Fig 6. Comparison of the nADC value and CNR on T2-weighted images of 26 metastatic brain tumors of different histologic types. Most well differentiated adenocarcinomas (Well diff. AC) are distributed at high nADC and low CNR. Of the 3 small-cell carcinomas (Small cell ca.), 2 exhibit nADC values below 1.0. The large-cell neuroendocrine carcinoma (LCNC) manifests low nADC value and high CNR. Poorly differentiated adenocarcinoma (Poorly diff. AC), papillotubular carcinoma (Papillotubular ca.), sarcoma, and malignant melanoma (Melanoma) also exhibit low nADC values. Large cell ca. indicates large cell carcinoma; SCC, squamous cell carcinoma; Mucoepidermoid ca.: mucoepidermoid carcinoma; Mod. diff. AC, moderately differentiated adenocarcinoma.