Resolution Ultrasonography Research Articles

In‐utero intervention for hypoplastic left heart syndrome — a perinatologist's perspective

.Today,whenHLHSisdiagnosedinthenewborn,or suspected by prenatal ultrasound studies, surgicalinterventions typically take one of two directions – eitherthe multistaged reconstruction pioneered by Norwood toenable single ventricle survival or cardiac transplantation.Compassionate care, although increasingly controversial,remains an option in some centers. Although increasingsurvival rates following both multi-staged surgery ortransplant are being reported, the nature of theseinterventions is such that these children remain at lifelongrisk for cardiac and neurologic morbidity.Consideration of HLHS as a candidate for

OC22.07: Magnetic resonance imaging of fetal cerebral lesions in severe twin–twin transfusion syndrome (TTTS): confrontation with ultrasound (US)

Monochorial twins are subjected to ten fold increased risk of cerebral palsy, compared to the general population. This increased risk in TTTS is mainly related to intertwin through placental vascular anastomosis, hemodynamic imbalance, as well as anemia and prematurity. We reviewed all cases referred for TTTS, treated by either serial amnioreduction, laser coagulation, intrauterine transfusions or undergoing cord coagulation of an abnormal co-twin. We selected specific examples of cerebral lesions, in order to show the respectives advantages and pitfalls of prenatal cerebral ultrasound examination and Mri in the evaluation of the fetal prognosis. Serial US examination of the fetal brain aimed at obtaining transfontanellar views in axial, coronal and sagittal section. Doppler pic systolic velocity was also measured in the midcerebral artery. Fetal Mri was performed at 1Tesla with single shot fast spin echo T2sequences in the three directions, gradient echo T1 and diffusion weighted imaging in axial section. Fetal Mri is particularly contributive from 3 weeks following the insult to the brain. Fetal Mri is particularly helpful in peripheric lesions. It does allow a more precise identification of hemorrhagic or clastic lesion. Small cystic lesion may be difficult to appreciate because of a poor spacial resolution when compared with US. Diffusion weighted imaging is feasible in utero, but their results are not homogeneous and need further studies. The most frequent lesions were clastic, including hydranencephalia, supratentorial necrosis, uni or bilateral, ischemia of the corpus callosum and lenticulostriate area, multicystic encephalomalacia, periventricular leucomalacia, intraventricular periventricular and parenchymal hemorrhage, ventriculomegaly and brain atrophy. Post natal evaluation were performed with serial transfontanellar high resolution US examination. Mri was sometimes performed when the correct gestational age approached full term, as well as at 4 month or one year of life. Pathological confrontation were performed in severes cases that led to perinatal death or termination of pregnancy. The prognosis of fetal cerebral lesion in the context of TTTS is mainly evaluated by ultrasound and Mri is contributive in the most subtle lesions. Transfontanellar fetal cerebral ultrasound examination is facilitated by a transvaginal route and should be serially performed. Its value is close to postnatal examination. Mri at 32 weeks can accurately depict abnormal maturation as well as small peripheric lesions and more clearly identify periventricular lesions detected with high resolution US specially in the workup of a ventricular dilatation. Such detailed and serial evaluation should allow for mainly subtle lesion with a good prognosis to be recognized only postnatally.

