99mTc thyroid imaging system using multiple imaging plates

A system for taking static thyroid ^99mTc images was devised by using multiple imaging plates (IPs) and a low-energy high resolution collimator. System spatial resolution of the IP systems and the gamma camera was determined by referring to standards set by the National Electrical Manufacturers Association. Sensitivity was represented by using lower detection limits (LDLs). The sensitivity and resolution of IP systems using 16 IP probes connecting two collimators and 9 IPs were determined by using a 20 ml thyroid phantom, and compared with the sensitivity of gamma cameras. The sensitivity of the IP systems increased in proportion to the number of IPs. The sensitivity and resolution of a probe using 6 IPs and a high resolution collimator were equivalent to or superior to the gamma camera for taking static thyroid ^99mTc images. IP systems can be applied clinically as mobile static nuclear imaging devices. The performance of IP systems should be thoroughly investigated for combinations of various collimators and the number of IPs in order to verify their efficacy for imaging all organs.     

Determination of inflection points of CyberKnife dose profiles within acceptability criteria of deviations in measurements

AimThe aim of this study was to determine the Inflection Points (IPs) of flattening filter free (FFF) CyberKnife dose profiles for cone-based streotactic radiotherapy. In addition, dosimetric field sizes were determined.BackgroundThe increased need for treatment in the early stages of cancer necessitated the treatment of smaller tumors. However, efforts in that direction required the modeling accuracy of the beam. Removal of the flattening filter (FF) from the path of x-ray beam has provided the solution to those efforts, but required a different normalization approach for the beam to ensure the delivery of the dose accurately. As a solution, researchers proposed a normalization factor based on IPs.Materials and methodsMeasurements using microDiamond (PTW 60019), Diode SRS (PTW 60018) and Monte Carlo (MC) calculations of dose profiles were completed at SAD 80 cm and 5 cm depth for 15–60 mm cones. Performance analysis of detectors with respect to MC calculation was carried out. Gamma evaluation method was used to determine achievable acceptability criteria for FFF CyberKnife beams.ResultsAcceptability within (3%–0.5 mm) was found to be anachievable criterion for all dose profile measurements of the cone beams used in this study. To determine the IP, the first and second derivatives of the dose profile were determined via the cubic spline interpolation technique.ConclusionDerivatives of the interpolated profiles showed that locations of IPs and 50% isodose points coincide.     

Determination of an inflection point for a dosimetric analysis of unflattened beam using the first principle of derivatives by python code programming

BackgroundPractice of Unflattened or Flattening filter free (FFF) beam has become the high dose standard in radiotherapy (RT), such as stereotactic radio-surgery (SRS) and stereotactic radiotherapy (SRT). The removal of a flattening filter (FF) from the path of a photon beam alters the characteristics of FFF beam. Since the conventional route for dosimetric analysis of FF beam cannot be applied to FFF beam, the procedure of analyzing beam characteristics for FFF beam based on inflection points (IPs) is used. IP is a point where the concavity change observed corresponds to its change in sign (±) of the second derivative.AimThe objective of the study is to determine IPs for dosimetric analysis of the FFF beam profile.Methods and materialsIn this study, IPs are determined through the python code programming based on the mathematical first principle of the derivative. They are compared with IPs estimated by the conventional graphical manual method using Microsoft Excel (MS). IPs and their dependent dosimetric parameters determined by both mathematical and graphical manual methods are compared.ResultPercentage differences between the IPs determined by both methods, for 6MVFFF inline and crossline beam profile are found to be 2.7% and 0.8% respectively. Similarly, the average penumbra differences for 6MVFFF inline and crossline beam profile are found to be 0.15 mm and 0.9 mm, respectively. However, differences in the field width between both methods are found insignificant.ConclusionGraphical manual method is very time-consuming, tedious and user dependent. However, the mathematical method through python code programming is more precise, faster and independent of individual users.     

