Hi, all~~ I was processing PET-PiB data with SPM. After importing many ***.dcm file, there are 4 *.img files for each scanning, like this ***-000001.img ***-000036.img ***-000071.img ***-000106.img But the "Coregister" and "Normalise" option only permit one source image... Shall I process these 4 *.dcm files one by one (if so, how to combine these images together later, since I want a single *.mat data at last), or there are other methods ? Any suggestion helps, thanks in advance =] Best Regards, Jing Li Department of Control Science and Engineering, Chu Kochen Honors College Zhejiang University Tel (+86)1885-828-0435 / (+1) 617-335-0412