Objective This study presents the 3D MP-b-nSSFP sequence for multi-parametric mapping. Methods We evaluate several aspects of the 3D implementation, like the type of RF pulse (selective/non-selective), the readout duration, the undersampling pattern, and the acceleration factor. We use undersampled scans with subspace-constrained reconstruction and extended spiral readouts to achieve clinically acceptable scan times. The repeatability and accuracy of the <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10334_2025_1262_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">$T_1$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mn>1</mn> </msub> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10334_2025_1262_Article_IEq2.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">$T_2$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation> maps are compared with a reference technique in phantom and three volunteer scans. Results Compared with selective refocusing pulses, we observe lower bias with non-selective pulses, despite modeling the spatially varying effect of the pulses in the fitting process. <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10334_2025_1262_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">$T_1$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mn>1</mn> </msub> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10334_2025_1262_Article_IEq2.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">$T_2$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation> maps obtained from phantom scans were comparable to the nominal values and those from reference scans. <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10334_2025_1262_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">$T_1$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mn>1</mn> </msub> </math></EquationSource> </InlineEquation> values in vivo were underestimated compared to the reference scan. The maps with an acquisition matrix of <InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10334_2025_1262_Article_IEq6.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="107" /> </InlineMediaObject> <EquationSource Format="TEX">$256 \times 256 \times 44$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>256</mn> <mo>×</mo> <mn>256</mn> <mo>×</mo> <mn>44</mn> </mrow> </math></EquationSource> </InlineEquation> and resolution <InlineEquation ID="IEq7"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10334_2025_1262_Article_IEq7.gif" Format="GIF" Height="14" Rendition="HTML" Resolution="72" Type="Linedraw" Width="67" /> </InlineMediaObject> <EquationSource Format="TEX">$1 \times 1 \times 3$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mn>1</mn> <mo>×</mo> <mn>1</mn> <mo>×</mo> <mn>3</mn> </mrow> </math></EquationSource> </InlineEquation> <InlineEquation ID="IEq8"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10334_2025_1262_Article_IEq8.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="35" /> </InlineMediaObject> <EquationSource Format="TEX">$\text {mm}^3$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mtext>mm</mtext> <mn>3</mn> </msup> </math></EquationSource> </InlineEquation> were acquired in 11 min. Conclusion We show that 3D MP-b-nSSFP can be used for multi-parameter mapping within clinically acceptable scan time. Phantom scans show results in good agreement with reference scan results. However, the in vivo scan underestimated <InlineEquation ID="IEq9"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10334_2025_1262_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">$T_1$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mn>1</mn> </msub> </math></EquationSource> </InlineEquation>.

3D multi-phase balanced non-steady-state free precession acquisition for multi-parameter mapping

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2025年5月26日

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Riwaj Byanju,
Gyula Kotek,
Mika W. Vogel,
Stefan Klein,
Juan A. Hernandez-Tamames,
Dirk H. J. Poot

摘要

Objective

This study presents the 3D MP-b-nSSFP sequence for multi-parametric mapping.

Methods

We evaluate several aspects of the 3D implementation, like the type of RF pulse (selective/non-selective), the readout duration, the undersampling pattern, and the acceleration factor. We use undersampled scans with subspace-constrained reconstruction and extended spiral readouts to achieve clinically acceptable scan times. The repeatability and accuracy of the $T_1$ $T_{1}$ and $T_2$ $T_{2}$ maps are compared with a reference technique in phantom and three volunteer scans.

Results

Compared with selective refocusing pulses, we observe lower bias with non-selective pulses, despite modeling the spatially varying effect of the pulses in the fitting process. $T_1$ $T_{1}$ and $T_2$ $T_{2}$ maps obtained from phantom scans were comparable to the nominal values and those from reference scans. $T_1$ $T_{1}$ values in vivo were underestimated compared to the reference scan. The maps with an acquisition matrix of $256 \times 256 \times 44$ $256 \times 256 \times 44$ and resolution $1 \times 1 \times 3$ $1 \times 1 \times 3$ $\text {mm}^3$ ${mm}^{3}$ were acquired in 11 min.

Conclusion

We show that 3D MP-b-nSSFP can be used for multi-parameter mapping within clinically acceptable scan time. Phantom scans show results in good agreement with reference scan results. However, the in vivo scan underestimated $T_1$ $T_{1}$ .