to standard T1- and T2-weighted images minimizes feature loss caused by magnetization recovery or low SNR. PMID:24250788

  4. Calcium dynamics underlying the myogenic response of the renal afferent arteriole

    PubMed Central

    Edwards, Aurélie

    2013-01-01

    The renal afferent arteriole reacts to an elevation in blood pressure with an increase in muscle tone and a decrease in luminal diameter. This effect, known as the myogenic response, is believed to stabilize glomerular filtration and to protect the glomerulus from systolic blood pressure increases, especially in hypertension. To study the mechanisms underlying the myogenic response, we developed a mathematical model of intracellular Ca2+ signaling in an afferent arteriole smooth muscle cell. The model represents detailed transmembrane ionic transport, intracellular Ca2+ dynamics, the kinetics of myosin light chain phosphorylation, and the mechanical behavior of the cell. It assumes that the myogenic response is initiated by pressure-induced changes in the activity of nonselective cation channels. Our model predicts spontaneous vasomotion at physiological luminal pressures and KCl- and diltiazem-induced diameter changes comparable to experimental findings. The time-periodic oscillations stem from the dynamic exchange of Ca2+ between the cytosol and the sarcoplasmic reticulum, coupled to the stimulation of Ca2+-activated potassium (KCa) and chloride (ClCa) channels, and the modulation of voltage-activated L-type channels; blocking sarco/endoplasmic reticulum Ca2+ pumps, ryanodine receptors (RyR), KCa, ClCa, or L-type channels abolishes these oscillations. Our results indicate that the profile of the myogenic response is also strongly dependent on the conductance of ClCa and L-type channels, as well as the activity of plasmalemmal Ca2+ pumps. Furthermore, inhibition of KCa is not necessary to induce myogenic contraction. Lastly, our model suggests that the kinetic behavior of L-type channels results in myogenic kinetics that are substantially faster during constriction than during dilation, consistent with in vitro observations (Loutzenhiser R, Bidani A, Chilton L. Circ. Res. 90: 1316–1324, 2002). PMID:24173354

  5. Angiomyolipoma with minimal fat: differentiation from clear cell renal cell carcinoma and papillary renal cell carcinoma by texture analysis on CT images.

    PubMed

    Yan, Lifen; Liu, Zaiyi; Wang, Guangyi; Huang, Yanqi; Liu, Yubao; Yu, Yuanxin; Liang, Changhong

    2015-09-01

    To retrospectively evaluate the diagnostic performance of texture analysis (TA) for the discrimination of angiomyolipoma (AML) with minimal fat, clear cell renal cell cancer (ccRCC), and papillary renal cell cancer (pRCC) on computed tomography (CT) images and to determine the scanning phase, which contains the strongest discriminative power. Patients with pathologically proved AMLs (n = 18) lacking visible macroscopic fat at CT and patients with pathologically proved ccRCCs (n = 18) and pRCCs (n = 14) were included. All patients underwent CT scan with three phases (precontrast phase [PCP], corticomedullary phase [CMP], and nephrographic phase [NP]). The selected images were analyzed and classified with TA software (MaZda). Texture classification was performed for 1) minimal fat AML versus ccRCC, 2) minimal fat AML versus pRCC, and 3) ccRCC versus pRCC. The classification results were arbitrarily divided into several levels according to the misclassification rates: excellent (misclassification rates ≤10%), good (10%< misclassification rates ≤20%), moderate (20%< misclassification rates ≤30%), fair (30%< misclassification rates ≤40%), and poor (misclassification rates ≥40%). Excellent classification results (error of 0.00%-9.30%) were obtained with nonlinear discriminant analysis for all the three groups, no matter which phase was used. On comparison of the three scanning phases, we observed a trend toward better lesion classification with PCP for minimal fat AML versus ccRCC, CMP, and NP images for ccRCC versus pRCC and found similar discriminative power for minimal fat AML versus pRCC. TA might be a reliable quantitative method for the discrimination of minimal fat AML, ccRCC, and pRCC. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  6. Evidence of a heterogeneous tissue oxygenation: renal ischemia/reperfusion injury in a large animal model

    NASA Astrophysics Data System (ADS)

    Crane, Nicole J.; Huffman, Scott W.; Alemozaffar, Mehrdad; Gage, Frederick A.; Levin, Ira W.; Elster, Eric A.

    2013-03-01

    Renal ischemia that occurs intraoperatively during procedures requiring clamping of the renal artery (such as renal procurement for transplantation and partial nephrectomy for renal cancer) is known to have a significant impact on the viability of that kidney. To better understand the dynamics of intraoperative renal ischemia and recovery of renal oxygenation during reperfusion, a visible reflectance imaging system (VRIS) was developed to measure renal oxygenation during renal artery clamping in both cooled and warm porcine kidneys. For all kidneys, normothermic and hypothermic, visible reflectance imaging demonstrated a spatially distinct decrease in the relative oxy-hemoglobin concentration (%HbO2) of the superior pole of the kidney compared to the middle or inferior pole. Mean relative oxy-hemoglobin concentrations decrease more significantly during ischemia for normothermic kidneys compared to hypothermic kidneys. VRIS may be broadly applicable to provide an indicator of organ ischemia during open and laparoscopic procedures.

  7. Imaging the molecular dynamics of dissociative electron attachment to water

    SciTech Connect

    Adaniya, Hidihito; Rudek, B.; Osipov, Timur; Haxton, Dan; Weber, Thorsten; Rescigno, Thomas N.; McCurdy, C.W.; Belkacem, Ali

    2009-10-19

    Momentum imaging experiments on dissociative electron attachment to the water molecule are combined with ab initio theoretical calculations of the angular dependence of the quantum mechanical amplitude for electron attachment to provide a detailed picture of the molecular dynamics of dissociation attachment via the two lowest energy Feshbach resonances. The combination of momentum imaging experiments and theory can reveal dissociation dynamics for which the axial recoil approximation breaks down and thus provides a powerful reaction microscope for DEA to polyatomics.

  8. Vesicoureteral Reflux Detected on Post-void Image of (99m)Tc MAG3 Renal Scintigraphy.

    PubMed

    Nizar, Naureen; Ahmed, Akhtar

    2013-05-01

    (99m)Tc MAG3 scintigraphic scan is sensitive at depicting focal parenchymal abnormalities and can be used for the measurement of overall renal function. We experienced a 5-year-old boy presenting with bilateral flank fain, intermittent urinary stream and dysuria. On the post-void delayed image of (99m)Tc MAG3 scintigraphic scan vesicoureteral reflux was detected in left non-functioning kidney, which was missed on voiding cystourethrography.

  9. Comparison of imaging methods for diagnosing enlarged parathyroid glands in chronic renal failure

    SciTech Connect

    Takagi, H.; Tominaga, Y.; Uchida, K.; Yamada, N.; Kano, T.; Kawai, M.; Morimoto, T.

    1985-07-01

    Three noninvasive imaging methods, CT, scintigraphy with /sup 201/TlCl and /sup 99m/TcO4-, and ultrasonography, were performed on 36 patients with chronic renal failure and secondary hyperparathyroidism. The patients subsequently underwent total parathyroidectomy and parathyroid autograft. The detection rates of the three methods for the 143 excised parathyroid glands were compared according to gland weight and location. Computed tomography detected 53.8% of all glands and 77.6% of 76 glands weighing more than 500 mg. Scintigraphy detected 51.0% of all glands and 77.6% of glands heavier than 500 mg. Ultrasonography detected 42.7% of all glands and 65.8% of glands heavier than 500 mg. The detection rate of upper glands was best with CT (53.5 and 87.9%): that of lower glands was best with scintigraphy (62.0 and 78.6%). Although the combination of the three methods diagnosed 66.4% of all glands and 89.5% of glands heavier than 500 mg, CT and scintigraphy, the best two combinations, visualized 64.3 and 88.2%.

  10. "One-Stop Shop": Free-Breathing Dynamic Contrast-Enhanced Magnetic Resonance Imaging of the Kidney Using Iterative Reconstruction and Continuous Golden-Angle Radial Sampling.

    PubMed

    Riffel, Philipp; Zoellner, Frank G; Budjan, Johannes; Grimm, Robert; Block, Tobias K; Schoenberg, Stefan O; Hausmann, Daniel

    2016-11-01

    The purpose of the present study was to evaluate a recently introduced technique for free-breathing dynamic contrast-enhanced renal magnetic resonance imaging (MRI) applying a combination of radial k-space sampling, parallel imaging, and compressed sensing. The technique allows retrospective reconstruction of 2 motion-suppressed sets of images from the same acquisition: one with lower temporal resolution but improved image quality for subjective image analysis, and one with high temporal resolution for quantitative perfusion analysis. In this study, 25 patients underwent a kidney examination, including a prototypical fat-suppressed, golden-angle radial stack-of-stars T1-weighted 3-dimensional spoiled gradient-echo examination (GRASP) performed after contrast agent administration during free breathing. Images were reconstructed at temporal resolutions of 55 spokes per frame (6.2 seconds) and 13 spokes per frame (1.5 seconds). The GRASP images were evaluated by 2 blinded radiologists. First, the reconstructions with low temporal resolution underwent subjective image analysis: the radiologists assessed the best arterial phase and the best renal phase and rated image quality score for each patient on a 5-point Likert-type scale.In addition, the diagnostic confidence was rated according to a 3-point Likert-type scale. Similarly, respiratory motion artifacts and streak artifacts were rated according to a 3-point Likert-type scale.Then, the reconstructions with high temporal resolution were analyzed with a voxel-by-voxel deconvolution approach to determine the renal plasma flow, and the results were compared with values reported in previous literature. Reader 1 and reader 2 rated the overall image quality score for the best arterial phase and the best renal phase with a median image quality score of 4 (good image quality) for both phases, respectively. A high diagnostic confidence (median score of 3) was observed. There were no respiratory motion artifacts in any of the

  11. Remote histology learning from static versus dynamic microscopic images.

    PubMed

    Mione, Sylvia; Valcke, Martin; Cornelissen, Maria

    2016-05-06

    Histology is the study of microscopic structures in normal tissue sections. Curriculum redesign in medicine has led to a decrease in the use of optical microscopes during practical classes. Other imaging solutions have been implemented to facilitate remote learning. With advancements in imaging technologies, learning material can now be digitized. Digitized microscopy images can be presented in either a static or dynamic format. This study of remote histology education identifies whether dynamic pictures are superior to static images for the acquisition of histological knowledge. Test results of two cohorts of second-year Bachelor in Medicine students at Ghent University were analyzed in two consecutive academic years: Cohort 1 (n = 190) and Cohort 2 (n = 174). Students in Cohort 1 worked with static images whereas students in Cohort 2 were presented with dynamic images. ANCOVA was applied to study differences in microscopy performance scores between the two cohorts, taking into account any possible initial differences in prior knowledge. The results show that practical histology scores are significantly higher with dynamic images as compared to static images (F (1,361) = 15.14, P < 0.01), regardless of student's gender and performance level. Several reasons for this finding can be explained in accordance with cognitivist learning theory. Since the findings suggest that knowledge construction with dynamic pictures is stronger as compared to static images, dynamic images should be introduced in a remote setting for microscopy education. Further implementation within a larger electronic learning management system needs to be explored in future research. Anat Sci Educ 9: 222-230. © 2015 American Association of Anatomists. © 2015 American Association of Anatomists.

  12. Optical imaging of fast, dynamic neurophysiological function.

    SciTech Connect

    Rector, D. M.; Carter, K. M.; Yao, X.; George, J. S.

    2002-01-01

    Fast evoked responses were imaged from rat dorsal medulla and whisker barrel cortex. To investigate the biophysical mechanisms involved, fast optical responses associated with isolated crustacean nerve stimulation were recorded using birefringence and scattered light. Such studies allow optimization of non-invasive imaging techniques being developed for use in humans.

  13. Comparison of iodine-131 OIH and technetium-99m MAG3 renal imaging in volunteers

    SciTech Connect

    Taylor, A. Jr.; Eshima, D.; Fritzberg, A.R.; Christian, P.E.; Kasina, S.

    1986-06-01

    Animal studies have suggested that the nonisomeric N3S triamide mercaptide ligand, /sup 99m/Tc mercaptoacetyltriglycine (MAG3), may provide a satisfactory /sup 99m/Tc-labeled replacement for /sup 131/I hippurate (OIH). Sequential 30-min (/sup 99m/Tc)MAG3 (5-10 mCi) and (/sup 131/I)OIH (300 microCi) imaging studies were performed in ten normal volunteers in order to compare the image quality, renal excretion, blood clearance, and time to peak height of the renogram curve. In addition, (/sup 99m/Tc) MAG3 (5 mCi) and (/sup 131/I)OIH (150 microCi) were administered simultaneously in eight volunteers for comparison of 180-min blood and plasma clearances and urine excretion. In the sequential imaging studies, the blood clearance of (/sup 99m/Tc)MAG3 was more rapid than (/sup 131/I)OIH with a mean clearance of 1.30 l/min compared with 0.88 l/min for (/sup 131/I)OIH (p less than 0.05). Seventy-three percent of the injected dose of the MAG3 was excreted by 30 min compared with 66.8% for (/sup 131/I)OIH. Whole kidney and cortical renogram curves showed no significant difference in the time to peak height for MAG3 and (/sup 131/I)OIH. In all subjects, the quality of the (/sup 99m/Tc)MAG3 images were clearly superior to (/sup 131/I)OIH. Following simultaneous injection, blood and plasma clearances for (/sup 131/I)OIH were more rapid than MAG3 when determined for multiple time intervals from 0-30 to 0-180 min (p less than or equal to 0.05). The 0-30-min clearances of MAG3 and (/sup 131/I)OIH were only slightly greater than the 0-180-min clearances and can be used to obtain valid comparisons of the two agents. As in the sequential study, 30-min urine excretion was greater for MAG3 than (/sup 131/I)OIH (73.1 compared with 69.6%) but the difference was not statistically significant.

  14. Renal Cell Carcinoma with Paraneoplastic Manifestations: Imaging with CT and F-18 FDG PET/CT.

    PubMed

    Nguyen, Ba D; Roarke, Michael C

    2007-01-01

    We present a case of renal cell carcinoma with prominent inflammatory and paraneoplastic manifestations. The initial CT detection of renal malignancy and subsequent post-therapeutic F-18 FDG PET/CT diagnosis of occult osseous metastasis were based on the patient's anemia, thrombocytosis and abnormally increased levels of serum C-reactive protein.

  15. Dynamic changes of early-stage aortic lipid deposition in chronic renal failure rats and effects of decorin gene therapy

    PubMed Central

    MA, HONG-BO; WANG, RONG; YU, KE-ZHOU; YU, CHE

    2015-01-01

    The aim of the present study was to clarify the association between lipid metabolism and the atherosclerosis in early-stage chronic renal failure at the molecular level and to explore the efficacy of decorin on chronic renal failure. Sprague Dawley rats receiving 5/6 nephrectomy and Sham surgery were divided into control and experimental groups. Sprague Dawley rats receiving 5/6 nephrectomy were divided into control and experimental groups, and the experimental group was further subdivided into rats receiving treatment with fibroblasts (FBs) transfected either with empty vector and with a decorin (DCN) gene. The dynamic levels of triglyceride (TG), total cholesterol (T-Ch) and total phospholipid (T-PL) were detected on the 10th, 30th and 60th days. The body weight, blood lipid levels, renal function and renal tissue were observed after four weeks, and transforming growth factor-βl and protein expression was detected by immunohistochemistry. In total, 4 weeks after treatment, the DCN expression in the renal tissue of rats treated with DCN-transfected FBs was significantly increased compared to that in the control rats. The results showed that the levels of the three lipids in the aortic arches were slightly elevated on the 10th day compared with those in the control group, and the TG level was significantly increased on the 30th day. The levels of T-Ch, TG and T-PL in the aortic arches were significantly elevated on the 60th day. The TG and T-Ch levels in the plasma and aortic tissues of Sprague Dawley rats receiving 5/6 nephrectomy without any treatment and after receiving treatment with FBs transfected with empty vector were significantly increased compared with those in the control group. The increased T-Ch and decreased T-PL levels in the erythrocyte membrane increased the rigidity of the erythrocyte and decreased erythrocyte deformability. In conclusion, highly expressed DCN mitigated renal fibrosis and thus delayed renal failure as well as mitigating the

  16. Design of a dynamic dual-foveated imaging system.

    PubMed

    Du, Xiaoyu; Chang, Jun; Zhang, Yunqiang; Wang, Xi; Zhang, Bochuan; Gao, Lei; Xiao, Liping

    2015-10-05

    A new kind of dynamic dual-foveated imaging system in the infrared band is designed and optimized in this paper. Dual-foveated imaging refers to the variation in spatial resolution at the two selected fields across the image. Such variable resolution imaging system is suitable for a variety of applications including monitoring, recognition, and remote operation of unmanned aerial vehicle. In this system, a transmissive spatial light modulator (SLM) is used as an active optical element which is located near the image plane instead of pupil plane creatively in order to divide the two selected fields.

  17. An improvement to the diffraction-enhanced imaging method that permits imaging of dynamic systems

    NASA Astrophysics Data System (ADS)

    Siu, K. K. W.; Kitchen, M. J.; Pavlov, K. M.; Gillam, J. E.; Lewis, R. A.; Uesugi, K.; Yagi, N.

    2005-08-01

    We present an improvement to the diffraction-enhanced imaging (DEI) method that permits imaging of moving samples or other dynamic systems in real time. The method relies on the use of a thin Bragg analyzer crystal and simultaneous acquisition of the multiple images necessary for the DEI reconstruction of the apparent absorption and refraction images. These images are conventionally acquired at multiple points on the reflectivity curve of an analyzer crystal which presents technical challenges and precludes imaging of moving subjects. We have demonstrated the potential of the technique by taking DEI "movies" of an artificially moving mouse leg joint, acquired at the Biomedical Imaging Centre at SPring-8, Japan.

  18. Dynamic Ultrasound Imaging Applications to Quantify Musculoskeletal Function

    PubMed Central

    Sikdar, Siddhartha; Wei, Qi; Cortes, Nelson

    2014-01-01

    Advances in imaging methods have led to new capability to study muscle and tendon motion in vivo. Direct measurements of muscle and tendon kinematics using imaging may lead to improved understanding of musculoskeletal function. This review presents quantitative ultrasound methods for muscle dynamics that can be used to assess in vivo musculoskeletal function when integrated with other conventional biomechanical measurements. PMID:24949846

  19. Dynamic ultrasound imaging applications to quantify musculoskeletal function.

    PubMed

    Sikdar, Siddhartha; Wei, Qi; Cortes, Nelson

    2014-07-01

    Advances in imaging methods have led to new capability to study muscle and tendon motion in vivo. Direct measurements of muscle and tendon kinematics using imaging may lead to improved understanding of musculoskeletal function. This review presents quantitative ultrasound methods for muscle dynamics that can be used to assess in vivo musculoskeletal function when integrated with other conventional biomechanical measurements.

  20. Dynamic Imaging of a Pigmented Free-Floating Vitreous Cyst.

    PubMed

    Grewal, Dilraj S; Fekrat, Sharon

    2016-10-01

    The authors present an incidentally noted pigmented anterior vitreous cyst in an asymptomatic male adult. Observation was elected. Stability during the course of 2 years and mobility of the vitreous cyst using dynamic imaging are demonstrated. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:975-977.].

  1. Analysis of dynamic brain imaging data.

    PubMed Central

    Mitra, P P; Pesaran, B

    1999-01-01

    Modern imaging techniques for probing brain function, including functional magnetic resonance imaging, intrinsic and extrinsic contrast optical imaging, and magnetoencephalography, generate large data sets with complex content. In this paper we develop appropriate techniques for analysis and visualization of such imaging data to separate the signal from the noise and characterize the signal. The techniques developed fall into the general category of multivariate time series analysis, and in particular we extensively use the multitaper framework of spectral analysis. We develop specific protocols for the analysis of fMRI, optical imaging, and MEG data, and illustrate the techniques by applications to real data sets generated by these imaging modalities. In general, the analysis protocols involve two distinct stages: "noise" characterization and suppression, and "signal" characterization and visualization. An important general conclusion of our study is the utility of a frequency-based representation, with short, moving analysis windows to account for nonstationarity in the data. Of particular note are 1) the development of a decomposition technique (space-frequency singular value decomposition) that is shown to be a useful means of characterizing the image data, and 2) the development of an algorithm, based on multitaper methods, for the removal of approximately periodic physiological artifacts arising from cardiac and respiratory sources. PMID:9929474

  2. Image-Guided Embolization Coil Placement for Identification of an Endophytic, Isoechoic Renal Mass During Robotic Partial Nephrectomy

    PubMed Central

    Forauer, Andrew; Seigne, John D.; Hyams, Elias S.

    2015-01-01

    Abstract Background: Intraoperative ultrasonography has proven to be a useful tool for tumor identification during robot-assisted laparoscopic partial nephrectomy (RALPN). However, its utility is limited in renal tumors that are completely endophytic and isoechoic in nature. We present a novel approach to intraoperative tumor identification using preoperative percutaneous intratumoral embolization coil placement that may be utilized in the management of such cases. Case Presentation: A 42-year-old Caucasian male was referred with an incidentally discovered right renal mass that was posterior and completely endophytic. He desired a RALPN; however, preoperative renal ultrasound demonstrated an isoechoic lesion. Thus, the patient underwent preoperative image-guided placement of an embolization coil within the tumor. This facilitated identification of the tumor intraoperatively using intracorporeal ultrasound centered on the coil and enabled resection with negative margins. Conclusion: Utilizing a novel approach analogous to preoperative localization of other solid malignancies, such as breast cancer, we were able to effectively identify and resect an isoechoic renal mass during RALPN. PMID:27579392

  3. Imaging plants dynamics in heterogenic environments.

    PubMed

    Fiorani, Fabio; Rascher, Uwe; Jahnke, Siegfried; Schurr, Ulrich

    2012-04-01

    Noninvasive imaging sensors and computer vision approaches are key technologies to quantify plant structure, physiological status, and performance. Today, imaging sensors exploit a wide range of the electromagnetic spectrum, and they can be deployed to measure a growing number of traits, also in heterogenic environments. Recent advances include the possibility to acquire high-resolution spectra by imaging spectroscopy and classify signatures that might be informative of plant development, nutrition, health, and disease. Three-dimensional (3D) reconstruction of surfaces and volume is of particular interest, enabling functional and mechanistic analyses. While taking pictures is relatively easy, quantitative interpretation often remains challenging and requires integrating knowledge of sensor physics, image analysis, and complex traits characterizing plant phenotypes.

  4. Imaging of vascular dynamics within the foot using dynamic diffuse optical tomography to diagnose peripheral arterial disease

    NASA Astrophysics Data System (ADS)

    Khalil, M. A.; Kim, H. K.; Hoi, J. W.; Kim, I.; Dayal, R.; Shrikande, G.; Hielscher, A. H.

    2013-03-01

    Peripheral Arterial Disease (PAD) is the narrowing of the functional area of the artery generally due to atherosclerosis. It affects between 8-12 million people in the United States and if untreated this can lead to ulceration, gangrene and ultimately amputation. The current diagnostic method for PAD is the ankle-brachial index (ABI). The ABI is a ratio of the patient's systolic blood pressure in the foot to that of the brachial artery in the arm, a ratio below 0.9 is indicative of affected vasculature. However, this method is ineffective in patients with calcified arteries (diabetic and end-stage renal failure patients), which falsely elevates the ABI recording resulting in a false negative reading. In this paper we present our results in a pilot study to deduce optical tomography's ability to detect poor blood perfusion in the foot. We performed an IRB approved 30 patient study, where we imaged the feet of the enrolled patients during a five stage dynamic imaging sequence. The patients were split up into three groups: 10 healthy subjects, 10 PAD patients and 10 PAD patients with diabetes and they were imaged while applying a pressure cuff to their thigh. Differences in the magnitude of blood pooling in the foot and rate at which the blood pools in the foot are all indicative of arterial disease.

