Myocardial wall motion and thickening assessment in early gated SPECT images of acute coronary syndrome patients likely to have inferolateral perfusion defects

Abstract

The purpose of this study was to compare semi-quantitative visual scores of perfusion, motion and thickening with an automated hypoperfusion index (HI) in patients with suspected acute inferolateral perfusion defects. In the absence of perfusion defects motion and thickening abnormalities were assessed. Sixty-eight patients with chest pain at rest and either ST depression ≥0.1 mV in ≥1 of leads I, aVL, V1-V6 on 12-lead ECG or ST elevation ≥0.05 mV in ≥1 posterior lead on the body surface map comprised the study population. A rest gated perfusion scan was performed within 24 h of symptoms. Scans were scored for perfusion, motion and thickening semi-quantitatively. The scores were compared to the automated HI. A 12 h Troponin T >0.09 ng/ml indicated myocardial infarction (MI). Sixty-five patients (96%, 65/68) had MI. The summed perfusion score correlated well with the HI (ρ = 0.90, P < 0.01) and agreement between scorers was good (κ = 0.77, 95% CI = 0.57-0.94). The summed motion score correlated with the HI (ρ = -0.61, P < 0.01) and agreement between scorers was moderate (κ = 0.65, 95% CI = 0.52-0.79). Summed thickening score correlated with HI (ρ = -0.67, P < 0.01) and agreement between scorers was good (κ = 0.74, 95% CI = 0.64-0.88). Of the 1156 segments assessed (68 × 17), 542 had normal perfusion. Of these normally perfused segments, 113 (21%, 113/542) had a motion abnormality and 102 (19%, 102/542) had a thickening abnormality. Three patients with proven myocardial infarction had normal myocardial perfusion (HI ≤ 5) but exhibited wall motion and thickening abnormalities. In conclusion, assessment of wall motion and thickening in addition to perfusion in acute myocardial perfusion imaging may improve the diagnostic sensitivity for acute MI. Of the scores addressing motion and thickening, interobserver agreement was better for the summed thickening score.

Cardiovascular imaging 2010 in the International Journal of Cardiovascular Imaging

“…It can help to discriminate true perfusion defects from artifacts and disturbances of wall motion and/or thickening in normally perfused areas may indicate areas of myocardial stunning [30]. Neill et al [31] nicely underscored the importance of gated SPECT imaging in the early phase of myocardial infarction. They evaluated 68 patients with chest pain at rest and ECG abnormalities in the inferolateral region.…”

Effect of data conserving respiratory motion compensation on left ventricular functional parameters assessed in gated myocardial perfusion SPECT

“…2 Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland. 3 Department of Medical Physics, Central Finland Central Hospital, Jyväskylä, Finland.…”

“…Myocardial perfusion (MP) single-photon emission computed tomography (SPECT) examination is often performed in the diagnosis of coronary artery disease [1]. Cardiac gating of MP-SPECT examination further enables objective assessment of left ventricular (LV) functional parameters [2], which provide additional information in, for example, diagnosis of myocardial infarction [3], identification of multiple-vessel disease [4], prediction of mortality [5], and identification of patients with risk for LV remodeling [6]. In addition, evaluation of LV mechanical dyssynchrony with phase analysis [7] may help to interpret whether the patient would benefit from cardiac resynchronization therapy [8,9].…”

Gated myocardial SPECT imaging; true additional value in AMI?

“…In the current issue of the International Journal of Cardiovascular Imaging , Neill et al [51] used gated SPECT imaging at rest to compared semi-quantitative visual scores of perfusion, motion and thickening with an automated hypoperfusion index in patients with suspected acute inferolateral perfusion defects. In the absence of perfusion defects motion and thickening abnormalities were assessed.…”

“…On the other hand, wall motion and/or thickening disturbances in normally perfused areas may unravel pathophysiological states such as myocardial stunning. Such a gated approach should be routinely used in evaluating myocardial SPECT images and this is validly underscored by the study of Neill et al [51]. …”