Jaw elevator silent periods in complete denture wearers and dentate individuals

Functional meaning and underlying mechanisms of jaw elevator silent period (SP) have still not been completely understood. Since complete denture wearers (CDWs) have no periodontal receptors in their jaws, the aim was to examine SPs in CDWs and to compare it with dentate individuals (DIs).Thirty six DIs (skeletal/occlusal Class I) and 24 eugnath CDWs participated. EMG signals were registered using the EMGA-1 apparatus from the left and the right side anterior temporalis (ATM) and masseter muscles (MM). Ten registrations of an open-close-clench (OCC) cycle were obtained for each individual. DIs had the average latency between 12.5 and 12.9 ms and always one single short inhibitory pause (IP) with complete inhibition of motoneurons (20.1–21.1 ms). On the other hand, in CDWs various types of SPs emerged: single or single prolonged SPs, double SPs, SPs with three IPs, periods of depressed muscle activity following the first, or the second IP, SPs with relative inhibition of motoneurons or even in several registrations the SP was missing. Unless more than one IP emerged, complete duration of inhibitory pauses (CDIP) was measured. CDIP varied from 37.17 to 42.49 ms. Average latencies were from 16.22 to 16.76 ms. Based on the results of this study it is obvious that both, the duration and the latencies were significantly longer in CDWs than in DIs (p < 0.05), which can be explained by different mechanisms responsible for the muscle reflex behaviour.     

Comparison of CT artifacts and image recognition of various fiducial markers including two types of thinner fiducial markers for CyberKnife treatment

AimThe aim of the study was to evaluate computed tomography (CT) artifacts and image recognition of the CyberKnife system. Regarding fiducial markers, VISICOIL of 0.5 mm × 5.0 mm and 0.75 mm × 5.0 mm, ball-shaped Gold Anchor (GA) of 0.28 mm × 10 mm and 0.28 mm × 20 mm, were compared with the standard cylinder marker of 0.9 mm × 3.0 mm (ACCULOC).BackgroundRecently, various kinds of commercial fiducial markers have been available in CyberKnife treatment.Materials and methodsThe CT images of a water equivalent gel with each fiducial marker were acquired for the evaluation of CT artifacts. The evaluation was performed using the standard deviation of Hounsfield Unit (HU) value for a rectangle region near the fiducial marker. Then, to evaluate the image recognition, each fiducial marker was located to overlap in the target locating system (TLS) for the two sites; the vertebral bone and the pubic bone.ResultsFor CT artifacts, the standard deviations of the VISICOIL of 0.5 mm × 5.0 mm was the smallest. The image recognition of four fiducial markers had a value close to the standard cylinder marker and was feasible for common use, but was slightly poorer when using GA of 0.28 mm × 10 mm in the dynamic conditions.ConclusionOur results indicated that VISICOIL 0.5 × 5.0 mm and the GAs can be used nearly always for CyberKnife treatment in spite of their much thinner needles than those of cylinder types.     

Dosimetric impact of 4DCT artifact in carbon-ion scanning beam treatment: Worst case analysis in lung and liver treatments

IntroductionWe evaluated the impact of 4DCT artifacts on carbon-ion pencil beam scanning dose distributions in lung and liver treatment.Methods & materials4DCT was performed in 20 liver and lung patients using area-detector CT (original 4DCT). 4DCT acquisition by multi-detector row CT was simulated using original 4DCT by selecting other phases randomly (plus/minus 20% phases). Since tumor position can move over the respiratory range in original 4DCT, mid-exhalation was set as reference phase. Total prescribed dose of 60 Gy (RBE) was delivered to the clinical target volume (CTV). Reference dose distribution was calculated with the original CT, and actual dose distributions were calculated with treatment planning parameters optimized using the simulated CT (simulated dose). Dose distribution was calculated by substituting these parameters into the original CT.ResultsFor liver cases, CTV-D95 and CTV-Dmin values for the reference dose were 97.6 ± 0.5% and 89.8 ± 0.6% of prescribed dose, respectively. Values for the simulated dose were significantly degraded, to 88.6 ± 14.0% and 46.3 ± 26.7%, respectively. Dose assessment results for lung cases were 84.8 ± 12.8% and 58.0 ± 24.5% for the simulated dose, showing significant degradation over the reference dose of 95.1 ± 1.5% and 87.0 ± 2.2%, respectively.Conclusions4DCT image quality should be closely checked to minimize degradation of dose conformation due to 4DCT artifacts. Medical staff should pay particular attention to checking the quality of 4DCT images as a function of respiratory phase, because it is difficult to recognize 4DCT artifact on a single phase in some cases     

