Welcome to the Clinical Center Grand Rounds, a weekly series of educational lectures for physicians and health care professionals broadcast from the Clinical Center at the National Institutes of Health in Bethesda, MD. The NIH Clinical Center is the world's largest hospital totally dedicated to investigational research and leads the global effort in training today's investigators and discovering tomorrow's cures. Learn more by visiting us online at http://clinicalcenter.nih.gov TODAY WE WILL HEAR FROM TWO COLLEAGUES FROM THE NATIONAL HEART, LUNG AND BLOOD INSTITUTE ADDRESSING CARDIAC HEALTH. OUR FIRST SPEAKER IS DR. TIFFANY POWELL-WILEY, TENURED TRACK INVESTIGATOR AND CHIEF OF THE SOCIAL DETERMINANTS OF OBESITY AT THE NATIONAL HEART, LUNG AND BLOOD INSTITUTE. AND SHE IS ALSO AN ADJUNCT INVESTIGATOR IN THE DIVISION OF INTRAMURAL RESEARCH OF THE NATIONAL INSTITUTE ON MINORITY HEALTH AND HEALTH DISPARITIES. DR. POWELL WILEY'S RESEARCH FOCUSES ON DETERMINE DETERMINANTS OF OBESITY AND CARDIOVASCULAR RISK FACTORS THAT CONTRIBUTE TO& RACIAL AND ETHNIC DISPARITIES IN CARDIOVASCULAR DISEASE. DR. POWELL-WILEY EARNED HER MEDICAL DEGREE FROM DUKE UNIVERSITY SCHOOL OF MEDICINE AND COMPLETED HER MASTER'S DEGREE IN PUBLIC HEALTH WITH A CONCENTRATION IN EPIDEMIOLOGY AT THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL. DURING MEDICAL SCHOOL, SHE SPENT A YEAR IN RESIDENCE AT THE NIH AS AN INTRAMURAL FELLOW IN THE CLINICAL RESEARCH TRAINING PROGRAM WHICH IS NOW THE TRANS-NIH MEDICAL RESEARCH SCHOLARS PROGRAM. PRIOR TO JOINING THE NIH IN 2011 AS AN ASSISTANT CLINICAL INVESTIGATOR, DR. POWELL-WILEY COMPLETED AN INTERNAL MEDICINE RESIDENCY AT BRIGHAM AND WOMEN'S HOSPITAL IN BOSTON AND A CARDIOLOGY FELLOWSHIP AT THE UNIVERSITY OF TEXAS SOUTHWESTERN MEDICAL CENTER IN DALLAS. THERE POWELL-WILEY ALSO SERVED AT THE UNIVERSITY OF TEXAS AND AS THE CARDIOLOGY DIVISION'S FIRST CHIEF FELLOW. DURING HER TRAINING IN DALLAS, DR. POWELL-WILEY'S RESEARCH CONCENTRATED ON PERCEPTIONS OF HEALTH AND ACCESS TO CARE AS SOCIAL DETERMINE NANTSZ DETERMINANTS OF OB ESITY. IN HER CURRENT POSITION AS CHIEF OF THE SOCIAL DETERMINANTS OF OBESITY AND CARDIOVASCULAR RISK LABORATORY, SHE FOCUSES ON IMPROVING CARDIOMETABOLIC HEALTH IN HIGH RISK COMMUNITIES IN WASHINGTON, D.C. DR. POWELL-WILEY'S RECOGNITIONS INCLUDE THE WOMEN IN CARDIOLOGY TRAINING AWARD FOR EXCELLENCE FROM THE AMERICAN HEART ASSOCIATION, AND AN NHLBI DIRECTORS' DIVERSITY AWARD. SHE BECAME A FELLOW OF THE AMERICAN HEART ASSOCIATION IN 2014 AND CURRENTLY SERVES ON THE BOARD OF ADVISERS FOR THE NIH'S MEDICAL RESEARCH SCHOLARS PROGRAM. SHE'S PUBLISHED HER RESEARCH WIDELY IN THE BIOMEDICAL LITERATURE AND ALSO SERVES AS AN EDITORIAL BOARD MEMBER OF THE JOURNAL'S CIRCULATION, AND FRONTIERS IN DIABETES. SHE WILL SPEAK TODAY ON SYSTEMS SCIENCE APPROACHES TO EVALUATE THE IMPACT OF SOCIAL DETERMINANTS OF HEALTH ON CARDIOVASCULAR RISK. OUR SECOND SPEAKER TODAY IS DR. MARCUS CHEN, WHO IS AN ASSISTANT CLINICAL INVESTIGATOR IN THE CARDIOVASCULAR AND PULMONARY BRANCH AT THE NATIONAL HEART LUNG AND BLOOD INSTITUTE. DR. CHEN EARNED HIS M.D. DEGREE FROM THE UNIVERSITY OF WISCONSIN AT MADISON, AND COMPLETED A RESIDENCY IN INTERNAL MEDICINE, AND FELLOWSHIPS IN BOTH NUCLEAR MEDICINE AND CARDIOLOGY AT THE UNIVERSITY OF COLORADO SCHOOL OF MEDICINE. DR. CHEN CAME TO THE NIH IN 2006 INITIALLY AS A CLINICAL FELLOW IN CARDIOVASCULAR MAGNETIC RESONANCE IMAGING, AND HAS BEEN ON STAFF AT THE NHLBI SINCE 2008, AS THE DIRECTOR OF CARDIOVASCULAR CT. DR. CHEN IS THE RECIPIENT OF FIVE NHLBI DIRECTORS' AWARDS AND NIH CLINICAL CENTERS AWARD FOR OUTSTANDING CLINICAL RESEARCH. HIS CLINICAL AND RESEARCH INTERESTS INCLUDE RADIATION REDUCTION, TECHNICAL DEVELOPMENT OF NEW WILL IMAGING IMAGING METHODS AND MULTI-MODALITY NONINVASIVE CARDIAC IMAGING. AS AN INVESTIGATOR, DR. CHEN HAS PUBLISHED OVER 70 PEER REVIEWED PAPERS, MANY OF WHICH ADDRESS THE TOPIC OF RADIATION REDUCTION, AND HE SERVES CURRENTLY AS AN ASSOCIATE EDITOR OF THE JOURNAL OF CARDIOVASCULAR COMPUTED TOMOGRAPHY. DR. CHEN WILL SPEAK TODAY ON ULTRA LOW RADIATION DOSE COMPUTED TOMOGRAPHY IMAGING, HOW LOW CAN WE GO. LET'S BEGIN BY WELCOMING DR. POWELL, OUR FIRST SPEAKER. [APPLAUSE] >> THANK YOU SO MUCH. I HAVE NO RELEVANT DISCLOSURES TODAY. SO THE OBJECTIVES OF THE TALK TODAY WILL BE FIRST TO DISCUSS SOCIAL ENVIRONMENT AS A CONTRIBUTOR TO CARDIOMETABOLIC HEALTH DISPARITIES, THEN TO DESCRIBE SOME COMMUNITY-BASED PARTICIPATORY RESEARCH THAT WE'RE DOING TO CHARACTERIZE ENVIRONMENTAL BARRIERS TO CARDIOMETABOLIC HEALTH, PARTICULARLY IN AT RISK AREAS OF WASHINGTON, D.C., AND FINALLY TO ILLUSTRATE THE ROLE OF SYSTEMS SCIENCE MODELING TO OPTIMIZE INTERVENTIONS TARGETING CARDIOMETABOLIC HEALTH FOR THESE RESOURCE LIMITED COMMUNITIES. SO AS WE KNOW, HEALTH DISPARITIES IN CARDIOVASCULAR OUTCOMES EXIST BY RACE AND ETHNICITY BUT THEY ALSO PERSIST. DATA FROM THE REGARDS COHORT SHOW SIGNIFICANT DIFFERENCES BETWEEN BLACKS AND WHITES RELATED TO FATAL CORONARY HEART DISEASE, HOWEVER, IN THESE MODELS, WHEN THE GREATER RISK FACTOR BURDEN AMONG AFRICAN-AMERICANS WAS ADJUSTED FOR IN THE MODELS, YOU ACTUALLY SEE NO LONGER A SIGNIFICANT DIFFERENCE BETWEEN RATES OF FATAL CORONARY HEART DISEASE BETWEEN BLACKS AND WHITES. SO IT SUGGESTS THAT WE NEED TO BETTER UNDERSTAND THE REASONING BEHIND THE GREATER BURDEN OF RISK FACTORS, BUT ALSO WAYS IN WHICH WE CAN INTERVENE