Multi-channel attention-fusion neural network for brain age estimation: Accuracy, generality, and interpretation with 16,705 healthy MRIs across lifespan.

Brain age estimated by machine learning from T1-weighted magnetic resonance images (T1w MRIs) can reveal how brain disorders alter brain aging and can help in the early detection of such disorders. A fundamental step is to build an accurate age estimator from healthy brain MRIs. We focus on this step, and propose a framework to improve the accuracy, generality, and interpretation of age estimation in healthy brain MRIs. For accuracy, we used one of the largest sample sizes (N = 16,705). For each subject, our proposed algorithm first explicitly splits the T1w image, which has been commonly treated as a single-channel 3D image in other studies, into two 3D image channels representing contrast and morphometry information. We further proposed a "fusion-with-attention" deep learning convolutional neural network (FiA-Net) to learn how to best fuse the contrast and morphometry image channels. FiA-Net recognizes varying contributions across image channels at different brain anatomy and different feature layers. In contrast, multi-channel fusion does not exist for brain age estimation, and is mostly attention-free in other medical image analysis tasks (e.g., image synthesis, or segmentation), where treating channels equally may not be optimal. For generality, we used lifespan data 0-97 years of age for real-world utility; and we thoroughly tested FiA-Net for multi-site and multi-scanner generality by two phases of cross-validations in discovery and replication data, compared to most other studies with only one phase of cross-validation. For interpretation, we directly measured each artificial neuron's correlation with the chronological age, compared to other studies looking at the saliency of features where salient features may or may not predict age. Overall, FiA-Net achieved a mean absolute error (MAE) of 3.00 years and Pearson correlation r=0.9840 with known chronological ages in healthy brain MRIs 0-97 years of age, comparing favorably with state-of-the-art algorithms and studies for accuracy and generality across sites and datasets. We also provided interpretations on how different artificial neurons and real neuroanatomy contribute to the age estimation.

Success of Nonsedated Neuroradiologic MRI in Children 1-7 Years Old.

BACKGROUND. MRI use and the need for monitored anesthesia care (MAC) in children have increased. However, MAC is associated with examination delays, increased cost, and safety concerns. OBJECTIVE. The purpose of this study was to evaluate the success rate of nonsedated neuroradiologic MRI studies in children 1-7 years old and to investigate factors associated with success. METHODS. We retrospectively reviewed data from our institutional nonsedated MRI program. Inclusion criteria were outpatient nonsedated MRI referral, age 1-7 years old, and neuroradiologic indication. Exclusion criteria were MRI examinations for ventricular checks and contrast material use. Success was determined by reviewing the clinical MRI report. We recorded patient age and sex, type of MRI examination (brain, spine, craniospinal, head and neck, and brain with MRA), protocol length, presence of child life specialist, video goggle use, and MRI appointment time (routine daytime appointment or evening appointment). We used descriptive statistics to summarize patient demographics and clinical data and logistic regression models to evaluate predictors of success in the entire sample. Subset analyses were performed for children from 1 to < 3 years old and 3 to 7 years old. RESULTS. We analyzed 217 patients who underwent nonsedated MRI examinations (median age, 5.1 years). Overall success rate was 82.0% (n = 178). The success rates were 81.4% (n = 127) for brain, 90.3% (n = 28) for spine, 71.4% (n = 10) for craniospinal, 66.7% (n = 6) for head and neck, and 100% (n = 7) for brain with MRA. Age was significantly associated with success (odds ratio [OR], 1.33; p = .009). In children 1 to < 3 years old, none of the factors analyzed were significant predictors of success (all, p > .48). In children 3-7 years old, protocol duration (OR, 0.96; 95% CI, 0.93-0.99; p = .02) and video goggle use (OR, 6.38; 95% CI, 2.16-18.84; p = .001) were significantly associated with success. CONCLUSION. A multidisciplinary approach with age-appropriate resources enables a high success rate for nonsedated neuroradiologic MRI in children 1-7 years old. CLINICAL IMPACT. Using age as the primary criterion to determine the need for MAC may lead to overuse of these services. Dissemination of information regarding nonsedated MRI practice could reduce the rate of sedated MRI in young children.

