This paper is meant to be an introduction to and general reference for ultrasound imaging for new and moderately experienced users of the instrument. The paper consists of eight sections. The first explains how ultrasound works, including beam properties, scan types and machine features. The second section discusses image quality, including the interpretation of anatomical features and artefacts seen in the image. The third section discusses the validity of the data collection procedures, including the effects of stabilizing the transducer and head position, and discusses some methods for stabilization. Section four discusses validation of the ultrasound and stabilization systems. The fifth section presents a sample recording set-up, supplemental information, and normalization strategies for sessions and subjects. In section six are methods of extracting contours from ultrasound images, displaying them, and analysing them. The seventh section considers the tracking of pellets on the tongue surface and the differences between tracking tissue points and continuous surfaces. The last section presents methods, challenges and results of 3D, computerized reconstruction of tongue surfaces. An outline of the paper can be found in Appendix I.

A guide to analysing tongue motion from ultrasound images

The position of the tongue relative to the upper and lower jaws is regulated in part by the position of the hyoid bone, which, with the anterior and posterior suprahyoid muscles, controls the angulation and length of the floor of the mouth on which the tongue body 'rides'. The instantaneous shape of the tongue is controlled by the 'extrinsic muscles' acting in con- cert with the 'intrinsic' muscles. Recent anatomical research in non-human mammals has shown that the intrinsic muscles can best be regarded as a 'laminated segmental system' with tightly packed layers of the 'transverse', 'longitudinal', and 'vertical' muscle fibers. Each segment receives separate innervation from branches of the hypoglosssal nerve. These new anatomical find- ings are contributing to the development of functional models of the tongue, many based on increasingly refined finite element modeling techniques. They also begin to explain the observed behavior of the jaw-hyoid-tongue complex, or the hyomandibu- lar 'kinetic chain', in feeding and consecutive speech. Similarly, major efforts, involving many imaging techniques (cinefluo- rography, ultrasound, electro-palatography, NMRI, and others), have examined the spatial and temporal relationships of the tongue surface in sound production. The feeding literature shows localized tongue-surface change as the process progresses. The speech literature shows extensive change in tongue shape between classes of vowels and consonants. Although there is a fundamental dichotomy between the referential framework and the methodological approach to studies of the orofacial com- plex in feeding and speech, it is clear that many of the shapes adopted by the tongue in speaking are seen in feeding. It is sug- gested that the range of shapes used in feeding is the matrix for both behaviors.

/pdf/tongue-movements-in-feeding-and-speech-2gbzovxmd8.pdf

Tongue movements in feeding and speech

In this paper we demonstrate a new technique for deriving discrete adjoint and tangent linear models of a finite element model. The technique is significantly more efficient and automatic than standard algorithmic differentiation techniques. The approach relies on a high-level symbolic representation of the forward problem. In contrast to developing a model directly in Fortran or C++, high-level systems allow the developer to express the variational problems to be solved in near-mathematical notation. As such, these systems have a key advantage: since the mathematical structure of the problem is preserved, they are more amenable to automated analysis and manipulation. The framework introduced here is implemented in a freely available software package named dolfin-adjoint, based on the FEniCS Project. Our approach to automated adjoint derivation relies on run-time annotation of the temporal structure of the model and employs the FEniCS finite element form compiler to automatically generate the low-level co...

Automated Derivation of the Adjoint of High-Level Transient Finite Element Programs

Chiari Type I Malformation in a Pediatric Population

This paper presents three-dimensional tongue surfaces reconstructed from multiple coronal cross-sectional slices of the tongue. Surfaces were reconstructed for sustained vocalizations of the American English sounds [symbol: see text]. Electropalatography (EPG) data were also collected for the sounds to compare tongue surface shapes with tongue-palate contact patterns. The study was interested also in whether 3-D surface shapes of the tongue were different for consonants and vowels. Previous research and speculation had found that there were differences in production, acoustics, and linguistic usage between the two groups. The present study found that four classes of tongue shape were adequate to categorize all the sounds measured. These classes were front raising, complete groove, back raising, and two-point displacement. The first and third classes have been documented before in the midsagittal plane [cf. R. Harshman, P. Ladefoged, and L. Goldstein, J. Acoust. Soc. Am. 62, 693-707 (1976)]. The first three classes contained both vowels and consonants, the last only consonants. Electropalatographic patterns of the sounds indicated three categories of tongue-palate contact: bilateral, cross-sectional, and combination of the two. Vowels used only the first pattern, consonants used all three. The EPG data provided an observable distinction in contact pattern between consonants and vowels. The ultrasound tongue surface data did not. The conclusion was that the tongue actually has a limited repertoire of shapes and positions them against the palate in different ways for consonants versus vowels to create narrow channels, divert airflow, and produce sound.

