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Updated: Jul 18, 2026
Near-Infrared Spectroscopy During Reactive Hyperemia for the Assessment of Lower Limb Vascular Function
Published on: March 22, 2024
[Hyperemic reactivity scintigraphy in endothelial function]
M Del Val Gómez1, M A San Martín, F G Gallardo
1Servicios de Medicina Nuclear, Hospital Carlos III, Madrid.
Insights
Hyperemic reactivity scintigraphy (HRS) correlates with flow-mediated dilatation (FMD) and can identify perfusion defects in myocardial SPECT scans. HRS may offer additional value in assessing cardiac health.
Area of Science:
- Cardiovascular imaging
- Nuclear cardiology
- Vascular function assessment
Background:
- Endothelial dysfunction is a key factor in cardiovascular disease.
- Assessing endothelial function is crucial for cardiovascular risk stratification.
- Current methods like flow-mediated dilatation (FMD) have limitations.
Purpose of the Study:
- To compare hyperemic reactivity scintigraphy (HRS) with brachial artery FMD.
- To evaluate the relationship between HRS, FMD, and myocardial SPECT findings.
- To determine the clinical utility of HRS in patients undergoing myocardial scintigraphy.
Main Methods:
- 42 patients undergoing myocardial scintigraphy were included; 36 had simultaneous FMD measurements.
- HRS involved dynamic imaging post-Tc-99 sestamibi injection after upper arm occlusion.
- Key HRS indices (MHA/MCA, MxHA/CxHA) were derived from time-activity curves.
Main Results:
- A correlation was found between FMD and HRS indices (MHA/MCA, MxHA/CxHA).
- Patients with myocardial perfusion defects showed lower MxHA/CxHA compared to those with normal SPECT.
- No direct relationship was observed between FMD and SPECT-detected perfusion alterations.
Conclusions:
- Hyperemic reactivity scintigraphy (HRS) demonstrates a relationship with flow-mediated dilatation (FMD).
- HRS can detect differences in patients with myocardial perfusion defects.
- HRS may provide supplementary diagnostic information to standard myocardial scintigraphy.
Objective:
The aim of this study was to compare a recently described method to evaluate endothelial function; the hyperemic reactivity scintigraphy (HRS) with the ultrasonographic flow-mediated dilatation (FMD) in brachial artery and its relationship with myocardial SPECT.
Methods:
42 consecutive patients that underwent myocardial scintigraphy were included. Thirty-six patients had simultaneous measurement of FMD. Both studies were obtained after 5 minutes occlusion of the upper arm with a blood pressure cuff inflated at 250 mmHg. HRS was performed dynamically at rate 1 frame/sec during 3 minutes after intravenous injection of 740 MBq of Tc-99 sestamibi. Time-activity curves allowed obtaining the following indexes: medium hyperemic activity/medium contrallateral activity (MHA/MCA) and maximum hyperemic activity/maximum contrallateral activity (MxHA/CxHA).
Results:
In 13 patients SPECT was normal. Twenty-nine patients had perfusion defects in scintigraphy. There was relationship between the FMD and the MHA/MCA (r = 0.23; p = 0.018) and the FMD and the MxHA/CxHA (r = 0.18; p = 0.05). Patients with alterations in the SPECT had an index MxHA/CxHA lower than patients with normal SPECT (1.8 +/- 0.2 vs 1.5 +/- 0.4; p = 0.04). We did not find relationship between FMD and alterations in SPECT.
Conclusions:
There is relationship between FMD and HRS. HRS is lower in patients with perfusion defects in the SPECT. HRS could provide additional value to myocardial scintigraphy.
