Κυριακή, 12 Μαΐου 2019

Pediatric Radiology

Magnetic resonance neurography of traumatic pediatric peripheral nerve injury: beyond birth-related brachial palsy

Abstract

Traumatic peripheral nerve injury occurs more frequently in the pediatric population than previously recognized. High-resolution magnetic resonance (MR) imaging in the form of MR neurography can serve as a powerful noninvasive tool for detecting and characterizing peripheral nerve injury in children. In this review article we briefly discuss optimal methods of MR neurography image acquisition, highlighting core MR sequences necessary to characterize peripheral nerve injury. In addition, we illustrate the MR neurography appearance of normal and abnormal peripheral nerves in children, with emphasis on commonly used Seddon and Sunderland classification schemes to characterize peripheral nerve injury severity. The primary and secondary features associated with peripheral nerve injury including skeletal muscle denervation are reviewed in addition to key distinctive features that can impact operative versus nonoperative management of children. We include a checklist approach to interpreting MR neurography for the assessment of peripheral nerve injury.



Correction to: European Society of Paediatric Radiology abdominal imaging task force: statement on imaging in very early onset inflammatory bowel disease

The above article was published online with incorrect author name. The right spelling should be Damjana Kljucevsek instead of Damjana Kjucevsek. The correct name is presented here.



Evaluating growth failure with diffusion tensor imaging in pediatric survivors of high-risk neuroblastoma treated with high-dose cis-retinoic acid

Abstract

Background

The survival of patients with high-risk neuroblastoma has increased with multimodal therapy, but most survivors demonstrate growth failure.

Objective

To assess physeal abnormalities in children with high-risk neuroblastoma in comparison to normal controls by using diffusion tensor imaging (DTI) of the distal femoral physis and adjacent metaphysis.

Materials and methods

We prospectively obtained physeal DTI at 3.0 T in 20 subjects (mean age: 12.4 years, 7 females) with high-risk neuroblastoma treated with high-dose cis-retinoic acid, and 20 age- and gender-matched controls. We compared fractional anisotropy (FA), normalized tract volume (cm3/cm2) and tract concentration (tracts/cm2) between the groups, in relation to height Z-score and response to growth hormone therapy. Tractography images were evaluated qualitatively.

Results

DTI parameters were significantly lower in high-risk neuroblastoma survivors compared to controls (P<0.01), particularly if the patients were exposed to both cis-retinoic acid and total body irradiation (P<0.05). For survivors and controls, DTI values were respectively [mean ± standard deviation]: tract concentration (tracts/cm2), 23.2±14.7 and 36.7±10.5; normalized tract volume (cm3/cm2), 0.44±0.27 and 0.70±0.21, and FA, 0.22±0.05 and 0.26±0.02. High-risk neuroblastoma survivors responding to growth hormone compared to non-responders had higher FA (0.25±0.04 and 0.18±0.03, respectively, P=0.02), and tract concentration (tracts/cm2) (31.4±13.7 and 14.8±7.9, respectively, P<0.05). FA, normalized tract volume and tract concentration were linearly related to height Z-score (R2>0.31; P<0.001). Qualitatively, tracts were nearly absent in all non-responders to growth hormone and abundant in all responders (P=0.02).

Conclusion

DTI shows physeal abnormalities that correlate with short stature in high-risk neuroblastoma survivors and demonstrates response to growth hormone treatment.



Functional and structural connectivity of the brain in very preterm babies: relationship with gestational age and body and brain growth

Abstract

Background

Structural and functional changes of the brain have been reported in premature babies.

Objective

To evaluate the relationship of functional and structural connectivity with gestational age, body growth and brain maturation in very preterm babies.

Materials and methods

We studied 18 very preterm babies (gestational age: mean ± standard deviation, 29.7±1.7 weeks). We examined functional connectivity by multivariate pattern analysis of resting-state functional MRI data. We assessed structural connectivity by analysis of diffusion tensor imaging data and probabilistic tractography.

Results

The average functional connectivity of the medial orbitofrontal cortex with the rest of the brain was positively associated with gestational age (P<0.001). Fractional anisotropy of the right inferior fronto-occipital fasciculus was positively associated with head circumference at term-equivalent age. Structural connectivity of the inferior fronto-occipital fasciculus with the medial orbitofrontal cortex was positively associated with head circumference at term-equivalent age. Body weight at term-equivalent age was the only independent predictor of average structural connectivity of the medial orbitofrontal cortex with the rest of the brain (P=0.020).

