Observer variation in the sonographic measurement of optic nerve sheath diameter in normal adults.

AIM: To quantify the observer variation in the sonographic measurement of optic nerve sheath diameter (ONSD) in normal adults. MATERIALS AND METHODS: Sixty-seven normal adult volunteers underwent ultrasound examination of each eye by three independent observers using a 7 MHz sector probe. Three measurements were made of each eye by each observer and a mean value calculated for each eye. Median and 5th-95th centile values for both intra- and inter-observer variation were calculated for the three observers. RESULTS: The median intra-observer variation was +/-0.1 mm, with 5th-95th centile values of +/-0-0.4 mm. The median inter-observer variation was +/-0.2-0.3 mm, with 5th-95th centile values of +/-0-0.7 mm. Careful review of examination technique by the three observers after the first 17 examinations was shown to reduce both intra- and inter-observer variation. CONCLUSION: The sonographic measurement of ONSD is a readily learned, reproducible technique with low intra- and inter-observer variation. The average inter-observer variation (+/-0.2 mm) is comparable to the inherent variability of the ultrasound machine. The importance of standardisation of examination technique is stressed.

Ultrasound of the thyroid gland in the newborn: normative data.

OBJECTIVE: To establish reference ranges for thyroid length, breadth, depth, and volume in healthy term Scottish infants. DESIGN: Prospective observational study of 100 (49 male) neonates. Length, breadth, and depth were measured, and the volume of each lobe was calculated using the formula for a prolate ellipsoid (volume = length x breadth x depth x pi/6). RESULTS: All measurements showed gaussian distribution, with no significant differences between the right and the left lobes. Values (mean (SD) range) were: length (cm), 1.94 (0.24) 0.9-2.5; breadth (cm), 0.88 (0.16) 0.5-1.4; depth (cm), 0.96 (0.17) 0.6-2.0; volume (ml), 0.81 (0.24) 0.3-1.7; combined volume (ml), 1.62 (0.41) 0.7-3.3. Although there was no difference in mean volume between right and left lobes, there was considerable variation (-0.8 to + 0.7 ml) between the two lobes in individual babies. CONCLUSIONS: Both lobes should be measured to give a combined volume. Our findings provide a reference against which thyroid hypoplasia or goitre can be evaluated.

Measurement of optic nerve sheath diameter by ultrasound: a means of detecting acute raised intracranial pressure in hydrocephalus.

AIM: To evaluate the utility of measuring the optic nerve sheath diameter in children with shunted hydrocephalus, suspected of having raised intracranial pressure. METHODS: 23 children with shunted hydrocephalus were examined, six had well controlled ICP, 17 however manifested symptoms suggestive of intracranial hypertension. A clinical history was taken from all patients and their parents or carers. The shunt valve was examined clinically, and signs of raised intracranial pressure were sought. Ultrasound examination was performed in both eyes to measure the optic nerve sheath diameters 3 mm behind the globe. These measurements were compared with control data obtained from 102 children who attended the radiology department for unrelated renal ultrasound examination. RESULTS: Control data suggested that the upper limit of normal for optic nerve sheath diameter is 4.5 mm (measured 3 mm behind the globe) in patients over 1 year of age, and 4.0 mm in children less than 1 year of age. Those patients with functioning ventriculoperitoneal shunts had a mean optic nerve sheath diameter of 2.9 (SD 0.5) mm; those with raised intracranial pressure had a mean optic nerve sheath diameter of 5.6 (0.6) mm (p<0.0001). These results confirm that optic nerve sheath diameters in excess of the control data are strongly suggestive of raised intracranial pressure. CONCLUSION: The evaluation of the optic nerve sheath diameter is a simple non-invasive procedure, which is a potentially useful tool in the assessment and monitoring of children with hydrocephalus suspected of having raised intracranial pressure.

Phenotype, ovarian function, and growth in patients with 45,X/47,XXX Turner mosaicism: implications for prenatal counseling and estrogen therapy at puberty.

OBJECTIVE: Our objective was to determine whether girls with the rare Tur-ner 45,X/47,XXX mosaic karyotype are less severely affected than girls with 2 commoner karyotypes. STUDY DESIGN: We evaluated growth status, phenotype, and ovarian function in 7 girls with 45,X/47,XXX mosaicism, age-matching each with 2 girls with 45,X and 1 with 45,X/46,Xi(X)(q10) karyotypes. RESULTS: For the index, 45,X, and 45,X/46,Xi(X)(q10) groups, respectively, the median/mean height SD score at the start of growth hormone therapy/comparable age was -2.0 (-1.2), -2.3 (-2.4), and -2.6 (-2.6), cardiac anomalies were identified in 0 of 7, 4 of 14, and 1 of 7, renal abnormalities in 0 of 7, 4 of 14, and 3 of 7, middle ear problems in 2 of 7, 11 of 14, and 4 of 7, and special educational needs in 0 of 7, 3 of 14, and 1 of 7. Complete spontaneous puberty with menarche was seen in all but 1 girl older than 12 years in the index group compared with only 1 girl in the comparison groups. Ovarian tissue was identified in 6 of 7, 0 of 14, and 1 of 7 girls, and the mean follicle-stimulating hormone was 6, 25, and 21 U/L, respectively. CONCLUSION: Girls with 45,X/47,XXX karyotype are mildly affected, with good preservation of ovarian function. This result has important implications for prenatal counseling and the need for estrogen therapy at puberty.

