THE USE OF STANDARD IMAGING TECHNIQUES AND THEIR DIAGNOSTIC-VALUE IN THE WORK-UP OF RENAL COLIC IN THE SETTING OF INTRACTABLE FLANK PAIN

Objectives. This study reviews the rate at which diagnostic imaging te chniques are used in patients with intractable flank pain attributed t o renal colic who are admitted to the hospital through the emergency r oom and determines the diagnostic values of plain film of the abdomen (kidney, ureter, bladder [KUB]) and of ultrasonography (US) of the uri nary tract, using intravenous urography (IVU) as the gold standard for establishing the presence of a calculus. Methods. We reviewed the med ical records of 288 patients who were admitted to our medical center o ver a period of 5 consecutive years for intractable flank pain, the ad mission and working diagnosis in all cases being that of renal colic, and we retrieved all data pertaining to their diagnostic evaluation. R esults. A total of 265 patients (92%) were subjected to KUB, 158 (55%) to IVU, and 135 (45%) to US of the renal-urinary tract. Two diagnosti c imaging techniques were used in the same patient in the following co mbinations: KUB and IVU in 146 patients (51%), KUB and US in 110 (38%) , and IVU and US in 60 (21%). Three imaging techniques (IVU, KUB, and US) were utilized in 54 patients (19%). The sensitivity and specificit y of KUB alone were 95% and 65%, respectively, and the positive and ne gative predictive values were 82% and 88%. The sensitivity of US alone was 93%, its specificity 83%, the positive predictive value 93%, and the negative predictive value 83%. The sensitivity of combined KUB and US (requiring both tests to be positive for diagnosing the presence o f a calculus) was 89%, the specificity 100%, the positive predictive v alue 100%, and the negative predictive value 81%. Conclusions. Our dat a indicate that combining US with KUB provides the best diagnostic alg orithm that approaches the yield of IVU in excluding the presence of a calculus in the renal-urinary tract in patients who present with intr actable flank pain.