Tanaka Yumiko Oishi, Ohtsuka Sadanori, Shindo Masahi, Katsumata Yasutomo, Oyake Yasuyuki, Minami Manabu
Department of Radiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan.
Magn Reson Imaging. 2005 Oct;23(8):893-7. doi: 10.1016/j.mri.2005.07.006. Epub 2005 Oct 13.
Delayed myocardial enhancement is caused by a variety of cardiovascular diseases. The extent of the enhanced area has been examined by the inversion recovery (IR) method, whereby at the inversion time (TI), normal myocardium shows a low signal intensity. In this sequence, as pericardial fat shows a very high intensity, a delayed enhancement just below the pericardium may be indistinct. To improve the accuracy of delayed myocardial enhancement, we employed the spectral presaturation of inversion recovery (SPIR) method.
Thirty-five patients with symptoms of cardiovascular disease aged between 36 and 80 years old (mean age, 62 years old) were investigated. Thirty were men and five were women. Inversion recovery and SPIR images were obtained 25 min after initial administration of a gadolinium-based contrast material. Each TI, when the signal intensity of the normal myocardium was null, was determined by images obtained at serial different TIs. A radiologist and a cardiologist examined each image by a consensus reading. The extent of myocardial enhancement was described as none, subendocardial, transmural and a random pattern in each case. Images were ranked over three levels and were based on whether myocardial enhancement could be easily detected or whether the contour of the myocardium was visualized precisely. Student's t-test was conducted to compare the quality of two sequences in all patients and in 22 patients who showed delayed myocardial enhancement.
The imaging quality in evaluating delayed myocardial enhancement in all patients was superior with IR compared with SPIR, although it was not statistically significant. The imaging quality in the patients with delayed myocardial enhancement was similar between SPIR and IR. SPIR was superior to the IR sequence in two of the four patients who exhibited transmural enhancement.
SPIR exhibited equivalent image quality to IR in evaluating delayed myocardial enhancement. As it has the potential advantage in patients with rich adipose tissue surrounding the myocardium, it can be an alternative sequence to evaluate myocardial viability.
延迟心肌强化由多种心血管疾病引起。增强区域的范围已通过反转恢复(IR)方法进行检查,在反转时间(TI)时,正常心肌显示低信号强度。在这个序列中,由于心包脂肪显示出非常高的信号强度,心包下方的延迟强化可能不清晰。为提高延迟心肌强化的准确性,我们采用了频谱预饱和反转恢复(SPIR)方法。
对35例年龄在36至80岁(平均年龄62岁)有心血管疾病症状的患者进行研究。其中30例为男性,5例为女性。在首次静脉注射钆对比剂后25分钟获得反转恢复和SPIR图像。通过在一系列不同TI时获得的图像确定每个TI,此时正常心肌的信号强度为零。由一名放射科医生和一名心脏病专家通过共同阅片检查每张图像。每种情况下心肌强化的程度被描述为无、心内膜下、透壁和随机模式。根据心肌强化是否易于检测或心肌轮廓是否能精确显示,将图像分为三个等级。对所有患者以及22例显示延迟心肌强化的患者进行Student t检验,以比较两种序列的质量。
在评估所有患者的延迟心肌强化时,IR序列的成像质量优于SPIR序列,尽管差异无统计学意义。在显示延迟心肌强化的患者中,SPIR和IR序列的成像质量相似。在4例表现为透壁强化的患者中,有2例SPIR序列优于IR序列。
在评估延迟心肌强化方面,SPIR序列的图像质量与IR序列相当。由于其在心肌周围脂肪丰富的患者中具有潜在优势,它可以作为评估心肌活力的替代序列。