MRI; MR DIffusion; Non-Invasive Ventilation; PET/CT; High-Frequency Ventilation; Lung Nodule; Lung Cancer; F-18-FDG
Darçot Emeline, Delacoste Jean, Dunet Vincent, Dournes Gael, Rotzinger David, Bernasconi Maurizio, Vremaroiu Petrut, Simons Julien, Long Olivier, Rohner Chantal, Ledoux Jean-Baptiste, Stuber Matthias, Lovis Alban, Beigelman-Aubry Catherine (2020), Lung MRI assessment with high-frequency noninvasive ventilation at 3 T, in Magnetic Resonance Imaging
, 74, 64-73.
Delacoste Jean, Dunet Vincent, Dournes Gael, Lovis Alban, Rohner Chantal, Elandoy Christel, Simons Julien, Long Olivier, Piccini Davide, Stuber Matthias, Prior John O., Nicod Laurent, Beigelman-Aubry Catherine (2019), MR Volumetry of Lung Nodules: A Pilot Study, in Frontiers in Medicine
, 6, 1-6.
Although computed tomography (CT) is the modality of choice for chest imaging, the potential danger of radiation exposure remains a problematical health problem, despite current significant improvements on dose reduction. In this setting, the capabilities of Magnetic Resonance Imaging (MRI) are tempting. However, MRI of the chest has since ever suffered from its sensitivity to respiratory and cardiac motion, this along with an intrinsically low signal-to-noise ratio of the lungs and a limited spatial resolution. To control motion respiration, existing solutions such as repeated apnoeas and motion compensation techniques allowing free-breathing acquisition have intrinsic limitations. The suppression of respiratory artefacts should benefit to all MR sequences. Moreover, while free-breathing MR acquisitions are usually gated or triggered at end of normal expiration, a technique allowing an acquisition at end inspiration would be well suited for lung analysis. Indeed, at expiration or with free-breathing, there is a potential underdiagnosis of lesions such as nodules and interstitial lung disease in some locations. In this setting, the CHUV has developed a new system able to almost suppress respiratory motion in spontaneously breathing patients, while preserving efficient oxygen and carbon dioxide exchanges. This was firstly applied to radiotherapy and PET-CT. Preliminary tests performed with high-frequency non-invasive ventilation (HF-NIV) in MRI (HF-NIV-MR) enabled a prolonged apnoea duration with an acquisition performed at end inspiration with promising results. Whereas the system of ventilation has been further improved, the aim of the planned study is to evaluate its additional value in the field of lung nodule. The results of HFNIV-MR will be compared to those obtained by using repeated apnoea or free-breathing with motion compensation techniques, and with low dose CT in pathologic conditions, for an accurate evaluation of the benefits and the potential limits of the technique. A main hypothesis is that HF-NIV-MR will allow an improvement of the overall image quality (IQ) compared to conventional apnoea methods. In particular, an improvement in the detection of pulmonary nodules is expected with recent ultra-short echo time (UTE) sequences with an increased diagnostic confidence. In addition to morphologic evaluation, a quantitative assessment of pulmonary nodules will also be performed by comparing the volumetry between HF-NIV-MR and CT, taking into account its value for evaluating lung cancer probability. A preliminary evaluation will be performed on MR phantoms simulating solid nodules of various volumes. Moreover, an additional hypothesis is that virtual PET-MR could be performed due to the almost identical and reproducible lung volumes obtained by both techniques when using the device, even if they are acquired separately. Indeed, this should allow a fusion of similar or even better quality than the current dedicated hybrid PET/-MR systems, at a significant lower cost, and accessible to any hospital/centre having both PET/CT and MR modalities. The optimized value of FDG-uptake will be correlated to the results of MR diffusion sequences in indeterminate pulmonary nodules and to histological data when available, with potentially better lesion characterization. Evaluation of numerous categories of chest disorders, such as pulmonary nodules, interstitial lung disease or pulmonary infections could benefit of this technique. One of most promising application would be the management of pulmonary nodules in the setting of screening of broncho-pulmonary carcinoma.