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To differentiate hypo-/hypertelorism (abnormal) from normal fetuses using automatic biometric measurements and machine learning (ML) classification based on MRI.MRI data of normal (n = 244) and abnormal (n = 52) fetuses of 22-40 weeks' gestational age (GA), scanned between March 2008 and June 2020 on 1.5/3T systems with various TThe automatic method yielded a mean difference of BOD = 0.70 mm, IOD = 0.81 mm, OD = 1.00 mm, and a 3D-Dice score of OV = 93.7%. In normal fetuses, all four measurements increased with GA. Constant values were detected for BOD-ratio = 1.56 ± 0.05 and IOD-ratio = 0.60 ± 0.05 across all GA and when calculated from previously published reference data of both MRI and ultrasound. A random forest classifier yielded the best results on an independent test set (n = 58): AUC-ROC = 0.941 and FThe developed fully automatic method demonstrates high performance on varied clinical imaging data. The new BOD and IOD ratios and ML multi-parametric classifier are suggested to improve the differentiation of hypo-/hypertelorism from normal fetuses.• A fully automatic method for computing fetal ocular biometry from MRI is proposed, achieving high performance, comparable to that of an expert fetal neuro-radiologist. • Two new parameters, IOD-ratio and BOD-ratio, are proposed for routine clinical use in ultrasound and MRI. These two ratios are constant across gestational age in normal fetuses, consistent across studies, and differentiate between fetuses with and without hypo/hypertelorism. • Multi-parametric machine learning classification based on automatic measurements and the two new ratios improves the identification of fetal ocular anomalies beyond the accepted criteria (5

Objective Conventional pediatric spine MRI protocols have multiple sequences resulting in long acquisition times. Sedation is consequently required. This study evaluates the diagnostic capability of a limited MRI spine protocol for selected common pediatric indications. Methods Spine MRIs at CHEO between 2017 and 2020 were reviewed across pediatric patients younger than four years old. Two blinded neuroradiologists reviewed limited scan sequences and results were independently compared to previously reported findings from the complete imaging series. T2 sagittal sequences from the craniocervical junction to sacrum and T1 axial sequence of the lumbar spine constitute the short protocol, with the outcomes of interest being cerebellar ectopia, syrinx, level of conus, filum 95% in all but identifying a filum 0.91) and specificity (> 0.99) for the detection of cerebellar ectopia, syrinx, fatty filum, and spinal dysraphism. Conclusion This study demonstrates that selected spinal imaging sequences allow for consistent and accurate diagnosis of specific clinical conditions. A limited spine imaging protocol has potential as a screening test to reduce the need for full sequence MRI scans. Further work is needed to determine utility of selected imaging for other clinical indications.

Objectives MR enterography (MRE) Index of Activity (MaRIA) and Clermont are validated scores that correlate with Crohn’s disease (CD) activity; however, the Clermont score has not been validated to correlate with the degree of change in mucosal inflammation post induction treatment in children. This pilot study evaluated if MaRIA and Clermont scores can serve as surrogates to ileocolonoscopy for assessing interval change in mucosal inflammation in pediatric CD post-induction treatment. Methods Children with known or newly diagnosed ileocolonic CD starting or changing therapy underwent ileocolonoscopy, scored with simple endoscopic score for Crohn’s disease (SES-CD), and MRE on the same day at two time points (Week 0 and 12). Accuracy of global MaRIA and Clermont indices relative to ileocolonoscopy in detecting degree of post-treatment interval change in mucosal inflammation was assessed through correlational coefficients (r). Inter-reader agreement was calculated for imaging scores through intraclass correlation (ICC). Results Sixteen children (mean age 11.5 ± 2.8) were evaluated. Global MaRIA/Clermont correlated with SES-CD in detecting the degree of change in mucosal inflammation (r = 0.676 and r = 0.677, P < 0.005, respectively). Correlation for pooled timepoint assessments between SES-CD and global MaRIA/Clermont was moderate (r = 0.546, P < 0.001 and r = 0.582, P < 0.001, respectively). Inter-rater reliability for global MaRIA and Clermont was good (ICC = 0.809 and ICC = 0.768, respectively, P < 0.001). Conclusions MRE-based global scores correlate with endoscopic indices and may be used to monitor disease changes in children with CD undergoing induction treatment, which can advise the physician if treatment changes should be made.

