Diagnostic accuracy of DXA compared to conventional spine radiographs for the detection of vertebral fractures in children.

OBJECTIVES: In children, radiography is performed to diagnose vertebral fractures and dual energy x-ray absorptiometry (DXA) to assess bone density. In adults, DXA assesses both. We aimed to establish whether DXA can replace spine radiographs in assessment of paediatric vertebral fractures. METHODS: Prospectively, lateral spine radiographs and lateral spine DXA of 250 children performed on the same day were independently scored by three radiologists using the simplified algorithm-based qualitative technique and blinded to results of the other modality. Consensus radiograph read and second read of 100 random images were performed. Diagnostic accuracy, inter/intraobserver and intermodality agreements, patient/carer experience and radiation dose were assessed. RESULTS: Average sensitivity and specificity (95 % confidence interval) in diagnosing one or more vertebral fractures requiring treatment was 70 % (58-82 %) and 97 % (94-100 %) respectively for DXA and 74 % (55-93 %) and 96 % (95-98 %) for radiographs. Fleiss' kappa for interobserver and average kappa for intraobserver reliability were 0.371 and 0.631 respectively for DXA and 0.418 and 0.621 for radiographs. Average effective dose was 41.9 µSv for DXA and 232.7 µSv for radiographs. Image quality was similar. CONCLUSION: Given comparable image quality and non-inferior diagnostic accuracy, lateral spine DXA should replace conventional radiographs for assessment of vertebral fractures in children. KEY POINTS: • Vertebral fracture diagnostic accuracy of lateral spine DXA is non-inferior to radiographs. • The rate of unreadable vertebrae for DXA is lower than for radiographs. • Effective dose of DXA is significantly lower than radiographs. • Children prefer DXA to radiographs. • Given the above, DXA should replace radiographs for paediatric vertebral fracture assessment.

Evaluation of a semi-automated software program for the identification of vertebral fractures in children.

AIM: To assess observer reliability and diagnostic accuracy in children, of a semi-automated six-point technique developed for vertebral fracture (VF) diagnosis in adults, which records percentage loss of vertebral body height. MATERIALS AND METHODS: Using a semi-automated software program, five observers independently assessed T4 to L4 from the lateral spine radiographs of 137 children and adolescents for VF. A previous consensus read by three paediatric radiologists using a simplified algorithm-based qualitative technique (i.e., no software involved) served as the reference standard. RESULTS: Of a total of 1,781 vertebrae, 1,187 (67%) were adequately visualised according to three or more observers. Interobserver agreement in vertebral readability for each vertebral level for five observers ranged from 0.05 to 0.47 (95% CI: -0.19, 0.76). Intra-observer agreement using the intraclass correlation coefficient (ICC) ranged from 0.25 to 0.61. The overall sensitivity and specificity were 18% (95% CI: 14-22) and 97% (95% CI: 97-98), respectively. CONCLUSION: In contrast to adults, the six-point technique assessing anterior, middle, and posterior vertebral height ratios is neither satisfactorily reliable nor sensitive for VF diagnosis in children. Training of the software on paediatric images is required in order to develop a paediatric standard that incorporates not only specific vertebral body height ratios but also the age-related physiological changes in vertebral shape that occur throughout childhood.

Diagnosis of vertebral fractures in children: is a simplified algorithm-based qualitative technique reliable?

BACKGROUND: Identification of osteoporotic vertebral fractures allows treatment opportunity reducing future risk. There is no agreed standardised method for diagnosing paediatric vertebral fractures. OBJECTIVE: To evaluate the precision of a modified adult algorithm-based qualitative (ABQ) technique, applicable to children with primary or secondary osteoporosis. MATERIALS AND METHODS: Three radiologists independently assessed lateral spine radiographs of 50 children with suspected reduction in bone mineral density using a modified ABQ scoring system and following simplification to include only clinically relevant parameters, a simplified ABQ score. A final consensus of all observers using simplified ABQ was performed as a reference standard for fracture characterisation. Kappa was calculated for interobserver agreement of the components of both scoring systems and intraobserver agreement of simplified ABQ based on a second read of 29 randomly selected images. RESULTS: Interobserver Kappa for modified ABQ scoring for fracture detection, severity and shape ranged from 0.34 to 0.49 Kappa for abnormal endplate and position assessment was 0.27 to 0.38. Inter- and intraobserver Kappa for simplified ABQ scoring for fracture detection and grade ranged from 0.37 to 0.46 and 0.45 to 0.56, respectively. Inter- and intraobserver Kappa for affected endplate ranged from 0.31 to 0.41 and 0.45 to 0.51, respectively. Subjectively, observers' felt simplified ABQ was easier and less time-consuming. CONCLUSION: Observer reliability of modified and simplified ABQ was similar, with slight to moderate agreement for fracture detection and grade/severity. Due to subjective preference for simplified ABQ, we suggest its use as a semi-objective measure of diagnosing paediatric vertebral fractures.