Plasma leptin level predicts hematoma growth and early neurological deterioration after acute intracerebral hemorrhage

Higher plasma leptin levels have been associated with poor clinical outcomes after intracerebral hemorrhage. Nevertheless, their links with hematoma growth and early neurological deterioration are unknown. Therefore, we aimed to investigate the relationship between plasma leptin levels, hematoma growth, and early neurological deterioration in patients with acute intracerebral hemorrhage. We prospectively studied 102 consecutive patients with acute spontaneous basal ganglia hemorrhage presenting within 6 h from symptoms onset. Significant hematoma growth was defined as hematoma enlargement >33% at 24 h. Early neurological deterioration was defined as an increase of ≥4 points in National Institute of Health Stroke Scale score at 24 h from symptoms onset. We measured plasma leptin levels on admission using an enzyme-linked immunosorbent assay in a blinded fashion. In multivariate logistic regression analysis, plasma leptin level emerged as the independent predictor of hematoma growth (odds ratio, 1.182; 95% confidence interval, 1.061–2.598; P = 0.008) and early neurological deterioration (odds ratio, 1.193; 95% confidence interval, 1.075–2.873; P = 0.004). Using receiver operating characteristic curves, we calculated areas under the curve for hematoma growth (area under curve, 0.844; 95% confidence interval, 0.759–0.908) and early neurological deterioration (area under curve, 0.857; 95% confidence interval, 0.774–0.918). The predictive performance of leptin was similar to, but did not obviously improve that of hematoma volume. Thus, leptin may help in the prediction of hematoma growth and early neurological deterioration after intracerebral hemorrhage.     

Comparison between new-generation SiPM-based and conventional PMT-based TOF-PET/CT

PurposeThis study aimed to determine whether the SiPM-PET/CT, Discovery MI (DMI) performs better than the PMT-PET/CT system, Discovery 710 (D710).MethodsThe physical performance of both systems was evaluated using NEMA NU 2 standards. Contrast (%), uniformity and image noise (%) are criteria proposed by the Japanese Society of Nuclear Medicine (JSNM) for phantom tests and were determined in images acquired from Hoffman and uniform phantoms using the DMI and D710. Brain and whole-body [¹⁸F]FDG images were also acquired from a healthy male using the DMI and D710.ResultsThe spatial resolution at 1.0 cm off-center in the DMI and D710 was 3.91 and 4.52 mm, respectively. The sensitivity of the DMI and D710 was 12.62 and 7.50 cps/kBq, respectively. The observed peak noise-equivalent count rates were 185.6 kcps at 22.5 kBq/mL and 137.0 kcps at 29.0 kBq/mL, and the scatter fractions were 42.1% and 37.9% in the DMI and D710, respectively. The D710 had better contrast recovery and lower background variability. Contrast, uniformity and image noise in the DMI were 61.0%, 0.0225, and 7.85%, respectively. These outcomes were better than those derived from the D710 and satisfied the JSNM criteria. Brain images acquired by the DMI had better grey-to-white matter contrast and lower image noise at the edge of axial field of view.ConclusionsThe DMI offers better sensitivity, performance under conditions of high count rates and image quality than the conventional PMT-PET/CT system, D710.     

