Efficacy Assessment of Endovascular Stenting in Patients with Unilateral Middle Cerebral Artery Stenosis Using Statistical Probabilistic Anatomical Mapping Analysis of Basal/Acetazolamide Brain Perfusion SPECT / 핵의학분자영상

PURPOSE: The aim of this study was to evaluate the hemodynamic changes after endovascular stenting in patients with unilateral middle cerebral artery (MCA) stenosis using statistical probabilistic anatomical mapping (SPAM) analysis of basal/acetazolamide (ACZ) Tc-99m ECD brain perfusion SPECT. MATERIALS AND METHODS: Eight patients (3 men and 5 women, 64.8+/-10.5 years) who underwent endovascular stenting for unilateral MCA stenosis were enrolled. Basal/ACZ Tc-99m ECD brain perfusion SPECT studies were performed by one-day protocol before and after stenting. Using SPAM analysis, we compared basal cerebral perfusion (BCP) counts and cerebrovascular reserve (CVR) index of the MCA territory before stenting with those after stenting. RESULTS: After stenting, no patient had any complication nor additional stroke. In SPAM analysis, 7 out of the 8 patients had improved BCP counts of the MCA territory and 7 out of the 8 patients had improved CVR index of the MCA territory after stenting. Before stenting, the mean BCP counts and CVR index in the affected MCA territory were 47.1+/-2.2 ml/min/100 g and -2.1+/-2.9%, respectively. After stenting, the mean BCP counts and CVR index in the affected MCA territory were improved significantly (48.3+/-2.9 ml/min/100 g, p=0.025 and 0.1+/-1.3%, p=0.036). CONCLUSION: This study revealed that SPAM analysis of basal/ACZ brain perfusion SPECT would be helpful to evaluate hemodynamic efficacy of endovascular stenting in unilateral MCA stenosis.

Assessment of Cerebrovascular Reserve before and after STA-MCA Bypass Surgery by SPECT and SPM Analysis

OBJECTIVE: The purpose of this study was to objectively assess the efficacy of superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery using Technetium (Tc)-99m-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) in patients who underwent STA-MCA bypass surgery. MATERIALS AND METHODS: Brain perfusion SPECT images obtained at baseline and after the administration of acetazolamide were reconstructed using statistical parametric mapping in 23 patients, both before and after STA-MCA bypass surgery. The clinical outcomes of the surgery were also recorded and compared with the hemodynamic changes. A voxel with an uncorrected p-value of less than 0.001 was considered to be statistically significant. RESULTS: SPECT images of the territory supplied by the bypass graft showed an increase in both cerebrovascular flow and reserve at baseline, and the increase was significantly higher following the administration of acetazolamide. All patients showed improvement of clinical symptoms and increased blood flow to the left temporal, parietal, and frontal cortices as well as the thalamus. CONCLUSION: Brain SPECT effectively and objectively demonstrated the improved outcomes of STA-MCA bypass surgery, and thus may be used in postoperative analyses.

An Artifact Caused by Using the Inadequate Acquisition Parameter in Tc-99m ECD Brain Perfusion SPECT / 대한핵의학회잡지

Although artifacts in tomographic imaging can arise from a number of sources, this case presents an artifact caused by using inadequate acquisition parameters which do not match the collimator with which a camera equipped in Tc-99m ECD brain SPECT. Whenever the collimator in tomographic studies is changed, we should take care to use suitable parameters of acquisition protocol according to the collimator with which a camera is fitted. Other ways to prevent an error of this type is to use a point source.

The Clinical Usefulness of Tc-99m ECD Brain SPECT in Acute Measles Encephalitis / 대한핵의학회잡지

PURPOSE: Since the prognosis of measles encephalitis is poor, early diagnosis and proper management are very important to improve clinical outcomes. We compared Tc-99m ECD brain SPECT (SPECT) with MR imaging (MRI) for the detection of acute measles encephalitis. MATERIALS AND METHODS: Eleven patients (M: F=4: 7, age range 18 months-14 yrs) with acute measles encephalitis were enrolled in this studies. All of them underwent both MRI and SPECT. The results of SPECT were scored from 0 (normal) to 3 (most severe defect) according to perfusion state. We compared two image modalities for the detection of brain abnormality in acute measles encephalitis. RESULTS: Seven of 11 patients (63.6%) revealed high signal intensity in the white matter on T2WI of MRI, on the other hand all patients (100%) showed hypoperfusion on SPECT. Severe perfusion deficits above score 2 were located with decreasing frequencies in the frontal lobe (81.8%), temporal lobe (72.7%), occipital lobe (27.3%), basal ganglia (27.3%), and parietal lobe (9.1%). CONCLUSION: We conclude that SPECT is more useful than MRI for the detection of brain involvement in patients with acute measles encephalitis.

