Study: Comparison of Computer-Aided Diagnosis & Quantitative Image Analysis

Differences have implications for assessment, quality assurance, and training

Zhimin Huo, PhD, Carestream Health

Healthcare imaging technologies and options are continually evolving, and their applications in radiology can be puzzling.  One area of confusion is the respective roles of Quantitative Image Analysis (QIA) and Computer-Aided Diagnosis (CAD). Recently we collaborated with several colleagues to compare and contrast the two imaging technologies and advance the work that has been accomplished by the Computer Aided Detection in Diagnostic Imaging Subcommittee (CADSC) of the American Association of Physicists in Medicine (AAPM).

CAD systems, which have been around for about 15 years, incorporate pattern recognition and data analysis capabilities. Computer-aided detection (CADe) systems are intended to mark regions of an image that might reveal specific abnormalities and alert the clinician to these regions during image interpretation. Computer-aided diagnosis (CADx) systems provide to the clinician an assessment of disease, disease type, severity, stage and progression.

QIA, on the other hand, is fairly new. Using computerized tools, it extracts quantitative imaging biomarkers from medical images. A quantitative imaging biomarker is an objectively measured characteristic derived from an in vivo image as an indicator of normal biological processes, pathogenic processes or a response to a therapeutic intervention. Quantitative imaging includes the development, standardization and optimization of anatomical, functional and molecular imaging acquisition protocols, data analyses, display methods and reporting structures.

Similarities and differences in QIA and CAD

The two technologies have some similarities. They both provide advanced image analysis techniques for clinicians. Both commonly use computer methods to extract features. And both emphasize appropriate image acquisition protocols, display methods, training and reporting. However, there are important differences that must be considered.

CAD essentially relies on the ability to make reproducible, quantitative measurements from medical images and combine them into a score or a marker to help clinicians provide a diagnosis.  The emphasis is on how the CAD outputs aid the clinicians in decision-making, diagnosis, treatment planning, treatment response monitoring or outcome prediction.

In QIA the emphasis is on the extraction of biomarkers and on establishing a specific imaging biomarker’s association with a disease condition. QIA can go beyond the anatomical view and into the molecular level. Examples of applications of the two technologies can be seen in the presentation delivered at RSNA.

Through our research, we determined that the differences and similarities between CAD and QIA have considerable implications for assessment, quality assurance and training. These consequences are also documented in the presentation.

CAD and QIA share many common components and both leverage a richness in medical images that has yet to be fully tapped. There is a natural synergy between the two and we expect that methodologies developed in one field are likely to be applicable in the other. Also, both techniques can benefit from standardized assessment, QA and user training procedures. We hope this study increases the coalescence of new ideas and standardized approaches in these closely related fields. #RSNA #imaging #radiology

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Zhimin Huo, Carestream

Zhimin Huo, PhD, is a researcher in Carestream Health’s Research & Innovation Laboratories




The following people also contributed to the study: Berkman Sahiner, PhD and Nicholas Petrick, PhD, US Food and Drug Administration; Samuel G. Armato III, PhD, University of Chicago; Heang-Ping Chan, PhD, University of Michigan; Ronald M. Summers, National Institutes of Health, Clinical Center

Video: The Future of Medicine in Nigeria Depends on Radiology

We spoke with Professor Gbolahan Awosanya, Professor of Radiology, Provost Lagos State University College of Medicine, Nigeria, at RSNA 2015 about the future of medicine in his country.

Dr. Awosanya said that radiology will play a vital role in providing effective healthcare to citizens, but that there are several issues the country must overcome. The biggest one being that there must enough power provided to hospitals so that the equipment and technologies can stay online.

Video: Demonstration of the Touch Prime Ultrasound System

RSNA 2015 proved to be a busy year for the CARESTREAM Touch Prime Ultrasound System. We showcased the Touch Prime XE on the show floor, and had the area packed for a vast majority of the week, as attendees were interested in seeing one of the newest modalities we have to offer.

In the video below, Emilyann Fogarty, MS, RDMS, RVT, Worldwide Ultrasound Applications Engineer, Carestream, gives a demo of the CARESTREAM Touch Prime Ultrasound in the Carestream booth at RSNA 2015.

Video: Demo of the OnSight 3D Extremity System from Carestream

David Chan, Global Product Line Manager, Carestream, gives a demo of the, OnSite 3D Extremity CBCT Sytem from Carestream at RSNA 2015.

The OnSight System is designed to provide pristine 3D images at the point of care—with an easy-open bore and patient access to allow weight-bearing studies not possible with traditional CT. Plus, site and install requirements are low to enable a fast, affordable, convenient imaging process for timely diagnosis and commencement of treatment.

Carestream OnSight 3D Extremity System received FDA 510(k) clearance in September 2016.

