Adder head appearance is seen in:

Ans: a (Ureterocoele) Ref: Bailey, 24th ed, p. 1310Ureterocoele: Cystic enlargement of intramural portion of ureter. Adder heaed appearance in excretory urography is typical.Other important radiographic appearance* Spring onion appearance- Ureterocoele* Spider leg appearance- Polycystic kidney* Flower vase appearance- Horse shoe kidney* Rim sign or crescent sign- Hydronephrosis* Sandy patches, foetal head in pelvis- Schistosomiasis bladder* Golf hole ureter, thimble bladder- TB kidney* Soap bubble appearance- Hydronephrosis* Clubbing of calyces- Hydronephrosis* Meniscus sign- CBD stone* Reverse J sign with hydronephrosis- Retrocaval ureter* Drooping flower appearance- Ectopic ureter* Irregular filling defects, spider leg appearance- Renal cell carcinomaUrographically early filling of the bulbous terminal ureter is noted, a finding that has been referred as a spring onion appearanceSome notes on radiological investigations in urology* Rapid sequence urography is carried out in patients with suspected reno vascular hypertension.* Urethroscopy is confirmatory for stricture of urethra.* Infusion urography-in compromised renal function* Diuretic urography-PUJ obstruction* Micturating cysto urethrography-investigation of choice for VUR and posterior urethral valve.* Retrograde urethrogram is the best to visualize penile urethra.