Measures of divergence of oriented patterns for the detection of architectural distortion in prior mammograms

Purpose We propose a method for the detection of architectural distortion in prior mammograms of interval-cancer cases based on the expected orientation of breast tissue patterns in mammograms. Methods The expected orientation of the breast tissue at each pixel was derived by using automatically detected landmarks including the breast boundary, the nipple, and the pectoral muscle (in mediolateral-oblique views). We hypothesize that the presence of architectural distortion changes the normal expected orientation of breast tissue patterns in a mammographic image. The angular deviation of the oriented structures in a given mammogram as compared to the expected orientation was analyzed to detect potential sites of architectural distortion using a measure of divergence of oriented patterns. Each potential site of architectural distortion was then characterized using measures of spicularity and angular dispersion specifically designed to represent spiculating patterns. The novel features for the characterization of spiculating patterns include an index of divergence of spicules computed from the intensity image and Gabor magnitude response using the Gabor angle response; radially weighted difference and angle-weighted difference (AWD) measures of the intensity, Gabor magnitude, and Gabor angle response; and AWD in the entropy of spicules computed from the intensity, Gabor magnitude, and Gabor angle response. Results Using the newly proposed features with a database of 106 prior mammograms of 56 interval-cancer cases and 52 mammograms of 13 normal cases, through feature selection and pattern classification with an artificial neural network, an area under the receiver operating characteristic curve of 0.75 was obtained. Free-response receiver operating characteristic analysis indicated a sensitivity of 0.80 at 5.3 false positives (FPs) per patient. Combining the features proposed in the present paper with others described in our previous works led to significant improvement with a sensitivity of 0.80 at 3.7 FPs per patient. Conclusion The proposed methods can detect architectural distortion in prior mammograms taken 15 months (on the average) before clinical diagnosis of breast cancer, but the FP rate needs to be reduced.     

Ultrasound Findings of Delayed‐Onset Muscle Soreness

The purpose of this series was to retrospectively characterize the ultrasound findings of delayed‐onset muscle soreness (DOMS). The Institutional Review Board approved our study, and informed consent was waived. A retrospective search of radiology reports using the key phrase “delayed‐onset muscle soreness” and key word “DOMS” from 2001 to 2015 and teaching files was completed to identify cases. The sonograms were reviewed by 3 fellowship‐trained musculoskeletal radiologists by consensus. Sonograms were retrospectively characterized with respect to echogenicity (hypoechoic, isoechoic, or hyperechoic), distribution of muscle involvement, and intramuscular pattern (focal versus diffuse and well defined versus poorly defined). Images were also reviewed for muscle enlargement, fluid collection, muscle fiber disruption, and increased flow on color or power Doppler imaging. There were a total of 6 patients identified (5 male and 1 female). The average age was 22 years (range, 7–44 years). Of the 6 patients, there were a total of 11 affected muscles in 7 extremities (1 bilateral case). The involved muscles were in the upper extremity: triceps brachii in 27% (3 of 11), biceps brachii in 18% (2 of 11), brachialis in 18% (2 of 11), brachioradialis in 18% (2 of 11), infraspinatus in 9% (1 of 11), and deltoid in 9% (1 of 11). On ultrasound imaging, the abnormal muscle was hyperechoic in 100% (11 of 11), well defined in 73% (8 of 11), poorly defined in 27% (3 of 11), diffuse in 73% (8 of 11), and focal in 27% (3 of 11). Increased muscle size was found in 82% (9 of 11) and minimal hyperemia in 87.5% (7 of 8). The ultrasound findings of DOMS include hyperechoic involvement of an upper extremity muscle, most commonly appearing well defined and diffuse with increased muscle size and minimal hyperemia.     

肝动脉动态声学造影对肝内实质性占位病变诊断的研究

本文报道了采用泛影葡胺对３０例肝脏肿瘤进行肝动脉动态声学造影的声像图结果。根据病变区与周围组织的回声变化，声像图结果可分为三型，Ａ型：病变区快进快出的增强呈“满天星征”，在２２例原发性肝癌中有１９例显示此征，占８６％；Ｂ型：病灶区边缘结节状强化，并向中心扩散，在５例肝海绵状血管瘤中见于４例；Ｃ型：病灶周边回声增强，见于肝转移癌３例及巨块型肝癌１例。此外我们还分析了声像图结果与病理的联系，并指出这种超声造影的方法弥补了Ｘ线血管造影与彩色多普勒血流显像（ＣＤＦＩ）中的一些不足之处。     

