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We explore the effects of sex-related, value-expressive and functional image perceptions on satisfaction through a study of audience members at two theatres. Results suggest that satisfaction is higher for men when they perceive an elevated level of functional service quality and for women when they perceive that the theatre possesses pro-social values. Satisfaction overlap exists when either men or women perceive market or artistic values. Existing literature has suggested that women begin elaboration of message cues at a lower threshold than men; however, it appears that a zone exists where both sexes elaborate on some image attributes, while women further elaborate on communal attributes and men focus on agentic attributes. Contrary to prevailing evidence in the services management literature, no direct link surfaced between perceived quality of the core service and customer satisfaction. Post hoc tests for mediation indicate that tangible quality of the core service is important to both men and women, driving their engagement in elaboration of image attributes, but it is not important enough to directly stimulate satisfaction when other factors of the consumption experience are taken into account in complex encounters.

The success of radiotherapy critically depends on the imaging modality used for treatment planning and the level of integration of the available imaging information. The use of functional/metabolic imaging provides us much more than a tool to delineate better the boundary of a tumor target. Together with anatomical CT or MRI images, functional imaging affords valuable 3D structural plus 1D metabolic data for both tumor and sensitive structures, valuable for guiding us to design spatially non-uniform dose distributions to deliver high doses to where the tumor burdens are high and differentially spare the sensitive structures according to the functional importance distributions. The integration and utilization of the functional data in radiation therapy treatment planning become increasingly important to improve clinical cancer management. While it is straightforward to modify the radiation portals to accommodate any changes in treatment volume, new methods of dose optimization and medical decision-making must be developed to take full advantage of the metabolic information and IMRT. How to achieve biologically conformal doses, instead of the geometrically conformal dose distribution, presents a new challenge to radiation oncology discipline. Hopefully, with the efforts from multiple institutions, the new approach of imaging, planning and decision-making will be resolved. Ultimately, whether using deliberately inhomogeneous dose distributions obtained under the guidance of functional imaging such as MRSI can improve patient survival and reduce the side effects associated with radiation treatment should be established through extensive clinical trials.

Purpose: Computer tomography-based (CT-based) tumor-volume definition is time consuming and is subject to clinical interpretation. CT is not accessible for standardized algorithms for the purpose of treatment-volume planning. We have evaluated the accuracy of target-volume definition based on the positron emission tomography (PET) data from an integrated PET/CT system with 2-[{sup 18}F]fluoro-2-deoxy-D-glucose (FDG) for standardized target-volume delineation. Materials and Methods: Eleven patients with rectal cancer who were undergoing preoperative radiation therapy (RT) were studied. A standardized region-growing algorithm was tested to replace the CT-derived gross tumor volume by the PET-derived gross tumor volume (PET-GTV) or the biologic target volume (BTV). A software tool was developed to automatically delineate the appropriate tumor volume as defined by the FDG signal, the PET-GTV, and the planning target volume (PTV). The PET-derived volumes were compared with the target volumes from CT. Results: The BTV defined for appropriate GTV assessment was set at a single peak threshold of 40% of the signal of interest. Immediate treatment volume definition based on the choice of a single-tumor volume-derived PET-voxel resulted in a tumor volume that strongly correlated with the CT-derived GTV (r {sup 2} = 0.84; p < 0.01) and the volume as assessed on subsequent anatomic-pathologicmore » analysis (r {sup 2} = 0.77; p < 0.01). In providing sufficient extension margins from the CT-derived GTV and the PET-derived GTV, to PTV, respectively, the correlation of the CT-derived and PET-derived PTV was sufficiently accurate for PTV definition for external-beam therapy (r {sup 2} = 0.96; p < 0.01). Conclusion: Automated segmentation of the PET signal from rectal cancer may allow immediate and sufficiently accurate definition of a preliminary working PTV for preoperative RT. If required, correction for anatomic precision and geometric resolution may be applied in a second step. Computed PET-based target-volume definition could be useful for the definition of standardized simultaneous internal-boost volumes for intensity-modulated radiation therapy (IMRT) based on biologic target volumes.« less

Dynamic scan in PET has powerful capability to visualize various functionalities in a living tissue. But a dynamic scan requires long scan duration, and it is not practical for routine use. In this study, a shortened scan protocol is investigated in case of imaging of glucose metabolism in brain using /sup 18/F-FDG. In ordinary protocol of dynamic PET scan, more than 45 minutes is required. It is found that the first 30 minutes after FDG injection is enough to form a parametric image on glucose metabolism if a statistical clustering algorithm is incorporate to composed the parametric images.

