The Hong Kong
Radiographers' Association
Login | Join Us | Join As Guest
Knowledge Gateway
G00018 Virtual Grid Adapts X-rays Contrast to Improve Image Quality Sans a Grid
Category : CR/DR
Fujifilm Medical Systems will introduce a new X-ray image processing tool called Virtual Grid at the Radiological Society of North America (RSNA) in Chicago, Ill. The Virtual Grid intelligently adapts contrast to improve image quality for exams that are taken without a grid. The Virtual Grid automatically adapts its processing to replicate grid use to reduce degradation of image quality caused by scatter radiation. This new feature analyzes the image for scatter effect based on exam menu and selected parameters and offers automated, selectable grid ratios to further adapt image quality to site preferences. Physical add-on grids are commonly required for mobile imaging of large anatomy to help focus radiation to reduce scatter and blurring. Virtual grid processing will be a great benefit to technologists for mobile imaging in emergency room (ER), operating room (OR), bedside, wheelchair and other exams where they may not have the optimal grid or any grid on hand. Use of Virtual Grid also eliminates artifacts typical from misalignment of the tube to detector/grid angle. For more information:
G00007 "Back To Basics" campaign launched by Image Gently to reduce radiation dose in paediatric DR exams
Category : CR/DR
Paediatric dose reduction in Digital Radiography can be achieved by encouraging radiographers to : 1. Measure the thickness of a pediatric patient to select the most appropriate imaging technique. 2. Avoid relying on digital image processing to correct for over- or underexposure. 3. Avoid using grids whenever possible, and when imaging a body part less than 10- to 12-cm thick, such as a wrist or a foot. 4. Ensure only the indicated area is exposed to radiation, with proper collimation and shielding, instead of only using electronic cropping after the exposure.
G00003 Image artifacts degrade digital radiography performance
Category : CR/DR
New forms of image artifacts can compromise the performance of digital radiography (DR) equipment, say researchers from the Mayo Clinic in Rochester, MN. The group described its experience with DR artifacts and how to correct for them. Artifacts featured in the Mayo paper were produced by flat-panel DR detectors with an amorphous silicon thin-film transistor array, coupled to a phosphor layer of either cesium iodide or gadolinium oxysulfide. Specific equipment models in the study included DRX-1 from Carestream Health, Definium 8000 from GE Healthcare, DigitalDiagnost from Philips Healthcare, and Axiom Aristos MX from Siemens Healthcare.
G00017 Exploring X-ray Phase Tomography With Synchrotron Radiation
Category : CT
X-ray phase tomography is an imaging technique that uses penetrating X-rays to create volumetric views through "slices" or sections of soft biological tissues, such as tumors, and it offers strongly enhanced contrast compared to conventional CT scans. Yet scientists still do not know which X-ray phase tomography methods are best suited to yield optimized results for a wide variety of conditions. To answer this question, a large group of researchers in Europe compared three different X-ray phase tomography methods at the European Synchrotron Radiation Facility's (ESRF) beamline ID19 in France — X-ray grating interferometry, propagation-based phase tomography with single-distance phase reconstruction and holotomography. Led by Irene Zanette, a scientist affiliated with both ESRF and the Technische Universität München (TUM) in Germany, the researchers examined cancerous tissue from a mouse model and an entire rat's heart, which they report in the Journal of Applied Physics, from AIP Publishing. Along with colleagues Bert Müller, group leader of the Biomaterials Science Center in Switzerland, and Timm Weitkamp, a scientist at the Synchrotron SOLEIL in France, the team explored which method performs best in terms of spatial resolution and visualization/quantification of relevant features in the samples. They also investigated other related factors such as the simplicity of the setup, and the data acquisition and analysis involved in each method. The researchers chose to exploit synchrotron radiation, which