Conventional Doppler Sonography Research Articles

Assessment of focal liver lesions in non-cirrhotic liver – expert opinion statement by the Swiss Association for the Study of the Liver and the Swiss Society of Gastroenterology

Focal liver lesions are common, with a prevalence up to 20%. The lesions must be evaluated in context of risk factors associated with malignancy. Risk factors include age >40 years, known current or past malignancy, presence of liver cirrhosis or chronic liver disease (i.e. suspected by elevated liver elastography measurement ≥8 kPa or FIB-4 score ≥1.3), unintentional weight loss, fever or night sweats, newly detected focal liver lesions, documented growth of focal liver lesions, current or past use of androgens (e.g. testosterone, oxymetholone, danazol), increased serum tumour markers (i.e. alpha-fetoprotein, carbohydrate antigen 19-9 [CA19-9], carcinoembryonic antigen [CEA]) and family history of malignancy. In patients without risk factors of malignancy, regional (non-)fatty changes, simple liver cysts and typical haemangiomas can be diagnosed by conventional ultrasound (without contrast). Conventional ultrasound Doppler is recommended to rule out vascular malformations such as portosystemic shunts. In all other cases of focal liver lesions, contrast-enhanced imaging is indicated for differentiation in benign and malignant dignity. Contrast-enhanced ultrasound (CEUS) as a first diagnostic step and contrast-enhanced magnetic resonance imaging (MRI) are accurate tests to diagnose haemangioma and focal nodular hyperplasia. Hepatocellular adenoma is diagnosed by contrast-enhanced MRI and/or histology. “Wash out” on CEUS is highly suspicious for a malignant focal liver lesion. Additional investigations aimed at identifying the primary tumour, as well as staging-computed tomography, MRI and/or histology may be necessary and should be decided on a case-by-case basis. A biopsy of focal liver lesions is indicated in cases of unclear dignity, malignant aspect and focal liver lesions of unclear origin as well as for guiding surgical and oncological management.

Analysis for Improvement of Doppler Tomography Imaging of Objects Scattering Continuous Ultrasonic Waves

The paper describes an innovative ultrasound imaging method called Doppler Tomography (DT), otherwise known as Continuous Wave Ultrasonic Tomography (CWUT). Thanks to this method, it is possible to image the tissue cross-section in vivo using a simple two-transducer ultrasonic probe and using the Doppler effect. It should be noted that DT significantly differs from the conventional ultrasound Doppler method of measuring blood flow velocity. The main difference is that when measuring blood flow, we receive information with an image of the velocity distribution in a given blood vessel (Nowicki, 1995), while DT allows us to obtain a cross-sectional image of stationary tissue structure. In the conventional method, the probe remains stationary, while in the DT method, the probe moves and the examined tissue remains stationary. This paper presents a method of image reconstruction using the DT method. First, the basic principle of correlation of generated Doppler frequencies with the location of inclusions from which they originate is explained. Then the exact process and algorithm in this method are presented. Finally, the impact of several key parameters on imaging quality is examined. As a result, the conclusions of the research allow to improve the image reconstruction process using the DT method.

Comparison of conventional, doppler and contrast-enhanced ultrasonography in differential diagnosis of ovarian masses: a systematic review and meta-analysis

ObjectivesTo assess the value of conventional, Doppler and contrast-enhanced ultrasonography (CEUS) (conventional ultrasonography (US), Doppler US and CEUS) for diagnosing ovarian cancer.DesignSystematic review and meta-analysis.Data sourcesPubMed, Embase and the Cochrane...

Feasibility of Ultrafast Doppler technique for cranial ultrasound in neonates.

