- Category: ICUS Weekly News Monitors
1. Journal of Ultrasound in Medicine, Sep 1, 2015, In Search of the Optimal Heart Perfusion Ultrasound Imaging Platform Authors: Dmitry Grishenkov, PhD, et al
2. Journal of Ultrasound in Medicine, Sep 1, 2015, Contrast-Enhanced Sonography for Diagnosing Collateral Transformation of the Hepatic Artery After Liver Transplantation
Authors: Su-Qin Lyu, MM, et al
3. Radiology, Sep1, 2015, Science to Practice: Molecularly Targeted US of Inflammation—Important Steps toward Clinical Translation Author: Fabian Kiessling, MD
4. HPC Wire, Aug 20, 2015, NIH Awards $1.26M to Kitware and Collaborators for Cancer Treatment Research
5. RadioGraphics, Accepted: Feb 23, 2015; Role of US Contrast Agents in the Assessment of Indeterminate Solid and Cystic Lesions in Native and Transplant Kidneys Authors: Chris J. Harvey, MRCP, FRCR; et al
Journal of Ultrasound in Medicine
JUM September 1, 2015 vol. 34 no. 9 1599-1605
Sep 1, 2015
In Search of the Optimal Heart Perfusion Ultrasound Imaging Platform
Authors: Dmitry Grishenkov, PhD⇑, Adrian Gonon, MD, PhD and Birgitta Janerot-Sjoberg, MD, PhD
Departments of Clinical Science, Intervention, and Technology (D.G., B.J.-S.) and Medicine (A.G.), Karolinska Institute, Stockholm, Sweden; Department of Medical Engineering, KTH Royal Institute of Technology, School of Technology and Health, Stockholm, Sweden (D.G., B.J.-S.);and Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden (D.G., A.G., B.J.-S).
Objectives—Quantification of myocardial perfusion by contrast echocardiography remains a challenge. Existing imaging phantoms used to evaluate the performance of ultrasound scanners do not comply with perfusion basics in the myocardium, where perfusion and motion are inherently coupled. To contribute toward an improvement, we developed a contrast echocardiographic perfusion imaging platform based on an isolated rat heart coupled to an ultrasound scanner.
Methods—Perfusion was assessed by using 3 different types of contrast agents: dextran-based Promiten (Meda AB, Solna, Sweden), phospholipid-shelled SonoVue (Bracco Diagnostics, Inc, Princeton, NJ), and polymer-shelled MB-pH5-RT, developed in-house. The myocardial video intensity was monitored over time from contrast agent administration to peak, and 2 characteristic constants were calculated by using an exponential fit: A, representing capillary volume; and β, representing inflow velocity.
Results—Acquired experimental evidence demonstrates that the application of all 3 contrast agents allows sonographic estimation of myocardial perfusion in the isolated rat heart. Video intensity maps show that an increase in contrast concentration increases the late-plateau values, A, mimicking increased capillary volume. Estimated values of the flow, proportional to A × β, increase when the pressure of the perfusate column increases from 80 to 110 cm of water. This finding is in agreement with the true values of the coronary flow increase measured by a flowmeter attached to the aortic cannula.
Conclusions—The contrast echocardiographic perfusion imaging platform described holds promise for standardized evaluation and optimization of contrast perfusion ultrasound imaging in which real-time inflow curves at low acoustic power semiquantitatively reflect coronary flow.
Journal of Ultrasound in Medicine
JUM September 1, 2015 vol. 34 no. 9 1591-1598
Sep 1, 2015
Contrast-Enhanced Sonography for Diagnosing Collateral Transformation of the Hepatic Artery After Liver Transplantation
Authors: Su-Qin Lyu, MM, Jie Ren, MD, Rong-Qin Zheng, MD⇑, Xiao-Chun Meng, MD, Ming-ShenHuang, MD and Ping Wang, MD
Departments of Medical Ultrasonics (S.-Q.L., J.R., R.-Q.Z., P.W.) and Radiology (X.-C.M., M.-S.H.), Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Objectives—To determine the contrast-enhanced sonographic features of hepatic artery collateral transformation in patients with hepatic artery complications after liver transplantation.
