MR spectroscopy in human prostate: in vitro and in vivo measurements to optimize new quantification algorithms

Il cancro della prostata (PCa) è il tumore maligno non-cutaneo più diffuso tra gli uomini ed è il secondo tumore che miete più vittime nei paesi occidentali. La necessità di nuove tecniche non invasive per la diagnosi precoce del PCa è aumentata negli anni. 1H-MRS (proton magnetic resonance spectroscopy) e 1H-MRSI (proton magnetic resonance spectroscopy imaging) sono tecniche avanzate di spettroscopia in risonanza magnetica che permettono di individuare presenza di metaboliti come citrato, colina, creatina e in alcuni casi poliammine in uno o più voxel nel tessuto prostatico. L’abbondanza o l’assenza di uno di questi metaboliti rende possibile discriminare un tessuto sano da uno patologico. Le tecniche di spettroscopia RM sono correntemente utilizzate nella pratica clinica per cervello e fegato, con l’utilizzo di software dedicati per l’analisi degli spettri. La quantificazione di metaboliti nella prostata invece può risultare difficile a causa del basso rapporto segnale/rumore (SNR) degli spettri e del forte accoppiamento-j del citrato. Lo scopo principale di questo lavoro è di proporre un software prototipo per la quantificazione automatica di citrato, colina e creatina nella prostata. Lo sviluppo del programma e dei suoi algoritmi è stato portato avanti all’interno dell’IRST (Istituto Romagnolo per lo Studio e la cura dei Tumori) con l’aiuto dell’unità di fisica sanitaria. Il cuore del programma è un algoritmo iterativo per il fit degli spettri che fa uso di simulazioni MRS sviluppate con il pacchetto di librerie GAMMA in C++. L’accuratezza delle quantificazioni è stata testata con dei fantocci realizzati all’interno dei laboratori dell’istituto. Tutte le misure spettroscopiche sono state eseguite con il nuovo scanner Philips Ingenia 3T, una delle machine di risonanza magnetica più avanzate per applicazioni cliniche. Infine, dopo aver eseguito i test in vitro sui fantocci, sono stati acquisiti gli spettri delle prostate di alcuni volontari sani, per testare se il programma fosse in grado di lavorare in condizioni di basso SNR.

Surface cloud radiative forcing from broadband radiation measurements on the Antarctic plateau

Surface based measurements systems play a key role in defining the ground truth for climate modeling and satellite product validation. The Italian-French station of Concordia is operative year round since 2005 at Dome C (75°S, 123°E, 3230 m) on the East Antarctic Plateau. A Baseline Surface Radiation Network (BSRN) site was deployed and became operational since January 2006 to measure downwelling components of the radiation budget, and successively was expanded in April 2007 to measure upwelling radiation. Hence, almost a decade of measurement is now available and suitable to define a statistically significant climatology for the radiation budget of Concordia including eventual trends, by specifically assessing the effects of clouds and water vapor on SW and LW net radiation. A well known and robust clear sky-id algorithm (Long and Ackerman, 2000) has been operationally applied on downwelling SW components to identify cloud free events and to fit a parametric equation to determine clear-sky reference along the Antarctic daylight periods (September to April). A new model for surface broadband albedo has been developed in order to better describe the features the area. Then, a novel clear-sky LW parametrization, based on a-priori assumption about inversion layer structure, combined with daily and annual oscillations of the surface temperature, have been adopted and validated. The longwave based method is successively exploited to extend cloud radiative forcing studies to nighttime period (winter). Results indicated inter-annual and intra-annual warming behaviour, i.e. 13.70 W/m2 on the average, specifically approaching neutral effect in summer, when SW CRF compensates LW CRF, and warming along the rest of the year due prevalentely to CRF induced on the LW component.

Investigation of spectral stability of X-ray tubes by simulations and experimental spectrum measurements

