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Updated: Oct 11, 2026

Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection
Published on: October 12, 2017
[Diagnostic evaluation of magnetic resonance urography in urinary tract dilatation and obstruction]
Objective:
To evaluate the diagnostic value of magnetic resonance urography (MRU).
Methods:
Two hundred and one patients were examined, 92 patients with urinary tract dilatation using a modified, heavily T2-weighted fast spin-echo pulse sequence and fat-suppression pulse aid. Postprocedure processing was performed with a maximum-intensity-projection (MIP) algorithm.
Results:
In the 92 patients with urinary tract dilatation, 86 had obstructive urinary tract dilatation 6 non-obstructive urinary tract dilatation. In the 86 patients, 14 had ureteral carcinoma, 19 calculus, and 13 benign stricture, 23 congenital ureteral stricture/or with anomalies, 7 ureteral obstructive caused by extrinsic pelvis disease, and 10 bladder carcinoma involved ureter. In the 6 patients, 5 had nervous bladder. MR urography provided the high-resolution image of the urinary tract and determined the presence of obstruction.
Conclusion:
MR urography is a reliable noninvasive method for depicting the urinary tract.
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