  5. Color transfer between high-dynamic-range images

    NASA Astrophysics Data System (ADS)

    Hristova, Hristina; Cozot, Rémi; Le Meur, Olivier; Bouatouch, Kadi

    2015-09-01

    Color transfer methods alter the look of a source image with regards to a reference image. So far, the proposed color transfer methods have been limited to low-dynamic-range (LDR) images. Unlike LDR images, which are display-dependent, high-dynamic-range (HDR) images contain real physical values of the world luminance and are able to capture high luminance variations and finest details of real world scenes. Therefore, there exists a strong discrepancy between the two types of images. In this paper, we bridge the gap between the color transfer domain and the HDR imagery by introducing HDR extensions to LDR color transfer methods. We tackle the main issues of applying a color transfer between two HDR images. First, to address the nature of light and color distributions in the context of HDR imagery, we carry out modifications of traditional color spaces. Furthermore, we ensure high precision in the quantization of the dynamic range for histogram computations. As image clustering (based on light and colors) proved to be an important aspect of color transfer, we analyze it and adapt it to the HDR domain. Our framework has been applied to several state-of-the-art color transfer methods. Qualitative experiments have shown that results obtained with the proposed adaptation approach exhibit less artifacts and are visually more pleasing than results obtained when straightforwardly applying existing color transfer methods to HDR images.

  6. Accelerated dynamic EPR imaging using fast acquisition and compressive recovery

    NASA Astrophysics Data System (ADS)

    Ahmad, Rizwan; Samouilov, Alexandre; Zweier, Jay L.

    2016-12-01

    Electron paramagnetic resonance (EPR) allows quantitative imaging of tissue redox status, which provides important information about ischemic syndromes, cancer and other pathologies. For continuous wave EPR imaging, however, poor signal-to-noise ratio and low acquisition efficiency limit its ability to image dynamic processes in vivo including tissue redox, where conditions can change rapidly. Here, we present a data acquisition and processing framework that couples fast acquisition with compressive sensing-inspired image recovery to enable EPR-based redox imaging with high spatial and temporal resolutions. The fast acquisition (FA) allows collecting more, albeit noisier, projections in a given scan time. The composite regularization based processing method, called spatio-temporal adaptive recovery (STAR), not only exploits sparsity in multiple representations of the spatio-temporal image but also adaptively adjusts the regularization strength for each representation based on its inherent level of the sparsity. As a result, STAR adjusts to the disparity in the level of sparsity across multiple representations, without introducing any tuning parameter. Our simulation and phantom imaging studies indicate that a combination of fast acquisition and STAR (FASTAR) enables high-fidelity recovery of volumetric image series, with each volumetric image employing less than 10 s of scan. In addition to image fidelity, the time constants derived from FASTAR also match closely to the ground truth even when a small number of projections are used for recovery. This development will enhance the capability of EPR to study fast dynamic processes that cannot be investigated using existing EPR imaging techniques.

  7. Accelerated dynamic EPR imaging using fast acquisition and compressive recovery.

    PubMed

    Ahmad, Rizwan; Samouilov, Alexandre; Zweier, Jay L

    2016-12-01

    Electron paramagnetic resonance (EPR) allows quantitative imaging of tissue redox status, which provides important information about ischemic syndromes, cancer and other pathologies. For continuous wave EPR imaging, however, poor signal-to-noise ratio and low acquisition efficiency limit its ability to image dynamic processes in vivo including tissue redox, where conditions can change rapidly. Here, we present a data acquisition and processing framework that couples fast acquisition with compressive sensing-inspired image recovery to enable EPR-based redox imaging with high spatial and temporal resolutions. The fast acquisition (FA) allows collecting more, albeit noisier, projections in a given scan time. The composite regularization based processing method, called spatio-temporal adaptive recovery (STAR), not only exploits sparsity in multiple representations of the spatio-temporal image but also adaptively adjusts the regularization strength for each representation based on its inherent level of the sparsity. As a result, STAR adjusts to the disparity in the level of sparsity across multiple representations, without introducing any tuning parameter. Our simulation and phantom imaging studies indicate that a combination of fast acquisition and STAR (FASTAR) enables high-fidelity recovery of volumetric image series, with each volumetric image employing less than 10 s of scan. In addition to image fidelity, the time constants derived from FASTAR also match closely to the ground truth even when a small number of projections are used for recovery. This development will enhance the capability of EPR to study fast dynamic processes that cannot be investigated using existing EPR imaging techniques.

  8. Stereo Vision-Based High Dynamic Range Imaging Using Differently-Exposed Image Pair.

    PubMed

    Park, Won-Jae; Ji, Seo-Won; Kang, Seok-Jae; Jung, Seung-Won; Ko, Sung-Jea

    2017-06-22

    In this paper, a high dynamic range (HDR) imaging method based on the stereo vision system is presented. The proposed method uses differently exposed low dynamic range (LDR) images captured from a stereo camera. The stereo LDR images are first converted to initial stereo HDR images using the inverse camera response function estimated from the LDR images. However, due to the limited dynamic range of the stereo LDR camera, the radiance values in under/over-exposed regions of the initial main-view (MV) HDR image can be lost. To restore these radiance values, the proposed stereo matching and hole-filling algorithms are applied to the stereo HDR images. Specifically, the auxiliary-view (AV) HDR image is warped by using the estimated disparity between initial the stereo HDR images and then effective hole-filling is applied to the warped AV HDR image. To reconstruct the final MV HDR, the warped and hole-filled AV HDR image is fused with the initial MV HDR image using the weight map. The experimental results demonstrate objectively and subjectively that the proposed stereo HDR imaging method provides better performance compared to the conventional method.

  9. Stereo Vision-Based High Dynamic Range Imaging Using Differently-Exposed Image Pair

    PubMed Central

    Park, Won-Jae; Ji, Seo-Won; Kang, Seok-Jae; Jung, Seung-Won; Ko, Sung-Jea

    2017-01-01

    In this paper, a high dynamic range (HDR) imaging method based on the stereo vision system is presented. The proposed method uses differently exposed low dynamic range (LDR) images captured from a stereo camera. The stereo LDR images are first converted to initial stereo HDR images using the inverse camera response function estimated from the LDR images. However, due to the limited dynamic range of the stereo LDR camera, the radiance values in under/over-exposed regions of the initial main-view (MV) HDR image can be lost. To restore these radiance values, the proposed stereo matching and hole-filling algorithms are applied to the stereo HDR images. Specifically, the auxiliary-view (AV) HDR image is warped by using the estimated disparity between initial the stereo HDR images and then effective hole-filling is applied to the warped AV HDR image. To reconstruct the final MV HDR, the warped and hole-filled AV HDR image is fused with the initial MV HDR image using the weight map. The experimental results demonstrate objectively and subjectively that the proposed stereo HDR imaging method provides better performance compared to the conventional method. PMID:28640235

  10. Dynamic Granularity for X-Ray Imaging Systems

    NASA Astrophysics Data System (ADS)

    Geissel, Matthias; Bigman, Verle H.; Edens, Aaron D.; Schollmeier, Marius; Smith, Ian C.; Shores, Jonathon E.; Porter, John L.

    2013-10-01

    Dynamic range and spatial resolution are correlated, because imaging units such as pixels or film grains can cover a wider dynamic range if they are larger, so that they can contain more electrons in a well or fluorescence centers in a grain. However, for systems that are subject to low photon flux, statistical noise influences the spatial resolution. Statistical noise is important for many experiments that rely on single shot X-ray imaging diagnostics. Detectors face a limited photon flux and often also a limited detection probability, where photons of higher energy may just penetrate the detector. The effective spatial resolution depends on detector efficiency, incident photon flux, detector cell size (grain/pixel), and the detector's inherent noise. We describe the combined influences with a ``dynamic granularity'' function, based on measurements of the grain size dependent distinguishability of grey levels. The dynamic granularity is unique to each imaging system, but allows us to quantify the performance of different detectors in a system. We have characterized a fast microchannel plate imaging detector and imaging plate with respect to dynamic granularity on the 6.151 keV crystal imaging system at the Z-Beamlet laser. Sandia Natl. Labs is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. Dept. of Energy's Natl. Nucl. Security Administration under contract DE-AC04-94AL8500.

  11. Registration of parametric dynamic F-18-FDG PET/CT breast images with parametric dynamic Gd-DTPA breast images

    NASA Astrophysics Data System (ADS)

    Magri, Alphonso; Krol, Andrzej; Lipson, Edward; Mandel, James; McGraw, Wendy; Lee, Wei; Tillapaugh-Fay, Gwen; Feiglin, David

    2009-02-01

    This study was undertaken to register 3D parametric breast images derived from Gd-DTPA MR and F-18-FDG PET/CT dynamic image series. Nonlinear curve fitting (Levenburg-Marquardt algorithm) based on realistic two-compartment models was performed voxel-by-voxel separately for MR (Brix) and PET (Patlak). PET dynamic series consists of 50 frames of 1-minute duration. Each consecutive PET image was nonrigidly registered to the first frame using a finite element method and fiducial skin markers. The 12 post-contrast MR images were nonrigidly registered to the precontrast frame using a free-form deformation (FFD) method. Parametric MR images were registered to parametric PET images via CT using FFD because the first PET time frame was acquired immediately after the CT image on a PET/CT scanner and is considered registered to the CT image. We conclude that nonrigid registration of PET and MR parametric images using CT data acquired during PET/CT scan and the FFD method resulted in their improved spatial coregistration. The success of this procedure was limited due to relatively large target registration error, TRE = 15.1+/-7.7 mm, as compared to spatial resolution of PET (6-7 mm), and swirling image artifacts created in MR parametric images by the FFD. Further refinement of nonrigid registration of PET and MR parametric images is necessary to enhance visualization and integration of complex diagnostic information provided by both modalities that will lead to improved diagnostic performance.

  12. Acute pyelonephritis resulting in intense vascular blush during dynamic renal scintigraphy

    PubMed Central

    Joshi, Prathamesh; Deshpande, Sushil; Kulkarni, Mukta; Shetkar, Shubhangi

    2016-01-01

    A thirty-year-old male underwent Tc-99m diethylenetriaminepentaacetic acid renal scintigraphy for evaluation of gross hydronephrosis of left kidney. The perfusion phase revealed an intense vascular blush in left renal fossa. The uptake phase of scintigraphy revealed the absence of tracer uptake in left kidney. Contrast-enhanced computed tomography (CECT) was performed for evaluating the cause of vascular blush. CECT demonstrated features suggestive of acute pyelonephritis (APN) involving lower pole of the hydronephrotic left kidney, corresponding to the site of vascular blush seen on renal scintigraphy. The postnephrectomy specimen confirmed the diagnosis of APN suggested on CECT. PMID:26917903

  13. Blurred Star Image Processing for Star Sensors under Dynamic Conditions

    PubMed Central

    Zhang, Weina; Quan, Wei; Guo, Lei

    2012-01-01

    The precision of star point location is significant to identify the star map and to acquire the aircraft attitude for star sensors. Under dynamic conditions, star images are not only corrupted by various noises, but also blurred due to the angular rate of the star sensor. According to different angular rates under dynamic conditions, a novel method is proposed in this article, which includes a denoising method based on adaptive wavelet threshold and a restoration method based on the large angular rate. The adaptive threshold is adopted for denoising the star image when the angular rate is in the dynamic range. Then, the mathematical model of motion blur is deduced so as to restore the blurred star map due to large angular rate. Simulation results validate the effectiveness of the proposed method, which is suitable for blurred star image processing and practical for attitude determination of satellites under dynamic conditions. PMID:22778666

  14. Unsupervised analysis of small animal dynamic Cerenkov luminescence imaging

    NASA Astrophysics Data System (ADS)

    Spinelli, Antonello E.; Boschi, Federico

    2011-12-01

    Clustering analysis (CA) and principal component analysis (PCA) were applied to dynamic Cerenkov luminescence images (dCLI). In order to investigate the performances of the proposed approaches, two distinct dynamic data sets obtained by injecting mice with 32P-ATP and 18F-FDG were acquired using the IVIS 200 optical imager. The k-means clustering algorithm has been applied to dCLI and was implemented using interactive data language 8.1. We show that cluster analysis allows us to obtain good agreement between the clustered and the corresponding emission regions like the bladder, the liver, and the tumor. We also show a good correspondence between the time activity curves of the different regions obtained by using CA and manual region of interest analysis on dCLIT and PCA images. We conclude that CA provides an automatic unsupervised method for the analysis of preclinical dynamic Cerenkov luminescence image data.

  15. Unsupervised analysis of small animal dynamic Cerenkov luminescence imaging

    NASA Astrophysics Data System (ADS)

    Spinelli, Antonello E.; Boschi, Federico

    2011-12-01

    Clustering analysis (CA) and principal component analysis (PCA) were applied to dynamic Cerenkov luminescence images (dCLI). In order to investigate the performances of the proposed approaches, two distinct dynamic data sets obtained by injecting mice with 32P-ATP and 18F-FDG were acquired using the IVIS 200 optical imager. The k-means clustering algorithm has been applied to dCLI and was implemented using interactive data language 8.1. We show that cluster analysis allows us to obtain good agreement between the clustered and the corresponding emission regions like the bladder, the liver, and the tumor. We also show a good correspondence between the time activity curves of the different regions obtained by using CA and manual region of interest analysis on dCLIT and PCA images. We conclude that CA provides an automatic unsupervised method for the analysis of preclinical dynamic Cerenkov luminescence image data.

  16. Dynamic fluorescence imaging with molecular agents for cancer detection

    NASA Astrophysics Data System (ADS)

    Kwon, Sun Kuk

    Non-invasive dynamic optical imaging of small animals requires the development of a novel fluorescence imaging modality. Herein, fluorescence imaging is demonstrated with sub-second camera integration times using agents specifically targeted to disease markers, enabling rapid detection of cancerous regions. The continuous-wave fluorescence imaging acquires data with an intensified or an electron-multiplying charge-coupled device. The work presented in this dissertation (i) assessed dose-dependent uptake using dynamic fluorescence imaging and pharmacokinetic (PK) models, (ii) evaluated disease marker availability in two different xenograft tumors, (iii) compared the impact of autofluorescence in fluorescence imaging of near-infrared (NIR) vs. red light excitable fluorescent contrast agents, (iv) demonstrated dual-wavelength fluorescence imaging of angiogenic vessels and lymphatics associated with a xenograft tumor model, and (v) examined dynamic multi-wavelength, whole-body fluorescence imaging with two different fluorescent contrast agents. PK analysis showed that the uptake of Cy5.5-c(KRGDf) in xenograft tumor regions linearly increased with doses of Cy5.5-c(KRGDf) up to 1.5 nmol/mouse. Above 1.5 nmol/mouse, the uptake did not increase with doses, suggesting receptor saturation. Target to background ratio (TBR) and PK analysis for two different tumor cell lines showed that while Kaposi's sarcoma (KS1767) exhibited early and rapid uptake of Cy5.5-c(KRGDf), human melanoma tumors (M21) had non-significant TBR differences and early uptake rates similar to the contralateral normal tissue regions. The differences may be due to different compartment location of the target. A comparison of fluorescence imaging with NIR vs. red light excitable fluorescent dyes demonstrates that NIR dyes are associated with less background signal, enabling rapid tumor detection. In contrast, animals injected with red light excitable fluorescent dyes showed high autofluorescence. Dual

  17. Renal expression of Toll-like receptor 2 and 4: dynamics in human allograft injury and comparison to rodents.

    PubMed

    Stribos, Elisabeth G D; van Werkhoven, Maaike B; Poppelaars, Felix; van Goor, Harry; Olinga, Peter; van Son, Willem J; Damman, Jeffrey; Seelen, Marc A

    2015-03-01

    Activation of the innate immunity through Toll-like receptors (TLRs) has been postulated to play an important role in the pathophysiology of renal allograft dysfunction. TLR2 and TLR4 dynamics in different human post-transplant pathological entities has never been studied. Therefore, we evaluated pre- and post-transplantation protein expression of TLR2 and TLR4 in human kidney biopsies. Human kidney biopsies obtained from living kidney donors and patients with acute tubular necrosis, acute cellular and vascular rejection and interstitial fibrosis/tubular atrophy (IF/TA) were used. Translating results from animal studies to the clinical situation is highly important considering the upcoming clinical studies with TLR inhibitors in human renal transplantation. Hence, the TLR2 and TLR4 expression in healthy mouse and rat kidneys was analyzed and compared with human kidneys. In healthy human kidneys, TLR2 is expressed on the endothelium and Bowman's capsule, while TLR4 is expressed on the endothelium only. No tubular staining was found for both receptors in human kidneys. In contrast to human biopsies, TLR2 and TLR4 expression in rodents was observed on tubular epithelial cells. In all acute rejection human biopsies, increased infiltration of TLR4(+) leukocytes was observed. In conclusion, a discrepancy exists between human and rodent renal TLR expression, which suggests careful attention when translating results from rodent studies to the human situation. Additionally, this study revealed human TLR2 and TLR4 expression dynamics in human biopsies pre- and post-transplantation.

  18. Radiogenomics of clear cell renal cell carcinoma: preliminary findings of The Cancer Genome Atlas–Renal Cell Carcinoma (TCGA–RCC) Imaging Research Group

    PubMed Central

    Shinagare, Atul B.; Vikram, Raghu; Jaffe, Carl; Akin, Oguz; Kirby, Justin; Huang, Erich; Freymann, John; Sainani, Nisha I.; Sadow, Cheryl A.; Bathala, Tharakeswara K.; Rubin, Daniel L.; Oto, Aytekin; Heller, Matthew T.; Surabhi, Venkateswar R.; Katabathina, Venkat; Silverman, Stuart G.

    2015-01-01

    Purpose To investigate associations between imaging features and mutational status of clear cell renal cell carcinoma (ccRCC). Materials and methods This multi-institutional, multi-reader study included 103 patients (77 men; median age 59 years, range 34–79) with ccRCC examined with CT in 81 patients, MRI in 19, and both CT and MRI in three; images were downloaded from The Cancer Imaging Archive, an NCI-funded project for genome-mapping and analyses. Imaging features [size (mm), margin (well-defined or ill-defined), composition (solid or cystic), necrosis (for solid tumors: 0%, 1%–33%, 34%–66% or >66%), growth pattern (endophytic, <50% exophytic, or ≥50% exophytic), and calcification (present, absent, or indeterminate)] were reviewed independently by three readers blinded to mutational data. The association of imaging features with mutational status (VHL, BAP1, PBRM1, SETD2, KDM5C, and MUC4) was assessed. Results Median tumor size was 49 mm (range 14–162 mm), 73 (71%) tumors had well-defined margins, 98 (95%) tumors were solid, 95 (92%) showed presence of necrosis, 46 (45%) had ≥50% exophytic component, and 18 (19.8%) had calcification. VHL (n = 52) and PBRM1 (n = 24) were the most common mutations. BAP1 mutation was associated with ill-defined margin and presence of calcification (p = 0.02 and 0.002, respectively, Pearson’s χ2 test); MUC4 mutation was associated with an exophytic growth pattern (p = 0.002, Mann–Whitney U test). Conclusions BAP1 mutation was associated with ill-defined tumor margins and presence of calcification; MUC4 mutation was associated with exophytic growth. Given the known prognostic implications of BAP1 and MUC4 mutations, these results support using radiogenomics to aid in prognostication and management. PMID:25753955

  19. Radiogenomics of clear cell renal cell carcinoma: preliminary findings of The Cancer Genome Atlas-Renal Cell Carcinoma (TCGA-RCC) Imaging Research Group.

    PubMed

    Shinagare, Atul B; Vikram, Raghu; Jaffe, Carl; Akin, Oguz; Kirby, Justin; Huang, Erich; Freymann, John; Sainani, Nisha I; Sadow, Cheryl A; Bathala, Tharakeswara K; Rubin, Daniel L; Oto, Aytekin; Heller, Matthew T; Surabhi, Venkateswar R; Katabathina, Venkat; Silverman, Stuart G

    2015-08-01

    To investigate associations between imaging features and mutational status of clear cell renal cell carcinoma (ccRCC). This multi-institutional, multi-reader study included 103 patients (77 men; median age 59 years, range 34-79) with ccRCC examined with CT in 81 patients, MRI in 19, and both CT and MRI in three; images were downloaded from The Cancer Imaging Archive, an NCI-funded project for genome-mapping and analyses. Imaging features [size (mm), margin (well-defined or ill-defined), composition (solid or cystic), necrosis (for solid tumors: 0%, 1%-33%, 34%-66% or >66%), growth pattern (endophytic, <50% exophytic, or ≥50% exophytic), and calcification (present, absent, or indeterminate)] were reviewed independently by three readers blinded to mutational data. The association of imaging features with mutational status (VHL, BAP1, PBRM1, SETD2, KDM5C, and MUC4) was assessed. Median tumor size was 49 mm (range 14-162 mm), 73 (71%) tumors had well-defined margins, 98 (95%) tumors were solid, 95 (92%) showed presence of necrosis, 46 (45%) had ≥50% exophytic component, and 18 (19.8%) had calcification. VHL (n = 52) and PBRM1 (n = 24) were the most common mutations. BAP1 mutation was associated with ill-defined margin and presence of calcification (p = 0.02 and 0.002, respectively, Pearson's χ (2) test); MUC4 mutation was associated with an exophytic growth pattern (p = 0.002, Mann-Whitney U test). BAP1 mutation was associated with ill-defined tumor margins and presence of calcification; MUC4 mutation was associated with exophytic growth. Given the known prognostic implications of BAP1 and MUC4 mutations, these results support using radiogenomics to aid in prognostication and management.

  20. High dynamic range infrared radiometry and imaging

    NASA Technical Reports Server (NTRS)

    Coon, Darryl D.; Karunasiri, R. P. G.; Bandara, K. M. S. V.

    1988-01-01

    The use is described of cryogenically cooled, extrinsic silicon infrared detectors in an unconventional mode of operation which offers an unusually large dynamic range. The system performs intensity-to-frequency conversion at the focal plane via simple circuits with very low power consumption. The incident IR intensity controls the repetition rate of short duration output pulses over a pulse rate dynamic range of about 10(6). Theory indicates the possibility of monotonic and approx. linear response over the full dynamic range. A comparison between the theoretical and the experimental results shows that the model provides a reasonably good description of experimental data. Some measurements of survivability with a very intense IR source were made on these devices and found to be very encouraging. Evidence continues to indicate that some variations in interpulse time intervals are deterministic rather than probabilistic.

  1. Assessment of Renal Hemodynamics and Oxygenation by Simultaneous Magnetic Resonance Imaging (MRI) and Quantitative Invasive Physiological Measurements.

    PubMed

    Cantow, Kathleen; Arakelyan, Karen; Seeliger, Erdmann; Niendorf, Thoralf; Pohlmann, Andreas

    2016-01-01

    In vivo assessment of renal perfusion and oxygenation under (patho)physiological conditions by means of noninvasive diagnostic imaging is conceptually appealing. Blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) and quantitative parametric mapping of the magnetic resonance (MR) relaxation times T 2* and T 2 are thought to provide surrogates of renal tissue oxygenation. The validity and efficacy of this technique for quantitative characterization of local tissue oxygenation and its changes under different functional conditions have not been systematically examined yet and remain to be established. For this purpose, the development of an integrative multimodality approaches is essential. Here we describe an integrated hybrid approach (MR-PHYSIOL) that combines established quantitative physiological measurements with T 2* (T 2) mapping and MR-based kidney size measurements. Standardized reversible (patho)physiologically relevant interventions, such as brief periods of aortic occlusion, hypoxia, and hyperoxia, are used for detailing the relation between the MR-PHYSIOL parameters, in particular between renal T 2* and tissue oxygenation.

