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PubMed2002

Local frequency representations for robust multimodal image registration.

Automatic registration of multimodal images involves algorithmically estimating the coordinate transformation required to align the data sets. Most existing methods in the literature are unable to cope with registration of image pairs with large nonoverlapping field of view (FOV). We propose a robust algorithm, based on matching dominant local frequency image representations, which can cope with image pairs with large nonoverlapping FOV. The local frequency representation naturally allows for processing the data at different scales/resolutions, a very desirable property from a computational efficiency view point. Our algorithm involves minimizing-over all rigid/affine transformations--the integral of the squared error (ISE or L2 E) between a Gaussian model of the residual and its true density function. The residual here refers to the difference between the local frequency representations of the transformed (by an unknown transformation) source and target data. We present implementation results for image data sets, which are misaligned magnetic resonance (MR) brain scans obtained using different image acquisition protocols as well as misaligned MR-computed tomography scans. We experimently show that our L2E-based scheme yields better accuracy over the normalized mutual information.

Brain↗
PubMed2003

Interpolation artifacts in multimodality image registration based on maximization of mutual information.

Mutual information (MI) is an increasingly popular match metric for multimodality image registration. However, its value is affected by interpolation, which may limit registration accuracy. The purpose of this study was to characterize the artifacts from eight interpolators and to investigate efficient strategies to overcome these artifacts. The interpolators were: 1) nearest neighbor; 2) linear; 3) cubic Catmull-Rom; 4) Hamming-windowed sinc; 5) partial volume; 6) NN with jittered sampling (JIT); 7) NN with histogram blurring (BLUR); and 8) NN with JIT and BLUR. The impact of interpolation on MI was evaluated in two dimensions over different translational and rotational misregistration. Interpolation caused spurious fluctuations in MI whenever the voxel grids had coinciding periodicities and were nearly aligned. The artifacts did not lessen by using intensity interpolators with wider support (e.g., cubic Catmull-Rom, Hamming-windowed sinc). PV could lead to either arch artifacts or inverted-arch artifacts, depending on the relative voxel sizes. Several strategies reduced artifacts and improved registration robustness: JIT, BLUR, avoiding an extreme number of intensity bins, and resampling the images in a rotated orientation with different relative voxel sizes (e.g., pi/3). These findings also apply to related methods, including normalized MI, joint entropy, and Hill's third moment.

Algorithms↗
PubMed2004

Interactive virtual endoscopy in coronary arteries based on multimodality fusion.

A novel approach for platform-independent virtual endoscopy in human coronary arteries is presented in this paper. It incorporates previously developed and validated methodology for multimodality fusion of two X-ray angiographic images with pullback data from intravascular ultrasound (IVUS). These modalities pose inherently different challenges than those present in many tomographic modalities that provide parallel slices. The fusion process results in a three- or four-dimensional (3-D/4-D) model of a coronary artery, specifically of its lumen/plaque and media/adventitia surfaces. The model is used for comprehensive quantitative hemodynamic, morphologic, and functional analyses. The resulting quantitative indexes are then used to supplement the model. Platform-independent visualization is achieved through the use of the ISO/IEC-standardized Virtual Reality Modeling Language (VRML). The visualization includes an endoscopic fly-through animation that enables the user to interactively select vessel location and fly-through speed, as well as to display image pixel data or quantification results in 3-D. The presented VRML virtual-endoscopy system is used in research studies of coronary atherosclerosis development, quantitative assessment of coronary morphology and function, and vascular interventions.

Algorithms↗
PubMed2005

Automatic analysis of multimodal group actions in meetings.

This paper investigates the recognition of group actions in meetings. A framework is employed in which group actions result from the interactions of the individual participants. The group actions are modeled using different HMM-based approaches, where the observations are provided by a set of audiovisual features monitoring the actions of individuals. Experiments demonstrate the importance of taking interactions into account in modeling the group actions. It is also shown that the visual modality contains useful information, even for predominantly audio-based events, motivating a multimodal approach to meeting analysis.