A new case of Myhre syndrome.

Myhre Syndrome is a rare condition associated with mental retardation, short stature, generalized muscle hypertrophy, cardiac defects and a distinct facial appearance. There have only been five reported cases and we now present a sixth, together with a review of the clinical features of this syndrome.

Liver disease does not affect lipolysis as measured with the 13C-mixed triacylglycerol breath test in children with cystic fibrosis.

BACKGROUND: Liver disease associated with cystic fibrosis may not only limit the solubilisation and absorption of the products of fat digestion, but also may depress the activity of pancreatic lipase. The purpose of this study was to measure the effect of liver disease on triacylglycerol lipolysis using the 13C-mixed triacylglycerol breath test. METHODS: Forty children with cystic fibrosis took 13C-mixed triacylglycerol with a standard breakfast and the child's normal pancreatic enzyme replacement therapy. Breath samples were collected before and every 30 minutes after ingestion for 6 hours. The cumulative percentage dose of 13C recovered at 6 hours was calculated from sequential measurements of 13C enrichment of breath CO2, measured by isotope ratio mass spectrometry. Liver abnormalities and portal hypertension were defined by ultrasound scan and clinical examination. RESULTS: Twenty-four children had liver abnormalities, including 5 with portal hypertension. No difference was found between cumulative percentage dose of 13C recovered at 6 hours in 16 children with no liver abnormality (mean, 21.4%+/-11.1%), 19 children with liver abnormalities (22.2%+/-10.0%) and 5 children with portal hypertension (20.9%+/-7.1%). CONCLUSION: Intestinal lipolysis is not reduced in cystic fibrosis liver disease when measured using the 13C mixed triacylglycerol breath test. These findings affirm the test's use as an indirect measure of fat digestion that is not affected by inadequate intraluminal bile salts or liver disease.

Transorbital optic nerve sheath ultrasonography in normal children.

AIM: Early diagnosis of acute intracranial hypertension is essential to enable prompt, optimal treatment. The optic nerve sheath diameter (ONSD) is increased in raised ICP and there has been recent interest in the use of ultrasound to diagnose and indirectly monitor raised ICP by ONSD measurement. The advantages of the technique include its non-invasiveness, wide availability, portability, low cost and the absence of ionizing radiation. This prospective study was designed to establish the range of normal values for ONSD in infants and children up to 15 years of age. PATIENTS AND METHODS: One hundred and two children attending the hospital for other reasons were recruited to the study. Three measurements of the ONSD were taken for each eye, 3 mm behind the optic nerve head using a 7 MHz sector probe. RESULTS: The range for ONSD was 2.1-4.3 mm, mean 3.08 (SD 0.36). There were no significant differences on ONSD measurement between boys and girls (P = 0.59) or between right and left eyes (P=0.66). When the data were grouped and analysed, a correlation between increasing age and increasing ONSD was seen (r2=0.48), with the greatest increase occurring in the first 2 months of life. CONCLUSION: Using the technique described here, our results suggest that an ONSD of greater than 4 mm in infants less than 1 year, and 45 mm or greater in older children, should be regarded as abnormal.

Accuracy of clean-catch urine collection in infancy.

OBJECTIVE: To compare the accuracy of cultures of urine obtained by clean-catch urine (CCU) collection and suprapubic aspiration (SPA) in infants. DESIGN: Prospective case series undertaken in a pediatric teaching hospital and associated neonatal unit. Fifty-eight paired urine cultures (CCU collection and SPA) were obtained from 49 infants with suspected urinary tract infection. The primary outcome measure was the presence or absence of significant bacteriuria on both CCU collection and SPA; secondary outcome measures were the success of SPA with ultrasound guidance compared with aspiration without ultrasound guidance. Statistical analysis was done by using a chi(2) test. RESULTS: A false-positive rate of 5% and a false-negative rate of 12% were recorded. Sensitivity was 88.9% (95% CI 65.3-98.6), and specificity was 95.0% (95 CI% 83.1-99. 4). Ultrasound-assisted SPA was successful in 26 of 28 patients (93%) and in 13 of 21 patients (62%) when SPA was performed without ultrasound (chi(2) = 7.08, P =.008). CONCLUSIONS: We conclude that there is a good association in results of culture of urine obtained by CCU collection and SPA and would encourage the use of the CCU technique.