Video: Fluoroscopy & Ultrasound Technologies Prove Beneficial in Nigeria

A. Musa Tabari, MBBS, FMCR, FICS, Consultant Diagnostic and Interventional Radiologist, Aminu Kano Teaching Hospital, Nigeria, and Voke Oshevire, Executive Director, INC International Limited, Nigeria, discuss imaging trends and healthcare needs in their country.

Additionally, the two discuss how fluoroscopy and ultrasound provide beneficial healthcare imaging needs in Nigeria.

RSNA 2015: Important Presentations and Studies from Day 5

RSNA 2015In today’s RSNA summary, we look at presentations focused on MRI’s effectiveness in detecting adverse reactions, over use of peripheral arterial disease, using Ferumoxytol in MR imaging of children, mammography priors’ effect on recall rates, and the link between heart and brain disease.

MRI Effective in Detecting Adverse Reactions Around Arthroplasties – RSNA Bulletin

According to presenter Hollis G. Potter, M.D., MRI is the most accurate means by which to detect adverse local tissue reaction (ALTR), tissue damage and bone loss around arthroplasties. ALTRs occur with all fixed- or mobile-bearing constructs in symptomatic and asymptomatic patients. Arthroplasties generate a small amount of metallic debris, which in most cases does not affect the patient. But in a small percentage of people, the immune response generated by the host reacts to the particles and creates areas of tissue necrosis.

Overuse of Peripheral Arterial Disease (PAD) Testing Likely – RSNA Daily Bulletin

According to a study presented by David C. Levin, M.D., professor and chairman emeritus of the Department of Radiology at Jefferson Medical College and Thomas Jefferson University Hospital in Philadelphia, tests for peripheral arterial disease (PAD)—including the use of duplex ultrasound of lower extremities—are probably being overused. The study found that while the use of vascular ultrasound, as well as noninvasive physiologic testing (NPT), for PAD has flattened or even decreased since 2010, as of 2013 it was significantly higher than it was in 2001.

Contrast Agent Ferumoxytol Safe for MR Imaging in Children – RSNA Bulletin

In the largest study of its kind, Anne Muehe, M.D., a postdoctoral fellow in the laboratory of Heike E. Daldrup-Link, M.D., associate professor of radiology at Stanford Medicine in Stanford, CA, and her colleagues have found that ferumoxytol is safe to use as an MR contrast agent in children. The findings are critical for the development of new ferumoxytol-based MR imaging techniques with better image quality and less toxicity.

The More Mammo Priors, the Lower the Recall Rate – AuntMinnie

Comparing screening mammography exams with two or more prior exams reduces by 14% the odds that a woman will be recalled, versus comparing the current exam to a single prior study, according to a study presented by lead author Dr. Jessica Hayward of the University of California, San Francisco (UCSF). Hayward and colleagues conducted a retrospective search of UCSF’s mammography database for screening mammograms performed between June 2010 and March 2015, which yielded a dataset of more than 46,300 screening mammograms in about 22,700 women. The group gathered information on the women’s age, dates of the mammograms identified as comparisons in the clinical report, and recall recommendations.

Imaging Finds Link Between Brain, Heart Disease – Diagnostic Imaging

Subclinical cardiac dysfunction is associated with global and microstructural imaging markers of subclinical brain disease, according to a study presented researchers from the Netherlands. The study performed a prospective population-based study to investigate the cardiac/brain connection. The study included 2,432 participants with a mean age of 56.6; 57.4% were women. Participants with overt heart disease, dementia, and brain infarcts were excluded from the analysis.

RSNA 2015: Important Presentations and Studies from Day 4

RSNA 2015Today’s summary of studies and presentations from RSNA 2015 highlight breast density notification laws, head CT and MRI, MRI technique for osteoarthritis in college football players, organ dose management, and how CT and 3D printing helping in a surgery to separate conjoined girls.

Breast Density Notification Laws Don’t Affect Reporting Over Long-Term – RSNA Daily Bulletin

According to research presented by Manisha Bahl, M.D., M.P.H, a breast imaging fellow at Duke University Medical Center, breast density notification laws have had an immediate but not long-term impact on the reporting of dense breasts on mammography. Dr. Bahl said two possible explanations could account for the study results. Radiologists may have wished to simply avoid the new requirements for reporting, or they downgraded assessments out of fear that facilities would be overwhelmed by an increase in women seeking supplemental screening.

Studies Investigate Significance of Follow-up Head CT, MRI – RSNA Daily Bulletin

A research team at University of California, San Francisco (UCSF) Medical Center sought to evaluate the common practice of ordering CTs at six-hour intervals for mild traumatic brain injury patients with small, deep brain hemorrhages that can’t be decompressed surgically. Only three out of 90 patients studied had any increase in bleeding evident on follow-up CT, and all three had impaired clotting ability, due to either medications or underlying blood conditions. For the other patients, the hemorrhages either were stable or decreased in size on a follow-up scan.

