Association between preterm brain injury and exposure to chorioamnionitis during fetal life

Preterm infants are susceptible to inflammation-induced white matter injury but the exposures that lead to this are uncertain. Histologic chorioamnionitis (HCA) reflects intrauterine inflammation, can trigger a fetal inflammatory response, and is closely associated with premature birth. In a cohort of 90 preterm infants with detailed placental histology and neonatal brain magnetic resonance imaging (MRI) data at term equivalent age, we used Tract-based Spatial Statistics (TBSS) to perform voxel-wise statistical comparison of fractional anisotropy (FA) data and computational morphometry analysis to compute the volumes of whole brain, tissue compartments and cerebrospinal fluid, to test the hypothesis that HCA is an independent antenatal risk factor for preterm brain injury. Twenty-six (29%) infants had HCA and this was associated with decreased FA in the genu, cingulum cingulate gyri, centrum semiovale, inferior longitudinal fasciculi, limbs of the internal capsule, external capsule and cerebellum (p < 0.05, corrected), independent of degree of prematurity, bronchopulmonary dysplasia and postnatal sepsis. This suggests that diffuse white matter injury begins in utero for a significant proportion of preterm infants, which focuses attention on the development of methods for detecting fetuses and placentas at risk as a means of reducing preterm brain injury.

Epigenomic profiling of preterm infants reveals DNA methylation differences at sites associated with neural function

DNA methylation (DNAm) plays a determining role in neural cell fate and provides a molecular link between early-life stress and neuropsychiatric disease. Preterm birth is a profound environmental stressor that is closely associated with alterations in connectivity of neural systems and long-term neuropsychiatric impairment. The aims of this study were to examine the relationship between preterm birth and DNAm, and to investigate factors that contribute to variance in DNAm. DNA was collected from preterm infants (birth<33 weeks gestation) and healthy controls (birth>37 weeks), and a genome-wide analysis of DNAm was performed; diffusion magnetic resonance imaging (dMRI) data were acquired from the preterm group. The major fasciculi were segmented, and fractional anisotropy, mean diffusivity and tract shape were calculated. Principal components (PC) analysis was used to investigate the contribution of MRI features and clinical variables to variance in DNAm. Differential methylation was found within 25 gene bodies and 58 promoters of protein-coding genes in preterm infants compared with controls; 10 of these have neural functions. Differences detected in the array were validated with pyrosequencing. Ninety-five percent of the variance in DNAm in preterm infants was explained by 23 PCs; corticospinal tract shape associated with 6th PC, and gender and early nutritional exposure associated with the 7th PC. Preterm birth is associated with alterations in the methylome at sites that influence neural development and function. Differential methylation analysis has identified several promising candidate genes for understanding the genetic/epigenetic basis of preterm brain injury.

Tract shape modeling detects changes associated with preterm birth and neuroprotective treatment effects

Preterm birth is associated with altered connectivity of neural circuits. We developed a tract segmentation method that provides measures of tract shape and integrity (probabilistic neighborhood tractography, PNT) from diffusion MRI (dMRI) data to test the hypotheses: 1) preterm birth is associated with alterations in tract topology (R), and tract-averaged mean diffusivity (〈D〉) and fractional anisotropy (FA); 2) neural systems are separable based on tract-averaged dMRI parameters; and 3) PNT can detect neuroprotective treatment effects. dMRI data were collected from 87 preterm infants (mean gestational age 29(+1) weeks, range 23(+2) -34(+6)) at term equivalent age and 24 controls (mean gestational age 39(+6) weeks). PNT was used to segment eight major fasciculi, characterize topology, and extract tract-averaged〈D〉and FA. Tract topology was altered by preterm birth in all tracts except the splenium (p < 0.05, false discovery rate [FDR] corrected). After adjustment for age at scan, tract-averaged〈D〉was increased in the genu and splenium, right corticospinal tract (CST) and the left and right inferior longitudinal fasciculi (ILF) in preterm infants compared with controls (p < 0.05, FDR), while tract-averaged FA was decreased in the splenium and left ILF (p < 0.05, FDR). Specific fasciculi were separable based on tract-averaged〈D〉and FA values. There was a modest decrease in tract-averaged〈D〉in the splenium of preterm infants who had been exposed to antenatal MgSO4 for neuroprotection (p = 0.002). Tract topology is a biomarker of preterm brain injury. The data provide proof of concept that tract-averaged dMRI parameters have utility for evaluating tissue effects of perinatal neuroprotective strategies.

