Background: Diffusion-weighted imaging plays a key role in the imaging of acute pyelonephritis by MRI. However the use of respiratory triggering is challenging and time-consuming in children. Diffusion tensor imaging without respiratory triggering might provide satisfying images of the moving kidneys.
Objective: To compare mean diffusivity diffusion tensor images obtained with free breathing with diffusion-weighted images obtained with respiratory triggering.
Materials and methods: Thirty-one children with suspected acute pyelonephritis underwent axial diffusion tensor imaging acquisition with free breathing and axial and coronal diffusion-weighted imaging acquisitions with respiratory triggering. We compared image quality and detection of nephritis between the two sequences.
Results: Diffusion tensor imaging demonstrated agreement with diffusion-weighted imaging in all cases, with no difference in the detection of nephritis areas. The image quality was significantly better with diffusion tensor imaging (P<0.01).
Conclusion: Diffusion tensor imaging could replace diffusion-weighted imaging for diagnosis of acute pyelonephritis.
Keywords: Children; Diffusion tensor imaging; Diffusion-weighted imaging; Kidney; Magnetic resonance imaging; Pyelonephritis; Urinary tract infection.