Dwyer A J, Frank J A, Sank V J, Reinig J W, Hickey A M, Doppman J L
Department of Radiology, Warren G. Magnuson Clinical Center, Bethesda, Md 20892.
Radiology. 1988 Sep;168(3):827-36. doi: 10.1148/radiology.168.3.3406412.
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy.
反转恢复（IR）通常被认为是一种能够产生T1加权图像且能出色显示正常解剖结构的脉冲序列，它用途广泛：零点和峰值时间为IR的特性及其产生T1加权和T2加权图像的能力提供了有用且简洁的总结。缩短反转时间（TI）并创建短TI反转恢复（STIR）脉冲序列，通过使延长的T1和T2对信号强度的影响相加，并使脂肪信号归零，提高了对恶性肿瘤和其他异常的敏感性。作者检查了300多名患有各种恶性肿瘤的患者，并将STIR图像与在0.5T下获得的T1加权和T2加权图像进行了比较。在43例病例中，计算了肿瘤、脂肪和肌肉之间的信号差与噪声比（SD/N）。一般来说，STIR图像显示肿瘤在模糊但可辨别的解剖细节背景下为明显的高强度区域。STIR序列在肿瘤与脂肪（SD/N = 18.1）和肿瘤与肌肉（SD/N = 12.9）之间实现的良好对比度，将分别包含在T1加权和T2加权图像上的信息整合到了一张图像中，这有助于高效检测和定位恶性肿瘤。
