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實作課程


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燈號說明

審定:無
翻譯:莊凱翔(簡介並寄信)
編輯:朱學(簡介並寄信)

雖非必要,但對MATLAB有一點經驗與基本的瞭解,會對這些習題很有幫助。關於MATLAB的說明與資料,可以參考MATLAB 6.x的說明文件中關於運用矩陣這個章節。若是不瞭解課程中會看到的MATLAB程式碼中的指令,可用help這個指令來得到相關的資訊。
Although not essential, a little experience with and understanding of the basics of MATLAB® will help in these exercises. One source of MATLAB® help and documentation may be found in Manipulating Matrices, which is part of the MATLAB® 6.x documentation. If you don't understand a command in the MATLAB® code fragments you will see below, you can use the help command to get information on it.




實驗0:介紹功能性磁振造影中用到的MATLAB程式
Lab 0: Introduction to MATLAB® for fMRI

這個實驗中包含一些使用指引,告訴你如何用MATLAB來觀看腦影像,並跟血液動態反應函數做疊積運算。
This lab consists of some tutorial files that will show you how to use MATLAB® to view brain images and convolve with a hemodynamic response function (HRF).

在本實驗中,將進行兩組引導練習,每一組會花約40分鐘。第一組將學到怎麼使用MATLAB的指令列語法,並介紹一些功能性磁振造影的專有名詞與概念。第二組將學習如何用影像視覺化套裝軟體來互動式地探索功能性磁振造影資料。
You will be running through two sets of tutorial exercises in this lab. Each set should take approximately 40 minutes. The first set of exercises gives you a chance to work with MATLAB® command line syntax and introduces some functional MRI terminology and concepts. The second provides an opportunity to use an image visualization software package for interactive exploration of fMRI data.



實驗1:資料擷取實驗
Lab 1: Data Acquisition Lab

實驗1大綱(PDF)
Lab 1 Outline (PDF)
實驗1手冊(PDF)
Lab 1 Manual (PDF)

*請注意:跟實驗有關的資料與檔案目前尚未提供
*Note that the data and files associated with the labs are not available at this time.

在這個分析實驗裡,將會檢視在不同空間解析度、造影速度及射頻接收線圈下取得的功能性磁振造影資料的時域信號,並運用Dview這個MATLAB下的程式來觀察這些信號。
In this analysis lab you will examine time-domain signals from fMRI datasets acquired using different spatial resolutions, imaging rates, and RF receive coils. You will use a MATLAB®-based program called Dview to examine these signals.

請注意:雖非必要,但對MATLAB有一點經驗與基本的瞭解,會對這些習題很有幫助。關於MATLAB的說明與資料,可以參考MATLAB 6.x的說明文件中關於運用矩陣這個章節。若是不瞭解課程中會看到的MATLAB程式碼中的指令,可用help這個指令來得到相關的資訊。
Note: Although not essential, a little experience with and understanding of the basics of MATLAB® will help in these exercises. Sources of MATLAB® help and documentation include Manipulating Matrices , which is part of the MATLAB® 6.x documentation. If you don't understand a command in the MATLAB® code fragments you will see below, you can use the help command to get information on it.

資料擷取與分析實驗的主要目的如下:
The main objectives of the data acquisition and analysis labs are:

  • 熟悉一般的功能性磁振造影環境,包括從資料擷取到離線顯示與分析。
    Familiarization of students with a typical functional MRI scanning environment, from data acquisition to offline visualization and analysis.
  • 用假體(無生命的測試樣品)來取得影像並檢視資料,以探討諸如影像信號不均勻、儀器產生的空間與時間雜訊,以及射頻接收線圈特性等現象。
    Acquisition and examination of image data from a phantom (inert test sample) to investigate image intensity non-uniformity, spatial and temporal noise from instrumental sources, and RF receive coil properties.
  • 在人身上取得影像並檢視資料,藉由切面影像來熟悉解剖構造的三維視覺化呈現,並比較來自生理與儀器的雜訊。
    Acquisition and examination of human data to gain familiarity with 3D anatomic visualization using cross-sectional images and compare physiological and instrumental sources of noise.