Spinal cord sonography in newborns: anatomy and diseases

Sonography of the spinal cord is a relatively recent acquisition that makes it possible to evaluate the content of the vertebral canal and study its pathologies. The aim of this study was to verify the reliability of ultrasound images by comparing them with magnetic resonance ones in healthy controls as well as in patients referred to us between 1991 and 2004. In this period, we studied 436 newborns: 88 without any suspicion of disease as normal controls, and 348 with suspected congenital diseases or in order to screen the children of diabetic mothers, a group that has shown an increased incidence of dysraphism. After explaining normal sonograms, we describe the pathological pictures observed in the 12 pathological cases in our series: conus hypomobility in five cases; lack of visualization of the conus medullaris in one case; and an enlarged ependymal canal in six cases. Four cases presented all three pathological conditions, and seven the association of two pathologies. All of these patients also underwent magnetic resonance imaging (MRI), which confirmed the ultrasound findings in four cases: three cases of enlarged ependymal canal and one of tethered cord hypomobility of the roots with an associated lipoma; the MRI findings were normal in the other seven cases. Sonography was highly specific but not very sensitive, because it is partially conditioned by patient collaboration. Nevertheless, subsequent MRI confirmed 37% of the suspected pathological cases. The ultrasound resolution of both normal and pathological spinal cord structures was particularly clear. The images were similar, easily comparable and often identical to the MRI results, although MRI was certainly more sensitive. The advantages of sonography are its non-invasiveness, low cost, the virtually ubiquitous availability of ultrasound equipment, the simplicity and rapidity of the examination, and its specificity. We believe that the indications for its use are lumbo-sacral skin alterations, neurological disorders caused by congenital malformations, traumas due to childbirth or a lumbar puncture, occult dysraphism, all of the compressive spinal cord neo-formations involving nerves, the dura mater and vertebral bone and joint structures, and the screening of the newborns of diabetic mothers.

A glomus tumour: classic signs without magnetic resonance imaging findings

A-36-year-old man presented with classic symptoms of a glomus tumour in the right index finger that failed to show on either ultrasound or high resolution magnetic resonance imaging (MRI). The radial finger pulp was explored despite the radiological findings and a glomus tumour 2 mm in size was excised. At follow-up the patient was pain-free. We conclude that exploration of an affected fingertip should be considered when there is a history of suspected glomus tumour even if MRI shows no sign of disease.

The Usefulness of High Resolution Ultrasonography in the Differentiation of Thyroid Nodule

Background: Fine needle aspiration (FNA) is regarded as the best procedure in the diagnosis of thyroid malignancies. However, the rate of false negative and indeterminate results are between 5~10 and 10~30%, respectively. Therefore, a new diagnostic tool to assist FNA is required. Recently, high resolution ultrasonography (US) has become a useful tool in the detection of malignant thyroid nodules. Therefore, the sonographic characteristics differentiating malignant from benign nodules were analyzed, and the usefulness of US in the diagnosis of thyroid malignancy assessed. Methods: Of the 212 patients that underwent surgery due to a thyroid nodule, at the Daegu Catholic University Hospital between January 2002 and June 2004, and 181 patients (199 nodules) who underwent high resolution US examination before surgery, were included in this study. The characteristics of the sonographic parameters, such as depth/width ratio, shape, margin, structure, sponge sign, calcification and halo, and the homogeneity and echogenicity of the solid component and invasion, were observed. Results: In a univariate analysis of the nonfollicular neoplasms, the depth/width ratio, shape, margin, structure, calcification and halo, and the homogeneity and echogenicity of the solid component were found to be significant parameters. The “sponge sign”, a new parameter suggested by us, was found only in benign nodules. In a multiple logistic regression analysis, only the depth/width ratio, shape, presence of calcification and echogenicity of the solid component were significant parameters. According to the results of the multiple logistic regression analysis, the point and estimate of each characteristic of the significant parameters were found, and a formula for calculating a score for the prediction of malignancy computed. At a score of 0.44, the sensitivity and specificity of US were 85.9 and 88.7%, respectively. In a univariate analysis of follicular neop-lasms, the shape, calcification and echogenicity were found to be significant parameters. Conclusion: It was conclude that high resolution US is a very useful tool in the differentiation of benign and malignant nodules, especially in nonfollicular neoplasms. It is also suggested that the “sponge sign” might be used as a strong indicator for the confirmation of benign nodules (J Kor Soc Endocrinol 20:242～251, 2005).

