Can QuickBrain MRI replace CT as first-line imaging for select pediatric head trauma?

Increasing Use of Rapid Magnetic Resonance Imaging for Children with Blunt Head Injury

OBJECTIVE

To increase the percentage of patients who undergo rapid magnetic resonance imaging (rMRI) rather than computed tomography (CT) for evaluation of mild traumatic brain injury (TBI) from 45% in 2020 to 80% by December 2021.

STUDY DESIGN

This was a quality improvement initiative targeted to patients presenting to the pediatric emergency department (ED) presenting with mild traumatic brain injury (TBI), with baseline data collected from January 2020 to December 2020. From January 2021 to August 2021 we implemented a series of improvement interventions and tracked the percentage of patients undergoing neuroimaging who received rMRI as their initial study. Balancing measures included proportion of all patients with mild TBI who underwent neuroimaging of any kind, proportion of patients requiring sedation, emergency department (ED) length of stay (LOS), and percentage with clinically important TBI.

RESULTS

The utilization of rMRI increased from a baseline of 45% to a mean of 92% in the intervention period. Overall neuroimaging rates did not change significantly after the intervention (19.8 vs 23.2%, p=0.24). There was no difference in need for anxiolysis (12 vs 7%, p=0.30) though ED LOS was marginally increased (1.4 vs 1.7 hours, p=<0.01).

CONCLUSION

In this quality improvement initiative, transition to rMRI as the primary imaging modality for the evaluation of minor TBI was achieved at a level 1 pediatric trauma center with no significant increase in overall use of neuroimaging.

Elective one-minute full brain multi-contrast MRI versus brain CT in pediatric patients: a prospective feasibility study

BACKGROUND

Brain CT can be used to evaluate pediatric patients with suspicion of cerebral pathology when anesthetic and MRI resources are scarce. This study aimed to assess if pediatric patients referred for an elective brain CT could endure a diagnostic fast brain MRI without general anesthesia using a one-minute multi-contrast EPI-based sequence (EPIMix) with comparable diagnostic performance.

METHODS

Pediatric patients referred for an elective brain CT between March 2019 and March 2020 were prospectively included and underwent EPIMix without general anesthesia in addition to CT. Three readers (R1-3) independently evaluated EPIMix and CT images on two separate occasions. The two main study outcomes were the tolerance to undergo an EPIMix scan without general anesthesia and its performance to classify a scan as normal or abnormal. Secondary outcomes were assessment of disease category, incidental findings, diagnostic image quality, diagnostic confidence, and image artifacts. Further, a side-by-side evaluation of EPIMix and CT was performed. The signal-to-noise ratio (SNR) was calculated for EPIMix on T1-weighted, T2-weighted, and ADC images. Descriptive statistics, Fisher's exact test, and Chi-squared test were used to compare the two imaging modalities.

RESULTS

EPIMix was well tolerated by all included patients (n = 15) aged 5-16 (mean 11, SD 3) years old. Thirteen cases on EPIMix and twelve cases on CT were classified as normal by all readers (R1-3), while two cases on EPIMix and three cases on CT were classified as abnormal by one reader (R1), (R1-3, p = 1.00). There was no evidence of a difference in diagnostic confidence, image quality, or the presence of motion artifacts between EPIMix and CT (R1-3, p ≥ 0.10). Side-by-side evaluation (R2 + R4 + R5) reviewed all scans as lacking significant pathological findings on EPIMix and CT images.

CONCLUSIONS

Full brain MRI-based EPIMix sequence was well tolerated without general anesthesia with a diagnostic performance comparable to CT in elective pediatric patients.

TRIAL REGISTRATION

This study was approved by the Swedish Ethical Review Authority (ethical approval number/ID Ethical approval 2017/2424-31/1). This study was a clinical trial study, with study protocol published at ClinicalTrials.gov with Trial registration number NCT03847051, date of registration 18/02/2019.

Rapid T 2 ∗ -weighted MRI using multishot EPI with retrospective motion and phase correction in the emergency department

PURPOSE

Brain MRI is increasingly used in the emergency department (ED), whereT 2 * $$ {\mathrm{T}}_2^{\ast } $$ -weighted MRI is an essential tool for detecting hemorrhage and stroke. The goal of this study was to develop a rapidT 2 * $$ {\mathrm{T}}_2^{\ast } $$ -weighted MRI technique capable of correcting motion-induced artifacts, thereby simultaneously improving scan time and motion robustness for ED applications.

