Low dose computed tomography in suspected acute renal colic.
OBJECTIVE
To evaluate whether computed tomography (CT) of the renal tract in suspected renal colic using reduced exposure factors maintains diagnostic accuracy.


METHODS
Prospective multi-centre cohort study. Patients with suspected renal colic were examined using computed tomography (CT) of the renal tract followed by intravenous urography (IVU) in four different centres with five different CT systems.


RESULTS
Sixty-nine patients with suspected renal colic had CT of the renal tract followed by IVU. CT was performed with reduced exposure factors, giving a mean CT effective dose of 3.5 (range 2.8-4.5) mSv compared with 1.5 mSv for IVU. Ureteric calculi were detected in 43 patients: CT and IVU detected 40 (93%) ureteric calculi. CT identified other lesions causing symptoms in five patients and identified renal calculi in 24 patients. IVU identified renal calculi in six patients and made false positive diagnosis of renal calculi in seven patients. Mean examination time for CT was 5 minutes and for IVU was 80 minutes.


CONCLUSIONS
CT examination at reduced exposure factors maintains the diagnostic accuracy recorded in other series.
Meagher
T
T
Department of Radiology, Stoke Mandeville Hospital Trust, Aylesbury, Buckinghamshire, UK. tom.meagher@smh.nhs.uk
Sukumar
V P
VP
Collingwood
J
J
Crawley
T
T
Schofield
D
D
Henson
J
J
Lakin
K
K
Connolly
D
D
Giles
J
J
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D003085:Colic / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000150:complications / Q000000981:diagnostic imaging; D007674:Kidney Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*