探头扫查平面与肌纤维走行方向夹角对剪切波传播速度的影响

目的 探讨探头扫查平面与肱二头肌肌纤维走行方向夹角对剪切波传播速度的影响。方法 随机选取健康志愿者20名。采用实时剪切波弹性成像技术, 探头方向与肌纤维方向夹角分别为0°、30°、60°、90°,测量距体表深度1.7 cm、2.5 cm处同一位点的剪切波传播速度,并进行统计学分析。结果 深度为1.7 cm和2.5 cm,剪切波传播方向与肌纤维夹角为0°、30°、60°、90°时,剪切波传播速度差异均有统计学意义(P均<0.05)。分别取剪切波方向与人体肌纤维排列的夹角为0°、30°、60°、90°时,不同深度剪切波传播速度差异无统计学意义(P均>0.05)。结论 探头扫查平面与肌纤维走行方向夹角影响剪切波的传播速度,深度相同时,随着剪切波传播方向与人体肌纤维排列方向夹角增大,剪切波速度有递减趋势。传播方向一致时,剪切波在人体肱二头肌中的传播速度与深度无明显关系。     

Utility of a screening examination of the fetal extremities during obstetrical sonography

The hands, feet, and long bones of the extremities were visualized and an image of the femur was obtained as part of a brief fetal anatomy survey during approximately 6,700 low-risk and high-risk obstetric sonograms. This examination identified four fetuses with five instances of isolated extremity abnormalities and nine fetuses with ten instances of generalized extremity abnormalities. Isolated abnormalities included malformation or complete or partial absence of an extremity. Generalized abnormalities included fused hands and feet, polydactyly, phocomelia, hyperechoic muscle with contractures, and several varieties of dwarfism. Most fetuses had other structural abnormalities as well and two had an abnormal family history. The sensitivity of the fetal anatomy survey for the detection of extremity malformations would not have been changed if the routine femur measurement had been retained but the systematic visualization of the fetal extremities had been done only in selected fetuses with a malformation of any kind or an abnormal family history.     

Modulation of excitability in the cerebral cortex projecting to upper extremity muscles by rotational positioning of the forearm

The forearm rotation changes sensory inputs to the central nervous system, thereby providing orientation of the hand for grasping an object. Electrical activities of the muscles, induced by transcranial magnetic stimulation to the brain, i.e., motor evoked potentials (MEPs), are used for estimation of the excitability of motor neurons in the brain and spinal cord. It is well known that rotational positioning of the forearm influences MEPs of forearm muscles through modulation of excitability in the central nervous system. In the present study, we investigated whether such a posture-dependent change of MEPs could be found in upper arm and intrinsic hand muscles at three different rotational forearm positions: the most internal (pronation), neutral, and most external (supination) positions of rotation. MEPs were simultaneously recorded from the four muscles, biceps brachii (BB), triceps brachii (TB), abductor digiti minimi (ADM), and abductor pollicis brevis (AbPB). MEP amplitudes and latencies in BB, TB and ADM were significantly larger and shorter, respectively, in supination compared to the values in other positions. By contrast, MEP of AbPB in supination was lower in amplitude and longer in latency. Importantly, muscle lengths of TB, ADM and AbPB are constant in any rotational forearm positions, excluding the possibility of the muscle-length dependent change of spinal reflex. Therefore, these results might be attributable to the posture-dependent modulation of the motor cortex activity for the upper limb. The motor cortex probably changes the control strategy for the upper limb muscles in accordance with the sensory input from the forearm.     

Exteroceptive aspects of nociception: Insights from graphesthesia and two-point discrimination

The exteroceptive capabilities of the nociceptive system have long been thought to be considerably more limited than those of the tactile system. However, most investigations of spatio-temporal aspects of the nociceptive system have largely focused on intensity coding as consequence of spatial or temporal summation.Graphesthesia, the identification of numbers “written” on the skin, and assessment of the two-point discrimination thresholds were used to compare the exteroceptive capabilities of the tactile and nociceptive systems. Numbers were “written” on the forearm and the abdomen by tactile stimulation and by painful non-contact infrared laser heat stimulation. Subjects performed both graphesthesia tasks better than chance. The tactile graphesthesia tasks were performed with 89% (82-97%) correct responses on the forearm and 86% (79-94%) correct responses on the abdomen. Tactile graphesthesia tasks were significantly better than painful heat graphesthesia tasks that were performed with 31% (23-40%) and 44% (37-51%) correct responses on the forearm and abdomen, respectively. These findings demonstrate that the central nervous system is capable of assembling complex spatio-temporal patterns of nociceptive information from the body surface into unified mental objects with sufficient accuracy to enable behavioral discrimination.     