The aim of this study was to compare the performances of Ultrafast Doppler ultrasound (US) with classic Doppler US, for cranial ultrasound in neonates. We measured the peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive index (RI) of the anterior cerebral artery (ACA), middle cerebral artery (MCA) and posterior cerebral artery (PCA) in neonates using both conventional and Ultrafast Doppler US and acquisition times were compared. Distal ACA branches were assessed with Ultrafast Doppler US. A total of 138 neonates were included. The PSV and EDV of the cranial arteries were comparable between the two Doppler methods (PSV, 64.6-85.5 cm/s vs. 63.4-84.1 cm/s, p=0.100-0.510; EDV, 19.1-26.5 cm/s vs. 17.8-24.2 cm/s, p=0.100-0.981). The RIs of the ACA and PCA were not significantly different (0.69-0.73 vs 0.68-0.74, p=0.174-0.810). Ultrafast Doppler US required shorter acquisition times than conventional Doppler US (6.7 s vs. 11.0 s, p=0.003). The PSV and EDV of the distal ACA were higher than the proximal ACA (20.1-63.3 cm/s vs. 9.4-36.7, p<0.001) although the RI was similar (0.69 vs. 0.68, p=0.251). Ultrafast Doppler US provides comparable values to conventional Doppler US with shorter acquisition times. This novel imaging technique provides quantitative information and is suitable for distal cranial artery evaluation.

Seeing the Unseen: Evaluating Testicular Vascularity in Neonates by Using the Superb Microvascular Imaging Ultrasound Technique.

To evaluate testicular vascularity in neonates by using the novel Superb Microvascular Imaging (SMI; Toshiba Medical Systems Corporation, Tokyo, Japan) ultrasound (US) technique and to compare this technique to conventional Doppler US techniques. A total of 140 healthy neonates between 2 and 60 days old who were admitted for routine screening were included in the study. However, in 9 cases, the Doppler study could not be completed. In the remaining 131 cases, color Doppler imaging (CDI), power Doppler imaging (PDI), Advanced Dynamic Flow (ADF; Toshiba Medical Systems), and monochrome SMI (mSMI) techniques were performed on a single representative testicle. Real-time cine images were captured for 5 to 10 seconds for each technique by using a high-frequency (7.2-14-MHz) linear transducer. The images were evaluated by 3 observers using a grading system to quantify the degree of vascularity and artifact interference. A total of 131 testicles (74 right and 57 left) were evaluated, and vascularity was shown in 110 (84%) testicles with CDI, 109 (83%) with PDI, 94 (72%) with ADF, and 128 (98%) with mSMI by the consensus of all observers. The Doppler techniques were ranked from highest to lowest in the following order based on the degree of vascularity detected: mSMI > PDI > CDI > ADF (P < .001). Based on the presence of artifacts, the Doppler techniques were ranked as follows from high to low: ADF > CDI > PDI > mSMI (P < .001). Superb Microvascular Imaging is a promising US technique that appears to detect testis vascularity better than conventional Doppler US techniques; however, further research is needed to support the results of this study.

In Vivo Visualization of Vasculature in Adult Zebrafish by Using High-Frequency Ultrafast Ultrasound Imaging.

Zebrafish has been recently considered an ideal vertebrate for studying developmental biology, genetics, particularly for modeling tumorigenesis, angiogenesis, and regeneration in vivo. However, when a zebrafish matures completely, its body loses transparency, thus making conventional optical imaging techniques difficult for imaging internal anatomy and vasculature. Acoustic wave penetration outperforms optical methods, high-frequency (>30 MHz) ultrasound (HFUS) was consequently an alternative imaging modality for adult zebrafish imaging, particularly for echocardiography However, visualizing peripheral vessels in a zebrafish by using conventional HFUS is still difficult. In the present study, high-frequency micro-Doppler imaging (HFμDI) based on ultrafast ultrasound imaging was proposed for zebrafish dorsal vascular mapping in vivo. HFμDI uses a 40-MHz ultrasound transducer, which is an ultrafast ultrasound imaging technology with the highest frequency available currently. Blood flow signals were extracted using an eigen-based clutter filter with different settings. Experiments were performed on an 8-month-old wild-type AB-line adult zebrafish. Blood vessels, including intersegmental vessels, parachordal vessel, dorsal longitudinal anastomotic vessel, and dorsal aorta, from the dorsal side of the zebrafish were clearly observed in two-dimensional (2-D) and 3-D HFμDI. The maximum image depth of HFμDI and the minimal diameter of vessel can be detected were 4 mm and 36μm, respectively; they were determined without any use of microbubbles. The maximum flow velocity range was approximately 3-4 mm/s on the dorsal vessels of the adult zebrafish. Compared with conventional ultrasound Doppler imaging, HFμDI exhibited superior small vessel imaging.