Algorithms↗
PubMed2005

Ensembling local learners through multimodal perturbation.

Ensemble learning algorithms train multiple component learners and then combine their predictions. In order to generate a strong ensemble, the component learners should be with high accuracy as well as high diversity. A popularly used scheme in generating accurate but diverse component learners is to perturb the training data with resampling methods, such as the bootstrap sampling used in bagging. However, such a scheme is not very effective on local learners such as nearest-neighbor classifiers because a slight change in training data can hardly result in local learners with big differences. In this paper, a new ensemble algorithm named Filtered Attribute Subspace based Bagging with Injected Randomness (FASBIR) is proposed for building ensembles of local learners, which utilizes multimodal perturbation to help generate accurate but diverse component learners. In detail, FASBIR employs the perturbation on the training data with bootstrap sampling, the perturbation on the input attributes with attribute filtering and attribute subspace selection, and the perturbation on the learning parameters with randomly configured distance metrics. A large empirical study shows that FASBIR is effective in building ensembles of nearest-neighbor classifiers, whose performance is better than that of many other ensemble algorithms.

Algorithms↗
PubMedDate not supplied

Infants' perception of the audible, visible, and bimodal attributes of multimodal syllables.

Three experiments investigated 4-, 6-, and 8-month-old infants' perception of the audible, visible, and combined attributes of bimodally specified syllables. Ninety-six infants in each experiment were habituated to a person mouthing and uttering a syllable and then tested for detection of changes of either the audible, visible, or combined attributes of the syllable. When the attributes of the syllable were produced in an adult-directed manner, all three age groups discriminated the audible and bimodal attribute changes but only the 8-month-olds discriminated the visible one. When the difference between the familiar and novel attributes of the syllable was enhanced by testing with a novel syllable produced in an infant-directed manner, all three age groups detected all three types of changes. Finally, to test the possible role of audiovisual synchrony in responsiveness, infants were tested with an asynchronous syllable spoken either by the same person or by a novel person following habituation to a synchronous syllable. Results suggested that at four months infants attended primarily to the featural information, at six months primarily to the asynchrony, and at eight months to both features independently. These results help identify some of the important dimensions of multimodal speech during early development.

Age Factors↗
PubMed2004

Probing plasma membrane microdomains in cowpea protoplasts using lipidated GFP-fusion proteins and multimode FRET microscopy.

Summary Multimode fluorescence resonance energy transfer (FRET) microscopy was applied to study the plasma membrane organization using different lipidated green fluorescent protein (GFP)-fusion proteins co-expressed in cowpea protoplasts. Cyan fluorescent protein (CFP) was fused to the hyper variable region of a small maize GTPase (ROP7) and yellow fluorescent protein (YFP) was fused to the N-myristoylation motif of the calcium-dependent protein kinase 1 (LeCPK1) of tomato. Upon co-expressing in cowpea protoplasts a perfect co-localization at the plasma membrane of the constructs was observed. Acceptor-photobleaching FRET microscopy indicated a FRET efficiency of 58% in protoplasts co-expressing CFP-Zm7hvr and myrLeCPK1-YFP, whereas no FRET was apparent in protoplasts co-expressing CFP-Zm7hvr and YFP. Fluorescence spectral imaging microscopy (FSPIM) revealed, upon excitation at 435 nm, strong YFP emission in the fluorescence spectra of the protoplasts expressing CFP-Zm7hvr and myrLeCPK1-YFP. Also, fluorescence lifetime imaging microscopy (FLIM) analysis indicated FRET because the CFP fluorescence lifetime of CFP-Zm7hvr was reduced in the presence of myrLeCPK1-YFP. A FRET fluorescence recovery after photobleaching (FRAP) analysis on a partially acceptor-bleached protoplast co-expressing CFP-Zm7hvr and myrLeCPK1-YFP revealed slow requenching of the CFP fluorescence in the acceptor-bleached area upon diffusion of unbleached acceptors into this area. The slow exchange of myrLeCPK1-YFP in the complex with CFP-Zm7hvr reflects a relatively high stability of the complex. Together, the FRET data suggest the existence of plasma membrane lipid microdomains in cowpea protoplasts.

