Pediatric Cyclophosphamide Induced Cystitis Etiology: in 70% of patients given high doses of cyclophsphamideImaging: thick hyperemic bladder wall, clots in bladderClinical: severe hemorrhagic cystitis Radiology Cases of Cyclophosphamide Induced Cystitis Transverse (above) and sagittal (below) US of the pelvis shows an extremely thick-walled bladder containing echogenic debris and clots.