ON THESE RISK FACTOR BURDEN. AND SO THIS RECENT SCIENTIFIC STATEMENT PUT FORWARD BY THE AMERICAN HEART ASSOCIATION REALLY HIGHLIGHTS THE WORK THAT NEEDS TO BE DONE TO TARGET CARDIOVASCULAR HEALTH IN AFRICAN-AMERICANS. THEY STATE TO MAKE PROGRESS TOWARD PROMOTING HEALTH EQUITY, IT WILL REQUIRE COLLABORATIONS ACROSS MULTIPLE DISCIPLINES, BOTH WITHIN AND OUTSIDE OF THE TRADITIONAL UMBRELLA OF HEALTHCARE PROVIDERS GIVEN THE COMPLEX HISTORICAL, SOCIAL, AND ECONOMIC REASONS WHY AFRICAN-AMERICANS EXPERIENCE POOR CARDIOVASCULAR HEALTH. AND SO WITH THIS IN MIND, WE'VE REALLY TRIED TO DEVELOP A MULTIDISCIPLINARY APPROACH TO UNDERSTANDING THE RELATIONSHIP BETWEEN SOCIAL DETERMINANTS OF HEALTH AND OBESITY IN CARDIOVASCULAR RISK IN MY RESEARCH GROUP HERE. WE FOCUSED ON NEIGHBORHOOD ENVIRONMENT IN PARTICULAR AS A SOCIAL DETERMINANT, WHETHER IT BE PERCEIVED ENVIRONMENT OR THE PSYCHOSOCIAL FACTORS THAT RELATE TO PERCEPTIONS OF ENVIRONMENT OR MORE OBJECTIVE MEASURES OF PHYSICAL AND SOCIAL NEIGHBORHOOD ENVIRONMENT. WE'VE LOOKED SPECIFICALLY AT HOW NEIGHBORHOOD ENVIRONMENT RELATES TO HEALTH BEHAVIORS SUCH AS PHYSICAL ACTIVITY, DIET AND SEDENTARY TIME, AND ULTIMATELY HOW THAT RELATES TO DEVELOPMENT OF CARDIOVASCULAR RISK FACTORS, INCLUDING OBESITY AND DIABETES. KEEPING IN MIND THE NEED FOR A MULTIDISCIPLINARY APPROACH, WE'VE USED MULTIPLE METHODS, WHETHER IT BE EPIDEMIOLOGIC STUDIES TO UNDERSTAND THIS RELATIONSHIP, BUT ALSO COMMUNITY ENGAGEMENT AND HEALTH INFORMATICS TO NOT ONLY UNDERSTAND THE RELATIONSHIP BETWEEN NEIGHBORHOOD ENVIRONMENT AND CARDIOMETABOLIC RISK BUT ALSO THINKING ABOUT WAYS TO INTERVENE. OUR NEWEST EFFORTS WHICH I WON'T NECESSARILY TALK ABOUT TODAY ARE MORE TRANSLATIONAL, REALLY THINKING ABOUT WHAT ARE SOME OF THE PHYSIOLOGIC MECHANISMS BY WHICH NEIGHBORHOOD ENVIRONMENT RELATES TO THE DEVELOPMENT OF CARDIOMETABOLIC RISK. SO MY FOCUS TODAY WILL BE ON LONGITUDINAL STUDIES THAT WE'VE USED TO LOOK AT THIS RELATIONSHIP BETWEEN ENVIRONMENT AND CARDIOMET BOLMETABOLIC RISK AS WELL AS OUR COMMUNITY-BASED EFFORTS AND SOME SIMULATION MODELING THAT WE'RE USING TO BETTER UNDERSTAND AND DESIGN INTERVENTIONS. SO WHY HAVE WE FOCUSED ON NEIGHBORHOOD? SOCIOECOLOGICAL MODEL PUT FORWARD THAT NEIGHBORHOOD INFLUENCES BOTH INDIVIDUAL LEVEL ENERGY EXPENDITURE AND FOOD INTAKE, BUT ALSO PREVALENT OBESITY. AND REALLY SERVES AS A POTENTIAL SOURCE FOR TARGETING MULTILEVEL INTERVENTIONS. WHEN WE THINK OF SOCIAL ENVIRONMENT IN PARTICULAR, WE CAN THINK OF FOUR SPECIFIC TYPES OF MEASURES OF SOCIAL ENVIRONMENT. MEASURES OF PERCEIVED SAFETY OR HOW INDIVIDUALS -- HOW SAFE INDIVIDUALS FEEL IN THEIR ENVIRONMENT, ACTUAL OBJECTIVE MEASURES OF CRIME, MEASURES OF SOCIAL COHESION OR THE SENSE OF COMMUNITY INDIVIDUALS FEEL WITHIN A NEIGHBORHOOD, OR SOCIAL NORMS WITHIN A COMMUNITY. ALL OF THESE ARE PROPOSED TO INFLUENCE BIOLOGIC FACTORS INCLUDING BODY MASS INDEX AND ULTIMATELY CLINICAL CARDIOVASCULAR DISEASE AS PUT FORWARD BY FRAMEWORK FROM ROUX. OUR LONGITUDINAL STUDIES FOCUSED ON THE RELATIONSHIP OF THE NEIGHBORHOOD ENVIRONMENT AND CARDIOMETABOLIC RISK HAVE REALLY FOCUSED ON USING DATA FROM ETHNICALLY DIVERSE ADULT POPULATIONS, AND THE REASON WHY WE FOCUS ON LONGITUDINAL DATA IS BECAUSE IT PROVIDES A NATURAL EXPERIMENT WHERE WE CAN SEE HOW CHANGES IN ENVIRONMENT OVER TIME RELATE TO CHANGES IN CARDIOMETABOLIC RISK, BUT WE CAN ALSO SEE HOW MOVING TO DIFFERENT NEIGHBORHOODS RELATES TO CHANGES IN RISK. IN THE WORK I'LL TALK ABOUT TODAY WAS DONE IN THE MULTIETHNIC STUDY OF ATHEROSCLEROSIS, WHICH IS AN NHLBI SPONSORED COHORT STUDY WITH SIX SITES THROUGHOUT THE UNITED STATES. THE WORK THAT I'LL FOCUS ON TODAY OCCURRED BASED ON DATA FROM CHICAGO, THE COHORT IN CHICAGO, ILLINOIS. WHAT WE SOUGHT TO UNDERSTAND WITH THIS STUDY WAS HOW CHANGES IN CRIME OVER TIME RELATED TO CHANGES IN ADIPOSITY IN THE MESA PARTICIPANTS. THE REASON WE LOOKED AT CHICAGO IN PARTICULAR WAS BECAUSE WE HAD OBJECTIVE MEASURES OF NEIGHBORHOOD CRIME FOR THAT POPULATION. WE HAD LONGITUDINAL DATA FROM 2000 TO 2012, AND OUR COHORT INCLUDED AROUND 670 PARTICIPANTS IN THE STUDY. FOR THIS PROJECT, WE AGAIN WANTED TO FOCUS ON SOCIAL ENVIRONMENT AS MEASURED BY NOT ONLY POLICE REPORTED CRIME, BUT INDIVIDUAL LEVEL SAFETY. NOT ONLY WERE WE ABLE TO LOOK AT INDIVIDUAL LEVEL SAFETY BUT WE WERE ABLE TO LOOK AT NEIGHBORHOOD LEVEL SAFETY AS WELL. AND WE HYPOTHESIZED THAT THERE WOULD BE A RELATIONSHIP BETWEEN CHANGES IN NEIGHBORHOOD SOCIAL ENVIRONMENT AND CHANGES IN ADIPOSITY AS MEASURED BY BMI AND WAIST CIRCUMFERENCE INDEPENDENT OF LIFESTYLE FACTORS INCLUDING PHYSICAL ACTIVITY AND DIETARY INTAKE. SPECIFICALLY WE THOUGHT THAT GREATER INCREASES IN CRIME AND DECREASES IN SAFETY OVER TIME WOULD BE ASSOCIATED WITH INCREASING BODY MASS INDEX AND WAIST CIRCUMFERENCE. FOR THE MEASURES OF PERCEIVED SAFETY, WE LOOKED AT SURVEY-BASED MEASURES OF INDIVIDUAL LEVEL SAFETY, BUT ALSO A MEASURE OF NEIGHBORHOOD LEVEL SAFETY AND THIS WAS BASED ON AGGREGATED DATA OF PERCEIVED SAFETY FROM THE PARTICIPANTS IN THE MESA STUDY, BUT ALSO INDIVIDUALS WHO LIVED IN THE CENSUS TRACTS WHERE MESA PARTICIPANTS LIVED. THIS ALLOWED FOR REDUCTION IN SAME SOURCE BIAS IN CREATING A MEASURE OF NEIGHBORHOOD LEVEL SAFETY. AND IN THE COHORT, HIGHER SCORES OF PERCEIVED SAFETY WAS ASSOCIATED WITH GREATER PERCEIVED SAFETY, AND A CRIME RATE WAS CALCULATED BASED ON A 1-MILE BUFF ER AROUND EACH INDIVIDUAL'S HOME ADDRESS