ABSTRACT
The focal hepatic lesion caused by local injection of absolute alcohol in rats was evaluated with ultrasonic contrast agent and pathologic examination. Twenty adult Wistar rats weighing about 200 g were injected with absolute alcohol (0.05-0.1 mL each one) on the exterior left lobe of the liver under the monitoring of ultrasound. Pulse inversion harmonic imaging was used to evaluate the focal lesion after bolus injection of ultrasonic contrast agent (0.05 mL/200 g) through caudal vein.Seven days later, the focal lesion was studied again as before. The exterior left lobe of liver with focal lesion was incised and underwent pathologic examination. The results showed that all of the focal lesions could be defined clearly after bolus injection of the ultrasonic contrast agent under the mode of pulse inversion harmonic imaging. There was good correlation between the size of the focal lesion measured by ultrasound on the 7th day after the "ablation" under the mode of pulse inversion harmonic imaging and that gotten by pathologic examination (P=0.39). The focus size measured by ultrasound right after the ablation was larger than that gotten by pathologic examination (P= 0.002). It was concluded that ultrasonic contrast agent plus pulse inversion harmonic imaging could be used to assess the size of the focal hepatic lesion caused by local injection of absolute alcohol in rats.
ABSTRACT
OBJECTIVE: To determine the usefulness of tissue harmonic imaging (THI) and pulse-inversion harmonic imaging (PIHI) in the evaluation of normal and abnormal fetuses. MATERIALS AND METHODS: Forty-one pregnant women who bore a total of 31 normal and ten abnormal fetuses underwent conventional ultrasonography (CUS), and then THI and PIHI. US images of six organ systems, namely the brain, spine, heart, abdomen, extremities and face were compared between the three techniques in terms of overall conspicuity and the definition of borders and internal structures. RESULTS: For the brain, heart, abdomen and face, overall conspicuity at THI and PIHI was significantly better than at CUS (p < 0.05). There was, though, no significant difference between THI and PIHI. Affected organs in abnormal fetuses were more clearly depicted at THI and PIHI than at CUS. CONCLUSION: Both THI and PIHI appear to be superior to CUS for the evaluation of normal or abnormal structures, particularly the brain, heart, abdomen and face.
ABSTRACT
OBJECTIVE: The object of this study was to assess the accuracy of dipyridamole stress intravenous (IV) myocardial contrast echocardiography (MCE) using pulse inversion harmonic imaging and PESDA in the detection of perfusion defect in the patients with coronary artery disease in comparison with dipyridamole stress Tc-99m sestamibi SPECT. METHODS: Total 46 patients (29 males, mean age 64 years old) were consecutively enrolled. Patients with prior myocardial infarction were excluded. MCE and Tc-99m sestamibi SPECT were performed at the same day during rest and after 0.56 or 0.84mg/Kg dipyridamole infusion. Continuous IV infusion of PESDA (2-5 mL/min) was administered while obtaining triggered (1:1) end-systolic apical 2, 4 chamber and long axis views. Tc-99m sestamibi was injected 3 minutes after dipyridamole. Tc-99m sestamibi SPECT images were obtained one hour later. Coronary angiography was followed within two days in all patients. Tc-99m sestamibi SPECT images were matched to the sixteen segments of left ventricle according to American Society of Echocardiography for segmental comparison. Both images were analyzed visually. Results Using coronary angiography as the standard, MCE showed overall sensitivity of 70.7%, specificity of 95.8%, positive predictive value (PPV) of 87.8% and negative predictive value (NPV) of 88.5% in the detection of coronary atherosclerosis (70% stenosis). Tc-99m sestamibi SPECT showed sensitivity of 75.6%, specificity of 98.9%, PPV of 96.8% and NPV of 90.6%. The overall concordance rate between MCE and Tc-99m sestamibi SPECT for the detection of perfusion defects was 86.9% (Cohen's kappa value 0.63) according to the coronary territory and 86.8% (Cohen's kappa value 0.55) according to segmental analysis. CONCLUSION: Dipyridamole stress IV MCE using pulse inversion harmonic imaging and PESDA is feasible and comparable to Tc-99m sestamibi SPECT in identifying significant coronary stenosis and inducible myocardial perfusion defects in the patients with coronary artery disease. MCE using pulse inversion harmonic imaging seems to be a promising modality for assessing myocardial perfusion in the patients with suspected coronary artery disease.