  2. Fluid dynamic modelling of renal pelvic pressure during endoscopic stone removal

    NASA Astrophysics Data System (ADS)

    Oratis, Alexandros; Subasic, John; Bird, James; Eisner, Brian

    2015-11-01

    Endoscopic kidney stone removal procedures are known to increase internal pressure in the renal pelvis, the kidney's urinary collecting system. High renal pelvic pressure incites systemic absorption of irrigation fluid, which can increase the risk of postoperative fever and sepsis or the unwanted absorption of electrolytes. Urologists choose the appropriate surgical procedure based on patient history and kidney stone size. However, no study has been conducted to compare the pressure profiles of each procedure, nor is there a precise sense of how the renal pelvic pressure scales with various operational parameters. Here we develop physical models for the flow rates and renal pelvic pressure for various procedures. We show that the results of our models are consistent with existing urological data on each procedure and that the models can predict pressure profiles where data is unavailable.

  3. Multiresolution imaging using golden angle stack-of-stars and compressed sensing for dynamic MR urography.

    PubMed

    Pandey, Abhishek; Yoruk, Umit; Keerthivasan, Mahesh; Galons, Jean-Philippe; Sharma, Puneet; Johnson, Kevin; Martin, Diego R; Altbach, Maria I; Bilgin, Ali; Saranathan, Manojkumar

    2017-07-01

    To develop a novel multiresolution MRI methodology for accurate estimation of glomerular filtration rate (GFR) in vivo. A three-dimensional golden-angle radial stack-of-stars (SoS) trajectory was used for data acquisition on a 3 Tesla MRI scanner. Multiresolution reconstruction and analysis was performed using arterial input function reconstructed at 1-s. temporal resolution and renal dynamic data reconstructed using compressed sensing (CS) with 4-s temporal resolution. The method was first validated using simulations and the clinical utility of the technique was evaluated by comparing the GFR estimates from the proposed method to the estimated GFR (eGFR) obtained from serum creatinine for 10 subjects. The 4-s temporal resolution CS images minimized streaking artifacts and noise while the 1-s temporal resolution AIF minimized errors in GFR estimates. A paired t-test showed that there was no statistically significant difference between MRI based total GFR values and serum creatinine based eGFR estimates (P = 0.92). We have demonstrated the feasibility of multiresolution MRI using a golden angle radial stack-of-stars scheme to accurately estimate GFR as well as produce diagnostic quality dynamic images in vivo. 1 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2017;46:303-311. © 2017 International Society for Magnetic Resonance in Medicine.

  4. Non-destructive Faraday imaging of dynamically controlled ultracold atoms

    SciTech Connect

    Gajdacz, Miroslav; Pedersen, Poul L.; Mørch, Troels; Hilliard, Andrew J.; Arlt, Jan; Sherson, Jacob F.

    2013-08-15

    We describe an easily implementable method for non-destructive measurements of ultracold atomic clouds based on dark field imaging of spatially resolved Faraday rotation. The signal-to-noise ratio is analyzed theoretically and, in the absence of experimental imperfections, the sensitivity limit is found to be identical to other conventional dispersive imaging techniques. The dependence on laser detuning, atomic density, and temperature is characterized in a detailed comparison with theory. Due to low destructiveness, spatially resolved images of the same cloud can be acquired up to 2000 times. The technique is applied to avoid the effect of shot-to-shot fluctuations in atom number calibration, to demonstrate single-run vector magnetic field imaging and single-run spatial imaging of the system's dynamic behavior. This demonstrates that the method is a useful tool for the characterization of static and dynamically changing properties of ultracold atomic clouds.

  5. Efficient sinogram smoothing for dynamic neuroreceptor PET imaging

    NASA Astrophysics Data System (ADS)

    Pan, Xiaochuan; La Riviere, Patrick J.; Ye, James; Mukherjee, J.; Chen, Chin-Tu

    1997-05-01

    We have developed image-restoration techniques applicable to dynamic positron emission tomography that improve the visual quality and quantitative accuracy of neuroreceptor images. Starting wit data from a study of dopamine D-2 receptors in rhesus monkey striata using selective radioligands such as fallypride, we performed a novel effective 3D smoothing of the dynamic sinogram at a much lower computational cost than a truly 3D, adaptive smoothing. The processed sinogram was then input to a standard filtered back-projection algorithm and the resulting images were sharper and less noisy than images reconstructed from the unprocessed sinogram. Simulations were performed and the radioligand binding curves extracted from the restored images were found to be smoother and more accurate than those extracted form the unprocessed reconstructions. Comparison was also made to reconstructions from sinograms processed by the principal component analysis/projection onto convex sets algorithm.

  6. Ultrasonic Imaging of Subsurface Objects Using Photorefractive Dynamic Holography

    SciTech Connect

    Deason, Vance Albert; Telschow, Kenneth Louis; Watson, Scott Marshall

    2001-07-01

    The INEEL has developed a photorefractive ultrasonic imaging technology that records both phase and amplitude of ultrasonic waves on the surface of solids. Phase locked dynamic holography provides full field images of these waves scattered from subsurface defects in solids, and these data are compared with theoretical predictions. Laser light reflected by a vibrating surface is imaged into a photorefractive material where it is mixed in a heterodyne technique with a reference wave. This demodulates the data and provides an image of the ultrasonic waves in either 2 wave or 4 wave mixing mode. These data images are recorded at video frame rates and show phase locked traveling or resonant acoustic waves. This technique can be used over a broad range of ultrasonic frequencies. Acoustic frequencies from 2 kHz to 10 MHz have been imaged, and a point measuring (non-imaging) version of the system has measured picometer amplitudes at 1 GHz.

  7. Dynamic feature analysis for Voyager at the Image Processing Laboratory

    NASA Technical Reports Server (NTRS)

    Yagi, G. M.; Lorre, J. J.; Jepsen, P. L.

    1978-01-01

    Voyager 1 and 2 were launched from Cape Kennedy to Jupiter, Saturn, and beyond on September 5, 1977 and August 20, 1977. The role of the Image Processing Laboratory is to provide the Voyager Imaging Team with the necessary support to identify atmospheric features (tiepoints) for Jupiter and Saturn data, and to analyze and display them in a suitable form. This support includes the software needed to acquire and store tiepoints, the hardware needed to interactively display images and tiepoints, and the general image processing environment necessary for decalibration and enhancement of the input images. The objective is an understanding of global circulation in the atmospheres of Jupiter and Saturn. Attention is given to the Voyager imaging subsystem, the Voyager imaging science objectives, hardware, software, display monitors, a dynamic feature study, decalibration, navigation, and data base.

  8. Fat poor angiomyolipoma differentiation from renal cell carcinoma at 320-slice dynamic volume CT perfusion.

    PubMed

    Chen, Chao; Kang, Qinqin; Xu, Bing; Shi, Zhang; Guo, Hairuo; Wei, Qiang; Lu, Yayun; Wu, Xinhuai

    2017-08-21

    To compare various CT perfusion features of fat poor angiomyolipoma (AML) with those of size-matched renal cell carcinoma (RCC). One hundred and seventy-four patients [16 with fat poor AML (mean diameter, 3.1 cm; range, 1.5-5.5 cm) and 158 with RCC (mean diameter, 3.2 cm; range, 2.4-5.4 cm)] who had undergone 320-slice dynamic volume CT perfusion were evaluated. Equivalent blood volume (BV Equiv), permeability surface-area product (PS), and blood flow (BF) of tumor were measured and analyzed. Fat poor AML was compared with each subtype of RCC (132 clear cell, 9 papillary, and 17 chromophobe). Receiver operating characteristic (ROC) curve analysis was performed for the comparison of fat poor AML and RCC. ROC curve analysis was not performed for the papillary RCC subtype because of the small number of masses of this subtype. BV Equiv and BF were significantly lower in fat poor AML than in clear cell RCC (P < 0.05 for both). Fat poor AML had higher BV Equiv, PS, and BF than papillary RCC (P < 0.05 for all). PS and BF in fat poor AML significantly exceeded those in chromophobe RCC (P < 0.05 for both). For differentiating fat poor AML from clear cell RCC, area under the ROC curve (AUC) of BV Equiv and BF were 0.82 and 0.69. Using the optimal threshold value, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 0.82, 0.81, 0.35, 0.97 for BV Equiv and 0.71, 0.75, 0.24, 0.96 for BF, respectively. For differentiating fat poor AML from chromophobe RCC, AUC of PS and BF were 0.77 and 0.79, respectively. The optimal sensitivity, specificity, PPV, and NPV were 0.77, 0.75, 0.75, 0.76 for PS and 0.71, 0.81, 0.72, 0.80 for BF, respectively. Fat poor AML and subtypes of RCCs demonstrate different perfusion features at 320-slice dynamic volume CT, allowing their differentiations with BV Equiv, PS, and BF being valuable perfusion parameters.

  9. Imaging diagnosis--Ultrasound-guided ethanol sclerotherapy for a simple renal cyst.

    PubMed

    Agut, Amalia; Soler, Marta; Laredo, Francisco G; Pallares, Francisco J; Seva, Juan I

    2008-01-01

    Solitary renal cysts are benign and in the majority of instances asymptomatic and do not require treatment. Nevertheless, treatment may be required if abdominal discomfort or pain, hypertension, infection or renal outflow obstruction occur. Under these circumstances, percutaneous management of the cyst is the easiest and fastest procedure, and no major complications are generally encountered. In this report we describe a patient with a solitary renal cyst treated successfully by a single injection of ethanol into the cyst. The sonographic appearance of the cyst changed from a well-defined hypoechoic structure to an ill-defined hyperechoic region. Canine renal cysts may be successfully managed in some instances by a single ethanol injection.

  10. Dynamic PET Image reconstruction for parametric imaging using the HYPR kernel method

    NASA Astrophysics Data System (ADS)

    Spencer, Benjamin; Qi, Jinyi; Badawi, Ramsey D.; Wang, Guobao

    2017-03-01

    Dynamic PET image reconstruction is a challenging problem because of the ill-conditioned nature of PET and the lowcounting statistics resulted from short time-frames in dynamic imaging. The kernel method for image reconstruction has been developed to improve image reconstruction of low-count PET data by incorporating prior information derived from high-count composite data. In contrast to most of the existing regularization-based methods, the kernel method embeds image prior information in the forward projection model and does not require an explicit regularization term in the reconstruction formula. Inspired by the existing highly constrained back-projection (HYPR) algorithm for dynamic PET image denoising, we propose in this work a new type of kernel that is simpler to implement and further improves the kernel-based dynamic PET image reconstruction. Our evaluation study using a physical phantom scan with synthetic FDG tracer kinetics has demonstrated that the new HYPR kernel-based reconstruction can achieve a better region-of-interest (ROI) bias versus standard deviation trade-off for dynamic PET parametric imaging than the post-reconstruction HYPR denoising method and the previously used nonlocal-means kernel.

  11. Technetium Tc 99m dimercaptosuccinic acid renal scintigraphy in children with acute pyelonephritis: correlation with other imaging tests.

    PubMed

    Mohkam, Masoumeh; Maham, Saiid; Rahmani, Afrand; Naghi, Ilana; Otokesh, Babak; Raiiati, Hamid; Mohseni, Nima; Shamshiri, Ahmad Reza; Sharifian, Mostafa; Dalirani, Reza; Ghazi, Ruhollah; Ahoopai, Majid

    2010-10-01

    INTRODUCTION. Urinary tract infection is the most common serious bacterial infection in children. The aim of this study was to compare the value of different laboratory and imaging techniques in detecting renal involvement in acute pyelonephritis. MATERIALS AND METHODS. In a cross-sectional study of patients 1 month to 14 years of age diagnosed with urinary tract infection were examined with systemic inflammatory markers, renal ultrasonography, voiding cystourethrography (VCUG), and technetium Tc 99m dimercaptosuccinic acid ((99m)Tc-DMSA) renal scintigraphy. A total of 1467 pediatric patients were eligible for treatment of pyelonephritis. Evaluations included a complete blood count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), urinalysis, urine culture, and measurement of serum blood urea nitrogen and creatinine levels. RESULTS. The results of (99m)Tc-DMSA scans were normal in 20.2%, mild decreased cortical uptake in 45.0%, moderate decreased cortical uptake in 12.3%, severe decreased cortical uptake in 12.0%, and decreased cortical function plus irregularity or scar formation in 10.5%. Voiding cystourethrography showed vesicoureteral reflux in 25.9%. The sensitivity of (99m)Tc-DMSA for prediction of vesicoureteral reflux was 84.1% with a negative predictive value of 80.6%. Significant differences were found in the level of blood leukocyte count (P = .03), urine leukocyte count (P = .003), ESR (P = .008), and age (P = .04) between patients with normal and abnormal (99m)Tc-DMSA scan results. CONCLUSIONS. We found that in patient with clinical signs of pyelonephritis, (99m)Tc-DMSA renal scintigraphy can detect pyelonephritis more accurately than the other inflammatory and imaging tests.

  12. 3D element imaging using NSECT for the detection of renal cancer: a simulation study in MCNP.

    PubMed

    Viana, R S; Agasthya, G A; Yoriyaz, H; Kapadia, A J

    2013-09-07

    This work describes a simulation study investigating the application of neutron stimulated emission computed tomography (NSECT) for noninvasive 3D imaging of renal cancer in vivo. Using MCNP5 simulations, we describe a method of diagnosing renal cancer in the body by mapping the 3D distribution of elements present in tumors using the NSECT technique. A human phantom containing the kidneys and other major organs was modeled in MCNP5. The element composition of each organ was based on values reported in literature. The two kidneys were modeled to contain elements reported in renal cell carcinoma (RCC) and healthy kidney tissue. Simulated NSECT scans were executed to determine the 3D element distribution of the phantom body. Elements specific to RCC and healthy kidney tissue were then analyzed to identify the locations of the diseased and healthy kidneys and generate tomographic images of the tumor. The extent of the RCC lesion inside the kidney was determined using 3D volume rendering. A similar procedure was used to generate images of each individual organ in the body. Six isotopes were studied in this work - (32)S, (12)C, (23)Na, (14)N, (31)P and (39)K. The results demonstrated that through a single NSECT scan performed in vivo, it is possible to identify the location of the kidneys and other organs within the body, determine the extent of the tumor within the organ, and to quantify the differences between cancer and healthy tissue-related isotopes with p ≤ 0.05. All of the images demonstrated appropriate concentration changes between the organs, with some discrepancy observed in (31)P, (39)K and (23)Na. The discrepancies were likely due to the low concentration of the elements in the tissue that were below the current detection sensitivity of the NSECT technique.

  13. 3D element imaging using NSECT for the detection of renal cancer: a simulation study in MCNP

    NASA Astrophysics Data System (ADS)

    Viana, R. S.; Agasthya, G. A.; Yoriyaz, H.; Kapadia, A. J.

    2013-09-01

    This work describes a simulation study investigating the application of neutron stimulated emission computed tomography (NSECT) for noninvasive 3D imaging of renal cancer in vivo. Using MCNP5 simulations, we describe a method of diagnosing renal cancer in the body by mapping the 3D distribution of elements present in tumors using the NSECT technique. A human phantom containing the kidneys and other major organs was modeled in MCNP5. The element composition of each organ was based on values reported in literature. The two kidneys were modeled to contain elements reported in renal cell carcinoma (RCC) and healthy kidney tissue. Simulated NSECT scans were executed to determine the 3D element distribution of the phantom body. Elements specific to RCC and healthy kidney tissue were then analyzed to identify the locations of the diseased and healthy kidneys and generate tomographic images of the tumor. The extent of the RCC lesion inside the kidney was determined using 3D volume rendering. A similar procedure was used to generate images of each individual organ in the body. Six isotopes were studied in this work—32S, 12C, 23Na, 14N, 31P and 39K. The results demonstrated that through a single NSECT scan performed in vivo, it is possible to identify the location of the kidneys and other organs within the body, determine the extent of the tumor within the organ, and to quantify the differences between cancer and healthy tissue-related isotopes with p ≤ 0.05. All of the images demonstrated appropriate concentration changes between the organs, with some discrepancy observed in 31P, 39K and 23Na. The discrepancies were likely due to the low concentration of the elements in the tissue that were below the current detection sensitivity of the NSECT technique.

  14. The accuracy of quantitative parameters in (99m) Tc-MAG3 dynamic renography: a national audit based on virtual image data.

    PubMed

    Brolin, Gustav; Edenbrandt, Lars; Granerus, Göran; Olsson, Anna; Afzelius, David; Gustafsson, Agneta; Jonsson, Cathrine; Hagerman, Jessica; Johansson, Lena; Riklund, Katrine; Ljungberg, Michael

    2016-03-01

    Assessment of image analysis methods and computer software used in (99m) Tc-MAG3 dynamic renography is important to ensure reliable study results and ultimately the best possible care for patients. In this work, we present a national multicentre study of the quantification accuracy in (99m) Tc-MAG3 renography, utilizing virtual dynamic scintigraphic data obtained by Monte Carlo-simulated scintillation camera imaging of digital phantoms with time-varying activity distributions. Three digital phantom studies were distributed to the participating departments, and quantitative evaluation was performed with standard clinical software according to local routines. The differential renal function (DRF) and time to maximum renal activity (Tmax ) were reported by 21 of the 28 Swedish departments performing (99m) Tc-MAG3 studies as of 2012. The reported DRF estimates showed a significantly lower precision for the phantom with impaired renal uptake than for the phantom with normal uptake. The Tmax estimates showed a similar trend, but the difference was only significant for the right kidney. There was a significant bias in the measured DRF for all phantoms caused by different positions of the left and right kidney in the anterior-posterior direction. In conclusion, this study shows that virtual scintigraphic studies are applicable for quality assurance and that there is a considerable uncertainty associated with standard quantitative parameters in dynamic (99m) Tc-MAG3 renography, especially for patients with impaired renal function.

  15. Millimeter-wave spotlight imager using dynamic holographic metasurface antennas.

    PubMed

    Yurduseven, Okan; Marks, Daniel L; Fromenteze, Thomas; Gollub, Jonah N; Smith, David R

    2017-07-24

    Computational imaging systems leverage generalized measurements to produce high-fidelity images, enabling novel and often lower cost hardware platforms at the expense of increased processing. However, obtaining full resolution images across a large field-of-view (FOV) can lead to slow reconstruction times, limiting system performance where faster frame rates are desired. In many imaging scenarios, the highest resolution is needed only in smaller subdomains of interest within a scene, suggesting an aperture supporting multiple modalities of image capture with different resolutions can provide a path to system optimization. We explore this concept in the context of millimeter-wave imaging, presenting the design and simulation of a single frequency (75 GHz), multistatic, holographic spotlight aperture integrated into a K-band (17.5-26.5 GHz), frequency-diverse imager. The spotlight aperture - synthesized using an array of dynamically tuned, holographic, metasurface antennas - illuminates a constrained region-of-interest (ROI) identified from a low-resolution image, extracting a high-fidelity image of the constrained-ROI with a minimum number of measurement modes. The designs of both the static, frequency-diverse sub-aperture and the integrated dynamic spotlight aperture are evaluated using simulation techniques developed for large-scale synthetic apertures.

  16. Imaging the dynamics of individual electropores

    PubMed Central

    Sengel, Jason T.

    2016-01-01

    Electroporation is a widely used technique to permeabilize cell membranes. Despite its prevalence, our understanding of the mechanism of voltage-mediated pore formation is incomplete; methods capable of visualizing the time-dependent behavior of individual electropores would help improve our understanding of this process. Here, using optical single-channel recording, we track multiple isolated electropores in real time in planar droplet interface bilayers. We observe individual, mobile defects that fluctuate in size, exhibiting a range of dynamic behaviors. We observe fast (25 s−1) and slow (2 s−1) components in the gating of small electropores, with no apparent dependence on the applied potential. Furthermore, we find that electropores form preferentially in the liquid disordered phase. Our observations are in general supportive of the hydrophilic toroidal pore model of electroporation, but also reveal additional complexity in the interactions, dynamics, and energetics of electropores. PMID:27114528

  17. High Dynamic Range Digital Imaging of Spacecraft

    NASA Technical Reports Server (NTRS)

    Karr, Brian A.; Chalmers, Alan; Debattista, Kurt

    2014-01-01

    The ability to capture engineering imagery with a wide degree of dynamic range during rocket launches is critical for post launch processing and analysis [USC03, NNC86]. Rocket launches often present an extreme range of lightness, particularly during night launches. Night launches present a two-fold problem: capturing detail of the vehicle and scene that is masked by darkness, while also capturing detail in the engine plume.

  18. Fast imaging for mapping dynamic networks.

    PubMed

    LeVan, Pierre; Akin, Burak; Hennig, Jürgen

    2017-08-10

    The development of highly accelerated fMRI acquisition techniques has led to novel possibilities to monitor cerebral activity non-invasively and with unprecedented temporal resolutions. With the emergence of dynamic connectivity and its ability to provide a much richer characterization of brain function compared to static measures, fast fMRI may yet play a crucial role in tracking dynamically varying networks. In spite of the dominance of slow hemodynamic contributions to the BOLD signal, high temporal sampling rates nevertheless improve the measurement of physiological noise, yielding an exceptional sensitivity for the detection of periods of transient connectivity at time scales of a few tens of seconds. There is also evidence that relevant BOLD fluctuations are detectable at high frequencies, implying that the benefits of fast fMRI extend beyond the ability to sample nuisance confounds. Here we review the latest technological advancements that have established fast fMRI as an effective acquisition technique, as well as its current and future implications on the analysis of dynamic networks. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Dynamic imaging model and parameter optimization for a star tracker.

    PubMed

    Yan, Jinyun; Jiang, Jie; Zhang, Guangjun

    2016-03-21

    Under dynamic conditions, star spots move across the image plane of a star tracker and form a smeared star image. This smearing effect increases errors in star position estimation and degrades attitude accuracy. First, an analytical energy distribution model of a smeared star spot is established based on a line segment spread function because the dynamic imaging process of a star tracker is equivalent to the static imaging process of linear light sources. The proposed model, which has a clear physical meaning, explicitly reflects the key parameters of the imaging process, including incident flux, exposure time, velocity of a star spot in an image plane, and Gaussian radius. Furthermore, an analytical expression of the centroiding error of the smeared star spot is derived using the proposed model. An accurate and comprehensive evaluation of centroiding accuracy is obtained based on the expression. Moreover, analytical solutions of the optimal parameters are derived to achieve the best performance in centroid estimation. Finally, we perform numerical simulations and a night sky experiment to validate the correctness of the dynamic imaging model, the centroiding error expression, and the optimal parameters.

  20. Ship dynamics for maritime ISAR imaging.

    SciTech Connect

    Doerry, Armin Walter

    2008-02-01

    Demand is increasing for imaging ships at sea. Conventional SAR fails because the ships are usually in motion, both with a forward velocity, and other linear and angular motions that accompany sea travel. Because the target itself is moving, this becomes an Inverse- SAR, or ISAR problem. Developing useful ISAR techniques and algorithms is considerably aided by first understanding the nature and characteristics of ship motion. Consequently, a brief study of some principles of naval architecture sheds useful light on this problem. We attempt to do so here. Ship motions are analyzed for their impact on range-Doppler imaging using Inverse Synthetic Aperture Radar (ISAR). A framework for analysis is developed, and limitations of simple ISAR systems are discussed.

  1. The prognostic value of heart rate response during vasodilator stress myocardial perfusion imaging in patients with end-stage renal disease undergoing renal transplantation.

    PubMed

    AlJaroudi, Wael; Anokwute, Chiedozie; Fughhi, Ibtihaj; Campagnoli, Tania; Wassouf, Marwan; Vij, Aviral; Kharouta, Michael; Appis, Andrew; Ali, Amjad; Doukky, Rami

    2017-09-18

    In asymptomatic end-stage renal disease (ESRD) patients undergoing vasodilator stress myocardial perfusion imaging (MPI) prior to renal transplantation (RT), the impact of pre-transplant heart rate response (HRR) to vasodilator stress on post-RT outcomes is unknown. We analyzed a retrospective cohort of asymptomatic patients with ESRD who underwent a vasodilator stress SPECT-MPI and subsequently received RT. Blunted HRR was defined as HRR <28% for regadenoson stress and <20% for adenosine stress. The primary endpoint was major adverse cardiac events (MACE), defined as cardiac death or myocardial infarction. Clinical risk was assessed using the sum of risk factors set forth by the AHA/ACCF consensus statement on the assessment of RT candidates. Among 352 subjects, 140 had an abnormal pre-transplant HRR. During a mean follow-up of 3.2 ± 2.0 years, 85 (24%) MACEs were observed. Blunted HRR was associated with increased MACE risk (hazard ratio 1.72; 95% confidence interval 1.12-2.63, P = 0.013), and remained significant after adjustment for gender, sum of AHA/ACCF risk factors, summed stress score, baseline heart rate, and β-blocker use. HRR was predictive of MACE in patients with normal MPI and irrespective of clinical risk. Blunted HRR was associated with a significant increase in post-operative (30-day) MACE risk (17.9% vs 8.5%; P = 0.009). In asymptomatic ESRD patients being evaluated for RT, a blunted pre-transplant HRR was predictive of post-RT MACE. HRR may be a valuable tool in the risk assessment of RT candidates.