TO CALCULATE A ONE-YEAR CRIME RATE BASED ON POLICE REPORTED CRIME DATA. WHAT WE FOUND IN THE STUDY WAS THAT FOR AN INCREASE IN INDIVIDUAL LEVEL AND NEIGHBORHOOD LEVEL SAFETY FOR EACH UNIT INCREASING THESE FACTORS, WE SAW SIGNIFICANT DECREASE IN BODY MASS IB DEX IN THE MESA COHORT. IN CONTRAST, THERE WAS NO SIGNIFICANT RELATIONSHIP BETWEEN TOTAL CRIME CHANGES AND CHANGES IN BMI OVER TIME. WHEN WE LOOKED AT SEX STRATIFIED MODELS, WE SAW THAT FOR WOMEN, CHANGES IN INDIVIDUAL LEVEL SAFETY WERE ASSOCIATED WITH SIGNIFICANT DECREASES IN BODY MASS INDEX, BUT FOR MEN, CHANGES IN NEIGHBORHOOD LEVEL SAFETY WERE ASSOCIATED WITH CHANGES IN BODY MASS INDEX. SUGGESTING THERE MAY BE DIFFERENCES IN MECHANISM BY WHICH NEIGHBORHOOD SAFETY OR PERCEIVED SAFETY RELATES TO ADIPOSITY BY SEX. WE THEREFORE SHOWED THAT CHANGES IN PERCEIVED SAFETY BUT NOT CHANGES IN MORE OBJECTIVE MEASURES OF CRIME AA PEER TO IMPACT ADIPOSITY AND THIS AGAIN PROVIDED ADDITIONAL EVIDENCE THAT EXPOSURE TO ADVERSE NEIGHBORHOOD CONDITIONS RELATED TO THE DEVELOPMENT OF CARDIOMETABOLIC RISK FACTORS WITHIN A COMMUNITY, AND HIGHLIGHTED PERCEIVED SAFETY AS A POTENTIAL TARGET FOR INTERVENTION FOR IMPROVING CARDIOMETABOLIC HEALTH IN AT RISK NEIGHBORHOOD COMMUNITIES. SO AS WE THOUGHT ABOUT HOW TO DEVELOP INTERVENTIONS THAT PROMOTE INCREASES IN PERCEIVED SAFETY, WE LOOK TO COMMUNITY-BASED PARTICIPATORY RESEARCH AS A WAY TO FIRST IDENTIFY OR GAIN GREATER INSIGHTS INTO THE ROLE OF SAFETY AND SOCIAL ENVIRONMENT ON CARDIOMETABOLIC RISK, PARTICULARLY THROUGH COMMUNITY ENGAGEMENT IN WASHINGTON, D.C., AND SPECIFICALLY WANTED TO UNDERSTAND HOW SOCIAL ENVIRONMENT SERVED AS A BARRIER TO PHYSICAL ACTIVITY AND HEALTHY DIET IN THESE COMMUNITIES IN WASHINGTON, D.C. AND FINALLY, COULD WE DEVELOP OR EVEN RECOMMEND INTERVENTIONS THAT TARGET HEALTH BEHAVIORS AND ACCOUNT FOR SOCIAL ENVIRONMENT IN THESE COMMUNITIES. SO WORK HAS BEGAN WITH CARDIOVASCULAR HEALTH AND NEEDS ASSESSMENT IN WASHINGTON, D.C., AND SPECIFICALLY WE TARGETED THE WARDS OF WASHINGTON, D.C. WHERE OBESITY WAS MOST PREVALENT. THESE ARE WARDS 5, 7 AND # IN 7 AND 8 IN THE COUNTY. THIS PROJECT WAS DEVELOPED WITH COMMUNITY-BASED PARTICIPATORY RESEARCH PRINCIPLES, WE STARTED WORKING WITH A COMMUNITY ADVISORY BOARD WHO PROVIDED INPUT ON THE DESIGN AND IMPLEMENTATION OF EACH STEP OF THE PROJECT. ASSESSMENTS WITHIN COMMUNITY CHURCHES AND LOOKED AT NOT ONLY CARDIOVASCULAR RISK IN THE POPULATION BUT ALSO WE MEASURED ENVIRONMENTAL AND PSYCHOSOCIAL FACTORS THAT RELATE TO CARDIOMETABOLIC HEALTH. ULTIMATELY, WE WERE ALSO ABLE TO ASSESS SPECIFIC TOOLS FOR INTERVENTION, AND WE WERE ABLE TO USE IN PARTICULAR QUALITATIVE DATA TO GET INPUT ON POTENTIAL TOOLS FOR PROMOTING BEHAVIOR CHANGE BUT ALSO BARRIERS TO IMPROVING DIET AND PHYSICAL ACTIVITY WITHIN THE COMMUNITY. THIS ASSESSMENT AGAIN WAS AIMED AT REALLY DEVELOPING COMMUNITY-BASED INTERVENTION, INTERVENTIONS WITHIN THESE SPECIFIC AREAS OF WASHINGTON, D.C. AND SO WITH THIS HEALTH AND NEEDS ASSESSMENT, WE HYPOTHESIZE THAT THIS QUALITATIVE DATA, PARTICULARLY THROUGH FOCUS GROUPS, WOULD I A LOW US TO ENGAGE COMMUNITY MEMBERS IN AREAS OF WASHINGTON, D.C. IN A WAY TO PROVIDE CONTEXTUAL INFORMATION ON SPECIFIC BARRIERS TO HEALTH BEHAVIORS AS WE DEVELOP TAILORED INTERVENTIONS. AND SO ONE THING THAT WE HAVE FOUND MOST RECENTLY IN OUR GATHERING QUALITATIVE DATA AROUND WAYS IN WHICH WE CAN MESSAGE INDIVIDUALS TO PROMOTE PHYSICAL ACTIVITY, WE FOUND THAT CRIME AND SAFETY AGAIN CAME UP AS POTENTIAL BARRIERS TO PHYSICAL ACTIVITY. FOR INSTANCE, ONE PARTICIPANT IN A RECENT FOCUS GROUP NOTED, I USED TO RIDE MY BIKE BY MYSELF AND NOW IT'S JUST SITTING BECAUSE I'M NOT GOING TO RIDE BY MYSELF. SO SAFETY IS A REAL CONCERN. WE HAVE THE COMMUNITY-BASED DATA THAT REALLY HIGHLIGHTS SAFETY AND CRIME AS POTENTIAL BARRIERS TO PHYSICAL ACTIVITY. WE HAVE THE DATA FROM OUR EPIDEMIOLOGIC STUDIES THAT SUGGEST THAT PERCEIVED SAFETY PROMOTES CHANGES IN ADIPOSITY, SO WHAT WE WANTED TO UNDERSTAND WAS HOW COULD WE UTILIZE BOTH TYPES OF DATA TO BETTER UNDERSTAND INTERVENTIONS, BUT ALSO TO POTENTIALLY TEST INTERVENTIONS BEFORE ACTUAL IMPLEMENTATION. SO THAT'S WHERE OUR SYSTEM SCIENCE APPROACHES COME INTO PLAY, BECAUSE IT ALLOWS US TO REALLY ACCOUNT FOR THE COMPLEXITIES OF THESE RELATIONSHIPS AND DEVELOP COMPUTATIONAL MODELS THAT CAN TEST INTERVENTIONS BEFORE ACTUAL IMPLEMENTATION. TAKING A STEP BACK, WE KNOW OBESITY IS A VERY COMPLEX SYSTEM. THIS GRAPHIC PUT FORWARD BY THE OBESITY SOCIETY REALLY HIGHLIGHTS THE INDIVIDUAL LEVEL FACTORS THAT RELATE TO THE DEVELOPMENT OF OBESITY, BUT ALSO THE INTERPERSONAL ENVIRONMENTAL FACTORS. MY GOAL FOR YOU IS NOT TO READ EVERY FACTOR THAT THAT'S LISTED BUT JUST THE SHEER NUMBERS, THINKING ABOUT INTERVENTION -- HOW DO WE REALLY TAKE INTO ACCOUNT THE WILL MANY FACTORS THAT CONTRIBUTE TO THE PROCESS? AND SO THAT'S WHERE THE SYSTEM SCIENCE MODELING COMES INTO PLAY. IT REALLY ALLOWS US TO ACCOUNT FOR THE COMPLEXITY RELATED TO FACTORS CONTRIBUTING TO OBESITY. SO WE KNOW AS I SAID THAT THERE ARE MULTIPLE LEVELS THAT INFLUENCE OBESITY BOTH AT THE INDIVIDUAL, INTERPERSONAL AND ENVIRONMENTAL LEVEL, BUT THERE ARE ALSO DIFFERENT MECHANISMS AT EACH LEVEL, SO SYSTEM SCIENCE MODELING, WHETHER IT BE AGENT BASED MODELING OR SYSTEMS DYNAMIC MODELING ALLOWS US TO ACCOUNT FOR THE INTERRELATED LEVELS THAT INFLUENCE OBESITY. SO WE HAVE FOCUSED ON PARTICULAR AGENT BASED MODELING