99mTc-ethyl Cysteinate Dimer Research Articles

Establishing Diagnostic Reference Levels for Single-Photon Emission Computed Tomography (SPECT) Imaging: A Preliminary Study in Indian Healthcare Settings.

Introduction In nuclear medicine, there is a critical need to balance the control and optimization of radiation doses to ensure patient safety while achieving high-quality diagnostic outcomes. However, diagnostic reference levels (DRLs) for nuclear medicine imaging studies have not been established in India. This study aims to fill this gap by establishing institutional DRLs and assessing radiation dose data specifically for Nuclear Medicine SPECT examinations. Methods This research was a cross-sectional observational study conducted in a single tertiary care setting, involving 1,250 patients. Data on the administered activity for 18 common single photon emission computed tomography (SPECT) procedures were gathered from 2019 to 2021. The 75th percentile (Q3) was established as the baseline for the institutional DRLs. Furthermore, the study conducted comparative analyses with established international DRLs. Results The study proposed institutional DRLs based on 18 SPECT nuclear medicine imaging examinations. The highest Q3 DRLs were identified for 99mTc-sestamibi (1193 MBq), followed by 99mTc-methylene diphosphonate (747 MBq) and 99mTc-ethyl cysteinate dimer (608 MBq). The lowest DRL was recorded for 99mTc gastric emptying imaging (37 MBq). Comparisons with international DRLs indicated close alignment with European Association of Nuclear Medicine Medical Internal Radiation Dose guidelines, while DRLs set by the National Council on Radiation Protection and Measurements (NCRP) were identified as distinct in several key aspects when compared to other established DRLs. Conclusion This research marks a significant step toward standardizing SPECT procedure doses in India, contributing to improved patient safety and care in nuclear medicine. The established DRLs will enhance the optimization of administered activities, ensure adherence to international standards, and improve diagnostic quality while reducing radiation exposure. These institutional DRLs will serve as the foundation for developing a roadmap to establish national DRLs.

Brain perfusion imaging using 99mTc-Ethyl cysteinate dimer with acetazolamide challenge reveals “steal phenomenon” in suspected stroke: A case report

Chronic cerebral ischaemia (CCI) is a potentially life-threatening condition caused by carotid artery occlusion, hypotension and other causes. Moyamoya Syndrome (MMS) is an example of CCI, in which there is progressive narrowing of the branches of the internal carotid artery. Conventionally, magnetic resonance angiography (MRA) or digital subtraction angiogram (DSA) are utilised to visualise the vascular abnormalities. However, nuclear medicine imaging can help to give more functional information that can improve the management and surgical outcome of patients. There is a need to highlight the role of single-photon emission computed tomography/computed tomography (SPECT/CT) imaging using 99mTc-Ethyl Cysteinate Dimer (99mTc-ECD) with Acetazolamide (ACZ) challenge to diagnose MMS and decide on further surgical or medical intervention. We illustrate a case of a young woman who benefited from this imaging for the management of her condition.

A Pilot Study on Cerebral Blood Flow and Mini-Mental State Examination to Predict Amyloid Deposition in Preclinical Alzheimer's Disease.

Earlier differential diagnosis of dementia remains a major challenge. Although amyloid deposition by positron emission tomography is an emerging standard for the diagnosis of Alzheimer's disease, it is too expensive for routine use in clinical settings. We conducted a pilot study on the potential usefulness of single-photon emission computed tomography and the Mini-Mental State Examination to predict amyloid positron emission tomography positivity in preclinical Alzheimer's disease. Eighteen subjects, including 11 with mild cognitive impairment and 7 with subjective cognitive decline, underwent 18F-florbetapir positron emission tomography, 99mTc-ethylcysteinate dimer cerebral perfusion single-photon emission computed tomography, and the Mini-Mental State Examination. For the assessment of amyloid deposition, visual judgment as a qualitative method and a semiautomatic software analysis as a quantitative method were used. Six subjects were judged as amyloid positive, including 4 mild cognitive impairment and 2 subjective cognitive decline subjects. Compared to the amyloid positron emission tomography-negative group, this group showed a statistically significant difference in the Mini-Mental State Examination recall score [2 (1 : 3) vs. 3 (2 : 3), P = .041] and single-photon emission computed tomography findings from the amyloid-negative group. In the mild cognitive impairment subgroup, correlations were found between amyloid deposition and single-photon emission computed tomography indicators, while in the subjective cognitive decline subgroup, only the Mini-Mental State Examination recall score correlated with amyloid deposition. The Mini-Mental State Examination recall score and single-photon emission computed tomography indicators may be worthwhile for further evaluation as predictors of amyloid deposition in the preclinical stage.