Methods—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.
Results—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.
Conclusions—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.
Sep 1, 2015
Volume 276: Number 3—September 2015 n radiology.rsna.org
Science to Practice: Molecularly Targeted US of Inflammation—Important Steps toward Clinical Translation
Author: Fabian Kiessling, MD
Institute for Experimental Molecular Imaging
RWTH Aachen University
52074 Aachen, Germany
Dual P- and E-selectin–targeted microbubbles (MBs) have previously been used for ultrasonography (US) of acute inflammatory bowel disease in mice. In the study by Wang and colleagues, such dual-targeted MBs were evaluated in pigs. After induction of ileitis by means of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)/ethanol installation, early inflammation, as well as mild and severe disease stages, could be distinguished. The molecularly targeted US method was characterized by high reproducibility and matched with histologic findings. This work is considered an important intermediate step in translating molecularly targeted US of inflammation from preclinical toward clinical application.
Aug 20, 2015
NIH Awards $1.26M to Kitware and Collaborators for Cancer Treatment Research
In cancer drug research, existing imaging technologies used to assess treatment response are expensive, time consuming, and difficult to operate. To overcome these challenges, the National Institutes of Health (NIH) has funded a $1.26 million small-business research project, led by Kitware, to develop a low-cost and widely applicable system for assessing cancer treatment efficacy.
The research project is centered on a novel approach to cancer detection and diagnosis that is based on using acoustic angiography to measure small changes in the microvessels that feed tumors. Acoustic angiography is a contrast-enhanced ultrasound imaging technique that is being developed by Dr. Paul Dayton at The University of North Carolina at Chapel Hill (UNC), who is a principal investigator on the project. The technique can provide unprecedented clarity in visualizing microvascular abnormalities associated with malignant cancers that resolve when those cancers respond to treatment. Although acoustic angiography is promising, manually measuring the microvessel changes that it reveals can be time consuming and prone to error. For the research project, acoustic angiography is combined with automated vessel modeling and computer-aided diagnosis methods developed at Kitware to provide a low-cost, fast, and accurate cancer treatment monitoring system.
“The characterization of microvascular features for the diagnosis and monitoring of cancer has shown great promise, but the application of this technique has traditionally involved costly imaging equipment and highly constrained conditions,” Dr. Stephen Aylward, a principal investigator on the project and Senior Director of Medical Research at Kitware, said. “Combining computer-aided diagnosis of microvasculature with acoustic angiography creates a powerful and practical diagnostic tool for preclinical and clinical cancer research.”
During Phase I of the project, Kitware and the Dayton Lab at UNC confirmed that the novel ultrasound-based approach can distinguish benign tumors from malignant tumors and track vascular changes throughout disease development. The team also optimized the methods for modeling and analyzing vessels so that they run in minutes, rather than hours, and offer significantly improved accuracy.
For Phase II, the team will partner with SonoVol to integrate the proposed approach into a commercial ultrasound imaging system for preclinical research. The system will provide cancer researchers with an innovative tool for studying animal models of malignancies in nearly any organ in the body. It will enable rapid alignment of images taken over time for observing longitudinal vascular remodeling and present substantial benefits over existing technologies. For example, the system will cost less than half of what traditional systems cost; it will be suitable for users who do not have expertise in imaging physics; and it will be benchtop, user agnostic, and noninvasive.
“An equivalently fast, accurate, noninvasive, low-cost, and quantitative tumor micro-environment imaging instrument does not exist,” Aylward said. “As a result, most researchers have to reserve time and expert support on shared instruments at facilities that charge extremely high fees. The proposed system will provide affordable and easy-to-use technology that could accelerate the pace of cancer research, bringing life-saving therapeutics to the patient’s bedside sooner and with a lower development cost.”
