{"doi":"10.3174/ajnr.a8094","title":"Quantification of T2-FLAIR Mismatch in Nonenhancing Diffuse Gliomas Using Digital Subtraction","abstract":"<h3>BACKGROUND AND PURPOSE:</h3> The T2-FLAIR mismatch sign on MR imaging is a highly specific imaging biomarker of isocitrate dehydrogenase (<i>IDH</i>)-mutant astrocytomas, which lack 1p/19q codeletion. However, most studies using the T2-FLAIR mismatch sign have used visual assessment. This study quantified the degree of T2-FLAIR mismatch using digital subtraction of fluid-nulled T2-weighted FLAIR images from non-fluid-nulled T2-weighted images in human nonenhancing diffuse gliomas and then used this information to assess improvements in diagnostic performance and investigate subregion characteristics within these lesions. <h3>MATERIALS AND METHODS:</h3> Two cohorts of treatment-naïve, nonenhancing gliomas with known <i>IDH</i> and 1p/19q status were studied (<i>n</i> = 71 from The Cancer Imaging Archive (TCIA) and <i>n</i> = 34 in the institutional cohort). 3D volumes of interest corresponding to the tumor were segmented, and digital subtraction maps of T2-weighted MR imaging minus T2-weighted FLAIR MR imaging were used to partition each volume of interest into a T2-FLAIR mismatched subregion (T2-FLAIR mismatch, corresponding to voxels with positive values on the subtraction maps) and nonmismatched subregion (T2-FLAIR nonmismatch corresponding to voxels with negative values on the subtraction maps). Tumor subregion volumes, percentage of T2-FLAIR mismatch volume, and T2-FLAIR nonmismatch subregion thickness were calculated, and 2 radiologists assessed the T2-FLAIR mismatch sign with and without the aid of T2-FLAIR subtraction maps. <h3>RESULTS:</h3> Thresholds of ≥42% T2-FLAIR mismatch volume classified <i>IDH</i>-mutant astrocytoma with a specificity/sensitivity of 100%/19.6% (TCIA) and 100%/31.6% (institutional); ≥25% T2-FLAIR mismatch volume showed 92.0%/32.6% and 100%/63.2% specificity/sensitivity, and ≥15% T2-FLAIR mismatch volume showed 88.0%/39.1% and 93.3%/79.0% specificity/sensitivity. In <i>IDH</i>-mutant astrocytomas with ≥15% T2-FLAIR mismatch volume, T2-FLAIR nonmismatch subregion thickness was negatively correlated with the percentage T2-FLAIR mismatch volume (<i>P </i>&lt; .0001) across both cohorts. The percentage T2-FLAIR mismatch volume was higher in grades 3–4 compared with grade 2 <i>IDH</i>-mutant astrocytomas (<i>P </i>&lt; .05), and ≥15% T2-FLAIR mismatch volume <i>IDH-</i>mutant astrocytomas were significantly larger than &lt;15% T2-FLAIR mismatch volume <i>IDH</i>-mutant astrocytoma (<i>P </i>&lt; .05) across both cohorts. When evaluated by 2 radiologists, the additional use of T2-FLAIR subtraction maps did not show a significant difference in interreader agreement, sensitivity, or specificity compared with a separate evaluation of T2-FLAIR and T2-weighted MR imaging alone. <h3>CONCLUSIONS:</h3> T2-FLAIR digital subtraction maps may be a useful, automated tool to obtain objective segmentations of tumor subregions based on quantitative thresholds for classifying <i>IDH</i>-mutant astrocytomas using the percentage T2 FLAIR mismatch volume with 100% specificity and exploring T2-FLAIR mismatch/T2-FLAIR nonmismatch subregion characteristics. Conversely, the addition of T2-FLAIR subtraction maps did not enhance the sensitivity or specificity of the visual T2-FLAIR mismatch sign assessment by experienced radiologists.","journal":"American Journal of Neuroradiology","year":2024,"id":428822,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":11,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9597,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":954924,"name":"Francesco Sanvito","orcid":"0000-0003-3379-9958","position":1,"is_corresponding":false},{"id":411313,"name":"Vien Le","orcid":"0000-0003-2933-332X","position":2,"is_corresponding":false},{"id":1098637,"name":"Sonoko Oshima","orcid":"0000-0002-1453-3807","position":3,"is_corresponding":false},{"id":1230466,"name":"Ashley Teraishi","orcid":"0009-0004-3442-8109","position":4,"is_corresponding":false},{"id":396762,"name":"Jingwen Yao","orcid":"0000-0002-8828-1841","position":5,"is_corresponding":false},{"id":1071581,"name":"Donatello Telesca","orcid":"0000-0003-0773-451X","position":6,"is_corresponding":false},{"id":396763,"name":"Catalina Raymond","orcid":"0000-0003-2757-439X","position":7,"is_corresponding":false},{"id":297477,"name":"Whitney B. Pope","orcid":"0000-0003-4803-1992","position":8,"is_corresponding":false},{"id":396768,"name":"Phioanh L. Nghiemphu","orcid":"0000-0003-4064-6079","position":9,"is_corresponding":false},{"id":297478,"name":"Albert Lai","orcid":"0000-0002-7265-2986","position":10,"is_corresponding":false},{"id":247467,"name":"Timothy F. Cloughesy","orcid":"0000-0002-8656-7483","position":11,"is_corresponding":false},{"id":397177,"name":"Noriko Salamon","orcid":"0000-0002-3520-9467","position":12,"is_corresponding":false},{"id":247468,"name":"Benjamin M. Ellingson","orcid":"0000-0002-2764-6640","position":13,"is_corresponding":false},{"id":443406,"name":"Nicholas S. Cho","orcid":"0000-0002-8686-0575","position":0,"is_corresponding":true}],"reference_count":36,"raw_metadata":null,"created_at":"2026-07-19T01:59:02.165535Z","pmid":"38238098","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}