Practice Rational Imaging

Investigating urinary tract infections in children

BMJ 2013; 346 doi: (Published 30 January 2013) Cite this as: BMJ 2013;346:e8654

Re: Investigating urinary tract infections in children

Dear Editor,

I thank the authors for their detailed article addressing the a very common paediatric problem.
Perhaps I may suggest a correction and add some comments which I feel are crucial for a complete assessment of a child with UTI especially the readership of the journal includes surgery/ radiology as well as paediatrics trainees.

1. Figure 1: May have been labelled inaccurately, as the compressed upper pole ureter is not associated with the dilated calyces. The Dilated system appears to be the Lower pole.

Whilst every clinician must be encouraged to look at the images first and then the report; especially in paediatrics where investigations may be performed at a local centre and a tertiary referral may be made subsequently; Images when reviewed by other clinicians are a static picture of a real time scan performed by the radiologist and may not always convey all the details appreciated by the later. All the accurate radiological information is crucial to allow the clinician to rule out/ diagnose all relevant pathologies.

There were some omissions in the article which should be addressed to ensure that the article covers all aspects of Urinary tract infections and not just an isloated Vesicoureteric reflux, as per the title of the article.

The article has used (apparently, taking into account timescales attached to usscan/ DMSA etc + appearance of the images ) all images of a boy with duplex left kidney, which requires careful interpretation due to the specific embryological issues as well as the sex of the child.

The article refers to a 5 month old boy with UTI who was eventually found to have no structural abnormality but most images appear to belong to a child(boy) with left duplex system. A duplex system has many wonderful embryologically relevant associations which require a careful interpretation.
As regards the role and value of the various investigations:
1. Usscan: Bladder images are extremely important even in young infants; especially in a boy evidence of an abnormal bladder (Large bladder/ thick walls) would be worrisome. We all have seen a child diagnosed only after a UTI to have a PU valves or subtle neuropathy. Presence of a dilated ureter would also be useful finding.

2. MCUG: The given picture does not delineate urethra. It is a good cystogram, but not a MCUG. It is not uncommon to receive a referral quoting a "normal MCUG" but without associated saved images of the voiding phase, even if the radiologist may ahve seen the voiding phase, its documentation is mandatory This may lead to a repeat study. Although Vesicoureteric reflux is a far commoner diagnosis, relevance and importance of obtaining a good quality voiding phase in a boy cannot be overemhphasised.

Early phase of bladder filling is important to assess any low grade reflux in other moieties, which may coexist in Duplex kidneys.

3. DMSA scan: The given figure appears to belong to the same patient, even it weren't, it should raise the possibility of a Duplex system with impaired upper moiety function. In some patients it may be extremely small and indeed called a "cryptic" duplex, wherein the DMSA may almost look "normal".

Automatic progression to a DMSA scan may at time be changed to a MAG3 scan when there is a possibility of a VUJ obstruction (in the absence of reflux but presence of a hydroureter).

The points raised above may address relatively rare cases; but crucial for a complete assessment of the patient as presenting symptmos will not offer a clue towards to anatomical diagnosis


Competing interests: No competing interests

10 February 2013
A B Abhyankar
Paediatric Surgeon/urologist
University Hospital of Wales, Cardiff