Ventilation distribution in rats: Part 2 – A comparison of electrical impedance tomography and hyperpolarised helium magnetic resonance imaging

BioMedical Engineering OnLine

Kimble R Dunster²  Marlies EJ Friese¹  John F Fraser²  Graham J Galloway¹  Gary J Cowin¹  Andreas Schibler² 

[1] Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia

[2] Medical Engineering, Queensland University of Technology, Brisbane, QLD, Australia

关键词: Functional lung imaging;    Ventilation distribution;    Hyperpolarized helium magnetic resonance lmaging;    Electrical impedance tomography;   

Others  :  798013
DOI  :  10.1186/1475-925X-11-68

 received in 2012-02-14, accepted in 2012-08-22,  发布年份 2012

【 摘 要 】

Background

Hyperpolarised helium MRI (He3 MRI) is a new technique that enables imaging of the air distribution within the lungs. This allows accurate determination of the ventilation distribution in vivo. The technique has the disadvantages of requiring an expensive helium isotope, complex apparatus and moving the patient to a compatible MRI scanner. Electrical impedance tomography (EIT) a non-invasive bedside technique that allows constant monitoring of lung impedance, which is dependent on changes in air space capacity in the lung. We have used He3MRI measurements of ventilation distribution as the gold standard for assessment of EIT.

Methods

Seven rats were ventilated in supine, prone, left and right lateral position with 70% helium/30% oxygen for EIT measurements and pure helium for He3 MRI. The same ventilator and settings were used for both measurements. Image dimensions, geometric centre and global in homogeneity index were calculated.

Results

EIT images were smaller and of lower resolution and contained less anatomical detail than those from He3 MRI. However, both methods could measure positional induced changes in lung ventilation, as assessed by the geometric centre. The global in homogeneity index were comparable between the techniques.

Conclusion

EIT is a suitable technique for monitoring ventilation distribution and inhomgeneity as assessed by comparison with He3 MRI.

【 授权许可】

   
2012 Dunster et al.; licensee BioMed Central Ltd.

【 图 表 】

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