The effect of 1.5 T cardiac magnetic resonance on human circulating leucocytes

Area of Science:

• Medical Imaging
• Biophysics
• Hematology

Background:

• Cardiovascular magnetic resonance (CMR) is a non-ionizing imaging technique.
• Concerns exist regarding potential biological effects of CMR, prompting comparisons to ionizing radiation techniques.
• Investigating CMR's acute effects on cellular components is crucial for safety assessments.

Purpose of the Study:

• To evaluate the acute impact of 1.5 Tesla CMR on leukocyte DNA integrity, cell counts, and function.
• To assess these effects both in vitro using isolated cells and in vivo in a patient cohort.

Main Methods:

• In vitro: Peripheral blood mononuclear cells (PBMCs) from healthy volunteers were analyzed for histone H2AX phosphorylation (γ-H2AX) and functional parameters post-CMR exposure.
• In vivo: Blood samples from 64 patients were collected before and after a standard CMR scan to measure γ-H2AX expression and leukocyte counts.
• Flow cytometry was the primary technique for quantifying cellular changes and DNA damage markers.

Main Results:

• CMR exposure did not induce significant DNA damage (γ-H2AX expression) in vitro or in vivo.
• In vitro, cell integrity and function of PBMCs remained unchanged after CMR.
• A statistically significant reduction in circulating T cells was observed in vivo following CMR, with marked inter-patient variations in γ-H2AX.
• Inter-individual variability in γ-H2AX necessitates caution when interpreting this marker in small studies.

Conclusions:

• 1.5T CMR is not associated with DNA damage in leukocytes, either in vitro or in vivo.
• CMR does not impair leukocyte viability or function in laboratory settings.
• A significant decrease in viable leukocytes, particularly T cells, occurs in vivo after CMR exposure.
• The significant inter-patient variability in γ-H2AX suggests it may not be a universally reliable biomarker for CMR-induced DNA damage.