A Headrest Made of Extruded Polystyrene Reduces the Influence of Attenuation Correction on Human Brain SPECT Images.

Previous reports suggest that a headrest made of carbon significantly influences cerebral blood flow in the anterior and posterior regions by image reconstruction and attenuation correction (AC). The present study aimed to develop a headrest that reduces the influence of the AC process on human brain SPECT. Methods: To validate the performance of a headrest made of extruded polystyrene (XPS), 10 healthy controls and 43 patients with cerebrovascular disease underwent 99mTc-ethyl cysteinate dimer SPECT using a carbon headrest and an XPS headrest. We evaluated the anterior-to-posterior and middle-to-posterior ratio of the brain regions in filtered backprojection (FBP) Chang AC, ordered-subset expectation maximization (OSEM) Chang AC, and OSEM CT-based AC. Results: The anterior-to-posterior ratio was significantly higher with the carbon headrest than with the XPS headrest in FBP Chang AC and OSEM Chang AC (P < 0.001). There was no significant difference between the materials in OSEM CT-based AC. The middle-to-posterior ratio did not differ to a statistically significant extent in any correction process. Conclusion: Acquisition of brain SPECT images with an XPS headrest and processing by the FBP or OSEM Chang AC method enables the influence of the headrest to be reduced, especially in anterior and posterior brain regions.

Prediction of the development of delirium after transcatheter aortic valve implantation using preoperative brain perfusion SPECT.

Delirium is an important prognostic factor in postoperative patients undergoing cardiovascular surgery and intervention, including transcatheter aortic valve implantation (TAVI). However, delirium after transcatheter aortic valve implantation (DAT) is difficult to predict and its pathophysiology is still unclear. We aimed to investigate whether preoperative cerebral blood flow (CBF) is associated with DAT and, if so, whether CBF measurement is useful for predicting DAT. We evaluated CBF in 50 consecutive patients before TAVI (84.7±4.5 yrs., 36 females) using 99mTc ethyl cysteinate dimer single-photon emission computed tomography. Preoperative CBF of the DAT group (N = 12) was compared with that of the non-DAT group (N = 38) using whole brain voxel-wise analysis with SPM12 and region of interest-based analysis with the easy-Z score imaging system. Multivariable logistic regression analysis with the presence of DAT was used to create its prediction model. The whole brain analysis showed that preoperative CBF in the insula was lower in the DAT than in the non-DAT group (P<0.05, family-wise error correction). Decrease extent ratio in the insula of the DAT group (17.6±11.5%) was also greater relative to that of the non-DAT group (7.0±11.3%) in the region of interest-based analysis (P = 0.007). A model that included preoperative CBF in the insula and conventional indicators (frailty index, short physical performance battery and mini-mental state examination) showed the best predictive power for DAT (AUC 0.882). These results suggest that preoperative CBF in the insula is associated with DAT and may be useful for its prediction.

Persistent brain damage in reversible cerebral vasoconstriction syndrome on 99mTc-ethyl cysteinate dimer single-photon emission computed tomography: A long-term observational study