The role of post-mortem fetal conventional autopsy (CA) is undisputed but poses challenges with small, macerated bodies, and increasing parental refusal. Fetal post-mortem magnetic resonance imaging (PMMRI) is a less invasive alternative that can be used for assessment of the brain, including the posterior fossa (PF) structures. The purpose of this study was to evaluate the imaging characteristics of the PF in PMMRI compared to antenatal MRI (ANMRI), using CA as the gold standard. A retrospective, single-center study of ten fetuses who underwent ANMRI, PMMRI, and CA from August 2010 to May 2018. The PF structures were evaluated qualitatively for imaging findings, and quantitatively by obtaining the transcerebellar diameter, vermian length, brainstem thickness, width of the fourth ventricle and cisterna magna, skull base angles, and PF volume. Twenty MRI exams were included. The median gestational age of ANMRI was 21.7 weeks. The median age at termination of pregnancy (TOP) and PMMRI was 23.7 weeks. There was good congruence between PMMRI, ANMRI, and CA, with 60% complete congruence and 40% partial congruence between ANMRI and PMMRI. PMMRI and CA showed 70% complete congruence, and 20% partial congruence. No incongruence was noted. PF evaluation on CA was not possible in 1 case due to maceration. Quantitative evaluation in PMMRI showed significant enlargement of most PF structures compared to ANMRI and smaller CSF-filled spaces (p value < 0.05). PMMRI is an acceptable imaging modality for the macroscopic evaluation of PF structures. Smaller CSF-filled spaces and enlargement of the brain are expected findings when evaluating PMMRI.

Objectives To compare WB-MRI with an [18F]FDG-PET/CT-based reference for early response assessment and restaging in children with Hodgkin’s lymphoma (HL). Methods Fifty-one children (ages 10–17) with HL were included in this prospective, multicentre study. All participants underwent WB-MRI and [18F]FDG-PET/CT at early response assessment. Thirteen of the 51 patients also underwent both WB-MRI and [18F]FDG-PET/CT at restaging. Two radiologists independently evaluated all WB-MR images in two separate readings: without and with DWI. The [18F]FDG-PET/CT examinations were evaluated by a nuclear medicine physician. An expert panel assessed all discrepancies between WB-MRI and [18F]FDG-PET/CT to derive the [18F]FDG-PET/CT-based reference standard. Inter-observer agreement for WB-MRI was calculated using kappa statistics. Concordance, PPV, NPV, sensitivity and specificity for a correct assessment of the response between WB-MRI and the reference standard were calculated for both nodal and extra-nodal disease presence and total response evaluation. Results Inter-observer agreement of WB-MRI including DWI between both readers was moderate (κ 0.46–0.60). For early response assessment, WB-MRI DWI agreed with the reference standard in 33/51 patients (65%, 95% CI 51–77%) versus 15/51 (29%, 95% CI 19–43%) for WB-MRI without DWI. For restaging, WB-MRI including DWI agreed with the reference standard in 9/13 patients (69%, 95% CI 42–87%) versus 5/13 patients (38%, 95% CI 18–64%) for WB-MRI without DWI. Conclusions The addition of DWI to the WB-MRI protocol in early response assessment and restaging of paediatric HL improved agreement with the [18F]FDG-PET/CT-based reference standard. However, WB-MRI remained discordant in 30% of the patients compared to standard imaging for assessing residual disease presence. Key Points • Inter-observer agreement of WB-MRI including DWI between both readers was moderate for (early) response assessment of paediatric Hodgkin’s lymphoma. • The addition of DWI to the WB-MRI protocol in early response assessment and restaging of paediatric Hodgkin’s lymphoma improved agreement with the [18F]FDG-PET/CT-based reference standard. • WB-MRI including DWI agreed with the reference standard in respectively 65% and 69% of the patients for early response assessment and restaging.

The identification of children with traumatic brain injury (TBI) who are at risk of death or poor global neurological functional outcome remains a challenge. Magnetic resonance imaging (MRI) can detect several brain pathologies that are a result of TBI; however, the types and locations of pathology that are the most predictive remain to be determined. Forty-two critically ill children with TBI were recruited prospectively from pediatric intensive care units at five Canadian children's hospitals. Pathologies detected on subacute phase MRIs included cerebral hematoma, herniation, cerebral laceration, cerebral edema, midline shift, and the presence and location of cerebral contusion or diffuse axonal injury (DAI) in 28 regions of interest were assessed. Global functional outcome or death more than 12 months post-injury was assessed using the Pediatric Cerebral Performance Category score. Linear modeling was employed to evaluate the utility of an MRI composite score for predicting long-term global neurological function or death after injury, and nonlinear Random Forest modeling was used to identify which MRI features have the most predictive utility. A linear predictive model of favorable versus unfavorable long-term outcomes was significantly improved when an MRI composite score was added to clinical variables. Nonlinear Random Forest modeling identified five MRI variables as stable predictors of poor outcomes: presence of herniation, DAI in the parietal lobe, DAI in the subcortical white matter, DAI in the posterior corpus callosum, and cerebral contusion in the anterior temporal lobe. Clinical MRI has prognostic value to identify children with TBI at risk of long-term unfavorable outcomes.