實驗2:生理實驗
Lab 2: Physiology Lab

實驗2大綱(PDF)
Lab 2 Outline (PDF)
實驗2手冊(PDF)
Lab 2 Manual (PDF)

*請注意:跟實驗有關的資料與檔案目前尚未提供
*Note that the data and files associated with the labs are not available at this time.

本實驗的目的在於讓學生熟悉整體的生理變動對血氧濃度變化信號的影響。因為一些實驗計畫可能會導致不預期的生理改變,瞭解這些影響在功能性磁振造影中是很重要的,例如在認知實驗中,對於正確執行作業的極度專注或焦慮,將使受試者改變他們的呼吸,而我們將在實驗中看到,即使是不怎麼大的呼吸率改變,都會對血氧濃度變化功能性磁振造影信號有很大的影響。
The purpose of this lab is to familiarize you with the effects of global physiological changes on the BOLD signal. It is important to be aware of such effects in fMRI because some experimental protocols may lead to unintentional physiological changes. An example would be a cognitive experiment in which intense concentration or anxiety about performing the task correctly leads subjects to change their breathing. As you will see in this lab, even a modest shift in breathing rate can have a significant effect on the BOLD fMRI signal.

探討血氧濃度變化對整體生理變動的反應的另一個理由是,這是個觀察血氧濃度變化靈敏度的區域差異的好方法。同樣的血流改變所導致的血氧濃度變化信號變化,在腦的不同部位會有不同的大小,端視局部的血管密度以及靜態下特定組織的生理狀態而定。由於很難確定激發不同區域的刺激是等值的,這很難用神經元模擬來探討。而在本實驗中使用的呼吸擾動則提供了一個避開這個問題的途徑,因為這種整體的擾動對於腦的所有部分會有同時、相似的影響。
Another reason for studying BOLD responses to global physiological changes is that this is a good way to examine regional differences in BOLD sensitivity. The fractional change in BOLD signal for a given change in blood flow can vary in different parts of the brain, depending on the local density of blood vessels and the physiological state of the particular tissues at rest. It's difficult to study this using neuronal stimulation, because there's no easy way to ensure equivalence of the stimuli used to activate different regions. Respiratory perturbations like the one used in this lab provide a good way to circumvent this problem, because as global perturbations they have a simultaneous and similar effect on all parts of the brain.

在這個實習中,將會要求做多次的觀察與問答。實驗報告將總結這些觀察與答案,所以要確定做好筆記並把結果列印出來。
In the exercises you will be asked to make a number of observations and answer questions. Your lab report will be the summary of these observations and answers, so be sure to make notes and printouts as you go.

在這個實習中,將要觀察適度但持續的呼吸改變對血氧濃度變化功能性磁振造影信號的影響。在實驗中,我們將取得多組的血氧濃度變化EPI影像,在其中的三組,受試者會進行不同組合的呼吸改變與神經活化:
In the exercises you will examine the effects of a relatively modest but sustained change in breathing on the BOLD fMRI signal. In the data acquisition component of this lab, we acquired a number of BOLD EPI datasets including three during which the subject underwent different combinations of breathing change and neuronal activation:

  • 視覺刺激的同時,右手進行手指運動:(使用作業兩字是否為此領域之習慣?或者有更好之替代用語?)(task在心理實驗設計中一般都翻成作業,是很怪異沒錯,故改為手指運動):在這個7分鐘長的掃瞄中,受試者在從第三分鐘開始到第四分鐘結束期間會受到視覺刺激,在接受視覺刺激的這兩分鐘,將同時被要求反覆地輕觸右手手指,而在其他的時間裡(最開始的兩分鐘,及從第五到第七分鐘結束)則觀看均勻的灰幕且不移動手指。
    visual stimulation and simultaneous right-hand movement task: in this seven minute long scanning run, the subject was exposed to a visual stimulus throughout the third and fourth minutes. The subject was also instructed to perform repetitive finger tapping movements with her right hand for the two minute period that the visual stimulus was on. During the rest of the scan (the first two minutes and the fifth through seventh minutes) she viewed a uniform grey screen and did not move her hand.