Imaging paediatric blunt abdominal trauma in the emergency department: ultrasound versus computed tomography

OBJECTIVE

To determine whether an abdominal ultrasound scan performed by paediatric radiologists is effective in the diagnosis of abdominal injuries in children.

METHOD

A retrospective cohort study was undertaken of all children who presented with blunt abdominal trauma to a paediatric teaching hospital (RHSC) over a 5-year period between 1 January 2001 and 31 December 2005. Hospital notes and radiology computer systems were interrogated and data were collected and analysed.

RESULTS

Of the 80 children with blunt abdominal trauma, 56 (70%) had abdominal imaging and 23 (30%) had no imaging. Of the 56 imaged, 48 (86%) had an USS of which 25 (52%) were positive (16 demonstrated solid organ injury, 8 free fluid and 1 suspected bladder rupture); 3 of these went on to have a CT scan. 23 had a normal USS; 2 of these children went on to have a CT scan because of a high index of suspicion for small bowel perforation due to their mechanism of injury and clinical signs. Both of these CT scans were normal. Eight children (14%) had a CT scan as the primary investigation, 6 of which (75%) were positive (5 demonstrated liver lacerations and 1 free fluid with no obvious source). All these abnormalities were demonstrated on follow-up USS. 23 children had no abdominal imaging and once their symptoms and signs had settled they were safely discharged home.

CONCLUSION

Abdominal USS performed by paediatric radiologists is an accurate method of assessing abdominal injuries. However, CT scanning can assess certain abnormalities such as pancreatic or duodenal injuries and small amounts of free intraperitoneal air more accurately. The importance of serial clinical examination must not be overlooked.

Incidental radiological diagnosis of rickets

Rickets fortunately remains rare in the United Kingdom, although its actual incidence is currently undetermined.1 Many still consider it to be a disease of poverty prevalent during the Victorian era. However, a number of recent articles have highlighted concern among British health professionals about the number of cases still being diagnosed in this country. These cases have nearly all involved non-Caucasian children who are considered to be at high risk due to skin colour, prolonged breast feeding, and low maternal vitamin D levels. Their presentations are variable ranging from failure to thrive, bone deformities, seizures, and even stridor. The diagnosis is usually made in babies and toddlers.We present a series of patients attending our accident and emergency (A&E) department, over a five month period, where the diagnosis of rickets was primarily a radiological diagnosis.

Can we abolish skull x rays for head injury?

OBJECTIVES

To assess the effect of a change in skull x ray policy on the rate of admission, use of computed tomography (CT), radiation dose per head injury, and detection of intracranial injuries; and to compare the characteristics of patients with normal and abnormal head CT.

DESIGN

Retrospective cohort study.

SETTING

UK paediatric teaching hospital emergency department.

PATIENTS

1535 patients aged between 1 and 14 years with a head injury presenting to the emergency department between 1 August 1998 and 31 July 1999 (control period), and 1867 presenting between 1 August 2002 and 31 July 2003 (first year of new skull x ray policy).

INTERVENTION

Hospital notes and computer systems were analysed and data were collected on all patients presenting with a head injury.

RESULTS

The abolition of skull x rays in children aged over 1 year prevented about 400 normal skull x rays being undertaken in period 2. The percentage of children undergoing CT rose from 1.0% to 2.1% with no change in the positive CT pick up rate (25.6% v 25.0%). There was no significant change in admission rate (10.9% v 10.1%), and a slight decrease in the radiation dose per head injury (0.042 mSv compared to 0.045 mSv).