ObjectiveConventional pediatric spine MRI protocols have multiple sequences resulting in long acquisition times. Sedation is consequently required. This study evaluates the diagnostic capability of a limited MRI spine protocol for selected common pediatric indications. MethodsAfter REB approval, records of pediatric patients under 4 years of age who underwent a spine MRI at CHEO between 2017 and 2020 were reviewed. Two neuroradiologists blindly and retrospectively reviewed the T2 sagittal sequences from the craniocervical junction to sacrum and T1 axial sequence of the lumbar spine, to answer specific questions regarding cerebellar ectopia, syrinx, level of conus, filum 95% in all but identifying a filum 0.91) and specificity (>0.99) for the detection of cerebellar ectopia, syrinx, fatty filum, and spinal dysraphism. ConclusionThis study demonstrates that selected spinal imaging sequences allows for consistent and accurate diagnosis of specific clinical conditions. A limited spine protocol reduces acquisition time, potentially avoiding sedation. Further work is needed to determine the utility of selected imaging for other clinical indications.

Equity, diversity and inclusion (EDI) in the medical field is crucial for meeting the healthcare needs of a progressively diverse society. A diverse physician workforce enables culturally sensitive care, promotes health equity, and enhances the comprehension of the various needs and viewpoints of patients, ultimately resulting in more effective treatments and improved patient outcomes. However, despite the recognized benefits of diversity in the medical field, certain specialties, such as Radiology, have struggled to achieve adequate equity, diversity and inclusion, which results in a discrepancy in the demographics of Canadian radiologists and the patients we serve. In this review, we propose strategies from a committee within the Canadian Association of Radiologists (CAR) EDI working group to improve EDI in the CaRMS selection process. By adopting these strategies, residency programs can foster a more diverse and inclusive environment that is better positioned to address the health needs of a progressively diverse patient population, leading to improved patient outcomes, greater patient satisfaction, and advancements in medical innovation.

Objectives To assess the concordance of whole-body MRI (WB-MRI) and an FDG-PET/CT-based reference standard for the initial staging in children with Hodgkin lymphoma (HL) Methods Children with newly diagnosed HL were included in this prospective, multicentre, international study and underwent WB-MRI and FDG-PET/CT at staging. Two radiologists and a nuclear medicine physician independently evaluated all images. Discrepancies between WB-MRI and FDG-PET/CT were assessed by an expert panel. All FDG-PET/CT errors were corrected to derive the FDG-PET/CT-based reference standard. The expert panel corrected all reader errors in the WB-MRI DWI dataset to form the intrinsic MRI data. Inter-observer agreement for WB-MRI DWI was calculated using overall agreement, specific agreements and kappa statistics. Concordance for correct classification of all disease sites and disease stage between WB-MRI (without DWI, with DWI and intrinsic WB-MRI DWI) and the reference standard was calculated as primary outcome. Secondary outcomes included positive predictive value, negative predictive value and kappa statistics. Clustering within patients was accounted for using a mixed-effect logistic regression model with random intercepts and a multilevel kappa analysis. Results Sixty-eight children were included. Inter-observer agreement between WB-MRI DWI readers was good for disease stage (κ = 0.74). WB-MRI DWI agreed with the FDG-PET/CT-based reference standard for determining disease stage in 96% of the patients versus 88% for WB-MRI without DWI. Agreement between WB-MRI DWI and the reference standard was excellent for both nodal (98%) and extra-nodal (100%) staging. Conclusions WB-MRI DWI showed excellent agreement with the FDG-PET/CT-based reference standard. The addition of DWI to the WB-MRI protocol improved the staging agreement. Key Points • This study showed excellent agreement between WB-MRI DWI and an FDG-PET/CT-based reference standard for staging paediatric HL. • Diffusion-weighted imaging is a useful addition to WB-MRI in staging paediatric HL. • Inter-observer agreement for WB-MRI DWI was good for both nodal and extra-nodal staging and determining disease stage.

The petrous apex (PA) is involved in a myriad of pathological conditions, some of which are exclusive in children. Diagnosis may be difficult due to vague clinical presentation, and local examination is challenging owing to its inaccessible location. This is further complicated by multiple unfused sutures and ongoing PA pneumatization in children. Cross-sectional imaging is vital for the evaluation of the PA lesions, due to their precarious location and proximity to the major neurovascular structures. Several classification systems have been proposed for these lesions based on their site of origin, solid or cystic appearance, surgical or non-surgical (no touch lesions) management, and benign or malignant nature. In this article, we emphasize the distinctive role of different cross-sectional imaging modalities in the diagnosis of pediatric PA lesions, with special attention to normal variants that should not be mistaken for pathology. We also propose a radiological classification and algorithmic approach to aid in the precise diagnosis and facilitate appropriate management of the various PA lesions in children.