  2. Quantitative imaging of heterogeneous dynamics in drying and aging paints.

    PubMed

    van der Kooij, Hanne M; Fokkink, Remco; van der Gucht, Jasper; Sprakel, Joris

    2016-09-29

    Drying and aging paint dispersions display a wealth of complex phenomena that make their study fascinating yet challenging. To meet the growing demand for sustainable, high-quality paints, it is essential to unravel the microscopic mechanisms underlying these phenomena. Visualising the governing dynamics is, however, intrinsically difficult because the dynamics are typically heterogeneous and span a wide range of time scales. Moreover, the high turbidity of paints precludes conventional imaging techniques from reaching deep inside the paint. To address these challenges, we apply a scattering technique, Laser Speckle Imaging, as a versatile and quantitative tool to elucidate the internal dynamics, with microscopic resolution and spanning seven decades of time. We present a toolbox of data analysis and image processing methods that allows a tailored investigation of virtually any turbid dispersion, regardless of the geometry and substrate. Using these tools we watch a variety of paints dry and age with unprecedented detail.

  3. Quantitative imaging of heterogeneous dynamics in drying and aging paints

    PubMed Central

    van der Kooij, Hanne M.; Fokkink, Remco; van der Gucht, Jasper; Sprakel, Joris

    2016-01-01

    Drying and aging paint dispersions display a wealth of complex phenomena that make their study fascinating yet challenging. To meet the growing demand for sustainable, high-quality paints, it is essential to unravel the microscopic mechanisms underlying these phenomena. Visualising the governing dynamics is, however, intrinsically difficult because the dynamics are typically heterogeneous and span a wide range of time scales. Moreover, the high turbidity of paints precludes conventional imaging techniques from reaching deep inside the paint. To address these challenges, we apply a scattering technique, Laser Speckle Imaging, as a versatile and quantitative tool to elucidate the internal dynamics, with microscopic resolution and spanning seven decades of time. We present a toolbox of data analysis and image processing methods that allows a tailored investigation of virtually any turbid dispersion, regardless of the geometry and substrate. Using these tools we watch a variety of paints dry and age with unprecedented detail. PMID:27682840

  4. Quantitative imaging of heterogeneous dynamics in drying and aging paints

    NASA Astrophysics Data System (ADS)

    van der Kooij, Hanne M.; Fokkink, Remco; van der Gucht, Jasper; Sprakel, Joris

    2016-09-01

    Drying and aging paint dispersions display a wealth of complex phenomena that make their study fascinating yet challenging. To meet the growing demand for sustainable, high-quality paints, it is essential to unravel the microscopic mechanisms underlying these phenomena. Visualising the governing dynamics is, however, intrinsically difficult because the dynamics are typically heterogeneous and span a wide range of time scales. Moreover, the high turbidity of paints precludes conventional imaging techniques from reaching deep inside the paint. To address these challenges, we apply a scattering technique, Laser Speckle Imaging, as a versatile and quantitative tool to elucidate the internal dynamics, with microscopic resolution and spanning seven decades of time. We present a toolbox of data analysis and image processing methods that allows a tailored investigation of virtually any turbid dispersion, regardless of the geometry and substrate. Using these tools we watch a variety of paints dry and age with unprecedented detail.

  5. Feasibility of three-dimensional magnetic resonance angiography-fluoroscopy image fusion technique in guiding complex endovascular aortic procedures in patients with renal insufficiency.

    PubMed

    Schwein, Adeline; Chinnadurai, Ponraj; Shah, Dipan J; Lumsden, Alan B; Bechara, Carlos F; Bismuth, Jean

    2017-05-01

    Three-dimensional image fusion of preoperative computed tomography (CT) angiography with fluoroscopy using intraoperative noncontrast cone-beam CT (CBCT) has been shown to improve endovascular procedures by reducing procedure length, radiation dose, and contrast media volume. However, patients with a contraindication to CT angiography (renal insufficiency, iodinated contrast allergy) may not benefit from this image fusion technique. The primary objective of this study was to evaluate the feasibility of magnetic resonance angiography (MRA) and fluoroscopy image fusion using noncontrast CBCT as a guidance tool during complex endovascular aortic procedures, especially in patients with renal insufficiency. All endovascular aortic procedures done under MRA image fusion guidance at a single-center were retrospectively reviewed. The patients had moderate to severe renal insufficiency and underwent diagnostic contrast-enhanced magnetic resonance imaging after gadolinium or ferumoxytol injection. Relevant vascular landmarks electronically marked in MRA images were overlaid on real-time two-dimensional fluoroscopy for image guidance, after image fusion with noncontrast intraoperative CBCT. Technical success, time for image registration, procedure time, fluoroscopy time, number of digital subtraction angiography (DSA) acquisitions before stent deployment or vessel catheterization, and renal function before and after the procedure were recorded. The image fusion accuracy was qualitatively evaluated on a binary scale by three physicians after review of image data showing virtual landmarks from MRA on fluoroscopy. Between November 2012 and March 2016, 10 patients underwent endovascular procedures for aortoiliac aneurysmal disease or aortic dissection using MRA image fusion guidance. All procedures were technically successful. A paired t-test analysis showed no difference between preimaging and postoperative renal function (P = .6). The mean time required for MRA-CBCT image

  6. Is There Hope for Renal Growth on Imaging Studies Following Ureteral Reimplant for Boys With Fetal Hydronephrosis and Urinary Reflux?

    PubMed Central

    Wang, Ming-Hsien

    2015-01-01

    Reflux nephropathy is thought to be the etiology for renal maldevelopment. We present two boys with fetal hydronephrosis and sterile vesicoureteral reflux (VUR). There was lack of renal growth of the refluxing renal units on surveillance renal ultrasound. Parents elected to undergo open ureteral reimplants. Post-surgical ultrasounds demonstrated improved renal growth. PMID:26793522

  7. Direct Estimation of Kinetic Parametric Images for Dynamic PET

    PubMed Central

    Wang, Guobao; Qi, Jinyi

    2013-01-01

    Dynamic positron emission tomography (PET) can monitor spatiotemporal distribution of radiotracer in vivo. The spatiotemporal information can be used to estimate parametric images of radiotracer kinetics that are of physiological and biochemical interests. Direct estimation of parametric images from raw projection data allows accurate noise modeling and has been shown to offer better image quality than conventional indirect methods, which reconstruct a sequence of PET images first and then perform tracer kinetic modeling pixel-by-pixel. Direct reconstruction of parametric images has gained increasing interests with the advances in computing hardware. Many direct reconstruction algorithms have been developed for different kinetic models. In this paper we review the recent progress in the development of direct reconstruction algorithms for parametric image estimation. Algorithms for linear and nonlinear kinetic models are described and their properties are discussed. PMID:24396500

  8. Pulse sequence for dynamic volumetric imaging of hyperpolarized metabolic products

    NASA Astrophysics Data System (ADS)

    Cunningham, Charles H.; Chen, Albert P.; Lustig, Michael; Hargreaves, Brian A.; Lupo, Janine; Xu, Duan; Kurhanewicz, John; Hurd, Ralph E.; Pauly, John M.; Nelson, Sarah J.; Vigneron, Daniel B.

    2008-07-01

    Dynamic nuclear polarization and dissolution of a 13C-labeled substrate enables the dynamic imaging of cellular metabolism. Spectroscopic information is typically acquired, making the acquisition of dynamic volumetric data a challenge. To enable rapid volumetric imaging, a spectral-spatial excitation pulse was designed to excite a single line of the carbon spectrum. With only a single resonance present in the signal, an echo-planar readout trajectory could be used to resolve spatial information, giving full volume coverage of 32 × 32 × 16 voxels every 3.5 s. This high frame rate was used to measure the different lactate dynamics in different tissues in a normal rat model and a mouse model of prostate cancer.

  9. Pulse Sequence for Dynamic Volumetric Imaging of Hyperpolarized Metabolic Products

    PubMed Central

    Cunningham, Charles H.; Chen, Albert P.; Lustig, Michael; Lupo, Janine; Xu, Duan; Kurhanewicz, John; Hurd, Ralph E.; Pauly, John M.; Nelson, Sarah J.; Vigneron, Daniel B.

    2011-01-01

    Dynamic nuclear polarization and dissolution of a 13C-labeled substrate enables the dynamic imaging of cellular metabolism. Spectroscopic information is typically acquired, making the acquisition of dynamic volumetric data a challenge. To enable rapid volumetric imaging, a spectral-spatial excitation pulse was designed to excite a single line of the carbon spectrum. With only a single resonance present in the signal, an echo-planar readout trajectory could be used to resolve spatial information, giving full volume coverage of 32 × 32 × 16 voxels every 3.5 seconds. This high frame rate was used to measure the different lactate dynamics in different tissues in a normal rat model and a mouse model of prostate cancer. PMID:18424203

  10. Dynamic imaging of preimplantation embryos in the murine oviduct

    NASA Astrophysics Data System (ADS)

    Burton, Jason C.; Wang, Shang; Larina, Irina V.

    2015-03-01

    Studying the dynamic events involved in early preimplantation embryo development during their transport from the ovary to the uterus is of great significance to improve the understanding of infertility, and eventually to help reduce the infertility rate. The mouse is a widely used mammalian model in reproductive biology, however, dynamic imaging studies of mouse preimplantation embryos have been very limited due to the lack of proper imaging tools for such analysis. Here, we introduce an innovative approach, which can potentially be used for three-dimensional imaging and tracking of murine oocytes with optical coherence tomography (OCT) as they exit the ovary and migrate through the oviduct to the uterus. The imaging is performed with spectral-domain OCT system operating at 70 kHz A-scan rate. The preimplantation embryos and surrounding cumulus cells can be clearly visualized. Results from our experiments indicate that OCT has great potential for dynamic imaging of the oviduct and oocyte tracking, which provides the foundation for future investigations aimed at understanding dynamic events during preimplantation stages in normal development as well as in mouse models of infertility.

  11. Research on hyperspectral dynamic scene and image sequence simulation

    NASA Astrophysics Data System (ADS)

    Sun, Dandan; Gao, Jiaobo; Sun, Kefeng; Hu, Yu; Li, Yu; Xie, Junhu; Zhang, Lei

    2016-10-01

    This paper presents a simulation method of hyper-spectral dynamic scene and image sequence for hyper-spectral equipment evaluation and target detection algorithm. Because of high spectral resolution, strong band continuity, anti-interference and other advantages, in recent years, hyper-spectral imaging technology has been rapidly developed and is widely used in many areas such as optoelectronic target detection, military defense and remote sensing systems. Digital imaging simulation, as a crucial part of hardware in loop simulation, can be applied to testing and evaluation hyper-spectral imaging equipment with lower development cost and shorter development period. Meanwhile, visual simulation can produce a lot of original image data under various conditions for hyper-spectral image feature extraction and classification algorithm. Based on radiation physic model and material characteristic parameters this paper proposes a generation method of digital scene. By building multiple sensor models under different bands and different bandwidths, hyper-spectral scenes in visible, MWIR, LWIR band, with spectral resolution 0.01μm, 0.05μm and 0.1μm have been simulated in this paper. The final dynamic scenes have high real-time and realistic, with frequency up to 100 HZ. By means of saving all the scene gray data in the same viewpoint image sequence is obtained. The analysis results show whether in the infrared band or the visible band, the grayscale variations of simulated hyper-spectral images are consistent with the theoretical analysis results.

  12. Research on hyperspectral dynamic scene and image sequence simulation

    NASA Astrophysics Data System (ADS)

    Sun, Dandan; Liu, Fang; Gao, Jiaobo; Sun, Kefeng; Hu, Yu; Li, Yu; Xie, Junhu; Zhang, Lei

    2016-10-01

    This paper presents a simulation method of hyperspectral dynamic scene and image sequence for hyperspectral equipment evaluation and target detection algorithm. Because of high spectral resolution, strong band continuity, anti-interference and other advantages, in recent years, hyperspectral imaging technology has been rapidly developed and is widely used in many areas such as optoelectronic target detection, military defense and remote sensing systems. Digital imaging simulation, as a crucial part of hardware in loop simulation, can be applied to testing and evaluation hyperspectral imaging equipment with lower development cost and shorter development period. Meanwhile, visual simulation can produce a lot of original image data under various conditions for hyperspectral image feature extraction and classification algorithm. Based on radiation physic model and material characteristic parameters this paper proposes a generation method of digital scene. By building multiple sensor models under different bands and different bandwidths, hyperspectral scenes in visible, MWIR, LWIR band, with spectral resolution 0.01μm, 0.05μm and 0.1μm have been simulated in this paper. The final dynamic scenes have high real-time and realistic, with frequency up to 100 HZ. By means of saving all the scene gray data in the same viewpoint image sequence is obtained. The analysis results show whether in the infrared band or the visible band, the grayscale variations of simulated hyperspectral images are consistent with the theoretical analysis results.

  13. SYSTEMATIC DE-SATURATION OF IMAGES FROM THE ATMOSPHERIC IMAGING ASSEMBLY IN THE SOLAR DYNAMICS OBSERVATORY

    SciTech Connect

    Schwartz, R. A.; Torre, G.; Piana, M. E-mail: torre@dima.unige.it

    2014-10-01

    Extreme ultraviolet (EUV) images of solar flares provided by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) are often affected by saturation effects in their core, physically most interesting, region. We introduce an image reconstruction procedure that allows recovering information in the primary saturation domain using the secondary images produced by the diffraction fringes as input data. Such a procedure is based on standard image-processing tools like correlation, convolution, and back-projection. Its effectiveness is tested in the case of AIA/SDO observations of the 2013 July 8 flaring event.

  14. Geocoronal Imaging with Dynamics Explorer: A First Look.

    DTIC Science & Technology

    1982-09-01

    Geocoronal isophote contours for this image 4 are shown on Plate lb. Another set of contours indicates the angle through vhich photons from the sun...contribution we subtract background intensities derived from isophote contour maps published by Bertaux and Blamont [1973] and Thomas and Krassa [1971...returned by the University of Iowa spin-scan imaging system on board Dynamics Explorer-I, along with quantitative information in the form of an isophote

  15. Using surface deformation to image reservoir dynamics

    SciTech Connect

    Vasco, D.W.; Karasaki, K.; Doughty, C.

    2000-02-01

    The inversion of surface deformation data such as tilt, displacement, or strain provides a noninvasive method for monitoring subsurface volume change. Reservoir volume change is related directly to processes such as pressure variations induced by injection and withdrawal. The inversion procedure is illustrated by an application to tiltmeter data from the Hijiori test site in Japan. An inversion of surface tilt data allows one to image flow processes in a fractured granodiorite. Approximately 650 barrels of water, injected 2 km below the surface, produces a peak surface tilt of the order of 0.8 microradians. The authors find that the pattern of volume change in the granodiorite is very asymmetrical, elongated in a north-northwesterly direction, and the maximum volume change is offset by more than 0.7 km to the east of the pumping well. The inversion of a suite of leveling data from the Wilmington oil field in Long Beach, California, images large-scale reservoir volume changes in 12 one- to two-year increments from 1976 to 1996. The influence of various production strategies is seen in the reservoir volume changes. In particular, a steam flood in fault block 2 in the northwest portion of the field produced a sudden decrease in reservoir volume.

  16. Effects of exercise and excitement on mesenteric and renal dynamics in conscious, unrestrained baboons

    NASA Technical Reports Server (NTRS)

    Vatner, S. F.

    1978-01-01

    Radiotelemetry was used to measure arterial pressure and mesenteric and renal blood flows from nine unrestrained, conscious baboons during periods of rest, moderate exercise, and extreme excitement. A description of the experiments hardware is presented, including artificial depressants phenylcyclidine hydrochloride, 0.5-1.0 mg/kg, and pentobarbital sodium, 15 mg/kg, and an ultrasonic telemetry flow meter. Results showed rising heart rate and arterial pressure coupled with a reduction of mesenteric and renal flows as the level of exercise was increased. These findings are compared with mesenteric and renal flows somewhat above control level, but relatively stable heart rate and arterial pressure, postprandially. Attention is given to a quantitative analysis of the experimental results.

  17. Effects of exercise and excitement on mesenteric and renal dynamics in conscious, unrestrained baboons

    NASA Technical Reports Server (NTRS)

    Vatner, S. F.

    1978-01-01

    Radiotelemetry was used to measure arterial pressure and mesenteric and renal blood flows from nine unrestrained, conscious baboons during periods of rest, moderate exercise, and extreme excitement. A description of the experiments hardware is presented, including artificial depressants phenylcyclidine hydrochloride, 0.5-1.0 mg/kg, and pentobarbital sodium, 15 mg/kg, and an ultrasonic telemetry flow meter. Results showed rising heart rate and arterial pressure coupled with a reduction of mesenteric and renal flows as the level of exercise was increased. These findings are compared with mesenteric and renal flows somewhat above control level, but relatively stable heart rate and arterial pressure, postprandially. Attention is given to a quantitative analysis of the experimental results.

  18. Beneficial cardiovascular remodeling following arterio-venous fistula ligation post-renal transplantation: a longitudinal magnetic resonance imaging study.

    PubMed

    Dundon, Benjamin K; Torpey, David K; Nelson, Adam J; Wong, Dennis T L; Duncan, Rae F; Meredith, Ian T; Faull, Randall J; Worthley, Stephen G; Worthley, Matthew I

    2014-08-01

    Despite improvements in survival following renal transplantation, high rates of cardiovascular morbidity and mortality remain. Persistence of arterio-venous fistulae (AVF) may contribute to maladaptive cardiovascular remodeling and poor health outcomes in this cohort. Utilizing recent advances in cardiovascular magnetic resonance imaging (CMR), we prospectively evaluated alterations in cardiac and vascular structure and function six months after elective ligation of AVF, following stable, successful renal transplantation. Eighteen subjects underwent CMR evaluation of cardiac structure and function, aortic distensibility and endothelial function prior to AVF ligation and at six months. At follow-up, while left ventricular ejection fraction was unchanged, mean cardiac output decreased by 15.6% (9.6 ± 2.9 L/min vs. 8.1 ± 2.3 L/min, p = 0.004) and left ventricular mass had regressed by 10% (166 ± 56 g vs. 149 ± 51 g, p = 0.0001). Significant improvements were also noted in right ventricular and biatrial structure and function. Aortic distensibility was unchanged at follow-up, but endothelial dependent vasodilatation had improved (2.5 ± 6.5% vs. 8.0 ± 5.9%, p = 0.04). Elective AVF ligation following successful renal transplantation is associated with improvements in left ventricular mass, right ventricular, and biatrial structure and function. Further randomized studies are warranted to determine the potential clinical improvement following AVF ligation in this cohort. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Diabetic nephropathy and endothelial dysfunction: Current and future therapies, and emerging of vascular imaging for preclinical renal-kinetic study.

    PubMed

    Leung, Wilson Kc; Gao, L; Siu, Parco M; Lai, Christopher Wk

    2016-12-01

    An explosion in global epidemic of type 2 diabetes mellitus poses major rise in cases with vascular endothelial dysfunction ranging from micro- (retinopathy, nephropathy and neuropathy) to macro-vascular (atherosclerosis and cardiomyopathy) conditions. Functional destruction of endothelium is regarded as an early event that lays the groundwork for the development of renal microangiopathy and subsequent clinical manifestation of nephropathic symptoms. Recent research has shed some light on the molecular mechanisms of type 2 diabetes-associated comorbidity of endothelial dysfunction and nephropathy. Stemming from currently proposed endothelium-centered therapeutic strategies for diabetic nephropathy, this review highlighted some most exploited pathways that involve the intricate coordination of vasodilators, vasoconstrictors and vaso-modulatory molecules in the pathogenesis of diabetic nephropathy. We also emphasized the emerging roles of oxidative and epigenetic modifications of microvasculature as our prospective therapeutics for diabetic renal diseases. Finally, this review in particular addressed the potential use of multispectral optoacoustic tomography in real-time, minimally-invasive vascular imaging of small experimental animals for preclinical renal-kinetic drug trials.

  20. Accurate diagnosis of renal transplant rejection by indium-111 platelet imaging despite postoperative cyclosporin therapy

    SciTech Connect

    Collier, B.D.; Adams, M.B.; Kauffman, H.M.; Trembath, L.; Hoffmann, R.G.; Tisdale, P.L.; Rao, S.A.; Hellman, R.S.; Isitman, A.T.

    1988-08-01

    Previous reports indicate that In-111 platelet scintigraphy (IPS) is a reliable test for the early diagnosis of acute post-operative renal transplant rejection (TR). However, the recent introduction of cyclosporin for post-transplantation immunosuppression requires that the diagnostic efficacy of IPS once again be established. Therefore, a prospective IPS study of 73 post-operative renal transplant recipients was conducted. Fourty-nine patients received cyclosporin and 24 patients did not receive this drug. Between these two patient groups, there were no significant differences in the diagnostic sensitivities (0.86 vs 0.80) and specificities (0.93 vs 0.84) with which TR was identified. We conclude that during the first two weeks following renal transplantation the cyclosporin treatment regimen used at our institution does not limit the reliability of IPS as a test for TR.

  1. Overhauser dynamic nuclear polarization amplification of NMR flow imaging.

    PubMed

    Lingwood, Mark D; Sederman, Andrew J; Mantle, Mick D; Gladden, Lynn F; Han, Songi

    2012-03-01

    We describe the first study comparing the ability of phase shift velocity imaging and Overhauser dynamic nuclear polarization (DNP)-enhanced imaging to generate contrast for visualizing the flow of water. Prepolarization of water by the Overhauser DNP mechanism is performed in the 0.35T fringe field of an unshielded 2.0T non-clinical MRI magnet, followed by the rapid transfer of polarization-enhanced water to the 2.0T imaging location. This technique, previously named remotely enhanced liquids for image contrast (RELIC), produces a continuous flow of hyperpolarized water and gives up to an -8.2-fold enhanced signal within the image with respect to thermally polarized signal at 2.0T. Using flow through a cylindrical expansion phantom as a model system, spin-echo intensity images with DNP are compared to 3D phase shift velocity images to illustrate the complementary information available from the two techniques. The spin-echo intensity images enhanced with DNP show that the levels of enhancement provide an estimate of the transient propagation of flow, while the phase shift velocity images quantitatively measure the velocity of each imaging voxel. Phase shift velocity images acquired with and without DNP show that DNP weights velocity values towards those of the inflowing (DNP-enhanced) water, while velocity images without DNP more accurately reflect the average steady-state velocity of each voxel. We conclude that imaging with DNP prepolarized water better captures the transient path of water shortly after injection, while phase shift velocity imaging is best for quantifying the steady-state flow of water throughout the entire phantom. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. [Diagnostic imaging--CT, dynamic CT, and others].

    PubMed

    Kurosawa, Hajime

    2011-10-01

    Technical advances have raised computed tomography(CT) as a strong diagnostic tool of clinical imaging. Emphysematous changes can be quantitatively analyzed as low attenuation area which correlated with diffusion capacity, quality of life, and nutritional states, but not so much with forced expiratory volume in one second. With co-analyzing airway wall thickness, those are possibly useful to understand phenotypes. Dynamics of airway during breathing can be visualized by dynamic CT such as electron-beam CT. Dynamic airway narrowing is a representative feature in emphysematous lung.