BackgroundBlood-brain barrier (BBB) breakdown is considered a key step in the pathophysiology of reversible cerebral vasoconstriction syndrome (RCVS); however, its temporal course remains unclear. Based on the characteristics and dynamics of 99mTc-ethyl cysteinate dimer (99mTc-ECD) as a tracer, 99mTc-ECD single-photon emission computed tomography (SPECT) can detect not only hypoperfusion but also BBB breakdown and/or brain tissue damage. Therefore, this study aimed to investigate this course using 99mTc-ECD SPECT. MethodsBetween 2011 and 2019, we enrolled seven patients (one male and six female patients) with RCVS without ischemic or hemorrhagic stroke or posterior reversible encephalopathy syndrome. 99mTc-ECD SPECT was performed repeatedly in each patient. SPECT data were statistically analyzed using an easy Z-score imaging system. ResultsThunderclap headache was the initial symptom in all the patients and was most commonly triggered by bathing (three patients). All the patients exhibited vasoconstriction and reduced cerebral uptake of 99mTc-ECD during the acute stage. Follow-up assessment from 3 to 16 months showed that reduced cerebral uptake persisted in all the patients, even after the vasoconstriction had resolved. ConclusionReduced cerebral uptake of 99mTc-ECD persisted in the late stage of RCVS, even after vasoconstriction and headache subsided. BBB breakdown and/or brain tissue damage may underlie this phenomenon. 99mTc-ECD SPECT is an effective neuroimaging method to detect brain functional abnormalities, reflecting BBB breakdown or tissue damages, throughout the treatment course of RCVS.

A Comparative Study of Regional Cerebral Blood Flow Asymmetry Index in Stroke Patients with or without Poststroke Depression Using 99m Tc-ECD Single-Photon Emission Computed Tomography.

Introduction Stroke is a major cause of death and disability around the globe. The development of depression following a stroke further increases the disability and impairs functional recovery. In recent decades, despite the advancement in structural and nuclear medicine imaging, the pathophysiologic basis of poststroke depression (PSD) is not well understood. Etiopathogenesis of PSD is multifactorial and afflictions of the frontal lobe, hippocampus, limbic region, and basal ganglia projections are implicated. Aim The aim of this study was to assess the regional cerebral blood flow (rCBF) using 99m Tc-ethyl cysteinate dimer single-photon emission computed tomography (SPECT) in patients with (PSD + ) or without PSD (PSD–). Materials and Methods To evaluate the hemispheric asymmetry, the percentage of asymmetry index (AI) was calculated for frontal, temporal, parietal, occipital, putamen, caudate, and thalamic regions of brain and compared between PSD+ and PSD–. The correlation between AIs over the different brain regions was also established in patients of PSD+ and PSD–. Our study cohort included 122 patients between 6 weeks and 1 year of stroke. Depression was present in 52 (42.6%) patients, assessed by hospital anxiety and depression scale (HADS) and general health questionnaire-28 items (GHQ-28) scale. The 28 patients with PSD+ and 18 PSD– gave consent for SPECT study. Results Our results are based on 46 patients who underwent SPECT study. In patients with PSD+ and PSD–, the HADS and GHQ-28 scores were 8.93 ± 2.77 vs. 3.94 ± 2.15 ( p = 0.001) and 40.96 ± 9.48 vs. 17.72 ± 5.38 ( p = 0.001), respectively. A significant difference in rCBF AI was found in the temporal lobe ( p = 0.03) between patients of PSD+ and PSD–. On logistic regression analysis, the odds ratio of rCBF AI for temporal lobe was 0.89 (95% confidence interval [CI]: 0.80–0.99; p = 0.04) and caudate nucleus was 0.85 (95% CI: 0.73–0.98; p = 0.03), which were statistically significant. PSD correlated with AI in temporal region ( r = –0.03; p = 0.03) but did not show significant correlation with other regions of brain between PSD+ and PSD–. Conclusion The presence of temporal lobe rCBF AI on SPECT is significantly associated with PSD. This may reflect the dysfunction of the limbic system and contribute to the occurrence of PSD.

The Role of Ictal Brain Single Photon-Emission Tomography in Refractory Epilepsy Complementary to Magnetic Resonance Imaging and Electroencephalogram – Our Experience

