• non-cystic fibrosis bronchiectasis
• chest
• magnetic resonance imaging

Purpose:
Magnetic resonance imaging (MRI) has gained importance in the evaluation of the chest, especially in pediatric patients affected by cystic fibrosis, while little is known about its application in adult patients with non-cystic fibrosis bronchiectasis (NCFB).
The aim of this thesis was to explore the role of MRI in adult patients with NCFB, compared to computed tomography (CT); additionally, the feasibility and the potential role of diffusion-weighted imaging (DWI) were investigated too for the detection of pulmonary inflammatory findings.

Materials and methods:
In this single-center retrospective evaluation, 12 patients with NCFB underwent chest MRI in our Institution. Unenhanced morphologic imaging with T1 and T2-weighted (w) sequences and chest CT were scored by 2 radiologists (A and B) using the modified Helbich (Bhalla) score. A visual assessment and a semi-quantitative score were applied to DW images obtained with multiple b-values (b=0,400 and 800 s/mm2).

Results:
A good to moderate inter-reader consistency for the overall MRI and CT scores (ICCMRIA-B = 0.72; ICCCTA-B = 0.83) was found. Both readers obtained positive Spearman’s correlation coefficients when comparing the global MRI and CT scores (p < 0.05).
The reader with greater experience showed moderate intra-reader agreement (ICCAMRI-CT = 0.73). Based on DWIb0 and T2-w images, three patterns of hyperintense findings were identified: triangular- lamellar, pseudonodular-spot and linear. As b values increased, detectable findings reduced, particularly the linear ones, and those persistent showed heterogeneous signal intensities than spinal cord. In the middle lobe and lingula, there were more pseudonodular-spot elements on the highest b- value than in the reference images.

Conclusions:
MRI could play a role in the evaluation of morphologic findings in adult patients with NCFB even through a relative short and feasible imaging protocol.
DWI might aid in the detection of pulmonary alterations, highlighting the more relevant ones. Further research is needed to elucidate the nature and degree of inflammation of persistent DWI elements.