Search

We evaluated nodular fasciitis (NF) in 19 patients, focusing on the correlation between its sonographic and histopathologic features. Sonograms were retrospectively reviewed, and the location, shape, margin, echogenicity, echogenic rim, peripheral hyper-echoic nodules, posterior enhancement and vascularity of the lesions were recorded. In the histopathologic analysis, three patterns—infiltrating, pushing border and well circumscribed—were identified, and culture-like tissue centers were classified according to the distribution of focal keloid-like collagen bundles: uneven or even. For the sonographic–pathologic correlation, most NF cases were inhomogeneously hypo-echoic and had an echogenic rim, with an infiltrating or pushing border pattern. In addition, all NF cases with the infiltrating pattern were observed to have peripheral hyper-echoic nodules in sonograms. Thus, echogenic rims may be associated with the peripheral adipose tissues in infiltrating pattern, and the degree of infiltration may be associated with specific sonographic features of NF.

The breast section of these Guidelines and Recommendations for Elastography produced under the auspices of the World Federation of Ultrasound in Medicine and Biology (WFUMB) assesses the clinically used applications of all forms of elastography used in breast imaging. The literature on various breast elastography techniques is reviewed, and recommendations are made on evidence-based results. Practical advice is given on how to perform and interpret breast elastography for optimal results, with emphasis placed on avoiding pitfalls. Artifacts are reviewed, and the clinical utility of some artifacts is discussed. Both strain and shear wave techniques have been shown to be highly accurate in characterizing breast lesions as benign or malignant. The relationship between the various techniques is discussed, and recommended interpretation based on a BI-RADS-like malignancy probability scale is provided. This document is intended to be used as a reference and to guide clinical users in a practical way.

The importance of assessing tumor response during or after treatment with a novel therapy has long been recognized. Several standardized approaches have been proposed and utilized to evaluate tumor response after systemic and/or loco-regional therapy (LRT). Among the LRT modalities, RFA is one of the most widely accepted methods for treating malignant hepatic tumors. Conventional cross-sectional imaging techniques, such as CT and MRI, have traditionally been used primarily to assess tumor response to RFA, however, ultrasound (US) is the most convenient imaging technique during or after treatment. The utility of microbubble contrast agents (MBCA) greatly enhances the ability of US to delineate lesions or structures and therefore provide more information in diagnosis. Imaging technique providing adequate information pre- and during RFA treatment of liver is crucial to achieve optimal therapeutic outcomes. Studies have shown that CEUS with second-generation USCA as a pre-treatment imaging may increase the target lesion conspicuity and enhance the treatment efficacy. In patients with FLL such as HCC and liver metastases not clearly demarcated on conventional US, complete tumor necrosis could be achieved by using a single session of RFA in 94% with US guidance. While complete tumor necrosis rate as high as 98.2% could be achieved in the CEUS-guided group. The tumor size and number are the most important factors related to the complete ablation and tumor recurrence after RFA. With CEUS guidance and monitoring, an RFA procedure can be done optimally. We herein review the methodologies for measuring tumor response and survival, among patients treated with RFA for primary and secondary hepatic malignancies. The learning objectives of this review include spectrum of US/ CEUS techniques and findings during and after RFA of hepatic tumors.

Ultrasonic elastography is a new technique that can be applied in combination with B-mode sonography for the assessment of breast lesions. There are various methods to obtain elastography of the breast. Several interpretation methods and their relationships based on a BI-RADS classification system have been proposed. The most commonly used interpretation methods include EI/ B (Ratio of the lesion size on elastography to the B-mode size), width ratio, strain ratio, lesion fat ratio (LFR, ratio of target mass stiffness to that of subcutaneous fat). These are semi quantitative value derived from strain elastography (SE). The Tsukuba score, a kind of strain pattern, using a fine-point scale has been used for differentiating between benign and malignant masses with satisfactory accuracy. Vs-shear wave velocity or shear wave speed (SWS) in units of m/s and stiffness or elasticity in units of kPa are quantitative values in shear wave elastography (SWE) systems. Most of recent studies confirmed higher specificity for elastography and higher sensitivity for conventional sonography. Procedures during elastography should be carefully done to avoid some pitfalls of image producing and interpretation. First of all, obtaining an optimal B-mode image and a good elastography image (EI) is essential. A nonperpendicular angle of the probe to the chest wall/ skin, unstable vibration, improper or uneven compression, and patient motion will cause suboptimal EI. A proper interpretation is based on a good EI, and multiple interpretation methods can be applied to a lesion to obtain a proper diagnosis. Difficulty may be encountered when measuring a fibrous tumor arising in dense breast tissue on the elastogram, and false positive result may be created. Some of the problems can be avoided by comparing the stiffness of the lesion to the surrounding tissue and LFR may help eliminate this problem. A cystic lesion may show tri-laminar appearance (blue, green, and red), but if not all three colors are present; comparison with B-mode image is helpful. Elastography systems and the applications themselves continue to evolve with the more recent SWE / SWS techniques; new tools and new evidence will likely emerge. The direction of development, imaging methods will change with new technologies and diagnostic algorithms.

