Doppler Color Flow Mapping Research Articles

A Follow-up Study of Neonatal Interatrial Shunt with Echocardiography until Twelve to Fifteen Months of Age

To assess the incidence and natural history of full-term neonates with interatrial shunt (IAS). A follow-up study of 1389 neonates who received screening echocardiography between 2003 and 2006. Babies with IAS at 2 to 4 days of life underwent follow-up echocardiography at 2 to 4 months, 6 to 9 months and 12 to 15 months of age until closure of IAS. The ratio of IAS was 68.3% initially. No significant demographic differences were identified between infants with and without initial IAS. Among 949 neonates with initial IAS, 84.5% infants had a left-to-right interatrial shunt, 13.5% had bidirectional shunt and 2% had predominantly right-to-left shunt. The persistence rate of IAS at 12 to 15 months of age was 3.8% (44/1166). The initial size of IAS ranged from 1.2 to 7.7mm (4.3+/-1.1 mm) detected by color Doppler flow mapping and cases were divided into three groups: small (< or =5 mm), medium (5 to 8 mm) and large group (> or =8 mm). There were 74.6% infants in the small group and 25.4% in the medium group initially. The neonates in the initial small group would always see their IAS close or else they would remain in the small group. Those in the final medium and large size groups always came from the initial medium group. The late closure rate of IAS was 93.9% of infants with initial IAS. The closure curves of initial small and medium sized groups were significantly different, and their late closure rates were 95.1% and 90.4%, respectively. IAS was very common during early neonatal stage, but most cases would close after 1 year. The late closure rate of initial IAS was different if using a cutpoint of 5 mm.

Ventricular septal dissection after patch repair of an infarct-related ventricular septal rupture

Fig. 1. Contrast enhanced MRI precisely shows a detachment in the anterior part of the patch with partial dissection of the septum most likely related to the rest of the necrotic septal tissue after unavoidable early patch closure of the VSD due to unstable hemodynamics of the patient. Re-closure of the defect was performed with a continuous pledged reinforced suture via a left ventricular paraseptal approach. The patient’s symptoms of congestive heart failure disappeared completely after the re-closure and the echocardiographic evaluation before discharge showed no residual shunt. The two-dimensional echocardiography with color flow Doppler mapping is the diagnostic tool of choice in such cases; however, it has shortcomings regarding the exact demonstration of the underlying pathology in recurrent defects. Magnetic resonance imaging is more advantageous by precisely reproducing the pathoanatomic structures of the desired region, hence enabling the cardiac surgeon to plan the definite operative strategy for re-closure. RV, right ventricle; LV, left ventricle; 1, ventricular septal dissection; 2, patch detachment; 3, patch.

Effects of Changing Blood Viscosity and Heart Rate on Vena Contracta Width as Evaluated by Color Doppler Flow Mapping. An In Vitro Study with a Pulsatile Flow Model

There is only limited knowledge on how the quantification of valvular regurgitation by color Doppler is affected by changing blood viscosity. This study was designed to evaluate the effect of changing blood viscosity on the vena contracta width using an in vitro model of valvular insufficiency capable of providing ample variation in the rate and stroke volume. We constructed a pulsatile flow model filled with human blood at varying hematocrit (15%, 35%, and 55%) and corresponding blood viscosity (blood/water viscosity: 2.6, 4.8, 9.1) levels in which jets were driven through a known orifice (7 mm2) into a 110 mL compliant receiving chamber (compliance: 2.2 mL/mmHg) by a pulsatile pump. In addition, we used variable pump stroke volumes (5, 7.5, and 10 mL) and rates (40, 60, and 80 ppm). Vena contracta region was imaged using a 3.5 MHz transducer. Pressure and volume in the flow model were kept constant during each experimental condition, as well as ultrasound settings. Blood viscosity variation in the experimental range did not induce significant changes in vena contracta dimensions. Also, vena contracta width did not change from normal to low hematocrit and viscosity levels. A very modest increase only in vena contracta dimension was observed at very high level of blood viscosity when hematocrit was set to 55% . Pump rate, in the evaluated range, did not influence vena contracta width. These results in controlled experimental settings suggest that the vena contracta is an accurate quantitative method for quantifying valvular regurgitation even when this condition is associated with anemia, a frequent finding in patients with valvular heart disease.

