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  1. Transmission grating stretcher for contrast enhancement of high power lasers.

    Science.gov (United States)

    Tang, Yunxin; Hooker, Chris; Chekhlov, Oleg; Hawkes, Steve; Collier, John; Rajeev, P P

    2014-12-01

    We propose, for the first time, a transmission grating stretcher for high power lasers and demonstrate its superiority over conventional, reflective gold grating stretchers in terms of pulse temporal quality. We show that, compared to a conventional stretcher with the same stretching factor, the transmission-grating based stretcher yields more than an order of magnitude improvement in the contrast pedestal. We have also quantitatively characterized the roughness of the grating surfaces and estimated its impact on the contrast pedestal.

  2. High Atomic Number Contrast Media Offer Potential for Radiation Dose Reduction in Contrast-Enhanced Computed Tomography.

    Science.gov (United States)

    Roessler, Ann-Christin; Hupfer, Martin; Kolditz, Daniel; Jost, Gregor; Pietsch, Hubertus; Kalender, Willi A

    2016-04-01

    Spectral optimization of x-ray computed tomography (CT) has led to substantial radiation dose reduction in contrast-enhanced CT studies using standard iodinated contrast media. The purpose of this study was to analyze the potential for further dose reduction using high-atomic-number elements such as hafnium and tungsten. As in previous studies, spectra were determined for which the patient dose necessary to provide a given contrast-to-noise ratio (CNR) is minimized. We used 2 different quasi-anthropomorphic phantoms representing the liver cross-section of a normal adult and an obese adult patient with the lateral widths of 360 and 460 mm and anterior-posterior heights of 200 and 300 mm, respectively. We simulated and measured on 2 different scanners with x-ray spectra from 80 to 140 kV and from 70 to 150 kV, respectively. We determined the contrast for iodine-, hafnium-, and tungsten-based contrast media, the noise, and 3-dimensional dose distributions at all available tube voltages by measurements and by simulations. The dose-weighted CNR was determined as optimization parameter. Simulations and measurements were in good agreement regarding their dependence on energy for all parameters investigated. Hafnium provided the best performance for normal and for obese patient phantoms, indicating a dose reduction potential of 30% for normal and 50% for obese patients at 120 kV compared with iodine; this advantage increased further with higher kV values. Dose-weighted CNR values for tungsten were always slightly below the hafnium results. Iodine proved to be the superior choice at voltage values of 80 kV and below. Hafnium and tungsten both seem to be candidates for contrast-medium-enhanced CT of normal and obese adult patients with strongly reduced radiation dose at unimpaired image quality. Computed tomography examinations of obese patients will decrease in dose for higher kV values.

  3. Phase contrast enhanced high resolution X-ray imaging and tomography of soft tissue

    Energy Technology Data Exchange (ETDEWEB)

    Jakubek, Jan [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Granja, Carlos [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic)]. E-mail: carlos.granja@utef.cvut.cz; Dammer, Jiri [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Hanus, Robert [Institute of Organic Chemistry and Biochemistry, Academy of Sciences, CZ-166 10 Prague 6 (Czech Republic); Holy, Tomas [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Pospisil, Stanislav [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Tykva, Richard [Institute of Organic Chemistry and Biochemistry, Academy of Sciences, CZ-166 10 Prague 6 (Czech Republic); Uher, Josef [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Vykydal, Zdenek [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic)

    2007-02-01

    A tabletop system for digital high resolution and high sensitivity X-ray micro-radiography has been developed for small-animal and soft-tissue imaging. The system is based on a micro-focus X-ray tube and the semiconductor hybrid position sensitive Medipix2 pixel detector. Transmission radiography imaging, conventionally based only on absorption, is enhanced by exploiting phase-shift effects induced in the X-ray beam traversing the sample. Phase contrast imaging is realized by object edge enhancement. DAQ is done by a novel fully integrated USB-based readout with online image generation. Improved signal reconstruction techniques make use of advanced statistical data analysis, enhanced beam hardening correction and direct thickness calibration of individual pixels. 2D and 3D micro-tomography images of several biological samples demonstrate the applicability of the system for biological and medical purposes including in-vivo and time dependent physiological studies in the life sciences.

  4. Tunable Resonant-Cavity-Enhanced Photodetector with Double High-Index-Contrast Grating Mirrors

    DEFF Research Database (Denmark)

    Learkthanakhachon, Supannee; Yvind, Kresten; Chung, Il-Sug

    2013-01-01

    In this paper, we propose a broadband-tunable resonant-cavity-enhanced photodetector (RCE-PD) structure with double high-index-contrast grating (HCG) mirrors and numerically investigate its characteristics. The detector is designed to operate at 1550-nm wavelength. The detector structure consists...... of a top InP HCG mirror, a p-i-n photodiode embedding multiple quantum wells, and a Si HCG mirror formed in the Si layer of a silicon-on-insulator wafer. The detection wavelength can be changed by moving the top InP HCG mirror suspended in the air. High reflectivity and small penetration length of HCGs...

  5. High sensitivity contrast enhanced optical coherence tomography for functional in vivo imaging

    Science.gov (United States)

    Liba, Orly; SoRelle, Elliott D.; Sen, Debasish; de la Zerda, Adam

    2017-02-01

    In this study, we developed and applied highly-scattering large gold nanorods (LGNRs) and custom spectral detection algorithms for high sensitivity contrast-enhanced optical coherence tomography (OCT). We were able to detect LGNRs at a concentration as low as 50 pM in blood. We used this approach for noninvasive 3D imaging of blood vessels deep in solid tumors in living mice. Additionally, we demonstrated multiplexed imaging of spectrally-distinct LGNRs that enabled observations of functional drainage in lymphatic networks. This method, which we call MOZART, provides a platform for molecular imaging and characterization of tissue noninvasively at cellular resolution.

  6. Novel Gd nanoparticles enhance vascular contrast for high-resolution magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Tot Bui

    2010-09-01

    Full Text Available Gadolinium (Gd, with its 7 unpaired electrons in 4f orbitals that provide a very large magnetic moment, is proven to be among the best agents for contrast enhanced MRI. Unfortunately, the most potent MR contrast agent based on Gd requires relatively high doses of Gd. The Gd-chelated to diethylene-triamine-penta-acetic acid (DTPA, or other derivatives (at 0.1 mmole/kg recommended dose, distribute broadly into tissues and clear through the kidney. These contrast agents carry the risk of Nephrogenic Systemic Fibrosis (NSF, particularly in kidney impaired subjects. Thus, Gd contrast agents that produce higher resolution images using a much lower Gd dose could address both imaging sensitivity and Gd safety.To determine whether a biocompatible lipid nanoparticle with surface bound Gd can improve MRI contrast sensitivity, we constructed Gd-lipid nanoparticles (Gd-LNP containing lipid bound DTPA and Gd. The Gd-LNP were intravenously administered to rats and MR images collected. We found that Gd in Gd-LNP produced a greater than 33-fold higher longitudinal (T(1 relaxivity, r(1, constant than the current FDA approved Gd-chelated contrast agents. Intravenous administration of these Gd-LNP at only 3% of the recommended clinical Gd dose produced MRI signal-to-noise ratios of greater than 300 in all vasculatures. Unlike current Gd contrast agents, these Gd-LNP stably retained Gd in normal vasculature, and are eliminated predominately through the biliary, instead of the renal system. Gd-LNP did not appear to accumulate in the liver or kidney, and was eliminated completely within 24 hrs.The novel Gd-nanoparticles provide high quality contrast enhanced vascular MRI at 97% reduced dose of Gd and do not rely on renal clearance. This new agent is likely to be suitable for patients exhibiting varying degrees of renal impairment. The simple and adaptive nanoparticle design could accommodate ligand or receptor coating for drug delivery optimization and in vivo drug

  7. Contrast-enhanced peripheral MRA

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Thomsen, Henrik S

    2012-01-01

    -state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged......In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast...... MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic...

  8. Ultra-high field upper extremity peripheral nerve and non-contrast enhanced vascular imaging.

    Directory of Open Access Journals (Sweden)

    Shailesh B Raval

    Full Text Available The purpose of this study was to explore the efficacy of Ultra-high field [UHF] 7 Tesla [T] MRI as compared to 3T MRI in non-contrast enhanced [nCE] imaging of structural anatomy in the elbow, forearm, and hand [upper extremity].A wide range of sequences including T1 weighted [T1] volumetric interpolate breath-hold exam [VIBE], T2 weighted [T2] double-echo steady state [DESS], susceptibility weighted imaging [SWI], time-of-flight [TOF], diffusion tensor imaging [DTI], and diffusion spectrum imaging [DSI] were optimized and incorporated with a radiofrequency [RF] coil system composed of a transverse electromagnetic [TEM] transmit coil combined with an 8-channel receive-only array for 7T upper extremity [UE] imaging. In addition, Siemens optimized protocol/sequences were used on a 3T scanner and the resulting images from T1 VIBE and T2 DESS were compared to that obtained at 7T qualitatively and quantitatively [SWI was only qualitatively compared]. DSI studio was utilized to identify nerves based on analysis of diffusion weighted derived fractional anisotropy images. Images of forearm vasculature were extracted using a paint grow manual segmentation method based on MIPAV [Medical Image Processing, Analysis, and Visualization].High resolution and high quality signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]-images of the hand, forearm, and elbow were acquired with nearly homogeneous 7T excitation. Measured [performed on the T1 VIBE and T2 DESS sequences] SNR and CNR values were almost doubled at 7T vs. 3T. Cartilage, synovial fluid and tendon structures could be seen with higher clarity in the 7T T1 and T2 weighted images. SWI allowed high resolution and better quality imaging of large and medium sized arteries and veins, capillary networks and arteriovenous anastomoses at 7T when compared to 3T. 7T diffusion weighted sequence [not performed at 3T] demonstrates that the forearm nerves are clearly delineated by fiber tractography. The

  9. Innovations in contrast enhanced high resolution ultrasound improve sonographic imaging of the intestine.

    Science.gov (United States)

    Girlich, C; Schacherer, D; Lamby, P; Scherer, M N; Schreyer, A G; Jung, E M

    2010-01-01

    The aim was to describe the perfusion pattern of the inflamed bowel wall and the surrounding tissue in inflammatory bowel disease and diverticulitis of the sigmoid colon applying a high resolution matrix transducer and the new hybrid technique. We performed contrast enhanced ultrasound (CEUS) using an updated version of the 1-5 MHz (C1-5-D convex probe) and the 6-9 MHz probe (9L-D linear probe) as well as a matrix 6-15 MHz transducer (ML 6-15-D Matrix Array Linear Probe) and updated post-processing procedures to examine microvascularization of inflamed bowel wall in Crohn's disease (11 patients), ulcerative colitis (1 patient) and diverticulitis of the sigmoid colon (2 patients). Assessment of mural microvascularization was successful as well as identification of fistulas (2 patients) and covered perforation (1 patient). Moreover analysis of time intensity curves revealed increase of signal intensity up to 20 dB. Summarizing, application of high resolution linear probes and use of updated post-processing methods substantially improve detection of inflammation-caused increased microcirculation of the bowel wall and the surrounding tissue as well as identification of complications as fistulas or covered perforations.

  10. Highly accelerated first-pass contrast-enhanced magnetic resonance angiography of the peripheral vasculature: comparison of gadofosveset trisodium with gadopentetate dimeglumine contrast agents.

    Science.gov (United States)

    Maki, Jeffrey H; Wang, Maisie; Wilson, Gregory J; Shutske, Matthew G; Leiner, Tim

    2009-11-01

    To investigate the blood pool agent gadofosveset trisodium for first-pass, dynamic peripheral contrast-enhanced magnetic resonance angiography (pMRA), and compare the results with a conventional gadolinium contrast agent. A total of 16 patients were imaged at 1.5T using a prototype peripheral vascular coil with high SENSE acceleration. Five received gadopentetate dimeglumine ( approximately 0.25 mmol/kg), and 11 received gadofosveset trisodium (five standard-dose 0.03 mmol/kg, six high-dose 0.05 mmol/kg). Quantitative contrast-enhancement and qualitative image quality evaluation was compared between agents and doses. High-quality diagnostic images were uniformly obtained. The contrast ratio did not significantly differ between gadopentetate dimeglumine and high-dose gadofosveset trisodium, both of which were greater than standard-dose gadofosveset trisodium. High-dose gadofosveset trisodium was equivalent to gadopentetate dimeglumine in image quality and subjective vessel-to-background ratio, but significantly better for depicting small muscular arteries. Standard-dose gadofosveset trisodium showed equivalent image quality and small artery depiction with a slight but significant decrease in vessel-to-background ratio as compared to gadopentatate dimeglumine. Both gadofosveset trisodium doses trended toward more venous enhancement, but this was not a diagnostic problem. First-pass peripheral CE-MRA using gadofosveset trisodium is feasible, yielding image quality comparable to double to triple-dose gadopentetate dimeglumine. Increasing the gadofosveset trisodium dose to 0.05 mmol/kg yields further improvements.

  11. Fuzzy-Contextual Contrast Enhancement.

    Science.gov (United States)

    Parihar, Anil; Verma, Om; Khanna, Chintan

    2017-02-08

    This paper presents contrast enhancement algorithms based on fuzzy contextual information of the images. We introduce fuzzy similarity index and fuzzy contrast factor to capture the neighborhood characteristics of a pixel. A new histogram, using fuzzy contrast factor of each pixel is developed, and termed as the fuzzy dissimilarity histogram (FDH). A cumulative distribution function (CDF) is formed with normalized values of FDH and used as a transfer function to obtain the contrast enhanced image. The algorithm gives good contrast enhancement and preserves the natural characteristic of the image. In order to develop a contextual intensity transfer function, we introduce a fuzzy membership function based on fuzzy similarity index and coefficient of variation of the image. The contextual intensity transfer function is designed using the fuzzy membership function to achieve final contrast enhanced image. The overall algorithm is referred as the fuzzy contextual contrast-enhancement (FCCE) algorithm. The proposed algorithms are compared with conventional and state-of-art contrast enhancement algorithms. The quantitative and visual assessment of the results is performed. The results of quantitative measures are statistically analyzed using t-test. The exhaustive experimentation and analysis show the proposed algorithm efficiently enhances contrast and yields in natural visual quality images.

  12. Fat suppression techniques for obtaining high resolution dynamic contrast enhanced bilateral breast MR images at 7T

    NARCIS (Netherlands)

    van der Velden, Tijl A; Schmitz, Alexander M Th; Gilhuijs, Kenneth G A; Veldhuis, Wouter B; Luijten, Peter R; Boer, Vincent O; Klomp, DWJ

    2016-01-01

    OBJECTIVES: To compare water selective excitation (WSE) and Dixon fat suppression in the context of high-resolution dynamic contrast enhanced MRI of the breast at 7T. METHODS: Ten healthy volunteers and one patient with a malignant breast lesion were scanned at 7T. The MRI protocol contained 3D

  13. Fat suppression techniques for obtaining high resolution dynamic contrast enhanced bilateral breast MR images at 7 tesla

    DEFF Research Database (Denmark)

    van der Velden, Tijl A; Schmitz, Alexander M Th; Gilhuijs, Kenneth G A

    2016-01-01

    OBJECTIVES: To compare water selective excitation (WSE) and Dixon fat suppression in the context of high-resolution dynamic contrast enhanced MRI of the breast at 7 tesla. METHODS: Ten healthy volunteers and one patient with a malignant breast lesion were scanned at 7 tesla. The MRI protocol...

  14. Diagnosis of the hypothenar hammer syndrome by high-resolution contrast-enhanced MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Winterer, J.T.; Ghanem, N.; Schaefer, O.; Lehnhardt, S.; Thuerl, C.; Laubenberger, J. [Department of Diagnostic Radiology, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany); Roth, M. [Center of Geriatric Medicine and Gerontology Freiburg, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany); Horch, R.E. [Department of Plastic and Hand Surgery, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany)

    2002-10-01

    Our objective was to describe the imaging features of hypothenar hammer syndrome using minimally invasive contrast-enhanced MR angiography in comparison with oscillography study. In five patients with hypothenar hammer syndrome Gd-BOPTA-enhanced elliptically reordered 3D pulse sequence MR was compared with oscillography findings and clinical symptoms focusing on angiographic appearance of vessel injury, distribution pattern of hand vasculature and joining branches between the radial and ulnar artery supply. All patients showed segmental occlusion at the site of trauma impact with varying involvement of the superficial palmar arch, common volar digital arteries. Embolic disease was present in 50% of patients and could be clearly identified with MRA. Good correspondence was found between angiographic appearance including the presence of collaterals, clinical symptoms and oscillography. Bilateral comparison was helpful in distinguishing between vessel variants and pathology. Bilateral Gd-BOPTA-enhanced MR angiography is a minimally invasive method to depict clearly the localization and extent of vessel injury in hypothenar hammer syndrome providing valuable information about distribution pattern of hand vasculature and presence of collaterals; however, no flow data can be obtained. (orig.)

  15. Evaluation of fast highly undersampled contrast-enhanced MR angiography (sparse CE-MRA) in intracranial applications - initial study

    Energy Technology Data Exchange (ETDEWEB)

    Gratz, Marcel; Quick, Harald H. [University of Duisburg-Essen, Erwin L. Hahn Institute for MR Imaging, Essen (Germany); University Hospital Essen, High Field and Hybrid MR Imaging, Essen (Germany); Schlamann, Marc [University Hospital Giessen and Marburg GmbH, Neuroradiology, Giessen (Germany); University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Goericke, Sophia [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Maderwald, Stefan [University of Duisburg-Essen, Erwin L. Hahn Institute for MR Imaging, Essen (Germany)

    2017-03-15

    To assess the image quality of sparsely sampled contrast-enhanced MR angiography (sparse CE-MRA) providing high spatial resolution and whole-head coverage. Twenty-three patients scheduled for contrast-enhanced MR imaging of the head, (N = 19 with intracranial pathologies, N = 9 with vascular diseases), were included. Sparse CE-MRA at 3 Tesla was conducted using a single dose of contrast agent. Two neuroradiologists independently evaluated the data regarding vascular visibility and diagnostic value of overall 24 parameters and vascular segments on a 5-point ordinary scale (5 = very good, 1 = insufficient vascular visibility). Contrast bolus timing and the resulting arterio-venous overlap was also evaluated. Where available (N = 9), sparse CE-MRA was compared to intracranial Time-of-Flight MRA. The overall rating across all patients for sparse CE-MRA was 3.50 ± 1.07. Direct influence of the contrast bolus timing on the resulting image quality was observed. Overall mean vascular visibility and image quality across different features was rated good to intermediate (3.56 ± 0.95). The average performance of intracranial Time-of-Flight was rated 3.84 ± 0.87 across all patients and 3.54 ± 0.62 across all features. Sparse CE-MRA provides high-quality 3D MRA with high spatial resolution and whole-head coverage within short acquisition time. Accurate contrast bolus timing is mandatory. (orig.)

  16. "Pseudo washout" sign in high-flow hepatic hemangioma on gadoxetic acid contrast-enhanced MRI mimicking hypervascular tumor.

    Science.gov (United States)

    Doo, Kyung Won; Lee, Chang Hee; Choi, Jae Woong; Lee, Jongmee; Kim, Kyeong Ah; Park, Cheol Min

    2009-12-01

    The purpose of this article is to describe the "pseudo washout" sign of high-flow hepatic hemangioma that mimics hypervascular tumor on gadoxetic acid-enhanced MRI. High-flow hemangiomas might show relatively low signal intensity because of gadoxetic acid contrast uptake in the surrounding normal liver parenchyma during the equilibrium (3-minute delay) phase. Such findings are called pseudo washout and can mimic hypervascular hepatic tumors. However, high-flow hemangioma can be diagnosed by observing bright signal intensity on T2-weighted imaging, arterial phase-dominant enhancement, pseudo washout sign during the equilibrium phase, and isointense or slightly increased signal intensity on subtraction images.

  17. Nomarski serial time-encoded amplified microscopy for high-speed contrast-enhanced imaging of transparent media.

    Science.gov (United States)

    Fard, Ali M; Mahjoubfar, Ata; Goda, Keisuke; Gossett, Daniel R; Di Carlo, Dino; Jalali, Bahram

    2011-12-01

    High-speed high-contrast imaging modalities that enable image acquisition of transparent media without the need for chemical staining are essential tools for a broad range of applications; from semiconductor process monitoring to blood screening. Here we introduce a method for contrast-enhanced imaging of unstained transparent objects that is capable of high-throughput imaging. This method combines the Nomarski phase contrast capability with the ultrahigh frame rate and shutter speed of serial time-encoded amplified microscopy. As a proof of concept, we show imaging of a transparent test structure and white blood cells in flow at a shutter speed of 33 ps and a frame rate of 36.1 MHz using a single-pixel photo-detector. This method is expected to be a valuable tool for high-throughput screening of unstained cells.

  18. Low enhancement on multiphase contrast-enhanced CT images: an independent predictor of the presence of high tumor grade of clear cell renal cell carcinoma.

    Science.gov (United States)

    Zhu, Ye-Hua; Wang, Xun; Zhang, Jin; Chen, Yong-Hui; Kong, Wen; Huang, Yi-Ran

    2014-09-01

    The purpose of this study was to assess the relation between tumor enhancement on multiphase contrast-enhanced CT images and Fuhrman grade of clear cell renal cell carcinoma. A single-institution retrospective review was conducted on the records of 255 patients who underwent radical or partial nephrectomy and received a histologic diagnosis of clear cell renal cell carcinoma. Two radiologists recorded the radiographic features of each patient, including the attenuation value of the lesion, lesion size, calcification within the lesion, cystic versus solid appearance, and margin regularity. Parameters representing the extent of tumor enhancement were defined and calculated. The association between tumor enhancement and Fuhrman grade was analyzed, and multivariate analysis was performed to find independent predictors of high tumor grade. Significant differences existed in tumor enhancement among different Fuhrman grades (p enhancement (p enhancement parameter had a sensitivity of 0.84 and specificity of 0.93 in prediction of high tumor grade. In the multivariate analysis, more advanced age, irregular margin, and low tumor enhancement were the three independent predictors of high tumor grade. Tumor enhancement of clear cell renal cell carcinoma on multiphase contrast-enhanced CT images is associated with Fuhrman grade. Low tumor enhancement in the corticomedullary phase is an independent predictor of high tumor grade. This system may be helpful in clinical decision making about the care of patients treated by nonsurgical approaches.

  19. Contrast-enhanced digital mammography.

    Science.gov (United States)

    Jochelson, Maxine

    2014-05-01

    Mammography is the only technology documented to reduce breast cancer mortality. Its sensitivity, however, is 75% to 80% at best and reduced to 30% to 50% in women with dense breasts. MR imaging is a sensitive modality for the detection of breast cancer but cannot be used in all patients. Its sensitivity is due in large part to its ability to detect enhancement of tumor vascularity so cancers can be detected before a mass is present. Contrast-enhanced dual-energy mammography uses the same capability of vascular enhancement and has been demonstrated to be more sensitive than routine mammography. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Commercialization of vein contrast enhancement

    Science.gov (United States)

    Lovhoiden, Gunnar; Deshmukh, Harshal; Vrancken, Carlos; Zhang, Yong; Zeman, Herbert D.; Weinberg, Devin

    2003-07-01

    An ongoing clinical study of an experimental infrared (IR) device, the Vein Contrast Enhancer (VCE) that visualizes surface veins for medical access, indicates that a commercial device with the performance of the existing VCE would have significant clinical utility for even a very skilled phlebotomist. A proof-of-principle prototype VCE device has now been designed and constructed that captures IR images of surface veins with a commercial CCD camera, transfers the images to a PC for real-time software image processing to enhance the vein contrast, and projects the enhanced images back onto the skin with a modified commercial LCD projector. The camera and projector are mounted on precision slides allowing for precise mechanical alignment of the two optical axes and for measuring the effects of axes misalignment. Precision alignment of the captured and projected images over the entire field-of-view is accomplished electronically by software adjustments of the translation, scaling, and rotation of the enhanced images before they are projected back onto the skin. This proof-of-principle prototype will be clinically tested and the experience gained will lead to the development of a commercial device, OnTarget!, that is compact, easy to use, and will visualize accessible veins in almost all subjects needing venipuncture.

  1. Therapeutic response assessment of high intensity focused ultrasound therapy for uterine fibroid: Utility of contrast-enhanced ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Xiaodong [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China)]. E-mail: zhouxd@fmmu.edu.cn; Ren Xiaolong [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China)]. E-mail: renxiaolong70@hotmail.com; Zhang Jun [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China); He Guangbin [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China); Zheng Minjuan [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China); Tian Xue [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China); Li Li [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China); Zhu Ting [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China); Zhang Min [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China); Wang Lei [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China); Luo Wen [Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China)

    2007-05-15

    Purpose: To assess the utility of contrast-enhanced ultrasonography (ceUS) in the assessment of the therapeutic response to high intensity focused ultrasound (HIFU) ablation in patients with uterine fibroid. Materials and methods: Sixty-four patients with a total of 64 uterine fibroids (mean: 5.3 {+-} 1.2 cm; range: 3.2-8.9 cm) treated with HIFU ablation under the ultrasound guidance were evaluated with ceUS after receiving an intravenous bolus injection of a microbubble contrast agent (SonoVue) within 1 week after intervention. We obtained serial ceUS images during the time period from beginning to 5 min after the initiation of the bolus contrast injection. All of the patients underwent a contrast enhanced MRI (ceMRI) and ultrasound guided needle puncture biopsy within 1 week after HIFU ablation. And as a follow-up, all of the patients underwent US at 1, 3, 6 and 12 months after HIFU treatment. The volume change was observed and compared to pre- and post-HIFU ablation. The results of the ceUS were compared with those of the ceMRI in terms of the presence or absence of residual unablated tumor and pathologic change in the treated lesions. Results: On ceUS, diagnostic accuracy was 100%, while residual unablated tumors were found in three uterine fibroids (4.7%) and failed treatment was found in eight uterine fibroids (12.5%). All the 11 fibroids were subjected to additional HIFU ablation. Of the 58 ablated fibroids without residual tumors on both the ceUS and ceMRI after the HIFU ablation, the volumes of all the fibroids decreased in different degrees during the 1 year follow-up USs. And histologic examinations confirmed findings of necrotic and viable tumor tissue, respectively. Conclusion: CEUS is potentially useful for evaluating the early therapeutic effect of percutaneous HIFU ablation for uterine fibroids.

  2. Fat suppression techniques for obtaining high resolution dynamic contrast enhanced bilateral breast MR images at 7T.

    Science.gov (United States)

    van der Velden, Tijl A; Schmitz, Alexander M Th; Gilhuijs, Kenneth G A; Veldhuis, Wouter B; Luijten, Peter R; Boer, Vincent O; Klomp, Dennis W J

    2016-05-01

    To compare water selective excitation (WSE) and Dixon fat suppression in the context of high-resolution dynamic contrast enhanced MRI of the breast at 7T. Ten healthy volunteers and one patient with a malignant breast lesion were scanned at 7T. The MRI protocol contained 3D T1-weighted gradient echo images obtained with both WSE fat suppression, multi echo Dixon fat suppression, and without fat suppression. Images were acquired at a (0.8mm)(3) or (0.7mm)(3) isotropic resolution with equal field of view and optimized such to obtain a maximal SNR. Image quality was scored qualitatively on overall image quality, sharpness of anatomical details, presence of artifacts, inhomogeneous fat suppression and the presence of water-fat shift. A quantitative scoring was obtained from the signal to noise ratio and contrast to noise ratio. WSE scored significantly better in terms of overall image quality and the absence of artifacts. No significant difference in contrast to noise ratio was found between the two fat suppression methods. When maximizing temporal and spatial resolution of high resolution DCE MRI of the breast, water selective excitation provides better image quality than multi echo Dixon at 7T. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Retooling Laser Speckle Contrast Analysis Algorithm to Enhance Non-Invasive High Resolution Laser Speckle Functional Imaging of Cutaneous Microcirculation

    Science.gov (United States)

    Gnyawali, Surya C.; Blum, Kevin; Pal, Durba; Ghatak, Subhadip; Khanna, Savita; Roy, Sashwati; Sen, Chandan K.

    2017-01-01

    Cutaneous microvasculopathy complicates wound healing. Functional assessment of gated individual dermal microvessels is therefore of outstanding interest. Functional performance of laser speckle contrast imaging (LSCI) systems is compromised by motion artefacts. To address such weakness, post-processing of stacked images is reported. We report the first post-processing of binary raw data from a high-resolution LSCI camera. Sharp images of low-flowing microvessels were enabled by introducing inverse variance in conjunction with speckle contrast in Matlab-based program code. Extended moving window averaging enhanced signal-to-noise ratio. Functional quantitative study of blood flow kinetics was performed on single gated microvessels using a free hand tool. Based on detection of flow in low-flow microvessels, a new sharp contrast image was derived. Thus, this work presents the first distinct image with quantitative microperfusion data from gated human foot microvasculature. This versatile platform is applicable to study a wide range of tissue systems including fine vascular network in murine brain without craniotomy as well as that in the murine dorsal skin. Importantly, the algorithm reported herein is hardware agnostic and is capable of post-processing binary raw data from any camera source to improve the sensitivity of functional flow data above and beyond standard limits of the optical system.

  4. Enhanced Kα output of Ar and Kr using size optimized cluster target irradiated by high-contrast laser pulses.

    Science.gov (United States)

    Zhang, Lu; Chen, Li-Ming; Yuan, Da-Wei; Yan, Wen-Chao; Wang, Zhao-Hua; Liu, Cheng; Shen, Zhong-Wei; Faenov, Anatoly; Pikuz, Tatiana; Skobelev, Igor; Gasilov, Vladimir; Boldarev, Alexei; Mao, Jing-Yi; Li, Yu-Tong; Dong, Quan-Li; Lu, Xin; Ma, Jing-Long; Wang, Wei-Ming; Sheng, Zheng-Ming; Zhang, Jie

    2011-12-05

    We observed that increasing the clusters size and laser pulse contrast can enhance the X-ray flux emitted by femtosecond-laser-driven-cluster plasma. By focusing a high contrast laser (10(-10)) on large argon clusters, high flux Kα-like X-rays (around 2.96 keV) is generated with a total flux of 2.5 × 10(11) photons/J in 4π and a conversion efficiency of 1.2 × 10-4. In the case of large Kr clusters, the best total flux for L-shell X-rays is 5.3 × 1011 photons/J with a conversion efficiency of 1.3 × 10-4 and, for the Kα X-ray (12.7 keV), it is 8 × 10(8) photons/J with a conversion efficiency of 1.6 × 10-6. Using this X-ray source, a single-shot high-performance X-ray imaging is demonstrated.

  5. Contrast-enhanced peripheral MRA. Technique and contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Yousef W. [Dept. of Radiology, Copenhagen Univ. Hospital Bispebjerg, Bispebjerg (Denmark)], e-mail: ywnielsen@gmail.com; Thomsen, Henrik S. [Dept. of Diagnostic Radiology, Copenhagen Univ. Hospital Herlev, Herlev (Denmark)

    2012-09-15

    In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast agents. Peripheral CE-MRA is defined as an MR angiogram of the arteries from the aortic bifurcation to the feet. Advantages of CE-MRA include minimal invasiveness and lack of ionizing radiation. The basic technique employed for peripheral CE-MRA is the bolus-chase method. With this method a paramagnetic MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic field strength of the MRI system, receiver coil configuration, use of parallel imaging, contrast bolus timing technique, and k-space filling strategies. Furthermore, it is possible to optimize peripheral CE-MRA using venous compression techniques, hybrid scan protocols, time-resolved imaging, and steady-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal insufficiency. Using optimized technique and a stable MRI contrast agent, peripheral CE-MRA is a safe procedure with diagnostic accuracy close to that of conventional catheter X

  6. Perceptual Contrast Enhancement with Dynamic Range Adjustment

    Science.gov (United States)

    Zhang, Hong; Li, Yuecheng; Chen, Hao; Yuan, Ding; Sun, Mingui

    2013-01-01

    Recent years, although great efforts have been made to improve its performance, few Histogram equalization (HE) methods take human visual perception (HVP) into account explicitly. The human visual system (HVS) is more sensitive to edges than brightness. This paper proposes to take use of this nature intuitively and develops a perceptual contrast enhancement approach with dynamic range adjustment through histogram modification. The use of perceptual contrast connects the image enhancement problem with the HVS. To pre-condition the input image before the HE procedure is implemented, a perceptual contrast map (PCM) is constructed based on the modified Difference of Gaussian (DOG) algorithm. As a result, the contrast of the image is sharpened and high frequency noise is suppressed. A modified Clipped Histogram Equalization (CHE) is also developed which improves visual quality by automatically detecting the dynamic range of the image with improved perceptual contrast. Experimental results show that the new HE algorithm outperforms several state-of-the-art algorithms in improving perceptual contrast and enhancing details. In addition, the new algorithm is simple to implement, making it suitable for real-time applications. PMID:24339452

  7. Novel High Spatiotemporal Resolution Versus Standard-of-Care Dynamic Contrast-Enhanced Breast MRI: Comparison of Image Quality.

    Science.gov (United States)

    Morrison, Courtney K; Henze Bancroft, Leah C; DeMartini, Wendy B; Holmes, James H; Wang, Kang; Bosca, Ryan J; Korosec, Frank R; Strigel, Roberta M

    2017-04-01

    Currently, dynamic contrast-enhanced (DCE) breast magnetic resonance imaging (MRI) prioritizes spatial resolution over temporal resolution given the limitations of acquisition techniques. The purpose of our intrapatient study was to assess the ability of a novel high spatial and high temporal resolution DCE breast MRI method to maintain image quality compared with the clinical standard-of-care (SOC) MRI. Thirty patients, each demonstrating a focal area of enhancement (29 benign, 1 cancer) on their SOC MRI, consented to undergo a research DCE breast MRI on a second date. For the research DCE MRI, a method (DIfferential Subsampling with Cartesian Ordering [DISCO]) using pseudorandom k-space sampling, view sharing reconstruction, 2-point Dixon fat-water separation, and parallel imaging was used to produce images with an effective temporal resolution 6 times faster than the SOC MRI (27 vs 168 seconds, respectively). Both the SOC and DISCO MRI scans were acquired with matching spatial resolutions of 0.8 × 0.8 × 1.6 mm. Image quality (distortion/artifacts, resolution, fat suppression, lesion conspicuity, perceived signal-to-noise ratio, and overall image quality) was scored by 3 radiologists in a blinded reader study. Differences in image quality scores between the DISCO and SOC images were all less than 0.8 on a 10-point scale, and both methods were assessed as providing diagnostic image quality in all cases. DISCO images with the same high spatial resolution, but 6 times the effective temporal resolution as the SOC MRI scans, were produced, yielding 20 postcontrast time points with DISCO compared with 3 for the SOC MRI, over the same total time interval. DISCO provided comparable image quality compared with the SOC MRI, while also providing 6 times faster effective temporal resolution and the same high spatial resolution.

  8. Low-dose, time-resolved, contrast-enhanced 3D MR angiography in cardiac and vascular diseases: correlation to high spatial resolution 3D contrast-enhanced MRA

    Energy Technology Data Exchange (ETDEWEB)

    Krishnam, M.S. [Department of Radiological Sciences, University of California at Los Angeles, Los Angeles, CA (United States)], E-mail: mkrishnam@mednet.ucla.edu; Tomasian, A.; Lohan, D.G.; Tran, L.; Finn, J.P.; Ruehm, S.G. [Department of Radiological Sciences, University of California at Los Angeles, Los Angeles, CA (United States)

    2008-07-15

    Aim: To evaluate the effectiveness of low-dose, contrast-enhanced, time-resolved, three-dimensional (3D) magnetic resonance (MR) angiography (TR-MRA) in the assessment of various cardiac and vascular diseases, and to compare the results with high-resolution contrast-enhanced MRA (CE-MRA). Materials and Methods: Thirty consecutive patients underwent contrast-enhanced 3D TR-MRA and high spatial resolution 3D CE-MRA for evaluation of cardiac and thoracic vascular diseases at 1.5 T, and neurovascular, abdominal and peripheral vascular diseases at 3 T. Gadolinium-based contrast medium was administered at a constant dose of 5 ml for TR-MRA, and 20 ml (lower extremity 30 ml) for CE-MRA. Two readers evaluated image quality using a four-point scale (from 0 = excellent to 3 = non-diagnostic), artefacts and findings on both datasets. Interobserver variability was tested with kappa coefficient. Results: The overall image quality for TR-MRA was in the diagnostic range (median 0, range 0-1; k = 0.74). Readers demonstrated important additional dynamic information on TR-MRA in 28 of 30 patients (k = 0.84). Confident evaluation of organ perfusion (n = 23), arteriovenous malformation/fistula flow patterns (n = 7), exclusion of intra-cardiac shunts (n = 6), and assessment of stent and conduit patency (n = 5) were performed by both readers using TR-MRA. Readers demonstrated fine vascular details with higher confidence in 10 patients on CE-MRA. Using CE-MRA, Reader 1 and 2 depicted anatomical details in 6 and 5 patients, respectively, only on CE-MRA. Conclusion: Low-dose TR-MRA yields rapid and important functional and anatomical information in patients with cardiac and vascular diseases. Due to limited spatial resolution, TR-MRA is inferior to CE-MRA in demonstrating fine vascular details.

  9. Prognosis prediction of non-enhancing T2 high signal intensity lesions in glioblastoma patients after standard treatment: application of dynamic contrast-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Rihyeon; Yun, Tae Jin; Kim, Ji-Hoon; Sohn, Chul-Ho [Seoul National University Hospital, Department of Radiology, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Choi, Seung Hong [Seoul National University Hospital, Department of Radiology, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, 103 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Seoul National University, Center for Nanoparticle Research, Institute for Basic Science (IBS), Daehak-dong, Gwanak-gu, Seoul (Korea, Republic of); Seoul National University, School of Chemical and Biological Engineering, Daehak-dong, Gwanak-gu, Seoul (Korea, Republic of); Lee, Soon-Tae [Seoul National University Hospital, Department of Neurology, Seoul (Korea, Republic of); Park, Chul-Kee [Seoul National University Hospital, Department of Neurosurgery, Seoul (Korea, Republic of); Kim, Tae Min [Seoul National University Hospital, Department of Internal Medicine, Seoul (Korea, Republic of); Park, Sun-Won [Seoul National University College of Medicine, Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Park, Sung-Hye [Seoul National University Hospital, Department of Pathology, Seoul (Korea, Republic of); Kim, Il Han [Seoul National University Hospital, Department of Radiation Oncology, Seoul (Korea, Republic of)

    2017-03-15

    To identify candidate imaging biomarkers for early disease progression in glioblastoma multiforme (GBM) patients by analysis of dynamic contrast-enhanced (DCE) MR parameters of non-enhancing T2 high signal intensity (SI) lesions. Forty-nine GBM patients who had undergone preoperative DCE MR imaging and received standard treatment were retrospectively included. According to the Response Assessment in Neuro-Oncology criteria, patients were classified into progression (n = 21) or non-progression (n = 28) groups. We analysed the pharmacokinetic parameters of Ktrans, Ve and Vp within non-enhancing T2 high SI lesions of each tumour. The best percentiles of each parameter from cumulative histograms were identified by the area under the receiver operating characteristic curve (AUC) and were compared using multivariate stepwise logistic regression. For the differentiation of early disease progression, the highest AUC values were found in the 99th percentile of Ktrans (AUC 0.954), the 97th percentile of Ve (AUC 0.815) and the 94th percentile of Vp (AUC 0.786) (all p < 0.05). The 99th percentile of Ktrans was the only significant independent variable from the multivariate stepwise logistic regression (p = 0.002). We found that the Ktrans of non-enhancing T2 high SI lesions in GBM patients holds potential as a candidate prognostic marker in future prospective studies. (orig.)

  10. Postnatal Development of the Murine Notochord Remnants Quantified by High-resolution Contrast-enhanced MicroCT.

    Science.gov (United States)

    Bhalla, Sameer; Lin, Kevin H; Tang, Simon Y

    2017-10-17

    The notochord gives rise to spinal segments during development, and it becomes embedded within the nucleus pulposus of the intervertebral disc (IVD) during maturation. The disruption of the notochord band has been observed with IVD degeneration. Since the mechanical competence of the IVD relies on its structural constituents, defining the structure of the notochord during aging is critical for investigations relating to IVD function and homeostasis. The assessment and imaging of the notochord has classically relied on histological techniques, which introduces sectioning artifacts during preparation and spatial biases. Magnetic resonance imaging (MRI) does not offer sufficient resolution to discriminate the notochord from the surrounding the nucleus pulposus, especially in murine models. Current X-ray based computed tomography systems provide imaging resolutions down to the single- and sub- micron scales, and when coupled with contrast-enhancing agents, enable the high-resolution three-dimensional imaging of relatively small features. Utilizing phosphomolybdic acid to preferentially bind to collagen cationic domains, we describe the structure of the notochord remnants with aging in the lumbar IVDs of BALB/c mice. These results provide a highly quantitative and sensitive approach to monitoring the IVD during postnatal development.

  11. Contrast enhanced ultrasound of sentinel lymph nodes

    Directory of Open Access Journals (Sweden)

    XinWu Cui

    2013-03-01

    Full Text Available Sentinel lymph nodes are the first lymph nodes in the region that receive lymphatic drainage from a primary tumor. The detection or exclusion of sentinel lymph node micrometastases is critical in the staging of cancer, especially breast cancer and melanoma because it directly affects patient’s prognosis and surgical management. Currently, intraoperative sentinel lymph node biopsies using blue dye and radioisotopes are the method of choice for the detection of sentinel lymph node with high identification rate. In contrast, conventional ultrasound is not capable of detecting sentinel lymph nodes in most cases. Contrast enhanced ultrasound with contrast specific imaging modes has been used for the evaluation and diagnostic work-up of peripherally located suspected lymphadenopathy. The method allows for real-time analysis of all vascular phases and the visualization of intranodal focal “avascular” areas that represent necrosis or deposits of neoplastic cells. In recent years, a number of animal and human studies showed that contrast enhanced ultrasound can be also used for the detection of sentinel lymph node, and may become a potential application in clinical routine. Several contrast agents have been used in those studies, including albumin solution, hydroxyethylated starch, SonoVue®, Sonazoid® and Definity®. This review summarizes the current knowledge about the use of ultrasound techniques in detection and evaluation of sentinel lymph node.

  12. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

    Reddy, Nischita K; Ioncica, Ana Maria; Saftoiu, Adrian

    2011-01-01

    Contrast agents are increasingly being used to characterize the vasculature in an organ of interest, to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures. We review the mechanisms of action of first, second and third generation contrast...... cancers and visualization of the portal venous system and esophageal varices. In addition, contrast agents can be used to differentiate pancreatic lesions. The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies. The sensitivity of power Doppler...... and monitor the efficacy of antiangiogenic agents, to assist targeted drug delivery and allow molecular imaging....

  13. {sup 18}F-FDG PET/contrast enhanced CT in the standard surveillance of high risk colorectal cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez Londoño, Germán Andrés, E-mail: gjimenez91@yahoo.com [Department of Nuclear Medicine, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); García Vicente, Ana María [Department of Nuclear Medicine, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Sánchez Pérez, Victoria [Department of Oncology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Jiménez Aragón, Fátima [Department of Radiology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); León Martin, Alberto [Investigation Unit, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Cano Cano, Juana María [Department of Oncology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Domínguez Ferreras, Esther [Department of Radiology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Gómez López, Ober Van [Department of Nuclear Medicine, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Espinosa Arranz, Javier [Department of Oncology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Soriano Castrejón, Ángel María [Department of Nuclear Medicine, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain)

    2014-12-15

    Highlights: • We assessed the accuracy of FDG-PET/contrast enhanced CT (FDG-PET/ceCT) in the detection of unsuspected recurrence of colorectal cancer. In regard to our knowledge, no previous experience has been reported about the combined acquisition and interpretation of a FDG-PET/ceCT in the surveillance of colorectal cancer. • We designed a prospective study and performed an individual and combined assessment of both techniques (PET and ceCT), in a patient-based analysis and a lesion-based analysis. • The value of PET and ceCT was found to be similar in the detection of unsuspected recurrence of CRC in a patient-based analysis. The most interesting of our result, is that the combined assessment of PET/ceCT improves the accuracy in the lesion-based analysis. - Abstract: Objective: To assess the accuracy of FDG-PET/contrast enhanced CT (FDG-PET/ceCT) in the detection of unsuspected recurrence of colorectal cancer (CRC) in patients with high risk of relapse. Methods: Thirty-three patients (14 females and 19 males, mean age: 62, range: 41–78), with CRC in complete remission, were prospectively included. All patients underwent FDG-PET/ceCT (58 studies). FDG-PET/ceCT was requested in the surveillance setting, and performed following a standardized protocol. A portal venous phase CT scan was performed after the injection of iodinated contrast agent. An individual and combined assessment of both techniques (PET and ceCT) was performed. Concordant and discordant findings of PET, ceCT and FDG-PET/ceCT were compared in a patient-based and a lesion-based analysis. The final diagnosis, recurrence or disease free status (DFS), were established by histopathology or clinical/radiological follow-up of at least 6 months. Results: Seven out of 33 patients had a confirmed recurrence and the rest of patients had a DFS. In a patient-based analysis the sensitivity and specificity of PET, ceCT and PET/ceCT was of 86% and 88%, 86% and 92%, 86% and 85%, respectively. Attending to

  14. Prognostic value of preoperative dynamic contrast-enhanced MRI perfusion parameters for high-grade glioma patients

    Energy Technology Data Exchange (ETDEWEB)

    Ulyte, Agne [Vilnius University, Faculty of Medicine, Vilnius (Lithuania); Katsaros, Vasileios K. [General Anticancer and Oncological Hospital ' ' St. Savvas' ' , Department of Advanced Imaging Modalities - CT and MRI, Athens (Greece); University of Athens, Department of Neurosurgery, Evangelismos Hospital, Athens (Greece); Liouta, Evangelia; Stranjalis, Georgios [University of Athens, Department of Neurosurgery, Evangelismos Hospital, Athens (Greece); Boskos, Christos [University of Athens, Department of Neurosurgery, Evangelismos Hospital, Athens (Greece); General Anticancer and Oncological Hospital ' ' St. Savvas' ' , Department of Radiation Oncology, Athens (Greece); Papanikolaou, Nickolas [Champalimaud Foundation, Department of Radiology, Centre for the Unknown, Lisbon (Portugal); Usinskiene, Jurgita [National Cancer Institute, Vilnius (Lithuania); Affidea Lietuva, Vilnius (Lithuania); Bisdas, Sotirios [University College London Hospitals, Department of Neuroradiology, The National Hospital for Neurology and Neurosurgery, London (United Kingdom)

    2016-12-15

    The prognostic value of the dynamic contrast-enhanced (DCE) MRI perfusion and its histogram analysis-derived metrics is not well established for high-grade glioma (HGG) patients. The aim of this prospective study was to investigate DCE perfusion transfer coefficient (K{sup trans}), vascular plasma volume fraction (v{sub p}), extracellular volume fraction (v{sub e}), reverse transfer constant (k{sub ep}), and initial area under gadolinium concentration time curve (IAUGC) as predictors of progression-free (PFS) and overall survival (OS) in HGG patients. Sixty-nine patients with suspected anaplastic astrocytoma or glioblastoma underwent preoperative DCE-MRI scans. DCE perfusion whole tumor region histogram parameters, clinical details, and PFS and OS data were obtained. Univariate, multivariate, and Kaplan-Meier survival analyses were conducted. Receiver operating characteristic (ROC) curve analysis was employed to identify perfusion parameters with the best differentiation performance. On univariate analysis, v{sub e} and skewness of v{sub p} had significant negative impacts, while k{sub ep} had significant positive impact on OS (P < 0.05). v{sub e} was also a negative predictor of PFS (P < 0.05). Patients with lower v{sub e} and IAUGC had longer median PFS and OS on Kaplan-Meier analysis (P < 0.05). K{sup trans} and v{sub e} could also differentiate grade III from IV gliomas (area under the curve 0.819 and 0.791, respectively). High v{sub e} is a consistent predictor of worse PFS and OS in HGG glioma patients. v{sub p} skewness and k{sub ep} are also predictive for OS. K{sup trans} and v{sub e} demonstrated the best diagnostic performance for differentiating grade III from IV gliomas. (orig.)

  15. Contrast enhancement versus vasculature of uterine tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kormano, M.; Kiilholma, P.; Groenroos, M.

    1984-05-01

    The relative contrast enhancement of normal myometrium and small or medium size uterine fibroids and clinical stage I endometrial carcinomas were correlated to their microangiographically demonstrable vascularity. In four cases small uterine fibroids showed contrast enhancement equal to normal myometrium, independent of their vascularity in microangiography. In five, endometrial carcinomas contrast enhancement was always below that of the surrounding myometrium in CT. Intratumour vasculature showed great variability in microangiography. No correlation between the topographic variations in the arrangement or density of tumour blood vessels and the degree of contrast enhancement was found. Contrast enhancement of small uterine fibroids was greater than that of small adenocarcinomas. More contrast material accumulates into the extravascular space of the smooth muscle tissue of the fibroid than into the extravascular space of endometrial carcinoma.

  16. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

    Reddy, Nischita K; Ioncică, Ana Maria; Săftoiu, Adrian

    2011-01-01

    cancers and visualization of the portal venous system and esophageal varices. In addition, contrast agents can be used to differentiate pancreatic lesions. The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies. The sensitivity of power Doppler...

  17. Contrast-enhanced and targeted ultrasound

    Science.gov (United States)

    Postema, Michiel; Gilja, Odd Helge

    2011-01-01

    Ultrasonic imaging is becoming the most popular medical imaging modality, owing to the low price per examination and its safety. However, blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies. For perfusion imaging, markers have been designed to enhance the contrast in B-mode imaging. These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells. In this review, the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described. Furthermore, an outline of clinical imaging applications of contrast-enhanced ultrasound is given. It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition, and how these phenomena may be utilized in ultrasonic imaging. Aided by high-speed photography, our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques. More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves, and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs. These are beginning to be accepted into clinical practice. In the long term, targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested. PMID:21218081

  18. Contrast-enhanced and targeted ultrasound.

    Science.gov (United States)

    Postema, Michiel; Gilja, Odd Helge

    2011-01-07

    Ultrasonic imaging is becoming the most popular medical imaging modality, owing to the low price per examination and its safety. However, blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies. For perfusion imaging, markers have been designed to enhance the contrast in B-mode imaging. These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells. In this review, the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described. Furthermore, an outline of clinical imaging applications of contrast-enhanced ultrasound is given. It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition, and how these phenomena may be utilized in ultrasonic imaging. Aided by high-speed photography, our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques. More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves, and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs. These are beginning to be accepted into clinical practice. In the long term, targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested.

  19. Contrast-enhanced spectral mammography (CESM) versus MRI in the high-risk screening setting: patient preferences and attitudes.

    Science.gov (United States)

    Phillips, Jordana; Miller, Matthew M; Mehta, Tejas S; Fein-Zachary, Valerie; Nathanson, Audrey; Hori, Wendy; Monahan-Earley, Rita; Slanetz, Priscilla J

    Our study evaluates patient preferences toward screening CESM versus MRI. As part of a prospective study, high-risk patients had breast MRI and CESM. Patients completed an anonymous survey to evaluate preferences regarding the two modalities. 88% of participants completed the survey. 79% preferred CESM over MRI if the exams had equal sensitivity. 89% would be comfortable receiving contrast as part of an annual screening test. High-risk populations may accept CESM as a screening exam and may prefer it over screening MRI if ongoing trials demonstrate screening CESM to be clinically non-inferior MRI. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Dual-energy contrast-enhanced spectral mammography (CESM).

    Science.gov (United States)

    Daniaux, Martin; De Zordo, Tobias; Santner, Wolfram; Amort, Birgit; Koppelstätter, Florian; Jaschke, Werner; Dromain, Clarisse; Oberaigner, Willi; Hubalek, Michael; Marth, Christian

    2015-10-01

    Dual-energy contrast-enhanced mammography is one of the latest developments in breast care. Imaging with contrast agents in breast cancer was already known from previous magnetic resonance imaging and computed tomography studies. However, high costs, limited availability-or high radiation dose-led to the development of contrast-enhanced spectral mammography (CESM). We reviewed the current literature, present our experience, discuss the advantages and drawbacks of CESM and look at the future of this innovative technique.

  1. Quantitative contrast-enhanced mammography for contrast medium kinetics studies.

    Science.gov (United States)

    Arvanitis, C D; Speller, R

    2009-10-21

    Quantitative contrast-enhanced mammography, based on a dual-energy approach, aims to extract quantitative and temporal information of the tumour enhancement after administration of iodinated vascular contrast media. Simulations using analytical expressions and optimization of critical parameters essential for the development of quantitative contrast-enhanced mammography are presented. The procedure has been experimentally evaluated using a tissue-equivalent phantom and an amorphous silicon active matrix flat panel imager. The x-ray beams were produced by a tungsten target tube and spectrally shaped using readily available materials. Measurement of iodine projected thickness in mg cm(-2) has been performed. The effect of beam hardening does not introduce nonlinearities in the measurement of iodine projected thickness for values of thicknesses found in clinical investigations. However, scattered radiation introduces significant deviations from slope equal to unity when compared with the actual iodine projected thickness. Scatter correction before the analysis of the dual-energy images provides accurate iodine projected thickness measurements. At 10% of the exposure used in clinical mammography, signal-to-noise ratios in excess of 5 were achieved for iodine projected thicknesses less than 3 mg cm(-2) within a 4 cm thick phantom. For the extraction of temporal information, a limited number of low-dose images were used with the phantom incorporating a flow of iodinated contrast medium. The results suggest that spatial and temporal information of iodinated contrast media can be used to indirectly measure the tumour microvessel density and determine its uptake and washout from breast tumours. The proposed method can significantly improve tumour detection in dense breasts. Its application to perform in situ x-ray biopsy and assessment of the oncolytic effect of anticancer agents is foreseeable.

  2. Supra-aortic low-dose contrast-enhanced time-resolved magnetic resonance (MR) angiography at 3 T: comparison with time-of-flight MR angiography and high-resolution contrast-enhanced MR angiography.

    Science.gov (United States)

    Lee, Youn-Joo; Kim, Bum-soo; Koo, Ja-Sung; Kim, Bom-Yi; Jang, Jinhee; Choi, Hyun Seok; Jung, So-Lyung; Ahn, Kook-Jin

    2015-06-01

    Low-dose, time-resolved, contrast-enhanced, magnetic resonance angiography (TR-CEMRA) has been described previously; however, a comparative study between low dose TR-CEMRA and time-of-flight MRA (TOF-MRA) in the diagnosis of supra-aortic arterial stenosis has not yet been published. To demonstrate the feasibility and effectiveness of low-dose TR-CEMRA compared with TOF-MRA, using high-resolution contrast-enhanced MRA (HR-CEMRA) as the reference standard. This prospective study consisted of 30 consecutive patients. All patients underwent TOF-MRA of the neck and circle of Willis and supra-aortic HR-CEMRA, followed by supra-aortic low-dose TR-CEMRA. Gadoterate meglumine (Gd-DOTA, Dotarem(®), Guerbet, Roissy CdG Cedex, France) was injected at a dose of 0.1 mmol/kg for HR-CEMRA, followed by a 0.03 mmol/kg bolus for low-dose TR-CEMRA. Three readers evaluated the assessibility and image quality, and then two readers classified each stenosis into the following categories: normal (0-30%), mild stenosis (31-50%), moderate (51-70%), severe (71-99%), and occlusion. TR-CEMRA and HR-CEMRA showed a greater number of assessable arterial segments than TOF-MRA (P < 0.01). For TR-CEMRA, 29 cases showed within or better than the diagnostic range, whereas all 30 cases were in the diagnostic range for TOF-MRA and HR-CEMRA. For evaluation of stenosis in a total of 743 arterial segments, both TR-CEMRA and TOF-MRA results agreed with those of HR-CEMRA in 729 segments (98.1%), with excellent inter-observer agreement of TR-CEMRA; stenosis was overestimated in nine segments (1.2%) and underestimated in five segments (0.7%). For diagnosis of stenosis using 30% as the cut-off value on HR-CEMRA, the sensitivity and specificity were 88.2% and 99.3%, respectively, for the TR-CEMRA procedure, versus 94.1% and 99.6%, respectively, for TOF-MRA. Low-dose TR-CEMRA is feasible and effective in the diagnosis of supra-aortic arterial stenosis, and could be more useful option than TOF-MRA. © The

  3. High-Spatial- and High-Temporal-Resolution Dynamic Contrast-enhanced MR Breast Imaging with Sweep Imaging with Fourier Transformation: A Pilot Study

    Science.gov (United States)

    Benson, John C.; Idiyatullin, Djaudat; Snyder, Angela L.; Snyder, Carl J.; Hutter, Diane; Everson, Lenore I.; Eberly, Lynn E.; Nelson, Michael T.; Garwood, Michael

    2015-01-01

    Purpose To report the results of sweep imaging with Fourier transformation (SWIFT) magnetic resonance (MR) imaging for diagnostic breast imaging. Materials and Methods Informed consent was obtained from all participants under one of two institutional review board–approved, HIPAA-compliant protocols. Twelve female patients (age range, 19–54 years; mean age, 41.2 years) and eight normal control subjects (age range, 22–56 years; mean age, 43.2 years) enrolled and completed the study from January 28, 2011, to March 5, 2013. Patients had previous lesions that were Breast Imaging Reporting and Data System 4 and 5 based on mammography and/or ultrasonographic imaging. Contrast-enhanced SWIFT imaging was completed by using a 4-T research MR imaging system. Noncontrast studies were completed in the normal control subjects. One of two sized single-breast SWIFT-compatible transceiver coils was used for nine patients and five controls. Three patients and five control subjects used a SWIFT-compatible dual breast coil. Temporal resolution was 5.9–7.5 seconds. Spatial resolution was 1.00 mm isotropic, with later examinations at 0.67 mm isotropic, and dual breast at 1.00 mm or 0.75 mm isotropic resolution. Results Two nonblinded breast radiologists reported SWIFT image findings of normal breast tissue, benign fibroadenomas (six of six lesions), and malignant lesions (10 of 12 lesions) concordant with other imaging modalities and pathologic reports. Two lesions in two patients were not visualized because of coil field of view. The images yielded by SWIFT showed the presence and extent of known breast lesions. Conclusion The SWIFT technique could become an important addition to breast imaging modalities because it provides high spatial resolution at all points during the dynamic contrast-enhanced examination. © RSNA, 2014 PMID:25247405

  4. Contrast-enhanced harmonic endoscopic ultrasound

    DEFF Research Database (Denmark)

    Săftoiu, A; Dietrich, C F; Vilmann, P

    2012-01-01

    Second-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS) for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, and improving staging and guidance of therapeutic procedures. Although...... contrast-enhanced harmonic EUS based on a very low mechanical index (0.08 - 0.12). Quantification techniques based on dynamic contrast-enhanced ultrasound have been recommended for perfusion imaging and monitoring of anti-angiogenic treatment, mainly based on time-intensity curve analysis. Most...

  5. Contrast-enhanced MR mammography for evaluation of the contralateral breast in patients with diagnosed unilateral breast cancer or high-risk lesions.

    Science.gov (United States)

    Pediconi, Federica; Catalano, Carlo; Roselli, Antonella; Padula, Simona; Altomari, Fiorella; Moriconi, Enrica; Pronio, Anna Maria; Kirchin, Miles A; Passariello, Roberto

    2007-06-01

    To prospectively evaluate accuracy of gadobenate dimeglumine-enhanced magnetic resonance (MR) mammography for depiction of synchronous contralateral breast cancer in patients with newly diagnosed unilateral breast cancer or high-risk lesions, with histologic analysis or follow-up as reference. The study had ethics committee approval; all patients provided written informed consent. One hundred eighteen consecutive women (mean age, 52 years) with unilateral breast cancer or high-risk lesions and negative findings in the contralateral breast at physical examination, ultrasonography, and conventional mammography underwent gadobenate dimeglumine-enhanced 1.5-T MR mammography. Transverse three-dimensional T1-weighted gradient-echo images were acquired before and at 0, 2, 4, 6, and 8 minutes after gadobenate dimeglumine administration (0.1 mmol per kilogram body weight). Breast Imaging Reporting and Data System (BI-RADS) was used to categorize breast density and the level of suspicion for malignant contralateral breast lesions. Results were compared with histologic findings. Sensitivity, specificity, accuracy, and positive and negative predictive values for contrast-enhanced MR mammography were evaluated. Contrast-enhanced MR mammography revealed contralateral lesions in 28 (24%) of 118 patients. Twenty-four lesions were detected in patients with dense breasts (BI-RADS breast density category III or IV). Lesions in eight (29%) of 28 patients were BI-RADS category 4; patients underwent biopsy. Lesions in 20 (71%) patients were BI-RADS category 5; patients underwent surgery. At histologic analysis, 22 lesions were confirmed as malignant; six lesions were fibroadenomas. No false-negative lesions were detected; none of the fibroadenomas were BI-RADS category 5. The sensitivity, specificity, accuracy, and positive and negative predictive values of contrast-enhanced MR mammography for depiction of malignant or high-risk contralateral lesions were 100%, 94%, 95%, 79%, and 100

  6. Evaluation of contrast-enhanced digital mammography.

    Science.gov (United States)

    Diekmann, Felix; Freyer, Martin; Diekmann, Susanne; Fallenberg, Eva M; Fischer, Thomas; Bick, Ulrich; Pöllinger, Alexander

    2011-04-01

    The goal of this prospective study was to evaluate the possible diagnostic benefits of contrast-enhanced digital mammography (CEDM) over conventional mammography. Our analysis included data from 70 patients with a total of 80 lesions (30 malignant and 50 benign). A series of contrast-enhanced images was acquired from each patient using a modified imaging system (GE Senographe 2000D with copper filter) suitable for displaying iodine contrast medium. After the mask image had been taken, the contrast medium was administered using a dosage of 1ml/kg body weight at a rate of 4ml/s. Three contrast-enhanced images in the cranio-caudal projection plane were then captured at intervals of 60s. The mask image was logarithmically subtracted from the contrast-enhanced images. We performed a ROC analysis of diagnostic quality with three readers. On average, 5.66 more malignant lesions were detected with the addition of digital dynamic contrast mammography versus conventional mammography alone. The sensitivity was increased from an average of 0.43 in conventional mammography to an average of 0.62 with contrast mammography. Even in dense breast parenchyma, the sensitivity increased from an average of 0.35-0.59. In the multi-reader-ROC analyses of all readers, the differences in the AUC with p=0.02 (BI-RADS) proved statistically significant in all cases. The Wilcoxon test showed that Readers I and II primarily used the CEDM to upgrade enhancing lesions to a higher BI-RADS category or a higher probability of malignancy. These two readers benefited most from the CEDM in the ROC analysis. Overall, we conclude that the addition of dynamic digital subtraction mammography to conventional mammography can significantly improve diagnostic quality. The increased sensitivity is particularly pronounced in the case of dense breast tissue. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  7. 3.0 Tesla high spatial resolution contrast-enhanced magnetic resonance angiography (CE-MRA) of the pulmonary circulation: initial experience with a 32-channel phased array coil using a high relaxivity contrast agent.

    Science.gov (United States)

    Nael, Kambiz; Fenchel, Michael; Krishnam, Mayil; Finn, J Paul; Laub, Gerhard; Ruehm, Stefan G

    2007-06-01

    To evaluate the technical feasibility of high spatial resolution contrast-enhanced magnetic resonance angiography (CE-MRA) with highly accelerated parallel acquisition at 3.0 T using a 32-channel phased array coil, and a high relaxivity contrast agent. Ten adult healthy volunteers (5 men, 5 women, aged 21-66 years) underwent high spatial resolution CE-MRA of the pulmonary circulation. Imaging was performed at 3 T using a 32-channel phase array coil. After intravenous injection of 1 mL of gadobenate dimeglumine (Gd-BOPTA) at 1.5 mL/s, a timing bolus was used to measure the transit time from the arm vein to the main pulmonary artery. Subsequently following intravenous injection of 0.1 mmol/kg of Gd-BOPTA at the same rate, isotropic high spatial resolution data sets (1 x 1 x 1 mm3) CE-MRA of the entire pulmonary circulation were acquired using a fast gradient-recalled echo sequence (TR/TE 3/1.2 milliseconds, FA 18 degrees) and highly accelerated parallel acquisition (GRAPPA x 6) during a 20-second breath hold. The presence of artifact, noise, and image quality of the pulmonary arterial segments were evaluated independently by 2 radiologists. Phantom measurements were performed to assess the signal-to-noise ratio (SNR). Statistical analysis of data was performed by using Wilcoxon rank sum test and 2-sample Student t test. The interobserver variability was tested by kappa coefficient. All studies were of diagnostic quality as determined by both observers. The pulmonary arteries were routinely identified up to fifth-order branches, with definition in the diagnostic range and excellent interobserver agreement (kappa = 0.84, 95% confidence interval 0.77-0.90). Phantom measurements showed significantly lower SNR (P < 0.01) using GRAPPA (17.3 +/- 18.8) compared with measurements without parallel acquisition (58 +/- 49.4). The described 3 T CE-MRA protocol in addition to high T1 relaxivity of Gd-BOPTA provides sufficient SNR to support highly accelerated parallel acquisition

  8. High-resolution blood-pool-contrast-enhanced MR angiography in glioblastoma: tumor-associated neovascularization as a biomarker for patient survival. A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Puig, Josep; Blasco, Gerard; Remollo, Sebastian; Hernandez, David; Pedraza, Salvador [Hospital Universitari Dr Josep Trueta, Research Unit of Diagnostic Imaging Institute (IDI), Department of Radiology [Girona Biomedical Research Institute] IDIBGI, Girona (Spain); Daunis-i-Estadella, Josep; Mateu, Gloria [University of Girona, Department of Computer Science, Applied Mathematics and Statistics, Girona (Spain); Alberich-Bayarri, Angel [La Fe Polytechnics and University Hospital, Biomedical Imaging Research Group (GIBI230), La Fe Health Research Institute, Valencia (Spain); Essig, Marco [University of Manitoba, Department of Radiology, Winnipeg (Canada); Jain, Rajan [NYU School of Medicine, Division of Neuroradiology, Department of Radiology, New York, NY (United States); Puigdemont, Montserrat [Hospital Universitari Dr Josep Trueta, Catalan Institute of Oncology (ICO), Hospital Cancer Registry, Girona (Spain); Sanchez-Gonzalez, Javier [Philips Healthcare Iberica, Madrid (Spain); Wintermark, Max [Stanford University, Department of Radiology, Neuroradiology Division, Palo Alto, CA (United States)

    2016-01-15

    The objective of the study was to determine whether tumor-associated neovascularization on high-resolution gadofosveset-enhanced magnetic resonance angiography (MRA) is a useful biomarker for predicting survival in patients with newly diagnosed glioblastomas. Before treatment, 35 patients (25 men; mean age, 64 ± 14 years) with glioblastoma underwent MRI including first-pass dynamic susceptibility contrast (DSC) perfusion and post-contrast T1WI sequences with gadobutrol (0.1 mmol/kg) and, 48 h later, high-resolution MRA with gadofosveset (0.03 mmol/kg). Volumes of interest for contrast-enhancing lesion (CEL), non-CEL, and contralateral normal-appearing white matter were obtained, and DSC perfusion and DWI parameters were evaluated. Prognostic factors were assessed by Kaplan-Meier survival and Cox proportional hazards model. Eighteen (51.42 %) glioblastomas were hypervascular on high-resolution MRA. Hypervascular glioblastomas were associated with higher CEL volume and lower Karnofsky score. Median survival rates for patients with hypovascular and hypervascular glioblastomas treated with surgery, radiotherapy, and chemotherapy were 15 and 9.75 months, respectively (P < 0.001). Tumor-associated neovascularization was the best predictor of survival at 5.25 months (AUC = 0.794, 81.2 % sensitivity, 77.8 % specificity, 76.5 % positive predictive value, 82.4 % negative predictive value) and yielded the highest hazard ratio (P < 0.001). Tumor-associated neovascularization detected on high-resolution blood-pool-contrast-enhanced MRA of newly diagnosed glioblastoma seems to be a useful biomarker that correlates with worse survival. (orig.)

  9. Post-traumatic contrast enhancing brain lesion

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Jung; Kim, Hyun Sook; Jeong, Min Sun; Kim, Deok Ryeong; Cho, Young Kwon; Choi, Yun Sun [Eulji Hospital, Eulji University College of Medicine, Seoul (Korea, Republic of)

    2014-10-15

    Only a few studies have been reported on the MR contrast enhancement and the apparent diffusion coefficient (ADC) findings of the post-traumatic lesion of the brain. We report a case of the venous ischemia in the left frontal lobe observed in the MRI obtained one day after the incidence of trauma. Considering the presented slight increase in the ADC, the vasogenic edema was thought to be the major mechanism of the venous ischemia and excitotoxic injury. In spite of a slight increase in the ADC, the hyperintensity in the diffusion weighted imaging and contrast-enhanced areas eventually changed into hemorrhagic lesions.

  10. Clinical evaluation of contrast-enhanced digital mammography and contrast enhanced tomosynthesis--Comparison to contrast-enhanced breast MRI.

    Science.gov (United States)

    Chou, Chen-Pin; Lewin, John M; Chiang, Chia-Ling; Hung, Bao-Hui; Yang, Tsung-Lung; Huang, Jer-Shyung; Liao, Jia-Bin; Pan, Huay-Ben

    2015-12-01

    To compare the diagnostic accuracy of contrast-enhanced digital mammography (CEDM) and contrast-enhanced tomosynthesis (CET) to dynamic contrast enhanced breast MRI (DCE-MRI) using a multireader-multicase study. Institutional review board approval and informed consents were obtained. Total 185 patients (mean age 51.3) with BI-RADS 4 or 5 lesions were evaluated before biopsy with mammography, tomosynthesis, CEDM, CET and DCE-MRI. Mediolateral-oblique and cranio-caudal views of the target breast CEDM and CET were acquired at 2 and 4 min after contrast agent injection. A mediolateral-oblique view of the non-target breast was taken at 6 min. Each lesion was scored with forced BI-RADS categories by three readers. Each reader interpreted lesions in the following order: mammography, tomosynthesis, CEDM, CET, and DCE-MRI during a single reading session. Histology showed 81 cancers and 144 benign lesions in the study. Of the 81 malignant lesions, 44% (36/81) were invasive and 56% (45/81) were non-invasive. Areas under the ROC curve, averaged for the 3 readers, were as follows: 0.897 for DCE-MRI, 0.892 for CET, 0.878 for CEDM, 0.784 for tomosynthesis and 0.740 for mammography. Significant differences in AUC were found between the group of contrast enhanced modalities (CEDM, CET, DCE-MRI) and the unenhanced modalities (all p0.05). CET and CEDM may be considered as an alternative modality to MRI for following up women with abnormal mammography. All three contrast modalities were superior in accuracy to conventional digital mammography with or without tomosynthesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Renal oncocytoma: contrast-enhanced sonographic features.

    Science.gov (United States)

    Wu, Ying; Du, Lianfang; Li, Fan; Zhang, Huiping; Cai, Yingyu; Jia, Xiao

    2013-03-01

    The purpose of this study was to illustrate the features of renal oncocytoma on contrast-enhanced sonography. Five cases of surgical pathologically proven renal oncocytoma were retrospectively reviewed and analyzed in this study. The 5 patients studied included 3 men and 2 women with a mean age of 52.3 years (range, 32-66 years). All patients underwent conventional and contrast-enhanced sonographic examinations before surgery. The sonographic features, enhancement pattern, and dynamic perfusion change of the tumors and renal parenchyma in vascular phases were evaluated and compared to computed tomography. On grayscale sonography, renal oncocytomas appeared as solitary hypoechoic or isoechoic masses originating from the renal cortex measuring 2 to 6 cm with a well-defined margin. Color Doppler flow imaging showed rich blood flow signals in the periphery and striplike blood flow signals within the masses. On contrast-enhanced sonography, the features of these tumors included early enhancement, hyperenhancement, and fast wash-out compared to the adjacent renal cortex. There were irregular nonenhanced areas seen in the center of the masses (n = 3) and nonenhanced thin rims seen in the periphery (n = 5). Macroscopically, the well-marginated tumors were yellowish brown with a tender texture and were located in the renal cortex. Central irregularly shaped fibrous scars were seen in 3 tumors, consistent with nonenhanced areas on contrast-enhanced imaging. Contrast-enhanced sonography can provide valuable hemodynamic information on renal oncocytoma, which may help in making a differential diagnosis of this benign renal tumor in clinical practice.

  12. Lack of nephrotoxicity of gadopentetate dimeglumine-enhanced non-vascular MRI and MRI without contrast agent in patients at high-risk for acute kidney injury.

    Science.gov (United States)

    Gok Oguz, Ebru; Kiykim, Ahmet; Turgutalp, Kenan; Olmaz, Refik; Ozhan, Onur; Muslu, Necati; Horoz, Mehmet; Bardak, Simge; Sungur, Mehmet Ali

    2013-11-06

    Gadolinium chelates (GCs) have been traditionally considered as non-nephrotoxic magnetic resonance imaging (MRI) contrast materials. However, it has been suggested in some recent articles that GCs may have a nephrotoxic potential, but most of these reports are retrospective. However, the evaluated contrast agents, their doses, and the tests used to determine the kidney function were not consistent across studies. We aimed to investigate the effect of magnetic field and an MRI contrast agent, gadopentetate dimeglumine (GD), on renal functions in patients at high risk for acute kidney injury (AKI). We designed a prospective case-control study with 2 age- and sex-matched groups of patients at high-risk for AKI (n=72 for each group). Patients in Group 1 received a fixed dose of (0.2 mmol/kg) GD-enhanced non-vascular MRI and patients in Group 2 received MRI without GD. Before the MRI and at 6, 24, 72, and 168 hours after the MRI, biochemical tests, estimated glomerular filtration rate (eGFR), albumin/creatinine ratio in spot urine, and early AKI biomarkers (cystatin C, N-Acetyl-Glucosaminidase [NAG], Neutrophil gelatinase-associated lipocalin [NGAL]) were measured. Serum creatinine, albumin/creatinine ratio, and eGFR were not different between Group 1 and 2 (p>0.05). There were no significant changes in renal function tests and AKI biomarkers (∆serum creatinine, ∆albumin/creatinine ratio, ∆GFR, ∆cystatin C, ∆NAG, and ∆NGAL) for either groups 6, 24, 72, and 168 hours after the procedures (p>0.05). MRI without contrast agent and non-vascular contrast-enhanced (GD, 0.2 mmol/kg) MRI are not nephrotoxic procedures for patients at high risk for AKI.

