Comparison of contrast-enhanced color Doppler imaging (CDI), computed tomography (CT), and magnetic resonance imaging (MRI) for the detection of crossing vessels in patients with ureteropelvic junction obstruction (UPJO).

OBJECTIVE: To assess the use of contrast-enhanced color Doppler imaging (CDI), computed tomography (CT), and magnetic resonance imaging (MRI) for the detection of crossing vessels at the ureteropelvic junction (UPJ) in patients with ureteropelvic junction obstruction (UPJO).

MATERIALS AND METHODS: Forty-eight patients aged 18-69 yr (mean age, 52) who had been diagnosed with an UPJO on intravenous pyelography and diuretic renography were included. Contrast-enhanced CDI was performed by using both color Doppler frequency and color Doppler amplitude ("Power") modes. Spiral CT was performed by using a three-phase CT (arterial, venous, and excretory phases) allowing for CT angiography. MRI technique included dual-phase magnetic resonance angiography (arterial, venous) for the assessment of respective arteries and veins. The type (ie, arterial or venous) and position of the vessel relative to the UPJ (ie, anterior or posterior) were assessed. The CDI, CT, and MRI findings were correlated with the surgical findings at laparoscopic pyeloplasty.

RESULTS: Forty-four of 48 patients (92%) demonstrated crossing vessels at subsequent laparoscopy. Altogether a total of 60 vessels were detected. Contrast-enhanced CDI and MRI correctly detected all crossing vessels (accuracy, 100%), whereas CT missed four posterior crossing veins (accuracy, 93%).

CONCLUSION: Contrast-enhanced CDI is recommended as first-line imaging modality for the detection of crossing vessels in patients with UPJO.