Noninvasive assessment of left-to-right shunting in ventricular septal defects by the proximal isovelocity surface area method on Doppler colour flow mapping

The proximal isovelocity surface area (PISA), which is the zone of flow convergence appearing on the left ventricular septal surface where flow approaching the defect accelerates, allows quantitative estimation of ventricular septal defect (VSD) flow and defect area on colour Doppler imaging. In the present study, the clinical applicability and reliability of the PISA method in assessing the amount of left-to-right shunting in patients with VSDs were evaluated. Fifty-eight patients aged 0.25 to 15 years (mean age 4.3+/-4.4 years) with VSDs were prospectively studied. Maximum PISA radius in peak systole (r), peak velocity (V(max)) and velocity time integral (VTI(VSD)) of flow through the VSD were measured. In addition, peak VSD flow (2pir(2) Nyquist limit [NL]), amount of left-to-right shunting (Qp-Qs = heart rate x [2pir(2) x NL x VTI(VSD)]/V(max)) and defect area ([2pir(2) x NL]/V(max)) were calculated. There were significant positive correlations between Qp-Qs values calculated by PISA and other spectral Doppler methods using the cross-sectional area, as well as the VTI of pulmonary-aortic (r=0.73, P<0.001) or mitral-tricuspid (r=0.58, P<0.001) flows and cardiac catheterization (20 patients, r=0.82, P<0.001). PISA-derived left-to-right-shunting discriminated moderate to large defects from small defects, which were classified according to the catheter-derived Qp/Qs ratio (2 or greater versus less than 2; P=0.001) or clinical evaluation (P<0.001). The present study demonstrated that the PISA method is a reliable semiquantitative method to determine the amount of left-to-right shunting of VSDs and to discriminate moderate to large defects from small defects. Consequently, this method may serve as a simple and useful adjunct to conventional spectral Doppler methods in the noninvasive assessment of patients with VSDs.

Hypoplastic Left Heart Syndrome With Atrial Level Restriction in the Era of Prenatal Diagnosis

Despite recent improvements in survival of patients with hypoplastic left heart syndrome, those with severe atrial level restriction continue to face higher rates of mortality. We sought to assess the impact of prenatal diagnosis and immediate intervention on the outcome of this high-risk population. We performed a retrospective review of patients with hypoplastic left heart syndrome and restriction at the atrial level born between 1997 and 2006. Patients with an intact atrial septum or an interatrial communication less than 2 mm by color Doppler flow mapping on initial postnatal study, or evidence of obstruction to left atrial egress on fetal echocardiogram, were included. Patients were subdivided into two groups based on severity of obstruction. Thirty-eight patients met inclusion criteria; 16 had the most severe form of anatomic obstruction (group 1), and 22 had a lesser degree of obstruction (group 2). Thirty-day cumulative survival for all was 68%: 38% for group 1 and 94% for group 2 (p = 0.001). Twenty-six of the 38 patients (68%) were prenatally diagnosed. Prenatal diagnosis did not improve initial hospital survival or cumulative survival for either group. Eight patients had progression of atrial level restriction from the first fetal study to the first postnatal study. Seven patients prenatally diagnosed with severe restriction underwent planned cesarean section followed by immediate surgical or catheter-based intervention, with only 2 survivors (28%). Hypoplastic left heart syndrome with an intact atrial septum is a highly lethal condition despite prenatal diagnosis and immediate intervention at birth. Fetal intervention should be considered for these high-risk fetuses.

Fetal cardiac ventricle volumetry in the second half of gestation assessed by 4D ultrasound using STIC combined with inversion mode

