Role Of Doppler US Research Articles

Sonographic Assessment of Fetal Growth Abnormalities.

Fetal growth abnormalities have significant consequences for pregnancy management and maternal and fetal well-being. The accurate diagnosis of fetal growth abnormalities contributes to optimal antenatal management, which may minimize the sequelae of inadequate or excessive fetal growth. An accurate diagnosis of abnormal fetal growth depends on accurate pregnancy dating and serial growth measurements. The fetal size at any given stage of pregnancy is either appropriate or inappropriate for the given gestational age (GA). Pregnancy dating is most accurate in the first trimester, as biologic variability does not come into play until the second and third trimesters. The authors describe the determination of GA with use of standard US measurements and how additional parameters can be used to confirm dating. Once dates are established, serial measurements are used to identity abnormal growth patterns. The sometimes confusing definitions of abnormal growth are clarified, the differentiation of a constitutionally small but healthy fetus from a growth-restricted at-risk fetus is described, and the roles of Doppler US and other adjunctive examinations in the management of growth restriction are discussed. In addition, the definition of selective growth restriction in twin pregnancy is briefly discussed, as is the role of Doppler US in the classification of subtypes of selective growth restriction in monochorionic twinning. The criteria for diagnosing macrosomia and the management of affected pregnancies also are reviewed. The importance of correct pregnancy dating in the detection and surveillance of abnormal fetal growth and for prevention of perinatal maternal and fetal morbidity and mortality cannot be overstated. The online slide presentation from the RSNA Annual Meeting is available for this article. ©RSNA, 2020.

Role of pretreatment Doppler ultrasound in the prediction of factors affecting stone-clearance post-shockwave lithotripsy for ureteral stones: a prospective study.

To identify the role of Doppler US (DUS) in the prediction of factors affecting stone-clearance post-SWL for ureteral stones in addition to its role in prediction of pretreatment stone impaction. We prospectively included patients with ureteric stone for SWL between October 2018 and September 2019. Patient's demographics were collected. Using DUS, resistive index (RI), Δ RI, and ureteric jets were evaluated in both kidneys. Also, stone site, volume, density, skin to stone distance, degree of hydronephrosis, ureteral wall thickness (UWT) were evaluated by NCCT. Univariate and multivariate logistic regression analyses were performed to identify factors that contribute to treatment success. Correlation between ipsilateral RI with other radiological findings predicting stone impaction was done. A total of 93 patients were finally included (61 males and 32 females). The mean age was 31.4 ± 7.7years. The success rate (absence of significantresiduals post 1month by NCCT) was 51.6%. In multivariate analysis, the presence of ureteric jet, ipsilateral lower RI, and ipsilateral lower UWT were independent factors for treatment success (P = 0.0001, 0.002, and 0.03, respectively). Also, ipsilateral absence of ureteric jet, increased hydronephrosis, and increased UWT were correlated with higher ipsilateral RI in prediction of stone impaction. Ipsilateral higher RI was found to achieve higher accuracy in stone impaction prediction (PPV of 94.8%). Pretreatment DUS is a useful, non-invasive with a less irradiative tool for prediction of stone impaction and stone-free rate post-SWL for ureteric stones.

A Radiologist's Guide to the Performance and Interpretation of Obstetric Doppler US.

Doppler US provides a unique window to the fetoplacental circulation, allowing assessment of fetal well-being. Doppler US of the umbilical artery is an integral component of managing the fetus with growth restriction; and Doppler US of the middle cerebral artery, as a noninvasive means of detecting fetal anemia, has revolutionized the management of pregnancies complicated by alloimmunization. Serial use of amniocentesis, with its attendant risks, has been replaced by serial Doppler US examinations. Invasive procedures are now reserved for the treatment of anemia with intrauterine transfusion. Technique is critical to obtain the best waveforms for ease of shape assessment, velocity measurement, and calculation of various ratios. In this article, the safety of Doppler US is reviewed, the fetal circulation is described, and the role of Doppler US is demonstrated in first-trimester screening and in the evaluation of growth restriction, anemia, and other causes of fetal compromise in the second and third trimesters. Sampling technique is explained, and normal and abnormal waveforms are illustrated for the ductus venosus, umbilical artery, umbilical vein, middle cerebral artery, and uterine artery. Some examples of clinical cases are provided to illustrate how the results are used in clinical practice. Clinical examples of velamentous insertion and vasa previa are also provided to aid the practicing radiologist with recognition of these entities. In particular, vasa previa is considered a critical finding; it alters pregnancy management, requiring hospital admission, administration of steroid therapy, and planned early cesarean delivery. ©RSNA, 2019.

