MDCT and MRI in Bronchiectasis in Older Children and Young Adults - A Non-Inferiority Trial.

Objectives: To compare and evaluate the usefulness of magnetic resonance imaging (MRI) with computed tomography (CT) in bronchiectasis; to compare MRI and CT scores with pulmonary function tests (PFT) and to evaluate the role of Diffusion-weighted imaging (DWI) in bronchiectasis.

Methods: In this prospective study, 25 patients between 7-21 y of age with a clinical/radiological diagnosis of bronchiectasis underwent MDCT and MRI chest. MRI and CT scoring was performed using modified Bhalla-Helbich's score by two independent radiologists for all parameters. A final consensus score was recorded. The overall image quality of different MRI sequences to identify pathologies was also assessed. Appropriate statistical tests were used for inter-observer agreements, and correlation amongst CT and MRI; as well as CT, MRI and PFT.

Results: Strong agreement (ICC 0.80-0.95) between CT and MRI was seen for extent and severity of bronchiectasis, number of bullae, sacculation/abscess, emphysema, collapse/ consolidation, mucus plugging, and mosaic perfusion. Overall CT and MRI scores had perfect concordance (ICC 0.978). Statistically significant (p-value <0.01) intra-observer and inter-observer agreement for all CT and MRI score parameters were seen. A strong negative correlation was seen between total CT and MRI severity scores and forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), forced expiratory flow (FEF) 25-75%. DWI MR, with an apparent diffusion coefficient (ADC) cut-off of 1.62 × 10 mm/s had a sensitivity of 70% and specificity of 75% in detecting true mucus plugs.

Conclusions: MRI with DWI can be considered as a radiation-free alternative in the diagnostic algorithm for assessment of lung changes in bronchiectasis, especially in follow-up.