As part of the Phase II effort, Kitware will release algorithms for vessel modeling and analysis as open-source software, building on the Insight Segmentation and Registration Toolkit (ITK) and the 3D Slicer application for medical data visualization. Both ITK and 3D Slicer are freely available. They are developed and supported by Kitware and are used in medical image analysis research and commercial products throughout the world.
In addition to participating in the collaborative research effort, Kitware provides consulting services to groups that seek to build commercial systems using ITK and 3D Slicer, as well as Kitware’s expertise in low-cost ultrasound applications, vessel quantification, and other medical technologies. To learn more about leveraging Kitware’s expertise, please contact Stephen Aylward at kitware(at)kitware.com.
Kitware is an advanced technology, research, and open-source solutions provider for research facilities, government institutions, and corporations worldwide. Founded in 1998, Kitware specializes in research and development in the areas of HPC and visualization, medical imaging, computer vision, data and analytics, and quality software process. Among its services, Kitware offers consulting and support for high-quality software solutions. Kitware is headquartered in Clifton Park, NY, with offices in Carrboro, NC; Santa Fe, NM; and Lyon, France. More information can be found on http://www.kitware.com.
Received: November 25, 2014
Accepted: Feb 23, 2015
Role of US Contrast Agents in the Assessment of Indeterminate Solid and Cystic Lesions in Native and Transplant Kidneys
Authors: Chris J. Harvey, MRCP, FRCR; Ali Alsafi, MBBS, BSc (Hons), FRCR; Siarhei Kuzmich, FRCR; An Ngo, MB, BS, MRCP; Ioanna Papadopoulou, FRCR; Amish Lakhani, MBBS, MA, FRCR
Yaron Berkowitz, MBChir, MA,MRCS, FRCR; Steven Moser, MB, BS, FRCR; Paul S. Sidhu, FRCP, FRCR; David O. Cosgrove, FRCP, FRCR
From the Departments of Imaging, Hammersmith Hospital, Imperial College NHS Trust, Du Cane Road, London W12 0HS, England (C.J.H., A.A., A.N., I.P., A.L., Y.B., S.M., D.O.C.); Department of Imaging, Whipps Cross University Hospital, London, England (S.K.); and Department of Imaging, King’s College Hospital, London, England (P.S.S.).
Ultrasonography (US) is often the initial imaging modality employed in the evaluation of renal diseases. Despite improvements in B-mode and Doppler imaging, US still faces limitations in the assessment of focal renal masses and complex cysts as well as the microcirculation. The applications of contrast-enhanced US (CEUS) in the kidneys have dramatically increased to overcome these shortcomings with guidelines underlining their importance. This article describes microbubble contrast agents and their role in renal imaging. Microbubble contrast agents consist of a low solubility complex gas surrounded by a phospholipid shell. Microbubbles are extremely safe and well-tolerated pure intravascular agents that can be used in renal failure and obstruction, where computed tomographic (CT) and magnetic resonance (MR) imaging contrast agents may have deleterious effects. Their intravascular distribution allows for quantitative perfusion analysis of the microcirculation, diagnosis of vascular problems, and qualitative assessment of tumor vascularity and enhancement patterns. Low acoustic power real-time prolonged imaging can be performed without exposure to ionizing radiation and at lower cost than CT or MR imaging. CEUS can accurately distinguish pseudotumors from true tumors. CEUS has been shown to be more accurate than unenhanced US and rivals contrast material–enhanced CT in the diagnosis of malignancy in complex cystic renal lesions and can upstage the Bosniak category. CEUS can demonstrate specific enhancement patterns allowing the differentiation of benign and malignant solid tumors as well as focal inflammatory lesions. In conclusion, CEUS is useful in the characterization of indeterminate renal masses and cysts. Online supplemental material is available for this article.