Role of intravenous urogram in investigation of urinary tract infection: an observational study

Meaning of ureter dilatation during ultrasonography in infants for evaluating vesicoureteral reflux

PURPOSE

To investigate the meaning of ureter dilatation during ultrasonography (US) in infants for evaluating vesicoureteral reflux (VUR).

MATERIALS AND METHODS

We retrospectively reviewed abdominal US images of infants who were diagnosed with urinary tract infection (UTI group) or only hydronephrosis without UTI (control group). Hydronephrosis (graded 0-4) and ureter dilatation (present or absent) were evaluated on each side with US. Voiding cystourethrography (VCUG) within 3 months time interval with US was also reviewed and VUR was graded (0-5) on each side. Hydronephrosis, ureter dilatation, and VUR were then compared between the two groups.

RESULTS

Four hundred and three infants (142 in the UTI group and 261 in the control group) were included and VCUG was performed in 129 infants (68 in UTI and 61 in control groups). VUR grades were not different between the two groups (p=0.252). Hydronephrosis grade was not related to VUR in either group (p>0.05). However, ureter dilatation had a significant relationship with VUR in the UTI group (p=0.015), even among patients with a high-grade VUR (p=0.005). Whereas, ureter dilatation was not associated with VUR in the control group (p=0.744). The relationship between ureter dilatation and VUR was different between the two groups for both all grades (p=0.014) and high-grade (p=0.004) VUR. Ureter dilatation had 66.7% sensitivity, 80.3% specificity, and 79.4% accuracy for evaluating high-grade VUR in the UTI group.

CONCLUSION

Ureter dilatation on US can be a helpful finding for detecting VUR in infants with UTI, but not infants without UTI.

Is intravenous urography necessary in the assessment of renal duplex system in children?

OBJECTIVE

Partial or complete duplication of the renal tract may be an incidental finding or may be associated with significant pathology. Accurate assessment is not always easy. This retrospective review was undertaken to determine whether intravenous urography (IVU) in combination with a DMSA renal scan provides significant additional information.

PATIENTS AND METHODS

Eighteen patients referred to our imaging department with a provisional diagnosis on ultrasound of renal tract duplication during a three year period were identified by searching the radiological computer files. The presenting features were urinary infection (13), abdominal pain (3) and abnormal antenatal sonography (2).

RESULTS

Four patients were found not to have renal duplication. There was concordance between the IVU and DMSA scan in seven. Additional clinically relevant information was obtained in three cases. A false negative result from the DMSA scan was found in four children and a false positive result in three.

CONCLUSION

In a significant number of cases of possible renal tract duplication, additional relevant information can be obtained from an IVU. Patient distress is minimised by combining the IVU and DMSA in one single episode of venous access. Review of the radiological images during the investigation allows minimisation of radiation dosage.

Imaging strategies for vesicoureteral reflux diagnosis

The prevalence of vesicoureteral reflux (VUR), although reported to be low in the general population, is high in children with urinary tract infection (UTI), first degree relatives of patients with known VUR and children with antenatal hydronephrosis. In addition, it has been shown that VUR and UTIs are associated with renal scarring, predisposing to serious long-term complications, i.e., hypertension, chronic renal insufficiency and complications of pregnancy. Therefore, diagnostic imaging for the detection of VUR in the high-risk groups of children has been a standard practice. However, none of these associations has been validated with controlled studies, and recently the value of identifying VUR after a symptomatic UTI has been questioned. In addition, several studies have shown that renal damage may occur in the absence of VUR. On the other hand, some patients, mainly males, may have primary renal damage, associated with high-grade VUR, without UTI. Recently, increasing skepticism has been noted concerning how and for whom it is important to investigate for VUR. It has been suggested that the absence of renal lesions after the first UTI in children may rule out VUR of clinical significance and reinforces the redundancy of invasive diagnostic techniques. Therefore, the priority of imaging strategies should focus on early identification of renal lesions to prevent further deterioration.