Shunt quantification in congenital heart disease based on two-dimensional speckle tracking

In this work we investigated how high frame rate speckle tracking based on plane wave imaging could be used to improve the quantification of peak velocities in shunt flows due to septal defects. Simulated jet flow was used to optimize acquisition and tracking parameters. In vivo, a packet based acquisition scheme was used where focused B-mode scans were interleaved high frame rate flow images (100 fps). Results showed that speckle tracking provides calibrated velocities in the shunt flow throughout the cardiac cycle, and improved estimates of peak velocities used for diagnosing shunt severity were acquired

Ultrasound strain rate imaging of individual muscle motor units

Skeletal muscle is organized in motor units, each comprising a motor neuron and all its connected muscle fibres. The arrival of an action potential (a neural “impulse”) causes the fibers to contract, they exhibit a twitch. This study aimed for the spatiotemporal detection of individual twitches, which may allow for a more detailed real-time study of muscle physiology and higher fidelity in applications such as prosthesis control. We used a commercial ultrasound scanner and a linear probe in a clamped and fixed position over the biceps, with the image plane perpendicular to the muscle fibers. The strain rate scans were made with a frequency of 15MHz and a frame rate of approximately 215 FPS. Recordings of tiny voluntary isometric muscle contractions were made, with ElectroMyoGraphic (EMG) electrodes placed on each side of the probe to detect the Associated Motor Unit Action Potentials (MUAPs). The recordings were analyzed using the scanner’s Quantitative analysis (Q-analysis) tool for measuring strain rates within selected Regions Of Interest (ROIs). The results indicate that it is possible to image the mechanical response of a single motor unit by using ultrasonic strain rate imaging. This technique could thus be a future supplement to EMG in certain applications

Disabilities exhibited by children and adolescents that refuse to go to school

The aim of the study was to investigate what functional difficulties young people who refuse to go to school experience in their everyday lives. Research questions where what difficulties do young people who refuse to go to school experience? Are there differences between boys and girls? The study is a retrospective journal study with 28 Swedish youngsters based on Strengths & Difficulties Questionnaire (SDQ). Major findings where about somatic symptoms, emotional distress, loneliness, distinct gender roles, less mature and risk behavior. Although the school, social services and children- and adolescent psychiatry largely agree on the complexity of adolescents being absent from school, it seems difficult for the organizations to agree on adequate solutions.publishedVersio

Clutter filtering issues in speckle tracking for two-dimensional blood velocity estimation: a potential solution based on compounded imaging

Clutter filtering issues remains a major limitation in multi-dimensional blood velocity estimation. In this work we investigate how compounded plane wave imaging can be used to minimize clutter filtering issues when using speckle tracking for two-dimensional velocity estimation. By using a dual scan angle approach one can ensure a sufficient beam-to-flow angle for most imaging scenarios. Segmentation algorithms based on the estimated power and mean axial velocity were used to determine whether estimates were to be discarded or combined. The proposed setup was evaluated in a simulation study (Field II) for straight tube flow with parabolic flow profiles, and for a realistic CFD flow model of a carotid bifurcation. It was shown that the clutter filtering issues were significantly reduced when using compounded imaging and speckle tracking. Regions corrupted by the clutter filter in one scan was not corrupted in the other scan. Thus, consistent estimates could be obtained from the whole region of interest. In addition, the estimates were averaged and the variance reduced in regions where neither scan was corrupted. Regression analysis showed a 10-16 % decrease in standard deviation for the lateral velocity component and a 17 -19 % decrease for the axial component

Potential impact of texture analysis in contrast enhanced CT in non-small cell lung cancer as a marker of survival: A retrospective feasibility study