AS A WAY TO SIMULATE EFFECTS OF INTERVENTIONS ON COMMUNITY MEMBERS WITHIN D.C. THIS COMPUTATIONAL MODELING METHOD ALLOWS US TO SIMULATE INDIVIDUALS WITHIN A COMMUNITY AS AGENTS WITHIN THE MODEL. THESE AGENTS CAN BE AUTONOMOUS, THEY CAN HAVE THEIR OWN DECISION-MAKING PROCESS AROUND HEALTH BEHAVIORS, BUT THEY CAN ALSO INTERACT WITH EACH OTHER TO INFLUENCE THE POPULATION HEALTH BEHAVIORS AS A WHOLE. AGENTS WITHIN THE MODEL CAN ALSO INTERACT WITH THEIR ENVIRONMENT AND BURY THEIR BEHAVIORS BASED ON SOCIAL OR ENVIRONMENTAL QUEUES WITHIN THE SYSTEM. AND ULTIMATELY, THE ENVIRONMENTAL OR EVEN INTERPERSONAL CHANGES THAT OCCUR WITHIN THE MODEL CAN AFFECT THE HEALTH BEHAVIORS OF THE POPULATION AND THE MODEL AS A WHOLE, AND ULTIMATELY THE OUTCOMES, HEALTH OUTCOMES FOR THE POPULATION. THE FIRST MODEL THAT WAS DEVELOPED WAS THE VPOP D.C. THIS WAS DEVELOPED IN COLLABORATION WITH THE GLOBAL OBESITY PREVENTION CENTER AT JOHNS HOPKINS. WHAT WE DID IN THIS PROJECT WAS TO DEVELOP A GEOSPATIALLY EXPLICIT AGENT BASED MODEL THAT REPRESENTED THE WARDS IN WASHINGTON, D.C. THAT WE WERE TARGETING. AND IT ALLOWED US TO INITIALLY LOOK AT HOW CRIME WITHIN THESE COMMUNITIES IMPACTED NOT ONLY PHYSICAL ACTIVITY LOCATIONS, BUT ALSO THE LEVELS OF LEISURE TIME PHYSICAL ACTIVITY IN THE POPULATION AND OBESITY. AND WE FOCUS ON AFRICAN-AMERICAN WOMEN, AGES 18-65, IN THIS MODEL. SO WHAT THE AGENTS REPRESENTED WERE REALLY HOUSEHOLDS WITHIN THESE COMMUNITIES, BUT THEY ALSO INTERACTED WITH PHYSICAL ACTIVITY LOCATIONS INCLUDED IN THE MODEL, AS WELL AS WERE ABLE TO INCLUDE CRIME LOCATIONS BASED ON CRIME REPORTS FROM WASHINGTON, D.C. POLICE. SO JUST TO GIVE A SENSE OF HOW THE AGENT BASED MODEL WORKED, THERE WERE TWO MAIN STEPS IN THE MODEL. THE FIRST WAS WHERE AN AGENT AGAIN REPRESENTING A WOMAN, AFRICAN-AMERICAN WOMAN IN THE COMMUNITY, WHERE SHE WOULD DECIDE WHERE SHE WOULD DO PHYSICAL ACTIVITY. IF SHE DECIDED TO CONDUCT PHYSICAL ACTIVITY AT HOME, THEN SHE WOULD NOT BE INFLUENCED BY ENVIRONMENTAL FACTORS. HOWEVER, IF SHE DECIDED TO CONDUCT PHYSICAL ACTIVITY OUTSIDE OF THE HOME, EITHER IN A RECREATION SHEN TER OR IN A CENTER OR A PA RK, SHE WOULD BE INFLUENCED BY SPECIFIC CRIME LOCATIONS WITHIN THE -- NEAR THE PHYSICAL ACTIVITY LOCATION. SO A CRIME OCCURRING IN THE COMMUNITY COULD AFFECT PHYSICAL ACTIVITY THE IN SPECIFIC WAYS. WE MODELED IT SO THAT THE CRIME COULD AFFECT BY DURATION, SPECIFICALLY THE AMOUNT OF TIME THAT CRIME WOULD REDUCE THE LIKELIHOOD OF CONDUCTING PHYSICAL ACTIVITY AT THE SPECIFIC SITE. IT COULD ALSO REDUCE THE PROBABILITY OF CONDUCTING LEISURE TIME PHYSICAL ACTIVITY BASED ON THE TYPE OF CRIME, AND THIS WAS WHAT WE TERMED THE EFFECT OF THE CRIME. AND FINALLY, IT COULD INFLUENCE THE LIKELIHOOD OF PHYSICAL ACTIVITY BY ITS RADIUS, SO REALLY IT WAS THE RADIAL DISTANCE AROUND A CRIME EVENT THAT COULD LIMIT THE LIKELIHOOD OF DOING PHYSICAL ACTIVITY AT A SPECIFIC LOCATION. ONCE AN AGENT IN THE MODEL DECIDED TO DO -- WHERE TO DO PHYSICAL ACTIVITY, THEY WOULD THEN DECIDE HOW MUCH PHYSICAL ACTIVITY TO DO, AND THERE WAS A SPECIFIC PROBABILITY OF DOING EITHER MODERATE OR VIGOROUS ACTIVITY AT HOME OR AT A RECREATIONAL CENTER OR PARK. AND ONCE THE TYPE OF PHYSICAL ACTIVITY WAS DECIDED AND THE DURATION OF PHYSICAL ACTIVITY WAS DECIDED, WE WERE ABLE TO CALCULATE THE CALORIC EXPENDITURE FOR THAT AGENT AND ULTIMATELY USE A METABOLIC MODEL TO CALCULATE THE OBESITY LEVEL FOR THAT AGENT. SO WE WERE ALSO ABLE TO VARY NOT ONLY THE CRIME PARAMETERS IN THE MODEL, BUT THE BASELINE PROPENSITY FOR EXERCISE FOR EACH AGENT. THIS IS WHAT REPRESENTED OTHER FACTORS OUTSIDE OF CRIME THAT WOULD INFLUENCE DAILY EXERCISE. SO THESE WERE BARRIERS SUCH AS THE COST OF EXERCISE, OTHER TIME COMMITMENTS WITHIN A PERSON'S SCHEDULE OR THE PRESENCE OF OTHER -- OF CHRONIC DISEASES THAT COULD LIMIT THEIR LEVELS OF PHYSICAL ACTIVITY. SO WHAT WE WERE ABLE TO TEST IN THE MODEL WERE DIFFERENT SCENARIOS BY CHANGING THE BASELINE EXERCISE PRO PENS ITY, PROPENSITY. THIS RANGED FROM A 25% LIKELIHOOD OF CONDUCTING PHYSICAL ACTIVITY ON ANY GIVEN DAY TO 100% LIKELIHOOD. SO WHAT WE FOUND IS AT THE BASELINE EXERCISE PROPENSITY OF 25%, WHEN WE MAXIMIZE CRIME REDUCTION SO THAT THE HIGHEST PERCENTAGE OF PHYSICAL ACTIVITY LOCATIONS WERE AVAILABLE, WE WOULD SEE A VERY MODEST REDUCTION IN OBESITY OVER ONE YEAR, .8%. HOWEVER, WHEN WE DOUBLED BASELINE EXERCISE PROPENSITY TO 50%, AGAIN MAXIMIZING THE AVAILABILITY OF PHYSICAL ACTIVITY LOCATIONS, WE COULD SEE A 9% REDUCTION IN OBESITY OVER A ONE-YEAR PERIOD IN THE POPULATION. SO THIS REALLY HIGHLIGHTED THAT EXERCISE PROPENSITY WORKED HAND IN HAND WITH CRIME REDUCTIONS IN NOT ONLY INCREASING THE LOCATION ACCESSIBILITY FOR PHYSICAL ACTIVITY, BUT ALSO ULTIMATELY IMPACTING LEISURE TIME PHYSICAL ACTIVITY AND OBESITY IN THE POPULATION. AND REALLY SUGGESTED THAT WE NEEDED MULTILEVEL APPROACHES THAT NOT ONLY TARGET CRIME IN AND OF ITSELF BUT ALSO THE INDIVIDUAL LEVEL AND ENVIRONMENTAL BARRIERS TO PHYSICAL ACTIVITY OUTSIDE OF CRIME. SO IN THINKING ABOUT THE TYPES OF INTERVENTIONS THAT MIGHT HELP IN NOT ONLY REDUCING CRIME BUT ALSO IN IMPROVING SAFETY AND REDUCING INDIVIDUAL LEVEL BARRIERS TO PHYSICAL ACTIVITY, ONE COULD THINK OF THINGS SUCH AS URBAN RENEWAL WHERE YOU CAN SEE CRIME REDUCTION BUT YOU CAN ALSO SEE ECONOMIC OPPORTUNITY THAT PROMOTES GREATER OPPORTUNITY AT THE INDIVIDUAL LEVEL FOR PROMOTING PHYSICAL ACTIVITY AND ULTIMATELY