MRI of the lung (2/3). Why … when … how?

Abstract

BackgroundAmong the modalities for lung imaging, proton magnetic resonance imaging (MRI) has been the latest to be introduced into clinical practice. Its value to replace X-ray and computed tomography (CT) when radiation exposure or iodinated contrast material is contra-indicated is well acknowledged: i.e. for paediatric patients and pregnant women or for scientific use. One of the reasons why MRI of the lung is still rarely used, except in a few centres, is the lack of consistent protocols customised to clinical needs.MethodsThis article makes non-vendor-specific protocol suggestions for general use with state-of-the-art MRI scanners, based on the available literature and a consensus discussion within a panel of experts experienced in lung MRI.ResultsVarious sequences have been successfully tested within scientific or clinical environments. MRI of the lung with appropriate combinations of these sequences comprises morphological and functional imaging aspects in a single examination. It serves in difficult clinical problems encountered in daily routine, such as assessment of the mediastinum and chest wall, and even might challenge molecular imaging techniques in the near future.ConclusionThis article helps new users to implement appropriate protocols on their own MRI platforms.Main Messages• MRI of the lung can be readily performed on state-of-the-art 1.5-T MRI scanners.• Protocol suggestions based on the available literature facilitate its use for routine• MRI offers solutions for complicated thoracic masses with atelectasis and chest wall invasion.• MRI is an option for paediatrics and science when CT is contra-indicated

Targeting and in vivo imaging of non-small–cell lung cancer using nebulized multimodal contrast agents

“…As a matter of fact, tumor signal enhancement using gadolinium-based contrast agents is a common approach in clinical and preclinical MRI for improving the detection and the delineation of cancerous tissue (20,23,32). However, contrast enhancement of tumors located in the lung can be severely hampered by motion artifacts and unmatched magnetic susceptibility between air and tissues (6,7,(10)(11)(12). In addition, for this organ, airway delivery of diagnostic or therapeutic compounds might be an efficient (yet unexplored) route for targeting lung tumors.…”

“…MRI has been shown to be especially promising because of high soft tissue contrast, good spatial resolution, and absence of ionizing radiation (6,7). The latter, in particular, represents a strong advantage over nuclear medicine imaging techniques and computed tomography because it enables repeated acquisitions in patients and screening in old and young patients, without introducing a consistent risk of developing radiation-induced secondary pathologies (8).…”

“…Nevertheless, this consideration cannot yet be applied to the lung, which remains one of the most difficult organs to image with MRI because of its intrinsic properties (motion artifacts, low proton density, numerous susceptibility gradients) (6,7,(10)(11)(12).…”

Imaging of Cystic Fibrosis Lung Disease and Clinical Interpretation

“…Lung proton MRI sequences with dedicated protocols are now readily provided by all large vendors [27]. Depending on patient size and ability to breath-hold, it is useful to prepare three separate protocols (• ▶ Fig.…”

“…Mucus plugging within the large airways is sensitively depicted by T2-weighted sequences, for example a half-Fourier single shot fast spin echo acquisition. A four-dimensional dynamic contrast-enhanced perfusion study (spoiled GRE) at high temporal resolution (1.5 s per lung volume with 20 -30 consecutive acquisitions) with intravenous application of gadolinium-based contrast by a power injector is recommended [27]. The common side effects of i. v. contrast injection, dose as well as national prescription regulations need to be considered with respect to patient age.…”