Pediatric MR lung imaging with 3D ultrashort‐TE in free breathing: Are we past the conventional T2 sequence?

Abstract

Objectives: Magnetic resonance imaging (MRI) of the lungs is challenging for several reasons, mainly due to the respiratory motion, low proton density, and rapid T2* decay. Recent MR sequences with ultrashort TE (UTE) coupled with respiratory compensation promise to overcome these obstacles. So far, there are very few studies on the relevance of these sequences in children. The aim of the study was to compare the diagnostic value of a respiratory-self-gated three-dimensional UTE sequence versus a conventional respiratory-triggered T2-weighted turbo spin echo (T2-TSE) sequence in a pediatric collective.Study Design: Seventy-one patients between 0 and 18 years of age, who were scheduled for a thoracic MRI based on diverse clinical indications, were examined on a 3T MRI system. The UTE and T2-TSE sequences were evaluated by two readers regarding quality features and visualization of eight common pathology patterns. Results:The image quality of both sequences was equally high, with UTE depicting pleural and central bronchi more clearly. In pathologies, UTE was superior to T2-TSE for so-called "MR-negative pathologies", significant for air trapping, and in tendency for bullae and cysts. In all remaining pathologies, T2-TSE proved to be at least equivalent to UTE.Conclusions: At present, UTE cannot serve as a universal replacement for conventional T2-TSE for all pathologies. It yields, however, a substantial benefit in the context of hyperinflation, emphysema, cysts, or pathologies of the bronchial system.

High resolution simulation and measurement demonstrate oscillatory spatiotemporal B0 fluctuations across the human cardiac cycle

“…These artifact-induced field distortions could be mitigated by acquiring high-quality 3D structural images in the thoracic region by adopting motion-corrected or compensated acquisition techniques. 34 Small amplitude discontinuities in B 0 distribution were observed in the in vivo B 0 maps, particularly in slices adjacent to the edge of two slabs acquired from different concatenations (data not shown). Although all the subjects were asked to hold their breath at the same respiratory phase, their anatomical structures, such as diaphragm position, may vary across these three concatenation scans.…”

“…The consequential motion artifacts in the structural images induce deviations in the delineation of the tissue air boundaries for B 0 simulation possibly in the order of a few voxels. These artifact‐induced field distortions could be mitigated by acquiring high‐quality 3D structural images in the thoracic region by adopting motion‐corrected or compensated acquisition techniques 34 …”

Comparison of chest computed tomography and 3-T magnetic resonance imaging results in patients with common variable immunodeficiency

“…MRI is valuable as a radiation-free alternative for these patients. Recently, technical advances, such as UTE imaging, have been reported in the imaging of lung changes (28,29). Considering the newly developed MRI sequences and developments in MRI technology, it is predicted that lung MRI examinations will provide faster and more accurate information in the future (9,10).…”

Chest examinations in children with real-time magnetic resonance imaging: first clinical experience

“…The standard lung protocol consisted of two T2 turbo spin echo (TSE) sequences with respiratory triggering in axial and coronal planes and one T2-TSE sequence with fat saturation in the axial plane (Online Supplementary Material 3). In 30 of the 87 participants (35%), a self-gated PDw-UTE sequence was also conducted [16]. All examinations were performed on a 3-T scanner (Prisma Fit; Siemens, Erlangen, Germany).…”