IMPLICATIONS FOR FALSE POSITIVE IMPLICATIONS FOR FALSE POSITIVE ROTATIONAL SPECT (RSPECT) ROTATIONAL SPECT (RSPECT)

STUDIES BEING CAUSED BY POST-STUDIES BEING CAUSED BY POST-STRESS CHANGES IN CARDIAC STRESS CHANGES IN CARDIAC

VOLUMEVOLUME

T.P. Bublitz, D.L. Kirch*, J.E. Koss, P.P. SteeleT.P. Bublitz, D.L. Kirch*, J.E. Koss, P.P. SteeleNuclear Cardiology ResearchNuclear Cardiology Research

Western Cardiology Associates, PCWestern Cardiology Associates, PCEnglewood, ColoradoEnglewood, Colorado

PREVIOUS INDICATIONS THAT PREVIOUS INDICATIONS THAT CARDIAC CHAMBER SIZE CHANGES CARDIAC CHAMBER SIZE CHANGES

COULD BE A PROBLEMCOULD BE A PROBLEM

■ Literature describes dramatic shape and volume changes Literature describes dramatic shape and volume changes during and following exercise and change of positionduring and following exercise and change of position

■ Occurrence of unexplainable false positive myocardial Occurrence of unexplainable false positive myocardial perfusion studies (specificity in the 70-80% range)perfusion studies (specificity in the 70-80% range)

■ Numerous attempts to identify and correct for sources of Numerous attempts to identify and correct for sources of artifacts in RSPECT studies have proven inconclusiveartifacts in RSPECT studies have proven inconclusive

■ Visual inspection of cine playback of RSPECT imagesVisual inspection of cine playback of RSPECT images

■ Ability of NRSPECT to monitor cardiac chamber volume Ability of NRSPECT to monitor cardiac chamber volume changes over a 20-30 min period following stresschanges over a 20-30 min period following stress

METHODOLOGY APPLIED TO METHODOLOGY APPLIED TO SEQUENTIALLY MONITOR CARDIAC SEQUENTIALLY MONITOR CARDIAC

VOLUME CHANGESVOLUME CHANGES■ MULTI-PINHOLE NRSPECT IS UNIQUELEY SUITED FOR MULTI-PINHOLE NRSPECT IS UNIQUELEY SUITED FOR

SERIAL MEASUREMENTSSERIAL MEASUREMENTS

■ EXCELLENT STATISTICS PERMIT VOLUME EXCELLENT STATISTICS PERMIT VOLUME COMPUTATIONS TO BE MADE IN THREE MINUTE COMPUTATIONS TO BE MADE IN THREE MINUTE INTERVALSINTERVALS

■ MIDLINE OR CENTER WALL TRACKING USED TO MIDLINE OR CENTER WALL TRACKING USED TO COMPUTE VOLUMES COMPUTE VOLUMES

■ VISUAL INSPECTION USED TO CORROBORATE THE VISUAL INSPECTION USED TO CORROBORATE THE MAGNITUDE AND DIRECTION OF THE COMPUTED MAGNITUDE AND DIRECTION OF THE COMPUTED CHANGESCHANGES

■ CHAMBER SHAPE CHANGES ARE VISUALLY CHAMBER SHAPE CHANGES ARE VISUALLY APPRECIATEDAPPRECIATED

SIMULTANEOUS DUAL-ISOTOPE (TL-201/TC99m) SIMULTANEOUS DUAL-ISOTOPE (TL-201/TC99m) MYOCARDIAL PERFUSION IMAGING PROTOCOLMYOCARDIAL PERFUSION IMAGING PROTOCOL

■ SETUP IV AND INJECT 6.0 mCi OF Tc AGENTSETUP IV AND INJECT 6.0 mCi OF Tc AGENT

■ PATIENT DRINKS 8-16 oz OF CLEAR LIQUID DURING 10 min WAIT PATIENT DRINKS 8-16 oz OF CLEAR LIQUID DURING 10 min WAIT PRIOR TO EKG HOOK-UP FOR STRESS TESTPRIOR TO EKG HOOK-UP FOR STRESS TEST

■ INJECTION OF 4.0 mCi OF Tl-201 OCCURS 1-2 min PRIOR TO INJECTION OF 4.0 mCi OF Tl-201 OCCURS 1-2 min PRIOR TO CESSATION OF STRESS MANEUVRECESSATION OF STRESS MANEUVRE

■ GATED, SIMULTANEOUS DUAL-ISOTOPE IMAGING IS PERFORMED GATED, SIMULTANEOUS DUAL-ISOTOPE IMAGING IS PERFORMED IMMEDIATELY FOLLOWING COOL DOWN IMMEDIATELY FOLLOWING COOL DOWN