  13. Dynamic Contrast-Enhanced Magnetic Resonance Enterography and Dynamic Contrast-Enhanced Ultrasonography in Crohn's Disease

    DEFF Research Database (Denmark)

    Wilkens, Rune; Peters, David A; Nielsen, Agnete Hedemann

    2017-01-01

    Purpose e Cross-sectional imaging methods are important for objective evaluationof small intestinal inflammationinCrohn'sdisease(CD).The primary aim was to compare relative parameters of intestinal perfusion between contrast-enhanced ultrasonography (CEUS) and dynamic contrast-enhanced magnetic...

  14. Characterization of Pure Ductal Carcinoma In Situ on Dynamic Contrast-Enhanced MR Imaging: Do Nonhigh Grade and High Grade Show Different Imaging Features?

    Directory of Open Access Journals (Sweden)

    Siwa Chan

    2010-01-01

    Full Text Available To characterize imaging features of pure DCIS on dynamic contrast-enhanced MR imaging (DCE-MRI, 31 consecutive patients (37-81 years old, mean 56, including 2 Grade I, 16 Grade II, and 13 Grade III, were studied. MR images were reviewed retrospectively and the morphological appearances and kinetic features of breast lesions were categorized according to the ACR BI-RADS breast MRI lexicon. DCE-MRI was a sensitive imaging modality in detecting pure DCIS. MR imaging showed enhancing lesions in 29/31 (94% cases. Pure DCIS appeared as mass type or non-mass lesions on MRI with nearly equal frequency. The 29 MR detected lesions include 15 mass lesions (52%, and 14 lesions showing non-mass-like lesions (48%. For the mass lesions, the most frequent presentations were irregular shape (50%, irregular margin (50% and heterogeneous enhancement (67%. For the non-mass-like lesions, the clumped internal enhancement pattern was the dominate feature, seen in 9/14 cases (64%. Regarding enhancement kinetic curve, 21/29 (78% lesions showed suspicious malignant type kinetics. No significant difference was found in morphology (>.05, tumor size (P = 0.21, and kinetic characteristics (=.38 between non-high grade (I+II and high-grade (III pure DCIS.

  15. Integration of myocardial scar identified by preoperative delayed contrast-enhanced MRI into a high-resolution mapping system for planning and guidance of VT ablation procedures

    Science.gov (United States)

    Rettmann, M. E.; Suzuki, A.; Wang, S.; Pottinger, N.; Arter, J.; Netzer, A.; Parker, K.; Viker, K.; Packer, D. L.

    2017-03-01

    Myocardial scarring creates a substrate for reentrant circuits which can lead to ventricular tachycardia. In ventricular catheter ablation therapy, regions of myocardial scarring are targeted to interrupt arrhythmic electrical pathways. Low voltage regions are a surrogate for myocardial scar and are identified by generating an electro anatomic map at the start of the procedure. Recent efforts have focussed on integration of preoperative scar information generated from delayed contrast-enhanced MR imaging to augment intraprocedural information. In this work, we describe an initial feasibility study of integration of a preoperative MRI derived scar maps into a high-resolution mapping system to improve planning and guidance of VT ablation procedures.

  16. Dynamic contrast enhanced ultrasound for therapy monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, John M. [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Williams, Ross [Imaging Research, Sunnybrook Research Institute, Toronto, ON (Canada); Tremblay-Darveau, Charles; Sheeran, Paul S. [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Milot, Laurent [Department of Medical Imaging, University of Toronto, Toronto, ON (Canada); Bjarnason, Georg A. [Department of Medical Oncology, University of Toronto, and Sunnybrook Odette Cancer Centre, Toronto, ON (Canada); Burns, Peter N., E-mail: burns@sri.utoronto.ca [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Imaging Research, Sunnybrook Research Institute, Toronto, ON (Canada); Department of Medical Imaging, University of Toronto, Toronto, ON (Canada)

    2015-09-15

    Quantitative imaging is a crucial component of the assessment of therapies that target the vasculature of angiogenic or inflamed tissue. Dynamic contrast-enhanced ultrasound (DCE-US) using microbubble contrast offers the advantages of being sensitive to perfusion, non-invasive, cost effective and well suited to repeated use at the bedside. Uniquely, it employs an agent that is truly intravascular. This papers reviews the principles and methodology of DCE-US, especially as applied to anti-angiogenic cancer therapies. Reproducibility is an important attribute of such a monitoring method: results are discussed. More recent technical advances in parametric and 3D DCE-US imaging are also summarised and illustrated.

  17. Intra-observer agreement in single and joint double readings of contrast-enhanced breast MRI screening for women with high genetic breast cancer risks

    Directory of Open Access Journals (Sweden)

    Hugo C

    2013-04-01

    Full Text Available Objectives: To examine intra-observer reliability (IR for lesion detection on contrast-enhanced breast magnetic resonance images (MRI for screening women at high risk of breast cancer in single and joint double readings, without case selection. Methods: Contrast-enhanced breast MRIs were interpreted twice by the same independent reader and twice in joint readings. IR was assessed for lesion detection, normal MRI identification, mass, non-mass like enhancements (NMLE and focus characterisation, and BI-RADS assessment. Results: MRI examinations for 124 breasts, 65 women (mean age 43.4y were retrospectively reviewed with 110 lesions identified. Abnormal BIRADS (3-5 classifications were found for 52.3% in single readings and 58.5% in joint readings. Seven biopsies were performed for 4 histologically confirmed cancers. IR for BI-RADS classifications was good for single (0.63, 95% CI: 0.49-0.77, and joint readings (0.77, 95% CI: 0.61-0.93. IR for background parenchymal enhancement (BPE was moderate across single (0.53, 95% CI: 0.40-0.65 and joint readings (0.44, 95% CI: 0.33-0.56. IR for BI-RADS category according to each enhancement was poor for single (0.27, 95% CI: 0.10-0.44, and higher for joint readings, (0.58, 95% CI: 0.43-0.72. Conclusions: IR in BI-RADS breast assessments or BI-RADS lesion assessments are better with joint reading in screening for women with high genetic risks, in particular for abnormal MRI (BI-RADS 3, 4 and 5.

  18. Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Xu Huixiong, E-mail: xuhuixiong@hotmail.co [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Lu Mingde, E-mail: lumd@21cn.co [Department of Hepatobiliary Surgery, First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China)

    2010-08-15

    Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

  19. High-contrast imaging testbed

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K; Silva, D; Poyneer, L; Macintosh, B; Bauman, B; Palmer, D; Remington, T; Delgadillo-Lariz, M

    2008-01-23

    Several high-contrast imaging systems are currently under construction to enable the detection of extra-solar planets. In order for these systems to achieve their objectives, however, there is considerable developmental work and testing which must take place. Given the need to perform these tests, a spatially-filtered Shack-Hartmann adaptive optics system has been assembled to evaluate new algorithms and hardware configurations which will be implemented in these future high-contrast imaging systems. In this article, construction and phase measurements of a membrane 'woofer' mirror are presented. In addition, results from closed-loop operation of the assembled testbed with static phase plates are presented. The testbed is currently being upgraded to enable operation at speeds approaching 500 hz and to enable studies of the interactions between the woofer and tweeter deformable mirrors.

  20. A fast-switching, contrast-enhanced liquid crystal polarization modulator for high-end, single-lens stereoscopic 3D projector applications

    Science.gov (United States)

    Osterman, Jesper; Ward, Chris; Scheffer, Terry

    2012-03-01

    We present a fast-switching, contrast-enhanced liquid crystal polarization modulator suitable for use as a polarization switch in time-multiplexed stereoscopic 3D applications. By utilizing a double-cell structure together with a dedicated driving scheme and an external quarter-wave retarder we can achieve fast, powered switching between two orthogonally polarized output states with completely symmetric operation between left and right eye images, including high extinction at all wavelengths for the dark states. The polarization modulator is especially attractive for the use in combination with high-end DLP®-based, single-lens stereoscopic 3D projectors operating at high frame rates, and enables high-brightness, low-ghosting viewing using lightweight and comfortable circular polarized passive 3D glasses. The practical advantages of a fast 50μs polarization modulator are discussed.

  1. Dual-energy contrast-enhanced mammography.

    Science.gov (United States)

    Travieso Aja, M M; Rodríguez Rodríguez, M; Alayón Hernández, S; Vega Benítez, V; Luzardo, O P

    2014-01-01

    The degree of vascularization in breast lesions is related to their malignancy. For this reason, functional diagnostic imaging techniques have become important in recent years. Dual-energy contrast-enhanced mammography is a new, apparently promising technique in breast cancer that provides information about the degree of vascularization of the lesion in addition to the morphological information provided by conventional mammography. This article describes the state of the art for dual-energy contrast-enhanced mammography. Based on 15 months' clinical experience, we illustrate this review with clinical cases that allow us to discuss the advantages and limitations of this technique. Copyright © 2014 SERAM. Published by Elsevier Espana. All rights reserved.

  2. Dynamic Contrast-Enhanced Digital Breast Tomosynthesis

    Science.gov (United States)

    2013-03-01

    500 or secretions due to pathological activity and can be precursors to breast cancers such as ductal carcinoma22, 23. Breast microcalcifications ... Breast Cancer Screening. Am J Med, in press. 650 2Gilles R, Meunier M, Lucidarme O, et al. (1996) Clustered breast microcalcifications : Evaluation... Breast Cancer , contrast-enhanced imaging, digital breast tomosynthesis, dynamic imaging, x-ray imaging 15. Number of Pages (count all pages

  3. Equilibrium-Phase High Spatial Resolution Contrast-Enhanced MR Angiography at 1.5T in Preoperative Imaging for Perforator Flap Breast Reconstruction

    Science.gov (United States)

    Boetes, Carla; Van Der Hulst, René; Lataster, Arno; Van Mulken, Tom; Wildberger, Joachim; de Haan, Michiel; Leiner, Tim

    2013-01-01

    Objectives The aim was (i) to evaluate the accuracy of equilibrium-phase high spatial resolution (EP) contrast-enhanced magnetic resonance angiography (CE-MRA) at 1.5T using a blood pool contrast agent for the preoperative evaluation of deep inferior epigastric artery perforator branches (DIEP), and (ii) to compare image quality with conventional first-pass CE-MRA. Methods Twenty-three consecutive patients were included. All patients underwent preoperative CE-MRA to determine quality and location of DIEP. First-pass imaging after a single bolus injection of 10 mL gadofosveset trisodium was followed by EP imaging. MRA data were compared to intra-operative findings, which served as the reference standard. Results There was 100% agreement between EP CE-MRA and surgical findings in identifying the single best perforator branch. All EP acquisitions were of diagnostic quality, whereas in 10 patients the quality of the first-pass acquisition was qualified as non-diagnostic. Both signal- and contrast-to-noise ratios were significantly higher for EP imaging in comparison with first-pass acquisitions (p<0.01). Conclusions EP CE-MRA of DIEP in the preoperative evaluation of patients undergoing a breast reconstruction procedure is highly accurate in identifying the single best perforator branch at 1.5Tesla (T). Besides accuracy, image quality of EP imaging proved superior to conventional first-pass CE-MRA. PMID:24009659

  4. Isotropic high-spatial-resolution contrast-enhanced 3.0-T MR angiography in patients suspected of having renal artery stenosis.

    Science.gov (United States)

    Kramer, Ulrich; Wiskirchen, Jakub; Fenchel, Michael C; Seeger, Achim; Laub, Gerhard; Tepe, Gunnar; Finn, J Paul; Claussen, Claus D; Miller, Stephan

    2008-04-01

    The purpose of this study was to prospectively evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) angiography performed at 3 T for assessment of renal artery stenosis (RAS) by using parallel acquisition techniques with high acceleration factors and with digital subtraction angiography (DSA) as the reference standard. The study was institutional review board approved, and written informed consent was obtained from all patients. Twenty-nine patients (18 men, 11 women; mean age, 57.1 years +/- 14.3 [standard deviation]) suspected of having RAS underwent MR angiography. Images were evaluated qualitatively and quantitatively. The interobserver variability, sensitivity, specificity, and positive and negative predictive values of 3-T MR angiography, as compared with DSA (performed in 15 patients), were calculated. All examinations yielded good or excellent image quality. The sensitivity and specificity of MR angiography in grading significant (>75%) stenosis were 94% and 96%, respectively. Owing to its high sensitivity, contrast-enhanced 3-T MR angiography can be used reliably to exclude RAS and can serve as a useful screening method in the diagnostic work-up of patients with arterial hypertension.

  5. Early biomarkers from dynamic contrast-enhanced magnetic resonance imaging to predict the response to antiangiogenic therapy in high-grade gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Piludu, Francesca; Vidiri, Antonello [Regina Elena National Cancer Institute, Radiology and Diagnostic Imaging Department, Rome (Italy); Marzi, Simona [Regina Elena National Cancer Institute, Medical Physics Laboratory, Rome (Italy); Pace, Andrea; Villani, Veronica [Regina Elena National Cancer Institute, Neurology Division, Rome (Italy); Fabi, Alessandra [Regina Elena National Cancer Institute, Oncology Department, Rome (Italy); Carapella, Carmine Maria [Regina Elena National Cancer Institute, Oncologic Surgery Department, Rome (Italy); Terrenato, Irene [Regina Elena National Cancer Institute, Biostatistics-Scientific Direction, Rome (Italy); Antenucci, Anna [Regina Elena National Cancer Institute, Clinical Pathology, Rome (Italy)

    2015-12-15

    The aim of this study is to investigate whether early changes in tumor volume and perfusion measurements derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) may predict response to antiangiogenic therapy in recurrent high-grade gliomas. Twenty-seven patients who received bevacizumab every 3 weeks were enrolled in the study. For each patient, three MRI scans were performed: at baseline, after the first dose, and after the fourth dose of bevacizumab. The entire tumor volume (V{sub tot}), as well as contrast-enhanced and noncontrast-enhanced tumor subvolumes (V{sub CE-T1} and V{sub NON-CE-T1}, respectively) were outlined using post-contrast T1-weighted images as a guide for the tumor location. Histogram analysis of normalized IAUGC (nIAUGC) and transfer constant K{sup trans} maps were performed. Each patient was classified as a responder patient if he/she had a partial response or a stable disease or as a nonresponder patient if he/she had progressive disease. Responding patients showed a larger reduction in V{sub NON-CE-T1} after a single dose, compared to nonresponding patients. Tumor subvolumes with increased values of nIAUGC and K{sup trans}, after a single dose, significantly differed between responders and nonresponders. The radiological response was found to be significantly associated to the clinical outcome. After a single dose, V{sub tot} was predictive of overall survival (OS), while V{sub CE-T1} showed a tendency of correlation with OS. Tumor subvolumes with increased nIAUGC and K{sup trans} showed the potential for improving the diagnostic accuracy of DCE. Early assessments of the entire tumor volume, including necrotic areas, may provide complementary information of tumor behavior in response to anti-VEGF therapies and is worth further investigation. (orig.)

  6. Fast mutual-information-based contrast enhancement

    Science.gov (United States)

    Cao, Gang; Yu, Lifang; Tian, Huawei; Huang, Xianglin; Wang, Yongbin

    2017-07-01

    Recently, T. Celik proposed an effective image contrast enhancement (CE) method based on spatial mutual information and PageRank (SMIRANK). According to the state-of-the-art evaluation criteria, it achieves the best visual enhancement quality among existing global CE methods. However, SMIRANK runs much slower than the other counterparts, such as histogram equalization (HE) and adaptive gamma correction. Low computational complexity is also required for good CE algorithms. In this paper, we novelly propose a fast SMIRANK algorithm, called FastSMIRANK. It integrates both spatial and gray-level downsampling into the generation of pixel value mapping function. Moreover, the computation of rank vectors is speeded up by replacing PageRank with a simple yet efficient row-based operation of mutual information matrix. Extensive experimental results show that the proposed FastSMIRANK could accelerate the processing speed of SMIRANK by about 20 times, and is even faster than HE. Comparable enhancement quality is preserved simultaneously.

  7. SU-F-I-16: Short Breast MRI with High-Resolution T2-Weighted and Dynamic Contrast Enhanced T1-Weighted Images

    Energy Technology Data Exchange (ETDEWEB)

    Ma, J; Son, J; Arun, B; Hazle, J; Hwang, K; Madewell, J; Yang, W; Dogan, B [UT MD Anderson Cancer Center, Houston, TX (United States); Wang, K; Bayram, E [GE Healthcare Technologies, Waukesha, Wisconsin (United States)

    2016-06-15

    Purpose: To develop and demonstrate a short breast (sb) MRI protocol that acquires both T2-weighted and dynamic contrast-enhanced T1-weighted images in approximately ten minutes. Methods: The sb-MRI protocol consists of two novel pulse sequences. The first is a flexible fast spin-echo triple-echo Dixon (FTED) sequence for high-resolution fat-suppressed T2-weighted imaging, and the second is a 3D fast dual-echo spoiled gradient sequence (FLEX) for volumetric fat-suppressed T1-weighted imaging before and post contrast agent injection. The flexible FTED sequence replaces each single readout during every echo-spacing period of FSE with three fast-switching bipolar readouts to produce three raw images in a single acquisition. These three raw images are then post-processed using a Dixon algorithm to generate separate water-only and fat-only images. The FLEX sequence acquires two echoes using dual-echo readout after each RF excitation and the corresponding images are post-processed using a similar Dixon algorithm to yield water-only and fat-only images. The sb-MRI protocol was implemented on a 3T MRI scanner and used for patients who had undergone concurrent clinical MRI for breast cancer screening. Results: With the same scan parameters (eg, spatial coverage, field of view, spatial and temporal resolution) as the clinical protocol, the total scan-time of the sb-MRI protocol (including the localizer, bilateral T2-weighted, and dynamic contrast-enhanced T1-weighted images) was 11 minutes. In comparison, the clinical breast MRI protocol took 43 minutes. Uniform fat suppression and high image quality were consistently achieved by sb-MRI. Conclusion: We demonstrated a sb-MRI protocol comprising both T2-weighted and dynamic contrast-enhanced T1-weighted images can be performed in approximately ten minutes. The spatial and temporal resolution of the images easily satisfies the current breast MRI accreditation guidelines by the American College of Radiology. The protocol has the

  8. High index contrast photonics platform

    Science.gov (United States)

    Chu, Sai T.; Little, Brent E.; Hryniewicz, John V.; Johnson, Fred G.; King, Oliver; Gill, Dave; Chen, Wenlu; Chen, Wei

    2005-10-01

    A new low-loss high-index-contrast photonics platform has been developed for integrated optics and microwave photonics. The platform consists of a material system that has an index contrast that is adjustable from 0 to 25% and which is processed using conventional CMOS tools. The platform allows one to four orders of magnitude reduction in the size of optical components compared with conventional planar technologies. As an example, meter long path lengths occupy coils that are millimeters in diameter. Microwave photonic building blocks that are enabled include large bit count programmable delay lines for beam steering and shaping that fit in less than a square centimeter and which have delays controllable from 5 fsec to 10 nsec. Also enabled are arrays of high order tunable filters, a hundred micrometers in size, having linewidths ranging from tens of MHz to tens of GHz. These filters can be tuned over several hundred GHz, and when placed in Vernier architectures can be tuned across the C band (5 THz). An optical chip typically consists of dozens of optical elements. Each element is placed in its own micro-control loop that consists of a thin film heater for thermo-optic control and a thermistor for electronic feedback. The micro-control loops impart intelligence to the optical chip.

  9. Dynamic contrast-enhanced imaging of the wrist in rheumatoid arthritis: dedicated low-field (0.25-T) versus high-field (3.0-T) MRI

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ryan K.L.; Griffith, James F.; Wang, D.F.; Yeung, David K.W. [The Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Prince Of Wales Hospital, Hong Kong, SAR (China); Shi, L. [The Chinese University of Hong Kong, Department of Medicine and Therapeutics, Division of Neurology, Hong Kong, SAR (China); Li, Edmund K.; Tam, L.S. [The Chinese University of Hong Kong, Department of Medicine, Division of Rheumatology, Prince Of Wales Hospital, Hong Kong, SAR (China)

    2015-08-15

    To compare the assessment of wrist synovitis severity, synovial volume and synovial perfusion parameters on a dedicated low-field (0.25-T) to that of a high-field (3-T) whole-body MR system in patients with rheumatoid arthritis (RA). Twenty-one patients (mean age 50.0 ± 9.8 years) with active RA were recruited prospectively. Dynamic contrast-enhanced MRI examination of the most severely affected wrist was performed at both 0.25 T and 3 T. Three MRI-derived parameters, synovitis severity (RAMRIS grade), synovial volume (ml{sup 3}) and synovial perfusion indices (maximum enhancement and enhancement slope), were compared. Comparing 0.25- and 3-T MRI, there was excellent agreement for semiquantitative assessment (r: 0.80, p < 0.00001) of synovitis (RAMRIS) as well as quantitative assessment (r: 0.94, p < 0.00001) of synovial volume. Good agreement for synovial Emax (r: 0.6, p = 0.002) and fair agreement (r: 0.5, p = 0.02) for synovial Eslope was found. Imaging of the RA wrist at 0.25 T yields excellent correlation with 3 T with regard to the synovitis activity score (RAMRIS) and synovial volume measurement. Fair to good correlation between low- (0.25-T) and high-field (3-T) MR systems was found for perfusion parameters, being better for Emax than for Eslope. (orig.)

  10. Contrast enhancement for images in turbid water.

    Science.gov (United States)

    Lu, Huimin; Li, Yujie; Zhang, Lifeng; Serikawa, Seiichi

    2015-05-01

    Absorption, scattering, and color distortion are three major degradation factors in underwater optical imaging. Light rays are absorbed while passing through water, and absorption rates depend on the wavelength of the light. Scattering is caused by large suspended particles, which are always observed in an underwater environment. Color distortion occurs because the attenuation ratio is inversely proportional to the wavelength of light when light passes through a unit length in water. Consequently, underwater images are dark, low contrast, and dominated by a bluish tone. In this paper, we propose a novel underwater imaging model that compensates for the attenuation discrepancy along the propagation path. In addition, we develop a robust color lines-based ambient light estimator and a locally adaptive filtering algorithm for enhancing underwater images in shallow oceans. Furthermore, we propose a spectral characteristic-based color correction algorithm to recover the distorted color. The enhanced images have a reasonable noise level after the illumination compensation in the dark regions, and demonstrate an improved global contrast by which the finest details and edges are enhanced significantly.

  11. Contrast induced nephropathy following intravenous contrast enhanced computed tomography

    NARCIS (Netherlands)

    Moos, S.I.

    2015-01-01

    Contrast induced nephropathy (CIN) is often described as an acute increase in serum creatinine following intravascular contrast medium administration. CIN is associated with adverse events such as permanent renal failure, increased risk for renal replacement therapy and death. To prevent the above

  12. Osteoblastic Metastases Mimickers on Contrast Enhanced CT

    Directory of Open Access Journals (Sweden)

    Fahad Al-Lhedan

    2017-01-01

    Full Text Available Secondary osseous involvement in lymphoma is more common compared to primary bone lymphoma. The finding of osseous lesion can be incidentally discovered during the course of the disease. However, osseous metastases are infrequently silent. Detection of osseous metastases is crucial for accurate staging and optimal treatment planning of lymphoma. The aim of imaging is to identify the presence and extent of osseous disease and to assess for possible complications such as pathological fracture of the load-bearing bones and cord compression if the lesion is spinal. We are presenting two patients with treated lymphoma who were in complete remission. On routine follow-up contrast enhanced CT, there were new osteoblastic lesions in the spine worrisome for metastases. Additional studies were performed for further evaluation of both of them which did not demonstrate any corresponding suspicious osseous lesion. The patients have a prior history of chronic venous occlusive thrombosis that resulted in collaterals formation. Contrast enhancement of the vertebral body marrow secondary to collaterals formation and venous flow through the vertebral venous plexus can mimic the appearance of spinal osteoblastic metastases.

  13. Contrast enhancement pattern in MR imaging of acute cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Deok; Cho, Mee Young; Lee, Chae Guk; Song, Dong Hoon [Inje University College of Medicine, Pusan (Korea, Republic of)

    1994-08-15

    To present the enhancement pattern of acute cerebral or cerebellar cortical infarctions aged 1-3 days on MR. Contrast-enhanced MR images of 26 patients with acute cerebral or cerebellar ischemic events were retrospectively reviewed. MR was performed within 3 days after ictus. Contrast enhancement in the area of infarction was observed in 61.5% (16/26) on MR. Of these 50% (13/26) showed non-parenchymal enhancement (NPE) representing either vascular or leptomeningeal enhancement, 7.7% (2/26) showed parenchymal enhancement (PE), and 2.8% (1/26) showed both NPE and PE. The earliest enhancement was seen in images obtained 12 hours after the onset of symptoms and appeared as NPE. One patient showed NPE without apparent high signal intensity at the corresponding area on T2-weighted images. In 38.5% (10/26), there was no enhancement. Contrast-enhanced MR imaging may be needed in acute ischemic infarction, because NPE may be seen as the earliest MR finding of acute cortical infraction aged 1-3 days.

  14. Evaluation of short-term response of high intensity focused ultrasound ablation for primary hepatic carcinoma: Utility of contrast-enhanced MRI and diffusion-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yuanyuan; Zhao Jiannong [Department of Radiology, Second Affiliated Hospital, Chongqing Medical University, No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010 (China); Guo Dajing, E-mail: guodaj@163.com [Department of Radiology, Second Affiliated Hospital, Chongqing Medical University, No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010 (China); Zhong Weijia [Department of Radiology, Second Affiliated Hospital, Chongqing Medical University, No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010 (China); Ran Lifen [Clinical Center for Tumor Therapy, Second Affiliated Hospital, Chongqing Medical University, No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010 (China)

    2011-09-15

    Objective: To explore the significance of contrast-enhanced MRI (CE-MRI) and diffusion-weighted imaging (DWI) in evaluating the short-term response of high intensity focused ultrasound (HIFU) ablation for primary hepatic carcinoma (PHC). Methods: Thirty-nine lesions in the livers of 27 patients were performed HIFU ablation. Conventional MRI sequences, CE-MRI and DWI were performed 1 week before HIFU and 1 week, 3 months after the therapy, respectively. The short-term responses of HIFU for all lesions were evaluated with MRI. Results: 28 of the 39 lesions (28/39, 71.8%) showed complete necrosis with no enhancement 1 week and 3 months after HIFU. The apparent diffusion coefficient (ADC) values 1 week and 3 months after HIFU were significantly higher than those 1 week before treatment (p < 0.05). The tumor recurrence was detected in 7 of the 39 lesions (7/39, 17.9%) which had no significant enhancement 1 week after HIFU. On the 3 months follow-up, focal nodules were found on the inner aspects of the treated areas. The ADC values had no significant difference between 1 week before and after treatment (p > 0.05), however, they were significantly higher 3 months after HIFU (p < 0.05). The tumor residuals were detected in 4 of the 39 lesions (4/39, 10.3%) showing enhancement 1 week after treatment and increased size 3 months after HIFU. The ADC values had no significant difference among 1 week before HIFU, 1 week and 3 months after treatment (p > 0.05). Conclusion: CE-MRI and DWI can be employed to evaluate the short-term response of HIFU ablation for PHC and to guide the patient management.

  15. Differentiation of Primary Central Nervous System Lymphoma and High-Grade Glioma with Dynamic Susceptibility Contrast-Enhanced Perfusion Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Weihua Liao; Yunhai Liu; Xiaoyi Wang; Xinya Jiang; Beisha Tang; Jiasheng Fang; Changqing Chen; Zhongliang Hu (Dept.s of Radiology, Neurology, Neurosurgery, and Pathology, Xiangya Hospital, Central South Univ., Changsha, Hunan (China))

    2009-02-15

    Background: Preoperative differentiation of primary central nervous system lymphomas (PCNSLs) from other tumors is important for presurgical staging, intraoperative management, and postoperative treatment. Dynamic susceptibility contrast-enhanced perfusion magnetic resonance imaging (DSC perfusion MRI) can provide in vivo assessment of the microvasculature in intracranial mass lesions. Purpose: To determine the utility of DSC perfusion MRI in the differentiation of PCNSLs and high-grade gliomas, as well as their pathological and physiological differences. Material and Methods: Nine patients with pathologically proven PCNSLs and 11 patients with high-grade gliomas were examined using a 1.5T MRI scanner. DSC perfusion MRI was performed by gradient-echo echo-planar imaging (GE-EPI). The maximum rCBV ratio, the signal intensity-time curves, and the percentage of signal intensity recovery were obtained. The maximum relative cerebral blood volume (rCBV) ratio and the percentage of signal intensity recovery of PCNSLs were compared with those of high-grade gliomas by using Student's t test. Microvessel density (MVD) was evaluated using immunohistochemical staining of surgical specimens with anti-CD34, and MVDs of the two tumor groups were compared by using Student's t test. Results: The maximum rCBV ratio of primary intracranial lymphomas was 1.72+-0.59, while that of high-grade gliomas was 4.86+-2.18. PCNSLs tended to have relatively low perfusion compared to high-grade gliomas (P=0.001), and the MVD labeled by anti-CD34 of PCNSLs was much lower than that of gliomas (P<0.001). The signal intensity-time curve of primary intracranial lymphomas was different from that of high-grade gliomas. The percentage of signal intensity recovery was significantly greater in PCNSLs compared with that of high-grade gliomas (P<0.001). Conclusion: The difference in DSC perfusion MRI characteristics between PCNSLs and high-grade gliomas is determined by their different

  16. Nonlinear contrast enhancement on subtraction images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Keon Il; Jin, Yeun Hwa [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Wonkwang University, Yongin (Korea, Republic of)

    1997-08-15

    This study was performed to demonstrate the effect of linear or nonlinear contrast enhancement on subtraction images. Three different textures were radiographed on dental film. The first radiograph was taken without the presence of an object. The second, which showed trabucular bone, was taken of the molar area of a human. the third radiograph was taken of the coronal part of molars. Each film was digitized into a 1312 x 1024 pixel x 8 bit depth matrix by means of a Nikon 35 mm film scanner(LS-3510AF, Japan) with fixed gain and internal dark current correction to maintain constant illumination. The scanner was interfaced to a Macintosh LC III computer(Apple Computer, Charlotte, N.C.). This resulted in three pairs of images, including different textures-plain, bone and enamel. Digital regular, linearly and nonlinearly enhanced subtraction was performed. Computer software was used to simulate lesions in the shape of a 2D-Gaussian curve on each of a pair of images. The each subtraction images were presented in a random sequence to two groups of 10 observers(students and dentists). ROC analysis was used to compare observer performance. The following results were obtained; 1. All of LCE subtraction, equalized subtraction and regular subtraction images of plain texture were diagnosed the best by far. 2. The data revealed a significant LCE effect in both the student group and the expert group. 3. Clinical expertise was a helpful factor for the observers in this study.

  17. Dynamic contrast enhanced MRI in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Alonzi, Roberto [Marie Curie Research Wing, Mount Vernon Cancer Centre, Rickmansworth Road, Northwood, Middlesex, HA6 2RN (United Kingdom)], E-mail: robertoalonzi@btinternet.com; Padhani, Anwar R. [Paul Strickland Scanner Centre, Mount Vernon Cancer Centre, Rickmansworth Road, Northwood, Middlesex, HA6 2RN (United Kingdom); Synarc Inc. 575 Market Street, San Francisco, CA 94105 (United States)], E-mail: anwar.padhani@paulstrickland-scannercentre.org.uk; Allen, Clare [Department of Imaging, University College Hospital, London, 235 Euston Road, NW1 2BU (United Kingdom)], E-mail: clare.allen@uclh.nhs.uk

    2007-09-15

    Angiogenesis is an integral part of benign prostatic hyperplasia (BPH), is associated with prostatic intraepithelial neoplasia (PIN) and is key to the growth and for metastasis of prostate cancer. Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) using small molecular weight gadolinium chelates enables non-invasive imaging characterization of tissue vascularity. Depending on the technique used, data reflecting tissue perfusion, microvessel permeability surface area product, and extracellular leakage space can be obtained. Two dynamic MRI techniques (T{sub 2}*-weighted or susceptibility based and T{sub 1}-weighted or relaxivity enhanced methods) for prostate gland evaluations are discussed in this review with reference to biological basis of observations, data acquisition and analysis methods, technical limitations and validation. Established clinical roles of T{sub 1}-weighted imaging evaluations will be discussed including lesion detection and localisation, for tumour staging and for the detection of suspected tumour recurrence. Limitations include inadequate lesion characterisation particularly differentiating prostatitis from cancer, and in distinguishing between BPH and central gland tumours.

  18. High Spatiotemporal Resolution Dynamic Contrast-Enhanced MR Enterography in Crohn Disease Terminal Ileitis Using Continuous Golden-Angle Radial Sampling, Compressed Sensing, and Parallel Imaging.

    Science.gov (United States)

    Ream, Justin M; Doshi, Ankur; Lala, Shailee V; Kim, Sooah; Rusinek, Henry; Chandarana, Hersh

    2015-06-01

    The purpose of this article was to assess the feasibility of golden-angle radial acquisition with compress sensing reconstruction (Golden-angle RAdial Sparse Parallel [GRASP]) for acquiring high temporal resolution data for pharmacokinetic modeling while maintaining high image quality in patients with Crohn disease terminal ileitis. Fourteen patients with biopsy-proven Crohn terminal ileitis were scanned using both contrast-enhanced GRASP and Cartesian breath-hold (volume-interpolated breath-hold examination [VIBE]) acquisitions. GRASP data were reconstructed with 2.4-second temporal resolution and fitted to the generalized kinetic model using an individualized arterial input function to derive the volume transfer coefficient (K(trans)) and interstitial volume (v(e)). Reconstructions, including data from the entire GRASP acquisition and Cartesian VIBE acquisitions, were rated for image quality, artifact, and detection of typical Crohn ileitis features. Inflamed loops of ileum had significantly higher K(trans) (3.36 ± 2.49 vs 0.86 ± 0.49 min(-1), p < 0.005) and v(e) (0.53 ± 0.15 vs 0.20 ± 0.11, p < 0.005) compared with normal bowel loops. There were no significant differences between GRASP and Cartesian VIBE for overall image quality (p = 0.180) or detection of Crohn ileitis features, although streak artifact was worse with the GRASP acquisition (p = 0.001). High temporal resolution data for pharmacokinetic modeling and high spatial resolution data for morphologic image analysis can be achieved in the same acquisition using GRASP.

  19. Ultrasonido con contraste de masas hepáticas Contrast-enhanced ultrasonography in hepatic masses

    Directory of Open Access Journals (Sweden)

    Hojun Yu

    2009-06-01

    Full Text Available El ultrasonido (US con contraste constituye una poderosa herramienta diagnóstica en la caracterización de masas hepáticas. Las modernas técnicas de ultrasonido con contraste presentan alta sensibilidad con dosis bajas de contraste, lo que juntamente con la técnica de supresión de ecos resulta en imágenes de muy alta resolución temporal y espacial, propiciando el resurgimiento de la ultrasonografía en la era de la tomografía computada (TC y de la resonancia magnética (RM. El agente de contraste utilizado es muy seguro, sin efectos de nefrotoxicidad y apropiado para pacientes con función renal disminuida. La posibilidad de utilizar múltiples inyecciones de micro burbujas y de realizar observaciones reiteradas de patrones de vascularización de las masas hepáticas, la convierten en una herramienta diagnóstica segura y confiable en la resolución de lesiones hepáticas indeterminadas previo a la TC y RM. En este artículo describimos los principios básicos del US con contraste, consideraciones prácticas en la realización de los estudios, debilidades y fortalezas del método en comparación con la TC y RM y patrones de vascularización en las cinco masas hepáticas más comunes: hemangioma, hiperplasia nodular focal, adenoma, carcinoma hepatocelular y metástasis.Contrast-enhanced ultrasonography (CEUS is a powerful tool in the characterization of various liver masses. Modern techniques of contrast ultrasonography are highly sensitive to minute doses of the contrast agent and with the suppression of background tissue echoes result in images with very high contrast resolution. Added to this advantage are the high temporal and spatial resolution intrinsic to sonography in general, which have resulted in a robust resurgence of sonography in this era of CT and MRI. The excellent safety profile of the contrast agent with no nephrotoxicity allows for multiple injections of microbubble in deciphering the vascular structure and enhancement

  20. Dynamic contrast-enhanced magnetic resonance imaging predicts immediate therapeutic response of magnetic resonance-guided high-intensity focused ultrasound ablation of symptomatic uterine fibroids.

    Science.gov (United States)

    Kim, Young-Sun; Lim, Hyo K; Kim, Jae-Hun; Rhim, Hyunchul; Park, Byung Kwan; Keserci, Bilgin; Köhler, Max O; Bae, Duk-Soo; Kim, Byoung-Gie; Lee, Jeong-Won; Kim, Tae-Joong; Sokka, Shunmugavelu; Lee, Jung Hee

    2011-10-01

    : To evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters in the prediction of the immediate therapeutic response of MR-guided high-intensity focused ultrasound (HIFU) therapy in the treatment of symptomatic uterine fibroids : Institutional review board approved this study, and informed consent was obtained from all participants. A total of 10 symptomatic uterine fibroids (diameter: mean, 8.9 cm; range, 4.7-12 cm) in 10 female patients (mean age, 42.2 years) were treated with MR-HIFU therapy using the volumetric ablation technique. DCE-MRI and conventional contrast-enhanced MRI were obtained as a baseline and as an immediate follow-up study, respectively. After regions of interest of each treatment cell were properly registered to both MRI studies, DCE-MRI parameters (K, ve, vp) and operator-controllable therapy parameters (power, treatment cell size, sonication depth) were investigated on a cell-by-cell basis to reflect tissue inhomogeneity. Two types of ablation efficacy indices (volume of 240 equivalent minutes at 43°C/treatment-cell volume, nonperfused volume/treatment-cell volume) were then correlated with those parameters using multiple linear regression analysis to determine which factors were significant predictors for ablation efficacy. : We used 293 treatment cells (4 mm, n = 12; 8 mm, n = 115; 12 mm, n = 149; 16 mm, n = 17), and all of them were analyzable. Ablation efficacies were 1.06 ± 0.58 and 0.67 ± 0.39. K (B = -12.035, P < 0.001 and B = -11.516, P < 0.001, respectively) among DCE-MRI parameters and acoustic power (B = 0.008, P < 0.001; B = 0.010, P < 0.001, respectively) among therapy parameters were revealed to be independently significant predictors for both types of ablation efficacy. : A higher K value at baseline DCE-MRI suggested a poor ablation efficacy of MR-HIFU therapy for symptomatic uterine fibroids.

  1. Contrast-enhanced spectral mammography (CESM) and contrast enhanced MRI (CEMRI): Patient preferences and tolerance.

    Science.gov (United States)

    Hobbs, Max M; Taylor, Donna B; Buzynski, Sebastian; Peake, Rachel E

    2015-06-01

    Contrast-enhanced spectral mammography (CESM) may have similar diagnostic performance to Contrast-enhanced MRI (CEMRI) in the diagnosis and staging of breast cancer. To date, research has focused exclusively on diagnostic performance when comparing these two techniques. Patient experience is also an important factor when comparing and deciding on which of these modalities is preferable. The aim of this study is to compare patient experience of CESM against CEMRI during preoperative breast cancer staging. Forty-nine participants who underwent both CESM and CEMRI, as part of a larger trial, completed a Likert questionnaire about their preference for each modality according to the following criteria: comfort of breast compression, comfort of intravenous (IV) contrast injection, anxiety and overall preference. Participants also reported reasons for preferring one modality to the other. Quantitative data were analysed using a Wilcoxon sign-rank test and chi-squared test. Qualitative data are reported descriptively. A significantly higher overall preference towards CESM was demonstrated (n = 49, P contrast injection (n = 49, P = 0.003). Our data suggest that overall, patients prefer the experience of CESM to CEMRI, adding support for the role of CESM as a possible alternative to CEMRI for breast cancer staging. © 2015 The Royal Australian and New Zealand College of Radiologists.

  2. Contrast-enhanced dedicated breast CT detection of invasive breast cancer preceding mammographic diagnosis

    Directory of Open Access Journals (Sweden)

    Nicolas D. Prionas, MD, PhD

    2015-01-01

    Full Text Available Dedicated breast computed tomography (bCT generates high-resolution, three-dimensional images of the pendent uncompressed breast. Intravenous iodinated contrast during bCT provides additional physiologic information. In this case, a 10.0-mm invasive ductal carcinoma was visualized using contrast-enhanced breast CT one year before mammographic detection. Mammography four months before bCT was negative. The bCT contrast enhancement pattern closely matched the dynamic contrast-enhanced MRI obtained after diagnosis. Lesion enhancement at contrast-enhanced breast CT matched previously published enhancement values of breast cancer. Contrast-enhanced dedicated bCT provided high-resolution tomographic images and physiologic contrast enhancement data that facilitated the detection of an early breast cancer.

  3. Contrast-enhanced ultrasonography revealed active thoracic bleeding.

    Science.gov (United States)

    Sugihara, Takaaki; Koda, Masahiko; Tokunaga, Shiho; Matono, Tomomitsu; Nagahara, Takakazu; Ueki, Masaru; Murawaki, Yoshikazu; Kaminou, Toshio

    2010-07-01

    A 61-year-old woman with a hepatocellular carcinoma located in the subphrenic region was treated by radiofrequency ablation (RFA) under artificial pleural effusion. During RFA, B-mode ultrasonography showed a swirling high echoic lesion in the artificial pleural effusion. A real-time scan performed using contrast-enhanced ultrasonography (CEUS) revealed a jet-like extravasation of contrast medium and pooling of microbubbles in the pleural cavity, which were confirmed by angiography. CEUS successfully identified the site of bleeding and can be regarded an effective tool for detecting active bleeding in an emergency.

  4. Contrast agent enhanced pQCT of articular cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Kallioniemi, A S [Department of Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Jurvelin, J S [Department of Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Nieminen, M T [Department of Diagnostic Radiology, POB 50, 90029 OYS, Oulu University Hospital, Oulu (Finland); Lammi, M J [Department of Anatomy, Institute of Biomedicine, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Toeyraes, J [Department of Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland)

    2007-02-21

    The delayed gadolinium enhanced MRI of cartilage (dGEMRIC) technique is the only non-invasive means to estimate proteoglycan (PG) content in articular cartilage. In dGEMRIC, the anionic paramagnetic contrast agent gadopentetate distributes in inverse relation to negatively charged PGs, leading to a linear relation between T{sub 1,Gd} and spatial PG content in tissue. In the present study, for the first time, contrast agent enhanced peripheral quantitative computed tomography (pQCT) was applied, analogously to dGEMRIC, for the quantitative detection of spatial PG content in cartilage. The suitability of two anionic radiographic contrast agents, gadopentetate and ioxaglate, to detect enzymatically induced PG depletion in articular cartilage was investigated. First, the interrelationships of x-ray absorption, as measured with pQCT, and the contrast agent solution concentration were investigated. Optimal contrast agent concentrations for the following experiments were selected. Second, diffusion rates for both contrast agents were investigated in intact (n = 3) and trypsin-degraded (n 3) bovine patellar cartilage. The contrast agent concentration of the cartilaginous layer was measured prior to and 2-27 h after immersion. Optimal immersion time for the further experiments was selected. Third, the suitability of gadopentetate and ioxaglate enhanced pQCT to detect the enzymatically induced specific PG depletion was investigated by determining the contrast agent concentrations and uronic acid and water contents in digested and intact osteochondral samples (n = 16). After trypsin-induced PG loss (-70%, p < 0.05) the penetration of gadopentetate and ioxaglate increased (p < 0.05) by 34% and 48%, respectively. Gadopentetate and ioxaglate concentrations both showed strong correlation (r = -0.95, r -0.94, p < 0.01, respectively) with the uronic acid content. To conclude, contrast agent enhanced pQCT provides a technique to quantify PG content in normal and experimentally

  5. Lesion Contrast Enhancement in Medical Ultrasound Imaging

    DEFF Research Database (Denmark)

    Stetson, Paul F.; Sommer, F.G.; Macovski, A.

    1997-01-01

    Methods for improving the contrast-to-noise ratio (CNR) of low-contrast lesions in medical ultrasound imaging are described. Differences in the frequency spectra and amplitude distributions of the lesion and its surroundings can be used to increase the CNR of the lesion relative to the background....... Automated graylevel mapping is used in combination with a contrast-weighted form of frequency-diversity speckle reduction. In clinical studies, the techniques have yielded mean CNR improvements of 3.2 dB above ordinary frequency-diversity imaging and 5.6 dB over sharper conventional images, with no post...

  6. Contrast-enhanced dedicated breast CT detection of invasive breast cancer preceding mammographic diagnosis

    OpenAIRE

    Prionas, Nicolas D.; Aminololama-Shakeri, Shadi; Yang, Kai; Martinez, Steve R.; Lindfors, Karen K.; Boone, John M.

    2015-01-01

    Dedicated breast computed tomography (bCT) generates high-resolution, three-dimensional images of the pendent uncompressed breast. Intravenous iodinated contrast during bCT provides additional physiologic information. In this case, a 10.0-mm invasive ductal carcinoma was visualized using contrast-enhanced breast CT one year before mammographic detection. Mammography four months before bCT was negative. The bCT contrast enhancement pattern closely matched the dynamic contrast-enhanced MRI obta...

  7. Clinical utility of a microbubble-enhancing contrast (“SonoVue”) in treatment of uterine fibroids with high intensity focused ultrasound: A retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Song [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, Department of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Non-invasive and Minimally Invasive Therapeutic Research Center for Uterine Benign Diseases of Chongqing, Chongqing 401121 (China); Xiong, Yu [Department of Obstetrics of Chongqing Haifu Hospital, Chongqing 401121 (China); Non-invasive and Minimally Invasive Therapeutic Research Center for Uterine Benign Diseases of Chongqing, Chongqing 401121 (China); Li, Kequan [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, Department of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Non-invasive and Minimally Invasive Therapeutic Research Center for Uterine Benign Diseases of Chongqing, Chongqing 401121 (China); He, Min [Department of Obstetrics of Chongqing Haifu Hospital, Chongqing 401121 (China); Department of Obstetrics and Gynecology, Suining Central Hospital, Sichuan 629000 (China); Deng, Yongbin; Chen, Li; Zou, Min [Department of Obstetrics of Chongqing Haifu Hospital, Chongqing 401121 (China); Chen, Wenzhi; Wang, Zhibiao [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, Department of Biomedical Engineering, Chongqing Medical University, Chongqing 400016 (China); Non-invasive and Minimally Invasive Therapeutic Research Center for Uterine Benign Diseases of Chongqing, Chongqing 401121 (China); He, Jia, E-mail: hejia0820@sina.com.cn [Department of Obstetrics and Gynecology, Suining Central Hospital, Sichuan 629000 (China); and others

    2012-12-15

    Purpose: To evaluate the clinical value of the contrast agent SonoVue in the treatment of uterine fibroids with ultrasound-guided high intensity focused ultrasound (HIFU) therapeutic ablation. Materials and Methods: A total of 291 patients with solitary uterine fibroid from three centers were treated with ultrasound-guided HIFU. Among them, 129 patients from Suining Central Hospital of Sichuan were treated without using SonoVue. 162 patients from the First Hospital of Chongqing Medical University and Chongqing Haifu Hospital were treated with using SonoVue before, during and after HIFU procedure to assess the extent of HIFU. Results: The non-perfused volume (indicative of successful ablation) was observed in all treated uterine fibroids immediately after HIFU ablation; median fractional ablation, defined as non-perfused volume divided by the fibroid volume immediately after HIFU treatment, was 86.0% (range, 28.8–100.0%) in the group with using SonoVue, and 83.0% (8.7–100.0%) without SonoVue. The rate of massive gray scale changes was higher with SonoVue than without the agent. The sonication time to achieve massive gray scale changes was shorter with SonoVue than without. The sonication time for ablating 1 cm{sup 3} of fibroid volume was significantly shorter with using SonoVue than without. No major complications were observed in any patients. Conclusions: Based on our results, SonoVue may enhance the outcome of HIFU ablation and can be used to assess the extent of treatment.

  8. Characterizing the contrast of white matter and grey matter in high-resolution phase difference enhanced imaging of human brain at 3.0 T

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li [Fudan University, Department of Radiology, Shanghai Institute of Medical Imaging, Zhongshan Hospital, Shanghai (China); Shandong University, Shandong Medical Imaging Research Institute, Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-cerebral Vascular Diseases, Jinan, Shandong (China); Wang, Shanshan; Yao, Bin; Li, Lili; Guo, Lingfei; Zhang, Xinjuan; Wang, Guangbin [Shandong University, Shandong Medical Imaging Research Institute, Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-cerebral Vascular Diseases, Jinan, Shandong (China); Xu, Xiaofei [Erasmus University Rotterdam, Laboratory of Experimental Tumor Immunology, Department of Medical Oncology, Erasmus Medical Center Cancer Institute, Rotterdam (Netherlands); Zhao, Lianxin [Shandong University, Department of Radiology, Qilu Hospital, Jinan, Shandong (China); Chen, Weibo; Chan, Queenie [Philips Healthcare, Shanghai (China)

    2015-04-01

    The purpose of this study was to address the feasibility of characterizing the contrast both between and within grey matter and white matter using the phase difference enhanced (PADRE) technique. PADRE imaging was performed in 33 healthy volunteers. Vessel enhancement (VE), tissue enhancement (TE), and PADRE images were reconstructed from source images and were evaluated with regard to differentiation of grey-to-white matter interface, the stria of Gennari, and the two layers, internal sagittal stratum (ISS) and external sagittal stratum (ESS), of optic radiation. White matter regions showed decreased signal intensity compared to grey matter regions. Discrimination was sharper between white matter and cortical grey matter in TE images than in PADRE images, but was poorly displayed in VE images. The stria of Gennari was observed on all three image sets. Low-signal-intensity bands displayed in VE images representing the optic radiation were delineated as two layers of different signal intensities in TE and PADRE images. Statistically significant differences in phase shifts were found between frontal grey and white matter, as well as between ISS and ESS (p < 0.01). The PADRE technique is capable of identifying grey-to-white matter interface, the stria of Gennari, and ISS and ESS, with improved contrast in PADRE and TE images compared to VE images. (orig.)

  9. Angular compounded OCTA for flow contrast enhancement (Conference Presentation)

    Science.gov (United States)

    Li, Peng; Li, Pei; Cheng, Yuxuan; Zhou, Liping; Ding, Zhihua

    2017-02-01

    Optical coherence tomography angiography (OCTA) is a promising imaging modality that enables a label-free, high-resolution and high-contrast image of biological tissue microvasculature. Typically, the blood flow contrast is implemented by mathematically analyzing the temporal dynamics of light scattering, and setting a threshold to distinguish the dynamic blood flow from the static tissue bed. However, high flow contrast is degraded by the residual overlap that results in misclassification errors between dynamic and static signals. Our study has demonstrated that flow contrast can be enhanced using a single-shot angular compounded OCTA (AC-OCTA). Because a continuous modulation is induced by the offset that the probing beam is away from the beam center in the typical OCT sample arm, different incidence angles in the probing beam are encoded in B-scan modulation frequencies. The complex-valued spectral interferogram is reconstructed by removing the conjugate terms in the depth space and its Fourier transform along the transversal fast-scan direction generates a wide conjugate-free B-scan modulation spectrum in the full space of the spatial domain. By splitting the modulation spectrum, angle-resolved independent sub-angiograms are generated and then compounded to enhance the flow contrast. Both flow phantom and in vivo animal cerebral vascular imaging demonstrated that the proposed angular compounded OCTA can offer a 50% decrease of misclassification errors and an improved flow contrast and vessel connectivity. This AC-OCTA is beneficial to facilitating the interpretation of OCT angiograms in clinical applications.

  10. The forgotten organ: Contrast enhanced sonography of the spleen

    Energy Technology Data Exchange (ETDEWEB)

    Goerg, Christian [Medizinische Universitaetsklinik, Baldingerstrasse, 35043 Marburg/Lahn (Germany)], E-mail: goergc@med.uni-marburg.de

    2007-11-15

    Objective: Ultrasound contrast agents in conjunction with contrast specific imaging techniques, are increasingly accepted in clinical use for diagnostic imaging in several organs. Contrast enhanced sonography (CES) of second-generation contrast media have shown a spleen-specific uptake of the microbubble contrast agent. The aim of this review is to illustrate indications for the use of CES in patients with suspected (peri-)splenic pathology. Methods: This review based on the experience of transcutaneous CES in 200 patients with (peri-)splenic pathology diagnosed by B-mode sonography at an internal medicine center. CES studies were performed with a contrast-devoted unit (Acuson, Sequoia, Siemens medical solution) that had contrast-specific, continuous-mode software. A low mechanical index was used. A sulfur hexafluoride-based microbubble contrast medium (Sonovue, Bracco SpA, Milan, Italy) was injected. Results: On our experience, there are several clinical conditions which may show an diagnostic advantage of CES in comparison to B-mode US. CES should be performed to investigate: (1) the perisplenic tumor to diagnose or exclude accessory spleen, (2) the small-sized spleen to diagnose functional asplenia/hyposplenia, (3) the inhomogenous spleen of unknown cause to diagnose focal lesions within the spleen, (4) the incidentally found hypoechoic splenic tumor to diagnose high vascular splenic hemangioma, (5) focal lesions suspect for splenic abscess, hematoma, infarction to confirme diagnosis, and (6) patients with abdominal trauma to diagnose or exclude splenic injuriy. Conclusion: CES is of diagnostic value in several clinical circumstances to diagnose accessory spleen, functional asplenia, small-sized splenic involvement, high vascular splenic hemangioma, and vascular splenic pathology like splenic infarction, splenic abscess, and splenic laceration.

  11. Contrast enhancement by lipid-based MRI contrast agents in mouse atherosclerotic plaques; a longitudinal study

    NARCIS (Netherlands)

    den Adel, Brigit; van der Graaf, Linda M.; Que, Ivo; Strijkers, Gustav J.; Löwik, Clemens W.; Poelmann, Robert E.; van der Weerd, Louise

    2013-01-01

    The use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of two differently sized gadolinium-based contrast agents to enhance atherosclerotic plaques in ApoE(-/-) mice was evaluated with MRI. We

  12. Appropriate Contrast Enhancement Measures for Brain and Breast Cancer Images

    OpenAIRE

    Suneet Gupta; Rabins Porwal

    2016-01-01

    Medical imaging systems often produce images that require enhancement, such as improving the image contrast as they are poor in contrast. Therefore, they must be enhanced before they are examined by medical professionals. This is necessary for proper diagnosis and subsequent treatment. We do have various enhancement algorithms which enhance the medical images to different extents. We also have various quantitative metrics or measures which evaluate the quality of an image. This paper suggests...

  13. High Framerate Imaging of Ultrasound Contrast Agents

    OpenAIRE

    Viti, Jacopo

    2016-01-01

    markdownabstractUltrasound contrast agents (UCAs) consists of a suspension of tiny gas bubbles that is injected into a patient's bloodstream to enhance the visualization of blood in ultrasound images. As UCAs respond differently to ultrasound pulses compared to the surrounding soft tissues and blood, it is possible to employ specialized techniques to identify and isolate UCAs in an ultrasound image. This is commonly referred to as Ultrasound Contrast Imaging. This PhD thesis evaluates several...

  14. Gold Nanoparticle-Based Fluorescent Contrast Agent with Enhanced Sensitivity.

    Science.gov (United States)

    Kang, Kyung Aih; Nguyen, Mai-Dung

    2017-01-01

    Gold nanoparticle (GNP) based contrast agents that are highly specific and sensitive for both optical and X-ray/CT imaging modalities are being developed for detecting the cancer expressing nucleolin and matrix metallo-proteinase 14 (MMP-14) on the cell membrane: Nucleolin is normally present in the nucleus. For many cancer cells, however, it is over-expressed on the cell membrane, having it to be a good cancer marker. Aptamer AS1411 is known to be an excellent target for nucleolin and also known to treat several cancer types; and MMP-14 in cancer is involved in tumor angiogenesis, blood vessel re-organization, and metastasis. In the proposed agent, AS1411 is selected as the cancer targeting molecule; and the unique property of GNPs of modulating fluorescence are utilized to allow the agent to trigger its fluorescence upon reacting with MMP-14, at an enhanced fluorescence level. GNPs are also natural X-ray/CT contrast agent. Here, as a part of on-going development of the dual-modality contrast agent, we report that conjugating a safe, NIR fluorophore Cypate at a precisely determined distance from the GNP enhanced the Cypate fluorescence up to two times. In addition, successful conjugation of the nucleolin target AS1411 onto the GNP was confirmed and among the GNPs size range 5-30 nm tested, 10 nm GNPs showed the highest X-ray/CT enhancement.

  15. Non-contrast-enhanced magnetic resonance angiography: techniques and applications.

    Science.gov (United States)

    Blankholm, Anne Dorte; Ringgaard, Steffen

    2012-01-01

    Non-contrast-enhanced magnetic resonance angiography has gained renewed interest since the discovery of the association between gadolinium-based contrast agents and nephrogenic systemic fibrosis. The following article is an overview of the different magnetic resonance angiography sequences, the technical possibilities and new developments. Clinical options and recent advancements will be highlighted, and recommendations for non-contrast-enhanced magnetic resonance angiography techniques in different anatomical regions will be given. Furthermore, the authors seek to predict the future of non-contrast-enhanced magnetic resonance angiography, with special focus on patients at risk.

  16. Influence of contrast-enhanced ultrasound administration setups on microbubble enhancement: a focus on pediatric applications.

    Science.gov (United States)

    Kramer, Michael R; Bhagat, Nishi; Back, Susan J; Poznick, Laura; Forsberg, Flemming; Darge, Kassa; Eisenbrey, John R

    2017-09-11

    In pediatrics, contrast-enhanced ultrasound offers high-quality imaging with an excellent safety profile. To investigate the effects of varying intravenous administration setups on in vitro enhancement and concentration of two commercially available ultrasound contrast agents, taking into consideration potential pediatric applications. We quantified in vitro enhancement using a flow phantom (ATS Laboratories, Bridgeport, CT) and Acuson S3000 ultrasound system (Siemens Healthineers, Mountain View, CA) with a 9L4 probe in Cadence pulse sequencing mode. We determined microbubble concentration with an LSRII flow cytometer (BD Biosciences, San Jose, CA). We investigated Optison (GE Healthcare, Princeton, NJ) and Lumason (Bracco, Geneva, Switzerland) ultrasound contrast agents. The ultrasound (US) contrast agent was injected via a 1 mL syringe and flushed with 5 mL of saline through a 22-gauge diffusion catheter (BD Medical, Franklin Lakes, NJ) with the following variations: in-line injection through a 3-way stopcock with and without a neutral displacement connector (ICU Medical, San Clemente, CA), perpendicular through a 3-way stopcock with and without a connector, and without a 3-way stopcock. We also conducted injections through a 22-gauge standard angiocatheter. Injection through the connector and perpendicular injection via the 3-way stopcock resulted in significant decreases in enhancement for both ultrasound contrast agents (P0.24) nor use of a pediatric diffusion catheter (P>0.28) affected the enhancement. Ultrasound contrast agent enhancement depends on the administration route, although some effects appear to be specific to the ultrasound contrast agent used. To avoid loss of enhancement, neutral displacement connectors and perpendicular injection should be avoided.

  17. Contrast-enhanced Dedicated Breast CT: Initial Clinical Experience1

    Science.gov (United States)

    Prionas, Nicolas D.; Ray, Shonket; Huang, Shih-Ying; Beckett, Laurel A.; Monsky, Wayne L.; Boone, John M.

    2010-01-01

    Purpose: To quantify contrast material enhancement of breast lesions scanned with dedicated breast computed tomography (CT) and to compare their conspicuity with that at unenhanced breast CT and mammography. Materials and Methods: Approval of the institutional review board and the Radiation Use Committee and written informed consent were obtained for this HIPAA-compliant study. Between September 2006 and April 2009, 46 women (mean age, 53.2 years; age range, 35–72 years) with Breast Imaging Reporting and Data System category 4 or 5 lesions underwent unenhanced breast CT and contrast material–enhanced breast CT before biopsy. Two radiologists independently scored lesion conspicuity for contrast-enhanced breast CT versus mammography and for contrast-enhanced breast CT versus unenhanced breast CT. Mean lesion voxel intensity was measured in Hounsfield units and normalized to adipose tissue intensity on manually segmented images obtained before and after administration of contrast material. Regression models focused on conspicuity and quantified enhancement were used to estimate the effect of pathologic diagnosis (benign vs malignant), lesion type (mass vs calcifications), breast density, and interradiologist variability. Results: Fifty-four lesions (25 benign, 29 malignant) in 46 subjects were analyzed. Malignant lesions were seen significantly better at contrast-enhanced breast CT than at unenhanced breast CT (P mammography (P contrast-enhanced breast CT than at unenhanced breast CT (P contrast-enhanced breast CT and mammography. Malignant lesions enhanced 55.9 HU ± 4.0 (standard error), whereas benign lesions enhanced 17.6 HU ± 6.1 (P contrast-enhanced breast CT. Quantifying lesion enhancement may aid in the detection and diagnosis of breast cancer. © RSNA, 2010 PMID:20720067

  18. High temporal and spatial resolution 3D time-resolved contrast-enhanced magnetic resonance angiography of the hands and feet.

    Science.gov (United States)

    Haider, Clifton R; Riederer, Stephen J; Borisch, Eric A; Glockner, James F; Grimm, Roger C; Hulshizer, Thomas C; Macedo, Thanila A; Mostardi, Petrice M; Rossman, Phillip J; Vrtiska, Terri J; Young, Phillip M

    2011-07-01

    Methods are described for generating 3D time-resolved contrast-enhanced magnetic resonance (MR) angiograms of the hands and feet. Given targeted spatial resolution and frame times, it is shown that acceleration of about one order of magnitude or more is necessary. This is obtained by a combination of 2D sensitivity encoding (SENSE) and homodyne (HD) acceleration methods. Image update times from 3.4-6.8 seconds are provided in conjunction with view sharing. Modular receiver coil arrays are described which can be designed to the targeted vascular region. Images representative of the technique are generated in the vasculature of the hands and feet in volunteers and in patient studies. Copyright © 2011 Wiley-Liss, Inc.

  19. Intraprocedure contrast enhanced ultrasound: the value in assessing the effect of ultrasound-guided high intensity focused ultrasound ablation for uterine fibroids.

    Science.gov (United States)

    Peng, Song; Hu, Liang; Chen, Wenzhi; Chen, Jinyun; Yang, Caiyong; Wang, Xi; Zhang, Rong; Wang, Zhibiao; Zhang, Lian

    2015-04-01

    To investigate the value of microbubble contrast-enhanced ultrasound (CEUS) in evaluating the treatment response of uterine fibroids to HIFU ablation. Sixty-eight patients with a solitary uterine fibroid from the First Affiliated Hospital of Chongqing Medical University were included and analyzed. All patients underwent pre- and post-treatment magnetic resonance imaging (MRI) with a standardized protocol, as well as pre-evaluation, intraprocedure, and immediate post-treatment CEUS. CEUS and MRI were compared by different radiologists. In comparison with MRI, CEUS showed that the size of fibroids, volume of fibroids, size of non-perfused regions, non-perfused volume (NPV) or fractional ablation (NPV ratio) was similar to that of MRI. In terms of CEUS examination results, the median volume of fibroids was 75.2 (interquartile range, 34.2-127.3) cm(3), the median non-perfused volume was 54.9 (interquartile range, 28.0-98.1) cm(3), the mean fractional ablation was 83.7±13.6 (range, 30.0-100.0)%. In terms of MRI examination results, the median volume of fibroids was 74.1 (interquartile range, 33.4-116.2) cm(3). On the basis of contrast-enhanced T1-weighted images immediately after HIFU treatment, the median non-perfused volume was 58.5 (interquartile range, 27.7-100.0) cm(3), the average fractional ablation was 84.2±14.2 (range, 40.0-100.0)%. CEUS clearly showed the size of fibroids and the non-perfused areas of the fibroid. Results from CEUS correlated well with results obtained from MRI. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Role of high resolution contrast-enhanced magnetic resonance angiography (HR CeMRA) in management of arterial complications of the renal transplant

    Energy Technology Data Exchange (ETDEWEB)

    Ismaeel, M. Maged [Suez Canal University (Egypt); Abdel-Hamid, Azza, E-mail: azza4951@hotmail.com [Suez Canal University (Egypt)

    2011-08-15

    Introduction: Transplant renal artery (RA) stenosis (TRAS) is the most frequent posttransplantation vascular complication. Contrast enhanced magnetic resonance (CeMRA) angiography has been established as the preferred imaging technique for the evaluation of TRAS because it does not require the use of iodinated contrast material and does not expose the patient to ionizing radiation. Digital subtraction angiography (DSA) is the gold standard in the evaluation of arterial tree of the renal allograft. Aim of the work: This study was carried out to assess the accuracy of CeMRA in the detection of arterial complications after renal transplantation. Patients and methods: Thirty renal transplant patients with suspected arterial complications in which both CeMRA and DSA were performed were included in the study. The HR CeMRA shows 93.7% sensitivity, 80% specificity, 88.2% positive predictive value, 88.9% negative predictive value and 88.5% accuracy. Conclusion: HR CeMRA is an accurate reliable tool in the assessment of arterial complications after renal transplantation. It may replace DSA as a diagnostic modality with reservation of interventional techniques for endovascular treatment of suitable cases.

  1. High Framerate Imaging of Ultrasound Contrast Agents

    NARCIS (Netherlands)

    J. Viti (Jacopo)

    2016-01-01

    markdownabstractUltrasound contrast agents (UCAs) consists of a suspension of tiny gas bubbles that is injected into a patient's bloodstream to enhance the visualization of blood in ultrasound images. As UCAs respond differently to ultrasound pulses compared to the surrounding soft tissues and

  2. Contrast-enhanced ultrasound for liver imaging: recent advances.

    Science.gov (United States)

    Salvatore, Veronica; Borghi, Alberto; Piscaglia, Fabio

    2012-01-01

    Contrast-enhanced ultrasonography (CEUS), providing relevant informations not available with non-enhanced ultrasonography, greatly impacted the practice of liver imaging. The characterization of focal liver lesions (FLLs), is obtained in a rapid, accurate and safe way and is considered the main hepatic indication; however CEUS offers other established or emergent relevant applications. Metastases detection and assessment of response to locoregional tumor treatment are accepted applications with specific indications. Needle guidance in case of poorly or non visible target lesions at conventional ultrasound is also accepted. The early assessment of response to systemic treatment, and in particular to antiangiogenic ones, by quantification software is an emergent application. The manageability of CEUS determined also its use in the operating theatre, improving the accuracy of intraoperatory US with a significant impact on final surgical strategy. In cirrhotic patients, the role of CEUS was proven highly accurate and sensitive in the characterization of portal vein thrombosis, by identification of contrast arterial enhancement inside the thrombus, that occurs only in case of neoplastic origin. In recent years microbubbles taken up by Kupffer cells, thus possessing a "postvascular" phase, were registered as ultrasound contrast agent in Japan (Sonazoid). During the post-vascular phase tumoral tissue tend to appear as a contrast defect image due to the lack of Kupffer cells, strongly contributing to tumor staging beside characterization. Newly developed techniques, such as fusion imaging or real-time three dimensional US, in addition to other applications of CEUS, in terms of post-transplantation or cholecystitis-related complications, have been recently proposed and will be discussed.

  3. Activatable Water-Soluble Probes Enhance Tumor Imaging by Responding to Dysregulated pH and Exhibiting High Tumor-to-Liver Fluorescence Emission Contrast.

    Science.gov (United States)

    Xiong, Hu; Kos, Petra; Yan, Yunfeng; Zhou, Kejin; Miller, Jason B; Elkassih, Sussana; Siegwart, Daniel J

    2016-07-20

    Dysregulated pH has been recognized as a universal tumor microenvironment signature that can delineate tumors from normal tissues. Existing fluorescent probes that activate in response to pH are hindered by either fast clearance (in the case of small molecules) or high liver background emission (in the case of large particles). There remains a need to design water-soluble, long circulating, pH-responsive nanoprobes with high tumor-to-liver contrast. Herein, we report a modular chemical strategy to create acidic pH-sensitive and water-soluble fluorescent probes for high in vivo tumor detection and minimal liver activation. A combination of a modified Knoevenagel reaction and PEGylation yielded a series of NIR BODIPY fluorophores with tunable pKas, high quantum yield, and optimal orbital energies to enable photoinduced electron transfer (PeT) activation in response to pH. After intravenous administration, Probe 5c localized to tumors and provided excellent tumor-to-liver contrast (apparent T/L = 3) because it minimally activates in the liver. This phenomenon was further confirmed by direct ex vivo imaging experiments on harvested organs. Because no targeting ligands were required, we believe that this report introduces a versatile strategy to directly synthesize soluble probes with broad potential utility including fluorescence-based image-guided surgery, cancer diagnosis, and theranostic nanomedicine.

  4. CONTRAST ENHANCED SPECTRAL MAMMOGRAPHY (CESM (REVIEW

    Directory of Open Access Journals (Sweden)

    N. I. Rozhkova

    2015-01-01

    Full Text Available The problem of early diagnosis of a breast cancer is extremely actual. Growth of incidence at women from 19 to 39 years increased for 34% over the last 10 years. It defines need of acceleration of development and deployment of the latest technologies of identification of the earliest symptoms of diseases. The x-ray mammography is the conducting method among of all radiological methods of diagnostics. Nevertheless a number of restrictions of method reduces its efficiency. The technologies increasing informational content of x-ray mammography – the leading method of screening – due to use of artificial contrasting and advantages of digital technologies are constantly developed. In this review it is described works, in which the authors having clinical experience of application of CESM – contrastenhanced spectral mammography on representative group of women. Positive sides and restrictions of new technology in comparison with mammography, ultrasonography and MRT are shown in this article.

  5. Digital mammography using iodine-based contrast media: initial clinical experience with dynamic contrast medium enhancement.

    Science.gov (United States)

    Diekmann, Felix; Diekmann, Susanne; Jeunehomme, Fanny; Muller, Serge; Hamm, Bernd; Bick, Ulrich

    2005-07-01

    We sought to evaluate the potential of dynamic contrast enhancement after the intravenous administration of an iodine-based contrast medium in full-field digital mammography. A protocol for image acquisition was established for contrast-enhanced mammography and the mammography unit (Senographe 2000D, GE Healthcare, Buc, France) changed as required. The effect of the protocol parameters on imaging was investigated. Subsequently, 21 patients with 25 suspicious lesions of the breast (10 benign, 1 borderline, and 14 malignant) underwent mammography with administration of an iodine-based contrast medium (Ultravist 370, Schering AG, Berlin, Germany), after approval of ethical committee as well as permission of German federal office for Radiation protection, and informed consent from each patient was obtained. Three sequential digital mammographic images of the respective breast were acquired after administration of the contrast medium at a dose of 1 mL/kg body weight and a flow of 4 mL/s. The postcontrast images were acquired 60, 120, and 180 seconds after administration. Subsequently, the precontrast image was logarithmically subtracted from the postcontrast images. Enhancement of the lesions was measured in absolute terms as well as relative to the enhancement of the glandular tissue. The subtracted images were evaluated for lesion depiction and dynamic contrast enhancement. Lesion-enhancement kinetics were compared with the histologic findings. All malignant lesions were identified on the contrast-enhanced images of digital mammography. Three of the tumors (2 malignant, 1 benign) were detected only by contrast-enhanced mammography and not by standard mammography. Dynamic enhancement curves of benign and malignant tumors in contrast-enhanced mammography look similar to the curves known from gadolinium-enhanced magnetic resonance imaging. Nevertheless differentiation between malignant and benign tumors based on the enhancement patterns cannot be directly taken over from

  6. Temporal subtraction contrast-enhanced dedicated breast CT

    Science.gov (United States)

    Gazi, Peymon M.; Aminololama-Shakeri, Shadi; Yang, Kai; Boone, John M.

    2016-09-01

    The development of a framework of deformable image registration and segmentation for the purpose of temporal subtraction contrast-enhanced breast CT is described. An iterative histogram-based two-means clustering method was used for the segmentation. Dedicated breast CT images were segmented into background (air), adipose, fibroglandular and skin components. Fibroglandular tissue was classified as either normal or contrast-enhanced then divided into tiers for the purpose of categorizing degrees of contrast enhancement. A variant of the Demons deformable registration algorithm, intensity difference adaptive Demons (IDAD), was developed to correct for the large deformation forces that stemmed from contrast enhancement. In this application, the accuracy of the proposed method was evaluated in both mathematically-simulated and physically-acquired phantom images. Clinical usage and accuracy of the temporal subtraction framework was demonstrated using contrast-enhanced breast CT datasets from five patients. Registration performance was quantified using normalized cross correlation (NCC), symmetric uncertainty coefficient, normalized mutual information (NMI), mean square error (MSE) and target registration error (TRE). The proposed method outperformed conventional affine and other Demons variations in contrast enhanced breast CT image registration. In simulation studies, IDAD exhibited improvement in MSE (0-16%), NCC (0-6%), NMI (0-13%) and TRE (0-34%) compared to the conventional Demons approaches, depending on the size and intensity of the enhancing lesion. As lesion size and contrast enhancement levels increased, so did the improvement. The drop in the correlation between the pre- and post-contrast images for the largest enhancement levels in phantom studies is less than 1.2% (150 Hounsfield units). Registration error, measured by TRE, shows only submillimeter mismatches between the concordant anatomical target points in all patient studies. The algorithm was

  7. Ultrafast 3D spin-echo acquisition improves Gadolinium-enhanced MRI signal contrast enhancement

    Science.gov (United States)

    Han, S. H.; Cho, F. H.; Song, Y. K.; Paulsen, J.; Song, Y. Q.; Kim, Y. R.; Kim, J. K.; Cho, G.; Cho, H.

    2014-01-01

    Long scan times of 3D volumetric MR acquisitions usually necessitate ultrafast in vivo gradient-echo acquisitions, which are intrinsically susceptible to magnetic field inhomogeneities. This is especially problematic for contrast-enhanced (CE)-MRI applications, where non-negligible T2* effect of contrast agent deteriorates the positive signal contrast and limits the available range of MR acquisition parameters and injection doses. To overcome these shortcomings without degrading temporal resolution, ultrafast spin-echo acquisitions were implemented. Specifically, a multiplicative acceleration factor from multiple spin echoes (×32) and compressed sensing (CS) sampling (×8) allowed highly-accelerated 3D Multiple-Modulation-Multiple-Echo (MMME) acquisition. At the same time, the CE-MRI of kidney with Gd-DOTA showed significantly improved signal enhancement for CS-MMME acquisitions (×7) over that of corresponding FLASH acquisitions (×2). Increased positive contrast enhancement and highly accelerated acquisition of extended volume with reduced RF irradiations will be beneficial for oncological and nephrological applications, in which the accurate in vivo 3D quantification of contrast agent concentration is necessary with high temporal resolution. PMID:24863102

  8. Dendrimers as high relaxivity MR contrast agents.

    Science.gov (United States)

    Longmire, Michelle R; Ogawa, Mikako; Choyke, Peter L; Kobayashi, Hisataka

    2014-01-01

    Dendrimers are versatile macromolecules with tremendous potential as magnetic resonance imaging (MRI) contrast agents. Dendrimer-based agents provide distinct advantages over low-molecular-weight gadolinium chelates, including enhanced r1 relaxivity due to slow rotational dynamics, tunable pharmacokinetics that can be adapted for blood pool, liver, kidney, and lymphatic imaging, the ability to be a drug carrier, and flexibility for labeling due to their inherent multivalency. Clinical applications are increasingly being developed, particularly in lymphatic imaging. Herein we present a broad overview of dendrimer-based MRI contrast agents with attention to the unique chemistry and physical properties as well as emerging clinical applications. © 2013 Wiley Periodicals, Inc.