produces significantly higher-quality X-rays than conventional X-ray generators such as those found in hospitals. "Think of synchrotron radiation as being analogous to the sort of monochromatic, collimated and intense light produced by lasers, while conventional X-ray generators in hospitals are more analogous to light bulbs we use within our homes," explained Zanette. Zanette explained that while their study was performed using synchrotron radiation, the same techniques are amenable to both polychromatic and divergent beams and can also be implemented at conventional X-ray sources. The researchers used an advanced X-ray technique known as "phase-contrast imaging." This type of imaging works by making the X-ray beam interfere while it propagates from sample to detector, according to Zanette. "This interference is fundamental because it encodes precious information on the phase of the X-ray waves." By comparison, conventional X-ray imaging — of the sort performed at hospitals and airports — does not use phase information. Rather, it relies only on the attenuation of the amplitude (reduction in intensity) of the X-ray waves by the object under study to generate image contrast. "More detailed information is contained in the phase than the amplitude, so it enables us to obtain images with much greater contrast and clearly differentiates cancerous tissue from healthy tissue," Zanette said. The researchers were able to show that for each specimen, the spatial resolution derived from the characteristic morphological features is about twice as good for holotomography and single-distance phase reconstruction compared to X-ray grating interferometry. They also found that X-ray grating interferometry data generally provide much better contrast-to-noise ratios for anatomical features, excel in fidelity of the density measurements, and are more robust against low-frequency artifacts than holotomography. The researchers regard all three of the phase tomography methods as being complementary. "The application determines which spatial and density resolutions are desired for the imaging task and dose requirements, so it really comes down to a choice between the complexity of the experimental setup and the data processing," noted Müller. "It's important to choose the ideal technique for your specific purposes." Since synchrotron radiation is of higher quality than the radiation at conventional sources, measurements at synchrotrons represent benchmarking experiments when translating these tomography techniques to clinical practice — especially X-ray grating interferometry, which is attracting attention for use in hospitals. The article, "Experimental comparison of grating- and propagation-based x-ray phase tomography of soft tissue," is authored by Sabrina Lang, Irene Zanette, Marco Dominietto, Max Langer, Alexander Rack, Georg Schulz, Geraldine Le Duc, Christian David, Jürgen Mohr, Franz Pfeiffer, Bert Müller and Timm Weitkamp. The authors of the paper are affiliated with Technische Universität München in Germany, Biomaterials Science Center in Switzerland, and Synchrotron SOLEIL in France. For more information:
G00004 Diagnostic Reference Levels (DRLs) in CT
Category : CT
Diagnostic reference levels (DRLs) are a practical tool to promote the assessment of existing protocols and appropriate development of new and improved protocols at each CT centre by facilitating the comparison of doses from present practice. DRLs were first successfully implemented in relation to conventional X rays in the 1980s and subsequently developed for application to CT in the 1990s. Read more information
G00001 Future development of contrast media
Category : CT
CT nanoparticle-based contrast agents are all investigational; and at this point all preclinical but they're out there. In a few years, the tiny contrast agent delivery vehicles, which work well in animals, could greatly affect the diagnosis and treatment of disease in humans. That's according to David Cormode, PhD, assistant professor of radiology at the University of Pennsylvania.
G00002 Do you know what is meant by “apple core sign”?
Category : Fluoro
Answer: An apple core sign is usually found in the Barium enema studies to describe a constriction of the lumen of the colon by a stenosing annular colorectal carcinoma.
