Despite advanced imaging techniques refinements in recent years, themorphologic MR remains the standard for neuro-oncologydiagnostic and follow-up. There is a list of image criteria to help differentiate the nature of the commonest brain tumors in adults: metastasis (mets) and glioblastoma (GB). Table 1,Fig. 1,Fig. 2 Even so, the differential is stilla frequent dilemma in everyday practice at the neuro-oncology units, with great implications in patient’s initial diagnosis and subsequently adequate treatment which can differ substantially. In our experience, when both mets and GB exhibit similar...

Catalan Instituteof Oncology performs its activity in Duran & Reynals Hospital working together with theBellvitge UniversityHospital, as a reference center specialized in cancer treatment. It has a network of collaboration with 7 county hospitals within the south area of Catalonia, covering a population of over 1.200.000 patients. Image acquisition: The MRs were performed in our center at Philipps 1.5T & 3T MR devices. All the MRs included at least sagittal T1, axial T2, axial FLAIR, axial DWI, and coronal and axial T1 post- gadolinium injection....

7 out of 120 GB and 28 out of 56 mets showed the "T2-parenchymal cleft sign". The sensitivity was 0.5 while the specificityreached 0.94. The differences between diagnostic groups were significant (p<0. 001). Table 2 **During the analysis, we observed differences between 1.5T and 3T studies, being the sign much more consistent in the latter. Fig. 5 In a preliminary test, we extracted a small subgroup of 21mets and correlative GB, all studied in 3T MR device. In the 3T subgroup, 16 out of 21...

The“T2-parenchymal cleft sign”is highly specific, so when present it is a great aid to discriminate mets from GB. However, its absence is not discriminatory. In a preliminary subgroup test, we observed a significant improvement in sensitivity and specificity of the sign in the 3T exams. In the advanced imaging and artificial intelligence era; we provide a simple but novel imaging sign that helps in discriminate mets from GB. Fig. 6

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