A novel quantitative dual-isotope method for simultaneous ventilation and perfusion lung SPET

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Pulmonary Physiology

Background:

• Accurate assessment of lung ventilation (V) and perfusion (Q) is crucial for diagnosing and managing pulmonary diseases.
• Quantitative imaging techniques are needed to precisely evaluate V/Q distributions.
• Existing methods may have limitations in accuracy and quantitative assessment.

Purpose of the Study:

• To present, validate, and clinically test a quantitative dual-isotope single-photon emission tomography (SPET) technique for assessing lung V and Q.
• To implement and evaluate algorithms for scatter, attenuation, and partial volume correction.
• To assess the V/Q distribution in quantitative terms using the developed SPET method.

Main Methods:

• A dual-isotope SPET technique using technetium-99m labelled Technegas for ventilation and indium-113m labelled macro-aggregated albumin for perfusion.
• Implementation of quantitative algorithms for scatter, down-scatter, attenuation correction, and organ outlining.
• Validation using a phantom system and clinical testing in a healthy volunteer, employing a three-headed SPET system.

Main Results:

• Experimental validation showed minimal mean differences between corrected and uncorrected phantom data (1.9% for 99mTc, 0.9% for 113mIn).
• The estimated V/Q distribution in a 3D lung phantom peaked at V/Q=1 with a FWHM of 0.31.
• In a healthy volunteer, the V/Q distribution peak was 0.9 with a FWHM of 0.35.

Conclusions:

• The developed quantitative dual-isotope SPET method allows for accurate regional assessment of radionuclide distribution in the lungs.
• The technique enables precise quantification of ventilation, perfusion, and their distributions, offering valuable insights into lung physiology.
• This method holds significant potential for both basic lung physiology research and clinical practice.