  • 深呼吸,沒有作業:在這個同樣是7分鐘的掃瞄中,受試者不會受到視覺刺激或動手指,而是故意地增加呼吸的深度四分鐘(從第二分鐘開始到第五分鐘結束)。深呼吸會減低血液中的二氧化碳,因而使腦中的血流降低(二氧化碳會擴張血管)。因此,這個掃瞄將顯示血流的改變對腦的不同區域血氧濃度變化信號的影響。
    deep breathing, no task: in this run, also seven minutes long, the subject did not receieve visual stimulation or move her hand. Instead, she deliberately increased the depth of her breathing for a four minute period during the scan (the second through fifth minutes). Deep breathing lowers the amount of carbon dioxide in the blood, which in turn lowers blood flow throughout the brain (CO2 is a vasodilator). This scan should therefore show us the effects of such a change in blood flow on the BOLD signal in different parts of the brain.

  • 視覺刺激/手指運動,加上深呼吸:在這個掃瞄中,我們結合前兩個掃瞄的事件,也就是要受試者深呼吸四分鐘,並在這段過度換氣的過程中,接受視覺刺激並進行手指運動。其目的在顯示呼吸造成的影響會如何跟視覺與運動作業的反應結合。
    visual stimulation/hand movement plus deep breathing: In this run we combined the events in the two previous scans. That is, the subject breathed more deeply for four minutes and in the middle of this period of hyperventillation she underwent visual stimulation and performed the hand movement task. The purpose of this run is to see how breathing-related effects combine with the responses to visual and motor tasks.


實驗3:運用生理數據強化功能性磁振造影信號偵測
Lab 3: Improving fMRI Signal Detection using Physiological Data

這個實驗將觀察兩種運用生理數據來強化功能性磁振造影信號偵測的辦法。
This Lab examines two ways that physiological data can be used to improve fMRI signal detection.

實驗概要
Lab Overview

本實驗的資料組織如下:
The organization of the data for this lab is as follows:

第一部份:心跳同步
Part I: Cardiac Gating

第二部份:集中掃瞄法
Part II: Clustered Volume Acquisition (CVA)

  • 結合集中掃瞄法與心跳同步
    Combining CVA and cardiac gating
  • 集中掃瞄法與時間取樣速度
    CVA and temporal sampling

心跳同步
Cardiac Gating

本實驗的第一部份著重在心跳同步上,這個技術運用受試者在掃瞄的過程中記錄的心電圖來提高功能性磁振造影信號的偵測。心跳同步可以用來突破對腦幹結構作功能性造影時的技術困難,此問題在於腦幹會受到心跳影響而產生脈動。心跳同步藉由:(1)將影像擷取跟受試者的心跳同步,並且(2) 補償修正影像信號強度因心跳率變化而導致的取像間距(TR)的改變(參考Guimaraes等人1998年的論文),因而克服了這個問題。
Part I of this Lab focuses on cardiac gating. This technique uses a subject's EKG recorded during an experiment to improve fMRI signal detection. Cardiac gating is used to overcome a technical difficulty associated with functionally imaging brainstem structures. This difficulty arises because there is considerable cardiac-related, pulsatile brainstem motion. Cardiac gating avoids this problem by (1) synchronizing image acquisitions to the subject's heart beat, then (2) correcting image signal strength to account for the variability in interimage interval (TR) that results from fluctuations in heart rate (Guimaraes et. al., 1998).

在這個實驗裡,我們將觀察聽覺系統中的組織來評估心跳同步的效果。聲音在腦幹的聽覺區中被廣泛地處理,而心跳同步對探討這些歷程非常重要。本實驗將把注意力放在兩個特別的聽覺組織上,其中之一是下丘(inferior colliculus)這個腦幹組織,它是下層與上層腦中樞神經投射匯集的主要地點;另一個組織則是赫氏回(Heschl's gyrus),這是主要聽覺皮層所在。
In this Lab, the effects of cardiac gating are examined for structures in the auditory system. Sounds are processed extensively within auditory brainstem structures, and cardiac gating is important for investigating this processing. The Lab will focus on two particular auditory structures. One is the inferior colliculus. This brainstem structure is a major site of converging projections from both lower and higher brain centers. The second structure is Heschl's gyrus, the site of primary auditory cortex.