G00010 Study indicated adding tomosynthesis to full-field digital mammography improved cancer detection rat
Category : MG
Breasts are considered dense if they have a lot of fibrous or glandular tissue but not much fatty tissue. Research has shown that dense breasts are more likely to develop cancer, a problem compounded by the fact that cancer in dense breasts can be difficult to detect on mammograms. Other imaging modalities like ultrasound and magnetic resonance imaging (MRI) are often used to help find cancers that can't be seen on mammograms, but both modalities have higher rates of false-positive findings. This higher false-positive rate often results in more tests and unnecessary biopsies, making MRI and ultrasound expensive to implement in high-volume screening programs, according to study lead author Per Skaane, M.D., Ph.D., from the department of radiology at Oslo University Hospital in Oslo, Norway. Skaane and colleagues have been studying tomosynthesis as a promising breast cancer screening option that addresses some of the limitations of mammography by providing 3-D views of the breast. "Tomosynthesis could be regarded as an improvement of mammography and would be much easier than MRI or ultrasound to implement in organized screening programs," Skaane said. "So the intention of our study was to see if tomosynthesis really would significantly increase the cancer detection rate in a population-based mammography screening program." The researchers compared cancer detection using full-field digital mammography (FFDM) versus FFDM plus digital breast tomosynthesis in 25,547 women between the ages of 50 and 69. Breast density was classified based on the American College of Radiology's Breast Imaging-Reporting and Data System (BI-RADS). The BI-RADS breast density scale runs from 1 to 4, with 1 being the least dense and 4 being the most dense. There were 257 malignancies detected on FFDM and a combination of FFDM and tomosynthesis in the study group, including 105 in the density 2 group and 110 in density 3. Of the 257 cancers, 211 — or 82 percent — were detected with FFDM plus tomosynthesis, a significant improvement over the 163 — or 63 percent — detected with FFDM alone. FFDM plus tomosynthesis pinpointed 80 percent of the 132 cancer cases in women with dense breasts, compared to only 59 percent for FFDM alone. "Our findings are extremely promising, showing an overall relative increase in the cancer detection rate of about 30 percent," Skaane said. "Stratifying the results on invasive cancers only, the relative increase in cancer detection was about 40 percent." Tomosynthesis not only improved the cancer detection rate in women with dense breasts, it also helped increase detection for women in the "fatty breast" BI-RADS categories. The addition of tomosynthesis to FFDM improved the cancer detection rate from 68 percent to 84 percent in women with BI-RADS density 1 or 2 breasts. For more information:
G00014 PET/MR Superior for Verifying Coronary Arterial Disease??
Category : MR
Ischemic heart disease, a narrowing of the arteries supplying blood to the heart, is a leading cause of death throughout the world. A hybrid molecular imaging technique called positron emission tomography and magnetic resonance imaging (PET/MR), which tells doctors vital information about cardiac and arterial function, has been found to be an effective molecular imaging tool for detecting coronary artery disease (CAD), say researchers at the Society of Nuclear Medicine and Molecular Imaging’s 2014 Annual Meeting (SNMMI). Often patients suspected of having CAD undergo a stress test called myocardial perfusion imaging (MPI) to smoke out areas of arterial ischemia and risk of myocardial infarction, or heart attack. Many undergo a molecular imaging scan called single photon emission computed tomography (SPECT), but in recent years PET/MR has emerged as a potential alternative due to its superiority for imaging the structures of soft tissues and the physiological function of the heart. This clinical study showed that PET/MR is consistently accurate using coronary angiography as the reference standard for detecting CAD. “By combining two advanced imaging modalities, PET and MR, cardiac PET/MR imaging allows a union of anatomic information with MR and functional information with PET for a comprehensive view of the of the heart,” said principal author Jeffrey M.C. Lau, M.D., Ph.D., from Washington University in St. Louis, Mo. “This allows us to predict or rule out coronary artery disease with more certainty, and in some instances, it allows us to detect disease processes such as areas of hibernating heart muscle that would not have been detected using conventional stress testing methods like SPECT.” In addition, cardiac perfusion PET/MR can be performed in a shorter timeframe than SPECT and is associated with a lower dose of radiation per procedure, and MR can be used to produce an almost of disease in the arteries of the heart when compared to industry standard cinematic, multiple-frame sequence of the motion in specific regions of the heart muscle, most notably the left ventricle, which pumps oxygenated blood back into the body through the aorta. PET also provides quantitative data about blood flow in addition to the visual interpretation of disease. The study involved 10 patients with reversible ischemia as indicated by SPECT-MPI. Scientists administered a radionuclide PET imaging agent called N-13 ammonia plus an MR contrast agent called gadolinium and the pharmaceutical Regadenoson, which imitates the stress of exercise. The researchers optimized the cardiac PET/MR imaging protocol in order to register areas of reduced perfusion of blood using MR with PET data about myocardial blood flow. The results showed that PET/MR imaging was very accurate in diagnostic coronary artery diseases. In this small sample, PET/MR had 100 percent sensitivity, 80 percent specificity and 100 percent negative predictive value. Those numbers compare favorably to SPECT in this study group. This study was conducted in conjunction with Siemens Medical Solutions and funded in part by Astellas Pharma Inc. For more information:
G00005 ESUR updates guidelines to prevent NSF
Category : MR
Contrast Media Safety Committee of the European Society of Urogenital Radiology (ESUR) issued updated guidelines regarding Nephrogenic Systemic Fibrosis (NSF). Patients with Glomerular Filtration Rate (GFR) below 30mL/min/1.73m2 bear an increased risk of developing NSF.