■ LIST-MODE DATA ACQUISITION TAKES ABOUT 20 MINUTES AND LIST-MODE DATA ACQUISITION TAKES ABOUT 20 MINUTES AND RESULTS IN 3 MILLION COUNTS PER VIEWRESULTS IN 3 MILLION COUNTS PER VIEW

■ TOTAL DURATION OF TEST IS < 90 minTOTAL DURATION OF TEST IS < 90 min

SHORT AXIS RESTING IMAGES Tc-99m

SHORT AXIS STRESS IMAGES Tl-201

LONG AXIS RESTING IMAGES

LONG AXIS STRESS IMAGES

MULTI-PINHOLE TOMOGRAPHIC RECONSTRUCTIONS

CENTER WALL TRACKING PERFORMED ON 8 SHORT AXIS SLICES FROM APEX TO BASE

CCP CURVES DEVELOPED AT 60 POINTS THROUGH

360o. SEARCH FOR MAXIMUM VALUE AVERAGED

WITH TWO NEAREST RADIAL NEIGHBORS

APEX

BASE

STRESS REST

STRESS-REST DIFFERENCE

CIRCUMFERENTIAL COUNT PROFILE CURVES

STRESS (EARLY) VOLUME IMAGES = 77 cc

MID VOL =73cc

RESTING (LATE) VOLUME IMAGES = 72cc

VOLUME IMAGES UNGATED (TOP) GATED (BOTTOM)

ACUTELY DILATED VOLUME (77 cc TO 72 cc)WITH INFERIOR LATERAL SHAPE CHANGES

ACUTELY DIMINISHED VOLUME (113 cc TO 130 cc)WITH SUPERIOR LATERAL SHAPE CHANGES

NO VOLUME CHANGES (50 cc TO 52 cc)AND NO SIGNIFICANT SHAPE CHANGES

ACUTELY DILATED VOLUME (135 cc TO 126 cc)WITH SUPERIOR SEPTAL SHAPE CHANGES

NEGLIGIBLE VOLUME CHANGES (110 cc TO 111cc)WITH REDISTRIBUTATIVE SIZE CHANGES

ACUTE VOLUME DILATION (102 cc TO 96 cc)WITH INFERIOR SHAPE CHANGES

Cardiac Volumes Post-Exercisen = 818

0

20

40

60

80

100

120

-30.00% -20.00% -10.00% 0.00% 10.00% 20.00% 30.00% 40.00%

% LV Volume Change

CARDIAC POST STRESS VOLUME CHANGES (VC)(N=818)

MEAN VOLUME CHANGE = -4.34%(men = 5.7%, women = 2.5%)

23.3% HAVE VC >+10%3% HAVE VC < -10%

23.1% HAVE VC < 0%

-30.0%

-20.0%

-10.0%

0.0%

10.0%

20.0%

30.0%

10000 15000 20000 25000 30000 35000 40000

Exercise Rate-Pressure Product (RPP)

% L

V V

olu

me

Ch

an

ge

CORRELATION BETWEEN POST STRESS VOLUME CHANGES AND RATE-PRESSURE PRODUCT

-30.0%

-20.0%

-10.0%

0.0%

10.0%

20.0%

30.0%

20 30 40 50 60 70 80 90 100

AGE

% L

V V

olu

me

Ch

an

ge

CORRELATION BETWEEN POST STRESS VOLUME CHANGES AND AGE (MEN AND WOMEN COMBINED)

-30.0%

-20.0%

-10.0%

0.0%

10.0%

20.0%

30.0%

20 30 40 50 60 70 80 90 100

Male (Age)

% L

V V

olu

me

Ch

an

ge

CORRELATION BETWEEN POST STRESS VOLUME CHANGES AND AGE (MEN ONLY)

-30.0%

-20.0%

-10.0%

0.0%

10.0%

20.0%

30.0%

20 30 40 50 60 70 80 90 100

Female (Age)

% L

V V

olu

me

Ch

an

ge

CORRELATION BETWEEN POST STRESS VOLUME CHANGES AND AGE (WOMEN ONLY)

-30.0%

-20.0%

-10.0%

0.0%

10.0%

20.0%

30.0%

15 20 25 30 35 40 45

Body Mass Index (BMI)