/pdf/three-dimensional-tongue-surface-shapes-of-english-39297lsra4.pdf

Three-dimensional tongue surface shapes of English consonants and vowels

Object. Syringomyelia causes progressive myelopathy. Most patients with syringomyelia have a Chiari I malformation of the cerebellar tonsils. Determination of the pathophysiological mechanisms underlying the progression of syringomyelia associated with the Chiari I malformation should improve strategies to halt progression of myelopathy. Methods. The authors prospectively studied 20 adult patients with both Chiari I malformation and symptomatic syringomyelia. Testing before surgery included the following: clinical examination; evaluation of anatomy by using T1-weighted magnetic resonance (MR) imaging; evaluation of the syrinx and cerebrospinal fluid (CSF) velocity and flow by using phase-contrast cine MR imaging; and evaluation of lumbar and cervical subarachnoid pressure at rest, during the Valsalva maneuver, during jugular compression, and following removal of CSF (CSF compliance measurement). During surgery, cardiac-gated ultrasonography and pressure measurements were obtained from the intracranial, ce...

Elucidating the pathophysiology of syringomyelia

This study used ultrasound imaging to examine the cross‐sectional shape of the tongue during the production of the ten English vowels /i,i,e,q,ae,a,v,o,0,u/ in two consonant contexts—/p/ and /s/—and at two scan angles—anterior and posterior. Results were compared with models of sagittal tongue shape. A newly built transducer holder and head restraint maintained the ultrasound transducer in a fixed position inferior to the mandible at a chosen location and angle. The transducer was free to move only in a superior/inferior direction, and demonstrated reliable tracking of the jaw. Since the tongue is anisotrophic along its length, anterior and posterior scan angles were examined to identify differences in tongue shape. Similarly, the coarticulatory effects of the sibilant /s/ versus the bilabial /p/ were examined, to assess variability of intrinsic tongue shape for the vowels. Results showed that the subject’s midsagittal tongue grooving was almost universal for the vowels. Posterior grooves were deeper than anterior grooves. In /s/ context, posterior tongue grooves were shallower than in /p/ context. Anteriorly, /s/ context caused deeper grooves for low vowels. Cross‐sectional tongue shape varied with tongue position similarly to sagittal tongue shape.

Cross-sectional tongue shape during the production of vowels

/pdf/elucidating-the-pathophysiology-of-syringomyelia-58s3f89nu8.pdf

e13648 Background: Malignancy associated thrombosis places a significant clinical and financial burden on all major oncology services worldwide. Cancer patients are at an increased risk of thrombosis and large studies have suggested a subsequent increased mortality. (1) Some studies have recorded higher risk associated with certain chemotherapy regimens such as platinum-based agents and gemcitabine. (2) Guidelines for anticoagulation often recommend low molecular weight heparin (LMWH) as first line for malignancy associated thrombosis. (3) In recent years ASCO guidelines have added DOACs as an option for VTE treatment. (4) We herein describe eight cases of recurrent venous thromboembolism despite direct oral anticoagulation. Methods: Data was gathered from electronic patient records for cancer patients attending a single centre in Western Australia between 2016 and 2021. Radiology and medication records were used to confirm VTE diagnoses and subsequent treatment. This data was recorded on an excel file and analysed accordingly. Results: We identified 8 patients with recurrent VTE on DOACs. Median age of patients was 61 years (range 50-72). The most common associated malignancy was pancreatic cancer (n = 3). Other associated cancer types were ovarian (n = 2), lung adenocarcinoma (n = 2) and colorectal cancer(n = 1). Most patients had metastatic disease at time of first VTE(n = 5). The most common site of thrombosis was in the upper limb with 3 cases of initial VTE and 4 cases of recurrent VTE. All of these occurred in patients with peripherally inserted central catheters. (PICC) One patient had a left central retinal vein thrombosis resulting in complete loss of vision in that eye. All but one patient had received either platinum based chemotherapy or gemcitabine. Median time to initial thrombotic event was 4 months from diagnosis. Median time to recurrent thrombotic event was 3.5 months. Rivaroxaban was the most common DOAC used with initial VTE (n = 5). All other patients received apixaban (n = 3). All patients were switched to either LMWH (n = 6) or unfractionated heparin (n = 2) following recurrent VTE. 75% of patients did not have further thrombosis after switch to heparin. One patient had chronic thrombosis on subsequent scans and another patient had recurrent pulmonary embolism despite unfractionated heparin and vena cava filter insertion. Conclusions: Venous thromboembolism is a common complication of malignancy with significant associated morbidity and mortality. A high index of suspicion is needed in patients with clinical signs of recurrent VTE while on a DOAC, especially for those with PICCs. While DOACs are common for patient preference, the differing rates of VTE recurrences should be further investigated and considered in oncology prescribing practice going forward.

Recurrent venous thromboembolism in cancer patients treated with direct oral anticoagulants.

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Elucidating the pathophysiology of syringomyelia

Cross-sectional tongue shape during the production of vowels

Elucidating the pathophysiology of syringomyelia

Recurrent venous thromboembolism in cancer patients treated with direct oral anticoagulants.