集中掃瞄法
Clustered Volume Acquisition (CVA)

本實驗的第二部份,要探討減低造影儀噪音的技術對聽覺活化的影響,這個技術稱為集中掃瞄法。跟心跳同步不同的是,它不需要在實驗過程中記錄生理數據來提升信號的偵測,不過它是直接依據生理數據的,特別是關於功能性磁振造影信號反應的時間特性(即:反應潛伏時間、持續時間)的一般資訊。
Part II of this Lab examines a technique for minimizing the effects of scanner acoustic noise on auditory activation. This technique is called clustered volume acquisition (CVA). Unlike cardiac gating, CVA does not use physiological data recorded during each experiment to improve signal detection. However, the technique is based directly on physiological data, specifically general information concerning the temporal characteristics of fMRI responses (i.e., response latency, duration).

造影環境中有兩類主要的噪音(參考Ravicz等人2000年的論文,及Ravicz 與Melcher在2001年的論文),其一是由磁鐵的冷卻泵所產生的持續性噪音,另一個更吵的則是間斷的噪音,它是由造影的梯度線圈每次在造影時產生的,這個噪音會對使用聲音刺激的研究造成困擾,因為它會(1) 遮蔽掉刺激,並(2)導致跟刺激無關的腦活動(這個跟噪音有關的腦活動會壓抑真正要的聲音刺激產生的功能性磁振造影信號變化)。
There are two main types of acoustic noise in the imaging environment (Ravicz et al., 2000 ;Ravicz and Melcher, 2001). One is an on-going noise produced by the pumping of coolant to the magnet. The second, more intense noise is intermittent. It is produced by the scanner gradient coils each time an image is acquired. The noise can pose difficulties for studies using sound stimuli by (1) masking the stimuli, and (2) inducing brain activity that is not related to the stimuli (this noise-related brain activity acts to suppress the fMRI signal changes produced by the intended sound stimuli).

集中掃瞄法可以減低由梯度線圈造成的擾人噪音所帶來的影響,它藉由把要掃瞄的切面集中在短時間內取得,使得到下一組掃瞄之間有一段安靜的時間(參考Edmister等人1999年及Hall等人1999年的論文)。利用這個典範,在這段安靜時間內呈現聲音刺激,就能免除梯度線圈噪音的遮蔽效果,此外,再透過:(1)讓取一組影像的時間比第一張影像的噪音產生的功能性信號的發起時間(onset time)來得短,以及(2)讓兩組影像的時間間隔(TR)比一組影像的噪音所產生的功能性信號反應期間來得長,就能避免梯度線圈噪音對聽覺活化反應的抑制效果。
CVA provides a way to reduce the effects of the most problematic noise, namely the noise produced by the gradient coils. CVA involves imaging a volume of slices in a "cluster" and leaving a quiet interval between clusters (Edmister et. al., 1999; Hall et. al., 1999). With this paradigm, the masking effects of the gradient noise can be avoided by presenting sound stimuli during the quiet interval. In addition, the suppressive effect of the gradient noise on auditory activation can be avoided by (1) making the duration of the image cluster shorter than the onset time of the fMRI response to the first image in the cluster, and (2) making the time between clusters (TR) longer than the fMRI response to a cluster.

用集中掃瞄法來偵測聽覺皮層活化的優點會在課堂上解釋,在本實驗中,還將會結合集中掃瞄法與心跳同步,來探討怎麼把這些優點運用到下皮層組織的造影上。此外,當集中掃瞄法使用很長的TR時(如:8秒),影像信號是以比多數功能性磁振造影研究更慢的速度在取樣,這個較低的時間解析度對實驗設計的意涵也將在本實驗中探討。
The benefits of CVA for detecting activation in auditory cortex were illustrated in lecture. In this Lab, you will examine how these benefits can be extended to subcortical structures by combining CVA with cardiac gating. When CVA is used with a long TR (e.g., 8 sec), image signals are sampled far less frequently than in most fMRI studies. The implications of this lower temporal resolution for experimental design will also be examined in this Lab.

