Subsegmental Levels Research Articles

Exploration of temporal dynamics of frequency domain linear prediction cepstral coefficients for dialect classification

Speakers exhibit dialectal traits in speech at sub-segmental, segmental, and supra-segmental levels. Any feature representation for dialect classification should appropriately represent these dialectal traits. Traditional segmental features such as mel-frequency cepstral coefficients (MFCCs) fail to represent sub-segmental and supra-segmental dialectal traits. This study proposes to use frequency domain linear prediction cepstral coefficients (FDLPCCs) for dialect classification inspired by its long temporal summarization during pole estimation. The i-vectors and x-vectors derived from both baseline (MFCCs, linear prediction cepstral coefficients (LPCCs), perceptual LPCCs (PLPCCs), RASTA filtered PLPCCs (PLPCC-R) and proposed (FDLPCC) features are used for identifying the dialects with support vector machine (SVM) and feed-forward neural network (FFNN) as classifiers. Proposed FDLPCC features have shown to perform better than baseline features such as MFCCs and PLPCC-Rs (best among LPCCs variants) by an absolute improvement of 3.4% and 3.9% (in unweighted average recall (UAR)), with i-vector + SVM system and 1.6% and 4.6% (in UAR), i-vector + FFNN system respectively. It is also found that there exists a complementary information between the proposed and baseline features. Furthermore current studies are compared with previous studies and it is found that performances of current studies are better than previous studies.

Accelerated Stack-of-Spirals Free-Breathing Three-Dimensional Ultrashort Echo Time Lung Magnetic Resonance Imaging: A Feasibility Study in Patients With Breast Cancer.

PurposeTo investigate the clinical feasibility of accelerated free-breathing stack-of-spirals (spiral) three-dimensional (3D) ultrashort echo time (UTE) lung magnetic resonance imaging (MRI) using iterative self‐consistent parallel imaging reconstruction from arbitrary k‐space (SPIRiT) algorithm in patients with breast cancer.MethodsThe institutional review board approved this prospective study and patients’ informed consents were obtained. Between June and August 2018, 29 female patients with breast cancer underwent 3-T MRI including accelerated free-breathing spiral 3D UTE (0.98-mm isotropic spatial resolution; echo time, 0.05 msec) of the lungs and thin-section chest computed tomography (CT). Two radiologists evaluated the image quality and pulmonary nodules on MRI were assessed and compared, CT as a reference.ResultsThe pulmonary vessels and bronchi were visible consistently up to the sub-sub-segmental and sub-segmental branch levels, respectively, on accelerated spiral 3D UTE. The overall image quality was evaluated as good and excellent for 70.7% of accelerated spiral 3D UTE images (reviewer [R]1, 72.4% [21/29]; R2, 69.0% [20/29]) and acceptable for 20.7% (both R1 and R2, 20.7% [6/29]). Five patients on CT revealed 141 pulmonary metastatic nodules (5.3 ± 2.6 mm); the overall nodule detection rate of accelerated spiral 3D UTE was sensitivity of 90.8% (128/141), accuracy of 87.7%, and positive predictive value of 96.2%. In the Bland-Altman plot analysis comparing nodule size between CT and MRI, 132/141 nodules (93.6%) were inside the limits of agreement.ConclusionAccelerated free-breathing spiral 3D UTE using the SPIRiT algorithm could be a potential alternative to CT for oncology patients.

Motion Reduction for C-Arm Computed Tomography of the Pulmonary Arteries: Image Quality of a Motion Correction Algorithm in Patients with Chronic Thromboembolic Hypertension During Balloon Pulmonary Angioplasty.