% L

V V

olu

me

Ch

an

ge

OBESE

CORRELATION BETWEEN POST STRESS VOLUME CHANGES AND BODY MASS INDEX

CONCLUSIONS FROM ANALYSIS OF 818 DUAL-ISOTOPE GATED PERFUSION STUDIES

■ THE MEAN VALUE OF LV VOLUME CHANGES IS +4.5%THE MEAN VALUE OF LV VOLUME CHANGES IS +4.5%

■ MAJORITY OF PATIENTS (70%) SHOW ACUTE DILATION FOLLOWING MAJORITY OF PATIENTS (70%) SHOW ACUTE DILATION FOLLOWING EXERCISE AND RECLINE FOR IMAGINGEXERCISE AND RECLINE FOR IMAGING

■ 23.3% OF PATIENTS SHOW DILATION GREATER THE +10%23.3% OF PATIENTS SHOW DILATION GREATER THE +10%

■ 3% OF PATIENTS SHOW DIMINATION GREATER THAN -10%3% OF PATIENTS SHOW DIMINATION GREATER THAN -10%

■ IN 13% OF PATIENTS SHOWING VOLUME CHANGES >10% IN 13% OF PATIENTS SHOWING VOLUME CHANGES >10% RESOLUTION TO LESS THAN 5% OCCURS BY THE 10 min MID-POINTRESOLUTION TO LESS THAN 5% OCCURS BY THE 10 min MID-POINT

■ SIGNIFICANT VENTRICULAR SHAPE CHANGES CAN OCCUR WITH SIGNIFICANT VENTRICULAR SHAPE CHANGES CAN OCCUR WITH LITTLE CHANGE IN THE COMPUTED VOLUME OF THE VENTRICLELITTLE CHANGE IN THE COMPUTED VOLUME OF THE VENTRICLE

■ WE HAVE NOT FOUND ANY PRE- OR POST-TEST CORRELATE THAT WE HAVE NOT FOUND ANY PRE- OR POST-TEST CORRELATE THAT PREDICTS THE MAGNITUDE OF THESE CHANGESPREDICTS THE MAGNITUDE OF THESE CHANGES

■ SEQUENTIAL STUDIES ON THE SAME PATIENT ARE UNPREDICTABLESEQUENTIAL STUDIES ON THE SAME PATIENT ARE UNPREDICTABLE

Study ComparisonStudy Comparison Test 1 Test 2 Test 3

4.29% 13.48% 14.04%

-8.96% 0.00% -28.30%

3.36% -3.16% 10.98%

-3.33% -3.51% 8.43%

-4.55% 1.39% -7.27%

13.04% -10.26% 0.00%

7.32% 11.30% 5.21%

3.57% 9.90% 8.74%

4.88% -7.69% 3.17%

CINE DISPLAY OF TWO SUCCESSIVE RESTING IMAGES ACQUIRED BACK-TO-BACK

“RESTING” DATA SET “PSEUDO STRESS” DATA SET

CINE DISPLAY OF FRAMES 31 AND 32

“RESTING” STUDY “PSEUDO STRESS” STUDY

These are the transitional frames acquired by detector #1 and detector # 2

IMPLICATIONS OF VOLUME CHANGES AND THEIREFFECTS ON MYOCARDIAL SPECT STUDIES

IMPLICATIONS OF VOLUME CHANGES AND THEIRIMPLICATIONS OF VOLUME CHANGES AND THEIREFFECTS ON MYOCARDIAL SPECT STUDIESEFFECTS ON MYOCARDIAL SPECT STUDIES

■■ CANNOT BE PREDICTED OR COMPLETELY ELIMINATEDCANNOT BE PREDICTED OR COMPLETELY ELIMINATED

■■ MOST PREVELANT SOON AFTER RECLINING PATIENTMOST PREVELANT SOON AFTER RECLINING PATIENT

■■ CAN BE MINIMIZED BY DELAYING ONSET OF IMAGINGCAN BE MINIMIZED BY DELAYING ONSET OF IMAGING

■■ OCCUR IN BOTH STRESS AND REST STUDIESOCCUR IN BOTH STRESS AND REST STUDIES

■■ EFFECTS ARE OBSERVABLE AFTER-THE-FACT IN ROTATIONALEFFECTS ARE OBSERVABLE AFTER-THE-FACT IN ROTATIONALSPECT STUDIES BY VISUAL EVALUATION OF CINE PLAYBACKSPECT STUDIES BY VISUAL EVALUATION OF CINE PLAYBACK

■■ SUGGESTED STATEGY - WAIT TO START AND IMAGE QUICKLY ORSUGGESTED STATEGY - WAIT TO START AND IMAGE QUICKLY OR

■■ IMPLIMENT SIMULTANEOUS RATHER THAN SEQUENTIAL IMAGINGIMPLIMENT SIMULTANEOUS RATHER THAN SEQUENTIAL IMAGING