Purpose: It has been shown that oral contrast does not improve the diagnostic accuracy of Computed Tomography (CT) for appendicitis in pediatric patients; however, the cohorts in these studies were not stratified by weight or body mass index. The purpose of this study is to assess the benefit of oral contrast administration for identifying the appendix in younger children in the lower weight quartile. Materials and Methods: This retrospective study comprised 100 patients (2–10 years) in lower weight quartile who had intravenous contrast-enhanced CT of the abdomen and pelvis, 37 of which with oral contrast, and 63 without. A pediatric radiologist and a pediatric radiology fellow independently assessed whether the appendix was visualized or not. In case of discrepancy, an additional pediatric radiologist was the “tie-breaker.” Chi-squared test was used to compare the proportion of visualized appendix between the groups (with and without oral contrast). Inter-rater reliability was determined using Cohen’s Kappa coefficient. Results: There was no significant difference in the visualization of the appendix between the group with oral contrast and without ( P = 1). The Cohen Kappa coefficients were .33 (.05, .62) and .91 (.73, 1.00) for the “no oral” and “oral” groups, respectively, yielding evidence of a difference ( P = .007). Conclusions: There was no significant difference in the visualization of the appendix using CT with or without oral contrast in low-weight pediatric patients. The inter-rater reliability, however, was significantly higher in the group given oral contrast. Additional studies assessing the value of oral contrast for the sole indication of appendicitis may provide clearer results.

OBJECTIVE: To determine the relative importance weights of items and grades of a newly developed additive outcome measure called the juvenile idiopathic arthritis (JIA) magnetic resonance imaging (MRI) scoring system for the temporomandibular joint (TMJ) (JAMRIS-TMJ). METHODS: An adaptive partial-profile, discrete choice experiment (DCE) survey using the 1000Minds platform was independently completed by members of an expert group consisting of radiologists and non-radiologist clinicians to determine the group-averaged relative weights for the JAMRIS-TMJ. Subsequently, an image-based vignette ranking exercise was done, during which experts individually rank ordered 14 patient vignettes for disease severity while blinded to the weights and unrestricted to JAMRIS-TMJ assessment criteria. Validity of the weighted JAMRIS-TMJ was tested by comparing the consensus-graded, DCE-weighted JAMRIS-TMJ score of the vignettes with their unrestricted image-based ranks provided by the experts. RESULTS: Nineteen experts completed the DCE survey, and 21 completed the vignette ranking exercise. Synovial thickening and joint enhancement showed higher weights per raw score compared to bone marrow items and effusion in the inflammatory domain, while erosions and condylar flattening showed nonlinear and higher weights compared to disk abnormalities in the damage domain. The weighted JAMRIS-TMJ score of the vignettes correlated highly with the ranks from the unrestricted comparison method, with median Spearman's ? of 0.92 (interquartile range [IQR] 0.87-0.95) for the inflammation and 0.93 (IQR 0.90-0.94) for the damage domain. CONCLUSION: A DCE survey was used to quantify the importance weights of the items and grades of the JAMRIS-TMJ. The weighted score showed high convergent validity with an unrestricted, holistic vignette ranking method.

Purpose: The aim of our study was to compare whole-body diffusion-weighted MRI (WB-DWI-MRI) to fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the assessment of initial staging and treatment response in pediatric patients with Hodgkin lymphoma. Materials and Methods: This prospective study comprised 11 children with Hodgkin lymphoma. Whole-body DWI-MRI and FDG-PET/CT were obtained at baseline and after 2 cycles of chemotherapy. Two radiologists measured the apparent diffusion coefficient (ADC) values of the sites of involvement agreed upon in consensus and 1 nuclear medicine physician assessed the PET/CT. Reliability of radiologists’ ratings was assessed by intraclass correlation coefficients (ICC2,1). The sensitivity and positive predictive value (PPV) of DW-MRI relative to PET/CT were calculated for nodal and extranodal sites. The patients were staged according to both modalities. Association of treatment responses was assessed through the Pearson correlation between the ADC ratios and the change standardized uptake value (SUV) between baseline and follow-up. Results: There was good agreement between the raters for nodal and extranodal ADC measurements. The sensitivity and PPV of DW-MRI relative to PET/CT of nodal disease was 0.651 and 1.0, respectively, at baseline, and 0.697 and 0.885 at follow-up. The sensitivity and PPV of extranodal disease were 0.545 and 0.6 at baseline, and 0.167 and 0.333 at follow-up. Diffusion-weighted MRI determined correct tumor stage in 8 of 11 examinations. There was poor correlation between the ADC ratios and the absolute change in SUV between baseline and follow-up (0.348). Conclusion: Our experience showed that WB-DWI-MRI is inferior to PET/CT for initial staging and assessment of treatment response of Hodgkin lymphoma in pediatric patients.