CONCLUSIONS

Skull x rays can be abandoned in children aged 1 to 14 without a significant increase in admission rate, radiation dose per head injury, or missed intracranial injury. The mechanism and history of the injury and a reduced Glasgow coma scale are probably the most important indicators of significant head injury in children.

Imaging infants with head injury: effect of a change in policy

OBJECTIVE

Head injury is one of the commoner injuries presenting to the emergency department (ED). Infants are hard to assess clinically and emphasis has been placed on radiological examination. Skull radiographs, however, are not a reliable indicator of intracranial injury. As a result of this the policy in this ED was revised so that skull radiographs were only to be performed in those infants less than 1 year with visible evidence of head injury or a suspicious history for non-accidental injury.

METHODS

Retrospective cohort study of all infants less than 1 year who presented with head trauma to the ED of a paediatric teaching hospital between 1 August 1998 and 31 July 1999, and between 1 August 2002 and 31 July 2003. Hospital notes and radiology computer systems were examined and data were collected and analysed.

RESULTS

181 infants aged less than 1 year presenting to the ED in 1998/9 and 190 infants in 2002/3. Altogether 140 (77.3%) infants had a skull radiograph in 1998/9, five (3.6%) identified skull fractures. During 2002/3, 56 (29.5%) infants had a radiograph, a reduction of 47.5%, of which three (5.4%) had skull fractures. All fractures had reported haematomas to their scalp. The change in policy decreased the total radiation dose to the population by 9.4 mSv. No significant injuries were missed as a result of the change in policy.

INTERPRETATION

In infants under 1 year, unless non-accidental injury is suspected, it is suggested that skull radiographs should only be performed when there are visible signs of a head injury.

Fracture of the sternum in children

OBJECTIVE

Sternal fracture is poorly characterised in children. The purpose of this study was to gain insight into the mechanism, radiological characteristics, and accompanying injuries of sternal fracture in children.

METHODS

The study was retrospective. The records of all children who underwent plain radiography of the sternum, or computed tomography of the thorax after trauma, over a 40 month period in our paediatric hospital were reviewed for evidence of sternal fracture.

RESULTS

12 of 33 children identified had radiological evidence of sternal fracture. The age range of children with fractures was 5 to 12 years. Eleven children had fracture of the anterior cortex of the first or second sternebra of the body of the sternum. One child had fracture through the manubriosternal joint with posterior displacement of the body. Seven fractures resulted from direct blows to the anterior chest, five fractures resulted from hyperflexion injury of the thoracic spine. None were the result of motor vehicle crash. All fractures were isolated injuries.

CONCLUSIONS

Sternal fracture is uncommon in children. Injury may result from direct or indirect violence. The child's sternum is commonly fractured by more minor blunt trauma than generally recognised in the literature. All patients with sternal fracture after indirect violence should have careful examination of the spine. Patients with undisplaced anterior cortical fracture without other injury may be safely discharged from the emergency department.

Emmetropisation following preterm birth

BACKGROUND/AIMS

Even in the absence of retinopathy of prematurity (ROP), premature birth signals increased risk for abnormal refractive development. The present study examined the relation between clinical risk factors and refractive development among preterm infants without ROP.

METHODS

Cycloplegic refraction was measured at birth, term, 6, 12, and 48 months corrected age in a cohort of 59 preterm infants. Detailed perinatal history and cranial ultrasound data were collected. 40 full term (plus or minus 2 weeks) subjects were tested at birth, 6, and 12 months old.

RESULTS

Myopia and anisometropia were associated with prematurity (p<0.05). More variation in astigmatic axis was found among preterm infants (p<0.05) and a trend for more astigmatism (p<0.1). Emmetropisation occurred in the preterm infants so that at term age they did not differ from the fullterm group in astigmatism or anisometropia. However, preterm infants remained more myopic (less hyperopic) than the fullterm group at term (p<0.05) and those infants born <1500 g remained more anisometropic than their peers until 6 months (p<0.05). Infants with abnormal cranial ultrasound were at risk for higher hyperopia (p<0.05). Other clinical risk factors were not associated with differences in refractive development. At 4 years of age 19% of the preterm group had clinically significant refractive errors.