  3. Non-Local Means Denoising of Dynamic PET Images

    PubMed Central

    Dutta, Joyita; Leahy, Richard M.; Li, Quanzheng

    2013-01-01

    Objective Dynamic positron emission tomography (PET), which reveals information about both the spatial distribution and temporal kinetics of a radiotracer, enables quantitative interpretation of PET data. Model-based interpretation of dynamic PET images by means of parametric fitting, however, is often a challenging task due to high levels of noise, thus necessitating a denoising step. The objective of this paper is to develop and characterize a denoising framework for dynamic PET based on non-local means (NLM). Theory NLM denoising computes weighted averages of voxel intensities assigning larger weights to voxels that are similar to a given voxel in terms of their local neighborhoods or patches. We introduce three key modifications to tailor the original NLM framework to dynamic PET. Firstly, we derive similarities from less noisy later time points in a typical PET acquisition to denoise the entire time series. Secondly, we use spatiotemporal patches for robust similarity computation. Finally, we use a spatially varying smoothing parameter based on a local variance approximation over each spatiotemporal patch. Methods To assess the performance of our denoising technique, we performed a realistic simulation on a dynamic digital phantom based on the Digimouse atlas. For experimental validation, we denoised PET images from a mouse study and a hepatocellular carcinoma patient study. We compared the performance of NLM denoising with four other denoising approaches – Gaussian filtering, PCA, HYPR, and conventional NLM based on spatial patches. Results The simulation study revealed significant improvement in bias-variance performance achieved using our NLM technique relative to all the other methods. The experimental data analysis revealed that our technique leads to clear improvement in contrast-to-noise ratio in Patlak parametric images generated from denoised preclinical and clinical dynamic images, indicating its ability to preserve image contrast and high

  4. Renal ablation using magnetic resonance-guided high intensity focused ultrasound: Magnetic resonance imaging and histopathology assessment

    PubMed Central

    Saeed, Maythem; Krug, Roland; Do, Loi; Hetts, Steven W; Wilson, Mark W

    2016-01-01

    AIM: To use magnetic resonance-guided high intensity focused ultrasound (MRg-HIFU), magnetic resonance imaging (MRI) and histopathology for noninvasively ablating, quantifying and characterizing ablated renal tissue. METHODS: Six anesthetized/mechanically-ventilated pigs underwent single/double renal sonication (n = 24) using a 3T-MRg-HIFU (1.1 MHz frequency and 3000J-4400J energies). T2-weighted fast spin echo (T2-W), perfusion saturation recovery gradient echo and contrast enhanced (CE) T1-weighted (T1-W) sequences were used for treatment planning, temperature monitoring, lesion visualization, characterization and quantification, respectively. Histopathology was conducted in excised kidneys to quantify and characterize cellular and vascular changes. Paired Student’s t-test was used and a P-value < 0.05 was considered statistically significant. RESULTS: Ablated renal parenchyma could not be differentiated from normal parenchyma on T2-W or non-CE T1-W sequences. Ablated renal lesions were visible as hypoenhanced regions on perfusion and CE T1-W MRI sequences, suggesting perfusion deficits and necrosis. Volumes of ablated parenchyma on CE T1-W images in vivo (0.12-0.36 cm3 for single sonication 3000J, 0.50-0.84 cm3, for double 3000J, 0.75-0.78 cm3 for single 4400J and 0.12-2.65 cm3 for double 4400J) and at postmortem (0.23-0.52 cm3, 0.25-0.82 cm3, 0.45-0.68 cm3 and 0.29-1.80 cm3, respectively) were comparable. The ablated volumes on 3000J and 4400J double sonication were significantly larger than single (P < 0.01), thus, the volume and depth of ablated tissue depends on the applied energy and number of sonication. Macroscopic and microscopic examinations confirmed the locations and presence of coagulation necrosis, vascular damage and interstitial hemorrhage, respectively. CONCLUSION: Contrast enhanced MRI provides assessment of MRg-HIFU renal ablation. Histopathology demonstrated coagulation necrosis, vascular damage and confirmed the volume of damage seen on MRI

  5. High dynamic range image compression by optimizing tone mapped image quality index.

    PubMed

    Ma, Kede; Yeganeh, Hojatollah; Zeng, Kai; Wang, Zhou

    2015-10-01

    Tone mapping operators (TMOs) aim to compress high dynamic range (HDR) images to low dynamic range (LDR) ones so as to visualize HDR images on standard displays. Most existing TMOs were demonstrated on specific examples without being thoroughly evaluated using well-designed and subject-validated image quality assessment models. A recently proposed tone mapped image quality index (TMQI) made one of the first attempts on objective quality assessment of tone mapped images. Here, we propose a substantially different approach to design TMO. Instead of using any predefined systematic computational structure for tone mapping (such as analytic image transformations and/or explicit contrast/edge enhancement), we directly navigate in the space of all images, searching for the image that optimizes an improved TMQI. In particular, we first improve the two building blocks in TMQI—structural fidelity and statistical naturalness components—leading to a TMQI-II metric. We then propose an iterative algorithm that alternatively improves the structural fidelity and statistical naturalness of the resulting image. Numerical and subjective experiments demonstrate that the proposed algorithm consistently produces better quality tone mapped images even when the initial images of the iteration are created by the most competitive TMOs. Meanwhile, these results also validate the superiority of TMQI-II over TMQI.

  6. Image Familiarization Sharpens Response Dynamics of Neurons in Inferotemporal Cortex

    PubMed Central

    Meyer, Travis; Walker, Christopher; Cho, Raymond Y.; Olson, Carl R.

    2015-01-01

    Repeated viewing of an image over days and weeks induces a marked reduction in the strength with which neurons in monkey inferotemporal cortex respond to it. The processing advantage that attaches to this reduction is unknown. One possibility is that truncation of the response to a familiar image leaves neurons in a state of readiness to respond to ensuing images and thus enhances their ability to track rapidly changing displays. We have explored this possibility by assessing neuronal responses to familiar and novel images in rapid serial visual displays. Inferotemporal neurons respond more strongly to familiar than to novel images in such displays. The effect is stronger among putative inhibitory neurons than among putative excitatory neurons. A comparable effect occurs at the level of the scalp potential in humans. We conclude that long-term familiarization sharpens the response dynamics of neurons in both monkey and human extrastriate visual cortex. PMID:25151263

  7. Raman imaging of molecular dynamics during cellular events

    NASA Astrophysics Data System (ADS)

    Fujita, Katsumasa

    2017-07-01

    To overcome the speed limitation in Raman imaging, we have developed a microscope system that detects Raman spectra from hundreds of points in a sample simultaneously. The sample was illuminated by a line-shaped focus, and Raman scattering from the illuminated positions was measured simultaneously by an imaging spectrophotometer. We applied the line-illumination technique to observe the dynamics of intracellular molecules during cellular events. We found that intracellular cytochrome c can be clearly imaged by resonant Raman scattering. We demonstrated label-free imaging of redistribution of cytochrome c during apoptosis and osteoblastic mineralization. We also proposed alkyne-tagged Raman imaging to observe small molecules in living cells. Due to its small size and the unique Raman band, alkyne can tag molecules without strong perturbation to molecular functions and with the capability to be detected separately from endogenous molecules.

  8. Renal Blood Oxygenation Level-dependent Imaging in Longitudinal Follow-up of Donated and Remaining Kidneys.

    PubMed

    Seif, Maryam; Eisenberger, Ute; Binser, Tobias; Thoeny, Harriet C; Krauer, Fabienne; Rusch, Aurelia; Boesch, Chris; Vogt, Bruno; Vermathen, Peter

    2016-06-01

    Purpose To determine renal oxygenation changes associated with uninephrectomy and transplantation in both native donor kidneys and transplanted kidneys by using blood oxygenation level-dependent (BOLD) MR imaging. Materials and Methods The study protocol was approved by the local ethics committee. Thirteen healthy kidney donors and their corresponding recipients underwent kidney BOLD MR imaging with a 3-T imager. Written informed consent was obtained from each subject. BOLD MR imaging was performed in donors before uninephrectomy and in donors and recipients 8 days, 3 months, and 12 months after transplantation. R2* values, which are inversely related to tissue partial pressure of oxygen, were determined in the cortex and medulla. Longitudinal R2* changes were statistically analyzed by using repeated measures one-way analysis of variance with post hoc pair-wise comparisons. Results R2* values in the remaining kidneys significantly decreased early after uninephrectomy in both the medulla and cortex (P < .003), from 28.9 sec(-1) ± 2.3 to 26.4 sec(-1) ± 2.5 in the medulla and from 18.3 sec(-1) ± 1.5 to 16.3 sec(-1) ± 1.0 in the cortex, indicating increased oxygen content. In donors, R2* remained significantly decreased in both the medulla and cortex at 3 (P < .01) and 12 (P < .01) months. In transplanted kidneys, R2* remained stable during the first year after transplantation, with no significant change. Among donors, cortical R2* was found to be negatively correlated with estimated glomerular filtration rate (R = -0.47, P < .001). Conclusion The results suggest that BOLD MR imaging may potentially be used to monitor renal functional changes in both remaining and corresponding transplanted kidneys. (©) RSNA, 2016.

  9. Differences in Renal Tumor Size Measurements for Computed Tomography Versus Magnetic Resonance Imaging: Implications for Patients on Active Surveillance.

    PubMed

    Khan, Irtaza; Beksac, Alp Tuna; Paulucci, David J; Abaza, Ronney; Eun, Daniel D; Bhandari, Akshay; Badani, Ketan K

    2017-08-11

    To evaluate and compare the accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in predicting the final pathologic tumor size of partial nephrectomy specimens. We analyzed a multi-institutional database of 807 patients who underwent robotic partial nephrectomy for a cT1a renal mass from 2006 to 2016. Patients who had a solitary tumor with complete data on the baseline imaging modality and the tumor size (baseline and pathologic) (n = 349) were included for analysis. Baseline tumor size evaluated by both imaging modalities, in addition to the difference between the measurements and final pathologic tumor size (cm) measurements, was compared between patients who received a baseline CT (n = 276, 79.1%) and those who received an MRI (n = 73, 20.9%). There were no statistically significant differences between any baseline characteristics and receipt of a CT versus MRI. In multivariable analysis adjusting for confounders, there was no significant difference in the baseline tumor size between patients receiving an MRI and those receiving a CT (2.3 versus 2.6 cm; β = -0.13; 95% confidence interval [CI] = -0.33 to 0.07; P = .208). Tumor size on imaging was smaller from final pathology by 0.43 cm on average (P = .002). Measurement error for the measured baseline versus actual pathologic tumor size did not significantly differ for patients receiving an MRI versus those receiving a CT (0.38 versus 0.44 cm; β = -0.06; 95% CI = -0.16 to 0.04; P = .232). Baseline renal tumor size measurements were not significantly different for CT scan and MRI. Choice of imaging modality can be based on doctor and patient preference, including cost and exposure to radiation.

  10. Dynamic algorithm selection for multi-sensor image registration

    NASA Astrophysics Data System (ADS)

    DelMarco, Stephen; Tom, Victor; Webb, Helen; Lefebvre, David

    2009-05-01

    Modern sensors have a range of modalities including SAR, EO, and IR. Registration of multimodal imagery from such sensors is becoming an increasingly common pre-processing step for various image exploitation activities such as image fusion for ATR. Over the past decades, several approaches to multisensor image registration have been developed. However, performance of these image registration algorithms is highly dependent on scene content and sensor operating conditions, with no single algorithm working well across the entire operating conditions space. To address this problem, in this paper we present an approach for dynamic selection of an appropriate registration algorithm, tuned to the scene content and feature manifestation of the imagery under consideration. We consider feature-based registration using Harris corners, Canny edge detection, and CFAR features, as well as pixel-based registration using cross-correlation and mutual information. We develop an approach for selecting the optimal combination of algorithms to use in the dynamic selection algorithm. We define a performance measure which balances contributions from convergence redundancy and convergence coverage components calculated over sample imagery, and optimize the measure to define an optimal algorithm set. We present numerical results demonstrating the improvement in registration performance through use of the dynamic algorithm selection approach over results generated through use of a fixed registration algorithm approach. The results provide registration convergence probabilities for geo-registering test SAR imagery against associated EO reference imagery. We present convergence results for various match score normalizations used in the dynamic selection algorithm.

  11. Computer simulation and image guidance for individualised dynamic spinal stabilization.

    PubMed

    Kantelhardt, S R; Hausen, U; Kosterhon, M; Amr, A N; Gruber, K; Giese, A

    2015-08-01

    Dynamic implants for the human spine are used to re-establish regular segmental motion. However, the results have often been unsatisfactory and complications such as screw loosening are common. Individualisation of appliances and precision implantation are needed to improve the outcome of this procedure. Computer simulation, virtual implant optimisation and image guidance were used to improve the technique. A human lumbar spine computer model was developed using multi-body simulation software. The model simulates spinal motion under load and degenerative changes. After virtual degeneration of a L4/5 segment, virtual pedicle screw-based implants were introduced. The implants' positions and properties were iteratively optimised. The resulting implant positions were used as operative plan for image guidance and finally implemented in a physical spine model. In the simulation, the introduction and optimisation of virtually designed dynamic implants could partly compensate for the effects of virtual lumbar segment degeneration. The optimised operative plan was exported to two different image-guidance systems for transfer to a physical spine model. Three-dimensional computer graphic simulation is a feasible means to develop operative plans for dynamic spinal stabilization. These operative plans can be transferred to commercially available image-guidance systems for use in implantation of physical implants in a spine model. This concept has important potential in the design of operative plans and implants for individualised dynamic spine stabilization surgery.

  12. FPGA Implementation of Discrete-Time Neuronal Network for Dynamic Image Segmentation

    NASA Astrophysics Data System (ADS)

    Fujimoto, Ken'ichi; Musashi, Mio; Yoshinaga, Tetsuya

    We have developed a discrete-time dynamical system for dynamic image segmentation. It consists of a global inhibitor and modified chaotic neurons that can generate oscillatory responses. Dynamic image segmentation is performed using its oscillatory responses. This letter presents an implementation of our system in a field programmable gate array (FPGA) device and a successful result of dynamic image segmentation.

  13. Multimodality Imaging Characteristics of the Common Renal Cell Carcinoma Subtypes: An Analysis of 544 Pathologically Proven Tumors

    PubMed Central

    Fu, Winnie; Huang, Guan; Moloo, Zaahir; Girgis, Safwat; Patel, Vimal H; Low, Gavin

    2016-01-01

    Objectives: The objective of this study was to define the characteristic imaging appearances of the common renal cell carcinoma (RCC) subtypes. Materials and Methods: The Institutional Review Board approval was obtained for this HIPAA-compliant retrospective study, and informed consent was waived. 520 patients (336 men, 184 women; age range, 22–88 years) underwent preoperative cross-sectional imaging of 544 RCCs from 2008 to 2013. The imaging appearances of the RCCs and clinical information were reviewed. Data analysis was performed using parametric and nonparametric statistics, descriptive statistics, and receiver operating characteristic analysis. Results: The RCC subtypes showed significant differences (P < 0.001) in several imaging parameters such as tumor margins, tumor consistency, tumor homogeneity, the presence of a central stellate scar, T2 signal intensity, and the degree of tumor enhancement. Low T2 signal intensity on magnetic resonance imaging (MRI) allowed differentiation of papillary RCC from clear cell and chromophobe RCCs with 90.9% sensitivity and 93.1% specificity. A tumor-to-cortex ratio ≥1 on the corticomedullary phase had 98% specificity for clear cell RCC. Conclusion: The T2 signal intensity of the tumor on MRI and its degree of enhancement are useful imaging parameters for discriminating between the RCC subtypes while gross morphological findings offer additional value in RCC profiling. PMID:28123840

  14. Accuracy of radionuclide imaging in distinguishing renal masses from normal variants

    SciTech Connect

    Older, R.A.; Korobkin, M.; Workman, J.; Cleeve, D.M.; Cleeve, L.K.; Sullivan, D.; Webster, G.D.

    1980-08-01

    To determine the accuracy of scintigraphy in distinguishing true renal masses from normal variants, 40 patients with excretory urographic findings indicating a possible, but not definite, mass lesion were studied. Scintigraphy correctly identified 17 true masses and 17 normal variants. Four false positive and two false negative results were obtained.

  15. Real-Time, Holographic, Dynamic Image-Storage Device

    NASA Technical Reports Server (NTRS)

    Montgomery, Raymond C.; Lafleur, Sharon S.

    1995-01-01

    Solid-state device developed for high-speed acquisition, dynamic storage, and amplification of three-dimensional holographic images. Holograms generated via four-wave mixing in two or more photorefractive crystals (or subelements of single crystal) to create single-crystal or multicrystal oscillator. Apparatus provides dynamic storage of holographic image of object after electronic shutter closed to turn off object beam. Provides capability to store, amplify, process, and transmit time-varying, two-dimensional, spatial information. Developments include sensors, actuators, and optical computers operating at speeds on order of speed of light. Potential in applications in which need for high-speed acquisition and storage of three-dimensional holographic images.

  16. Real-Time, Holographic, Dynamic Image-Storage Device

    NASA Technical Reports Server (NTRS)

    Montgomery, Raymond C.; Lafleur, Sharon S.

    1995-01-01

    Solid-state device developed for high-speed acquisition, dynamic storage, and amplification of three-dimensional holographic images. Holograms generated via four-wave mixing in two or more photorefractive crystals (or subelements of single crystal) to create single-crystal or multicrystal oscillator. Apparatus provides dynamic storage of holographic image of object after electronic shutter closed to turn off object beam. Provides capability to store, amplify, process, and transmit time-varying, two-dimensional, spatial information. Developments include sensors, actuators, and optical computers operating at speeds on order of speed of light. Potential in applications in which need for high-speed acquisition and storage of three-dimensional holographic images.

  17. Tumor Necrosis on Magnetic Resonance Imaging Correlates with Aggressive Histology and Disease Progression in Clear Cell Renal Cell Carcinoma

    PubMed Central

    Beddy, Peter; Genega, Elizabeth M; Ngo, Long; Hindman, Nicole; Wei, Jesse; Bullock, Andrea; Bhatt, Rupal S; Atkins, Michael B; Pedrosa, Ivan

    2015-01-01

    Purpose To correlate the magnetic resonance imaging (MRI) features of clear cell renal cell carcinoma (ccRCC) with the histopathological features and disease progression. Material and Methods IRB approval for this retrospective study was obtained; patient consent was not required. The initial staging MRIs of 75 patients with histologically confirmed ccRCC were retrospectively reviewed. The imaging was assessed by two radiologists for the presence of tumor necrosis, cystic degeneration, intracellular fat, hemorrhage, retroperitoneal collaterals and renal vein thrombosis. Quantitative analysis for the MRI presence of intracellular lipid within tumors was performed. MRI findings were correlated with histopathologic findings of clear cell percentage, alveolar and tubular growth pattern and disease progression. Statistical associations were evaluated with non-parametric univariable analyses and multivariable logistic regression models. Results Correlation between MRI and histopathologic features was performed in 75 patients whereas follow-up data was available for progression analysis in 68 patients. The presence of tumor necrosis, retroperitoneal collaterals and renal vein thrombosis on MRI were significantly associated with low percentage of tumor cells with clear cytoplasm (p<0.01) and with metastatic disease at presentation or disease progression (p<0.01). At multivariable analysis, necrosis remained as the only feature statistically associated with disease progression (p=0.03, adjusted odds ratio=27.7, CI 95%=1.4–554.7 for reader one and p=0.02, adjusted odds ratio=29.3, CI 95%=1.7–520.8 for reader two). Conclusion Necrosis in ccRCC on MRI correlates with the histopathological finding of lower percentage of tumor cells with clear cytoplasm and is a poor prognostic indicator irrespective of tumor size. PMID:24145001

  18. Imaging Anisotropic Nanoplasma Dynamics in Superfluid Helium Droplets

    NASA Astrophysics Data System (ADS)

    Bacellar, Camila; Chatterley, Adam; Lackner, Florian; Pemmaraju, Sri; Tanyag, Rico; Bernando, Charles; Verma, Deepak; O'Connell, Sean; Osipiv, Timur; Ray, Dipanwita; Ferguson, Kenneth; Gorkhover, Tais; Swiggers, Michele; Bucher, Maximilian; Vilesov, Andrey; Bostedt, Christoph; Gessner, Oliver

    2016-05-01

    The dynamics of strong-field induced nanoplasmas inside superfluid helium droplets are studied using single-shot, single-particle femtosecond time-resolved X-ray coherent diffractive imaging (CDI) at the Linac Coherent Light Source (LCLS). Intense (~ 1015 W/ cm2, ~ 50 fs) 800 nm laser pulses are employed to initiate nanoplasma formation in sub-micron (200 nm - 600 nm) sized helium droplets. The dynamics of the nanoplasma formation and subsequent droplet evolution are probed by x-rays pulses (~ 100 fs, 600 eV) that are delayed with respect to the near-infrared (NIR) pulses by 10's of femtoseconds to hundreds of picoseconds. Pump-probe time-delay dependent effects in the CDI patterns reveal distinct dynamics evolving on multiple timescales. Very fast (<100 fs) appearing features are possibly indicative of electronic dynamics, while slower (>= 1 ps) dynamics are likely associated with structural changes correlated to nuclear motion including droplet disintegration. In particular, the CDI images exhibit strong indications for anisotropic dynamics governed by the NIR polarization axis, providing previously inaccessible insight into the mechanisms of nanoplasma formation and evolution.

  19. Color Doppler dynamic tissue perfusion measurement: a novel tool in the assessment of renal parenchymal perfusion in children with vesicoureteral reflux

    PubMed Central

    Scholbach, Thomas M.; Scholbach, Jakob; Pawelec, Agata; Nachulewicz, Paweł; Wieczorek, Andrzej P.; Brodzisz, Agnieszka; Zajączkowska, Maria M.; Borzęcka, Halina

    2015-01-01

    Introduction Vesicoureteral reflux (VUR) occurs in 20–50% of children suffering from recurrent urinary tract infections (UTIs) and is associated with an increased risk of renal scarring and impaired renal function. Early detection of renal perfusion deterioration would allow for the implementation of more aggressive treatment and potentially prevent further damage to the renal parenchyma. The aim of the study was to assess renal parenchymal perfusions in children with recurrent UTIs with and without coexisting VUR, and compare the findings with the results of healthy patients. Material and methods Color Doppler sonographic dynamic renal parenchymal perfusion measurements were performed with PixelFlux (Chameleon-Software, Germany) software in 77 children with recurrent UTIs and coexisting VUR and in 30 children with UTIs without VUR. The findings were compared with the results of 53 healthy children. Results Cortical parenchymal perfusion of children suffering from UTIs and VUR was significantly reduced when compared to the control group. Statistically significant differences (p < 0.05) were found in all perfusion parameters (i.e. mean velocity (vmix), mean perfused area (Amix), mean perfusion intensity (Imix), tissue pulsatility index (TPI), and tissue resistance index (TRI)) between the control group and children suffering from UTIs and VUR, particularly VUR grades III and IV. There were no significant differences between the UTI group and the control group. No differences were found between the controls and VUR grade II. Conclusions Renal parenchymal perfusion decreases significantly with higher grades of VUR. PMID:27279857

  20. Dynamic magnetic resonance imaging of the pharynx during deglutition.

    PubMed

    Amin, Milan R; Achlatis, Stratos; Lazarus, Cathy L; Branski, Ryan C; Storey, Pippa; Praminik, Bidyut; Fang, Yixin; Sodickson, Daniel K

    2013-03-01

    We utilized dynamic magnetic resonance imaging to visualize the pharynx and upper esophageal segment in normal, healthy subjects. A 3-T scanner with a 4-channel head coil and a dual-channel neck coil was used to obtain high-speed magnetic resonance images of subjects who were swallowing liquids and pudding. Ninety sequential images were acquired with a temporal resolution of 113 ms. Imaging was performed in axial planes at the levels of the oropharynx and the pharyngoesophageal segment. The images were then analyzed for variables related to alterations in the area of the pharynx and pharyngoesophageal segment during swallowing, as well as temporal measures related to these structures. All subjects tolerated the study protocol without complaint. Changes in the area of the pharyngeal wall lumen and temporal measurements were consistent within and between subjects. The inter-rater and intra-rater reliabilities for the measurement tool were excellent. Dynamic magnetic resonance imaging of the swallow sequence is both feasible and reliable and may eventually complement currently used diagnostic methods, as it adds substantive information.

