In utero diffusion tensor imaging of the fetal brain: a reproducibility study

Our purpose was to evaluate the within-subject reproducibility of in utero diffusion tensor imaging (DTI) metrics and the visibility of major white matter structures. Images for 30 fetuses (20-33. postmenstrual weeks, normal neurodevelopment: 6 cases, cerebral pathology: 24 cases) were acquired on 1.5 T or 3.0 T MRI. DTI with 15 diffusion-weighting directions was repeated three times for each case, TR/TE: 2200/63 ms, voxel size: 1 ∗ 1 mm, slice thickness: 3-5 mm, b-factor: 700 s/mm(2). Reproducibility was evaluated from structure detectability, variability of DTI measures using the coefficient of variation (CV), image correlation and structural similarity across repeated scans for six selected structures. The effect of age, scanner type, presence of pathology was determined using Wilcoxon rank sum test. White matter structures were detectable in the following percentage of fetuses in at least two of the three repeated scans: corpus callosum genu 76%, splenium 64%, internal capsule, posterior limb 60%, brainstem fibers 40% and temporooccipital association pathways 60%. The mean CV of DTI metrics ranged between 3% and 14.6% and we measured higher reproducibility in fetuses with normal brain development. Head motion was negatively correlated with reproducibility, this effect was partially ameliorated by motion-correction algorithm using image registration. Structures on 3.0 T had higher variability both with- and without motion correction. Fetal DTI is reproducible for projection and commissural bundles during mid-gestation, however, in 16-30% of the cases, data were corrupted by artifacts, resulting in impaired detection of white matter structures. To achieve robust results for the quantitative analysis of diffusivity and anisotropy values, fetal-specific image processing is recommended and repeated DTI is needed to ensure the detectability of fiber pathways

Arterial spin labelling MRI for assessment of cerebral perfusion in children with moyamoya disease: comparison with dynamic susceptibility contrast MRI

Introduction: This study seeks to evaluate the diagnostic accuracy of cerebral perfusion imaging with arterial spin labelling (ASL) MR imaging in children with moyamoya disease compared to dynamic susceptibility contrast (DSC) imaging. Methods: Ten children (7 females; age, 9.2 ± 5.4years) with moyamoya disease underwent cerebral perfusion imaging with ASL and DSC on a 3-T MRI scanner in the same session. Cerebral perfusion images were acquired with ASL (pulsed continuous 3D ASL sequence, 32 axial slices, TR = 5.5s, TE = 25ms, FOV = 24cm, matrix = 128 × 128) and DSC (gradient echo EPI sequence, 35 volumes of 28 axial slices, TR = 2,000ms, TE = 36ms, FOV = 24cm, matrix = 96 × 96, 0.2ml/kg Gd-DOTA). Cerebral blood flow maps were generated. ASL and DSC images were qualitatively assessed regarding perfusion of left and right ACA, MCA, and PCA territories by two independent readers using a 3-point-Likert scale and quantitative relative cerebral blood flow (rCBF) was calculated. Correlation between ASL and DSC for qualitative and quantitative assessment and the accuracy of ASL for the detection of reduced perfusion per territory with DSC serving as the standard of reference were calculated. Results: With a good interreader agreement (κ = 0.62) qualitative perfusion assessment with ASL and DSC showed a strong and significant correlation (ρ = 0.77; p < 0.001), as did quantitative rCBF (r = 0.79; p < 0.001). ASL showed a sensitivity, specificity and accuracy of 94%, 93%, and 93% for the detection of reduced perfusion per territory. Conclusion: In children with moyamoya disease, unenhanced ASL enables the detection of reduced perfusion per vascular territory with a good accuracy compared to contrast-enhanced DS

Pediatric papillary tumors of the pineal region: to observe or to treat following gross total resection?

Introduction: Papillary tumors of the pineal region (PTPR) are rare brain tumors characterized by frequent local recurrences. Standardized treatment strategies are not yet defined. Case report: We present the case of a 3-year-old girl diagnosed with PTPR. Due to her young age, adjuvant radiotherapy was omitted after gross total tumor resection. Thirty-six months later, local tumor recurrence occurred. Considering the possible risks of secondary surgery, the recurrent tumor was irradiated with proton radiotherapy. Three months later, the tumor showed near-complete remission. Discussion: Based on this experience and other pediatric case reports from the literature, local radiotherapy might be suggested also after complete tumor resectio

Non-invasive diagnosis of lung tuberculosis in children by single voxel 1H-magnetic resonance spectroscopy

