Dynamic sequence respiratory gated perfusion pulmonary SPECT without external tracking device.

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiopharmacology

Background:

• Respiratory motion significantly impacts SPECT image quality.
• External tracking devices (ETDs) and list-mode acquisition are traditional methods for respiratory gating.
• There is a need for simpler, more efficient respiratory gating techniques in SPECT.

Purpose of the Study:

• To develop and evaluate a novel respiratory gated pulmonary perfusion SPECT (RGPS) method.
• To achieve respiratory gating using dynamic acquisition without an external tracking device (ETD) or list-mode data.

Main Methods:

• A dynamic sequence technique (50-ms acquisition per view) was employed, analyzing the center of activity (COA) in dynamic frames to identify respiratory phases.
• Phantom studies compared the new RGPS with dynamic sequence acquisition (RGPS-DS) against RGPS with an ETD (RGPS-ETD).
• The RGPS-DS method was applied to SPECT data from three patients undergoing Tc-MAA pulmonary perfusion scans.

Main Results:

• Phantom studies showed good agreement between RGPS-DS and RGPS-ETD, with amplitude measurements being nearly identical.
• The method accurately determined oscillatory motion amplitudes in the phantom study.
• The applicability of RGPS-DS was successfully demonstrated in patient data.

Conclusions:

• The developed method enables RGPS without the need for an ETD.
• RGPS-DS is a feasible, innovative, and potentially efficient technique for respiratory gated pulmonary perfusion SPECT.
• Further validation with larger patient cohorts is recommended to confirm accuracy.