METHODS

A 2D gradient-echo (GRE)-based multishot EPI (msEPI) technique was implemented using a navigator echo for estimating motion-induced errors. Bulk rigid head motion and phase errors were retrospectively corrected using an iterative conjugate gradient approach in the reconstruction pipeline. Three volunteers and select patients were imaged at 3 T and/or 1.5 T with an approximately 1-min full-brain protocol using the proposed msEPI technique and compared to an approximately 3-min standard-of-care GRE protocol to examine its performance.

RESULTS

Data from volunteers demonstrated that in-plane motion artifacts could be effectively corrected with the proposed msEPI technique, and through-plane motion artifacts could be mitigated. Patient images were qualitatively reviewed by one radiologist without a formal statistical analysis. These results suggested the proposed technique could correct motion-induced artifacts in the clinical setting. In addition, the conspicuity of susceptibility-related lesions using the proposed msEPI technique was comparable, or improved, compared to GRE.

CONCLUSION

A 1-min full-brainT 2 * $$ {\mathrm{T}}_2^{\ast } $$ -weighted MRI technique was developed using msEPI with a navigator echo to correct motion-induced errors. Preliminary clinical results suggest faster scans and improved motion robustness and lesion conspicuity make msEPI a competitive alternative to traditionalT 2 * $$ {\mathrm{T}}_2^{\ast } $$ -weighted MRI techniques for brain studies in the ED.

Non-ionizing Imaging for the Emergency Department Assessment of Pediatric Minor Head Trauma

Minor blunt head trauma (MHT) represents a common reason for presentation to the pediatric emergency department (ED). Despite the low incidence of clinically important traumatic brain injuries (ciTBIs) following MHT, many children undergo computed tomography (CT), exposing them to the risk associated with ionizing radiation. The clinical predictions rules developed by the Pediatric Emergency Care Applied Research Network (PECARN) for MHT are validated accurate tools to support decision-making about neuroimaging for these children to safely reduce CT scans. However, a few non-ionizing imaging modalities have the potential to contribute to further decrease CT use. This narrative review provides an overview of the evidence on the available non-ionizing imaging modalities that could be used in the management of children with MHT, including point of care ultrasound (POCUS) of the skull, near-infrared spectroscopy (NIRS) technology and rapid magnetic resonance imaging (MRI). Skull ultrasound has proven an accurate bedside tool to identify the presence and characteristics of skull fractures. Portable handheld NIRS devices seem to be accurate screening tools to identify intracranial hematomas also in pediatric MHT, in selected scenarios. Both imaging modalities may have a role as adjuncts to the PECARN rule to help refine clinicians' decision making for children at high or intermediate PECARN risk of ciTBI. Lastly, rapid MRI is emerging as a feasible and accurate alternative to CT scan both in the ED setting and when repeat imaging is needed. Advantages and downsides of each modality are discussed in detail in the review.

Rapid-sequence MRI for evaluation of pediatric traumatic brain injury: a systematic review

OBJECTIVE

Rapid-sequence MRI (RSMRI) of the brain is a limited-sequence MRI protocol that eliminates ionizing radiation exposure and reduces imaging time. This systematic review sought to examine studies of clinical RSMRI use for pediatric traumatic brain injury (TBI) and to evaluate various RSMRI protocols used, including their reported accuracy as well as clinical and systems-based limitations to implementation.

METHODS

PubMed, EMBASE, and Web of Science databases were searched, and clinical articles reporting the use of a limited brain MRI protocol in the setting of pediatric head trauma were identified.

RESULTS

Of the 1639 articles initially identified and reviewed, 13 studies were included. An additional article that was in press at the time was provided by its authors. The average RSMRI study completion time was variable, spanning from 1 minute to 16 minutes. RSMRI with "blood-sensitive" sequences was more sensitive for detection of hemorrhage compared with head CT (HCT), but less sensitive for detection of skull fractures. Compared with standard MRI, RSMRI had decreased sensitivity for all evidence of trauma.

