code: def isdicom(fn):
      '''True if the fn points to a DICOM image'''
      fn = str(fn)
      if fn.endswith('.dcm'):
          return True
      # Dicom signature from the dicom spec.
      with open(fn,'rb') as fh:
          fh.seek(0x80)
          return fh.read(4)==b'DICMf isdicom(fn):
      '''True if the fn points to a DICOM image'''
      fn = str(fn)
      if fn.endswith('.dcm'):
          return True
      # Dicom signature from the dicom spec.
      with open(fn,'rb') as fh:
          fh.seek(0x80)
          return fh.read(4)==b'DICM'
docs: True if the fn points to a DICOM image