第IIa部分:結合集中掃瞄法與心跳同步
Part IIa: Combining CVA with Cardiac Gating

動物實驗已顯示,從腦幹到皮層的聲音表現在神經興奮型態上會有很大的不同。假設你想要用功能性磁振造影在人身上觀察這些改變,也就是要用多切面造影同時掃瞄包括上顳葉及下皮層聽覺區在內的許多聽覺皮質區的活化。這可以透過結合心跳同步(以偵測腦幹的活化)與集中掃瞄法(以避免梯度線圈噪音的干擾)來達到。這部分的實驗將會探討結合這兩種技術時的問題。
Animal work has shown that the representation of sound in neural firing patterns changes considerably from brainstem to cortex. Suppose you want to examine these changes in humans using fMRI. In other words, you want to sample activation in the various auditory cortical areas that cover the superior temporal lobe (i.e. use multislice imaging) and, simultaneously, detect activation in subcortical auditory structures. This can be accomplished by combining cardiac gating (to optimize detection of brainstem activation) with CVA (to avoid the contaminating effects of the gradient noise). This part of the Lab considers issues related to combining these two techniques.

第IIb部分:集中掃瞄法與時間取樣
Part IIb: CVA and temporal sampling

雖然造影儀的噪音干擾可以用集中掃瞄法加上長TR(如:大於8秒)來減低,但是要付出時間解析度降低的代價。這部分的實驗會:(一)顯示低時間解析度的潛在問題;(二)探討運用調控影像擷取與聲音刺激典範間的時序,來避免這個問題的方法。
While the contaminating effects of acoustic scanner noise can be reduced using CVA with a long TR (e.g., 8+ sec), the price is diminished temporal resolution. This part of the lab (a) illustrates a potential pitfall of this lower temporal resolution, and (b) examines ways this pitfall can be avoided by controlling the timing between image acquisitions and the auditory stimulation paradigm.

一開始,我們將會用較高的時間解析度(約2秒)來觀察兩種聲音在聽覺皮層活化隨時間的信號變化,接著思考這些信號波形在較低時間解析度取樣時可能的改變。這兩種聲音都是一連串重複的噪音音爆(noise burst,常用於聽覺神經生理及聽覺心理學的研究中),這種「噪音」像是收音機在沒調對電台頻道時的大氣噪音。其中一個聲音,音爆串以低頻率在變化(每秒2次),另一個則變化較快(每秒35次),每個音爆約25 ms長。對這種刺激的反應的詳細研究可參考Harms跟Melcher在2002年的論文。
To begin, you will examine the time course of activation in auditory cortex at high temporal resolution (~2 sec) for two example sounds. You will then consider the implications of sampling these time courses at a lower temporal resolution. The example sounds were trains of repeated noise bursts (a stimulus commonly used in auditory neurophysiologic and psychoacoustic investigations). The "noise" of each burst sounds like the static from a radio that is not tuned to a station. For one sound, bursts occurred in a train at a low rate (2/sec). For the other, the rate was high (35/sec). Each burst was ~25 ms long. A detailed examination of the responses to these stimuli can be found in Harms and Melcher, 2002.

實驗報告指引
Guidelines for Laboratory Report

實驗報告要包含對問題的答案。不要重複實驗手冊的內容,簡介也不要太長,整個報告不應超過四頁。在結尾的部分要用幾個句子總結你在實驗中學到的東西。
Your laboratory report should contain answers to the questions specified below. Do not repeat the lab instructions and avoid lengthy introductions. Your report should not exceed 4 pages. Conclude your report with a few sentences summarizing what you learned in the lab.