CONCLUSION

Preterm infants without ROP had high rates of refractive error. The early emmetropisation process differed from that of the fullterm group but neither clinical risk factors nor measures of early refractive error were predictive of refractive outcome at 4 years.

Management of simple renal cysts in children

Simple renal cysts are uncommon in children and their presentation and management has changed with increasing use of ultrasound scans. The aim of this study was to review our experience and highlight some peculiarities in diagnosis and management of these cases. Eight cases were diagnosed and two symptomatic cases underwent aspiration under ultrasound guidance; one case recurred and required re-aspiration. Differentiation of simple renal cysts from other cystic lesions of the kidney, aspiration of symptomatic cysts and the importance of long-term follow-up are discussed.

A novel acropectoral syndrome maps to chromosome 7q36

F syndrome (acropectorovertebral syndrome) is a dominantly inherited skeletal dysplasia affecting the hands, feet, sternum, and lumbosacral spine, which has previously been described in only two families. Here we report a six generation Turkish family with a related but distinct dominantly inherited acropectoral syndrome. All 22 affected subjects have soft tissue syndactyly of all fingers and all toes and 14 also have preaxial polydactyly of the hands and/or feet. In addition, 14 have a prominent upper sternum and/or a blind ending, inverted U shaped sinus in the anterior chest wall. Linkage studies and haplotype analysis carried out in 16 affected and nine unaffected members of this family showed that the underlying locus maps to a 6.4 cM interval on chromosome 7q36, between EN2 and D7S2423, a region to which a locus for preaxial polydactyly and triphalangeal thumb-polysyndactyly has previously been mapped. Our findings expand the range of phenotypes associated with this locus to include total soft tissue syndactyly and sternal deformity, and suggest that F syndrome may be another manifestation of the same genetic entity. In mice, ectopic expression of the gene Sonic hedgehog (Shh) in limb buds and lateral plate mesoderm during development causes preaxial polydactyly and sternal defects respectively, suggesting that misregulation of SHH may underlie the unusual combination of abnormalities in this family. A recently proposed candidate gene for 7q36 linked preaxial polydactyly is LMBR1, encoding a novel transmembrane receptor which may be an upstream regulator of SHH.

Renal venous thrombosis with calcification and preservation of renal function

Two neonates were found on US to have branching linear calcification in the renal parenchyma, right sided in one and bilateral in the other. CT confirmed the presence of branching calcification in the kidneys and demonstrated calcified thrombus in the inferior vena cava in both babies. Antenatal detection of adrenal haemorrhage in one baby and presence of calcification at the age of 3 days in the other indicate that thrombosis probably occurred before birth. The kidneys remained normal in size, and uptake of 99mTc-labelled dimercaptosuccinic acid (99mTc-DMSA) was normal on follow-up examination. The presence of branching calcification and normal renal size probably indicates good prognosis for renal function in neonates in whom renal venous thrombosis is found and may indicate prenatal thrombosis.

Treatment of oesophageal strictures in children: a comparison of fluoroscopically guided balloon dilatation with surgical bouginage

PURPOSE

To compare the technical feasibility and procedural complications of fluoroscopically guided balloon dilatation with conventional surgical bouginage for the treatment of oesophageal strictures in children.

MATERIALS AND METHODS

A retrospective analysis of 125 balloon dilatations in 37 children with oesophageal strictures of varying aetiology. Twenty-four of the 37 children also underwent 88 procedures of surgical bouginage and comparison was made between the methods.

RESULTS

Fluoroscopic balloon dilatation had fewer technical failures (0/125 vs. 4/88, P<0.02) and fewer iatrogenic perforations (2/125 vs. 5/88 P = 0.1) than surgical bouginage.

