3T MRI in evaluation of asbestos-related thoracic diseases - preliminary results

Our plain-English summary of 3T MRI in evaluation of asbestos-related thoracic diseases - preliminary results, by J. Podobnik, I. Kocijancic, V. Kovac, et al (Radiology and Oncology, 2010).

The study

• Authors: J. Podobnik, I. Kocijancic, V. Kovac, I. Sersa
• Journal: Radiology and Oncology
• Published: 2010;44(2):92-6
• Cited by: 20 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: 3T high-field magnetic resonance imaging (MRI) scanners have recently become available for the clinical use and are being increasingly applied in the field of whole-body imaging and chest imaging as well. The aim of this study was to evaluate the diagnostic potential of 3 T MRI as a complementary imaging modality to CT in detecting the pathological changes of asbestos-related thoracic diseases.

Patients And Methods: Fifteen patients with the asbestos-related thoracic disease were scheduled for 3T MRI. Five had a benign form of the disease and 10 had malignant pleural mesothelioma (MPM). From the patients with a benign form of the disease their last CT examination in digital form was acquired and patients with MPM were scheduled for CT examination with contrast media. The protocol of MR imaging consists of T2-weighted cardiac-gated breath-hold turbo spin echo (TSE) sequences in coronal, sagittal and axial plane and T1-weighted cardiac-gated breath-hold TSE black blood in axial plane. In T2-weighted sequences in axial plane, fat saturation was also used. CT examinations were obtained with the administration of the contrast medium from lung apices to the lower end of the liver. Images of 5 mm (mediastinum window) and 3 mm (lung window) in axial plan were reconstructed. MRI signal intensity of lesions and adjacent muscles on Syngo MultiModality Work Place were measured.

Results: Compared to muscles pleural plaques appeared hypo-intense to iso-intense on T1 weighted images (in 100%) and also hypo-intense on T2 fs-weighted images (in 100%). MPM appeared inhomogeneous hypo-intense to iso-intense on T1-weighted and hyperintense on T2 fs-weighted images in all patients (100%).

Conclusions: These preliminary results pointed out that MRI was equal or even better compared with CT examination for detecting possible malignant potential of pleural changes in the asbestos-related pleural disease, using signal intensity measurements of T2 fs-weighted images. The 3T MRI enabled the accurate determination of chest pathology and it could be used for imaging of patients with the asbestos-related thoracic disease. MRI is particularly valuable because a patient is not exposed to the harmful radiation which is important if imaging methods are used repeatedly, like in screening programs or in monitoring of treatment results. This finding turned us to propose 3T MRI imaging technique as a non-ionizing imaging method for the follow-up of patients with the isolated pleural form of the asbestos-related disease.

In plain English

This small preliminary study from Slovenia compared 3 tesla (3T) MRI scans with CT scans in 15 patients with asbestos-related chest disease. Five patients, all men with occupational asbestos exposure, had a benign form of the disease. Ten had malignant pleural mesothelioma; three men in this group had occupational exposure, and the others had a history of environmental exposure. The authors measured how bright each lesion appeared on MRI compared with nearby muscle. On fat-suppressed T2-weighted images, pleural plaques were darker than muscle in all benign patients, and mesothelioma was brighter than muscle in all mesothelioma patients. On T1-weighted images, plaques were darker than or similar to muscle in all benign patients. Mesothelioma was darker in eight patients (80%), similar in one (10%) and brighter in one (10%). The authors reported that MRI showed tumour extent more accurately than CT and showed diffuse pleural thickening more distinctly. The authors concluded that MRI was equal to or better than CT for detecting possible malignant potential of pleural changes. They said their plaque findings need confirming in more patients.

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: Preliminary imaging study (small patient series) comparing 3T MRI with CT, using MRI signal-intensity measurements of lesions relative to muscle
• Who was studied: 15 patients with asbestos-related thoracic disease, imaged in Slovenia (dates not given). Five had a benign form of the disease: all male, median age 66, range 53 to 76. Ten had malignant pleural mesothelioma: 6 males and 4 females, median age 62, range 50 to 75.
• Exposure: Asbestos exposure, occupational or environmental. No fiber types, jobs or doses given. All 5 benign-disease patients were occupationally exposed. In the mesothelioma group, only 3 males were occupationally exposed; the others had a history of environmental exposure.
• Main results:
  • On fat-suppressed T2-weighted images, the MRI signal from benign plaques was hypo-intense (darker) compared with muscle in all benign patients (100%). The signal was hyper-intense (brighter) in all patients with malignant pleural mesothelioma (100%).
  • On T1-weighted images, the signal from benign pleural plaques was hypo-intense to iso-intense compared with muscle in all benign patients (100%).
  • On T1-weighted images in the 10 mesothelioma patients, the signal was hypo-intense in eight (80%), iso-intense in one (10%) and hyper-intense in one (10%).
  • The authors reported that 3T MRI showed the extent of the tumour, and the accompanying pleural solid and fluid components, with greater accuracy than CT in mesothelioma patients.
  • Diffuse pleural thickening was more distinctive on MRI than on CT images.
  • In the 5 benign-disease patients, 3T MRI was comparable with CT, showing almost the same extent and nature (calcified and non-calcified) of pleural plaques.
  • In the images shown for one patient, calcification on the side of the plaques was more clearly outlined on CT than on MRI.
• The authors' conclusion: The authors concluded that, in these preliminary results, MRI was equal to or even better than CT for detecting possible malignant potential of pleural changes in asbestos-related pleural disease, using signal intensity measurements on fat-suppressed T2-weighted images.
• Limitations the authors state:
  • The finding that 3T MRI was comparable to CT for pleural plaques came from only 5 patients. The authors said statistically significant conclusions need confirmation in a larger number of patients.

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Apices, Mediastinum, Pleural Plaques, Asbestos-Related Pleural Disease, Pathology.

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