New applications of magnetic resonance imaging for thoracic oncology

Our plain-English summary of New applications of magnetic resonance imaging for thoracic oncology, by Y. Ohno (Seminars in Respiratory and Critical Care Medicine, 2014).

The study

• Author: Y. Ohno
• Journal: Seminars in Respiratory and Critical Care Medicine
• Published: 2014;35(1):27-40
• Type of article: Review
• Cited by: 26 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Since the clinical introduction of magnetic resonance imaging (MRI), the chest has been one of its most challenging applications, and since the 1980s many physicists and radiologists have been trying to evaluate images for various lung diseases as well as mediastinal and pleural diseases. However, thoracic MRI could not yield image quality sufficient for a convincing diagnosis within an acceptable examination time, so MRI did not find acceptance as a substitute for computed tomography (CT) and other modalities. Until the 2000, thoracic MRI was generally used only for select, minor clinical indications. Within the past decade, however, technical advances in sequencing, scanners and coils, adaptation of parallel imaging techniques, utilization of contrast media, and development of postprocessing tools have been developed. In addition, pulmonary functional MRI has been extensively researched, and MR is being assessed as a new research and diagnostic tool for pulmonary diseases. State-of-the art thoracic MRI now has the potential as a substitute for traditional imaging techniques and/or to play a complimentary role in patient management. In this review, we focus on these advances in MRI for thoracic oncologic imaging, especially for pulmonary nodule assessment, lung cancer staging, mediastinal tumor diagnosis and malignant mesothelioma evaluation, prediction of postoperative lung function, and prediction or evaluation of therapeutic effectiveness. We also discuss the potential and limitations of these advances for routine clinical practice in comparison with other modalities such as CT, positron emission tomography (PET), PET/CT, or nuclear medicine studies.

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In plain English

This article was a narrative review, by a single author at Kobe University in Japan, of published research on newer magnetic resonance imaging (MRI) techniques for chest cancers. It covered lung nodules, lung cancer staging, tumors of the mediastinum (the central chest), malignant mesothelioma, predicting lung function after surgery, and judging response to treatment. Throughout, it compared MRI with CT, PET and PET/CT. It reported no new study; its results were drawn from published studies. On pleural disease, it described one study of 18 malignant and 16 benign cases. In that study, high signal on proton-density-weighted and T2-weighted MRI images helped distinguish malignant from benign disease, with 100% sensitivity and 87% specificity. In another study, of 95 patients with malignant pleural mesothelioma, MRI was more accurate than CT for invasion of the diaphragm (82% versus 55%). A third reviewed study found higher diffusion values in the epithelioid than in the sarcomatoid mesothelioma subtype. Asbestos appeared only as background. The author concluded that published results indicate MRI can complement or substitute for CT, PET and nuclear medicine tests, while also stating that more clinical trials are needed.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Narrative review of published studies on MRI techniques for chest cancer imaging; no new study was reported
• Who was studied: No study population of its own. The review covered published imaging studies of patients with pulmonary nodules, lung cancer (mainly non-small cell lung cancer), mediastinal tumors and malignant mesothelioma.
• Exposure: No exposure was studied. Asbestos was mentioned only as background, citing other work, as the main association of malignant pleural mesothelioma.
• Main results:
  • In a reviewed study (Falaschi et al) of patients with pleural disease (18 malignant, 16 benign), CT and MR were equally effective for assessing morphological features.
  • In the same reviewed study, high signal intensity on proton-density-weighted and T2-weighted MRI helped distinguish malignant from benign pleural disease, with sensitivity 100% and specificity 87%.
  • In a reviewed study (Patz et al) of resectability of malignant pleural mesothelioma in the diaphragm and chest wall, sensitivity was 94 and 93% for CT and 100% and 100% for MRI.
  • In a reviewed study (Heelan et al) of 95 patients with malignant pleural mesothelioma, accuracy for invasion of the diaphragm was 55% for CT and 82% for MRI. Accuracy for invasion of the endothoracic fascia or solitary resectable foci of chest wall invasion was 46% for CT and 69% for MRI.
  • In a reviewed study (Gill et al, 2010), the apparent diffusion coefficient on diffusion-weighted MRI was statistically significantly higher in the epithelioid subtype of malignant pleural mesothelioma than in the sarcomatoid subtype.
  • For lung cancer spread to distant sites (M-stage) in non-small cell lung cancer, a reviewed study found that the accuracy of whole-body MRI combined with diffusion-weighted imaging (87.8%) was not significantly different from that of FDG-PET/CT.
  • For solitary pulmonary nodules, a reviewed study found that the specificity of diffusion-weighted imaging (97.0%) was significantly higher than that of FDG-PET/CT (79.0%).
• The authors' conclusion: The author concluded that published results indicate MRI can play a complementary role to, or substitute for, CT, FDG-PET or PET/CT and nuclear medicine examinations, and expected future studies to validate this.
• Limitations the authors state:
  • The author stated that further protocol development, more clinical trials and wider use of advanced analysis tools are needed to determine the real significance of thoracic MRI.
  • The author noted that MRI is not usually the first-line imaging test for suspected pleural malignancy; CT is usually preferred initially.
  • For predicting lung function after surgery, the author stated that large prospective cohort studies are still needed.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer.

Medical terms in this study, explained in our Lexicon: Lung Cancer, Staging, Mesothelioma.

Related studies

• Applications of Magnetic Resonance Imaging of the Thorax in Pleural Diseases: A State-of-the-Art Review — F.M. Pessôa, A.S. de Melo, et al. (2016)
• Asbestos-related pleural disease: value of dedicated magnetic resonance imaging techniques — M.A. Weber, M. Bock, et al. (2004)
• Asbestos-related pericardial thickening detected by magnetic resonance imaging — N.A. Jarad, S.R. Underwood, et al. (1993)
• Early Contrast Enhancement: A novel magnetic resonance imaging biomarker of pleural malignancy — S. Tsim, C.A. Humphreys, et al. (2018)
• The use of magnetic resonance imaging in malignant mesothelioma — J. Entwisle (2004)
• Magnetic resonance imaging of the thorax in the evaluation of asbestosis — S.I. Bekkelund, U. Aasebø, et al. (1998)

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