Acute scrotal pain in pediatric patients: diagnosis with an innovative Doppler technique (MicroV).

Acute scrotal pain is one of the most frequent symptoms in pediatric patients visited in the Emergency Department. Ultrasonography with color and power Doppler represents the first-line method that clinicians use to carry out the differential diagnosis between spermatic cord torsion and inflammation, but sensitivity and specificity are 63-100% and 97-100%, respectively; this variability may be related to operator's experience and testis vascular hemodynamics and also to machine performance and patient age. Recent technological innovations have made possible to create a new Doppler mode called ultrasound microvascular imaging. This technique exploits algorithms capable of separating low frequencies of static tissue artifacts from ones of very weak flows. It is known as MicroV (from Esaote) and Superb microvascular imaging (from Toshiba). It provides both macrocirculation vascular maps, as a typical Doppler feature, and microcirculation vascular maps. Furthermore, the use of background subtraction could improve the visibility of small vascular structures. We report a case of a pediatric patient suffering from acute scrotal pain assessed ultrasonographically with this innovative Doppler technique (MicroV) that may give more confidence in detecting testicular vascular signals if compared with traditional Doppler techniques.

Role of Advanced Hemodynamic Ultrasound Evaluation in the Differential Diagnosis of Middle Cerebral Artery Stenosis: Introducing Morphological Criteria.

OBJECTIVE: The aim of the work described here was to determine the possible impact of the new technique advanced hemodynamic ultrasound evaluation (AHUSE) in identification of severe intracranial stenosis. Transcranial Doppler (TCD) and transcranial color-coded Doppler (TCCD) provide reliable velocimetric data, the indirect analysis of which allows us to obtain information on the patency of vessels and assumed stenosis range. However, very tight stenoses (>95%) cannot be detected with velocimetric criteria because of spectrum drops and the absence of high velocities, so that the right curve of the Spencer equation cannot be solved. Likewise, high velocities are not detected when analyzing morphologically long stenosis. Furthermore, the current classifications based on velocimetric criteria do not provide any categorization on stenoses with multiple acceleration points (MAPs). METHODS: With this Technical Note we aim to introduce, in addition to velocimetric criteria, more morphological criteria based on TCCD with the algorithm of AHUSE to optimize the characterization of intracranial stenosis (IS). TCCD-AHUSE relies on intensity-based next-generation techniques and can be used to identify IS with MAPs and simultaneously perform a morphological assessment of the stenosis length. RESULTS: We introduce a new technical ultrasound (U) approach that we tested in a sample of four different types of stenoses combining velocimetric data and AHUSE using Esaote Microvascularization (MicroV) technique to the M1 tract of the middle cerebral artery (MCA). CONCLUSION: The authors believe that a multiparametric evaluation is more sensitive and supports the clinician by introducing the morphological concept, not just the velocimetric concept, to differentiate the IS pattern of MCA. The potential for developing a diagnostic/prognostic algorithm is discussed.

Intratesticular Vascular Architecture Seen by Ultrasound Microvascular Imaging (MicroV). Illustration of the Testis Vascular Anatomy.

The testis is a richly vascularized organ supplied by low-flow thin caliber vessels that are only partially detected by traditional Doppler systems, such as color and power Doppler. However, in the vascular representation, these techniques determine, albeit to different extents, a cut of the weak vessels due to the necessary application of wall filters that cut the disturbing frequencies responsible for artifacts generated by pulsations of the vascular walls and surrounding tissues. These filters cut a specific range of disturbing frequencies, regardless of whether they may be generated by low-flow vessels. Recently, a new technology, called Ultrasound Microvascular Imaging (MicroV) has been developed, which is particularly sensitive to slow flows. This new mode is based on new algorithms capable of better selecting the low frequencies according to the source of origin and cutting only the disturbing ones, saving the frequencies originating from really weak flows. When Ultrasound microvascular imaging is used, the vascular map is more detailed and composed of macro and microvasculature, with more subdivision branches, facilitating the interpretation of the normal and, consequently, the pathological. This review aims to describe the vascular architecture of the testis with Ultrasound Microvascular Imaging (MicroV) in healthy testis, compared to traditional color/power Doppler, related to normal anatomy.

Intraoperative Evaluation of Brain-Tumor Microvascularization through MicroV IOUS: A Protocol for Image Acquisition and Analysis of Radiomic Features.