Our previous study showed that 1H-magnetic resonance spectroscopy (1H-MRS) can detect lipid peaks characteristic for Mycobacterium tuberculosis infection in cerebral lesions of young children; therefore, we aimed to extend and validate the application of 1H-MRS for the diagnosis of active pulmonary tuberculosis lesions in three adolescent patients. Here, we document lipid peaks characteristic for M. tuberculosis infection by 1H-MRS from lung tissue surrounding lung cavities of two patients whose sputum samples were positive for acid-fast bacilli by microscopy and positive for M. tuberculosis by genetic testing, indicating active tuberculosis. A similar lipid peak was found also in the pleural effusion of a third patient with concurrent lung cavity compatible with active tuberculosis. However, in a patient with a pyogenic pulmonary abscess, 1H-MRS of the drained pus displayed different characteristic peaks but no lipid peak at all. Conclusion: Our findings further validate 1H-MRS as a rapid, non-invasive, and specific diagnostic tool for active tuberculosis in children with microbiologically documented infection outside the central nervous system, specifically in the lung

Natural history of a medulloblastoma: 30months of wait and see in a child with a cerebellar incidentaloma

Introduction: With the increasing use of neuroimaging studies, the discovery of incidental neoplastic lesions is becoming more frequent. However, standard procedures are lacking, and little is known about their optimal management. Case Report: We here present the case of a boy with a cerebellar mass incidentally discovered on a CT scan performed after head trauma. In another scan performed after another incident of head trauma 14months earlier, the lesion could be seen after retrospective examination. In view of the asymptomatic clinical and stable radiological status and the presumed diagnosis of a low-grade glioma, a watch-and-wait strategy was elected. After clinical and radiological progression was observed, the tumour was resected, 2½ years after the initial imaging study. Histological evaluation revealed a WNT pathway-activated classical medulloblastoma. Discussion: To our knowledge, this is the first description of such a long natural history and pre-symptomatic period of a medulloblastoma. The long period of stability followed by a period of accelerated tumour growth is compatible with increasing biological aggressiveness, possibly related to the stepwise accumulation of genetic change

CRIM-negative infantile Pompe disease: 42-month treatment outcome

Pompe disease is a rare lysosomal glycogen storage disorder characterized by deficiency of acid α-glucosidase enzyme (GAA) and caused by mutations in the GAA gene. Infantile-type Pompe disease is a multiorgan disorder presenting with cardiomyopathy, hypotonia, and muscular weakness, which is usually fatal. Enzyme replacement therapy (ERT) with recombinant human GAA (rhGAA) has recently been shown to be effective and subsequently yielded promising results in cross-reactive immunologic material (CRIM)-positive patients. CRIM-negative patients showed a limited response to ERT and died or were ventilator dependant. Over a period of 44months, we monitored cognitive and motor development, behavior, auditory function, and brain imaging of a CRIM-negative infantile Pompe disease patient on rhGAA and monoclonal anti-immunoglobulin E (anti-IgE) antibody (omalizumab) treatment due to severe allergic reaction. Cardiorespiratory and skeletal muscle response was significant, with almost normal motor development. Cognitive development—in particular, speech and language—deviated increasingly from normal age-appropriate development and was markedly delayed at 44months, unexplained by moderate sensorineural hearing impairment. Brain magnetic resonance imaging (MRI) at 18, 30, and 44months of age revealed symmetrical signal alteration of the deep white matter. Titer values of IgG antibodies to rhGAA always remained <1:800. The potential role of omalizumab in immune modulation remains to be elucidated; however, this is the first report presenting a ventilator-free survival of a CRIM-negative patient beyond the age of 36months. The central nervous system (CNS) findings are hypothesized to be part of a yet not fully described CNS phenotype in treated patients with longer surviva

Intra-voxel incoherent motion MRI of the living human foetus: technique and test-retest repeatability

