Reliability of cervical lordosis and global sagittal spinal balance measurements in adolescent idiopathic scoliosis.

STUDY DESIGN: Radiological reproducibility study. PURPOSE: To assess intra and interobserver reliability of radiographic measurements for global sagittal balance parameters and sagittal spine curves, including cervical spine. Sagittal spine balance in adolescent idiopathic scoliosis (AIS) is a main issue and many studies have been reported, showing that coronal and sagittal deformities often involve sagittal cervical unbalance. Global sagittal balance aims to obtain a horizontal gaze and gravity line at top of hips when subject is in a static position, involving adjustment of each spine curvature in the sagittal plane. To our knowledge, no study did use a methodologically validated imaging analysis tool able to appreciate sagittal spine contours and distances in AIS and especially in the cervical region. METHODS: Lateral full-spine low-dose EOS radiographs were performed in 75 patients divided in three groups (control subjects, AIS, operated AIS). Three observers digitally analyzed twice each radiograph and 11 sagittal measures were collected for each image. Reliability was assessed calculating intraobserver Pearson's r correlation coefficient, interobserver intra-class correlation coefficient (ICC) completed with a two-by-two Bland-Altman plot analysis. RESULTS: This measurement method has shown excellent intra and interobserver reliability in all parameters, sagittal curvatures, pelvic parameters and global sagittal balance. CONCLUSIONS: This study validated a simple and efficient tool in AIS sagittal contour analysis. It defined new relevant landmarks allowing to characterize cervical segmental curvatures and cervical involvement in global balance.

Chronic recurrent multifocal osteomyelitis (CRMO): a longitudinal case series review.

BACKGROUND: Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory disorder that is currently diagnosed based on clinical, radiologic, pathological and longitudinal findings. OBJECTIVE: To provide detailed descriptions of CRMO lesion patterns seen on radiographs and MRI and to suggest clinical use of whole-body MRI and propose noninvasive diagnostic strategy. MATERIALS AND METHODS: Retrospective longitudinal study (1989-2010) of 31 children (22 girls, 9 boys) diagnosed with CRMO. Imaging data were evaluated by two pediatric radiologists. RESULTS: Mean age at diagnosis was 11 years (3-17). A total of 108 lesions were investigated. The most common sites were the long bone metaphyses (56 lesions in 24 children) especially femoral and tibial (20/24); pelvis (10/31); spine (9/31); clavicle (6/31) and mandible (3/31). In long bones, the radiologic appearance was normal (22/56), mixed lytic and sclerotic (20/56), sclerotic (8/56) or lytic (6/56) often juxtaphyseal (36/56), with hyperostosis or periosteal thickening (10/56). Vertebral involvement was often multifocal (6/9). Medullary edema was seen on MRI (42) with epiphyseal (23/42) or soft-tissue (22/42) inflammation and juxtaphyseal nodule-like appearance (7/42). Whole-body MRI (15/31) was key in detecting subclinical lesions. CONCLUSION: CRMO is a polymorphous disorder in which whole-body MRI is extremely useful for showing subclinical edema. Vertebral collapse requires long-term monitoring.

Brain iron levels in attention-deficit/hyperactivity disorder: a pilot MRI study.

OBJECTIVE: Brain iron deficiency has been supposed to be involved in the pathophysiology of ADHD. Available studies assessing iron in ADHD are based on serum ferritin, a peripheral marker of iron status. To what extent serum ferritin correlates with brain iron (BI) is unclear. The main aim of this study was to compare BI, estimated with magnetic resonance imaging (MRI) in the putamen, pallidum, caudate, and thalamus, between children with and without ADHD. The secondary aim was to assess the correlation between serum ferritin and BI levels. METHODS: Thirty-six children (18 with and 18 without ADHD, the latter including nine healthy controls and nine psychiatric controls) completed MRI and blood sampling. Brain iron levels were estimated by imaging T2*. RESULTS: Children with ADHD showed significantly lower estimated BI in right and left thalamus compared to healthy controls. Estimated BI did not differ significantly between children with ADHD and psychiatric controls. Children with ADHD had significantly lower levels of serum ferritin than healthy as well as psychiatric controls. Serum ferritin and T2* values did not correlate significantly in most regions. CONCLUSIONS: Low iron in the thalamus may contribute to ADHD pathophysiology.

Renal safety in pediatric imaging: randomized, double-blind phase IV clinical trial of iobitridol 300 versus iodixanol 270 in multidetector CT.

BACKGROUND: It is debated whether iso-osmolar and low-osmolar contrast media are associated with different incidences of contrast medium-induced nephropathy (CIN) in patients with renal insufficiency. OBJECTIVE: To compare the incidence of CIN in children undergoing contrast-enhanced multidetector computer tomography (MDCT) with intravenous injection of low-osmolar (iobitridol, Xenetix® 300) or an iso-osmolar (iodixanol, Visipaque® 270) iodinated contrast medium. MATERIALS AND METHODS: One hundred forty-six children with normal renal function were included in this multicenter trial and underwent contrast-enhanced MDCT. The primary endpoint was the relative change in creatinine clearance from 48 h pre- to 72 h postcontrast medium administration using a noninferiority analysis in the intent-to-treat (ITT, n = 128) and per protocol (n = 68) populations. Secondary endpoints were incidence of CIN, global image quality, diagnostic efficacy and clinical safety. RESULTS: In the ITT population, the noninferiority of iobitridol over iodixanol was demonstrated. CIN incidence was 4.8% (three cases) with iobitridol and 10.6% (seven cases) with iodixanol (not significant). No statistically significant differences were observed for the secondary endpoints. CONCLUSION: Comparable satisfactory safety profiles were confirmed for both contrast media, with no significant difference in the incidence of CIN in children with normal renal function.