FOR IMPROVING CARDIOVASCULAR HEALTH. SO THIS WORK IS CONTINUING TO BETTER UNDERSTAND HOW WE CAN USE SYSTEM SCIENCE MODELING AS WE THINK ABOUT THE DEVELOPMENT OF A SPECIFIC INTERVENTION IN THE COMMUNITIES WHERE WE'RE WORKING. OUR GOAL IS TO REALLY START TO IDENTIFY WAYS IN WHICH WE CAN DESIGN A PHYSICAL ACTIVITY INTERVENTION FOR AFRICAN-AMERICAN WOMEN IN THESE WARDS IN D.C. SO WE'RE GATHERING ADDITIONAL QUALITATIVE DATA TO UNDERSTAND PERCEIVEED BARRIERS WITHIN THE NEIGHBORHOOD TO PHYSICAL ACTIVITY, AND THIS JESUS ILLUSTRATES A WALKING GROUP THAT WE HAD WHERE WOMEN IN THE COMMUNITY ACTUALLY POINTED OUT BARRIERS TO PHYSICAL ACTIVITY. THIS IS AIDING US IN THINKING ABOUT MESSAGING AROUND PHYSICAL ACTIVITY BUT ALSO ACTUALLY REFINING THE SIMULATION MODEL THAT WE'VE DEVELOPED. WE'RE EXPANDING OUR SIMULATION MODEL SO IT ALSO INCLUDES ALL OF WASHINGTON, D.C., NOT JUST WARDS 5, 7 AND 8, SO WE CAN POTENTIALLY COMPARE ACROSS SOASH YEAR ECONOMIC LEVELS WITHIN THE CITY. AND FINALLY, WE'VE STARTED TO USE THIS AGENT BASED MODEL TO TEST A SPECIFIC INTERVENTION WHERE WE PROVIDE MORE LOCATION-SPECIFIC MESSAGING AROUND PHYSICAL ACTIVITY, TO SEE HOW THAT MIGHT INFLUENCE DECISION-MAKING AND ULTIMATELY LEVELS OF PHYSICAL ACTIVITY AND OBESITY IN THE COMMUNITY. SO OUR HOPE IS THAT WE CAN TAKE THE OBSERVATIONAL DATA THAT WE'VE GATHERED THROUGH COMMUNITY ENGAGEMENT, EPIDEMIOLOGIC STUDIES AND THE QUALITATIVE STUDIES TO USE SIMULATION MODELING AND INTERVENTION DESIGN AND IMPLEMENTATION AND POTENTIALLY INFLUENCE POLICY DEVELOPMENT WITHIN WASHINGTON, D.C. MY HOPE IS THAT THIS REALLY CAN BE AN ITERATIVE PROCESS WHERE WHAT WE LEARN FROM OUR INTERVENTIONS GOES BACK TO HOW WE -- DEFINING HOW WE GATHER THE OBSERVATIONAL WILL DATA WITHIN THE COMMUNITY. ULTIMATELY I SEE SYSTEM SCIENCE MODELING IS REALLY A TOOL IN ADDRESSING DISPARITIES IN CARDIOVASCULAR HEALTH, WHERE WE USE THE OBSERVATIONAL GEOSPATIAL AND QUALITATIVE DATA IN MODELING TO DEVELOP TAILORED INTERVENTIONS. AND WE CAN ALSO THINK OF USING SYSTEM SCIENCE MODELING AS A WAY TO TEST POTENTIAL INTERVENTIONS PRIOR TO IMPLEMENTATION, AND REALLY BEFORE COMMITTING SIGNIFICANT RESOURCES TO A SPECIFIC INTERVENTION, AND THE HOPE IS THAT ALL OF THIS WORK CAN REALLY HARNESS THE OPPORTUNITIES WITH BIG DATA IN ADDRESSING DISPARITIES FOR THESE COMMUNITIES. SO I'D LIKE TO ACKNOWLEDGE IN PARTICULAR MY RESEARCH GROUP AND ALL OF THE COLLABORATORS WHO HAVE WORKED WITH ME ON THESE PROJECTS. I'D ALSO LIKE TO ACKNOWLEDGE THE COMMUNITY ADVISORY BOARD WITH WHOM WE WORK, THANK YOU SO MUCH FOR YOUR ATTENTION, AND THIS IS OUR RESEARCH GROUP. SO THANK YOU VERY MUCH. [APPLAUSE] IN TERMS OF DISCLOSURES, I HAVE A RESEARCH AGREEMENT WITH KENT MEDICAL. THESE ARE LEARNING OBJECTIVES. WE'LL GET STARTED HERE. SO RECENTLY THERE WAS A 6-YEAR-OLD WHO HAD RECURRENT LUNG INFECTIONS, AND THE TEAM ORDERED CHEST CT, AND THIS PATIENT GOT A LOW RADIATION DOSE CHEST C T, AND THEY NOTICED SOME CALCIUM IN THE HEART THERE. BUT THE PRIMARY TEAM WANTED TO KNOW, WHAT OTHER PARTS OF THE BODY HAD CALCIUM IN THIS YOUNG CHILD BEING SEEN HERE. SO THEY REQUESTED AN ULTRA LOW DOSE SCAN TO SEE WHAT PARTS OF THE BODY WERE AFFECTED. AND WA WE DID IS WE DID A SCAN THAT WAS OVER FIVE TIMES THE LENGTH OF THAT CHEST CT, BUT THE RADIATION LEVELS, THE DLP, THE MEASURE OF RADIATION, BASICALLY HOW MUCH RADIATION THE SCANNER UPLOADED, BUT WE WERE ABLE TO DO A SCAN THAT WAS 560 TIMES THE LENGTH OF THAT CT SCAN, BUT ONLY REPRESENTED 25% OF RADIATION DOSE. AND WE WERE ABLE TO PROVIDE CRITICAL CLINICAL INFORMATION TO THE TEAM, AND AT THE SAME TIME, REDUCE THE RISK FOR THAT INDIVIDUAL PATIENT. BECAUSE HE WAS ONLY 6, AND HE'S PROBABLY -- WILL PROBABLY BE HAVING REPEATED MEDICAL EVALUATION, CT SCANS FOR THE REST OF HIS LIFE. SO EARLIER I ASKED HOW MANY PEOPLE ORDER CT SCANS. THIS IS JUST A SCHEMATIC OF HOW POPULAR CT SCANNING IS IN THE U.S. STARTING FROM THE EARLY 90s, THIS DATA IS UP TO 2011, BUT BASICALLY YEAR AFTER YEAR, THIS MEANT 10% GROWTH IN THE ACT IMAGING DONE. THIS IS DESPITE THE U.S. POPULATION ONLY INCREASING LESS THAN 1%. AND IF YOU LOOK AT THE 2011 DATA, IT WAS ABOUT 85 MILLION SCANS DONE IN THE U.S., OVER 300 MILLION PEOPLE, SO ON AVERAGE, ONE IN FOUR PEOPLE IS GETTING A CT SCAN. EVERY YEAR, THERE'S ALWAYS AN ARTICLE IN THE "NEW YORK TIMES" ABOUT RISKS OF RADIATION FROM MEDICAL IMAGING. LAST YEAR "CONSUMER REPORTS" EVEN HAD A WHOLE ARTICLE, IT, THE SURPRISING DANGERS OF CT SCANs AND X-RAYs. SO THIS INFORMATION IS BOTH IN THE LAY PRESS AND ALSO IN THE SCIENTIFIC PRESS. SO WITH CARDIAC CT, IT HAS A VERY HIGH ACCURACY. WE CAN DIAGNOSE CORONARY DISEASE, WE CAN EXCLUDE CORONARY DISEASE, THERE'S A GOOD PROGRESS KNOW SIEVE IF YOU HAVE OBSTRUCTIVE DISEASE. HOWEVER, ABOUT 10 YEARS AGO, THERE WAS A LANDMARK PAPER IN JAMA THAT REALLY BROUGHT TO LIGHT SOME OF THESE DANGERS FROM CARDIAC CT IMAGING, BECAUSE AT THIS TIME, CARDIAC CT WAS BECOMING MORE AND MORE POPULAR. BASICALLY, IF UH-UH WERE IF YOU WERE A 20-YEAR-OLD FEMALE, BECAUSE BREAST TISSUE IS RIGHT IN FRONT OF YOUR HEART, YOUR RISK OF DEVELOPING CANCER FROM THAT CARDIAC CT IS ONE IN 143. ET CETERA LESSLESS IF YOU'RE MALE RATHER T HAN FEMALE, AND THE RISK IS HIGHER WHEN YOU'RE YOUNGER BECAUSE THE IDEA IS THAT RADIATION INDUCES A MUTATION IN YOUR DNA, AND OVER TIME, THAT WILL MANIFEST INTO POTENTIALLY CANCER. SO THE OLDER YOU GET, THE RISK IS LOWER, AND THEN THE CHANCES