Diffusion tensor imaging of the human kidney: Does image registration permit scanning without respiratory triggering?

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• Diffusion Tensor Imaging (DTI) provides insights into tissue microstructure.
• Respiratory motion artifacts can degrade the quality of renal DTI.
• Respiratory triggering is a common technique to mitigate motion artifacts.

Purpose of the Study:

• To evaluate if image registration can eliminate the need for respiratory triggering in renal DTI.
• To assess the impact of registration on DTI parameters in transplanted and native kidneys.

Main Methods:

• Renal DTI was performed on 9 transplant recipients and 8 healthy volunteers with and without respiratory triggering.
• A multimodal nonrigid registration algorithm was applied to the DTI data.
• Image quality was assessed using Root Mean Square Error (RMSE) and Standard Deviation within Regions of Interest (SDROI).

Main Results:

• Image registration significantly reduced RMSE and SDROI for DTI parameters in both native and transplanted kidneys.
• No significant difference in RMSE or SDROI was observed between triggered and nontriggered DTI for transplanted kidneys after registration.
• In native kidneys, triggered DTI showed lower RMSE, but registration still improved overall quality.

Conclusions:

• Image registration effectively improves renal DTI quality for both native and transplanted kidneys.
• Respiratory triggering can be omitted for DTI of renal allografts when image registration is employed.
• Respiratory triggering remains advantageous for achieving optimal DTI quality in native kidneys.