CONCLUSION

Fluoroscopically guided balloon dilatation is safer and has fewer technical failures than surgical bouginage and should be considered the first line of treatment for oesophageal strictures in children.

Survey of intussusception reduction in England, Scotland and Wales: how and why we could do better

Britton, I. and Wilkinson, A. G. (2000). Clinical Radiology55, 984-985.

Children of renal transplant recipient mothers

OBJECTIVE

To assess the current physical status and developmental outcome of children born to mothers following renal transplantation.

METHODOLOGY

A cross-sectional prevalence survey of 48 children born to 34 women transplanted at a single centre from 1971 to 1992 was performed. Data on maternal renal disease, immunosuppression, pregnancy, delivery and child development were collected using hospital records and parental questionnaire. Children underwent physical examination, urinalysis and urinary tract ultrasound examination (US).

RESULTS

Maternal renal failure was due to reflux nephropathy/chronic pyelonephritis (16), chronic glomerulonephritis (eight) and other causes (10). All mothers received prednisolone immunosuppression, as sole therapy (one), as part of triple therapy (one). Sixteen (47%) received azathioprine/prednisolone and 16 (47%) cyclosporin/prednisolone. Twenty-three girls and 25 boys aged 9 months to 18 years were studied (median age 5.2 years); 27/48 (56%) were born prematurely, 21/48 (44%) with birthweight (BW) < 2500 g 21/48 (44%) were small for gestation (BW < 10th centile). General health and physical assessment were unremarkable in 45/48 (94%) and 41/43 (95%), respectively. Development was considered normal in 47/48 (98%). Four of 40 (10%) had urinary tract abnormalities on US.

CONCLUSIONS

Despite a high incidence of preterm delivery, low birth weight, intrauterine growth retardation and urinary tract abnormalities, the overall outcome for children of renal transplant recipient mothers is good.

Ultrasound features of intussusception predicting outcome of air enema

OBJECTIVE

To examine features identified on US which predict success or failure of air-enema reduction of intussusception.

MATERIALS AND METHODS

A retrospective study of 117 consecutive episodes of intussusception, presenting for US over a 6-year period. The specific features examined were: free fluid within the peritoneum, small-bowel obstruction, colonic wall thickness, and fluid trapped between the colon and the intussusceptum.

RESULTS

The overall reduction rate, irrespective of US features, over the 6-year period was 72 %. Reduction rates were significantly higher with the absence of free fluid, trapped fluid, or small-bowel obstruction (93 %). The presence of trapped fluid predicted an unfavourable outcome, with a significantly lower success rate (25 %). Colonic wall thickness did not predict outcome; in successful reductions, mean wall thickness was 7.2 mm and in failed reductions 7.6 mm.

CONCLUSIONS

Where free fluid, small-bowel obstruction, and trapped fluid are absent, almost 100 % success with air-enema reduction should be achievable. Where trapped fluid is present, air enema should be performed cautiously to avoid perforation caused by overvigorous attempts at pneumatic reduction of an incarcerated intussusception.

Separation of renal fragments by a urinoma after renal trauma: percutaneous drainage accelerates healing

BACKGROUND

Two boys suffered blunt abdominal trauma resulting in renal injury. In both cases the damaged kidney was fractured through its mid-portion, and the upper and lower fragments of the kidney became widely separated by a urinoma.

MATERIALS AND METHODS

US-guided drainage of the urinoma resulted in immediate apposition of the renal fragments. The drains were left on free drainage by gravity for 1 week before removal.

RESULTS

The urinomas did not reaccumulate and follow-up DMSA scans showed good residual function.

CONCLUSION

We suggest that drainage of urinomas that separate renal fragments should be considered since this may accelerate healing and help preserve renal function.