Conclusion

Structural and functional connectivity of the medial orbitofrontal cortex with the rest of the brain depend on body growth and degree of prematurity, respectively.



Pediatric optic nerve and optic nerve sheath diameter on magnetic resonance imaging

Abstract

Background

The normal values of optic nerve diameter and optic nerve sheath diameter might be beneficial in defining an abnormality such as optic nerve hypoplasia, or enlarged subarachnoid space, reflecting the state of increased intracranial pressure.

Objective

To study the normal optic nerve diameter and optic nerve sheath diameter on magnetic resonance imaging (MRI) in the early years of postnatal visual development from MRI of the brain.

Materials and methods

MRI of the brain in patients ages 4 years and younger were gathered. Forty-two studies with normal intracranial findings and a lack of history of increased intracranial pressure were retrospectively reviewed by two reviewers using axial T2-weighted images. Measurements were performed in transverse diameter perpendicular to the optic nerve at 3 mm behind the globe.

Results

The mean optic nerve diameter of the 77 optic nerves were 2.5 mm (95% confidence interval [CI] 2.4–2.6). The mean optic nerve sheath diameter values of the 79 optic nerve sheath complexes were 5.0 mm (95% CI 4.9–5.1). The mean±standard deviation optic nerve diameter and optic nerve sheath diameter stratified by each age groups were, respectively, 0 to <1 year: 2.3±0.40 and 4.81±0.37; 1 to <2 years: 2.6±0.2 and 5.0±0.4; 2 to <3 years: 2.4±0.3 and 4.9±0.6, and 3 to <4 years: 2.9±0.4 and 5.2±0.60 mm.

Conclusion

Seventy-four of the 77 measurements (96%) were of the measurements were above the threshold of 2 mm for optic nerve diameter. Seventy-seven of the 79 measurements (97%) were of the measurements were below the threshold of 6 mm for optic nerve sheath diameter.



Magnetic resonance imaging T1 relaxation times for the liver, pancreas and spleen in healthy children at 1.5 and 3 tesla

Abstract

Background

T1 relaxation time is a potential magnetic resonance imaging (MRI) biomarker for fibrosis and inflammation of the solid abdominal organs. However, normal T1 relaxation times of the solid abdominal organs have not been defined for children.

Objective

The purpose of this study was to measure T1 relaxation times of the liver, pancreas and spleen in healthy children.

Materials and methods

This was an institutional review board-approved study of a convenience sample of prospectively recruited, healthy children ages 7 to 17 years undergoing research abdominal MRI (1.5 or 3 T) as part of a larger research study between February 2018 and October 2018. For the current study, T1 mapping was performed with a Modified Look-Locker sequence covering the upper abdomen. A single reviewer placed freehand regions of interest on the T1 parametric maps in the liver, pancreas and spleen, inclusive of as much parenchyma as possible. Student's t-tests and linear regression were used to compare T1 values by age and gender.

Results

Thirty-two participants were included (16 female:16 male; mean age: 12.2±3.1 years; n=16 at 1.5 T). Median T1 relaxation times (ms) per organ were liver: 581±64 (1.5 T), 783±88 (3 T); pancreas: 576±55 (1.5 T), 730±30 (3 T), and spleen: 1,172±71 (1.5 T), 1,356±87 (3 T). T1 values were not statistically significantly different between males and females. At both 1.5 and 3 T field strengths, linear regression showed no significant association between age and T1 values for the liver, pancreas and spleen.

Conclusion

We report normal T1 relaxation times for the liver, pancreas and spleen at 1.5 and 3 T in a cohort of healthy children.



Correction to: The value of postmortem computed tomography in paediatric natural cause of death: a Dutch observational study

When first published, this article inadvertently listed the Dutch NODO group individually within the author list without specifying the names of the collaborators. The collaborators have been listed within the Acknowledgements section only. The corrected author list is presented in this Correction.



Correction to: A consensus response on the complete picture: reply to Lynøe and Eriksson

The original version on this paper contained an error. The COI statement is incorrectly presented.



Correction to: The spectrum of cloacal malformations: how to differentiate each entity prenatally with fetal MRI

The published version of this article unfortunately contained a mistake. Author name Mariana Z. Meyers was incorrect. The correct middle initial is given above.



Pediatric radiologists and burnout: identifying stressors and moving forward


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