Table 2.

Intertechnique reproducibility between 3D mammography and MRI with different slice thicknesses as estimated by Spearman correlation coefficients and P values between fibroglandular tissue volumes, total breast volumes, fibroglandular tissue percentages, and breast densities

	FGT volume (r (95% CI))	Total breast volume (r (95% CI))	Mammographic breast density or FGT-% (r (95% CI))
MRI 4-mm slice vs:
MLO (N = 55)	0.682* (0.509–0.802)	0.936* (0.893–0.962)	0.864* (0.777–0.918)
CC (N = 49)	0.777* (0.635–0.868)	0.900* (0.829–0.951)	0.819* (0.699–0.894)
AVG (N = 38)	0.807* (0.657–0.895)	0.967* (0.937–0.982)	0.873* (0.768–0.932)
MRI 2-mm slice vs:
MLO (N = 55)	0.659* (0.478–0.786)	0.928* (0.880–0.957)	0.884* (0.809–0.930)
CC (N = 49)	0.753* (0.599–0.853)	0.861* (0.766–0.919)	0.863* (0.769–0.920)
AVG (N = 38)	0.761* (0.584–0.869)	0.933* (0.874–0.964)	0.904* (0.822–0.949)
MRI 0.7-mm slice vs:
MLO (N = 55)	0.674* (0.498–0.796)	0.939* (0.898–0.964)	0.868* (0.784–0.921)
CC (N = 49)	0.811* (0.687–0.889)	0.894* (0.819–0.939)	0.856* (0.758–0.916)
AVG (N = 38)	0.793* (0.635–0.887)	0.964* (0.932–0.981)	0.871* (0.765–0.931)

MLO, mediolateral oblique view; CC, craniocaudal view; AVG, averaged measurements; FGT, fibroglandular tissue; FGT-%, fibroglandular tissue percentage

*P < 0.001