The pediatric reproductive organs are optimally imaged with a full bladder. The filling of the bladder, however, often leads to significant delay in diagnosis and can subject the patient to invasive bladder catheterization. As the key imaging feature in ovarian torsion is unilateral ovarian enlargement, we suspected that a torsed ovary is large enough to be visualized even if the bladder is not well distended. The purpose of this study was to retrospectively investigate if clinically suspected adnexal torsion can be excluded based on non-visualization of the ovaries on transabdominal ultrasound (US) with a non-distended bladder in pediatric patients. This retrospective study comprised 349 girls (1–19 years old) between Jan. 1, 2013, and July 30, 2018. Three hundred and forty-one of the girls were referred to transabdominal US to assess for adnexal torsion and/or appendicitis, and the ovaries were initially not visualized on US. Their bladders were subsequently filled and rescanned with a distended bladder showing the ovaries. Ovarian volumes and time between US scans were documented. The ratio of the volume of the larger ovary to the smaller one was calculated. Nine girls had surgically proven adnexal torsion and a preoperative transabdominal US with a non-distended bladder. There was an overlap of one girl between the two groups. The negative predictive value (NPV), positive predictive value (PPV), and sensitivity and specificity for exclusion of adnexal torsion based on non-visualization of the ovaries on US with a non-distended bladder were calculated. One of the girls (1/341) who had a US study done with a non-distended bladder in which the ovaries were not visualized had a positive diagnosis of adnexal torsion. In eight of the nine girls who had surgically proven adnexal torsion, the torted ovary was identified with a non-distended bladder. The NPV and PPV for exclusion of adnexal torsion with a non-distended bladder was 1.0 and 0.8, respectively. The specificity and sensitivity were 99.4% and 88.9%, respectively. The mean and median time difference between the initial scan and the scan after bladder filling was 105.1 min (standard deviation [SD] -65.8) and 89.0 min (interquartile range [IQR]- 59.0, 130.5), respectively. Non-visualization of the ovaries with a non-distended bladder on transabdominal US study can help exclude clinically suspected adnexal torsion, alleviating the need for bladder filling and prolonging the wait time in the emergency department. Inclusion of non-visualization of the ovaries as one of the features in a predictive score for adnexal torsion should be considered.

Autosomal dominant Dandy-Walker malformation and occipital cephalocele (ADDWOC) is a rare, congenital, and incompletely penetrant malformation that is considered to be part of the Dandy-Walker spectrum of disorders. Affected individuals often present with an occipital cephalocele with a bony skull defect, but typically have normal neurological development. Here, we report on a three-generation family in which individuals have variable phenotypes that are consistent with the ADDWOC spectrum: arachnoid cysts in the proband and his maternal grandfather, an occipital cephalocele in the proband and his brother, and a small bony defect in the proband's mother. Whole exome sequencing identified a rare heterozygous variant in NID1 (NM_002508.2:c.1162C>T, (p.Gln388Ter)) in the proband, his brother, and his mother. Sanger sequencing confirmed the presence of this variant in the maternal grandfather. The identical c.1162C>T variant was previously identified in variably affected members of a three-generation family with ADDWOC. This case report provides further evidence that variants in NID1 may be clinically relevant for the development of a phenotype that is consistent with ADDWOC, and extends the phenotype of NID1-associated ADDWOC to include arachnoid cysts. Given that the Dandy-Walker malformation itself is not a pre-requisite to this spectrum of phenotypes, we also suggest a novel term for the NID1-associated disorder in order to give emphasis to this phenotypic variability: "Autosomal Dominant Posterior Fossa Anomalies with Occipital Cephaloceles."

Timely, accurate and reliable assessment of fetal brain development is essential to reduce short and long-term risks to fetus and mother. Fetal MRI is increasingly used for fetal brain assessment. Three key biometric linear measurements important for fetal brain evaluation are Cerebral Biparietal Diameter (CBD), Bone Biparietal Diameter (BBD), and Trans-Cerebellum Diameter (TCD), obtained manually by expert radiologists on reference slices, which is time consuming and prone to human error. The aim of this study was to develop a fully automatic method computing the CBD, BBD and TCD measurements from fetal brain MRI. The input is fetal brain MRI volumes which may include the fetal body and the mother's abdomen. The outputs are the measurement values and reference slices on which the measurements were computed. The method, which follows the manual measurements principle, consists of five stages: 1) computation of a Region Of Interest that includes the fetal brain with an anisotropic 3D U-Net classifier; 2) reference slice selection with a Convolutional Neural Network; 3) slice-wise fetal brain structures segmentation with a multiclass U-Net classifier; 4) computation of the fetal brain midsagittal line and fetal brain orientation, and; 5) computation of the measurements. Experimental results on 214 volumes for CBD, BBD and TCD measurements yielded a mean $L_1$ difference of 1.55mm, 1.45mm and 1.23mm respectively, and a Bland-Altman 95% confidence interval ($CI_{95}$) of 3.92mm, 3.98mm and 2.25mm respectively. These results are similar to the manual inter-observer variability. The proposed automatic method for computing biometric linear measurements of the fetal brain from MR imaging achieves human level performance. It has the potential of being a useful method for the assessment of fetal brain biometry in normal and pathological cases, and of improving routine clinical practice., 15 pages, 8 figures, presented in CARS 2020, submitted to IJCARS