Muscular Echovariation: A New Biomarker in Amyotrophic Lateral Sclerosis

The purpose of the work described here was to assess the characteristics of echovariation in amyotrophic lateral sclerosis (ALS) compared with other muscle ultrasonography parameters. Twenty-six ALS patients (8 women, mean age 58.9 y, standard deviation 12.02 y) and 26 healthy controls (17 women, mean age 59.6 y, standard deviation 6.41 y) were included in this observational study. They underwent bilateral and transverse ultrasound of the biceps/brachialis, forearm flexor group, quadriceps femoris and tibialis anterior. Muscular thickness, echo-intensity and echovariation were analyzed. Muscles affected by ALS had increased echo-intensity, decreased thickness and decreased echovariation. Echovariation in all muscles except the quadriceps femoris strongly correlated with muscle strength (explained variance between 21.8% in the biceps/brachialis and 37.5% in the tibialis anterior) and the ALS Functional Rating Scale Revised score (explained variance between 26% in the biceps/brachialis and 36.7% in the forearm flexor group). Echovariation is an easy-to-obtain quantitative muscle ultrasonography parameter that could distinguish ALS patients from healthy controls more accurately than previous described biomarkers.     

Quantitative muscle ultrasonography in amyotrophic lateral sclerosis

In this study, we examined whether quantitative muscle ultrasonography can detect structural muscle changes in early-stage amyotrophic lateral sclerosis (ALS). Bilateral transverse scans were made of five muscles or muscle groups (sternocleidomastoid, biceps brachii/brachialis, forearm flexor group, quadriceps femoris and anterior tibialis muscles) in 48 patients with ALS. Twenty-five patients were also screened for fasciculations. Quantitative analysis revealed a significant increase in echo intensity in all muscles and a decrease in muscle thickness of the biceps brachii, forearm flexors and quadriceps femoris on both sides. Fasciculations were easy to detect in multiple muscles of all screened patients except one. We conclude that quantitative ultrasonography can be used to detect muscle changes caused by ALS in an early phase of the disease. (E-mail: m.zwarts@neuro.umcn.nl).     

Average sound speed estimation using speckle analysis of medical ultrasound data

Purpose

Most ultrasound imaging systems assume a pre-determined sound propagation speed for imaging. However, a mismatch between assumed and real sound speeds can lead to spatial shift and defocus of ultrasound image, which may limit the applicability of ultrasound imaging. The estimation of real sound speed is important for improving positioning accuracy and focus quality of ultrasound image.

Method

A novel method using speckle analysis of ultrasound image is proposed for average sound speed estimation. Firstly, dynamic receive beam forming technology is employed to form ultrasound images. These ultrasound images are formed by same pre-beam formed radio frequency data but using different assumed sound speeds. Secondly, an improved speckle analysis method is proposed to evaluate focus quality of these ultrasound images. Thirdly, an iteration strategy is employed to locate the desired sound speed that corresponds to the best focus quality image.

Results

For quantitative evaluation, a group of ultrasound data with 20 different structure patterns is simulated. The comparison of estimated and simulated sound speeds shows speed estimation errors to be ?0.7 ± 2.54?m/s and ?1.30 ±?5.15?m/s for ultrasound data obtained by 128- and 64-active individual elements linear arrays, respectively. Furthermore, we validate our method via phantom experiments. The sound speed estimation error is ?1.52 ± 8.81?m/s.

Conclusion

Quantitative evaluation proves that proposed method can estimate average sound speed accurately using single transducer with single scan.     

Estimation of individual axon bundle properties by a Multi-Resolution Discrete-Search method

