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

OBJECTIVES

To examine the value of an intravenous urogram (i.v.U) in patients with abnormal differential (99m)Tc dimercaptosuccinic acid (DMSA) uptake without scarring or ultrasound abnormality.

STUDY DESIGN

Forty patients (age 0-19 years) were identified over a two year period in whom the differential renal uptake was >10%, who had smooth renal outlines, and had no evidence of scarring. All patients had an ultrasound examination. Two had marked urological abnormalities on ultrasound and eight had a duplex system in the kidney with greater DMSA uptake. In 18 patients where no explanation was apparent for the discrepant DMSA uptake, an i.v.U was performed.

RESULTS

Eight patients had a normal i.v.U. In the remaining 10 patients, six had duplex systems without scarring and four had appearances of scarring in the kidney with reduced DMSA uptake.

CONCLUSIONS

In this small selected group an i.v.U will identify a significant number of patients with normal kidneys, unrecognised simple duplex systems, or scarring where the DMSA scan has been inconclusive. This will help in planning long term follow up.

Cystic retroperitoneal lymphangioma: treatment by image-guided percutaneous catheter drainage and sclerotherapy

Retroperitoneal cystic lymphangiomas are extremely rare and the majority are symptomatic during childhood. Although benign, they can compress and infiltrate vital structures. Surgery is curative but is associated with a high complication rate. An alternative treatment strategy is image-guided percutaneous catheter drainage of the lymphangioma followed by sclerotherapy. Resolution of a large retroperitoneal cystic lymphangioma in a 4-year-old child treated by this technique is reported. To our knowledge, this technique has not been previously described in this condition and we believe that it offers significant advantages over surgery.

A pictorial review of atlanto-axial rotatory fixation: key points for the radiologist

Atlanto-axial rotatory fixation (AARF) is a rare condition which occurs more commonly in children than in adults. The terminology can be confusing and the condition is also known as 'atlanto-axial rotatory subluxation' and 'atlanto-axial rotary dislocation'. Rotatory fixation is the preferred term, however, as in most cases the fixation occurs within the normal range of rotation of the joint. By definition, therefore, the joint is neither subluxed nor dislocated. AARF is a cause of acquired torticollis. Diagnosis can be difficult and is often delayed. The radiologist plays a key role in confirming the diagnosis. The classification system proposed by Fielding in 1977 is most frequently used and will be discussed in detail. Given that this classification system was devised in the days before computed tomography (CT), as well as the fact that combined atlanto-axial and atlanto-occipital rotatory subluxation (AORF) is omitted from the classification, we propose a modification to the classification of this rare but significant disorder. The radiological findings in six cases of AARF will be illustrated, including a case with associated atlanto-occipital subluxation. The pertinent literature is reviewed and a more comprehensive classification system proposed. The imaging approach to diagnosis and the orthopaedic approach to management will be discussed.

Paediatric Crohn's disease: a radiological review

Paediatric Crohn's disease can be a serious and complex condition which is not always easy to diagnose if it presents in an atypical manner. Although the pathological processes are the same in adults and children, the clinical presentation and disease distribution can be different in children. The impact of the disease can also be much more significant in a growing and developing child than in an adult. Numerous investigations are available to establish the diagnosis, define the complications and to demonstrate the extra-intestinal manifestations. Close cooperation is required between the clinician and radiologist when investigating a child suspected of having Crohn's disease or its symptoms to minimise the radiation dose and the psychological and physical trauma. We review the clinical and radiological aspects of Crohn's disease and discuss the imaging modalities available in diagnosing Crohn's disease and its complications and suggest an investigation pathway as used in our institution.

Evolving experience in the management of empyema thoracis

The optimal management of paediatric empyema thoracis remains controversial. The objective of the study was to analyse evolving experience in clinical presentation, management, outcome and factors contributing to adverse morbidity in thoracic empyema. Forty-seven patients presenting to a paediatric surgical centre were studied in three consecutive 6-y periods during 1980-97 to compare any change in the pattern of disease influencing diagnosis and management. Patients were categorized into two treatment groups: (i) conservative management (antibiotics and/or tube thoracostomy), (ii) thoracotomy. The median duration of illness prior to hospital admission was 10 d (range 1-42 d). Ultrasound was increasingly utilized in the diagnosis and staging of empyema and played an important role in directing definitive management. The presence of loculated pleural fluid determined the need for thoracotomy. Sixteen of 20 patients (80%) who were initially treated with thoracocentesis or tube thoracostomy eventually needed thoracotomy. There was a positive shift in management towards early thoracotomy resulting in prompt symptomatic recovery. Significant complications were noted in seven children who had delayed thoracotomy. These included recurrent empyema with lung abscess (n = 2), scoliosis (n = 2), restrictive lung disease (n = 1), bronchopleural fistula (n = 1) and sympathetic pericardial effusion (n = 1). An unfavourable experience with delayed thoracotomy during the study period has led us to adopt a more aggressive early operative approach to empyema thoracis. The decision to undertake thoracotomy has been influenced by the ultrasound findings of organized loculated pleural fluid. Delayed surgery was associated with adverse outcome. Whilst fibrinolytics and thoracoscopy may provide attractive options for early empyema, thoracotomy can hasten patient recovery regardless of the stage of disease. Prospective randomized trials are required to assess the ideal therapy for childhood empyema.