To evaluate the feasibility and image quality of a motion correction algorithm for supra-selective C-arm computed tomography (CACT) of the pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing balloon pulmonary angioplasty (BPA). CACT raw data acquired during 30consecutive BPAs were used for image reconstruction using either standard (CACTorg) or a motion correction algorithm (CACTmc), using 400 iterations. Two readers independently evaluated 188 segmental and 564 sub-segmental contrast-enhanced pulmonary arteries in each reconstruction. The following categories were assessed: Sharpness of the vessel, motion artifacts, delineation of bronchial structures, vessel geometry, and visibility of treatable lesions. The mentioned criteria were rated from grade 1 to grade 3: grade 1: excellent quality; grade 2: good quality; grade 3: poor/seriously impaired quality. Inter-observer agreement was calculated using Cohen's Kappa. Due to an excellent agreement, the ratings of both readers were merged. Differences in the assessed image quality criteria were evaluated using pairwise Wilcoxon signed-rank test. Inter-observer agreement was excellent for all evaluated image quality criteria (κ > 0.81). For all assessed image quality criteria, the ratings on CACTorg were good but improved significantly for CACTmc to excellent for the whole vascular tree (p < 0.01). When considering segmental and sub-segmental levels individually, all image quality criteria improved significantly for CACTmc on both levels (p < 0.01). While ratings of CACTmc were constant for both levels (segmental and sub-segmental) for all criteria, the ratings of CACTorg were slightly impaired for the sub-segmental arteries. Motion correction for supra-selective contrast-enhanced CACT of the pulmonary arteries is feasible and improves the overall image quality. · Motion artifacts can severely impair the diagnostic accuracy of CACT.. · A motion correction algorithm can significantly improve image quality in CACT of the pulmonary arteries.. · Especially the overall image quality of sub-segmental branches is significantly improved.. · Maschke S, Werncke T, Becker LS et al. Motion Reduction for C-Arm Computed Tomography of the Pulmonary Arteries: Image Quality of a Motion Correction Algorithm in Patients with Chronic Thromboembolic Hypertension During Balloon Pulmonary Angioplasty. Fortschr Röntgenstr 2021; 193: 1074 - 1080.

COVID-19 Viral Pneumonia Complicated with Acute Pulmonary Embolism: A Descriptive Study.

Objective To evaluate acute pulmonary embolism in patients with 2019 novel coronavirus (COVID-19) pneumonia using pulmonary CT angiography. Subjects and Methods. From 95 symptomatic patients confirmed with COVID-19 by RT-PCR from 1 May to 14 July 2020 in Dallah Hospital, Riyadh, Saudi Arabia, CT angiography was done for 25 patients suspected to have pulmonary embolism and have no contraindication for contrast study. 11 cases of them showed CT evidence of acute pulmonary embolism (PE). Retrospectively, CT angiography was analyzed and detailed findings were recorded. This study was approved by the Institutional Review Board of our hospital, and the patient consent was waived. Results The mean age of the included patients was 49 ± 11 years; the youngest was 22 years, and the oldest was 64 years. Common symptoms in the 25 cases that underwent CT angiography were fever that was noted in 21/25 cases (84%), shortness of breath in 18/25 cases (72%), cough in 16/25 cases (64%), and severe myalgia/body fatigue in 13/25 cases (52%). The less common symptoms were sore throat in 11/25 cases (44%) and headache in 10/25 cases (40%). Regarding CT findings, 4/25 cases (16%) had unilateral lung disease and 21/25 cases (84%) had bilateral disease, with slight predilection for the right lower lobe (10/25 cases, 40%). Pure ground-glass opacity (GGO) was seen in 13/25 cases (52%), and GGO with consolidation was seen in 12/25 cases (48%). Common accompanying CT signs included crazy paving stone sign in 15/25 cases (60%) and air bronchogram in 12/25 cases (48%). From the 25 patients that showed respiratory deterioration and elevated serum D-dimer level, 11 cases confirmed to have acute pulmonary embolism, while 14 cases showed negative result for pulmonary embolism. 6/11 were male and 5/11 were female. Pulmonary embolism was diagnosed at a mean of 21 days from symptom onset. Unilateral acute pulmonary embolism was seen in 3/11 cases, while 8/11 cases showed bilateral distribution. Among 11 cases with acute pulmonary embolism, no emboli at the central level could be seen, but 3 cases showed pulmonary embolism at the lobar level, 3 cases at the segmental level, and 5 cases at lobar, segmental, and subsegmental levels. Conclusion In patients with confirmed COVID-19, we should maintain a high suspicion for its thromboembolic complications such as acute pulmonary embolism that was mainly diagnosed at the end of 3rd week from symptom onset. We suggest that whenever a CT evaluation of the parenchymal involvement of COVID-19 pneumonia is performed, a simultaneous evaluation of the pulmonary arteries is also essential in order to identify early signs of associated pulmonary embolism.

