Renal Duplex Systems

  

Case of Bilateral Renal Duplex System

Patient is a 36year old female, with h/o right ureterocele excision. 

USG was done initially, in which there was a tubular anechoic structure in right adnexa, mimicking a Hydrosalpinx. TVS confirmed the structure to be a dilated lower ureter, which was showing peristalsis and was seen in continuity with the right VUJ. This type of Ureteric Dilatation (Possibly secondary to reflux) can be easily mistaken for a hydrosalpinx. See the link below.

 CASE REPORTS: 'Duplex Megaureter Misdiagnosed as a Hydrosalpinx on Ultrasound '

Since there was right upper calyceal dilatation, Right Duplex System was suspected. LK was normal at time of USG.

LK shows two ureters	LK shows two ureters

CT images showed bilateral entirely duplicated ureters, bilateral upper moeity hydronephrosis. Right superior moeity ureter was seen inserted at a lower than normal position, with abnormal segmental dilatation of the distal 8-9cm.

Fetal PCA

FETAL POSTERIOR CEREBRAL ARTERY (PCA)

• In this anomaly, the Posterior Communicating artery(PCom) is prominent, with hypoplastic / Absent P1. Original Fetal PCA has absent P1, which is very rare.   

• Unilateral right OR Unilateral left PCA has an incidence of ~10% each. Bilateral Fetal PCA has an incidence of ~8%.

• The calibre of the PCom can be same as or greater than the PCA, and thereby the blood supply to the occipital lobes will be derived from the ICA through the PCom. The importance of this comes when ICA gets occluded, and will involve the ACA, MCA and PCA territories altogether (which will be difficult to explain by embolization). 

• Fetal origin of the posterior cerebral artery occurs when the embryonic posterior cerebral artery fails to regress.

Following are Axial Sections of NECT Brain of a middle aged female, which shows possible bilateral fetal PCAs. Here the Basilar artery bifurcation is not visualized and bilateral PComs are seen prominent (fig.3).

Small Basilar Artery anterior to Pons	Prominent bilateral PComs
Prominent bilateral PComs
P2 starts here!	Further continuation of PCAs(P2)