Ureter megaureter

Hanna MK, Jeffs RD, Sturgess JM et al (1977) Ureteral structure and ultrastructure. III. The congenitally dilated ureter (megaureter). JUrol 117 24-27... 

Fig. 5.5. MR imaging of bilateral infundibulo-pelvic stenosis. T2-weighted sequence. The anomaly is associated with a right megaureter and with a segmental ureteral cystic dilatation to the left ureter...

Fig. 5.7a-c. Megacalycosis and megaureter, a US sagittal scan ofthe left kidney. Unusual cystic dilatation of all the calyces. A lithiasis is visible at the lower pole, b US of the pelvis showing an associated dilated ureter (1.8 cm between crosses), c MR urography typical megacalycosis of the left kidney... 

Ureteral dilatation, or hydroureter, is a frequent cause of a dilatation of the fetal urinary tract. Under normal conditions, on fetal or postnatal US, the normal ureter is not visualized. Once it is visible (Fig. 5.20), a urinary tract dilatation is present and must be investigated (Keller and Weiss 1993). The presence of a dilated ureter may correspond to primary megaureter (MU), to refluxing MU (see Chap. 11), to nonobstructive nonrefluxing hydro-ureter, or to secondary hydroureter. The various imaging techniques will be necessary in order to differentiate between these entities. 

Fig. 5.28a,b. Crural hernia of a left megaureter. MR imaging T2-weighted sequence, a Upright AP view, b Lateral view showing the anterior course of the ureter... 

Liu AHY, Dhillon HK, Diamond DA et al (1994) Clinical outcome and management of prenatally diagnosed primary megaureters. J Urol 152 614-617 Lucaya J, Enriquez G, Delgado R et al (1984) Infundibulopel-vic stenosis in children. AJR 142 471-474 Maizels M, Stephens FD (1980) Valves of the ureter as a cause of primary obstruction of the ureter. J Urol 123 742-746 Maizels M, Reisman ME, Flom LS et al (1992) Grading nephro-ureteral dilatation detected in the first year of life. JUrol 148 609-614... 

Fig. 8.3. IVU. Bilateral duplicated dysplastic kidney systems with megaureters and ureter dysmotility. Note dysplastic sacrum...

Fig. 11.20a,b. VUR and primary megaureter, a VCU left grade II VUR the right VUR is very subtle (arrowheads) because of the dilatation and obstruction of the ureter, b IVU typical right megaureter... 

In the megacystis-megaureter association, massive bilateral grade IV or V VUR is present. During micturition, the bladder empties normally through the urethra, but also through reflux into the ureters (Fig. 11.23a-d). At the end of micturition, the bladder is completely empty, but only for a very short time. It refills immediately with the refluxed urine ... 

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