Experience of Using Shear Wave Elastography Imaging in Superficial Venous Insufficiency of the Lower Extremity.

We investigated the effectiveness of shear wave elastography (SWE) in patients with lower extremity superficial venous insufficiency (VI). A total of 138 symptomatic patients, 51 asymptomatic volunteers, and a total of 359 lower extremities (257 symptomatic, 102 asymptomatic) were examined. All participants underwent Doppler ultrasound (US) evaluation to determine VI and SWE measurements performed by manually drawing vein wall and perivenous tissue with free region of interest at the great saphenous vein (GSV) and small saphenous vein (SSV). The GSV, SSV diameter, VI, and volume flow of reflux were compared with the SWE values. The SWE values of the symptomatic group for GSV and SSV were significantly higher than those of the asymptomatic control group regardless of whether VI was detected by Doppler US (P < 0.001). There was a statistically significant increase in SWE values for the symptomatic group who were diagnosed as having reflux in GSV and SSV (P < 0.001). A significant positive correlation between increased GSV, SSV diameter, and SWE values was seen (P < 0.001). Venous insufficiency can be diagnosed with a 84.7% sensitivity and 84.2% specificity when 2655 m/s was designated as cutoff value, and with a 85.4% sensitivity and 84.2% specificity when 22,350 kPa was designated as the cutoff value in GSV. Venous insufficiency can be diagnosed with a 84.3% sensitivity and 82.4% specificity when 2845 m/s was designated as cutoff value, and with a 85.7% sensitivity and 84.4% specificity when 27,100 kPa was designated as the cutoff value in SSV. Shear wave elastography may be used effectively in addition to conventional Doppler US examination in diagnosing and following VI.

Contrast-enhanced ultrasound for the evaluation of hepatic artery occlusion after liver transplantation

Introduction:Vascular complications after liver transplantation remain a major threat to the survival of recipients.HAT is a major cause of graft loss and patient mortality, with an incidence between 3% to 8% in transplant recipients.Early detection of HAT is critical because urgent revascularization is required to avoid severe graft loss. Although ultrasound is the preferred first-line imaging modality in patients with suspected HAT, the accuracy and positive predictive value of HAT on Doppler US are reported to be low. Moreover, Doppler examination of the hepatic vasculature is time consuming and requires a high level of operator skill. Conventional angiography remains the gold standard for diagnosis. Recently, contrast-enhanced ultrasound (CEUS) has begun providing real-time angiographic-like images of vessels at bed side and allowing the accurate diagnosis of arterial diseases such as hepatic artery thrombosis. The purpose of this study was to evaluate the efficacy of CEUS in detecting HAT after liver transplantation: Materials and Methods: This is a retrospective data of the medical records of patients undergoing Liver transplantation in the Osmania General Hospital, Hyderabad between 2016 to 2018. Status of hepatic vascular assessment following liver transplantation done by conventional Doppler Ultra sonography and Contrast Enhanced Ultrasonography tests were obtained from registries of medical records. Results:23 cases of post Liver transplantation aged between 4years and 58 years, with a median age of 30 years were included in the analysis. There were 20 males and 3 females. 14 patients underwent DDLT, 7 patients underwent LDLT, 1underwent split Liver transplantation and another 1 patient underwent Auto liver transplantation. Doppler US was inconclusive regarding patency of the hepatic artery (HA) circulation in 5 (21.7 %) of 23 transplantations. CEUS was performed in these 5 patients and detected HA thrombosis (HAT) in 2 cases and patent HA in 3 transplants. These 5 Transplants were confirmed by CT Angiography /conventional Angiography. In the subset of transplantations examined with CEUS, the sensitivity, specificity and accuracy of CEUS were 100%. CEUS was done at bedside without any Radiation and Nephro toxicity. In approximately 21.7% of cases, conventional Doppler US did not provide sufficient visualization of the HA after liver transplantation. In these cases, correct diagnosis was achieved by supplementary CEUS. Conclusion:CEUS may be a new approach for early diagnosis of postoperative vascular complications after Liver Transplantation, and it can be performed at the bedside. It is safe will not cause any nephron toxicity and Radiation. CEUS is a fast, non-ionizing imaging modality for the initial exclusion of vascular complications after liver transplantation. CEUS shows a high specificity and PPV in the detection of vascular complications. In unclear cases CT still is considered as the gold standard

