Use of T1 relaxation time in rotating frame (T1ρ) and apparent diffusion coefficient to estimate cerebral stroke evolution

• Published in: Journal of magnetic resonance imaging Vol. 48; no. 5; pp. 1247 - 1254
• Main Authors: Tan, Yuefa, Xu, Jun, Chen, Ruiying, Chen, Bin, Xu, Juan, Ren, Daokun, Chan, Queenie, Mei, Yingjie, Wu, Yuankui, Xu, Yikai
• Format: Journal Article
• Language: English
• Published: Nashville Wiley Subscription Services, Inc 01.11.2018
• Subjects: acute stroke; apparent diffusion coefficient; brain ischemia; Correlation analysis; Diagnostic systems; Diffusion; Diffusion coefficient; Females; Field strength; Ischemia; Lesions; Magnetic resonance imaging; Males; Medical imaging; Parenchyma; Patients; Population (statistical); Population studies; Relaxation time; Rotation; Sensitivity analysis; Statistical analysis; Statistical tests; Stroke; T1ρ
• ISSN: 1053-1807; 1522-2586; 1522-2586
• DOI: 10.1002/jmri.25971

Background The major factor for the appropriate treatment strategies for ischemia patients is its onset timing. Purpose/Hypothesis To study to evaluate the diagnostic accuracy of T1 relaxation time in a rotating frame (T1ρ) and apparent diffusion coefficient (ADC) from MRI to estimate ischemia stages. Study Type Prospective. Population/Subjects/Phantom/Specimen/Animal Model In all, 73 patients (49 males, aged 29–78 years and 24 females, aged 22–94 years) with ischemia were prospectively imaged with T1ρ and diffusion MRI during the postischemic period. Field Strength/Sequence 3T/T1ρ and diffusion‐weighted imaging (DWI). Assessment Ischemic parenchyma included tissue with elevated signal areas on DWI and correlative hypointense areas on ADC maps. Statistical Tests The sensitivity of variables to ischemia time was quantified by analyzing the respective correlations of these values with onset time. Results ΔT1ρ (ipsilateral‐contralateral differences in T1ρ) (R2 = 0.956) and T1ρipsi (ipsilateral ischemia T1ρ values) (R2 = 0.941) were elevated in all ischemic lesions; these values increased linearly as a function of time, unlike ΔADC (ipsilateral‐contralateral differences in ADC) (R2 = –0.410) and ADCipsi (ipsilateral ischemia ADC values) (R2 = 0.550). ΔT1ρ and T1ρipsi were significantly different between all stages (P < 0.01), except the acute and hyperacute stages (P = 0.589 for ΔT1ρ, P = 0.290 for T1ρipsi, respectively), but ΔADC and ADCipsi only between the late subacute and early subacute stages (P < 0.01) and the late subacute and chronic stages (P < 0.01). Data Conclusion These data suggest that T1ρ can provide estimates for the ischemic time in patients. T1ρ has the potential to outperform diffusion for single‐timepoint examination because the T1ρ change during strokes is positive and linear. If patients with suspected stroke are scanned by MRI within the appropriate timeframe, T1ρ may provide tools for evaluating stroke onset, potentially aiding in treatment strategies. Level of Evidence: 4 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1247–1254.