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Single Photon Emission (single + photon_emission)
Kinds of Single Photon Emission Terms modified by Single Photon Emission Selected AbstractsIdentification of Hemodynamically Significant Restenosis after Percutaneous Transluminal Coronary Angioplasty in Acute Myocardial Infarction by Transesophageal Dobutamine Stress Echocardiography and Comparison with Myocardial Single Photon Emission Computed TomographyJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2001STEPHAN ROSENKRANZ M.D. Background: Beside thrombolysis, percutaneous transluminal coronary angioplasty (PTCA) has become a well-established treatment for acute myocardial infarction. However, restenosis occurs in approximately 15%-40 % of patients. Despite a frequently occurring infarct-related regional systolic dysfunction at rest, the identification of hemodynamically relevant restenosis seems important in terms of risk stratification, adequate treatment, and possible improvement of prognosis in these patients. This study was designed to assess the role of transesophageal dobutamine stress echocardiography and myocardial scintigraphy for identification of hemodynamically significant restenosis after PTCA for acute myocardial infarction. Methods: Multiplane transesophageal stress echocardiography (dobutamine 5, 10, 20, 30, and 40 ,g/kg per min) studies and myocardial single photon emission computed tomography (SPECT) studies were performed in 40 patients, all of whom underwent PTCA in the setting of acute myocardial infarction , 4 months prior to the test. Repeated coronary angiography was performed in all study patients who showed stress-induced perfusion defects or wall-motion abnormalities, or both. Results: Significant restenosis (, 50%) was angiographically found in 15 (37.5%) of 40 patients. Of these 15 patients, transesophageal dobutamine stress echocardiography identified restenosis in 12 (80%) and myocardial SPECT in 14 (93%), yielding diagnostic agreement in 70% of patients. Echocardiographic detection of restenosis was based mainly on a biphasic response to increasing doses of dobutamine. Sensitivity and specificity for identification of hemodynamically relevant restenosis in individual patients was 80% and 92%, respectively for dobutamine stress echocardiography versus 93% and 68% for myocardial SPECT. Conclusions: Both transesophageal dobutamine stress echocardiography and myocardial SPECT were highly sensitive in identifying significant restenosis after PTCA for acute myocardial infarction. Therefore, either test, as a single diagnostic tool or especially if performed together, are clinically valuable alternatives to coronary angiography for the detection of restenosis after PTCA for acute myocardial infarction. [source] Correlation of single photon emission computed tomography with pathology and seizure outcome in children undergoing epilepsy surgeryNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 2 2002J. H. Cross Introduction:, Single photon emission computed tomography (SPECT) imaging regional cerebral blood flow (rCBF) can help localize the seizure focus in partial epilepsies during presurgical evaluation. Few studies have explored the possible relationship between preoperative SPECT and underlying pathology, or any relationship to postsurgical outcome. Study group:, Thirty-five children with medically intractable epilepsy undergoing resective surgery between the ages of 11 months and 18 years had presurgical ictal and interictal rCBF and post surgery follow up of 3,6 years. Results:, Pathological examination revealed 13 to have hippocampal sclerosis (HS): of these 11 had relatively low interictal rCBF perfusion on the side of seizure onset, and eight had hyperfusion ictally. Eight children had morphological evidence of cortical dysplasia: all had a localizing ictal rCBF concordant with the area resected whereas only six demonstrated localized reduction in perfusion on interictal rCBF. All three patients with Rasmussens encephalitis had informative rCBF scans, concordant with the seizure focus. However, infarct, tumours and nonspecific pathology demonstrated poor localization of the seizure focus. No SPECT parameter correlated independently with outcome, although overall the HS group had the best outcome, particularly those with localizing ictal SPECT. Comment:, Ictal SPECT appears predictive of underlying cortical dysplasia. Although in this small group of HS in children, ictal SPECT added little to interictal SPECT for seizure localization, it may be useful in the prediction of outcome. SPECT adds little to the evaluation of children being considered for hemispherectomy over and above the abnormalities detectable on MRI scan. [source] Relationship between psychiatric symptoms and regional cerebral blood flow in patients with mild Alzheimer's diseasePSYCHOGERIATRICS, Issue 3 2008Keisuke NAKAJIMA Abstract Background:, Behavioral and psychological symptoms of dementia (BPSD) are frequently observed in patients with dementia and often cause serious problems. However, the cause of BPSD has not yet been elucidated. Moreover, the precise evaluation of BPSD in mild dementia has not been studied in any great detail. In the present study, we investigated the relationship between psychiatric symptoms and regional cerebral blood flow (rCBF) in patients with mild Alzheimer's disease (AD). Methods:, The present study included 47 patients (20 men and 27 women) who were diagnosed with mild AD. Mean patient age was 72.8 ± 8.2 years. Single photon emission computed tomography (SPECT) with 99mTc-ethyl cysteinate dimer (99mTc-ECD) was performed in all patients. The SPECT data were analyzed using a three-dimensional stereotactic region of interest template, which evaluated CBF in 24 segments. Psychiatric symptoms were evaluated in patients using the Brief Psychiatric Rating Scale. Each psychiatric symptom was designated as ,symptom present' in cases in which the BPRS item score was more than 3. We compared 10 segments of rCBF in symptom-present patients with those in symptom-absent patients. Results:, Motor retardation was the most common psychiatric symptom (36.2%), followed by depression (19.1%), anxiety (17.0%), emotional withdrawal (17.0%), and somatic concern (14.9%). Alzheimer's disease patients with motor retardation exhibited a tendency towards lower rCBF in seven segments (left callosomarginal, bilateral parietal, bilateral angular, and bilateral temporal). However, no specific tendency was observed in depression, anxiety, and somatic concern. Conclusions:, In the present study, we observed a tendency for decreased brain perfusion in patients with motor retardation. Further studies are necessary to confirm that this