Moving Toward a Consensus DSC-MRI Protocol: Validation of a Low-Flip Angle Single-Dose Option as a Reference Standard for Brain Tumors

• Published in: American journal of neuroradiology : AJNR Vol. 40; no. 4; pp. 626 - 633
• Main Authors: Schmainda, K M, Prah, M A, Hu, L S, Quarles, C C, Semmineh, N, Rand, S D, Connelly, J M, Anderies, B, Zhou, Y, Liu, Y, Logan, B, Stokes, A, Baird, G, Boxerman, J L
• Format: Journal Article
• Language: English
• Published: United States American Society of Neuroradiology 01.04.2019
• Subjects: Adult; Adult Brain; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - pathology; Consensus; Contrast Media; Editor's Choice; Female; Humans; Image Interpretation, Computer-Assisted - methods; Image Interpretation, Computer-Assisted - standards; Magnetic Resonance Imaging - methods; Magnetic Resonance Imaging - standards; Male; Neuroimaging - methods; Neuroimaging - standards; Organometallic Compounds; Reference Standards
• ISSN: 0195-6108; 1936-959X
• DOI: 10.3174/ajnr.A6015

DSC-MR imaging using preload, intermediate (60°) flip angle and postprocessing leakage correction has gained traction as a standard methodology. Simulations suggest that DSC-MR imaging with flip angle = 30° and no preload yields relative CBV practically equivalent to the reference standard. This study tested this hypothesis in vivo. Eighty-four patients with brain lesions were enrolled in this 3-institution study. Forty-three patients satisfied the inclusion criteria. DSC-MR imaging (3T, single-dose gadobutrol, gradient recalled-echo-EPI, TE = 20-35 ms, TR = 1.2-1.63 seconds) was performed twice for each patient, with flip angle = 30°-35° and no preload (P-), which provided preload (P+) for the subsequent intermediate flip angle = 60°. Normalized relative CBV and standardized relative CBV maps were generated, including postprocessing with contrast agent leakage correction (C+) and without (C-) contrast agent leakage correction. Contrast-enhancing lesion volume, mean relative CBV, and contrast-to-noise ratio obtained with 30°/P-/C-, 30°/P-/C+, and 60°/P+/C- were compared with 60°/P+/C+ using the Lin concordance correlation coefficient and Bland-Altman analysis. Equivalence between the 30°/P-/C+ and 60°/P+/C+ protocols and the temporal SNR for the 30°/P- and 60°/P+ DSC-MR imaging data was also determined. Compared with 60°/P+/C+, 30°/P-/C+ had closest mean standardized relative CBV ( = .61), highest Lin concordance correlation coefficient (0.96), and lowest Bland-Altman bias (μ = 1.89), compared with 30°/P-/C- ( = .02, Lin concordance correlation coefficient = 0.59, μ = 14.6) and 60°/P+/C- ( = .03, Lin concordance correlation coefficient = 0.88, μ = -10.1) with no statistical difference in contrast-to-noise ratios across protocols. The normalized relative CBV and standardized relative CBV were statistically equivalent at the 10% level using either the 30°/P-/C+ or 60°/P+/C+ protocols. Temporal SNR was not significantly different for 30°/P- and 60°/P+ ( = .06). Tumor relative CBV derived from low-flip angle, no-preload DSC-MR imaging with leakage correction is an attractive single-dose alternative to the higher dose reference standard.