MR pyelography in the assessment of hydroureteronephrosis: single-shot thick-slab RARE versus multislice HASTE sequences

Background: We used magnetic resonance (MR) pyelography to compare the value of thick-slab single-shot rapid acquisition with relaxation enhancement (RARE) sequence with that of multislice half-Fourier acquisition single-shot turbo-spin-echo (HASTE) sequence in evaluating the full spectrum of morphologic features in a group of patients with hydronephrosis. Methods: MR pyelographic images, with the use of thick-slab RARE and multislice HASTE sequences in 90 patients, were evaluated for image quality, presence of hydronephrosis, and level and cause of obstruction. Results: HASTE sequences provided images of better quality than did RARE sequences (p<0.001). There was no statistically significant difference in demonstrating the presence of hydronephrosis (p=0.5) and level of obstruction (p=0.125). Sensitivity, specificity, and accuracy in diagnosing cause of obstruction were 61.7%, 62.5%, and 62%, respectively, for RARE sequences and 80%, 82.5%, and 81%, respectively, for HASTE sequences, with a statistically significant difference (all p<0.05). Conclusion: Multislice HASTE sequence provides better diagnostic information than does thick-slab RARE sequence, particularly in evaluating the cause of obstruction