Varia: Функционална субституция между орална и носова гласна (френски – български език)

This paper analyzes some cases of functional substitution of an oral vowel for a nasal one in the spoken varieties of French and Bulgarian, as well as in some varieties of French which are as spoken outside France. Other subjects of research include cases of functional replacement of a nasal vowel for an oral one in the spoken variety of French and its variants. The purpose of the study is not only to describe the observed processes, but also to identify their causes at the subsegmental, segmental and suprasegmental levels.

Complex Pulmonary Artery Reconstruction

Complex Pulmonary Artery Reconstruction evolved through our long-term clinical experience in the surgical management of patients with major aortopulmonary collateral arteries. A midline sternotomy approach, utilizing novel techniques for exposure and mobilization, enables access to the distal pulmonary artery tree to the segmental and subsegmental levels. This allows reconstructive procedures to address both discrete stenoses and areas of long-segment hypoplasia, to reduce pulmonary hypertension and improve and/or preserve right ventricular function. We have utilized this technique in over 70 patients, with our most recent analysis demonstrating one operative mortality, no operative reintervention, and improvement in right to left ventricular pressure ratio from 0.94 (0.72-1.30) to 0.36 (0.19-0.54) with durable 4 ± 3 year follow-up.

Implicit processing of LP residual for language identification

Present work explores the excitation source information for the language identification (LID) task. In this work, excitation source information is captured by implicit processing of linear prediction (LP) residual signal for discriminating the languages. Raw samples of LP residual signal, its magnitude, and phase components are processed independently at sub-segmental, segmental and suprasegmental levels for extracting the language-specific excitation source information. The LID studies are carried out using 27 Indian languages from Indian Institute of Technology Kharagpur-Multi Lingual Indian Language Speech Corpus (IITKGP-MLILSC) and 11 international languages from OGI-MLTS corpus. The Gaussian mixture models (GMMs) are used in this work to model the language-specific excitation source information for LID task. From the experimental results, it can be observed that, features extracted from segmental level yields better identification accuracy (50.92%), compared to sub-segmental (47.77%) and suprasegmental levels (43.88%). Further, the evidence from all three levels is combined to obtain the complete excitation source information. Finally, we have investigated the existence of non-overlapping language-specific information present in excitation source and vocal tract features.

Parametric representation of excitation source information for language identification

In this work, the linear prediction (LP) residual signal has been parameterized to capture the excitation source information for language identification (LID) study. LP residual signal has been processed at three different levels: sub-segmental, segmental and supra-segmental levels to demonstrate different aspects of language-specific excitation source information. Proposed excitation source features have been evaluated on 27 Indian languages from Indian Institute of Technology Kharagpur-Multi Lingual Indian Language Speech Corpus (IITKGP-MLILSC), Oregon Graduate Institute Multi-Language Telephone-based Speech (OGI-MLTS) and National Institute of Standards and Technology Language Recognition Evaluation (NIST LRE) 2011 corpora. LID systems were developed using Gaussian mixture model (GMM) and i-vector based approaches. Experimental results have shown that segmental level parametric features provide better identification accuracy (62%), compared to sub-segmental (40%) and supra-segmental level (34%) features. Excitation source features obtained from three levels show distinct language-specific evidence. Therefore, the scores from all three levels are combined to obtain the complete excitation source information for the LID task. LID performances achieved from both the excitation source and vocal tract system are compared. Finally, the scores obtained by processing the vocal tract and excitation source features are combined to achieve better improvement in LID accuracy. The best recognition accuracies obtained from stage-IV integrated LID systems I, II and III are 69%, 70% and 72% respectively.