A stable, accurate and robust-to-noise method for the estimation of the intra-voxel bundle-wise diffusion properties for diffusion-weighted magnetic resonance imaging is presented. The proposed method overcomes some of the limitations of most of the multi-fiber algorithms in the literature and extends them to estimate the diffusion profiles, improving the estimation of the intra-voxel geometry at challenging microstructure configurations, that is to say: relatively small crossing angles, different voxel-wise anisotropic diffusion profiles and low SNR. The proposed methodology is based on four key novel ideas: (i) A Multi-Resolution Discrete-Search determines the orientation of the fiber bundles accurately and naturally constrains the sparsity on the recovered solutions; (ii) the determination of the number of fiber bundles using the F-test combined with a Rician bias correction; (iii) a Simultaneous Denoising and Fitting procedure that exploits the spatial redundancy of the axon bundles to achieve robustness with respect to noise; and (iv) a general framework for the estimation of the axial and radial diffusivity parameters independently for each voxel. A new useful evaluation metric is also proposed, which combines the information of the success rate in the estimated number of bundles and the angular error, avoiding in this way, some of the limitations these metrics have individually. A novel methodology for the evaluation of the methods on in-vivo data is also proposed. This work presents an extensive evaluation: the proposed methodology has been tested on state-of-the-art biophysical synthetic data for a variety of conditions, on the challenging spatially coherent phantom used on the HARDI reconstruction Challenge 2012, and on the recently released in-vivo MASSIVE data-set. Our results present significant improvements on the estimation of the number and orientation of the fiber bundles over the Spherical Deconvolution algorithm for multi-shell data, which is one of the most widely used multi-fiber algorithm. The results also show that, by the voxel-wise estimation of the diffusion profiles, the axial and radial diffusivity parameters are robustly estimated, being this essential for a better understanding of the individual bundle diffusion properties at challenging structural configurations.     

High-frequency endoluminal ultrasonography of the esophagus in human autopsy specimens

A 20 MHz ultrasound transducer housed in a 6.2 Fr catheter was used to image human esophageal autopsy specimens from six cadavers. Histologic sections taken from the areas imaged were correlated with cross-sectional sonographic images. Six echo layers were seen in the non-fluid-filled esophagus whereas seven echo layers were seen in the fluid-filled esophagus. These seven layers correspond to the following histologic structures: first hyperechoic layer--mucosa (including squamous epithelium and lamina propria); second thin hypoechoic layer--muscularis mucosae; third very bright hyperechoic layer--submucosa; fourth hypoechoic layer--circular smooth muscle; fifth thin hyperechoic layer--intermuscular connective tissue; sixth hypoechoic layer--longitudinal smooth muscle; seventh hyperechoic layer--adventitia.     

Feature-based non-parametric estimation of Kullback–Leibler divergence for SAR image change detection

In this article, a method based on a non-parametric estimation of the Kullback–Leibler divergence using a local feature space is proposed for synthetic aperture radar (SAR) image change detection. First, local features based on a set of Gabor filters are extracted from both pre- and post-event images. The distribution of these local features from a local neighbourhood is considered as a statistical representation of the local image information. The Kullback–Leibler divergence as a probabilistic distance is used for measuring the similarity of the two distributions. Nevertheless, it is not trivial to estimate the distribution of a high-dimensional random vector, let alone the comparison of two distributions. Thus, a non-parametric method based on k-nearest neighbour search is proposed to compute the Kullback–Leibler divergence between the two distributions. Through experiments, this method is compared with other state-of-the-art methods and the effectiveness of the proposed method for SAR image change detection is demonstrated.     

Estimation of the velocity of a moving ground target using a SAR System,based on a modified multiple-measurement vector model

A velocity estimation method of ground moving target with sparse sampling data is proposed in this letter. Firstly, the moving target echo signal is converted to squinted synthetic aperture radar (SAR) received signal. Then, a modified multiple-measurement vector (MMV) model is built to obtain the sparse representation of ground moving target, and the improved orthogonal matching pursuit (OMP) algorithm (range migration OMP, RM-OMP) is utilized to reconstruct the coarse image of moving target. Finally, the azimuth- and range-velocity of moving target can be estimated simultaneously by searching all the possible velocity such that the minimum-entropy of coarse image is reached. Different from the homologous velocity estimation methods, the proposed method can obtain accurate estimation with signals sampled below the Nyquist rate. And benefits from the multiple measurements, the proposed method can produce better estimation accuracy and less computational complexity than the single measurement vector (SMV)-based method. The simulated data processing results validate the effectiveness of the proposed method.     

Adaptation de la force isocinétique des muscles rotateurs de l’épaule à la pratique sportive

Physiological, anatomy and biomechanical adaptations of the shoulder joint to the stresses induced by the throwing gesture, which allow performance, could be the cause of “desadaptation” that can lead to injury by microtrauma. Thus, exploration of any adaptations or changes in internal (IR) and external (ER) muscle strength (and/or agonist/antagonist balance represented by the ratio ER/IR) to solicitations sports is relevant in order to better understand the pathophysiology of shoulder injury. Many studies have focused on identifying patterns of IR and ER muscle strength according to the practice of overhead sports. Despite the methodological limitations, although an increase in the IR strength of the dominant side was reported, it does not seem to exist an “imbalance” in muscle strength between the IR and ER, induced by overhead sports, which could be a “desadaptaion” in the origin of shoulder pathologies. There is no imbalance that could be implicated as a risk factor predisposing to shoulder pathologies.     

