Pediatric radius torus fractures in x-rays-how computer vision could render lateral projections obsolete.

It is an indisputable dogma in extremity radiography to acquire x-ray studies in at least two complementary projections, which is also true for distal radius fractures in children. However, there is cautious hope that computer vision could enable breaking with this tradition in minor injuries, clinically lacking malalignment. We trained three different state-of-the-art convolutional neural networks (CNNs) on a dataset of 2,474 images: 1,237 images were posteroanterior (PA) pediatric wrist radiographs containing isolated distal radius torus fractures, and 1,237 images were normal controls without fractures. The task was to classify images into fractured and non-fractured. In total, 200 previously unseen images (100 per class) served as test set. CNN predictions reached area under the curves (AUCs) up to 98% [95% confidence interval (CI) 96.6%-99.5%], consistently exceeding human expert ratings (mean AUC 93.5%, 95% CI 89.9%-97.2%). Following training on larger data sets CNNs might be able to effectively rule out the presence of a distal radius fracture, enabling to consider foregoing the yet inevitable lateral projection in children. Built into the radiography workflow, such an algorithm could contribute to radiation hygiene and patient comfort.

The influence of brace immobilization on the remodeling potential of thoracolumbar impaction fractures in children and adolescents.

PURPOSE: Different treatment methods including immediate mobilization with or without brace, bed rest or immobilization using thoracolumbosacral orthosis have been applied for stable compression fractures of the pediatric spine. The aim of this study was to evaluate the influence of bracing on the remodeling capacity of pediatric thoracolumbar type A 1.2 impaction fractures. Additionally, the prevalence of pain and functional disabilities were assessed. METHODS: All children treated conservatively between 2000 and 2011 with impaction fractures of the thoracolumbar spine (A 1.2) were included and re-invited for a clinical [including VAS 0-100, Oswestry disability index (ODI)] and radiological follow-up examination. Changes of the sagittal index (SI) at the time of the accident, the latest control visit and at the follow-up examination were analyzed. RESULTS: Seventy-two patients with a mean age of 12 years (1.8-18 years) and a total number of 133 fractured vertebrae were included. The mean SI at the time of injury was 0.76 (range 0.45-0.94, SD 0.08); 34 patients with 67 fractured vertebrae were included in the follow-up examination after a mean of 7.9 years (2.4-13.1 years). The mean SI of the 67 affected vertebrae at follow-up significantly increased to 0.92 (range 0.74-1, SD 0.06). The initial treatment regimen (brace vs no brace) did not influence the remodeling capacity. More than half of the patients (n = 18, 53 %) complained about occasional back-related pain which was not associated with the remodeling process. The mean ODI was 5.8 (range 0-26, SD 6.6) and the mean VAS of the re-evaluated patients was 87 (range 53-100, SD 14). CONCLUSIONS: A significant remodeling capacity of thoracolumbar vertebral impaction fractures sustained in childhood is demonstrated. Bracing does not seem to influence the long-term outcome of these injuries. More studies have to be performed to define the role of bracing in these fractures.

A novel mutation of the RRM2B gene in an infant with early fatal encephalomyopathy, central hypomyelination, and tubulopathy.

A baby-girl with congenital deafness was admitted at the age of 8 weeks for lack of head control, truncal hypotonia and echodense kidneys. At the age of 10 weeks cranial MRI showed a normal brain structure, generalized mild hypomyelination but no lactate peak on (1)H MR spectroscopy. A combined defect of respiratory chain enzyme complexes I, III, IV and V and severe depletion of mitochondrial DNA was found in skeletal muscle tissue. Genetic analysis revealed a novel mutation c.368T>C (p.Phe123Ser) in the RRM2B gene in the expressed maternal allele. The paternal allele was present in genomic DNA, but was not expressed as mature mRNA.

MRI of the neonatal and paediatric spine and spinal canal.

Today several modalities for imaging the spine, the spinal canal and the spinal cord are available. Since children represent one of the most vulnerable patient groups, care has to be taken and imaging assessment should start always with less invasive procedures. Thus, in neonates and infants ultrasound should be used as first line imaging procedure due to their unique features of more cartilaginous parts of the yet non-ossified bones. Beyond this age group Magnetic Resonance Imaging (MRI) represents the modality of choice for radiological assessment of the spine, the spinal canal and the spinal cord. The purpose of this review is to present MRI and common MRI findings of typical diseases in children-ranging from congenital to acquired conditions. In addition, general imaging details will be given as well as a brief embryological description of the spine and spinal canal.

Sonographic diagnosis of urethral anomalies in infants: value of perineal sonography.

