CT Case 067
80-year-old female presents with four days of left flank pain and fever. She is febrile 39.5, HR 110, and hypotensive with SBP 90.
Blood results reveal an acute kidney injury with creatine 120 and lactate of 5
A Non-contrast CT scan of the abdomen is performed
Describe and interpret the CT images
Non-contrast CT shows a large (8mm) obstructing calculus in the left ureter with mild hydronephrosis.
The left kidney appears asymmetrically bulky compared to the right and there is also mild fat stranding in the perinephric space on left side. Fat stranding and mild renal enlargement can be seen in acute ureteric obstruction.
Clinical Pearls
Most common sites of stone obstruction in order of occurrence are vesicoureteric junction (VUJ – 60%), pelviureteric junction (PUJ), and less commonly at the pelvic brim where the ureters cross the iliac vessels.
On CT it is important to look for signs of complication of ureteric calculi, namely hydronephrosis, hydroureter and rupture of the calices.
It is also important to look at the rest of the CT for an alternative cause of symptoms (most importantly aortic pathology).
In patient with ureteric calculi, indications for urological referral and admission are;
- Acute kidney injury
- Evidence of hydronephrosis / hydroureter
- Evidence of infection – based on fever, elevated WCC, or evidence of infection on urinalysis
- Poorly controlled pain
- Single kidney
- Stone >/6mm – as stones of this size are far less likely to pass without intervention
This patient had ureteric calculi complicated by urosepsis. She was managed with antibiotic therapy and urgent cystoscopy and stent insertion, with a plan for lithotripsy as an outpatient.
References
- Hartung M. Abdominal CT: Flank pain. LITFL
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Emergency Medicine Education Fellow at Liverpool Hospital NSW. MBBS (Hons) Monash University. Interests in indigenous health and medical education. When not in the emergency department, can most likely be found running up some mountain training for the next ultramarathon.
Dr Leon Lam FRANZCR MBBS BSci(Med). Clinical Radiologist and Senior Staff Specialist at Liverpool Hospital, Sydney
Sydney-based Emergency Physician (MBBS, FACEM) working at Liverpool Hospital. Passionate about education, trainees and travel. Special interests include radiology, orthopaedics and trauma. Creator of the Sydney Emergency XRay interpretation day (SEXI).
Provisional fellow in emergency radiology, Liverpool hospital, Sydney. Other areas of interest include paediatric and cardiac imaging.