Although examination of the spleen is routinely included in the general abdominal gray-scale ultrasound (US) study, it was considered of limited use in the past and was performed almost only to distinguish between cystic and solid lesions. In the last two decades due to accumulated experience and the introduction of second-generation contrast agents, this technique has been re-evaluated as contrast-enhanced US (CEUS) allows detection and characterization of most focal lesions of the spleen with a high sensitivity and a good specificity. US can provide a correct diagnosis in simple cysts, whereas CEUS is useful when cystic lymphangioma is suspected. US presents a low specificity and relatively low sensitivity in splenic infarctions, while CEUS can achieve a high specificity (up to 100 %). There is a wide spectrum of benign and malignant neoplasms of the spleen. Lymphomas and vascular tumors comprise the most common splenic neoplasms. Splenic hemangiomas and angiosarcomas are the most common mesenchymal tumors in which US and CEUS may show characteristic imaging findings and permit precise diagnosis. US-guided fine needle aspiration and/or biopsy of focal splenic lesions are being increasingly performed to obtain tissue for histopathological characterization. Accurate diagnosis of focal splenic lesions allows institution of optimal patient management. In the study of splenic lesions, the most important problem is to differentiate between angioma, hamartoma, lymphoma, and metastasis. CEUS presents a high specificity in the differentiation of benign and malignant splenic lesions, as hypoenhancement in the parenchymal phase is suggestive of malignancy in 87 % of cases. US, as compared to CT and MRI, has certain advantages, including its ubiquitous availability, lack of ionizing radiation, and low cost, and with additional application of CEUS, can be widely indicated in the study of focal splenic lesions.

We evaluated superficial soft-tissue lymphomas on high-resolution ultrasonography (HRUS) in 43 patients (17 women, 26 men; mean, 59.7 y; range, 12 to 90 y), with 1- to 97-month follow-up. Clinical presentations, tumor location and morphology, echogenicity on HRUS and color-encoding grades on Doppler ultrasonography (CDUS) were assessed. Clinical presentations did not significantly differ with tumor location or morphology. Types of lymphoma did not significantly differ in echogenicity, although most were hypoechogenic. On CDUS, most lymphomas were hypervascular, but grades did not significantly depend on the type of tumor. On Kaplan-Meier analysis with log-rank testing, survival did not differ by age (divided at 65 y), sex, tumor location or size (cut-off, 5 cm), CDUS grade or pathology. Survival was significantly related to clinical presentation (p < 0.0095) and tumor morphology (p < 0.0354). HRUS and CDUS were good modalities to detect the masses and provided important pretreatment information.

Doppler angle ( i.e. , beam-to-flow angle) is an important parameter for quantitative flow measurements. With known Doppler angles, volumetric flows can be obtained by the mean flow velocity times the cross-section area of the vessel. The differences or changes between prestenotic and poststenotic volumetric flows have been quantified as an indicator for assessing the clinical severity of the stenosis. Therefore, several research groups have dedicated themselves to developing user-independent methods to determine automatically the Doppler angle. Nevertheless, most of these methods were developed for narrow ultrasound beam measurements. For small vessels, where the beam width is a significant fraction of the diameter of the vessel, the effect of velocity gradients plays an important role and should not be ignored in the Doppler angle estimations. Accordingly, this paper is concerned with a method for improving the estimation of Doppler angles from spectral width Doppler (SWD) method, but correcting for velocity-gradient broadening that may arise when the beam has a nonzero width. In our method, Doppler angles were firstly calculated by SWD and then were corrected by an artificial neural network (ANN) method to neutralize the contribution of velocity gradient broadening (VGB). This SWD and ANN conjoint method has been successfully applied to estimate Doppler angles from 50° to 80° for constant flows in 10 mm, 4 mm and 1 mm diameter tubes, whose mean flow velocities were 15.3, 19.9 and 25.5 cm/s, respectively, and the achieved mean absolute errors of the estimated Doppler angles were 1.46°, 1.01° and 1.3°. (E-mail: hkchiang@ym.edu.tw )

Segmentation of multiple objects with irregular contours and surrounding sporadic spots is a common practice in ultrasound image analysis. A new region-based approach, called cell-competition algorithm, is proposed for simultaneous segmentation of multiple objects in a sonogram. The algorithm is composed of two essential ideas. One is simultaneous cell-based deformation of regions and the other is cell competition. The cells are generated by two-pass watershed transformations. The cell-competition algorithm has been validated with 13 synthetic images of different contrast-to-noise ratios and 71 breast sonograms. Three assessments have been carried out and the results show that the boundaries derived by the cell-competition algorithm are reasonably comparable to those delineated manually. Moreover, the cell-competition algorithm is robust to the variation of regions-of-interest and a range of thresholds required for the second-pass watershed transformation. The proposed algorithm is also shown to be superior to the region-competition algorithm for both types of images.

