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Single-photon Emission (single-photon + emission)
Terms modified by Single-photon Emission Selected AbstractsSimple Partial Status Epilepticus Localized by Single-Photon Emission Computed Tomography Subtraction in Chronic Cerebral ParagonimiasisJOURNAL OF NEUROIMAGING, Issue 4 2004Eun Yeon Joo ABSTRACT A patient with chronic cerebral paragonimiasis began to have new motor seizures of the right face manifested by clonic contractions that occurred several hundred times a day, consistent with simple partial status epilepticus. Ictal electroencephalogram discharges started from the left frontal region and then spread to the left hemisphere with left frontal maximum. But clinical seizures were limited to the right face. The frequent partial seizures were controlled by the intravenous infusion of phenytoin. Brain magnetic resonance imaging showed multiple conglomerated round nodules with encephalomalacia in the left temporal and occipital lobes. Applying the technique of ictal-interictal single-photo emission computed tomography subtraction, the authors were able to localize the focal ictal-hyperperfusion on left precentral cortex adjacent to the lesions that correspond to the anatomical distribution of left face motor area. [source] Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging in the Diagnosis of Left Main DiseaseCLINICAL CARDIOLOGY, Issue 12 2009Luis Afonso MD Background Left main disease (LMD), defined as , 50% lesion stenosis, occurs in 3% to 5% of patients undergoing catheterization. Limited data on the value of single-photon emission computed tomography (SPECT) imaging for diagnosis of LMD exists. Hypothesis This study sought to evaluate the diagnostic accuracy of SPECT imaging in the diagnosis of LMD. Methods A total of 74 consecutive patients with LMD, identified from our catheterization lab database (January 2003,December 2007) with gated exercise (15 patients) or adenosine (59 patients), thallium 201, or Tc-99m SPECT imaging within 6 months of index angiography were included. Group 1 (Gp 1) included 33 patients with isolated LMD. Group 2 (Gp 2) consisted of 41 patients with LMD and 1-vessel disease (6); LMD and 2-vessel disease (24); and LMD and 3-vessel disease (11). Results Reversible perfusion defects (PD) were absent in 6 (18%) of Gp 1 and 8 (20%) of Gp 2 patients. Among Gp 1 patients, PD in 1-vessel, 2-vessel, 3-vessel distribution were seen in 20 (61%), 5 (15%), and 2 (6%) patients respectively. In comparison, PD in 1-vessel, 2-vessel, 3-vessel distribution were observed in 20 (49%), 12 (29%), and 1 (2%) of Gp 2 patients respectively. Left main (LM) pattern was noted in 6 patients (Gp 1: 2, Gp 2: 4). Transient ischemic dilatation (TID) was encountered in 34 patients (Gp 1: 17, Gp 2: 17) and in 4 patients with normal perfusion scans. Conclusions These data represent the largest analysis of patients with "isolated" LMD. Approximately 19% of patients with LMD have no reversible PD on SPECT. While LM pattern is rare, 1-vessel distribution PD and TID represent the most frequent SPECT abnormalities. Copyright © 2009 Wiley Periodicals, Inc. [source] Single-photon and photon-pair emission from CdSe/Zn(S,Se) quantum dotsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003S. Strauf Abstract We report on the generation of triggered single photons and photon pairs relying on pulsed optical excitation of epitaxially grown self-assembled CdSe quantum dots (QDs). Single-photon emission is studied on individual CdSe/Zn(S,Se) QDs for temperatures up to 200 K. At low temperatures nearly perfect single-photon emission is achieved whereas at higher temperatures an increasing multi-photon emission probability due to spectrally overlapping acoustic phonon sidebands of neighboring QDs is observed. The multi-photon emission probability of a bare QD (background subtracted) is strongly suppressed. Furthermore, the polarization cross correlation of the biexciton,exciton cascade has been investigated in a CdSe/ZnSe QD at low temperatures. A strong polarization correlation of the emitted photon pairs of ,74% is observed in a linear detection basis. [source] Characteristics of patients with abnormal stress technetium Tc 99m sestamibi SPECT studies without significant coronary artery diameter stenosesCLINICAL CARDIOLOGY, Issue 11 2003Peter Ammann M.D. Abstract Background: Single-photon emission computed tomography (SPECT) sestamibi (MIBI) is an excellent tool for detection of coronary artery disease (CAD), preoperative risk assessment, and follow-up management after coronary revas-cularization. While the sensitivity of MIBI SPECT for detecting CAD has been reported to exceed 90%, the specificity ranges between 53,100%. Hypothesis: The study was undertaken to assess characteristics of patients with abnormal stress technetium Tc 99m sestamibi SPECT (MIBI) studies without significant coronary artery diameter stenoses (< 50%). Methods: Between January 1999 and November 2000, 270 consecutive patients were referred for coronary angiography due to reversible MIBI uptake defects during exercise. In 41 patients (15%; 39% women, mean age 59 ± 9 years), reversible MIBI uptake defects were assessed although coronary angiography showed no significant CAD. These patients were compared with age- and gender-matched patients with perfusion abnormalities (39% women, mean age 60 ± 9 years), due to significant CAD (coronary artery stenosis > 50%). Results: There were no significant differences between the two groups regarding body mass index, left bundle-branch block (LBBB), or method of stress test (dipyridamole in patients with LBBB or physical inactivity [n= 11] and exercise in all the others [n= 30]). Left ventricular hypertrophy (44 vs. 23%, p = 0.05) and left anterior fascicularblock (LAFB) (17 vs. 0%, p = 0.005) were more common in patients with perfusion