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We propose and experimentally demonstrate single-scan vectorial frequency-resolved optical gating (FROG) which characterizes the amplitude, phase and polarization of ultrashort laser pulses using a single measured spectrogram. It is carried out by rotating the polarization of the incoming pulse (using a half-wavelength waveplate), in parallel to scanning the delay between the pulse and its replica in an otherwise ordinary FROG apparatus. A ptychography-based phase retrieval algorithm extracts the full pulse information from the recorded spectrogram. We numerically show that this method is reliable and use it to experimentally reconstruct a pulse with intricate time-dependent polarization. We also show that this method can be used to remove time-reversal ambiguity of second harmonic generation FROG.

Macrophages are excellent imaging targets for detecting atherosclerotic plaques as they are involved in all the developmental stages of atherosclerosis. However, no imaging technique is currently capable of visualizing macrophages inside blood vessel walls. The current study develops an intravascular ultrasonic-photoacoustic (IVUP) imaging system combined with indocyanine green (ICG) as a contrast agent to provide morphological and compositional information about the targeted samples. Both tissue-mimicking vessel phantoms and atherosclerotic plaque-mimicking porcine arterial tissues are used to demonstrate the feasibility of mapping macrophages labeled with ICG by endoscopically applying the proposed hybrid technique. A delay pulse triggering technique is able to sequentially acquire photoacoustic (PA) and ultrasound (US) signals from a single scan without using any external devices. The acquired PA and US signals are used to reconstruct 2D cross-sectional and 3D volumetric images of the entire tissue with the ICG-loaded macrophages injected. Due to high imaging contrast and sensitivity, the IVUP imaging vividly reveals structural information and detects the spatial distribution of the ICG-labeled macrophages inside the samples. ICG-assisted IVUP imaging can be a feasible imaging modality for the endoscopic detection of atherosclerotic plaques.

High Utility Itemset Mining (HUIM) alludes to the identification of itemsets of high utility in the value-based database UP-Growth algorithm is a standout amongst the best algorithms for overcome the challenge of candidate generation and scan database reputedly of previous algorithms. However, it needs scan database twice to actualize the UP tree. Regarding of the updating existing data with new information, UP-growth needs for twofold scanning of new information and existing information. The fundamental motivation behind this work is to build up another algorithm, Single-Scan Utility Pattern Tree (SSUP-tree), for mining high utility itemsets from transaction database through only single-scan of database. In our algorithm, the details of high-utility itemsets is preserved in a particular data structure of the SSUP-Tree after a single-scan of database. Consequently, it can retrieve the identical UP-tree with a fixed minimum utility threshold. The proposed algorithm required to scan the new data only to update SSUP-tree. In this regard, in order to estimate the execution of the proposed algorithm, the SSUP-tree algorithm has been implemented on synthetic and real datasets. The results of this study revealed that SSUP-tree shows a significant enhancement in the execution in terms of runtime since it keeps the huge databases details in a compact format and it avoids repetition of database scanning.

The authors propose a combined scatter reduction and correction method to improve image quality in cone beam computed tomography (CBCT). The scatter kernel superposition (SKS) method has been used occasionally in previous studies. However, this method differs in that a scatter detecting blocker (SDB) was used between the X-ray source and the tested object to model the self-adaptive scatter kernel. This study first evaluates the scatter kernel parameters using the SDB, and then isolates the scatter distribution based on the SKS. The quality of image can be improved by removing the scatter distribution. The results show that the method can effectively reduce the scatter artifacts, and increase the image quality. Our approach increases the image contrast and reduces the magnitude of cupping. The accuracy of the SKS technique can be significantly improved in our method by using a self-adaptive scatter kernel. This method is computationally efficient, easy to implement, and provides scatter correction using a single scan acquisition.

We are developing methods for imaging multiple PET tracers in a single scan with staggered injections, where imaging measures for each tracer are separated and recovered using differences in tracer kinetics and radioactive decay. In this work, signal separation performance for rapid dual-tracer (62)Cu-PTSM (blood flow) + (62)Cu-ATSM (hypoxia) tumor imaging was evaluated in a large animal model. Four dogs with pre-existing tumors received a series of dynamic PET scans with (62)Cu-PTSM and (62)Cu-ATSM, permitting evaluation of a rapid dual-tracer protocol designed by previous simulation work. Several imaging measures were computed from the dual-tracer data and compared with those from separate, single-tracer imaging. Static imaging measures (e.g. SUV) for each tracer were accurately recovered from dual-tracer data. The wash-in (k(1)) and wash-out (k(2)) rate parameters for both tracers were likewise well recovered (r = 0.87-0.99), but k(3) was not accurately recovered for PTSM (r = 0.19) and moderately well recovered for ATSM (r = 0.70). Some degree of bias was noted, however, which may potentially be overcome through further refinement of the signal separation algorithms. This work demonstrates that complementary information regarding tumor blood flow and hypoxia can be acquired by a single dual-tracer PET scan, and also that the signal separation procedure works effectively for real physiologic data with realistic levels of kinetic model mismatch. Rapid multi-tracer PET has the potential to improve tumor assessment for image-guide therapy and monitoring, and further investigation with these and other tracers is warranted.

