Valentina Quaresima
University of L'Aquila
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Featured researches published by Valentina Quaresima.
NeuroImage | 2012
Marco Ferrari; Valentina Quaresima
This review is aimed at celebrating the upcoming 20th anniversary of the birth of human functional near-infrared spectroscopy (fNIRS). After the discovery in 1992 that the functional activation of the human cerebral cortex (due to oxygenation and hemodynamic changes) can be explored by NIRS, human functional brain mapping research has gained a new dimension. fNIRS or optical topography, or near-infrared imaging or diffuse optical imaging is used mainly to detect simultaneous changes in optical properties of the human cortex from multiple measurement sites and displays the results in the form of a map or image over a specific area. In order to place current fNIRS research in its proper context, this paper presents a brief historical overview of the events that have shaped the present status of fNIRS. In particular, technological progresses of fNIRS are highlighted (i.e., from single-site to multi-site functional cortical measurements (images)), introduction of the commercial multi-channel systems, recent commercial wireless instrumentation and more advanced prototypes.
Journal of Biomedical Optics | 2007
Takafumi Hamaoka; Kevin K. McCully; Valentina Quaresima; Katsuyuki Yamamoto; Britton Chance
Near-infrared spectroscopy (NIRS) was initiated in 1977 by Jobsis as a simple, noninvasive method for measuring the presence of oxygen in muscle and other tissues in vivo. This review honoring Jobsis highlights the progress that has been made in developing and adapting NIRS and NIR imaging (NIRI) technologies for evaluating skeletal muscle O(2) dynamics and oxidative energy metabolism. Development of NIRS/NIRI technologies has included novel approaches to quantification of the signal, as well as the addition of multiple source detector pairs for imaging. Adaptation of NIRS technology has focused on the validity and reliability of NIRS measurements. NIRS measurements have been extended to resting, ischemic, localized exercise, and whole body exercise conditions. In addition, NIRS technology has been applied to the study of a number of chronic health conditions, including patients with chronic heart failure, peripheral vascular disease, chronic obstructive pulmonary disease, varying muscle diseases, spinal cord injury, and renal failure. As NIRS technology continues to evolve, the study of skeletal muscle function with NIRS first illuminated by Jobsis continues to be bright.
Photochemistry and Photobiology | 1998
Valentina Quaresima; Stephen J. Matcher; Marco Ferrari
Near‐infrared spectroscopy has been used to quantify the composition of healthy female breast tissue in vivo. By collecting transillumination spectra in the wavelength range 680–1100 nm at 7–9 positions on the breasts of five female volunteers, an attempt was made to quantify the intra‐ and intersubject variability of breast composition. The dominant absorbers are water, lipids and hemoglobin. Hemoglobin concentration in the breast is substantially lower than that in the brain or muscle (less than 10 μM). The measured deoxyhemoglobin concentration can vary by up to 100% between different positions on the same breast. Water and lipid concentrations can show similar variability. Phantom and simulation studies demonstrate that this variability is not due to the effects of tissue boundaries on the measurements. The low hemoglobin concentration implies that optical breast imaging should be performed at wavelengths below about 850 nm to ensure that the image contrast comes predominantly from hemoglobin. Intrasubject variability could have implications for the ability of optical imaging to discern tumors from background contrast variations.
Brain and Language | 2012
Valentina Quaresima; Silvia Bisconti; Marco Ferrari
Upon stimulation, real time maps of cortical hemodynamic responses can be obtained by non-invasive functional near-infrared spectroscopy (fNIRS) which measures changes in oxygenated and deoxygenated hemoglobin after positioning multiple sources and detectors over the human scalp. The current commercially available transportable fNIRS systems have a time resolution of 1-10 Hz, a depth sensitivity of about 1.5 cm, and a spatial resolution of about 1cm. The goal of this brief review is to report infants, children and adults fNIRS language studies. Since 1998, 60 studies have been published on cortical activation in the brains classic language areas in children/adults as well as newborns using fNIRS instrumentations of different complexity. In addition, the basic principles of fNIRS including features, strengths, advantages, and limitations are summarized in terms that can be understood even by non specialists. Future prospects of fNIRS in the field of language processing imaging are highlighted.
