Medical imaging modalities to image either anatomical structure or functional processes have developed along somewhat independent paths. Functional images with single photon emission computed tomography (SPECT) and positron emission tomography (PET) are playing an increasingly important role in the diagnosis and staging of malignant disease, image-guided therapy planning, and treatment monitoring. SPECT and PET complement the more conventional anatomic imaging modalities of computed tomography (CT) and magnetic resonance (MR) imaging. When the functional imaging modality was combined with the anatomic imaging modality, the multimodality can help both identify and localize functional abnormalities. Combining PET with a high-resolution anatomical imaging modality such as CT can resolve the localization issue as long as the images from the two modalities are accurately coregistered. Software-based registration techniques have difficulty accounting for differences in patient positioning and involuntary movement of internal organs, often necessitating labor-intensive nonlinear mapping that may not converge to a satisfactory result. These challenges have recently been addressed by the introduction of the combined PET/CT scanner and SPECT/CT scanner, a hardware-oriented approach to image fusion. Combined PET/CT and SPECT/CT devices are playing an increasingly important role in the diagnosis and staging of human disease. The paper will review the development of multimodality instrumentations for clinical use from conception to present-day technology and the application software.
Accounting ; Complement System Proteins ; Dyskinesias ; Fertilization ; Humans ; Magnetic Resonance Spectroscopy ; Patient Positioning ; Positron-Emission Tomography ; Tomography, Emission-Computed, Single-Photon

By expanding health insurance, customers will carry a smaller burden of medical costs. As a result, the number of visits to a physician increase and this result in the improvement of medical accessibility. But medical care utilization may be changed not only by insurance status but also by socio-demographic factor, economic status and other factors. The question thus remains, at which level of accessibility and what price of medical care service in health insurance will the customer and the medical care service be satisfied. The price of medical care service is comprised of the customer's out-of-pocket money and the costs not covered by health insurance. If the price of medical care services in health insurance are appropriate, medical care utilization should not differ because of the difference in income status or the acuteness of illness. But If the price is not adequate, low income groups will receive relatively low medical care utilization, particularly in the case of chronic disease. The purpose of this study is to evaluate the differences in medical care utilization among the various income groups and those with varying acuteness of illness. The major hypotheses to test in this study are : (I) whether there are differences in medical care utilization among different income groups exist, (II) whether differences in medical care utilization among different income groups exist with the hospital type. (III) whether differences in medical care utilization among different income groups exist with the acuteness of illness and with age. The data was collected from the JongRo District Health Insurance Society in Seoul. A total of 118,336 persons were selected as the final sample for this study. The major findings of this study were as follows ; 1. The volume of ambulatory utilization among users was statistically significant by income level. 2. Among different income groups, the volume of ambulatory utilization was statistically significant by the acuteness of illness. 3. Higher income groups with chronic diseases had a greater volume of ambulatory utilization than other groups.
Chronic Disease ; Humans ; Insurance Coverage ; Insurance, Health* ; Seoul

PURPOSE: We evaluated the feasibility of extracting pure left ventricular blood pool and myocardial time-activity curves (TACs) and of generating factor images from human dynamic N-13 ammonia PET using factor analysis. The myocardial blood flow (MBF) estimates obtained with factor analysis were compared with those obtained with the user drawn region-of-interest (ROI) method. MATERIALS AND METHODS: Stress and rest N-13 ammonia cardiac PET imaging was acquired for 23 min in 5 patients with coronary artery disease using GE Advance tomograph. Factor analysis generated physiological TACs and factor images using the normalized TACs from each dixel. Four steps were involved in this algorithm: (a) data preprocessing; (b) principal component analysis; (c) oblique rotation with positivity constraints; (d) factor image computation. Area under curves and MBF estimated using the two compartment N-13 ammonia model were used to validate the accuracy of the factor analysis generated physiological TACs. The MBF estimated by factor analysis was compared to the values estimated by using the ROI method. RESULTS: MBF values obtained by factor analysis were linearly correlated with MBF obtained by the ROI method (slope=0.84, r=0.91). Left ventricular blood pool TACs obtained by the two methods agreed well (Area under curve ratio: 1.02 (0~1 min), 0.98 (0~2 min), 0.86 (1~2 min)). CONCLUSION:: The RESULTS of this study demonstrates that MBF can be measured accurately and noninvasively with dynamic N-13 ammonia PET imaging and factor analysis. This method is simple and accurate, and can measure MBF without blood sampling, ROI definition or spillover correction. KW: N-13 ammonia, PET, Myocardial blood flow, Factor analysis
Ammonia* ; Area Under Curve ; Coronary Artery Disease ; Factor Analysis, Statistical* ; Humans ; Principal Component Analysis