Base Sequence↗
PubMed2005

The development, validity and reliability of a multimodality objective structured clinical examination in psychiatry.

OBJECTIVES: To evaluate the development, validity and reliability of a multimodality objective structured clinical examination (OSCE) in undergraduate psychiatry, integrating interactive face-to-face and telephone history taking and communication skills stations, videotape mental state examinations and problem-oriented written stations. METHODS: The development of the OSCE on a restricted budget is described. This study evaluates the validity and reliability of 4 15-18-station OSCEs for 128 students over 1 year. Face and content validity were assessed by a panel of clinicians and from feedback from OSCE participants. Correlations with consultant clinical 'firm grades' were performed. Interrater reliability and internal consistency (interstation reliability) were assessed using generalisability theory. RESULTS: The OSCE was feasible to conduct and had a high level of high perceived face and content validity. Consultant firm grades correlated moderately with scores on interactive stations and poorly with written and video stations. Overall reliability was moderate to good, with G-coefficients in the range 0.55-0.68 for the 4 OSCEs. CONCLUSIONS: Integrating a range of modalities into an OSCE in psychiatry appears to represent a feasible, generally valid and reliable method of examination on a restricted budget. Different types of stations appear to have different advantages and disadvantages, supporting the integration of both interactive and written components into the OSCE format.

Clinical Competence↗
PubMed2006

A multimodal laser Doppler and endosonographic distension device for studying mechanosensation and mucosal blood flow in the oesophagus.

We describe the development of a multimodal device combining bag distension, manometry, high frequency intraluminal ultrasound, laser Doppler flowmetry and symptom registration. Bench tests showed that the different modalities did not influence each other. During bag distension we obtained high quality images of the oesophageal wall for computing biomechanical parameters, and laser Doppler signals showing variation in mucosal perfusion. We conclude that the principle of measurement is sound and that the device can provide a basis for further studies.

Animals↗
PubMed2005

Multimodal early onset stimulation combined with enriched environment is associated with reduced CNS lesion volume and enhanced reversal of neuromotor dysfunction after traumatic brain injury in rats.

This study was designed to determine whether exposure to multimodal early onset stimulation (MEOS) combined with environmental enrichment (EE) after traumatic brain injury (TBI) would improve neurological recovery and to elucidate its morphological correlates. Male Sprague-Dawley rats were subjected to lateral fluid percussion (LFP) brain injury or to sham operation. After LFP, one-third of the animals (injured and sham) were placed under conditions of standard housing (SH), one-third were kept in EE only, and one-third received EE + MEOS. Assessment of neuromotor function 24 h post-injury using a standardized composite neuroscore test revealed an identical pattern of neurological impairment in all animals subjected to LFP. Neuromotor dysfunction in SH animals remained on a similar level throughout the experiment, while improvements were noted in both other groups 7 days post-injury (dpi). On 15 dpi, reversal of neuromotor dysfunction was significantly better in EE + MEOS animals vs. SH- and EE-only groups. In parallel, the comparison of lesion volume in EE + MEOS- vs. EE-only vs. SH rats revealed that animals exposed to EE + MEOS had consistently the lowest values (mm3, mean +/- SD; n = 6 rats in each group) as measured in serial brain sections immunostained for neuron-specific enolase (5.2 +/- 3.4 < or = 5.5 +/- 4.1 < 9.5 +/- 1.9), caspase 3-active/C3A (5.9 +/- 4.0 < or = 6.4 +/- 3.9 < 10.3 +/- 1.8) and glial fibrillary acidic protein (6.0 +/- 3.4 < or = 6.5 +/- 4.3 < 10.7 +/- 1.2). This first report on the effect of EE + MEOS treatment strongly indicates that the combined exposure reduces CNS scar formation and reverses neuromotor deficits after TBI in rats.

Animals↗
PubMed2005

Multimodal management of urolithiasis in renal transplantation.

