# Simultaneous perfusion and dopaminergic imaging using dual-isotope CZT SPECT/CT in dementia with Lewy bodies

## TL;DR

A new imaging technique using CZT SPECT/CT can simultaneously assess dopamine and blood flow in dementia with Lewy bodies, improving diagnostic accuracy.

## Contribution

The study demonstrates the use of dual-isotope CZT SPECT/CT for simultaneous dopamine transporter and perfusion imaging in DLB, enhancing diagnostic evaluation.

## Key findings

- Reduced dopamine transporter uptake was observed in 84% of DLB patients.
- Cerebral hypoperfusion was found in all DLB patients.
- Patients with normal dopamine transporter imaging still showed perfusion abnormalities.

## Abstract

Current diagnostic criteria for dementia with Lewy bodies (DLB) include indicative and supportive biomarkers, some of which are typically assessed separately using dopamine transporter or perfusion imaging. Cadmium-zinc-telluride (CZT) Single Photon Emission Computed Tomography (SPECT) cameras improve simultaneous dual isotope acquisition using [99mTc]-hexamethylpropyleneamine oxime ([99mTc]TcHMPAO) (perfusion) and N-(3-Fluoropropyl)-2β-carbomethoxy-3β-(4-[123I]iodophenyl)nortropane ([123I]FP-CIT; dopamine transporter), allowing the assessment of one indicative and two supportive biomarkers in a single session. This study aimed to describe the results of dual-isotope brain SPECT imaging in a cohort of patients clinically diagnosed with DLB and to compare clinical characteristics, cognition, structural atrophy, and Alzheimer’s disease (AD) biomarkers, between imaging outcomes.

This retrospective single-center study included a total of 56 consecutive patients (mean ± standard deviation age 80.4 ± 7.8 years; 34% females) referred from an expert memory center finally diagnosed as DLB and who underwent a dual-isotope brain SPECT. Based on core clinical features from Mc Keith et al. revised diagnostic criteria, 40 patients (71%) were classified as probable DLB and 16 (29%) as possible DLB. Reduced dopamine transporter uptake (indicative biomarker) was observed in 84% of patients, while cerebral hypoperfusion was found in 100%. Supportive biomarkers such as cingulate island sign and occipital hypoperfusion were present in 29% and 55%, respectively. All 9 patients with normal dopamine transporter imaging had cerebral hypoperfusion and 3 of them presented supportive biomarkers of DLB. No significant association was found between imaging biomarker results and global cognition score, each core clinical features individually, medial temporal lobe atrophy, or CSF biomarkers for AD.

Dual-isotope brain SPECT using CZT frequently identifies dopamine transporter abnormalities in patients with DLB, always in conjunction with perfusion abnormalities. Patients with normal dopamine transporter imaging always present perfusion abnormalities. This imaging approach provides a more comprehensive assessment of indicative and supportive biomarkers in DLB, without increasing scan duration, potentially enhancing diagnostic confidence in clinical practice, particularly in challenging cases.

The online version contains supplementary material available at 10.1186/s13550-026-01386-z.