Neonatal Pulmonary Magnetic Resonance Imaging of Bronchopulmonary Dysplasia Predicts Short-Term Clinical Outcomes

Abstract

Quiet-breathing neonatal pulmonary MRI can independently assess structural abnormalities of BPD, describe disease severity, and predict short-term outcomes more accurately than any individual standard clinical measure. Importantly, this nonionizing technique can be implemented to phenotype disease, and has potential to serially assess efficacy of individualized therapies.

Elevated lung volumes in neonates with bronchopulmonary dysplasia measured via MRI

“…Anonymized UTE MRI scans were independently graded by two board‐certified radiologists (22 and 6 years of experience) with a hyperinflation score (based upon the Ochiai scoring system for chest CT, later adopted for MRI) ranging from 0 to 2, where 0 = no hyperinflation, 1 = focal hyperinflation, and 2 = global hyperinflation. The mean of the two radiologists’ scores was used for analysis.…”

“…New techniques in ultrashort echo time (UTE) MRI provide improved visualization of proton density in parenchymal tissue, where there is typically rapid relaxation of the MR signal, and are more robust to motion artifacts than conventional MR sequences, allowing for increased image quality in the setting of cardiac and pulmonary motion . These developments in MRI allow for sensitive tomographic detection of fibrosis and hyperinflation without exposing young patients to ionizing radiation (Figure ).…”

Quantitative Assessment of Regional Dynamic Airway Collapse in Neonates via Retrospectively Respiratory‐Gated 1H Ultrashort Echo Time MRI

“…Additionally, scan times from gated Cartesian acquisitions are typically extended due to the insertion of a k 0 navigator module into each repetition and the multiple acquisitions necessary to fully encode the 3D dataset . In the context of imaging patients with comorbid lung and airway abnormalities, 3D UTE MRI with respiratory gating is an advantageous choice; the 3D FOV of UTE is large enough to simultaneously acquire lung and airway data from the same scan, such that there is the potential to evaluate multiple aspects of a patient's respiratory system from a single scan …”

“…36 In the context of imaging patients with comorbid lung and airway abnormalities, 3D UTE MRI with respiratory gating is an advantageous choice; the 3D FOV of UTE is large enough to simultaneously acquire lung and airway data from the same scan, such that there is the potential to evaluate multiple aspects of a patient's respiratory system from a single scan. 19 Radial zero echo-time (ZTE) MRI has previously been used in lung imaging 37 and has the advantage of being virtually silent. However, ZTE acquisitions inherently miss the center of k-space, 38 with this data gap typically addressed via acquisition oversampling or algebraic reconstruction.…”

“…13,14 As a nonionizing modality, magnetic resonance imaging (MRI) is an ideal diagnostic technique to address this clinical gap, particularly for longitudinal monitoring of disease and treatment efficacy in pediatrics, and also allows for population studies that include patients for whom there is no clinical indication for invasive airway evaluation. Recent developments in pulmonary MRI have yielded 3D high-resolution images of lung parenchyma using ultrashort echo-time (UTE) sequences, with good signal-to-noise contrast in soft and lung tissue (signal to noise ratio (SNR) 20 and 10 in neonates, respectively) and submillimeter resolution comparable to that of CT. [15][16][17][18][19] The radial k-space acquisition of UTE sequences can yield retrospective motion-tracking, [20][21][22] which has been used in nonsedated infants both for discarding of data acquired during bulkmotion and also for respiratory-gating of lung images for measuring tidal volumes and diaphragmatic function. [21][22][23] However, this retrospective respiratory-gating technique has yet to be applied to airway dynamics throughout the respiratory cycle.…”