An image segmentation tool designed for creation and manipulation of contours is presented. To deploy software which satisfies its intended purpose, one has to meet and engage users to expose the real requirements of the system. Thus, the main goal of this paper is to define a functional image of tool and to present the user interface of this image segmentation tool. In conclusion directions for the further work are described.

This chapter focuses on the disease specific brain atlas. Brain atlases have traditionally relied on static representations of anatomy. Many of the diseases that affect the human brain are progressive such as dementia and neoplastic tumors. Other disorders may be relapsing–remitting (e.g., multiple sclerosis) or may display a normal phenotype with an aberrant time course. The progression of a disease may also be modulated by therapy, ranging from drug treatment to surgery. This type of atlas is designed to reflect the unique anatomy and physiology of a particular clinical subpopulation. Disease-specific atlases are a type of probabilistic atlas specialized to represent a particular clinical group. The resulting atlases can identify patterns of altered structure or function and can guide algorithms for knowledge-based image analysis, automated image labeling, tissue classification, and functional image analysis. Atlas data on anatomic variability can also act as Bayesian prior information to guide algorithms for automated image registration and labeling. Rapid progress has been made in recent years by research groups developing standardized three-dimensional brain atlases. While few of these atlases aim to represent anatomy and function in disease, several commercially available atlases of pathology combine histologic data with illustrative metabolic or structural images.

Publisher Summary Autoimmunity refers to the existence in one's immune system of antigen receptors that can recognize one's own molecules as self-antigens. Autoimmunity describes a situation marked by T-cells, B-cells, or antibodies whose antigen combining sites can recognize self-molecules or parts of self-molecules. Autoimmunity thus denotes the immune recognition of self-antigens. There are two types of autoimmunities: natural or physiological autoimmunity and autoimmune disease. The classical clonal selection theory (CST) asserts that a healthy immune system must be purged of autoimmunity that cannot be physiological. Physiological autoimmunity focuses on a particular set of self-antigens forming a functional image of the self: the immunological homunculus. Physiological autoimmunity (T-cell and B-cell) seems to be directed mainly to three types of homuncular self-antigens: immune molecules, maintenance molecules, and some tissue antigens.

Purpose: To investigate clinical feasibility for functional‐image‐based target localization via onboard single photon emission computed tomography (onboard SPECT). Specifically, to understand lesion visibility and signal‐to‐noise ratio (SNR) of onboard SPECTimaging with the following simulated variables: lesion size, target‐to‐background radiotracer uptake, and scan time. Method and Materials: We simulated onboard SPECTimaging for a patient in treatment position who had received a diagnostic‐level dose of hypoxia radiotracer. The planning CT of a typical breast cancer patient with lung mets was segmented into bone, lung, and soft tissue. Lesions were simulated in the right lung that varied in diameter (0.5cm, 1cm, 1.5cm, 2cm, 3cm) and radiotracer uptake (lesion:lung:soft tissue — 6:1:3, 12:1:3, 18:1:3). Radiotracer concentration was 1.4μCi/g in aerobic soft tissue. Attenuation was modeled for 140 keV photons. Projection images were simulated for a gamma camera with parallel collimation, and Poisson noise was added to projections to simulate several scan times: 1min, 2min, 5min, 10min, 20min. Noisy projection images were reconstructed by OSEM (10 subsets, 5 iterations). Post‐filtered reconstructed images were then analyzed by plotting image profiles across each lesion and calculating SNR.Results: One minute scan time provided good visualization of a 2cm lesion with 12:1:3 uptake ratio. When scan time remained constant at 5 minutes, 2cm lesions were visible for each uptake ratio. In another simulation, a 1cm lesion (18:1:3) was clearly visible following 5 minutes of scan time. As expected, SNR generally improved with increased lesion size, scan time, and relative radiotracer uptake. Conclusion: Scan times on the order of a few minutes yield sufficient information to visualize lesions as small as 1cm in the lung. These results suggest that onboard SPECT may be effective for real‐time and functional‐image‐based target localization.

