[Mristudio-users] 回复： re： MriView3D application close

Sat Apr 18 11:28:48 EDT 2009

Please try Siemens “Mosaic” format.

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From: mristudio-users-bounces at mristudio.org [mailto:mristudio-users-bounces at mristudio.org] On Behalf Of jinsong tang
Sent: Saturday, April 18, 2009 8:05 AM
To: DTI Studio, ROI Editor, Landmarker Questions/Support
Subject: [Mristudio-users] 回复： re： MriView3D application close

Dear Susumu,

Thanks for your comments. another question. How to use DTIstudio deal with 3T seimens DTI data, they are saved in volumes by volumes, not slice by sclice

Best,

Jinsong

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发件人： susumu <susumu at mri.jhu.edu>
收件人： "DTI Studio, ROI Editor, Landmarker Questions/Support" <mristudio-users at mristudio.org>
已发送： 2009/4/17(周五), 下午3:41:48
主题： Re: [Mristudio-users] re： MriView3D application close

Hi Jinsong,

1) I usually use 2.5 x 2.5 x 2.5 mm for 1.5 T. About 60 DWI (with 12-orientation, 5 repeated NEX=1 (preferable) or NEX=5) should give decent SNR, which should take about 7-8 min. With 3T, 30 DWI should look good (3.5-4 min). 

For this protocol, 240x240 mm / 96x96 will do.

2) We also use 2.2 x 2.2 x 2.2 mm for 3T with 60 DWI (8 min).

3) Your protocol is 240/128 = 1.9 x 1.9. With 3 mm slice, this is about the same as 2.2x2.2x2.2. So, I think 12-orientation x 5 (60DWI) should provide decent SNR. However, because you are using longer echo trains, you have longer echo time (= SNR loss), more distortion, and more blurring (less true resolution due to T2* decay during the long echo). I prefer 96x96 with that reason.

4) I prefer NEX = 1 x 5 repetition rather than NEX = 5, but I believe recent Siemens scanners have an option for “no average” even if you use NEX = 5 (all 5 NEX data are saved separately).

5) I use shortest TR and your TR seems right.

Susumu 

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From: mristudio-users-bounces at mristudio.org [mailto:mristudio-users-bounces at mristudio.org] On Behalf Of jinsong tang
Sent: Wednesday, April 15, 2009 12:06 AM
To: DTI Studio, ROI Editor, Landmarker Questions/Support
Subject: [Mristudio-users] re： MriView3D application close

Dear Susumu,

This is my protocol of DTI  and 3D scaning at SIEMENS 3T,  Would you please review it and give me some suggestions.

Thanks,

Jinsong

DTI:

Axial

FOV= 240×240mm

Slice thickness= 3mm

Slice number=45

Gap=0mm

Matrix=128×128

NEX=5  or  1

TR=6046ms  ？

TE=93 

Diffusion directiuon =12

b=1000, b0=0.

3D 

TR= 2000ms

TE=2.6ms

FOV=240×240mm

Slice thickness=1mm

Gap=0mm

Slices=176

Matrix=256×256

Slice orientation= sagittal 

Flip angle=15º

NEX=1

  _____  

发件人： susumu <susumu at mri.jhu.edu>
收件人： "DTI Studio, ROI Editor, Landmarker Questions/Support" <mristudio-users at mristudio.org>
已发送： 2009/4/9(周四), 下午11:04:09
主题： Re: [Mristudio-users] MriView3D application close

Hi Hugh,

When you got this error, please suspect one of the following two reasons;

1) Memory shortage:

Even if you have many GB of memories, 32-bit Windows system can allocate only 1 - 1.5 GB to each program. To check if you have the memory problem, please restrict the slices to be calculated. In the initial data parameter window, there is a section called "Slices to be processed". Here you can specify only a portion of slices to be processed. Please limit the slices to, for example, 0-9 and see how it goes. If you can calculate tensors without errors, then you have the memory problem. The solution is; a) upgrade to the 64-bit system or b) devide the calculation to 2 batches (e.g. slice 0-29 for the first batch and 30-59 for the second batch), calculate all maps (e.g. FA), and later combine them.

2) Mismatch between the gradient table and the number of images:

For example, if you specify 12-orientation table and 30 volume images, then you get the error. After loading the data and before you go to the Dti Map tab, make sure that you have 1 b0 + 64 DWIs in the pull-down menu in the right column of the Image tab. If you have the correct number of the images, then you might have an error in your gradient table. Small mistakes such as missing "," are often difficult to detect. The best way is; a) load the data using DtiMapping under the "File" button on the top left, b) close the window, c) open the image paremater window again by clicking "DtiMapping" in the "File" button again, d) the window still remembers the gradient table you entered last time. This remembered window tells how DtiStudio interpreted your gradient table. If there is any syntax errors, you may find them much easier. For example, if you enter, "4: 1 0.5 0", instead of "4: 1, 0.5, 0", then you would find, "4: 1, 0, 0".

If any of these do not solve the issue, please let us know.

Susumu

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From: mristudio-users-bounces at mristudio.org [mailto:mristudio-users-bounces at mristudio.org] On Behalf Of Hugh Wang
Sent: Wednesday, April 08, 2009 6:30 PM
To: mristudio-users at mristudio.org
Subject: [Mristudio-users] MriView3D application close

Hi, 

I was using the dtistudio (ver. 2.4)  to look at the Siemens DICOM diffusion images (1baseline,64 gradients). After successfully loading the images, I click the "dti map" option at lower right corner. Whatever calculation I choose, it always gives me an error: 

"MriView3D MFC Application has encountered a problem and needs to close.  We are sorry for the inconvenience."

I tried several PCs, and the problem keeped the same. I would appreciate that if there's anyone having any idea on how to solve it. Thanks.

Best,
Hugh

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