trend contributes to the appearance of psychiatric symptoms in patients with mild AD. [source] Frontal lobe syndrome or adolescent-onset schizophrenia?ACTA PSYCHIATRICA SCANDINAVICA, Issue 5 2006A case report Objective:, To highlight the difficulties that abound in making a clinical distinction between early-onset schizophrenia (EOS) and juvenile frontal dementia early in the course of illness. Method:, Clinical information and data from investigations in single case was collated and reviewed. Results:, A 15-year-old girl was admitted to our psychiatric unit because of cognitive decline and formal thought disorder with echopraxia, echolalia and palilalia, and a lack of flexibility in the use of cognitive and motor strategies that culminated in psychosis. A single photon emission computerized tomography scan showed marked frontal lobe hypoperfusion; however, on proton spectroscopy there was no differential in N -acetyl aspartate levels. Conclusion:, Hypofrontality in EOS is well established and the association of frontal functional alterations, neuropsychological impairment and psychotic symptomatology is suggestive of frontal lobe prodrome that precedes the onset of psychosis. [source] Perfusional evaluation of postesophagectomy gastroplasty with a radioisotopic studyDISEASES OF THE ESOPHAGUS, Issue 6 2008G. Gabiatti SUMMARY., Anastomotic fistula represents one of the frequent causes of postoperative morbidity and mortality following transhiatal esophageal resections. The main etiological factor is the ischemia of the gastric tube created for digestive transit reconstruction. Evidence suggests that per operative hypoperfusion can be maintained or even impaired after the surgery. Several methods have been employed in an attempt to assess the blood perfusion of the gastric flap, but they all pose limitations. However, there is a chronological relationship between perfusion assessments, which are almost exclusively performed per operatively, and the occurrence of a leak, which commonly appears several days after the surgery. The authors have developed a method of gastric perfusion evaluation by single photon emission computed tomography scintigraphy, which corrects that temporal matter, allowing the estimation of postoperative gastric perfusion. It is noninvasive, low cost, and may be applied by the time frame when most fistulas occur. High correlation between the event fistula and the low radiotracer uptake in the group of studied patients could be demonstrated. A role in the research of perfusion evaluation of different types of esophageal reconstruction is suggested. [source] Viable Myocardium: How Much Is Enough?ECHOCARDIOGRAPHY, Issue 1 2005A Comparison of Viability by Comparative Imaging Techniques to Assess the Quantity, Functionality of Ischemic Myocardium Left ventricular systolic dysfunction is mainly a result of coronary artery disease (CAD). Decrease in myocardial contractility results as a response to a chronic hypoperfusion state that produces a change in cardiac myocyte metabolism, resulting in a perfusion-contraction mismatch in which function is sacrificed for survival. If revascularization is performed in a timely fashion, metabolism can be restored leading to recovery of function. Through the use of noninvasive imaging modalities, assessing myocardial viability can be easily performed and will aid in selecting those patients who will benefit from revascularization. Viable myocardium can be identified by nuclear modalities that have a high sensitivity but a lower specificity, such as thallium-201 single photon emission computed tomography and positron emission tomography (PET); or by the use of dobutamine stress echocardiogram (DSE), which has a decreased sensitivity but a better specificity. A modality that is increasingly being used with an overall good sensitivity and specificity is contrast-enhanced magnetic resonance imaging. The purpose of this review is to explore the amount of myocardial viability that is relevant to pursue revascularization, since as myocardial function improves there is a decrease in morbidity and mortality from heart failure and arrhythmias. [source] Electrical source imaging for presurgical focus localization in epilepsy patients with normal MRIEPILEPSIA, Issue 4 2010Verena Brodbeck Summary Purpose:, Patients with magnetic resonance (MR),negative focal epilepsy (MRN-E) have less favorable surgical outcomes (between 40% and 70%) compared to those in whom an MRI lesion guides the site of surgical intervention (60,90%). Patients with extratemporal MRN-E have the worst outcome (around 50% chance of seizure freedom). We studied whether electroencephalography (EEG) source imaging (ESI) of interictal epileptic activity can contribute to the identification of the epileptic focus in patients with normal MRI. Methods:, We carried out ESI in 10 operated patients with nonlesional MRI and a postsurgical follow-up of at least 1 year. Five of the 10 patients had extratemporal lobe epilepsy. Evaluation comprised surface and intracranial EEG monitoring of ictal and interictal events, structural MRI, [18F]fluorodeoxyglucose positron emission tomography (FDG-PET), ictal and interictal perfusion single photon emission computed tomography (SPECT) scans. Eight of the 10 patients also underwent intracranial monitoring. Results:, ESI correctly localized the epileptic focus within the resection margins in 8 of 10 patients, 9 of whom experienced favorable postsurgical outcomes. Discussion:, The results highlight the diagnostic value of ESI and encourage broadening its application to patients with MRN-E. If the surface EEG contains fairly localized spikes, ESI contributes to the presurgical decision process. [source] Palilalia, echolalia, and echopraxia,palipraxia as ictal manifestations in a patient with left frontal lobe epilepsyEPILEPSIA, Issue 6 2009Yang-Je Cho Summary Palilalia is a relatively rare pathologic speech behavior and has been reported in various neurologic and psychiatric disorders. We encountered a case of palilalia, echolalia, and echopraxia,palipraxia as ictal phenomena of left frontal lobe epilepsy. A 55-year-old, right-handed man was admitted because of frequent episodes of rapid reiteration of syllables. Video-electroencephalography monitoring revealed stereotypical episodes of palilalia accompanied by rhythmic head nodding and right-arm posturing with ictal discharges over the left frontocentral area. He also displayed echolalia or echopraxia,palipraxia, partially responding to an examiner's stimulus. Magnetic resonance imaging revealed encephalomalacia on the left superior frontal gyrus and ictal single photon emission computed tomography showed hyperperfusion just above the lesion, corresponding to the left