Registration of functional images (e.g., PET, SPECT) to anatomical images (e.g., MR, CT) of the brain is of importance, particularly when the functional images lack structural information. This chapter proposes a new method of registering such images, which involves adding structural information to functional image data. This additional structural information consists of a three-dimensional (3D) surface of the subject's face (Sobj) obtained using photogrammetric techniques. A similar 3D face surface (Sref) is extracted directly from anatomical image data and a constrained nonlinear search algorithm is then utilized to minimize the root mean square distance between the two face surfaces. The method was tested by registering MR and PET image sets of the head for six patients with brain tumors. These registrations were then compared to registrations determined by the Pelizzari-Chen surface-matching method. The two methods produced very similar results (mean difference 3.6 mm); the proposed method was judged by a blinded observer to be more accurate in four out of the six cases and worse in only one case. This technique is also useful in the registration of different functional images.

Myocardial perfusion scintigraphy with wall motion analysis is known to enhance accuracy in diagnosing ischemic heart disease. The purpose of this study is to determine the best method to evaluate regional wall motion in a gated planar perfusion study. Planar gated 99mTc tetrofosmin (GTF) study in two projections was performed after rest-exercise sequence SPECT studies (n = 29). To evaluate wall motion, cine-mode display, wall thickening, and inverted tetrofosmin studies including ventricular inner border tracing, segmental wall shortening and functional images were used. The results were compared with gated blood-pool (GBP) study in the same projections. In the GTF study, functional image identified asynergy significantly better than cinematic display. The best correlation between GTF and GBP studies was observed with functional images of phase and amplitude, with complete visual agreement seen in 145 of 168 (86%) segments. With quantitative analysis by means of regions of interest (n = 280), a good correlation was observed between GTF and GBP regarding regional amplitude (r = 0.78), regional phase (r = 0.84), average left ventricular phase (r = 0.91) and standard deviation of phase values (r = 0.90). The value for the count-based "ejection fraction" derived from inverted GTF showed insufficient correlation to that of the GBP study (r = 0.69). Functional imaging with myocardial perfusion imaging is a simple and effective means to evaluate ventricular asynergy. Similar diagnostic criteria to gated blood-pool imaging and comparable diagnostic accuracy are advantages of this approach.

Transcranial color coded real time sonography (TCCS, synonym: transcranial duplex — TDS) has evolved from transcranial Doppler sonography (TCD) and color duplex imaging (CDI) as a completely new diagnostic entity for CNS disease [1–4]. Vascular pathology, such as ischemic and hemorrhagic stroke [5–7], arteriosclerotic vascular degeneration [8], arteriovenous malformations and aneurysms [9, 10], as well as parenchymal abnormalities such as tumors [11–14], degenerative disorders [15] and monopolar depression [16] can be detected. Disturbances of CSF circulation can also be characterized and monitored [17]. The main advantage of TCCS lies in its applicability for use at the bedside, its real time imaging function, and its combination of morphological and functional image representation. A major disadvantage of TCCS was the attenuation of the ultrasound signal by the skull, which produced an inadequate result in about 20% of patients due to the insufficient signal-to-noise ratio. Ultrasound contrast agents capable of crossing the pulmonary circulation, such as Levovist, have changed this situation completely, improving the signal intensity recovered from within the skull by up to 30 dB [18]. This chapter summarizes experience with Levovist in this new and promising field of application.

Conclusions: This study demonstrated that the HPC may receive significant dose of IMRT for patients with T3 or T4 NPC. The HPC sparing IMRT planning was dosimetrically feasible, which could considerably decrease the dose delivered to the HPC with minimum adverse impact on the doses to the treatment targets and other OARs. Author Disclosure: G. Han: None. D. Liu: None. H. Gan: None. S. Li: None. Z. Wang: None. W. Tan: None. W. Zhen: None. D. Hu: None.

Rapid improvements in functional magnetic resonance neuroimaging technology have resulted in impressive advances in our understanding of structure/function relationships in the human brain. The application of this new technology to the understanding of human brain disease is currently limited by difficulties in extracting task-related signal change from signal intensity time series that have been contaminated by artifacts arising from various intrinsic and extrinsic sources. Effects induced by interscan head motion are a major source of these artifacts. The correction of these artifacts by registration of pairs of reconstructed images has been a focus of research for the past few years and there are now a number of effective means to compensate for this source of noise. This paper discusses issues concerning the prevention and correction of interscan head motion as well as other sources of error variation in fMRI time series.