Applications cliniques de l’imagerie hybride TEP-IRM

This paper reports the results of a preliminary study evaluating the feasibility and performance of a first whole body hybrid PET/MR scanner allowing sequential acquisition of co-registered MR and PET images. Sixty-two patients underwent whole body PET/MR imaging immediately after a clinical PET/CT. The hybrid device consists of a 3T MR and a time-of-flight PET scanner sharing a single bed allowing sequential acquisition of co-registered MR and PET images. Imaging protocols included a whole body MR used for attenuation correction of PET followed by high-resolution diagnostic MR. Image analysis included visual identification of radiotracer uptake in tumors and measurement of standardized uptake values (SUV) in tumoral lesions and in normal organs. PET images acquired in the PET/MR with a delay of 85 ± 22 minutes (range 49–120 minutes) showed perfect correlation and identical diagnostic quality compared to PET/CT. In 42 patients (68%), additional high-resolution MR sequences were acquired for clinical diagnosis showing excellent quality without any visually detectable artifacts. SUV measurements of tumor lesions obtained after correction with MR attenuation maps showed an excellent correlation with PET/CT (R² = 0.89 and R² = 0.95 for mean and maximum tissue uptake respectively). Due to the delay between the two studies, changes in tracer uptake biodistribution of normal tissue were observed. Our preliminary data show that whole body PET/MR is clinically applicable in oncologic patients yielding a comparable diagnostic performance as PET/CT with respect to lesion detection and localization.     

Evaluation of automatic image quality assessment in chest CT – A human cadaver study

PurposeThe evaluation of clinical image quality (IQ) is important to optimize CT protocols and to keep patient doses as low as reasonably achievable. Considering the significant amount of effort needed for human observer studies, automatic IQ tools are a promising alternative. The purpose of this study was to evaluate automatic IQ assessment in chest CT using Thiel embalmed cadavers.MethodsChest CT’s of Thiel embalmed cadavers were acquired at different exposures. Clinical IQ was determined by performing a visual grading analysis. Physical-technical IQ (noise, contrast-to-noise and contrast-detail) was assessed in a Catphan phantom. Soft and sharp reconstructions were made with filtered back projection and two strengths of iterative reconstruction. In addition to the classical IQ metrics, an automatic algorithm was used to calculate image quality scores (IQs). To be able to compare datasets reconstructed with different kernels, the IQs values were normalized.ResultsGood correlations were found between IQs and the measured physical-technical image quality: noise (ρ = −1.00), contrast-to-noise (ρ = 1.00) and contrast-detail (ρ = 0.96). The correlation coefficients between IQs and the observed clinical image quality of soft and sharp reconstructions were 0.88 and 0.93, respectively.ConclusionsThe automatic scoring algorithm is a promising tool for the evaluation of thoracic CT scans in daily clinical practice. It allows monitoring of the image quality of a chest protocol over time, without human intervention. Different reconstruction kernels can be compared after normalization of the IQs.     

Effects of ozone fumigation on cotton (Gossypium hirsutum L.) morphology,anatomy, physiology,yield and qualitative characteristics of fibers

This experiment was conducted to study the effect of high ozone concentrations on two cotton (Gossypium hirsutum L.) cultivars. Two cotton cultivars (Romanos and Allegria) were exposed to control (CF < 4 ppb O₃) and 100 ppb O₃. Plant exposure to ozone began eight days after emergence and was interrupted one day before removing the leaves, to calculate the leaf area. Plants were exposed to ozone 7 h/day, in closed and controlled-environment chambers, during their illumination with artificial visible light.In comparison to control plants, plants exposed to O₃ showed chlorotic and necrotic patches on their leaves, increased stomatal or epidermal cell density and yellowness of cotton fibers. Elevated ozone concentration did not have a significant effect on stomatal width, total leaf thickness and thickness of histological components of leaves. Exposure to ozone concentration reduced non-glandular hair density of main leaf veins, plant height, mainstem internode length, chlorophyll content, net photosynthetic rate, stomatal conductance and length and area of bracts and petals. Elevated ozone treatment reduced the maximum length of staminal tube, anther number, pollen grain germination, leaf area, leaf dry weight, boll number, raw cotton weight, total branch length, dry weight of the mainstem–branches–bracts–carpophylls and of root dry weight. Furthermore, exposure to O₃ reduced the seed weight, the lint weight, the yield, the ratio of lint weight to seed weight, the fiber strength, the micronaire, the maturity index and the fiber uniformity index values. This study shows that the exposure to high ozone concentrations mainly affected the rate of photosynthesis, raw cotton weight and strength of cotton fibers.     