  1. Dynamic Raman imaging system with high spatial and temporal resolution

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Dai, Yinzhen; He, Hao; Lv, Ruiqi; Zong, Cheng; Ren, Bin

    2017-09-01

    There is an increasing need to study dynamic changing systems with significantly high spatial and temporal resolutions. In this work, we integrated point-scanning, line-scanning, and wide-field Raman imaging techniques into a single system. By using an Electron Multiplying CCD (EMCCD) with a high gain and high frame rate, we significantly reduced the time required for wide-field imaging, making it possible to monitor the electrochemical reactions in situ. The highest frame rate of EMCDD was ˜50 fps, and the Raman images for a specific Raman peak can be obtained by passing the signal from the sample through the Liquid Crystal Tunable Filter. The spatial resolutions of scanning imaging and wide-field imaging with a 100× objective (NA = 0.9) are 0.5 × 0.5 μm2 and 0.36 × 0.36 μm2, respectively. The system was used to study the surface plasmon resonance of Au nanorods, the surface-enhanced Raman scattering signal distribution for Au Nanoparticle aggregates, and dynamic Raman imaging of an electrochemical reacting system.

  2. SIMA: Python software for analysis of dynamic fluorescence imaging data.

    PubMed

    Kaifosh, Patrick; Zaremba, Jeffrey D; Danielson, Nathan B; Losonczy, Attila

    2014-01-01

    Fluorescence imaging is a powerful method for monitoring dynamic signals in the nervous system. However, analysis of dynamic fluorescence imaging data remains burdensome, in part due to the shortage of available software tools. To address this need, we have developed SIMA, an open source Python package that facilitates common analysis tasks related to fluorescence imaging. Functionality of this package includes correction of motion artifacts occurring during in vivo imaging with laser-scanning microscopy, segmentation of imaged fields into regions of interest (ROIs), and extraction of signals from the segmented ROIs. We have also developed a graphical user interface (GUI) for manual editing of the automatically segmented ROIs and automated registration of ROIs across multiple imaging datasets. This software has been designed with flexibility in mind to allow for future extension with different analysis methods and potential integration with other packages. Software, documentation, and source code for the SIMA package and ROI Buddy GUI are freely available at http://www.losonczylab.org/sima/.

  3. Dynamic support region-based astronomical image deconvolution algorithm

    NASA Astrophysics Data System (ADS)

    Geng, Ze-xun; Chen, Bo; Xu, Qing; Zhang, Bao-ming; Gong, Zhi-hui

    2008-07-01

    The performance of high-resolution imaging with large optical instruments is severely limited by atmospheric turbulence, and an image deconvolution is required for reaching the diffraction limit. A new astronomical image deconvolution algorithm is proposed, which incorporates dynamic support region and improved cost function to NAS-RIF algorithm. The enhanced NAS-RIF (ENAS-RIF) method takes into account the noise in the image and can dynamically shrink support region (SR) in application. In restoration process, initial SR is set to approximate counter of the true object, and then SR automatically contracts with iteration going. The approximate counter of interested object is detected by means of beamlet transform detecting edge. The ENAS-RIF algorithm is applied to the restorations of in-door Laser point source and long exposure extended object images. The experimental results demonstrate that the ENAS-RIF algorithm works better than classical NAS-RIF algorithm in deconvolution of the degraded image with low SNR and convergence speed is faster.

  4. Automatic dynamic range adjustment for ultrasound B-mode imaging.

    PubMed

    Lee, Yeonhwa; Kang, Jinbum; Yoo, Yangmo

    2015-02-01

    In medical ultrasound imaging, dynamic range (DR) is defined as the difference between the maximum and minimum values of the displayed signal to display and it is one of the most essential parameters that determine its image quality. Typically, DR is given with a fixed value and adjusted manually by operators, which leads to low clinical productivity and high user dependency. Furthermore, in 3D ultrasound imaging, DR values are unable to be adjusted during 3D data acquisition. A histogram matching method, which equalizes the histogram of an input image based on that from a reference image, can be applied to determine the DR value. However, it could be lead to an over contrasted image. In this paper, a new Automatic Dynamic Range Adjustment (ADRA) method is presented that adaptively adjusts the DR value by manipulating input images similar to a reference image. The proposed ADRA method uses the distance ratio between the log average and each extreme value of a reference image. To evaluate the performance of the ADRA method, the similarity between the reference and input images was measured by computing a correlation coefficient (CC). In in vivo experiments, the CC values were increased by applying the ADRA method from 0.6872 to 0.9870 and from 0.9274 to 0.9939 for kidney and liver data, respectively, compared to the fixed DR case. In addition, the proposed ADRA method showed to outperform the histogram matching method with in vivo liver and kidney data. When using 3D abdominal data with 70 frames, while the CC value from the ADRA method is slightly increased (i.e., 0.6%), the proposed method showed improved image quality in the c-plane compared to its fixed counterpart, which suffered from a shadow artifact. These results indicate that the proposed method can enhance image quality in 2D and 3D ultrasound B-mode imaging by improving the similarity between the reference and input images while eliminating unnecessary manual interaction by the user.

  5. [64Cu]XYIMSR-06: A dual-motif CAIX ligand for PET imaging of clear cell renal cell carcinoma

    PubMed Central

    Minn, Il; Koo, Soo Min; Lee, Hye Soo; Brummet, Mary; Rowe, Steven P.; Gorin, Michael A.; Sysa-Shah, Polina; Lewis, William D.; Ahn, Hye-Hyun; Wang, Yuchuan; Banerjee, Sangeeta Ray; Mease, Ronnie C.; Nimmagadda, Sridhar; Allaf, Mohamad E.; Pomper, Martin G.; Yang, Xing

    2016-01-01

    Carbonic anhydrase IX (CAIX) is a cell surface enzyme that is over-expressed in approximately 95% of cases of clear cell renal cell carcinoma (ccRCC), the most common renal cancer. We synthesized and performed in vitro and in vivo evaluation of a dual-motif ligand, [64Cu]XYIMSR-06, for imaging CAIX expression on ccRCC tumors using positron emission tomography (PET). [64Cu]XYIMSR-06 was generated in yields of 51.0 ± 4.5% (n=5) and specific activities of 4.1 – 8.9 GBq/μmol (110-240 Ci/mmol). Tumor was visualized on PET images by 1 h post-injection with high tumor-to-background levels (>100 tumor-to-blood and -muscle) achieved within 24 h. Biodistribution studies demonstrated a maximum tumor uptake of 19.3% injected dose per gram of radioactivity at 4 h. Tumor-to-blood, -muscle and -kidney ratios were 129.6 ± 18.8, 84.3 ± 21.0 and 2.1 ± 0.3, respectively, at 8 h post-injection. At 24 h a tumor-to-kidney ratio of 7.1 ± 2.5 was achieved. These results indicate pharmacokinetics superior to those of previously reported imaging agents binding to CAIX. [64Cu]XYIMSR-06 is a new low-molecular-weight PET ligand targeting CAIX, which can image localized and metastatic ccRCC. PMID:27437764

  6. Integrated dynamic fluidic lens system for in vivo biological imaging.

    PubMed

    Justis, N B; Zhang, D-Y; Lo, Y H

    2004-01-01

    We have developed an integrated dynamic lens system for in vivo optical imaging. Bioinspired dynamic microfluidic lenses allow for real-time dynamic manipulation of the lens focal length via microfluidic injection into a PDMS membrane-capped chamber. A piezoelectrically actuated micropump is integrated with with the lens to provide highspeed, accurate lens tunability. The 5mm dynamic lens has demonstrated focal length tunability from 8.5mm to 23mm, numerical aperture values from 0.39 to 0.77, and resolution of 40 linepairs/mm. The micropump operates at 5 kHz and achieved a flow rate of approximately 2.4 mL/min. This system can be applied to optical probe techniques to improve diagnosis with real-time depth resolution and variable numerical aperture.

  7. Diagnosis of ureteral obstruction in patients with compromised renal function: the role of noninvasive imaging modalities.

    PubMed

    Shokeir, Ahmed A; El-Diasty, Tarek; Eassa, Waleed; Mosbah, Ahmed; El-Ghar, Mohamed Abou; Mansour, Osama; Dawaba, Mohamed; El-Kappany, Hamdy

    2004-06-01

    We compared the role of noncontrast computerized tomography (NCCT), magnetic resonance urography (MRU), and combined abdominal radiography (KUB) and ultrasonography (US) in the diagnosis of the cause of ureteral obstruction in patients with compromised renal function. The study included 149 patients, of whom 110 had bilateral obstruction and 39 had obstruction of a solitary kidney. Therefore, the total number of renal units was 259. All patients had renal impairment with serum creatinine greater than 2.5 mg/dl. Besides conventional KUB and US all patients underwent NCCT and MRU. The gold standard for diagnosis of the cause of obstruction included retrograde or antegrade ureterogram, ureteroscopy and/or open surgery. The sensitivity, specificity and overall accuracy of NCCT, MRU, and combined KUB and US in the diagnosis of ureteral obstruction were calculated in comparison with the gold standard. The definitive cause of ureteral obstruction was calculous in 146 and noncalculous in 113 renal units, including ureteral stricture in 65, bladder or ureter in 43, extraurinary collection in 3 and retroperitoneal fibrosis in 2. The site of stone impaction was identified by NCCT in all 146 renal units (100% sensitivity), by MRU in 101 (69.2% sensitivity), and by combined KUB and US in 115 (78.7% sensitivity) with a difference of significant value in favor of NCCT (p <0.001). Ureteral strictures were identified by NCCT in 18 of the 65 cases (28%) and by MRU in 54 of 65 (83%). Bladder and ureteral tumors causing ureteral obstruction could be diagnosed in approximately half of the patients by NCCT (22 of 43) and in all except 1 by MRU (42 of 43). NCCT and MRU could identify all extraurinary causes of obstruction. Overall of the 113 kidneys with noncalculous obstruction the cause could be identified by MRU in 101 (89% sensitivity), by NCCT in 45 (40% sensitivity), and by combined KUB and US in only 20 (18% sensitivity) with a difference of significant value in favor of MRU (p <0

  8. Adaptive fusion of infrared and visible images in dynamic scene

    NASA Astrophysics Data System (ADS)

    Yang, Guang; Yin, Yafeng; Man, Hong; Desai, Sachi

    2011-11-01

    Multiple modalities sensor fusion has been widely employed in various surveillance and military applications. A variety of image fusion techniques including PCA, wavelet, curvelet and HSV has been proposed in recent years to improve human visual perception for object detection. One of the main challenges for visible and infrared image fusion is to automatically determine an optimal fusion strategy for different input scenes along with an acceptable computational cost. This paper, we propose a fast and adaptive feature selection based image fusion method to obtain high a contrast image from visible and infrared sensors for targets detection. At first, fuzzy c-means clustering is applied on the infrared image to highlight possible hotspot regions, which will be considered as potential targets' locations. After that, the region surrounding the target area is segmented as the background regions. Then image fusion is locally applied on the selected target and background regions by computing different linear combination of color components from registered visible and infrared images. After obtaining different fused images, histogram distributions are computed on these local fusion images as the fusion feature set. The variance ratio which is based on Linear Discriminative Analysis (LDA) measure is employed to sort the feature set and the most discriminative one is selected for the whole image fusion. As the feature selection is performed over time, the process will dynamically determine the most suitable feature for the image fusion in different scenes. Experiment is conducted on the OSU Color-Thermal database, and TNO Human Factor dataset. The fusion results indicate that our proposed method achieved a competitive performance compared with other fusion algorithms at a relatively low computational cost.

  9. Training and Maintaining: Developing a Successful and Dynamic Continuous Renal Replacement Therapy Program.

    PubMed

    Przybyl, Heather; Evans, Jill; Haley, Laurie; Bisek, Jodi; Beck, Emily

    2017-01-01

    Continuous renal replacement therapy (CRRT) is commonly used to support critically ill patients with acute kidney injury or chronic renal disease whose condition is too unstable for them to tolerate intermittent hemodialysis. Current publications related to CRRT programs in the United States and Canada note key themes related to the development and maintenance of CRRT training programs. A successful CRRT training program should consider and incorporate adult learning principles whenever possible. A variety of teaching methods to deliver information to nurses, including online learning modules, didactic lecture, return demonstration, and high-fidelity patient simulation are key to training programs for this high-risk complex therapy. This article outlines the approach to training nurses to care for patients receiving CRRT at a health care system in Arizona.

  10. Kalman filter techniques for accelerated Cartesian dynamic cardiac imaging.

    PubMed

    Feng, Xue; Salerno, Michael; Kramer, Christopher M; Meyer, Craig H

    2013-05-01

    In dynamic MRI, spatial and temporal parallel imaging can be exploited to reduce scan time. Real-time reconstruction enables immediate visualization during the scan. Commonly used view-sharing techniques suffer from limited temporal resolution, and many of the more advanced reconstruction methods are either retrospective, time-consuming, or both. A Kalman filter model capable of real-time reconstruction can be used to increase the spatial and temporal resolution in dynamic MRI reconstruction. The original study describing the use of the Kalman filter in dynamic MRI was limited to non-Cartesian trajectories because of a limitation intrinsic to the dynamic model used in that study. Here the limitation is overcome, and the model is applied to the more commonly used Cartesian trajectory with fast reconstruction. Furthermore, a combination of the Kalman filter model with Cartesian parallel imaging is presented to further increase the spatial and temporal resolution and signal-to-noise ratio. Simulations and experiments were conducted to demonstrate that the Kalman filter model can increase the temporal resolution of the image series compared with view-sharing techniques and decrease the spatial aliasing compared with TGRAPPA. The method requires relatively little computation, and thus is suitable for real-time reconstruction.

  11. From in vitro to in vivo by dynamic multiwavelength imaging

    NASA Astrophysics Data System (ADS)

    Farkas, Daniel L.; Ballou, Byron T.; Fisher, Gregory W.; Taylor, D. Lansing

    1995-04-01

    There is a clear trend today towards non-invasive, dynamic, digital approaches to biomedical imaging, and a need for even higher resolution. Light is particularly well suited for such investigations, as its temporal, spatial and intensity range are unparalleled. A convergence of new capabilities from fields as diverse as electronics, optics, molecular biology, computer science and dye chemistry have transformed light microscopy from a traditional, static, 2D tool into a highly useful, dynamic, 3D research capability for biology and medicine. We believe that the understanding of certain fundamental biological functions by dynamic mapping of events in living systems is within reach, based on novel, interdisciplinary methods. For imaging molecular events with high resolution (live cells, in vitro), light microscopy has continued to improve in performance, and we survey here some of our recent progress. The same dynamic mapping can be extended to organs, whole animals and humans, by monitoring molecules labeled with the long-wavelength dyes that proved useful in microscopy. We report here results obtained by in vivo imaging of fluorescently labeled monoclonal antibodies, indicative of tumor location and evolution in nude mice.

  12. Imaging and Modeling the Dynamics of Clathrin-Mediated Endocytosis

    PubMed Central

    Mettlen, Marcel

    2014-01-01

    Clathrin-mediated endocytosis (CME) plays a central role in cellular homeostasis and is mediated by clathrin-coated pits (CCPs). Live-cell imaging has revealed a remarkable heterogeneity in CCP assembly kinetics, which can be used as an intrinsic source of mechanistic information on CCP regulation but also poses several major problems for unbiased analysis of CME dynamics. The backbone of unveiling the molecular control of CME is an imaging-based inventory of the full diversity of individual CCP behaviors, which requires detection and tracking of structural fiduciaries and regulatory proteins with an accuracy of >99.9%, despite very low signals. This level of confidence can only be achieved by combining appropriate imaging modalities with self-diagnostic computational algorithms for image analysis and data mining. PMID:25167858

  13. A Review of Digital Image Correlation Applied to Structura Dynamics

    NASA Astrophysics Data System (ADS)

    Niezrecki, Christopher; Avitabile, Peter; Warren, Christopher; Pingle, Pawan; Helfrick, Mark

    2010-05-01

    A significant amount of interest exists in performing non-contacting, full-field surface velocity measurement. For many years traditional non-contacting surface velocity measurements have been made by using scanning Doppler laser vibrometry, shearography, pulsed laser interferometry, pulsed holography, or an electronic speckle pattern interferometer (ESPI). Three dimensional (3D) digital image correlation (DIC) methods utilize the alignment of a stereo pair of images to obtain full-field geometry data, in three dimensions. Information about the change in geometry of an object over time can be found by comparing a sequence of images and virtual strain gages (or position sensors) can be created over the entire visible surface of the object of interest. Digital imaging techniques were first developed in the 1980s but the technology has only recently been exploited in industry and research due to the advances of digital cameras and personal computers. The use of DIC for structural dynamic measurement has only very recently been investigated. Within this paper, the advantages and limits of using DIC for dynamic measurement are reviewed. Several examples of using DIC for dynamic measurement are presented on several vibrating and rotating structures.

  14. Dynamic mask: new approach to laser engraving of halftone images

    NASA Astrophysics Data System (ADS)

    Kadan, Victor N.; Pekarik, Alexander S.; Estrela Liopis, Rafael V.

    1997-03-01

    New approach to laser engraving of half tone images has been proposed and tested. Combining two basic approaches to laser engraving -- single pulse mask imaging and raster element construction by pack of laser pulses -- the new system constructs every individual raster element by imaging on the workpiece surface a dynamic mask of controlled size. The dynamic mask shape corresponds to the required raster element shape. This approach offers several important advantages over the conventional ones: (1) analog control of the mask shape provides gray level continuum, thus ensuring the image quality, unattainable by other means; (2) raster element marking by single laser pulse provides very good marking rate. It takes only one scan of the writing laser head to mark raster line. Much more powerful laser pulses can be used to engrave complete raster element by single pulse instead of its point-by-point construction by consecutive laser pulses; (3) the influence of laser beam quality parameters, such as beam divergence, and power instabilities on the gray level has been greatly reduced because raster element shape primarily depends on the mask shape and not on the power level and beam divergence. Dynamic mask system can be used both with cw and pulsed laser. Gray scale tones can be reproduced by the linear raster line width in the first case. Advantages of the new device have been demonstrated by engravings on stone, wood, etc. made with 50 W carbon-dioxide laser.

  15. Dynamic epigenetic changes to VHL occur with sunitinib in metastatic clear cell renal cancer

    PubMed Central

    Stewart, Grant D.; Powles, Thomas; Van Neste, Christophe; Meynert, Alison; O'Mahony, Fiach; Laird, Alexander; Deforce, Dieter; Van Nieuwerburgh, Filip; Trooskens, Geert; Van Criekinge, Wim; De Meyer, Tim; Harrison, David J.

    2016-01-01

    Background Genetic intratumoral heterogeneity (ITH) hinders biomarker development in metastatic clear cell renal cancer (mccRCC). Epigenetic relative to genetic ITH or the presence of consistent epigenetic changes following targeted therapy in mccRCC have not been evaluated. The aim of this study was to determine methylome/genetic ITH and to evaluate specific epigenetic and genetic changes associated with sunitinib therapy. Patients and methods Multi-region DNA sampling performed on sequential frozen pairs of primary tumor tissue from 14 metastatic ccRCC patients, in the Upfront Sunitinib (SU011248) Therapy Followed by Surgery in Patients with Metastatic Renal Cancer: a Pilot Phase II Study (SuMR; ClinicalTrials.gov identifier: NCT01024205), at presentation (biopsy) and after 3-cycles of 50mg sunitinib (nephrectomy). Untreated biopsy and nephrectomy samples before and after renal artery ligation were controls. Ion Proton sequencing of 48 key ccRCC genes, and MethylCap-seq DNA methylation analysis was performed, data was analysed using the statistical computing environment R. Results Unsupervised hierarchical clustering revealed complete methylome clustering of biopsy and three nephrectomy samples for each patient (14/14 patients). For mutational status, untreated biopsy and all treated nephrectomy samples clustered together in 8/13 (61.5%) patients. The only methylation target significantly altered following sunitinib therapy was VHL promoter region 7896829 which was hypermethylated with treatment (FDR=0.077, P<0.001) and consistent for all patients (pre-treatment 50% patients had VHL mutations, 14% patients VHL hypermethylation). Renal artery ligation did not affect this result. No significant differences in driver or private mutation count was found with sunitinib treatment. Conclusions Demonstration of relative methylome homogeneity and consistent VHL hypermethylation, after sunitinib, may overcome the hurdle of ITH present at other molecular levels for

  16. Differential uptake of Tc-99m DMSA and Tc-99m EC in renal tubular disorders: Report of two cases and review of the literature

    PubMed Central

    Reddy Gorla, Arun Kumar; Agrawal, Kanhaiyalal; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2014-01-01

    Tc-99m DMSA and Tc-99m EC studies are invaluable functional imaging modalities for renal structural and functional assessment. Normally, the relative renal function estimated by the two methods correlates well with each other. We here present two patients with renal tubular acidosis who showed impaired/altered DMSA uptake with normal EC renal dynamic study depicting the pitfall of DMSA imaging in tubular disorders. The two presented cases also depict distinct pattern of Tc-99m DMSA scintigraphic findings in patients with proximal and distal renal tubular acidosis, thus highlighting the factors affecting DMSA kinetics. PMID:25210282

  17. Differential uptake of Tc-99m DMSA and Tc-99m EC in renal tubular disorders: Report of two cases and review of the literature.

    PubMed

    Reddy Gorla, Arun Kumar; Agrawal, Kanhaiyalal; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2014-07-01

    Tc-99m DMSA and Tc-99m EC studies are invaluable functional imaging modalities for renal structural and functional assessment. Normally, the relative renal function estimated by the two methods correlates well with each other. We here present two patients with renal tubular acidosis who showed impaired/altered DMSA uptake with normal EC renal dynamic study depicting the pitfall of DMSA imaging in tubular disorders. The two presented cases also depict distinct pattern of Tc-99m DMSA scintigraphic findings in patients with proximal and distal renal tubular acidosis, thus highlighting the factors affecting DMSA kinetics.

  18. Renal Medullary and Cortical Correlates in Fibrosis, Epithelial Mass, Microvascularity, and Microanatomy Using Whole Slide Image Analysis Morphometry

    PubMed Central

    Farris, Alton B.; Ellis, Carla L.; Rogers, Thomas E.; Lawson, Diane; Cohen, Cynthia; Rosen, Seymour

    2016-01-01

    Renal tubulointerstitial injury often leads to interstitial fibrosis and tubular atrophy (IF/TA). IF/TA is typically assessed in the renal cortex and can be objectively quantitated with computerized image analysis (IA). However, the human medulla accounts for a substantial proportion of the nephron; therefore, medullary scarring will have important cortical consequences and may parallel overall chronic renal injury. Trichrome, periodic acid–Schiff (PAS), and collagen III immunohistochemistry (IHC) were visually examined and quantitated on scanned whole slide images (WSIs) (N = 67 cases). When tuned to measure fibrosis, IA of trichrome and Trichrome-PAS (T-P) WSIs correlated for all anatomic compartments (among cortex, medulla, and entire tissue, r = 0.84 to 0.89, P all <0.0001); and collagen III deposition correlated between compartments (r = 0.69 to 0.89, P <0.0001 to 0.0002); however, trichrome and T-P measures did not correlate with collagen deposition, suggesting heterogeneous contributions to extracellular matrix deposition. Epithelial cell mass (EPCM) correlated between cortex and medulla when measured with cytokeratin IHC and with the trichrome red portion (r = 0.85 and 0.66, respectively, all P < 0.0001). Visual assessment also correlated between compartments for fibrosis and EPCM. Correlations were found between increasing medullary inner stripe (IS) width and fibrosis in all of the tissue and the medulla by trichrome morphometry (r = 0.56, P < 0.0001, and r = 0.48, P = 0.00008, respectively). Weak correlations were found between increasing IS width and decreasing visual assessment of all tissue EPCM. Microvessel density (MVD) and microvessel area (MVA) measured using a MVD algorithm applied to CD34 IHC correlated significantly between all compartments (r = 0.76 to 0.87 for MVD and 0.71 to 0.87 for MVA, P all < 0.0001). Overall, these findings demonstrate the interrelatedness of the cortex and medulla and the importance of considering the renal

  19. Renal artery aneurysms.

    PubMed

    González, J; Esteban, M; Andrés, G; Linares, E; Martínez-Salamanca, J I

    2014-01-01

    A renal artery aneurysm is defined as a dilated segment of renal artery that exceeds twice the diameter of a normal renal artery. Although rare, the diagnosis and incidence of this entity have been steadily increasing due to the routine use of cross-sectional imaging. In certain cases, renal artery aneurysms may be clinically important and potentially lethal. However, knowledge of their occurrence, their natural history, and their prognosis with or without treatment is still limited. This article aims to review the recent literature concerning renal artery aneurysms, with special consideration given to physiopathology, indications for treatment, different technical options, post-procedure complications and treatment outcomes.