OBJECTIVE: To assess the value of urethral sonography including a perineal approach in evaluating urethral anomalies in infants. METHODS: A radiology database review identified 88 patients (mean age +/- SD, 64 +/- 84 days) who underwent voiding cystourethrography (VCUG) and urethral sonography as part of extended sonography of the urinary tract. Sonographic and VCUG images and reports were reviewed to assess agreement between both modalities for detection of urethral anomalies. RESULTS: Sonography facilitated the correct diagnosis of all 3 posterior urethral valves. The only urethral diverticulum, the only ectopic ureteric insertion into the urethra, the only urogenital sinus, and the only urethrovaginal fistula were also shown on sonography. In 73 (94%) of 78 cases, sonography correctly showed the absence of anomalies. In 5 infants, sonography could not reliably assess the urethra and showed indirect signs of urethral anomalies; however, these patients had normal urethras on VCUG. CONCLUSIONS: Our data show that sonography of the urethra is a valuable tool for diagnosis of urethral anomalies. Especially, negative findings on sonography are highly suggestive of the absence of urethral anomalies. Positive or equivocal sonographic findings should indicate VCUG.

Management of intussusception.

Intussusception represents the most common abdominal emergency in infancy. The classical clinical triad, consisting of abdominal colics, red jelly stools and a palpable mass, is only present in approximately 50% of cases, 20% of patients are symptom free at clinical presentation. Primary imaging modality of choice is ultrasound scanning, which enables the diagnosis or exclusion of an intussusception at a sensitivity of 98-100%, specificity of 88% and a negative predictive value of 100%. In emergency cases, additional plain films are necessary to detect potential intestinal perforation, to identify intestinal obstruction or other diseases mimicking the clinical presentation. Once the diagnosis of an intussusception is established, non-surgical reduction (NSR) is used. A surgical approach is chosen in patients with signs of perforation, shock or peritonitis. Depending on the choice of guiding imaging technique, different contrast media are used for NSR. Barium suspension or air with fluoroscopic guidance, or saline only or mixed with water-soluble contrast under sonographic guidance, has to be used. Regardless of the used contrast medium, NSR is an effective technique, being successfully employed in more than 90% of cases.

Spiral-CT-based assessment of tracheal stenoses using 3-D-skeletonization.

PURPOSE: Demonstration of a technique for three-dimensional (3-D) assessment of tracheal-stenoses, regarding site, length and degree, based on spiral computed tomography (S-CT). PATIENTS AND METHODS: S-CT scanning and automated segmentation of the laryngo-tracheal tract (LTT) was followed by the extraction of the LTT medial axis using a skeletonization algorithm. Orthogonal to the medial axis the LTT 3-D cross-sectional profile was computed and presented as line charts, where degree and length was obtained. Values for both parameters were compared between 36 patients and 18 normal controls separately. Accuracy and precision was derived from 17 phantom studies. RESULTS: Average degree and length of tracheal stenoses was found to be 60.5% and 4.32 cm in patients compared with minor caliber changes of 8.8% and 2.31 cm in normal controls (p << 0.0001). For the phantoms an excellent correlation between the true and computed 3-D cross-sectional profile was found (p << 0.005) and an accuracy for length and degree measurements of 2.14 mm and 2.53% respectively could be determined. The corresponding figures for the precision were found to be 0.92 mm and 2.56%. CONCLUSION: LTT 3-D cross-sectional profiles permit objective, accurate and precise assessment of LTT caliber changes. Minor LTT caliber changes can be observed even in normals and, in case of an otherwise normal S-CT study, can be regarded as artifacts.

CT-based virtual tracheobronchoscopy in children--comparison with axial CT and multiplanar reconstruction: preliminary results.

BACKGROUND: 3D post-processing of spiral-CT (S-CT) data using perspective projection allows the generation of virtual views similar to endoscopy. OBJECTIVE: To evaluate whether simultaneous reading of axial S-CT, multiplanar reconstruction (MPR) and virtual tracheobronchoscopy (VTB) is more precise and accurate than reading of axial S-CT and MPR alone in paediatric patients. MATERIALS AND METHODS: S-CT studies of 15 symptomatic and 4 normal patients were investigated. Two radiologists independently read two sets of images for airway abnormalities: first axial CT and MPR, followed by axial CT, MPR and VTB. A final decision was later made by consensus. All results were compared to fibre-optic bronchoscopy (FTB). Interobserver agreement was used as an indicator of precision for the display technique used. RESULTS: At reading of axial S-CT and MPR an interobserver agreement of 89.5% (kappa=0.776, P<0.00103) was found. Based on the consensus decision, a diagnostic accuracy of 89.5% at a sensitivity 86.6% and specificity of 100% (kappa=0.776, 95% CI 0.491-1.062, P<0.00103) was achieved. At reporting on axial S-CT, MPR and VTB, all cases were classified correctly by both readers, indicating 100% accuracy, interobserver agreement, sensitivity and specificity (kappa=1.00, 95% CI 1.0-1.0, P<0.000258). CONCLUSIONS: The simultaneous display of axial S-CT, MPR and VTB raises the precision, accuracy and sensitivity of radiological reports.