[Lung activity in 201Tl myocardial scintigraphy: distribution and correlation with hemodynamic parameters]

Area of Science:

• Nuclear Cardiology
• Cardiovascular Imaging
• Pulmonary Function Assessment

Background:

• Myocardial scintigraphy using thallium-201 (201Tl) is a standard imaging technique.
• Pulmonary activity in 201Tl myocardial scintigraphy can reflect left ventricular function.
• Accurate quantification of pulmonary thallium uptake is crucial for reliable interpretation.

Purpose of the Study:

• To validate the accurate quantification of pulmonary 201Tl activity from anterior SPECT projections.
• To describe the intrapulmonary distribution pattern of thallium.
• To evaluate the impact of left ventricular function parameters on the lung/heart ratio (LHR).

Main Methods:

• Analysis of scintigraphic images from 85 patients undergoing 201Tl myocardial scintigraphy.
• Inclusion of planar anterior thoracic imaging in 24 patients.
• Performance of radionuclide ventriculography in 41 patients within 4 weeks post-scintigraphy.

Main Results:

• Pulmonary 201Tl content was accurately quantifiable from anterior SPECT projections.
• A gradient of lower thallium activity was observed in the apical compared to the basal lung regions.
• Left ventricular ejection fraction (LVEF) during exercise and heart rate during exercise (HRex) were significantly related to LHR.

Conclusions:

• Pulmonary 201Tl uptake can be reliably quantified using anterior SPECT.
• The apical-basal gradient in lung thallium distribution is a notable finding.
• An elevated LHR, after adjusting for HRex, indicates pathological exercise-induced LVEF.