Background: Correct identification of the epileptogenic zone (EZ) is essential for surgical success for focal epilepsy. There are multiple modalities which are available for detecting the anatomical and the functional abnormalities. The purpose of this study was to determine the complementary role of ictal brain single photon-emission tomography (SPECT) in delineating the EZ in addition to electroencephalogram (EEG) and magnetic resonance imaging (MRI). Methodology: Clinical and diagnostic data from patients with refractory epilepsy undergoing ictal brain SPECT (IEBS), EEG, MRI between 2014 and 2019 were analyzed retrospectively. Tc99m-ethyl cysteinate dimer was administered intravenously during or within 30 s of onset of seizure activity. Results: Eighty-nine patients aged: Four months-32 years (median age: Eight years) were studied. The concordance of IEBS with MRI and EEG were studied. Among them, EEG was normal in 22 and abnormal in 67 (multifocal: 40, unifocal: 8, generalized: 19). MRI was normal in 36, abnormal in 26, nonspecific in 24 and not done in three patients. Of the 80 patients showing tracer uptake in IEBS, 14-multifocal uptake and 66-unifocal uptake (EEG and MRI were not showing any abnormality in 15 and 27 patients, respectively). Unifocal uptake in IEBS was concordant with EEG in 11 (16.67%) and MRI in 15 (27.72%). The concordance and nonconcordance of the results among the two imaging modalities or EEG assuming surgical site as the gold standard was noted. Twenty-two had undergone surgical removal of the EZ, 15 was conformable with MRI or IEBS. Conclusion: In patients with noncontributory EEG and MRI, IEBS could detect the epileptogenic focus. Therefore, depending entirely on EEG and MRI may limit its diagnosis. IEBS, MRI and EEG are complementary to each other in the detecting the epileptogenic focus.

A Novel method of seizure onset zone localization by serial Tc-99m ECD brain perfusion SPECT clearance patterns.

In this prospective study, we postulate that there is a difference between clearance of [99mTc]Tc- ethyl cysteinate dimer (ECD) in the seizure onset zone (SOZ) and other brain areas and thus SOZ localization by clearance patterns might become a potential novel method for SOZ localization in epilepsy. The parametric images of brain ECD clearance were generated by linear regression model analysis from serial brain SPECT scans from 30 to 240min after ECD injection (7-times point) in 7 patients with drug-resistant epilepsy and 3 normal volunteers. Clearance patterns of the SOZ confirmed by good surgical outcome or consensus with other investigations were analyzed quantitatively and semi-quantitatively by visual grading (slower or faster washout than contralateral brain regions). The average [99mTc]Tc-ECD clearance rates of SOZs were + 1.08% ± 2.57%/hr (wash in), -7.02% ± 2.56%/hr (washout), and -5.37% ± 1.71%/hr (washout) in ictal, aura and interictal states, respectively. Paired t-tests between the SOZ and contralateral regions showed statistically significant difference (p = 0.039 in interictal state). Clearance patterns that can define the SOZs were 1) wash in and slow washout on ictal slope, 2) fast washout on aura slope and interictal slope with 100% (6/6), 100% (2/2) and 75% (6/8) localization using ictal, aura, and interictal slope maps, respectively. Our study provided the evidence that clearance pattern methods are potential additive diagnostic tools for SOZ localization when routine one-time point SPECT are unable to define the SOZ.

Comparison of early F-18 Florbetaben PET/CT to Tc-99m ECD SPECT using voxel, regional, and network analysis

This study aimed to validate early-phase F-18 Florbetaben positron emission tomography (eFBB PET) as a brain perfusion test and determine the optimal reference region. A total of 27 patients with early Parkinson’s disease with Tc-99m ethyl cysteinate dimer single photon emission tomography (ECD SPECT) and FBB PET were included. Six reference regions, including whole brain (GN), pons, central white matter (CWM), whole cerebellum (WC), WC with brain stem (WC + B), and cerebellar grey matter (CG), were applied to obtain SUVR using cortex volume-of-interest (VOI). Reference regions of WC (r 0.886), WC + B (r 0.897), and CG (r 0.904) had highest correlation values of cortex-VOI SUVR between both perfusion images (all p < 0.001). Early-phase FBB PET had a significant linear correlation of CG-normalized SUVR of the cortex, basal ganglia, thalamus, and midbrain with ECD SPECT in voxel-wise analysis (FDR adjusted-p < 0.05). Early-phase FBB PET extracts more ICNS than ECD SPECT, as 9 ICNS and 4 ICNs, respectively. Both eFBB PET and ECD SPECT well discriminated PD from DLB (Area-under-curve of receiver-operating-characteristics, 0.911 for eFBB PET, 0.922 for ECD SPECT). Our findings suggest that eFBB PET is a reliable perfusion test based on a high correlation with ECD SPECT using cerebellum-based normalization methods.