Tc-99m-ECD SPECT Brain Imaging in Children with Tourette's Syndrome

We undertook this study to assess the patterns of regional cerebral perfusion (RCP) with SPECT using Technetium-99m-ethyl cysteinate dimer (Tc-99m-ECD) in children with Tourette's Syndrome (TS), and to compare these with the patterns in a group of normal controls. The study sample consisted of 38 children (7 to 14 years) who met the ICD-10 and DSM/IV criteria for Tourette's Syndrome, and a control group of 18 children (9 to 14 years). The Children's Depression Inventory and Maudsley Obsessional-Compulsive Questionnaire were used for assessment, and the severity of motor and vocal tics were assessed using the Goetz Rating Scale. The RCP values were significantly lower in the TS group in left caudate, cingulum, right cerebellum, left dorsolateral prefrontal, and the left orbital frontal region. A positive correlation was found between the severity of vocal tics and blood flow of mid-cerebellum, right dorsolateral prefrontal and left dorsolateral prefrontal regions. Although no depressive or obsessive patients were included in the study, the depression and obsession scores were found to be negatively correlated with all RCP values, especially in the temporal regions. Further studies are needed to explore the relationship between the hypoperfusion of certain brain areas and the underlying neurophysiology and neurobiology of patients with TS. Additional disturbances such as obsessive- compulsive symptoms and depressive symptoms should also be assessed.

Cortical Dysplasia: Tc-99m ECD SPECT Findings and Comparative Study with MRI according to Pathologic Grading / 대한핵의학회잡지

PURPOSE: Cortical dysplasia (CD) designates a diverse group of malformations resulting from one or more abnormalities in the development of the cerebral cortex. We investigated the findings of interictal SPECT and the diagnostic usefulness of interical and ictal SPECT according to pathological grading (PG) in comparison with MRI. MATERIALS AND METHODS: This study included 16 patients (M:F=9:7, age: 19.9+/-11.8 yrs) with pathologically proven CD. Tc-99m ECD SPECT was performed in all patients: interictal 11, interictal and ictal 3, ictal 2. MRI were obtained in all patients and image analysis was done blindly as to the result of SPECT. Pathologic findings of CD were classified into grade 1 (G1, dyslamination), grade 2 (G2, dysplastic neurons) and grade 3 (G3, balloon cells). We compared SPECT with MRI in lesions-to-lesions and analyzed the result according to PG. RESULTS: In SPECT and MRI, 38 and 27 lesions were visually recognized. In 14 interictal SPECT, variable findings in 35 lesions were demonstrated: 26 were hypoperfusion, 7 hyperperfusion, 2 heterotopic perfusion in the white matter. By comparison between two studies, missed lesions were founded: SPECT were 1 lesion, MRI 12. Review of missed 12 lesions of MRI were followed according to PG; G1 patients were 16.7% (4/19), G2 40.0% (6/15), and G3 50% (2/4). CONCLUSION: Interictal SPECT in CD showed variable findings such as hypoperfusion, hyperperfusion or heterotopic perfusion. However, for detection of missed CD on MRI, SPECT may help to detect a functional abnormality of the lesion with high PG.

Tc-99m ECD Brain SPECT in Patients with Traumatic Brain Injury : Evaluating Distribution of Hypoperfusion and Assesment of Cognitive and Behavioral Impairment in Relation to Thalamic Hypoperfusion / 대한핵의학회잡지