abnormalities with no significant CAD, whereas ST-segment depression during exercise (17 vs. 37% p = 0.05) and angina during exercise (15 vs. 29%, p = 0.02) were significantly less common than in patients with abnormal MIBI perfusion studies and angiographically significant CAD. Sestamibi uptake defects during exercise were significantly smaller in patients without significant CAD than in matched controls with significant CAD (p < 0.0004). Conclusion: Of 270 consecutive patients, 41 (15%) referred to coronary angiography due to reversible MIBI uptake defects showed coronary artery stenoses <50%. Twenty-six (10%) of these presented angiographically normal coronary arteries. The significantly higher proportion of left ventricular hypertrophy and LAFB in patients with reversible MIBI uptake defects without significant CAD suggest microvascular disease, angiographically underestimated CAD, and conduction abnormalities as underlying mechanisms. [source] Striatal dopamine D2 receptor availability in OCD with and without comorbid social anxiety disorder: preliminary findings,DEPRESSION AND ANXIETY, Issue 1 2008Franklin R. Schneier M.D. Abstract Dopamine D2 receptor availability in the striatum has been reported to be low in generalized social anxiety disorder (GSAD) and obsessive,compulsive disorder (OCD), but it has not been studied in persons with comorbid OCD and GSAD (OCD+GSAD). D2 receptor availability was assessed in 7 subjects with OCD+GSAD, 8 with OCD, and 7 matched healthy comparison (HC) subjects, all unmedicated adults. D2 receptor availability was assessed with single-photon emission computerized tomography (SPECT) to measure binding potential (BP) of the D2 receptor radiotracer [123I] iodobenzamide ([123I]IBZM). Mean striatal [123I]IBZM BP was significantly lower in the OCD+GSAD group (72.58 mL/g, SD=18.17) than in the HC group (118.41 mL/g, SD=45.40; P=.025). Mean BP in the OCD group (93.08 mL/g, SD=36.90) did not differ significantly from the HC group (P=.247). Trait detachment, as measured by the Detachment subscale of the Karolinska Scales of Personality, was negatively correlated with D2 availability across all subjects (rs=,.55, P=.013). Comorbid GSAD and OCD may be associated with decreased availability of D2 receptors in the striatum, consistent with prior findings in GSAD. Prior findings of decreased D2 receptor availability in noncomorbid OCD were not confirmed. Decreased D2 receptor availability was also associated with trait detachment, supporting prior findings in samples of healthy subjects. Depression and Anxiety 0:1,7, 2007. Published 2007 Wiley-Liss, Inc. [source] Serotonin and dopamine transporter binding in children with autism determined by SPECTDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 8 2008Ismo Makkonen MD Disturbances in the serotonergic system have been recognized in autism. To investigate the association between serotonin and dopamine transporters and autism, we studied 15 children (14 males, one female; mean age 8y 8mo [SD 3y 10mo]) with autism and 10 non-autistic comparison children (five males, five females; mean age 9y 10mo [SD 2y 8mo]) using single-photon emission computed tomography (SPECT) with [123I] nor-,-CIT. The children, with autism were studied during light sedation. They showed reduced serotonin transporter (SERT) binding capacity in the medial frontal cortex, midbrain, and temporal lobe areas. However, after correction due to the estimated effect of sedation, the difference remained significant only in the medial frontal cortex area (p=0.002). In the individuals with autism dopamine transporter (DAT) binding did not differ from that of the comparison group. The results indicate that SERT binding capacity is disturbed in autism. The reduction is more evident in adolescence than in earlier childhood. The low SERT binding reported here and the low serotonin synthesis capacity shown elsewhere may indicate maturation of a lesser number of serotonergic nerve terminals in individuals with autism. [source] Cerebral cortical laminar necrosis on diffusion-weighted MRI in hypoglycaemic encephalopathyDIABETIC MEDICINE, Issue 8 2005Y. Yoneda Abstract Background Laminar necrosis of the cerebral cortex characterized neuropathologically by delayed selective neuronal necrosis occurs in hypoglycaemic encephalopathy and other brain diseases. Case report A 37-year-old male with insulin-treated Type 1 diabetes mellitus developed hypoglycaemic encephalopathy associated with respiratory failure. Brain diffusion-weighted MRI during the subacute period demonstrated high signals along the cerebral cortex. Brain single-photon emission computed tomography showed diffuse, severe cerebral hypoperfusion. The patient remained comatose and died 1 month later. Conclusions High signals along the cortical bands on diffusion-weighted MRI suggest cortical laminar necrosis, although a postmortem examination was unavailable. Sustained hypoglycaemic brain injury, possibly associated with respiratory hypoxia, may be the underlying mechanism. [source] Diagnostic and Prognostic Value of Myocardial Perfusion Imaging in Patients with Known or Suspected Stable Coronary Artery DiseaseECHOCARDIOGRAPHY, Issue 6 2000Aman M. Amanullah M.D., Ph.D. Coronary artery disease is the leading cause of complications and death in the United States and other Western countries, and stress myocardial perfusion study is an important component of the clinical evaluation, stratification, and management. This imaging technique is a well-established modality and has been widely used for the past three decades. New quantitative techniques for the assessment of ventricular function using quantitative gated single-photon emission computed tomography in addition to myocardial perfusion will potentially enhance the role of nuclear cardiology in the management of these patients. This review summarizes