Effect of the exposure to methyl-β-cyclodextrin prior to chilling or vitrification on the viability of bovine immature oocytes

The present study aimed to evaluate the effect of methyl-β-cyclodextrin (MβCD) as a cholesterol loader to change oocyte plasma membrane and increase its tolerance toward cryopreservation. The first and second experiments were conducted to investigate if MβCD could improve nuclear and cytoplasmic maturation after oocyte exposure to cold stress for 10 or 30 min, respectively. No differences (P > 0.05) in either experiment in the metaphase II (MII) rate of oocytes exposed to MβCD and cold stress; but these oocytes presented lower maturation rates than control groups. In the second experiment, a lower percentage of oocytes showed degenerated chromatin (P < 0.05) after exposure to 2 mg/mL of MβCD compared to the group exposed to 0 mg/mL. However, no differences among treatments were observed in cytoplasmic maturation. Groups exposed to cold stress demonstrated a lower (P < 0.05) capacity for embryonic development compared to the control groups. In the third experiment immature oocytes were exposed to MβCD and then, vitrified (cryotop). After warming, we observed that the ability to reach MII and chromatin degeneration were altered (P < 0.05) by MβCD. The blastocysts rate (P < 0.05) on D7 was higher in the 2 mg/mL MβCD group, but an identical finding was not observed on D8 (P > 0.05). Chromatin degeneration was higher in the vitrification groups. We conclude that MβCD improved nuclear maturation by reducing oocyte degeneration after cold stress or vitrification; however, more studies are required to clarify the usefulness of MβCD use in oocyte cryopreservation.     

Effect of Astragalus polysaccharides on expression of TNF-α, IL-1β and NFATc4 in a rat model of experimental colitis

AimAstragalus membranaceus is a Chinese medicinal herb and has been shown to improve hapten-induced experimental colitis. One of its major components is polysaccharides. We investigated the effect of Astragalus polysaccharides (APS) on expression of TNF-α, IL-1β and NFATc4 in a rat model of experimental colitis.MethodsThe experimental colitis model was induced by TNBS. Forty five rats were divided into five groups (n = 9): Normal control group, receiving ethanol vehicle with no TNBS during induction and IP saline injection during treatment; TNBS colitis model group (TNBS + IP saline), receiving only IP saline vehicle treatment; APS low dose group (TNBS + L-APS), receiving APS 100 mg/kg; APS high dose group (TNBS + H-APS), receiving APS 200 mg/kg; and positive control group (TNBS + Dexm), receiving dexamethasone 0.3 mg/kg. The clinical features, macroscopic and microscopic scores were assessed. The expressions of TNF-α, IL-1β and NFATc4 were measured by real-time PCR and ELISA assays.ResultsCompared to normal control rats, TNBS + IP saline had significant weight loss, increased macroscopic and microscopic scores, higher disease activity index (DAI) up-regulation of TNF-α, IL-1β and NFATc4 mRNA expression and up-regulation of TNF-α and IL-1β protein expression. Compared to TNBS + IP saline, treatment with APS or dexamethasone significantly reduced DAI, partially but significantly prevented TNBS colitis-induced weight loss and improved both macroscopic and microscopic scores; high dose APS or dexamethasone significantly down-regulated TNF-α and IL-1β expressions (both mRNA and protein) and up-regulated NFATc4 mRNA and protein expression. The effect of high dose APS and dexamethasone is comparable.ConclusionsAPS significantly improved experimental TNBS-induced colitis in rats through regulation of TNF-α, IL-1β and NFATc4 expression.     