Role of Doppler US and MRI in diagnosis of placenta accreta

The aim of this work is to evaluate the role of Doppler US and MRI in the diagnosis of placenta accreta. Patients and methodsDuring period between 2012 to 2013, 120 pregnant patients with previous cesarean section were investigated by ultrasound and Doppler and then in suspected cases MRI was obtained (10 cases). The Sonographic and MRI diagnoses were compared with the final pathologic or operative findings or with both. ResultsThe mean age of this study group was 29years ranging from 20 to 40. Among patients with confirmed placenta accreta, the mean age was 32.25 ranging from 25 to 40years. The mean parity of patients ranged from 1 to 6 with a mean of 1.6. Among patients with placenta accreta, the mean parity ranged from 2 to 6 with a mean of 3.75. The total number of cases with placenta accreta in this study was 4, all of which were previa. This was out of a total of 25 cases of placenta previa. Transabdominal US features were the presence of intraplacental lacunae (sonolucencies), loss of retroplacental clear zone and disruption of bladder–uterine serosa interface with smallest myometrial thickness <1mm over site of placental implantation by using color Doppler ultrasonography, the most prominent color Doppler feature in this study was the presence of intraplacental lacunar flow. Magnetic resonance imaging accurately predicted placenta accreta in 4 of 4 cases with placenta accreta and correctly ruled out placenta accreta in the rest six cases. ConclusionIn conclusion, data of the present study show that the use of transabdominal color Doppler ultrasonography complemented by MRI in suspected cases improves the diagnostic accuracy in prediction of placenta accreta in patients with previous cesarean delivery.

The role of Doppler ultrasound in rheumatic diseases

The use of Doppler techniques, including power, colour and spectral Doppler, has greatly increased in rheumatology in recent years. This is due to the ability of Doppler US (DUS) to detect pathological vascularization within joints and periarticular soft tissues, thereby demonstrating the presence of active inflammation, which has been reported to be correlated with the local neo-angiogenesis. In synovitis, DUS showed a high correlation with histological and MRI findings, thus it is considered a valid tool to detect pathological synovial vascularization. Moreover, it is more sensitive than clinical examination in detecting active joint inflammation and in the evaluation of response to treatment. In addition, DUS may be considered as a reference imaging modality in the assessment of enthesitis, MRI being not sensitive and histology not feasible. Moreover, it has been demonstrated to be able to detect changes in asymptomatic enthesis. In conclusion, DUS is a useful and sensitive tool in the evaluation and monitoring of active inflammation. Its widespread use in clinical rheumatological practice is recommended. The aim of this article is to review the current literature about the role of DUS in rheumatic diseases, analysing its validity, reliability and feasibility.

Comment intégrer l’imagerie moderne dans le diagnostic précoce et le suivi de la spondylarthrite ankylosante ?