the current knowledge of the diagnostic and prognostic uses of stress myocardial perfusion imaging using exercise and pharmacological stress in patients with stable coronary artery disease. [source] Neural Network Underlying Ictal Humming Demonstrated by Very Early SPECT: A Case ReportEPILEPSIA, Issue 11 2006Eric Guedj Summary:, We report the case of a 49-year-old right-handed woman with brief partial seizures in which the clinical semiology was marked by an early humming automatism. MRI fusion of the registered ictal and interictal single-photon emission computed tomography (SPECT) substraction exhibited a left neural network involving lateral temporal, inferior frontal, and inferior parietal cortices. [source] Ictal Brain Hyperperfusion Contralateral to Seizure Onset: The SPECT Mirror ImageEPILEPSIA, Issue 1 2006Gilles Huberfeld Summary:,Purpose: Ictal single-photon emission computed tomography (SPECT) may help localize the seizure-onset zone (SOZ) by detecting changes in regional cerebral blood flow induced by epileptic discharges. This imaging method also reveals hyperperfusions in areas of seizure propagation, including the hemisphere contralateral to the SOZ. We have studied the occurrence, the topography, and the clinical value of such contralateral ictal hyperperfusion areas (HPAs). Methods: We examined data from presurgical evaluations of 36 consecutive patients with pharmacoresistant partial epilepsy of various localizations. Ictal and interictal SPECT examinations were made with 99mTc-ECD, and the scans were processed for coregistration, normalization, subtraction, and merging with MRI images. Results: Contralateral HPAs were observed in 72% of the patients: 50% of mesiotemporal epilepsy cases with hippocampal sclerosis, 85.7% of the other mesiotemporal epilepsies, 85.7% of neocortical lateral temporal epilepsies, and 87.5% of extratemporal epilepsies. Contralateral HPAs were usually symmetrical to the SOZ, forming a mirror image, observed in 57.1% of the patients. They could be slightly asymmetrical in mesiotemporal epilepsies, perhaps because of the particular anatomic pathways linking temporal lobes. In neocortical epilepsies, they were located in the cortex homotopic to the SOZ. Conclusions: We show that the symmetrical nature of the mirror image usually does not disturb SPECT interpretation. It can confirm the location of the SOZ (11 patients) and even occasionally improve the precision of its definition (nine patients) by restraining several potential SOZ-related HPAs to a single one or by permitting a restricted localization of the SOZ in a large HPA. [source] Dystonic Posturing Associated with Putaminal Hyperperfusion Depicted on Subtraction SPECTEPILEPSIA, Issue 8 2004Masahiro Mizobuchi Summary:,Purpose: Dystonic posturing (DP) is one of the most reliable lateralizing indicators for temporal lobe epilepsy (TLE). We evaluated the ictal hyperperfusional areas in patients with DP by using ictal,interictal subtraction single-photon emission computed tomography (SPECT). Methods: Ninety-seven patients were treated surgically for intractable TLE, and 39 patients underwent ictal and interictal SPECT studies with the same isotope. These patients were divided into three groups: group I with DP of the contralateral side extended to the epileptogenic focus, group II with elevated muscle tonus but without DP, and group III without DP or alteration of muscle tonus. Ictal, interictal SPECT and thin-slice magnetic resonance imaging (MRI) were overlaid by using the automatic multimodality registration program to construct ictal,interictal subtracted images of SPECT on MRI. Results: Thirteen patients belonged to group I; 14, to group II; and 12, to group III. A statistically significant difference in hyperperfusion rate was observed in the putamen (10 patients in group I, three in group II and two in group III; p < 0.01) and mesial temporal lobe (10 patients in group I, seven in group II, and two in group III; p < 0.05) on the ipsilateral side of the epileptogenic focus. No statistically significant difference was observed for other ictal symptoms except ipsilateral upper-limb automatism (eight patients in group I, three in group II, and none in group III; p < 0.01). Conclusions: A strong correlation between DP and hyperperfusion in the putamen and mesial temporal lobe was demonstrated. Some patients showed a wide hyperperfusion area extending from the mesial temporal lobe to putamen, which may correspond to the propagation of epileptic discharges. Our results suggest a correlation between hyperperfusion of putamen and contralateral dystonic posturing. [source] Subtraction SPECT Coregistered to MRI in Focal Malformations of Cortical Development: Localization of the Epileptogenic Zone in Epilepsy Surgery CandidatesEPILEPSIA, Issue 4 2004Terence J. O'Brien Summary: Purpose: To determine the extent to which periictal subtraction single-photon emission computed tomography (SPECT) may improve detection and definition of the epileptogenic zone in patients with focal malformations of cortical development (MCDs). Methods: Subtraction SPECT coregistered to magnetic resonance (MR) images (SISCOM) were constructed for 22 consecutive patients with focal MCDs who underwent periictal SPECT injection (18 ictal and four postictal). In the 17 patients who had epilepsy surgery, concordance between the site of SISCOM localization and site of surgical resection was determined by coregistration of SISCOM images with postoperative MRIs. Results: SISCOM images were localizing in 19 (86%) patients, including eight of the 10 with nonlocalizing MRI. Concordance of SISCOM localization was 91% with MRI localization, 93% with scalp ictal EEG localization, and 100% with intracranial EEG localization. Eight patients whose SISCOM localization was concordant with the surgical resection site had lower postoperative