PURPOSE: We characterized the signals obtained from the components of a small gamma camera using NaI(Tl)-position sensitive photomultiplier tube (PSPMT) and optimized the parameters employed in the modules of the system. MATERIALS AND METHODS: The small gamma camera system consists of a NaI(Tl) crystal (60x60x6 mm3) coupled with a Hamamatsu R3941 PSPMT, a resister chain circuit, preamplifiers, nuclear instrument modules (NIMs), an analog to digital converter and a personal computer for control and display. The PSPMT was read out using a resistive charge division circuit which multiplexes the 34 cross wire anode channels into 4 signals (X+, X-, Y+, Y-). Those signals were individually amplified by four preamplifiers and then, shaped and amplified by amplifiers. The signals were discriminated and digitized via triggering signal and used to localize the position of an event by applying the Anger logic. The gamma camera control and image display was performed by a program implemented using a graphic software. RESULTS: The characteristics of signal and the parameters employed in each module of the system were presented. The intrinsic sensitivity of the system was approximately 8x103 counts/sec/microcurie. The intrinsic energy resolution of the system was 18% FWHM at 140 keV. The spatial resolution obtained using a line-slit mask and 99mTc point source were, respectively, 2.2 and 2.3 mm FWHM in X and Y directions. Breast phantom containing 2~7 mm diameter spheres was successfully imaged with a parallel hole collimator. The image displayed accurate size and activity distribution over the imaging field of view. CONCLUSION: We proposed a simple method for development of a small gamma camera and presented the characteristics of the signals from the system and the optimized parameters used in the modules of the small gamma camera.
Anger ; Breast ; Electrodes ; Gamma Cameras* ; Logic ; Masks ; Microcomputers

Pulsating exophthalmos, bruit, episcleral venous distention, conjunctival and (eye)lid edema, ophthalmoplegia, and ocular pain have long been regarded as the classic symptoms and signs of idiopathic dural carotid cavernous sinus fistula(CCF). We experienced a 39-year-old woman who presented with headache and cyclovertical diplopia. On neurologic examination, we found isolated left trochlear nerve palsy only. The past medical history was not remarkable. Intracranial magnetic resonance angiography revealed abnormal signals around the carotid siphon on both sides. Conventional angiography confirmed bilateral dural CCFs, leaking predominantly from the left side. Diplopia and headache had improved spontaneously over 3 weeks after the onset. Occasionally, isolated oculomotor or abducens nerve palsy has been reported as the sole clinical finding of symptomatic dural CCF. But isolated trochlear nerve palsy with dural CCF is extremely rare. Although the exact mechanisms of isolated trochlear nerve palsy by dural CCF is unclear, various mechanisms have been proposed, including compression of trochlear nerve by venous congestion or direct shunted flow in cavernous sinus, vascular steel phenomenon, and venous thrombosis.
Abducens Nerve Diseases ; Adult ; Angiography ; Carotid-Cavernous Sinus Fistula* ; Cavernous Sinus ; Diplopia ; Edema ; Exophthalmos ; Female ; Headache ; Humans ; Hyperemia ; Magnetic Resonance Angiography ; Neurologic Examination ; Ophthalmoplegia ; Steel ; Trochlear Nerve Diseases* ; Trochlear Nerve* ; Venous Thrombosis

