Impact of iodine concentration and scan parameters on image quality, contrast enhancement and radiation dose in thoracic CT

European Radiology Experimental

Table 1 Details of the contrast medium specifics

Phantom size	Scan parameter tube voltage:	Constant CTDI					Dose modulation
Phantom size	Scan parameter tube voltage:	70 kVp	80 kVp	100 kVp	120 kVp	140 kVp	70 kVp	80 kVp	100 kV	120 kV	140 kV
Large	Rotation time (s)	1	1	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
	mAs (range 80–500)	500	395	405	250	170	499	499	464	372	282
	CTDIvol (mGy)	13.17	16.6	16.68	16.6	16.43	6.59	10.11	14.79	16.6	17.59
Medium	Rotation time (s)	1	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
	mAs (range 80–500)	380	475	240	150	105	499	499	322	244	178
	CTDIvol (mGy)	10	9.98	9.89	9.96	10.15	6.09	8.14	8.98	10	11.6
Small	Rotation time (s)	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
	mAs (range 80–500)	500	330	170	105	70	484	630	219	106	123
	CTDIvol (mGy)	6.59	6.93	7.00	6.97	6.77	4.67	5.18	5.73	7.05	8.75

CTDIvol Volume computed tomography dose index. Scan technique: constant CTDIvol and dose modulation (SmartmA) using conventional, iterative reconstruction. Additional parameters: scan mode, helical; detector collimation, 80 × 0.625; pitch, 0.5; scan field of view, 50 cm; display field of view, 36 cm; reconstructed slice thickness, 2.5 mm; reconstruction kernel, standard; iterative reconstruction, adaptive statistical iterative reconstruction, ASIR-V 50%; noise index14.5 (scans with dose modulation)