Comparison of Two Devices for Intraoperative Portal Venous Flow Measurement in Living-Donor Liver Transplantation: Transit Time Ultrasound and Conventional Doppler Ultrasound

BackgroundIntraoperative portal venous flow measurement provides surgeons with instant guidance for portal flow modulation during living-donor liver transplantation (LDLT). In this study, we compared the agreement of portal flow measurement obtained by 2 devices: transit time ultrasound (TTU) and conventional Doppler ultrasound (CDU). MethodsFifty-four recipients of LDLT underwent intraoperative measurement of portal flow after completion of vascular anastomosis of the implanted partial liver graft. Both TTU and CDU were used concurrently. Agreement of TTU and CDU was assessed by intraclass correlation coefficient using a model of 2-way random effects, absolute agreement, and single measurement. A Bland-Altman plot was applied to assess the variability between the 2 devices. ResultsThe mean, median, and range of portal venous flow was 1456, 1418, and 117 to 2776 mL/min according to TTU; and 1564, 1566, and 119 to 3216 mL/min according to CDU. The intraclass correlation coefficient of portal venous flow between TTU and CDU was 0.68 (95% confidence interval, 0.51–0.80). The Bland-Altman plots revealed an average variation of 4.8% between TTU and CDU but with a rather wide 95% confidence interval of variation ranging from −57.7% to 67.4%. ConclusionsIntraoperative TTU and CDU showed moderate agreement in portal flow measurement. However, a relatively wide range of variation exists between TTU and CDU, indicating that data obtained from the 2 devices may not be interchangeable.

Qualitative and quantitative contrast-enhanced ultrasonography for the characterisation of non-palpable testicular tumours

To assess the diagnostic performance of conventional ultrasound (US) and contrast-enhanced ultrasonography (CEUS) in the differential diagnosis of non-palpable intratesticular tumours. The local ethics review board approved the protocol, and all of the patients provided written informed consent. Between December 2011 and February 2014, men with non-palpable testicular tumours and normal tumour markers who were referred for surgery were included. The tumours were analysed by conventional US, including B-mode and colour Doppler US (CDUS) as well as by CEUS. Morphological aspects and qualitative and quantitative CEUS criteria, based on visual enhancement and time-intensity curves, were assessed for each lesion. Forty patients were ultimately included. Based on histopathological results, the tumours were classified into three groups: benign tumours (n=16), malignant tumours (n=15), and burned-out tumours (n=9). In B-mode, the morphological aspects were significantly different between benign and malignant tumours (p-values from 0.0002 to 0.008). Qualitative and quantitative analyses of the CEUS images revealed that burned-out tumours exhibited significantly less enhancement than malignant and benign tumours: in burned-out tumours, time-intensity curves were flat, whereas in both benign and malignant tumours the curves had a bell-shaped pattern. All intensity parameters were lower for burned-out tumours compared to benign and malignant tumours (p-value from 0.0001 to 0.026). Both benign and malignant tumours enhanced strongly, however, and no significant difference between the two was noted (p-value from 0.0721 to 0.0953). Unlike conventional US, which enable benign lesions to be differentiated from malignant or burned-out tumours, CEUS failed to enabled differentiation between benign lesions and malignant vascularised testicular tumours. CEUS appears to have the potential, however, to differentiate burned-out tumours from vascularised testicular tumours.

