Comparative Study of Non-Contrast Enhanced Spiral CT Scan to Ultrasonography in the Diagnosis of Acute Renal Colic

Abstract

Objective: To evaluate the sensitivity and specificity of noncontrast spiral CT scan in ureteric colic with 
comparative evaluation of ultrasonography. 
Study Design: Prospective comparative study. 
Place and Duration of Study: This study was conducted at the Dept. of Radiology, Nishtar Medical College and 
Hospital, Multan from June, 2010 to June, 2011. 
Materials and Methods: 62 patients with flank pain were examined with both ultrasonography and non contrast 
enhanced 16 slice spiral CT scan over a period of one year. Both techniques were used to determine the presence, 
size, and location of ureteric stone, and the presence or absence of secondary signs like ureteral and calyceal 
dilatation, stranding of perinephric, periureteric fat and soft tissue rim sign 
Results: 43 of the 62 patients were confirmed as having ureteric calculi based on stone recovery or urological 
intervention. Ultrasound showed 93% sensitivity and 95% specificity in the diagnosis of ureterolithiasis. CT scan 
showed 91% sensitivity and 95% specificity respectively. Hydronephrosis was seen in all patients that were positive 
for ureteric calculi. Most common site of calculus was distal ureter. Perinephric fluid was demonstrated in three 
patients. Perinephric stranding was seen in 26 cases, and periureteric stranding in three patients on CT scan. 
Pathology unrelated to urinary stone disease was demonstrated in six patients 
Conclusion: Although both modalities were excellent for detecting ureteric stones, consideration of cost and 
radiation lead us to suggest that ultrasound be employed first and CT scan be reserved for when ultrasound is 
unavailable or non-diagnostic