Cerebral Microbleeds, Cerebrospinal Fluid, and Neuroimaging Markers in Clinical Subtypes of Alzheimer's Disease

Lobar cerebral microbleeds (CMBs) in Alzheimer's disease (AD) are associated with cerebral amyloid angiopathy (CAA) due to vascular amyloid beta (Aβ) deposits. However, the relationship between lobar CMBs and clinical subtypes of AD remains unknown. Here, we enrolled patients with early- and late-onset amnestic dominant AD, logopenic variant of primary progressive aphasia (lvPPA) and posterior cortical atrophy (PCA) who were compatible with the AD criteria. We then examined the levels of cerebrospinal fluid (CSF) biomarkers [Aβ1-42, Aβ1-40, Aβ1-38, phosphorylated tau 181 (P-Tau), total tau (T-Tau), neurofilament light chain (NFL), and chitinase 3-like 1 protein (YKL-40)], analyzed the number and localization of CMBs, and measured the cerebral blood flow (CBF) volume by 99mTc-ethyl cysteinate dimer single photon emission computerized tomography (99mTc ECD-SPECT), as well as the mean cortical standard uptake value ratio by 11C-labeled Pittsburgh Compound B-positron emission tomography (11C PiB-PET). Lobar CMBs in lvPPA were distributed in the temporal, frontal, and parietal lobes with the left side predominance, while the CBF volume in lvPPA significantly decreased in the left temporal area, where the number of lobar CMBs and the CBF volumes showed a significant inversely correlation. The CSF levels of NFL in lvPPA were significantly higher compared to the other AD subtypes and non-demented subjects. The numbers of lobar CMBs significantly increased the CSF levels of NFL in the total AD patients, additionally, among AD subtypes, the CSF levels of NFL in lvPPA predominantly were higher by increasing number of lobar CMBs. On the other hand, the CSF levels of Aβ1-38, Aβ1-40, Aβ1-42, P-Tau, and T-Tau were lower by increasing number of lobar CMBs in the total AD patients. These findings may suggest that aberrant brain hypoperfusion in lvPPA was derived from the brain atrophy due to neurodegeneration, and possibly may involve the aberrant microcirculation causing by lobar CMBs and cerebrovascular injuries, with the left side dominance, consequently leading to a clinical phenotype of logopenic variant.

Comparison of Cerebral Blood Flow Patterns in Patients with Phantom Bite Syndrome with Their Corresponding Clinical Features.

BackgroundPhantom bite syndrome (PBS) is characterized by an uncomfortable sensation during occlusion without any evident abnormality. A recent case–control study with single-photon emission computed tomography (SPECT) using 99mTc-ethyl cysteinate dimer could not find the specific features of regional cerebral blood flow (rCBF), which might be due to the heterogeneity of PBS. We analyzed the brain images of PBS corresponding to the clinical features by studying PBS subgroups.MethodsThis study contributes to elucidating the pathophysiology of PBS by evaluating regional brain perfusion on SPECT and its clinical features. We performed SPECT using 99mTc-ethyl cysteinate dimer in 44 patients with PBS. The SPECT images were analyzed qualitatively and quantitatively.ResultsAsymmetrical rCBF patterns were detected, corresponding to symptom laterality. Patients with PBS with right-side symptoms showed right-side-predominant rCBF asymmetry in the parietal region and left-side-predominant rCBF asymmetry in the thalamus, and vice versa. Moreover, the analysis of the association between rCBF and patient behaviors revealed that patients who blamed their dentists for their symptoms tended to have a symmetrical rCBF pattern.ConclusionPatients with PBS showed blood flow imbalance in the thalamus and parietal region corresponding to symptom laterality. There are two types of symmetrical and asymmetrical rCBF patterns in the pathophysiology of PBS despite similar clinical manifestations.

The Role of the Cerebellum in Pain Perception: A Brain SPECT Perfusion Study in Patients with Burn Injuries.

