Data for: Low Dose T1W DCE-MRI for Early Time Points (ET) Perfusion Measurement in Patients with Intra-Cranial Tumors: A Pilot Study Applying the Microsphere Model to Measure Absolute Cerebral Blood Flow

A new “early time points” (ET) method, ACcomb, for absolute CBF estimation using low dose high temporal resolution (LDHT) whole brain 3D coverage T1W DCE MRI has been developed. Absolute CBF was derived based on average contrast agent concentration (AC) within an Early Time Points (ET) window. Previous authors have used singular value decomposition (SVD) to analyses T1W DCE data. In this study, we compared the CBF derived from the ACcomb with CBF estimates derived using SVD deconvolution of LDHT T1W DCE MRI data, and from T2*W DSC MRI data with preload of contrast agent, using a SVD method. MRI examination was carried out on a patient with glioblastoma multiforme (GBM) scanned at a 3T scanner. Low GBCA dose, high temporal resolution (LDHT) DCE-MRI data were collected as the first part of the dual temporal resolution technique, an improved coverage and spatial resolution—using dual injection dynamic contrast-enhanced (ICR-DICE), as described previously. Experiment data included in the folders of: 1) GM_WM_Tumor_segmentation: noTumor_seg1GM_17313.hdr/img: Analyze format data set of 3D probability map of grey matter; noTumor_seg1WM_17313.hdr/img: Analyze format data set of 3D probability map of white matter; rrtumor_mask17313.hdr/img: Analyze format data set of 3D mask image of a glioma. 2) AIF_TXT_PS_FILES: aif_gd_avg_20voxels17313.txt: a text file containing: 1) number of time points; 2) time lists; 3) contrast agent concentration list corresponding to the time list aif_fit17313.ps: a graph showing the plasma concentration-time curve of the first pass of the contrast agent bolus fitted with the gamma variate function aif_gd17313.ps: a graph showing the measured plasma concentration vs time curve 3) CBF&Ktrans&vp_maps_from_T1W_DCE_MRI: abscbf_ACcomb.hdr/.img: a 3D CBF map derived from LDHT T1W DCE MRI using the new ACcomb method. flow_svd_3d.hdr/.img: a 3D CBF map derived from LDHT T1W DCE MRI using the SVD method. ktran_min_sfe50.hdr/.imag and vp.hdr/.img: 3D CBF maps from the tracer kinetic analysis on the T1W-DCE MRI data using the extended Tofts model (ETM). 4) CBF_map_from_T2*W_DSC_MRI: rrCBF_MIstar_strip.hdr/.img: 3D CBF maps calculated from the T2*W DSC MRI data using the SVD method. 5) Descriptives_for_T1_CBF_ET_study: check_coregi_use_overlay.ppt: Figures to illustrate that all 3D/4D images, 3D tissues segmentation maps/masks and maps of perfusion (and permeability) are aligned with the same matrix size for quantification. Et_svd_t2star_cbf.ppt: Pixel-wise scatter plots for the demonstration of the relationship of CBF-ET-T1W, CBF-SVD-T1W and CBF-SVD-T2*. 3D_FFE_seq_diagram.PNG: Diagram of “3D FFE pulse sequence” used for acquiring the low dose high temporal resolution DCE and T1n MRI. 6) Pulse_sequence_for_LDHT_DCE_MRI: 3D_FFE_seq_diagram.png: a graph showing the diagram of 3D fast field echo (FFE) pulse sequence used for the LDHT-DCE-MRI

本研究开发了一种全新的"早期时间点（early time points, ET）"方法ACcomb，用于基于低剂量高时间分辨率（low dose high temporal resolution, LDHT）全脑三维覆盖T1加权动态对比增强磁共振成像（T1W DCE MRI）开展绝对脑血流量（cerebral blood flow, CBF）定量估算。绝对脑血流量基于早期时间点窗口内的对比剂平均浓度（average contrast agent concentration, AC）推导得到。既往研究已采用奇异值分解（singular value decomposition, SVD）对T1W DCE数据进行分析。本研究中，我们将ACcomb方法得到的CBF，与采用LDHT T1W DCE MRI数据的SVD反卷积得到的CBF估计值，以及采用SVD方法、预注射对比剂的T2*加权动态磁敏感对比磁共振成像（T2*W DSC MRI）数据得到的CBF估计值进行了对比。

磁共振成像检查在1台3T扫描仪上完成，受试者为多形性胶质母细胞瘤（glioblastoma multiforme, GBM）患者。低剂量钆基对比剂（gadolinium-based contrast agent, GBCA）高时间分辨率DCE-MRI数据作为双时间分辨率技术的第一部分采集获得，该技术采用了前文所述的改进覆盖范围与空间分辨率的双注射动态对比增强（dual injection dynamic contrast-enhanced, ICR-DICE）方案。

本实验数据包含以下文件夹：
1. GM_WM_Tumor_segmentation：
- noTumor_seg1GM_17313.hdr/img：灰质三维概率图的Analyze格式数据集；
- noTumor_seg1WM_17313.hdr/img：白质三维概率图的Analyze格式数据集；
- rrtumor_mask17313.hdr/img：胶质瘤三维掩码图像的Analyze格式数据集。
2. AIF_TXT_PS_FILES：
- aif_gd_avg_20voxels17313.txt：包含以下内容的文本文件：①时间点数量；②时间列表；③与时间列表对应的对比剂浓度列表；
- aif_fit17313.ps：采用伽马变量函数拟合的对比剂首过团块血浆浓度-时间曲线图谱；
- aif_gd17313.ps：实测血浆浓度-时间曲线图谱。
3. CBF&Ktrans&vp_maps_from_T1W_DCE_MRI：
- abscbf_ACcomb.hdr/.img：采用新型ACcomb方法从LDHT T1W DCE MRI中得到的三维CBF图；
- flow_svd_3d.hdr/.img：采用SVD方法从LDHT T1W DCE MRI中得到的三维CBF图；
- ktran_min_sfe50.hdr/.img与vp.hdr/.img：采用扩展Tofts模型（extended Tofts model, ETM）对T1W-DCE MRI数据进行示踪剂动力学分析得到的三维CBF图。
4. CBF_map_from_T2*W_DSC_MRI：
- rrCBF_MIstar_strip.hdr/.img：采用SVD方法从T2*W DSC MRI数据中计算得到的三维CBF图。
5. Descriptives_for_T1_CBF_ET_study：
- check_coregi_use_overlay.ppt：用于展示所有三维/四维图像、组织三维分割图/掩码以及灌注（及通透性）图均采用统一矩阵尺寸以实现定量分析的图示；
- Et_svd_t2star_cbf.ppt：用于展示CBF-ET-T1W、CBF-SVD-T1W与CBF-SVD-T2*之间相关性的逐像素散点图；
- 3D_FFE_seq_diagram.PNG：用于采集LDHT DCE与T1n MRI的"三维快速场回波（fast field echo, FFE）脉冲序列"示意图。
6. Pulse_sequence_for_LDHT_DCE_MRI：
- 3D_FFE_seq_diagram.png：展示LDHT-DCE-MRI所用三维快速场回波脉冲序列结构的图谱。