Effects of heat stress on some reproductive parameters of male cavie (Cavia porcellus) and mitigation strategies using guava (Psidium guajava) leaves essential oil

Climate changes, particularly the increase of temperature are among the main causes behind the decline of fertility in humans as well as animals. In this study, the effects of heat stress on some reproductive parameters of male cavies and mitigation strategies using guava leaves essential oil (GLEO) were studied. For this purpose, 40 male cavies aged 2.5–3 months and weighing between 348 and 446 g were divided into 4 groups of 10 animals each and subjected to the following temperatures: Ambient temperature (20–25 °C) for the control group, 35 °C for group 1, 45 °C for group 2 and 45 °C+100 µl GLEO/kg body weight, administered by gavage to animals for group 3. Exposure time of heat was 7 h per day for 60 days. Results reveal that the relative weights of testes, epididymis, vas deferens and seminal vesicles were hardly affected by the temperature levels considered (P>0.05). The mass and individual sperm motility was significantly lower (P<0.05) in cavies exposed to the temperature of 35 and 45 °C as compared with those which received GLEO and controls. The percentages of abnormal sperm and altered sperm DNA were higher in animals exposed to temperature of 35 and 45 °C as compared with the controls. The activity of superoxide dismutase significantly increased (P<0.05) in animals exposed to temperature of 45 °C and in those of 45 °C and orally treated with GLEO, compared with cavies exposed to temperature of 45 °C without receiving GLEO. The level of malondialdehyde was significantly increased (P<0.05) in animals exposed to temperature of 35 and 45 °C, whereas the level of nitric oxide was significantly lower (P<0.05) in exposed animals as compared with controls. It was concluded that the exposure of male cavies at 35 and 45 °C for 60 days induce heat stress that causes deterioration of sperm characteristics. These effects that can be mitigated by the administration of guava leaves essential oil.     

Postpartum resumption of ovarian cycling activity in first-calf suckled beef cows exposed to familiar or unfamiliar bulls

The objective of this experiment was to determine if the proportion of first-calf suckled beef cows that resumed ovulatory cycles and the interval to resumption of ovarian cycling activity differ after exposure to either “unfamiliar” bulls or cows on d 35 postpartum, after exposure to either “familiar” bulls or cows for the first 30–32 d after calving. Fifty Angus × Hereford cows were stratified by calving date, calf BW, and calf sex by d 3 postpartum, and assigned to be exposed to familiar epididectomized bulls (BEF; n = 25) or familiar mature ovariectomized (OVX) cows (CEF; n = 25). On d 35 after calving, 12 BEF cows were assigned to be exposed to unfamiliar bulls (BEU); likewise, 12 CEF cows were assigned to be exposed to unfamiliar OVX cows (CEU). Cows were in their treatments for either 95 d (BEF and CEF) or 60 d (BEU and CEU) during the experiment. Blood samples were collected every third d from the beginning to the end of the experiment. A rise in progesterone concentration of >0.5 ng/mL in consecutive samples was used as the criterion for resumption of ovulatory cycles. Exposing cows to bulls on d 5 after calving and then switching a subset of these cows to be exposed to unfamiliar bulls 30–32 d later did not (P > 0.10) alter: (1) the proportion of cows that resumed cycling activity; and (2) postpartum interval to resumption of ovarian cycling activity compared to cows exposed to familiar bulls. However, 32% more (P < 0.05) cows exposed to bulls (BEF and BEU) resumed cycling activity by approximately 14.8 d before cows that were exposed to OVX cows (CEF and CEU). We conclude that the familiarity of first-calf cows to either bulls or ovariectomized cows, did not affect the postpartum occurrence of cycling activity or the interval from calving to resumption of ovulatory cycles. However, bull exposure, whether familiar or unfamiliar, stimulates first-calf cows to resume ovulatory cycles sooner after calving than if they are not exposed to bulls.     