Virtual reality (VR) is a promising tool for distraction analgesia. This study aims to compare brain perfusion patterns while patients were undergoing burn wound care in two conditions-VR distraction and control (NoVR). With IRB approval, four patients hospitalized for acute burn care (three males and one female) participated in the study. All patients underwent wound care on two consecutive days; 1 day with standard analgesia and adjunctive VR, and the other day with standard analgesia alone, otherwise the wound care was very similar. Tc-99m ethyl cysteinate dimer was injected during wound care at the time of peak pain. Subjective patient reports on a 0-10 scale of pain intensity, time spent thinking about pain, and "fun" as well as opioid equivalent usage were analyzed. Voxel by voxel subtraction analysis of brain perfusion Single Photon Emission Computed Tomography (SPECT) images was performed at the group level. Statistical significance threshold was defined as P<.05. Mean group subjective scores (VR, NoVR, statistical significance, and P-value) were observed for maximal pain intensity (9.0, 8.8, insignificant, and P = .809), time spent thinking about pain (5.2, 10.0, significant, and P = .015), and fun (6.0, 2.5, significant, and P = .012). Subtraction group analysis demonstrated VR-induced modulation of brain activity with statistically significant relative suppression of cerebellar activation in the VR compared to intense cerebellar activation in the NoVR environments. Relative decrease in cerebellar perfusion based on stringent statistical threshold in the VR environment combined with improved subjective pain experience supports the hypotheses on the role of cerebellum in perception of noxious stimuli.

Ictal SPECT in Psychogenic Nonepileptic and Epileptic Seizures.

Psychogenic nonepileptic seizures (PNES) are a common and debilitating problem in patients with epilepsy. They can be virtually indistinguishable from epileptic seizures, demanding video-electroencaphalogram monitoring, which is costly and not widely available, for differential diagnosis. Specific functional brain correlates of PNES have not been demonstrated so far. We hypothesized that PNES and epileptic seizures have distinct brain activation patterns, assessed by functional neuroimaging during ictal events of both conditions. Compare ictal brain activation patterns of PNES and epileptic seizures using single-photon emission computerized tomography. We prospectively assessed brain functional activation using single-photon emission computerized tomography 99mTc-ethyl cysteinate dimer in 26 patients with PNES, confirmed by trained psychiatrists in epileptology, who had their seizures induced by provocative tests compared with 22 age- and sex-matched subjects with temporal lobe epilepsy who underwent prolonged intensive video-electroencaphalogram monitoring. In PNES patients compared with temporal lobe epilepsy group, we found a consistent increase in regional cerebral blood flow in the right precuneus (Brodmann area 7; P=0.003) and right posterior cingulate cortex (Brodmann area 31; P=0.001), as well as a decrease in regional cerebral blood flow in the right amygdala (P=0.027). Activation of default mode network brain areas and temporoparietal junction may be a distinct feature of ictal PNES and could be explained by a disruption between movement prediction input and sensory outcome. Such information mismatch might be the neurobiological underpinning of dissociative episodes.

Evaluation of Balloon Test Occlusion Before Therapeutic Carotid Artery Occlusion: Flat Detector Computed Tomography Cerebral Blood Volume Imaging versus Single-Photon Emission Computed Tomography

We aimed to compare flat detector computed tomography cerebral blood volume (FD-CBV) imaging to single-photon emission computed tomography (SPECT) as an adjunctive technique during balloon test occlusion (BTO) in patients with intracranial aneurysms or tumors. Twelve patients who underwent SPECT (99mTc-ethyl cysteinate dimer) and FD-CBV imaging during BTO were enrolled. Color-coded cerebral blood flow (CBF) images and color-coded FD-CBV images were generated and visually inspected whether there were asymmetries between the ipsilateral and contralateral cerebral hemispheres. Region of interest measurements were performed on the color-coded images at the same locations for both modalities. The mean interhemispheric region of interest ratios were calculated, and the ratio between these were estimated using linear regression models. Ten patients had no symptoms during BTO. Two patients developed subtle but inconclusive neurologic changes approximately 10 minutes after balloon inflation; their images showed asymmetric color-coded images with decreased CBF and FD-CBV in the ipsilateral hemisphere. The mean interhemispheric ratio of CBF was significantly smaller in patients with subtle changes than in those without (0.84 vs. 0.98; P < 0.001). Similarly, the mean interhemispheric ratio of FD-CBV was significantly smaller in patients with subtle changes than in those without (0.88 vs. 1.06; P= 0.01). No patient showed increased CBF or FD-CBV in the ipsilateral hemisphere. The patients with decreased CBF on SPECT also showed decreased FD-CBV in the ipsilateral hemisphere. FD-CBV imaging may be useful as an adjunctive technique for BTO before potential therapeutic carotid artery occlusion.