Characterisation of low, medium and high responders following FSH stimulation prior to ultrasound-guided transvaginal oocyte retrieval in cows

In human IVF, the concept of ‘low responders’ is well known and generally defined as women with poor-response to gonadotrophin stimulation in a previous induction cycle. The objective of this retrospective study is to describe and characterise the concepts of ‘low-, medium-, and high-response’ and ‘low, medium, and high responders’ in bovine-assisted reproduction by analysing the OPU–IVF results obtained following 665 gonadotrophin-stimulated sessions conducted in 112 animals, nearly all of which were previously unsuccessful in traditional multiple ovulation and embryo transfer (MOET) programs. They were submitted to OPU and IVP between 1999 and 2003. In reference to these 665 OPU sessions, categories of response were defined based on the overall mean ± S.D. follicles aspirated and COC obtained i.e., for follicles 14.7 ± 9.8 and for COCs 11.7 ± 8.1. So arbitrary cut-off values to define the categories of sessions were for follicles 5 and 25, and for COC 4 and 20. The three categories for follicles punctured in one session were therefore follicle low-response (FLR) ≤ 5 follicles, follicle medium-response (FMR) 6–24 follicles or follicle high-response (FHR) ≥ 25 follicles and for COCs recovered in one session COC low-response (CLR) ≤ 4 COC, COC medium-response (CMR) 5–19 COC or COC high-response (CHR) ≥ 20 COC. In addition, four categories of animals were also defined: (1) a low responder animal (LRA) had at least one OPU session in which FLR and CLR were observed (genuine low-response, see Section 3); these animals did not have any high-response sessions, (2) a medium responder animal (MeRA) had only medium-responses, (3) a high responder animal (HRA) had at least one OPU session in which FHR and CHR were observed; these animals did not have any low-response sessions, and (4) mixed responder animals (MiRA) had both low and high-responses. Finally, we distinguished biological (animals) and technical (recovery rate and ultrasound resolution) causes of response differences. In ‘low, high, medium and mixed reponders,’ different results were obtained ( p < 0.05): mean follicle numbers (8.8 ± 4.8 a, 22.4 ± 10.5 c, 13.2 ± 5.2 b,15.1 ± 10.2 d), COC numbers (6.3 ± 3.9 a, 18.5 ± 8.2 c, 10.4 ± 4 b, 12.0 ± 8.3 d), embryo numbers (1.8 ± 2.1 a, 5.6 ± 4.9 c, 2.5 ± 2.7 b, 3.5 ± 3.8 d) and also for recovery rate (72% a, 83% b,79%, 79%) and percentage embryo development (29%, 30% a, 24% b, 29%). In conclusion, the results of this study demonstrate that variability in OPU results has technical (ultrasound resolution and recovery rate) as well as biological (animal) aspects. Selection of animals with extreme (high or low) follicle and COC production results allows us to distinguish three populations: ‘low, medium, and high responders’ to FSH stimulation.

Doppler sonography in rheumatology

The importance of ultrasonography in rheumatology has increased dramatically within the last few years both with regard to clinical practice and to research. High-resolution colour Doppler ultrasound equipment is, to date, widely available. Colour and power Doppler studies of intra-articular and peritendinous blood flow allow an estimation of the inflammatory activity and aid in distinguishing anatomical structures. Contrast agent increases the ability of ultrasonography to detect even minor perfusion. These findings have a practical clinical impact on the management of inflammatory rheumatic diseases. The resolution of ultrasonography is superior to that of magnetic resonance imaging (MRI) and computed tomography (CT) with regard to superficial anatomical structures. Furthermore, ultrasonography can depict the artery wall in contrast to angiography. In temporal arteritis and Takayasu's arteritis, ultrasonography depicts characteristic, homogenous wall thickening, stenoses and acute occlusions. These pathologies resolve quickly with treatment in the temporal arteries and much more slowly in larger arteries.

Simulation study of effects of speed of sound and attenuation on ultrasound lateral resolution

Experiments have shown that the lateral profile of a point target measured with a clinical ultrasound scanner is wider when the target is embedded in a urethane phantom than when it is in a traditional gel phantom. The behavior has been attributed to the low speed of sound in the urethane material, with the possibility that some of the broadening is caused by increased attenuation in this material. In this paper we apply a computer simulation model to study this behavior. Lateral beam profiles modeled for targets within a medium having a speed of sound and an attenuation matching that of urethane are compared with profiles for targets in a water-based gel. Simulations yield results that agree qualitatively with published experimental results. The lateral profile broadening in urethane is caused by the 6 % mismatch between speed of sound in this material and the speed of sound assumed in the receive focusing and beam forming. Attenuation plays a lesser role than the mismatch of the speed of sound. (E-mail: jazagzeb@facstaff.wisc.edu)

