Grading of valvular regurgitation is mandatory for management of patients with valvular heart disease. Simple measurement, satisfactory reliability and reproducibility are required as ideal parameters for clinical use. Each parameter has its coherent value and limitations. All variables do not show concordance in terms of severity. There is no gold standard for quantitating valvular regurgitation. The main purpose of grading is to differentiate mild from moderate severity, or to determine the severity when the clinical profile is not consistent with the severity of cardiovascular findings. Beginners should be familiar with some of the parameters. Distribution of regurgitant signals graded by three or four scales are simple, semi-quantitative, and useful parameters in aortic (AR) and mitral regurgitation (MR). Regurgitant area relative to the size of the atrium is also utilized. Vena contracta, the narrowest portion of the regurgitant jet downstream from the orifice, is a simple parameter in AR and MR. Regurgitant width and area of AR or its ratio to the outflow tract width or area are also variables. Pressure half time and decay slope of regurgitant signal are also utilized in AR. Regurgitant volume, fraction and orifice area can be calculated by proximal isovelocity surface area (PISA), which is independent of the configuration of the regurgitant jet. However, the method is not used for mild regurgitation because of absence of flow convergence. Regurgitant volume and regurgitant fraction calculated by utilizing the continuity equation are other useful Doppler variables, which are not affected by area or distribution of regurgitant signals. It should be emphasized that the above-mentioned parameters are not part of the guidelines of the U.S.A and Japan for timing of valve surgery. Left ventricular dimension, ejection fraction and pulmonary artery pressure have been proposed as much more important variables.

View full abstract

Therapeutic ultrasound has been used mainly for its thermal or mechanical effects. Medical applications of high-energy nonthermal ultrasound to ablate cancers are now being studied. Reports reveal that many diseases are being treated with a combination of ultrasound and drugs. Further, the introduction of microbubbles and nanobubbles to carry and enhance drugs has added a new dimension to therapeutic ultrasound. Pharmaceutical agents developed during the past decade have markedly increased the promise of this technology for molecular biology, gene therapy, and regenerative medicine. Similar promise is offered by the development of new devices: therapeutic ultrasound catheters and extracorporeal ultrasound probes, for example, are being developed, and some are undergoing clinical trials. Advances like use of ultrasound to enhance the effects of thrombolytic agents have proven beneficial in treating patients with acute stroke and occlusion of peripheral arteries. Noninvasive focused ultrasound in conjunction with anticancer drugs may help to reduce tumor size, probability of recurrence, and severity of drug side effects. Last, advances in molecular imaging offer increased promise for both diagnostic and therapeutic ultrasound. Microbubbles or nanobubbles targeted at the molecular level will enable physicians to make a definite diagnoses with diagnostic ultrasound and then proceed immediately to use ultrasound therapeutically.

View full abstract

We carried out transabdominal ultrasonography and other imaging studies on 32 patients with cystic tumors of the pancreas. All subjects had undergone surgical treatment that was confirmed histologically. Twenty-six patients had intraductal papillary mucinous neoplasms (IPMNs). The lesions were main duct type in 8 patients and branch duct type in 18 patients; 6 patients had mucinous cystic neoplasms (MCN). Sixteen of the patients with intraductal papillary mucinous neoplasms had adenocarcinomas, 1 had a borderline lesion, and 9 had adenomas. Intraductal papillary mucinous neoplasms were often found in the head of the pancreas in older men (mean age, 65.8 years). Three of the patients with mucinous cystic neoplasms had adenocarcinomas, and 3 had adenomas, all found in the body and/or tail of the pancreas of women (mean age, 55.0 years). Intraductal papillary mucinous neoplasms with branch duct dilatation were associated with multilocular cysts. Fifteen of 20 patients with mural nodules and 12 of 13 patients with a main pancreatic duct at least 6 mm in diameter had adenocarcinomas or borderline lesions. A unilocular cyst was observed in 1 of the patients with mucinous cystic neoplasms; multilocular cysts enclosed in a common capsule were found in 6 of the others. Three of 4 patients with mural nodules had adenocarcinomas. Mural nodules in intraductal papillary mucinous neoplasms and mucinous cystic neoplasms or a main pancreatic duct 6 mm or more in diameter in intraductal papillary mucinous neoplasms were indicative of malignancy.

View full abstract

Purpose: To validate a reasonable left atrial volume (LAV) measurement in a normal population, multiple echocardiographic methods were used to evaluate normal reference values of LAV. Subjects and Methods: The study subjects consisted of 100 healthy young male adults. Ages ranged from 20 to 45 years (average 25.1±3.6). LA size was measured with the 2D anteroposterior linear dimension (APD); the cubic equation with APD (Cube method); the ellipsoidal formula (Ellip method); and Biplane modified Simpson rule (Biplane method). Three-dimensional echocardiography (3D) was also applied in 22 cases. Results and Discussion: The Cube (16.1±5.0ml) and Ellipsoid (26.3±7.2ml) methods significantly underestimated the LAV compared to the Biplane method (37.9±10.4ml). In 22 cases, no significant difference was observed between LAV derived by 3D method (37.5±11.1ml) and those derived by the Biplane method (37.0±11.0ml). The mean LA volume index (for body surface area) was 22±5, similar to recently quoted values (22±6) reported by Wang et al. Conclusion: LA single or triple linear dimensions derived assumptions were not accurate for LA volume measurements. The Biplane method has the closest agreement to 3D methods and is readily applicable with current echocardiographic equipment. The Biplane method should be routinely applied in clinical practice as already reported.