In Differential Diagnosis of Dementia Application of Easy Z-score Imaging System in Single Photon Emission Computed Tomography Brain Perfusion Scan

Application of easy Z score imaging system (eZIS) on brain perfusion SPECT images for quantitative evaluation of rCBF has attempted to explore the differential diagnosis of dementia with various degenerative diseases and to evaluate discrimination of early Alzheimer’s disease (AD) from other types of dementia. This retrospective study was done with various degenerative diseases that underwent brain perfusion SPECT using 99mTc ethyl cysteinate dimer were included. Brain perfusion SPECT was performed in 58 patients (M/F = 48/10) with mean age of 61.2±10.4 years (41-90). Decreased rCBF was observed in the area suspected early AD in 20 cases (34%) and in the frontal gyrus and insula in 10 cases (17%). And decreased rCBF was observed in occipital lobe and, precuneus, gyrus and posterior cingulate cortex in 8 cases (14%). Discrete areas of decreased rCBF were seen in 14 cases (24%) and the rest of 6 cases (11%) showed normal rCBF. Clinically suspected AD patients were divided into two groups on basis of MMSE score (group A, mild stage of AD, MMSE =20-26 and group B, moderate to severe stage of AD, MMSE=10-19). Mean MMSE and mean Z scores were 22.9±1.11 and 1.01±0.35 in group A (n = 12) while 17.56±0.96 and 2.62±0.59 in group B (n= 8). There was negative correlation between MMSE and eZIS score; r = - 0.69 in group A (p = 0.002); r = - 0.58 in group B (p = 0.019) and r = - 0.93 overall (p = 0.000). Quantification of rCBF with eZIS score was well associated with clinical MMSE scoring in this study group with clinical likelihood of having AD. In rest of the cases, SPECT findings and surface view analysis by eZIS, the affected area of decreased rCBF were consistent with clinically suspected different types of degenerative disease manifesting dementia.

A change of cerebral perfusion of patients with chronic neuropsychological impairments before and after a daytreatment group rehabilitation

The objective of this study is to evaluate a change of cerebral perfusion of patients with chronic neuropsychological impairments (NPIs) before and after a daytreatment group rehabilitation, using 99mTc-ethylcysteinate dimer single photon emission computed tomography (Tc-ECD SPECT) and its novel analytic software. Eight patients were examined in the chronic period of acquired brain injury with NPIs. All patients received a daytreatment group rehabilitation (3 hours once per week for half a year). The group rehabilitation included patient and family education, mindfulness exercise and group discussion exercise. The examinations of patients were performed before and after the group rehabilitation, and it included the assessment of neurological deficit, cognitive functions, and Tc-ECD SPECT. Statistical parametric mapping (SPM) was applied to each Tc-ECD SPECT image, for spatial pre-processing and analysis and to determine the quantitative perfusion change before and after the group intervention (paired t -test, uncorrected, P < 0.001). SPM analysis of Tc-ECD SPECT showed the significant improvement of cerebral perfusion in right frontal lobe (Brodmann area 10) before and after the group rehabilitation. There was no significant improvement in cognitive functions as assessed with structured batteries for NPIs, while there was a trend towards the improvement behaviorally (for example, 6 patients had been able to rework after the intervention). Using Tc-ECD SPECT and its novel analytic software, we identified specific lesions with improvement of cerebral perfusion before and after the daytreatment group rehabilitation for NPIs. It might relate with social reintegration of patient with NPIs.

