Indications and techniques of mr urography

Abstract

Magnetic Resonance Urography (MRU) provides a comprehensive assessment of both morphology and function of the urinary system by using various sequences of T1W, T2W, 2D and 3D. T1W and T2W 2D images are optimal to evaluate the morphology of the kidneys and the urinary tract. Fast gradient echo 3D T1W sequence with the use of fat saturation technique (Fatsat or Dixon sequences), gadolinium administration, diuretic maneuver, and maximum intensity projection allows visualization of the urinary tract similar to that of conventional intravenous urography. MRU is also helpful in investigating renal function based on the hemodynamic study of contrast medium. Recent data prove that MRU, except for the study of renal calculi, is not inferior to computed tomographic urography (CTU) in evaluating diseases of the urinary system such as neoplasm, malformation and obstruction. MRU is an alternative to CTU when CTU is contraindicated. This article aims to review the techniques of MRU to optimize visualization of the urinary system and their indications in daily practice. Key words: MRU, MR hydrography, MR dynamic