Arterial input function measurements using radiotracer and microbubbles: Preliminary results

Antonello E. Spinelli, Robert J. Ott, Gail R. Ter Haar

Research output: Contribution to journalArticlepeer-review


The main objective of this study is to investigate the possible use of the Doppler signal from microbubbles (Levovist) to measure the arterial input function in dynamic positron emission tomography (PET). We have measured the dynamics in a fluid (water or plasma equivalent) of radioactive tracers and microbubbles contrast agents (MB) experimentally. The experimental system allows us to simulate the dispersion of these tracers in large arteries, and, using an appropriate phantom, the dispersion in the heart and lungs. Time-activity curves for Tc-99m were obtained using an NaI(TI) probe connected to a multiscaler system. A Doppler probe was used to measure scattering from the microbubble. The data were processed using MATLAB. The measurement with the radioactive tracer shows a reasonable agreement with theoretical models. Noise present in the Doppler signal, probably caused by the pump, has been reduced using a denoising procedure in the wavelet domain based on a Daubechies wavelet function. Differences in tracer kinetics between Tc-99m and MB found in water are significantly reduced in plasma-equivalent fluid. We conclude that the two methods are comparable and that this method might provide a noninvasive way of measuring arterial input functions for PET.

Original languageEnglish
Pages (from-to)803-807
Number of pages5
JournalIEEE Transactions on Nuclear Science
Volume49 I
Issue number3
Publication statusPublished - Jun 2002


  • Arterial input function
  • Microbubbles contrast agent
  • Radiotracer
  • Wavelet analysis

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Nuclear Energy and Engineering


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