Over the past 30 years, a wide variety of radiopharmaceuticals have been proposed for the scintigraphic detection of inflammatory and infectious disease. All radiopharmaceuticals yield a functional image of a process placed somewhere in the cascade of reactions in inflammation, this being the common pathway of response to tissue injury. This paper discusses relevant aspects of the biodistribution, in vivo kinetics and mechanisms of uptake of both clinically used and experimental radiopharmaceuticals that have been proposed for the scintigraphic detection of focal inflammation and infection.

During the past 2 decades, imaging techniques have come to play an indispensable role in practically all cardiovascular illnesses and not only in those conditions where these techniques have typically been used to determine the existence of a disease (for example, aortic or pericardial disease). The inclusion of echocardiographic findings in the diagnostic criteria of infectious endocarditis is only 1 simple example of the role that imaging techniques play in cardiovascular diagnosis. 1 The zenith of cardiovascular imaging during the last decade has been achieved due to 3 basic factors. First, technical improvements have increased the ability to anatomically determine diagnosis by means of using imaging techniques that have, on one hand, overcome old limitations 2 and, on the other, opened new horizons. 3,4 Secondly, the irruption of functional imaging has allowed the use of these noninvasive techniques to evaluate functional aspects of circulatory hemodynamics as well as physiology and cardiovascular metabolism. In the field of ischemic cardiopathy, the functional image provides irreplaceable information for clinical and basic investigations, but it has also become indispensable for guiding the therapeutic approach to treating patients with heart disease in daily practice. Finally, the clinical efficacy of decisions based on imaging techniques, in terms of improved prognosis and avoiding mortality/morbidity, has been clearly demonstrated. If during the 1980s research on cardiovascular diagnosis was dedicated to demonstrating the precision of measurements obtained with imaging, at present its clinical usefulness per se has been definitively established. Analysis of references in the Medline database shows that diagnosis by imaging, in any of its modalities, comprises approximately 20% to 25% of the scientific articles on the circulatory system. On the other hand, approximately 15% of the articles about diagnosis by means of imaging are dedicated to the cardiovascular system. These percentages have remained at the same level over the years, despite expected

To assess the effect of stimulus correlated motion on the appearance of functional magnetic resonance images, conventional visual and motor protocols were each performed by four normal volunteers and an image co-registration technique was used to retrospectively monitor subject motion. In three studies synthetic data sets were constructed from single baseline images using the positional information obtained from the co-registration procedure. Cumulative difference images were then created from both the synthetic and functional image sets. Stimulus correlated motion was detected in all eight studies and the synthetic cumulative difference images showed striking similarities to the equivalent functional images in each case.

Renal parenchymal transit time measurements are used in the diagnosis of obstructive nephropathy but parenchymal regions are usually drawn by hand with or without the aid of a functional image. This paper describes three computerized methods for derivation of parenchymal regions from a mean time functional image and compares them with the manual method by processing renogram data from 82 normal, 19 obstructed and 11 dilated nonobstructed kidneys using all four techniques. Receiver-operator characteristic analysis demonstrated the computer methods to be superior to manually drawn regions. The optimum computer method had a sensitivity of 95% and specificity 95% for distinguishing obstructed kidneys from dilated nonobstructed kidneys. The computer method could be readily incorporated into routine renogram analysis programs.

Trans-esophageal echocardiaography is a sensitive, minimally invasive, diagnostic tool which gives real time functional image of the aorta. It helps in the diagnosis of pathologies of aorta like atherosclerosis, aneurysm and aortic dissection.

Functional images in medicine, such as phosphorus magnetic resonance spectroscopic imaging (SI) images or perfusion studies in nuclear medicine (NM) using 99mTc-HMPAO, are low in resolution compared to x-ray CT or proton MR (anatomic) images. This paper describes an improved, rapid method for enhancing the accuracy and resolution of functional medical images. While both functional and anatomic images are often available for the organ under study, few attempts have been made to use the a priori information in the anatomic images to improve the poor resolution of the corresponding functional images. The proposed technique assumes that compartments can be identified in a high resolution anatomic image of the region under study, and each of these compartments is assumed to contain a spatially heterogeneous concentration of metabolite. The spatial variation of the metabolite is modelled by a series expansion. Application of the method is derived for both MR spectroscopic images, and scintigrams. Noise-free and noisy simulation studies of spectroscopic images are presented which show that the method is robust in the presence of noise, and also when the assumed model is mismatched to the function which describes the actual metabolite compartmental concentration.

