Harmonic versus conventional ultrasound imaging of the urinary tract in children.

BACKGROUND

Harmonic imaging (HI) is a relatively new US method. Its usefulness in children has yet to be determined.

OBJECTIVE

To evaluate the value of HI in urinary tract imaging of infants and children.

MATERIALS AND

METHODS

The bladder and kidneys of 29 unselected patients, aged 2 months to 12.8 years (mean, 6.8 years), were examined from ventral and dorsal approaches using conventional (= fundamental) imaging (FI) (6.5 and 3.4 MHz) and HI (3.3 MHz). In addition to global image quality, visualization of bladder wall, retrovesical space, renal contrast to liver/spleen, the pelvicalyceal systems, and the difference between cortex and medulla were assessed. Parameters were rated by two independent examiners and statistical analysis was performed.

RESULTS

There were significant differences between the three imaging settings for all parameters studied (P<0.003). With the dorsal approach, HI was superior to FI for all parameters analysed (P<0.05). Using the ventral approach, a significant improvement of imaging with HI was found for the bladder and the renal pelvis (P<0.02).

CONCLUSIONS

HI is a useful additional tool for imaging the urinary tract in children of all ages. The method particularly improves visualization of the bladder and the kidney from a dorsal approach.