  20. Systemic disorders of calcium dynamics in rats with adenine-induced renal failure: implication for chronic kidney disease-related complications.

    PubMed

    Ikeda, Ryuji; Imai, Yasuo; Maruyama, Wakako; Mizoguchi, Kazushige

    2010-02-01

    Chronic kidney disease (CKD) causes the dysregulation of systemic mineral metabolism. A major issue in CKD patients is the emergence of ectopic calcification in soft tissues, presumably due to increased levels of calcium (Ca) or inorganic phosphorus (Pi); however, the precise mechanisms have not been fully elucidated. Therefore, this study aims to evaluate Ca dynamics in an animal model of CKD. Renal failure was produced in rats by feeding an adenine-containing diet for 4 weeks, and time-course changes in biochemical parameters, including Ca, Pi, creatinine (Cr), blood urea nitrogen (BUN), parathyroid hormone (PTH), 1,25-dihydroxyvitamin D(3), and N-telopeptide and cross-linked collagen type I (NTx), were monitored once a week during the feeding period. Intestinal absorption, tissue contents, and urinary excretion of Ca were monitored using radioisotope (RI) (45)Ca. Adenine-fed rats exhibited renal failure, ectopic calcification and altered serum parameters, including elevated levels of serum Pi, Cr, PTH and BUN. Serum Ca levels were not increased in rats with renal failure. RI-based experiments revealed that abnormal Ca dynamics including attenuated intestinal absorption, increased incorporation into soft tissues, particularly aortic tissue, in which it was increased threefold, and enhanced urinary excretion occurred in renal failure rats. Rats with renal failure induced by an adenine diet exhibited severe abnormality of Ca dynamics, including Ca shortage and ectopic accumulation of Ca. These findings would provide useful information to research CKD-related complications.

  1. Estimation of pressure gradients at renal artery stenoses

    NASA Astrophysics Data System (ADS)

    Yim, Peter J.; Cebral, Juan R.; Weaver, Ashley; Lutz, Robert J.; Vasbinder, G. Boudewijn C.

    2003-05-01

    Atherosclerotic disease of the renal artery can reduce the blood flow leading to renovascular hypertension and ischemic nephopathy. The kidney responds to a decrease in blood flow by activation of the renin-angiotensin system that increases blood pressure and can result in severe hypertension. Percutaneous translumenal angioplasty (PTA) may be indicated for treatment of renovascular hypertension (RVH). However, direct measurement of renal artery caliber and degree of stenosis has only moderate specificity for detection of RVH. A confounding factor in assessment of the proximal renal artery is that diffuse atherosclerotic disease of the distal branches of the renal artery can produce the same effect on blood-flow as atherosclerotic disease of the proximal renal artery. A methodology is proposed for estimation of pressure gradients at renal artery stenoses from magnetic resonance imaging that could improve the evaluation of renal artery disease. In the proposed methodology, pressure gradients are estimated using computational fluid dynamics (CFD) modeling. Realistic CFD models are constructed from images of vessel shape and measurements of blood-flow rates which are available from magnetic resonance angiography (MRA) and phase-contrast magnetic resonance (MR) imaging respectively. CFD measurement of renal artery pressure gradients has been validated in a physical flow-through model.

  2. High-dynamic-range pixel architectures for diagnostic medical imaging

    NASA Astrophysics Data System (ADS)

    Karim, Karim S.; Yin, Sherman; Nathan, Arokia; Rowlands, John A.

    2004-05-01

    One approach to increase pixel signal-to-noise ratio (SNR) in low noise digital fluoroscopy is to employ in-situ pixel amplification via current-mediated active pixel sensors (C-APS). Experiments reveal a reduction in readout noise and indicate that an a-Si C-APS, coupled together with an established X-ray detection technology such as amorphous selenium (a-Se), can meet the stringent requirements (of < 1000 noise electrons) for digital X-ray fluoroscopy. A challenge with the C-APS circuit is the presence of a small-signal input linearity constraint. While using such a pixel amplifier for real-time fluoroscopy (where the exposure level is small) is feasible, the voltage change at the amplifier input is much higher in chest radiography or mammography due to the larger X-ray exposure levels. The larger input voltage causes the C-APS output to be non-linear thus reducing the pixel dynamic range. In addition, the resulting larger pixel output current causes the external column amplifier to saturate further reducing the pixel dynamic range. In this research, we investigate two alternate amplified pixel architectures that exhibit higher dynamic range. The test pixels are designed and simulated using an a-Si TFT model implemented in Verilog-A and results indicate a linear performance, high dynamic range, and a programmable circuit gain via choice of supply voltage and sampling time. These high dynamic range pixel architectures have the potential to enable a large area, active matrix flat panel imager (AMFPI) to switch instantly between low exposure, fluoroscopic imaging and higher exposure radiographic imaging modes. Lastly, the high dynamic range pixel circuits are suitable for integration with on-panel multiplexers for both gate and data lines, which can further reduce circuit complexity.

  3. Dynamic Studies of Lung Fluid Clearance with Phase Contrast Imaging

    SciTech Connect

    Kitchen, Marcus J.; Williams, Ivan; Irvine, Sarah C.; Morgan, Michael J.; Paganin, David M.; Lewis, Rob A.; Pavlov, Konstantin; Hooper, Stuart B.; Wallace, Megan J.; Siu, Karen K. W.; Yagi, Naoto; Uesugi, Kentaro

    2007-01-19

    Clearance of liquid from the airways at birth is a poorly understood process, partly due to the difficulties of observing and measuring the distribution of air within the lung. Imaging dynamic processes within the lung in vivo with high contrast and spatial resolution is therefore a major challenge. However, phase contrast X-ray imaging is able to exploit inhaled air as a contrast agent, rendering the lungs of small animals visible due to the large changes in the refractive index at air/tissue interfaces. In concert with the high spatial resolution afforded by X-ray imaging systems (<100 {mu}m), propagation-based phase contrast imaging is ideal for studying lung development. To this end we have utilized intense, monochromatic synchrotron radiation, together with a fast readout CCD camera, to study fluid clearance from the lungs of rabbit pups at birth. Local rates of fluid clearance have been measured from the dynamic sequences using a single image phase retrieval algorithm.

  4. Parametric dynamic F-18-FDG PET/CT breast imaging

    NASA Astrophysics Data System (ADS)

    Magri, Alphonso; Feiglin, David; Lipson, Edward; Mandel, James; McGraw, Wendy; Lee, Wei; Krol, Andrzej

    2008-03-01

    This study was undertaken to estimate metabolic tissue properties from dynamic breast F-18-FDG PET/CT image series and to display them as 3D parametric images. Each temporal PET series was obtained immediately after injection of 10 mCi of F-18-FDG and consisted of fifty 1- minute frames. Each consecutive frame was nonrigidly registered to the first frame using a finite element method (FEM) based model and fiducial skin markers. Nonlinear curve fitting of activity vs. time based on a realistic two-compartment model was performed for each voxel of the volume. Curve fitting was accomplished by application of the Levenburg-Marquardt algorithm (LMA) that minimized X2. We evaluated which parameters are most suitable to determine the spatial extent and malignancy in suspicious lesions. In addition, Patlak modeling was applied to the data. A mixture model was constructed and provided a classification system for the breast tissue. It produced unbiased estimation of the spatial extent of the lesions. We conclude that nonrigid registration followed by voxel-by-voxel based nonlinear fitting to a realistic two-compartment model yields better quality parametric images, as compared to unprocessed dynamic breast PET time series. By comparison with the mixture model, we established that the total cumulated activity and maximum activity parametric images provide the best delineation of suspicious breast tissue lesions and hyperactive subregions within the lesion that cannot be discerned in unprocessed images.

  5. Multifractal analysis of dynamic infrared imaging of breast cancer

    NASA Astrophysics Data System (ADS)

    Gerasimova, E.; Audit, B.; Roux, S. G.; Khalil, A.; Argoul, F.; Naimark, O.; Arneodo, A.

    2013-12-01

    The wavelet transform modulus maxima (WTMM) method was used in a multifractal analysis of skin breast temperature time-series recorded using dynamic infrared (IR) thermography. Multifractal scaling was found for healthy breasts as the signature of a continuous change in the shape of the probability density function (pdf) of temperature fluctuations across time scales from \\sim0.3 to 3 s. In contrast, temperature time-series from breasts with malignant tumors showed homogeneous monofractal temperature fluctuations statistics. These results highlight dynamic IR imaging as a very valuable non-invasive technique for preliminary screening in asymptomatic women to identify those with risk of breast cancer.

  6. Statistical analysis of dynamic sequences for functional imaging

    NASA Astrophysics Data System (ADS)

    Kao, Chien-Min; Chen, Chin-Tu; Wernick, Miles N.

    2000-04-01

    Factor analysis of medical image sequences (FAMIS), in which one concerns the problem of simultaneous identification of homogeneous regions (factor images) and the characteristic temporal variations (factors) inside these regions from a temporal sequence of images by statistical analysis, is one of the major challenges in medical imaging. In this research, we contribute to this important area of research by proposing a two-step approach. First, we study the use of the noise- adjusted principal component (NAPC) analysis developed by Lee et. al. for identifying the characteristic temporal variations in dynamic scans acquired by PET and MRI. NAPC allows us to effectively reject data noise and substantially reduce data dimension based on signal-to-noise ratio consideration. Subsequently, a simple spatial analysis based on the criteria of minimum spatial overlapping and non-negativity of the factor images is applied for extraction of the factors and factor images. In our simulation study, our preliminary results indicate that the proposed approach can accurately identify the factor images. However, the factors are not completely separated.

  7. High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

    SciTech Connect

    Evtushenko, Pavel E.; Douglas, David R.

    2013-06-01

    Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 {micro}m was used for the measurements. When tested with a laser beam images with the DR of about 10{sup 5} were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.

  8. High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

    SciTech Connect

    Evtushenko, Pavel; Douglas, David R.; Legg, Robert A.; Tennant, Christopher D.

    2013-05-01

    Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 {micro}m was used for the measurements. When tested with a laser beam images with the DR of about 10{sup 5} were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.

  9. Fuzzy rule-based image segmentation in dynamic MR images of the liver

    NASA Astrophysics Data System (ADS)

    Kobashi, Syoji; Hata, Yutaka; Tokimoto, Yasuhiro; Ishikawa, Makato

    2000-06-01

    This paper presents a fuzzy rule-based region growing method for segmenting two-dimensional (2-D) and three-dimensional (3- D) magnetic resonance (MR) images. The method is an extension of the conventional region growing method. The proposed method evaluates the growing criteria by using fuzzy inference techniques. The use of the fuzzy if-then rules is appropriate for describing the knowledge of the legions on the MR images. To evaluate the performance of the proposed method, it was applied to artificially generated images. In comparison with the conventional method, the proposed method shows high robustness for noisy images. The method then applied for segmenting the dynamic MR images of the liver. The dynamic MR imaging has been used for diagnosis of hepatocellular carcinoma (HCC), portal hypertension, and so on. Segmenting the liver, portal vein (PV), and inferior vena cava (IVC) can give useful description for the diagnosis, and is a basis work of a pres-surgery planning system and a virtual endoscope. To apply the proposed method, fuzzy if-then rules are derived from the time-density curve of ROIs. In the experimental results, the 2-D reconstructed and 3-D rendered images of the segmented liver, PV, and IVC are shown. The evaluation by a physician shows that the generated images are comparable to the hepatic anatomy, and they would be useful to understanding, diagnosis, and pre-surgery planning.

  10. Compressive dynamic range imaging via Bayesian shrinkage dictionary learning

    NASA Astrophysics Data System (ADS)

    Yuan, Xin

    2016-12-01

    We apply the Bayesian shrinkage dictionary learning into compressive dynamic-range imaging. By attenuating the luminous intensity impinging upon the detector at the pixel level, we demonstrate a conceptual design of an 8-bit camera to sample high-dynamic-range scenes with a single snapshot. Coding strategies for both monochrome and color cameras are proposed. A Bayesian reconstruction algorithm is developed to learn a dictionary in situ on the sampled image, for joint reconstruction and demosaicking. We use global-local shrinkage priors to learn the dictionary and dictionary coefficients representing the data. Simulation results demonstrate the feasibility of the proposed camera and the superior performance of the Bayesian shrinkage dictionary learning algorithm.

  11. Digital optical tomography system for dynamic breast imaging

    PubMed Central

    Flexman, Molly L.; Khalil, Michael A.; Al Abdi, Rabah; Kim, Hyun K.; Fong, Christopher J.; Desperito, Elise; Hershman, Dawn L.; Barbour, Randall L.; Hielscher, Andreas H.

    2011-01-01

    Diffuse optical tomography has shown promising results as a tool for breast cancer screening and monitoring response to chemotherapy. Dynamic imaging of the transient response of the breast to an external stimulus, such as pressure or a respiratory maneuver, can provide additional information that can be used to detect tumors. We present a new digital continuous-wave optical tomography system designed to simultaneously image both breasts at fast frame rates and with a large number of sources and detectors. The system uses a master-slave digital signal processor-based detection architecture to achieve a dynamic range of 160 dB and a frame rate of 1.7 Hz with 32 sources, 64 detectors, and 4 wavelengths per breast. Included is a preliminary study of one healthy patient and two breast cancer patients showing the ability to identify an invasive carcinoma based on the hemodynamic response to a breath hold. PMID:21806275

  12. Digital optical tomography system for dynamic breast imaging.

    PubMed

    Flexman, Molly L; Khalil, Michael A; Al Abdi, Rabah; Kim, Hyun K; Fong, Christopher J; Desperito, Elise; Hershman, Dawn L; Barbour, Randall L; Hielscher, Andreas H

    2011-07-01

    Diffuse optical tomography has shown promising results as a tool for breast cancer screening and monitoring response to chemotherapy. Dynamic imaging of the transient response of the breast to an external stimulus, such as pressure or a respiratory maneuver, can provide additional information that can be used to detect tumors. We present a new digital continuous-wave optical tomography system designed to simultaneously image both breasts at fast frame rates and with a large number of sources and detectors. The system uses a master-slave digital signal processor-based detection architecture to achieve a dynamic range of 160 dB and a frame rate of 1.7 Hz with 32 sources, 64 detectors, and 4 wavelengths per breast. Included is a preliminary study of one healthy patient and two breast cancer patients showing the ability to identify an invasive carcinoma based on the hemodynamic response to a breath hold.

  13. Imaging of Myocardial Fibrosis in Patients with End-Stage Renal Disease: Current Limitations and Future Possibilities

    PubMed Central

    Patel, A. S.; Marsh, A.-M.; McAdam, J.; McCann, G. P.; Burton, J. O.

    2017-01-01

    Cardiovascular disease in patients with end-stage renal disease (ESRD) is driven by a different set of processes than in the general population. These processes lead to pathological changes in cardiac structure and function that include the development of left ventricular hypertrophy and left ventricular dilatation and the development of myocardial fibrosis. Reduction in left ventricular hypertrophy has been the established goal of many interventional trials in patients with chronic kidney disease, but a recent systematic review has questioned whether reduction of left ventricular hypertrophy improves cardiovascular mortality as previously thought. The development of novel imaging biomarkers that link to cardiovascular outcomes and that are specific to the disease processes in ESRD is therefore required. Postmortem studies of patients with ESRD on hemodialysis have shown that the extent of myocardial fibrosis is strongly linked to cardiovascular death and accurate imaging of myocardial fibrosis would be an attractive target as an imaging biomarker. In this article we will discuss the current imaging methods available to measure myocardial fibrosis in patients with ESRD, the reliability of the techniques, specific challenges and important limitations in patients with ESRD, and how to further develop the techniques we have so they are sufficiently robust for use in future clinical trials. PMID:28349062

  14. Recurrent renal giant leiomyosarcoma

    PubMed Central

    Öziş, Salih Erpulat; Gülpınar, Kamil; Şahlı, Zafer; Konak, Baha Burak; Keskin, Mete; Özdemir, Süleyman; Ataoğlu, Ömür

    2016-01-01

    Primary renal leiomyosarcomas are rare, aggressive tumors. They constitute 1–2% of adult malignant renal tumors. Although leiomyosarcomas are the most common histological type (50–60%) of renal sarcomas, information on renal leiomyosarcoma is limited. Local or systemic recurrences are common. The radiological appearance of renal leiomyosarcomas is not specific, therefore renal leiomyosarcoma cannot be distinguished from renal cell carcinoma by imaging methods in all patients. A 74-year-old female patient presented to our clinic complaining of a palpable mass on the right side of her abdomen in November 2012. The abdominal magnetic resonance imaging revealed a mass, 25 × 24 × 23 cm in size. Her past medical history revealed that she has undergone right radical nephrectomy in 2007, due to a 11 × 12 × 13 cm renal mass that was then reported as renal cell carcinoma on abdominal magnetic resonance imaging, but the pathological diagnosis was low-grade renal leiomyosarcoma. The most recent follow-up of the patient was in 2011, with no signs of local recurrence or distant metastases within this four-year period. The patient underwent laparotomy on November 2012, and a 35 cm retroperitoneal mass was excised. The pathological examination of the mass was reported as high-grade leiomyosarcoma. The formation of this giant retroperitoneal mass in 1 year can be explained by the transformation of the lesion’s pathology from low-grade to a high-grade tumor. PMID:27436926

  15. Hybrid bright-field and hologram imaging of cell dynamics

    NASA Astrophysics Data System (ADS)

    Byeon, Hyeokjun; Lee, Jaehyun; Doh, Junsang; Lee, Sang Joon

    2016-09-01

    Volumetric observation is essential for understanding the details of complex biological phenomena. In this study, a bright-field microscope, which provides information on a specific 2D plane, and a holographic microscope, which provides information spread over 3D volumes, are integrated to acquire two complementary images simultaneously. The developed system was successfully applied to capture distinct T-cell adhesion dynamics on inflamed endothelial layers, including capture, rolling, crawling, transendothelial migration, and subendothelial migration.

  16. Linear dynamic range enhancement in a CMOS imager

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor)

    2008-01-01

    A CMOS imager with increased linear dynamic range but without degradation in noise, responsivity, linearity, fixed-pattern noise, or photometric calibration comprises a linear calibrated dual gain pixel in which the gain is reduced after a pre-defined threshold level by switching in an additional capacitance. The pixel may include a novel on-pixel latch circuit that is used to switch in the additional capacitance.

  17. Hybrid bright-field and hologram imaging of cell dynamics

    PubMed Central

    Byeon, Hyeokjun; Lee, Jaehyun; Doh, Junsang; Lee, Sang Joon

    2016-01-01

    Volumetric observation is essential for understanding the details of complex biological phenomena. In this study, a bright-field microscope, which provides information on a specific 2D plane, and a holographic microscope, which provides information spread over 3D volumes, are integrated to acquire two complementary images simultaneously. The developed system was successfully applied to capture distinct T-cell adhesion dynamics on inflamed endothelial layers, including capture, rolling, crawling, transendothelial migration, and subendothelial migration. PMID:27640337

  18. ESPR uroradiology task force and ESUR Paediatric Work Group--Imaging recommendations in paediatric uroradiology, part VI: childhood renal biopsy and imaging of neonatal and infant genital tract. Minutes from the task force session at the annual ESPR Meeting 2012 in Athens on childhood renal biopsy and imaging neonatal genitalia.

    PubMed

    Riccabona, Michael; Lobo, Maria Luisa; Willi, Ulrich; Avni, Fred; Damasio, Beatrice; Ording-Mueller, Lil-Sofie; Blickman, Johan; Darge, Kassa; Papadopoulou, Frederika; Vivier, Pierre-Hugues

    2014-04-01

    The European Society of Paediatric Radiology Uroradiology Task Force and the ESUR Paediatric Work Group jointly publish guidelines for paediatric urogenital imaging. Two yet unaddressed topics involving patient safety and imaging load are addressed in this paper: renal biopsy in childhood and imaging of the neonatal genital tract, particularly in girls. Based on our thorough review of literature and variable practice in multiple centers, procedural recommendations are proposed on how to perform renal biopsy in children and how to approach the genital tract in (female) neonates. These are statements by consensus due to lack of sufficient evidence-based data. The procedural recommendation on renal biopsy in childhood aims at improving patient safety and reducing the number of unsuccessful passes and/or biopsy-related complications. The recommendation for an imaging algorithm in the assessment of the neonatal genital tract focuses on the potential of ultrasonography to reduce the need for more invasive or radiating imaging, however, with additional fluoroscopy or MRI to be used in selected cases. Adherence to these recommendations will allow comparable data and evidence to be generated for future adaptation of imaging strategies in paediatric uroradiology.

  19. Image Quality of the Helioseismic and Magnetic Imager (HMI) Onboard the Solar Dynamics Observatory (SDO)

    NASA Technical Reports Server (NTRS)

    Wachter, R.; Schou, Jesper; Rabello-Soares, M. C.; Miles, J. W.; Duvall, T. L., Jr.; Bush, R. I.

    2011-01-01

    We describe the imaging quality of the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) as measured during the ground calibration of the instrument. We describe the calibration techniques and report our results for the final configuration of HMI. We present the distortion, modulation transfer function, stray light,image shifts introduced by moving parts of the instrument, best focus, field curvature, and the relative alignment of the two cameras. We investigate the gain and linearity of the cameras, and present the measured flat field.

  20. Dynamic Chest Image Analysis: Evaluation of Model-Based Pulmonary Perfusion Analysis With Pyramid Images

    DTIC Science & Technology

    2007-11-02

    Image Analysis aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the Dynamic Pulmonary Imaging technique 18,5,17,6. We have proposed and evaluated a multiresolutional method with an explicit ventilation model based on pyramid images for ventilation analysis. We have further extended the method for ventilation analysis to pulmonary perfusion. This paper focuses on the clinical evaluation of our method for

  1. Dynamics of hemispheric dominance for language assessed by magnetoencephalographic imaging

    PubMed Central

    Findlay, Anne M.; Ambrose, Josiah B.; Cahn-Weiner, Deborah A.; Houde, John F.; Honma, Susanne; Hinkley, Leighton B.N.; Berger, Mitchel S.; Nagarajan, Srikantan S.; Kirsch, Heidi E.

