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

BACKGROUND: MRI of the lung is recommended in a number of clinical indications. Having a non-radiation alternative is particularly attractive in children and young subjects, or pregnant women. METHODS: Provided there is sufficient expertise, magnetic resonance imaging (MRI) may be considered as the preferential modality in specific clinical conditions such as cystic fibrosis and acute pulmonary embolism, since additional functional information on respiratory mechanics and regional lung perfusion is provided. In other cases, such as tumours and pneumonia in children, lung MRI may be considered an alternative or adjunct to other modalities with at least similar diagnostic value. RESULTS: In interstitial lung disease, the clinical utility of MRI remains to be proven, but it could provide additional information that will be beneficial in research, or at some stage in clinical practice. Customised protocols for chest imaging combine fast breath-hold acquisitions from a "buffet" of sequences. Having introduced details of imaging protocols in previous articles, the aim of this manuscript is to discuss the advantages and limitations of lung MRI in current clinical practice. CONCLUSION: New developments and future perspectives such as motion-compensated imaging with self-navigated sequences or fast Fourier decomposition MRI for non-contrast enhanced ventilation- and perfusion-weighted imaging of the lung are discussed. Main Messages • MRI evolves as a third lung imaging modality, combining morphological and functional information. • It may be considered first choice in cystic fibrosis and pulmonary embolism of young and pregnant patients. • In other cases (tumours, pneumonia in children), it is an alternative or adjunct to X-ray and CT. • In interstitial lung disease, it serves for research, but the clinical value remains to be proven. • New users are advised to make themselves familiar with the particular advantages and limitations

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

Background Among 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. Methods This 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. Results Various 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. Conclusion This 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-indicate

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

Pediatric chest MRI is challenging. High-resolution scans of the lungs and airways are compromised by long imaging times, low lung proton density and motion. Low signal is a problem of normal lung. Lung abnormalities commonly cause increased signal intenstities. Among the most important factors for a successful MRI is patient cooperation, so the long acquisition times make patient preparation crucial. Children usually have problems with long breath-holds and with the concept of quiet breathing. Young children are even more challenging because of higher cardiac and respiratory rates giving motion blurring. For these reasons, CT has often been preferred over MRI for chest pediatric imaging. Despite its drawbacks, MRI also has advantages over CT, which justifies its further development and clinical use. The most important advantage is the absence of ionizing radiation, which allows frequent scanning for short- and long-term follow-up studie

Lung morphology assessment using MRI: a robust ultra-short TR/TE 2D steady state free precession sequence used in cystic fibrosis patients

To evaluate feasibility and diagnostic quality of ultra-short TR/TE two-dimensional (2D) steady state free precession (SSFP) MRI for cystic fibrosis (CF) patients. We performed lung MRI at 1.5 Tesla in 20 CF-patients (6-17 years, 12 males). Axial, coronal, and sagittal sections were acquired in inspiration and expiration with maximum breath-hold time 10 s. MR and CT images were scored using a modified Brody scoring system to assess bronchiectasis, mucous plugging, atelectasis/consolidations, and air trapping. All images were scored by two experienced observers. A complete MR investigation took maximally 15 min. Maximal breath-holds were only 10 s and well tolerated. MRI identified major bronchiectasis, mucous plugging and atelectasis. End-expiratory scans showed patches of parenchyma with reduced signal intensity that may corresponded to areas of trapped air on expiratory CT scans. This MRI protocol based on ultra-short TR/TE 2D SSFP is quick and well tolerated and provides highly relevant imaging features as seen on CT in CF patients. Most importantly, the SNR of the expiratory scans enables to visualize air trapping. The preliminary results of this study suggest MRI as a noteworthy additional imaging tool for routine monitoring of CF patients

P1552Different forms of evaluation of atherosclerotic load and its different predicted powers compared with framingham risk score

Abstract Introduction The screening of carotid and/or ileo-femoral subclinical atherosclerosis using vascular ultrasound could be a cost-effective tool in the reclassification of cardiovascular risk in primary cardiovascular prevention. But until today we don't have evidence indicating which atherosclerotic load indicator variable (such as plaque area, number of atherosclerotic plaques or affected territories) has the most predictive power for future cardiovascular events. Objectives a. Evaluate the prevalence of carotid and ileo-femoral subclinical atherosclerosis (SubAth). b. Evaluate the predictive power of each atherosclerotic load indicator variable for cardiovascular events (CVE). c. to compare those methods with Framingham Score for prediction of CVE. Material and methods We retrospectively evaluated patients from our registry called CARFARE (CARDIOMETABOLIC RISK FACTORS REGISTRY) conducted in the context of a cardiovascular primary prevention program (n=6108). In this analysis we included only those patients who completed a follow up ≥24 months from the first vascular evaluation. Exclusion criteria: &lt;40 or &gt;65 years old, BMI&gt;40 kg/m2, previous cardiovascular and/or cerebrovascular event, chronic stable angina. We used Framingham score for the cardiovascular risk assessment. We evaluated the following atherosclerotic load variables using high resolution vascular ultrasonography (Mannheim Consensus): carotid plaques area (AR-C), ileo-femoral plaques area (AR-IF), and total (carotid+ileo-femoral, AR-TOT), number of affected territories (N-TER). Primary composite endpoints (P-CVE): myocardial infarction, stroke, hospitalization due to angina or acute heart failure. For prediction power analysis we used ROC curves and logistic regressions (unadjusted and adjusted by age, sex, BMI, major cardiovascular risk factors and treatment). Results We included 1431 patients (55.0±9.78 y.o., 38% women, follow-up period of 789±23 days). The total P-CVE rate was 3.77% during this period (54 events). The overall prevalence of atherosclerosis in this population was 60.7%. The AUC of the ROC curves for P-CVE prediction was 0.648, for Framingham 0.706, for AR-C 0.726, for AR-IF 0.746, for AR-TOT and 0.79 for N-TER (graph). The AUC of AR-TOT and N-TER were significantly higher than the AUC of the Framingham score (p=0.017 and p=0.0004, respectively) for prediction of P-CVE. The dichotomization criteria according to ROC were: AR-C&gt;5.80 mm2, AR-IF&gt;23.0 mm2, AR-TOT&gt;43.9 mm2, and N-TER&gt;1. In the logistic regressions adjusted for prediction of P-CVE the OR were: Framingham 1.05 (95% CI: 1.02–1.07), AR-C 4.00 (95% CI: 1.89–8.47), AR-IF 4.01 (95% CI: 2.02–8.32), AR-TOT 4.35 (95% CI: 2.13- 8.91) and N-TER 6.95 (95% CI: 3.05–15.8). Comparison of ROC curves for CVE Conclusions The carotid/ileo-femoral SubAth scan was a more potent predictor of cardiovascular events than the Framingham score, particularly those variables that indicate extension of multiterritorial affection like AR-TOT or N-TER. </jats:sec