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111 results on '"Garreffa, G."'

11. An alternative method to record rising temperatures during dental implant site preparation: a preliminary study using bovine bone

Author

Laurito, Domenica, Lamazza, Luca, Garreffa, G., DE BIASE, Alberto, and Biase, A. D.

Subjects
Dental Implants, Dental Instruments, Hot Temperature, dental implant, dental instruments, animals, bone, suture anchors, hot temperature, documentation, dental implants, thermometers, cattle, heat, temperature, lcsh:Public aspects of medicine, Temperature, impianto, lcsh:RA1-1270, Documentation, calore, osso, termometri, Suture Anchors, Animals, Cattle
Abstract

Overheating is constantly mentioned as a risk factor for bone necrosis that could compromise the dental implant primary stability. Uncontrolled thermal injury can result in a fibrous tissue, interpositioned at the implant-bone interface, compromising the long-term prognosis. The methods used to record temperature rise include either direct recording by thermocouple instruments or indirect estimating by infrared thermography. This preliminary study was carried out using bovine bone and a different method of temperatures rising estimation is presented. Two different types of drills were tested using fluoroptic thermometer and the effectiveness of this alternative temperature recording method was evaluated.

Published
2010

23. BOLD signal sign and transient vessels volume variation

Author

Garreffa, G., Colonnese, Claudio, Macri', MARIA ANTONIETTA, Modugno, N., Rocca, R., Calistri, Valentina, De Cesare, E., Venditti, E., and Maraviglia, Bruno

Subjects
Adult, medicine.medical_treatment, Volume variation, Biomedical Engineering, Biophysics, Hemodynamics, Stimulus (physiology), venous blood volume, Neural activity, Valsalva maneuver, medicine, Bold fmri, Humans, Radiology, Nuclear Medicine and imaging, functional mri (fmri), business.industry, Respiration, Apnea, Brain, apnea, Magnetic Resonance Imaging, Oxygen, Anesthesia, Cerebrovascular Circulation, Venous blood flow, medicine.symptom, business, Neuroscience
Abstract

The purpose of this work was to investigate the relation between BOLD signal sign and transient vessels volume variation induced by apnea. This stimulus consisting of breath holding after inspiration is able to induce a light slowing down in venous blood flow like in a sort of Valsalva maneuver. We observed diffuse negative BOLD responding areas at cortical level and a stronger negative response in correspondence of the main sinuses. These phenomena seem to be unrelated to a specific neural activity, appearing to be expressions of a mechanical variation in the hemodynamics. Our study suggests that particular care must be considered in the interpretation of fMRI findings, especially when patients with vascular-related cerebral diseases are involved.

Published
2004

42. Prospettive e limiti dei metodi RM nello studio della funzionalità cerebrale

Author

Mangia, S., Macrì, MA, Garreffa, G., and Maraviglia, B.

Abstract

In questo lavoro vengono affrontati alcuni argomenti che sono al centro della più recente indagine scientifica nel campo delle neuroscienze, in relazione alle metodologie che utilizzano la risonanza magnetica nucleare nello studio della funzionalita cerebrale. Soprattutto grazie alle sue caratteristiche di non invasività, la risonanza magnetica funzionale non soltanto si presenta come un formidabile strumento di ricerca finalizzato alla comprensione delle relazioni che intercorrono tra la struttura cerebrale, la funzionalità cerebrale e le patologie neurologiche, ma si prospetta anche come un'importante tecnica diagnostica di routine clinica.Tuttavia le problematiche legate a tale metodologia sono molteplici, e riguardano da una parte l'interpretazione stessa del segnale rivelato in condizioni di attivazione neuronale, dall'altra la definizione della risoluzione spazio-temporale, della specificità spaziale e della significatività statistica delle mappe di attivazione ottenute.

Published
2000
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50. Perfusion- and BOLD-based fMRI in the study of a human pathological model for task-related flow reductions

Author

Fabrizio Esposito, Federico Giove, Tommaso Scarabino, Girolamo Garreffa, S Mangia, Sossio Cirillo, R Morrone, Bruno Maraviglia, F. Di Salle, Mangia, S, DI SALLE, F, Garreffa, G, Esposito, F, Giove, F, Cirillo, Sossio, Scarabino, T, Morrone, R, and Maraviglia, B.

Subjects
Adult, Intracranial Arteriovenous Malformations, Male, Models, Neurological, arteriovenous malformation, Perfusion scanning, behavioral disciplines and activities, Computer-Assisted, Oxygen Consumption, Adult, Artifacts, Brain Mapping, Cerebrovascular Circulation, physiology, Cerebrovascular Disorders, etiology/physiopathology, Humans, Intracranial Arteriovenous Malformations, physiopathology, Magnetic Resonance Angiography, Magnetic Resonance Imaging, methods/standards, Male, Models, Neurological, Motor Cortex, blood supply/physiopathology, Oxygen Consumption, physiology, Predictive Value of Tests, Reproducibility of Results, Signal Processing, Models, Predictive Value of Tests, medicine, Humans, flow decreases, neuronal deactivation, perfusion mri, blood supply/physiopathology, Brain Mapping, Blood-oxygen-level dependent, General Neuroscience, Motor Cortex, Reproducibility of Results, Signal Processing, Computer-Assisted, Arteriovenous malformation, Gold standard (test), medicine.disease, etiology/physiopathology, Magnetic Resonance Imaging, Cerebrovascular Disorders, Cerebral blood flow, Flow (mathematics), Cerebrovascular Circulation, physiology, Neurological, Signal Processing, methods/standards, physiopathology, Primary motor cortex, Artifacts, Psychology, Perfusion, Neuroscience, Magnetic Resonance Angiography, psychological phenomena and processes
Abstract

In the present work, an arteriovenous malformation was taken as a pathological model for studying task-related flow decreases during a motor task. Combined Blood Oxygen Level Dependent (BOLD)-perfusion experiments were applied in order to evaluate the relative sensitivity of these techniques to task-related reductions in cerebral blood flow (CBF). Results shows that, by matching the sensitivity of the methods (which exhibit a different contrast-to-noise ratio) in the primary motor cortex, the spatial extent of the regions of decreased perfusion signal is larger than those of the BOLD signal reduction. The above finding suggests that perfusion imaging, that already represents a gold standard method in the detection of vascular phenomena, may estimate task-related flow decreases in a functional time-series better than BOLD.

Published
2004

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