Contrast in Phonology, 1867–1967: History and Development

This article surveys the history of contrast in phonology from Bell's Visible Speech ( 1867 ) until Chomsky &amp; Halle's Sound Pattern of English ( 1968 ). Phonological contrast can be viewed at the segmental and subsegmental (feature) levels. As contrast at the segmental level involves the phoneme, whose later history has been extensively documented, I concentrate on the origins of the concept in the work of Sweet. Subsequently, I focus on subsegmental-level contrast. After a look at its treatment in phonological analyses that operated without an explicit theory of features, I turn to Trubetzkoy, in whose work we find the seeds of later approaches. The article explores the foundations of the main methods of computing contrastive features: minimal differences and hierarchical feature ordering. It concludes with a discussion of contrast in early generative phonology and reviews some of the reasons for its decline at the end of the 1960s.

Implicit excitation source features for robust language identification

In present work, the robustness of excitation source features has been analyzed for language identification (LID) task. The raw samples of linear prediction (LP) residual signal, its magnitude and phase components are processed at sub-segmental, segmental and supra-segmental levels for capturing the robust language-specific phonotactic information. Present LID study has been carried out on 27 Indian languages from Indian Institute of Technology Kharagpur-Multi Lingual Indian Language Speech Corpus (IITKGP-MLILSC). Gaussian mixture models are used to develop the LID systems using robust language-specific excitation source information. Robustness of excitation source information has been evinced in view of (i) background noise, (ii) varying amount of training data and (iii) varying length of test samples. Finally, the robustness of proposed excitation source features is compared with the well-known spectral features using LID performances obtained from IITKGP-MLILSC database. Segmental level excitation source features obtained from raw samples of LP residual signal and its phase component perform better at low SNR levels, compared with the vocal tract features.

Computed Tomography Assessment of Airways Throughout Bronchial Tree Demonstrates Airway Narrowing in Severe Asthma

To analyze airway dimensions throughout the bronchial tree in severe asthmatic patients using multidetector row computed tomography (MDCT) focusing on airway narrowing. Thirty-two patients with severe asthma underwent automated (BronCare software) analysis of their right lung bronchi, with counts of airways >3 mm long arising from the main bronchi (airway count) and bronchial dimension quantification at segmental and subsegmental levels (lumen area [LA], wall area [WA], and WA%). Focal bronchial stenosis was defined as >50% narrowing of maximal LA on contiguous cross-sectional slices. Severe asthmatics were compared to 13 nonsevere asthmatic patients and nonasthmatic (pooled) subjects (Wilcoxon rank tests, then stepwise logistic regression). Finally, cluster analysis of severe asthmatic patients and stepwise logistic regression identified specific imaging subgroups. The most significant differences between severe asthmatic patients and the pooled subjects were bronchial stenosis (subsegmental and all bronchi: P < .002) and WA% (P < .0003). Stepwise logistic regression retained WA% as the only explanatory covariable (P = .002). Two identified clusters of severe asthmatic patients differed for parameters characterizing airway narrowing (airway count: P = .0002; focal bronchial stenosis: P = .009). Airway count was as discriminant as forced expiratory volume in 1 second/forced vital capacity (P = .01) to identify patients in each cluster, with both variables being correlated (r = 0.59, P = .005). Severe asthma-associated morphologic changes were characterized by focal bronchial stenoses and diffuse airway narrowing; the latter was associated with airflow obstruction. WA%, dependent on airway caliber, is the best parameter to identify severe asthmatic patients from pooled subjects.