  9. Enhancement of multispectral thermal infrared images - Decorrelation contrast stretching

    Science.gov (United States)

    Gillespie, Alan R.

    1992-01-01

    Decorrelation contrast stretching is an effective method for displaying information from multispectral thermal infrared (TIR) images. The technique involves transformation of the data to principle components ('decorrelation'), independent contrast 'stretching' of data from the new 'decorrelated' image bands, and retransformation of the stretched data back to the approximate original axes, based on the inverse of the principle component rotation. The enhancement is robust in that colors of the same scene components are similar in enhanced images of similar scenes, or the same scene imaged at different times. Decorrelation contrast stretching is reviewed in the context of other enhancements applied to TIR images.

  10. Systematic review of the safety and efficacy of contrast injection via venous catheters for contrast-enhanced computed tomography

    Directory of Open Access Journals (Sweden)

    S.B. Buijs

    Full Text Available Objective: To examine the safety and efficacy of contrast injection through a central venous catheter (CVC for contrast-enhanced computed tomography (CECT. Methods: A systematic literature search was performed using PubMed. Studies were deemed eligible if they reported on the use of CVCs for contrast administration. Selected articles were assessed for their relevance and risk of bias. Articles with low relevance and high risk of bias or both were excluded. Data from included articles was extracted. Results: Seven studies reported on the use of CVCs for contrast administration. Catheter rupture did not occur in any study. The incidence of dislocation ranged from 2.2-15.4%. Quality of scans was described in three studies, with less contrast enhancement of pulmonary arteries and the thoracic aorta in two studies, and average or above average quality in one study. Four other studies used higher flowrates, but did not report quality of scans. Conclusion: Contrast injection via CVCs can be performed safely for CECT when using a strict protocol. Quality of scans depended on multiple factors like flow rate, indication of the scan, and cardiac output of the patient. In each patient, an individual evaluation whether to use the CVC as access for contrast media should be made, while bolus tracking may be mandatory in most cases. Keywords: Central venous catheter, CVC, Contrast, Contrast-enhanced, CT-scan

  11. The cerebral intravascular enhancement sign is not specific: a contrast-enhanced MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Bakshi, R.; Kinkel, W.R.; Bates, V.E.; Mechtler, L.L.; Kinkel, P.R. [Lucy Dent Imaging Center, University at Buffalo, NY (United States)

    1999-02-01

    The intravascular enhancement (IVE) sign, also known as the ``arterial enhancement sign``, is an abnormal finding in the brain on contrast-enhanced MRI studies. IVE has been described in arterial cerebrovascular disorders, most commonly in acute or subacute arterial ischemic infarcts. However, the specificity of this sign has not been established. We describe four patients with disorders other than arterial strokes in whom gadolinium-enhanced high-field (1.5 T) MRI suggested IVE. The conditions were herpes simplex viral encephalitis, idiopathic cerebellitis, pneumococcal meningitis, and superior sagittal sinus thrombosis with venous infarction. IVE in these cases may be due to multiple factors, including arterial, venous, perivascular, and leptomeningeal or sulcal contrast medium accumulation. Our observations suggest that arterial ischemia, previously described as the cardinal cause of IVE, probably does not explain all instances, and urge caution in interpreting this sign as a specific MRI manifestation of acute arterial infarction or ischemia. (orig.) With 4 figs., 1 tab., 44 refs.

  12. Appropriate Contrast Enhancement Measures for Brain and Breast Cancer Images.

    Science.gov (United States)

    Gupta, Suneet; Porwal, Rabins

    2016-01-01

    Medical imaging systems often produce images that require enhancement, such as improving the image contrast as they are poor in contrast. Therefore, they must be enhanced before they are examined by medical professionals. This is necessary for proper diagnosis and subsequent treatment. We do have various enhancement algorithms which enhance the medical images to different extents. We also have various quantitative metrics or measures which evaluate the quality of an image. This paper suggests the most appropriate measures for two of the medical images, namely, brain cancer images and breast cancer images.

  13. Appropriate Contrast Enhancement Measures for Brain and Breast Cancer Images

    Directory of Open Access Journals (Sweden)

    Suneet Gupta

    2016-01-01

    Full Text Available Medical imaging systems often produce images that require enhancement, such as improving the image contrast as they are poor in contrast. Therefore, they must be enhanced before they are examined by medical professionals. This is necessary for proper diagnosis and subsequent treatment. We do have various enhancement algorithms which enhance the medical images to different extents. We also have various quantitative metrics or measures which evaluate the quality of an image. This paper suggests the most appropriate measures for two of the medical images, namely, brain cancer images and breast cancer images.

  14. NASA High Contrast Imaging for Exoplanets

    Science.gov (United States)

    Lyon, Richard G.

    2008-01-01

    Described is NASA's ongoing program for the detection and characterization of exosolar planets via high-contrast imaging. Some of the more promising proposed techniques under assessment may enable detection of life outside our solar system. In visible light terrestrial planets are approximately 10(exp -10) dimmer than the parent star. Issues such as diffraction, scatter, wavefront, amplitude and polarization all contribute to a reduction in contrast. An overview of the techniques will be discussed.

  15. Contrast-enhanced ultrasound: clinical applications in patients with atherosclerosis

    NARCIS (Netherlands)

    A.F.L. Schinkel (Arend); M. Kaspar (Mathias); D. Staub (Daniel)

    2016-01-01

    textabstractContrast-enhanced ultrasound (CEUS) is increasingly being used to evaluate patients with known or suspected atherosclerosis. The administration of a microbubble contrast agent in conjunction with ultrasound results in an improved image quality and provides information that cannot be

  16. Feature and Contrast Enhancement of Mammographic Image Based on Multiscale Analysis and Morphology

    Directory of Open Access Journals (Sweden)

    Shibin Wu

    2013-01-01

    Full Text Available A new algorithm for feature and contrast enhancement of mammographic images is proposed in this paper. The approach bases on multiscale transform and mathematical morphology. First of all, the Laplacian Gaussian pyramid operator is applied to transform the mammography into different scale subband images. In addition, the detail or high frequency subimages are equalized by contrast limited adaptive histogram equalization (CLAHE and low-pass subimages are processed by mathematical morphology. Finally, the enhanced image of feature and contrast is reconstructed from the Laplacian Gaussian pyramid coefficients modified at one or more levels by contrast limited adaptive histogram equalization and mathematical morphology, respectively. The enhanced image is processed by global nonlinear operator. The experimental results show that the presented algorithm is effective for feature and contrast enhancement of mammogram. The performance evaluation of the proposed algorithm is measured by contrast evaluation criterion for image, signal-noise-ratio (SNR, and contrast improvement index (CII.

  17. Feature and Contrast Enhancement of Mammographic Image Based on Multiscale Analysis and Morphology

    Science.gov (United States)

    Wu, Shibin; Xie, Yaoqin

    2013-01-01

    A new algorithm for feature and contrast enhancement of mammographic images is proposed in this paper. The approach bases on multiscale transform and mathematical morphology. First of all, the Laplacian Gaussian pyramid operator is applied to transform the mammography into different scale subband images. In addition, the detail or high frequency subimages are equalized by contrast limited adaptive histogram equalization (CLAHE) and low-pass subimages are processed by mathematical morphology. Finally, the enhanced image of feature and contrast is reconstructed from the Laplacian Gaussian pyramid coefficients modified at one or more levels by contrast limited adaptive histogram equalization and mathematical morphology, respectively. The enhanced image is processed by global nonlinear operator. The experimental results show that the presented algorithm is effective for feature and contrast enhancement of mammogram. The performance evaluation of the proposed algorithm is measured by contrast evaluation criterion for image, signal-noise-ratio (SNR), and contrast improvement index (CII). PMID:24416072

  18. Dose optimization of contrast-enhanced carotid MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Unterweger, M.; Froehlich, J.M.; Kubik-Huch, R.A.; Seifert, B.; Birrer, M.; Huber, T.; Otto, R. [Institute of Radiology, Cantonal Hospital Baden, Baden (Switzerland)

    2005-09-01

    The purpose of this work was to compare the diagnostic performance of a single-contrast or a double-contrast dose of carotid contrast-enhanced MR angiography (MRA). One-hundred nineteen patients (mean age 65{+-}14.4 years) underwent carotid contrast-enhanced MRA with a standardized protocol (repetition time/echo 3.73 ms/1.38 ms, flip-angle 25 , acquisition-time 19 s, voxel size 1.2 x 1.2 x 0.9 mm{sup 3}) on a 1.5-T scanner (Sonata, Siemens-Medical-Systems) using a neck phased-array coil. Contrast agent was administered intravenously at a rate of 3.0 ml/s, either as a single dose (n=57; 0.1 mmol/kg body weight) or as a double dose (n=62; 0.2 mmol/kg body weight) of meglumine gadoterate (0.5 M/l), followed by 30 ml saline. Qualitative image analysis was performed on maximum intensity projections using a five-point scale. Signal intensities were measured at three different vascular levels on both sides to assess the contrast-to-noise ratios (CNRs). Image quality was rated as good or excellent in all cases. A double dose did not influence the efficacy of carotid enhancement (CNR single dose 69.12{+-}19.8; CNR double dose 70.01{+-}20.7; p=0.81) compared with a single dose. In both dose groups the mean CNRs were inversely related to bodyweight, despite adjusted contrast volumes (p=0.0005). Double-dose contrast-enhanced carotid MRA is not superior to single-dose MRA, as overall diagnostic performance and quantitative contrast enhancement are equal. Being more cost-efficient, a single-dose administration of contrast agent is recommended for MRA of the carotid arteries. (orig.)

  19. Image fusion for dynamic contrast enhanced magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Leach Martin O

    2004-10-01

    Full Text Available Abstract 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.

  20. Visual Contrast Enhancement Algorithm Based on Histogram Equalization

    Directory of Open Access Journals (Sweden)

    Chih-Chung Ting

    2015-07-01

    Full Text Available Image enhancement techniques primarily improve the contrast of an image to lend it a better appearance. One of the popular enhancement methods is histogram equalization (HE because of its simplicity and effectiveness. However, it is rarely applied to consumer electronics products because it can cause excessive contrast enhancement and feature loss problems. These problems make the images processed by HE look unnatural and introduce unwanted artifacts in them. In this study, a visual contrast enhancement algorithm (VCEA based on HE is proposed. VCEA considers the requirements of the human visual perception in order to address the drawbacks of HE. It effectively solves the excessive contrast enhancement problem by adjusting the spaces between two adjacent gray values of the HE histogram. In addition, VCEA reduces the effects of the feature loss problem by using the obtained spaces. Furthermore, VCEA enhances the detailed textures of an image to generate an enhanced image with better visual quality. Experimental results show that images obtained by applying VCEA have higher contrast and are more suited to human visual perception than those processed by HE and other HE-based methods.

  1. Visual Contrast Enhancement Algorithm Based on Histogram Equalization

    Science.gov (United States)

    Ting, Chih-Chung; Wu, Bing-Fei; Chung, Meng-Liang; Chiu, Chung-Cheng; Wu, Ya-Ching

    2015-01-01

    Image enhancement techniques primarily improve the contrast of an image to lend it a better appearance. One of the popular enhancement methods is histogram equalization (HE) because of its simplicity and effectiveness. However, it is rarely applied to consumer electronics products because it can cause excessive contrast enhancement and feature loss problems. These problems make the images processed by HE look unnatural and introduce unwanted artifacts in them. In this study, a visual contrast enhancement algorithm (VCEA) based on HE is proposed. VCEA considers the requirements of the human visual perception in order to address the drawbacks of HE. It effectively solves the excessive contrast enhancement problem by adjusting the spaces between two adjacent gray values of the HE histogram. In addition, VCEA reduces the effects of the feature loss problem by using the obtained spaces. Furthermore, VCEA enhances the detailed textures of an image to generate an enhanced image with better visual quality. Experimental results show that images obtained by applying VCEA have higher contrast and are more suited to human visual perception than those processed by HE and other HE-based methods. PMID:26184219

  2. Quantitative flow phantom for contrast-enhanced breast tomosynthesis

    Science.gov (United States)

    Nock, Melissa L.; Kempston, Michael P.; Mainprize, James G.; Yaffe, Martin J.

    2007-03-01

    The use of contrast agents can help to overcome a lack of intrinsic radiographic contrast between malignant and benign breast tissue by taking advantage of the properties of tumour angiogenesis. Studies of contrast-enhanced mammography have demonstrated increased lesion conspicuity and have shown that this technique provides information on contrast uptake kinetics. It has been suggested that malignant and benign lesions can be differentiated in part by their uptake kinetics, so this additional data may lead to more accurate diagnoses. Tomosynthesis is a 3D x-ray imaging technique that permits lesion depth localization and increased conspicuity in comparison with 2D x-ray projection techniques. This modality, used in combination with contrast agents, promises to be a sensitive method of breast cancer detection. To develop the technique of contrast-enhanced breast tomosynthesis, a dynamic flow phantom has been constructed to provide the same types of imaging challenges anticipated in the clinical setting. These challenges include a low-contrast tumour space, relevant temporal contrast agent uptake and washout profiles, and a need for quantitative analysis of enhancement levels. The design of a flow phantom will be presented that includes a dynamic tumour space, a background that masks the tumour space in images without contrast enhancement, and flow characteristics that simulate tumour contrast agent uptake and washout kinetics. The system is calibrated to relate signal to concentration of the contrast agent using a well plate filled with iodinated water. Iodine detectability in the flow phantom is evaluated in terms of the signal-difference-to-noise ratio for various tomosynthesis image acquisition parameters including number of acquired angular views, angular extent, and reconstruction voxel size.

  3. Dynamic contrast enhanced magnetic resonance imaging in chronic Achilles tendinosis.

    Science.gov (United States)

    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. The dynamic MRI was evaluated in tendon, vessel and in fat ventrally of tendon. Area under the curve (AUC), time to peak of signal, signal increase per second (SI/s) and increase in signal between start and peak as a percentage (SI%) was calculated. Pain and performance were evaluated using a questionnaire. In the fat ventrally of the tendon, dynamic contrast enhancement was significantly higher in the symptomatic leg compared to the contralateral non-symptomatic leg before but not after treatment. Despite decreased pain and improved performance there was no significant change of dynamic contrast enhancement in symptomatic tendons after treatment. In Achilles tendinosis there is an increased contrast enhancement in the fat ventrally of the tendon. The lack of correlation with symptoms and the lack of significant changes in tendon contrast enhancement parameters do however indicate that dynamic enhanced MRI is currently not a useful method to evaluate chronic Achilles tendinosis.

  4. Human cerebral blood volume measurements using dynamic contrast enhancement in comparison to dynamic susceptibility contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Artzi, Moran [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Liberman, Gilad; Vitinshtein, Faina; Aizenstein, Orna [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Nadav, Guy [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Faculty of Engineering, Tel Aviv (Israel); Blumenthal, Deborah T.; Bokstein, Felix [Tel Aviv Sourasky Medical Center, Neuro-Oncology Service, Tel Aviv (Israel); Bashat, Dafna Ben [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv (Israel)

    2015-07-15

    Cerebral blood volume (CBV) is an important parameter for the assessment of brain tumors, usually obtained using dynamic susceptibility contrast (DSC) MRI. However, this method often suffers from low spatial resolution and high sensitivity to susceptibility artifacts and usually does not take into account the effect of tissue permeability. The plasma volume (v{sub p}) can also be extracted from dynamic contrast enhancement (DCE) MRI. The aim of this study was to investigate whether DCE can be used for the measurement of cerebral blood volume in place of DSC for the assessment of patients with brain tumors. Twenty-eight subjects (17 healthy subjects and 11 patients with glioblastoma) were scanned using DCE and DSC. v{sub p} and CBV values were measured and compared in different brain components in healthy subjects and in the tumor area in patients. Significant high correlations were detected between v{sub p} and CBV in healthy subjects in the different brain components; white matter, gray matter, and arteries, correlating with the known increased tissue vascularity, and within the tumor area in patients. This work proposes the use of DCE as an alternative method to DSC for the assessment of blood volume, given the advantages of its higher spatial resolution, its lower sensitivity to susceptibility artifacts, and its ability to provide additional information regarding tissue permeability. (orig.)

  5. Autoimmune pancreatitis: Assessment of the enhanced duct sign on multiphase contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Yuichi, E-mail: kawai.yuichi@a.mbox.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Suzuki, Kojiro, E-mail: kojiro@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Itoh, Shigeki, E-mail: shigeito@nagoya-1st.jrc.or.jp [Department of Diagnostic Radiology, Japan Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya 453-8511 (Japan); Takada, Akira, E-mail: takadaa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Mori, Yoshine, E-mail: yoshine@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Naganawa, Shinji, E-mail: naganawa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan)

    2012-11-15

    Purpose: To assess the usefulness of the computed tomography (CT) finding of main pancreatic duct (MPD) wall enhancement, termed the 'enhanced duct sign', for diagnosis of autoimmune pancreatitis (AIP) in comparison with diagnosis of pancreatic carcinoma and chronic pancreatitis. Materials and methods: Two radiologists independently evaluated the presence or absence of the enhanced duct sign on multiphase contrast-enhanced CT in patients with AIP (n = 55), pancreatic carcinoma (n = 50), and chronic pancreatitis (n = 50). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of AIP were calculated. In patients demonstrating the enhanced duct sign, additional findings were evaluated by consensus. Results: The enhanced duct sign was more frequently observed in patients with AIP (37/55, 67%) than in patients with pancreatic carcinoma (5/50, 10%) or chronic pancreatitis (0/50, 0%) (P < 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the finding were 0.67, 0.95, 0.85, 0.88, and 0.84, respectively. In AIP, the lumen within the enhanced duct was completely or partially invisible in 29 of 37 (78%) patients, and the enhanced duct was observed within the affected pancreatic parenchyma in 35 of 37 (95%) patients. In pancreatic carcinoma, the lumen within the enhanced duct was visible in all patients (5/5, 100%), and the enhanced duct was observed downstream of the tumor (5/5, 100%). Conclusion: The enhanced duct sign is highly specific of AIP.

  6. Contrast-enhanced CISS imaging of cerebellopontine angle tumors

    Energy Technology Data Exchange (ETDEWEB)

    Tozaki, Mitsuhiro; Toyoda, Keiko; Hata, Yuichi; Fukuda, Yasushi; Fukuda, Kunihiko [Jikei Univ., Tokyo (Japan). School of Medicine; Katano, Shuichi

    1999-10-01

    Our purpose of this study was to evaluate the clinical usefulness of contrast-enhanced CISS-3DFT MR imaging for the diagnosis of CP angle tumors. CISS-3DFT MR imaging is expected for screening procedure of acoustic schwannoma because of excellent spatial resolution. Recently, we discovered contrast enhancement effect on CISS sequence in spite of heavily T{sub 2}-weighted images. Fourteen patients with CP angle tumors were performed on a 1.0 T MR unit. Transaxial CISS-3DFT MRI was obtained both before and after intravenous injections of Gd-DTPA. Multiplanar reconstructions (MPRs) were performed in all cases. Contrast enhancement effect of CP angle tumors, and the relationship between tumors and the adjacent cranial nerves were evaluated. Contrast enhancement effect of the tumors was present in all cases in spite of heavily T{sub 2}-weighted images of CISS sequences. In the internal auditory canal, relationship between the tumors and the cranial nerves was demonstrated in 6 cases (6/9). In the cerebellopontine cistern, all cases were demonstrated (11/11). Contrast-enhanced CISS-3DFT MR imaging with a good contrast resolution and an excellent spatial resolution is useful for the diagnosis of CP angle tumors. (author)

  7. Dynamic-contrast-enhanced-MRI with extravasating contrast reagent: Rat cerebral glioma blood volume determination

    Science.gov (United States)

    Li, Xin; Rooney, William D.; Várallyay, Csanád G.; Gahramanov, Seymur; Muldoon, Leslie L.; Goodman, James A.; Tagge, Ian J.; Selzer, Audrey H.; Pike, Martin M.; Neuwelt, Edward A.; Springer, Charles S.

    2010-10-01

    The accurate mapping of the tumor blood volume (TBV) fraction ( vb) is a highly desired imaging biometric goal. It is commonly thought that achieving this is difficult, if not impossible, when small molecule contrast reagents (CRs) are used for the T1-weighted (Dynamic-Contrast-Enhanced) DCE-MRI technique. This is because angiogenic malignant tumor vessels allow facile CR extravasation. Here, a three-site equilibrium water exchange model is applied to DCE-MRI data from the cerebrally-implanted rat brain U87 glioma, a tumor exhibiting rapid CR extravasation. Analyses of segments of the (and the entire) DCE data time-course with this "shutter-speed" pharmacokinetic model, which admits finite water exchange kinetics, allow TBV estimation from the first-pass segment. Pairwise parameter determinances were tested with grid searches of 2D parametric error surfaces. Tumor blood volume ( vb), as well as ve (the extracellular, extravascular space volume fraction), and Ktrans (a CR extravasation rate measure) parametric maps are presented. The role of the Patlak Plot in DCE-MRI is also considered.

  8. Medial tibial pain: a dynamic contrast-enhanced MRI study.

    Science.gov (United States)

    Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

    1999-09-01

    The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

  9. Contrast-enhanced ultrasound for molecular imaging of angiogenesis.

    Science.gov (United States)

    Eisenbrey, J R; Forsberg, F

    2010-08-01

    Molecular imaging of angiogenesis using contrast-enhanced ultrasound allows for functional, real-time, inexpensive imaging of angiogenesis. The addition of stabilized microbubbles as contrast agents greatly improves ultrasound signal to noise ratio/signal strength/image quality (up to 25 dB) and allows for imaging of angiogenic vasculature. In this article recent advances in the usage of contrast-enhanced ultrasound for molecular imaging of angiogenesis are reviewed. The usage of commercially available agents and correlations between their imaging parameters and molecular markers of angiogenesis are reviewed. Recent developments in ultrasound contrast agents targeted to angiogenic markers for both diagnosis and monitoring are discussed. Finally, a brief overview of the emerging field of chemotherapeutic-loaded agents, which can be used with ultrasound-triggered drug delivery, is provided.

  10. BLIND CONTRAST ENHANCEMENT ASSESSMENT BY GRADIENT RATIOING AT VISIBLE EDGES

    Directory of Open Access Journals (Sweden)

    Nicolas Hautière

    2011-05-01

    Full Text Available The contrast of outdoor images acquired under adverse weather conditions, especially foggy weather, is altered by the scattering of daylight by atmospheric particles. As a consequence, differentmethods have been designed to restore the contrast of these images. However, there is a lack of methodology to assess the performances of the methods or to rate them. Unlike image quality assessment or image restoration areas, there is no easy way to have a reference image, which makes the problem not straightforward to solve. In this paper, an approach is proposed which consists in computing the ratio between the gradient of the visible edges between the image before and after contrast restoration. In this way, an indicator of visibility enhancement is provided based on the concept of visibility level, commonly used in lighting engineering. Finally, the methodology is applied to contrast enhancement assessment and to the comparison of tone-mapping operators.

  11. Contrast enhanced ultrasound in the assessment of urogenital pathology

    Directory of Open Access Journals (Sweden)

    Libero Barozzi

    2014-12-01

    Full Text Available Contrast enhanced ultrasound (CEUS is an innovative technique that employs microbubble contrast agents to demonstrate parenchymal perfusion. Although initial clinical application was focused on the liver pathology, a wide variety of clinical conditions can be assessed now with CEUS. CEUS is a well-tolerated technique and is acquiring an increasing role in the assessment of renal pathology because contrast agents are not excreted by the kidney and do not affect the renal function. CEUS demonstrated an accuracy similar to contrast enhanced multi-detector computed tomography (CEMDCT in detecting focal lesions, with the advantage of the real-time assessment of microvascular perfusion by using time-intensity curves. The aim of this paper is to review the main indications of CEUS in the assessment of renal and urogenital pathology. Imaging examples are presented and described. Advantages and limitations of CEUS with reference to conventional US and CE-MDCT are discussed.

  12. Homogenization of High-Contrast Brinkman Flows

    KAUST Repository

    Brown, Donald L.

    2015-04-16

    Modeling porous flow in complex media is a challenging problem. Not only is the problem inherently multiscale but, due to high contrast in permeability values, flow velocities may differ greatly throughout the medium. To avoid complicated interface conditions, the Brinkman model is often used for such flows [O. Iliev, R. Lazarov, and J. Willems, Multiscale Model. Simul., 9 (2011), pp. 1350--1372]. Instead of permeability variations and contrast being contained in the geometric media structure, this information is contained in a highly varying and high-contrast coefficient. In this work, we present two main contributions. First, we develop a novel homogenization procedure for the high-contrast Brinkman equations by constructing correctors and carefully estimating the residuals. Understanding the relationship between scales and contrast values is critical to obtaining useful estimates. Therefore, standard convergence-based homogenization techniques [G. A. Chechkin, A. L. Piatniski, and A. S. Shamev, Homogenization: Methods and Applications, Transl. Math. Monogr. 234, American Mathematical Society, Providence, RI, 2007, G. Allaire, SIAM J. Math. Anal., 23 (1992), pp. 1482--1518], although a powerful tool, are not applicable here. Our second point is that the Brinkman equations, in certain scaling regimes, are invariant under homogenization. Unlike in the case of Stokes-to-Darcy homogenization [D. Brown, P. Popov, and Y. Efendiev, GEM Int. J. Geomath., 2 (2011), pp. 281--305, E. Marusic-Paloka and A. Mikelic, Boll. Un. Mat. Ital. A (7), 10 (1996), pp. 661--671], the results presented here under certain velocity regimes yield a Brinkman-to-Brinkman upscaling that allows using a single software platform to compute on both microscales and macroscales. In this paper, we discuss the homogenized Brinkman equations. We derive auxiliary cell problems to build correctors and calculate effective coefficients for certain velocity regimes. Due to the boundary effects, we construct

  13. Multicenter surveillance of women at high genetic breast cancer risk using mammography, ultrasonography, and contrast-enhanced magnetic resonance imaging (the high breast cancer risk italian 1 study): final results.

    Science.gov (United States)

    Sardanelli, Francesco; Podo, Franca; Santoro, Filippo; Manoukian, Siranoush; Bergonzi, Silvana; Trecate, Giovanna; Vergnaghi, Daniele; Federico, Massimo; Cortesi, Laura; Corcione, Stefano; Morassut, Sandro; Di Maggio, Cosimo; Cilotti, Anna; Martincich, Laura; Calabrese, Massimo; Zuiani, Chiara; Preda, Lorenzo; Bonanni, Bernardo; Carbonaro, Luca A; Contegiacomo, Alma; Panizza, Pietro; Di Cesare, Ernesto; Savarese, Antonella; Crecco, Marcello; Turchetti, Daniela; Tonutti, Maura; Belli, Paolo; Maschio, Alessandro Del

    2011-02-01

    : To prospectively compare clinical breast examination, mammography, ultrasonography, and contrast-enhanced magnetic resonance imaging (MRI) in a multicenter surveillance of high-risk women. : We enrolled asymptomatic women aged ≥ 25: BRCA mutation carriers; first-degree relatives of BRCA mutation carriers, and women with strong family history of breast/ovarian cancer, including those with previous personal breast cancer. : A total of 18 centers enrolled 501 women and performed 1592 rounds (3.2 rounds/woman). Forty-nine screen-detected and 3 interval cancers were diagnosed: 44 invasive, 8 ductal carcinoma in situ; only 4 pT2 stage; 32 G3 grade. Of 39 patients explored for nodal status, 28 (72%) were negative. Incidence per year-woman resulted 3.3% overall, 2.1% mammography (50%), ultrasonography (52%), or mammography plus ultrasonography (63%) (P mammography (0.83) or ultrasonography (0.82) and not significantly increased when MRI was combined with mammography and/or ultrasonography. Of 52 cancers, 16 (31%) were diagnosed only by MRI, 8 of 21 (38%) in women mammography, ultrasonography, and their combination for screening high-risk women below and over 50.

  14. Quantitative Nonlinear Contrast-Enhanced Ultrasound of the Breast.

    Science.gov (United States)

    Sridharan, Anush; Eisenbrey, John R; Dave, Jaydev K; Forsberg, Flemming

    2016-08-01

    Breast cancer is the most frequent type of cancer among women (25% of all cancers). The angiogenic process that fuels the growth of tumors is a potential early indicator for differentiating between malignant and benign tumors. Recently, the use of microbubble-based contrast agents combined with ultrasound has allowed the development of contrast agent-specific imaging modes that provide visualization of tumor neovascularity. Contrast-enhanced Doppler, harmonic, and subharmonic imaging are some of the imaging modes that have been investigated for visualizing and quantifying the vascularity in breast tumors.

  15. Prolapsed cervical disc with diffuse contrast enhancement on CT

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Jun; Shinpo, Tomoyuki; Inoue, Kiyoharu; Shigeno, Taku; Ochiai, Chikayuki

    1985-04-01

    A 48-year-old woman with the C5/6 disc herniation was reported. She had noticed vague pains in the left shoulder a half year earlier. Neurological examination showed left lower cervical radicular pains and incomplete Brown-Sequard syndrome of the same side. The disc herniation was diagnosed by myelography and discography. On the CT examination, surprisingly, the prolapsed disc was homogenously enhanced after the administration of intravenous contrast medium. The vertebral angiography showed increased vascularity behind the C5/6 intervertebral space. At operation, a prolapsed nucleus pulposus with proliferated connective tissue was found and curetted. The etiology of contrast enhancement was discussed.

  16. Microbubble contrast-enhanced ultrasound in liver transplantation.

    Science.gov (United States)

    Berry, Jonathan D; Sidhu, Paul S

    2004-10-01

    The use of liver transplantation for treatment of end-stage liver disease is now commonplace. The accurate assessment of the pre-transplant candidate and long-term follow-up of the posttransplant patient is vital in ensuring that the limited resource of donor livers is appropriately used. Ultrasound is accepted as playing an important role in this process. The advent of microbubble contrast enhanced ultrasound provides new opportunities in terms of improving diagnostic accuracy and obviating more invasive investigations with their associated patient morbidity and mortality. We present the current and developing applications of microbubble contrast-enhanced ultrasound in the field of liver transplantation.

  17. High-index-contrast subwavelength grating VCSEL

    DEFF Research Database (Denmark)

    Gilet, Philippe; Olivier, Nicolas; Grosse, Philippe

    2010-01-01

    In this article, we report our results on 980nm high-index-contrast subwavelength grating (HCG) VCSELs for optical interconnection applications. In our structure, a thin undoped HCG layer replaces a thick p-type Bragg mirror. The HCG mirror can feasibly achieve polarization-selective reflectivities...... structures. These results build a bridge between a standard VCSEL and a hybrid laser on silicon, making them of potential use for the realization of silicon photonics....

  18. 1550 nm high contrast grating VCSEL.

    Science.gov (United States)

    Chase, Christopher; Rao, Yi; Hofmann, Werner; Chang-Hasnain, Connie J

    2010-07-19

    We demonstrate an electrically pumped high contrast grating (HCG) VCSEL operating at 1550 nm incorporating a proton implant-defined aperture. Output powers of >1 mW are obtained at room temperature under continuous wave operation. Devices operate continuous wave at temperatures exceeding 60 degrees C. The novel device design, which is grown in a single epitaxy step, may enable lower cost long wavelength VCSELs.

  19. Contrast Enhancement of Mammograms for Rapid Detection of Microcalcification Clusters

    Directory of Open Access Journals (Sweden)

    Hajar Moradmand

    2014-08-01

    Full Text Available Introduction Breast cancer is one of the most common types of cancer among women.  Early detection of breast cancer is the key to reducing the associated mortality rate. The presence of microcalcifications clusters (MCCs is one of the earliest signs of breast cancer. Due to poor imaging contrast of mammograms and noise contamination, radiologists may overlook some diagnostic signs, specially the presence of MCCs. In order to improve cancer detection, image enhancement methods are often used to aid radiologists. In this paper, a new enhancement method was presented for the accurate and early detection of MCCs in mammograms. Materials and Methods The proposed system consisted of four main steps including: 1 image scaling;2 breast region segmentation;3 noise cancellation using a filter, which is sensitive to MCCs; and 4 contrast enhancement of mammograms using Contrast-Limited Adaptive Histogram Equalization (CLAHE and wavelet transform. To evaluate this method, 120 clinical mammograms were used. Results To evaluate the performance of the image enhancement algorithm, contrast improvement index (CII was used. The proposed enhancement method in this research achieved the highest CII in comparison with other methods applied in this study. The Validity of the results was confirmed by an expert radiologist through visual inspection. Conclusion Detection of MCCs significantly improved in contrast-enhanced mammograms. The proposed method could be helpful for radiologists to easily detect MCCs; it could also decrease the number of biopsies and reduce the frequency of clinical misdiagnosis. Moreover, it could be useful prior to segmentation or classification stages.

  20. Adaptive radiotherapy based on contrast enhanced cone beam CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Soevik, Aaste; Skogmo, Hege K. (Dept. of Companion Animal Clinical Sciences, Norwegian School of Veterinary Science, Oslo (Norway)), E-mail: aste.sovik@nvh.no; Roedal, Jan (Dept. of Companion Animal Clinical Sciences, Norwegian School of Veterinary Science, Oslo (Norway)); Lervaag, Christoffer; Eilertsen, Karsten; Malinen, Eirik (Dept. of Medical Physics, The Norwegian Radium Hospital, Oslo Univ. Hospital, Oslo (Norway))

    2010-10-15

    Cone beam CT (CBCT) imaging has become an integral part of radiation therapy, with images typically used for offline or online patient setup corrections based on bony anatomy co-registration. Ideally, the co-registration should be based on tumor localization. However, soft tissue contrast in CBCT images may be limited. In the present work, contrast enhanced CBCT (CECBCT) images were used for tumor visualization and treatment adaptation. Material and methods. A spontaneous canine maxillary tumor was subjected to repeated cone beam CT imaging during fractionated radiotherapy (10 fractions in total). At five of the treatment fractions, CECBCT images, employing an iodinated contrast agent, were acquired, as well as pre-contrast CBCT images. The tumor was clearly visible in post-contrast minus pre-contrast subtraction images, and these contrast images were used to delineate gross tumor volumes. IMRT dose plans were subsequently generated. Four different strategies were explored: 1) fully adapted planning based on each CECBCT image series, 2) planning based on images acquired at the first treatment fraction and patient repositioning following bony anatomy co-registration, 3) as for 2), but with patient repositioning based on co-registering contrast images, and 4) a strategy with no patient repositioning or treatment adaptation. The equivalent uniform dose (EUD) and tumor control probability (TCP) calculations to estimate treatment outcome for each strategy. Results. Similar translation vectors were found when bony anatomy and contrast enhancement co-registration were compared. Strategy 1 gave EUDs closest to the prescription dose and the highest TCP. Strategies 2 and 3 gave EUDs and TCPs close to that of strategy 1, with strategy 3 being slightly better than strategy 2. Even greater benefits from strategies 1 and 3 are expected with increasing tumor movement or deformation during treatment. The non-adaptive strategy 4 was clearly inferior to all three adaptive strategies

  1. Non-mass-like enhancement on contrast-enhanced breast MR imaging: lesion characterization using combination of dynamic contrast-enhanced and diffusion-weighted MR images.

    Science.gov (United States)

    Yabuuchi, Hidetake; Matsuo, Yoshio; Kamitani, Takeshi; Setoguchi, Taro; Okafuji, Takashi; Soeda, Hiroyasu; Sakai, Shuji; Hatakenaka, Masamitsu; Kubo, Makoto; Tokunaga, Eriko; Yamamoto, Hidetaka; Honda, Hiroshi

    2010-07-01

    To evaluate the diagnostic accuracy of a combination of dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted MR imaging (DWI) in characterization of lesions showing non-mass-like enhancement on breast MR imaging and to find the strongest discriminators between carcinoma and benignancy. We analyzed consecutive MR images in 45 lesions showing non-mass like enhancement in 41 patients. We analyzed lesion size, distribution, internal enhancement, kinetic curve pattern, and apparent diffusion coefficient (ADC) values. We applied univariate and multivariate analyses to find the strongest indicators for malignancy. In a validation study, 22 non-mass-like enhancement lesions in 21 patients were examined. We calculated diagnostic accuracy when we presume category 4b, 4c, and 5 lesions as malignant or high to moderate suspicion for malignancy, and category 4a and 3 as low suspicion for malignancy or benign. Segmental distribution (P=0.018), clumped internal enhancement (P=0.005), and ADC less than 1.3 x 10(-3) mm(2)/s (P=0.047) were the strongest MR indicators of malignancy. In a validation study, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 87% (13/15), 86% (6/7), 93% (13/14), 75% (6/8) and 86% (19/22), respectively. The combination of DCE-MRI and DWI showed high diagnostic accuracy in characterization of non-mass-like enhancement lesions on breast MR images. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  2. First Bloch eigenvalue in high contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Briane, Marc, E-mail: mbriane@insa-rennes.fr [Institut de Recherche Mathématique de Rennes, INSA de Rennes (France); Vanninathan, Muthusamy, E-mail: vanni@math.tifrbng.res.in [TIFR-CAM, Bangalore (India)

    2014-01-15

    This paper deals with the asymptotic behavior of the first Bloch eigenvalue in a heterogeneous medium with a high contrast εY-periodic conductivity. When the conductivity is bounded in L{sup 1} and the constant of the Poincaré-Wirtinger weighted by the conductivity is very small with respect to ε{sup −2}, the first Bloch eigenvalue converges as ε → 0 to a limit which preserves the second-order expansion with respect to the Bloch parameter. In dimension two the expansion of the limit can be improved until the fourth-order under the same hypotheses. On the contrary, in dimension three a fibers reinforced medium combined with a L{sup 1}-unbounded conductivity leads us to a discontinuity of the limit first Bloch eigenvalue as the Bloch parameter tends to zero but remains not orthogonal to the direction of the fibers. Therefore, the high contrast conductivity of the microstructure induces an anomalous effect, since for a given low-contrast conductivity the first Bloch eigenvalue is known to be analytic with respect to the Bloch parameter around zero.

  3. Contrast enhanced imaging with a stationary digital breast tomosynthesis system

    Science.gov (United States)

    Puett, Connor; Calliste, Jabari; Wu, Gongting; Inscoe, Christina R.; Lee, Yueh Z.; Zhou, Otto; Lu, Jianping

    2017-03-01

    Digital breast tomosynthesis (DBT) captures some depth information and thereby improves the conspicuity of breast lesions, compared to standard mammography. Using contrast during DBT may also help distinguish malignant from benign sites. However, adequate visualization of the low iodine signal requires a subtraction step to remove background signal and increase lesion contrast. Additionally, attention to factors that limit contrast, including scatter, noise, and artifact, are important during the image acquisition and post-acquisition processing steps. Stationary DBT (sDBT) is an emerging technology that offers a higher spatial and temporal resolution than conventional DBT. This phantom-based study explored contrast-enhanced sDBT (CE sDBT) across a range of clinically-appropriate iodine concentrations, lesion sizes, and breast thicknesses. The protocol included an effective scatter correction method and an iterative reconstruction technique that is unique to the sDBT system. The study demonstrated the ability of this CE sDBT system to collect projection images adequate for both temporal subtraction (TS) and dual-energy subtraction (DES). Additionally, the reconstruction approach preserved the improved contrast-to-noise ratio (CNR) achieved in the subtraction step. Finally, scatter correction increased the iodine signal and CNR of iodine-containing regions in projection views and reconstructed image slices during both TS and DES. These findings support the ongoing study of sDBT as a potentially useful tool for contrast-enhanced breast imaging and also highlight the significant effect that scatter has on image quality during DBT.

  4. Efficient contrast enhancement through log-power histogram modification

    NARCIS (Netherlands)

    Wu, T.; Toet, A.

    2014-01-01

    A simple power-logarithm histogram modification operator is proposed to enhance digital image contrast. First a logarithm operator reduces the effect of spikes and transforms the image histogram into a smoothed one that approximates a uniform histogram while retaining the relative size ordering of

  5. Sentinel node detection in melanomas using contrast-enhanced ultrasound

    DEFF Research Database (Denmark)

    Nielsen, K. Rue; Klyver, H.; Chakera, A. Hougaard

    2009-01-01

    BACKGROUND: Sentinel node (SN) biopsy has proven to be a useful clinical method based on the combination of radionuclide tracer principles and the dye technique. Contrast-enhanced ultrasound (CEUS) has been used successfully for detection of SN in animals, but the use of CEUS has not been reported...

  6. Contrast-enhanced endoscopic ultrasonography: advance and current status

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Sung Il [Dept. of Internal Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of); Lee, Dong Ki [Dept. of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2014-10-15

    Endoscopic ultrasonography (EUS) technology has undergone a great deal of progress along with the color and power Doppler imaging, three-dimensional imaging, electronic scanning, tissue harmonic imaging, and elastography, and one of the most important developments is the ability to acquire contrast-enhanced images. The blood flow in small vessels and the parenchymal microvasculature of the target lesion can be observed non-invasively by contrast-enhanced EUS (CE-EUS). Through a hemodynamic analysis, CE-EUS permits the diagnosis of various gastrointestinal diseases and differential diagnoses between benign and malignant tumors. Recently, mechanical innovations and the development of contrast agents have increased the use of CE-EUS in the diagnostic field, as well as for the assessment of the efficacy of therapeutic agents. The advances in and the current status of CE-EUS are discussed in this review.

  7. The advantage of high relaxivity contrast agents in brain perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, F. [MRI Center, Centre Hospitalier Lyon Sud, Pierre Benite (France); CREATIS, INSA-502, Villeurbanne (France); Lab. d' Anatomie, UFR Laennec, Lyon (France); Hermier, M. [CREATIS, INSA-502, Villeurbanne (France); MRI Center, Neurologic Hospital, Lyon (France)

    2006-01-10

    Accurate MRI characterization of brain lesions is critical for planning therapeutic strategy, assessing prognosis and monitoring response to therapy. Conventional MRI with gadolinium-based contrast agents is useful for the evaluation of brain lesions, but this approach primarily depicts areas of disruption of the blood-brain barrier (BBB) rather than tissue perfusion. Advanced MR imaging techniques such as dynamic contrast agent-enhanced perfusion MRI provide physiological information that complements the anatomic data available from conventional MRI. We evaluated brain perfusion imaging with gadobenate dimeglumine (Gd-BOPTA, MultiHance; Bracco Imaging, Milan, Italy). The contrast-enhanced perfusion technique was performed on a Philips Intera 1.5-T MR system. The technique used to obtain perfusion images was dynamic susceptibility contrast-enhanced MRI, which is highly sensitive to T2* changes. Combined with PRESTO perfusion imaging, SENSE is applied to double the temporal resolution, thereby improving the signal intensity curve fit and, accordingly, the accuracy of the derived parametric images. MultiHance is the first gadolinium MR contrast agent with significantly higher T1 and T2 relaxivities than conventional MR contrast agents. The higher T1 relaxivity, and therefore better contrast-enhanced T1-weighted imaging, leads to significantly improved detection of BBB breakdown and hence improved brain tumor conspicuity and delineation. The higher T2 relaxivity allows high-quality T2*-weighted perfusion MRI and the derivation of good quality relative cerebral blood volume (rCBV) maps. We determined the value of MultiHance for enhanced T2*-weighted perfusion imaging of histologically proven (by surgery or stereotaxic biopsy) intraaxial brain tumors (n=80), multiple sclerosis lesions (n=10), abscesses (n=4), neurolupus (n=15) and stroke (n=16). All the procedures carried out were safe and no adverse events occurred. The acquired perfusion images were of good quality in

  8. Medical Image Visual Appearance Improvement Using Bihistogram Bezier Curve Contrast Enhancement: Data from the Osteoarthritis Initiative

    National Research Council Canada - National Science Library

    Gan, Hong-Seng; Swee, Tan Tian; Abdul Karim, Ahmad Helmy; Sayuti, Khairil Amir; Abdul Kadir, Mohammed Rafiq; Tham, Weng-Kit; Wong, Liang-Xuan; Chaudhary, Kashif T; Ali, Jalil; Yupapin, Preecha P

    2014-01-01

    .... In this work, the proposed bihistogram Bezier curve contrast enhancement introduces the concept of "adequate contrast enhancement" to overcome sudden jump problem in knee magnetic resonance image...

  9. The Application of Contrast Enhanced Ultrasound in Molecular Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hak Jong; Chung, Jin Haeung; Hwang, Sung Il [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2009-09-15

    Microbubble contrast agent for ultrasound imaging has come of age, adding entirely new capabilities to real time ultrasound imaging. These new ultrasound imaging techniques exploit the nonlinear echoes that result from the unique interaction between ultrasound and microbubbles, which are readily distinguishable from the echoes of tissues. Contrast enhanced ultrasound can be used to quantify both flow rate and relative vascular volume of the microvasculature in solid lesions or organs, which makes it possible for it to be one of the modalities in molecular imaging. Angiogenesis is one of the important processes contributing to new blood vessel growth that occurs in a variety of physiologic and pathophysiologic states. It is essential for spread and growth of malignant tumors. The advantages of contrast enhanced ultrasound are that it is a noninvasive method for observing tumor angiogenesis. Sonoporation utilizes the interaction of ultrasound with ultrasound contrast agents to temporarily permeabilized the cell membrane allowing for the uptake of DNA, drugs, and other therapeutic compounds from the extracellular environment. Thus, sonoporation is a promising drug delivery and gene therapy technique, limited only by lack of understanding regarding the biophysical mechanism that results in the cell membrane permeability change. In conclusion, ultrasound contrast agent could have a role not only in the molecular imaging field with the advantage of noninvasive quantification of angiogenesis, but also in the field of drug treatment of cells using sonoporation

  10. Diagnosis of subdural haematoma by computed axial tomography: use of xenon inhalation for contrast enhancement.

    Science.gov (United States)

    Zilkha, E; Kendall, B E; Loh, L; Hayward, R; Radue, E W; ingram, G S

    1978-01-01

    A subdural haematoma is described in which a definite computed tomographic (CT) scan diagnosis was made only after contrast enhancement had been achieved by the inhalation of xenon. The different types of enhancement obtained with iodide containing contrast media and with xenon are discussed. The use of xenon to obtain further information in conditions which are inadequately elucidated by conventional CT must be balanced against its anaesthetic effects and relatively high cost. Images PMID:650246

  11. Pancreatic splenosis demonstrated by contrast-enhanced sonography.

    Science.gov (United States)

    Rogers, Patrick; Williams, M P; Fernando, Rashika; Freeman, Simon

    2011-07-01

    Pancreatic splenosis is a very rare condition whose features on contrast-enhanced ultrasound (CEUS) have not, to our knowledge, been previously reported. We present the imaging findings in a case of pancreatic splenosis, in which a confident diagnosis was achieved with the use of CEUS and confirmed by a labeled heat denatured red cell scan. Accumulation of ultrasound contrast microbubbles in splenic tissue can be readily visualized on late-phase CEUS and this technique has already been used to confirm the nature of intrapancreatic accessory spleens. This case shows that it can also confirm the diagnosis of splenosis. Copyright © 2011 Wiley Periodicals, Inc.

  12. Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound

    Directory of Open Access Journals (Sweden)

    John R. Eisenbrey

    2015-01-01

    Full Text Available Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency, subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imaging in vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

  13. Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound.

    Science.gov (United States)

    Eisenbrey, John R; Sridharan, Anush; Liu, Ji-Bin; Forsberg, Flemming

    2015-01-01

    Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency), subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imaging in vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

  14. Artifacts in contrast-enhanced ultrasound: a pictorial essay.

    Science.gov (United States)

    Fetzer, David T; Rafailidis, Vasileios; Peterson, Cynthia; Grant, Edward G; Sidhu, Paul; Barr, Richard G

    2017-12-02

    Although contrast-enhanced ultrasound (CEUS) has become a widely utilized and accepted modality in much of the world, the associated contrast agents have only recently received approval in the United States. As with all radiological techniques, image artifacts are encountered in CEUS, some of which relate to commonly encountered ultrasound artifacts, while others are unique to this technique. Image artifacts must be recognized when performing and interpreting examinations to improve technique and diagnostic accuracy. In this article, we review artifacts that may be encountered in CEUS, and where possible discuss how to minimize them or mitigate their effect on image quality and interpretation.

  15. Contrast-enhanced Ultrasound for Non-tumor Liver Diseases

    Directory of Open Access Journals (Sweden)

    H Maruyama

    2012-03-01

    Full Text Available Contrast-enhanced ultrasound (CEUS is a simple, safe and reliable technique for the clinical management of patients with various liver diseases. Although the major target of the technique may be focal hepatic lesions, it is also effective for the diagnosis of non-tumor liver diseases, such as grading hepatic fibrosis, characterization of chronic liver diseases and diagnosis of portal vein thrombosis. This review article aimed to overview the recent application of CEUS in the assessment of non-tumor liver diseases. Keywords: Cirrhosis, contrast agent, fibrosis, idiopathic portal hypertension, microbubble, portal vein thrombosis, ultrasound.

  16. TMJ disorders and pain: Assessment by contrast-enhanced MRI

    Energy Technology Data Exchange (ETDEWEB)

    Farina, Davide [Department of Radiology (School of Medicine), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy)], E-mail: nappaje@yahoo.it; Bodin, Christiane [Division of Gnathology (School of Dentistry), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); Gandolfi, Silvia [Department of Radiology (School of Medicine), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); De Gasperi, Werner [Division of Gnathology (School of Dentistry), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); Borghesi, Andrea; Maroldi, Roberto [Department of Radiology (School of Medicine), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy)

    2009-04-15

    Though magnetic resonance (MRI) is a widely accepted standard for the assessment of patients with temporomandibular joint (TMJ) disorders, efforts to correlate symptoms to MRI findings have often given controversial results. Aim of this study was to investigate the correlation between TMJ pain and findings of contrast-enhanced MRI. Thirty-eight consecutive patients with TMJ dysfunction syndrome (study group) were examined with MRI. Protocol included T2 turbo spin-echo sequence, T1 spin-echo sequence, and T2 gradient-echo (acquired with closed jaw, at intermediate and maximal opening). Post-contrast phase was obtained through a fat sat 3D T1 gradient-echo sequence (VIBE). Post-contrast findings in the study group were matched with those obtained in a control group of 33 patients submitted to MRI of the paranasal sinuses. Statistically significant difference was found between condylar medullary bone enhancement in painful TMJ, in painless TMJ and control group. In addition the average thickness of joint soft tissue enhancement in painful TMJ was superior to painless TMJ (p < 0.0001) and to control group. On multivariate logistic regression analysis, the odds ratio that a painful TMJ showed disk displacement, osteoarthrosis, effusion and JST enhancement were 3.05, 3.18, 1.2 and 11.36, respectively. Though not histologically proven, TMJ enhancement could reflect the presence of inflammation in painful joints. Furthermore, the administration of contrast could be of help for the assessment of patients with orofacial pain, particularly when clinical exploration is insufficient to ascribe the pain to TMJ.

  17. Halftoning for high-contrast imaging

    Directory of Open Access Journals (Sweden)

    Kasper M.

    2011-07-01

    Full Text Available High-contrast instruments, such as SPHERE (upcoming planet finder instrument for the ESO-VLT, or EPICS (planet hunter project for the future E-ELT, will require customized components with spatially varying transmission (e.g. coronagraphs, optical components that reduce the contrast between a companion and its parent star. The goal of these sub-systems is to control the spatial transmission, either in a pupil plane (pupil apodization, or in a focal plane of the instrument (occulting mask, i.e. low-frequency filter. Reliably producing components with spatially varying transmission is not trivial, and different techniques have been already investigated for application to astronomy (e.g. metal deposition with spatially-varying thickness, or high-energy beam sensitive glass using e-beam lithography. We present some results related to the recent development of components with spatially varying transmission using a relatively simple technique analogous to the digital halftoning process used for printing applications.

  18. A new hardware-efficient algorithm and reconfigurable architecture for image contrast enhancement.

    Science.gov (United States)

    Huang, Shih-Chia; Chen, Wen-Chieh

    2014-10-01

    Contrast enhancement is crucial when generating high quality images for image processing applications, such as digital image or video photography, liquid crystal display processing, and medical image analysis. In order to achieve real-time performance for high-definition video applications, it is necessary to design efficient contrast enhancement hardware architecture to meet the needs of real-time processing. In this paper, we propose a novel hardware-oriented contrast enhancement algorithm which can be implemented effectively for hardware design. In order to be considered for hardware implementation, approximation techniques are proposed to reduce these complex computations during performance of the contrast enhancement algorithm. The proposed hardware-oriented contrast enhancement algorithm achieves good image quality by measuring the results of qualitative and quantitative analyzes. To decrease hardware cost and improve hardware utilization for real-time performance, a reduction in circuit area is proposed through use of parameter-controlled reconfigurable architecture. The experiment results show that the proposed hardware-oriented contrast enhancement algorithm can provide an average frame rate of 48.23 frames/s at high definition resolution 1920 × 1080.

  19. Phase contrast imaging with coherent high energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Snigireva, I. [ESRF, Grenoble (France)

    1997-02-01

    X-ray imaging concern high energy domain (>6 keV) like a contact radiography, projection microscopy and tomography is used for many years to discern the features of the internal structure non destructively in material science, medicine and biology. In so doing the main contrast formation is absorption that makes some limitations for imaging of the light density materials and what is more the resolution of these techniques is not better than 10-100 {mu}m. It was turned out that there is now way in which to overcome 1{mu}m or even sub-{mu}m resolution limit except phase contrast imaging. It is well known in optics that the phase contrast is realised when interference between reference wave front and transmitted through the sample take place. Examples of this imaging are: phase contrast microscopy suggested by Zernike and Gabor (in-line) holography. Both of this techniques: phase contrast x-ray microscopy and holography are successfully progressing now in soft x-ray region. For imaging in the hard X-rays to enhance the contrast and to be able to resolve phase variations across the beam the high degree of the time and more importantly spatial coherence is needed. Because of this it was reasonable that the perfect crystal optics was involved like Bonse-Hart interferometry, double-crystal and even triple-crystal set-up using Laue and Bragg geometry with asymmetrically cut crystals.

  20. Contrast-Enhanced Sonography for Diagnosing Collateral Transformation of the Hepatic Artery After Liver Transplantation.

    Science.gov (United States)

    Lyu, Su-Qin; Ren, Jie; Zheng, Rong-Qin; Meng, Xiao-Chun; Huang, Ming-Sheng; Wang, Ping

    2015-09-01

    To determine the contrast-enhanced sonographic features of hepatic artery collateral transformation in patients with hepatic artery complications after liver transplantation. Ninety-nine liver transplant recipients who underwent contrast-enhanced sonography were recruited from April 2004 to May 2014. The reference standards were conventional angiography and computed tomographic angiography. The contrast-enhanced sonographic features of the hepatic artery in patients with and without collateral arteries were retrospectively analyzed. All 15 patients with hepatic artery collateral transformation had hepatic artery thrombosis (10 of 15) or hepatic artery stenosis (5 of 15). The collateral artery detection rate on contrast-enhanced sonography was 100%. The peripheral hepatic artery could not be visualized by contrast-enhanced sonography in most of the patients with hepatic artery collateral transformation (14 of 15). Additionally, many small tortuous collateral arteries in the porta hepatis region were visualized during the arterial and early portal phases, showing reticulated/patchy (15 of 15) and striped (3 of 15) enhancement patterns on contrast-enhanced sonography. Collateral transformation of the hepatic artery in patients with hepatic artery complications after liver transplantation appears to have characteristic features on contrast-enhanced sonography, especially a reticulated or patchy enhancement pattern in the porta hepatis region during the arterial and early portal phases combined with the absence of the peripheral hepatic artery. Contrast-enhanced sonography may be a novel method for diagnosing hepatic artery collateral transformation, which may be a highly specific sign of hepatic artery thrombosis or stenosis. © 2015 by the American Institute of Ultrasound in Medicine.

  1. Comparison between breast MRI and contrast-enhanced spectral mammography.

    Science.gov (United States)

    Łuczyńska, Elżbieta; Heinze-Paluchowska, Sylwia; Hendrick, Edward; Dyczek, Sonia; Ryś, Janusz; Herman, Krzysztof; Blecharz, Paweł; Jakubowicz, Jerzy

    2015-05-12

    The main goal of this study was to compare contrast-enhanced spectral mammography (CESM) and breast magnetic resonance imaging (MRI) with histopathological results and to compare the sensitivity, accuracy, and positive and negative predictive values for both imaging modalities. After ethics approval, CESM and MRI examinations were performed in 102 patients who had suspicious lesions described in conventional mammography. All visible lesions were evaluated independently by 2 experienced radiologists using BI-RADS classifications (scale 1-5). Dimensions of lesions measured with each modality were compared to postoperative histopathology results. There were 102 patients entered into CESM/MRI studies and 118 lesions were identified by the combination of CESM and breast MRI. Histopathology confirmed that 81 of 118 lesions were malignant and 37 were benign. Of the 81 malignant lesions, 72 were invasive cancers and 9 were in situ cancers. Sensitivity was 100% with CESM and 93% with breast MRI. Accuracy was 79% with CESM and 73% with breast MRI. ROC curve areas based on BI-RADS were 0.83 for CESM and 0.84 for breast MRI. Lesion size estimates on CESM and breast MRI were similar, both slightly larger than those from histopathology. Our results indicate that CESM has the potential to be a valuable diagnostic method that enables accurate detection of malignant breast lesions, has high negative predictive value, and a false-positive rate similar to that of breast MRI.

  2. FDG-PET/contrast-enhanced CT as a post-treatment tool in head and neck squamous cell carcinoma: comparison with FDG-PET/non-contrast-enhanced CT and contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Suenaga, Yuko; Kitajima, Kazuhiro; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Ishihara, Takeaki; Sasaki, Ryohei [Kobe University Graduate, School of Medicine, Department of Radiology, Division of Radiation Oncology, Kobe (Japan); Otsuki, Naoki; Nibu, Ken-ichi [Kobe University Graduate, School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Kobe (Japan); Minamikawa, Tsutomu [Kobe University Graduate School of Medicine, Department of Oral and Maxillofacial Surgery, Kobe (Japan); Kiyota, Naomi [Kobe University Hospital, Department of Medical Oncology and Hematology, Kobe (Japan)

    2016-04-15

    To evaluate the accuracy of PET/CT using {sup 18}F-fluorodeoxyglucose (FDG) with IV contrast for suspected recurrent head and neck squamous cell carcinoma (HNSCC). One hundred and seventy patients previously treated for HNSCC underwent PET/CT, consisting of non-contrast-enhanced and contrast-enhanced CT, to investigate suspected recurrence. Diagnostic performance of PET/contrast-enhanced CT (PET/ceCT), PET/non-contrast-enhanced CT (PET/ncCT) and contrast-enhanced CT (ceCT) for local or regional recurrence, distant metastasis, overall recurrence and second primary cancer was evaluated. The reference standard included histopathology, treatment change and imaging follow-up. The patient-based areas under the receiver operating characteristic curves (AUC) for ceCT, PET/ncCT and PET/ceCT were 0.82, 0.96 and 0.98 for local recurrence, 0.73, 0.86 and 0.86 for regional recurrence, 0.86, 0.91 and 0.92 for distant metastasis, 0.72, 0.86 and 0.87 for overall recurrence, and 0.86, 0.89 and 0.91 for a second primary cancer. Both PET/ceCT and PET/ncCT statistically showed larger AUC than ceCT for recurrence, and the difference between PET/ceCT and PET/ncCT for local recurrence reached a significant level (p = 0.039). The accuracy of PET/ceCT for diagnosing overall recurrence was high, irrespective of the time interval after the last treatment (83.3-94.1 %). FDG-PET/CT was a more accurate HNSCC restaging tool than ceCT. The added value of ceCT at FDG-PET/CT is minimal. (orig.)

  3. A fuzzy approach for contrast enhancement of mammography breast images.

    Science.gov (United States)

    Sahba, Farhang; Venetsanopoulos, Anastasios

    2010-01-01

    This chapter presents a fuzzy-based method for contrast enhancement of mammography images. The selection of appropriate parameters for the required transformations is performed based on image-specific characteristics. The extraction of the breast border is the first step in this method. Images are then transformed to the fuzzy domain using a specific function. Next, an algorithm is applied for intensity adaptation where based on the amount of ambiguity, the proposed technique identifies the suitable form of modifications to enhance the image. Experimental results prove our method to be effective and hence of potential for use in computer-aided diagnosis systems.

  4. Characterizing EPR-mediated passive drug targeting using contrast-enhanced functional ultrasound imaging

    NARCIS (Netherlands)

    Theek, B.; Gremse, F.; Kunjachan, S.; Fokong, S.; Pola, R.; Pechar, M.; Deckers, R.; Storm, Gerrit; Ehling, J.; Kiessling, F.; Lammers, Twan Gerardus Gertudis Maria

    2014-01-01

    The Enhanced Permeability and Retention (EPR) effect is extensively used in drug delivery research. Taking into account that EPR is a highly variable phenomenon, we have here set out to evaluate if contrast-enhanced functional ultrasound (ceUS) imaging can be employed to characterize EPR-mediated

  5. Vascular applications of contrast-enhanced ultrasound imaging.

    Science.gov (United States)

    Mehta, Kunal S; Lee, Jake J; Taha, Ashraf A; Avgerinos, Efthymios; Chaer, Rabih A

    2017-07-01

    Contrast-enhanced ultrasound (CEUS) imaging is a powerful noninvasive modality offering numerous potential diagnostic and therapeutic applications in vascular medicine. CEUS imaging uses microbubble contrast agents composed of an encapsulating shell surrounding a gaseous core. These microbubbles act as nearly perfect intravascular reflectors of ultrasound energy and may be used to enhance the overall contrast and quality of ultrasound images. The purpose of this narrative review is to survey the current literature regarding CEUS imaging and discuss its diagnostic and therapeutic roles in current vascular and selected nonvascular applications. The PubMed, MEDLINE, and Embase databases were searched until July 2016 using the PubMed and Ovid Web-based search engines. The search terms used included contrast-enhanced, microbubble, ultrasound, carotid, aneurysm, and arterial. The diagnostic and therapeutic utility of CEUS imaging has grown exponentially, particularly in the realms of extracranial carotid arterial disease, aortic disease, and peripheral arterial disease. Studies have demonstrated that CEUS imaging is diagnostically superior to conventional ultrasound imaging in identifying vessel irregularities and measuring neovascularization to assess plaque vulnerability and end-muscle perfusion. Groups have begun to use microbubbles as agents in therapeutic applications for targeted drug and gene therapy delivery as well as for the enhancement of sonothrombolysis. The emerging technology of microbubbles and CEUS imaging holds considerable promise for cardiovascular medicine and cancer therapy given its diagnostic and therapeutic utility. Overall, with proper training and credentialing of technicians, the clinical implications are innumerable as microbubble technology is rapidly bursting onto the scene of cardiovascular medicine. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  6. Molecular imaging with dynamic contrast-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Miles, K.A., E-mail: k.a.miles@bsms.ac.u [Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton (United Kingdom)

    2010-07-15

    Dynamic contrast-enhanced computed tomography (DCE-CT) is a quantitative technique that employs rapid sequences of CT images after bolus administration of intravenous contrast material to measure a range of physiological processes related to the microvasculature of tissues. By combining knowledge of the molecular processes underlying changes in vascular physiology with an understanding of the relationship between vascular physiology and CT contrast enhancement, DCE-CT can be redefined as a molecular imaging technique. Some DCE-CT derived parameters reflect tissue hypoxia and can, therefore, provide information about the cellular microenvironment. DCE-CT can also depict physiological processes, such as vasodilatation, that represent the physiological consequences of molecular responses to tissue hypoxia. To date the main applications have been in stroke and oncology. Unlike some other molecular imaging approaches, DCE-CT benefits from wide availability and ease of application along with the use of contrast materials and software packages that have achieved full regulatory approval. Hence, DCE-CT represents a molecular imaging technique that is applicable in clinical practice today.

  7. Contrast enhancement of the cochlear aqueduct in MR imaging: its frequency and clinical significance

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, T.; Naganawa, S.; Fukatsu, H.; Sakurai, Y.; Ishigaki, T. [Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, 466-8550, Shouwa-ku, Nagoya (Japan); Aoki, I.; Ninomiya, A. [Medical Systems Company, Toshiba Corporation, Nasu Operations, Otawara-shi, Tochigi (Japan); Nakashima, T. [Department of Otorhinolaryngology, Nagoya University School of Medicine, Shouwa-ku, Nagoya (Japan)

    2003-09-01

    There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion. (orig.)

  8. Contrast enhanced ultrasound features of hepatic cystadenoma and hepatic cystadenocarcinoma.

    Science.gov (United States)

    Dong, Yi; Wang, Wen-Ping; Mao, Feng; Fan, Mei; Ignee, Andre; Serra, Carla; Sparchez, Zeno; Sporea, Ioan; Braden, Barbara; Dietrich, Christoph F

    2017-03-01

    Hepatic (biliary) cystic tumor (HBCT) is a rare focal cystic liver lesion, which has been rarely described in the literature. In our current multicenter, retrospective study, we aimed to analyze contrast enhanced ultrasound (CEUS) features and its diagnostic performance in histologically proved HBCT. Twenty-three patients with single HBCT were retrospectively analyzed. Histologically, 17 (73.9%) were benign hepatic (biliary) cystadenoma (HBCA), 6 (26.1%) were hepatic (biliary) cystadenocarcinoma (HBCAC). All CEUS examinations were assessed by two independent radiologists in consensus. Criteria of CEUS imaging evaluation included the contrast enhancement pattern of lesion (hypoenhancing, hyperenhancing, isoenhancing in comparison to the surrounding liver parenchyma) during the arterial, portal venous and late phases. After injection of ultrasound contrast agents, most of the HBCTs (78.3%, 18/23) had typical honeycomb enhancement pattern of the cystic wall, septa or mural nodules. Comparing between HBCA and HBCAC, hyperenhancement of the honeycomb septa during the arterial phase was more common in HBCA (p = .047). However, hypoenhancement during the portal venous and late phases was the characteristic of HBCAC (p = .041). The EFSUMB algorithm for CEUS for characterization of solid focal liver lesions is also applicable to HBCT. CEUS evaluation can avoid further diagnostic investigations or invasive biopsy procedure.

  9. Contrast-enhanced ultrasound features of histologically proven focal nodular hyperplasia: diagnostic performance compared with contrast-enhanced CT.

    Science.gov (United States)

    Wang, Wei; Chen, Li-Da; Lu, Ming-De; Liu, Guang-Jian; Shen, Shun-Li; Xu, Zuo-Feng; Xie, Xiao-Yan; Wang, Yan; Zhou, Lu-Yao

    2013-09-01

    To investigate and compare contrast-enhanced ultrasound (CEUS) in the characterisation of histologically proven focal nodular hyperplasia (FNH) with contrast-enhanced computed tomography (CECT). CEUS was performed in 85 patients with 85 histologically proven FNHs. Enhancement, centrifugal filling, spoke-wheel arteries, feeding artery and central scarring were reviewed and correlated with lesion size or liver background. Independent factors for predicting FNH from other focal liver lesions (FLLs) were evaluated. Forty-seven FLLs with CECT were randomly selected for comparison of diagnostic performance with CEUS. Centrifugal filling was more common (P = 0.002) and the significant predictor (P = 0.003) in FNHs ≤3 cm. Lesion size or liver background has no significant influence on the detection rate of the spoke-wheel arteries and feeding artery (P > 0.05). Central scarring was found in 42.6 % of FNHs ≥3 cm (P = 0.000). The area under the ROC curve, sensitivity and specificity showed no significant differences between CEUS and CECT (P > 0.05), except that the sensitivity of CEUS was better for reader 1 (P = 0.041). CEUS is valuable in characterising centrifugal filling signs or spoke wheels in small FNHs and should be employed as the first-line imaging technique for diagnosis of FNH. • The confident diagnosis of focal nodular hyperplasia is important in liver imaging. • The centrifugal filling sign is useful for diagnosis of FNHs ≤3 cm. • Contrast-enhanced ultrasound and contrast-enhanced CT have similar diagnostic performance for FNH. • CEUS should be the first-line imaging technique for the diagnosis of FNH.

  10. Polycystic ovary syndrome: dynamic contrast-enhanced ovary MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Erdem, C. Zuhal E-mail: sunarerdem@yahoo.com; Bayar, Ulku; Erdem, L. Oktay; Barut, Aykut; Gundogdu, Sadi; Kaya, Erdal

    2004-07-01

    Objective: to determine the enhancement behaviour of the ovaries in women with polycystic ovary syndrome (PCOS) by dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging and to compare these data with those of normal ovulating controls. Method: 24 women with PCOS and 12 controls underwent DCE-MR imaging. Dynamic images were acquired before and after injection of a contrast bolus at 30 s and the min of 1, 2, 3, 4 and 5. On postprocessing examination: (i) the ovarian volumes; (ii) the signal intensity value of each ovary per dynamic study; (iii) early-phase enhancement rate; (iv) time to peak enhancement (T{sub p}); and (v) percentage of washout of 5th min were determined. Data of the ovaries of the women with PCOS and controls were compared with Mann-Whitney U-test. Results: the mean values of T{sub p} were found to be significantly lower in women with PCOS than in controls (p<0.05). On the other hand, the mean values of ovarian volume, the early-phase enhancement rate, and percentage of washout of 5th min of ovaries were significantly higher in PCOS patients (p<0.05). Examination of the mean signal intensity-time curve revealed the ovaries in women with PCOS showed a faster and greater enhancement and wash-out. Conclusion: the enhancement behaviour of ovaries of women with PCOS may be significantly different from those of control subjects on DCE-MR imaging examination. In our experience, it is a valuable modality to highlight the vascularization changes in ovarian stroma with PCOS. We believe that improved DCE-MR imaging techniques may also provide us additional parameters in the diagnosis and treatment strategies of PCOS.

  11. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

    Science.gov (United States)

    Demi, Libertario; van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

    2015-11-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization.

  12. The role of contrast-enhanced endoscopic ultrasound in pancreatic adenocarcinoma

    DEFF Research Database (Denmark)

    Saftoiu, Adrian; Vilmann, Peter; Bhutani, Manoop S

    2016-01-01

    Contrast-enhanced endoscopic ultrasound (CE-EUS) allows characterization, differentiation, and staging of focal pancreatic masses. The method has a high sensitivity and specificity for the diagnosis of pancreatic adenocarcinoma which is visualized as hypo-enhanced as compared to the rest of the p......Contrast-enhanced endoscopic ultrasound (CE-EUS) allows characterization, differentiation, and staging of focal pancreatic masses. The method has a high sensitivity and specificity for the diagnosis of pancreatic adenocarcinoma which is visualized as hypo-enhanced as compared to the rest...... of the parenchyma while chronic pancreatitis and neuroendocrine tumors are generally either iso-enhanced or hyper-enhanced. The development of contrast-enhanced low mechanical index harmonic imaging techniques used in real time during endoscopic ultrasound (EUS) allowed perfusion imaging and the quantification...... contrast agents for early detection, tridimensional and fusion techniques for enhanced staging and resectability assessment but also novel applications of perfusion imaging for monitoring ablative therapy, improved local detection through EUS-guided sampling of portal vein flow or enhanced drug delivery...

  13. Contrast-enhanced cardiovascular magnetic resonance in primary and ischemic dilated cardiomyopathy.

    Science.gov (United States)

    Calore, Chiara; Cacciavillani, Luisa; Boffa, Giovanni Maria; Silva, Caterina; Tiso, Enrico; Marra, Martina Perazzolo; Bacchiega, Enrico; Corbetti, Francesco; Iliceto, Sabino

    2007-10-01

    Differentiation between primary dilated cardiomyopathy and ischemic cardiomyopathy has an important clinical significance. Contrast-enhanced cardiovascular magnetic resonance can play a role in this task, identifying myocardial scarring or fibrosis as presence of delayed enhancement. The aim of the present study was to evaluate the diagnostic potential of contrast-enhanced cardiovascular magnetic resonance in differentiating dilated cardiomyopathy from ischemic cardiomyopathy. Contrast-enhanced cardiovascular magnetic resonance was performed in 100 patients with left ventricular dilatation and reduced systolic function: 24 had normal coronary arteries (dilated cardiomyopathy group) and 76 had significant coronary artery disease (ischemic cardiomyopathy group), with or without previous myocardial infarction. In the dilated cardiomyopathy group, only seven (29%) patients showed delayed enhancement and its pattern was characterized by mid-wall, patchy or diffuse location. All patients with ischemic cardiomyopathy and prior myocardial infarction (54 subjects) showed delayed enhancement with subendocardial (n = 4) or transmural (n = 50) extension. Among the 22 patients with ischemic cardiomyopathy but without previous myocardial infarction, 13 (59%) showed either subendocardial (n = 4) or transmural (n = 9) delayed enhancement. Patterns of delayed enhancement are different in dilated cardiomyopathy and ischemic cardiomyopathy, reflecting the presence of scarring or various degrees of fibrosis in left ventricular myocardium. The presence of subendocardial or transmural delayed enhancement at contrast-enhanced cardiovascular magnetic resonance allowed distinction between dilated cardiomyopathy and ischemic cardiomyopathy with high sensitivity (88%) and specificity (100%). Integration of cardiovascular magnetic resonance results with angiographic information can be useful in the identification of pathogenic mechanisms underlying left ventricular dysfunction.

  14. Indeterminate breast lesions: Can contrast enhanced digital mammography change our decisions?

    OpenAIRE

    Samira Saraya; Lamia Adel; Asmaa Mahmoud

    2017-01-01

    Objective: To assess the efficiency of dual energy contrast enhanced mammography in the assessment of the indeterminate breast lesions (BIRADS 3 and BIRADS 4). Materials and methods: 34 female having 39 indeterminate breast lesions (BIRADS 3 and BIRADS 4) by digital mammography were further examined by dual energy contrast enhanced mammography. Two images were acquired at low and high energy in MLO view after 2 min and in CC view at 4 min post iodinated contrast injection (1.5 ml/kg with f...

