Le Bihan Denis, Iima Mami, Partridge Savannah C
NeuroSpin, Joliot Institute, Commissariat à l'Energie Atomique (CEA), Paris-Saclay University, Bât 145, CEA-Saclay Center, 91191, Gif-sur-Yvette, France.
Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Eur Radiol. 2025 Feb;35(2):733-741. doi: 10.1007/s00330-024-10973-4. Epub 2024 Aug 7.
Fat-signal suppression is essential for breast diffusion magnetic resonance imaging (or diffusion-weighted MRI, DWI) as the very low diffusion coefficient of fat tends to decrease absolute diffusion coefficient (ADC) values. Among several methods, the STIR (short-tau inversion recovery) method is a popular approach, but signal suppression/attenuation is not specific to fat contrary to other methods such as SPAIR (spectral adiabatic (or attenuated) inversion recovery). This article focuses on those two techniques to illustrate the importance of appropriate fat suppression in breast DWI, briefly presenting the pros and cons of both approaches.
We show here through simulation and data acquired in a dedicated breast DWI phantom made of vials with water and various concentrations of polyvinylpyrrolidone (PVP) how ADC values obtained with STIR DWI may be biased toward tissue components with the longest T1 values: ADC values obtained with STIR fat suppression may be over/underestimated depending on the T1 and ADC profile within tissues. This bias is also illustrated in two clinical examples.
Fat-specific methods should be preferred over STIR for fat-signal suppression in breast DWI, such as SPAIR which also provides a higher sensitivity than STIR for lesion detection. One should remain aware, however, that efficient fat-signal suppression with SPAIR requires good B0 shimming to avoid ADC underestimation from residual fat contamination.
The spectral adiabatic (or attenuated) inversion recovery (SPAIR) method should be preferred over short-tau inversion recovery (STIR) for fat suppression in breast DWI.
Fat-signal suppression is essential for breast DWI; the SPAIR method is recommended. Short-tau inversion recovery (STIR) is not specific to fat; as a result, SNR is decreased and ADC values may be over- or underestimated. The STIR fat-suppression method must not be used after the injection of gadolinium-based contrast agents.
脂肪信号抑制对于乳腺扩散磁共振成像（或扩散加权磁共振成像，DWI）至关重要，因为脂肪极低的扩散系数往往会降低绝对扩散系数（ADC）值。在多种方法中，短反转恢复（STIR）法是一种常用方法，但与其他方法如频谱绝热（或衰减）反转恢复（SPAIR）不同，其信号抑制/衰减并非脂肪特异性。本文聚焦于这两种技术，以阐明乳腺DWI中适当脂肪抑制的重要性，并简要介绍两种方法的优缺点。
我们通过模拟以及在由装有水和不同浓度聚乙烯吡咯烷酮（PVP）的小瓶制成的专用乳腺DWI体模中获取的数据表明，STIR DWI获得的ADC值可能会偏向具有最长T1值的组织成分：根据组织内的T1和ADC分布情况，STIR脂肪抑制获得的ADC值可能被高估或低估。两个临床实例也说明了这种偏差。
在乳腺DWI的脂肪信号抑制方面，应优先选择脂肪特异性方法而非STIR法，如SPAIR法，其在病变检测方面也比STIR法具有更高的灵敏度。然而，应注意的是，使用SPAIR进行有效的脂肪信号抑制需要良好的B0匀场，以避免因残留脂肪污染导致ADC值被低估。
在乳腺DWI的脂肪抑制方面，应优先选择频谱绝热（或衰减）反转恢复（SPAIR）法而非短反转恢复（STIR）法。
脂肪信号抑制对于乳腺DWI至关重要；推荐使用SPAIR法。短反转恢复（STIR）法并非脂肪特异性；因此，信噪比降低，ADC值可能被高估或低估。注射钆基造影剂后不得使用STIR脂肪抑制法。