OBJECTIVE: To report the largest single series of renal transplant patients (adults and children) with urolithiasis, assess the risk factors associated with urolithiasis in renal transplant recipients, and report the outcome of the multimodal management by endourological and open procedures. PATIENTS AND METHODS: The records of all patients undergoing renal transplantation between 1977 and 2003 were reviewed. In all, 2085 patients had a renal transplant at our centre and 21 (17 adults and four children) developed urinary tract calculi. Their mode of presentation, investigations, treatments, complications and outcomes were recorded. Investigations included one or more of the following; ultrasonography (US), plain abdominal X-ray, intravenous urography, nephrostogram and computed tomography. Management of these calculi involved extracorporeal shock wave lithotripsy (ESWL), flexible ureteroscopy and in situ lithotripsy, percutaneous nephrolithotomy (PCNL), open pyelolithotomy and open cystolitholapaxy. RESULTS: Thirteen patients had renal calculi, seven had ureteric calculi and one had bladder calculi. The incidence of urolithiasis was 21/2085 (1.01%) in the series. Urolithiasis was incidentally discovered on routine US in six patients, six presented with oliguria or anuria, including one with acute renal failure, four with a painful graft, three with haematuria, one with sepsis secondary to obstruction and infection and in one, urolithiasis was found after failure to remove a stent. Ten patients (63%) had an identifiable metabolic cause for urolithiasis, two by obstruction, two stent-related, one secondary to infection and in six no cause was identifiable. Thirteen required more than one treatment method; 13 (69%) were treated by ESWL, eight of whom required multiple sessions; eight required ureteric stent insertion before a second procedure and four required a nephrostomy tube to relieve obstruction. Two patients had flexible ureteroscopy and stone extraction, three had a PCNL and one had open cystolithotomy. PCNL failed in one patient who subsequently had successful open pyelolithotomy. All patients were rendered stone-free when different treatments were combined. CONCLUSIONS: The incidence of urolithiasis in renal transplant patients is low. There is a high incidence of metabolic causes and therefore renal transplant patients with urolithiasis should undergo comprehensive metabolic screening. Management of these patients requires a multidisciplinary approach by renal physicians, transplant surgeons and urologists.

Adolescent↗
PubMedDate not supplied

Experiential influences on multimodal perception of emotion.

The impact of 2 types of learning experiences on children's perception of multimodal emotion cues was examined. Children (aged 7-12 years) were presented with conflicting facial and vocal emotions. The effects of familiarity were tested by varying whether emotions were presented by familiar or unfamiliar adults. The salience of particular emotional expressions was tested by contrasting the performance of physically abused and nonabused children. Children exhibited a preference for auditory expressions produced by their mothers but not by strangers. Additionally, abused children were biased to rely on auditory cues when their own abusive mother was expressing anger. These results are discussed in terms of the impact of both typical and atypical early experiences on the development of emotion perception.

Affect↗
PubMed1986

Anorexia nervosa in a pre-adolescent girl: a multimodal behaviour therapy approach.

A multimodal method of behavioural therapy was used in the case of a pre-adolescent girl with anorexia nervosa. This followed two previous admissions to a paediatric department. Three main conclusions emerged from pre and post therapy objective evaluations. Weight gain in anorexia is a necessary but insufficient basis for sustained improvement. Important interactive psychosocial factors have to be adequately addressed to improve the chances of effective therapy. A focused approach relevant to each of a number of important different, but overlapping, areas is likely to facilitate better potential for treatment effectiveness than a general ('non-specific') management approach.

Anorexia Nervosa↗
PubMed1993

The treatment of advanced Merkel cell carcinoma. A multimodality chemotherapy and radiation therapy treatment approach.