  15. Contrast enhanced cartilage imaging: Comparison of ionic and non-ionic contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Wiener, Edzard [Department of Radiology, Technical University Munich, Ismaninger Str. 22, D-81675 Munich (Germany)]. E-mail: ewiener@roe.med.tu-muenchen.de; Woertler, Klaus [Department of Radiology, Technical University Munich, Ismaninger Str. 22, D-81675 Munich (Germany); Weirich, Gregor [Institute of Pathology, Technical University Munich, Troger Str. 18, D-81675 Munich (Germany); Rummeny, Ernst J. [Department of Radiology, Technical University Munich, Ismaninger Str. 22, D-81675 Munich (Germany); Settles, Marcus [Department of Radiology, Technical University Munich, Ismaninger Str. 22, D-81675 Munich (Germany)

    2007-07-15

    Our objective was to compare relaxation effects, dynamics and spatial distributions of ionic and non-ionic contrast agents in articular cartilage at concentrations typically used for direct MR arthrography at 1.5 T. Dynamic MR-studies over 11 h were performed in 15 bovine patella specimens. For each of the contrast agents gadopentetate dimeglumine, gadobenate dimeglumine, gadoteridol and mangafodipir trinatrium three patellae were placed in 2.5 mmol/L contrast solution. Simultaneous measurements of T {sub 1} and T {sub 2} were performed every 30 min using a high-spatial-resolution 'MIX'-sequence. T {sub 1}, T {sub 2} and {delta}R {sub 1}, {delta}R {sub 2} profile plots across cartilage thickness were calculated to demonstrate the spatial and temporal distributions. The charge is one of the main factors which controls the amount of the contrast media diffusing into intact cartilage, but independent of the charge, the spatial distribution across cartilage thickness remains highly inhomogeneous even after 11 h of diffusion. The absolute {delta}R {sub 2}-effect in cartilage is at least as large as the {delta}R {sub 1}-effect for all contrast agents. Maximum changes were 5-12 s{sup -1} for {delta}R {sub 1} and 8-15 s{sup -1} for {delta}R {sub 2}. This study indicates that for morphologically intact cartilage only the amount of contrast agents within cartilage is determined by the charge but not the spatial distribution across cartilage thickness. In addition, {delta}R {sub 2} can be considered for quantification of contrast agent concentrations, since it is of the same magnitude and less time consuming to measure than {delta}R {sub 1}.

  16. Contrast-enhanced ultrasonographic findings of hepatic paragonimiasis.

    Science.gov (United States)

    Lu, Qiang; Ling, Wen-Wu; Ma, Lin; Huang, Zi-Xing; Lu, Chang-Li; Luo, Yan

    2013-04-07

    To investigate the features of hepatic paragonimiasis on contrast-enhanced ultrasound (CEUS) imaging. Fifteen patients with hepatic paragonimiasis who were admitted to our hospital between March 2008 and August 2012 were enrolled to this study. The conventional ultrasound and CEUS examinations were performed with a Philips IU22 scanner with a 1-5-MHz convex transducer. After conventional ultrasound scanning was completed, the CEUS study was performed. Pulse inversion harmonic imaging was used for CEUS. A bolus injection of 2.4 mL of a sulfur hexafluoride-filled microbubble contrast agent (SonoVue) was administered. CEUS features were retrospectively reviewed and correlated with pathological findings. In total, 16 lesions were detected on CEUS. The mean size of the lesions was 4.4 ± 1.6 cm (range, 1.7-6.6 cm). Subcapsular location was found in 12 lesions (75%). All the lesions were hypoechoic. Six lesions (37.5%) were of mixed content, seven (43.8%) were solid with small cystic areas, and the other three (18.8%) were completely solid. Ten lesions (62.5%) were rim enhanced with irregular tract-like nonenhanced internal areas. Transient wedge-shaped hyperenhancement of the surrounding liver parenchyma was seen in seven lesions (43.8%). Areas with hyper- or iso-enhancement in the arterial phase showed contrast wash-out and appeared hypoenhanced in the late phase. The main pathological findings included: (1) coagulative or liquefactive necrosis within the lesion, infiltration of a large number of eosinophils with the formation of chronic eosinophilic abscesses and sporadic distribution of Charcot-Leyden crystals; and (2) hyperplasia of granulomatous and fibrous tissue around the lesion. Subcapsular location, hypoechogenicity, rim enhancement and tract-like nonenhanced areas could be seen as the main CEUS features of hepatic paragonimiasis.

  17. Contrast-enhanced ultrasonographic findings of hepatic paragonimiasis

    Science.gov (United States)

    Lu, Qiang; Ling, Wen-Wu; Ma, Lin; Huang, Zi-Xing; Lu, Chang-Li; Luo, Yan

    2013-01-01

    AIM: To investigate the features of hepatic paragonimiasis on contrast-enhanced ultrasound (CEUS) imaging. METHODS: Fifteen patients with hepatic paragonimiasis who were admitted to our hospital between March 2008 and August 2012 were enrolled to this study. The conventional ultrasound and CEUS examinations were performed with a Philips IU22 scanner with a 1-5-MHz convex transducer. After conventional ultrasound scanning was completed, the CEUS study was performed. Pulse inversion harmonic imaging was used for CEUS. A bolus injection of 2.4 mL of a sulfur hexafluoride-filled microbubble contrast agent (SonoVue) was administered. CEUS features were retrospectively reviewed and correlated with pathological findings. RESULTS: In total, 16 lesions were detected on CEUS. The mean size of the lesions was 4.4 ± 1.6 cm (range, 1.7-6.6 cm). Subcapsular location was found in 12 lesions (75%). All the lesions were hypoechoic. Six lesions (37.5%) were of mixed content, seven (43.8%) were solid with small cystic areas, and the other three (18.8%) were completely solid. Ten lesions (62.5%) were rim enhanced with irregular tract-like nonenhanced internal areas. Transient wedge-shaped hyperenhancement of the surrounding liver parenchyma was seen in seven lesions (43.8%). Areas with hyper- or iso-enhancement in the arterial phase showed contrast wash-out and appeared hypoenhanced in the late phase. The main pathological findings included: (1) coagulative or liquefactive necrosis within the lesion, infiltration of a large number of eosinophils with the formation of chronic eosinophilic abscesses and sporadic distribution of Charcot-Leyden crystals; and (2) hyperplasia of granulomatous and fibrous tissue around the lesion. CONCLUSION: Subcapsular location, hypoechogenicity, rim enhancement and tract-like nonenhanced areas could be seen as the main CEUS features of hepatic paragonimiasis. PMID:23599629

  18. Subendometrial enhancement and peritumoral enhancement for assessing endometrial cancer on dynamic contrast enhanced MR imaging.

    Science.gov (United States)

    Fujii, Shinya; Kido, Aki; Baba, Tsukasa; Fujimoto, Koji; Daido, Sayaka; Matsumura, Noriomi; Konishi, Ikuo; Togashi, Kaori

    2015-04-01

    To evaluate the diagnostic accuracy of subendometrial enhancement (SEE) in assessing the myometrial invasion in endometrial cancer, the frequency and clinical significance of peritumoral enhancement (PTE) on dynamic contrast enhanced (DCE) imaging. MR images of 147 patients with endometrial cancer were retrospectively analyzed for intact SEE and PTEs: Type 1, a focal early enhancement peritumorally, and Type 2, an irregular thin-layered early intense enhancement peritumorally. Two radiologists independently assessed intact SEE and PTEs on DCE imaging and compared the lesions by the presence and depth of myometrial invasion, grade, lymphovascular space involvement (LVSI), and lymph node metastasis. The relationship between SEE, PTEs, and each factor was analyzed using univariate and multivariate analyses. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for SEE. The sensitivity, specificity, PPV, NPV and diagnostic accuracy for myometrial invasion based on SEE disruption on DCE were 96.6%, 32.1-46.4%, 85.8-88.5%, 69.2-76.5%, and 84.4-87.1%. According to multivariate analysis, SEE significantly predicted myometrial invasion (p<0.0001). PTE Type 2 significantly predicted myometrial invasion presence (p<0.05) and depth (p<0.01). Diagnosis of myometrial invasion only by using SEE might be difficult on DCE-MRI due to the overestimation by strong focal enhancement of PTE Type 1. PTE Type 2 correlates both with the presence and depth of myometrial invasion and also may play an important role in the diagnosis of LVSI. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Applications of contrast-enhanced ultrasound in the kidney.

    Science.gov (United States)

    Kazmierski, Brittany; Deurdulian, Corinne; Tchelepi, Hisham; Grant, Edward G

    2017-08-30

    Incidental discovery of renal lesions on cross-sectional imaging studies performed for other indications is not uncommon. With the increased reliance on medical imaging, the number of incidentally detected renal lesions has also grown over time. While simple cysts account for the majority of these lesions, the presence of complex features within a cystic lesion, such as septations and solid components, can present a confusing picture. Solid lesions, too, can be indeterminate, and distinguishing between benign solid masses (like lipid-poor angiomyolipomas and oncocytomas) and renal cell carcinoma affects patient management and can prevent unnecessary interventions. Indeterminate renal lesions are traditionally further characterized by multiphase imaging, such as contrast-enhanced computed tomography and magnetic resonance imaging. Contrast-enhanced ultrasound (CEUS) is a new, relatively inexpensive technique that has become increasingly employed in the diagnostic workup of indeterminate renal lesions. With its lack of nephrotoxicity, the absence of ionizing radiation, and the ability to evaluate the enhancement pattern of renal lesions quickly and in real-time, CEUS has unique advantages over traditional imaging modalities. This article provides an overview of the current clinical applications of CEUS in characterizing renal lesions, both cystic and solid. Additional applications of CEUS in the kidney, including its roles in renal transplant evaluation and guidance for percutaneous biopsy, will also be briefly discussed.

  20. Automatic image equalization and contrast enhancement using Gaussian mixture modeling.

    Science.gov (United States)

    Celik, Turgay; Tjahjadi, Tardi

    2012-01-01

    In this paper, we propose an adaptive image equalization algorithm that automatically enhances the contrast in an input image. The algorithm uses the Gaussian mixture model to model the image gray-level distribution, and the intersection points of the Gaussian components in the model are used to partition the dynamic range of the image into input gray-level intervals. The contrast equalized image is generated by transforming the pixels' gray levels in each input interval to the appropriate output gray-level interval according to the dominant Gaussian component and the cumulative distribution function of the input interval. To take account of the hypothesis that homogeneous regions in the image represent homogeneous silences (or set of Gaussian components) in the image histogram, the Gaussian components with small variances are weighted with smaller values than the Gaussian components with larger variances, and the gray-level distribution is also used to weight the components in the mapping of the input interval to the output interval. Experimental results show that the proposed algorithm produces better or comparable enhanced images than several state-of-the-art algorithms. Unlike the other algorithms, the proposed algorithm is free of parameter setting for a given dynamic range of the enhanced image and can be applied to a wide range of image types.

  1. Contrast-Enhanced Ultrasound in Vascular Surgery: Review and Update

    DEFF Research Database (Denmark)

    Bredahl, Kim; Mestre, Xavier Marti; Coll, Ramon Vila

    2017-01-01

    are easy to use, manageable, and safe. This topical review attempts to summarize and highlight the current evidence and future prospects for contrast-enhanced ultrasound in vascular surgery, with a particular focus on opportunities in carotid and lower limb arteriosclerotic disease and surveillance after......Accurate imaging methods associated with minimum patient risk are important tools for clinical decision-making in vascular surgery. Today, traditional imaging methods, such as computed tomography angiography, magnetic resonance angiography, and digital subtraction angiography are the preferred...... modalities. Ultrasound has only challenged these methods in assessment of carotid disease, aortic aneurysms, venous insufficiency, and thromboembolism and in surveillance of in situ bypasses. These practice patterns may change with the introduction of second-generation ultrasound contrast agents which...

  2. Value of contrast-enhanced ultrasound in rheumatoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Zordo, Tobias de; Mlekusch, Sabine P.; Feuchtner, Gudrun M. [Department of Radiology II, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck (Austria); Mur, Erich [Department of Internal Medicine, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck (Austria); Schirmer, Michael [Department of Internal Medicine, Hospital of the Elisabethines Klagenfurt, Voelkermarkter Strasse 15-19, 9020 Klagenfurt (Austria); Klauser, Andrea S. [Department of Radiology II, Medical University Innsbruck, Anichstrasse 35, 6020 Innsbruck (Austria)], E-mail: andrea.klauser@i-med.ac.at

    2007-11-15

    The purpose of this review is to describe the spectrum of sonographic findings in rheumatic diseases with respect to the diagnostic potential using US contrast media which prove activity or inactivity in synovial tissue where new treatment regimes target. Synovial activity can be found in non-erosive and erosive forms of primary and secondary osteoarthritis, and in inflammatory forms of joint diseases like rheumatoid arthritis and peripheral manifestations of spondyloarthritis including, ankylosing spondylitis, Reiter's syndrome, psoriatic arthritis and enteropathic arthritis. It can also be present in metabolic and endocrine forms of arthritis, in connective tissue arthropathies like systemic lupus erythematosus or scleroderma and in infectious arthritis. Ultrasound should be used as first-line imaging modality in suspected early cases of RA and other forms of arthritis, whereas contrast-enhanced ultrasound (CEUS) can further enable for sensitive assessment of vascularity which correlates with disease activity.

  3. Subendometrial enhancement and peritumoral enhancement for assessing endometrial cancer on dynamic contrast enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Shinya [Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, Yonago (Japan); Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Kido, Aki, E-mail: akikido@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Baba, Tsukasa [Departments of Gynecology and Obstetrics, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Fujimoto, Koji; Daido, Sayaka [Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Matsumura, Noriomi; Konishi, Ikuo [Departments of Gynecology and Obstetrics, Graduate School of Medicine, Kyoto University, Kyoto (Japan); Togashi, Kaori [Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto (Japan)

    2015-04-15

    Highlights: •We have assessed the peritumoral enhancement (PTE), which mimics SEE on DCE. •We evaluated the diagnostic accuracy of SEE for the myometrial invasion and the frequency of PTE. •We assessed the relationship between these enhancements and important pathologic factors. •PTE Type 1 is the main factor causing the overestimation of myometrial invasion using SEE on DCE. •PTE Type 2 correlates the myometrial invasion and may play an important role in the diagnosis of LVSI. -- Abstract: Objectives: To evaluate the diagnostic accuracy of subendometrial enhancement (SEE) in assessing the myometrial invasion in endometrial cancer, the frequency and clinical significance of peritumoral enhancement (PTE) on dynamic contrast enhanced (DCE) imaging. Materials and methods: MR images of 147 patients with endometrial cancer were retrospectively analyzed for intact SEE and PTEs: Type 1, a focal early enhancement peritumorally, and Type 2, an irregular thin-layered early intense enhancement peritumorally. Two radiologists independently assessed intact SEE and PTEs on DCE imaging and compared the lesions by the presence and depth of myometrial invasion, grade, lymphovascular space involvement (LVSI), and lymph node metastasis. The relationship between SEE, PTEs, and each factor was analyzed using univariate and multivariate analyses. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for SEE. Results: The sensitivity, specificity, PPV, NPV and diagnostic accuracy for myometrial invasion based on SEE disruption on DCE were 96.6%, 32.1–46.4%, 85.8–88.5%, 69.2–76.5%, and 84.4–87.1%. According to multivariate analysis, SEE significantly predicted myometrial invasion (p < 0.0001). PTE Type 2 significantly predicted myometrial invasion presence (p < 0.05) and depth (p < 0.01). Conclusion: Diagnosis of myometrial invasion only by using SEE might be difficult on DCE-MRI due to the

  4. Assessment of mass detection performance in contrast enhanced digital mammography

    Science.gov (United States)

    Carton, Ann-Katherine; de Carvalho, Pablo M.; Li, Zhijin; Dromain, Clarisse; Muller, Serge

    2015-03-01

    We address the detectability of contrast-agent enhancing masses for contrast-agent enhanced spectral mammography (CESM), a dual-energy technique providing functional projection images of breast tissue perfusion and vascularity using simulated CESM images. First, the realism of simulated CESM images from anthropomorphic breast software phantoms generated with a software X-ray imaging platform was validated. Breast texture was characterized by power-law coefficients calculated in data sets of real clinical and simulated images. We also performed a 2-alternative forced choice (2-AFC) psychophysical experiment whereby simulated and real images were presented side-by-side to an experienced radiologist to test if real images could be distinguished from the simulated images. It was found that texture in our simulated CESM images has a fairly realistic appearance. Next, the relative performance of human readers and previously developed mathematical observers was assessed for the detection of iodine-enhancing mass lesions containing different contrast agent concentrations. A four alternative-forced-choice (4 AFC) task was designed; the task for the model and human observer was to detect which one of the four simulated DE recombined images contained an iodineenhancing mass. Our results showed that the NPW and NPWE models largely outperform human performance. After introduction of an internal noise component, both observers approached human performance. The CHO observer performs slightly worse than the average human observer. There is still work to be done in improving model observers as predictors of human-observer performance. Larger trials could also improve our test statistics. We hope that in the future, this framework of software breast phantoms, virtual image acquisition and processing, and mathematical observers can be beneficial to optimize CESM imaging techniques.

  5. Gd-HOPO Based High Relaxivity MRI Contrast Agents

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Ankona; Raymond, Kenneth

    2008-11-06

    Tris-bidentate HOPO-based ligands developed in our laboratory were designed to complement the coordination preferences of Gd{sup 3+}, especially its oxophilicity. The HOPO ligands provide a hexadentate coordination environment for Gd{sup 3+} in which all he donor atoms are oxygen. Because Gd{sup 3+} favors eight or nine coordination, this design provides two to three open sites for inner-sphere water molecules. These water molecules rapidly exchange with bulk solution, hence affecting the relaxation rates of bulk water olecules. The parameters affecting the efficiency of these contrast agents have been tuned to improve contrast while still maintaining a high thermodynamic stability for Gd{sup 3+} binding. The Gd- HOPO-based contrast agents surpass current commercially available agents ecause of a higher number of inner-sphere water molecules, rapid exchange of inner-sphere water molecules via an associative mechanism, and a long electronic relaxation time. The contrast enhancement provided by these agents is at least twice that of commercial contrast gents, which are based on polyaminocarboxylate ligands.

  6. Contrast-enhanced Spectral Mammography: Technique, Indications, and Clinical Applications.

    Science.gov (United States)

    Bhimani, Chandni; Matta, Danielle; Roth, Robyn G; Liao, Lydia; Tinney, Elizabeth; Brill, Kristin; Germaine, Pauline

    2017-01-01

    Contrast-enhanced spectral mammography (CESM) combines the benefits of full field digital mammography with the concept of tumor angiogenesis. Technique and practical applications of CESM are discussed. An overview of the technique is followed by a demonstration of practical applications of CESM in our practice. We have successfully implemented CESM into our practice as a screening, diagnostic, staging, and treatment response tool. It is important to understand the technique of CESM and how to incorporate it into practice. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  7. Dynamic Contrast-Enhanced CT in Patients with Pancreatic Cancer

    DEFF Research Database (Denmark)

    Eriksen, Rie Ø; Strauch, Louise S; Sandgaard, Michael

    2016-01-01

    The aim of this systematic review is to provide an overview of the use of Dynamic Contrast-enhanced Computed Tomography (DCE-CT) in patients with pancreatic cancer. This study was composed according to the PRISMA guidelines 2009. The literature search was conducted in PubMed, Cochrane Library...... tissue, compared with measurements in pancreatic tissue outside of tumor, or normal pancreatic tissue in control groups of healthy volunteers. The studies were heterogeneous in the number of patients enrolled and scan protocols. Perfusion parameters measured and analyzed by DCE-CT might be useful...

  8. Contrast enhancing solution for use in confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tannous, Zeina; Torres, Abel; Gonzalez, Salvador

    2006-10-31

    A method of optically detecting a tumor during surgery. The method includes imaging at least one test point defined on the tumor using a first optical imaging system to provide a first tumor image. The method further includes excising a first predetermined layer of the tumor for forming an in-vivo defect area. A predetermined contrast enhancing solution is disposed on the in-vivo defect area, which is adapted to interact with at least one cell anomaly, such as basal cell carcinoma, located on the in-vivo defect area for optically enhancing the cell anomaly. Thereafter the defect area can be optically imaged to provide a clear and bright representation of the cell anomaly to aid a surgeon while surgically removing the cell anomaly.

  9. Contrast-enhanced Digital Mammography: A Single-Institution Experience of the First 208 Cases.

    Science.gov (United States)

    Lewis, Tiffany C; Pizzitola, Victor J; Giurescu, Marina E; Eversman, William G; Lorans, Roxanne; Robinson, Kristin A; Patel, Bhavika K

    2017-01-01

    Contrast-enhanced digital mammography (CEDM) is the only imaging modality that provides both (a) a high-resolution, low-energy image comparable to that of digital mammography and (b) a contrast-enhanced image similar to that of magnetic resonance imaging. We report the initial 208 CEDM examinations performed for various clinical indications and provide illustrative case examples. Given its success in recent studies and our experience of CEDM primarily as a diagnostic adjunct, CEDM can potentially improve breast cancer detection by combining the low-cost conclusions of screening mammography with the high sensitivity of magnetic resonance imaging. © 2016 Wiley Periodicals, Inc.

  10. Optimum wavelet based masking for the contrast enhancement of medical images using enhanced cuckoo search algorithm.

    Science.gov (United States)

    Daniel, Ebenezer; Anitha, J

    2016-04-01

    Unsharp masking techniques are a prominent approach in contrast enhancement. Generalized masking formulation has static scale value selection, which limits the gain of contrast. In this paper, we propose an Optimum Wavelet Based Masking (OWBM) using Enhanced Cuckoo Search Algorithm (ECSA) for the contrast improvement of medical images. The ECSA can automatically adjust the ratio of nest rebuilding, using genetic operators such as adaptive crossover and mutation. First, the proposed contrast enhancement approach is validated quantitatively using Brain Web and MIAS database images. Later, the conventional nest rebuilding of cuckoo search optimization is modified using Adaptive Rebuilding of Worst Nests (ARWN). Experimental results are analyzed using various performance matrices, and our OWBM shows improved results as compared with other reported literature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Contrast-enhanced ultrasound features of histologically proven focal nodular hyperplasia: diagnostic performance compared with contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Chen, Li-Da; Liu, Guang-Jian; Xu, Zuo-Feng; Xie, Xiao-Yan; Wang, Yan; Zhou, Lu-Yao [The First Affiliated Hospital of Sun Yat-Sen University Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Department of Medical Ultrasonics, Guangzhou (China); Lu, Ming-De [The First Affiliated Hospital of Sun Yat-Sen University Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Department of Medical Ultrasonics, Guangzhou (China); The First Affiliated Hospital of Sun Yat-Sen University, Department of Hepatobiliary Surgery, Guangzhou (China); Shen, Shun-Li [The First Affiliated Hospital of Sun Yat-Sen University, Department of Hepatobiliary Surgery, Guangzhou (China)

    2013-09-15

    To investigate and compare contrast-enhanced ultrasound (CEUS) in the characterisation of histologically proven focal nodular hyperplasia (FNH) with contrast-enhanced computed tomography (CECT). CEUS was performed in 85 patients with 85 histologically proven FNHs. Enhancement, centrifugal filling, spoke-wheel arteries, feeding artery and central scarring were reviewed and correlated with lesion size or liver background. Independent factors for predicting FNH from other focal liver lesions (FLLs) were evaluated. Forty-seven FLLs with CECT were randomly selected for comparison of diagnostic performance with CEUS. Centrifugal filling was more common (P = 0.002) and the significant predictor (P = 0.003) in FNHs {<=}3 cm. Lesion size or liver background has no significant influence on the detection rate of the spoke-wheel arteries and feeding artery (P > 0.05). Central scarring was found in 42.6 % of FNHs {>=}3 cm (P = 0.000). The area under the ROC curve, sensitivity and specificity showed no significant differences between CEUS and CECT (P > 0.05), except that the sensitivity of CEUS was better for reader 1 (P = 0.041). CEUS is valuable in characterising centrifugal filling signs or spoke wheels in small FNHs and should be employed as the first-line imaging technique for diagnosis of FNH. (orig.)

  12. Contrast-Enhanced Ultrasound Imaging Based on Bubble Region Detection

    Directory of Open Access Journals (Sweden)

    Yurong Huang

    2017-10-01

    Full Text Available The study of ultrasound contrast agent imaging (USCAI based on plane waves has recently attracted increasing attention. A series of USCAI techniques have been developed to improve the imaging quality. Most of the existing methods enhance the contrast-to-tissue ratio (CTR using the time-frequency spectrum differences between the tissue and ultrasound contrast agent (UCA region. In this paper, a new USCAI method based on bubble region detection was proposed, in which the frequency difference as well as the dissimilarity of tissue and UCA in the spatial domain was taken into account. A bubble wavelet based on the Doinikov model was firstly constructed. Bubble wavelet transformation (BWT was then applied to strengthen the UCA region and weaken the tissue region. The bubble region was thereafter detected by using the combination of eigenvalue and eigenspace-based coherence factor (ESBCF. The phantom and rabbit in vivo experiment results suggested that our method was capable of suppressing the background interference and strengthening the information of UCA. For the phantom experiment, the imaging CTR was improved by 10.1 dB compared with plane wave imaging based on delay-and-sum (DAS and by 4.2 dB over imaging based on BWT on average. Furthermore, for the rabbit kidney experiment, the corresponding improvements were 18.0 dB and 3.4 dB, respectively.

  13. Optimal exposure techniques for iodinated contrast enhanced breast CT

    Science.gov (United States)

    Glick, Stephen J.; Makeev, Andrey

    2016-03-01

    Screening for breast cancer using mammography has been very successful in the effort to reduce breast cancer mortality, and its use has largely resulted in the 30% reduction in breast cancer mortality observed since 1990 [1]. However, diagnostic mammography remains an area of breast imaging that is in great need for improvement. One imaging modality proposed for improving the accuracy of diagnostic workup is iodinated contrast-enhanced breast CT [2]. In this study, a mathematical framework is used to evaluate optimal exposure techniques for contrast-enhanced breast CT. The ideal observer signal-to-noise ratio (i.e., d') figure-of-merit is used to provide a task performance based assessment of optimal acquisition parameters under the assumptions of a linear, shift-invariant imaging system. A parallel-cascade model was used to estimate signal and noise propagation through the detector, and a realistic lesion model with iodine uptake was embedded into a structured breast background. Ideal observer performance was investigated across kVp settings, filter materials, and filter thickness. Results indicated many kVp spectra/filter combinations can improve performance over currently used x-ray spectra.

  14. [Efficacy of gadobenate dimeglumine vs gadopentetate dimeglumine in contrast- enhanced magnetic resonance imaging for diagnosis of solitary brain metastases].

    Science.gov (United States)

    Wang, Qing-jun; Wang, Yong; Xu, Xian; Xiao, Hui; Ma, Lin

    2011-12-01

    To compare gadobenate dimeglumine (Gd-BOPTA) and gadopentetate dimeglumine (Gd-DTPA) for their efficacy as contrast agents in contrast-enhanced magnetic resonance imaging (MRI) for diagnosis of solitary brain metastases (SBM). We conducted an intra-individual study of contrast-enhanced T1-weighted MRI (T(1)WI) data from 27 Chinese patients with suspected SBM to compare the enhancement findings of two different MRI contrast agents, Gd-BOPTA and Gd-DTPA (at equivalent doses of 0.1 mmol/kg), for the detection of SBM. All the patients underwent two identical MRI examinations on a 3.0-T MRI scanner first with Gd-DTPA and then with Gd-BOPTA. Evaluation of the contrast enhancement was performed qualitatively (border delineation, extent, internal morphology, and contrast enhancement) and quantitatively (lesion-to-brain ratio, contrast-to-noise ratio, and percent enhancement) by 3 independent, fully blinded, and highly experienced neuroradiologists. Qualitative assessment by readers revealed a significant overall preference (P<0.05) for Gd-BOPTA over Gd-DOTA in terms of lesion border delineation, extent, lesion internal morphology, and contrast enhancement. Quantitative assessment also revealed a significant better performance of Gd-BOPTA in light of lesion-to-brain ratio (P<0.05), contrast-to-noise ratio (P<0.05), and percent enhancement (P<0.05). At an equivalent dose, Gd-BOPTA allows better contrast enhancement of SBM than Gd-DTPA in MRI.

  15. Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Hosoya, T.; Adachi, M.; Sugai, Y. [Dept. of Radiology, Yamagata University School of Medicine (Japan); Yamaguchi, K.; Yamaguchi, K. [Dept. of Ophthalmology, Yamagata University School of Medicine (Japan); Kato, T. [3. Dept. of Internal Medicine, Yamagata University School of Medicine (Japan)

    2001-04-01

    We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

  16. Contrast-enhanced ultrasonography to diagnose complicated acute cholecystitis.

    Science.gov (United States)

    Sagrini, Elisabetta; Pecorelli, Anna; Pettinari, Irene; Cucchetti, Alessandro; Stefanini, Federico; Bolondi, Luigi; Piscaglia, Fabio

    2016-02-01

    Gangrenous cholecystitis and perforation are severe complications of acute cholecystitis, which have a challenging preoperative diagnosis. Early identification allows better surgical management. Contrast-enhanced computed tomography (ceCT) is the current diagnostic gold standard. Contrast-enhanced ultrasonography (CEUS) is a promising tool for the diagnosis of gallbladder perforation, but data from the literature concerning efficacy are sparse. The aim of the study was to evaluate CEUS findings in pathologically proven complicated cholecystitis (gangrenous, perforated gallbladder, pericholecystic abscess). A total of 8 patients submitted to preoperative CEUS, and with subsequent proven acute complicated cholecystitis at surgical inspection and pathological analysis, were retrospectively identified. The final diagnosis was gangrenous/phlegmonous cholecystitis (n. 2), phlegmonous/ulcerative changes plus pericholecystic abscess (n. 2), perforated plus pericholecystic abscess (n. 3), or perforated plus pericholecystic biliary collection (n. 1). Conventional US findings revealed irregularly thickened gallbladder walls in all 8 patients, with vaguely defined walls in 7 patients, four of whom also had striated wall thickening. CEUS revealed irregular enhancing gallbladder walls in all patients. A distinct wall defect was seen in six patients, confirmed as gangrenous/phlegmonous cholecystitis at pathology in all six, and in four as perforation at macroscopic surgical inspection. CEUS is a non-invasive easily repeatable technique that can be performed at the bedside, and is able to accurately diagnose complicated/perforated cholecystitis. Despite the limited sample size in the present case series, CEUS appears as a promising tool for the management of patients with the clinical possibility of having an acute complicated cholecystitis.

  17. Diagnostic Value of Contrast-Enhanced Ultrasound Evaluation of Malignant and Benign Solitary Thyroid Nodules

    Directory of Open Access Journals (Sweden)

    Priedītis Pēteris

    2016-02-01

    Full Text Available The aim of the study was to investigate the diagnostic value of contrast-enhanced ultrasound (CEUS in differentiating benign and malignant thyroid nodules. Thirty-five patients with morphologically proved thyroid nodules (17 malignant; 18 benign, underwent CEUS examination. Five enhancement patterns were evaluated: vascularisation, homogeneity, presence of peripheral rim type enhancement, wash-out rate of the contrast medium, and enhancement using microvascular imaging application. Time-intensity curves (TIC were analysed in post-processing and defined as three types: slow versus rapid and stable versus rapid biphasic wash-out. Diagnostic value of the listed CEUS parameters was calculated. The results showed medium strength correlation between morphology (benign versus malignant nodule and type of TIC curve rs = 0.38 (p = 0.021, as well as between mode of contrast enhancement rs = 0.39 (p = 0.022 and wash-out pattern rs =0.39 (p = 0.024. The overall pooled sensitivity of selected diagnostic parameters was 82%, specificity 57%, and accuracy 70%. Malignant nodules were characterised by iso- or hypovascular contrast enhancement and slow wash-out, while benign nodules showed hypervascular enhancement with rapid wash-out TIC curve and rim-like pattern. The CEUS patterns significantly differed between malignant and benign thyroid nodules with high diagnostic accuracy. Thus, CEUS has important clinical value as an additional tool to ultrasound and fine needle biopsy.

  18. Electron acceleration via high contrast laser interacting with submicron clusters

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lu; Chen Liming; Wang Weiming; Yan Wenchao; Yuan Dawei; Mao Jingyi; Wang Zhaohua; Liu Cheng; Shen Zhongwei; Li Yutong; Dong Quanli; Lu Xin; Ma Jinglong; Wei Zhiyi [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Faenov, Anatoly; Pikuz, Tatiana [Joint Institute for High Temperature of the Russian Academy of Sciences, Izhorskaya 13/19, Moscow 127412 (Russian Federation); Quantum Beams Science Directorate, JAEA, Kizugawa, Kyoto (Japan); Li Dazhang [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Institute of High Energy Physics, CAS, Beijing 100049 (China); Sheng Zhengming [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang Jie [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2012-01-02

    We experimentally investigated electron acceleration from submicron size argon clusters-gas target irradiated by a 100 fs, 10 TW laser pulses having a high-contrast. Electron beams are observed in the longitudinal and transverse directions to the laser propagation. The measured energy of the longitudinal electron reaches 600 MeV and the charge of the electron beam in the transverse direction is more than 3 nC. A two-dimensional particle-in-cell simulation of the interaction has been performed and it shows an enhancement of electron charge by using the cluster-gas target.

  19. High-contrast and fast electrochromic switching enabled by plasmonics

    Science.gov (United States)

    Talin, Albert; Xu, Ting; Walter, Erich; Agrawal, Amit; Bohn, Christopher; Velmurugan, Jeyavel; Zhu, Wenqi; Lezec, Henri

    With vibrant colors and simple, room-temperature processing methods, electrochromic polymers have long attracted attention as active materials for flexible, low-power consuming devices such as smart windows and displays. However, despite their many advantages, slow switching speed and complexity of combining several separate polymers to achieve full-color gamut has limited electrochromic materials to niche applications. Here we exploit the enhanced light-matter interaction associated with the deep-subwavelength mode confinement of surface plasmon polaritons propagating in metallic nanoslit arrays coated with ultra-thin electrochromic polymers to build a novel configuration for achieving high-contrast and fast electrochromic switching. The switchable configuration retains the short temporal charge-diffusion characteristics of thin electrochromic films while maintaining the high optical-contrast associated with thicker electrochromic coatings. We further demonstrate that by controlling the pitch of the nanoslit arrays, it is possible to achieve a full-color response with high-contrast and fast switching-speeds while relying on just one electrochromic polymer.

  20. Irregular vascular pattern by contrast-enhanced ultrasonography and high serum Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein level predict poor outcome after successful radiofrequency ablation in patients with early-stage hepatocellular carcinoma.

    Science.gov (United States)

    Takada, Hitomi; Tsuchiya, Kaoru; Yasui, Yutaka; Nakakuki, Natsuko; Tamaki, Nobuharu; Suzuki, Shoko; Nakanishi, Hiroyuki; Itakura, Jun; Takahashi, Yuka; Kurosaki, Masayuki; Asahina, Yasuhiro; Enomoto, Nobuyuki; Izumi, Namiki

    2016-11-01

    Radiofrequency ablation (RFA) is considered the most effective treatment for early-stage hepatocellular carcinoma (HCC) patients unsuitable for resection. However, poor outcome after RFA has occasionally been reported worldwide. To predict such an outcome, we investigated imaging findings using contrast-enhanced ultrasonography (CEUS) with Sonazoid and serum tumor markers before RFA. This study included 176 early-stage HCC patients who had initially achieved successful RFA. Patients were examined using CEUS; their levels of alpha-fetoprotein (AFP), Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3), and des-gamma-carboxy prothrombin before RFA were measured. Sonazoid provided parenchyma-specific contrast imaging and facilitated tumor vascular architecture imaging through maximum intensity projection (MIP). Kaplan-Meier analysis examined cumulative rates of local tumor progression, intrasubsegmental recurrence, and survival; factors associated with these were determined with Cox proportional hazards analysis. Local tumor progression (n = 15), intrasubsegmental recurrence (n = 46), and death (n = 18) were observed. Irregular pattern in MIP classification and serum AFP-L3 level (>10%) before RFA were identified as independent risk factors for local tumor progression and intrasubsegmental recurrence. These two factors were independently associated with poor survival after RFA (irregular pattern in MIP: hazard ratio, (HR) = 8.26; 95% confidence interval, (CI) = 2.24-30.3; P = 0.002 and AFP-L3 > 10%: HR = 2.94; 95% CI = 1.09-7.94; P = 0.033). Irregular MIP pattern by CEUS and high level of serum AFP-L3 were independent risk factors for poor outcome after successful RFA. The Patients with these findings should be considered as special high-risk group in early-stage HCC. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  1. Morphological image processing for quantitative shape analysis of biomedical structures: effective contrast enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Kimori, Yoshitaka, E-mail: kimori@orion.ac.jp [National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787 (Japan)

    2013-11-01

    A contrast enhancement approach utilizing a new type of mathematical morphology called rotational morphological processing is introduced. The method is quantitatively evaluated and then applied to some medical images. Image processing methods significantly contribute to visualization of images captured by biomedical modalities (such as mammography, X-ray computed tomography, magnetic resonance imaging, and light and electron microscopy). Quantitative interpretation of the deluge of complicated biomedical images, however, poses many research challenges, one of which is to enhance structural features that are scarcely perceptible to the human eye. This study introduces a contrast enhancement approach based on a new type of mathematical morphology called rotational morphological processing. The proposed method is applied to medical images for the enhancement of structural features. The effectiveness of the method is evaluated quantitatively by the contrast improvement ratio (CIR). The CIR of the proposed method is 12.1, versus 4.7 and 0.1 for two conventional contrast enhancement methods, clearly indicating the high contrasting capability of the method.

  2. Digital contrast enhancement of (18)Fluorine-fluorodeoxyglucose positron emission tomography images in hepatocellular carcinoma.

    Science.gov (United States)

    Pandey, Anil Kumar; Sharma, Sanjay Kumar; Agarwal, Krishan Kant; Sharma, Punit; Bal, Chandrasekhar; Kumar, Rakesh

    2016-01-01

    The role of (18)fluorodeoxyglucose positron emission tomography (PET) is limited for detection of primary hepatocellular carcinoma (HCC) due to low contrast to the tumor, and normal hepatocytes (background). The aim of the present study was to improve the contrast between the tumor and background by standardizing the input parameters of a digital contrast enhancement technique. A transverse slice of PET image was adjusted for the best possible contrast, and saved in JPEG 2000 format. We processed this image with a contrast enhancement technique using 847 possible combinations of input parameters (threshold "m" and slope "e"). The input parameters which resulted in an image having a high value of 2(nd) order entropy, and edge content, and low value of absolute mean brightness error, and saturation evaluation metrics, were considered as standardized input parameters. The same process was repeated for total nine PET-computed tomography studies, thus analyzing 7623 images. The selected digital contrast enhancement technique increased the contrast between the HCC tumor and background. In seven out of nine images, the standardized input parameters "m" had values between 150 and 160, and for other two images values were 138 and 175, respectively. The value of slope "e" was 4 in 4 images, 3 in 3 images and 1 in 2 images. It was found that it is important to optimize the input parameters for the best possible contrast for each image; a particular value was not sufficient for all the HCC images. The use of above digital contrast enhancement technique improves the tumor to background ratio in PET images of HCC and appears to be useful. Further clinical validation of this finding is warranted.

  3. Endogenous contrast MRI of cardiac fibrosis: beyond late gadolinium enhancement.

    Science.gov (United States)

    van Oorschot, Joep W M; Gho, Johannes M I H; van Hout, Gerardus P J; Froeling, Martijn; Jansen Of Lorkeers, Sanne J; Hoefer, Imo E; Doevendans, Pieter A; Luijten, Peter R; Chamuleau, Steven A J; Zwanenburg, Jaco J M

    2015-05-01

    The aim of this review is to provide an overview of detection of cardiac fibrosis with MRI using current standards and novel endogenous MRI techniques. Assessment of cardiac fibrosis is important for diagnosis, prediction of prognosis and follow-up after therapy. During the past years, progress has been made in fibrosis detection using MRI. Cardiac infarct size can be assessed noninvasively with late gadolinium enhancement. Several methods for fibrosis detection using endogenous contrast have been developed, such as native T1 -mapping, T1ρ -mapping, Magnetization transfer imaging, and T2 *-mapping. Each of these methods will be described, providing the basic methodology, showing potential applications from applied studies, and discussing the potential and challenges or pitfalls. We will also identify future steps and developments that are needed for bringing these methods to the clinical practice. © 2014 Wiley Periodicals, Inc.

  4. Cumulative phase delay imaging - A new contrast enhanced ultrasound modality

    Energy Technology Data Exchange (ETDEWEB)

    Demi, Libertario, E-mail: l.demi@tue.nl; Sloun, Ruud J. G. van; Mischi, Massimo [Lab. of Biomedical Diagnostics, Dept. of Electrical Eng., Eindhoven University of Technology (Netherlands); Wijkstra, Hessel [Lab. of Biomedical Diagnostics, Dept. of Electrical Eng., Eindhoven University of Technology (Netherlands); Academic Medical Center, Urology Dept., University of Amsterdam (Netherlands)

    2015-10-28

    Recently, a new acoustic marker for ultrasound contrast agents (UCAs) has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental pressure wave field components is in fact observable for ultrasound propagating through UCAs. This phenomenon is absent in the case of tissue nonlinearity and is dependent on insonating pressure and frequency, UCA concentration, and propagation path length through UCAs. In this paper, ultrasound images based on this marker are presented. The ULA-OP research platform, in combination with a LA332 linear array probe (Esaote, Firenze Italy), were used to image a gelatin phantom containing a PVC plate (used as a reflector) and a cylindrical cavity measuring 7 mm in diameter (placed in between the observation point and the PVC plate). The cavity contained a 240 µL/L SonoVueO{sup ®} UCA concentration. Two insonating frequencies (3 MHz and 2.5 MHz) were used to scan the gelatine phantom. A mechanical index MI = 0.07, measured in water at the cavity location with a HGL-0400 hydrophone (Onda, Sunnyvale, CA), was utilized. Processing the ultrasound signals backscattered from the plate, ultrasound images were generated in a tomographic fashion using the filtered back-projection method. As already observed in previous studies, significantly higher CPD values are measured when imaging at a frequency of 2.5 MHz, as compared to imaging at 3 MHz. In conclusion, these results confirm the applicability of the discussed CPD as a marker for contrast imaging. Comparison with standard contrast-enhanced ultrasound imaging modalities will be the focus of future work.

  5. Assessment of subclinical atherosclerosis using contrast-enhanced ultrasound.

    Science.gov (United States)

    van den Oord, Stijn C H; ten Kate, Gerrit L; Akkus, Zeynettin; Renaud, Guillaume; Sijbrands, Eric J G; ten Cate, Folkert J; van der Lugt, Aad; Bosch, Johan G; de Jong, Nico; van der Steen, Antonius F W; Schinkel, Arend F L

    2013-01-01

    The sensitivity of standard carotid ultrasound and colour Doppler for the detection of subclinical atherosclerotic plaques is suboptimal. The aim of this study is to assess whether contrast-enhanced ultrasound (CEUS) added to standard carotid ultrasound improves the detection of subclinical atherosclerosis. Carotid intima-media thickness (CIMT) measurement, standard carotid ultrasound including colour Doppler imaging, and CEUS were performed in 100 asymptomatic patients with one or more risk factors for atherosclerosis. CEUS was performed using intravenous administration of SonoVue™ contrast agent (Bracco S.p.A., Milan, Italy). CIMT, standard ultrasound, colour Doppler, and CEUS were reviewed by two independent observers. Standard ultrasound, colour Doppler, and CEUS were scored for the presence of atherosclerotic plaques. Subclinical atherosclerosis was diagnosed if patients had a CIMT above their age-corrected threshold value or if atherosclerotic plaques were present on standard carotid ultrasound clips or CEUS clips. McNemar's test was performed to compare between groups. Twenty-one patients (21%) had a thickened CIMT value and were considered to have subclinical atherosclerosis. Standard carotid ultrasound including colour Doppler demonstrated atherosclerotic plaques in 77 patients (77%). The addition of CEUS to the standard ultrasound protocol demonstrated atherosclerotic plaques in 88 patients (88%). The incorporation of CEUS into the standard carotid ultrasound protocol resulted in a significantly improved detection of patients with subclinical atherosclerosis (P subclinical atherosclerosis in the carotid arteries. Atherosclerotic plaques which were only detected with CEUS and not with standard carotid ultrasound and colour Doppler imaging were predominantly hypoechoic.

  6. Contrast-enhanced dynamic MR imaging of postmolar gestational trophoblastic disease

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, Y. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Torashima, M. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Takahashi, M. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Mizutani, H. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Miyazaki, K. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Matsuura, K. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan); Okamura, H. [Depts. of Radiology and Obstetrics and Gynecology, Kumamoto Univ. School of Medicine (Japan)

    1995-03-01

    Conventional spin-echo (SE) and contrast-enhanced dynamic MR imaging were performed on a 1.5 T superconductive unit for evaluation of myometrial lesions in postmolar gestational trophoblastic disease (GTD) in 10 women. MR imaging was done at the time of the initial examination (n=10), during (n=6), and after repeated courses of chemotherapy (n=10). The T2-weighted SE image revealed an enlarged uterus (n=7), disappearance of zonal anatomy (n=6), and heterogeneous signal intensities (n=8) with prominent flow voids (n=7). However, these abnormalities remained after repeated courses of chemotherapy, when the S-{beta}-HCG level returned to the normal range. Myometrial lesions characteristically had marked enhancement with areas of unenhancement on dynamic MR images in patients with highly elevated S-{beta}-HCG. Areas of contrast enhancement correlated with changes in S-{beta}-HCG level. The enhancement was reduced with decrease in S-{beta}-HCG level after repeated courses of chemotherapy. Six of 8 masses seen on T2-weighted images proved to be active trophoblastic lesions and 2 masses proved to be hematoma or necrosis. In 2 patients, abnormal myometrial lesions were detected only on contrast-enhanced dynamic MR imaging. These preliminary data indicate that contrast-enhanced dynamic MR imaging more clearly demonstrates myometrial involvement of postmolar GTD than conventional SE imaging. (orig.).

  7. Metabolomics of Breast Cancer Using High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopy: Correlations with 18F-FDG Positron Emission Tomography-Computed Tomography, Dynamic Contrast-Enhanced and Diffusion-Weighted Imaging MRI.

    Directory of Open Access Journals (Sweden)

    Haesung Yoon

    Full Text Available Our goal in this study was to find correlations between breast cancer metabolites and conventional quantitative imaging parameters using high-resolution magic angle spinning (HR-MAS magnetic resonance spectroscopy (MRS and to find breast cancer subgroups that show high correlations between metabolites and imaging parameters.Between August 2010 and December 2013, we included 53 female patients (mean age 49.6 years; age range 32-75 years with a total of 53 breast lesions assessed by the Breast Imaging Reporting and Data System. They were enrolled under the following criteria: breast lesions larger than 1 cm in diameter which 1 were suspicious for malignancy on mammography or ultrasound (US, 2 were pathologically confirmed to be breast cancer with US-guided core-needle biopsy (CNB 3 underwent 3 Tesla MRI with dynamic contrast-enhanced (DCE and diffusion-weighted imaging (DWI and positron emission tomography-computed tomography (PET-CT, and 4 had an attainable immunohistochemistry profile from CNB. We acquired spectral data by HR-MAS MRS with CNB specimens and expressed the data as relative metabolite concentrations. We compared the metabolites with the signal enhancement ratio (SER, maximum standardized FDG uptake value (SUV max, apparent diffusion coefficient (ADC, and histopathologic prognostic factors for correlation. We calculated Spearman correlations and performed a partial least squares-discriminant analysis (PLS-DA to further classify patient groups into subgroups to find correlation differences between HR-MAS spectroscopic values and conventional imaging parameters.In a multivariate analysis, the PLS-DA models built with HR-MAS MRS metabolic profiles showed visible discrimination between high and low SER, SUV, and ADC. In luminal subtype breast cancer, compared to all cases, high SER, ADV, and SUV were more closely clustered by visual assessment. Multiple metabolites were correlated with SER and SUV in all cases. Multiple metabolites

  8. Ablation zone visualization enhancement by periodic contrast-enhancement computed tomography during microwave ablation.

    Science.gov (United States)

    Wu, Po-Hung; Borden, Zachary; Brace, Christopher L

    2017-06-01

    Intra-procedural contrast-enhanced computed tomography (CECT) has been proposed to monitor the growth of thermal ablations. The primary challenge with multiple CT acquisitions is reducing radiation dose while maintaining sufficient image quality. The purpose of this study was to evaluate the feasibility of applying local highly constrained backprojection reconstruction (HYPR-LR) on periodic CECT images acquired with low-dose protocols, and to determine whether the ablations visible on CT were commensurate to gross pathology. Low-dose (CTDIvol≤1.49mGy), temporal CECT volumes were acquired during microwave ablation on normal porcine liver. HYPR processing was performed on each volume after image registration. Ablation signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were collected to evaluate the degree of enhancement of image quality and ablation zone visualization. Ablation zones were manually segmented on HYPR and non-HYPR images and compared spatially using Dice's coefficient. The dimensions of ablation zones were also compared to gross pathology by correlation and dimensional differences. The SNR and CNR of ablation zones were increased after HYPR processing. The manually segmented ablation zone was highly similar to gross pathology with a Dice coefficient of 0.81 ± 0.03, while the low-dose CECT had a smaller Dice coefficient of 0.72 ± 0.05. Both HYPR and low-dose CECT had high correlation to gross pathology (0.99 and 0.94, respectively), but the variance of measurements were lower after HYPR processing compared to unprocessed images. The relative difference in area, length of long axis, and length of short axis for HYPR image were 13.1 ± 5.6%, 9.7 ± 4.2%, and 15.2 ± 2.8%, which were lower than those for low-dose CECT at 37.5 ± 6.0%, 17.7 ± 2.8%, and 28.9 ± 5.4%. HYPR processing applied to periodic CECT images can enhance ablation zone visualization. HYPR processing may potentially enable CECT in real-time ablation monitoring under strict

  9. Biomedical photoacoustics beyond thermal expansion using triggered nanodroplet vaporization for contrast-enhanced imaging.

    Science.gov (United States)

    Wilson, Katheryne; Homan, Kimberly; Emelianov, Stanislav

    2012-01-10

    Since being discovered by Alexander Bell, photoacoustics may again be seeing major resurgence in biomedical imaging. Photoacoustics is a non-ionizing, functional imaging modality capable of high contrast images of optical absorption at depths significantly greater than traditional optical imaging techniques. Optical contrast agents have been used to extend photoacoustics to molecular imaging. Here we introduce an exogenous contrast agent that utilizes vaporization for photoacoustic signal generation, providing significantly higher signal amplitude than that from the traditionally used mechanism, thermal expansion. Our agent consists of liquid perfluorocarbon nanodroplets with encapsulated plasmonic nanoparticles, entitled photoacoustic nanodroplets. Upon pulsed laser irradiation, liquid perfluorocarbon undergoes a liquid-to-gas phase transition generating giant photoacoustic transients from these dwarf nanoparticles. Once triggered, the gaseous phase provides ultrasound contrast enhancement. We demonstrate in phantom and animal studies that photoacoustic nanodroplets act as dual-contrast agents for both photoacoustic and ultrasound imaging through optically triggered vaporization.

  10. Dual-mode registration of dynamic contrast-enhanced ultrasound combining tissue and contrast sequences.

    Science.gov (United States)

    Bouhlel, Nizar; Coron, Alain; Barrois, Guillaume; Lucidarme, Olivier; Bridal, S Lori

    2014-07-01

    This study proposes a new method for automatic, iterative image registration in the context of dynamic contrast-enhanced ultrasound (DCE-US) imaging. By constructing a cost function of image registration using a combination of the tissue and contrast-microbubble responses, this new method, referred to as dual-mode registration, performs alignment based on both tissue and vascular structures. Data from five focal liver lesions (FLLs) were used for the evaluation. Automatic registration based on the dual-mode registration technique and tissue-mode registration obtained using the linear response image sequence alone were compared to manual alignment of the sequence by an expert. Comparison of the maximum distance between the transformations applied by the automatic registration techniques and those from expert manual registration reference showed that the dual-mode registration provided better precision than the tissue-mode registration for all cases. The reduction of maximum distance ranged from 0.25 to 9.3mm. Dual-mode registration is also significantly better than tissue-mode registration for the five sequences with p-values lower than 0.03. The improved sequence alignment is also demonstrated visually by comparison of images from the sequences and the video playbacks of the motion-corrected sequences. This new registration technique better maintains a selected region of interest (ROI) within a fixed position of the image plane throughout the DCE-US sequence. This should reduce motion-related variability of the echo-power estimations and, thus, contribute to more robust perfusion quantification with DCE-US. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Contrast-enhanced ultrsonography advanced and currrent status in abdominal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chung Yong Eun; Kim Ki Whang [Dept. of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-01-15

    n the field of contrast-enhanced ultrasonography (US), contrast agents are classified as either first- or second-generation agents depending on the gas within the microbubbles. In the case of first-generation contrast agents, a high-mechanical-index technique is used and only intermittent scanning is possible due to the early destruction of the microbubbles during the scanning. The use of second-generation contrast agents in a low-mechanical-index technique enables continuous scanning. Besides the detection and characterization of focal liver lesions, contrastenhanced US is helpful in the monitoring of radiofrequency ablation therapy and in the targeting step of an US-guided biopsy. Recently, there has been a demand for new criteria to evaluate the treatment response obtained using anti-angiogenic agents because morphologic criteria alone may not reflect the treatment response of the tumor and contrast-enhanced US can provide quantitative markers of tissue perfusion. In spite of the concerns related to its cost-effectiveness, contrast-enhanced US has the potential to be more widely used as a complimentary tool or to substitute the current imaging modalities in some occasions.

  12. Segmentation methods for breast vasculature in dual-energy contrast-enhanced digital breast tomosynthesis

    Science.gov (United States)

    Lau, Kristen C.; Lee, Hyo Min; Singh, Tanushriya; Maidment, Andrew D. A.

    2015-03-01

    Dual-energy contrast-enhanced digital breast tomosynthesis (DE CE-DBT) uses an iodinated contrast agent to image the three-dimensional breast vasculature. The University of Pennsylvania has an ongoing DE CE-DBT clinical study in patients with known breast cancers. The breast is compressed continuously and imaged at four time points (1 pre-contrast; 3 post-contrast). DE images are obtained by a weighted logarithmic subtraction of the high-energy (HE) and low-energy (LE) image pairs. Temporal subtraction of the post-contrast DE images from the pre-contrast DE image is performed to analyze iodine uptake. Our previous work investigated image registration methods to correct for patient motion, enhancing the evaluation of vascular kinetics. In this project we investigate a segmentation algorithm which identifies blood vessels in the breast from our temporal DE subtraction images. Anisotropic diffusion filtering, Gabor filtering, and morphological filtering are used for the enhancement of vessel features. Vessel labeling methods are then used to distinguish vessel and background features successfully. Statistical and clinical evaluations of segmentation accuracy in DE-CBT images are ongoing.

  13. Multiresolution Local Contrast Enhancement of X-Ray Images for Poultry Meat Inspection

    Science.gov (United States)

    Chen, Zikuan; Tao, Yang; Chen, Xin

    2001-03-01

    A multiresolution-analysis-based local contrast transform is proposed to enhance local structures in x-ray images. The local contrast is defined as a ratio of the local intensity variation to the local mean. With wavelet multiresolution decomposition, the detail coefficients and approximation coefficients are interpreted, respectively, as local variations and local averages in virtue of the localization property of wavelet transform. Based on the local contrast transform, an algorithm is developed to modify coefficients before wavelet synthesis. An across-scale local contrast is obtained when the scale associated with the local variation is different from that of the local mean. The nonlinearity and local adaptiveness properties of local contrast transform result in structural enhancement in local dark regions in the reconstructed images. We applied this technique to deboned poultry inspection using x-ray images. Because of its high x-ray absorption, a foreign inclusion appears as a low-intensity object in an x-ray image, thus resulting in contrast enhancement in the reconstructed multiresolution images.

  14. Role of Contrast-Enhanced Ultrasound in the Follow-up of Kidney Transplant Patients.

    Science.gov (United States)

    Korda, D; Deák, P Á; Kozma, V; Kiss, G; Doros, A

    2016-09-01

    Contrast-enhanced ultrasound combines the advantages of native ultrasound and other contrast-enhanced imaging modalities. In selected cases it can be preferable to computerized tomographic scan among kidney transplant recipients. We performed a retrospective study involving patients of Semmelweis University Department of Transplantation and Surgery who underwent contrast-enhanced ultrasound examination from 2011 to 2015. During this period, 251 examinations were performed, including 45 on kidney transplant patients. A Toshiba Aplio XU ultrasound device was used, and 1-1.5 mL contrast agent (Sonovue) was administered intravenously for each patient. The indications of these evaluations can be divided into 3 groups: characterization of circumscribed kidney lesions, control after radiofrequency ablation therapy, and examination of graft perfusion. Fully 93% of the examinations were conclusive. In the 1st group of the 37 cases where tumor-suspect lesions were investigated, 13 examinations suggested the presence of a space-occupying lesion. Of those 13 cases, 2 patients had a negative biopsy, nephrectomy was performed in 11 cases, and histologic evaluation verified a tumor in 8 samples. In the 2nd group, the ablation control examination detected a residual tumor in none of the 6 cases. Finally, in 1 of the 2 grafts where the circulation was investigated, blood flow was satisfactory, and in the other it was low. The contrast-enhanced ultrasound examination was conclusive in most cases. The applied contrast material is not nephrotoxic, and the method uses nonionizing radiation. These features make contrast-enhanced ultrasound highly suitable for the examination of kidney transplant patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Dynamic Contrast-Enhanced MRI of Cervical Cancers: Temporal Percentile Screening of Contrast Enhancement Identifies Parameters for Prediction of Chemoradioresistance

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Erlend K.F. [Department of Medical Physics, Oslo University Hospital, Oslo (Norway); Hole, Knut Hakon; Lund, Kjersti V. [Department of Radiology, Oslo University Hospital, Oslo (Norway); Sundfor, Kolbein [Department of Gynaecological Oncology, Oslo University Hospital, Oslo (Norway); Kristensen, Gunnar B. [Department of Gynaecological Oncology, Oslo University Hospital, Oslo (Norway); Institute for Medical Informatics, Oslo University Hospital, Oslo (Norway); Lyng, Heidi [Department of Radiation Biology, Oslo University Hospital, Oslo (Norway); Malinen, Eirik, E-mail: eirik.malinen@fys.uio.no [Department of Medical Physics, Oslo University Hospital, Oslo (Norway); Department of Physics, University of Oslo, Oslo (Norway)

    2012-03-01

    Purpose: To systematically screen the tumor contrast enhancement of locally advanced cervical cancers to assess the prognostic value of two descriptive parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Methods and Materials: This study included a prospectively collected cohort of 81 patients who underwent DCE-MRI with gadopentetate dimeglumine before chemoradiotherapy. The following descriptive DCE-MRI parameters were extracted voxel by voxel and presented as histograms for each time point in the dynamic series: normalized relative signal increase (nRSI) and normalized area under the curve (nAUC). The first to 100th percentiles of the histograms were included in a log-rank survival test, resulting in p value and relative risk maps of all percentile-time intervals for each DCE-MRI parameter. The maps were used to evaluate the robustness of the individual percentile-time pairs and to construct prognostic parameters. Clinical endpoints were locoregional control and progression-free survival. The study was approved by the institutional ethics committee. Results: The p value maps of nRSI and nAUC showed a large continuous region of percentile-time pairs that were significantly associated with locoregional control (p < 0.05). These parameters had prognostic impact independent of tumor stage, volume, and lymph node status on multivariate analysis. Only a small percentile-time interval of nRSI was associated with progression-free survival. Conclusions: The percentile-time screening identified DCE-MRI parameters that predict long-term locoregional control after chemoradiotherapy of cervical cancer.

  16. Diagnostic value of contrast-enhanced ultrasound in solid thyroid nodules with and without enhancement.

    Science.gov (United States)

    Wu, Qiong; Wang, Yan; Li, Yi; Hu, Bing; He, Zhi-Yan

    2016-08-01

    We aimed to investigate different enhancement patterns of solid thyroid nodules on contrast-enhanced ultrasound (CEUS) and then to evaluate the corresponding diagnostic performance in the differentiation of benign and malignant nodules with and without enhancement. 229 solid thyroid nodules in 196 patients who had undergone both conventional ultrasound and CEUS examinations were classified into enhancement and non-enhancement groups. Besides, different enhancement patterns in the enhancement group were characterised with five indicators including arrival time, mode of entrance, echo intensity, homogeneity, and washout time. Then aforementioned indicators were compared between benign and malignant nodules of different sizes (10 mm), and diagnostic performance of significant enhancement indicators was calculated. As for the enhancement group, there were statistically significant differences of predictive value of non-enhancement were 95.51 and 95.83 %, respectively, with an accuracy of 77.29 %. CEUS is a very promising diagnostic technique that could improve the diagnostic accuracy of identifying benign thyroid lesions to spare a large number of patients an unnecessary invasive procedure.

  17. Generation And Measurement Of High Contrast Ultrashort Intense Laser Pulses

    CERN Document Server

    Konoplev, O A

    2000-01-01

    In this thesis, the generation and measurement of high contrast, intense, ultrashort pulses have been studied. Various factors affecting the contrast and pulse shape of ultrashort light pulses from a chirped pulse amplification (CPA) laser system are identified. The level of contrast resulting from influence of these factors is estimated. Methods for improving and controlling the pulse shape and increasing the contrast are discussed. Ultrahigh contrast, 1-ps pulses were generated from a CPA system with no temporal structure up to eleven orders of magnitude. This is eight orders of magnitude higher contrast than the original pulse. This contrast boost was achieved using two techniques. One is the optical pulse cleaning based on the nonlinear birefringence of the chirping fiber and applied to the pulses before amplification. The other is the fast saturable absorber. The fast saturable absorber was placed after amplification and compression of the pulse. The measurements of high-contrast, ultrashort pulse with h...

  18. Enhancing contrast of magnetic resonance imaging in patients with ...

    African Journals Online (AJOL)

    DTPA), a recent magnetic resonance imaging (MRI) contrast agent, in hepatobiliary system of patients with liver cirrhosis. Methods: Liver cirrhosis patients that underwent contrast MRI examination at Renai Hospital, Taipei City, Taiwan were ...

  19. Quantitative evaluation of contrast agent uptake in standard fat-suppressed dynamic contrast-enhanced MRI examinations of the breast.

    Science.gov (United States)

    Kousi, Evanthia; Smith, Joely; Ledger, Araminta E; Scurr, Erica; Allen, Steven; Wilson, Robin M; O'Flynn, Elizabeth; Pope, Romney J E; Leach, Martin O; Schmidt, Maria A

    2018-01-01

    To propose a method to quantify T 1 and contrast agent uptake in breast dynamic contrast-enhanced (DCE) examinations undertaken with standard clinical fat-suppressed MRI sequences and to demonstrate the proposed approach by comparing the enhancement characteristics of lobular and ductal carcinomas. A standard fat-suppressed DCE of the breast was performed at 1.5 T (Siemens Aera), followed by the acquisition of a proton density (PD)-weighted sequence, also fat suppressed. Both sequences were characterized with test objects (T 1 ranging from 30 ms to 2,400 ms) and calibration curves were obtained to enable T 1 calculation. The reproducibility and accuracy of the calibration curves were also investigated. Healthy volunteers and patients were scanned with Ethics Committee approval. The effect of B 0 field inhomogeneity was assessed in test objects and healthy volunteers. The T 1 of breast tumors was calculated at different time points (pre-, peak-, and post-contrast agent administration) for 20 patients, pre-treatment (10 lobular and 10 ductal carcinomas) and the two cancer types were compared (Wilcoxon rank-sum test). The calibration curves proved to be highly reproducible (coefficient of variation under 10%). T 1 measurements were affected by B 0 field inhomogeneity, but frequency shifts below 50 Hz introduced only 3% change to fat-suppressed T 1 measurements of breast parenchyma in volunteers. The values of T 1 measured pre-, peak-, and post-contrast agent administration demonstrated that the dynamic range of the DCE sequence was correct, that is, image intensity is approximately directly proportional to 1/T 1 for that range. Significant differences were identified in the width of the distributions of the post-contrast T 1 values between lobular and ductal carcinomas (P work has demonstrated the feasibility of fat-suppressed T 1 measurements as a tool for clinical studies. The proposed quantitative approach is practical, enabled the detection of differences between

  20. Multivalent, high-relaxivity MRI contrast agents using rigid cysteine-reactive gadolinium complexes.

    Science.gov (United States)

    Garimella, Praveena D; Datta, Ankona; Romanini, Dante W; Raymond, Kenneth N; Francis, Matthew B

    2011-09-21

    MRI contrast agents providing very high relaxivity values can be obtained through the attachment of multiple gadolinium(III) complexes to the interior surfaces of genome-free viral capsids. In previous studies, the contrast enhancement was predicted to depend on the rigidity of the linker attaching the MRI agents to the protein surface. To test this hypothesis, a new set of Gd-hydroxypyridonate based MRI agents was prepared and attached to genetically introduced cysteine residues through flexible and rigid linkers. Greater contrast enhancements were seen for MRI agents that were attached via rigid linkers, validating the design concept and outlining a path for future improvements of nanoscale MRI contrast agents.

  1. Characterization of D-maltose as a T2-exchange contrast agent for dynamic contrast-enhanced MRI.

    Science.gov (United States)

    Goldenberg, Joshua M; Pagel, Mark D; Cárdenas-Rodríguez, Julio

    2018-01-25

    We sought to investigate the potential of D-maltose, D-sorbitol, and D-mannitol as T 2 exchange magnetic resonance imaging (MRI) contrast agents. We also sought to compare the in vivo pharmacokinetics of D-maltose with D-glucose with dynamic contrast enhancement (DCE) MRI. T 1 and T 2 relaxation time constants of the saccharides were measured using eight pH values and nine concentrations. The effect of echo spacing in a multiecho acquisition sequence used for the T 2 measurement was evaluated for all samples. Finally, performances of D-maltose and D-glucose during T 2 -weighted DCE-MRI were compared in vivo. Estimated T 2 relaxivities (r 2 ) of D-glucose and D-maltose were highly and nonlinearly dependent on pH and echo spacing, reaching their maximum at pH = 7.0 (∼0.08 mM -1 s -1 ). The r 2 values of D-sorbitol and D-mannitol were estimated to be ∼0.02 mM -1 s -1 and were invariant to pH and echo spacing for pH ≤7.0. The change in T 2 in tumor and muscle tissues remained constant after administration of D-maltose, whereas the change in T 2 decreased in tumor and muscle after administration of D-glucose. Therefore, D-maltose has a longer time window for T 2 -weighted DCE-MRI in tumors. We have demonstrated that D-maltose can be used as a T 2 exchange MRI contrast agent. The larger, sustained T 2 -weighted contrast from D-maltose relative to D-glucose has practical advantages for tumor diagnoses during T 2 -weighted DCE-MRI. Magn Reson Med, 2018. © 2018 International Society for Magnetic Resonance in Medicine. © 2018 International Society for Magnetic Resonance in Medicine.

  2. Reduced-Contrast Approximations for High-Contrast Multiscale Flow Problems

    KAUST Repository

    Chung, Eric T.

    2010-01-01

    In this paper, we study multiscale methods for high-contrast elliptic problems where the media properties change dramatically. The disparity in the media properties (also referred to as high contrast in the paper) introduces an additional scale that needs to be resolved in multiscale simulations. First, we present a construction that uses an integral equation to represent the highcontrast component of the solution. This representation involves solving an integral equation along the interface where the coefficients are discontinuous. The integral representation suggests some multiscale approaches that are discussed in the paper. One of these approaches entails the use of interface functions in addition to multiscale basis functions representing the heterogeneities without high contrast. In this paper, we propose an approximation for the solution of the integral equation using the interface problems in reduced-contrast media. Reduced-contrast media are obtained by lowering the variance of the coefficients. We also propose a similar approach for the solution of the elliptic equation without using an integral representation. This approach is simpler to use in the computations because it does not involve setting up integral equations. The main idea of this approach is to approximate the solution of the high-contrast problem by the solutions of the problems formulated in reduced-contrast media. In this approach, a rapidly converging sequence is proposed where only problems with lower contrast are solved. It was shown that this sequence possesses the convergence rate that is inversely proportional to the reduced contrast. This approximation allows choosing the reduced-contrast problem based on the coarse-mesh size as discussed in this paper. We present a simple application of this approach to homogenization of elliptic equations with high-contrast coefficients. The presented approaches are limited to the cases where there are sharp changes in the contrast (i.e., the high

  3. Hepatic hemangioma: contrast enhancement patterns on two-phase spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Eun Joo; Choi, Byung Ihn; Han, Joon Koo; Jang, Hyun Jung; Kim, Tae Kyoung; Kim, Ah Young; Lee, Ki Yeol [Seoul National Univ., Seoul (Korea, Republic of). Coll. of Medicine

    1998-01-01

    To evaluate contrast enhancement patterns of hemangioma according to size, as seen during the arterial and portal venous phase of spiral CT. Overall, the most common enhancement pattern was peripheral high (44/82, 53.7%), during the arterial and portal venous phase. The second and third most common patterns were uniform high (11/82, 13.4%) and peripheral high-uniform high (9/82, 11.0%), also during the arterial and portal venous phase. In tumors smaller than 20 mm, low-low attenuation was seen in eight (9.8%), and iso-low attenuation in two (2.4%), during the arterial and portal venous phase, respectively. On two-phase spiral CT, the most common enhancement pattern of hemangioma was peripheral high, seen during the arterial and portal venous phase. However, a small hemangioma less than 2cm may show atypical patterns, including low and iso attenuation. (author). 23 refs., 1 tab., 4 figs.

  4. CONTRAST

    DEFF Research Database (Denmark)

    Kristensen, Thomas Krogsgaard

    2007-01-01

    Dette er en afrapportering fra den årlige CONTRAST workshop, der i 2007 blev afholdt i Yaoundé, Cameroon.......Dette er en afrapportering fra den årlige CONTRAST workshop, der i 2007 blev afholdt i Yaoundé, Cameroon....

  5. Feasibility of concurrent dual contrast enhancement using CEST contrast agents and superparamagnetic iron oxide particles.

    NARCIS (Netherlands)

    Gilad, A.A.; Laarhoven, H.W.M. van; McMahon, M.T.; Walczak, P.; Heerschap, A.; Neeman, M.; Zijl, P.C. van; Bulte, J.W.

    2009-01-01

    A major challenge for cellular and molecular MRI is to study interactions between two different cell populations or biological processes. We studied the possibility to simultaneously image contrast agents based on two different MRI contrast mechanisms: chemical exchange saturation transfer (CEST)

  6. Feasibility of concurrent dual contrast enhancement using CEST contrast agents and superparamagnetic iron oxide particles

    NARCIS (Netherlands)

    Gilad, Assaf A.; van Laarhoven, Hanneke W. M.; McMahon, Michael T.; Walczak, Piotr; Heerschap, Arend; Neeman, Michal; van Zijl, Peter C. M.; Bulte, Jeff W. M.

    2009-01-01

    A major challenge for cellular and molecular MRI is to study interactions between two different cell populations or biological processes. We studied the possibility to simultaneously image contrast agents based on two different MRI contrast mechanisms: chemical exchange saturation transfer (CEST)

  7. Post-radiotherapy contrast enhancement changes in fast dynamic MRI of cervical carcinoma.

    NARCIS (Netherlands)

    Boss, E.A.; Massuger, L.F.A.G.; Pop, L.A.M.; Verhoef, C.G.; Huisman, H.J.; Boonstra, H.; Barentsz, J.O.

    2001-01-01

    This pilot study determines fast dynamic gadolinium enhanced MRI contrast enhancement parameters (onset of enhancement and time to peak enhancement) before and after radiotherapy in 10 cervical carcinoma patients. Before radiotherapy, onset of enhancement and time to peak enhancement were early,

  8. Microarray Gene Expression Analysis of Murine Tumor Heterogeneity Defined by Dynamic Contrast-Enhanced MRI

    Directory of Open Access Journals (Sweden)

    Nick G. Costouros

    2002-07-01

    Full Text Available Current methods of studying angiogenesis are limited in their ability to serially evaluate in vivo function throughout a target tissue. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI and pharmacokinetic modeling provide a useful method for evaluating tissue vasculature based on contrast accumulation and washout. While it is often assumed that areas of high contrast enhancement and washout comprise areas of increased angiogenesis and tumor activity, the actual molecular pathways that are active in such areas are poorly understood. Using DCE-MRI in a murine subcutaneous tumor model, we were able to perform pharmacokinetic functional analysis of a tumor, coregistration of MRI images with histological cross-sections, immunohistochemistry, laser capture microdissection, and genetic profiling of tumor heterogeneity based on pharmacokinetic parameters. Using imaging as a template for biologic investigation, we have not found evidence of increased expression of proangiogenic modulators at the transcriptional level in either distinct pharmacokinetic region. Furthermore, these regions show no difference on histology and CD31 immunohistochemistry. However, the expression of ribosomal proteins was greatly increased in high enhancement and washout regions, implying increased protein translation and consequent increased cellular activity. Together, these findings point to the potential importance of posttranscriptional regulation in angiogenesis and the need for the development of angiogenesis-specific contrast agents to evaluate in vivo angiogenesis at a molecular level.

  9. Differentiation of breast cancer from fibroadenoma with dual-echo dynamic contrast-enhanced MRI.

    Science.gov (United States)

    Wang, Shiwei; Delproposto, Zachary; Wang, Haoyu; Ding, Xuewei; Ji, Conghua; Wang, Bei; Xu, Maosheng

    2013-01-01

    Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) of the breast is a routinely used imaging method which is highly sensitive for detecting breast malignancy. Specificity, though, remains suboptimal. Dynamic susceptibility contrast magnetic resonance imaging (DSC MRI), an alternative dynamic contrast imaging technique, evaluates perfusion-related parameters unique from DCE MRI. Previous work has shown that the combination of DSC MRI with DCE MRI can improve diagnostic specificity, though an additional administration of intravenous contrast is required. Dual-echo MRI can measure both T1W DCE MRI and T2*W DSC MRI parameters with a single contrast bolus, but has not been previously implemented in breast imaging. We have developed a dual-echo gradient-echo sequence to perform such simultaneous measurements in the breast, and use it to calculate the semi-quantitative T1W and T2*W related parameters such as peak enhancement ratio, time of maximal enhancement, regional blood flow, and regional blood volume in 20 malignant lesions and 10 benign fibroadenomas in 38 patients. Imaging parameters were compared to surgical or biopsy obtained tissue samples. Receiver operating characteristic (ROC) curves and area under the ROC curves were calculated for each parameter and combination of parameters. The time of maximal enhancement derived from DCE MRI had a 90% sensitivity and 69% specificity for predicting malignancy. When combined with DSC MRI derived regional blood flow and volume parameters, sensitivity remained unchanged at 90% but specificity increased to 80%. In conclusion, we show that dual-echo MRI with a single administration of contrast agent can simultaneously measure both T1W and T2*W related perfusion and kinetic parameters in the breast and the combination of DCE MRI and DSC MRI parameters improves the diagnostic performance of breast MRI to differentiate breast cancer from benign fibroadenomas.