BRAIN AGE ESTIMATION USING LSTM ON CHILDREN'S BRAIN MRI.

Brain age prediction based on children's brain MRI is an important biomarker for brain health and brain development analysis. In this paper, we consider the 3D brain MRI volume as a sequence of 2D images and propose a new framework using the recurrent neural network for brain age estimation. The proposed method is named as 2D-ResNet18+Long short-term memory (LSTM), which consists of four parts: 2D ResNet18 for feature extraction on 2D images, a pooling layer for feature reduction over the sequences, an LSTM layer, and a final regression layer. We apply the proposed method on a public multisite NIH-PD dataset and evaluate generalization on a second multisite dataset, which shows that the proposed 2D-ResNet18+LSTM method provides better results than traditional 3D based neural network for brain age estimation.

ACR Appropriateness Criteria® Head Trauma-Child.

Head trauma is a frequent indication for cranial imaging in children. The majority of accidental pediatric head trauma is minor and sustained without intracranial injury. Well-validated pediatric-specific clinical decision guidelines should be used to identify very low-risk children who can safely forgo imaging. In those who require acute imaging, CT is considered the first-line imaging modality for suspected intracranial injury because of the short duration of the examination and its high sensitivity for acute hemorrhage. MRI can accurately detect traumatic complications, but often necessitates sedation in children, owing to the examination length and motion sensitivity, which limits rapid assessment. There is a paucity of literature regarding vascular injuries in pediatric blunt head trauma and imaging is typically guided by clinical suspicion. Advanced imaging techniques have the potential to identify changes that are not seen by standard imaging, but data are currently insufficient to support routine clinical use. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Cerebrovascular Disease-Child.

Stroke is an uncommon but an important and under-recognized cause of morbidity and mortality in children. Strokes may be due to either brain ischemia or intracranial hemorrhage. Common symptoms of pediatric acute stroke include headache, vomiting, focal weakness, numbness, visual disturbance, seizures, and altered consciousness. Most children presenting with an acute neurologic deficit do not have an acute stroke, but have symptoms due to stroke mimics which include complicated migraine, seizures with postictal paralysis, and Bell palsy. Because of frequency of stroke mimics, in children and the common lack of specificity in symptoms, the diagnosis of a true stroke may be delayed. There are a relatively large number of potential causes of stroke mimic and true stroke. Consequently, imaging plays a critical role in the assessment of children with possible stroke and especially in children who present with acute onset of stroke symptoms. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Prenatal diagnosis of intraconal lymphatic malformation on fetal magnetic resonance imaging.

Lymphatic malformations are benign hamartomatous tumors present at birth but usually diagnosed in early childhood. We report a case of prenatal diagnosis of an isolated unilateral retrobulbar lymphatic malformation with fetal magnetic resonance imaging (MRI). This was first detected at 27 weeks' gestational age. Postnatal ocular examinations at 4 days and 5 weeks of age showed no signs of optic nerve compromise. Postnatal MRI at 18 days of age showed slight increase in size of the lesion, and no intracranial vascular malformations were detected.

Diagnostic equivalency of fast T2 and FLAIR sequences for pediatric brain MRI: a pilot study.