G00016 New Fluoroscopy Initiative
Category : Others
Image now offers online educational materials for fluoroscopy, computed tomography (CT) and nuclear medicine exams. Fluoroscopy is the latest addition to Image Wisely, which helps radiology providers optimize radiation dose and provide safe, effective imaging care. “Fluoroscopy can deliver one of the higher radiation doses in medical imaging. This new initiative will help radiology providers deliver quality patient care and optimize radiation dose and image quality during fluoroscopic procedures,” said Richard Morin, Ph.D., co-chair and American College of Radiology (ACR) representative to Image Wisely. The materials cover a broad array of topics including: principles of radiation safety for patients and the teams performing fluoroscopy procedures; dose monitoring; teamwork; organizational culture; checklists and other tools from the process improvement perspective. Also included are protocols and techniques on principles for diagnostic fluoroscopic procedures, interventional procedures and cardiac procedures. “Careful planning and execution of fluoroscopically-guided interventional procedures can reduce procedure risk as well as radiation exposure to the patient and hospital staff,” said William Mayo-Smith, M.D., co-chair and Radiological Society of North America (RSNA) representative to Image Wisely. While fluoroscopy is the third largest source of medical radiation exposure behind CT and nuclear medicine, it provides tremendous diagnostic and treatment value. Fluoroscopy is used in many types of examinations and procedures, including barium enemas, cardiac catheterization, arthrography, angiography and biopsies. “Our goal is to ensure that every facility uses appropriate dose reduction techniques when performing fluoroscopic procedures,” said Donald Peck, Ph.D., American Association of Physicists in Medicine (AAPM) representative to Image Wisely. “The new Image Wisely webpage is a one-stop location to find advice and links to credible resources to help facilities reduce the incidence of adverse reactions to the patient due to excess radiation and improper technique.” “Radiation safety during fluoroscopic procedures depends on an extensive network of people working together as a team,” said Greg Morrison, MA, RT (R), American Society of Radiologic Technologist (ASRT) representative to Image Wisely. “High-performing teams greatly exceed the capabilities of individuals, no matter their skill, intelligence or dedication.” For more information:
G00015 Top 10 Health Technology Hazards for 2015
Category : Others
To help hospitals reduce technology-related risks, ECRI Institute publishes an annual list of Top 10 Health Technology Hazards. The 2015 hazards list highlights 10 safety topics and details a variety of technology hazards that put patients at risk. Each hazard includes an overview of the issue and recommended action steps to aid healthcare facilities in their efforts to maintain a safe environment for patients and healthcare workers. Topics include: 1. Alarm hazards: Inadequate alarm configuration policies and practices 2. Data integrity: Incorrect or missing data in electronic health records and other health IT systems 3. Mix-up of IV lines leading to misadministration of drugs and solutions 4. Inadequate reprocessing of endoscopes and surgical instruments 5. Ventilator disconnections not caught because of mis-set or missed alarms 6. Patient-handling device use errors and device failures 7. “Dose creep”: Unnoticed variations in diagnostic radiation exposures 8. Robotic surgery: Complications due to insufficient training 9. Cybersecurity: Insufficient protections for medical devices and systems 10. Overwhelmed recall and safety alert management programs This year, the report draws particular attention to alarm configuration practices. ECRI Institute is aware of several deaths and other cases of severe patient harm that may have been prevented with more effective alarm policies and practices. Recall management points to overwhelmed recall and safety-alert programs as a potential for serious consequences for healthcare facilities and patients. ECRI experts are concerned that existing hospital recall tracking programs are not keeping pace with the growing number of medical device recalls issued each year. The U.S. Food and Drug Administration (FDA) reports that the annual number of medical device recalls nearly doubled between 2003 and 2012, from 604 recalls to 1,190 annually. For each topic, ECRI Institute describes the hazard, presents recommendations for minimizing the risks, and lists helpful resources that readers can access to learn more about the topic. To develop the annual list, ECRI Institute’s multidisciplinary staff of engineers, scientists, nurses, physicians and patient safety analysts draw on the resources of the Institute’s 45-year history, as well as expertise and insight gained through testing and analyzing healthcare technologies. This includes examining health technology-related problem reports from hospitals and health systems worldwide, and reports received through ECRI Institute Patient Safety Organization. For more information:
