Queensland Twin IMaging (QTIM)

We present the Queensland Twin IMaging (QTIM) dataset: a multimodal neuroimaging dataset of young adult twins and siblings (18-30 years, N = 1026), including a subsample of participants, scanned a second time to assess test-retest reliability (N = 78, test-retest interval ~ 3.5 months). The QTAB dataset additionally includes adolescent twins scanned at age 12 (N = 88) or 16 (N = 88) years. Approximately a third of these 12- and 16-year-old participants were scanned four years later as part of a longitudinal pilot study (scanned at 12 and 16 years N = 24, scanned at 16 and 20 years N = 38). Scanning parameters and acquisition details are detailed elsewhere (see "How to Acknowledge").

Data Record

Basic demographic data (age [rounded down], sex, handedness, family_id [to denote non-independent participants]) is provided at the top-level of the dataset directory in participants.tsv (variables and properties described in participants.json). Zygosity and limited non-imaging phenotypic data are available for QTIM participants. A data transfer agreement and institutional ethics approval are required for access; for more information, please contact Dr Lachlan Strike, QIMR Berghofer Medical Research Institute (lachlan [dot] strike [at] qimrberghofer [dot] edu [dot] au). Cortical and subcortical brain measures extracted using FreeSurfer v5.3 are provided under derivatives/freesurfer_5.3. The extraction and quality checking of these measures is detailed in Strike et al., 2019 (see "How to Acknowledge"). Hippocampal subfield measures extracted using Freesurfer v6 (using the base reconstruction from FreeSurfer v5.3) are also provided.
MRIQC image quality metrics (IQMs) for T1w images are provided under derivatives/mriqc.

Usage Notes

Due to a scanner software upgrade, the QTIM T1w sequence was modified during data collection (slice number decreased 256 to 240, acquisition orientation changed from a coronal (80% of participants) to a sagittal (20% of participants) direction). This change is indexed by the "ses01_T1w_acq" and "ses02_T1w_acq" variables in "participants.tsv". Please note that a prominent vascular pulsation artefact in the T1w images varies with the acquisition orientation. Investigators should consider whether a statistical adjustment is sufficient to control these effects or whether participants should be restricted to a single acquisition orientation.

The onset of the n-back task was delayed such that the first trial was coincident with the 6th volume acquired. As such, the initial 5 volumes of the n-back scan should be removed to ensure that steady-state tissue magnetization was reached. In the 12-year-old participant subsample, the n-back stimulus presentation time was increased to from 1 to 1.5 seconds midway through the project (younger participants had difficulty with the 1 sec presentation). The "nback_seq" variable in "participants.tsv" denotes whether 12-year-old participants completed the 1 or 1.5 second n-back task.

本研究发布昆士兰双生子成像（Queensland Twin IMaging, QTIM）数据集：该数据集面向18至30岁的青年双生子及同胞群体（共1026名受试者），为多模态神经影像学数据集，其中包含一个子样本（78名受试者）接受了二次扫描以评估重测信度，两次扫描间隔约3.5个月。QTAB数据集额外纳入了在12岁（88名）或16岁（88名）时接受扫描的青少年双生子。上述12岁及16岁受试者中，约三分之一在四年后接受了二次扫描，作为纵向预实验的一部分：其中24名受试者分别在12岁和16岁时接受扫描，38名受试者分别在16岁和20岁时接受扫描。扫描参数与采集细节详见其他资料（参见"How to Acknowledge"）。

数据记录
数据集根目录下的participants.tsv文件包含基础人口统计学数据：包括取整后的年龄、性别、利手性以及用于标识非独立受试者的family_id字段（变量与属性详情参见participants.json）。QTIM数据集的受试者还可获得双生子卵型信息及有限的非影像表型数据。如需获取该数据集，需签署数据传输协议并获得机构伦理委员会批准；详细信息请联系昆士兰医学研究所（QIMR Berghofer Medical Research Institute）的Lachlan Strike博士，联系方式：lachlan[dot]strike[at]qimrberghofer[dot]edu[dot]au。使用FreeSurfer v5.3提取的大脑皮层及皮层下结构指标存储于derivatives/freesurfer_5.3目录下。该类指标的提取与质量控制流程详见Strike等人2019年的研究（参见"How to Acknowledge"）。此外还提供了基于FreeSurfer v5.3的基础重建结果、使用Freesurfer v6提取的海马亚区指标。T1加权成像（T1w）的MRIQC图像质量指标（IQMs）存储于derivatives/mriqc目录下。

使用说明
由于扫描仪软件升级，QTIM数据集的T1加权成像（T1w）序列在数据采集过程中进行了调整：扫描层数从256层降至240层，采集方位从冠状位（覆盖80%受试者）改为矢状位（覆盖20%受试者）。该序列调整信息可通过participants.tsv文件中的"ses01_T1w_acq"与"ses02_T1w_acq"变量进行检索。需注意，T1w图像中存在明显的血管搏动伪影，其表现随采集方位不同而存在差异。研究人员需评估是否可通过统计校正控制该类伪影影响，或是应将受试者限定为单一采集方位的样本。

n-back任务的启动时间存在延迟，使得首个试次与采集到的第6幅图像同步。因此，需剔除n-back扫描的前5幅图像，以确保脑组织磁化达到稳态。在12岁受试者子样本中，项目进行中期将n-back任务的刺激呈现时长从1秒调整至1.5秒（因低龄受试者难以完成1秒呈现的任务）。participants.tsv文件中的"nback_seq"变量可标识12岁受试者完成的是1秒还是1.5秒时长的n-back任务。

搜集汇总

背景与挑战

背景概述

Queensland Twin IMaging (QTIM) 是一个多模态神经影像数据集，包含1026名18-30岁的年轻成人双胞胎和兄弟姐妹的脑部扫描数据，其中78名参与者进行了第二次扫描以评估测试-重测可靠性。数据集还包括12岁和16岁青少年双胞胎的扫描数据，部分参与者进行了纵向研究。数据集提供了基本的 demographic 数据、FreeSurfer 提取的皮质和皮质下脑部测量值，以及 MRIQC 图像质量指标。