[Xenon-133 rCBF SPECT by newly designed bolus inhalation method]

Area of Science:

• Nuclear Medicine
• Radiology
• Neuroimaging

Background:

• Single photon emission computed tomography (SPECT) with 133Xe gas inhalation allows quantitative regional cerebral blood flow (rCBF) measurement.
• Current 133Xe SPECT methods often yield lower image quality compared to SPECT using 99mTc-HMPAO or 123I-IMP.

Purpose of the Study:

• To develop and assess a novel bolus inhalation method for 133Xe gas SPECT.
• To improve the efficiency of 133Xe gas administration and enhance SPECT image quality for rCBF quantification.

Main Methods:

• A bolus inhalation technique was designed, involving synchronous administration of 133Xe gas during inspiration via a mouthpiece.
• The bolus administration was followed by steady breathing of 133Xe gas within a closed-circuit system with a spiro-bag.
• The method utilized a standard dose of 1,850 MBq of 133Xe gas.

Main Results:

• The bolus inhalation method achieved an approximately twofold increase in the head count ratio compared to conventional inhalation methods.
• This significant increase in signal intensity led to a considerable improvement in the quality of rCBF images.
• Optimization of the SPECT reconstruction filter further enhanced image quality.

Conclusions:

• The novel bolus inhalation method is clinically feasible and effective for improving 133Xe SPECT imaging.
• This technique offers enhanced image quality for quantitative rCBF assessment, potentially surpassing existing methods.
• The improved rCBF imaging may lead to more accurate diagnosis and monitoring of cerebrovascular conditions.