Granulocyte colony stimulating factor in myocardial infarction with low ejection fraction

Background: We investigated the safety and efficacy of GCSF therapy in a porcine model of ischemia–reperfusion with left ventricle ejection fraction of <45% using a clinically relevant dosing and timing regimen. Methods: MI was induced in pigs by a 90 min balloon occlusion of the left anterior descending coronary artery. Sixteen animals were randomized to either GCSF (IV bolus of 10 μg/kg at time of reperfusion, followed by SC injections of 5 μg/kg days 5–9 post-MI) or saline (control group). Inflammatory markers, bone marrow cell mobilization and LV function (echocardiography and pressure–volume measurements) were assessed at baseline, 1 and 6 weeks post-MI. Histopathology was performed 6 weeks post-MI. Results: GCSF therapy was associated with a significant increase in white blood cell counts. At week 6, GCSF therapy resulted in less deterioration of LVEF compared to control (38 ± 2% vs. 33 ± 2%, p < 0.02) and improved wall motion score index (p < 0.05). Histopathology revealed increased vascular density (p < 0.05) and a trend toward increased areas of viable myocardium compared to control (p = 0.058). Conclusion: GCSF therapy prevents further deterioration of LV function in a porcine model of MI with lower EF (<45%). These results support future clinical trials with GCSF in selected patients with larger MI.     

Effect of diagnostic cone-beam computed tomography protocols on image quality,patient dose,and lesion detection

ObjectiveTo evaluate the effect of cone-beam computed tomography (CBCT) image acquisition protocols on image quality, lesion detection, delineation, and patient dose.Methods100-patients and a CTDI phantom combined with an electron density phantom were examined using four different CBCT-image acquisition protocols during image-guided transarterial chemoembolization (TACE). Protocol-1 (time: 6 s, tube rotation: 360°), protocol-2 (5 s, 300°), protocol-3 (4 s, 240°) and protocol-4 (3 s, 180°) were used. The protocols were first investigated using a phantom. The protocols that were found to be clinically appropriate in terms of image quality and radiation dose were then assessed on patients. A higher radiation dose and/or a poor image quality were inappropriate for the patient imaging. Patient dose (patient-entrance dose and dose-area product), image quality (Hounsfield Unit, noise, signal-to-noise ratio and contrast-to-noise ratio), and lesion delineation (tumor-liver contrast) were assessed and compared using appropriate statistical tests. Lesion detectability, sensitivity, and predictive values were estimated for CBCT-image data using pre-treatment patient magnetic resonance imaging.ResultsThe estimated patient dose showed no statistical significance (p > 0.05) between protocols-2 and -3; the assessed image quality between these protocols manifested insignificant difference (p > 0.05). Two other phantom protocols were not considered for patient imaging due to significantly higher dose (protocols-1) and poor image quality (protocol-4). Lesion delineation and detection were insignificant (p > 0.05) between protocols-2 and -3. Lesion sensitivities generated were 81–89% (protocol-2) and 81–85% (protocol-3) for different lesion types.ConclusionData acquisition using protocols-2 and -3 provided good image quality, lesion detection and delineation with acceptable patient dose during CBCT-imaging mainly due to similar frame numbers acquired.     

Efecto positivo de la terapia de luz brillante sobre el estado de ánimo y la calidad del sueño en las personas mayores institucionalizadas

