ABPA, Pulmonary Cystic Fibrosis
Conditions
Brief summary
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.
Detailed description
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.
Interventions
None listed
Sponsors
University Hospital, Bordeaux
Institut National de la Santé Et de la Recherche Médicale, France
Hôpital Haut Lévêque
Study design
Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
6 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Cystic fibrosis proven by sweat chloride and genetic tests * Age superior or equal to 6 year-old * Diagnosis of ABPA available on the basis of the criteria by Cystic Fibrosis Foundation Consensus Conference * No contraindication to perform MRI Non-Inclusion Criteria: . Age inferior to 6-year-old * Cystic fibrosis not proven * ABPA status not documented * MRI contraindications: Pregancy, Magnetically activated implanted devices (cardiac pacemakers, insulin pumps, neurostimulators, cochlear implants...), metal inside the eye or the brain (aneurysm clip, ocular foreign body not compatible with MRI), cardiac valvular prothesis not compatible with MRI, subject with claustrophobia.
Exclusion criteria
None
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diagnostic accuracy of lung MRI for ABPA in CF owing to increased T1 and decreased T2 signal intensity of mucus | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | 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 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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 | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | 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 |
| Diagnostic follow-up of patients ABPA status 1 year | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | Re-evaluation of diagnostic criteria for ABPA with up to 1-year follow-up in patients with undetermined ABPA status at initial evaluation |
| Diagnostic accuracy of MRI to detect ABPA in CF using various ABPA classifications | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | To assess the accuracy of lung MRI to detect ABPA in a CF patient cohort if various ABPA classification are used |
| Reproducibility of qualitative and quantitative imaging evaluations | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | To assess the intra-observer and inter-observer reproducibility of 2 readers to diagnose ABPA in CF using lung MRI |
| Diagnostic accuracy of quantitative measurement of central mucoid impaction signal on T1-weighted sequence and T2-weighted sequence | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | 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 |
| Diagnostic accuracy of morphological imaging using CT with reduction of doses down to chest radiograph level | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | Measurement of sensitivity, specificity, positive predictive value, negative predictive value of CT to diagnose ABPA in CF, owing to the presence of structural alterations |
| Reproducibility between MRI and CT with reduction of doses down to chest radiograph level to assess structural alterations | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | 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 |
| Severity of small airway and perfusion alterations using functional MR sequences | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | Measurement of correlations between functional MRI and disease severity |
| Follow-up of disease severity under treatement | From date of inclusion until the date of final treatment, assessed up to 12 months | Measurement of variation of MR outcomes under CF treatments |
| Diagnostic accuracy of morphological imaging using MRI with ultrashort echotimes | From date of inclusion until the date of final ABPA status diagnosis, assessed up to 12 months | 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 |
Countries
France
Outcome results
None listed