Low-dose T1W DCE-MRI for early time points perfusion measurement in patients with intracranial tumors: A pilot study applying the microsphere model to measure absolute cerebral blood flow.

Abstract

BACKGROUND:

Previous studies have measured cerebral blood flow (CBF) with DSC-MRI using an "early time points" (ET) method based on microsphere theory.

PURPOSE:

To develop and assess a new ET method for absolute CBF estimation using low-dose high-temporal (LDHT) T1W-DCE-MRI.

STUDY TYPE:

Retrospective cohort study.

SUBJECTS:

Seven patients with sporadic vestibular schwannoma (VS) who underwent test-retest imaging; one patient with glioblastoma multiforme (GBM) imaged pretreatment; and 12 neurofibromatosis type 2 (NF2) patients undergoing bevacizumab treatment, imaged pre- and 90 days posttreatment.

FIELD STRENGTH/SEQUENCE:

LDHT-DCE-MRI was performed at 1.5 and 3.0T, using 3D spoiled gradient echo with phase cycling. DSC-MRI performed in one patient, using 3D echo-shifted multi-shot echo-planar imaging (PRESTO) at 3T.

ASSESSMENT:

Through Monte Carlo simulations, CBF estimation using three newly developed average contrast agent concentration (AC) -based methods (ACrPK, ACrMG, ACcomb), was compared against conventional maximum gradient (MG) approaches, at varying Rician noise levels. Reproducibility and applicability of the ACcomb method was assessed in our sporadic-VS/GBM/NF2 patient cohort, respectively.

STATISTICAL TESTS:

Reproducibility was measured using test-retest coefficient of variation (CoV). Pre- and posttreatment CBF values were compared using paired t-test with Bonferroni correction.

RESULTS:

Monte Carlo stimulations demonstrated that AC-based methods, particularly ACcomb, offered superior accuracy to conventional MG approaches. Overall test-retest CoV using the ACcomb method was 5.76 in normal-appearing white matter (NAWM). The new ACcomb method produced gray matter/white matter CBF estimates in the NF2 patient cohort of 55.9 ± 13.9/25.8 ± 3.5 on day 0; compared with 155.6 ± 17.2/128.4 ± 29.1 for the classical MG method. There was a moderate (10% using ACcomb and ACrPK) increase in CBF of NAWM 90 days post therapy (P = 0.03 and 0.005).

DATA CONCLUSION:

Our new AC-based method of CBF estimation offers excellent reproducibility, and displays more accuracy in both Monte Carlo analysis and clinical data application, than conventional MG-based approaches.

LEVEL OF EVIDENCE:

1 Technical Efficacy: Stage 4 J. MAGN. RESON. IMAGING 2018;48:543-557.

• Authors: Ka-Loh Li, Daniel Lewis, Alan Jackson, Sha Zhao, Xiaoping Zhu
• Journal: Journal of magnetic resonance imaging : JMRI (J Magn Reson Imaging) Vol. 48 Issue 2 Pg. 543-557 (08 2018) ISSN: 1522-2586 [Electronic] United States
• PMID: 29473980 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2018 International Society for Magnetic Resonance in Medicine.

Chemical References

• Bevacizumab

Topics

• Aged
• Bevacizumab (therapeutic use)
• Brain Neoplasms (diagnostic imaging)
• Cerebrovascular Circulation
• Female
• Glioblastoma (diagnostic imaging)
• Humans
• Imaging, Three-Dimensional
• Magnetic Resonance Imaging (methods)
• Male
• Microspheres
• Middle Aged
• Models, Statistical
• Monte Carlo Method
• Neurilemmoma (diagnostic imaging)
• Neurofibromatosis 2 (diagnostic imaging)
• Pilot Projects
• Reproducibility of Results
• Retrospective Studies
• Time Factors