Myocardial contrast echocardiography with a new calibration method can estimate myocardial viabilityin patients with myocardial infarction
Akio Yano, MD*,
Hiroshi Ito, MD, FACC*,*,
Katsuomi Iwakura, MD*,
Ryusuke Kimura, MD*,
Kouji Tanaka, MD*,
Atsunori Okamura, MD*,
Shigeo Kawano, MD*,
Tohru Masuyama, MD, FACC and
Kenshi Fujii, MD*
* Division of Cardiology, Sakurabashi Watanabe Hospital, Osaka, Japan
Department of Internal Medicine and Therapeutics, Graduate School of Medicine, Osaka University, Osaka, Japan
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Figure 1 Measurements of contrast intensity (CI) in the left ventricular (LV) myocardium and adjacent LV cavity on the myocardial contrast echocardiography (MCE) image. The LV myocardium was divided into six segments in each apical four- and two-chamber view (left). As shown in an HPD image of the apical four-chamber view (right), for example, the ROIs (12 blue ovoid shapes in the image) were placed in each segment and each adjacent LV cavity. See text for details. Myocardial segments: AA = apical anterior; AI = apical inferior; AL = apical lateral; AS = apical septum; BA = basal anterior; BI = basal inferior; BL = basal lateral; BS = basal septum; MA = mid-anterior; MI = mid-inferior; ML = mid lateral; MS = mid-septum.
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Figure 2 Temporal changes in myocardial contrast intensity (CI) and calibrated CI after bolus injection of Levovist in normal volunteers. Relationships of time points with myocardial CI (left) and calibrated CI (right) at 12 myocardial segments are shown. Data points (circles) indicate the mean values at 12 different segments. Standard deviation (SD) ranged from 1.4 to 2.3 dB. Rectangles and vertical lines at both sides indicate the mean value ± SD among all normal segments. Myocardial CI significantly decreased from 60 to 100 s after injection. Calibrated CI showed no remarkable change, however.
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Figure 3 Comparison of myocardial contrast intensity (CI) and calibrated CI in 12 myocardial segments in normal volunteers. Myocardial CI (left) differed among myocardial segments in the apical four- and two-chamber views. It was the highest in the apical segments and the lowest in the basal segments. After the calibration (right), the intersegmental differences significantly decreased. All bars indicate the mean value ± SD, and the mean values are expressed with them. Abbreviations of myocardial segments are the same as in Figure 1.
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Figure 4 Comparisons of myocardial contrast intensity (CI) and calibrated CI among myocardial segments in normal subjects, as well as kinetic and akinetic segments in patients with myocardial infarction (MI). Data points indicate all values of myocardial CI (left) and calibrated CI (right). Rectangles and vertical lines indicate the mean value ± SD. Myocardial CI at the akinetic segments was significantly lower than that at the normal and kinetic segments, although it was almost the same at normal and kinetic segments. However, there was a large overlap of data ranges between kinetic and akinetic segments. On the other hand, calibrated CI at the akinetic segments was also significantly lower than that at the other segments. Here, it should be noted that the overlap was obviously small compared with that in plain myocardial CI. It is expected that they will be easily distinguished after the calibration.
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Figure 5 Color-coded map of calibrated contrast intensity (CI) in a patient with normal contraction. (Left) An HPD image in the apical four-chamber view was analyzed. (Right) In this case, all segments showed warm colors, implying calibrated CI >–18.0 dB. Note that the box colors indicate calibrated CI in the subendocardial layer, not the averaged value of the segment. See text for details.
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Figure 6 Color-coded map of calibrated contrast intensity (CI) in a patient with anterior myocardial infarction (MI). (Left) An HPD image in the apical four-chamber view shows a reduced contrast enhancement zone extending from the distal septum to cardiac apex. (Right) After the analysis with VoluMap, the mid-septum to apical region shows cool colors, indicating calibrated CI  –18.0 dB. See text for details.
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