Prenatal ultrasound (US) is the first prenatal imaging tool for screening and evaluation of posterior fossa malformations since it is noninvasive, widely available, and safe for both mother and child. Fetal MRI is a widely used secondary technique to confirm, correct, or complement questionable US findings and plays an essential role in evaluating fetuses with suspected US findings and /or positive family history. The main sequences of fetal MRI consist of T2-weighted (T2w) ultrafast, single-shot sequences. Axial, coronal, and sagittal images are typically acquired allowing for a detailed evaluation of the posterior fossa contents. Also, various complimentary sequences, such as T1w, T2*w gradient sequences, or advanced techniques, including diffusion-weighted imaging, diffusion tensor imaging, and magnetic resonance spectroscopy, may provide additional information based on the studied malformation. Inclusion of these techniques should be done with careful risk-benefit analysis. The use of fetal MRI also aims to evaluate for associated anomalies. In addition, prenatal diagnosis of posterior fossa malformations is still a challenge but advances in knowledge in human developmental anatomy, genetic, and imaging recognition patterns have enabled us to shed some light on prognostic information that will help with the counseling of families. Finally, high-resolution late third trimester fetal MRI offers a safe alternative to early postnatal MR imaging, basically taking advantage of the uterine environment as a kind of "maternal incubator." Our goal is to discuss the spectrum of prenatal posterior fossa pathologies that can be studied by fetal MRI and their key neuroimaging features.

Objectives To compare WB-MRI with an [18F]FDG-PET/CT-based reference for early response assessment and restaging in children with Hodgkin’s lymphoma (HL). Methods Fifty-one children (ages 10–17) with HL were included in this prospective, multicentre study. All participants underwent WB-MRI and [18F]FDG-PET/CT at early response assessment. Thirteen of the 51 patients also underwent both WB-MRI and [18F]FDG-PET/CT at restaging. Two radiologists independently evaluated all WB-MR images in two separate readings: without and with DWI. The [18F]FDG-PET/CT examinations were evaluated by a nuclear medicine physician. An expert panel assessed all discrepancies between WB-MRI and [18F]FDG-PET/CT to derive the [18F]FDG-PET/CT-based reference standard. Inter-observer agreement for WB-MRI was calculated using kappa statistics. Concordance, PPV, NPV, sensitivity and specificity for a correct assessment of the response between WB-MRI and the reference standard were calculated for both nodal and extra-nodal disease presence and total response evaluation. Results Inter-observer agreement of WB-MRI including DWI between both readers was moderate (κ 0.46–0.60). For early response assessment, WB-MRI DWI agreed with the reference standard in 33/51 patients (65%, 95% CI 51–77%) versus 15/51 (29%, 95% CI 19–43%) for WB-MRI without DWI. For restaging, WB-MRI including DWI agreed with the reference standard in 9/13 patients (69%, 95% CI 42–87%) versus 5/13 patients (38%, 95% CI 18–64%) for WB-MRI without DWI. Conclusions The addition of DWI to the WB-MRI protocol in early response assessment and restaging of paediatric HL improved agreement with the [18F]FDG-PET/CT-based reference standard. However, WB-MRI remained discordant in 30% of the patients compared to standard imaging for assessing residual disease presence. Key Points • Inter-observer agreement of WB-MRI including DWI between both readers was moderate for (early) response assessment of paediatric Hodgkin’s lymphoma. • The addition of DWI to the WB-MRI protocol in early response assessment and restaging of paediatric Hodgkin’s lymphoma improved agreement with the [18F]FDG-PET/CT-based reference standard. • WB-MRI including DWI agreed with the reference standard in respectively 65% and 69% of the patients for early response assessment and restaging. Supplementary Information The online version contains supplementary material available at 10.1007/s00330-021-08026-1.