G00011 Clinical manifestations and diagnosis of Ebola virus disease
Category : Others
INTRODUCTION — The family Filoviridae consists of two genera, the Ebola and Marburg viruses, which are among the most virulent pathogens of humans [1]. The Zaire species of Ebola virus, discovered in an outbreak in Zaire (the present Democratic Republic of the Congo) in 1976, is the causative agent of the 2014 epidemic in West Africa, where the case fatality rate is estimated to be as high as70 percent [2]; rates in earlier outbreaks reached 80 to 90 percent [3]. Epidemics of Ebola virus disease are generally thought to begin when an individual becomes infected through contact with the body fluids of an infected animal. Once the individual becomes ill or dies, the virus then spreads to others who come into direct contact with their blood, skin, or other body fluids. On rare occasions, Ebola virus disease has resulted from accidental laboratory infections, and there is concern that the virus might be used as an agent of bioterrorism. The clinical manifestations and diagnosis of Ebola virus disease will be reviewed here. The epidemiology, pathogenesis, treatment, and prevention of this disease are discussed elsewhere. (See "Epidemiology and pathogenesis of Ebola virus disease" and "Treatment and prevention of Ebola virus disease".) For more details, please refer to this link:
G00009 Agfa e-Literature
Category : Others
Agfa Healthcare Publications include THERE magazine which is published 4 times per annual - Agfa e-Literature
G00008 Conducting clinical research and principles of evidence-based practice
Category : Others
Check out this compilation from journal of Medical Imaging and Radiation Sciences on how to conduct clinical research and principles of evidence-based practice
G00019 Post-Operative RT Improves Survival for Patients with Resected Non-small Cell Lung Can
Category : RT
Patients who received post-operative radiation therapy (PORT) lived an average of four months longer when compared to patients who had the same disease site, tumor histology and treatment criteria but did not receive PORT, according to research presented at the 2014 Chicago Multidisciplinary Symposium in Thoracic Oncology. The symposium is sponsored by the American Society of Clinical Oncology (ASCO), the American Society for Radiation Oncology (ASTRO), the International Association for the Study of Lung Cancer (IASLC) and The University of Chicago Medicine. This study reviewed the records of non-small cell lung cancer patients treated from 2004 to 2006 from the National Cancer Data Base (NCDB), a joint endeavor of the Commission on Cancer of the American College of Surgeons and the American Cancer Society. The study authors acquired the data for patients who had surgically resected non-small lung cancer with pathologically involved N2 (pN2) lymph nodes (tumors had spread to the lymph nodes in the center of the chest) and who received chemotherapy. The database was further queried to exclude patients with positive margins, incomplete survival data, those who did not receive adjuvant chemotherapy, histology other than NSCLC, and patients treated with Cobalt-60, non-beam radiotherapy or neoadjuvant radiotherapy. Two thousand one hundred and fifteen patients (2,115) met all of the study criteria. Forty-three percent of patients (918) received PORT; 56.6 percent of the patients (1,197) were not treated with PORT. Factors associated with overall survival (OS) were assessed through a multivariable Cox proportional hazards model. Inverse probability of treatment weighting (IPTW) using the propensity score was also implemented to reduce biased treatment selection. Using an adjusted Kaplan-Meier estimator and the weighted log-rank test based on the IPTW, patients treated with PORT had an improved overall survival (median survival time) of 42 months compared to 38 months for the patients not treated with PORT (p=0.048). Multivariable analysis revealed that female gender, adenocarcinoma histology, higher income, urban/rural setting vs. metropolitan setting, lower T state, 1-2 involved lymph nodes vs. =3 examined and involved lymph nodes, and younger age correlated to better OS (p<0.05). No direct relation was found between the effects of PORT and the number of involved lymph nodes. “These results reinforce the value of PORT for non-small cell lung cancer patients with involved mediastinal lymph nodes. Our data indicates that with modern radiotherapy equipment and treatment techniques, PORT can improve survival for these patients,” said John L. Mikell, MD, lead study author and chief resident in the Department of Radiation Oncology at Emory University Winship Cancer Institute in Atlanta. “The data in this study, the largest, most recent cohort of patients with involved mediastinal nodes treated with chemotherapy reinforce that PORT should be considered in addition to chemotherapy following resection of non-small cell lung cancer.” For more information:
