The CTP ZipObject

The CTP ZipObject is a collection of files wrapped in a zip file. It is intended to encapsulate groups of related files, for instance several data files which are the results of analysis of clinical trial data. To carry information that allows applications to know how to relate a ZipObject to other data, each ZipObject must contain a manifest. A manifest is an XML text file named manifest.xml, located in the root of zip file's directory tree (e.g. with no path information).

The root element of a manifest can have any name. By convention, it is called manifest.

The root element has several attributes:

• uid is required. It defines a unique identifier for the ZipObject. The DICOM UID format is strongly suggested, but there is no technical requirement imposed by the ZipObject on the format.
• study-uid is required in clinical trial data submissions. It provides a reference to the study. This attribute links the ZipObject to other objects associated with the same study. If the ZipObject contains results obtained from the analysis of DICOM images from a specific study, the DICOM StudyInstanceUID must be used. If the ZipObject is not used as part of a clinical trial data submission, this attribute is optional.
• pt-id is optional. For ZipObjects which encapsulate data for a single patient, this identifier may be included.
• pt-name is optional. For ZipObjects which encapsulate data for a single patient, this attribute may be included.
• description is optional. It provides a free text description of the ZipObject.
• date is optional. It provides a date for the ZipObject. The date must be in the format specified by ISO 8601 (YYYY-MM-DD).
• version is optional. It provides a version reference for the manifest format. This could be used by software as an aid in interpreting its contents.
• type is optional. It can be used to distinguish between ZipObjects of different types. No enumerated values of the type attribute are defined.

The manifest root element has no required child elements. The intention is that each manifest contain whatever child elements are appropriate to describe the contents of the ZipObject and their relationships with each other as well as external objects, but there is no required standard format. It is expected that each application (e.g., each clinical trial or research project) will invent its own manifest consistent with the attributes defined above.

An example of a simple manifest is:

<manifest uid="1.2.3.4.5"
          study-uid="1.2.3.4.5.1"
          description="Analytical results" />

A more complex manifest might be:

<manifest uid="1.2.3.4.1"
          study-uid="1.2.3.4.5.1"
          pt-id="123"
          description="Analytical results"
          date="2006-11-06"
          version="1">
    <series uid="1.2.3.4.5.2">
        <instance uid="1.2.3.4.5.4"/>
        <instance uid="1.2.3.4.5.5"/>
        <instance uid="1.2.3.4.5.6"/>
        <instance uid="1.2.3.4.5.7"/>
    </series>
    <series uid="1.2.3.4.5.3">
        <instance uid="1.2.3.4.5.8"/>
        <instance uid="1.2.3.4.5.9"/>
    </series>
</manifest>