Traitement chirurgical de l’hypertension pulmonaire post-embolique

Chronic thromboembolic pulmonary hypertension is a rare but underdiagnosed disease. The development of imaging played a crucial role for the screening and the decision of operability over the past few years. Indeed, chronic thromboembolic pulmonary hypertension is the only type of pulmonary hypertension with a potential curative treatment: pulmonary endarterectomy. It is a complexe surgical procedure performed under cardiopulmonary bypass with deep hypothermia and circulatory arrest. The aim of the procedure is to completely remove the scar tissue inside the pulmonary arteries down to the segmental and sub-segmental levels. Compared to lung transplantation, which carries a postoperative mortality of 15-20% and a 5-year survival of 50%, pulmonary endarterectomy is a curative treatment with a postoperative mortality of less than 3%. However, lung transplantation remains an option for young patients with inoperable distal disease or after pulmonary endarterectomy failure. Considering that medical history of deep venous thrombosis or pulmonary embolism is lacking in 25 to 50%, the diagnosis of chronic thromboembolic pulmonary hypertension remains challenging. The lung V/Q scan is useful for the diagnosis showing ventilation and perfusion mismatches. Lesions located at the level of the pulmonary artery, the lobar or segmental arteries may be accessible to surgical removal. The pulmonary angiogram with the lateral view and the pulmonary CT scan help to determine the level of the intravascular lesions. If there is a correlation between the vascular obstruction assessed by imaging and the pulmonary resistance, pulmonary endarterectomy carries a postoperative mortality of less than 3% and has a high rate of success. If the surgery is performed at a later stage of the disease, pulmonary arteriolitis developed mainly in unobstructed territories and participated in the elevated vascular resistance. At this stage, postoperative risk is higher.

Stress Hypoperfusion and Tissue Injury in Hypertrophic Cardiomyopathy

Background— Ischemia and tissue injury are common in patients with hypertrophic cardiomyopathy. Cardiovascular magnetic resonance imaging offers combined evaluations of each phenomenon at sufficiently high resolution to examine transmural spatial distribution. In this prospective cohort study, we examine the spatial distribution of stress perfusion abnormalities and tissue injury in patients with hypertrophic cardiomyopathy. Methods and Results— One hundred consecutive patients with hypertrophic cardiomyopathy underwent cardiovascular magnetic resonance imaging. Cine, stress perfusion, late gadolinium enhancement, and T2-weighted imaging techniques were used. Each was spatially coregistered according to predefined segmental and subsegmental models and was blindly analyzed for abnormalities using validated techniques. Spatial associations among stress perfusion, late gadolinium enhancement, and T2 imaging were made at segmental and subsegmental levels. Of the 100 patients studied, the phenotype was septal in 86 and apical in 14. Late gadolinium enhancement imaging was abnormal in 79 patients (79%). Eighty-six patients met prespecified safety criteria to undergo stress perfusion, and ischemia was identified in 46 patients (57%). T2 imaging was available in 81 patients and was abnormal in 19 (29%). The dominant distribution of all 3 findings was to segment with hypertrophy. Subsegmental analysis revealed geographic dominance of ischemia within the subendocardial zones. However, this zone was most commonly spared from late gadolinium enhancement and T2 abnormalities, typically seen in midwall and subepicardial zones. Conclusions— Inducible hypoperfusion is a common finding in hypertrophic cardiomyopathy and is typically identified within segments exhibiting imaging markers of tissue injury. However, the respective transmural dominance of these phenomena seems distinct. Alternate factors contributing to a regional susceptibility to tissue injury are deserving of further study.

