.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "generated/gallery/10-gradient-echo/gre3D_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_gre3D_sequence.py: ============================ 3D Cartesian gradient echo ============================ A 3D spoiled gradient-echo (SPGR) acquisition applies a low-flip-angle slab excitation before one Cartesian ``(line, partition)`` readout per TR. Gradient spoiling and quadratic RF/receiver phase cycling suppress coherent residual transverse magnetisation. TR, flip angle, and TE determine the T1 and T2* weighting. This sequence is used for high-resolution T1-weighted structural imaging. .. GENERATED FROM PYTHON SOURCE LINES 13-33 .. GENERATED FROM PYTHON SOURCE LINES 34-39 Fully sampled acquisition ------------------------- Every ``(line, partition)`` view inside the ellipse inscribed in the phase-encode plane is acquired. .. GENERATED FROM PYTHON SOURCE LINES 39-47 .. code-block:: Python import pypulseqpp as pp from pypulseqpp.sequences import gre3D_sequence baseline = gre3D_sequence(n_x=160, n_y=160, n_z=32, te=None, tr=None, n_dummy=0) print(f"{baseline.num_blocks} blocks, {baseline.duration()[0]:.2f} s") print(f"TR {baseline.get_definition('TR')[0] * 1e3:.2f} ms") .. rst-class:: sphx-glr-script-out .. code-block:: none 15980 blocks, 26.77 s TR 6.70 ms .. GENERATED FROM PYTHON SOURCE LINES 48-50 Sequence diagram ---------------- .. GENERATED FROM PYTHON SOURCE LINES 50-53 .. code-block:: Python baseline.paper_plot() .. image-sg:: /generated/gallery/10-gradient-echo/images/sphx_glr_gre3D_sequence_001.png :alt: gre3D sequence :srcset: /generated/gallery/10-gradient-echo/images/sphx_glr_gre3D_sequence_001.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 54-59 Sampling order -------------- Colour encodes acquisition order in the phase-encode plane. All lines of one partition are acquired before the next partition. .. 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_gre3D_sequence_002.png :alt: gre3D sequence :srcset: /generated/gallery/10-gradient-echo/images/sphx_glr_gre3D_sequence_002.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 63-70 Acceleration on both encoded axes --------------------------------- ``ry`` and ``rz`` subsample the line and partition axes independently. With ``ry=rz=2``, the phase-encode plane outside the central calibration region is acquired in approximately one quarter of the repetitions; the calibration region remains fully sampled. .. GENERATED FROM PYTHON SOURCE LINES 70-84 .. code-block:: Python alternative = gre3D_sequence( n_x=160, n_y=160, n_z=32, ry=2, rz=2, te=None, tr=None, n_dummy=0 ) .. rst-class:: sphx-glr-script-out .. code-block:: none blocks duration (s) acquisitions full 15980 26.77 3995 2 x 2 5116 8.57 1279 .. GENERATED FROM PYTHON SOURCE LINES 85-87 .. 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_gre3D_sequence_003.png :alt: gre3D sequence :srcset: /generated/gallery/10-gradient-echo/images/sphx_glr_gre3D_sequence_003.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 23.197 seconds) .. _sphx_glr_download_generated_gallery_10-gradient-echo_gre3D_sequence.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: gre3D_sequence.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: gre3D_sequence.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: gre3D_sequence.zip ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_