Microvascular Flow Imaging: A State-of-the-Art Review of Clinical Use and Promise.

Vascular imaging with color and power Doppler is a useful tool in the assessment of various disease processes. Assessment of blood flow, from infarction and ischemia to hyperemia, in organs, neoplasms, and vessels, is used in nearly every US investigation. Recent developments in this area are sensitive to small-vessel low velocity flow without use of intravenous contrast agents, known as microvascular flow imaging (MVFI). MVFI is more sensitive in detection of small vessels than color, power, and spectral Doppler, reducing the need for follow-up contrast-enhanced US (CEUS), CT, and MRI, except when arterial and venous wash-in and washout characteristics would be helpful in diagnosis. Varying clinical applications of MVFI are reviewed in adult and pediatric populations, including its technical underpinnings. MVFI shows promise in assessment of several conditions including benign and malignant lesions in the liver and kidney, acute pathologic abnormalities in the gallbladder and testes, and superficial lymph nodes. Future potential of MVFI in different conditions (eg, endovascular repair) is discussed. Finally, clinical cases in which MVFI correlated and potentially obviated additional CEUS, CT, or MRI are shown

Contrast-enhanced ultrasound (CEUS) appearances of an adrenal phaeochromocytoma in a child with Von Hippel-Lindau disease

A phaeochromocytoma is a rare catecholamine-secreting tumour arising from the chromaffin cells. We describe a case of a child with Von Hippel-Lindau disease, with an adrenal phaeochromocytoma who presented with severe dilated cardiomyopathy driven by secondary hypertension. Contrast-enhanced ultrasound findings are described and compared with both magnetic resonance imaging and computed tomography imaging

Multiparametric Sonography of Hematologic Malignancies of the Testis: Grayscale, Color Doppler, and Contrast-Enhanced Ultrasound and Strain Elastographic Appearances With Histologic Correlation

Primary testicular lymphoma is rare and appears with nonspecific findings on grayscale and color Doppler sonography. We present 8 patients further examined with contrast-enhanced sonography, strain elastography, and histologic analysis after orchiectomy. Seven of 8 patients had a diagnosis of large B-cell lymphoma, and 1 of 8 had a diagnosis of granulocytic sarcoma, with solitary lesions (2 of 8), multiple lesions (3 of 8), or entire testicular involvement (3 of 8). Lesions appeared hypoechoic (7 of 8) or isoechoic (1 of 8), all with increased vascularity on color Doppler sonography and a nonbranching linear pattern of intratumoral vessels (7 of 8). Contrast-enhanced ultrasound (CEUS) confirmed this pattern and showed increased enhancement in all lesions. On strain elastography, all lesions were hard, with an elasticity score of greater than 4. Multiparametric sonography of testicular lymphoma identifies increased vascularity on color Doppler and contrast-enhanced ultrasound and increased lesion stiffness on strain elastography

Complications of congenital portosystemic shunts: liver tumors are affected by shunt severity, but pulmonary and neurocognitive associations are not

Background and purpose: Congenital portosystemic shunts (CPSS) are associated with multisystem complications, with the most common being liver tumors. The purpose of this study is to investigate the incidence of complications of CPSS, and to determine the natural history of liver tumors and their relationship with shunt closure. Methods: Single-center retrospective cohort study of patients with CPSS referred from 1990 to 2020. Data on demographics, laboratory, radiological and histological investigations, clinical evolution, and surgery were reviewed. Mann-Whitney for continuous data and Fisher's exact test for categorical data were used. A p value of 0.05 was considered significant. Results: 54 patients were investigated for CPSS with a median age of 1.1 years (IQR 0.2-11.8 years) at presentation-7 intrahepatic shunts resolved spontaneously and were excluded. Type 1 (without intrahepatic portal flow) had a higher rate of all hepatic tumors than Type 2 (partial intrahepatic portal flow) [18/22(82%) vs. 9/25(36%); p = 0.003); and malignant tumors (6/22(27%) vs 1/25(4%); (p = 0.04). Following shunt closure, 4/11(36%) of patients experienced partial and 3/11(27%) complete tumor regression. Pulmonary hypertension and hepatopulmonary syndrome affected 4(9%), and 3(6%) patients, respectively. Pulmonary complications affected 1 patient with Type 1 and 6 with Type 2 shunts (p = 0.1). Neurocognitive anomalies were identified in 16/47(34%) patients, 8/22(35%) with Type 1 shunts and 8/25(32%) with Type 2 shunts (p = 0.76). 9/47 (19%) required special needs schooling. Conclusions: Severity of portal venous deprivation (Type 1 CPSS) increases the risk of hepatic tumors and surgical closure is associated with a reduction in size or complete resolution of benign tumors.</p