Quantification of fetal heart ventricle volume can aid in the evaluation of functional and anatomical aspects of congenital heart disease. The aim of this study was to establish nomograms for ventricular volume using three-dimensional (3D) inversion mode ultrasonography with the spatio-temporal image correlation (STIC) modality and to calculate ejection fraction and stroke volume. The fetal heart was scanned using the STIC modality, during fetal quiescence with abdomen uppermost, at an angle of 30-50 degrees , without color Doppler flow mapping. In post-processing, starting with the classic four-chamber view plane in the A-frame, the reference point was moved to the center of the ventricle. The operator used the edit volume followed by Virtual Organ Computer-aided AnaLysis (VOCAL) mode options; in manual trace the VOCAL settings were set to 15 degrees . The trace was drawn and included the myocardium; inversion mode thresholding provided the volume of the intraventricular (anechoic) voxels within the region of interest. The total volume and the intraventricular volume were displayed. The process was repeated for right (R) and left (L) ventricles at end diastole (EDV) and end systole (ESV). The stroke volume (SV = EDV - ESV) and ejection fraction (EF = SV/EDV) were calculated from these measurements. Intraclass correlation was used to evaluate intra- and interobserver agreement. One hundred fetuses ranging from 20 + 5 to 40 + 0 gestational weeks were included in the study. In addition, six fetuses diagnosed during the study period with a cardiac anomaly were examined and their ventricular volumes compared with those of the main study group. LEDV ranged from a mean of 0.53 cm(3) at midgestation to a mean of 3.96 cm(3) at term. LESV ranged from a mean of 0.17 cm(3) at midgestation to 1.56 cm(3) at term. REDV ranged from a mean of 0.68 cm(3) at midgestation to a mean of 5.44 cm(3) at term. RESV ranged from a mean of 0.26 cm(3) at midgestation to 2.29 cm(3) at term. Total stroke volume ranged from a mean of 0.78 cm(3) at midgestation to a mean of 5.5 cm(3) at term. The mean right : left ventricle ratio was 1.4, and left ejection fraction ranged from 42.5 to 86% in these fetuses. Nomograms were created for RESV, LESV, REDV, LEDV and total stroke volumes vs. estimated fetal weight and gestational age. Intra- and interobserver agreement reached 96%. 3D inversion mode sonography combined with STIC represents a simple and reproducible method for estimating fetal cardiac ventricle volume. This innovative methodology may add to overall evaluation of cardiac volume and function, and improve our understanding of normal and abnormal cardiac structure, as well as the severity and prognosis of cardiac lesions.

Regurgitant Jet Direction in Patients With Prolapse of the Anterolateral Scallop of the Posterior Mitral Valve Leaflet

THE ORIENTATION and direction of jets of mitral regurgitation (MR) often provide the echocardiographer with important clues regarding the precise nature of valvular pathology. For instance, a large body of literature supports the concept that prolapse of the posterior mitral valve leaflet (PMVL) results in an anteriorly directed jet of MR, whereas prolapse of the anterior mitral valve leaflet (AMVL) results in a posteriorly directed jet of MR. 1 Otto C.M. Textbook of Clinical Echocardiography. (ed 2). Saunders, Philadelphia, PA2000: 288-289 Google Scholar , 2 Steward W.J. Griffin B. Thomas J.D. Multiplane transesophageal echocardiographic evaluation of mitral valve disease. Am J Card Imaging. 1995; 9: 121-128 PubMed Google Scholar , 3 Steward W.J. Currie P.J. Salcedo E.E. et al. Evaluation of mitral leaflet motion by echocardiography and jet direction by Doppler color-flow mapping to determine the mechanism of mitral regurgitation. J Am Coll Cardiol. 1992; 20: 1353-1361 Abstract Full Text PDF PubMed Scopus (126) Google Scholar , 4 Shyu K. Lei M. Hwang J. et al. Morphologic characterization and quantitative assessment of mitral regurgitation with ruptured chordae tendinae by transesophageal echocardiography. Am J Cardiol. 1992; 70: 1152-1156 Abstract Full Text PDF PubMed Scopus (18) Google Scholar , 5 Himelman R.B. Kusumoto F. Oken K. et al. The flail mitral valve: Echocardiographic findings by precordial and transesophageal imaging and Doppler color-flow mapping. J Am Coll Cardiol. 1991; 17: 272-279 Abstract Full Text PDF PubMed Scopus (52) Google Scholar , 6 Sochowski R.A. Chan K. Ascah K.J. et al. Comparison of accuracy of transesophageal versus transthoracic echocardiography for the detection of mitral valve prolapse with ruptured chordae tendinae (flail mitral leaflet). Am J Cardiol. 1991; 67: 1251-1255 Abstract Full Text PDF PubMed Scopus (32) Google Scholar , 7 Pearson A.C. St. Vrain J. Mrosek D. et al. Color Doppler echocardiographic evaluation of patients with a flail mitral leaflet. J Am Coll Cardiol. 1990; 16: 232-239 Abstract Full Text PDF PubMed Scopus (46) Google Scholar However, as the 2 following cases show, patients with prolapse of the anterolateral scallop of the PMVL (P1) may present with posteriorly directed jets of MR, thus potentially confounding correct identification of the diseased scallop.

