.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "generated/gallery/11-spin-echo/se2D_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_se2D_sequence.py: ======================== 2D Cartesian spin echo ======================== A slice-selective excitation and 180-degree refocusing pulse form one spin echo, followed by a Cartesian readout. Spoilers suppress unwanted coherence before the next TR. TE controls T2 weighting and TR controls longitudinal recovery. Spin echo is used for conventional T1-, T2-, and proton-density-weighted structural imaging. .. GENERATED FROM PYTHON SOURCE LINES 12-32 .. GENERATED FROM PYTHON SOURCE LINES 33-38 Fully sampled acquisition ------------------------- Every phase-encode line of one slice is acquired, at the minimum echo time permitted by the RF pulse and readout durations. .. GENERATED FROM PYTHON SOURCE LINES 38-49 .. code-block:: Python import pypulseqpp as pp from pypulseqpp.sequences import se2D_sequence baseline = se2D_sequence(n_x=192, n_y=192, n_slices=1, te=None, tr=None, n_dummy=0) print(f"{baseline.num_blocks} blocks, {baseline.duration()[0]:.2f} s") print( f"TE {baseline.get_definition('TE')[0] * 1e3:.2f} ms, " f"TR {baseline.get_definition('TR')[0] * 1e3:.2f} ms" ) .. rst-class:: sphx-glr-script-out .. code-block:: none 1536 blocks, 3.59 s TE 13.16 ms, TR 18.68 ms .. GENERATED FROM PYTHON SOURCE LINES 50-52 Sequence diagram ---------------- .. GENERATED FROM PYTHON SOURCE LINES 52-55 .. code-block:: Python baseline.paper_plot() .. image-sg:: /generated/gallery/11-spin-echo/images/sphx_glr_se2D_sequence_001.png :alt: se2D sequence :srcset: /generated/gallery/11-spin-echo/images/sphx_glr_se2D_sequence_001.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 56-60 Sampling order -------------- Colour encodes phase-encode line acquisition order. .. GENERATED FROM PYTHON SOURCE LINES 60-63 .. code-block:: Python pp.plot.plot_kspace(baseline, color_by="order", plane="xy", show_trajectory=False) .. image-sg:: /generated/gallery/11-spin-echo/images/sphx_glr_se2D_sequence_002.png :alt: se2D sequence :srcset: /generated/gallery/11-spin-echo/images/sphx_glr_se2D_sequence_002.png :class: sphx-glr-single-img .. GENERATED FROM PYTHON SOURCE LINES 64-70 Partial Fourier --------------- ``partial_fourier_y`` omits high-spatial-frequency lines on one side of k-space. Partial-Fourier reconstruction uses conjugate symmetry and requires a phase estimate; the reduced acquisition time is accompanied by an SNR penalty. .. GENERATED FROM PYTHON SOURCE LINES 70-84 .. code-block:: Python alternative = se2D_sequence( n_x=192, n_y=192, n_slices=1, partial_fourier_y=0.75, te=None, tr=None, n_dummy=0 ) .. rst-class:: sphx-glr-script-out .. code-block:: none blocks duration (s) acquisitions full 1536 3.59 192 6/8 along y 1152 2.69 144 .. GENERATED FROM PYTHON SOURCE LINES 85-87 .. code-block:: Python pp.plot.plot_kspace(alternative, color_by="order", plane="xy", show_trajectory=False) .. image-sg:: /generated/gallery/11-spin-echo/images/sphx_glr_se2D_sequence_003.png :alt: se2D sequence :srcset: /generated/gallery/11-spin-echo/images/sphx_glr_se2D_sequence_003.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 2.294 seconds) .. _sphx_glr_download_generated_gallery_11-spin-echo_se2D_sequence.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: se2D_sequence.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: se2D_sequence.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: se2D_sequence.zip ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_