# how to determine the pre-contrast and post-contrast through series time, acquisition time and content time in DCE-MRI dicom images
**URL:** https://discourse.vtk.org/t/how-to-determine-the-pre-contrast-and-post-contrast-through-series-time-acquisition-time-and-content-time-in-dce-mri-dicom-images/11661
**Category:** Support
**Created:** [June 10, 2023, 7:36pm UTC](https://discourse.vtk.org/t/how-to-determine-the-pre-contrast-and-post-contrast-through-series-time-acquisition-time-and-content-time-in-dce-mri-dicom-images/11661 "2023-06-10T19:36:47Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Ian\_Ben](https://discourse.vtk.org/u/Ian_Ben)
#### Post date: [June 10, 2023, 7:36pm UTC](https://discourse.vtk.org/t/how-to-determine-the-pre-contrast-and-post-contrast-through-series-time-acquisition-time-and-content-time-in-dce-mri-dicom-images/11661/1 "2023-06-10T19:36:47Z")
I was studying the DCE-MRI image on [Multi-center breast DCE-MRI data and segmentations from patients in the I-SPY 1/ACRIN 6657 trials (ISPY1) - The Cancer Imaging Archive (TCIA) Public Access - Cancer Imaging Archive Wiki](https://wiki.cancerimagingarchive.net/pages/viewpage.action?pageId=20643859)
It seems that they have pre-contrast, early post-contrast, and late post-contrast images, all of which are stored in the same DICOM series or multiple folders. However, I cannot determine which image is pre-contrast and which ones are post-contrast. In the DICOM tags, I found four time-related tags: study time, series time, acquisition time, and content time. I assume that the series time indicates the time when the pre-contrast image was collected. So, how can I determine which series belongs to pre-contrast and which series belongs to post-contrast using these time tags?
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### Author:  [@Stephen\_Aylward](https://discourse.vtk.org/u/Stephen_Aylward)
#### Post date: [June 10, 2023, 9:49pm UTC](https://discourse.vtk.org/t/how-to-determine-the-pre-contrast-and-post-contrast-through-series-time-acquisition-time-and-content-time-in-dce-mri-dicom-images/11661/2 "2023-06-10T21:49:19Z")
Determining this info is not always straightforward, and for older DICOM data (the data in the ISPY1 study is from 1980s) it can be non-standard. The TCIA does a great job of including supporting documentation. The link you sent has a link to the [Study Protocol](https://wiki.cancerimagingarchive.net/download/attachments/20643859/ACRIN%206657_protocol.pdf?version=1&modificationDate=1676738571823&api=v2) and it states that
“multiple quantitative parameters are extracted for estimation of
tumor volume and parameters related to contrast kinetics: initial percent
enhancement, PE = (S1-S0)/S0, and signal enhancement ratio (SER)=(S1-S0)/(S2-
S0), where S0, S1 and S2 are the pre-contrast, first post-contrast and second-post
contrast signal intensities of the three time-point data acquisition.27”
Looking through the dicom data, for each patient there is DICOM series labeled
Dynamic-3dfgre
It contains all three time points, in sequence. It has 180 time-sequential slices representing 3 passes over the breast. These are the S0, S1, and S2 images described in the study. You can view the data using this [link](https://www.cancerimagingarchive.net/viewer/?study=1.3.6.1.4.1.14519.5.2.1.7695.1700.162588073261248159118785473116&series=1.3.6.1.4.1.14519.5.2.1.7695.1700.334491271566855314830260417024&token=094a51b8-e687-4647-8d17-baf1760fe05d).
There are then two secondary/derived series:
Dynamic-3dfgre:SER
and
Dynamic-3dfgre: PE1
These were computed as defined in the study protocol.
I haven’t verified, but the acquisition time for each of the DICOM objects (slices) in the Dynamic-3dfgre series should allow you to differentiate S0 from S1 from S2.
Hope that helps.
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### Author:  [@Ian\_Ben](https://discourse.vtk.org/u/Ian_Ben)
#### Post date: [June 11, 2023, 7:09am UTC](https://discourse.vtk.org/t/how-to-determine-the-pre-contrast-and-post-contrast-through-series-time-acquisition-time-and-content-time-in-dce-mri-dicom-images/11661/3 "2023-06-11T07:09:46Z")
Great. Though some error exists, for instance, 095917 and 095918 for the acquisition time of one pre-contrast series. But Seems like the acquisition time is the only information to differentiate this. Cannot find other related tags.Thank you so much for your help.