  10. Intravascular enhancement with identical iodine delivery rate using different iodine contrast media in a circulation phantom.

    Science.gov (United States)

    Mihl, Casper; Wildberger, Joachim E; Jurencak, Tomas; Yanniello, Michael J; Nijssen, Estelle C; Kalafut, John F; Nalbantov, Georgi; Mühlenbruch, Georg; Behrendt, Florian F; Das, Marco

    2013-11-01

    Both iodine delivery rate (IDR) and iodine concentration are decisive factors for vascular enhancement in computed tomographic angiography. It is unclear, however, whether the use of high-iodine concentration contrast media is beneficial to lower iodine concentrations when IDR is kept identical. This study evaluates the effect of using different iodine concentrations on intravascular attenuation in a circulation phantom while maintaining a constant IDR. A circulation phantom with a low-pressure venous compartment and a high-pressure arterial compartment simulating physiological circulation parameters was used (heart rate, 60 beats per minute; stroke volume, 60 mL; blood pressure, 120/80 mm Hg). Maintaining a constant IDR (2.0 g/s) and a constant total iodine load (20 g), prewarmed (37°C) contrast media with differing iodine concentrations (240-400 mg/mL) were injected into the phantom using a double-headed power injector. Serial computed tomographic scans at the level of the ascending aorta (AA), the descending aorta (DA), and the left main coronary artery (LM) were obtained. Total amount of contrast volume (milliliters), iodine delivery (grams of iodine), peak flow rate (milliliter per second), and intravascular pressure (pounds per square inch) were monitored using a dedicated data acquisition program. Attenuation values in the AA, the DA, and the LM were constantly measured (Hounsfield unit [HU]). In addition, time-enhancement curves, aortic peak enhancement, and time to peak were determined. All contrast injection protocols resulted in similar attenuation values: the AA (516 [11] to 531 [37] HU), the DA (514 [17] to 531 [32] HU), and the LM (490 [10] to 507 [17] HU). No significant differences were found between the AA, the DA, and the LM for either peak enhancement (all P > 0.05) or mean time to peak (AA, 19.4 [0.58] to 20.1 [1.05] seconds; DA, 21.1 [1.0] to 21.4 [1.15] seconds; LM, 19.8 [0.58] to 20.1 [1.05] seconds). This phantom study demonstrates that

  11. Fusion of contrast-enhanced breast MR and mammographic imaging data.

    Science.gov (United States)

    Behrenbruch, Christian P; Marias, Kostas; Armitage, Paul A; Yam, Margaret; Moore, Niall; English, Ruth E; Clarke, Jane; Brady, Michael

    2003-09-01

    Increasing use is being made of Gd-DTPA contrast-enhanced magnetic resonance imaging for breast cancer assessment since it provides 3D functional information via pharmacokinetic interaction between contrast agent and tumour vascularity, and because it is applicable to women of all ages as well as patients with post-operative scarring. Contrast-enhanced MRI (CE-MRI) is complementary to conventional X-ray mammography, since it is a relatively low-resolution functional counterpart of a comparatively high-resolution 2D structural representation. However, despite the additional information provided by MRI, mammography is still an extremely important diagnostic imaging modality, particularly for several common conditions such as ductal carcinoma in situ (DCIS) where it has been shown that there is a strong correlation between microcalcification clusters and malignancy. Pathological indicators such as calcifications and fine spiculations are not visible in CE-MRI and therefore there is clinical and diagnostic value in fusing the high-resolution structural information available from mammography with the functional data acquired from MRI imaging. This paper presents a novel data fusion technique whereby medial-lateral oblique (MLO) and cranial-caudal (CC) mammograms (2D data) are registered to 3D contrast-enhanced MRI volumes. We utilise a combination of pharmacokinetic modelling, projection geometry, wavelet-based landmark detection and thin-plate spline non-rigid 'warping' to transform the coordinates of regions of interest (ROIs) from the 2D mammograms to the spatial reference frame of the contrast-enhanced MRI volume. Of key importance is the use of a flexible wavelet-based feature extraction technique that enables feature correspondences to be robustly determined between the very different image characteristics of X-ray mammography and MRI. An evaluation of the fusion framework is demonstrated with a series of clinical cases and a total of 14 patient examples.

  12. Contrast-enhanced digital holographic imaging of cellular structures by manipulating the intracellular refractive index.

    Science.gov (United States)

    Rommel, Christina E; Dierker, Christian; Schmidt, Lisa; Przibilla, Sabine; von Bally, Gert; Kemper, Björn; Schnekenburger, Jürgen

    2010-01-01

    The understanding of biological reactions and evaluation of the significance for living cells strongly depends on the ability to visualize and quantify these processes. Digital holographic microscopy (DHM) enables quantitative phase contrast imaging for high resolution and minimal invasive live cell analysis without the need of labeling or complex sample preparation. However, due to the rather homogeneous intracellular refractive index, the phase contrast of subcellular structures is limited and often low. We analyze the impact of the specific manipulation of the intracellular refractive index by microinjection on the DHM phase contrast. Glycerol is chosen as osmolyte, which combines high solubility in aqueous solutions and biological compatibility. We show that the intracellular injection of glycerol causes a contrast enhancement that can be explained by a decrease of the cytosolic refractive index due to a water influx. The underlying principle is proven by experiments inducing cell shrinkage and with fixated cells. The integrity of the cell membrane is considered as a prerequisite and allows a reversible cell swelling and shrinking within a certain limit. The presented approach to control the intracellular phase contrast demonstrated for the example of DHM opens prospects for applications with other quantitative phase contrast imaging methods.

  13. Evaluation of hepatic contrast enhancement with a hepatocyte-specific magnetic resonance imaging contrast agent (gadoxetic acid) in healthy dogs.

    Science.gov (United States)

    Bratton, Alexandra K; Nykamp, Stephanie G; Gibson, Thomas W G; Cruz-Arámbulo, Robert; Kruth, Stephen A

    2015-03-01

    To determine, by means of MRI, the time to maximal contrast enhancement in T1-weighted images following IV administration of gadoxetic acid in healthy dogs and assess the impact of gadoxetic acid on the signal intensity of T2-weighted images. 7 healthy dogs. No hepatic abnormalities were detected during ultrasonographic examination. Each dog was anesthetized and positioned in dorsal recumbency for MRI. Transverse T1- and T2-weighted images of the liver were acquired prior to and following (at 5-minute intervals) IV injection of 0.1 mL of gadoxetic acid/kg. Signal intensity of the liver parenchyma was measured in 3 regions of interest in the T1- and T2-weighted images before and at various times point after contrast agent administration. Time versus signal-to-noise ratio curves were plotted to determine time to maximal contrast enhancement and contrast agent-related changes in signal intensity in T2-weighted images. Analysis of T1-weighted images revealed that mean ± SD time to maximal enhancement after gadoxetic acid injection was 10.5 ± 3.99 minutes. Signal intensity of T2-weighted images was not significantly affected by gadoxetic acid administration. No injection-related adverse effects were observed in any dog. Results indicated that gadoxetic acid can be used for hepatic MRI in healthy dogs and the resultant hepatic enhancement patterns are similar to those described for humans. Maximal contrast enhancement occurred between 10 and 15 minutes after contrast agent injection; thus, T2-weighted images may be obtained in the interval between injection and maximal enhancement for a more time-efficient clinical protocol.

  14. A new combined technique for automatic contrast enhancement of digital images

    Directory of Open Access Journals (Sweden)

    Ismail A. Humied

    2012-03-01

    Full Text Available Some low contrast images have certain characteristics makes it difficult to use traditional methods to improve it. An example of these characteristics, that the amplitudes of images histogram components are very high at one location on the gray scale and very small in the rest of the gray scale. In the present paper, a new method is described. It can deal with such cases. The proposed method is a combination of Histogram Equalization (HE and Fast Gray-Level Grouping (FGLG. The basic procedure of this method is segments the original histogram of a low contrast image into two sub-histograms according to the location of the highest amplitude of the histogram components, and achieving contrast enhancement by equalizing the left segment of the histogram components using (HE technique and using (FGLG technique to equalize the right segment of this histogram components. The results have shown that the proposed method does not only produce better results than each individual contrast enhancement technique, but it is also fully automated. Moreover, it is applicable to a broad variety of images that satisfy the properties mentioned above and suffer from low contrast.

  15. Preliminary studies of enhanced contrast radiography in anatomy and embryology of insects with Elettra synchrotron light

    Science.gov (United States)

    Hönnicke, M. G.; Foerster, L. A.; Navarro-Silva, M. A.; Menk, R.-H.; Rigon, L.; Cusatis, C.

    2005-08-01

    Enhanced contrast X-ray imaging is achieved by exploiting the real part of the refraction index, which is responsible for the phase shifts, in addition to the imaginary part, which is responsible for the absorption. Such techniques are called X-ray phase contrast imaging. An analyzer-based X-ray phase contrast imaging set-up with Diffraction Enhanced Imaging processing (DEI) were used for preliminary studies in anatomy and embryology of insects. Parasitized stinkbug and moth eggs used as control agents of pests in vegetables and adult stinkbugs and mosquitoes ( Aedes aegypti) were used as samples. The experimental setup was mounted in the SYRMEP beamline at ELETTRA. Images were obtained using a high spatial resolution CCD detector (pixel size 14×14 μm 2) coupled with magnifying optics. Analyzer-based X-ray phase contrast images (PCI) and edge detection images show contrast and details not observed with conventional synchrotron radiography and open the possibility for future study in the embryonic development of insects.

  16. Preliminary studies of enhanced contrast radiography in anatomy and embryology of insects with Elettra synchrotron light

    Energy Technology Data Exchange (ETDEWEB)

    Hoennicke, M.G. [Departamento de Fisica, Universidade Federal do Parana, Caixa Postal 19091, 81531-990 Curitiba-PR (Brazil)]. E-mail: marcelo@fisica.ufpr.br; Foerster, L.A. [Departamento de Zoologia, Universidade Federal do Parana, Caixa Postal 19020, 81531-990 Curitiba-PR (Brazil); Navarro-Silva, M.A. [Departamento de Zoologia, Universidade Federal do Parana, Caixa Postal 19020, 81531-990 Curitiba-PR (Brazil); Menk, R.-H. [Sincrotrone Trieste SCpA, Strada Statale S.S. 14 km 163.5, 34012 Basovizza, Trieste (Italy); Rigon, L. [Dipartamento di Fisica, Universita di Trieste, Via Valerio 2, 34100, Trieste Italy (Italy); Cusatis, C. [Departamento de Fisica, Universidade Federal do Parana, Caixa Postal 19091, 81531-990 Curitiba-PR (Brazil)

    2005-08-11

    Enhanced contrast X-ray imaging is achieved by exploiting the real part of the refraction index, which is responsible for the phase shifts, in addition to the imaginary part, which is responsible for the absorption. Such techniques are called X-ray phase contrast imaging. An analyzer-based X-ray phase contrast imaging set-up with Diffraction Enhanced Imaging processing (DEI) were used for preliminary studies in anatomy and embryology of insects. Parasitized stinkbug and moth eggs used as control agents of pests in vegetables and adult stinkbugs and mosquitoes (Aedes aegypti) were used as samples. The experimental setup was mounted in the SYRMEP beamline at ELETTRA. Images were obtained using a high spatial resolution CCD detector (pixel size 14x14{mu}m{sup 2}) coupled with magnifying optics. Analyzer-based X-ray phase contrast images (PCI) and edge detection images show contrast and details not observed with conventional synchrotron radiography and open the possibility for future study in the embryonic development of insects.

  17. Comparison between survey radiography, B-mode ultrasonography, contrast-enhanced ultrasonography and contrast-enhanced multi-detector computed tomography findings in dogs with acute abdominal signs.

    Science.gov (United States)

    Shanaman, Miriam M; Schwarz, Tobias; Gal, Arnon; O'Brien, Robert T

    2013-01-01

    Contrast-enhanced multi-detector computed tomography (CE-MDCT) is used routinely in evaluating human patients with acute abdominal symptoms. Contrast-enhanced ultrasound (CEUS) continues to be in its infancy as it relates to evaluation of the acute abdomen. The purpose of this study was to compare survey radiography, B-mode ultrasound, CEUS, and CE-MDCT findings in canine patients presenting with acute abdominal signs; with a focus on the ability to differentiate surgical from non-surgical conditions. Nineteen dogs were prospectively enrolled. Inclusion required a clinical diagnosis of acute abdominal signs and confirmed surgical or non-surgical causes for the clinical signs. Agreement for the majority of recorded imaging features was at least moderate. There was poor agreement in the identification of pneumoperitoneum and in the comparison of pancreatic lesion dimensions for B-mode vs. CEUS. The CT feature of fat stranding was detected in cases including, but not limited to, gastric neoplasia with perforation, pancreatitis, and small intestinal foreign body. Ultrasound underestimated the size and number of specific lesions when compared with CE-MDCT. Contrast-enhanced ultrasound was successful in detecting bowel and pancreatic perfusion deficits that CE-MDCT failed to identify. Accuracy for differentiation of surgical vs. non-surgical conditions was high for all modalities; 100%, 94%, and 94% for CE-MDCT, ultrasonography and survey radiography respectively. Findings indicated that CE-MDCT is an accurate screening test for differentiating surgical from non-surgical acute abdominal conditions in dogs. Focused CEUS following CE-MDCT or B-mode ultrasonography may be beneficial for identifying potentially significant hypoperfused lesions. © 2013 Veterinary Radiology & Ultrasound.

  18. Contrast-enhanced flair imaging in the evaluation of infectious leptomeningeal diseases

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, Hemant [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore) and Department of Diagnostic Imaging, Hospital for Sick Children, Toronto (Canada)]. E-mail: parurad@hotmail.com; Sitoh, Y.-Y. [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore); Anand, Pooja [Department of Neurology, National Neuroscience Institute, 11 Jalan Tan Tock Seng (Singapore); Chua, Violet [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore); Hui, Francis [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore)

    2006-04-15

    Purpose: The purpose of our study was to compare contrast-enhanced fluid-attenuated inversion recovery (FLAIR) images with contrast-enhanced T1 weighted images for infectious leptomeningitis. Materials and methods: We studied twenty-four patients with a clinical suspicion of infectious meningitis with unenhanced FLAIR, contrast-enhanced T1 weighted and contrast-enhanced FLAIR MR sequences. Twelve patients had cytologic and biochemical diagnosis of meningitis on cerebrospinal fluid (CSF) examination obtained 48 h before or after the MR study. Sequences were considered positive if abnormal signal was seen in the subarachnoid space (cistern or sulci) or along pial surface. Results: Twenty-seven examinations in 24 patients were performed. Of the 12 patients (thirteen studies) in whom cytology was positive, unenhanced FLAIR images were positive in six cases (sensitivity 46%), contrast-enhanced FLAIR images were positive in 11 (sensitivity 85%), and contrast-enhanced T1 weighted MR images were positive in 11 patients (sensitivity 85%). Of the 12 patients (14 studies) in whom cerebrospinal fluid study was negative, unenhanced FLAIR images were negative in 13, contrast-enhanced FLAIR images were negative in 11, and contrast-enhanced T1 weighted MR images were negative in eight. Thus, the specificity of unenhanced FLAIR, contrast-enhanced FLAIR and contrast-enhanced T1 weighted images was 93, 79 and 57%, respectively. Conclusion: Our results suggest that post-contrast FLAIR images have similar sensitivity but a higher specificity compared to contrast-enhanced T1 weighted images for detection of leptomeningeal enhancement. It can be a useful adjunct to post-contrast T1 weighted images in evaluation of infectious leptomeningitis.

  19. Dynamic contrast-enhanced MR imaging of endometrial cancer. Optimizing the imaging delay for tumour-myometrium contrast

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Bin [Chung-Ang University Hospital, Chung-Ang University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Moon, Min Hoan; Sung, Chang Kyu [Seoul National University College of Medicine, 41, Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Oh, Sohee [Seoul National University College of Medicine, 41, Department of Biostatistics, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Lee, Young Ho [Kwandong University College of Medicine, Department of Radiology, Cheil General Hospital and Women' s Healthcare Center, Seoul (Korea, Republic of)

    2014-11-15

    To investigate the optimal imaging delay time of dynamic contrast-enhanced magnetic resonance (MR) imaging in women with endometrial cancer. This prospective single-institution study was approved by the institutional review board, and informed consent was obtained from the participants. Thirty-five women (mean age, 54 years; age range, 29-66 years) underwent dynamic contrast-enhanced MR imaging with a temporal resolution of 25-40 seconds. The signal intensity difference ratios between the myometrium and endometrial cancer were analyzed to investigate the optimal imaging delay time using single change-point analysis. The optimal imaging delay time for appropriate tumour-myometrium contrast ranged from 31.7 to 268.1 seconds. The median optimal imaging delay time was 91.3 seconds, with an interquartile range of 46.2 to 119.5 seconds. The median signal intensity difference ratios between the myometrium and endometrial cancer were 0.03, with an interquartile range of -0.01 to 0.06, on the pre-contrast MR imaging and 0.20, with an interquartile range of 0.15 to 0.25, on the post-contrast MR imaging. An imaging delay of approximately 90 seconds after initiating contrast material injection may be optimal for obtaining appropriate tumour-myometrium contrast in women with endometrial cancer. (orig.)

  20. Use of contrast-enhanced ultrasonography to characterize adrenal gland tumors in dogs.

    Science.gov (United States)

    Pey, Pascaline; Rossi, Federica; Vignoli, Massimo; Duchateau, Luc; Marescaux, Laurent; Saunders, Jimmy H

    2014-10-01

    To describe the contrast-enhanced ultrasonographic characteristics and vascular patterns of adrenal gland tumors in dogs and determine whether those features are indicative of malignancy or histologic type of tumor. 14 dogs with 16 adrenal gland lesions (10 carcinomas [8 dogs], 3 adenomas [3 dogs], and 3 pheochromocytomas [3 dogs]). Unsedated dogs with adrenal gland lesions underwent B-mode ultrasonography and contrast-enhanced ultrasonography ≤ 48 hours before adrenalectomy; contrast-enhanced ultrasonographic examinations were video-recorded. Macroscopic evaluation of the adrenal gland lesions and histologic examination of removed adrenal gland tissues were subsequently performed. Surgical and histopathologic findings and the ultrasonographic and contrast-enhanced ultrasonographic characteristics were recorded for the various tumor types. Time-intensity curves were generated from the contrast-enhanced ultrasonographic recordings and used to calculate regional blood volume (value proportional to area under the curve) and mean transit time (time the lesion began to enhance to the half-peak intensity). In adrenal gland carcinomas, tortuous feeding vessels were noticeable during the arterial and venous phases of contrast enhancement. Heterogeneity of contrast enhancement was evident only in malignant tumors. Compared with adenomas, adrenal gland carcinomas and pheochromocytomas had significantly less regional blood volume. Mean transit times were significantly shorter in adrenal gland carcinomas and pheochromocytomas than in adenomas. For dogs, evaluation of the vascular pattern and contrast-enhancement characteristics of adrenal gland tumors by means of contrast-enhanced ultrasonography may be useful in assessment of malignancy and tumor type.

  1. Prognostic significance of contrast-enhanced CT attenuation value in extrahepatic cholangiocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Asayama, Yoshiki [Kyushu University, Department of Advanced Imaging and Interventional Radiology, Graduate School of Medical Sciences, Fukuoka (Japan); Nishie, Akihiro; Ishigami, Kousei; Ushijima, Yasuhiro; Takayama, Yukihisa; Okamoto, Daisuke; Fujita, Nobuhiro; Honda, Hiroshi [Kyushu University, Departments of Clinical Radiology, Fukuoka (Japan); Ohtsuka, Takao [Kyushu University, Departments of Surgery and Oncology, Fukuoka (Japan); Yoshizumi, Tomoharu [Kyushu University, Departments of Surgery and Sciences, Fukuoka (Japan); Aishima, Shinichi [Saga University, Pathology and Microbiology, Faculty of Medicine, Saga (Japan); Kyushu University, Departments of Anatomic Pathology, Graduate School of Medical Sciences, Fukuoka (Japan); Oda, Yoshinao [Kyushu University, Departments of Anatomic Pathology, Graduate School of Medical Sciences, Fukuoka (Japan)

    2017-06-15

    To determine whether washout characteristics of dynamic contrast-enhanced computed tomography (CT) could predict survival in patients with extrahepatic cholangiocarcinoma (EHC). This study collected 46 resected cases. All cases were examined by dynamic contrast study on multidetector-row CT. Region-of-interest measurements were obtained at the non-enhanced, portal venous phase and delayed phase in the tumour and were used to calculate the washout ratio as follows: [(attenuation value at portal venous phase CT - attenuation value at delayed enhanced CT)/(attenuation value at portal venous phase CT - attenuation value at unenhanced CT)] x 100. On the basis of the median washout ratio, we classified the cases into two groups, a high-washout group and low-washout group. Associations between overall survival and various factors including washout rates were analysed. The median washout ratio was 29.4 %. Univariate analysis revealed that a lower washout ratio, venous invasion, lymphatic permeation and lymph node metastasis were associated with shorter survival. Multivariate analysis identified the lower washout ratio as an independent prognostic factor (hazard ratio, 3.768; p value, 0.027). The washout ratio obtained from the contrast-enhanced CT may be a useful imaging biomarker for the prediction of survival of patients with EHC. (orig.)

  2. Ordered k-space acquisition in contrast enhanced magnetic resonance angiography (CE-MRA)

    Science.gov (United States)

    Wu, B.; Maclaren, J. R.; Millane, R. P.; Watts, R.; Bones, P. J.

    2008-03-01

    A new way of performing contrast enhanced magnetic resonance angiography (CE-MRA) is presented, in which the entire k-space is decomposed into interlaced subsets that are acquired sequentially. Based on a new parallel imaging technique, Generalized Unaliasing Incorporating object Support constraint and sensitivity Encoding (GUISE), reconstructions can be made using different subsets of k-space to reveal the level of contrast agent in the corresponding data acquisition time period. A proof-of-concept study using a custom made phantom was carried out to examine the utility of the new method. A quantity of contrast agent (copper sulfate solution) was injected into water flowing within a tube while data was acquired using an 8-coil receiver and the modified MRI sequence. A sequence of images was successfully reconstructed at high temporal resolution. This eliminated the need to precisely synchronize data acquisition with contrast arrival. Furthermore, subtraction of a pre-contrast data set prior to reconstruction, which eliminates the need for recovering the static background signal, has proven to be an effective way to improve the SNR and allow a higher temporal resolution to be achieved in recovering the dynamic signal containing contrast level change. Acceptably good reconstruction results were obtained at a temporal resolution equivalent to a 16-fold speed up compared to the time taken to fully sample k-space.

  3. MRT Letter: Contrast-Enhanced Computed Tomographic Imaging of Soft Callus Formation in Fracture Healing

    Science.gov (United States)

    Hayward, Lauren Nicole Miller; De Bakker, Chantal Marie-Jeanne; Lusic, Hrvoje; Gerstenfeld, Louis Charles; Grinstaff, Mark W.; Morgan, Elise Feng-I

    2012-01-01

    Formation of a cartilaginous soft callus at the site of a bone fracture is a pivotal stage in the healing process. Noninvasive, or even nondestructive, imaging of soft callus formation can be an important tool in experimental and pre-clinical studies of fracture repair. However, the low X-ray attenuation of cartilage renders the soft callus nearly invisible in radiographs. This study utilized a recently developed, cationic, iodinated contrast agent in conjunction with micro-computed tomography to identify cartilage in fracture calluses in the femora of C57BL/6J and C3H/HeJ mice. Fracture calluses were scanned beforeand after incubation in the contrast agent. The set of pre-incubation images was registered against and then subtracted from the set of post-incubation images, resulting in a three-dimensional map of the locations of cartilage in the callus, as labeled by the contrast agent. This map was then compared to histology from a previous study. The results showed that the locations where the contrast agent collected in relatively high concentrationswere similar to those of the cartilage. The contrast agent also identified a significant difference between the two strains of mice in the percentage of the callus occupied by cartilage, indicating that this method of contrast-enhanced computed tomography may be an effective technique for nondestructive, early evaluation of fracture healing. PMID:22038692

  4. MRT letter: Contrast-enhanced computed tomographic imaging of soft callus formation in fracture healing.

    Science.gov (United States)

    Hayward, Lauren Nicole Miller; de Bakker, Chantal Marie-Jeanne; Lusic, Hrvoje; Gerstenfeld, Louis Charles; Grinstaff, Mark W; Morgan, Elise Feng-I

    2012-01-01

    Formation of a cartilaginous soft callus at the site of a bone fracture is a pivotal stage in the healing process. Noninvasive, or even nondestructive, imaging of soft callus formation can be an important tool in experimental and pre-clinical studies of fracture repair. However, the low X-ray attenuation of cartilage renders the soft callus nearly invisible in radiographs. This study utilized a recently developed, cationic, iodinated contrast agent in conjunction with micro-computed tomography to identify cartilage in fracture calluses in the femora of C57BL/6J and C3H/HeJ mice. Fracture calluses were scanned before and after incubation in the contrast agent. The set of pre-incubation images was registered against and then subtracted from the set of post-incubation images, resulting in a three-dimensional map of the locations of cartilage in the callus, as labeled by the contrast agent. This map was then compared to histology from a previous study. The results showed that the locations where the contrast agent collected in relatively high concentrations were similar to those of the cartilage. The contrast agent also identified a significant difference between the two strains of mice in the percentage of the callus occupied by cartilage, indicating that this method of contrast-enhanced computed tomography may be an effective technique for nondestructive, early evaluation of fracture healing. Copyright © 2011 Wiley Periodicals, Inc.

  5. Asymptotic expansions for high-contrast linear elasticity

    KAUST Repository

    Poveda, Leonardo A.

    2015-03-01

    We study linear elasticity problems with high contrast in the coefficients using asymptotic limits recently introduced. We derive an asymptotic expansion to solve heterogeneous elasticity problems in terms of the contrast in the coefficients. We study the convergence of the expansion in the H1 norm. © 2015 Elsevier B.V.

  6. Method of Improved Fuzzy Contrast Combined Adaptive Threshold in NSCT for Medical Image Enhancement

    Directory of Open Access Journals (Sweden)

    Fei Zhou

    2017-01-01

    Full Text Available Noises and artifacts are introduced to medical images due to acquisition techniques and systems. This interference leads to low contrast and distortion in images, which not only impacts the effectiveness of the medical image but also seriously affects the clinical diagnoses. This paper proposes an algorithm for medical image enhancement based on the nonsubsampled contourlet transform (NSCT, which combines adaptive threshold and an improved fuzzy set. First, the original image is decomposed into the NSCT domain with a low-frequency subband and several high-frequency subbands. Then, a linear transformation is adopted for the coefficients of the low-frequency component. An adaptive threshold method is used for the removal of high-frequency image noise. Finally, the improved fuzzy set is used to enhance the global contrast and the Laplace operator is used to enhance the details of the medical images. Experiments and simulation results show that the proposed method is superior to existing methods of image noise removal, improves the contrast of the image significantly, and obtains a better visual effect.

  7. Method of Improved Fuzzy Contrast Combined Adaptive Threshold in NSCT for Medical Image Enhancement.

    Science.gov (United States)

    Zhou, Fei; Jia, ZhenHong; Yang, Jie; Kasabov, Nikola

    2017-01-01

    Noises and artifacts are introduced to medical images due to acquisition techniques and systems. This interference leads to low contrast and distortion in images, which not only impacts the effectiveness of the medical image but also seriously affects the clinical diagnoses. This paper proposes an algorithm for medical image enhancement based on the nonsubsampled contourlet transform (NSCT), which combines adaptive threshold and an improved fuzzy set. First, the original image is decomposed into the NSCT domain with a low-frequency subband and several high-frequency subbands. Then, a linear transformation is adopted for the coefficients of the low-frequency component. An adaptive threshold method is used for the removal of high-frequency image noise. Finally, the improved fuzzy set is used to enhance the global contrast and the Laplace operator is used to enhance the details of the medical images. Experiments and simulation results show that the proposed method is superior to existing methods of image noise removal, improves the contrast of the image significantly, and obtains a better visual effect.

  8. Contrast-enhanced ultrasonography depicts small tumor vessels for the evaluation of pancreatic tumors

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Yuko [Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558 (Japan); Kawamoto, Hirofumi [Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558 (Japan)]. E-mail: h-kawamo@md.okayama-u.ac.jp; Takaki, Akinobu [Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558 (Japan); Ishida, Etsuji [Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558 (Japan); Ogawa, Tsuneyoshi [Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558 (Japan); Kuwaki, Kenji [Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558 (Japan); Kobayashi, Yoshiyuki [Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558 (Japan); Sakaguchi, Kohsaku [Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558 (Japan); Shiratori, Yasushi [Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558 (Japan)

    2007-01-15

    Objective: The aim of this study is to evaluate the efficacy of contrast-enhanced ultrasonography for the diagnosis of pancreatic tumors. Materials and methods: Contrast-enhanced ultrasonography with Levovist was performed on 62 consecutive patients (53 with pancreatic cancer, 4 with islet cell tumor, 3 with inflammatory pancreatic tumor, and 2 with metastatic tumor). The vascular and perfusion image phases of the tumors were evaluated and compared with the findings of contrast-enhanced computed tomography. Results: Contrast-enhanced ultrasonography showed tumor vessels around and/or in the tumor at the vascular image phase in 79% of pancreatic cancer patients (42/53). At the perfusion image phase, 96% of pancreatic cancers (51/53) were classified as hypo-enhancement type. However, tiny spotty or irregular heterogeneous enhanced lesions were found in 84% of hypo-enhanced pancreatic cancer patients (43/51). The presence of small vessels at the vascular image phase was closely correlated with the presence of these intratumor regional enhanced lesions at the perfusion image phase ({kappa} coefficient = 0.42). The sensitivity of contrast-enhanced ultrasonography (100%) for pancreatic cancer was superior to that of contrast-enhanced computed tomography (91%), but no significant difference was observed between the two (McNemar test: p = 0.063). Conclusion: Contrast-enhanced ultrasonography with Levovist successfully visualizes fine vessels and enhancement in pancreatic tumors, and is useful for evaluating pancreatic tumors.

  9. Gray-scale contrast-enhanced utrasonography in detecting sentinel lymph nodes: An animal study

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yuexiang, E-mail: wangyuexiang1999@sina.co [Department of Ultrasound, Chinese People' s Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853 (China); Cheng Zhigang, E-mail: qlczg@sina.co [Department of Ultrasound, Chinese People' s Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853 (China); Li Junlai, E-mail: junlai555@sina.co [Department of Ultrasound, Chinese People' s Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853 (China); Tang Jie, E-mail: txiner@vip.sina.co [Department of Ultrasound, Chinese People' s Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853 (China)

    2010-06-15

    Objective: To investigate the usefulness of gray-scale contrast-enhanced ultrasonography for detecting sentinel lymph nodes. Methods: Contrast-enhanced ultrasonography was performed in five normal dogs (four female and one male) after subcutaneous administration of a sonographic contrast agent (Sonovue, Bracco, Milan, Italy). Four distinct regions in each animal were examined. After contrast-enhanced ultrasonography, 0.8 ml of blue dye was injected into the same location as Sonovue and the sentinel lymph nodes were detected by surgical dissection. The findings of contrast-enhanced ultrasonography were compared with those of the blue dye. Results: Twenty-one sentinel lymph nodes were detected by contrast-enhanced ultrasonography while 23 were identified by blue dye with surgical dissection. Compared with the blue dye, the detection rate of enhanced ultrasonography for the sentinel lymph nodes is 91.3% (21/23). Two patterns of enhancement in the sentinel lymph nodes were observed: complete enhancement (5 sentinel lymph nodes) and partial enhancement (16 sentinel lymph nodes). The lymphatic channels were demonstrated as hyperechoic linear structures leading from the injection site and could be readily followed to their sentinel lymph nodes. Histopathologic examination showed proliferation of lymphatic follicles or lymphatic sinus in partial enhanced sentinel lymph nodes while normal lymphatic tissue was demonstrated in completely enhanced sentinel lymph nodes. Conclusions: Sonovue combined with gray-scale contrast-enhanced ultrasonography may provide a feasible method for detecting sentinel lymph nodes.

  10. Fusion imaging of contrast-enhanced ultrasound and contrast-enhanced CT or MRI before radiofrequency ablation for liver cancers.

    Science.gov (United States)

    Bo, Xiao-Wan; Xu, Hui-Xiong; Wang, Dan; Guo, Le-Hang; Sun, Li-Ping; Li, Xiao-Long; Zhao, Chong-Ke; He, Ya-Ping; Liu, Bo-Ji; Li, Dan-Dan; Zhang, Kun

    2016-11-01

    To investigate the usefulness of fusion imaging of contrast-enhanced ultrasound (CEUS) and CECT/CEMRI before percutaneous ultrasound-guided radiofrequency ablation (RFA) for liver cancers. 45 consecutive patients with 70 liver lesions were included between March 2013 and October 2015, and all the lesions were identified on CEMRI/CECT prior to inclusion in the study. Planning ultrasound for percutaneous RFA was performed using conventional ultrasound, ultrasound-CECT/CEMRI and CEUS and CECT/CEMRI fusion imaging during the same session. The numbers of the conspicuous lesions on ultrasound and fusion imaging were recorded. RFA was performed according to the results of fusion imaging. Complete response (CR) rate was calculated and the complications were recorded. On conventional ultrasound, 25 (35.7%) of the 70 lesions were conspicuous, whereas 45 (64.3%) were inconspicuous. Ultrasound-CECT/CEMRI fusion imaging detected additional 24 lesions thus increased the number of the conspicuous lesions to 49 (70.0%) (70.0% vs 35.7%; p ultrasound). With the use of CEUS and CECT/CEMRI fusion imaging, the number of the conspicuous lesions further increased to 67 (95.7%, 67/70) (95.7% vs 70.0%, 95.7% vs 35.7%; both p ultrasound and ultrasound-CECT/CEMRI fusion imaging, respectively). With the assistance of CEUS and CECT/CEMRI fusion imaging, the confidence level of the operator for performing RFA improved significantly with regard to visualization of the target lesions (p = 0.001). The CR rate for RFA was 97.0% (64/66) in accordance to the CECT/CEMRI results 1 month later. No procedure-related deaths and major complications occurred during and after RFA. Fusion of CEUS and CECT/CEMRI improves the visualization of those inconspicuous lesions on conventional ultrasound. It also facilitates improvement in the RFA operators' confidence and CR of RFA. Advances in knowledge: CEUS and CECT/CEMRI fusion imaging is better than both conventional ultrasound and ultrasound

  11. Staging accuracy of pancreatic cancer: Comparison between non-contrast-enhanced and contrast-enhanced PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Yoneyama, Tomohiro [Department of Radiology, Yokohama City University, Graduate School of Medicine, Yokohama (Japan); Tateishi, Ukihide, E-mail: utateish@yokohama-cu.ac.jp [Department of Radiology, Yokohama City University, Graduate School of Medicine, Yokohama (Japan); Endo, Itaru [Department of Surgery, Yokohama City University, Graduate School of Medicine, Yokohama (Japan); Inoue, Tomio [Department of Radiology, Yokohama City University, Graduate School of Medicine, Yokohama (Japan)

    2014-10-15

    Purpose: Our aim was to clarify the diagnostic impact of contrast-enhanced (CE) {sup 18}F-fluorodeoxyglucose (FDG)–positron emission tomography (PET)/computed tomography (CT) for staging of pancreatic cancer compared to non-CE PET/CT. Method and materials: Between April 2006 and November 2009, a total of 95 patients (age range, 36–83 years [mean age, 67]) with primary pancreatic cancer underwent {sup 18}F-FDG PET/CT examinations. Diagnostic accuracy was compared between non-CE PET/CT and CE PET/CT. Images were analyzed visually and quantitatively by two blinded reviewers. Reference standard was histological examination in 48 patients (51%) and/or confirmation of an obvious progression in number and/or size of the lesions on follow-up CT examinations in 47 patients (49%). Results: For T-staging, invasion of duodenum (n = 20, 21%), mesentery (n = 12, 13%), and retroperitoneum (n = 13, 14%) was correctly diagnosed by both modalities. The ROC analyses revealed that the Az values of celiac artery (CA), common hepatic artery (CHA), splenic artery (SV), and superior mesenteric vein (SMV) invasion were significantly higher in the CE PET/CT group for both readers. Nodal metastasis was correctly diagnosed by CE PET/CT in 38 patients (88%) and by non-CE PET/CT in 45 patients (87%). Diagnostic accuracies of nodal metastasis in two modalities were similar. Using CE PET/CT, distant metastasis, scalene node metastasis, and peritoneal dissemination were correctly assigned in 39 patients (91%), while interpretation based on non-CE PET/CT revealed distant metastasis, scalene node metastasis, and peritoneal dissemination in 42 patients (81%). Diagnostic accuracy of distant metastasis, scalene node metastasis, and peritoneal dissemination with CE PET/CT was significantly higher than that of non-CE PET/CT (p < 0.05). Conclusion: CE PET/CT allows a more precise assessment of distant metastasis, scalene node metastasis, and peritoneal dissemination in patients with pancreatic cancer.

  12. Contrast-enhanced magnetic resonance angiography for preoperative imaging in DIEP flap breast reconstruction.

    Science.gov (United States)

    Schaverien, Mark V; Ludman, Catherine N; Neil-Dwyer, Jason; Perks, Graeme B; Akhtar, Nadeem; Rodrigues, Jeremy N; Benetatos, Konstantinos; Raurell, Anna; Rasheed, Tuabin; McCulley, Stephen J

    2011-07-01

    Contrast-enhanced magnetic resonance angiography has been shown to be very accurate for identifying the perforator size, location, and intramuscular course, and the associated venous system, without exposing the patient to ionizing radiation. This study reports the authors' experience using this imaging modality in a large patient series. A retrospective review of patients who had undergone preoperative contrast-enhanced magnetic resonance angiography followed by free abdominal flap breast reconstruction was conducted. The results of imaging were compared with intraoperative findings, and surgical outcomes were compared with scan data. The results were compared with control data in patients who did not undergo presurgical imaging. One hundred thirty-two patients underwent contrast-enhanced magnetic resonance angiography presurgical imaging, and the results were compared with 84 controls. The imaging was found to be accurate for evaluating the perforator anatomy for free abdominal flap planning, with a high concordance between imaging and intraoperative findings. Without presurgical angiography, the ratio of deep inferior epigastric perforator (DIEP) flap-to-free transverse rectus abdominis musculocutaneous flap harvest was 0.9:1; with presurgical imaging, the ratio was 1.6:1 (p angiography, there was a mean reduction in operating time of 26 minutes for unilateral DIEP flap harvest and 40 minutes for bilateral harvest, although these values were not significant. There was a significant reduction in the partial flap failure rate with preoperative imaging. Presurgical imaging using contrast-enhanced magnetic resonance angiography demonstrates a high concordance with intraoperative findings. In this series, the percentage of flaps that were raised as DIEP flaps was significantly increased in patients who underwent preoperative imaging, and the partial flap failure rate was significantly reduced. : Therapeutic, III.(Figure is included in full-text article.).

  13. Image contrast enhancement using adjacent-blocks-based modification for local histogram equalization

    Science.gov (United States)

    Wang, Yang; Pan, Zhibin

    2017-11-01

    Infrared images usually have some non-ideal characteristics such as weak target-to-background contrast and strong noise. Because of these characteristics, it is necessary to apply the contrast enhancement algorithm to improve the visual quality of infrared images. Histogram equalization (HE) algorithm is a widely used contrast enhancement algorithm due to its effectiveness and simple implementation. But a drawback of HE algorithm is that the local contrast of an image cannot be equally enhanced. Local histogram equalization algorithms are proved to be the effective techniques for local image contrast enhancement. However, over-enhancement of noise and artifacts can be easily found in the local histogram equalization enhanced images. In this paper, a new contrast enhancement technique based on local histogram equalization algorithm is proposed to overcome the drawbacks mentioned above. The input images are segmented into three kinds of overlapped sub-blocks using the gradients of them. To overcome the over-enhancement effect, the histograms of these sub-blocks are then modified by adjacent sub-blocks. We pay more attention to improve the contrast of detail information while the brightness of the flat region in these sub-blocks is well preserved. It will be shown that the proposed algorithm outperforms other related algorithms by enhancing the local contrast without introducing over-enhancement effects and additional noise.

  14. Temporal adaptation enhances efficient contrast gain control on natural images.

    Directory of Open Access Journals (Sweden)

    Fabian Sinz

    Full Text Available Divisive normalization in primary visual cortex has been linked to adaptation to natural image statistics in accordance to Barlow's redundancy reduction hypothesis. Using recent advances in natural image modeling, we show that the previously studied static model of divisive normalization is rather inefficient in reducing local contrast correlations, but that a simple temporal contrast adaptation mechanism of the half-saturation constant can substantially increase its efficiency. Our findings reveal the experimentally observed temporal dynamics of divisive normalization to be critical for redundancy reduction.

  15. Dual-Frequency Piezoelectric Transducers for Contrast Enhanced Ultrasound Imaging

    Directory of Open Access Journals (Sweden)

    K. Heath Martin

    2014-11-01

    Full Text Available For many years, ultrasound has provided clinicians with an affordable and effective imaging tool for applications ranging from cardiology to obstetrics. Development of microbubble contrast agents over the past several decades has enabled ultrasound to distinguish between blood flow and surrounding tissue. Current clinical practices using microbubble contrast agents rely heavily on user training to evaluate degree of localized perfusion. Advances in separating the signals produced from contrast agents versus surrounding tissue backscatter provide unique opportunities for specialized sensors designed to image microbubbles with higher signal to noise and resolution than previously possible. In this review article, we describe the background principles and recent developments of ultrasound transducer technology for receiving signals produced by contrast agents while rejecting signals arising from soft tissue. This approach relies on transmitting at a low-frequency and receiving microbubble harmonic signals at frequencies many times higher than the transmitted frequency. Design and fabrication of dual-frequency transducers and the extension of recent developments in transducer technology for dual-frequency harmonic imaging are discussed.

  16. Contrast-enhanced ultrasound of histologically proven hepatic epithelioid hemangioendothelioma

    DEFF Research Database (Denmark)

    Dong, Yi; Wang, Wen-Ping; Cantisani, Vito

    2016-01-01

    %) in the arterial phase and hypoenhancement (25/25, 100%) in the portal venous and late phases (PVLP), a sign of malignancy. Eighteen patients showed central unenhanced areas (18/25, 72%); in seven patients (7/25, 28%), more lesions were detected in the PVLP. In contrast, all patients with hemangioma and focal...

  17. Contrast enhanced ultrasound in CT-undetermined focal liver lesions

    DEFF Research Database (Denmark)

    Sandrose, Sebastian; Karstrup, S.; Gerke, Oke

    2016-01-01

    . A total of 78 patients were evaluated: 41 men and 37 women, mean age 61.8 years; age range 30–91 years. All patients were examined with GE LOGIQ 9E ultrasound scanners with contrast-specific software, and SonoVue intravenous bolus. The standard of reference was composite consisting of: percutaneous biopsy...

  18. High Contrast Vacuum Nuller Testbed (VNT) Contrast, Performance and Null Control

    Science.gov (United States)

    Lyon, Richard G.; Clampin, Mark; Petrone, Peter; Mallik, Udayan; Madison, Timothy; Bolcar, Matthew R.

    2012-01-01

    Herein we report on our Visible Nulling Coronagraph high-contrast result of 109 contrast averaged over a focal planeregion extending from 14 D with the Vacuum Nuller Testbed (VNT) in a vibration isolated vacuum chamber. TheVNC is a hybrid interferometriccoronagraphic approach for exoplanet science. It operates with high Lyot stopefficiency for filled, segmented and sparse or diluted-aperture telescopes, thereby spanning the range of potential futureNASA flight telescopes. NASAGoddard Space Flight Center (GSFC) has a well-established effort to develop the VNCand its technologies, and has developed an incremental sequence of VNC testbeds to advance this approach and itsenabling technologies. These testbeds have enabled advancement of high-contrast, visible light, nulling interferometry tounprecedented levels. The VNC is based on a modified Mach-Zehnder nulling interferometer, with a W configurationto accommodate a hex-packed MEMS based deformable mirror, a coherent fiber bundle and achromatic phase shifters.We give an overview of the VNT and discuss the high-contrast laboratory results, the optical configuration, criticaltechnologies and null sensing and control.

  19. Evaluation of tumor angiogenesis of breast carcinoma using contrast-enhanced digital mammography.

    Science.gov (United States)

    Dromain, Clarisse; Balleyguier, Corrine; Muller, Serge; Mathieu, Marie-Christine; Rochard, France; Opolon, Paule; Sigal, Robert

    2006-11-01

    The purpose of this article is to assess the accuracy of contrast-enhanced digital mammography in the detection of breast carcinoma and to correlate the findings on the images with those of histologic analysis using microvessel quantification. Twenty patients with a suspicious breast abnormality underwent contrast-enhanced digital mammography using a full-field digital mammography unit that was modified to detect iodinated enhancement. For each patient, a total of six contrast-enhanced craniocaudal views were acquired from 30 seconds to 7 minutes after the injection of a bolus of 100 mL of an iodinated contrast agent. Image processing included a logarithmic subtraction and the analysis of enhancement kinetic curves. Contrast-enhanced digital mammography findings were compared with histologic analysis of surgical specimens, including intratumoral microvessel density quantification evaluated on CD34-immunostained histologic sections obtained from all patients. An area of enhancement was depicted on contrast-enhanced digital mammograms in 16 of the 20 histologically proven breast carcinomas. Excellent correlation was seen between the size of enhancement and the histologic size of tumors, which ranged from 9 to 22 mm. Early enhancement with washout was observed in four cases, early enhancement followed by a plateau in four cases, gradual enhancement in seven cases, and unexpected decrease of enhancement in one case. Intratumoral microvessel density ranged from 11.7 to 216.6 microvessels per square millimeter. A poor correlation was found between data measured on contrast-enhanced digital mammography and intratumoral microvessel density measured on CD34-immunostained histologic sections. Contrast-enhanced digital mammography is able to depict angiogenesis in breast carcinoma. Breast compression and projective images acquisition alter the quantitative assessment of enhancement parameters.

  20. Modified Global and Modified Linear Contrast Stretching Algorithms: New Colour Contrast Enhancement Techniques for Microscopic Analysis of Malaria Slide Images

    Science.gov (United States)

    Abdul-Nasir, Aimi Salihah; Mashor, Mohd Yusoff; Mohamed, Zeehaida

    2012-01-01

    Malaria is one of the serious global health problem, causing widespread sufferings and deaths in various parts of the world. With the large number of cases diagnosed over the year, early detection and accurate diagnosis which facilitates prompt treatment is an essential requirement to control malaria. For centuries now, manual microscopic examination of blood slide remains the gold standard for malaria diagnosis. However, low contrast of the malaria and variable smears quality are some factors that may influence the accuracy of interpretation by microbiologists. In order to reduce this problem, this paper aims to investigate the performance of the proposed contrast enhancement techniques namely, modified global and modified linear contrast stretching as well as the conventional global and linear contrast stretching that have been applied on malaria images of P. vivax species. The results show that the proposed modified global and modified linear contrast stretching techniques have successfully increased the contrast of the parasites and the infected red blood cells compared to the conventional global and linear contrast stretching. Hence, the resultant images would become useful to microbiologists for identification of various stages and species of malaria. PMID:23082089

  1. Tomosynthesis and contrast-enhanced digital mammography: recent advances in digital mammography.

    Science.gov (United States)

    Diekmann, Felix; Bick, Ulrich

    2007-12-01

    Digital mammography is more and more replacing conventional mammography. Initial concerns about an inferior image quality of digital mammography have been largely overcome and recent studies even show digital mammography to be superior in women with dense breasts, while at the same time reducing radiation exposure. Nevertheless, an important limitation of digital mammography remains: namely, the fact that summation may obscure lesions in dense breast tissue. However, digital mammography offers the option of so-called advanced applications, and two of these, contrast-enhanced mammography and tomosynthesis, are promising candidates for improving the detection of breast lesions otherwise obscured by the summation of dense tissue. Two techniques of contrast-enhanced mammography are available: temporal subtraction of images acquired before and after contrast administration and the so-called dual-energy technique, which means that pairs of low/high-energy images acquired after contrast administration are subtracted. Tomosynthesis on the other hand provides three-dimensional information on the breast. The images are acquired with different angulations of the X-ray tube while the object or detector is static. Various reconstruction algorithms can then be applied to the set of typically nine to 28 source images to reconstruct 1-mm slices with a reduced risk of obscuring pathology. Combinations of both advanced applications have only been investigated in individual experimental studies; more advanced software algorithms and CAD systems are still in their infancy and have only undergone preliminary clinical evaluation.

  2. Dual-Energy CT in Hemorrhagic Progression of Cerebral Contusion: Overestimation of Hematoma Volumes on Standard 120-kV Images and Rectification with Virtual High-Energy Monochromatic Images after Contrast-Enhanced Whole-Body Imaging.

    Science.gov (United States)

    Bodanapally, U K; Shanmuganathan, K; Issa, G; Dreizin, D; Guang, L; Sudini, K; Fleiter, T R

    2018-02-08

    In patients with hemorrhagic contusions, hematoma volumes are overestimated on follow-up standard 120-kV images obtained after contrast-enhanced whole-body CT. We aimed to retrospectively determine hemorrhagic progression of contusion rates on 120-kV and 190-keV images derived from dual-energy CT and the magnitude of hematoma volume overestimation. We retrospectively analyzed admission and follow-up CT studies in 40 patients with hemorrhagic contusions. After annotating the contusions, we measured volumes from admission and follow-up 120-kV and 190-keV images using semiautomated 3D segmentation. Bland-Altman analysis was used for hematoma volume comparison. On 120-kV images, hemorrhagic progression of contusions was detected in 24 of the 40 patients, while only 17 patients had hemorrhagic progression of contusions on 190-keV images ( P = .008). Hematoma volumes were systematically overestimated on follow-up 120-kV images (9.68 versus 8 mm 3 ; mean difference, 1.68 mm 3 ; standard error, 0.37; P images. There was no significant difference in volumes between admission 120-kV and 190-keV images. Mean and median percentages of overestimation were 29% (95% CI, 18-39) and 22% (quartile 3 - quartile 1 = 36.8), respectively. The 120-kV images, which are comparable with single-energy CT images, significantly overestimated the hematoma volumes, hence the rate of hemorrhagic progression of contusions, after contrast-enhanced whole-body CT. Hence, follow-up of hemorrhagic contusions should be performed on dual-energy CT, and 190-keV images should be used for the assessment of hematoma volumes. © 2018 by American Journal of Neuroradiology.

  3. A contrast-enhanced ultrasound study of benign and malignant ...

    African Journals Online (AJOL)

    enhanced ultrasound assessment in benign and malignant breast tissue, using histological examination as the reference standard. Methods. An HDI 5000 Phillips ultrasound scanner with microvascular imaging software and 2.5 ml SonoVue (Bracco ...

  4. Fe Core–Carbon Shell Nanoparticles as Advanced MRI Contrast Enhancer

    Directory of Open Access Journals (Sweden)

    Rakesh P. Chaudhary

    2017-10-01

    Full Text Available The aim of this study is to fabricate a hybrid composite of iron (Fe core–carbon (C shell nanoparticles with enhanced magnetic properties for contrast enhancement in magnetic resonance imaging (MRI. These new classes of magnetic core–shell nanoparticles are synthesized using a one-step top–down approach through the electric plasma discharge generated in the cavitation field in organic solvents by an ultrasonic horn. Transmission electron microscopy (TEM observations revealed the core–shell nanoparticles with 10–85 nm in diameter with excellent dispersibility in water without any agglomeration. TEM showed the structural confirmation of Fe nanoparticles with body centered cubic (bcc crystal structure. Magnetic multi-functional hybrid composites of Fe core–C shell nanoparticles were then evaluated as negative MRI contrast agents, displaying remarkably high transverse relaxivity (r2 of 70 mM−1·S−1 at 7 T. This simple one-step synthesis procedure is highly versatile and produces desired nanoparticles with high efficacy as MRI contrast agents and potential utility in other biomedical applications.

  5. [Application of dynamic contrast enhancement MRI and post-processing technique for diagnosis of breast cancer].

    Science.gov (United States)

    Peng, Kang-Qiang; Huang, Zi-Lin; Xie, Chuan-Miao; Chen, Lin; Ouyang, Yi; Zheng, Qing-Sheng; Zhang, Yan; He, Hao-Qiang; Wu, Pei-Hong

    2009-05-01

    Magnetic resonance imaging (MRI), an advanced non-invasive technique, is regarded as one of the potential modalities in the diagnosis of breast cancer. This study was to investigate the application of dynamic contrast enhancement MRI and 3D reconstruction images in diagnosing breast tumors. From May 2006 to September 2007, 30 patients with breast diseases were scanned with MRI in Sun Yat-sen University Cancer Center. MR plain scans, dynamic contrast enhancement scans were performed, and 3D reconstruction images were obtained. The normal breast tissue was used as control, and the maximum slope ratio was calculated. Forty-nine lesions were found in 30 patients, with an accuracy rate of 93.3%. MRI scan is an effective and specific modality for the diagnosis of breast diseases with high sensitivity and accuracy. Dynamic contrast enhancement MRI, image subtraction, time-signal intensity curve, 3D reconstruction images and the maximum slope ratio are helpful to make the correct diagnosis of breast lesions.

  6. A monte carlo comparison of three different media for contrast enhanced radiotherapy of the prostate.

    Science.gov (United States)

    Garnica-Garza, H M

    2010-06-01

    Contrast-enhanced radiotherapy makes use of a kilovoltage X-ray beam, either from a diagnostic X-ray tube or modified megavoltage linear accelerator, in conjunction with a high-Z contrast medium deposited into the target volume to enhance the absorption of radiation. In this work, using the Monte Carlo code PENELOPE and the voxelized Zubal phantom to model a prostate radiotherapy treatment, a comparison between the physical absorbed dose distributions rendered by three different enhancing agents namely bismuth, gadolinium, and iodine is performed. It is assumed that there exists a concentration of 10 mg of enhancing agent per 1 g of tissue in the target volume while in the background a concentration of 1.5 mg per 1 g of tissue is present. The X-ray beam energy spectrum was obtained by means of Monte Carlo simulation of a tungsten target upon which a 220 keV mono-energetic electron pencil beam is made to impinge, and the resultant photon beam is heavily filtrated by 0.2 cm of copper. The treatment delivery is simulated as a 3608 arc collimated to conform to the target from every direction. Cumulative dose-volume histograms and isodose curves are presented for the target as well as five organs-at-risk, namely rectal wall, bladder, femoral heads, skin, and bone marrow. It is shown that under these conditions clinically acceptable treatment plans are obtained for all three contrast agents. A 72 Gy dose to 100% of the target volume results in maximum absorbed doses to the above mentioned organs-at-risk of 65, 56, 44, 32 and 65 Gy respectively when bismuth is used as the contrast agent, but the results obtained with gadolinium follow closely.

  7. Asymptotic expansions for high-contrast elliptic equations

    KAUST Repository

    Calo, Victor M.

    2014-03-01

    In this paper, we present a high-order expansion for elliptic equations in high-contrast media. The background conductivity is taken to be one and we assume the medium contains high (or low) conductivity inclusions. We derive an asymptotic expansion with respect to the contrast and provide a procedure to compute the terms in the expansion. The computation of the expansion does not depend on the contrast which is important for simulations. The latter allows avoiding increased mesh resolution around high conductivity features. This work is partly motivated by our earlier work in [Domain decomposition preconditioners for multiscale flows in high-contrast media, Multiscale Model Simul. 8 (2010) 1461-1483] where we design efficient numerical procedures for solving high-contrast problems. These multiscale approaches require local solutions and our proposed high-order expansion can be used to approximate these local solutions inexpensively. In the case of a large-number of inclusions, the proposed analysis can help to design localization techniques for computing the terms in the expansion. In the paper, we present a rigorous analysis of the proposed high-order expansion and estimate the remainder of it. We consider both high-and low-conductivity inclusions. © 2014 World Scientific Publishing Company.

  8. Detection of bleeding in patients with major pelvic fractures: value of contrast-enhanced CT.

    Science.gov (United States)

    Cerva, D S; Mirvis, S E; Shanmuganathan, K; Kelly, I M; Pais, S O

    1996-01-01

    trauma. Contrast-enhanced CT of the pelvis, which is often performed for hemodynamically stable trauma patients, is a noninvasive technique that is highly accurate in determining the presence or absence of ongoing pelvic hemorrhage. This information can assist in initial management decisions involving patients with multisystem trauma and major pelvic fractures.

  9. Characterization of the enhancing lesions on dynamic contrast enhanced magnetic resonance imaging in patients with interstitial mammoplasty

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Yun [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kim, Sung Hun, E-mail: rad-ksh@catholic.ac.kr [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kang, Bong Joo [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kim, Hyeon Sook [Department of Radiology, St. Paul Hospital, The Catholic University of Korea (Korea, Republic of); Cha, Eun Suk [Department of Radiology, Ewha Womans University, School of Medicine, Mokdong Hospital (Korea, Republic of); Kim, Ji Youn [Department of Radiology, Yeouido St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Song, Byung Joo [Department of Surgery, Seoul St. Mary' s Hospital, The Catholic University of Korea, Seoul (Korea, Republic of)

    2013-12-01

    Purpose: The purpose of this study was to categorize the morphologic and kinetic features of enhancing lesions in breasts with interstitial mammoplasty using dynamic contrast-enhanced magnetic resonance imaging and to assess factors predictive of breast cancer. Materials and methods: We retrospectively reviewed the clinical and radiological data of 21 enhancing lesions in 19 patients with interstitial mammoplasty, who underwent breast magnetic resonance imaging and biopsy or an operation in our hospital from September 2008 to July 2012. These lesions were sorted by morphological and kinetic features and final assessment category according to the BI-RADS lexicon. Results: Nine cases were confirmed to be ductal carcinoma in situ (n = 2) and invasive ductal carcinoma (n = 7), and the remaining 12 cases were fibrocystic disease (n = 2), fibroadenoma (n = 2), fat necrosis (n = 1), foreign body granuloma (n = 3) and silicone mastitis (n = 1). Common features of malignancy included irregular shape (50.0%), spiculated margins (75.0%), heterogeneous enhancement (50.0%) and type III kinetic pattern (87.5%). The correlations of margins and kinetic curve pattern with benignity and malignancy approached statistical significance (p = 0.02, respectively). We found no correlation for shape (p = 0.33) or internal enhancement (p = 0.42) between lesion types. The malignancy rate of enhancing lesions was 42.8% (9/21). The sensitivity and specificity of dynamic contrast-enhanced magnetic resonance imaging were 100% and 16.67%, respectively. The positive predictive value, negative predictive value and accuracy of magnetic resonance imaging were 47.38%, 100% and 52.38%. Overall inter-observer agreement for the kinetic curve pattern was good (κ = 0.67). Moderate agreement was seen in describing the shape, margin, enhancement and assessing the final category (κ = 0.59, 0.46, 0.58 and 0.49, respectively). Conclusion: Dynamic contrast-enhanced magnetic resonance imaging had a high

  10. Contrast-enhanced continuous-terahertz-wave imaging based on superparamagnetic iron oxide nanoparticles for biomedical applications.

    Science.gov (United States)

    Zhang, Rui; Zhang, Liangliang; Wu, Tong; Zuo, Shasha; Wang, Ruixue; Zhang, Cunlin; Zhang, Jue; Fang, Jing

    2016-04-18

    We present a novel contrast-enhanced continuous-terahertz-wave imaging modality based on magnetic induction heating of superparamagnetic iron oxide nanoparticles (SPIOs), which yields a highly sensitive increment in the reflection terahertz (THz) signal in SPIO solution upon exposure to an alternating magnetic field. In the differential and relative refection change focal-plane images before and after alternating magnetic field exposure, a dramatic contrast is demonstrated between water with and without SPIOs. This low-cost, simple, and stable contrast-enhanced continuous-THz-wave imaging system is suitable for miniaturization and real-time imaging application.

  11. Blood Pool Agent Contrast-Enhanced MRA: Level-Set Based Artery-Vein Separation

    NARCIS (Netherlands)

    van Bemmel, C.M.; Spreeuwers, Lieuwe Jan; Verdonck, B.; Viergever, M.A.; Niessen, W.J.

    2002-01-01

    Blood pool agents (BPAs) for contrast-enhanced magnetic resonance angiography (CE-MRA) allow prolonged imaging times for higher contrast and resolution by imaging during the steady state when the contrast agent is distributed through the complete vascular system. However, simultaneous arterial and

  12. Contrast-enhanced ultrasound in non-operative management of pancreatic injury in childhood

    Energy Technology Data Exchange (ETDEWEB)

    Valentino, Massimo; Sartoni Galloni, Stefania; Rimondi, Maria Rita; Barozzi, Libero [University Hospital S. Orsola-Malpighi, Emergency Department, Bologna (Italy); Gentili, Andrea [University Hospital S. Orsola-Malpighi, Department of Anaesthesia and Intensive Care, Bologna (Italy); Lima, Mario [University Hospital S. Orsola-Malpighi, Department of Paediatrics, Bologna (Italy)

    2006-06-15

    We report a 5-year-old child with pancreatic trauma from a blunt abdominal injury that was monitored with contrast-enhanced sonography. Unenhanced US failed to demonstrate the abnormality that was recognized by CT and MRI. The injury was well demonstrated by contrast-enhanced US which was therefore used for follow-up until its healing. (orig.)

  13. Contrast-enhanced power Doppler ultrasonography of the metacarpophalangeal joints in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Szkudlarek, Marcin; Court-Payen, Michel; Strandberg, Charlotte

    2003-01-01

    The aim of this study was to examine, with dynamic contrast-enhanced MRI as the reference, if contrast-enhanced power Doppler ultrasonography (CE PDUS) of rheumatoid arthritis (RA) metacarpophalangeal (MCP) joints provides additional information for evaluation of synovial inflammation compared...

  14. An evaluation of contrast enhancement techniques for mammographic breast masses.

    Science.gov (United States)

    Singh, Sameer; Bovis, Keir

    2005-03-01

    The main aim of this paper is to propose a novel set of metrics that measure the quality of the image enhancement of mammographic images in a computer-aided detection framework aimed at automatically finding masses using machine learning techniques. Our methodology includes a novel mechanism for the combination of the metrics proposed into a single quantitative measure. We have evaluated our methodology on 200 images from the publicly available digital database for screening mammograms. We show that the quantitative measures help us select the best suited image enhancement on a per mammogram basis, which improves the quality of subsequent image segmentation much better than using the same enhancement method for all mammograms.

  15. Binocular combination of phase and contrast explained by a gain-control and gain-enhancement model

    Science.gov (United States)

    Ding, Jian; Klein, Stanley A.; Levi, Dennis M.

    2013-01-01

    We investigated suprathreshold binocular combination, measuring both the perceived phase and perceived contrast of a cyclopean sine wave. We used a paradigm adapted from Ding and Sperling (2006, 2007) to measure the perceived phase by indicating the apparent location (phase) of the dark trough in the horizontal cyclopean sine wave relative to a black horizontal reference line, and we used the same stimuli to measure perceived contrast by matching the binocular combined contrast to a standard contrast presented to one eye. We found that under normal viewing conditions (high contrast and long stimulus duration), perceived contrast is constant, independent of the interocular contrast ratio and the interocular phase difference, while the perceived phase shifts smoothly from one eye to the other eye depending on the contrast ratios. However, at low contrasts and short stimulus durations, binocular combination is more linear and contrast summation is phase-dependent. To account for phase-dependent contrast summation, we incorporated a fusion remapping mechanism into our model, using disparity energy to shift the monocular phases towards the cyclopean phase in order to align the two eyes' images through motor/sensory fusion. The Ding-Sperling model with motor/sensory fusion mechanism gives a reasonable account of the phase dependence of binocular contrast combination and can account for either the perceived phase or the perceived contrast of a cyclopean sine wave separately; however it requires different model parameters for the two. However, when fit to both phase and contrast data simultaneously, the Ding-Sperling model fails. Incorporating interocular gain enhancement into the model results in a significant improvement in fitting both phase and contrast data simultaneously, successfully accounting for both linear summation at low contrast energy and strong nonlinearity at high contrast energy. PMID:23397038

  16. Contrast-enhanced sonography for detection of secondary lymph nodes in a melanoma tumor animal model.

    Science.gov (United States)

    Liu, Ji-Bin; Merton, Daniel A; Berger, Adam C; Forsberg, Flemming; Witkiewicz, Agnieszka; Zhao, Hongjia; Eisenbrey, John R; Fox, Traci B; Goldberg, Barry B

    2014-06-01

    To investigate the use of contrast-enhanced ultrasound imaging (US) for detection of secondary lymph nodes (LNs) in a naturally occurring melanoma swine model compared to surgery and pathologic assessment. Twenty-seven Sinclair swine were studied. The perfluorobutane microbubble contrast agent Sonazoid (GE Healthcare, Oslo, Norway) was administered (1.0 mL total dose) around the melanoma, and contrast-enhanced US was used to localize contrast-enhanced sentinel lymph nodes (SLNs). Then Sonazoid (dose, 0.25-1.0 mL) was injected into the SLNs to detect contrast-enhanced efferent lymphatic channels and secondary LNs. After peritumoral injection of blue dye, a surgeon (blinded to the contrast-enhanced US results) performed a radical LN dissection. Contrast-enhanced US was used to guide removal of any enhanced secondary LNs left after radical LN dissection. Clustered conditional logistic regression analyzed the benefit of contrast-enhanced US-directed secondary LN dissection over radical LN dissection using pathologic findings as the reference standard. A total of 268 secondary LNs were resected, with 59 (22%) containing metastases. Contrast-enhanced US detected 92 secondary LNs; 248 were identified by radical LN dissection; and 68 were identified by both methods. Metastases were detected in 20% (51 of 248) and 40% (37 of 92) of the secondary LNs identified by radical LN dissection and contrast-enhanced US, respectively. Thus, secondary LNs detected by contrast-enhanced US were nearly 5 times more likely to contain metastases than secondary LNs removed by radical LN dissection (odds ratio, 4.8; P < .0001). Twenty-two of the 180 secondary LNs (12%) identified only by radical LN dissection contained metastases, whereas contrast-enhanced US identified 20 secondary LNs after the surgeon completed the radical LN dissection, of which 8 (40%) contained metastases. Secondary LNs can be detected by using contrast-enhanced US after injection of Sonazoid into SLNs. Secondary LNs

  17. Tolerance of image enhancement brightness and contrast in lateral cephalometric digital radiography for Steiner analysis

    Science.gov (United States)

    Rianti, R. A.; Priaminiarti, M.; Syahraini, S. I.

    2017-08-01

    Image enhancement brightness and contrast can be adjusted on lateral cephalometric digital radiographs to improve image quality and anatomic landmarks for measurement by Steiner analysis. To determine the limit value for adjustments of image enhancement brightness and contrast in lateral cephalometric digital radiography for Steiner analysis. Image enhancement brightness and contrast were adjusted on 100 lateral cephalometric radiography in 10-point increments (-30, -20, -10, 0, +10, +20, +30). Steiner analysis measurements were then performed by two observers. Reliabilities were tested by the Interclass Correlation Coefficient (ICC) and significance tested by ANOVA or the Kruskal Wallis test. No significant differences were detected in lateral cephalometric analysis measurements following adjustment of the image enhancement brightness and contrast. The limit value of adjustments of the image enhancement brightness and contrast associated with incremental 10-point changes (-30, -20, -10, 0, +10, +20, +30) does not affect the results of Steiner analysis.

  18. Contrast enhanced MR imaging of female pelvic cancers: Established methods and emerging applications

    Energy Technology Data Exchange (ETDEWEB)

    Punwani, Shonit, E-mail: shonit.punwani@gmail.com [Department of Academic Radiology, 2nd Floor Podium, University College London Hospital, 235 Euston Road, London NW1 2BU (United Kingdom)

    2011-04-15

    Contrast enhanced magnetic resonance imaging of female pelvic cancers has been established for over 20 years. Conventional contrast enhanced imaging involves acquiring a set of pre-contrast T1 weighted images, followed by intravenous injection of an gadolinium based contrast agent and subsequent acquisition of a second set of contrast enhanced images. Developments in MR hardware and pulse sequences over the last 10 years have made dynamic contrast enhanced (DCE) protocols possible. DCE-MRI entails imaging of the same volume repeatedly prior to, during and following contrast injection. There have also been developments in image analysis methods and tools to reflect the increased data acquired. Qualitative analysis of contrast enhanced imaging (whether a single set or temporal series) by radiologists remains the mainstay for clinical reporting. Semi-quantitative assessment of signal intensity versus time curves and full pharmacokinetic modelling methods have emerged for evaluation of DCE-MRI data. DCE-MRI has found an established role in the detection, localisation and staging of female pelvic malignancies. Emerging applications of DCE-MRI include assessment of tumour grade, histology prior to and following treatment and prediction of individual and final treatment outcome. This article reviews the biophysical basis of contrast enhancement, the technical aspects of performance and analysis of DCE-MRI studies, and the established and emerging clinical utility of DCE-MRI in female pelvic malignancies.

  19. Evaluation of breast lesions with contrast-enhanced ultrasound using the microvascular imaging technique: initial observations.

    Science.gov (United States)

    Liu, He; Jiang, Yu-Xin; Liu, Ji-Bin; Zhu, Qing-Li; Sun, Qiang

    2008-10-01

    The objective of this study was to evaluate the usefulness of contrast-enhanced ultrasound using the microvascular imaging technique in the diagnosis of breast lesions. In 104 patients with 104 breast lesions scheduled for surgery, conventional and contrast-enhanced ultrasound using the microvascular imaging technique were performed after administration of SonoVue. The enhancement patterns of breast lesions were classified as no enhancement, peripheral enhancement, homogeneous enhancement, regional enhancement, or heterogeneous enhancement based on the morphologic features of enhancement. The diagnostic value of contrast-enhanced ultrasound using the microvascular imaging technique was analyzed with the observers blinded to the clinical data and pathology (which served as the gold standard). None of the enhancement patterns was suggestive of benignity, with a sensitivity of 18.3%, specificity of 97.7%, positive predictive value (PPV) of 91.7%, negative predictive value (NPV) of 46.2%, and accuracy of 51.5%. The peripheral enhancement pattern was suggestive of malignancy, with a sensitivity of 39.5%, specificity of 98.3%, PPV of 94.4%, NPV of 69.4%, and accuracy of 73.8%. Homogeneous, regional, and heterogeneous enhancement patterns did not show meaningful diagnostic information. Contrast-enhanced ultrasound using the microvascular imaging technique provides diagnostic information on breast lesions.

  20. Anemia and the risk of contrast-induced nephropathy in patients with renal insufficiency undergoing contrast-enhanced MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Ryusuke, E-mail: rywakana@nms.ac.jp; Kumita, Shin-ichiro; Hayashi, Hiromitsu; Sugizaki, Ken-ichi; Okazaki, Emi; Kiriyama, Tomonari; Hakozaki, Kenta; Tani, Hitomi; Miki, Izumi; Takeda, Minako

    2013-10-01

    Purpose: The purpose of this study was to assess the effect of anemia on the incidence of contrast-induced nephropathy (CIN) in patients with renal impairment undergoing MDCT. Materials and methods: Institutional review board approval was waived for this retrospective review of 843 patients with stable renal insufficiency (eGFR between 15 and 60 mL/min) who had undergone contrast-enhanced MDCT. Baseline hematocrit and hemoglobin values were measured. Serum creatinine (SCr) was assessed at the baseline and at 48–72 h after contrast administration. Results: The overall incidence of CIN in the patient population with renal insufficiency was 6.9%. CIN developed in 7.8% (54 of 695) of anemic patients, and in 2.8% (4 of 148) of non-anemic patients (P = .027). After adjustment for confounders, low hemoglobin and low hematocrit values remained independent predictors of CIN (odds ratio 4.6, 95% CI 1.0–20.5, P = .046). Conclusions: Anemia is associated with a higher incidence of CIN in patients with renal insufficiency. Anemia is a potentially modifiable risk factor for CIN, and has an unfavorable impact on prognosis in patients with renal insufficiency undergoing contrast-enhanced MDCT.

  1. An Improved Local Equilibrium Contrast Enhancement Algorithm for Infrared Laser Images

    OpenAIRE

    Yuhong Li; Jianzhong Zhou; Wei Ding; Shan Ding

    2010-01-01

    An improved local equilibrium contrast enhancement algorithm based self-adaptive contrast enhancement algorithm is proposed for infrared laser images, in which the image pixel value histogram is divided into three parts: background and noise area, targets area, and uninterested area. The targets parts are highlighted, while the background and noise parts and the uninterested parts are restrained. A comprehensive qualitative and quantitative image enhancement performance evaluation is presente...

  2. Characterization of solitary pulmonary nodules: Use of washout characteristics at contrast-enhanced computed tomography

    OpenAIRE

    YE, XIAO-DAN; YE, JIAN-DING; YUAN, ZHENG; DONG, SHENG; XIAO, XIANG-SHENG

    2011-01-01

    The purpose of this study was to determine whether computed tomographic scans and attenuation measurements on contrast material-enhanced and non-enhanced computed tomographic scans could be used to characterize solitary pulmonary nodules and, in particular, to characterize these lesions using washout characteristics on contrast-enhanced computed tomography. A total of 63 patients (38 males, 25 females; age range, 21–80 years; mean age, 58±13.2 years) with pulmonary nodules revealed on contras...