CT-guided 14-G cutting needle lung biopsy in children: safe and effective

CT-guided percutaneous lung biopsy was performed in children with chronic respiratory disease to obtain samples for histological examination. An automatic cutting device with a 14-G needle was used with one or two cores obtained in each procedure. Seven procedures were performed in six children, mostly with local anaesthesia. Adequate tissue was obtained in all cases. Although a small pneumothorax and/or haemothorax occurred in most procedures, these were usually visible only on CT and did not require active management. A larger pneumothorax in one child also resolved with conservative management. Percutaneous CT-guided 14-G automatic cutting-needle biopsy of lung parenchyma in children is a minimally invasive alternative to open-lung biopsy with no complications in our series.

Two sisters with prenatal growth failure, disproportionate short stature, and feeding difficulties

A familial short stature syndrome is described in two sisters. Clinical features include severe pre- and post-natal growth failure, stridor, feeding difficulties in the first 2 years requiring nasogastric feeding and facial dysmorphism reminiscent of Three M syndrome. Intellectual function is normal. Skeletal surveys show short long bones, small square iliac bones, short femoral necks and vertebral bodies which are short in the antero-posterior diameter with narrowing of the interpedicular distance inferiorly.

Spondylocostal dysostosis associated with a 46, XX,+15,dic(6;15)(q25;q11.2) translocation

We describe a female neonate with spondylocostal dysostosis and a translocation resulting in monosomy for the region 6q25-->qter and trisomy for the region 15q11.1-->pter. The finding of a Mendelian disorder with a chromosomal abnormality may help in the localization of the gene(s) involved in this disease.

Paternal uniparental disomy for chromosome 6 causes transient neonatal diabetes

We report an infant with intrauterine growth retardation and transient neonatal diabetes who has paternal uniparental disomy for chromosome 6. The infant was not dysmorphic and had no congenital anomalies. To our knowledge, this is the third case of paternal uniparental disomy occurring in an infant with transient neonatal diabetes, thus confirming the association.

Pneumatic dilatation in childhood cardio-achalasia

Three boys with achalasia of the cardia were treated with balloon dilatation, with relief of obstruction and weight gain in all cases. Symptoms recurred in one patient, who then underwent myotomy rather than further dilatation. We recommend dilatation as the primary procedure in childhood achalasia.

Radiological features of fungal typhlitis complicating acute lymphoblastic leukaemia

We report the radiological features of fungal typhlitis, a complication of acute lymphoblastic leukaemia, in a child. Colonic dilatation, intramural gas and a tumour-like filling defect in the caecum were demonstrated on ultrasound and contrast enema.

Balloon dilatation of the pelviureteric junction in children: early experience and pitfalls

Early experience with minimally invasive procedures performed on children with pelviureteric junction obstruction is described. Balloon dilatation of the pelviureteric junction was performed in children aged between 5 months and 10 years. Ten procedures were performed in nine children, six for pelviureteric junction obstruction and four for stricture following surgical pyeloplasty. In none of the cases was a stent inserted following the procedure. In two cases the procedure was performed by antegrade approach following nephrostomy and in eight cases by retrograde approach following cystoscopy. In four cases the procedure was successful with relief of symptoms and/or improvement in radiological appearance, in three cases the radiological appearance was unchanged and in three cases the procedure resulted in complete obstruction of the pelviureteric junction requiring surgical intervention. Two of the retrograde procedures resulted in vesicoureteric junction obstruction, one requiring reimplantation and the other nephrectomy. We recommend the antegrade approach to avoid trauma to the vesicoureteric junction, and our results suggest that stenting is necessary to prevent early obstruction.

Long-term follow up to determine the prognostic value of imaging after urinary tract infections. Part 2: Scarring