Speaker Recognition using Supra-segmental Level Excitation Information

Speaker specific information present in the excitation signal is mostly viewed from sub-segmental, segmental and supra-segmental levels. In this work, the supra-segmental level information is explored for recognizing speakers. Earlier study has shown that, combined use of pitch and epoch strength vectors provides useful supra-segmental information. However, the speaker recognition accuracy achieved by supra-segmental level feature is relatively poor than other levels source information. May be the modulation information present at the supra-segmental level of the excitation signal is not manifested properly in pith and epoch strength vectors. We propose a method to model the supra-segmental level modulation information from residual mel frequency cepstral coefficient (R-MFCC) trajectories. The evidences from R-MFCC trajectories combined with pitch and epoch strength vectors are proposed to represent supra-segmental information. Experimental results show that compared to pitch and epoch strength vectors, the proposed approach provides relatively improved performance. Further, the proposed supra-segmental level information is relatively more complimentary to other levels information.

Impact of Tube Current-Time and Tube Voltage Reduction in 64-Detector-row Computed Tomography Pulmonary Angiography for Pulmonary Embolism in a Porcine Model

To evaluate the impact of dose reduction in multidetector computed tomography pulmonary angiography (CTPA) for detection of pulmonary embolism (PE). After induction of PE in 6 anesthetized pigs, a 64-detector-row CTPA was performed at 3 different dose protocols: A (120 kV/120 mAseff.), B (120 kV/80 mAseff.), and C (80 kV/80 mAseff.). Images were evaluated by 2 radiologists independently. A high-dose CTPA (120 kV/250 mAseff.) served as a reference standard. Sensitivity, specificity, and positive and negative predictive values were calculated and compared using the Wilcoxon test. Interobserver agreement was determined by calculation of κ values. Radiation exposure and objective image parameters were assessed and compared with a 2-sided t test. In the reference scan, a total of 94 emboli were detected: 17 in the main and lobar pulmonary level (category A), 47 in the segmental level (category B), and 30 in the subsegmental level (category C). All protocols reached high diagnostic accuracy in the detection of PE in category A. No significant difference was observed between protocols A and B in the detection rate of segmental and subsegmental PE (sensitivity: 93.6% and 91.5% vs 85.1% and 87.2%; positive predictive value: 100% and 97.7% vs 97.5% and 95.3%). Interobserver agreement was excellent at the segmental (κ=0.97 and 0.94) and subsegmental levels (κ=0.94 and 0.92). Using protocol C, the detection rate of segmental and subsegmental emboli was significantly impaired and interobserver agreement was significantly inferior (sensitivity: 46.8% and 44.6% at segmental and 56.7% and 50.0% at subsegmental level; κ=0.70 and 0.60, respectively; P<0.05). Vessel attenuation was significantly higher in protocol C, [710.3 Hounsfield units (HU) ±200.6 SD] than in protocols A (414.4 HU±82.5 SD) and B (428.8 HU±78.9 SD) (P<0.001). Signal-to-noise and contrast-to-noise ratios were significantly decreased in protocols B (55.6; 45.8) and C (44.3; 39.4) compared with protocol A (62.1; 52.3) (P<0.05). Radiation dose was significantly reduced between protocols A and B and protocols B and C [volume CT dose index (CTDIvol): 7.1 vs 4.7 vs 1.4 mGy; dose-length product: 199.5 vs 132.1 vs 39.4 mGy·cm and E: 3.39 vs 2.25 vs 0.6 mSv; P<0.05]. This animal study proves the diagnostic use of a low-dose CTPA protocol with 80 mAseff. at 120 kV for PE evaluation without significant loss of diagnostic accuracy compared with a standard protocol with 120 mAseff. Using an "ultra-low"-dose CTPA protocol (80 kV; 80 mAseff.), emboli detection at the segmental and subsegmental level is significantly impaired, whereas evaluation of central emboli is still feasible with high diagnostic accuracy.