BACKGROUND AND PURPOSE: The superior diagnostic accuracy of fetal MR imaging in detecting fetal brain abnormalities has been previously demonstrated; however, the ability of fetal MR imaging to prognosticate postnatal outcome is not well-studied. We performed a retrospective analysis to determine the prognostic accuracy of fetal MR imaging in predicting postnatal neurodevelopmental outcome. MATERIALS AND METHODS: We identified all fetal MR imaging performed at the Children9s Hospital of Eastern Ontario during a 10-year period and assessed agreement between prenatal prognosis and postnatal outcome. Prenatal prognosis was determined by a pediatric neurologist who reviewed the fetal MR imaging report and categorized each pregnancy as having a favorable, indeterminate, or poor prognosis. Assessment of postnatal neurodevelopmental outcome was made solely on the basis of the child’s Gross Motor Function Classification System score and whether the child developed epilepsy. Postnatal outcome was categorized as favorable, intermediate, or poor. We also assessed the diagnostic accuracy of fetal MR imaging by comparing prenatal and postnatal imaging diagnoses. RESULTS: We reviewed 145 fetal MR images: 114 were included in the assessment of diagnostic accuracy, and 104 were included in the assessment of prognostic accuracy. There was 93.0% agreement between prenatal and postnatal imaging diagnoses. Prognosis was favorable in 44.2%, indeterminate in 50.0%, and poor in 5.8% of pregnancies. There was 93.5% agreement between a favorable prenatal prognosis and a favorable postnatal outcome. CONCLUSIONS: A favorable prenatal prognosis is highly predictive of a favorable postnatal outcome. Further studies are required to better understand the role of fetal MR imaging in prognosticating postnatal development, particularly in pregnancies with indeterminate and poor prognoses.

This dataset is composed of annotations of the five hemorrhage subtypes (subarachnoid, intraventricular, subdural, epidural, and intraparenchymal hemorrhage) typically encountered at brain CT.

The aim of our study was to compare whole-body diffusion-weighted MRI (WB-DWI-MRI) to fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the assessment of initial staging and treatment response in pediatric patients with Hodgkin lymphoma.This prospective study comprised 11 children with Hodgkin lymphoma. Whole-body DWI-MRI and FDG-PET/CT were obtained at baseline and after 2 cycles of chemotherapy. Two radiologists measured the apparent diffusion coefficient (ADC) values of the sites of involvement agreed upon in consensus and 1 nuclear medicine physician assessed the PET/CT. Reliability of radiologists' ratings was assessed by intraclass correlation coefficients (ICCThere was good agreement between the raters for nodal and extranodal ADC measurements. The sensitivity and PPV of DW-MRI relative to PET/CT of nodal disease was 0.651 and 1.0, respectively, at baseline, and 0.697 and 0.885 at follow-up. The sensitivity and PPV of extranodal disease were 0.545 and 0.6 at baseline, and 0.167 and 0.333 at follow-up. Diffusion-weighted MRI determined correct tumor stage in 8 of 11 examinations. There was poor correlation between the ADC ratios and the absolute change in SUV between baseline and follow-up (0.348).Our experience showed that WB-DWI-MRI is inferior to PET/CT for initial staging and assessment of treatment response of Hodgkin lymphoma in pediatric patients.

Cranial US allows for the evaluation of premature closure (synostosis) or abnormal widening of the cranial sutures. An understanding of the normal anatomy is required to help define the presence or absence of abnormality. To provide reference for normal ultrasound measurements of cranial sutures during the child’s first year. We included children ages 0 to 12 months who were referred to the hospital during 2011–2013 for radiographic evaluation of cranial sutures. Cranial US study was focused on evaluating the sagittal, coronal, lambdoid and metopic sutures. We measured the hypoechoic gap between the bones (patent suture). Two readers performed the measurements, blinded to clinical indications and previous reports. Estimates of the 10th, 25th, 50th, 75th and 90th percentiles were achieved for ages 1–12 months. Of 129 children whose families consented to cranial US, 11 were excluded because of craniosynostosis and 3 for suboptimal quality of cranial US images. In 115 patients measurements of normal cranial sutures were obtained (75 boys [65%], ages 0.26–11.27 months). For each suture, the suture size decreased significantly with age (P

Contrast-enhanced magnetic resonance imaging (MRI) remains the most comprehensive modality to assess juvenile idiopathic arthritis (JIA)-related inflammation and osteochondral damage in the temporomandibular joints (TMJ). This study tested the reliability of a new JIA MRI scoring system for TMJ (JAMRIS-TMJ) and the impact of variations in calibration and reader specialty. Thirty-one MRI exams of bilateral TMJs were scored independently using the JAMRIS-TMJ by 20 readers consisting of radiologists and non-radiologist clinicians in three reading groups, with or without a calibrating atlas and/or tutorial. The inter-reader reliability in the multidisciplinary cohort assessed by the generalizability coefficient was 0.61–0.67 for the inflammatory and 0.66–0.74 for the damage domain. The atlas and tutorial did not improve agreement within radiologists, but improved the agreement between radiologist and non-radiologist groups. Agreements between different calibration levels were 0.02 to 0.08 lower by the generalizability coefficient compared to agreement within calibration levels, agreement between specialty groups was 0.04 to 0.10 lower than within specialty groups. Averaging two radiologists raised the reliability above 0.8 for both domains. Therefore, the reliability of JAMRIS-TMJ was moderate-to-good depending on the presence of specialty and calibration differences. The atlas and tutorial are necessary to improve reliability when the reader cohort consists of multiple specialties.

