T₂‐prepared SSFP improves diagnostic confidence in edema imaging in acute myocardial infarction compared to turbo spin echo

Abstract

T 2 -weighted MRI of edema in acute myocardial infarction (MI) provides a means of differentiating acute and chronic MI, and assessing the area at risk of infarction. Conventional T 2 -weighted imaging of edema uses a turbo spin-echo (TSE) readout with dark-blood preparation. Clinical applications of darkblood TSE methods can be limited by artifacts such as posterior wall signal loss due to through-plane motion, and bright subendocardial artifacts due to stagnant blood. Single-shot imaging with a T 2 -prepared SSFP readout provides an alternative to dark-blood TSE and may be conducted during free breathing. We hypothesized that T 2 -prepared SSFP would be a more reliable method than dark-blood TSE for imaging of edema in patients with MI. In patients with MI (22 acute and nine chronic MI cases), T 2 -weighted imaging with both methods was performed prior to contrast administration and delayed-enhancement imaging. The T 2 -weighted images using TSE were nondiagnostic in three of 31 cases, while six additional cases rated as being of diagnostic quality yielded incorrect diagnoses. In all 31 cases the T 2 -prepared SSFP images were rated as diagnostic quality, correctly differentiated acute or chronic MI, and correctly determined the coronary territory. Free-breathing T 2 -prepared SSFP provides T 2 -weighted images of acute MI with fewer artifacts and better diagnostic accuracy than conventional dark-blood TSE.

Single‐shot steady‐state free precession can detect myocardial edema in patients: A feasibility study

“…All imaging data for each slice were acquired during a single cardiac cycle. During the subsequent cardiac cycle, a low flip angle single-shot gradient-echo acquisition was used to acquire proton density information for the same slice, which was used to normalize signal intensity, as described previously (9).…”

“…The T 2 /T 1 of edematous myocardium (60 -65 ms/1197 ms) (9,10) is higher than that of normal myocardium (45-50 ms/1011 ms) (9,10), and, therefore, edematous tissue should appear brighter on a T 2 /T 1 -weighted image when compared with normal myocardium.…”

Cardiac MRI: T2-Mapping Versus T2-Weighted Dark-Blood TSE Imaging for Myocardial Edema Visualization in Acute Myocardial Infarction

“…Unfortunately, T2-weighted dark-blood TSE sequences are prone to image artifacts such as signal intensity variations caused by the use of phased-array coils, bright rim artifacts next to the endocardium caused by insufficient suppression of the signal from slow flowing blood, or posterior wall signal loss caused by through-plane motion of the dark-blood prepared slice out of the imaging slice in the case of improper timing [10 -12]. Consequently, Kellman et al showed that T2-weighted dark-blood TSE imaging was either non-diagnostic or incorrect in 29 % of patients with AMI [13]. Recently, a quantitative T2 mapping technique that overcomes these limitations has been introduced for the evaluation of myocardial edema [14].…”

Use of cardiac magnetic resonance imaging in the diagnosis of Takotsubo cardiomyopathy: another imaging feature added

“…In part this is because even for a given patient, there are many other parameters which influence signal intensity and thus a consistent absolute threshold value cannot be utilized. Second, artifacts related to motion, volume averaging, and inability to null areas of static blood can result in areas of increased T2W signal [7,10]. Realizing these limitations, Joshi and colleagues took special care to measure the signal intensity in the epicardial half of the myocardium (i.e.…”