OF YOU DYING OF SOMETHING ELSE OTHER THAN CANCER IS HIGHER. ALSO AROUND THAT TIME, THERE WAS A REGISTRY CALLED THE PROTECTION 1 STUDY, WHERE THEY SURVEYED 50 SITES WHO WERE PUBLISHING IN CARDIAC CT. SO THESE WERE ACADEMIC SITES, THEY KNEW WHAT THEY WERE DOING, AND THEY SURVEYED THEM TO SEE HOW MUCH RADIATION WAS BEING USED. SO ON THE Y AXIS IS HOW MUCH RADIATION, AND THESE ARE INDIVIDUAL SITES GROUPED BY TYPE OF CT SCANNER, AND IT'S BASICALLY THE MEDIAN AMOUNT OF RADIATION AND THEN WHAT THE ERROR RANGE IS FOR THE EXAMS. SO THESE ARE ABOUT 2,000 DIFFERENT EXAMS, AND THE TAKE-HOME MESSAGE IS, NO MATTER WHAT BRAND OF SCANNER YOU HAVE, THERE'S A HUGE AMOUNT OF VARIABILITY USED WORLDWIDE ON HOW MUCH RADIATION IS BEING USED. JUST HERE, IT SAYS A FOUR FOLD DIFFERENCE IN THE AMOUNTS OF RADIATION. THE NIH IS OBVIOUSLY INTERESTED IN THE AMOUNT OF RADIATION. THEY HELD A SUMMIT THAT PARTICIPATED, AND THEY THREW THE QUANTITY LET GAUNTLET DOWN, THEY SAID ALL CT EXAMS SHOULD BE LESS THAN 1. IT'S NOT JUST ABOUT THE SCANNER, IT'S ABOUT A TEAM EFFORT, IT'S THE COLLABORATION BETWEEN THE REFERRING DOCTOR, THE IMAGERS, THE NURSES, THE TECHNOLOGISTS AND IMAGING PHYSICISTS. THE GOAL IS TO DO THE RIGHT SCAN ON THE RIGHT PATIENT FOR THE RIGHT AMOUNT OF DOSE. SO THIS IS THE IMAGING VERSION OF PERSONALIZED MEDICINE. YOU COULD REDUCE RISK BY NOT DOING A SCAN. THERE IS GUIDELINES, THERE'S -- BOTH BY THE CARDIOLOGY COMMUNITY AND ALSO RADIOLOGY COMMUNITY, AND BASICALLY THERE ARE DIFFERENT CLINICAL SCENARIOS AND THEY'LL LIST POTENTIAL IMAGING MODALITIES THAT COULD ANSWER THAT CLINICAL QUESTION. ON THE TECHNICAL SCAN POINT, THERE ARE A MYRIAD OF DIFFERENT POSSIBILITIES THAT ALTER THE ULTIMATE CT IMAGE. THIS IS A SPLEX SLIDE BUT THE THREE FACTORS THAT REALLY MAKE THE BIGGEST IMPORTANCE IS DECREASING EXPOSURE TIME, DECREASING THE NUMBER OF PHOTONS THAT GO THROUGH THE PATIENT AND WHATEVER INFORMATION YOU HAVE, MORE EFFICIENTLY USE THAT INFORMATION. SO IN TERMS OF HOW MUCH TIME WE IMAGE THE PATIENT, THIS IS HOW WE USUALLY DO CARDIAC CT. WE USED TO TURN ON THE X-RAY OVER SEVERAL HEART BEATS AND WE GOT THESE BEAUTIFUL IMAGES OF A BEATING HEART. HOWEVER, IN ACTUALITY, MOST OF THE TIME WE'RE INTERESTED IN THE CORONARY VESSELS, AND WE CAN JUST LOOK AT ONE PHASE OF THE CARDIAC CYCLE, AND THAT WAY WE'RE ABLE TO REDUCE THE AMOUNT OF TIME THAT WE ACTUALLY NEED TO IMAGE THE PATIENT. ONE EXTREME FORM IS WHAT NHLBI INVESTED IN, IS TO HAVE THESE WIDE AREA DETECTORS AND WE'RE ACTUALLY ABLE TO IMAGE THE WHOLE HEART WITHIN ONE HEARTBEAT. AND THAT GIVES YOU SOME ADVANTAGES BECAUSE IF YOU HAVE A REALLY WIDE ANGLE CAMERA, IF YOU'RE AT THE GRAND CANYON AND YOU WANT TO TAKE A NICE PANORAMIC PICTURE, YOU MIGHT TAKE A PICTURE AND KIND OF STITCH IT TOGETHER. THE SAME THING HAPPENS WITH MED WILL MEDICAL IMAGING, YOU GET THESE STITCH ARTIFACTS BETWEEN DIFFERENT SLABS OF DATA THAT MAKES THE INTERPRETATION HARD. BUT IF YOU HAVE A WIDE AREA CAME CAMERA, YOU'RE ABLE TO CAPTURE EVERYTHING AT ONE TIME AND MAKES INTERPRETATION EASIER. THE OTHER WAY TO REDUCE RADIATION IS DECREASE THE NUMBER OF PHOTONS GOING THROUGH THE PATIENT. NOW WE USED TO USE THESE BMI TABLES, THE PATIENT COMES IN, YOU LOOK AT THEIR HEIGHT AND WEIGHT AND YOU DETERMINE HOW MUCH RADIATION THEY NEEDED. HOWEVER, THAT'S PRETTY INACCURATE. HERE'S ONE EXTREME EXAMPLE. THIS IS THE WORLD'S TALLEST MAN, THE WORLD'S SHORTEST MAN. THEY'RE ABOUT THE SAME BMI BUT OBVIOUSLY THE WORLD'S SMALLEST MAN NEEDS LESS RADIATION TO SUCCESSFULLY IMAGE HIM. THE WAY WE ACCOMPLISH THIS NOW IS THAT SCANNERS HAVE AUTOMATIC EXPOSURE CONTROL, FROM A SCOUT IMAGE, IT LOOKS AT HOW MUCH ATTENUATION THERE IS, OBVIOUSLY IN THE CHEST WHERE IT'S MAINLY AIR, LESS RADIATION IS NEEDED. HOWEVER WHEN YOU HIT THE ABDOMEN, THERE'S MORE SOFT TISSUE AND THE SCANNER WILL AUTOMATICALLY INCREASE THE RADIATION NEEDED TO IMAGE THAT PART OF THE BODY. THE LAST TENET IS TO EFFICIENTLY USE EXPOSURE INFORMATION. TRADITIONAL K CT IMAGING BEGAN IN THE 1960s WHERE THEY USED A LOT OF SHORTCUTS. MODERN COMPUTING POWER, WE'RE NOW MORE ABLE TO EFFICIENTLY USE THE INFORMATION. BASICALLY THERE'S -- IN THE BACKGROUND, THROUGH MULTIPLE ITERATIONS, WE'RE ABLE TO TAKE AN ORIGINAL IMAGE AND, OVER TIME, IMPROVE THE IMAGE QUALITY. NOW, THIS IS COMPLICATED BECAUSE FOR EVERY PIXEL THAT WE SEE ON THE IKAGE, A STANDARD IMAGE IS 512 BY 512, THERE'S MULTIPLE INTERACTIONS IN THE SAME X-Y PLANE BUT ALSO THE SEIZE PLANE, SO EACH PIXEL HAS 26 NEIGHBORS. BUT THE GOOD THING IS THAT COMPUTING POWER IS GETTING FASTER AND FASTER. EVERY YEAR, APPLE OR SAMSUNG COMES OUT WITH A NEW SMART PHONE, THEY TELL YOU HOW MUCH FASTER IT IS FROM THE PRIOR MODEL. TO PUT THAT IN PERSPECTIVE, GORDON BORE WAS THE FOUNDER OF INTEL IN THE 60s, SAID THAT COMPUTING POWER WOULD DOUBLE EVERY TWO YEARS. IF YOU WERE TO FLY FROM HERE TO LONDON 40 YEARS AGO, IT WOULD HAVE COST $1,000 AND TAKEN ABOUT SEVEN HOURS. NOW IF YOU CUT THAT IN HALF, EVERY TWO YEARS, THAT SAME PLANE FLIGHT WOULD COST LESS THAN A PENNY, AND WILL TAKE LESS THAN A SECOND. AND THE SAME THING HAS HAPPENED IN TERMS OF COMPUTING POWER. SO IN TERMS OF COMPUTING FOR GRAPHICS, FLOATING POINT OF OPERATIONS PER SECOND, SO AN EXAMPLE IS, WHAT IS 7 TIMES 7? YOU WOULD SAY IT'S 49, RIGHT? IT MIGHT TAKE YOU MAYBE A SECOND OR HALF A SECOND TO FIGURE THAT OUT. SO THESE PROCESSORS DO -- ONE OF THEM CAN DO 5.2 TRILLION OPERATIONS PER