supplementary motor area (SMA), and subcortical nuclei. This result suggests that the neuroanatomic substrate involved in the generation of these behaviors as ictal phenomena might exist in the SMA of the left frontal lobe. [source] Operative Results without Invasive Monitoring in Patients with Frontal Lobe Epileptogenic LesionsEPILEPSIA, Issue 10 2001A. Mariottini Summary: ,Purpose: To further explore the still controversial issues regarding whether all or most candidates for epilepsy surgery should be investigated preoperatively with invasive long-term video-EEG monitoring techniques (ILTVE). Methods: We studied five patients with intractable seizures since early childhood using the same protocol: clinical evaluation, magnetic resonance imaging (MRI) with fluid-attenuated inversion recovery (FLAIR) sequences, long-term video-EEG (LTVE) monitoring with scalp electroencephalogram (EEG), interictal single photon emission computed tomography (SPECT), positron emission tomography (PET), and neuropsychological testing. The patients' seizures had clinical features suggesting a frontal lobe (FL) origin. MRI scans revealed focal cortical dysplasia (CD) in four patients and a probable gliotic lesion in the fifth. The findings in both PET and SPECT images were congruent with those of the MRI. Scalp LTVE failed to localize the ictal onset, although the data exhibited features suggestive of both CDs and FL seizures. On the basis of these results, surgery was performed with intraoperative corticography, and the cortical area exhibiting the greatest degree of spiking was ablated. Results: Histopathologic study of four of the resected specimens confirmed the presence of CD, whereas in the fifth, there were features consistent with a remote encephaloclastic lesion. There were no postoperative deficits. Seizures in three of the patients were completely controlled at 2,3.5 years of follow-up; a fourth patient is still having a few seizures, which have required reinstitution of pharmacotherapy, and the fifth has obtained 70% control. All patients have had significant improvement in psychosocial measures. For comparison, five patients with generally similar clinical and neuroradiologic features to the previous group underwent preoperative ILTVE monitoring. The surgical outcomes between the two groups have not differed significantly. Conclusions: We conclude that patients with FL epilepsies may be able to undergo successful surgery without preoperative ILTVE monitoring, provided there is high concordance between neuroimaging tests (MRI, SPECT, PET) and the seizure phenotypes, even when routine EEGs and scalp LVTE fail to localize ictal onset unambiguously. The surgical outcomes of these patients generally paralleled those of the other subjects who also had FL epilepsy but who were operated on only after standard ILTVE monitoring. [source] Contralateral EEG Slowing and Amobarbital Distribution in Wada Test: An Intracarotid SPECT StudyEPILEPSIA, Issue 2 2000Seung Bong Hong Summary: Purpose: To relate the occurrence of contralateral electroencephalogram slowing (CES) to amobarbital distribution, we performed electroencephalogram (EEG) monitoring and intracarotid single photon emission computed tomography (SPECT) during an intracarotid amobarbital procedure (IAP). Methods: IAP was performed on 22 patients with temporal lobe epilepsy. CES was defined as the occurrence of significant EEG slowing on the contralateral hemisphere (>50% of the ipsilateral hemisphere slowing) after amobarbital injection. To map the distribution of the amobarbital, we injected a mixture of amobarbital and 99m technetium-ethylcysteinate dimer (99m Tc-ECD) into the internal carotid artery and performed a brain SPECT 2 h later. In the SPECT images, regions of interest were determined by ipsilateral and contralateral anterior cerebral artery territories (iACA, cACA), ipsilateral and contralateral middle cerebral artery territories (iMCA, cMCA), and ipsilateral and contralateral posterior cerebral artery territories (iPCA, cPCA), as well as ipsilateral and contralateral anterior and posterior mesial temporal regions (iAMT, cAMT, iPMT, cPMT). The perfusion of amobarbital was interpreted visually in each region. Results: Amobarbital was distributed in the iMCA in all the patients; in the iACA in 20 (90.9%) patients; in the iAMT in 14 (63.5%); and in the iPCA and iPMT in only two (9.1%). CES was observed in 13 (59.1%) patients. Cross-perfusion of amobarbital in limited areas of the cACA were observed in only four of 13 patients. Wada retention memory scores (WRMS) showed no significant difference between the CES- (n = 9) and CES+ (n = 13) groups. Conclusions: Amobarbital rarely perfused the iPCA territory and the iPMT region and was rarely delivered to the contralat-eral hemisphere. The occurrence of CES was not related to the cross-perfusion of amobarbital. CES appears to be produced by a transient functional disconnection from the ipsilateral hemisphere. [source] 99mTc-ethyl cysteinate dimer brain SPECT findings in early stage of dementia with Lewy bodies and Parkinson's disease patients: a correlation with neuropsychological testsEUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2008C.-C. Chang We examined clinical presentations, neuropsychological findings, and perfusion patterns of 99mTc-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) in patients with early stage dementia with Lewy bodies (DLB) (n = 17) and Parkinson's disease (PD) (n = 16), with age-matched healthy controls (n = 10). Seven paired regions of interest (ROIs) were drawn manually including inferior frontal, temporal, parietal, occipital, parieto-occipital junction, striatum and thalamus for semiquantitative measurement. Neuropsychological tests were applied for clinical correlation. The SPECT results showed significant hypoperfusion in DLB group in frontal, parietal, thalamus, temporal ROIs compared with controls (P < 0.01) whilst signals in temporal areas was significantly reduced compared with PD group (P < 0.05). Neuropsychological tests showed that DLB patients had deficits in mental manipulation, short-term memory, abstract thinking, drawing and semantic verbal fluencies (P < 0.05, compared with control). In addition, DLB group had lower scores than those with PD in mental manipulation, drawing and semantic verbal fluency (P < 0.05). Our study showed that even in early stages of DLB, neuropsychological and perfusion patterns were evident and may be different from PD group, despite they shared certain similarities both in neuropsychological and image findings compared with age-matched controls. [source] Cerebral blood flow in patients with diffuse axonal injury , examination of the easy Z -score imaging system utilityEUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2007T. Okamoto To evaluate the utility of easy Z -score imaging system (eZIS) in 27 diffuse axonal injury (DAI) cases. Twenty-seven DAI patients were examined with an magnetic resonance imaging (MRI) T2* sequence and with eZIS (seven women, 20 men; age range, 19,35 years; median age: 26.6 years). In this investigation, we excluded patients who exhibited complications such as acute subdural hematoma, acute epidural hematoma, intracerebral hematoma, or brain contusion. We examined the neuropsychological tests and correlated with findings from MRI/eZIS. Furthermore, we evaluated the degree of ventricular enlargement in the bifrontal cerebroventricular index (CVI). Patients were divided into two groups: the enlargement group (bifrontal CVI > 35%, 12 patients) and the non-enlargement group (bifrontal CVI < 35%, 15 patients). All of the patients showed cognitive deficits as observed from the neuropsycological test results. Fifteen out of 27 patients by MRI T1/T2 weighted images and fluid attenuated inversion recovery (FLAIR), 22 out of 27 patients by MRI T2* weighted images and 24 out of 27 patients by eZIS showed abnormal findings. In MRI T2* weighted imaging, the white matter from the frontal lobe, corpus callosum, and brainstem showed abnormal findings. With eZIS, 22 patients (81.5%) showed blood flow degradation in the frontal lobe, and 12 patients (44.4%) in cingulate gyrus. In the enlargement group, Functional Independence Measure, Mini-Mental State Examination, Verbal IQ (VIQ)/Full Scale IQ (FIQ), Trail Making Test-B (TMT-B), and Non-paired of Miyake Paired Test were significantly lower. Amongst 12 patients without ventricular enlargement who had no abnormal findings in MRI T1/T2 weighted images and FLAIR, abnormal findings were detectable in seven patients with MRI T2* weighted imaging and to 10 patients with eZIS. Results of the MRI examination alone cannot fully explain DAI frontal lobe dysfunction. However, addition of the eZIS-assisted analysis derived from the single photon emission computed tomography (SPECT) data enabled us to understand regions where blood flow was decreased, i.e., where neuronal functions conceivably might be reduced. [source] Molecular imaging in hereditary forms of parkinsonismEUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2007M. C. Shih The development of in vivo molecular imaging to evaluate the dopamine (DA) system with positron-emission tomography and single photon emission computed tomography has been of key importance on monitoring in vivo nigrostriatal neuronal loss in Parkinson's disease (PD), mostly through assessments of pre- and post-synaptic DA receptors. The discoveries of genes related to hereditary forms of parkinsonism (PARK1, PARK2, PARK6, PARK7 and PARK8) have increased our understanding either of distinct subtypes of clinical expression in PD or its etiology. This article revises current data on molecular neuroimaging of genetic forms of parkinsonism comparing and contrasting its main features with the classical sporadic forms. Awareness of the spectrum variance in the genotype and its respective PD phenotype are useful to distinguish different pathophysiological mechanisms of PD. [source] EFNS guideline on neuroimaging in acute stroke.EUROPEAN JOURNAL OF NEUROLOGY, Issue 12 2006Report of an EFNS task force Neuroimaging techniques are necessary for the evaluation of stroke, one of the leading causes of death and neurological impairment in developed countries. The multiplicity of techniques available has increased the complexity of decision making for physicians. We performed a comprehensive review of the literature in English for the period 1965,2005 and critically assessed the relevant publications. The members of the panel reviewed and corrected an initial draft, until a consensus was reached on recommendations stratified according to the European Federation of Neurological Societies (EFNS) criteria. Non-contrast computed tomography (CT) scan is the established imaging procedure for the initial evaluation of stroke patients. However, magnetic resonance imaging (MRI) has a higher sensitivity than CT for the demonstration of infarcted or ischemic areas and depicts well acute and chronic intracerebral hemorrhage. Perfusion and diffusion MRI together with MR angiography (MRA) are very helpful for the acute evaluation of patients with ischemic stroke. MRI and MRA are the recommended techniques for screening cerebral aneurysms and for the diagnosis of cerebral venous thrombosis and arterial dissection. For the non-invasive study of extracranial vessels, MRA is less portable and more expensive than ultrasonography but it has higher sensitivity and specificity for carotid stenosis. Transcranial Doppler is very useful for monitoring arterial reperfusion after thrombolysis, for the diagnosis of intracranial stenosis and of right-to-left shunts, and for monitoring vasospasm after subarachnoid hemorrhage. Currently, single photon emission computed tomography and positron emission tomography have a more limited role in the evaluation of the acute stroke patient. [source] A survey of neuroimaging research in European neurological departmentsEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2001K. Herholz In the international neurological literature, neuroimaging research plays an important role. Neuroimaging techniques are also of steadily increasing importance for clinical diagnosis and treatment monitoring. Therefore, neuroimaging research activities were surveyed by a questionnaire, which was completed by 100 neurological centres across Europe. It showed that most groups use magnetic resonance imaging (MRI), fMRI, computerized tomography (CT) and single photon emission computerized tomography (SPECT). Positron emission tomography (PET) and ultrasound are also employed by nearly half of the centres. Neuroimaging research involves co-operation amongst typically five to 10 disciplines. Cerebrovascular disease, dementia, cognitive disorders, epilepsy, movement disorders, brain tumours and multiple sclerosis are frequently being studied. Many groups rely on small budgets, have few full-time scientists and limited access to expensive resources. There is little exchange of scientists amongst laboratories. It was felt that funding and co-operation needed improvement in order to maintain a high standard in neuroimaging research. [source] Usefulness of 201TL SPECT/CT relative to 18F-FDG PET/CT in detecting recurrent skull base nasopharyngeal carcinomaHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 6 2009Ruoh-Fang Yen MD Abstract Background This study was designed to compare 201Tl single photon emission computed tomography (SPECT)/CT with 