PURPOSE: We evaluated the distribution of hypoperfusion in patients with traumatic brain injury (TBI) and the relationship of thalamic hypoperfusion to severity of cognitive and behavioral sequelae. MATERIALS AND METHODS: Tc-99m ECD SPECT and MRI were performed in 103 patients (M/F=81/22, mean age 34.7+/-15.4 yrs) from 0.5 to 55 months (mean 10.3 months) after TBI. The patients were divided into three groups showing no abnormalities (G1), focal (G2) and diffuse injury (G3) on MRI. Psychometric tests assessed 11 cognitive or behavioral items. In all patients, we evaluated the distribution of hypoperfused areas in SPECT, and in 57/103 patients, neuropsychological (NP) abnormalities in patients with thalamic hypoperfusion were compared with those of patients without thalamic hypoperfusion. RESULTS: The perfusion deficits were most frequently located in the frontal lobe (G1, 42.3%: G2 34.5%: G3 33.3%), temporal lobe (24~26%) thalami (21~22.4%), parietal and occipital lobe (< or =10%). Numbers of NP abnormalities in the cases of cortical hypoperfusion with or without concomitant thalamic hypoperfusion were following: the former 4.7+/-1.5 and the latter 3.2+/-1.4 in G1, 5.0+/-1.1 and 4.8+/-1.2 in G2, 6.8+/-1.8 and 6.3+/-1.1 in G3, respectively. This difference according to thalamic hypoperfusion was significant in G1 (p=0.002), but was not significant in G2 or G3. CONCLUSION: SPECT in patients with TBI had demonstrated hypoperfusion mostly involving the frontal, temporal and thalami. In normal group on MRI, frontal hypoperfusion was more prominent than that of any other group, Furthermore in this group, SPECT could predict severity of NP outcome by concomitant thalamic hypoperfusion with cerebral cortical abnormalities.

Effect of Acupuncture on Regional Cerebral Blood Flow at Acupoints GV 20 , GV. 26 , LI. 4 , ST. 36 , SP. 6 Evaluated by Tc-99m ECD Brain SPECT / 대한핵의학회잡지

PURPOSE: To evaluate the effect of acupuncture on regional cerebral blood flow (rCBF) at acupoints suggested by oriental medicine to be related to the treatment of cerebrovascular diseases. MATERIALS AND METHODS: Rest/acupuncture-stimulation Tc-99m ECD brain SPECT using a same-dose subtraction method was performed on 54 normal volunteers (34 males, 20 females, age range from 18 to 62 years) using six paradigms: acupuncture at acupoints GV. 20, GV. 26, LI. 4, ST. 36 and SP. 6. In the control study, needle location was chosen on a non-meridian focus 1 cm posterior to the right fibular head. All images were spatially normalized, and the differences between rest and acupuncture stimulation were statistically analyzed using SPM for Windows . RESULTS: Acupuncture applied at acupoint GV. 20 increased rCBF in both the anterior frontal lobes, the right frontotemporal lobes, and the left anterior temporal lobe and the left cerebellar hemisphere. Acupuncture at GV. 26 increased rCBF in the left prefrontal cortex. Acupuncture at LI. 4 increased rCBF in the left prefrontal and both the inferior frontal lobes, and the left anterior temporal lobe and the left cerebellar hemisphere. Acupuncture at ST. 36 increased rCBF in the left anterior temporal lobe, the right inferior frontal lobes, and the left cerebellum. Acupuncture at SP. 6 increased rCBF in the left inferior frontal and anterior temporal lobes. In the control stimulation, no significant rCBF increase was observed. CONCLUSION: The results demonstrated a correlation between stimulation at each acupoint with increase in rCBF to the corresponding brain areas.

Reversible Cerebral Hypoperfusion in Cyclosporine Neurotoxicity: A Case Report / 대한핵의학회잡지

We experienced a case of cerebral hypoperfusion due to cyclosporine neurotoxocity confirmed only by Tc-99m ECD brain SPECT. A 53-year-old female had received allogenic peripheral blood stem cell transplantation due to refractory plasmacytoid lymphoma. Cyclosporine and steroid had been administrated to prevent graft versus host disease. Twenty days after transplantation, she became delirious and suffered from generalized tonic-clonic seizure. Immediately, brain MRI and MR angiography were performed and these studies did not show any abnormal findings. However, Tc-99m ECD brain SPECT showed diffuse hypoperfusion in the left cerebral hemisphere and blood cyclosporine level was 962.6 ng/ml. Cyclosporine administration was stopped and discontinuation of cyclosporine resulted in disappearance of all neurological symptoms. The same neurological symptoms recurred with cyclosporine re-administration for management of exacerbated graft versus host disease. In this case, Tc-99m ECD brain SPECT proved very helpful in the diagnosis of cycloporine neurotoxicity.

