Proton MRI appearance of cystic fibrosis: Comparison to CT

Abstract

Cystic fibrosis (CF) is the most frequent inherited disorder leading to premature death in the Caucasian population. As life expectancy is limited by pulmonary complications, repeated imaging [chest X-ray, multislice high-resolution computed tomography (MS-HRCT)] is required in the follow-up. Magnetic resonance imaging (MRI) of the lung parenchyma is a promising new diagnostic tool. Its value for imaging lung changes caused by CF compared with CT is demonstrated. MRI performs well when compared with CT, which serves as the gold standard. Its lack in spatial resolution is obvious, but advantages in contrast and functional assessment compensate for this limitation. Thus, MRI is a reasonable alternative for imaging the CF lung and should be introduced as a radiation-free modality for follow-up studies in CF patients. For further evaluation of the impact of MRI, systematic studies comparing MRI and conventional imaging modalities are necessary. Furthermore, the value of the additional functional MRI (fMRI) information has to be studied, and a scoring system for the morphological and functional aspect of MRI has to be established.

An Official American Thoracic Society Clinical Practice Guideline: Classification, Evaluation, and Management of Childhood Interstitial Lung Disease in Infancy

“…The observations described here derive from two observational studies that found that CT scanning is more likely than CXR to accurately identify DLD in children (17,35), numerous case series that reported a strong correlation between histologic findings and the thin-section CT scan appearance in children with surfactant protein C mutation (42), neuroendocrine cell hyperplasia of infancy (NEHI) ( Figure 5) (20) and other DLDs (17,19,35), and two studies that demonstrated that CT scanning is superior to MRI in resolution and in identifying ground glass opacity, normal peripheral bronchi, and air trapping in patients with cystic fibrosis (43,44). Although cystic fibrosis is not a chILD disorder, resolution is an important determinant of image quality, and the findings of air trapping and ground glass opacity are key observations in chILD.…”

Comparison Between Magnetic Resonance Imaging and Computed Tomography of the Lung in Patients With Cystic Fibrosis With Regard to Clinical, Laboratory, and Pulmonary Functional Parameters

“…Computed tomography scores have been described to can be even more sensitive than pulmonary functional parameters in the detection of early CF lung disease and in determining the progression of lung manifestation. 10,29,37,38 Oikonomou et al 10 reported that simplification of the CT scoring systems provided even better findings than the original more extent scores. The more simplified structure of the Eichinger scoring system might be one main reason that the Eichinger score showed in general higher clinical correlations and stronger agreement between CT and MRI demonstrated in the Bland-Altman plot (Fig.…”

“…For analysis of the specific CT and MR imaging parameters, the following descriptions were used according to published definitions: -Bronchiectasis: 12,22,28,29 was defined as bronchial dilatation with respect to the accompanying pulmonary artery, lack of tapering of bronchi, and identification of bronchi within 1 cm of the pleural surface; in the modified Helbich score, the severity of bronchiectasis was estimated by comparing the bronchial luminal diameter with the size of the adjacent artery; -Peribronchial wall thickening 12,22 was separately assessed in the modified Helbich score in comparison with the adjacent artery; bronchiectasis and bronchial wall thickening were recorded as one single parameter in the Eichinger score; -Mucus plugging 12,21,22,28 was defined as fluid content within dilated bronchi greater than 3 mm without signal enhancement after contrast medium administration; peripheral mucus plugging can demonstrate a grapelike or "tree-in-bud" appearance. If mucus plugging was observed in the periphery, this segment or lobe was also scored for the parameter bronchiectasis; -Sacculation/abscess 12,22,29 was regarded as a circular structure with a diameter greater than 1.5 cm, which was air-filled or showed an air-fluid level and had a thick wall; -Collapse/consolidation 12,22,28,29 was defined as a homogeneous increase in pulmonary parenchymal density (CT) or signal intensity (MRI) with a size greater than 2 cm, which obscured the margins of vessels and airway walls; it can be caused by alveolar filling with inflammatory fluid and/or by atelectasis; -Bulla 12,28 was regarded as a sharply demarcated airspace with a diameter greater than 1 cm and a thin wall (<1 mm thickness) in the modified Helbich score (Table 2).…”

“…If mucus plugging was observed in the periphery, this segment or lobe was also scored for the parameter bronchiectasis; -Sacculation/abscess 12,22,29 was regarded as a circular structure with a diameter greater than 1.5 cm, which was air-filled or showed an air-fluid level and had a thick wall; -Collapse/consolidation 12,22,28,29 was defined as a homogeneous increase in pulmonary parenchymal density (CT) or signal intensity (MRI) with a size greater than 2 cm, which obscured the margins of vessels and airway walls; it can be caused by alveolar filling with inflammatory fluid and/or by atelectasis; -Bulla 12,28 was regarded as a sharply demarcated airspace with a diameter greater than 1 cm and a thin wall (<1 mm thickness) in the modified Helbich score (Table 2). In the Eichinger score, this parameter was not considered; -Emphysema 12,28 was defined as an area of decreased density (CT) or signal intensity (MRI) compared with the surrounding lung parenchyma combined with a reduction of vessels.…”

Imaging of Cystic Fibrosis Lung Disease and Clinical Interpretation

“…Depending on patient size and ability to breath-hold, it is useful to prepare three separate protocols (• ▶ Fig. 1 Table 2) [11,28,29]. Each should start with balanced steady-state free precession (bSSFP) sequences.…”