Steady-state free precession projection MRI as a potential alternative to the conventional chest X-ray in pediatric patients with suspected pneumonia

Abstract

Magnetic resonance imaging of the lung tissue is thought to be hardly possible due to physical limitations especially the low proton density, susceptibility, and motion artifacts. The objective of our study was to evaluate and refine a very fast MR technique at a low field strength which overcomes the limitations in MR lung imaging. Thirty-five investigations were performed in 30 pediatric patients with suspected pneumonia. The MR investigations were performed in coronal slice orientation without cardiac or respiratory triggering in a low-field MR system. An optimized true fast imaging with steady precession sequence was applied. The MR images and the corresponding conventional chest radiographs were evaluated. The examination time per slice was 1.6 s. No motion artifacts could be observed. The signal-to-noise ratio for pulmonary parenchyma ranged from 4.9 to 7.1. All pathological findings of the chest X-ray images were correctly identified by the MRI (κ=0.82-0.85). Effusions as well as small pneumonic infiltrates were more precisely detected by the MRI investigation (κ=0.82) as compared with X-ray. Low-field projection MRI is a promising alternative to pediatric chest X-ray. Due to its short examination time, it overcomes the physical limits of usual MRI methods and provides comparable diagnostic information.

Rapid lung MRI in children with pulmonary infections: Time to change our diagnostic algorithms

“…27 MRI with fast imaging sequences has been found comparable to the chest radiography in evaluating underlying pulmonary consolidation, bronchiectasis, necrosis /abscess, and pleural effusion often associated with pneumonia in children. 28,29 We have previously described part of the preliminary findings of children with leukemia and febrile neutropenia. 30 Many pulse sequences have been assessed at 1.5T for the evaluation of pulmonary nodules and consolidation, and have found to be effective.…”

“…30 Many pulse sequences have been assessed at 1.5T for the evaluation of pulmonary nodules and consolidation, and have found to be effective. [28][29][30] The major advantage of higher field strengths (3T MRI) is almost linear increase of the signal-to-noise ratio. This can lead to an increase in the spatial resolution, which helps to improve lesion detection potentially.…”

MRI of the lung (3/3)—current applications and future perspectives

“…Comparable to CT, MRI is able to visualise air bronchograms as low signal areas following the course of the bronchi within the consolidation [17, 18]. With progression of the disease, complete destruction of lung segments or lobes can occur with similar appearances on MRI and CT.…”

“…The potential of MRI to replace chest radiography, particularly in very young children, was already investigated several years ago [18, 44–46]. Much of this work was conducted on low-field MRI (mainly 0.2-T scanners) using steady-state free precession sequences [47].…”

Magnetic resonance imaging in children: common problems and possible solutions for lung and airways imaging

“…Since then, we introduced an MRI protocol mainly composed of this sequence, as biennial MRI scans (alternating with CT) to monitor progression of CF lung disease. In children with suspicious pneumonia, steady-state free precession was compared to chest radiograph [ 33 ], showing really good correlation between MRI and chest radiograph for all pathological findings [ 33 ]. More recently, steady-state free precession scans have been proposed as the best option to assess lung fibrosis [ 31 ].…”