Drenagem anômala total das veias pulmonares, em sua forma infracardíaca: desafio diagnóstico

Infracardiac total anomalous pulmonary venous drainage can be erroneously diagnosed as respiratory distress of several different etiologies during the neonatal period. A cross-sectional echocardiography study with Doppler color flow mapping can preoperatively determine the precise drainage site and pulmonary venous return pattern, thereby allowing cardiac surgery to be performed promptly, prior to any clinical deterioration.

Real-time three-dimensional echocardiography: technological gadget or clinical tool?

The complex anatomy of cardiac structures requires three-dimensional spatial orientation of images for a better understanding of structure and function, thereby improving image interpretation. Real-time three-dimensional echocardiography is a recently developed technique based on the design of an ultrasound transducer with a matrix array that rapidly acquires image data in a pyramidal volume. The simultaneous display of multiple tomographic images allows three-dimensional perspective and the anatomically correct examination of any structure within the volumetric image. As a consequence, it is less operator-dependent and hence more reproducible. Dedicated software systems and technologies are based on high-performance computers designed for graphic handling of three-dimensional images by providing possibilities beyond those obtainable with echocardiography. This methodology allows simultaneous display of multiple superimposed planes in an interactive manner as well as a quantitative assessment of cardiac volumes and ventricular mass in a three-dimensional format without a pre-established assumption of cardiac chamber geometry. In addition, myocardial contraction and/or perfusion abnormalities are clearly identified. Finally, real-time three-dimensional colour Doppler flow mapping enables complete visualisation of the regurgitant jet and new ways of assessing regurgitant lesion severity. Thus, this technique expands the abilities of non-invasive cardiology and may open new doors for the evaluation of cardiac diseases. In this article, current and future clinical applications of real-time three-dimensional echocardiography are reviewed.

Early detection of a congenital coronary artery fistula in a neonate by Doppler color flow mapping

To describe a case of a congenital coronary artery fistula in a neonate with the diagnostic and surgical modalities used to manage this condition. A full-term infant was recently diagnosed with a coronary artery fistula. The patient was a term neonate, born without complications, which then appeared to be cyanotic and had a significant heart murmur. Echocardiography demonstrated a large right coronary fistula measuring 7 mm in diameter entering the right ventricle and a small patent ductus arteriosus (PDA) with a left to right shunt. The patient subsequently had patch closure of the coronary artery fistula and ligation of the PDA. Recovery followed from the procedure without apparent intra-operative or post-operative complications. Prompt diagnosis and surgical management of the neonate with a coronary fistula is essential to reduce the morbidity and mortality that may result from this condition.

Patency or recanalization of the arterial duct after surgical double ligation and transfixion

The frequency of residual shunting or recanalization was investigated in patients in whom a persistently patent arterial duct had been doubly ligated and transfixed during surgical closure. We investigated in retrospective fashion for any residual shunting 325 patients who, between January 1990 and December 2004, had undergone surgical double ligation and transfixion of a persistently patent arterial duct. Shunting was discovered in 10 patients, of whom four male and six female. Of those with residual shunting. 4 patients had initially exhibited only persistent patency of the duct, while the other 6 had associated mild cardiac lesions. The mean age at operation was 5.5 years, with a range from 0.5 to 17.9 years. Postoperatively, the mean period for detecting the residual shunt was 22.8 months, with a range from 2 days to 72 months. The frequency of residual shunting amongst our patients, therefore, was 3.1%. We detected the residual shunt by colour-flow Doppler mapping in all patients, although a continuous murmur was heard in only one patient on physical examination. Our findings suggest that clinical sensitivity of detecting residual shunting subsequent to surgical closure of the persistently patent arterial duct is low, and hence that colour-flow Doppler interrogation should be a part of follow up. Residual shunting, or recanalization, may occur even after double ligation and transfixion of the duct. Since the residual flow may emerge after months, or even years, follow-up is needed for longer periods.