Oral contrast with computed tomography in the evaluation of blunt abdominal trauma in children

BACKGROUND

The use of oral contrast in evaluating children by computed tomography (CT) following blunt trauma is controversial. The aim of this study was to evaluate retrospectively the use of oral contrast with abdominal CT in children with suspected abdominal injury.

METHODS

The medical records of 101 children who underwent CT for abdominal trauma between 1993 and 1997 were reviewed for data pertaining to the mechanism of injury, clinical findings and management. Scans were reviewed by a paediatric radiologist and criteria of intestinal injury on CT described by Cox and Kuhn were used: (1) extraluminal air or contrast material, (2) focal area of thickening of bowel wall and mesentery, and (3) free intraperitoneal fluid in the absence of solid organ injury.

RESULTS

CT was performed within a median time of 2.4 (range 1-48) h after the injury. On 37 (62 per cent) of 60 scans in children who had oral contrast, the duodenum was not opacified after a mean delay of 30 min. Intestinal injury was suspected on CT in four children. In two children with CT evidence of intestinal injury (with/without oral contrast) rupture of the duodenojejunal flexure (n = 1) or ileal perforation (n = 1) was found at laparotomy. Two children had a false-positive scan, leading to negative laparotomy; one scan with oral contrast incorrectly suggested a duodenal leak and in another child CT without oral contrast showed thickening of bowel wall with free intraperitoneal fluid but no specific intestinal injury was identified at laparotomy. One patient had two negative CT scans (with and without oral contrast) and underwent laparotomy for clinical suspicion of bowel injury; rupture of the splenic flexure of the colon was found at laparotomy.

CONCLUSION

CT is not reliable for diagnosing intestinal injuries and this is not improved by use of oral contrast. Omission of oral contrast was not associated with delay in the diagnosis of intestinal injury. Since intestinal injuries are uncommon in children, a prospective multicentre study would determine more precisely the role of the routine use of oral contrast.

Digital radiography in paediatrics: radiation dose considerations and magnitude of possible dose reduction

The purpose of this study was to evaluate the radiation doses received by paediatric patients examined using a digital radiography unit, and to compare these doses with those received from conventional screen-film systems. In this way, guidelines could be drawn up concerning the magnitude of possible dose reductions achievable using digital radiography. The study was undertaken on approximately 900 patients undergoing abdomen, chest, pelvis and skull examinations. Patients were categorized into the following age groups: 0-1 month, 1-12 months, 1-5 years, 5-10 years and 10-15 years. Approximately half were X-rayed using a Fuji computed radiography system and half using a conventional screen-film system. Entrance surface dose was calculated from the recorded exposure parameters and measured X-ray tube outputs. Dose-area product was recorded directly. Image quality was assessed clinically using criteria recommended by a working group of the Commission of the European Communities. Apart from chest examinations, it was found possible to reduce doses by about 40% on average, by using a computed radiography system instead of a 600 speed screen-film combination. There was no significant difference in the dose for chest examinations. Satisfactory image quality can therefore be achieved by using computed radiography as a 1000 speed system for abdomen, pelvis and skull examinations, and as a 600 speed system for chests. Since very few departments appear to use screen-film systems of speeds greater than 400, then, for most departments, the use of computed radiography would result in dose reductions of at least 60%, or 33% for chests.

Isolated H-type recto-vaginal fistula associated with a vulval abscess

Recto-vaginal fistula is well known to occur in association with imperforate anus. We describe the case of an isolated "H-type" recto-vaginal fistula with no other anorectal abnormalities. The patient presented at 2 months of age with a vulval abscess and passing faeces per vaginum. Unilateral renal agenesis was also seen in this patient. We are unaware of any previous reports in the English-language literature of this isolated abnormality.