BACKGROUND: Faster and motion robust magnetic resonance imaging (MRI) sequences are desirable in pediatric brain MRI as they can help reduce the need for monitored anesthesia care, which is a costly and limited resource that carries medical risks. OBJECTIVE: To evaluate the diagnostic equivalency of commercially available accelerated motion robust MR sequences relative to standard sequences. MATERIALS AND METHODS: This was an institutional review board-approved prospective study. Subjects underwent a clinical brain MRI using conventional multiplanar images at 3 Tesla followed by fast axial T2 and FLAIR (fluid-attenuated inversion recovery) sequences optimized for an approximately 50% reduction in acquisition time. Conventional and fast images from each subject were reviewed by two blinded pediatric neuroradiologists. The readers evaluated the presence of 12 findings. Intra-observer agreement was estimated for fast versus conventional sequences. For each set of sequences, interobserver agreement calculations and chi-square tests were used to evaluate differences between fast and conventional acquisitions. An independent third reader reviewed the intra-observer discrepancies and adjudicated them as being more conspicuous on fast sequence, conventional sequence or the equivalent. The readers also were asked to rate motion artifacts with a previously validated score. RESULTS: Images from 77 children (mean age: 11.3 years) were analyzed. Intra-observer agreement (fast versus conventional) ranged between 89.2% and 92.3%. Interobserver agreement ranged between 86.1% and 88.4%. Interobserver agreement was significantly higher for conventional FLAIR relative to fast FLAIR for small (<5 mm) foci of T2 in the white matter. Otherwise, interobserver agreement was not different between the fast and conventional sequences. For awake subjects, fast sequences had significantly fewer artifacts (P<0.05). CONCLUSION: Conventional T2 and FLAIR sequences can be optimized to shorten acquisition while maintaining diagnostic equivalency. These faster sequences were also less susceptible to motion artifacts.

ACR Appropriateness Criteria® Scoliosis-Child.

Scoliosis is frequently encountered in childhood, with prevalence of 2%. The majority is idiopathic, without vertebral segmentation anomaly, dysraphism, neuromuscular abnormality, skeletal dysplasia, tumor, or infection. As a complement to clinical assessment, radiography is the primary imaging modality used to classify scoliosis and subsequently monitor its progression and response to treatment. MRI is utilized selectively to assess for neural axis abnormalities in those at higher risk, including those with congenital scoliosis, early onset idiopathic scoliosis, and adolescent idiopathic scoliosis with certain risk factors. CT, although not routinely employed in the initial evaluation of scoliosis, may have a select role in characterizing the bone anomalies of congenital scoliosis and in perioperative planning. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Suspected Spine Trauma-Child.

Choosing the appropriate imaging in children with accidental traumatic spine injuries can be challenging because the recommendations based on scientific evidence at this time differ from those applied in adults. This differentiation is due in part to differences in anatomy and physiology of the developing spine. This publication uses scientific evidence and a panel of pediatric experts to summarize best current imaging practices for children with accidental spine trauma. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Markerless high-frequency prospective motion correction for neuroanatomical MRI.

PURPOSE: To integrate markerless head motion tracking with prospectively corrected neuroanatomical MRI sequences and to investigate high-frequency motion correction during imaging echo trains. METHODS: A commercial 3D surface tracking system, which estimates head motion by registering point cloud reconstructions of the face, was used to adapt the imaging FOV based on head movement during MPRAGE and T2 SPACE (3D variable flip-angle turbo spin-echo) sequences. The FOV position and orientation were updated every 6 lines of k-space (< 50 ms) to enable "within-echo-train" prospective motion correction (PMC). Comparisons were made with scans using "before-echo-train" PMC, in which the FOV was updated only once per TR, before the start of each echo train (ET). Continuous-motion experiments with phantoms and in vivo were used to compare these high-frequency and low-frequency correction strategies. MPRAGE images were processed with FreeSurfer to compare estimates of brain structure volumes and cortical thickness in scans with different PMC. RESULTS: The median absolute pose differences between markerless tracking and MR image registration were 0.07/0.26/0.15 mm for x/y/z translation and 0.06º/0.02º/0.12° for rotation about x/y/z. The PMC with markerless tracking substantially reduced motion artifacts. The continuous-motion experiments showed that within-ET PMC, which minimizes FOV encoding errors during ETs that last over 1 second, reduces artifacts compared with before-ET PMC. T2 SPACE was found to be more sensitive to motion during ETs than MPRAGE. FreeSurfer morphometry estimates from within-ET PMC MPRAGE images were the most accurate. CONCLUSION: Markerless head tracking can be used for PMC, and high-frequency within-ET PMC can reduce sensitivity to motion during long imaging ETs.

ACR Appropriateness Criteria® Sinusitis-Child.