Clinical application of anterolateral thigh polyfoliate perforator flap for vascular pedicle protection

To evaluate the effectiveness of anterolateral thigh polyfoliate perforator flap plus pedicle with one foliate flap for repairing extremities soft tissue defect. Between January 2014 and January 2017, 24 patients with extremities soft tissue defects were treated by anterolateral thigh polyfoliate perforator flap plus pedicle with one foliate flap. There were 15 males and 9 females, with a median age of 33.5 years (range, 5-64 years). Wounds located in upper limb in 8 cases, complicated with radial styloid fracture in 1 case, extensor tendon exposure in 3 cases, and brachioradialis muscle tendon exposed in 1 case. Wounds located in lower extremity in 16 cases, complicated with calcaneal or metatarsal, phalangeal fractures in 4 cases, Achilles tendon departure in 1 case, toe long extensor tendon and flexor digitorum longus tendon exposed in 8 cases. The wound area ranged from 8 cm×5 cm to 18 cm×12 cm. According to wound size, anterolateral thigh perforators were detected by conventional ultrasound Doppler (2-5 perforators). The irregular wounds were decomposed into multiple parts and the leaf number (2-4 leaves) of polyfoliate flap depended on the part number of the wound. The flap area ranged from 9 cm×6 cm to 20 cm×14 cm, and the largest area of single leaf was 24 cm×6 cm. The vascular pedicle length ranged from 7 cm to 12 cm. The foliate flap area with protecting pedicle ranged from 5 cm×3 cm to 7 cm×5 cm. All the flaps survived, and no vascular crisis occurred. All the patients were followed up 2-28 months (mean, 9 months). Sinus occurred in 1 case of calcaneal fracture after flap repair, and the sinus was healed after 3 months by conventional dressing. All the flaps were thin and had a good texture. Healing of soft tissue was found in 5 patients with fracture. The wrist and ankle plantar flexion and dorsiflexion function of recipient site were normal in all patients. It is safe and reliable to repair the extremities soft tissue defect with anterolateral thigh polyfoliate perforator flap plus pedicle with one foliate flap. And it is one of the ways to reduce the vascular crisis of the anterolateral thigh free perforator flap.

Intraoperative contrast-enhanced ultrasonography for microcirculatory evaluation in rhesus monkey with spinal cord injury.

This study tried to quantify spinal cord perfusion by using contrast-enhanced ultrasound (CEUS) in rhesus monkey models with acute spinal cord injury. Acute spinal cord perfusion after injury was detected by CEUS, coupling with conventional ultrasound (US) and Color Doppler US (CDFI). Time-intensity curves and perfusion parameters were obtained by autotracking contrast quantification (ACQ) software in the epicenter and adjacent regions of injury, respectively. Neurological and histological examinations were performed to confirm the severity of injury. US revealed spinal cords were hypoechoic and homogeneous, whereas dura maters, pia maters, and cerebral aqueducts were hyperechoic. After spinal cord contusion, the injured spinal cord was hyperechoic on US, and intramedullary vessels of adjacent region of injury were increased and dilated on CDFI. On CEUS hypoperfusion were found in the epicenter of injury, while hyperperfusion in its adjacent region. Quantitative analysis showed that peak intensity (PI) decreased in epicenters of injury but significantly increased in adjacent regions at all time points (p < 0.05). Functional evaluation demonstrated significant deterioration compared to pre-contusion (p < 0.05). Quantitative analysis with CEUS is a promising method for monitoring perfusion changes of spinal cord injury in overall views and real-time.