Background Our purpose was to test the within-subject (test-retest) reproducibility of the perfusion fraction, diffusion coefficient, and pseudo-diffusion coefficient measurements in various foetus organs and in the placenta based on the intra-voxel incoherent motion (IVIM) principle. Methods In utero diffusion-weighted IVIM magnetic resonance imaging (MRI) was performed in 15 pregnant women (pregnancy age 21-36 weeks) on 1.5-T and 3.0-T clinical scanners with b-factors in the range of 0-900 s/mm in 16 steps. A bi-exponential model was fitted on the volume-averaged diffusion values. Perfusion fraction (f), diffusion coefficient (d), and pseudo-diffusion coefficient (D*) were calculated. Within-subject reproducibility was evaluated as test-retest variability (VAR %) of the IVIM parameters in the foetal frontal cortex, frontal white matter, cerebellum, lungs, kidneys, liver, and in the placenta. Results For the foetal lungs, liver and the placenta, test-retest variability was in the range of 14-20% for f, 12-14% for d, and 17-25% for D*. The diffusion coefficients of the investigated brain regions were moderately to highly reproducible (VAR 5-15%). However, f and D* showed inferior reproducibility compared to corresponding measures for the lungs, liver, and placenta. The IVIM parameters of the foetal kidney were revealed to be highly variable across scans. Conclusions IVIM MRI potentially provides a novel method for examining microvascular perfusion and diffusion in the developing human foetus. However, reproducibility of perfusion and diffusion parameters depends greatly upon data quality, foetal and maternal movements, and foetal-specific image post-processing

Cerebral lesions on magnetic resonance imaging correlate with preoperative neurological status in neonates undergoing cardiopulmonary bypass surgery

OBJECTIVES To determine the prevalence, spectrum and course of cerebral lesions in neonates with congenital heart disease (CHD) undergoing full flow cardiopulmonary bypass (CPB) surgery using magnetic resonance imaging (MRI) and to examine the correlation between cerebral lesions and clinical neurological abnormalities. METHODS Prospective cohort study of neonates with d-transposition of the great arteries (n = 22), univentricular heart malformation with hypoplastic aortic arch (n = 6) and aortic arch obstructions (n = 2) undergoing CPB. Neonates underwent cerebral MRI and blinded standardized neurological examination before (median day 6) and after surgery (day 13). The MRI findings were compared with those of 20 healthy controls. RESULTS Preoperative cerebral lesions were present in 7 of 30 patients (23%) with isolated mild or moderate white matter injury (WMI) (n = 4), isolated small cerebral stroke (n = 1) and combined WMI and stroke (n = 2). None of the healthy controls had cerebral lesions on MRI. CHD neonates with preoperative cerebral lesions had more neurological abnormalities (P = 0.01) than neonates without cerebral lesions. Low arterial oxygen saturation (P = 0.03) was a risk factor for preoperative cerebral lesions, while balloon atrioseptostomy (P = 0.19) was not. After surgery, preoperative cerebral lesions persisted in 5 of 7 neonates, and 2 neonates (7%) showed signs of additional WMI in their postoperative MRI. CONCLUSIONS In neonates with severe CHD, WMI was the predominant preoperative finding, while cerebral strokes were less frequent. New postoperative lesions were rare. Preoperative neurological abnormalities correlated with the presence of cerebral lesions on MR

Non-invasive diagnosis of lung tuberculosis in children by single voxel ¹H-magnetic resonance spectroscopy

Our previous study showed that (1)H-magnetic resonance spectroscopy ((1)H-MRS) can detect lipid peaks characteristic for Mycobacterium tuberculosis infection in cerebral lesions of young children; therefore, we aimed to extend and validate the application of (1)H-MRS for the diagnosis of active pulmonary tuberculosis lesions in three adolescent patients. Here, we document lipid peaks characteristic for M. tuberculosis infection by (1)H-MRS from lung tissue surrounding lung cavities of two patients whose sputum samples were positive for acid-fast bacilli by microscopy and positive for M. tuberculosis by genetic testing, indicating active tuberculosis. A similar lipid peak was found also in the pleural effusion of a third patient with concurrent lung cavity compatible with active tuberculosis. However, in a patient with a pyogenic pulmonary abscess, (1)H-MRS of the drained pus displayed different characteristic peaks but no lipid peak at all. CONCLUSION: Our findings further validate (1)H-MRS as a rapid, non-invasive, and specific diagnostic tool for active tuberculosis in children with microbiologically documented infection outside the central nervous system, specifically in the lungs

Premiere use of Integra™ artificial skin to close an extensive fetal skin defect during open in utero repair of myelomeningocele

Background: There are fetuses demonstrating very large myelomeningocele lesion which can not be covered with autochothonous skin. Material and Methods: We use Integra™ artifical skin for intrauterine coverage of the back lesion. A reverse latissimus dorsi flap was used postnataly to reinforce the repair site. Conclusion: Integra™ appears to be a suitable coverage for large soft tissue defects in utero. Moreover, a postnatal reverse latissimus dorsi flap appears to markedly strengthen tissue coverage over a spinal cord rescued in uter