A semiautomatic method for in vivo three-dimensional quantitative analysis of fascial layers mobility based on 3D ultrasound scans.

PURPOSE: Recently, there has been an increasing interest in the role of deep fascia mobility in musculoskeletal dynamics and chronic pain mechanisms; however, no strategies have been presented so far to study in vivo fascial motion in 3D. This paper presents a semiautomatic method, based on ultrasound (US) imaging, enabling a 3D evaluation of fascia mobility. METHODS: The proposed approach relies on the acquisition of 3D US datasets at rest and during a voluntary muscular contraction and consists of two phases: 3D US dataset analysis and generation of a displacement vector field using a block matching technique (Phase 1) and validation and filtering of the resulting displacement vector field for outliers removal (Phase 2). The accuracy and effectiveness of the proposed method were preliminarily tested on different 3D US datasets, undergoing either simulated (procedural) or real (muscular contraction) deformations. RESULTS: As for the simulated deformation, estimated displacement vectors resulting from Phase 1 presented a mean magnitude percentage error of 8.05 % and a mean angular error of 4.78° which, after Phase 2, were reduced by 69.44 and by 83.05 %, respectively. Tests on real deformations further validated the effectiveness of Phase 2 in the removal of outliers from the displacement vector field. CONCLUSIONS: Obtained results preliminarily demonstrate the viability of the proposed algorithm for the analysis of fascia mobility. Such analysis can enable clinicians to better understand the fascia role in musculoskeletal dynamics and disorder. Further experiments are needed to optimize the method in consideration of the anatomical region to be studied.

Hybrid simulation using mixed reality for interventional ultrasound imaging training.

PURPOSE: Ultrasound (US) imaging offers advantages over other imaging modalities and has become the most widespread modality for many diagnostic and interventional procedures. However, traditional 2D US requires a long training period, especially to learn how to manipulate the probe. A hybrid interactive system based on mixed reality was designed, implemented and tested for hand-eye coordination training in diagnostic and interventional US. METHODS: A hybrid simulator was developed integrating a physical US phantom and a software application with a 3D virtual scene. In this scene, a 3D model of the probe with its relative scan plane is coherently displayed with a 3D representation of the phantom internal structures. An evaluation study of the diagnostic module was performed by recruiting thirty-six novices and four experts. The performances of the hybrid (HG) versus physical (PG) simulator were compared. After the training session, each novice was required to visualize a particular target structure. The four experts completed a 5-point Likert scale questionnaire. RESULTS: Seventy-eight percentage of the HG novices successfully visualized the target structure, whereas only 45% of the PG reached this goal. The mean scores from the questionnaires were 5.00 for usefulness, 4.25 for ease of use, 4.75 for 3D perception, and 3.25 for phantom realism. CONCLUSIONS: The hybrid US training simulator provides ease of use and is effective as a hand-eye coordination teaching tool. Mixed reality can improve US probe manipulation training.

Simultaneous tracking of catheters and guidewires: comparison to standard fluoroscopic guidance for arterial cannulation.

OBJECTIVES: The purpose of this in vitro study was to clinically assess the feasibility of a three-dimensional (3D) electromagnetic (EM) navigator, including sensorized catheters and guidewires, to determine any reduction in radiation dose and contrast medium injection. METHODS: The study was performed using a navigator prototype developed at the EndoCAS center. The system includes catheters and guidewires simultaneously tracked with an EM localizer (Aurora, Northern Digital, Waterloo, Canada). Tests were performed on a commercial abdominal aortic aneurysm model. Fifteen operators were asked to cannulate renal arteries using the conventional fluoroscopic guidance and the EM navigator without fluoroscopic support. Each trial was video-recorded and analyzed for timing and success of completing the cannulation task by two blinded and independent observers. Performances were also qualitatively evaluated using the Imperial College Endovascular Cannulation Scoring Tool (IC3ST). Moreover, a questionnaire was administered to participants to evaluate the navigator potentialities. RESULTS: Quantitative analysis results show no significant difference between the fluoroscopic and EM guidance regarding the total procedure time (median 2.36 minutes [interquartile range {IQR} = 1.26-4.7) vs. 2.95 min [IQR = 1.35-5.38], respectively; p = .93); number of total hits with catheter/guidewire tip to vessels wall (median 5.50 [IQR = 2.00-10.00] vs. 3.50 [IQR = 2.50-7.00], respectively; p = .65); and number of attempts at cannulation (median 4.0 [IQR = 2.00-5.00] vs. 4.0 [IQR = 2.00-5.00], respectively; p = .72]. Moreover, there was no significant difference between the IC3ST score obtained using the EM navigator and the traditional method (average 22.37 [STD = 7.95] vs. 21.58 [STD = 6.86]; p = .92). Finally, questionnaire results indicate a general agreement concerning the navigator usefulness, which clearly shows the positions of instruments inside the 3D model of the patient's anatomy. Participants also agreed that the navigator can reduce the amount of contrast media delivered to the patient, as well as fluoroscopy time. CONCLUSIONS: This work provides proof of concept that simultaneous EM navigation of guidewires and catheters is feasible without the use of live fluoroscopic images.