G00013 Brainlab Celebrates 625th installation of ExacTrac X-Ray Monitoring System
Category : RT
Brainlab announced the installation of the 625th ExacTrac X-Ray. ExacTrac X-Ray provides sub-millimetric precison and a unique approach for solving the complexities associated with intra-fractional patient motion by internally verifying the patient’s position with stereoscopic X-ray at the time of treatment, even at non-coplanar couch positions. ExacTrac X-Ray monitoring is especially valuable for cranial stereotactic radiosurgery (SRS) and spinal stereotactic body radiation therapy (SBRT) treatments. Clinicians are able to use ExacTrac X-Ray technology for patient setup as well as patient monitoring throughout treatment delivery. It allows the continuous verification of the patient’s position—at any point during treatment—based on internal anatomy and regardless of technique or couch position. ExacTrac can be installed on any linear accelerator system complementing the LINAC with the unique ability to detect intra-fractional motion based on the patient’s internal anatomy. The 625th ExacTrac X-Ray was installed in September 2014. For more information:
G00012 Hong Kong Medical Center Unites Radiotherapy Systems with Elekta OIS
Category : RT
New system integrates separate systems for seamless radiotherapy planning and treatment In their efforts to better integrate the radiation therapy treatment and planning systems of multiple providers, clinicians at Hong Kong Sanatorium & Hospital replaced their Varian ARIA oncology information system (OIS) with Elekta's Mosaiq OIS. Integrated with the hospital's Varian and Accuray linear accelerators and treatment planning systems, Mosaiq went live at the medical center in August. "Radiotherapy planning and treatment need to be seamless processes, but that can be difficult to achieve when operating radiation treatment systems and planning systems from multiple vendors," says George Chiu, head, department of radiotherapy at Hong Kong Sanatorium & Hospital. "In 2011, when we began to explore how we could integrate the different systems under one database, we discovered that Elekta had a solution for that in Mosaiq." In its evaluation, Chiu led a team that visited the Mosaiq installation at the National Cancer Centre Singapore. After that, a project team was assembled to gather more information at additional sites in Taiwan, Singapore, Toronto (Canada) and New York City. "In April 2014, we set up a Mosaiq test environment in our hospital to evaluate hardware and software connectivity with our diverse array of systems,” Chiu says. “Everything went smoothly, so we were able to go live with Mosaiq in August." He adds that the open connectivity to all systems means that patient information is no longer stored in separate systems. Clinicians at Hong Kong Sanatorium & Hospital can now track patient treatment, clinical outcomes and quality measurements with more ease and efficiency. For more information:
G00020 Communication Radiation Risks in Pediatric Imaging by WHO
Category : Radiation Protection
We want to inform that WHO has just published the document “Communication radiation risks in paediatric imaging: Information to support health care discussions about benefit and risk” This document is intended to be a tool for health care providers to communicate about risks associated with paediatric imaging procedures. The document is freely available at this link , where you will find the pdf full report version plus three separate pdf files for end-users to be able to download separately the chapters 1, 2 & 3.
G00006 FDA approved first ultrasound imaging system for dense breast tissue, to help detect breast cancer
Category : US
Mammograms of dense breasts can be difficult to interpret. Fibroglandular breast tissue and tumors both appear as solid white areas on mammograms. As a result, dense breast tissue may obscure smaller tumors, potentially delaying detection of breast cancer. Ultrasound imaging has been shown to be capable of detecting small masses in dense breasts. The results of the approval study showed a statistically significant increase in breast cancer detection when Automated Breast Ultrasouond System (ABUS) images were reviewed in conjunction with mammograms, as compared to mammograms alone. More Information from FDA link
© Copyright and Privacy HKRA.