The evolution of liver disease in cystic fibrosis.

OBJECTIVES: To describe prospectively the evolution of liver abnormalities in cystic fibrosis (CF), and to assess their impact on nutritional status. STUDY DESIGN: 124 children (61 boys) with CF (median age, 5.4 years; range, 0.1-13.9) were followed longitudinally for a median of four years. Annual clinical examination, biochemistry, and ultrasound assessment were performed. Chrispin-Norman score, anthropometry, and bacterial colonisation of airway secretions were measured at each assessment. RESULTS: At initial assessment, 45% of the patients had no liver abnormalities, 42% had biochemical abnormality, 35% ultrasound abnormality, and 6% had clinical abnormality of the liver. In this cross sectional analysis, abnormal biochemistry was present in 40% of children with ultrasound or clinical abnormalities, but when longitudinal follow up data were analysed, abnormal biochemistry preceded or coincided with abnormal ultrasound or clinical hepatosplenomegaly in three quarters of 53 children developing new abnormalities. Eighty four of 124 children (68%) showed ultrasound or clinical evidence of liver abnormality at some point during the four years of follow up. No association was found between liver disease and nutritional status. CONCLUSIONS: Hepatic abnormality was common in this group of children with CF, was often predicted by intermittent biochemical abnormalities, and was not associated with deterioration in nutritional status.

The acute paediatric scrotum: the role of colour doppler ultrasound.

Combined grey scale ultrasound and colour Doppler imaging of the acute paediatric scrotum provides a non-invasive means of assessing the structure and perfusion of the testis. Colour flow ultrasound is a sensitive and specific diagnostic tool for differentiating ischaemic pathology (in which blood flow rate is reduced) from inflammatory disease in which it is commonly increased. Using this technique the number of unnecessary surgical explorations of the scrotum can be reduced. The differential diagnosis of acute testicular pathology and the imaging characteristics of each disorder are described. Close collaboration between paediatric surgeons and radiologists is required to determine the optimal clinical and investigational strategy for each child.

Efficacy of Zoladex LA (goserelin) in the treatment of girls with central precocious or early puberty.

OBJECTIVE: To assess the efficacy of a longer acting preparation of the gonadotrophin releasing hormone (GnRH) analogue goserelin (Zoladex LA, 10.8 mg) in 12 girls with central precocious or early puberty. METHODS: Two girls started treatment de novo; the remainder had been on suppressive treatment for a median duration of 1.5 (range, 0.2-5.6) years. Assessment comprising auxology, pubertal staging, and pelvic ultrasound examination was carried out at weeks 0, 4, 8, 10, and 12 (first cycle) and weeks 8, 10, and 12 (second cycle) to evaluate the required injection frequency. Thereafter, assessment was performed on the day of injection. Zoladex LA was given every 12 weeks unless pubertal progression occurred. RESULTS: Satisfactory control was achieved in eight patients using this regimen, and three patients required more frequent injections. One girl was removed from the study because of clinical progression and extreme mood swings. No serious adverse effects occurred. Mean height velocity during the study period was 4.5 cm/year (range, 3.1-6.6) compared with 6.5 cm/year (range, 3.8-9.6) before treatment in nine patients for whom data were available. CONCLUSIONS: Zoladex LA was effective in controlling precocious puberty in girls when given at intervals of 9-12 weeks and it is recommended that an initial assessment is made eight weeks after beginning treatment.

Comparison of computed tomography and ultrasonographic imaging in the assessment of blunt abdominal trauma in children.

BACKGROUND: Computed tomography (CT) has become established in the assessment of paediatric blunt abdominal trauma. However, advances in diagnostic imaging necessitate reassessment of the role of available diagnostic modalities. METHODS: Experience at a paediatric teaching hospital over a 5-year period was reviewed, with direct comparison of CT against ultrasonographic imaging in 26 children presenting with acute blunt abdominal trauma. RESULTS: Intra-abdominal injury was diagnosed by CT in 23 of 24 patients compared with 21 on ultrasonography, although ultrasonography identified organ-specific injury in only 12 of 24 patients. CT was superior in the assessment of the multiply injured child, and identified spinal and pelvic injuries in three patients. CT augmented plain chest radiography in ten patients with associated thoracic injuries. CONCLUSION: CT is the imaging modality of choice in children with severe abdominal trauma but ultrasonography is a reasonable technique to arouse diagnostic suspicion in less severe injuries or where CT is unavailable or delayed.

An unusual hernia: congenital pericardial effusion associated with liver herniation into the pericardial sac.

To our knowledge there have been only two previous cases of diaphragmatic hernia into the pericardium diagnosed antenatally. We describe our pre- and post-natal radiological findings in such a case, although the final diagnosis eluded us until after delivery.

