Evaluating two respiratory correction methods for abdominal PET/MRI imaging

Abstract

Background To evaluate two respiratory correction methods for abdominal PET/MRI images and further to analyse the effects on standard uptake values (SUVs) of respiratory motion correction, 17 patients with 25 abdominal lesions on 18F-FDG PET/CT were scanned with PET/MRI. PET images were reconstructed using end-expiratory respiratory gating and multi-bin respiratory gating. Meanwhile, full data and the first 3 min and 20 s of data acquired both without respiratory gating were reconstructed for evaluation. Five parameters, including the SUVmax and SUVmean in the lesions, the SUVmean and standard deviation (SD) in the background, and the signal-to-noise ratio (SNR), were calculated and used for statistical comparisons. The differences in multi-bin respiratory gating and reconstruction of full data, relative to the reconstruction of the first 3 min and 20 s of data acquired, were calculated. Results Compared with PET/CT, the longer scanning time of abdominal PET/MRI makes respiratory motion correction necessary. The multi-bin respiratory gating correction could reduce the PET image blur and increase the SUVmax (11.98%) and SUVmean (13.12%) of the lesions significantly (p = 0.00), which was much more effective than end-expiratory respiratory gating for abdominal PET/MRI. The added value of SUVmax caused by respiratory motion correction has no significant difference compared with that caused by count loss with the correction (p = 0.39), which was rarely reported by previous studies. Conclusion Based on the current parameters, the method of multi-bin respiratory gating was more effective for respiratory motion correction in abdominal PET/MRI in comparisons with the method of end-respiratory gating. However, the increased noise in gated images, due to the fact that PET data get discarded, is partly responsible for the increase in SUVmax.

Application of Medical Image Navigation Technology in Minimally Invasive Puncture Robot

“…CT imaging produces radiation and is easily affected by the patient’s position and respiratory movements, making it difficult to differentiate between tissues and organs with similar tissue density [ 28 , 29 ]. MRI imaging time is extended, limited by the patient’s body position, breathing, and other factors, which may affect the quality and accuracy of imaging, and susceptible to interference from metallic substances, oxidized particles [ 30 , 31 , 32 ], etc.…”