Sonographic imaging of extra-testicular focal lesions: comparison of grey-scale, colour Doppler and contrast-enhanced ultrasound

Extra-testicular lesions are usually benign but present with nonspecific grey-scale sonography findings. This study assesses conventional sonographic characteristics in the differentiation of extra-testicular tumoural from inflammatory lesions and whether contrast-enhanced ultrasound has a role. A retrospective database analysis was performed. All patients were examined by experienced sonographers employing standard techniques combining grey-scale, colour Doppler sonography and contrast-enhanced ultrasound. Features recorded were: clinical symptoms, size, location, echogenicity, colour Doppler sonography and contrast-enhanced ultrasound enhancement. Vascularity on colour Doppler sonography and contrast-enhanced ultrasound was graded and compared. The lesions were classified as tumoural or inflammatory. The Chi-square test was used to analyse the sonographic patterns and kappa coefficient to measure the agreement between colour Doppler sonography and contrast-enhanced ultrasound. A total of 30 lesions were reviewed (median diameter 12 mm, range 5-80 mm, median age 52 years, range 18-86 years), including 13/30 tumoural and 17/30 inflammatory lesions. Lesions were hypoechoic (n = 12), isoechoic (n = 6), hyperechoic (n = 2) or mixed (n = 10). Grey-scale characteristics of tumoural vs. inflammatory lesions differed significantly (P = 0.026). On colour Doppler sonography, lesions had no vessels (n = 16), 2-3 vessels (n = 10) and ≥4 vessels (n = 4). On contrast-enhanced ultrasound, lesions showed no vascularity (n = 17), perfusion similar to testis (n = 7) and higher (n = 6). All abscesses identified (n = 9) showed no vascularity on both colour Doppler sonography and contrast-enhanced ultrasound. There was good agreement between these techniques in evaluating vascularity (κ = 0.719) and no significant difference between colour Doppler sonography and contrast-enhanced ultrasound of tumoural vs. inflammatory lesions (P > 0.05). The grey-scale appearances of extra-testicular lesions are essential for characterisation. Colour Doppler sonography and contrast-enhanced ultrasound findings are not useful in that respect. Contrast-enhanced ultrasound is excellent in establishing absence of vascularity

Development of and Gathering Validity Evidence for a Theoretical Test in Contrast-Enhanced Ultrasound.

Contrast-enhanced ultrasound (CEUS) is an imaging modality applied in a broad field of medical specialties for diagnostic uses, guidance during biopsy procedures and ablation therapies and sonoporation therapy. Appropriate training and assessment of theoretical and practical competencies are recommended before practicing CEUS, but no validated assessment tools exist. This study was aimed at developing a theoretical multiple-choice question-based test for core CEUS competencies and gathering validity evidence for the test. An expert team developed the test via a Delphi process. The test was administered to medical doctors with varying CEUS experience, and the results were used to evaluate test items, internal-consistency reliability, ability to distinguish between different proficiency levels and to establish a pass/fail score. Validity evidence was gathered according to Messick's framework. The final test with 47 test items could distinguish between operators with and without CEUS experience with acceptable reliability. The pass/fail score led to considerable risk of false positives and negatives. The test may be used as an entry test before learning practical CEUS competencies but is not recommended for certification purposes because of the risk of false positives and negatives

Common and uncommon features of focal splenic lesions on contrast-enhanced ultrasound: a pictorial review

<div><p>Abstract The characterization of focal splenic lesions by ultrasound can be quite challenging. The recent introduction of contrast-enhanced ultrasound (CEUS) has come to play a valuable role in the field of imaging splenic pathologies, offering the possibility of an ionizing radiation-free investigation. Because CEUS has been incorporated into everyday clinical practice, malignant diseases such as focal lymphomatous infiltration, metastatic deposits, benign cysts, traumatic fractures, and hemangiomas can now be accurately depicted and characterized without the need for further imaging. More specifically, splenic traumatic fractures do not require additional imaging by computed tomography (with ionizing radiation exposure) for follow-up, because splenic fractures and their complications are safely imaged with CEUS. In the new era of CEUS, more patients benefit from radiation-free investigation of splenic pathologies with high diagnostic accuracy.</p></div