[High-resolution magnetic resonance tomography (HR-MRT) of the pleura and thoracic wall: normal findings and pathological changes]

Abstract

Aim: To determine the value of high-resolution MRI in pleural and chest wall diseases, the normal and pathologic costal pleura and adjacent chest wall between paravertebral and the axillary region were examined with contrast enhanced high-resolution T1-weighted MRI images using a surface coil.

Material and methods: Normal anatomy was evaluated in 5 healthy volunteers and a normal specimen of the thoracic wall, and correlation was made with corresponding HR-CT and histologic sections. CT-proved focal and diffuse changes of the pleura and the chest wall in 36 patients underwent HR-MRI, and visual comparison of MRI and CT was done retrospectively.

Results: Especially sagittal T1-weighted HR-MRI images allowed accurate delineation of the peripleural fat layer (PFL) and the innermost intercostal muscle (IIM), which served as landmarks of the intact inner chest wall. PFL and IIM were well delineated in 3/4 patients with tuberculous pleuritis, and in all 7 patients with non-specific pleuritis, as opposed to impairment of the PFL and/or the IIM, which was detected in 15/18 malignancies as a pattern of malignant chest wall involvement. In one case of tuberculous pleural empyema with edema of the inner chest wall HR-MRI produced false positive diagnosis of malignant disease.

Conclusion: HR-MRI images improved non-invasive evaluation of pleural and chest wall diseases, and allowed for differentiation of benign and malignant changes.