Coronal STIR MRI sequences in unexplained limping in children under 6 years old: A single-center retrospective study of 130 cases.

INTRODUCTION: Limping is a common presenting symptom in young children. Clinical examination backed up by laboratory analysis, standard radiography, and/or ultrasound may fail to determine the diagnosis, and limping may prove persistent, requiring repeated consultation. Magnetic resonance imaging (MRI) can suggest the etiology or provide welcome reassurance when normal. We advocate the use of MRI in cases of persistent unexplained limping in young children. The study hypothesis was that coronal short TI inversion recovery (STIR) MRI has good negative predictive value (NPV) in unexplained limping in children under 6 years of age. MATERIAL AND METHOD: Coronal STIR MRI sequences were analyzed in 130 children younger than 6 years (84 boys, 46 girls) during the period April 2007 to May 2017. They extended from the lower thoracic spine down to the feet. Agreement was analyzed between the radiologist's initially suggested diagnosis and the pediatric orthopedic specialist's final diagnosis. RESULTS: Overall, 49 scans were normal (37.7%) and 81 abnormal (62.3%). The mean age at MRI was 32.3 months. Coronal STIR MRI had 98% NPV. There was 99.2% agreement between the radiologist's diagnosis and the final diagnosis. DISCUSSION: The recently reported contribution of STIR MRI in bone and joint infections was extended to unexplained limping. CONCLUSION: First-line MRI with coronal STIR sequences improved the diagnostic efficacy, thanks to its speed and relative lack of movement artifacts.

Arterial spin labeling in clinical pediatric imaging.

Arterial spin labeling (ASL) perfusion-weighted magnetic resonance imaging is the only approach that enables direct and non-invasive quantitative measurement of cerebral blood flow in the brain regions without administration of contrast material and without radiation. ASL is thus a promising perfusion imaging method for assessing cerebral blood flow in the pediatric population. Concerning newborns, there are current limitations because of their smaller brain size and lower brain perfusion. This article reviews and illustrates the use of ASL in pediatric clinical practice and discusses emerging cerebral perfusion imaging applications for children due to the highly convenient implementation of the ASL sequence.

Pubo-femoral distance: an easy sonographic screening test to avoid late diagnosis of developmental dysplasia of the hip.

OBJECTIVES: To propose an easy and reproducible sonographic screening test able to avoid late presentation of developmental dysplasia of the hip (DDH). METHODS: The pubo-femoral distance (PFD) cut-off point was determined on 980 infants who underwent ultrasonography of the hips in comparison with the final diagnosis, based on clinical, ultrasound data and follow-up. PFD reproducibility was tested on 52 hips by both an experienced and an inexperienced radiologist. After teaching this screening method to general radiologists, its impact was evaluated by analysing the rate of late diagnosis in an entire administrative area. RESULTS: An abnormal PFD threshold above 6 mm gave a sensitivity of 97.4 % for the diagnosis of DDH (271 hips) and a specificity of 84 %. Sensitivity increased to 100 % when taking into consideration children of 1 month or older. The PFD measurement stayed reproducible even in inexperienced hands (k = 0.795). For 3 years, following the extension of screening to all female infants, there was no late diagnosis of DDH in girls in amongst a catchment area of 1 million inhabitants. CONCLUSIONS: PFD measurement with a threshold for abnormality of 6 mm at the age of 1 month, without asymmetry above 1.5 mm, could eradicate DDH late diagnosis.

[Developmental dysplasia of the hip]. / Luxation congénitale de hanche chez l'enfant.

At one month, the acetabular depth from a standard lateral coronal section is 4.6 ± 1.0mm. The correlation between experienced and junior radiologists is high (kappa 0.795). A treshhold of 6mm with a Δ (difference between right and left) less than 1.5mm provides a sensitivity of 100% for the detection of DDH at one month. Universal US screening at one month of all high-risk infants in 2009 resulted in a reduction of delayed diagnosis of DDH (zero girls, two boys) in Ille-et-Vilaine due to continuous medical education of general radiologists.