Detection of Single Muscle Fiber Movements (Fibrations) in SMA Type I by High Resolution Ultrasound

Introduction: Movements of a group of muscle fibers innervated by a single motor unit (fasciculations) are detected by clinical inspection, electromyography and ultrasound. Up to now movements of single muscle fibers are realized just by electromyography and can be called fibrillations. We tried to analyze single muscle fibers by a new ultrasound technique and that was when we saw movements of single muscle fibers. Method: We examined three infants with spinal muscular atrophy (SMA) type I and typical deletion in the survival motor neuron (SMN) gene and ten children with other neuromuscular diseases by means of a high resolution ultrasound system (HDI 5000 and 15–7MHz-Compact-Linear-Broadband-Scanhead from Advanced Technology Laboratories, Washington, USA). Results: We found only in the three infants with SMA type I the well-known rhythmic and synchronous movements of groups of muscle fibers (fasciculations) as well as a turmoil of arrhythmic and asynchronous twitches of single muscle fibers. Conclusions: By means of high resolution ultrasound it was possible to detect movements of even single muscle fibers. The turmoil of single muscle fibers was very impressive. But we do not think the term fibrillations is right. Fibril is the diminutive form of fiber and myofibrils are the contractile filaments of muscle fibers. That is why we suggest the term fibrations. This term is derived from fiber, because we are not able to see movements of myofibrils but rather of single muscle fibers by the new ultrasound technique. Acknowledgements: We thank the local group of the German Society for Patients with Muscle Diseases (Deutsche Gesellschaft für Muskelkranke e.V.) in Elmshorn for financial support and we thank the departments for gynecology and pediopathology of Kiel University Hospital for technical support.

Modern imaging of Crohn's disease using bowel ultrasound.

Technological advancement of ultrasound (US) equipments and understanding of bowel appearances with high resolution US during the last decade has led to consideration of this imaging procedure as an important tool for inflammatory bowel diseases assessment. In particular, Crohn's disease (CD) for its pathologic characteristics (that is, inflammatory infiltration of the entire bowel wall with possible extension to the surrounding mesentery) is the disease entity which has mainly taken advantage from this non-invasive, radiation-free technique. Beside correctly defining anatomic location and extension of CD lesions within the bowel in the majority of cases, US also shows perigut abnormalities and may demonstrate complications such as fistulas and abscesses. With the help of Power Doppler function, some additional information may be obtained about the local activity of the disease which is particularly useful in the presence of strictures. New US technologies (such as those using intravenous bolus contrast agents or oral nonabsorbable anechoic solutions) may further improve diagnostic capability of US in this context, thus probably revolutioning the diagnostic approach to this disease in the near future, particularly during follow-up in CD of the small bowel.

P3-33 Real-time 3-D Ultrasound High Resolution Medical Imaging System with a Sensor Array and a Reflector

P3-33 Real-time 3-D Ultrasound High Resolution Medical Imaging System with a Sensor Array and a Reflector

Book review

Book review

Effect of alcohol consumption on endothelial function in men with coronary artery disease

An inverse relationship between moderate alcohol consumption and coronary artery disease (CAD) has been observed in several epidemiologic studies. Whether improvement of endothelial function is involved in this beneficial effect is unknown. We investigated endothelial function of the brachial artery in 108 men with CAD, 54 of whom consumed alcohol on at least 1 day per week. Brachial artery diameter responses to hyperemic flow (FMD) and to administration of nitroglycerin (NTG) spray were measured using high- resolution ultrasonography. Coronary risk factors and hyperuricemia were present more frequently among drinkers, who also had higher concentrations of triglyceride and apolipoproteins C2, C3, and E. FMD was greater in drinkers ( P<0.0001), while NTG-induced dilation was not. Multiple regression analysis showed alcohol consumption to be one of the factors favorably influencing FMD. These findings suggest that alcohol consumption may improve endothelial function in men with CAD.

