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A pure Python package for reading and writing DICOM data

Project description

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pydicom is a pure Python package for working with DICOM files. It lets you read, modify and write DICOM data in an easy "pythonic" way.

As a pure Python package, pydicom can run anywhere Python runs without any other requirements, although if you're working with Pixel Data then we recommend you also install NumPy.

If you're looking for a Python library for DICOM networking then you might be interested in another of our projects: pynetdicom.


Using pip:

pip install pydicom

Using conda:

conda install -c conda-forge pydicom

For more information, including installation instructions for the development version, see the installation guide.


The pydicom user guide, tutorials, examples and API reference documentation is available for both the current release and the development version on GitHub Pages.

Pixel Data

Compressed and uncompressed Pixel Data is always available to be read, changed and written as bytes:

>>> from pydicom import dcmread
>>> from import get_testdata_file
>>> path = get_testdata_file("CT_small.dcm")
>>> ds = dcmread(path)
>>> type(ds.PixelData)
<class 'bytes'>
>>> len(ds.PixelData)
>>> ds.PixelData[:2]

If NumPy is installed, Pixel Data can be converted to an ndarray using the Dataset.pixel_array property:

>>> arr = ds.pixel_array
>>> arr.shape
(128, 128)
>>> arr
array([[175, 180, 166, ..., 203, 207, 216],
       [186, 183, 157, ..., 181, 190, 239],
       [184, 180, 171, ..., 152, 164, 235],
       [906, 910, 923, ..., 922, 929, 927],
       [914, 954, 938, ..., 942, 925, 905],
       [959, 955, 916, ..., 911, 904, 909]], dtype=int16)

Compressed Pixel Data


Converting JPEG compressed Pixel Data to an ndarray requires installing one or more additional Python libraries. For information on which libraries are required, see the pixel data handler documentation.

Compressing data into one of the JPEG formats is not currently supported.


Encoding and decoding RLE Pixel Data only requires NumPy, however it can be quite slow. You may want to consider installing one or more additional Python libraries to speed up the process.


More examples are available in the documentation.

Change a patient's ID

from pydicom import dcmread

ds = dcmread("/path/to/file.dcm")
# Edit the (0010,0020) 'Patient ID' element
ds.PatientID = "12345678"

Display the Pixel Data

With NumPy and matplotlib

import matplotlib.pyplot as plt
from pydicom import dcmread
from import get_testdata_file

# The path to a pydicom test dataset
path = get_testdata_file("CT_small.dcm")
ds = dcmread(path)
# `arr` is a numpy.ndarray
arr = ds.pixel_array

plt.imshow(arr, cmap="gray")


To contribute to pydicom, read our contribution guide.

To contribute an example or extension of pydicom that doesn't belong with the core software, see our contribution repository: contrib-pydicom.

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