Ultrasonic assessment of abnormal umbilical cord and its circulation

Since an abnormal umbilical cord such as excessive twisting/torsion, cord compression, coiling at the fetal neck are fetal life threatening or restrict fetal growth, it is diagnosed in detail by real time B-mode ultrasound, color Doppler flow mapping, pulsed Doppler flow velocity wave form, ultrasonic fetal monitor and actocardiogram. Abnormality is evaluated by its location, size, twisting and its pitch of the cord, the grade of variable deceleration (VD), non-invasive stress CTG test in maternal movement, RI and PI, absent or reverse flow of end diastole (ARED) of umbilical arterial blood flow velocity wave form, and particularly pulsating blood flow wave of the umbilical vein related to blood stagnation in the vein and pathological vascular changes of the placental villi, fetal and neonatal blood vessels. Its treatment is maternal position change in mild cord compression, while bed rest and total tocolysis is required when the compression signs are heavy in early pregnancy. The fetus is rescued by cesarean section when threatened fetal life is indicated by signs of severe FHR change or ARED with umbilical vein flow pulsation in spite of eager conservative treatment. CNS damage of the neonate, e.g. periventricular leukomalacia (PVL) and hypoxic-ischemic encephalopathy (HIE), is inspected and treated if necessary after cesarean section.

Semiquantitative and Quantitative Color Flow Mapping Methods

Conventional pulsed and continuous-wave Doppler applications have been in use since the mid-1970s. The first color flow mapping system was a color m-mode instrument developed by a Swiss engineer named Brandistini. Stevenson and coworkers utilized this system for cardiac sonographic examinations in the late 1970s, but in general, there was very little interest in the method until the early 1980s, when a 2D color flow mapping system became available. With this new technology and the interest it generated, the development in color flow mapping Doppler technology moved at a rapid pace.

A Duplicate Inferior Vena Cava?

A YOUNG ADULT underwent transthoracic echocardiography because of a heart murmur. On attempted 2-dimensional imaging and Doppler color-flow mapping of the inferior vena cava (IVC), 2 large veins were seen to pass from the liver to the right atrium. What is the anomaly in Figure 1?

Ultrasonic assessment of abnormal umbilical cord and its circulation

AbstractSince an abnormal umbilical cord such as excessive twisting/torsion, cord compression, coiling at the fetal neck are fetal life threatening or restrict fetal growth, it is diagnosed in detail by real time B-mode ultrasound, color Doppler flow mapping, pulsed Doppler flow velocity wave form, ultrasonic fetal monitor and actocardiogram. Abnormality is evaluated by its location, size, twisting and its pitch of the cord, the grade of variable deceleration (VD), non-invasive stress CTG test in maternal movement, RI and PI, absent or reverse flow of end diastole (ARED) of umbilical arterial blood flow velocity wave form, and particularly pulsating blood flow wave of the umbilical vein related to blood stagnation in the vein and pathological vascular changes of the placental villi, fetal and neonatal blood vessels. Its treatment is maternal position change in mild cord compression, while bed rest and total tocolysis is required when the compression signs are heavy in early pregnancy. The fetus is rescued...

Hematosalpinx: an unusual complication after medical abortion with oral mifepristone and misoprostol