18-fluoro-2-deoxyglucose (18F-FDG) PET/CT in diagnosing recurrent skull base nasopharyngeal carcinoma (NPC). Methods Twenty-seven patients were recruited. Both 201Tl SPECT/CT and 18F-FDG PET/CT for each patient were performed at least 4 months later after initial therapy. Results The sensitivity and specificity for 201Tl SPECT/CT were 66.7% and 100%, and those for 18F-FDG PET/CT were 86.7% and 75.0%. Lesion/background ratios were obtained for the 10 lesions that were both SPECT and PET true positive. For the 8 patients with recurrences in nasopharyngeal regions, PET lesion/background ratios were all higher than SPECT lesion/background ratios. For the 2 patients with intracranial metastases, SPECT lesion/background ratios were higher than PET lesion/background ratios. Conclusion 201Tl SPECT/CT is as effective as 18F-FDG PET/CT in detecting recurrent NPC. For intracranial recurrence, 201Tl SPECT, because of its high intracranial lesion/background ratio, is probably better than 18F-FDG PET. © 2009 Wiley Periodicals, Inc. Head Neck, 2009 [source] Accuracy of technetium-99m SPECT-CT hybrid images in predicting the precise intraoperative anatomical location of parathyroid adenomasHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 4 2008Luke Harris MD Abstract Background. This study evaluated the accuracy of single photon emission computed tomography (SPECT)-CT imaging for the preoperative localization of parathyroid adenomas. Methods. This study included both a quantitative and qualitative accuracy measure. The quantitative measure was the distance between the location of the adenoma on the SPECT-CT scan and the location of the adenoma intraoperatively. Qualitatively, surgeons were asked whether or not the adenoma was in the exact location predicted by the SPECT-CT scan. The time from initial incision to identification of the parathyroid was recorded. Patients referred to London Health Sciences Centre for a suspected parathyroid adenoma were eligible for this study. Results. Twenty-three patients participated in this study. Eighteen (78.3%) had a single adenoma, 2 (8.7%) had double adenomas, and 3 (13.0%) had multiglandular hyperplasia. SPECT-CT correctly detected and localized 16 of 18 (88.9%) cases of single parathyroid adenomas. The mean distance between the location of the adenoma on the SPECT-CT scan and the location of the adenoma intraoperatively was 16.3 mm (95% , 19.0 mm). For single adenomas, the median time from skin incision to identification was 14 minutes (range, 8,40 minutes). The preoperative detection and localization of a single focus of sestamibi uptake yielded a parathyroid adenoma in the specified location in 80.0% of cases (95% CI, 97.4,66.5%). Conclusions. SPECT-CT predicted the intraoperative location of a single parathyroid adenoma within 19.0 mm with 95% confidence. The correct detection and localization of multiglandular disease remains difficult. © 2007 Wiley Periodicals, Inc. Head Neck, 2008 [source] Lymphoscintigraphy for sentinel node mapping using a hybrid single photon emission CT (SPECT)/CT system in oral cavity squamous cell carcinomaHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 10 2006Avi Khafif MD Abstract Background. We assessed the added clinical value of fused single photon emission computed tomography (SPECT) and low-dose CT images compared with planar images for sentinel node (SN) mapping in patients with oral cavity squamous cell carcinoma (SCC). Methods. Twenty consecutive patients with newly diagnosed biopsy-proven SCC of the oral cavity were enrolled. Scintigraphy was performed using a hybrid gamma-camera/low-dose CT system. Planar images and fused SPECT/CT images were interpreted separately. All patients underwent a sentinel node biopsy (SNB) followed by a neck dissection. All SNs underwent meticulous pathologic examination and immunohistochemistry staining (cytokeratin complex) in addition to routine pathologic examinations of the neck dissection specimen. Results. The sensitivity for the detection of nodal metastases was 87.5%. SPECT/CT improved SN identification and/or localization compared with planar images in 6 patients (30%). Conclusions. SPECT/CT SN mapping provides additional preoperative data of clinical relevance to SNB in patients with oral cavity SCC. © 2006 Wiley Periodicals, Inc. Head Neck, 2006 [source] A new automated delineation method for SPECT lung scans using adaptive dual-exponential thresholdingINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 1 2007Alex Wang Abstract An accurate method for delineating lung contours in single photon emission computed tomography (SPECT) is critical to respiratory studies such as pulmonary embolism (PE) and respiratory aerosol deposition. Current delineation methods are not adaptive in nature and may require a priori information on lung volumes. We have developed a dual-exponential thresholding method that solely requires SPECT scans, and is fast, accurate, and adaptive in nature. A dataset consisted of 90 patients was studied retrospectively. While most were suspected of PE, other pulmonary disorders were also present. SPECT ventilation scans were obtained after inhalation of ,40 MBq of 99mTc-Technegas. Examination of the corresponding natural logarithmically transformed histograms revealed dual exponential functions like pattern. Adaptive thresholds were found as the intercept between the two exponential functions. 350 Monte Carlo simulations representative of normally-ventilated scans with varying counts were used to quantitatively measure and evaluate the method. Our method correctly delineated lung volumes to above 97% agreement for 310 of the 350 Monte Carlo simulations with maximum count values greater than or equal to 31. The 40 low-count simulations were included purely as extreme cases. For real patient scenario, an experienced physician was called upon to visually delineate a sample of 50 actual patient scans, and these delineated lung volumes were used as gold standard and compared with those delineated using our method. Our results had an average of 96% agreement. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 22,27, 2007 [source] Usefulness of single photon emission computed tomography imaging in the detection of lumbar vertebral metastases from prostate cancerINTERNATIONAL JOURNAL OF UROLOGY, Issue 6 2008Tetsuo Nozaki Objective: To determine whether single photon emission computed tomography (SPECT) is useful in the detection of prostate cancer bone metastases in the lumbar vertebrae. Methods: Thirty-nine patients (12 with benign prostatic hyperplasia, 27 with prostate cancer) were considered and submitted to bone SPECT. All of them had increased uptake in lumbar vertebrae on bone scintigraphy. In those with prostate cancer, definitive diagnosis of bone metastases was established by magnetic resonance imaging (MRI). SPECT axial images were classified into five accumulation patterns: mosaic, large hot, diffuse, peripheral, and articular (or pediculate). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of bone SPECT were calculated. Results: Overall, 116 vertebral lesions (49 metastatic, 67 degenerative) were studied. Mosaic, large hot and diffuse patterns were more frequently associated with metastatic lesions (84.2%, 70.3%, and 63.1% of the cases, respectively). On the other hand, peripheral and articular (or pediculate) patterns were mostly ascribed to degenerative lesions (100% and 87.5% of the cases, respectively). Sensitivity, specificity, PPV and NPV of bone SPECT were 95.9% (47/49), 73.1% (49/67), 72.3% (47/65), and 96.1% (49/51), respectively. Conclusions: Bone SPECT provides better accuracy than bone scintigraphy in differential diagnosis of lumbar vertebral lesions from prostate cancer. [source] Iloprost inhalation redistributes pulmonary perfusion and decreases arterial oxygenation in healthy volunteersACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2009D. RIMEIKA Background: Previous studies have shown that ventilation,perfusion matching is improved in the prone as compared with that in the supine position. Regional differences in the regulation of vascular tone may explain this. We have recently demonstrated higher production of nitric oxide in dorsal compared with ventral human lung tissue. The purpose of the present study was to investigate regional differences in actions by another vasoactive mediator, namely prostacyclin. The effects on gas exchange and regional pulmonary perfusion in different body positions were investigated at increased prostacyclin levels by inhalation of a synthetic prostacyclin analogue and decreased prostacyclin levels by unselective cyclooxygenase (COX) inhibition. Methods: In 19 volunteers, regional pulmonary perfusion in the prone and supine position was assessed by single photon emission computed tomography using 99mTc macro-aggregated albumin before and after inhalation of iloprost, a stable prostacyclin analogue, or an intravenous infusion of a non-selective COX inhibitor, diclofenac. In addition, gas distribution was assessed in seven subjects using 99mTc-labelled ultra-fine carbon particles before and after iloprost inhalation in the supine position. Results: Iloprost inhalation decreased arterial PaO2 in both prone (from 14.2±0.5 to 11.7±1.7 kPa, P<0.01) and supine (from 13.7±1.4 to 10.9±2.1 kPa, P<0.01) positions. Iloprost inhalation redistributed lung perfusion from non-dependent to dependent lung regions in both prone and supine positions, while ventilation in the supine position was distributed in the opposite direction. No significant effects of non-selective COX inhibition were found in this study. Conclusions: Iloprost inhalation decreases arterial oxygenation and results in a more gravity-dependent pulmonary perfusion in both supine and prone positions in healthy humans. [source] Value of regional cerebral blood flow in the evaluation of chronic liver disease and subclinical hepatic encephalopathyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 10 2003YUSUF YAZGAN Abstract Aims:, Regional changes in cerebral blood flow in patients with chronic hepatitis, cirrhosis and subclinical hepatic encephalopathy were investigated in the present study using single photon emission computed tomography (SPECT). Methods:, Twenty patients with cirrhosis, 11 patients with chronic hepatitis, and nine healthy controls were included in the study. Cerebral SPECT were obtained for all patients. The percentages of cerebral blood flow of 14 regions to the cerebellar blood flow were determined. Only the patients with cirrhosis underwent psychometric evaluation: visual evoked potentials (VEP) measurements and electroencephalogram (EEG) recordings along with blood levels of albumin, bilirubin, and ammonia were measured and prothrombin time was determined in cirrhotic patients. These patients were classified according to the Child,Pugh classification. Results:, Among cirrhotic patients, six had abnormal results in VEP studies, 11 in psychometric tests and with six in EEG evaluation. Any abnormality in psychometric tests and/or VEP studies is taken as the main criterion; subclinical hepatic encephalopathy was detected in 12 of 20 patients. According to SPECT results in patients with subclinical encephalopathy, a statistically significant decrease in cerebral blood flow in right thalamus and nearly significant decrease in left thalamus were observed. Regional blood flow was significantly higher in the frontal lobes of patients with cirrhosis when compared with healthy controls. Similarly, cerebral blood flow in frontal and cingulate regions was significantly higher in patients with chronic hepatitis than in healthy controls. There was no relationship between cerebral blood flow and blood levels of ammonia or Child,Pugh score, in cirrhotic patients. Conclusion:, Significant changes in cerebral blood flow may be present in chronic liver diseases and the authors suggest that the measurement of changes in cerebral blood flow might be useful in detecting subclinical hepatic encephalopathy. [source] Identification of Hemodynamically Significant Restenosis after Percutaneous Transluminal Coronary Angioplasty in Acute Myocardial Infarction by Transesophageal Dobutamine Stress Echocardiography and Comparison with Myocardial Single Photon Emission Computed TomographyJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2001STEPHAN ROSENKRANZ M.D. Background: Beside thrombolysis, percutaneous transluminal coronary angioplasty (PTCA) has become a well-established treatment for acute myocardial infarction. However, restenosis occurs in approximately 15%-40 % of patients. Despite a frequently occurring infarct-related regional systolic dysfunction at rest, the identification of hemodynamically relevant restenosis seems important in terms of risk stratification, adequate treatment, and possible improvement of prognosis in these patients. This study was designed to assess the role of transesophageal dobutamine stress echocardiography and myocardial scintigraphy for identification of hemodynamically significant restenosis after PTCA for acute myocardial infarction. Methods: Multiplane transesophageal stress echocardiography (dobutamine 5, 10, 20, 30, and 40 ,g/kg per min) studies and myocardial single photon emission computed tomography (SPECT) studies were performed in 40 patients, all of whom underwent PTCA in the setting of acute myocardial infarction , 4 months prior to the test. Repeated coronary angiography was performed in all