Early and dynamic detection of doxorubicin induced cardiotoxicity by myocardial contrast echocardiography combined with two-dimensional speckle tracking echocardiography in rats

Figures

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  FIGURE 1. Study design. Rats received intraperitoneal DOX (2.5 mg/kg, once a week). Forty rats were randomly divided into the following five groups (8 rats in each group); control: 8 rats received normal saline; Group 1: 8 rats received two intraperitoneal injections of DOX; Group 2: 8 rats received four intraperitoneal injections of DOX; Group 3: 8 rats received six intraperitoneal injections of DOX; Group 4: 8 rats received eight intraperitoneal injections of DOX. MCE and echocardiography scans (probe) were performed in the long-axis planes in each group. All rats were sacrificed for a histopathologic evaluation immediately after the ultrasonic scan.

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  FIGURE 2. DOX treatment impaired cardiac strain. (A) Representative long-axis strain and short-axis strain images [Representative long-axis strain and short-axis strain images (for GCS and GRS analysis, respectively)]. (B) GLS, GRS, and GCS between control and DOX groups (n = 8). (C) Representative strain time curves of the five groups. LV, left ventricle; GLS, global peak longitudinal strain; GRS, global peak radial strain; GCS, global peak circumferential strain; The data are expressed as the means ± SDs. **p < 0.01 versus control, #p < 0.05 versus Group 1, ##p < 0.01 versus Group 1.

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  FIGURE 3. MCE assessed myocardial perfusion during DOX-induced cardiotoxicity development. (A) Representative MCE-based myocardial perfusion images of MCE in the five groups; (B) Representative time–intensity curves in the five groups, MBV = 11.31 dB, β = 12.56/s and MBF = 142.06 dB/s in control, MBV = 10.24 dB, β = 10.43/s and MBF = 106.80 dB/s in group 1, MBV = 10.63 dB, β = 7.86/s and MBF = 83.55 dB/s in group 2; MBV = 8.97 dB, β = 6.49/s and MBF = 58.21 dB/s in group 3; MBV = 7.24, β = 5.63/s and MBF = 40.76 dB/s in group 4; (C) The difference in MBV, wash in slope and MBF between the control and DOX groups. MBV, myocardial blood volume; MBF, myocardial blood flow. The data are expressed as the means ± SDs. *p < 0.05 versus control, **p < 0.01 versus control, ***p < 0.001 versus control; #p < 0.05 versus Group 1, ##p < 0.01 versus Group 1, ###p < 0.001 versus Group 1.

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  FIGURE 4. Typical histopathologic findings in the five groups. (A) Hematoxylin and eosin (HE) staining (×400): there were obvious vacuolar changes in the myocytes in the DOX treated group; (B) Masson’s trichrome staining (×200): myocardial interstitial fibrosis gradually increased and perivascular fibrosis worsened with the progression of DOX treatment; (C) CD31 staining (×400): reduced microvessel numbers in the DOX groups compared with the control.

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  FIGURE 5. Bland-Altman agreement plots of perfusion parameters (MBV, β, MBF). Plots the difference between measurements of two reading or observers and mean measurements. The top and bottom lines show the 95% limits of agreement; the middle line (red) shows the mean difference.