Renal parenchymal fibrosis and atrophy are not correlated with upper tract dilatation: long-term study of partial unilateral ureteral obstruction in neonatal mice.

PURPOSE: The mechanism underlying the evolution of congenital obstructive hydronephrosis is still unclear. In a previous study, we have shown that it is possible to create renal lesions in newborn mice specific to partial ureteral obstruction. We aimed to study the long-term results of such partial obstruction. METHODS: Mice were operated on the third day of life. We created 2 groups: partial unilateral obstruction and control. We studied antero-posterior pelvis diameter, kidney length and volume on magnetic resonance imaging at day 10 and 3 months. We assessed ureteric patency by injecting Patent Blue dye. Kidney weight and fibrosis were histologically assessed. Fibrosis was assessed using Sirius Red staining and morphometry. RESULTS: Imaging showed parenchymal atrophy in the partially obstructed kidney and compensatory hypertrophy of the contralateral kidney. Pelvis dilatation was detected at day 10 but remained stable without significant increase at 3 months. The patency test confirmed the absence of total obstruction in the long term. There was no correlation between the degree of dilatation and parenchymal atrophy or the contralateral hypertrophy. Pathological studies at 3 months revealed fibrosis in the parenchyma without significant correlation with pelvis dilatation. CONCLUSIONS: Long-term results confirmed that partial ureteral obstruction in newborn mice produces fibrotic lesions of the renal parenchyma, which are not correlated with dilatation of the upper tract. These results could contribute to the clinical management of obstructive uropathy in children, emphasizing that follow up with simple evaluation of upper tract dilatation is insufficient to predict renal deterioration.

In vivo assessment of experimental neonatal excitotoxic brain lesion with USPIO-enhanced MR imaging.

PURPOSE: To assess the feasibility of magnetic resonance imaging (MRI) enhanced with ultrasmall superparamagnetic particles of iron oxide (USPIO) for assessing excitotoxic brain lesions in an experimental model of neonatal periventricular white matter (PWM) lesions. MATERIALS AND METHODS: Brain lesions were induced by intracerebral injection of ibotenate in 14 newborn rats. Pre- and post-USPIO T2-weighted MRI was performed in seven of them (group A) and in five control newborns (group C). In seven newborns with induced cerebral lesions, USPIO-enhanced MRI was not performed (group B). We compared the signal intensity of the lesion to the contralateral unaffected brain (lesion-to-brain contrast, LBC) and the lesion signal-to-noise ratio (SNR) before and after USPIO injection. MR imaging was correlated with histology. RESULTS: USPIO injection significantly (P<0.05) decreased LBC and SNR of brain lesion but induced no changes in normal controls. The densities of macrophages and iron-laden cells were higher on the lesion side than on the contralateral side (P<0.05). Neither lesion size nor the surrounding macrophage infiltrate was significantly different between groups A and B. CONCLUSION: Post-USPIO T2-weighted MRI demonstrated negative enhancement of neonatal excitotoxic brain lesion. USPIO injection does not appear to exacerbate brain lesions.

USPIO (Ferumoxtran-10)-enhanced MRI to visualize reticuloendothelial system cells in neonatal rats: feasibility and biodistribution study.

PURPOSE: To investigate whether USPIO-enhanced magnetic resonance imaging (MRI) detected reticuloendothelial system (RES) cells in newborn normal rats. MATERIALS AND METHODS: Newborn normal rats were imaged in vivo on a 1.5 T MR system, 2-96 hours after intraperitoneal Ferumoxtran-10 (n = 38) or saline injection (control group, n = 5). Signals from liver, spleen, and vertebral bone marrow were measured (T2-weighted Turbo Spin Echo) to describe the kinetics of enhancement. The pups were sacrificed and iron concentrations in plasma and peritoneal fluid were measured using atomic absorption spectrometry. Prussian blue-labeled cells density in liver, spleen, and vertebral bone marrow was assessed. RESULTS: Significant (P < 0.05) negative enhancement of the liver, spleen, and vertebral bone marrow was noted after Ferumoxtran-10 injection (2-96 hours for liver and spleen, 4-96 hours for bone marrow). Ferumoxtran-10 was absorbed from the peritoneum in the first 8 hours postinjection, entering the circulation with a plasma peak (8 hours); then Ferumoxtran-10 returned over the baseline in plasma (96 hours). Important intracellular iron deposition in liver and spleen was measured postinjection (3-96 hours, P < 0.05). Limited but significant intracellular iron deposition was noted in vertebral bone marrow postinjection (96 hours, P < 0.05), suggesting that Ferumoxtran-10 selectively labeled RES cells after 96 hours and produced nonspecific labeling at earlier timepoints. CONCLUSION: Ferumoxtran-10-enhanced MRI visualizes RES cells in vivo in newborn rats.