Sinusitis is common in children that usually resolves spontaneously. Imaging is not part of the standard of care for initial diagnosis, however may be necessary in cases with persistent or chronic sinusitis to guide surgical intervention, or to rule out intracranial and vascular complications of sinusitis. Computed tomography (CT) and magnetic resonance imaging (MRI) are the leading imaging modalities. In this article, appropriateness in use of imaging modalities are discussed under common/clinically relevant scenarios. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Headache-Child.

Headaches in children are not uncommon and have various causes. Proper neuroimaging of these children is very specific to the headache type. Care must be taken to choose and perform the most appropriate initial imaging examination in order to maximize the ability to properly determine the cause with minimum risk to the child. This evidence-based report discusses the different headache types in children and provides appropriate guidelines for imaging these children. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Correction to: Ionizing radiation from computed tomography versus anesthesia for magnetic resonance imaging in infants and children: patient safety considerations.

The published version of this article incorrectly lists Dr. Joseph P. Cravero in the Department of Radiology at Boston Children's Hospital. Dr. Cravero's correct affiliation is given below.

Ionizing radiation from computed tomography versus anesthesia for magnetic resonance imaging in infants and children: patient safety considerations.

In the context of health care, risk assessment is the identification, evaluation and estimation of risk related to a particular clinical situation or intervention compared to accepted medical practice standards. The goal of risk assessment is to determine an acceptable level of risk for a given clinical treatment or intervention in association with the provided clinical circumstances for a patient or group of patients. In spite of the inherent challenges related to risk assessment in pediatric cross-sectional imaging, the potential risks of ionizing radiation and sedation/anesthesia in the pediatric population are thought to be quite small. Nevertheless both issues continue to be topics of discussion concerning risk and generate significant anxiety and concern for patients, parents and practicing pediatricians. Recent advances in CT technology allow for more rapid imaging with substantially lower radiation exposures, obviating the need for anesthesia for many indications and potentially mitigating concerns related to radiation exposure. In this review, we compare and contrast the potential risks of CT without anesthesia against the potential risks of MRI with anesthesia, and discuss the implications of this analysis on exam selection, providing specific examples related to neuroblastoma surveillance imaging.

Quality measures and pediatric radiology: suggestions for the transition to value-based payment.

Recent political and economic factors have contributed to a meaningful change in the way that quality in health care, and by extension value, are viewed. While quality is often evaluated on the basis of subjective criteria, pay-for-performance programs that link reimbursement to various measures of quality require use of objective and quantifiable measures. This evolution to value-based payment was accelerated by the 2015 passage of the Medicare Access and CHIP (Children's Health Insurance Program) Reauthorization Act (MACRA). While many of the drivers of these changes are rooted in federal policy and programs such as Medicare and aimed at adult patients, the practice of pediatrics and pediatric radiology will be increasingly impacted. This article addresses issues related to the use of quantitative measures to evaluate the quality of services provided by the pediatric radiology department or sub-specialty section, particularly as seen from the viewpoint of a payer that may be considering ways to link payment to performance. The paper concludes by suggesting a metric categorization strategy to frame future work on the subject.

ACR Appropriateness Criteria® Back Pain-Child.

It is now generally accepted that nontraumatic back pain in the pediatric population is common. The presence of isolated back pain in a child has previously been an indication for imaging; however, recently a more conservative approach has been suggested using clinical criteria. The presence of constant pain, night pain, and radicular pain, alone or in combination, lasting for 4 weeks or more, constitute clinical red flags that should prompt further imaging. Without these clinical red flags, imaging is likely not indicated. Exceptions include an abnormal neurologic examination or clinical and laboratory findings suggesting an infectious or neoplastic etiology, and when present should prompt immediate imaging. Initial imaging should consist of spine radiographs limited to area of interest, with spine MRI without contrast to evaluate further if needed. CT of the spine, limited to area of interest, and Tc-99m bone scan whole body with single-photon emission computed tomography may be useful in some patients. The addition of intravenous contrast is also recommended for evaluation of a potential neoplastic or infectious process. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Quality of pediatric abdominal CT scans performed at a dedicated children's hospital and its referring institutions: a multifactorial evaluation.