    2012-01-01

    Objective The goal of the current study was to examine the dynamics of language lateralization using magnetoencephalographic (MEG) imaging, to determine the sensitivity and specificity of MEG-imaging, and to determine if MEG-imaging can become a viable alternative to the intracarotid amobarbital procedure (IAP), the current gold-standard for preoperative language lateralization in neurosurgical candidates. Methods MEG was recorded during an auditory verb-generation task and imaging analysis of oscillatory activity was initially performed in 21 subjects with epilepsy, brain tumor, or arteriovenous malformation who had undergone IAP and MEG. Time-windows and brain regions-of-interest that best discriminated between IAP determined left or right dominant for language were identified. Parameters derived in the retrospective analysis, was applied to a prospective cohort of 14 patients and healthy controls. Results Power decreases in the beta-frequency band were consistently observed following auditory stimulation in inferior frontal, superior temporal, and parietal cortices; similar power decreases were also seen in inferior frontal cortex prior to and during overt verb generation. Language lateralization was clearly observed to be a dynamic process that is bilateral for several hundred milliseconds during periods of auditory perception and overt speech production. Correlation with the IAP was seen in 13 of 14 (93%) of prospective patients, with the test demonstrating a sensitivity of 100% and specificity of 92%. Interpretation Our results demonstrate excellent correlation between MEG imaging findings with the IAP for language lateralization, and provide new insights into the spatiotemporal dynamics of cortical speech processing. PMID:22522481

  2. Cascaded image analysis for dynamic crack detection in material testing

    NASA Astrophysics Data System (ADS)

    Hampel, U.; Maas, H.-G.

    Concrete probes in civil engineering material testing often show fissures or hairline-cracks. These cracks develop dynamically. Starting at a width of a few microns, they usually cannot be detected visually or in an image of a camera imaging the whole probe. Conventional image analysis techniques will detect fissures only if they show a width in the order of one pixel. To be able to detect and measure fissures with a width of a fraction of a pixel at an early stage of their development, a cascaded image analysis approach has been developed, implemented and tested. The basic idea of the approach is to detect discontinuities in dense surface deformation vector fields. These deformation vector fields between consecutive stereo image pairs, which are generated by cross correlation or least squares matching, show a precision in the order of 1/50 pixel. Hairline-cracks can be detected and measured by applying edge detection techniques such as a Sobel operator to the results of the image matching process. Cracks will show up as linear discontinuities in the deformation vector field and can be vectorized by edge chaining. In practical tests of the method, cracks with a width of 1/20 pixel could be detected, and their width could be determined at a precision of 1/50 pixel.

  3. Dynamic phase imaging and processing of moving biological organisms

    NASA Astrophysics Data System (ADS)

    Creath, Katherine; Goldstein, Goldie

    2012-03-01

    This paper describes recent advances in developing a new, novel interference Linnik microscope system and presents images and data of live biological samples. The specially designed optical system enables instantaneous 4-dimensional video measurements of dynamic motions within and among live cells without the need for contrast agents. "Label-free" measurements of biological objects in reflection using harmless light levels are possible without the need for scanning and vibration isolation. This instrument utilizes a pixelated phase mask enabling simultaneous measurement of multiple interference patterns taking advantage of the polarization properties of light enabling phase image movies in real time at video rates to track dynamic motions and volumetric changes. Optical thickness data are derived from phase images after processing to remove the background surface shape to quantify changes in cell position and volume. Data from a number of different pond organisms will be presented, as will measurements of human breast cancer cells with the addition of various agents that break down the cells. These data highlight examples of the image processing involved and the monitoring of different biological processes.

  4. Imaging red blood cell dynamics by quantitative phase microscopy.

    PubMed

    Popescu, Gabriel; Park, YoungKeun; Choi, Wonshik; Dasari, Ramachandra R; Feld, Michael S; Badizadegan, Kamran

    2008-01-01

    Red blood cells (RBCs) play a crucial role in health and disease, and structural and mechanical abnormalities of these cells have been associated with important disorders such as Sickle cell disease and hereditary cytoskeletal abnormalities. Although several experimental methods exist for analysis of RBC mechanical properties, optical methods stand out as they enable collecting mechanical and dynamic data from live cells without physical contact and without the need for exogenous contrast agents. In this report, we present quantitative phase microscopy techniques that enable imaging RBC membrane fluctuations with nanometer sensitivity at arbitrary time scales from milliseconds to hours. We further provide a theoretical framework for extraction of membrane mechanical and dynamical properties using time series of quantitative phase images. Finally, we present an experimental approach to extend quantitative phase imaging to 3-dimensional space using tomographic methods. By providing non-invasive methods for imaging mechanics of live cells, these novel techniques provide an opportunity for high-throughput analysis and study of RBC mechanical properties in health and disease.

  5. Imaging of dynamic ion signaling during root gravitropism.

    PubMed

    Monshausen, Gabriele B

    2015-01-01

    Gravitropic signaling is a complex process that requires the coordinated action of multiple cell types and tissues. Ca(2+) and pH signaling are key components of gravitropic signaling cascades and can serve as useful markers to dissect the molecular machinery mediating plant gravitropism. To monitor dynamic ion signaling, imaging approaches combining fluorescent ion sensors and confocal fluorescence microscopy are employed, which allow the visualization of pH and Ca(2+) changes at the level of entire tissues, while also providing high spatiotemporal resolution. Here, I describe procedures to prepare Arabidopsis seedlings for live cell imaging and to convert a microscope for vertical stage fluorescence microscopy. With this imaging system, ion signaling can be monitored during all phases of the root gravitropic response.

  6. Dynamic, Nondestructive Imaging of a Bioengineered Vascular Graft Endothelium

    PubMed Central

    Lu, Peng; Xu, Yong; Rylander, Christopher G.; Wang, Ge; Sapoznik, Etai; Criswell, Tracy; Lee, Sang Jin; Soker, Shay; Rylander, Marissa Nichole

    2013-01-01

    Bioengineering of vascular grafts holds great potential to address the shortcomings associated with autologous and conventional synthetic vascular grafts used for small diameter grafting procedures. Lumen endothelialization of bioengineered vascular grafts is essential to provide an antithrombogenic graft surface to ensure long-term patency after implantation. Conventional methods used to assess endothelialization in vitro typically involve periodic harvesting of the graft for histological sectioning and staining of the lumen. Endpoint testing methods such as these are effective but do not provide real-time information of endothelial cells in their intact microenvironment, rather only a single time point measurement of endothelium development. Therefore, nondestructive methods are needed to provide dynamic information of graft endothelialization and endothelium maturation in vitro. To address this need, we have developed a nondestructive fiber optic based (FOB) imaging method that is capable of dynamic assessment of graft endothelialization without disturbing the graft housed in a bioreactor. In this study we demonstrate the capability of the FOB imaging method to quantify electrospun vascular graft endothelialization, EC detachment, and apoptosis in a nondestructive manner. The electrospun scaffold fiber diameter of the graft lumen was systematically varied and the FOB imaging system was used to noninvasively quantify the affect of topography on graft endothelialization over a 7-day period. Additionally, results demonstrated that the FOB imaging method had a greater imaging penetration depth than that of two-photon microscopy. This imaging method is a powerful tool to optimize vascular grafts and bioreactor conditions in vitro, and can be further adapted to monitor endothelium maturation and response to fluid flow bioreactor preconditioning. PMID:23585885

  7. Evaluation of a novel laparoscopic camera for characterization of renal ischemia in a porcine model using digital light processing (DLP) hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Olweny, Ephrem O.; Tan, Yung K.; Faddegon, Stephen; Jackson, Neil; Wehner, Eleanor F.; Best, Sara L.; Park, Samuel K.; Thapa, Abhas; Cadeddu, Jeffrey A.; Zuzak, Karel J.

    2012-03-01

    Digital light processing hyperspectral imaging (DLP® HSI) was adapted for use during laparoscopic surgery by coupling a conventional laparoscopic light guide with a DLP-based Agile Light source (OL 490, Optronic Laboratories, Orlando, FL), incorporating a 0° laparoscope, and a customized digital CCD camera (DVC, Austin, TX). The system was used to characterize renal ischemia in a porcine model.

  8. Thrombus segmentation by texture dynamics from microscopic image sequences

    NASA Astrophysics Data System (ADS)

    Brieu, Nicolas; Serbanovic-Canic, Jovana; Cvejic, Ana; Stemple, Derek; Ouwehand, Willem; Navab, Nassir; Groher, Martin

    2010-03-01

    The genetic factors of thrombosis are commonly explored by microscopically imaging the coagulation of blood cells induced by injuring a vessel of mice or of zebrafish mutants. The latter species is particularly interesting since skin transparency permits to non-invasively acquire microscopic images of the scene with a CCD camera and to estimate the parameters characterizing the thrombus development. These parameters are currently determined by manual outlining, which is both error prone and extremely time consuming. Even though a technique for automatic thrombus extraction would be highly valuable for gene analysts, little work can be found, which is mainly due to very low image contrast and spurious structures. In this work, we propose to semi-automatically segment the thrombus over time from microscopic image sequences of wild-type zebrafish larvae. To compensate the lack of valuable spatial information, our main idea consists of exploiting the temporal information by modeling the variations of the pixel intensities over successive temporal windows with a linear Markov-based dynamic texture formalization. We then derive an image from the estimated model parameters, which represents the probability of a pixel to belong to the thrombus. We employ this probability image to accurately estimate the thrombus position via an active contour segmentation incorporating also prior and spatial information of the underlying intensity images. The performance of our approach is tested on three microscopic image sequences. We show that the thrombus is accurately tracked over time in each sequence if the respective parameters controlling prior influence and contour stiffness are correctly chosen.

  9. A Wide Dynamic Range Tapped Linear Array Image Sensor

    NASA Astrophysics Data System (ADS)

    Washkurak, William D.; Chamberlain, Savvas G.; Prince, N. Daryl

    1988-08-01

    Detectors for acousto-optic signal processing applications require fast transient response as well as wide dynamic range. There are two major choices of detectors: conductive or integration mode. Conductive mode detectors have an initial transient period before they reach then' i equilibrium state. The duration of 1 his period is dependent on light level as well as detector capacitance. At low light levels a conductive mode detector is very slow; response time is typically on the order of milliseconds. Generally. to obtain fast transient response an integrating mode detector is preferred. With integrating mode detectors. the dynamic range is determined by the charge storage capability of the tran-sport shift registers and the noise level of the image sensor. The conventional net hod used to improve dynamic range is to increase the shift register charge storage capability. To achieve a dynamic range of fifty thousand assuming two hundred noise equivalent electrons, a charge storage capability of ten million electrons would be required. In order to accommodate this amount of charge. unrealistic shift registers widths would be required. Therefore, with an integrating mode detector it is difficult to achieve a dynamic range of over four orders of magnitude of input light intensity. Another alternative is to solve the problem at the photodetector aml not the shift, register. DALSA's wide dynamic range detector utilizes an optimized, ion implant doped, profiled MOSFET photodetector specifically designed for wide dynamic range. When this new detector operates at high speed and at low light levels the photons are collected and stored in an integrating fashion. However. at bright light levels where transient periods are short, the detector switches into a conductive mode. The light intensity is logarithmically compressed into small charge packets, easily carried by the CCD shift register. As a result of the logarithmic conversion, dynamic ranges of over six orders of

  10. Imaging Cellular Dynamics with Spectral Relaxation Imaging Microscopy: Distinct Spectral Dynamics in Golgi Membranes of Living Cells

    NASA Astrophysics Data System (ADS)

    Lajevardipour, Alireza; Chon, James W. M.; Chattopadhyay, Amitabha; Clayton, Andrew H. A.

    2016-11-01

    Spectral relaxation from fluorescent probes is a useful technique for determining the dynamics of condensed phases. To this end, we have developed a method based on wide-field spectral fluorescence lifetime imaging microscopy to extract spectral relaxation correlation times of fluorescent probes in living cells. We show that measurement of the phase and modulation of fluorescence from two wavelengths permit the identification and determination of excited state lifetimes and spectral relaxation correlation times at a single modulation frequency. For NBD fluorescence in glycerol/water mixtures, the spectral relaxation correlation time determined by our approach exhibited good agreement with published dielectric relaxation measurements. We applied this method to determine the spectral relaxation dynamics in membranes of living cells. Measurements of the Golgi-specific C6-NBD-ceramide probe in living HeLa cells revealed sub-nanosecond spectral dynamics in the intracellular Golgi membrane and slower nanosecond spectral dynamics in the extracellular plasma membrane. We interpret the distinct spectral dynamics as a result of structural plasticity of the Golgi membrane relative to more rigid plasma membranes. To the best of our knowledge, these results constitute one of the first measurements of Golgi rotational dynamics.

  11. Imaging Cellular Dynamics with Spectral Relaxation Imaging Microscopy: Distinct Spectral Dynamics in Golgi Membranes of Living Cells.

    PubMed

    Lajevardipour, Alireza; Chon, James W M; Chattopadhyay, Amitabha; Clayton, Andrew H A

    2016-11-22

    Spectral relaxation from fluorescent probes is a useful technique for determining the dynamics of condensed phases. To this end, we have developed a method based on wide-field spectral fluorescence lifetime imaging microscopy to extract spectral relaxation correlation times of fluorescent probes in living cells. We show that measurement of the phase and modulation of fluorescence from two wavelengths permit the identification and determination of excited state lifetimes and spectral relaxation correlation times at a single modulation frequency. For NBD fluorescence in glycerol/water mixtures, the spectral relaxation correlation time determined by our approach exhibited good agreement with published dielectric relaxation measurements. We applied this method to determine the spectral relaxation dynamics in membranes of living cells. Measurements of the Golgi-specific C6-NBD-ceramide probe in living HeLa cells revealed sub-nanosecond spectral dynamics in the intracellular Golgi membrane and slower nanosecond spectral dynamics in the extracellular plasma membrane. We interpret the distinct spectral dynamics as a result of structural plasticity of the Golgi membrane relative to more rigid plasma membranes. To the best of our knowledge, these results constitute one of the first measurements of Golgi rotational dynamics.

  12. Imaging Cellular Dynamics with Spectral Relaxation Imaging Microscopy: Distinct Spectral Dynamics in Golgi Membranes of Living Cells

    PubMed Central

    Lajevardipour, Alireza; Chon, James W. M.; Chattopadhyay, Amitabha; Clayton, Andrew H. A.

    2016-01-01

    Spectral relaxation from fluorescent probes is a useful technique for determining the dynamics of condensed phases. To this end, we have developed a method based on wide-field spectral fluorescence lifetime imaging microscopy to extract spectral relaxation correlation times of fluorescent probes in living cells. We show that measurement of the phase and modulation of fluorescence from two wavelengths permit the identification and determination of excited state lifetimes and spectral relaxation correlation times at a single modulation frequency. For NBD fluorescence in glycerol/water mixtures, the spectral relaxation correlation time determined by our approach exhibited good agreement with published dielectric relaxation measurements. We applied this method to determine the spectral relaxation dynamics in membranes of living cells. Measurements of the Golgi-specific C6-NBD-ceramide probe in living HeLa cells revealed sub-nanosecond spectral dynamics in the intracellular Golgi membrane and slower nanosecond spectral dynamics in the extracellular plasma membrane. We interpret the distinct spectral dynamics as a result of structural plasticity of the Golgi membrane relative to more rigid plasma membranes. To the best of our knowledge, these results constitute one of the first measurements of Golgi rotational dynamics. PMID:27872481

  13. Animal evaluation of technetium-99m triamide mercaptide complexes as potential renal imaging agents

    SciTech Connect

    Eshima, D.; Taylor, A. Jr.; Fritzberg, A.R.; Kasina, S.; Hansen, L.; Sorenson, J.F.

    1987-07-01

    Technetium-99m mercaptoacetylglycylglycylglycine (MAG3), a (/sup 99m/Tc)triamide mercaptide (N3S) compound has been synthesized in an attempt to obviate the stereochemistry problems associated with the diamide dimercaptide (N2S2) ligands. Because initial studies have been promising, the terminal glycine on the MAG3 compound has been varied to create a new series of N3S compounds. Twelve new N3S complexes were initially screened in mice and the more promising complexes, /sup 99m/Tc mercaptoacetylgylcylglycyl-glycine ((/sup 99m/Tc)MAG3), /sup 99m/Tc mercaptoacetylgylcylglycyl-L-alanine ((/sup 99m/Tc)MAG2-Ala), and both complexes of /sup 99m/Tc mercaptoeacetylglycylglycyl-L-asparagine ((/sup 99m/Tc)MAG2-Asn) and /sup 99m/Tc mercaptoacetylglycylglycyl-L-glutamine ((/sup 99m/Tc)MAG2-Gln), were further evaluated in rats utilizing constant infusion blood clearances, extraction efficiencies and protein binding assays. The renal excretion of all these complexes compared favorably with simultaneously administered (/sup 131/I)OIH and (/sup 125/I)iothalamate. The triamide mercaptide complexes represent a new ligand class for /sup 99m/Tc, which may provide a variety of complexes for the evaluation of renal tubular function.

  14. Spectral imaging of microvascular function in a renal cell carcinoma after treatment with a vascular disrupting agent

    NASA Astrophysics Data System (ADS)

    Wankhede, Mamta; deDeugd, Casey; Siemann, Dietmar W.; Sorg, Brian S.

    2009-02-01

    Tumors are highly metabolically active and thus require ample oxygen and nutrients to proliferate. Neovasculature generated by angiogenesis is required for tumors to grow beyond a size of about 1-2mm. Functional tumor vasculature also provides an access point for development of distant metastases. Due to the importance of the microvasculature for tumor growth, proliferation, and metastasis, the microvasculature has emerged as a therapeutic target for treatment of solid tumors. We employed spectral imaging in a rodent window chamber model to observe and measure the oxygen transport function of tumor microvasculature in a human renal cell carcinoma after treatment with a fast acting vascular disrupting agent. Human Caki-1 cells were grown in a dorsal skin-fold window chamber in athymic nude mice. Spectral imaging was used to measure hemoglobin saturation immediately before, immediately after and also at 2, 4, 6, 8, 24 and 48 hours after administration of the tubulin binding agent OXi4503. Up to 4 hours after treatment, tumor microvasculature was disrupted from the tumor core towards the periphery as seen in deoxygenation as well as structural changes of the vasculature. Reoxygenation and neovascularization commenced from the periphery towards the core from 6 - 48 hours after treatment. The timing of the effects of vascular disrupting agents can influence scheduling of repeat treatments and combinatorial treatments such as chemotherapy and radiation therapy. Spectral imaging can potentially provide this information in certain laboratory models from endogenous signals with microvessel resolution.

  15. Dynamic Enhancement of B-Mode Cardiac Ultrasound Image Sequences.

    PubMed

    Perperidis, Antonios; Cusack, David; White, Audrey; McDicken, Norman; MacGillivray, Tom; Anderson, Tom

    2017-07-01

    Limited contrast, along with speckle and acoustic noise, can reduce the diagnostic value of echocardiographic images. This study introduces dynamic histogram-based intensity mapping (DHBIM), a novel approach employing temporal variations in the cumulative histograms of cardiac ultrasound images to contrast enhance the imaged structures. DHBIM is then combined with spatial compounding to compensate for noise and speckle. The proposed techniques are quantitatively assessed (32 clinical data sets) employing (i) standard image quality measures and (ii) the repeatability of routine clinical measurements, such as chamber diameter and wall thickness. DHBIM introduces a mean increase of 120.9% in tissue/chamber detectability, improving the overall repeatability of clinical measurements by 17%. The integrated approach of DHBIM followed by spatial compounding provides the best overall enhancement of image quality and diagnostic value, consistently outperforming the individual approaches and achieving a 401.4% average increase in tissue/chamber detectability with an associated 24.3% improvement in the overall repeatability of clinical measurements. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. In vivo multiphoton imaging of immune cell dynamics.

    PubMed

    Okada, Takaharu; Takahashi, Sonoko; Ishida, Azusa; Ishigame, Harumichi

    2016-11-01

    Multiphoton imaging has been utilized to analyze in vivo immune cell dynamics over the last 15 years. Particularly, it has deepened the understanding of how immune responses are organized by immune cell migration and interactions. In this review, we first describe the following technical advances in recent imaging studies that contributed to the new findings on the regulation of immune responses and inflammation. Improved multicolor imaging of immune cell behavior has revealed that their interactions are spatiotemporally coordinated to achieve efficient and long-term immunity. The use of photoactivatable and photoconvertible fluorescent proteins has increased duration and volume of cell tracking, even enabling the analysis of inter-organ migration of immune cells. In addition, visualization of immune cell activation using biosensors for intracellular calcium concentration and signaling molecule activities has started to give further mechanistic insights. Then, we also introduce recent imaging analyses of interactions between immune cells and non-immune cells including endothelial, fibroblastic, epithelial, and nerve cells. It is argued that future imaging studies that apply updated technical advances to analyze interactions between immune cells and non-immune cells will be important for thorough physiological understanding of the immune system.

  17. Dynamic full-field infrared imaging with multiple synchrotron beams

    PubMed Central

    Stavitski, Eli; Smith, Randy J.; Bourassa, Megan W.; Acerbo, Alvin S.; Carr, G. L.; Miller, Lisa M.

    2013-01-01

    Microspectroscopic imaging in the infrared (IR) spectral region allows for the examination of spatially resolved chemical composition on the microscale. More than a decade ago, it was demonstrated that diffraction limited spatial resolution can be achieved when an apertured, single pixel IR microscope is coupled to the high brightness of a synchrotron light source. Nowadays, many IR microscopes are equipped with multi-pixel Focal Plane Array (FPA) detectors, which dramatically improve data acquisition times for imaging large areas. Recently, progress been made toward efficiently coupling synchrotron IR beamlines to multi-pixel detectors, but they utilize expensive and highly customized optical schemes. Here we demonstrate the development and application of a simple optical configuration that can be implemented on most existing synchrotron IR beamlines in order to achieve full-field IR imaging with diffraction-limited spatial resolution. Specifically, the synchrotron radiation fan is extracted from the bending magnet and split into four beams that are combined on the sample, allowing it to fill a large section of the FPA. With this optical configuration, we are able to oversample an image by more than a factor of two, even at the shortest wavelengths, making image restoration through deconvolution algorithms possible. High chemical sensitivity, rapid acquisition times, and superior signal-to-noise characteristics of the instrument are demonstrated. The unique characteristics of this setup enabled the real time study of heterogeneous chemical dynamics with diffraction-limited spatial resolution for the first time. PMID:23458231

  18. Dynamic Magnetic Resonance Imaging of the Pharynx During Deglutition

    PubMed Central

    Amin, Milan R.; Achlatis, Stratos; Lazarus, Cathy L.; Branski, Ryan C.; Storey, E. Pippa; Praminik, Bidyut; Fang, Yixin; Sodickson, Daniel

    2014-01-01

    Objectives To utilize dynamic magnetic resonance imaging (dMRI) to visualize the pharynx and upper esophageal segment in normal, healthy controls. Methods A 3-T scanner with a 4-channel head coil and a dual-channel neck coil was employed to obtain hsMRI images of subjects swallowing liquids and pudding. Thirty sequential images were acquired over 3300ms for each swallow. Imaging was performed in the midsagittal and axial plane at the level of the oropharynx and pharyngoesophageal segment. Axial images were then analyzed for variables related to alterations in pharyngeal and UES area during swallowing as well as temporal measures related to these structures. Results All subjects tolerated the study protocol without complaint. Changes in pharyngeal wall luminal area and temporal measurements were consistent within and between subjects. Inter- and intra-rater reliability for the measurement tool was excellent. Conclusions dMRI of the swallow sequence is both feasible and reliable and may eventually compliment currently-used diagnostic modalities as it adds substantive information. PMID:23577565

  19. Dynamic contrast enhanced magnetic resonance imaging in chronic Achilles tendinosis.

    PubMed

    Gärdin, Anna; Brismar, Torkel B; Movin, Tomas; Shalabi, Adel

    2013-11-22

    Chronic Achilles tendinosis is a common problem. When evaluating and comparing different therapies there is a need for reliable imaging methods. Our aim was to evaluate if chronic Achilles tendinosis affects the dynamic contrast-enhancement in the tendon and its surroundings and if short-term eccentric calf-muscle training normalizes the dynamic contrast-enhancement. 20 patients with chronic Achilles tendinopathy were included. Median duration of symptoms was 31 months (range 6 to 120 months). Both Achilles tendons were examined with dynamic contrast enhanced MRI before and after a 12- week exercise programme of eccentric calf-muscle training. Th