Partial unilateral ureteral obstruction in newborn mice: magnetic resonance imaging and pathology studies.

PURPOSE: The mechanism underlying the evolution of congenital obstructive hydronephrosis in humans is still unclear. Although partial unilateral ureteral obstruction has been extensively explored in rats, studies in neonatal mice may lead to new insights into underlying cellular mechanisms, especially with the availability of mutant mice. We developed a model of partial unilateral ureteral obstruction in newborn mice. MATERIALS AND METHODS: Mice were operated on by the fifth day of life. We created 3 groups, namely partial unilateral ureteral obstruction (embedding the ureter in the psoas muscle), complete unilateral ureteral obstruction (ligating the ureter) and sham (exposing the ureter). We studied pelvis diameter and kidney length on magnetic resonance imaging, and kidney weight, inflammation, apoptosis and fibrosis on histological assessment during the second (early) and fourth weeks (late) postoperatively. RESULTS: Magnetic resonance imaging showed enlarged pelvis diameter in late partial unilateral ureteral obstruction, and in early and late complete unilateral ureteral obstruction. Pathological studies revealed parenchyma atrophy in early and late partial unilateral ureteral obstruction. Apoptosis occurred early in partial unilateral ureteral obstruction and decreased later. Macrophage infiltration was enhanced in early and late partial unilateral ureteral obstruction. Fibrosis increased in late partial unilateral ureteral obstruction. All of these results were significantly intermediate between mice with complete unilateral ureteral obstruction and sham operated mice. CONCLUSIONS: It is possible to create renal lesions in newborn mice specific to partial ureteral obstruction. Magnetic resonance imaging of morphological changes demonstrated specific features of partial unilateral ureteral obstruction. Being noninvasive, this approach opens the way for further studies to investigate prognostic parameters after partial ureteral obstruction. In the future this model could be used in knockout mice to study the pathogenesis of renal lesions secondary to obstruction.

Ultrasonography of Crohn disease in children.

US is increasingly performed in Crohn disease (CD) in children as a first line imaging modality. It reduces the use of other more invasive examinations such as endoscopy, CT or contrast enema. We describe bowel ultrasonography technique, normal bowel appearances on US and pathological patterns in CD. We discuss the current role and limitations of bowel US in CD in children including diagnosis, extent of disease, assessment of disease activity, follow-up and detection of complications. The diagnostic accuracy of US is discussed according to the literature and compared to other imaging modalities. US is currently used for screening in children with the suspicion of inflammatory bowel disease (IBD) with a good negative predictive value. In follow-up, US has a role in monitoring medical treatment by evaluating disease activity, extent of disease and for detecting complications.

MRI of the olfactory bulbs and sulci in human fetuses.

BACKGROUND: There is limited knowledge of the MRI pattern of the development of fetal olfactory bulbs and sulci. OBJECTIVE: To describe the MRI appearance of olfactory bulbs and sulci in normal in vivo fetuses according to gestational age. MATERIALS AND METHODS: Olfactory bulbs and sulci were retrospectively assessed on brain MRI examinations of 88 normal fetuses between 24 and 39 weeks gestational age. Two reference centres were involved in the study and both used routine protocols that included axial and coronal T2- and T1-weighted sequences at 1.5 T. The results were compared both with the commonly used neuropathological data in the literature and with personal neuropathological data. Pearson's chi-squared test or Fisher's exact test were performed. One case of olfactory agenesis associated with CHARGE syndrome was identified. RESULTS: T2-weighted coronal sequences were the most sensitive for detecting olfactory bulbs and sulci. Olfactory sulci were significantly better detected from 30 weeks onwards (90.9-100%; P<0.001). MRI showed a posteroanterior development of these sulci. Olfactory bulbs were better detected from 30 to 34 weeks (80-90.9%; P<0.002). Comparison with neuropathological data confirmed the posteroanterior development of the sulci and showed an important delay in detection of the olfactory structures (bulbs and sulci). No difference was observed between the two centres involved. CONCLUSIONS: To date, fetal MRI can depict olfactory sulci from 30 weeks gestational age onwards and olfactory bulbs from 30 to 34 weeks gestational age. This preliminary reference standard is useful to assess the normality of the olfactory system and to diagnose olfactory agenesis.

Lacrimal location of sinus histiocytosis (Rosai-Dorfman-Destombes disease).

A 7-year-old West African male patient presented with recurrence of multiple cervical lymphadenopathy. Cervical node biopsy disclosed a sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman-Destombes disease). During follow-up, the patient developed a left orbital mass corresponding to an enlarged lacrimal gland shown by CT. The histologic features of the gland were consistent with the diagnosis, and with steroid treatment, the gland decreased in size. Although rare, the diagnosis of sinus histiocytosis with massive lymphadenopathy has to be considered in cases of lacrimal gland enlargement.