Usefulness of ICTAL (99m)TC-ECD Brain SPECT for Pre-Surgical Evaluation in Temporal Lobe Epilepsy / 대한간질학회지

PURPOSE: We evaluated usefulness of ictal (99m)Tc-ECD SPECT in temporal lobe epilepsy (TLE) patients for per-surfical evaluation and also correlated ictal SPECT patterns with the semiology of seizures. We also investifated whether there are any differences in ictal SPECT pattern between temporal lobe seizures with or without secondary generalized tonic-clonic seizure (GTC). METHODS: ictal SPECT was performed in 26 TLE patients who had unlateral hippocampal atrophy (20 patients), other focal remporal lesions (4 patients), and normal MRI finding (2 patients). All patients underwent temporal lobectomy with a minimim 27 months follow-up with excellent post-surgical seizure outcome (Engel's classification class I). During CCTV monitoring (99m)Tc-ECD was injected during ictal peroid in all patients with a mean delay of 37.5+/-13.3 sec after seizure onset (mean seizure duration : 99.3+/-38.0 sec). Ictal SPECT was visually analysed by two blinded observers. RESULTS: Ictal (99m)Tc-ECD SPECT showed unilateral temporal hyperperfusion concordant with epileptogenic foci in 25/26 (96.2%). The hyperperfusion of the ipsilateral basal ganglia was evident in 12/19 (63.2%) during contralateral (or predominantly contralateral) hand dystonic/ tonic posture. The contralateral cerebellar hyperperfusion was observed in the 6/26 (23.1%). Seizures with secondary GTC at the time of injection showed brainstem and bilateral thalamic hyperperfusion in 6/8 (75.0%) and seizures without secondary GTC at the time of injection showed brainstem and bilateral thalamic hyperperfusion in 2/18 (11.1%). There was significant difference between two groups (p<0.01). CONCLUSION: L Ictal (99m)Tc-ECD SPECT is a useful method to localize the epileptic foci for pre-surfical evaluation and the hyperperfusion of bilateral thalamus and brainstem is significantly frequent during secondary generalization of temporal lobe seizure.

Improved Cerevral Blood Flow and Cerebrovascular Reserve after Carotid Endarterectomy in Patients with Carotid Stenosis and Contralateral Carotid Occlusion: Acetazolamide Stress Brain SPECT Study / 대한핵의학회잡지

PURPOSE:Carotid endarterectomy may benefit patients with bilateral carotid stenosis by improving cerebrovascular hemodynamics of ipsilateral as well as contralateral cerebral hemispheres. We investigated cerebrovascular hemodynamics after carotid endarterectomy in patients with contralateral carotid occlusion by acetazolamide stress brain SPECT. MATERIALS AND METHODS: Subjects were 14 symptomatic patients (all men, mean age 66 yrs) with carotid stenosis (> 50%) with contralateral carotid occlusion. Acetazolamide stress Tc-99m ECD brain SPECTs were performed within 2 weeks before and after carotid endarterectomy using one day protocol. Cerebral blood flow (CBF) and cerebrovascular reserve (CVR) were assessed visually. In 12 patients, correlation between the patency of proximal anterior cerebral or anterior communicating arteries (A1/A-comm) and the improvement of CBF or CVR after endarterectomy was assessed. RESULTS: Preoperative SPECT showed reduced CBF in 2 ipsilateral and 10 contralateral hemispheres. CVR was reduced in 4 ipsilateral and 9 contralateral hemispheres. Of 12 hemispheres with reduced CBF, 2 hemispheres (16.7%) showed improvement of CBF after endarterectomy. However, reduced CVR was improved in all 4 ipsilateral and 7 of 9 (78%) of contralateral hemispheres after endarterectomy. Three of 4 with stenotic A1/A-comm and 4 of 8 with patent A1/A-comm had reduced contralateral CVR. Reduced contralateral CVR improved in all 3 patients with stenotic A1/A-comm and 3 of 4 with patent A1/A-comm. CONCLUSION: Acetazolamide stress brain SPECT demonstrated improvement of compromised cerebrovascular reserve in not only ipsilateral but also contralateral hemispheres of patients with contralateral carotid occlusion after carotid endarterectomy, and may, therefore, be useful for evaluating cerebral blood flow and cerebrovascular reserve after carotid endarterectomy.