CONCLUSIONS

Protocols and uses of RSMRI for pediatric TBI were variable among the included studies. While traumatic pathology missed by RSMRI, such as small hemorrhages and linear, nondisplaced skull fractures, was frequently described as clinically insignificant, in some cases these findings may be prognostically and/or forensically significant. Institutions should integrate RSMRI into pediatric TBI management judiciously, relying on clinical context and institutional capabilities.

Risk of Traumatic Brain Injuries in Infants Younger than 3 Months With Minor Blunt Head Trauma

STUDY OBJECTIVE

Infants with head trauma often have subtle findings suggestive of traumatic brain injury. Prediction rules for traumatic brain injury among children with minor head trauma have not been specifically evaluated in infants younger than 3 months old. We aimed to determine the risk of clinically important traumatic brain injuries, traumatic brain injuries on computed tomography (CT) images, and skull fractures in infants younger than 3 months of age who did and did not meet the age-specific Pediatric Emergency Care Applied Research Network (PECARN) low-risk criteria for children with minor blunt head trauma.

METHODS

We conducted a secondary analysis of infants <3 months old in the public use data set from PECARN's prospective observational study of children with minor blunt head trauma. Main outcomes included (1) clinically important traumatic brain injury, (2) traumatic brain injury on CT, and (3) skull fracture on CT.

RESULTS

Of 10,904 patients <2 years old, 1,081 (9.9%) with complete data were <3 months old; most (750/1081, 69.6%) sustained falls, and 633/1081 (58.6%) underwent CT scans. Of the 514/1081 (47.5%) infants who met the PECARN low-risk criteria, 1/514 (0.2%, 95% confidence interval [CI] 0.005% to 1.1%), 10/197 (5.1%, 2.5% to 9.1%), and 9/197 (4.6%, 2.1% to 8.5%) had clinically important traumatic brain injuries, traumatic brain injuries on CT, and skull fractures, respectively. Of 567 infants who did not meet the low-risk PECARN criteria, 24/567 (4.2%, 95% CI 2.7% to 6.2%), 94/436 (21.3%, 95% CI 17.6% to 25.5%), and 122/436 (28.0%, 95% CI 23.8% to 32.5%) had clinically important traumatic brain injuries, traumatic brain injuries, and skull fractures, respectively.

CONCLUSION

The PECARN traumatic brain injury low-risk criteria accurately identified infants <3 months old at low risk of clinically important traumatic brain injuries. However, infants at low risk for clinically important traumatic brain injuries remained at risk for traumatic brain injuries on CT, suggesting the need for a cautious approach in these infants.

Trends and variation in repeat neuroimaging for children with traumatic intracranial hemorrhage

OBJECTIVES

We aimed to determine trends and institutional variation in repeat neuroimaging in children with traumatic intracranial hemorrhage and to identify factors associated with neuroimaging modality (subsequent magnetic resonance imaging [MRI] vs computed tomography [CT]).

METHODS

We conducted a retrospective cross-sectional study of 35 hospitals in the Pediatric Health Information System database. We included children <18 years of age hospitalized from 2010-2019 with intracranial hemorrhage and who underwent a brain CT. We calculated repeat neuroimaging rates by modality and used regression analyses to examine temporal trends. We used hierarchical logistic regression to identify factors associated with subsequent MRI versus repeat CT, controlling for hospital.

RESULTS

We identified 12,714 children with intracranial hemorrhage, of which 5072 with repeat neuroimaging were studied. Of the 5072 children with repeat neuroimaging, repeat CT was performed in 67.6% (n = 3429) and subsequent MRI in 32.4% (n = 1643). Overall repeat neuroimaging with either a CT or MRI remained similar from 2010-2019 (P = 0.431); however, repeat CT scans significantly decreased (P = 0.001); whereas, MRIs significantly increased (P < 0.001). Repeat neuroimaging by hospital ranged from 20%-80%. After controlling for institution, subsequent MRI was more likely to be used in younger children and children who did not receive hyperosmotic agents, neurosurgical interventions, or intensive care unit admission (all P-values <0.001).

CONCLUSIONS

We found that repeat neuroimaging rates for children with intracranial hemorrhage vary substantially by institution. We also found that although MRI was increasingly used to re-image these children, overall repeat neuroimaging rates (CT or MRI) have not decreased over the past decade. Future work to implement optimal utilization of neuroimaging in these children is needed.