Magnetic resonance imaging of knee injuries in children

The purpose of this study was to evaluate the significance of meniscal appearances and determine the frequency of abnormalities seen on magnetic resonance (MR) imaging in children with knee injuries. We reviewed 78 consecutive MR imaging studies of 74 children aged 5-16 years with unfused epiphyses. Menisci were evaluated using conventional grading techniques. We used chi2 to compare the frequencies of medial and lateral meniscus and anterior cruciate ligament (ACL) tears with each other and with published data for children. Similarly, we compared the proportions of tears of these structures with published data. Arthroscopy results from 26 children were used to calculate sensitivity and specificity of MR imaging for meniscal tears, which were 100% (8/8) and 89% (16/18), respectively. The majority of studies (82%) had grade I or II signal intensity in one or both menisci. Arthroscopy results available in 33% of this group revealed normal menisci. Tears of the medial and lateral menisci were significantly more common than of the ACL. Injuries of the ACL were seen significantly less frequently than previously reported. Grade I or II meniscal signal intensity in children with knee injuries is consistent with a normal meniscus. Tears of the menisci are more common than ACL tears. MR imaging in this context appears reliable.

Ultrasound in children with osteomyelitis

Ultrasound (US) is a proven method of identifying subperiosteal abscess formation in osteomyelitis, but its precise role in the management of children with the condition is contentious. We reviewed nine children in whom US was used in the management of long bone osteomyelitis, including ribs. US was helpful in confirming the presence of a subperiosteal abscess in those children with an appropriate history and localizing signs. In these circumstances a bone scan is unnecessary. Problems were encountered when US failed to identify a subperiosteal abscess, because of the early stage of the disease process, and in multifocal abnormalities. In these circumstances a bone scan should still be performed.

Imaging strategies in the first 12 months after reduction of developmental dislocation of the hip

We have reviewed the records of 32 infants whose developmental dislocation of the hip (DDH) was treated by reduction and immobilization in a plaster cast. We examined 50 CT scans from 22 patients. The postreduction radiological studies led to a change of cast in 10 patients and, in five of them, the subluxation shown on CT scan was not seen in an earlier radiograph. Where reduction has been undertaken at the time of arthrography or in an older child, a plain radiograph may be adequate to confirm the position in the cast. In an infant, CT scans give superior information, have acceptable risks, and should be used in association with radiation protection measures.

The swollen leg and primary lymphoedema

Children who present with unilateral or bilateral swelling of the legs are often suspected of having a deep venous thrombosis. The incidence of deep venous thrombosis in children is low and lymphoedema may be a more appropriate diagnosis. Lymphoedema can be primary or secondary. In childhood, primary lymphoedema is more common and may be seen associated with other congenital abnormalities, such as cardiac anomalies or gonadal dysgenesis. Primary hypoplastic lymphoedema is the most often encountered type. It is more common in girls, especially around puberty, and is typically painless. Atypical presentations produce diagnostic confusion and may require imaging to confirm the presence, extent, and precise anatomical nature of the lymphatic dysplasia. This article describes four patients presenting with limb pain and reviews the clinical features and imaging options in children with suspected lymphoedema.

Current imaging of childhood urinary infections: prospective survey

OBJECTIVES

To assess whether ultrasonography alone is adequate for routine screening of childhood urinary infection, whether clinical features determine the need for further investigations, and which investigations are most appropriate.

DESIGN

Prospective survey of children with proved urinary infection and a preinvestigation record of clinical features. Ultrasonography and intravenous urography were routine, with choice of further studies determined by ultrasonographic findings.

SETTING

A children's hospital and two district general hospitals in Mersey region.

MAIN OUTCOME MEASURES

Sensitivity and specificity of ultrasonography both generally and in relation to clinical features. Accuracy of intravenous urography compared with radioisotope examinations.

RESULTS

Specificity of ultrasonography was good (99% (95% confidence interval 96% to 100%)) but sensitivity modest (43% (32% to 55%)), principally with respect to detecting vesicoureteric reflux and renal scarring. Among older children (aged 2-10 years) with positive ultrasound results and fever or vomiting the sensitivity in detecting reflux (with and without renal scarring) was 78% (62% to 89%) and the specificity 69% (60% to 78%); in detecting renal scarring (with and without reflux) the sensitivity was 100% (80% to 100%) and specificity 65% (56% to 74%). Renal scarring and obstructive uropathies were better assessed by radioisotope examinations than by intravenous urography.

CONCLUSIONS

Ultrasonography alone is inadequate for routine screening of childhood urinary infection. Though further investigations remain advisable in infants, in older children they can be restricted to a minority who have positive ultrasound examinations or have had fever or vomiting. Radioisotope examinations largely eliminate the need for intravenous urography.

Transient gyriform brightness on non-contrast enhanced computed tomography (CT) brain scan of seven infants

Spontaneous gyriform brightness seen on CT scan is an unusual finding unless associated with arteriovenous malformations (AVM). There are sporadic case reports in the literature of its occurrence in association with herpex simplex virus encephalitis (HSVE), purulent meningitis, following chemotherapy for leukaemia, in a child with chronic renal failure, and in a child with folic acid deficiency. We present a series of seven cases exhibiting this phenomenon, none of whom have AVMs, who have been scanned at this hospital in the first 2 1/2 years following the installation of a CT scanner. Four of the cases had congenital heart disease requiring corrective surgery or cardiac catheterisation. The other three had probable meningo-encephalitis. In all cases the gyriform brightness followed an ischaemic insult to the child's brain. We hypothesise that this phenomenon is an ischaemic response in the immature brain and that its occurrence is not so rare as the literature may suggest.

