Search results for " Computer-Assisted"
showing 10 items of 1033 documents
3D microvascular architecture of pre-cancerous lesions and invasive carcinomas of the colon.
2001
Despite the significance of tumour neoangiogenesis and the extensive knowledge on the molecular basis of blood vessel formation currently no quantitative data exist on the 3D microvascular architecture in human primary tumours and their precursor lesions. This prompted us to examine the 3D vascular network of normal colon mucosa, adenomas and invasive carcinomas by means of quantitative microvascular corrosion casting. Fresh hemicolectomy specimens from 20 patients undergoing cancer or polyposis coli surgery were used for corrosion casting, factor VIII and VEGF immunostaining. In addition, immunostaining was done on colorectal tissue from 33 patients with metastatic and non-metastatic carci…
High-definition imaging in endoscopic transsphenoidal pituitary surgery.
2011
Background The transsphenoidal approach to sellar lesions has evolved enormously since its first description in the early 20th century. Endoscopic surgical strategies have become an integral part of the surgical armamentarium. More recently, high-definition (HD) digital cameras with better image resolution were introduced, although their value for the surgical procedure remains equivocal. The purpose of this study was to compare the image quality of a standard-definition (SD) camera with a new HD camera. Methods A transsphenoidal pituitary adenomectomy was recorded simultaneously in HD and SD resolution. Eight experienced neurosurgeons were asked to identify predefined as well as not predef…
P and R Wave Detection in Complete Congenital Atrioventricular Block
2009
Complete atrioventricular block (type III AVB) is characterized by an absence of P wave transmission to ventricles. This implies that QRS complexes are generated in an autonomous way and are not coordinated with P waves. This work introduces a new algorithm for the detection of P waves for this type of pathology using non-invasive electrocardiographic surface leads. The proposed algorithm is divided into three stages. In the first stage, the R waves located by a QRS detector are used to generate the RR series and time references for the other stages of the algorithm. In the second stage, the ventricular activity (QT segment) is removed by using an adaptive filter that obtains an averaged pa…
Dosage individualization of erythropoietin using a profile-dependent support vector regression
2003
The external administration of recombinant human erythropoietin is the chosen treatment for those patients with secondary anemia due to chronic renal failure in periodic hemodialysis. The objective of this paper is to carry out an individualized prediction of the EPO dosage to be administered to those patients. The high cost of this medication, its side-effects and the phenomenon of potential resistance which some individuals suffer all justify the need for a model which is capable of optimizing dosage individualization. A group of 110 patients and several patient factors were used to develop the models. The support vector regressor (SVR) is benchmarked with the classical multilayer percept…
The utility of 3D medical imaging techniques for obtaining a reliable differential diagnosis of metastatic cancer in an Iron Age skull.
2018
Abstract In this report we present a case of neoplastic disease affecting an Iron Age skull that provides some of the earliest evidence of metastatic cancer (MC) in Western Europe. The cranium comes from the indigenous site of Baucina (Palermo, Sicily) and was recovered in a multiple burial context dated to the 6th–5th centuries BCE. The skull was attributed to an adult female and was characterized by numerous perforating lytic lesions. CT and 3D imaging analyses were crucial for obtaining a diagnosis of MC. Based on the morphology of the lytic lesions and the biological profile of our specimen, we can tentatively suggest breast carcinoma as the primary origin of the clinical manifestations…
Carotid intima-media thickness measurement through semi-automated detection software and analysis of vascular walls
2013
AIM: The aim of the present study was to compare the semi-automatic measurement of carotid intima thickness (RFQIMT - Esaote, Italy), with the conventional method. METHODS: We enrolle 81 patients, mean age 46 years ±15, with no history of cardio-cerebrovascular events and we assessed the traditional cardiovascular risk factors. We examined the IMT of the common carotid artery with manual and RFQIMT method (based on the "Radio Frequency" signal), according to the ASE protocol. RESULTS: Semi-automatic measurement was on average lower than manual measurement (617 μm ±191 vs. 676 μm ± 222) with a statistically significant difference (P<0.01). In agreement with manual measurements, the values of…
Adaptive frequency decomposition of EEG with subsequent expert system analysis.
2001
We present a hybrid system for automatic analysis of clinical routine EEG, comprising a spectral analysis and an expert system. EEG raw data are transformed into the time-frequency domain by the so-called adaptive frequency decomposition. The resulting frequency components are converted into pseudo-linguistic facts via fuzzification. Finally, an expert system applies symbolic rules formulated by the neurologist to evaluate the extracted EEG features. The system detects artefacts, describes alpha rhythm by frequency, amplitude, and stability and after artefact rejection detects pathologic slow activity. All results are displayed as linguistic terms, numerical values and maps of temporal exte…
Thalamic infarctions cause side-specific suppression of vestibular cortex activations.
2005
H2O15-PET was performed during caloric vestibular stimulation of the right and left external ears in eight right-handed patients with acute unilateral infarctions or haemorrhages of the posterolateral thalamus (four right, four left). The posterolateral thalamus is the relay station for ipsi- and contralateral ascending vestibular input to the multiple multisensory vestibular cortex areas. The aim of this study was to evaluate the differential effects of unilateral vestibular thalamic lesions on thalamo-cortical projections, right hemispheric dominance and reciprocal inhibitory visual-vestibular interaction, as well as perceptual and ocular motor consequences during caloric irrigation. The …
Interindividual synchronization of brain activity during live verbal communication
2013
Verbal social interaction plays an important role both in the etiology and treatment of psychiatric disorders. However, the neural basis of social interaction has primarily been studied in the individual brain, neglecting the inter-individual perspective. Here, we show inter-individual neuronal coupling of brain activity during live verbal interaction, by investigating 11 pairs of good female friends who were instructed to speak about autobiographical life events during simultaneous fMRI acquisition. The analysis revealed that the time course of neural activity in areas associated with speech production was coupled with the time course of neural activity in the interlocutor's auditory corte…
Transient and sustained BOLD signal time courses affect the detection of emotion-related brain activation in fMRI.
2014
A tremendous amount of effort has been dedicated to unravel the functional neuroanatomy of the processing and regulation of emotion, resulting in a well-described picture of limbic, para-limbic and prefrontal regions involved. Studies applying functional magnetic resonance imaging (fMRI) often use the block-wise presentation of stimuli with affective content, and conventionally model brain activation as a function of stimulus or task duration. However, there is increasing evidence that regional brain responses may not always translate to task duration and rather show stimulus onset-related transient time courses. We assume that brain regions showing transient responses cannot be detected in…