A novel use of attenuation value (Hounsfield unit) in non-contrast CT: diagnosis of urinary tract infection

Abstract

The attenuation value of the urine in the defined area of the bladder may aid in the diagnosis of urinary infection with high sensitivity and specificity and without any additional cost.

Hounsfield unit attenuation value can differentiate pyonephrosis from hydronephrosis and predict septic complications in patients with obstructive uropathy

“…To the best of our current knowledge, this study is the first to show that HU of the fluid in the dilated collecting system are associated with a higher risk of septic complications in patients with obstructive uropathy. CT attenuation values of bladder and renal pelvis urine have been previously used to predict the culture positivity in patients with stone disease 15 , 16 but the direct association between HU values and infectious complications after urinary drainage in the emergency setting has never been investigated in current literature. We found that patients who developed sepsis had higher preoperative HU values than those who did not experience infectious complications.…”

“…HU measurement is routinely performed in clinical practice to define hardness 7 , 8 and composition 9 , 10 of kidney stones, to predict the outcome of stone treatment 11 , 12 and to differentiate malignant from benign renal tumors 13 , 14 . Computerized tomography (CT) attenuation values of bladder and renal pelvis urine have also been used to predict the positivity of urine cultures with high sensitivity and specificity 15 , 16 . However, very little is known about the role of HU of dilated collecting systems in predicting infectious complications in patients with obstructive hydronephrosis.…”