seizure frequency scores (SFSs; p = 0.04) and greater postoperative improvement in SFSs (p = 0.05) than the nine patients whose SISCOM was either nonconcordant or nonlocalizing. On multiple regression analysis, a model combining SISCOM concordance with surgical resection site and extent of MRI lesion resection was predictive of postoperative SFS (R2= 0.47; p = 0.03). Conclusions: Periictal subtraction SPECT using the SISCOM technique provides useful information for seizure localization in patients with focal MCDs, even when MRI is nonlocalizing. [source] Neuroradiologic Findings in Focal Cortical Dysplasia: Histologic Correlation with Surgically Resected SpecimensEPILEPSIA, Issue 2001Kazumi Matsuda Summary: ,Purpose: We investigated the neuroradiologic characteristics of focal findings of surgically resected specimens obtained from 47 patients with focal cortical dysplasia (FCD). Methods: Forty cases were detected by magnetic resonance imaging (MRI), and two cases were detected only by single-photon emission computed tomography (SPECT), but five cases could not be detected before operation. Results: MRI revealed abnormal gyri and sulci in 34 patients (pachygyric in 18, polymicrogyric in 10, both in six), and blurring of the gray matter,white matter junction in 29 (72%) patients. Signal abnormalities were found in 36 (90%) patients, in the gray matter in 32, with white matter in 30, and at the gray matter,white matter junction in 13. Moreover, peculiar patterns of abnormal signals in the white matter were recognized, including remarkably abnormal subcortical signals of T2 hyperintensity and T1 hypointensity adjacent to the dysplastic cortex in 15 cases, high radiated T2 signals extending from the ependymal surface of the lateral ventricle to the overlying cortex in 11 cases, and widespread abnormal signals in the white matter with gray matter involvement in four cases. Histologically, these abnormal signals corresponded to various degrees of dyslamination and morphologic abnormalities of neurons and glial cells in the gray matter, and to dysmyelination, ectopic clustering of dysplastic neurons, glial proliferation, and necrotic change in the white matter. Regional cerebral blood flow SPECT showed interictal hypoperfusion in 29 (62%) of the 47 patients, interictal hyperperfusion in two, and ictal hyperperfusion in 28 of the 34 patients associated with FCD. [123I]iomazenil SPECT demonstrating the distribution of central benzodiazepine receptors showed low accumulations localized spatially corresponding to the epileptogenic foci associated with FCD in seven of eight patients. Conclusions: These results demonstrate that neuroimaging reflects various structural and functional changes closely related to epileptogenesis in FCD. [source] Thiethylperazine-induced parkinsonism: in vivo demonstration of dopamine D2 receptors blockadeEUROPEAN JOURNAL OF NEUROLOGY, Issue 10 2004C. Briani Thiethylperazine (Torecan®) is a piperazine phenothiazine employed to relieve vertigo. Its use may be associated with extrapyramidal side effects (dystonia, akathisia, tardive dyskinesia) (Sulkava, 1984), but parkinsonism has rarely been described. We describe a woman who, 1 month after the onset of thiethylperazine treatment, developed parkinsonism that disappeared 2 months after withdrawal of the drug. However, cerebral single-photon emission computed tomography (SPECT) with the dopamine (DA) D2 receptors ligand 123I-iodobenzamide (123I-IBZM) revealed a persistent reduced DA D2 receptors activity (by 45%) in the basal ganglia (BG), which may be clinically not effective. [source] Neurophysiological tests and neuroimaging procedures in non-acute headache: guidelines and recommendationsEUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2004G. Sandrini The use of instrumental examinations in headache patients varies widely. In order to evaluate their usefulness, the most common instrumental procedures were evaluated, on the basis of evidence from the literature, by an EFNS Task Force (TF) on neurophysiological tests and imaging procedures in non-acute headache patients. The conclusions of the TF regarding each technique are expressed in the following guidelines for clinical use. 1Interictal electroencephalography (EEG) is not routinely indicated in the diagnostic evaluation of headache patients. Interictal EEG is, however, indicated if the clinical history suggests a possible diagnosis of epilepsy (differential diagnosis). Ictal EEG could be useful in certain patients suffering from hemiplegic and basilar migraine. 2Recording of evoked potentials is not recommended for the diagnosis of headache disorders. 3There is no evidence to justify the recommendation of autonomic tests for the routine clinical examination of headache patients. 4Manual palpation of pericranial muscles, with standardized palpation pressure, can be recommended for subdividing patient groups but not for diagnosis. Pressure algometry and electromyography (EMG) cannot be recommended as clinical diagnostic tests. 5In adult and paediatric patients with migraine, with no recent change in attack pattern, no history of seizures, and no other focal neurological signs or symptoms, the routine use of neuroimaging is not warranted. In patients with atypical headache patterns, a history of seizures and/or focal neurological signs or symptoms, magnetic resonance imaging (MRI) may be indicated. 6If attacks can be fully accounted for by the standard headache classification [International Headache Society (IHS)], a positron emission tomography (PET) or single-photon emission computerized tomography (SPECT) and scan will generally be of no further diagnostic value. 7Nuclear medicine examinations of the cerebral circulation and metabolism can be carried out in subgroups of headache patients for diagnosis and evaluation of complications, when patients experience unusually severe attacks, or when the quality or severity of attacks has changed. 