BACKGROUND: Pediatric patients requiring transfer to a dedicated children's hospital from an outside institution may undergo CT imaging as part of their evaluation. Whether this imaging is performed prior to or after transfer has been shown to impact the radiation dose imparted to the patient. Other quality variables could also be affected by the pediatric experience and expertise of the scanning institution. OBJECTIVE: To identify differences in quality between abdominal CT scans and reports performed at a dedicated children's hospital, and those performed at referring institutions. MATERIALS AND METHODS: Fifty consecutive pediatric abdominal CT scans performed at outside institutions were matched (for age, gender and indication) with 50 CT scans performed at a dedicated freestanding children's hospital. We analyzed the scans for technical parameters, report findings, correlation with final clinical diagnosis, and clinical utility. Technical evaluation included use of intravenous and oral contrast agents, anatomical coverage, number of scan phases and size-specific dose estimate (SSDE) for each scan. Outside institution scans were re-reported when the child was admitted to the children's hospital; they were also re-interpreted for this study by children's hospital radiologists who were provided with only the referral information given in the outside institution's report. Anonymized original outside institutional reports and children's hospital admission re-reports were analyzed by two emergency medicine physicians for ease of understanding, degree to which the clinical question was answered, and level of confidence in the report. RESULTS: Mean SSDE was lower (8.68) for children's hospital scans, as compared to outside institution scans (13.29, P = 0.03). Concordance with final clinical diagnosis was significantly lower for original outside institution reports (38/48, 79%) than for both the admission and study children's hospital reports (48/50, 96%; P = 0.005). Children's hospital admission reports were rated higher than outside institution reports for completeness, ease of understanding, answering of clinical question, and level of confidence of the report (P < 0.001). CONCLUSION: Pediatric abdominal CT scans performed and interpreted at a dedicated children's hospital are associated with higher technical quality, lower radiation dose and a more clinically useful report than those performed at referring institutions.

Neuroimaging of Children With Surgically Treated Hydrocephalus: A Practical Approach.

OBJECTIVE: Children with surgically treated hydrocephalus commonly undergo multiple neuroimaging studies. The purpose of this article is to share an experience with use of the as low as reasonably achievable (ALARA) principle to guide the imaging approach to these patients. CONCLUSION: A reasonably achievable strategy for minimizing ionizing radiation in patients with surgically treated hydrocephalus includes rapid-sequence MRI and judicious use of dose-optimized head CT. Rapid-sequence MRI is particularly useful in the care of patients who have undergone endoscopic third ventriculostomy.

Third Trimester Brain Growth in Preterm Infants Compared With In Utero Healthy Fetuses.

BACKGROUND AND OBJECTIVES: Compared with term infants, preterm infants have impaired brain development at term-equivalent age, even in the absence of structural brain injury. However, details regarding the onset and progression of impaired preterm brain development over the third trimester are unknown. Our primary objective was to compare third-trimester brain volumes and brain growth trajectories in ex utero preterm infants without structural brain injury and in healthy in utero fetuses. As a secondary objective, we examined risk factors associated with brain volumes in preterm infants over the third-trimester postconception. METHODS: Preterm infants born before 32 weeks of gestational age (GA) and weighing <1500 g with no evidence of structural brain injury on conventional MRI and healthy pregnant women were prospectively recruited. Anatomic T2-weighted brain images of preterm infants and healthy fetuses were parcellated into the following regions: cerebrum, cerebellum, brainstem, and intracranial cavity. RESULTS: We studied 205 participants (75 preterm infants and 130 healthy control fetuses) between 27 and 39 weeks' GA. Third-trimester brain volumes were reduced and brain growth trajectories were slower in the ex utero preterm group compared with the in utero healthy fetuses in the cerebrum, cerebellum, brainstem, and intracranial cavity. Clinical risk factors associated with reduced brain volumes included dexamethasone treatment, the presence of extra-axial blood on brain MRI, confirmed sepsis, and duration of oxygen support. CONCLUSIONS: These preterm infants exhibited impaired third-trimester global and regional brain growth in the absence of cerebral/cerebellar parenchymal injury detected by using conventional MRI.