The goals of developments in nuclear medicine instrumentation are to offer a higher-quality image and to aid diagnosis, prognosis assessment or treatment planning and monitoring. It is necessary for physicists and engineers to improve or design new instrumentation and technique, and to implement, validate, and apply these new approaches in the practice of nuclear medicine. The researches in physical properties of detectors and crystal materials and advance in image analysis technology have improved quantitative and diagnostic accuracy of nuclear medicine images. This review article presents recent developments in nuclear medicine instrumentation, including scatter and attenuation correction, new detector technology, tomographic image reconstruction methods, 511 keV imaging, dual modality imaging device, small gamma camera, PET developments, image display and analysis methods.
Diagnosis ; Gamma Cameras ; Image Processing, Computer-Assisted ; Nuclear Medicine* ; Prognosis

BACKGROUND: Pulmonary complications following bonemarrow transplantation(BMT) are common and associated with a high mortality rate, We investigated the yield, safety, and impact of fiberoptic bronchoscopy(FOB) for diagnosis of postBMT pneumoniae. METHODS: From May 1997 to April 2000, 56 FOBs were performed in 52 post BMT patients for clinical pneumoniae. BMT patients with repiratory symptoms and/or pulmonary infiltrates had a thoracic HRCT(high resolution computed tomography) and bronchoscopic examination including BAL(bronchoalveolar lavage), TBLB(transbronchial lung biopsy), PSB(protected specimen brush). RESULTS: The characteristics of the subjects were as follows:37 males, 15 females, mean age of 31.3 years(17-45), 35 sibling donor allogenic BMTs, 15 nonrelated donor allogenic BMTs, and 2 autologous BMTs. Fiftynine percent of FOBs (33 FOBs, 31 patients) were diagnostic. Isolated pathogens included the following:12 cytomegalovirus(CMV) (21.4%), 7 pneumocystis carinii(PC) (12.5%), 11 CMV with PC (19.6%), 2 Mycobacaterium tuberculosis (3.6%), and 1 streptococcus (1.8%). Most of the radiographic findings were diffuse interstitial lesions. CMV pneumoniae had mainly diffuse interstitial nodular lesion, and PC pneumoniae had diffuse, interstitial ground glass opacity(GGO). When CMV was accompanied by PC, a combined pattern of nodular and GGO was present. Of the 56 cases(23.2%), 13 died of CMV pneumoniae(n=2), PCP(n=2), mixed infection with CMV and PC(n=3), underlying GVHD(n=1), underlying leukemia progression(n=1), or respiratory failure of unknown origin(n=4). There was no major complication by bronchoscopy. Only 3 cases developed minor bleedig and 1 episode temporary hypoxemia. CONCLUSION: Based on our findings, CMV and PC are the major causes of postBMT pneumoniae. In addition, BAL can be considered a safe and accurate procedure for the evaluation of pulmonary complications after BMT.
Anoxia ; Bone Marrow Transplantation* ; Bone Marrow* ; Bronchoscopy* ; Coinfection ; Diagnosis* ; Female ; Glass ; Humans ; Leukemia ; Lung ; Male ; Mortality ; Pneumocystis ; Pneumonia* ; Respiratory Insufficiency ; Siblings ; Streptococcus ; Tissue Donors ; Tuberculosis

PURPOSE: To demonstrate the mammographic and sonographic appearances of metaplastic carcinoma of the breast. MATERIALS AND METHODS: The mammographic and sonographic findings in eight female patients (aged: 28-78 years, mean: 50.3 years) with pathologically proven metaplastic cancer were analyzed retrospectively by three radiologists. We analyzed the size, density, shape, margin, associated architectural distortion, calcification in the mass and enlarged lymph node at the axilla, on the mammograms. We also analyzed the shape, margin and echogenicity of the lesions on the sonograms. RESULTS: On mammography, irregular (n=4), lobular (n=2) or oval (n=2) shaped high density masses were found. The margins of the masses were indistinct (n=4) or obscured (n=3). There were architectural distortions in three cases and pleomorphic calcifications in two cases. On sonography, irregular (n=5) or oval (n=3) shaped masses with microlobulated margins were found. The echopatterns of the masses were complex (n=5) or hypoechoic (n=3). CONCLUSION: The mammographic and sonographic findings of metaplastic carcinoma of the breast are nonspecific and similar to those of other forms of breast cancer. However, this type of tumor should be included in the differential diagnosis for breast masses which appear as an irregular or oval shape with a microlobulated margin and a complex or hypoechoic echopattern on sonography.
Axilla ; Breast Neoplasms ; Breast* ; Diagnosis, Differential ; Female ; Humans ; Lymph Nodes ; Mammography ; Retrospective Studies ; Ultrasonography*