BACKGROUND: The optimal management of Merkel cell carcinoma has not been clearly defined. OBJECTIVE: To describe the treatment of eight patients who presented with Merkel cell carcinoma. METHODS: Eight patients with advanced locoregional Merkel cell carcinoma were seen in our institute over a 7-year period. Four patients were successfully treated by induction chemotherapy after excisional biopsy, followed by radiotherapy. Three patients died from widespread metastases and one from neutropenic sepsis induced by chemotherapy. RESULTS: These cases demonstrate the potential lethality and aggressive nature of this rare skin tumor despite its chemosensitive and radioresponsive character. In all four patients who are alive and disease-free, chemotherapy was given first and radiotherapy was given as consolidation. CONCLUSION: We suggest that a multimodality treatment approach--chemotherapy followed by radiotherapy--is indicated in patients with advanced Merkel cell carcinoma.

Adult↗
PubMedDate not supplied

Uterine papillary serous carcinoma: evaluation of multimodality treatment with abdominopelvic radiotherapy and chemotherapy.

The aim of this study was to compare overall survival (OS), progression-free survival (PFS), and relapse patterns between different modalities of treatment for uterine papillary serous carcinoma (UPSC). A retrospective review of 124 patients with pathologically confirmed UPSC was performed, of whom, 97 patients were eligible for study. Postoperative treatment groups included adjuvant radiotherapy consisting of whole abdomen and a pelvic boost (abdominopelvic radiotherapy [APRT]) (55 patients), paclitaxel and carboplatin chemotherapy (CT) for six cycles followed by APRT (18 patients), CT only (5 patients), and 19 patients were observed without postoperative adjuvant therapy. Three-year OS was 81% and 63% for the CT followed by APRT and APRT alone, respectively (P= 0.11). After controlling for stage, the group treated with APRT alone had significantly decreased OS and PFS compared to the CT/APRT group (HR 3.6; 1.3-9.8; P= 0.01) and (HR 2.9; 95% CI 1.1-7.3; P= 0.03), respectively. Within the limitations of a retrospective study, the results of this study indicate that multimodality postoperative treatment with paclitaxel and a platinum-based CT followed by APRT may increase the survival of patients with UPSC. However, further prospective studies using these combined modalities are needed to confirm these findings.

Adenocarcinoma, Papillary↗
PubMed2006

Long-term effects of a multimodal approach including immunoadsorption for the treatment of myasthenic crisis.

A multimodal treatment protocol with immunoadsorption (IA) as the central element was used in the treatment of myasthenic crisis (MC). Fifteen patients with MC were treated in repeated, uninterrupted 7-day cycles until mobilization with: (i) large-volume IA using an antihuman-IgG adsorber, days 1-5; (ii) intravenous immunoglobulin substitution (0.3-0.5 g/kg body weight [BW]/day), days 5-7; and (iii) immunosuppression with cyclophosphamide (1-2 mg/kg BW/day) and prednisolone (0.5-1 mg/kg BW/day), until remission. Patients required a median of 8 days of mechanical ventilation, 12 days in the intensive care unit, and 35 days of hospitalization. Functional improvement compared to their precrisis condition was attained by 14 of 15 patients. MG severity score improved by a mean of 10 points, quality of life score by 9.8 points, and Karnofsky index by 29 points in 14 of 15 patients. Improvements remained stable and no further crises occurred during long-term follow-up, which averaged 4.4 years. No fatalities due to MC occurred. The results demonstrate that our protocol is a potent therapeutic approach in the treatment of MC.

Adult↗
PubMed1986

Multimodal evoked responses and cerebrospinal fluid oligoclonal immunoglobulins in patients with multiple sclerosis.

One hundred patients with possible, probable and definite multiple sclerosis (MS) were examined with somatosensory (SER), visual (VER) and brain stem auditory (BAER) evoked responses. Paired samples of cerebrospinal fluid (CSF) and serum were examined with agarose gel electrophoresis to detect intrathecally synthesized oligoclonal immunoglobin bands. Comparison of the number of abnormal CSF and evoked response tests showed that the CSF examination was slightly more sensitive in all diagnostic groups when compared to the results of multimodal evoked responses but that the two sets of test were in part supplementary. Oligoclonal immunoglobulin bands in the CSF were present in all patients with a duration of the disease of less than six months. VER seemed to be the most sensitive of the evoked tests in this particular group of patients.

Brain Stem↗