We report a case of unilateral hematosalpinx after medical abortion with oral mifepristone/misoprostol, a technique being increasingly used in current obstetric practice in Taiwan. A 36 year-old pregnant woman, gravida 3 para 2, attended for medical abortion counseling at 6 weeks' gestation. She had previously undergone laparoscopic enucleation of a left ovarian endometrioma and pelvic adhesiolysis, and had subsequently had two Cesarean sections for obstetric indications. Transvaginal ultrasonographic examination showed a viable intrauterine embryo of compatible gestational age and unremarkable bilateral adnexa. After thorough counseling, the couple elected to undergo medical abortion with oral mifepristone (600 mg) followed 48 hours later by 400 µg of oral misoprostol. She returned 1 week later for a follow-up ultrasound scan and complained of abdominal cramping. On ultrasound examination the intrauterine gestational tissue had been expelled completely but a large (7 cm) heterogeneous echogenic left adnexal mass (Figure 1), thought to be a hematosalpinx, was noted. Color Doppler flow mapping showed no intratumoral blood flow with peripheral low-velocity and high-resistance flow signals (resistance index (RI) = 0.78). Her serum CA125 level was elevated, at 887 U/mL. The left hematosalpinx resolved completely 4 months later. At the time of writing she has been followed up for over a year and has had an uneventful clinical course. Follow-up ultrasonographic examination 1 week after medical abortion showed a heterogeneous echogenic left adnexal mass (M). Mifepristone (RU-486), an antiprogestin, has more than double the binding affinity for progesterone receptor as does progesterone itself1. The actions of mifepristone on the reproductive system make it a useful agent for abortion. Misoprostol, an orally active and inexpensive prostaglandin E1 analog, increases uterine activity especially when used in conjunction with mifepristone. Current evidence suggests that either 200 mg or 600 mg mifepristone followed 36 to 48 hours later with 400 µg of oral misoprostol or 800 µg of vaginal misoprostol are effective for abortion at up to 49 days' gestation. Mifepristone affects not only a woman's reproductive system, but her cardiovascular, digestive and central nervous systems as well2. Patients who opt to have medical abortion should be counseled about the side effects of this combination regimen. The best known adverse effects are cramping and nausea, but other side effects such as vomiting, diarrhea, headache, dizziness and fever or chill occur in up to 15% of patients3. Two-thirds of the patients with cramp may need pain medication, but opiates are required in less than 2%. Most women will bleed for 13–15 days, and a few (less than 10%) will bleed for over 30 days4. The incidental findings of a huge adnexal mass with abnormally high serum CA125 levels in our case after medical abortion with oral mifepristone and misoprostol are unusual. The diagnosis was made by comparing pre- and postabortion ultrasonographic findings (indicating an acute lesion) and the appearance of the lesion with its elongated shape and fibrin-like contents. Pregnant women and gynecologists who decide to terminate an unwanted pregnancy with this technique need to familiarize themselves with its efficacy and complications. Acute hematosalpinx appears to be a rare complication, but one which should be borne in mind if there is lower abdominal pain after medical termination of pregnancy. S. K. Lin*, E. S. C. Ho*, Y. J. Chen*, * Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, 160, Section 3, Taichung-Kang Road, Taichung 407, Taiwan, R.O.C.

Double-orifice mitral valve with intact atrioventricular septum: An echocardiographic study with anatomic and functional considerations

We identified 18 patients with double-orifice mitral valve (DOMV) and intact atrioventricular (AV) septum out of 40,179 echocardiographic studies performed between 1997 and 2002 at Children's Hospital, Denver, CO. In this study we describe (1) the anatomic characteristics of the DOMV in the absence of AV septal defect, (2) the function of the mitral valve by spectral and color Doppler flow mapping, and (3) associated lesions. The topographic location of the orifices in the leaflets suggests possible embryologic mechanisms of DOMV. In this series, DOMV was most commonly associated with left-sided obstructive lesions (in 39% of patients). Spectral and color Doppler interrogation demonstrated a normal flow profile in most cases; only 2 patients had significant mitral regurgitation or stenosis. Therefore, due to the uncertain natural history of this lesion and the potential need for endocarditis prophylaxis, careful imaging of the mitral valve is recommended, particularly in the presence of left-sided obstructive lesions.

Preliminary investigation of the use of high frequency ultrasound imaging in the chick embryo

The purpose of this study was to investigate the feasibility of using high frequency ultrasound to study the chick embryo in a noninvasive and longitudinal fashion. A total of 10 SPF White Leghorn chick embryos (GDs 11-17; Hamburger and Hamilton stage 37-43) were consecutively examined with a GE Logiq 400 ProSeries ultrasound unit using an 11-MHz small parts ultrasound probe. Access for ultrasound visualization of the embryos was accomplished by opening a 2-3-cm window either in the air cell over the blunt end of the egg or laterally over the embryo-dependent side of the egg. Warmed ultrasound coupling gel was used for imaging, and thermal regulation was maintained with infant heel warmers. The ultrasound images were recorded directly on digital video using a Sony TRV 900 DV camcorder. The images were directly converted to jpeg and mjeg2 files for further analysis. Effective visualization of each embryo was possible on each day of the study period. The embryos were best visualized through the opening made in the air cell at the blunt end of the egg. The extent of the anatomic survey of the chick embryo was dependent upon the position of the embryo in the egg relative to the opening in the air cell. Doppler color flow mapping studies were obtained of the embryonic and extraembryonic circulation. This preliminary investigation clearly shows the feasibility of high frequency ultrasound imaging to study chick embryo development in a longitudinal and noninvasive fashion. Further studies are presently ongoing regarding earlier embryo development, as well as to determine the stability and dynamics of the methodology.

