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Tissue Harmonic Imaging (tissue + harmonic_imaging)
Selected AbstractsORIGINAL INVESTIGATIONS: Tissue Harmonic Imaging in Echocardiography: Better Valve Imaging, But at What Cost?ECHOCARDIOGRAPHY, Issue 2 2008Karin Hawkins M.D. Background: Tissue harmonic imaging (THI) improves echocardiographic image quality and is widely utilized. Unfortunately it also makes structures appear artificially thickened. We sought to examine its impact on the imaging of left-sided heart valves. Methods: A large echocardiographic database was searched for full, standard transthoracic echocardiographic exams performed 12-month periods before (n = 3,786) and after (n = 3,914) transition to THI at a single institution. Patients with prosthetic valves were excluded. Results: The mean age of patients was 63 ± 17 years and 65% were men. No appreciable difference in demographics was observed between time periods. While inadequate visualization of the mitral valve was reduced by 30% using THI (P = 0.014), reports of leaflet thickening increased by 28% (P = 0.005). Similarly, inadequate aortic valve visualization was reduced by 53% with THI (P < 0.001), at the expense of more aortic sclerosis (+6%, P = 0.034). Among the 480 patients with echocardiograms using each modality (time interval between studies: 370 ± 143 days), THI did not appreciably improve visualization of the either valve. Although no significant increase in mitral thickness was seen with THI, aortic sclerosis was increased by at least one grade in 24.5% (P < 0.006). Conclusion: This study suggests that while THI enhances imaging of difficult to visualize valves, it may overestimate mitral and aortic valve thickness. This could lead to overdiagnosis and unnecessary follow-up studies. Cardiologists interpreting THI echocardiograms should become familiar with the modality's shortcomings. [source] CLINICAL USE OF THE NEWLY DEVELOPED ELECTRONIC RADIAL ULTRASOUND ENDOSCOPEDIGESTIVE ENDOSCOPY, Issue 1 2006Masami Ogawa Background:, Endoscopic ultrasonography (EUS) is widely accepted as a diagnostic tool for bilio-pancreatic and gastrointestinal tract diseases. Recently, an ultrasound endoscope with an electronic radial scan transducer has been developed. To evaluate the clinical usefulness of this system, its image quality, advantages and disadvantages were evaluated. Materials and methods:, Ultrasound endoscope with electronic radial scan transducer and its monitor unit were used. The direction of the imaging plane was similar to that of the mechanical radial models. Color Doppler function and tissue harmonic imaging were feasible by this system. To evaluate this endoscope, we investigated the image quality and distance resolution by in-vitro study using thin papers, and 50 patients were examined by this system. Results:, Comparison with the mechanical radial endoscope GF-UM2000 revealed that the image quality was almost equivalent. However, the ultrasound penetration of the electronic radial scanner was better and more satisfactory with less echoic reduction. In addition, the blood-flow signal could be obtained by using the color Doppler function. In contrast, the diameter of the new endoscope was bigger than the advanced mechanical radial models, the monitor unit was bigger than that of the mechanical radial system, and the operation of this unit was complicated. Conclusion:, A prototype of the ultrasound endoscope with electronic radial scan showed satisfactory results regarding the image quality, ultrasound penetration, and clinical diagnosis. The blood flow could be investigated by using the color Doppler function, which is useful to diagnose lesions and detect involvement of the blood vessels in cancers. [source] Tissue harmonic sonography in the diagnosis of common bile duct stones: A comparison with endoscopic retrograde cholangiographyJOURNAL OF CLINICAL ULTRASOUND, Issue 9 2009Tomás Ripollés MD Abstract Purpose To revisit the diagnostic accuracy of sonography in the detection of choledocholithiasis using modern equipment with tissue harmonic imaging (THI) and endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy as the gold standard. Methods A total of 107 patients with clinically suspected choledocholithiasis were examined with THI before undergoing ERCP. The sonographic findings that were prospectively evaluated included the presence of choledocholithiasis, size of common bile duct, sonographic view and patient position that best visualized the stone(s), visualization of the distal common duct, and duration of examination. The accuracy of sonography compared with ERCP and sphincterotomy was calculated. Results Sonography correctly detected stones in 65 of 76 patients (sensitivity of 86%). The specificity and the overall accuracy were 87% and 86%, respectively. The sensitivity of sonography was higher with dilated extrahepatic duct (44% in patients with common bile duct measuring less than 6 mm in diameter, 82% between 6 and 10 mm, and 100% with common bile duct larger than 10 mm). The lateral approach with the patient in left lateral decubitus position of the patient was the most effective in 47% of the cases. Conclusion Sonography with THI is an accurate technique for the detection of choledocholithiasis that may be used as the first-choice technique to avoid unnecessary procedures in a high percentage of patients, especially those with dilated biliary tree. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2009 [source] | ||||||||||