Magnetic resonance imaging and molecular features associated with tumor-infiltrating lymphocytes in breast cancer

Breast Cancer Research

Table 1 Definition and interpretation of 17 computational imaging features extracted from dynamic contrast-enhanced magnetic resonance imaging scans

Type	No.	Definition	Interpretation
Morphology (M)	5	M1: Volume	Tumor shape, size, and boundary smoothness (i.e., descriptors according to BI-RADS classification)
		M2: Sphericity
		M3: Surface-to-volume ratio
		M4: Mean of margin sharpness
		M5: SD of margin sharpness
Texture of kinetic maps (TEX)	4	TEX1: Correlation of SER	Spatial tumor heterogeneity of the SER map
		TEX2: Cluster shade of SER
		TEX3: Energy of SER
		TEX4: Entropy of SER
Functional tumor volume (FTV)	2	FTV1: Absolute volume of the active tumor with SER > 1.0	Subvolume of tumor with fast contrast uptake and washout
Functional tumor volume (FTV)	2	FTV2: Absolute volume of the active tumor with SER > 1.5	Subvolume of tumor with fast contrast uptake and washout
Ipsilateral background parenchymal enhancement (BPE)	4	BPE1: Absolute volume of BPE with PE > 0.2	Enhanced subvolume of ipsilateral breast parenchyma at the early postcontrast phase, in accordance with the BI-RADS classification
		BPE2: Absolute volume of BPE with PE > 0.6
		BPE3: Relative volume of BPE with PE > 0.2
		BPE4: Relative volume of BPE with PE > 0.6
Tumor surrounding background parenchymal enhancement (TS-BPE)	2	TS-BPE1: Mean value of PE in tumor surrounding parenchyma (2 cm)	Enhancement of parenchyma surrounding the tumor within 2-cm distance
	2	TS-BPE2: Mean value of SER in tumor surrounding parenchyma (2 cm)

BI-RADS Breast Imaging Reporting and Data System, PE percent enhancement; \( PE=\frac{I_{early\ postcontrast}-{I}_{precontrast}}{I_{precontrast}} \), SER signal enhancement ratio; \( SER=\frac{I_{early\ postcontrast}-{I}_{precontrast}}{I_{late\ postcontrast}-{I}_{precontrast}} \)

ISSN: 1465-542X