3D ultrasound centerline tracking of abdominal vessels for endovascular navigation.

PURPOSE: Vessel lumen centerline extraction is important for intraoperative tracking of abdominal vessels and guidance of endovascular instruments. Three-dimensional ultrasound has gained increasing acceptance as a safe and convenient surgical image guidance modality. We aimed to optimize vascular centerline detection and tracking in 3D ultrasound. METHOD: To overcome the intrinsic limitation of low ultrasound image quality, an active contour method (snake) was used to track changes in vessel geometry. We tested two variants of a classic snake using the image gradient and gradient vector field (GVF) as external forces. We validated these methods in liver ultrasound images of 10 healthy volunteers, acquired at three breath-holding instances during the exhalation phase. We calculated the distances between the vessel centerlines as detected by algorithms and a gold standard consisting of manual annotations performed by an expert. RESULTS: Both methods (GVF and image gradient) can accurately estimate the actual centerlines with average Euclidean distances of 0.77 and 1.24 mm for GVF and gradient, respectively. Both methods can automatically follow vessel morphology and position changes. CONCLUSIONS: The proposed approach is feasible for liver vessel centerline extraction from 3D ultrasound images. The algorithm can follow the movement of the vessels during respiration; further improvements of hardware components are needed for a real-time implementation.

Augmented reality system for freehand guide of magnetic endovascular devices.

Magnetic guide of endovascular devices or magnetized therapeutic microparticles to the specific target in the arterial tree is increasingly studied, since it could improve treatment efficacy and reduce side effects. Most proposed systems use external permanent magnets attached to robotic manipulators or magnetic resonance imaging (MRI) systems to guide internal carriers to the region of treatment. We aim to simplify this type of procedures, avoiding or reducing the need of robotic arms and MRI systems in the surgical scenario. On account of this we investigated the use of a wearable stereoscopic video see-through augmented reality system to show the hidden vessel to the surgeon; in this way, the surgeon is able to freely move the external magnet, following the showed path, to lead the endovascular magnetic device towards the desired position. In this preliminary study, we investigated the feasibility of such an approach trying to guide a magnetic capsule inside a vascular mannequin. The high rate of success and the positive evaluation provided by the operators represent a good starting point for further developments of the system.

Automatic carotid centerline extraction from three-dimensional ultrasound Doppler images.

Vessel lumen centerline extraction is an important issue for the intra-operative guidance of endovascular instruments; furthermore, vessel centerline is often used as a reference position in many hemodynamic studies, especially in carotid arteries. In this work we propose an innovative method for the extraction of carotid vessels centerline from three-dimensional Color Doppler ultrasound images. The method was tested on carotid Color Doppler images of eighteen healthy subjects and validated by calculating the Euclidean distances between the centerlines detected by the algorithm and those manually annotated by two experts in the corresponding original US volumes. The results show that the proposed approach can accurately estimate the actual centerline with an average error of 1.08 ± 0.54 mm. Furthermore, the method is completely automatic and therefore suitable for the aforementioned purposes.

Replantation of tooth involved in dentigerous cyst: a case report.

