Hybrid Modality Fusion of Planar Scintigrams and CT Topograms to Localize Sentinel Lymph Nodes in Breast Lymphoscintigraphy: Technical Description and Phantom Studies

Table 1

Measured exposure and calculated CT topogram dose versus kV and mA. For topogram acquisitions, three conversion factors (Rontgen-to-mGy, backscatter factor, and skin dose-to-effective dose) are used to estimate the effective dose for several techniques of topogram acquisition.

KV	mA	Time [s]	Tube position	Measured exposure (in-air) [mR]	Skin dose [mGy]	Effective dose (NRPB-W4) [mSv]
130	20	3.1	Top (A/P)	32.29	0.40	0.040
			bottom (p/A)	25.91	0.32	0.032
110	20	3.1	top (A/p)	23.19	0.28	0.028
			Bottom (P/A)	18.36	0.23	0.023
80	20	3.1	Top (A/P)	12.72	0.16	0.016
			Bottom (P/A)	9.78	0.12	0.012