Ultrasound for Lower Extremity Deep Venous Thrombosis: Multidisciplinary Recommendations From the Society of Radiologists in Ultrasound Consensus Conference.

Venous ultrasound is the standard imaging test for patients suspected of having acute deep venous thrombosis (DVT). There is variability and disagreement among authoritative groups regarding the necessary components of the test. Some protocols include scanning the entire lower extremity, whereas others recommend scans limited to the thigh and knee supplemented with serial testing. Some protocols use gray-scale ultrasound alone, whereas others include Doppler interrogation. Point-of-care ultrasound is recommended in some settings, and there is heterogeneity of these protocols as well. Heterogeneity of recommendations can lead to errors including incorrect application of guidelines, confusion among requesting physicians, and incorrect follow-up. In October 2016, the Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts to evaluate the current evidence to develop recommendations regarding ultrasound protocols for DVT and the terminology used to communicate results to clinicians. Recommendations were made after open discussion and by unanimous consensus.The panel recommends a comprehensive duplex ultrasound protocol from thigh to ankle with Doppler at selected sites rather than a limited or complete compression-only examination. This protocol is currently performed in many facilities and is achievable with standard ultrasound equipment and personnel. The use of these recommendations will increase the diagnosis of calf DVT and provide better data to explain the presenting symptoms. The panel recommends a single point-of-care protocol that minimizes underdiagnoses of proximal DVT.The panel recommends the term chronic postthrombotic change to describe the residual material that persists after the acute presentation of DVT to avoid potential overtreatment of prior thrombus.Adoption of a single standardized comprehensive duplex ultrasound and a single point-of-care examination will enhance patient safety and clinicians' confidence.

Visualization of the Oropharynx With Transcervical Ultrasound.

OBJECTIVE: The purposes of this article are to illustrate the sonographic appearance of the oropharynx and to discuss the potential role of ultrasound in evaluation of the oropharynx. CONCLUSION: Ultrasound is not currently used in the standard clinical evaluation of the oropharynx, but it is a promising imaging modality for evaluating the base of the tongue and the palatine tonsils. Ultrasound is comparable and complementary to CT and MRI, which have recognized limitations.

Transcranial Doppler ultrasound in children with Sturge-Weber syndrome.

Transcranial Doppler ultrasound is a noninvasive vascular assessment technique proved useful in the management of pediatric disorders predisposed to stroke and may have similar utility for Sturge-Weber syndrome. Eight children with Sturge-Weber syndrome had velocities measured in the major cerebral arteries via the Stroke Prevention Trial in Sickle Cell Anemia methodology. Velocities and pulsatility indexes were compared between the unaffected and affected sides. All subjects had reduced velocity on the affected side; the mean middle cerebral artery percentage difference was 20% (95% CI, 15%-25%). Pulsatility index was increased on the affected side; mean middle cerebral artery pulsatility index percentage difference, 34% (95% CI, 15%-53%). Six subjects also had reduced posterior cerebral artery velocity on the affected side. Side-to-side differences in middle cerebral artery and posterior cerebral artery velocities correlated with severity of MRI asymmetry (Spearman rho = 0.88, P = .02). Decreased arterial flow velocity and increased pulsatility index in the middle cerebral artery and posterior cerebral artery suggests a high resistance pattern that may reflect venous stasis and may contribute to chronic hypoperfusion of brain tissue. Further study of Transcranial Doppler in children with Sturge-Weber syndrome is indicated.

Evaluating oropharyngeal carcinoma with transcervical ultrasound, CT, and MRI.

OBJECTIVE: To compare transcervical ultrasonography (US) to standard cross-sectional imaging for the visualization of human papillomavirus-related oropharyngeal cancer (HPV-OPC). MATERIALS AND METHODS: Patients with HPV-OPC and available standard imaging (CT and/or MRI) were identified in clinic and prospectively enrolled. US was performed to visualize the oropharynx and lymph nodes. Tumor characteristics across imaging modalities were evaluated (CT versus MRI, and US versus standard imaging (SI)). RESULTS: Forty-three patients were included. The overall blinded detection rates for CT and MRI were 83% and 71%, respectively. The unblinded detection rate for US was 98%. Agreement of tumor anatomic subsite was moderate for both CT vs MRI (κ = 0.59) and US vs SI (κ = 0.47). Comparison of tumor size by CT and MRI showed statistically significant correlations in craniocaudal (CC), anteroposterior (AP), and mediolateral (ML) dimensions (RhoCC = 0.51, pCC = 0.038; RhoAP = 0.81, pAP < 0.0001; RhoML = 0.57, pML = 0.012). Tumor size estimates by US and SI showed statistically significant correlations in CC and AP, but not ML (RhoCC = 0.60, pCC = 0.003; RhoAP = 0.71, pAP < 0.0001; RhoML = 0.30, pML = 0.08). Tumor volume estimates improved correlations between US and SI (Rho = 0.66, p < 0.0001). Stratification of US patients into early and late imaging studies demonstrated an increase in correlation strength from early (Rho = 0.32, p = 0.32) to late groups (Rho = 0.77, p < 0.0001) demonstrating that ultrasound accuracy improved with experience. CONCLUSIONS: Our findings suggest that transcervical ultrasonography is a sensitive and relatively accurate adjunct to standard imaging for the evaluation of oropharyngeal tumors. Its cost, portability, and potential for in-clinic and serial imaging render US an attractive modality to further develop for imaging oropharyngeal tumors.