AIM: Dentigerous cyst (DC) is a disembriogenetic lesion. The cyst wall encloses the crown of an impacted tooth. Several therapeutic approaches have been mentioned in the literature for management of this lesion. Case Report This article describes the management of an adolescent with a mandibular DC surgically treated with extraction of the tooth, enucleation of the cyst and replantation of the permanent tooth involved. Final outcome shows complete healing of the bone socket with eruption of a vital tooth. No orthodontic traction was required. No recurrence was detected at the radiographic follow-up at 12 months, thus confirming the success of this therapeutic approach. After a 7-year follow-up period the tooth responded positively to the vitality test. CLINICAL IMPLICATIONS: In selected cases surgical enucleation of the lesion without loss of involved tooth, might be considered as a viable treatment to obtain healing of the lesion, spontaneous eruption of the tooth and physiological restoration of bone.

Surgical treatment of bifid mental nerve damaged by root canal therapy. A case report.

This article describes the successful surgical treatment of a case of damage to the inferior alveolar nerve, due to inadvertent extrusion of endodontic material into the mandibular canal. The accident was favoured by an anatomical variant of the nerve canal ending with a double mental foramen, already described in the literature. The complex surgical operation of uncertain outcome was dictated by neuralgia refractory to medical treatment, rather than hypoesthesia associated with compression of the nerve trunk. Problems related to loss of sensitivity and possible causes of nerve damage (traumatic, pathological and iatrogenic) are discussed.

Abnormal oral mucosal light reflectance: a new clinical marker of high risk for colorectal cancer.

BACKGROUND: A familial predisposition to colorectal cancer (CRC) has been clearly established, consisting of familial clustering in 15-20% and clear hereditary aetiology in 5-10% of overall CRC cases. Early identification of families and individuals at high risk is essential as intensive surveillance has been demonstrated to reduce cancer incidence and overall mortality. In the present study, the value of oral mucosal light reflectance in identifying hereditary non-polyposis colorectal cancer (HNPCC) carriers was investigated. METHODS: Twenty members of six different genetically unrelated HNPCC kindred and 30 genetically unrelated age and sex matched healthy controls were examined. Lower gingival and vestibular oral mucosal reflectance was measured using an imaging spectrophotometer. RESULTS: HNPCC carriers showed significantly lower values in the 590-700 nm wavelength range (p

Early postnatal changes in the perfusion index in term newborns with subclinical chorioamnionitis.

BACKGROUND: Chorioamnionitis (HCA) in term newborns is often subclinical and associated with neonatal morbidity and mortality. OBJECTIVE: To assess the value of the pulse oximetry perfusion index (PI) in the early prediction of subclinical HCA in term newborns. METHODS: PI cut-off values were first identified in 51 term newborns with HCA and 115 matched controls, retrospectively categorised on the basis of placental histology (study phase 1). The PI thresholds obtained were subsequently tested on an unselected case series of 329 prospectively recruited, term newborns (study phase 2). PI was evaluated during the first five minutes after delivery. Initial illness severity and short term clinical outcomes were determined. RESULTS: In study phase 1, newborns with HCA had lower PI one and five minutes (p<0.0001) after delivery, lower one minute Apgar score (p = 0.017), lower cord blood base excess (p = 0.0001), together with higher rates of admission to neonatal intensive care unit (p = 0.0001) and endotracheal intubation (p = 0.017), and higher SNAP-PE (p<0.0001) and NTISS (p<0.0001) scores than those without HCA. In the prospective validation phase of the study, the PI cut-off values generated (one minute < or =1.74, five minutes < or =2.18) showed 100% sensitivity, 99.4% specificity, 93.7% positive predictive value, and 100% negative predictive value in identifying subclinical HCA. Early identification of HCA was associated with a decreased rate of admission to intensive care (p = 0.012), as well as lower initial illness severity (p< or =0.0001) and therapeutic intensity (p = 0.0006) than the newborns with HCA in phase 1. CONCLUSION: These findings suggest that early PI monitoring is helpful in identifying HCA in term newborns.

Fordyce granules and hereditary non-polyposis colorectal cancer syndrome.

