Fossa navicularis (urethra)

Last revised by Dr Francis Deng on 08 Sep 2020

The fossa navicularis refers to a normal mild dilatation of the urethra. It occurs at the most distal/downstream portion of the urethra.

It is more evident in males, where it occurs in the penile/pendulous urethra, near the urethral meatus. There is also a fossa navicularis in women: the more flexible segment of the urethra between the rigid incisura intermuscularis and the collagenous meatus.

The fossa navicularis is where the balloon is positioned during a retrograde / ascending urethrogram (RUG/ASU).

This fossa navicularis of the urethra should not be confused for the bony defect in the clivus of the same name: fossa navicularis.

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