.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "generated/gallery/11-spin-echo/se_radial2D_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_11-spin-echo_se_radial2D_sequence.py: ===================== 2D radial spin echo ===================== A slice-selective excitation and 180-degree refocusing pulse form one spin echo, followed by a radial spoke through k-space centre. Spoilers suppress unwanted coherence before the next TR. TE controls T2 weighting and TR controls longitudinal recovery. Radial spin echo supports motion-robust structural imaging. .. GENERATED FROM PYTHON SOURCE LINES 12-32 .. GENERATED FROM PYTHON SOURCE LINES 33-38 Nyquist angular sampling ------------------------ ``ceil(pi / 2 * n)`` spokes over half a turn, which sample the outer radius at the Nyquist spacing. .. GENERATED FROM PYTHON SOURCE LINES 38-46 .. code-block:: Python import pypulseqpp as pp from pypulseqpp.sequences import se_radial2D_sequence baseline = se_radial2D_sequence(n=192, n_slices=1, te=None, 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 2114 blocks, 5.90 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/11-spin-echo/images/sphx_glr_se_radial2D_sequence_001.png :alt: se radial2D sequence :srcset: /generated/gallery/11-spin-echo/images/sphx_glr_se_radial2D_sequence_001.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 53-57 Sampling order -------------- Colour encodes spoke acquisition order. .. GENERATED FROM PYTHON SOURCE LINES 57-60 .. code-block:: Python pp.plot.plot_kspace(baseline, color_by="shot", plane="xy") .. image-sg:: /generated/gallery/11-spin-echo/images/sphx_glr_se_radial2D_sequence_002.png :alt: se radial2D sequence :srcset: /generated/gallery/11-spin-echo/images/sphx_glr_se_radial2D_sequence_002.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 61-66 Angular undersampling --------------------- Retaining one spoke angle in three reduces peripheral angular sampling; every acquired spoke still crosses the k-space origin. .. GENERATED FROM PYTHON SOURCE LINES 66-78 .. code-block:: Python alternative = se_radial2D_sequence(n=192, n_slices=1, ry=3, te=None, tr=None, n_dummy=0) .. rst-class:: sphx-glr-script-out .. code-block:: none blocks duration (s) acquisitions Nyquist 2114 5.90 302 ry = 3 707 1.97 101 .. GENERATED FROM PYTHON SOURCE LINES 79-81 .. code-block:: Python pp.plot.plot_kspace(alternative, color_by="shot", plane="xy") .. image-sg:: /generated/gallery/11-spin-echo/images/sphx_glr_se_radial2D_sequence_003.png :alt: se radial2D sequence :srcset: /generated/gallery/11-spin-echo/images/sphx_glr_se_radial2D_sequence_003.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 2.732 seconds) .. _sphx_glr_download_generated_gallery_11-spin-echo_se_radial2D_sequence.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: se_radial2D_sequence.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: se_radial2D_sequence.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: se_radial2D_sequence.zip ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_