Imaging myocardial fiber orientation using polarization sensitive optical coherence tomography

Knowledge of myocardial fiber architecture is essential towards understanding heart functions. We demonstrated in this study a method to map cardiac muscle structure using the local optical axis obtained from polarization-sensitive optical coherence tomography (PSOCT). An algorithm was developed to extract the true local depth-resolved optical axis, retardance, and diattenuation from conventional round-trip results obtained in a Jones matrix-based PSOCT system. This method was applied to image the myocardial fiber orientation in a bovine heart muscle sample.OCIS codes: (110.4500) Optical coherence tomography, (230.5440) Polarization-selective devices     

Effect of warning signal on reaction time and EMG activity of the biceps brachii muscle in elbow flexion and forearm supination

Using a reaction time (RT) task, the biceps brachii muscle was investigated in five healthy subjects to determine whether EMG in the initial phase of activity is dependent upon the direction of movement, i.e., elbow flexion and forearm supination, and/or influenced by the presence or absence of warning signal. Results showed that in the presence of warning EMG-RT of forearm supination was faster than that of elbow flexion, and that the reverse occurred in the absence of warning. The warning signal significantly reduced EMG-RT of both movements and the reduction of EMG-RT was larger in supination than flexion. Compared to forearm supination, large amplitude potentials were observed during elbow flexion. The warning suppressed EMG activities of both movements within 30 msec after their initiation. The present study indicates that the biceps brachii muscle exhibits a motor response program specific to the direction of movements and that preparatory set conditioned by warning shortens RT and also suppresses EMG activities.     

Various sonographic patterns of smooth muscle tumors of the gastrointestinal tract: a comparison with computed tomography.

To evaluate the sonographic patterns of smooth muscle tumors of the gastrointestinal tract, we analyzed 25 patients with histologically confirmed smooth muscle tumors. Sonography revealed no abdominal mass in seven patients (sonogram-negative), and abdominal masses in 18 patients (sonogram-positive). The mean size of tumors in the sonogram-negative group (4.5 +/- 1.5 cm) was smaller than that in the sonogram-positive group (11.4 +/- 3.5 cm). We classified the various sonograms into three patterns. Comparing the sonograms with the computed tomographic pictures of each pattern, we theorized that the different patterns on sonograms may be caused by tumor necroses of different sizes with or without gas in the necrotic cavity. For the necrotic tumors, the size of the necrotic area did not correspond to the size of the tumor. However, the tumors with necroses were significantly larger than those without necroses. A central necrosis was found in cases exhibiting both leiomyosarcoma and leiomyoma. On comparing the sonogram-positive and sonogram-negative groups, we found that the size and location of a tumor may affect the detection rate of that tumor by sonography.     

The development of ultrashort acting neuromuscular relaxant tropane derivatives

There is a need for neuromuscular relaxant (NMR) agents that are of the “nondepolarizing type” and produce rapidly developing and short-lasting skeletal muscle relaxation in anesthesiology. Many efforts have been directed to produce such agents. Our research focused on the design, synthesis, and evaluation of numerous “bisquaternary” derivatives of the cyclic aminoalkanes: tropane and granatane. Through systematic “steric structure-activity relationship” studies, we arrived at some new bisquaternary tropine and granatanol diesters, which in laboratory studies appeared to be the fastest and shortest acting NMRs recognized so far. Their ultrashort duration action-mechanism was, however, linked to the formation of nephrotoxic metabolites, precluding further development. Even so, we believe that the scientific information gained from more than a thousand such agents, will be useful toward developing the “ideal,” ultrashort-acting NMR that could be clinically successful without the use of “reversing” agents, at least until “new biotechnology” may solve all problematic aspects of “transient” muscle relaxation.     

肝实性占位超声加声特性的病理基础

目的 了解决定肝实性占位病变超声回声特性的病理组织学基础。方法 １２０例患者的３７个高回声结节、９１个低怕结节在超声引导下接受穿刺组织活检,并进行病理组织学分析。结果 １２８个结节中包含了各种良、恶性病变。高回声的共同组织学特点为：含腓 液化性坏死区、脂肪空泡、透明细胞、血窦或周隙扩张,上述结构的最小径〉０．０３ｍｍ且大片融合形成直径〉０．４０ｍｍ的集落簇。回声病灶细胞排列致密无上述结构。结论病灶