Dynamic molecular imaging of cardiac innervation using a dual headpinhole SPECT system
Typically 123I-MIBG is used for the study of innervation andfunction of the sympathetic nervous system in heart failure. The protocolinvolves two studies: first a planar or SPECT scan is performed tomeasure initial uptake of the tracer, followed some 3-4 hours later byanother study measuring the wash-out of the tracer from the heart. A fastwash-out is indicative of a compromised heart. In this work, a dual headpinhole SPECT system was used for imaging the distribution and kineticsof 123I-MIBG in the myocardium of spontaneous hypertensive rats (SHR) andnormotensive Wistar Kyoto (WKY) rats. The system geometry was calibratedbased on a nonlinear point projection fitting method using a three-pointsource phantom. The angle variation effect of the parameters was modeledwith a sinusoidal function. A dynamic acquisition was performed byinjecting 123I-MIBG into rats immediately after starting the dataacquisition. The detectors rotated continuously performing a 360o dataacquisition every 90 seconds. We applied the factor analysis (FA)methodand region of interest (ROI) sampling method to obtain time activitycurves (TACs)in the blood pool and myocardium and then appliedtwo-compartment modeling to estimate the kinetic parameters. Since theinitial injection bolus is too fast for obtaining a consistenttomographic data set in the first few minutes of the study, we appliedthe FA method directly to projections during the first rotation. Then thetime active curves for blood and myocardial tissue were obtained from ROIsampling. The method was applied to determine if there were differencesin the kinetics between SHR and WKY rats and requires less time byreplacing the delayed scan at 3-4 hours after injection with a dynamicacquisition over 90 to 120 minutes. The results of a faster washout and asmaller distribution volume of 123IMIBG near the end of life in the SHRmodel of hypertrophic cardiomyopthy may be indicative of a failing heartin late stages of heart failure.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director, Office of Science; National Institutes ofHealth
- DOE Contract Number:
- DE-AC02-05CH11231; NIH:R01EB00121; R01HL50663
- OSTI ID:
- 928712
- Report Number(s):
- LBNL-60008; R&D Project: 0; BnR: YN0100000; TRN: US0803449
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fatty acids and their analogs for myocardial imaging and metabolism
Clinical experience with technetium-99m teboroxime, a neutral, lipophilic myocardial perfusion imaging agent
Related Subjects
60
AUTONOMIC NERVOUS SYSTEM
BLOOD
DATA ACQUISITION
DISTRIBUTION
GEOMETRY
HEART FAILURE
KINETICS
MYOCARDIUM
ROTATION
SAMPLING
SIMULATION
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
WASHOUT
heart failure small animal imaging molecular imagingsympathetic nervous system I-123-MIBG SHR model cardiac hypertrophycompartment modeling factor analysis