.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "generated/gallery/10-gradient-echo/gre_multiecho3D_sequence.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code. .. rst-class:: sphx-glr-example-title .. _sphx_glr_generated_gallery_10-gradient-echo_gre_multiecho3D_sequence.py: ======================================= 3D Cartesian multi-echo gradient echo ======================================= A slab-selective spoiled excitation is followed by several gradient echoes of one Cartesian ``(line, partition)`` view. Gradient and RF spoiling suppress residual transverse coherence between repetitions. The multiple echo times sample T2* decay; TR and flip angle determine the T1 weighting. Applications include high-resolution structural imaging, R2* mapping, and QSM. .. GENERATED FROM PYTHON SOURCE LINES 12-32 .. GENERATED FROM PYTHON SOURCE LINES 33-38 Fully sampled acquisition ------------------------- Four echoes per excitation, over every ``(line, partition)`` view inside the ellipse inscribed in the phase-encode plane. .. GENERATED FROM PYTHON SOURCE LINES 38-48 .. code-block:: Python import pypulseqpp as pp from pypulseqpp.sequences import gre_multiecho3D_sequence baseline = gre_multiecho3D_sequence( n_x=160, n_y=160, n_z=32, n_echoes=4, tr=None, n_dummy=0 ) print(f"{baseline.num_blocks} blocks, {baseline.duration()[0]:.2f} s") .. rst-class:: sphx-glr-script-out .. code-block:: none 39950 blocks, 52.89 s .. GENERATED FROM PYTHON SOURCE LINES 49-51 Sequence diagram ---------------- .. GENERATED FROM PYTHON SOURCE LINES 51-54 .. code-block:: Python baseline.paper_plot() .. image-sg:: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_multiecho3D_sequence_001.png :alt: gre multiecho3D sequence :srcset: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_multiecho3D_sequence_001.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 55-59 Sampling order -------------- Colour encodes acquisition order in the phase-encode plane. .. GENERATED FROM PYTHON SOURCE LINES 59-62 .. code-block:: Python pp.plot.plot_kspace(baseline, color_by="order", plane="yz", show_trajectory=False) .. image-sg:: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_multiecho3D_sequence_002.png :alt: gre multiecho3D sequence :srcset: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_multiecho3D_sequence_002.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 63-68 Acceleration on both encoded axes --------------------------------- Subsampling both phase-encode axes reduces the number of repetitions. The complete echo train remains within each retained repetition. .. GENERATED FROM PYTHON SOURCE LINES 68-82 .. code-block:: Python alternative = gre_multiecho3D_sequence( n_x=160, n_y=160, n_z=32, n_echoes=4, ry=2, rz=2, tr=None, n_dummy=0 ) .. rst-class:: sphx-glr-script-out .. code-block:: none blocks duration (s) acquisitions full 39950 52.89 15980 2 x 2 12790 16.93 5116 .. GENERATED FROM PYTHON SOURCE LINES 83-85 .. code-block:: Python pp.plot.plot_kspace(alternative, color_by="order", plane="yz", show_trajectory=False) .. image-sg:: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_multiecho3D_sequence_003.png :alt: gre multiecho3D sequence :srcset: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_multiecho3D_sequence_003.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-timing **Total running time of the script:** (2 minutes 57.028 seconds) .. _sphx_glr_download_generated_gallery_10-gradient-echo_gre_multiecho3D_sequence.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: gre_multiecho3D_sequence.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: gre_multiecho3D_sequence.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: gre_multiecho3D_sequence.zip ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_