Diffusion weighted magnetic resonance imaging helps detect pyelonephritis in infants

Free breathing diffusion weighted magnetic resonance (DWI) represents a promising approach for detecting pyelonephritic lesions in nonsedated infants, as shown in a study.

Researchers evaluated the feasibility and performance of DWI as compared with 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy in 32 children <6 months of age who had symptomatic urinary tract infection (UTI). DWI was performed using a free breathing protocol without the use of sedation.

Twenty-five infants completed both DWI and DMSA examinations. The median age of this group was 1.7 months. There were focal uptake reductions detected on the DMSA images in 12 (24 percent) of the 50 kidneys, with the DWI method demonstrating a fair to good agreement with DMSA (k=0.50; p<0.0001).

Pyelonephritis was the consensus diagnosis in eight (16 percent) of the 50 kidneys, with DWI detecting the condition in seven of these kidneys.

DWI yielded no false positive results in the diagnosis of pyelonephritis.

DMSA scintigraphy is a well-established method for detecting pyelonephritis and renal damage, although it has inadequacies in availability, spatial resolution and detection of congenital malformations, the researchers said. On the other hand, DWI has been shown to have a high sensitivity in children without the use of invasive procedures, contrast agents or ionizing radiation. The current study shows that such an approach is feasible for detection of pyelonephritic lesions in nonsedated infants.

The researchers called for further validation of the performance of DWI to establish the utility of the method. This is in light of current feasibility study limitations, such as the limited number of patients.