CEUS of Problematic Renal Masses: Comparison with CECT and CEMRI

Ultrasound (US) is often the first-line imaging modality in the evaluation of the renal masses. If the findings of a renal mass do not meet all of US criteria of a simple cyst, it should be characterized further. Usually characterization of indeterminate renal masses is well done with CT or MRI, but sometimes it is inconclusive on these imaging techniques. In thoses cases and in patients to whom radiation exposure or use of iodine or gadolinium contrast agents is undesirable, contrast-enhanced US (CEUS) may be a valuable alternative to evaluate those problematic renal masses. CEUS may replace CECT or CEMRI if the patient has marginal or poor renal function, hypersensitivity to iodine contrast agent, or fear of radiation exposure. CEUS has long history in medical US but drew attention only recently. With the first generation microbubble agents several studies showed added value of CEUS as compared to the conventional Doppler US. We reported that CEUS provided better visualization of tumor vascularity in indeterminate cystic renal lesions than other imaging modalities using a first-generation agtent. The most important limitation of the first generation agent was that it could not provide an enough duration of contrast enhancing effect. With introduction of the second generation microbubble agents with better stability and duration of contrast effect, CEUS examination became a practical alternative of CECT or CEMRI in evaluation of problematic renal masses. We do not think that CEUS will be used routinely in US examination of renal masses like contrast enhancement is routine in CT for renal masses. However, we are sure that CEUS will be a valuable imaging technique if it is used in well selected cases of problematic renal masses. In evaluating problematic renal masses, CEUS may reveal findings that were not seen or confirm findings equivocal at other imaging studies. Results of CEUS can be analyzed qualitatively as to the presence or absence of enhancement, vascular pattern and heterogeneity etc. Quantitative analysis can be done on peak intensity, time to peak, and rate of wash-in and wash-out, etc.

The Role of Doppler Ultrasound in Cirrhosis

In clinical hepatology, ultrasound (US) examination is necessary and widely used tool for disease diagnosis, assessment and monitoring. With prevalent viral hepatitis in Taiwan, both conventional and color Doppler US are important for liver disease and cirrhosis evaluation. The change of portal flow, hepatic venous flow (wave form) and splenoportal index are proved to be correlated with the severity of liver cirrhosis. Color Doppler US provided important information about cirrhosis diagnosis, staging and prognosis in liver cirrhosis. Besides the parenchymal change, color Doppler US could examine the hepatic vasculature and identify various kinds of vascular anomaly and shunts. The detection by color Doppler US of vascular thrombosis in cirrhosis and in liver cancer vascular invasion are also a key issue in clinical presentation and management.

Vector Flow Imaging Compared with Conventional Doppler Ultrasound and Thermodilution for Estimation of Blood Flow in the Ascending Aorta

Transverse oscillation (TO) is a real-time ultrasound vector flow method implemented on a commercial scanner. The TO setup was examined on a flowrig with constant and pulsatile flow. Subsequently, 25 patients undergoing cardiac bypass surgery were scanned intraoperatively with TO on the ascending aorta and compared to transesophageal echocardiography (TEE) and pulmonary artery catheter thermodilution (PACTD). On the flowrig, TO had a precision of 5.5%, 9.4% and 14.7%, a percentage error of 18.2%, 14.6% and 40.7%, and a mean bias of 0.4 cm/s, 36.8 ml/min and 32.4 ml/min for velocity and flow rate (constant and pulsatile) estimation. The correlation coefficients for all flowrig evaluations were 0.99 indicating systematic bias. After bias correction, the percentage error was reduced to 11.5%, 12.6% and 15.9% for velocity and flow rate (constant and pulsatile) estimation. In the in vivo setup, TO, TEE, and PACTD had a precision of 21.9%, 13.7%, and 12.0%. TO compared with TEE and PACTD had a mean bias of 12.6 cm/s and -0.08 l/min, and a percentage error of 23.4%, and 36.7%, respectively. The percentage error was reduced to 22.9% for the TEE comparison, but increased to 43.8% for the PACTD comparison, after correction for the systematic bias found in the flowrig. TO is a reliable and precise method for velocity and flow rate estimation on a flowrig. However, TO with the present setup, is not interchangeable with PACTD for cardiac volume flow estimation, but is a reliable and precise angle-independent ultrasound alternative for velocity estimation of cardiac flow.

