question about dicomwrite function and converting

Hi all, I use dicomwrite function to write a three dimensional matrix to a dicom file with MR image storage,and this is success.My syntax is as follows:

x=100*rand(63,53,46);

dicomwrite(reshape(x,[63,53,1,46]),'test.dcm','ObjectType','MR Image Storage');

But when I use SPM(Statistical Parametric Mapping) converting these dicom data to ananlyze data,I get a error:

"Cant find appropriate modality information"

Thank you

[Walter Roberson]

duplicates http://www.mathworks.co.uk/matlabcentral/answers/57425-question-about-dicomwrite-function