To assist the ultrasound (US) differential diagnosis of solid breast tumors by using stepwise logistic regression (SLR) analysis of tumor contour features, we retrospectively reviewed 111 medical records of digitized US images of breast pathologies. They were pathologically proved benign breast tumors from 40 patients (i.e., 40 fibroadenomas) and malignant breast tumors from 71 patients (i.e., 71 infiltrative ductal carcinomas). Radiologists, before analysis by the computer-aided diagnosis (CAD) system, segmented the tumors manually. The contour features were calculated by measuring the radial length of tumor boundaries. The features selection process was accomplished using a stepwise analysis procedure. Then, an SLR model with contour features was used to classify tumors as benign or malignant. In this experiment, cases were sampled with "leave-one-out" test methods to evaluate the SLR performance using a receiver operating characteristic (ROC) curve. The accuracy of our SLR model with contour features for classifying malignancies was 91.0% (101 of 111 tumors), the sensitivity was 97.2% (69 of 71), the specificity was 80.0% (32 of 40), the positive predictive value was 89.6% (69 of 77), and the negative predictive value was 94.1% (32 of 34). The CAD system using SLR can differentiate solid breast nodules with relatively high accuracy and its high negative predictive value could potentially help inexperienced operators to avoid misdiagnoses. Because the SLR model is trainable, it could be optimized if a larger set of tumor images were supplied.

This article predicts the possibility of resorption of the calcific plaques in the shoulder using high-resolution ultrasonography (HRUS) and color Doppler ultrasound (CDUS), and evaluates the therapeutic effect of US-guided fine-needle multiple punctures of the calcific plaque. A total of 100 patients with calcific tendenosis were divided into 3 groups: In group 1, patients having chronic shoulder pain received conservative treatment; in group 2, patients having acute exacerbation of shoulder pain also received conservative treatment; and group 3 patients received US-guided fine-needle multiple punctures or aspiration. In CDUS, all images were classified as grade 0 (no color flow signals), grade 1 (weak spotty color flow signal), grade 2 (few rod-like color flow signals), grade 3 (many rod-like or linear color flow signals). In the follow-up study, marked improvement of patients' clinical condition with more than 50% size reduction of calcific plaque was defined as an effective treatment. There was no significant difference between group 1 and group 3 (p = 0.558) in CDUS, but there was a significant difference between group 1 and group 2 (p = 0.000), and group 2 and group 3 (p = 0.000) on the basis of classification of grade1 and gradeor = 1. There was also significant difference in the follow-up result of effective management between group 1 and group 3 (p = 0.000), and group 1 and group 2 (p = 0.000). In conclusion, HRUS with CDUS proved to be a good modality in evaluating the possibility of resorption of shoulder calcification and, if CDUSor = grade 1 in calcific tendonitis, we highly recommend conservative treatment with regular follow-up. On the other hand, if CDUSgrade 1, fine-needle repeated puncture could be considered as an effective alternative treatment.

In this paper, we present an automatic beam-vector (Doppler) angle and flow velocity measurement method and implement it in pulsatile flow measurements using a clinical Doppler ultrasound system. In current clinical Doppler ultrasound flow velocity measurements, the axis of the blood vessel needs to be set manually on the B-scan image to enable the estimation of the beam-vector angle and the beam-vector angle corrected flow velocity (the actual flow velocity). In this study, an annular array transducer was used to generate a conical-shaped and symmetrically focused ultrasound beam to measure the flow velocity vectors parallel and perpendicular to the ultrasound beam axis. The beam-vector angle and flow velocity is calculated from the mode frequency (f(d)) and the maximum Doppler frequency (f(max)) of the Doppler spectrum. We develop a spectrum normalization algorithm to enable the Doppler spectrum averaging using the spectra obtained within a single cardiac cycle. The Doppler spectrum averaging process reduces the noise level in the Doppler spectrum and also enables the calculation of the beam-vector angle and flow velocity for pulsatile flows to be measured. We have verified the measurement method in vivo over a wide range of angles, from 52 degrees to 80 degrees, and the standard deviations of the measured beam-vector angles and flow velocities in the carotid artery are lower than 2.2 degrees and 12 cm/s (about 13.3%), respectively.