L'obiettivo di questo lavoro è quello di analizzare la stabilità di uno spettro raggi X emesso da un tubo usurato per analisi cardiovascolari, in modo da verificare il suo comportamento. Successivamente questo tipo di analisi sarà effettuata su tubi CT. Per raggiungere questo scopo è stato assemblato un particolare set-up con un rivelatore al germanio criogenico in modo da avere la miglior risoluzione energetica possibile ed alcuni particolari collimatori così da ridurre il flusso fotonico per evitare effetti di pile-up. Il set-up è stato costruito in modo da avere il miglior allineamento possibile nel modo più veloce possibile, e con l'obiettivo di rendere l'intero sistema portabile. Il tubo usato è un SRM Philips tube per analisi cardiovascolari; questa scelta è stata fatta in modo da ridurre al minimo i fattori esterni (ottica elettromagnetica, emettitori) e concentrare l'attenzione solo sugli effetti, causati dalle varie esposizioni, sull'anodo (roughness e bending) e sul comportamento di essi durante il surriscaldamento e successivo raffreddamento del tubo. I risultati mostrano come durante un'esposizione alcuni fattori di usura del tubo possono influire in maniera sostanziale sullo spettro ottenuto e quindi alterare il risultato. Successivamente, nell'elaborato, mediante il software Philips di ricostruzione e simulazione dello spettro si è cercato di riprodurre, variando alcuni parametri, la differenza riscontrata sperimentalmente in modo da poter simulare l'instabilità e correggere i fattori che la causano. I risultati sono interessanti non solo per questo esperimento ma anche in ottica futura, per lo sviluppo di applicazioni come la spectral CT. Il passo successivo sarà quello di spostare l'attenzione su un CT tube e verificare se l'instabilità riscontrata in questo lavoro è persiste anche in una analisi più complessa come quella CT.

Fine particulate matter measurements in Swiss restaurants, cafés and bars: what is the effect of spatial separation between smoking and non-smoking areas?

We performed 124 measurements of particulate matter (PM(2.5)) in 95 hospitality venues such as restaurants, bars, cafés, and a disco, which had differing smoking regulations. We evaluated the impact of spatial separation between smoking and non-smoking areas on mean PM(2.5) concentration, taking relevant characteristics of the venue, such as the type of ventilation or the presence of additional PM(2.5) sources, into account. We differentiated five smoking environments: (i) completely smoke-free location, (ii) non-smoking room spatially separated from a smoking room, (iii) non-smoking area with a smoking area located in the same room, (iv) smoking area with a non-smoking area located in the same room, and (v) smoking location which could be either a room where smoking was allowed that was spatially separated from non-smoking room or a hospitality venue without smoking restriction. In these five groups, the geometric mean PM(2.5) levels were (i) 20.4, (ii) 43.9, (iii) 71.9, (iv) 110.4, and (v) 110.3 microg/m(3), respectively. This study showed that even if non-smoking and smoking areas were spatially separated into two rooms, geometric mean PM(2.5) levels in non-smoking rooms were considerably higher than in completely smoke-free hospitality venues. PRACTICAL IMPLICATIONS: PM(2.5) levels are considerably increased in the non-smoking area if smoking is allowed anywhere in the same location. Even locating the smoking area in another room resulted in a more than doubling of the PM(2.5) levels in the non-smoking room compared with venues where smoking was not allowed at all. In practice, spatial separation of rooms where smoking is allowed does not prevent exposure to environmental tobacco smoke in nearby non-smoking areas.

Do centimetres matter? Self-reported versus estimated height measurements in parents

An impressive discrepancy between reported and measured parental height is often observed. The aims of this study were: (a) to assess whether there is a significant difference between the reported and measured parental height; (b) to focus on the reported and, thereafter, measured height of the partner; (c) to analyse its impact on the calculated target height range.

Reproducibility and validity of video screen measurements of gait in children with spastic cerebral palsy

PURPOSE: To determine the reproducibility and validity of video screen measurement (VSM) of sagittal plane joint angles during gait. METHODS: 17 children with spastic cerebral palsy walked on a 10m walkway. Videos were recorded and 3d-instrumented gait analysis was performed. Two investigators measured six sagittal joint/segment angles (shank, ankle, knee, hip, pelvis, and trunk) using a custom-made software package. The intra- and interrater reproducibility were expressed by the intraclass correlation coefficient (ICC), standard error of measurements (SEM) and smallest detectable difference (SDD). The agreement between VSM and 3d joint angles was illustrated by Bland-Altman plots and limits of agreement (LoA). RESULTS: Regarding the intrarater reproducibility of VSM, the ICC ranged from 0.99 (shank) to 0.58 (trunk), the SEM from 0.81 degrees (shank) to 5.97 degrees (trunk) and the SDD from 1.80 degrees (shank) to 16.55 degrees (trunk). Regarding the interrater reproducibility, the ICC ranged from 0.99 (shank) to 0.48 (trunk), the SEM from 0.70 degrees (shank) to 6.78 degrees (trunk) and the SDD from 1.95 degrees (shank) to 18.8 degrees (trunk). The LoA between VSM and 3d data ranged from 0.4+/-13.4 degrees (knee extension stance) to 12.0+/-14.6 degrees (ankle dorsiflexion swing). CONCLUSION: When performed by the same observer, VSM mostly allows the detection of relevant changes after an intervention. However, VSM angles differ from 3d-IGA and do not reflect the real sagittal joint position, probably due to the additional movements in the other planes.