study patients who showed stress-induced perfusion defects or wall-motion abnormalities, or both. Results: Significant restenosis (, 50%) was angiographically found in 15 (37.5%) of 40 patients. Of these 15 patients, transesophageal dobutamine stress echocardiography identified restenosis in 12 (80%) and myocardial SPECT in 14 (93%), yielding diagnostic agreement in 70% of patients. Echocardiographic detection of restenosis was based mainly on a biphasic response to increasing doses of dobutamine. Sensitivity and specificity for identification of hemodynamically relevant restenosis in individual patients was 80% and 92%, respectively for dobutamine stress echocardiography versus 93% and 68% for myocardial SPECT. Conclusions: Both transesophageal dobutamine stress echocardiography and myocardial SPECT were highly sensitive in identifying significant restenosis after PTCA for acute myocardial infarction. Therefore, either test, as a single diagnostic tool or especially if performed together, are clinically valuable alternatives to coronary angiography for the detection of restenosis after PTCA for acute myocardial infarction. [source] Preparation of a technetium-99m SPECT agent for imaging the sigma-2 receptor status of solid tumorsJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 13 2001Robert H. Mach Abstract The synthesis and in vitro binding of a novel 99mTc-labeled radiotracer for imaging the sigma-2 (,2) receptor status of breast tumors is described. Structural characterization and in vitro binding studies were conducted using the corresponding rhenium surrogate, Re-2. X-ray crystallographic studies revealed that the complexation reaction gave exclusively the syn isomer. In vitro binding studies indicated that this complex has a high affinity for ,2 (Ki=13.7 nM) versus ,1 receptors (Ki=1125 nM). These data indicate that [99mTc]2 may be a promising agent for imaging the ,2 receptor status of tumors in vivo with the functional imaging technique, single photon emission computed tomography (SPECT). Copyright © 2001 John Wiley & Sons, Ltd. [source] The efficacy of cylindrical titanium mesh cage for the reconstruction of a critical-size canine segmental femoral diaphyseal defectJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 7 2006Ronald W. Lindsey Abstract The authors developed a novel technique for the reconstruction of large segmental long bone defects using a cylindrical titanium mesh cage (CTMC). Although the initial clinical reports have been favorable, the CTMC technique has yet to be validated in a clinically relevant large animal model, which is the purpose of this study. Under general anesthesia, a unilateral, 3-cm mid-diaphyseal segmental defect was created in the femur of an adult canine. The defect reconstruction technique consisted of a CTMC that was packed and surrounded with a standard volume of morselized canine cancellous allograft and canine demineralized bone matrix. The limb was stabilized with a reamed titanium intramedullary nail. Animals were distributed into four experimental groups: in Groups A, B, and C (six dogs each), defects were CTMC reconstructed, and the animals euthanized at 6, 12, and 18 weeks, respectively; in Group D (three dogs), the same defect reconstruction was performed but without a CTMC, and the animals were euthanized at 18 weeks. The femurs were harvested and analyzed by gross inspection, plain radiography, computed tomography (CT), and single photon emission computed tomography (SPECT). The femurs were mechanically tested in axial torsion to failure; two randomly selected defect femurs from each group were analyzed histologically. Groups A, B, and C specimens gross inspection, plain radiography, and CT, demonstrated bony restoration of the defect, and SPECT confirmed sustained biological activity throughout the CTMC. Compared to the contralateral femur, the 6-, 12-, and 18-week mean defect torsional stiffness was 44.4, 45.7, and 72.5%, respectively; the mean torsional strength was 51.0, 73.6, and 83.4%, respectively. Histology documented new bone formation spanning the defect. Conversely, Group D specimens (without CTMC) demonstrated no meaningful bone formation, biologic activity, or mechanical integrity at 18 weeks. The CTMC technique facilitated healing of a canine femur segmental defect model, while the same technique without a cage did not. The CTMC technique may be a viable alternative for the treatment of segmental long bone defects. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1438,1453, 2006 [source] Measurement of porto-systemic shunting in mice by novel three-dimensional micro-single photon emission computed tomography imaging enabling longitudinal follow-upLIVER INTERNATIONAL, Issue 8 2010Christophe Van Steenkiste Abstract Background and aims: The reference method for diagnosing porto-systemic shunting (PSS) in experimental portal hypertension involves measuring 51Chrome (51Cr)-labelled microspheres. Unfortunately, this technique necessitates the sacrifice of animals. Alternatively, 99mtechnetium-macroaggregated albumin (99mTc-MAA) has been used; however, planar scintigraphy imaging techniques are not quantitatively accurate and adequate spatial information is not attained. Here, we describe a reliable, minimally invasive and rapid in vivo imaging technique, using three-dimensional single photon emission computed tomography (3D SPECT) modus, that allows more accurate quantification, serial measurements and spatial discrimination. Methodology: Partial portal vein ligation, common bile duct ligation and sham were induced in male mice. A mixture of 51Cr microspheres and 99mTc-macroaggregated albumin particles was injected into the splenic pulpa. All mice were scanned in vivo with ,SPECT (1 mm spatial resolution) and, when mandatory for localisation, a ,SPECT-CT was acquired. A relative quantitative analysis was performed based on the 3D reconstructed datasets. Additionally, 51Cr was measured in the same animals to calculate the correlation coefficient between the 99mTc detection and the gold standard 51Cr. In each measuring modality, the PSS fraction was calculated using the formula: [(lung counts)/(lung counts+liver counts)] × 100. Results: A significant correlation between the 99mTc detection and 51Cr was demonstrated in partial portal vein ligation, common bile duct ligation and sham mice and there was a good agreement between the two modalities. ,SPECT scanning delivers high spatial resolution and 3D image reconstructions. Conclusion: We have demonstrated that quantitative high-resolution ,SPECT imaging with 99mTc-MAA is useful for detecting the extent of PSS in a non-sacrificing set-up. This technology permits serial measurements and high-throughput screening to detect