New CT technology with ultra-low radiation dose is superior to lung X-rays

(Vienna, October 30, 2023) Despite its diagnostic superiority, computed tomography (CT) has not yet established itself as a primary method of chest examination in emergency medicine for the most frequently asked questions. Lung X-rays are still usually the method of choice, especially because of their low cost and very low X-ray dose. As part of the current study at the Medical University of Vienna (University Clinic of Radiology and Nuclear Medicine in collaboration with the University Clinic of Emergency Medicine), a new CT technology has been confirmed as a real alternative: Ultra-low-dose computed tomography (ULDCT) offers several advantages (e.g. Nonoverlapped) for standard CT scans, but requires a much lower radiation dose than about two standard lung X-rays. The research work was recently published in the renowned journal ‘eClinical Medicine’ under The Lancet Discovery Science series.

Wide availability, short diagnostic times, low costs, and, above all, relatively low radiation exposure, make lung X-rays the radiological imaging modality of choice for a wide range of indications in emergency medicine. In terms of sensitivity and specificity, standard chest CT would be significantly superior to X-ray, but the significantly higher mean radiation dose than standard CT precluded its use as a primary imaging modality of the chest in patient populations. With a low prevalence of the disease. However, recent advances in CT technology have significantly reduced radiation exposure for native chest ULDCTs. The radiation dose of ULDCT now only corresponds to two standard lung X-ray examinations (in two planes), so this disadvantage has been almost eliminated.

This development has now allowed ULDCT of the chest to be considered as a diagnostic alternative to conventional X-rays in non-trauma patients in the emergency room. “At the same time, the question has been raised as to whether the original ULDCTs of chest with low doses of The first was Christian Wassipol (Department of Radiology and Nuclear Medicine, Medical University of Vienna) as the starting point for the currently published study, which was carried out in collaboration with the University Clinic for Emergency Medicine at the Medical University of Vienna.

To answer this question, the research group developed a prospective study design with a low risk of statistical bias that was possible in the clinical routine of the emergency department and radiology department. This made it possible to obtain accurate information about the detection rate of results and diagnoses of both methods and, above all, about their individual clinical significance in relation to the hospital stay in question. “In this prospective, crossover cohort study with a low incidence of disease in the emergency room, we found that the clinical value of chest ULDCT is significantly superior to lung X-ray at a radiation dose of only two standard lung X-ray examinations.” Study leader Helmut Ringel (University Hospital for Radiology and Nuclear Medicine at the Medical University of Vienna; Institute for Diagnostic and Interventional Radiology at the Donaustadt Clinic) summarizes the results. “The improved diagnostic detection rate of ULDCT supports clinical referrs in making an accurate diagnosis. Application of this screening method in routine acute medicine seems reasonable and desirable,” adds Karin Janata Schwaczek (University Clinic of Emergency Medicine at the Medical University of Vienna).

The observed benefits in terms of detection rate, including a doubling of the percentage of primary diagnoses detected directly, would support the use of ULDCT as a primary imaging modality in emergency medicine in the future if appropriate resources are available, the researchers said. Because these resources are scarce at many institutions, further studies are necessary to determine the economic rationale and optimal range of indications for broader replacement of CXR with ULDCT.

Publication: Clinical Medicine (The Lancet Discovery Science)
Ultra-low-dose CT versus chest X-ray in non-trauma emergency department patients–a prospective, randomized cohort trial.
Christian Wasipol, Karen Janata Schwaczek, Hans Domanowicz, Dietmar Tamandl, Helmut Brosch, Martina Scharitzer, Stefan Palahniuk, Rüdiger E. Scherntaner, Thomas Mange, Ulrika Asenbaum, Paul Apfalter, Filippo Cacioppo, Nicola Schuetz, Michael Weber, Peter Homolka, and Wolfgang. Birkfellner, Christian Herold, Helmut Ringel
doi: https://doi.org/10.1016/j.eclinm.2023.102267