SECOND, AND THAT'S JUST ONE. THESE ARE USED TO RENDER PIXAR MOVIES, LIKE TOY STORY OR MONITORS, INGE, BUT FOR THESE CONSTRUCTION UNITS, WE ACTUALLY HAVE EIGHT OF THESE GRAPHICS BOARDS WORKING TOGETHER TO PRODUCE IMAGES. SO WE'VE EVALUATED EARLY VERSIONS OF THIS, WE WERE ABLE TO REDUCE RADIATION BY 50%. WE REDUCE THE RADIATION BY 50% AND IMAGES ARE GRAINIER, A LITTLE BIT MORE DIFFICULT TO INTERPRET, BUT THEN IF WE ADD ON THIS NEW AGE RECONSTRUCTION, WE'RE ACTUALLY ABLE TO BUY BACK THE RESOLUTION. IF YOU QUANTITATIVELY LOOK AT IT WHERE IMAGE QUALITY SCORE OF 4 IS OF BEST AND 1 IS NOT EVEN DIAGNOSTIC, WE REDUCED RADIATION BY 50%, THE IMAGE QUALITY GOES DOWN, BUT THEN WHEN WE ADD THESE NEW IMAGE RECONSTRUCTION METHODS, THE IMAGE QUALITY IS ACTUALLY THE SAME OR ACTUALLY BETTER THAN THE ORIGINAL IMAGE. SO IF YOU PUT ALL THESE THINGS TOGETHER, I SHOWED YOU THE SLIDE EARLIER, WHERE DOES NHLBI SIT? NHLBI SITS DOWN HERE, SO WE USE VERY LOW AMOUNTS OF RADIATION AND WE CONSISTLY GET IT VERY LOW. WE'VE LOOKED OVERIN THE PAST SEVERAL YEARS THE LAST 3,000 STUDIES, SO THIS IS RADIATION DOSE OVER TIME, THE RADIATION DOSE HAS BEEN GOING TOWN, AND THIS IS DESPITE THE PATIENT BODY SIZE REMAINING THE SAME. WE CAN DO ULTRA, ULTRA LOW DOSE CARDIAC IMAGING. THIS IS FOR A RATE YAITION DOSE EQUIVALENT OF A CHEST X-RAY. IT'S ALSO IMPORTANT TO REALIZE THAT WE CAN REDUCE THE RADIATION BUT YOU DON'T WANT TO LOSE THE DIAGNOSTIC ACCURACY. SO THIS IS A PATIENT WITH A NON-OBSTRUCTIVE DISEASE IN THE LEFT ANTERIOR DESCENDING AND A HIGH GRADE STENOSIS IN THE CIRCUMFLEX. WHEN THIS PATIENT WENT TO INVASIVE CATHETERIZATION, THERE'S STILL A HIGH CORRELATION OF WHAT WE XENON SEE NON-INVASIVELY WITH CT COMPARED TO THE GOLD STANDARD OF THE CATH LAB. WE CAN ALSO LOOK AT CARDIAC FUNCTION, WE HAVE A COLLABORATION WITH CHILDREN'S HOSPITAL WHERE THEY SEND PATIENTS WHO HAVE DEVICES, PACEMAKERS, ICDs WHO TRADITIONALLY CANNOT HAVE AN M RI. SCAN, SO THEY HAVE AN ULTRA LOW DOSE CT TO ASSESS THEIR CARDIAC FUNCTION. TO GIVE YOU AN IDEA, THIS IS ONE FOR EQUIVALENT LEVEL OF .3 MSV. A TRADITIONAL SCAN DONE IN COMMUNITY, THIS IS A SCAN I REVIEWED A COUPLE WEEKS AGO, FROM THE OUTSIDE CENTER, THIS IS ALSO DONE TO EVALUATE FOR CARDIAC FUNCTION. HOWEVER, THIS DOSE IS 100 TIMES MORE THAN WHAT WE CAN ACHIEVE HERE AT NIH. WE CAN ALSO APPLY THIS TO CORONARY CALCIUM SCORING, CURRENTLY IT'S A NON-CONTRAST TECHNIQUE TO ASSESSOR ACTUALLY CAN BE USED TO SCREEN FOR CORONARY ARTERY DISEASE, IT CAN PREDICT FUTURE EVENTS TO HIGHER YOUR CALCIUM BURDEN, TO HIGHER -- INFARCT IN THE FUTURE AND WE'VE BEEN ABLE TO USE THESE CONSTRUCTION TECHNIQUES TO REDUCE THE AMOUNT OF RADIATION BY 70% FOR A SCREENING EXAM. WHEN YOU GO TO A STORE AND BUY SOMETHING ON SALE, I THINK YOU'RE HAPPY IF YOU GET SOMETHING 20% OFF. WE'RE TALKING 70% OFF IN TERMS OF AMOUNT OF RADIATION THAT WE'RE ABLE TO DELIVER. NOW I TALKED ABOUT CARDIAC. NOW, UNFORTUNATELY, WORLD WAD CARDIAC EXAMS ONLY REPRESENT 2% OF ALL CT IMAGING. I'M IN THE HEART LUNG AND BLOOD INS INSTITUTE, MY COLLEAGUES ARE PULMONOLOGISTS SO WE'VE BEEN BRANCHING OUT INTO THE HEART FROM THE LUNGS. ONE SCAN HERE IS A STANDARD CHEST CT AND ONE IS AN ULTRA LOW DOSE CHEST CT. CAN YOU TELL THE DIFFERENCE BETWEEN THE TWO? LARGE CYSTIC DISEASE HERE. SO LET ME JUST POLL THE AUDIENCE REAL QUICKLY. WHO THINKS THIS IMAGE ON YOUR LEFT IS RESEARCH ULTRA LOW DOSE IMAGE? HOW ABOUT ON THE RIGHT? WHO CAN'T TELL? WELL, THE ONE ON THE RIGHT IS A RESEARCH ULTRA LOW DOSE, BUT THIS WAS DONE FOR 92% LESS RADIATION. NOW WE ARE ABLE TO -- AS SOME OF YOU IN THE AUDIENCE ARE PRETTY SHARP, WE WILL USE A COMPUTER TO QUANTITATE, TO BE A MODEL READER AND MEASURE HOW BIG -- WHAT IS THE DISEASE BURDEN INVOLVING THE LUNGS IN THESE PATIENTS. THAT'S IMPORTANT BECAUSE IT'S ONE WAY TO MOB TORE DISEASE MONITOR DISEAS E AND THERE IS ONE THERAPY AND DEPENDING ON HOW PROGRESSIVE THE DISEASE IS, YOU MIGHT ADJUST HOW MUCH MEDICATION YOU'RE ON. NOW, WE JUST COMPLETED A STUDY OF NEARLY 200 PATIENTS WHERE THEY GOT THE STANDARD CHEST C T AND THEN THEY ALSO HAD A RESEARCH ULTRA LOW DOSE CT SCAN. 195 PATIENTS, PREDOMINANTLY FEMALE, NORMAL SIZE PEOPLE, BMI WAS 27, THIS IS WHAT WE FOUND. SO WHEN WE HAD COMPUTER AUTOMATICALLY QUANTIFY HOW MUCH DISEASE THEY HAVE, THERE'S A NEAR PERFECT CORRELATION BETWEEN THE STANDARD DOSE SCAN AND ULTRA LOW DOSE SCAN, AND THE DIFFERENCE BETWEEN THE TWO WITH WAS LESS THAN 1% . THIS JUST SHOWS THE RADIATION DOSE OVER TIME. WE DID HAVE A SCANNER CHANGE AT THIS POINT HERE AND FOR THE LAST 73 CONSECUTIVE PATIENTS ON OUR CURRENT PLATFORM, THE RADIATION DOSE WE WERE ABLE TO DELIVER FOR THESE PATIENTS IS .14 MSV AND THAT'S EQUIVALENT TO ONE CHEST X-RAY, BUT WE'RE GETTING A FULLY DIAGNOSTIC CHEST CT OUT OF IT. A STANDARD CHEST CT IS ABOUT 5 TO 7 MSV OF RADIATION. YOU MAY HEARD OF LOW DOSE CANCER SCREENING PROTOCOLS, THAT'S ABOUT 1 1/2 TO 2 MSV OF RADIATION. CHEST X-RAY IS ABOUT .11 AND .15, SO THE CURRENT NIH STANDARD CHEST CT IS LOWER THAN THE NATIONAL AVERAGE, AND THAT'S ABOUT 3.3 MSV. HOWEVER, THESE ULTRA LOW DOSE CTs ARE NOW EQUIVALENT TO A CHESS EXRAI. CHEST X-RAY. WE HAVE A LUNG PHANTOM, WHICH IS A PLASTIC PERSON, WE PUT SOME LUNG NODULES IN IT. SO HERE'S A STANDARD DOSE CT, YOU WE PUT THESE LUNG NODULES IN THE APICES, VERY HARD TO INDIVIDUALIZE. IF YOU DO AN ULTRA LOW DOUSE CT SCAN USING STANDARD CON STRUCK, THESE NODULES ARE NOW HARD TO