·LCModel软件相关论文分享——磁共振频谱数据定量后处理技术比较
LCModel 软件是一款频谱定量软件。操作完全自动化，能直接输出代谢物出的绝对浓度，兼容 Siemens, GE, Philips 等各大厂商和不同扫描序列（PRESS, STEAM等）的波谱数据。该软件经过18年的开发和全世界超过500家大型科研院所的试用，已逐渐成为事实上的波谱数据规范后处理平台。HMRRC于2010年引进了LCModel并将利用该软件对多种疾病，尤其是神经精神疾病展开研究。
当前LCModel的新版本为6.3，在该版本中，主要升级的内容有：
1、用MEGA-PRESS估算GABA 。
2、改进了较弱代谢物的估计，特别是谷氨酰胺。
3、改进肌肉，脂质，乳腺和肝脏光谱分析。
磁振造影 (MRI) 与磁振频谱 (MRS) 具有非侵入性探测的特色，所以被广泛地发展以应用在临床分析的研究上。
近年来随著MRS应用于临床的例子增加，所以也发展出许多针对后处理的工具软件，其中广为人知的后处理软件为LCModel。LCModel 是套被广泛使用的磁振频谱分析软体。采用了图形操作介面让使用者对于磁振频谱影像的分析达到方便以及简洁的目的。LCMgui 是其在Linux系统中的图形使用者介面，可以转换多种磁振频谱档案格式到LCModel可处理的档案格式。
特征
算法的小改进意味着结果会略有不同。
对光谱的分析主要是脂质(以及水，可能是胆碱)，如脊椎、乳房和肝脏
肌谱分析
导入到电子表格程序的输出文件
通用多通道(相控阵)档案。
同时分析水信号的左边和右边
对脂质和大分子信号的估计，特别是对肿瘤和病变的评估
交互式选择和分析MRSI切片的矩形子集
Bruker、西门子公司和东芝的数据与LCMgui
多用户安装LCMgui
使用LCMgui中的扩展来归档文件
LCMgui用户配置文件
使用LCMgui进行多个分析的批处理
选择通用电气LX(和更高)框架的子集
文件名过滤器在LCMgui文件选择器中
更方便地处理非共振谱
模拟基础光谱
对浓度比率施加“软约束”
相干平均谱(如:从相控阵)
Features
Small improvements in the algorithms mean that the results will differ slightly.
Analysis of spectra with mainly lipid (and water plus possibly choline), as in vertebra,breast and liver.
Small improvements in the algorithms mean that the results will differ slightly.
Analysis of muscle spectra, particularly for IMCL.
Bruker ParaVision-3 files.
Output file for import to spreadsheet programs.
In multi-voxel analyses: combining PostScript files into one file; skipping over bad voxels.
GE multi-channel (phased-array) P-files.
Simultaneously analyzing a spectrum left & right of the water signal.
Estimation of lipid and macromolecule signals, especially for tumors and lesions.
Interactive selection and analysis of rectangular subsets of MRSI slices.
Bruker, Siemens syngo and Toshiba data with LCMgui.
Multi-User installations of LCMgui.
Archiving files using extensions in LCMgui.
LCMgui user profiles, e.g., for 1.5T & 3T data or Siemens & GE data on the same user account.
Batch processing of multiple analyses with LCMgui).
Selecting a subset of GE LX (and higher) frames, e.g., to eliminate bad frames due to patient motion.
Filename filters in the LCMgui File Selector.
More convenient handling of off-resonance spectra.
Simulating your own basis spectra.
Imposing "soft constraints" on concentration ratios.
Coherent averaging of spectra (e.g., from phased arrays).
Going back toward the old Version 5, e.g., for improved (but not perfect) consistency in large longitudinal studies.
The normal usage is to supply the time-domain data as a simple text file to LCModel. A possible alternative is the LCMgui graphical user interface:
Freely available for use with LCModel.
Simplified usage, often only with mouse clicks, in two steps:
1.Select the data with the File Selector;
2.Start LCModel (optionally checking and modifying any settings) in the Control Window.
Currently for the following single-voxel data:
*Bruker ParaVision fid files (if necessary, converted by you to analog mode with Bruker's convdta).
*GE 5.x Probe raw P-files and spectrum G-files.
*GE Probe raw P-files, including (new) Signa 22 P-files. Also for P-files with multi-channel (phased-array) data.
*Hitachi data: part of the Hitachi software; no need to purchase separately.
*Philips SDAT & SPAR files.
*Picker (later Marconi, now Philips) DUMP files.
*Siemens *rda files transferred from the syngo PC console and Siemens raw files from the (old) Numaris-3 Unix console.
*Toshiba rawData files and Version 7.xx (and later) DICOM files;
*Varian/Agilent fid files;
*Other data types using your own conversion script.
Currently for the following MRSI data:
*Philips, Siemens & Toshiba data, including interactive display, selection and analysis of full 2D slices or rectangular subsets. (Instructions in Sec. 3.7 of the LCModel Manual.)
*Other data types using your own conversion script;
*For GE MRSI (and single-voxel) data, Mary McLean's LCModel interface [MA McLean et al, Magn Reson Med 44, 401 (2000)] is integrated into GE's SAGE Research version (from SAGE Dev2002.1).
软件操作系统要求:
A Linux PC with an AMD or Intel processor(s) (including x86-64). No Microsoft or Apple versions are planned.
You must be able to print or display PostScript files (or convert PostScript, e.g., to PDF with Adobe Acrobat Distiller).
An X-windows display. (This is checked for you in Step 2 of the test run below.)
A monitor with reasonable resolution (at least 1024 x 768).
You log on under your normal username (not root);
And you can at any time completely remove your installed package (including all output from the tests) with the command: $HOME/.uninstall-lcmodel
计算机硬件要求：
An LCModel analysis makes full use of one processor's speed and CPU cache memory. It makes no use of multiple processors (unless several analyses run simultaneously).
There is very little input/output or demands on graphics, memory or disk storage.
512 MB of memory should be sufficient, at least for a single user.
LCModel should run with almost any Linux distribution from 2001 or later. Most popular are Ubuntu, Red Hat & CentOS.
You should check all of this on your own computer with the free download and test runs. | 
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