Long term follow up of children with urinary tract infections, in whom imaging investigations were performed at presentation, has been used to identify features that distinguish those at greatest risk of progressive renal damage. No single investigation at presentation was able to predict subsequent deterioration but, by employing a combination of imaging investigations, it was possible to separate groups with high or low probability of progressive damage. In the low risk group the incidence of progressive damage was 0.2% (95% confidence interval (CI) 0 to 1.3%). The combination of both scarring and reflux at presentation, or one only of these but accompanied by subsequent documented urinary tract infection, was associated with a 17-fold (95% CI 2.5 to 118) increase in the relative risk of progressive renal damage compared with children without these features. The recommended combination of investigations at presentation for girls of any age and boys over 1 year is ultrasound and dimercaptosuccinic acid (DMSA) scintigraphy in all, to detect both scarring and significant structural abnormalities, renography in children with dilatation of any part of the urinary tract on ultrasound, to distinguish dilatation from obstruction, and an isotope voiding study in all who have acquired bladder control. This gives the best separation between those at high and those at low risk of progressive damage with least radiation dose and lowest rate of instrumentation. Micturating cystourethrography (MCU) should be restricted to girls who have not acquired bladder control, unless there is reason to suspect a significant structural abnormality such as urethral valves. A single non-febrile urinary tract infection that responds promptly to treatment is not a justification for performing MCU in boys under 1 year or in children of any age with bladder control. No case can be made for any abbreviated schedule of investigation. These risk factors should be taken into account when designing follow up protocols.

Long-term follow up to determine the prognostic value of imaging after urinary tract infections. Part 1: Reflux

In 3646 children with at least one confirmed urinary tract infection the prevalence of vesicoureteric reflux at presentation was correlated with progressive renal damage during follow up of not less than two and up to 16 years. Reflux was not demonstrated either at presentation or at any subsequent time in almost one half of the children who suffered progressive renal damage and was not a risk factor for progressive renal damage in boys under 1 year. It was an important risk factor in boys over 1 year and in girls of any age. The risk of progressive renal damage in children in whom micturating cystourethrography (MCU) did not reveal vesicoureteric reflux was substantially greater than in those who indirect isotope voiding study (IVS) did not show reflux. The risk of deterioration for those in whom reflux was demonstrated was similar for both techniques. This discrepancy indicates an appreciably higher false negative rate for the MCU than the IVS. Dilatation of the renal pelvis detected by ultrasound was associated with a significantly increased risk of progressive damage only when associated with reflux, but most children with progressive damage did not have a dilated collecting system at presentation.

Case report: calculus in the seminal vesicle

Calculus of the seminal vesicle has not been described in children previously. A case is described in which a seminal vesicle calculus was mistakenly thought to lie within the bladder leading to fruitless cystolithotomy.

Is pre-operative imaging of the urinary tract worthwhile in the assessment of prostatism?

The reports of routine pre-operative imaging investigations performed on patients presenting with symptoms of uncomplicated benign prostatic hypertrophy were compared with management decisions and clinical outcome. In 175 patients with prostatism no urological abnormality which altered management was discovered on plain films of the abdomen and pelvis and ultrasound of the urinary tract which were performed routinely. Post-micturition residual volume (PMRV), estimated by ultrasound, was compared with the maximum urine flow rate (Q max) in 57 patients. PMRV showed negative correlation with Q max. Both high PMRV and low Q max were associated with the urologist's decision to operate, but multiple logistic regression revealed that ultrasound residual volume was not a significant predictor of operation when adjusted for Q max. Urologists in this hospital therefore use flow rates as the primary indication of the need to operate. We suggest that no routine pre-operative imaging need be performed in patients presenting with prostatism.

Survey of urological centres and review of current practice in the pre-operative assessment of prostatism

A survey of 24 urological centres has shown a wide variation in the routine pre-operative assessment of patients being considered for prostatectomy. Imaging of the urinary tract by intravenous urography (IVU) or ultrasound (US) is performed in 21/24 centres (79%) and plain films in 16/24 (67%). Post-micturition residual volume (PMRV) is estimated quantitatively in 10/24 centers (42%). Although there is little agreement on what constitutes a significant PMRV, a large PMRV leads to increased likelihood of operation, and earlier operation. Peak urine flow rate (Q max) is measured in 19/24 centres (79%). The significance of these findings is discussed.

