Keywords:
Dilatation, Calcifications / Calculi, Arteriosclerosis, Diagnostic procedure, Contrast agent-intravenous, Digital radiography, CT-Angiography, Thorax, Cardiovascular system, Arteries / Aorta
Authors:
A. Mereu1, E. Scapin1, M. Porcu2, L. Saba1; 1Monserrato/IT, 2Cagliari/IT
Methods and Materials
We retrospectively analyzed 18 subjects (15 males,
3 females; age range between 55 and 86,
mean 74 years) who underwent both a two views CXR (posteroanterior and lateral views) and a CTA within 365 days from each other.
An exemplifying case,
which compares CXR and CTA views,
is shown in Fig.1.
The sample size is relatively small because CTAs including thoracic aorta permit to examine lung parenchyma and other chest structures as well,
so it is uncommon to require a CXR if a CTA is planned or already performed; therefore,
in this sample,
clinical request for both imaging techniques were mainly concerning urgency care,
such as suspected pneumonia and pneumothorax in CXRs and aortic dissection or severe chest pain in CTAs.
In both imaging techniques the presence of TACC or lack thereof and its enlargement or lack thereof were analyzed by a radiologist separately, thus creating four possible outcomes for both pathologies: TACC could be evident or not in CXR as well as in CTA,
aorta enlargement could be evident or not in CXR as well as in CTA.
Statistical analysis was performed analyzing previous four outcomes for both pathologies separately,
considering CTA as the gold standard.
Since all the subjects underwent both imaging techniques,
McNemar’s test was performed to assess if there was a significant statistically difference between them: the level of significance was set to p-values lesser than 0.05.
On the same data,
accuracy,
Kappa statistic,
negative and positive likelihood ratios,
negative and positive predictive values,
sensitivity,
specificity,
Youden’s index and their confidence intervals at the 95% level were evaluated.
Calculation and statistical analysis were performed using R programming language version 3.4.1 (June 30,
2017),
on a Linux OS.