In this diagnostic study, the aim is at evaluating the diagnostic accuracy of MRI (Magnetic Resonance Imaging) to detect allergic broncho-pulmonary aspergillosis in patients with cystic fibrosis.
Allergic broncho-pulmonary aspergillosis (ABPA) is not rare in the context of cystic fibrosis (CF), with a prevalence reported between 2% to 16%. This complication is a diagnostic challenge for clinicians, since it is related with poorer outcome and higher worsening of the disease. Therefore, the treatment relies on corticosteroid and antifungal therapy and thus, it is important to detect with good sensitivity because CF patients are usually treated with antibiotics. However, the treatment is often difficult to be initiated because of potential secondary side effects related to diabetes mellitus, growth impairment, bone mineralisation or immunodepression. Therefore, there is a need for specific diagnostic tool to discriminate ABPA amongst other polymicrobial infection. Lung MRI is a radiation-free imaging modality which offers the potential to combine several contrasts, in order to enable in vivo tissue characterization non-invasively. Investigators hypothesize that characterization of mucoid impaction using lung MR T1-weighted and T2-weighted contrasts may be a specific tool to diagnose ABPA in CF non invasively. Additional information on functional information related to ventilation and/or perfusion will be assessed using functional MR sequences, to assess the severity of small airway impairment. Moreover, the diagnostic value of structural alterations such as bronchiectasis, mucoid impaction and consolidation/atelectasis using either MRI with ultrashort echo times or CT using reduction of doses down to chest radiograph levels will be assessed.
Study Type
OBSERVATIONAL
Enrollment
240
University Hospital Bordeaux
Bordeaux, Aquitaine, France
Diagnostic accuracy of lung MRI for ABPA in CF owing to increased T1 and decreased T2 signal intensity of mucus
Measurement of sensitivity, specificity, positive predictive value, negative predictive value of lung MRI to diagnose ABPA in CF, owing to the presence of central mucoid impactions that appear both hyperintense on T1-weighted sequence and hypointense on T2-weighted sequence
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Diagnostic accuracy of quantitative measurement of central mucoid impaction signal on T1-weighted sequence and T2-weighted sequence
Measurement of sensitivity, specificity, positive predictive value, negative predictive value of lung MRI to diagnose ABPA in CF, owing to the quantitative measurement of signal from central mucoid impaction using T1-weighted and T2-weighted sequences
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Diagnostic accuracy of hyperattenuated central mucoid impaction on chest computed tomography (CT) to detect ABPA in CF, using reduction of doses down to chest radiograph level
Measurement of sensitivity, specificity, positive predictive value, negative predictive value of lung MRI to diagnose ABPA in CF, owing to the presence of central mucoid impactions that appear hyperattenuated on chest CT
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Diagnostic follow-up of patients ABPA status 1 year
Re-evaluation of diagnostic criteria for ABPA with up to 1-year follow-up in patients with undetermined ABPA status at initial evaluation
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Diagnostic accuracy of MRI to detect ABPA in CF using various ABPA classifications
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To assess the accuracy of lung MRI to detect ABPA in a CF patient cohort if various ABPA classification are used
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Reproducibility of qualitative and quantitative imaging evaluations
To assess the intra-observer and inter-observer reproducibility of 2 readers to diagnose ABPA in CF using lung MRI
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Diagnostic accuracy of morphological imaging using MRI with ultrashort echotimes
Measurement of sensitivity, specificity, positive predictive value, negative predictive value of lung MRI to diagnose ABPA in CF, owing to the presence of structural alterations
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Diagnostic accuracy of morphological imaging using CT with reduction of doses down to chest radiograph level
Measurement of sensitivity, specificity, positive predictive value, negative predictive value of CT to diagnose ABPA in CF, owing to the presence of structural alterations
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Reproducibility between MRI and CT with reduction of doses down to chest radiograph level to assess structural alterations
Measurement of agreement and concordance between MRI with ultrashort echo times and CT with reduction of doses down to chest radiograph level to assess the Bhalla score
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Severity of small airway and perfusion alterations using functional MR sequences
Measurement of correlations between functional MRI and disease severity
Time frame: From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months
Follow-up of disease severity under treatement
Measurement of variation of MR outcomes under CF treatments
Time frame: From date of inclusion until the date of final treatment, assessed up to 12 months