Disseminated mucormycosis is a rare fungal infectious disease with a high mortality rate and is infrequently diagnosed ante mortem. It is most frequently seen in immunocompromised hosts such as diabetes mellitus, hematologic malignancies, or in the long-term use of steroids or chemotherapeutic agents. Tissue invasion by the hyphae of mucormycosis must be seen microscopically to establish the diagnosis. Treatment consists of correction of the predisposing condition, surgical debridement, and amphotericin-B therapy. A 35-year-old man was admitted through the emergency room due to fever and the right flank pain. He had received an allogenic bone marrow transplantation eight months ago and had been medicated with prednisolone and cyclosporine since the procedure. He was diagnosed with disseminated mucormycosis that involved the spleen, right kidney, and right lung. He is being successfully treated with amphotericin B, flucytosine, and liposomal amphotericin B.
Adult ; Amphotericin B ; Ants ; Bone Marrow Transplantation* ; Bone Marrow* ; Communicable Diseases ; Cyclosporine ; Debridement ; Diabetes Mellitus ; Diagnosis ; Emergency Service, Hospital ; Fever ; Flank Pain ; Flucytosine ; Hematologic Neoplasms ; Humans ; Hyphae ; Immunocompromised Host ; Kidney ; Lung ; Mortality ; Mucormycosis* ; Prednisolone ; Spleen ; Steroids

PURPOSE: To assess the effect of extracranial-intracranial (EC-IC) bypass surgery on hemodynamic improvement, we evaluated serial regional cerebral hemodynamic change of the middle cerebral artery (MCA) in symptomatic patients with atherosclerotic occlusion of the internal carotid artery (ICA) or MCA using (99m)Tc-ECD acetazolamide stress brain perfusion SPECT (Acetazolamide SPECT). MATERIAL AND METHODS: The patients who had suffered a recent stroke with atherosclerotic ICA or MCA occlusion underwent EC-IC bypass surgery and Acetazolamide SPECT at 1 week before and three to six months after surgery. For image analysis, attenuation corrected images were spatially normalized to SPECT templates with SPM2. Anatomical automated labeling was applied to calculate mean counts of each Volume-Of-Interest (VOI). Seven VOIs of bilateral frontal, parietal, temporal regions of the MCA territory and the ipsilateral cerebellum were defined. Using mean counts of 7 VOIs, cerebral perfusion index and perfusion reserve index were calculated. RESULTS: Seventeen patients (M:F=12:5, mean age: 53+/-2yr) were finally included in the analysis. The cerebral blood flow of the parietal region increased at 1 week (p=0.003) and decreased to the preoperative level at 3-6 months (p=0.003). The cerebrovascular reserve of the frontal and parietal regions increased significantly at 1 week after surgery (p<0.01) and improved further at 3-6 months. CONCLUSION: Cerebrovascular reserve of the MCA territory was significantly improved at early postoperative period after EC-IC bypass and kept improved state during long-term follow-up, although cerebral blood flow did not significantly improved. Therefore, cerebrovascular reserve may be a good indicator of postoperative hemodynamic improvement resulted from bypass effect.
Acetazolamide ; Atherosclerosis ; Brain ; Carotid Artery, Internal ; Cerebellum ; Cerebral Arteries ; Cerebral Revascularization ; Follow-Up Studies ; Hemodynamics ; Humans ; Middle Cerebral Artery ; Perfusion ; Postoperative Period ; Stroke ; Tomography, Emission-Computed, Single-Photon