Fieno David S, Jaffe Wyatt C, Simonetti Orlando P, Judd Robert M, Finn J Paul
Feinberg Cardiovascular Research Institute and Department of Radiology, Northwestern University Medical School, Chicago, Illinois 60611, USA.
J Magn Reson Imaging. 2002 May;15(5):526-31. doi: 10.1002/jmri.10107.
To test the accuracy of a high performance true fast imaging with steady-state precession (TrueFISP) pulse sequence for the assessment of left ventricular (LV) mass in a large animal model on 1.5-T scanners.
We imaged dogs (N = 10) on a clinical 1.5-T clinical scanner using electrocardiogram (ECG)-gated TrueFISP. In all animals, contiguous segmented k-space cine images were acquired from base to apex (in-plane resolution 1 x 1 mm(2), slice thickness 5 mm, TR = 4.8 msec, TE = 1.6 msec) during repeated breath-holds. In nine of the 10 animals, single-shot images gated to end-diastole were also acquired from base to apex in a single breath-hold (in-plane resolution 1 x 1 mm(2), slice thickness 5 mm, TR = 3.2 msec, TE = 1.6 msec). After imaging, animals were killed, the left ventricle was isolated, and the true mass of the left ventricle (free wall and septum) was determined. Independently, two observers blinded to the post-mortem results computed LV masses based on analysis of the magnetic resonance (MR) images.
Comparison of the computed LV mass using TrueFISP to the actual mass showed excellent agreement. Cine-systole was the most accurate technique (mass = 98.6% +/- 4.5% actual, bias = 1.2 +/- 3.4 g) followed by cine-diastole (mass = 97.9% +/- 5.3% actual, bias = 1.8 +/- 4.1 g) and single shot (mass = 94.7% +/- 7.9% actual, bias = 4.2 +/- 6.3 g). Inter- and intra-observer variabilities were low (5.8% +/- 7.1% and 0.4% +/- 4.8%, respectively).
We conclude that TrueFISP imaging is an accurate, rapid method to determine ventricular mass. In single-shot mode, TrueFISP requires only one breath-hold to estimate the mass of the heart within 6% of the actual value, whereas the segmented k-space implementation measured LV mass to within 3% of the true value.
在1.5-T扫描仪上的大型动物模型中，测试稳态进动快速成像（TrueFISP）脉冲序列评估左心室（LV）质量的准确性。
我们使用心电图（ECG）门控的TrueFISP在临床1.5-T临床扫描仪上对犬（N = 10）进行成像。在所有动物中，在重复屏气期间从心底到心尖采集连续分段的k空间电影图像（平面分辨率1×1 mm²，层厚5 mm，TR = 4.8毫秒，TE = 1.6毫秒）。在10只动物中的9只中，还在一次屏气中从心底到心尖采集了门控至舒张末期的单激发图像（平面分辨率1×1 mm²，层厚5 mm，TR = 3.2毫秒，TE = 1.6毫秒）。成像后，处死动物，分离左心室，并确定左心室（游离壁和室间隔）的实际质量。另外，两名对尸检结果不知情的观察者基于磁共振（MR）图像分析计算LV质量。
使用TrueFISP计算的LV质量与实际质量的比较显示出极佳的一致性。电影收缩期是最准确的技术（质量为实际质量的98.6%±4.5%，偏差为1.2±±3.4 g），其次是电影舒张期（质量为实际质量的97.9%±5.3%，偏差为1.8±4.1 g）和单激发（质量为实际质量的94.7%±7.9%，偏差为4.2±6.3 g）。观察者间和观察者内的变异性较低（分别为5.8%±7.1%和0.4%±4.8%）。
我们得出结论，TrueFISP成像是一种准确、快速的确定心室质量的方法。在单激发模式下，TrueFISP仅需一次屏气就能在实际值的6%范围内估计心脏质量，而分段k空间成像测量LV质量在真实值的3%范围内。