Microvascular Doppler (MicroV) is a new-generation Doppler technique developed by Esaote (Esaote s.p.a., Genova, Italy), which is able to visualize small and low-flow vessels through a suppression of interfering signals. MicroV uses advanced filters that are able to differentiate tissue artifacts from low-speed blood flows; by exploiting the space-time coherence information, these filters can selectively suppress tissue components, preserving the signal coming from the microvascular flow. This technique is clinically applied to the study of the vascularization of parenchymatous lesions, often with better diagnostic accuracy than color/power Doppler techniques. The aim of this paper is to develop a reproducible protocol for the recording and collection of MicroV intraoperative ultrasound images by the use of a capable intraoperative ultrasound machine and post-processing aimed at evaluation of brain-tumor microvascularization through the analysis of radiomic features. The proposed protocol has been internally validated on eight patients and will be firstly applied to patients affected by WHO grade IV astrocytoma (glioblastoma-GBM) candidates for craniotomy and lesion removal. In a further stage, it will be generally applied to patients with primary or metastatic brain tumors. IOUS is performed before durotomy. Tumor microvascularization is evaluated using the MicroV Doppler technique and IOUS images are recorded, stored, and post-processed. IOUS images are remotely stored on the BraTIoUS database, which will promote international cooperation and multicentric analysis. Processed images and texture radiomic features are analyzed post-operatively using ImageJ, a free scientific image-analysis software based on the Sun-Java platform. Post-processing protocol is further described in-depth. The study of tumor microvascularization through advanced IOUS techniques such as MicroV could represent, in the future, a non-invasive and real-time method for intraoperative predictive evaluation of the tumor features. This evaluation could finally result in a deeper knowledge of brain-tumor behavior and in the on-going adaptation of the surgery with the improvement of surgical outcomes.

Microvascular imaging ultrasound (MicroV) and power Doppler vascularization analysis in a pediatric population with early scrotal pain onset.

INTRODUCTION: The power Doppler is a useful tool in the evaluation of pediatric acute scrotal pain. Nonetheless, it may have some inherent limitations in scrotal vascularization analysis, potentially causing unnecessary surgery. The microvascular imaging ultrasound (MicroV) is an innovative Doppler technique able to improve the detection of very low flow. This retrospective study aims to compare both power Doppler and MicroV in the evaluation of a pediatric population with early-stage scrotal pain onset, first in testis vascularization analysis, and second in their diagnostic performances. MATERIALS AND METHODS: 69 patients met the following inclusion criteria, age < 18-year-old, a clinical diagnosis of acute scrotal disease, pain onset ≤ 6 h, ultrasound examination (including B-mode, power Doppler, and MicroV), 3-months follow-up. For both power Doppler and MicroV, through a defined vascularization scale, it was evaluated the agreement in vascularization detection, and the sensitivity and specificity in US diagnostic abilities. RESULTS: Retrospective diagnoses were of 8 testicular torsion, 15 orchi-epididymitis, and 46 children with other scrotal conditions. Power Doppler provided inconclusive US evaluation in 37.68% of the cases, while MicroV only in the 1.45% (p < 0.0001). Testicular torsion and orchi-epididymitis were identified, respectively, with MicroV in 100% (sensitivity, specificity, PPV, NPV, and accuracy of 100%) and 80% of patients (80% sensitivity, 100% specificity and PPV, 94.73% NPV, 95.65% accuracy); with power Doppler the identification was, respectively, of 87.5% (87.5% sensitivity, 100% specificity and PPV, 98.38% NPV and accuracy) and of 73.3% (73.33% sensitivity, 98.14% specificity, 91.66% PPV, 92.98% NPV, 92.75% accuracy). CONCLUSIONS: Our findings indicate that MicroV is a reliable technique in vascularization detection of pediatric testes, being able also to detect vascularization in healthy testicles with no-flow at power Doppler examination. Moreover, MicroV could be a valuable ally in the US diagnostic of children with early-stage scrotal pain onset.

MicroV Technology to Improve Transcranial Color Coded Doppler Examinations.

The purpose of this review is to provide an update on technology related to Transcranial Color Coded Doppler Examinations. Microvascularization (MicroV) is an emerging Power Doppler technology which can allow visualization of low and weak blood flows even at high depths, thus providing a suitable technique for transcranial ultrasound analysis. With MicroV, reconstruction of the vessel shape can be improved, without any overestimation. Furthermore, by analyzing the Doppler signal, MicroV allows a global image of the Circle of Willis. Transcranial Doppler was originally developed for the velocimetric analysis of intracranial vessels, in particular to detect stenoses and the assessment of collateral circulation. Doppler velocimetric analysis was then compared to other neuroimaging techniques, thus providing a cut-off threshold. Transcranial Color Coded Doppler sonography allowed the characterization of vessel morphology. In both Color Doppler and Power Doppler, the signal overestimated the shape of the intracranial vessels, mostly in the presence of thin vessels and high depths of study. In further neurosonology technology development efforts, attempts have been made to address morphology issues and overcome technical limitations. The use of contrast agents has helped in this regard by introducing harmonics and subtraction software, which allowed better morphological studies of vessels, due to their increased signal-to-noise ratio. Having no limitations in the learning curve, in time and contrast agent techniques, and due to its high signal-to-noise ratio, MicroV has shown great potential to obtain the best morphological definition.