CT diagnostics of pulmonary embolism: Does iodine delivery rate still affect image quality in iterative reconstruction?

Issue title: 40th Conference of the German Society for Clinical Microcirculation and Hemorheology, 5-6 November 2021, Senftenberg, Germany

Guest editors: J.-H. Küpper, A. Krüger-Genge and F. Jung

Article type: Research Article

Authors: Burdenski, Thomas^a | Bressem, Keno K.^{a; b} | Adams, Lisa C.^{a; b} | Grauhan, Nils F.^a | Niehues, Stefan M.^{a; *}

Affiliations: [a] Institute for Radiology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany | [b] Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Berlin, Germany

Correspondence: [*] Corresponding author: Stefan M. Niehues, Charité-Universitätsmedizin Berlin, Hindenburgdamm 30, 12203 Berlin, Germany. Tel.: +49 30 450527792; E-mail: Stefan.niehues@charite.de.

Abstract: BACKGROUND:Computed tomographic (CT) imaging in suspected pulmonary artery embolism represents the standard procedure. Studies without iterative reconstruction proved beneficial using increased iodine delivery rate (IDR). This study compares image quality in pulmonary arteries on iteratively reconstructed CT images of patients with suspected pulmonary embolism using different IDR. MATERIAL AND METHODS:1065 patients were included in the study. Patients in group A (n = 493) received an iodine concentration of 40 g/100 ml (IDR 1.6 g/s) and patients in group B (n = 572) an iodine concentration of 35 g/100 ml (IDR 1.4 g/s) at a flow rate of 4 ml/s. A 80-detector spiral CT scanner with iterative reconstruction was used. We measured mean density values in truncus pulmonalis, both pulmonary arteries and segmental pulmonary arteries. Subjectively, the contrast of apical and basal pulmonary arteries was determined on a 4-point Likert scale. RESULTS:Radiodensity was significantly higher in all measured pulmonary arteries using the increased IDR (p < 0.001). TP: 483.0 HU vs. 393.4 HU; APD: 452.1 HU vs. 372.1 HU; APS: 448.2 HU vs. 374.4 HU; ASP: 443.9 vs. 374.4 HU. Subjectively assessed contrast enhancement in apical (p = 0.077) and basal (p = 0.429) lung sections showed no significant differences. CONCLUSION:Higher IDR improves objective image quality in all patients with significantly higher radiodensities by iterative reconstruction. Subjective contrast of apical and basal lung sections did not differ. The number of non-sufficient scans decreased with high IDR.

Keywords: Computed tomography, pulmonary embolism, contrast media, iodine concentration

DOI: 10.3233/CH-219115

Journal: Clinical Hemorheology and Microcirculation, vol. 79, no. 1, pp. 81-89, 2021