Respiratory gated multidetector computed tomography: applicable for diagnostic abdominal imaging?

Area of Science:

• Medical Imaging
• Radiology
• Diagnostic Technology

Background:

• Multi-detector computed tomography (MDCT) is crucial for abdominal imaging.
• Respiratory motion artifacts can degrade image quality in abdominal CT.
• Respiratory gating (RG) aims to minimize motion artifacts by synchronizing image acquisition with breathing patterns.

Purpose of the Study:

• To assess the diagnostic performance and image quality of a respiratory-gated (RG) technique for contrast-enhanced MDCT of the upper abdomen.
• To compare the accuracy of RG imaging with traditional breath-hold (BH) techniques for visualizing abdominal organs and major vessels.

Main Methods:

• Forty-five adult patients underwent multiphasic, contrast-enhanced abdominal CT using a dedicated respiratory gating hardware.
• RG images were acquired during free breathing between early arterial and portal venous phases.
• Two radiologists qualitatively and quantitatively compared RG and BH images using statistical analysis (Mann Whitney U test).

Main Results:

• RG scans showed significantly poorer scores for luminal opacification and contoural integrity of intrahepatic vascular structures compared to BH scans (p<0.001).
• Image noise levels were also statistically significantly higher in RG scans (p<0.001).
• Scores for RG scans were rated poor to moderate, while BH scans were rated good to excellent.

Conclusions:

• The current respiratory gating technique demonstrates limitations in achieving diagnostic image quality for upper abdominal contrast-enhanced MDCT.
• Significant differences in image quality metrics highlight the superiority of breath-hold techniques for this application.
• Further technological advancements in respiratory gating are necessary for potential routine clinical use in specific patient populations.