Hepatic artery resistive index (HARI) and non-alcoholic fatty liver disease (NAFLD) fibrosis score in NAFLD patients: cut-off suggestive of non-alcoholic steatohepatitis (NASH) evolution.

Conventional ultrasound (US) is reliable to reveal the presence of non-alcoholic fatty liver disease (NAFLD), but it is neither sensitive nor specific to reveal fibrosis clues, except in advanced stages where signs of cirrhosis are evident. NALFD fibrosis score is a non-invasive parameter that predicts well the presence of significant fibrosis, but correlations with US parameters are lacking. The aim of this study was, therefore, to compare resistive index of hepatic artery (HARI) of NAFLD patients with different severity degrees of diffuse fatty liver disease vs HARI of controls, and to compare HARI of NAFLD patients with different NAFLD fibrosis scores vs HARI of controls. This was a spontaneous, no-profit observational study conducted in our US department between December 2013 and July 2014. Patients with NAFLD with different severity of disease and healthy controls were included. Echogenicity and size of liver and spleen, maximum portal vein velocity, RI, peak systolic velocity (PSV), and end diastolic velocity (EDV) of splenic artery, PSV, EDV, and RI of hepatic artery, and NAFLD fibrosis score were acquired and compared between groups. HARI was significantly lower in NAFLD patients than controls (p<0.0001). A significant difference was also found between the groups of NAFLD severity (p<0.0001). There was also a difference between HARI of NAFLD patients with different NAFLD fibrosis scores vs HARI of controls (p<0.0001) with a positive correlation between HARI and NAFLD fibrosis score. Conventional Doppler US can be helpful to detect NAFLD patients with the risk of fibrous tissue accumulation. HARI tends to exceed the range of controls for patients with NAFLD fibrosis score greater than 0.675. The detection of HARI greater than 0.9 in NAFLD patients, regardless of the US degree of severity of steatosis, might suggest the execution of biopsy to predict the risk of progression to steatohepatitis and fibrous tissue accumulation. Low values of HARI may be expression of lower risk, which does not necessitate any biopsy.

Oral Presentation III

ABSTRACT BACKGROUND AND AIMS Thyroid nodules occur in more than 50% of populations over 50 years, and only 5% of thyroid nodules are malignant. This study was aimed to evaluate Doppler ultrasonography (US) combined with elastography in the diagnosis of the malignant thyroid nodules with suspicious fine needle aspiration cytological (FNAC) results. METHODS From August 2012 to March 2013, 107 consecutive patients eligible for thyroid surgery enrolled in the study. All patients underwent FNAC study followed by conventional US, color Doppler US, and US elastography with a real-time instrument. Thyroid nodules ultrasonographic parameters were evaluated during conventional and color Doppler US study and elastography performed in order to calculate the strain index (SI) by dividing the strain value of the nodule by that of the peripheral normal parenchyma, prior to thyroidectomy. RESULTS Of 161 nodules in 107 patients, 76 (47.2%) were benign lesions and 85 (52.8%) were malignant. The overall Doppler US score depicted a sensitivity of 64% and specificity of 59%. Using a cut of 2.905, the sensitivity and specificity for elastography US were about 54 and 76% respectively, with positive predictive value of 71.8% and negative predictive value of 59.8%. Evaluating quantitative elastography combined with Doppler US, out of 68 nodules with positive peripheral halo ring, 44 had elasticity ≥ 2.905, which was statistically significant (p &lt; 0.001). CONCLUSION Quantitative elastography combined with Doppler US is more accurate in thyroid nodules diagnosis comparing to other methods and can limit the use of FNAC and the subsequent thyroidectomy in patients with nondiagnostic or unsatisfactory cytological findings.

Utility of Real-Time Shear Wave Elastography in the Assessment of Testicular Torsion.