BACKGROUND: Germline mutations in mismatch repair (MMR) genes are found in only about half of clinically diagnosed families with hereditary non-polyposis colorectal cancer syndrome (HNPCC) (or Lynch syndrome). Early identification of gene carriers is essential to reduce cancer incidence and overall mortality. AIMS: Recent evidence indicates an increase in size and number of sebaceous glands following activation of the hedgehog pathway, a crucial signalling pathway for animal development that is aberrantly activated in several types of cancer. Here we sought to assess a possible association between Fordyce granules (FGs-that is, ectopic sebaceous glands on the oral mucosa) and HNPCC. METHODS: A total of 15 members of five different genetically unrelated HNPCC kindreds (MLH1 gene mutation n = 8; undetectable MLH1 protein at immunochemistry n = 4; clinical diagnosis n = 3) and 630 genetically unrelated age and sex matched healthy controls were examined. Following examination of the oral mucosa surface, subjects were categorised as either FGs positive or FGs negative. RESULTS: Evidence of FGs was significantly associated with HNPCC (13/15 (86.7%) affected patients v 6/630 (0.95%) controls; p<0.0001), with a relative risk of 91.0 (95% confidence interval 40.05-206.76). The observed difference remained significant when carriers of germline mutations in MMR genes were considered (8/15 v 6/630; p<0.0001). The most common site for the FGs in HNPCC patients was the lower gingival and vestibular oral mucosa. CONCLUSIONS: Our findings suggest that a previously unrecognised activation of the sebaceous glands system occurs in HNPCC. The observation could be of value for attending physicians in identifying affected families and/or increase the accuracy of the currently available molecular genetics screenings.

Persistent fetal heart rate hypovariability: a presenting clinical sign of histologic chorioamnionitis at term gestation.

Chorioamnionitis (CA) is asymptomatic in a large fraction of the cases. Here, we report a case of a 39 weeks' gestation infant, with persistent fetal heart rate hypovariability as the only prenatal clinical sign in histologic CA.

Abnormal vascular network complexity: a new phenotypic marker in hereditary non-polyposis colorectal cancer syndrome.

BACKGROUND: Hereditary non-polyposis colorectal cancer (HNPCC) (Lynch cancer family syndrome I (LCFS1) and II (LCFS2)) is one of the most common hereditary cancer disorders. HNPCC results from dominantly inherited germline mutations in mismatch repair (MMR) genes, leading to genomic instability and cancer. No predictive physical signs of HNPCC are available to date. AIMS: Increased complexity in tumour associated vascular growth has been reported. Here, we tested the hypothesis that an increased vascular network complexity is a phenotypic marker for LCFS2. METHODS: Fourteen subjects from an LCFS2 kindred (gene carriers, n=5; non-carriers, n=9) and 30 controls were examined. Fractal dimension (D) at two scales (D (1-46), and D (1-15), tortuosity (minimum path dimension, Dmin), and relative Lempel-Ziev complexity (L-Z) of the vascular networks from the lower gingival and vestibular oral mucosa were measured. RESULTS: LCFS2 networks exhibited a significantly increased overall complexity at both larger (D (1-46): 1.82 (0.04) v 1.68 (0.08); p<0.0001) and smaller (D (1-15): 1.51 (0.11) v 1.20 (0.09); p<0.0001) scales, increased destructured randomness (L-Z: 0.77 (0.09) v 0.56 (0.03); p<0.0001), and decreased vessel tortuosity (DMIN: 1.02 (0.03) v 1.07 (0.04); p=0.0005) compared with control patterns. The vascular networks of LCFS2 gene carriers showed higher complexity at the smaller scale (D (1-15): 1.59 (0.12) v 1.47 (0.07); p=0.034), and higher destructured randomness (L-Z: 0.85 (0.11) v 0.73 (0.05); p=0.013) than those of non-carriers. CONCLUSIONS: Increased oral vascular network complexity is a previously unrecognised phenotypic marker for LCFS2, and is related to gene mutation carrier status.

Absence of the inferior labial and lingual frenula in Ehlers-Danlos syndrome.

The diagnosis of Ehlers-Danlos syndrome is based on distinctive phenotypical characteristics such as hyperelastic skin and hypermobile joints. To date, no congenital physical markers exist for identifying patients with Ehlers-Danlos syndrome. Absence of the inferior labial (100% sensitivity; 99.4% specificity) and lingual frenulum (71.4% sensitivity; 100% specificity) was found to be associated with classical and hypermobility types of Ehlers-Danlos syndrome.