It is becoming increasingly desirable to diagnose ankylosing spondyloarthropathy (AS) at its pre-radiographic stage (prior to the presence of sacro-iliitis on radiographs). MRI plays a key role for early diagnosis of AS, as illustrated by recently proposed international diagnostic criteria (ASAS). MRI of the SI joints is most helpful for early diagnosis; sequences using fat suppression and/or Gadolinium administration are necessary for the detection of inflammatory changes. However, the rate of false positive and false negative results of MR imaging of the SI joints, especially early in the course of the disease, is unknown and requires prudent interpretation of imaging findings. In patients with normal MRI examination of the SI joints and/or if symptoms are limited to the spine, MRI of the lumbar spine with STIR and/or Gadolinium administration may be helpful; again the positive and negative predictive values are unknown, especially early in the course of the disease. The demonstration of inflammatory changes on MRI, at the axial level, could be an indication for anti-TNF treatment, outside of WMA (national and international recommendations). The role of Doppler US, especially for peripheral entheses, remains hypothetical for early diagnosis. The role of MRI for structural evaluation is also being assessed even though radiographs remain the standard of reference. To date, no treatment, conventional or other, has been shown to have a structural effect (aside from limitations related to the methodology of available studies).

3470: The role of Doppler US in segmental liver transplantation in children

Doppler US plays an important role in postoperative evaluation for children with segmental liver transplantation. Problems following transplantation include acute rejection, perihepatic fluid collections, and vascular and biliary complications. Focal fluid collections were most often seen immediately after surgery along the cut surface of the graft. Vascular complications included stenoses of the hepatic arteries, hepatic veins and portal veins. Radiologic interventions involved drainage of fluid collections under US guidance, percutaneous cholangiography and angioplasty of vascular anastomoses.

2415: Role of Doppler US for the diagnosis of hepatic venous congestion in the anterior segment of the modified right lobe graft after living donor liver transplantation: A prospective study of 40 patients

Objectives: To assess the value of Doppler US for the diagnosis of hepatic venous congestion (HVC) in anterior segment of the modified right-lobe graft (MRLG) after living donor liver transplantation (LDLT).Methods: Doppler US in 40 patients following LDLT with MRLG, in which middle hepatic vein tributaries(MHVT) larger than 5 mm were reconstituted with interposition vein graft, were prospectively evaluated. On color Doppler US, the number of MHVT of anterior segment of MRLG, their flow velocity and direction and reversal of segmental portal vein were evaluated. In addition, parenchymal echogenecity on grayscale US was recorded. HVC was diagnosed when there is dampened flow of MHVT in anterior segment of MRLG. Doppler US results were correlated to CT and angiographic findings.Results: Doppler US identified 100 of 103 MHVT larger than 5 mm (sensitivity 97%). The sensitivity and specificity of Doppler US for diagnosis of HVC was 89% (8/9) and 93% (85/91). Among 10 territories with HVC, increase of parenchymal echogenecity, reversed flow of MHVT and reversal of segmental portal vein was found in 7, 5 and 1, respectively.Conclusions: Doppler US provide excellent noninvasive screening for HVC in anterior segment of MRLG after LDLT. Dampened flow of MHVT larger than 5 mm may indicate HVC. Objectives: To assess the value of Doppler US for the diagnosis of hepatic venous congestion (HVC) in anterior segment of the modified right-lobe graft (MRLG) after living donor liver transplantation (LDLT). Methods: Doppler US in 40 patients following LDLT with MRLG, in which middle hepatic vein tributaries(MHVT) larger than 5 mm were reconstituted with interposition vein graft, were prospectively evaluated. On color Doppler US, the number of MHVT of anterior segment of MRLG, their flow velocity and direction and reversal of segmental portal vein were evaluated. In addition, parenchymal echogenecity on grayscale US was recorded. HVC was diagnosed when there is dampened flow of MHVT in anterior segment of MRLG. Doppler US results were correlated to CT and angiographic findings. Results: Doppler US identified 100 of 103 MHVT larger than 5 mm (sensitivity 97%). The sensitivity and specificity of Doppler US for diagnosis of HVC was 89% (8/9) and 93% (85/91). Among 10 territories with HVC, increase of parenchymal echogenecity, reversed flow of MHVT and reversal of segmental portal vein was found in 7, 5 and 1, respectively. Conclusions: Doppler US provide excellent noninvasive screening for HVC in anterior segment of MRLG after LDLT. Dampened flow of MHVT larger than 5 mm may indicate HVC.