How to get the masterVolumeNode from the dicom series

hello every teachers:
I used python code to load the ct dicom files, then i want to get the masterVolumeNode from the dicom file ,
the load dicom files as followes:

def loadCtData():
    dicomDataDir = "D:/xgx/newdicom"  
    ###"D:\301\15\443250"  "D:/301/15/443250"
    loadedNodeIDs = []  

    from DICOMLib import DICOMUtils
    with DICOMUtils.TemporaryDICOMDatabase() as db:
        DICOMUtils.importDicom(dicomDataDir, db)
        patientUIDs = db.patients()
        for patientUID in patientUIDs:

You can get the referenced volume node from the segmentation via the referenceImageGeometryRef node reference. For example:

segmentationNode = getNode('Segmentation')
volumeNode = segmentationNode.GetNodeReference('referenceImageGeometryRef')

ok, i wlii try, thanks