Correlation of T1- to T2-weighted signal intensity ratio with T1- and T2-relaxation time and IDH mutation status in glioma

• Published in: Scientific reports Vol. 12; no. 1; p. 18801
• Main Authors: Sanada, Takahiro, Yamamoto, Shota, Sakai, Mio, Umehara, Toru, Sato, Hirotaka, Saito, Masato, Mitsui, Nobuyuki, Hiroshima, Satoru, Anei, Ryogo, Kanemura, Yonehiro, Tanino, Mishie, Nakanishi, Katsuyuki, Kishima, Haruhiko, Kinoshita, Manabu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.11.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 631/67/1922; 631/67/2321; 692/4028/67/1922; 692/4028/67/2321; Archives & records; Biomedical research; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - genetics; Brain Neoplasms - pathology; Brain tumors; Cancer; Cohort analysis; Embedding; Gene amplification; Genomes; Glioma; Glioma - diagnostic imaging; Glioma - genetics; Glioma - pathology; Hospitals; Humanities and Social Sciences; Humans; Isocitrate Dehydrogenase - genetics; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; multidisciplinary; Mutation; Neurosurgery; Pathology; Patients; Retrospective Studies; Scanners; Science; Science (multidisciplinary); Software; Stochasticity; Tumors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-23527-9

The current study aimed to test whether the ratio of T1-weighted to T2-weighted signal intensity (T1W/T2W ratio: rT1/T2) derived from conventional MRI could act as a surrogate relaxation time predictive of IDH mutation status in histologically lower-grade gliomas. Strong exponential correlations were found between rT1/T2 and each of T1- and T2-relaxation times in eight subjects (rT1/T2 = 1.63exp −0.0005T1-relax  + 0.30 and rT1/T2 = 1.27exp −0.0081T2-relax  + 0.48; R 2  = 0.64 and 0.59, respectively). In a test cohort of 25 patients, mean rT1/T2 (mrT1/T2) was significantly higher in IDHwt tumors than in IDHmt tumors ( p  < 0.05) and the optimal cut-off of mrT1/T2 for discriminating IDHmt was 0.666–0.677, (AUC = 0.75, p  < 0.05), which was validated in an external domestic cohort of 29 patients (AUC = 0.75, p  = 0.02). However, this result was not validated in an external international cohort derived from TCIA/TCGA (AUC = 0.63, p  = 0.08). The t-Distributed Stochastic Neighbor Embedding analysis revealed a greater diversity in image characteristics within the TCIA/TCGA cohort than in the two domestic cohorts. The failure of external validation in the TCIA/TCGA cohort could be attributed to its wider variety of original imaging characteristics.