Detection of renal scarring by DMSA scanning--an experimental study

Using the established piglet model, renal scars were produced by a combination of vesicoureteric reflux and urinary infection. The presence and extent of scarring, as determined by postmortem examination, was compared with that detected by technetium 99m dimercaptosuccinic acid (DMSA) scans performed before sacrifice. Sixty female piglets (62 refluxing units) were studied. Overall the sensitivity (true-positive/(true-positive + false-negative)) of DMSA scanning in detecting macroscopic scarring was 85% and the specificity (true-negative/(true-negative + false-positive)) was 97%. There were five false-negatives, four of which were in kidneys with minor scarring and one in which there was major scarring. There were three false-positives. We conclude that DMSA scanning has a high specificity and sensitivity in detecting renal scars in female piglets, and suggest it is the preferred method for detecting renal scars in clinical practice.

The role of ultrasound in the management of ovarian masses in children

A retrospective study of 64 girls with ovarian cysts and tumours, diagnosed by ultrasound over 4 years, was undertaken. Most ovarian cysts were benign and conservative management with serial ultrasound scans helped to avoid unnecessary surgery. The incidence of surgery decreased from 18 operations in the first 2 years of the study to 10 operations in the second 2 years. All children for whom surgery is considered should have a pre-operative scan to determine whether the cyst has resolved. Immediate surgery is indicated in children who have a palpable mass, a solid mass, a mass associated with calcification, or a mass associated with persistent pyrexia. Appendix abscesses may mimic ovarian masses and can be correctly diagnosed by ultrasound.

Thyroid screening in congenital hypothyroidism: a review of 41 cases

Forty-one infants have been referred for thyroid scintigraphy following routine screening for congenital hypothyroidism: 14 (35%) were athyreotic, 19 (45%) had an ectopic thyroid, four (10%) were normal and four (10%) demonstrated other abnormalities. There was a female: male ratio of 4:1. Thyroid scintigraphy is a useful adjunct to biochemical screening.

'Hunt the thimble': a study of the radiology of ingested foreign bodies

The role of radiology in the management of patients with a history of ingested foreign bodies is reviewed in a retrospective study over a 2-year period in a Children's Hospital. If radiography was confined to those children who have a clinical history suggestive of foreign body impaction in the oesophagus, a foreign body aspiration or having swallowed a button battery, the work load and unnecessary radiation arising from this practice could be halved. This study demonstrates another misuse of radiological services.

Gastrografin in acute meconium ileus equivalent

Twenty-five (37%) patients with cystic fibrosis attending our clinic have experienced acute meconium ileus equivalent. In one year 37 of 40 episodes were treated with single dose oral Gastrografin with an 81% success rate, 75% being treated as outpatients. Patients found this treatment preferable to other recommended treatment.

Juvenile discitis

Over a period of three years four girls and two boys presented with discitis. All were less than 5 years old at presentation, and each had a short history of symptoms. Three were initially thought to have pathological defects of the abdomen. All children showed abnormal posturing with exaggerated lumbar lordosis. Diagnosis was essentially clinical. All cultures were sterile. The erythrocyte sedimentation rate was increased in all the children and all had mild pyrexia. Symptoms lasted from two to 8 weeks. Discitis should be considered in any child with fever, abnormal posturing, and refusal to walk. Early recognition may avoid unnecessary diagnostic and treatment procedures.

Functional intestinal obstruction in the neonate

The number of neonates with functional intestinal obstruction being admitted to this surgical unit is increasing. The obstruction may be transient and curable within a few days, or weeks or, more rarely, may be prolonged and intransigent, usually resulting in death despite parenteral nutrition. In the former group, the infants are often the result of an abnormal pregnancy or delivery. Recently, a small number of infants has been identified in whom prolonged jaundice is a notable feature, but the aetiology of this syndrome is not apparent. All of these infants must be screened to exclude mucoviscidosis, septicaemia, meningitis, and Hirschsprung's disease. Ideally, neonates suspected of having Hirschsprung's disease should not be submitted to surgery until after histological proof of the diagnosis. Infants with the rarer forms of intransigent ileus should be referred to special centres for intensive investigations, much of which would be somewhat experimental, in order to discover more about the aetiology of the various syndromes. For the adequate investigation and treatment of any these infants, an experienced team of clinicians, radiologists and pathologists is essential, and these infants should not be treated where the necessary facilities are unavailable.