VISUALIZE OR DETECT. BUT IF WE USE THESE NEW IMAGE RECONSTRUCTION METHODS, WE NOW BUY BACK THE RESOLUTION AND BE ABLE TO USE THESE REALLY LOW DOSES. HERE'S JUST A BLOW-UP OF THE APEX THERE. YOU'RE NOT ABLE TO SEE WITH TRADITIONAL IMAGING BUT NOW YOU BUY BACK THE RESOLUTION. SO IN THE FUTURE, I THINK WE'LL BE ABLE TO ACTUALLY REPLACE A CHEST X-RAY AND JUST ACTUALLY DO ULTRA LOW DOSE SCAN. SO HERE'S A PATIENT WITH EARLY LUNG CANCER, THERE'S A 4-MILLIMETER NODULE HERE. THIS IS WHAT IT LOOKS LIKE WITH TRADITIONAL IMAGE RECONSTRUCTION, ULTRA LOW DOSE TECHNIQUES, WE'RE NOW ABLE TO BUY BACK THE RESOLUTION TO DETECT THE CANCER. SO OVERALL, THERE HAVE BEEN THESE TECHNOLOGICAL ADVANCES THAT HAVE DRAMATICALLY REDUCED THE AMOUNT OF RADIATION. WE'VE BEEN ABLE TO DO THIS FOR CARDIAC FOR A COUPLE YEARS NOW, THE AND THE LESSONS LEARNED FROM CARDIAC, WE'RE NOW APPLYING TO OTHER BODY PARTS IN AND THE FIRST TARGET IS THE LUNG. I'D LIKE TO ACKNOWLEDGE ALL MY COLLABORATORS AND COLLEAGUES. THANK YOU VERY MUCH FOR YOUR ATTENTION. [APPLAUSE] >> SO WE HAVE SOME TIME FOR QUESTIONS. CAN YOU PLEASE, IF YOU HAVE THEM, GO AND USE THE MICROPHONES IN THE AISLES? >> CONGRATULATIONS FOR REDUCING THE RADIATION DOSE! SO HOW MANY OF THESE -- WE HAVE THE BEST RESEARCH CENTERS IN THE WORLD WITH ALL THE LATEST TECHNOLOGY AND EVERYTHING ELSE. SO HOW WILL THE OTHER HOSPITALS CHANGING TO THIS LOW DOSE ENVIRONMENT? AT THE HIGH LEVEL ACADEMIC CLINICAL CENTERS VERSUS COMMUNITY LEVEL HOSPITAL? >> RIGHT, SO THAT'S A GREAT QUESTION. HOW MANY OTHER SITES ARE ABLE TO REDUCE IT LIKE THIS. AND IT IS A CHAL CHALLENGE. SO YOU DO NEED TO HAVE THE HIGH END EQUIPMENT. I'VE BEEN WORKING WITH THE MANUFACTURERS TO TRY TO IMPLEMENT THIS AT OTHER SITES, AND BASICALLY WHAT IT COMES DOWN TO IS COMPUTING POWER. SO THEY NEED TO ADD ON THESE HIGH END COMPUTERS TO RECONSTRUCT THE IMAGES. AND THERE'S A COST FOR THAT. SO COMMUNITY HOSPITALS CAN BUY THE EQUIPMENT, BUT THE THING THAT MAKES THE MOST SENSE IS TO INCORPORATE IT INTO A NEW SYSTEM. SO WHEN THEY BUY A NEW CT SCANNER, IT'S NOW INCLUDED. SO THE ANALOGY OF THIS WOULD BE A BACKUP CAMERA FOR YOUR CAR. THEY'RE GREAT, RIGHT? YOU DON'T TURN YOUR HEAD AROUND, YOU CAN SEE WHAT'S BEHIND YOU. TO RETROFIT YOUR CAR THAT DOESN'T HAVE A BACKUP CAMERA, IT'S GOING TO COST A LOT. BUT THE INCREMENTAL COST TO INSTALL IT ON A BRAND NEW CAR, IT DOESN'T COST VERY MUCH. SO THE MANUFACTURERS ARE NOW INCORPORATING THIS TYPE OF TECHNOLOGY INTO NEW SYSTEM-MAKING STANDARD WHEN THEY SELL IT. NOW THE DOWNSIDE IS THAT YOU HAVE TO WAIT UNTIL A HOSPITAL UPGRADES THEIR EQUIPMENT, BUT EVENTUALLY, THE LIFE CYCLE OF A CT SCANNER IS PROBABLY ABOUT 10 YEARS. EVENTUALLY, THIS TECHNOLOGY WILL THEN BECOME WIDESPREAD THROUGHOUT THE COMMUNITY. >> BASICALLY CT IS BASED ON DENSITY, TISSUE DENSITY, CALCIFICATION OR OTHER PATHOLOGY. SO IN THE CORONARY ARTERIES FOR CALCIUM SCORE, YOU MENTIONED THAT THEY'RE EQUALLY EFFECTIVE AT THE LOW DOSE, BUT WHAT ABOUT OTHER TYPES OF PATHOLOGIES THAT MIGHT BE PRESENT IN CANCER, CYST AND OTHER TYPES OF TISSUE PATHOLOGIES, ARE THEY ALSO GETTING SIMILAR BENEFITS FOR DIAGNOSIS? >> YEAH, AND THAT'S ONE THING WE'RE WORKING ON. ESPECIALLY FOR THE LUNG. SO WHAT WE CAN DO, LUK NODULE LUNG NODULES , CYSTS, BUT ALSO INTERESTED TO SEE IF WE CAN DETECT OTHER THINGS, OTHER ABNORMALITIES AS WELL. BUT I THINK THAT THESE TECHNIQUES ACTUALLY WILL WORK. I'VE SEEN IMAGES AND I'M PRETTY CONFIDENT THAT WE CAN REALLY DIAL DOWN THE DOSE AND MAKE THE TEST SAFER FOR PEOPLE. >> THANK YOU. >> TIFFANY, I WANTED TO ASK UH-UH IN YOUR YOU IN YOUR MODEL, YOU FOCUSED ON ONE ENVIRONMENTAL FACTOR WHICH WOULD BE SAFETY IN TERMS OF REDUCING OBESITY. BUT WHAT ABOUT OTHER PRESSING SOCIOECONOMIC FACTORS LIKE THE LIMITATION OF THE NUMBER OF GROCERY STORES THAT ARE AVAILABLE IN THE WASHINGTON, D.C. AREAS THAT YOU'RE STUDYING, HOW WOULD YOU FACTOR THOSE IN, WHAT ELSE CAN YOU DO, BECAUSE THE DRIVER THERE SEEMS TO BE ECONOMIC AND NOT NECESSARILY A DECISION BASED ON THE COMMUNITY. >> SO THAT'S A GREAT QUESTION. ONE THING THAT WE ARE LOOKING TO DO WITH THE GROUP AT HOPKINS WITH THE GLOBAL OBESITY PREVENTION CENTER IS ACTUALLY THINK MORE ABOUT MODELS THAT INCORPORATE FOOD ENVIRONMENT AS WAYS -- AND SO SPECIFICALLY ACCESS TO GROCERY STORES, CONVENIENCE STORES, MARKETS FOR HEALTHY FOODS, AND LOOK AT HOW -- AT LEAST HOW THE FOOD ENVIRONMENT THAT EXISTS RIGHT NOW, HOW THAT INFLUENCES OBESITY BUT ALSO HOW POTENTIAL CHANGES IN THE FOOD ENVIRONMENT MAY INFLUENCE OBESITY. THEIR GROUP ACTUALLY HAS QUITE A BIT OF EXPERIENCE IN THINKING ABOUT FOOD ENVIRONMENT AS IT RELATES TO CHILDHOOD OBESITY. JOEL GIDDLESON AT HOPKINS HAS DONE A LOT OF WORK IN THINKING ABOUT INTERVENTIONS, MULTILEVEL INTERVENTIONS THAT NOT ONLY TARGET EDUCATION AROUND IMPROVING DIETARY INTAKE, BUT ALSO THINKING ABOUT COMMUNITY-BASED INTERVENTIONS THAT TARGET GROCERY STORES TO IMPROVE ACCESS TO HEALTHY FOODS, AND SO HE'S USED THE MODELING THROUGH THE GLOBAL OBESITY PREVENTION CENTER IN THE DESIGN OF INTERVENTIONS FOR BALTIMORE. >> OKAY. SO IF THERE ARE NO MORE QUESTIONS, WE WANT TO THANK YOU FOR COMING. NEXT WEEK WE WILL HAVE A SPECIAL PRESENTATION, WE'RE GOING TO CONTINUE ON THE THEME OF OBESITY. WE WILL ADDRESS SURGICAL INTERVENTIONS FOR THE TREATMENT OF OBESITY, AND WE WILL HAVE A SPECIAL PRESENTATION FROM OUR COLLEAGUE AT JOHNS HOPKINS, DR. CLIFF WEISS. THANKS. SEE YOU NEXT WEEK. [APPLAUSE]