The objective of this feasibility study was to assess computed tomography (CT) texture analysis (CTTA) of pulmonary lesions as a predictor of overall survival in patients with suspected lung cancer on contrast-enhanced computed tomography (CECT). In a retrospective pilot study, 94 patients (52 men and 42 women; mean age, 67.2 ± 10.8 yrs) from 1 center with non-small cell lung cancer (NSCLC) underwent CTTA on the primary lesion by 2 individual readers. Both simple and multivariate Cox regression analyses correlating textural parameters with overall survival were performed. Statistically significant parameters were selected, and optimal cutoff values were determined. Kaplan-Meier plots based on these results were produced. Simple Cox regression analysis showed that normalized uniformity had a hazard ratio (HR) of 16.059 (3.861-66.788, P < .001), and skewness had an HR of 1.914 (1.330-2.754, P < .001). The optimal cutoff values for both parameters were 0.8602 and 0.1554, respectively. Normalized uniformity, clinical stage, and skewness were found to be prognostic factors for overall survival in multivariate analysis. Tumor heterogeneity, assessed by normalized uniformity and skewness on CECT may be a prognostic factor for overall survival

A Scoping Review of Cerebral Doppler Arterial Waveforms in Infants

Cerebral Doppler ultrasound has been an important tool in pediatric diagnostics and prognostics for decades. Although the Doppler spectrum can provide detailed information on cerebral perfusion, the measured spectrum is often reduced to simple numerical parameters. To help pediatric clinicians recognize the visual characteristics of disease-associated Doppler spectra and identify possible areas for future research, a scoping review of primary studies on cerebral Doppler arterial waveforms in infants was performed. A systematic search in three online bibliographic databases yielded 4898 unique records. Among these, 179 studies included cerebral Doppler spectra for at least five infants below 1 y of age. The studies describe variations in the cerebral waveforms related to physiological changes (43%), pathology (62%) and medical interventions (40%). Characteristics were typically reported as resistance index (64%), peak systolic velocity (43%) or end-diastolic velocity (39%). Most studies focused on the anterior (59%) and middle (42%) cerebral arteries. Our review highlights the need for a more standardized terminology to describe cerebral velocity waveforms and for precise definitions of Doppler parameters. We provide a list of reporting variables that may facilitate unambiguous reports. Future studies may gain from combining multiple Doppler parameters to use more of the information encoded in the Doppler spectrum, investigating the full spectrum itself and using the possibilities for long-term monitoring with Doppler ultrasound

Chest computed tomography features of heart failure:A prospective observational study in patients with acute dyspnea

BACKGROUND: Pulmonary congestion is a key component of heart failure (HF) that chest computed tomography (CT) can detect. However, no guideline describes which of many anticipated CT signs are most associated with HF in patients with undifferentiated dyspnea. METHODS: In a prospective observational single-center study, we included consecutive patients ≥ 50 years admitted with acute dyspnea to the emergency department. Patients underwent immediate clinical examination, blood sampling, echocardiography, and CT. Two radiologists independently evaluated all images. Acute HF (AHF) was adjudicated by an expert panel blinded to radiology images. LASSO and logistic regression identified the independent CT signs of AHF. RESULTS: Among 232 patients, 102 (44%) had AHF. Of 18 examined CT signs, 5 were associated with AHF (multivariate odds ratio, 95% confidence interval): enlarged heart (20.38, 6.86–76.16), bilateral interlobular thickening (11.67, 1.78–230.99), bilateral pleural effusion (6.39, 1.98–22.85), and increased vascular diameter (4.49, 1.08–33.92). Bilateral ground-glass opacification (2.07, 0.95–4.52) was a consistent fifth essential sign, although it was only significant in univariate analysis. Eighty-eight (38%) patients had none of the five CT signs corresponding to a 68% specificity and 86% sensitivity for AHF, while two or more of the five CT signs occurred in 68 (29%) patients, corresponding to 97% specificity and 67% sensitivity. A weighted score based on these five CT signs had an 0.88 area under the curve to detect AHF. CONCLUSIONS: Five CT signs seem sufficient to assess the risk of AHF in the acute setting. The absence of these signs indicates a low probability, one sign makes AHF highly probable, and two or more CT signs mean almost certain AHF