Effects of white matter lesions on brain perfusion in patients with mild cognitive impairment

ObjectiveTo evaluate the effects of white matter lesions on regional cerebral blood flow in subjects with amnestic mild cognitive impairment. Patients and MethodsSeventy-five subjects with mild cognitive impairment (36 men and 39 women; mean age, 78.1 years) were included in the study. We used the Mini-Mental State Examination to assess cognitive function. All subjects underwent brain magnetic resonance imaging and 99mTc ethylcysteinate dimer single photon emission computed tomography. Subjects were stratified based on the presence or absence of white matter lesions on magnetic resonance imaging. Statistical parametric mapping of differences in regional cerebral blood flow between the two groups were assessed by voxel-by-voxel group analysis using SPM8. ResultsOf all 75 subjects with mild cognitive impairment, 46 (61.3%) had mild to moderate white matter lesions. The prevalence of hypertension tended to be higher in subjects with white matter lesions than in those without white matter lesions. Mini-Mental State Examination scores were significantly lower in subjects with white matter lesions than in those without white matter lesions. Subjects with white matter lesions had decreased regional cerebral blood flow mainly in the frontal, parietal, and medial temporal lobes, as well as the putamen, compared to those without white matter lesions. ConclusionIn subjects with mild cognitive impairment, white matter lesions were associated with cognitive impairment and mainly frontal lobe brain function.

Imaging & neuropsychological changes in brain with spiritual practice: A pilot study.

Background & objectives:Some studies have systematically assessed the effects of spiritual practice (SP) on the brain using combined neuropsychological testing and functional imaging. The objective of the present study was to compare imaging and neuropsychological changes in healthy individuals after SP and those with only physical exercise.Methods:Healthy adult male volunteers, aged 25-45 yr were randomized into two groups. Group 1 (SP group) underwent the SP and group 2 (controls) did brisk walk for 30 min daily. Detailed neuropsychological evaluation, resting-state functional magnetic resonance imaging (fMRI) and brain 99mTc ethyl cysteinate dimer single-photon emission computed tomography (SPECT) were carried out for both groups before and three months after intervention.Results:Post-intervention, resting state fMRI showed increased connections of left precuneus (in the posterior cingulate cortex area of default mode network) in group 1 and increased left frontal connections in group 2. The neuropsychological tests showed significant improvement in ‘Speed of Processing’ (Digit Symbol Test) in group 1 and in Focused Attention (Trail Making A) in group 2. The SPECT data in group 1 showed significant improvement in perfusion of the frontal areas, with relatively lesser improvement in parietal areas. Group 2 showed significant improvement in perfusion predominantly in parietal areas, as compared to frontal areas. In addition, significantly improved mood was reported by group 1 and not by group 2.Interpretation & conclusions:This pilot study shows important functional imaging and neuropsychological changes in the brain with SP.

Role of Neuroimaging on Differentiation of Parkinson’s Disease and Its Related Diseases

An accurate diagnosis of Parkinson's disease (PD) is a prerequisite for therapeutic management. In spite of recent advances in the diagnosis of parkinsonian disorders, PD is misdiagnosed in between 6 and 25% of patients, even in specialized movement disorder centers. Although the gold standard for the diagnosis of PD is a neuropathological assessment, neuroimaging has been playing an important role in the differential diagnosis of PD and is used for clinical diagnostic criteria. In clinical practice, differential diagnoses of PD include atypical parkinsonian syndromes such as dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration, caused by a striatal dopamine deficiency following nigrostrial degeneration. PD may also be mimicked by syndromes not associated with a striatal dopamine deficiency such as essential tremor, drug-induced parkinsonism, and vascular parkinsonism. Moreover, difficulties are associated with the clinical differentiation of patients with parkinsonism from those with Alzheimer's disease. In this review, we summarize the typical imaging findings of PD and its related diseases described above using morphological imaging modalities (conventional MR imaging and neuromelanin MR imaging) and functional imaging modalities (99mTc-ethyl cysteinate dimer perfusion single photon emission computed tomography, 123I-metaiodobenzylguanidine myocardial scintigraphy, and 123I-FP-CIT dopamine transporter single photon emission computed tomography) that are clinically available in most hospitals. We also attempt to provide a diagnostic approach for the differential diagnosis of PD and its related diseases in clinical practice.