Gonad dose to children in voiding urethrocystography performed with 70-mm image-intensifier fluorography

A new recommendation for febrile urinary tract infection in children aged 2-24 months: Tepecik UTI Guideline-2

AIM

Urinary tract infections (UTIs) represent a common febrile illness in infancy. The study compared two UTI guidelines in terms of number of imaging studies, presence of parenchymal damage and radiation exposure in patients with the first febrile UTI between 2 and 24 months of age.

METHOD

The results of Tepecik UTI Guideline-1 used until 2012 (Group 1, n = 105) were retrospectively compared with Tepecik UTI Guideline-2 (Group 2) used after 2013. In Group 1, urinary tract ultrasonography (US), dimercaptosuccinic acid (DMSA) and voiding cystourethrography (VCUG) were made in all patients. In Group 2, if the US result was abnormal, patients were evaluated with VCUG and DMSA. If the US was normal, only DMSA was performed. If the DMSA was abnormal, the VCUG was undergone (n: 43, 40.9%).

RESULTS

The abnormal VCUG detection rate was 69.2% in Group 1 and 30.8% in Group 2 (p = 0.09). Sensitivity and specificity of US in the diagnosis of vesicoureteral reflux (VUR) was 15.9% and 96.7% in Group 1 and 61.5% and 70.5% in Group 2, respectively. Abnormal DMSA findings were observed among 33.3% (Groups 1) and 66.7% (Groups 2) subjects, respectively (p > 0.05). The median radiation exposure (500 mrem) of patients in Group 1 was statistically significantly higher than those in Group 2 (200 mrem) (p < 0.001).

CONCLUSION

The VCUG should not be the first examination to be considered in such patients. We think that Tepecik UTI Guideline-2 reduces unnecessary invasive procedure and radiation exposure and not missed VUR in the management of children with UTI at 2-24 months. Needs prospective follow-up studies before considering this recommendation.

Comparison of direct radionuclide cystography and voiding cystourethrography in detecting vesicoureteral reflux

BACKGROUND

Fluoroscopic voiding cystourethrography (VCUG) is a widely used imaging test for the diagnosis of vesicoureteral reflux (VUR). However, high gonadal radiation and intermittent imaging are the main disadvantages of VCUG. Direct radionuclide cystography (DRC) has been advocated for the detection of VUR with increased sensitivity and low radiation doses, however, having the disadvantage of providing less anatomical details for urethral evaluation. In this study, DRC has been compared with standard fluoroscopic VCUG for detection of VUR.

METHODS

A total of 41 children (82 kidney ureter units, KUU) aged 1 month-126 months (median, 15 months) were studied sequentially using DRC and VCUG. The indications of VUR studied were urinary tract infection in 29 children, VUR follow up in eight children and antenatal dilatation history in four children.

RESULTS

A total of 18 refluxing ureters were detected by DRC, 22 refluxing ureters by VCUG and 14 refluxing ureters by both methods. The two methods were concordant for the detection and exclusion of VUR in 85% of KUU. VUR was missed by VCUG in four KUU (three severe, one mild) whereas VUR was missed by DRC in eight KUU (four grade I, four grade III).

CONCLUSIONS

There was a good correlation between DRC and VCUG in the evaluation of VUR. DRC provides continuous monitoring and low gonadal radiation exposure. DRC can be used in the diagnosis of VUR as an alternative to VCUG in selected cases.

Ovarian radiation dose during dynamic cystourethrography using videorecording and photofluorography

The ovarian radiation dose in dynamic cystourethrography was estimated by thermoluminescence dosimetry in a phantom and in 26 patients. The urodynamic examination technique was standardized and included fluoroscopy with videorecording and rapid sequence 100 mm fluorography. The examination was performed in the lateral position with dosimeters in the vagina, uterine cavity and rectum. The total dose in the midline was 13 mGy per examination, which compares with 12 mGy in urography.

Radiation doses to children at urologic radiography

At urologic radiography of infants and children, the energy imparted and the absorbed doses to gonads, breasts and thyroid were measured and the mean absorbed dose to the bone marrow calculated. The influence on the doses of different screen-film systems, numbers of exposures and the projection used was analysed. The risk of future radiation induced biologic effects was calculated.

Fluoroscopy without the grid: a method of reducing the radiation dose

The anti-scatter grid has been removed from the fluoroscopic set during the course of over 80 contrast examinations performed routinely during the ordinary workload of a busy paediatric radiology department. This manoeuvre approximately halves the radiation dose to the patient during both fluoroscopy and radiography. Our experience suggests that the degree of loss of contrast consequent on the abandonment of the grid is diagnostically acceptable during many examinations performed on children (of all ages), when balanced against the lower radiation dose received. In addition, an assessment has been made of the "contrast improvement factor" of the grids in two fluoroscopic sets in common use, using tissue-equivalent phantoms of various thicknesses. Although the contrast is significantly improved by the use of the grid, to a degree dependent on various factors, the relevance of this improvement in clinical radiology will depend on exactly what information is being sought. It is recommended that radiologists should use the grid with discretion when performing fluoroscopic examinations on children and that the apparatus for such examinations should have the capability for easy removal and reintroduction of the grid.

Renography as a prognostic index of urinary tract problems in childhood

Many radiological methods are used in investigating urinary tract problems in children, and some are poorly tolerated. The simplest and most acceptable technique is isotope renography. Its value has been assessed in predicting the outcome of urinary tract problems in 91 children over the age of 2 years presenting consecutively over a period of 3 months. The results of initial assessment by renography and radiography have been compared with the final clinical assessment 7 years later. 35 patients were identified as being "at risk" and all of these had abnormal renograms and radiograms. Normal renographys was found unexpectedly in some patients with severe reflux but with a good final result. It is concluded that renography can be used to screen children with urinary tract infection, thereby excluding the less acceptable radiological investigations unless the renogram is abnormal.