Ultrasound evaluation of the lower extremity veins.

Over the past 2 decades venous ultrasonography has become the standard primary imaging technique for the initial evaluation of patients for whom there is clinical suspicion of deep venous thrombosis (DVT) of the lower extremity veins. This article addresses the role of duplex ultrasonography and color Doppler ultrasonography in today's clinical practice for the evaluation of patients suspected of harboring a thrombus in their lower extremity veins. It reviews the clinical presentation and differential diagnoses, technique, and diagnostic criteria for acute and chronic DVT. In addition, it addresses the sonographic evaluation of venous insufficiency.

Reliability and Clinical Correlation of Transcranial Doppler Ultrasound in Sturge-Weber Syndrome.

BACKGROUND: The reproducibility of transcranial Doppler (TCD) ultrasound measurements in Sturge-Weber syndrome (SWS) and TCD's ability to predict neurological progression is unknown. METHODS: In 14 individuals with SWS, TCD measured mean flow velocity, pulsatility index, peak systolic velocity, and end-diastolic velocity in the middle, posterior, and anterior cerebral arteries of the affected and unaffected hemisphere. TCD was performed either once (n = 5) or twice in one day (n = 9). We assessed the reproducibility of the measurements performed twice on the same day on subjects and compared the TCD measurements to previously published age-matched controls. Clinically obtained neuroimaging was scored for extent and severity of SWS brain involvement. Patients were prospectively assigned SWS neuroscores. RESULTS: Middle cerebral artery velocity (r = 0.79, P = 0.04, n = 7), posterior cerebral artery velocity (r = 0.90, P = 0.04, n = 5), and anterior cerebral artery pulsatility index (r = 0.82, P = 0.02, n = 7) were reproducible TCD measurements comparing same-day percent side-to-side differences. In subjects with SWS, affected and unaffected mean peak systolic velocity and end-diastolic velocity in the middle, posterior, and anterior cerebral arteries were globally lower compared with age-matched control subjects. Subjects with the lowest affected middle cerebral artery velocity had the greatest worsening in the total neurological score between time 1 and 2 (r = -0.73, P = 0.04, n = 8) and the most severe magnetic resonance imaging involvement of the affected frontal lobe (r = -0.82, P = 0.007, n = 9). CONCLUSIONS: TCD may be a reliable measure with potential clinical value, indicating that blood flow may be globally decreased in SWS patients with unilateral brain involvement.

Ultrasound for the assessment of distal shunt malfunction in adults with internal ventricular shunts.

Shunts that are used for the treatment of hydrocephalus have a propensity towards malfunction, however, diagnosing a shunt malfunction can sometimes be a challenge. The purpose of this study was to investigate whether ultrasound technology can be safely and effectively used to assess for distal shunt malfunction. This was a prospective cohort study at a single institution. Eighteen adult patients that received a radionuclide shunt patency study also underwent an ultrasound shunt patency study. Ultrasound with Doppler technology was used to visualize flow through the shunt tubing following manual compression of the shunt reservoir. A peak flow speed was recorded and the results were compared to the results of the radionuclide shunt patency study. A Receiver Operating Characteristic (ROC) curve comparing the ultrasound to the radionuclide shunt patency study was generated, revealing an Area Under the Curve (AUC) of 0.95 (95% CI: 0.84-1.00). The ultrasound test performed maximally with a cutoff speed of ≤10cm/s as the criteria for malfunction, with a sensitivity of 100.00%, specificity of 90.91%, accuracy of 94.44%, positive likelihood ratio of 11.000 and negative likelihood ratio of 0.000 using the radionuclide study results as criteria for comparison. Overall, ultrasound has the potential to be a safe, quick, available and cost-effective screening test for patients with suspected distal shunt malfunction. The high sensitivity of the test makes it an attractive option for use as a screening method that could potentially reduce the number of cases requiring radionuclide shunt patency study.

Vascular and nonvascular complications of liver transplants: sonographic evaluation and correlation with other imaging modalities and findings at surgery and pathology.

Liver transplantation is performed in adults and children to treat patients with irreversible liver damage when medical or other surgical treatment has failed. The most common indications for transplantation are cirrhosis secondary to fulminant acute hepatitis or chronic active hepatitis, sclerosing cholangitis, primary biliary cirrhosis, Budd-Chiari syndrome, inborn errors of metabolism, and unresectable but local hepatocellular carcinoma. This article reviews the sonographic findings in the preoperative evaluation of liver transplant recipients, briefly describes the surgical technique, and demonstrates normal postoperative findings in liver transplant recipients as well as complications associated with liver transplantation.