Infantile hypertrophic pyloric stenosis and asymptomatic joint hypermobility.

A significant association with asymptomatic joint hypermobility was observed in 37 children with a history of infantile hypertrophic pyloric stenosis (P =.0016) and their parents (mothers, P <.0001; fathers, P <.05). The subjects with articular hypermobility showed an increased frequency of absent mandibular frenulum, thereby suggesting the presence of a previously unrecognized, systemic abnormality of the extracellular matrix.

Electrical stimulation of anterior visual pathways in retinitis pigmentosa.

PURPOSE: To explore electrically induced phosphenes in blind patients with retinitis pigmentosa (RP) in comparison with healthy subjects and to develop a screening test for candidates for an optic nerve visual prosthesis implantation. METHODS: Phosphenes are obtained by charge balanced biphasic pulse stimulations through a surface cathode over the closed eyelids and an anode near the opposite ear. The resulting strength-duration relationship for somatosensory, phosphene, and pain threshold has been recorded in five RP patients as well as in 10 healthy volunteers. RESULTS: In sighted subjects, the average rheobase and chronaxy for phosphene perception are 0.28 mA and 3.07 msec, respectively. For pulse durations longer than 2 msec, phosphenes are usually obtained at current strengths below the level giving rise to any other electrically generated sensation. In RP patients, however, phosphenes are not so easily obtained. One in five had no visual response at all. Another patient reported a flash perception for the longest pulse durations only. Spontaneous phosphenes interfered heavily with the stimulation in a third person. Finally, despite the higher threshold, two patients displayed normally shaped strength-duration curves. CONCLUSIONS: The surface stimulation has proven harmless, adequate, and very helpful to ascertain that the optic nerve can be electrically activated in completely blind individuals. Long-duration stimulation pulses yield very low phosphene thresholds in healthy subjects. Anterior visual pathways activation requires higher currents in RP patients.

Modelling analysis of human optic nerve fibre excitation based on experimental data.

The aim of the study is to determine which of the existing myelinated mammalian nerve fibre models better fits experimental data resulting from electrical stimulation of the human optic nerve and from propagation velocity measured on primates. The macroscopic electric potential is computed in a 3D, inhomogeneous and anisotropic nerve model. The Chiu-Sweeney (CS) and the Schwarz-Wesselink (SW) membrane descriptions are then considered. Variations in parameters that are not well established (encapsulation-tissue thickness, nerve-fascicle conductivity, geometric and electrochemical fibre cable parameters) are taken into account. Results demonstrate that the SW model predictions are in better agreement with the experimental data than those of the CS model, although thresholds are still too high. When channel densities are varied, the SW model turns out to be more robust than the CS model. For a suitable leakage channel density value (about 8% of the original one), the SW model predicts a conduction velocity of 11.4 ms-1 and an excitation threshold of 0.055 mA (for 0.1 ms pulse duration), which is in very good agreement with experimental values (11 ms-1 and 0.055 mA). Potassium current in the SW model is necessary for stability. Introduction of a potassium-like current can restore stability in the CS system.

Anti-inflammatory and analgesic activities of the latex containing triterpenes from Himatanthus sucuuba.

Some triterpenes and iridoids were previously isolated from the stem bark of Himatanthus sucuuba. The latex from Himatanthus sucuuba is used in popular amazonian medicine as an anti-inflammatory remedy. Fractions of the latex were pharmacologically evaluated with a view to verify this popular use in the carrageenan-induced rat paw edema and in the acetic acid-induced mouse constriction tests. The hexane fraction inhibited the edema formation by 35.9% at a dose of 200 mg/kg (p.o.) but no activity was observed at 100 mg/kg (p.o.). The triterpenes present in the hexane fraction were identified as lupeol acetate, alpha-amyrin and lupeol cinnamates. The fraction containing only cinnamates inhibited the edema and the abdominal constrictions by 50-40% and 57.9%, respectively, at 100 mg/kg (p.o.). Among all the fractions studied, the fraction containing only cinnamates showed the greatest anti-inflammatory activity which suggests that these compounds were responsible for the previously described activity of the crude extract.