參考文獻
References

Guimaraes, et al.〈人類下皮層聽覺區活化之造影〉 《Human Brain Mapping》 6 (1998): 33-41
Guimaraes, et al. "Imaging Subcortical Auditory Activity in Humans." Human Brain Mapping 6 (1998): 33-41.

Hall, et al.〈以稀疏時間取樣進行聽覺功能性磁振造影〉 《Human Brain Mapping》 7 (1999): 213-223.
Hall, et al. "Sparse Temporal Sampling in Auditory fMRI." Human Brain Mapping 7 (1999): 213-223.

Edmister, et al.〈以集中掃瞄法改進聽覺皮層造影〉 7 (1999): 89-97.
Edmister, et al. "Improved Auditory Cortex Imaging Using Clustered Volume Acquisitions." 7 (1999): 89-97.

Harms, and Melcher.〈聲音重複率在人類聽覺路徑中的表徵:功能性磁振造影活化波形與幅度的表現〉 《J. Neurophysiol》. 88 (2002): 1433-1450.
Harms, and Melcher. "Sound Repetition Rate in the Human Auditory Pathway: Representations in the Waveshape and Amplitude of fMRI Activation." J. Neurophysiol. 88 (2002): 1433-1450.

Ravicz, et al.〈功能性磁振造影過程中的噪音〉 《J. Acoust. Soc. Am.》 108 (2000): 1-14.
Ravicz, et al. "Acoustic Noise During Functional Magnetic Resonance Imaging." J. Acoust. Soc. Am. 108 (2000): 1-14.

Ravicz, and Melcher.〈隔絕功能性磁振造影過程中的噪音對聽覺系統的影響:透過耳道、頭部與身體的噪音傳導之研究〉 109 (2001): 216-231.
Ravicz, and Melcher. "Isolating the Auditory System from Acoustic Noise During Functional Magnetic Resonance Imaging: Examination of Noise Conduction Through Ear Canal, Head, and Body." 109 (2001): 216-231.



實驗4:擴散張量影像實驗
Lab 4: Diffusion Tensor Imaging Lab

實驗4手冊與問題(PDF)
Lab 4 Manual & Questions (PDF)

*請注意:跟實驗有關的資料與檔案目前尚未提供
*Note that the data and files associated with the labs are not available at this time.

簡介
Introduction

近幾年來,擴散張量影像逐漸成為一個研究健康與疾病狀態下白質結構的利器。常見的應用包括測量白質結構的完整性、描繪白質纖維走向,以及追蹤白質路徑。
In recent years, diffusion tensor imaging (DTI) has emerged as a powerful method for investigating white matter architecture in health and disease. Some common applications include measuring the structural integrity of white matter, mapping white matter fiber orientation, and tracking white matter pathways.

雖然大部分的核磁共振影像方法得到的是單變量(即純量)的影像,如:T1或T2影像,但擴散張量影像所產生的是多變量(即張量)的影像,因而它帶來許多有趣的影像重建與視覺化的挑戰。所以,這個實驗的目的雖然是要讓大家瞭解擴散張量影像的重建與分析方法,但同時也希望能讓大家熟悉多變量資料的視覺化與分析方法。
While most MRI methods generate univariate (i.e., scalar) images, for example, T1 or T2 maps, DTI produces multivariate (i.e., tensor-valued) images. Hence, DTI poses a number of interesting image reconstruction and visualization challenges. Accordingly, while the specific objective of this lab is to familiarize you with DTI reconstruction and analysis, the more general goal is to acquaint you with multivariate data visualization and analysis.

關於本實驗的背景知識請參考:
For background reading for this lab please read:

Le Bihan, D., J. F. Mangin, C. Poupon, C. A. Clark, S. Pappata, N. Molko, and H. Chabriat.〈擴散張量影像:概念與應用>《J Magn Reson Imaging》 13, 4 (Apr. 2001): 534-546.
Le Bihan, D., J. F. Mangin, C. Poupon, C. A. Clark, S. Pappata, N. Molko, and H. Chabriat. "Diffusion Tensor Imaging: Concepts and Applications." J Magn Reson Imaging 13, 4 (Apr. 2001): 534-546.

