.. 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_stack_of_stars3D_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_stack_of_stars3D_sequence.py: ================================= 3D stack-of-stars gradient echo ================================= A slab-selective spoiled excitation is followed by one radial spoke with Cartesian partition encoding. Gradient and RF spoiling suppress residual transverse coherence between repetitions. TR and flip angle primarily determine T1 weighting. Stack-of-stars SPGR is used for motion-robust 3D structural and dynamic imaging. .. GENERATED FROM PYTHON SOURCE LINES 12-32 .. GENERATED FROM PYTHON SOURCE LINES 33-38 Nyquist angular sampling ------------------------ The Nyquist set of spoke angles at every partition. With the default ``partition_angle_shift='none'``, every partition uses the same angles. .. GENERATED FROM PYTHON SOURCE LINES 38-46 .. code-block:: Python import pypulseqpp as pp from pypulseqpp.sequences import gre_stack_of_stars3D_sequence baseline = gre_stack_of_stars3D_sequence(n=96, n_z=8, 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 4832 blocks, 8.84 s .. GENERATED FROM PYTHON SOURCE LINES 47-49 Sequence diagram ---------------- .. GENERATED FROM PYTHON SOURCE LINES 49-52 .. code-block:: Python baseline.paper_plot() .. image-sg:: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_stack_of_stars3D_sequence_001.png :alt: gre stack of stars3D sequence :srcset: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_stack_of_stars3D_sequence_001.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 53-57 Sampling order -------------- The spokes of every partition, over the three k-space axes. .. GENERATED FROM PYTHON SOURCE LINES 57-60 .. code-block:: Python pp.plot.plot_kspace(baseline, color_by="shot") .. image-sg:: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_stack_of_stars3D_sequence_002.png :alt: gre stack of stars3D sequence :srcset: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_stack_of_stars3D_sequence_002.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 61-66 Angular undersampling --------------------- Retaining one spoke angle in four reduces the number of repetitions fourfold. Every acquired spoke samples the origin of its partition. .. GENERATED FROM PYTHON SOURCE LINES 66-78 .. code-block:: Python alternative = gre_stack_of_stars3D_sequence(n=96, n_z=8, ry=4, tr=None, n_dummy=0) .. rst-class:: sphx-glr-script-out .. code-block:: none blocks duration (s) acquisitions Nyquist 4832 8.84 1208 ry = 4 1216 2.23 304 .. GENERATED FROM PYTHON SOURCE LINES 79-81 .. code-block:: Python pp.plot.plot_kspace(alternative, color_by="shot") .. image-sg:: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_stack_of_stars3D_sequence_003.png :alt: gre stack of stars3D sequence :srcset: /generated/gallery/10-gradient-echo/images/sphx_glr_gre_stack_of_stars3D_sequence_003.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 5.327 seconds) .. _sphx_glr_download_generated_gallery_10-gradient-echo_gre_stack_of_stars3D_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_stack_of_stars3D_sequence.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: gre_stack_of_stars3D_sequence.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: gre_stack_of_stars3D_sequence.zip ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_