CT diagnostics of pulmonary embolism: Does iodine delivery rate still affect image quality in iterative reconstruction?
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.
['Burdenski|Thomas|T|', 'Bressem|Keno K|KK|', 'Adams|Lisa C|LC|', 'Grauhan|Nils F|NF|', 'Niehues|Stefan M|SM|']
D003287:Contrast Media D006801:Humans D007455:Iodine D011651:Pulmonary Artery D011655:Pulmonary Embolism D014057:Tomography, X-Ray Computed
pulmonary embolism iodine concentration Computed tomography contrast media