  3. Diagnostic and prognostic values of contrast-enhanced ultrasound in breast cancer: a retrospective study.

    Science.gov (United States)

    Zhao, Yi-Xuan; Liu, Shuang; Hu, Yan-Bing; Ge, Yan-Yan; Lv, Dong-Mei

    2017-01-01

    This study aimed to explore the diagnostic and prognostic values of contrast-enhanced ultrasound (CEUS) in breast cancer. Between September 2009 and October 2011, a total of 143 breast cancer patients and 161 healthy people were selected as case group and control group, respectively. After the identification of lesions by conventional ultrasound, all patients underwent CEUS. The CEUS images were analyzed, and time-intensity curves (TICs) were obtained. Hematoxylin-eosin and immunohistochemistry staining was performed on tissue specimens, according to which the expressions of estrogen receptor (ER), c-erb-B2, p53, and Ki-67 were measured. Multivariate logistic regression analysis was used to compare CEUS and TIC parameters between the two groups. Compared with the control group, cancer patients showed high enhancement, heterogeneous enhancement or defects in the central region, expansion of lesion diameter after enhancement and crab-like blur lesion edges. The peak intensity (PI), relative start time of enhancement, relative PI, and relative area under the curve in the case group were significantly higher than those in the control group. Logistic analysis showed that the uniformity of enhancement, expansion of lesion diameter, and relative PI were significant diagnostic parameters of breast cancer, with area under the curve being 0.798, 0.776, and 0.919, respectively. There were strong associations between CEUS characteristics and expressions of prognostic factors in breast cancer: the heterogeneous enhancement was common in c-erb-B2-positive tumors; the centripetal enhancement occurred more in ER-negative tumors; perforator vessels were often seen in tumors at high histological grade; perfusion defects were common in ER-negative, c-erb-B2-positive, and Ki-67-positive tumors. CEUS is a useful tool for the early diagnosis and prognosis of breast cancer.

  4. Generation and modelling of megavoltage photon beams for contrast-enhanced radiation therapy

    Science.gov (United States)

    Robar, J. L.

    2006-11-01

    Contrast-enhanced radiation therapy (CERT) is a treatment approach involving the irradiation of tumours containing high atomic number (Z) contrast media, using low-quality x-ray beams. This work describes the experimental generation of x-ray beams using a linear accelerator with low-Z target materials (beryllium and aluminium), in order to produce photon energy spectra appropriate for CERT. Measurements were made to compare the experimental beams to conventional linear accelerator photon beams in terms of per cent depth dose. Monte Carlo simulation was used to model the generation of each beam, and models were validated against experimental measurement. Validated models were used to demonstrate changes in photon spectra as well as to quantify the variation of tumour dose enhancement with iodinated contrast medium concentration in a simulated tumour volume. Finally, the ratio of the linear attenuation coefficient for iodinated contrast medium relative to water was determined experimentally as a function of iodine concentration. Beams created with low-Z targets show significant changes in energy spectra compared to conventional beams. For the 4 MeV/Be beam, for example, 33% of photons have energies below 60 keV. Measurements and calculation show that both the linear attenuation coefficient ratio and dose enhancement factor (DEF) increase most rapidly at concentrations below 46 mg I ml-1. There is a significant dependence of DEF on electron energy and a lesser dependence on target material. The 4 MeV/Be beam is the most promising in terms of magnitude of DEF—for example, DEF values of 1.16 and 1.29 are obtained for concentrations of 20 mg I ml-1 and 50 mg I ml-1, respectively. DEF will increase or decrease, respectively, for shallower or deeper tumours at a rate of approximately 1.1% cm-1. In summary, we show that significant dose enhancement is possible by altering the linear accelerator target and filtration, but the magnitude is highly dependent on contrast

  5. Identifying the association between contrast enhancement pattern, surgical resection, and prognosis in anaplastic glioma patients

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yinyan; Jiang, Tao [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Capital Medical University, Beijing Neurosurgical Institute, Beijing (China); Wang, Kai; Li, Shaowu; Ma, Jun [Capital Medical University, Department of Neuroradiology, Beijing Tiantan Hospital, Beijing (China); Wang, Jiangfei [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Dai, Jianping [Capital Medical University, Beijing Neurosurgical Institute, Beijing (China); Capital Medical University, Department of Neuroradiology, Beijing Tiantan Hospital, Beijing (China)

    2016-04-15

    Contrast enhancement observable on magnetic resonance (MR) images reflects the destructive features of malignant gliomas. This study aimed to investigate the relationship between radiologic patterns of tumor enhancement, extent of resection, and prognosis in patients with anaplastic gliomas (AGs). Clinical data from 268 patients with histologically confirmed AGs were retrospectively analyzed. Contrast enhancement patterns were classified based on preoperative T1-contrast MR images. Univariate and multivariate analyses were performed to evaluate the prognostic value of MR enhancement patterns on progression-free survival (PFS) and overall survival (OS). The pattern of tumor contrast enhancement was associated with the extent of surgical resection in AGs. A gross total resection was more likely to be achieved for AGs with focal enhancement than those with diffuse (p = 0.001) or ring-like (p = 0.024) enhancement. Additionally, patients with focal-enhanced AGs had a significantly longer PFS and OS than those with diffuse (log-rank, p = 0.025 and p = 0.031, respectively) or ring-like (log-rank, p = 0.008 and p = 0.011, respectively) enhanced AGs. Furthermore, multivariate analysis identified the pattern of tumor enhancement as a significant predictor of PFS (p = 0.016, hazard ratio [HR] = 1.485) and OS (p = 0.030, HR = 1.446). Our results suggested that the contrast enhancement pattern on preoperative MR images was associated with the extent of resection and predictive of survival outcomes in AG patients. (orig.)

  6. Atypical focal non-neoplastic brain changes in neurofibromatosis type 1: mass effect and contrast enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Raininko, R. [Dept. of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala University (Sweden); Thelin, L. [Dept. of Pediatrics, Gaevle County Hospital (Sweden); Eeg-Olofsson, O. [Dept. of Women' s and Children' s Health, Section of Pediatrics, Uppsala University (Sweden)

    2001-07-01

    Abstract Children and young adults with neurofibromatosis type 1 often have small high-signal foci on T2-weighted images of the brain. We describe follow-up of two patients in whom one of the foci had atypical features, commonly regarded as signs of a neoplasm. In the first, one lesion showed temporary contrast enhancement and decreasing mass effect. The second developed an expanding lesion that increased minimally in size over 4.5 year's follow-up. The borderline between neoplastic and non-neoplastic lesions seems to be indistinct. (orig.)

  7. Dynamic contrast-enhanced magnetic resonance imaging of the wrist in children with juvenile idiopathic arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Nusman, Charlotte M. [Emma Children' s Hospital, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Academic Medical Center, Amsterdam (Netherlands); Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Lavini, Cristina; Hemke, Robert; Caan, Matthan W.A.; Maas, Mario [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Schonenberg-Meinema, Dieneke; Berg, J.M. van den; Kuijpers, Taco W. [Emma Children' s Hospital, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Academic Medical Center, Amsterdam (Netherlands); Dolman, Koert M. [Sint Lucas Andreas Hospital, Department of Pediatrics, Amsterdam (Netherlands); Reade Institute location Jan van Breemen, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Rossum, Marion A.J. van [Reade Institute location Jan van Breemen, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Emma Children' s Hospital, Department of Pediatrics, Academic Medical Center, Amsterdam (Netherlands)

    2017-02-15

    Dynamic contrast-enhanced MRI provides information on the heterogeneity of the synovium, the primary target of disease in children with juvenile idiopathic arthritis (JIA). To evaluate the feasibility of dynamic contrast-enhanced MRI in the wrist of children with JIA using conventional descriptive measures and time-intensity-curve shape analysis. To explore the association between enhancement characteristics and clinical disease status. Thirty-two children with JIA and wrist involvement underwent dynamic contrast-enhanced MRI with movement-registration and were classified using validated criteria as clinically active (n = 27) or inactive (n = 5). Outcome measures included descriptive parameters and the classification into time-intensity-curve shapes, which represent the patterns of signal intensity change over time. Differences in dynamic contrast-enhanced MRI outcome measures between clinically active and clinically inactive disease were analyzed and correlation with the Juvenile Arthritis Disease Activity Score was determined. Comprehensive evaluation of disease status was technically feasible and the quality of the dynamic dataset was improved by movement registration. The conventional descriptive measure maximum enhancement differed significantly between clinically active and inactive disease (P = 0.019), whereas time-intensity-curve shape analysis showed no differences. Juvenile Arthritis Disease Activity Score correlated moderately with enhancing volume (P = 0.484). Dynamic contrast-enhanced MRI is a promising biomarker for evaluating disease status in children with JIA and wrist involvement. Conventional descriptive dynamic contrast-enhanced MRI measures are better associated with clinically active disease than time-intensity-curve shape analysis. (orig.)

  8. Optimal Analysis Method for Dynamic Contrast-Enhanced Diffuse Optical Tomography

    Directory of Open Access Journals (Sweden)

    Michael Ghijsen

    2011-01-01

    Full Text Available Diffuse Optical Tomography (DOT is an optical imaging modality that has various clinical applications. However, the spatial resolution and quantitative accuracy of DOT is poor due to strong photon scatting in biological tissue. Structural a priori information from another high spatial resolution imaging modality such as Magnetic Resonance Imaging (MRI has been demonstrated to significantly improve DOT accuracy. In addition, a contrast agent can be used to obtain differential absorption images of the lesion by using dynamic contrast enhanced DOT (DCE-DOT. This produces a relative absorption map that consists of subtracting a reconstructed baseline image from reconstructed images in which optical contrast is included. In this study, we investigated and compared different reconstruction methods and analysis approaches for regular endogenous DOT and DCE-DOT with and without MR anatomical a priori information for arbitrarily-shaped objects. Our phantom and animal studies have shown that superior image quality and higher accuracy can be achieved using DCE-DOT together with MR structural a priori information. Hence, implementation of a combined MRI-DOT system to image ICG enhancement can potentially be a promising tool for breast cancer imaging.

  9. Contrast enhancement based on entropy and reflectance analysis for surgical lighting

    Science.gov (United States)

    Shen, Junfei; Wang, Huihui; Wu, Yisi; Li, An; Chen, Chi; Zheng, Zhenrong

    2015-07-01

    Light-emitting diode (LED) is the neotype surgical lighting device as an inexpensive and color-variable illumination. A methodology was designed to value the quality of surgical lighting and used to develop an operation lamp with LEDs enhancing the biological contrast. We assembled a modular array of Phillips LEDs as illumination. In the initial experiment, images of porcine heart were carried out in several LED environments and analyzed quantitatively to assess the function of these LEDs in contrast enhancement. Then we measured the reflectance spectrums of blood, fat and other tissues to obtain the spectral comparison. Based on the result, new illuminations with spectral components which differ most in the comparison was developed. Meanwhile, a new evaluation function combining the entropy analysis and brightness contrast was also built to value the quality of these illuminations. Experiments showed biological features are more visible with treated LED illuminations than the broadband lamps. Thus, the synthesis of LED lighting spectra could be adjusted to provide significant tissue identification. Therefore, we believe the new methodology will contribute to the manufacture of high efficient medical illuminations and act the positive role in coming surgical lighting fields.

  10. Effects of noradrenaline and adenosine triphosphate on the degree on contrast enhancement in a rabbit model of atherosclerosis during contrast-enhanced ultrasonography.

    Science.gov (United States)

    Sun, Jie; Deng, You-Bin; Liu, Kun; Wang, Yu-Bo

    2014-11-01

    The aim of the study is to assess the effects of vasoactive agents on the degree of contrast enhancement in experimental atherosclerotic plaque during contrast-enhanced ultrasonography (CEUS). Abdominal aortic atherosclerosis was induced in 25 New Zealand white rabbits by a combination of cholesterol-rich diet and balloon endothelial denudation. Standard ultrasonography and CEUS were performed at baseline and during intravenous infusion of noradrenaline or adenosine triphosphate (ATP). The degree of contrast enhancement of the plaque after injection of contrast material was quantified by calculating the enhanced intensity in the plaque. The infusion of noradrenaline induced significant increase in systolic blood pressure (84 ± 13 mm Hg vs. 112 ± 20 mm Hg, p = 0.011) and significant decrease in the enhanced intensity in the plaque (7.52 ± 1.32 dB vs. 5.88 ± 1.33 dB, p < 0.001) during CEUS. The infusion of ATP resulted in the significant decrease in systolic blood pressure (80 ± 13 mm Hg vs. 65 ± 11 mm Hg, p = 0.005) and increase in the enhanced intensity in the plaque (7.52 ± 1.32 dB vs. 8.84 ± 1.55 dB, p < 0.001) during CEUS. The degree of contrast enhancement within an experimental atherosclerotic plaque during CEUS can be influenced by vasoactive agents and hemodynamic status. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  11. Diagnostic and prognostic values of contrast-enhanced ultrasound in breast cancer: a retrospective study

    Directory of Open Access Journals (Sweden)

    Zhao YX

    2017-02-01

    Full Text Available Yi-Xuan Zhao, Shuang Liu, Yan-Bing Hu, Yan-Yan Ge, Dong-Mei Lv Department of Ultrasound, Second Hospital, Jilin University, Changchun, People’s Republic of China Abstract: This study aimed to explore the diagnostic and prognostic values of contrast-enhanced ultrasound (CEUS in breast cancer. Between September 2009 and October 2011, a total of 143 breast cancer patients and 161 healthy people were selected as case group and control group, respectively. After the identification of lesions by conventional ultrasound, all patients underwent CEUS. The CEUS images were analyzed, and time–intensity curves (TICs were obtained. Hematoxylin–eosin and immunohistochemistry staining was performed on tissue specimens, according to which the expressions of estrogen receptor (ER, c-erb-B2, p53, and Ki-67 were measured. Multivariate logistic regression analysis was used to compare CEUS and TIC parameters between the two groups. Compared with the control group, cancer patients showed high enhancement, heterogeneous enhancement or defects in the central region, expansion of lesion diameter after enhancement and crab-like blur lesion edges. The peak intensity (PI, relative start time of enhancement, relative PI, and relative area under the curve in the case group were significantly higher than those in the control group. Logistic analysis showed that the uniformity of enhancement, expansion of lesion diameter, and relative PI were significant diagnostic parameters of breast cancer, with area under the curve being 0.798, 0.776, and 0.919, respectively. There were strong associations between CEUS characteristics and expressions of prognostic factors in breast cancer: the heterogeneous enhancement was common in c-erb-B2-positive tumors; the centripetal enhancement occurred more in ER-negative tumors; perforator vessels were often seen in tumors at high histological grade; perfusion defects were common in ER-negative, c-erb-B2-positive, and Ki-67-positive tumors

  12. CT Angiography: Post-processed Contrast Enhancement for Improved Detection of Pulmonary Embolism.

    Science.gov (United States)

    Muenzel, Daniela; Fingerle, Alexander A; Zahel, Tina; Sauter, Andreas; Vlassenbroek, Alain; Dobritz, Martin; Rummeny, Ernst J; Noël, Peter B

    2017-02-01

    The study aimed to improve the detection of pulmonary embolism via an iodine contrast enhancement tool in patients who underwent suboptimal enhanced computed tomography angiography (CTA). We evaluated the CT examinations of 41 patients who underwent CTA for evaluation of the pulmonary arteries which suffered from suboptimal contrast enhancement. The contrast enhancement of the reconstructed images was increased via a post-processing tool (vContrast). Image noise and contrast-to-noise ratio (CNR) were assessed in eight different regions: main pulmonary artery, right and left pulmonary arteries, right and left segment arteries, muscle, subcutaneous fat, and bone. For subjective image assessment, three experienced radiologists evaluated the diagnostic quality. While employing the post-processing algorithm, the CNR for contrast-filled lumen and thrombus/muscle improves significantly by a factor of 1.7 (CNR without vContrast = 8.48 ± 6.79/CNR with vContrast = 14.46 ± 5.29) (P image analysis illustrated a significant improvement using post-processing for clinically relevant criteria such as diagnostic confidence. vContrast makes CT angiograms with inadequate contrast applicable for diagnostic evaluation, offering an improved visualization of the pulmonary arteries. In addition, vContrast can help in the significant reduction of the iodine contrast material. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  13. Evaluation of the minimum iodine concentration for contrast-enhanced subtraction mammography.

    Science.gov (United States)

    Baldelli, P; Bravin, A; Di Maggio, C; Gennaro, G; Sarnelli, A; Taibi, A; Gambaccini, M

    2006-09-07

    Early manifestation of breast cancer is often very subtle and is displayed in a complex and variable pattern of normal anatomy that may obscure the disease. The use of dual-energy techniques, that can remove the structural noise, and contrast media, that enhance the region surrounding the tumour, could help us to improve the detectability of the lesions. The aim of this work is to investigate the use of an iodine-based contrast medium in mammography with two different double exposure techniques: K-edge subtraction mammography and temporal subtraction mammography. Both techniques have been investigated by using an ideal source, like monochromatic beams produced at a synchrotron radiation facility and a clinical digital mammography system. A dedicated three-component phantom containing cavities filled with different iodine concentrations has been developed and used for measurements. For each technique, information about the minimum iodine concentration, which provides a significant enhancement of the detectability of the pathology by minimizing the risk due to high dose and high concentration of contrast medium, has been obtained. In particular, for cavities of 5 and 8 mm in diameter filled with iodine solutions, the minimum concentration needed to obtain a contrast-to-noise ratio of 5 with a mean glandular dose of 2 mGy has been calculated. The minimum concentrations estimated with monochromatic beams and K-edge subtraction mammography are 0.9 mg ml(-1) and 1.34 mg ml(-1) for the biggest and smallest details, respectively, while for temporal subtraction mammography they are 0.84 mg ml(-1) and 1.31 mg ml(-1). With the conventional clinical system the minimum concentrations for the K-edge subtraction mammography are 4.13 mg ml(-1) (8 mm diameter) and 5.75 mg ml(-1) (5 mm diameter), while for the temporal subtraction mammography they are 1.01 mg ml(-1) (8 mm diameter) and 1.57 mg ml(-1) (5 mm diameter).

  14. Contrast-agent-enhanced magnetic resonance imaging: early detection of neoplastic lesions of the CNS

    Science.gov (United States)

    Carvlin, Mark J.; Rosa, Louis; Rajan, Sunder S.; Francisco, John

    1991-06-01

    Even though the intrinsic soft tissue contrast sensitivity of magnetic resonance imaging (MRI) affords excellent visualization of anatomic detail, certain pathologic processes may be diagnosed earlier with the administration of a contrast-enhancing agent. At present there is one agent, gadopentetate dimeglumine, GdDTPA, that has received FDA approval for use in the MR scanning of the brain and spine in human patients. This paramagnetic chelate distributes throughout the extracellular fluid space as dictated by capillary permeability so that abnormal vascularity and sites of blood-CNS barrier breakdown are highlighted. Primary neoplastic disease, metastases, meningeal extension, residual and recurrent tumor have been found to be better distinguished in MR images acquired after administration of GdDTPA. Routine administration of GdDTPA for cranial imaging has resulted in the discovery of otherwise occult lesions in approximately 3 of patients. Although the clinical utility and high therapeutic safety index of the first approved magnetic resonance contrast agent, GdDTPA, have been well established, other contrast agents, having different physical, chemical and biological properties, may offer improved sensitivity and bio-specificity. Agents currently being evaluated in vivo include: low osmolal paramagnetic chelates, superparamagnetic particles, metalloporphyrins, liposome encapsulated agents, perfluorocarbons, intravascular macromolecular chelate complexes and labeled monoclonal antibodies. Concurrent with advances in the development of new compounds, innovations in scanning hardware, pulse sequence design and image post-processing are helping to extend the efficacy of contrast media. Additional clinical experience will indicate which contrast agents and which MR techniques can best facilitate the early detection of specific neoplastic lesions.

  15. A comparative study on preprocessing techniques in diabetic retinopathy retinal images: illumination correction and contrast enhancement.

    Science.gov (United States)

    Rasta, Seyed Hossein; Partovi, Mahsa Eisazadeh; Seyedarabi, Hadi; Javadzadeh, Alireza

    2015-01-01

    To investigate the effect of preprocessing techniques including contrast enhancement and illumination correction on retinal image quality, a comparative study was carried out. We studied and implemented a few illumination correction and contrast enhancement techniques on color retinal images to find out the best technique for optimum image enhancement. To compare and choose the best illumination correction technique we analyzed the corrected red and green components of color retinal images statistically and visually. The two contrast enhancement techniques were analyzed using a vessel segmentation algorithm by calculating the sensitivity and specificity. The statistical evaluation of the illumination correction techniques were carried out by calculating the coefficients of variation. The dividing method using the median filter to estimate background illumination showed the lowest Coefficients of variations in the red component. The quotient and homomorphic filtering methods after the dividing method presented good results based on their low Coefficients of variations. The contrast limited adaptive histogram equalization increased the sensitivity of the vessel segmentation algorithm up to 5% in the same amount of accuracy. The contrast limited adaptive histogram equalization technique has a higher sensitivity than the polynomial transformation operator as a contrast enhancement technique for vessel segmentation. Three techniques including the dividing method using the median filter to estimate background, quotient based and homomorphic filtering were found as the effective illumination correction techniques based on a statistical evaluation. Applying the local contrast enhancement technique, such as CLAHE, for fundus images presented good potentials in enhancing the vasculature segmentation.

  16. Fibroadenomas of the breast: histopathological/dynamic contrast-enhanced MR correlation

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, R. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Garnier, C. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Meingan, P. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Zemoura, L. [Dept. of Histopathology C, Inst. Gustave Roussy, 94 - Villejuif (France); Lucidarme, O. [Dept. of Radiology, Hopital Salpetriere, 75 - Paris (France); Guinebretiere, J.M. [Dept. of Histopathology C, Inst. Gustave Roussy, 94 - Villejuif (France); Tardivon, A.A. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Arriagada, R. [Breast Cancer Study Group, Inst. Gustave Roussy, 94 - Villejuif, (France)

    1995-12-31

    A total of 22 women with fibroadenomas had preoperative dynamic MR study (T1-weighted images every 47 s after injection of Gd-DOTA). Their age, hormonal status, breast MR studies and histopathological slides were retrospectively reviewed. Eleven pre- (n = 2) or post-menopausal (n = 9) women showed no early contrast enhancement. The absence of early contrast enhancement correlated with hyalin stromal component. Eleven pre- (n = 7) or post-menopausal (n = 4) women showed focal (n = 9) or diffuse (n = 2) early contrast enhancement. Early focal contrast enhancement correlated with myxoid (n = 9), mixed hyalin/myxoid (n = 1) or hyalin (n = 1) fibroadenomas. Early diffuse contrast enhancement of the breast correlated with myxoid (n = 1) or hyalin (n = 1) stromal component associated with proliferative fibrocystic disease of the breast parenchyma. The presence of contrast enhancement correlated with myxoid fibroadenomas, whereas absence of contrast enhancement correlated with hyalin fibroadenomas. As hyalin fibroadenomas occurs in post-menopausal women, the diagnostic accuracy of dynamic MRI may be improved in this age group. (orig.)

  17. Magnetic resonance imaging contrast enhancement of brain tumors at 3 tesla versus 1.5 tesla.

    Science.gov (United States)

    Nöbauer-Huhmann, Iris-Melanie; Ba-Ssalamah, Ahmed; Mlynarik, Vladimir; Barth, Markus; Schöggl, Alexander; Heimberger, Karl; Matula, Christian; Fog, Amura; Kaider, Alexandra; Trattnig, Siegfried

    2002-03-01

    To compare the diagnostic efficacy of a standard dose of MRI contrast agent in the evaluation of primary brain tumors and metastases using a high-field 3 tesla MR unit versus a 1.5 tesla MR unit. Sixteen patients with brain tumors were examined at both field strengths using identical axial T1-SE protocols pre- and postcontrast (0.1 mmol/kg gadolinium), and postcontrast coronal 3D GRE with magnetization preparation (MP-RAGE), which was adjusted separately for each field strength. Evaluation of the images was performed quantitatively and, in the case of T1-SE images, also by visual assessment. Tumor-to-brain-contrast after gadolinium administration using statistical evaluation of MP-RAGE scans was significantly higher at 3 tesla (97.5) than at 1.5 tesla (46.3). The same was true for T1-SE sequences (93.0 vs. 72.1). Signal enhancement of the lesions in T1-SE sequences was not significantly different between both field strengths. Administration of a gadolinium contrast agent produces higher contrast between tumor and normal brain at 3 tesla than at 1.5 tesla.

  18. Non-enhanced MR angiography of renal arteries - Comparison with contrast-enhanced MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Angeretti, M. G.; Lumia, D.; Cani, A.; Barresi, M.; Cardim, L Nocchi; Piacentino, F.; Genovese, E. A.; Fugazzola, C. [Dept. of Radiology, Insubria Univ., Ospedale di Circolo e Fondazione Macchi, Varese (Italy)], e-mail: laranocchi@gmail.com; Maresca, A. M. [Dept. of Internal Medicine, Insubria Univ., Ospedale di Circolo e Fondazione Macchi, Varese (Italy); Novario, R. [Dept. of Medical Physics, Insubria Univ., Ospedale di Circolo e Fondazione Macchi, Varese (Italy)

    2013-09-15

    Background: The main causes of renal artery stenosis (RAS) are atherosclerosis and fibromuscular dysplasia. Despite contrast-enhanced magnetic resonance angiography (CE-MRA) being a safe and reliable method for diagnosis of RAS especially in young individuals, recently it has been possible to adopt innovative technologies that do not require paramagnetic contrast agents. Purpose: To assess the accuracy of steady-state free-precession (SSFP) non-contrast-enhanced magnetic resonance angiography (NC-MRA) by using a 1.5 T MR scanner for the detection of renal artery stenosis, in comparison with breath-hold CE-MRA as the reference standard. Material and Methods: Sixty-three patients (33 men, 30 women) with suspected renovascular hypertension (RVHT) were examined by a 1.5T MR scanner; NC-MRA with an electrocardiography (ECG)-gated SSFP sequence was performed in 58.7% (37/63) of patients; in 41.3% (26/63) of patients a respiratory trigger was used in addition to cardiac gating. CE-MRA, with a three-dimensional gradient echo (3D-GRE) T1-weighted sequence, was performed in all patients within the same session. Maximum intensity projection (MIP) image quality, number of renal arteries, and the presence of stenosis were assessed by two observers (independently for NC-MRA and together for CE-MRA). The agreement between NC-MRA and CE-MRA as well as the inter-observer reproducibility were calculated with Bland-Altman plots. Results: MIP image quality was considered better for NC-MRA. NC-MRA identified 143 of 144 (99.3%) arteries detected by CE-MRA (an accessory artery was not identified). Fourteen stenoses were detected by CE-MRA (11 atherosclerotic, 3 dysplastic) with four of 14 (28.5%) significant stenosis. Bland-Altman plot demonstrated an excellent concordance between NC-MRA and CE-MRA; particularly, the reader A evaluated correctly all investigated arteries, while over-estimation of two stenoses occurred for reader B. Regarding NC-MRA, inter-observer agreement was excellent

  19. Impact of image acquisition timing on image quality for dual energy contrast-enhanced breast tomosynthesis

    Science.gov (United States)

    Hill, Melissa L.; Mainprize, James G.; Puong, Sylvie; Carton, Ann-Katherine; Iordache, Razvan; Muller, Serge; Yaffe, Martin J.

    2012-03-01

    Dual-energy contrast-enhanced digital breast tomosynthesis (DE CE-DBT) image quality is affected by a large parameter space including the tomosynthesis acquisition geometry, imaging technique factors, the choice of reconstruction algorithm, and the subject breast characteristics. The influence of most of these factors on reconstructed image quality is well understood for DBT. However, due to the contrast agent uptake kinetics in CE imaging, the subject breast characteristics change over time, presenting a challenge for optimization . In this work we experimentally evaluate the sensitivity of the reconstructed image quality to timing of the low-energy and high-energy images and changes in iodine concentration during image acquisition. For four contrast uptake patterns, a variety of acquisition protocols were tested with different timing and geometry. The influence of the choice of reconstruction algorithm (SART or FBP) was also assessed. Image quality was evaluated in terms of the lesion signal-difference-to-noise ratio (LSDNR) in the central slice of DE CE-DBT reconstructions. Results suggest that for maximum image quality, the low- and high-energy image acquisitions should be made within one x-ray tube sweep, as separate low- and high-energy tube sweeps can degrade LSDNR. In terms of LSDNR per square-root dose, the image quality is nearly equal between SART reconstructions with 9 and 15 angular views, but using fewer angular views can result in a significant improvement in the quantitative accuracy of the reconstructions due to the shorter imaging time interval.

  20. Portal biliopathy diagnosed using color Doppler and contrast-enhanced ultrasound.

    Science.gov (United States)

    Nunoi, Hiroaki; Hirooka, Masashi; Ochi, Hironori; Koizumi, Yohei; Tokumoto, Yoshio; Abe, Masanori; Tada, Fujimasa; Ikeda, Yoshio; Matsuura, Bunzo; Tanaka, Hiroaki; Tsuda, Takaharu; Mochizuki, Teruhito; Hiasa, Yoichi; Onji, Morikazu

    2013-01-01

    Portal biliopathy is a morphological abnormality of the biliary ductal and gallbladder wall associated with portal hypertension. A patient with essential thrombocythemia was initially diagnosed with extrahepatic portal vein obstruction (EHPVO). The contrast-enhanced computed tomography (CT) findings were similar to those of cholangiocarcinoma or sclerosing cholangitis. However, color Doppler and contrast-enhanced ultrasound (US) were more specific. The paracholedocheal veins around the bile ducts appeared as beads soon after the injection of contrast medium, followed by linear enhancement of the epicholedochal veins and the gradual enhancement of the whole bile ducts. These findings led to a diagnosis of portal biliopathy, which prevented the patient from having to endure hazardous procedures such as bile duct biopsies. Color Doppler and contrast-enhanced US findings are useful for diagnosing or ruling out portal biliopathy in patients who present with EHPVO.

  1. Description of the use of contrast-enhanced ultrasonography in four dogs with pancreatic tumours.

    Science.gov (United States)

    Vanderperren, K; Haers, H; Van der Vekens, E; Stock, E; Paepe, D; Daminet, S; Saunders, J H

    2014-03-01

    Canine pancreatic tumours are rare compared to human medicine and the detection and differentiation of pancreatic neoplasia is challenging with B-mode ultrasonography, which often leads to late clinical diagnosis and poor prognosis. This case report describes the findings of contrast-enhanced ultrasonography in four dogs with pancreatic adenocarcinoma or insulinoma. B-mode ultrasonography of the pancreas revealed a hypoechoic nodule in three dogs and heterogenous tissue in one dog. Contrast-enhanced ultrasonography was able to differentiate between two tumour types: adenocarcinomas showed hypoechoic and hypovascular lesions, whereas insulinomas showed uniformly hypervascular lesions. Contrast-enhanced ultrasonography findings were confirmed by cytology and/or histopathology. The results demonstrated that contrast-enhanced ultrasonography was able to establish different enhancement patterns between exocrine (adenocarcinoma) and endocrine (insulinoma) tumours in dogs.

  2. Clinical impact of hyperattenuation of adrenal glands on contrast-enhanced computed tomography of polytraumatised patients.

    Science.gov (United States)

    Schek, J; Macht, S; Klasen-Sansone, J; Heusch, P; Kröpil, P; Witte, I; Antoch, G; Lanzman, R S

    2014-02-01

    To evaluate the prognostic value of hyperattenuating adrenal glands on contrast-enhanced CT of polytraumatised patients. Two hundred ninety-two patients (195 men and 97 women, mean age 45.3 ± 23.3 years) were included in this retrospective study. CT examinations were performed 60 s after intravenous injection of contrast material. Image analysis was performed by two radiologists. Patients were assigned to one of two groups according to the attenuation of the adrenal gland [group 1: adrenal glands ≥ inferior vena cava (IVC); group 2: adrenal glands adrenal density was 150.8 ± 36.1 HU in group 1 and 83.7 ± 23.6 HU in group 2 (P adrenal enhancement was significantly higher in patients who died (101.9 ± 40.6 HU) compared with survivors (86.1 ± 27.0 HU; P adrenal glands is associated with a higher mortality rate in polytraumatised patients and may serve as a predictor of poor clinical outcome. • Hyperattenuating adrenal glands can be observed in 6.2% of polytraumatised patients. • Hyperattenuating adrenal glands indicate poor clinical outcome in polytraumatised patients. • In polytraumatised patients, hyperattenuating adrenal glands are associated with a high mortality rate. • Adrenal enhancement is higher amongst patients who died than amongst survivors.

  3. Enhanced phase contrast transfer using ptychography combined with a pre-specimen phase plate in a scanning transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hao; Ercius, Peter [Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Nellist, Peter D. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Ophus, Colin, E-mail: clophus@lbl.gov [Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2016-12-15

    The ability to image light elements in both crystalline and noncrystalline materials at near atomic resolution with an enhanced contrast is highly advantageous to understand the structure and properties of a wide range of beam sensitive materials including biological specimens and molecular hetero-structures. This requires the imaging system to have an efficient phase contrast transfer at both low and high spatial frequencies. In this work we introduce a new phase contrast imaging method in a scanning transmission electron microscope (STEM) using a pre-specimen phase plate in the probe forming aperture, combined with a fast pixelated detector to record diffraction patterns at every probe position, and phase reconstruction using ptychography. The phase plate significantly enhances the contrast transfer of low spatial frequency information, and ptychography maximizes the extraction of the phase information at all spatial frequencies. In addition, the STEM probe with the presence of the phase plate retains its atomic resolution, allowing simultaneous incoherent Z-contrast imaging to be obtained along with the ptychographic phase image. An experimental image of Au nanoparticles on a carbon support shows high contrast for both materials. Multislice image simulations of a DNA molecule shows the capability of imaging soft matter at low dose conditions, which implies potential applications of low dose imaging of a wide range of beam sensitive materials. - Highlights: • This work demonstrates a phase contrast imaging method by combining a pre-specimen phase plate with ptychogrpahy. • This method is shown to have a high phase contrast transfer efficiency at both low and high spatial frequencies. • Unlike CTEM which uses a heavy defocus to gain contrast, the phase plate gives a linear phase contrast at zero defocus aberrations. • Image simulations of DNA suggest this method is highly attractive for imaging beam sensitive materials at a low dose.

  4. Clinical use of gadobutrol for contrast-enhanced magnetic resonance imaging of neurological diseases

    Directory of Open Access Journals (Sweden)

    Cheng KT

    2012-02-01

    Full Text Available Kenneth T Cheng1, Hannah Y Cheng2, Kam Leung31Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA; 2Freelance Technical Writer, New Orleans, LA, USA; 3National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USAAbstract: Contrast-enhanced magnetic resonance imaging (CE-MRI is an important clinical tool for diagnosing neurological diseases. The appropriate use of a suitable MRI contrast agent or contrast pharmaceutical is essential for CE-MRI to produce desirable diagnostic images. Currently, there are seven contrast agents (CAs or pharmaceuticals approved for clinical imaging of the central nervous system (CNS in the US, Europe, or Japan. All of the clinically approved CAs are water-soluble gadolinium-based contrast agents (GBCAs which do not penetrate the CNS blood–brain barrier (BBB. These agents are used for imaging CNS areas without a BBB, or various pathologies, such as tumors and infection that break down the BBB and allow CAs to enter into the surrounding parenchyma. Clinically, GBCAs are most useful for detecting primary and secondary cerebral neoplastic lesions. Among these CNS GBCAs, gadobutrol (Gd-BT-DO3A, Gadovist™ is a neutral, nonionic, macrocyclic compound that showed promising results from clinical trials of CNS imaging. In comparison with other GBCAs, Gd-BT-DO3A has relatively high in vitro kinetic stability and r1 relaxivity. Gd-BT-DO3A has been recently approved by the US Food and Drug Administration (FDA in 2011 for CNS imaging. A review of available literature shows that Gd-BT-DO3A exhibits similar safety and clinical efficacy profiles to other GBCAs. Gd-BT-DO3A has the distinguishing feature that it is the only clinical agent commercially available in a formulation of 1.0 M concentration with a relatively higher in vitro T1 shortening per unit volume than other clinical GBCAs which are only

  5. Histological change and microcirculation in the contrast-enhancement region of cerebral infarction. An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Morimoto, Tetsuya; Takemura, Kiyoshi; Sakaki, Toshisuke; Hori, Yutaka (Nara National Hospital, Nara (Japan)); Yokoyama, Kazuhiro

    1983-08-01

    The purpose of this experiment is to reveal the microcirculation and blood-brain barrier by comparison with the histological findings in the contrast-enhancement region. The microcirculation is studied by carbon perfusion, and the function of the blood-brain barrier is studied by the intravenous administration of fluorescein. According to the carbon perfusion, carbon filling is impaired in the ischemic region of cerebral infarction. However, partially in the ischemic region, there is a good carbon-filling zone, called the carbon deposit, which indicates that the microcirculation develops better in this part of the ischemic region during the contrast-enhancement stage. From the histological point of view, the contrast-enhancement region contains capillaries and phagocytes and has a spongy appearance, an extravasation of red cells, and cavity formations. The density of capillaries might play the most important role in the microcirculation and the function of the blood-brain barrier. The fluorescein stain indicates the extent of the abnormally increased permeability of the capillaries. During the contrast-enhancement stage, the fluorescein stain is found not only in the contrast-enhacement region, but also in the surrounding zone around the contrast-enhancement region. There is an ischemic histological change, shown by the spongy appearance in this surrounding zone with the fluorescein stain. On a CT scan, this surrounding zone is seen as a normodensity area in most experimental models. These results indicate that, during the stage of the contrast-enhancement of cerebral infarction, a histologically evidenced ischemic area is detected not only as a contrast-enhancement region but also as a normodensity area around the contrast-enhancement region.

  6. Efficient multi-keV X-ray generation from high-contrast laser plasma interaction

    Directory of Open Access Journals (Sweden)

    Zhang Z.

    2013-11-01

    Full Text Available Kα line emission from Mo was experimentally and theoretically studied using clean, ultrahigh-intensity femtosecond laser pulses. The absolute yields of Kα x-rays at 17 keV from Mo were measured as a function of the laser pulse contrast ratio and irradiation intensity. Significantly enhanced Kα yields were obtained by employing high contrast ratio at optimum irradiance. Conversion efficiencies of 4.28 × 10−5/sr, the highest values obtained to date, was demonstrated with contrast ratios in the range of 10−10 to 10−11.

  7. Polarization-Independent Wideband High-Index-Contrast Grating Mirror

    DEFF Research Database (Denmark)

    Bekele, Dagmawi Alemayehu; Park, Gyeong Cheol; Malureanu, Radu

    2015-01-01

    Island-type two-dimensional high-index-contrast grating mirror based on a standard silicon-on-insulator wafer have been experimentally demonstrated. The measured spectra shows a bandwidth of ∼192 nm with a reflectivity over 99% as well as polarization independence. Numerical simulations show...... that the designed mirror has large tolerance to fabrication errors....

  8. Contrast-enhanced ultrasound (CEUS) in Crohn's disease: technique, image interpretation and clinical applications.

    Science.gov (United States)

    Ripollés, Tomás; Martínez-Pérez, María J; Blanc, Esther; Delgado, Fructuoso; Vizuete, José; Paredes, José M; Vilar, José

    2011-12-01

    BACKGROUND: Recent meta-analysis has demonstrated no significant differences in diagnostic accuracy among different imaging techniques (US, MRI and CT) in the evaluation of Crohn's disease (CD). High-resolution bowel ultrasound has emerged as an alternative imaging technique for the diagnosis and follow-up of patients with CD, being as accurate as CT and MR for detecting intramural and extramural extension of the disease. B-Mode US can evaluate the localization and length of the affected intestinal segments and allow identification of transmural complications, stenosis and intestinal obstruction. Doppler techniques are tools that visualize and quantify bowel vascularization. Contrast-enhanced ultrasound (CEUS) is a new technique that involves IV administration of an ultrasound contrast agent with real-time examination, providing an accurate depiction of the bowel wall microvascularization and the perienteric tissues. The introduction of imaging quantification techniques enables an objective quantitative measurement of the enhancement. METHOD AND RESULTS: The article reviews the technique, sonographic findings, advantages and limitations, and clinical applications of contrast-enhanced US in the evaluation of Cohn's disease. Current CEUS applications in CD are: CD activity assessment, evaluation of inflammatory masses, distinguishing phlegmons from abscesses, characterization of stenosis by differentiating fibrosis from inflammation, monitoring the efficacy of drug treatments and improving the detection of disease recurrence. CONCLUSION: CEUS is an emerging technique that is part of the entire sonographic evaluation, with a role in the diagnosis and follow-up of CD, thus improving therapy planning and monitoring of the efficacy of treatment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13244-011-0124-1) contains supplementary material, which is available to authorized users.

  9. Contrast medium enhancement of soft tissues and brain in CT examinations of dogs

    CERN Document Server

    Pavlicek, M

    2000-01-01

    CT is a x-ray based method which shows less contrast for soft tissue as has been known from radiography. Therefore, it is necessary to use intravenously administered iodine contrast media to detect and localize tumors, fistulas or other pathologic lesions. Usually contrast medium is administered manually which yields random patterns of media distribution due to varying application pressure during varying administration time, therefore enhancement of parenchymous organs could not be used to the optimum extent. The use of an automatic injection pump guarantees the necessary constancy during the examination procedure to undoubtedly detect pathologic enhancement of organs in the CT-image as known from human medicine. The standards which are expected of the injection pump and the contrast media are: a good contrast enhancement, a good accumulation in the examined organs, an accumulation, which lasts long enough during the diagnostic phase, and a rapid excretion without side effects. Because of the short scan time ...

  10. Novel nano-sized MR contrast agent mediates strong tumor contrast enhancement in an oncogene-driven breast cancer model.

    Directory of Open Access Journals (Sweden)

    Per-Olof Eriksson

    Full Text Available The current study was carried out to test the potential of a new nanomaterial (Spago Pix as a macromolecular magnetic MR contrast agent for tumor detection and to verify the presence of nanomaterial in tumor tissue. Spago Pix, synthesized by Spago Nanomedical AB, is a nanomaterial with a globular shape, an average hydrodynamic diameter of 5 nm, and a relaxivity (r1 of approximately 30 (mM Mn-1 s-1 (60 MHz. The material consists of an organophosphosilane hydrogel with strongly chelated manganese (II ions and a covalently attached PEG surface layer. In vivo MRI of the MMTV-PyMT breast cancer model was performed on a 3 T clinical scanner. Tissues were thereafter analyzed for manganese and silicon content using inductively coupled plasma-atomic emission spectroscopy (ICP-AES. The presence of nanomaterial in tumor and muscle tissue was assessed using an anti-PEG monoclonal antibody. MR imaging of tumor-bearing mice (n = 7 showed a contrast enhancement factor of 1.8 (tumor versus muscle at 30 minutes post-administration. Contrast was retained and further increased 2-4 hours after administration. ICP-AES and immunohistochemistry confirmed selective accumulation of nanomaterial in tumor tissue. A blood pharmacokinetics analysis showed that the concentration of Spago Pix gradually decreased over the first hour, which was in good agreement with the time frame in which the accumulation in tumor occurred. In summary, we demonstrate that Spago Pix selectively enhances MR tumor contrast in a clinically relevant animal model. Based on the generally higher vascular leakiness in malignant compared to benign tissue lesions, Spago Pix has the potential to significantly improve cancer diagnosis and characterization by MRI.

  11. Agreement and disagreement between contrast-enhanced magnetic resonance imaging and nuclear imaging for assessment of myocardial viability

    Energy Technology Data Exchange (ETDEWEB)

    Roes, Stijntje D.; Kaandorp, Theodorus A.M.; Westenberg, Jos J.M.; Lamb, Hildo J.; Roos, Albert de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Ajmone Marsan, Nina; Wall, Ernst E. van der; Bax, Jeroen J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Dibbets-Schneider, Petra; Stokkel, Marcel P. [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands)

    2009-04-15

    The purpose of this study was to compare contrast-enhanced MRI and nuclear imaging with {sup 99m}Tc-tetrofosmin and {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) single photon emission computed tomography (SPECT) for assessment of myocardial viability. Included in the study were 60 patients with severe ischaemic left ventricular (LV) dysfunction who underwent contrast-enhanced MRI, {sup 99m}Tc-tetrofosmin and {sup 18}F-FDG SPECT. Myocardial segments were assigned a wall motion score from 0 (normokinesia) to 4 (dyskinesia) and a scar score from 0 (no scar) to 4 (76-100% transmural extent). Furthermore, {sup 99m}Tc-tetrofosmin and {sup 18}F-FDG segmental tracer uptake was categorized from 0 (tracer activity >75%) to 3 (tracer activity <25%). Dysfunctional segments were classified into viability patterns on SPECT: normal perfusion/{sup 18}F-FDG uptake, perfusion/{sup 18}F-FDG mismatch, and mild or severe perfusion/{sup 18}F-FDG match. Minimal scar tissue was observed on contrast-enhanced MRI (scar score 0.4{+-}0.8) in segments with normal perfusion/{sup 18}F-FDG uptake, whereas extensive scar tissue (scar score 3.1{+-}1.0) was noted in segments with severe perfusion/{sup 18}F-FDG match (p < 0.001). High agreement (91%) for viability assessment between contrast-enhanced MRI and nuclear imaging was observed in segments without scar tissue on contrast-enhanced MRI as well as in segments with transmural scar tissue (83%). Of interest, disagreement was observed in segments with subendocardial scar tissue on contrast-enhanced MRI. Agreement between contrast-enhanced MRI and nuclear imaging for assessment of viability was high in segments without scar tissue and in segments with transmural scar tissue on contrast-enhanced MRI. However, evident disagreement was observed in segments with subendocardial scar tissue on contrast-enhanced MRI, illustrating that the nonenhanced epicardial rim can contain either normal or ischaemically jeopardized myocardium. (orig.)

  12. Intravenous contrast-enhanced cone beam computed tomography (IVCBCT of intrahepatic tumors and vessels

    Directory of Open Access Journals (Sweden)

    Cynthia L. Eccles, BSc

    2016-01-01

    Conclusions: Intravenous-CBCT may enhance the visibility of hepatic vessels and tumor in CBCT scans obtained during breath hold. Optimization of IV contrast timing and reduction of artifacts to improve tumor visualization warrant further investigation.

  13. Biliary complications following orthotopic liver transplantation: May contrast-enhanced MR Cholangiography provide additional information?

    Directory of Open Access Journals (Sweden)

    Piero Boraschi

    2016-01-01

    Conclusions: Contrast-enhanced T1-weighted MR Cholangiography may improve the level of diagnostic confidence provided by conventional T2-weighted MR Cholangiography in the evaluation of biliary complications after orthotopic liver transplantation.

  14. Contrast-enhanced ultrasonographic findings in three dogs with lung lobe torsion.

    Science.gov (United States)

    Caivano, Domenico; Birettoni, Francesco; Bufalari, Antonello; De Monte, Valentina; Angeli, Giovanni; Giorgi, Maria Elena; Patata, Valentina; Porciello, Francesco

    2016-03-01

    Lung lobe torsion is rare but life-threatening condition in the dog. Thoracic radiographs and conventional ultrasonography cannot be conclusive for the diagnosis, and computed tomography is useful but is limited by cost and availability. This report describes the findings of contrast-enhanced ultrasonography in 3 dogs with lung lobe torsion. Contrast-enhanced ultrasonography showed the absence or reduction of pulmonary vascularization secondary to twisting of the lung lobe around its bronchovascular pedicle in all three dogs. Moreover, contrast-enhanced ultrasonography distinguished partial pulmonary atelectasis from a lung lobe torsion. These preliminary results suggest that contrast-enhanced ultrasonography can improve the accuracy of conventional ultrasonography for detection of pulmonary blood flow compromise in dogs with lung lobe torsion.

  15. Diagnosis of Spinal Lesions Using Heuristic and Pharmacokinetic Parameters Measured by Dynamic Contrast-Enhanced MRI.

    Science.gov (United States)

    Lang, Ning; Yuan, Huishu; Yu, Hon J; Su, Min-Ying

    2017-07-01

    This study aimed to evaluate the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in differentiation of four spinal lesions by using heuristic and pharmacokinetic parameters analyzed from DCE signal intensity time course. DCE-MRI of 62 subjects with confirmed myeloma (n = 9), metastatic cancer (n = 22), lymphoma (n = 7), and inflammatory tuberculosis (TB) (n = 24) in the spine were analyzed retrospectively. The region of interest was placed on strongly enhanced tissues. The DCE time course was categorized as the "wash-out," "plateau," or "persistent enhancement" pattern. The maximum enhancement, steepest wash-in enhancement, and wash-out slope using the signal intensity at 67 seconds after contrast injection as reference were measured. The Tofts 2-compartmental pharmacokinetic model was applied to obtain K trans and k ep . Pearson correlation between heuristic and pharmacokinetic parameters was evaluated, and receiver operating characteristic curve analysis was performed for pairwise group differentiation. The mean wash-out slope was -22% ± 10% for myeloma, 1% ± 0.4% for metastatic cancer, 3% ± 3% for lymphoma, and 7% ± 10% for TB, and it could significantly distinguish myeloma from metastasis (area under the curve [AUC] = 0.884), lymphoma (AUC = 1.0), and TB (AUC = 1.0) with P = .001, and distinguish metastasis from TB (AUC = 0.741) with P = .005. The k ep and wash-out slope were highly correlated (r = 0.92), and they showed a similar diagnostic performance. The K trans was significantly correlated with the maximum enhancement (r = 0.71) and the steepest wash-in enhancement (r = 0.85), but they had inferior diagnostic performance compared to the wash-out slope. DCE-MRI may provide additional diagnostic information, and a simple wash-out slope had the best diagnostic performance. The heuristic and pharmacokinetic parameters were highly correlated

  16. The V-SHARK high contrast imager at LBT

    Science.gov (United States)

    Pedichini, F.; Ambrosino, F.; Centrone, M.; Farinato, J.; Li Causi, G.; Pinna, E.; Puglisi, A.; Stangalini, M.; Testa, V.

    2016-08-01

    In the framework of the SHARK project the visible channel is a novel instrument synergic to the NIR channel and exploiting the performances of the LBT XAO at visible wavelengths. The status of the project is presented together with the design study of this innovative instrument optimized for high contrast imaging by means of high frame rate. Its expected results will be presented comparing the simulations with the real data of the "Forerunner" experiment taken at 630nm.

  17. Study of quality perception in medical images based on comparison of contrast enhancement techniques in mammographic images

    Science.gov (United States)

    Matheus, B.; Verçosa, L. B.; Barufaldi, B.; Schiabel, H.

    2014-03-01

    With the absolute prevalence of digital images in mammography several new tools became available for radiologist; such as CAD schemes, digital zoom and contrast alteration. This work focuses in contrast variation and how the radiologist reacts to these changes when asked to evaluated image quality. Three contrast enhancing techniques were used in this study: conventional equalization, CCB Correction [1] - a digitization correction - and value subtraction. A set of 100 images was used in tests from some available online mammographic databases. The tests consisted of the presentation of all four versions of an image (original plus the three contrast enhanced images) to the specialist, requested to rank each one from the best up to worst quality for diagnosis. Analysis of results has demonstrated that CCB Correction [1] produced better images in almost all cases. Equalization, which mathematically produces a better contrast, was considered the worst for mammography image quality enhancement in the majority of cases (69.7%). The value subtraction procedure produced images considered better than the original in 84% of cases. Tests indicate that, for the radiologist's perception, it seems more important to guaranty full visualization of nuances than a high contrast image. Another result observed is that the "ideal" scanner curve does not yield the best result for a mammographic image. The important contrast range is the middle of the histogram, where nodules and masses need to be seen and clearly distinguished.

  18. The MRI Contrast Agent Gadoteridol Enhances Distribution of rAAV1 in the Rat Hippocampus

    OpenAIRE

    Hullinger, Rikki; Ugalde, Jeanet; Purón-Sierra, Liliana; Osting, Sue; Burger, Corinna

    2013-01-01

    Contrast agents are commonly used in combination with magnetic resonance imaging (MRI) to monitor the distribution of molecules in the brain. Recent experiments conducted in our laboratory have shown that co-infusion of recombinant Adeno-associated virus serotype 5 (rAAV5) and the MRI contrast agent gadoteridol (Gd) enhances vector transduction of in the rat striatum. The goal of this study was to determine whether gadoteridol may also be used as a tool to enhance transduction efficiency of r...

  19. The role of contrast-enhanced ultrasonography in image-guided liver ablations

    Energy Technology Data Exchange (ETDEWEB)

    Pescatori, Lorenzo Carlo [Postgraduate School in Radiodiagnostics, University Studi di Milano, Milan (Italy); Sconfienza, Luca Maria; Mauri, Giovanni [Radiology Unit, Policlinico San Donato Research Hospital, Milan (Italy)

    2016-01-15

    We read with great interest the paper by Kim et al. entitled “Local ablation therapy with contrast enhanced ultrasonography for hepatocellular carcinoma: a practical review,” recently published in Ultrasonography. We think that contrast-enhanced ultrasonography (CEUS), together with the development of reliable navigation systems, is likely to represent one of the most important advances in image-guided ablations in recent years. Thus, we offer some considerations on the topic.

  20. Comparison of Background Parenchymal Enhancement at Contrast-enhanced Spectral Mammography and Breast MR Imaging.

    Science.gov (United States)

    Sogani, Julie; Morris, Elizabeth A; Kaplan, Jennifer B; D'Alessio, Donna; Goldman, Debra; Moskowitz, Chaya S; Jochelson, Maxine S

    2017-01-01

    Purpose To assess the extent of background parenchymal enhancement (BPE) at contrast material-enhanced (CE) spectral mammography and breast magnetic resonance (MR) imaging, to evaluate interreader agreement in BPE assessment, and to examine the relationships between clinical factors and BPE. Materials and Methods This was a retrospective, institutional review board-approved, HIPAA-compliant study. Two hundred seventy-eight women from 25 to 76 years of age with increased breast cancer risk who underwent CE spectral mammography and MR imaging for screening or staging from 2010 through 2014 were included. Three readers independently rated BPE on CE spectral mammographic and MR images with the ordinal scale: minimal, mild, moderate, or marked. To assess pairwise agreement between BPE levels on CE spectral mammographic and MR images and among readers, weighted κ coefficients with quadratic weights were calculated. For overall agreement, mean κ values and bootstrapped 95% confidence intervals were calculated. The univariate and multivariate associations between BPE and clinical factors were examined by using generalized estimating equations separately for CE spectral mammography and MR imaging. Results Most women had minimal or mild BPE at both CE spectral mammography (68%-76%) and MR imaging (69%-76%). Between CE spectral mammography and MR imaging, the intrareader agreement ranged from moderate to substantial (κ = 0.55-0.67). Overall agreement on BPE levels between CE spectral mammography and MR imaging and among readers was substantial (κ = 0.66; 95% confidence interval: 0.61, 0.70). With both modalities, BPE demonstrated significant association with menopausal status, prior breast radiation therapy, hormonal treatment, breast density on CE spectral mammographic images, and amount of fibroglandular tissue on MR images (P < .001 for all). Conclusion There was substantial agreement between readers for BPE detected on CE spectral mammographic and MR images. © RSNA

  1. Counter-propagating wave interaction for contrast-enhanced ultrasound imaging

    NARCIS (Netherlands)

    G. Renaud (G.); J.G. Bosch (Hans); E.J.G. Sijbrands (Eric); V. Shamdasani (V.); R. Entrekin (R.); N. de Jong (Nico); A.F.W. van der Steen (Ton)

    2012-01-01

    textabstractMost techniques for contrast-enhanced ultrasound imaging require linear propagation to detect nonlinear scattering of contrast agent microbubbles. Waveform distortion due to nonlinear propagation impairs their ability to distinguish microbubbles from tissue. As a result, tissue can be

  2. Medical Image Visual Appearance Improvement Using Bihistogram Bezier Curve Contrast Enhancement: Data from the Osteoarthritis Initiative

    Science.gov (United States)

    Gan, Hong-Seng; Swee, Tan Tian; Abdul Karim, Ahmad Helmy; Sayuti, Khairil Amir; Abdul Kadir, Mohammed Rafiq; Tham, Weng-Kit; Wong, Liang-Xuan; Chaudhary, Kashif T.; Yupapin, Preecha P.

    2014-01-01

    Well-defined image can assist user to identify region of interest during segmentation. However, complex medical image is usually characterized by poor tissue contrast and low background luminance. The contrast improvement can lift image visual quality, but the fundamental contrast enhancement methods often overlook the sudden jump problem. In this work, the proposed bihistogram Bezier curve contrast enhancement introduces the concept of “adequate contrast enhancement” to overcome sudden jump problem in knee magnetic resonance image. Since every image produces its own intensity distribution, the adequate contrast enhancement checks on the image's maximum intensity distortion and uses intensity discrepancy reduction to generate Bezier transform curve. The proposed method improves tissue contrast and preserves pertinent knee features without compromising natural image appearance. Besides, statistical results from Fisher's Least Significant Difference test and the Duncan test have consistently indicated that the proposed method outperforms fundamental contrast enhancement methods to exalt image visual quality. As the study is limited to relatively small image database, future works will include a larger dataset with osteoarthritic images to assess the clinical effectiveness of the proposed method to facilitate the image inspection. PMID:24977191

  3. Medical Image Visual Appearance Improvement Using Bihistogram Bezier Curve Contrast Enhancement: Data from the Osteoarthritis Initiative

    Directory of Open Access Journals (Sweden)

    Hong-Seng Gan

    2014-01-01

    Full Text Available Well-defined image can assist user to identify region of interest during segmentation. However, complex medical image is usually characterized by poor tissue contrast and low background luminance. The contrast improvement can lift image visual quality, but the fundamental contrast enhancement methods often overlook the sudden jump problem. In this work, the proposed bihistogram Bezier curve contrast enhancement introduces the concept of “adequate contrast enhancement” to overcome sudden jump problem in knee magnetic resonance image. Since every image produces its own intensity distribution, the adequate contrast enhancement checks on the image’s maximum intensity distortion and uses intensity discrepancy reduction to generate Bezier transform curve. The proposed method improves tissue contrast and preserves pertinent knee features without compromising natural image appearance. Besides, statistical results from Fisher’s Least Significant Difference test and the Duncan test have consistently indicated that the proposed method outperforms fundamental contrast enhancement methods to exalt image visual quality. As the study is limited to relatively small image database, future works will include a larger dataset with osteoarthritic images to assess the clinical effectiveness of the proposed method to facilitate the image inspection.

  4. Saltiness enhancement by taste contrast in bread prepared with encapsulated salt

    NARCIS (Netherlands)

    Noort, M.W.J.; Bult, J.H.F.; Stieger, M.

    2012-01-01

    In this study, we investigate a technological approach to reduce the sodium content of bread whilst retaining its sensory profile by creating taste contrast using encapsulated salt. We demonstrate that sensory contrast in bread induced by encapsulated salt can enhance saltiness and allows for a salt

  5. Modeling Dynamic Contrast-Enhanced MRI Data with a Constrained Local AIF

    DEFF Research Database (Denmark)

    Duan, Chong; Kallehauge, Jesper F.; Pérez-Torres, Carlos J

    2017-01-01

    PURPOSE: This study aims to develop a constrained local arterial input function (cL-AIF) to improve quantitative analysis of dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) data by accounting for the contrast-agent bolus amplitude error in the voxel-specific AIF. PROCEDURES...

  6. Arterial input function calculation in dynamic contrast-enhanced MRI: an in vivo validation study using co-registered contrast-enhanced ultrasound imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mehrabian, Hatef; Chandrana, Chaitanya; Pang, Ian; Chopra, Rajiv; Martel, Anne L. [University of Toronto, Department of Medical Biophysics, Sunnybrook Research Institute, Toronto, ON (Canada)

    2012-08-15

    Developing a method of separating intravascular contrast agent concentration to measure the arterial input function (AIF) in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of tumours, and validating its performance in phantom and in vivo experiments. A tissue-mimicking phantom was constructed to model leaky tumour vasculature and DCE-MR images of this phantom were acquired. An in vivo study was performed using tumour-bearing rabbits. Co-registered DCE-MRI and contrast-enhanced ultrasound (CEUS) images were acquired. An independent component analysis (ICA)-based method was developed to separate the intravascular component from DCE-MRI. Results were validated by comparing the time-intensity curves with the actual phantom and in vivo curves. Phantom study: the AIF extracted using ICA correlated well with the true intravascular curve. In vivo study: the AIFs extracted from DCE-MRI using ICA were very close to the true AIF. Intravascular component images were very similar to the CEUS images. The contrast onset times and initial wash-in slope of the ICA-derived AIF showed good agreement with the CEUS curves. ICA has the potential to separate the intravascular component from DCE-MRI. This could eliminate the requirement for contrast medium uptake measurements in a major artery and potentially result in more accurate pharmacokinetic parameters. (orig.)

  7. Highly magnetic iron carbide nanoparticles as effective T(2) contrast agents.

    Science.gov (United States)

    Huang, Guoming; Hu, Juan; Zhang, Hui; Zhou, Zijian; Chi, Xiaoqin; Gao, Jinhao

    2014-01-21

    This paper reports that iron carbide nanoparticles with high air-stability and strong saturation magnetization can serve as effective T2 contrast agents for magnetic resonance imaging. Fe5C2 nanoparticles (~20 nm in diameter) exhibit strong contrast enhancement with an r2 value of 283.2 mM(-1) S(-1), which is about twice as high as that of spherical Fe3O4 nanoparticles (~140.9 mM(-1) S(-1)). In vivo experiments demonstrate that Fe5C2 nanoparticles are able to produce much more significant MRI contrast enhancement than conventional Fe3O4 nanoparticles in living subjects, which holds great promise in biomedical applications.

  8. Combined dynamic contrast-enhancement and serial 3D-subtraction analysis in magnetic resonance imaging of osteoid osteomas

    Energy Technology Data Exchange (ETDEWEB)

    Kalle, T. von; Winkler, P. [Klinikum Stuttgart Olgahospital, Department of Paediatric Radiology, Stuttgart (Germany); Langendoerfer, M.; Fernandez, F.F. [Klinikum Stuttgart Olgahospital, Department of Paediatric Orthopaedics, Stuttgart (Germany)

    2009-10-15

    The purpose of this study was to retrospectively correlate the results of dynamic contrast-enhanced magnetic resonance imaging (MRI) with histological and clinical diagnoses in patients with osteoid osteomas. Fifty-four patients with the MR diagnosis of osteoid osteoma were studied. MRI (1.5 Tesla) consisted of thin-section STIR sequences, dynamic 3D T1 gradient echo sequences during application of contrast material, and high-resolution postcontrast T1 spin echo sequences with fat saturation (maximum voxel size 0.6 x 0.6 x 3.0 mm). Evaluation was focused on serial image subtraction during the early phase after contrast injection and on time-intensity curves. The surrounding edema was helpful in finding the nidus in each lesion. In 49 of 54 patients (90.7%), the diagnosis of osteoid osteoma was certain or highly probable (sensitivity 1.0, positive predictive value 0.91). A total of 38 of 54 osteoid osteomas were histologically proven. Five MRI diagnoses were regarded as false positives. A similar proportion has been reported for computed tomography. Tailored high-resolution MR examinations with dynamic contrast enhancement can reliably diagnose osteoid osteomas and exactly localize the nidus without radiation exposure. We propose a stepwise approach with STIR sequences, dynamic contrast-enhanced scanning, and high-resolution postcontrast T1 spin echo sequences with fat saturation. (orig.)

  9. Contrast-enhanced MR imaging of the endolymphatic sac in patients with sudden hearing loss

    Energy Technology Data Exchange (ETDEWEB)

    Naganawa, Shinji; Koshikawa, Tokiko; Fukatsu, Hiroshi; Ishigaki, Takeo [Department of Radiology, Nagoya University School of Medicine (Japan); Nakashima, Tsutomu [Department of Otolayngology, Nagoya University School of Medicine (Japan); Ichinose, Nobuyasu [Toshiba Nasu Operations, Tochigi (Japan)

    2002-05-01

    Our objective was to evaluate the frequency of contrast enhancement of the endolymphatic sac in patients with sudden hearing loss. Forty consecutive patients with sudden sensorineural hearing loss (20 males and 20 females; age range 11-82 years), 40 age-matched control subjects, and 5 patients with Meniere's disease were examined using the same imaging protocol on a 1.5-T MR system. Pre- and post-contrast-enhanced T1-weighted 3D spoiled gradient-echo sequence (3D SPGR; TR/TE=23/10 ms, no. of excitations=1, flip angle=30 ) images were obtained using a voxel size of 0.6 x 0.7 x 0.8 mm{sup 3}. Contrast enhancement in the area of the endolymphatic sac was assessed by two radiologists, and the frequency of contrast enhancement was compared between the three study groups. Enhancement of the ipsilateral endolymphatic sac was observed in 30 of the 40 patients with sudden hearing loss (75%). Twenty of these 30 patients also showed enhancement on the contralateral side, and 1 patient showed enhancement only on the contralateral side. Only 1 of the 5 patients with Meniere's disease showed enhancement. Nine of the 40 control subjects (22.5%) showed enhancement (bilateral enhancement in 5 subjects, unilateral in 4). The frequency of enhancement in patients with sudden hearing loss was significantly higher than that in control subjects (P<0.0001) or patients with Meniere's disease (P<0.05). The frequency of contrast enhancement of the endolymphatic sac is significantly increased in patients with sudden hearing loss, but further study is necessary to clarify the relationship between this finding and the pathophysiology of sudden hearing loss. (orig.)

  10. Contrast-enhanced optical coherence tomography with picomolar sensitivity for functional in vivo imaging

    Science.gov (United States)

    Liba, Orly; Sorelle, Elliott D.; Sen, Debasish; de La Zerda, Adam

    2016-03-01

    Optical Coherence Tomography (OCT) enables real-time imaging of living tissues at cell-scale resolution over millimeters in three dimensions. Despite these advantages, functional biological studies with OCT have been limited by a lack of exogenous contrast agents that can be distinguished from tissue. Here we report an approach to functional OCT imaging that implements custom algorithms to spectrally identify unique contrast agents: large gold nanorods (LGNRs). LGNRs exhibit 110-fold greater spectral signal per particle than conventional GNRs, which enables detection of individual LGNRs in water and concentrations as low as 250 pM in the circulation of living mice. This translates to ~40 particles per imaging voxel in vivo. Unlike previous implementations of OCT spectral detection, the methods described herein adaptively compensate for depth and processing artifacts on a per sample basis. Collectively, these methods enable high-quality noninvasive contrast-enhanced imaging of OCT in living subjects, including detection of tumor microvasculature at twice the depth achievable with conventional OCT. Additionally, multiplexed detection of spectrally-distinct LGNRs was demonstrated to observe discrete patterns of lymphatic drainage and identify individual lymphangions and lymphatic valve functional states. These capabilities provide a powerful platform for molecular imaging and characterization of tissue noninvasively at cellular resolution, called MOZART.

  11. Contrast-enhanced spectral mammography: comparison with conventional mammography and histopathology in 152 women.

    Science.gov (United States)

    Luczyńska, Elzbieta; Heinze-Paluchowska, Sylwia; Dyczek, Sonia; Blecharz, Pawel; Rys, Janusz; Reinfuss, Marian

    2014-01-01

    The goal of the study was to compare conventional mammography (MG) and contrast-enhanced spectral mammography (CESM) in preoperative women. The study was approved by the local Ethics Committee and all participants provided informed consent. The study included 152 consecutive patients with 173 breast lesions diagnosed on MG or CESM. All MG examinations and consults were conducted in one oncology centre. Non-ionic contrast agent, at a total dose of 1.5 mL/kg body weight, was injected intravenous. Subsequently, CESM exams were performed with a mammography device, allowing dual-energy acquisitions. The entire procedure was done within the oncology centre. Images from low and high energy exposures were processed together and the combination provided an "iodine" image which outlined contrast up-take in the breast. MG detected 157 lesions in 150 patients, including 92 infiltrating cancers, 12 non-infiltrating cancers, and 53 benign lesions. CESM detected 149 lesions in 128 patients, including 101 infiltrating cancers, 13 non-infiltrating cancers, and 35 benign lesions. CESM sensitivity was 100% (vs. 91% for MG), specificity was 41% (vs. 15% for MG), area under the receiver operating characteristic curve was 0.86 (vs. 0.67 for MG), and accuracy was 80% (vs. 65% for MG) for the diagnosis of breast cancer. Both MG and CESM overestimated lesion sizes compared to histopathology (p < 0.001). CESM may provide higher sensitivity for breast cancer detection and greater diagnostic accuracy than conventional mammography.

  12. Contrast-Enhanced Spectral Mammography: Comparison with Conventional Mammography and Histopathology in 152 Women

    Energy Technology Data Exchange (ETDEWEB)

    Luczyńska, Elzbieta; Heinze-Paluchowska, Sylwia; Dyczek, Sonia [Department of Radiology, Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow 31-115 (Poland); Blecharz, Pawel [Department of Gynecologic Oncology, Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow 31-115 (Poland); Rys, Janusz [Department of Tumour Pathology, Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow 31-115 (Poland); Reinfuss, Marian [Department of Radiotherapy, Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow 31-115 (Poland)

    2014-07-01

    The goal of the study was to compare conventional mammography (MG) and contrast-enhanced spectral mammography (CESM) in preoperative women. The study was approved by the local Ethics Committee and all participants provided informed consent. The study included 152 consecutive patients with 173 breast lesions diagnosed on MG or CESM. All MG examinations and consults were conducted in one oncology centre. Non-ionic contrast agent, at a total dose of 1.5 mL/kg body weight, was injected intravenous. Subsequently, CESM exams were performed with a mammography device, allowing dual-energy acquisitions. The entire procedure was done within the oncology centre. Images from low and high energy exposures were processed together and the combination provided an 'iodine' image which outlined contrast up-take in the breast. MG detected 157 lesions in 150 patients, including 92 infiltrating cancers, 12 non-infiltrating cancers, and 53 benign lesions. CESM detected 149 lesions in 128 patients, including 101 infiltrating cancers, 13 non-infiltrating cancers, and 35 benign lesions. CESM sensitivity was 100% (vs. 91% for MG), specificity was 41% (vs. 15% for MG), area under the receiver operating characteristic curve was 0.86 (vs. 0.67 for MG), and accuracy was 80% (vs. 65% for MG) for the diagnosis of breast cancer. Both MG and CESM overestimated lesion sizes compared to histopathology (p < 0.001). CESM may provide higher sensitivity for breast cancer detection and greater diagnostic accuracy than conventional mammography.

  13. MR imaging of double-contrast enhanced porcine myocardial infarction. Correlation with microdialysis

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, S. [Dept. of Diagnostic Radiology, Univ. Hospital, Uppsala (Sweden); Wikstroem, M. [Dept. of Diagnostic Radiology, Univ. Hospital, Uppsala (Sweden); Ericsson, A. [Dept. of Diagnostic Radiology, Univ. Hospital, Uppsala (Sweden); Wikstroem, G. [Dept. of Internal Medicine, Univ. Hospital, Uppsala (Sweden); Waldenstroem, A. [Dept. of Internal Medicine, Univ. Hospital, Uppsala (Sweden); Oeksendal, A. [Nycomed Imaging AS, Oslo (Norway); Hemmingsson, A. [Dept. of Diagnostic Radiology, Univ. Hospital, Uppsala (Sweden)

    1995-07-01

    MR imaging was performed to investigate whether Gd-DTPA-BMA-induced contrast enhancement of myocardial infarction is counteracted by Dy-DTPA-BMA. Myocardial infarction was induced in 5 pigs. Microdialysate probes were inserted in ischemic and nonischemic myocardium. Gd-DTPA-BMA (0.3 mmol/kg b.w.) and Dy-DTPA-BMA (1.0 mmol/kg b.w.) were administered i.v. 4 hours post occlusion. The microdialysate was collected every 10 min and measured for Gd and Dy using inductively coupled plasma atomic emission spectrometry. The pigs were sacrificed 2 hours after administration of contrast media. The concentration of both contrast agents was 3 times higher in infarcted myocardium than in nonischemic myocardium. The infarctions displayed high signal intensity in spin-echo sequences ex vivo. This lack of detectable susceptibility effects from Dy may be caused by loss of cell membrane integrity in infarcted tissue as shown by our microdialysate and biopsy data. (orig.).

  14. Incidental focal solid liver lesions: diagnostic performance of contrast-enhanced ultrasound and MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Soussan, Michael [Hopital Beaujon, Department of Radiology, Assistance Publique des Hopitaux de Paris, APHP, Clichy (France); Aube, Christophe [CHU Angers, Department of Radiology, Angers (France); Laboratoire HIFIH, Angers (France); Bahrami, Stephane [Universite Paris-Dauphine, Department of Medical Statistics, Assistance Publique des Hopitaux de Paris, APHP, Paris (France); Boursier, Jerome [CHU Angers, Department of Hepatogastroenterology and Laboratoire HIFIH, Angers (France); Valla, Dominique Charles [Universite Paris-7 Denis Diderot, Paris (France); INSERM Centre de recherche Biomedicale Bichat Beaujon, Paris (France); Hopital Beaujon, Department of Hepatology, Assistance Publique des Hopitaux de Paris, APHP, Clichy (France); Vilgrain, Valerie [Hopital Beaujon, Department of Radiology, Assistance Publique des Hopitaux de Paris, APHP, Clichy (France); Universite Paris-7 Denis Diderot, Paris (France); INSERM Centre de recherche Biomedicale Bichat Beaujon, Paris (France)

    2010-07-15

    To prospectively assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) and MR imaging in incidental solid focal liver lesions not characterised on ultrasound. Forty-seven patients with 50 lesions underwent MR imaging and CEUS: 24 focal nodular hyperplasias (FNH), 11 adenomas, 10 haemangiomas, 1 focal fatty change and 4 malignant lesions were identified. Two experienced radiologists randomly reviewed contrast-enhanced MR imaging and CEUS data, and provided the most likely diagnosis. Sensitivity (Se), specificity (Sp), likelihood ratios (LR) and kappa value were calculated. A histotype diagnosis was obtained in 66-52% with MR imaging and 52-53% with CEUS, respectively, for both readers. Se, Sp and LR for haemangioma were 100-100, 100-100 and 78-78 with MR imaging and 89-89, 100-100 and 68-70 with CEUS; for FNH with MR imaging they were 88-63, 96-100 and 23-34 and 74-67, 88-96 and 6-17 with CEUS. If the diagnosis of haemangioma was uncertain with CEUS, MR imaging always confirmed the diagnosis. If the diagnosis of FNH was uncertain with either CEUS or MR imaging, the other imaging technique confirmed the diagnosis in approximately half the cases. Both CEUS and MR imaging have a high diagnostic performance in incidental focal liver lesions and are complementary when diagnosis is uncertain. (orig.)

  15. Evaluating noise reduction techniques while considering anatomical noise in dual-energy contrast-enhanced mammography.