Reproducibility of retinal thickness measurements in patients with age-related macular degeneration using 3D Fourier-domain optical coherence tomography (OCT) (Topcon 3D-OCT 1000)

Conventional time-domain optical coherence tomography (OCT) has become an important tool for following dry or exudative age-related macular degeneration (AMD). Fourier-domain three-dimensional (3D) OCT was recently introduced. This study tested the reproducibility of 3D-OCT retinal thickness measurements in patients with dry and exudative AMD.

Family satisfaction with critical care: measurements and messages

PURPOSE OF REVIEW: Family satisfaction in the ICU reflects the extent to which perceived needs and expectations of family members of critically ill patients are met by healthcare professionals. Here, we present recently developed tools to assess family satisfaction, with a special focus on their psychometric properties. Assessing family satisfaction, however, is not of much use if it is not followed by interpretation of the results and, if needed, consecutive measures to improve care of the patients and their families, or improvement in communication and decision-making. Accordingly, this review will outline recent findings in this field. Finally, possible areas of future research are addressed. RECENT FINDINGS: To assess family satisfaction in the ICU, several domains deserve attention. They include, among others, care of the patient, counseling and emotional support of family members, information and decision-making. Overall, communication between physicians or nurses and members of the family remains a key topic, and there are many opportunities to improve. They include not only communication style, timing and appropriate wording but also, for example, assessments to see if information was adequately received and also understood. Whether unfulfilled needs of individual members of the family or of the family as a social system result in negative long-term sequels remains an open question. SUMMARY: Assessing and analyzing family satisfaction in the ICU ultimately will support healthcare professionals in their continuing effort to improve care of critically ill patients and their families.

Feasibility of texture analysis for the assessment of biochemical changes in meniscal tissue on T1 maps calculated from delayed gadolinium-enhanced magnetic resonance imaging of cartilage data: comparison with conventional relaxation time measurements

To (1) establish the feasibility of texture analysis for the in vivo assessment of biochemical changes in meniscal tissue on delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), and (2) compare textural with conventional T1 relaxation time measurements calculated from dGEMRIC data ("T1(Gd) relaxation times").

Single-shot electron bunch length measurements using a spatial electro-optical autocorrelation interferometer

A spatial, electro-optical autocorrelation (EOA) interferometer using the vertically polarized lobes of coherent transition radiation (CTR) has been developed as a single-shot electron bunch length monitor at an optical beam port downstream the 100 MeV preinjector LINAC of the Swiss Light Source. This EOA monitor combines the advantages of step-scan interferometers (high temporal resolution) [D. Mihalcea et al., Phys. Rev. ST Accel. Beams 9, 082801 (2006) and T. Takahashi and K. Takami, Infrared Phys. Technol. 51, 363 (2008)] and terahertz-gating technologies [U. Schmidhammer et al., Appl. Phys. B: Lasers Opt. 94, 95 (2009) and B. Steffen et al., Phys. Rev. ST Accel. Beams 12, 032802 (2009)] (fast response), providing the possibility to tune the accelerator with an online bunch length diagnostics. While a proof of principle of the spatial interferometer was achieved by step-scan measurements with far-infrared detectors, the single-shot capability of the monitor has been demonstrated by electro-optical correlation of the spatial CTR interference pattern with fairly long (500 ps) neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulses in a ZnTe crystal. In single-shot operation, variations of the bunch length between 1.5 and 4 ps due to different phase settings of the LINAC bunching cavities have been measured with subpicosecond time resolution.

[Which clinical symptoms suggest distinct autoantibody measurements?]

The detection of autoantibodies is an important cornerstone in the diagnosis of systemic autoimmune disorders such as autoimmune connectivitides and small vessel vasculitides. Antinuclear antibodies (ANAs ) and antineutrophil cytoplasmic antibodies (c+p-ANCAs) are appropriate diagnostic screening tools for autoimmune connectivitides and small vessel vasculitides. For economic and intellectual/didactic reasons more extensive autoantibody diagnostics should be performed only in particular situations when patients history and clinical exam lead to strong diagnostic suspicion.

Cervical muscle area measurements in acute whiplash patients and controls

To quantitatively compare the muscle cross-sectional areas (CSAs) of the cervical muscles in symptomatic acute whiplash patients versus healthy controls. We hypothesized, that symptomatic whiplash patients have smaller cervical muscle CSAs than matched controls and that smaller cervical muscle CSAs in women might explain that women more frequently are symptomatic after whiplash injury than men.

Precision of endodontic working length measurements: a pilot investigation comparing cone-beam computed tomography scanning with standard measurement techniques

The objective of this pilot investigation was to evaluate the utility and precision of already existing limited cone-beam computed tomography (CBCT) scans in measuring the endodontic working length, and to compare it with standard clinical procedures.