Heart activity visualization in embryos with crown‐rump length shorter than 5 mm

Introduction: In the past, heart activity was only visualized by ultrasound in embryos with a crown‐rump length (CRL) of 5 mm or more. When CRL was shorter than 5 mm, non‐visualization of heart activity was considered normal. However, improvement in ultrasound equipment resolution has made it possible to diagnose viability in embryos with CRL as small as 2 mm.Objective: The aims of this study were to determine: (a) how often heart activity is visualized in embryos with CRL between 2 and 5 mm; (b) outcome when CRL is shorter than 5 mm and heart activity is not visualized.Methods: Presence or absence of heart activity was examined in embryos with CRL between 2 and 5 mm by vaginal ultrasound (Medison Model Voluson 530 and Aloka Model 1700), 4–7 MHz; B‐ and M‐mode). Follow up scans were carried out one‐week later when the initial scan did not demonstrate heart activity.Results: Two hundred and forty‐four embryos were examined and heart activity was demonstrated in 210 (86%) cases. Follow up scans demonstrated heart activity in six (17.5%) of the 34 embryos in which heart activity was not initially visualized.Conclusion: This study has demonstrated that visualization of heart activity is possible in most embryos with CRL between 2 and 5 mm nowadays. Non‐visualization at this stage is associated with embryonic demise in about 80% of cases.

A thin film phantom for blood flow simulation and Doppler test.

The thin film phantom is a new type of ultrasound resolution test object. It consists of a thin planar substrate that is acoustically matched to the surrounding media. Precisely located scatterers on the surface of the substrate generate echo signals. The patterning of scatterers on the substrate allows echogenicity to be controlled as a function of position, which enables the production of a test object with highly reproducible and controllable scattering characteristics. We show that by vibrating the substrate in a suitable manner, an echo signal may be generated that simulates bi-directional flow. We demonstrate that a vibration of low amplitude at frequency f0 produces a Doppler spectral signal at f0 and -f0, within the limits of aliasing. Furthermore, by driving the film with a bandlimited noise signal, we illustrate how a velocity distribution may be simulated. A time-varying flow velocity may be simulated by varying the noise bandwidth with time. Finally, using this technique, we demonstrate a system that simulates an arterial flow pattern, including its characteristic velocity distribution in forward and reverse directions simultaneously.

WS01‐04Fetal lung abnormalities a spectrum of disease: reclassification system based on embryology, 2‐D and Doppler ultrasound

ObjectiveFetal lung anomalies are traditionally classified into Congenital Cystic Adenomatoid Malformation (CCAM), and Pulmonary Sequestration (PS). During last years we have detected several cases who presented with bizarre and overlapping findings which could not be fitted into this usual classification. We therefore suggest a new approach for classification based on embryology, 2‐D and Doppler ultrasound.MethodDuring 5‐year period, patients with fetal lung lesions who were referred for detailed ultrasound evaluation at the Sheba Medical Center from the data base of this study. All cases were analyzed by 2‐D ultrasound and high resolution Power Doppler technology and were classified into three major categories: I Agenesis of lung; II Lung lesion with normal vascular supply: IIa solid, IIb cystic, IIc mixed; III Lung Lesion with abnormal vascular supply: IIIa chest, IIIb abdomen, IIIc thoracoabdomial. Medical files, natural history and neonatal follow‐up were recorded.ResultsTwenty‐one fetuses were recruited, two fetuses were detected in group one, 14 in group II of normal vascular supply, and five in group III abnormal lung with abnormal vascular involvement.ConclusionsBased on embryology and ultrasound a new classification system is introduced.

