Verena Obmann MD, Presenter: Nothing to Disclose

Zsolt Szucs-Farkas MD, PhD, Abstract Co-Author: Nothing to Disclose

Andreas Christe, Abstract Co-Author: Nothing to Disclose

Sebastian Ott, Abstract Co-Author: Nothing to Disclose

Enno Stranzinger MD, Abstract Co-Author: Nothing to Disclose

Imaging plays a crucial role in the evaluation and management of patients with cystic fibrosis. More accurate assessment of the disease state enables a targeted therapy of this chronic lung disease. The primary goal is the improvement of the quality of life and prolongation of the life expectancy. The aim of the study is to evaluate the diagnostic benefit of Dual-Energy subtraction (DE-) radiography in comparison with conventional radiographs (CR) in adult patients with cystic fibrosis (CF).

49 DE-radiographs of 24 adult patients (16 males, 8 females) with cystic fibrosis (median age 32 years, range 18-71 years) were included in the study. Lung function tests (FEV1%/predicted and FVC%/predicted) were performed within 10 days of the radiography. Two radiologists (13 and 3 years of experience) evaluated all CR (PA view only) in a blinded and randomized order. In a second reading all DE-radiographs were evaluated together with the CR one month later. The modified Chrispin Norman score (CNS), including the extend of over inflation, bronchial line, ring, mottled and large shadows, was used to assess changes in the lung parenchyma. A five point score was used to determine the diagnostic confidence of all pulmonary findings. The Wilcoxon statistics and the Spearman’s rank-test were used to compare the CNS of conventional and DE-radiographs and to correlate CNS with the lung function tests.

CNS of both the CR images and DE-radiographs correlated significantly with FEV1% (R= -0.729 and -0.659; P<0.001) and FVC% (R= -0.709 and -0.628; P<0.001), differences between correlation coefficients of CR and DE were not significant (P= 0.113 and 0.174, respectively). A higher confidence was achieved with DE-radiographs compared to radiographs alone (median, 3.6 vs 3.4; P= 0.01).

DE-radiographs are well suited for the evaluation of patients with CF. A good correlation with the clinical parameters was observed. The confidence of the readers to interpret pulmonary changes in CF is significantly higher with DE radiographs. However, considering the higher radiation dose of DE radiographs, the diagnostic benefit for the patients with cystic fibrosis compared to CR was statistically not significant.

DE-subtraction radiography provides lung images without the superimposition of the bones. Pulmonary changes in cystic fibrosis can be detected with higher diagnostic confidence than with CR.

Obmann, V, Szucs-Farkas, Z, Christe, A, Ott, S, Stranzinger, E, Dual-energy Subtraction Radiography in Cystic Fibrosis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045455.html