此外,請先熟悉使用MATLAB中的相機工具(camera tool)來觀看三維圖像。
Also, please familiarize yourself with three-dimensional graphics navigation in MATLAB® using the camera toolbar.



實驗5:功能性磁振造影資料分析教學
Lab 5: fMRI Data Analysis Tutorial

實驗5:手冊與問題 (PDF)
Lab 5 Manual & Questions (PDF)

*請注意:跟實驗有關的資料與檔案目前尚未提供
*Note that the data and files associated with the labs are not available at this time.

簡介
Introduction

本實作練習是補功能性磁振造影資料統計分析課堂與指定閱讀的不足。
These laboratory exercises complement the lectures and assigned readings on statistical analysis of fMRI data.
本教學的目的在於:
The goals of this tutorial are to help you with the following:

  • 瞭解功能性磁振造影資料的時間與空間相關性。
    Understanding temporal and spatial correlation in fMRI data;
  • 瞭解如何建構功能性磁振造影資料的統計模式。
    Understanding how to construct a statistical model for fMRI data;
  • 辨認功能性磁振造影信號中的雜訊來源及其影響。
    Identifying sources of noise and their contribution to fMRI signals; and
  • 瞭解移動校正及空間濾波對功能性磁振造影資料統計分析結果的影響。
    Understanding the effects of motion correction and spatial filtering on the outcome of statistical analysis of fMRI data.

資料
Data

實驗資料是以西門子3T造影儀,以頭部線圈跟下列掃瞄參數取得:
The data was acquired on a a Siemens 3 T scanner using a head coil and the following acquisition parameters:

TR = 2 s
TE = 30 ms
偏折角= 90°
切面解析度 = 4mm x 4mm (視野256 mm,矩陣大小64x64)
180個時間點
21個切面,每個切面 為4mm厚,加上1mm間距(以交錯的切面次序取得)

TR = 2 s
TE = 30 ms
alpha = 90°
in-plane resolution = 4mm x 4mm (256 mm FOV on 64x64 matrix)
180 time points
21 slices, each 4mm thick with 1mm gap (acquired in interleaved order)

實驗典範
Paradigm

實驗將包含20個18秒長(9個TR)的時段(epoch),在每個時段裡,視覺圖案會在前兩秒(1個TR)中呈現,這個圖案是在灰底中呈現的閃爍環狀棋盤格,而在該時段的剩下時間裡(16秒,即8個TR)則只會顯示灰底及一個黑色的凝視點。
There were 20 epochs of 18 seconds (9 TRs) each. During each epoch, a visual pattern was shown during the first two seconds (1 TR). The pattern consisted of a flashing checkerboard annulus (ring) pattern against a gray background. For the rest of the epoch (16 seconds/8 TRs), only the gray background was present, along with a black dot for fixation.



實驗6:以磁振造影區分皮層與下皮層結構
Lab 6: Cortical and Subcortical Parcellation with MRI

實驗6:手冊與問題(PDF)
Lab 6 Manual & Questions (PDF)

*請注意:跟實驗有關的資料與檔案目前尚未提供
*Note that the data and files associated with the labs are not available at this time.

目的
Goals

這個實驗將探討如何利用不同對比權重的高解析度核磁共振解剖影像,來區分不同的腦解剖結構。
This Lab examines ways in which different brain anatomical structures can be classified based on the signal intensity of high spatial resolution anatomical MR images acquired with different contrast weightings.

實驗架構
Organization of the lab

  • 使用MATLAB程式載入一些影像(T1與質子密度圖)。
    You will run a MATLAB® program that loads some images (T1 and proton density maps).
  • 回答關於影像的問題。
    You will be asked questions about these images.
  • 要回答這些問題,將需要撰寫一些簡單的MATLAB函數來處理影像。
    To answer these questions you will have to process the images using simple MATLAB® functions that you will have to write for this purpose.



MATLAB® 是 The MathWorks, Inc.的註冊商標。

MATLAB® is a trademark of The MathWorks, Inc.




 
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