Ultrasound assessment of large joint amyloidosis in haemodialysis

SUMMARY:Dialysis‐related amyloidosis (DRA), associated with beta‐2 microglobulin deposition, is a common cause of morbidity in patients with renal failure undergoing chronic dialysis. The non‐invasive diagnosis of DRA in its early stages is difficult. High resolution ultrasound (US) was used to examine the shoulder, hip and knee joints of 25 chronic haemodialysis patients, and features distinctive of DRA were determined. Distinctive US features were associated with increased total duration of dialysis (15 ± 5 vs 4 ± 2 years), carpal tunnel syndrome (9/10 cases) and shoulder joint discomfort (19 vs three joints). These features include altered rotator cuff echogenicity (hyperechoic and hypoechoic areas; 20/48 joints), hypoechoic material in the biceps sheath (16/48), erosions of bone (15/48) and reduced biceps tendon fibril echogenicity (12/48). These changes are unique in the experience of the current authors, but histological proof that they are definitely the result of DRA has not yet been possible. Tears of the rotator cuff tendons (14/50) were not consistently associated with symptoms (7/14). Tendon thickness was also increased (as has been described previously). The hip capsule thickness was increased in patients with signs of DRA in the shoulder, but no specific changes in texture were seen. Asymptomatic knee joint effusions were present in 40/50 joints (80%). These features detectable on high resolution US allow the non‐invasive early detection of DRA and are useful in the diagnosis and management of this condition.

Accuracy of in-vitro volume estimation of small structures using three-dimensional ultrasound

We describe an ultrasound probe for three-dimensional transvaginal imaging. The transducer was an annular array with a center frequency of 7.5 MHz which was rotated with an internal stepper motor. The probe had no external moving parts, and the total volume covered by a full rotation defined a half sphere. The raw digital data from the scanner were transferred to an external PC for three-dimensional reconstruction. We evaluated the three-dimensional imaging system by measuring the volumes of phantoms (range 24.8–3362.5 mm 3) in a water tank, and found good correlation with true volumes (two observers’ measurements gave a linear regression with a slope of 1.010 and R 2 = 0.993, and a slope of 0.956 and R 2 = 0.993, respectively). The size of the point-spread function was used in the calculations to eliminate the effect of under- or overestimation due to the limited ultrasound beam resolution. An example of data acquisition, volume estimation and imaging of an embryo less than 8 weeks old in vivo with the brain cavities and body is given. We conclude that the three-dimensional reconstruction and volume estimation were accurate and repeatable.

Increased renal resistive index in patients with essential hypertension: a marker of target organ damage.

Increased renal resistance detected by ultrasound (US) Doppler has been reported in severe essential hypertension (EH) and recently was shown to correlate with the degree of renal impairment in hypertensive patients with chronic renal failure. However, the pathophysiological significance of this finding is still controversial. In a group of 211 untreated patients with EH, we evaluated renal resistive index (RI) by US Doppler of interlobar arteries and early signs of target organ damage (TOD). Albuminuria was measured as the albumin to creatinine ratio (ACR) in three non-consecutive first morning urine samples. Left ventricular mass was evaluated by M-B mode echocardiography, and carotid wall thickness (IMT) by high resolution US scan. RI was positively correlated with age (r=0.25, P=0.003) and systolic blood pressure (SBP) (r=0.2, P=0.02) and with signs of early TOD, namely ACR (r=0.22, P=0.01) and IMT (r=0.17, P<0.05), and inversely correlated with renal volume (r=-0.22, P=0.01) and diastolic blood pressure (r=-0.23, P=0.006). Multiple linear regression analysis demonstrated that age, gender, ACR and SBP independently influence RI and together account for approximately 20% of its variations (F=8.153, P<0.0001). When clinical data were analysed according to the degree of RI, the patients in the top quartile were found to be older (P<0.05) and with higher SBP (P<0.05) as well as early signs of TOD, namely increased ACR (P<0.002) and IMT (P<0.005 by ANOVA), despite similar body mass index, uric acid, fasting blood glucose, lipid profile and duration of hypertension. Furthermore, patients with higher RI showed a significantly higher prevalence of microalbuminuria (13 vs 12 vs 3 vs 33% chi2=11.72, P=0.008) and left ventricular hypertrophy (40 vs 43 vs 32 vs 60%, chi2=9.25, P<0.05). Increased RI is associated with early signs of TOD in EH and could be a marker of intrarenal atherosclerosis.

The Use of Nuchal Lucency as a Screening Tool in First Tritester Sonography

Improved ultrasound resolution and continuing attempts to detect congenital abnormalities and chromosomal aberrations in early pregnancy have led to the use of nuchal lucency as a marker for such conditions in the first trimester. Current research has shown the importance of increased nuchal lucency (greater than 3 mm) as an identifying risk marker for aneuploidy and, in the presence of normal karyotype, additional anatomic anomalies.