Rapid and multifaceted effects of second-language learning on first-language speech production

Despite abundant evidence of malleability in speech production, previous studies of the effects of late second-language learning on first-language speech production have been limited to advanced learners. This study examined these effects in novice learners, adult native English speakers enrolled in elementary Korean classes. In two acoustic studies, learners' production of English was found to be influenced by even brief experience with Korean. The effect was consistently one of assimilation to phonetic properties of Korean; moreover, it occurred at segmental, subsegmental, and global levels, often simultaneously. Taken together, the results suggest that cross-language linkages are established from the onset of second-language learning at multiple levels of phonological structure, allowing for pervasive influence of second-language experience on first-language representations. The findings are discussed with respect to current notions of cross-linguistic similarity, language development, and historical sound change.

Deep vein thrombosis and pulmonary embolism: diagnosis, treatment and prevention

Venous thromboembolism (VTE), encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE), is a major public health issue, with an incidence of 1/1,000 and thousands of VTE-related deaths each year in the UK. The estimated cost of VTE and its complications to the NHS is in excess of £600 million. 1 PE is the most common cause of inpatient mortality, and is the leading cause of death in pregnant women. Common risk factors include hospitalisation, surgery, cancer and immobilisation; and in women, combined oral contraceptive use, hormone replacement therapy and pregnancy. Approximately a quarter of VTE episodes are unprovoked, that is without an identifiable precipitant. 2 Clinical features of DVT include swelling and pain, pitting oedema, increased warmth and superficial venous dilation of the lower limb. PE may present with or without symptoms of a DVT in addition to chest pain, breathlessness, haemoptysis, syncope, hypotension, tachycardia and hypoxia. Without prompt recognition and treatment, PE can lead to death in up to 30%. Clinical diagnosis of VTE can be challenging and, furthermore, clinically silent episodes are not uncommon. Integrated diagnostic strategies have been demonstrated to be safe, efficacious and cost effective. 3 These strategies employ the use of a clinical pretest probability score (Table 1) in combination with D-dimer to inform the need for further diagnostic imaging. Patients at low risk of DVT/PE with a negative Ddimer result (using a high sensitivity assay) require no further investigation. However, those identified as moderate or high probability, or with a raised D-dimer require definitive imaging to confirm or exclude the diagnosis. Non-invasive compression ultrasonography is increasingly used first line for investigation of DVT, with advantages over venography including superior safety and portability. Sensitivity can be adversely affected by operator experience and poor views may be obtained in the presence of severe obesity, gross oedema or a plaster cast. However, its sensitivity for symptomatic proximal DVT remains up to 97%. 4 Computed tomography (CT) pulmonary angiography is currently accepted as the investigation of choice for PE diagnosis 5 ; its increased resolution allows detection of PE to subsegmental levels, in addition to detection of alternate diagnoses, such as, infection or cancer. Treatment for VTE is primarily aimed at prevention of clot extension, embolisation and symptom relief, with additional long-term aims of minimising recurrence and preventing postthrombotic syndrome. 6 Anticoagulation is the mainstay of treatment and should be initiated at confirmation of diagnosis or when first suspected if there is a delay in diagnostic imaging. Thrombolysis or surgical thrombectomy/embolectomy should be reserved for selected patients with haemodynamic instability due to massive PE or critical limb ischaemia secondary to DVT. Low molecular weight heparins (LMWHs) are the preferred agents for initiation of anticoagulation due to improved efficacy, safety and ease of administration with once daily subcutaneous injection. 6 Monitoring of the anticoagulant effect is not required routinely with LMWH and rates of early mortality, recurrence and major bleeding are reduced compared to unfractionated heparin, as is the risk of heparin-induced thrombocytopenia. Warfarin should be initiated once the diagnosis of VTE is confirmed, in the absence of contraindications,

Assessment of liver function in primary biliary cirrhosis using Gd-EOB-DTPA-enhanced liver MRI