8Transcranial Doppler examination is not helpful in headache diagnosis. Although many of the examinations described are of little or no value in the clinical setting, most of the tools have a vast potential for further exploring the pathophysiology of headaches and the effects of pharmacological treatment. [source] Extranodal NK/T-cell lymphoma, nasal type, presenting after 5 years of remissionINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 3 2008Tomonobu Ito MD A 76-year-old woman with multiple edematous erythemas, erosions, and ulcers on the breast and abdomen was admitted to our hospital in June 2005. She had developed granulomatous bleeding lesions in the right nostril 6 years prior to her visit to our dermatology unit. She had been observed at the otorhinolaryngology department of our hospital, and a biopsy was taken from the nasal lesion. Computerized tomography and gallium scintigraphy (67Ga single-photon emission computed tomography) did not reveal any lesions corresponding to the diagnosis of malignant lymphoma. The histologic examination of the nasal specimen rendered a diagnosis of natural killer (NK)/T-cell lymphoma, nasal. Because imaging analysis indicated a small-sized tumor without metastases, oral prednisolone at 20 mg/day was administered for 1 month. The tumor decreased in size and disappeared after 19 months of low-dose steroid therapy. ,Five years after the initial treatment, the patient developed a fever of 38 °C with infiltrated erythemas and erosions on her breast. Erysipelas was initially suspected, but the antimicrobial agent did not show any effect and the multiple infiltrated erythemas and ulcers spread throughout her chest and abdomen (Fig. 1). The lymph nodes were not palpable. The right nasal cavity showed no granulomatous lesions or other signs of abnormality. The peripheral white blood cell count (3000/µL), red blood cell count (3.54 × 106/µL), and platelet count (112 × 103/µL) were reduced. Atypical lymphocytes were not observed. The serum lactic dehydrogenase (LDH; 1770 U/L; normal, 224,454 U/L), aspartate aminotransferase (AST; 140 U/L; normal, 10,30 U/L), and alanine aminotransferase (ALT; 57 U/L; normal, 3,29 U/L) levels were elevated. The soluble interleukin-2 (IL-2) receptor level was high (25,300 U/mL; normal, 167,497 U/mL). Epstein,Barr virus (EBV) serologic examination showed the immunoglobulin G (IgG) viral capsid antigen (VCA) at 1 : 320 and the EBV nuclear antigen (EBNA) at 1 : 40. IgM VCA and EBV early antigen-diffuse restricted antibody (EA) IgA and IgG were not detectable. Histologic findings from the left chest skin showed a distribution of atypical lymphocytes from the upper dermis to the subcutaneous tissue, and many foamy cells which had phagocytosed the hemocytes (Fig. 2a,b). Immunohistochemical analysis showed that the atypical lymphocytes were sCD3,, CD4,, CD8,, CD20,, CD56+, granzyme B+, and T-cell intracellular antigen (TIA-1) positive. Furthermore, EBV-encoded small RNAs (EBER), detected by in situ hybridization, exhibited a strong signal. The nasal lesions biopsied 6 years previously showed an identical staining pattern with the skin lesions immunohistochemically. Analysis of the T-cell receptor-, (TCR-,), TCR-,, and TCR-, gene did not reveal any clonal rearrangements, but the EBV gene was detected from the skin specimens by Southern blotting. Our patient's condition was diagnosed as a case of extranodal NK/T-cell lymphoma, nasal type, but the patient had concomitantly developed hemophagocytic syndrome (HPS). She was treated with a combination of steroid pulse therapy and chemotherapy (pirarubicin hydrochloride 30 mg/m2, cyclophosphamide 500 mg/m2, vincristine 1 mg/m2, prednisolone 30 mg/m2, etoposide 80 mg/m2). After the first session of chemotherapy, the lesions on the chest and abdomen diminished, but, 2 weeks later, the skin lesions recurred, and disseminated intravascular coagulation (DIC) induced by HPS supervened. The patient died as a result of multiple organ failure induced by HPS. Figure 1. Multiple infiltrated erythemas, erosions, and ulcers on the breast and abdomen Figure 2. Histologic findings of a skin biopsy specimen from the left chest (hematoxylin and eosin staining). (a) Dense infiltration of atypical lymphocytes from the upper dermis to the subcutaneous tissue (×40). (b) Many foamy cells had phagocytosed the hemocytes (×400) [source] Parameter estimation in Bayesian reconstruction of SPECT images: An aid in nuclear medicine diagnosisINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 1 2004Antonio López Abstract Despite the adequacy of Bayesian methods to reconstruct nuclear medicine SPECT (single-photon emission computed tomography) images, they are rarely used in everyday medical practice. This is primarily because of their computational cost and the need to appropriately select the prior model hyperparameters. We propose a simple procedure for the estimation of these hyperparameters and the reconstruction of the original image and test the procedure on both synthetic and real SPECT images. The experimental results demonstrate that the proposed hyperparameter estimation method produces satisfactory reconstructions. Although we have used generalized Gaussian Markov random fields (GGMRF) as prior models, the proposed estimation method can be applied to any priors with convex potential and tractable partition function with respect to the scale hyperparameter. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 21,27, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20003 [source] Real time non-invasive imaging of receptor,ligand interactions in vivoJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2003Paul Winnard Abstract Non-invasive longitudinal detection and evaluation of gene expression in living animals can provide investigators with an understanding of the ontogeny of a gene's biological function(s). Currently, mouse model systems are used to optimize magnetic resonance imaging (MRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and optical imaging modalities to detect gene expression and protein function. These molecular imaging strategies are being developed to assess tumor growth and the tumor microenvironment. In addition, pre-labeling of progenitor cells can provide invaluable information about the developmental lineage of stem cells both in organogenesis and tumorigenesis. The feasibility of this approach has been extensively tested by targeting of endogenous tumor cell receptors with labeled ligand (or ligand analog) reporters and targeting enzymes with labeled substrate (or substrate analog). We will primarily discuss MRI, PET, and SPECT imaging of cell surface receptors and the feasibility of non-invasive imaging of gene expression using the tumor microenvironment (e.g., hypoxia) as a conditional regulator of gene expression. © 2003 Wiley-Liss, Inc. [source] Magnetic resonance voiding cystography in the diagnosis of vesicoureteral reflux: Comparative study with voiding cystourethrography,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2005Sang Kwon Lee MD Abstract Purpose To evaluate the feasibility of magnetic resonance voiding cystography (MRVC) compared with voiding cystourethrography (VCUG) for detecting and grading vesicoureteral reflux (VUR). Materials and Methods MRVC was performed upon 20 children referred for investigation of reflux. Either coronal T1-weighted spin-echo (SE) or gradient-echo (GE) (fast multiplanar spoiled gradient-echo (FMPSPGR) or turbo fast low-angle-shot (FLASH)) images were obtained before and after transurethral administration of gadolinium solution, and immediately after voiding. The findings of MRVC were compared with those of VCUG and technetium-99m (99mTc) dimercaptosuccinic acid (DMSA) single-photon emission computed tomography (SPECT) performed within 6 months of MRVC. Results VUR was detected in 23 ureterorenal units (16 VURs by both methods, 5 VURs by VCUG, and 2 VURs by MRVC). With VCUG as the standard of reference, the sensitivity of MRVC was 76.2%; the specificity, 90.0%; the positive predictive value, 88.9%; and the negative predictive value, 78.3%. There was concordance between two methods regarding the grade of reflux in all 16 ureterorenal units with VUR detected by both methods. Of 40 kidneys, MRVC detected findings of renal damage or reflux nephropathy in 13 kidneys, and 99mTc DMSA renal SPECT detected findings of reflux nephropathy in 17 kidneys. Conclusion Although MRVC is shown to have less sensitivity for VUR than VCUG, MRVC may represent a method of choice offering a safer nonradiation test that can additionally evaluate the kidneys for changes related to reflux nephropathy. J. Magn. Reson. Imaging 2005;21:406,414. © 2005 Wiley-Liss, Inc. [source] The effects of degeneracy of atomic levels on single-photon emission via Raman scatteringLASER PHYSICS LETTERS, Issue 8 2008V.A. Reshetov Abstract The three-level , -type atom with degenerate atomic levels is considered, one of its transitions being driven by the coherent field, the other being coupled to the single-mode quantized field of the high-Q cavity. The probability of emission of a single photon in the cavity via Raman scattering versus the mutual orientation of polarization vectors of the cavity mode and of the driving coherent pulse is studied. The efficiency of the retrieval of a single-photon excitation, stored in the atomic ground state (as suggested, e.g., in paper [1]), versus the mutual orientation of polarizations of cavity modes and of the coherent "write" and "read" pulses is also investigated. The numerical calculations are carried out for the transitions between hyperfine components of the ground 6S1/2 and excited 6P3/2 states of Cesium atoms, which were exploited in the experiments [1]. The optimal polarizations providing the maximum probability of photon emission and maximum retrieval efficiency are determined. (© 2008 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Lesion of the dorsorostral midbrain sparing the nigrostriatal tract mimics axial rigidity seen in progressive supranuclear palsyMOVEMENT DISORDERS, Issue 8 2005Jan Lewerenz MD Abstract We report on a patient with a residual dorsorostral midbrain lesion after resection of a pineal gland tumor. In addition to severe vertical gaze palsy, this patient exhibited other neurological features closely resembling progressive supranuclear palsy. Normal dopamine transporter single-photon emission computed tomography imaging excluded significant dopamine deficiency. We suggest that dorsorostral midbrain pathology rather than dopamine deficiency due to degeneration of nigrostriatal dopaminergic neurons or basal ganglia nuclei might be responsible for axial rigidity in extension. © 2005 Movement Disorder Society [source] Dopamine transporter: Basic aspects and neuroimagingMOVEMENT DISORDERS, Issue S7 2003Paola P. Piccini MD Abstract The plasma membrane dopamine transporter (DAT) is found exclusively in dopamine neurones and seems to be the defining molecule of the dopamine neurone. It provides effective control over the intensity of dopamine-mediated signalling by recapturing the neurotransmitter released by presynaptic neurones. Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) represent unique techniques for assessing in vivo DAT distribution in humans and offer reliable methods for studying nigrostriatal dopaminergic function in health and disease. The characteristics of different DAT radiotracers, the modifying influences of factors such as age, gender, smoking habit, and dopaminergic drugs on DAT transporters as well as their implication in evaluation of neuroimaging studies are discussed. © 2003 Movement Disorder Society [source] The role of neuroimaging in mild cognitive impairmentNEUROPATHOLOGY, Issue 6 2007Hiroshi Matsuda The main purposes of neuroimaging in Alzheimer's disease (AD) have been moved from diagnosis of advanced AD to diagnosis of very early AD at a prodromal stage of mild cognitive impairment, prediction of conversion from mild cognitive impairment (MCI) to AD, and differential diagnosis from other diseases causing dementia. Structural MRI studies and functional studies using F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) and brain perfusion single-photon emission computed tomography (SPECT) are widely used in diagnosis of AD. Outstanding progress in diagnostic accuracy of these neuroimaging modalities has been obtained using statistical analysis on a voxel-by-voxel basis after spatial normalization of individual scans to a standardized brain-volume template instead of visual inspection or a conventional region of interest technique. In a very early stage of AD, this statistical approach revealed gray matter loss in the entorhinal and hippocampal areas and hypometabolism or hypoperfusion in the posterior cingulate cortex and precuneus. These two findings might be related in view of anatomical knowledge that the regions are linked through the circuit of Papez. This statistical approach also offers prediction of conversion from MCI to AD. Presence of hypometabolism or hypoperfusion in parietal association areas and entorhinal atrophy at the MCI stage has been reported to predict rapid conversion to AD. [source] Single-photon and photon-pair emission from CdSe/Zn(S,Se) quantum dotsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003S. Strauf Abstract We report on the generation of triggered single photons and photon pairs relying on pulsed optical excitation of epitaxially grown self-assembled CdSe quantum dots (QDs). Single-photon emission is studied on individual CdSe/Zn(S,Se) QDs for temperatures up to 200 K. At low temperatures nearly perfect single-photon emission is achieved whereas at higher temperatures an increasing multi-photon emission probability due to spectrally overlapping acoustic phonon sidebands of neighboring QDs is observed. The multi-photon emission probability of a bare QD (background subtracted) is strongly suppressed. Furthermore, the polarization cross correlation of the biexciton,exciton cascade has been investigated in a CdSe/ZnSe QD at low temperatures. A strong polarization correlation of the emitted photon pairs of ,74% is observed in a linear detection basis. [source] Hyperperfusion in primary somatosensory region related to somatic hallucination in the elderlyPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 4 2010Kiyotaka Nemoto MD Aim:, The purpose of the present study was to investigate the regional cerebral blood flow (rCBF) of patients with delusional disorder, somatic type (DDST) exhibiting somatic hallucination. Methods:, Five patients diagnosed with DDST, as well as 20 control subjects, were examined. All subjects underwent technetium-99m ethyl cysteinate dimer brain perfusion single-photon emission computed tomography. Statistical analysis was performed with SPM5, using a two-sample t -test model to test the regional population effect on rCBF. Results:, Patients with DDST had a significant increase in perfusion in the left post-central gyrus and the right paracentral lobule, both of which are involved in somatic sensory processing. Conclusion:, Somatic hallucination might be associated with increased perfusion in the primary somatosensory regions. [source] Neural correlates of memory in depression measured by brain perfusion SPECT at restPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 5 2009Hideki Azuma md Aim:, Brain metabolism activated studies have indicated associations between memory and the anterior cingulate cortex and hippocampus in patients with depression. The aim of the present study was therefore to investigate memory function, measured as performance on the Wechsler Memory Scale,Revised (WMS-R), and its relationship to brain perfusion using single-photon emission computed tomography (SPECT) at rest in patients with depression. Methods:, The Hamilton Rating Scale for Depression (HAMD) and WMS-R were measured for 17 patients with depression by an independent clinical evaluation team. Voxel-based correlation analyses were performed with statistical parametric mapping at an extent threshold of 200 voxels. Associations were controlled for state and trait factors. Results:, WMS-R measurements of verbal, visual, and general memory were inversely correlated with brain perfusion in the right anterior cingulate cortex, left premotor cortices, and both regions, respectively. The HAMD directly correlated with brain perfusion in the right anterior cingulate cortex. Conclusion:, Brain perfusion SPECT measurements of the anterior cingulate cortex at rest were associated with the severity of depression and immediate memory scores measured with the WMS-R. [source] Study of image findings in rapid eye movement sleep behavioural disorderPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 3 2002SHIN-ICHIRO SHIRAKAWA md Abstract To elucidate the cause of idiopathic rapid eye movement (REM) sleep behavior disorder (RBD), magnetic resonance imaging and single-photon emission computed tomography of the brain were conducted on 20 patients with RBD. Blood flow in the upper portion of both sides of the frontal lobe and pons was significantly lower in patients with RBD than in the normal elderly group. Among the patients with RBD, decreased blood flow in the frontal lobe showed no correlation with the extent of frontal lobe atrophy. Decreased blood flow in the upper portion of the frontal lobe and pons might be associated with the pathogenesis of idiopathic RBD. [source] ORIGINAL RESEARCH,ERECTILE DYSFUNCTION: Independent Determinants of Coronary Artery Disease in Erectile Dysfunction PatientsTHE JOURNAL OF SEXUAL MEDICINE, Issue 4pt1 2010Shih-Tai Chang MD ABSTRACT Introduction., There is growing evidence of a link between erectile dysfunction (ED) and coronary artery disease (CAD). Aims., The purpose of this study was to explore the independent determinants of CAD in ED outpatients. Methods., This study enrolled 243 patients, ranging in age from 21 to 81 years old, suffering from ED as diagnosed by the International Index of Erectile Function (IIEF) scores. All patients underwent exercise stress tests or thallium-201 single-photon emission computed tomography perfusion imagings. Based on examination results, patients were divided into study (22 patients with a positive finding) and control groups (221 patients with a negative finding). Main Outcome Measures., The differences of demographic characteristics, biochemical profiles, pro-inflammatory and inflammatory markers, and echocardiographic characteristics between study and control group were compared. Results., The age, presence of DM and current smoking status were significant high in the study group. A significant lower high-density lipoprotein (HDL) cholesterol level, a higher percentage of HDL cholesterol level < 40 mg/dL, and a higher apo-lipoprotein B/A1, high sensitive C-reactive protein (hs-CRP) and homocysteine found in the study group. The Framingham cardiac risk scores, the ratio of mitral inflow velocity to early diastolic velocity in the annulus derived by tissue Doppler imaging (E/Et), the ratio of E/Et , 15, the value of carotid intima-media thickness (IMT), and IMT , 1 mm were higher in study group than in the control group. In stepwise multiple logistic regression analysis, a high waist-to-hip ratio (WHR), high IMT, high E/Et, hs-CRP levels, LDL cholesterol , 130 mg/dL, smoking status, and the presence of DM and metabolic syndrome (MS) were independent determinants of CAD in ED patients. Conclusions., This study first shows the independent determinants of CAD in ED outpatients. This novel finding may improve the screening of low-risk ED patients for CAD. Chang S-T, Chu C-M, Hsu J-T, Hsiao J-F, Chung C-M, Ho C, Peng Y-S, Chen P-Y, and Shee J-J. Independent determinants of coronary artery disease in erectile dysfunction patients. J Sex Med 2010;7:1478,1487. [source] Pediatric moyamoya disease: An analysis of 410 consecutive casesANNALS OF NEUROLOGY, Issue 1 2010Seung-Ki Kim MD Objective Moyamoya disease (MMD) is a cerebrovascular occlusive disease of the bilateral internal carotid arteries that causes a compensatory abnormal vascular network at the base of brain. The rare incidence and various surgical techniques applied have limited the clinical research on MMD. Methods We conducted a retrospective analysis of the surgical outcome of 410 pediatric MMD patients. All patients were treated in a relatively uniform scheme at a single institution. The surgical procedures consisted of bilateral encephaloduroarteriosynangiosis augmented by bifrontal encephalogaleo-/periosteal synangiosis. Logistic regression analyses were applied to reveal the prognostic factors for surgical outcome. Results The overall clinical outcome was excellent in 66%, good in 15%, fair in 15%, and poor in 4% of the patients. Therefore, 81% of the patients had a favorable clinical outcome (excellent and good). Multivariate analyses revealed that infarction on presentation was associated with unfavorable clinical outcome (odds ratio [OR], 2.85; 95% confidence interval [CI], 1.49,5.46; p < 0.01) and decreased vascular reserve only on single-photon emission computerized tomography (OR, 0.07; 95% CI, 0.01,0.52; p < 0.01), with favorable clinical outcome. Interpretation Our results indicate that an early diagnosis and active intervention before establishment of irreversible hemodynamic change are essential to achieve a favorable clinical outcome in children with MMD. ANN NEUROL 2010;68:92,101 [source] Functional imaging: I. Relative predictive value of intracranial electroencephalographyANNALS OF NEUROLOGY, Issue 1 2008MSPH, Robert C. Knowlton MD Objective To gain information on the predictive and prognostic value of magnetic source imaging (MSI), 2-[18F]fluoro-2-deoxy- D -glucose positron emission tomography (18FDG-PET), and ictal single-photon emission computed tomography (SPECT) as compared with intracranial electroencephalography (ICEEG) localization in epilepsy surgery. Methods This work was part of a cohort study of epilepsy surgery candidates not sufficiently localized with noninvasive studies. Of 160 patients enrolled over 4 years, 77 completed ICEEG seizure monitoring. Sensitivity, specificity, and predictive values relative to ICEEG were computed for each modality. Results Seizures were not captured in five patients. Of the 72 diagnostic ICEEG studies, seizure localization results were 74% localized, 10% multifocal, and 17% nonlocalized. Sixty-one percent were localized to neocortical regions. Depending on patient subgroup pairs, sensitivity ranged from 58 to 64% (MSI), 22 to 40% (PET), and 39 to 48% (SPECT); specificity ranges were 79 to 88% (MSI), 53 to 63% (PET), and 44 to 50% (SPECT). Gains in diagnostic yield were seen only with the combination of MSI and PET or MSI and ictal SPECT. Localization concordance with ICEEG was greatest with MSI, but a significant difference was demonstrated only between MSI and PET. Moderate redundancy was seen between PET and ictal SPECT (, = 0.452; p = 0.011). Interpretation Conclusively positive MSI has a high predictive value for seizures localized with ICEEG. Diagnostic gain may be achieved with addition of either PET or ictal SPECT to MSI. Diagnostic values for imaging tests are lower than "true values" because of the limitations of ICEEG as a gold standard. Ann Neurol 2008 [source] | ||||||||||||||||||||||||||||||||||