Real-time shear-wave elastography (SWE) is a newly developed method which can obtain the stiffness of tissues and organs based on tracking of shear wave propagation through a structure. Several studies have demonstrated its potential in the differentiation between diseased and normal tissue in clinical practices, however the applicability to testicular disease has not been well elucidated. We investigated the feasibility and reproducibility of SWE in the detection of testicular torsion. This prospective study comprised 15 patients with complete testicular torsion. Results obtained from SWE along with conventional gray-scale and color Doppler sonography and post-operative pathology were compared. The results revealed that (i) the size of injured testis was increased and the twisted testis parenchyma was heterogeneous. The blood flow signals in injured testis were barely visible or absent; (ii) The Young’s modulus, including Emean, Emax, Emin and SD values in the border area of torsional testis were higher than those of normal testis (Emean, 78.07±9.01kPa vs 22.0±5.10kPa; Emax,94.07±6.53kPa vs 27.87±5.78kPa; Emin, 60.73±7.84 kPa vs 18.90±4.39kPa; SD, 7.67±0.60 kPa vs 2.30±0.36 kPa, [P<0.05]); The Emax and SD values in the central area of the torsional testis were higher than the corresponding area of the normal testis (Emax, 8.23±0.30 kPa vs 3.97±0.95kPa; SD, 1.5±0.26kPa vs 0.67±0.35kPa,[P<0.05]) and Emin values was lower than those of normal testicles(0.93±0.51kPa vs 1.6±0.36kPa; [P<0.05]); (iii) The Young's modulus measurement between two physicians showed good agreement. The pathological findings were accordance with SWE measurement. SWE is a non-invasive, convenient and high reproducible method and may serve as an important alternative tool in the diagnosis and monitoring the progression of the acute scrotums, in additional to conventional Doppler sonography.

UltraFast Doppler ultrasonography for hepatic vessels of liver recipients: preliminary experiences.

Purpose:The purpose of this study was to investigate the value of UltraFast Doppler ultrasonography (US) for evaluating hepatic vessels in liver recipients.Methods:Thirty-nine liver Doppler US sessions were conducted in 20 liver recipients. Each session consisted of UltraFast and conventional liver Doppler US in a random order. We compared the velocities and phasicities of the hepatic vessels, duration of each Doppler study, occurrence of technical failures, and differences in clinical decisions.Results:The velocities and resistive index values of hepatic vessels showed a strong positive correlation between the two Doppler studies (mean R=0.806; range, 0.710 to 0.924). The phasicities of the hepatic vessels were the same in both Doppler US exams. With respect to the duration of the Doppler US exam, there was no significant difference between the UltraFast (251±99 seconds) and conventional (231±117 seconds) Doppler studies (P=0.306). In five poor breath-holders, in whom the duration of conventional Doppler US was longer, UltraFast Doppler US (272±157 seconds) required a shorter time than conventional Doppler US (381±133 seconds; P=0.005). There was no difference between the two techniques with respect to technical failures and clinical decisions.Conclusion:UltraFast Doppler US is clinically equivalent to conventional Doppler US with advantages for poor breath-holders during the post-liver transplantation work-up.

High-frame-rate 2-D vector blood flow imaging in the frequency domain.

Conventional ultrasound Doppler techniques estimate the blood velocity exclusively in the axial direction to produce the sonograms and color flow maps needed for diagnosis of cardiovascular diseases. In this paper, a novel method to produce bi-dimensional maps of 2-D velocity vectors is proposed. The region of interest (ROI) is illuminated by plane waves transmitted at the pulse repetition frequency (PRF) in a fixed direction. For each transmitted plane wave, the backscattered echoes are recombined offline to produce the radio-frequency image of the ROI. The local 2-D phase shifts between consecutive speckle images are efficiently estimated in the frequency domain, to produce vector maps up to 15 kHz PRF. Simulations and in vitro steady-flow experiments with different setup conditions have been conducted to thoroughly evaluate the method's performance. Bias is proved to be lower than 10% in most simulations and lower than 20% in experiments. Further simulations and in vivo experiments have been made to test the approach's feasibility in pulsatile flow conditions. It has been estimated that the computation of the frequency domain algorithm is more than 50 times faster than the computation of the reference 2-D cross-correlation algorithm.