Cystic Fibrosis in Adults: Short-Term and Long-Term Reproducibility of the Brody Score for Lung Morphology in Low-Dose MDCT Scans

Abstract

Purpose: The semi-quantitative Brody score measures the severity of cystic fibrosis (CF)-related lung disease. We investigated the short-term (28 – 60 days) and long-term (2 – 7 years) intra- and inter-observer reproducibility of the Brody score in low-dose multidetector row computed tomography examinations performed in inspiration (LDCTs) of adult CF patients.

Materials and Methods: Composite Brody scores and respective underlying bronchiectasis, mucus plugging, peribronchial thickening, parenchymal opacity, and hyperinflation subscores were evaluated twice (time interval, 1 – 84 months) by each of 3 independent radiologists (1 – 20 years of professional diagnostic radiology experience) in LDCTs (4 – 64 rows, 120 KVp, 10 – 15 mAs/slice, CTDIw approx. 1.0 mGy, effective dose approx. 0.5 mSv) of 15 adult patients with CF-related lung disease (8 female, 7 male, age, 18 – 50 years, mean, 33 years).

Results: The average reproducibility of the Brody score was within +/–7 % (range, 2 – 30 %) between radiologists, and +/–6 % (3 – 12 %) within radiologists (short-term, 28 – 60 days, 4 %, 0 – 12 %, long-term, 2 – 7 years, 12 %, 1 – 36 %). For the different subscores, the reproducibility was within +/–25 % (15 – 41 %) between radiologists and +/–23 % (12 – 46 %) within radiologists.

Conclusion: The Brody score shows high average inter-observer reproducibility in LDCTs of adult CF patients. The Brody score also demonstrates high average intra-observer reproducibility if subsequent assessments are made within 28 – 61 days. With time intervals of 2 – 7 years between subsequent evaluations, however, intra-observer reproducibility decreases. Respective subscores each demonstrate lower intra- and inter-observer reproducibility than does the composite Brody score.

Citation Format:

• Weber K, Paolini M, Schmitz M et al. Cystic Fibrosis in Adults: Short-Term and Long-Term Reproducibility of the Brody Score for Lung Morphology in Low-Dose MDCT Scans. Fortschr Röntgenstr 2014; 186: 54 – 60

Zusammenfassung

Ziel: Auswertungen des semiquantitativen Brody- Score quantifizieren das Ausmaß CF-bedingter Lungenschädigung. Die Studie untersuchte die Kurz- (KZI, 28 – 60 Tage) und Langzeit- (LZI, 2 – 7 Jahre), Intra- und Inter-Betrachter-Reproduzierbarkeit des Brody-Scores und seiner Subscores (Bronchiektasen, peribronchiale Zeichnungsvermehrung, Mucusplugging, Gewebekonsolidierung und Überblähung) anhand von Niedrig-Dosis-Multidetektor-CT-Aufnahmen in Inspiration (LDCT) von 15 erwachsenen CF-Patienten.

Material und Methoden: Die Niedrig-Dosis-Multidetektor-CT-Aufnahmen (Schichtdicke 1,5 und 3 mm, 120 kV, mAS/Schicht 10 – 15, effektive Dosis 0,5 mSv, CDTi 1,0 Gy/Patient) von 15 Patienten (8 weiblich, 7 männlich, Altersspanne 18 – 50 Jahre, durchschnittliches Alter 33 J.) mit pulmonaler Manifestation bei CF wurden bzgl. des Brody-Score und seiner Subscores (Bronchiektasen, peribronchiale Zeichnungsvermehrung, Schleimverlegung, Gewebekonsolidierung, Überblähung) von 3 unabhängigen Radiologen (1 – 20 Jahre Berufserfahrung) jeweils zweimal ausgewertet (Zeitintervall zwischen den Auswertungen, 1 – 84 Monate).

Ergebnisse: Die durchschnittliche Inter-Betrachter-Reproduzierbarkeit des Brody-Score betrug +/– 7 % (2 – 30 %). Die Intra-Betrachter-Reproduzierbarkeit lag bei +/–6 % (3 – 12 %) (KZI, 4 %, 0 – 12 %, LZI, 12 %, 1 – 36 %). Für die Subscores betrug die Inter-Betrachter-Reproduzierbarkeit durchschnittlich +/–25 % (15 – 41 %), die Intra-Betrachter-Reproduzierbarkeit +/–23 % (12 – 46 %).

Schlussfolgerung: Der Brody-Score zeigt eine hohe Inter-Betrachter-Reproduzierbarkeit bei LDCTs erwachsener CF-Patienten sowie eine gute Intra-Betrachter-Reproduzierbarkeit im KZI erfolgen, welche jedoch im LZI sinkt. Im Vergleich zum Gesamtscore zeigen die Subscores durchschnittlich eine geringere Inter- und Intra-Betrachter-Reproduzierbarkeit.

Key words

CT - thorax - cystic fibrosis - Brody score - reproducibility - image interpretation

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