Reliability and validity of subjective radiologist reporting of temporal changes in lumbar spine MRI findings.

BACKGROUND: The importance of lumbar findings on magnetic resonance imaging (MRI) remains controversial. Changes in lumbar MRI findings over time may provide important insights into the causes of low back pain. However, the reliability and validity of temporal changes are unknown. OBJECTIVE: To (1) investigate the interrater reliability of subjective radiologist reporting of temporal changes in lumbar spine MRI findings and (2) determine how commonly temporal changes are reported when two scans are conducted 30 minutes apart (considered false positives). DESIGN: Cross-sectional study. SETTING: Radiology clinic. PARTICIPANTS: Forty volunteers (mean age 40; 53% female) with current (n = 31) or previous (n = 9) low back pain underwent initial lumbar MRI on a single 3T scanner. Participants then lay on a bed for 30 minutes before undergoing an identical MRI. In addition, we purposely selected five participants from a previous study with repeat lumbar MRI scans where temporal changes were reported in at least one MRI finding (1-12 weeks after initial scan) and another five participants where no temporal change was reported. The 10 participants were included in analyses for aim 1 only. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Two blinded radiologists reported on temporal changes between the baseline and repeat scan for 12 different MRI findings (eg, disk herniation, annular fissure) at five levels. RESULTS: The interrater reliability of subjective reporting of temporal changes was poor for all MRI findings based on Kappa values (≤ 0.24), but agreement was relatively high (≥ 90.8%). This is explained by the low prevalence of temporal changes as demonstrated by high values for Prevalence and Bias Adjusted Kappa (≥ 0.82). "False positive" temporal changes were reported by at least one radiologist for most MRI findings, but the rate was generally low. CONCLUSIONS: Caution is required when interpreting temporal changes in lumbar MRI findings owing to low reliability and some false positive reporting.

Magnetic Resonance Spectroscopic Assessment of Isocitrate Dehydrogenase Status in Gliomas: The New Frontiers of Spectrobiopsy in Neurodiagnostics.

BACKGROUND: In the era of integrated genomic-histologic analysis of brain tumors, new biomarkers have been introduced as diagnostic, prognostic, and therapeutic indicators. The analysis of the mutation in the isocitrate dehydrogenase (IDH) genes IDH1 and IDH2 has provided important diagnostic and prognostic information for patients affected by diffuse glioma (i.e., the presence of the mutation has been related to an increased survival rate). The reference standard of IDH mutation detection has been its assessment in surgical specimens, immunohistochemistry, and/or genetic sequencing. Knowing the IDH status information preoperatively would be of great importance, because it has been related to tumor progression and the response to treatment. The oncometabolite 2-hydroxyglutarate (2HG), accumulated in gliomas with IDH mutation status, can be detected in vivo using magnetic resonance spectroscopy (MRS). METHODS: The 2HG-MRS technique remains technically challenging. We have summarized the results of the first pilot study in Australia, which included 10 patients affected by glioma. The data recorded from May 2017 to November 2018 were analyzed. RESULTS: In our exploratory study, we reached a sensitivity and specificity of 100%, confirming the strong predictive role of 2HG, as detected using MRS, in the diagnosis of glioma. CONCLUSION: In the present study, we have focused on methodological tips and future perspectives of the technique in the neuroimaging and neuro-oncological scenario. We would advocate the integration of 2HG-MRS into standard clinical practice.