Is intravenous urography necessary in the assessment of renal duplex system in children?

OBJECTIVE: Partial or complete duplication of the renal tract may be an incidental finding or may be associated with significant pathology. Accurate assessment is not always easy. This retrospective review was undertaken to determine whether intravenous urography (IVU) in combination with a DMSA renal scan provides significant additional information. PATIENTS AND METHODS: Eighteen patients referred to our imaging department with a provisional diagnosis on ultrasound of renal tract duplication during a three year period were identified by searching the radiological computer files. The presenting features were urinary infection (13), abdominal pain (3) and abnormal antenatal sonography (2). RESULTS: Four patients were found not to have renal duplication. There was concordance between the IVU and DMSA scan in seven. Additional clinically relevant information was obtained in three cases. A false negative result from the DMSA scan was found in four children and a false positive result in three. CONCLUSION: In a significant number of cases of possible renal tract duplication, additional relevant information can be obtained from an IVU. Patient distress is minimised by combining the IVU and DMSA in one single episode of venous access. Review of the radiological images during the investigation allows minimisation of radiation dosage.

The 4 year outcome following the demonstration of bilateral renal pelvic dilatation on pre-natal renal ultrasound.

There is little in the literature regarding long-term prognosis in cases of fetal pyelectasis and calyceal dilatation. The aim of this study was to correlate antenatal ultrasound findings with outcome in a large group of children, most of whom had routine antenatal mid-trimester scans. 75 babies with bilateral pyelectasis and calyceal dilatation in the pre-natal period and complete radiological and clinical data were identified over a 3 year period. Pre-natal ultrasound was correlated with results of post-natal investigation and the frequency of post-natal surgery was established. Follow-up was documented to discharge or to at least 4 years of age. Prognosis was related to the degree of pelvic dilatation, but neonatal morbidity was much more likely to be associated with pre-natal calyceal dilatation and/or hydroureter. 68% (51 of 75) of babies had insignificant abnormalities on post-natal investigation, defined as either transient fetal pyelectasis and calyceal dilatation, extrarenal pelves, or transient neonatal pyelectasis and calyceal dilatation. Five babies died in the neonatal period, all classified as either moderate or severe disease. Of the surviving 70 cases (93.3%), 27% had renal anomalies that required treatment by prophylactic antibiotics or surgery. The remaining babies were conservatively managed and followed as outpatients. One child required transplantation and a further two had a severe degree of chronic renal failure by the age of 4 years. These data will be of value in prospective counselling.

Investigating febrile UTI in infants: is a cystogram necessary?

OBJECTIVE: Current imaging recommendations for investigating any infantile febrile urinary tract infection (UTI) are ultrasound scan (US), micturating cystourethrogram (MCUG) and dimercaptosuccinic acid (DMSA) scan. The aim of this retrospective cohort study was to determine the need and indications for MCUG in the investigation of a first febrile infantile UTI, as doubts have been raised over its benefit. PATIENTS AND METHODS: Information on 427 infants who had undergone US, MCUG and DMSA following a first febrile UTI was prospectively recorded. The infants were divided into two groups: A (354) with normal renal US and B (73) with abnormal US. DMSA findings were correlated with findings on MCUG. Main outcome measures were incidence of recurrent UTIs, change in management or intervention as a result of MCUG, and outcome at discharge. RESULTS: Only 21/354 (6%) infants in Group A had both scarring on DMSA and vesicoureteric reflux (VUR), predominantly low-grade on MCUG. In Group B (abnormal US), 23/73 (32%) had scarring on DMSA and vesicoureteric reflux, predominantly high grade on MCUG. Of the infants with non-scarred kidneys, 73% had dilating reflux. Successful conservative treatment was performed in 423 infants, and 4 infants in Group B required surgery. CONCLUSION: We recommend US and DMSA in all infantile febrile UTI cases. Where US is normal, MCUG should be reserved for those cases with abnormal DMSA. Where US is abnormal, MCUG should be performed irrespective of findings on DMSA scan. A randomized prospective study is necessary to evaluate this further.

Sciatica in degenerative spondylolisthesis of the lumbar spine.

Intraspinal synovial cysts are an uncommon but well recognised cause of backache and sciatica, and should be considered in patients, in particular with degenerative spondylolisthesis, who are symptomatic. MRI is the initial investigation of choice. If there is any doubt as to the diagnosis, CT with or without facet joint arthrography is helpful.

Large adrenal cysts in teenage girls: diagnosis and management.

Large adrenal cysts usually occur in the fifth and sixth decades of a patient's life but are rare in the first two decades. This paper presents the clinical, cross-sectional imaging, surgical, pathological and follow-up data of three teenage girls with large adrenal cysts. Two had vague upper abdominal pain and, in the other, the cyst was found incidentally. The cysts were surgically removed in two patients, while in the third, follow-up imaging has shown no change in the cyst over a 4-year period, suggesting that conservative management is a reasonable option.