baseline PSS, which is especially important in pharmacological studies. [source] Differentiating vascular parkinsonism from idiopathic Parkinson's disease: A systematic review,,MOVEMENT DISORDERS, Issue 2 2010Seema Kalra MRCP Abstract Vascular parkinsonism (VP) remains a loose constellation of various clinical features. We systematically reviewed studies comparing clinical, neuroimaging and other investigations that might distinguish VP from idiopathic Parkinson's disease (PD). Medline, Embase, Cinahl (R), and PsycINFO were searched by querying appropriate key words. Reports were included if the study population contained comparative findings between patients with VP and PD. Twenty-five articles fulfilled the selection criteria. Patients with VP were older, with a shorter duration of illness, presented with symmetrical gait difficulties, were less responsive to levodopa, and were more prone to postural instability, falls, and dementia. Pyramidal signs, pseudobulbar palsy, and incontinence were more common in VP. Tremor was not a main feature of VP. Structural neuroimaging was more likely to be abnormal in VP (90,100% of cases) than in PD (12,43% of cases), but there was no specific abnormal structural imaging pattern for VP. Two studies of presynaptic striatal dopamine transporters (using single photon emission computed tomography) showed a significant reduction in striatal uptake ratios in PD but not in VP, whereas another study found that only the mean asymmetry index was significantly lower in VP. Various other investigations, including alternative imaging techniques, electrophysiological, and neuropsychological studies, are reported, but the diverse diagnostic criteria used makes it difficult to reach any firm conclusions. The development of accepted international diagnostic criteria for VP is urgently needed to facilitate further studies. © 2010 Movement Disorder Society [source] Dopamine transporter single photon emission computerized tomography in the diagnosis of dementia with Lewy bodies,MOVEMENT DISORDERS, Issue S2 2009FRCP, Rodney W.H. Walker PhD Abstract Dementia with Lewy bodies (DLB) is part of the spectrum of Lewy body disorders. However, it may be difficult to diagnose patients who have dementia but no Parkinsonism. Visual and semiquantitative assessment of the nigrostriatal dopaminergic nerve terminals in the putamen and caudate nuclei can be obtained with single photon emission computerized tomography (SPECT) using ligands that bind to the dopamine transporter molecule in the membranes of the nigrostriatal nerve terminals. This can be employed as a means of identifying subclinical degeneration of nigrostriatal neurones in patients with suspected DLB, increasing the probability of the diagnosis. In several studies, the sensitivity and specificity of abnormal dopamine transporter scans with regard to diagnosing probable DLB are better than 75 and 90%, respectively. This communication outlines the evidence for this and discusses some of the advantages, potential disadvantages, and areas of uncertainty with regard to the use of dopamine transporter SPECT in DLB diagnosis. © 2009 Movement Disorder Society [source] Amnestic mild cognitive impairment in Parkinson's disease: A brain perfusion SPECT study,,MOVEMENT DISORDERS, Issue 3 2009Flavio Nobili MD Abstract The purpose of this study was to investigate cortical dysfunction in Parkinson's disease (PD) patients with amnestic deficit (PD-MCI). Perfusion single photon emission computed tomography was performed in 15 PD-MCI patients and compared (statistical parametric mapping [SPM2]) with three groups, i.e., healthy subjects (CTR), cognitively intact PD patients (PD), and common amnestic MCI patients (aMCI). Age, depression, and UPDRS-III scores were considered as confounding variables. PD-MCI group (P < 0.05, false discovery rate,corrected for multiple comparisons) showed relative hypoperfusion in bilateral posterior parietal lobe and in right occipital lobe in comparison to CTR. As compared to aMCI, MCI-PD demonstrated hypoperfusion in bilateral posterior parietal and occipital areas, mainly right cuneus and angular gyrus, and left precuneus and middle occipital gyrus. With a less conservative threshold (uncorrected P < 0.01), MCI-PD showed hypoperfusion in a left parietal region, mainly including precuneus and inferior parietal lobule, and in a right temporal-parietal-occipital region, including middle occipital and superior temporal gyri, and cuneus-precuneus, as compared to PD. aMCI versus PD-MCI showed hypoperfusion in bilateral medial temporal lobe, anterior cingulate, and left orbitofrontal cortex. PD-MCI patients with amnestic deficit showed cortical dysfunction in bilateral posterior parietal and occipital lobes, a pattern that can be especially recognized versus both controls and common aMCI patients, and to a lesser extent versus cognitively intact PD. The relevance of this pattern in predicting dementia should be evaluated in longitudinal studies. © 2008 Movement Disorder Society [source] [123I] FP-CIT spect study in vascular parkinsonism and Parkinson's diseaseMOVEMENT DISORDERS, Issue 9 2007Jan Zijlmans MD Abstract There is substantial evidence to support a role for small vessel disease (SVD) as a cause for vascular parkinsonism (VP). Using [123I] FP-CIT SPECT (single photon emission computed tomography), we have tried to determine whether VP patients have pre-synaptic dopaminergic function similar to PD patients, and whether the severity of parkinsonian symptoms as well as the levodopa response in VP patients are correlated with pre-synaptic dopaminergic dysfunction. Thirteen patients fulfilling operational clinical criteria for VP had [123I] FP-CIT scans. Mean [123I] FP-CIT uptake in the basal ganglia was significantly lower in VP patients than in healthy controls, and the asymmetry index was not significantly different between these groups. In contrast, compared with the PD group, only the mean asymmetry index was significantly lower in VP patients. None of the parameters measured was significantly different between VP patients who had an insidious onset of parkinsonism (VPi) and those who had an acute onset (VPa). There was a significant correlation between the bilateral basal ganglia FP-CIT uptake reduction in the VP patients and UPDRS motor scores, but not with the mean % reduction in motor UPDRS after levodopa. We suggest that in the majority of VP patients, pre-synaptic dopaminergic function is reduced. The presence of a rather symmetrical FP-CIT uptake in the basal ganglia may help to distinguish VP from PD and could therefore be used as a criterion for the clinical diagnosis of VP. © 2007 Movement Disorder Society [source] | |||||||||||||||||||||||||||||||||||||