The efficient operation of a clinical picture archiving and communication system (PACS) requires a fully functional image archive. The archive should not only be able to store and retrieve images reliably but should also work in concert with software that optimizes the flow of image-related information throughout the PACS. The authors devised a software suite that serves to improve the flow and content of information and the integrity of the data. The software was developed by translating the functions performed by a conventional film library. Types of transactions possible with this system include scheduling, canceling, rescheduling, and prestaging examinations; changing demographic information; merging patient information; and generating reports. The authors believe such a software suite is essential for a clinically useful PACS.

Vibration response imaging (VRI) is a new modality that reflects the distribution of vibration in the lung during the respiratory process. The VRI dynamic and functional image has been proved to be sensitive to changes in ventilator settings, including changes in mode of mechanical ventilation. In the present study, we assess the changes of the VRI image and quantification data as a function of positive end-expiratory pressure (PEEP) changes.

We report the usefulness of functional image of dynamic computed tomography as a technique for evaluating cerebral hemodynamics. Although the technique itself has been reported, the advance of computer technology has made it possible to obtain high-resolution functional images within only a few minutes. We conducted 70 examinations on 57 patients with cerebral ischemia and correlated the findings with clinical outcome. Those patients whose abnormalities were detected on all corrected mean transit time, time to peak, and peak value images developed massive cortical infarcts. On the other hand, patients with abnormalities detected only on the corrected mean transit time image had only partial low-density lesions on follow-up computed tomograms. Patients with abnormalities detected only on the time to peak image suffered repeated transient ischemic attacks, but follow-up computed tomograms showed no low-density lesion in most cases. Single-photon emission computed tomography with N-isopropyl-p-(123I)iodoamphetamine performed at the time of functional image of dynamic computed tomography showed a high concordance of the findings in many cases, especially those with hyperacute-stage cerebral ischemia, in which the concordance rate was 90.5% (19 of 21). Comparing images constructed from different parameters, functional image of dynamic computed tomography can delineate other than hemodynamic factors, such as extent of the vascular bed or the degree of collateral circulation. Thus, functional image of dynamic computed tomography is a potentially important and useful technique for the further analysis of cerebral hemodynamics.

Airflow into a mechanically ventilated patient is easily measured in the inspiratory limb of the ventilator. Regional airflow inside the lungs, up to this point, is a black box. Vibration response imaging (VRI) is a novel technology that measures vibration energy from the lungs to create a real-time structural and functional image of regional vibration during respiration. Sophisticated surface skin sensors are placed on the subject's back to record, analyze and display vibrations noninvasively. Our goal was to assess the correlation of vibration measured at the chest wall with airflow into the lungs.

Vibration response imaging (VRI) is a novel technology that measures vibration energy generated from airflow to create a real-time structural and functional image of the respiration process. Since this new imaging technique can be performed quickly and non-invasively at the bedside, it offers potential as a real time noninvasive method of adjusting ventilatory therapy.

Despite considerable progress in the treatment of malignant disease, early detection still offers the best chance of a favourable prognosis. For patients with cancer, the anatomical identification of lesions by Computed Tomography (CT) has been used extensively to provide a differential diagnosis, following the onset of clinical symptoms. However, by the time abnormal tissue has grown sufficiently to appear positive on CT, the disease may well have progressed to a stage where successful treatment is, at best, difficult and at worst, impossible. The key is to identify a concentration of cancer cells at the earliest possible stage in the disease development. In the past few years, Positron Emission Tomography (PET) with 18F-fluoro-deoxyglucose (FDG) has become increasingly widely used to both diagnose and stage malignant disease. Fusion imaging that combines CT and PET obviously offers the best of both worlds: functional abnormalities can be accurately localized with CT and the functional status of anatomical abnormalities can be assessed with PET. While software fusion techniques provide accurately-aligned images of the brain, for the remainder of the body, patient positioning and involuntary internal organ movement present a difficult challenge. The recent introduction of hardware fusion using dual-modality combined PET/CT scanners has resolved many of the difficulties inherent to the software approach. With the combined scanner, the patient remains on the same bed for both CT and PET scans and a simple axial translation of the couch transports the patient from the CT to the PET imaging fields. A single scan session thus provides accurately aligned anatomical and functional image sets. Even though combined PET/CT scanners have been in production for only four years, the technology is undergoing rapid evolution. For PET, the introduction of new scintillator materials, detector concepts and electronics is resulting in performance improvements in count rate, spatial resolution and signal-to-noise. At the same time, the increasing number of detector rows and reduction in rotation time are transforming whole-body CT performance. The combination of high performance CT with high performance PET is a powerful imaging platform for the diagnosis, staging and therapy monitoring of malignant disease. Over 90% of PET sales are now PET/CT with the prediction that PET-only scanners could be replaced entirely by PET/CT in the future. It is also anticipated that there will be a demand for a mid-range design that offers less performance at less cost. Since the performance of the PET components is the limitation on the overall imaging time, institutions requiring high throughput and large patient volumes will always demand the highest PET performance. Nevertheless, a 4 or 8-slice CT scanner should be adequate for oncology, while a 16 or 64-slice CT will be more appropriate for cardiac applications. As the current PET/CT technology becomes more widespread, appropriate designs implementing this concept will doubtless emerge in the future. Educational Objectives: 1. Summarize the rationale for combined PET/CT 2. Review recent advances in PET/CT designs 3. Discuss the future potential for the technology