IntroductionBright light exposure during the day has a positive effect on health and its deficit can cause multiple physiological and cognitive disorders, including depression. The aim of this study was to evaluate the effect of bright light therapy (BLT) on the quality of sleep and mood emotional state; cognitive status, global deterioration and quality of life in institutionalized elderly.Material and methodsThis is a study with repeated measures design. Thirty-seven older people admitted to a nursing home. The study lasted 3 weeks. The first week, the reference values were established with the Oviedo Sleep Questionnaire, Yesavage Depression Scale, Mini-Mental, Global Scale of Impairment and European Quality of Life Questionnaire. During the second week, they were exposed to BLT (7,000-10,000 lx at eye level) between 9:30 a.m. and 11:00 a.m. During the third week, all the data were re-evaluated.ResultsAll variables improved significantly after the application of light therapy. Sleep (COS) pre-test 4.1 ± 1.49, post-test 4.9 ± 1.46, p: 0.01), mood (pre-test 3.65 ± 2.78, post-test 2.65 ± 2.9, p: 0.01), cognitive state (pre-test 22.72 ± 6.53, post-test 24 ± 5.92, p: 0.001), state of global deterioration (pre-test 3.10 ± 1.26, post-test 2.72 ± 5.92, p: 0.001) and health-related quality of life (pre-test 6.93 ± 1.86, post-test 7.82 ± 1.62, p: 0.001).ConclusionsSleep quality, mood, cognitive status, global deterioration status and quality of life significantly improved after the application of light bright therapy.     

Stratigraphie et chronologie du site de Gaolingpo dans le bassin de Bose,sud de la Chine

The Bose Paleolithic industry in the Bose Basin, Guangxi, South China is well known in the international scientific community for its bearing handaxes dated back to 803 ka. Seven terraces were developed in the basin and terrace 4 is the most important because handaxes and tektites were recovered from this terrace. Since the first site was discovered in 1973, additional sites of the Bose Paleolithic industry have been investigated and excavated, most of which are located on terrace 4. The previous studies concluded that there is only one phase within this industry and its age is 803 ka. However, before 2013, no attempt had been made to dig down to the basal gravels from the top of terrace 4 in archaeological excavations. Therefore, the stratigraphy and the layers from which the stone artifacts derive of terrace 4 are not clear. In 2013–2014, we conducted an excavation of 200 m² at the Gaolingpo site, which is one of the most important Paleolithic sites in the Bose Basin. We excavated to the basal gravel deposits from the top of this terrace, and a section of more than 7 meters thick deposit was exposed and clearly shows the stratigraphic layers of Pleistocene and Holocene deposits. Furthermore, features and about 800 stone artifacts including choppers, picks, scrapers, etc. were excavated from several stratigraphic layers, which are different in age and other aspects. Based on stratigraphy and the stone artifacts, three stages of Paleolithic cultural remains from the Gaolingpo site can be established. The first stage is in the age of at leat 803 ka. The second stage can be dated to 15 ka and the third stage to about 10 ka.     

Few-view CT reconstruction via a novel non-local means algorithm

PurposeNon-local means (NLM) based reconstruction method is a promising algorithm for few-view computed tomography (CT) reconstruction, but often suffers from over-smoothed image edges. To address this problem, an adaptive NLM reconstruction method based on rotational invariance (ART-RIANLM) is proposed.MethodsThe method consists of four steps: 1) Initializing parameters; 2) ART reconstruction using raw data; 3) Positivity constraint of the reconstructed image; 4) Image updating by RIANLM filtering. In RIANLM, two kinds of rotational invariance measures which are average gradient (AG) and region homogeneity (RH) are proposed to calculate the distance between two patches and a novel NLM filter is developed to avoid over-smoothed image. Moreover, the parameter h in RIANLM which controls the decay of the weights is adaptive to avoid over-smoothness, while it is constant in NLM during the whole reconstruction process. The proposed method is validated on two digital phantoms and real projection data.ResultsIn our experiments, the searching neighborhood size is set as 15 × 15 and the similarity window is set as 3 × 3. For the simulated case of Shepp-Logan phantom, ART-RIANLM produces higher SNR (36.23 dB > 24.00 dB) and lower MAE (0.0006 < 0.0024) reconstructed images than ART-NLM. The visual inspection demonstrated that the proposed method could suppress artifacts or noises more effectively and recover image edges better. The result of real data case is also consistent with the simulation result.ConclusionsA RIANLM based reconstruction method for few-view CT is presented. Compared to the traditional ART-NLM method, SNR and MAE from ART-RIANLM increases 51% and decreases 75%, respectively.