View full abstract

Purpose: To evaluate the diagnostic value of the liver US score (calculated from the data obtained using high-end ultrasonographic (US) equipment with high-and low frequency probes) for distinguishing early stage cirrhosis from advanced stage chronic hepatitis. Materials and Methods: One hundred patients with biopsy-proven chronic liver disease (advanced stage chronic hepatitis-45 patients and early stage liver cirrhosis-55 patients) comprised the subject population. we used a Philips ATL HDL 5000 SonoCT Ultrasound system (ATL.Co.Ltd) with high-(5-12 Mhz) and low (2-5 MHz) frequency probes for this study. We also compared the US results with splenic size and serum biochemical data. Results: Platelet count was in the normal range in thirty-eight percent of cases of cirrhosis. The number of cases with abnormal prothrombin activity, serum albumin, or total cholesterol was much smaller. Splenomegaly was present in 47 percent of cirrhosis cases. The proportion of liver US scores exceeding 5.5 was 55/55 for stage F4 and 11/45 for stage F3 (LC sensitivity; 100%; specificity, 91%). The proportion of cases with US scores exceeding 6.0 was 54/55 for stage F4 and 4/45 for stage F3 (LC sensitivity, 98%; specificity, 76%), and that with exceeding 6.5 the proportion was 38/55 for F4 and 0/45 for F3 (LC sensitivity, 69%; LC specificity, 100%). The highest LC probability ratio was 11.05. Thus, the liver US score has high sensitivity and specificity in the diagnosis of cirrhosis. Conclusion: Liver US score calculated from the US results obtained by using a high-end US equipment was useful for differentiating between early stage liver cirrhosis and advanced stage chronic hepatitis.

View full abstract

Purpose: In high mechanical index (MI) contrast ultrasonography it has been shown that the power of contrast signal intensity (CI) has a strong linear correlation with the concentration of the ultrasound contrast agent under conditions of constant applied acoustic pressure. However, it is unclear whether the linearity is preserved in low-MI contrast ultrasonography. Thus, we investigated the relationship between ultrasound contrast concentration and CI in vitro. Methods: Solutions of the ultrasound contrast agents Definity and Imagent were prepared at concentrations of 0.5, 2, 8, 32, and 128μL/L. Placing a jelly block between the transducer and the solution, the solutions were transmitted using pulse subtraction imaging with an MI of 0.05, 0.1, and 0.5. CI was measured in dB in a region of interest 3 mm in height placed just below the border between the jelly and the solution. Data were plotted using double logarithm scales, where the concentration was expressed in dB as 10×log (concentration). Results: CI in dB had a strong linear correlation with concentration in dB for both agents with any MI. Best fitted slopes were close to 1, indicating that the power of CI is proportional to the concentration. Conclusions: In low-MI contrast ultrasonography, the power of CI is proportional to contrast concentration, and CI in dB is logarithmic to the concentration. Thus, the microbubble concentration can be quantitatively measured even in low-MI contrast ultrasonography.

View full abstract

A 63-year-old female was admitted to our hospital suffering from abdominal pain with anemia and liver dysfunction on hematological examination. She had undergone percutaneous liver biopsy eight days before because of suspected autoimmune hepatitis. Ultrasound examination on admission revealed dilatation of the common bile duct and color Doppler sonogram showed “color mosaic appearance” at the anterior segment, the site of the prior percutaneous biopsy in the right lobe of the liver. The waveform of the signal on pulsed Doppler sonogram showed a predominant turbulent flow, which was considered to correspond to pseudoaneurysm secondary to liver biopsy. Since endoscopy examination showed bleeding at the orifice of the papilla vater, she was diagnosed with hemobilia secondary to liver biopsy, and biliary drainage was performed. Following this, without having to resort to transcatheter arterial embolization (TAE), she showed no bleeding, and both the clinical symptom and laboratory data improved. The “color mosaic appearance” disappeared following a decrease in size, as did the turbulent flow, and she was released. A “color mosaic appearance” on color Doppler sonogram may be an important sign for the early diagnosis of intrahepatic pseudoaneurysm, and its reduction or disappearance may be predictive for recovery from the condition without TAE or other intensive treatment.

View full abstract

Background: Identifying a focus of premature ventricular contraction (PVC) in cardiac electrophysiology has been facilitated by the development of the electro-anatomical mapping system (CARTO system^®). The echocardiographic tissue tracking method utilizing the tissue Doppler method can quantify the process of propagation of myocardial contraction. Purpose: To compare the clinical usefulness of the tissue tracking method by comparing its results with results obtained for a focus of PVC identified from an activation map produced using the electro-anatomical mapping system. Methods: The subjects examined were two patients with drug-resistant PVC who had been admitted for catheter ablation for low cardiac function. After identifying the focus of PVC with the tissue tracking method, we acquired an activation map produced using the electro-anatomical mapping system, and compared it with the focus of PVC identified by the tissue tracking method. Results: The tissue tracking method showed a focus of PVC near the left ventricular outflow tract in both cases. The electro-anatomical mapping system showed the focus of PVC near the right ventricular outflow tract in case 1 and near the left ventricular outflow tract in case 2. Although catheter ablation did not resolve PVC, PVC disappeared on catheter ablation of the left coronary cusp of the aortic valve. We thus judged the left coronary cusp to be the likely focus. This focus was deemed to be consistent with the region identified by the tissue tracking method. Conclusion: The results recommend the tissue tracking method as simple, noninvasive, and useful in evaluating and identifying the focus of PVC.

View full abstract