ObjectivesGd-EOB-DTPA (gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid) is a gadolinium-based hepatocyte-specific contrast agent for magnetic resonance imaging (MRI). The aim of this study was to determine whether the hepatic uptake and excretion of Gd-EOB-DTPA differ between patients with primary biliary cirrhosis (PBC) and healthy controls, and whether differences could be quantified. MethodsGd-EOB-DTPA-enhanced liver MRI was performed in 20 healthy volunteers and 12 patients with PBC. The uptake of Gd-EOB-DTPA was assessed using traditional semi-quantitative parameters (Cmax, Tmax and T1/2), as well as model-free parameters derived after deconvolutional analysis (hepatic extraction fraction [HEF], input-relative blood flow [irBF] and mean transit time [MTT]). In each individual, all parameters were calculated for each liver segment and the median of the segmental values was used to define a global liver median (GLM). ResultsAlthough the PBC patients had relatively mild disease according to their Model for End-stage Liver Disease (MELD), Child–Pugh and Mayo risk scores, they had significantly lower HEF and shorter MTT values compared with the healthy controls. These differences significantly increased with increasing MELD and Child–Pugh scores. ConclusionsDynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) has a potential role as an imaging-based liver function test. The high spatial resolution of MRI enables hepatic function to be assessed on segmental and sub-segmental levels.

Histological evaluation of bronchial tissue from elderly individuals with bronchial asthma

We studied morphologic and morphometric characteristics of the bronchial walls in lungs obtained at autopsy form elderly patients who had had bronchial asthma. Thirteen patients (age at time of death 57 to 98 years; average, 81 years) were divided into three groups: AS, died of severe asthma attack (n = 4); AC, admitted with asthma symptoms but died of other diseases (n = 6); and NA, died of other diseases and had had no asthma symptoms in the year before death (n = 3). Lungs from ten non-smokers with no history of bronchial asthma or other lung disorders were used as control. Transverse sections of segmental and subsegmental bronchi were prepared, and four quantities were analyzed: 1) the ratio of total bronchial gland area to total area of the bronchial wall (Yamanaka index), 2) the thickness of the basement membrane, 3) the thickness of the smooth muscle bundle, and 4) the ratio of luminal area to total area of the bronchial wall (bronchial dilation ratio). In the AS group, the Yamanaka index and the thickness of the smooth muscle bundles and of the basement membrane were significantly greater than those in the control group at both the segmental and subsegmental levels, with massive eosinophil infiltration into the bronchial walls. Furthermore the bronchial dilation ratio at the subsegmental level correlated closely with the Yamanaka index. Thickness of the smooth muscle bundle seemed to be most representative of the severity of asthma symptoms. In conclusion, morphometric findings of bronchial walls in elderly patients with asthma symptoms seem to be similar to those in their younger counterparts.

Intelligibility of interrupted sentences at subsegmental levels in young normal-hearing and elderly hearing-impaired listeners

Although listeners can partially understand sentences interrupted by silence or noise, and their performance depends on the characteristics of the glimpses, few studies have examined effects of the types of segmental and subsegmental information on sentence intelligibility. Given the finding of twice better intelligibility from vowel-only glimpses than from consonants [Kewley-Port et al. (2007). "Contribution of consonant versus vowel information to sentence intelligibility for young normal-hearing and elderly hearing-impaired listeners," J. Acoust. Soc. Am. 122, 2365-2375], this study examined young normal-hearing and elderly hearing-impaired (EHI) listeners' intelligibility of interrupted sentences that preserved four different types of subsegmental cues (steady-states at centers or transitions at margins; vowel onset or offset transitions). Forty-two interrupted sentences from TIMIT were presented twice at 95 dB SPL, first with 50% and second with 70% of sentence duration. Compared to high sentence intelligibility for uninterrupted sentences, interrupted sentences had significant decreases in performance for all listeners, with a larger decrease for EHI listeners. Scores for both groups were significantly better for 70% duration than for 50% but were not significantly different for the type of subsegmental information. Performance by EHI listeners was associated with their high-frequency hearing thresholds rather than with age. Together with previous results using segmental interruption, preservation of vowels in interrupted sentences provides greater benefit to sentence intelligibility compared to consonants or subsegmental cues.