Case 13 Answer

OK, this was a tough one. The key was the line of stones in the mid-distal left ureter.

Answer: Steinstrasse (ie “street of stones”) secondary to recent renal stone lithotripsy 

Congrats to those who got it correct. After ECSWL (extracorporal shock wave lithotripsy), you get fragmentation of the large stone into smaller stones. These smaller stones pass and can cause hematuria and even obstruction (as seen here)

Reference: http://www.learningradiology.com/archives06/COW%20234-Steinstrasse/steinstrassecorrect.html