Role of respiratory-triggered diffusion-weighted MRI in the assessment of pleural disease

The British Journal of Radiology 2016 June 15 [Epub ahead of print] [Link]

Revelli M, Chiesa F, Del Prato A, Tagliafico A, Rosenberg I, Canessa PA, Pinelli V, Villa A.

Abstract

OBJECTIVES:
to evaluate the correlation between apparent diffusion coefficient (ADC) values and histopathological features in a cohort of patients with suspected malignant pleural disease.
METHODS:
we evaluated 56 consecutive patients undergoing a chest MRI examination for clinical suspicion of malignant pleural disease; all patients underwent thoracoscopic biopsy for histological assessment. All MRI exams were performed with a 1.5T scanner using a dedicated protocol, including a respiratory-triggered diffusion-weighted sequence with 3 b values (0, 100, 750). ADC values were calculated and a statistical analysis was performed.
RESULTS:
Average ADC value in non-neoplastic pleural disease (NNPD) resulted of 1.84 ± 0.37 × 10-3 mm2/s, while we obtained an average value of 0.96 ± 0.19 × 10-3 mm2/s in epitheliod, of 0.76 ± 0.33 × 10-3 mm2/s in biphasic and of 0.67 ± 0.2 × 10-3 mm2/s in sarcomatoid pleural mesotheliomas. Histology revealed the presence of malignant pleural mesothelioma (MPM) in 44 patients, chronic pleuritis in 8 patients and atypical mesothelial hyperplasia in 4 patients. Statistical analysis showed a significant difference between NNPD and MPM (p < 0.001) and between epithelioid and sarcomatoid MPM subtypes (p = 0.0004), while biphasic MPMs showed a wide range of overlapping with the other groups. CONCLUSIONS: we observed a statistically significant difference between NNPD, epitheliod and sarcomatoid subtypes of MPM regarding ADC values. ADVANCES IN KNOWLEDGE: our study confirmed previous data regarding distribution of ADC values in pleural disease using a respiratory-triggered diffusion-weighted technique that allowed us to minimize motion artifacts and to reduct acquisition time.