SummaryThis paper presents an alternative method of demarcating regions of in terest over the myocardium after ad ministration of 123I-heptadecanoic acid to patients with coronary artery disea se. In a matrix of 32 × 32 pixels the elimination rates of the radioactivity, which are not corrected for back ground activity, are visualized per pixel in a functional image. The func tional image showed areas in the myocardium with high values of uncorrected elimination rates. These areas corresponded with the tracer defects on the scintigram. Corrected elimination rates obtained from re gions of interest of functional images were comparable with those of scinti grams. Thus based on functional im ages of uncorrected elimination rates a reliable, objective determination of regions of interest over normal and abnormal myocardium can be made.

Dynamic hepatobiliary image data were analyzed by the mathematical deconvolution to derive the transfer function (TF) which represents the impulse response function of the liver following direct bolus injection of a tracer into the liver. Biliary flow was evaluated by TF in patients with previous hepatobiliary surgery to detect abnormal flow causing problems such as cholangitis. Serial image data were collected for 60 min after intravenous injection of 37-75 MBq (1-2 mCi) of 99mTc-N-pyridoxyl-5-methyltryptophan (99mTc-PMT). TF was obtained by the matrix algorithm, using regional hepatogram as output and time-activity curve over the heart as input function. Minimum, mean and maximum transit time (Max. TT) were determined from TF. The functional image for each of the transit times was constructed by displaying the distribution of the values for matrix elements with a color scale. In this study, a critical Max. TT of 60 min was used to detect abnormal biliary flow. Of 30 cases, 9 positive cases were discriminated from 21 negative cases on the basis of the finding of presence or absence of areas with Max. TT of more than 60 min anywhere in the liver. Bowel activity overlapping the liver was excluded in the judgment. The validity of this method was evaluated in comparison with the clinical courses after surgery with (8 cases) or without (22 cases) problems. The results were sensitivity of 88%, specificity of 91%, accuracy of 90% and positive predictive value of 78%.(ABSTRACT TRUNCATED AT 250 WORDS)

A fully automated chest parsing algorithm has been developed to delineate eight major regions of the upper body after a bolus injection of radiopharmaceutical. The algorithm uses the time-to-max functional image and depends on only one size parameter. Regions are selected by a 4-connected region growing procedure which is table driven from values extablished by an analysis of moments of the time-to-max image and region separation by iterative cluster optimization with a Fisher's linear discriminant. On a set of 88 scans (59 cardiac outputs with 11 in heart failure and 29 pediatric shunt analyses), the chest parsings algorithm gave a satisfactory choice for the lungs, 89%; the right heart, 93%; and the left heart, 76%.

Anatomic localization in functional (such as PET) imaging often requires a structural (such as CT or NMRI) study of the brain in the same plane. Some neuropsychiatric conditions make it difficult for a patient to hold his/her head immobile even when a rigid head holder is used. We studied the effect of tilt of the anatomic reference image, in this instance CT, relative to the functional image, here PET, on the quantification of receptor ligand concentration in anatomically defined regions of the brain.

Four types of liver functional images were obtained by calculating for each point on an image matrix the local uptake rate, the local uptake transit time, the point's own maximum and the time necessary to attain the maximum. The study was based on 52 cases: 21 controls and 31 cases of hepatic disease. The controls showed a homogeneous spread of colloidal substance on the images of local uptake rate and local transit time, despite variations in liver tissue thickness. In the cases of parenchymal lesions revealed by deficient uptake on standard images, local variations of uptake rate were almost always shown even in instances where the standard images showed minimal variation. This technique therefore would seem to bring additional diagnostic assistance by permitting a better appreciation of liver morphology and function and the processing time required (approx. 1.5 min.) does not necessitate an increase in overall examination time.