Occipital cortical malformation is a rare neurodevelopmental disorder characterized by pachygyria and polymicrogyria of the occipital lobes as well as global developmental delays and seizures. This condition is due to biallelic, loss-of-function mutations in LAMC3 and has been reported in four unrelated families to date. We report an individual with global delays, seizures, and polymicrogyria that extends beyond the occipital lobes and includes the frontal, parietal, temporal, and occipital lobes. Next-generation sequencing identified a homozygous nonsense mutation in LAMC3: c.3190C>T (p.Gln1064*). This finding extends the cortical phenotype associated with LAMC3 mutations.

Background: Accurate fetal brain volume estimation is of paramount importance in evaluating fetal development. The aim of this study was to develop an automatic method for fetal brain segmentation from magnetic resonance imaging (MRI) data, and to create for the first time a normal volumetric growth chart based on a large cohort. Subjects and Methods: A semi-automatic segmentation method based on Seeded Region Growing algorithm was developed and applied to MRI data of 199 typically developed fetuses between 18 and 37 weeks' gestation. The accuracy of the algorithm was tested against a sub-cohort of ground truth manual segmentations. A quadratic regression analysis was used to create normal growth charts. The sensitivity of the method to identify developmental disorders was demonstrated on 9 fetuses with intrauterine growth restriction (IUGR). Results: The developed method showed high correlation with manual segmentation (r2 = 0.9183, p < 0.001) as well as mean volume and volume overlap differences of 4.77 and 18.13%, respectively. New reference data on 199 normal fetuses were created, and all 9 IUGR fetuses were at or below the third percentile of the normal growth chart. Discussion: The proposed method is fast, accurate, reproducible, user independent, applicable with retrospective data, and is suggested for use in routine clinical practice.

Aims: To compare changes in gross motor skills and functional mobility between ambulatory children with cerebral palsy who underwent a 1-week clinic-based virtual reality intervention (VR) followed by a 6-week, therapist-monitored home active video gaming (AVG) program and children who completed only the 6-week home AVG program. Methods: Pilot non-randomized controlled trial. Five children received 1 hour of VR training for 5 days followed by a 6-week home AVG program, supervised online by a physical therapist. Six children completed only the 6-week home AVG program. The Gross Motor Function Measure Challenge Module (GMFM-CM) and Six Minute Walk Test (6MWT) evaluated change. Results: There were no significant differences between groups. The home AVG-only group demonstrated a statistically and clinically significant improvement in GMFM-CM scores following the 6-week AVG intervention (median difference 4.5 points, interquartile range [IQR] 4.75, p = 0.042). The VR + AVG group demonstrated a statistically and clinically significant decrease in 6MWT distance following the intervention (median decrease 68.2 m, IQR 39.7 m, p = 0.043). All 6MWT scores returned to baseline at 2 months post-intervention. Conclusion: Neither intervention improved outcomes in this small sample. Online mechanisms to support therapist-child communication for exercise progression were insufficient to individualize exercise challenge.

Objectives Diprosopus is a rare subtype of conjoined twinning, with approximately 30 reported cases in English literature. Due to the rarity of conjoined twins, the mechanism leading to this developmental anomaly is not yet understood. Case presentation We present a case of diprosopus with multimodality imaging (prenatal and postnatal), and with pathological correlations. Developmental anomalies include partial duplication of frontal lobes, formation of a midline “third” frontal lobe, as well as orofacial and cardiac anomalies. The constellation of anomalies coincide with development during embryonic days 23–26, where the anterior prosencephalon, prechordal plate/oropharyngeal membrane, and cardiogenic plate are in very close proximity to each other. Conclusions This case offers an opportunity to better appreciate the radiologic and pathologic manifestations of diprosopus, and adds to the current body of evidence.

Hypomyelinating leukodystrophy with hypodontia and hypogonadotropic hypogonadism (4H leukodystrophy), also known as POLR3-related leukodystrophy, is a genetic disorder caused by autosomal recessive mutations in the POLR3A , POLR3B , POLR1C , or POLR3K genes.1–3 Most patients have progressive motor deficits.4 We present 2 siblings with a milder phenotype and lack of disease progression previously reported within a larger cohort of patients.5

Postmortem CT for investigating childhood deaths is increasingly utilised as a noninvasive adjunct or alternative to standard autopsy; however there are no standardised published imaging protocols. This article describes a standardised imaging protocol that has been developed based on current practices of international postmortem imaging practitioners and experts. This recommendation is expected to be useful for postmortem imaging centres wishing to update their existing practices and for those starting paediatric postmortem CT as a new service.