颅内肿瘤患者早期时间点的低剂量 T1W DCE-MRI 灌注测量：应用微球模型测量绝对脑血流的初步研究。

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.

机构信息

Division of Informatics, Imaging and Data Science, The University of Manchester, 27 Palatine Road, Manchester, United Kingdom.

Department of Neurosurgery, Salford Royal NHS Foundation Trust, Scott Lane, Salford, Manchester, United Kingdom.

出版信息

J Magn Reson Imaging. 2018 Aug;48(2):543-557. doi: 10.1002/jmri.25979. Epub 2018 Feb 23.

DOI:10.1002/jmri.25979

PMID:29473980

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.

摘要

背景

先前的研究使用基于微球理论的“早期时间点”（ET）方法通过 DSC-MRI 测量脑血流（CBF）。

目的

开发和评估一种新的 ET 方法，用于使用低剂量高时间（LDHT）T1W-DCE-MRI 进行绝对 CBF 估计。

研究类型

回顾性队列研究。

受试者

七名患有散发性前庭神经鞘瘤（VS）的患者进行了重复成像；一名患有多形性胶质母细胞瘤（GBM）的患者在治疗前进行了成像；12 名神经纤维瘤病 2 型（NF2）患者接受贝伐单抗治疗，治疗前和治疗后 90 天进行了成像。

磁场强度/序列：使用具有相位循环的 3D 扰相梯度回波在 1.5 和 3.0T 上进行 LDHT-DCE-MRI。在 3T 上使用 3D 移相多射回波平面成像（PRESTO）对一名患者进行 DSC-MRI。

评估

通过蒙特卡罗模拟，比较了三种新开发的基于平均对比剂浓度（AC）的方法（ACrPK、ACrMG、ACcomb）与传统的最大梯度（MG）方法在不同瑞利噪声水平下的 CBF 估计值。分别评估了我们的散发性 VS/GBM/NF2 患者队列中 ACcomb 方法的可重复性和适用性。

统计检验

使用重复测试的变异系数（CoV）来测量可重复性。使用配对 t 检验和 Bonferroni 校正比较治疗前后的 CBF 值。

结果

蒙特卡罗模拟表明，基于 AC 的方法，特别是 ACcomb，比传统的 MG 方法具有更高的准确性。使用 ACcomb 方法的总体重复测试 CoV 在正常外观的白质（NAWM）中为 5.76。新的 ACcomb 方法在 NF2 患者队列中产生的灰质/白质 CBF 估计值为 0 天的 55.9±13.9/25.8±3.5；而经典 MG 方法为 155.6±17.2/128.4±29.1。治疗后 90 天，NAWM 的 CBF 适度增加（10% 使用 ACcomb 和 ACrPK）（P=0.03 和 0.005）。