Quantification of myocardial blood flows at rest and stress using 13N-ammonia PET is an established method; however, current techniques require a waiting period of about one hour between scans. The objective of this study was to test a rapid dual-injection single-scan approach, where 13N-ammonia injections are administered 10 minutes apart during rest and adenosine stress. Dynamic PET data were acquired in six human subjects using imaging protocols that provided separate single-injection scans as gold standards. Rest and stress data were combined to emulate rapid dual-injection data so that the underlying activity from each injection was known exactly. Regional blood flow estimates were computed from the dual-injection data using two methods: background subtraction and combined modeling. The rapid dual-injection approach provided blood flow estimates very similar to the conventional single-injection standards. Rest blood flow estimates were affected very little by the dual-injection approach, and stress estimates correlated strongly with separate single-injection values (r = 0.998; mean absolute difference = 0.06 ml/min/g). An actual rapid dual-injection scan was successfully acquired in one subject and further demonstrates feasibility of the method. This study with a limited dataset demonstrates that blood flow quantification can be obtained in only 20 minutes by the rapid dual-injection approach with accuracy similar to that of conventional separate rest and stress scans. The rapid dual-injection approach merits further development and additional evaluation for potential clinical use.

In this paper we will report the preliminary study of people's subjective feelings on stroking surfaces of different materials and the measured properties of these surfaces, in order to understand exactly what properties matter and to what extent the different factors weight the human perception. Ten specimens with materials ranging from natural wood, leather to engineered plastics and metal were selected for this study. These specimens were first tested by a group of untrained people for describing their subjective feel sensation in terms of smoothrough, soft-hard, slippery-grippy, warm-cold and overall judgement of like and dislike for the sample being touched. Then the same specimens were measured for their surface properties by various techniques. In particular, the multi-function measurement has been carried out on each of specimens by a novel tribological probe microscope (TPM). The TPM is capable of measuring four functions in a single scan to provide area mappings of topography, friction, Young's modulus and hardness. As the TPM mapping is based on a point-by-point scanning so values of the four measured functions are linked in space and in time, therefore cross correlation between functions can be established. Although the TPM measured area is small compared to fingertip, the results show that the perception is influenced by nano- and microscale structure of surfaces.

Dose profiles are presented resulting from computed tomography (CT). The profiles are positioned at the central axis, 1 cm away from the outer surface of the phantom, for single and multiple scans. A Hitachi W-1000 scanner is used with a thermoluminescent dosimeter (TLD), and standard dosimetry head and trunk phantoms. Regression equations are found linking the dose resulting from scattered radiation associated with a single scan to the distance from the scanning centre. The impact on the CT dose index value (CTDI) for varying integrating lengths is analysed. Some problems associated with CT dose measurement are noted, which may assist in the practical application of IBSS (International Basic Standard of Radiation Protection and Safety of Radiation Sources) guide levels.

Films of silicon phthalocyanine dichloride deposited from solution onto a chemically prepared hydrogen-passivated Si(111) surface were manipulated with the scanning tunnelling microscope (STM) in air. We find that nanometre-scale square and trench patterns can be created in the film by the STM tip through repeated scans under normal imaging conditions ( V, I = 0.35 nA) or by a single scan using a high tunnelling current (10 nA). Spectroscopic measurements of the film show that the film is chemically unchanged by the machining process. The film cannot be machined after exposure to air for a period of days, suggesting that some form of hydrolysis of occurs.

We describe a novel method of single-scan Kelvin probe force microscopy, operating simultaneously with amplitude-modulation distance control in ambient air. A separate Kelvin probe feedback control loop compensates for potential differences between tip and sample by minimizing electrostatic forces. As a result, electrostatically induced height errors in topography are automatically cancelled. To prevent crosstalk from topography or errors in distance control, the Kelvin probe feedback employs phase information resulting from a combination of mechanical and electrical excitation of the cantilever at its second flexural eigenmode. The feedback for amplitude-modulation distance control operates as usual close to the first eigenfrequency.

The problems associated with beam hardening in X-ray transmission computed tomography (CT) have been described by Brooks and DiChiro (1976). These include the introduction of non-linear artefacts in CT images with corresponding errors of as high as 10% in CT measurements of the linear attenuation coefficient, thus severely limiting the use of CT in quantitative applications. Many of the techniques proposed to eliminate or reduce this artefact have been summarised by Stonestrom et al. (1981). A practical technique for correcting this artefact which has been implemented on an EMI CT5005 whole-body scanner is presented. It is proposed that by taking dual-energy measurements and obtaining two polyenergetic ray sums (p1 and p2) it is possible to obtain a better estimate of the monoenergetic ray sum m than can be obtained from a single polyenergetic measurement of the ray sum p (Herman 1979). An expression of the form given can be used to estimate m. By using dual-energy data collected in a single scan the correction can be carried out quickly with no additional patient dose.

The shutter mechanism and film holder from an inexpensive Polaroid camera can be arranged around a rotating mirror to give high-speed, high-resolution pictures of self-illuminating events. Moreover, the shutter, which closes after one scan, prevents multiple exposure and thus enables one to study events which continue to emit light after the period of interest. By use of a simple Variac to control the speed of a high-speed motor, the time resolution on the film can be easily changed from 1 ps mm-l to 0.3 ms "-1. For scan speeds slower than this, it is advantageous to replace the high-speed motor with a low speed one.