Article, 信州医学雑誌 32(1): 25-42(1984)

A method is described for measuring relative left atrial volume changes with gated radionuclide angiography, using an approximate computer-generated functional image to locate the atrial region of interest. M mode echocardiographic measurements of left atrial and left ventricular distances from the chest wall allowed calculation of a correction factor for the differential attenuation of atrial and ventricular photons. Background-corrected left atrial time-activity curves obtained from normal subjects exhibited excellent temporal resolution and were used to identify and quantitate the reservoir and contractile phases of left atrial volume change. In 20 normal subjects, the mean (+/- standard deviation) value for left atrial fractional emptying was 0.39 +/- 0.07. Expressed as fractions of the left ventricular stroke volume, mean values of the specific phases of atrial volume change were (1) reservoir volume 0.25 +/- 0.09, (2) contractile volume 0.29 +/- 0.10, and (3) conduit volume 0.46 +/- 0.12.

Ammonia has been known to be an inducing agent of hepatic coma associated with liver cirrhosis. In order to establish a non-invasive method of investigating the portal circulation and the metabolism of ammonia at liver the following studies were performed, by using cyclotron produced 13N-labeled ammonia and delayed line-camera interphased with on-line computer system. 1) Animal experiment. Dynamic scintigraphy of thoraco-abdominal region of a rabbit after intrasigmoidal as well as intravenous administration of 13N-ammonia were performed. 2) Theoretical consideration on the functional image of liver: According to the results of the animal experiments, a model of ammonia metabolism having the minimal complexity necessary to represent data in the case of intrasigmoidal administration was proposed. Starting from the solution to the differential equation describing the model, relevant parameters characterizing the dynamic curve of liver were duded.

SCANNING IS widely accepted as a means of detecting abnormalities in the regional function of certain organs. For example, labeled particles such as macroaggregates of albumin can be used to portray the regional perfusion of the lung. In a related manner, the distribution of colloidal particles reveals the reticuloendo-thelial function within the body, and the thyroid scan indicates the distribution of the function of iodide uptake. In these cases, the amount of radioisotope accumulated by a given region is an index of that region's function. In a sense, the scanning image may be thought of as a map of regional function. If we express this relationship between function and the amount of radioactivity in mathematical terms, it may be written as : F= (q).......(1) where F is regional function and q is the amount of radioisotope accumulated in the region. At times, regional function can be better measured by the rate of change. For example, regional blood flow measured by 133Xe washout from a region may be e...

It is well known that the parietal cells show a functional movement and a circle of the functional image following the administration of food. NAKAMURA (1952) has reported that the functional movement and the functional circle are characteristic according to the nature of the diet. In this paper it is noticed that the circle of the functional image of the parietal cells are also variable according to the temperature of the diet even with the same kind of food.Food of the same kind, kept at 5°C, 37°C or 55°C was given. In the case of 5°C, the parietal cells first show the produtive image of the secretory substance (30min. after the administration), then its discharging image (after 60min.), but afterwards the functional images become less active. In the case of 37°C, both discharge and production are marked from an early period (after 30min.), then they reach the maximum (after 60min.), but afterwards the function fell off as in the former case. And in the case of 55°C, discharge and production can be recognized soon after the administration (after 30min.) and they reach the maximum (after 60min.). Then the functional images of discharge and production decrease to its minimum (after 2hrs.), but they show again the maximum image 3hrs. after the administration.Here, it is very interesting to note that the functional images of the parietal cells are comparable with the ones of the peptic cells which were reported in a former paper. In the peptic and parietal cells the secretory substances are produced practically at the same time, but are always discharged somewhat earlier by the parietal cells.Broadly speaking the peptic and the parietal cells go hand in hand, and the characteristic fuuctional image of the peptic cells according to the difference of the food temperature reported in the 1st paper can be applied to the parietal cells.Therefore the author believes that the secretion of gastric juice itself will be characteristic according to the temperature of the food and is convinced that the suggestion which the author made in the forgoing study (I) i. e. as for the study of the digestion in the stomach, not only the nature of food but also its temperature must be taken into consideration, is not untrue.