Journal of Biomedical Optics | 2000
Valentina Quaresima; Simona Sacco; Rocco Totaro; Marco Ferrari
Spatially resolved spectroscopy (SRS) is a new near infrared spectroscopy (NIRS) method that, using the multi-distance approach, measures local cerebral cortex hemoglobin oxygen saturation [J. Matcher, P. Kirkpatrick, K. Nahid, M. Cope, and D. T. Delpy, Proc. SPIE 2389, 486-495 (1995)]. Using a conventional continuous wave NIRS photometer, cerebral venous oxygen saturation (SvO2) can be calculated from oxyhemoglobin and total hemoglobin rise induced by partial occlusion of jugular vein [C. E. Elwell, S. J. Matcher, L. Tyszczuk, J. H. Meek, and D. T. Delpy, Adv. Exp. Med. Biol. 411, 453-460 (1997)]. The aim of this study was to compare direct measurements of forehead tissue oxygenation index (TOI) with the calculated SvO2 during venous occlusion in 16 adult volunteers using a clinical two-channel SRS oximeter (NIRO-300). Measured TOI and calculated SvO2 values of either right or left forehead did not significantly differ. A good agreement between the two NIRS methods was also demonstrated. On 16 other subjects, no significant differences were found between the right and left forehead TOI values measured simultaneously, and between the TOI values measured by channel 1 or 2 on the same side. The results confirm that cerebral cortex hemoglobin oxygen saturation, measured directly by the SRS method, reflects predominantly the saturation of the intracranial venous compartment of circulation.
Journal of Biomedical Optics | 2005
Valentina Quaresima; Marco Ferrari; Alessandro Torricelli; Lorenzo Spinelli; Antonio Pifferi; Rinaldo Cubeddu
The letter-fluency task-induced response over the prefrontal cortex is investigated bilaterally on eight subjects using a recently developed compact, eight-channel, time-resolved, near-IR system. The cross-subject mean values of prefrontal cortex oxygen saturation (SO2) were 68.8+/-3.2% (right) and 71.0+/-3.6% (left), and of total hemoglobin concentration (tHb) were 69.6+/-9.6 microM (right) and 69.5+/-9.9 microM (left). The typical cortical activation response to the cognitive task [characterized by an increase in oxyhemoglobin (O2Hb) with a concurrent decrease in deoxyhemoglobin (HHb)] at each measurement point is observed in only four subjects. In this subset, the amplitude of the O2Hb increase and HHb decrease is uniform over each prefrontal cortex area and comparable between the two hemispheres. These findings agree with previous studies using continuous wave functional near-IR spectroscopy and functional magnetic resonance imaging, therefore demonstrating the potential of a time-resolved spectroscopy approach. In addition, a significant increase in SO2 levels was observed in the right (1.1+/-0.5%) compared to left side of the prefrontal cortex (0.9+/-0.5%) (P=0.005). A different pattern of cortical activation (characterized by the lack of HHb decrease or even increased HHb) was observed in the remaining subjects.
Brain Research Bulletin | 2002
Valentina Quaresima; Marco Ferrari; Marco C. van der Sluijs; Jan Menssen; W.N.J.M. Colier
The organisation of language in the brain of multilingual people remains controversial. Using a high temporal resolution 12-channel near-infrared continuous wave spectroscopy system, we have demonstrated that it is possible to monitor non-invasively, comfortably and, without the interferences due to intrinsic limitations of positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), cortical oxygenation changes in the Brocas area in response to translation of short sentences and language switching. Eight Dutch students proficient in English translated aloud from their native language into English or vice versa or alternating (switching) short visually presented sentences. These tasks provoked, in the left inferior frontal cortex which includes the Brocas area, a consistent and incremental rise in oxyhaemoglobin accompanied by a smaller decrease in deoxyhaemoglobin. The investigated cortical areas surrounding the Brocas area showed no uniform and consistent oxygenation changes upon the three different translation tasks. These results confirm that Brocas area is involved in the translation process and its so called activation is unaffected by the direction of the translation. In addition, these results strengthen the role of near-infrared multi-point measurements as a powerful tool for investigating the spatial and temporal features of the cortical oxygenation changes during language processing.