The influence of needle size and other factors on the incidence of adverse effects caused by myelography

A randomized prospective trial of 26 G versus 22 G spinal needles was performed in 284 consecutive patients referred for myelography, during which contrast medium was introduced by lumbar puncture. Use of the fine (26 G) gauge needle resulted in a significant decrease in moderately or severely painful needle placements and moderate, severe or postural headaches following myelography. The incidence of other side effects was not significantly influenced by needle size. The incidence of headaches and other side effects was significantly higher in female patients. Back pain, the commonest side effect, was significantly more common in patients who had normal lumbar myelograms than in those in whom lumbar root compression was demonstrated. The incidence of neck stiffness was significantly higher following cervicothoracic myelograms than lumbar myelograms but there was no significant difference in the incidence of other side effects. The use of 4.5 g instead of 3.0 g of iodine resulted in no increase in symptoms. The experience of the operator had no significant effect on the incidence of side effects. Some side effects of myelography appear to be due mainly to cerebrospinal fluid leakage at the site of puncture and are strongly influenced by psychological factors.

99Tcm-MAG3: in vitro stability and in vivo behaviour at different times after preparation

A kit for preparing technetium-99m mercaptoacetyltriglycine (99Tcm-MAG3), a new radiopharmaceutical for gamma camera renography, is available commercially. A drawback to the use of this kit is the recommended 1h expiry for 99Tcm-MAG3. This short expiry is a consequence of the possible growth of an impurity which undergoes hepatobiliary excretion and might interfere with renal imaging. Radiochemical purity of 99Tcm-MAG3 was measured by high performance liquid chromatography at 0, 1 and 6 h after preparation and was found to be consistently greater than 95. 99Tcm-MAG3 was shown to contain five impurities, one of which increased from 0.5% to 1% over 6 h. Dilution of 99Tcm-MAG3 eliminated this effect. A two-part clinical study was undertaken. For Part I, 99Tcm-MAG3 was prepared at 400 MBq/4 ml. For Part II, 99Tcm-MAG3 was prepared at 1 GBq/4 ml then subdivided and diluted to give single doses of 175 MBq/2.5 ml. In both parts, 10 patients were injected within 1 h after preparation and 10 were injected 5-6 h after preparation. From gamma camera images of the abdomen acquired 30 min after injection, the % injected 99Tcm in gall bladder and liver were calculated. In both parts, the % injected 99Tcm in gall-bladders and livers of the 1 h group were compared with those in the 5-6 h group and not found significantly different (p greater than 0.05). In conclusion, 99Tcm-MAG3 prepared according to the methods described, can be used up to 6 h after preparation.

Complete laryngotracheoesophageal cleft: CT diagnosis and associated abnormalities

A case of complete laryngotracheoesophageal cleft is described in a male infant in which bronchoscopy could not be performed due to a narrow tracheal orifice. CT scan of the thorax demonstrated a common tracheal and oesophageal lumen extending inferiorly to the carina, with hypoplasia of the right lung and cardiac dextroposition. Contrast studies demonstrated a hypoplastic intrathoracic stomach. Chromosome analysis revealed satellites on the Y chromosome with karyotype 46XYqs.

Recurrent pneumothorax: an unusual presentation of malignant mesothelioma

Malignant mesothelioma is an uncommon condition with about 250 new cases each year in the United Kingdom, most of which present with dyspnoea due to pleural effusion or chest pain. We report a case of malignant mesothelioma which presented as recurrent pneumothorax.

Two cases of Poncet's disease

Poncet's disease is a rare polyarthritis occurring in patients with tuberculous infections. We describe two cases of polyarthritis, one secondary to pulmonary tuberculosis, the other secondary to tuberculous infection of the elbow joint. In both cases the arthritis rapidly subsided with chemotherapy.

Potassium transfer from brain to blood during sustained hyponatraemia in the newborn calf

The effect of dilutional hyponatraemia on cerebral blood flow and oxygen consumption, and net transfer of K+ to the circulation from brain tissue drained by the sagittal sinus was investigated in anaesthetized calves. Cerebral blood flow decreased, and net transfer of K+ to the circulation increased during hyponatraemia.