MRI Technique Shows Link to Osteoarthritis in College Football Players – RSNA Daily Bulletin

Wenbo Wei, Ph.D., of Ohio State University presented on how using delayed Gadolinium-enhanced MRI of Cartilage (dGEMRIC) on knee cartilage shows that playing collegiate football for a longer period of time may lead to microstructural damage that is an indicator of osteoarthritis (OA). The findings of the study demonstrate that dGEMRIC is capable of assessing glycosaminoglycan (GAG) loss within each individual articular cartilage region as well as the gradual changes related to the cumulative years of playing collegiate football, said presenter Wenbo Wei, Ph.D., of Ohio State University.

CT, 3D Printing Help Team Separate Conjoined Girls – AuntMinnie

In a 26-hour operation, a multidisciplinary team used CT scans and a 3D-printed model of the organs of conjoined twins to help perform a successful separation. The presentation was given by Dr. Rajesh Krishnamurthy, chief of radiology research and cardiac imaging at Texas Children’s Hospital. The children, Knatalye and Adeline Mata of Lubbock, TX, were born on April 11, 2014. The surgery was attempted 10 months later. To prepare for the separation surgery, Krishnamurthy and colleagues performed volumetric CT imaging with a 320-detector-row scanner, administering intravenous contrast separately to each twin to enhance views of vital structures and plan how to separate the girls.

NCI Software Automates Organ Dose Measurement – AuntMinnie

Researchers from the National Cancer Institute (NCI) are finalizing a longstanding project to build a user-friendly software program that converts CT dose index volume (CTDIvol) scanner readouts into accurate organ dose estimates. The just-published National Cancer Institute CT (NCICT) project shows the calculation for converting normalized CTDIvol to organ doses for six patient ages and both genders recently approved by the International Commission on Radiation Protection (ICRP), with software to be released early next year.



RSNA 2015: Important Presentations and Studies from Day 3

RSNA 2015We continue to chug along at RSNA 2015, and with us was another day full of worthwhile presentations and studies that continue to move medical imaging forward.

Imaging Innovations are Paving Way Toward Healthcare Reform – RSNA Daily Bulletin

James H. Thrall, M.D. explained how medical imaging innovations are paving a substantial part of the pathway toward achieving healthcare reform. Dr. Thrall covered four trends throughout his talk: relentless further development of existing methods, which are transforming the practice of radiology and medicine; further development of special purpose devices, such as a portable MR imaging device that is currently under development; the development of more complex devices for multi-purpose use, such as hybrid imaging devices; and, the development of more complex devices for multi-purpose use, such as hybrid imaging devices.

Explaining, Discussing Medical Imaging is Key to Patient Understanding – RSNA Daily Bulletin

Leila Mostafavi, M.D., of the University of California, Los Angeles, presented on how given the overall lack of awareness many people have about the risks versus benefits of imaging exams, physicians should make deliberate efforts to hold discussions with their patients about their viewpoints of imaging procedures. In her study, Dr. Mostafavi explained that less than half the patients knew that MR does not involve ionizing radiation, and CT patients were more likely to know that CT utilized radiation (85 percent) as compared to those receiving other imaging procedures (43 percent). Most patients (84 percent) correctly identified X-ray imaging as a technique that required radiation. Dr. Mostafavi explained that to improve patient education, doctors should start by making time to initiate discussions with patients about their perceptions of medical imaging.

Imaging Takes on Predictive Role in Gynecological Cancer – RSNA Daily Bulletin

Susanna Lee, M.D., Ph.D., chief of Women’s Imaging at Massachusetts General Hospital presented about how when it comes to gynecological cancers, imaging is transitioning from a position in which it is descriptive and morphologic, to one in which it is predictive and molecular. In another session, Jung Jae Park, M.D., Samsung Medical Center, Sungkyunkwan University School of Medicine in Seoul, Republic of Korea, described a study in which he and his colleagues compared the prognostic value of diffusion weighted MRI (DWI) and PET/CT during concurrent chemotherapy (CCRT) of cervical cancer for predicting disease progression.

Breast Density Alone Not a Cancer Risk Factor – AuntMinnie

High breast tissue density alone is not a strong independent risk factor for cancer, according to a study presented by by Dr. Natasa Katavic from Health Center Osijek in Osijek, Croatia. The study, led by Dr. Natasa Katavic from Health Center Osijek in Osijek, Croatia, included nearly 53,000 mammography exams that had been performed at the center in women ages 50 to 69 over five years. Croatian women are invited for mammography screening every two years by the country’s Institute of Public Health.

MRI Shows How Heart Changes During Deep Dives – AuntMinnie

Cardiac MRI has uncovered the unusual ability of free divers — who descend hundreds of feet into the ocean while holding their breath — to develop “compensatory mechanisms” to recover heart function within minutes of breathing again. The researchers from Germany, who presented the study at RSNA 2015 on Tuesday, likened the changes in the divers’ systolic heart function during the breath-holds to patients with systolic heart failure. The temporary suspension of breathing is known as apnea.