Journal of Near Infrared Spectroscopy | 2012
Marco Ferrari; Valentina Quaresima
In the early 1960s, Norris introduced near infrared (NIR) spectroscopy (700–2500 nm) as an analytical technique for agricultural products. In 1977, Jöbsis founded in vivo medical NIR spectroscopy, reporting that the relatively high degree of transparency of brain tissue in the NIR spectral window (700–1000 nm) enables safe real-time non-invasive detection of regional haemoglobin oxygenation using trans-illumination spectroscopy. In order to place current medical NIR spectroscopy in its proper perspective, this review provides a snapshot of the roots of the discovery and the early years of medical NIR spectroscopy research and development. Starting in 1992, the opportunity of measuring quantitatively, by different NIR spectroscopy techniques, regional oxy-haemoglobin saturation by NIR oximetry, it is possible to monitor brain/muscle reserve capacity following tissue oxygen extraction in different pathophysiological conditions. This review reports the status of the current commercial oximeters (including wireless instrumentation) and their main clinical and physiological applications. In the last decade, NIR spectroscopy brain oximetry has obtained significant clinical relevance as suggested by the more than 10,000 instruments sold and the high number of related scientific publications. The most relevant clinical application is represented by the evaluation of cerebral oxy-haemoglobin saturation during adult cardiac surgery and cardiopulmonary bypass. Many commercial oximeters are presently available. However, their relatively poor precision and the lack of standardisation amongst the different instruments suggest that further technological advances are required before NIR spectroscopy oximetry can be adopted more widely under the “guidelines” of regulatory authorities.
Journal of Perinatology | 2005
Patrizia Zaramella; Federica Freato; Valentina Quaresima; Marco Ferrari; Andrea Vianello; Diego Giongo; Lorena Conte; Lino Chiandetti
OBJECTIVE:In critically ill neonates, peripheral perfusion and oxygenation assessment may provide indirect information on the circulatory failure of vital organs during circulatory shock. The development of pulse oximetry has recently made it possible to calculate the perfusion index (PI), obtained from the ratio between the pulsatile and nonpulsatile signals of absorbed light. The main goals of this study were: (1) to study foot PI; and (2) to evaluate the relationship between foot PI, obtained continuously by pulse oximetry, and a number of variables, i.e. blood flow (BF), oxygen delivery (DO2), oxygen consumption (VO2), and fractional oxygen extraction (FOE), measured indirectly by near-infrared spectroscopy (NIRS) on the calf in 43 healthy term neonates (weight 3474.6±466.9 g; gestational age 39.1±1.4 weeks).STUDY DESIGN:Calf BF, DO2 and VO2 were assessed by NIRS on short-lived venous and arterial occlusion maneuvers. PI was measured on the contralateral foot.RESULTS:Foot PI was 1.26±0.39. There was a positive correlation between foot PI and both calf BF (r=0.32, p=0.03) and DO2 (r=0.32, p=0.03), but no correlation was found between foot PI and calf FOE and between foot PI and VO2.CONCLUSIONS:In the neonatal intensive care unit, continuously measuring foot PI by pulse oximetry seems clinically more feasible for peripheral perfusion monitoring than spot measurements of the calf BF and/or VO2 by indirect NIRS.
Physics in Medicine and Biology | 2004
Alessandro Torricelli; Valentina Quaresima; Antonio Pifferi; G. Biscotti; Lorenzo Spinelli; Paola Taroni; Marco Ferrari; Rinaldo Cubeddu
A compact and fast multi-channel time-resolved near-infrared spectroscopy system for tissue oximetry was developed. It employs semiconductor laser and fibre optics for delivery of optical signals. Photons are collected by eight 1 mm fibres and detected by a multianode photomultiplier. A time-correlated single photon counting board is used for the parallel acquisition of time-resolved reflectance curves. Estimate of the reduced scattering coefficient is achieved by fitting with a standard model of diffusion theory, while the modified Lambert-Beer law is used to assess the absorption coefficient. In vivo measurements were performed on five healthy volunteers to monitor spatial changes in calf muscle (medial and lateral gastrocnemius; MG, LG) oxygen saturation (SmO2) and total haemoglobin concentration (tHb) during dynamic plantar flexion exercise performed at 50% of the maximal voluntary contraction. At rest SmO2 was 73.0 +/- 0.9 and 70.5 +/- 1.7% in MG and LG, respectively (P = 0.045). At the end of the exercise, SmO2 decreased (69.1 +/- 1.8 and 63.8 +/- 2.1% in MG and LG, respectively; P < 0.01). The LG desaturation was greater than the MG desaturation (P < 0.02). These results strengthen the role of time-resolved near-infrared spectroscopy as a powerful tool for investigating the spatial and temporal features of muscle SmO2 and tHb.