Pelvic ultrasound measurements in normal girls.

Pelvic ultrasound scans were carried out in 153 normal girls aged between 3 days and 14.9 years, in order to obtain reference data for ovarian volume, uterine length and uterine configuration. The right ovary was significantly larger than the left (by about 17%). Ovarian volume increased exponentially with age, over this age range. No relationship with pubertal stage (independent of age) could be demonstrated. Uterine length decreased from birth to 4 years, before steadily increasing. The fundal-cervical ratio (FCR) decreased initially then increased to lie above 1.0 by 15 years of age. A midline endometrial echo was seen in half of the subjects aged less than 6 months, but otherwise it was not seen before 11.8 years of age or at Tanner stage B2. Smoothed reference centile curves for uterine length, right and left ovarian volume were produced, allowing z scores (or SD scores) to be calculated for each measurement.

Pelvic ultrasound findings in different forms of sexual precocity.

Recently produced reference curves for various ultrasound dimensions were used to retrospectively assess 67 pelvic ultrasound scans carried out at the initial presentation in girls with sexual precocity. At presentation the group with precocious puberty had significantly increased uterine lengths and ovarian volumes compared with the normal population, and a significantly increased fundal-cervical ratio. Ovarian volume was also significantly increased in therlarche and thelarche variant. The fundal-cervical ratio was significantly increased in thelarche variant. There was considerable overlap between individuals with sexual precocity and normal subjects. The ultrasound findings that best discriminated early or precocious puberty from other forms of sexual precocity were the presence of a midline endometrial echo, and a uterine length above the 97th centile for age. An entirely normal pelvic ultrasound at presentation did not rule out the possibility of precocious puberty.

Ultrasound evaluation of the paediatric prostate.

OBJECTIVE: To document the shape, echogenicity and volume range of the normal paediatric prostate on transabdominal ultrasound, and to determine the feasibility of imaging the seminal vesicles and prostatic urethra with transabdominal ultrasound. PATIENTS AND METHODS: Transabdominal ultrasound of the prostate was performed in 36 boys, aged 7 months-13.5 years (mean 7.7 years), with normal prostates. RESULTS: Generally the prostate was hypoechoic, ellipsoidal in shape with a volume range of 0.4-5.2 ml (mean 1.2). The seminal vesicles were demonstrated in 56% of boys but only occasionally could the urethra be visualized. No colour flow was demonstrated within the prostate. CONCLUSION: The paediatric prostate can be easily visualized by transabdominal ultrasound. This technique may be of value in the investigation of incontinence, posterior urethral valves and seminal vesicle pathology, and in the monitoring of prostatic volume in hypogonadal boys.

Useful investigations in a refractory case of 'myositis'.

The diagnosis of polymyositis is made on the basis of clinical features, muscle enzymes, EMG studies and muscle biopsy. Treatment requires corticosteroids often in combination with immunosuppressive agents, and relapse in spite of treatment may render management difficult. The case described below appeared to demonstrate features from which the diagnosis could be made, but in which the almost complete resistance to conventional therapy led to a correct reappraisal of the diagnosis. This illustrates an unusual cause for diagnostic confusion and the value of diagnosis reassessment under such circumstances.

The value of ultrasound in the child with an acute urinary tract infection.

OBJECTIVE: To assess the value of an ultrasound examination in children with a proven urinary tract infection. PATIENTS AND METHODS: The results of renal ultrasound and 99mTc-dimercapto-succinic acid (DMSA) studies were compared in 112 children with a first documented symptomatic Escherichia coli urinary tract infection. RESULTS: Ultrasound was particularly effective in detecting the presence of obstruction, renal swelling and parenchymal change consistent with acute pyelonephritis. However, ultrasound failed to detect half of the kidneys with photon deficient areas on 99mTc DMSA scan and was unreliable in detecting the presence of scarring. CONCLUSION: An ultrasound examination alone should not be relied on in the child with an acute urinary tract infection.

Ultrasound assessment of the contralateral groin in infants with unilateral inguinal hernia.

Sonographic and operative findings in both groins of 23 infants presenting with a unilateral inguinal hernia were compared in a prospective study. Ultrasound accurately confirmed the presence of a hernia on the affected side in all infants but provided no useful additional diagnostic information. Ultrasound examination of the unaffected side was less accurate. Surgical exploration revealed the presence of a patent processus vaginalis (PPV) in 18 cases and its absence in five. Ultrasound was found to be accurate in only 15 out of the 23 cases with four false positive and four false negative results. This yielded an accuracy of 65%, a sensitivity of 78% and a specificity of only 20%. It is concluded that ultrasound cannot at present be used alone to plan the management of the contralateral groin, especially as the majority of children who do have a PPV will never develop an inguinal hernia.