    Science.gov (United States)

    Allec, Nicholas; Abbaszadeh, Shiva; Scott, Chris C; Karim, Karim S; Lewin, John M

    2013-05-01

    The authors describe modifications to previously developed cascaded systems analysis to include the anatomical noise in evaluation of dual-energy noise reduction techniques. Previous models have ignored the anatomical noise in theoretical analysis of noise reduction techniques. The inclusion of anatomical noise leads to more accurate estimation of potential noise reduction improvements and optimization. The model is applied to dual-energy contrast-enhanced mammography. The effect of linear noise reduction filters on the anatomical noise is taken into account using cascaded systems analysis. The noise model is included in the ideal observer detectability for performance evaluation of the noise reduction techniques. Dual-energy image noise with and without including the effect of anatomical noise in noise reduction technique analysis is reported. The theoretical model is compared with clinical images from a previous dual-energy contrast enhanced mammography clinical study and good agreement is observed. The results suggest that the inclusion of anatomical noise in the evaluation and comparison of noise reduction techniques is highly warranted for more accurate analysis. This work establishes a useful extension to dual-energy cascaded systems analysis for maximizing image quality using noise reduction techniques. The extension includes the effect of linear image filtering, such as that used for noise reduction, on anatomical noise. The results suggest that the inclusion of anatomical noise in the evaluation of noise reduction techniques can lead to more accurate optimization, noise, and performance estimations.

  16. Moderate contrast in the evaluation of paintings is liked more but remembered less than high contrast

    National Research Council Canada - National Science Library

    Dijkstra, Katinka; van Dongen, N.N.N

    2017-01-01

    .... The results indicated that for art appreciation, a moderate increase in contrast resulted in the highest appreciation for paintings whereas recognition memory was better for paintings with a higher increase in contrast...

  17. Contrast-enhanced dual-energy mammography: a promising new imaging tool in breast cancer detection.

    Science.gov (United States)

    Lalji, Ulrich; Lobbes, Marc

    2014-05-01

    Contrast-enhanced dual-energy mammography (CEDM) is a promising new breast imaging tool for breast cancer detection. In CEDM, an iodine-based contrast agent is intravenously administered and subsequently, dual-energy mammography is performed. This results in a set of images containing both a regular mammogram and an image that contains contrast enhancement information. Preliminary studies have indicated that CEDM is superior to conventional mammography and might even match the diagnostic performance of breast MRI. In this review, the imaging technique, protocol and patient handling of CEDM is presented. Furthermore, an overview of current results on CEDM and potential future indications are outlined.

  18. Development of microbubble contrast agents for high frequency ultrasound microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Se Jung; Kim, Eun A; Park, Sung Hoon; Lee, Hye Jin; Jun, Hong Young; Byun, Seung Jae; Yoon, Kwon Ha [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

    2007-05-15

    To develop optimal microbubble contrast agents (MBCAs) for performing ultrasound microscopy when examining small animals. We prepared three types of MBCAs. First, a mixture of three parts of 40% dextran and one part of 5% human serum albumin were sonicated with perfluorocarbon (PFC) (MB{sub 1}-D40A5P). Second, three parts of 40% dextran and one part of 1% human serum albumin were sonicated with PFC (MB{sub 2}-D40A1P). Third, all parts of 1% bovine serum albumin were sonicated with PFC (MB{sub 3}-A1P). We measured the microbubbles' sizes and concentrations with using image analysis software. The acoustic properties of the microbubbles were assessed both in vitro and in vivo. The majority of the MB{sub 1}-D40A5Ps had a diameter of 2-5 {mu} m, the mean diameter of the MB{sub 2}-D40A1Ps was 2.5 {mu} m, and the mean diameter of the MB{sub 3}-A1Ps was less than 2.0 {mu} m. Among the microbubbles, the MB{sub 1}-D40A5Ps and MB{sub 2}-D40A1Ps showed increased echogenicity in the abdominal vessels, but the duration of their contrast effect was less than 30 sec. On the contrary, the MB3-A1Ps exhibited strong enhancement in the vessels and their duration was greater than 120 sec. A microbubble contrast agent consisting of all parts of 1% serum albumin sonicated with PFC is an effective contrast agent for ultrasound microscopy.

  19. Dynamic contrast-enhanced magnetic resonance imaging of the wrist in early arthritis

    Directory of Open Access Journals (Sweden)

    M.A. Cimmino

    2011-09-01

    Full Text Available Objectives: MRI has been proposed as the imaging method of choice to evaluate the long-term outcome in patients with early arthritis. The role of dynamic MRI, performed at presentation, in predicting the outcome of patients with early arthritis has been addressed in the present study. Methods: 39 patients with early arthritis, involving at least one wrist, were studied with clinical visits and laboratory investigations, every 3 months. Dynamic MRI was performed with a low-field (0.2T, extremity-dedicated machine (Artoscan, Esaote, Genova, Italy equipped with a permanent magnet and with a dedicated hand and wrist coil. During the intravenous injection of Gd-DTPA, twenty consecutive fast images of 3 slices of the wrist were acquired. The synovial contrast enhancement ratio was calculated both as rate of early enhancement (REE per second during the first 55” and as relative enhancement (RE at t seconds. Results: In our cohort of patients, REE and RE were significantly lower than those observed in a historical cohort of 36 patients with active rheumatoid arthritis. In univariate analysis, low RE predicted complete remission of arthritis. In multivariate analysis, fulfillment of RA criteria during follow-up was predicted by high RE. The need for immunosuppressive treatment at the end of follow-up was predicted by both low RE and high REE. Conclusions: Dynamic MRI may be used to predict several outcomes of early arthritis involving the wrist

  20. Feasibility of Left Ventricular Global Longitudinal Strain Measurements from Contrast-Enhanced Echocardiographic Images.

    Science.gov (United States)

    Medvedofsky, Diego; Lang, Roberto M; Kruse, Eric; Guile, Brittney; Weinert, Lynn; Ciszek, Boguslawa; Jacobson, Zachary; Negron, Jacqueline; Volpato, Valentina; Prado, Aldo; Patel, Amit R; Mor-Avi, Victor

    2017-11-23

    Although left ventricular global longitudinal strain (GLS) is an index of systolic function recommended by the guidelines, poor image quality may hamper strain measurements. While contrast agents are commonly used to improve endocardial visualization, no commercial speckle-tracking software is able to measure strain in contrast-enhanced images. This study aimed to test the accuracy of speckle-tracking software when applied to contrast-enhanced images in patients with suboptimal image quality. We studied patients with a wide range of GLS values who underwent transthoracic echocardiography. Protocol 1 included 44 patients whose images justified use of contrast but still allowed noncontrast speckle-tracking echocardiography (STE), which was judged as accurate and used as a reference. Protocol 2 included 20 patients with poor image quality that precluded noncontrast STE; cardiac magnetic resonance- (CMR-) derived strain was used as the reference instead. Half the manufacturer recommended dose of a commercial contrast agent (Definity/Optison/Lumason) was used to provide partial contrast enhancement. Higher than normal mechanical indices (0.6-0.7) and lowest frequency range for maximal penetration settings were used for imaging. GLS was measured (Epsilon) with and without contrast-enhanced images and by CMR-derived feature tracking (TomTec). Comparisons included linear regression and Bland-Altman analyses. The contrast STE analysis failed in 4/64 patients (6%). Manual corrections were needed to optimize tracking with contrast in all patients. GLS measurements were in good agreement between contrast and noncontrast images (r = 0.85; mean GLS in the contrast images, -12.9% ± 4.7%; bias, 0.34% ± 2.4%). Good agreement was also noted between contrast STE- and CMR-derived strain (r = 0.83; mean, GLS -13.5% ± 4.0%; bias, 0.72% ± 2.5%). We found that GLS measurements from contrast-enhanced images are feasible and accurate in most patients, even in those with poor

  1. Pelvic congestion syndrome initially detected by contrast enhanced F 18 FDG PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Weung; Kim, Myoung Hyoung; Kim, Woo Hyoung; Kim, Chang Guhn [Wonkwang Univ. School of Medicine, Iksan (Korea, Republic of)

    2012-03-15

    Pelvic congestion syndrome (PCS) is said to occur as a result of retrograde flow in an incompetent ovarian vein. Ovarian vein incompetence is seen in approximately 10% of women, and up to 60% with this abnormality can develop PCS. The etiology of PCS is poorly understood and is likely to be multifactorial. Absence of ovarian vein valves is an important factor in its development. The causes of ovarian varicoceles are multifactorial, involving both mechanical and hormonal factors. Dilatation of the ovarian veins can result in vascular incompetence and retrograde blood flow. On either CT or magnetic resonance (MR) imaging studies, pelvic varices in PCS appear as dilated, tortuous, enhancing tubular structures near the ovaries and uterus. In addition, the extension of varices to the broad ligament and paravaginal venous plexus can be appreciated. With CT, the tubular nature of these structures and the pattern of enhancement after intravenous contrast medium administration distinguish them from lymphadenopathy or adnexal masses. Unlike such masses, pelvic varices appear isodense with other veins after contrast enhancement. Contrast enhanced CT data as part of the combined PET/CT examination provide additional information when compared with non enhanced PET/CT. Because CT data supply the anatomic background for PET, the most important benefit relates to more precise anatomic localization of pathology by differentiation of the lesion from its surrounding structures. By supporting lesion detection and characterization, CT contrast agents can be of additional value in F 18 FDG non avid disease. As in the presented case, careful review of CT images in contrast enhanced PET/CT enables the detection of F 18 FDG non avid disease such as PCS. As contrast enhanced F 18 FDG PET/CT had been performed frequently, being familiar with the findings of PCS on the contrast enhanced CT images would have been helpful for the nuclear medicine physicians.

  2. An evaluation of the clinical diagnostic value of contrast-enhanced ultrasound combined with contrast-enhanced computed tomography in space-occupying lesions of the kidney.

    Science.gov (United States)

    Tian, Wen; Lu, Jianbo; Jiao, Dan; Cong, Zhibin

    2017-01-01

    There are a variety of space-occupying lesions of the kidney, and the benign lesions may be difficult to differentiate from the malignant ones. Therefore, an accurate judgment of the benign and malignant nature of the space-occupying lesions of the kidney is of high importance for the treatment and prognosis of these patients. To evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS) combined with contrast-enhanced computed tomography (CECT) in space-occupying lesions of the kidney. Three hundred and sixty-seven patients with space-occupying lesions of the kidney (378 lesions) were examined by CEUS and CECT, respectively, then, a combined diagnosis was made after the combination of CEUS and CECT by a multidisciplinary team. The diagnoses from the three methods were compared. The pathological results were taken as the gold standard. The sensitivity, specificity, positive and negative predictive values and area under the receiver operating characteristic (ROC) curve were calculated for the three methods. Thus, the diagnostic value of the three methods was assessed. Of the 378 lesions examined, there were 301 malignant lesions and 77 benign lesions. The combined examination revealed 303 malignant lesions, with 9 benign lesions mistakenly diagnosed as malignant ones; thus, the misdiagnosis rate was 11.7%. By using the combined examination, 75 benign lesions were diagnosed, with the missed diagnosis of 7 malignant lesions, so the missed diagnosis rate was 2.3%. The sensitivity, specificity, positive and negative predictive values and area under the ROC curve with the combined examination of CEUS and CECT were 97.67% (0.950-0.989), 88.31% (0.785-0.942), 97.03% (0.942-0.985), 90.67% (0.811-0.958) and 0.930 (0.887-0.973), respectively. As compared with either CEUS or CECT alone, the difference in these indicators was of statistical significance (P<0.05). The combined examination greatly improved the sensitivity, specificity and accuracy of the diagnosis of

  3. Usefulness of dynamic contrast enhanced lumbar spine MR imaging postoperative herniated lumbar disc

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ji Eun; Chung, Tae Sub; Kim, Young Soo; Cho, Yong Eun; Park, Mi Suk [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1999-02-01

    To compare the usefulness of dynamic contrast enhanced lumbar spine MR imaging with that of conventional delayed contrast enhanced MR imaging in the assessment of postoperative herniated lumbar disc. Forty-one postoperative herniated lumbar disc (HLD) lesions of 32 patients with back pain were examined with MR imaging (1.5T, Vision, Siemens, Germany). Five-phase dynamic 2D FLASH sagittal images (TR/TE = 118.1msec/4.1msec) were obtained every 19 seconds with a 4 minutes delayed image after contrast injection. As seen on delayed images, the discs were assessed as recurred, fibrosis, or no change. On dynamic images, the pattern of enhancement was evaluated as follows : Type 1 (no change in peripheral disc enhancement between the early and late phases) ; or Type 2 (minimal internal extension of marginal smooth enhancement during the late phase) ; or Type 3 (marked internal extension of peripheral irregular enhancement). Dynamic and delayed imaging were compared, and early epidural space enhancement with rapid wash-out was also evaluated. Of 41 postoperative HLDs, 39 lesions showed peripheral contrast enhancement. Evaluation depended on delayed imaging, and was as follows : recurred HLD (n=27) ; fibrosis (n=5) ; no change in postoperative disc (n=7). On dynamic contrast-enhanced imaging, enhancement patterns were Type 1 (n=29), Type 2 (n=7), and Type 3 (n=3). In 29 Type 1 lesions, there were no significant differences in image findings between dynamic and delayed images. However, in ten lesions (type 2 : n=7, type 3 : n=3), findings additional to those revealed by delayed images were demonstrated by dynamic contrast-enhanced MR imaging. Nine of the ten Type 2 and 3 lesions were diagnosed as recurred HLD. On dynamic images, five lesions showed early epidural space enhancement. Dynamic contrast-enhanced lumbar spine MR imaging provided additional findings such as increased peripheral disc enhancement, and epidural space enhancement, which cannot be detected on

  4. A Metric for Reducing False Positives in the Computer-Aided Detection of Breast Cancer from Dynamic Contrast-Enhanced Magnetic Resonance Imaging Based Screening Examinations of High-Risk Women.

    Science.gov (United States)

    Levman, Jacob E D; Gallego-Ortiz, Cristina; Warner, Ellen; Causer, Petrina; Martel, Anne L

    2016-02-01

    Magnetic resonance imaging (MRI)-enabled cancer screening has been shown to be a highly sensitive method for the early detection of breast cancer. Computer-aided detection systems have the potential to improve the screening process by standardizing radiologists to a high level of diagnostic accuracy. This retrospective study was approved by the institutional review board of Sunnybrook Health Sciences Centre. This study compares the performance of a proposed method for computer-aided detection (based on the second-order spatial derivative of the relative signal intensity) with the signal enhancement ratio (SER) on MRI-based breast screening examinations. Comparison is performed using receiver operating characteristic (ROC) curve analysis as well as free-response receiver operating characteristic (FROC) curve analysis. A modified computer-aided detection system combining the proposed approach with the SER method is also presented. The proposed method provides improvements in the rates of false positive markings over the SER method in the detection of breast cancer (as assessed by FROC analysis). The modified computer-aided detection system that incorporates both the proposed method and the SER method yields ROC results equal to that produced by SER while simultaneously providing improvements over the SER method in terms of false positives per noncancerous exam. The proposed method for identifying malignancies outperforms the SER method in terms of false positives on a challenging dataset containing many small lesions and may play a useful role in breast cancer screening by MRI as part of a computer-aided detection system.

  5. Contrast-enhanced ultrasound in ovarian tumors – diagnostic parameters: method presentation and initial experience

    Science.gov (United States)

    MAXIM, ANITA-ROXANA; BADEA, RADU; TAMAS, ATILLA; TRAILA, ALEXANDRU

    2013-01-01

    The aim of this paper is to discuss and illustrate the use of contrast-enhanced ultrasound in evaluating ovarian tumors compared to conventional ultrasound, Doppler ultrasound and the histopathological analysis and suggest how this technique may best be used to distinguish benign from malignant ovarian masses. We present the method and initial experience of our center by analyzing the parameters used in contrast-enhanced ultrasound in 6 patients with ovarian tumors of uncertain etiology. For examination we used a Siemens ultrasound machine with dedicated contrast software and the contrast agent SonoVue, Bracco. The patients underwent conventional ultrasound, Doppler ultrasound and i.v. administration of the contrast agent. The parameters studied were: inflow of contrast (rise time), time to peak enhancement, mean transit time. The series of patients is part of an extensive prospective PhD study aimed at elaborating a differential diagnosis protocol for benign versus malignant ovarian tumors, by validating specific parameters for contrast-enhanced ultrasound. Although the method is currently used with great success in gastroenterology, urology and senology, its validation in gynecology is still in the early phases. Taking into consideration that the method is minimally invasive and much less costly that CT/MRI imaging, demonstrating its utility in oncologic gynecology would be a big step in preoperative evaluation of these cases. PMID:26527912

  6. Nanodiamond-Manganese dual mode MRI contrast agents for enhanced liver tumor detection.

    Science.gov (United States)

    Hou, Weixin; Toh, Tan Boon; Abdullah, Lissa Nurrul; Yvonne, Tay Wei Zheng; Lee, Kuan J; Guenther, Ilonka; Chow, Edward Kai-Hua

    2017-04-01

    Contrast agent-enhanced magnetic resonance (MR) imaging is critical for the diagnosis and monitoring of a number of diseases, including cancer. Certain clinical applications, including the detection of liver tumors, rely on both T1 and T2-weighted images even though contrast agent-enhanced MR imaging is not always reliable. Thus, there is a need for improved dual mode contrast agents with enhanced sensitivity. We report the development of a nanodiamond-manganese dual mode contrast agent that enhanced both T1 and T2-weighted MR imaging. Conjugation of manganese to nanodiamonds resulted in improved longitudinal and transverse relaxivity efficacy over unmodified MnCl 2 as well as clinical contrast agents. Following intravenous administration, nanodiamond-manganese complexes outperformed current clinical contrast agents in an orthotopic liver cancer mouse model while also reducing blood serum concentration of toxic free Mn 2+ ions. Thus, nanodiamond-manganese complexes may serve as more effective dual mode MRI contrast agent, particularly in cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Automatic x-ray image contrast enhancement based on parameter auto-optimization.

    Science.gov (United States)

    Qiu, Jianfeng; Harold Li, H; Zhang, Tiezhi; Ma, Fangfang; Yang, Deshan

    2017-11-01

    Insufficient image contrast associated with radiation therapy daily setup x-ray images could negatively affect accurate patient treatment setup. We developed a method to perform automatic and user-independent contrast enhancement on 2D kilo voltage (kV) and megavoltage (MV) x-ray images. The goal was to provide tissue contrast optimized for each treatment site in order to support accurate patient daily treatment setup and the subsequent offline review. The proposed method processes the 2D x-ray images with an optimized image processing filter chain, which consists of a noise reduction filter and a high-pass filter followed by a contrast limited adaptive histogram equalization (CLAHE) filter. The most important innovation is to optimize the image processing parameters automatically to determine the required image contrast settings per disease site and imaging modality. Three major parameters controlling the image processing chain, i.e., the Gaussian smoothing weighting factor for the high-pass filter, the block size, and the clip limiting parameter for the CLAHE filter, were determined automatically using an interior-point constrained optimization algorithm. Fifty-two kV and MV x-ray images were included in this study. The results were manually evaluated and ranked with scores from 1 (worst, unacceptable) to 5 (significantly better than adequate and visually praise worthy) by physicians and physicists. The average scores for the images processed by the proposed method, the CLAHE, and the best window-level adjustment were 3.92, 2.83, and 2.27, respectively. The percentage of the processed images received a score of 5 were 48, 29, and 18%, respectively. The proposed method is able to outperform the standard image contrast adjustment procedures that are currently used in the commercial clinical systems. When the proposed method is implemented in the clinical systems as an automatic image processing filter, it could be useful for allowing quicker and potentially more

  8. Management of Indeterminate Cystic Kidney Lesions: Review of Contrast-enhanced Ultrasound as a Diagnostic Tool.

    Science.gov (United States)

    Chang, Emily H; Chong, Wui K; Kasoji, Sandeep K; Dayton, Paul A; Rathmell, W Kimryn

    2016-01-01

    Indeterminate cystic kidney lesions found incidentally are an increasingly prevalent diagnostic challenge. Standard workup includes Bosniak classification with contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI). However, these tests are costly and not without risks. Contrast-enhanced ultrasound (CEUS) is a relatively new technique with lower risk of adverse events than iodine-containing contrast or gadolinium. In our review of the evidence for characterization of cystic kidney lesions with CEUS, CEUS displayed sensitivity (89%-100%) and negative predictive value (86%-100%) comparable to contrast-enhanced CT or MRI, with no decrease in specificity compared with CT and only a slight decrease compared with MRI. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Computationally Designed Oligomers for High Contrast Black Electrochromic Polymers

    Science.gov (United States)

    2017-05-05

    AFRL-AFOSR-VA-TR-2017-0097 Computationally Designed Oligomers for High Contrast Black Electrochromic Polymers Aimee Tomlinson University Of North...Black Electrochromic FA9550-15-1-0181 Polymers 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6.AUTHO~ 5d. PROJECT NUMBER AimeeL. T . Se. TASK...neraly black neutral state. Additionally, upon oxidation these polymers would have litte to no tailing form the near IR thereby guaranteeing nearly a I

  10. Contrast-enhanced digital mammography (CEDM): phantom experiment and first clinical results

    Science.gov (United States)

    Marx, Christiane; Facius, Mirijam; Muller, Serge L.; Benali, Karim; Malich, Ansgar; Kaiser, Werner

    2002-05-01

    The introduction of the Full Field Digital Mammography (FFDM) opens the way to a large range of future advanced applications. Among them, Contrast Enhanced Digital Mammography (CEDM) could be a fast and less expensive alternative to Magnetic Resonance Imaging (MRI) for breast lesion characterization. In this work, we have investigated, first on phantom then on patients, the capability of a modified FFDM system to show the contrast enhancement of lesions after intra-venous injection of iodine. The uptake has been estimated from the difference between pre- and post-contrast images. Phantom results showed that 1) detectability thresholds of the contrast media were compatible with clinical conditions; 2) breast radiological thickness has a low impact on uptake detectability; 3) spatial and temporal analysis showed delayed margin contrast uptake of the simulated lesion and slow increase of contrast in the background. Preliminary results on patients have confirmed the phantom results and have shown a contrast uptake in all malignant lesions despite the observed patient motion artifacts, and some moderate signal variability. This study demonstrated the feasibility of the Contrast Enhanced Digital Mammography technique. Further investigations and clinical validations will have to be completed before it can be widely used in a daily routine practice.

  11. Epithelial cell biocompatibility of silica nanospheres for contrast-enhanced ultrasound molecular imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chiriaco, Fernanda; Conversano, Francesco; Soloperto, Giulia; Casciaro, Ernesto [Institute of Clinical Physiology, Bioengineering Division, National Research Council (Italy); Ragusa, Andrea [National Nanotechnology Laboratory of CNR-NANO (Italy); Sbenaglia, Enzo Antonio; Dipaola, Lucia [Institute of Clinical Physiology, Bioengineering Division, National Research Council (Italy); Casciaro, Sergio, E-mail: sergio.casciaro@cnr.it [Istituto di Fisiologia Clinica (CNR-IFC) c/o Campus Universitario Ecotekne, Consiglio Nazionale delle Ricerche (Italy)

    2013-07-15

    Nanosized particles are receiving increasing attention as future contrast agents (CAs) for ultrasound (US) molecular imaging, possibly decorated on its surface with biological recognition agents for targeted delivery and deposition of therapeutics. In particular, silica nanospheres (SiNSs) have been demonstrated to be feasible in terms of contrast enhancement on conventional US systems. In this work, we evaluated the cytotoxicity of SiNSs on breast cancer (MCF-7) and HeLa (cervical cancer) cells employing NSs with sizes ranging from 160 to 330 nm and concentration range of 1.5-5 mg/mL. Cell viability was evaluated in terms of size, dose and time dependence, performing the MTT reduction assay with coated and uncoated SiNSs. Whereas uncoated SiNSs caused a variable significant decrease in cell viability on both cell lines mainly depending on size and exposure time, PEGylated SiNSs (SiNSs-PEG) exhibit a high level of biocompatibility. In fact, after 72-h incubation, viability of both cell types was above the cutoff value of 70 % at concentration up to 5 mg/mL. We also investigated the acoustical behavior of coated and uncoated SiNSs within conventional diagnostic US fields in order to determine a suitable configuration, in terms of particle size and concentration, for their employment as targetable CAs. Our results indicate that the employment of SiNSs with diameters around 240 nm assures the most effective contrast enhancement even at the lowest tested concentration, coupled with the possibility of targeting all tumor tissues, being the SiNSs still in a size range where reticuloendothelial system trapping effect is relatively low.

  12. Dual-energy contrast-enhanced digital mammography: initial clinical results of a multireader, multicase study.

    Science.gov (United States)

    Dromain, Clarisse; Thibault, Fabienne; Diekmann, Felix; Fallenberg, Eva M; Jong, Roberta A; Koomen, Marcia; Hendrick, R Edward; Tardivon, Anne; Toledano, Alicia

    2012-06-14

    The purpose of this study was to compare the diagnostic accuracy of dual-energy contrast-enhanced digital mammography (CEDM) as an adjunct to mammography (MX) ± ultrasonography (US) with the diagnostic accuracy of MX ± US alone. One hundred ten consenting women with 148 breast lesions (84 malignant, 64 benign) underwent two-view dual-energy CEDM in addition to MX and US using a specially modified digital mammography system (Senographe DS, GE Healthcare). Reference standard was histology for 138 lesions and follow-up for 12 lesions. Six radiologists from 4 institutions interpreted the images using high-resolution softcopy workstations. Confidence of presence (5-point scale), probability of cancer (7-point scale), and BI-RADS scores were evaluated for each finding. Sensitivity, specificity and ROC curve areas were estimated for each reader and overall. Visibility of findings on MX ± CEDM and MX ± US was evaluated with a Likert scale. The average per-lesion sensitivity across all readers was significantly higher for MX ± US ± CEDM than for MX ± US (0.78 vs. 0.71 using BIRADS, p = 0.006). All readers improved their clinical performance and the average area under the ROC curve was significantly superior for MX ± US ± CEDM than for MX ± US ((0.87 vs 0.83, p = 0.045). Finding visibility was similar or better on MX ± CEDM than MX ± US in 80% of cases. Dual-energy contrast-enhanced digital mammography as an adjunct to MX ± US improves diagnostic accuracy compared to MX ± US alone. Addition of iodinated contrast agent to MX facilitates the visualization of breast lesions.

  13. Epithelial cell biocompatibility of silica nanospheres for contrast-enhanced ultrasound molecular imaging

    Science.gov (United States)

    Chiriacò, Fernanda; Conversano, Francesco; Soloperto, Giulia; Casciaro, Ernesto; Ragusa, Andrea; Sbenaglia, Enzo Antonio; Dipaola, Lucia; Casciaro, Sergio

    2013-07-01

    Nanosized particles are receiving increasing attention as future contrast agents (CAs) for ultrasound (US) molecular imaging, possibly decorated on its surface with biological recognition agents for targeted delivery and deposition of therapeutics. In particular, silica nanospheres (SiNSs) have been demonstrated to be feasible in terms of contrast enhancement on conventional US systems. In this work, we evaluated the cytotoxicity of SiNSs on breast cancer (MCF-7) and HeLa (cervical cancer) cells employing NSs with sizes ranging from 160 to 330 nm and concentration range of 1.5-5 mg/mL. Cell viability was evaluated in terms of size, dose and time dependence, performing the MTT reduction assay with coated and uncoated SiNSs. Whereas uncoated SiNSs caused a variable significant decrease in cell viability on both cell lines mainly depending on size and exposure time, PEGylated SiNSs (SiNSs-PEG) exhibit a high level of biocompatibility. In fact, after 72-h incubation, viability of both cell types was above the cutoff value of 70 % at concentration up to 5 mg/mL. We also investigated the acoustical behavior of coated and uncoated SiNSs within conventional diagnostic US fields in order to determine a suitable configuration, in terms of particle size and concentration, for their employment as targetable CAs. Our results indicate that the employment of SiNSs with diameters around 240 nm assures the most effective contrast enhancement even at the lowest tested concentration, coupled with the possibility of targeting all tumor tissues, being the SiNSs still in a size range where reticuloendothelial system trapping effect is relatively low.

  14. Relationship between enhanced intensity of contrast enhanced ultrasound and microvessel density of aortic atherosclerostic plaque in rabbit model.

    Directory of Open Access Journals (Sweden)

    Xiangdong You

    Full Text Available The aim of this study was to evaluate the relationship between enhanced intensity of contrast enhanced ultrasound and microvessel density of aortic atherosclerotic plaque in rabbit model. The abdominal aortas of thirty-six male New Zealand rabbits were damaged by balloon expansion and the animals were then fed a high fat diet for 12 weeks. Twenty-seven plaques on the near aortic wall were detected using conventional ultrasound examination. The maximum thickness of each plaque was recorded. CEUS was performed on these 27 plaques and the time-intensity curves (TICs were analyzed offline. Using the quantitative ACQ software, features such as the arrival time (AT, time to peak (TTP, baseline intensity (BI, peak intensity (PI and enhanced intensity (EI (EI = PI-BI were assessed. Inter- and intra-observer agreement of EI were assessed using the Bland-Altman test. After CEUS examination, the rabbits were sacrificed for pathological examination and CD34 monoclonal antibody immunohistochemical detection. Microvessel density (MVD was counted under the microscope. The relationship between indexes of CEUS and the level of MVD was analyzed. There was a good positive linear correlation between EI and MVD (γ = 0. 854, P<0. 001, the intraclass correlations for inter- and intra-observer agreement for EI were 0.73 and 0.82 respectively, suggesting that EI may be act as a useful index for plaque risk stratification in animal models.

  15. High-contrast x-ray microtomography in dental research

    Science.gov (United States)

    Davis, Graham; Mills, David

    2017-09-01

    X-ray microtomography (XMT) is a well-established technique in dental research. The technique has been used extensively to explore the complex morphology of the root canal system, and to qualitatively and quantitatively evaluate root canal instrumentation and filling efficacy in extracted teeth; enabling different techniques to be compared. Densitometric information can be used to identify and map demineralized tissue resulting from tooth decay (caries) and, in extracted teeth, the method can be used to evaluate different methods of excavation. More recently, high contrast XMT is being used to investigate the relationship between external insults to teeth and the pulpal reaction. When such insults occur, fluid may flow through dentinal tubules as a result of cracking or porosity in enamel. Over time, there is an increase in mineralization along the paths of the tubules from the pulp to the damaged region in enamel and this can be visualized using high contrast XMT. The scanner used for this employs time-delay integration to minimize the effects of detector inhomogeneity in order to greatly increase the upper limit on signal-to-noise ratio that can be achieved with long exposure times. When enamel cracks are present in extracted teeth, the presence of these pathways indicates that the cracking occurred prior to extraction. At high contrast, growth lines are occasionally seen in deciduous teeth which may have resulted from periods of maternal illness. Various other anomalies in mineralization resulting from trauma or genetic abnormalities can also be investigated using this technique.

  16. Contrast-enhanced time-resolved 3-D MRA: applications in neurosurgery and interventional neuroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Reinacher, Peter C.; Stracke, Paul; Reinges, Marcus H.T.; Hans, Franz J.; Krings, Timo [University Hospital of the Technical University, Department of Neurosurgery, Aachen (Germany)

    2007-07-15

    The decision-making process in the endovascular treatment of cranial dural AV fistulas and angiomas and their follow-up after treatment is usually based on conventional digital subtraction angiography (DSA). Likewise, acquiring the vascular and hemodynamic information needed for presurgical evaluation of meningiomas may necessitate DSA or different MR-based angiographic methods to assess the arterial displacement, the location of bridging veins and tumor feeders, and the degree of vascularization. New techniques of contrast-enhanced MR angiography (MRA) permit the acquisition of images with high temporal and spatial resolution. The purpose of this study was to evaluate the applicability and clinical use of a newly developed contrast-enhanced 3-D dynamic MRA protocol for neurointerventional and neurosurgical planning and decision making. With a 3-T whole-body scanner (Philips Achieva), a 3-D dynamic contrast-enhanced (MultiHance, Bracco) MRA sequence with parallel imaging, and intelligent k-space readout (keyhole and ''CENTRA'' k-space filling) was added to structural MRI in patients with meningiomas, dural arteriovenous fistulas and pial arteriovenous malformations. The sequence had a temporal resolution of 1.3 s per 3-D volume with a spatial resolution of 0.566 x 0.566 x 1.5 mm per voxel in each 3-D volume and lasted 25.2 s. DSA was performed in selected patients following MRI. In patients with arteriovenous fistulas and malformations, MRA allowed the vascular shunt to be identified and correctly classified. Hemodynamic characteristics and venous architecture were clearly demonstrated. Larger feeding arteries could be identified in all patients. In meningiomas, MRA enabled assessment of the displacement of the cerebral arteries, depiction of the tumor feeding vessels, and evaluation of the anatomy of the venous system. The extent of tumor vascularization could be assessed in all patients and correlated with the histopathological findings that

  17. [Quantitative parametric analysis of contrast-enhanced lesions in dynamic MR mammography].

    Science.gov (United States)

    Hauth, E A M; Jaeger, H; Maderwald, S; Mühler, A; Kimmig, R; Forsting, M

    2008-06-01

    The aim of the study was an evaluation of the quantitative parametric analysis of contrast-enhanced lesions in dynamic MR mammography. In 137 patients, 183 contrast-enhanced lesions were identified in dynamic MR mammography. In 82 lesions histopathology was performed and in 101 lesions follow-up MR mammography was carried out. The contrast kinetics of lesions was analyzed quantitatively, on a pixel-by-pixel basis. The initial signal enhancement was coded by color intensity (bright, medium, dark), the post-initial signal enhancement was coded by color hue (blue, green, red). ROC analysis and logistic regression were performed. Malignant lesions showed a significantly higher number of bright red, medium red and dark red, bright green and medium green pixels than benign lesions. Benign lesions showed a significantly higher number of bright blue, medium blue and dark blue pixels than malignant lesions. The highest areas under the ROC curves (AUC) were found for medium red (AUC = 0.782) and medium green pixels (AUC = 0.733). A regression model with medium red and medium green pixels allows diagnosis of malignant lesions with a sensitivity of 60.7% and a specificity of 83.6%. The quantification of contrast-enhanced lesions allows objective analysis of the signal intensities in malignant and benign lesions. Therefore, this method might increase the specificity of MR mammography. Further developments are necessary before this method can be used for routine analysis of contrast-enhancing lesions in MR mammography.

  18. Assessment of the link between quantitative biexponential diffusion-weighted imaging and contrast-enhanced MRI in the liver.

    Science.gov (United States)

    Dijkstra, Hildebrand; Oudkerk, Matthijs; Kappert, Peter; Sijens, Paul E

    2017-05-01

    To investigate if intravoxel incoherent motion (IVIM) modeled diffusion-weighted imaging (DWI) can be linked to contrast-enhanced (CE-)MRI in liver parenchyma and liver lesions. Twenty-five patients underwent IVIM-DWI followed by multiphase CE-MRI using Gd-EOB-DTPA (n=20) or Gd-DOTA (n=5) concluded with IVIM-DWI. Diffusion (Dslow), microperfusion (Dfast), its fraction (ffast), wash-in-rate (Rearly) and late-enhancement-rate (Rlate) of Gd-EOB-DTPA were calculated voxel-wise for the liver. Parenchyma and lesions were segmented. Pre-contrast IVIM was compared 1) between low, medium and high Rearly for parenchyma 2) to post-contrast IVIM substantiated with simulations 3) between low and high Rlate per lesion type. Dfast and ffast increased (Pquantitative liver imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. [Properties of gas (CO2) microbubbles made by hand agitation and it's contrast enhancing effect].

    Science.gov (United States)

    Matsuda, Y; Yabuuchi, I; Ito, T

    1998-04-01

    The property of gas (CO2) microbubbles made by hand agitation and it's contrast enhancing effect of abdominal organs on gray scale ultrasound are here described. The size of microbubbles of CO2 gas adequately prepared with 5% human serum albumin was nearly 23 microns in mean diameter. However, the size and the density of gas microbubbles are affected with many factors, including mixing times, volume ratio of gas and liquid and the species of gas and liquid. On the other hand, contrast enhancing effect is determined by the size and the density of gas microbubbles. For the adequate evaluation of contrast enhancing effect of abdominal tumors by enhanced ultrasonography, the property of gas microbubbles described as above should be carefully considered.

  20. Real-time contrast enhanced ultrasound imaging of focal splenic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei [Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-Sen University, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou (China); Liu, GuangJian, E-mail: liugj@mail.sysu.edu.cn [Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-Sen University, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou (China); Wang, Wei; Wang, Zhu; Huang, Yang; Xu, ZuoFeng; Xie, XiaoYan [Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-Sen University, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou (China); Lu, MingDe [Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-Sen University, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, Guangzhou (China); Department of Hepatobiliary Surgery, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou (China)

    2014-04-15

    Objective: To investigate the imaging features of focal splenic lesions (FSLs) on contrast-enhanced ultrasound (CEUS). Methods: Thirty two patients with FSLs proved by pathology were retrospectively analyzed. CEUS was performed using intravenous bolus injection of 2.4 ml sulfur hexafluoride-filled microbubble contrast agent and real time scanning. There were hemangioma (n = 7), lymphoma (n = 8), true cyst (n = 3), infarction (n = 4), hematolymphangioma (n = 2), metastasis tumor (n = 2), and one for each of the following entities extramedullary hemopoiesis, hamartoma, tuberculosis, Langerhans’ cell histiocytosis, inflammatory pseudotumor and myxofibrosarcoma. Results: Among 21 benign lesions, 4 infarctions and 3 cysts presented non-enhancement throughout CEUS scanning, and the other 14 lesions displayed various enhancement levels with 6 (42.9%) hyper-enhancement, 2 (14.3%) iso-enhancement and 6 (42.9%) hypo-enhancement in arterial phase and 11 (78.6%) hypo-enhancement, 1 (7.1%) iso-enhancement and 2 (14.3%) hyper-enhancement in late phase, respectively. The enhancement pattern included 9 (64.3%) homogeneous, 4 (28.6%) heterogeneous and 1 (7.1%) rim-like enhancement. As for the malignant FSLs, all the lesions became completely or extensively hypo-enhancement during the late phase no matter their vascularity during arterial phase. Conclusions: The CEUS features reported in this series may enrich the knowledge for CEUS characterization of FSLs.

  1. Contrast-Enhancement of the Anterior Eye Segment in Patients with Retinoblastoma: Correlation between Clinical, MR Imaging, and Histopathologic Findings

    NARCIS (Netherlands)

    de Graaf, P.; van der Valk, P.; Moll, A. C.; Imhof, S. M.; Schouten-van Meeteren, A. Y. N.; Knol, D. L.; Castelijns, J. A.

    2010-01-01

    BACKGROUND AND PURPOSE: AES contrast-enhancement is recognized in a substantial number of retinoblastoma-affected eyes. We retrospectively investigated the histopathologic basis of AES contrast-enhancement on MR images in retinoblastoma. MATERIALS AND METHODS: Pretreatment contrast-enhanced MR

  2. Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging

    Directory of Open Access Journals (Sweden)

    Shengtao Lin

    2017-06-01

    Full Text Available We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1 photoacoustic imaging contrast, 2 ultrasound contrast with optical activation, and 3 ultrasound contrast with acoustic activation. This agent, which we name ‘Cy-droplet’, has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration. It is manufactured via a ‘microbubble condensation’ method. The phase-transition of Cy-droplets can be optically triggered by pulsed-laser illumination, inducing photoacoustic signal and forming stable gas bubbles that are visible with echo-ultrasound in situ. Alternatively, Cy-droplets can be converted to microbubble contrast agents upon acoustic activation with clinical ultrasound. Potentially all modes offer extravascular contrast enhancement because of the sub-micron initial size. Such versatility of acoustic and optical ‘triggerability’ can potentially improve multi-modality imaging, molecularly targeted imaging and controlled drug release.

  3. Optically and acoustically triggerable sub-micron phase-change contrast agents for enhanced photoacoustic and ultrasound imaging.

    Science.gov (United States)

    Lin, Shengtao; Shah, Anant; Hernández-Gil, Javier; Stanziola, Antonio; Harriss, Bethany I; Matsunaga, Terry O; Long, Nicholas; Bamber, Jeffrey; Tang, Meng-Xing

    2017-06-01

    We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1) photoacoustic imaging contrast, 2) ultrasound contrast with optical activation, and 3) ultrasound contrast with acoustic activation. This agent, which we name 'Cy-droplet', has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration. It is manufactured via a 'microbubble condensation' method. The phase-transition of Cy-droplets can be optically triggered by pulsed-laser illumination, inducing photoacoustic signal and forming stable gas bubbles that are visible with echo-ultrasound in situ . Alternatively, Cy-droplets can be converted to microbubble contrast agents upon acoustic activation with clinical ultrasound. Potentially all modes offer extravascular contrast enhancement because of the sub-micron initial size. Such versatility of acoustic and optical 'triggerability' can potentially improve multi-modality imaging, molecularly targeted imaging and controlled drug release.

  4. High contrast observations of bright stars with a starshade

    Science.gov (United States)

    Harness, Anthony; Cash, Webster; Warwick, Steve

    2017-12-01

    Starshades are a leading technology to enable the direct detection and spectroscopic characterization of Earth-like exoplanets. In an effort to advance starshade technology through system level demonstrations, the McMath-Pierce Solar Telescope was adapted to enable the suppression of astronomical sources with a starshade. The long baselines achievable with the heliostat provide measurements of starshade performance at a flight-like Fresnel number and resolution, aspects critical to the validation of optical models. The heliostat has provided the opportunity to perform the first astronomical observations with a starshade and has made science accessible in a unique parameter space, high contrast at moderate inner working angles. On-sky images are valuable for developing the experience and tools needed to extract science results from future starshade observations. We report on high contrast observations of nearby stars provided by a starshade. We achieve 5.6 × 10- 7 contrast at 30 arcseconds inner working angle on the star Vega and provide new photometric constraints on background stars near Vega.

  5. Counter-propagating wave interaction for contrast-enhanced ultrasound imaging

    Science.gov (United States)

    Renaud, G.; Bosch, J. G.; ten Kate, G. L.; Shamdasani, V.; Entrekin, R.; de Jong, N.; van der Steen, A. F. W.

    2012-11-01

    Most techniques for contrast-enhanced ultrasound imaging require linear propagation to detect nonlinear scattering of contrast agent microbubbles. Waveform distortion due to nonlinear propagation impairs their ability to distinguish microbubbles from tissue. As a result, tissue can be misclassified as microbubbles, and contrast agent concentration can be overestimated; therefore, these artifacts can significantly impair the quality of medical diagnoses. Contrary to biological tissue, lipid-coated gas microbubbles used as a contrast agent allow the interaction of two acoustic waves propagating in opposite directions (counter-propagation). Based on that principle, we describe a strategy to detect microbubbles that is free from nonlinear propagation artifacts. In vitro images were acquired with an ultrasound scanner in a phantom of tissue-mimicking material with a cavity containing a contrast agent. Unlike the default mode of the scanner using amplitude modulation to detect microbubbles, the pulse sequence exploiting counter-propagating wave interaction creates no pseudoenhancement behind the cavity in the contrast image.

  6. Association of dynamic susceptibility contrast enhanced MR Perfusion parameters with prognosis in elderly patients with glioblastomas

    Energy Technology Data Exchange (ETDEWEB)

    Jabehdar Maralani, Pejman [University of Toronto, Department of Medical Imaging, Sunnybrook Health Sciences Center, Toronto, ON (Canada); Melhem, Elias R.; Herskovits, Edward H. [University of Maryland Medical Center, Department of Radiology, Baltimore, MD (United States); Wang, Sumei; Voluck, Matthew R.; Learned, Kim O.; Mohan, Suyash [Perelman School of Medicine at University of Pennsylvania, Department of Radiology, Division of Neuroradiology, Philadelphia, PA (United States); Kim, Sang Joon [University of Ulsan Asan Medical Center, Department of Radiology, Songpa-gu, Seoul (Korea, Republic of); O' Rourke, Donald M. [Perelman School of Medicine at University of Pennsylvania, Department of Surgery, Division of Neurosurgery, Philadelphia, PA (United States)

    2015-09-15

    We aimed to evaluate the prognostic value of dynamic susceptibility contrast (DSC) MR perfusion in elderly patients with glioblastomas (GBM). Thirty five patients aged ≥65 and 35 aged <65 years old, (referred to as elderly and younger, respectively) were included in this retrospective study. The median relative cerebral volume (rCBV) from the enhancing region (rCBV{sub ER-Med}) and immediate peritumoral region (rCBV{sub IPR-Med}) and maximum rCBV from the enhancing region of the tumor (rCBV{sub ER-Max}) were compared and correlated with survival data. Analysis was repeated after rCBVs were dichotomized into high and low values and after excluding elderly patients who did not receive postoperative chemoradiation (34.3 %). Kaplan-Meyer survival curves and parametric and semi-parametric regression tests were used for analysis. All rCBV parameters were higher in elderly compared to younger patients (p < 0.05). After adjustment for age, none were independently associated with shorter survival (p > 0.05). After rCBV dichotomization into high and low values, high rCBV in elderly was independently associated with shorter survival compared to low rCBV in elderly, or any rCBV in younger patients (p < 0.05). rCBV can be an imaging biomarker to identify a subgroup of GBM patients in the elderly with worse prognosis compared to others. (orig.)

  7. Moderate Contrast in the Evaluation of Paintings Is Liked More but Remembered Less than High Contrast

    Directory of Open Access Journals (Sweden)

    Katinka Dijkstra

    2017-09-01

    Full Text Available Many visual aspects of paintings, as well as exposure to art and cultural norms, contribute to the aesthetic evaluation of paintings. The current study looked at heightened visual contrast as an important factor in the appreciation of paintings. Participants evaluated abstract digitized paintings that were manipulated in contrast for an appreciation task and were later presented with these paintings in a memory task. The results indicated that for art appreciation, a moderate increase in contrast resulted in the highest appreciation for paintings whereas recognition memory was better for paintings with a higher increase in contrast. These results replicate earlier findings with regard to the role of contrast in aesthetic perception and extend these findings by demonstrating a surprising different effect of contrast manipulation for recognition memory. Confidence with which memory decisions were made was in line with art appreciation decisions not memory performance.

  8. Moderate Contrast in the Evaluation of Paintings Is Liked More but Remembered Less than High Contrast.

    Science.gov (United States)

    Dijkstra, Katinka; van Dongen, Noah N N

    2017-01-01

    Many visual aspects of paintings, as well as exposure to art and cultural norms, contribute to the aesthetic evaluation of paintings. The current study looked at heightened visual contrast as an important factor in the appreciation of paintings. Participants evaluated abstract digitized paintings that were manipulated in contrast for an appreciation task and were later presented with these paintings in a memory task. The results indicated that for art appreciation, a moderate increase in contrast resulted in the highest appreciation for paintings whereas recognition memory was better for paintings with a higher increase in contrast. These results replicate earlier findings with regard to the role of contrast in aesthetic perception and extend these findings by demonstrating a surprising different effect of contrast manipulation for recognition memory. Confidence with which memory decisions were made was in line with art appreciation decisions not memory performance.

  9. Diagnostic accuracy of segmental enhancement inversion for diagnosis of renal oncocytoma at biphasic contrast enhanced CT: systematic review.

    Science.gov (United States)

    Schieda, Nicola; McInnes, Matthew D F; Cao, Lilly

    2014-06-01

    To use systematic review to evaluate the diagnostic accuracy of segmental enhancement inversion (SEI) at contrast-enhanced biphasic multi-detector computed tomography (MDCT) for the diagnosis of renal oncocytoma. Several electronic databases were searched through October 2013. Two reviewers independently selected studies that met the inclusion criteria and extracted data. Study quality was assessed with the QUADAS-2 tool. The primary 2 × 2 data were investigated with forest plot and ROC plot of sensitivity and specificity. Four studies met the inclusion criteria (307 patients). Considerable heterogeneity between studies precluded meta-analysis. Two studies from the same group of investigators demonstrated reasonable diagnostic accuracy (sensitivity 59-80 % and specificity 87-99 %), while two others did not (sensitivity 0-6 %, specificity 93-100 %). Possible reasons for this include timing of biphasic MDCT and methods of interpretation but not size of lesion. SEI is a specific imaging finding of renal oncocytoma with highly variable sensitivity. This substantial heterogeneity across studies and between institutions suggests that further validation of this imaging finding is necessary prior to application in clinical practice. SEI on CT in small renal masses is specific for oncocytoma. Sensitivity of SEI varies substantially between studies and across institutions. Variability could relate to CT timing or methods of interpretation. High accuracy of SEI has only been reported by one group. Validation of SEI is needed prior to clinical implementation.

  10. Attenuation Correction and Normalisation for Quantification of Contrast Enhancement in Ultrasound Images of Carotid Arteries.

    Science.gov (United States)

    Cheung, Wing Keung; Gujral, Dorothy M; Shah, Benoy N; Chahal, Navtej S; Bhattacharyya, Sanjeev; Cosgrove, David O; Eckersley, Robert J; Harrington, Kevin J; Senior, Roxy; Nutting, Christopher M; Tang, Meng-Xing

    2015-07-01

    An automated attenuation correction and normalisation algorithm was developed to improve the quantification of contrast enhancement in ultrasound images of carotid arteries. The algorithm first corrects attenuation artefact and normalises intensity within the contrast agent-filled lumen and then extends the correction and normalisation to regions beyond the lumen. The algorithm was first validated on phantoms consisting of contrast agent-filled vessels embedded in tissue-mimicking materials of known attenuation. It was subsequently applied to in vivo contrast-enhanced ultrasound (CEUS) images of human carotid arteries. Both in vitro and in vivo results indicated significant reduction in the shadowing artefact and improved homogeneity within the carotid lumens after the correction. The error in quantification of microbubble contrast enhancement caused by attenuation on phantoms was reduced from 55% to 5% on average. In conclusion, the proposed method exhibited great potential in reducing attenuation artefact and improving quantification in contrast-enhanced ultrasound of carotid arteries. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  11. Contrast-enhanced Magnetic Resonance Imaging in Pediatric Patients: Review and Recommendations for Current Practice

    Directory of Open Access Journals (Sweden)

    Ravi Bhargava

    2013-01-01

    Full Text Available Magnetic resonance imaging (MRI, frequently with contrast enhancement, is the preferred imaging modality for many indications in children. Practice varies widely between centers, reflecting the rapid pace of change and the need for further research. Guideline changes, for example on contrast-medium choice, require continued practice reappraisal. This article reviews recent developments in pediatric contrast-enhanced MRI and offers recommendations on current best practice. Nine leading pediatric radiologists from internationally recognized radiology centers convened at a consensus meeting in Bordeaux, France, to discuss applications of contrast-enhanced MRI across a range of indications in children. Review of the literature indicated that few published data provide guidance on best practice in pediatric MRI. Discussion among the experts concluded that MRI is preferred over ionizing-radiation modalities for many indications, with advantages in safety and efficacy. Awareness of age-specific adaptations in MRI technique can optimize image quality. Gadolinium-based contrast media are recommended for enhancing imaging quality. The choice of most appropriate contrast medium should be based on criteria of safety, tolerability, and efficacy, characterized in age-specific clinical trials and personal experience.

  12. T1-refBlochi: high resolution 3D post-contrast T1 myocardial mapping based on a single 3D late gadolinium enhancement volume, Bloch equations, and a reference T1.

    Science.gov (United States)

    Hu, Chenxi; Sinusas, Albert J; Huber, Steffen; Thorn, Stephanie; Stacy, Mitchel R; Mojibian, Hamid; Peters, Dana C

    2017-08-18

    High resolution 3D T1 mapping is important for assessment of diffuse myocardial fibrosis in left atrium or other thin-walled structures. In this work, we investigated a fast single-TI 3D high resolution T1 mapping method that directly transforms a 3D late gadolinium enhancement (LGE) volume to a 3D T1 map. The proposed method, T1-refBlochi, is based on Bloch equation modeling of the LGE signal, a single-point calibration, and assumptions that proton density and T2* are relatively uniform in the heart. Several sources of error of this method were analyzed mathematically and with simulations. Imaging was performed in phantoms, eight swine and five patients, comparing T1-refBlochi to a standard spin-echo T1 mapping, 3D multi-TI T1 mapping, and 2D ShMOLLI, respectively. The method has a good accuracy and adequate precision, even considering various sources of error. In phantoms, over a range of protocols, heart-rates and T1 s, the bias ±1SD was -3 ms ± 9 ms. The porcine studies showed excellent agreement between T1-refBlochi and the multi-TI method (bias ±1SD = -6 ± 22 ms). The proton density and T2* weightings yielded ratios for scar/blood of 0.94 ± 0.01 and for myocardium/blood of 1.03 ± 0.02 in the eight swine, confirming that sufficient uniformity of proton density and T2* weightings exists among heterogeneous tissues of the heart. In the patients, the mean T1 bias ±1SD in myocardium and blood between T1-refBlochi and ShMOLLI was -9 ms ± 21 ms. T1-refBlochi provides a fast single-TI high resolution 3D T1 map of the heart with good accuracy and adequate precision.

  13. Common and uncommon features of focal splenic lesions on contrast-enhanced ultrasound: a pictorial review

    Energy Technology Data Exchange (ETDEWEB)

    Zavariz, Julia D., E-mail: julia.zavariz@hc.fm.usp.br [Universidade de São Paulo (HC/FMUSP), São Paulo, SP (Brazil). Faculdade de Medicina. Hospital das Clínicas; Konstantatou, Eleni; Deganello Annamaria; Bosanac, Diana; Huang, Dean Y.; Sellars, Maria E.; Sidhu, Paul S. [Department of Radiology, King’s College Hospital, Denmark Hill, London (United Kingdom)

    2017-11-15

    The characterization of focal splenic lesions by ultrasound can be quite challenging. The recent introduction of contrast-enhanced ultrasound (CEUS) has come to play a valuable role in the field of imaging splenic pathologies, offering the possibility of an ionizing radiation-free investigation. Because CEUS has been incorporated into everyday clinical practice, malignant diseases such as focal lymphomatous infiltration, metastatic deposits, benign cysts, traumatic fractures, and hemangiomas can now be accurately depicted and characterized without the need for further imaging. More specifically, splenic traumatic fractures do not require additional imaging by computed tomography (with ionizing radiation exposure) for follow-up, because splenic fractures and their complications are safely imaged with CEUS. In the new era of CEUS, more patients benefit from radiation-free investigation of splenic pathologies with high diagnostic accuracy. (author)

  14. Automated Detection of Healthy and Diseased Aortae from Images Obtained by Contrast-Enhanced CT Scan

    Directory of Open Access Journals (Sweden)

    Michael Gayhart

    2013-01-01

    Full Text Available Purpose. We developed the next stage of our computer assisted diagnosis (CAD system to aid radiologists in evaluating CT images for aortic disease by removing innocuous images and highlighting signs of aortic disease. Materials and Methods. Segmented data of patient’s contrast-enhanced CT scan was analyzed for aortic dissection and penetrating aortic ulcer (PAU. Aortic dissection was detected by checking for an abnormal shape of the aorta using edge oriented methods. PAU was recognized through abnormally high intensities with interest point operators. Results. The aortic dissection detection process had a sensitivity of 0.8218 and a specificity of 0.9907. The PAU detection process scored a sensitivity of 0.7587 and a specificity of 0.9700. Conclusion. The aortic dissection detection process and the PAU detection process were successful in removing innocuous images, but additional methods are necessary for improving recognition of images with aortic disease.

  15. Diagnosis of hepatic steatosis by contrast-enhanced abdominal computed tomography

    Directory of Open Access Journals (Sweden)

    Rodrigo da Fonseca Monjardim

    2013-06-01

    Full Text Available Objective To evaluate the diagnostic capacity of abdominal computed tomography in the assessment of hepatic steatosis using the portal phase with a simplified calculation method as compared with the non-contrast-enhanced phase. Materials and Methods In the present study, 150 patients were retrospectively evaluated by means of non-contrast-enhanced and contrast-enhanced computed tomography. One hundred patients had hepatic steatosis and 50 were control subjects. For the diagnosis of hepatic steatosis in the portal phase, the authors considered a result of < 104 HU calculated by the formula [L - 0.3 × (0.75 × P + 0.25 × A] / 0.7, where L, P and A represent the attenuation of the liver, of the main portal vein and abdominal aorta, respectively. Sensitivity, specificity, positive and negative predictive values were calculated, using non-contrast-enhanced computed tomography as the reference standard. Results The simplified calculation method with portal phase for the diagnosis of hepatic steatosis showed 100% sensitivity, 36% specificity, negative predictive value of 100% and positive predictive value of 75.8%. The rate of false positive results was 64%. False negative results were not observed. Conclusion The portal phase presents an excellent sensitivity in the diagnosis of hepatic steatosis, as compared with the non-contrast-enhanced phase of abdominal computed tomography. However, the method has low specificity.

  16. The clinical significance of persistent trigeminal nerve contrast enhancement in patients who undergo repeat radiosurgery.

    Science.gov (United States)

    Mousavi, Seyed H; Akpinar, Berkcan; Niranjan, Ajay; Agarwal, Vikas; Cohen, Jonathan; Flickinger, John C; Kondziolka, Douglas; Lunsford, L Dade

    2017-07-01

    OBJECTIVE Contrast enhancement of the retrogasserian trigeminal nerve on MRI scans frequently develops after radiosurgical ablation for the management of medically refractory trigeminal neuralgia (TN). The authors sought to evaluate the clinical significance of this imaging finding in patients who underwent a second radiosurgical procedure for recurrent TN. METHODS During a 22-year period, 360 patients underwent Gamma Knife stereotactic radiosurgery (SRS) as their first surgical procedure for TN at the authors' center. The authors retrospectively analyzed the data from 59 patients (mean age 72 years, range 33-89 years) who underwent repeat SRS for recurrent pain at a median of 30 months (range 6-146 months) after the first SRS. The isocenter was 4 mm, and the median maximum doses for the first and second procedures were 80 Gy and 70 Gy, respectively. A neuroradiologist and a neurosurgeon blinded to the treated side evaluated the presence of nerve contrast enhancement on MRI series at the time of the repeat procedure. The authors correlated the presence of this imaging change with clinical outcomes. Pain outcomes and development of trigeminal sensory dysfunction were evaluated with the Barrow Neurological Institute (BNI) Pain Scale and BNI Numbness Scale, respectively. The mean length of follow-up after the second SRS was 58 months (95% CI 49-68 months). RESULTS At the time of the repeat SRS, contrast enhancement of the trigeminal nerve on MRI scans was observed in 31 patients (53%). Five years after the SRS, patients with this enhancement had lower actuarial rates of complete pain relief after the repeat SRS (27% [95% CI 7%-47%]) than patients without the enhancement (76% [95% CI 58%-94%]) (p < 0.001). At the 5-year follow-up, patients with the contrast enhancement also had a higher risk for trigeminal sensory loss after repeat SRS (75% [95% CI 59%-91%]) than patients without contrast enhancement (26% [95% CI 10%-42%]) (p = 0.001). Dysesthetic pain after repeat SRS

  17. Comparison of contrast enhancement methods using photon counting detector in spectral mammography

    Science.gov (United States)

    Kim, Hyemi; Park, Su-Jin; Jo, Byungdu; Kim, Dohyeon; Kim, Hee-Joung

    2016-03-01

    The photon counting detector with energy discrimination capabilities provides the spectral information and energy of each photon with single exposure. The energy-resolved photon counting detector makes it possible to improve the visualization of contrast agent by selecting the appropriate energy window. In this study, we simulated the photon counting spectral mammography system using a Monte Carlo method and compared three contrast enhancement methods (K-edge imaging, projection-based energy weighting imaging, and dual energy subtraction imaging). For the quantitative comparison, we used the homogeneous cylindrical breast phantom as a reference and the heterogeneous XCAT breast phantom. To evaluate the K-edge imaging methods, we obtained images by increasing the energy window width based on K-edge absorption energy of iodine. The iodine which has the K-edge discontinuity in the attenuation coefficient curve can be separated from the background. The projection-based energy weighting factor was defined as the difference in the transmissions between the contrast agent and the background. Each weighting factor as a function of photon energy was calculated and applied to the each energy bin. For the dual energy subtraction imaging, we acquired two images with below and above the iodine K-edge energy using single exposure. To suppress the breast tissue in high energy images, the weighting factor was applied as the ratio of the linear attenuation coefficients of the breast tissue at high and low energies. Our results demonstrated the CNR improvement of the K-edge imaging was the highest among the three methods. These imaging techniques based on the energy-resolved photon counting detector improved image quality with the spectral information.

  18. Abdominal vascular and visceral parenchymal contrast enhancement in MDCT: Effects of injection duration

    Energy Technology Data Exchange (ETDEWEB)

    Tsuge, Yusuke, E-mail: tsugeu@cup.ocn.ne.jp [Department of Radiology, Kizawa Memorial Hospital, 590 Kobityo Shimokobi, Minokamo City, Gifu 505-8503 (Japan); Kanematsu, Masayuki [Department of Radiology, Gifu University Hospital, Gifu (Japan); Department of Radiology Services, Gifu University Hospital, Gifu (Japan); Goshima, Satoshi; Kondo, Hiroshi [Department of Radiology, Gifu University Hospital, Gifu (Japan); Yokoyama, Ryujiro; Miyoshi, Toshiharu [Department of Radiology Services, Gifu University Hospital, Gifu (Japan); Onozuka, Minoru [Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka (Japan); Moriyama, Noriyuki [Research Center for Cancer Prevention and Screening, National Cancer Center Hospital, Tsukiji (Japan); Bae, Kyongtae T. [Radiology and Biomedical Engineering, University of Pittsburgh, Pittsburgh, PA (United States)

    2011-11-15

    Purpose: To evaluate and compare the effect of short and long injection durations on aortic, pancreatic and hepatic enhancement in abdominal MDCT. Methods and materials: Triphasic contrast-enhanced CT images (16-MDCT, 1.25-mm collimation, 5-mm thickness, 6.1-s acquisition time for each phase) were obtained with 2 mL/kg injection of 300 mgI/mL iodine contrast material in 116 patients. Patients were prospectively randomized into two groups: one receiving contrast medium for 25-s injection duration and the other for 35-s injection duration. In both groups, triphasic scans were initiated 5, 15, and 40 s after the completion of contrast injection for the first, second and third phases, respectively. CT values (HU) in the abdominal aorta, liver, spleen, pancreas, splenic and superior mesenteric arteries, and veins (splenic, superior mesenteric, portal, and hepatic) were measured. Quantitative and qualitative analysis for the degree of contrast enhancement between the two groups in various organs was compared at each scan phase. Results: The aortic and arterial enhancements in the first-phase scan were higher for the 25-s group than those of the 35-s group (P < .001). Hepatic enhancement was higher for the 35-s group in the first (P < .001) and second (P < .01) phases, but no difference in the third-phase. No difference was found between the groups for the pancreatic enhancement at any phases. Qualitative results were in good agreement with quantitative results. Conclusion: Contrast administration with shorter injection duration increased peak aortic and arterial enhancement and contributed to improvement in the quality of CT angiograms, but for the solid abdominal organs 35-s protocol is recommended.

  19. Human visual system-based image enhancement and logarithmic contrast measure.

    Science.gov (United States)

    Panetta, Karen A; Wharton, Eric J; Agaian, Sos S

    2008-02-01

    Varying scene illumination poses many challenging problems for machine vision systems. One such issue is developing global enhancement methods that work effectively across the varying illumination. In this paper, we introduce two novel image enhancement algorithms: edge-preserving contrast enhancement, which is able to better preserve edge details while enhancing contrast in images with varying illumination, and a novel multihistogram equalization method which utilizes the human visual system (HVS) to segment the image, allowing a fast and efficient correction of nonuniform illumination. We then extend this HVS-based multihistogram equalization approach to create a general enhancement method that can utilize any combination of enhancement algorithms for an improved performance. Additionally, we propose new quantitative measures of image enhancement, called the logarithmic Michelson contrast measure (AME) and the logarithmic AME by entropy. Many image enhancement methods require selection of operating parameters, which are typically chosen using subjective methods, but these new measures allow for automated selection. We present experimental results for these methods and make a comparison against other leading algorithms.

  20. Early and Delayed Myocardial Enhancement in Myocardial Infarction Using Two-Phase Contrast-Enhanced Multidetector-Row CT

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Sung-Min; Kim, Young-Whan; Han, Seong-Wook [University of Keimyung College of Medicine, Dongsan Medical Center, Daegu (Korea, Republic of); Seo, Joon-Beom [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2007-04-15

    The purpose of this study was to describe the myocardial enhancement patterns in patients with myocardial infarction using two-phase contrast enhanced multidetector-row computed tomography (MDCT). Twenty-three patients with clinically proven myocardial infarction (17 acute myocardial infarction [AMI] and 6 chronic myocardial infarction [CMI]) were examined with two-phase contrast-enhanced ECG-gated MDCT. The presence, location, and patterns of myocardial enhancement on two phase MDCT images were compared with infarcted myocardial territories determined by using electrocardiogram, echocardiography, thallium-201 single photon emission computed tomography, catheter and MDCT coronary angiography. After clinical assessment, the presence of myocardial infarctions were found in 27 territories (19 AMI and 8 CMI) of 23 patients. Early perfusion defects were observed in 30 territories of all 23 patients. Three territories not corresponding to a myocardial infarction were detected in three patients with AMI and were associated with artifacts. Fourteen of perfusion defects were in the left anterior descending artery territory, four in the left circumflex artery territory, and nine in the right coronary artery territory. Delayed enhancement was observed in 25 territories (17 AMI and 8 CMI) of 21 patients. Delayed enhancement patterns were variable. Transmural early perfusion defects (n =12) were closely associated with transmural late enhancement (n = 5) and subendocardial residual defect with subepicardial late enhancement (n = 5). Myocardial infarction showed early perfusion defects and variable delayed enhancement patterns on two-phase contrast-enhanced MDCT. Delayed enhancement technique of MDCT could provide additional information of the location and extent of infarcted myocardium, and could be useful to plan appropriate therapeutic strategies in patients with AMI.

  1. Spleen evaluation using contrast enhanced ultrasonography and Doppler in dogs with subclinical ehrlichiosis

    Directory of Open Access Journals (Sweden)

    M.C. Maronezi

    2015-12-01

    Full Text Available The aim of this study was to evaluate the splenic parenchyma of dogs with subclinical ehrlichiosis using Doppler and contrast-enhanced ultrasonography and provide reference values for this organ in affected animals. Seventeen dogs naturally infected with E. canis were selected for this study. Splenic parenchyma echotexture and echogenicity, size and borders were determined by ultrasound scan. The vascular indices of the splenic artery were determined by Doppler. SonoVue, at 0.1mL per animal, was used in microbubble contrast-enhanced ultrasonography to determine wash in, wash out and peak enhancement time in the splenic tissue. B-mode ultrasonography revealed splenomegaly with rounded borders, heterogeneous echotexture and mixed echogenicity. The vascular indices of the splenic artery were: systolic velocity of 22.59±8.07cm/s, diastolic velocity of 5.25±4.66cm/s and resistance index of 0.71±0.14; values not yet reported in Veterinary Medicine. Contrast-enhanced ultrasonography recorded wash in time of 5.31±0.7s, peak enhancement time of 18.56±2.90s and wash out time of 94.56±35.21s. The combination of conventional ultrasonography of the spleen and hemodynamic evaluation by Doppler and contrast-enhanced ultrasonography is important for the diagnosis of canine ehrlichiosis and could help monitor the clinical evolution of subclinical cases.

  2. Contrast enhanced ultrasound for the diagnosis of liver hemangiomas - results of a Romanian multicentre study

    DEFF Research Database (Denmark)

    Sirli, Roxana; Sporea, Ioan; Săndulescu, Daniela Larisa

    2015-01-01

    BACKGROUND AND AIM: Contrast enhanced ultrasound (CEUS) has been proven to be a reliable method for the characterization of focal liver lesions (FLL). The aim of this paper was to evaluate the performance of CEUS for the diagnosis of liver hemangiomas in a large cohort of patients. MATERIAL...... for hemangioma if a typical pattern was present following contrast (centripetal fill in during the arterial phase, hyperenhanced lesion during venous and late phases). In all cases a reference method was available (contrast CT or MRI or biopsy). The trial was registered in clinicaltrials.gov (Identifier NCT......01329458). RESULTS: During February 2011 - May 2015, 1153 CEUS examinations were performed for the evaluation of de novo FLL. Out of the 1153 de novo FLL, 238 cases were diagnosed as hemangiomas by CEUS (typical enhancing pattern). Contrast CT/MRI and biopsy diagnosed additional 24 hemangiomas. From...

  3. Predicting IDH mutation status of intrahepatic cholangiocarcinomas based on contrast-enhanced CT features.

    Science.gov (United States)

    Zhu, Yong; Chen, Jun; Kong, Weiwei; Mao, Liang; Kong, Wentao; Zhou, Qun; Zhou, Zhengyang; Zhu, Bin; Wang, Zhongqiu; He, Jian; Qiu, Yudong

    2018-01-01

    To explore the difference in contrast-enhanced computed tomography (CT) features of intrahepatic cholangiocarcinomas (ICCs) with different isocitrate dehydrogenase (IDH) mutation status. Clinicopathological and contrast-enhanced CT features of 78 patients with 78 ICCs were retrospectively analysed and compared based on IDH mutation status. There were 11 ICCs with IDH mutation (11/78, 14.1%) and 67 ICCs without IDH mutation (67/78, 85.9%). IDH-mutated ICCs showed intratumoral artery more often than IDH-wild ICCs (p = 0.023). Most ICCs with IDH mutation showed rim and internal enhancement (10/11, 90.9%), while ICCs without IDH mutation often appeared diffuse (26/67, 38.8%) or with no enhancement (4/67, 6.0%) in the arterial phase (p = 0.009). IDH-mutated ICCs showed significantly higher CT values, enhancement degrees and enhancement ratios in arterial and portal venous phases than IDH-wild ICCs (all p IDH mutation, with an area under the curve of 0.798 (p = 0.002). ICCs with and without IDH mutation differed significantly in arterial enhancement mode, and the tumour enhancement degree on multiphase contrast-enhanced CT was helpful in predicting IDH mutation status. • IDH mutation occurred frequently in ICCs. • ICCs with and without IDH mutation differed significantly in arterial enhancement mode. • ICCs with IDH mutation enhanced more than those without IDH mutation. • Enhancement ratio and tumour CT value can predict IDH mutation status.

  4. Contrast medium-enhanced MRI findings and changes over time in stage I tuberculous meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Oztoprak, I. [Department of Radiology Cumhuriyet University Faculty of Medicine, 58140 Sivas (Turkey)], E-mail: oztoprak@cumhuriyet.edu.tr; Guemues, C.; Oztoprak, B. [Department of Radiology Cumhuriyet University Faculty of Medicine, 58140 Sivas (Turkey); Engin, A. [Department of Infectious Diseases, Cumhuriyet University Faculty of Medicine, Sivas (Turkey)

    2007-12-15

    Aim: To demonstrate the detailed imaging characteristics of early tuberculous meningitis (TBM) and changes over time on standard gadolinium-enhanced, T1-weighted magnetic resonance imaging (MRI) images. Materials and methods: Contrast-enhanced, T1-weighted, spin-echo MRI images of 26 patients with early TBM were evaluated retrospectively. Meningeal enhancement characteristics were categorized according to distribution and pattern as diffuse, focal, linear, nodular, and mixed. Results: We found that 35% of patients had diffuse meningeal enhancement and 65% of cases had focal meningeal enhancement. There was a predilection for focal meningeal enhancement in basal pial areas, the interpeduncular fossa being the most common. In six patients with diffuse meningeal enhancement admitted to hospital relatively early after the onset of symptoms, the type of meningeal enhancement later changed to the focal form. Conclusion: Reactive diffuse meningeal enhancement occurs in the early period of TBM on contrast medium-enhanced T1-weighted MR images, but later becomes limited to basal areas.

  5. Diagnostic accuracy of contrast-enhanced ultrasound for characterization of kidney lesions in patients with and without chronic kidney disease.

    Science.gov (United States)

    Chang, Emily Hueywen; Chong, Wui Kheong; Kasoji, Sandeep Kumar; Fielding, Julia Rose; Altun, Ersan; Mullin, Lee B; Kim, Jung In; Fine, Jason Peter; Dayton, Paul Alexander; Rathmell, Wendy Kimryn

    2017-08-09

    Patients with chronic kidney disease are at increased risk of cystic kidney disease that requires imaging monitoring in many cases. However, these same patients often have contraindications to contrast-enhanced computed tomography and magnetic resonance imaging. This study evaluates the accuracy of contrast-enhanced ultrasound (CEUS), which is safe for patients with chronic kidney disease, for the characterization of kidney lesions in patients with and without chronic kidney disease. We performed CEUS on 44 patients, both with and without chronic kidney disease, with indeterminate or suspicious kidney lesions (both cystic and solid). Two masked radiologists categorized lesions using CEUS images according to contrast-enhanced ultrasound adapted criteria. CEUS designation was compared to histology or follow-up imaging in cases without available tissue in all patients and the subset with chronic kidney disease to determine sensitivity, specificity and overall accuracy. Across all patients, CEUS had a sensitivity of 96% (95% CI: 84%, 99%) and specificity of 50% (95% CI: 32%, 68%) for detecting malignancy. Among patients with chronic kidney disease, CEUS sensitivity was 90% (95% CI: 56%, 98%), and specificity was 55% (95% CI: 36%, 73%). CEUS has high sensitivity for identifying malignancy of kidney lesions. However, because specificity is low, modifications to the classification scheme for contrast-enhanced ultrasound could be considered as a way to improve contrast-enhanced ultrasound specificity and thus overall performance. Due to its sensitivity, among patients with chronic kidney disease or other contrast contraindications, CEUS has potential as an imaging test to rule out malignancy. This trial was registered in clinicaltrials.gov, NCT01751529 .

  6. Comparison of arterial input functions measured from ultra-fast dynamic contrast enhanced MRI and dynamic contrast enhanced computed tomography in prostate cancer patients

    Science.gov (United States)

    Wang, Shiyang; Lu, Zhengfeng; Fan, Xiaobing; Medved, Milica; Jiang, Xia; Sammet, Steffen; Yousuf, Ambereen; Pineda, Federico; Oto, Aytekin; Karczmar, Gregory S.

    2018-02-01

    The purpose of this study was to evaluate the accuracy of arterial input functions (AIFs) measured from dynamic contrast enhanced (DCE) MRI following a low dose of contrast media injection. The AIFs measured from DCE computed tomography (CT) were used as ‘gold standard’. A total of twenty patients received CT and MRI scans on the same day. Patients received 120 ml Iohexol in DCE-CT and a low dose of (0.015 mM kg‑1) of gadobenate dimeglumine in DCE-MRI. The AIFs were measured in the iliac artery and normalized to the CT and MRI contrast agent doses. To correct for different temporal resolution and sampling periods of CT and MRI, an empirical mathematical model (EMM) was used to fit the AIFs first. Then numerical AIFs (AIFCT and AIFMRI) were calculated based on fitting parameters. The AIFMRI was convolved with a ‘contrast agent injection’ function (AIFMRICON ) to correct for the difference between MRI and CT contrast agent injection times (~1.5 s versus 30 s). The results show that the EMMs accurately fitted AIFs measured from CT and MRI. There was no significant difference (p  >  0.05) between the maximum peak amplitude of AIFs from CT (22.1  ±  4.1 mM/dose) and MRI after convolution (22.3  ±  5.2 mM/dose). The shapes of the AIFCT and AIFMRICON were very similar. Our results demonstrated that AIFs can be accurately measured by MRI following low dose contrast agent injection.