Comparison of Coronary Flow Velocities Between Patients with Obstructive and Nonobstructive Type Hypertrophic Cardiomyopathy: Noninvasive Assessment by Transthoracic Doppler Echocardiography

We aimed to compare coronary flow velocity (CFV) measurements of patients with nonobstructive (NHCM) and obstructive hypertrophic cardiomyopathy (HOCM) by using transthoracic Doppler echocardiography (TTDE). In 11 patients with NHCM and 26 with HOCM, CFV in the distal left anterior descending (LAD) coronary was measured by TTDE (3.5 MHz) under the guidance of color Doppler flow mapping in addition to standard 2D and Doppler echocardiography. The results were compared with 24 normal participants who had no evidence of cardiac disease. Peak diastolic velocity of LAD was also higher in NHCM and HOCM than controls (52 +/- 14 cm/sec and 54 +/- 20 cm/sec vs 41 +/- 11 cm/sec, respectively, P < 0.01). The analysis of systolic velocities revealed abnormal flow patterns in 16 (61%) patients with HOCM (12 systolic-reversal flow and 4 no systolic flow) and 6 (54%) (5 reversal flow and 1 zero flow) patients with NHCM (-11 +/- 30 cm/sec and -13 +/- 38 cm/sec, vs 24 +/- 9 cm/sec, respectively, P < 0.001). Linear regression analysis demonstrated no correlation between intraventricular pressure gradient and coronary flow velocities in HOCM patients. However, there were significant positive and negative correlations between septal thickness and diastolic and systolic velocities, respectively (r = 0.50, P < 0.002, and r =-0.43, P < 0.005). We conclude that the coronary flow velocity abnormalities are independent from the type of hypertrophic cardiomyopathy.

Clinical Evaluation of Color Doppler Imaging for the Differential Diagnosis of Thyroid Follicular Lesions

Ultrasonography (US) of the thyroid gland has recently proved to be a useful clinical diagnostic method, and the newly developed high-resolution US with a color Doppler flow mapping function can reveal fine details of the thyroid gland and the hemodynamic features of a thyroid neoplasm. US can yield a diagnostic accuracy of more than 90% for thyroid carcinoma, especially papillary carcinoma. However, neither conventional B-mode US imaging nor aspiration biopsy cytology has delivered satisfactory results for follicular carcinoma. The aim of this study was to evaluate the clinical usefulness of color Doppler imaging for the differential diagnosis of thyroid follicular lesions. A color Doppler scan was performed in 310 patients with a solitary cold nodule, and a combination of B-mode US and color Doppler findings, including tumor vascularity and results of a fast Fourier transform (FFT) analysis were used to create the following diagnostic grading system for differential diagnosis of follicular lesions: grade 1, benign follicular lesion [no color flow mapping (CFM) inside the nodule]; grade 2, benign peripheral type [CFM only in peripheral area, pulsatility index (PI) < 1.0]; grade 3, suspected follicular carcinoma (penetrating CFM, vascularity moderate); grade 4, follicular carcinoma (high-velocity penetrating CFM, PI = 1.0). All patients were subjected to surgical resection, and histologic examination was used to confirm the diagnosis. The grades of the 177 adenomatous nodules were as follows: grade 1, 46.9%; grade 2, 48.0%; grade 3, 5.1%; grade 4, 0%. The corresponding percentages for the 89 follicular adenomas were 16.9%, 49.4%, 30.3%, and 3.4%; and for the 44 follicular carcinomas they were 0%, 13.6%, 45.5%, and 40.9%. On the assumption that grade 1 and 2 lesions are benign and grade 3 and 4 lesions are malignant, 38 of the 44 follicular carcinomas and 227 of the 266 benign tumors had been accurately diagnosed, yielding a sensitivity of 88.9%, a specificity of 74.2%, and an accuracy of 81.0% for the grading system. Color Doppler imaging of 310 follicular tumors has revealed that high-velocity pulsatile blood flow penetrating the tumor is a characteristic finding of follicular carcinoma and is a new diagnostic criterion for performing color Doppler imaging. The differential diagnostic grading scores for color Doppler examinations and the results of FFT analysis demonstrate that US with the color Doppler function can play an important role in the differential diagnosis of thyroid tumors.