The Use of Ultrasonography in Evaluating Adults with Febrile Urinary Tract Infection

Abstract

Ultrasonographic study of patients with febrile UTI should be limited only to those with a duration of fever > or = 3 days and a history of urolithiasis. Ultrasonographic study should also be considered in febrile UTI patients with diabetes mellitus.

Predicting the Need for Radiologic Imaging in Adults with Febrile Urinary Tract Infection

“…This is comparable to previous studies involving both men and women [15,18,[29][30][31][32]. However, we did not find an association between fever duration and elevated risk of underlying urinary tract abnormality [11,13,14,30]. This is probably because, in our study, the majority of patients with pyonephrosis underwent draining before the third day of antimicrobial treatment.…”

“…First, the sample size is relatively small, but according to the rule of thumb (1 predictor for 10 outcomes), the study still had reliable power [28]. In addition, compared with previous studies that addressed risk factors for urinary tract abnormalities in patients with UTI, our study is the largest prospective study thus far [11,14,16,18]. Second, we considered the radiologic outcome of patients without imaging to be normal provided that the clinical outcome was unremarkable.…”

“…The selection of potential predictors was based on known risk factors for complicated outcome of febrile UTI, such as the development of struvite stones. Therefore, a history of urolithiasis was included, as was a urine pH у7.0, because struvite will only precipitate in an environment with a pH of at least 7.2 [14,[24][25][26]. In addition, the glomerular filtration rate (GFR) may be halved once a pyelum is completely obstructed.…”

Computerized tomography attenuation values can be used to differentiate hydronephrosis from pyonephrosis

“…Therefore, the radiologic investigations gain more importance to establish the diagnosis in a quick and appropriate manner. Of the commonly applied modalities, while sonography of the affected kidney demonstrates hydronephrosis accompanied with fluid-debris levels within the dilated collecting system [2,5], CT evaluation is often associated with nonspecific findings such as thickening of the renal pelvis and stranding of the perirenal fat [1,9,10]. As a result of these suspicious but not indicative of radiologic findings, most of the patients are diagnosed during the percutaneous drainage of the collecting system either during nephrostomy tube placement or percutaneous nephrolithotomy procedure.…”

“…Related to this issue, while clinical symptoms like high fever, chills, tenderness over the flank and even septic state in a group of cases are highly indicative of a proper diagnosis, radiologic evaluation may not be indicative enough with some findings similar to hydronephrosis [2]. Among the radiologic means used, in addition to the detection of pelvicalyceal dilation and the possible etiologic factors (stones and tumors even in a non-functioning kidney) in general [3,4], ultrasonography of the affected kidney can further demonstrate the echogenic material together with fluid-debris levels within the dilated collecting system as the most prominent findings for pyonephrosis [2,5]. On the other hand, magnetic resonance imaging (MRI) has also been used in the differential diagnosis [6], and although the presence of a high-signal hydronephrosis in patients with suspected sepsis can be attributed to pyonephrosis, this situation seems to be very…”