  7. Anatomical variation of thyroid veins on contrast-enhanced multi-detector row computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Hayato, E-mail: m04149@yahoo.co.jp [Department of Radiology, St. Marianna University School of Medicine, Yokohama City Seibu Hospital, 1197-1 Yasashicho, Asahi-ku, Yokohama, Kanagawa 241-0811 (Japan); Yamada, Takayuki; Murakami, Kenji; Hashimoto, Kazuki; Tazawa, Yoko; Kumano, Reiko [Department of Radiology, St. Marianna University School of Medicine, Yokohama City Seibu Hospital, 1197-1 Yasashicho, Asahi-ku, Yokohama, Kanagawa 241-0811 (Japan); Nakajima, Yasuo [Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511 (Japan)

    2015-05-15

    Highlights: • This is the first study to demonstrate the anatomy of thyroid veins on contrasted-enhanced MDCT. • Identifying the thyroid vein on MDCT prior to selective venous sampling of parathyroid hormone provides clinical information to interventional radiologist. • Detecting especially the inferior thyroid veins with individual variability in numbers, locations, and lengths may have an effect on SVS for HPT and decrease the difficulty and time of the procedure. - Abstract: Objective: The objective of this study was to clarify the anatomical variation of thyroid veins into the systemic vein using contrast-enhanced multi-detector row computed tomography (MDCT). Design and methods: : The subjects were 80 patients (34 males and 46 females; mean age, 50.1 years; age range, 15–92 years) with neck diseases who underwent MDCT. The number and location of inflow points of the thyroid veins into the systemic vein, and the length from the junction of bilateral brachiocephalic veins to the orifice of inferior thyroid vein were investigated by reviewing the axial and coronal images. Results: All superior thyroid veins were detected. Right and left middle thyroid veins were identified in 39 and 29 patients, respectively. Right inferior thyroid veins, left inferior thyroid veins, and common trunks were detected in 43, 46, and 39 patients, respectively; in five patients, two left thyroid veins were identified. All left inferior thyroid veins and 34 common trunks flowed into the innominate vein, while right ones had some variations in inflow sites. Mean lengths were 3.01 ± 1.30 cm (range, 0.5–6.19) and 2.04 ± 0.91 cm (0.5–4.4) in the left inferior thyroid vein and common trunk, and 1.96 ± 1.05 cm (0.81–4.8) and 1.65 ± 0.69 cm (0.63–2.94) in the right one flowing into the right internal jugular vein and the innominate vein, respectively. Conclusions: The numbers and orifices of thyroid veins were identified at high rates on contrast-enhanced MDCT. This

  8. CT contrast enhancement following renal cryoablation – artefact or treatment failure?

    DEFF Research Database (Denmark)

    Nielsen, Tommy Kjærgaard; Østraat, Øyvind; Andersen, Gratien

    Introduction and objective: Renal cryoablation is a valid treatment option for localized pT1a renal cancer. Treatment success is typically defined as absence of contrast enhancement (CE) and a decrease in size of the cryoablated renal mass (i.e. cryolesion) on follow-up imaging. We investigated...... (LCA) or percutaneous cryoablation (PCA) from August 2005 to August 2012 at Aarhus University Hospital. Six patients were excluded from analysis due to MRI follow-up. During routine postoperative CT follow-up, contrast enhancement of the cryolesion was identified in 34 of the 107 patients (32......, PADUA- score and level of contrast enhancement was significantly (penhancement pattern and number of cryoprobes used were not significantly different between the two groups. In patients where...

  9. The clinical use of contrast-enhanced ultrasound in the kidney.

    Science.gov (United States)

    Tenant, Sean C; Gutteridge, Catherine M

    2016-05-01

    Traditional B-Mode and Doppler sonography have been the stalwart of renal tract imaging for many years, and indeed, are in daily use in most centres as the modality of choice for the initial assessment of renal pathology. However, traditional ultrasound scanning can be limited in its ability to accurately characterise renal pathology, and can be inaccurate at determining benign from malignant lesions. Contrast-enhanced ultrasound conveys many benefits, being safe (especially in patients with renal dysfunction), does not require the use of ionising radiation, is quick and relatively cheap and can help to establish whether a focal renal lesion is sinister. Furthermore, it is our experience that contrast-enhanced ultrasound is not a difficult technique to master for the experienced ultrasound practitioner. In this article, we discuss the technique, interpretation and value of contrast-enhanced ultrasound in renal imaging, and describe how we use it in our practice.

  10. Intravenous contrast-enhanced sonography in children and adolescents – a single center experience

    Directory of Open Access Journals (Sweden)

    Martin Stenzel

    2013-06-01

    Full Text Available Compared to adult patients, ultrasonography in children and adolescents is much more common, due to lack of ionizing radiation, and its wide availability. With the introduction of contrast-media for use in ultrasonography, one major drawback of the method could be overcome. In Europe, SonoVue® is the only widely available agent, which due to improved stability makes it possible to image normal and diseased tissue perfusion and vascularization with high accuracy. Inability to hold the breath and voluntary body movement of the patient is less of an obstacle compared to color Doppler techniques and makes the method very attractive for use in children, which, depending on age, may not be very cooperative. Use of intravenous contrast-medium in minors is currently very limited for several reasons: availability, lack of recommendation in national and international guidelines, and lack of official licensing. The article will touch medical indications, technique, safety considerations, and perspective of intravenous use of contrast-media in children and adolescents, including data from a 6-year period in 37 patients. Purpose: The purpose of the study was to collect data on ultrasonographic examinations, expanded by intravenous administration of the contrast agent SonoVue® in children and adolescents. Besides assessing diagnostic yield, data on adverse medication effects was collected. Materials and methods: The study includes contrast-enhanced ultrasound examinations in 37 children at a single institution. Indications for the examinations were tumor lesions, infections, traumatic organ injuries, and parenchymal organ ischemia. Parents of the patients and adolescent patients were informed about the off-label use of the contrast agent. Thirty-nine examinations were performed, the average age of the patient was 11.1 years (range 1 7/ 12 to 17 11/ 12 years. Results: All of the examinations yielded additional diagnostic value, always expanding results

  11. High Contrast Imaging of Exoplanets and Exoplanetary Systems with JWST

    Science.gov (United States)

    Hinkley, Sasha; Skemer, Andrew; Biller, Beth; Baraffe, I.; Bonnefoy, M.; Bowler, B.; Carter, A.; Chen, C.; Choquet, E.; Currie, T.; Danielski, C.; Fortney, J.; Grady, C.; Greenbaum, A.; Hines, D.; Janson, M.; Kalas, P.; Kennedy, G.; Kraus, A.; Lagrange, A.; Liu, M.; Marley, M.; Marois, C.; Matthews, B.; Mawet, D.; Metchev, S.; Meyer, M.; Millar-Blanchaer, M.; Perrin, M.; Pueyo, L.; Quanz, S.; Rameau, J.; Rodigas, T.; Sallum, S.; Sargent, B.; Schlieder, J.; Schneider, G.; Stapelfeldt, K.; Tremblin, P.; Vigan, A.; Ygouf, M.

    2017-11-01

    JWST will transform our ability to characterize directly imaged planets and circumstellar debris disks, including the first spectroscopic characterization of directly imaged exoplanets at wavelengths beyond 5 microns, providing a powerful diagnostic of cloud particle properties, atmospheric structure, and composition. To lay the groundwork for these science goals, we propose a 39-hour ERS program to rapidly establish optimal strategies for JWST high contrast imaging. We will acquire: a) coronagraphic imaging of a newly discovered exoplanet companion, and a well-studied circumstellar debris disk with NIRCam & MIRI; b) spectroscopy of a wide separation planetary mass companion with NIRSPEC & MIRI; and c) deep aperture masking interferometry with NIRISS. Our primary goals are to: 1) generate representative datasets in modes to be commonly used by the exoplanet and disk imaging communities; 2) deliver science enabling products to empower a broad user base to develop successful future investigations; and 3) carry out breakthrough science by characterizing exoplanets for the first time over their full spectral range from 2-28 microns, and debris disk spectrophotometry out to 15 microns sampling the 3 micron water ice feature. Our team represents the majority of the community dedicated to exoplanet and disk imaging and has decades of experience with high contrast imaging algorithms and pipelines. We have developed a collaboration management plan and several organized working groups to ensure we can rapidly and effectively deliver high quality Science Enabling Products to the community.

  12. Concentric circular focusing reflector realized using high index contrast gratings

    Science.gov (United States)

    Fang, Wenjing; Huang, Yongqing; Fei, Jiarui; Duan, Xiaofeng; Liu, Kai; Ren, Xiaomin

    2017-11-01

    A non-periodic concentric circular high index contrast grating (CC-HCG) focusing reflector on 500 nm silicon-on-insulator (SOI) platform is fabricated and experimentally demonstrated. The proposed mirror is realized with phase modulation of wave front in a high reflectivity region. The circular structure based HCG focusing reflector has a spot of high concentration at the 10.87 mm with normal incidence for radially polarization, along with the center wavelength set at 1550 nm. The FWHM spot size of the focusing beam decreases to 260 μm, and the intensity increases to 1.26 compared with the incident beam. The focusing efficiency of about 80% is observed at 1550 nm in the experimental measurement.

  13. 1060-nm Tunable Monolithic High Index Contrast Subwavelength Grating VCSEL

    DEFF Research Database (Denmark)

    Ansbæk, Thor; Chung, Il-Sug; Semenova, Elizaveta

    2013-01-01

    We present the first tunable vertical-cavity surface-emitting laser (VCSEL) where the top distributed Bragg reflector has been completely substituted by an air-cladded high-index-contrast subwavelength grating (HCG) mirror. In this way, an extended cavity design can be realized by reducing...... the reflection at the semiconductor #x2013;air interface using an anti-reflective coating (ARC). We demonstrate how the ARC can be integrated in a monolithic structure by oxidizing AlGaAs with high Al-content. The HCG VCSEL has the potential to achieve polarization stable single-mode output with high tuning...... efficiency. The HCG VCSEL shows a total tuning range of 16 nm around an emission wavelength of 1060 nm with 1-mW output power....

  14. Contrast-enhanced Voiding Urosonography for Vesicoureteral Reflux Diagnosis in Children.

    Science.gov (United States)

    Duran, Carmina; Beltrán, Viviana P; González, Amàlia; Gómez, Carles; Riego, Javier Del

    2017-10-01

    Contrast-enhanced voiding urosonography (ceVUS) is a dynamic imaging technique that makes it possible to study the structure of the urinary tract after the administration of intravesical contrast material. Initially, ceVUS was indicated mainly to study vesicoureteral reflux (VUR); however, since the ability of ceVUS to depict the structure of the urethra was demonstrated in both sexes, ceVUS is now indicated for examination of the entire urinary tract. The main benefit of ceVUS is that it does not use ionizing radiation. In recent years, fundamental changes have occurred in the understanding of VUR. The lessening effect of VUR and the low rate of occurrence of urethral pathologic conditions have given rise to changes in the indications for tests for these conditions. In addition to being able to help confirm a diagnosis of VUR, the ceVUS technique can be used to depict obstructive and nonobstructive urethral pathologic conditions, as well as normal variants, on high-quality images. Furthermore, ceVUS enables real-time assessment of voiding function. For these reasons, ceVUS should be not only an alternative to voiding cystourethrography, but also the technique of choice for the study of the entire urinary tract in pediatric patients. Online supplemental material is available for this article. ©RSNA, 2017.

  15. Enhanced tumor contrast during breast lumpectomy provided by independent component analysis of localized reflectance measures

    Science.gov (United States)

    Eguizabal, Alma; Laughney, Ashley M.; Garcia Allende, Pilar Beatriz; Krishnaswamy, Venkataramanan; Wells, Wendy A.; Paulsen, Keith D.; Pogue, Brian W.; Lopez-Higuera, Jose M.; Conde, Olga M.

    2012-03-01

    A spectral analysis technique to enhance tumor contrast during breast conserving surgery is proposed. A set of 29 surgically-excised breast tissues have been imaged in local reflectance geometry. Measures of broadband reflectance are directly analyzed using Principle Component Analysis (PCA), on a per sample basis, to extract areas of maximal spectral variation. A dynamic selection threshold has been applied to obtain the final number of principal components, accounting for inter-patient variability. A blind separation technique based on Independent Component Analysis (ICA) is then applied to extract diagnostically powerful results. ICA application reveals that the behavior of one independent component highly correlates with the pathologic diagnosis and it surpasses the contrast obtained using empirical models. Moreover, blind detection characteristics (no training, no comparisons with training reference data) and no need for parameterization makes the automated diagnosis simple and time efficient, favoring its translation to the clinical practice. Correlation coefficient with model-based results up to 0.91 has been achieved.

  16. Enhancement of Low Contrast Images Based on Effective Space Combined with Pixel Learning

    Directory of Open Access Journals (Sweden)

    Gengfei Li

    2017-11-01

    Full Text Available Images captured in bad conditions often suffer from low contrast. In this paper, we proposed a simple, but efficient linear restoration model to enhance the low contrast images. The model’s design is based on the effective space of the 3D surface graph of the image. Effective space is defined as the minimum space containing the 3D surface graph of the image, and the proportion of the pixel value in the effective space is considered to reflect the details of images. The bright channel prior and the dark channel prior are used to estimate the effective space, however, they may cause block artifacts. We designed the pixel learning to solve this problem. Pixel learning takes the input image as the training example and the low frequency component of input as the label to learn (pixel by pixel based on the look-up table model. The proposed method is very fast and can restore a high-quality image with fine details. The experimental results on a variety of images captured in bad conditions, such as nonuniform light, night, hazy and underwater, demonstrate the effectiveness and efficiency of the proposed method.

  17. Diagnostic accuracy of segmental enhancement inversion for diagnosis of renal oncocytoma at biphasic contrast enhanced CT: systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Schieda, Nicola; McInnes, Matthew D.F.; Cao, Lilly [Ottawa Hospital Research Institute, Department of Medical Imaging, Ottawa, ON (Canada)

    2014-06-15

    To use systematic review to evaluate the diagnostic accuracy of segmental enhancement inversion (SEI) at contrast-enhanced biphasic multi-detector computed tomography (MDCT) for the diagnosis of renal oncocytoma. Several electronic databases were searched through October 2013. Two reviewers independently selected studies that met the inclusion criteria and extracted data. Study quality was assessed with the QUADAS-2 tool. The primary 2 x 2 data were investigated with forest plot and ROC plot of sensitivity and specificity. Four studies met the inclusion criteria (307 patients). Considerable heterogeneity between studies precluded meta-analysis. Two studies from the same group of investigators demonstrated reasonable diagnostic accuracy (sensitivity 59-80 % and specificity 87-99 %), while two others did not (sensitivity 0-6 %, specificity 93-100 %). Possible reasons for this include timing of biphasic MDCT and methods of interpretation but not size of lesion. SEI is a specific imaging finding of renal oncocytoma with highly variable sensitivity. This substantial heterogeneity across studies and between institutions suggests that further validation of this imaging finding is necessary prior to application in clinical practice. (orig.)

  18. Single-layer and dual-layer contrast-enhanced mammography using amorphous selenium flat panel detectors.

    Science.gov (United States)

    Allec, N; Abbaszadeh, S; Karim, K S

    2011-09-21

    The accumulation of injected contrast agents allows the image enhancement of lesions through the use of contrast-enhanced mammography. In this technique, the combination of two acquired images is used to create an enhanced image. There exist several methods to acquire the images to be combined, which include dual energy subtraction using a single detection layer that suffers from motion artifacts due to patient motion between image acquisition. To mitigate motion artifacts, a detector composed of two layers may be used to simultaneously acquire the low and high energy images. In this work, we evaluate both of these methods using amorphous selenium as the detection material to find the system parameters (tube voltage, filtration, photoconductor thickness and relative intensity ratio) leading to the optimal performance. We then compare the performance of the two detectors under the variation of contrast agent concentration, tumor size and dose. The detectability was found to be most comparable at the lower end of the evaluated factors. The single-layer detector not only led to better contrast, due to its greater spectral separation capabilities, but also had lower quantum noise. The single-layer detector was found to have a greater detectability by a factor of 2.4 for a 2.5 mm radius tumor having a contrast agent concentration of 1.5 mg ml(-1) in a 4.5 cm thick 50% glandular breast. The inclusion of motion artifacts in the comparison is part of ongoing research efforts.

  19. Thermal enhancement of AFM phase contrast for imaging diblock copolymer thin film morphology.

    Science.gov (United States)

    Fasolk, M J; Mayes, A M; Magonov, N

    2001-11-01

    A simple and effective means of increasing the morphological detail in AFM phase micrographs of microphase separated block copolymer films is presented. Effective AFM phase imaging of microphase separated systems hinges upon the existence of appropriate contrast mechanisms such as differences in elasticity between the microphase separated domains. For some systems, AFM phase imaging at room temperature results in low contrast images due to a paucity of differential mechanical behavior between the microphase domains, e.g. at room temperature both species are glassy. Through the use of a heating apparatus custom-designed for AFM, an elastic contrast mechanism can be created in some systems by raising the specimen to a temperature between the glass transitions of the constituent polymer species. This serves to preferentially soften one species with respect to the other, thus enhancing the phase contrast mechanism, which results in micrographs with superior detail. This simple technique is demonstrated using films of a series of polystyrene-b-poly(n-alkyl methacrylate) diblock copolymers and both commercial and custom-built heating stages. By choosing appropriate measurement temperatures, AFM phase contrast could be greatly enhanced, or indeed created, when compared to room temperature images of these specimens. For these materials, contrast enhancement required that the sample be heated roughly 20 degrees C above the glass transition of the lower-Tg species.

  20. SU-E-T-56: Brain Metastasis Treatment Plans for Contrast-Enhanced Synchrotron Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Obeid, L; Adam, J [Grenoble Institut des Neurosciences, La Tronche, Rhone-Alpes (France); Tessier, A [Centre Hospitalier Universitaire, La Tronche, Rhone-Alpes (France); Vautrin, M; Benkebil, M [DOSIsoft, Cachan, Ile de France (France); Sihanath, R [Centre Hospitalier Universitaire, La Tronche, Rhone- Alpes (France)

    2014-06-01

    Purpose: Iodine-enhanced radiotherapy is an innovative treatment combining the selective accumulation of an iodinated contrast agent in brain tumors with irradiations using monochromatic medium energy x-rays. The aim of this study is to compare dynamic stereotactic arc-therapy and iodineenhanced SSRT. Methods: Five patients bearing brain metastasis received a standard helical 3D-scan without iodine. A second scan was acquired 13 min after an 80 g iodine infusion. Two SSRT treatment plans (with/without iodine) were performed for each patient using a dedicated Monte Carlo (MC) treatment planning system (TPS) based on the ISOgray TPS. Ten coplanar beams (6×6 cm2, shaped with collimator) were simulated. MC statistical error objective was less than 5% in the 50% isodose. The dynamic arc-therapy plan was achieved on the Iplan Brainlab TPS. The treatment plan validation criteria were fixed such that 100% of the prescribed dose is delivered at the beam isocentre and the 70% isodose contains the whole target volume. The comparison elements were the 70% isodose volume, the average and maximum doses delivered to organs at risk (OAR): brainstem, optical nerves, chiasma, eyes, skull bone and healthy brain parenchyma. Results: The stereotactic dynamic arc-therapy remains the best technique in terms of dose conformation. Iodine-enhanced SSRT presents similar performances to dynamic arc-therapy with increased brainstem and brain parenchyma sparing. One disadvantage of SSRT is the high dose to the skull bone. Iodine accumulation in metastasis may increase the dose by 20–30%, allowing a normal tissue sparing effect at constant prescribed dose. Treatment without any iodine enhancement (medium-energy stereotactic radiotherapy) is not relevant with degraded HDVs (brain, parenchyma and skull bone) comparing to stereotactic dynamic arc-therapy. Conclusion: Iodine-enhanced SSRT exhibits a good potential for brain metastasis treatment regarding the dose distribution and OAR criteria.

  1. Dynamic contrast-enhanced breast MRI at 7 Tesla utilizing a single-loop coil: a feasibility trial.

    Science.gov (United States)

    Umutlu, Lale; Maderwald, Stefan; Kraff, Oliver; Theysohn, Jens M; Kuemmel, Sherko; Hauth, Elke A; Forsting, Michael; Antoch, Gerald; Ladd, Mark E; Quick, Harald H; Lauenstein, Thomas C

    2010-08-01

    The aim of this study was to assess the feasibility of dynamic contrast-enhanced ultra-high-field breast imaging at 7 Tesla. A total of 15 subjects, including 5 patients with histologically proven breast cancer, were examined on a 7 Tesla whole-body magnetic resonance imaging system using a unilateral linearly polarized single-loop coil. Subjects were placed in prone position on a biopsy support system, with the coil placed directly below the region of interest. The examination protocol included the following sequences: 1) T2-weighted turbo spin echo sequence; 2) six dynamic T1-weighted spoiled gradient-echo sequences; and 3) subtraction imaging. Contrast-enhanced T1-weighted imaging at 7 Tesla could be obtained at high spatial resolution with short acquisition times, providing good image accuracy and a conclusively good delineation of small anatomical and pathological structures. T2-weighted imaging could be obtained with high spatial resolution at adequate acquisition times. Because of coil limitations, four high-field magnetic resonance examinations showed decreased diagnostic value. This first scientific approach of dynamic contrast-enhanced breast magnetic resonance imaging at 7 Tesla demonstrates the complexity of ultra-high-field breast magnetic resonance imaging and countenances the implementation of further advanced bilateral coil concepts to circumvent current limitations from the coil and ultra-high-field magnetic strength. 2010 AUR. Published by Elsevier Inc. All rights reserved.

  2. Contrast-enhanced ultrasonographic findings in three dogs with pancreatic insulinoma.

    Science.gov (United States)

    Nakamura, Kensuke; Lim, Sue-Yee; Ochiai, Kenji; Yamasaki, Masahiro; Ohta, Hiroshi; Morishita, Keitaro; Takagi, Satoshi; Takiguchi, Mitsuyoshi

    2015-01-01

    Abdominal ultrasonography is one of the most common diagnostic imaging modalities used for dogs with suspected insulinoma; however, pancreatic masses are clearly identified in fewer than half of affected dogs and benign pancreatic nodules can be difficult to differentiate from malignant ones. The purpose of this prospective study was to describe contrast-enhanced ultrasonography (CEUS) characteristics of confirmed pancreatic insulinoma in a group of dogs. Inclusion criteria were as follows: (1) repeated hypoglycemia (blood glucose levels ultrasonography; and (4) histological confirmation of pancreatic islet cell carcinoma. Immediately following conventional ultrasonography of the entire abdomen, CEUS of the pancreatic nodule and adjacent parenchyma was performed using contrast-specific technology pulse inversion imaging and perflubutane microbubble contrast agent. Three dogs met inclusion criteria. Pancreatic nodules in all the three dogs became more clearly demarcated after injection of the contrast agent. Each nodule showed different enhancement patterns: markedly hyperechoic for 5 s, slightly hyperechoic for 1 s, and clearly hypoechoic for over 30 s. These results were not in complete agreement with previously reported CEUS findings in human patients with insulinoma. All nodules were surgically resected and histopathologically confirmed as malignant insulinomas. Findings from the current study indicated that contrast-enhanced ultrasound may help to increase conspicuity of pancreatic insulinomas in dogs and that enhancement characteristics may be more variable in dogs than in humans. © 2014 American College of Veterinary Radiology.

  3. Facing Contrast-Enhancing Gliomas: Perfusion MRI in Grade III and Grade IV Gliomas according to Tumor Area

    Directory of Open Access Journals (Sweden)

    Anna Luisa Di Stefano

    2014-01-01

    Full Text Available Tumoral neoangiogenesis characterizes high grade gliomas. Relative Cerebral Blood Volume (rCBV, calculated with Dynamic Susceptibility Contrast (DSC Perfusion-Weighted Imaging (PWI, allows for the estimation of vascular density over the tumor bed. The aim of the study was to characterize putative tumoral neoangiogenesis via the study of maximal rCBV with a Region of Interest (ROI approach in three tumor areas—the contrast-enhancing area, the nonenhancing tumor, and the high perfusion area on CBV map—in patients affected by contrast-enhancing glioma (grades III and IV. Twenty-one patients were included: 15 were affected by grade IV and 6 by grade III glioma. Maximal rCBV values for each patient were averaged according to glioma grade. Although rCBV from contrast-enhancement and from nonenhancing tumor areas was higher in grade IV glioma than in grade III (5.58 and 2.68; 3.01 and 2.2, resp., the differences were not significant. Instead, rCBV recorded in the high perfusion area on CBV map, independently of tumor compartment, was significantly higher in grade IV glioma than in grade III (7.51 versus 3.78, P=0.036. In conclusion, neoangiogenesis encompasses different tumor compartments and CBV maps appear capable of best characterizing the degree of neovascularization. Facing contrast-enhancing brain tumors, areas of high perfusion on CBV maps should be considered as the reference areas to be targeted for glioma grading.

  4. Adrenal glands in hypovolemic shock: preservation of contrast enhancement at dynamic computed tomography.

    Science.gov (United States)

    Ito, Katsuyoshi; Higashi, Hiroki; Kanki, Akihiko; Tamada, Tsutomu; Yamashita, Takenori; Yamamoto, Akira; Watanabe, Shigeru

    2010-07-01

    To evaluate contrast enhancement effects of the adrenal glands at dynamic computed tomography (CT) in adult severe trauma patients with hypovolemic shock in comparison with patients without hypovolemic shock. This study population included a total of 74 patients with (n = 24) and without (n = 50) blunt trauma and hypovolemic shock. Measurement of CT attenuation values of the adrenal gland and calculation of the enhancement washout percentages were performed. The mean +/- SD CT attenuation values of the adrenal glands in the arterial phase of dynamic CT in patients with hypovolemic shock (137.3 +/- 41.7 Hounsfield unit [HU]) were not significantly different (P = 0.16) from those in control subjects (127.3 +/- 19.6 HU). The mean CT attenuation values of the adrenal glands in the delayed phase of dynamic CT in patients with hypovolemic shock (82.0 +/- 14.7 HU) were also not significantly different (P = 0.89) from those in control subjects (82.4 +/- 10.0 HU). The mean percentage (35%) of enhancement washout of the adrenal glands in patients with hypovolemic shock was not significantly different (P = 0.81) from that (34%) in control subjects. Contrast enhancement effects of the adrenal glands at contrast-enhanced dynamic CT in patients with hypovolemic shock were similar to those in control subjects, indicating the preserved enhancement and perfusion of the adrenal gland rather than intense and persistent enhancement in patients with hypovolemic shock.

  5. Application of contrast-enhanced ultrasound after liver transplantation: Current status and perspectives.

    Science.gov (United States)

    Ren, Jie; Wu, Tao; Zheng, Bo-Wen; Tan, Ying-Yi; Zheng, Rong-Qin; Chen, Gui-Hua

    2016-01-28

    Liver transplantation is an effective treatment for patients with end-stage liver disease. Accurate imaging evaluation of the transplanted patient is critical for ensuring that the limited donor liver is functioning appropriately. Ultrasound contrast agents (UCAs), in combination with contrast-specific imaging techniques, are increasingly accepted in clinical use for the assessment of the hepatic vasculature, bile ducts and liver parenchyma in pre-, intra- and post-transplant patients. We describe UCAs, their technical requirements, the recommended clinical indications, image interpretation and the limitations for contrast-enhanced ultrasound applications in liver transplantation.

  6. Hepatic blood perfusion estimated by dynamic contrast-enhanced computed tomography in pigs

    DEFF Research Database (Denmark)

    Winterdahl, Michael; Sørensen, Michael; Keiding, Inger Susanne

    2012-01-01

    The aim of this study was to determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from the hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates.......The aim of this study was to determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from the hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates....

  7. Contrast Enhancement on CT Following Renal Cryoablation – Does It Represent Treatment Failure?

    DEFF Research Database (Denmark)

    Nielsen, Tommy Kjærgaard; Østraat, Øyvind; Andersen, Gratien

    Aim: Renal cryoablation is a valid treatment option for localized pT1a renal cancer. Treatment success is typically defined as absence of contrast enhancement (CE) on follow-up imaging. We investigate the development of lesions that demonstrate CE on follow-up CT after renal cryoablation. Materials...... not uncommon. As there are no clear-cut criteria for monitoring treatment failure, careful evaluation by an experienced radiologist and urologist is recommend. The significance of delayed contrast enhancement is not clearly evident and needs further investigation....

  8. Practical method and device for enhancing pulse contrast ratio for lasers and electron accelerators

    Science.gov (United States)

    Zhang, Shukui; Wilson, Guy

    2014-09-23

    An apparatus and method for enhancing pulse contrast ratios for drive lasers and electron accelerators. The invention comprises a mechanical dual-shutter system wherein the shutters are placed sequentially in series in a laser beam path. Each shutter of the dual shutter system has an individually operated trigger for opening and closing the shutter. As the triggers are operated individually, the delay between opening and closing first shutter and opening and closing the second shutter is variable providing for variable differential time windows and enhancement of pulse contrast ratio.

  9. A perceptually oriented method for contrast enhancement and segmentation of dermoscopy images.

    Science.gov (United States)

    Abbas, Qaisar; Garcia, Irene Fondón; Emre Celebi, M; Ahmad, Waqar; Mushtaq, Qaisar

    2013-02-01

    Dermoscopy images often suffer from low contrast caused by different light conditions, which reduces the accuracy of lesion border detection. Accordingly for lesion recognition, automatic melanoma border detection (MBD) is an initial as well as crucial task. In this article, a novel perceptually oriented approach for MBD is presented by combing region and edge-based segmentation techniques. The MBD system for color contrast and segmentation improvement consists of four main steps: first, the RGB dermoscopy image is transformed to CIE L*a*b* color space, lesion contrast is then enhanced by adjusting and mapping the intensity values of the lesion pixels in the specified range using the three channels of CIE L*a*b*, a hill-climbing algorithm is used later to detect region-of-interest (ROI) map in a perceptually oriented color space using color channels (L*,a*,b*) and finally, an adaptive thresholding is applied to determine the optimal lesion border. Manually drawn borders obtained from an experienced dermatologist are utilized as a ground truth for performance evaluation. The proposed MBD method is tested on a total of 100 dermoscopy images. A comparative study with three state-of-the-art color and texture-based segmentation techniques (JSeg, dermatologists-like tumor area extraction: DTEA and region-based active contours: RAC), is also conducted to show the effectiveness of our MBD method using measures of true positive rate (TPR), false positive rate (FPR), and error probability (EP). Among different algorithms, our MBD algorithm achieved TPR of 94.25%, FPR of 3.56%, and EP of 4%. The proposed MBD approach is highly accurate to detect the lesion border area. The MBD software and sample of dermoscopy images can be downloaded at http://cs.ntu.edu.pk/research.php. © 2012 John Wiley & Sons A/S.

  10. Contrast-enhanced spectral mammography with a photon-counting detector.

    Science.gov (United States)

    Fredenberg, Erik; Hemmendorff, Magnus; Cederström, Björn; Aslund, Magnus; Danielsson, Mats

    2010-05-01

    Spectral imaging is a method in medical x-ray imaging to extract information about the object constituents by the material-specific energy dependence of x-ray attenuation. The authors have investigated a photon-counting spectral imaging system with two energy bins for contrast-enhanced mammography. System optimization and the potential benefit compared to conventional non-energy-resolved absorption imaging was studied. A framework for system characterization was set up that included quantum and anatomical noise and a theoretical model of the system was benchmarked to phantom measurements. Optimal combination of the energy-resolved images corresponded approximately to minimization of the anatomical noise, which is commonly referred to as energy subtraction. In that case, an ideal-observer detectability index could be improved close to 50% compared to absorption imaging in the phantom study. Optimization with respect to the signal-to-quantum-noise ratio, commonly referred to as energy weighting, yielded only a minute improvement. In a simulation of a clinically more realistic case, spectral imaging was predicted to perform approximately 30% better than absorption imaging for an average glandularity breast with an average level of anatomical noise. For dense breast tissue and a high level of anatomical noise, however, a rise in detectability by a factor of 6 was predicted. Another approximately 70%-90% improvement was found to be within reach for an optimized system. Contrast-enhanced spectral mammography is feasible and beneficial with the current system, and there is room for additional improvements. Inclusion of anatomical noise is essential for optimizing spectral imaging systems.

  11. Anatomical variation of thyroid veins on contrast-enhanced multi-detector row computed tomography.

    Science.gov (United States)

    Tomita, Hayato; Yamada, Takayuki; Murakami, Kenji; Hashimoto, Kazuki; Tazawa, Yoko; Kumano, Reiko; Nakajima, Yasuo

    2015-05-01

    The objective of this study was to clarify the anatomical variation of thyroid veins into the systemic vein using contrast-enhanced multi-detector row computed tomography (MDCT). The subjects were 80 patients (34 males and 46 females; mean age, 50.1 years; age range, 15-92 years) with neck diseases who underwent MDCT. The number and location of inflow points of the thyroid veins into the systemic vein, and the length from the junction of bilateral brachiocephalic veins to the orifice of inferior thyroid vein were investigated by reviewing the axial and coronal images. All superior thyroid veins were detected. Right and left middle thyroid veins were identified in 39 and 29 patients, respectively. Right inferior thyroid veins, left inferior thyroid veins, and common trunks were detected in 43, 46, and 39 patients, respectively; in five patients, two left thyroid veins were identified. All left inferior thyroid veins and 34 common trunks flowed into the innominate vein, while right ones had some variations in inflow sites. Mean lengths were 3.01±1.30 cm (range, 0.5-6.19) and 2.04±0.91 cm (0.5-4.4) in the left inferior thyroid vein and common trunk, and 1.96±1.05 cm (0.81-4.8) and 1.65±0.69 cm (0.63-2.94) in the right one flowing into the right internal jugular vein and the innominate vein, respectively. The numbers and orifices of thyroid veins were identified at high rates on contrast-enhanced MDCT. This strategy can provide anatomical information before selective venous sampling for measurements of parathyroid hormone. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Pulmonary Arterial Hypertension: Use of Delayed Contrast-Enhanced Cardiovascular Magnetic Resonance in Risk Assessment

    Science.gov (United States)

    Bessa, Luiz Gustavo Pignataro; Junqueira, Flávia Pegado; Bandeira, Marcelo Luiz da Silva; Garcia, Marcelo Iorio; Xavier, Sérgio Salles; Lavall, Guilherme; Torres, Diego; Waetge, Daniel

    2013-01-01

    Background Pulmonary arterial hypertension is a severe and progressive disease. Its early diagnosis is the greatest clinical challenge. Objective To evaluate the presence and extension of the delayed myocardial contrast-enhanced cardiovascular magnetic resonance, as well as to verify if the percentage of the myocardial fibrosis mass is a severity predictor. Methods Cross-sectional study with 30 patients with pulmonary arterial hypertension of groups I and IV, subjected to clinical, functional and hemodynamic evaluation, and to cardiac magnetic resonance. Results The mean age of patients was 52 years old, with female predominance (77%). Among the patients, 53% had right ventricular failure at diagnosis, and 90% were in functional class II/III. The mean of the 6-minute walk test was 395m. In hemodynamic study with right catheterism, the mean average pulmonary arterial pressure was 53.3mmHg, of the cardiac index of 2.1L/ min.m2, and median right atrial pressure was 13.5 mmHg. Delayed myocardial contrast enhanced cardiovascular magnetic resonance was found in 28 patients. The mean fibrosis mass was 9.9 g and the median percentage of fibrosis mass was 6.17%. The presence of functional class IV, right ventricular failure at diagnosis, 6-minute walk test < 300 meters and right atrial pressure ≥ 15 mmHg, with cardiac index < 2.0 L/ min.m2, there was a relevant association with the increased percentage of myocardial fibrosis. Conclusion The percentage of the myocardial fibrosis mass indicates a non-invasive marker with promising perspectives in identifying patients with high risk factors for pulmonary hypertension. PMID:23979779

  13. Pulmonary Arterial Hypertension: Use of Delayed Contrast-Enhanced Cardiovascular Magnetic Resonance in Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Bessa, Luiz Gustavo Pignataro, E-mail: lgpignataro@ig.com.br; Junqueira, Flávia Pegado; Bandeira, Marcelo Luiz da Silva; Garcia, Marcelo Iorio; Xavier, Sérgio Salles; Lavall, Guilherme; Torres, Diego; Waetge, Daniel [Hospital Universitário Clementino Fraga Filho, Ilha do Fundão, RJ (Brazil)

    2013-10-15

    Pulmonary arterial hypertension is a severe and progressive disease. Its early diagnosis is the greatest clinical challenge. To evaluate the presence and extension of the delayed myocardial contrast-enhanced cardiovascular magnetic resonance, as well as to verify if the percentage of the myocardial fibrosis mass is a severity predictor. Cross-sectional study with 30 patients with pulmonary arterial hypertension of groups I and IV, subjected to clinical, functional and hemodynamic evaluation, and to cardiac magnetic resonance. The mean age of patients was 52 years old, with female predominance (77%). Among the patients, 53% had right ventricular failure at diagnosis, and 90% were in functional class II/III. The mean of the 6-minute walk test was 395m. In hemodynamic study with right catheterism, the mean average pulmonary arterial pressure was 53.3mmHg, of the cardiac index of 2.1L/ min.m{sup 2}, and median right atrial pressure was 13.5 mmHg. Delayed myocardial contrast enhanced cardiovascular magnetic resonance was found in 28 patients. The mean fibrosis mass was 9.9 g and the median percentage of fibrosis mass was 6.17%. The presence of functional class IV, right ventricular failure at diagnosis, 6-minute walk test < 300 meters and right atrial pressure ≥ 15 mmHg, with cardiac index < 2.0 L/ min.m{sup 2}, there was a relevant association with the increased percentage of myocardial fibrosis. The percentage of the myocardial fibrosis mass indicates a non-invasive marker with promising perspectives in identifying patients with high risk factors for pulmonary hypertension.

  14. Clinical usefulness of contrast-enhanced MP-RAGE of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Hauwe, L. van den [Department of Radiology, Universitair Ziekenhuis Antwerpen, Wilrijkstraat 10, B-2650 Edegem (Belgium); Parizel, P.M. [Department of Radiology, Universitair Ziekenhuis Antwerpen, Wilrijkstraat 10, B-2650 Edegem (Belgium); Goethem, J.W. van [Department of Radiology, Universitair Ziekenhuis Antwerpen, Wilrijkstraat 10, B-2650 Edegem (Belgium); Schepper, A.M.A. de [Department of Radiology, Universitair Ziekenhuis Antwerpen, Wilrijkstraat 10, B-2650 Edegem (Belgium)

    1996-05-01

    Our purpose was to evaluate the usefulness of a 3D T1-weighted gradient-echo sequence (MP-RAGE) in clinical practice. We prospectively examined 200 patients with a variety of neurological disorders and symptoms. We compared lesion conspicuity and contrast enhancement on MP-RAGE images with conventional gadolinium-enhanced spin-echo (SE) T1-weighted images. Both the original MP-RAGE data and the reformatted images were characterised by improved differentiation between grey and white matter. More lesions were found on the 3D series, in both patients with neoplastic and non-neoplastic disease. Contrast enhancement of small oedematous lesions affecting the white matter in demyelinating disease was less obvious. Multiplanar reformatting, which can be realised in any desired plane and surface rendering with sophisticated segmentation algorithms superbly displayed the underlying anatomical relationships between lesions and normal brain structures. Excellent spatial resolution, the absence of posterior fossa artefacts and equivalent contrast enhancement resulted in an increased number of space-occupying lesions being found on the MP-RAGE images. Thus contrast-enhanced MP-RAGE is an alternative to conventional SE imaging in the investigation of intracranial masses. Although the total number of lesions found in patients with demyelinating disease was significantly higher on MP-RAGE, demonstration of blood-brain-barrier breakdown in active lesions was less obvious. (orig.). With 5 figs., 2 tabs.

  15. Moderate Contrast in the Evaluation of Paintings Is Liked More but Remembered Less than High Contrast

    OpenAIRE

    Katinka Dijkstra; Noah N. N. van Dongen

    2017-01-01

    Many visual aspects of paintings, as well as exposure to art and cultural norms, contribute to the aesthetic evaluation of paintings. The current study looked at heightened visual contrast as an important factor in the appreciation of paintings. Participants evaluated abstract digitized paintings that were manipulated in contrast for an appreciation task and were later presented with these paintings in a memory task. The results indicated that for art appreciation, a moderate increase in cont...

  16. Use of computational fluid dynamics in the design of dynamic contrast enhanced imaging phantoms.

    Science.gov (United States)

    Hariharan, Prasanna; Freed, Melanie; Myers, Matthew R

    2013-09-21

    Phantoms for dynamic contrast enhanced (DCE) imaging modalities such as DCE computed tomography (DCE-CT) and DCE magnetic resonance imaging (DCE-MRI) are valuable tools for evaluating and comparing imaging systems. It is important for the contrast-agent distribution within the phantom to possess a time dependence that replicates a curve observed clinically, known as the 'tumor-enhancement curve'. It is also important for the concentration field within the lesion to be as uniform as possible. This study demonstrates how computational fluid dynamics (CFD) can be applied to achieve these goals within design constraints. The distribution of the contrast agent within the simulated phantoms was investigated in relation to the influence of three factors of the phantom design. First, the interaction between the inlets and the uniformity of the contrast agent within the phantom was modeled. Second, pumps were programmed using a variety of schemes and the resultant dynamic uptake curves were compared to tumor-enhancement curves obtained from clinical data. Third, the effectiveness of pulsing the inlet flow rate to produce faster equilibration of the contrast-agent distribution was quantified. The models employed a spherical lesion and design constraints (lesion diameter, inlet-tube size and orientation, contrast-agent flow rates and fluid properties) taken from a recently published DCE-MRI phantom study. For DCE-MRI in breast cancer detection, where the target tumor-enhancement curve varies on the scale of hundreds of seconds, optimizing the number of inlet tubes and their orientation was found to be adequate for attaining concentration uniformity and reproducing the target tumor-enhancement curve. For DCE-CT in liver tumor detection, where the tumor-enhancement curve varies on a scale of tens of seconds, the use of an iterated inlet condition (programmed into the pump) enabled the phantom to reproduce the target tumor-enhancement curve within a few per cent beyond about 6

  17. An evaluation of the clinical diagnostic value of contrast-enhanced ultrasound combined with contrast-enhanced computed tomography in space-occupying lesions of the kidney

    Directory of Open Access Journals (Sweden)

    Tian W

    2017-07-01

    Full Text Available Wen Tian,1 Jianbo Lu,2 Dan Jiao,3 Zhibin Cong2 1Department of Blood Transfusion, The Second Hospital of Jilin University, 2Department of Ultrasound, Affiliated Hospital of Changchun University of Traditional Chinese Medicine, 3Department of Ultrasound, China-Japan Union Hospital of Jilin University, Changchun, Jilin, People’s Republic of China Background: There are a variety of space-occupying lesions of the kidney, and the benign lesions may be difficult to differentiate from the malignant ones. Therefore, an accurate judgment of the benign and malignant nature of the space-occupying lesions of the kidney is of high importance for the treatment and prognosis of these patients.Objective: To evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS combined with contrast-enhanced computed tomography (CECT in space-occupying lesions of the kidney.Data and methods: Three hundred and sixty-seven patients with space-occupying lesions of the kidney (378 lesions were examined by CEUS and CECT, respectively, then, a combined diagnosis was made after the combination of CEUS and CECT by a multidisciplinary team. The diagnoses from the three methods were compared. The pathological results were taken as the gold standard. The sensitivity, specificity, positive and negative predictive values and area under the receiver operating characteristic (ROC curve were calculated for the three methods. Thus, the diagnostic value of the three methods was assessed.Results: Of the 378 lesions examined, there were 301 malignant lesions and 77 benign lesions. The combined examination revealed 303 malignant lesions, with 9 benign lesions mistakenly diagnosed as malignant ones; thus, the misdiagnosis rate was 11.7%. By using the combined examination, 75 benign lesions were diagnosed, with the missed diagnosis of 7 malignant lesions, so the missed diagnosis rate was 2.3%. The sensitivity, specificity, positive and negative predictive values and area under the ROC

  18. Multi-wavelength VCSEL arrays using high-contrast gratings

    Science.gov (United States)

    Haglund, Erik; Gustavsson, Johan S.; Sorin, Wayne V.; Bengtsson, Jörgen; Fattal, David; Haglund, Àsa; Tan, Michael; Larsson, Anders

    2017-02-01

    The use of a high-contrast grating (HCG) as the top mirror in a vertical-cavity surface-emitting laser (VCSEL) allows for setting the resonance wavelength by the grating parameters in a post-epitaxial growth fabrication process. Using this technique, we demonstrate electrically driven multi-wavelength VCSEL arrays at 980 nm wavelength. The VCSELs are GaAs-based and the suspended GaAs HCGs were fabricated using electron-beam lithography, dry etching and selective removal of an InGaP sacrificial layer. The air-coupled cavity design enabled 4-channel arrays with 5 nm wavelength spacing and sub-mA threshold currents thanks to the high HCG reflectance.

  19. Impact of model-based iterative reconstruction on image quality of contrast-enhanced neck CT.

    Science.gov (United States)

    Gaddikeri, S; Andre, J B; Benjert, J; Hippe, D S; Anzai, Y

    2015-02-01

    Improved image quality is clinically desired for contrast-enhanced CT of the neck. We compared 30% adaptive statistical iterative reconstruction and model-based iterative reconstruction algorithms for the assessment of image quality of contrast-enhanced CT of the neck. Neck contrast-enhanced CT data from 64 consecutive patients were reconstructed retrospectively by using 30% adaptive statistical iterative reconstruction and model-based iterative reconstruction. Objective image quality was assessed by comparing SNR, contrast-to-noise ratio, and background noise at levels 1 (mandible) and 2 (superior mediastinum). Two independent blinded readers subjectively graded the image quality on a scale of 1-5, (grade 5 = excellent image quality without artifacts and grade 1 = nondiagnostic image quality with significant artifacts). The percentage of agreement and disagreement between the 2 readers was assessed. Compared with 30% adaptive statistical iterative reconstruction, model-based iterative reconstruction significantly improved the SNR and contrast-to-noise ratio at levels 1 and 2. Model-based iterative reconstruction also decreased background noise at level 1 (P = .016), though there was no difference at level 2 (P = .61). Model-based iterative reconstruction was scored higher than 30% adaptive statistical iterative reconstruction by both reviewers at the nasopharynx (P iterative reconstruction. Model-based iterative reconstruction offers improved subjective and objective image quality as evidenced by a higher SNR and contrast-to-noise ratio and lower background noise within the same dataset for contrast-enhanced neck CT. Model-based iterative reconstruction has the potential to reduce the radiation dose while maintaining the image quality, with a minor downside being prominent artifacts related to thyroid shield use on model-based iterative reconstruction. © 2015 by American Journal of Neuroradiology.

  20. Contrast-enhanced postmortem computed tomography in clinical pathology: enhanced value of 20 clinical autopsies.

    Science.gov (United States)

    Westphal, Saskia E; Apitzsch, Jonas C; Penzkofer, Tobias; Kuhl, Christiane K; Mahnken, Andreas H; Knüchel, Ruth

    2014-09-01

    Postmortem computed tomography (PMCT) is a modern tool that complements autopsy diagnostics. In clinical autopsies, a major cause of death is cardiovascular disease. To improve the performance of PMCT in cardiovascular disease, full body angiography was developed (PMCT angiography [PMCTA]). Twenty PMCTA scans generated before autopsy were compared with native PMCT and clinical autopsy. The objective of the study was to quantify the additional diagnostic value of adding angiography to native imaging and to compare PMCT and PMCTA findings to autopsy findings. The diagnosis of the cause of death was identical or overlapped in 80% of the cases that used PMCTA and 70% that used PMCT. The additional diagnostic yield given by PMCT and PMCTA in combination with autopsy was 55%. PMCT yielded additional diagnoses in the musculoskeletal system. The greatest additional diagnostic value of PMCTA was in association with cardiovascular diagnoses. The accuracy of PMCTA for cardiac causes of death was 80%, and the positive predictive value was 90%. The findings indicate that native PMCT cannot display the cardiovascular system sufficiently clearly for high-quality diagnostic assessment. However, PMCTA is a powerful tool in autopsy cases with a history of cardiovascular disease and/or a suspected cardiovascular cause of death. The combination of PMCTA and clinical autopsy enhances diagnostic quality and completeness of the autopsy report. Furthermore, in cases without consent or with a restricted consent for clinical autopsy, PMCTA has the potential to provide information on cardiovascular causes of death. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Use of contrast-enhanced ultrasonography in chronic pathologic canine testes

    OpenAIRE

    Volta, A.; Manfredi, S; Vignoli, M.; Russo, M.; England, G. C. W.; Rossi, F; Bigliardi, E.; Di Ianni, F.; Parmigiani, E; Bresciani, C.; Gnudi, G.

    2014-01-01

    Contrast-enhanced ultrasound with sulphur hexafluoride microbubbles was performed in seven healthy dogs without a history of reproductive pathology and with histologically confirmed normal testes and in 42 dogs with chronic scrotal anomalies. All dogs underwent orchiectomy and histological examination. Enhancement patterns and perfusion parameters (peak intensity and regional blood flow) of testes of healthy dogs and testes with chronic lesions were compared. Fourteen non-pathologic and 60 pa...

  2. Local gray level S-curve transformation - A generalized contrast enhancement technique for medical images.

    Science.gov (United States)

    Gandhamal, Akash; Talbar, Sanjay; Gajre, Suhas; Hani, Ahmad Fadzil M; Kumar, Dileep

    2017-04-01

    Most medical images suffer from inadequate contrast and brightness, which leads to blurred or weak edges (low contrast) between adjacent tissues resulting in poor segmentation and errors in classification of tissues. Thus, contrast enhancement to improve visual information is extremely important in the development of computational approaches for obtaining quantitative measurements from medical images. In this research, a contrast enhancement algorithm that applies gray-level S-curve transformation technique locally in medical images obtained from various modalities is investigated. The S-curve transformation is an extended gray level transformation technique that results into a curve similar to a sigmoid function through a pixel to pixel transformation. This curve essentially increases the difference between minimum and maximum gray values and the image gradient, locally thereby, strengthening edges between adjacent tissues. The performance of the proposed technique is determined by measuring several parameters namely, edge content (improvement in image gradient), enhancement measure (degree of contrast enhancement), absolute mean brightness error (luminance distortion caused by the enhancement), and feature similarity index measure (preservation of the original image features). Based on medical image datasets comprising 1937 images from various modalities such as ultrasound, mammograms, fluorescent images, fundus, X-ray radiographs and MR images, it is found that the local gray-level S-curve transformation outperforms existing techniques in terms of improved contrast and brightness, resulting in clear and strong edges between adjacent tissues. The proposed technique can be used as a preprocessing tool for effective segmentation and classification of tissue structures in medical images. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Quantitative dynamic contrast-enhanced MR imaging analysis of complex adnexal masses: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Thomassin-Naggara, Isabelle [Hopital Tenon, Assistance Publique-Hopitaux de Paris, Department of Radiology, Paris (France); Laboratoire de recherche en imagerie - UMR 970 INSERM - Universite Rene Descartes, Paris (France); Service de Radiologie, Hopital Tenon, Paris (France); Balvay, Daniel [Laboratoire de recherche en imagerie - UMR 970 INSERM - Universite Rene Descartes, Paris (France); Aubert, Emilie; Bazot, Marc [Hopital Tenon, Assistance Publique-Hopitaux de Paris, Department of Radiology, Paris (France); Darai, Emile; Rouzier, Roman [Hopital Tenon, Assistance Publique-Hopitaux de Paris, Department of Gynaecology-Obstetrics, Paris (France); Cuenod, Charles A. [Laboratoire de recherche en imagerie - UMR 970 INSERM - Universite Rene Descartes, Paris (France); Hopital Europeen Georges Pompidou (HEGP), Department of Radiology, Paris (France)

    2012-04-15

    To evaluate the ability of quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to differentiate malignant from benign adnexal tumours. Fifty-six women with 38 malignant and 18 benign tumours underwent MR imaging before surgery for complex adnexal masses. Microvascular parameters were extracted from high temporal resolution DCE-MRI series, using a pharmacokinetic model in the solid tissue of adnexal tumours. These parameters were tissue blood flow (F{sub T}), blood volume fraction (Vb), permeability-surface area product (PS), interstitial volume fraction (Ve), lag time (Dt) and area under the enhancing curve (rAUC). Area under the receiver operating curve (AUROC) was calculated as a descriptive tool to assess the overall discrimination of parameters. Malignant tumours displayed higher F{sub T}, Vb, rAUC and lower Ve than benign tumours (P < 0.0001, P = 0.0006, P = 0.04 and P = 0.0002, respectively). F{sub T} was the most relevant factor for discriminating malignant from benign tumours (AUROC = 0.86). Primary ovarian invasive tumours displayed higher F{sub T} and shorter Dt than borderline tumours. Malignant adnexal tumours with associated peritoneal carcinomatosis at surgery displayed a shorter Dt than those without peritoneal carcinomatosis at surgery (P = 0.01). Quantitative DCE-MRI is a feasible and accurate technique to differentiate malignant from benign adnexal tumours and could potentially help oncologists with management decisions. (orig.)

  4. Application of contrast-enhanced ultrasonography in the diagnosis of skeletal muscle crush injury in rabbits

    Science.gov (United States)

    Zhang, C-D; Lv, F-Q; Li, Q-Y; Zhang, Y; Shi, X-Q; Li, X-Y

    2014-01-01

    Objective: To explore the diagnostic value of quantitative contrast-enhanced (CE) ultrasonography for crush injury in the hind limb muscles of rabbits. Methods: A total of 120 New Zealand white rabbits were randomized to receive compression on the left hind limb for either 2 h (n = 56) or 4 h (n = 56) to induce muscle crush injury. Another eight animals were not injured and served as normal controls. CE ultrasonography parameters such as peak intensity (PI), ascending slop, descending slop and area under curve (AUC) were measured at 0.5, 2, 6 and 24 h and 3, 7 and 14 days after decompression. Results: Compared with the uninjured muscles, reperfusion of the injured muscles showed early and high enhancement in CE ultrasonography images. The time-intensity curve showed a trend of rapid lift and gradual drop. The PI and AUC values differed significantly among the three groups and were positively correlated with serum and tissue biomarkers. Rabbits of the 4-h compression group showed significantly higher PI and AUC values, and serum and tissue parameters than the 2-h compression group at each time points. Conclusion: CE ultrasonography can effectively detect muscle crush injury and monitor dynamic changes of the injured muscles in rabbits. PI and AUC are promising diagnostic parameters for this disease. Advances in knowledge: CE ultrasonography might play an important role in the pre-hospital and bedside settings for the diagnosis of muscle crush injury. PMID:25026985

  5. Contrast-enhanced harmonic endoscopic ultrasound imaging: basic principles, present situation and future perspectives.

    Science.gov (United States)

    Alvarez-Sánchez, María-Victoria; Napoléon, Bertrand

    2014-11-14

    Over the last decade, the development of stabilised microbubble contrast agents and improvements in available ultrasonic equipment, such as harmonic imaging, have enabled us to display microbubble enhancements on a greyscale with optimal contrast and spatial resolution. Recent technological advances made contrast harmonic technology available for endoscopic ultrasound (EUS) for the first time in 2008. Thus, the evaluation of microcirculation is now feasible with EUS, prompting the evolution of contrast-enhanced EUS from vascular imaging to images of the perfused tissue. Although the relevant experience is still preliminary, several reports have highlighted contrast-enhanced harmonic EUS (CH-EUS) as a promising noninvasive method to visualise and characterise lesions and to differentiate benign from malignant focal lesions. Even if histology remains the gold standard, the combination of CH-EUS and EUS fine needle aspiration (EUS-FNA) can not only render EUS more accurate but may also assist physicians in making decisions when EUS-FNA is inconclusive, increasing the yield of EUS-FNA by guiding the puncture with simultaneous imaging of the vascularity. The development of CH-EUS has also opened up exciting possibilities in other research areas, including monitoring responses to anticancer chemotherapy or to ethanol-induced pancreatic tissue ablation, anticancer therapies based on ultrasound-triggered drug and gene delivery, and therapeutic adjuvants by contrast ultrasound-induced apoptosis. Contrast harmonic imaging is gaining popularity because of its efficacy, simplicity and non-invasive nature, and many expectations are currently resting on this technique. If its potential is confirmed in the near future, contrast harmonic imaging will become a standard practice in EUS.

  6. Within-lesion differences in quantitative MRI parameters predict contrast enhancement in multiple sclerosis.

    Science.gov (United States)

    Jurcoane, Alina; Wagner, Marlies; Schmidt, Christoph; Mayer, Christoph; Gracien, Rene-Maxime; Hirschmann, Marc; Deichmann, Ralf; Volz, Steffen; Ziemann, Ulf; Hattingen, Elke

    2013-12-01

    To investigate the relationship between quantitative magnetic resonance imaging (qMRI) and contrast enhancement in multiple sclerosis (MS) lesions. We compared maps of T1 relaxation time, proton density (PD), and magnetization transfer ratio (MTR) between lesions with and without contrast enhancement as quantified by the amount of T1 shortening postcontrast agent (CA). In 17 patients with relapsing-remitting MS (RRMS), 15 with progressive MS (PMS), and 17 healthy controls, T1, PD, and MTR were measured at 3T and T1-mapping was repeated after CA administration. Manually drawn MS-lesions (3D-FLAIR) were labeled as enhancing if post-CA T1-shortening exceeded mean T1-shortening in normal-appearing white matter (NAWM) by at least 2 standard deviations. Precontrast T1, PD, and MTR were compared in enhancing lesions, nonenhancing lesions, NAWM, and gray matter. Precontrast T1, PD, and MTR differed significantly between enhancing and nonenhancing lesions in RRMS and PMS patients (all P T1 of gray matter differed significantly from RRMS and controls. Only MTR of gray matter differed between RRMS and controls. Contrast enhancement in MS quantified by relative T1 shortening may be predicted by precontrast abnormalities of T1, PD, and MTR and likely represents blood-brain barrier damage. Copyright © 2013 Wiley Periodicals, Inc.

  7. Clinical study of contrast-enhanced digital mammography and the evaluation of blood and lymphatic microvessel density.

    Science.gov (United States)

    Brandan, María-Ester; Cruz-Bastida, Juan P; Rosado-Méndez, Iván M; Villaseñor-Navarro, Yolanda; Pérez-Ponce, Héctor; Galván, Héctor A; Trujillo-Zamudio, Flavio E; Sánchez-Suárez, Patricia; Benítez-Bribiesca, Luis

    2016-09-01

    To correlate image parameters in contrast-enhanced digital mammography (CEDM) with blood and lymphatic microvessel density (MVD). 18 Breast Imaging-Reporting and Data System (BI-RADS)-4 to BI-RADS-5 patients were subjected to CEDM. Craniocaudal views were acquired, two views (low and high energy) before iodine contrast medium (CM) injection and four views (high energy) 1-5 min afterwards. Processing included registration and two subtraction modalities, traditional single-energy temporal (high-energy) and "dual-energy temporal with a matrix", proposed to improve lesion conspicuity. Images were calibrated into iodine thickness, and iodine uptake, contrast, time-intensity and time-contrast kinetic curves were quantified. Image indicators were compared with MVD evaluated by anti-CD105 and anti-podoplanin (D2-40) immunohistochemistry. 11 lesions were cancerous and 7 were benign. CEDM subtraction strongly increased conspicuity of lesions enhanced by iodine uptake. A strong correlation was observed between lymphatic vessels and blood vessels; all benign lesions had contrast. The most frequent curve was early uptake followed by plateau for uptake and contrast in benign and malignant lesions. The positive-predictive value of uptake dynamics was 73% and that of contrast was 64%. CEDM increased lesion visibility and showed additional features compared with conventional mammography. Lack of correlation between image parameters and MVD is probably due to tumour tissue heterogeneity, mammography projective nature and/or dependence of extracellular iodine irrigation on tissue composition. Quantitative analysis of CEDM images was performed. Image parameters and MVD showed no correlation. Probably, this is indication of the complex dependence of CM perfusion on tumour microenvironment.

  8. [Evaluation of imaging parameters for T1 dynamic contrast enhanced MRI with fast spin-echo].

    Science.gov (United States)

    Kanazawa, Yuuki; Miyati, Tosiaki; Inoue, Yusuke; Sato, Osamu

    2007-10-20

    For the purpose of continual measurement of the T1 value using the FSE (fast spin-echo) sequence and evaluation of the hemodynamics, we assessed T1 values when the imaging parameters were changed. Moreover, with the imaging parameters derived from this study, dynamic contrast-enhanced MR imaging (MRI) was examined in prostatic disease. First, the T1 value before contrast agent injection was measured with imaging parameters that had different TR and fixed TE. Next, dynamic contrast-enhanced imaging data were acquired for the imaging parameters using TE and TR in the same way as before contrast agent injection, and the T1 value of the tissue at contrast enhancement was measured. In the phantom studies, the TSE imaging parameters with short TE, long TR, and few ETL were connected with the mixed sequence. In dynamic study of the prostate, the difference between normal prostate and prostate cancer became clearer with the time-relaxation rate curve than the time-signal curve. This method using TSE is able to evaluate in greater detail information on hemodynamics and to perform dynamic study with the spin-echo sequence in extensive tissues.

  9. Meta-analysis: Serum creatinine changes following contrast enhanced CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kooiman, Judith, E-mail: j.kooiman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Pasha, Sharif M., E-mail: s.m.pasha@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Zondag, Wendy, E-mail: w.zondag@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Sijpkens, Yvo W.J., E-mail: ysijpens@bronovo.nl [Department of Nephrology, Bronovo Hospital, The Hague (Netherlands); Molen, Aart J. van der, E-mail: molen@lumc.nl [Department of Radiology, LUMC, Leiden (Netherlands); Huisman, Menno V., E-mail: m.v.huisman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Dekkers, Olaf M., E-mail: o.m.dekkers@lumc.nl [Department of Clinical Epidemiology and Department of Endocrinology, LUMC, Leiden (Netherlands)

    2012-10-15

    Purpose: Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN. Materials and methods: A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach. Results: Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0–8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01–0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6–2.1%). Patients with chronic kidney disease (odds ratio 2.26, p < 0.001) or diabetes mellitus (odds ratio 3.10, p < 0.001) were at increased risk for the development of CIN. Conclusion: CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted.

  10. Contrast-enhanced ultrasonography to assess blood perfusion of skeletal muscles in normal dogs.

    Science.gov (United States)

    Oh, Juyeon; Jeon, Sunghoon; Choi, Jihye

    2015-07-01

    This study evaluated perfusion of skeletal muscle using contrast enhanced ultrasonography in humerus, radius, femur and tibia in normal dogs. Contrast enhanced ultrasonography for each region was performed after injecting 0.5 mL and 1 mL of contrast medium (SonoVue) in every dog. Blood perfusion was assessed quantitatively by measuring the peak intensity, time to the peak intensity and area under the curve from the time-intensity curve. Vascularization in skeletal muscle was qualitatively graded with a score of 0-3 according to the number of vascular signals. A parabolic shape of time-intensity curve was observed from muscles in normal dogs, and time to the peak intensity, the peak intensity and area under the curve of each muscle were not significantly different according to the appendicular regions examined and the dosage of contrast agent administered. This study reports that feasibility of contrast enhanced ultrasonography for assessment of the muscular perfusion in canine appendicular regions.

  11. Technical aspects of contrast-enhanced magnetic resonance imaging of the breast: literature review; Aspectos tecnicos da ressonancia magnetica de mama com meio de contraste: revisao da literatura

    Energy Technology Data Exchange (ETDEWEB)

    Leopoldino, Denise de Deus; Gracio, Tatiana Schiller [Hospital Sao Luiz, Sao Paulo, SP (Brazil). Setor de Tomografia e Ressonancia Magnetica]. E-mail: leopoldinod@yahoo.com; D' Ippolito, Giuseppe; Bezerra, Alexandre Sergio de Araujo; Gracio, Tatiana Schiller [Hospital Sao Luiz, Sao Paulo, SP (Brazil). Setor de Diagnostico por Imagem

    2005-07-15

    With the advances in surface coil technology and the development of new imaging protocols in addition to the increase of the use of contrast agents, contrast enhanced magnetic resonance imaging (MRI) has emerged as a promising modality for detection, diagnosis and staging of breast cancer. Despite these advances, there are some unresolved issues, including no defined standard technique for contrast-enhanced breast MRI and no standard criteria of interpretation for the evaluation of such studies. In this article, we review the literature and discuss the general requirements and recommendations for contrast agent-enhanced breast MRI, including image interpretation criteria, MR equipment, dedicated radiofrequency coils, use of paramagnetic contrast agents, fat-suppression techniques, planes of acquisition, pulse sequence specifications and artifact sources. (author)

  12. Automatic hyperspectral camera for latent fingerprint detection and contrast enhancement. Final report, September 2, 1998 - March 17, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Paul Shnitser

    1999-06-01

    Physical Optics Corporation demonstrated the feasibility of the contrast enhancement of the latent fingerprint by portable hyperspectral imaging camera. The demonstrated non-contact technology is applicable for observation of the low contrast laser excited fluorescence from latent fingerprints as well as for the contrast enhancement of chemically processed fingerprints. Experiments were conducted with fingerprints on various types of substrates.

  13. Comparison of gadolinium nanoparticles and molecular contrast agents for radiation therapy-enhancement.

    Science.gov (United States)

    Delorme, Rachel; Taupin, Florence; Flaender, Mélanie; Ravanat, Jean-Luc; Champion, Christophe; Agelou, Mathieu; Elleaume, Hélène

    2017-11-01

    Nanoparticles appear as a novel tool to enhance the effectiveness of radiotherapy in cancer treatments. Many parameters influence their efficacy, such as their size, concentration, composition, their cellular localization, as well as the photon source energy. The current Monte Carlo study aims at comparing the dose-enhancement in presence of gadolinium (Gd), either as isolated atoms or atoms clustered in nanoparticles (NPs), by investigating the role played by these physical parameters at the cellular and the nanometer scale. In parallel, in vitro assays were performed in presence of either the gadolinium contrast agent (GdCA) Magnevist(®) or ultrasmall gadolinium NPs (GdNPs, 3 nm) for comparison with the simulations. PENELOPE Monte Carlo Code was used for in silico dose calculations. Monochromatic photon beams were used to calculate dose enhancements in different cell compartments and low-energy secondary electron spectra dependence with energy. Particular attention has been placed on the interplay between the X-ray beam energy, the Gd localization and its distance from cellular targets. Clonogenic assays were used to quantify F98 rat glioma cell survival after irradiation in the presence of GdNPs or GdCA, using monochromatic X-rays with energies in the 30 keV-80 keV range from a synchrotron and 1.25 MeV gamma photons from a cobalt-60 source. The simulations that correspond to the experimental conditions were compared with the experimental results. In silico, a highly heterogeneous and clustered Gd-atom distribution, a massive production of low energy electrons around GdNPs and an optimal X-ray beam energy, above the Gd K-edge, were key factors found to increase microscopic doses, which could potentially induce cell death. The different Gd localizations studied all resulted in a lower dose enhancement for the nucleus component than for cytoplasm or membrane compartments, with a maximum dose-enhancement factor (DEF) found at 65 keV and 58 keV, respectively

  14. Prediction of aortic enhancement on coronary CTA images using a test bolus of diluted contrast material.

    Science.gov (United States)

    Masuda, Takanori; Funama, Yoshinori; Imada, Naoyuki; Sato, Tomoyasu; Yamagami, Takuji; Tatsugami, Fuminari; Awai, Kazuo

    2014-12-01

    The purpose of our study was to compare test bolus techniques using undiluted or diluted contrast material for their ability to predict aortic enhancement on coronary computed tomographic angiography (c-CTA) images. We divided 200 consecutive patients who underwent c-CTA on a 64-MDCT scanner into two groups. In group A (n = 100), we used a test bolus of undiluted contrast material and in group B (n = 100), the contrast material was diluted. The injection volume was body weight × 0.2 (contrast material 100%) in group A and body weight × 0.7 (contrast material 30%, saline 70%) in group B. We then compared the CT number in the ascending aorta on c-CTA images obtained with undiluted and diluted contrast media to the CT number on c-CTA images. The mean CT number in the ascending aorta was significantly higher in group B than group A (217.1 vs. 157.4 HU, P images and on images acquired with the test bolus using undiluted or diluted test bolus (P enhancement before c-CTA scanning. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

  15. Optimization of scantiming in abdominal breathhold contrast-enhanced MRA : an empirical guideline

    NARCIS (Netherlands)

    Boeve, WJ; Sluiter, WJ; Kamman, RL

    The objective of this study to determine a suitable scan timing scheme in contrast enhanced MRA for the depiction of the arterial. the portal and the systemic venous system in the abdomen with maximum signal intensity in healthy subjects and in patients with cirrhosis. The signal intensity in the

  16. Dynamic contrast-enhanced MRI for monitoring response to neoadjuvant chemotherapy in breast cancer

    NARCIS (Netherlands)

    Loo, C.E.

    2016-01-01

    The general aim of this thesis is to investigate the role of dynamic contrast-enhanced MRI in monitoring response of breast cancer during neoadjuvant chemotherapy. The role of MRI with respect to achieving personalized breast cancer treatment by improving response monitoring is examined. Our

  17. Contrast-enhanced duplex scanning of crural arteries by means of continuous infusion of Levovist

    NARCIS (Netherlands)

    Coffi, Stephen B.; Ubbink, Dirk Th; Zwiers, Ineke; van Gurp, Johan A. M.; Hanson, Dianne; Legemate, Dink A.

    2004-01-01

    Objectives: To estimate the dosage needed for continuous infusion and to investigate whether continuous infusion of the ultrasound contrast-enhancing agent Levovist (SH U 508A) can improve duplex scanning of crural arteries in patients with peripheral arterial obstructive disease (PAOD) eligible for

  18. Dual-energy contrast-enhanced digital mammography in routine clinical practice in 2013.

    Science.gov (United States)

    Badr, S; Laurent, N; Régis, C; Boulanger, L; Lemaille, S; Poncelet, E

    2014-03-01

    To date, analysis of the vascularisation of breast lesions mainly relies on MR imaging. However, the accessibility of MRI is sometimes limited and has led to the development of new means of imaging, such as dual-energy contrast-enhanced mammography, which provides data on the vascularisation of the breast along with the usual morphological information. The purpose of this paper is to present this new imaging technique as well as the recent references, illustrated by clinical reports derived from our everyday practice to focus on the advantages and disadvantages of this new breast exploration. Dual-energy contrast-enhanced mammography is a recent, seemingly promising technique, in the management of breast cancer. The main advantages consist of its easy installation, the good tolerance and the comfort in the interpretation of difficult to read mammograms. However, the indications and the role of dual-energy contrast-enhanced mammography still have to be determined within the diagnostic strategy of breast tumours. New studies are expected, especially to compare dual-energy contrast-enhanced mammography with breast MRI. Copyright © 2013 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  19. A novel approach to tracer-kinetic modeling for (macromolecular) dynamic contrast-enhanced MRI

    NARCIS (Netherlands)

    Jacobs, Igor; Strijkers, Gustav J.; Keizer, Henk M.; Janssen, Henk M.; Nicolay, Klaas; Schabel, Matthias C.

    2016-01-01

    To develop a novel tracer-kinetic modeling approach for multi-agent dynamic contrast-enhanced MRI (DCE-MRI) that facilitates separate estimation of parameters characterizing blood flow and microvascular permeability within one individual. Monte Carlo simulations were performed to investigate the

  20. Infrared Contrast Enhancement Through Log-Power Histogram Modification

    NARCIS (Netherlands)

    Toet, A.; Wu, T.

    2015-01-01

    A simple power-logarithm histogram modification operator is proposed to enhance infrared (IR) image contrast. The algorithm combines a logarithm operator that smoothes the input image histogram while retaining the relative ordering of the original bins, with a power operator that restores the

  1. Contrast enhanced digital mammography: Is it useful in detecting lesions in edematous breast?

    Directory of Open Access Journals (Sweden)

    Noha Abd ElShafy ElSaid

    2015-09-01

    Conclusion: Dual-energy contrast-enhanced digital mammography is a useful technique in identification of lesions in mammographically dense edematous breasts and proved to be a useful tool in the follow-up of cases presenting by edema after conservative breast surgery and chemotherapy.

  2. [Value of real-time contrast-enhanced ultrasound in diagnosis of renal solid renal lesions].

    Science.gov (United States)

    Li, Xin; Liang, Ping; Yu, Xiaoling; Yu, Jie; Cheng, Zhigang; Han, Zhiyu; Liu, Fangyi; Mu, Mengjuan

    2014-06-01

    To investigate the value of real-time contrast-enhanced ultrasound (CEUS) in the diagnosis and differential diagnosis of renal solid renal lesions (RSLs). We retrospectively analyzed 140 cases of 152 RSLs with a mean diameter 3.1∓1.9 cm. CEUS was performed and the perfusion characteristics were analyzed using contrast pulse sequences (CPS) technique. CEUS findings were compared with biopsy histopathologic findings. A total of 137 malignant lesions (including 127 renal clear cell carcinomas, 8 renal papillary carcinomas and 2 chromophobe cell carcinomas) and 15 benign lesions (13 angiomyolipomas and 2 renal oncocytomas) were detected. Of the 137 malignant lesions, 98 (71.5%) showed contrast agent fast perfusion and hyper-enhancement or iso-enhancement in cortical phase, 104 (75.9%) showed hypo-enhancement in later corticalmedullary and late phase, and 125 (91.2%) showed rim-like enhancement. Tumors with a diameter ≤2 cm presented with homogeneous enhancement, and those ranging from 2 to 4 cm showed heterogeneous enhancement with a honeycomb feature; tumors greater than 4 cm featured heterogeneous enhancement with large no-enhancement necrotic areas. Of the benign lesions, 13 angiomyolipomas and 2 renal oncocytomas showed slow wash-in and slow wash-out mode. The diagnostic specificity, accuracy and positive predictive value of CEUS for RSLs were 94.9%, 96.1%, and 73.7%, as compared to 72.3%, 71.1%, and 19.1% with conventional US, respectively (Ppredictive value of CEUS were 93.3% and 99.2%, respectively, significantly higher than those of conventional US (60% and 94.3%, P=0.084, and 0.062, respectively). Real-time CEUS can provide valuable information for impro